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Santos SHS, Andrade JMO. Angiotensin 1-7: a peptide for preventing and treating metabolic syndrome. Peptides 2014; 59:34-41. [PMID: 25017239 DOI: 10.1016/j.peptides.2014.07.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 07/02/2014] [Accepted: 07/02/2014] [Indexed: 12/14/2022]
Abstract
Angiotensin-(1-7) is one of the most important active peptides of the renin-angiotensin system (RAS) with recognized cardiovascular relevance; however several studies have shown the potential therapeutic role of Ang-(1-7) on treating and preventing metabolic disorders as well. This peptide achieves a special importance considering that in the last few decades obesity and metabolic syndrome (MS) have become a growing worldwide health problem. Angiotensin (Ang) II is the most studied component of RAS and is increased during obesity, diabetes and dyslipidemia (MS); some experimental evidence has shown that Ang II modulates appetite and metabolism as well as mechanisms that induce adipose tissue growth and metabolism in peripheral organs. Recent articles demonstrated that Ang-(1-7)/Mas axis modulates lipid and glucose metabolism and counterregulates the effects of Ang II. Based on these data, angiotensin-converting enzyme 2 (ACE2)/Ang-(1-7)/Mas pathway activation have been advocated as a new tool for treating metabolic diseases. This review summarizes the new evidence from animal and human experiments indicating the use of Ang-(1-7) in prevention and treatment of obesity and metabolic disorders.
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Affiliation(s)
- Sérgio Henrique Sousa Santos
- Pharmacology Department, Biological Sciences Institute, Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, Minas Gerais, Brazil; Laboratory of Health Science, Postgraduate Program in Health Sciences, Universidade Estadual de Montes Claros (UNIMONTES), Montes Claros, Minas Gerais, Brazil.
| | - João Marcus Oliveira Andrade
- Laboratory of Health Science, Postgraduate Program in Health Sciences, Universidade Estadual de Montes Claros (UNIMONTES), Montes Claros, Minas Gerais, Brazil
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Abstract
Long-term survival following liver transplantation is profoundly affected by conditions unrelated to graft function. Many causes of mortality are contributed to by the metabolic syndrome. The approach to metabolic syndrome in liver transplant recipients requires consideration of transplant-specific factors, particularly immunosuppression. Enhancing long-term outcomes for liver transplant recipients necessitates minimizing the amount of immunosuppression required to prevent rejection. Studies to determine the optimal approach to minimize the impact of metabolic syndrome and complications of immunosuppression in transplant recipients are needed.
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Affiliation(s)
- Michael R Charlton
- Department of Medicine, Intermountain Medical Center, 5169 South Cottonwood Street, Murray, UT 84107, USA.
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The Ang-(1-7)/Mas-1 axis attenuates the expression and signalling of TGF-β1 induced by AngII in mouse skeletal muscle. Clin Sci (Lond) 2014; 127:251-64. [PMID: 24588264 DOI: 10.1042/cs20130585] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
AngII (angiotensin II) induces pathological conditions such as fibrosis in skeletal muscle. In this process, AngII increases ROS (reactive oxygen species) and induces a biphasic phosphorylation of p38 MAPK (mitogen-activated protein kinase). In addition, AngII stimulates the expression and production of TGF (transforming growth factor)-β1 via a mechanism dependent on ROS production mediated by NADPH oxidase (NOX) and p38 MAPK activation. In the present study, we investigated whether Ang-(1-7) [angiotensin-(1-7)], through the Mas-1 receptor, can counteract the signalling induced by AngII in mouse skeletal muscle and cause a decrease in the expression and further activity of TGF-β1 in skeletal muscle cells. Our results show that Ang-(1-7) decreased the expression of TGF-β1 induced by AngII in a dose-dependent manner. In addition, we observed that Ang-(1-7) prevented the increase in TGF-β1 expression induced by AngII, ROS production dependent on NOX and the early phase of p38 MAPK phosphorylation. Interestingly, Ang-(1-7) also prevented the late phase of p38 MAPK phosphorylation, Smad-2 phosphorylation and Smad-4 nuclear translocation, an increase in transcriptional activity, as determined using the p3TP-lux reporter, and fibronectin levels, all of which are dependent on the TGF-β1 levels induced by AngII. We also demonstrated that Ang-(1-7) prevented the increase in TGF-β1, fibronectin and collagen content in the diaphragm of mice infused with AngII. All of these effects were reversed by the administration of A779, indicating the participation of Mas-1. In conclusion, our findings support the hypothesis that Ang-(1-7) decreases the expression and further biological activity of TGF-β1 induced by AngII in vitro and in vivo.
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Guillaud O, Gurram KC, Puglia M, Lilly L, Adeyi O, Renner EL, Selzner N. Angiotensin blockade does not affect fibrosis progression in recurrent hepatitis C after liver transplantation. Transplant Proc 2014; 45:2331-6. [PMID: 23953545 DOI: 10.1016/j.transproceed.2013.01.067] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Accepted: 01/14/2013] [Indexed: 02/08/2023]
Abstract
BACKGROUND Liver transplantation (LT) for hepatitis C virus (HCV)-related end-stage liver disease is impaired by universal disease recurrence and suboptimal response to antiviral therapy. Inhibition of angiotensin-II signalling by angiotensin-converting enzyme inhibitors (ACE-I) or angiotensin-II receptor blockers (ARB) decreases hepatic stellate cell activation in vitro and hepatic fibrogenesis in animal models. A single-center retrospective analysis suggested that angiotensin blockade (AB) inhibits fibrosis progression in recurrent HCV post-LT. This study assessed the effect of AB on fibrosis progression in an independent patient cohort. METHODS Chart review of all patients who underwent transplantation in our institution for HCV-related ESLD between January 2000 and February 2008 revealed 109 patients with ≥2 protocol liver biopsies and free of antiviral therapy post-LT up to the last biopsy analyzed; 27 of 109 patients were treated with ACE-I/ARB for ≥12 months, 82 were not. Fibrosis was staged using METAVIR. RESULTS Live-donor LT was more frequent in controls than in the AB group (25% vs 11%; P < .05). However, parameters known to affect outcome of recurrent HCV, including donor age, prevalence of diabetes, acute cellular rejection, and immunosuppression, were similar in both groups. Time between first and last biopsy (median, 23 months), stage of fibrosis, fibrosis progression rates (median 0.47 vs 0.45 unit/y; P = .46), and time to develop fibrosis stage ≥2 did not differ between groups. Results held true if deceased-donor LT were analyzed separately. CONCLUSION Our study does not support the contention of a previous report that use of AB reduces fibrosis progression in recurrent HCV post-LT.
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Affiliation(s)
- O Guillaud
- Multiorgan Transplant Program, and Department of Pathology, University Health Network, University of Toronto, Toronto, ON, Canada
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Garg M, Burrell LM, Velkoska E, Griggs K, Angus PW, Gibson PR, Lubel JS. Upregulation of circulating components of the alternative renin-angiotensin system in inflammatory bowel disease: A pilot study. J Renin Angiotensin Aldosterone Syst 2014; 16:559-69. [PMID: 24505094 DOI: 10.1177/1470320314521086] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2013] [Accepted: 12/15/2013] [Indexed: 12/12/2022] Open
Abstract
INTRODUCTION The relationship between intestinal inflammation and circulating components of the renin-angiotensin system (RAS) is poorly understood. MATERIALS AND METHODS Demographic and clinical data were obtained from healthy controls and patients with inflammatory bowel disease (IBD). Plasma concentrations of the classical RAS components (angiotensin-converting enzyme (ACE) and angiotensin II (Ang II)) and alternative RAS components (ACE2 and angiotensin (1-7) (Ang (1-7))) were analysed by radioimmuno- and enzymatic assays. Systemic inflammation was assessed using serum C-reactive protein (CRP), white cell count, platelet count and albumin, and intestinal inflammation by faecal calprotectin. RESULTS Nineteen healthy controls (11 female; mean age 38 years, range 23-68), 19 patients with Crohn's disease (11 female; aged 45 years, range 23-76) and 15 patients with ulcerative colitis (6 female; aged 42 years, 26-64) were studied. Circulating classical RAS component levels were similar across the three groups, whereas ACE2 activity and Ang (1-7) concentrations were higher in patients with IBD compared to controls (ACE2: 21.5 vs 13.3 pmol/ml/min, p<0.05; Ang (1-7): 22.8 vs 14.1 pg/ml, p<0.001). Ang (1-7) correlated weakly with platelet and white cell counts, but not calprotectin or CRP, in patients with IBD. CONCLUSIONS Circulating components of the alternative RAS are increased in patients with IBD.
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Affiliation(s)
- Mayur Garg
- Department of Gastroenterology and Hepatology, Eastern Health, Australia Eastern Health Clinical School, Monash University, Australia
| | | | - Elena Velkoska
- Department of Medicine, The University of Melbourne, Australia
| | - Karen Griggs
- Department of Medicine, The University of Melbourne, Australia
| | - Peter W Angus
- Department of Medicine, The University of Melbourne, Australia Gastroenterology and Liver Transplant Unit, Austin Hospital, Australia
| | - Peter R Gibson
- Eastern Health Clinical School, Monash University, Australia Department of Gastroenterology, Department of Gastroenterology, The Alfred Hospital and Monash University, Australia
| | - John S Lubel
- Department of Gastroenterology and Hepatology, Eastern Health, Australia Eastern Health Clinical School, Monash University, Australia
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Oikawa H, Maesawa C, Tatemichi Y, Nishinari Y, Nishiya M, Mizugai H, Ikeda A, Oikawa K, Takikawa Y, Masuda T. A disintegrin and metalloproteinase 17 (ADAM17) mediates epidermal growth factor receptor transactivation by angiotensin II on hepatic stellate cells. Life Sci 2014; 97:137-44. [PMID: 24412389 DOI: 10.1016/j.lfs.2013.12.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 12/02/2013] [Accepted: 12/18/2013] [Indexed: 02/04/2023]
Abstract
AIMS Epidermal growth factor receptor (EGFR) transactivation induced by angiotensin II (Ang II) participates in the progression of various diseases. A disintegrin and metalloproteinase 17 (ADAM17) is thought to promote renal fibrosis, cardiac hypertrophy with fibrosis and atherosclerosis by activation of the EGFR through secretion of EGFR ligands. The purpose of this study was to investigate whether Ang II-induced EGFR transactivation occurs on hepatic stellate cells (HSCs) and whether the reaction is mediated via ADAM17. MAIN METHODS Ang II-induced EGFR transactivation and cellular proliferation of the human HSC line LI90 were investigated using Western blotting and ATP assay, respectively. Ang II-induced secretion of mature amphiregulin into the cell culture medium was evaluated by enzyme-linked immunosorbent assay (ELISA). KEY FINDINGS An inhibitor of ADAM17, TAPI-1, as well as antagonists of EGFR and angiotensin II type-1 receptor (AT1), attenuated Ang II-induced EGFR transactivation and proliferation of LI90 cells. Furthermore, silencing of ADAM17 inhibited Ang II-induced secretion of mature amphiregulin in addition to EGFR transactivation. SIGNIFICANCE These results indicate that ADAM17 mediates Ang II-induced EGFR transactivation on HSCs, and that this process may participate in the progression of liver fibrosis.
