scholarly journals Fibulin-2 deficiency attenuates angiotensin II-induced cardiac hypertrophy by reducing transforming growth factor-β signalling

2013 ◽  
Vol 126 (4) ◽  
pp. 275-288 ◽  
Author(s):  
Hangxiang Zhang ◽  
Jing Wu ◽  
Hailong Dong ◽  
Shaukat A. Khan ◽  
Mon-Li Chu ◽  
...  

AngII (angiotensin II) is a potent neurohormone responsible for cardiac hypertrophy, in which TGF (transforming growth factor)-β serves as a principal downstream mediator. We recently found that ablation of fibulin-2 in mice attenuated TGF-β signalling, protected mice against progressive ventricular dysfunction, and significantly reduced the mortality after experimental MI (myocardial infarction). In the present study, we investigated the role of fibulin-2 in AngII-induced TGF-β signalling and subsequent cardiac hypertrophy. We performed chronic subcutaneous infusion of AngII in fibulin-2 null (Fbln2−/−), heterozygous (Fbln2+/−) and WT (wild-type) mice by a mini-osmotic pump. After 4 weeks of subpressor dosage of AngII infusion (0.2 μg/kg of body weight per min), WT mice developed significant hypertrophy, whereas the Fbln2−/− showed no response. In WT, AngII treatment significantly up-regulated mRNAs for fibulin-2, ANP (atrial natriuretic peptide), TGF-β1, Col I (collagen type I), Col III (collagen type III), MMP (matrix metalloproteinase)-2 and MMP-9, and increased the phosphorylation of TGF-β-downstream signalling markers, Smad2, TAK1 (TGF-β-activated kinase 1) and p38 MAPK (mitogen-activated protein kinase), which were all unchanged in AngII-treated Fbln2−/− mice. The Fbln2+/− mice consistently displayed AngII-induced effects intermediate between WT and Fbln2−/−. Pressor dosage of AngII (2 mg/kg of body weight per min) induced significant fibrosis in WT but not in Fbln2−/− mice with comparable hypertension and hypertrophy in both groups. Isolated CFs (cardiac fibroblasts) were treated with AngII, in which direct AngII effects and TGF-β-mediated autocrine effects was observed in WT. The latter effects were totally abolished in Fbln2−/− cells, suggesting that fibulin-2 is essential for AngII-induced TGF-β activation. In conclusion our data indicate that fibulin-2 is essential for AngII-induced TGF-β-mediated cardiac hypertrophy via enhanced TGF-β activation and suggest that fibulin-2 is a potential therapeutic target to inhibit AngII-induced cardiac remodelling.

2019 ◽  
Vol 316 (6) ◽  
pp. F1162-F1172 ◽  
Author(s):  
Qingqing Wei ◽  
Jennifer Su ◽  
Guie Dong ◽  
Ming Zhang ◽  
Yuqing Huo ◽  
...  

Renal interstitial fibrosis is a common pathological feature of chronic kidney disease that may involve changes of metabolism in kidney cells. In the present study, we first showed that blockade of glycolysis with either dichloroacetate (DCA) or shikonin to target different glycolytic enzymes reduced renal fibrosis in a mouse model of unilateral ureteral obstruction (UUO). Both inhibitors evidently suppressed the induction of fibronectin and collagen type I in obstructed kidneys, with DCA also showing inhibitory effects on collagen type IV and α-smooth muscle actin (α-SMA). Histological examination also confirmed less collagen deposition in DCA-treated kidneys. Both DCA and shikonin significantly inhibited renal tubular apoptosis but not interstitial apoptosis in UUO. Macrophage infiltration after UUO injury was also suppressed. Shikonin, but not DCA, caused obvious animal weight loss during UUO. To determine whether shikonin and DCA worked on tubular cells and/or fibroblasts, we tested their effects on cultured renal proximal tubular BUMPT cells and renal NRK-49F fibroblasts during hypoxia or transforming growth factor-β1 treatment. Although both inhibitors reduced fibronectin and α-SMA production in NRK-49F cells during hypoxia or transforming growth factor-β1 treatment, they did not suppress fibronectin and α-SMA expression in BUMPT cells. Altogether, these results demonstrate the inhibitory effect of glycolysis inhibitors on renal interstitial fibrosis. In this regard, DCA is more potent for fibrosis inhibition and less toxic to animals than shikonin.


2011 ◽  
Vol 89 (3) ◽  
pp. 197-205 ◽  
Author(s):  
Katarina Mackovicova ◽  
Andrea Gazova ◽  
Dana Kucerova ◽  
Beata Gajdacova ◽  
Jan Klimas ◽  
...  

