范雪松
中国医学科学院阜外医院 检验科
The increase of reactive oxygen species in infracted heart significantly reduces the survival of donor mesenchymal stem cells, thereby attenuating the therapeutic efficacy for myocardial infarction. In our previous study, we demonstrated that lysophosphatidic acid (LPA) protects bone marrow-derived mesenchymal stem cells (BMSCs) against hypoxia and serum deprivation-induced apoptosis. However, whether LPA protects BMSCs from H2O2-induced apoptosis was not examined. In this study, we report that H2O2 induces rat BMSC apoptosis whereas LPA pre-treatment effectively protects BMSCs from H2O2-induced apoptosis. LPA protection of BMSC from the induced apoptosis is mediated mostly through LPA3 receptor. Furthermore, we found that membrane G protein Gi2 and Gi3 are involved in LPA-elicited anti-apoptotic effects through activation of ERK1/2- and PI3 K-pathways. Additionally, H2O2 increases levels of type II of light chain 3B (LC3B II), an autophagy marker, and H2O2-induced autophagy thus protected BMSCs from apoptosis. LPA further increases the expression of LC3B II in the presence of H2O2. In contrast, autophagy flux inhibitor bafilomycin A1 has no effect on LPA's protection of BMSC from H2O2-induced apoptosis. Taken together, our data suggest that LPA rescues H2O2-induced apoptosis mainly by interacting with Gi-coupled LPA3, resulting activation of the ERK1/2- and PI3 K/AKT-pathways and inhibition caspase-3 cleavage, and LPA protection of BMSCs against the apoptosis is independent of it induced autophagy.
Apoptosis : an international journal on programmed cell death 2015
BACKGROUND:Coronary atherosclerotic unstable plaque is one of the leading causes of cardiovascular death. Macrophage-derived matrix metalloproteinase (MMP) 9 is considered for degrading extracellular matrix and collagen, thereby thinning the fibrous cap in plaques. miR-21 is implicated to play an important role in the progression of atherosclerosis. Nevertheless, miR-21 as the biomarker for coronary atherosclerotic unstable plaque remains unknown. We aimed to investigate the prediction role of miR-21 for unstable plaque by pathway study of miR-21 on MMPs and its inhibitor RECK in macrophages.METHODS:Expression of miR-21 in macrophages and serum miR-21 as well as MMP-9 was measured in patients with coronary non-calcified plaque, calcified plaque and controls. In vitro experiment was done in human macrophages by over-expressing miR-21 or down-regulating RECK. The regulation of RECK and MMP-9 by miR-21 was evaluated by western blotting and siRNA strategy.RESULTS:Patients with non-calcified coronary artery lesions had significantly higher miR-21 in macrophages and lower miR-21 serum levels compared to the control and calcified plaque patients. At the same time, the serum levels of MMP-9 were significantly elevated in non-calcified patients. Experiments in vitro indicated that over-expressing miR-21 could induce the expression and secretion of pro-MMP-9 and active-MMP-9 in human macrophages via targeting gene RECK, and knocking down RECK expression by specific siRNA can resemble that of miR-21 over-expression.CONCLUSIONS:miR-21 might be a biomarker for plaque instability by suppressing target gene RECK to promote the expression and secretion of MMP-9 in macrophages.
Experimental and molecular pathology 2014
