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da Silva RA, Roda VMDP, Akamine PS, da Silva DS, Siqueira PV, Matsuda M, Hamassaki DE. Blockade of the TGF-β pathway by galunisertib inhibits the glial-mesenchymal transition in Müller glial cells. Exp Eye Res 2023; 226:109336. [PMID: 36455675 DOI: 10.1016/j.exer.2022.109336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 11/09/2022] [Accepted: 11/19/2022] [Indexed: 11/30/2022]
Abstract
Aging increases the risks for developing fibrocontractile membranes on the retina, which causes significant macular distortion, as in the idiopathic epiretinal membrane (iERM). Retinal Müller glial cells are components of these membranes and may play a key role in the iERM pathogenesis. The transforming growth factor-β (TGF-β) induces Müller cell transdifferentiation into myofibroblast, reducing glial cell markers (glutamine synthetase, GS, and glial fibrillary acidic protein, GFAP) and increasing α-smooth muscle actin (α-SMA). Our aim was to investigate the effect of the TGF-β inhibitor galunisertib (LY2157299) on the glial-mesenchymal transition and contraction of Müller cells. MIO-M1 human Müller cells were treated with TGF-β1 (10 ng/mL), galunisertib (5, 10 and 20 μM) and TGF-β1+galunisertib for 24h and 48h. Galunisertib cytotoxicity was analyzed by MTT and trypan blue, and TGF-β1 blockade by phospho-SMAD3 immunofluorescence. Caspase-3 (cell death indicator), GS, GFAP and α-SMA expression was examined by immunofluorescence, Western blotting, and qPCR analysis. Cell contractility was determined by collagen gel contraction assay with Müller cells incorporated. Galunisertib did not show cytotoxicity at the concentrations evaluated and maintained the Müller cells phenotype, ensuring the GS expression. Galunisertib inhibited the TGF-β1 pathway by decreasing phospho-SMAD3 immunoreactivity, attenuated the α-SMA expression, and prevented the contraction of Müller cells in collagen gel. Although more studies are needed, in vitro assays suggest that galunisertib may be a potential candidate to attenuate the formation of fibrocontractile membranes and prevent retinal detachment and consequent loss of vision.
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Affiliation(s)
- Rafael André da Silva
- Department of Cell & Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Vinicius Moraes de Paiva Roda
- Department of Cell & Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Priscilla Sayami Akamine
- Department of Cell & Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Daniela Simões da Silva
- Department of Cell & Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Paula Veloso Siqueira
- Department of Cell & Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil
| | - Monique Matsuda
- Department of Cell & Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil; Laboratory of Investigation in Ophthalmology (LIM-33), Division of Ophthalmology, University of São Paulo Faculty of Medicine, São Paulo, SP, Brazil
| | - Dânia Emi Hamassaki
- Department of Cell & Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil.
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Feizi S, Alemzadeh-Ansari M, Karimian F, Esfandiari H. Use of erythropoietin in ophthalmology: a review. Surv Ophthalmol 2021; 67:427-439. [PMID: 34157346 DOI: 10.1016/j.survophthal.2021.06.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 06/08/2021] [Accepted: 06/14/2021] [Indexed: 12/17/2022]
Abstract
Erythropoietin (EPO) is a glycoprotein hormone that regulates hematopoiesis in the human body. The presence of EPO and its receptors in different tissues indicates that this hormone has extramedullary effects in other tissues, including the eye. We focus on the biological roles of this hormone in the development and normal physiologic functions of the eye. Furthermore, we explore the role of EPO in the management of different ocular diseases - including diabetic retinopathy, retinopathy of prematurity, inherited retinal degeneration, branch and central retinal vein occlusion, retinal detachment, traumatic optic neuropathy, optic neuritis, methanol optic neuropathy, nonarteritic anterior ischemic optic neuropathy, glaucoma, and scleral necrosis.
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Affiliation(s)
- Sepehr Feizi
- Ophthalmic Research Center, Department of Ophthalmology, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| | | | - Farid Karimian
- Ophthalmic Research Center, Department of Ophthalmology, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hamed Esfandiari
- Department of Ophthalmology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA
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Iwata Y, Sakai N, Nakajima Y, Oshima M, Nakagawa-Yoneda S, Ogura H, Sato K, Minami T, Kitajima S, Toyama T, Yamamura Y, Miyagawa T, Hara A, Shimizu M, Furuichi K, Wada T. Anti-fibrotic potential of erythropoietin signaling on bone marrow derived fibrotic cell. BMC Nephrol 2021; 22:203. [PMID: 34059008 PMCID: PMC8167964 DOI: 10.1186/s12882-021-02411-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Accepted: 05/13/2021] [Indexed: 11/10/2022] Open
Abstract
INTRODUCTION The number of patients with end stage kidney disease (ESKD) are increasing world-side. While interstitial fibrosis (IF) is a common step for the progression to ESKD, therapeutic options for IF is still limited in clinical settings. We have reported that bone marrow-derived fibrotic cell, fibrocyte, is involved in the pathogenesis of kidney fibrosis. Also recent studies revealed that erythropoietin has protective effect on kidney diseases. However, it is unknown whether erythropoietin (EPO) inhibits fibrosis in progressive kidney injury. Therefore, we explored the impacts of EPO on kidney fibrosis with focusing on fibrocyte. METHOD Fibrocyte was differentiated from peripheral mononuclear cells of healthy donor. Fibrocyte was stimulated with transforming growth factor beta (TGF)-β with/without EPO treatment. Moreover, the therapeutic effect of EPO was evaluated in murine unilateral ureteral obstruction (UUO) model. RESULT TGF-β stimulation increased the expression of COL1 mRNA in fibrocyte. EPO signal reduced the expression of COL1 mRNA in dose dependent manner. EPO reduced mitochondrial oxidative stress and ameliorated mitochondrial membrane depolarization induced by TGF-β stimulation. Moreover, EPO reduced the mRNA expression of mitochondria related molecules, TRAF6, in fibrocyte. In addition, the count of CD45+/αSMA + double-positive fibrocyte was decreased in the EPO-administered UUO kidneys. CONCLUSION EPO signals function to prevent kidney fibrosis, particularly in fibrocyte. Regulating the renal accumulation of fibrocyte is a part of the anti-fibrotic functions of EPO.
