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Dias PB, Messias-Reason I, Hokazono K, Nisihara R. The role of mannose-binding lectin (MBL) in diabetic retinopathy: A scoping review. Immunol Lett 2024; 267:106863. [PMID: 38705482 DOI: 10.1016/j.imlet.2024.106863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Revised: 04/24/2024] [Accepted: 04/30/2024] [Indexed: 05/07/2024]
Abstract
Diabetes mellitus (DM) is a chronic systemic disease characterized by a multifactorial nature, which may lead to several macro and microvascular complications. Diabetic retinopathy (DR) is one of the most severe microvascular complications of DM, which can result in permanent blindness. The mechanisms involved in the pathogenesis of DR are multiple and still poorly understood. Factors such as dysregulation of vascular regeneration, oxidative and hyperosmolar stress in addition to inflammatory processes have been associated with the pathogenesis of DR. Furthermore, compelling evidence shows that components of the immune system, including the complement system, play a relevant role in the development of the disease. Studies suggest that high concentrations of mannose-binding lectin (MBL), an essential component of the complement lectin pathway, may contribute to the development of DR in patients with DM. This review provides an update on the possible role of the complement system, specifically the lectin pathway, in the pathogenesis of DR and discusses the potential of MBL as a non-invasive biomarker for both, the presence and severity of DR, in addition to its potential as a therapeutic target for intervention strategies.
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Affiliation(s)
- Paula Basso Dias
- Clinical Hospital, Federal University of Paraná, Curitiba, Brazil; Department of Ophthalmology, Clinical Hospital, Federal University of Paraná, Curitiba, Brazil
| | | | - Kenzo Hokazono
- Department of Ophthalmology, Clinical Hospital, Federal University of Paraná, Curitiba, Brazil
| | - Renato Nisihara
- Clinical Hospital, Federal University of Paraná, Curitiba, Brazil; Department of Medicine, Positivo University, Curitiba, Brazil.
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Huang Z, Chu WK, Ng TK, Chen S, Liang J, Chen C, Xu Y, Xie B, Ke S, Liu Q, Chen W, Huang D. Protective effects of nattokinase against microvasculopathy and neuroinflammation in diabetic retinopathy. J Diabetes 2023; 15:866-880. [PMID: 37403338 PMCID: PMC10590680 DOI: 10.1111/1753-0407.13439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 05/25/2023] [Accepted: 06/12/2023] [Indexed: 07/06/2023] Open
Abstract
AIMS Diabetic retinopathy (DR) is a significant global public health concern. Alternative, safe, and cost-effective pharmacologic approaches are warranted. We aimed to investigate the therapeutic potential of nattokinase (NK) for early DR and the underlying molecular mechanism. METHODS A mouse model of diabetes induced by streptozotocin was utilized and NK was administered via intravitreal injection. Microvascular abnormities were evaluated by examining the leakage from blood-retinal barrier dysfunction and loss of pericytes. Retinal neuroinflammation was examined through the assessment of glial activation and leukostasis. The level of high mobility group box 1 (HMGB1) and its downstream signaling molecules was evaluated following NK treatment. RESULTS NK administration significantly improved the blood-retinal barrier function and rescued pericyte loss in the diabetic retinas. Additionally, NK treatment inhibited diabetes-induced gliosis and inflammatory response and protected retinal neurons from diabetes-induced injury. NK also improved high glucose-induced dysfunction in cultured human retinal micrangium endothelial cells. Mechanistically, NK regulated diabetes-induced inflammation partially by modulating HMGB1 signaling in the activated microglia. CONCLUSIONS This study demonstrated the protective effects of NK against microvascular damages and neuroinflammation in the streptozotocin-induced DR model, suggesting that NK could be a potential pharmaceutical agent for the treatment of DR.
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Affiliation(s)
- Zijing Huang
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong KongShantouChina
| | - Wai Kit Chu
- Department of Ophthalmology & Visual SciencesThe Chinese University of Hong KongHong KongChina
| | - Tsz Kin Ng
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong KongShantouChina
- Department of Ophthalmology & Visual SciencesThe Chinese University of Hong KongHong KongChina
- Shantou University Medical CollegeShantouChina
| | - Shaolang Chen
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong KongShantouChina
| | - Jiajian Liang
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong KongShantouChina
| | - Chong‐Bo Chen
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong KongShantouChina
| | - Yanxuan Xu
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong KongShantouChina
| | - Biyao Xie
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong KongShantouChina
- Shantou University Medical CollegeShantouChina
| | - Shuping Ke
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong KongShantouChina
- Shantou University Medical CollegeShantouChina
| | - Qingping Liu
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong KongShantouChina
| | - Weiqi Chen
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong KongShantouChina
| | - Dingguo Huang
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong KongShantouChina
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Violetta L, Kartasasmita AS, Supriyadi R, Rita C. Circulating Biomarkers to Predict Diabetic Retinopathy in Patients with Diabetic Kidney Disease. Vision (Basel) 2023; 7:vision7020034. [PMID: 37092467 PMCID: PMC10123608 DOI: 10.3390/vision7020034] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 02/05/2023] [Accepted: 03/30/2023] [Indexed: 04/25/2023] Open
Abstract
The purpose of this review is to outline the currently available circulating biomarkers to predict diabetic retinopathy (DR) in patients with diabetic kidney disease (DKD). Studies have extensively reported the association between DR and DKD, suggesting the presence of common pathways of microangiopathy. The presence of other ocular complications including diabetic cataracts may hinder the detection of retinopathy, which may affect the visual outcome after surgery. Unlike DKD screening, the detection of DR requires complex, costly machines and trained technicians. Recognizing potential biological markers related to glycation and oxidative stress, inflammation and endothelial dysfunction, basement membrane thickening, angiogenesis, and thrombosis as well as novel molecular markers involved in the microangiopathy process may be useful as predictors of retinopathy and identify those at risk of DR progression, especially in cases where retinal visualization becomes a clinical challenge. Further investigations could assist in deciding which biomarkers possess the highest predictive power to predict retinopathy in clinical settings.