Angiotensin II can induce cardiac hypertrophy by stimulating the release of growth factors. ACE inhibitors reduce angiotensin II levels and cardiac hypertrophy, but their effects on the healthy heart are largely unexplored. We hypothesized that ACE inhibition decreases left ventricular mass in normotensive animals and that this is associated with altered expression of cardiac fetal genes, growth factors, and endothelial nitric oxide synthase (eNOS). Wistar rats (n = 7 per group) were orally administered with enalapril twice daily for a total daily dose of 5 mg·kg–1·d–1 (ENAP5) or 15 mg·kg–1·d–1 (ENAP15) or vehicle. Systolic blood pressure was measured by the tail-cuff method. Left ventricular expression of cardiac myosin heavy chain-α (MYH6) and -β (MYH7), atrial natriuretic peptide (ANP), endothelin-1 (ET-1), transforming growth factor β-1 (TGFβ-1), cardiotrophin-1 (CT-1), and renal renin were examined by real-time PCR, and eNOS using Western blot. Blood pressure was decreased only in ENAP15 animals (p < 0.05 vs. Control), whereas left ventricular mass decreased after both doses of enalapril (p < 0.05 vs. Control). MYH7 and ANP were reduced in ENAP15, while no changes in ET-1, TGFβ-1, CT-1, and MYH6 mRNA or eNOS protein were observed. Renal renin dose-dependently increased after enalapril treatment. Enalapril significantly decreased left ventricular mass even after 1 week treatment in the normotensive rat. This was associated with a decreased expression of the fetal genes MYH7 and ANP, but not expression of ET-1, CT-1, or TGFβ-1.


2021 ◽  
Vol 10 (4) ◽  
Author(s):  
Jing Zhao ◽  
Xiaoli Jiang ◽  
Jinhua Liu ◽  
Ping Ye ◽  
Lang Jiang ◽  
...  

Background Heart pathological hypertrophy has been recognized as a predisposing risk factor for heart failure and arrhythmia. DUSP (dual‐specificity phosphatase) 26 is a member of the DUSP family of proteins, which has a significant effect on nonalcoholic fatty liver disease, neuroblastoma, glioma, and so on. However, the involvement of DUSP26 in cardiac hypertrophy remains unclear. Methods and Results Our study showed that DUSP26 expression was significantly increased in mouse hearts in response to pressure overload as well as in angiotensin II–treated cardiomyocytes. Cardiac‐specific overexpression of DUSP26 mice showed attenuated cardiac hypertrophy and fibrosis, while deficiency of DUSP26 in mouse hearts resulted in increased cardiac hypertrophy and deteriorated cardiac function. Similar effects were also observed in cellular hypertrophy induced by angiotensin II. Importantly, we showed that DUSP26 bound to transforming growth factor‐β activated kinase 1 and inhibited transforming growth factor‐β activated kinase 1 phosphorylation, which led to suppression of the mitogen‐activated protein kinase signaling pathway. In addition, transforming growth factor‐β activated kinase 1–specific inhibitor inhibited cardiomyocyte hypertrophy induced by angiotensin II and attenuated the exaggerated hypertrophic response in DUSP26 conditional knockout mice. Conclusions Taken together, DUSP26 was induced in cardiac hypertrophy and protected against pressure overload induced cardiac hypertrophy by modulating transforming growth factor‐β activated kinase 1–p38/ c‐Jun N‐terminal kinase–signaling axis. Therefore, DUSP26 may provide a therapeutic target for treatment of cardiac hypertrophy and heart failure.


2020 ◽  
Vol 128 (4) ◽  
pp. 1033-1043
Author(s):  
Yi-Yuan Lin ◽  
Yi Hong ◽  
Ming-Cheng Zhou ◽  
Hai-Liang Huang ◽  
Woei-Cherng Shyu ◽  
...  

This study investigated the effects of exercise training on cardiac inflammatory and cardiac fibrotic pathways in female spontaneously hypertensive rats (SHR), which were divided into a sham-operated sedentary hypertensive group (SHR-S), a sedentary hypertensive ovariectomized group (SHR-O), or a hypertensive ovariectomized group with treadmill exercise training (SHR-OT; 60 min/day, 5 days/wk) for 8 wk. Normotensive female Wistar-Kyoto rats (WKY) served as controls. SOD and catalase (CAT) activities were significantly increased in the SHR-OT group, when compared with the SHR-S or SHR-O groups. The protein levels of estrogen receptor (ER)-α and ER-β became decreased in the SHR-O group, when compared with the WKY or SHR-S groups, but were not changed in the SHR-OT group. The protein level of the angiotensin II type I receptor (AT1R) was increased in the SHR-S group but did not further change in the SHR-O group, whereas it was decreased in the SHR-OT group. The inflammatory-related protein levels of TNF-α, p-NF-κB, cyclooxygenase 2 (COX-2), inducible nitric oxide synthase (iNOS), and IL-6, as well as the fibrotic-related protein levels of transforming growth factor-β (TGF-β), p-Smad2/3, connective tissue growth factor (CTGF), tissue-type plasminogen activator (tPA), matrix metalloproteinase (MMP)-9, and collagen I were increased in the SHR-S group and increased further in the SHR-O group, whereas they were decreased in the SHR-OT group. The coexistence of hypertension and ovariectomy additively increased cardiac inflammatory and fibrotic pathways partially through hypertension-enhanced AT1R and ovariectomy-depressed estrogen receptors. Exercise training appeared to suppress hypertensive ovariectomized heart-induced inflammatory and fibrotic pathways possibly through decreasing AT1R but not through estrogen receptors. NEW & NOTEWORTHY The coexistence of hypertension and ovariectomy appeared to increase cardiac inflammatory and fibrotic pathways likely through hypertension-enhanced angiotensin II type I receptor and ovariectomy-depressed estrogen receptors. Exercise training on a treadmill could prevent hypertensive ovariectomized heart-induced cardiac inflammation and fibrosis via an inflammatory pathway [TNF-α, p-IKK-α/β, p-NF-κB, cyclooxygenase 2 (COX-2), iNOS, and IL-6] and fibrotic pathway [transforming growth factor-β (TGF-β), p-Smad2/3, connective tissue growth factor (CTGF), tissue-type plasminogen activator (tPA), matrix metalloproteinase (MMP)-9, and collagen I] possibly through decreasing angiotensin II type I receptor but not through estrogen receptors.


