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Badrah MH, Abdelaaty TA, Imbaby SAE, Abdel-Fattah YH, Silim WM, El Feky AY. The relationship between vascular endothelial growth factor-A serum level and the severity of diabetic peripheral neuropathy. EGYPTIAN RHEUMATOLOGY AND REHABILITATION 2022. [DOI: 10.1186/s43166-022-00164-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Abstract
Background and aims
Diabetic peripheral neuropathy (DPN) is a common microvascular complication in type 2 diabetes mellitus (T2DM). The nerve fibers injury is caused by the interaction between metabolic and vascular factors. Vascular endothelial growth factor (VEGF) is an essential growth factor for vascular endothelial cells. We aimed to investigate the relation between VEGF-A serum level and the degree of DPN.
Results
This cross-sectional study was conducted on 81 patients with T2DM. Based on the combined clinical and electrophysiological assessment, 67 patients (82.7%) were diagnosed with peripheral neuropathy of which 32 patients (39.5%) had subclinical neuropathy, whereas 35 patients (43.2%) were confirmed cases of DPN. Patients with DPN had longer duration of DM and higher values of glycosylated hemoglobin (HbA1c). Although the mean serum VEGF-A level in diabetic patients without neuropathy was higher than that in diabetic patients with DPN, this difference did not reach statistical significance (P = 0.07). However, patients with subclinical DPN had significantly higher serum VEGF-A level compared to patients with confirmed DPN (P < 0.001).
Conclusion
DPN was found to be a common finding in the studied sample of T2DM patients. Longer duration of DM and poor glycemic control may be risk factors for development of severe DPN. Low VEGF-A serum levels may lead to more severe DPN in patients with T2DM.
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Kim Y, Kim M, Kim SD, Yoon N, Wang X, Bae GU, Song YS. Distribution of Neuroglobin in Pericytes is Associated with Blood-Brain Barrier Leakage against Cerebral Ischemia in Mice. Exp Neurobiol 2022; 31:289-298. [PMID: 36351839 PMCID: PMC9659490 DOI: 10.5607/en22001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 09/27/2022] [Accepted: 10/09/2022] [Indexed: 11/11/2022] Open
Abstract
With emerging data on the various functions of neuroglobin (Ngb), such as neuroprotection and neurogenesis, we investigated the role of Ngb in the neurovascular unit (NVU) of the brain. To study the distribution and function of Ngb after cerebral ischemia, transient middle cerebral artery occlusion (tMCAO) was performed in mice. Brain immunostaining and fluorescence-activated cell sorting were used to analyze the role of Ngb according to the location and cell type. In normal brain tissue, it was observed that Ngb was distributed not only in neurons but also around the brain’s blood vessels. Interestingly, Ngb was largely expressed in platelet-derived growth factor receptor β (PDGFRβ)-positive pericytes in the NVU. After tMCAO, Ngb levels were significantly decreased in the core of the infarct, and Ngb and PDGFRβ-positive pericytes were detached from the vasculature. In contrast, in the penumbra of the infarct, PDGFRβ-positive pericytes expressing Ngb were increased compared with that in the core of the infarct. Moreover, the cerebral blood vessels, which have Ngb-positive PDGFRβ pericytes, showed reduced blood-brain barrier (BBB) leakage after tMCAO. It showed that Ngb-positive PDGFRβ pericytes stayed around the endothelial cells and reduced the BBB leakage in the NVU. Our results indicate that Ngb may play a role in attenuating BBB leakage in part by its association with PDGFRβ. In this study, the distribution and function of Ngb in the pericytes of the cerebrovascular system have been elucidated, which contributes to the treatment of stroke through a new function of Ngb.
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Affiliation(s)
- Yeojin Kim
- Department of Pharmacology, College of Pharmacy, Drug Information Research Institute, Muscle Physiome Research Center, Sookmyung Women’s University, Seoul 04310, Korea
| | - Mingee Kim
- Department of Pharmacology, College of Pharmacy, Drug Information Research Institute, Muscle Physiome Research Center, Sookmyung Women’s University, Seoul 04310, Korea
| | - So-Dam Kim
- Department of Pharmacology, College of Pharmacy, Drug Information Research Institute, Muscle Physiome Research Center, Sookmyung Women’s University, Seoul 04310, Korea
| | - Naeun Yoon
- Department of Pharmacology, College of Pharmacy, Drug Information Research Institute, Muscle Physiome Research Center, Sookmyung Women’s University, Seoul 04310, Korea
| | - Xiaoying Wang
- Clinical Neuroscience Research Center, Department of Neurosurgery and Neurology, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Gyu-Un Bae
- Department of Pharmacology, College of Pharmacy, Drug Information Research Institute, Muscle Physiome Research Center, Sookmyung Women’s University, Seoul 04310, Korea
| | - Yun Seon Song
- Department of Pharmacology, College of Pharmacy, Drug Information Research Institute, Muscle Physiome Research Center, Sookmyung Women’s University, Seoul 04310, Korea
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Jalilian E, Elkin K, Shin SR. Novel Cell-Based and Tissue Engineering Approaches for Induction of Angiogenesis as an Alternative Therapy for Diabetic Retinopathy. Int J Mol Sci 2020; 21:E3496. [PMID: 32429094 PMCID: PMC7278952 DOI: 10.3390/ijms21103496] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Revised: 05/12/2020] [Accepted: 05/13/2020] [Indexed: 01/28/2023] Open
Abstract
Diabetic retinopathy (DR) is the most frequent microvascular complication of long-term diabetes and the most common cause of blindness, increasing morbidity in the working-age population. The most effective therapies for these complications include laser photocoagulation and anti-vascular endothelial growth factor (VEGF) intravitreal injections. However, laser and anti-VEGF drugs are untenable as a final solution as they fail to address the underlying neurovascular degeneration and ischemia. Regenerative medicine may be a more promising approach, aimed at the repair of blood vessels and reversal of retinal ischemia. Stem cell therapy has introduced a novel way to reverse the underlying ischemia present in microvascular complications in diseases such as diabetes. The present review discusses current treatments, their side effects, and novel cell-based and tissue engineering approaches as a potential alternative therapeutic approach.
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Affiliation(s)
- Elmira Jalilian
- UCL Institute of Ophthalmology, University College London, London EC1V 9EL, UK
| | - Kenneth Elkin
- Wayne State University School of Medicine, Detroit, MI 48201, USA;
| | - Su Ryon Shin
- Division of Engineering in Medicine, Department of Medicine, Harvard Medical School, Brigham and Women’s Hospital, Cambridge, MA 02139, USA;
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Alarcon-Martinez L, Yilmaz-Ozcan S, Yemisci M, Schallek J, Kılıç K, Villafranca-Baughman D, Can A, Di Polo A, Dalkara T. Retinal ischemia induces α-SMA-mediated capillary pericyte contraction coincident with perivascular glycogen depletion. Acta Neuropathol Commun 2019; 7:134. [PMID: 31429795 PMCID: PMC6701129 DOI: 10.1186/s40478-019-0761-z] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 06/26/2019] [Indexed: 12/21/2022] Open
Abstract
Increasing evidence indicates that pericytes are vulnerable cells, playing pathophysiological roles in various neurodegenerative processes. Microvascular pericytes contract during cerebral and coronary ischemia and do not relax after re-opening of the occluded artery, causing incomplete reperfusion. However, the cellular mechanisms underlying ischemia-induced pericyte contraction, its delayed emergence, and whether it is pharmacologically reversible are unclear. Here, we investigate i) whether ischemia-induced pericyte contractions are mediated by alpha-smooth muscle actin (α-SMA), ii) the sources of calcium rise in ischemic pericytes, and iii) if peri-microvascular glycogen can support pericyte metabolism during ischemia. Thus, we examined pericyte contractility in response to retinal ischemia both in vivo, using adaptive optics scanning light ophthalmoscopy and, ex vivo, using an unbiased stereological approach. We found that microvascular constrictions were associated with increased calcium in pericytes as detected by a genetically encoded calcium indicator (NG2-GCaMP6) or a fluoroprobe (Fluo-4). Knocking down α-SMA expression with RNA interference or fixing F-actin with phalloidin or calcium antagonist amlodipine prevented constrictions, suggesting that constrictions resulted from calcium- and α-SMA-mediated pericyte contractions. Carbenoxolone or a Cx43-selective peptide blocker also reduced calcium rise, consistent with involvement of gap junction-mediated mechanisms in addition to voltage-gated calcium channels. Pericyte calcium increase and capillary constrictions became significant after 1 h of ischemia and were coincident with depletion of peri-microvascular glycogen, suggesting that glucose derived from glycogen granules could support pericyte metabolism and delay ischemia-induced microvascular dysfunction. Indeed, capillary constrictions emerged earlier when glycogen breakdown was pharmacologically inhibited. Constrictions persisted despite recanalization but were reversible with pericyte-relaxant adenosine administered during recanalization. Our study demonstrates that retinal ischemia, a common cause of blindness, induces α-SMA- and calcium-mediated persistent pericyte contraction, which can be delayed by glucose driven from peri-microvascular glycogen. These findings clarify the contractile nature of capillary pericytes and identify a novel metabolic collaboration between peri-microvascular end-feet and pericytes.
