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Sallam NA, Wang B, Laher I. Exercise training and vascular heterogeneity in db/db mice: evidence for regional- and duration-dependent effects. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2024; 397:2421-2436. [PMID: 37843589 DOI: 10.1007/s00210-023-02775-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 10/04/2023] [Indexed: 10/17/2023]
Abstract
Exercise training (ET) has several health benefits; however, our understanding of regional adaptations to ET is limited. We examined the functional and molecular adaptations to short- and long-term ET in elastic and muscular conduit arteries of db/db mice in relation to changes in cardiovascular risk factors. Diabetic mice and their controls were exercised at moderate intensity for 4 or 8 weeks. The vasodilatory and contractile responses of thoracic aortae and femoral arteries isolated from the same animals were examined. Blood and aortic samples were used to measure hyperglycemia, oxidative stress, inflammation, dyslipidemia, protein expression of SOD isoforms, COX, eNOS, and Akt. Short-term ET improved nitric oxide (NO) mediated vasorelaxation in the aortae and femoral arteries of db/db mice in parallel with increased SOD2 and SOD3 expression, reduced oxidative stress and triglycerides, and independent of weight loss, glycemia, or inflammation. Long-term ET reduced body weight in parallel with reduced systemic inflammation and improved insulin sensitivity along with increased SOD1, Akt, and eNOS expression and improved NO vasorelaxation. Exercise did not restore NOS- and COX-independent vasodilatation in femoral arteries, nor did it mitigate the hypercontractility in the aortae of db/db mice; rather ET transiently increased contractility in association with upregulated COX-2. Long-term ET differentially affected the aortae and femoral arteries contractile responses. ET improved NO-mediated vasodilation in both arteries likely due to collective systemic effects. ET did not mitigate all diabetes-induced vasculopathies. Optimization of the ET regimen can help develop comprehensive management of type 2 diabetes.
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Affiliation(s)
- Nada A Sallam
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Cairo University, Cairo, 11562, Egypt
| | - Baohua Wang
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, BC, V6T1Z4, Canada
| | - Ismail Laher
- Department of Anesthesiology, Pharmacology and Therapeutics, University of British Columbia, Vancouver, BC, V6T1Z4, Canada.
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Chen J, Shi W, Xu Y, Zhang H, Chen B. Hirudin prevents vascular endothelial cell apoptosis and permeability enhancement induced by the serum from rat with chronic renal failure through inhibiting RhoA/ROCK signaling pathway. Drug Dev Res 2020; 82:553-561. [PMID: 33345328 DOI: 10.1002/ddr.21773] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 11/25/2020] [Accepted: 12/02/2020] [Indexed: 11/12/2022]
Abstract
Endothelial cells injury and activation contribute to arteriovenous fistula (AVF) stenosis. Hirudin (Hiru) can inhibit the activity of thrombin, which was reported to enhance endothelial cell permeability and promote vascular inflammatory responses. RhoA/ROCK signaling pathway is also important in regulating vascular endothelial permeability. This study aimed to investigate the role of Hiru on the viability and permeability of human umbilical vein endothelial cells (HUVECs) following stimulation of serum from rat with chronic renal failure (CRF) and illustrated the effects of Hiru on RhoA/ROCK signaling. Wistar rats were randomly divided into control group and CRF group. Serum from each group was collected to stimulate HUVECs. Proliferation capability was estimated with Cell Count Kit-8 (CCK-8) assay. Transwell assay was performed to determine permeability. Cell apoptosis was examined using Tunel staining. Telomere length and telomerase activity were determined by qPCR. Moreover, the expression of RhoA, ROCK1 and ROCK2 was estimated via western blot. Results showed that the serum from CRF rat significantly inhibited cell viability while enhanced cell permeability and apoptosis. Different concentrations of Hiru prevented the above effects caused by CRF serum. Additionally, Hiru recovered the CRF serum-induced decreased telomere length and telomerase activity. Hiru also inhibited the protein expression of RhoA, ROCK1 and ROCK2, which were activated by CRF serum. Moreover, the ROCK inhibitor, Y27632, exhibited similar effects with Hiru. In conclusion, Hiru-restored HUVECs cell viability, telomere length and telomerase activity, suppressed permeability and apoptosis in the presence of CRF serum might depend on inactivating the RhoA/ROCK signaling.
