Endothelial injury by circulating IgA1 complex through the activation of mesangial cells in IgA nephropathy.

BACKGROUND: IgA nephropathy (IgAN) commonly entails arteriolar microangiopathic (MA) lesions of the kidneys. The most significant reason for MA lesions is endothelial injury, although the mechanism of injury to the vascular endothelium is not clear. MATERIALS AND METHODS: 59 patients with IgAN and 19 healthy controls were included for measuring the blood von Willebrand factor (vWF), soluble vascular cell adhesion molecule-1 (sVCAM1), and heparin-binding EGF-like growth factor (HB-EGF) by ELISA. Circulating IgA1 (cIgA1) was isolated from 12 patients with primary IgAN and 10 healthy controls. Then, the supernatant of growth-arrested human mesangial cells (HMCs) in a medium with cIgA1 was used to prepare the cIgA1-human mesangial cell medium (cIgA1-HMCM). Human umbilical vein endothelial cells (HUVECs) were grown in this medium along with or without Panax notoginseng saponins (PNS). ELISA was employed for the quantification of IL-6, CXCL1 and HB-EGF levels in cIgA1-HMCM, vWF, sVCAM1, and HB-EGF in the HUVEC medium. RESULTS: The concentration of vWF, sVCAM-1, and HB-EGF was higher in the patients than in the healthy participants. The expressions of IL-6 and CXCL1 in HMCM were significantly higher in cIgA1 from patients with IgAN (IgAN-cIgA1) than from healthy controls. Levels of vWF, sVCAM-1, and HB-EGF induced by conditioned HMCM treated with IgAN-cIgA1 (IgAN-HMCM) were conspicuously more than those induced in healthy controls-HMCM (HC-HMCM). After culturing HUVECs in IgAN-HMCM and PNS, the vWF, sVCAM-1 and HB-EGF were remarkably low in the supernatants of cells grown in IgAN-HMCM+PNS compared to those grown in IgAN-HMCM only. CONCLUSION: Activation of mesangial cells in vitro may occur by cIgA1 and, thus, cause endothelial cell injury via inflammation factors.

Simiaosan alleviates the symptoms of gouty arthritis via the NALP3/IL­1ß pathway.

Previous studies have suggested that the herbal medicine simiaosan has beneficial effects on gouty arthritis (GA), for which conventional Western medicines are insufficient (particularly in cases of multiple episodes). The objective of the present study was to investigate the mechanism by which simiaosan alleviated the symptoms of GA. Sprague­Dawley rat models of acute GA were successfully established, as verified by pathological analyses. Additionally, an NLR family pyrin domain containing 3 (NLRP3) overexpression vector was constructed and a high transfection efficiency was confirmed by reverse transcription PCR. The following five treatment groups were established: i) Normal control; ii) model + saline; iii) model + simiaosan; iv) model + NALP3­overexpressing adenovirus + simiaosan; and v) model + empty vector adenovirus + simiaosan. The samples from mice in each group were subjected to hematoxylin and eosin (H&E) staining for assessing the histopathological changes, enzyme­linked immunosorbent assays for determining IL­1ß and TGF­ß1 levels and western blotting for evaluating NALP3 expression. H&E staining indicated that simiaosan could reduce the infiltration of inflammatory cells, while NALP3 overexpression aggravated the inflammatory response in tissues. Expression levels of IL­1ß, TGF­ß1 and NALP3 were significantly higher in the model and the model + NALP3­overexpressing adenovirus + simiaosan groups compared with the normal control group. Levels of IL­1ß, TGF­ß1 and NALP3 were significantly lower in the model + simiaosan and model + empty vector adenovirus + simiaosan groups compared with the model group. These results indicated that the effects of simiaosan were mediated through NALP3 inhibition. Therefore, the herbal medicine simiaosan was revealed to possess an ability to alleviate the symptoms of GA by regulating the NALP3/IL­1ß signaling pathway.

HBx gene transfection affects the cycle of primary renal tubular epithelial cells through regulating cyclin expression.

Hepatitis B virus X protein (HBx) has been previously demonstrated to be associated with the regulation of cell proliferation; however, the exact mechanisms underlying this effect remain unclear. The present study aimed to investigate the regulatory mechanism of HBx on the cycle progression of primary renal tubular epithelial cells. Primary renal tubular epithelial cells of Sprague Dawley (SD) rats were separated and cultured. The morphology of cultured cells was characterized by immunohistochemical analysis and the results demonstrated that primary renal tubular epithelial cells with the expected morphology and distribution were successfully separated and cultured from SD rats. HBx gene pcDNA3.1/myc vector and empty vector were constructed and transfected into cells as HBx and empty groups, respectively. Following transfection, the mRNA and protein levels of HBx, cyclin A, cyclin D1 and cyclin E in cells were determined by reverse transcription­quantitative polymerase chain reaction and western blot analysis, respectively. The results demonstrated that following HBx gene transfection, the mRNA and protein levels of HBx, cyclin A, cyclin D1 and cyclin E in cells were significantly upregulated, compared with the empty control group (P<0.05). Furthermore, cell apoptosis and the cell cycle were evaluated by Annexin V­fluorescein isothiocyanate/propidium iodide staining and flow cytometry. HBx gene transfection significantly inhibited the cell apoptosis (P<0.05), promoted cell cycle progression from the G1 to S phase and arrested the cell cycle in the S phase. Therefore, the results of the present study indicated that HBx gene transfection may regulate the apoptosis and cell cycle of primary renal tubular epithelial cells by affecting the expression of cyclins. The results of the present study may improve the understanding of pathogenesis associated with HBV­associated glomerulonephritis, and may also provide insight and theoretical support for the future design and development of drugs for the treatment of hepatitis B virus.