1
|
Kang KA, Piao MJ, Fernando PDSM, Herath HMUL, Yi JM, Choi YH, Hyun YM, Zhang K, Park CO, Hyun JW. Particulate matter stimulates the NADPH oxidase system via AhR-mediated epigenetic modifications. Environ Pollut 2024; 347:123675. [PMID: 38447650 DOI: 10.1016/j.envpol.2024.123675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 02/05/2024] [Accepted: 02/27/2024] [Indexed: 03/08/2024]
Abstract
Stimulation of human keratinocytes with particulate matter 2.5 (PM2.5) elicits complex signaling events, including a rise in the generation of reactive oxygen species (ROS). However, the mechanisms underlying PM2.5-induced ROS production remain unknown. Here, we show that PM2.5-induced ROS production in human keratinocytes is mediated via the NADPH oxidase (NOXs) system and the Ca2+ signaling pathway. PM2.5 treatment increased the expression of NOX1, NOX4, and a calcium-sensitive NOX, dual oxidase 1 (DUOX1), in human epidermal keratinocyte cell line. PM2.5 bound to aryl hydrocarbon receptor (AhR), and this complex bound to promoter regions of NOX1 and DUOX1, suggesting that AhR acted as a transcription factor of NOX1 and DUOX1. PM2.5 increased the transcription of DUOX1 via epigenetic modification. Moreover, a link between DNA demethylase and histone methyltransferase with the promoter regions of DUOX1 led to an elevation in the expression of DUOX1 mRNA. Interestingly, PM2.5 increased NOX4 expression and promoted the interaction of NOX4 and Ca2+ channels within the cytoplasmic membrane or endoplasmic reticulum, leading to Ca2+ release. The increase in intracellular Ca2+ concentration activated DUOX1, responsible for ROS production. Our findings provide evidence for a PM2.5-mediated ROS-generating system network, in which increased NOX1, NOX4, and DUOX1 expression serves as a ROS signal through AhR and Ca2+ activation.
Collapse
Affiliation(s)
- Kyoung Ah Kang
- Department of Biochemistry, College of Medicine, and Jeju Research Center for Natural Medicine, Jeju National University, Jeju, 63243, South Korea
| | - Mei Jing Piao
- Department of Biochemistry, College of Medicine, and Jeju Research Center for Natural Medicine, Jeju National University, Jeju, 63243, South Korea
| | | | | | - Joo Mi Yi
- Department of Microbiology and Immunology, Inje University College of Medicine, Busan, 47392, South Korea
| | - Yung Hyun Choi
- Department of Biochemistry, College of Oriental Medicine, Dongeui University, Busan, 47340, South Korea
| | - Young-Min Hyun
- Department of Anatomy, Yonsei University College of Medicine, Seoul, 03722, South Korea
| | - Kelun Zhang
- Department of Dermatology, and Cutaneous Biology Research Institute, Yonsei University College of Medicine, Seoul, 03722, South Korea
| | - Chang Ook Park
- Department of Dermatology, and Cutaneous Biology Research Institute, Yonsei University College of Medicine, Seoul, 03722, South Korea
| | - Jin Won Hyun
- Department of Biochemistry, College of Medicine, and Jeju Research Center for Natural Medicine, Jeju National University, Jeju, 63243, South Korea.
| |
Collapse
|
2
|
Hong SY, Yang YY, Wang SG, Qin BL. Inhibition of AT1R/IP3/IP3R-mediated Ca 2+ release protects against calcium oxalate crystals-induced renal oxidative stress. Chem Biol Interact 2023; 382:110636. [PMID: 37454925 DOI: 10.1016/j.cbi.2023.110636] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 07/11/2023] [Accepted: 07/14/2023] [Indexed: 07/18/2023]
Abstract
Calcium oxalate (CaOx) stones are the most prevalent type of kidney stones. CaOx crystals can stimulate reactive oxygen species (ROS) generation and induce renal oxidative stress to promote stone formation. Intracellular Ca2+ is an important signaling molecule, and an elevation of cytoplasmic Ca2+ levels could trigger oxidative stress. Our previous study has revealed that upregulation of Ang II/AT1R promoted renal oxidative stress during CaOx exposure. IP3/IP3R/Ca2+ signaling pathway activated via Ang II/AT1R is involved in several diseases, but its role in stone formation has not been reported. Herein, we focus on the role of AT1R/IP3/IP3R-mediated Ca2+ release in CaOx crystals-induced oxidative stress and explore whether inhibition of this pathway could alleviate renal oxidative stress. NRK-52E cells were exposed to CaOx crystals pretreated with AT1R inhibitor losartan or IP3R inhibitor 2-APB, and glyoxylic acid monohydrate-induced CaOx stone-forming rats were treated with losartan or 2-APB. The intracellular Ca2+ levels, ROS levels, oxidative stress indexes, and the gene expression of this pathway were detected. Our results showed that CaOx crystals activated AT1R to promote IP3/IP3R-mediated Ca2+ release, leading to increased cytoplasmic Ca2+ levels. The Ca2+ elevation was able to stimulate NOX2 and NOX4 to generate ROS, induce oxidative stress, and upregulate the expression of stone-related proteins. 2-APB and losartan reversed the referred effects, reduced CaOx crystals deposition and alleviated tissue injury in the rat kidneys. In summary, our results indicated that CaOx crystals promoted renal oxidative stress by activating the AT1R/IP3/IP3R/Ca2+ pathway. Inhibition of AT1R/IP3/IP3R-mediated Ca2+ release protected against CaOx crystals-induced renal oxidative stress. 2-APB and losartan might be promising preventive and therapeutic agents for the treatment of kidney stone disease.
