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Kim BJ, Hong C. Role of transient receptor potential melastatin type 7 channel in gastric cancer. Integr Med Res 2016; 5:124-130. [PMID: 28462107 PMCID: PMC5381434 DOI: 10.1016/j.imr.2016.04.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Revised: 04/01/2016] [Accepted: 04/05/2016] [Indexed: 01/11/2023] Open
Abstract
Transient receptor potential (TRP) proteins are a family of ion channels, which are responsible for a wide array of cellular functions. In particular, TRP melastatin type (TRPM) 7 is expressed everywhere and permeable to divalent cations such as Mg2+ and Ca2+. It contains a channel and a kinase domain. Recent studies indicate that activation of TRPM7 plays an important role in the growth and survival of gastric cancer cells. In this review, we describe and discuss the findings of recent studies that have provided novel insights of the relation between TRPM7 and gastric cancer.
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Affiliation(s)
- Byung Joo Kim
- Division of Longevity and Biofunctional Medicine, School of Korean Medicine, Pusan National University, Yangsan, Korea.,Healthy Aging Korean Medical Research Center, School of Korean Medicine, Pusan National University, Yangsan, Korea
| | - Chansik Hong
- Department of Physiology, Seoul National University, College of Medicine, Seoul, Korea
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Low-density lipoprotein receptors play an important role in the inhibition of prostate cancer cell proliferation by statins. Prostate Int 2016; 4:56-60. [PMID: 27358845 PMCID: PMC4916060 DOI: 10.1016/j.prnil.2016.02.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 02/20/2016] [Accepted: 02/24/2016] [Indexed: 01/06/2023] Open
Abstract
Background There are some reports about the antitumor effects of statins in these days. Statins decrease the level of cholesterol in the blood by inhibiting 3-hydroxy-3-methylglutaryl-coenzyme A reductase. Inhibition of this enzyme decreases intracellular cholesterol synthesis. Thus, the expression of low-density lipoprotein receptor (LDLr) is increased to import more cholesterol from the bloodstream. In this study, we assessed the effects of statins on the proliferation of prostate cancer cells, and studied the relationship between the expression of LDLr and the effects of statins. Methods Simvastatin was used in the experiments. We studied the effect of simvastatin on PC-3 and LNCaP cell proliferation using the MTS assay, and evaluated the expression of LDLr after administration of simvastatin by quantitative polymerase chain reaction and Western blotting. Intracellular cholesterol levels in the prostate cancer cells were measured after administration of simvastatin. Furthermore, small interfering RNA (siRNA) was used to knockdown the gene expression of LDLr. Results In PC-3 cells, simvastatin inhibited cell proliferation. In LNCaP cells, only a high concentration of simvastatin (100μM) inhibited cell proliferation. In LNCaP cells, the protein level of LDLr was increased by simvastatin. In PC-3 cells, the protein levels of LDLr were unregulated. In PC-3 cells, but not in LNCaP cells, intracellular cholesterol levels were significantly decreased by simvastatin. After knocking down LDLr expression by siRNA, intracellular cholesterol levels were decreased, and cell proliferation was inhibited by simvastatin in LNCaP cells. Conclusion Simvastatin inhibited prostate cancer cell growth by decreasing cellular cholesterol and could be more effective in androgen-independent prostate cancer, where there is loss of regulation of LDLr expression. LDLr was shown to play an important role in the statin-induced inhibition of prostate cancer cell proliferation. These results suggest that future studies evaluating the cholesterol-lowering effects of statin may lead to new approaches to the prevention and treatment of prostate cancer.