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Affiliation(s)
- Laurencia Violetta
- Nephrology Division, Department of Internal Medicine, Gatot Soebroto Indonesia Army Central Hospital, Jakarta 10410, Indonesia
| | | | - Rudi Supriyadi
- Faculty of Medicine, Universitas Padjajaran, Bandung 40132, Indonesia
| | - Coriejati Rita
- Faculty of Medicine, Universitas Padjajaran, Bandung 40132, Indonesia
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Fletcher EL, Dixon MA, Mills SA, Jobling AI. Anomalies in neurovascular coupling during early diabetes: A review. Clin Exp Ophthalmol 2023; 51:81-91. [PMID: 36349522 PMCID: PMC10947109 DOI: 10.1111/ceo.14190] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Revised: 10/26/2022] [Accepted: 11/04/2022] [Indexed: 11/11/2022]
Abstract
Diabetic retinopathy is the most feared complication for those with diabetes. Although visible vascular pathology traditionally defines the management of this condition, it is now recognised that a range of cellular changes occur in the retina from an early stage of diabetes. One of the most significant functional changes that occurs in those with diabetes is a loss of vasoregulation in response to changes in neural activity. There are several retinal cell types that are critical for mediating so-called neurovascular coupling, including Müller cells, microglia and pericytes. Although there is a great deal of evidence that suggests that Müller cells are integral to regulating the vasculature, they only modulate part of the vascular tree, highlighting the complexity of vasoregulation within the retina. Recent studies suggest that retinal immune cells, microglia, play an important role in mediating vasoconstriction. Importantly, retinal microglia contact both the vasculature and neural synapses and induce vasoconstriction in response to neurally expressed chemokines such as fractalkine. This microglial-dependent regulation occurs via the vasomediator angiotensinogen. Diabetes alters the way microglia regulate the retinal vasculature, by increasing angiotensinogen expression, causing capillary vasoconstriction and contributing to a loss of vascular reactivity to physiological signals. This article summarises recent studies showing changes in vascular regulation during diabetes, the potential mechanisms by which this occurs and the significance of these early changes to the progression of diabetic retinopathy.
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Affiliation(s)
- Erica L. Fletcher
- Department of Anatomy and PhysiologyThe University of MelbourneMelbourneVictoriaAustralia
| | - Michael A. Dixon
- Department of Anatomy and PhysiologyThe University of MelbourneMelbourneVictoriaAustralia
| | - Samuel A. Mills
- Department of Anatomy and Developmental BiologyMonash UniversityMelbourneVictoriaAustralia
| | - Andrew I. Jobling
- Department of Anatomy and PhysiologyThe University of MelbourneMelbourneVictoriaAustralia
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Rola autoimmunizacji w rozwoju powikłań cukrzycowych – przegląd badań. POSTEP HIG MED DOSW 2021. [DOI: 10.2478/ahem-2021-0043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Abstrakt
Przewlekłe powikłania cukrzycy są główną przyczyną obniżenia jakości życia, niepełnosprawności, a nawet przedwczesnej śmierci pacjentów cierpiących na tę chorobę. Mimo istotnego postępu w dziedzinie farmakoterapii, ich leczenie pozostaje nadal wyzwaniem w codziennej praktyce klinicznej. Brak terapii przyczynowej wynika z niewystarczającego zrozumienia molekularnych mechanizmów uszkadzających poszczególne narządy w cukrzycy. Uważa się, że etiopatogeneza tych powikłań jest złożona i zależy od czynników genetycznych i środowiskowych. W ich rozwoju, oprócz zaburzeń metabolicznych związanych z hiperglikemią, nasilenia stresu oksydacyjnego, dysfunkcji śródbłonka, indukcji stanu zapalnego, coraz częściej wskazuje się też na znaczącą rolę zaburzeń immunologicznych.
Wyniki badań doświadczalnych przeprowadzonych na zwierzętach, jak również na hodowlach tkankowych, oraz obserwacje kliniczne potwierdzają udział układu odpornościowego obejmujący aktywność autoreaktywnych limfocytów oraz cytotoksyczne działanie autoprzeciwciał w rozwoju poszczególnych powikłań w obu typach cukrzycy. Wydaje się zatem, że zachwianie równowagi immunologicznej wyzwalające autoagresję jest ważnym czynnikiem przyczyniającym się do dysfunkcji poszczególnych organów w typach cukrzycy 1 i 2.
Dokładne zrozumienie immunopatogenezy tych zaburzeń może zmienić dotychczasowe podejście w leczeniu powikłań cukrzycy oraz umożliwić opracowanie skutecznej terapii przyczynowej ukierunkowanej na układ odpornościowy. Identyfikacja swoistych autoprzeciwciał mogłaby usprawnić ich wczesną diagnostykę i prewencję. W artykule podjęto próbę analizy czynników ryzyka najczęstszych schorzeń o podłożu autoimmunizacyjnym, ich związku z typem 1 i 2 cukrzycy oraz podsumowano potencjalne znaczenie autoagresji w rozwoju jej powikłań w oparciu o wyniki dotychczasowych badań doświadczalnych i klinicznych.
