Biphasic Activation of Nuclear Factor-Kappa B in Experimental Models of Subarachnoid HemorrhageIn VivoandIn Vitro

Abstract

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.

Hydrogen-Rich Saline Attenuated Subarachnoid Hemorrhage-Induced Early Brain Injury in Rats by Suppressing Inflammatory Response: Possible Involvement of NF-κB Pathway and NLRP3 Inflammasome

“…As a well-established representative of inflammation, NF-κB has been reported to be activated after SAH [63][64][65]. Normally, NF-κB is maintained in the cytoplasm in a nonactivated status by binding with an inhibitor subunit IκB.…”

Nuclear factor‐κB/Bcl‐XL pathway is involved in the protective effect of hydrogen‐rich saline on the brain following experimental subarachnoid hemorrhage in rabbits

“…The same part of the occipital cortex was obtained, and nuclear protein of the brains was extracted and quantified as described for our previous study (You et al, ). Electrophoretic mobility shift assay (EMSA) was performed to assess the NF‐κB DNA‐binding activity via a commercial kit (Gel Shift Assay System; Promega, Madison, WI) following the methods in our laboratory.…”

“…The same procedures were performed as described previously (You et al, ). Briefly, total RNA was extracted using Trizol reagent (Invitrogen Life Technologies, Carlsbad, CA), according to the manufacturer's instructions.…”

Amelioration of oxidative stress and protection against early brain injury by astaxanthin after experimental subarachnoid hemorrhage

“…30 Animals were anesthetized with intramuscular ketamine (50 mg/kg) and xylazine (5 mg/kg), and then placed on a heated pad to keep the body temperature at 37°C during the experimental procedure. The hair on the neck was shaved, and then we sterilized the skin with 75% alcohol.…”