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Affiliation(s)
- Luis Alarcon-Martinez
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Sihhiye, 06100, Ankara, Turkey
- Department of Neuroscience and Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Université de Montréal, Montréal, Québec, Canada
| | - Sinem Yilmaz-Ozcan
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Sihhiye, 06100, Ankara, Turkey
| | - Muge Yemisci
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Sihhiye, 06100, Ankara, Turkey.
- Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey.
| | - Jesse Schallek
- Flaum Eye Institute and Center for Visual Science, University of Rochester, Rochester, New York, USA
| | - Kıvılcım Kılıç
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Sihhiye, 06100, Ankara, Turkey
| | - Deborah Villafranca-Baughman
- Department of Neuroscience and Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Université de Montréal, Montréal, Québec, Canada
| | - Alp Can
- Department of Histology and Embryology, School of Medicine, Ankara University, Ankara, Turkey
| | - Adriana Di Polo
- Department of Neuroscience and Centre de Recherche du Centre Hospitalier de l'Université de Montréal, Université de Montréal, Montréal, Québec, Canada
| | - Turgay Dalkara
- Institute of Neurological Sciences and Psychiatry, Hacettepe University, Sihhiye, 06100, Ankara, Turkey.
- Department of Neurology, Faculty of Medicine, Hacettepe University, Ankara, Turkey.
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Abstract
Recent stroke research has shifted the focus to the microvasculature from neuron-centric views. It is increasingly recognized that a successful neuroprotection is not feasible without microvascular protection. On the other hand, recent studies on pericytes, long-neglected cells on microvessels have provided insight into the regulation of microcirculation. Pericytes play an essential role in matching the metabolic demand of nervous tissue with the blood flow in addition to regulating the development and maintenance of the blood-brain barrier (BBB), leukocyte trafficking across the BBB and angiogenesis. Pericytes appears to be highly vulnerable to injury. Ischemic injury to pericytes on cerebral microvasculature unfavorably impacts the stroke-induced tissue damage and brain edema by disrupting microvascular blood flow and BBB integrity. Strongly supporting this, clinical imaging studies show that tissue reperfusion is not always obtained after recanalization. Therefore, prevention of pericyte dysfunction may improve the outcome of recanalization therapies by promoting microcirculatory reperfusion and preventing hemorrhage and edema. In the peri-infarct tissue, pericytes are detached from microvessels and promote angiogenesis and neurogenesis, and hence positively effect stroke outcome. Expectedly, we will learn more about the place of pericytes in CNS pathologies including stroke and devise approaches to treat them in the next decades.
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Li YH, Sheu WHH, Lee IT. Effects of retinopathy and chronic kidney disease on long-term mortality in type 2 diabetic inpatients with normal urinary albumin or protein: a retrospective cohort study. BMJ Open 2018; 8:e021655. [PMID: 30049696 PMCID: PMC6067336 DOI: 10.1136/bmjopen-2018-021655] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
OBJECTIVE Normoalbuminuric chronic kidney disease (NA-CKD) is recognised as a distinct phenotype of diabetic kidney disease, but the role of diabetic retinopathy (DR) in predicting long-term mortality among these patients remains unclear. Here, we aimed to investigate the effects of DR and CKD on mortality in type 2 diabetic patients with normoalbuminuria. DESIGN We conducted this study as a retrospective cohort study. SETTING We collected clinical information from the medical records of a public medical centre in central Taiwan. PARTICIPANTS Patients with type 2 diabetes (n=665) who were hospitalised due to poor glucose control were consecutively enrolled and followed for a median of 6.7 years (IQR 4.1‒9.6 years). Patients with either urinary protein excretion >150 mg/day or urine albumin excretion >30 mg/day were excluded. PRIMARY OUTCOME MEASURE All-cause mortality served as the primary follow-up outcome, and the mortality data were obtained from the national registry in Taiwan. RESULTS The patients with CKD and DR showed the highest mortality rate (log-rank p<0.001). The risks of all-cause mortality (HR 2.263; 95% CI 1.551 to 3.302) and cardiovascular mortality (HR 2.471; 95% CI 1.421 to 4.297) were significantly greater in patients with CKD and DR than in those without CKD or DR, after adjusting for the associated risk factors. CONCLUSIONS DR is an independent predictor for all-cause and cardiovascular mortality in type 2 diabetic inpatients with normoalbuminuria. Moreover, DR with CKD shows the highest risks of all-cause and cardiovascular mortality among these patients. Funduscopy screening can provide additive information on mortality in patients with type 2 diabetes, even among those with NA-CKD.
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Affiliation(s)
- Yu-Hsuan Li
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, Taiwan
| | - Wayne H-H Sheu
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, Taiwan
- School of Medicine, National Yang-Ming University, Taipei, Taiwan
| | - I-Te Lee
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, Taiwan
- School of Medicine, National Yang-Ming University, Taipei, Taiwan
- School of Medicine, Chung Shan Medical University, Taichung, Taiwan
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Tan X, Chen C, Zhu Y, Deng J, Qiu X, Huang S, Shang F, Cheng B, Liu Y. Proteotoxic Stress Desensitizes TGF-beta Signaling Through Receptor Downregulation in Retinal Pigment Epithelial Cells. Curr Mol Med 2018. [PMID: 28625142 PMCID: PMC5688417 DOI: 10.2174/1566524017666170619113435] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Background: Proteotoxic stress and transforming growth factor (TGFβ)-induced epithelial-mesenchymal transition (EMT) are two main contributors of intraocular fibrotic disorders, including proliferative vitreoretinopathy (PVR) and proliferative diabetic retinopathy (PDR). However, how these two factors communicate with each other is not well-characterized. Objective: The aim was to investigate the regulatory role of proteotoxic stress on TGFβ signaling in retinal pigment epithelium. Methods: ARPE-19 cells and primary human retinal pigment epithelial (RPE) cells were treated with proteasome inhibitor MG132 and TGFβ. Cell proliferation was analyzed by CCK-8 assay. The levels of mesenchymal markers α-SMA, fibronectin, and vimentin were analyzed by real-time polymerase chain reaction (PCR), western blot, and immunofluorescence. Cell migration was analyzed by scratch wound assay. The levels of p-Smad2, total Smad2, p-extracellular signal-regulated kinase 1/2 (ERK1/2), total ERK1/2, p-focal adhesion kinase (FAK), and total FAK were analyzed by western blot. The mRNA and protein levels of TGFβ receptor-II (TGFβR-II) were measured by real-time PCR and western blot, respectively. Results: MG132-induced proteotoxic stress resulted in reduced cell proliferation. MG132 significantly suppressed TGFβ-induced upregulation of α-SMA, fibronectin, and vimentin, as well as TGFβ-induced cell migration. The phosphorylation levels of Smad2, ERK1/2, and FAK were also suppressed by MG132. Additionally, the mRNA level and protein level of TGFβR-II decreased upon MG132 treatment. Conclusion: Proteotoxic stress suppressed TGFβ-induced EMT through downregulation of TGFβR-II and subsequent blockade of Smad2, ERK1/2, and FAK activation.
