1
|
Ge Y, Zhang B, Song J, Cao Q, Bu Y, Li P, Bai Y, Yang C, Xie M. Discovery of Salidroside as a Novel Non-Coding RNA Modulator to Delay Cellular Senescence and Promote BK-Dependent Apoptosis in Cerebrovascular Smooth Muscle Cells of Simulated Microgravity Rats. Int J Mol Sci 2023; 24:14531. [PMID: 37833978 PMCID: PMC10572139 DOI: 10.3390/ijms241914531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 09/08/2023] [Accepted: 09/12/2023] [Indexed: 10/15/2023] Open
Abstract
Cardiovascular aging has been reported to accelerate in spaceflights, which is a great potential risk to astronauts' health and performance. However, current exercise routines are not sufficient to reverse the adverse effects of microgravity exposure. Recently, salidroside (SAL), a valuable medicinal herb, has been demonstrated to display an important role for prevention and treatment in cardiovascular and other diseases. In the present work, Sprague-Dawley rats with four-week tail-suspension hindlimb-unloading were used to simulate microgravity effects on the cardiovascular system. We found that intragastrical administration of SAL not only significantly decreased the expressions of senescence biomarkers, such as P65 and P16, but also obviously increased the expressions of BK-dependent apoptotic genes, including the large-conductance calcium-activated K+ channel (BK), Bax, Bcl-2, and cleaved caspase-3, in vascular smooth muscle cells (VSMCs) in vivo and in vitro. In addition, relative non-coding RNAs were screened, and a luciferase assay identified that SAL increased apoptosis by activating LncRNA-FLORPAR, inhibiting miR-193, and then triggering the activity of the BK-α subunit. Our work indicated that SAL is a novel non-coding RNA modulator for regulating the LncRNA-FLORPAR sponging miR-193 pathway, which significantly promoted BK-dependent apoptosis and delayed cerebrovascular aging-like remodeling during simulated microgravity exposure. Our findings may provide a new approach to prevent cardiovascular aging in future spaceflights.
Collapse
Affiliation(s)
- Yiling Ge
- Department of Aerospace Physiology, Key Laboratory of Aerospace Medicine of Ministry of Education, Fourth Military Medical University, Xi’an 710032, China; (Y.G.); (B.Z.); (J.S.); (Q.C.); (Y.B.); (P.L.); (Y.B.)
| | - Bin Zhang
- Department of Aerospace Physiology, Key Laboratory of Aerospace Medicine of Ministry of Education, Fourth Military Medical University, Xi’an 710032, China; (Y.G.); (B.Z.); (J.S.); (Q.C.); (Y.B.); (P.L.); (Y.B.)
| | - Jibo Song
- Department of Aerospace Physiology, Key Laboratory of Aerospace Medicine of Ministry of Education, Fourth Military Medical University, Xi’an 710032, China; (Y.G.); (B.Z.); (J.S.); (Q.C.); (Y.B.); (P.L.); (Y.B.)
| | - Qinglin Cao
- Department of Aerospace Physiology, Key Laboratory of Aerospace Medicine of Ministry of Education, Fourth Military Medical University, Xi’an 710032, China; (Y.G.); (B.Z.); (J.S.); (Q.C.); (Y.B.); (P.L.); (Y.B.)
| | - Yingrui Bu
- Department of Aerospace Physiology, Key Laboratory of Aerospace Medicine of Ministry of Education, Fourth Military Medical University, Xi’an 710032, China; (Y.G.); (B.Z.); (J.S.); (Q.C.); (Y.B.); (P.L.); (Y.B.)
| | - Peijie Li
- Department of Aerospace Physiology, Key Laboratory of Aerospace Medicine of Ministry of Education, Fourth Military Medical University, Xi’an 710032, China; (Y.G.); (B.Z.); (J.S.); (Q.C.); (Y.B.); (P.L.); (Y.B.)
| | - Yungang Bai
- Department of Aerospace Physiology, Key Laboratory of Aerospace Medicine of Ministry of Education, Fourth Military Medical University, Xi’an 710032, China; (Y.G.); (B.Z.); (J.S.); (Q.C.); (Y.B.); (P.L.); (Y.B.)
| | - Changbin Yang
- Military Medical Innovation Center, Fourth Military Medical University, Xi’an 710032, China
| | - Manjiang Xie
- Department of Aerospace Physiology, Key Laboratory of Aerospace Medicine of Ministry of Education, Fourth Military Medical University, Xi’an 710032, China; (Y.G.); (B.Z.); (J.S.); (Q.C.); (Y.B.); (P.L.); (Y.B.)
| |
Collapse
|
2
|
7-Hydroxycoumarin Induces Vasorelaxation in Animals with Essential Hypertension: Focus on Potassium Channels and Intracellular Ca2+ Mobilization. Molecules 2022; 27:molecules27217324. [PMID: 36364149 PMCID: PMC9655823 DOI: 10.3390/molecules27217324] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 10/22/2022] [Accepted: 10/24/2022] [Indexed: 12/01/2022] Open
Abstract
Cardiovascular diseases (CVD) are the deadliest noncommunicable disease worldwide. Hypertension is the most prevalent risk factor for the development of CVD. Although there is a wide range of antihypertensive drugs, there still remains a lack of blood pressure control options for hypertensive patients. Additionally, natural products remain crucial to the design of new drugs. The natural product 7-hydroxycoumarin (7-HC) exhibits pharmacological properties linked to antihypertensive mechanisms of action. This study aimed to evaluate the vascular effects of 7-HC in an experimental model of essential hypertension. The isometric tension measurements assessed the relaxant effect induced by 7-HC (0.001 μM–300 μM) in superior mesenteric arteries isolated from hypertensive rats (SHR, 200–300 g). Our results suggest that the relaxant effect induced by 7-HC rely on K+-channels (KATP, BKCa, and, to a lesser extent, Kv) activation and also on Ca2+ influx from sarcolemma and sarcoplasmic reticulum mobilization (inositol 1,4,5-triphosphate (IP3) and ryanodine receptors). Moreover, 7-HC diminishes the mesenteric artery’s responsiveness to α1-adrenergic agonist challenge and improves the actions of the muscarinic agonist and NO donor. The present work demonstrated that the relaxant mechanism of 7-HC in SHR involves endothelium-independent vasorelaxant factors. Additionally, 7-HC reduced vasoconstriction of the sympathetic agonist while improving vascular endothelium-dependent and independent relaxation.
Collapse
|
3
|
De Silva TM, Sobey CG. Cerebral Vascular Biology in Health and Disease. Stroke 2022. [DOI: 10.1016/b978-0-323-69424-7.00001-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
4
|
Wu Y, Yue Z, Wang Q, Lv Q, Liu H, Bai Y, Li S, Xie M, Bao J, Ma J, Zhu X, Wang Z. BK Ca compensates impaired coronary vasoreactivity through RhoA/ROCK pathway in hind-limb unweighted rats. FASEB J 2019; 33:13358-13366. [PMID: 31530101 DOI: 10.1096/fj.201901273r] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Previous studies have demonstrated cardiac and vascular remodeling induced by microgravity exposure. Yet, as the most important branch of vasculatures circulating the heart, the coronary artery has been seldomly studied about its adaptations under microgravity conditions. Large-conductance Ca2+-activated potassium channel (BKCa) and the Ras homolog family member A (RhoA)/Rho kinase (ROCK) pathway play key roles in control of vascular tone and mediation of microgravity-induced vascular adjustments. Therefore, we investigated the adaptation of coronary vasoreactivity to simulated microgravity and the role of BKCa and the RhoA/ROCK pathway in it. Four-week-old hind-limb unweighted (HU) rats were adopted to simulate effects of microgravity. Right coronary artery (RCA) constriction was measured by isometric force recording. The activity and expression of BKCa and the RhoA/ROCK pathway were examined by Western blot, patch-clamp recordings, and immunoprecipitation. We found HU significantly decreased RCA vasoconstriction to KCl, serotonin, and U-46619, but increased protein expression and current densities of BKCa, inhibition of which by iberiotoxin (IBTX) further decreased RCA vasoconstriction (P < 0.05). Expression of RhoA and ROCK as well as active RhoA and phosphorylation of myosin light chain (MLC) at Ser19 and MLC phosphatase target-1 at Thr696 were significantly increased by HU, and ROCK inhibitor Y-27632 exerted greater suppressing effect on HU RCA vasoconstriction than that of control (P < 0.05). BKCa opener NS1619 increased HU RCA vasoconstriction, which was blocked by both RhoA and ROCK inhibitor, similar to the effect of IBTX. These results indicate that HU impairs coronary vasoconstriction but enhances BKCa activity acting as a protective mechanism avoiding excessive decrease of coronary vasoreactivity through activation of the RhoA/ROCK pathway.-Wu, Y., Yue, Z., Wang, Q., Lv, Q., Liu, H., Bai, Y., Li, S., Xie, M., Bao, J., Ma, J., Zhu, X., Wang, Z. BKCa compensates impaired coronary vasoreactivity through RhoA/ROCK pathway in hind-limb unweighted rats.
