Helgi B Schiöth’s research while affiliated with Uppsala University and other places

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Publications (808)


Corrigendum: Synthesis, characterization, and computational evaluation of some synthesized xanthone derivatives: focus on kinase target network and biomedical properties
  • Article
  • Full-text available

April 2025

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12 Reads

Wisam Taher Muslim

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Helgi B. Schiöth
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GPCR drug discovery: new agents, targets and indications

March 2025

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59 Reads

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5 Citations

Nature Reviews Drug Discovery

G protein-coupled receptors (GPCRs) form one of the largest drug target families, reflecting their involvement in numerous pathophysiological processes. In this Review, we analyse drug discovery trends for the GPCR superfamily, covering compounds, targets and indications that have reached regulatory approval or that are being investigated in clinical trials. We find that there are 516 approved drugs targeting GPCRs, making up 36% of all approved drugs. These drugs act on 121 GPCR targets, one-third of all non-sensory GPCRs. Furthermore, 337 agents targeting 133 GPCRs, including 30 novel targets, are being investigated in clinical trials. Notably, 165 of these agents are approved drugs being tested for additional indications and novel agents are increasingly allosteric modulators and biologics. Remarkably, diabetes and obesity drugs targeting GPCRs had sales of nearly US $30 billion in 2023 and the numbers of clinical trials for GPCR modulators in the metabolic diseases, oncology and immunology areas are increasing strongly. Finally, we highlight the potential of untapped target-disease associations and pathway-biased signalling. Overall, this Review provides an up-to-date reference for the drugged and potentially druggable GPCRome to inform future GPCR drug discovery and development.


FIGURE 2 Flow diagram showing the literature search on cryoprotective agents used in carnivorous semen cryopreservation/vitrification.
FIGURE 3 (Continued)
FIGURE 4
FIGURE 6
Thermodynamic properties of cryoprotectants used in carnivorous semen cryopreservation based on Chemeo, high-quality chemical properties (www.chemeo.com), and Joback method predicted at 813.3 ° K.

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Comprehensive overview of the toxicities of small-molecule cryoprotectants for carnivorous spermatozoa: foundation for computational cryobiotechnology

Frontiers in Toxicology

Background The specific and non-specific toxicities of cryoprotective agents (CPAs) for semen or spermatozoa cryopreservation/vitrification (SC/SV) remain challenges to the success of assisted reproductive technologies. Objective We searched for and integrated the physicochemical and toxicological characteristics of small-molecule CPAs as well as curated the information of all extenders reported for carnivores to provide a foundation for new research avenues and computational cryobiology. Methods The PubMed database was systematically searched for CPAs reported in SC/SV of carnivores from 1964 to 2024. The physicochemical features, ADMET parameters, toxicity classes, optimized structures, biological activities, thermodynamic equilibrium constants, and kinetic parameters were curated and assessed computationally. Results Sixty-two relevant papers pertaining to CPAs used in SC/SV were found, and 11 CPAs were selected. Among the properties of CPAs, the molecular weight range (59–758 g/mol), melting point (−60°C to 236°C), XlogP3 (−4.5 to 12.9), topological polar surface area (TPSA; 20–160 Å ² ), Caco2 permeability (−0.62 to 1.55 log(P app ) in 10 –6 cm/s), volume of distribution (−1.04 to 0.19 log L/kg), unbound fraction of a CPA in plasma (0.198–0.895), and Tetrahymena pyriformis toxicity (log µg/L; −2.230 to 0.285) are reported here. Glutathione, dimethyl formamide, methyl formamide, and dimethyl sulfoxide were used as the P-glycoprotein substrates. Ethylene glycol, dimethyl sulfoxide, dimethyl formamide, methyl formamide, glycerol, and soybean lecithin showed Caco2 permeabilities in this order, whereas fructose, glutathione, glutamine, glucose, and citric acid were not Caco2-permeable. The CPAs were distributed in various compartments and could alter the physiological properties of both seminal plasma and spermatozoa. Low volume distributions of all CPAs except glucose indicate high water solubility or high protein binding because higher amounts of the CPAs remain in the seminal plasma. Conclusion ADMET information of the CPAs and extenders in the bipartite compartments of seminal plasma and intracellular spaces of spermatozoa are very important for systematic definition and integration because the nature of the extenders and seminal plasma could alter the physiology of cryopreserved spermatozoa.



Targeting platinum-resistant ovarian cancer by disrupting histone and RAD51 lactylation

February 2025

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5 Reads

Theranostics

Rationale: Ovarian cancer is a highly lethal gynecological malignancy with common platinum resistance. Lactylation is involved in multiple biological processes. Thus, we explored the role of histone and non-histone lactylation in platinum resistance, providing a potential therapeutic target to overcome platinum resistance in ovarian cancer. Methods: We utilized gene set enrichment analysis to investigate lactylation-related pathway alterations between platinum-resistant and platinum-sensitive patients from the TCGA cohort. Differential expression of H3K9la was demonstrated using Western blotting and immunohistochemistry. Progression-free and overall survival were determined using a log-rank test. Drug response to cisplatin was evaluated by CCK8, apoptosis flow cytometry, and clonogenic assays in vitro. ChIP-seq and ChIP-qPCR assays were performed to identify downstream targets of H3K9la, which was further confirmed by qRT-PCR. LC-MS/MS was conducted to identify specific lactylation sites for RAD51. Co-IP was used to reveal the interaction between GCN5 and H3K9la or RAD51la. Cell line-derived and patient-derived xenograft (PDX) models of ovarian cancer were constructed for the in vivo experiments. Results: Our study showed elevated histone lactylation, especially of H3K9la, in platinum-resistant ovarian cancer. Moreover, high H3K9la indicated platinum resistance and poor prognosis of ovarian cancer. Impairing H3K9la enhanced response to cisplatin. Mechanistically, H3K9la directly activated RAD51 and BRCA2 expression to facilitate homologous recombination (HR) repair. Furthermore, RAD51K73la enhanced HR repair and subsequently conferred cisplatin resistance. H3K9la and RAD51K73la shared the same upstream regulator, GCN5. Notably, a GCN5 inhibitor remarkably improved the tumor-killing ability of cisplatin in PDX models of ovarian cancer. Conclusions: Our study demonstrated the essential role of histone and RAD51 lactylation in HR repair and platinum resistance. It also identified a potential therapeutic strategy to overcome platinum resistance and improve prognosis in ovarian cancer.


