| Abstract Objective: To analyze the relationship between serum miR-17-5p expression and prognosis of patients with paraquat poisoning, and its effect on mitochondria apoptosis and endoplasmic reticulum stress in alveolar epithelial cells induced by paraquat. Methods: Real-time fluorescent quantitative PCR (RT-qPCR) was used to detect the expression level of serum miR-17-5p in paraquat poisoning patients and healthy controls, and the expression level of miR-17-5p in paraquat poisoning patients with different prognosis and poisoning severity was compared, and the relationship between the expression level of miR-17-5p and poisoning severity and prognosis of patients was analyzed. Cell counting kit (CCK8), flow cytometry and RT-qPCR were used to detect the effects of different concentrations of paraquat on the expression, proliferation and apoptosis of miR-17-5p in alveolar epithelial cells. Alveolar epithelial cells were divided into control group (Con), paraquat group, paraquat + miR-NC group, and paraquat + miR-17-5p group. The cell proliferation activity and apoptosis rate were detected by CCK8 and flow cytometry, and the expression level of miR-17-5p was detected by RT-qPCR. Western blot was used to detect the protein expression of cytochrome C (Cyt-C), activated caspase3 (Cleaved caspase3), Bcl-2 associated X protein (Bax), B-cell lymphoma/leukemic-2 (Bcl-2), protein kinase R-like endoplasmic reticulum kinase (PERK), activated transcription factor 6 (ATF4), and C/EBP homologous transcription protein (CHOP). Results: Compared with healthy controls, the expression level of miR-17-5p in serum of paraquat poisoning patients was significantly decreased (P< 0.05). The expression level of miR-17-5p in paraquat poisoning patients with different prognosis and poisoning severity showed statistical significance (P< 0.05). The AUC of serum miR-17-5p level predicting poor prognosis was 0.838, the specificity was 82.10%, and the sensitivity was 78.36%. Compared with 0 μmol/L group, the expression level and cell activity of miR-17-5p in 50, 100, 250, 500 and 1 000μmol/L paraquat groups were gradually decreased, and the apoptosis rate was gradually increased (P< 0.05). There was no significant difference between 500 and 1000μmol/L paraquat groups (P> 0.05). Compared with Con group, the expression level of miR-17-5p, Bcl-2 protein expression, and cell activity in paraquat group were significantly decreased, and the apoptosis rate, Cyt-C, Cleaved-caspase3, Bax, PERK, ATF4, and CHOP protein expression levels were significantly increased (P< 0.05). Compared with paraquat + miR-NC group, the expression level of miR-17-5p, the expression of Bcl-2 protein and cell activity in paraquat + miR-17-5p group were significantly increased. The expression of apoptosis rate, Cyt-C, Cleaved-caspase3, Bax, PERK, ATF4 and CHOP were significantly decreased (P< 0.05). Conclusion: The expression level of miR-17-5p in serum of paraquat poisoning patients was abnormally decreased, and it was closely related to the severity of poisoning and prognosis of patients. Updown of miR-17-5p alleviates paraquat-induced mitochondrial apoptosis and endoplasmic reticulum stress in alveolar epithelial cells. |
