1
|
Zagst AJ, Smith JD, Wang R, Harrison WW. Foveal avascular zone size and mfERG metrics in diabetes and prediabetes: a pilot study of the relationship between structure and function. Doc Ophthalmol 2023; 147:99-107. [PMID: 37495830 DOI: 10.1007/s10633-023-09943-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 07/03/2023] [Indexed: 07/28/2023]
Abstract
PURPOSE Previous studies have demonstrated functional and structural retinal changes in type 2 diabetes (T2DM). However, less is understood in prediabetes, which is an important precursor to T2DM. Here, we evaluate the microvasculature structure of the foveal avascular zone (FAZ) and how it is correlated with retinal function as measured by the multifocal electroretinogram (mfERG) across levels of glucose dysfunction to uncover how T2DM and prediabetes alter this structure-function relationship. METHODS 33 subjects were included: 9 controls, 12 prediabetes, 12 T2DM with no retinopathy or edema. Subjects were aged 30-70 years, had BCVA of 20/25 or better, and had no confounding ocular conditions. Blood was collected via fingerstick to determine Hemoglobin A1c (HbA1c), which was used along with previous diagnosis, to determine study grouping. Optical coherence tomography angiography (OCTA) was used to analyze the FAZ area and was corrected for refractive error. FAZ area was measured by hand using the Heidelberg Spectralis software. mfERG (VERIS 6.3) metrics implicit time (IT) and amplitude were evaluated in the foveal region, macular region, and averaged over the posterior pole of the right eye. Regression analysis was performed between each study group parameter to determine relationships, and t tests with corrections were used to compare groups. RESULTS FAZ area (superficial plexus) was negatively correlated with mfERG posterior pole amplitude (p < 0.01, R2 = 0.30), foveal amp (p = 0.02 R2 = 0.17) and macular amplitude (p = 0.02 R2 = 0.18) across all 33 study subjects. FAZ and mfERG metrics were not significantly different between study groups in this cohort except for IT, which was more delayed in the diabetes group compared to other groups. CONCLUSION FAZ area is correlated with mfERG amplitudes but not IT. This suggests a link between the structural metrics and retinal function. Longitudinal follow-up work would be helpful to determine the timing of these changes in prediabetes.
Collapse
Affiliation(s)
- Allison Jussel Zagst
- Department of Clinical Sciences, University of Houston College of Optometry, 4401 Martin Luther King Blvd, Houston, TX, 77204-2020, USA
| | - Jennyffer D Smith
- Department of Clinical Sciences, University of Houston College of Optometry, 4401 Martin Luther King Blvd, Houston, TX, 77204-2020, USA
| | - Rachel Wang
- Department of Clinical Sciences, University of Houston College of Optometry, 4401 Martin Luther King Blvd, Houston, TX, 77204-2020, USA
| | - Wendy W Harrison
- Department of Clinical Sciences, University of Houston College of Optometry, 4401 Martin Luther King Blvd, Houston, TX, 77204-2020, USA.
| |
Collapse
|
2
|
Rong R, Zhou X, Liang G, Li H, You M, Liang Z, Zeng Z, Xiao H, Ji D, Xia X. Targeting Cell Membranes, Depleting ROS by Dithiane and Thioketal-Containing Polymers with Pendant Cholesterols Delivering Necrostatin-1 for Glaucoma Treatment. ACS NANO 2022; 16:21225-21239. [PMID: 36487191 DOI: 10.1021/acsnano.2c09202] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Glaucoma is the leading cause of irreversible blindness worldwide, characterized by progressive vision loss due to the selective damage to retinal ganglion cells (RGCs) and their axons. Oxidative stress is generally believed as one key factor of RGCs death. Recently, necroptosis was identified to play a key role in glaucomatous injury. Therefore, depletion of reactive oxygen species (ROS) and inhibition of necroptosis in RGCs has become one of treatment strategies for glaucoma. However, existing drugs without efficient drug enter into the retina and have controlled release due to a short drug retention. Herein, we designed a glaucomatous microenvironment-responsive drug carrier polymer, which is characterized by the presence of thioketal bonds and 1,4-dithiane unit in the main chain for depleting ROS as well as the pendant cholesterols for targeting cell membranes. This polymer was adopted to encapsulate an inhibitor of necroptosis, necrostatin-1, into nanoparticles (designated as NP1). NP1 with superior biosafety could scavenge ROS in RGCs both in vitro and in vivo of an acute pathological glaucomatous injury model. Further, NP1 was found to effectively inhibit the upregulation of the necroptosis pathway, reducing the death of RGCs. The findings in this study exemplified the use of nanomaterials as potential strategies to treat glaucoma.
