Improvement effect of naloxone on brain injuries in rats by inhibiting NF-κB-mediated cu-proptosis

Xu Zehong; Sun Linlin

doi:10.3969/j.issn.1009-4237.2024.11.005

Abstract：Objective To explore whether naloxone can inhibit nuclear factor-κB(NF-κB)-mediated cu-proptosis and improve brain injuries in rats.Methods A total of 48 healthy SD rats(14-week-old,male gender and weight of 250-335 g)were selected and randomly divided into 3 groups(n=16 for each):control group(no injury+normal saline),model group(brain injury+normal saline),and naloxone group(brain injury+naloxone).The brain injury model was established by Fenny's method after grouping.After modeling,rats in the naloxone group received intraperitoneal injection of 1 mg/kg naloxone every 12 h,while those in the control and model groups were injected with an equal amount of normal saline.The behavior ability of all the rats was recorded by shuttle box experiment,the content of Cu2+in rat cerebral cortex was measured by plasma mass spectrometry,and the expressions of NF-κB,ferredoxin 1(FDX1)and dihydrolipoamide S-acetyltransferase(DLAT)proteins in rat cerebral cortex were detected by immunohistochemistry and western blot.Results Compared to the control group,rats in the model group showed worse activities,but those in the naloxone group revealed much better activities than the model group with naloxone treatment(P＜0.05).For the control,model and naloxone groups,the content of Cu2+(μg/L)was respectively 1.34±0.28,2.33±0.49,and 1.90±0.42;the average optical density of NF-κB was respectively 0.016±0.007,0.035±0.015,and 0.028±0.014,of FDX1 was 0.018±0.012,0.044±0.013,and 0.031±0.015,of DLAT was 0.014±0.006,0.036±0.009,and 0.026±0.008,which were all significantly increased after brain injuries in model group but largely reduced after naloxone treatment in naloxone group(all P＜0.05).Western blot showed consistent results:significantly higher expressions in model group but largely decreased expressions in naloxone group(NF-κB:0.67±0.06,0.96±0.07,0.86±0.05;FDX1:0.78±0.06,1.09±0.10,0.88±0.09;DLAT:0.51±0.03,0.87±0.04,0.71±0.05,all P＜0.05 for control group vs.model group and model group vs.naloxone group).Conclusion Naloxone inhibited NF-κB and further cuproptosis in rat brain tissue to protect the brain after trauma.