Antiproliferative effects of calcitonin gene-related peptide in aortic and pulmonary artery smooth muscle cells

2005 ◽  
Vol 288 (1) ◽  
pp. L202-L211 ◽  
Author(s):  
N. N. Chattergoon ◽  
F. M. D'Souza ◽  
W. Deng ◽  
H. Chen ◽  
A. L. Hyman ◽  
...  

Pulmonary hypertension is characterized by vascular remodeling involving smooth muscle cell proliferation and migration. Calcitonin gene-related peptide (CGRP) and nitric oxide (NO) are potent vasodilators, and the inhibition of aortic smooth muscle cell (ASMC) proliferation by NO has been documented, but less is known about the effects of CGRP. The mechanism by which overexpression of CGRP inhibits proliferation in pulmonary artery smooth muscle cells (PASMC) and ASMC following in vitro transfection by the gene coding for prepro-CGRP was investigated. Increased expression of p53 is known to stimulate p21, which inhibits G1 cyclin/cdk complexes, thereby inhibiting cell proliferation. We hypothesize that p53 and p21 are involved in the growth inhibitory effect of CGRP. In this study, CGRP was shown to inhibit ASMC and PASMC proliferation. In PASMC transfected with CGRP and exposed to a PKA inhibitor (PKAi), cell proliferation was restored. p53 and p21 expression increased in CGRP-treated cells but decreased in cells treated with CGRP and PKAi. PASMC treated with CGRP and a PKG inhibitor (PKGi) recovered from inhibition of proliferation induced by CGRP. ASMC treated with CGRP and then PKAi or PKGi recovered only when exposed to the PKAi and not PKGi. Although CGRP is thought to act through a cAMP-dependent pathway, cGMP involvement in the response to CGRP has been reported. It is concluded that p53 plays a role in CGRP-induced inhibition of cell proliferation and cAMP/PKA appears to mediate this effect in ASMC and PASMC, whereas cGMP appears to be involved in PASMC proliferation.

2017 ◽  
Vol 42 (6) ◽  
pp. 2569-2581 ◽  
Author(s):  
Zengxian Sun ◽  
Xiaowei Nie ◽  
Shuyang Sun ◽  
Shumin Dong ◽  
Chunluan Yuan ◽  
...  

Background/Aims: Increasing evidence has demonstrated a significant role of long non-coding RNAs (lncRNAs) in diverse biological processes, and many of which are likely to have functional roles in vascular remodeling. However, their functions in pulmonary arterial hypertension (PAH) remain largely unknown. Pulmonary vascular remodeling is an important pathological feature of PAH, leading to increased vascular resistance and reduced compliance. Pulmonary artery smooth muscle cells (PASMCs) dysfunction is involved in vascular remodeling. Long noncoding RNAs are potential regulators of PASMCs function. Herein, we determined whether long noncoding RNA–maternally expressed gene 3 (MEG3) was involved in PAH-related vascular remodeling. Methods: The arterial wall thickness was examined by hematoxylin and eosin (H&E) staining in distal pulmonary arteries (PAs) isolated from lungs of healthy volunteers and PAH patients. The expression level of MEG3 was analyzed by qPCR. The effects of MEG3 on human PASMCs were assessed by cell counting Kit-8 assay, BrdU incorporation assay, flow cytometry, scratch-wound assay, immunofluorescence, and western blotting in human PASMCs. Results: We revealed that the expression of MEG3 was significantly downregulated in lung and PAs of patients with PAH. MEG3 knockdown affected PASMCs proliferation and migration in vitro. Moreover, inhibition of MEG3 regulated the cell cycle progression and made more smooth muscle cells from the G0/G1 phase to the G2/M+S phase and the process could stimulate the expression of PCNA, Cyclin A and Cyclin E. In addition, we found that the p53 pathway was involved in MEG3–induced smooth muscle cell proliferation. Conclusions: This study identified MEG3 as a critical regulator in PAH and demonstrated the potential of gene therapy and drug development for treating PAH.


