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Dănilă AI, Ghenciu LA, Stoicescu ER, Bolintineanu SL, Iacob R, Săndesc MA, Faur AC. Aldose Reductase as a Key Target in the Prevention and Treatment of Diabetic Retinopathy: A Comprehensive Review. Biomedicines 2024; 12:747. [PMID: 38672103 PMCID: PMC11047946 DOI: 10.3390/biomedicines12040747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2024] [Revised: 03/24/2024] [Accepted: 03/26/2024] [Indexed: 04/28/2024] Open
Abstract
The escalating global prevalence of diabetes mellitus (DM) over the past two decades has led to a persistent high incidence of diabetic retinopathy (DR), necessitating screening for early symptoms and proper treatment. Effective management of DR aims to decrease vision impairment by controlling modifiable risk factors including hypertension, obesity, and dyslipidemia. Moreover, systemic medications and plant-based therapy show promise in advancing DR treatment. One of the key mechanisms related to DR pathogenesis is the polyol pathway, through which aldose reductase (AR) catalyzes the conversion of glucose to sorbitol within various tissues, including the retina, lens, ciliary body and iris. Elevated glucose levels activate AR, leading to osmotic stress, advanced glycation end-product formation, and oxidative damage. This further implies chronic inflammation, vascular permeability, and angiogenesis. Our comprehensive narrative review describes the therapeutic potential of aldose reductase inhibitors in treating DR, where both synthetic and natural inhibitors have been studied in recent decades. Our synthesis aims to guide future research and clinical interventions in DR management.
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Affiliation(s)
- Alexandra-Ioana Dănilă
- Department of Anatomy and Embriology, ‘Victor Babes’ University of Medicine and Pharmacy Timisoara, Eftimie Murgu Square No. 2, 300041 Timisoara, Romania; (A.-I.D.); (S.L.B.); (R.I.); (A.C.F.)
| | - Laura Andreea Ghenciu
- Department of Functional Sciences, ‘Victor Babes’ University of Medicine and Pharmacy Timisoara, Eftimie Murgu Square No. 2, 300041 Timisoara, Romania
| | - Emil Robert Stoicescu
- Doctoral School, ‘Victor Babes’ University of Medicine and Pharmacy Timisoara, Eftimie Murgu Square No. 2, 300041 Timisoara, Romania;
- Field of Applied Engineering Sciences, Specialization Statistical Methods and Techniques in Health and Clinical Research, Faculty of Mechanics, ‘Politehnica’ University Timisoara, Mihai Viteazul Boulevard No. 1, 300222 Timisoara, Romania
- Department of Radiology and Medical Imaging, ‘Victor Babes’ University of Medicine and Pharmacy Timisoara, Eftimie Murgu Square No. 2, 300041 Timisoara, Romania
- Research Center for Pharmaco-Toxicological Evaluations, ‘Victor Babes’ University of Medicine and Pharmacy Timisoara, Eftimie Murgu Square No. 2, 300041 Timisoara, Romania
| | - Sorin Lucian Bolintineanu
- Department of Anatomy and Embriology, ‘Victor Babes’ University of Medicine and Pharmacy Timisoara, Eftimie Murgu Square No. 2, 300041 Timisoara, Romania; (A.-I.D.); (S.L.B.); (R.I.); (A.C.F.)
| | - Roxana Iacob
- Department of Anatomy and Embriology, ‘Victor Babes’ University of Medicine and Pharmacy Timisoara, Eftimie Murgu Square No. 2, 300041 Timisoara, Romania; (A.-I.D.); (S.L.B.); (R.I.); (A.C.F.)
- Doctoral School, ‘Victor Babes’ University of Medicine and Pharmacy Timisoara, Eftimie Murgu Square No. 2, 300041 Timisoara, Romania;
- Field of Applied Engineering Sciences, Specialization Statistical Methods and Techniques in Health and Clinical Research, Faculty of Mechanics, ‘Politehnica’ University Timisoara, Mihai Viteazul Boulevard No. 1, 300222 Timisoara, Romania
| | - Mihai-Alexandru Săndesc
- Department of Orthopedics and Traumatology, ‘Victor Babes’ University of Medicine and Pharmacy Timisoara, Eftimie Murgu Square No. 2, 300041 Timisoara, Romania;
| | - Alexandra Corina Faur
- Department of Anatomy and Embriology, ‘Victor Babes’ University of Medicine and Pharmacy Timisoara, Eftimie Murgu Square No. 2, 300041 Timisoara, Romania; (A.-I.D.); (S.L.B.); (R.I.); (A.C.F.)
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Jerome JR, Deliyanti D, Suphapimol V, Kolkhof P, Wilkinson-Berka JL. Finerenone, a Non-Steroidal Mineralocorticoid Receptor Antagonist, Reduces Vascular Injury and Increases Regulatory T-Cells: Studies in Rodents with Diabetic and Neovascular Retinopathy. Int J Mol Sci 2023; 24:ijms24032334. [PMID: 36768656 PMCID: PMC9917037 DOI: 10.3390/ijms24032334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 01/20/2023] [Accepted: 01/21/2023] [Indexed: 01/26/2023] Open
Abstract
Vision loss in diabetic retinopathy features damage to the blood-retinal barrier and neovascularization, with hypertension and the renin-angiotensin system (RAS) having causal roles. We evaluated if finerenone, a non-steroidal mineralocorticoid receptor (MR) antagonist, reduced vascular pathology and inflammation in diabetic and neovascular retinopathy. Diabetic and hypertensive transgenic (mRen-2)27 rats overexpressing the RAS received the MR antagonist finerenone (10 mg/kg/day, oral gavage) or the angiotensin-converting enzyme inhibitor perindopril (10 mg/kg/day, drinking water) for 12 weeks. As retinal neovascularization does not develop in diabetic rodents, finerenone (5 mg/kg/day, i.p.) was evaluated in murine oxygen-induced retinopathy (OIR). Retinal vasculopathy was assessed by measuring gliosis, vascular leakage, neovascularization, and VEGF. Inflammation was investigated by quantitating retinal microglia/macrophages, pro-inflammatory mediators, and anti-inflammatory regulatory T-cells (Tregs). In diabetes, both treatments reduced systolic blood pressure, gliosis, vascular leakage, and microglial/macrophage density, but only finerenone lowered VEGF, ICAM-1, and IL-1ß. In OIR, finerenone reduced neovascularization, vascular leakage, and microglial density, and increased Tregs in the blood, spleen, and retina. Our findings, in the context of the FIDELIO-DKD and FIGARO-DKD trials reporting the benefits of finerenone on renal and cardiovascular outcomes in diabetic kidney disease, indicate the potential of finerenone as an effective oral treatment for diabetic retinopathy.
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Affiliation(s)
- Jack R. Jerome
- Department of Anatomy and Physiology, School of Biomedical Sciences, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Devy Deliyanti
- Department of Anatomy and Physiology, School of Biomedical Sciences, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Varaporn Suphapimol
- Department of Anatomy and Physiology, School of Biomedical Sciences, The University of Melbourne, Parkville, VIC 3010, Australia
| | | | - Jennifer L. Wilkinson-Berka
- Department of Anatomy and Physiology, School of Biomedical Sciences, The University of Melbourne, Parkville, VIC 3010, Australia
- Correspondence:
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Raheem NM, Mohammed Ali Mahmood N. Azilsartan suppresses the antiapoptotic biomarker and pro-inflammatory cytokines in rat model of cisplatin-induced retinal and optic nerve toxicity. Hum Exp Toxicol 2023; 42:9603271231155092. [PMID: 36930951 DOI: 10.1177/09603271231155092] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2023]
Abstract
BACKGROUND The local renin-angiotensin system has been discovered in the eyes; thus, this study evaluates the Azilsartan effect in the retina and optic nerve toxicity induced by Cisplatin in vivo. METHODOLOGY Forty-eight male rats were randomly assigned into six groups of 8 animals. Group 1 was healthy control that received 0.5 mL/day of 0.5% carboxymethyl cellulose (CMC) orally (PO). Group 2 received a single dose of the 7.0 mg/kg CIS intraperitoneally with 0.5 mL/day of 0.5% CMC-PO. Groups 3 and 4 received 3.5 and 7.0 mg/kg/day of AZIL-PO, respectively. Groups 5 and 6 received 3.5 and 7.0 mg/kg/day of AZIL-PO, respectively together with a single dose of 7.0 mg/kg of CIS-IP. The ocular tissue and serum estimated the TNF-α, NF-kβ, and Casp-3. A complete blood count was also measured, and the eye was sent for histological examination. RESULTS The administration of the 3.5 mg/kg AZIL significantly (p < 0.05) reduced the ocular tissue and serum TNF-α, NF-kB, and Casp-3 levels, when given to CIS treated group, while the 7.0 mg/kg AZIL does not. Additionally, azilsartan shows no negative impact on the CBC in rats. Finally, the eye histological examination showed a significant (p < 0.05) drop in the signs of inflammation and cellular degeneration, particularly after administration of the 3.5 mg/kg AZIL to the CIS-treated group. CONCLUSION A low dose of AZIL exerts an anti-inflammation and an anti-apoptotic effect through significant suppression of the pro-inflammatory mediators and an apoptotic biomarker by blocking the local angiotensin II type.
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Affiliation(s)
- Noor Majid Raheem
- Department of Pharmacology and Toxicology, College of Pharmacy, 275719University of Sulaimani, Sulaimaniyah, Iraq
| | - Naza Mohammed Ali Mahmood
- Department of Pharmacology and Toxicology, College of Pharmacy, 275719University of Sulaimani, Sulaimaniyah, Iraq
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Starace V, Battista M, Brambati M, Cavalleri M, Bertuzzi F, Amato A, Lattanzio R, Bandello F, Cicinelli MV. The role of inflammation and neurodegeneration in diabetic macular edema. Ther Adv Ophthalmol 2021; 13:25158414211055963. [PMID: 34901746 PMCID: PMC8652911 DOI: 10.1177/25158414211055963] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 10/08/2021] [Indexed: 12/14/2022] Open
Abstract
The pathogenesis of diabetic macular edema (DME) is complex. Persistently high blood glucose activates multiple cellular pathways and induces inflammation, oxidation stress, and vascular dysfunction. Retinal ganglion cells, macroglial and microglial cells, endothelial cells, pericytes, and retinal pigment epithelium cells are involved. Neurodegeneration, characterized by dysfunction or apoptotic loss of retinal neurons, occurs early and independently from the vascular alterations. Despite the increasing knowledge on the pathways involved in DME, only limited therapeutic strategies are available. Besides antiangiogenic drugs and intravitreal corticosteroids, alternative therapeutic options tackling inflammation, oxidative stress, and neurodegeneration have been considered, but none of them has been currently approved.
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Affiliation(s)
- Vincenzo Starace
- Department of Ophthalmology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Marco Battista
- Department of Ophthalmology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Maria Brambati
- Department of Ophthalmology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Michele Cavalleri
- Department of Ophthalmology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Federico Bertuzzi
- Department of Ophthalmology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Alessia Amato
- Department of Ophthalmology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Rosangela Lattanzio
- Department of Ophthalmology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Francesco Bandello
- Department of Ophthalmology, IRCCS San Raffaele Scientific Institute, Milan, ItalySchool of Medicine, Vita-Salute San Raffaele University, Milan, Italy
| | - Maria Vittoria Cicinelli
- Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, via Olgettina 60, 20132 Milan, ItalySchool of Medicine, Vita-Salute San Raffaele University, Milan, Italy
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Silva M, Peng T, Zhao X, Li S, Farhan M, Zheng W. Recent trends in drug-delivery systems for the treatment of diabetic retinopathy and associated fibrosis. Adv Drug Deliv Rev 2021; 173:439-460. [PMID: 33857553 DOI: 10.1016/j.addr.2021.04.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 03/05/2021] [Accepted: 04/08/2021] [Indexed: 12/12/2022]
Abstract
Diabetic retinopathy is a frequent microvascular complication of diabetes and a major cause of visual impairment. In advanced stages, the abnormal neovascularization can lead to fibrosis and subsequent tractional retinal detachment and blindness. The low bioavailability of the drugs at the target site imposed by the anatomic and physiologic barriers within the eye, requires long term treatments with frequent injections that often compromise patient's compliance and increase the risk of developing more complications. In recent years, much effort has been put towards the development of new drug delivery platforms aiming to enhance their permeation, to prolong their retention time at the target site and to provide a sustained release with reduced toxicity and improved efficacy. This review provides an overview of the etiology and pathophysiology of diabetic retinopathy and current treatments. It addresses the specific challenges associated to the different ocular delivery routes and provides a critical review of the most recent developments made in the drug delivery field.
