Inflammation Research

Introduction Fenofibrate is an agonist of peroxisome proliferator activated receptor alpha (PPAR-α), that possesses anti-inflammatory, antioxidant, and anti-thrombotic properties. Fenofibrate is effective against a variety of viral infections and different inflammatory disorders. Therefore, the aim of critical review was to overview the potential role of fenofibrate in the pathogenesis of SARS-CoV-2 and related complications. Results By destabilizing SARS-CoV-2 spike protein and preventing it from binding angiotensin-converting enzyme 2 (ACE2), a receptor for SARS-CoV-2 entry, fenofibrate can reduce SARS-CoV-2 entry in human cells Fenofibrate also suppresses inflammatory signaling pathways, which decreases SARS-CoV-2 infection-related inflammatory alterations. In conclusion, fenofibrate anti-inflammatory, antioxidant, and antithrombotic capabilities may help to minimize the inflammatory and thrombotic consequences associated with SARSCoV-2 infection. Through attenuating the interaction between SARS-CoV-2 and ACE2, fenofibrate can directly reduce the risk of SARS-CoV-2 infection. Conclusions As a result, fenofibrate could be a potential treatment approach for COVID-19 control.

Background Pulmonary fibrosis (PF) is a chronic, progressive interstitial lung disease with unknown etiology, associated with increasing morbidity and pessimistic prognosis. Pulmonary fibroblasts (PFbs) are the key effector cells of PF, in which abnormal activation and proliferation is an important pathogenesis of PF. Ring finger protein 2 (RNF2), is identified as the catalytic subunit of poly-comb repressive complex 1, which is closely related to occurrence and development of lung cancer, but its function in PF has not been revealed. In this paper, we sought to identify the regulatory role of RNF2 in lung fibrogenesis and its underlying mechanisms. Methods The expression of RNF2 in lung fibrosis tissue (human and Bleomycin-induced mouse) and cell model (TGF-β1-induced HFL1 cells) was examined by immunoblotting analysis and immunofluorescence. Western blot, qRT-PCR were performed to evaluate the expression of pro-fibrogenic cytokines (including α-SMA, ECM and MMPs/ TIMPs) induced by TGF-β1 in HFL1 cells. Cell proliferation, cycle progression and apoptosis were examined by fow cytometric. Molecular interactions were tested by Co-IP assays. Results RNF2 expression was elevated in PF tissues compared to normal adjacent tissues and in PFbs (HFL1) induced by TGF-β1. Furthermore, knockdown of RNF2 could evidently inhibit the abnormal expression of pro-fibrogenic cytokines (including α-SMA, ECM and MMPs/TIMPs) induced by TGF-β1 in HFL1 cells. Functionally, RNF2 silencing could significantly suppress TGF-β1-induced anomalous proliferation, cell cycle progression, apoptosis and autophagy in HFL1 cells. Mechanistically, RNF2 deficiency could effectively inhibit the abnormal activation of mTOR signaling pathway in TGF-β1-induced HFL1 cells, and mTOR pathway had feedback regulation on the expression of RNF2. Further studies RNF2 could regulate the phosphorylation level of RB1 through interacting with p16 to destroy the binding of p16 and CDK4 competitively. Simultaneously, overexpression of RNF2 could show the opposite results. Conclusions These results indicated that RNF2 is a potent pro-fibrogenic molecule for PFbs activation and proliferation through mTOR and p16-CDK4-Rb signaling pathways, and RNF2 inhibition will be a potential therapeutic avenue for treating PF.

Background and objectives miRNAs play a crucial role in regulating immune responses. However, the effect of miR-124-3p on type 2 inflammation in allergic rhinitis (AR) is unclear. We aimed to study the immune regulation of miR-124-3p in AR and the mechanisms involved. Methods The direct interaction between miR-124-3p and IL-4Rα was confirmed through a dual-luciferase reporter assay. In vitro splenic lymphocytes from mice and peripheral blood mononuclear cells (PBMCs) from healthy individuals were cultured and treated with miR-124-3p mimic/inhibitor. Twenty-four female C57BL/C mice were divided into four groups: control, AR model, miR-124-3p agomir, and miR-124-3p antagomir groups ( n = 6 per group). The allergic responses were evaluated based on the number of sneezing and nasal scratching, the serum HDM-specific IgE (sIgE) levels, and the degree of nasal mucosa eosinophil infiltration. The expression of IL-4Rα, p-STAT6, and type 2 inflammatory cytokines (IL-4, IL-5 and IL-13) in lymphocytes or nasal mucosa was determined by qPCR, western blotting, flow cytometry, immunohistochemistry and immunofluorescence. Results miR-124-3p directly targets the 3'UTR of IL-4Rα. The miR-124-3p mimic lowered the IL-4Rα, p-STAT6, IL-4, IL-5, and IL-13 expression levels in both mouse splenic lymphocytes and human PBMCs in vitro, and the miR-124-3p inhibitor rescued these changes. Furthermore, the miR-124-3p agomir decreased the levels of IL-4Rα and IL-4 in nasal mucosa, Th2 differentiation in spleen, and allergic response in AR mice. Moreover, the miR-124-3p antagonist increased the IL-4Rα and IL-4 levels and further aggravated the allergic responses. Conclusions miR-124-3p might attenuate type 2 inflammation in AR by regulating IL-4Rα signaling, and miR-124-3p may be a promising new target in AR treatment.

Objectives We employed the co-culture of CD34⁺ stem cell-derived human mast cells (HMC) and human monocyte-derived osteoclast precursors to evaluate if mast cells contribute to the pathogenesis of osteoporosis through regulation of osteoclast proliferation and activation. Methods Mature HMC and osteoclast precursors were cultured from monocytes isolated from human buffy coat. The osteoclast precursors were incubated with HMC or receptor activator of nuclear factor kappa-B ligand (RANKL) for a week prior to determination of osteoclast maturation through characterization by their morphology and tartrate resistant acid phosphatase (TRAP) expression. The bone absorption activity was determined by pit formation on osteo-assay plate. Results Mature osteoclasts were identified following co-culture of osteoclast precursors with HMC for one week in the absence of RANKL and they were capable of bone resorption. These actions of HMC on osteoclasts were not affected by mast cell activators such anti-IgE or substance P but could be reversed by osteoprotegerin (OPG) in the co-culture system suggesting the involvement of RANKL. The expression of RANKL on the cell surface of HMC was confirmed by flow cytometry and the density was not affected by activation of HMC. Conclusion Our study provided direct evidence confirming the initiation of osteoclast proliferation and activation by mast cells through cell surface RANKL suggesting that mast cells may contribute to bone destruction in pathological conditions such as osteoporosis.

Background The development of inflammatory bowel diseases is thought to be multifactorial, but the exact steps in pathogenesis are poorly understood. In this study, we investigated involvement of the activation of STAT1 signal pathway in the pathogenesis of an acute colitis model. Methods A dextran sulfate sodium-induced acute colitis model was established by using wild-type C57BL/6 mice and STAT1-deficient mice. Disease indicators such as body weight loss and clinical score, induction of cytokines, chemokines, and inflammatory cells were evaluated in the acute colitis model. Results Disease state was significantly improved in the acute colitis model using STAT1-deficient mice compared with wild-type mice. The induction of Ly6c-highly expressing cells in colorectal tissues was attenuated in STAT1-deficient mice. IL-6, CCL2, and CCR2 gene expressions in Ly6c-highly expressing cells accumulated in the inflamed colon tissues and were significantly higher than in Ly6c-intermediate-expressing cells, whereas TNF-α and IFN-α/β gene expression was higher in Ly6c-intermediate-expressing cells. Blockade of CCR2-mediated signaling significantly reduced the disease state in the acute colitis model. Conclusions Two different types of Ly6c-expressing macrophages are induced in the inflamed tissues through the IFN-α/β-STAT1-mediated CCL2/CCR2 cascade and this is associated with the pathogenesis such as onset, exacerbation, and subsequent chronicity of acute colitis.

Background Sepsis is an abnormal immune-inflammatory response that is mainly caused by infection. It can lead to life-threatening organ dysfunction and death. Severely damaged tissue cells will release intracellular histones into the circulation as damage-related molecular patterns (DAMPs) to accelerate the systemic immune response. Although various histone-related cytotoxicity mechanisms have been explored, those that affect extracellular histones involved in vascular smooth muscle cell (VSMC) dysfunction are yet to be determined. Methods Mouse aortic vascular smooth muscle cells (VSMCs) were stimulated with different concentrations of histones, and cell viability was detected by CCK-8 assay. Cellular senescence was assessed by SA β-gal staining. C57BL/6 mice were treated with histones with or without BML-275 treatment. RT-qPCR was performed to determine the expression of inflammatory cytokines. Western blotting was used to analyze the expression of NLRP3, ASC and caspase-1 inflammasome proteins. The interaction of NLRP3 and ASC was detected by CoIP and immunofluorescence staining. Results In this study, we found that extracellular histones induced senescence and inflammatory response in a dose-dependent manner in cultured VSMCs. Histone treatment significantly promoted apoptosis-associated speck-like protein containing CARD (ASC) as well as NACHT, LRR and PYD domains-containing protein 3 (NLRP3) interaction of inflammasomes in VSMCs. Forkhead box protein O4 (FOXO4), which is a downstream effector molecule of extracellular histones, was found to be involved in histone-regulated VSMC inflammatory response and senescence. Furthermore, the 5'-AMP-activated protein kinase (AMPK) signaling pathway was confirmed to mediate extracellular histone-induced FOXO4 expression, and blocking this signaling pathway with an inhibitor can suppress vascular inflammation induced by extracellular histones in vivo and in vitro. Conclusion Extracellular histones induce inflammation and senescence in VSMCs, and blocking the AMPK/FOXO4 pathway is a potential target for the treatment of histonemediated organ injury.