Collapse
Affiliation(s)
- Rong Rong
- Eye Center of Xiangya Hospital, Central South University, Changsha, Hunan410008, P. R. China
- Hunan Key Laboratory of Ophthalmology, Changsha, Hunan410008, P. R. China
- National Clinical Research Center for Geriatric Diseases (Xiangya Hospital), Central South University, Changsha, Hunan410008, P. R. China
| | - Xuezhi Zhou
- Eye Center of Xiangya Hospital, Central South University, Changsha, Hunan410008, P. R. China
- Hunan Key Laboratory of Ophthalmology, Changsha, Hunan410008, P. R. China
- National Clinical Research Center for Geriatric Diseases (Xiangya Hospital), Central South University, Changsha, Hunan410008, P. R. China
| | - Ganghao Liang
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing100190, China
- University of Chinese Academy of Sciences, Beijing100049, China
| | - Haibo Li
- Eye Center of Xiangya Hospital, Central South University, Changsha, Hunan410008, P. R. China
- Hunan Key Laboratory of Ophthalmology, Changsha, Hunan410008, P. R. China
- National Clinical Research Center for Geriatric Diseases (Xiangya Hospital), Central South University, Changsha, Hunan410008, P. R. China
| | - Mengling You
- Eye Center of Xiangya Hospital, Central South University, Changsha, Hunan410008, P. R. China
- Hunan Key Laboratory of Ophthalmology, Changsha, Hunan410008, P. R. China
- National Clinical Research Center for Geriatric Diseases (Xiangya Hospital), Central South University, Changsha, Hunan410008, P. R. China
| | - Zhuotao Liang
- National Clinical Research Center for Geriatric Diseases (Xiangya Hospital), Central South University, Changsha, Hunan410008, P. R. China
- Department of Spine Surgery, Xiangya Hospital, Central South University, Changsha, Hunan410008, P. R. China
| | - Zhou Zeng
- Eye Center of Xiangya Hospital, Central South University, Changsha, Hunan410008, P. R. China
- Hunan Key Laboratory of Ophthalmology, Changsha, Hunan410008, P. R. China
- National Clinical Research Center for Geriatric Diseases (Xiangya Hospital), Central South University, Changsha, Hunan410008, P. R. China
| | - Haihua Xiao
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing100190, China
- University of Chinese Academy of Sciences, Beijing100049, China
| | - Dan Ji
- Eye Center of Xiangya Hospital, Central South University, Changsha, Hunan410008, P. R. China
- Hunan Key Laboratory of Ophthalmology, Changsha, Hunan410008, P. R. China
- National Clinical Research Center for Geriatric Diseases (Xiangya Hospital), Central South University, Changsha, Hunan410008, P. R. China
| | - Xiaobo Xia
- Eye Center of Xiangya Hospital, Central South University, Changsha, Hunan410008, P. R. China
- Hunan Key Laboratory of Ophthalmology, Changsha, Hunan410008, P. R. China
- National Clinical Research Center for Geriatric Diseases (Xiangya Hospital), Central South University, Changsha, Hunan410008, P. R. China
| |
Collapse
|
3
|
Jones MA, Jadeja RN, Flandrin O, Abdelrahman AA, Thounojam MC, Thomas S, Dai C, Xiao H, Chen JK, Smith SB, Bartoli M, Martin PM, Powell FL. Autonomous regulation of retinal insulin biosynthesis in diabetes. Neuropeptides 2022; 94:102258. [PMID: 35660758 PMCID: PMC10440820 DOI: 10.1016/j.npep.2022.102258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 05/08/2022] [Accepted: 05/15/2022] [Indexed: 10/18/2022]
Abstract
Diabetic retinopathy (DR) is a neurodegenerative disease that results as a complication of dysregulated glucose metabolism, or diabetes. The signaling of insulin is lost or dampened in diabetes, but this hormone has also been shown to be an important neurotrophic factor which supports neurons of the brain. The role of local insulin synthesis and secretion in the retina, however, is unclear. We have investigated whether changes in local insulin synthesis occur in the diabetic retina and in response to stressors known to initiate retinal neurodegenerative processes. The expression of insulin and its cleavage product, c-peptide, were examined in retinas of a Type I diabetes animal model and human postmortem donors with DR. We detected mRNAs for insulin I (Ins1), insulin II (Ins2) and human insulin (Ins) by quantitative real-time polymerase chain reaction (qRT-PCR) and in situ hybridization. Using