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Lin J, Zhou S, Zhao T, Ju T, Zhang L. TRPM7 channel regulates ox-LDL-induced proliferation and migration of vascular smooth muscle cells via MEK-ERK pathways. FEBS Lett 2016; 590:520-32. [PMID: 26900082 DOI: 10.1002/1873-3468.12088] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 01/20/2016] [Accepted: 01/25/2016] [Indexed: 12/16/2022]
Affiliation(s)
- Jinghan Lin
- Department of Neurology; The First Affiliated Hospital of Harbin Medical University; China
| | - Shanshan Zhou
- Department of Neurology; The First Affiliated Hospital of Harbin Medical University; China
| | - Tingting Zhao
- Department of Neurology; The First Affiliated Hospital of Harbin Medical University; China
| | - Ting Ju
- Department of Neurology; The First Affiliated Hospital of Harbin Medical University; China
| | - Liming Zhang
- Department of Neurology; The First Affiliated Hospital of Harbin Medical University; China
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Allott EH, Howard LE, Aronson WJ, Terris MK, Kane CJ, Amling CL, Cooperberg MR, Freedland SJ. Racial Differences in the Association Between Preoperative Serum Cholesterol and Prostate Cancer Recurrence: Results from the SEARCH Database. Cancer Epidemiol Biomarkers Prev 2016; 25:547-54. [PMID: 26809276 DOI: 10.1158/1055-9965.epi-15-0876] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 01/08/2016] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Black men are disproportionately affected by both cardiovascular disease and prostate cancer. Epidemiologic evidence linking dyslipidemia, an established cardiovascular risk factor, and prostate cancer progression is mixed. As existing studies were conducted in predominantly non-black populations, research on black men is lacking. METHODS We identified 628 black and 1,020 non-black men who underwent radical prostatectomy and never used statins before surgery in the Shared Equal Access Regional Cancer Hospital (SEARCH) database. Median follow-up was 2.9 years. The impact of preoperative hypercholesterolemia on risk of biochemical recurrence was examined using multivariable, race-stratified proportional hazards. In secondary analysis, we examined associations with low-density lipoprotein (LDL), high-density lipoprotein (HDL), and triglycerides, overall and among men with dyslipidemia. RESULTS High cholesterol was associated with increased risk of recurrence in black [HR(per10 mg/dL) 1.06; 95% confidence interval (CI), 1.02-1.11] but not non-black men (HR(per10 mg/dL) 0.99; 95% CI, 0.95-1.03; P(interaction) = 0.011). Elevated triglycerides were associated with increased risk in both black and non-black men (HR(per10 mg/dL) 1.02; 95% CI, 1.00-1.03 and 1.02; 95% CI, 1.00-1.02, respectively; P(interaction) = 0.458). There were no significant associations between LDL or HDL and recurrence risk in either race. Associations with cholesterol, LDL, and triglycerides were similar among men with dyslipidemia, but low HDL was associated with increased risk of recurrence in black, but not non-black men with dyslipidemia (P(interaction) = 0.047). CONCLUSION Elevated cholesterol was a risk factor for recurrence in black but not non-black men, whereas high triglycerides were associated with increased risk regardless of race. IMPACT Significantly contrasting associations by race may provide insight into prostate cancer racial disparities.
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Affiliation(s)
- Emma H Allott
- Department of Epidemiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina. Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Lauren E Howard
- Department of Biostatistics and Bioinformatics, Duke University School of Medicine, Durham, North Carolina
| | - William J Aronson
- Urology Section, Department of Surgery, Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California. Department of Urology, UCLA School of Medicine, Los Angeles, California
| | - Martha K Terris
- Section of Urology, Veterans Affairs Medical Center, Augusta, Georgia. Section of Urology, Medical College of Georgia, Augusta, Georgia
| | - Christopher J Kane
- Urology Department, University of California San Diego Health System, San Diego, California
| | | | - Matthew R Cooperberg
- Department of Urology, UCSF Helen Diller Family Comprehensive Cancer Center, San Francisco, California
| | - Stephen J Freedland
- Cedars Sinai Medical Center, Los Angeles, California. Division of Urology, Veterans Affairs Medical Center, Durham, North Carolina.
