scholarly journals Ghrelin Ameliorates Angiotensin II-Induced Myocardial Fibrosis by Upregulating Peroxisome Proliferator-Activated Receptor Gamma in Young Male Rats

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Qian Wang ◽  
Xin Sui ◽  
Rui Chen ◽  
Pei-Yong Ma ◽  
Yong-Liang Teng ◽  
...  

Angiotensin (Ang) II contributes to the formation and development of myocardial fibrosis. Ghrelin, a gut peptide, has demonstrated beneficial effects against cardiovascular disease. In the present study, we explored the effect and related mechanism of Ghrelin on myocardial fibrosis in Ang II-infused rats. Adult Sprague-Dawley (SD) rats were divided into 6 groups: Control, Ang II (200ng/kg/min, microinfusion), Ang II+Ghrelin (100μg/kg, subcutaneously twice daily), Ang II+Ghrelin+GW9662 (a specific PPAR-γinhibitor, 1 mg/kg/d, orally), Ang II+GW9662, and Ghrelin for 4 wks. In vitro, adult rat cardiac fibroblasts (CFs) were pretreated with or without Ghrelin, Ghrelin+GW9662, or anti-Transforming growth factor (TGF)-β1 antibody and then stimulated with or without Ang II (100 nmol/L) for 24 h. Ang II infusion significantly increased myocardial fibrosis, expression of collagen I, collagen III, and TGF-β1, as well as TGF-β1 downstream proteins p-Smad2, p-Smad3, TRAF6, and p-TAK1 (all p<0.05). Ghrelin attenuated these effects. Similar results were seen in Ang II-stimulated rat cardiac fibroblasts in vitro. In addition, Ghrelin upregulated PPAR-γexpressionin vivoandin vitro, and treatment with GW9662 counteracted the effects of Ghrelin. In conclusion, Ghrelin ameliorated Ang II-induced myocardial fibrosis by upregulating PPAR-γand in turn inhibiting TGF-β1signaling.

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Lulu Liu ◽  
Weiwei Gong ◽  
Shuping Zhang ◽  
Jieru Shen ◽  
Yuqin Wang ◽  
...  

Sirtuin 3 (SIRT3) is critical in mitochondrial function and oxidative stress. Our present study investigates whether hydrogen sulfide (H2S) attenuated myocardial fibrosis and explores the possible role of SIRT3 on the protective effects. Neonatal rat cardiac fibroblasts were pretreated with NaHS followed by angiotensin II (Ang II) stimulation. SIRT3 was knocked down with siRNA technology. SIRT3 promoter activity and expression, as well as mitochondrial function, were measured. Male wild-type (WT) and SIRT3 knockout (KO) mice were intraperitoneally injected with NaHS followed by transverse aortic constriction (TAC). Myocardium sections were stained with Sirius red. Hydroxyproline content, collagen I and collagen III, α-smooth muscle actin (α-SMA), and dynamin-related protein 1 (DRP1) expression were measured both in vitro and in vivo. We found that NaHS enhanced SIRT3 promoter activity and increased SIRT3 mRNA expression. NaHS inhibited cell proliferation and hydroxyproline secretion, decreased collagen I, collagen III, α-SMA, and DRP1 expression, alleviated oxidative stress, and improved mitochondrial respiration function and membrane potential in Ang II-stimulated cardiac fibroblasts, which were unavailable after SIRT3 was silenced. In vivo, NaHS reduced hydroxyproline content, ameliorated perivascular and interstitial collagen deposition, and inhibited collagen I, collagen III, and DRP1 expression in the myocardium of WT mice but not SIRT3 KO mice with TAC. Altogether, NaHS attenuated myocardial fibrosis through oxidative stress inhibition via a SIRT3-dependent manner.


2013 ◽  
Vol 304 (6) ◽  
pp. F801-F807 ◽  
Author(s):  
Zhengrong Guan ◽  
Matthew I. Giddens ◽  
David A. Osmond ◽  
Anthony K. Cook ◽  
Janet L. Hobbs ◽  
...  