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Affiliation(s)
- Marta Silva
- Centre of Reproduction, Development and Aging, Institute of Translational Medicine, Faculty of Health Sciences, University of Macau, Macau
| | - Tangming Peng
- Centre of Reproduction, Development and Aging, Institute of Translational Medicine, Faculty of Health Sciences, University of Macau, Macau
| | - Xia Zhao
- Centre of Reproduction, Development and Aging, Institute of Translational Medicine, Faculty of Health Sciences, University of Macau, Macau
| | - Shuai Li
- Centre of Reproduction, Development and Aging, Institute of Translational Medicine, Faculty of Health Sciences, University of Macau, Macau
| | - Mohd Farhan
- Centre of Reproduction, Development and Aging, Institute of Translational Medicine, Faculty of Health Sciences, University of Macau, Macau
| | - Wenhua Zheng
- Centre of Reproduction, Development and Aging, Institute of Translational Medicine, Faculty of Health Sciences, University of Macau, Macau.
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Fletcher EL, Phipps JA, Wilkinson-Berka JL. Dysfunction of retinal neurons and glia during diabetes. Clin Exp Optom 2021; 88:132-45. [PMID: 15926876 DOI: 10.1111/j.1444-0938.2005.tb06686.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2004] [Revised: 04/15/2005] [Accepted: 04/23/2005] [Indexed: 12/27/2022] Open
Abstract
Diabetic retinopathy is the leading cause of blindness in those of working age. It is well known that the retinal vasculature is altered during diabetes. More recently, it has emerged that neuronal and glial dysfunction occurs in those with diabetes. Current research is directed at understanding these neuronal and glial changes because they may be an early manifestation of disease processes that ultimately lead to vascular abnormality. This review will highlight the recent advances in our understanding of the neuronal and glial changes that occur during diabetes.
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Affiliation(s)
- Erica L Fletcher
- Department of Anatomy and Cell Biology, The University of Melbourne, Grattan Street, Parkville, VIC 3010, Australia
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Effect of Adding Losartan to Bevacizumab for Treating Diabetic Macular Edema. J Ophthalmol 2020; 2020:4528491. [PMID: 33062311 PMCID: PMC7547354 DOI: 10.1155/2020/4528491] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Revised: 07/21/2020] [Accepted: 08/18/2020] [Indexed: 12/02/2022] Open
Abstract
Introduction Diabetic retinopathy is the most common cause of visual loss and blindness in the age group of 20 to 64 years. This study aimed to evaluate the efficacy of oral Losartan adjuvant therapy in combination with intravitreal injection of Bevacizumab in the treatment of diabetic macular edema. Methods In this randomized clinical trial, 61 eyes of 47 patients with normal blood pressure and diabetic macular edema and nonproliferative diabetic retinopathy were studied. Patients were randomly divided into Losartan (n = 33) and control (n = 28) groups. All patients received 3–6 intravitreal injections of Bevacizumab over 6 months. General examination including blood pressure and glycosylated hemoglobin measurements were performed in all patients. Complete ophthalmologic examination and macular OCT were performed at the first, third, and sixth months of treatment in all patients. Results The mean age of the patients studied was 57.1 ± 7.4 years and 37.7% of the patients were male. There was no significant difference between the two groups in terms of initial visual acuity, central macular thickness, and frequency of injections. There was no significant difference in visual acuity and central macular thickness between the two groups at the first, third, and sixth months of treatment. Age, frequency of injection, and initial macular thickness less than 450 microns were effective in patients' final visual acuity. Conclusion Short-term adjuvant treatment with Losartan in patients with diabetic macular edema and nonproliferative diabetic retinopathy has no greater effect than the standard treatment.
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Ramírez-Montero C, Lima-Gómez V, Anguiano-Robledo L, Hernández-Campos ME, López-Sánchez P. Preeclampsia as predisposing factor for hypertensive retinopathy: Participation by the RAAS and angiogenic factors. Exp Eye Res 2020; 193:107981. [PMID: 32088240 DOI: 10.1016/j.exer.2020.107981] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 02/17/2020] [Accepted: 02/17/2020] [Indexed: 12/26/2022]
Abstract
Preeclampsia (PE) is a hypertensive complication of pregnancy. Its cause is still unknown and it could be a risk factor for future ophthalmic problems. Retinal vascular bed alterations have been described as a consequence of PE, suggesting a retinopathy. Factors related to angiogenesis and vascular permeability, such as vascular endothelial growth factor (VEGF) and pigment epithelium derived factor (PEDF) or components of the renin angiotensin aldosterone system (RAAS), prorrenin/renin receptor ((P)RR) and angiotensin II type I receptor (AT1R) have been located in the retina, participating in other retinopathies, but it is unknown if they could participate in PE. Our aim was to elucidate whether VEGF, PEDF, (P)RR and AT1R could be modified during PE and during hypertension induced in rats with a history of PE. We used female Wistar rats and subrrenal aortic coarctation to induce PE, and after delivery, we induced a second hit by Nω-nitro-L-arginine methyl ester (L-NAME) administration. We measured blood pressure, proteinuria and pups development. In both models, eye fundal exploration and immunoblot for VEGF, PEDF, (P)RR and AT1R were performed. We found that the development of hypertension occurred faster in previously PE rats than in normal animals. VEGF, PEDF, (P)RR and AT1R were increased in PE, but in L-NAME-induced hypertension only (P)RR and AT1R were altered. Eye fundal data indicated that PE induced a level I retinopathy, but L-NAME induced a faster and more severe retinopathy in previously PE animals compared to previously normal pregnancy rats. These results indicate that PE predisposes to development of a faster and more severe retinopathy after a second hit. They also suggest that VEGF and PEDF seem to participate only in PE retinopathy, but in both models, RAAS components seem to have a more critical participation.
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Affiliation(s)
- Claudia Ramírez-Montero
- Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina Del Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón s/n, Casco de Santo Tomás, Ciudad de México, 11340, Mexico.
| | - Virgilio Lima-Gómez
- Servicio de Oftalmología, Hospital Juárez de México Norte, Av. Instituto Politécnico Nacional 5160, Col. Magdalena de la Salinas, Del. Gustavo A. Madero, C.P 07760, Mexico.
| | - Liliana Anguiano-Robledo
- Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina Del Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón s/n, Casco de Santo Tomás, Ciudad de México, 11340, Mexico.
| | - María Elena Hernández-Campos
- Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina Del Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón s/n, Casco de Santo Tomás, Ciudad de México, 11340, Mexico.
| | - Pedro López-Sánchez
- Sección de Estudios de Posgrado e Investigación, Escuela Superior de Medicina Del Instituto Politécnico Nacional, Plan de San Luis y Díaz Mirón s/n, Casco de Santo Tomás, Ciudad de México, 11340, Mexico.
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Rana I, Suphapimol V, Jerome JR, Talia DM, Deliyanti D, Wilkinson-Berka JL. Angiotensin II and aldosterone activate retinal microglia. Exp Eye Res 2019; 191:107902. [PMID: 31884019 DOI: 10.1016/j.exer.2019.107902] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 11/13/2019] [Accepted: 12/20/2019] [Indexed: 12/19/2022]
Abstract
Microglial cells are important contributors to the neuroinflammation and blood vessel damage that occurs in ischemic retinopathies. We hypothesized that key effectors of the renin-angiotensin aldosterone system, angiotensin II (Ang II) and aldosterone, increase the density of microglia in the retina and stimulate their production of reactive oxygen species (ROS) as well as pro-angiogenic and pro-inflammatory factors. Two animal models were studied that featured up-regulation of Ang II or aldosterone and included transgenic Ren-2 rats which overexpress renin and Ang II in tissues including the retina, and Sprague Dawley rats with ischemic retinopathy and infused with aldosterone. Complementary studies were performed in primary cultures of retinal microglia from neonatal Sprague Dawley rats exposed to hypoxia (0.5% O2) and inhibitors of the angiotensin type 1 receptor (valsartan), the mineralocorticoid receptor (spironolactone) or aldosterone synthase (FAD286). In both in vivo models, the density of ionized calcium-binding adaptor protein-1 labelled microglia/macrophages was increased in retina compared to genetic or vehicle controls. In primary cultures of retinal microglia, hypoxia increased ROS (superoxide) levels as well as the expression of the NADPH oxidase (NOX) isoforms, NOX1, NOX2 and NOX4. The elevated levels of ROS as well as NOX2 and NOX4 were reduced by all of the treatments, and valsartan and FAD286 also reduced NOX1 mRNA levels. A protein cytokine array of retinal microglia revealed that valsartan, spironolactone and FAD286 reduced the hypoxia-induced increase in the potent pro-angiogenic and pro-inflammatory agent, vascular endothelial growth factor as well as the inflammatory factors, CCL5 and interferon γ. Valsartan also reduced the hypoxia-induced increase in IL-6 and TIMP-1 as well as the chemoattractants, CXCL2, CXCL3, CXCL5 and CXCL10. Spironolactone and FAD286 reduced the levels of CXCL2 and CXCL10, respectively. In conclusion, our findings that both Ang II and aldosterone influence the activation of retinal microglia implicates the renin-angiotensin aldosterone system in the pathogenesis of ischemic retinopathies.
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Affiliation(s)
- Indrajeetsinh Rana
- Department of Immunology and Pathology, The Central Clinical School, Monash University, Melbourne, Victoria, Australia; Victoria University, Ballarat Road, Footscray, Victoria, Australia
| | - Varaporn Suphapimol
- Department of Diabetes, The Central Clinical School, Monash University, Melbourne, Victoria, Australia; Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, Victoria, Australia
| | - Jack R Jerome
- Department of Diabetes, The Central Clinical School, Monash University, Melbourne, Victoria, Australia; Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, Victoria, Australia
| | - Dean M Talia
- Department of Immunology and Pathology, The Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - Devy Deliyanti
- Department of Diabetes, The Central Clinical School, Monash University, Melbourne, Victoria, Australia; Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, Victoria, Australia
| | - Jennifer L Wilkinson-Berka
- Department of Diabetes, The Central Clinical School, Monash University, Melbourne, Victoria, Australia; Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, Victoria, Australia.
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10
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Wilkinson-Berka JL, Suphapimol V, Jerome JR, Deliyanti D, Allingham MJ. Angiotensin II and aldosterone in retinal vasculopathy and inflammation. Exp Eye Res 2019; 187:107766. [PMID: 31425690 DOI: 10.1016/j.exer.2019.107766] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 08/14/2019] [Accepted: 08/15/2019] [Indexed: 12/18/2022]
Abstract
Angiotensin II and aldosterone are the main effectors of the renin-angiotensin aldosterone system (RAAS) and have a central role in hypertension as well as cardiovascular and renal disease. The localization of RAAS components within the retina has led to studies investigating the roles of angiotensin II, aldosterone and the counter regulatory arm of the pathway in vision-threatening retinopathies. This review will provide a brief overview of RAAS components as well as the vascular pathology that develops in the retinal diseases, retinopathy of prematurity, diabetic retinopathy and neovascular age-related macular degeneration. The review will discuss pre-clinical and clinical evidence that modulation of the RAAS alters the development of vasculopathy and inflammation in the aforementioned retinopathies, as well as the emerging role of aldosterone and the mineralocorticoid receptor in central serous chorioretinopathy.
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Affiliation(s)
- Jennifer L Wilkinson-Berka
- Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, Victoria, Australia; Department of Diabetes, The Central Clinical School, Monash University, Melbourne, Victoria, Australia.
| | - Varaporn Suphapimol
- Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, Victoria, Australia; Department of Diabetes, The Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - Jack R Jerome
- Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, Victoria, Australia; Department of Diabetes, The Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - Devy Deliyanti
- Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, Victoria, Australia; Department of Diabetes, The Central Clinical School, Monash University, Melbourne, Victoria, Australia
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Mirabito Colafella KM, Bovée DM, Danser AHJ. The renin-angiotensin-aldosterone system and its therapeutic targets. Exp Eye Res 2019; 186:107680. [PMID: 31129252 DOI: 10.1016/j.exer.2019.05.020] [Citation(s) in RCA: 92] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 05/16/2019] [Accepted: 05/22/2019] [Indexed: 12/22/2022]
Abstract
The renin-angiotensin-aldosterone system (RAAS) plays a pivotal role in the regulation of blood pressure and body fluid homeostasis and is a mainstay for the treatment of cardiovascular and renal diseases. Angiotensin II and aldosterone are the two most powerful biologically active products of the RAAS, inducing all of the classical actions of the RAAS including vasoconstriction, sodium retention, tissue remodeling and pro-inflammatory and pro-fibrotic effects. In recent years, new components of the RAAS have been discovered beyond the classical pathway that have led to the identification of depressor or so-called protective RAAS pathways and the development of novel therapies targeting this system. Moreover, dual inhibitors which block the RAAS and other systems involved in the regulation of blood pressure or targeting upstream of angiotensin II by selectively deleting liver-derived angiotensinogen, the precursor to all angiotensins, may provide superior treatment for cardiovascular and renal diseases and revolutionize RAAS-targeting therapy.
