Neuronal differentiation of PC12 cells induced by sciatic nerve and optic nerve conditioned medium.

BACKGROUND: Previous work has shown that optic nerve and sciatic nerve conditional medium had neurotrophic activity on neurons. In order to find if the optic nerve conditioned media (CM) had a similar activity to make PC12 cells differentiate as sciatic nerve CM did, we explored the neurotrophic activity in optic nerve CM in the same in vitro system and compared the neurotrophin expression levels in optic and sciatic nerves under both conditions. METHODS: PC12 cells were used to examine the effects of neurotrophins secreted by the sciatic nerve and optic nerve. RT-PCR and real-time QPCR showed that the sciatic nerve and optic nerve produced a range of neurotrophins including nerve growth factor (NGF), brain derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3). RESULTS: The effects of sciatic nerve and optic nerve CM on neurite outgrowth were tested against a range of neurotrophins, and they had different neuritogenic activities. Only NGF and sciatic nerve CM had obvious neuritogenic activities, although the concentration of NGF in the sciatic nerve CM was very low. CONCLUSIONS: Our experiment showed that sciatic nerve CM had a higher neurotrophic activity on PC12 cells than optic nerve CM. These results suggested that peripheral nervous system (PNS) and central nervous system (CNS) had different expression levels of neurotrophin, which may in part explain the lack of ability to regenerate the CNS.

[Traditional Chinese medicine and formulas of improving peripheral nerve regeneration].

Peripheral nerve impairment is a common complication in surgery, which repair relates directly to the recovery of motor function and sensory function. Clinical researchers always do nerve sutrure using microsurgical technique and adjuvant treatment to improve peripheral nerve regeneration. Western medicine used usually of adjuvant drugs, such as neurotrophic factors, are limited by their defects in clinical application. Traditional Chinese medicine classifies peripheral nerve impair as paralysis and arthromyodynia, considers that it is the result of defects of meridian and vessels, QI and blood, bones and muscles. So, drugs used usually are QI invigorating herbs, blood circulation promoting herbs for unblocking collaterals, and nourishing herbs, including astragali, hedysari, ginkgo leaf, angelica, danshen root, paeoniae radix, epimedium, chuanxiong, and common basic formulas, such as Buyang Huanwu decoction, Huangqi Guizhi Wuwu decoction, Huoxue Kangyuan decoction, compound radix hedysari, etc. To be ready for further study and development, we review the traditional Chinese medicine and formulas in this article.