In vitro effects of Wnt3a gene modification on mitigating damage of mouse bone marrow mesenchymal stem cells induced by Ara-C / 中国实验血液学杂志

This study was aimed to investigate the protective effect of Wit3a gene modification on mouse bone marrow mesenchymal stem cells against the injury induced by Ara-C. The gene-modified MSC steadily expressing Wnt3a were established by adenovirus system. The acute direct damage effects of different concentrations of Ara-C on the unmodified MSC and the gene-modified MSC were assessed by using an in vitro culture system, and the corresponding controls were set. The proliferation and apoptosis of MSC exposed to Ara-C were detected by cell count kit-8 (CCK-8) and flow cytometry. The expression of BCL-2 protein related with cell apoptosis was assayed by Western blot. The results indicated that as compared with unmodified MSC, Ara-C exhibited a less inhibitory effect on the proliferation of gene-modified MSC. There was obvious difference between unmodified MSC and gene-modified MSC (p < 0.05). The proliferation of gene-modified MSC began to recover at 72 hours after removal of Ara-C. However, unmodified MSC showed sustained suppression of proliferation after withdrawal of Ara-C. In apoptosis, the apoptosis rate of gene-modified MSC induced by Ara-C was significantly lower than those of unmodified MSC (p < 0.05). In addition, the expression levels of BCL-2 protein in gene-modified MSC were up-regulated compared with unmodified MSC (p < 0.05). It is concluded that Wnt3a gene modification can significantly mitigate the damage of mouse bone marrow MSC induced by Ara-C.

Effect of Wnt3a-transduced bone marrow mesenchymal stem cells on the proliferation of T lymphocytes / 中华血液学杂志

<p><b>OBJECTIVE</b>To observe the effect of Wnt3a-transduced mouse bone marrow mesenchymal stem cells (MSC) on the proliferation of T lymphocytes.</p><p><b>METHODS</b>MSC were isolated from C57BL/6 mouse bone marrow and expanded in vitro, then identified by flow cytometry and their differentiation capacity into osteocytes and adipocytes were determined. Recombinant plasmids containing Wnt3a gene, were transfected with lipofectamine into HEK293 cells by the AdEasy system. Viral particles were collected to infect MSC and adenovirus vector expressing GFP (Ad-GFP) was used as control. The expression of GFP in MSC was observed using fluorescence microscopy and the protein levels of Wnt3a and β-catenin were determined by Western blot. Wnt3a-transduced and Ad-GFP transduced MSC were separately cocultured with spleen lymphocytes stimulated by ConA, at the ratio of 1:100, 1:50 or 1:10 respectively. The proliferation rate of T lymphocytes was estimated by Cell Cout Kit-8 (CCK-8) and the level of cytokine by ELISA.</p><p><b>RESULTS</b>FCM analysis showed that the MSC were highly positive for CD90.2, CD44 and negative for CD34, CD45, they could differentiate into osteoblasts and adipocytes after induction; The titer of recombinant adenoviruses was up to 1 × 10(10) pfu/ml. After infected with the adenoviruses, MSC had the strongest GFP expression at 72 h and the efficiency of infection was 50%-60%. The expressions of Wnt3a and β-catenin protein in the Wnt3a-transduced MSC were significantly increased. MSC could suppress the proliferation of T lymphocytes in a dose-dependent manner. When MSC cocultured with spleen lymphocytes at 1:10 ratio, T lymphocyte proliferation rate and the level of IFN-γ were (55.41 ± 1.75)% and (326.70 ± 14.41) pg/ml respectively in Ad-GFP transduced MSC group, while in Wnt3a-transduced MSC group, they were (37.27 ± 2.66)% and (218.80 ± 12.93) pg/ml respectively. There was no effect on the production of IL-2.</p><p><b>CONCLUSION</b>Compared to Ad-GFP transduced MSC, Wnt3a-transduced MSC exhibit a more potent inhibitory effect on the proliferation of T lymphocytes.</p>