Collapse
Affiliation(s)
- Yue Wu
- Department of Congenital Heart Disease, General Hospital of Northern Theater Command, Shenyang, China.,Department of Medical Administration, General Hospital of Northern Theater Command, Shenyang, China
| | - Zhijie Yue
- Department of Aerospace Physiology, Fourth Military Medical University, Xi'an, China.,Department of Cardiology, Affiliated Hospital of The Bethune Medical Noncommissioned Officer (NCO) School, Army Medical University, Shijiazhuang, China
| | - Qiguang Wang
- Department of Congenital Heart Disease, General Hospital of Northern Theater Command, Shenyang, China
| | - Qiang Lv
- Department of Aerospace Physiology, Fourth Military Medical University, Xi'an, China
| | - Huan Liu
- Department of Aerospace Physiology, Fourth Military Medical University, Xi'an, China
| | - Yungang Bai
- Department of Aerospace Physiology, Fourth Military Medical University, Xi'an, China
| | - Shaohua Li
- Department of Aerospace Physiology, Fourth Military Medical University, Xi'an, China
| | - Manjiang Xie
- Department of Aerospace Physiology, Fourth Military Medical University, Xi'an, China
| | - Junxiang Bao
- Department of Aerospace Physiology, Fourth Military Medical University, Xi'an, China
| | - Jin Ma
- Department of Aerospace Physiology, Fourth Military Medical University, Xi'an, China
| | - Xianyang Zhu
- Department of Congenital Heart Disease, General Hospital of Northern Theater Command, Shenyang, China
| | - Zhongchao Wang
- Department of Congenital Heart Disease, General Hospital of Northern Theater Command, Shenyang, China.,Department of Aerospace Physiology, Fourth Military Medical University, Xi'an, China
| |
Collapse
|
5
|
Zeng XL, Sun L, Zheng HQ, Wang GL, Du YH, Lv XF, Ma MM, Guan YY. Smooth muscle-specific TMEM16A expression protects against angiotensin II-induced cerebrovascular remodeling via suppressing extracellular matrix deposition. J Mol Cell Cardiol 2019; 134:131-143. [PMID: 31301303 DOI: 10.1016/j.yjmcc.2019.07.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2018] [Revised: 07/04/2019] [Accepted: 07/04/2019] [Indexed: 12/16/2022]
Abstract
Cerebrovascular remodeling is the leading factor for stroke and characterized by increased extracellular matrix deposition, migration and proliferation of vascular smooth muscle cells, and inhibition of their apoptosis. TMEM16A is an important component of Ca2+-activated Cl- channels. Previously, we showed that downregulation of TMEM16A in the basilar artery was negatively correlated with cerebrovascular remodeling during hypertension. However, it is unclear whether TMEM16A participates in angiotensin II (Ang II)-induced vascular remodeling in mice that have TMEM16A gene modification. In this study, we generated a transgenic mouse that overexpresses TMEM16A specifically in vascular smooth muscle cells. We observed that vascular remodeling in the basilar artery during Ang II-induced hypertension was significantly suppressed upon vascular smooth muscle-specific overexpression of TMEM16A relative to control mice. Specifically, we observed a large reduction in the deposition of fibronectin and collagen I. The expression of matrix metalloproteinases (MMP-2, MMP-9, and MMP-14), and tissue inhibitors of metalloproteinases (TIMP-1 and TIMP-2) were upregulated in the basilar artery during Ang II-induced hypertension, but this was suppressed upon overexpression of TMEM16A in blood vessels. Furthermore, TMEM16A overexpression alleviated the overactivity of the canonical TGF-β1/Smad3, and non-canonical TGF-β1/ERK and JNK pathways in the basilar artery during Ang II-induced hypertension. These in vivo results were similar to the results derived in vitro with basilar artery smooth muscle cells stimulated by Ang II. Moreover, we observed that the inhibitory effect of TMEM16A on MMPs was mediated by decreasing the activation of WNK1, which is a Cl--sensitive serine/threonine kinase. In conclusion, this study demonstrates that TMEM16A protects against cerebrovascular remodeling during hypertension by suppressing extracellular matrix deposition. We also showed that TMEM16A exerts this effect by reducing the expression of MMPs via inhibiting WNK1, and decreasing the subsequent activities of TGF-β1/Smad3, ERK, and JNK. Accordingly, our results suggest that TMEM16A may serve as a novel therapeutic target for vascular remodeling.
Collapse
Affiliation(s)
- Xue-Lin Zeng
- Department of Pharmacology, and Cardiac & Cerebral Vascular Research Center, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China; Department of Pharmacy, The Seventh Affiliated Hospital of Sun Yat-sen University, Shenzhen, China
| | - Lu Sun
- Department of Pharmacology, and Cardiac & Cerebral Vascular Research Center, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China
| | - Hua-Qing Zheng
- Department of Pharmacology, and Cardiac & Cerebral Vascular Research Center, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China
| | - Guan-Lei Wang
- Department of Pharmacology, and Cardiac & Cerebral Vascular Research Center, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China.
| | - Yan-Hua Du
- Department of Pharmacology, and Cardiac & Cerebral Vascular Research Center, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China.
| | - Xiao-Fei Lv
- Department of Pharmacology, and Cardiac & Cerebral Vascular Research Center, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China.
| | - Ming-Ming Ma
- Department of Pharmacology, and Cardiac & Cerebral Vascular Research Center, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China.
| | - Yong-Yuan Guan
- Department of Pharmacology, and Cardiac & Cerebral Vascular Research Center, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China.
| |
Collapse
|
6
|
Sun Z, Li Y, Zhou H, Cai M, Liu J, Gao S, Yang J, Tong L, Wang J, Zhou S, Hu Z, Wang Y, Wang K, Zhang L, Wang H, Zhang L, Shi F, Cao X, Zhang S, Ji Y, Zhao J. Simulated microgravity reduces intracellular-free calcium concentration by inhibiting calcium channels in primary mouse osteoblasts. J Cell Biochem 2018; 120:4009-4020. [PMID: 30260002 DOI: 10.1002/jcb.27685] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 08/27/2018] [Indexed: 12/11/2022]
Abstract
Calcium homeostasis in osteoblasts plays fundamental roles in the physiology and pathology of bone tissue. Various types of mechanical stimuli promote osteogenesis and increase bone formation elicit increases in intracellular-free calcium concentration in osteoblasts. However, whether microgravity, a condition of mechanical unloading, exerts an influence on intracellular-free calcium concentration in osteoblasts or what mechanisms may underlie such an effect are unclear. Herein, we show that simulated microgravity reduces intracellular-free calcium concentration in primary mouse osteoblasts. In addition, simulated microgravity substantially suppresses the activities of L-type voltage-sensitive calcium channels, which selectively allow calcium to cross the plasma membrane from the extracellular space. Moreover, the functional expression of ryanodine receptors and inositol 1,4,5-trisphosphate receptors, which mediate the release of calcium from intracellular storage, decreased under simulated microgravity conditions. These results suggest that simulated microgravity substantially reduces intracellular-free calcium concentration through inhibition of calcium channels in primary mouse osteoblasts. Our study may provide a novel mechanism for microgravity-induced detrimental effects in osteoblasts, offering a new avenue to further investigate bone loss induced by mechanical unloading.