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Affiliation(s)
- Hiroki Oikawa
- Department of Pathology, School of Medicine, Iwate Medical University, 2-1-1 Nishitokuta, Yahaba-Cho, Shiwa-Gun, Iwate 028-3694, Japan.
| | - Chihaya Maesawa
- Department of Pathology, School of Medicine, Iwate Medical University, 2-1-1 Nishitokuta, Yahaba-Cho, Shiwa-Gun, Iwate 028-3694, Japan; Department of Tumor Biology, Institute of Biomedical Science, Iwate Medical University, 2-1-1 Nishitokuta, Yahaba-Cho, Shiwa-Gun, Iwate 028-3694, Japan
| | - Yoshinori Tatemichi
- Department of Internal Medicine, School of Medicine, Iwate Medical University, Uchimaru 19-1, Morioka, Iwate 020-8505, Japan
| | - Yutaka Nishinari
- Department of Tumor Biology, Institute of Biomedical Science, Iwate Medical University, 2-1-1 Nishitokuta, Yahaba-Cho, Shiwa-Gun, Iwate 028-3694, Japan; Department of Surgery, School of Medicine, Iwate Medical University, Uchimaru 19-1, Morioka, Iwate 020-8505, Japan
| | - Masao Nishiya
- Department of Pathology, School of Medicine, Iwate Medical University, 2-1-1 Nishitokuta, Yahaba-Cho, Shiwa-Gun, Iwate 028-3694, Japan
| | - Hisata Mizugai
- Department of Pathology, School of Medicine, Iwate Medical University, 2-1-1 Nishitokuta, Yahaba-Cho, Shiwa-Gun, Iwate 028-3694, Japan; Department of Internal Medicine, School of Medicine, Iwate Medical University, Uchimaru 19-1, Morioka, Iwate 020-8505, Japan
| | - Aya Ikeda
- Department of Pathology, School of Medicine, Iwate Medical University, 2-1-1 Nishitokuta, Yahaba-Cho, Shiwa-Gun, Iwate 028-3694, Japan
| | - Kanta Oikawa
- Department of Internal Medicine, School of Medicine, Iwate Medical University, Uchimaru 19-1, Morioka, Iwate 020-8505, Japan
| | - Yasuhiro Takikawa
- Department of Internal Medicine, School of Medicine, Iwate Medical University, Uchimaru 19-1, Morioka, Iwate 020-8505, Japan
| | - Tomoyuki Masuda
- Department of Pathology, School of Medicine, Iwate Medical University, 2-1-1 Nishitokuta, Yahaba-Cho, Shiwa-Gun, Iwate 028-3694, Japan
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Matthew Morris E, Fletcher JA, Thyfault JP, Rector RS. The role of angiotensin II in nonalcoholic steatohepatitis. Mol Cell Endocrinol 2013; 378:29-40. [PMID: 22579612 DOI: 10.1016/j.mce.2012.04.013] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Accepted: 04/30/2012] [Indexed: 01/18/2023]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is now considered the most prevalent chronic liver disease, affecting over 30% of the US adult population. NAFLD is strongly linked to insulin resistance and is considered the hepatic manifestation of the metabolic syndrome. Activation of the renin-angiotensin-aldosterone system (RAAS) is known to play a role in the hypertension observed in the metabolic syndrome and also is thought to play a central role in insulin resistance and NAFLD. Angiotensin II (AngII) is considered the primary effector of the physiological outcomes of RAAS signaling, both at the systemic and local tissue level. Herein, we review data describing the potential involvement of AngII-mediated signaling at multiple levels in the development and progression of NAFLD, including increased steatosis, inflammation, insulin resistance, and fibrosis. Additionally, we present recent work on the potential therapeutic benefits of RAAS and angiotensin II signaling inhibition in rodent models and patients with NAFLD.
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Affiliation(s)
- E Matthew Morris
- Department of Internal Medicine - Division of Gastroenterology and Hepatology, University of Missouri, MO, United States; Harry S Truman Memorial Veterans Medical Center, Columbia, MO 65201, United States.
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Herath CB, Grace JA, Angus PW. Therapeutic potential of targeting the renin angiotensin system in portal hypertension. World J Gastrointest Pathophysiol 2013; 4:1-11. [PMID: 23596549 PMCID: PMC3627462 DOI: 10.4291/wjgp.v4.i1.1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Revised: 11/15/2012] [Accepted: 01/05/2013] [Indexed: 02/06/2023] Open
Abstract
Portal hypertension is responsible for the bulk of the morbidity and mortality in patients with cirrhosis. Drug therapy to reduce portal pressure involves targeting two vascular beds. The first approach is to reduce intra hepatic vascular tone induced by the activity of powerful vasocontrictors such as angiotensin II, endothelin-1 and the sympathetic system and mediated via contraction of perisinusoidal myofibroblasts and pervascular smooth muscle cells. The second approach is to reduce mesenteric and portal blood flow. Non-selective β-blockers are widely used and have been shown to prolong patient survival and reduce oesophageal variceal bleeding in advanced cirrhosis. However many patients are unable to tolerate these drugs and they are ineffective in a significant proportion of patients. Unfortunately there are no other drug therapies that have proven efficacy in the treatment of portal hypertension and prevention of variceal bleeding. This review briefly outlines current therapeutic approaches to the management of portal hypertension, and the evidence supporting the role of the renin angiotensin system (RAS) and the use of RAS blockers in this condition. It will also outline recent advances in RAS research that could lead to the development of new treatments focusing in particular on the recently discovered "alternate axis" of the RAS.
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Paschos P, Tziomalos K. Nonalcoholic fatty liver disease and the renin-angiotensin system: Implications for treatment. World J Hepatol 2012; 4:327-31. [PMID: 23355909 PMCID: PMC3554795 DOI: 10.4254/wjh.v4.i12.327] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Revised: 10/18/2012] [Accepted: 11/17/2012] [Indexed: 02/06/2023] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) is the commonest liver disease in Western countries. Treatment of NAFLD is currently based on lifestyle measures and no effective pharmacologic treatment is available so far. Emerging evidence, mainly from animal studies, suggests that the renin-angiotensin-aldosterone system may be of major importance in the pathogenesis of NAFLD and indicates that angiotensin-converting enzyme inhibitors (ACE-I) and angiotensin receptor blockers (ARBs) as a potentially useful therapeutic approach. However, data from human studies are limited and contradictory. In addition, there are few randomized controlled trials (RCTs) on the effects of ACE-I or ARB in patients with NAFLD and most data are from retrospective studies, pilot prospective studies and post hoc analyses of clinical trials. Accordingly, more and larger RCTs are needed to directly assess the effectiveness of ACE-I and ARBs in NAFLD.
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Affiliation(s)
- Paschalis Paschos
- Paschalis Paschos, Konstantinos Tziomalos, First Propedeutic Department of Internal Medicine, Medical School, Aristotle University of Thessaloniki, AHEPA Hospital, 54636 Thessaloniki, Greece
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Lee KC, Chan CC, Yang YY, Hsieh YC, Huang YH, Lin HC. Aliskiren attenuates chronic carbon tetrachloride-induced liver injury in mice. Eur J Clin Invest 2012; 42:1261-71. [PMID: 22998019 DOI: 10.1111/j.1365-2362.2012.02725.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
BACKGROUND Increased angiotensin II (Ang II) plays an important role in liver inflammation and fibrogenesis. Chronic administration of aliskiren, a newly developed direct renin inhibitor, decreases Ang II in the hypertensive patients and animals. AIMS Our study aims to evaluate the possible protective effects of chronic administration of aliskiren in a chronic liver injury model. METHODS C57BL6 mice were injected intraperitoneally with carbon tetrachloride (CCl(4)) to induce chronic liver injury. The injured mice were randomly assigned to aliskiren-treated (25 mg/kg per day for 2 weeks, the CCl(4) + Ali group) or untreated group (the CCl(4) group). Mice without CCl(4) and aliskiren administration served as the normal control. RESULTS In the CCl(4)-injured mice, aliskiren attenuated liver inflammation and fibrosis. The levels of hepatocyte apoptosis, lipid peroxidation production, the activation of hepatic stellate cells and Kupffer cells, hepatic expression of p47 phox, inflammatory mediators and profibrotic markers were reduced in the CCl(4) + Ali group. Furthermore, aliskiren decreased Ang II, activated the renal expression of renin, but down-regulated the hepatic expression of renin and renin receptor in the CCl(4)-injected mice. CONCLUSIONS Aliskiren attenuates chronic liver injury in the CCl(4)-treated mice by reducing Ang II. Direct renin inhibition may serve as a potential treatment for chronic liver injury.
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Affiliation(s)
- Kuei-Chuan Lee
- Division of Gastroenterology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
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Abstract
AIM To evaluate the antifibrotic effect of telmisartan, an angiotensin II receptor blocker, in bile duct-ligated rats. METHODS Adult Sprague-Dawley rats were allocated to 3 groups: sham-operated rats, model rats underwent common bile duct ligation (BDL), and BDL rats treated with telmisartan (8 mg/kg, po, for 4 weeks). The animals were sacrificed on d 29, and liver histology was examined, the Knodell and Ishak scores were assigned, and the expression of angiotensin-converting enzyme (ACE) and ACE2 was evaluated with immunohistochemical staining. The mRNAs and proteins associated with liver fibrosis were evaluated using RTQ-PCR and Western blot, respectively. RESULTS The mean fibrosis score of BDL rats treated with telmisartan was significantly lower than that of the model rats (1.66±0.87 vs 2.13±0.35, P=0.015). However, there was no significant difference in inflammation between the two groups, both of which showed moderate inflammation. Histologically, treatment with telmisartan significantly ameliorated BDL-caused the hepatic fibrosis. Treatment with telmisartan significantly upregulated the mRNA levels of ACE2 and MAS, and decreased the mRNA levels of ACE, angiotensin II type 1 receptor (AT1-R), collagen type III, and transforming growth factor β1 (TGF-β1). Moreover, treatment with telmisartan significantly increased the expression levels of ACE2 and MAS proteins, and inhibited the expression levels of ACE and AT1-R protein. CONCLUSION Telmisartan attenuates liver fibrosis in bile duct-ligated rats via increasing ACE2 expression level.
