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The ADPR-induced stimulation of TRPM2 was increased in the ARPE19 by the treatment of HGu (33 mM for 48 h), although TRPM2 activity was diminished by the treatment of CRV (200 μM for 24 h). (Mean ± SD and n = 3–6). The patch-clamp records were taken as whole cell (W.C.) configuration after inducing the voltage-clamp (at − 60 mV). (a) The image of W.C. configuration in the cells of patch-chamber. (b) The image of W.C. configuration between cell and patch pipette. (c) The current records of HGu without cytosolic ADPR (1 mM) stimulation. (d) The TRPM2 current and current (I)/voltage (V) rate changes in the NGu + ADPR group. The ADPR (1 mM) stimulation-induced TRPM2 currents were inhibited by the administration of ACA (25 μM) and NMDG⁺. (e) The TRPM2 current and I/V changes in the HGu + ADPR group. (f) The currents of the HGu + ADPR + CRV group after ADPR stimulation. (g) The TRPM2 currents from the NGu + ADPR + CRV group after ADPR stimulation. (h) The TRPM2 activation times in the NGu and HGu after ADPR stimulation were indicated by columns. (i) The mean current density changes in the four groups (NGu, NGu + CRV, HGu + CRV, and HGu + CRV) with/without ADPR and ACA treatments (ap ≤ 0.05 vs. NGu. bp ≤ 0.05 vs. NGu + ADPR. cp ≤ 0.05 vs. HGu + ADPR)
Source publication
Purpose
The concentration of plasma high glucose (HGu) in diabetes mellitus (DM) induces the retinal pigment epithelial cell (ARPE19) death via the increase of inflammation, cytosolic (cytROS), and mitochondrial (mitROS) free oxygen radical generations. Transient potential melastatin 2 (TRPM2) cation channel is stimulated by cytROS and mitROS. Henc...
Citations
... Carvacrol has also been recently proposed as an effective TRPM2 antagonist in SH-SY5Y neuronal, BV-2 microglial, and HEK293 (human epithelial kidney derived) cells (Nazıroğlu, 2022). In the context of the eye, specifically retinal pigment epithelial cells, Selenium reduced TRPM2 activity following hypoxia (Özkaya et al., 2021), and Carvacrol attenuated TRPM2 activity following high glucose insult (diabetes mellitus model) (Daldal and Nazıroğlu, 2022). Considering these findings, there is an implication that multiple stimuli (such as amyloid-β, docetaxel, INF-gamma, hypoxia, or high glucose) generate ROS as a second messenger to produce TRPM2 dysfunction. ...
Efficient cellular communication is essential for the brain to regulate diverse functions like muscle contractions, memory formation and recall, decision-making, and task execution. This communication is facilitated by rapid signaling through electrical and chemical messengers, including voltage-gated ion channels and neurotransmitters. These messengers elicit broad responses by propagating action potentials and mediating synaptic transmission. Calcium influx and efflux are essential for releasing neurotransmitters and regulating synaptic transmission. Mitochondria, which are involved in oxidative phosphorylation, and the energy generation process, also interact with the endoplasmic reticulum to store and regulate cytoplasmic calcium levels. The number, morphology, and distribution of mitochondria in different cell types vary based on energy demands. Mitochondrial damage can cause excess reactive oxygen species (ROS) generation. Mitophagy is a selective process that targets and degrades damaged mitochondria via autophagosome-lysosome fusion. Defects in mitophagy can lead to a buildup of ROS and cell death. Numerous studies have attempted to characterize the relationship between mitochondrial dysfunction and calcium dysregulation in neurodegenerative diseases such as Alzheimer’s Disease, Parkinson’s Disease, Huntington’s Disease, Amyotrophic lateral sclerosis, spinocerebellar ataxia, and aging. Interventional strategies to reduce mitochondrial damage and accumulation could serve as a therapeutic target, but further research is needed to unravel this potential. This review offers an overview of calcium signaling related to mitochondria in various neuronal cells. It critically examines recent findings, exploring the potential roles that mitochondrial dysfunction might play in multiple neurodegenerative diseases and aging. Furthermore, the review identifies existing gaps in knowledge to guide the direction of future research.
... Both cytosolic and mitochondrial ROS levels were markedly increased in ARPE-19 cells, confirming that the hyperglycemic state was characterized by high oxidative stress. Similar to previous studies, the present results showed that culturing ARPE-19 cells with HG leads to apoptosis and DNA damage via ROS generation [48][49][50][51]. However, in the presence of β-asarone, the production of ROS and induction of apoptosis and DNA damage were significantly abolished in HG-treated ARPE-19 cells. ...