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Affiliation(s)
- Katrina M Mirabito Colafella
- Cardiovascular Disease Program, Biomedicine Discovery Institute and Department of Physiology, Monash University, Melbourne, Australia
| | - Dominique M Bovée
- Division of Pharmacology and Vascular Medicine, Department of Internal Medicine, Erasmus MC, University Medical Centre, Rotterdam, The Netherlands
| | - A H Jan Danser
- Division of Pharmacology and Vascular Medicine, Department of Internal Medicine, Erasmus MC, University Medical Centre, Rotterdam, The Netherlands.
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Perturbed Biochemical Pathways and Associated Oxidative Stress Lead to Vascular Dysfunctions in Diabetic Retinopathy. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:8458472. [PMID: 30962865 PMCID: PMC6431380 DOI: 10.1155/2019/8458472] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Revised: 12/26/2018] [Accepted: 01/27/2019] [Indexed: 02/08/2023]
Abstract
Diabetic retinopathy (DR) is a vascular insult that accompanies the hyperglycemic state. Retinal vasculature holds a pivotal role in maintaining the integrity of the retina, and any alteration to retinal vasculature affects retinal functions. The blood retinal barrier, a prerequisite to vision acuity, is most susceptible to damage during the progression of DR. This is a consequence of impaired biochemical pathways such as the polyol, advanced end glycation products (AGE), hexosamine, protein kinase C (PKC), and tissue renin-angiotensin system (RAS) pathways. Moreover, the role of histone modification and altered miRNA expression is also emerging as a major contributor. Epigenetic changes create a link between altered protein function and redox status of retinal cells, creating a state of metabolic memory. Although various biochemical pathways underlie the etiology of DR, the major insult to the retina is due to oxidative stress, a unifying factor of altered biochemical pathways. This review primarily focuses on the critical biochemical pathways altered in DR leading to vascular dysfunctions and discusses antioxidants as plausible treatment strategies.
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Senanayake PD, Bonilha VL, W Peterson J, Yamada Y, Karnik SS, Daneshgari F, Brosnihan KB, Hollyfield JG. Retinal angiotensin II and angiotensin-(1-7) response to hyperglycemia and an intervention with captopril. J Renin Angiotensin Aldosterone Syst 2019; 19:1470320318789323. [PMID: 30126320 PMCID: PMC6104213 DOI: 10.1177/1470320318789323] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Hypothesis: Hyperglycemia decreases angiotensin-(1-7), the endogenous counter-regulator of angiotensin II in the retina. Materials and methods: The distribution and levels of retinal angiotensin II (Ang II) and angiotensin-(1-7) (Ang-(1-7)) were evaluated by confocal imaging and quantitative immunohistochemistry during the development of streptozotocin-induced diabetes in rats. Results: In the nondiabetic eye, Ang II was localized to the endfeet of Müller cells, extending into the cellular processes of the inner plexiform layer and inner nuclear layer; Ang-(1-7) showed a wider distribution, extending from the foot plates of the Müller cells to the photoreceptor layer. Eyes from diabetic animals showed a higher intensity and extent of Ang II staining compared with nondiabetic eyes, but lower intensity with a reduced distribution of Ang-(1-7) immunoreactivity. Treatment of the diabetic animals with the angiotensin-converting enzyme inhibitor (ACEI) captopril showed a reduced intensity of Ang II staining, whereas increased intensity and distribution were evident with Ang-(1-7) staining. Conclusions: These studies reveal that pharmacological inhibition with ACEIs may provide a specific intervention for the management of the diabetes-induced decline in retinal function, reversing the profile of the endogenous angiotensin peptides closer to the normal condition.
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Affiliation(s)
- Preenie deS Senanayake
- 1 Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, USA.,2 Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine at Case Western Reserve University, Cleveland, USA
| | - Vera L Bonilha
- 1 Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, USA.,2 Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine at Case Western Reserve University, Cleveland, USA
| | - John W Peterson
- 3 Reseach Core Services (Imaging) Cleveland Clinic, Cleveland, USA
| | - Yoshiro Yamada
- 4 Department of Urology, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Sadashiva S Karnik
- 5 Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, USA
| | - Firouz Daneshgari
- 6 Department of Urology (FD), Case Western Reserve University, University Hospitals Case Medical Center, Cleveland, USA
| | - K Bridget Brosnihan
- 7 Department of Surgery, Hypertension & Vascular Research, Cardiovascular Sciences Center, Wake Forest University School of Medicine, Winston-Salem, USA
| | - Joe G Hollyfield
- 1 Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, USA.,2 Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine at Case Western Reserve University, Cleveland, USA
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Qian X, Lin L, Zong Y, Yuan Y, Dong Y, Fu Y, Shao W, Li Y, Gao Q. Shifts in renin-angiotensin system components, angiogenesis, and oxidative stress-related protein expression in the lamina cribrosa region of streptozotocin-induced diabetic mice. Graefes Arch Clin Exp Ophthalmol 2018; 256:525-534. [PMID: 29404759 DOI: 10.1007/s00417-017-3866-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 10/26/2017] [Accepted: 12/11/2017] [Indexed: 12/16/2022] Open
Abstract
PURPOSE This study aimed to analyse shifts in renin-angiotensin system (RAS) components, angiogenesis, and oxidative stress-related protein expression in the lamina cribrosa (LC) region in streptozotocin (STZ)-induced diabetic mice. METHODS Six months after diabetes induction, the retinal vessels of male C57BL/6 J mice were observed by colour photography, fundus fluorescein angiography (FFA), and immunofluorescent staining following incubation with CD31. Immunofluorescence for glial fibrillary acidic protein (GFAP), alpha-smooth muscle actin (α-SMA),and NG2 was also performed. Angiotensin-converting enzyme 1 (ACE1), angiotensin II type I receptor (AT1R), renin, hypoxia-inducible factor 1-alpha (HIF-1α), vascular endothelial growth factor (VEGF), vascular endothelial growth factor receptor 2 (VEGFR2), and haeme oxygenase 1 (HO-1) expression levels were confirmed by immunohistochemical and western blotting analyses. RESULTS Compared with control mice, diabetic mice had significantly higher blood glucose concentrations (p < 0.001) and significantly lower body weights (p < 0.001). Colour photography and FFA did not reveal any vessel abnormalities in the diabetic mice; however, immunostaining of whole-mount retinas revealed an increased number of retinal vessels. Furthermore, histopathological staining showed significant reduction in the whole retinal thickness. GFAP expression was slightly higher, whereas fewer NG2+ pericytes were observed in diabetic mice than in control mice. ACE1, AT1R, renin, HIF-1α, VEGF, VEGFR2, and HO-1 expression were up-regulated in the LC of the STZ-induced diabetic mice. CONCLUSIONS Collectively, ACE 1, AT1R, HIF-1α, VEGF, VEGFR2, and HO-1 activation in the LC region in diabetic mice may be involved in diabetes via the RAS and induction of angiogenesis and oxidative stress.
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Affiliation(s)
- Xiaobing Qian
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, China
| | - Leilei Lin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, China
| | - Yao Zong
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, China
| | - Yongguang Yuan
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, China
| | - Yanmin Dong
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, China
| | - Yue Fu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, China
| | - Wanwen Shao
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, China
| | - Yujie Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, China
| | - Qianying Gao
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, 510060, China.
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Alrashdi SF, Deliyanti D, Talia DM, Wilkinson-Berka JL. Endothelin-2 Injures the Blood-Retinal Barrier and Macroglial Müller Cells: Interactions with Angiotensin II, Aldosterone, and NADPH Oxidase. THE AMERICAN JOURNAL OF PATHOLOGY 2017; 188:805-817. [PMID: 29248456 DOI: 10.1016/j.ajpath.2017.11.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 10/20/2017] [Accepted: 11/07/2017] [Indexed: 02/07/2023]
Abstract
Although increasing evidence indicates that endothelin-2 (Edn2) has distinct roles in tissue pathology, including inflammation, glial cell dysfunction, and angiogenesis, its role in the retina and the factors that regulate its actions are not fully understood. We hypothesized that Edn2 damages the blood-retinal barrier (BRB) and that this is mediated by interactions with the renin-angiotensin-aldosterone system and reactive oxygen species derived from NADPH oxidase (Nox). C57BL/6J mice received an intravitreal injection of Edn2 or control vehicle to examine the blood pressure-independent effects of Edn2. Mice administered Edn2 were randomized to receive by intraperitoneal injection treatments that inhibited the Edn type a receptor, Edn type b receptor, angiotensin type 1 receptor, mineralocorticoid receptor, or Nox isoforms 1 to 4. One month later, mice administered Edn2 exhibited breakdown of the BRB with increased vascular leakage, vascular endothelial growth factor expression, and infiltrating macrophages (Ly6C+CD45highCD11b+). Further, macroglial Müller cells, which influence the integrity of the BRB and prevent retinal edema, became gliotic and expressed increased levels of water (aquaporin-4) and ion (Kir4.1) channels. This Edn2-mediated retinopathy was reduced by all treatments. Complementary in vitro studies in cultured Müller cells supported these findings and demonstrated the importance of reactive oxygen species in mediating these events. In conclusion, Edn2 has detrimental effects on the BRB and Müller cells that involve interactions with the renin-angiotensin aldosterone system and Nox1/4.
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Affiliation(s)
- Saeed F Alrashdi
- Department of Diabetes, Monash University, Melbourne, Victoria, Australia
| | - Devy Deliyanti
- Department of Diabetes, Monash University, Melbourne, Victoria, Australia
| | - Dean M Talia
- Department of Diabetes, Monash University, Melbourne, Victoria, Australia
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Prasad T, Roksnoer LCW, Zhu P, Verma A, Li Y, Batenburg WW, de Vries R, Danser AHJ, Li Q. Beneficial Effects of Combined AT1 Receptor/Neprilysin Inhibition (ARNI) Versus AT1 Receptor Blockade Alone in the Diabetic Eye. Invest Ophthalmol Vis Sci 2017; 57:6722-6730. [PMID: 27951594 PMCID: PMC5156511 DOI: 10.1167/iovs.16-20289] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Purpose Dysfunction of the renin-angiotensin system (RAS) contributes to pathogenesis of diabetic retinopathy (DR). Yet RAS blockers have only limited beneficial effects on progression of DR in clinical trials. The natriuretic peptide system offsets RAS, so that enhancing the activity of this system on top of RAS blockade might be beneficial. Neprilysin has an important role in the degradation of natriuretic peptides. Therefore, we hypothesize that dual angiotensin receptor-neprilysin inhibition (ARNI) may outperform angiotensin receptor blocker (ARB) in protection against DR. We tested this hypothesis in streptozotocin-induced diabetic transgenic (mRen2)27 rats. Methods Adult male diabetic (mRen2)27 rats were followed for 5 or 12 weeks. Treatment with vehicle, irbesartan (ARB), or ARB combined with the neprilysin inhibitor thiorphan (irbesartan+thiorphan [ARNI]) occurred during the final 3 weeks. Retinal cell death, gliosis, and capillary loss were evaluated. Real-time polymerase chain reaction (RT-PCR) analyses were performed to quantify the retinal level of inflammatory cell markers. Results Both ARB- and ARNI-treated groups showed similarly reduced retinal apoptotic cell death, gliosis, and capillary loss compared to the vehicle-treated group in the 5-week study. Treatment with ARNI reduced the expression of inflammatory markers more than ARB treatment in the 5-week study. In the 12-week study, ARNI treatment showed significantly more reduction in apoptotic cell death (51% vs. 25% reduction), and capillary loss (68% vs. 43% reduction) than ARB treatment. Conclusions Treatment with ARNI provides better protection against DR in diabetic (mRen2)27 transgenic rats, compared to ARB alone. This approach may be a promising treatment option for patients with DR.
