The stimulatory effects of eNOS/F92A-Cav1 on NO production and angiogenesis in BMSCs

Nitric oxide (NO) is generated in endothelial cells by endothelial nitric oxide synthase (eNOS). Caveolin-1 (Cav1) inhibits eNOS function and NO production. Modifying Cav1 scaffold domain, in particular Phenylalanine at position 92 (F92) is critical for the inhibitory actions of Cav1 toward eNOS. The aims of this study were to investigate the effect of enhanced NO production in term of in vitro angiogenesis on rat bone marrow derived mesenchymal stem cells (BMSCs) transduced with a novel bicistronic lentiviral vector co-expressing eNOS and mutant Cav1 (F92A). METHODS: A bicistronic eNOS/F92-Cav1 lentiviral vector was constructed, and used to transduce rat BMSCs. The expression of eNOS and VEGF protein were confirmed by western-blot. NO production was detected by the greiss assay and in vitro angiogenesis was assessed by matrigel assisted capillary tube formation. The cell viability was evaluated using a Cell Counting Kit (CCK)-8. RESULTS: The bicistronic eNOS/F92A-Cav1 lentiviral vector increased eNOS and VEGF protein expression, NO production compared to controls. In vitro capillary formation was increased in eNOS-F92A transduced cells and cell viability was not affected by transduction. CONCLUSION: Transduction of rat BMSCs with an eNOS-F92A-Cav1 lentiviral vector can increase NO production by enhancing eNOS protein expression. The increased NO production did not reduce cell viability. This study demonstrates that genetic modification of BMSCs to enhance NO producton could be applied in stem cell based therapeutic approaches to treat diseases such as pulmonary arterial hypertension (PAH) which is characterized by decreased endothelial NO release.