Inulin as a Biopolymer; Chemical Structure, Anticancer Effects, Nutraceutical Potential and Industrial Applications: A Comprehensive Review

Inulin is a versatile biopolymer that is non-digestible in the upper alimentary tract and acts as a bifidogenic prebiotic which selectively promotes gut health and modulates gut–organ axes through short-chain fatty acids and possibly yet-to-be-known interactions. Inulin usage as a fiber ingredient in food has been approved by the FDA since June 2018 and it is predicted that the universal inulin market demand will skyrocket in the near future because of its novel applications in health and diseases. This comprehensive review outlines the known applications of inulin in various disciplines ranging from medicine to industry, covering its benefits in gut health and diseases, metabolism, drug delivery, therapeutic pharmacology, nutrition, and the prebiotics industry. Furthermore, this review acknowledges the attention of researchers to knowledge gaps regarding the usages of inulin as a key modulator in the gut–organ axes.


Establishment and verification of a prognostic signature associated with fatty acid metabolism in endometrial cancer

January 2025

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4 Reads

Molecular Medicine Reports

Endometrial carcinoma (EC) is one of the leading causes of mortality in women. Metabolic disorders, such as abnormal fatty acid metabolism (FAM), are considered to be indicators of tumorigenesis. However, to the best of our knowledge, the relationship between EC and FAM remains unclear. The process of FAM is associated with the function of immune cells, thus samples from The Cancer Genome Atlas were grouped according to immune infiltration levels. Subsequently, prognostic gene signatures were constructed based on selected FAM-associated genes. The signature effect was validated, and enrichment analyses were conducted based on sample classification. Nomograms were used to predict survival, merging clinical data and the gene signature. Samples were divided into high- and low-risk groups based on the gene signature. The survival status, clinical characteristics, enrichment analysis and immune infiltration were significantly different between high- and low-risk groups. According to the nomogram, low microsatellite instability-high as well as a high tumor mutation burden can be observed in the low-nomo-score group. Immune checkpoint inhibitor-associated genes were differentially expressed between groups and 35 sensitive compounds were identified. Comprehensive bioinformatics analysis in EC revealed potential roles of FAM in tumorigenesis, the tumor microenvironment and prognosis, suggesting that FAM-associated signatures are promising biomarkers for EC. These findings may improve the understanding of FAM in EC and pave the way for a more accurate assessment of prognosis and immunotherapy outcomes.


