Ferroptosis was involved in the oleic acid-induced acute lung injury in mice / 生理学报

The aim of the present study was to investigate the role of ferroptosis in acute lung injury (ALI) mouse model induced by oleic acid (OA). ALI was induced in the mice via the lateral tail vein injection of pure OA. The histopathological score of lung, lung wet-dry weight ratio and the protein content of bronchoalveolar lavage fluid (BALF) were used as the evaluation indexes of ALI. Iron concentration, glutathione (GSH) and malondialdehyde (MDA) contents in the lung tissues were measured using corresponding assay kits. The ultrastructure of pulmonary cells was observed by transmission electron microscope (TEM), and the expression level of prostaglandin-endoperoxide synthase 2 (PTGS2) mRNA was detected by quantitative polymerase chain reaction (q-PCR). Protein expression levels of glutathione peroxidase 4 (GPX4), ferritin and transferrin receptor 1 (TfR1) in lung tissues were determined by Western blot. The results showed that histopathological scores of lung tissues, lung wet-dry weight ratio and protein in BALF in the OA group were higher than those of the control group. In the OA group, the mitochondria of pulmonary cells were shrunken, and the mitochondrial membrane was ruptured. The expression level of PTGS2 mRNA in the OA group was seven folds over that in the control group. Iron overload, GSH depletion and accumulation of MDA were observed in the OA group. Compared with the control group, the protein expression levels of GPX4 and ferritin in lung tissue were down-regulated in the OA group. These results suggest that ferroptosis plays a potential role in the pathogenesis of ALI in our mouse model, which may provide new insights for development of new drugs for ALI.

Activation of necroptosis in a rat model of acute respiratory distress syndrome induced by oleic acid / 生理学报

The present study was aimed to investigate the role of necroptosis in the pathogenesis of acute respiratory distress syndrome (ARDS). The rat model of ARDS was induced by intravenous injection of oleic acid (OA), and observed for 4 h. The lung injury was evaluated by arterial blood gas, lung wet-dry weight ratio (W/D) and histological analyses. Simultaneously, bronchoalveolar lavage fluid (BALF) was collected for total and differential cell analysis and total protein determination. Tumor necrosis factor alpha (TNF-α) level in BALF was determined with a rat TNF-α ELISA kit. Expressions of receptor interacting protein kinase 1 (RIPK1), RIPK3 and mixed lineage kinase domain-like protein (MLKL) in lung tissue were determined by Western blot and immunohistochemical staining. The interaction between RIPK1 and RIPK3 was explored by immunoprecipitation. The results showed that, compared with those in control group, total white blood cells count (WBC), polymorphonuclear percentage (PMN%), total protein concentration, TNF-α level in BALF, W/D, and the alveolar-arterial oxygen tension difference (P(A-a)O) in OA group were significantly increased at 4 h after OA injection. Western blot and immunostaining further showed remarkably increased expressions of RIPK1, RIPK3 and MLKL in lung tissue from OA group. Additionally, immunoprecipitation results indicated an enforced interaction between RIPK1 and RIPK3 in OA group. Collectively, the TNF-α level in BALF and the RIPK1-RIPK3-MLKL signaling pathway in lung tissue were found to be upregulated and activated with the process of ARDS. These findings implicate that RIPK1/RIPK3-mediated necroptosis plays a possible role in the pathogenesis of ARDS, which may provide a new idea to develop novel drugs for the therapy of ARDS.

CyPA-CD147-ERK1/2-cyclin D2 signaling pathway is upregulated during rat left ventricular hypertrophy / 生理学报

The changes of serum cyclophilin A (CyPA), its receptor CD147 and the downstream signaling pathway during the process of cardiac hypertrophy remain unknown. The present study aims to investigate the relationships between CyPA-CD147-ERK1/2-cyclin D2 signaling pathway and the development of cardiac hypertrophy. Left ventricular hypertrophy was prepared by 2-kidney, 2-clip in Sprague-Dawley rats and observed for 1 week, 4 and 8 weeks. Left ventricular hypertrophy was evaluated by ratio of left ventricular heart weight to body weight (LVW/BW) and cardiomyocyte cross sectional area (CSA). CyPA levels in serum were determined with a rat CyPA ELISA kit. Expressions of CyPA, CD147, phospho-ERK1/2 and cyclin D2 in left ventricular myocytes were determined by Western blot and immunostaining. Compared with sham groups, systolic blood pressure reached hypertensive levels at 4 weeks in 2K2C groups. LVW/BW and CSA in 2K2C groups were significantly increased at 4 and 8 weeks after clipping. ELISA results indicated a prominent increase in serum CyPA level associated with the degree of left ventricular hypertrophy. Western blot revealed that the expressions of CyPA, CD147, phospho-ERK1/2 and cyclin D2 in left ventricular tissues were also remarkably increased as the cardiac hypertrophy developed. The results of the present study demonstrates that serum CyPA and CyPA-CD147-ERK1/2-cyclin D2 signaling pathway in ventricular tissues are time-dependently upregulated and activated with the process of left ventricular hypertrophy. These data suggest that CyPA-CD147 signaling cascade might play a role in the pathogenesis of left ventricular hypertrophy, and CyPA might be a prognosticator of the degree of left ventricular hypertrophy.

Cultivation of Medical Students' Comprehensive Abilities by Reforming Functional Experiment Teaching / 中华医学教育探索杂志

To lead students to think actively and develop their innovative abilities,we adopted approaches of self-study,question and answer teaching as well as presentation and discussion teaching,perfected teaching contents and system of basic experiments, formed comprehensive experiments and exploratory experiments,established excellent courseware and carried out network education constructed scientific and reasonable exam systems.These reforms are strong guarantees for cultivating high quality talents in the 21st century.