Diabetic retinopathy (DR) is the leading cause of vision loss and a major complication of diabetes. Hyperglycemia-induced accumulation of reactive oxygen species (ROS) is an important risk factor for DR. β-asarone, a major component of volatile oil extracted from Acori graminei Rhizoma, exerts antioxidant effects; however, its efficacy in DR remains unknown. In this study, we investigated whether β-asarone inhibits high-glucose (HG)-induced oxidative damage in human retinal pigment epithelial (RPE) ARPE-19 cells. We found that β-asarone significantly alleviated cytotoxicity, apoptosis, and DNA damage in HG-treated ARPE-19 cells via scavenging of ROS generation. β-Asarone also significantly attenuated the excessive accumulation of lactate dehydrogenase and mitochondrial ROS by increasing the manganese superoxide dismutase and glutathione activities. HG conditions markedly increased the release of interleukin (IL)-1β and IL-18 and upregulated their protein expression and activation of the nuclear factor-kappa B (NF-κB) signaling pathway, whereas β-asarone reversed these effects. Moreover, expression levels of the NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome multiprotein complex molecules, including thioredoxin-interacting protein, NLRP3, apoptosis-associated speck-like protein containing a caspase-recruitment domain, and cysteinyl aspartate-specific proteinase-1, were increased in ARPE-19 cells under HG conditions. However, their expression levels remained similar to those in the control group in the presence of β-asarone. Therefore, β-asarone protects RPE cells from HG-induced injury by blocking ROS generation and NF-κB/NLRP3 inflammasome activation, indicating its potential as a therapeutic agent for DR treatment.
... Stimulation of the transient receptor potential melastatin 2 (TRPM2) channels in ARPE19 cells by a number of drugs, including bevacizumab [11] and cisplatin [15], has been reported to cause adverse oxidative and apoptotic effects. However, these negative effects have been counteracted by the use of TRPM2 channel antagonists, including carvacrol (CRV) and N-(p-amylcinnamoyl)anthranilic acid (ACA) [12,13,16], as well as antioxidants, such as CRC and glutathione [11,15]. The involvement of TRPM2 has not been reported in HCQ-mediated overload cCa 2+ influx and mROS generation in ARPE19 cells. ...
... The influx of Ca 2+ modulates the physiological functions of retinal cells [17]. However, increased mROS production and apoptosis are induced by elevated Ca 2+ accumulation within the mitochondria via the activation of TRPM2 in ARPE19 cells [12,13,15,16]. CRC is a bright-yellow material produced by plants of the Curcuma longa genus. ...
... The detrimental oxidative and apoptotic effects of medicines such as HCQ and chloroquine have been experimentally studied using ARPE19 cells as a model of the human RPE [9,11,12]. Recently, it was also reported that a TRPM2 channel naturally exists in ARPE19 cells [16,27]. These factors led us to choose the cells used in the current investigation, which were a gift from Professor Suat Erdoğan (Trakya University, Edirne, Turkey). ...
Purpose
Hydroxychloroquine (HCQ) is used in the treatment of several diseases, such as malaria, Sjögren's disease, Covid-19, and rheumatoid arthritis. However, HCQ induces retinal pigment epithelium death via the excessive increase of cytosolic (cROS) and mitochondrial (mROS) free oxygen radical production. The transient receptor potential melastatin 2 (TRPM2) cation channel is stimulated by ADP-ribose (ADPR), cROS, and mROS, although it is inhibited by curcumin (CRC). We aimed to investigate the modulating action of CRC on HCQ-induced TRPM2 stimulation, cROS, mROS, apoptosis, and death in an adult retinal pigment epithelial 19 (ARPE19) cell line model.
Material and methods
ARPE19 cells were divided into four groups: control (CNT), CRC (5 µM for 24 h), HCQ (60 µM for 48 h), and CRC + HCQ groups.
Results
The levels of cell death (propidium iodide positive cell numbers), apoptosis markers (caspases -3, -8, and -9), oxidative stress (cROS and mROS), mitochondria membrane depolarization, TRPM2 current density, and intracellular free Ca²⁺ and Zn²⁺ fluorescence intensity were upregulated in the HCQ group after stimulation with hydrogen peroxide and ADPR, but their levels were downregulated by treatments with CRC and TRPM2 blockers (ACA and carvacrol). The HCQ-induced decrease in retinal live cell count and cell viability was counteracted by treatment with CRC.
Conclusion
HCQ-mediated overload Ca²⁺ influx and retinal oxidative toxicity were induced in an ARPE19 cell line through the stimulation of TRPM2, although they were attenuated by treatment with CRC. Hence, CRC may be a potential therapeutic antioxidant for TRPM2 activation and HCQ treatment-induced retinal oxidative injury and apoptosis.
