Effect of NGF From Venom of Chinese Cobra (Naja Atra)on Chondrocytes Proliferation and Metabolism In Vitro.

Autologous chondrocyte implantation (ACI) is promising strategy for cartilage repair. However, chondrocyte phenotype is easily lost when expanded in vitro which defined as "dedifferentiation." To ensure successful therapy, an effective pro-chondrogenic agent is necessary to overcome the obstacle of limited cell numbers in the restoration process, and dedifferentiation is a prerequisite. In the present study, we investigated the chondro-protective effect of NGF from Chinese cobra venom on human chondrocytes by determination of its specific effect on cell viability, proliferation, morphology, GAG production, and cartilage specific gene expression. The results suggested that NGF showed no cytotoxicity to chondrocytes below the concentration of 16 µg/mL. DNA and glycosaminoglycan (GAG) content were, respectively, improved in NGF groups comparing to the control (P < 0.05). NGF up-regulate the gene expression of ACAN, SOX9, and COL2A1 while down-regulate the expression level of COL1A1 (P < 0.05). Moreover, the results of viability assay, hematoxylin-eosin, safranin O, and immunohistochemical staining also suggested better performances in NGF groups. NGF of 6 µg/mL shown lower cytotoxicity on chondrocytes, more glycosaminoglycans (GAGs) synthesis and up-regulated chondrogenic gene expression. This study may provide a basis for the development of a novel agent for the treatment of articular cartilage defects. J. Cell. Biochem. 118: 4308-4316, 2017. © 2017 Wiley Periodicals, Inc.