1
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Zhao K, Wu T, Yang C, Pan H, Xu T, Zhang J, Guo X, Tu J, Zhang D, Kong X, Zhou B, Sun W. Low-intensity pulsed ultrasound prevents angiotensin II-induced aortic smooth muscle cell phenotypic switch via hampering miR-17-5p and enhancing PPAR-γ. Eur J Pharmacol 2021; 911:174509. [PMID: 34547245 DOI: 10.1016/j.ejphar.2021.174509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 09/14/2021] [Accepted: 09/15/2021] [Indexed: 10/20/2022]
Abstract
Vascular events can trigger a pathological phenotypic switch in vascular smooth muscle cells (VSMCs), decreasing and disrupting the plasticity and diversity of vascular networks. The development of novel therapeutic approaches is necessary to prevent these changes. We aimed to investigate the effects and associated mechanisms of low-intensity pulsed ultrasound (LIPUS) irradiation on the angiotensin II (AngII)-induced phenotypic switch in VSMCs. In vivo, AngII was infused subcutaneously for 4 weeks to stimulate vascular remodeling in mice, and LIPUS irradiation was applied for 20 min every 2 days for 4 weeks. In vitro, cultured rat aortic VSMCs (RAVSMCs) were pretreated once with LIPUS irradiation for 20 min before 48-h AngII stimulation. Our results showed that LIPUS irradiation prevents AngII-induced vascular remodeling of the whole wall artery without discriminating between adventitia and media in vivo and RAVSMC phenotypic switching in vitro. LIPUS irradiation downregulated miR-17-5p expression and upregulated peroxisome proliferator-activated receptor gamma (PPAR-γ) expression. The PPAR-γ activator rosiglitazone could mimic the favorable effects of LIPUS irradiation on AngII-treated RAVSMCs. In contrast, GW9662 could impede the LIPUS-mediated downregulation of RAVSMC proliferation and inflammation under AngII stimulation conditions in vivo and in vitro. Also, the miR-17-5p agomir has the same effects as GW9662 in vitro. Besides, the inhibitory effects of GW9662 against the anti-remodeling effects of LIPUS irradiation in AngII-induced RAVSMCs could be blocked by pretreatment with the miR-17-5p antagomir. Overall, LIPUS irradiation prevents AngII-induced RAVSMCs phenotypic switching through hampering miR-17-5p and enhancing PPAR-γ, suggesting a new approach for the treatment of vascular disorders.
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MESH Headings
- Animals
- MicroRNAs/genetics
- MicroRNAs/metabolism
- PPAR gamma/metabolism
- PPAR gamma/genetics
- Angiotensin II/pharmacology
- Male
- Rats
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/radiation effects
- Muscle, Smooth, Vascular/cytology
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/metabolism
- Myocytes, Smooth Muscle/radiation effects
- Phenotype
- Ultrasonic Waves
- Aorta/drug effects
- Aorta/metabolism
- Aorta/cytology
- Vascular Remodeling/drug effects
- Vascular Remodeling/radiation effects
- Cells, Cultured
- Mice
- Rats, Sprague-Dawley
- Mice, Inbred C57BL
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Affiliation(s)
- Kun Zhao
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, Jiangsu, China
| | - Tingting Wu
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, Jiangsu, China
| | - Chuanxi Yang
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, Jiangsu, China; Department of Cardiology, Yangpu Hospital, Tongji University School of Medicine, Shanghai, 200082, China
| | - Haotian Pan
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, Jiangsu, China
| | - Tianhua Xu
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, Jiangsu, China
| | - Jing Zhang
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, Jiangsu, China
| | - Xiasheng Guo
- Key Laboratory of Modern Acoustics, Department of Physics, Collaborative Innovation Center of Advanced Microstructure, Nanjing University, Nanjing, Jiangsu, 210093, China
| | - Juan Tu
- Key Laboratory of Modern Acoustics, Department of Physics, Collaborative Innovation Center of Advanced Microstructure, Nanjing University, Nanjing, Jiangsu, 210093, China
| | - Dong Zhang
- Key Laboratory of Modern Acoustics, Department of Physics, Collaborative Innovation Center of Advanced Microstructure, Nanjing University, Nanjing, Jiangsu, 210093, China
| | - Xiangqing Kong
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, Jiangsu, China
| | - Bin Zhou
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, Jiangsu, China; Department of Genetics, Pediatrics and Medicine Cardiology, Wilf Cardiovascular Research Institute, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Wei Sun
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, Jiangsu, China.