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Miyagawa T, Taniguchi T, Saigusa R, Fukayama M, Takahashi T, Yamashita T, Hirabayashi M, Miura S, Nakamura K, Yoshizaki A, Sato S, Asano Y. Fli1 deficiency induces endothelial adipsin expression, contributing to the onset of pulmonary arterial hypertension in systemic sclerosis. Rheumatology (Oxford) 2021; 59:2005-2015. [PMID: 31782787 DOI: 10.1093/rheumatology/kez517] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 10/03/2019] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVES Adipsin, or complement factor D, is a serine proteinase catalysing complement factor C3 breakdown, leading to the production of opsonin (C3b), membrane attack complex (C5b-C9) and anaphylatoxins (C3a and C5a). Since adipsin is potentially associated with pulmonary arterial hypertension in SSc, we investigated adipsin expression in dermal small vessels of SSc-involved skin, the mechanism regulating adipsin expression in endothelial cells, and the correlation of serum adipsin levels with SSc clinical symptoms. METHODS Adipsin expression was assessed by immunohistochemistry with skin sections of SSc and healthy subjects. mRNA levels of target genes and transcription factor binding to the ADIPSIN promoter were evaluated by quantitative reverse transcription PCR and chromatin immunoprecipitation, respectively. Serum adipsin levels were determined by enzyme-linked immunosorbent assay. RESULTS Adipsin expression was remarkably increased in dermal small vessels of SSc-involved skin as compared with those of healthy control skin. Consistent with the notion that Fli1 deficiency induces SSc-like phenotypes in various types of cells, FLI1 siRNA enhanced adipsin expression at protein and mRNA levels and Fli1 bound to the ADIPSIN promoter in human dermal microvascular endothelial cells. Serum adipsin levels were significantly lower in diffuse cutaneous SSc patients than in limited cutaneous SSc patients and healthy controls, and were associated positively with elevated right ventricular systolic pressure and inversely with interstitial lung disease by multivariate regression analysis. CONCLUSION Adipsin is up-regulated at least partially by Fli1 deficiency in endothelial cells, potentially contributing to the development of pulmonary vascular involvement in SSc.
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Affiliation(s)
- Takuya Miyagawa
- Department of Dermatology, University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Takashi Taniguchi
- Department of Dermatology, University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Ryosuke Saigusa
- Department of Dermatology, University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Maiko Fukayama
- Department of Dermatology, University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Takehiro Takahashi
- Department of Dermatology, University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Takashi Yamashita
- Department of Dermatology, University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Megumi Hirabayashi
- Department of Dermatology, University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Shunsuke Miura
- Department of Dermatology, University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Kouki Nakamura
- Department of Dermatology, University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Ayumi Yoshizaki
- Department of Dermatology, University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Shinichi Sato
- Department of Dermatology, University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Yoshihide Asano
- Department of Dermatology, University of Tokyo Graduate School of Medicine, Tokyo, Japan
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7
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The innate immune system in diabetic retinopathy. Prog Retin Eye Res 2021; 84:100940. [PMID: 33429059 DOI: 10.1016/j.preteyeres.2021.100940] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 12/24/2020] [Accepted: 01/03/2021] [Indexed: 12/20/2022]
Abstract
The prevalence of diabetes has been rising steadily in the past half-century, along with the burden of its associated complications, including diabetic retinopathy (DR). DR is currently the most common cause of vision loss in working-age adults in the United States. Historically, DR has been diagnosed and classified clinically based on what is visible by fundoscopy; that is vasculature alterations. However, recent technological advances have confirmed pathology of the neuroretina prior to any detectable vascular changes. These, coupled with molecular studies, and the positive impact of anti-inflammatory therapeutics in DR patients have highlighted the central involvement of the innate immune system. Reminiscent of the systemic impact of diabetes, immune dysregulation has become increasingly identified as a key element of the pathophysiology of DR by interfering with normal homeostatic systems. This review uses the growing body of literature across various model systems to demonstrate the clear involvement of all three pillars of the immune system: immune-competent cells, mediators, and the complement system. It also demonstrates how the relative contribution of each of these requires more extensive analysis, including in human tissues over the continuum of disease progression. Finally, although this review demonstrates how the complex interactions of the immune system pose many more questions than answers, the intimately connected nature of the three pillars of the immune system may also point to possible new targets to reverse or even halt reverse retinopathy.