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Affiliation(s)
- Jing Chen
- Department of Nephrology, Lianyungang Hospital of Traditional Chinese Medicine, Lianyungang, China
| | - Wenbin Shi
- Department of Nephrology, Lianyungang Hospital of Traditional Chinese Medicine, Lianyungang, China
| | - Yan Xu
- Department of Nephrology, Lianyungang Hospital of Traditional Chinese Medicine, Lianyungang, China
| | - Huaming Zhang
- Department of Nephrology, Lianyungang Hospital of Traditional Chinese Medicine, Lianyungang, China
| | - Bo Chen
- Department of Nephrology, Lianyungang Hospital of Traditional Chinese Medicine, Lianyungang, China
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Yang H, Chen XY, Kuang SJ, Zhou MY, Zhang L, Zeng Z, Liu L, Wu FL, Zhang MZ, Mai LP, Yang M, Xue YM, Rao F, Deng CY. Abnormal Ca 2+ handling contributes to the impairment of aortic smooth muscle contractility in Zucker diabetic fatty rats. J Mol Cell Cardiol 2020; 141:82-92. [PMID: 32222458 DOI: 10.1016/j.yjmcc.2020.03.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 02/17/2020] [Accepted: 03/09/2020] [Indexed: 12/21/2022]
Abstract
Vascular dysfunction is a common pathological basis for complications in individuals affected by diabetes. Previous studies have established that endothelial dysfunction is the primary contributor to vascular complications in type 2 diabetes (T2DM). However, the role of vascular smooth muscle cells (VSMCs) in vascular complications associated with T2DM is still not completely understood. The aim of this study is to explore the potential mechanisms associated with Ca2+ handling dysfunction and how this dysfunction contributes to diabetic vascular smooth muscle impairment. The results indicated that endothelium-dependent vasodilation was impaired in diabetic aortae, but endothelium-independent vasodilation was not altered. Various vasoconstrictors such as phenylephrine, U46619 and 5-HT could induce vasoconstriction in a concentration-dependent manner, such that the dose-response curve was parallel shifted to the right in diabetic aortae, compared to the control. Vasoconstrictions mediated by L-type calcium (Cav1.2) channels were attenuated in diabetic aortae, but effects mediated by store-operated calcium (SOC) channels were enhanced. Intracellular Ca2+ concentration ([Ca2+]i) in VSMCs was detected by Fluo-4 calcium fluorescent probes, and demonstrated that SOC-mediated Ca2+ entry was increased in diabetic VSMCs. VSMC-specific knockout of STIM1 genes decreased SOC-mediated and phenylephrine-induced vasoconstrictive response in mice aortae. Additionally, Orai1 expression was up-regulated, Cav1.2 expression was downregulated, and the phenotypic transformation of diabetic VSMCs was determined in diabetic aortae. The overexpression of Orai1 markedly promoted the OPN expression of VSMCs, whereas SKF96365 (SOC channel blocker) reversed the phenotypic transformation of diabetic VSMCs. Our results demonstrated that the vasoconstriction response of aortic smooth muscle was weakened in type 2 diabetic rats, which was related to the downregulation of the Cav1.2 channel and the up-regulation of the SOC channel signaling pathway.
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Affiliation(s)
- Hui Yang
- Guangdong Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China; Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China
| | - Xiao-Yan Chen
- Guangdong Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China; Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China
| | - Su-Juan Kuang
- Guangdong Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China; Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China
| | - Meng-Yuan Zhou
- Guangdong Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China; Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China; School of biological science and engineering, South China University of Technology, Guangzhou 510006, China
| | - Li Zhang
- Guangdong Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China; Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China; School of biological science and engineering, South China University of Technology, Guangzhou 510006, China
| | - Zheng Zeng
- Department of Gynecology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou 510630, Guangdong, China
| | - Lin Liu
- Guangdong Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China; Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China
| | - Fei-Long Wu
- Guangdong Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China; Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China
| | - Meng-Zhen Zhang
- Guangdong Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China; Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China
| | - Li-Ping Mai
- Guangdong Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China; Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China
| | - Min Yang
- Guangdong Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China; Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China
| | - Yu-Mei Xue
- Guangdong Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China; Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China
| | - Fang Rao
- Guangdong Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China; Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China.
| | - Chun-Yu Deng
- Guangdong Provincial Key Laboratory of Clinical Pharmacology, Research Center of Medical Sciences, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China; Department of Cardiology, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou 510080, China.