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Affiliation(s)
- Yasunori Iwata
- Division of Infection Control, Department of Nephrology and Laboratory Medicine, Kanazawa University, 13-1 Takara-machi, 920-8641, Kanazawa , Japan. .,Department of Nephrology and Laboratory Medicine, Kanazawa University, Kanazawa, Japan.
| | - Norihiko Sakai
- Department of Nephrology and Laboratory Medicine, Kanazawa University, Kanazawa, Japan.,Division of Blood Purification, Kanazawa University Hospital, Ishikawa, Kanazawa, Japan
| | - Yuki Nakajima
- Department of Nephrology and Laboratory Medicine, Kanazawa University, Kanazawa, Japan
| | - Megumi Oshima
- Department of Nephrology and Laboratory Medicine, Kanazawa University, Kanazawa, Japan
| | | | - Hisayuki Ogura
- Department of Nephrology and Laboratory Medicine, Kanazawa University, Kanazawa, Japan
| | - Koichi Sato
- Department of Nephrology and Laboratory Medicine, Kanazawa University, Kanazawa, Japan
| | - Taichiro Minami
- Department of Nephrology and Laboratory Medicine, Kanazawa University, Kanazawa, Japan
| | - Shinji Kitajima
- Department of Nephrology and Laboratory Medicine, Kanazawa University, Kanazawa, Japan.,Division of Blood Purification, Kanazawa University Hospital, Ishikawa, Kanazawa, Japan
| | - Tadashi Toyama
- Department of Nephrology and Laboratory Medicine, Kanazawa University, Kanazawa, Japan
| | - Yuta Yamamura
- Department of Nephrology and Laboratory Medicine, Kanazawa University, Kanazawa, Japan
| | - Taro Miyagawa
- Department of Nephrology and Laboratory Medicine, Kanazawa University, Kanazawa, Japan
| | - Akinori Hara
- Department of Nephrology and Laboratory Medicine, Kanazawa University, Kanazawa, Japan
| | - Miho Shimizu
- Department of Nephrology and Laboratory Medicine, Kanazawa University, Kanazawa, Japan
| | - Kengo Furuichi
- Division of Nephrology, Kanazawa Medical University School of Medicine, Ishikawa, Japan
| | - Takashi Wada
- Department of Nephrology and Laboratory Medicine, Kanazawa University, Kanazawa, Japan
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4
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Cytoprotective effects of erythropoietin: What about the lung? Biomed Pharmacother 2021; 139:111547. [PMID: 33831836 DOI: 10.1016/j.biopha.2021.111547] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 03/17/2021] [Accepted: 03/23/2021] [Indexed: 02/07/2023] Open
Abstract
Erythropoietin (Epo) is a pleiotropic cytokine, essential for erythropoiesis. Epo and its receptor (Epo-R) are produced by several tissues and it is now admitted that Epo displays other physiological functions than red blood cell synthesis. Indeed, Epo provides cytoprotective effects, which consist in prevention or fight against pathological processes. This perspective article reviews the various protective effects of Epo in several organs and tries to give a proof of concept about its effects in the lung. The tissue-protective effects of Epo could be a promising approach to limit the symptoms of acute and chronic lung diseases.
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Wang H, Li Y, Han S, Niu T. Analysis of multiple cytokines in aqueous humor of patients with idiopathic macular hole. BMC Ophthalmol 2021; 21:27. [PMID: 33430811 PMCID: PMC7802234 DOI: 10.1186/s12886-020-01782-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 12/21/2020] [Indexed: 12/15/2022] Open
Abstract
Background Idiopathic macular holes are common ophthalmic manifestations with unknown pathogenesis. Thus far, there has been minimal research regarding the causes of idiopathic macular holes, especially with respect to the underlying immune mechanism. To provide clarity regarding the treatment and prognosis of idiopathic macular holes, specifically regarding the levels of cytokines in affected patients, this study examined and analyzed multiple cytokine levels in aqueous humor from patients with idiopathic macular holes. Methods This comparative cross-sectional study included 38 patients in two groups: a cataract control group (n = 17) and an idiopathic macular hole group (n = 21). The levels of 48 cytokines in aqueous humor were detected by multiplex analysis with antibody-coupled magnetic beads. The Kolmogorov–Smirnov test was used to check whether the data were normally distributed; Student’s t-test and the Mann–Whitney U test were used to assess differences in cytokine levels between the two groups. Spearman correlation analysis was used to assess relationships among cytokine levels in the experimental group. Signaling pathways containing cytokines with significantly different expression in the experimental group were identified. Results There were significant differences in aqueous humor cytokine levels between patients with idiopathic macular holes and patients in the cataract control group. Notably, hepatocyte growth factor (p = 0.0001), GM-CSF (p = 0.0111), and IFN-γ (p = 0.0120) were significantly upregulated in the experimental group, while TNF-α (p = 0.0032), GRO-α (p < 0.0001), and MIF (p < 0.0001) were significantly downregulated in the experimental group. Furthermore, the GM-CSF level showed significant positive correlations with levels of IL-1 (r = 0.67904, p < 0.001), IL-4 (r = 0.76017, p < 0.001), and IFN-γ (r = 0.59922, p = 0.004097) in the experimental group. Moreover, the levels of nerve growth factor and hepatocyte growth factor showed a significant positive correlation (r = 0.64951, p = 0.001441) in the experimental group. Conclusions Patients with idiopathic macular holes showed significant variation in aqueous humor immune response after the onset of hole formation, including the recruitment of immune cells and regulation of cytokine expression. Our findings also suggest that it is not appropriate to use patients with macular holes as the control group in studies of aqueous humor cytokine levels in ophthalmic diseases.