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Affiliation(s)
- X Tan
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong. China
| | - C Chen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong. China
| | - Y Zhu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong. China
| | - J Deng
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong. China
| | - X Qiu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong. China
| | - S Huang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong. China
| | - F Shang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong. China
| | - B Cheng
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 54 South Xianlie Road, Guangzhou, 510060. China
| | - Y Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 54 South Xianlie Road, Guangzhou, 510060. China
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Mei X, Zhou L, Zhang T, Lu B, Sheng Y, Ji L. Chlorogenic acid attenuates diabetic retinopathy by reducing VEGF expression and inhibiting VEGF-mediated retinal neoangiogenesis. Vascul Pharmacol 2018; 101:29-37. [DOI: 10.1016/j.vph.2017.11.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 10/11/2017] [Accepted: 11/11/2017] [Indexed: 11/30/2022]
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Fan K, Li S, Liu G, Yuan H, Ma L, Lu P. Tanshinone IIA inhibits high glucose-induced proliferation, migration and vascularization of human retinal endothelial cells. Mol Med Rep 2017; 16:9023-9028. [DOI: 10.3892/mmr.2017.7743] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 08/21/2017] [Indexed: 11/05/2022] Open
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Kimura K, Orita T, Kobayashi Y, Matsuyama S, Fujimoto K, Yamauchi K. Concentration of acute phase factors in vitreous fluid in diabetic macular edema. Jpn J Ophthalmol 2017; 61:479-483. [PMID: 28755024 DOI: 10.1007/s10384-017-0525-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 05/22/2017] [Indexed: 11/25/2022]
Abstract
PURPOSE Diabetic retinal maculopathy is associated with acute and chronic local inflammation. We measured the concentrations of acute phase factors in vitreous fluid of patients with diabetic macular edema (DME) and examined their relations to visual acuity and central retinal thickness (CRT) both before and after vitrectomy. STUDY DESIGN Retrospective. METHODS Vitreous fluid was collected during vitreoretinal surgery from 19 patients with DME and 12 control subjects with epiretinal membrane. The concentrations of acute phase factors (α2-macroglobulin, haptoglobin, C-reactive protein, serum amyloid P and A, procalcitonin, ferritin, tissue plasminogen activator, fibrinogen) and vascular endothelial growth factor (VEGF) were measured with multiplex assays. CRT of macular edema was measured by optical coherence tomography (OCT). RESULTS The levels of serum amyloid P, procalcitonin, ferritin, and fibrinogen in vitreous fluid were increased in DME patients compared with control subjects. The levels of procalcitonin and fibrinogen in DME patients were inversely correlated with visual acuity both before and 3 months after vitrectomy but not 6 months postsurgery. The concentrations of these four factors were not correlated with either CRT or the vitreous levels of VEGF in DME patients. CONCLUSION Acute phase factors may contribute to local inflammation in DME and may therefore influence disease progression.
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Affiliation(s)
- Kazuhiro Kimura
- Department of Ophthalmology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube, Yamaguchi, 755-8505, Japan.
| | - Tomoko Orita
- Department of Ophthalmology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Yuka Kobayashi
- Department of Ophthalmology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube, Yamaguchi, 755-8505, Japan
| | - Shigeo Matsuyama
- Jyousaigaoka Eye Clinic, 3-1-1 Inamoto Munakata, Fukuoka, 811-3406, Japan
| | - Kazushi Fujimoto
- Fujimoto Eye Clinic, 3-6-9 Taharashinmachi, Kokuraminami Ward, Kitakyushu, Fukuoka, 800-0226, Japan
| | - Kazuhiko Yamauchi
- Department of Ophthalmology, Japanese Red Cross Yamaguchi Hospital, 53-1 Yawatanobaba, Yamaguchi, Yamaguchi, 753-0092, Japan
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Activated microglia induce the production of reactive oxygen species and promote apoptosis of co-cultured retinal microvascular pericytes. Graefes Arch Clin Exp Ophthalmol 2017; 255:777-788. [PMID: 28074262 DOI: 10.1007/s00417-016-3578-5] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 12/18/2016] [Accepted: 12/28/2016] [Indexed: 12/22/2022] Open
Abstract
PURPOSE Pericyte apoptosis is a predominant feature of early diabetic retinopathy. In diabetic retinopathy, activated microglia migrate and release proinflammatory cytokines that contribute to disruption of the blood-retinal barrier, neuronal loss, and enhanced ROS production. Reactive oxygen species (ROS) are implicated in pericyte death; however, the mechanism by which activated microglia affect retinal microvascular pericytes is unclear. We hypothesized that activated microglia may promote pericyte apoptosis by enhancing ROS production. METHODS Lipopolysaccharide (LPS)-activated microglia and pericytes were co-cultured in a cell culture system. Pericyte ROS production and the mitochondrial membrane potential (ΔΨm) were determined by flow cytometry. The pericyte protein expression levels of NADPH oxidase subunits, uncoupling protein 2, nuclear NF-κB-p65, and caspase-3 were determined by western blotting. One-way ANOVAs were used for statistical analysis. RESULTS LPS successfully activated the microglia, as demonstrated by their morphological and phenotype changes and the significant increase in tumor necrosis factor secretion (P < 0.01). Co-culture with activated microglia significantly up-regulated NADPH oxidase subunits (NOX4, NOX2, and NCF1; P < 0.01) and down-regulated uncoupling protein 2 expression (P < 0.01) in pericytes. Pericyte ROS production increased by 20% in the activated microglia co-cultured group, and was inhibited by pretreatment with diphenyleneiodonium, coenzyme Q10, and N-acetylcysteine. The proapoptotic pericyte changes induced by co-culture with activated microglia included a 9.50% decrease in pericyte ΔΨm and significant increases in NF-κB-p65 nuclear translocation (P < 0.01) and activated caspase-3 (P < 0.01). These proapoptotic effects of activated microglia were inhibited by diphenyleneiodonium. CONCLUSIONS Our results are consistent with our hypothesis that activated microglia may promote pericyte apoptosis by enhancing ROS production. Further studies are needed to examine retinal microglia activation and the corresponding changes in pericytes in a rat model of diabetes mellitus.
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Cai W, Liu H, Zhao J, Chen LY, Chen J, Lu Z, Hu X. Pericytes in Brain Injury and Repair After Ischemic Stroke. Transl Stroke Res 2016; 8:107-121. [PMID: 27837475 DOI: 10.1007/s12975-016-0504-4] [Citation(s) in RCA: 114] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Revised: 10/09/2016] [Accepted: 10/13/2016] [Indexed: 01/02/2023]
Abstract
Pericytes are functional components of the neurovascular unit (NVU). They provide support to other NVU components and maintain normal physiological functions of the blood-brain barrier (BBB). The brain ischemia and reperfusion result in pathological alterations in pericytes. The intimate anatomical and functional interactions between pericytes and other NVU components play pivotal roles in the progression of stroke pathology. In this review, we depict the biology and functions of pericytes in the normal brain and discuss their effects in brain injury and repair after ischemia/reperfusion. Since ischemic stroke occurs mostly in elderly people, we also review age-related changes in pericytes and how these changes predispose aged brains to ischemic/reperfusion injury. Strategies targeting pericyte responses after ischemia and reperfusion may provide new therapies for ischemic stroke.
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Affiliation(s)
- Wei Cai
- Department of Neurology, Pittsburgh Institute of Brain Disorders and Recovery, University of Pittsburgh School of Medicine, 200 Lothrop Street, SBST 506, Pittsburgh, PA, 15213, USA.,Department of Neurology, The Third Affiliated Hospital of Sun Yatsen University, 600 Tianhe Road, Guangzhou, Guangdong, 510630, China
| | - Huan Liu
- Department of Neurology, Pittsburgh Institute of Brain Disorders and Recovery, University of Pittsburgh School of Medicine, 200 Lothrop Street, SBST 506, Pittsburgh, PA, 15213, USA
| | - Jingyan Zhao
- Department of Neurology, Pittsburgh Institute of Brain Disorders and Recovery, University of Pittsburgh School of Medicine, 200 Lothrop Street, SBST 506, Pittsburgh, PA, 15213, USA
| | - Lily Y Chen
- Department of Neurology, Pittsburgh Institute of Brain Disorders and Recovery, University of Pittsburgh School of Medicine, 200 Lothrop Street, SBST 506, Pittsburgh, PA, 15213, USA
| | - Jun Chen
- Department of Neurology, Pittsburgh Institute of Brain Disorders and Recovery, University of Pittsburgh School of Medicine, 200 Lothrop Street, SBST 506, Pittsburgh, PA, 15213, USA
| | - Zhengqi Lu
- Department of Neurology, The Third Affiliated Hospital of Sun Yatsen University, 600 Tianhe Road, Guangzhou, Guangdong, 510630, China.
| | - Xiaoming Hu
- Department of Neurology, Pittsburgh Institute of Brain Disorders and Recovery, University of Pittsburgh School of Medicine, 200 Lothrop Street, SBST 506, Pittsburgh, PA, 15213, USA.