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4
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Liu L, Huang XW, Yang H, Kuang SJ, Lian FH, Zhang MZ, Rao F, Shan ZX, Lin QX, Yang M, Lin JJ, Jiang S, Zhou ZL, Deng CY. Comparison of Ca 2+ Handling for the Regulation of Vasoconstriction between Rat Coronary and Renal Arteries. J Vasc Res 2019; 56:191-203. [DOI: 10.1159/000501614] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 06/20/2019] [Indexed: 11/19/2022] Open
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Involvement of inhibitor kappa B kinase 2 (IKK2) in the regulation of vascular tone. J Transl Med 2018; 98:1311-1319. [PMID: 29785049 DOI: 10.1038/s41374-018-0061-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 03/22/2018] [Accepted: 03/23/2018] [Indexed: 11/09/2022] Open
Abstract
Inhibitor kappa B kinase 2 (IKK2) plays an essential role in the activation of nuclear factor kappa B (NF-kB). Recently, it has been suggested that IKK2 acts as a myosin light chain kinase (MLCK) and contributes to vasoconstriction in mouse aorta. However, the underlying mechanisms are still unknown. Therefore, we investigated whether IKK2 acts as a MLCK or regulates the activity of myosin light chain phosphatase (MLCP). Pressure myograph was used to measure vascular tone in rat mesenteric arteries. Immunofluorescence staining was performed to identify phosphorylation levels of MLC (ser19), MYPT1 (thr853 and thr696) and CPI-17 (thr38). SC-514 (IKK2 inhibitor, 50 μM) induced relaxation in the mesenteric arteries pre-contracted with 70 mM high K+ solution or U-46619 (thromboxane analog, 5 μM). The relaxation induced by SC-514 was increased in the arteries pre-contracted with U-46619 compared to arteries pre-contracted with 70 mM high K+ solution. U-46619-induced contraction was decreased by treatment of SC-514 in the presence of MLCK inhibitor, ML-7 (10 μM). In the absence of intracellular Ca2+, U-46619 still induced contraction, which was decreased by treatment of SC-514. Furthermore, phosphorylation levels of MLC (ser19) and MYPT1 (thr853) were decreased by treatment of SC-514. IKK2 is involved in the vascular contraction through regulation of MLCP activity by phosphorylating MYPT1 at thr853 in rat mesenteric arteries. These findings suggest IKK2 could be a new pharmacological target for specific therapies of various vascular diseases.
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6
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Rho-kinase and the nitric oxide pathway modulate basilar arterial reactivity to acetylcholine and angiotensin II in streptozotocin-induced diabetic mice. Naunyn Schmiedebergs Arch Pharmacol 2017; 390:929-938. [DOI: 10.1007/s00210-017-1396-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 06/16/2017] [Indexed: 12/11/2022]
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7
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Effects of Hyperglycemia on Vascular Smooth Muscle Ca 2+ Signaling. BIOMED RESEARCH INTERNATIONAL 2017; 2017:3691349. [PMID: 28713824 PMCID: PMC5497615 DOI: 10.1155/2017/3691349] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Accepted: 05/24/2017] [Indexed: 12/25/2022]
Abstract
Diabetes is a complex disease that is characterized with hyperglycemia, dyslipidemia, and insulin resistance. These pathologies are associated with significant cardiovascular implications that affect both the macro- and microvasculature. It is therefore important to understand the effects of various pathologies associated with diabetes on the vasculature. Here we directly test the effects of hyperglycemia on vascular smooth muscle (VSM) Ca2+ signaling in an isolated in vitro system using the A7r5 rat aortic cell line as a model. We find that prolonged exposure of A7r5 cells to hyperglycemia (weeks) is associated with changes to Ca2+ signaling, including most prominently an inhibition of the passive ER Ca2+ leak and the sarcoplasmic reticulum Ca2+-ATPase (SERCA). To translate these findings to the in vivo condition, we used primary VSM cells from normal and diabetic subjects and find that only the inhibition of the ER Ca2+ leaks replicates in cells from diabetic donors. These results show that prolonged hyperglycemia in isolation alters the Ca2+ signaling machinery in VSM cells. However, these alterations are not readily translatable to the whole organism situation where alterations to the Ca2+ signaling machinery are different.