Collapse
Affiliation(s)
- Zhongyang Sun
- Department of Orthopedics, Jinling Hospital, Medical School of Nanjing University, Nanjing, China.,Department of Orthopedics, No. 454 Hospital of PLA, Anhui Medical University, Nanjing, China.,The Key Laboratory of Aerospace Medicine, Chinese Ministry of Education, Fourth Military Medical University, Xi'an, China
| | - Ying Li
- Department of Orthopedics, No. 454 Hospital of PLA, Anhui Medical University, Nanjing, China
| | - Hua Zhou
- Department of Emergency, First Affiliated Hospital, Xi'an Medical University, Xi'an, China
| | - Min Cai
- Department of Orthopedics, No. 454 Hospital of PLA, Anhui Medical University, Nanjing, China.,Medical Services Section, No. 454 Hospital of PLA, Anhui Medical University, Nanjing, China
| | - Jing Liu
- Department of Pharmacy, No. 454 Hospital of PLA, Anhui Medical University, Nanjing, China
| | - Shanshan Gao
- Medical Services Section, No. 454 Hospital of PLA, Anhui Medical University, Nanjing, China
| | - Junsheng Yang
- Department of Orthopedics, No. 454 Hospital of PLA, Anhui Medical University, Nanjing, China
| | - Liangcheng Tong
- Department of Orthopedics, No. 454 Hospital of PLA, Anhui Medical University, Nanjing, China
| | - Jianling Wang
- Department of Orthopedics, No. 454 Hospital of PLA, Anhui Medical University, Nanjing, China
| | - Sheng Zhou
- Department of Orthopedics, No. 454 Hospital of PLA, Anhui Medical University, Nanjing, China
| | - Zebing Hu
- The Key Laboratory of Aerospace Medicine, Chinese Ministry of Education, Fourth Military Medical University, Xi'an, China
| | - Yixuan Wang
- The Key Laboratory of Aerospace Medicine, Chinese Ministry of Education, Fourth Military Medical University, Xi'an, China
| | - Ke Wang
- The Key Laboratory of Aerospace Medicine, Chinese Ministry of Education, Fourth Military Medical University, Xi'an, China
| | - Lijun Zhang
- The Key Laboratory of Aerospace Medicine, Chinese Ministry of Education, Fourth Military Medical University, Xi'an, China
| | - Han Wang
- The Key Laboratory of Aerospace Medicine, Chinese Ministry of Education, Fourth Military Medical University, Xi'an, China
| | - Lianchang Zhang
- The Key Laboratory of Aerospace Medicine, Chinese Ministry of Education, Fourth Military Medical University, Xi'an, China
| | - Fei Shi
- The Key Laboratory of Aerospace Medicine, Chinese Ministry of Education, Fourth Military Medical University, Xi'an, China
| | - Xinsheng Cao
- The Key Laboratory of Aerospace Medicine, Chinese Ministry of Education, Fourth Military Medical University, Xi'an, China
| | - Shu Zhang
- The Key Laboratory of Aerospace Medicine, Chinese Ministry of Education, Fourth Military Medical University, Xi'an, China
| | - Yongzhang Ji
- Medical Services Section, No. 454 Hospital of PLA, Anhui Medical University, Nanjing, China
| | - Jianning Zhao
- Department of Orthopedics, Jinling Hospital, Medical School of Nanjing University, Nanjing, China
| |
Collapse
|
7
|
Zhang LF, Hargens AR. Spaceflight-Induced Intracranial Hypertension and Visual Impairment: Pathophysiology and Countermeasures. Physiol Rev 2017; 98:59-87. [PMID: 29167331 DOI: 10.1152/physrev.00017.2016] [Citation(s) in RCA: 129] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 05/25/2017] [Accepted: 05/26/2017] [Indexed: 12/21/2022] Open
Abstract
Visual impairment intracranial pressure (VIIP) syndrome is considered an unexplained major risk for future long-duration spaceflight. NASA recently redefined this syndrome as Spaceflight-Associated Neuro-ocular Syndrome (SANS). Evidence thus reviewed supports that chronic, mildly elevated intracranial pressure (ICP) in space (as opposed to more variable ICP with posture and activity on Earth) is largely accounted for by loss of hydrostatic pressures and altered hemodynamics in the intracranial circulation and the cerebrospinal fluid system. In space, an elevated pressure gradient across the lamina cribrosa, caused by a chronic but mildly elevated ICP, likely elicits adaptations of multiple structures and fluid systems in the eye which manifest themselves as the VIIP syndrome. A chronic mismatch between ICP and intraocular pressure (IOP) in space may acclimate the optic nerve head, lamina cribrosa, and optic nerve subarachnoid space to a condition that is maladaptive to Earth, all contributing to the pathogenesis of space VIIP syndrome. Relevant findings help to evaluate whether artificial gravity is an appropriate countermeasure to prevent this seemingly adverse effect of long-duration spaceflight.
Collapse
Affiliation(s)
- Li-Fan Zhang
- Department of Aerospace Physiology, Fourth Military Medical University, Xi'an, China; and Department of Orthopaedic Surgery, University of California, San Diego, California
| | - Alan R Hargens
- Department of Aerospace Physiology, Fourth Military Medical University, Xi'an, China; and Department of Orthopaedic Surgery, University of California, San Diego, California
| |
Collapse
|
8
|
Ma YG, Liang L, Zhang YB, Wang BF, Bai YG, Dai ZJ, Xie MJ, Wang ZW. Berberine reduced blood pressure and improved vasodilation in diabetic rats. J Mol Endocrinol 2017; 59:191-204. [PMID: 28515053 DOI: 10.1530/jme-17-0014] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 05/17/2017] [Indexed: 12/14/2022]
Abstract
Hyperglycemia and hypertension are considered to be the two leading risk factors for vascular disease in diabetic patients. However, few pharmacologic agents could provide a combinational therapy for controlling hyperglycemia and hypertension at the same time in diabetes. The objectives of this study are to investigate whether berberine treatment could directly reduce blood pressure and identify the molecular mechanism underlying the vascular protection of berberine in diabetic rats. Berberine was intragastrically administered with different dosages of 50, 100 and 200 mg/kg/day to diabetic rats for 8 weeks since the injection of streptozotocin. The endothelium-dependent/-independent relaxation in middle cerebral arteries was investigated. The activity of large-conductance Ca2+-activated K+ channel (BKCa) was investigated by recording whole-cell currents, analyzing single-channel activities and assessing the expressions of α- and β1-subunit at protein or mRNA levels. Results of the study suggest that chronic administration of 100 mg/kg/day berberine not only lowered blood glucose but also reduced blood pressure and improved vasodilation in diabetic rats. Furthermore, berberine markedly increased the function and expression of BKCa β1-subunit in cerebral vascular smooth muscle cells (VSMCs) isolated from diabetic rats or when exposed to hyperglycemia condition. The present study provided initial evidences that berberine reduced blood pressure and improved vasodilation in diabetic rats by activation of BKCa channel in VSMCs, which suggested that berberine might provide a combinational therapy for controlling hyperglycemia and blood pressure in diabetes. Furthermore, our work indicated that activation of BKCa channel might be the underlying mechanism responsible for the vascular protection of berberine in diabetes.