Background Previous studies reported that IL-38 was abnormally expressed in patients with systemic lupus erythematosus (SLE). However, the involvement of IL-38 in the pathophysiology of SLE remains unknown. Methods The therapeutic potential of IL-38 was tested in pristane-treated wild-type (WT) and IL-38−/− mice. Thus, SLE was induced via pristane in WT and IL-38−/− mice. Afterwards, the liver, spleen, and kidney of each mouse were obtained. The flow cytometric analysis of the immune cells, serologic expression of inflammatory cytokines and autoantibodies, renal histopathology, and inflammatory signaling were evaluated. Results WT mice with pristane-induced lupus exhibited hepatomegaly, splenomegaly, severe kidney damages, increased lymphoproliferation, enhanced lymphoproliferation, and upregulated inflammatory cytokines, such as IL-6, IL-13, IL-17A, MIP-3α, IL-12p70, and IFNγ, and elevated levels of autoantibodies, such as ANA IgG, anti-dsDNA IgG, and total IgG. IL-38−/− mice whose lupus progressed, had elevated cells of CD14⁺, CD19⁺, CD3⁺, and Th1, upregulated inflammatory cytokines and autoantibodies, and severe pathological changes in kidney. Administration of recombinant murine IL-38 to pristane-treated IL-38−/− mice improved their renal histopathology, which depended on ERK1/2, JNK1/2, p38, NF-κB p65, and STAT5 signaling pathways. Conclusion IL-38 regulates SLE pathogenesis. Furthermore, targeting IL-38 is critical in the treatment of SLE.

Objective and design A cross-sectional single-center study was conducted to assess cytokine levels in aqueous humor (AH) and plasma of three different uveitis entities: definite ocular sarcoidosis (OS), definite OS associated with QuantiFERON®-TB Gold test positivity (Q + OS) and presumed tubercular uveitis (TBU). Subjects Thirty-two patients (15 OS, 5 Q + OS, 12 TBU) were included. Methods Quantification of selected cytokines was performed on blood and AH samples collected before starting any treatment. Statistical analysis was conducted using the Kruskal–Wallis test, the Mann–Whitney or Fisher test and the Principal Component Analysis (PCA). Results IL-6, IL-8 and IP-10 levels were higher in AH samples than in peripheral blood. In AH samples, BLC, IL-8 and IP-10 were significantly higher in definite OS than in presumptive TBU. There were no statistically significant differences in terms of cytokine levels between Q + OS and presumptive TBU. PCA showed a similar cytokine pattern in the latter two groups (IFNγ, IL-15, IL-2, IP-10, MIG), while the prevalent expression of BLC, IL-10 and MIP-3 α was seen in definite OS. Conclusions The different AH and plasma cytokine profiles observed in OS compared to Q + OS and TBU may help to differentiate OS from TBU in overlapping clinical phenotypes of granulomatous uveitis (Q + OS).

A global pandemic has erupted as a result of the new brand coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This pandemic has been consociated with widespread mortality worldwide. The antiviral immune response is an imperative factor in confronting the recent coronavirus disease 2019 (COVID-19) infections. Meantime, cytokines recognize as crucial components in guiding the appropriate immune pathways in the restraining and eradication of the virus. Moreover, SARS-CoV-2 can induce uncontrolled inflammatory responses characterized by hyper-inflammatory cytokine production, which causes cytokine storm and acute respiratory distress syndrome (ARDS). As excessive inflammatory responses are contributed to the severe stage of the COVID-19 disease, therefore, the pro-inflammatory cytokines are regarded as the Achilles heel during COVID-19 infection. Among these cytokines, interleukin (IL-) 1 family cytokines (IL-1, IL-18, IL-33, IL-36, IL-37, and IL-38) appear to have a strong inflammatory role in severe COVID-19. Hence, understanding the underlying inflammatory mechanism of these cytokines during infection is critical for reducing the symptoms and severity of the disease. Here, the possible mechanisms and pathways involved in inflammatory immune responses are discussed.

Background Excessive exposure of the skin to UV radiation (UVR) triggers a remodeling of the immune system and leads to the photoaging state which is reminiscent of chronological aging. Over 30 years ago, it was observed that UVR induced an immunosuppressive state which inhibited skin contact hypersensitivity. Methods Original and review articles encompassing inflammation and immunosuppression in the photoaging and chronological aging processes were examined from major databases including PubMed, Scopus, and Google Scholar. Results Currently it is known that UVR treatment can trigger a cellular senescence and inflammatory state in the skin. Chronic low-grade inflammation stimulates a counteracting immunosuppression involving an expansion of immunosuppressive cells, e.g., regulatory T cells (Treg), myeloid-derived suppressor cells (MDSC), and regulatory dendritic cells (DCreg). This increased immunosuppressive activity not only suppresses the function of effector immune cells, a state called immunosenescence, but it also induces bystander degeneration of neighboring cells. Interestingly, the chronological aging process also involves an accumulation of pro-inflammatory senescent cells and signs of chronic low-grade inflammation, called inflammaging. There is also clear evidence that inflammaging is associated with an increase in anti-inflammatory and immunosuppressive activities which promote immunosenescence. Conclusion It seems that photoaging and normal aging evoke similar processes driven by the remodeling of the immune system. However, it is likely that there are different molecular mechanisms inducing inflammation and immunosuppression in the accelerated photoaging and the chronological aging processes.

Background The aim of this study is to investigate role of Visfatin, one of the pro-inflammatory adipokines, in sepsis-induced intestinal injury and to clarify the potential mechanism. Methods C57BL/6 mice underwent cecal ligation and puncture (CLP) surgery to establish sepsis model in vivo. Intestinal epithelial cells were stimulated with LPS to mimic sepsis-induced intestinal injury in vitro. FK866 (the inhibitor of Visfatin) with or without XMU-MP-1 (the inhibitor of Hippo signaling) was applied for treatment. The expression levels of Visfatin, NF-κB and Hippo signaling pathways-related proteins were detected by western blot or immunohistochemistry. The intestinal cell apoptosis and intestinal injury were investigated by TUNEL staining and H&E staining, respectively. ELISA was used to determine the production of inflammatory cytokines. Results The expression of Visfatin increased in CLP mice. FK866 reduced intestinal pathological injury, inflammatory cytokines production, and intestinal cell apoptosis in sepsis mice. Meanwhile, FK866 affected NF-κB and Hippo signaling pathways. Additionally, the effects of FK866 on inflammatory response, apoptosis, Hippo signaling and NF-κB signaling were partly abolished by XMU-MP-1, the inhibitor of Hippo signaling. In vitro experiments also revealed that FK866 exhibited a protective role against LPS-induced inflammatory response and apoptosis in intestinal cells, as well as regulating NF-κB and Hippo signaling, whereas addition of XMU-MP-1 weakened the protective effects of FK866. Conclusion In short, this study demonstrated that inhibition of Visfatin might alleviate sepsis-induced intestinal injury through Hippo signaling pathway, supporting a further research on Visfatin as a therapeutic target.

Objective and design Mesenchymal stromal cells (MSCs) are currently used in cell reparative medicine due to their trophic and ant-inflammatory properties. The modulation of stem cell properties by phytochemicals has been suggested as a tool to empower their tissue repair capacity. In vitro, MSCs are characterized by their tri-lineage potential that holds great interest for tissue regeneration. Ptychotis Verticillata (PV), an aromatic and medicinal plant, may be thus used to modulate the in vitro multilineage potential of MSCs. Materials and methods We screened the impact of PV-derived essential oil and their bioactive molecules (thymol and carvacrol) on the in vitro multilineage potential of MSCs. Different concentrations and incubation times of these compounds were assessed during the osteogenesis and adipogenesis of MSCs. Results The analysis of 75 conditions indicates that these compounds are biologically active by promoting two major differentiation lineages from MSCs. In a time- and dose-dependent manner, thymol and carvacrol increased the osteogenesis and adipogenesis. Conclusion According to these preliminary observations, the addition of PV extract may stimulate the tissue regenerative and repair functions of MSCs. Further optimization of compound extraction and characterization from PV as well as cell treatment conditions should increase their therapeutic value in combination with MSCs.