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Schäfer S, Ferioli S, Hofmann T, Zierler S, Gudermann T, Chubanov V. Mibefradil represents a new class of benzimidazole TRPM7 channel agonists. Pflugers Arch 2015; 468:623-34. [PMID: 26669310 DOI: 10.1007/s00424-015-1772-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 12/02/2015] [Accepted: 12/04/2015] [Indexed: 01/16/2023]
Abstract
Transient receptor potential cation channel, subfamily M, member 7 (TRPM7) is a bi-functional protein comprising an ion channel moiety covalently linked to a protein kinase domain. Currently, the prevailing view is that a decrease in the cytosolic Mg(2+) concentration leads to activation of divalent cation-selective TRPM7 currents. TRPM7 plays a role in immune responses, hypotension, tissue fibrosis, and tumor progression and, therefore, represents a new promising therapeutic target. Because of the dearth of pharmacological tools, our mechanistic understanding of the role of TRPM7 in physiology and pathophysiology still lags behind. Therefore, we have recently carried out a high throughput screen for small-molecule activators of TRPM7. We have characterized the phenanthrene naltriben as a first stimulatory agonist of the TRPM7 channel. Surprisingly, the effect of naltriben on TRPM7 was found to be unaffected by the physiological levels of cytosolic Mg(2+). Here, we demonstrate that mibefradil and NNC 50-0396, two benzimidazole relatives of the TRPM7 inhibitor NS8593, are positive modulators of TRPM7. Using Ca(2+) imaging and the patch-clamp technique, we show that mibefradil activates TRPM7-mediated Ca(2+) entry and whole-cell currents. The response to mibefradil was fast, reversible, and reproducible. In contrast to naltriben, mibefradil efficiently activates TRPM7 currents only at physiological intracellular Mg(2+) concentrations, and its stimulatory effect was fully abrogated by high internal Mg(2+) levels. Consequently, a TRPM7 variant harboring a gain-of-function mutation was insensitive to further mibefradil activation. Finally, we observed that the effect of mibefradil was selective for TRPM7 when various TRP channels were tested. Taken together, mibefradil acts as a Mg(2+)-regulated agonist of the TRPM7 channel and, hence, uncovers a new class of TRPM7 agonists.
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Affiliation(s)
- Sebastian Schäfer
- Walther-Straub-Institute of Pharmacology and Toxicology, University of Munich, Goethestrasse 33, 80336, Munich, Germany
| | - Silvia Ferioli
- Walther-Straub-Institute of Pharmacology and Toxicology, University of Munich, Goethestrasse 33, 80336, Munich, Germany
| | - Thomas Hofmann
- Walther-Straub-Institute of Pharmacology and Toxicology, University of Munich, Goethestrasse 33, 80336, Munich, Germany
| | - Susanna Zierler
- Walther-Straub-Institute of Pharmacology and Toxicology, University of Munich, Goethestrasse 33, 80336, Munich, Germany
| | - Thomas Gudermann
- Walther-Straub-Institute of Pharmacology and Toxicology, University of Munich, Goethestrasse 33, 80336, Munich, Germany
- Comprehensive Pneumology Center Munich (CPC-M), German Center for Lung Research, Munich, Germany
- DZHK (German Centre for Cardiovascular Research), Munich Heart Alliance, Munich, Germany
| | - Vladimir Chubanov
- Walther-Straub-Institute of Pharmacology and Toxicology, University of Munich, Goethestrasse 33, 80336, Munich, Germany.