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Cabello-Verrugio C, Morales MG, Cabrera D, Vio CP, Brandan E. Angiotensin II receptor type 1 blockade decreases CTGF/CCN2-mediated damage and fibrosis in normal and dystrophic skeletal muscles. J Cell Mol Med 2012; 16:752-64. [PMID: 21645240 PMCID: PMC3822846 DOI: 10.1111/j.1582-4934.2011.01354.x] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Connective tissue growth factor (CTGF/CCN-2) is mainly involved in the induction of extracellular matrix (ECM) proteins. The levels of CTGF correlate with the degree and severity of fibrosis in many tissues, including dystrophic skeletal muscle. The CTGF overexpression in tibialis anterior skeletal muscle using an adenoviral vector reproduced many of the features observed in dystrophic muscles including muscle damage and regeneration, fibrotic response and decrease in the skeletal muscle strength. The renin-angiotensin system is involved in the genesis and progression of fibrotic diseases through its main fibrotic components angiotensin-II and its transducer receptor AT-1. The use of AT-1 receptor blockers (ARB) has been shown to decrease fibrosis. In this paper, we show the effect of AT-1 receptor blockade on CTGF-dependent biological activity in skeletal muscle cells as well as the response to CTGF overexpression in normal skeletal muscle. Our results show that in myoblasts ARB decreased CTGF-mediated increase of ECM protein levels, extracellular signal regulated kinases 1/2 (ERK-1/2) phosphorylation and stress fibres formation. In tibialis anterior muscle overexpressing CTGF using an adenovirus, ARB treatment decreased CTGF-mediated increase of ECM molecules, α-SMA and ERK-1/2 phosphorylation levels. Quite remarkable, ARB was able to prevent the loss of contractile force of tibialis anterior muscles overexpressing CTGF. Finally, we show that ARB decreased the levels of fibrotic proteins, CTGF and ERK-1/2 phosphorylation augmented in a dystrophic skeletal muscle from mdx mice. We propose that ARB is a novel pharmacological tool that can be used to decrease the fibrosis induced by CTGF in skeletal muscle associated with muscular dystrophies.
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Affiliation(s)
- Claudio Cabello-Verrugio
- Laboratorio de Diferenciación Celular y Patología, Centro de Regulación Celular y Patología (CRCP), Departamento de Biología Celular y Molecular, Pontificia Universidad Católica de Chile, Santiago, Chile.
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Mackawy AM, Badawy ME, Megahed OAERY. Angiotensin converting enzyme (ACE D/I) polymorphism and its relation to liver fibrosis progression in Egyptian patients with chronic hepatitis C virus infection. EGYPTIAN JOURNAL OF MEDICAL HUMAN GENETICS 2012. [DOI: 10.1016/j.ejmhg.2012.06.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
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Singh S, Watt KD. Long-term medical management of the liver transplant recipient: what the primary care physician needs to know. Mayo Clin Proc 2012; 87:779-90. [PMID: 22763347 PMCID: PMC3498400 DOI: 10.1016/j.mayocp.2012.02.021] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Revised: 02/07/2012] [Accepted: 02/16/2012] [Indexed: 12/18/2022]
Abstract
Recognition, management, and prevention of medical complications and comorbidities after liver transplant is the key to improved long-term outcomes. Beyond allograft-related complications, metabolic syndrome, cardiovascular disease, renal dysfunction, and malignancies are leading causes of morbidity and mortality in this patient population. Primary care physicians have an important role in improving outcomes of liver transplant recipients and are increasingly relied on for managing these complex patients. This review serves to assist the primary care physician in the long-term management issues of liver transplant recipients.
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Key Words
- acei, angiotensin converting enzyme inhibitor
- arb, angiotensin receptor blocker
- ckd, chronic kidney disease
- cni, calcineurin inhibitor
- ibd, inflammatory bowel disease
- lt, liver transplant
- mmf, mycophenolate mofetil
- mtor, mammalian target of rapamycin
- nash, nonalcoholic steatohepatitis-related cirrhosis
- olt, orthotopic liver transplant
- psc, primary sclerosing cholangitis
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Affiliation(s)
| | - Kymberly D. Watt
- Correspondence: Address to Kymberly D. Watt, MD, Division of Gastroenterology and Hepatology, Mayo Clinic, 200 First St SW, Rochester, MN 55905
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Update on new aspects of the renin-angiotensin system in liver disease: clinical implications and new therapeutic options. Clin Sci (Lond) 2012; 123:225-39. [PMID: 22548407 DOI: 10.1042/cs20120030] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The RAS (renin-angiotensin system) is now recognized as an important regulator of liver fibrosis and portal pressure. Liver injury stimulates the hepatic expression of components of the RAS, such as ACE (angiotensin-converting enzyme) and the AT(1) receptor [AngII (angiotensin II) type 1 receptor], which play an active role in promoting inflammation and deposition of extracellular matrix. In addition, the more recently recognized structural homologue of ACE, ACE2, is also up-regulated. ACE2 catalyses the conversion of AngII into Ang-(1-7) [angiotensin-(1-7)], and there is accumulating evidence that this 'alternative axis' of the RAS has anti-fibrotic, vasodilatory and anti-proliferative effects, thus counterbalancing the effects of AngII in the liver. The RAS is also emerging as an important contributor to the pathophysiology of portal hypertension in cirrhosis. Although the intrahepatic circulation in cirrhosis is hypercontractile in response to AngII, resulting in increased hepatic resistance, the splanchnic vasculature is hyporesponsive, promoting the development of the hyperdynamic circulation that characterizes portal hypertension. Both liver fibrosis and portal hypertension represent important therapeutic challenges for the clinician, and there is accumulating evidence that RAS blockade may be beneficial in these circumstances. The present review outlines new aspects of the RAS and explores its role in the pathogenesis and treatment of liver fibrosis and portal hypertension.
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Zhou TB, Lin N, Liu YG, Qin YH, Shao MB, Peng DD. Association of ACE I/D gene polymorphism with vesicoureteral reflux susceptibility in children: a meta-analysis. J Renin Angiotensin Aldosterone Syst 2012; 13:273-81. [PMID: 22396489 DOI: 10.1177/1470320312437892] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- Tian-Biao Zhou
- Department of Pediatrics, The First Affiliated Hospital of GuangXi Medical University, NanNing, China
| | - Na Lin
- Department of Pediatrics, The Affiliated Hospital of Medical College of Youjiang for Nationalities, Baise, China
| | - Yun-Guang Liu
- Department of Pediatrics, The Affiliated Hospital of Medical College of Youjiang for Nationalities, Baise, China
| | - Yuan-Han Qin
- Department of Pediatrics, The First Affiliated Hospital of GuangXi Medical University, NanNing, China
| | - Ming-Bin Shao
- Department of Pediatrics, The First Affiliated Hospital of GuangXi Medical University, NanNing, China
| | - Dan-Dan Peng
- Department of Pediatrics, The First Affiliated Hospital of GuangXi Medical University, NanNing, China
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Albayrak M, Celebi H, Albayrak A, Sayilir A, Yesil Y, Balcik OS, Yokus O, Celik T. Elevated serum angiotensin converting enzyme levels as a reflection of bone marrow renin-angiotensin system activation in multiple myeloma. J Renin Angiotensin Aldosterone Syst 2012; 13:259-64. [PMID: 22345095 DOI: 10.1177/1470320312437070] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
INTRODUCTION Angiotensin converting enzyme (ACE) is a circulating enzyme that participates in the body's renin-angiotensin system (RAS) and is localized on the endothelial cell surface in the lung and other vascular beds. It catalyses the conversion of decapeptide angiotensin I to octapeptide angiotensin II. In the present study, we aimed to analyse the possible relationship between the levels of ACE in the context of RAS in multiple myeloma (MM) pathogenesis. MATERIALS AND METHODS The study was conducted on 25 MM patients (13 males, 12 females; median age 66 years, range 47-88) and 20 healthy controls. The clinical features of MM patients including demographics and laboratory findings were summarized. Serum ACE levels were measured by using commercially available kits. RESULTS The serum ACE levels of MM patients and controls were 32.60±20.26 and 15.35±6.47 respectively. Serum ACE levels were significantly higher in MM patients compared with control groups (p<0.001). CONCLUSIONS Being an important component of RAS, circulating ACE might be associated with clonal proliferation of malignant plasma cells in the bone marrow microenvironment. Identification of the pathobiological activity of the local RAS in MM would enlighten the biologic basis and clinical management of haematologic disorders.
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Affiliation(s)
- Murat Albayrak
- Diskapi Education and Research Hospital, Department of Haematology, Ankara, Turkey
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68
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Garg M, Angus PW, Burrell LM, Herath C, Gibson PR, Lubel JS. Review article: the pathophysiological roles of the renin-angiotensin system in the gastrointestinal tract. Aliment Pharmacol Ther 2012; 35:414-28. [PMID: 22221317 PMCID: PMC7159631 DOI: 10.1111/j.1365-2036.2011.04971.x] [Citation(s) in RCA: 112] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Revised: 11/29/2011] [Accepted: 12/13/2011] [Indexed: 02/06/2023]
Abstract
BACKGROUND The renin-angiotensin system (RAS) is a homeostatic pathway widely known to regulate cardiovascular and renal physiology; however, little is known about its influence in gastrointestinal tissues. AIM To elicit the anatomical distribution and physiological significance of the components of the RAS in the gastrointestinal tract. METHODS An extensive online literature review including Pubmed and Medline. RESULTS There is evidence for RAS involvement in gastrointestinal physiology and pathophysiology, with all the components required for autonomous regulation identified throughout the gastrointestinal tract. The RAS is implicated in the regulation of glucose, amino acid, fluid and electrolyte absorption and secretion, motility, inflammation, blood flow and possibly malignant disease within the gastrointestinal tract. Animal studies investigating the effects of RAS blockade in a range of conditions including inflammatory bowel disease, functional gut disorders, gastrointestinal malignancy and even intestinal ischaemia have been encouraging to date. Given the ready availability of drugs that modify the RAS and their excellent safety profile, an opportunity exists for investigation of their possible therapeutic role in a variety of human gastrointestinal diseases. CONCLUSIONS The gastrointestinal renin-angiotensin system appears to be intricately involved in a number of physiological processes, and provides a possible target for novel investigative and therapeutic approaches.