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Affiliation(s)
- Heping Wang
- Department of Ophthalmology, The Fourth Hospital of Shenyang, 110016, Shenyang, Liaoning, People's Republic of China
| | - Yuqi Li
- University of Chinese Academy of Sciences, Beijing, People's Republic of China.,Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, Liaoning, People's Republic of China
| | - Song Han
- Department of Ophthalmology, The Fourth Hospital of Shenyang, 110016, Shenyang, Liaoning, People's Republic of China
| | - Tongtong Niu
- Department of Ophthalmology, The Fourth Hospital of Shenyang, 110016, Shenyang, Liaoning, People's Republic of China.
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Tuleta I, Frangogiannis NG. Diabetic fibrosis. Biochim Biophys Acta Mol Basis Dis 2020; 1867:166044. [PMID: 33378699 DOI: 10.1016/j.bbadis.2020.166044] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 11/25/2020] [Accepted: 12/07/2020] [Indexed: 12/13/2022]
Abstract
Diabetes-associated morbidity and mortality is predominantly due to complications of the disease that may cause debilitating conditions, such as heart and renal failure, hepatic insufficiency, retinopathy or peripheral neuropathy. Fibrosis, the excessive and inappropriate deposition of extracellular matrix in various tissues, is commonly found in patients with advanced type 1 or type 2 diabetes, and may contribute to organ dysfunction. Hyperglycemia, lipotoxic injury and insulin resistance activate a fibrotic response, not only through direct stimulation of matrix synthesis by fibroblasts, but also by promoting a fibrogenic phenotype in immune and vascular cells, and possibly also by triggering epithelial and endothelial cell conversion to a fibroblast-like phenotype. High glucose stimulates several fibrogenic pathways, triggering reactive oxygen species generation, stimulating neurohumoral responses, activating growth factor cascades (such as TGF-β/Smad3 and PDGFs), inducing pro-inflammatory cytokines and chemokines, generating advanced glycation end-products (AGEs) and stimulating the AGE-RAGE axis, and upregulating fibrogenic matricellular proteins. Although diabetes-activated fibrogenic signaling has common characteristics in various tissues, some organs, such as the heart, kidney and liver develop more pronounced and clinically significant fibrosis. This review manuscript summarizes current knowledge on the cellular and molecular pathways involved in diabetic fibrosis, discussing the fundamental links between metabolic perturbations and fibrogenic activation, the basis for organ-specific differences, and the promises and challenges of anti-fibrotic therapies for diabetic patients.
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Affiliation(s)
- Izabela Tuleta
- The Wilf Family Cardiovascular Research Institute, Department of Medicine (Cardiology), Albert Einstein College of Medicine, Bronx, NY, USA
| | - Nikolaos G Frangogiannis
- The Wilf Family Cardiovascular Research Institute, Department of Medicine (Cardiology), Albert Einstein College of Medicine, Bronx, NY, USA.
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Zhang W, Kong Y. YAP is essential for TGF-β-induced retinal fibrosis in diabetic rats via promoting the fibrogenic activity of Müller cells. J Cell Mol Med 2020; 24:12390-12400. [PMID: 32951332 PMCID: PMC7686973 DOI: 10.1111/jcmm.15739] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 06/23/2020] [Accepted: 07/30/2020] [Indexed: 12/11/2022] Open
Abstract
The purpose of this study was to investigate whether Yes-associated protein (YAP) activation and proliferation of retinal Müller cells play a role in the development of TGF-β-induced retinal fibrosis. We studied the effects of YAP activation on retinal fibrosis in diabetic rats and human retinal Müller cells (hMCs) in vitro. The retinal expression of YAP and fibrogenic molecules in rats was detected using Western blotting and immunohistochemistry. After treatment with transforming growth factor-β1 (TGF-β1), the levels of fibrogenic molecules, and the activation of YAP and PI3K/Akt signalling pathway in hMCs were detected with Western blotting. The effect of YAP on retinal fibrotic changes was evaluated using YAP knockdown experiments and YAP inhibitors. Results showed that YAP expression was increased in the retina of diabetic rats along with increased retinal fibrosis. In cultured hMCs, YAP inhibition suppressed TGF-β1-stimulated hMC differentiation to myofibroblasts and extracellular matrix (ECM) production, while YAP activation promoted hMC differentiation and ECM production independent of TGF-β1. Furthermore, hMCs cultured on a gel with greater stiffness differentiated into myofibroblasts in a YAP-dependent manner. In diabetic rats, treatment with the YAP inhibitor verteporfin suppressed retinal fibrogenesis. In addition, the TGF-β1-induced PI3K/Akt signalling pathway mediated YAP activation as well as expression of fibrogenic molecules. The interaction between ECM stiffness and YAP forms a feed-forward process leading to retinal fibrosis. Our work highlights YAP as an essential regulator of pro-fibrotic responses in TGF-β-induced retinal fibrosis.