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13
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Coroniti R, Farjo R, Nuno DJ, Otvos L, Scolaro L, Surmacz E. Designer Leptin Receptor Antagonist Allo-aca Inhibits VEGF Effects in Ophthalmic Neoangiogenesis Models. Front Mol Biosci 2016; 3:67. [PMID: 27790618 PMCID: PMC5062870 DOI: 10.3389/fmolb.2016.00067] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 09/27/2016] [Indexed: 12/16/2022] Open
Abstract
Experimental and clinical data suggest that pro-angiogenic, pro-inflammatory and mitogenic cytokine leptin can be implicated in ocular neovascularization and other eye pathologies. At least in part, leptin action appears to be mediated through functional interplay with vascular endothelial growth factor (VEGF). VEGF is a potent regulator of neoangiogenesis and vascular leakage with a proven role in conditions such as proliferative diabetic retinopathy, age-related macular degeneration and diabetic macular edema. Accordingly, drugs targeting VEGF are becoming mainstream treatments for these diseases. The crosstalk between leptin and VEGF has been noted in different tissues, but its involvement in the development of eye pathologies is unclear. Leptin is coexpressed with VEGF during ocular neovascularization and can potentiate VEGF synthesis and angiogenic function. However, whether or not VEGF regulates leptin expression or signaling has never been studied. Consequently, we addressed this aspect of leptin/VEGF crosstalk in ocular models, focusing on therapeutic exploration of underlying mechanisms. Here we show, for the first time, that in retinal (RF/6A) and corneal (BCE) endothelial cells, VEGF (100 ng/mL, 24 h) stimulated leptin mRNA synthesis by 70 and 30%, respectively, and protein expression by 56 and 28%, respectively. In parallel, VEGF induced RF/6A and BCE cell growth by 33 and 20%, respectively. In addition, VEGF upregulated chemotaxis and chemokinesis in retinal cells by ~40%. VEGF-dependent proliferation and migration were significantly reduced in the presence of the leptin receptor antagonist, Allo-aca, at 100-250 nmol/L concentrations. Furthermore, Allo-aca suppressed VEGF-dependent long-term (24 h), but not acute (15 min) stimulation of the Akt and ERK1/2 signaling pathways. The efficacy of Allo-aca was validated in the rat laser-induced choroidal neovascularization model where the compound (5 μg/eye) significantly reduced pathological vascularization with the efficacy similar to that of a standard treatment (anti-VEGF antibody, 1 μg/eye). Cumulatively, our results suggest that chronic exposure to VEGF upregulates leptin expression and function. As leptin can in turn activate VEGF, the increased abundance of both cytokines could amplify pro-angiogenic and pro-inflammatory environement in the eye. Thus, combined therapies targeting ObR and VEGF should be considered in the treatment of ocular diseases.
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Affiliation(s)
- Roberta Coroniti
- Sbarro Institute for Cancer Research and Molecular Medicine, Temple UniversityPhiladelphia, PA, USA
| | - Rafal Farjo
- Department of Biology, Temple UniversityPhiladelphia, PA, USA
| | - Didier J. Nuno
- Department of Biology, Temple UniversityPhiladelphia, PA, USA
| | | | - Laura Scolaro
- Sbarro Institute for Cancer Research and Molecular Medicine, Temple UniversityPhiladelphia, PA, USA
| | - Eva Surmacz
- Sbarro Institute for Cancer Research and Molecular Medicine, Temple UniversityPhiladelphia, PA, USA
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Erianin inhibits high glucose-induced retinal angiogenesis via blocking ERK1/2-regulated HIF-1α-VEGF/VEGFR2 signaling pathway. Sci Rep 2016; 6:34306. [PMID: 27678303 PMCID: PMC5039671 DOI: 10.1038/srep34306] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 09/07/2016] [Indexed: 12/14/2022] Open
Abstract
Erianin is a natural compound found in Dendrobium chrysotoxum Lindl. Diabetic retinopathy (DR) is a serious and common microvascular complication of diabetes. This study aims to investigate the inhibitory mechanism of erianin on retinal neoangiogenesis and its contribution to the amelioration of DR. Erianin blocked high glucose (HG)-induced tube formation and migration in choroid-retinal endothelial RF/6A cells. Erianin inhibited HG-induced vascular endothelial growth factor (VEGF) expression, hypoxia-inducible factor 1-alpha (HIF-1α) translocation into nucleus and ERK1/2 activation in RF/6A and microglia BV-2 cells. MEK1/2 inhibitor U0126 blocked HG-induced HIF-1α and ERK1/2 activation in both above two cells. In addition, erianin abrogated VEGF-induced angiogenesis in vitro and in vivo, and also inhibited VEGF-induced activation of VEGF receptor 2 (VEGFR2) and its downstream cRaf-MEK1/2-ERK1/2 and PI3K-AKT signaling pathways in RF/6A cells. Furthermore, erianin reduced the increased retinal vessels, VEGF expression and microglia activation in streptozotocin (STZ)-induced hyperglycemic and oxygen-induced retinopathy (OIR) mice. In conclusion, our results demonstrate that erianin inhibits retinal neoangiogenesis by abrogating HG-induced VEGF expression by blocking ERK1/2-mediated HIF-1α activation in retinal endothelial and microglial cells, and further suppressing VEGF-induced activation of VEGFR2 and its downstream signals in retinal endothelial cells.
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Zhou L, Zhang T, Lu B, Yu Z, Mei X, Abulizi P, Ji L. Lonicerae Japonicae Flos attenuates diabetic retinopathy by inhibiting retinal angiogenesis. JOURNAL OF ETHNOPHARMACOLOGY 2016; 189:117-25. [PMID: 27196298 DOI: 10.1016/j.jep.2016.05.039] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Revised: 03/14/2016] [Accepted: 05/16/2016] [Indexed: 05/21/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Lonicerae Japonicae Flos (Jin-Yin-Hua) is a well-known traditional Chinese medicine used for clearing away heat and toxic material. AIM OF THE STUDY This study aims to observe the attenuation of aqueous extract of Lonicerae Japonicae Flos (FL) against streptozotocin (STZ)-induced diabetic retinopathy (DR) and its engaged mechanism. MATERIALS AND METHODS STZ-induced proliferative DR (PDR) for 5 month in C57BL/6 mice was used in this study. Retinal vessels were observed by immunofluorescence staining with cluster of differentiation 31 (CD31) and histopathological evaluation. Enzyme-linked immunosorbent assay (ELISA) was used to detect serum vascular endothelial growth factor (VEGF) content. Cell proliferation was detected by 3-(4, 5-dimethylthiazol-2-yl) 2, 5-diphenyltetrazolium bromide (MTT) assay in choroid-retinal endothelial RF/6A cells. VEGF-induced tube formation in RF/6A cells was observed. The contents of chlorogenic acid (CGA), caffeic acid (CA), and luteolin in FL were detected by high-performance liquid chromatography (HPLC). RESULTS Histopathological evaluation demonstrated that retinal vessels were increased in STZ-induced PDR mice, whereas FL decreased such increase. The results of CD31 staining also showed that FL decreased the increased number of retinal vessels in STZ-induced PDR mice. In addition, FL reduced the increased serum VEGF content in STZ-induced PDR mice. FL reduced VEGF-induced RF/6A cell proliferation in the concentration-dependent manner, but had no obvious effect on RF/6A cell viability without VEGF stimulation. VEGF-induced tube formation in RF/6A cells was inhibited by different concentrations of FL. CGA, CA and luteolin all inhibited VEGF-induced tube formation in RF/6A cells, and the lowest effective concentration of CGA and CA was both 0.625μM, but of luteolin was 5μM. Furthermore, the results of HPLC demonstrated that the amount of CGA was the highest in FL. CONCLUSIONS FL ameliorates STZ-induced PDR by inhibiting retinal angiogenesis. Phenolic acid CGA is the main compound contributing to the inhibition of FL on retinal angiogenesis.