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Affiliation(s)
- M. Garg
- Department of Gastroenterology & HepatologyEastern HealthVic., Australia,Eastern Health Clinical SchoolMonash UniversityVic., Australia
| | - P. W. Angus
- Department of MedicineMelbourne UniversityVic., Australia,Gastroenterology and Liver Transplant UnitAustin HospitalVic., Australia
| | - L. M. Burrell
- Department of MedicineMelbourne UniversityVic., Australia
| | - C. Herath
- Department of MedicineMelbourne UniversityVic., Australia
| | - P. R. Gibson
- Department of Gastroenterology & HepatologyEastern HealthVic., Australia,Eastern Health Clinical SchoolMonash UniversityVic., Australia
| | - J. S. Lubel
- Department of Gastroenterology & HepatologyEastern HealthVic., Australia,Gastroenterology and Liver Transplant UnitAustin HospitalVic., Australia,Eastern Health Clinical SchoolMonash UniversityVic., Australia
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69
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Purnak T, Beyazit Y, Oztas E, Yesil Y, Efe C, Torun S, Celik T, Tenlik I, Kurt M, Ozaslan E. Serum angiotensin-converting enzyme level as a marker of fibrosis in patients with chronic hepatitis B. J Renin Angiotensin Aldosterone Syst 2012; 13:244-9. [PMID: 22277254 DOI: 10.1177/1470320311434241] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND and aims: Hepatitis B virus (HBV) infection is a public health problem and affects nearly 350 million people worldwide. The present study was conducted in order to investigate the role of circulating angiotensin-converting enzyme (ACE) in the context of renin-angiotensin-aldosterone in newly diagnosed chronic hepatitis B infection. Moreover the association between liver fibrosis and serum ACE levels was also investigated. MATERIALS AND METHODS The study was performed on 50 chronic hepatitis B (CHB) patients (24 males, 26 females; median age 39.4 years, range 18-63) and 20 healthy controls. The clinical features of CHB patients including demographics, laboratory and liver biopsy findings were summarized. Serum ACE levels were measured by using commercially available kits. RESULTS Serum median ACE levels were 48.4 (14-83) U/L and 26.2 (12-48) U/L for the CHB patients and controls, respectively. Serum ACE levels were significantly higher in patients with CHB compared with the control group (p<0.001). Twenty-two patients (44%) had advanced liver fibrosis (Ishak score >2) and 28 patients (56%) had mild liver fibrosis (Ishak score ≤ 2). Mean serum levels of ACE were significantly higher among patients with advanced fibrosis as compared with those without advanced fibrosis (60.3±14.2 U/L vs. 39.0±10.5 U/L, p<0.001). Receiver operating characteristic (ROC) curve analysis suggested that the optimum ACE level cut-off point for advanced fibrosis was 52.5 U/L (sensitivity: 81.8%, specificity: 82.1%, PPV 78.3%, NPV 85.2%, accuracy 82%, AUC: 0.890). CONCLUSIONS Our study showed that elevated circulating ACE levels are commonly observed in CHB patients. This finding was more prominent in patients with advanced fibrosis in liver. When evaluating a patient along with other parameters, the inclusion of ACE levels in the evaluation of CHB patients may grant additional prognostic information.
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Affiliation(s)
- Tugrul Purnak
- Department of Gastroenterology, Ankara Numune Education and Research Hospital, Ankara, Turkey.
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70
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Increased ACE in extrahepatic cholangiocarcinoma as a clue for activated RAS in biliary neoplasms. Clin Res Hepatol Gastroenterol 2011; 35:644-9. [PMID: 21802387 DOI: 10.1016/j.clinre.2011.06.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2011] [Revised: 05/23/2011] [Accepted: 06/20/2011] [Indexed: 02/04/2023]
Abstract
AIM Cholangiocarcinoma (CCA) is a primary neoplastic tumor of the epithelial lining of the biliary tree which carries a poor prognosis despite combined therapeutic strategies. Although the exact etiology remains obscure, it has been suggested that locally produced Angiotensin II (Ang II) in intrahepatic CCA tissues plays a key role in the proliferation and activation of CCA. In the present study, we aimed to analyze the relationship between the levels of circulating angiotensin converting enzyme (ACE), an important molecule of the renin-angiotensin system (RAS), and biliary disorders. PATIENTS AND METHODS The study group comprised 19 extrahepatic cholangiocarcinoma (EHCC) (16 patients with hilar, three patients with distal CCA), and 15 choledocolithiasis (CL) patients, with 15 controls. Median age of EHCC, CL and healthy controls were 67 (48-82), 65 (29-87) and 56 (23-74) respectively. ACE was measured by monitoring the alteration in absorbance at 340 nm of the hydrolysis of furylacrylolylphenylalanylglycylglycine (FAPGG) to FAP and GG on an analyzer. The ACE activity in the sample was determined by comparing the sample reaction rate to that obtained with the ACE calibrator. RESULTS Serum mean ACE levels were 56.6±27.4 U/L, 32.9±14.6 U/L and 28.6±10.6 U/L for patients with EHCC, CL and healthy controls, respectively. Serum ACE levels were significantly higher in patients with EHCC compared to CL and control groups. No significant differences with respect to ACE levels were observed between CL and control groups. CONCLUSION Circulating ACE in the context of RAS might be associated with EHCC development by creating a local environment enriched with cytokines and other growth factors that may promote cholangiocyte turnover.
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71
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Zhou TB, Qin YH, Ou C, Su LN, Lei FY, Huang WF, Zhao YJ, Pang YS. A meta-analysis of the association between angiotensin-converting enzyme insertion/deletion gene polymorphism and steroid-sensitive nephrotic syndrome in children. J Renin Angiotensin Aldosterone Syst 2011; 13:175-83. [PMID: 21946393 DOI: 10.1177/1470320311422579] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND AND OBJECTIVE Angiotensin-converting enzyme (ACE) insertion/deletion (I/D) gene polymorphism correlates with circulating and cellular ACE concentration. Association between ACE I/D gene polymorphism and steroid-sensitive nephrotic syndrome (SSNS) risk in children is still controversial. This meta-analysis was performed to evaluate the relation between ACE I/D gene polymorphism and SSNS susceptibility in children. METHODS The relevant investigations were screened from the search engines of PubMed, Cochrane Library and CBM-disc (China Biological Medicine Database) as of 1 March 2011, and eligible studies were synthesized using meta-analysis methods. RESULTS Ten studies were identified for the analysis of association between ACE I/D gene polymorphism and SSNS risk in children, including seven in Asians, one for Caucasians and two in Africans. There was no markedly positive association between D allele or DD genotype and SSNS susceptibility in Asians, Caucasians and Africans (D: Asians OR = 1.24, p = 0.28; Caucasians OR = 1.61, p = 0.15; Africans OR = 1.61, p = 0.53; DD: Asians OR = 1.72, p = 0.15; Caucasians OR = 1.39, p = 0.48; Africans OR = 1.80, p = 0.56). Furthermore, II homozygous seemed not to play a protective role against SSNS onset for Asians, Caucasians and Africans (Asians OR = 0.95, p = 0.85; Caucasians OR = 0.30, p = 0.11; Africans OR = 0.60, p = 0.65). CONCLUSIONS There was no association between ACE I/D gene polymorphism and SSNS susceptibility in Asians, Caucasians and Africans. However, the conclusions for Caucasians and Africans were less powerful.
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Affiliation(s)
- Tian-Biao Zhou
- Department of Pediatrics, The First Affiliated Hospital of GuangXi Medical University, NanNing, China.
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72
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Zhou TB, Ou C, Qin YH, Su LN, Lei FY, Huang WF, Zhao YJ, Pang YS, Yang KP. Association of angiotensin converting enzyme insertion/deletion gene polymorphism with idiopathic nephrotic syndrome susceptibility in children: a meta-analysis. J Renin Angiotensin Aldosterone Syst 2011; 12:601-10. [PMID: 21946394 DOI: 10.1177/1470320311422578] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Background and objective: Angiotensin converting enzyme (ACE) gene contains either an insertion (I) allele or a deletion (D) allele forming three potential genotypes: II, ID and DD. The D allele or DD genotype has been reported to be associated with higher plasma ACE level. An assessment of the association between ACE I/D gene polymorphism and idiopathic nephrotic syndrome (INS) susceptibility in children is still controversial. This meta-analysis was performed to evaluate the association between ACE I/D gene polymorphism and the onset of INS. Method: A predefined literature search and selection of eligible relevant studies were performed to collect data from electronic databases, and eligible investigations were synthesized using the meta-analysis method. Results: Nine investigations were identified for the analysis of association between ACE I/D gene polymorphism and INS risk in children, including six in Asians, one study for Caucasians and two for Africans. There was positive association between D allele or DD genotype and INS susceptibility in Asians (OR = 1.75, p = 0.01; OR = 2.01, p = 0.02), but not for Caucasian children and Africans (for Caucasians, D: OR=1.35, p = 0.27, DD: OR = 0.95, p = 0.91; for Africans, D: OR = 1.70, p = 0.56, DD: OR = 1.60, p = 0.73). Furthermore, II homozygous seemed to play a positive role against INS onset for Asians (OR = 0.59, p = 0.02), but the link between II genotype and INS risk was not observed in Caucasian children and Africans (Caucasians: OR = 0.31, p = 0.06; Africans: OR = 0.50, p = 0.59). Conclusions: D allele and DD homozygous might become significant genetic molecular markers for INS susceptibility in Asian children, but the association was not observed in Caucasians or Africans. However, the conclusion from our study cannot be sustained and more investigations on larger sample in different populations are required to further clarify the role of D allele or DD homozygous in the onset of INS in difference races.