Background Inflammation and metabolic syndrome (MetS) may act synergistically and possibly accelerate the initiation and progression of colorectal cancer (CRC). We prospectively examined the joint effect of MetS and inflammation on the risk of CRC. Methods We studied 92,770 individuals from the Kailuan study. MetS was defined based on the presence of three or more of the following components. (1) high glucose: FPG > 5.6 mmol/L; (2) high blood pressure: SBP ≥ 130 mmHg or DBP ≥ 85 mmHg; (3) high triglycerides: triglycerides > 1.69 mmol/L; (4) low HDL-C: HDL-C < 1.04 mmol/L in men or 1.29 mmol/L in women; and (5) visceral adiposity: waist circumference ≥ 85 cm in men or 80 cm in women. Inflammation was defined as hs-CRP ≥ 3 mg/L. We divided participants into four groups for the primary exposure according to the presence/absence of inflammation and presence/absence of MetS. Cox proportional hazards regression models were used to evaluate the association of MetS and/or inflammation with the risk of CRC. Results Compared with metabolically healthy noninflammatory individuals, inflammatory participants without MetS and inflammatory participants with MetS were associated with a 1.3-fold and 4.18-fold increased risk of CRC with corresponding HRs (95% CI) of 1.34 (1.09, 1.64) and 4.18 (3.11, 5.62), respectively. The combination of MetS and inflammation was associated with the highest risk of CRC in all subgroups, especially among participants who were female, in younger age, and obese. Sensitivity analyses further validated our primary findings. Conclusions We found the combination of MetS and inflammation could significantly increase the risk of CRC. Including CRP in the diagnosis of MetS may help to identify additional high-risk participants who should be targeted for early diagnosis and prevention of CRC. Trial registration Kailuan study, ChiCTR–TNRC–11001489. Registered 24 August, 2011-Retrospectively registered, http:// www.chictr.org.cn/showprojen.aspx?proj=8050

Chronic obstructive pulmonary disease (COPD) is a progressive lung disorder with substantial patient burden and leading cause of death globally. Cigarette smoke remains to be the most recognised causative factor behind COPD pathogenesis. Given the alarming increase in prevalence of COPD amongst non-smokers in recent past, a potential role of air pollution particularly particulate matter (PM) in COPD development has gained much attention of the scientists. Indeed, several epidemiological studies indicate strong correlation between airborne PM and COPD incidence/exacerbations. PM-induced oxidative stress seems to be the major player in orchestrating COPD inflammatory cycle but the exact molecular mechanism(s) behind such a process are still poorly understood. This may be due to the complexity of multiple molecular pathways involved. Oxidative stress-linked mitochondrial dysfunction and autophagy have also gained importance and have been the focus of recent studies regarding COPD pathogenesis. Accordingly, the present review is aimed at understanding the key molecular players behind PM-mediated COPD pathogenesis through analysis of various experimental studies supported by epidemiological data to identify relevant preventive/therapeutic targets in the area.

The human immunity-related GTPase M (IRGM) is a GTP-binding protein that regulates selective autophagy including xenophagy and mitophagy. IRGM impacts autophagy by (1) affecting mitochondrial fusion and fission, (2) promoting the co-assembly of ULK1 and Beclin 1, (3) enhancing Beclin 1 interacting partners (AMBRA1, ATG14L1, and UVRAG), (4) interacting with other key proteins (ATG16L1, p62, NOD2, cGAS, TLR3, and RIG-I), and (5) regulating lysosomal biogenesis. IRGM also negatively regulates NLRP3 inflammasome formation and therefore, maturation of the important pro-inflammatory cytokine IL-1β, impacting inflammation and pyroptosis. Ultimately, this affords protection against chronic inflammatory diseases. Importantly, ten IRGM polymorphisms (rs4859843, rs4859846, rs4958842, rs4958847, rs1000113, rs10051924, rs10065172, rs11747270, rs13361189, and rs72553867) have been associated with human inflammatory disorders including cancer, which suggests that these genetic variants are functionally relevant to the autophagic and inflammatory responses. The current review contextualizes IRGM, its modulation of autophagy, and inflammation, and emphasizes the role of IRGM as a cross point of immunity and tumorigenesis.

Background Inflammation is widely recognized as the driving force of cachexia induced by chronic diseases; however, therapies targeting inflammation do not always reverse cachexia. Thus, whether inflammation per se plays an important role in the clinical course of cachectic patients is still a matter of debate. Aims To give new insights into cachexia’s pathogenesis and diagnosis, we performed a comprehensive literature search on the contribution of inflammatory markers to this syndrome, focusing on the noncommunicable diseases cancer and cardiovascular diseases. Methods A systematic review was performed in PubMed using the keywords (“cancer” OR “cardiac” cachexia AND “human” OR “patient” AND “plasma” or “serum”). A total of 744 studies were retrieved and, from these, 206 were selected for full-text screening. In the end, 98 papers focusing on circulating biomarkers of cachexia were identified, which resulted in a list of 113 different mediators. Results Data collected from the literature highlight the contribution of interleukin-6 (IL-6) and C-reactive protein (CRP) to cachexia, independently of the underlying condition. Despite not being specific, once the diagnosis of cachexia is established, CRP might help to monitor the effectiveness of anti-cachexia therapies. In cardiac diseases, B-type natriuretic peptide (BNP), renin, and obestatin might be putative markers of body wasting, whereas in cancer, growth differentiation factor (GDF) 15, transforming growth factor (TGF)-β1 and vascular endothelial growth factor (VEGF) C seem to be better markers of this syndrome. Independently of the circulating mediators, NF-κB and JAK/STAT signaling pathways play a key role in bridging inflammation with muscle wasting; however, therapies targeting these pathways were not proven effective for all cachectic patients. Conclusion The critical and integrative analysis performed herein will certainly feed future research focused on the better comprehension of cachexia pathogenesis toward the improvement of its diagnosis and the development of personalized therapies targeting specific cachexia phenotypes.

Background Fos-related antigen-2 (Fra-2) is a transcription factor belonging to the activator protein 1 (AP-1) family, which is associated with many chronic airway diseases such as asthma. Alternatively activated (M2) macrophages are associated with Fra2 in airway diseases such as pulmonary fibrosis. However, there is no specific study that explores the relationship between M2 macrophages and Fra2 in asthma. Objective We hypothesized that a potential mechanism of allergic asthma could be that Fra2 is highly expressed in M2 macrophages through JAK3–STAT5 and facilitates the production of downstream T-helper 2 (Th2) cytokines, thus promoting the pathogenesis of asthma. Methods Peripheral venous blood and airway tissue samples of patients with asthma and controls were obtained. Moreover, a C57BL/6 mouse model of asthma was established. Fra2 expression was detected using immunohistochemistry and immunofluorescence. Macrophages were obtained by flow sorting, and expression of the JAK3–STAT5–Fra2 signaling pathway was determined using PCR and western blotting. Enzyme-linked immunosorbent assay was used to determine M2 macrophage-associated Th2-type cytokine levels. Results Fra2 was highly expressed in patients with asthma and asthmatic mice. The JAK3–STAT5 was a signal pathway related to the high expression of Fra2 in M2 macrophages. Moreover, we found that Fra2 could affect the production of Th2 cytokines downstream of M2 macrophages, including interleukin 4 (IL-4) and IL-13. Conclusion M2 macrophages could promote airway inflammation through JAK3–STAT5–Fra2 to induce allergic asthma. Our study offers a new insight to further understand the pathogenesis of asthma and also provides a new direction for targeted treatment.

Objective Microglial hyperactivation and apoptosis were observed following myocardial infarction and ischemia reperfusion (I/R) injury. This study aimed to test the hypothesis that the apoptosis inhibitor, Z-VAD, attenuates microglial and astrocytic hyperactivation and brain inflammation in rats with cardiac I/R injury. Materials and methods Rats were subjected to either sham or cardiac I/R operation (30 min-ischemia followed by 120-min reperfusion), rats in the cardiac I/R group were given either normal saline solution or Z-VAD at 3.3 mg/kg via intravenous injection 15 min prior to cardiac ischemia. Left ventricular ejection fraction (% LVEF) was determined during the cardiac I/R protocol. The brain tissues were removed and used to determine brain apoptosis, brain inflammation, microglial and astrocyte morphology. Results Cardiac dysfunction was observed in rats with cardiac I/R injury as indicated by decreased %LVEF. In the brain, we found brain apoptosis, brain inflammation, microglia hyperactivation, and reactive astrogliosis occurred following cardiac I/R injury. Pretreatment with Z-VAD effectively increased %LVEF, reduced brain apoptosis, attenuated brain inflammation by decreasing IL-1β mRNA levels, suppressed microglial and astrocytic hyperactivation and proliferation after cardiac I/R injury. Conclusion Z-VAD exerts neuroprotective effects against cardiac I/R injury not only targeting apoptosis but also microglial and astrocyte activation.