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Obasanmi G, Lois N, Armstrong D, Lavery NJ, Hombrebueno JR, Lynch A, Wright DM, Chen M, Xu H. Circulating Leukocyte Alterations and the Development/Progression of Diabetic Retinopathy in Type 1 Diabetic Patients - A Pilot Study. Curr Eye Res 2020; 45:1144-1154. [PMID: 31997663 DOI: 10.1080/02713683.2020.1718165] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND/AIMS The aim of this study was to investigate the relationship between alterations in circulating leukocytes and the initiation and progression of DR in people with type 1 diabetes (T1D). METHODS Forty-one patients with T1D [13 mild non-proliferative DR (mNPDR), 14 active proliferative DR (aPDR) and 14 inactive PDR (iPDR)], and 13 age- and gender-matched healthy controls were recruited prospectively. Circulating leukocytes, including CD4+ and CD8+ T-cells, CD14+CD16-, CD14-CD16+ and CD14+CD16+ monocytes; CD16+HLA-DR- neutrophils, CD19+ B-cells and CD56+ natural killer cells and their cell surface adhesion molecules and chemokine receptors (HLA-DR, CD62L, CCR2, CCR5, CD66a, CD157 and CD305) were examined by flow cytometry. RESULTS In DR patients, compared to healthy controls, increased proportions of neutrophils (p = .0152); reduced proportions of lymphocytes (p = .0002), HLA-DR+ leukocytes (p = .0406) and non-classical monocytes (p = .0204); and reduced expression of CD66a (p = .0048) and CD157 (p = .0007) on CD4+ T cells were observed. Compared to healthy controls, CD19+ B cells were reduced at the mNPDR but not aPDR patients. Total lymphocytes, CD4+ T cells and CD8+ T cells progressively decreased whereas neutrophils, the neutrophil/lymphocyte ratio and the neutrophil/CD4+ ratio progressively increased from early to late stages of DR, reaching statistical significance at the aPDR stage. Longer diabetes duration was associated with a reduced proportion of CD8+ T cells (p = .002) and increased neutrophil/CD8+ ratio (p = .033). CONCLUSIONS In this pilot study, DR is associated with increased innate cellular immunity especially neutrophils and reduced adaptive cellular immunity particularly lymphocytes. Impaired B-cell immunity may play a role in the initiation of DR; whereas impaired T-cell immunity with increased neutrophil response may contribute to progression of DR from non-proliferative to proliferative stages in T1D patients. Large multicenter studies are needed to further understand the immune dysregulation in DR initiation and progression.
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Affiliation(s)
- Gideon Obasanmi
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast , Belfast, UK
| | - Noemi Lois
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast , Belfast, UK
| | - David Armstrong
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast , Belfast, UK
| | - Nuala-Jane Lavery
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast , Belfast, UK
| | - Jose Romero Hombrebueno
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast , Belfast, UK
| | - Aisling Lynch
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast , Belfast, UK
| | - David M Wright
- Centre for Public Health, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast , Belfast, UK
| | - Mei Chen
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast , Belfast, UK
| | - Heping Xu
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast , Belfast, UK
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Kang TY, Bocci F, Jolly MK, Levine H, Onuchic JN, Levchenko A. Pericytes enable effective angiogenesis in the presence of proinflammatory signals. Proc Natl Acad Sci U S A 2019; 116:23551-23561. [PMID: 31685607 PMCID: PMC6876202 DOI: 10.1073/pnas.1913373116] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Angiogenesis frequently occurs in the context of acute or persistent inflammation. The complex interplay of proinflammatory and proangiogenic cues is only partially understood. Using an experimental model, permitting exposure of developing blood vessel sprouts to multiple combinations of diverse biochemical stimuli and juxtacrine cell interactions, we present evidence that a proinflammatory cytokine, tumor necrosis factor (TNF), can have both proangiogenic and antiangiogenic effects, depending on the dose and the presence of pericytes. In particular, we find that pericytes can rescue and enhance angiogenesis in the presence of otherwise-inhibitory high TNF doses. This sharp switch from proangiogenic to antiangiogenic effect of TNF observed with an escalating dose of this cytokine, as well as the effect of pericytes, are explained by a mathematical model trained on the biochemical data. Furthermore, this model was predictive of the effects of diverse combinations of proinflammatory and antiinflammatory cues, and variable pericyte coverage. The mechanism supports the effect of TNF and pericytes as modulating signaling networks impinging on Notch signaling and specification of the Tip and Stalk phenotypes. This integrative analysis elucidates the plasticity of the angiogenic morphogenesis in the presence of diverse and potentially conflicting cues, with immediate implications for many physiological and pathological settings.
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Affiliation(s)
- Tae-Yun Kang
- Department of Biomedical Engineering, Yale University, New Haven, CT 06520
- Yale Systems Biology Institute, Yale University, New Haven, CT 06520
| | - Federico Bocci
- Center for Theoretical Biological Physics, Rice University, Houston, TX 77005
- Department of Chemistry, Rice University, Houston, TX 77005
| | - Mohit Kumar Jolly
- Centre for BioSystems Science and Engineering, Indian Institute of Science, Bangalore 560012, India
| | - Herbert Levine
- Department of Physics, Northeastern University, Boston, MA 02115;
| | - José Nelson Onuchic
- Center for Theoretical Biological Physics, Rice University, Houston, TX 77005;
- Department of Chemistry, Rice University, Houston, TX 77005
- Department of Physics and Astronomy, Rice University, Houston, TX 77005
- Department of Biosciences, Rice University, Houston, TX 77005
| | - Andre Levchenko
- Department of Biomedical Engineering, Yale University, New Haven, CT 06520;
- Yale Systems Biology Institute, Yale University, New Haven, CT 06520
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Spencer BG, Estevez JJ, Liu E, Craig JE, Finnie JW. Pericytes, inflammation, and diabetic retinopathy. Inflammopharmacology 2019; 28:697-709. [PMID: 31612299 DOI: 10.1007/s10787-019-00647-9] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 09/13/2019] [Indexed: 12/11/2022]
Abstract
Diabetic retinopathy (DR) is a frequent complication of diabetes mellitus, and a common cause of vision impairment and blindness in these patients, yet many aspects of its pathogenesis remain unresolved. Furthermore, current treatments are not effective in all patients, are only indicated in advanced disease, and are associated with significant adverse effects. This review describes the microvascular features of DR, and how pericyte depletion and low-grade chronic inflammation contribute to the pathogenesis of this common ophthalmic disorder. Existing, novel and investigational pharmacological strategies aimed at modulating the inflammatory component of DR and ameliorating pericyte loss to potentially improve clinical outcomes for patients with diabetic retinopathy, are discussed.