... On the other hand, TO derived from Thymus vulgaris plants was shown to be much lower in carvacrol (1.56%) [3]. Similar to thymol, carvacrol exhibits anti-inflammatory properties and has been shown to protect retinal pigment epithelial cells against inflammation, oxidative stress, and apoptosis induced by high glucose levels [35]. Mechanistically, the transient potential melastatin 2 (TRPM2) cation channel was inhibited by carvacrol and thus provided protection against excessive calcium influx and ROS species. ...
Thyme oil (TO) is derived from the flowers of various plants belonging to the genus Thymus. It has been used as a therapeutic agent since ancient times. Thymus comprises numerous molecular species exhibiting diverse therapeutic properties that are dependent on their biologically active concentrations in the extracted oil. It is therefore not surprising that oils extracted from different thyme plants present different therapeutic properties. Furthermore, the phenophase of the same plant species has been shown to yield different anti-inflammatory properties. Given the proven efficacy of TO and the diversity of its constituents, a better understanding of the interactions of the various components is warranted. The aim of this review is to gather the latest research findings regarding TO and its components with respect to their immunomodulatory properties. An optimization of the various components has the potential to yield more effective thyme formulations with increased potency.
... The patch-clamp technique is one of the essential techniques to determine the activation of cation channels, including the TRPM2 channel (Daldal and Nazıroğlu 2022). In patchclamp analyses, we induced whole cell configuration in cells. ...
... Studies have stated that an excessive increase in TRPM2 channel activation may cause a large amount of Ca 2+ ions to enter the cell. Intracellular Ca 2+ ion accumulation can trigger caspase activation by activating different mechanisms, which may cause the death of cells (Daldal and Nazıroğlu 2022;Yıldızhan and Nazıroğlu 2022). In our study, after determining the increase in TRPM2 channel activation in SH-SY5Y cells with patch-clamp analyses after PTZ incubation, we examined Casp/3, Casp/9, and cell viability levels among groups. ...
Valproic acid (VPA) is one of the most widely used antiepileptic drugs. The protective role of VPA and the role of the TRPM2 channel in this mechanism in developing neuronal damage due to increased pentylenetetrazol (PTZ)-induced neurotoxicity in SH-SY5Y cells were not clarified. Here, we investigated the role of VPA via modulation of TRPM2 channel on cell death and oxidative neurotoxicity in SH-SY5Y cells. The SH-SY5Y cell toxicity model was constructed by treating SH-SY5Y cells with PTZ. The VPA and TRPM2 channel antagonist N-(p-amylcinnamoyl) anthranilic acid (ACA) were added to prevent neurotoxicity in PTZ-induced SH-SY5Y cells. The role of the VPA and TRPM2 channel was evaluated using an ELISA kit and patch-clamp. Primarily, antioxidant (GSH and GSH-Px) and oxidative stress (MDA and ROS) levels and inflammatory factors (IL-1β, IL-6, and TNF-α) in cells were determined by ELISA kits. Then, TRPM2 channel activation in cells was detected using both the ELISA kit and patch-clamp methods. In addition, apoptosis and cell viability levels in cells were determined by performing PARP1, caspase-3, caspase-9, and CCK-8 assays by ELISA kits. Our results showed that the TRPM2 channel is vital in damage formation in PTZ-induced cells. Furthermore, we observed that VPA attenuated PTZ-induced neurotoxicity by suppressing cells' oxidative stress and inflammation, and reducing TRPM2 channel activation. In our study, in which the protective effect of VPA and the role of the TRPM2 channel in PTZ-induced SH-SY5Y cells were investigated for the first time, we can conclude that VPA treatment and TRPM2 channel blockade can suppress PTZ-induced neurotoxicity.
... The DBTRG-05MG tumor cells (Ş ap Institute, Ankara, Türkiye) were used in the current study. Because high glucose medium has an oxidizing effect on cells [27], the DBTRG-05MG cells were grown in DMEM medium with low glucose (1 g/l) (DMEM-LPXA, Capricorn GmbH, Ankara, Türkiye). Fetal bovine serum (10%) and penicillin-streptomycin (1%) (both from Sigma-Aldrich, Istanbul, Türkiye) were also added to the medium [11]. ...
... The DBTRG-05MG cells were primarily divided into four groups as follows: (1) the control (CNT) group, which did not receive any treatment with N-(p-amylcinnamoyl)anthranilic acid (ACA), 2-aminoethyl diphenylborinate (2APB), CiSP, or AgNP but was maintained in the same cell culture conditions for 24-48 h; (2) the CiSP group, which received 25 μM CiSP for 24 h; (3) the AgNP group, which received 100 μg/ml AgNP for 48 h; and (4) the CiSP + AgNP group, which received both. In some experiments, the cells were further incubated with 25 μM ACA or 100 μM 2APB for 30 min [11,27]. ...