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Affiliation(s)
- Lingyu Zhou
- The Shanghai Key Laboratory for Complex Prescription, The MOE Key Laboratory for Standardization of Chinese Medicines, and The SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China; College of Pharmacy, Xinjiang Medical University, Urumqi 830011, China
| | - Tianyu Zhang
- The Shanghai Key Laboratory for Complex Prescription, The MOE Key Laboratory for Standardization of Chinese Medicines, and The SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Bin Lu
- The Shanghai Key Laboratory for Complex Prescription, The MOE Key Laboratory for Standardization of Chinese Medicines, and The SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Zengyang Yu
- The Shanghai Key Laboratory for Complex Prescription, The MOE Key Laboratory for Standardization of Chinese Medicines, and The SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Xiyu Mei
- The Shanghai Key Laboratory for Complex Prescription, The MOE Key Laboratory for Standardization of Chinese Medicines, and The SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Palida Abulizi
- College of Pharmacy, Xinjiang Medical University, Urumqi 830011, China
| | - Lili Ji
- The Shanghai Key Laboratory for Complex Prescription, The MOE Key Laboratory for Standardization of Chinese Medicines, and The SATCM Key Laboratory for New Resources and Quality Evaluation of Chinese Medicines, Institute of Chinese Materia Medica, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China.
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Kim JM, Hong KS, Song WK, Bae D, Hwang IK, Kim JS, Chung HM. Perivascular Progenitor Cells Derived From Human Embryonic Stem Cells Exhibit Functional Characteristics of Pericytes and Improve the Retinal Vasculature in a Rodent Model of Diabetic Retinopathy. Stem Cells Transl Med 2016; 5:1268-76. [PMID: 27388242 DOI: 10.5966/sctm.2015-0342] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Accepted: 03/30/2016] [Indexed: 12/13/2022] Open
Abstract
UNLABELLED : Diabetic retinopathy (DR) is the leading cause of blindness in working-age people. Pericyte loss is one of the pathologic cellular events in DR, which weakens the retinal microvessels. Damage to the microvascular networks is irreversible and permanent; thus further progression of DR is inevitable. In this study, we hypothesize that multipotent perivascular progenitor cells derived from human embryonic stem cells (hESC-PVPCs) improve the damaged retinal vasculature in the streptozotocin-induced diabetic rodent models. We describe a highly efficient and feasible protocol to derive such cells with a natural selection method without cell-sorting processes. As a cellular model of pericytes, hESC-PVPCs exhibited marker expressions such as CD140B, CD146, NG2, and functional characteristics of pericytes. Following a single intravitreal injection into diabetic Brown Norway rats, we demonstrate that the cells localized alongside typical perivascular regions of the retinal vasculature and stabilized the blood-retinal barrier breakdown. Findings in this study highlight a therapeutic potential of hESC-PVPCs in DR by mimicking the role of pericytes in vascular stabilization. SIGNIFICANCE This study provides a simple and feasible method to generate perivascular progenitor cells from human embryonic stem cells. These cells share functional characteristics with pericytes, which are irreversibly lost at the onset of diabetic retinopathy. Animal studies demonstrated that replenishing the damaged pericytes with perivascular progenitor cells could restore retinal vascular integrity and prevent fluid leakage. This provides promising and compelling evidence that perivascular progenitor cells can be used as a novel therapeutic agent to treat diabetic retinopathy patients.
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Affiliation(s)
- Jung Mo Kim
- Department of Tissue Morphogenesis, Max-Planck Institute for Molecular Biomedicine, Münster, Germany
| | - Ki-Sung Hong
- Stem Cell Research Lab, Department of Stem Cell Biology, School of Medicine, Konkuk University, Seoul, Republic of Korea
| | - Won Kyung Song
- Department of Ophthalmology, CHA Bundang Medical Center, CHA University, Seongnam, Republic of Korea
| | - Daekyeong Bae
- Stem Cell Research Lab, Department of Stem Cell Biology, School of Medicine, Konkuk University, Seoul, Republic of Korea
| | - In-Kyu Hwang
- Stem Cell Research Lab, Department of Stem Cell Biology, School of Medicine, Konkuk University, Seoul, Republic of Korea
| | - Jong Soo Kim
- Stem Cell Research Lab, Department of Stem Cell Biology, School of Medicine, Konkuk University, Seoul, Republic of Korea
| | - Hyung-Min Chung
- Stem Cell Research Lab, Department of Stem Cell Biology, School of Medicine, Konkuk University, Seoul, Republic of Korea
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Dalkara T, Alarcon-Martinez L. Cerebral microvascular pericytes and neurogliovascular signaling in health and disease. Brain Res 2015; 1623:3-17. [DOI: 10.1016/j.brainres.2015.03.047] [Citation(s) in RCA: 98] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Revised: 03/10/2015] [Accepted: 03/27/2015] [Indexed: 02/07/2023]
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Durham JT, Dulmovits BM, Cronk SM, Sheets AR, Herman IM. Pericyte chemomechanics and the angiogenic switch: insights into the pathogenesis of proliferative diabetic retinopathy? Invest Ophthalmol Vis Sci 2015; 56:3441-59. [PMID: 26030100 DOI: 10.1167/iovs.14-13945] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
PURPOSE To establish the regulatory roles that pericytes have in coordinating retinal endothelial cell (EC) growth and angiogenic potential. METHODS Pericytes were derived from donor diabetic (DHuRP) or normal (NHuRP) human retinae, and characterized using vascular markers, coculture, contraction, morphogenesis, and proliferation assays. To investigate capillary "cross-talk," pericyte-endothelial coculture growth, and connexin-43 (Cx43) expression assays were performed. Paracrine effects were examined via treating EC with pericyte-derived conditioned media (CM) in proliferation, angiogenesis, and angiocrine assays. The effects of sphingosine 1-phosphate (S1P) were assessed using receptor antagonists. RESULTS The DHuRP exhibit unique proliferative and morphologic properties, reflecting distinctive cytoskeletal and isoactin expression patterns. Unlike NHuRP, DHuRP are unable to sustain EC growth arrest in coculture and display reduced Cx43 expression. Further, CM from DHuRP (DPCM) markedly stimulates EC proliferation and tube formation. Treatment with S1P receptor antagonists mitigates DPCM growth-promotion in EC and S1P-mediated pericyte contraction. Angiocrine assays on normal and diabetic pericyte secretomes reveal factors involved in angiogenic control, inflammation, and metabolism. CONCLUSIONS Effects from the diabetic microenvironment appear sustainable in cell culture: pericytes derived from diabetic donor eyes seemingly possess a "metabolic memory" in vitro, which may be linked to original donor health status. Diabetes- and pericyte-dependent effects on EC growth and angiogenesis may reflect alterations in bioactive lipid, angiocrine, and chemomechanical signaling. Altogether, our results suggest that diabetes alters pericyte contractile phenotype and cytoskeletal signaling, which ultimately may serve as a key, initiating event required for retinal endothelial reproliferation, angiogenic activation, and the pathological neovascularization accompanying proliferative diabetic retinopathy.
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Ikawa M, Karita K. Relation between blood flow and tissue blood oxygenation in human fingertip skin. Microvasc Res 2015; 101:135-42. [PMID: 26235527 DOI: 10.1016/j.mvr.2015.07.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Revised: 07/29/2015] [Accepted: 07/29/2015] [Indexed: 11/15/2022]
Abstract
BACKGROUND Tissue blood flow (BF) is thought to be involved in the regulation of tissue blood oxygenation (StO2). The purpose of the present study was to show the relation between BF and StO2 by measuring them simultaneously under different conditions. METHODS Twenty-one healthy subjects (age 21-30years) participated in this study. We measured BF and StO2 in a small area of skin (fingertip, palm, forearm) simultaneously using a laser Doppler flowmeter and a tissue oxygenation monitor. Three measurements were made at rest while performing mental arithmetic and during constriction of the ipsilateral upper arm. RESULTS At rest, BF and StO2 were higher in the fingertip than in the palm or forearm (p<0.01). Performing mental arithmetic produced significant decreases in BF, oxygenated hemoglobin, and StO2 in the fingertip (p<0.05). Constriction of the ipsilateral upper arm produced significant decreases in BF and StO2 (p<0.05) and an increase in oxygenated hemoglobin (p<0.05). Both procedures produced significant increases in deoxygenated hemoglobin (p<0.05), which was in antiphase to the decrease in StO2. CONCLUSIONS BF decrease produced a significantly decreased StO2 in fingertip skin. The results show that simultaneous measurement of BF and StO2 is beneficial for showing the close relation between them.