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"TRP inflammation" relationship in cardiovascular system. Semin Immunopathol 2015; 38:339-56. [PMID: 26482920 PMCID: PMC4851701 DOI: 10.1007/s00281-015-0536-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 10/08/2015] [Indexed: 02/07/2023]
Abstract
Despite considerable advances in the research and treatment, the precise relationship between inflammation and cardiovascular (CV) disease remains incompletely understood. Therefore, understanding the immunoinflammatory processes underlying the initiation, progression, and exacerbation of many cardiovascular diseases is of prime importance. The innate immune system has an ancient origin and is well conserved across species. Its activation occurs in response to pathogens or tissue injury. Recent studies suggest that altered ionic balance, and production of noxious gaseous mediators link to immune and inflammatory responses with altered ion channel expression and function. Among plausible candidates for this are transient receptor potential (TRP) channels that function as polymodal sensors and scaffolding proteins involved in many physiological and pathological processes. In this review, we will first focus on the relevance of TRP channel to both exogenous and endogenous factors related to innate immune response and transcription factors related to sustained inflammatory status. The emerging role of inflammasome to regulate innate immunity and its possible connection to TRP channels will also be discussed. Secondly, we will discuss about the linkage of TRP channels to inflammatory CV diseases, from a viewpoint of inflammation in a general sense which is not restricted to the innate immunity. These knowledge may serve to provide new insights into the pathogenesis of various inflammatory CV diseases and their novel therapeutic strategies.
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Sun Y, Birnbaumer L, Singh BB. TRPC1 regulates calcium-activated chloride channels in salivary gland cells. J Cell Physiol 2015; 230:2848-56. [PMID: 25899321 PMCID: PMC4872598 DOI: 10.1002/jcp.25017] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 04/14/2015] [Indexed: 12/19/2022]
Abstract
Calcium-activated chloride channel (CaCC) plays an important role in modulating epithelial secretion. It has been suggested that in salivary tissues, sustained fluid secretion is dependent on Ca(2+) influx that activates ion channels such as CaCC to initiate Cl(-) efflux. However direct evidence as well as the molecular identity of the Ca(2+) channel responsible for activating CaCC in salivary tissues is not yet identified. Here we provide evidence that in human salivary cells, an outward rectifying Cl(-) current was activated by increasing [Ca(2+)]i, which was inhibited by the addition of pharmacological agents niflumic acid (NFA), an antagonist of CaCC, or T16Ainh-A01, a specific TMEM16a inhibitor. Addition of thapsigargin (Tg), that induces store-depletion and activates TRPC1-mediated Ca(2+) entry, potentiated the Cl(-) current, which was inhibited by the addition of a non-specific TRPC channel blocker SKF96365 or removal of external Ca(2+). Stimulation with Tg also increased plasma membrane expression of TMEM16a protein, which was also dependent on Ca(2+) entry. Importantly, in salivary cells, TRPC1 silencing, but not that of TRPC3, inhibited CaCC especially upon store depletion. Moreover, primary acinar cells isolated from submandibular gland also showed outward rectifying Cl(-) currents upon increasing [Ca(2+)]i. These Cl(-) currents were again potentiated with the addition of Tg, but inhibited in the presence of T16Ainh-A01. Finally, acinar cells isolated from the submandibular glands of TRPC1 knockout mice showed significant inhibition of the outward Cl(-) currents without decreasing TMEM16a expression. Together the data suggests that Ca(2+) entry via the TRPC1 channels is essential for the activation of CaCC.
