Objective To investigate changes in gut microbiota during diabetic nephropathy(DN)pro-gression using 16S rDNA sequencing technology.Methods A total of 90 male SD rats were randomly divided into a normal control group(n=10,no modeling,regular feeding)and a model group(diabetes model).The diabetes model was established by a single intraperitoneal injection of streptozotocin(STZ)at 60 mg/kg,with regular feeding.According to the feeding time after modeling,the rats were divided into 2-week,4-week,8-week,and 12-week model groups(fed for 2,4,8,and 12 weeks after model establishment),with 20 rats in each group.Blood urea nitrogen(BUN)was measured using the urease method,serum creatinine(Scr)was deter-mined by the picric acid method,and ELISA was used to detect urinary kidney injury molecule-1(KIM-1)and neutrophil gelatinase-associated lipocalin(NGAL)levels.HE,PAS,and Masson staining were used to observe renal tissue pathological changes.Gut microbiota was collected from the rats,and 16S rDNA gene sequencing was used to analyze the gut microbiota to understand changes in the gut microbiota.Results Compared with the normal control group,the levels of KIM-1 and NGAL in urine of rats in all model groups were significantly increased(P<0.05).Pathological staining results showed that,compared with the normal control group,rats in all model groups exhibited diffuse thickening of the glomerular basement membrane and pathological chan-ges such as local necrosis and vacuolar degeneration in renal tubular epithelial cells.16S rDNA sequencing re-sults indicated that the abundance and structure of intestinal microbiota in rats of all model groups changed.Compared with the normal control group,in the 8-week and 12-week model groups,the relative abundance of Bacteroides and Akkermansia decreased,while the relative abundance of Roseburia,Alloprevotella,Prevotel-laceae-Ga6A1,and Ruminococcaceae UCG-005 increased.Compared with the normal control group,in the 12-week model group,the abundance of Akkermansia decreased and that of Prevotellaceae-NK3B31 increased.Conclusion The abundance and structure of gut microbial community in DN rats under conventional feeding at different time points change significantly,further confirming the"gut-kidney axis"theory.

Objective:To investigate the effect of nuclear factor E2-related factor 2 (Nrf2) on the cellular tight junction protein Claudin-18 in endotoxin-induced acute lung injury (ALI).Methods:Eighteen healthy male C57BL/6 mice were divided into control group, endotoxin-induced ALI model group (ALI group) and Nrf2 activator tert-butylhydroquinone (tBHQ) pretreatment group (tBHQ+ALI group) according to random number table method, with 6 mice in each group. Mice endotoxin-induced ALI model was reproduced by intraperitoneal injection of lipopolysaccharide (LPS, 15 mg/kg), and the mice in the control group was injected with an equal amount of phosphate buffer solution (PBS). The mice in the tBHQ+ALI group received three intraperitoneal injections of tBHQ (a total of 50 mg/kg) at an interval of 1 hour before molding. The last injection of tBHQ was accompanied by LPS of 15 mg/kg. The mice in the control group and model group were given equal amounts of PBS, and PBS or LPS was given at the last injection. The mice were sacrificed at 12 hours after LPS injection to take lung tissues. After the lung tissue was stained with hematoxylin-eosin (HE) staining, the pathological changes were observed under light microscopy, and the lung injury score was calculated. The lung wet/dry ratio (W/D) was determined. Nrf2 protein expression in the lung tissue was detected by Western blotting. Positive expression of Claudin-18 in the lung tissue was determined by immunohistochemistry.Results:The lung tissue showed normal structure, without significant pathological change in the control group. Compared with the control group, the alveolar septum widened accompanied by inflammatory cell infiltration, capillary hyperemia and tissue edema in the ALI group, the lung injury score and lung W/D ratio were significantly increased (lung injury score: 6.50±1.05 vs. 1.83±0.75, lung W/D ratio: 3.79±0.22 vs. 3.20±0.14, both P < 0.01), and the Nrf2 protein expression and Claudin-18 positive expression in the lung tissue were significantly lowered [Nrf2 protein (Nrf2/β-actin): 0.41±0.33 vs. 1.22±0.33, Claudin-18 ( A value): 0.28±0.07 vs. 0.44±0.10, both P < 0.05]. After tBHQ pretreatment, the degree of lung histopathological injury was significantly reduced compared with the ALI group, the alveolar space slightly abnormal, inflammatory cell infiltration and tissue edema reduced, the lung injury score and lung W/D ratio were significantly decreased (lung injury score: 3.00±0.89 vs. 6.50±1.05, lung W/D ratio: 3.28±0.19 vs. 3.79±0.22, both P < 0.01), and Nrf2 protein expression and Claudin-18 positive expression in the lung tissue were significantly increased [Nrf2 protein (Nrf2/β-actin): 1.26±0.09 vs. 0.41±0.33, Claudin-18 ( A valure): 0.45±0.04 vs. 0.28±0.07, both P < 0.05]. Conclusion:Nrf2 alleviated pulmonary edema and improved endotoxin-induced ALI by up-regulating Claudin-18 expression.