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Krishnappa M, Patil K, Parmar K, Trivedi P, Mody N, Shah C, Faldu K, Maroo S, Parmar D. Effect of saroglitazar 2 mg and 4 mg on glycemic control, lipid profile and cardiovascular disease risk in patients with type 2 diabetes mellitus: a 56-week, randomized, double blind, phase 3 study (PRESS XII study). Cardiovasc Diabetol 2020; 19:93. [PMID: 32560724 PMCID: PMC7305598 DOI: 10.1186/s12933-020-01073-w] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 06/16/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND The potential for PPAR agonists to positively affect risk of cardiovascular disease in patients with type 2 diabetes (T2DM) is of persistent attention. The PRESS XII study primarily aimed to evaluate the efficacy and safety of saroglitazar (2 mg and 4 mg) as compared to pioglitazone 30 mg on glycemic control in patients with type 2 diabetes mellitus. METHODS In this randomized double-blind study, patients with T2DM [glycosylated hemoglobin (HbA1c) ≥ 7.5%] were enrolled from 39 sites in India. Patients received once-daily doses of either saroglitazar or pioglitazone (1:1:1 allocation ratio) for a total of 24 weeks. Patients were continued in a double blind extension period for an additional 32 weeks. Efficacy evaluations of glycemic parameters [HbA1c (Primary endpoint at week 24), FPG and PPG] and other lipid parameters (TG, LDL-C, VLDL-C, HDL-C, TC, Non HDL-C, Apo A1 and Apo B) were conducted at week 12, 24 and 56 and compared to the baseline levels. The efficacy analyses were performed by using paired t-test and ANCOVA model. RESULTS A total of 1155 patients were enrolled in this study. The baseline characteristics were similar between the three treatment groups. The within group mean (± SD) change in HbA1c (%) from baseline of the saroglitazar (2 mg and 4 mg) and pioglitazone treatment groups at week 24 were: - 1.38 ± 1.99 for saroglitazar 2 mg; - 1.47 ± 1.92 for saroglitazar 4 mg and - 1.41 ± 1.86 for pioglitazone, respectively. Statistically significant reduction from baseline in HbA1c was observed in each treatment group at week 24 with p-value < 0.016. There was a significant reduction in TG, LDL-C, VLDL-C, TC and Non HDL-C with a significant increase in HDL-C from baseline levels (< 0.016). Most of the AE's were 'mild' to 'moderate' in severity and were resolved by the completion of the study. CONCLUSIONS Saroglitazar effectively improved glycemic control and lipid parameters over 56 weeks in patients of T2DM receiving background metformin therapy and has a promising potential to reduce the cardiovascular risk in T2DM patients. Trial registration CTRI/2015/09/006203, dated 22/09/2015.
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Affiliation(s)
- Manjunath Krishnappa
- Zydus Research Centre, Clinical R & D, Cadila Healthcare Limited, Sarkhej-Bavla N. H. No. 8 A, Moraiya, Ahmedabad, Gujarat, 382213, India.