Collapse
Affiliation(s)
- Sen-Yuan Hong
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
| | - Yuan-Yuan Yang
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
| | - Shao-Gang Wang
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
| | - Bao-Long Qin
- Department of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
| |
Collapse
|
3
|
Mokelke EA, Alloosh M, Sturek M. Specificity of Ca(2+)-activated K(+) channel modulation in atherosclerosis and aerobic exercise training. Curr Top Membr 2022; 90:123-39. [PMID: 36368871 DOI: 10.1016/bs.ctm.2022.09.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Vascular smooth muscle cells express several isoforms of a number of classes of K+ channels. Potassium channels play critical roles in the regulation of vascular smooth muscle contraction as well as vascular smooth muscle cell proliferation or phenotypic modulation. There is ample evidence that it is Ca2+ that enables these two seemingly disparate functions to be tightly coupled both in healthy and disease processes. Because of the central position that potassium channels have in vasocontraction, vasorelaxation, membrane potential, and smooth muscle cell proliferation, these channels continue to possess the potential to serve as novel therapeutic targets in cardiovascular disease. While there are questions that remain regarding the complete interactions between K+ channels, vascular regulation, smooth muscle cell proliferation, and phenotypic modulation in physiological and pathophysiological conditions, a broad understanding of the contributions of each class of K+ channel to contractile and proliferative states of the vasculature has been reached. This brief review will discuss the current understanding of the role of K+ channels in vascular smooth muscle cells in health and disease using the porcine vascular smooth muscle cell model with particular attention to new scientific discoveries contributed by the authors regarding the effect of endurance exercise on the function of the K+ channels.
Collapse
|
4
|
Badin J, Rodenbeck S, McKenney-Drake ML, Sturek M. Multiphasic changes in smooth muscle Ca 2+ transporters during the progression of coronary atherosclerosis. Curr Top Membr 2022; 90:95-121. [PMID: 36368876 DOI: 10.1016/bs.ctm.2022.09.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Ischemic heart disease due to macrovascular atherosclerosis and microvascular dysfunction is the major cause of death worldwide and the unabated increase in metabolic syndrome is a major reason why this will continue. Intracellular free Ca2+ ([Ca2+]i) regulates a variety of cellular functions including contraction, proliferation, migration, and transcription. It follows that studies of vascular Ca2+ regulation in reductionist models and translational animal models are vital to understanding vascular health and disease. Swine with metabolic syndrome (MetS) develop the full range of coronary atherosclerosis from mild to severe disease. Intravascular imaging enables quantitative measurement of atherosclerosis in vivo, so viable coronary smooth muscle (CSM) cells can be dispersed from the arteries to enable Ca2+ transport studies in native cells. Transition of CSM from the contractile phenotype in the healthy swine to the proliferative phenotype in mild atherosclerosis was associated with increases in SERCA activity, sarcoplasmic reticulum Ca2+, and voltage-gated Ca2+ channel function. In vitro organ culture confirmed that SERCA activation induces CSM proliferation. Transition from the proliferative to a more osteogenic phenotype was associated with decreases in all three Ca2+ transporters. Overall, there was a biphasic change in Ca2+ transporters over the progression of atherosclerosis in the swine model and this was confirmed in CSM from failing explanted hearts of humans. A major determinant of endolysosome content in human CSM is the severity of atherosclerosis. In swine CSM endolysosome Ca2+ release occurred through the TPC2 channel. We propose a multiphasic change in Ca2+ transporters over the progression of coronary atherosclerosis.