an ex-vivo system, isolated neuroretinas and retinal pigmented epithelium (RPE) layers were exposed to glycemic, oxidative and inflammatory environments to measure insulin gene transcripts produced de novo in the retina under disease-relevant conditions. The expression of insulin in the retina was altered with the progression of diabetes in STZ mice and donors with DR. Transcription factors for insulin, were simultaneously expressed in a pattern matching insulin genes. Furthermore, de novo insulin mRNA in isolated retinas was induced by acute stress. RPE explants displayed the most pronounced changes in Ins1 and Ins2. This data reveals that the retina, like the brain, is an organ capable of producing local insulin and this synthesis is altered in diabetes.
Collapse
Affiliation(s)
- Malita A Jones
- Department of Biochemistry and Molecular Biology, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA
| | - Ravirajsinh N Jadeja
- Department of Biochemistry and Molecular Biology, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA
| | - Orneika Flandrin
- UC Berkeley School of Optometry, University of California, Berkeley, CA, USA
| | - Ammar A Abdelrahman
- Department of Pharmacology, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA; Department of Clinical Pharmacy, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | - Menaka C Thounojam
- Department of Ophthalmology, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA
| | - Shakera Thomas
- Department of Biochemistry and Molecular Biology, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA
| | - Caihong Dai
- Department of Cell Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA
| | - Haiyan Xiao
- Department of Cell Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA
| | - Jian-Kang Chen
- Department of Cell Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA
| | - Sylvia B Smith
- Department of Cell Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA
| | - Manuela Bartoli
- Department of Ophthalmology, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA
| | - Pamela M Martin
- Department of Biochemistry and Molecular Biology, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA; Department of Cell Biology and Anatomy, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA; Georgia Cancer Center, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA
| | - Folami L Powell
- Department of Biochemistry and Molecular Biology, Medical College of Georgia at Augusta University, Augusta, GA 30912, USA.
| |
Collapse
|
4
|
Teimouri M, Hosseini H, ArabSadeghabadi Z, Babaei-Khorzoughi R, Gorgani-Firuzjaee S, Meshkani R. The role of protein tyrosine phosphatase 1B (PTP1B) in the pathogenesis of type 2 diabetes mellitus and its complications. J Physiol Biochem 2022; 78:307-322. [PMID: 34988903 DOI: 10.1007/s13105-021-00860-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 11/16/2021] [Indexed: 01/16/2023]
Abstract
Insulin resistance, the most important characteristic of the type 2 diabetes mellitus (T2DM), is mostly caused by impairment in the insulin receptor (IR) signal transduction pathway. Protein tyrosine phosphatase 1B (PTP1B), one of the main negative regulators of the IR signaling pathway, is broadly expressed in various cells and tissues. PTP1B decreases the phosphorylation of the IR resulting in insulin resistance in various tissues. The evidence for the physiological role of PTP1B in regulation of metabolic pathways came from whole-body PTP1B-knockout mice. Whole-body and tissue-specific PTP1B-knockout mice showed improvement in adiposity, insulin resistance, and glucose tolerance. In addition, the key role of PTP1B in the pathogenesis of T2DM and its complications was further investigated in mice models of PTP1B deficient/overexpression. In recent years, targeting PTP1B using PTP1B inhibitors is being considered an attractive target to treat T2DM. PTP1B inhibitors improve the sensitivity of the insulin receptor and have the ability to cure insulin resistance-related diseases. We herein summarized the biological functions of PTP1B in different tissues in vivo and in vitro. We also describe the effectiveness of potent PTP1B inhibitors as pharmaceutical agents to treat T2DM.