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8
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Kuang SJ, Qian JS, Yang H, Rao F, Chen XY, Zhang MZ, Shan ZX, Lin QX, Xue YM, Wu SL, Jiang L, Chen CB, Deng CY. The enhancement of TXA 2 receptors-mediated contractile response in intrarenal artery dysfunction in type 2 diabetic mice. Eur J Pharmacol 2017; 805:93-100. [PMID: 28286123 DOI: 10.1016/j.ejphar.2017.03.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 02/28/2017] [Accepted: 03/08/2017] [Indexed: 11/28/2022]
Abstract
Thromboxane A2 (TXA2) has been implicated in the pathogenesis of diabetic vascular complications, although the underlying mechanism remains unclear. The present study investigated the alterations in TXA2 receptor signal transduction in type 2 diabetic renal arteries. The contraction of renal arterial rings in control (db/m+) mice and type 2 diabetic (db/db) mice was measured by a Multi Myograph System. Intracellular calcium concentration ([Ca2+]i) in vascular smooth muscle cells was measured by Fluo-4/AM dye and confocal laser scanning microscopy. Quantitative real-time PCR and Western blot analysis were used to determine gene and protein expression levels, respectively. A stable TXA2 mimic U46619 caused markedly stronger dose-dependent contractions in the renal arteries of db/db mice than in those of db/m+ mice. This response was completely blocked by a TXA2 receptor antagonist GR32191 and significantly inhibited by U73122. U46619-induced vasoconstriction was increased in the presence of nifedipine in db/db mice compared with that in db/m+ mice, whereas the response to U46619 did not differ between the two groups in the presence of SKF96365. Sarcoplasmic reticulum Ca2+ release-mediated and CaCl2-induced contractions did not differ between the two groups. In db/db mice, store-operated Ca2+(SOC) entry-mediated contraction in the renal arteries and SOC entry-mediated Ca2+ influx in smooth muscle cells were significantly increased. And the gene and protein expressions of TXA2 receptors, Orai1 and Stim1 were upregulated in the diabetic renal arteries. Therefore the enhancement of U46619-induced contraction was mediated by the upregulation of TXA2 receptors and downstream signaling in the diabetic renal arteries.
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Affiliation(s)
- Su-Juan Kuang
- Guangdong Cardiovascular Institute, PR China; Department of Medical Research, Guangdong General Hospital, PR China; Guangdong Academy of Medical Sciences, Guangzhou 510080, PR China
| | - Jie-Sheng Qian
- Department of Radiology, Intervention Radiology Institute, The Third Affiliated Hospital, Sun Yat-Sen University, Guangzhou, PR China
| | - Hui Yang
- Guangdong Cardiovascular Institute, PR China; Department of Medical Research, Guangdong General Hospital, PR China; Guangdong Academy of Medical Sciences, Guangzhou 510080, PR China
| | - Fang Rao
- Guangdong Cardiovascular Institute, PR China; Department of Medical Research, Guangdong General Hospital, PR China; Guangdong Academy of Medical Sciences, Guangzhou 510080, PR China
| | - Xiao-Yan Chen
- Guangdong Cardiovascular Institute, PR China; Department of Medical Research, Guangdong General Hospital, PR China; Guangdong Academy of Medical Sciences, Guangzhou 510080, PR China
| | - Meng-Zhen Zhang
- Guangdong Cardiovascular Institute, PR China; Department of Medical Research, Guangdong General Hospital, PR China; Guangdong Academy of Medical Sciences, Guangzhou 510080, PR China
| | - Zhi-Xin Shan
- Guangdong Cardiovascular Institute, PR China; Department of Medical Research, Guangdong General Hospital, PR China; Guangdong Academy of Medical Sciences, Guangzhou 510080, PR China
| | - Qiu-Xiong Lin
- Guangdong Cardiovascular Institute, PR China; Department of Medical Research, Guangdong General Hospital, PR China; Guangdong Academy of Medical Sciences, Guangzhou 510080, PR China
| | - Yu-Mei Xue
- Guangdong Cardiovascular Institute, PR China; Department of Medical Research, Guangdong General Hospital, PR China; Guangdong Academy of Medical Sciences, Guangzhou 510080, PR China
| | - Shu-Lin Wu
- Guangdong Cardiovascular Institute, PR China; Department of Medical Research, Guangdong General Hospital, PR China; Guangdong Academy of Medical Sciences, Guangzhou 510080, PR China
| | - Li Jiang
- Guangdong Academy of Medical Sciences, Guangzhou 510080, PR China
| | - Chun-Bo Chen
- Guangdong Cardiovascular Institute, PR China; Department of Medical Research, Guangdong General Hospital, PR China; Guangdong Academy of Medical Sciences, Guangzhou 510080, PR China.
| | - Chun-Yu Deng
- Guangdong Cardiovascular Institute, PR China; Department of Medical Research, Guangdong General Hospital, PR China; Guangdong Academy of Medical Sciences, Guangzhou 510080, PR China.