Figure 1: β-cell regulation of electrical activity and insulin secretion
β-cell function, Ca2+ management, and insulin secretion are regulated by the coordinated interaction of ionic movements. (0) In the absence of glucose, KATP channel is open, maintaining the β-cell membrane hyperpolarized and electrically silent. (1) Glucose influx initiates electrical activity through increase in metabolically produced ATP, (2) which binds to KATP and gradually reduces its conductance, causing an increase in the β-cell membrane potential. (3) β-cell is slowly depolarized in waves, activating voltage-gated calcium (VGCC) and sodium (VGSC) channels and eliciting exocytosis of insulin. (4) Continued depolarization subsequently activates voltage-gated potassium channels (KV). (5) K+ efflux initiates and regulates the repolarization and consequent hyperpolarization of the cell membrane action potential. ATP dependent Na+/K+-ATPase (NKAs) activate by multiple metabolic factors, including insulin receptors and once activated (6) further hyperpolarize β-cell membrane, temporarily halting β-cell electrical excitability, closing KV and inhibiting influx of Na+ and Ca2+ entry, thereby reducing insulin secretion. (7) Gi/o-GPCR ligands signalling also activates NKAs and (8) hyperpolarizes β-cell membrane halting Ca2+ influx and insulin secretion. Reduction in ATP during hyperpolarization allows a new increase β-cell membrane potential, leading to another wave of depolarization and insulin secretion. (9) The glucose induced insulin release (GSIS) is potentiated by GS-GPCR stimulation with GLP-1, GIP and other GS-ligands that activate adenylyl cyclase (A.C.) thereby elevating levels of intracellular cAMP. cAMP drives changes including Ca2+ influx, mobilization, and the enhanced fusion competence of secretory granules. (10) Elevation of intracellular cAMP concentrations and the activation of cAMP-dependent protein kinase A (PKA) leads to opening of IP3 receptors in ER, releasing Ca2+ from internal stores, notably the ER, thereby potentiating GSIS and promoting insulin exocytosis even in Ca2+ depleted conditions. (11) PKA activity in β-cell will also inhibit NKA function and promote β-cell depolarization. (12) Independently of PKA, cAMP also activates Epac2-mediated engagement of Rap1 in β-cells that increase the size of the non-docked granule pool and facilitate recruitment and density of the granules to the plasma membrane, thereby potentiating insulin secretion even at low concentrations of glucose. (13) Depolarization independent from glucose influx can occur when β-cell is exposed to GABA, through GABAA receptor (GABAAR) opening allowing for Cl- efflux. GABA is synthesized in β-cells from glutamate with GAD65 enzyme and can activate GABA receptors on the β-cell in positive feedback loop. GAD65 is distributed between ER/Golgi membrane-anchored, vesicular, and cytosolic localizations. While a minority of β-cells display vesicular GABA colocalization with insulin, most β-cells release GABA via volume regulatory anion channels (VRAC) in a pulsatile pattern, occurring in rhythmic bursts independent of glucose concentration. (14) Insulin expression in β-cells is achieved by a glucose-dependent transcriptional program. Three transcriptional regulators, PDX1, NeuroD1 and MafA are responsible in glucose induced of insulin gene transcription and β-cell-specific function. (15) Insulin gene encodes mRNA pre-proinsulin, which is translated and translocated across the ER membrane where the signal peptide is removed. The resulting proinsulin molecules are subsequently folded and transported to the Golgi apparatus via the ER-Golgi interface compartment. (16) Upon exposure to acidity and high Ca2+ within the Golgi apparatus, the soluble cargo precursor proteins aggregate and bind Ca2+, which triggers aggregation of proinsulin molecules in the trans-Golgi network (TGN). Insulin secretory granule (SG) cargo, including proinsulin, is packaged into granules that bud off from the TGN. (17) SG mature by acidification through the action of the vesicular ATP-dependent proton pump (V-ATPase). Proton (H+) transport over the granular membrane results in the development of a considerable membrane potential (ΔΨ) and pH changes. Uptake of negatively charged glutamate (Glu-) by VGLUT3 sets up a counter-charge movement which decreases the granular membrane polarization allowing sustained H+ transport by the V-ATPase. EAAT2 in the SG provides a mechanism for the release of accumulated Glu-, 3Na+ and an H+ exchanged with 1K+, which decreases the granular membrane polarization allowing sustained acidification by the V-ATPase. Cl− fluxes through CLC3 channel in SG membrane provide additional counter conductance for continuous granular acidification. Acidification lowers the pH in the granule and activates prohormone-processing enzymes PC1/3, PC2 and CPE that convert proinsulin to active insulin inside the SG. (18) Insulin exocytosis occurs through a process involving SG docking to the plasma membrane, followed by priming and inward Ca2+ and Na+ flux dependent release.
Figure 2: Proposed chart of T1D dual vulnerability initiated by β-cell metabolic dysfunction and CD4+ T-cell activation. 
1.	β-cell metabolic dysfunction processes (orange numbers)
(1) Chronic exposure to hyperglycemia causes elevation of the carbohydrate response-element binding protein β (ChREBPβ) and Ca2+ influx, leading to increased transcription of pro-apoptotic TxNIP.
(2) In the β-cell TxNIP upregulates transcription of NLRP3 inflammasome, a protein complex responsible for caspase-1–dependent maturation of the proinflammatory cytokines IL-1β and IL-18 and gasdermin D(GSDMD)-mediated apoptotic cell death.
(3) The onset of metabolic dysfunction may also arise from the impaired glutamate transmission and dysregulation of the β-cell’s N-methyl-d-aspartate receptors (NMDARs), which play a crucial role in controlling insulin secretion, electrical activity, and cell survival by modulating the influx of calcium ions (Ca2+) and sodium ions (Na+). Increases in cytosolic Ca2+ levels cause increased permeability of mitochondria, altered mitochondrial respiration, release of reactive oxygen species (ROS) and activation of other pro-apoptotic factors. Breakdown of the depolarization mechanisms precludes repolarization via opening of voltage-gated K+ channels (KV), which can have an excitotoxic effect on β-cells and increase intracellular Ca2+ levels. 
(4) β-cell metabolic dysfunction could suppress GABA synthesis from intracellular glutamate by glutamic acid decarboxylase (GAD65) and release of GABA from β-cells. GAD65 is one of the major target antigens in T1D, and GAD65 autoantibody is a diagnostic marker for T1D. Patients with T1D exhibit a significant reduction in plasma GABA levels. This impacts islet regulatory pathways, including a key β-cell mechanism for glucagon regulation in the α-cells via chloride (Cl-) influx through GABAAR and hyperpolarization of the α-cell plasma membrane. Insufficient extracellular GABA levels also hinders cAMP-dependent β-cell survival pathways, such β-catenin-mediated (β-cat) signalling and GABAB receptor (GABABR) initiated PI3K-AKT-cascades. Additionally, reduced GABA signalling will also fail to inhibit T cell proliferation through activating GABAA Cl- channels and reducing secretion of IFN-γ, IL-6, IL-12, IL-1β and TNF-α.