Collapse
Affiliation(s)
- Maryam Teimouri
- Department of Clinical Biochemistry, School of Allied Medical Sciences, Shahroud University of Medical Sciences, Shahroud, Iran
| | - Hossein Hosseini
- Department of Clinical Biochemistry, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Zahra ArabSadeghabadi
- Department of Clinical Sciences, Faculty of Veterinary Science, Bu-Ali Sina University, Hamedan, Iran
| | - Reyhaneh Babaei-Khorzoughi
- Department of Clinical Biochemistry, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Sattar Gorgani-Firuzjaee
- Department of Medical Laboratory Sciences, School of Allied Health Medicine, AJA University of Medical Sciences, Tehran, Iran
| | - Reza Meshkani
- Department of Clinical Biochemistry, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
| |
Collapse
|
5
|
Dierschke SK, Dennis MD. Retinal Protein O-GlcNAcylation and the Ocular Renin-angiotensin System: Signaling Cross-roads in Diabetic Retinopathy. Curr Diabetes Rev 2022; 18:e011121190177. [PMID: 33430751 PMCID: PMC8272735 DOI: 10.2174/1573399817999210111205933] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 11/14/2020] [Accepted: 11/16/2020] [Indexed: 01/23/2023]
Abstract
It is well established that diabetes and its associated hyperglycemia negatively impact retinal function, yet we know little about the role played by augmented flux through the Hexosamine Biosynthetic Pathway (HBP). This offshoot of the glycolytic pathway produces UDP-Nacetyl- glucosamine, which serves as the substrate for post-translational O-linked modification of proteins in a process referred to as O-GlcNAcylation. HBP flux and subsequent protein O-GlcNAcylation serve as nutrient sensors, enabling cells to integrate metabolic information to appropriately modulate fundamental cellular processes including gene expression. Here we summarize the impact of diabetes on retinal physiology, highlighting recent studies that explore the role of O-GlcNAcylation- induced variation in mRNA translation in retinal dysfunction and the pathogenesis of Diabetic Retinopathy (DR). Augmented O-GlcNAcylation results in wide variation in the selection of mRNAs for translation, in part, due to O-GlcNAcylation of the translational repressor 4E-BP1. Recent studies demonstrate that 4E-BP1 plays a critical role in regulating O-GlcNAcylation-induced changes in the translation of the mRNAs encoding Vascular Endothelial Growth Factor (VEGF), a number of important mitochondrial proteins, and CD40, a key costimulatory molecule involved in diabetes-induced retinal inflammation. Remarkably, 4E-BP1/2 ablation delays the onset of diabetes- induced visual dysfunction in mice. Thus, pharmacological interventions to prevent the impact of O-GlcNAcylation on 4E-BP1 may represent promising therapeutics to address the development and progression of DR. In this regard, we discuss the potential interplay between retinal O-GlcNAcylation and the ocular renin-angiotensin system as a potential therapeutic target of future interventions.