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Affiliation(s)
- Motohide Ikawa
- Division of Periodontology and Endodontology, Department of Oral Biology, Tohoku University Graduate School of Dentistry, 4-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan.
| | - Keishiro Karita
- Division of Oral Diagnosis, Department of Oral Health and Development Sciences, Tohoku University Graduate School of Dentistry, 4-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan
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Yu Z, Lu B, Sheng Y, Zhou L, Ji L, Wang Z. Andrographolide ameliorates diabetic retinopathy by inhibiting retinal angiogenesis and inflammation. Biochim Biophys Acta Gen Subj 2015; 1850:824-31. [DOI: 10.1016/j.bbagen.2015.01.014] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Revised: 01/12/2015] [Accepted: 01/20/2015] [Indexed: 11/28/2022]
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Finasteride reduces microvessel density and expression of vascular endothelial growth factor in renal tissue of diabetic rats. Am J Med Sci 2015; 349:516-20. [PMID: 25789687 DOI: 10.1097/maj.0000000000000451] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND Vascular endothelial growth factor (VEGF) plays a critical role in the pathogenesis of diabetic microvascular complications. Finasteride has been confirmed to decrease VEGF expression in prostate and prostatic suburethral tissue resulting in limiting hematuria from human benign prostatic hyperplasia. The purpose of this study was to evaluate the effects of finasteride on microvessel density (MVD), VEGF protein and mRNA expressions in the renal tissue of diabetic rats. METHODS Diabetic rats induced by streptozotocin were intragastrically given finasteride at 30 mg/kg body weight once a day for 4 weeks. Histomorphologic changes in kidney were observed under light microscope. Immunohistochemistry for CD34 and VEGF on kidney sections was performed to assess MVD and VEGF protein expression in glomeruli of rats, respectively. The VEGF mRNA expression in the renal tissue was examined using reverse transcription polymerase chain reaction analysis. RESULTS The glomerular tuft area, glomerular volume, MVD, VEGF protein expression in glomeruli and VEGF mRNA expression in the renal cortex tissue were significantly increased in diabetic rats and finasteride-treated rats when compared with controls (P < 0.01, P < 0.05). When compared with diabetic rats, the glomerular tuft area, glomerular volume, MVD, VEGF protein expression in glomeruli and VEGF mRNA expression in the renal cortex tissue of finasteride-treated rats were significantly decreased (P < 0.05, P < 0.01). CONCLUSIONS Finasteride reduces the VEGF expression and decreases the MVD in the renal tissue of diabetic rats, suggesting the therapeutic potential of finasteride on diabetic microvascular complications.
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Gao W, Ferguson G, Connell P, Walshe T, O'Brien C, Redmond EM, Cahill PA. Glucose attenuates hypoxia-induced changes in endothelial cell growth by inhibiting HIF-1α expression. Diab Vasc Dis Res 2014; 11:270-280. [PMID: 24853909 DOI: 10.1177/1479164114533356] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Hyperglycaemia and hypoxia play essential pathophysiological roles in diabetes. We determined whether hyperglycaemia influences endothelial cell growth under hypoxic conditions in vitro. Using a Ruskinn Invivo2 400 Hypoxia Workstation, bovine aortic endothelial cells (BAEC) were exposed to high glucose concentrations (25 mM glucose) under normoxic or hypoxic conditions before cell growth (balance of proliferation and apoptosis) was assessed by fluorescence-activated cell sorting (FACS) analysis, proliferating cell nuclear antigen (pCNA), Bcl-xL and caspase-3 protein expression and activity. Hypoxia increased hypoxia response element (HRE) transactivation and induced hypoxia-inducible factor-1α (HIF-1α) expression when compared to normoxic controls concomitant with a significant decrease in cell growth. High glucose (25 mM) concentrations attenuated HRE transactivation and HIF-1α protein expression while concurrently reducing hypoxia-induced changes in BAEC growth. Knockdown of HIF-1α expression significantly decreased hypoxia-induced changes in growth and attenuated the modulatory effects of glucose. These results provide evidence that hypoxia-induced control of BAEC growth can be altered by the presence of glucose via inhibition of HIF-1α expression and activation.
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Affiliation(s)
- Wei Gao
- Vascular Biology and Therapeutics Laboratory, School of Biotechnology, Faculty of Science and Health, Dublin City University, Dublin, Ireland
| | - Gail Ferguson
- Vascular Biology and Therapeutics Laboratory, School of Biotechnology, Faculty of Science and Health, Dublin City University, Dublin, Ireland
| | - Paul Connell
- Vascular Biology and Therapeutics Laboratory, School of Biotechnology, Faculty of Science and Health, Dublin City University, Dublin, Ireland Mater Misericordiae Hospital, Institute of Ophthalmology, The Conway Institute of Biomolecular and Biomedical Research, Dublin, Ireland
| | - Tony Walshe
- Vascular Biology and Therapeutics Laboratory, School of Biotechnology, Faculty of Science and Health, Dublin City University, Dublin, Ireland
| | - Colm O'Brien
- Mater Misericordiae Hospital, Institute of Ophthalmology, The Conway Institute of Biomolecular and Biomedical Research, Dublin, Ireland
| | - Eileen M Redmond
- Department of Surgery, University of Rochester, Rochester, NY, USA
| | - Paul A Cahill
- Vascular Biology and Therapeutics Laboratory, School of Biotechnology, Faculty of Science and Health, Dublin City University, Dublin, Ireland
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Al-Shabrawey M, Elsherbiny M, Nussbaum J, Othman A, Megyerdi S, Tawfik A. Targeting Neovascularization in Ischemic Retinopathy: Recent Advances. EXPERT REVIEW OF OPHTHALMOLOGY 2014; 8:267-286. [PMID: 25598837 DOI: 10.1586/eop.13.17] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Pathological retinal neovascularization (RNV) is a common micro-vascular complication in several retinal diseases including retinopathy of prematurity, diabetic retinopathy, age-related macular degeneration and central vein occlusion. The current therapeutic modalities of RNV are invasive and although they may slow or halt the progression of the disease they are unlikely to restore normal acuity. Therefore, there is an urgent need to develop treatment modalities, which are less invasive and therefore associated with fewer procedural complications and systemic side effects. This review article summarizes our understanding of the pathophysiology and current treatment of RNV in ischemic retinopathies; lists potential therapeutic targets; and provides a framework for the development of future treatment modalities.
