scholarly journals LncRNA HSPA7 in human atherosclerotic plaques sponges miR-223 and promotes the proinflammatory vascular smooth muscle cell transition

Author(s):  
Soo-jin Ann ◽  
Hyoeun Bang ◽  
Chan Joo Lee ◽  
Jaewon Oh ◽  
Sungha Park ◽  
...  

AbstractAlthough there are many genetic loci in noncoding regions associated with vascular disease, studies on long noncoding RNAs (lncRNAs) discovered from human plaques that affect atherosclerosis have been highly limited. We aimed to identify and functionally validate a lncRNA using human atherosclerotic plaques. Human aortic samples were obtained from patients who underwent aortic surgery, and tissues were classified according to atherosclerotic plaques. RNA was extracted and analyzed for differentially expressed lncRNAs in plaques. Human aortic smooth muscle cells (HASMCs) were stimulated with oxidized low-density lipoprotein (oxLDL) to evaluate the effect of the identified lncRNA on the inflammatory transition of the cells. Among 380 RNAs differentially expressed between the plaque and control tissues, lncRNA HSPA7 was selected and confirmed to show upregulated expression upon oxLDL treatment. HSPA7 knockdown inhibited the migration of HASMCs and the secretion and expression of IL-1β and IL-6; however, HSPA7 knockdown recovered the oxLDL-induced reduction in the expression of contractile markers. Although miR-223 inhibition promoted the activity of Nf-κB and the secretion of inflammatory proteins such as IL-1β and IL-6, HSPA7 knockdown diminished these effects. The effects of miR-223 inhibition and HSPA7 knockdown were also found in THP-1 cell-derived macrophages. The impact of HSPA7 on miR-223 was mediated in an AGO2-dependent manner. HSPA7 is differentially increased in human atheroma and promotes the inflammatory transition of vascular smooth muscle cells by sponging miR-223. For the first time, this study elucidated the molecular mechanism of action of HSPA7, a lncRNA of previously unknown function, in humans.

2008 ◽  
Vol 100 (07) ◽  
pp. 119-126 ◽  
Author(s):  
María González-Díez ◽  
Cristina Rodríguez ◽  
Lina Badimon ◽  
José Martínez-González

SummaryProstacyclin (PGI2) is an important regulator of vascular homeostasis. Our goal was to analyze the role of sphingosine 1-phosphate (S1P) and its receptors in the up-regulation of cyclooxygenase-2 (Cox-2) induced by HDL in human vascular smooth muscle cells (VSMC). S1P induces Cox-2 expression in a time-and dose-dependent manner at concentrations (0.02–1 µM) compatible with those present in physiological HDL levels. The effect was mimicked by dihydro-S1P (DhS1P), a S1P derivative that only acts through cell surface S1P receptors. Desensitiz-ation of S1P receptors with S1P (or DhS1P) abolished HDL-induced Cox-2 up-regulation and PGI2 release. Inhibition of S1P receptors by suramin (inhibitor of S1P3), JTE013 (inhibitor of S1P2) or VPC23019 (inhibitor of S1P1 and S1P3) reduced the up-regulation of Cox-2 induced by HDL and S1P. The combination of suramin and JTE013 increased the inhibitory effect compared to that observed in cells treated with each inhibitor alone. siRNA against S1P2 or S1P3 significantly reduced the ability of HDL and S1P to up-regulate Cox-2. Simvastatin induced over-expression of S1P3 and potentiated the induction of Cox-2 expression produced by HDL (or S1P). Finally, suramin, JTE013 and VPC23019 inhibited p38 MAPK and ERK1/2 signaling pathways activated by HDL (or S1P) and the downstream activation of CREB, a key transcription factor involved in Cox-2 transcriptional up-regulation. These results indicate that S1P receptors, in particular S1P2 and S1P3, are involved in the Cox-2-dependent effects of HDL on vascular cells. Strategies aimed to therapeutically modulate S1P or S1P receptors could be useful to improve cardiovascular protection.


1991 ◽  
Vol 260 (5) ◽  
pp. H1713-H1717 ◽  
Author(s):  
U. Ikeda ◽  
M. Ikeda ◽  
T. Oohara ◽  
A. Oguchi ◽  
T. Kamitani ◽  
...  