Collapse
Affiliation(s)
- Jill Badin
- ZOLL Medical Corporation, Chelmsford, MA, United States
| | - Stacey Rodenbeck
- Department of Biology, Harding University, Searcy, AR, United States
| | - Mikaela L McKenney-Drake
- Butler University, Health Sciences Department, Pharmacy and Health Sciences, Indianapolis, IN, United States
| | - Michael Sturek
- Department of Anatomy, Cell Biology, & Physiology, Indiana University School of Medicine, Indianapolis, IN, United States.
| |
Collapse
|
5
|
Liu H, Cheng Y, Chu J, Wu M, Yan M, Wang D, Xie Q, Ali F, Fang Y, Wei L, Yang Y, Shen A, Peng J. Baicalin attenuates angiotensin II-induced blood pressure elevation and modulates MLCK/p-MLC signaling pathway. Biomed Pharmacother 2021; 143:112124. [PMID: 34492423 DOI: 10.1016/j.biopha.2021.112124] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 08/18/2021] [Accepted: 08/24/2021] [Indexed: 01/05/2023] Open
Abstract
Scutellaria baicalensis Georgi is an extensively used medicinal herb for the treatment of hypertension in traditional Chinese medicine. Baicalin, is an important flavonoid in Scutellaria baicalensis Georgi extracts, which exhibits therapeutic effects on anti-hypertension, but its underlying mechanisms remain to be further explored. Therefore, we investigated the effects and molecular mechanisms of Baicalin on anti-hypertension. In vivo studies revealed that Baicalin treatment significantly attenuated the elevation in blood pressure, the pulse propagation and thickening of the abdominal aortic wall in C57BL/6 mice infused with Angiotensin II (Ang II). Moreover, RNA-sequencing and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses identified 537 differentially expressed transcripts and multiple enriched signaling pathways (including vascular smooth muscle contraction and calcium signaling pathway). Consistently, we found that Baicalin pretreatment significantly alleviated the Ang II induced constriction of abdominal aortic ring, while promoted NE pre-contracted vasodilation of abdominal aortic ring at least partly dependent on L-type calcium channel. In addition, Ang II stimulation significantly increased cell viability and PCNA expression, while were attenuated after Baicalin treatment. Moreover, Baicalin pretreatment attenuated Ang II-induced intracellular Ca2+ release, Angiotensin II type 1 receptor (AT1R) expression and activation of MLCK/p-MLC pathway in vascular smooth muscle cells (VSMCs). The present work further addressed the pharmacological and mechanistic insights on anti-hypertension of Baicalin, which may help better understand the therapeutic effect of Scutellaria baicalensis Georgi on anti-hypertension.
Collapse
MESH Headings
- Angiotensin II
- Animals
- Aorta, Abdominal/drug effects
- Aorta, Abdominal/enzymology
- Aorta, Abdominal/physiopathology
- Blood Pressure/drug effects
- Calcium Signaling/drug effects
- Cell Proliferation/drug effects
- Cells, Cultured
- Disease Models, Animal
- Flavonoids/pharmacology
- Hypertension/chemically induced
- Hypertension/enzymology
- Hypertension/physiopathology
- Hypertension/prevention & control
- Hypoglycemic Agents/pharmacology
- Male
- Mice, Inbred C57BL
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/enzymology
- Muscle, Smooth, Vascular/physiopathology
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/enzymology
- Myosin Light Chains/metabolism
- Myosin-Light-Chain Kinase/metabolism
- Phosphorylation
- Rats, Wistar
- Mice
- Rats
Collapse
Affiliation(s)
- Huixin Liu
- Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China; Fujian Key Laboratory of Integrative Medicine on Geriatrics, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China; Chen Keji Academic Thought Inheritance Studio, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China
| | - Ying Cheng
- Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China; Fujian Key Laboratory of Integrative Medicine on Geriatrics, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China
| | - Jianfeng Chu
- Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China; Fujian Key Laboratory of Integrative Medicine on Geriatrics, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China; Chen Keji Academic Thought Inheritance Studio, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China
| | - Meizhu Wu
- Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China; Fujian Key Laboratory of Integrative Medicine on Geriatrics, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China; Chen Keji Academic Thought Inheritance Studio, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China
| | - Mengchao Yan
- Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China; Fujian Key Laboratory of Integrative Medicine on Geriatrics, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China; Chen Keji Academic Thought Inheritance Studio, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China
| | - Di Wang
- Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China; Fujian Key Laboratory of Integrative Medicine on Geriatrics, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China; Chen Keji Academic Thought Inheritance Studio, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China
| | - Qiurong Xie
- Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China; Fujian Key Laboratory of Integrative Medicine on Geriatrics, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China; Chen Keji Academic Thought Inheritance Studio, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China
| | - Farman Ali
- Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China; Fujian Key Laboratory of Integrative Medicine on Geriatrics, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China; Chen Keji Academic Thought Inheritance Studio, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China
| | - Yi Fang
- Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China; Fujian Key Laboratory of Integrative Medicine on Geriatrics, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China; Chen Keji Academic Thought Inheritance Studio, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China
| | - Lihui Wei
- Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China; Fujian Key Laboratory of Integrative Medicine on Geriatrics, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China; Chen Keji Academic Thought Inheritance Studio, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China
| | - Yanyan Yang
- Laboratory Animal Center, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China
| | - Aling Shen
- Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China; Fujian Key Laboratory of Integrative Medicine on Geriatrics, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China; Chen Keji Academic Thought Inheritance Studio, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China.
