■研究骨髓衍生生长因子(Mydgf)的丢失对心肌梗死(MI)后心脏成纤维细胞转化为肌成纤维细胞的影响。
■两个成鼠组,包括野生型(WT)组和另一组Mydgf敲除(Mydgf-KO),在研究中进行了检查。通过测量左心室射血分数(LVEF)和左心室缩短分数(LVFS)来测试这两组中的小鼠的心脏功能(n=10)。进行定量实时PCR(qRT-PCR)(n=3)以确定肌成纤维细胞标志物的mRNA表达水平,包括α-平滑肌肌动蛋白(α-SMA),骨膜素(postn),VIII型胶原(col8al),和结缔组织生长因子(ctgf)。进行蛋白质印迹(n=3)以验证α-SMA的蛋白表达水平。在WT和Mydgf-KO小鼠上进行MI建模。然后测量术后LVEF和LVFS(n=10)。收获心脏并进行Masson染色以确定梗死面积(n=10)。在MI后第7天和第14天收集Mydgf-KO和WT小鼠的心脏样本,分别,验证肌成纤维细胞标志物的表达(n=3)。
■与WT小鼠相比,成年Mydgf-KO小鼠LVEF和LVFS均无明显变化(均P>0.05)。然而,α-SMA和postn的mRNA水平上调,α-SMA蛋白表达也增加(均P<0.05)。MI之后,与WT小鼠相比,Mydgf-KO小鼠的LVEF和LVFS降低,梗死面积明显增加(P均<0.05)。此外,α-SMA的mRNA水平,col8al,postn,在Mydgf-KO小鼠中ctgf增加。此外,α-SMA蛋白表达上调,α-SMA阳性成纤维细胞增多(P<0.05)。
■Mydgf缺失促进心肌成纤维细胞向肌成纤维细胞转化,加重MI后心肌纤维化。
UNASSIGNED: To investigate the effect of the loss of myeloid-derived growth factor (Mydgf) on the transformation of cardiac fibroblasts into myofibroblasts after myocardial infarction (MI).
UNASSIGNED: Two adult mouse groups, including a wild-type (WT) group and another group with Mydgf knockout (Mydgf-KO), were examined in the study. The mice in these two groups were tested for their cardiac function by measuring left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) (n=10). Quantitative real-time PCR (qRT-PCR) (n=3) was performed to determine the mRNA expression levels of myofibroblast markers, including α-smooth muscle actin (α-SMA), periostin (postn), type Ⅷ collagen (col8al), and connective tissue growth factor (ctgf). Western blot (n=3) was performed to verify the protein expression levels of α-SMA. MI modeling was performed on the WT and the Mydgf-KO mice. Postoperative LVEF and LVFS (n=10) were then measured. The hearts were harvested and Masson staining was performed to determine the infarcted area (n=10). The heart samples of Mydgf-KO and WT mice were collected at d 7 and d 14 after MI, respectively, to verify the expression of myofibroblast markers (n=3).
UNASSIGNED: Compared with WT mice, LVEF and LVFS in adult Mydgf-KO mice showed no significant changes (all P>0.05). However, the mRNA levels of α-SMA and postn were upregulated, and α-SMA protein expression was also increased (all P<0.05). After MI, compared with WT mice, LVEF and LVFS in Mydgf-KO mice decreased, and the infarcted area increased significantly (all P<0.05). Furthermore, mRNA levels of α-SMA, col8al, postn, and ctgf were increased in Mydgf-KO mice. In addition, the α-SMA protein expression level was upregulated and α-SMA-positive fibroblasts were increased (P<0.05).
UNASSIGNED: Mydgf deletion promotes the transformation of cardiac fibroblasts into myofibroblasts and aggravates myocardial fibrosis after MI.