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Affiliation(s)
- Wei Zhang
- Tianjin Eye Hospital, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Institute, Clinical College of Ophthalmology Tianjin Medical University, Tianjin, China
| | - Yichun Kong
- Tianjin Eye Hospital, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Institute, Clinical College of Ophthalmology Tianjin Medical University, Tianjin, China.,Tianjin NanKai Hospital, NanKai Hospital, Tianjin Medical University, Nankai university affiliated Nankai hospital, Tianjin, China
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8
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Zhang W, Jiang H, Kong Y. Exosomes derived from platelet-rich plasma activate YAP and promote the fibrogenic activity of Müller cells via the PI3K/Akt pathway. Exp Eye Res 2020; 193:107973. [PMID: 32059976 DOI: 10.1016/j.exer.2020.107973] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Revised: 02/09/2020] [Accepted: 02/11/2020] [Indexed: 12/16/2022]
Abstract
The purpose of this study was to investigate the role of exosomes derived from platelet-rich plasma (PRP-Exos) in the regulation of the fibrogenic activity of Müller cells and the underlying mechanism. We studied the effects of PRP-Exos on the fibrogenic activity of human retinal Müller cells (hMCs) in vitro. PRP-Exos were isolated from the plasma of diabetic rats (DM-PRP-Exos) and normal control rats (Nor-PRP-Exos) and then observed by transmission electron microscopy. After treatment with DM-PRP-Exos or Nor-PRP-Exos, the proliferation and migration of hMCs were measured in vitro. Western blotting was conducted to assess the levels of fibrogenic molecules and activation of Yes-associated protein (YAP) and the PI3K-Akt signalling pathway. In cultured hMCs, DM-PRP-Exos but not Nor-PRP-Exos effectively increased the proliferative and migratory activities and improved connective tissue growth factor (CTGF) and fibronectin expression. Genetic and pharmacological suppression of YAP could reduce the proliferative and migratory activities of hMCs induced by DM-PRP-Exo. Additionally, YAP knockdown inhibited the DM-PRP-Exo-induced up-regulation of CTGF and fibronectin. Furthermore, DM-PRP-Exo-induced PI3K-Akt signalling mediated YAP activation and the expression of CTGF and fibronectin. In summary, DM-PRP-Exos, through YAP activation, enhance both the proliferation and fibrogenic activity of Müller cells via the PI3K/Akt pathway.
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Affiliation(s)
- Wei Zhang
- Tianjin Eye Hospital, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Institute, Clinical College of Ophthalmology Tianjin Medical University, Tianjin, 300020, China
| | - Hao Jiang
- Tianjin Eye Hospital, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Institute, Clinical College of Ophthalmology Tianjin Medical University, Tianjin, 300020, China
| | - Yichun Kong
- Tianjin Eye Hospital, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Institute, Clinical College of Ophthalmology Tianjin Medical University, Tianjin, 300020, China.
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9
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Siwu Granules and Erythropoietin Synergistically Ameliorated Anemia in Adenine-Induced Chronic Renal Failure Rats. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2019; 2019:5832105. [PMID: 31915448 PMCID: PMC6931032 DOI: 10.1155/2019/5832105] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 10/19/2019] [Accepted: 11/02/2019] [Indexed: 12/27/2022]
Abstract
Objective Renal anemia in patients with end-stage chronic kidney disease is closely related to the deterioration of cardiac function, renal function, and quality of life. This study involved adenine-induced renal anemic rat models and evaluated the treatment effect of Siwu granules and/or erythropoietin (EPO). Methods Fifty SD rats were randomly divided into 5 groups: control, model, Siwu, EPO, and Siwu plus EPO groups. The expression levels of NO, MDA, SOD, CAT, IL-6, TNF-α, EPO, EPOR, α-SMA, and TGF-β1 were detected in rats after 8 weeks of treatment with Siwu granules and/or EPO. Results After modeling, 47 rats entered the stage of treatment. Siwu plus EPO treatment significantly increased the rat hemoglobin content (p < 0.05) and reduced blood urea nitrogen (p < 0.05) and serum creatinine (p < 0.001). Compared with the control group, the expression of EPO and EPOR in the kidney of rats with renal failure was significantly decreased (p < 0.05). Moreover, the Siwu plus EPO group improved the level of oxidative stress in rats with chronic renal failure and reduced the expression of inflammatory factors. The expression of α-SMA and TGF-β1 in rats with renal failure was higher, but there was no expression in the control group. Conclusion Combined treatment of Siwu granules with EPO increased the expression of EPO and EPOR in the renal tissues and inhibited oxidative stress and inflammatory factors, improving the renal function and anemia.
