Overexpression of angiotensin type 2 receptor ameliorates glomerular injury in a mouse remnant kidney model

2004 ◽  
Vol 286 (3) ◽  
pp. F516-F525 ◽  
Author(s):  
Naoko Hashimoto ◽  
Yohei Maeshima ◽  
Minoru Satoh ◽  
Masahiro Odawara ◽  
Hitoshi Sugiyama ◽  
...  

Angiotensin II mediates the progression of renal disease through the type 1 receptor (AT1R). Recent studies have suggested that type 2 receptor (AT2R)-mediated signaling inhibits cell proliferation by counteracting the actions of AT1R. The aim of the present study was to determine the effect of AT2R overexpression on glomerular injury induced by ⅚ nephrectomy (⅚Nx). AT2R transgenic mice (AT2-Tg), overexpressing AT2R under the control of α-smooth muscle actin (α-SMA) promoter, and control wild-type mice (Wild) were subjected to ⅚Nx. In AT2-Tg mice, the glomerular expression of AT2R was upregulated after ⅚Nx. Urinary albumin excretion at 12 wk after ⅚Nx was decreased by 33.7% in AT2-Tg compared with Wild mice. Glomerular size in AT2-Tg mice was significantly smaller than in Wild mice after ⅚Nx (93.1 ± 3.0 vs. 103.3 ± 1.8 μm; P < 0.05). Immunohistochemistry revealed significant decreases in glomerular expression of platelet-derived growth factor-BB chain (PDGF-BB) and transforming growth factor-β1 (TGF-β1) in AT2-Tg with ⅚Nx compared with Wild mice. Urinary excretion of nitric oxide metabolites was increased 2.5-fold in AT2-Tg compared with Wild mice. EMSA showed that activation of early growth response gene-1, which induces the transcription of PDGF-BB and TGF-β1, was decreased in AT2-Tg mice. These changes in AT2-Tg mice at 12 wk after ⅚Nx were blocked by the AT2R antagonist PD-123319. Taken together, our findings suggest that AT2R-mediated signaling may protect from glomerular injuries induced by ⅚Nx and that overexpression of AT2R may serve as a potential therapeutic strategy for glomerular disorders.

2000 ◽  
Vol 57 (6) ◽  
pp. 2434-2444 ◽  
Author(s):  
Heather M. Wilson ◽  
Andrew W.M. Minto ◽  
Paul A.J. Brown ◽  
Lars-Peter Erwig ◽  
Andrew J. Rees

Autophagy ◽  
2012 ◽  
Vol 8 (12) ◽  
pp. 1782-1797 ◽  
Author(s):  
Seung-Il Choi ◽  
Bong-Yoon Kim ◽  
Shorafidinkhuja Dadakhujaev ◽  
Jun-Young Oh ◽  
Tae-Im Kim ◽  
...  

Cells ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 456 ◽  
Author(s):  
Ute A. Schwinghammer ◽  
Magda M. Melkonyan ◽  
Lilit Hunanyan ◽  
Roman Tremmel ◽  
Ralf Weiskirchen ◽  
...  

The noradrenergic system is proposed to play a prominent role in the pathogenesis of liver fibrosis. While α1- and β-adrenergic receptors (ARs) are suggested to be involved in a multitude of profibrogenic actions, little is known about α2-AR-mediated effects and their expression pattern during liver fibrosis and cirrhosis. We explored the expression of α2-AR in two models of experimental liver fibrosis. We further evaluated the capacity of the α2-AR blocker mesedin to deactivate hepatic stellate cells (HSCs) and to increase the permeability of human liver sinusoidal endothelial cells (hLSECs). The mRNA of α2a-, α2b-, and α2c-AR subtypes was uniformly upregulated in carbon tetrachloride-treated mice vs the controls, while in bile duct-ligated mice, only α2b-AR increased in response to liver injury. In murine HSCs, mesedin led to a decrease in α-smooth muscle actin, transforming growth factor-β and α2a-AR expression, which was indicated by RT-qPCR, immunocytochemistry, and Western blot analyses. In a hLSEC line, an increased expression of endothelial nitric oxide synthase was detected along with downregulated transforming growth factor-β. In conclusion, we suggest that the α2-AR blockade alleviates the activation of HSCs and may increase the permeability of liver sinusoids during liver injury.


2020 ◽  
Vol 15 (11) ◽  
pp. 1934578X2097150
Author(s):  
Yung-Jia Chiu ◽  
Kun-Chang Wu ◽  
Jen-Chieh Tsai ◽  
Chun-Pin Kao ◽  
Jung Chao ◽  
...  

The aim of this study was to evaluate the hepatoprotective effects of the fruits of Polygonum orientale L. (POE) against fibrosis in carbon tetrachloride (CCl4)-induced liver injury. Bioactive components of POE were identified using liquid chromatography (LC)-mass spectrometry (MS)/MS by comparison with standards. Treatment with either silymarin (200 mg/kg) or POE (0.5 and 1.0 g/kg) caused significant decreases in the serum levels of enzymes and reduced the extent of liver lesions and fibrosis in histological analysis. POE (0.5 and 1.0 g/kg) decreased the levels of malondialdehyde, nitric oxide, proinflammatory cytokines (ie, tumor necrosis factor-α, interleukin [IL]-1β, and IL-6), an inflammatory cytokine (ie, cyclooxygenase-2), a profibrotic cytokine (ie, transforming growth factor-β), and fibrosis-related proteins (ie, connective tissue growth factor and α-smooth muscle actin) in the liver and enhanced the activities of the antioxidative enzymes superoxide dismutase, glutathione peroxidase, glutathione reductase, and catalase. Quantitative analysis of the active constituents in POE revealed an extract composition of 3.4 mg/g of protocatechuic acid, 20.8 mg/g of taxifolin, and 5.6 mg/g of quercetin. We have demonstrated that the hepatoprotective mechanisms of POE are likely to be associated with the decrease in inflammatory cytokines by increasing the activities of antioxidant enzymes. Our findings provide evidence that POE possesses a hepatoprotective activity to ameliorate chronic liver injury.


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