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Affiliation(s)
- Tian-Biao Zhou
- Department of Pediatrics, The First Affiliated Hospital of GuangXi Medical University, NanNing, China
| | - Chao Ou
- Department of Experimental Pathology, The Affiliated Tumor Hospital of Guangxi Medical University, Nanning, China
| | - Yuan-Han Qin
- Department of Pediatrics, The First Affiliated Hospital of GuangXi Medical University, NanNing, China
| | - Li-Na Su
- Department of Pediatrics, The First Affiliated Hospital of GuangXi Medical University, NanNing, China
| | - Feng-Ying Lei
- Department of Pediatrics, The First Affiliated Hospital of GuangXi Medical University, NanNing, China
| | - Wei-Fang Huang
- Department of Pediatrics, The First Affiliated Hospital of GuangXi Medical University, NanNing, China
| | - Yan-Jun Zhao
- Department of Pediatrics, The First Affiliated Hospital of GuangXi Medical University, NanNing, China
| | - Yu-Sheng Pang
- Department of Pediatrics, The First Affiliated Hospital of GuangXi Medical University, NanNing, China
| | - Kun-Peng Yang
- Department of Internal Medicine, Township Health Centers of ShilLing in LongQuan district, ChengDu, China
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73
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Watanabe T. [108th Scientific Meeting of The Japanese Society of Internal Medicine: symposium: 3. The interaction between kidney and other organs; what should physicians know about it? (3) Physiological and pathophysiological interaction between liver and kidney]. NIHON NAIKA GAKKAI ZASSHI. THE JOURNAL OF THE JAPANESE SOCIETY OF INTERNAL MEDICINE 2011; 100:2544-2551. [PMID: 22117349 DOI: 10.2169/naika.100.2544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Affiliation(s)
- Tsuyoshi Watanabe
- Department of Nephrology, Hypertension Diabetology, Endocrinology and Metabolic, Fukushima Medical University School of Medicine, Japan
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74
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Hayden MR, Sowers KM, Pulakat L, Joginpally T, Krueger B, Whaley-Connell A, Sowers JR. Possible Mechanisms of Local Tissue Renin-Angiotensin System Activation in the Cardiorenal Metabolic Syndrome and Type 2 Diabetes Mellitus. Cardiorenal Med 2011; 1:193-210. [PMID: 22096455 DOI: 10.1159/000329926] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Accepted: 06/07/2011] [Indexed: 01/08/2023] Open
Abstract
The role of local tissue renin-angiotensin system (tRAS) activation in the cardiorenal metabolic syndrome (CRS) and type 2 diabetes mellitus (T2DM) is not well understood. To this point, we posit that early redox stress-mediated injury to tissues and organs via accumulation of excessive reactive oxygen species (ROS) and associated wound healing responses might serve as a paradigm to better understand how tRAS is involved. There are at least five common categories responsible for generating ROS that may result in a positive feedback ROS-tRAS axis. These mechanisms include metabolic substrate excess, hormonal excess, hypoxia-ischemia/reperfusion, trauma, and inflammation. Because ROS are toxic to proteins, lipids, and nucleic acids they may be the primary instigator, serving as the injury nidus to initiate the wound healing process. Insulin resistance is central to the development of the CRS and T2DM, and there are now thought to be four major organ systems important in their development. In states of overnutrition and tRAS activation, adipose tissue, skeletal muscle (SkM), islet tissues, and liver (the quadrumvirate) are individually and synergistically related to the development of insulin resistance, CRS, and T2DM. The obesity epidemic is thought to be the driving force behind the CRS and T2DM, which results in the impairment of multiple end-organs, including the cardiovascular system, pancreas, kidney, retina, liver, adipose tissue, SkM, and nervous system. A better understanding of the complex mechanisms leading to local tRAS activation and increases in tissue ROS may lead to new therapies emphasizing global risk reduction of ROS resulting in decreased morbidity and mortality.
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Affiliation(s)
- Melvin R Hayden
- Department of Internal Medicine, University of Missouri-Columbia School of Medicine, Columbia, Mo., USA
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75
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Zhou TB, Qin YH, Su LN, Lei FY, Huang WF, Zhao YJ, Pang YS. Insertion/Deletion (I/D) Polymorphism of Angiotensin-Converting Enzyme Gene in Steroid-Resistant Nephrotic Syndrome for Children: A Genetic Association Study and Meta-analysis. Ren Fail 2011; 33:741-8. [PMID: 21787164 DOI: 10.3109/0886022x.2011.589954] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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76
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Clayton D, Hanchapola I, Hausler N, Unabia S, Lew RA, Widdop RE, Smith AI, Perlmutter P, Aguilar MI. β-Amino acid substitution to investigate the recognition of angiotensin II (AngII) by angiotensin converting enzyme 2 (ACE2). J Mol Recognit 2011; 24:235-44. [PMID: 20549604 DOI: 10.1002/jmr.1041] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
In spite of the important role of angiotensin converting enzyme 2 (ACE2) in the cardiovascular system, little is known about the substrate structural requirements of the AngII-ACE2 interaction. Here we investigate how changes in angiotensin II (AngII) structure affect binding and cleavage by ACE2. A series of C3 β-amino acid AngII analogs were generated and their secondary structure, ACE2 inhibition, and proteolytic stability assessed by circular dichroism (CD), quenched fluorescence substrate (QFS) assay, and LC-MS analysis, respectively. The β-amino acid-substituted AngII analogs showed differences in secondary structure, ACE2 binding and proteolytic stability. In particular, three different subsets of structure-activity profiles were observed corresponding to substitutions in the N-terminus, the central region and the C-terminal region of AngII. The results show that β-substitution can dramatically alter the structure of AngII and changes in structure correlated with ACE2 inhibition and/or substrate cleavage. β-amino acid substitution in the N-terminal region of AngII caused little change in structure or substrate cleavage, while substitution in the central region of AngII lead to increased β-turn structure and enhanced substrate cleavage. β-amino acid substitution in the C-terminal region significantly diminished both secondary structure and proteolytic processing by ACE2. The β-AngII analogs with enhanced or decreased proteolytic stability have potential application for therapeutic intervention in cardiovascular disease.
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Affiliation(s)
- Daniel Clayton
- Biochemistry & Molecular Biology, Monash University, Clayton, Victoria 3800, Australia
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77
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Zhou TB, Qin YH, Su LN, Lei FY, Huang WF, Zhao YJ, Pang YS, Yang KP. The association between angiotensin-converting enzyme insertion/deletion gene variant and risk of focal segmental glomerulosclerosis: a systematic review and meta-analysis. J Renin Angiotensin Aldosterone Syst 2011; 12:624-33. [PMID: 21652690 DOI: 10.1177/1470320311410584] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND AND OBJECTIVE The association of the angiotensin-converting enzyme (ACE) insertion/deletion (I/D) gene polymorphism with the risk of focal segmental glomerulosclerosis (FSGS) is still controversial. A meta-analysis was performed to evaluate the association between ACE I/D gene polymorphism and FSGS susceptibility. METHOD We performed a predefined literature search and selection of eligible relevant studies to collect data from electronic databases. RESULTS In total, 12 articles were identified for the analysis of the association between ACE I/D gene polymorphism and FSGS risk. One report included an investigation in Arab and Jewish populations separately. Thus, there were seven reports in Asians, two in Caucasians, one in Africans, two in Arabs and one in Jews. In Asians, there was a markedly positive association between the D allele or DD genotype and FSGS susceptibility (p = 0.008; p = 0.002), and the II genotype may play a protective role against FSGS onset (p = 0.002). However, a link between ACE I/D gene polymorphism and FSGS risk was not found in Caucasians, Africans, Arabs or Jews (Caucasians: D: p = 0.11, DD: p = 0.19, II: p = 0.70; Africans: D: p = 0.40, DD: p = 0.49, II: p = 0.61; Arabs: D: p = 0.34, DD: p = 0.10, II: p = 0.42; Jews: D: p = 0.90, DD: p = 0.97, II: p = 0.83). CONCLUSION The D allele or DD homozygosity may become a significant genetic molecular marker for the onset of FSGS in Asians, but not for Caucasians, Africans, Arabs or Jews.
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Affiliation(s)
- Tian-Biao Zhou
- Department of Pediatrics, The First Affiliated Hospital of GuangXi Medical University, NanNing, China.
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Zhou TB, Qin YH, Su LN, Lei FY, Huang WF, Zhao YJ. ACE I/D gene polymorphism can't predict the steroid responsiveness in Asian children with idiopathic nephrotic syndrome: a meta-analysis. PLoS One 2011; 6:e19599. [PMID: 21611163 PMCID: PMC3097181 DOI: 10.1371/journal.pone.0019599] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2010] [Accepted: 04/01/2011] [Indexed: 01/08/2023] Open
Abstract
Background The results from the published studies on the association between
angiotensin-converting enzyme (ACE) insertion/deletion (I/D) gene
polymorphism and the treatment response to steroid in Asian children with
idiopathic nephrotic syndrome (INS) is still conflicting. This meta-analysis
was performed to evaluate the relation between ACE I/D gene polymorphism and
treatment response to steroid in Asian children and to explore whether ACE D
allele or DD genotype could become a predictive marker for steroid
responsiveness. Methodology/Principal Findings Association studies were identified from the databases of PubMed, Embase,
Cochrane Library and CBM-disc (China Biological Medicine Database) as of
September 1, 2010, and eligible investigations were synthesized using
meta-analysis method. Five investigations were identified for the analysis
of association between ACE I/D gene polymorphism and steroid-resistant
nephrotic syndrome (SRNS) risk in Asian children and seven studies were
included to explore the relationship between ACE I/D gene polymorphism and
steroid-sensitive nephrotic syndrome (SSNS) susceptibility. Five
investigations were recruited to explore the difference of ACE I/D gene
distribution between SRNS and SSNS. There was no a markedly association
between D allele or DD genotype and SRNS susceptibility or SSNS risk, and
the gene distribution differences of ACE between SRNS and SSNS were not
statistically significant. II genotype might play a positive role against
SRNS onset but not for SSNS (OR = 0.51,
P = 0.02;
OR = 0.95,
P = 0.85; respectively), however, the
result for the association of II genotype with SRNS risk was not stable. Conclusions/Significance Our results indicate that D allele or DD homozygous can't become a
significant genetic molecular marker to predict the treatment response to
steroid in Asian children with INS.
