scholarly journals Eucommia ulmoidesOliv. (Du-Zhong) Lignans Inhibit Angiotensin II-Stimulated Proliferation by Affecting P21, P27, and Bax Expression in Rat Mesangial Cells

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Xian Jing ◽  
Wei-Hua Huang ◽  
Yong-Jun Tang ◽  
Ya-Qin Wang ◽  
Hui Li ◽  
...  

Cortex Eucommiae (Du-zhong) is the dried bark of theEucommia ulmoidesOliv. The natural products identified fromDu-zhonginclude lignans, iridoids, flavonoids, polysaccharides, terpenes, and proteins, Liu et al. (2012). Lignans, the main bioactive components, were protective against hypertensive renal injury in spontaneous hypertensive rats in our previous study, Li et al. (2012). Moreover,Eucommialignans also diminished aldose reductase (AR) overexpression in the kidney, Li et al. (2012). However, the pathological mechanism underlying the protective effects ofEucommialignans remains unknown. Cellular proliferation was reported to contribute to important pathological changes in hypertensive renal injuries, and increased angiotensin II (Ang II) expression was reported to be essential for target-organ damage during hypertension. Ang II is the main effective peptide in the renin-angiotensin system and is considered to be a key mediator in the development of hypertensive nephropathy, Rüster and Wolf (2011). Our preliminary results showed thatEucommialignans had inhibitory effects on Ang II-induced proliferation of rat mesangial cells. In the present study, we investigated the effects ofEucommia ulmoideson Ang II-induced proliferation and apoptosis of rat mesangial cells. Cell cycle-related genes P21 and P27, and cell apoptosis-related genes Bax and Bcl-2, were determined.

Nutrients ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 1741 ◽  
Author(s):  
In-Ae Jang ◽  
Eun Kim ◽  
Ji Lim ◽  
Min Kim ◽  
Tae Ban ◽  
...  

The renin-angiotensin system (RAS), especially the angiotensin II (Ang II)/angiotensin II type 1 receptor (AT1R) axis, plays an important role in the aging process of the kidney, through increased tissue reactive oxygen species production and progressively increased oxidative stress. In contrast, the angiotensin 1-7 (Ang 1-7)/Mas receptor (MasR) axis, which counteracts the effects of Ang II, is protective for end-organ damage. To evaluate the ability of resveratrol (RSV) to modulate the RAS in aging kidneys, eighteen-month-old male C57BL/6 mice were divided into two groups that received either normal mouse chow or chow containing resveratrol, for six months. Renal expressions of RAS components, as well as pro- and antioxidant enzymes, were measured and mouse kidneys were isolated for histopathology. Resveratrol-treated mice demonstrated better renal function and reduced albuminuria, with improved renal histologic findings. Resveratrol suppressed the Ang II/AT1R axis and enhanced the AT2R/Ang 1-7/MasR axis. Additionally, the expression of nicotinamide adenine dinucleotide phosphate oxidase 4, 8-hydroxy-2′-deoxyguanosine, 3-nitrotyrosine, collagen IV, and fibronectin was decreased, while the expression of endothelial nitric oxide synthase and superoxide dismutase 2 was increased by resveratrol treatment. These findings demonstrate that resveratrol exerts protective effects on aging kidneys by reducing oxidative stress, inflammation, and fibrosis, through Ang II suppression and MasR activation.


2021 ◽  
Vol 91 (1) ◽  
Author(s):  
Maria Rosaria De Luca ◽  
Daniela Sorriento ◽  
Domenico Massa ◽  
Valeria Valente ◽  
Federica De Luise ◽  
...  

The dysregulation of renin-angiotensin-system (RAS) plays a pivotal role in hypertension and in the development of the related target organ damage (TOD). The main goal of treating hypertension is represented by the long-term reduction of cardiovascular (CV) risk. RAS inhibition either by angiotensin converting enzyme (ACE)-inhibitors or by type 1 Angiotensin II receptors blockers (ARBs), reduce the incidence of CV events in hypertensive patients. Actually, ACE-inhibitors and ARBs have been demonstrated to be effective to prevent, or delay TOD like left ventricular hypertrophy, chronic kidney disease, and atherosclerosis. The beneficial effects of RAS blockers on clinical outcome of hypertensive patients are due to the key role of angiotensin II in the pathogenesis of TOD. In particular, Angiotensin II through an inflammatory-mediated mechanism plays a role in the initiation, progression and vulnerability of atherosclerotic plaque. In addition, Angiotensin II can be considered the hormonal transductor of the pressure overload in cardiac myocytes, and through an autocrine-paracrine mechanism plays a role in the development of left ventricular hypertrophy. Angiotensin II by modulating the redox status and the immune system participates to the development of chronic kidney disease. The RAS blocker should be considered the first therapeutic option in patients with hypertension, even if ACE-inhibitors and ARBs have different impact on CV prevention. ARBs seem to have greater neuro-protective effects, while ACE-inhibitors have greater cardio-protective action.