| | - Kishor Patil
- Zydus Research Centre, Clinical R & D, Cadila Healthcare Limited, Sarkhej-Bavla N. H. No. 8 A, Moraiya, Ahmedabad, Gujarat, 382213, India
| | - Krupi Parmar
- Zydus Research Centre, Clinical R & D, Cadila Healthcare Limited, Sarkhej-Bavla N. H. No. 8 A, Moraiya, Ahmedabad, Gujarat, 382213, India
| | - Purav Trivedi
- Zydus Research Centre, Clinical R & D, Cadila Healthcare Limited, Sarkhej-Bavla N. H. No. 8 A, Moraiya, Ahmedabad, Gujarat, 382213, India
| | - Nirali Mody
- Zydus Research Centre, Clinical R & D, Cadila Healthcare Limited, Sarkhej-Bavla N. H. No. 8 A, Moraiya, Ahmedabad, Gujarat, 382213, India
| | - Chintan Shah
- Zydus Research Centre, Clinical R & D, Cadila Healthcare Limited, Sarkhej-Bavla N. H. No. 8 A, Moraiya, Ahmedabad, Gujarat, 382213, India
| | - Khushboo Faldu
- Zydus Research Centre, Clinical R & D, Cadila Healthcare Limited, Sarkhej-Bavla N. H. No. 8 A, Moraiya, Ahmedabad, Gujarat, 382213, India
| | - Sanjay Maroo
- Zydus Research Centre, Clinical R & D, Cadila Healthcare Limited, Sarkhej-Bavla N. H. No. 8 A, Moraiya, Ahmedabad, Gujarat, 382213, India
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3
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Liu K, Zhou W, Chen H, Pan H, Sun X, You Q. Autologous vein graft stenosis inhibited by orphan nuclear receptor Nur77-targeted siRNA. Vascul Pharmacol 2015; 73:64-70. [PMID: 26276525 DOI: 10.1016/j.vph.2015.08.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Revised: 07/30/2015] [Accepted: 08/09/2015] [Indexed: 10/23/2022]
Abstract
Neointimal hyperplasia plays an important role in autologous vein graft stenosis, and orphan receptor TR3/nur77 (Nur77) might play an essential role, but the mechanisms are still unclear. Here, we investigated the function of Nur77 in autologous vein graft stenosis. Rat vascular smooth muscle cell A7r5 was used for evaluating the function of Nur77 and screen siRNAs. Meanwhile, rat vein graft models were constructed for investigating the stenosis inhibition effects of Nur77-targeted siRNAs. The mRNA and protein levels of Nur77 were highly expressed in A7r5 cell, and could be significantly inhibited by the pre-designed siRNAs; the proliferation of A7r5 cell was also inhibited by the siRNAs. Furthermore, the intimal thickening in rat vein graft models was inhibited when knocking down the expression of Nur77 by siRNA. The results suggest that Nur77-targeted siRNA can inhibit autologous vein graft stenosis, Nur77 may play an important role in autologous vein graft stenosis, and Nur77 targeted siRNAs may be a therapy method for anti-stenosis of autologous vein graft.
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Affiliation(s)
- Kun Liu
- Department of Cardiothoracic Surgery, Affiliated Hospital of Nantong University, Nantong 226001, China
| | - Wen Zhou
- Department of Cardiothoracic Surgery, Affiliated Hospital of Nantong University, Nantong 226001, China
| | | | - Haiyan Pan
- Department of Cardiology, Affiliated Hospital of Nantong University, Nantong 226001, China
| | - Xiaohui Sun
- Department of Cardiology, Nantong Geriatric Rehabilitation Hosptial, Nantong 226001, China
| | - Qingsheng You
- Department of Cardiothoracic Surgery, Affiliated Hospital of Nantong University, Nantong 226001, China.
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4
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Zhang HG, Cheng YQ, Liu Y, Zhou JZ, Jia Y, Wang XQ, Li XH. Gαq-protein carboxyl terminus imitation polypeptide GCIP-27 attenuates proliferation of vascular smooth muscle cells and vascular remodeling in spontaneously hypertensive rats. Biol Pharm Bull 2012; 34:1527-32. [PMID: 21963491 DOI: 10.1248/bpb.34.1527] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Gq-protein is located at the convergent point in signal transduction pathways leading to vascular remodeling. The carboxyl terminus of Gα-subunit plays a vital role in G-protein-receptor interaction. The present study was designed to explore the effects of a synthetic Gαq carboxyl terminus imitation peptide, namely GCIP-27, on vascular smooth muscle cells (VSMC) in vitro and vascular remodeling in spontaneous hypertensive rats (SHR). Hyperplasia and hypertrophy of VSMC wre determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, [(3)H]-thymidine and [(3)H]-leucine incorporation, and [Ca(2+)](i) was measured with Fluo-3/AM staining. Systolic blood pressure (SBP), the ratio of media thickness to lumen diameter (MT/LD) of aorta, collagen content, and phospholipase C activity in aorta were measured in SHR. GCIP-27 (3-100 µg/l) significantly decreased proliferation activity, protein content, incorporation of [(3)H]-thymidine and [(3)H]-leucine, and [Ca(2+)](i) level in VSMC. SBP, MT/LD, collagen content, and phospholipase C activity in aorta of SHR were decreased significantly in GCIP-27 (7, 20, 60 µg/kg)-treated groups and losartan (6 mg/kg) group compared with vehicle group. In conclusion, GCIP-27 could inhibit vascular remodeling effectively in vitro and in vivo.