2012 ◽  
Vol 124 (3) ◽  
pp. 191-202 ◽  
Author(s):  
Mona Sedeek ◽  
Alex Gutsol ◽  
Augusto C. Montezano ◽  
Dylan Burger ◽  
Aurelie Nguyen Dinh Cat ◽  
...  

Nox (NADPH oxidase)-derived ROS (reactive oxygen species) have been implicated in the development of diabetic nephropathy. Of the Nox isoforms in the kidney, Nox4 is important because of its renal abundance. In the present study, we tested the hypothesis that GKT136901, a Nox1/4 inhibitor, prevents the development of nephropathy in db/db (diabetic) mice. Six groups of male mice (8-week-old) were studied: (i) untreated control db/m, (ii) low-dose GKT136901-treated db/m (30 mg/kg of body weight per day), (iii) high-dose GKT136901-treated db/m (90 mg/kg of body weight per day), (iv) untreated db/db; (v) low dose GKT136901-treated db/db; and (vi) high-dose GKT136901-treated db/db. GKT136901, in chow, was administered for 16 weeks. db/db mice developed diabetes and nephropathy as evidenced by hyperglycaemia, albuminuria and renal injury (mesangial expansion, tubular dystrophy and glomerulosclerosis). GKT136901 treatment had no effect on plasma glucose or BP (blood pressure) in any of the groups. Plasma and urine TBARSs (thiobarbituric acid-reacting substances) levels, markers of systemic and renal oxidative stress, respectively, were increased in diabetic mice. Renal mRNA expression of Nox4, but not of Nox2, increased, Nox1 was barely detectable in db/db. Expression of the antioxidant enzyme SOD-1 (superoxide dismutase 1) decreased in db/db mice. Renal content of fibronectin, pro-collagen, TGFβ (transforming growth factor β) and VCAM-1 (vascular cell adhesion molecule 1) and phosphorylation of ERK1/2 (extracellular-signal-regulated kinase 1/2) were augmented in db/db kidneys, with no change in p38 MAPK (mitogen-activated protein kinase) and JNK (c-Jun N-terminal kinase). Treatment reduced albuminuria, TBARS and renal ERK1/2 phosphorylation and preserved renal structure in diabetic mice. Our findings suggest a renoprotective effect of the Nox1/4 inhibitor, possibly through reduced oxidative damage and decreased ERK1/2 activation. These phenomena occur independently of improved glucose control, suggesting GKT136901-sensitive targets are involved in complications of diabetes rather than in the disease process.


2009 ◽  
Vol 20 (3) ◽  
pp. 1020-1029 ◽  
Author(s):  
Wei Zuo ◽  
Ye-Guang Chen

Transforming growth factor (TGF)-β regulates a spectrum of cellular events, including cell proliferation, differentiation, and migration. In addition to the canonical Smad pathway, TGF-β can also activate mitogen-activated protein kinase (MAPK), phosphatidylinositol 3-kinase (PI3K)/Akt, and small GTPases in a cell-specific manner. Here, we report that cholesterol depletion interfered with TGF-β–induced epithelial-mesenchymal transition (EMT) and cell migration. This interference is due to impaired activation of MAPK mediated by cholesterol-rich lipid rafts. Cholesterol-depleting agents specifically inhibited TGF-β–induced activation of extracellular signal-regulated kinase (ERK) and p38, but not Smad2/3 or Akt. Activation of ERK or p38 is required for both TGF-β–induced EMT and cell migration, whereas PI3K/Akt is necessary only for TGF-β–promoted cell migration but not for EMT. Although receptor heterocomplexes could be formed in both lipid raft and nonraft membrane compartments in response to TGF-β, receptor localization in lipid rafts, but not in clathrin-coated pits, is important for TGF-β–induced MAPK activation. Requirement of lipid rafts for MAPK activation was further confirmed by specific targeting of the intracellular domain of TGF-β type I receptor to different membrane locations. Together, our findings establish a novel link between cholesterol and EMT and cell migration, that is, cholesterol-rich lipid rafts are required for TGF-β–mediated MAPK activation, an event necessary for TGF-β–directed epithelial plasticity.


1998 ◽  
Vol 273 (16) ◽  
pp. 9365-9368 ◽  
Author(s):  
Min-Ji Charng ◽  
Dou Zhang ◽  
Paı̈vi Kinnunen ◽  
Michael D. Schneider

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