Abstract
Background: To date, many attempts are employed to increase the regenerative potential of stem cells. In this study, we evaluated the hypothesis of whether an autophagy modulation could alter differentiation potency of CD146+ cells into mature pericyte, endothelial, and cardiomyocyte lineage. Methods: In this study, CD146+cells were enriched from the human bone marrow aspirates and trans-differentiated into mature endothelial cells, pericytes, and cardiomyocytes after exposure to autophagy stimulator (50-μM Met)/inhibitor (15-μM HCQ). The protein levels of autophagy proteins were monitored by western blotting. NO content was measured using the Griess assay. Using real-time PCR assay and western blotting, we monitored the lineage protein and gene levels. Pro-inflammatory cytokine and angiocrine factors were measured by ELISA. The fatty acid change was determined by gas chromatography. We also measured exosome secretion capacity by measuring AChE activity and real-time PCR assay. Result: Data revealed the modulation of autophagy factors, Beclin-1, P62, and LC3 II/I ratio in differentiating CD146+ cells after exposure to Met and HCQ (p < 0.05). The inhibition of autophagy increased NO content compared to the Met-treated cells (p < 0.05). Real-time PCR analysis showed that the treatment of CD146+ cells with autophagy modulators altered the expression of VE-cadherin, cTnI, and α-SMA (p < 0.05). Met increased the expression of VE-cadherin, α-SMA, and cTnI compared to the HCQ-treated cells (p < 0.05) while western blotting revealed the protein synthesis of all lineage-specific proteins under the stimulation and inhibition of autophagy. None statistically significant differences were found in the levels of Tie-1, Tie-2, VEGFR-1, and VEGFR-2 after autophagy modulation. Fatty acid profile analysis revealed the increase of unsaturated fatty acids after exposure to HCQ (p < 0.05). The treatment of cells with HCQ increased the levels of TNF-α and IL-6 compared to the Met-treated cells. Data revealed the increase of exosome biogenesis and secretion to the supernatant in cells treated with HCQ compared to the Met groups (p < 0.05). Conclusions: In summary, autophagy modulation could alter differentiation potency of CD146+cells which is important in cardiac regeneration.