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Affiliation(s)
- Benjamin G Spencer
- TMOU, Flinders Medical Centre, Southern Adelaide Local Health Network, SA Health, Flinders Drive, Bedford Park, SA, 5042, Australia.
| | - Jose J Estevez
- Flinders Centre for Ophthalmology, Eye and Vision Research, Department of Ophthalmology, Flinders University, Adelaide, Australia
| | - Ebony Liu
- Flinders Centre for Ophthalmology, Eye and Vision Research, Department of Ophthalmology, Flinders University, Adelaide, Australia
| | - Jamie E Craig
- Flinders Centre for Ophthalmology, Eye and Vision Research, Department of Ophthalmology, Flinders University, Adelaide, Australia
| | - John W Finnie
- Discipline of Anatomy and Pathology, Adelaide Medical School, University of Adelaide, Adelaide, SA, Australia
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11
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Role of complement in diabetes. Mol Immunol 2019; 114:270-277. [PMID: 31400630 DOI: 10.1016/j.molimm.2019.07.031] [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: 05/10/2019] [Revised: 07/29/2019] [Accepted: 07/30/2019] [Indexed: 02/07/2023]
Abstract
Accumulating evidence suggests a role for the complement system in the pathogenesis of diabetes and the vascular complications that characterise this condition. Complement proteins contribute to the development of type 1 diabetes (T1D) by enhancing the underlying organ-specific autoimmune processes. Complement upregulation and activation is also an important feature of insulin resistance and the development of type 2 diabetes (T2D). Moreover, animal and human studies indicate that complement proteins are involved in the pathogenic mechanisms leading to diabetic microvascular and macrovascular complications. The adverse vascular effects of complement appear to be related to enhancement of the inflammatory process and the predisposition to a thrombotic environment, eventually leading to vascular occlusion. Complement proteins have been considered as therapeutic targets to prevent or treat vascular disease but studies have been mainly conducted in animal models, while human work has been both limited and inconclusive so far. Further studies are needed to understand the potential role of complement proteins as therapeutic targets for reversal of the pathological processes leading to T1D and T2D and for the prevention/treatment of diabetic vascular complications.
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Akhtar-Schäfer I, Wang L, Krohne TU, Xu H, Langmann T. Modulation of three key innate immune pathways for the most common retinal degenerative diseases. EMBO Mol Med 2019; 10:emmm.201708259. [PMID: 30224384 PMCID: PMC6180304 DOI: 10.15252/emmm.201708259] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
This review highlights the role of three key immune pathways in the pathophysiology of major retinal degenerative diseases including diabetic retinopathy, age‐related macular degeneration, and rare retinal dystrophies. We first discuss the mechanisms how loss of retinal homeostasis evokes an unbalanced retinal immune reaction involving responses of local microglia and recruited macrophages, activity of the alternative complement system, and inflammasome assembly in the retinal pigment epithelium. Presenting these key mechanisms as complementary targets, we specifically emphasize the concept of immunomodulation as potential treatment strategy to prevent or delay vision loss. Promising molecules are ligands for phagocyte receptors, specific inhibitors of complement activation products, and inflammasome inhibitors. We comprehensively summarize the scientific evidence for this strategy from preclinical animal models, human ocular tissue analyses, and clinical trials evolving in the last few years.
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Affiliation(s)
- Isha Akhtar-Schäfer
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, University of Cologne, Cologne, Germany
| | - Luping Wang
- Department of Ophthalmology, University of Bonn, Bonn, Germany
| | - Tim U Krohne
- Department of Ophthalmology, University of Bonn, Bonn, Germany
| | - Heping Xu
- Centre for Experimental Medicine, The Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry & Biomedical Sciences, Queen's University Belfast, Belfast, UK
| | - Thomas Langmann
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, University of Cologne, Cologne, Germany .,Center for Molecular Medicine, University of Cologne, Cologne, Germany
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13
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Wang X, Wu M, Cao Y, Zhang Z, Guo F, Li X, Zhang Y. Exploring the role of programmed cell death protein 1 and its ligand 1 in eye diseases. Crit Rev Clin Lab Sci 2019; 56:18-32. [PMID: 30602320 DOI: 10.1080/10408363.2018.1522292] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Programmed death receptor-1 (PD-1) and its ligand, PD-L1, as negative co-stimulatory molecules, are indispensable for regulating both physiological and pathological immune responses. The PD-1/PD-L1-mediated signaling pathway has been studied extensively in cancer research and has become a hotspot for biopharmaceuticals and immunotherapy. Furthermore, monoclonal antibodies to PD-1 have just been approved by the US Food and Drug Administration to treat certain types of malignancies. Recent research has unveiled a close association between the PD-1/PD-L1 system and eye diseases. This review describes the expression and physiological functions of PD-1 and its ligand in ocular tissues and summarizes the pathogenic, regulatory, and therapeutic roles of PD-1/PD-L1 system in eye diseases, including uveal melanoma, autoimmune uveitis, autoimmune dry eye, sympathetic ophthalmia, Graves' ophthalmopathy, diabetic retinopathy, herpes simplex keratitis, and trachoma, with the intent of highlighting the potential of PD-1/PD-L1 as novel therapeutic targets or biomarkers for these ocular diseases.
