Bcl-2 gene therapy for apoptosis following traumatic brain injury

To investigate the therapeutic effect of Bcl-2 fusion protein on apoptosis in brain following traumatic brain injury.

Bcl-2 gene was cloned by RT-PCR. Bcl-2 and EGFP genes were linked together and inserted into pAdeno-X vector. This recombinant vector was packaged into infectious adenovirus in HEK293 cells. Ninety Wistar rats were assigned randomly into experimental group (n=45) and control group (n=45). All rats were subjected to traumatic brain injury. Then recombinant adenovirus (for experimental group) or saline (for control group) was injected into the traumatic brain. The expression of Bcl-2 fusion protein was investigated by Western blotting, immunohistochemistry and fluorescence microscopy. Apoptosis in the injured brain was studied by TUNEL. Animals' behavior capacity was evaluated by tiltboard test.

In the experimental group, many fluorescent cells were found around the traumatic locus, which were also proven to be Bcl-2 positive by immunohistochemistry. On the contrary, few Bcl-2 positive cells and no fluorescent cell were detected in the control group. Bcl-2 expression of experimental group was much higher than that of control group, which was illustrated by Western blotting. The apoptosis index of experimental group was 0.027+/-0.005, and that of control group was 0.141+/-0.025 (P < 0.01). Two weeks after injury, animals of the experimental group behaved better than those of the control group.

A recombinant adenovirus vector expressing Bcl-2 fusion protein has been constructed. Bcl-2 fusion protein can suppress apoptosis and promote cell survival. Moreover, the behavior recovery of the injured animal is promoted. Bcl-2 fusion protein provides a way to track the target cells in vivo.