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Affiliation(s)
- Tuhina Prasad
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida, United States
| | - Lodi C W Roksnoer
- Division of Pharmacology and Vascular Medicine, Department of Internal Medicine, Erasmus MC, Rotterdam, The Netherlands
| | - Ping Zhu
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida, United States
| | - Amrisha Verma
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida, United States
| | - Yiming Li
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida, United States
| | - Wendy W Batenburg
- Division of Pharmacology and Vascular Medicine, Department of Internal Medicine, Erasmus MC, Rotterdam, The Netherlands
| | - René de Vries
- Division of Pharmacology and Vascular Medicine, Department of Internal Medicine, Erasmus MC, Rotterdam, The Netherlands
| | - A H Jan Danser
- Division of Pharmacology and Vascular Medicine, Department of Internal Medicine, Erasmus MC, Rotterdam, The Netherlands
| | - Qiuhong Li
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida, United States
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Cheng L, Yu H, Yan N, Lai K, Xiang M. Hypoxia-Inducible Factor-1α Target Genes Contribute to Retinal Neuroprotection. Front Cell Neurosci 2017; 11:20. [PMID: 28289375 PMCID: PMC5326762 DOI: 10.3389/fncel.2017.00020] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Accepted: 01/23/2017] [Indexed: 02/05/2023] Open
Abstract
Hypoxia-inducible factor (HIF) is a transcription factor that facilitates cellular adaptation to hypoxia and ischemia. Long-standing evidence suggests that one isotype of HIF, HIF-1α, is involved in the pathogenesis of various solid tumors and cardiac diseases. However, the role of HIF-1α in retina remains poorly understood. HIF-1α has been recognized as neuroprotective in cerebral ischemia in the past two decades. Additionally, an increasing number of studies has shown that HIF-1α and its target genes contribute to retinal neuroprotection. This review will focus on recent advances in the studies of HIF-1α and its target genes that contribute to retinal neuroprotection. A thorough understanding of the function of HIF-1α and its target genes may lead to identification of novel therapeutic targets for treating degenerative retinal diseases including glaucoma, age-related macular degeneration, diabetic retinopathy, and retinal vein occlusions.
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Affiliation(s)
- Lin Cheng
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University Guangzhou, China
| | - Honghua Yu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen UniversityGuangzhou, China; Department of Ophthalmology, General Hospital of Guangzhou Military Command of PLAGuangzhou, China
| | - Naihong Yan
- Department of Ophthalmology and Ophthalmic Laboratories, State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University Chengdu, China
| | - Kunbei Lai
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University Guangzhou, China
| | - Mengqing Xiang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen UniversityGuangzhou, China; Center for Advanced Biotechnology and Medicine and Department of Pediatrics, Rutgers University-Robert Wood Johnson Medical SchoolPiscataway, NJ, USA
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18
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Nath M, Chandra P, Halder N, Singh B, Deorari AK, Kumar A, Azad R, Velpandian T. Involvement of Renin-Angiotensin System in Retinopathy of Prematurity - A Possible Target for Therapeutic Intervention. PLoS One 2016; 11:e0168809. [PMID: 28033392 PMCID: PMC5199007 DOI: 10.1371/journal.pone.0168809] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 12/06/2016] [Indexed: 01/24/2023] Open
Abstract
Objective Examining the Retinal Renin Angiotensin System (RRAS) in the ROP neonates and analyzing the possibility of modulating the RRAS to prevent the progression in Oxygen Induced Retinopathy (OIR) model. Method Vitreous of ROP patients (n = 44, median age 5.5 months) was quantified for RRAS components, VEGF, HIF-1α and compared with age matched control. The involvement of RRAS in ROP was tested in the rat model of OIR and compared with normoxia. Expressions of RAS components, VEGF and HIF-1α in retina were analyzed using qPCR and retinal structure and function was also analyzed. Effect of Angiotensin Converting Enzyme Inhibitor (ACEI) and Angiotensin Receptor Blocker (ARB) was evaluated and compared with Bevacizumab which served as a positive control. Drug penetration into retina was confirmed by liquid chromatography coupled ESI-tandem mass spectroscopy (LC-MS/MS). Results Multifold increase in the expression of RAS components in human vitreous and rat retina showed their involvement in ROP. ERG & fundus studies in OIR revealed the altered function of retina and were successfully prevented by ARB (telmisartan), ACEI (lisinopril) and bevacizumab. Retinal analysis revealed the presence of ACEI and ARB in their therapeutic levels. Conclusion This study for the first time demonstrates the upregulated level of RAS components in human ROP vitreous and further that the pharmacological intervention in RRAS can functionally and structurally preserve retina against the progression of ROP in the OIR model.
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Affiliation(s)
- Madhu Nath
- Dept. Of Ophthalmology, Dr. Rajendra Prasad Center for Ophthalmic Sciences, All India Institute of Medical sciences, New Delhi, India
| | - Parijat Chandra
- Dept. Of Ophthalmology, Dr. Rajendra Prasad Center for Ophthalmic Sciences, All India Institute of Medical sciences, New Delhi, India
| | - Nabanita Halder
- Dept. Of Ocular pharmacology, Dr. Rajendra Prasad Center for Ophthalmic Sciences, All India Institute of Medical sciences, New Delhi, India
| | - Baskar Singh
- Dept. Of Biophysics, All India Institute of Medical sciences, New Delhi, India
| | - Ashok Kumar Deorari
- Dept. Of NICU, Pediatrics, All India Institute of Medical sciences, New Delhi, India
| | - Atul Kumar
- Dept. Of Ophthalmology, Dr. Rajendra Prasad Center for Ophthalmic Sciences, All India Institute of Medical sciences, New Delhi, India
| | - Rajvardhan Azad
- Dept. Of Ophthalmology, Dr. Rajendra Prasad Center for Ophthalmic Sciences, All India Institute of Medical sciences, New Delhi, India
| | - Thirumurthy Velpandian
- Dept. Of Ocular pharmacology, Dr. Rajendra Prasad Center for Ophthalmic Sciences, All India Institute of Medical sciences, New Delhi, India
- * E-mail:
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Renin-angiotensin system as a potential therapeutic target in stroke and retinopathy: experimental and clinical evidence. Clin Sci (Lond) 2016; 130:221-38. [PMID: 26769658 DOI: 10.1042/cs20150350] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
As our knowledge expands, it is now clear that the renin-angiotensin (Ang) system (RAS) mediates functions other than regulating blood pressure (BP). The RAS plays a central role in the pathophysiology of different neurovascular unit disorders including stroke and retinopathy. Moreover, the beneficial actions of RAS modulation in brain and retina have been documented in experimental research, but not yet exploited clinically. The RAS is a complex system with distinct yet interconnected components. Understanding the different RAS components and their functions under brain and retinal pathological conditions is crucial to reap their benefits. The aim of the present review is to provide an experimental and clinical update on the role of RAS in the pathophysiology and treatment of stroke and retinopathy. Combining the evidence from both these disorders allows a unique opportunity to move both fields forward.
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Pharmacology of the retinal pigment epithelium, the interface between retina and body system. Eur J Pharmacol 2016; 787:84-93. [PMID: 27044435 DOI: 10.1016/j.ejphar.2016.03.066] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 03/14/2016] [Accepted: 03/31/2016] [Indexed: 12/12/2022]
Abstract
The retinal pigment epithelium (RPE) is a close, interactive partner to the photoreceptors as well as an interface with the endothelium of the choroid and thus with the body's circulatory system. To fulfill these roles, the RPE communicates with neighboring tissue by secretion of a large variety of factors and is able to react to secreted factors via a plethora of transmembrane receptors. Clinically relevant local pharmacological effects are caused by anti-VEGF-A treatment in choroidal neovascularization or by carboanhydrase inhibitors reducing fluid accumulation in the macula. Being exposed to the bloodstream, the RPE reacts to systemic disease, such as diabetes or hypertension, but also to systemic pharmacological intervention, for example to hypotensive drugs acting on the renin-angiotensin-system. Sustained pharmacological treatments, in particular, cause side effects at the RPE with consequences for both RPE function and photoreceptor survival. Among these are systemic inhibition of angiotensin-converting enzyme, insulin treatment in diabetes and anti-VEGF-A therapy. Given the special anatomical and functional relationships of the RPE, pharmacological intervention targeting either the eye or the body systemically should take potential alteration of RPE and subsequently photoreceptor function into account.
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Hypertensive retinopathy in a transgenic angiotensin-based model. Clin Sci (Lond) 2016; 130:1075-88. [PMID: 27026533 DOI: 10.1042/cs20160092] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 03/29/2016] [Indexed: 12/18/2022]
Abstract
Severe hypertension destroys eyesight. The RAS (renin-angiotensin system) may contribute to this. This study relied on an established angiotensin, AngII (angiotensin II)-elevated dTGR (double-transgenic rat) model and same-background SD (Sprague-Dawley) rat controls. In dTGRs, plasma levels of AngII were increased. We determined the general retinal phenotype and observed degeneration of ganglion cells that we defined as vascular degeneration. We also inspected relevant gene expression and lastly observed alterations in the outer blood-retinal barrier. We found that both scotopic a-wave and b-wave as well as oscillatory potential amplitude were significantly decreased in dTGRs, compared with SD rat controls. However, the b/a-wave ratio remained unchanged. Fluorescence angiography of the peripheral retina indicated that exudates, or fluorescein leakage, from peripheral vessels were increased in dTGRs compared with controls. Immunohistological analysis of blood vessels in retina whole-mount preparations showed structural alterations in the retina of dTGRs. We then determined the general retinal phenotype. We observed the degeneration of ganglion cells, defined vascular degenerations and finally found differential expression of RAS-related genes and angiogenic genes. We found the expression of both human angiotensinogen and human renin in the hypertensive retina. Although the renin gene expression was not altered, the AngII levels in the retina were increased 4-fold in the dTGR retina compared with that in SD rats, a finding with mechanistic implications. We suggest that alterations in the outer blood-retinal barrier could foster an area of visual-related research based on our findings. Finally, we introduce the dTGR model of retinal disease.
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Zhu T, Miller AG, Deliyanti D, Berka DR, Agrotis A, Campbell DJ, Wilkinson-Berka JL. Prorenin stimulates a pro-angiogenic and pro-inflammatory response in retinal endothelial cells and an M1 phenotype in retinal microglia. Clin Exp Pharmacol Physiol 2016; 42:537-48. [PMID: 25707593 DOI: 10.1111/1440-1681.12376] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Revised: 01/29/2015] [Accepted: 02/12/2015] [Indexed: 01/25/2023]
Abstract
Angiogenesis and inflammation are causative factors in the development of neovascular retinopathies. These processes involve the retinal endothelium and the retinal immune cells, microglia. The renin-angiotensin system contributes to retinal injury via the actions of the type 1 angiotensin receptor (AT1R). However, it has been suggested that prorenin, the initiator of the renin-angiotensin system cascade, influences retinal injury independently from the AT1R. We evaluated whether prorenin induced a pro-angiogenic and pro-inflammatory response in retinal endothelial cells and a pro-inflammatory phenotype in retinal microglia. Primary cultures of retinal endothelial cells and microglia were studied. Rat recombinant prorenin (2 nmol/L) stimulated the proliferation and tubulogenesis of retinal endothelial cells; it increased the levels of pro-angiogenic factors, vascular endothelial growth factor, angiopoietin-1, and tyrosine kinase with immunoglobulin and epidermal growth factor homology domains, and pro-inflammatory factors, intercellular adhesion molecule-1 and monocyte chemoattractant protein-1, relative to the controls. The messenger RNA levels of the (pro)renin receptor were also increased. These effects occurred in the presence of the AT1R blocker candesartan (10 μmol/L) and the renin inhibitor aliskiren (10 μmol/L). Microglia, which express the (pro)renin receptor, elicited an activated phenotype when exposed to prorenin, which was characterized by increased levels of intercellular adhesion molecule-1, monocyte chemoattractant protein-1, tumour necrosis factor-α, interleukin-6, and interleukin-1β and by decreased levels of interleukin-10 and arginase-1 relative to controls. Candesartan did not influence the effects of prorenin on retinal microglia. In conclusion, prorenin has distinct pro-angiogenic and pro-inflammatory effects on retinal cells that are independent of the AT1R, indicating the potential importance of prorenin in retinopathy.
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Affiliation(s)
- Tong Zhu
- Department of Immunology and Pathology, Monash University, Melbourne, Vic., Australia
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Deliyanti D, Zhang Y, Khong F, Berka DR, Stapleton DI, Kelly DJ, Wilkinson-Berka JL. FT011, a Novel Cardiorenal Protective Drug, Reduces Inflammation, Gliosis and Vascular Injury in Rats with Diabetic Retinopathy. PLoS One 2015. [PMID: 26222724 PMCID: PMC4519240 DOI: 10.1371/journal.pone.0134392] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Diabetic retinopathy features inflammation as well as injury to glial cells and the microvasculature, which are influenced by hypertension and overactivity of the renin-angiotensin system. FT011 is an anti-inflammatory and anti-fibrotic agent that has been reported to attenuate organ damage in diabetic rats with cardiomyopathy and nephropathy. However, the potential therapeutic utility of FT011 for diabetic retinopathy has not been evaluated. We hypothesized that FT011 would attenuate retinopathy in diabetic Ren-2 rats, which exhibit hypertension due to an overactive extra-renal renin-angiotensin system. Diabetic rats were studied for 8 and 32 weeks and received intravitreal injections of FT011 (50 μM) or vehicle (0.9% NaCl). Comparisons were to age-matched controls. In the 8-week study, retinal inflammation was examined by quantitating vascular leukocyte adherence, microglial/macrophage density and the expression of inflammatory mediators. Macroglial Müller cells, which exhibit a pro-inflammatory and pro-angiogenic phenotype in diabetes, were evaluated in the 8-week study as well as in culture following exposure to hyperglycaemia and FT011 (10, 30, 100 μM) for 72 hours. In the 32-week study, severe retinal vasculopathy was examined by quantitating acellular capillaries and extracellular matrix proteins. In diabetic rats, FT011 reduced retinal leukostasis, microglial density and mRNA levels of intercellular adhesion molecule-1 (ICAM-1). In Müller cells, FT011 reduced diabetes-induced gliosis and vascular endothelial growth factor (VEGF) immunolabeling and the hyperglycaemic-induced increase in ICAM-1, monocyte chemoattractant protein-1, CCL20, cytokine-induced neutrophil chemoattractant-1, VEGF and IL-6. Late intervention with FT011 reduced acellular capillaries and the elevated mRNA levels of collagen IV and fibronectin in diabetic rats. In conclusion, the protective effects of FT011 in cardiorenal disease extend to key elements of diabetic retinopathy and highlight its potential as a treatment approach.