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Affiliation(s)
- Tian-Biao Zhou
- Department of Pediatrics, The First Affiliated Hospital of GuangXi
Medical University, NanNing, China
| | - Yuan-Han Qin
- Department of Pediatrics, The First Affiliated Hospital of GuangXi
Medical University, NanNing, China
- * E-mail:
| | - Li-Na Su
- Department of Pediatrics, The First Affiliated Hospital of GuangXi
Medical University, NanNing, China
| | - Feng-Ying Lei
- Department of Pediatrics, The First Affiliated Hospital of GuangXi
Medical University, NanNing, China
| | - Wei-Fang Huang
- Department of Pediatrics, The First Affiliated Hospital of GuangXi
Medical University, NanNing, China
| | - Yan-Jun Zhao
- Department of Pediatrics, The First Affiliated Hospital of GuangXi
Medical University, NanNing, China
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79
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Zhou TB, Qin YH, Su LN, Lei FY, Huang WF, Zhao YJ. Relationship between Angiotensin-Converting Enzyme Insertion/Deletion Gene Polymorphism and Susceptibility of Minimal Change Nephrotic Syndrome: A Meta-Analysis. Int J Nephrol 2011; 2011:360357. [PMID: 21660286 PMCID: PMC3106969 DOI: 10.4061/2011/360357] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2010] [Revised: 02/23/2011] [Accepted: 03/08/2011] [Indexed: 11/20/2022] Open
Abstract
Aim. This meta-analysis was performed to evaluate the association between ACE I/D gene polymorphism and MCNS susceptibility.
Method. A predefined literature search and selection of eligible relevant studies were performed to collect the data from electronic databases.
Results. Six articles were identified for the analysis of association between ACE I/D gene polymorphism and MCNS risk, including 4 for Asians, one in Caucasian population and one for Africans. There was a markedly positive association between D allele or DD genotype and MCNS susceptibility in Asians (D: P = .01, DD: P = .02), but not for Caucasians and Africans (Caucasians: D: P = .16, DD: P = .98;
Africans: D: P = .81, DD: P = .49). Furthermore, the II genotype seemed not to play a protective role against MCNS risk for Asians, Caucasians and Africans (P = .12, P = .09, P = .76, resp.). Interestingly, there was also significant association between ACE I/D gene polymorphism and MCNS susceptibility in overall populations (D: P = .007, DD: P = .04, II: P = .03).
Conclusion. D allele or DD genotype might be a significant genetic molecular marker for MCNS susceptibility in Asians and overall populations, but not for Caucasians and Africans. More larger and rigorous genetic epidemiological investigations are required to further explore this association.
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Affiliation(s)
- Tian-Biao Zhou
- Department of Pediatrics, The First Affiliated Hospital of Guangxi Medical University, Nanning 530021, China
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80
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Munshi MK, Uddin MN, Glaser SS. The role of the renin-angiotensin system in liver fibrosis. Exp Biol Med (Maywood) 2011; 236:557-66. [PMID: 21508249 DOI: 10.1258/ebm.2011.010375] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Hepatic fibrosis, which is characterized by progressive inflammation and deposition of extracellular matrix components, is a common response to chronic liver disease. Hepatic fibrogenesis is a dynamic process that involves several liver cell types including hepatic stellate cells and Kupffer cells. In addition, recent evidence indicates that bile duct epithelial cells (i.e. cholangiocytes) also participate in the progression of biliary fibrosis that is observed during chronic cholestatic liver diseases, such as primary sclerosing cholangitis. To date, there are no effective treatments for hepatic fibrosis. Several recent studies have demonstrated that the renin-angiotensin system (RAS) plays a key role in hepatic fibrosis. Therapies targeting the RAS may represent a promising paradigm for the prevention and treatment of hepatic fibrosis in the setting of chronic liver disease. In this review, we provide a comprehensive update on the role of RAS in the pathogenesis of hepatic fibrosis in both animal models and human studies. We will discuss the profibrotic mechanisms activated by the RAS and the cell types involved. Studies that have utilized angiotensin receptor blockers (ARBs) and angiotensin-converting enzyme (ACE) inhibitors to modulate the RAS in order to ameliorate hepatic fibrosis will also be discussed. Although the cumulative evidence supports the potential for the use of ARBs and ACE inhibitors as treatment for hepatic fibrosis, extensive studies of the effectiveness of RAS therapeutics are necessary in patients with chronic liver disease.
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Affiliation(s)
- M Kamruzzman Munshi
- Department of Medicine, Division of Gastroenterology, Scott & White Hospital and Texas A&M Health Science Center, College of Medicine, Temple, 76504, USA
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Ekor M, Odewabi AO, Kale OE, Oritogun KS, Adesanoye OA, Bamidele TO. Pharmacologic inhibition of the renin-angiotensin system did not attenuate hepatic toxicity induced by carbon tetrachloride in rats. Hum Exp Toxicol 2011; 30:1840-8. [DOI: 10.1177/0960327111401051] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The renin-angiotensin system (RAS) subserves vital physiological functions and also implicated in certain pathological states. Modulation of this system has been proposed in recent studies to be a promising strategy in treating liver fibrosis. We investigated the effect of the pharmacologic inhibition of RAS with angiotensin-converting enzyme inhibitor or angiotensin receptor blocker in CCl4-induced liver injury with a view to ascertaining the chemopreventive benefit. Fifty-six Wistar albino rats were divided into eight experimental groups of seven rats/group. Groups 1–4 received normal saline (10 ml/kg), enalapril (0.6 mg/kg), losartan (1.4 mg/kg) and CCl4 (80 mg/kg), respectively. Groups 5–8 were pretreated with enalapril (0.3 mg/kg), enalapril (0.6 mg/kg), losartan (0.7 mg/kg) and losartan (1.4 mg/kg) 1 hour before CCl4 administration. Experiment lasted 11 days and dosing was via oral route. Rats were killed 24 hours after the last treatment. Serum activities of alkaline phosphatase, aspartate and alanine aminotransferases increased significantly ( p < 0.05) by 46.0%, 90.6% and 122.3%, respectively, with severe hepatic centrilobular necrosis, fatty infiltration and increase in liver weight ( p < 0.05) in the CCl4-treated rats. Enalapril (0.6 mg/kg) and losartan (1.4 mg/kg) significantly ( p < 0.05) increased aspartate aminotransferase activity by 37.0% and 94.7% and produced mild centrilobular and periportal hepatic necrosis, respectively, with enalapril significantly ( p < 0.05) increasing liver weight. Serum total cholesterol, triglyceride, albumin and total protein did not change significantly in these rats. Also, glutathione, malondialdehyde and uric acid levels were not significantly altered. Enalapril and losartan failed to attenuate liver injury associated with CCl4 treatment. Although both drugs did not significantly alter serum biochemistry in the CCl4-treated rats, they however produced slight elevations in biomarkers of liver function and appear to worsen liver histopathology. Overall, the chemopreventive benefits of RAS inhibitors in liver disease remain doubtful and should be used with caution during hepatic dysfunction.
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Affiliation(s)
- Martins Ekor
- Department of Chemical Sciences, Redeemer’s University, Ogun State, Nigeria
- Department of Pharmacology, Olabisi Onabanjo University, Ogun State, Nigeria
| | - Adesina O Odewabi
- Department of Chemical Pathology, Olabisi Onabanjo University Teaching Hospital, Ogun State, Nigeria
| | - Oluwafemi E Kale
- Department of Pharmacology, Olabisi Onabanjo University, Ogun State, Nigeria
| | - Kolawole S Oritogun
- Biostatistics Unit, Department of Medical Microbiology & Parasitology, Olabisi Onabanjo University, Ogun State, Nigeria
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82
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Abstract
The gastrointestinal (GI) tract is fundamental for the intake of fluid and electrolytes and accommodates a large proportion of bodily hemodynamics and host defence systems. Despite that the renin-angiotensin system (RAS) is a prominent regulatory system for fluid and electrolyte homeostasis its impact on GI physiology is only little explored. Recent data indicate that RAS is well expressed and active in the GI tract although exact physiological roles are to be settled. There are several reports showing influences by RAS and its key mediator angiotensin II (AngII) on intestinal epithelial fluid and electrolyte transport and data are accumulating, suggesting involvement in GI mucosal inflammation and carcinogenesis. Of particular interest is the increasing amount of experimental support for the involvement of AngII formation and actions via the AngII subtype 1 (AT1) receptor in the pathogenesis and treatment of inflammatory bowel disease. The picture of RAS in the GI tract is, however, far from complete. Because RAS is an important application area for reno-cardiovascular diseases, a number of pharmacological agents as well as research technologies already exist and can in the future be used for GI research. A marked expansion of knowledge concerning the role of RAS in GI physiology and pathophysiology is to be expected.
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Affiliation(s)
- L Fändriks
- Department of Gastrosurgical Research and Education, Institute of Clinical Sciences, University of Gothenburg, Sweden.
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83
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Satapathy SK, Charlton MR. Posttransplant metabolic syndrome: new evidence of an epidemic and recommendations for management. Liver Transpl 2011; 17:1-6. [PMID: 21254337 DOI: 10.1002/lt.22222] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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84
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Liu DG, Wang Y. Advances in understanding the role of the UII/UT system in the pathogenesis of portal hypertension. Shijie Huaren Xiaohua Zazhi 2010; 18:3332-3337. [DOI: 10.11569/wcjd.v18.i31.3332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Urotensin II (UII), a vasoactive peptide with structural similarity to somatostatin, is the most potent vasoconstrictor known in systemic resistance vessels and has multiple biological effects related to a variety of human diseases. Numerous studies have found that UII and its receptor (UT) play an important role in the pathogenesis of portal hypertension. This paper reviews the recent advances in understanding the role of the UII/UT system in the pathogenesis of portal hypertension.
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85
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Chen YW, Liu BW, Zhang YJ, Chen YW, Dong GF, Ding XD, Xu LM, Pat B, Fan JG, Li DG. Preservation of basal AcSDKP attenuates carbon tetrachloride-induced fibrosis in the rat liver. J Hepatol 2010; 53:528-36. [PMID: 20646773 DOI: 10.1016/j.jhep.2010.03.027] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2009] [Revised: 03/15/2010] [Accepted: 03/31/2010] [Indexed: 01/22/2023]
Abstract
BACKGROUND & AIMS N-acetyl-seryl-aspartyl-lysyl-proline (AcSDKP) is an endogenous tetrapeptide which has antifibrogenic effects at physiological concentrations in various tissues. AcSDKP is produced locally in the liver, however, little is known about its biological effect in this organ. We hypothesize that basal levels of endogenous AcSDKP decrease during the development of liver fibrosis and preservation of basal AcSDKP attenuates liver fibrosis. METHODS Endogenous levels of AcSDKP in the liver were measured by enzyme immunoassay after 2, 6, and 10 weeks of carbon tetrachloride (CCl(4))-induced liver fibrosis in rats. Subcutaneous osmotic pump infusion of vehicle or AcSDKP (800 microg/kg/day) was administered to CCl(4)-treated rats for 8 weeks to study the effect of exogenous AcSDKP on liver fibrosis. The effect of AcSDKP on profibrogenic properties of hepatic stellate cells was studied in vitro. RESULTS Endogenous AcSDKP was significantly decreased in the liver of CCl(4)-treated rats. Chronic AcSDKP infusion preserved basal levels of AcSDKP and reduced liver injury, inflammation, fibrosis, and profibrogenic transforming growth factor-beta signaling. This was demonstrated by decreased aminotransferase serum levels, CD45 positive cells, collagen accumulation, alpha-smooth muscle actin positivity, transforming growth factor-beta1, phosphorylated Smad2/3 protein, increased bone morphogenetic protein-7, and phosphorylated Smad1/5/8. Further, AcSDKP exerts antifibrogenic effects on hepatic stellate cells (HSCs) by downregulation of HSC activation in vitro. CONCLUSIONS Maintaining physiological levels of AcSDKP is critical in negatively regulating the development of fibrosis in chronic liver injury. Preservation of AcSDKP may be a useful therapeutic approach in the management of liver fibrosis.
