Biphasic Activation of Nuclear Factor-Kappa B in Experimental Models of Subarachnoid Hemorrhage In Vivo and In Vitro

الملخص EN

It has been proven that nuclear factor-kappa B (NF-κB) is activated as a well-known transcription factor after subarachnoid hemorrhage (SAH).

However, the panoramic view of NF-κB activity after SAH remained obscure.

Cultured neurons were signed into control group and six hemoglobin- (Hb-) incubated groups.

One-hemorrhage rabbit SAH model was produced, and the rabbits were divided randomly into one control group and five SAH groups.

NF-κB activity was detected by electrophoretic mobility shift assay (EMSA) and immunohistochemistry.

Real-time polymerase chain reaction (PCR) was performed to assess the downstream genes of NF-κB.

NeuN immunofluorescence and lactate dehydrogenase (LDH) quantification were used to estimate the neuron injury.

Double drastically elevated NF-κB activity peaks were detected in rabbit brains and cultured neurons.

The downstream gene expressions showed an accordant phase peaks.

NeuN-positive cells decreased significantly in day 3 and day 10 groups.

LDH leakage exhibited a significant increase in Hb-incubated groups, but no significant difference was found between the Hb incubated groups.

These results suggested that biphasic increasing of NF-κB activity was induced after SAH, and the early NF-κB activity peak indicated the injury role on neurons; however, the late peak might not be involved in the deteriorated effect on neurons.