Type 2 diabetes mellitus (T2DM) is an important chronic disease around the world, and according to the World Health Organization, it is the 9th principal cause of global death. This pathology is characterized by high levels of circulating glucose as a result of insulin resistance, and it is well stated that inflammation related to obesity is directly associated with the development of the disease. The purinergic signalling is involved in both pancreatic destruction, which impairs insulin secretion, and the cytokine production that favors insulin resistance in T2DM. In this review, the purinergic signalling aspects will be discussed, showing the impact of the enzymes, nucleotides, nucleosides, and receptors of this system and the cytokines that result in inflammation, in the development and progression of T2DM, besides, pointing the purinergic receptors as a possible therapeutic approach.

Background Exosomes derived from bone mesenchymal stem cells (BMSCs) are potential candidates for inflammatory bowel disease (IBD) treatment. The present study investigated the therapeutic effect and potential mechanism of BMSCs-derived exosomes on pyroptosis in IBD. Methods We induced IBD in mice and cell models through dextran sulfate sodium (DSS) and LPS, respectively. The mRNA and protein expression levels were assessed by qRT–PCR, Western blotting, IF and IHC. The concentrations of IL-1β, IL-18 and TNFα were assessed using ELISA. ROS levels were determined using DCFH-DA staining. Cell proliferation of mIECs was analysed using an MTT assay. In addition, a flow cytometry assay was performed to detect pyroptosis. Finally, the binding relationship between miR-539-5p and NLRP3 was verified by a dual luciferase reporter gene assay. Results Our results revealed that intraperitoneal injection of BMSCs-derived exosomes inhibited DSS-induced pyroptosis as well as IBD symptoms in mice. In addition, BMSCs-derived exosome treatment suppressed pyroptosis, ROS levels and the concentrations of proinflammatory cytokines (IL-1β, IL-18 and TNFα) in LPS-treated mIECs in a miR-539-5p-dependent manner. Further research found that miR-539-5p suppressed NLRP3 expression in mIECs by directly targeting NLRP3. As expected, pyroptosis in LPS-treated mIECs was significantly reduced by NLRP3 knockdown. In addition, NLRP3 silencing restored the inhibitory effect of exosomes derived from BMSCs transfected with miR-539-5p inhibitor on pyroptosis in LPS-treated mIECs. Conclusion The present study demonstrated that BMSCs-derived exosomal miR-539-5p suppresses pyroptosis through NLRP3/caspase-1 signalling to inhibit IBD progression.

Introduction Several experimental models have been designed to promote the development of new anti-inflammatory drugs. The in vitro model using RAW 264.7 cells has been widely used. However, there is still no consensus on which inflammatory mediators should initially be measured to screen for possible anti-inflammatory effects. To determine the rationality of measuring inflammatory mediators together with NO, such as the levels of tumor necrosis factor (TNF)-α, and interleukins (IL) 1β and 6, we carried out this systematic review (SR) and meta-analysis (MA). Methodology We conducted this SR and MA in accordance with the Preferred Reporting of Systematic Reviews and Meta-Analysis and the Cochrane Handbook for Systematic Reviews of Intervention. This review was registered in the Open Science Framework (https://doi.org/10.17605/OSF.IO/8C3HT). Results LPS-induced cells produced high NO levels compared to non-LPS induced, and this production was not related to cell density. TNF-α, IL-1β, and IL-6, also showed high levels after cells had been stimulated with LPS. Though with some restrictions, all studies were reliable, as the risk of bias was detected in the test compounds and systems. Conclusion Measurement of NO levels may be sufficient to screen for possible anti-inflammatory action in the context of LPS-induced RAW 264.7 cells.

Background Ribosomal protein L38 (RPL38) was found upregulated in osteoarthritic peripheral blood mononuclear cells, however, its role in progression of osteoarthritis has not been characterized. Methods The protein levels of RPL38 and SOCS2 in cartilage tissues from OA patients and controls were detected with Western blotting. IL-1β was used to stimulate primary chondrocytes to establish an OA cell model, and RPL38 siRNA (si-RPL38) was transfected into chondrocytes to investigate the effect of RPL38 knockdown on cell viability, apoptosis, inflammatory factor secretion and extracellular matrix degradation. Then, the mechanism that RPL38 regulate the SOCS2 expression and SOCS2-induced chondrocyte dysfunction was explored. The methyltransferase-like 3 (METTL3)-mediated m6A modification of SOCS2 mRNA was confirmed, and the interaction of RPL38 and METTL3 was verified. Moreover, the effects of SOCS2 overexpression on IL-1β-induced chondrocyte dysfunction and SOCS2 knockdown on the restoration of chondrocyte function by siRPL38 were investigated. Finally, RPL38 was knocked down in vivo and its role in OA progression was validated. Results RPL38 was upregulated and SOCS2 was downregulated in OA cartilages. RPL38 knockdown or SOCS2 overexpression either attenuated IL-1β-induced chondrocyte apoptosis, inflammatory cytokine secretion, and ECM degradation. RPL38 directly interacted with METTL3 and it inhibited SOCS2 expression through METTL3-mediated m6A modification. SOCS2 knockdown activated the JAK2/STAT3 proinflammatory pathway and reversed the effects of RPL38 knockdown on IL-1β-induced chondrocyte apoptosis, inflammation and ECM degradation. RPL38 knockdown alleviated cartilage tissue damage and ECM degradation in OA mice. Conclusion RPL38 knockdown inhibited osteoarthritic chondrocyte dysfunction and alleviated OA progression through promoting METTL3-m6A-mediated SOCS2 expression.

Objectives: We identified functional genes and studied the underlying molecular mechanisms of diabetic cardiomyopathy (DCM) using bioinformatics tools. Methods: Original gene expression profiles were obtained from the GSE21610 and GSE112556 data sets. We used GEO2R to screen the differentially expressed genes (DEGs). Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses were performed on DEGs. Protein-protein interaction (PPI) networks of DEGs were constructed using STRING and hub genes of signaling pathways were identified using Cytoscape. Aberrant hub gene expression was verified using The Cancer Genome Atlas data set. Results: The DEGs in DCM were mainly enriched in the nuclei and cytoplasm and involved in DCM and chemokine-related signaling pathways. In the PPI network, 32 nodes were chosen as hub nodes and an RNA interaction network was constructed with 517 interactions. The expression of key genes (JPIK3R1, CCR9, XIST, WDFY3.AS2, hsa-miR-144-5p, and hsa-miR-146b-5p) was significantly different between DCM and normal tissues. Conclusions: The identified hub genes could be associated with DCM pathogenesis and could be used for treating DCM.

Background Acute pancreatitis (AP) is an inflammatory process of the pancreas resulting from biliary obstruction or alcohol consumption. Approximately, 10–20% of AP can evolve into severe AP (SAP). In this study, we sought to explore the physiological roles of the transcription factor serum response factor (SRF), annexin A2 (ANXA2), and nuclear factor-kappaB (NF-κB) in SAP. Methods C57BL/6 mice and rat pancreatic acinar cells (AR42J) were used to establish an AP model in vivo and in vitro by cerulein with or without lipopolysaccharide (LPS). Production of pro-inflammatory cytokines (IL-1β and TNF-α) were examined by ELISA and immunoblotting analysis. Hematoxylin and eosin (HE) staining and TUNEL staining were performed to evaluate pathological changes in the course of AP. Apoptosis was examined by flow cytometric and immunoblotting analysis. Molecular interactions were tested by dual luciferase reporter, ChIP, and Co-IP assays. Results ANXA2 was overexpressed in AP and correlated to the severity of AP. ANXA2 knockdown rescued pancreatic acinar cells against inflammation and apoptosis induced by cerulein with or without LPS. Mechanistic investigations revealed that SRF bound with the ANXA2 promoter region and repressed its expression. ANXA2 could activate the NF-κB signaling pathway by inducing the nuclear translocation of p50. SRF-mediated transcriptional repression of ANXA2-protected pancreatic acinar cells against AP-like injury through repressing the NF-κB signaling pathway. Conclusion Our study highlighted a regulatory network consisting of SRF, ANXA2, and NF-κB that was involved in AP progression, possibly providing some novel targets for treating SAP.