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Affiliation(s)
- Yuan-Wen Chen
- Department of Gastroenterology, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
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86
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Abstract
Primary sclerosing cholangitis is a cholestatic liver disease characterized by inflammation and fibrosis of intra-/extrahepatic bile ducts, leading to multifocal strictures. Primary sclerosing cholangitis exhibits a progressive course resulting in cirrhosis and the need for liver transplantation over a median period of 12 years. The disease is frequently associated with inflammatory bowel disease and carries an increased risk of colorectal cancer and cholangiocarcinoma. Despite extensive research, there is currently no effective medical treatment. Multiple drugs are shown to be ineffective in halting disease progression, including ursodeoxycholic acid, the most widely evaluated drug. High-dose ursodeoxycholic acid (28-30 mg/kg/day) was recently shown to increase the adverse events rate. Endoscopic or radiological dilatation of a 'dominant' stricture may lead to symptomatic and biochemical improvement. However, liver transplantation is the only life-prolonging treatment for patients with end-stage disease. Studies with promising drugs, such as antibiotics, antifibrotic agents and bile acid derivatives, are eagerly awaited.
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Affiliation(s)
- Emmanouil Sinakos
- Division of Gastroenterology and Hepatology, Mayo Clinic, 200 First Street, SW, Rochester, MN 55905, USA
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87
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Ulmasov B, Xu Z, Talkad V, Oshima K, Neuschwander-Tetri BA. Angiotensin II signaling through the AT1a and AT1b receptors does not have a role in the development of cerulein-induced chronic pancreatitis in the mouse. Am J Physiol Gastrointest Liver Physiol 2010; 299:G70-80. [PMID: 20413721 PMCID: PMC7199229 DOI: 10.1152/ajpgi.00006.2010] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The intraorgan renin-angiotensin system (RAS) plays an important role in the pathophysiology of a variety of diseases and has been implicated in fibrogenesis. The role of RAS in the development of chronic pancreatitis is not well established. The blockade of RAS in rat models with angiotensin-converting enzyme inhibitors (ACEi) or angiotensin receptor 1 (AT1) blockers (ARBs) mostly have reduced pancreatic inflammation and fibrosis with a few exceptions. At the same time, the use of ACEi and ARBs in humans is associated with a modest risk of acute pancreatitis. The aim of this study was to elucidate the effect of the AT1 signaling pathway in the development of pancreatitis using AT1a- and AT1b-deficient mice as well as the ARB losartan. Chronic pancreatitis was induced by repetitive cerulein administration in C57BL/6J wild-type (WT) and AT1a- and AT1b-deficient mice (AT1a-/- and AT1b-/-), and pancreatic injury was assessed at day 10. Pancreatic weight of cerulein treated groups was significantly reduced. There was severe parenchymal atrophy and fibrosis assessed by histological examination. Fibrosis was accompanied by activation of pancreatic stellate cells (PSC) evaluated by Western blot analysis for alpha-smooth muscle actin. No differences were seen between cerulein-treated WT, AT1a-/- , AT1b-/- mice, or losartan treated-WT mice with regards to morphological or molecular alterations induced by cerulein. Our results demonstrate that AT1a and AT1b receptor pathways do not seem to be essential for the development of pancreatitis in the mouse model of pancreatitis induced by repetitive cerulein injury.
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Affiliation(s)
| | - Zekuan Xu
- 3Pathology, Saint Louis University School of Medicine, St. Louis, Missouri;
| | | | - Kiyoko Oshima
- 2Department of General Surgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
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88
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Watt KDS, Charlton MR. Metabolic syndrome and liver transplantation: a review and guide to management. J Hepatol 2010; 53:199-206. [PMID: 20451282 DOI: 10.1016/j.jhep.2010.01.040] [Citation(s) in RCA: 142] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2009] [Revised: 01/06/2010] [Accepted: 01/09/2010] [Indexed: 12/15/2022]
Abstract
Metabolic syndrome is common among liver transplant recipients before and after transplantation. The components of metabolic syndrome are often exacerbated in the post-transplant period by transplant specific factors, such as immunosuppression, and are strong predictors of patient morbidity and mortality. Many aspects of the metabolic syndrome are modifiable. Early recognition, prevention and treatment of post-transplant hypertension, obesity, dyslipidemia and diabetes may impact long-term post-transplant survival. Further study into the prevention and management of these issues in the transplant patient are needed.
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Affiliation(s)
- Kymberly D S Watt
- Department of Gastroenterology and Hepatology, Mayo Clinic and Foundation, MN, USA
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89
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Abstract
The concept of a circulating RAS is well established and known to play an endocrine role in the regulation of fluid homeostasis (see Section 4.1, Chapter 4). However, it is more appropriate to view the RAS in the contemporary notion as an “angiotensin-generating system”, which consists of angiotensinogen, angiotensin-generating enzymes, and angiotensins, as well as their receptors. Some RASs can be termed as “complete”, having renin and ACE involved in the biosynthesis of angiotensin II peptide, i.e. in a renin and/or ACE-dependent manner which is exemplified in the circulating RAS. On the other hand, some RAS can be termed as “partial”, having alternate enzymes to renin and ACE, such as chymase and ACE2 (see Section 4.3, Chapter 4) available for the generation of angiotensin II and other bioactive angiotensin peptides in the biosynthetic cascade, i.e. in a renin and/or ACE-independent manner. Complete vs. partial RASs can be exemplified in the so-called intrinsic angiotensin-generating system or local RAS; for example, a local and functional RAS with renin and ACE-dependent but a renin-independent pathway have been indentified in the pancreas and carotid body, respectively. In the past two decades, local RASs have gained increasing recognition especially with regards to their clinical importance. Distinct from the circulating RAS, these functional local RASs exist in such diverse tissues and organs as the pancreas, liver, intestine, heart, kidney, vasculature, carotid body, and adipose, as well as the nervous, reproductive, and digestive systems. Taken into previous findings from our laboratory and others together, Table 5.1 is a summary of some recently identified local RASs in various levels of tissues and organs.
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Affiliation(s)
- Po Sing Leung
- School of Biomedical Sciences Faculty of Medicine The Chinese University of Hong Kong, Shatin Hong Kong, China
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90
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Lugo-Baruqui A, Muñoz-Valle JF, Arévalo-Gallegos S, Armendáriz-Borunda J. Role of angiotensin II in liver fibrosis-induced portal hypertension and therapeutic implications. Hepatol Res 2010; 40:95-104. [PMID: 19737316 DOI: 10.1111/j.1872-034x.2009.00581.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Angiotensin II (AT-II) is a peptide that plays an important role in the renin-angiotensin-aldosterone (RAA) system. Traditionally, the RAA system has been related with states of systemic hypertension and hypoperfusion as a counterbalance mechanism. Recently, AT-II has been studied for its properties in the process of fibrosis in several organs, especially in the liver. AT-II is capable to stimulate the activated hepatic stellate cells, which increase expression of profibrogenic molecules like tumor growth factor-beta, tissue inhibitor of metalloproteinase-1 and collagen I, among others. At the same time, AT-II is implied in the hemodynamic balance of cirrhosis and portal hypertension. Due to its profibrogenic and vasoactive properties, blockade of AT-II actions constitutes an important therapeutic target to inhibit fibrotic processes and reduction of risk of complications of portal hypertension as well. Some drugs like angiotensin-converting enzyme inhibitors or the angiotensin II receptor blockers have been studied as alternatives for the treatment of patients with cirrhosis with promising results. Nonetheless, additional research is required in order to consider these drugs as a part of the integral treatment of the patient with cirrhosis and portal hypertension.
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Affiliation(s)
- Alejandro Lugo-Baruqui
- Institute of Molecular Biology in Medicine, Department of Molecular Biology and Genomics, CUCS
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91
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Ferrario CM, Ahmad S, Joyner J, Varagic J. Advances in the renin angiotensin system focus on angiotensin-converting enzyme 2 and angiotensin-(1-7). ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2010; 59:197-233. [PMID: 20933203 PMCID: PMC5863743 DOI: 10.1016/s1054-3589(10)59007-0] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The contribution of the renin angiotensin system to physiology and pathology is undergoing a rapid reconsideration of its mechanisms from emerging new concepts implicating angiotensin-converting enzyme 2 and angiotensin-(1-7) as new elements negatively influencing the vasoconstrictor, trophic, and pro-inflammatory actions of angiotensin II. This component of the system acts to oppose the vasoconstrictor and proliferative effects on angiotensin II through signaling mechanisms mediated by the mas receptor. In addition, a reduced expression of the vasodepressor axis composed by angiotensin-converting enzyme 2 and angiotensin-(1-7) may contribute to the expression of essential hypertension, the remodeling of heart and renal function associated with this disease, and even the physiology of pregnancy and the development of eclampsia.