We investigated the effects of silver nanoparticle (AgNP) and cisplatin (CiSP) exposure via the activation of TRPM2 cation channels in glioblastoma (DBTRG-05MG) cell line.
The cells were divided into four groups as control, AgNPs (100 μM for 48 h), CiSP (25 μM for 24 h), and CiSP + AgNPs. We found that the cytotoxic, oxidant and apoptotic actions of CiSP were further stimulated through the activation of TRPM2 (via ADP-ribose and H2O2) in the cells by the treatment of AgNPs. The actions were decreased in the cells by the treatments of TRPM2 antagonists (ACA and 2APB). The apoptotic actions of AgNPs were induced by the stimulation of propidium iodide positive DBTRG-05MG rate, caspase −3, caspase −8, and caspase −9 activations, their oxidant actions were acted by the increase of mitochondrial membrane depolarization, lipid peroxidation, mitochondrial oxygen free radicals (ROS), and cytosolic ROS, but the decrease of total antioxidant status, glutathione, and glutathione peroxidase. The accumulation of cytosolic free Ca²⁺ and Zn²⁺ into mitochondria via the activation of TRPM2 current density and activity accelerated oxidant and apoptotic actions of AgNPs in the cells.
We found that the combination of AgNPs and CiSP was synergistic via the stimulation of TRPM2 for treatment of DBTRG-05MG cells. The combination of AgNPs and CiSP showed a favorable action via the stimulation of TRPM2 in the treatment of glioblastoma tumor cells.
Ageing is a natural process characterized by a time-dependent decline of physiological integrity that compromises functionality and inevitably leads to death. This decline is also quite relevant in major human pathologies, being a primary risk factor in neurodegenerative diseases, metabolic disorders, cardiovascular diseases and musculoskeletal disorders. Bearing this in mind, it is not surprising that research aiming at improving human health during this process has burst in the last decades. Importantly, major hallmarks of the ageing process and phenotype have been identified, this knowledge being quite relevant for future studies towards the identification of putative pharmaceutical targets, enabling the development of preventive/therapeutic strategies to improve health and longevity. In this context, aromatic plants have emerged as a source of potential bioactive volatile molecules, mainly monoterpenes, with many studies referring to their anti-ageing potential. Nevertheless, an integrated review on the current knowledge is lacking, with several research approaches studying isolated ageing hallmarks or referring to an overall anti-ageing effect, without depicting possible mechanisms of action. Herein, we aim to provide an updated systematization of the bioactive potential of volatile monoterpenes on recently proposed ageing hallmarks, and highlight the main mechanisms of action already identified, as well as possible chemical entity–activity relations. By gathering and categorizing the available scattered information, we also aim to identify important research gaps that could help pave the way for future research in the field.
Background:
Hyperglycemia-induced accumulation of reactive oxygen species (ROS) is a major risk factor for diabetic retinopathy (DR). Sarsasapogenin is a natural steroidal saponin that is known to have excellent antidiabetic effects and improve diabetic complications, but its potential efficacy and mechanism for DR are unknown.
Objectives:
The current study was designed to explore whether sarsasapogenin inhibits hyperglycemia-induced oxidative stress in human retinal pigment epithelial (RPE) ARPE-19 cells and to elucidate the molecular mechanisms.
Methods:
To mimic hyperglycemic conditions, ARPE-19 cells were cultured in medium containing high glucose (HG). The suppressive effects of sarsasapogenin on HG-induced cell viability reduction, apoptosis and ROS production were investigated. In addition, the relevance of the nuclear factor-kappa B (NF-κB)/NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome signaling pathway was explored to investigate the mechanism of antioxidant and anti-inflammatory activity of sarsasapogenin.
Results:
Sarsasapogenin significantly alleviated cytotoxicity and apoptosis in HG-treated ARPE-19 cells through inhibition of intracellular ROS generation. Sarsasapogenin also effectively attenuated HG-induced excess accumulation of mitochondrial superoxide, reduction of glutathione content, and inactivation of manganese superoxide dismutase and glutathione peroxidase. The HG condition markedly increased the expression and maturation of interleukin (IL)-1β and IL-18 through the activation of the NF-kB signaling pathway, whereas sarsasapogenin reversed these effects. Moreover, although the expression of NLRP3 inflammasome multiprotein complex molecules was increased in ARPE-19 cells cultured under HG conditions, their levels remained similar to the control group in the presence of sarsasapogenin.
Conclusion:
Sarsasapogenin could protect RPE cells from HG-induced injury by inhibiting ROS generation and NF-κB/NLRP3 inflammasome pathway, suggesting its potential as a therapeutic agent to improve the symptoms of DR.