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Affiliation(s)
- Hai-Gang Zhang
- Institute of Materia Medica and Department of Pharmaceutics, College of Pharmacy, Third Military Medical University, P.R. China
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5
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Zhang LL, Gao CY, Fang CQ, Wang YJ, Gao D, Yao GE, Xiang J, Wang JZ, Li JC. PPAR attenuates intimal hyperplasia by inhibiting TLR4-mediated inflammation in vascular smooth muscle cells. Cardiovasc Res 2011; 92:484-493. [DOI: 10.1093/cvr/cvr238] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 08/30/2023] Open
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6
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Gong K, Xing D, Li P, Aksut B, Ambalavanan N, Yang Q, Nozell SE, Oparil S, Chen YF. Hypoxia induces downregulation of PPAR-γ in isolated pulmonary arterial smooth muscle cells and in rat lung via transforming growth factor-β signaling. Am J Physiol Lung Cell Mol Physiol 2011; 301:L899-907. [PMID: 21926264 PMCID: PMC3233825 DOI: 10.1152/ajplung.00062.2011] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Accepted: 09/05/2011] [Indexed: 11/22/2022] Open
Abstract
Chronic hypoxia activates transforming growth factor-β (TGF-β) signaling and leads to pulmonary vascular remodeling. Pharmacological activation of peroxisome proliferator-activated receptor-γ (PPAR-γ) has been shown to prevent hypoxia-induced pulmonary hypertension and vascular remodeling in rodent models, suggesting a vasoprotective effect of PPAR-γ under chronic hypoxic stress. This study tested the hypothesis that there is a functional interaction between TGF-β/Smad signaling pathway and PPAR-γ in isolated pulmonary artery small muscle cells (PASMCs) under hypoxic stress. We observed that chronic hypoxia led to a dramatic decrease of PPAR-γ protein expression in whole lung homogenates (rat and mouse) and hypertrophied pulmonary arteries and isolated PASMCs. Using a transgenic model of mouse with inducible overexpression of a dominant-negative mutant of TGF-β receptor type II, we demonstrated that disruption of TGF-β pathway significantly attenuated chronic hypoxia-induced downregulation of PPAR-γ in lung. Similarly, in isolated rat PASMCs, antagonism of TGF-β signaling with either a neutralizing antibody to TGF-β or the selective TGF-β receptor type I inhibitor SB431542 effectively attenuated hypoxia-induced PPAR-γ downregulation. Furthermore, we have demonstrated that TGF-β1 treatment suppressed PPAR-γ expression in PASMCs under normoxia condition. Chromatin immunoprecipitation analysis showed that TGF-β1 treatment significantly increased binding of Smad2/3, Smad4, and the transcriptional corepressor histone deacetylase 1 to the PPAR-γ promoter in PASMCs. Conversely, treatment with the PPAR-γ agonist rosiglitazone attenuated TGF-β1-induced extracellular matrix molecule expression and growth factor in PASMCs. These data provide strong evidence that activation of TGF-β/Smad signaling, via transcriptional suppression of PPAR-γ expression, mediates chronic hypoxia-induced downregulation of PPAR-γ expression in lung.