2020 ◽  
Vol 13 (11) ◽  
pp. 347
Author(s):  
Suhail Hamid ◽  
Imane A. Rhaleb ◽  
Kamal M. Kassem ◽  
Nour-Eddine Rhaleb

The kallikrein–kinin system (KKS) is proposed to act as a counter regulatory system against the vasopressor hormonal systems such as the renin-angiotensin system (RAS), aldosterone, and catecholamines. Evidence exists that supports the idea that the KKS is not only critical to blood pressure but may also oppose target organ damage. Kinins are generated from kininogens by tissue and plasma kallikreins. The putative role of kinins in the pathogenesis of hypertension is discussed based on human mutation cases on the KKS or rats with spontaneous mutation in the kininogen gene sequence and mouse models in which the gene expressing only one of the components of the KKS has been deleted or over-expressed. Some of the effects of kinins are mediated via activation of the B2 and/or B1 receptor and downstream signaling such as eicosanoids, nitric oxide (NO), endothelium-derived hyperpolarizing factor (EDHF) and/or tissue plasminogen activator (T-PA). The role of kinins in blood pressure regulation at normal or under hypertension conditions remains debatable due to contradictory reports from various laboratories. Nevertheless, published reports are consistent on the protective and mediating roles of kinins against ischemia and cardiac preconditioning; reports also demonstrate the roles of kinins in the cardiovascular protective effects of the angiotensin-converting enzyme (ACE) and angiotensin type 1 receptor blockers (ARBs).


1999 ◽  
Vol 277 (1) ◽  
pp. F41-F47 ◽  
Author(s):  
Robert L. Chevalier ◽  
Barbara A. Thornhill ◽  
Jennifer T. Wolstenholme

Renal angiotensin II (ANG II) is increased as a result of unilateral ureteral obstruction (UUO), and angiotensin AT2 receptors predominate over AT1 receptors in the early postnatal period. To examine the renal cellular response to 3-day UUO in the neonatal and adult rat, AT1and AT2 receptors were inhibited by losartan and PD-123319, respectively. Additional rats received exogenous ANG II, 0.5 mg ⋅ kg−1 ⋅ day−1. Renal cellular proliferation and apoptosis were quantitated by proliferating cell nuclear antigen and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling technique, respectively. In the neonate, UUO reduced proliferation and increased tubular apoptosis. Losartan had no detectable cellular effect, whereas PD-123319 increased cellular proliferation and suppressed apoptosis, and exogenous ANG II stimulated apoptosis. In the adult, UUO increased cellular proliferation as well as apoptosis, whereas losartan, PD-123319, and exogenous ANG II did not alter the cellular response. In conclusion, UUO impairs renal growth in the neonate by reducing proliferation and stimulating apoptosis, at least in part through angiotensin AT2 receptors. UUO stimulates both renal cellular proliferation and apoptosis in the adult, but these effects are independent of ANG II. We speculate that the unique early responses of the developing kidney to urinary tract obstruction are mediated by a highly activated renin-angiotensin system and preponderance of AT2 receptors.


Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Sathnur Pushpakumar ◽  
Sourav Kundu ◽  
Denise Coley ◽  
Srikanth Givvimani ◽  
Suresh C Tyagi ◽  
...  

