Relationship between BNIP3L and mitochondrial dysfunction in hippocampus of mice with sepsis-associated encephalopathy / 中华麻醉学杂志

ABSTRACT

Objective:To evaluate the relationship between B-cell lymphoma/adenovirus E1B19 kDa-interacting protein 3-like protein (BNIP3L)/adenovirus E1B-interacting protein and mitochondrial dysfunction in the hippocampus of mice with sepsis-associated encephalopathy (SAE).Methods:One hundred and eighty C57BL/6J mice, aged 6-8 weeks, weighing 20-25 g, were divided into 4 groups ( n=45 each) using a random number table method: control group (C group), sham operation group (Sham group), SAE group, and SAE+ BNIP3L agonist carfilzomib group (SC group). The sepsis model was developed by cecal ligation and puncture (CLP) in anesthetized animals. In SC group, carfilzomib 2 mg/kg was intraperitoneally injected at 2 h after CLP. Twenty mice in each group were selected, and the survival at 7 days after operation was recorded. Eight surviving mice in each group were selected at 1 week after CLP for Morris water maze test. The remaining mice were sacrificed at 24 h after surgery, and the hippocampal tissues were harvested for determination of the expression of BNIP3L (by immunofluorescence) and BNIP3L in mitochondrial protein (by Western blot) and for microscopic examination of the morphological structure of mitochondria. The mitochondrial ATP content was measured by fluorescein-fluorescence enzyme luminescence method, and the mitochondrial membrane potential (MMP) was measured by fluorescence spectrophotometry. Results:Compared with C and Sham groups, the survival rate was significantly decreased, the escape latency was prolonged, the time of staying at the original platform quadrant was shortened, and the number of crossing the original platform region was decreased, the expression of BNIP3L in the hippocampal mitochondria was down-regulated, the MMP and content of mitochondrial ATP were decreased ( P<0.05), the intensity of fluorescence of BNIP3L in the hippocampus was decreased, and the damage to mitochondrial ultrastructure was marked in SAE group. Compared with SAE group, the survival rate was significantly increased, the escape latency was shortened, the time of staying at the original platform quadrant was prolonged, and the number of crossing the original platform region was increased, the expression of BNIP3L in the hippocampal mitochondria was up-regulated, the MMP and content of mitochondrial ATP were increased ( P<0.05), the intensity of fluorescence of BNIP3L in the hippocampus was decreased, and the damage to mitochondrial ultrastructure was attenuated in SC group. Conclusions:BNIP3L-mediated mitochondrial dysfunction may be involved in the mechanism of SAE developed in mice.