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MESH Headings
- Animals
- Cell Hypoxia
- Cell Movement
- Cells, Cultured
- Down-Regulation
- Extracellular Matrix/metabolism
- Histone Deacetylase 1/metabolism
- Hypoxia/genetics
- Hypoxia/metabolism
- Lung/blood supply
- Lung/metabolism
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/pathology
- Myocytes, Smooth Muscle/metabolism
- PPAR gamma/agonists
- PPAR gamma/genetics
- PPAR gamma/metabolism
- Protein Serine-Threonine Kinases/antagonists & inhibitors
- Protein Serine-Threonine Kinases/genetics
- Protein Serine-Threonine Kinases/metabolism
- Pulmonary Artery/metabolism
- Pulmonary Artery/pathology
- Rats
- Rats, Sprague-Dawley
- Receptor, Transforming Growth Factor-beta Type I
- Receptor, Transforming Growth Factor-beta Type II
- Receptors, Transforming Growth Factor beta/antagonists & inhibitors
- Receptors, Transforming Growth Factor beta/genetics
- Receptors, Transforming Growth Factor beta/metabolism
- Signal Transduction
- Smad Proteins/metabolism
- Transcription, Genetic
- Transforming Growth Factor beta/metabolism
- Transforming Growth Factor beta/pharmacology
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Affiliation(s)
- Kaizheng Gong
- Vascular Biology and Hypertension Program, Department of Medicine, University of Alabama at Birmingham, 35294, USA
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7
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Chen CH, Lu ML, Kuo PH, Chen PY, Chiu CC, Kao CF, Huang MC. Gender differences in the effects of peroxisome proliferator-activated receptor γ2 gene polymorphisms on metabolic adversity in patients with schizophrenia or schizoaffective disorder. Prog Neuropsychopharmacol Biol Psychiatry 2011; 35:239-45. [PMID: 21095215 DOI: 10.1016/j.pnpbp.2010.11.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2010] [Revised: 10/27/2010] [Accepted: 11/08/2010] [Indexed: 11/24/2022]
Abstract
OBJECTIVE Metabolic syndrome (MS) is a major health problem in schizophrenic patients. Peroxisome proliferator-activated receptor γ2 (PPARγ2) is one of the candidate genes responsible for the liability to metabolic problems. In this study, we investigated the effect of the PPARγ2 gene Pro12Ala and C161T polymorphisms on metabolic adversities in patients with schizophrenia or schizoaffective disorder. METHODS Metabolic profiles and PPARγ2 gene polymorphisms were determined in 600 patients (309 men and 291 women) with a clinical diagnosis of schizophrenia or schizoaffective disorder. Metabolic indices and components of MS were compared between patients with different Pro12Ala or C161T genotypes. RESULTS In the whole population, the allele frequency of 12Ala and 161T was 4.4% and 24.7% respectively. Both polymorphisms had no significant effect on obesity or metabolic-related traits. However, following gender stratification of the data, we found female 12Ala allele carriers were at greater risk of developing abdominal obesity (OR = 4.0, 95% CI = 1.1-14.2, p = 0.04) and hypertension (OR=2.9, 95% CI = 1.2-7.4, p = 0.02) than female 12Ala allele non-carriers. Male 161T allele carriers had lower insulin levels (p = 0.02) and lower high-density lipoprotein cholesterol (HDL-C) (p = 0.05) levels than male 161T allele non-carriers. Moreover, female 161T allele carriers had higher body weight (p = 0.04), waist circumference (p = 0.05), and systolic blood pressure (p = 0.01), and were at greater risk of developing hypertension (OR = 2.0, 95% CI = 1.1-3.5, p = 0.02). Haplotype analyses showed that PPARγ2 gene polymorphisms were significantly associated with HDL-C level in men and blood pressure in women. CONCLUSIONS We did not find an association of PPARγ2 gene polymorphisms with MS or obesity in our schizophrenia sample. But further analyses by gender stratification revealed gender-specific differences in the effect of different PPARγ2 genotypes on certain metabolic adversities in these patients.
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Affiliation(s)
- Chun-Hsin Chen
- Department of Psychiatry, Taipei Medical University-Wan Fang Hospital, Taipei, Taiwan
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8
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The role of peroxisome proliferator-activated receptor gamma in blood pressure regulation. Curr Hypertens Rep 2010; 11:239-45. [PMID: 19602323 DOI: 10.1007/s11906-009-0041-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Peroxisome proliferator-activated receptor-gamma (PPARgamma) is a member of the nuclear hormone receptor superfamily. It is expressed in adipocytes, immune cells, and cardiovascular cells that include cardiomyocytes, endothelial cells, and smooth muscle cells. PPARgamma plays a role in regulating cellular anti-inflammatory responses and is a mediator of insulin sensitization induced by thiazolidinediones, which also can reduce elevated blood pressure both clinically and experimentally. As a result, research regarding the role of PPARgamma in blood pressure homeostasis is ongoing. Recent studies have demonstrated that increases or decreases in blood pressure phenotype may be PPARgamma-dependent and involve a number of different signaling pathways. Furthermore, studies using PPARgamma mutant transgenic and knockout animal models provide further evidence regarding a role for endothelial-cell and vascular smooth muscle-cell PPARgamma in blood pressure regulation. However, there is a need for further research regarding PPARgamma--mediated mechanisms involved in maintaining physiologic control of blood pressure.