Collapse
Affiliation(s)
- Sadie K. Dierschke
- Department of Cellular and Molecular Physiology, Penn State College of Medicine
| | - Michael D. Dennis
- Department of Cellular and Molecular Physiology, Penn State College of Medicine
- Department of Ophthalmology, Penn State College of Medicine
- Address correspondence to this author at the Department of Cellular and Molecular Physiology, H166, Penn State College of Medicine, 500 University Drive Hershey, PA 17033; Tel: (717)531-0003 Ext-282596; Fax: (717)531-7667;
| |
Collapse
|
6
|
Starace V, Battista M, Brambati M, Cavalleri M, Bertuzzi F, Amato A, Lattanzio R, Bandello F, Cicinelli MV. The role of inflammation and neurodegeneration in diabetic macular edema. Ther Adv Ophthalmol 2021; 13:25158414211055963. [PMID: 34901746 PMCID: PMC8652911 DOI: 10.1177/25158414211055963] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 10/08/2021] [Indexed: 12/14/2022] Open
Abstract
The pathogenesis of diabetic macular edema (DME) is complex. Persistently high blood glucose activates multiple cellular pathways and induces inflammation, oxidation stress, and vascular dysfunction. Retinal ganglion cells, macroglial and microglial cells, endothelial cells, pericytes, and retinal pigment epithelium cells are involved. Neurodegeneration, characterized by dysfunction or apoptotic loss of retinal neurons, occurs early and independently from the vascular alterations. Despite the increasing knowledge on the pathways involved in DME, only limited therapeutic strategies are available. Besides antiangiogenic drugs and intravitreal corticosteroids, alternative therapeutic options tackling inflammation, oxidative stress, and neurodegeneration have been considered, but none of them has been currently approved.
Collapse
Affiliation(s)
- Vincenzo Starace
- Department of Ophthalmology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Marco Battista
- Department of Ophthalmology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Maria Brambati
- Department of Ophthalmology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Michele Cavalleri
- Department of Ophthalmology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Federico Bertuzzi
- Department of Ophthalmology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Alessia Amato
- Department of Ophthalmology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Rosangela Lattanzio
- Department of Ophthalmology, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Francesco Bandello
- Department of Ophthalmology, IRCCS San Raffaele Scientific Institute, Milan, ItalySchool of Medicine, Vita-Salute San Raffaele University, Milan, Italy
| | - Maria Vittoria Cicinelli
- Department of Ophthalmology, University Vita-Salute, IRCCS Ospedale San Raffaele, via Olgettina 60, 20132 Milan, ItalySchool of Medicine, Vita-Salute San Raffaele University, Milan, Italy
| |
Collapse
|
7
|
Liu S, Miyaji M, Hosoya O, Matsuo T. Effect of NK-5962 on Gene Expression Profiling of Retina in a Rat Model of Retinitis Pigmentosa. Int J Mol Sci 2021; 22:ijms222413276. [PMID: 34948073 PMCID: PMC8703378 DOI: 10.3390/ijms222413276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 12/03/2021] [Accepted: 12/06/2021] [Indexed: 11/18/2022] Open
Abstract
Purpose: NK-5962 is a key component of photoelectric dye-coupled polyethylene film, designated Okayama University type-retinal prosthesis (OUReP™). Previously, we found that NK-5962 solution could reduce the number of apoptotic photoreceptors in the eyes of the Royal College of Surgeons (RCS) rats by intravitreal injection under a 12 h light/dark cycle. This study aimed to explore possible molecular mechanisms underlying the anti-apoptotic effect of NK-5962 in the retina of RCS rats. Methods: RCS rats received intravitreal injections of NK-5962 solution in the left eye at the age of 3 and 4 weeks, before the age of 5 weeks when the speed in the apoptotic degeneration of photoreceptors reaches its peak. The vehicle-treated right eyes served as controls. All rats were housed under a 12 h light/dark cycle, and the retinas were dissected out at the age of 5 weeks for RNA sequence (RNA-seq) analysis. For the functional annotation of differentially expressed genes (DEGs), the Metascape and DAVID databases were used. Results: In total, 55 up-regulated DEGs, and one down-regulated gene (LYVE1) were found to be common among samples treated with NK-5962. These DEGs were analyzed using Gene Ontology (GO) term enrichment, Kyoto Encyclopedia of Genes and Genomes (KEGG), and Reactome pathway analyses. We focused on the up-regulated DEGs that were enriched in extracellular matrix organization, extracellular exosome, and PI3K–Akt signaling pathways. These terms and pathways may relate to mechanisms to protect photoreceptor cells. Moreover, our analyses suggest that SERPINF1, which encodes pigment epithelium-derived factor (PEDF), is one of the key regulatory genes involved in the anti-apoptotic effect of NK-5962 in RCS rat retinas. Conclusions: Our findings suggest that photoelectric dye NK-5962 may delay apoptotic death of photoreceptor cells in RCS rats by up-regulating genes related to extracellular matrix organization, extracellular exosome, and PI3K–Akt signaling pathways. Overall, our RNA-seq and bioinformatics analyses provide insights in the transcriptome responses in the dystrophic RCS rat retinas that were induced by NK-5962 intravitreal injection and offer potential target genes for developing new therapeutic strategies for patients with retinitis pigmentosa.