| | - Jun Peng
- Academy of Integrative Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China; Fujian Key Laboratory of Integrative Medicine on Geriatrics, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China; Chen Keji Academic Thought Inheritance Studio, Fujian University of Traditional Chinese Medicine, Fuzhou, Fujian 350122, China.
| |
Collapse
|
6
|
Guo W, Wei J, Estillore JP, Zhang L, Wang R, Sun B, Chen SRW. RyR2 disease mutations at the C-terminal domain intersubunit interface alter closed-state stability and channel activation. J Biol Chem 2021; 297:100808. [PMID: 34022226 PMCID: PMC8214192 DOI: 10.1016/j.jbc.2021.100808] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 05/14/2021] [Accepted: 05/18/2021] [Indexed: 11/19/2022] Open
Abstract
Ryanodine receptors (RyRs) are ion channels that mediate the release of Ca2+ from the sarcoplasmic reticulum/endoplasmic reticulum, mutations of which are implicated in a number of human diseases. The adjacent C-terminal domains (CTDs) of cardiac RyR (RyR2) interact with each other to form a ring-like tetrameric structure with the intersubunit interface undergoing dynamic changes during channel gating. This mobile CTD intersubunit interface harbors many disease-associated mutations. However, the mechanisms of action of these mutations and the role of CTD in channel function are not well understood. Here, we assessed the impact of CTD disease-associated mutations P4902S, P4902L, E4950K, and G4955E on Ca2+− and caffeine-mediated activation of RyR2. The G4955E mutation dramatically increased both the Ca2+-independent basal activity and Ca2+-dependent activation of [3H]ryanodine binding to RyR2. The P4902S and E4950K mutations also increased Ca2+ activation but had no effect on the basal activity of RyR2. All four disease mutations increased caffeine-mediated activation of RyR2 and reduced the threshold for activation and termination of spontaneous Ca2+ release. G4955D dramatically increased the basal activity of RyR2, whereas G4955K mutation markedly suppressed channel activity. Similarly, substitution of P4902 with a negatively charged residue (P4902D), but not a positively charged residue (P4902K), also dramatically increased the basal activity of RyR2. These data suggest that electrostatic interactions are involved in stabilizing the CTD intersubunit interface and that the G4955E disease mutation disrupts this interface, and thus the stability of the closed state. Our studies shed new insights into the mechanisms of action of RyR2 CTD disease mutations.
Collapse
Affiliation(s)
- Wenting Guo
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Jinhong Wei
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - John Paul Estillore
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Lin Zhang
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Ruiwu Wang
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada
| | - Bo Sun
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada; Medical School, Kunming University of Science and Technology, Kunming, China.
| | - S R Wayne Chen
- Libin Cardiovascular Institute, Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.
| |
Collapse
|
7
|
Li XQ, Zheng YM, Reyes-García J, Wang YX. Diversity of ryanodine receptor 1-mediated Ca 2+ signaling in systemic and pulmonary artery smooth muscle cells. Life Sci 2021; 270:119016. [PMID: 33515564 DOI: 10.1016/j.lfs.2021.119016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2020] [Revised: 12/26/2020] [Accepted: 01/03/2021] [Indexed: 11/26/2022]
Abstract
AIMS Ryanodine receptor-1 (RyR1) is essential for skeletal muscle cell functions. However, its roles in vascular smooth muscle cells (SMCs) are well recognized. This study aims to determine the potential physiological importance and difference in systemic and pulmonary artery SMCs (SASMCs and PASMCs). METHODS Local and global Ca2+ release were measured using a laser scanning confocal microscope and wide-field fluorescence microscope; membrane currents were recorded using a patch clamp recording; muscle contraction was determined using an organ bath system; RyR protein expression was assessed using immunofluorescence staining. Homozygous and heterozygous RyR1 gene knockout (RyR1-/- and RyR1+/-) mice were used to determine its specific functions. KEY FINDINGS Ca2+ sparks were more prominently decreased in RyR1-/- ASMCs than in PASMCs. Caffeine induced a smaller increase in [Ca2+]i in both RyR1+/+ and RyR1-/- ASMCs than in PASMCs. High K+ produced a reduced [Ca2+]i increase in RyR1-/- PASMCs and ASMCs as well as a reduced contraction in RyR1+/- pulmonary artery and aortic tissues. ATP elicited a smaller increase in [Ca2+]i in RyR1-/- ASMCs and PASMCs with a greater inhibition in ASMCs. Norepinephrine-elicited muscle contraction was reduced in RyR1+/- aortic and pulmonary arteries. IP3 dialysis-induced Ca2+ release was much smaller in RyR1+/- ASMCs and PASMCs. Hypoxia-induced large Ca2+ and contractile responses were inhibited in RyR1+/- PASMCs. However, hypoxic exposure did not evoke a notable increase in [Ca2+]i in ASMCs. SIGNIFICANCE Our findings for the first time provide clear genetic evidence for the functional importance and difference of RyR1 in systemic and pulmonary artery SMCs.
