BACKGROUND:The alteration of miR-146a-3p level is a common event in the pathogenesis of most neurological diseases,and the specific mechanism of miR-146a-3p regulation of astrocytes has not been studied. OBJECTIVE:To verify that miR-146a-3p regulates astrocyte proliferation,migration and apoptosis through insulin-like growth factor 1. METHODS:12 SD rats were divided into a sham operation group and a spinal cord injury group,with six rats in each group.RNA sequencing analysis was performed on the spinal cord tissues of all groups 2 weeks after surgery to screen out the differential genes(log2FC>2),and to select spinal cord injury-related genes(Score>20)in the Genecards database,and then to predict the target genes of miR-146a-3p by Targetscan.The intersection of three gene sets was obtained to screen out insulin-like growth factor 1 as one of the important target genes.qPCR,western blot assay and immunohistochemistry were performed to analyze the expression level of insulin-like growth factor 1 in spinal cord tissues.The primary astrocytes were divided into NC group,NC-mimics group and miR-146a-3p mimics group.Annexin-V/PI staining was used to detect cell apoptosis.CCK-8 assay was used to detect cell proliferation.Transwell assay was used to detect cell migration ability. RESULTS AND CONCLUSION:The expression of miR-146a-3p in the spinal cord tissue of the spinal cord injury group was lower than that of the sham operation group(P<0.05).The expression of insulin-like growth factor 1 in the spinal cord tissue of the spinal cord injury group was higher than that of the sham operation group(P<0.05).Compared with the NC group and NC-mimics group,the apoptotic rate of astrocytes was increased(P<0.01);the proliferation of astrocytes was decreased(P<0.01)and the number of migration was decreased(P<0.01)in the miR-146a-3p mimics group.To conclude,the expression of miR-146a-3p decreased and the expression of insulin-like growth factor 1 increased in spinal cord tissue after spinal cord injury.miR-146a-3p targeted regulation of insulin-like growth factor 1 in astrocytes,inhibited the proliferation and migration of astrocytes and promoted their apoptosis.

BACKGROUND:Establishing a nomogram prediction model for postoperative pulmonary infection in hip fractures and taking early intervention measures is crucial for improving patients'quality of life and reducing medical costs. OBJECTIVE:To construct a nomogram risk prediction model of postoperative pulmonary infection in elderly patients with hip fracture,and provide theoretical basis for feasible prevention and early intervention. METHODS:Case data of 305 elderly patients with hip fractures who underwent surgical treatment at Wuxi Traditional Chinese Medicine Hospital Affiliated to Nanjing University of Chinese Medicine between January and October 2020(training set)were retrospectively analyzed.Using univariate and multivariate logistic regression analysis and Hosmer-Lemeshow goodness of fit test,receiver operating characteristic curve was utilized to analyze the diagnostic predictive efficacy of independent risk factors and joint models for postoperative pulmonary infections.Tools glmnet,pROC,and rms in R Studio software were applied to construct a nomogram model for predicting the risk of postoperative pulmonary infection in elderly patients with hip fractures,and calibration curves were further drawn to verify the predictive ability of the nomogram model.Receiver operating characteristic curves,calibration curves,and decision curves were analyzed for 133 elderly patients with hip fractures(validation set)receiving surgery at the same hospital from November 2022 to March 2023 to further predict the predictive ability of the nomogram model. RESULTS AND CONCLUSION:(1)The postoperative pulmonary infection rate in elderly patients with hip fractures in this group was 9.18%(28/305).(2)Single factor and multivariate analysis,as well as forest plots,showed that preoperative hospitalization days,leukocyte count,hypersensitive C-reactive protein,and serum sodium levels were independent risk factors(P<0.05).The Hosmer-Lemeshow goodness of fit test showed good fit(χ2=4.57,P=0.803).Receiver operating characteristic curve analysis was conducted on the independent risk factors and their joint models mentioned above,and the differentiation of each independent risk factor and joint model was good,with statistical significance(P<0.05).(3)The graphical calibration method,C-index,and decision curve were used to validate the nomogram prediction model.The predicted calibration curve was located between the standard curve and the acceptable line,and the predicted risk of the nomogram model was consistent with the actual risk.(4)The validation set used receiver operating characteristic curve,graphic calibration method,and decision curve to validate the prediction model.The results showed good consistency with clinical practice,indicating that the model had a good fit.The nomogram risk prediction model constructed for postoperative pulmonary infection in elderly patients with hip fractures has good predictive performance.The use of the nomogram risk prediction model can screen high-risk populations and provide a theoretical basis for early intervention.