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 vitromodel 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 to the naïve 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 neurogenesis.

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.

Endoplasmic reticulum (ER) stress-mediated accumulation of misfolded protein is a plausible stimulus for the pathogenesis of neurodegenerative diseases (ND). Under physiological conditions, ER stress activates the unfolded protein response (UPR) that repairs the misfolded proteins. Hence, to develop a physiologically relevant in vitro model system, we exposed Neuro-2a cells to an ER stress inducer which significantly affected the neurite outgrowth parameters and expression of neuronal markers without causing cell death in them. Here, we demonstrate that ER stress triggers early apoptosis, inflammation, and stress kinase activation in Neuro-2a cells. We have previously reported the regenerative potential of mesenchymal stromal cells (MSCs)-derived secretome in reversing the oxidative stress-induced loss of neurogenesis. The aim of this study was to investigate whether priming of MSCs with neurotrophic factors would enhance their neuroprotective potential, for which we used two distinct approaches. In the first approach, the ER-stressed Neuro-2a cells were subjected to a single exposure of conditioned medium (CM) derived from both naïve (naïve CM) and primed MSCs (primed CM), while in the second approach, the ER-stressed cells were subjected to multiple exposures of both naïve and primed CM. We observed that exposure of ER stress-induced Neuro-2a cells to primed CM significantly restored the neurite outgrowth parameters along with the expression of neuronal markers and also suppressed the induction of early apoptosis, inflammation, and activation of stress kinases. These results clearly underscore the importance of priming the MSCs with neurotrophic factors for developing more effective therapeutic strategies to combat ND.

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.