Mesenchymal stem cells-conditioned medium protects PC12 cells against 2,5-hexanedione-induced apoptosis via inhibiting mitochondria-dependent caspase 3 pathway

Abstract

Studies suggested that the conditioned medium of mesenchymal stem cells (MSC-CM) inhibited the increased apoptosis in various cells. However, there are no reports underlying the protection of MSC-CM against 2,5-hexanedione (HD)-induced apoptosis in neural cells. In the present study, the viability was observed in PC12 cells that received HD alone or with MSC-CM by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Apoptosis was estimated by Hoechst 33342 staining and flow cytometry. Mitochondrial transmembrane potential was examined by rhodamine 123. Moreover, we investigated the expression of Bax and Bcl-2, cytochrome c translocation, and caspase 3 activity by real-time polymerase chain reaction, Western blot, and immunochemistry. Nerve growth factor (NGF) was examined in MSCs and MSC-CM. Our results showed that MSC-CM promoted cell survival and reduced apoptosis in HD-exposed PC12 cells. Moreover, MSC-CM significantly reversed disturbance of Bax and Bcl-2, ameliorated disruption of mitochondrial transmembrane potential, and reduced release of cytochrome c and activity of caspase 3 in HD-exposed PC12 cells. In the meantime, NGF was detected in MSCs and MSC-CM. These findings demonstrate that MSC-CM protects against HD-induced apoptosis in PC12 cells via inhibiting mitochondrial pathway. Our results indicate that NGF in MSC-CM may be involved in the protection of MSC-CM against HD-induced apoptosis. Our study clarifies the protection of MSC-CM on HD neurotoxicity and its underlying mechanism.

Bone marrow mesenchymal stem cells attenuate 2,5-hexanedione-induced neuronal apoptosis through a NGF/AKT-dependent pathway

“…The disruption of this process is associated with a wide variety of neurodegenerative diseases, including HD-induced neuropathy 25 . Previously, we reported the protective effect of BMSC-CM against HD-induced apoptosis in PC12 cells, which was associated with reduction of Bax expression, Cyt C release and caspase-3 activity 9 . In this study, we delve deeper into investigating the anti-apoptotic and neuroprotective efficacy of BMSC in HD-intoxicated rats.…”

“…To further demonstrate the role of NGF in BMSC-afforded neuroprotection, we tested the impact of NGF neutralization on the anti-apoptotic effect of BMSC in an in vitro model of HD-induced apoptosis. We recently demonstrated that NGF released by BMSC accumulates in BMSC-CM and is capable of protecting PC12 cells against HD-induced apoptosis 9 . Consistent with previous report, the protective effect of BMSC-CM against HD-induced apoptosis was also observed in ventral spinal cord 4.1 (VSC4.1) cells, a cell line of dorsal motor neurons, by showing decreased number of TUNEL-positive cells and activity of caspase-3 compared with HD alone group ( Fig.…”

“…As early as 1996, Ogawa et al detected apoptosis in cultured dorsal root ganglion neurons treated with a low concentration of HD 7 . We recently also observed increased number of TUNEL-positive cells, expressions of Bax and cytochrome C (Cyt C) as well as activity of caspase-3 in HD-intoxicated PC12 cells 9 . Furthermore, Wistar rats intoxicated with 200 or 400 mg/kg HD displayed disturbance of Bcl-2 and Bax expressions as well as caspase-3 activity in nerve tissues 6 , indicating the involvement of apoptosis in vivo .…”

“…The improved outcome of BMSC transplantation was observed in multiple neurodegenerative disorders, including Alzheimer’s disease, Parkinson’s disease and Amyotrophic Lateral Sclerosis 12 . We have previously reported that conditioned medium prepared from BMSC (BMSC-CM) protects PC12 cells against HD-induced apoptosis 9 . However, the anti-apoptotic efficacy and underlying mechanisms of BMSC in HD-induced neuropathy remain unclear.…”

Bone marrow mesenchymal stem cells protect against n-hexane-induced neuropathy through beclin 1-independent inhibition of autophagy

“…Recently, we extended the therapeutic efficacy of BMSC into the neuropathy induced by occupational or environmental neurotoxicants, such as n -hexane. The potent protective effects displayed by conditioned medium prepared from BMSC (BMSC-CM) against HD-induced apoptosis were observed in PC12 cells, which was a rat pheochromocytoma cell line and possessed properties of neurons 9 . BMSC transplantation also attenuated HD-induced neuronal damage and improved the motor performance in rats 10 .…”