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Abd-Elrahman KS, Colinas O, Walsh EJ, Zhu HL, Campbell CM, Walsh MP, Cole WC. Abnormal myosin phosphatase targeting subunit 1 phosphorylation and actin polymerization contribute to impaired myogenic regulation of cerebral arterial diameter in the type 2 diabetic Goto-Kakizaki rat. J Cereb Blood Flow Metab 2017; 37:227-240. [PMID: 26721393 PMCID: PMC5363741 DOI: 10.1177/0271678x15622463] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 10/26/2015] [Accepted: 11/17/2015] [Indexed: 12/11/2022]
Abstract
The myogenic response of cerebral resistance arterial smooth muscle to intraluminal pressure elevation is a key physiological mechanism regulating blood flow to the brain. Rho-associated kinase plays a critical role in the myogenic response by activating Ca2+ sensitization mechanisms: (i) Rho-associated kinase inhibits myosin light chain phosphatase by phosphorylating its targeting subunit myosin phosphatase targeting subunit 1 (at T855), augmenting 20 kDa myosin regulatory light chain (LC20) phosphorylation and force generation; and (ii) Rho-associated kinase stimulates cytoskeletal actin polymerization, enhancing force transmission to the cell membrane. Here, we tested the hypothesis that abnormal Rho-associated kinase-mediated myosin light chain phosphatase regulation underlies the dysfunctional cerebral myogenic response of the Goto-Kakizaki rat model of type 2 diabetes. Basal levels of myogenic tone, LC20, and MYPT1-T855 phosphorylation were elevated and G-actin content was reduced in arteries of pre-diabetic 8-10 weeks Goto-Kakizaki rats with normal serum insulin and glucose levels. Pressure-dependent myogenic constriction, LC20, and myosin phosphatase targeting subunit 1 phosphorylation and actin polymerization were suppressed in both pre-diabetic Goto-Kakizaki and diabetic (18-20 weeks) Goto-Kakizaki rats, whereas RhoA, ROK2, and MYPT1 expression were unaffected. We conclude that abnormal Rho-associated kinase-mediated Ca2+ sensitization contributes to the dysfunctional cerebral myogenic response in the Goto-Kakizaki model of type 2 diabetes.
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Affiliation(s)
- Khaled S Abd-Elrahman
- The Smooth Muscle Research Group, Departments of Physiology & Pharmacology, Libin Cardiovascular Institute & Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Alberta, Canada
| | - Olaia Colinas
- The Smooth Muscle Research Group, Departments of Physiology & Pharmacology, Libin Cardiovascular Institute & Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Alberta, Canada
| | - Emma J Walsh
- The Smooth Muscle Research Group, Departments of Physiology & Pharmacology, Libin Cardiovascular Institute & Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Alberta, Canada
| | - Hai-Lei Zhu
- The Smooth Muscle Research Group, Departments of Physiology & Pharmacology, Libin Cardiovascular Institute & Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Alberta, Canada
| | - Christine M Campbell
- The Smooth Muscle Research Group, Departments of Physiology & Pharmacology, Libin Cardiovascular Institute & Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Alberta, Canada
| | - Michael P Walsh
- The Smooth Muscle Research Group, Department of Biochemistry & Molecular Biology, Libin Cardiovascular Institute & Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Alberta, Canada
| | - William C Cole
- The Smooth Muscle Research Group, Departments of Physiology & Pharmacology, Libin Cardiovascular Institute & Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Alberta, Canada
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Abd-Elrahman KS, Walsh MP, Cole WC. Abnormal Rho-associated kinase activity contributes to the dysfunctional myogenic response of cerebral arteries in type 2 diabetes. Can J Physiol Pharmacol 2015; 93:177-84. [PMID: 25660561 DOI: 10.1139/cjpp-2014-0437] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The structural and functional integrity of the brain, and therefore, cognition, are critically dependent on the appropriate control of blood flow within the cerebral circulation. Inadequate flow leads to ischemia, whereas excessive flow causes small vessel rupture and (or) blood-brain-barrier disruption. Cerebral blood flow is controlled through the interplay of several physiological mechanisms that regulate the contractile state of vascular smooth muscle cells (VSMCs) within the walls of cerebral resistance arteries and arterioles. The myogenic response of cerebral VSMCs is a key mechanism that is responsible for maintaining constant blood flow during variations in systemic pressure, i.e., flow autoregulation. Inappropriate myogenic control of cerebral blood flow is associated with, and prognostic of, neurological deterioration and poor outcome in patients with several conditions, including type 2 diabetes. Here, we review recent advances in our understanding of the role of inappropriate Rho-associated kinase activity as a cause of impaired myogenic regulation of cerebral arterial diameter in type 2 diabetes.