Activation of renin-angiotensin system and production of Angiotensin-II plays an important role in several pathological processes leading to end stage renal disease. Sustained hypertension induces renovascular remodeling in both intra and extra-renal vasculature by altering extracellular matrix (ECM) components. Recent studies in vascular remodeling have shown strain-dependent phenotypic variation in carotid artery and in pulmonary hypertension indicating a genetic basis for disease susceptibility. We hypothesized that sensitivity to develop hypertension to angiotensin-II infusion and subsequent renovascular remodeling will vary depending on the genetic background. C57BL/6J (WT) and TIMP2 -/- mice were used in this study. Osmotic pumps loaded with Angiotensin-II (Ang-II) were introduced into a dorsal subcutaneous pocket for delivery at 250 ng. kg -1 . min -1 . Pumps loaded with saline served as controls for both groups. Blood pressure, renal vascular blood flow, renal vascular density, collagen and elastin deposition, oxidative stress and tissue levels of MMP-2 and MMP-9 were determined. Results: TIMP2 -/- mice had higher baseline mean blood pressure (130.5±6.4 mm Hg) compared to WT mice (111.07±7.3 mm Hg). After 4 weeks of Ang-II treatment, mean arterial pressure increased to 150.33±11.9 in TIMP2 -/- mice compared to 129.9±5.7 mm Hg in WT mice. The renal cortical blood flow was reduced in TIMP2 -/- mice (1125 flux units) compared to WT (1350 flux units) and untreated controls. Barium angiography demonstrated decreased renal vascular density in TIMP2 -/- mice compared to WT group. Peri-glomerular and vascular collagen deposition was increased in TIMP2 -/- and WT, whereas elastin was reduced and disrupted in TIMP2 -/- renal vasculature. Intracellular reactive oxygen species production was predominant in TIMP2 -/- group than in WT or control animals. Conclusion: Our results suggest that in Ang-II induced hypertension, renovascular response is strain dependent and TIMP2 -/- mice appear to be more susceptible to end organ damage than WT mice.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Yongjun Zhu ◽  
Hongwang Cui ◽  
Jie Lv ◽  
Haiqin Liang ◽  
Yanping Zheng ◽  
...  

AbstractAbnormal renin-angiotensin system (RAS) activation plays a critical role in the initiation and progression of chronic kidney disease (CKD) by directly mediating renal tubular cell apoptosis. Our previous study showed that necroptosis may play a more important role than apoptosis in mediating renal tubular cell loss in chronic renal injury rats, but the mechanism involved remains unknown. Here, we investigate whether blocking the angiotensin II type 1 receptor (AT1R) and/or angiotensin II type 2 receptor (AT2R) beneficially alleviates renal tubular cell necroptosis and chronic kidney injury. In an angiotensin II (Ang II)-induced renal injury mouse model, we found that blocking AT1R and AT2R effectively mitigates Ang II-induced increases in necroptotic tubular epithelial cell percentages, necroptosis-related RIP3 and MLKL protein expression, serum creatinine and blood urea nitrogen levels, and tubular damage scores. Furthermore, inhibition of AT1R and AT2R diminishes Ang II-induced necroptosis in HK-2 cells and the AT2 agonist CGP42112A increases the percentage of necroptotic HK-2 cells. In addition, the current study also demonstrates that Losartan and PD123319 effectively mitigated the Ang II-induced increases in Fas and FasL signaling molecule expression. Importantly, disruption of FasL significantly suppressed Ang II-induced increases in necroptotic HK-2 cell percentages, and necroptosis-related proteins. These results suggest that Fas and FasL, as subsequent signaling molecules of AT1R and AT2R, might involve in Ang II-induced necroptosis. Taken together, our results suggest that Ang II-induced necroptosis of renal tubular cell might be involved both AT1R and AT2R and the subsequent expression of Fas, FasL signaling. Thus, AT1R and AT2R might function as critical mediators.


Antioxidants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 936
Author(s):  
Chien-Lin Lu ◽  
Cai-Mei Zheng ◽  
Kuo-Cheng Lu ◽  
Min-Tser Liao ◽  
Kun-Lin Wu ◽  
...  

The accumulation of the uremic toxin indoxyl sulfate (IS) induces target organ damage in chronic kidney disease (CKD) patients, and causes complications including cardiovascular diseases, renal osteodystrophy, muscle wasting, and anemia. IS stimulates reactive oxygen species (ROS) production in CKD, which impairs glomerular filtration by a direct cytotoxic effect on the mesangial cells. IS further reduces antioxidant capacity in renal proximal tubular cells and contributes to tubulointerstitial injury. IS-induced ROS formation triggers the switching of vascular smooth muscular cells to the osteoblastic phenotype, which induces cardiovascular risk. Low-turnover bone disease seen in early CKD relies on the inhibitory effects of IS on osteoblast viability and differentiation, and osteoblastic signaling via the parathyroid hormone. Excessive ROS and inflammatory cytokine releases caused by IS directly inhibit myocyte growth in muscle wasting via myokines’ effects. Moreover, IS triggers eryptosis via ROS-mediated oxidative stress, and elevates hepcidin levels in order to prevent iron flux in circulation in renal anemia. Thus, IS-induced oxidative stress underlies the mechanisms in CKD-related complications. This review summarizes the underlying mechanisms of how IS mediates oxidative stress in the pathogenesis of CKD’s complications. Furthermore, we also discuss the potential role of oral AST-120 in attenuating IS-mediated oxidative stress after gastrointestinal adsorption of the IS precursor indole.


