ABSTRACT
Arterial calcification (AC) is mainly caused by osteoblast phenotypic transition of vascular smooth muscle cells (VSMCs). Long noncoding RNA H19 (lncRNA H19) has attracted increasingly attention because of their transcriptional regulation crucial potency. We reported that lncRNA H19 expression is up-regulated after VSMCs transition. Thus, we aim to study the role of H19 and the molecular mechanisms in VSMCs transition. To determine the expression of H19 in calcified VSMCs, we induced VSMCs calcification with 10 mM ß-glycerophosphate. By qPCR and Western Blot analysis, we found that the expression of lncRNA H19, Runx2 and OSX were all highly increased in calcified VSMCs compared with normal VSMCs, while the expression of VSMCs differentiation markers, SM22-α and α-SMA, were significantly decreased. SiRNA study showed that knockdown of lncRNA H19 can decrease VSMCs calcification and Runx2 expression. We further validated that lncRNA H19 promoted VSMCs calcification via the p38 MAPK and ERK1/2 signal transduction pathways. As a conclusion, the present study showed that lncRNA H19/Runx2 axis promotes VSMCs transition via MAPK pathway. This finding not only reveal a novel function of lncRNA H19, but also provides a new opinion on the role of lncRNA H19 which participant in the Runx2 regulatory pathway in AC and can be a new indication for the diagnosis and treatment of AC at an early time.
ABSTRACT
Cardiovascular progenitor cells (CPCs) expressing the ISL1-LIM-homeodomain transcription factor contribute developmentally to cardiomyocytes in all 4 chambers of the heart. Here, we show that ISL1-CPCs can be applied to myocardial regeneration following injury. We used a rapid 3D methylcellulose approach to form murine and human ISL1-CPC spheroids that engrafted after myocardial infarction in murine hearts, where they differentiated into cardiomyocytes and endothelial cells, integrating into the myocardium and forming new blood vessels. ISL1-CPC spheroid-treated mice exhibited reduced infarct area and increased blood vessel formation compared with control animals. Moreover, left ventricular (LV) contractile function was significantly better in mice transplanted with ISL1-CPCs 4 weeks after injury than that in control animals. These results provide proof-of-concept of a cardiac repair strategy employing ISL1-CPCs that, based on our previous lineage-tracing studies, are committed to forming heart tissue, in combination with a robust methylcellulose spheroid-based delivery approach.
