Alteration of NF-kB and TNF-α mRNA and protein in hippocampus in the chronic constrictive injury model of rats / 中华行为医学与脑科学杂志

ABSTRACT

Objective To investigate the alteration of nuclear factor kappa B( NF-κB) and tumor necrosis factor-a (TNF-α) mRNA and protein in hippocampus in chronic constrictive injury (CCI) model of rats. Methods Seventy-six male Wistar rats were randomly divided into 2 groups ( n = 38) the CCI group which received the chronic constriction injury and the sham group which received the sham operation as control. The mechanical and thermal nociceptive thresholds were assessed with paw withdrawal latency (PWL) to von Frey filaments and radiant heat at 1d before and ld,4d,7d,14d and 28d after CCI operation. Five animals were sacrificed at each time point for real-time polymerase chain reaction (real-time PCR) and another three animals sacrificed at 7d postoperation for immunofluorescence histochemical staining. Results The thresholds to mechanical and thermal stimuli decreased obviously after operation in CCI group. The expressions of TNF-α and NF-κB mRNA began to increase at ld( (2.079 ±0. 104)times and 4d( ( 1.640 ± 0.064) times) after operation and reached the peak at 7d ((2.748 ±0.147)times, (2.010 ±0.096)times) ,then the expressions of TNF-a mRNA began to decrease,while the expressions of NF-kB mRNA maintained at a high level throughout the experiment. The result of immunofluorescence histochemical staining revealed that NF-kB and TNF-α protein expressions at 7 day increased significantly on the hippocampus,which was consisted with NF-κB and TNF-a mRNA levels. Conclusion The activation NF-κB and TNF-α in hippocampus may be involved in the procession of neuropathic pain.