Rhein attenuates renal inflammatory injury of uric acid nephropathy via lincRNA-Cox2/miR-150-5p/STAT1 axis.

Rhein has protective effect on uric acid nephropathy (UAN). This article aims to demystify the mechanism of function of rhein in UAN. Mouse kidney epithelial cell line (TCMK-1) was incubated with uric acid (UA) to induce inflammatory injury. Then, the TCMK-1 cells were treated with rhein. The relationships among lincRNA-Cox2, miR-150-5p and STAT1 were evaluated by luciferase reporter assay. CCK8 and flow cytometry were performed to detect cell proliferation and apoptosis. The levels of IL-6, IL-1ß and TNF-α were investigated by enzyme linked immunosorbent assay. Western blot and quantitative real-time PCR were performed to examine the expression of genes and proteins. We found that UA suppressed proliferation and enhanced apoptosis and the levels of IL-6, IL-1ß and TNF-α of TCMK-1 cells, which was effectively improved by rhein treatment. Furthermore, lincRNA-Cox2 overexpression caused an increase of apoptosis and inflammatory factors in the rhein-treated TCMK-1 cells. LincRNA-Cox2 regulated STAT1 expression by sponging miR-150-5p. And lincRNA-Cox2 promoted apoptosis and inflammatory injury of TCMK-1 cells by regulating miR-150-5p/STAT1 axis. In summary, our studies demonstrate that rhein has a protective effect against UAN by inhibiting renal inflammatory injury via lincRNA-Cox2/miR-150-5p/STAT1 axis.

Long non-coding RNA ANRIL-mediated inflammation response is involved in protective effect of rhein in uric acid nephropathy rats.

BACKGROUND: The aim of this study was to investigate the role of long non-coding RNAs (LncRNAs) antisense non-coding RNA in the INK4 locus (ANRIL) in anti-inflammation of rhein in uric acid nephropathy (UAN) rats. METHODS: Rat models of UAN were induced by adenine and potassium oxonate. Enzyme-linked immunosorbent assay (ELISA) was performed to assess inflammation factor in serum and supernatant. ANRIL mRNA level was detected using real-time reverse transcription PCR (qRT-PCR). Immunostaining was used to observe pathological changes of renal tissues in rats. RESULTS: ANRIL and inflammatory factor levels were highly expressed in patient with UAN. Furthermore, rhein showed an observable effect on anti-inflammatory and renal protection in UAN rats, rhein inhibited expressions of ANRIL in vivo or in vitro. Besides, ANRIL-mediated inflammatory response attenuated protective effect of rhein. CONCLUSIONS: ANRIL-mediated inflammatory response attenuated the protective effect of rhein in UAN rats. This study showed an understanding of the role and mechanism of ANRIL in UAN, which provides a new target and therapy for the prevention and treatment of UAN.

LncRNA ANRIL promotes NLRP3 inflammasome activation in uric acid nephropathy through miR-122-5p/BRCC3 axis.

This study is designed to explore the mechanism by which long non-coding RNA (lncRNA) antisense non-coding RNA in the INK4 locus (ANRIL) plays a pathogenic role in uric acid nephropathy (UAN). The expressions of ANRIL, miR-122-5p, BRCA1-BRCA2-containing complex subunit 3 (BRCC3) and NOD-like receptor protein 3 (NLRP3) were determined in UAN patients and uric acid-treated HK-2 cells by qRT-PCR. Protein levels of BRCC3 and NLRP3 were examined by western blot. The levels of inflammatory cytokines were quantified by ELISA. CCK-8 assay was used to assess cell viability. Apoptosis was detected by Annexin V-FITC/PI double-labeled flow cytometry and TUNEL assay. The interaction between ANRIL, miR-122-5p and BRCC3 were studied using luciferase reporter assay. The role of ANRIL in renal injury was evaluated in experimental rats. ANRIL and BRCC3 were highly expressed while miR-122-5p was down-regulated in serum of UAN patients and uric acid-treated tubular epithelial cells. Luciferase reporter assay and in vitro rescue experiment confirmed that ANRIL promoted NLRP3 inflammasome activation by up-regulating BRCC3 expression via sponging miR-122-5p. Furthermore, in vivo experiment validated that knockdown of ANRIL alleviated renal injury of UAN rats. ANRIL exerted pathogenic effect in UAN to promote NLRP3 inflammasome activation via miR-122-5p/BRCC3 axis.

Weicao capsule ameliorates renal injury through increasing autophagy and NLRP3 degradation in UAN rats.

Uric acid nephropathy (UAN) is one of the most common metabolic diseases and leads to kidney damage. This study aimed to evaluate the effect of Weicao capsule on renal injury of UAN rats and to examine whether the mechanism was associated with induction of autophagy and degradation of nucleotide binding oligomerization domain (Nod)-like receptor (NLR) protein 3 (NLRP3) inflammasome. Sixty Sprague-Dawley rats were randomly allocated into 6 groups: Control, Model, Allopurinol, and Weicao (0.55/1.1/2.2 g/kg) group. The data showed activation of renal NLRP3 inflammasome in UAN rats, with elevation in serum levels of interleukin (IL)-1ß and IL-18, and subsequent deterioration of renal injury. Fortunately, Weicao had a markedly therapeutic effect on UAN rats, including improving renal function-related indexes, ameliorating hyperuricemia-related inflammation, decreasing crystals in renal tissue and alleviating renal interstitial fibrosis. Additionally, Weicao exerted anti-proliferative and anti-apoptosis effects on rat renal tubular epithelial cell NRK-52E in macrophages from UAN rats. Our investigation into the mechanism revealed that Weicao suppressed the activated NLRP3 inflammasome. Furthermore, Weicao induced autophagy, as evidenced by a dose-dependent increase in levels of renal autophagy-related proteins in UAN rats. Moreover, autophagy inhibitor 3-MA and NLRP3 activator ATP blocked the effect of Weicao on autophagy induction and NLRP3 inflammasome degradation. In conclusion, Weicao had similar effects as allopurinol and exerted anti-inflammatory and renal-protective effect in a concentration-dependent manner in UAN rats, most likely through increasing autophagy and NLRP3 degradation. Our study provides new insight into the underlying mechanism of Weicao in the treatment of UAN.

Antiplatelet activity of loureirin A by attenuating Akt phosphorylation: In vitro studies.

Loureirin A is a flavonoid extracted from Dragon׳s Blood that has been used to promote blood circulation and remove stasis in Chinese traditional medicine. However, the mechanisms of these effects are not fully understood. We explored the anti-platelet activity and underlying mechanism of loureirin A in vitro. Our results indicated that loureirin A negatively affected agonist-induced platelet aggregation such as collagen, collagen-related peptide (CRP), ADP and thrombin. Loureirin A inhibited collagen-induced platelet ATP secretion and thrombin-stimulated P-selectin expression in a dose-dependent manner. Platelet spreading on immobilized fibrinogen was significantly impaired in the presence of loureirin A. Immunoblotting analysis indicated that 100µM of loureirin A almost completely eliminated collagen-induced Akt phosphorylation at Ser473. Interestingly, a submaximal dose (50µM) of loureirin A had an additive inhibitory effect with the phosphoinositide 3-kinase (PI3K) inhibitor Ly294002 on collage-induced Akt phosphorylation in platelets. Taken together, loureirin A had an inhibitory effect on platelet activation, perhaps through an impairment of PI3K/Akt signaling.