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Affiliation(s)
- Carlos M Ferrario
- Hypertension and Vascular Disease Research Center, Wake Forest University School of Medicine, Winston Salem, North Carolina, USA
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92
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Trauner M, Arrese M, Wagner M. Fatty liver and lipotoxicity. Biochim Biophys Acta Mol Cell Biol Lipids 2009; 1801:299-310. [PMID: 19857603 DOI: 10.1016/j.bbalip.2009.10.007] [Citation(s) in RCA: 209] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2009] [Revised: 10/15/2009] [Accepted: 10/15/2009] [Indexed: 02/08/2023]
Abstract
Fatty liver disease comprises a spectrum ranging from simple steatosis to steatohepatitis which can progress to liver cirrhosis and hepatocellular cancer. Hepatic lipotoxicity may ensue when the hepatic capacity to utilize, store and export fatty acids (FA) as triglycerides is overwhelmed. Additional mechanisms of hepatic lipotoxicity include abnormal FA oxidation with formation of reactive oxygen species, disturbances in cellular membrane FA and phospholipid composition, alterations of cholesterol content and ceramide signalling. Lipotoxicity is a key factor for the progression of fatty liver disease by inducing hepatocellular death, activating Kupffer cells and an inflammatory response, impairing hepatic insulin signalling resulting in insulin resistance, and activation of a fibrogenic response in hepatic stellate cells that can ultimately lead to cirrhosis. Therefore, the concept of hepatic lipotoxicity should be considered in future therapeutic concepts for fatty liver disease.
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Affiliation(s)
- Michael Trauner
- Laboratory of Experimental and Molecular Hepatology, Division of Gastroenterology and Hepatology, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036 Graz, Austria.
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93
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Herath CB, Lubel JS, Jia Z, Velkoska E, Casley D, Brown L, Tikellis C, Burrell LM, Angus PW. Portal pressure responses and angiotensin peptide production in rat liver are determined by relative activity of ACE and ACE2. Am J Physiol Gastrointest Liver Physiol 2009; 297:G98-G106. [PMID: 19389807 PMCID: PMC2711749 DOI: 10.1152/ajpgi.00045.2009] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Angiotensin converting enzyme (ACE) 2 activity and angiotensin-(1-7) [Ang-(1-7)] levels are increased in experimental cirrhosis; however, the pathways of hepatic Ang-(1-7) production have not been studied. This study investigated the role of ACE2, ACE, and neutral endopeptidase (NEP) in the hepatic formation of Ang-(1-7) from angiotensin I (Ang I) and Ang II and their effects on portal resistance. Ang I or Ang II were administered to rat bile duct ligated (BDL) and control livers alone and in combination with the ACE inhibitor lisinopril, the ACE and NEP inhibitor omapatrilat, or the ACE2 inhibitor MLN4760 (n = 5 per group). BDL markedly upregulated ACE, ACE2, and NEP. Ang-(1-7) was produced from Ang II in healthy and in BDL livers and was increased following ACE inhibition and decreased by ACE2 inhibition. In contrast, Ang-(1-7) production from Ang I was minimal and not affected by ACE or NEP inhibition. Surprisingly, ACE2 inhibition in BDLs dramatically increased Ang-(1-7) production from Ang I, an effect abolished by ACE2/NEP inhibition. Ang II and Ang I induced greater portal pressure increases in BDL livers than controls. The effects of Ang I were closely correlated with Ang II production and were strongly attenuated by both ACE and ACE/NEP inhibition. These findings show that the major substrate for hepatic production of Ang-(1-7) is Ang II and this is catalyzed by ACE2. Ang I is largely converted to Ang II by ACE, and net conversion of Ang I to Ang-(1-7) is small. NEP has the ability to generate large amounts of Ang-(1-7) in the BDL liver from Ang I only when ACE2 activity is greatly decreased or inhibited.
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Affiliation(s)
- Chandana B. Herath
- Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, Victoria; School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland; and Baker Heart Research Institute, Melbourne, Victoria, Australia
| | - John S. Lubel
- Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, Victoria; School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland; and Baker Heart Research Institute, Melbourne, Victoria, Australia
| | - Zhiyuan Jia
- Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, Victoria; School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland; and Baker Heart Research Institute, Melbourne, Victoria, Australia
| | - Elena Velkoska
- Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, Victoria; School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland; and Baker Heart Research Institute, Melbourne, Victoria, Australia
| | - David Casley
- Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, Victoria; School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland; and Baker Heart Research Institute, Melbourne, Victoria, Australia
| | - Lindsay Brown
- Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, Victoria; School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland; and Baker Heart Research Institute, Melbourne, Victoria, Australia
| | - Chris Tikellis
- Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, Victoria; School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland; and Baker Heart Research Institute, Melbourne, Victoria, Australia
| | - Louise M. Burrell
- Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, Victoria; School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland; and Baker Heart Research Institute, Melbourne, Victoria, Australia
| | - Peter W. Angus
- Department of Medicine, The University of Melbourne, Austin Health, Heidelberg, Victoria; School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland; and Baker Heart Research Institute, Melbourne, Victoria, Australia
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94
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Pereira RM, Santos RASD, Dias FLDC, Teixeira MM, Silva ACSE. Renin-angiotensin system in the pathogenesis of liver fibrosis. World J Gastroenterol 2009; 15:2579-86. [PMID: 19496186 PMCID: PMC2691487 DOI: 10.3748/wjg.15.2579] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Hepatic fibrosis is considered a common response to many chronic hepatic injuries. It is a multifunctional process that involves several cell types, cytokines, chemokines and growth factors leading to a disruption of homeostatic mechanisms that maintain the liver ecosystem. In spite of many studies regarding the development of fibrosis, the understanding of the pathogenesis remains obscure. The hepatic tissue remodeling process is highly complex, resulting from the balance between collagen degradation and synthesis. Among the many mediators that take part in this process, the components of the Renin angiotensin system (RAS) have progressively assumed an important role. Angiotensin (Ang) II acts as a profibrotic mediator and Ang-(1-7), the newly recognized RAS component, appears to exert a counter-regulatory role in liver tissue. We briefly review the liver fibrosis process and current aspects of the RAS. This review also aims to discuss some experimental evidence regarding the participation of RAS mediators in the pathogenesis of liver fibrosis, focusing on the putative role of the ACE2-Ang-(1-7)-Mas receptor axis.
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95
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Oakley F, Teoh V, Ching-A-Sue G, Bataller R, Colmenero J, Jonsson JR, Eliopoulos AG, Watson MR, Manas D, Mann DA. Angiotensin II activates I kappaB kinase phosphorylation of RelA at Ser 536 to promote myofibroblast survival and liver fibrosis. Gastroenterology 2009; 136:2334-2344.e1. [PMID: 19303015 DOI: 10.1053/j.gastro.2009.02.081] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2008] [Revised: 02/18/2009] [Accepted: 02/26/2009] [Indexed: 01/28/2023]
Abstract
BACKGROUND & AIMS The transcription factor nuclear factor-kappaB (NF)-kappaB promotes survival of hepatic myofibroblasts and fibrogenesis through poorly defined mechanisms. We investigated the activities of angiotensin II and I kappaB kinase (IKK) in regulation of NF-kappaB activity and the role of these proteins in liver fibrosis in rodents and humans. METHODS Phosphorylation of the NF-kappaB subunit RelA at serine 536 (P-Ser(536)-RelA) was detected by immunoblot and immunohistochemical analyses. P-Ser(536)-RelA function was assessed using vectors that expressed mutant forms of RelA, cell-permeable blocking peptides, and assays for RelA nuclear transport and apoptosis. Levels of P-Ser(536)-RelA were compared with degree of fibrosis in liver sections from chronically injured rats and patients with hepatitis C virus-mediated fibrosis who had been treated with the AT1 antagonist losartan. RESULTS Constitutive P-Ser(536)-RelA is a feature of human hepatic myofibroblasts, both in vitro and in situ in diseased livers. Autocrine angiotensin II stimulated IKK-mediated phosphorylation of RelA at Ser(536), which was required for nuclear transport and transcriptional activity of NF-kappaB. Inhibition of angiotensin II, the angiotensin II receptor type 1 (AT1), or IKK blocked Ser(536) phosphorylation and stimulated myofibroblast apoptosis. Treatment of fibrotic rodent liver with the angiotensin converting enzyme (ACE) inhibitor captopril or the IKK inhibitor sulphasalazine resulted in loss of P-Ser(536)-RelA-positive myofibroblasts and fibrosis regression. In human liver samples, increased numbers of P-Ser(536)-RelA-positive cells were associated with fibrosis that regressed following exposure to losartan. CONCLUSIONS An autocrine pathway that includes angiotensin II, IKK, and P-Ser(536)-RelA regulates myofibroblast survival and can be targeted to stimulate therapeutic regression of liver fibrosis.
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Affiliation(s)
- Fiona Oakley
- Liver Research Group, Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, United Kingdom
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96
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Current world literature. Curr Opin Endocrinol Diabetes Obes 2009; 16:260-77. [PMID: 19390324 DOI: 10.1097/med.0b013e32832c937e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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97
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Vilas-Boas WW, Jr ARO, Ribeiro RDC, Vieira RLP, Almeida J, Nadu AP, Silva ACSE, Santos RAS. Effect of propranolol on the splanchnic and peripheral renin angiotensin system in cirrhotic patients. World J Gastroenterol 2008; 14:6824-30. [PMID: 19058308 PMCID: PMC2773877 DOI: 10.3748/wjg.14.6824] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To evaluate the effect of β-blockade on angiotensins in the splanchnic and peripheral circulation of cirrhotic patients and also to compare hemodynamic parameters during liver transplantation according to propranolol pre-treatment or not.
METHODS: Patients were allocated into two groups: outpatients with advanced liver disease(LD) and during liver transplantation(LT). Both groups were subdivided according to treatment with propranolol or not. Plasma was collected through peripheral venipuncture to determine plasma renin activity(PRA), Angiotensin(Ang) I, Ang II, and Ang-(1-7) levels by radioimmunoassay in LD group. During liver transplantation, hemodynamic parameters were determined and blood samples were obtained from the portal vein to measure renin angiotensin system(RAS) components.
RESULTS: PRA, Ang I, Ang II and Ang-(1-7) were significantly lower in the portal vein and periphery in all subgroups treated with propranolol as compared to non-treated. The relationships between Ang-(1-7) and Ang I levels and between Ang II and Ang I were significantly increased in LD group receiving propranolol. The ratio between Ang-(1-7) and Ang II remained unchanged in splanchnic and peripheral circulation in patients under β-blockade, whereas the relationship between Ang II and Ang I was significantly increased in splanchnic circulation of LT patients treated with propranolol. During liver transplantation, cardiac output and index as well systemic vascular resistance and index were reduced in propranolol-treated subgroup.
CONCLUSION: In LD group, propranolol treatment reduced RAS mediators, but did not change the ratio between Ang-(1-7) and Ang II in splanchnic and peripheral circulation. Furthermore, the modification of hemodynamic parameters in propranolol treated patients was not associated with changes in the angiotensin ratio.
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