Proprotein convertases 1 and 2 (PC1 and PC2) are expressed in neurally differentiated rat bone marrow stromal stem cells (BMSCs).

Neural-like cells derived from bone marrow stromal stem cells (BMSCs) have potential usefulness in cell therapy of degenerative or traumatic diseases of the central nervous system (CNS). The functional recovery mediated by these cells, however, depends on the secretion of neurotrophins (NTs) and their cognate receptors, as the main regulators of neural survival and death. The function of NTs is further modulated by proprotein convertase (PC) enzymes which function in converting proproteins (including proNTs) into their functional end products. Accordingly, failure in converting proprotein forms of NTs into their mature forms may lead to neuronal cell death. In the present study, we have investigated the expression profile of PCs before and during neural differentiation of rat BMSCs by RT-PCR. Our results show that major members of the PC family functioning in the constitutive secretory pathway (furin, PACE4 and PC7/LPC) are highly expressed in both undifferentiated and neurally differentiated BMSCs. In contrast, while PC1/PC3 and PC2 (specific to neural and endocrine cells) are absent in undifferentiated BMSCs, their expression is initiated upon the induction of differentiation. In conclusion, our results suggest that neurally differentiated BMSCs have acquired the functional machinery to process the precursor forms of proteins in both the constitutive and regulated pathways.