Autoregulation is critical for protecting the kidney against arterial pressure elevation and is compromised in some forms of hypertension. Evidence indicates that activated lymphocytes contribute importantly to cardiovascular injury in hypertension. We hypothesized that activated lymphocytes contribute to renal vascular dysfunction by impairing autoregulation and P2X1 receptor signaling in ANG II-infused hypertensive rats. Male Sprague-Dawley rats receiving ANG II infusion were treated with a lymphocyte proliferation inhibitor, mycophenolate mofetil (MMF) for 2 wk. Autoregulation was assessed in vitro and in vivo using the blood-perfused juxtamedullary nephron preparation and anesthetized rats, respectively. ANG II-treated rats exhibited impaired autoregulation. At the single vessel level, pressure-mediated afferent arteriolar vasoconstriction was significantly blunted ( P < 0.05 vs. control rats). At the whole kidney level, renal blood flow passively decreased as renal perfusion pressure was reduced. MMF treatment did not alter the ANG II-induced hypertensive state; however, MMF did preserve autoregulation. The autoregulatory profiles in both in vitro or in vivo settings were similar to the responses from control rats despite persistent hypertension. Autoregulatory responses are linked to P2X1 receptor activation. Accordingly, afferent arteriolar responses to ATP and the P2X1 receptor agonist β,γ-methylene ATP were assessed. ATP- or β,γ-methylene ATP-induced vasoconstriction was significantly attenuated in ANG II-infused hypertensive rats but was normalized by MMF treatment. Moreover, MMF prevented elevation of plasma transforming growth factor-β1 concentration and lymphocyte and macrophage infiltration in ANG II-infused kidneys. These results suggest that anti-inflammatory treatment with MMF prevents lymphocyte infiltration and preserves autoregulation in ANG II-infused hypertensive rats, likely by normalizing P2X1 receptor activation.


2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Qian Wang ◽  
Xin Sui ◽  
Dian-Jun Sui ◽  
Ping Yang

The flavonoid extract from propolis (FP) has been shown to protect against heart injury induced by isoproterenol. However, the effect of FP on cardiac fibrosis after myocardial infarction (MI) as well as the underlying mechanisms is not known. In the present study, we used biochemical and histological approaches to examine the effects of FP on MI-induced cardiac fibrosis and the related mechanisms in a rat MI model and in angiotensin II- (Ang II-) treated rat cardiac fibroblasts (CFs). In vivo, MI was generated by ligation of the left anterior descending coronary artery of rats, which remained for 4 weeks. Rats were randomly divided into the sham, MI, FP (12.5 mg/kg/d), and MI+FP groups. We found that FP treatment improved heart function, reduced cardiac fibrosis, and downregulated the expression of fibrosis-related factors including collagen I, collagen III, matrix metalloproteinase-2 (MMP-2), MMP-9, transforming growth factor-β1 (TGF-β1), and p-Smad2/3, which coincided with the upregulated expression of silent information regulator 1 (SIRT1) in the hearts of MI rats. Our in vitro experiments showed that FP inhibited the proliferation and migration of primary cultured rat CFs and downregulated the expression of the above-mentioned fibrosis-related factors in Ang II-stimulated CFs. In addition, FP can decrease ROS production induced by MI and Ang II in vivo and vitro. Notably, silencing SIRT1 counteracted the FP-induced effects on CFs treated with Ang II. We conclude that FP inhibits MI-induced cardiac fibrosis through SIRT1 activation and that FP represents a potential promising drug for the treatment of MI patients in the clinic.


2005 ◽  
Vol 289 (3) ◽  
pp. H982-H991 ◽  
Author(s):  
Fatiha Bouzeghrane ◽  
Dieter P. Reinhardt ◽  
Tim L. Reudelhuber ◽  
Gaétan Thibault

Fibrillin-1 localization in the myocardium and the modulation of its expression in cardiac fibrosis were examined. In normal rat hearts, fibrillin-1 was abundant throughout the myocardium as thin fibers that crossed over the perimysium and around arteries. After cardiac fibrosis was induced in rats by either 14-day ANG II infusion or 21-day DOCA-salt treatment [a high endothelin-1 (ET-1) model], fibrillin-1 immunostaining was stronger in the interstitium (2.8-fold and 4.4-fold increases, respectively, in each model), extended between myocytes, and accumulated in microscopic scars and in the perivascular area of both ventricles. mRNA analysis confirmed its enhanced ventricular expression in both groups of rats (2.5-fold and 6.6-fold increments, respectively, in each model). In 1B normotensive and 2C hypertensive transgenic mice, two lines expressing an ANG II fusion protein in cardiac myocytes, strong fibrillin-1 immunoreactivity was observed in the interstitium and around arteries (3.7-fold and 7-fold increases, respectively). ANG II and transforming growth factor-β1 enhanced fibrillin-1 synthesis by cardiac fibroblasts. Some fibrillin-1 fragments interacted with RGD-dependent integrins, including α8β1-integrin, of cardiac fibroblasts but not necessarily through the RGD motif. Our findings illustrate that fibrillin-1 is an important constituent of the myocardium. In vitro and in vivo evidence suggests that ANG II can directly induce fibrillin-1 expression in cardiac fibroblasts. This protein can thus contribute to reactive and reparative processes.


2020 ◽  
Vol 134 (6) ◽  
pp. 609-628 ◽  
Author(s):  
Dajun Chai ◽  
Xiaoyan Lin ◽  
Qiaowen Zheng ◽  
Changsheng Xu ◽  
Hong Xie ◽  
...  