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Affiliation(s)
- Devy Deliyanti
- Department of Immunology and Pathology, Monash University, Melbourne, Victoria, Australia, 3004
| | - Yuan Zhang
- Department of Medicine, St Vincent’s Hospital, The University of Melbourne, Fitzroy, Victoria, Australia, 3065
| | - Fay Khong
- Department of Medicine, St Vincent’s Hospital, The University of Melbourne, Fitzroy, Victoria, Australia, 3065
| | - David R. Berka
- Department of Immunology and Pathology, Monash University, Melbourne, Victoria, Australia, 3004
| | - David I. Stapleton
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Victoria, Australia, 3052
| | - Darren J. Kelly
- Department of Medicine, St Vincent’s Hospital, The University of Melbourne, Fitzroy, Victoria, Australia, 3065
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Sherwin JC, Kokavec J, Thornton SN. Hydration, fluid regulation and the eye: in health and disease. Clin Exp Ophthalmol 2015; 43:749-64. [DOI: 10.1111/ceo.12546] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Accepted: 04/30/2015] [Indexed: 12/01/2022]
Affiliation(s)
- Justin C Sherwin
- Royal Victorian Eye and Ear Hospital; Melbourne Victoria Australia
- Lions Eye Institute; University of Western Australia; Centre for Ophthalmology and Visual Science; Perth Western Australia Australia
| | - Jan Kokavec
- South Australian Institute of Ophthalmology; Royal Adelaide Hospital; Adelaide South Australia Australia
| | - Simon N Thornton
- Université de Lorraine; Nancy France
- INSERM U1116; Vandoeuvre les Nancy France
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25
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Haque R, Hur EH, Farrell AN, Iuvone PM, Howell JC. MicroRNA-152 represses VEGF and TGFβ1 expressions through post-transcriptional inhibition of (Pro)renin receptor in human retinal endothelial cells. Mol Vis 2015; 21:224-35. [PMID: 25802486 PMCID: PMC4358229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 03/05/2015] [Indexed: 11/01/2022] Open
Abstract
PURPOSE The (pro)renin receptor (PRR), a component of the renin-angiotensin system (RAS), plays an important role in the physiologic and pathophysiological regulation of blood pressure and fluid/electrolyte homeostasis. The RAS including the PRR has been identified in retinal endothelial cells and other ocular tissues. In this study, the potential involvement of miRNAs in the posttranscriptional regulation of PRR was investigated in human retinal endothelial cells (hRECs) under high glucose (HG) conditions. METHODS miRNA-152 (miR-152) was identified in silico as a potential regulator of PRR, and this was confirmed by quantitative real-time PCR (qRT-PCR) and PRR 3'-untranslated region (UTR) reporter assays. Using RNA interference, both AT1R and PRR were implicated in the HG-mediated induction of vascular endothelial growth factor (VEGF), VEGF receptor 2 (VEGFR-2), and transforming growth factor β1 (TGFβ1). RESULTS The downregulation of miR-152 was observed in hRECs and rat retinal tissues under HG conditions. In parallel, PRR (target of miR-152), VEGF, VEGFR-2, and TGFβ1 at mRNA levels were elevated. However, the transfection of hRECs with miR-152 mimics in HG conditions resulted in the suppression of the PRR expression, as well as reduced VEGF, VEGFR-2, and TGFβ1 production. This was reversed by transfecting cells with the antisense (antagomir) of miR-152, suggesting the glucose-induced upregulation of VEGF, VEGFR-2, and TGFβ1 is mediated through PRR, and this regulation is likely achieved through the HG-mediated modulation of miRNAs. CONCLUSIONS We have demonstrated that miR-152 interacting with PRR regulates downstream VEGF, VRGFR-2, and TGFβ1 expressions in hRECs in HG conditions. These studies suggest miR-152 and PRR may play a role in the pathogenesis of diabetic retinopathy (DR).
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Batenburg WW, Verma A, Wang Y, Zhu P, van den Heuvel M, van Veghel R, Danser AHJ, Li Q. Combined renin inhibition/(pro)renin receptor blockade in diabetic retinopathy--a study in transgenic (mREN2)27 rats. PLoS One 2014; 9:e100954. [PMID: 24968134 PMCID: PMC4072720 DOI: 10.1371/journal.pone.0100954] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 05/31/2014] [Indexed: 12/20/2022] Open
Abstract
Dysfunction of renin-angiotensin system (RAS) contributes to the pathogenesis of diabetic retinopathy (DR). Prorenin, the precursor of renin is highly elevated in ocular fluid of diabetic patients with proliferative retinopathy. Prorenin may exert local effects in the eye by binding to the so-called (pro)renin receptor ((P)RR). Here we investigated the combined effects of the renin inhibitor aliskiren and the putative (P)RR blocker handle-region peptide (HRP) on diabetic retinopathy in streptozotocin (STZ)-induced diabetic transgenic (mRen2)27 rats (a model with high plasma prorenin levels) as well as prorenin stimulated cytokine expression in cultured Müller cells. Adult (mRen2)27 rats were randomly divided into the following groups: (1) non-diabetic; (2) diabetic treated with vehicle; (3) diabetic treated with aliskiren (10 mg/kg per day); and (4) diabetic treated with aliskiren+HRP (1 mg/kg per day). Age-matched non-diabetic wildtype Sprague-Dawley rats were used as control. Drugs were administered by osmotic minipumps for three weeks. Transgenic (mRen2)27 rat retinas showed increased apoptotic cell death of both inner retinal neurons and photoreceptors, increased loss of capillaries, as well as increased expression of inflammatory cytokines. These pathological changes were further exacerbated by diabetes. Aliskiren treatment of diabetic (mRen2)27 rats prevented retinal gliosis, and reduced retinal apoptotic cell death, acellular capillaries and the expression of inflammatory cytokines. HRP on top of aliskiren did not provide additional protection. In cultured Müller cells, prorenin significantly increased the expression levels of IL-1α and TNF-α, and this was completely blocked by aliskiren or HRP, their combination, (P)RR siRNA and the AT1R blocker losartan, suggesting that these effects entirely depended on Ang II generation by (P)RR-bound prorenin. In conclusion, the lack of effect of HRP on top of aliskiren, and the Ang II-dependency of the ocular effects of prorenin in vitro, argue against the combined application of (P)RR blockade and renin inhibition in diabetic retinopathy.
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Affiliation(s)
- Wendy W. Batenburg
- Division of Pharmacology, Vascular and Metabolic Diseases, Department of Internal Medicine, rasmus MC, GE Rotterdam, The Netherlands
| | - Amrisha Verma
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Yunyang Wang
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Ping Zhu
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Mieke van den Heuvel
- Division of Pharmacology, Vascular and Metabolic Diseases, Department of Internal Medicine, rasmus MC, GE Rotterdam, The Netherlands
| | - Richard van Veghel
- Division of Pharmacology, Vascular and Metabolic Diseases, Department of Internal Medicine, rasmus MC, GE Rotterdam, The Netherlands
| | - A. H. Jan Danser
- Division of Pharmacology, Vascular and Metabolic Diseases, Department of Internal Medicine, rasmus MC, GE Rotterdam, The Netherlands
| | - Qiuhong Li
- Department of Ophthalmology, College of Medicine, University of Florida, Gainesville, Florida, United States of America
- * E-mail:
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Connelly KA, Zhang Y, Advani A, Advani SL, Thai K, Yuen DA, Gilbert RE. DPP-4 inhibition attenuates cardiac dysfunction and adverse remodeling following myocardial infarction in rats with experimental diabetes. Cardiovasc Ther 2014; 31:259-67. [PMID: 22963483 DOI: 10.1111/1755-5922.12005] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
AIMS Following myocardial infarction (MI), individuals with diabetes have a two-fold increase in the risk of heart failure, due in part to excessive loss of cardiac microvasculature. Endothelial integrity and restitution are mediated in part by stromal cell-derived factor-1α (SDF-1α), a chemokine that is elaborated by ischemic tissue but rapidly degraded by dipeptidyl peptidase-4 (DPP-4). Accordingly, we hypothesized that inhibiting this enzyme may confer benefit following myocardial infarction in the diabetic setting beyond its effect on glycemia. METHODS AND RESULTS Fischer F344 rats with streptozotocin (STZ)-diabetes were randomized to receive vehicle or the DPP-4 inhibitor, sitagliptin (300 mg/kg/day). Two weeks later, animals underwent experimental MI, induced by ligation of the left anterior descending coronary artery. Cardiac function was assessed by conductance catheterization and echocardiography along with cardiac structure 4 weeks post-MI. Following MI, untreated diabetic rats developed both systolic and diastolic cardiac dysfunction, in association with endothelial cell loss, fibrosis, and myocyte hypertrophy. Without affecting plasma glucose, sitagliptin treatment led to an improvement in passive left ventricular compliance, increased endothelial cell density, reduced myocyte hypertrophy, and a reduction in the abundance of collagen 1 (all P < 0.05). Systolic function was unchanged. CONCLUSIONS This study shows that DPP-4 inhibition attenuates several, but not all, aspects of cardiac dysfunction and adverse remodeling in the post-MI setting.
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Affiliation(s)
- Kim Alexander Connelly
- Keenan Research Centre of the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada
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Giese MJ, Speth RC. The ocular renin-angiotensin system: a therapeutic target for the treatment of ocular disease. Pharmacol Ther 2013; 142:11-32. [PMID: 24287313 DOI: 10.1016/j.pharmthera.2013.11.002] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2013] [Accepted: 10/25/2013] [Indexed: 02/06/2023]
Abstract
The renin-angiotensin system (RAS) is most well-known for its role in regulation and dysregulation of blood pressure as well as fluid and electrolyte homeostasis. Due to its ability to cause cardiovascular disease, the RAS is the target of a multitude of drugs that antagonize its pathophysiological effects. While the "classical" RAS is a systemic hormonal system, there is an increasing awareness of the existence and functional significance of local RASs in a number of organs, e.g., liver, kidney, heart, lungs, reproductive organs, adipose tissue and adrenal. The eye is one of these organs where a compelling body of evidence has demonstrated the presence of a local RAS. Individual components of the RAS have been shown to be present in many structures of the eye and their potential functional significance in ocular disease states is described. Because the eye is one of the most important and complex organs in the body, this review also discusses the implications of dysregulation of the systemic RAS on the pathogenesis of ocular diseases and how pharmacological manipulation of the RAS might lead to novel or adjunctive therapies for ocular disease states.
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Affiliation(s)
| | - Robert C Speth
- Department of Pharmaceutical Sciences, College of Pharmacy, Nova Southeastern University, Fort Lauderdale, FL 33328, United States.
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The (pro)renin receptor blocker handle region peptide upregulates endothelium-derived contractile factors in aliskiren-treated diabetic transgenic (mREN2)27 rats. J Hypertens 2013; 31:292-302. [PMID: 23303354 DOI: 10.1097/hjh.0b013e32835c1789] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
BACKGROUND Elevated prorenin levels associate with microvascular complications in patients with diabetes mellitus, possibly because prorenin affects vascular function in diabetes mellitus, for example by generating angiotensins following its binding to the (pro)renin receptor [(P)RR]. Here we evaluated whether the renin inhibitor aliskiren, with or without the putative (P)RR antagonist handle region peptide (HRP) improved the disturbed vascular function in diabetic TGR(mREN2)27 rats, a high-prorenin, high-(P)RR hypertensive model. METHODS Telemetry transmitters were implanted to monitor blood pressure. After 3 weeks of treatment, rats were sacrificed, and iliac and mesenteric arteries were removed to evaluate vascular reactivity. RESULTS Diabetes mellitus enhanced the contractile response to nitric oxide synthase (NOS) blockade, potentiated the response to phenylephrine, diminished the effectiveness of endothelin type A (ETA) receptor blockade and allowed acetylcholine to display constrictor, cyclo-oxygenase-2 mediated, endothelium-dependent responses in the presence of NOS inhibition and blockers of endothelium-derived hyperpolarizing factors. Aliskiren normalized blood pressure, suppressed renin activity, and reversed the above vascular effects, with the exception of the altered effectiveness of ETA receptor blockade. Remarkably, when adding HRP on top of aliskiren, its beneficial vascular effects either disappeared or were greatly diminished, although HRP did not alter the effect of aliskiren on blood pressure and renin activity. CONCLUSIONS Renin inhibition improves vascular dysfunction in diabetic hypertensive rats, and HRP counteracts this effect independently of blood pressure and angiotensin. (P)RR blockade therefore is unlikely to be a new tool to further suppress the renin-angiotensin system (RAS) on top of existing RAS blockers.
