RESUMO
Amniotic fluid mesenchymal stromal cells (AF-MSCs) represent an autologous cell source to ameliorate congenital heart defects (CHDs) in children. The AF-MSCs, having cardiomyogenic potential and being of fetal origin, may reflect the physiological and pathological changes in the fetal heart during embryogenesis. Hence, the study of defects in the functional properties of these stem cells during fetal heart development will help obtain a better understanding of the cause of neonatal CHDs. Therefore, in the present study, we compared the proliferative and cardiomyogenic potential of AF-MSCs derived from ICHD fetuses (ICHD AF-MSCs) with AF-MSCs from structurally normal fetuses (normal AF-MSCs). Compared to normal AF-MSCs, the ICHD AF-MSCs showed comparable immunophenotypic MSC marker expression and adipogenic and chondrogenic differentiation potential, with decreased proliferation, higher senescence, increased expression of DNA-damaged genes, and osteogenic differentiation potential. Furthermore, the expression of cardiac progenitor markers (PDGFR-α, VEGFR-2, and SSEA-1), cardiac transcription factors (GATA-4, NKx 2-5, ISL-1, TBX-5, TBX-18, and MeF-2C), and cardiovascular markers (cTNT, CD31, and α-SMA) were significantly reduced in ICHD AF-MSCs. Overall, these results suggest that the AF-MSCs of ICHD fetuses have proliferation defects with significantly decreased cardiomyogenic differentiation potential. Thus, these defects in ICHD AF-MSCs highlight that the impaired heart development in ICHD fetuses may be due to defects in the stem cells associated with heart development during embryogenesis.
RESUMO
Aim: To explore the neuroprotective potential of the secretome (conditioned medium, CM) derived from neurotrophic factors-primed mesenchymal stromal cells (MSCs; primed CM) using an endoplasmic reticulum (ER) stress-induced in vitro model system. Methods: Establishment of ER-stressed in vitro model, immunofluorescence microscopy, real-time PCR, western blot. Results: Exposure of ER-stressed Neuro-2a cells to the primed-CM significantly restored the neurite outgrowth parameters and improved the expression of neuronal markers like Tubb3 and Map2a in them compared with the naive CM. Primed CM also suppressed the induction of apoptotic markers Bax and Sirt1, inflammatory markers Cox2 and NF-κB, and stress kinases such as p38 and SAPK/JNK in the stress-induced cells. Conclusion: The secretome from primed MSCs significantly restored ER stress-induced loss of neuro-regenesis.
Endoplasmic reticulum (ER) stress-mediated accumulation of misfolded protein is one of the causes involved in the onset of several neurodegenerative diseases (ND). Under physiological conditions, ER stress activates the unfolded protein response (UPR) that repairs the misfolded proteins. However, if the ER stress becomes chronic, the UPR fails to repair the misfolded proteins leading to disease conditions such as Parkinson's disease, Alzheimer's disease, multiple sclerosis, etc. Most in vitro systems are based on the infliction of acute ER stress on the target cells, which kills them, and thus, are not physiologically relevant models, as their neuro-regeneration is not possible. Here, we have developed a physiologically relevant in vitro model system, wherein we exposed Neuro-2a cells to an ER stress inducer which significantly affected their neuro-regenesis without killing them. These dysfunctional cells were then used to assess the effect of secretome (conditioned medium, CM) derived from mesenchymal stromal cells (MSCs) primed or not with neurotrophic factors. We found that priming of MSCs with neurotrophic factors enhances their neuroprotective potential. We demonstrate that when primed CM is given either as a single dose or in multiple doses, it restores neuro-regenesis and protects the stressed Neuro-2a cells from cell death. More importantly, the restoration of neuro-regenesis by primed CM is significantly higher as compared with the naive CM. These results clearly underscore the importance of priming the MSCs with neurotrophic factors for developing more effective therapeutic strategies to combat ND.