(5) Cellular stress includes endoplasmic reticulum (ER) stress which triggers an unfolded protein response (UPR) consisting of impaired RNA transcription and translation, leading to depletion of ER Ca2+ stores and accumulation and release of misfolded proteins, hybrid insulin peptides (HIP) and increased autoantigen presentation. 
(6) Elevated serum DPP-4 (sDPP-4) levels are found to be elevated in T1D patients and degrade incretins such as GLP-1, thereby preventing incretin-induced cAMP downstream signalling in β-cells, which interferes with glucose-stimulated insulin secretion (GSIS) and impairs cAMP-dependent cell survival processes. 
(7) An inflammatory trigger event in β-cells (e.g. viral infection via coxsackie and adenovirus receptor (CAR)) would initiate secretion of type I interferons (IFN-α/β) by immune system or other cells, leading to activation of the JAK-STAT pathway and the NF-κB pathway and increase of ER stress in the β-cell.
(8) IFN-α has been identified as a key driver of increased expression of HLA class I molecules of the major histocompatibility complex I (MHC1) system on β-cells in the early stages of T1D. These MHC1 molecules bind β-cell-derived autoantigens (β-Ag) and activate CD8+ T-cells, as well as upregulate ER stress sensors and markers in the β-cell (e.g. p-EIF2α, XBP1s, BIP, C/EBP homologous protein (CHOP), ATF3 and ATF6). 
(9) The T1D-associated gene TYK2 contributes to the activation of IFN-α-mediated MHC1 expression in β-cells. 
(10) HLA-DR3/4 and HLA-DQ2/8 haplotypes of the HLA class II molecules of the MHC2 system are those associated with T1D.
(11) Expression of MHC2 molecules by islet β-cells is an aberrant feature that confers β-cells the ability to bind β-Ag associated with T1D and engage CD4+ T cells in an antigen-presenting cell (APC)-like manner, initiating autoimmunity.
2. Autoimmune processes (yellow numbers).
Immune cell responses against antigens and β-cell derived β-Ag play a central role in the pathogenesis of T1D. 
(1) Independently of MHC1 and MHC2 β-Ag presentation, β-cells under metabolic stress continuously secrete fused peptide fragments or hybrid insulin peptides (HIPs) that are recognised by APCs as autoantigen targets for pathogenic islet-infiltrating T-cells. 
(2) Some β-Ag are processed by APCs and presented to naïve CD4+ T-cells as antigens by MHC2 molecules on the surface of the APC. 
(3) CD4+ T-cell activation and differentiation depends on the signal strength received by the T-cell receptor (TCR) via the binding of MHC2 and on co-stimulation signals. CD28 and membrane-bound DPP4 (mDPP4) are prominent co-stimulatory molecules controlling the activation and behaviour of naïve CD4+ T-cells. The mDPP4-mediated signal can be co-stimulated with APC in a caveolin-1-mDPP4-CD45-CD3-dependent manner activating the MAPK/ERK signalling pathway, or by the adenosine deaminase (ADA)-mDPP4 pathway activating pro-inflammatory NF-κB transcription factors.
(4) CD4+ T-cells depend on the membrane action potential that is initiated by TCR stimulation for activation, intracellular Ca2+ homeostasis, cytokine production, and proliferation. Autoantigen-activated MHC2-TCR complex depolarizes the T-cell membrane and opens KV1.3 channels that are a part of a signalling complex with P56lck (LCK), previously associated with impaired T-cell activation in T1D. K+ efflux opens Ca2+ release-activated channels (CRAC), resulting in significant Ca2+ influx and opening of KCA3.1 channels, thereby sustaining prolonged Ca2+ entry that is needed for further T-cell activation, cytokine release and proliferation. 
(5) Upon TCR-activation and metabolic reprogramming, CD4+ T-cells also upregulate the expression of NMDAR, which are glutamate-activated and have an effect on cytokine production, T-cell proliferation, and differentiation. 
(6) In APCs, mDPP4-caveolin-1 interaction up-regulates the expression of CD86 and subsequent engagement and recruitment of CD8+ cytotoxic T-cells, and cytokine secretion. The production by the APCs of cytokines such as IL-12 and IFN-γ promotes and accelerates further differentiation of the CD4+ T-cells into Th1-type cells and inhibits CD4+ Th2 cell production of IL-4 and IL-10. Additionally, IFN-γ upregulates expression of NADPH oxidase/NOX family proteins that transport electrons from nicotinamide adenine dinucleotide and generate cytoplasmic reactive oxygen species (ROS).
(7) Metabolic reprogramming of naïve CD4+ T cells also leads to an increase in ROS and accelerated proliferation and activation of specialized immune cell subtypes, such as Th1, Th7, and Tfh. Activated CD4+ and CD8+ T cells also secrete IFN-γ, IL-12, IL-18 and pro-inflammatory TNF-α and IL-1β, activating macrophages and stimulating the production of reactive nitrogen intermediates (RNIs). 
(8) Binding of CD8+ T-cells with β-cells, via a T-cell receptor (TCR)-MHC1 complex induces β-cell death through secretion of toxic molecules, such as perforin and granzymes. T-cells and macrophages can also destroy β-cells by secreting nitric oxide (NO°) and cytotoxic cytokines, subsequently activating a NF-κB signalling profile. Importantly, secretion of these cytokines by CD4+ T-cells may also increase expression of MHC1 on β-cells and promote direct assaults by CD8+ T-cells. 
(9) Autoimmune assaults on the β-cells by ROS, RNIs, actions of cytokines, and granzymes that activate caspase enzymes, leads to β-cell apoptosis and/or necrosis.
Figure 3 Legend: Therapeutic interventions in immune cells
Immune cells
(1) Anti-thymocyte globulin (ATG) induces broad non-specific immunosuppression that is primarily mediated through the recognition of a series of antigens expressed on human lymphohematopoietic cells, such as CD2, CD3, CD4, and CD8 expressed on T cells, CD19 and CD20 expressed on B cells, and CD11b, CD80 and CD86 expressed on antigen presenting cells (APCs). ATG achieves immunosuppression by eliminating lymphocytes in the recirculating pool through complement-mediated intravascular lysis, apoptosis and antigen-dependent cell-mediated cytotoxicity. Low-dose ATG reduced HbA1c 2 years after therapy in recent-onset T1D patients. 
(2) Anti-CD3 monoclonal antibody (teplizumab) blockade of CD3 receptors in T cells induces a state of anergy in certain T cell populations, making them unresponsive to specific stimuli, and promoting regulatory T cell functions. In recent-onset T1D patients, teplizumab was observed to preserve β-cell function and slow-down C-peptide degradation.
Co-stimulatory signal blockade in T cells
(3) Abatacept is a CTLA-4/Fc fusion protein that prevents T cell CD28 interaction with its CD80/86 ligand on APCs and thereby limiting immune system activation. Abatacept modified progression of T1D by significantly impacting CD4+ cell subsets, thereby delaying the decline of C-peptide and improving HbA1c in recent-onset T1D patients.
(4) Alefacept is an anti-CD2 fusion protein that has a dual function, as it triggers programmed cell death of activated memory T cells and inhibits the interaction between leukocyte-function-associated antigen (LFA-3) and CD2, effectively preventing co-stimulatory signaling for the activation and proliferation of T cells. In recent-onset T1D patients two 12-week courses of alefacept delayed C-peptide decline and depleted CD4+, CD8+ T cells and effector memory T cells for over a year after cessation of therapy.
