Recombinant Laminin Alpha 5 Lg1-3 Domains Support The Stemness Of Human Mesenchymal Stem Cells

The extracellular matrix components laminin and elastin serve key roles in stem cell therapy. Elastin-like polypeptides (ELPs), derived from a soluble form of elastin, affect the proliferation and differentiation of various types of cells. In the present study, a novel protein was designed containing globular domains 1-3 of laminin alpha 5 (L alpha 5LG1-3) fused to ELPs (L alpha 5LG1-3/ELP). L alpha 5LG1-3/ELP was expressed in Escherichia coli and displayed a molecular size of similar to 70 kDa on 12% SDS-polyacrylamide gels. The cellular activities, such as cellular adhesion (adhesion assay) and proliferation (MTT cytotoxicity assay), of human mesenchymal stem cells (hMSCs) treated with 1 mu g/ml of L alpha 5LG1-3/ELP were enhanced compared with those of untreated cells. Additionally, the number of undifferentiated hMSCs and their degree of stemness were assessed based on the gene expression levels of the stem cell markers cluster differentiation 90 (CD90), endoglin (CD105) and CD73. The expression levels of these markers were upregulated by 2.42-, 2.29- and 1.92-fold, respectively, in the hMSCs treated with L alpha 5LG1-3/ELP compared with the levels in untreated controls. Thus, L alpha 5LG1-3/ELP may be used to enhance the viability of hMSCs and preserve their undifferentiated state, whereby the clinical applications of hMSCs may be improved.