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Tao YJ, Chen Q, Wang L, Yang X, Cun Q, Yang WY, Zhong H. Pirfenidone suppresses the abnormal activation of human Müller cells after platelet-derived growth factor-BB stimulation. Int J Ophthalmol 2019; 12:1075-1082. [PMID: 31341795 DOI: 10.18240/ijo.2019.07.04] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Accepted: 03/11/2019] [Indexed: 02/02/2023] Open
Abstract
AIM To determine the effect of pirfenidone on the activated human Müller cells by platelet-derived growth factor-BB (PDGF-BB). METHODS The primary human Müller cells were separated from retinal tissues and established the pathogenic model by stimulated with PDGF-BB. The Müller cells behaviour of normal group and the model group was measured by MTT assay, Trypan blue assay, cell migration assay, and collagen contraction assay. The expression of transforming growth factor (TGF)-β1, -β2, and pigment epithelium-derived factor (PEDF) was estimated with real-time polymerase chain reaction (PCR), Western blot and immunofluorescence analyses. RESULTS A pathogenic/proliferative model of Müller cells was established by stimulating normal cultured Müller cells with 10 ng/mL PDGF-BB for 48h. After treated with 0.2 and 0.3 mg/mL pirfenidone, the proliferation, migration and collagen contraction was statistically significantly depressed in the model group compared with the normal groups. The expression levels of TGF-β1 and TGF-β2 were significantly down-regulated, while the PEDF expression was significantly up-regulated after treated with 0.2 and 0.3 mg/mL pirfenidone in the model group. CONCLUSION Pirfenidone effectively suppress the proliferation, migration and collagen contraction of the human Müller cells stimulated with PDGF-BB through down-regulation of TGF-β1/TGF-β2 and up-regulation of PEDF.
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Affiliation(s)
- Yi-Jin Tao
- Department of Ophthalmology, the First Affiliated Hospital of Kunming Medical University, Kunming 650031, Yunnan Province, China
| | - Qin Chen
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, Jiangsu Province, China
| | - Li Wang
- Department of Ophthalmology, the First Affiliated Hospital of Nanjing Medical University, Nanjing 210029, Jiangsu Province, China
| | - Xiao Yang
- Department of Ophthalmology, the First Affiliated Hospital of Kunming Medical University, Kunming 650031, Yunnan Province, China
| | - Qing Cun
- Department of Ophthalmology, the First Affiliated Hospital of Kunming Medical University, Kunming 650031, Yunnan Province, China
| | - Wen-Yan Yang
- Department of Ophthalmology, the First Affiliated Hospital of Kunming Medical University, Kunming 650031, Yunnan Province, China
| | - Hua Zhong
- Department of Ophthalmology, the First Affiliated Hospital of Kunming Medical University, Kunming 650031, Yunnan Province, China
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11
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Shen W, Lee SR, Yam M, Zhu L, Zhang T, Pye V, Mathai AE, Shibagaki K, Zhang JZ, Matsugi T, Gillies MC. A Combination Therapy Targeting Endoglin and VEGF-A Prevents Subretinal Fibro-Neovascularization Caused by Induced Müller Cell Disruption. Invest Ophthalmol Vis Sci 2019; 59:6075-6088. [PMID: 30592496 DOI: 10.1167/iovs.18-25628] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Subretinal fibroneovascularization is one of the most common causes of vision loss in neovascular AMD (nAMD). Anti-VEGF therapy effectively inhibits vascular leak and neovascularization but has little effect on fibrosis. This study aimed to identify a combination therapy to concurrently inhibit subretinal neovascularization and prevent fibrosis. Methods We generated transgenic mice in which induced disruption of Müller cells leads to subretinal neovascularization, which is reliably accompanied by subretinal fibrosis. We conducted Western blots and immunohistochemistry to study changes in transforming growth factor-β (TGFβ) signaling including endoglin, a coreceptor essential for TGFβ signaling, and then tested the effects of monthly intravitreal injection of anti-VEGF-A and anti-endoglin, either alone or in combination, on the development of subretinal fibroneovascularization in our transgenic mice. Results Müller cell disruption increased expression of TGFβ1, TGFβ type 1 receptor, and phosphorylated-Smad3. Endoglin was strongly expressed in subretinal fibroneovascular tissue. Fluorescein angiography and measurements of retinal vascular permeability indicated that intravitreal anti-VEGF-A in combination with anti-endoglin treatment more efficiently inhibited vascular leak compared with either monotherapy. Immunostaining of retinal wholemounts with antibodies against glial fibrillary acidic protein and ionized calcium binding adaptor molecule 1 indicated that the combination therapy also effectively prevented subretinal fibrosis and inhibited microglial activation. Luminex cytokine assays indicated that intravitreal anti-VEGF-A and anti-endoglin treatment, either alone or in combination, reduced the production of IL33 and macrophage inflammatory protein-3α. Conclusions Our findings offer a potentially novel combination approach to concurrently managing subretinal neovascularization and fibrosis in nAMD.
