scholarly journals Transcriptional Control of Vascular Smooth Muscle Cell Proliferation by Peroxisome Proliferator-Activated Receptor-γ: Therapeutic Implications for Cardiovascular Diseases

PPAR Research ◽  
2008 ◽  
Vol 2008 ◽  
pp. 1-11 ◽  
Author(s):  
Florence Gizard ◽  
Dennis Bruemmer

Proliferation of vascular smooth muscle cells (SMCs) is a critical process for the development of atherosclerosis and complications of procedures used to treat atherosclerotic diseases, including postangioplasty restenosis, vein graft failure, and transplant vasculopathy. Peroxisome proliferator-activated receptor (PPAR)γis a member of the nuclear hormone receptor superfamily and the molecular target for the thiazolidinediones (TZD), used clinically to treat insulin resistance in patients with type 2 diabetes. In addition to their efficacy to improve insulin sensitivity, TZD exert a broad spectrum of pleiotropic beneficial effects on vascular gene expression programs. In SMCs, PPARγis prominently upregulated during neointima formation and suppresses the proliferative response to injury of the arterial wall. Among the molecular target genes regulated by PPARγin SMCs are genes encoding proteins involved in the regulation of cell-cycle progression, cellular senescence, and apoptosis. This inhibition of SMC proliferation is likely to contribute to the prevention of atherosclerosis and postangioplasty restenosis observed in animal models and proof-of-concept clinical studies. This review will summarize the transcriptional target genes regulated by PPARγin SMCs and outline the therapeutic implications of PPARγactivation for the treatment and prevention of atherosclerosis and its complications.

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Julian Shen ◽  
Wei Wei ◽  
Xialei Wang ◽  
Jingda Yang ◽  
Lu Lu ◽  
...  

Context: Alismatis rhizome decoction (AD) exhibits antiatherosclerotic activities. The activity of AD against vascular smooth muscle cell (VSMC) proliferation remains unclear. Objective. The mechanisms and effects of AD on oxidized low-density lipoprotein (ox-LDL)-induced VSMC proliferation were explored. Materials and methods. The male SD rats were fed with AD (2.56 g/mL) or 0.9% NaCl by oral gavage 4 mL twice daily for 7 d. Then, AD-containing serum (ADcs) was collected. MTS assay was applied to measure the VSMC viability. The proliferation of VSMCs was detected by 5-bromodeoxyuridine (BrdU) immunocytochemistry. The microRNA (miRNA) profiling was performed, and the target genes of miRNAs were searched from the TargetScan 7.2 database. The expressions of matrix metalloproteinases-2/9 (MMP-2/9), cyclin D1/E, cyclin-dependent kinase inhibitor 1B (p27), extracellular regulated protein kinases 1/2 (ERK1/2), and ERK1/2 phosphorylation were examined by western blotting or quantitative reverse transcription PCR. Results. The ox-LDL-induced miR-17-92a expression promoted VSMC proliferation. AD and the ERK1/2 inhibitor U0126 (10 μmol/L) inhibited VSMC proliferation and reduced the overexpression of miR-17∼92a. AD was found to inhibit phosphorylation of ERK1/2 and reduced the expression of MMP-2/9 in VSMCs. The expression of cyclin D1/E was suppressed, and p27 was elevated following treatment with AD as well as ERK1/2 inhibitor. According to the TargetScan 7.2 database, the target genes of miR-17∼92a act on tissue inhibitors of metalloproteinases (TIMPs)-MMPs, p27/21 cyclins, and peroxisome-proliferator-activated receptor α (PPARα) ATP-binding cassette transporter (ABC) A1/G1, which are involved in the process of atherosclerosis. Conclusions. AD inhibits ox-LDL-induced VSMC proliferation via inhibiting ERK1/2 and miR-17∼92a activation. The results provide the multitarget mechanisms for application of AD in the treatment of atherosclerosis. It would be helpful to the treatment of cardiovascular and cerebral diseases.


PPAR Research ◽  
2009 ◽  
Vol 2009 ◽  
pp. 1-8 ◽  
Author(s):  
Daniela P. Foti ◽  
Francesco Paonessa ◽  
Eusebio Chiefari ◽  
Antonio Brunetti

The insulin receptor (IR) plays a crucial role in mediating the metabolic and proliferative functions triggered by the peptide hormone insulin. There is considerable evidence that abnormalities in both IR expression and function may account for malignant transformation and tumour progression in some human neoplasias, including breast cancer. PPARγis a ligand-activated, nuclear hormone receptor implicated in many pleiotropic biological functions related to cell survival and proliferation. In the last decade, PPARγagonists—besides their known action and clinical use as insulin sensitizers—have proved to display a wide range of antineoplastic effects in cells and tissues expressing PPARγ, leading to intensive preclinical research in oncology. PPARγand activators affect tumours by different mechanisms, involving cell proliferation and differentiation, apoptosis, antiinflammatory, and antiangiogenic effects. We recently provided evidence that PPARγand agonists inhibit IR by non canonical, DNA-independent mechanisms affecting IR gene transcription. We conclude that IR may be considered a new PPARγ“target” gene, supporting a potential use of PPARγagonists as antiproliferative agents in selected neoplastic tissues that overexpress the IR.


2015 ◽  
Vol 36 (6) ◽  
pp. 2466-2479 ◽  
Author(s):  
XiaoLe Xu ◽  
Mengzi He ◽  
Tingting Liu ◽  
Yi Zeng ◽  
Wei Zhang

Background/Aims: salusin-ß is considered to be a potential pro-atherosclerotic factor. Regulation and function of vascular smooth muscle cells (VSMCs) are important in the progression of atherosclerosis. Peroxisome proliferator-activated receptor gamma (PPARγ) exerts a vascular protective role beyond its metabolic effects. Salusin-ß has direct effects on VSMCs. The aim of the present study was to assess the effect of salusin-ß on PPARγ gene expression in primary cultured rat VSMCs. Methods: Western blotting analysis, real-time PCR and transient transfection approach were used to determine expression of target proteins. Specific protein knockdown was performed with siRNA transfection. Cell proliferation was determined by 5-bromo-2'-deoxyuridine incorporation. The levels of inflammation indicators interleukin-6 (IL-6) and tumor necrosis factor-a (TNF-a) were determined using enzyme-linked immunosorbent assay. Results: Salusin-ß negatively regulated PPARγ gene expression at protein, mRNA and gene promoter level in VSMCs. The inhibitory effect of salusin-ß on PPARγ gene expression contributed to salusin-ß-induced VSMCs proliferation and inflammation in vitro. IγBa-NF-γB activation, but not NF-γB p50 or p65, mediated the salusin-ß-induced inhibition of PPARγ gene expression. Salusin-ß induced nuclear translocation of histone deacetylase 3 (HDAC3). HDAC3 siRNA prevented salusin-ß-induced PPARγ reduction. Nuclear translocation of HDAC3 in response to salusin-ß was significantly reversed by an IγBa inhibitor BAY 11-7085. Furthermore, IγBa-HDAC3 complex was present in the cytosol of VSMCs but interrupted after salusin-ß treatment. Conclusion: IγBa-HDAC3 pathway may contribute to salusin-ß-induced inhibition of PPARγ gene expression in VSMCs.


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