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9
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Zhang L, Xie P, Wang J, Yang Q, Fang C, Zhou S, Li J. Impaired peroxisome proliferator-activated receptor-gamma contributes to phenotypic modulation of vascular smooth muscle cells during hypertension. J Biol Chem 2010; 285:13666-77. [PMID: 20212046 DOI: 10.1074/jbc.m109.087718] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The phenotypic modulation of vascular smooth muscle cells (VSMCs) plays a pivotal role in hypertension-induced vascular changes including vascular remodeling. The precise mechanisms underlying VSMC phenotypic modulation remain elusive. Here we test the role of peroxisome proliferator-activated receptor (PPAR)-gamma in the VSMC phenotypic modulation during hypertension. Both spontaneously hypertensive rat (SHR) aortas and SHR-derived VSMCs exhibited reduced PPAR-gamma expression and excessive VSMC phenotypic modulation identified by reduced contractile proteins, alpha-smooth muscle actin (alpha-SMA) and smooth muscle 22alpha (SM22alpha), and enhanced proliferation and migration. PPAR-gamma overexpression rescued the expression of alpha-SMA and SM22alpha, and inhibited the proliferation and migration in SHR-derived VSMCs. In contrast, PPAR-gamma silencing exerted the opposite effect. Activating PPAR-gamma using rosiglitazone in vivo up-regulated aortic alpha-SMA and SM22alpha expression and attenuated aortic remodeling in SHRs. Increased activation of phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling was observed in SHR-derived VSMCs. PI3K inhibitor LY294002 rescued the impaired expression of contractile proteins, and inhibited proliferation and migration in VSMCs from SHRs, whereas constitutively active PI3K mutant had the opposite effect. Overexpression or silencing of PPAR-gamma inhibited or excited PI3K/Akt activity, respectively. LY294002 counteracted the PPAR-gamma silencing induced proliferation and migration in SHR-derived VSMCs, whereas active PI3K mutant had the opposite effect. In contrast, reduced proliferation and migration by PPAR-gamma overexpression were reversed by the active PI3K mutant, and further inhibited by LY294002. We conclude that PPAR-gamma inhibits VSMC phenotypic modulation through inhibiting PI3K/Akt signaling. Impaired PPAR-gamma expression is responsible for VSMC phenotypic modulation during hypertension. These findings highlight an attractive therapeutic target for hypertension-related vascular disorders.
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Affiliation(s)
- Lili Zhang
- Department of Neurology, Daping Hospital, Third Military Medical University, Chongqing 400042, China
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10
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Abstract
Peroxisome proliferator-activated receptors (PPARs) belong to the nuclear hormone-receptor superfamily. Originally cloned in 1990, PPARs were found to be mediators of pharmacologic agents that induce hepatocyte peroxisome proliferation. PPARs also are expressed in cells of the cardiovascular system. PPAR gamma appears to be highly expressed during atherosclerotic lesion formation, suggesting that increased PPAR gamma expression may be a vascular compensatory response. Also, ligand-activated PPAR gamma decreases the inflammatory response in cardiovascular cells, particularly in endothelial cells. PPAR alpha, similar to PPAR gamma, also has pleiotropic effects in the cardiovascular system, including antiinflammatory and antiatherosclerotic properties. PPAR alpha activation inhibits vascular smooth muscle proinflammatory responses, attenuating the development of atherosclerosis. However, PPAR delta overexpression may lead to elevated macrophage inflammation and atherosclerosis. Conversely, PPAR delta ligands are shown to attenuate the pathogenesis of atherosclerosis by improving endothelial cell proliferation and survival while decreasing endothelial cell inflammation and vascular smooth muscle cell proliferation. Furthermore, the administration of PPAR ligands in the form of TZDs and fibrates has been disappointing in terms of markedly reducing cardiovascular events in the clinical setting. Therefore, a better understanding of PPAR-dependent and -independent signaling will provide the foundation for future research on the role of PPARs in human cardiovascular biology.