Background SARS-CoV-2 is a highly infectious respiratory virus associated with coronavirus disease (COVID-19). Discoveries in the field revealed that inflammatory conditions exert a negative impact on bone metabolism; however, only limited studies reported the consequences of SARS-CoV-2 infection on skeletal homeostasis. Inflammatory immune cells (T helper—Th17 cells and macrophages) and their signature cytokines such as interleukin (IL)-6, IL-17, and tumor necrosis factor-alpha (TNF-α) are the major contributors to the cytokine storm observed in COVID-19 disease. Our group along with others has proven that an enhanced population of both inflammatory innate (Dendritic cells—DCs, macrophages, etc.) and adaptive (Th1, Th17, etc.) immune cells, along with their signature cytokines (IL-17, TNF-α, IFN-γ, IL-6, etc.), are associated with various inflammatory bone loss conditions. Moreover, several pieces of evidence suggest that SARS-CoV-2 infects various organs of the body via angiotensin-converting enzyme 2 (ACE2) receptors including bone cells (osteoblasts—OBs and osteoclasts—OCs). This evidence thus clearly highlights both the direct and indirect impact of SARS-CoV-2 on the physiological bone remodeling process. Moreover, data from the previous SARS-CoV outbreak in 2002–2004 revealed the long-term negative impact (decreased bone mineral density—BMDs) of these infections on bone health. Methodology We used the keywords “immunopathogenesis of SARS-CoV-2,” “SARS-CoV-2 and bone cells,” “factors influencing bone health and COVID-19,” “GUT microbiota,” and “COVID-19 and Bone health” to integrate the topics for making this review article by searching the following electronic databases: PubMed, Google Scholar, and Scopus. Conclusion Current evidence and reports indicate the direct relation between SARS-CoV-2 infection and bone health and thus warrant future research in this field. It would be imperative to assess the post-COVID-19 fracture risk of SARS-CoV-2-infected individuals by simultaneously monitoring them for bone metabolism/biochemical markers. Importantly, several emerging research suggest that dysbiosis of the gut microbiota—GM (established role in inflammatory bone loss conditions) is further involved in the severity of COVID-19 disease. In the present review, we thus also highlight the importance of dietary interventions including probiotics (modulating dysbiotic GM) as an adjunct therapeutic alternative in the treatment and management of long-term consequences of COVID-19 on bone health.

At least 17 million people die from acute myocardial infarction (AMI) every year, ranking it first among causes of death of human beings, and its incidence is gradually increasing. Typical characteristics of AMI include acute onset and poor prognosis. At present, there is no satisfactory treatment, but development of coronary collateral circulation (CCC) can be key to improving prognosis. Recent research indicates that the levels of cytokines, including those related to promoting inflammatory responses and angiogenesis, increase after the onset of AMI. In the early phase of AMI, cytokines play a vital role in inducing development of collateral circulation. However, when myocardial infarction is decompensated, cytokine secretion increases greatly, which may induce a cytokine storm and worsen prognosis. Cytokines can regulate the activation of a variety of signal pathways and form a complex network, which may promote or inhibit the establishment of collateral circulation. We searched for published articles in PubMed and Google Scholar, employing the keyword “acute myocardial infarction”, “coronary collateral circulation” and “cytokine storm”, to clarify the relationship between AMI and a cytokine storm, and how a cytokine storm affects the growth of collateral circulation after AMI, so as to explore treatment methods based on cytokine agents or inhibitors used to improve prognosis of AMI.

Objective Apoptosis plays a major role in the progression of acute respiratory distress syndrome (ARDS) that may involve the interaction of the high mobility group box 1 (HMGB1) protein with the receptor for advanced glycation end products (RAGE). However, the underlying mechanism remains unclear. Thus, we aimed to explore the mechanisms of HMGB1-RAGE axis-induced apoptosis in ARDS. Methods Blood samples from ARDS patients and healthy volunteers were collected to investigate the correlation between serum HMGB1 levels and the severity of ARDS in patients. Mouse models of ARDS induced by caecal ligation and perforation and A549 cell models established by stimulation with recombinant human HMGB1 (rHMGB1) were designed to explore lung inflammatory injury and apoptosis. Results Serum HMGB1 levels were significantly increased in ARDS patients compared to controls, and HMGB1 levels in the Severe group and Nonsurvival group were significantly higher than those in the Mild and Moderate group and Survival group. In vivo, compared to sham mice, ARDS mice showed significant lung inflammatory injury and apoptosis as well as upregulation of HMGB1 and RAGE and endoplasmic reticulum stress (ERs) protein expression. All injury was attenuated by treatment with an HMGB1 inhibitor GA, a RAGE blocker FPS-ZM1, and an ERs inhibitor 4-PBA. In vitro, A549 cells challenged with rHMGB1 exhibited significant increases in the levels of proteins in the RNA-like endoplasmic reticulum kinase (PERK)/eukaryotic initiation factor 2alpha (eIF2α)/activating transcription factor 4 (ATF4) pathway and in apoptosis, all of which were significantly inhibited by pre-treatment with lenti-shPERK and an anti-RAGE antibody. Conclusion The HMGB1-RAGE axis induces apoptotic injury during ARDS, possibly through PERK/eIF2α/ATF4-mediated ERs.

In this study, we describe the kinetics of a new potential inflammatory biomarker, presepsin, together with a panel of well-established biomarkers in a human endotoxemia study. We evaluated biomarker correlations and identified combinations that could hold valuable insights regarding the state of infection.

Background Coronary artery disease (CAD) seriously disturbs the life of people. LncRNA H19 is reported to promote the progression of CAD; Nevertheless, the detailed mechanism by which H19 modulates CAD development is unclear. Methods Clinical samples of CAD patients were collected, meanwhile we established in vitro and in vivo models of CAD by treating HCAECs with ox-LDL and feeding ApoE−/− mice with high fat diets (HFD). MTT assay was adopted to assess the cell viability. Transwell detection was applied to test the migration, and apoptosis was tested by flow cytometry. The levels of inflammatory cytokines were examined by ELISA. The relation among H19, miR-20a-5p and HDAC4 was explored by dual luciferase reporter and RIP assay. Results H19 and HDAC4 levels were elevated, while miR-20a-5p was reduced in plasma of CAD patients and ox-LDL-treated HCAECs. ox-LDL increased H19 level and induced apoptosis and inflammation in HCAECs, while silencing of H19 rescued this phenomenon. In addition, the level of H19 was negatively correlated with miR-20a-5p, and miR-20a-5p inhibitor restored the effect of H19 silencing on HCAECs function. HDAC4 was the downstream mRNA of miR-20a-5p, and miR-20a-5p upregulation reversed ox-LDL-induced HCAECs injury through targeting HDAC4. Furthermore, H19 silencing significantly alleviated the coronary atherosclerotic plaques and inhibited the inflammatory responses in vivo. Conclusions We proved that knockdown of H19 alleviated ox-LDL-induced HCAECs injury via miR-20a-5p/HDAC4 axis, which might provide a new tactics against CAD.

Objective: This study aimed to investigate the direct role of IL-25 in modulating adipocyte function during homeostasis and low-grade inflammation induced by lipopolysaccharide (LPS). Methods: The 3T3-L1 preadipocyte cell lines and primary cultures of adipose-derived stromal vascular precursor cells of wild-type and IL-17RB-deficient mice were used to determine the direct function of IL-25. The expression of IL-17RB in differentiating adipocyte was determined using real-time PCR and flow cytometry analysis. The effect of IL-25 on lipid accumulation, triglyceride content, lipolysis, glucose uptake, and adipokine expression in the mature adipocytes was evaluated. IL-25 modulating the expression of inflammatory cytokines in adipocytes induced by low dose LPS was determined using real-time PCR and ELISA. Results: The receptor for IL-25 was up-regulated during adipocyte differentiation and IL-25 directly modulated adipocyte function by reducing lipid accumulation and triglyceride concentration and enhancing lipolysis without affecting an insulin-stimulated glucose uptake. Interestingly, IL-25 induced adiponectin secretion through the PI3K/AKT signaling pathway. In 3T3-L1 adipocytes under low-grade inflammation, IL-25 attenuated the expression of IL-6 and CCL5 through the induction of adiponectin. Conclusion: Our studies suggest that IL-25 directly regulates adipocyte function by maintaining the adiponectin level during homeostasis and by alleviating inflammatory response through the regulation of adiponectin during low-grade inflammation in adipocytes.

Endotoxin-induced acute lung injury (ALI) is a challenging life-threatening disease for which no specific therapy exists. Mitochondrial dysfunction is corroborated as hallmarks in sepsis which commonly disrupt mitochondria-centered cellular communication networks, especially mitonuclear crosstalk, where the ubiquitous cofactor nicotinamide adenine dinucleotide (NAD⁺) is essential for mitonuclear communication. Heme oxygenase-1 (HO-1) is critical for maintaining mitochondrial dynamic equilibrium and regulating endoplasmic reticulum (ER) and Golgi stress to alleviating acute lung injury. However, it is unclear whether HO-1 regulates NAD⁺-mediated mitonuclear communication to exert the endogenous protection during endotoxin-induced ALI. In this study, we observed HO-1 attenuated endotoxin-induced ALI by regulated NAD⁺ levels and NAD⁺ affected the mitonuclear communication, including mitonuclear protein imbalance and UPRmt to alleviate lung damage. We also found the protective effect of HO-1 depended on NAD⁺ and NAD⁺-mediated mitonuclear communication. Furtherly, the inhibition of the PGC1α/PPARγ signaling exacerbates the septic lung injury by reducing NAD⁺ levels and repressing the mitonuclear protein imbalance and UPRmt. Altogether, our study certified that HO-1 ameliorated endotoxin-induced acute lung injury by regulating NAD⁺ and NAD⁺-mediated mitonuclear communications through PGC1α/PPARγ pathway. The present study provided complementary evidence for the cytoprotective effect of HO-1 as a potential target for preventing and attenuating of endotoxin-induced ALI.