Collapse
Affiliation(s)
- Yu-Guang Ma
- Department of OncologyThe Second Affiliated Hospital of Medical College, Xi'an Jiaotong University, Xi'an, Shaanxi Province, China
| | - Liang Liang
- Department of OncologyThe Second Affiliated Hospital of Medical College, Xi'an Jiaotong University, Xi'an, Shaanxi Province, China
| | - Yin-Bin Zhang
- Department of OncologyThe Second Affiliated Hospital of Medical College, Xi'an Jiaotong University, Xi'an, Shaanxi Province, China
| | - Bao-Feng Wang
- Department of OncologyThe Second Affiliated Hospital of Medical College, Xi'an Jiaotong University, Xi'an, Shaanxi Province, China
| | - Yun-Gang Bai
- Department of OncologyThe Second Affiliated Hospital of Medical College, Xi'an Jiaotong University, Xi'an, Shaanxi Province, China
| | - Zhi-Jun Dai
- Department of OncologyThe Second Affiliated Hospital of Medical College, Xi'an Jiaotong University, Xi'an, Shaanxi Province, China
| | - Man-Jiang Xie
- Department of Aerospace PhysiologyKey Laboratory of Aerospace Medicine of Ministry of Education, Fourth Military Medical University, Xi'an, Shaanxi Province, China
| | - Zhong-Wei Wang
- Department of OncologyThe Second Affiliated Hospital of Medical College, Xi'an Jiaotong University, Xi'an, Shaanxi Province, China
| |
Collapse
|
9
|
Ma YG, Wang JW, Bai YG, Liu M, Xie MJ, Dai ZJ. Salidroside contributes to reducing blood pressure and alleviating cerebrovascular contractile activity in diabetic Goto-Kakizaki Rats by inhibition of L-type calcium channel in smooth muscle cells. BMC Pharmacol Toxicol 2017; 18:30. [PMID: 28441970 PMCID: PMC5405536 DOI: 10.1186/s40360-017-0135-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 04/01/2017] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Vascular disease is a common and often severe complication in diabetes mellitus. Hyperglycemia and hypertension are considered to be two of the leading risk factors for vascular complications in diabetic patients. However, few pharmacologic agents could provide a combinational therapy for controlling hyperglycemia and blood pressure in diabetic patients at the same time. Salidroside (SAL) is the major active ingredient derived from Rhodiola. Recently, it has been reported that SAL have an obvious hypoglycemic effect in diabetes and show a beneficial activity in diabetic vascular dysfunction. However, it remains unknown whether or not SAL treatment could directly reduce blood pressure in diabetes. Furthermore, it is not clear what is the molecular mechanism underlying the vascular protection of SAL treatment in diabetes. METHODS Male diabetic Goto-Kakizaki (GK) and non-diabetic control Wistar-Kyoto (WKY) rats were administrated with different dosages of SAL (50, 100 and 200 mg/kg/day) for 4 weeks. Contractile responsiveness of cerebral artery to KCl or 5-HT was investigated by Pressure Myograph System. The activity of CaL channel was investigated by recording whole-cell currents, assessing the expressions of CaL channel α1C-subunit and its downstream kinase, MLCK, at protein or mRNA levels. RESULTS We showed that administration of 100 mg/kg/day SAL for 4 weeks not only lowered blood glucose, but also reduced blood pressure and alleviated cerebrovascular contractile activity in diabetic GK rats, which suggested that SAL treatment may provide a combinational therapy for lowering blood glucose and reducing blood pressure in diabetes at the same time. Furthermore, SAL treatment markedly inhibited the function and expression of CaL channel in cerebral VSMCs isolated from diabetic GK rats or when exposed to hyperglycemia condition, which may be the underlying mechanism responsible for the vascular protection of SAL in diabetes. CONCLUSIONS The present study provided evidences that SAL contributes to reducing blood pressure and alleviating cerebrovascular contractile activity in diabetic GK rats by inhibition of CaL channel in smooth muscle cells, which may provide a novel approach to treat vascular complications in diabetic patients.
Collapse
Affiliation(s)
- Yu-Guang Ma
- Department of Oncology, The Second Affiliated Hospital of Medical College, Xi'an Jiaotong University, Xi'an, Shaanxi Province, 710004, China
| | - Jun-Wei Wang
- Department of Cardiovascular Medicine, Shaanxi Provincial People's Hospital, Xi'an, Shaanxi, 710068, China
| | - Yun-Gang Bai
- Department of Aerospace Physiology, Key Laboratory of Aerospace Medicine of Ministry of Education, Fourth Military Medical University, Xi'an, 710032, Shaanxi Province, China
| | - Mei Liu
- Department of Oncology, The Second Affiliated Hospital of Medical College, Xi'an Jiaotong University, Xi'an, Shaanxi Province, 710004, China
| | - Man-Jiang Xie
- Department of Aerospace Physiology, Key Laboratory of Aerospace Medicine of Ministry of Education, Fourth Military Medical University, Xi'an, 710032, Shaanxi Province, China.
| | - Zhi-Jun Dai
- Department of Oncology, The Second Affiliated Hospital of Medical College, Xi'an Jiaotong University, Xi'an, Shaanxi Province, 710004, China.
| |
Collapse
|
10
|
|
11
|
Sun Z, Cao X, Hu Z, Zhang L, Wang H, Zhou H, Li D, Zhang S, Xie M. MiR-103 inhibits osteoblast proliferation mainly through suppressing Cav1.2 expression in simulated microgravity. Bone 2015; 76:121-8. [PMID: 25868801 DOI: 10.1016/j.bone.2015.04.006] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Revised: 03/17/2015] [Accepted: 04/02/2015] [Indexed: 01/22/2023]
Abstract
Emerging evidence indicates that microRNAs (miRNAs) play important roles in modulating osteoblast function and bone formation. However, the influence of miRNA on osteoblast proliferation and the possible mechanisms underlying remain to be defined. In this study, we aimed to investigate whether miR-103 regulates osteoblast proliferation under simulated microgravity condition through regulating Cav1.2, the primary subunit of L-type voltage sensitive calcium channels (LTCCs). We first investigated the effect of simulated microgravity on osteoblast proliferation and the outcomes clearly demonstrated that the mechanical unloading inhibits MC3T3-E1 osteoblast-like cell proliferation. Using quantitative Real-Time PCR (qRT-PCR), we provided data showing that miR-103 was up-regulated in response to simulated microgravity. In addition, we observed that up-regulation of miR-103 inhibited and down-regulation of miR-103 promoted osteoblast proliferation under simulated microgravity condition. Furthermore, knocking-down or over-expressing miR-103, respectively, up- or down-regulated the level of Cav1.2 expression and LTCC currents, suggesting that miR-103 acts as an endogenous attenuator of Cav1.2 in osteoblasts under simulated microgravity condition. More importantly, we showed that the effect of miR-103 on osteoblast proliferation was diminished in simulated microgravity, when co-transfecting miR-103 mimic or inhibitor with Cav1.2 siRNA. Taken together, our data suggest that miR-103 inhibits osteoblast proliferation mainly through suppression of Cav1.2 expression under simulated microgravity condition. This work may provide a novel mechanism of microgravity-induced detrimental effects on osteoblast proliferation, identifying miR-103 as a novel possible therapeutic target in bone remodeling disorders in this mechanical unloading.
Collapse
Affiliation(s)
- Zhongyang Sun
- The Key Laboratory of Aerospace Medicine, Ministry of Education, The Fourth Military Medical University, 710032 Xi'an, Shaanxi, China
| | - Xinsheng Cao
- The Key Laboratory of Aerospace Medicine, Ministry of Education, The Fourth Military Medical University, 710032 Xi'an, Shaanxi, China
| | - Zebing Hu
- The Key Laboratory of Aerospace Medicine, Ministry of Education, The Fourth Military Medical University, 710032 Xi'an, Shaanxi, China
| | - Lianchang Zhang
- The Key Laboratory of Aerospace Medicine, Ministry of Education, The Fourth Military Medical University, 710032 Xi'an, Shaanxi, China
| | - Han Wang
- The Key Laboratory of Aerospace Medicine, Ministry of Education, The Fourth Military Medical University, 710032 Xi'an, Shaanxi, China
| | - Hua Zhou
- The Key Laboratory of Aerospace Medicine, Ministry of Education, The Fourth Military Medical University, 710032 Xi'an, Shaanxi, China
| | - Dongtao Li
- Center of Cardiology, Navy General Hospital, 100048 Beijing, China
| | - Shu Zhang
- The Key Laboratory of Aerospace Medicine, Ministry of Education, The Fourth Military Medical University, 710032 Xi'an, Shaanxi, China.
| | - Manjiang Xie
- The Key Laboratory of Aerospace Medicine, Ministry of Education, The Fourth Military Medical University, 710032 Xi'an, Shaanxi, China.
| |
Collapse
|
12
|
Sun Z, Cao X, Zhang Z, Hu Z, Zhang L, Wang H, Zhou H, Li D, Zhang S, Xie M. Simulated microgravity inhibits L-type calcium channel currents partially by the up-regulation of miR-103 in MC3T3-E1 osteoblasts. Sci Rep 2015; 5:8077. [PMID: 25627864 PMCID: PMC4308706 DOI: 10.1038/srep08077] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 01/05/2015] [Indexed: 11/25/2022] Open
Abstract
L-type voltage-sensitive calcium channels (LTCCs), particularly Cav1.2 LTCCs, play fundamental roles in cellular responses to mechanical stimuli in osteoblasts. Numerous studies have shown that mechanical loading promotes bone formation, whereas the removal of this stimulus under microgravity conditions results in a reduction in bone mass. However, whether microgravity exerts an influence on LTCCs in osteoblasts and whether this influence is a possible mechanism underlying the observed bone loss remain unclear. In the present study, we demonstrated that simulated microgravity substantially inhibited LTCC currents and suppressed Cav1.2 at the protein level in MC3T3-E1 osteoblast-like cells. In addition, reduced Cav1.2 protein levels decreased LTCC currents in MC3T3-E1 cells. Moreover, simulated microgravity increased miR-103 expression. Cav1.2 expression and LTCC current densities both significantly increased in cells that were transfected with a miR-103 inhibitor under mechanical unloading conditions. These results suggest that simulated microgravity substantially inhibits LTCC currents in osteoblasts by suppressing Cav1.2 expression. Furthermore, the down-regulation of Cav1.2 expression and the inhibition of LTCCs caused by mechanical unloading in osteoblasts are partially due to miR-103 up-regulation. Our study provides a novel mechanism for microgravity-induced detrimental effects on osteoblasts, offering a new avenue to further investigate the bone loss induced by microgravity.
