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Ma YG, Wang JW, Zhang YB, Wang BF, Dai ZJ, Xie MJ, Kang HF. Salidroside improved cerebrovascular vasodilation in streptozotocin-induced diabetic rats through restoring the function of BKCa channel in smooth muscle cells. Cell Tissue Res 2017; 370:365-377. [DOI: 10.1007/s00441-017-2671-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Accepted: 07/18/2017] [Indexed: 12/16/2022]
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Ma YG, Liu WC, Dong S, Du C, Wang XJ, Li JS, Xie XP, Wu L, Ma DC, Yu ZB, Xie MJ. Activation of BK(Ca) channels in zoledronic acid-induced apoptosis of MDA-MB-231 breast cancer cells. PLoS One 2012; 7:e37451. [PMID: 22655048 PMCID: PMC3360057 DOI: 10.1371/journal.pone.0037451] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2011] [Accepted: 04/20/2012] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Zoledronic acid, one of the most potent nitrogen-containing biphosphonates, has been demonstrated to have direct anti-tumor and anti-metastatic properties in breast cancer in vitro and in vivo. In particular, tumor-cell apoptosis has been recognized to play an important role in the treatment of metastatic breast cancer with zoledronic acid. However, the precise mechanisms remain less clear. In the present study, we investigated the specific role of large conductance Ca(2+)-activated potassium (BK(Ca)) channel in zoledronic acid-induced apoptosis of estrogen receptor (ER)-negative MDA-MB-231 breast cancer cells. METHODOLOGY/PRINCIPAL FINDINGS The action of zoledronic acid on BK(Ca) channel was investigated by whole-cell and cell-attached patch clamp techniques. Cell apoptosis was assessed with immunocytochemistry, analysis of fragmented DNA by agarose gel electrophoresis, and flow cytometry assays. Cell proliferation was investigated by MTT test and immunocytochemistry. In addition, such findings were further confirmed with human embryonic kidney 293 (HEK293) cells which were transfected with functional BK(Ca) α-subunit (hSloα). Our results clearly indicated that zoledronic acid directly increased the activities of BK(Ca) channels, and then activation of BK(Ca) channel by zoledronic acid contributed to induce apoptosis in MDA-MB-231 cells. The possible mechanisms were associated with the elevated level of intracellular Ca(2+) and a concomitant depolarization of mitochondrial membrane potential (Δψm) in MDA-MB-231 cells. CONCLUSIONS Activation of BK(Ca) channel was here shown to be a novel molecular pathway involved in zoledronic acid-induced apoptosis of MDA-MB-231 cells in vitro.
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Affiliation(s)
- Yu-Guang Ma
- Department of Clinical Oncology, Xijing Hospital, Fourth Military Medical University, Xi'an, China
- Department of Breast Disease, First Hospital of Lanzhou University, Lanzhou, China
| | - Wen-Chao Liu
- Department of Clinical Oncology, Xijing Hospital, Fourth Military Medical University, Xi'an, China
- * E-mail: (WCL); (MJX)
| | - Shuo Dong
- Department of Medicine, Baylor College of Medicine, Houston, United States of America
| | - Cheng Du
- Department of Clinical Oncology, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | - Xiao-Jun Wang
- Key Laboratory of Aerospace Medicine, Department of Aerospace Physiology, Fourth Military Medical University, Ministry of China, Xi'an, China
| | - Jin-Sheng Li
- Key Laboratory of Aerospace Medicine, Department of Aerospace Physiology, Fourth Military Medical University, Ministry of China, Xi'an, China
| | - Xiao-Ping Xie
- Key Laboratory of Aerospace Medicine, Department of Aerospace Physiology, Fourth Military Medical University, Ministry of China, Xi'an, China
| | - Li Wu
- Department of Breast Disease, First Hospital of Lanzhou University, Lanzhou, China
| | - Da-Chang Ma
- Department of Breast Disease, First Hospital of Lanzhou University, Lanzhou, China
| | - Zhi-Bin Yu
- Key Laboratory of Aerospace Medicine, Department of Aerospace Physiology, Fourth Military Medical University, Ministry of China, Xi'an, China
| | - Man-Jiang Xie
- Key Laboratory of Aerospace Medicine, Department of Aerospace Physiology, Fourth Military Medical University, Ministry of China, Xi'an, China
- * E-mail: (WCL); (MJX)
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Chang H, Ma YG, Wang YY, Song Z, Li Q, Yang N, Zhao HZ, Feng HZ, Chang YM, Ma J, Yu ZB, Xie MJ. High glucose alters apoptosis and proliferation in HEK293 cells by inhibition of cloned BK Ca channel. J Cell Physiol 2011; 226:1660-75. [PMID: 21413024 DOI: 10.1002/jcp.22497] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