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Affiliation(s)
- Mohamed Al-Shabrawey
- Oral Biology/Anatomy, College of Dental Medicine, GeorgiaRegentsUniversity (GRU), Augusta GA, USA ; Ophthalmology and Vision Discovery Institute, Medical College of Georgia, GRU ; Anatomy, Mansoura Faculty of Medicine, Mansoura University-Egypt ; Vascular Biology Center, Medical College of Georgia, GRU
| | - Mohamed Elsherbiny
- Oral Biology/Anatomy, College of Dental Medicine, GeorgiaRegentsUniversity (GRU), Augusta GA, USA ; Ophthalmology and Vision Discovery Institute, Medical College of Georgia, GRU ; Anatomy, Mansoura Faculty of Medicine, Mansoura University-Egypt
| | - Julian Nussbaum
- Ophthalmology and Vision Discovery Institute, Medical College of Georgia, GRU
| | - Amira Othman
- Anatomy, Mansoura Faculty of Medicine, Mansoura University-Egypt
| | - Sylvia Megyerdi
- Oral Biology/Anatomy, College of Dental Medicine, GeorgiaRegentsUniversity (GRU), Augusta GA, USA
| | - Amany Tawfik
- Ophthalmology and Vision Discovery Institute, Medical College of Georgia, GRU ; Cellular Biology and Anatomy, Medical College of Georgia, GRU
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Lu B, Bai Y, Du Z, Chen S, Deligema D, Pang Z. The effect of Chinese medicine Pu-Ren-Dan on pancreatic angiogenesis in high fat diet/streptozotocin-induced diabetic rats. Indian J Pharmacol 2013; 45:556-62. [PMID: 24347761 PMCID: PMC3847243 DOI: 10.4103/0253-7613.121364] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/31/2012] [Revised: 04/08/2013] [Accepted: 09/12/2013] [Indexed: 12/13/2022] Open
Abstract
Objectives: The islet vascular system is critical for β-cell function. This study investigated the antidiabetic effect of the Chinese Pu-Ren-Dan (PRD) recipe by regulating the pancreatic angiogenic factors in T2DM rats. Materials Methods: High fat diet/streptozotocin-induced obese type-2 diabetes mellitus rats were developed and treated with PRD for 4 weeks. Then glucolipid metabolism, insulin secretion, pancreatic blood flow, ultrastructure of islet β-cell, histological changes of islet and protein expressions of pancreatic angiogenic factors were investigated. Results: PRD-reduced T2DM rats’ body weight and blood glucose level resisted the lipid metabolism disturbance, and ameliorated the insulin resistance and β-cell function. In addition, the histological and morphological studies proved that PRD could maintain the normal distribution of endocrine cell in islet and normal ultrastructure of β cell. An increased pancreatic blood flow was observed after the PRD treatment. In the investigation of pancreatic angiogenic factors, PRD inhibited the decreased expression of VEGF and Ang-1, and reversed the reduction of VEGFR2 and Tie2 phosphorylation in T2DM rats; the Ang-2 and TGFβ expression were up-regulated by PRD while PKC was activated; endostatin and angiostatin were down-regulated by PRD. Conclusions: The results suggest that increasing VEGF expression, regulating VEGF/VEGFR2 signaling, stimulating Ang-1/Tie-2 signaling pathway, and inhibiting PKC-TGFβ signaling and antiangiogenic factors might be the underlying mechanism of PRD's antidiabetic effect.
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Affiliation(s)
- Binan Lu
- Institute of Chinese Minority Traditional Medicine, Minzu University of China, Beijing 100081, P. R. China
| | - Yongfei Bai
- Institute of Chinese Minority Traditional Medicine, Minzu University of China, Beijing 100081, P. R. China
| | - Ziliang Du
- Institute of Chinese Minority Traditional Medicine, Minzu University of China, Beijing 100081, P. R. China
| | - Shu Chen
- Institute of Chinese Minority Traditional Medicine, Minzu University of China, Beijing 100081, P. R. China
| | - D Deligema
- Institute of Chinese Minority Traditional Medicine, Minzu University of China, Beijing 100081, P. R. China
| | - Zongran Pang
- Institute of Chinese Minority Traditional Medicine, Minzu University of China, Beijing 100081, P. R. China
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Aldebasi YH, Aly SM, Rahmani AH. Therapeutic implications of curcumin in the prevention of diabetic retinopathy via modulation of anti-oxidant activity and genetic pathways. INTERNATIONAL JOURNAL OF PHYSIOLOGY, PATHOPHYSIOLOGY AND PHARMACOLOGY 2013; 5:194-202. [PMID: 24379904 PMCID: PMC3867697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Accepted: 11/21/2013] [Indexed: 06/03/2023]
Abstract
Diabetic Retinopathy (DR) is one of the most common complications of diabetes mellitus that affects the blood vessels of the retina, leading to blindness. The current approach of treatment based on anti-inflammatory, anti-angiogenesis drugs and laser photocoagulation are effective but also shows adverse affect in retinal tissues and that can even worsen the visual abilities. Thus, a safe and effective mode of treatment is needed to control or delaying the DR. Based on the earlier evidence of the potentiality of natural products as anti-oxidants, anti-diabetic and antitumor, medicinal plants may constitute a good therapeutic approach in the prevention of DR. Curcumin, constituents of dietary spice turmeric, has been observed to have therapeutic potential in the inhibition or slow down progression of DR. In this review, we summarize the therapeutic potentiality of curcumin in the delaying the DR through antioxidant, anti-inflammatory, inhibition of Vascular Endothelial Growth and nuclear transcription factors. The strength of involvement of curcumin in the modulation of genes action creates a strong optimism towards novel therapeutic strategy of diabetic retinopathy and important mainstay in the management of diabetes and its complications DR.
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Affiliation(s)
- Yousef H Aldebasi
- Department of Optometry, College of Applied Medical Sciences, Qassim UniversitySaudi Arabia
| | - Salah M Aly
- Department of Medical Laboratories, College of Applied Medical Sciences, Qassim UniversitySaudi Arabia
- Department of Pathology, Faculty of Vet. Medicine, Suez Canal UniversityIsmailia, Egypt
| | - Arshad H Rahmani
- Department of Medical Laboratories, College of Applied Medical Sciences, Qassim UniversitySaudi Arabia
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Kang MK, Lim SS, Lee JY, Yeo KM, Kang YH. Anthocyanin-rich purple corn extract inhibit diabetes-associated glomerular angiogenesis. PLoS One 2013; 8:e79823. [PMID: 24278186 PMCID: PMC3835931 DOI: 10.1371/journal.pone.0079823] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Accepted: 10/04/2013] [Indexed: 01/05/2023] Open
Abstract
Diabetic nephropathy (DN) is one of the major diabetic complications and the leading cause of end-stage renal disease. Abnormal angiogenesis results in new vessels that are often immature and play a pathological role in DN, contributing to renal fibrosis and disrupting glomerular failure. Purple corn has been utilized as a daily food and exerts disease-preventive activities. This study was designed to investigate whether anthocyanin-rich purple corn extract (PCE) prevented glomerular angiogenesis under hyperglycemic conditions. Human endothelial cells were cultured in conditioned media of mesangial cells exposed to 33 mM high glucose (HG-HRMC-CM). PCE decreased endothelial expression of vascular endothelial growth factor (VEGF) and hypoxia inducible factor (HIF)-1α induced by HG-HRMC-CM. Additionally, PCE attenuated the induction of the endothelial marker of platelet endothelial cell adhesion molecule (PECAM)-1 and integrin β3 enhanced in HG-HRMC-CM. Endothelial tube formation promoted by HG-HRMC-CM was disrupted in the presence of PCE. In the in vivo study employing db/db mice treated with 10 mg/kg PCE for 8 weeks, PCE alleviated glomerular angiogenesis of diabetic kidneys by attenuating the induction of VEGF and HIF-1α. Oral administration of PCE retarded the endothelial proliferation in db/db mouse kidneys, evidenced by its inhibition of the induction of vascular endothelium-cadherin, PECAM-1 and Ki-67. PCE diminished the mesangial and endothelial induction of angiopoietin (Angpt) proteins under hypeglycemic conditions. The induction and activation of VEGF receptor 2 (VEGFR2) were dampened by treating PCE to db/db mice. These results demonstrate that PCE antagonized glomerular angiogenesis due to chronic hyperglycemia and diabetes through disturbing the Angpt-Tie-2 ligand-receptor system linked to renal VEGFR2 signaling pathway. Therefore, PCE may be a potent therapeutic agent targeting abnormal angiogenesis in DN leading to kidney failure.
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Affiliation(s)
- Min-Kyung Kang
- Department of Food and Nutrition and Center for Aging and Healthcare, Hallym University, Chuncheon, Korea
| | - Soon Sung Lim
- Department of Food and Nutrition and Center for Aging and Healthcare, Hallym University, Chuncheon, Korea
| | - Jae-Yong Lee
- Department of Biochemistry, School of Medicine, Hallym University, Chuncheon, Korea
| | | | - Young-Hee Kang
- Department of Food and Nutrition and Center for Aging and Healthcare, Hallym University, Chuncheon, Korea
- * E-mail:
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Abstract
Background Emerging evidence suggests that angiogenic and pro-inflammatory cytokine leptin might be implicated in ocular neovascularization. However, the potential of inhibiting leptin function in ophthalmic cells has never been explored. Here we assessed mitogenic, angiogenic, and signaling leptin activities in retinal and corneal endothelial cells and examined the capability of a specific leptin receptor (ObR) antagonist, Allo-aca, to inhibit these functions. Methods and Results The experiments were carried out in monkey retinal (RF/6A) and bovine corneal (BCE) endothelial cells. Leptin at 50-250 ng/mL stimulated the growth of both cell lines in a dose-dependent manner. The maximal mitogenic response (35±7 and 27±3% in RF6A and BCE cells, respectively) was noted at 24 h of 250 ng/mL leptin treatments. Leptin-dependent proliferation was reduced to base levels with 10 and 100 nM Allo-aca in BCE and RF6A cells, respectively. In both cell lines, leptin promoted angiogenic responses, with the maximal increase in tube formation (163±10 and 133±8% in RF6A and BCE cultures, respectively) observed under a 250 ng/mL leptin treatment for 3 h. Furthermore, in both cell lines 250 ng/mL leptin modulated the activity or expression of several signaling molecules involved in proliferation, inflammatory activity and angiogenesis, such as STAT3, Akt, and ERK1/2, COX2, and NFκB. In both cell lines, leptin-induced angiogenic and signaling responses were significantly inhibited with 100 nM Allo-aca. We also found that leptin increased its own mRNA and protein expression in both cell lines, and this autocrine effect was abolished by 100-250 nM Allo-aca. Conclusions Our data provide new insights into the role of leptin in ocular endothelial cells and represent the first original report on targeting ObR in ophthalmic cell models.
