MicroRNA-637 Relieves Oxidative Damage in Human Melanocytes Through Down-Regulating Transient Receptor Potential Melastatin 2 Expression

2022 ◽  
Vol 12 (2) ◽  
pp. 373-380
Author(s):  
Xuecheng Sun ◽  
Tao Wang ◽  
Bo Huang ◽  
Gaobo Ruan ◽  
Jun Huang ◽  
...  

Background: Vitiligo, a chronic, autoimmune destruction of melanocytes, caused by the disappearance of epidermal melanocytes, but the mechanism is not fully understood. Although emerging evidence demonstrated that abnormal regulation of microRNAs (miRNAs) were associated with the pathogenesis of diseases, the functions of miR-637 in vitiligo remain unclear. Objective: This research was designed to explore the potential roles of miR-637 in hydrogen peroxide (H2O2)-induced human primary melanocytes in vitiligo. Methods: Human primary melanocytes were induced by 250 μmol/L H2O2 for 4 h to establish oxidative injury of melanocytes model. Cell viability and apoptosis analyzed by MTT and flow cytometry assay, respectively. The relevance between miR-637 and transient receptor potential melastatin 2 (TRPM2) was checked using TargetScan and dual luciferase reporter gene assay. The expression of miR-637 and TRPM2 was evaluated using qRT-PCR and/or Western blot analysis. Reactive oxygen species (ROS) accumulation, superoxide dismutase (SOD) and catalase (CAT) activities were measured using specific assay kits. In addition, the expression of Bcl-2 and Bax were evaluated using Western blot assay. Results: TRPM2 was up-regulated, while miR-637 was down-regulated in H2O2-stimulated human primary melanocytes. TRPM2 directly interacted with miR-637. Up-regulation of miR-637 memorably increased miR-637 level and inhibited TRPM2 expression. Furthermore, miR-637 mimic fortified cell viability, reduced apoptotic cells, enhanced Bcl-2 expression, reduced Bax level, as well as inhibited the ratio of Bax/Bcl-2 in H2O2-induced melanocytes. Meanwhile, miR-637 mimic obviously suppressed the accumulation of ROS and increased SOD and CAT activity. Nevertheless, all these findings were inverted by TRPM2-plasmid. Likewise, TRPM2-siRNA led to increased cell viability, reduced apoptotic cells, enhanced Bcl-2 expression, reduced Bax level, inhibited Bax/Bcl-2 ratio, inhibited ROS production, but increased SOD and CAT activity in H2O2-induced melanocytes. Conclusion: Our findings suggested that TRPM2 was up-regulated, while miR-637 was down-regulated in injurious melanocytes of vitiligo. Up-regulation of miR-637 relieved oxidative stress-stimulated melanocyte injury via down-regulating TRPM2 expression. Our results provide new insights into the functions of miR-637 in the development of vitiligo, indicating that miR-637 may be a latent target for vitiligo therapy.

2021 ◽  
Vol 11 (4) ◽  
pp. 736-742
Author(s):  
Bo Huang ◽  
Xuecheng Sun ◽  
Aie Xu

Background: Oxidative stress was reported to be involved in the progression of vitiligo. microRNAs (miRNAs) have been confirmed to display critical roles in vitiligo. In this study, we conjectured that miR-145-5p might be related to the development of vitiligo by regulating the key genes expression in melanocytes. Methods: H2O2 was used to induce the dysfunction of melanocytes. The levels of TRPM2 and miR-145-5p in H2O2-induced human primary melanocytes were assessed using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). TargetScan and Dual luciferase reporter gene assay were conducted to confirm the correlation between miR-145-5p and TRPM2. Cell viability and apoptosis were determined using MTT and Flow cytometry analysis. Reactive oxygen species (ROS), antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) were determined using specific assay kits. The levels of cleaved caspase-3 and pro-Caspase3 were measure by western blotting. Results: TRPM2 was upregulated while miR-145-5p was downregulated in H2O2-induced human primary melanocytes. Dual luciferase reporter assay confirmed that TRPM2 was a target gene of miR-145-5p. miR-145-5p mimic transfection significantly increased cell viability and inhibited cell apoptosis in H2O2-treated melanocytes. In addition, overexpression of miR-145-5p enhanced the antioxidant activity of SOD and CAT, and decreased intracellular ROS accumulation. Notably, these findings were abolished by TRPM2-plasmid. Conclusions: Taken together, our study demonstrated that oxidative stress induced up-regulation of TRPM2 and down-regulation of miR-145-5p in melanocytes. In addition, overexpression of miR-145-5p alleviated melanocytes destruction via targeting TRPM2. These results indicated that miR-145-5p might serve as a potential target for anti-oxidative therapy in vitiligo.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Lei Bao ◽  
Fernanda Festa ◽  
Christopher S. Freet ◽  
John P. Lee ◽  
Iwona M. Hirschler-Laszkiewicz ◽  
...  