Background/objective Naringenin is a member of the flavonoid family that can perform many biological processes to treat a wide range of inflammatory diseases and pathological conditions related to oxidative stress (OS). Naringenin immunomodulatory activities have been the subject of recent research as an effective alternative treatment for autoimmune disorders. The effects of naringenin on the levels of inflammatory biomarkers and OS factors in animal models of autoimmune disorders (ADs) were studied in this meta-analysis. Methods Up until January 2022, electronic databases such as Cochrane Library and EMBASE, PubMed, Web of Science, and Scopus were used to conduct a comprehensive literature search in English language. To evaluate the effect of naringenin on inflammatory mediators, such as TNF-α, IL-6, IL-β, IFN-γ, NF-κB, and nitric oxide, and OS biomarkers, such as CAT, SOD, GPx, GSH and MDA, in AD models, we measured the quality assessment and heterogeneity test using the PRISMA checklist protocol and I² statistic, respectively. A random-effects model was employed based on the heterogeneity test, and then pooled data were standardized as mean difference (SMD) with a 95% confident interval (CI). Results We excluded all clinical trials, cell experiment studies, animal studies with different parameters, non-autoimmune disease models, and an inadequate series of studies for quantitative synthesis. Finally, from 627 potentially reports, 12 eligible studies were included in the meta-analysis. Data were collected from several groups. Of these, 153 were in the naringenin group and 149 were in the control group. Our meta-analysis of the pooled data for the parameters of inflammation and OS indicated that naringenin significantly reduced the levels of NF-κB (SMD − 3.77, 95% CI [− 6.03 to − 1.51]; I² = 80.1%, p = 0.002), IFN-γ (SMD − 6.18, 95% CI [− 8.73 to − 3.62]; I² = 53.7%, p = 0.115), and NO (SMD − 3.97, 95% CI [− 5.50 to − 2.45]; I² = 73.4%, p = 0.005), IL-1β (SMD − 4.23, 95% CI [− 5.09 to − 3.37]; I² = 0.0%, p = 0.462), IL-6 (SMD − 5.84, 95% CI [− 7.83 to − 3.85]; I² = 86.5%, p < 0.001), and TNF-α (SMD − 5.10, 95% CI [− 6.34 to − 3.86]; I² = 74.7%, p < 0.001). These findings also demonstrated the efficacy of naringenin on increasing the levels of CAT (SMD 4.19, 95% CI [1.33 to 7.06]; I² = 79.9%, p = 0.007), GSH (SMD 4.58, 95% CI [1.64 to 7.51]; I² = 90.5%, p < 0.001), and GPx (SMD 9.65, 95% CI [2.56 to 16.74]; I² = 86.6%, p = 0.001) and decreasing the levels of MDA (SMD − 3.65, 95% CI [− 4.80 to − 2.51]; I² = 69.4%, p = 0.001) than control groups. However, treatment with naringenin showed no statistically difference in SOD activity (SMD 1.89, 95% CI [− 1.11 to 4.89]; I² = 93.6%, p < 0.001). Conclusion Overall, our findings revealed the immunomodulatory potential of naringenin as an alternative treatment on inhibition of inflammation and OS in several autoimmune-related diseases. Nevertheless, regarding the limitation of clinical trials, strong preclinical models and clinical settings in the future are needed that address the effects of naringenin on ADs. Before large-scale clinical studies, precise human pharmacokinetic investigations are required to determine the dosage ranges and evaluate the initial safety profile of naringenin.

Background Acute liver injury is liver cell injury that occurs rapidly in a short period of time. Caffeine has been shown to maintain hepatoprotective effect with an unclear mechanism. Endoplasmic reticulum stress (ERS) has significant effects in acute liver injury. Induction of GRP78 is a hallmark of ERS. Whether or not caffeine’s function is related to GRP78 remains to be explored. Methods Acute liver injury model was established by LPS-treated L02 cells and in vivo administration of LPS/D-Gal in mice. Caffeine was pre-treated in L02 cells or mice. Gene levels was determined by real-time PCR and western blot. Cell viability was tested by CCK-8 assay and cell apoptosis was tested by flow cytometry. The interaction of GRP78 and NEDD4L was determined by Pull-down and co-immunoprecipitation (Co-IP) assay. The ubiquitination by NEDD4L on GRP78 was validated by in vitro ubiquitination assay. Results Caffeine protected liver cells against acute injury induced cell apoptosis and ERS both in vitro and in vivo. Suppression of GRP78 could block the LPS-induced cell apoptosis and ERS. NEDD4L was found to interact with GRP78 and ubiquitinate its lysine of 324 site directly. Caffeine treatment induced the expression of NEDD4L, resulting in the ubiquitination and inhibition of GRP78. Conclusion Caffeine mitigated the acute liver injury by stimulating NEDD4L expression, which inhibited GRP78 expression via ubiquitination at its K324 site. Low dose of caffeine could be a promising therapeutic treatment for acute liver injury.

Objective Mucosal-associated invariant T (MAIT) cells are unique innate-like T cells that are abundant in humans, accounting for 1-10% of circulating T cells and about 2% of total T cells in human oral cavity. MAIT cells can mount a strong immune response quickly without exogenous antigens and undergo a phenotypic transformation in the development of diseases. They produce cytokines involved in the Th1 and Th17 immune response and cytotoxic proteins, promote the dysfunction of autoreactive B cell and inhibit the function of NK cells. MAIT cells have been widely explored in autoimmune diseases, inflammatory diseases and tumors, and these mechanisms may also be involved in the pathogenesis of some oral diseases, while MAIT cells have not been systematically discussed in oral diseases. Methods We searched PubMed/MEDLINE, EMBASE and Microsoft Bing databases to review and analyze relevant literatures on the impact of MAIT cells in the pathogenesis of human oral diseases. Conclusion Collected evidence elucidated the characteristics of MAIT cells and emphasized the potential roles of MAIT cells in oral lichen planus (OLP), chronic graft-versus-host disease (cGVHD), oral squamous cell carcinoma (OSCC), apical periodontitis (AP) and primary Sjogren's syndrome (pSS).

Periodontitis and chronic obstructive pulmonary disease (COPD) are chronic inflammatory diseases with common risk factors, such as long-term smoking, age, and social deprivation. Many observational studies have shown that periodontitis and COPD are correlated. Moreover, they share a common pathophysiological process involving local accumulation of inflammatory cells and cytokines and damage of soft tissues. The T helper 17 (Th17) cells and the related cytokines, interleukin (IL)-17, IL-22, IL-1β, IL-6, IL-23, and transforming growth factor (TGF)-β, play a crucial regulatory role during the pathophysiological process. This paper reviewed the essential roles of Th17 lineage in the occurrence of periodontitis and COPD. The gaps in the study of their common pathological mechanism were also evaluated to explore future research directions. Therefore, this review can provide study direction for the association between periodontitis and COPD and new ideas for the clinical diagnosis and treatment of the two diseases.

In the light of cancellation of the 50th Annual Meeting of the European Histamine Research Society (EHRS) due to continuing challenges and restrictions imposed by the coronavirus disease 2019 (COVID-19) outbreak, the EHRS Council decided to organize a series of online events spread in 2021 to allow dissemination of histamine research progress and advancement among the Society members and beyond. This report summarizes the outcomes of the EHRS Council initiative that comprised the organization of four webinars, each focusing on a highly relevant histamine research scientific area. These included insights into novel therapeutic targets related to the histaminergic system in the eye, histamine intolerance, and the role of histamine and the histaminergic system in the regulation of the nervous system, as well as an update on studies leading to the development of novel methods for histamine detection. The outcome of this series of virtual events conformed that histamine research continued to develop despite the pandemic, and we witnessed stimulating advancements in 2021. Importantly, the EHRS Council brought histaminologists together in this unprecedented time.

