miR-599 Inhibits Vascular Smooth Muscle Cells Proliferation and Migration by Targeting TGFB2
November
miR-599 Inhibits Vascular Smooth Muscle Cells Proliferation and Migration by Targeting TGFB2
Baodong Xie 0 1
Chunfeng Zhang 0 1
Kai Kang 0 1
Shulin Jiang 0 1
0 Department of Cardiovascular Surgery, the Second Affiliated Hospital of Harbin Medical University , Harbin, Heilongjiang , China
1 Editor: Zheng Li, Peking Union Medical College Hospital , CHINA
Aberrant proliferation and migration of vascular smooth muscle cells (VSMCs) play a crucial role in the pathogenesis of cardiovascular diseases including coronary heart disease, restenosis and atherosclerosis. MicroRNAs are a class of small, non-coding and endogenous RNAs that play critical roles in VSMCs function. In this study, we showed that PDGF-bb, as a stimulant, promoted VSMCs proliferation and suppressed the expression of miR-599. Moreover, overexpression of miR-599 inhibited VSMCs proliferation and also suppressed the PCNA and ki-67 expression. In addition, we demonstrated that ectopic expression of miR-599 repressed the VSMCs migration. We also showed that miR-599 inhibited type I collagen, type V collagen and proteoglycan expression. Furthermore, we identified TGFb2 as a direct target gene of miR-599 in VSMCs. Overexpression of TGFb2 reversed miR-599induced inhibition of VSMCs proliferation and type I collagen, type V collagen and proteoglycan expression. In conclusion, our findings suggest miR-599 plays a crucial role in controlling VSMCs proliferation and matrix gene expression by regulating TGFb2 expression.
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Cardiovascular diseases are a major cause of death worldwide and they include atherosclerosis,
coronary artery disease (CAD), stroke, congestive heart failure, hypertension, myocardial
infarction (MI)[1–4]. It is accepted that abnormal proliferation of vascular smooth muscle cells
(VSMCs) is a critical event in the development of cardiovascular diseases [5–7]. However, their
detail molecular mechanisms have not been fully illuminated.
MicroRNAs (miRNAs) are a class of small (18–24 nucleotides) non-coding and endogenous
RNAs that modulate gene expression through binding to 3’UTR (3’ untranslated regions) of
target mRNAs to lead to protein translational repression [8–12]. A lot of studies have
demonstrated that miRNAs are involved in various cellular processes including cell development,
growth, survival, differentiation, proliferation and apoptosis [13–16]. Increasing evidences also
find that deregulated expression of miRNA is implicated in many cancers such as gastric
no role in study design, data collection and analysis,
decision to publish, or preparation of the manuscript.
Competing Interests: The authors have declared
that no competing interests exist.
cancer, osteosarcoma, hepatocellular carcinoma, lung cancer and colorectal cancer [17–22].
Recently, many evidences have also proved that miRNAs play critical role in the VSMCs
function [23]. For example, Torella et al. demonstrated that miR-133 played important roles in
VSMCs phenotypic switch in vivo and in vitro [24]. Wang et al. showed that miR-31
expression was increased in quiescent differentiated VSMCs and decreased in proliferative cells
treated by serum starvation and platelet-derived growth factor [25]. Li et al. reported that
miR638 was a key molecule in regulating human VSMC proliferation and migration by targeting
the NOR1/cyclin D pathway [26]. However, functions of miRNAs in VSMC are still less
explored.
Otaegui et al. showed that miR-599 in peripheral blood mononuclear cell may be relevant at
the time of relapse in multiple sclerosis patients [27]. Wojcicka et al [28]. showed that four
microRNAs (miR-425,miR-155, miR-599 and miR-592) potentially targeted THRB transcript.
However, the role of miR-599 in VSMCs was still unknown. In this study, we showed that
PDGF-bb, as a stimulant, promoted VSMCs proliferation and suppressed the expression of
miR-599. Moreover, overexpression of miR-599 inhibited VSMCs proliferation and also
suppressed the PCNA and ki-67 expression. In addition, we demonstrated that ectopic expression
of miR-599 repressed the VSMCs migration. We also showed that miR-599 inhibited type I
collagen, type V collagen and proteoglycan expression. Furthermore, we identified TGFb2 as a
direct target gene of miR-599 in VSMCs. Overexpression of TGFb2 reversed miR-599 induced
inhibition of VSMCs proliferation and type I collagen, type V collagen and proteoglycan
expression.
Materials and Methods
Ethics Statement
The protocol for our study was approved by the Ethical Committee of the Second Affiliated
Hospital of Harbin Medical University.
Cells Culture and Oligonucleotide Transfection
The VSMCs cell line was purchased from Cascade Biologics (Portland, OR) and kept in
DMEM/F12 medium(Dulbecco’s modified Eagle’s medium; Invitrogen, Carlsbad, CA).
miR599 and scramble oligonucleotide was purchased from GenePharma (Shanghai, China) and
transfected into the VSMCs used Lipofectamine 2000 (Invitrogen, Carlsbad, CA) according to
the manufacturer’s informatio (...truncated)