Abstract Transient receptor potential melastatin channel subfamily member 2 (TRPM2) has an essential role in protecting cell viability through modulation of oxidative stress. TRPM2 is highly expressed in cancer. When TRPM2 is inhibited, mitochondria are dysfunctional, ROS levels are increased, and cell viability is reduced. Here, the importance of NF-E2-related factor (Nrf2) in TRPM2-mediated suppression of oxidant stress was explored. In TRPM2 depleted cells, antioxidant cofactors glutathione, NADPH, and NADH were significantly reduced. Cytoplasmic and nuclear expression of Nrf2 and of IQGAP1, a modulator of Nrf2 stability regulated by intracellular calcium, were decreased. Antioxidant enzymes transcriptionally regulated by Nrf2 and involved in GSH, NADPH, and NADH generation were significantly lower including PRX1 and PRX3, GPX4, GSTP1, GCLC, and MTHFD2. The glutamine pathway leading to GSH production was suppressed, and ATP and GTP levels were impaired. Reconstitution with wild type TRPM2 or Nrf2, but not TRPM2 pore mutant E960D, rescued expression of enzymes downstream of Nrf2 and restored GSH and GTP. Cell viability, ROS, NADPH, NADH, and ATP levels were fully rescued by TRPM2 and partially by Nrf2. These data show that TRPM2 maintains cell survival following oxidative stress through modulation of antioxidant pathways and cofactors regulated by Nrf2.


2020 ◽  
Vol 21 (10) ◽  
pp. 985-992 ◽  
Author(s):  
Koichi Inoue ◽  
Zhi-Gang Xiong ◽  
Takatoshi Ueki

: Transient receptor potential melastatin 7 (TRPM7), along with the closely related TRPM6, are unique channels that have dual operations: cation permeability and kinase activity. In contrast to the limited tissue distribution of TRPM6, TRPM7 is widely expressed among tissues and is therefore implicated in a variety of cellular functions physiologically and pathophysiologically. The discovery of TRPM7’s unique structure imparting dual ion channel and kinase activities shed light onto novel and peculiar biological functions, such as Mg2+ homeostasis, cellular Ca2+ flickering, and even intranuclear transcriptional regulation by a cleaved kinase domain translocated to nuclei. Interestingly, at a higher level, TRPM7 participates in several biological processes in the nervous and cardiovascular systems, in which excitatory responses in neurons and cardiomyocytes are critical for their function. Here, we review the roles of TRPM7 in cells involved in the nervous and cardiovascular systems and discuss its potential as a future therapeutic target.


2020 ◽  
Vol 17 (3) ◽  
pp. 249-258 ◽  
Author(s):  
Pavan Thapak ◽  
Mahendra Bishnoi ◽  
Shyam S. Sharma

Background: Diabetes is a chronic metabolic disorder affecting the central nervous system. A growing body of evidence has depicted that high glucose level leads to the activation of the transient receptor potential melastatin 2 (TRPM2) channels. However, there are no studies targeting TRPM2 channels in diabetes-induced cognitive decline using a pharmacological approach. Objective: The present study intended to investigate the effects of 2-aminoethoxydiphenyl borate (2-APB), a TRPM2 inhibitor, in diabetes-induced cognitive impairment. Methods: Streptozotocin (STZ, 50 mg/kg, i.p.) was used to induce diabetes in rats. Animals were randomly divided into the treatment group, model group and age-matched control and pre se group. 2-APB treatment was given for three weeks to the animals. After 10 days of behavioural treatment, parameters were performed. Animals were sacrificed at 10th week of diabetic induction and the hippocampus and cortex were isolated. After that, protein and mRNA expression study was performed in the hippocampus. Acetylcholinesterase (AchE) activity was done in the cortex. Results: : Our study showed the 10th week diabetic animals developed cognitive impairment, which was evident from the behavioural parameters. Diabetic animals depicted an increase in the TRPM2 mRNA and protein expression in the hippocampus as well as increased AchE activity in the cortex. However, memory associated proteins were down-regulated, namely Ca2+/calmodulin-dependent protein kinase II (CaMKII-Thr286), glycogen synthase kinase 3 beta (GSK-3β-Ser9), cAMP response element-binding protein (CREB-Ser133), and postsynaptic density protein 95 (PSD-95). Gene expression of parvalbumin, calsequestrin and brain-derived neurotrophic factor (BDNF) were down-regulated while mRNA level of calcineurin A/ protein phosphatase 3 catalytic subunit alpha (PPP3CA) was upregulated in the hippocampus of diabetic animals. A three-week treatment with 2-APB significantly ameliorated the alteration in behavioural cognitive parameters in diabetic rats. Moreover, 2-APB also down-regulated the expression of TRPM2 mRNA and protein in the hippocampus as well as AchE activity in the cortex of diabetic animals as compared to diabetic animals. Moreover, the 2-APB treatment also upregulated the CaMKII (Thr-286), GSK-3β (Ser9), CREB (Ser133), and PSD-95 expression and mRNA levels of parvalbumin, calsequestrin, and BDNF while mRNA level of calcineurin A was down-regulated in the hippocampus of diabetic animals. Conclusion: : This study confirms the ameliorative effect of TRPM2 channel inhibitor in the diabetes- induced cognitive deficits. Inhibition of TRPM2 channels reduced the calcium associated downstream signaling and showed a neuroprotective effect of TRPM2 channels in diabetesinduced cognitive impairment.


