Effects of Rab7 gene up-regulation on renal fibrosis induced by unilateral ureteral obstruction

Rab7, an important member of the Rab family, is closely related to autophagy, endocytosis, apoptosis, and tumor suppression but few studies have described its association with renal fibrosis. In the early stage, our group studied the effects of Rab7 on production and degradation of extracellular matrix in hypoxic renal tubular epithelial cells. Because cell culture in vitro is different from the environment in vivo, it is urgent to understand the effects in vivo. In our current study, we established a renal fibrosis model in Rab7-knock-in mice (prepared by CRISPR/Cas9 technology) and wild type (WT) C57BL/6 mice using unilateral ureteral obstruction (UUO). Seven and 14 days after UUO, the expression of the Rab7 protein in WT mice, as well as the autophagic activity, renal function, and the degree of renal fibrosis in WT and Rab7-knock-in mice were examined by blood biochemical assay, hematoxylin-eosin and Masson staining, immunohistochemistry, and western blotting. We found that the Rab7 expression in WT mice increased over time. Furthermore, the autophagic activity constantly increased in both groups, although it was higher in the Rab7-knock-in mice than in the WT mice at the same time point. Seven days after UUO, the degree of renal fibrosis was milder in the Rab7-knock-in mice than in the WT mice, but it became more severe 14 days after surgery. Similar results were found for renal function. Therefore, Rab7 suppressed renal fibrosis in mice initially, but eventually it aggravated fibrosis with the activation of autophagy.

Exogenous hydrogen sulfide reduces vascular aging in D-galactose-induced subacute aging rats / 生理学报

The present study was aimed to observe the protective effect of exogenous hydrogen sulfide (H₂S) on vascular structural and functional changes of aorta in D-galactose-induced subacute aging rats. Adult male SD rats were randomly divided to five groups: the vehicle group, the D-galactose (D-gal) group, and the three NaHS groups treated with low (1 μmol·kg⁻¹·d⁻¹), middle (10 μmol·kg⁻¹·d⁻¹) or high (100 μmol·kg⁻¹·d⁻¹) dose of NaHS respectively. The D-gal group rats were given subcutaneously injection of 125 mg/kg D-gal per day for eight weeks to induce subacute aging model. In the NaHS group, D-gal was administered as above but with NaHS intraperitoneally injected at a dosage of 1, 10, 100 μmol·kg⁻¹·d⁻¹ respectively. Equivalent volumes of saline were administered per day for eight weeks in vehicle group. Morphological changes of aorta were observed by HE and Masson staining. The level of H₂S in serum, the activity of superoxide dismutase (SOD) and the content of malondialdehyde (MDA), as well as anti-superoxide anions in vascular tissue were determined by spectrophotometry. Angiotensin II (AngII) levels in plasma were measured using competitive enzyme immunoassay. The expression of angiotensin II type 1 receptor (AT1R) in aorta was determined by Western blot. The results showed that the aging aortic morphologic changes in model rats were ameliorated in NaHS groups. Decreased vascular endothelial exfoliative cells and vascular smooth muscle cell (SMC) proliferation were shown in NaHS groups by HE staining. Masson staining analysis showed reduced relative contents of collagen fibers (P < 0.05) and SMC (P < 0.05) in NaHS groups. Compared to vehicle group, serum concentration of H₂S in D-gal group was decreased, while it was increased in NaHS groups after treatment with NaHS (P < 0.05). In the D-gal group, the concentration of AngII in plasma was significantly increased compared with that in vehicle group, while it was decreased in NaHS groups (P < 0.05). Moreover, levels of vascular tissue anti-superoxide anion and the activity of SOD were obviously higher, MDA was significantly lower in all NaHS treated groups than those in the D-gal group respectively (P < 0.05). Western blot analysis showed that the expression of AT1R was increased in D-gal group compared with that in vehicle group, while it was decreased after treatment with NaHS compared with that in D-gal group (P < 0.05). These results suggest that exogenous H₂S can ameliorate the age-related changes of aortic morphology, decrease the concentration of AngII in plasma, down-regulate the expression of AT1R in vascular tissue, and mitigate the level of oxidative stress. These changes delay the vascular aging in aging rats ultimately.

Identification of Haemophilus spp. from clinical specimens by biochemical tests compared with PCR method

Haemophilus influenzae is a part of normal upper respiratory flora of human, which can cause a wide variety of infections. Other members of genus Haemophilus rarely cause human infection but are frequently isolated from clinical specimens, such as sputum. The pathogenicity between H. influenzae and other Haemophilus species is different therefore a reliable method for identification of H. influenzae is essential. The aim of this study was to compare the identification methods for Haemophilus by four phenotypic tests with that by a PCR-based method. A total of 101 Haemophilus isolates were identified by biochemical tests and the XV requirement test by using XV paper strip technique, porphyrin test and Staphylococcus streak technique. The PCR-based method was performed using specific primers for 16SrDNA, p6 genes of H. influenzae and sodA gene of H. parainfluenzae. Using the XV paper strip technique, porphyrin test and biochemical tests, 88 and 13 isolates were identified as H. influenzae and H. parainfluenzae respectively, whereas 54 H. influenzae and 47 H. parainfluenzae were identified by using Staphylococcus streak technique (66.4 % agreement with that of the three tests). The PCR-based method revealed that 83 H. influenzae and 12 H. parainfluenzae were identified, whereas 6 isolates could not be categorized into both species. This study showed that identification of Haemophilus by the XV paper strip technique, porphyrin test and biochemical test gave 93.1 % agreement with that of the PCR method, whereas the Staphylococcus streak technique gave only 71.3 % agreement.