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Abstract
Oxidative stress has been linked to the pathogenesis of the major complications of diabetes in the kidney, the heart, the eye or the vasculature. NADPH oxidases of the Nox family are a major source of ROS (reactive oxygen species) and are critical mediators of redox signalling in cells from different organs afflicted by the diabetic milieu. In the present review, we provide an overview of the current knowledge related to the understanding of the role of Nox in the processes that control cell injury induced by hyperglycaemia and other predominant factors enhanced in diabetes, including the renin–angiotensin system, TGF-β (transforming growth factor-β) and AGEs (advanced glycation end-products). These observations support a critical role for Nox homologues in diabetic complications and indicate that NADPH oxidases are an important therapeutic target. Therefore the design and development of small-molecule inhibitors that selectively block Nox oxidases appears to be a reasonable approach to prevent or retard the complications of diabetes in target organs. The bioefficacy of these agents in experimental animal models is also discussed in the present review.
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Li H, Wang YS. An angiotensin-converting enzyme inhibitor modulates stromal-derived factor-1 through CD26/dipeptidyl peptidase IV to inhibit laser-induced choroidal neovascularization. Mol Vis 2013; 19:1107-21. [PMID: 23734079 PMCID: PMC3669532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2012] [Accepted: 05/27/2013] [Indexed: 11/29/2022] Open
Abstract
PURPOSE Stromal-derived factor (SDF)-1 is a chemokine that recruits bone marrow-derived endothelial precursor cells (EPCs) for choroidal neovascularization (CNV) development. Angiotensin-converting enzyme (ACE) inhibitors mediate the compensatory effects of ACE and CD26/dipeptidyl peptidase IV (DPP IV), which results in the degradation and inactivation of SDF-1 in vivo. ACE inhibitors, such as imidapril, exhibit potential antiangiogenic effects on laser-induced CNV in mice. The role that this imidapril-mediated effect plays in modulating SDF-1 signals has not been defined. The present study assessed the effect of the CD26/SDF-1 signaling pathway on the inhibitory effect of imidapril in CNV development. METHODS CNV was induced in C57BL/6J mice by focally rupturing Bruch's membrane using a 532-nm diode laser. The animals were pretreated with PBS, imidapril, diprotin-A (a DPP IV antagonist), or imidapril plus diprotin-A for 5 days before photocoagulation. Treatments were continued daily for 14 days following the laser induction. The normal control group did not undergo laser rupture or receive treatment. CD26 activity was measured using a substrate conversion assay and flow cytometry. SDF-1 levels in both the blood and the bone marrow were measured using an enzyme-linked immunosorbent assay, and the number of circulating endothelial progenitor cells (EPCs) and leukocytes was quantified. Functional analyses of circulating SDF-1 were performed using actin polymerization blood biomarker assays, and the CNV-related responses were evaluated using fluorescein angiography and isolectin-B4-labeled flatmounts. RESULTS Imidapril directly amplified CD26 activity and had a minor effect on the number of CD26+ cells in the bone marrow. However, decreased CD26 activity in the plasma was secondary to a decrease in the number of circulating CD26+ cells and blood leukocytes. Furthermore, imidapril increased SDF-1 concentrations in the peripheral circulation via CD26-induced degradation of SDF-1 in the bone marrow, an effect that coincided with elevated numbers of circulating EPCs. CD26-mediated SDF-1 inactivation was demonstrated by a decrease in SDF-1-induced actin polymerization in the whole blood of imidapril-treated mice. Imidapril markedly decreased angiographic leakage and CNV size. CD26 inhibition completely blocked the CD26/SDF-1 signaling pathway in vivo and reduced the antiangiogenic effect of imidapril. CONCLUSIONS These results strongly suggest that the antiangiogenic effects of imidapril on laser-induced CNV partially involve the modulation of the CD26/SDF-1 signaling pathway.
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Affiliation(s)
- Hong Li
- Department of Ophthalmology, Eye Institute of Chinese PLA, Xijing Hospital, Fourth Military Medical University, Xi’an, PR China,Department of ophthalmology, General Hospital of Lanzhou military command, Lan’zhou, PR China
| | - Yu-sheng Wang
- Department of Ophthalmology, Eye Institute of Chinese PLA, Xijing Hospital, Fourth Military Medical University, Xi’an, PR China
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Reactive oxygen species, Nox and angiotensin II in angiogenesis: implications for retinopathy. Clin Sci (Lond) 2013; 124:597-615. [PMID: 23379642 DOI: 10.1042/cs20120212] [Citation(s) in RCA: 105] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Pathological angiogenesis is a key feature of many diseases including retinopathies such as ROP (retinopathy of prematurity) and DR (diabetic retinopathy). There is considerable evidence that increased production of ROS (reactive oxygen species) in the retina participates in retinal angiogenesis, although the mechanisms by which this occurs are not fully understood. ROS is produced by a number of pathways, including the mitochondrial electron transport chain, cytochrome P450, xanthine oxidase and uncoupled nitric oxide synthase. The family of NADPH oxidase (Nox) enzymes are likely to be important given that their primary function is to produce ROS. Seven isoforms of Nox have been identified named Nox1-5, Duox (dual oxidase) 1 and Duox2. Nox1, Nox2 and Nox4 have been most extensively studied and are implicated in the development of conditions such as hypertension, cardiovascular disease and diabetic nephropathy. In recent years, evidence has accumulated to suggest that Nox1, Nox2 and Nox4 participate in pathological angiogenesis; however, there is no clear consensus about which Nox isoform is primarily responsible. In terms of retinopathy, there is growing evidence that Nox contribute to vascular injury. The RAAS (renin-angiotensin-aldosterone system), and particularly AngII (angiotensin II), is a key stimulator of Nox. It is known that a local RAAS exists in the retina and that blockade of AngII and aldosterone attenuate pathological angiogenesis in the retina. Whether the RAAS influences the production of ROS derived from Nox in retinopathy is yet to be fully determined. These topics will be reviewed with a particular emphasis on ROP and DR.
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Miao X, Lv H, Wang B, Chen Q, Miao L, Su G, Tan Y. Deletion of angiotensin II type 1 receptor gene attenuates chronic alcohol-induced retinal ganglion cell death with preservation of VEGF expression. Curr Eye Res 2012; 38:185-93. [PMID: 22954336 DOI: 10.3109/02713683.2012.720339] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
PURPOSE To investigate how chronic alcohol consumption affects adult visual nervous system and whether renin-angiotensin system (RAS) is involved in this pathogenic process. METHODS Male transgenic mice with angiotensin II (Ang II) type 1 (AT1) receptor gene knockout (AT1-KO) and age-matched wild-type (WT) mice were pair-fed a modified Lieber-DeCarli alcohol or isocaloric maltose dextrin control liquid diet for 2 months. At the end of the study, retinas were harvested and subjected to histopathological and immunohistochemical examination. RESULTS We found that chronic alcohol consumption significantly increased retinal ganglion cell (RGC) apoptosis in the retina of WT mice, but not AT1-KO mice, detected by terminal deoxynucleotidyl-transferase-mediated dUTP-nick-end labeling staining and caspase 3 activation, along with an up-regulation of AT1 expression in RGC. At the same time, the phosphorylation of P53 in RGCs was significantly increased for both WT and AT1-KO mice exposed to alcohol, which could be significantly, although partially, prevented by AT1 gene deletion. We further examined the expression of vascular endothelial growth factor (VEGF) and CD31, and found that alcohol treatment significantly decreased the expression of VEGF and CD31 in RGCs of WT mice, but not AT1-KO mice. CONCLUSION Taken together, our study demonstrates that the induction of RGC apoptosis by chronic alcohol exposure may be related to p53-activation and VEGF depression, all which are partially dependent of AT1 receptor activation.
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Affiliation(s)
- Xiao Miao
- Department of Ophthalmology, Second Hospital of Jilin University, Changchun, China
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Wilkinson-Berka JL, Agrotis A, Deliyanti D. The retinal renin-angiotensin system: roles of angiotensin II and aldosterone. Peptides 2012; 36:142-50. [PMID: 22537944 DOI: 10.1016/j.peptides.2012.04.008] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2012] [Revised: 04/10/2012] [Accepted: 04/10/2012] [Indexed: 01/29/2023]
Abstract
In the present review we examine the experimental and clinical evidence for the presence of a local renin-angiotensin system within the retina. Interest in a pathogenic role for the renin-angiotensin system in retinal disease originally stemmed from observations that components of the pathway were elevated in retina during the development of certain retinal pathologies. Since then, our knowledge about the contribution of the RAS to retinal disease has greatly expanded. We discuss the known functions of the renin-angiotensin system in retinopathy of prematurity and diabetic retinopathy. This includes the promotion of retinal neovascularization, inflammation, oxidative stress and neuronal and glial dysfunction. The contribution of specific components of the renin-angiotensin system is evaluated with a particular focus on angiotensin II and aldosterone and their cognate receptors. The therapeutic utility of inhibiting key components of the renin-angiotensin system is complex, but may hold promise for the prevention and improvement of vision threatening diseases.
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Renin-Angiotensin system hyperactivation can induce inflammation and retinal neural dysfunction. Int J Inflam 2012; 2012:581695. [PMID: 22536545 PMCID: PMC3321303 DOI: 10.1155/2012/581695] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2011] [Revised: 12/09/2011] [Accepted: 01/04/2012] [Indexed: 12/21/2022] Open
Abstract
The renin-angiotensin system (RAS) is a hormone system that has been classically known as a blood pressure regulator but is becoming well recognized as a proinflammatory mediator. In many diverse tissues, RAS pathway elements are also produced intrinsically, making it possible for tissues to respond more dynamically to systemic or local cues. While RAS is important for controlling normal inflammatory responses, hyperactivation of the pathway can cause neural dysfunction by inducing accelerated degradation of some neuronal proteins such as synaptophysin and by activating pathological glial responses. Chronic inflammation and oxidative stress are risk factors for high incidence vision-threatening diseases such as diabetic retinopathy (DR), age-related macular degeneration (AMD), and glaucoma. In fact, increasing evidence suggests that RAS inhibition may actually prevent progression of various ocular diseases including uveitis, DR, AMD, and glaucoma. Therefore, RAS inhibition may be a promising therapeutic approach to fine-tune inflammatory responses and to prevent or treat certain ocular and neurodegenerative diseases.
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36
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Carbajo-Lozoya J, Lutz S, Feng Y, Kroll J, Hammes HP, Wieland T. Angiotensin II modulates VEGF-driven angiogenesis by opposing effects of type 1 and type 2 receptor stimulation in the microvascular endothelium. Cell Signal 2012; 24:1261-9. [PMID: 22374305 DOI: 10.1016/j.cellsig.2012.02.005] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Revised: 02/14/2012] [Accepted: 02/14/2012] [Indexed: 11/19/2022]
Abstract
Vascular endothelial growth factor (VEGF) is a main stimulator of pathological vessel formation. Nevertheless, increasing evidence suggests that Angiotensin II (Ang II) can play an augmentory role in this process. We thus analyzed the contribution of the two Ang II receptor types, AT(1)R and AT(2)R, in a mouse model of VEGF-driven angiogenesis, i.e. oxygen-induced proliferative retinopathy. Application of the AT(1)R antagonist telmisartan but not the AT(2)R antagonist PD123,319 largely attenuated the pathological response. A direct effect of Ang II on endothelial cells (EC) was analyzed by assessing angiogenic responses in primary bovine retinal and immortalized rat microvascular EC. Selective stimulation of the AT(1)R by Ang II in the presence of PD123,319 revealed a pro-angiogenic activity which further increased VEGF-driven EC sprouting and migration. In contrast, selective stimulation of the AT(2)R by either CGP42112A or Ang II in the presence of telmisartan inhibited the VEGF-driven angiogenic response. Using specific inhibitors (pertussis toxin, RGS proteins, kinase inhibitors) we identified G(12/13) and G(i) dependent signaling pathways as the mediators of the AT(1)R-induced angiogenesis and the AT(2)R-induced inhibition, respectively. As AT(1)R and AT(2)R stimulation displays opposing effects on the activity of the monomeric GTPase RhoA and pro-angiogenic responses to Ang II and VEGF requires activation of Rho-dependent kinase (ROCK), we conclude that the opposing effects of the Ang II receptors on VEGF-driven angiogenesis converge on the regulation of activity of RhoA-ROCK-dependent EC migration.