(5) High expression of membrane-bound dipeptidyl peptidase-4 (mDPP-4) is associated with the differentiation of T lymphocytes into Th1 (IL-2, IFN-γ) and Th17 (IL-6, IL-17, and IL-22) cells and upon activation of B cells. DPP-4 inhibitors (DPP-4i) disrupt the mDPP4-caveolin-1 nuclear factor kappa B (NFκB) activation pathway, which leads to a decrease in the expression of CD86 on antigen-presenting cells (APCs) and other monocytes. This limits the interaction between CD86 and CD28 on T cells, resulting in a reduction in the proliferation and activation of antigen-specific T cells. Additionally, DPP-4 inhibition prevents binding of mDPP-4 with adenosine deaminase (ADA) that would otherwise lead to the formation of a co-stimulatory CD3 signaling complex in CD4+ T cells initiating CARMA-1 signaling. Furthermore, DPP-4 inhibitors prevent activation of Th1 cells, thereby leading to decreased secretion of proinflammatory cytokines: IL-1β, IFNγ, TNFα and IL-2 from Th1 cells.
GLP-1
(6) Activated T cells express higher number of functional glucagon-like peptide-1 receptors (GLP-1R) in human CD4+ T cells and GLP-1R activation by GLP-1 receptor agonists (GLP-1RA) in Treg cells leads to increased IL-10 expression and enhanced cellular inhibitory function.
T regulatory cells (Treg cells)
(7) DPP-4 inhibition in CD4+ T cells is found to promote the function of Treg cells and production of the immunosuppressive cytokine TGF-β. Immuno-suppressive functions of Treg cells are facilitated through CTLA-4 ligand binding to CD80/86 on APCs, expression of immunosuppressive cytokines: IL-10, TGF-beta and CD39-induced hydrolyzation of ATP to adenosine (ADO). Treg-derived ADO is a hydrolysis product of extracellular ATP cleaved in tandem by two Treg-associated ectonucleotidases, CD39 and CD73. 
(8) Most naïve CD8+ T cells and a small number of mature CD4+ and Treg cells express CD73 on their surface. Enzyme-active CD73 is released from the CD8+ T cell membrane upon activation, allowing Treg cell-driven ATP hydrolysis to occur, leading to adenosine formation. In immune cells, adenosine binds to the A2A receptor (A2aR), leading to the elevation of cAMP and interfering with functions of activated T cells and APCs, inhibiting their proliferation and cytokine production.
IL-21
(9) IL-21 is produced primarily by CD4+ T cells and is required for both Th17 cell differentiation and the generation of T follicular helper (Tfh) cells. IL-21 is the most prominent cytokine for the activation and differentiation of human B cells. IL-21 induces differentiation of human naive and memory B cells into antibody-secreting plasma cells. Other cytokines, such as IL-4, greatly inhibit IL-21-driven plasma cell differentiation. IL-21 also directly regulates B cell proliferation and apoptosis and can promote immunoglobulin production and isotype class switching. In addition, IL-21 signaling enhances the cytotoxicity of CD8+ T cells and natural killer (NK) cells. A combination treatment of anti-IL-21 and GLP-1RA (liraglutide) preserved β-cell function in recent-onset T1D patients. This was demonstrated by a reduction in the concentration of C-peptide, as measured during a mixed-meal tolerance test (MMTT), from the baseline measurement to week 54 of treatment.
B cells
(10) Anti-CD20 mAb (rituximab) effectively depletes mature B cells by various mechanisms inducing cell death, including DNA fragmentation, complement-dependent cytotoxicity (CDC) and programmed cell death (PCD). CD20 is reported to regulate B cell differentiation and growth as well as adjusting Ca2+ transport. Notably, CD20 is detectable on pre-B cells to mature B cells but is absent on antigen-producing plasma cells.
GABA
(11) Gamma-aminobutyric acid (GABA) has broad immune-modulating properties. It controls the release of cytokines from CD4+ T cells and anti-CD3-stimulated peripheral blood mononuclear cells (PBMCs). Importantly, GABA suppresses the release of 47 cytokines in PBMCs from T1D patients and regulates pro- and anti-inflammatory cytokine production in a concentration-dependent manner. Engagement of the GABAA receptor (GABAAR) induces depolarization of the membrane potential, leading to inhibition of T cell responses. B cells secrete GABA, which then inhibits inflammatory cytokine production in CD8+ T cells and stimulates monocyte differentiation into IL-10-secreting immuno-suppressive cells.
Calcium blockade 
(12) Lymphocyte calcium channel blockade may be an effective immunosuppressive strategy. Verapamil had a significant impact on T cell activation by strongly inhibiting the expression of CD25 (which is typically present in Tregs), CD40L, and CD69. This inhibition is likely due to the failure of Ca2+-dependent transcription factors to activate gene transcription. Nuclear factor of activated T cells (NFAT) is triggered by Ca2+, which also triggers the production of other transcription factors, including IRF4 and HIF-1α, that control the metabolic switch, cell cycle progression, and proliferation of activated human T cells. Verapamil partially preserves β-cell function, as shown by C-peptide secretion in children and adolescents with recent-onset T1D.
Proton pump inhibitors 
(13) In immune cells, proton pump inhibitors (PPIs) suppress T cell responses by decreasing the expression of the T cell receptor (TCR)-activated membrane zinc transporter Zip8, thereby lowering the cytoplasm-free zinc (Zn) concentration. PPI-induced decrease in Zip8 expression increases transcription factor CREMα, which dramatically downregulates IL-2 production, while decreases in the transcription factor pCREB downregulate production of IFN-γ in lymphocytes. In monocytes, PPIs were found to reduce production of several inflammatory cytokines: TNFα, IL-1β, IL-6 and NFκB. Moreover, PPIs inhibit the activation of neutrophils and monocytes, and deplete intracellular and extracellular neutrophil reactive oxygen species (ROS) and nitric oxide (NO). PPI with DPP-4i in recent-onset T1D patients did not achieve C-peptide preservation, but due to high safety PPI and DPP-4i have been suggested to be used in combination with other drugs. Preliminary results show that a combination of GABA, DPP-4i and PPI as an adjunct to insulin therapy improves glycemic control in patients with T1D and elevates C-peptide levels in recent-onset T1D patients.
Beta-cells
Cytokine blockade
(A) During the progression of T1D macrophages and T cells invade the islets and secrete pro-inflammatory cytokines. The combination of TNF-α and IFN-γ synergistically induces β-cell apoptosis through activation of JNK/SAPK, resulting in the production of reactive oxidative species (ROS) and loss of mitochondrial transmembrane potential (ΔΨm). Proinflammatory cytokine blockade may act to prevent deleterious effects on β-cell survival and function in the islet microenvironment. Anti-inflammation and cytokine-modifying therapies showed varying degrees of effectiveness as TNF-α monoclonal antibodies (e.g. Golimumab and Etanercept) postponed C-peptide loss in patients with recent-onset T1D. Canakinumab binds human IL-1β with high affinity and neutralizes its biological activity while Anakinra is an IL-1 receptor antagonist. Due to high safety, but insufficient efficacy in recent-onset T1D patients, canakinumab and anakinra have been suggested for IL-1β blockade as part of combination therapies. 
Verapamil + IGF-1
(B) Verapamil downregulates Ca2+ influx and thereby disrupts formation of thioredoxin-interacting protein (TXNIP), reduces β-cell expression of IGF-binding protein 3 (IGFBP3) and thereby elevates IGF-1 induced signalling via increased IGF-1. 