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Affiliation(s)
- Yuyang Sun
- Department of Basic Sciences, School of Medicine Health Sciences, University of North Dakota, Grand Forks, North Dakota
| | - Lutz Birnbaumer
- Laboratory of Signal Transduction, NIHES, NIH, Research Triangle Park, North Carolina
| | - Brij B Singh
- Department of Basic Sciences, School of Medicine Health Sciences, University of North Dakota, Grand Forks, North Dakota
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Déliot N, Constantin B. Plasma membrane calcium channels in cancer: Alterations and consequences for cell proliferation and migration. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1848:2512-22. [DOI: 10.1016/j.bbamem.2015.06.009] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 05/20/2015] [Accepted: 06/02/2015] [Indexed: 12/23/2022]
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Luo Y, She DL, Xiong H, Fu SJ, Yang L. The Prognostic Effect of Statin Use on Urologic Cancers: An Updated Meta-Analysis of 35 Observational Studies. Medicine (Baltimore) 2015; 94:e1523. [PMID: 26356727 PMCID: PMC4616645 DOI: 10.1097/md.0000000000001523] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Recent studies suggest that statin may benefit cancer prognosis, especially through its radiosensitization effect. But controversy exists in other studies. Hence, we performed a meta-analysis of results from 35 studies to evaluate the effect of statin use on urologic cancers.We conducted computerized search from PubMed, Embase, and ISI Web of Knowledge through May 2015, screened the retrieved references, and collected and evaluated relevant information. We extracted and synthesized corresponding hazard ratios (HR) and confidence interval (CI) by using Review Manager 5.3 and STATA 13. This review was registered at PROSPERO with registration No. CRD42015020171.We selected total 35 retrospective studies and conducted a meta-analysis of results from these studies. The pooled results suggested no benefit of statin use to bladder cancer and renal cell carcinoma, except overall survival [HR = 0.81, 95% CI: 0.69-0.96]. However, significant improvement of prostate cancer prognosis including overall survival [HR = 0.82, 95% CI: 0.70-0.97] and cancer-specific survival [HR = 0.70, 95% CI: 0.59-0.83] was indicated, but not including tumor progression [HR = 0.84, 95% CI: 0.62-1.14]. Statin use improved biochemical recurrence of prostate cancer in radiotherapy patients [HR = 0.68, 95% CI: 0.54-0.85] but not in radical prostatectomy patients [HR = 0.97, 95% CI: 0.82-1.15].Current evidence suggests no benefit of statin use to bladder cancer and renal cell carcinoma, except in overall survival. While statin use benefited prostate cancer patients in overall survival, cancer-specific survival but not in tumor progression; it also improved biochemical recurrence in radiotherapy patients but not in radical patients. To verify these results, randomized controlled trials are necessary.
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Affiliation(s)
- You Luo
- From the Institute of Gansu Nephro-Urological Clinical Center, Institute of Urology, Department of Urology, Key Laboratory of Urological Disease of Gansu Province, Lanzhou University Second Hospital, Lanzhou, P.R. China (YL, D-LS, HX, S-JF, LY)
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Abstract
Calcium (Ca2+) and magnesium (Mg2+) ions have been shown to play an important role in regulating various neuronal functions. In the present review we focus on the emerging role of transient potential melastatin-7 (TRPM7) channel in not only regulating Ca2+ and Mg2+ homeostasis necessary for biological functions, but also how alterations in TRPM7 function/expression could induce neurodegeneration. Although eight TRPM channels have been identified, the channel properties, mode of activation, and physiological responses of various TRPM channels are quite distinct. Among the known 8 TRPM channels only TRPM6 and TRPM7 channels are highly permeable to both Ca2+ and Mg2+; however here we will only focus on TRPM7 as unlike TRPM6, TRPM7 channels are abundantly expressed in neuronal cells. Importantly, the discrepancy in TRPM7 channel function and expression leads to various neuronal diseases such as Alzheimer disease (AD) and Parkinson disease (PD). Further, it is emerging as a key factor in anoxic neuronal death and in other neurodegenerative disorders. Thus, by understanding the precise involvement of the TRPM7 channels in different neurodegenerative diseases and by understanding the factors that regulate TRPM7 channels, we could uncover new strategies in the future that could evolve as new drug therapeutic targets for effective treatment of these neurodegenerative diseases.
