DPYSL2 is a novel regulator for neural stem cell differentiation in rats: revealed by Panax notoginseng saponin administration.

BACKGROUND: The limited neuronal differentiation of the endogenous or grafted neural stem cells (NSCs) after brain injury hampers the clinic usage of NSCs. Panax notoginseng saponins (PNS) were extensively used for their clinical value, such as in controlling blood pressure, blood glucose, and inhibiting neuronal apoptosis and enhancing neuronal protection, but whether or not it exerts an effect in promoting neuronal differentiation of the endogenous NSCs is completely unclear and the potential underlying mechanism requires further exploration. METHODS: Firstly, we determined whether PNS could successfully induce NSCs to differentiate to neurons under the serum condition. Mass spectrometry and quantitative polymerase chain reaction (Q-PCR) were then performed to screen the differentially expressed proteins (genes) between the PNS + serum and serum control group, upon which dihydropyrimidinase-like 2 (DPYSL2), a possible candidate, was then selected for the subsequent research. To further investigate the actual role of DPYSL2 in the NSC differentiation, DPYSL2-expressing lentivirus was employed to obtain DPYSL2 overexpression in NSCs. DPYSL2-knockout rats were constructed to study its effects on hippocampal neural stem cells. Immunofluorescent staining was performed to identify the differentiation direction of NSCs after 7 days from DPYSL2 transfection, as well as those from DPYSL2-knockout rats. RESULTS: Seven differentially expressed protein spots were detected by PD Quest, and DPYSL2 was found as one of the key factors of NSC differentiation in a PNS-treated condition. The results of immunostaining further showed that mainly Tuj1 and GFAP-positive cells increased in the DPYSL2-overexpressed group, while both were depressed in the hippocampal NSCs in the DPYSL2-knockout rat. CONCLUSIONS: The present study revealed that the differentiation direction of NSCs could be enhanced through PNS administration, and the DPYSL2 is a key regulator in promoting NSC differentiation. These results not only emphasized the effect of PNS but also indicated DPYSL2 could be a novel target to enhance the NSC differentiation in future clinical trials.

The Expression implication of GDNF in ventral horn and associated remote cortex in rhesus monkeys with hemisected spinal cord injury.

OBJECTIVES: Glial cell line-derived neurotrophic factor (GDNF) can effectively promote axonal regeneration, limit axonal retraction, and produce a statistically significant improvement in motor recovery after spinal cord injury (SCI). However, the role in primate animals with SCI is not fully cognized. MATERIALS AND METHODS: 18 healthy juvenile rhesuses were divided randomly into six groups, observed during the periods of 24 hr, 7 days, 14 days, 1 month, 2 months, and 3 months after T11 hemisecting. The GDNF localization, changes in the injured region, and the remote associate cortex were detected by immunohistochemical staining. RESULTS: Immunohistochemical staining showed that GDNF was located in the cytoplasm and the neurite of the neurons. Following SCI, the number of GDNF positive neurons in the ventral horn and the caudal part near the lesion area were apparently reduced at detected time points (P<0.05). Moreover, the number in the rostral part of the ventral horn in 7 day, 14 day, and 1 month groups were fewer than those in the caudal part. Importantly, in the contralateral cortex motor area, the positive neurons decreased sharply after hemi-SCI, while gradually increased and went back to normal in 3 months after hemi-SCI. CONCLUSION: To sum up, GDNF disruption in neurons occurred after SCI especially in cortex motor area. Intrinsic GDNF in the spinal cord, plays an essential role in neuroplasticity. Thereafter extrinsic GDNF supplementing may be a useful strategy to promote recovery after SCI.

MicroRNA-127 targeting of mitoNEET inhibits neurite outgrowth, induces cell apoptosis and contributes to physiological dysfunction after spinal cord transection.

Neuroregeneration and apoptosis are two important pathophysiologic changes after spinal cord injury (SCI), but their underlying mechanisms remain unclear. MicroRNAs (miRNAs) play a crucial role in the regulation of neuroregeneration and neuronal apoptosis, research areas that have been greatly expanded in recent years. Here, using miRNA arrays to profile miRNA transcriptomes, we demonstrated that miR-127-3p was significantly down-regulated after spinal cord transection (SCT). Then, bioinformatics analyses and experimental detection showed that miR-127-3p exhibited specific effects on the regulation of neurite outgrowth and the induction of neuronal apoptosis by regulating the expression of the mitochondrial membrane protein mitoNEET. Moreover, knockdown of MitoNEET leaded to neuronal loss and apoptosis in primary cultured spinal neurons. This study therefore revealed that miR-127-3p, which targets mitoNEET, plays a vital role in regulating neurite outgrowth and neuronal apoptosis after SCT. Thus, modificatioin of the mitoNEET expression, such as mitoNEET activition may provide a new strategy for the treatment of SCI in preclinical trials.