We have investigated the effect of interleukin 6 (IL-6) on the growth of vascular smooth muscle cells (VSMC) isolated from rat aortas. Murine recombinant IL-6 significantly increased the number of VSMC and stimulated tritiated thymidine incorporation into VSMC in a dose-dependent manner. The IL-6-induced thymidine incorporation into VSMC was totally inhibited by the Ca2+ channel blocker verapamil; however, IL-6 showed no effects on the intracellular Ca2+ level ([Ca2+]i) in VSMC. Antibody against platelet-derived growth factor (PDGF) also totally inhibited the IL-6-induced thymidine uptake. PDGF caused a significant increase in the [Ca2+]i, which was totally inhibited by verapamil. IL-6 mRNA was not detected in unstimulated “quiescent” VSMC, but its expression was stimulated by exposure of VSMC to 10% fetal bovine serum. Immunohistochemical study using anti-PDGF antibody showed that IL-6 stimulated PDGF production in VSMC. These results support the premise that IL-6 is released by VSMC in an autocrine manner and promotes the growth of VSMC via induction of endogenous PDGF production.


1985 ◽  
Vol 249 (3) ◽  
pp. E292-E298
Author(s):  
N. Kaiser ◽  
A. Tur-Sinai ◽  
M. Hasin ◽  
E. Cerasi

The interaction of insulin with the vascular smooth muscle was studied using cultures derived from the bovine aortic arch. The cultured cells exhibited specific binding of 125I-insulin that was reversible and dependent on pH. Both insulin and insulinlike growth factor (IGF) I competed for 125I-insulin binding; IGF I, however, was less effective than insulin by at least an order of magnitude. Insulin binding was accompanied by internalization and degradation of the hormone in a temperature- and time-dependent manner. Chloroquine and other lysosomotropic agents elevated the internalized insulin and reduced its degradation. Pre-exposure of cell cultures to insulin resulted in downregulation of cell surface receptors. Insulin stimulated alpha-aminoisobutyric acid transport in confluent smooth muscle cells. The maximal response was observed at 100 ng/ml insulin with a half-maximal effect at 10 ng/ml. Sparse, serum-starved smooth muscle cells responded to insulin with a dose-dependent increase in [3H]-thymidine incorporation into DNA. Although the effect was already apparent at 1 ng/ml insulin, it reached near maximal level only at 10,000 ng/ml. IGF I also stimulated DNA synthesis in smooth muscle cells; however, at low concentrations insulin was more efficient in this respect. Human growth hormone was inactive. The data indicate the presence of specific receptors for insulin in bovine aortic smooth muscle cells. These receptors appear to mediate the metabolic activity as well as part of the mitogenic effect of insulin in these cells.


2020 ◽  
Author(s):  
Yi Yan ◽  
Ting Li ◽  
Zhonghao Li ◽  
Mingyuan He ◽  
Dejiang Wang ◽  
...  

Abstract Background: Our previous work revealed that augmented AMPK activation inhibit cell migration by phosphorylating its substrate Pdlim5. As medial VSMCs contribute to the major composition of atherosclerotic plaques, a hypothesis is raised that modulation of AMPK-Pdlim5 signal pathway could retard the development of atherosclerosis through inhibiting migration of VSMCs. Therefore, we initiate the present study to investigate whether AMPK agonist like metformin is beneficial for suppressing diabetes-accelerated atherosclerosis in a diabetic mouse model induced by streptozotocin and high fat diet.Methods: For cell experiment, vascular smooth muscle cells (VSMCs) were overexpressed flag fused Pdlim5 and Pdlim5 mutant. Then the engineered VSMCs were introduced with metformin or control drug before determination of phosphorylated Pdlim5 with immunoblotting. For animal work, 8-week-old male ApoE−/−mice were induced diabetes with streptozotocin and then were randomly divided into 8 groups: control group, metformin hydrochloride (300 mg/kg/day) group, wildtype-Pdlim5 (Pdlim5 WT) carried adenovirus (Ad) group, Ad Pdlim5 WT and Met group, Ad Pdlim5 S177A group, Ad Pdlim5 S177A and Met group, Ad Pdlim5 S177D group, Ad Pdlim5 S177D and Met group. All mice were fed with high fat diet after virus infection. At the end, mice were sacrificed to observe atherosclerotic plaques and deposition of VSMCs in plaques. Moreover, 12–15-week-old Myh11-cre-EGFP male mice were accepted ligation of the left carotid artery and randomly divided into control and metformin treatment group. Finally, the injured vessel of Myh11-cre-EGFP mice were isolated to analyze the relationship between AMPK activation and neointima formation.Results: It was found that AMPK directly phosphorylate Pdlim5 at Ser177 in vitro, and metformin, an AMPK agonist, could induce phosphorylation of Pdlim5 indirectly and inhibition of cell migration as a result. Exogenous expression of phosphomimetic S177D-Pdlim5 inhibits lamellipodia formation and migration in VSMCs. It was also demonstrated that VSMCs contribute to the major composition of injury-induced neointimal lesions, while metformin could alleviate the occlusion of carotid artery in a wire-injury mice model. In order to investigate the function of AMPK-Pdlim5 pathway in the context of pathological condition, ApoE−/− male mice were divided randomly into control, streptozocin and high fat diet-induced diabetes mellitus, STZ + HFD together with metformin or Pdlim5 mutant carried adenovirus treatment groups. The results showed increased plasma lipids and aggravated vascular smooth muscle cells infiltration into the atherosclerotic lesion in diabetic mice compared with control mice. However, metformin alleviated diabetes-induced metabolic disorders and atherosclerosis, as well as decreased VSMCs infiltration in atherosclerotic plaques, while Pdlim5 phospho-abolished mutant carried adenovirus S177A-Pdlim5 undermine this protective function.Conclusions: The activation of AMPK-Pdlim5 pathway by chemicals like Metformin could inhibit formation of migratory machine of VSMCs and alleviate the progress of atherosclerotic plaques in diabetic mice. The maintenance of AMPK activity is beneficial for suppressing diabetes-accelerated atherosclerosis or metabolic syndrome.