Abstract Diabetic cardiac fibrosis increases ventricular stiffness and facilitates the occurrence of diastolic dysfunction. Retinoid X receptor (RXR) plays an important role in cardiac development and has been implicated in cardiovascular diseases. In the present study, we investigated the effects of RXR agonist treatment on streptozotocin (STZ)-induced diabetic cardiomyopathy (DCM) and the underlying mechanism. Sprague–Dawley (SD) rats induced by STZ injection were treated with either RXR agonist bexarotene (Bex) or vehicle alone. Echocardiography was performed to determine cardiac structure and function. Cardiac fibroblasts (CFs) were treated with high glucose (HG) with or without the indicated concentration of Bex or the RXR ligand 9-cis-retinoic acid (9-cis-RA). The protein abundance levels were measured along with collagen, body weight (BW), blood biochemical indexes and transforming growth factor-β (TGF-β) levels. The effects of RXRα down-regulation by RXRα small interfering RNA (siRNA) were examined. The results showed that bexarotene treatment resulted in amelioration of left ventricular dysfunction by inhibiting cardiomyocyte apoptosis and myocardial fibrosis. Immunoblot with heart tissue homogenates from diabetic rats revealed that bexarotene activated liver kinase B1 (LKB1) signaling and inhibited p70 ribosomal protein S6 kinase (p70S6K). The increased collagen levels in the heart tissues of DCM rats were reduced by bexarotene treatment. Treatment of CFs with HG resulted in significantly reduced LKB1 activity and increased p70S6K activity. RXRα mediated the antagonism of 9-cis-RA on HG-induced LKB1/p70S6K activation changes in vitro. Our findings suggest that RXR agonist ameliorates STZ-induced DCM by inhibiting myocardial fibrosis via modulation of the LKB1/p70S6K signaling pathway. RXR agonists may serve as novel therapeutic agents for the treatment of DCM.


2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Zeping Qiu ◽  
Jingwen Zhao ◽  
Fanyi Huang ◽  
Luhan Bao ◽  
Yanjia Chen ◽  
...  

AbstractMyocardial fibrosis and ventricular remodeling were the key pathology factors causing undesirable consequence after myocardial infarction. However, an efficient therapeutic method remains unclear, partly due to difficulty in continuously preventing neurohormonal overactivation and potential disadvantages of cell therapy for clinical practice. In this study, a rhACE2-electrospun fibrous patch with sustained releasing of rhACE2 to shape an induction transformation niche in situ was introduced, through micro-sol electrospinning technologies. A durable releasing pattern of rhACE2 encapsulated in hyaluronic acid (HA)—poly(L-lactic acid) (PLLA) core-shell structure was observed. By multiple in vitro studies, the rhACE2 patch demonstrated effectiveness in reducing cardiomyocytes apoptosis under hypoxia stress and inhibiting cardiac fibroblasts proliferation, which gave evidence for its in vivo efficacy. For striking mice myocardial infarction experiments, a successful prevention of adverse ventricular remodeling has been demonstrated, reflecting by improved ejection fraction, normal ventricle structure and less fibrosis. The rhACE2 patch niche showed clear superiority in long term function and structure preservation after ischemia compared with intramyocardial injection. Thus, the micro-sol electrospun rhACE2 fibrous patch niche was proved to be efficient, cost-effective and easy-to-use in preventing ventricular adverse remodeling.


2021 ◽  
Vol 30 ◽  
pp. 096368972110354
Author(s):  
Eun-Jung Yoon ◽  
Hye Rim Seong ◽  
Jangbeen Kyung ◽  
Dajeong Kim ◽  
Sangryong Park ◽  
...  

Stamina-enhancing effects of human adipose derived stem cells (hADSCs) were investigated in young Sprague-Dawley rats. Ten-day-old male rats were transplanted intravenously (IV) or intracerebroventricularly (ICV) with hADSCs (1 × 106 cells/rat), and physical activity was measured by locomotor activity and rota-rod performance at post-natal day (PND) 14, 20, 30, and 40, as well as a forced swimming test at PND 41. hADSCs injection increased the moving time in locomotor activity, the latency in rota-rod performance, and the maximum swimming time. For the improvement of physical activity, ICV transplantation was superior to IV injection. In biochemical analyses, ICV transplantation of hADSCs markedly reduced serum creatine phosphokinase, lactate dehydrogenase, alanine transaminase, and muscular lipid peroxidation, the markers for muscular and hepatic injuries, despite the reduction in muscular glycogen and serum triglycerides as energy sources. Notably, hADSCs secreted brain-derived neurotrophic factor (BDNF) and nerve growth factor in vitro, and increased the level of BDNF in the brain and muscles in vivo. The results indicate that hADSCs enhance physical activity including stamina not only by attenuating tissue injury, but also by strengthening the muscles via production of BDNF.