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Alves MG, Martins AD, Cavaco JE, Socorro S, Oliveira PF. Diabetes, insulin-mediated glucose metabolism and Sertoli/blood-testis barrier function. Tissue Barriers 2013; 1:e23992. [PMID: 24665384 PMCID: PMC3875609 DOI: 10.4161/tisb.23992] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Revised: 02/10/2013] [Accepted: 02/12/2013] [Indexed: 02/06/2023] Open
Abstract
Blood testis barrier (BTB) is one of the tightest blood-barriers controlling the entry of substances into the intratubular fluid. Diabetes Mellitus (DM) is an epidemic metabolic disease concurrent with falling fertility rates, which provokes severe detrimental BTB alterations. It induces testicular alterations, disrupting the metabolic cooperation between the cellular constituents of BTB, with dramatic consequences on sperm quality and fertility. As Sertoli cells are involved in the regulation of spermatogenesis, providing nutritional support for germ cells, any metabolic alteration in these cells derived from DM may be responsible for spermatogenesis disruption, playing a crucial role in fertility/subfertility associated with this pathology. These cells have a glucose sensing machinery that reacts to hormonal fluctuations and several mechanisms to counteract hyper/hypoglycemic events. The role of DM on Sertoli/BTB glucose metabolism dynamics and the metabolic molecular mechanisms through which DM and insulin deregulation alter its functioning, affecting male reproductive potential will be discussed.
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Affiliation(s)
- Marco G. Alves
- CICS-UBI; Health Sciences Research Centre; University of Beira Interior; Covilhã, Portugal
| | - Ana D. Martins
- CICS-UBI; Health Sciences Research Centre; University of Beira Interior; Covilhã, Portugal
| | - José E. Cavaco
- CICS-UBI; Health Sciences Research Centre; University of Beira Interior; Covilhã, Portugal
| | - Sílvia Socorro
- CICS-UBI; Health Sciences Research Centre; University of Beira Interior; Covilhã, Portugal
| | - Pedro F. Oliveira
- CICS-UBI; Health Sciences Research Centre; University of Beira Interior; Covilhã, Portugal
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Wang LL, Sun Y, Huang K, Zheng L. Curcumin, a potential therapeutic candidate for retinal diseases. Mol Nutr Food Res 2013; 57:1557-68. [DOI: 10.1002/mnfr.201200718] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Revised: 12/15/2012] [Accepted: 12/17/2012] [Indexed: 01/27/2023]
Affiliation(s)
- Lei-Lei Wang
- College of Life Sciences; Wuhan University; Wuhan; P. R. China
| | - Yue Sun
- College of Life Sciences; Wuhan University; Wuhan; P. R. China
| | | | - Ling Zheng
- College of Life Sciences; Wuhan University; Wuhan; P. R. China
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Busik JV, Esselman WJ, Reid GE. Examining the role of lipid mediators in diabetic retinopathy. ACTA ACUST UNITED AC 2012; 7:661-675. [PMID: 23646066 DOI: 10.2217/clp.12.68] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Diabetic retinopathy is the most disabling complication of diabetes, affecting 65% of patients after 10 years of the disease. Current treatment options for diabetic retinopathy are highly invasive and fall short of complete amelioration of the disease. Understanding the pathogenesis of diabetic retinopathy is critical to the development of more effective treatment options. Diabetic hyperglycemia and dyslipidemia are the main metabolic insults that affect retinal degeneration in diabetes. Although the role of hyperglycemia in inducing diabetic retinopathy has been studied in detail, much less attention has been paid to dyslipidemia. Recent clinical studies have demonstrated a strong association between dyslipidemia and development of diabetic retinopathy, highlighting the importance of understanding the exact changes in retinal lipid metabolism in diabetes. This review describes what is known on the role of dyslipidemia in the development of diabetic retinopathy, with a focus on retinal-specific lipid metabolism and its dysregulation in diabetes.
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Affiliation(s)
- Julia V Busik
- Department of Physiology, Michigan State University, East Lansing, MI, USA
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Yi CX, Gericke M, Krüger M, Alkemade A, Kabra DG, Hanske S, Filosa J, Pfluger P, Bingham N, Woods SC, Herman J, Kalsbeek A, Baumann M, Lang R, Stern JE, Bechmann I, Tschöp MH. High calorie diet triggers hypothalamic angiopathy. Mol Metab 2012; 1:95-100. [PMID: 24024123 DOI: 10.1016/j.molmet.2012.08.004] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2012] [Revised: 08/02/2012] [Accepted: 08/02/2012] [Indexed: 01/15/2023] Open
Abstract
Obesity, type 2 diabetes, and related diseases represent major health threats to modern society. Related pathophysiology of impaired neuronal function in hypothalamic control centers regulating metabolism and body weight has been dissected extensively and recent studies have started focusing on potential roles of astrocytes and microglia. The hypothalamic vascular system, however, which maintains the microenvironment necessary for appropriate neuronal function, has been largely understudied. We recently discovered that high fat/high sucrose diet exposure leads to increased hypothalamic presence of immunoglobulin G (IgG1). Investigating this phenomenon further, we have discovered a significant increase in blood vessel length and density in the arcuate nucleus (ARC) of the hypothalamus in mice fed a high fat/high sucrose diet, compared to matched controls fed standard chow diet. We also found a clearly increased presence of α-smooth muscle actin immunoreactive vessels, which are rarely present in the ARC and indicate an increase in the formation of new arterial vessels. Along the blood brain barrier, an increase of degenerated endothelial cells are observed. Moreover, such hypothalamic angiogenesis was not limited to rodent models. We also found an increase in the number of arterioles of the infundibular nucleus (the human equivalent of the mouse ARC) in patients with type 2 diabetes, suggesting angiogenesis occurs in the human hypothalamus of diabetics. Our discovery reveals novel hypothalamic pathophysiology, which is reminiscent of diabetic retinopathy and suggests a potential functional involvement of the hypothalamic vasculature in the later stage pathogenesis of metabolic syndrome.
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Affiliation(s)
- Chun-Xia Yi
- Institute for Diabetes and Obesity, Helmholtz Centre for Health and Environment & Technical University Munich, Munich, Germany
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Role of matrix metalloproteinase-2 and -9 in the development of diabetic retinopathy. J Ocul Biol Dis Infor 2012; 5:1-8. [PMID: 23833698 DOI: 10.1007/s12177-012-9091-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Accepted: 06/07/2012] [Indexed: 12/11/2022] Open
Abstract
Diabetic retinopathy represents the most common causes of vision loss in patients affected by diabetes mellitus. The cause of vision loss in diabetic retinopathy is complex and remains incompletely understood. One of the earliest changes in the development of retinopathy is the accelerated apoptosis of retinal microvascular cells and the formation of acellular capillaries by unknown mechanism. Results of a recent research suggest an important role of matrix metalloproteinases (MMPs) in the development of diabetic retinopathy. MMPs are a large family of proteinases that remodel extracellular matrix components, and under pathological condition, its induction is considered as a negative regulator of cell survival; and in diabetes, latent MMPs are activated in the retina and its capillary cells, and activation of MMP-2 and -9 induces apoptosis of retinal capillary cells. This review will focus on the MMP-2 and MMP-9 in the diabetic retina with special reference to oxidative stress, mitochondria dysfunction, inflammation and angiogenesis, as well as summarizing the current information linking these proteins to pathogenesis of diabetic retinopathy.
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