Autophagy modulation altered differentiation capacity of CD146+ cells toward endothelial cells, pericytes, and cardiomyocytes

Abstract

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.

Keywords

• Human bone marrow CD146+ cells
• Autophagy modulation
• Nitrosative assay
• Lineage-specific differentiation
• Exosome activity