(C) Stimulation of IGF-1R initiates PI3K/Akt signaling, which enables the activation of mTORC1. Upon activation mTORC1 phosphorylates the 4EBP1 protein, promoting cell growth, and the p70 ribosomal protein S6 kinase (S6K1), resulting in enhanced ribosomal biogenesis, mitochondrial biogenesis, and oxygen consumption. PI3K/Akt signaling also promotes β-cell-, but inhibits α-cell-related gene expression, as well as inhibiting β-cell apoptosis in the context of inflammatory cytokines and oxidative stress. Importantly, insulin receptor (IR) and IGF-1R are highly homologous and share PI3K/ Akt and Ras/ MAPK signaling pathways IR largely controls metabolism, whereas IGF-1R controls growth.
(D) IGFBP-3 is a negative regulator of β-cell mass independently of IGF-1, which is a positive regulator. IGFBP-3 is a binding ligand to the death receptor TMEM219, which is widely expressed in islet β-cells.  Bound TMEM219 triggers Caspase-8-mediated apoptosis of β-cells.
(E) A 26-week course of a small tyrosine kinase inhibitor, imatinib mesylate (Gleevec, STI571) preserved β-cell function at 12 months in adults with recent-onset T1D. Imatinib acts as a β-cell protective drug, as it reduces ER stress and consequent β-cell apoptosis by inhibiting ABL kinase binding and hyperactivation of ER transmembrane kinase’s endoribonuclease (IRE1α RNase).
Figure 4 legend: Type 1 diabetes targets for pharmaceutical intervention in endocrine cells.
β-cell:
This figure illustrates the key targets for pharmaceutical intervention of oxidative stress, glucotoxicity and apoptosis in pancreatic β-cells. (1) Thioredoxin interacting protein (TxNIP) has an important role and the transcription is activated by carbohydrate-response element-binding protein (ChREBP) which binds to the TXNIP promotor and mediates glucose-induced TxNIP expression. During hyperglycaemia glucose is converted to Xu-5-P, with elevation of cytosolic Ca2+ ChREBP is translocated into nucleus and translated into TxNIP. (2) First generation Ca2+ blockers (diltiazem or verapamil) significantly reduce endogenous TXNIP mRNA expression due to reduction of cytosolic Ca2+. The nuclear-cytoplasmic shuttling of ChREBP and binding to DNA are regulated by PKA- and AMPK-mediated phosphorylations. Metformin transiently inhibits complex I of electron transport chain in the mitochondrion, leading to inhibition of V-ATPase and LKB1-mediated AMPK activation. Activated AMPK directly hinders ChREBP at Ser568, prevents cytosol-to-nuclear translocation and inactivates its DNA binding activity. (4) V-ATPase functions as sensor switch between AMPK induced catabolic metabolism and mTORC1 anabolic pathways. Activation of mTORC1 is a major to increase of beta-cell mass by modulation of cyclin D2, D3, and Cdk4 activity. (5) Some PPI can also inhibit V-ATPase-Ragulator and induce AMPK mediated response to ROS. Additionally, omeprazole preserves ALDH2 in mitochondria. Activation of ALDH2 in β-cells prevents apoptosis, enhances GSIS and reduces both the mitochondrial and intracellular ROS levels. (6) Pharmaceutical interventions with GLP-1RA, GCGR mAbs and DPP-4i induced GLP-1 elevation stimulate GS-coupled ligands and initiate cAMP-PKA and cAMP-Epac signalling, thereby downregulating TxNIP expression levels in hyperglycaemic conditions. (7) PKA phosphorylates ChREBP at Ser196, which inhibits nuclear import at Thr666, which inhibits DNA-binding activity. Downregulation of TxNIP expression reduces caspase-1 expression and prevents the caspase-induced apoptosis. (8) β-catenin (β-Cat) is another pharmaceutical target that can promote proliferation, survival and function of β-cells in diabetic conditions. GLP-1RA activation leads to β-Cat stabilization through PKA-mediated phosphorylation. (9) Additionally, Wnt-β-cat and PI3K-AKT-mTORC1 pathways share a common inhibition target GSK3β and independently can upregulate free cytosolic β-cat. (10) In the nucleus β-Cat forms the bipartite transcription factor β-cat/TCF with a TCF family member (e.g. TCF7L2) upregulating GLP-1R and GIPR expression and several proliferative genes, including c-myc and cyclin D1. (11) PPI indirectly elevate serum gastrin. (12) Stimulation of G-coupled receptors, including gastrin receptor CCK2R, GABABR, Gi/o-GPCR and Insulin Receptors activate PI3K-AKT pathway leading to activation of mTORC1 and inhibition/mediation of GSK3β, caspase-9 and Bcl-2-associated death promoter (Bad). (13) Expression of functional GABABR in human islets is restricted and tightly regulated by elevation in cAMP signalling. GABABR is primarily coupled to the Gi/o-GCGR and their activation leads to hyperpolarization induced closure of VGCC and insulin secretion. (14) NMDAR inhibition with dextromethorphan (DXM) significantly prolongs β-cell depolarization state promoting insulin secretion. (15) GCGR mAbs, such as IgG2 mAb volagidemab, bind to the human GCGR, competitively blocks GCGR interaction with glucagon, thereby reducing cAMP and elevating AMPK. GCGR antagonism can improve glycemic control but cause adverse events in patients. (16) In β-cells activation of GABAARs with GABA, benzodiazepines, barbiturates, neurosteroids, and ethanol lead to Cl− efflux and depolarization, opening of VGSC, VGCC and promoting insulin release. 
α-cell:
(1) Insulin inhibits glucagon secretion via insulin-dependent SGLT-2-induced stimulation of somatostatin release by δ cells, which downregulate cAMP, activate Gi/o-GPCR and hyperpolarize α-cell membrane. (2) Additionally, β-cells secretion of insulin and GABA inhibit glucagon secretion via IR activation of PI3K-AKT-dependent membrane assembly and activation of GABAAR activity. (3) GABAAR activation with GABA lead to Cl− influx, α-cell membrane hyperpolarization and suppression of glucagon secretion. (4) GABA and artemisinins can potentially reprogram α-cell into β-like-cell by repression or expression of key transcription factors.
δ-cell: 
Somatostatin is a paracrine inhibitor of both insulin and glucagon. (1) The δ-cells are electrically excitable and somatostatin secretion depends on SGLT2 activation by (2) insulin and KATP induced depolarization, provided there is extracellular Na+ and elevated glucose levels. (3) SGLT2 inhibitors were seen to improve clinical parameters in T1D patients but can provoke euglycemic ketoacidosis and increase hepatic glucose production.
Pancreatic exocrine cells
(1) Gastrin enhances ductal cell trans-differentiation into insulin producing β-like cells. In ductal cells, concurrent administration of gastrin with epidermal growth factor or GLP-1RA has been shown to increase the β-cell mass and/or to improve glucose tolerance. (2) Exocrine cells are reprogrammed by upregulating gene expression of the endocrine progenitor markers including PDX1, and Nkx-6.1 and downregulating KRT20 expression present in mature duct cells. (3) In acinar cells, the antiapoptotic action of gastrin is mediated by PI3K-AKT, ERK, and MAPK signalling. The exact mechanism for trans-differentiation of pancreatic exocrine cells into beta-like cells has not been elucidated, but molecular interactions can include gastrin induced upregulation of heparin-binding epidermal growth factor-like (HB-EGF), transactivation of EGFR, PI3K-AKT-mTORC1 and GLP-1-cAMP-PKA signalling cascades.
Disease-modifying pharmacological treatments of type 1 diabetes (T1D): Molecular mechanisms, target checkpoints and possible combinatorial treatments.

