0.05). The titrimetric determination of standard solution containing different levels of chloride showed recovery rates of 98.0%～103.7%, relative standard deviation was 0.16%. Conclusion Automatic potentiometric titration was easy to grasp, rapid and accurate, which was a new analytical method worthy to be applied extensively.

Objective:To investigate the correlation between Piwi-interacting RNA (piRNA) and diabetic nephropathy (DN).Methods:The differential expression profiles of piRNAs in renal tissues of patients with DN (experimental group) and renal tissues adjacent to tumors of patients with renal tumors (control group) were detected by high-throughput sequencing. The biological function of differentially expressed piRNAs was described by gene ontology and Kyoto encyclopedia of genes and genomes enrichment analysis. Real-time fluorescence quantitative PCR was used to detect the serum expression level of target piRNAs in patients with DN. Spearman correlation analysis was used to analyze the correlation between serum target piRNAs and clinical indexes of patients with DN.Results:The results of high throughput sequencing showed that there were 127 differentially expressed piRNAs between DN group and control group, with screening condition of |log 2(fold changes)|≥2 and P<0.05. Among them, there were 99 up-regulated piRNAs and 28 down-regulated piRNAs. The top 5 up-regulated piRNAs were piRNA-hsa-161686, piRNA-hsa-349255, piRNA-hsa-355720, piRNA-hsa-151229 and piRNA-hsa-154959, respectively. The top 5 down-regulated piRNAs were piRNA-hsa-1929960, piRNA-hsa-174194, piRNA-hsa- 148658, piRNA-hsa-172594 and piRNA-hsa-172421, respectively. The PCR verification results of 3 up-regulated genes and 3 down-regulated genes with low P values and high expression levels showed that serum expression level of piRNA-hsa-77976 was significantly down-regulated in patients with DN ( P=0.028), which was consistent with that of sequencing, while the expression levels of other genes were inconsistent with the sequencing results or had no statistical significance. Bioinformatics analysis results predicted that significantly differentially expressed piRNAs might participate in the regulation of DN through Rap1, Ras, PI3K-Akt and axon guiding pathways. The results of correlation analysis showed that the expression level of piRNA-hsa-77976 was negatively correlated with blood urea nitrogen ( r=-0.584, P=0.028), serum creatinine ( r=-0.637, P=0.014), cystatin C ( r=-0.738, P=0.003) and β2 microglobulin ( r=-0.822, P<0.001), and positively correlated with estimated glomerular filtration rate ( r=0.661, P=0.010). Conclusion:The differential expression of piRNA is closely related to DN, and may be used as a new biomarker for the diagnosis and prognosis of DN.

OBJECTIVE: To investigate the role of the SIRT1/NF-κB pathway in mediating the effect of puerarin against lipopolysaccharide (LPS)-induced acute kidney injury (AKI). METHODS: Fifteen BALB/C mice were randomized into control group, LPS group and puerarin treatment group, and in the latter two groups, the mice were given an intraperitoneal injection of LPS (5 mg/kg), followed by daily injection of normal saline for 3 days or injection of puerarin (25 mg/kg) given 1 h later and then on a daily basis for 3 days. On day 5 after modeling, the kidney tissues were taken for histological observation and detection of cell apoptosis. The renal function indexes including urea nitrogen (BUN), serum creatinine (Scr) and kidney injury molecule 1 (KIM-1) and the levels of tumor necrosis factor (TNF-α) and interleukin 1β (IL-1β) were measured, and the expressions of SIRT1 and NF-κB-p65(acetyl K310) in the renal tissues were detected. RESULTS: Intraperitoneal injection of LPS caused obvious glomerular capillary dilatation, hyperemia, renal interstitial edema, and renal tubular epithelial cell swelling and deformation in the mice. The mouse models of LPS-induced AKI also showed significantly increased renal tubular injury score and renal cell apoptosis (P < 0.01) with increased serum levels of BUN, Scr, KIM-1, TNF-α and IL-1β (P < 0.01), enhanced renal expressions of TNF-α, IL-1β and NF-κB p65(acetyl K310) (P < 0.01) and lowered renal expression of SIRT1 (P < 0.05). Treatment with puerarin effectively alleviated LPS-induced renal interstitial edema and renal tubular epithelial cell shedding, lowered renal tubular injury score (P < 0.01) and renal cell apoptosis rate (P < 0.01), and decreased serum levels of BUN, Scr, KIM, TNF-α and IL-1β (P < 0.01). Puerarin treatment significantly reduced TNF-α, IL-1β and NF-κB p65 (acetyl K310) expression in the renal tissue (P < 0.05) and increased SIRT1 expression by 17% (P < 0.05) in the mouse models. CONCLUSION Puerarin can effectively alleviate LPS-induced AKI in mice possibly by modulating the SIRT1/NF-κB signaling pathway.
Animals ; Mice ; Mice, Inbred BALB C ; NF-kappa B ; Lipopolysaccharides ; Sirtuin 1 ; Tumor Necrosis Factor-alpha ; Acute Kidney Injury ; Disease Models, Animal ; Edema

Parvalbumin interneurons belong to the major types of GABAergic interneurons. Although the distribution and pathological alterations of parvalbumin interneuron somata have been widely studied, the distribution and vulnerability of the neurites and fibers extending from parvalbumin interneurons have not been detailly interrogated. Through the Cre recombinase-reporter system, we visualized parvalbumin-positive fibers and thoroughly investigated their spatial distribution in the mouse brain. We found that parvalbumin fibers are widely distributed in the brain with specific morphological characteristics in different regions, among which the cortex and thalamus exhibited the most intense parvalbumin signals. In regions such as the striatum and optic tract, even long-range thick parvalbumin projections were detected. Furthermore, in mouse models of temporal lobe epilepsy and Parkinson's disease, parvalbumin fibers suffered both massive and subtle morphological alterations. Our study provides an overview of parvalbumin fibers in the brain and emphasizes the potential pathological implications of parvalbumin fiber alterations.
Mice ; Animals ; Epilepsy, Temporal Lobe/pathology* ; Parvalbumins/metabolism* ; Parkinson Disease/pathology* ; Neurons/metabolism* ; Interneurons/physiology* ; Disease Models, Animal ; Brain/pathology*