Objective Salidroside (SAL) is a marker glycoside of Rhodiola rosea with significant antioxidant, anti-inflammatory, and other health benefits. In this study, we determined its neuroprotective effects against Cd-induced toxicity in cultured cells and mice. Materials and methods GL261 cell and Cd-intoxicated mouse model were used. ICP-MS and MWM were performed to measure Cd content and Cd-induced cognitive impairment in mice, respectively. Results SAL attenuated Cd toxicity in GL261 cells as well as protected mice from substantial organic damage and cognitive deficits. SAL treatment alleviated Cd-induced oxidative stress, glial cell activation, and elevation of pro-inflammatory factors including TNF-α, IL-1β, and IL-6. Cd-induced cognitive deficits observed in the Morris water maze in mice were rescued by SAL. At the mechanistic level, SAL maintained the activity of antioxidant enzymes such as SOD and GSH-Px in the serum and brain, and scavenged the peroxidation product MDA, thereby restoring redox homeostasis in vivo, attenuating neuronal damage, and ultimately antagonized Cd-induced toxicity. Furthermore, Cd activated the RIP1-driven inflammatory signaling pathway and Notch/HES-1 signaling axis in the brain, leading to inflammation and neuronal loss, which could be attenuated by SAL. Conclusion SAL is a natural product with good anti-Cd effects, indicating that Rhodiola rosea is promising plant that is worthy of cultivation for health and economic benefits.

Objective Sitagliptin and other dipeptidyl peptidase (DPP)‐4 inhibitors/gliptins are antidiabetic drugs known to improve lipid profile, and confer anti‐inflammatory and anti‐fibrotic effects, which are independent of their hypoglycemic effects. However, in our previous short-term (35 days) studies, we showed that sitagliptin accentuates the hepato-inflammatory effects of high dietary cholesterol (Cho) in male Sprague–Dawley rats. Since most type 2 diabetics also present with lipid abnormalities and use DPP-4 inhibitors for glucose management, the present study was conducted to assess the impact of sitagliptin during long-term (98 days) feeding of a high Cho diet. An additional component of the present investigation was the inclusion of other gliptins to determine if hepatic steatosis, necro‐inflammation, and fibrosis were specific to sitagliptin or are class effects. Methods Adult male Sprague–Dawley rats were fed control or high Cho (2.0%) diets, and gavaged daily (from day 30 through 98) with vehicle or DPP-4 inhibitors (sitagliptin or alogliptin or saxagliptin). On day 99 after a 4 h fast, rats were euthanized. Blood and liver samples were collected to measure lipids and cytokines, and for histopathological evaluation, determination of hepatic lesions (steatosis, necrosis, inflammation, and fibrosis) using specific staining and immunohistochemical methods. Results Compared to controls, the high Cho diet produced a robust increase in NASH like phenotype that included increased expression of hepatic (Tnfa, Il1b, and Mcp1) and circulatory (TNFα and IL-1β) markers of inflammation, steatosis, necrosis, fibrosis, and mononuclear cell infiltration. These mononuclear cells were identified as macrophages and T cells, and their recruitment in the liver was facilitated by marked increases in endothelium‐expressed cell adhesion molecules. Importantly, treatment with DPP‐4 inhibitors (3 tested) neither alleviated the pathologic responses induced by high Cho diet nor improved lipid profile. Conclusions The potential lipid lowering effects of DPP-4 inhibitors were diminished by high Cho (a significant risk factor for inducing liver damage). The robust inflammatory responses induced by high Cho feeding in long-term experiment were not exacerbated by DPP-4 inhibitors and a consistent hepatic inflammatory environment persisted, implying a prospective physiological adaptation.

Background and objective Chronic obstructive pulmonary disease (COPD) is a chronic airway disease with airflow limitation and abnormal inflammatory response. It has been verified that SOX9 plays a key role in lung function of various lung diseases and SOX9 is closely associated with COPD. Additionally, literature has reported that STIM1 is involved in lung injury and is highly expressed in neutrophils from COPD patients. This study aimed to characterize the biological roles of SOX9 and STIM1 in the pathogenesis of COPD and to elucidate the regulatory mechanism. Methods Human bronchial epithelial cells (BEAS-2B) were treated with CSE to construct in vitro COPD model. The levels of SOX9 and STIM1 in CSE-treated BEAS-2B cells were detected by western blot and RT-qPCR assay. Then, JASPAR datasets were utilized to analyze SOX9 binding sites in the promoter region of STIM1. Besides, luciferase reporter assay and ChIP assay were employed to validate the binding sites in STIM1 promoter region to SOX9. In addition, viability and apoptosis of BEAS-2B cells were assessed by utilizing MTT assay and TUNEL staining. ELISA kits and corresponding commercial kits were applied to measure the levels of TNF-α, IL-6, IL-1β, SOD, GSH-Px and MDA. Results CSE treatment dose- and time-dependently reduced SOX9 expression in BEAS-2B cells. SOX9 overexpression enhanced the viability and suppressed the apoptosis of CSE-treated BEAS-2B cells as well as attenuated CSE-induced inflammation and oxidative stress. Then, it was validated that SOX9 bound to the promoter region of STIM1. Moreover, SOX9 overexpression-mediated impacts on cell viability, cell apoptosis, inflammation and oxidative stress in CSE-treated BEAS-2B cells were partially abolished by upregulation of STIM1. Conclusion To sum up, results here suggested that overexpression of SOX9 could mitigate inflammatory injury in CSE-treated bronchial epithelial cells by suppressing STIM1.

Background Inflammation is a common feature in the pathogenesis of chronic kidney disease (CKD), regardless of the disease cause. Our aim was to evaluate the potential of several inflammatory biomarkers in CKD diagnosis and staging. Methods A total of 24 healthy controls and 92 pre-dialysis CKD patients with diverse etiologies, were enrolled in this study and grouped according to their CKD stage. We analysed the circulating levels of inflammatory molecules, C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), tumor necrosis factor receptor 2 (TNFR2), pentraxin 3 (PTX3) and leptin, as well as the hemogram. We studied their association with parameters of kidney function and kidney injury, to evaluate their potential as early markers of the disease and/or of its worsening, as well as their interplay. Results Compared to controls, patients in CKD stages 1–2 presented significantly higher IL-6 and TNFR2 levels, and higher neutrophil-to-lymphocyte ratio. All inflammatory cytokines and acute-phase proteins showed a trend to increase up to stage 3, stabilizing or declining thereafter, save for TNFR2, which steadily increased from stage to stage. All inflammatory molecules, apart from PTX3, were negatively and significantly correlated with eGFR, with a remarkable value for TNFR2 (r = − 0.732, p < 0.001). Conclusion TNFR2 might be useful for an early detection of CKD, as well as for disease staging/worsening. Still, the potential value of this biomarker in disease progression warrants further investigation.

Objective To comprehensively characterize monocyte and neutrophil responses to E. coli and its product [lipopolysaccharide (LPS) or endotoxin] in vitro during pregnancy. Material or subjects Peripheral blood was collected from pregnant women during the third trimester (n = 20) and from non-pregnant women (n = 20). Methods The number, phagocytic activity, and reactive oxygen species (ROS) production of peripheral monocytes and neutrophils were investigated using flow cytometry. The phenotypes of peripheral monocytes and neutrophils after acute or chronic LPS stimulation were also determined using flow cytometry. Cytokine profiles were quantified for LPS-stimulated peripheral blood mononuclear cells (PBMCs) and a whole blood TruCulture® system using a multiplex immunoassay. Results Increased number, phagocytic activity, and ROS production capacity of monocytes and neutrophils were found in pregnant compared to non-pregnant women. Additionally, specific subsets of pro-inflammatory monocytes (IL-6⁺CD14⁺ or MIP-1α⁺CD14⁺ cells) and neutrophils (IL-1β⁺CD15⁺ or MIP-1β⁺CD15⁺ cells) were increased in pregnant women in response to acute LPS stimulation. Moreover, distinct subsets of intermediate-activated monocytes expressing CD142, IL-6, and IL-1RA were increased in pregnant women upon chronic LPS stimulation. Last, pregnant women displayed a different cytokine profile than non-pregnant women in LPS-stimulated PBMCs and in whole blood. Conclusions Pregnancy tailors the immune responses of circulating monocytes and neutrophils to endotoxin, a Gram-negative bacterial product.

Objective and design The existing biological models of diffuse alveolar damage (DAD) in mice have many shortcomings. To offset these shortcomings, we have proposed a simple, nonsurgical, and reproducible method of unilateral total damage of the left lung in ICR mice. This model is based on the intrabronchial administration of a mixture of bacterial lipopolysaccharide (LPS) from the cell wall of S. enterica and α-galactosylceramide (inducing substances) to the left lung. Methods Using computer tomography of the lungs with endobronchial administration of contrast material, we have been able to perform an operative intravital verification of the targeted delivery of the inducer. The model presented is characterized by more serious and homogeneous damage of the affected lung compared to the existing models of focal pneumonia; at the same time, our model is characterized by longer animal survival since the right lung remains intact. Results The model is also characterized by diffuse alveolar damage of the left lung, animal survival of 100%, abrupt increases in plasma levels of TNFa, INFg, and IL-6, and significant myocardial overload in the right heart. It can be used to assess the efficacy of innovative drugs for the treatment of DAD and ARDS as the clinical manifestations that are developed in patients infected with SARS-CoV-2. Morphological patterns of lungs in the noninfectious (“sterile”) model of DAD induced by LPS simultaneously with α-galactosylceramide (presented here) and in the infectious model of DAD induced by SARS-CoV-2 have been compared. Conclusion The DAD model we have proposed can be widely used for studying the efficacy of candidate molecules for the treatment of infectious respiratory diseases, such as viral pneumonias of different etiology, including SARS-CoV-2.