Collapse
Affiliation(s)
- Xiao-Qiang Li
- Albany Medical College, Department of Molecular & Cellular Physiology (MC-8), 47 New Scotland Avenue, Albany, NY 12208, United States of America
| | - Yun-Min Zheng
- Albany Medical College, Department of Molecular & Cellular Physiology (MC-8), 47 New Scotland Avenue, Albany, NY 12208, United States of America
| | - Jorge Reyes-García
- Departamento de Farmacología, Facultad de Medicina, Universidad Nacional Autónoma de México, CDMX, México
| | - Yong-Xiao Wang
- Albany Medical College, Department of Molecular & Cellular Physiology (MC-8), 47 New Scotland Avenue, Albany, NY 12208, United States of America.
| |
Collapse
|
8
|
Cacheux M, Fauconnier J, Thireau J, Osseni A, Brocard J, Roux-Buisson N, Brocard J, Fauré J, Lacampagne A, Marty I. Interplay between Triadin and Calsequestrin in the Pathogenesis of CPVT in the Mouse. Mol Ther 2019; 28:171-179. [PMID: 31607542 DOI: 10.1016/j.ymthe.2019.09.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 08/28/2019] [Accepted: 09/06/2019] [Indexed: 01/07/2023] Open
Abstract
Recessive forms of catecholaminergic polymorphic ventricular tachycardia (CPVT) are induced by mutations in genes encoding triadin or calsequestrin, two proteins that belong to the Ca2+ release complex, responsible for intracellular Ca2+ release triggering cardiac contractions. To better understand the mechanisms of triadin-induced CPVT and to assay multiple therapeutic interventions, we used a triadin knockout mouse model presenting a CPVT-like phenotype associated with a decrease in calsequestrin protein level. We assessed different approaches to rescue protein expression and to correct intracellular Ca2+ release and cardiac function: pharmacological treatment with kifunensine or a viral gene transfer-based approach, using adeno-associated virus serotype 2/9 (AAV2/9) encoding the triadin or calsequestrin. We observed that the levels of triadin and calsequestrin are intimately linked, and that reduction of both proteins contributes to the CPVT phenotype. Different combinations of triadin and calsequestrin expression level were obtained using these therapeutic approaches. A full expression of each is not necessary to correct the phenotype; a fine-tuning of the relative re-expression of both triadin and calsequestrin is required to correct the CPVT phenotype and rescue the cardiac function. AAV-mediated gene delivery of calsequestrin or triadin and treatment with kifunensine are potential treatments for recessive forms of CPVT due to triadin mutations.
Collapse
Affiliation(s)
- Marine Cacheux
- Grenoble Institut Neurosciences, INSERM, Grenoble Alpes University, U1216, CHU Grenoble Alpes, 38700 La Tronche, France
| | - Jérémy Fauconnier
- University of Montpellier, INSERM U1046, CNRS 9214, CHU Montpellier, 34295 Montpellier, France
| | - Jérôme Thireau
- University of Montpellier, INSERM U1046, CNRS 9214, CHU Montpellier, 34295 Montpellier, France
| | - Alexis Osseni
- Grenoble Institut Neurosciences, INSERM, Grenoble Alpes University, U1216, CHU Grenoble Alpes, 38700 La Tronche, France
| | - Jacques Brocard
- Grenoble Institut Neurosciences, INSERM, Grenoble Alpes University, U1216, CHU Grenoble Alpes, 38700 La Tronche, France
| | - Nathalie Roux-Buisson
- Grenoble Institut Neurosciences, INSERM, Grenoble Alpes University, U1216, CHU Grenoble Alpes, 38700 La Tronche, France
| | - Julie Brocard
- Grenoble Institut Neurosciences, INSERM, Grenoble Alpes University, U1216, CHU Grenoble Alpes, 38700 La Tronche, France
| | - Julien Fauré
- Grenoble Institut Neurosciences, INSERM, Grenoble Alpes University, U1216, CHU Grenoble Alpes, 38700 La Tronche, France
| | - Alain Lacampagne
- University of Montpellier, INSERM U1046, CNRS 9214, CHU Montpellier, 34295 Montpellier, France.
| | - Isabelle Marty
- Grenoble Institut Neurosciences, INSERM, Grenoble Alpes University, U1216, CHU Grenoble Alpes, 38700 La Tronche, France.