It has been reported that diabetic vascular dysfunction is associated with impaired function of large conductance Ca(2+) -activated K(+) (BK(Ca) ) channels. However, it is unclear whether impaired BK(Ca) channel directly participates in regulating diabetic vascular remodeling by altering cell growth in response to hyperglycemia. In the present study, we investigated the specific role of BK(Ca) channel in controlling apoptosis and proliferation under high glucose concentration (25 mM). The cDNA encoding the α+β1 subunit of BK(Ca) channel, hSloα+β1, was transiently transfected into human embryonic kidney 293 (HEK293) cells. Cloned BK(Ca) currents were recorded by both whole-cell and cell-attached patch clamp techniques. Cell apoptosis was assessed with immunocytochemistry and analysis of fragmented DNA by agarose gel electrophoresis. Cell proliferation was investigated by flow cytometry assays, MTT test, and immunocytochemistry. In addition, the expression of anti-apoptotic protein Bcl-2, intracellular Ca(2+) , and mitochondrial membrane potential (Δψm) were also examined to investigate the possible mechanisms. Our results indicate that inhibition of cloned BK(Ca) channels might be responsible for hyperglycemia-altered apoptosis and proliferation in HEK-hSloα+β1 cells. However, activation of BK(Ca) channel by NS1619 or Tamoxifen significantly induced apoptosis and suppressed proliferation in HEK-hSloα+β1 cells under hyperglycemia condition. When rat cerebral smooth muscle cells were cultured in hyperglycemia, similar findings were observed. Moreover, the possible mechanisms underlying the activation of BK(Ca) channel were associated with decreased expression of Bcl-2, elevation of intracellular Ca(2+) , and a concomitant depolarization of Δψm in HEK-hSloα+β1 cells. In conclusion, cloned BK(Ca) channel directly regulated apoptosis and proliferation of HEK293 cell under hyperglycemia condition.
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Affiliation(s)
- Hui Chang
- Department of Aerospace Physiology, Key Laboratory of Aerospace Medicine of Ministry of Education, Fourth Military Medical University, Xi'an, Shaanxi Province, China
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Xie MJ, Ma YG, Gao F, Bai YG, Cheng JH, Chang YM, Yu ZB, Ma J. Activation of BKCa channel is associated with increased apoptosis of cerebrovascular smooth muscle cells in simulated microgravity rats. Am J Physiol Cell Physiol 2010; 298:C1489-500. [DOI: 10.1152/ajpcell.00474.2009] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Cerebral arterial remodeling is one of the critical factors in the occurrence of postspaceflight orthostatic intolerance. We hypothesize that large-conductance calcium-activated K+ (BKCa) channels in vascular smooth muscle cells (VSMCs) may play an important role in regulating cerebrovascular adaptation during microgravity exposure. The aim of this work was to investigate whether activation of BKCa channels is involved in regulation of apoptotic remodeling of cerebral arteries in simulated microgravity rats. In animal studies, Sprague-Dawley rats were subjected to 1-wk hindlimb unweighting to simulate microgravity. Alterations of BKCa channels in cerebral VSMCs were investigated by patch clamp and Western blotting; apoptosis was assessed by electron microscopy and terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick-end labeling (TUNEL). To evaluate the correlation of BKCa channel and apoptosis, channel protein and cell nucleus were double-stained. In cell studies, hSloα+β1 channel was coexpressed into human embryonic kidney 293 (HEK293) cells to observe the effects of BKCa channels on apoptosis. In rats, enhanced activities and expression of BKCa channels were found to be correlated with increased apoptosis in cerebral VSMCs after simulated microgravity. In transfected HEK293 cells, activation of cloned BKCa channel induced apoptosis, whereas inhibition of cloned BKCa channel decreased apoptosis. In conclusion, activation of BKCa channels is associated with increased apoptosis in cerebral VSMCs of simulated microgravity rats.
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Affiliation(s)
- Man-Jiang Xie
- Department of Aerospace Physiology, Key Laboratory of Aerospace Medicine of Ministry of Education, and
| | - Yu-Guang Ma
- Department of Clinical Oncology, Xijing Hospital, Fourth Military Medical University, Xi'an; and
- Department of Breast Disease, First Hospital of Lanzhou University, Lanzhou, China
| | - Fang Gao
- Department of Aerospace Physiology, Key Laboratory of Aerospace Medicine of Ministry of Education, and
| | - Yun-Gang Bai
- Department of Aerospace Physiology, Key Laboratory of Aerospace Medicine of Ministry of Education, and
| | - Jiu-Hua Cheng
- Department of Aerospace Physiology, Key Laboratory of Aerospace Medicine of Ministry of Education, and
| | - Yao-Ming Chang
- Department of Aerospace Physiology, Key Laboratory of Aerospace Medicine of Ministry of Education, and
| | - Zhi-Bin Yu
- Department of Aerospace Physiology, Key Laboratory of Aerospace Medicine of Ministry of Education, and
| | - Jin Ma
- Department of Aerospace Physiology, Key Laboratory of Aerospace Medicine of Ministry of Education, and
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