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Affiliation(s)
- Weiyong Shen
- The University of Sydney, Save Sight Institute Discipline of Ophthalmology, Sydney Medical School, Sydney, New South Wales, Australia
| | - So-Ra Lee
- The University of Sydney, Save Sight Institute Discipline of Ophthalmology, Sydney Medical School, Sydney, New South Wales, Australia
| | - Michelle Yam
- The University of Sydney, Save Sight Institute Discipline of Ophthalmology, Sydney Medical School, Sydney, New South Wales, Australia
| | - Ling Zhu
- The University of Sydney, Save Sight Institute Discipline of Ophthalmology, Sydney Medical School, Sydney, New South Wales, Australia
| | - Ting Zhang
- The University of Sydney, Save Sight Institute Discipline of Ophthalmology, Sydney Medical School, Sydney, New South Wales, Australia
| | - Victoria Pye
- The University of Sydney, Save Sight Institute Discipline of Ophthalmology, Sydney Medical School, Sydney, New South Wales, Australia
| | - Ashish Easow Mathai
- The University of Sydney, Save Sight Institute Discipline of Ophthalmology, Sydney Medical School, Sydney, New South Wales, Australia
| | - Keiichi Shibagaki
- Department of Non-Clinical Research, Global R&D, Santen Pharmaceutical Co. Ltd., Nara, Japan
| | - Jin-Zhong Zhang
- Department of Non-Clinical Research, Global R&D, Santen Pharmaceutical Co. Ltd., Nara, Japan
| | - Takeshi Matsugi
- Department of Non-Clinical Research, Global R&D, Santen Pharmaceutical Co. Ltd., Nara, Japan
| | - Mark C Gillies
- The University of Sydney, Save Sight Institute Discipline of Ophthalmology, Sydney Medical School, Sydney, New South Wales, Australia
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12
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Ma T, Dong LJ, Du XL, Niu R, Hu BJ. Research progress on the role of connective tissue growth factor in fibrosis of diabetic retinopathy. Int J Ophthalmol 2018; 11:1550-1554. [PMID: 30225233 DOI: 10.18240/ijo.2018.09.20] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2018] [Accepted: 03/15/2018] [Indexed: 01/03/2023] Open
Abstract
Diabetic retinopathy (DR) is one of the most important types of diabetic microangiopathy, which is a specific change of fundus lesions and is one of the most serious complications of diabetes. When DR develops to proliferative DR, the main factors of decreasing vision, and even blindness, include retinal detachment and vitreous hemorrhage caused by contraction of blood vessels by fiber membrane. Recent studies reported that the formation of fiber vascular membrane is closely related to retinal fibrosis. The connective tissue growth factor (CTGF) is a cytokine that is closely related to DR fibrosis. However, its mechanism is poorly understood. This paper summarizes the recent studies about CTGF on DR fibrosis for a comprehensive understanding of the role and mechanism of CTGF in PDR.
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Affiliation(s)
- Teng Ma
- Tianjin Medical University Eye Hospital, Tianjin Medical University Eye Institute, Ophthalmology College of Tianjin Medical University, Tianjin 300384, China
| | - Li-Jie Dong
- Tianjin Medical University Eye Hospital, Tianjin Medical University Eye Institute, Ophthalmology College of Tianjin Medical University, Tianjin 300384, China
| | - Xue-Li Du
- Tianjin Medical University Eye Hospital, Tianjin Medical University Eye Institute, Ophthalmology College of Tianjin Medical University, Tianjin 300384, China
| | - Rui Niu
- Tianjin Medical University Eye Hospital, Tianjin Medical University Eye Institute, Ophthalmology College of Tianjin Medical University, Tianjin 300384, China
| | - Bo-Jie Hu
- Tianjin Medical University Eye Hospital, Tianjin Medical University Eye Institute, Ophthalmology College of Tianjin Medical University, Tianjin 300384, China
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13
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Pena J, Dulger N, Singh T, Zhou J, Majeska R, Redenti S, Vazquez M. Controlled microenvironments to evaluate chemotactic properties of cultured Müller glia. Exp Eye Res 2018; 173:129-137. [PMID: 29753729 DOI: 10.1016/j.exer.2018.05.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2018] [Revised: 05/08/2018] [Accepted: 05/09/2018] [Indexed: 12/20/2022]
Abstract
Emerging therapies have begun to evaluate the abilities of Müller glial cells (MGCs) to protect and/or regenerate neurons following retina injury. The migration of donor cells is central to many reparative strategies, where cells must achieve appropriate positioning to facilitate localized repair. Although chemical cues have been implicated in the MGC migratory responses of numerous retinopathies, MGC-based therapies have yet to explore the extent to which external biochemical stimuli can direct MGC behavior. The current study uses a microfluidics-based assay to evaluate the migration of cultured rMC-1 cells (as model MGC) in response to quantitatively-controlled microenvironments of signaling factors implicated in retinal regeneration: basic Fibroblast Growth factor (bFGF or FGF2); Fibroblast Growth factor 8 (FGF8); Vascular Endothelial Growth Factor (VEGF); and Epidermal Growth Factor (EGF). Findings indicate that rMC-1 cells exhibited minimal motility in response to FGF2, FGF8 and VEGF, but highly-directional migration in response to EGF. Further, the responses were blocked by inhibitors of EGF-R and of the MAPK signaling pathway. Significantly, microfluidics data demonstrate that changes in the EGF gradient (i.e. change in EGF concentration over distance) resulted in the directional chemotactic migration of the cells. By contrast, small increases in EGF concentration, alone, resulted in non-directional cell motility, or chemokinesis. This microfluidics-enhanced approach, incorporating the ability both to modulate and asses the responses of motile donor cells to a range of potential chemotactic stimuli, can be applied to potential donor cell populations obtained directly from human specimens, and readily expanded to incorporate drug-eluting biomaterials and combinations of desired ligands.
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Affiliation(s)
- Juan Pena
- The City College of New York, Department of Biomedical Engineering, 160 Convent Ave., Steinman Hall ST-403D, New York, NY, 10031, USA
| | - Nihan Dulger
- The City College of New York, Department of Biomedical Engineering, 160 Convent Ave., Steinman Hall ST-403D, New York, NY, 10031, USA
| | - Tanya Singh
- The City College of New York, Department of Biomedical Engineering, 160 Convent Ave., Steinman Hall ST-403D, New York, NY, 10031, USA
| | - Jing Zhou
- Lehman College, Department of Biology, 250 Bedford Park Blvd, Bronx, NY, 10468, USA
| | - Robert Majeska
- The City College of New York, Department of Biomedical Engineering, 160 Convent Ave., Steinman Hall ST-403D, New York, NY, 10031, USA
| | - Stephen Redenti
- Lehman College, Department of Biology, 250 Bedford Park Blvd, Bronx, NY, 10468, USA; The Graduate Center of the City University of New York, New York, NY, 10016, USA
| | - Maribel Vazquez
- The City College of New York, Department of Biomedical Engineering, 160 Convent Ave., Steinman Hall ST-403D, New York, NY, 10031, USA; The Graduate Center of the City University of New York, New York, NY, 10016, USA.
