Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, 300 Technology Drive, Pittsburgh, PA 15219, USA.
Biochem Biophys Res Commun. 2010 Mar 19;393(4):582-6. doi: 10.1016/j.bbrc.2010.02.018. Epub 2010 Feb 10.
Stromal cells from fat tissues exhibit properties of mesenchymal stem cells from other sources with the ability to differentiate towards multiple cell types. However, effective differentiation of these mesenchymal cells, called adipose-derived stem cells (ADSCs), towards cardiomyogenic lineage has been limited to a small number of isolated clones in an extended culture. Previously, we reported that treatment with phorbol ester induces the expression of several cardiomyogenic genes in the absence of serum. This study was performed to identify the roles of PKC isoforms in cardiomyogenic gene expression of ADSCs. Treatment with 10nM phorbol myristate acetate (PMA) for 24h caused sustained increases in mRNA levels for various cardiomyogenic genes, such as Mef2C, cardiac actin and troponin, for at least 6 days following the drug removal. The use of various inhibitors specific for PKC isoforms demonstrated that the novel PKC-theta/delta isoforms mediate the PMA effects. RT-PCR revealed that ADSCs express significant mRNA for PKC-delta, but not theta isoform. Overexpression of cDNA for PKC-delta resulted in marked increases in cardiac mRNA expression. These results indicate that activation of PKC-delta induces the expression of multiple cardiomyogenic genes in ADSCs.
脂肪组织中的基质细胞表现出与其他来源的间充质干细胞相似的特性，具有向多种细胞类型分化的能力。然而，这些间充质细胞（称为脂肪来源的干细胞，ADSCs）向心肌细胞谱系的有效分化仅局限于少数在延长培养中分离的克隆。先前，我们报道了在无血清的情况下，佛波酯处理会诱导多种心肌生成基因的表达。本研究旨在确定 PKC 同工型在 ADSC 心肌生成基因表达中的作用。用 10nM 佛波酯 12-十四酰基佛波醇-13-醋酸盐（PMA）处理 24 小时会导致各种心肌生成基因，如 Mef2C、心肌肌动蛋白和肌钙蛋白的 mRNA 水平持续增加，在药物去除后至少 6 天内均保持这种状态。使用针对 PKC 同工型的各种特异性抑制剂表明，新型 PKC-θ/delta 同工型介导了 PMA 的作用。RT-PCR 显示 ADSC 表达大量 PKC-δ mRNA，但不表达 θ 同工型。PKC-δ cDNA 的过表达导致心脏 mRNA 表达的显著增加。这些结果表明，PKC-δ 的激活诱导 ADSC 中多种心肌生成基因的表达。