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Affiliation(s)
- Milton Hamblin
- Cardiovascular Center, Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor, Michigan 48109, USA
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11
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Seto SW, Lam TY, Leung GPH, Au ALS, Ngai SM, Chan SW, Kwan YW. Comparison of vascular relaxation, lipolysis and glucose uptake by peroxisome proliferator-activated receptor-gamma activation in +db/+m and +db/+db mice. Eur J Pharmacol 2007; 572:40-8. [PMID: 17603034 DOI: 10.1016/j.ejphar.2007.05.070] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2007] [Revised: 05/22/2007] [Accepted: 05/23/2007] [Indexed: 11/21/2022]
Abstract
In this study, we determined the in vitro effect of peroxisome proliferator-activated receptor-gamma (PPAR-gamma) activation on the aortic relaxation, lipolysis and insulin-induced [(3)H]-glucose uptake of the abdominal (omental) adipocytes of the non-diabetic (+db/+m) and obese/diabetic (+db/+db) mice. The expression of PPAR-gamma (mRNA and protein) in aorta and adipose tissues was evaluated and compared. Cumulative application of ciglitazone, pioglitazone and troglitazone (PPAR-gamma agonists) caused a concentration-dependent aortic relaxation (sensitive to 2-chloro-5-nitro-N-phenylbenzamide (GW9662) (1 microM, a selective PPAR-gamma antagonist) and N(omega)-nitro-l-arginine methyl ester (l-NAME) (20 microM, a nitric oxide synthase inhibitor)) with a maximum relaxation of approximately 30% (3 microM) in +db/+m mice, whereas no relaxation was observed in +db/+db mice. All PPAR-gamma agonists examined did not alter the basal lipolysis of both species, but forskolin caused a concentration-dependent lipolysis, with a greater magnitude observed in +db/+m mice. Insulin (0.1 and 1 microM) caused an enhancement of [(3)H]-glucose uptake into adipocytes with a greater magnitude in +db/+m mice. In contrast, none of the PPAR-gamma agonists tested (0.1, 1 and 10 microM) altered the basal and the insulin (0.1 microM)-induced [(3)H]-glucose uptake into adipocytes of both species. In addition, there was no difference in PPAR-gamma expression (mRNA and protein) in the aorta and adipose tissues between the species. In conclusion, our results demonstrate that PPAR-gamma is present in the abdominal (omental) adipose tissue and thoracic aorta. An acute activation of PPAR-gamma produced a small ( approximately 30%) aortic relaxation (nitric oxide/endothelium-dependent) of +db/+m mice. However, all PPAR-gamma agonists examined have no acute effect on lipolysis and the insulin-induced glucose uptake into adipocytes of both +db/+m and +db/+db mice.
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MESH Headings
- Abdominal Fat/metabolism
- Adipocytes/drug effects
- Adipocytes/metabolism
- Animals
- Aorta, Thoracic/drug effects
- Aorta, Thoracic/physiopathology
- Carbohydrate Metabolism/drug effects
- Chromans/pharmacology
- Diabetes Mellitus, Type 2/metabolism
- Diabetes Mellitus, Type 2/physiopathology
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/physiopathology
- Female
- Glucose/metabolism
- Hypoglycemic Agents/pharmacology
- In Vitro Techniques
- Insulin/pharmacology
- Lipid Metabolism
- Lipolysis/drug effects
- Mice
- Mice, Inbred C57BL
- Mice, Mutant Strains
- Obesity/metabolism
- Obesity/physiopathology
- PPAR gamma/agonists
- PPAR gamma/biosynthesis
- Pioglitazone
- RNA, Messenger/agonists
- RNA, Messenger/biosynthesis
- Thiazolidinediones/pharmacology
- Troglitazone
- Vasodilation/drug effects
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Affiliation(s)
- Sai Wang Seto
- Department of Pharmacology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong
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12