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Affiliation(s)
- Khaled S Abd-Elrahman
- The Smooth Muscle Research Group, Libin Cardiovascular Institute, Hotchkiss Brain Institute, and the Department of Physiology & Pharmacology, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, AB T2N 4N1, Canada
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11
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Nobe K, Takenouchi Y, Kasono K, Hashimoto T, Honda K. Two Types of Overcontraction Are Involved in Intrarenal Artery Dysfunction in Type II Diabetic Mouse. J Pharmacol Exp Ther 2014; 351:77-86. [DOI: 10.1124/jpet.114.216747] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
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12
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Liu L, Liu J, Gao Y, Yu X, Dou D, Huang Y. Protein kinase Cδ contributes to phenylephrine-mediated contraction in the aortae of high fat diet-induced obese mice. Biochem Biophys Res Commun 2014; 446:1179-83. [DOI: 10.1016/j.bbrc.2014.03.065] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 03/17/2014] [Indexed: 12/22/2022]
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13
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Pojoga LH, Yao TM, Opsasnick LA, Garza AE, Reslan OM, Adler GK, Williams GH, Khalil RA. Dissociation of hyperglycemia from altered vascular contraction and relaxation mechanisms in caveolin-1 null mice. J Pharmacol Exp Ther 2013; 348:260-70. [PMID: 24281385 DOI: 10.1124/jpet.113.209189] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Hyperglycemia and endothelial dysfunction are associated with hypertension, but the specific causality and genetic underpinning are unclear. Caveolin-1 (cav-1) is a plasmalemmal anchoring protein and modulator of vascular function and glucose homeostasis. Cav-1 gene variants are associated with reduced insulin sensitivity in hypertensive individuals, and cav-1(-/-) mice show endothelial dysfunction, hyperglycemia, and increased blood pressure (BP). On the other hand, insulin-sensitizing therapy with metformin may inadequately control hyperglycemia while affecting the vascular outcome in certain patients with diabetes. To test whether the pressor and vascular changes in cav-1 deficiency states are related to hyperglycemia and to assess the vascular mechanisms of metformin under these conditions, wild-type (WT) and cav-1(-/-) mice were treated with either placebo or metformin (400 mg/kg daily for 21 days). BP and fasting blood glucose were in cav-1(-/-) > WT and did not change with metformin. Phenylephrine (Phe)- and KCl-induced aortic contraction was in cav-1(-/-) < WT; endothelium removal, the nitric-oxide synthase (NOS) blocker L-NAME (N(ω)-nitro-L-arginine methyl ester), or soluble guanylate cyclase (sGC) inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) enhanced Phe contraction, and metformin blunted this effect. Acetylcholine-induced relaxation was in cav-1(-/-) > WT, abolished by endothelium removal, L-NAME or ODQ, and reduced with metformin. Nitric oxide donor sodium nitroprusside was more potent in inducing relaxation in cav-1(-/-) than in WT, and metformin reversed this effect. Aortic eNOS, AMPK, and sGC were in cav-1(-/-) > WT, and metformin decreased total and phosphorylated eNOS and AMPK in cav-1(-/-). Thus, metformin inhibits both vascular contraction and NO-cGMP-dependent relaxation but does not affect BP or blood glucose in cav-1(-/-) mice, suggesting dissociation of hyperglycemia from altered vascular function in cav-1-deficiency states.
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Affiliation(s)
- Luminita H Pojoga
- Cardiovascular Endocrine Section, Endocrinology, Diabetes and Hypertension Division (L.H.P., T.M.Y., A.E.G., G.K.A., G.H.W.), and Division of Vascular and Endovascular Surgery (L.A.O., O.M.R., R.A.K.), Brigham and Women's Hospital, and Harvard Medical School, Boston, Massachusetts
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Sahara Y, Saito SY, Ishikawa T. Involvement of nitric oxide production in the impairment of skin blood flow response to local cooling in diabetic db/db mice. Eur J Pharmacol 2013. [DOI: 10.1016/j.ejphar.2013.10.030] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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