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Affiliation(s)
- Yuyang Sun
- a Department of Basic Science ; School of Medicine and Health Sciences, University of North Dakota ; Grand Forks , ND USA
| | - Pramod Sukumaran
- a Department of Basic Science ; School of Medicine and Health Sciences, University of North Dakota ; Grand Forks , ND USA
| | - Anne Schaar
- a Department of Basic Science ; School of Medicine and Health Sciences, University of North Dakota ; Grand Forks , ND USA
| | - Brij B Singh
- a Department of Basic Science ; School of Medicine and Health Sciences, University of North Dakota ; Grand Forks , ND USA
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Inhibition of TRPM7 Attenuates Rat Aortic Smooth Muscle Cell Proliferation Induced by Angiotensin II. J Cardiovasc Pharmacol 2015; 66:16-24. [DOI: 10.1097/fjc.0000000000000238] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Xu T, Wu BM, Yao HW, Meng XM, Huang C, Ni MM, Li J. Novel insights into TRPM7 function in fibrotic diseases: a potential therapeutic target. J Cell Physiol 2015; 230:1163-9. [PMID: 25204892 DOI: 10.1002/jcp.24801] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2014] [Accepted: 09/05/2014] [Indexed: 12/13/2022]
Abstract
"Transient receptor potential (TRP) channels are cellular sensors for a wide spectrum of physical and chemical stimuli. Activation of TRP channels changes the membrane potential, translocates important signaling ions crossing the cell membrane, alters enzymatic activity, and initiates endocytosis/exocytosis (Zheng, 2013)." Fibrosis is the leading cause of organ dysfunction in diseases, which is characterized by an imbalance in the turnover of extracellular matrix components. Accumulating evidence has demonstrated that TRPM7, a member of TRP channels superfamily, participates in the development and pathogenesis of fibrotic diseases, such as hepatic, pulmonary and cardiac fibrosis. In this review, we discuss the comprehensive role of TRPM7 in modulating profibrotic response and its potential as therapeutic target for fibrotic diseases.
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Affiliation(s)
- Tao Xu
- School of Pharmacy, Anhui Key Laboratory of Bioactivity of Natural Products, Anhui Medical University, Hefei, China; Institute for Liver Diseases of Anhui Medical University, Anhui Medical University, Hefei, China
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Zeng Z, Leng T, Feng X, Sun H, Inoue K, Zhu L, Xiong ZG. Silencing TRPM7 in mouse cortical astrocytes impairs cell proliferation and migration via ERK and JNK signaling pathways. PLoS One 2015; 10:e0119912. [PMID: 25799367 PMCID: PMC4370640 DOI: 10.1371/journal.pone.0119912] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Accepted: 01/17/2015] [Indexed: 11/18/2022] Open
Abstract
Transient receptor potential melastatin 7 (TRPM7), a non-selective cation channel, is highly expressed expressed in the brain and plays a critical role in ischemic neuronal death. Astrocyte, the most abundant cell type in central nervous system (CNS), exerts many essential functions in the physiological and pathological conditions. Here we investigated the expression and functions of the TRPM7 channel in mouse cortical astrocytes. Using reverse transcription (RT)-PCR, immunostaining, western blot and patch clamp recording, we showed that functional TRPM7 channel is expressed in cultured mouse cortical astrocytes. Knocking down TRPM7 with specific siRNA impairs the proliferation and migration of astrocytes by 40.2% ± 3.9% and 40.1% ± 11.5%, respectively. Consistently, inhibition of TRPM7 with 2-aminoethoxydiphenyl borate (2-APB) also decreases astrocyte proliferation and migration by 46.1% ± 2.5% and 64.2% ± 2.4%. MAPKs and Akt signaling pathways have been shown to be implicated in TRPM7-mediated responses including cell proliferation and migration. Our data show that suppression of TRPM7 in astrocytes reduces the phosphorylation of extracellular signal-regulated kinases (ERK) and c-Jun N-terminal kinases (JNK), but not p38 mitogen-activated protein kinase and Akt. In addition, TRPM7, as a cation channel, has been involved in the Ca²⁺ and Mg²⁺ homeostasis in several types of cells. In our study, we found that silencing TRPM7 decreases the intracellular basal Mg²⁺ concentration without affecting Ca²⁺ concentration in astrocytes. However, an addition of Mg²⁺ to the growth medium could not rescue the impaired proliferation of astrocytes. Together, our data suggest that TRPM7 channel may play a critical role in the proliferation and migration of astrocytes via the ERK and JNK pathways.