Pancreatology ◽  
2019 ◽  
Vol 19 ◽  
pp. S94
Author(s):  
Júlia Fanczal ◽  
Petra Pallagi ◽  
Marietta Görög ◽  
Csaba Péter Bíró ◽  
Tamara Madácsy ◽  
...  

2021 ◽  
Vol 34 (1) ◽  
pp. 121-122
Author(s):  
Yi-quan Dai ◽  
Xiao-xiao Yan ◽  
Yi-chen Lin ◽  
Hong-yu Chen ◽  
Xiao-ru Liu

Abstract Background To investigate the function of transient receptor potential melastatin 2 (TRPM2) in vascular reactivity induced by 5-hydroxytryptamine (5-HT) in the aorta during development of atherosclerosis in mice. Methods Forty mice were randomly divided into 4 groups: C57BL/6J on normal diet (C57 + ND), C57BL/6J on high-fat diet (C57 + HFD), apolipoprotein E gene knockout mice (ApoE−/−) on ND (ApoE−/− + ND), and ApoE−/− on HFD (ApoE−/− + HFD). They were fed with a ND or HFD for 16 weeks. Aortic TRPM2 expression and isometric contractions were analyzed. Results In the ApoE−/− + HFD group, body weight, blood glucose, and blood lipid concentrations were increased, and aortic plaques were developed. Compared with the other 3 groups, aortic TRPM2 mRNA and protein levels were significantly increased in the ApoE−/− + HFD group (P < 0.01). Aortic reactivity to 5-HT was enhanced in ApoE−/− + HFD mice with lower EC50 values. The enhanced reactivity to 5-HT was significantly inhibited by TRPM2 inhibitors, N-p-amylcinnamoyl anthranilic acid (1 µmol/l) and 2-aminoethyl diphenylborinate (10 µmol/l). Conclusions Aortic TRPM2 expression is upregulated in ApoE knockout mice fed with a HFD. Upregulation of TRPM2 enhances 5-HT vascular reactivity during development of atherosclerosis.


Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1893
Author(s):  
Chieko Hirota ◽  
Yui Takashina ◽  
Yuta Yoshino ◽  
Hajime Hasegawa ◽  
Ema Okamoto ◽  
...  

Background: A low level of serum magnesium ion (Mg2+) is associated with type 2 diabetes mellitus (T2D). However, the molecular mechanism of Mg2+ deficiency has not been fully clarified. The current study sought to assesses the effect of reactive oxygen species on the expression of Mg2+ channels and miRNA. Methods: The expression of Mg2+ channels and miRNA were examined by real-time polymerase chain reaction. Intracellular Mg2+ concentration was measured by Magnesium Green fluorescence measurement. Results: The mRNA level of transient receptor potential melastatin 6 (TRPM6), which functions as Mg2+ influx channel in the distal convoluted tubule (DCT) of the kidney, was decreased by glycated albumin (GA), but not by insulin in rat renal tubule-derived NRK-52E cells. The mRNA levels of TRPM7, a homologue of TRPM6, and CNNM2, a Mg2+ efflux transporter located at the basolateral membrane of DCT, were changed by neither GA nor insulin. The generation of reactive oxygen species (ROS) was increased by GA. Hydrogen peroxide (H2O2) dose-dependently decreased TRPM6 mRNA, but it inversely increased the reporter activity of TRPM6. H2O2 accelerated the degradation of TRPM6 mRNA in actinomycin D assay without affecting TRPM7 and CNNM2 mRNA expressions. Nine miRNAs were considered as candidates for the regulator of stability of TRPM6 mRNA. Among them, miR-24-3p expression was increased by H2O2. The H2O2-induced reduction of TRPM6 mRNA was rescued by miR-24-3p siRNA. Magnesium Green fluorescence measurement showed that Mg2+ influx is suppressed by H2O2, which was rescued by an antioxidant and miR-24-3p siRNA. Conclusions: We suggest that GA decreases TRPM6 expression mediated by the elevation of ROS and miR-24-3p in renal tubular epithelial cells of T2D.


