In this work, rat BMSCs were infected by recombinant lentiviruses to construct tropomyosin receptor kinase A (TrkA)-overexpressing BMSCs and TrkA-shRNA-expressing BMSCs, which were then used in transplantation for rat sciatic nerve defects.
We showed that lentivirus-mediated overexpression of TrkA in BMSCs can promote cell survival and protect against serum-starve-induced apoptosis in vitro. At 8 weeks after transplantation, the Schwann-like differentiated ratio of the existing implanted cells had reached 74.8 ± 1.6% in TrkA-overexpressing BMSCs-laden nerve grafts, while 40.7 ± 2.3% and 42.3 ± 1.5% in vector and control BMSCs-laden nerve grafts, but only 8.2 ± 1.8% in TrkA-shRNA-expressing BMSCs-laden nerve grafts. The cell apoptosis ratio of the existing implanted cells in TrkA-overexpressing BMSCs-laden nerve grafts was 16.5 ± 1.2%, while 33.9 ± 1.9% and 42.6 ± 2.9% in vector and control BMSCs-laden nerve grafts, but 87.2 ± 2.5% in TrkA-shRNA-expressing BMSCs-laden nerve grafts.
These results demonstrate that TrkA overexpression can improve the survival and Schwann-like cell differentiation of BMSCs and prevent cell death in nerve grafts, which may have potential implication in advancing cell transplantation for peripheral nerve repair.