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Affiliation(s)
- Xiu Wang
- a Tianjin Medical University Eye Hospital , Tianjin Medical University Eye Institute, School of Optometry and Ophthalmology, Tianjin Medical University , Tianjin , China
| | - Mianmian Wu
- a Tianjin Medical University Eye Hospital , Tianjin Medical University Eye Institute, School of Optometry and Ophthalmology, Tianjin Medical University , Tianjin , China
| | - Yunshan Cao
- b Department of Cardiology , Gansu Provincial Hospital , Lanzhou , China.,c Department of Heart Failure, Shanghai East Hospital , Tongji University School of Medicine , Shanghai , China.,d Research Center for Translational Medicine, Shanghai East Hospital , Tongji University School of Medicine , Shanghai , China
| | - Zhi Zhang
- a Tianjin Medical University Eye Hospital , Tianjin Medical University Eye Institute, School of Optometry and Ophthalmology, Tianjin Medical University , Tianjin , China
| | - Fang Guo
- a Tianjin Medical University Eye Hospital , Tianjin Medical University Eye Institute, School of Optometry and Ophthalmology, Tianjin Medical University , Tianjin , China
| | - Xiaorong Li
- a Tianjin Medical University Eye Hospital , Tianjin Medical University Eye Institute, School of Optometry and Ophthalmology, Tianjin Medical University , Tianjin , China
| | - Yan Zhang
- a Tianjin Medical University Eye Hospital , Tianjin Medical University Eye Institute, School of Optometry and Ophthalmology, Tianjin Medical University , Tianjin , China
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14
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Chrzanowska M, Modrzejewska A, Modrzejewska M. New insight into the role of the complement in the most common types of retinopathy-current literature review. Int J Ophthalmol 2018; 11:1856-1864. [PMID: 30450319 DOI: 10.18240/ijo.2018.11.19] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2017] [Accepted: 07/25/2018] [Indexed: 11/23/2022] Open
Abstract
Pathological neovascularisation, which is a critical component of diseases such as age-related macular degeneration (AMD), diabetic retinopathy (DR) and retinopathy of prematurity (ROP), is a frequent cause of compromised vision or blindness. Researchers continuously investigate the role of the complement system in the pathogenesis of retinopathy. Studies have confirmed the role of factors H and I in the development of AMD, and factors H and B in the development of DR. Other components, such as C2, C3, and C5, have also been considered. However, findings on the involvement of the complement system in the pathogenesis of ROP are still inconclusive. This paper presents a review of the current literature data, pointing to the novel results and achievements from research into the role of complement components in the development of retinopathy. There is still a need to continue research in new directions, and to gather more detailed information about this problem which will be useful in the treatment of these diseases.
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Affiliation(s)
- Martyna Chrzanowska
- Department of Ophthalmology, Pomeranian Medical University, Szczecin 70-111, Poland
| | - Anna Modrzejewska
- Department of Ophthalmology, Pomeranian Medical University, Szczecin 70-111, Poland
| | - Monika Modrzejewska
- Department of Ophthalmology, Pomeranian Medical University, Szczecin 70-111, Poland
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15
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Huang C, Fisher KP, Hammer SS, Navitskaya S, Blanchard GJ, Busik JV. Plasma Exosomes Contribute to Microvascular Damage in Diabetic Retinopathy by Activating the Classical Complement Pathway. Diabetes 2018; 67:1639-1649. [PMID: 29866771 PMCID: PMC6054433 DOI: 10.2337/db17-1587] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Accepted: 05/05/2018] [Indexed: 12/12/2022]
Abstract
Diabetic retinopathy (DR) is a microvascular complication of diabetes and is the leading cause of vision loss in working-age adults. Recent studies have implicated the complement system as a player in the development of vascular damage and progression of DR. However, the role and activation of the complement system in DR are not well understood. Exosomes, small vesicles that are secreted into the extracellular environment, have a cargo of complement proteins in plasma, suggesting that they can participate in causing the vascular damage associated with DR. We demonstrate that IgG-laden exosomes in plasma activate the classical complement pathway and that the quantity of these exosomes is increased in diabetes. Moreover, we show that a lack of IgG in exosomes in diabetic mice results in a reduction in retinal vascular damage. The results of this study demonstrate that complement activation by IgG-laden plasma exosomes could contribute to the development of DR.