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MESH Headings
- Angiotensin II/metabolism
- Angiotensin Receptor Antagonists/pharmacology
- Animals
- Cattle
- Cell Movement
- Cells, Cultured
- Endothelial Cells/cytology
- Endothelial Cells/metabolism
- Endothelium, Vascular/cytology
- Endothelium, Vascular/growth & development
- Endothelium, Vascular/metabolism
- GTP-Binding Protein alpha Subunits, G12-G13/metabolism
- Mice
- Mice, Inbred C57BL
- Microvessels/cytology
- Microvessels/growth & development
- Microvessels/metabolism
- Neovascularization, Pathologic
- Neovascularization, Physiologic
- Rats
- Receptor, Angiotensin, Type 1/metabolism
- Receptor, Angiotensin, Type 2/metabolism
- Retina/pathology
- Retina/ultrastructure
- Vascular Endothelial Growth Factor A/metabolism
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Affiliation(s)
- Javier Carbajo-Lozoya
- Institute of Experimental and Clinical Pharmacology and Toxicology, Medical Faculty Mannheim, University of Heidelberg, Maybachstrasse 14, D-68169 Mannheim, Germany
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Deliyanti D, Miller AG, Tan G, Binger KJ, Samson AL, Wilkinson-Berka JL. Neovascularization is attenuated with aldosterone synthase inhibition in rats with retinopathy. Hypertension 2012; 59:607-13. [PMID: 22275532 DOI: 10.1161/hypertensionaha.111.188136] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Neovascularization is a hallmark feature of retinopathy of prematurity and diabetic retinopathy. Type 1 angiotensin receptor blockade reduces neovascularization in experimental retinopathy of prematurity, known as oxygen-induced retinopathy (OIR). We investigated in OIR whether inhibiting aldosterone with the aldosterone synthase inhibitor FAD286 reduced neovascularization as effectively as angiotensin receptor blockade (valsartan). OIR was induced in neonatal Sprague-Dawley rats, and they were treated with FAD286 (30 mg/kg per day), valsartan (10 mg/kg per day), or FAD286+valsartan. The cellular sources of aldosterone synthase, the mineralocorticoid receptor, and 11β-hydroxysteroid dehydrogenase 2 were evaluated in retinal cells involved in neovascularization (primary endothelial cells, pericytes, microglia, ganglion cells, and glia). In OIR, FAD286 reduced neovascularization and neovascular tufts by 89% and 67%, respectively, and normalized the increase in vascular endothelial growth factor mRNA (1.74-fold) and protein (4.74-fold) and was as effective as valsartan and FAD286+valsartan. In retina, aldosterone synthase mRNA was reduced with FAD286 but not valsartan. Aldosterone synthase was detected in microglia, ganglion cells, and glia, whereas mineralocorticoid receptor and 11β-hydroxysteroid dehydrogenase 2 were present in all of the cell types studied. Given the location of aldosterone synthase in microglia and their contribution to retinal inflammation and neovascularization in OIR, the effects of FAD286 on microglial density were studied. The increase in microglial density (ionized calcium binding adaptor protein 1 immunolabeling) in OIR was reduced with all of the treatments. In OIR, FAD286 reduced the increase in mRNA for tumor necrosis factor-α, intercellular adhesion molecule 1, vascular cell adhesion molecule 1, and monocyte chemoattractant molecule 1. These findings indicate that aldosterone inhibition may be a potential treatment for retinal neovascularization.
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Affiliation(s)
- Devy Deliyanti
- Department of Immunology, Monash University, Alfred Medical Research and Education Precinct, Melbourne, Victoria, Australia
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Li H, Yan Z, Cao H, Wang Y. Effective mobilisation of bone marrow-derived cells through proteolytic activity: a new treatment strategy for age-related macular degeneration. Med Hypotheses 2011; 78:286-90. [PMID: 22129485 DOI: 10.1016/j.mehy.2011.11.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2011] [Revised: 10/16/2011] [Accepted: 11/08/2011] [Indexed: 12/12/2022]
Abstract
Selective targeting of bone marrow-derived cells (BMCs) has been heralded as a promising avenue for age-related macular degeneration (AMD) therapeutics. Many researchers have demonstrated that the function of circulating BMCs is related to disease severity in patients with AMD. Transplanted BMCs are able to transdifferentiate into retina-specific cells to replace those lost due to damage or degeneration in the pathologic process of experimental models of AMD, which may provide beneficial effects in patients with AMD. However, a major barrier to transferring the use of BMCs into clinical practice is the limited quantity of BMCs in the peripheral circulation. Technology has not yet reached a stage where ex vivo-expanded BMCs can be routinely used for cell therapy. A feasible strategy to circumvent this issue of BMC scarcity is to increase the mobilisation of autologous BMCs from the patient's bone marrow into the blood circulation. Extensive studies have demonstrated that the SDF-1/CXCR4 axis is a key regulator for BMC mobilisation. Moreover, abrogation of the SDF-1/CXCR4 axis by proteolytic modification can efficiently increase BMC mobilisation. We speculate that BMC mobilisation by proteolytic enzymes may supply a sufficient amount of autologous cells to repair and regenerate injured and degenerated the retinal pigment epithelium (RPE), photoreceptors, or other retina-specific cells, which could prevent AMD progression. If the BMC mobilisation strategy is used to treat AMD, it may overcome the existing problems of transferring BMC-based therapy into the clinic and become a particularly feasible therapeutic approach for AMD.
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Affiliation(s)
- Hong Li
- Department of Ophthalmology, Eye Institute of Chinese PLA, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, PR China
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Wilkinson-Berka JL, Tan G, Binger KJ, Sutton L, McMaster K, Deliyanti D, Perera G, Campbell DJ, Miller AG. Aliskiren reduces vascular pathology in diabetic retinopathy and oxygen-induced retinopathy in the transgenic (mRen-2)27 rat. Diabetologia 2011; 54:2724-35. [PMID: 21755314 DOI: 10.1007/s00125-011-2239-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Accepted: 06/13/2011] [Indexed: 10/18/2022]
Abstract
AIM/HYPOTHESIS We examined whether the renin inhibitor, aliskiren, provides similar or greater protection than ACE inhibition from non-proliferative diabetic retinopathy and from the proliferative neoangiogenesis of oxygen-induced retinopathy. METHODS Transgenic (mRen-2)27 rats, which overexpress mouse renin and angiotensin in extra-renal tissues, were studied. For diabetic studies, non-diabetic, diabetic (streptozotocin, 55 mg/kg), diabetic + aliskiren (10 mg kg(-1) day(-1), pump), or diabetic + lisinopril (10 mg kg(-1) day(-1), drinking water) rats were evaluated over 16 weeks. For oxygen-induced retinopathy studies, rats were exposed to 80% oxygen (22 h/day) from postnatal days 0 to 11, and then room air from postnatal days 12 to 18. Aliskiren (10 or 30 mg kg(-1) day(-1), pump) or lisinopril (10 mg kg(-1) day(-1), drinking water) was administered during retinopathy development between postnatal days 12 and 18. RESULTS Systolic BP in diabetic (mRen-2)27 rats was reduced with 10 mg kg(-1) day(-1) aliskiren, but only lisinopril normalised systolic blood pressure. In diabetic (mRen-2)27 rats, 10 mg kg(-1) day(-1) aliskiren and lisinopril reduced retinal acellular capillaries and leucostasis to non-diabetic levels. In oxygen-induced retinopathy, neoangiogenesis and retinal inflammation (leucostasis, ED-1 immunolabelling) were partially reduced by 10 mg kg(-1) day(-1) aliskiren and normalised by 30 mg kg(-1) day(-1) aliskiren, whereas lisinopril normalised neoangiogenesis and reduced leucostasis and ED-1 immunolabelling. Aliskiren and lisinopril normalised retinal vascular endothelial growth factor expression; however, only aliskiren reduced intercellular adhesion molecule-1 to control levels. CONCLUSIONS/INTERPRETATION Aliskiren provided similar or greater retinal protection than ACE inhibition and may be a potential treatment for diabetic retinopathy.
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Affiliation(s)
- J L Wilkinson-Berka
- Department of Immunology, Monash University, Alfred Medical Research and Education Precinct (AMREP), Commercial Road, Melbourne, 3004 Victoria, Australia.
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Verma A, Shan Z, Lei B, Yuan L, Liu X, Nakagawa T, Grant MB, Lewin AS, Hauswirth WW, Raizada MK, Li Q. ACE2 and Ang-(1-7) confer protection against development of diabetic retinopathy. Mol Ther 2011; 20:28-36. [PMID: 21792177 DOI: 10.1038/mt.2011.155] [Citation(s) in RCA: 128] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Despite evidence that hyperactivity of the vasodeleterious axis (ACE/angiotensin II (Ang II)/AT1 receptor) of the renin-angiotensin system (RAS) is associated with the pathogenesis of diabetic retinopathy (DR) use of the inhibitors of this axis has met with limited success in the control of this pathophysiology. We investigated the hypothesis that enhancing the local activity of the recently established protective axis of the RAS, ACE2/Ang-(1-7), using adeno-associated virus (AAV)-mediated gene delivery of ACE2 or Ang-(1-7) would confer protection against diabetes-induced retinopathy. Genes expressing ACE2 and Ang-(1-7) were cloned in AAV vector. The effects of ocular AAV-ACE2/Ang-(1-7) gene transfer on DR in diabetic eNOS(-/-) mice and Sprague-Dawley (SD) rats were examined. Diabetes was associated with approximately tenfold and greater than threefold increases in the ratios of ACE/ACE2 and AT1R/Mas mRNA levels in the retina respectively. Intraocular administration of AAV-ACE2/Ang-(1-7) resulted in significant reduction in diabetes-induced retinal vascular leakage, acellular capillaries, infiltrating inflammatory cells and oxidative damage in both diabetic mice and rats. Our results demonstrate that DR is associated with impaired balance of retinal RAS. Increased expression of ACE2/Ang-(1-7) overcomes this imbalance and confers protection against DR. Thus, strategies enhancing the protective ACE2/Ang-(1-7) axis of RAS in the eye could serve as a novel therapeutic target for DR.
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Affiliation(s)
- Amrisha Verma
- Department of Ophthalmology, University of Florida, Gainesville, Florida 32610-0284, USA
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Prorenin and the (pro)renin receptor: recent advances and implications for retinal development and disease. Curr Opin Nephrol Hypertens 2011; 20:69-76. [DOI: 10.1097/mnh.0b013e328341328a] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Fletcher EL, Jobling AI, Vessey KA, Luu C, Guymer RH, Baird PN. Animal models of retinal disease. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2011; 100:211-86. [PMID: 21377628 DOI: 10.1016/b978-0-12-384878-9.00006-6] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Diseases of the retina are the leading causes of blindness in the industrialized world. The recognition that animals develop retinal diseases with similar traits to humans has led to not only a dramatic improvement in our understanding of the pathogenesis of retinal disease but also provided a means for testing possible treatment regimes and successful gene therapy trials. With the advent of genetic and molecular biological tools, the association between specific gene mutations and retinal signs has been made. Animals carrying natural mutations usually in one gene now provide well-established models for a host of inherited retinal diseases, including retinitis pigmentosa, Leber congenital amaurosis, inherited macular degeneration, and optic nerve diseases. In addition, the development of transgenic technologies has provided a means by which to study the effects of these and novel induced mutations on retinal structure and function. Despite these advances, there is a paucity of suitable animal models for complex diseases, including age-related macular degeneration (AMD) and diabetic retinopathy, largely because these diseases are not caused by single gene defects, but involve complex genetics and/or exacerbation through environmental factors, epigenetic, or other modes of genetic influence. In this review, we outline in detail the available animal models for inherited retinal diseases and how this information has furthered our understanding of retinal diseases. We also examine how transgenic technologies have helped to develop our understanding of the role of isolated genes or pathways in complex diseases like AMD, diabetes, and glaucoma.