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14
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Preliminary Study of Bone Marrow-Derived Mesenchymal Stem Cells Pretreatment With Erythropoietin in Preventing Acute Rejection After Rat Renal Transplantation. Transplant Proc 2018; 50:3873-3880. [PMID: 30577280 DOI: 10.1016/j.transproceed.2018.04.063] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Revised: 04/05/2018] [Accepted: 04/27/2018] [Indexed: 12/21/2022]
Abstract
Renal transplantation is currently the most effective treatment for end-stage kidney diseases, and acute allograft rejection is well treated with high dose prednisolone and immunosuppressive agents, but long-term use of immunosuppressants will be detrimental to the long-term survival of the transplanted kidney and will have many side effects on the human body. Thus, a local and alloantigen-specific immunological tolerance may be a promising approach to improving kidney transplantation. The aim of this study is to examine the therapeutic potential of transforming bone marrow-derived mesenchymal stem cells (BMSCs) pretreated with erythropoietin (EPO) in inducing immunosuppression in renal grafts after transplantation. The immunity suppression effects were tested, focusing on the decrease of serum creatinine and the cells' ability to regulate the expression of the cytokines associated with acute rejection. Our findings demonstrate that a transfusion of BMSCs pretreated with EPO (EPO-BMSCs) can produce an immunosuppressive effect and reduce the occurrence of acute rejection. Their reciprocal effects on the induction and function of regulatory T cells (Tregs) resulted in the balance of IFN-γ/IL-4 and improved immunosuppressive effects in local kidney grafts. Our data also suggest that the acute rejection microenvironment had a directional chemotactic effect on BMSCs, which is related to the upregulation of CXCR4, and could be further enhanced by EPO treatment. Thus, transfusion of EPO-BMSCs can induce a greater local immunosuppressive effect in renal grafts after transplantation compared with untreated BMSCs. Therefore, transplantation with EPO-BMSCs can be a novel and effective approach to lower the acute rejection ratio following transplantation.
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15
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Zhou T, Che D, Lan Y, Fang Z, Xie J, Gong H, Li C, Feng J, Hong H, Qi W, Ma C, Yang Z, Cai W, Zhong J, Ma J, Yang X, Gao G. Mesenchymal marker expression is elevated in Müller cells exposed to high glucose and in animal models of diabetic retinopathy. Oncotarget 2018; 8:4582-4594. [PMID: 27999189 PMCID: PMC5354856 DOI: 10.18632/oncotarget.13945] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2016] [Accepted: 12/01/2016] [Indexed: 12/21/2022] Open
Abstract
Müller cells are retinal glial cells and exhibit a fibroblast-like phenotype and ability to migrate in diabetic retinopathy (DR). However, expression of mesenchymal markers, which promote fibrosis in various organs, has not been characterized in the diabetic retina. We examined changes in the expression of these markers in Müller cells exposed to high glucose and in animal models of diabetic retinopathy. High glucose conditions increased mesenchymal maker expression and migration in Müller cells. Snail, N-cadherin, Vimentin, β-catenin, and α-smooth muscle actin (α-SMA) levels were all dramatically increased in retinas from humans with diabetic retinopathy (DR) and from DR mouse models. In addition, Snail overexpression increased the expression of connective tissue growth factor (CTGF) and fibronectin, while Snail knockdown attenuated high glucose-induced increases in fibronectin and CTGF expression. These results demonstrate for the first time that mesenchymal markers are upregulated in retinas from a diabetic mouse model, and that Snail and N-cadherin levels are also increased in Müller cells exposed to high glucose. This suggests mesenchymal proteins may play a crucial role in the development of DR.