Tumor Biology ◽  
2021 ◽  
Vol 43 (1) ◽  
pp. 11-26
Author(s):  
Maike Busch ◽  
Natalia Miroschnikov ◽  
Jaroslaw Thomas Dankert ◽  
Marc Wiesehöfer ◽  
Klaus Metz ◽  
...  

BACKGROUND: Retinoblastoma (RB) is the most common childhood eye cancer. Chemotherapeutic drugs such as etoposide used in RB treatment often cause massive side effects and acquired drug resistances. Dysregulated genes and miRNAs have a large impact on cancer progression and development of chemotherapy resistances. OBJECTIVE: This study was designed to investigate the involvement of retinoic acid receptor alpha (RARα) in RB progression and chemoresistance as well as the impact of miR-138, a potential RARα regulating miRNA. METHODS: RARα and miR-138 expression in etoposide resistant RB cell lines and chemotherapy treated patient tumors compared to non-treated tumors was revealed by Real-Time PCR. Overexpression approaches were performed to analyze the effects of RARα on RB cell viability, apoptosis, proliferation and tumorigenesis. Besides, we addressed the effect of miR-138 overexpression on RB cell chemotherapy resistance. RESULTS: A binding between miR-138 and RARα was shown by dual luciferase reporter gene assay. The study presented revealed that RARα is downregulated in etoposide resistant RB cells, while miR-138 is endogenously upregulated. Opposing RARα and miR-138 expression levels were detectable in chemotherapy pre-treated compared to non-treated RB tumor specimen. Overexpression of RARα increases apoptosis levels and reduces tumor cell growth of aggressive etoposide resistant RB cells in vitro and in vivo. Overexpression of miR-138 in chemo-sensitive RB cell lines partly enhances cell viability after etoposide treatment. CONCLUSIONS: Our findings show that RARα acts as a tumor suppressor in retinoblastoma and is downregulated upon etoposide resistance in RB cells. Thus, RARα may contribute to the development and progression of RB chemo-resistance.


2021 ◽  
pp. 1-13
Author(s):  
Jiachen Liu ◽  
Laijiang Chen ◽  
Jun Huang ◽  
Shujie Guo ◽  
Dingliang Zhu ◽  
...  

Remodeling of the arteries is one of the pathological bases of hypertension. We have previously shown that transient receptor potential melastatin 7 (TRPM7) aggravates the vascular adventitial remodeling caused by pressure overload in the transverse aortic constriction (TAC) model. In this study, we sought to explore the functional expression and downstream signaling of TRPM7 in vascular adventitial fibroblasts (AFs) stimulated by mechanical stretching stress (MSS). The expression of TRPM7 was upregulated with a concomitant translocation to the cytoplasm in the AFs stimulated with 20% MSS. Meanwhile, the expression of α-smooth muscle actin (α-SMA), a marker of transformation from AFs to myofibroblasts (MFs) was also increased. Moreover, AF-conditioned medium caused a significant migration of macrophages after treatment with MSS and contained high levels of monocyte chemotactic protein-1 (MCP-1), interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor-α (TNF-α). Pharmacological and RNA interference approaches using the TRPM7 inhibitor 2-aminoethoxydiphenyl borate (2-APB) and specific anti-TRPM7 small interfering RNA (si­RNA-TRPM7) abrogated these changes significantly. Further exploration uncloaked that inhibition of TRPM7 reduced the phosphorylation of p38 MAP kinase (p38MAPK) and c-Jun N-terminal kinase (JNK) in the AFs stimulated with MSS. Furthermore, inhibition of the phosphorylation of p38MAPK or JNK could also alleviate the MSS-induced expression of α-SMA and secretion of inflammatory factors. These observations indicate that activated TRPM7 participates in the phenotypic transformation and inflammatory action of AFs in response to MSS through the p38MAPK/JNK pathway and suggest that TRPM7 may be a potential therapeutic target for vascular remodeling caused by hemodynamic changes in hypertension.


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