Author(s):  
Jiefang Chen ◽  
Shulan Pi ◽  
Cheng Yu ◽  
Hanqing Shi ◽  
Yuxiao Liu ◽  
...  

Objective: Recent studies suggest that the P2Y12 (P2Y purinoceptor 12) receptor of vascular smooth muscle cells in atherosclerotic plaques aggravates atherosclerosis, and P2Y12 receptor inhibitors such as CDL (clopidogrel) may effectively treat atherosclerosis. It is imperative to identify an effective biomarker for reflecting the P2Y12 receptor expression on vascular smooth muscle cells in plaques. Approach and Results: We found that there was a positive correlation between the level of circulating sLRP1 (soluble low-density lipoprotein receptor-related protein 1) and the number of LRP1 + α-SMA + (α-smooth muscle actin), P2Y12 + , or P2Y12 + LRP1 + cells in plaques from apoE −/− mice fed a high-fat diet. Furthermore, activation of the P2Y12 receptor increased the expression and shedding of LRP1 in vascular smooth muscle cells by inhibiting cAMP (3'-5'-cyclic adenosine monophosphate)/PKA (protein kinase A)/SREBP-2 (sterol regulatory element binding transcription factor 2). Conversely, genetic knockdown or pharmacological inhibition of the P2Y12 receptor had the opposite effects. Additionally, CDL decreased the number of lesional LRP1 + α-SMA + cells and the levels of circulating sLRP1 by activating cAMP/PKA/SREBP-2 in apoE −/− mice fed a high-fat diet. Conclusions: Our study suggests that sLRP1 may be a biomarker that reflects the P2Y12 receptor level in plaques and has the potential to be an indicator for administering P2Y12 receptor inhibitors for patients with atherosclerosis.


1997 ◽  
Vol 273 (2) ◽  
pp. H628-H633 ◽  
Author(s):  
J. W. Gu ◽  
T. H. Adair

We determined whether hypoxia-induced expression of vascular endothelial growth factor (VEGF) can be reversed by a normoxic environment. Dog myocardial vascular smooth muscle cells (MVSMCs) were exposed to hypoxia (1% O2) for 24 h and then returned to normoxia (20% O2). VEGF protein levels increased by more than fivefold after 24 h of hypoxia and returned to baseline within 24 h of the return of the cells to normoxia. Northern blot analysis showed that hypoxia caused a 5.5-fold increase in VEGF mRNA, and, again, the expression was reversed after reinstitution of normoxia. Additional measurements showed that basic fibroblast growth factor and platelet-derived growth factor protein levels were not induced by hypoxia and that hypoxia caused a fourfold decrease in transforming growth factor-beta 1 protein levels. Hypoxia conditioned media from MVSMCs caused human umbilical vein endothelial cells to increase [3H]thymidine incorporation by twofold, an effect that was blocked in a dose-dependent manner by anti-human VEGF antibody. The hypoxia conditioned media had no effect on MVSMC proliferation. These findings suggest that VEGF expression can be bidirectionally controlled by tissue oxygenation, and thus support the hypothesis that VEGF is a physiological regulator of angiogenesis.


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