Background A20 is an anti-inflammatory molecule in nucleus pulposus (NP) cells. The anti-inflammatory properties of A20 are mainly attributed to its ability to suppress the NF-κB pathway. However, A20 can protect cells from death independently of NF-κB regulation. This study aimed to investigate the effects of A20 on pyroptosis and apoptosis of NP cells induced by lipopolysaccharide (LPS). Methods NP cells induced by LPS were used as an in vitro model of the inflammatory environment of the intervertebral disc. Pyroptosis, apoptosis, and mitophagy marker proteins were detected. Then, NP cells were transfected with A20 overexpressed lentivirus or A20-siRNA. Annexin V FITC/PI, Western blotting, and immunofluorescence assays were used to detect the apoptosis, pyroptosis, and mitophagy of NP cells. Furthermore, the expressions of A20, related proteins, and related inflammatory cytokines were detected by western blotting, and ELISA. Results Apoptosis and pyroptosis of NP cells increased gradually treated with LPS for 12 h, 24 h, and 48 h. Differently, the level of mitophagy increased first and then decreased, and was the highest at LPS treatment for 12 h. Overexpression or knockdown of A20 in NP cells revealed that A20 attenuated the pyroptosis, apoptosis, and production of inflammatory cytokines of NP cells induced by LPS, while A20 sponsored mitophagy, reduced ROS production and collapse of mitochondrial membrane potential (ΔΨm). Moreover, A20 also promoted mitochondrial dynamic homeostasis and attenuated LPS-induced excessive mitochondrial fission. Excitingly, inhibition of mitophagy attenuated the effect of A20 on the negative regulation of pyroptosis of NP cells induced by LPS. Pyroptosis was accompanied by a large release of inflammatory cytokines. Inhibition of pyroptosis also significantly reduced apoptosis of NP cells. Finally, The mitochondria-targeted active peptide SS-31 inhibited LPS-induced pyroptosis and ROS production in NP cells. Conclusions To sum up, A20 attenuates pyroptosis and apoptosis of NP cells via promoting mitophagy and stabilizing mitochondrial dynamics. Besides, A20 reduces LPS-induced NP cell apoptosis by inhibiting NLRP3 inflammasome-mediated pyroptosis. It provides theoretical support for the reduction of functional NP cell loss in the intervertebral disc through the gene-targeted intervention of A20.

Objective Retinal ganglion cell (RGC) apoptosis is one of the most severe complications that causes permanent visual impairment following ocular alkali burn (OAB). Currently, very few treatment options exist for this condition. This study was conducted to determine the effect of 4-phenylbutyric acid (4-PBA) on endoplasmic reticulum (ER) stress after OAB using a well-established OAB mouse model. Methods Ocular alkali burn was induced in C57BL/6 mouse corneas using 1 M NaOH. 4-PBA (10 mg/kg; 250 μL per injection) or saline (250 μL per injection) was injected intraperitoneally once per day for 3 days before the establishment of the OAB model. The apoptosis of retinal ganglion cells (RGCs) was assessed by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay, and the histological damage was examined by hematoxylin and eosin and immunofluorescence assay on retinal flat mounts. The key inflammatory response and the expression of ER stress-related markers in the retinal tissues were assessed by real-time PCR, western blotting and histologic analyses. Results 4-PBA significantly alleviated the apoptosis of RGCs and prevented the structural damage of the retina, as determined by the evaluation of RGC density and retinal thickness. Inhibition of ER stress by 4-PBA decreased the expression of vital proinflammatory cytokines, tumor necrosis factor alpha, and interleukin-1 beta; and suppressed the activation of retinal microglial cells and nuclear factor-kappa B (NF-κB). 4-PBA reduced the expression of the ER stress molecules, glucose-regulated protein 78, activated transcription factor 6, inositol-requiring enzyme-1 (IRE1), X-box-binding protein 1 splicing, and CCAAT/enhancer-binding protein homologous protein, in the retinal tissues and RGCs of OAB mice. Conclusions The present study demonstrated that the inhibition of ER stress by 4-PBA alleviates the inflammatory response via the IRE1/NF-κB signaling pathway and protects the retina and RGCs from injury in an OAB mouse model. Such findings further suggest that 4-PBA might have potential therapeutic implications for OAB treatment.

Objective Inflammatory infiltration in aortic valves promotes calcific aortic valve disease (CAVD) progression. While soluble extracellular matrix (ECM) proteins induce inflammatory responses in aortic valve interstitial cells (AVICs), the impact of monocytes on AVIC inflammatory responses is unknown. We tested the hypothesis that monocytes enhance AVIC inflammatory responses to soluble ECM protein in this study. Methods Human AVICs isolated from normal aortic valves were cocultured with monocytes and stimulated with soluble ECM protein (matrilin-2). ICAM-1 and IL-6 productions were assessed. YAP and NF-κB phosphorylation were analyzed. Recombinant CD18, neutralizing antibodies against β2-integrin or ICAM-1, and inhibitor of YAP or NF-κB were applied. Results AVIC expression of ICAM-1 and IL-6 was markedly enhanced by the presence of monocytes, although matrilin-2 did not affect monocyte production of ICAM-1 or IL-6. Matrilin-2 up-regulated the expression of monocyte β2-integrin and AVIC ICAM-1, leading to monocyte-AVIC adhesion. Neutralizing β2-integrin or ICAM-1 in coculture suppressed monocyte adhesion to AVICs and the expression of ICAM-1 and IL-6. Recombinant CD18 enhanced the matrilin-2-induced ICAM-1 and IL-6 expression in AVIC monoculture. Further, stimulation of coculture with matrilin-2 induced greater YAP and NF-κB phosphorylation. Inhibiting either YAP or NF-κB markedly suppressed the inflammatory response to matrilin-2 in coculture. Conclusion Monocyte β2-integrin interacts with AVIC ICAM-1 to augment AVIC inflammatory responses to soluble matrilin-2 through enhancing the activation of YAP and NF-κB signaling pathways. Infiltrated monocytes may promote valvular inflammation through cell–cell interaction with AVICs to enhance their sensitivity to damage-associated molecular patterns.

The vaccination rate worldwide has reached enormous proportions, and it is likely that at least 75% of the world's population will be vaccinated. The controversy is that, while people aged 65 and older suffer a significantly higher mortality rate from COVID-19, plans are being made to vaccinate young people under the age of 20. Equally thorny is the question of vaccinating people who already have antibodies to SARS-CoV-2, as well as B and T memory cells, because they contracted and survived the virus. The possible consequences of large-scale vaccination are difficult to predict, when some people do not have access to the vaccine at all and others have already received 3 doses of the vaccine. SARS-CoV-2 will circulate through the human population forever and continue to mutate, as viruses do. Therefore, in the coming years, the need to develop and use effective vaccines and medicines for the prevention and treatment of COVID-19 will remain urgent in view of the high mortality rate from this disease. To date, three vaccine platforms have been most used: adenoviral vector, inactivated, and mRNA. There is some concern about the side effects that occur after vaccination. Whether modern anti-coronavirus vaccines can raise the safety threshold, only time will answer. It is obvious that the pandemic will end, but the virus will remain in the human population, leaving behind invaluable experience and tens of millions of victims. This article is based on search retrieves in research articles devoted to COVID-19 mainly published in 2020–2021 and examines the possible consequences of the worldwide vaccination against SARS-CoV-2 and suggests that, while anti-coronavirus vaccines will not magically transport humanity to a non-pandemic world, they may greatly reduce the number of victims of the pandemic and help us learn how to live with COVID-19.

Introduction and objective: Cervical cancer is the fourth most prevalent type of cancer in the world. The tumor microenvironment of this disease is associated with the production of several cytokines, pro and anti-infammatory, and with the purinergic signaling system so that changes in these components are observed throughout the pathological process. The aim of this review is to understand the pathophysiology of cervical cancer based on immunological processes and purinergic signaling pathways, in addition to suggesting possibilities of therapeutic targets. Materials and methods: To make up this review, studies covering topics of cervical cancer, infammation and purinergic system were selected from the Pubmed. Results: The main pro-infammatory cytokines involved are IL-17, IL-1β, IL-6, and IL-18, and among the anti-infammatory ones, IL-10 and TGF-β stand out. As new therapeutic targets, P2X7 and A2A receptors have been suggested, since blocking P2X7 would lead to reduced release of pro-infammatory cytokines, and blocking A2A would increase activation of cytotoxic T lymphocytes in the context of tumor combat. The association between the immune system and the purinergic system, already known in other types of disease, also presents possibilities for a better understanding of biomolecular processes and therapeutic possibilities in the context of cervical cancer.