Role of NF-κB-MMP-9 signaling pathway on delayed encephalopathy after acute carbon monoxide poisoning / 实用医学杂志

ABSTRACT

Objective To investigate the role of nuclear transcription factor kappa B (NF-κB) -matrix metalloproteinase-9 (MMP-9) signaling pathway in delayed encephalopathy after acute carbon monoxide poisoning (DEACMP). Methods 150 male SD rats were randomly assigned to air control group (AC group) , CO poisoning group (CO group) , pyrrolidine thiocarbamate (PDTC) + CO poisoning group (PC group). DEACMP model was reconstructed by modified intraperitoneal injections. The 1, 3, 7, 14, and 21 d after intraperitoneal injection were observed here by different approaches. Morris water maze test was used to test the learning and memory ability of rats.HE staining was used to observe the morphology of hippocampal CA3 cells. Immunofluorescence and Western Blot methods were used to detect the expression of NF-κB and MMP-9. RT-PCR was used to measure the expression of MMP-9 mRN A. Transmission electron microscopy was used to observe the ultrastructure of synapses. Results After14 days, the average intubation period of CO group was longer than that of AC group (P < 0.05) , and that of PC group was shorter than that of CO group (P < 0.05). However, average intubation period of PC group was longer than that of AC group (P< 0.05). In CO group, the expression of NF-κB in hippocampus increased (day 1). At day 3, the expression of NF-κB rapidly increased. The expression of MMP-9 gene and protein increased in the first three days and then decreased thereafter. The expression of NF-κB and MMP-9 in PC group was lower than that in CO group (P < 0.05) , while it was higher than AC group (P < 0.05). The peak value of apoptosis in CO group was delayed to 7-14 d after exposure, the apoptotic cells in PC group decreased significantly, and it was obvious on the 14 th day.Electron microscopy showed that the damage of synapses ultrastructure in CO group was significantly heavier than that in PC group on the 14 th day. Conclusions NF-κB-MMP-9 signal pathway leads to DEACMP, and PDTC could alleviate the impairment of learning and memory ability in rats with acute CO poisoning.