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Affiliation(s)
- Ti Zhou
- Program of Molecular Medicine, Affiliated Guangzhou Women and Children's Hospital, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China.,Department of Biochemistry, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Di Che
- Program of Molecular Medicine, Affiliated Guangzhou Women and Children's Hospital, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China.,Department of Biochemistry, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Yuqing Lan
- Department of Ophthalmology, Second Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Zhenzhen Fang
- Department of Biochemistry, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Jinye Xie
- Department of Biochemistry, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - HaiJun Gong
- Department of Ophthalmology, Second Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China
| | - ChaoYang Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Juan Feng
- Department of Biochemistry, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Honghai Hong
- Department of Biochemistry, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Weiwei Qi
- Department of Biochemistry, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Caiqi Ma
- Department of Biochemistry, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Zhonghan Yang
- Program of Molecular Medicine, Affiliated Guangzhou Women and Children's Hospital, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China
| | - WeiBin Cai
- Guangdong Engineering and Technology Research Center for Disease-Model Animals, Sun Yat-Sen University, Guangzhou, China
| | - Jun Zhong
- Program of Molecular Medicine, Affiliated Guangzhou Women and Children's Hospital, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China
| | - Jianxing Ma
- Department of Physiology, University of Oklahoma, Health Sciences Center, Oklahoma City, Oklahoma, USA
| | - Xia Yang
- Program of Molecular Medicine, Affiliated Guangzhou Women and Children's Hospital, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China.,Key Laboratory of Functional Molecules from Marine Microorganisms (Sun Yat-sen University), Department of Education of Guangdong Province, Guangzhou, China
| | - Guoquan Gao
- Program of Molecular Medicine, Affiliated Guangzhou Women and Children's Hospital, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, China.,Department of Biochemistry, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China.,China Key Laboratory of Tropical Disease Control (Sun Yat-sen University), Ministry of Education, Guangzhou, China
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16
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Ling L, Chen L, Zhang C, Gui S, Zhao H, Li Z. High glucose induces podocyte epithelial‑to‑mesenchymal transition by demethylation‑mediated enhancement of MMP9 expression. Mol Med Rep 2018; 17:5642-5651. [PMID: 29436620 PMCID: PMC5866005 DOI: 10.3892/mmr.2018.8554] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 10/30/2017] [Indexed: 01/13/2023] Open
Abstract
Abnormal expression of matrix metalloproteinase 9 (MMP9) is correlated with podocyte epithelial-to-mesenchymal transition (EMT) in diabetic nephropathy (DN). However, the mechanisms underlying this process are not well defined. Site-specific demethylation may sustain high expression levels of target genes. In the present study, in order to investigate the association between DNA demethylation of MMP9 promoter and podocyte EMT in DN, human podocytes were cultured in high-glucose (HG) medium and a rat model of DN was established by intraperitoneal injection of streptozotocin (STZ) to determine whether site-specific demethylation of the MMP9 promoter was involved in regulating podocyte EMT in DN. The MTT assay was used to assess the effects of HG culture on the growth of podocytes, and the demethylation status of the MMP9 promoter was assessed by bisulfite sequencing polymerase chain reaction. mRNA and protein expression levels of MMP9, α-smooth muscle actin (α-SMA), podocalyxin and fibronectin-1 in podocytes were assessed by reverse transcription-quantitative PCR (RT-qPCR) and western blot analyses. The results demonstrated that HG treatment up regulated the expression of MMP9, α-SMA and fibronectin-1, but down regulated the expression of podocalyxin in podocytes. The MMP9 promoter region was revealed to contain a variety of demethylated CpG sites, and HG treatment reduced the rate of MMP9 promotermethylation, which, in turn, enhanced its promoter activity. In summary, these data suggested that demethylation of the MMP9 promoter may serve an important role in podocyte EMT in DN. The demethylation status of the MMP9 promoter maybe used as an important prognostic marker of DN in clinic.
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Affiliation(s)
- Li Ling
- Department of Endocrinology, Guangdong Medical College Affiliated Shenzhen Nanshan Hospital, Shenzhen, Guangdong 518052, P.R. China
| | - Libo Chen
- Department of Endocrinology, Guangdong Medical College Affiliated Shenzhen Nanshan Hospital, Shenzhen, Guangdong 518052, P.R. China
| | - Changning Zhang
- Department of Endocrinology, Guangdong Medical College Affiliated Shenzhen Nanshan Hospital, Shenzhen, Guangdong 518052, P.R. China
| | - Shuyan Gui
- Department of Endocrinology, Guangdong Medical College Affiliated Shenzhen Nanshan Hospital, Shenzhen, Guangdong 518052, P.R. China
| | - Haiyan Zhao
- Department of Endocrinology, Guangdong Medical College Affiliated Shenzhen Nanshan Hospital, Shenzhen, Guangdong 518052, P.R. China
| | - Zhengzhang Li
- Department of Endocrinology, Guangdong Medical College Affiliated Shenzhen Nanshan Hospital, Shenzhen, Guangdong 518052, P.R. China
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17
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Reid G, Lois N. Erythropoietin in diabetic retinopathy. Vision Res 2017; 139:237-242. [PMID: 28652140 DOI: 10.1016/j.visres.2017.05.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 05/21/2017] [Accepted: 05/24/2017] [Indexed: 12/19/2022]
Abstract
Over the past years, knowledge has expanded with regards to the multiple roles played by erythropoietin (EPO) in the body. Once believed to be a hormone synthesised in the kidney and involved only in the modulation of erythrocyte production, it is recognised now that EPO can be produced in many tissues, including the retina, and by many cells. In these tissues EPO is released in response to "tissue injury" and appears to have protective functions. Despite the extensive research conducted to date, the cues leading to release of EPO and its effects in the normal and diseased retina have not been fully elucidated. In vitro and in vivo experimental studies as well as small interventional clinical studies suggest a potential beneficial effect of externally administered EPO in early diabetic retinopathy and diabetic macular oedema. In contrast, controversy exists with regards to the possible use of EPO in proliferative diabetic retinopathy. Non-erythropoietic EPO-derived peptides, produced with the aim of increasing effectiveness and reducing side effects of EPO, are currently under investigation in early phase clinical trials.
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Affiliation(s)
- Gerard Reid
- Ophthalmology Department, Belfast Health and Social Care Trust, Royal Victoria Hospital, 274 Grosvenor Rd, Belfast BT12 6BA, UK
| | - Noemi Lois
- Ophthalmology Department, Belfast Health and Social Care Trust, Royal Victoria Hospital, 274 Grosvenor Rd, Belfast BT12 6BA, UK; Wellcome-Wolfson Institute for Experimental Medicine, Queen's University Belfast, 97 Lisburn Road, BT9 7BL Belfast, UK.
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