Pharmacological Reviews

After a century of extensive scientific investigations, there is still no curative or disease-modifying treatment available that can provide long-lasting remission for patients diagnosed with type 1 diabetes (T1D). Although T1D has historically been regarded as a classic autoimmune disorder targeting and destroying pancreatic islet β-cells, significant research has recently demonstrated that β-cells themselves also play a substantial role in the disease’s progression, which could explain some of the unfavorable clinical outcomes. We offer a thorough review of scientific and clinical insights pertaining to molecular mechanisms behind pathogenesis and the different therapeutic interventions in T1D covering over 20 possible pharmaceutical intervention treatments. The interventions are categorized as immune therapies, treatments targeting islet endocrine dysfunctions, medications with dual modes of action in immune and islet endocrine cells, and combination treatments with a broader spectrum of activity. We suggest that these collective findings can provide a valuable platform to discover new combinatorial synergies in search of the curative disease-modifying intervention for T1D. Significance Statement This research delves into the underlying causes of T1D and identifies critical mechanisms governing β-cell function in both healthy and diseased states. Thus, we identify specific pathways that could be manipulated by existing or new pharmacological interventions. These interventions fall into several categories: (1) immunomodifying therapies individually targeting immune cell processes, (2) interventions targeting β-cells, (3) compounds that act simultaneously on both immune cell and β-cell pathways, and (4) combinations of compounds simultaneously targeting immune and β-cell pathways.


Figure 1. Schematic diagram of the study design. (A) Illustration of the polygenic score (PGS) association analyses. Polygenic scores (PGS) were calculated in the UK Biobank for autism spectrum disorder (ASD) and associations were tested between the PGS and migraine, including its two major subtypes, with and without aura. (B) Illustration of the mediation analyses and moderation analysis performed in the study. Mediation analyses were performed to investigate if education, personality, and general health-related variables (body mass index, psychiatric comorbidities, vascular comorbidities, neurologic comorbidities and other comorbidities) mediate the association between ASD PGS and migraine. Moderation analysis was performed to investigate whether sex influenced the strength of the relationship between ASD PGS and migraine.
Figure 2. Flowchart of UK Biobank (UKB) participants for analysis. ICD-10, International Classification of Disease, version 10; MWA, migraine with aura; MWOA, migraine with aura.
Autism spectrum disorder polygenic score (ASD PGS) association with migraine and its major subtypes.
Mediation and moderation analyses for migraine. A. Interaction effects for migraine
Migraine and its major subtypes – with and without aura are associated with polygenic scores for autism

January 2025

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31 Reads

Cephalalgia

Background Individuals with autism spectrum disorder (ASD) experience a wide array of neurological, psychiatric and medical comorbidities, yet little attention has been given to the potential link between ASD and migraine, one of the most prevalent neurological disorders worldwide. This study aimed to investigate whether a genetic predisposition for ASD is linked to migraine and its major subtypes, with and without aura. Additionally, potential moderator and mediators of the association between ASD and migraine were explored. Methods Polygenic scores (PGS) for ASD were constructed based on the genome-wide association study by the Psychiatric Genomics Consortium, on the UK Biobank cohort dataset comprising 337,386 participants using PRSice-2. Regression analyses were performed to investigate the association of ASD PGS with migraine and its major subtypes, with and without aura. Sex was explored as a potential moderating factor. The mediation analyses took into consideration variables such as education, personality trait neuroticism, body mass index (BMI) and four categories of comorbidities (psychiatric, vascular, neurologic and others). Results ASD PGS were significantly and positively associated with migraine (odds ratio (OR) = 1.04, 95% confidence interval (CI) = 1.02–1.05, p < 0.002), migraine without aura (OR = 1.05, 95% CI = 1.02–1.07, p < 0.002) and migraine with aura (OR = 1.05, 95% CI = 1.02–1.07, p < 0.002). No moderating effect of sex on the association between ASD PGS and migraine was observed. As for potential mediators, only the personality trait neuroticism significantly mediated the association between ASD PGS and migraine, with the proportion of effect mediated 8.75% (95% CI = 4–18%). Conclusions Our study suggests that individuals genetically predisposed to autism are at higher risk of experiencing migraine, including the two major subtypes, with and without aura. While emphasizing the complex shared genetic and pathophysiological interactions of these conditions, the role of personality trait neuroticism as a mediator of this relationship is highlighted.


Identification and validation of depression-associated genetic variants in the UK Biobank cohort with transcriptome and DNA methylation analyses in independent cohorts

January 2025

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20 Reads

Heliyon

Depression is one of the most common psychiatric conditions resulting from a complex interaction of genetic, epigenetic and environmental factors. The present study aimed to identify independent genetic variants in the protein-coding genes that associate with depression and to analyze their transcriptomic and methylation profile. Data from the GWAS Catalogue was used to identify independent genetic variants for depression. The identified genetic variants were validated in the UK Biobank cohort and used to calculate a genetic risk score for depression. Data was also used from publicly available cohorts to conduct transcriptome and methylation analyses. Eight SNPs corresponding to six protein-coding genes (TNXB, NCAM1, LTBP3, BTN3A2, DAG1, FHIT) were identified that were highly associated with depression. These validated genetic variants for depression were used to calculate a genetic risk score that showed a significant association with depression (p < 0.05) but not with co-morbid traits. The transcriptome and methylation analyses suggested nominal significance for some gene probes (TNXB- and NCAM1) with depressed phenotype. The present study identified six protein-coding genes associated with depression and primarily involved in inflammation (TNXB), neuroplasticity (NCAM1 and LTBP3), immune response (BTN3A2), cell survival (DAG1) and circadian clock modification (FHIT). Our findings confirmed previous evidence for TNXB- and NCAM1 in the pathophysiology of depression and suggested new potential candidate genes (LTBP3, BTN3A2, DAG1 and FHIT) that warrant further investigation.