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Affiliation(s)
- Chao Huang
- Department of Physiology, Michigan State University, East Lansing, MI
| | - Kiera P Fisher
- Department of Physiology, Michigan State University, East Lansing, MI
| | - Sandra S Hammer
- Department of Physiology, Michigan State University, East Lansing, MI
| | | | - Gary J Blanchard
- Department of Chemistry, Michigan State University, East Lansing, MI
| | - Julia V Busik
- Department of Physiology, Michigan State University, East Lansing, MI
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16
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Li Y, Clow F, Fraser JD, Lin F. Therapeutic potential of staphylococcal superantigen-like protein 7 for complement-mediated hemolysis. J Mol Med (Berl) 2018; 96:965-974. [PMID: 30066197 DOI: 10.1007/s00109-018-1678-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 07/23/2018] [Accepted: 07/24/2018] [Indexed: 12/29/2022]
Abstract
Previous studies have demonstrated that staphylococcal superantigen-like protein 7 (SSL7), a protein produced by Staphylococcus aureus, potently inhibits the formation of the complement membrane attack complex by binding to complement component 5 (C5). However, because of the predicted immunogenicity of SSL7 as a foreign protein in humans, its potential as a new complement inhibitor for treating complement-mediated diseases is uncertain. In this study, we found that administration of SSL7 significantly prevented complement-mediated hemolysis and reduced hemoglobinuria in a mouse model of complement-mediated intravascular hemolysis. Interestingly, although repetitive administrations of SSL7 elicited anti-SSL7 antibody production, administration of SSL7 at a dose of 2 μg/mouse was still able to significantly attenuate complement-mediated intravascular hemolysis in vivo in the presence of the antibodies. In addition, even though anti-SSL7 antibodies were detectable in normal human donors, these antibodies did not significantly reduce the complement inhibitory activity of SSL7 in in vitro assays. Finally, inoculation of SSL7 in the anterior chamber of the eye suppressed the production of SSL7-reactive antibodies after repetitive SSL7 administration. These results suggest that SSL7 could be developed as an economical alternative to the existing C5-targeted drug, eculizumab, especially for controlling acute complement activation in catastrophic conditions such as drug-induced immune hemolytic anemia and ABO-incompatible erythrocyte transfusions. These data also suggest that approaches such as anterior chamber-associated immune deviation could be employed to establish an antigen-specific immune tolerance for long-term SSL7 administration. KEY MESSAGES • SSL7 functions in the presence of anti-SSL7 antibodies both in vitro and in vivo. • SSL7 has the potential to be developed as a new and economical complement inhibitor for treating complement-mediated hemolysis.
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Affiliation(s)
- Yan Li
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Fiona Clow
- Department of Molecular Medicine and Pathology, University of Auckland, Auckland, New Zealand
| | - John D Fraser
- Department of Molecular Medicine and Pathology, University of Auckland, Auckland, New Zealand
| | - Feng Lin
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA.
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17
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Natoli R, Fernando N, Dahlenburg T, Jiao H, Aggio-Bruce R, Barnett NL, Chao de la Barca JM, Tcherkez G, Reynier P, Fang J, Chu-Tan JA, Valter K, Provis J, Rutar M. Obesity-induced metabolic disturbance drives oxidative stress and complement activation in the retinal environment. Mol Vis 2018; 24:201-217. [PMID: 29527116 PMCID: PMC5842320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 03/05/2018] [Indexed: 11/03/2022] Open
Abstract
Purpose Systemic increases in reactive oxygen species, and their association with inflammation, have been proposed as an underlying mechanism linking obesity and age-related macular degeneration (AMD). Studies have found increased levels of oxidative stress biomarkers and inflammatory cytokines in obese individuals; however, the correlation between obesity and retinal inflammation has yet to be assessed. We used the leptin-deficient (ob/ob) mouse to further our understanding of the contribution of obesity to retinal oxidative stress and inflammation. Methods Retinas from ob/ob mice were compared to age-matched wild-type controls for retinal function (electroretinography) and gene expression analysis of retinal stress (Gfap), oxidative stress (Gpx3 and Hmox1), and complement activation (C3, C2, Cfb, and Cfh). Oxidative stress was further quantified using a reactive oxygen species and reactive nitrogen species (ROS and RNS) assay. Retinal microglia and macrophage migration to the outer retina and complement activation were determined using immunohistochemistry for IBA1 and C3, respectively. Retinas and sera were used for metabolomic analysis using QTRAP mass spectrometry. Results Retinal function was reduced in ob/ob mice, which correlated to changes in markers of retinal stress, oxidative stress, and inflammation. An increase in C3-expressing microglia and macrophages was detected in the outer retinas of the ob/ob mice, while gene expression studies showed increases in the complement activators (C2 and Cfb) and a decrease in a complement regulator (Cfh). The expression of several metabolites were altered in the ob/ob mice compared to the controls, with changes in polyunsaturated fatty acids (PUFAs) and branched-chain amino acids (BCAAs) detected. Conclusions The results of this study indicate that oxidative stress, inflammation, complement activation, and lipid metabolites in the retinal environment are linked with obesity in ob/ob animals. Understanding the interplay between these components in the retina in obesity will help inform risk factor analysis for acquired retinal degenerations, including AMD.