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Affiliation(s)
- Zhao Zeng
- Cyrus Tang Hematology center, Collaborative Innovation Center of Hematology, MOH Key Lab of Thrombosis and Hemostasis, Jiangsu Key Lab of Preventive and translational Medicine for Geriatric Diseases, Soochow University, Suzhou, Jiangsu, China
| | - Tiandong Leng
- Neuroscience Institute, Morehouse School of Medicine, Atlanta, GA, United States of America
| | - Xuechao Feng
- Membrane Channel Research Laboratory and Key Laboratory for Applied Statistics of MOE, Northeast Normal University, Changchun, P.R. China
| | - Huawei Sun
- Department of Cardiology, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Koichi Inoue
- Neuroscience Institute, Morehouse School of Medicine, Atlanta, GA, United States of America
| | - Li Zhu
- Cyrus Tang Hematology center, Collaborative Innovation Center of Hematology, MOH Key Lab of Thrombosis and Hemostasis, Jiangsu Key Lab of Preventive and translational Medicine for Geriatric Diseases, Soochow University, Suzhou, Jiangsu, China
- * E-mail: ; (LZ); (ZGX)
| | - Zhi-Gang Xiong
- Neuroscience Institute, Morehouse School of Medicine, Atlanta, GA, United States of America
- * E-mail: ; (LZ); (ZGX)
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Sukumaran P, Sun Y, Vyas M, Singh BB. TRPC1-mediated Ca²⁺ entry is essential for the regulation of hypoxia and nutrient depletion-dependent autophagy. Cell Death Dis 2015; 6:e1674. [PMID: 25741599 PMCID: PMC4385947 DOI: 10.1038/cddis.2015.7] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 12/04/2014] [Accepted: 12/29/2014] [Indexed: 02/06/2023]
Abstract
Autophagy is a cellular catabolic process needed for the degradation and recycling of protein aggregates and damaged organelles. Although Ca2+ is suggested to have an important role in cell survival, the ion channel(s) involved in autophagy have not been identified. Here we demonstrate that increase in intracellular Ca2+ via transient receptor potential canonical channel-1 (TRPC1) regulates autophagy, thereby preventing cell death in two morphologically distinct cells lines. The addition of DMOG or DFO, a cell permeable hypoxia-mimetic agents, or serum starvation, induces autophagy in both epithelial and neuronal cells. The induction of autophagy increases Ca2+ entry via the TRPC1 channel, which was inhibited by the addition of 2APB and SKF96365. Importantly, TRPC1-mediated Ca2+ entry resulted in increased expression of autophagic markers that prevented cell death. Furthermore, hypoxia-mediated autophagy also increased TRPC1, but not STIM1 or Orai1, expression. Silencing of TRPC1 or inhibition of autophagy by 3-methyladenine, but not TRPC3, attenuated hypoxia-induced increase in intracellular Ca2+ influx, decreased autophagy, and increased cell death. Furthermore, the primary salivary gland cells isolated from mice exposed to hypoxic conditions also showed increased expression of TRPC1 as well as increase in Ca2+ entry along with increased expression of autophagic markers. Altogether, we provide evidence for the involvement of Ca2+ influx via TRPC1 in regulating autophagy to protect against cell death.