2016 ◽  
Vol 311 (2) ◽  
pp. H404-H414 ◽  
Author(s):  
Carlos M. Ferrario ◽  
Sarfaraz Ahmad ◽  
Jasmina Varagic ◽  
Che Ping Cheng ◽  
Leanne Groban ◽  
...  

Although it is well-known that excess renin angiotensin system (RAS) activity contributes to the pathophysiology of cardiac and vascular disease, tissue-based expression of RAS genes has given rise to the possibility that intracellularly produced angiotensin II (Ang II) may be a critical contributor to disease processes. An extended form of angiotensin I (Ang I), the dodecapeptide angiotensin-(1–12) [Ang-(1–12)], that generates Ang II directly from chymase, particularly in the human heart, reinforces the possibility that an alternative noncanonical renin independent pathway for Ang II formation may be important in explaining the mechanisms by which the hormone contributes to adverse cardiac and vascular remodeling. This review summarizes the work that has been done in evaluating the functional significance of Ang-(1–12) and how this substrate generated from angiotensinogen by a yet to be identified enzyme enhances knowledge about Ang II pathological actions.


Hypertension ◽  
2015 ◽  
Vol 66 (suppl_1) ◽  
Author(s):  
Kim Ramil C Montaniel ◽  
Jing Wu ◽  
Matthew R Bersi ◽  
Liang Xiao ◽  
Hana A Itani ◽  
...  

We and others have shown that hypertension (HTN) is associated with a striking deposition of collagen in the vascular adventitia. This causes vascular stiffening, which increases pulse wave velocity and contributes to end-organ damage. Through a screen of vascular microRNAs (miRNAs), we found that miR-762 is the most upregulated miRNA in mice with angiotensin II (Ang II)-induced HTN. qRT-PCR confirmed that miR-762 is upregulated 6.35±1.22 (p=0.03) fold in aortas of Ang II-infused mice compared with controls. This was a direct effect of Ang II, as miR-762 upregulation was not eliminated by lowering blood pressure with hydralazine and hydrochlorothiazide and was increased only 2-fold in DOCA salt HTN. To study the role of miR-762 in HTN, we administered a locked nucleic acid inhibitor of miR-762 (antagomiR-762). AntagomiR-762 administration did not alter the hypertensive response to Ang II, yet it normalized stress-strain relationships and aortic energy storage that occurs in systole (Table). Further studies showed that antagomiR-762 dramatically affected vascular matrix proteins, reducing mRNA for several collagens and fibronectin and dramatically upregulating collagenases MMP1a, 8 and 13 (Table). Thus, miR-762 has a major role in modulating vascular stiffening and its inhibition dramatically inhibits pathological fibrosis, enhances matrix degradation and normalizes aortic stiffness. AntagomiR-762 might represent a new approach to prevent aortic stiffening and its consequent end-organ damage.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Hai-Xia Shi ◽  
Jiajun Yang ◽  
Tao Yang ◽  
Yong-Liang Xue ◽  
Jun Liu ◽  
...  

α-Asarone is the major therapeutical constituent ofAcorus tatarinowiiSchott. In this study, the potential protective effects ofα-asarone against endothelial cell injury induced by angiotensin II were investigatedin vitro. The EA.hy926 cell line derived from human umbilical vein endothelial cells was pretreated withα-asarone (10, 50, 100 µmol/L) for 1 h, followed by coincubation with Ang II (0.1 µmol/L) for 24 h. Intracellular nitric oxide (NO) and reactive oxygen species (ROS) were detected by fluorescent dyes, and phosphorylation of endothelial nitric oxide synthase (eNOS) atSer1177was determined by Western blotting.α-Asarone dose-dependently mitigated the Ang II-induced intracellular NO reduction (P<0.01versus model) and ROS production (P<0.01versus model). Furthermore, eNOS phosphorylation (Ser1177) by acetylcholine was significantly inhibited by Ang II, while pretreatment for 1 h withα-asarone partially prevented this effect (P<0.05versus model). Additionally, cell viability determined by the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay (105~114.5% versus control,P>0.05) was not affected after 24 h of incubation withα-asarone at 1–100 µmol/L. Therefore,α-asarone protects against Ang II-mediated damage of endothelial cells and may be developed to prevent injury to cardiovascular tissues.


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