Vanella Luca, Raciti Giuseppina, Barbagallo Ignazio, Bonfanti Roberta, Abraham Nader, Campisi Agata
Department of Drug Sciences, Section of Biochemistry, University of Catania, Viale A. Doria 6, 95125, Catania, Italy.
CNS Neurol Disord Drug Targets. 2015;14(1):24-32. doi: 10.2174/1871527314666150116111339.
Herein, we assessed the expression of transglutaminase-2 (TG2) during in vitro neural differentiation of human Mesenchymal Stem Cells (hMSCs) induced by some Growth Factors (GFs). The amount and distribution of mRNAs for some transglutaminase (TGs) isoforms (TG1, TG2, TG3, TG5) were also evaluated. In addition, we tested some neural lineage markers (Glial Acid Fibrillary Protein, GFAP; Neurofilament Protein, NF; Nestin; β-Tubulin III). A progressive increase of all neural markers during GFs neural differentiation of hMSCs was found. A significant overexpression of TG1 and TG2 mRNA was observed in undifferentiated hMSCs. GFs-treatment induced a progressive decrease of TG1 mRNA during hMSCs differentiation. A significant down-regulation of TG2 mRNA in 2 days in vitro (DIV) GFs-treated cells was observed. TG2 mRNA progressively increased during GFs hMSCs differentiation, reaching after 6 DIV of GFs-treatment of similar values to those observed in undifferentiated cells. TG3 mRNA levels were express at very low only in undifferentiated hMSCs, whereas TG5 mRNA was undetectable in undifferentiated and differentiated hMSCs. Immunocytochemical and Western blot analysis showed an overexpression of TG2 in undifferentiated hMSCs. A dramatic reduction of the protein levels in 2 DIV GFs-treated cells was observed. Its expression levels progressively increased during the differentiation of hMSCs with GFs, reaching after 6 DIV of the treatment similar values to those observed in undifferentiated cells. Our findings demonstrate the presence of multiple TGs in hMSCs during neural differentiation in vitro induced by GFs, and suggest that TG2 may be part of the downstream events associated to neural differentiation.
在此，我们评估了在某些生长因子（GFs）诱导的人骨髓间充质干细胞（hMSCs）体外神经分化过程中转谷氨酰胺酶-2（TG2）的表达。还评估了一些转谷氨酰胺酶（TGs）同工型（TG1、TG2、TG3、TG5）的mRNA数量和分布。此外，我们检测了一些神经谱系标志物（胶质纤维酸性蛋白，GFAP；神经丝蛋白，NF；巢蛋白；β-微管蛋白III）。发现在hMSCs的GFs神经分化过程中所有神经标志物都有逐渐增加。在未分化的hMSCs中观察到TG1和TG2 mRNA的显著过表达。GFs处理在hMSCs分化过程中导致TG1 mRNA逐渐减少。在体外培养2天（DIV）的GFs处理细胞中观察到TG2 mRNA的显著下调。在GFs处理的hMSCs分化过程中TG2 mRNA逐渐增加，在GFs处理6 DIV后达到与未分化细胞中观察到的值相似的水平。TG3 mRNA水平仅在未分化的hMSCs中极低表达，而在未分化和分化的hMSCs中均未检测到TG5 mRNA。免疫细胞化学和蛋白质印迹分析显示未分化的hMSCs中TG2过表达。在2 DIV的GFs处理细胞中观察到蛋白质水平急剧降低。在hMSCs与GFs分化过程中其表达水平逐渐增加，在处理6 DIV后达到与未分化细胞中观察到的值相似的水平。我们的研究结果表明在GFs诱导的体外神经分化过程中hMSCs存在多种TGs，并提示TG2可能是与神经分化相关的下游事件的一部分。