2021 ◽  
Vol 49 (11) ◽  
pp. 030006052110550
Author(s):  
Xing Wang ◽  
Shuchun Chen ◽  
Dan Lv ◽  
Zelin Li ◽  
Luping Ren ◽  
...  

Objective To investigate the effect of liraglutide on the browning of white fat and the suppression of obesity via regulating microRNA (miR)-27b in vivo and in vitro. Methods Sprague-Dawley rats were fed a high-fat (HF) diet and 3T3-L1 pre-adipocytes were differentiated into mature white adipocytes. Rats and mature adipocytes were then treated with different doses of liraglutide. The mRNA and protein levels of browning-associated proteins, including uncoupling protein 1 (UCP1), PR domain containing 16 (PRDM16), CCAAT enhancer binding protein β (CEBPβ), cell death-inducing DFFA-like effector A (CIDEA) and peroxisome proliferator-activated receptor-γ-coactivator 1α (PGC-1α), were detected using quantitative real-time polymerase chain reaction and Western blotting. Results Liraglutide decreased body weight and reduced the levels of blood glucose, triglyceride and low-density lipoprotein cholesterol in HF diet-fed rats. Liraglutide increased the levels of UCP1, PRDM16, CEBPβ, CIDEA and PGC-1α in vivo and vitro. The levels of miR-27b were upregulated in HF diet-fed rats, whereas liraglutide reduced the levels of miR-27b. In vitro, overexpression of miR-27b decreased the mRNA and protein levels of UCP1, PRDM16, CEBPβ, CIDEA and PGC-1α. Transfection with the miR-27b mimics attenuated the effect of liraglutide on the browning of white adipocytes. Conclusion Liraglutide induced browning of white adipose through regulation of miR-27b.


1995 ◽  
Vol 268 (4) ◽  
pp. C910-C917 ◽  
Author(s):  
S. A. Fisher ◽  
M. Absher

Transforming growth factor-beta (TGF-beta) is a ubiquitous growth-regulating protein that is capable of influencing the growth and function of heart cells in vitro. To better understand the role TGF-beta might play as a paracrine mediator of cardiac hypertrophy, the expression, secretion, and growth effects of TGF-beta were examined. Neonatal cardiac fibroblasts in vitro secreted latent TGF-beta 1 and TGF-beta 2 as high as 15 ng/10(6) cells. Angiotensin II (ANG II) and norepinephrine (NE) each augmented up to threefold the expression and secretion of latent TGF-beta 1 and TGF-beta 2 and also induced a shift in isoform predominance from beta 1 to beta 2. Each agent individually produced hypertrophic growth of neonatal cardiocytes and hyperplastic growth of cardiac fibroblasts. Paradoxically, the combination of NE and ANG II at intermediate and high concentrations resulted in less TGF-beta secretion (compared with either agent alone) and in hypertrophic growth of fibroblasts. These results suggest that the growth-promoting effects of ANG II and NE may in part be mediated via a paracrine stimulation of TGF-beta secretion.


2005 ◽  
Vol 289 (6) ◽  
pp. R1770-R1776 ◽  
Author(s):  
David P. Basile ◽  
Deborah L. Donohoe ◽  
Shane A. Phillips ◽  
Jefferson C. Frisbee

In addition to the long-term renal complications, previous studies suggested that after acute renal failure (ARF), rats manifest an increased pressor response to an overnight infusion of ANG II. The present study tested whether recovery from ARF results in alterations in sensitivity to the peripheral vasculature. ARF was induced in Sprague-Dawley rats by 45 min of bilateral renal ischemia and reperfusion. Animals were allowed to recover renal structure and function for 5–8 wk, after which the acute pressor responses to ANG II were evaluated either in vivo in in situ skeletal muscle arterioles or in isolated gracilis muscle arteries in vitro. Baseline arterial pressure was not different in ARF rats vs. sham-operated controls, although ARF rats exhibited an enhanced pressor response to bolus ANG II infusion compared with control rats. Steady-state plasma ANG II concentration and plasma renin activity were similar between ARF and control rats. Constrictor reactivity of in situ cremasteric arterioles from ARF rats was enhanced in response to increasing concentrations of ANG II; however, no difference was observed in arteriolar responses to elevated Po2, norepinephrine, acetylcholine, or sodium nitroprusside. Isolated gracilis muscle arteries from ARF rats also showed increased vasoconstriction in response to ANG II but not norepinephrine. In conclusion, recovery from ischemic ARF is not associated with hypertension but is associated with increased arteriolar constrictor reactivity to ANG II. Although the mechanisms of this altered responsiveness are unclear, such changes may relate, in part, to cardiovascular complications in patients with ARF and/or after renal transplant.


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