Citations (58)


... Ovarian carcinoma uses active chemerin to enhance growth, suggesting that chemerin antagonism is a therapeutic target. In particular, the chemerin receptors, chem 1 and chem2, as GPCRs are in a class of proteins for which many other drugs have been developed [73,74]. One small molecule antagonist reported to date of chem1 is 2-(alphanaphthoyl) ethyltrimethylammonium iodide (alpha-NETA), which does not have good specificity [75]. ...

Reference:

Active Forms of Chemerin Are Elevated in Human and Mouse Ovarian Carcinoma
GPCR drug discovery: new agents, targets and indications
  • Citing Article
  • March 2025

Nature Reviews Drug Discovery

... Despite its potential, ketamine's safety profile raises concerns, particularly related to dissociative side effects and the risk of misuse, which warrant careful consideration in clinical application [10]. Ketamine has now been approved by the U.S. Food and Drug Administration(FDA) for use as a sedative, general anesthetic, and analgesic [13]. ...

Ketamine and Esketamine in Clinical Trials: FDA-Approved and Emerging Indications, Trial Trends With Putative Mechanistic Explanations

... TOP II contains two isoforms, TOP IIα, mainly expressed in proliferation zones including the thymus, spleen, and bone marrow, and TOP IIβ, detected in a broader range of cell populations, such as the spleen, bone marrow, uterus, ovary, lymph nodes, adrenal gland, eye, bladder, and heart. For the TOP III isoforms, it showed three transcripts of TOP IIIα and two transcripts of TOP IIIβ, detected in the testis, heart, skeletal muscle and pancreas, thymus, testis, ovary, small intestine, heart, and skeletal muscle [10]. Under physiological conditions, TOPs perform transient DNA cleavages; the rapid relegation phase is well-tolerated by cells. ...

Recent developments of topoisomerase inhibitors: Clinical trials, emerging indications, novel molecules and global sales

Pharmacological Research

... Depending on Sex and Age LEAP2 may have distinct physiological functions depending on sex and age. Fasting plasma LEAP2 levels are similar between male and female infants at 6 months of age and before puberty (81,82). During puberty, however, plasma LEAP2 levels rise in girls, as compared to boys, and remain elevated in adult women (36,83,84). ...

The concentration of LEAP2 in human milk and infant plasma is positively associated with adiposity and body weight in the first year of life
  • Citing Article
  • September 2024

Journal of Nutrition

... Olaparib is a highly potent inhibitor, with an IC 50 of approximately 10 nM against human recombinant PARP1; however, it also inhibits other PARPs with variable potencies (ranging from 10 nM to 10 µM) and exhibits a 'trapping effect' on PARP1 at replication forks [57]. Even in cell-based systems, the detectable PARylation response is completely or nearcompletely inhibited at low (1-3−10 µM) concentrations [58][59][60][61][62]. Interestingly, although low doses of olaparib (1-10 µM) abolish PARylation, much higher concentrations (30-60 µM) are often needed for cancer cell killing [60][61][62][63][64][65][66][67]. One explanation is that even minimal residual PARP activity is enough for cell survival, so near-complete inhibition is required. ...

Blockade of the lncRNA-PART1-PHB2 axis confers resistance to PARP inhibitor and promotes cellular senescence in ovarian cancer
  • Citing Article
  • August 2024

Cancer Letters

... In addition to the potential effects on the extracellular matrix, statins may also contribute to tendon injury through their intended mechanism of action: cholesterol synthesis inhibition. This could lead to compromised cell membrane integrity in tenocytes, potentially increasing their susceptibility to damage [39]. However, despite the growing body of evidence linking statins to an increased risk of tendinopathy, reports are conflicting. ...

Off‐target effects of statins: molecular mechanisms, side effects and the emerging role of kinases

... However, one study found that postprandial plasma LEAP2 concentrations increases 1 hour after the ingestion of a carbohydrate-rich test meal in healthy individuals (35). Conversely, another study observed that LEAP2 levels decrease 2 hours after consuming a protein-rich test meal (36). ...

LEAP2 is associated with impulsivity and reward sensitivity depending on the nutritional status and decreases with protein intake in humans
  • Citing Article
  • August 2024

... The polygenic risk score (PRS) is a metric that is used to estimate an individual's genetic predisposition to a trait or disease, calculated using a genotype profile and relevant genome-wide association study (GWAS) data (Choi et al., 2020). An MRI study of ~31,000 adults, including ASD group and controls in the age group 40 -70 years, reported the PRS scores to be correlated with increased CSF volume (Mohammad et al., 2024). This recent study affirms that the CSF pathway is altered in ASD, and it may have some genetic connection also. ...

Association of polygenic scores for autism with volumetric MRI phenotypes in cerebellum and brainstem in adults

Molecular Autism

... The importance of clinical research is illustrated by the high number of trials identified by a search in the International Clinical Trials Registry Platform (ICTRP), a World Health Organization database, that reported the existence of 10606 depression studies in 2024 [1]. According to the US National Library of Medicine database for clinical trials (ClinicalTrials.gov), ...

Depression clinical trials worldwide: a systematic analysis of the ICTRP and comparison with ClinicalTrials.gov

Translational Psychiatry

... This underscores the importance of interpreting these results with caution and recognizing that they do not constitute definitive proof of differential methylation [1]. Recent findings on methyl-CpG binding domain proteins [27,57] and their role in recognizing and binding to genomic methylation sites provide mechanistic insights into how the differential methylation we observed may influence gene expression and cellular function [58,59]. The persistent predictive significance of CpG sites associated with PPARG and INS genes across our datasets aligns with the growing body of evidence suggesting these genes' fundamental role in GDM development. ...

Decoding depression: a comprehensive multi-cohort exploration of blood DNA methylation using machine learning and deep learning approaches

Translational Psychiatry