An improved Brain-Derived Neurotrophic Factor (BDNF) bioactivity assay

Brain-Derived Neurotrophic )BDNF( is a member of the neurotrophin family of growth factors. Like other members of this family, BDNF supports neuron proliferation and survival. It plays crucial roles in cellular signaling (through the TrkB and LNGFR receptors) and regulates many aspects of the nervous system and neuronal development (e.g. axon and dendrite differentiation, synapse formation, and maturation). In addition, BDNF is involved in the pathogenesis of Alzheimer′s disease.

Herein, we developed an improved in-vitro BDNF activity assay (#B3795) by replacing the traditional method using the C6 cell line with human neuroblastoma SH-SY5Y cells. Using retinoic acid we induced SH-SY5Y cells to undergo controlled differentiation. Moreover, sequential exposure of these cells to retinoic acid followed by BDNF, in a serum-free medium, yields a homogeneous population of cells with definite neuronal morphology. During the process, the Trkb receptor is synthesized to preserve cell metabolism and neurites, which is directly visualized under microscopy demonstrating cells morphology changes to elongated structure with a visible neurites outgrowth.

The active form of recombinant human BDNF (27 kDa) is a dimer formed by two identical 119 amino acid subunits held together by strong hydrophobic interactions. Our assay is designed to maintain cell survival in an active BDNF-dependent manner, and thus lack or insufficient amount or inactive BDNF causes apoptotic cell death.

Thus we have developed an improved biological BDNF activity which is determined by its ability to stimulate the survival of human differentiated neuroblastoma cells.