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Affiliation(s)
- P Sukumaran
- Department of Basic Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58201, USA
| | - Y Sun
- Department of Basic Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58201, USA
| | - M Vyas
- Department of Basic Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58201, USA
| | - B B Singh
- Department of Basic Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58201, USA
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Lin PH, Aronson W, Freedland SJ. Nutrition, dietary interventions and prostate cancer: the latest evidence. BMC Med 2015; 13:3. [PMID: 25573005 PMCID: PMC4286914 DOI: 10.1186/s12916-014-0234-y] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Accepted: 11/11/2014] [Indexed: 02/06/2023] Open
Abstract
Prostate cancer (PCa) remains a leading cause of mortality in US men and the prevalence continues to rise world-wide especially in countries where men consume a 'Western-style' diet. Epidemiologic, preclinical and clinical studies suggest a potential role for dietary intake on the incidence and progression of PCa. 'This minireview provides an overview of recent published literature with regard to nutrients, dietary factors, dietary patterns and PCa incidence and progression. Low carbohydrates intake, soy protein, omega-3 (w-3) fat, green teas, tomatoes and tomato products and zyflamend showed promise in reducing PCa risk or progression. A higher saturated fat intake and a higher β-carotene status may increase risk. A 'U' shape relationship may exist between folate, vitamin C, vitamin D and calcium with PCa risk. Despite the inconsistent and inconclusive findings, the potential for a role of dietary intake for the prevention and treatment of PCa is promising. The combination of all the beneficial factors for PCa risk reduction in a healthy dietary pattern may be the best dietary advice. This pattern includes rich fruits and vegetables, reduced refined carbohydrates, total and saturated fats, and reduced cooked meats. Further carefully designed prospective trials are warranted.
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Affiliation(s)
- Pao-Hwa Lin
- Department of Medicine, Division of Nephrology, Duke University Medical Center, Box 3487, Durham, NC 27710 USA
| | - William Aronson
- Urology Section, Department of Surgery, Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA USA
- Department of Urology, UCLA School of Medicine, Los Angeles, CA USA
| | - Stephen J Freedland
- Urology Section, Department of Surgery, Durham Veterans Affairs Medical Center, Division of Urology, Durham, NC USA
- Duke Prostate Center, Departments of Surgery and Pathology, Duke University Medical Center, Durham, NC USA
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Leng TD, Li MH, Shen JF, Liu ML, Li XB, Sun HW, Branigan D, Zeng Z, Si HF, Li J, Chen J, Xiong ZG. Suppression of TRPM7 inhibits proliferation, migration, and invasion of malignant human glioma cells. CNS Neurosci Ther 2014; 21:252-61. [PMID: 25438992 DOI: 10.1111/cns.12354] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 10/15/2014] [Accepted: 10/20/2014] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Glioblastoma multiforme (GBM) is the most common and aggressive primary brain tumor with a dismal prognosis. Despite intensive study on tumor biology, the underlying mechanisms of the unlimited proliferation and progressive local invasion are still poorly understood, and no effective treatment has been developed for GBM patients. AIMS We determine the role of TRPM7 channels in the growth, migration, and infiltration of malignant glioma cells. METHODS Using a combination of RT-PCR, Western blot, and patch-clamp techniques, we demonstrated the expression of functional TRPM7 channels of A172 cells, a human glioma cell line, as well as in human glioma tissues. Furthermore, we evaluated the role of TRPM7 in growth, migration, and infiltration of A172 cells with MTT and transwell migration and invasion assays. RESULTS We showed the expression of functional TRPM7 channels in both A172 cells and human glioma tissues. Suppression of TRPM7 expression with TRPM7-siRNA dramatically reduced the proliferation, migration, and invasion of A172 cells. Pharmacological inhibition of TRPM7 channel with 2-aminoethoxydiphenyl borate (2-APB) showed a similar effect as TRPM7-siRNA. CONCLUSION We demonstrate that human glioma cells express functional TRPM7 channel and that activation of this channel plays an important role in the proliferation, migration, and invasion of malignant glioma cells. TRPM7 channel may represent a novel and promising target for therapeutic intervention of malignant glioma.
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Affiliation(s)
- Tian-Dong Leng
- Neuroscience Institute, Morehouse School of Medicine, Atlanta, GA, USA
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