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Affiliation(s)
- Riccardo Natoli
- The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
- ANU Medical School, The Australian National University, Canberra, Australia
| | - Nilisha Fernando
- The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
| | - Tess Dahlenburg
- The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
| | - Haihan Jiao
- The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
| | - Riemke Aggio-Bruce
- The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
| | - Nigel L. Barnett
- Queensland Eye Institute, South Brisbane, Queensland, Australia
- The University of Queensland, UQ Centre for Clinical Research, Herston, Queensland, Australia
- School of Biomedical Sciences, Queensland University of Technology, Brisbane, Queensland, Australia
| | | | - Guillaume Tcherkez
- Research School of Biology, The Australian National University, Canberra, Australia
| | - Pascal Reynier
- PREMMi / Pôle de Recherche et d’Enseignement en Médecine Mitochondriale, Institut MITOVASC, CNRS 6214, INSERM U1083, Université d'Angers, 49933 Angers, France
- Département de Biochimie et Génétique, Centre Hospitalier Universitaire, 49933 Angers, France
| | - Johnny Fang
- ANU Medical School, The Australian National University, Canberra, Australia
| | - Joshua A. Chu-Tan
- The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
| | - Krisztina Valter
- The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
- ANU Medical School, The Australian National University, Canberra, Australia
| | - Jan Provis
- The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
- ANU Medical School, The Australian National University, Canberra, Australia
| | - Matt Rutar
- The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
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18
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Zhang Y, Chen F, Wang L. Metformin inhibits development of diabetic retinopathy through microRNA-497a-5p. Am J Transl Res 2017; 9:5558-5566. [PMID: 29312507 PMCID: PMC5752905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 11/26/2016] [Indexed: 06/07/2023]
Abstract
Metformin is an AMP-activated protein kinase activator that is widely prescribed for treating type 2 diabetes. Recently, metformin was reported to slow down the development and alleviate the severity of diabetic retinopathy (DR). However, the underlying mechanisms remain unclear. Here, we used an alloxan-induced diabetes mouse model to study the effects of metformin on the development of DR as well as the mechanisms. We found that DR was induced in alloxan-treated mice 10 weeks after alloxan treatment, and treatment of metformin did not prevent the occurrence of alloxan-induced diabetes. However, metformin significantly alleviated the severity of DR, seemingly through attenuating the retina neovascularization. Moreover, the total vascular endothelial cell growth factor A (VEGF-A) mRNA in mouse eyes was not altered by metformin, but the protein levels was decreased. Further analysis showed that metformin may inhibit the VEGF-A protein translation through inducing a VEGF-A-targeting microRNA, microRNA-497a-5p, resulting in reduced retina neovascularization. Thus, our study suggests a previously unappreciated role of metformin in the prevention of development of DR.
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Affiliation(s)
- Yi Zhang
- Department of Ophthalmology, The First Hospital of Jinzhou Medical UniversityJinzhou 121000, China
| | - Fei Chen
- Department of Ultrasonics, The First Hospital of Jinzhou Medical UniversityJinzhou 121000, China
| | - Liang Wang
- Department of Hepatobiliary Surgery, The First Hospital of Jinzhou Medical UniversityJinzhou 121000, China
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19
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Diabetic retinopathy and dysregulated innate immunity. Vision Res 2017; 139:39-46. [PMID: 28571700 DOI: 10.1016/j.visres.2017.04.013] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 04/12/2017] [Accepted: 04/13/2017] [Indexed: 02/07/2023]
Abstract
Diabetic retinopathy (DR) is the progressive degeneration of retinal blood vessels and neurons. Inflammation is known to play an important role in the pathogenesis of DR. During diabetes, metabolic disorder leads to the release of damage-associated molecular patterns (DAMPs) both in the retina and elsewhere in the body. The innate immune system provides the first line of defense against the DAMPs. In the early stages of DR when the blood retinal barrier (BRB) is intact, retinal microglia and the complement system are activated at low levels. This low-level of inflammation (para-inflammation) is believed to be essential to maintain homeostasis and restore functionality. However, prolonged stimulation by DAMPs in the diabetic eye leads to maladaptation of the innate immune system and dysregulated para-inflammation may contribute to DR development. In the advanced stages of DR where immune privilege is comprised, circulating immune cells and serum proteins may infiltrate the retina and participate in retinal chronic inflammation and retinal vascular and neuronal damage. This review discusses how the innate immune system is activated in diabetes and DR. The view also discusses why the protective immune response becomes detrimental in DR.
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20
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Warmke N, Griffin KJ, Cubbon RM. Pericytes in diabetes-associated vascular disease. J Diabetes Complications 2016; 30:1643-1650. [PMID: 27592245 DOI: 10.1016/j.jdiacomp.2016.08.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 08/01/2016] [Accepted: 08/08/2016] [Indexed: 12/21/2022]
Abstract
Pericytes are mural cells that support and stabilise the microvasculature, and are present in all vascular beds. Pericyte-endothelial cell crosstalk is essential in both remodelling and quiescent vasculature, and this complex interaction is often disrupted in disease states. Pericyte loss is believed to be an early hallmark of diabetes-associated microvascular disease, including retinopathy and nephropathy. Here we review the current literature defining pericyte biology in the context of diabetes-associated vascular disease, with a particular focus on whether pericytes contribute actively to disease progression. We also speculate regarding the role of pericytes in the recovery from macrovascular complications, such as critical limb ischaemia. It becomes clear that dysfunctional pericytes are likely to actively induce disease progression by causing vasoconstriction and basement membrane thickening, resulting in tissue ischaemia. Moreover, their altered interactions with endothelial cells are likely to cause abnormal and inadequate neovascularisation in diverse vascular beds. Further research is needed to identify mechanisms by which pericyte function is altered by diabetes, with a view to developing therapeutic approaches that normalise vascular function and remodelling.
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Affiliation(s)
- Nele Warmke
- Leeds Institute of Cardiovascular and Metabolic Medicine, LIGHT laboratories, The University of Leeds, Clarendon Way, Leeds, LS2 9JT, United Kingdom
| | - Kathryn J Griffin
- Leeds Institute of Cardiovascular and Metabolic Medicine, LIGHT laboratories, The University of Leeds, Clarendon Way, Leeds, LS2 9JT, United Kingdom
| | - Richard M Cubbon
- Leeds Institute of Cardiovascular and Metabolic Medicine, LIGHT laboratories, The University of Leeds, Clarendon Way, Leeds, LS2 9JT, United Kingdom.
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