Collapse
Affiliation(s)
- Zhongyang Sun
- The Key Laboratory of Aerospace Medicine, Ministry of Education, The Fourth Military Medical University, 710032, Xi'an, Shaanxi, China
| | - Xinsheng Cao
- The Key Laboratory of Aerospace Medicine, Ministry of Education, The Fourth Military Medical University, 710032, Xi'an, Shaanxi, China
| | - Zhuo Zhang
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, 710032, Xi'an, Shaanxi, China
| | - Zebing Hu
- The Key Laboratory of Aerospace Medicine, Ministry of Education, The Fourth Military Medical University, 710032, Xi'an, Shaanxi, China
| | - Lianchang Zhang
- The Key Laboratory of Aerospace Medicine, Ministry of Education, The Fourth Military Medical University, 710032, Xi'an, Shaanxi, China
| | - Han Wang
- The Key Laboratory of Aerospace Medicine, Ministry of Education, The Fourth Military Medical University, 710032, Xi'an, Shaanxi, China
| | - Hua Zhou
- The Key Laboratory of Aerospace Medicine, Ministry of Education, The Fourth Military Medical University, 710032, Xi'an, Shaanxi, China
| | - Dongtao Li
- Center of Cardiology, Navy General Hospital, 100048, Beijing, China
| | - Shu Zhang
- The Key Laboratory of Aerospace Medicine, Ministry of Education, The Fourth Military Medical University, 710032, Xi'an, Shaanxi, China
| | - Manjiang Xie
- The Key Laboratory of Aerospace Medicine, Ministry of Education, The Fourth Military Medical University, 710032, Xi'an, Shaanxi, China
| |
Collapse
|
13
|
Shi ZX, Rao W, Wang H, Wang ND, Si JW, Zhao J, Li JC, Wang ZR. Modeled microgravity suppressed invasion and migration of human glioblastoma U87 cells through downregulating store-operated calcium entry. Biochem Biophys Res Commun 2015; 457:378-84. [PMID: 25580009 DOI: 10.1016/j.bbrc.2014.12.120] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 12/31/2014] [Indexed: 10/24/2022]
Abstract
Glioblastoma is the most common brain tumor and is characterized with robust invasion and migration potential resulting in poor prognosis. Previous investigations have demonstrated that modeled microgravity (MMG) could decline the cell proliferation and attenuate the metastasis potential in several cell lines. In this study, we studied the effects of MMG on the invasion and migration potentials of glioblastoma in human glioblastoma U87 cells. We found that MMG stimulation significantly attenuated the invasion and migration potentials, decreased thapsigargin (TG) induced store-operated calcium entry (SOCE) and downregulated the expression of Orai1 in U87 cells. Inhibition of SOCE by 2-APB or stromal interaction molecule 1 (STIM1) downregulation both mimicked the effects of MMG on the invasion and migration potentials in U87 cells. Furthermore, upregulation of Orai1 significantly weakened the effects of MMG on the invasion and migration potentials in U87 cells. Therefore, these findings indicated that MMG stimulation inhibited the invasion and migration potentials of U87 cells by downregulating the expression of Orai1 and sequentially decreasing the SOCE, suggesting that MMG might be a new potential therapeutic strategy in glioblastoma treatment in the future.
Collapse
Affiliation(s)
- Zi-xuan Shi
- Department of Traditional Chinese Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, PR China
| | - Wei Rao
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, PR China
| | - Huan Wang
- Department of Dermatology, Tangdu Hospital, Fourth Military Medical University, Xi'an, 710032, PR China
| | - Nan-ding Wang
- Department of Cardiology, Xi'an Traditional Chinese Medicine Hospital, Xi'an, 710032, PR China
| | - Jing-wen Si
- Department of Traditional Chinese Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, PR China
| | - Jiao Zhao
- Department of Traditional Chinese Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, PR China
| | - Jun-chang Li
- Department of Traditional Chinese Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, PR China
| | - Zong-ren Wang
- Department of Traditional Chinese Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, 710032, PR China.
| |
Collapse
|
14
|
Cheng JH, Zhang LF, Gao F, Bai YG, Boscolo M, Huang XF, Zhang X. Mechanics and composition of middle cerebral arteries from simulated microgravity rats with and without 1-h/d -Gx gravitation. PLoS One 2014; 9:e97737. [PMID: 24840155 PMCID: PMC4026390 DOI: 10.1371/journal.pone.0097737] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Accepted: 04/24/2014] [Indexed: 11/26/2022] Open
Abstract
Background To elucidate further from the biomechanical aspect whether microgravity-induced cerebral vascular mal-adaptation might be a contributing factor to postflight orthostatic intolerance and the underlying mechanism accounting for the potential effectiveness of intermittent artificial gravity (IAG) in preventing this adverse effect. Methodology/Principal Findings Middle cerebral arteries (MCAs) were isolated from 28-day SUS (tail-suspended, head-down tilt rats to simulate microgravity effect), S+D (SUS plus 1-h/d −Gx gravitation by normal standing to simulate IAG), and CON (control) rats. Vascular myogenic reactivity and circumferential stress-strain and axial force-pressure relationships and overall stiffness were examined using pressure arteriography and calculated. Acellular matrix components were quantified by electron microscopy. The results demonstrate that myogenic reactivity is susceptible to previous pressure-induced, serial constrictions. During the first-run of pressure increments, active MCAs from SUS rats can strongly stiffen their wall and maintain the vessels at very low strains, which can be prevented by the simulated IAG countermeasure. The strains are 0.03 and 0.14 respectively for SUS and S+D, while circumferential stress being kept at 0.5 (106 dyn/cm2). During the second-run pressure steps, both the myogenic reactivity and active stiffness of the three groups declined. The distensibility of passive MCAs from S+D is significantly higher than CON and SUS, which may help to attenuate the vasodilatation impairment at low levels of pressure. Collagen and elastin percentages were increased and decreased, respectively, in MCAs from SUS and S+D as compared with CON; however, elastin was higher in S+D than SUS rats. Conclusions Susceptibility to previous myogenic constrictions seems to be a self-limiting protective mechanism in cerebral small resistance arteries to prevent undue cerebral vasoconstriction during orthostasis at 1-G environment. Alleviating of active stiffening and increasing of distensibility of cerebral resistance arteries may underlie the countermeasure effectiveness of IAG.