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Affiliation(s)
- Erica L Fletcher
- Department of Anatomy and Cell Biology, The University of Melbourne, Parkville, Victoria, Australia
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Miller AG, Tan G, Binger KJ, Pickering RJ, Thomas MC, Nagaraj RH, Cooper ME, Wilkinson-Berka JL. Candesartan attenuates diabetic retinal vascular pathology by restoring glyoxalase-I function. Diabetes 2010; 59:3208-15. [PMID: 20852029 PMCID: PMC2992784 DOI: 10.2337/db10-0552] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE Advanced glycation end products (AGEs) and the renin-angiotensin system (RAS) are both implicated in the development of diabetic retinopathy. How these pathways interact to promote retinal vasculopathy is not fully understood. Glyoxalase-I (GLO-I) is an enzyme critical for the detoxification of AGEs and retinal vascular cell survival. We hypothesized that, in retina, angiotensin II (Ang II) downregulates GLO-I, which leads to an increase in methylglyoxal-AGE formation. The angiotensin type 1 receptor blocker, candesartan, rectifies this imbalance and protects against retinal vasculopathy. RESEARCH DESIGN AND METHODS Cultured bovine retinal endothelial cells (BREC) and bovine retinal pericytes (BRP) were incubated with Ang II (100 nmol/l) or Ang II+candesartan (1 μmol/l). Transgenic Ren-2 rats that overexpress the RAS were randomized to be nondiabetic, diabetic, or diabetic+candesartan (5 mg/kg/day) and studied over 20 weeks. Comparisons were made with diabetic Sprague-Dawley rats. RESULTS In BREC and BRP, Ang II induced apoptosis and reduced GLO-I activity and mRNA, with a concomitant increase in nitric oxide (NO(•)), the latter being a known negative regulator of GLO-I in BRP. In BREC and BRP, candesartan restored GLO-I and reduced NO(•). Similar events occurred in vivo, with the elevated RAS of the diabetic Ren-2 rat, but not the diabetic Sprague-Dawley rat, reducing retinal GLO-I. In diabetic Ren-2 rats, candesartan reduced retinal acellular capillaries, inflammation, and inducible nitric oxide synthase and NO(•), and restored GLO-I. CONCLUSIONS We have identified a novel mechanism by which candesartan improves diabetic retinopathy through the restoration of GLO-I.
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Affiliation(s)
- Antonia G Miller
- Oxidative Stress Laboratory, Diabetes Division, Baker IDI Heart and Diabetes Institute, Melbourne, Australia.
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Tatti P, Di Mauro P, Masselli L, Longobardi A, Barber A. Prevention of diabetic eye disease: the commonest cause of blindness in individuals younger than 65 years. Clin Ophthalmol 2010; 4:1291-8. [PMID: 21139669 PMCID: PMC2993103 DOI: 10.2147/opth.s10273] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
There has been a considerable advancement in the treatment of diabetes and understanding of the biochemical mechanisms underlying diabetic complications in the last 20 years. However, this advancement has not translated into a consistent reduction in diabetic retinopathy, one of the most frightening complications of diabetes mellitus. It is probable that greater attention to preventive intervention will help reduce the damage load in the next future, and that several drugs for the treatment of more advanced stages of diabetic retinopathy will become available. Competent strategies targeting prevention based on screening programs should be proposed to reduce the burden and to improve the clinical outcome of this devastating diabetes complication.
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Fletcher EL, Phipps JA, Ward MM, Vessey KA, Wilkinson-Berka JL. The renin-angiotensin system in retinal health and disease: Its influence on neurons, glia and the vasculature. Prog Retin Eye Res 2010; 29:284-311. [PMID: 20380890 DOI: 10.1016/j.preteyeres.2010.03.003] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Renin-Angiotensin System is classically recognized for its role in the control of systemic blood pressure. However, the retina is recognized to have all the components necessary for angiotensin II formation, suggestive of a role for Angiotensin II in the retina that is independent of the systemic circulation. The most well described effects of Angiotensin II are on the retinal vasculature, with roles in vasoconstriction and angiogenesis. However, it is now emerging that Angiotensin II has roles in modulation of retinal function, possibly in regulating GABAergic amacrine cells. In addition, Angiotensin II is likely to have effects on glia. Angiotensin II has also been implicated in retinal vascular diseases such as Retinopathy of Prematurity and diabetic retinopathty, and more recently actions in choroidal neovascularizaiton and glaucoma have also emerged. The mechanisms by which Angiotensin II promotes angiogensis in retinal vascular diseases is indicative of the complexity of the RAS and the variety of cell types that it effects. Indeed, these diseases are not purely characterized by direct effects of Angiotensin II on the vasculature. In retinopathy of prematurity, for example, blockade of AT1 receptors prevents pathological angiogenesis, but also promotes revascularization of avascular regions of the retina. The primary site of action of Angiotensin II in this disease may be on retinal glia, rather than the vasculature. Indeed, blockade of AT1 receptors prevents glial loss and promotes the re-establishment of normal vessel growth. Blockade of RAS as a treatment for preventing the incidence and progression of diabetic retinopathy has also emerged based on a series of studies in animal models showing that blockade of the RAS prevents the development of a variety of vascular and neuronal deficits in this disease. Importantly these effects may be independent of actions on systemic blood pressure. This has culminated recently with the completion of several large multi-centre clinical trials that showed that blockade of the RAS may be of benefit in some at risk patients with diabetes. With the emergence of novel compounds targeting different aspects of the RAS even more effective ways of blocking the RAS may be possible in the future.
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Affiliation(s)
- Erica L Fletcher
- Department of Anatomy and Cell Biology, The University of Melbourne, Parkville 3010, Victoria, Australia.
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Downie LE, Hatzopoulos KM, Pianta MJ, Vingrys AJ, Wilkinson-Berka JL, Kalloniatis M, Fletcher EL. Angiotensin type-1 receptor inhibition is neuroprotective to amacrine cells in a rat model of retinopathy of prematurity. J Comp Neurol 2010; 518:41-63. [DOI: 10.1002/cne.22205] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Clapp C, Thebault S, Jeziorski MC, Martínez De La Escalera G. Peptide hormone regulation of angiogenesis. Physiol Rev 2009; 89:1177-215. [PMID: 19789380 DOI: 10.1152/physrev.00024.2009] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
It is now apparent that regulation of blood vessel growth contributes to the classical actions of hormones on development, growth, and reproduction. Endothelial cells are ideally positioned to respond to hormones, which act in concert with locally produced chemical mediators to regulate their growth, motility, function, and survival. Hormones affect angiogenesis either directly through actions on endothelial cells or indirectly by regulating proangiogenic factors like vascular endothelial growth factor. Importantly, the local microenvironment of endothelial cells can determine the outcome of hormone action on angiogenesis. Members of the growth hormone/prolactin/placental lactogen, the renin-angiotensin, and the kallikrein-kinin systems that exert stimulatory effects on angiogenesis can acquire antiangiogenic properties after undergoing proteolytic cleavage. In view of the opposing effects of hormonal fragments and precursor molecules, the regulation of the proteases responsible for specific protein cleavage represents an efficient mechanism for balancing angiogenesis. This review presents an overview of the actions on angiogenesis of the above-mentioned peptide hormonal families and addresses how specific proteolysis alters the final outcome of these actions in the context of health and disease.
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Affiliation(s)
- Carmen Clapp
- Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, Mexico.
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Khamseh ME, Safarnejad B, Baradaran HR. The effect of captopril on progression of retinopathy in type 2 diabetes. Diabetes Technol Ther 2009; 11:711-5. [PMID: 19905887 DOI: 10.1089/dia.2009.0073] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND Diabetic retinopathy is the leading cause of blindness in those of working age in the world. However, it is a preventable vision loss. According to current animal studies, it could be hypothesized that using angiotensin-converting enzyme inhibitors could play a crucial role as a protective factor in the progression of retinopathy in human. Because little known is about this effect in humans, we designed a case-control study to explore whether captopril could be a protective factor for prevention of retinopathy in patients with diabetes. METHODS A case-control study was conducted on 164 patients with type 2 diabetes. Thirty-three patients with retinopathy were considered as cases, and 41 patients, without retinopathy, were designated as controls. All biochemical data were collected from results of laboratory tests at the last clinical visit. Dilated eye examination was performed by a trained ophthalmologist using direct and indirect ophthalmoscopy on dilated pupils. RESULTS Retinopathy was determined to be 35.4% and occurred more in men. Older age, male sex, longer duration of diabetes, higher systolic blood pressure, uncontrolled diabetes, and lower body mass index were associated with retinopathy. In our model only age (odds ratio [OR] = 3.2, 95% confidence interval [CI] = 1.3-7.9) and hemoglobin A1c (HbA1c) (OR = 3.6, 95% CI = 1.3-9.9) were found to be associated with the risk of retinopathy. Forty-five percent had hypertension. Age (OR = 2.9, 95% CI = 1.8-4.7), duration of diabetes (OR = 2.4, 95% CI = 1.5-3.87), and HbA1c (OR = 3.73, 95% CI = 1.82-7.64) were associated with developing retinopathy in patients with diabetes and hypertension. However, captopril was shown to be a protective factor after adjusting other variables in our model. This effect was not statistically significant (OR = 1.5, 95% CI = 0.37-6.2). CONCLUSIONS The benefit of using captopril to slow or prevent the progression of retinopathy has been demonstrated in this study. However, statistically it is very difficult to be confident in interpreting the results, and therefore more trials are needed.
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Affiliation(s)
- Mohammad E Khamseh
- Institute of Endocrinology and Metabolism, Iran University of Medical Sciences, Tehran, Iran.
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Steckelings UM, Rompe F, Kaschina E, Unger T. The evolving story of the RAAS in hypertension, diabetes and CV disease - moving from macrovascular to microvascular targets. Fundam Clin Pharmacol 2009; 23:693-703. [DOI: 10.1111/j.1472-8206.2009.00780.x] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Calcutt NA, Cooper ME, Kern TS, Schmidt AM. Therapies for hyperglycaemia-induced diabetic complications: from animal models to clinical trials. Nat Rev Drug Discov 2009; 8:417-29. [PMID: 19404313 PMCID: PMC7097138 DOI: 10.1038/nrd2476] [Citation(s) in RCA: 239] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Diabetic complications — the long-term damage to various organ systems — are a great cause of mortality and morbidity in both type 1 and type 2 diabetes. There are currently few therapeutic options to prevent or ameliorate these complications. High blood glucose levels and the subsequent metabolic consequences of hyperglycaemia are widely considered the primary event that initiates diabetic complications, although there is accumulating evidence that impaired insulin signalling arising from insulin deficiency and insulin resistance may also have a pathogenic role. Vascular dysfunction is a prominent complication of diabetes that is widely held to underlie damage to organ systems such as the macrovasculature, kidneys, eyes and nerves. Other consequences of diabetes, such as dyslipidaemia and hypertension, are key modifiers of vascular injury and act as accelerators of diabetic complications. Numerous pathogenic mechanisms, including increased polyol pathway flux and mitochondrial activity, activation of protein kinase C and NADPH oxidase and signalling through the receptor for advanced glycation end products (RAGE) pathway, seem to form a central pathogenic axis that is common to most, if not all, of the complications of diabetes. These disorders all promote excess production of pro-oxidative molecules. Organ-specific mechanisms, such as diminished growth factor support and repair pathway activation, must also be considered. Few animal models of diabetic complications faithfully reflect the advanced stages of organ pathology seen in humans. Current models can be viewed as potentially illustrating early biochemical and functional disorders of diabetes that ultimately lead to advanced pathology. New animal models are being developed using both a reductionist approach for examining specific gene products of interest and also by combining diverse molecular and physiological risk factors. Control of blood glucose levels and lipids remains the most meaningful approach for preventing diabetic complications. This strategy is likely to be complemented by a diverse range of more focused therapeutics that have emerged from mechanistic studies in animal models and which are currently in clinical development. Some of these, such as those targeting cardiovascular disease, have the potential to affect several diabetic complications, whereas others focus on intervening in organ-specific pathogenic mechanisms. It is probable that combination therapies aimed at the hyperglycaemia-driven pathogenic axis and also at organ-specific disorders will provide the most effective approach to treating the diverse complications of diabetes.
Long-term diabetes increases the likelihood of developing complications such as macrovascular disease, nephropathy, retinopathy and neuropathy. This Review highlights the range of pathologies that are precipitated by hyperglycaemia and discusses recent developments in preclinical and clinical research for each of these complications. Long-term diabetes increases the likelihood of developing secondary damage to numerous systems, and these complications represent a substantial cause of morbidity and mortality. Establishing the causes of diabetes remains the key step towards eradicating the disease, but the prevention and amelioration of diabetic complications is equally important for the millions of individuals who already have the disease or are likely to develop it before prophylaxis or a cure become routinely available. In this Review, we focus on four common complications of diabetes, discuss the range of pathologies that are precipitated by hyperglycaemia and highlight emerging targets for therapeutic intervention.
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Affiliation(s)
- Nigel A Calcutt
- Department of Pathology, University of California, San Diego, La Jolla, California 92093, USA.
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