OBJECTIVE: To analyze the composition and metabolites of gut microbiota in septic rats by fecal 16s rRNA sequencing and untargeted metabolomics, and to preliminarily explore the effect and potential mechanism of gut microbiota and its metabolites on inflammatory response and multiple organ damage in sepsis. METHODS: Ten males healthy male Wistar rats were randomly divided into a sham operated group (Sham group) and sepsis model group (CLP group) using a random number table method, with 5 rats in each group. A rat sepsis model was established by cecal ligation and perforation (CLP) method. The animals were sacrificed 24 hours after modeling, the levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in peripheral blood were detected by enzyme-linked immunosorbent assay (ELISA). Hematoxylin-eosin (HE) staining was used to observe the pathological changes of lung and kidney tissues, and the pathological scores were evaluated. Fecal samples were collected, and 16s rRNA high-throughput sequencing and non-targeted metabolomics were used to screen microbiota, metabolites and potential signal pathways that may play an important role in disease outcomes. Spearman correlation analysis was conducted to jointly analyze the gut microbiota and non-targeted metabolism. RESULTS: Compared with the Sham group, the degree of pathological damage to lung and kidney tissues in the CLP group was significantly increased (lung tissue score: 3.60±0.80 vs. 0.00±0.00, kidney tissue score: 2.40±0.80 vs. 0.00±0.00, both P < 0.01), the level of IL-6 and TNF-α in peripheral blood significantly increased [TNF-α (ng/L): 248.12±55.98 vs. 143.28±36.57, IL-6 (ng/L): 260.26±39.47 vs. 116.01±26.43, both P < 0.05], the species diversity of intestinal flora of rats in the CLP group was significantly reduced, the relative abundance of Morganella, Bacteroides and Escherichia-Shigella were significantly increased, and the relative abundance of Lachnospiraceae NK4A136, Ruminococcus, Romboutsia and Roseburia were significantly reduced. In addition, the biosynthesis and bile secretion of phenylalanine, tyrosine, and tryptophan in the gut microbiota of the CLP group were significantly increased, while the biosynthesis of secondary bile acids was significantly reduced. There was a significant correlation between differential metabolites and differential microbiota. CONCLUSIONS Sepsis can cause significant changes in the characteristics of gut microbiota and fecal metabolites in rats, which provides a basis for translational research to seek new targets for the treatment of sepsis.
Rats ; Male ; Animals ; Tumor Necrosis Factor-alpha ; RNA, Ribosomal, 16S ; Gastrointestinal Microbiome ; Interleukin-6 ; Rats, Wistar ; Sepsis

Objective To study the role of different dose nicorandil in prevention of CIN in elderly CHD patients.Methods One hundred and twenty-one elderly CHD patients were divided into standard dose nicorandil treatment group (n=42),5 mg nicorandil treatment group (n=39) and 10 mg nicorandil treatment group (n=40).Their Scr levels,and eGFR were measured for 3 days before and after PCI.The urine KIM-1 and NGAL levels were measured before and 24 h after PCI.The incidence of CIN and adverse reactions were compared in 3 groups.Results The incidence of (IN and the eGFR ≥25％ were significantly lower,the serum Scr level was significantly lower while the eGFR was significantly higher in 5 mg and 10 mg nicorandil treatment groups than in standard dose nicorandil treatment group on days 1 and 2 after PCI (P＜0.05,P＜0.01).The serum Scr level was significantly lower while the eGFR was significantly higher in 10 mg nicorandil treatment group than in 5 mg nicorandil treatment group on day 2 after PCI (P＜0.05).The urine KIM-1 and NGAL level were significantly lower in 10 mg nicorandil treatment group than in standard dose nicorandil treatment group and 5 mg nicorandil treatment group at 24 h after PCI (2.77±0.33 μg/L vs 5.63±0.27 μg/L,4.82±0.32 μg/L,P＜0.05;41.64±8.42 μg/L vs 66.51±10.72 μg/L,57.11±9.67 μg/L,P＜0.05).Conclusion Different oral doses of nicorandil play a role in prevention of CIN and 10 mg nicorandil plays a greater role than standard dose nicorandil and 5 mg nicorandil in prevention of CIN in elderly CHD patients undergoing PCI.