Collapse
Affiliation(s)
- Jiu-Hua Cheng
- Department of Aerospace Physiology and Key Laboratory of Aerospace Medicine of Ministry of Education, Fourth Military Medical University, Xi'an, China
| | - Li-Fan Zhang
- Department of Aerospace Physiology and Key Laboratory of Aerospace Medicine of Ministry of Education, Fourth Military Medical University, Xi'an, China
- * E-mail:
| | - Fang Gao
- Department of Aerospace Physiology and Key Laboratory of Aerospace Medicine of Ministry of Education, Fourth Military Medical University, Xi'an, China
| | - Yun-Gang Bai
- Department of Aerospace Physiology and Key Laboratory of Aerospace Medicine of Ministry of Education, Fourth Military Medical University, Xi'an, China
| | - Marco Boscolo
- Department of Aerospace Engineering, Cranfield University, Cranfield, United Kingdom
| | - Xiao-Feng Huang
- Central Laboratory, School of Basic Medical Sciences, Fourth Military Medical University, Xi'an, China
| | - Xiang Zhang
- Department of Aerospace Engineering, Cranfield University, Cranfield, United Kingdom
| |
Collapse
|
15
|
Up-regulation of ryanodine receptor expression increases the calcium-induced calcium release and spontaneous calcium signals in cerebral arteries from hindlimb unloaded rats. Pflugers Arch 2013; 466:1517-28. [DOI: 10.1007/s00424-013-1387-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Revised: 10/02/2013] [Accepted: 10/15/2013] [Indexed: 10/26/2022]
|
16
|
Pires PW, Dams Ramos CM, Matin N, Dorrance AM. The effects of hypertension on the cerebral circulation. Am J Physiol Heart Circ Physiol 2013; 304:H1598-614. [PMID: 23585139 DOI: 10.1152/ajpheart.00490.2012] [Citation(s) in RCA: 250] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Maintenance of brain function depends on a constant blood supply. Deficits in cerebral blood flow are linked to cognitive decline, and they have detrimental effects on the outcome of ischemia. Hypertension causes alterations in cerebral artery structure and function that can impair blood flow, particularly during an ischemic insult or during periods of low arterial pressure. This review will focus on the historical discoveries, novel developments, and knowledge gaps in 1) hypertensive cerebral artery remodeling, 2) vascular function with emphasis on myogenic reactivity and endothelium-dependent dilation, and 3) blood-brain barrier function. Hypertensive artery remodeling results in reduction in the lumen diameter and an increase in the wall-to-lumen ratio in most cerebral arteries; this is linked to reduced blood flow postischemia and increased ischemic damage. Many factors that are increased in hypertension stimulate remodeling; these include the renin-angiotensin-aldosterone system and reactive oxygen species levels. Endothelial function, vital for endothelium-mediated dilation and regulation of myogenic reactivity, is impaired in hypertension. This is a consequence of alterations in vasodilator mechanisms involving nitric oxide, epoxyeicosatrienoic acids, and ion channels, including calcium-activated potassium channels and transient receptor potential vanilloid channel 4. Hypertension causes blood-brain barrier breakdown by mechanisms involving inflammation, oxidative stress, and vasoactive circulating molecules. This exposes neurons to cytotoxic molecules, leading to neuronal loss, cognitive decline, and impaired recovery from ischemia. As the population ages and the incidence of hypertension, stroke, and dementia increases, it is imperative that we gain a better understanding of the control of cerebral artery function in health and disease.
Collapse
Affiliation(s)
- Paulo W Pires
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824, USA
| | | | | | | |
Collapse
|
17
|
Zhang LF. Region-specific vascular remodeling and its prevention by artificial gravity in weightless environment. Eur J Appl Physiol 2013; 113:2873-95. [DOI: 10.1007/s00421-013-2597-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2012] [Accepted: 01/20/2013] [Indexed: 10/27/2022]
|
18
|
Bannister JP, Bulley S, Narayanan D, Thomas-Gatewood C, Luzny P, Pachuau J, Jaggar JH. Transcriptional upregulation of α2δ-1 elevates arterial smooth muscle cell voltage-dependent Ca2+ channel surface expression and cerebrovascular constriction in genetic hypertension. Hypertension 2012; 60:1006-15. [PMID: 22949532 DOI: 10.1161/hypertensionaha.112.199661] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
A hallmark of hypertension is an increase in arterial myocyte voltage-dependent Ca2+ (CaV1.2) currents that induces pathological vasoconstriction. CaV1.2 channels are heteromeric complexes composed of a pore-forming CaV1.2α1 with auxiliary α2δ and β subunits. Molecular mechanisms that elevate CaV1.2 currents during hypertension and the potential contribution of CaV1.2 auxiliary subunits are unclear. Here, we investigated the pathological significance of α2δ subunits in vasoconstriction associated with hypertension. Age-dependent development of hypertension in spontaneously hypertensive rats was associated with an unequal elevation in α2δ-1 and CaV1.2α1 mRNA and protein in cerebral artery myocytes, with α2δ-1 increasing more than CaV1.2α1. Other α2δ isoforms did not emerge in hypertension. Myocytes and arteries of hypertensive spontaneously hypertensive rats displayed higher surface-localized α2δ-1 and CaV1.2α1 proteins, surface α2δ-1:CaV1.2α1 ratio, CaV1.2 current density and noninactivating current, and pressure- and depolarization-induced vasoconstriction than those of Wistar-Kyoto controls. Pregabalin, an α2δ-1 ligand, did not alter α2δ-1 or CaV1.2α1 total protein but normalized α2δ-1 and CaV1.2α1 surface expression, surface α2δ-1:CaV1.2α1, CaV1.2 current density and inactivation, and vasoconstriction in myocytes and arteries of hypertensive rats to control levels. Genetic hypertension is associated with an elevation in α2δ-1 expression that promotes surface trafficking of CaV1.2 channels in cerebral artery myocytes. This leads to an increase in CaV1.2 current-density and a reduction in current inactivation that induces vasoconstriction. Data also suggest that α2δ-1 targeting is a novel strategy that may be used to reverse pathological CaV1.2 channel trafficking to induce cerebrovascular dilation in hypertension.
Collapse
Affiliation(s)
- John P Bannister
- Department of Physiology, College of Medicine, University of Tennessee Health Science Center, 894 Union Ave, Suite 426, Memphis, TN 38163, USA
| | | | | | | | | | | | | |
Collapse
|
19
|
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.
Collapse
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)
| |
Collapse
|
20
|
Wang M, Yang H, Zheng LY, Zhang Z, Tang YB, Wang GL, Du YH, Lv XF, Liu J, Zhou JG, Guan YY. Downregulation of TMEM16A calcium-activated chloride channel contributes to cerebrovascular remodeling during hypertension by promoting basilar smooth muscle cell proliferation. Circulation 2012; 125:697-707. [PMID: 22215857 DOI: 10.1161/circulationaha.111.041806] [Citation(s) in RCA: 122] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
BACKGROUND The Ca(2+)-activated chloride channel (CaCC) plays an important role in a variety of physiological functions. In vascular smooth muscle cells, CaCC is involved in the regulation of agonist-stimulated contraction and myogenic tone. The physiological functions of CaCC in blood vessels are not fully revealed because of the lack of specific channel blockers and the uncertainty concerning its molecular identity. METHODS AND RESULTS Whole-cell patch-clamp studies showed that knockdown of TMEM16A but not bestrophin-3 attenuated CaCC currents in rat basilar smooth muscle cells. The activity of CaCC in basilar smooth muscle cells isolated from 2-kidney, 2-clip renohypertensive rats was decreased, and CaCC activity was negatively correlated with blood pressure (n=25; P<0.0001) and medial cross-sectional area (n=24; P<0.0001) in basilar artery during hypertension. Both upregulation of CaMKII activity and downregulation of TMEM16A expression contributed to the reduction of CaCC in the hypertensive basilar artery. Western blot results demonstrated that angiotensin II repressed TMEM16A expression in basilar smooth muscle cells (n=6; P<0.01). Knockdown of TMEM16A facilitated and overexpression of TMEM16A inhibited angiotensin II-induced cell cycle transition and cell proliferation determined by flow cytometry and BrdU incorporation (n=6 in each group; P<0.05). TMEM16A affected cell cycle progression mainly through regulating the expression of cyclin D1 and cyclin E. CONCLUSIONS TMEM16A CaCC is a negative regulator of cell proliferation. Downregulation of CaCC may play an important role in hypertension-induced cerebrovascular remodeling, suggesting that modification of the activity of CaCC may be a novel therapeutic strategy for hypertension-associated cardiovascular diseases such as stroke.