| |
Collapse
|
9
|
Sahoo N, Gu M, Zhang X, Raval N, Yang J, Bekier M, Calvo R, Patnaik S, Wang W, King G, Samie M, Gao Q, Sahoo S, Sundaresan S, Keeley TM, Wang Y, Marugan J, Ferrer M, Samuelson LC, Merchant JL, Xu H. Gastric Acid Secretion from Parietal Cells Is Mediated by a Ca 2+ Efflux Channel in the Tubulovesicle. Dev Cell 2017; 41:262-273.e6. [PMID: 28486130 DOI: 10.1016/j.devcel.2017.04.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 03/10/2017] [Accepted: 04/03/2017] [Indexed: 12/12/2022]
Abstract
Gastric acid secretion by parietal cells requires trafficking and exocytosis of H/K-ATPase-rich tubulovesicles (TVs) toward apical membranes in response to histamine stimulation via cyclic AMP elevation. Here, we found that TRPML1 (ML1), a protein that is mutated in type IV mucolipidosis (ML-IV), is a tubulovesicular channel essential for TV exocytosis and acid secretion. Whereas ML-IV patients are reportedly achlorhydric, transgenic overexpression of ML1 in mouse parietal cells induced constitutive acid secretion. Gastric acid secretion was blocked and stimulated by ML1 inhibitors and agonists, respectively. Organelle-targeted Ca2+ imaging and direct patch-clamping of apical vacuolar membranes revealed that ML1 mediates a PKA-activated conductance on TV membranes that is required for histamine-induced Ca2+ release from TV stores. Hence, we demonstrated that ML1, acting as a Ca2+ channel in TVs, links transmitter-initiated cyclic nucleotide signaling with Ca2+-dependent TV exocytosis in parietal cells, providing a regulatory mechanism that could be targeted to manage acid-related gastric diseases.
Collapse
Affiliation(s)
- Nirakar Sahoo
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 3089 Natural Science Building (Kraus), 830 North University, Ann Arbor, MI 48109, USA
| | - Mingxue Gu
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 3089 Natural Science Building (Kraus), 830 North University, Ann Arbor, MI 48109, USA
| | - Xiaoli Zhang
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 3089 Natural Science Building (Kraus), 830 North University, Ann Arbor, MI 48109, USA
| | - Neel Raval
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 3089 Natural Science Building (Kraus), 830 North University, Ann Arbor, MI 48109, USA
| | - Junsheng Yang
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 3089 Natural Science Building (Kraus), 830 North University, Ann Arbor, MI 48109, USA; Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, College of Pharmaceutical Sciences, Zhejiang University of Technology, Hangzhou 310014, China
| | - Michael Bekier
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 3089 Natural Science Building (Kraus), 830 North University, Ann Arbor, MI 48109, USA
| | - Raul Calvo
- National Center for Advancing Translational Sciences, National Institute of Health, 9800 Medical Center Drive, Rockville, MD 20850, USA
| | - Samarjit Patnaik
- National Center for Advancing Translational Sciences, National Institute of Health, 9800 Medical Center Drive, Rockville, MD 20850, USA
| | - Wuyang Wang
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 3089 Natural Science Building (Kraus), 830 North University, Ann Arbor, MI 48109, USA
| | - Greyson King
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 3089 Natural Science Building (Kraus), 830 North University, Ann Arbor, MI 48109, USA
| | - Mohammad Samie
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 3089 Natural Science Building (Kraus), 830 North University, Ann Arbor, MI 48109, USA
| | - Qiong Gao
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 3089 Natural Science Building (Kraus), 830 North University, Ann Arbor, MI 48109, USA
| | - Sasmita Sahoo
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 3089 Natural Science Building (Kraus), 830 North University, Ann Arbor, MI 48109, USA
| | - Sinju Sundaresan
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Theresa M Keeley
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Yanzhuang Wang
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 3089 Natural Science Building (Kraus), 830 North University, Ann Arbor, MI 48109, USA
| | - Juan Marugan
- National Center for Advancing Translational Sciences, National Institute of Health, 9800 Medical Center Drive, Rockville, MD 20850, USA
| | - Marc Ferrer
- National Center for Advancing Translational Sciences, National Institute of Health, 9800 Medical Center Drive, Rockville, MD 20850, USA
| | - Linda C Samuelson
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA; Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Juanita L Merchant
- Division of Gastroenterology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Haoxing Xu
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, 3089 Natural Science Building (Kraus), 830 North University, Ann Arbor, MI 48109, USA.
| |
Collapse
|
10
|
Zhao K, Li G, Yao Y, Zhou Y, Li Z, Guo Q, Lu N. Activation of phospholipase C-γ1 and translocation of phosphatidylinositol-3,4,5-trisphosphate 3-phosphatase contribute to GL-V9-induced apoptosis in human gastric cancer cells. Exp Cell Res 2017; 356:8-19. [PMID: 28412247 DOI: 10.1016/j.yexcr.2017.03.063] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 03/29/2017] [Accepted: 03/30/2017] [Indexed: 12/19/2022]
Abstract
Gastric cancer is the most common type of tumor in developing countries and the fourth most frequently diagnosed cancer worldwide. Here, we demonstrated the apoptotic effects of GL-V9 on several human gastric cancer cells and selected MGC-803 cells to uncover the underlying mechanism. GL-V9 elevated Bax/Bcl-2 ratio, abated mitochondrial membrane potential and triggered the onset of apoptotic execution in MGC-803 cells. Our research revealed that CHOP silencing could not inhibit apoptosis, neither could it block Ca2+ release, suggesting that GL-V9-induced apoptosis was independent of CHOP. Furthermore, GL-V9 increased mitochondrial Ca2+ uptake through 1,4,5-triphosphate (IP3) receptor via the activation of phospholipase C-γ1 and the translocation of phosphatidylinositol-3,4,5-trisphosphate 3-phosphatase from nucleus to endoplasmic reticulum. Moreover, in-vivo studies indicated that GL-V9 exhibited significant MGC-803 xenografts regression in nude mice with low systemic toxicity. In conclusion, GL-V9 could induce apoptosis in gastric cancer cells, and would be a promising therapeutical agent against gastric cancer.