Cells ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 802 ◽  
Author(s):  
Lee ◽  
Kang

Regulation of vascular smooth muscle cell (VSMC) proliferation is essential to maintain vascular homeostasis. Hypoxia induces abnormal proliferation of VSMCs and causes vascular proliferative disorders, such as pulmonary hypertension and atherosclerosis. As several cyclin/cyclin-dependent kinase (CDK) complexes and CDK inhibitors (CKIs) control cell proliferation, in this study, we investigated CKIs involved in the hypoxia-induced proliferation process of human primary pulmonary artery smooth muscle cells to understand the underlying molecular mechanism. We demonstrated that p15, p16, and p21 are downregulated in pulmonary artery smooth muscle cells when exposed to hypoxia. In addition, we identified novel hypoxia-induced microRNAs (hypoxamiRs) including miR-497, miR-1268a, and miR-665 that are upregulated under hypoxia and post-transcriptionally regulate p15, p16, and p21 genes, respectively, by directly targeting their 3’UTRs. These miRNAs promoted the proliferation of VSMCs, and their inhibition decreased VSMC proliferation even in hypoxic conditions. Overall, this study revealed that miRNA-mediated regulatory mechanism of CKIs is essential for hypoxia-induced proliferation of VSMCs. These findings provide insights for a better understanding of the pathogenesis of vascular proliferative disorders.


1990 ◽  
Vol 63 (02) ◽  
pp. 291-297 ◽  
Author(s):  
Herm-Jan M Brinkman ◽  
Marijke F van Buul-Worteiboer ◽  
Jan A van Mourik

SummaryWe observed that the growth of human umbilical arterysmooth muscle cells was inhibited by the phospholipase A2 inhibitors p-bromophenacylbromide and mepacrine. Thesefindings suggest that fatty acid metabolism might be integrated in the control mechanism of vascular smooth muscle cell proliferation. To identify eicosanoids possibly involved in this process, we studied both the metabolism of arachidonic acid of these cells in more detail and the effect of certain arachidonic acid metabolites on smooth muscle cells growth. We found no evidence for the conversion of arachidonic acid via the lipoxygenase pathway. In contrast, arachidonic acid was rapidly converted via the cyclooxy-genase pathway. The following metabolites were identified: prostaglandin E2 (PGE2), 6-keto-prostaglandin F1α (6-k-PGF1α), prostaglandin F2α (PGF2α), 12-hydroxyheptadecatrienoic acid (12-HHT) and 11-hydroxyeicosatetetraenoic acid (11-HETE). PGE2 was the major metabolite detected. Arachidonic acid metabolites were only found in the culture medium, not in the cell. After synthesis, 11-HETE was cleared from the culture medium. We have previously reported that PGE2 inhibits the serum-induced [3H]-thymidine incorporation of growth-arrested human umbilical artery smooth muscle cells. Here we show that also 11-HETEexerts this inhibitory property. Thus, our data suggeststhat human umbilical artery smooth muscle cells convert arachidonic acid only via the cyclooxygenase pathway. Certain metabolites produced by this pathway, including PGE2 and 11-HETE, may inhibit vascular smooth muscle cell proliferation.


2003 ◽  
Vol 94 (4) ◽  
pp. 1403-1409 ◽  
Author(s):  
A. Cogo ◽  
G. Napolitano ◽  
M. C. Michoud ◽  
D. Ramos Barbon ◽  
M. Ward ◽  
...  

Although it is well known that hypoxemia induces pulmonary vasoconstriction and vascular remodeling, due to the proliferation of both vascular smooth muscle cells and fibroblasts, the effects of hypoxemia on airway smooth muscle cells are not well characterized. The present study was designed to assess the in vitro effects of hypoxia (1 or 3% O2) on rat airway smooth muscle cell growth and response to mitogens (PDGF and 5-HT). Cell growth was assessed by cell counting and cell cycle analysis. Compared with normoxia (21% O2), there was a 42.2% increase in the rate of proliferation of cells exposed to 3% O2 (72 h, P = 0.006), as well as an enhanced response to PDGF (13.9% increase; P = 0.023) and to 5-HT (17.2% increase; P = 0.039). Exposure to 1% O2 (72 h) decreased cell proliferation by 21.0% ( P = 0.017) and reduced the increase in cell proliferation induced by PGDF and 5-HT by 16.2 and 15.7%, respectively ( P = 0.019 and P = 0.011). A significant inhibition in hypoxia-induced cell proliferation was observed after the administration of bisindolylmaleimide GF-109203X (a specific PKC inhibitor) or downregulation of PKC with PMA. Pretreatment with GF-109203X decreased proliferation by 21.5% ( P = 0.004) and PMA by 31.5% ( P = 0.005). These results show that hypoxia induces airway smooth muscle cell proliferation, which is at least partially dependent on PKC activation. They suggest that hypoxia could contribute to airway remodeling in patients suffering from chronic, severe respiratory diseases.


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