Collapse
Affiliation(s)
- Mi Wang
- Department of Pharmacology, Zhongshan School of Medicine, Sun Yat-Sen University, 74 Zhongshan 2 Rd, Guangzhou, China
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Xue JH, Chen LH, Zhao HZ, Pu YD, Feng HZ, Ma YG, Ma J, Chang YM, Zhang ZM, Xie MJ. Differential regulation and recovery of intracellular Ca2+ in cerebral and small mesenteric arterial smooth muscle cells of simulated microgravity rat. PLoS One 2011; 6:e19775. [PMID: 21611118 PMCID: PMC3097196 DOI: 10.1371/journal.pone.0019775] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Accepted: 04/05/2011] [Indexed: 01/15/2023] Open
Abstract
Background The differential adaptations of cerebrovasculature and small mesenteric arteries could be one of critical factors in postspaceflight orthostatic intolerance, but the cellular mechanisms remain unknown. We hypothesize that there is a differential regulation of intracellular Ca2+ determined by the alterations in the functions of plasma membrane CaL channels and ryanodine-sensitive Ca2+ releases from sarcoplasmic reticulum (SR) in cerebral and small mesenteric vascular smooth muscle cells (VSMCs) of simulated microgravity rats, respectively. Methodology/Principal Findings Sprague-Dawley rats were subjected to 28-day hindlimb unweighting to simulate microgravity. In addition, tail-suspended rats were submitted to a recovery period of 3 or 7 days after removal of suspension. The function of CaL channels was evaluated by patch clamp and Western blotting. The function of ryanodine-sensitive Ca2+ releases in response to caffeine were assessed by a laser confocal microscope. Our results indicated that simulated microgravity increased the functions of CaL channels and ryanodine-sensitive Ca2+ releases in cerebral VSMCs, whereas, simulated microgravity decreased the functions of CaL channels and ryanodine-sensitive Ca2+ releases in small mesenteric VSMCs. In addition, 3- or 7-day recovery after removal of suspension could restore the functions of CaL channels and ryanodine-sensitive Ca2+ releases to their control levels in cerebral and small mesenteric VSMCs, respectively. Conclusions The differential regulation of CaL channels and ryanodine-sensitive Ca2+ releases in cerebral and small mesenteric VSMCs may be responsible for the differential regulation of intracellular Ca2+, which leads to the altered autoregulation of cerebral vasculature and the inability to adequately elevate peripheral vascular resistance in postspaceflight orthostatic intolerance.
Collapse
Affiliation(s)
- Jun-Hui Xue
- Department of Aerospace Clinical Medicine, Key Laboratory of Aerospace Medicine of Ministry of Education, Fourth Military Medical University, Xi'an, Shaanxi Province, China
| | - Lian-Hong Chen
- Department of Chest Surgery, Tangdu Hospital of Fourth Military Medical University, Xi'an, Shaanxi Province, China
| | - Hua-Zhou Zhao
- 309 Clinical Divisions, Department of General Surgery, General Hospital of PLA, Beijing, China
| | - Yong-Dong Pu
- 309 Clinical Divisions, Department of General Surgery, General Hospital of PLA, Beijing, China
| | - Han-Zhong Feng
- Department of Aerospace Physiology, Key Laboratory of Aerospace Medicine of Ministry of Education, Fourth Military Medical University, Xi'an, Shaanxi Province, China
| | - Yu-Guang Ma
- Department of Aerospace Physiology, Key Laboratory of Aerospace Medicine of Ministry of Education, Fourth Military Medical University, Xi'an, Shaanxi Province, China
| | - Jin Ma
- Department of Aerospace Physiology, Key Laboratory of Aerospace Medicine of Ministry of Education, Fourth Military Medical University, Xi'an, Shaanxi Province, China
| | - Yao-Ming Chang
- Department of Aerospace Clinical Medicine, Key Laboratory of Aerospace Medicine of Ministry of Education, Fourth Military Medical University, Xi'an, Shaanxi Province, China
- Department of Aerospace Physiology, Key Laboratory of Aerospace Medicine of Ministry of Education, Fourth Military Medical University, Xi'an, Shaanxi Province, China
| | - Zuo-Ming Zhang
- Department of Aerospace Clinical Medicine, Key Laboratory of Aerospace Medicine of Ministry of Education, Fourth Military Medical University, Xi'an, Shaanxi Province, China
- * E-mail: (Z-MZ); (M-JX)
| | - Man-Jiang Xie
- Department of Aerospace Physiology, Key Laboratory of Aerospace Medicine of Ministry of Education, Fourth Military Medical University, Xi'an, Shaanxi Province, China
- * E-mail: (Z-MZ); (M-JX)
| |
Collapse
|
22
|
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.
Collapse
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
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Ma YG, Dong L, Ye XL, Deng CL, Cheng JH, Liu WC, Ma J, Chang YM, Xie MJ. Activation of cloned BK(Ca) channels in nitric oxide-induced apoptosis of HEK293 cells. Apoptosis 2010; 15:426-38. [PMID: 20012488 DOI: 10.1007/s10495-009-0423-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The large conductance Ca(2+)-activated K(+) (BK(Ca)) channels are highly expressed in vascular smooth muscle cells (VSMCs) and play an essential role in the regulation of various physiological functions. Besides its electrophysiological function in vascular relaxation, BK(Ca) has also been reported to be implicated in nitric oxide (NO)-induced apoptosis of VSMCs. However, the molecular mechanism is not clear and has not been determined on cloned channels. The present study was designed to clarify whether activation of cloned BK(Ca) channel was involved in NO-induced apoptosis in human embryonic kidney 293 (HEK293) cell. The cDNA encoding the alpha-subunit of BK(Ca) channel, hSloalpha, was transiently transfected into HEK293 cells. The apoptotic death in HEK-hSloalpha cells was detected using immunocytochemistry, analysis of fragmented DNA by agarose gel electrophoresis, MTT test, and flow cytometry assays. Whole-cell and single-channel characteristics of HEK-hSloalpha cells exhibited functional features similar to native BK(Ca) channel in VSMCs. Exposuring of HEK- hSloalpha cells to S-nitroso-N-acetyl-penicillamine increased the hSloalpha channel activities of whole-cell and single-channel, and then increased percentage of cells undergoing apoptosis. However, blocking hSloalpha channels with 1 mM tetraethylammonia or 100 nM iberiotoxin significantly decreased the NO-induced apoptosis, whereas 30 microM NS1619, the specific agonist of BK(Ca), independently increased hSloalpha currents and induced apoptosis. These results indicated that activation of cloned BK(Ca) channel was involved in NO-induced apoptosis of HEK293 cells.
Collapse
Affiliation(s)
- Yu-Guang Ma
- Department of Clinical Oncology, Xijing Hospital, Fourth Military Medical University, Xi'an, China
| | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Li YJ, Bao JX, Xu JW, Murad F, Bian K. Vascular dilation by paeonol--a mechanism study. Vascul Pharmacol 2010; 53:169-76. [PMID: 20643226 DOI: 10.1016/j.vph.2010.07.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2010] [Revised: 05/20/2010] [Accepted: 07/02/2010] [Indexed: 11/28/2022]
Abstract
The goal of this study was to investigate the mechanism underlaying the vasodilatory effect of paeonol, a major active element from the root bark of Chinese herbs Paeonia suffruticosa Andr. and Cynanchum paniculatum (Bunge) Kitagawa. Paeonol relaxed isolated rat aorta rings by 95.6% while the 10(-6) M forskolin-induced vasodilatation used as 100%. The EC(50) of vasodilatation by paeonol is 2.9x10(-4) M. Although paeonol exerted endothelium-independent relaxation, L-NAME treatment inhibited paeonol-induced vasodilation of endothelium intact rings, while indomethacin did not. Both L-NAME and ODQ did not affect paeonol relaxation in the rings without endothelium. In addition, paeonol markedly elevated NO generation in cultured endothelial cells. Pre-treatment of propranolol, glibenclamide, TEA and BaCl(2) did not affect paeonol relaxation of endothelium removed rings. On the other hand, pre-treated of rings (without endothelium) with paeonol markedly blocked vasoconstriction induced by AngII, PGF(2alpha), 5-HT, dopamine, vasopressin, endothelin-1 and PE. The paeonol incubation also significantly attenuated KCl-induced contraction which mainly depended on Ca(2+) influx. In Ca(2+)-free medium (containing 10(-4) M of EGTA and 60 mM of KCl), paeonol suppressed the contraction curve of CaCl(2). In addition, paeonol also inhibited contraction by PE in Ca(2+) free solution (containing 10(-4) M of EGTA) which mainly relied on intracellular Ca(2+) release. Whole-cell patch-clamp experiment showed that paeonol shifted the I-V curve and the peak value of calcium currents was significantly inhibited. In conclusion, our study suggested that voltage-dependent and receptor-operated Ca(2+) channel, as well as intracellular Ca(2+) release were all inhibited by paeonol. An intracellular Ca(2+) regulatory mechanism may be responsible to potent vasodilatory effect of paeonol.