Collapse
Affiliation(s)
- Kai Zhao
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, 24 Tongjiaxiang, Nanjing 210009, People's Republic of China
| | - Guojun Li
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, 24 Tongjiaxiang, Nanjing 210009, People's Republic of China
| | - Yuyuan Yao
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, 24 Tongjiaxiang, Nanjing 210009, People's Republic of China
| | - Yuxin Zhou
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, 24 Tongjiaxiang, Nanjing 210009, People's Republic of China
| | - Zhiyu Li
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, 24 Tongjiaxiang, Nanjing 210009, People's Republic of China
| | - Qinglong Guo
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, 24 Tongjiaxiang, Nanjing 210009, People's Republic of China.
| | - Na Lu
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, Jiangsu Key Laboratory of Drug Design and Optimization, China Pharmaceutical University, 24 Tongjiaxiang, Nanjing 210009, People's Republic of China.
| |
Collapse
|
11
|
Potenza DM, Guerra G, Avanzato D, Poletto V, Pareek S, Guido D, Gallanti A, Rosti V, Munaron L, Tanzi F, Moccia F. Hydrogen sulphide triggers VEGF-induced intracellular Ca²⁺ signals in human endothelial cells but not in their immature progenitors. Cell Calcium 2014; 56:225-34. [PMID: 25113159 DOI: 10.1016/j.ceca.2014.07.010] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Revised: 07/09/2014] [Accepted: 07/18/2014] [Indexed: 10/25/2022]
Abstract
Hydrogen sulphide (H2S) is a newly discovered gasotransmitter that regulates multiple steps in VEGF-induced angiogenesis. An increase in intracellular Ca(2+) concentration ([Ca(2+)]i) is central to endothelial proliferation and may be triggered by both VEGF and H2S. Albeit VEGFR-2 might serve as H2S receptor, the mechanistic relationship between VEGF- and H2S-induced Ca(2+) signals in endothelial cells is unclear. The present study aimed at assessing whether and how NaHS, a widely employed H2S donor, stimulates pro-angiogenic Ca(2+) signals in Ea.hy926 cells, a suitable surrogate for mature endothelial cells, and human endothelial progenitor cells (EPCs). We found that NaHS induced a dose-dependent increase in [Ca(2+)]i in Ea.hy926 cells. NaHS-induced Ca(2+) signals in Ea.hy926 cells did not require extracellular Ca(2+) entry, while they were inhibited upon pharmacological blockade of the phospholipase C/inositol-1,4,5-trisphosphate (InsP3) signalling pathway. Moreover, the Ca(2+) response to NaHS was prevented by genistein, but not by SU5416, which selectively inhibits VEGFR-2. However, VEGF-induced Ca(2+) signals were suppressed by dl-propargylglycine (PAG), which blocks the H2S-producing enzyme, cystathionine γ-lyase. Consistent with these data, VEGF-induced proliferation and migration were inhibited by PAG in Ea.hy926 cells, albeit NaHS alone did not influence these processes. Conversely, NaHS elevated [Ca(2+)]i only in a modest fraction of circulating EPCs, whereas neither VEGF-induced Ca(2+) oscillations nor VEGF-dependent proliferation were affected by PAG. Therefore, H2S-evoked elevation in [Ca(2+)]i is essential to trigger the pro-angiogenic Ca(2+) response to VEGF in mature endothelial cells, but not in their immature progenitors.