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Pandey NR, Benkirane K, Amiri F, Schiffrin EL. Effects of PPAR-γ Knock-down and Hyperglycemia on Insulin Signaling in Vascular Smooth Muscle Cells From Hypertensive Rats. J Cardiovasc Pharmacol 2007; 49:346-54. [PMID: 17577098 DOI: 10.1097/fjc.0b013e31804654d7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Peroxisome proliferator-activated receptor (PPAR)-gamma, a target in the treatment of diabetes, improves insulin sensitivity and exerts cardiovascular protective effects by mechanisms that are not completely elucidated. To investigate underlying molecular mechanisms responsible for PPAR-gamma-associated vascular insulin signaling in hypertension, we tested whether PPAR-gamma downregulation in vascular smooth muscle cells (VSMC) from WKY and SHRSP rats would decrease insulin signaling and glucose uptake and whether this response would be worsened by hyperglycemia to a greater extent in VSMC of hypertensive origin. Passaged mesenteric artery VSMC grown in euglycemic (5.5 mmol/L) or hyperglycemic media (25.0 mmol/L) were treated with PPAR-gamma-siRNA (5 nmol/L), PPAR-gamma antagonist (GW-9662, 10 micromol/L), or PPAR-gamma activator (rosiglitazone, 10 micromol/L) in the presence or absence of insulin (100 nmol/L). Immunoblotting revealed that hyperglycemia and PPAR-gamma inhibition significantly (P < 0.001) decreased insulin-stimulated insulin receptor (IR)-beta, Akt, and glycogen synthase kinase (GSK)-3beta phosphorylation, whereas phosphotyrosine phosphatase (PTP)-1B expression was increased in VSMC from both strains. These effects were more pronounced in SHRSP under hyperglycemia. Rosiglitazone tended to increase insulin-mediated IR-beta, Akt, and GSK-3beta phosphorylation in VSMC from both strains, whereas insulin-induced PTP-1B expression was reduced by hyperglycemia. Insulin-stimulated GLUT-4 expression and glucose transport were attenuated by hyperglycemia in both VSMC. These data suggest that PPAR-gamma inhibition results in decreased insulin signaling, particularly in SHR, in an IR-beta phosphorylation-dependent manner.
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MESH Headings
- Animals
- Apoptosis/drug effects
- Blotting, Western
- Cell Cycle/drug effects
- Cell Survival/drug effects
- Cells, Cultured
- Down-Regulation
- Electrophoretic Mobility Shift Assay
- Flow Cytometry
- Gene Silencing
- Glucose/metabolism
- Glucose/pharmacology
- Glucose Transporter Type 4/metabolism
- Hypertension/metabolism
- Insulin/metabolism
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/pathology
- PPAR gamma/antagonists & inhibitors
- PPAR gamma/genetics
- RNA, Small Interfering/genetics
- Rats
- Rats, Inbred SHR
- Rats, Inbred WKY
- Transfection
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Affiliation(s)
- Nihar R Pandey
- Hypertension and Vascular Research Unit, Lady Davis Institute for Medical Research, Sir Mortimer B. Davis-Jewish General Hospital, Montreal, Quebec, Canada
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13
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Kim HJ, Woo IS, Kang ES, Eun SY, Kim HJ, Lee JH, Chang KC, Kim JH, Seo HG. Identification of a truncated alternative splicing variant of human PPARγ1 that exhibits dominant negative activity. Biochem Biophys Res Commun 2006; 347:698-706. [PMID: 16842753 DOI: 10.1016/j.bbrc.2006.06.147] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2006] [Accepted: 06/23/2006] [Indexed: 12/31/2022]
Abstract
We have identified a novel variant of human peroxisome proliferator-activated receptor gamma (hPPARgamma), derived from insertion of a novel exon 3'. Insertion leads to the introduction of a premature stop codon, resulting in the formation of a truncated splice variant of PPARgamma1 (PPARgamma1(tr)). Western blot analysis confirmed the presence of PPARgamma1(tr) in tumor-derived cell lines. Although PPARgamma1(tr) interfered with transcriptional activity of wild-type PPARgamma1 (PPARgamma1(wt)), activity could be rescued by cotransfection with a vector expressing p300. Overexpression of PPARgamma1(tr) protein in CHO cells greatly enhanced their proliferation and anchorage-independent colony growth on soft agar. These data demonstrate that PPARgamma1(tr) is an important physiologic isoform of PPARgamma that modulates cellular functions of PPARgamma1(wt).
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Affiliation(s)
- Hyo Jung Kim
- Department of Pharmacology, Gyeongsang Institute of Health Science, College of Medicine, National University, Jinju, Republic of Korea
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