Collapse
Affiliation(s)
- Ya-juan Li
- Murad Research Institute for Modernized Chinese Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai, PR China
| | | | | | | | | |
Collapse
|
25
|
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.
Collapse
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
| |
Collapse
|
26
|
Lin LJ, Gao F, Bai YG, Bao JX, Huang XF, Ma J, Zhang LF. Contrasting effects of simulated microgravity with and without daily −Gx gravitation on structure and function of cerebral and mesenteric small arteries in rats. J Appl Physiol (1985) 2009; 107:1710-21. [DOI: 10.1152/japplphysiol.00493.2009] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This study was designed to test the hypothesis that a 28-day tail suspension (SUS) could induce hypertrophy and enhanced myogenic and vasoconstrictor reactivity in middle cerebral arteries (MCAs), whereas atrophy and decreased myogenic and vasoconstrictor responses in mesenteric third-order arterioles (MSAs). Also, in addition to the functional enhancement in MCAs, structural changes in both kinds of arteries and functional decrement in MSAs could all be prevented by the intervention of daily 1-h dorsoventral (−Gx) gravitation by restoring to standing posture. To test this hypothesis, vessel diameters to pressure alterations and nonreceptor- and receptor-mediated agonists were determined using a pressure arteriograph with a procedure to measure in vivo length and decrease hysteresis of vessel segments and longitudinal middlemost sections of vessels fixed at maximally dilated state were examined using electron microscopy and histomorphometry. Functional studies showed that 28-day tail-suspended, head-down tilt (SUS) resulted in enhanced and decreased myogenic tone and vasoconstrictor responses, respectively, in MCAs and MSAs. Histomorphometric data revealed that SUS-induced hypertrophic changes in MCAs characterized by increases in thickness (T) and cross-sectional area (CSA) of the media and the number of vascular smooth-muscle-cell layers (NCL), whereas in MSAs, it induced decreases in medial CSA and T and NCL. Daily 1-h −Gx over 28 days can fully prevent these differential structural changes in both kinds of small arteries and the functional decrement in MSAs, but not the augmented myogenic tone and increased vasoreactivity in the MCAs. These findings have revealed special features of small resistance arteries during adaptation to microgravity with and without gravity-based countermeasure.
Collapse
Affiliation(s)
- Le-Jian Lin
- Department of Aerospace Physiology and Key Laboratory of Aerospace Medicine of Ministry of Education,
| | - Fang Gao
- Department of Aerospace Physiology and Key Laboratory of Aerospace Medicine of Ministry of Education,
| | - Yun-Gang Bai
- Department of Aerospace Physiology and Key Laboratory of Aerospace Medicine of Ministry of Education,
| | - Jun-Xiang Bao
- Department of Aerospace Physiology and Key Laboratory of Aerospace Medicine of Ministry of Education,
| | - Xiao-Feng Huang
- Central Laboratory, School of Basic Medicine, Fourth Military Medical University, Xi'an, China
| | - Jin Ma
- Department of Aerospace Physiology and Key Laboratory of Aerospace Medicine of Ministry of Education,
| | - Li-Fan Zhang
- Department of Aerospace Physiology and Key Laboratory of Aerospace Medicine of Ministry of Education,
| |
Collapse
|
27
|
Li J, Deng CL, Gao F, Cheng JH, Yu ZB, Liu L, Xie MJ. Coexpression and characterization of the human large-conductance Ca2+-activated K+ channel α + β1 subunits in HEK293 cells. Mol Cell Biochem 2009; 331:117-26. [DOI: 10.1007/s11010-009-0149-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2008] [Accepted: 04/23/2009] [Indexed: 12/30/2022]
|
28
|
Tobin AA, Joseph BK, Al-Kindi HN, Albarwani S, Madden JA, Nemetz LT, Rusch NJ, Rhee SW. Loss of cerebrovascular Shaker-type K(+) channels: a shared vasodilator defect of genetic and renal hypertensive rats. Am J Physiol Heart Circ Physiol 2009; 297:H293-303. [PMID: 19411284 DOI: 10.1152/ajpheart.00991.2008] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The cerebral arteries of hypertensive rats are depolarized and highly myogenic, suggesting a loss of K(+) channels in the vascular smooth muscle cells (VSMCs). The present study evaluated whether the dilator function of the prominent Shaker-type voltage-gated K(+) (K(V)1) channels is attenuated in middle cerebral arteries from two rat models of hypertension. Block of K(V)1 channels by correolide (1 micromol/l) or psora-4 (100 nmol/l) reduced the resting diameter of pressurized (80 mmHg) cerebral arteries from normotensive rats by an average of 28 +/- 3% or 26 +/- 3%, respectively. In contrast, arteries from spontaneously hypertensive rats (SHR) and aortic-banded (Ao-B) rats with chronic hypertension showed enhanced Ca(2+)-dependent tone and failed to significantly constrict to correolide or psora-4, implying a loss of K(V)1 channel-mediated vasodilation. Patch-clamp studies in the VSMCs of SHR confirmed that the peak K(+) current density attributed to K(V)1 channels averaged only 5.47 +/- 1.03 pA/pF, compared with 9.58 +/- 0.82 pA/pF in VSMCs of control Wistar-Kyoto rats. Subsequently, Western blots revealed a 49 +/- 7% to 66 +/- 7% loss of the pore-forming alpha(1.2)- and alpha(1.5)-subunits that compose K(V)1 channels in cerebral arteries of SHR and Ao-B rats compared with control animals. In each case, the deficiency of K(V)1 channels was associated with reduced mRNA levels encoding either or both alpha-subunits. Collectively, these findings demonstrate that a deficit of alpha(1.2)- and alpha(1.5)-subunits results in a reduced contribution of K(V)1 channels to the resting diameters of cerebral arteries from two rat models of hypertension that originate from different etiologies.
Collapse
Affiliation(s)
- Ann A Tobin
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI, USA
| | | | | | | | | | | | | | | |
Collapse
|
29
|
Xue JH, Zhang LF, Ma J, Xie MJ. Differential regulation of L-type Ca2+ channels in cerebral and mesenteric arteries after simulated microgravity in rats and its intervention by standing. Am J Physiol Heart Circ Physiol 2007; 293:H691-701. [PMID: 17351067 DOI: 10.1152/ajpheart.01229.2006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This study was designed to clarify whether simulated microgravity can induce differential changes in the current and protein expression of the L-type Ca(2+) channel (Ca(L)) in cerebral and mesenteric arteries and whether these changes can be prevented by daily short-duration -G(x) exposure. Tail suspension [hindlimb unloading (HU)] for 3 and 28 days was used to simulate short- and medium-term microgravity-induced deconditioning effects. Standing (STD) for 1 h/day was used to provide -G(x) as a countermeasure. Whole cell patch-clamp experiments revealed an increase in current density of Ca(L) of vascular smooth muscle cells (VSMCs) isolated from cerebral arteries of rats subjected to HU and a decrease in VSMCs from mesenteric arteries. Western blot analysis revealed a significant increase and decrease of Ca(L) channel protein expression in cerebral and small mesenteric arterial VSMCs, respectively, only after 28 days of HU. STD for 1 h/day did not prevent the increase of Ca(L) current density in cerebral arterial VSMCs, but it prevented completely (within 3 days) and partially (28 days) the decrease of Ca(L) current density in small mesenteric arterial VSMCs. Consistent with the changes in Ca(L) current, STD for 1 h/day did not prevent the increase of Ca(L) expression in cerebrovascular myocytes but did prevent the reduction of Ca(L) expression in mesenteric arterial VSMCs subjected to 28 days of HU. These data indicate that simulated microgravity up- and downregulates the current and expression of Ca(L) in cerebral and hindquarter VSMCs, respectively. STD for 1 h/day differentially counteracted the changes of Ca(L) function and expression in cerebral and hindquarter arterial VSMCs of HU rats, suggesting the complexity of the underlying mechanisms in the effectiveness of intermittent artificial gravity for prevention of postflight cardiovascular deconditioning, which needs further clarification.
Collapse
Affiliation(s)
- Jun-Hui Xue
- Department of Aerospace Physiology, Fourth Military Medical University, Xi'an 710032, China
| | | | | | | |
Collapse
|