Collapse
Affiliation(s)
- Duilio Michele Potenza
- Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia, Via Forlanini 6, 27100 Pavia, Italy
| | - Germano Guerra
- Department of Health Sciences, University of Molise, Via F. De Santis, 86100 Campobasso, Italy
| | - Daniele Avanzato
- Department of Life Sciences and Systems Biology, Centre for Nanostructured Interfaces and Surfaces, Centre for Complex Systems in Molecular Biology and Medicine, University of Torino, 10123 Torino, Italy
| | - Valentina Poletto
- Center for the Study of Myelofibrosis, Research Laboratory of Biotechnology, IRCCS Policlinico San Matteo Foundation, Piazzale Golgi 19, 27100 Pavia, Italy
| | - Sumedha Pareek
- Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia, Via Forlanini 6, 27100 Pavia, Italy
| | - Daniele Guido
- Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia, Via Forlanini 6, 27100 Pavia, Italy
| | - Angelo Gallanti
- Department of Molecular Medicine, University of Pavia, Via Taramelli 10, 27100 Pavia, Italy
| | - Vittorio Rosti
- Center for the Study of Myelofibrosis, Research Laboratory of Biotechnology, IRCCS Policlinico San Matteo Foundation, Piazzale Golgi 19, 27100 Pavia, Italy
| | - Luca Munaron
- Department of Life Sciences and Systems Biology, Centre for Nanostructured Interfaces and Surfaces, Centre for Complex Systems in Molecular Biology and Medicine, University of Torino, 10123 Torino, Italy
| | - Franco Tanzi
- Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia, Via Forlanini 6, 27100 Pavia, Italy
| | - Francesco Moccia
- Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia, Via Forlanini 6, 27100 Pavia, Italy.
| |
Collapse
|
12
|
Albarrán L, Dionisio N, López E, Salido GM, Rosado JA. The membrane potential modulates thrombin-stimulated Ca²⁺ mobilization and platelet aggregation. Arch Biochem Biophys 2013; 538:130-7. [PMID: 23988350 DOI: 10.1016/j.abb.2013.08.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Revised: 08/13/2013] [Accepted: 08/18/2013] [Indexed: 11/28/2022]
Abstract
G protein-coupled receptors can be directly modulated by changes in transmembrane voltage in a variety of cell types. Here we show that, while changes in the membrane voltage itself do not induce detectable modifications in the cytosolic Ca(2+) concentration, platelet stimulation with thrombin or the PAR-1 and PAR-4 agonist peptides SFLLRN and AYPGKF, respectively, results in Ca(2+) release from intracellular stores that is sensitive to the membrane depolarisation. Direct activation of G proteins or phospholipase C by AlF4(-) and m-3M3FBS, respectively, leads to Ca(2+) release that is insensitive to changes in the membrane potential. Thapsigargin-, as well as OAG-induced Ca(2+) entry are affected by the membrane voltage, probably as a result of the modification in the driving force for Ca(2+) influx; however, hyperpolarisation does not enhance thrombin- or OAG-evoked Ca(2+) entry probably revealing the presence of a voltage-sensitive regulatory mechanism. Transmembrane voltage also modulates the activity of the plasma membrane Ca(2+)-ATPase (PMCA) most likely due to a decrease in the phosphotyrosine content of the pump. Thrombin-stimulated platelet aggregation is modulated by membrane depolarisation by a mechanism that is, at least partially, independent of Ca(2+). These observations indicate that PAR-1 and PAR-4 receptors are modulated by the membrane voltage in human platelets.
Collapse
Affiliation(s)
- Letizia Albarrán
- Department of Physiology (Cell Physiology Research Group), University of Extremadura, 10003 Cáceres, Spain
| | | | | | | | | |
Collapse
|
13
|
Wang P, Wu Y, Li Y, Zheng J, Tang J. A novel RING finger E3 ligase RNF186 regulate ER stress-mediated apoptosis through interaction with BNip1. Cell Signal 2013; 25:2320-33. [PMID: 23896122 DOI: 10.1016/j.cellsig.2013.07.016] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Revised: 07/04/2013] [Accepted: 07/22/2013] [Indexed: 01/08/2023]
Abstract
Disturbances in the normal functions of the endoplasmic reticulum (ER) can lead to the accumulation of unfolded proteins and disturbance of Ca(2+) regulation within the lumen of ER, and arouse a series of complicated response termed unfolded protein response (UPR), which is aimed initially at reestablishing homeostasis and normal physiology but can ultimately trigger cell death if the UPR fails to compensate for damage. Here we show that ER locating human RING finger E3 ligase RNF186 participates in the process of ER stress-mediated apoptosis. Overexpression of RNF186 stimulates upregulation of ER sensor proteins and rapid transmission of ER Ca(2+) in Hela cells, while RNF186 knockdown exhibits a moderate degree of resistance to ER stress, indicating RNF186 can arouse stress signaling at ER. We further identified the Bcl-2 family protein BNip1 as one of the substrates of RNF186. BNip1 co-localizes with RNF186 at ER and is poly-ubiquitinated by RNF186 through K29 and K63 linkage in vivo. This modification promotes BNip1 transportation to mitochondria but has no influence on its protein level. The half-life of RNF186 is prolonged under ER stress, probably because of the inhibition on its self-ubiquitination and subsequent degradation by proteasomes. In addition, the ubiquitination of BNip1 is greatly enhanced when ER stress occurred, possibly due to RNF186 accumulation. More importantly, knockdown of BNip1 attenuates the stress signals at ER induced by RNF186. These results collectively indicate that BNip1 functions as a downstream modulator of RNF186 to direct ER stress-associated apoptotic signaling. Our study might reveal a novel E3 ligase-mediated mechanism for modulating ER stress.
Collapse
|