Collapse
Affiliation(s)
- Shihui Liu
- Department of Ophthalmology, Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University, Okayama City 700-8558, Japan;
| | - Mary Miyaji
- Department of Medical Neurobiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama City 700-8558, Japan; (M.M.); (O.H.)
| | - Osamu Hosoya
- Department of Medical Neurobiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama City 700-8558, Japan; (M.M.); (O.H.)
| | - Toshihiko Matsuo
- Department of Ophthalmology, Graduate School of Interdisciplinary Science and Engineering in Health Systems, Okayama University, Okayama City 700-8558, Japan;
- Correspondence:
| |
Collapse
|
8
|
Ipp E. Diabetic Retinopathy and Insulin Insufficiency: Beta Cell Replacement as a Strategy to Prevent Blindness. Front Endocrinol (Lausanne) 2021; 12:734360. [PMID: 34912295 PMCID: PMC8667804 DOI: 10.3389/fendo.2021.734360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 09/28/2021] [Indexed: 12/02/2022] Open
Abstract
Diabetic retinopathy (DR) is a potentially devastating complication of diabetes because it puts patients at risk of blindness. Diabetes is a common cause of blindness in the U.S. and worldwide and is dramatically increasing in global prevalence. Thus new approaches are needed to prevent this dreaded complication. There is extensive data that indicates beta cell secretory failure is a risk factor for DR, independent of its influence on glycemic control. This perspective article will provide evidence for insufficient endogenous insulin secretion as an important factor in the development of DR. The areas of evidence discussed are: (a) Presence of insulin receptors in the retina, (b) Clinical studies that show an association of beta cell insufficiency with DR, (c) Treatment with insulin in type 2 diabetes, a marker for endogenous insulin deficiency, is an independent risk factor for DR, (d) Recent clinical studies that link DR with an insulin deficient form of type 2 diabetes, and (e) Beta cell replacement studies that demonstrate endogenous insulin prevents progression of DR. The cumulative data drive our conclusion that beta cell replacement will have an important role in preventing DR and/or mitigating its severity in both type 1 diabetes and insulinopenic type 2 diabetes.
Collapse
Affiliation(s)
- Eli Ipp
- Department of Medicine, The Lundquist Institute at Harbor-University of California Los Angeles (UCLA) Medical Center, Torrance, CA, United States
| |
Collapse
|
9
|
Latina V, Giacovazzo G, Calissano P, Atlante A, La Regina F, Malerba F, Dell’Aquila M, Stigliano E, Balzamino BO, Micera A, Coccurello R, Amadoro G. Tau Cleavage Contributes to Cognitive Dysfunction in Strepto-Zotocin-Induced Sporadic Alzheimer's Disease (sAD) Mouse Model. Int J Mol Sci 2021; 22:ijms222212158. [PMID: 34830036 PMCID: PMC8618605 DOI: 10.3390/ijms222212158] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 11/04/2021] [Accepted: 11/07/2021] [Indexed: 01/15/2023] Open
Abstract
Tau cleavage plays a crucial role in the onset and progression of Alzheimer’s Disease (AD), a widespread neurodegenerative disease whose incidence is expected to increase in the next years. While genetic and familial forms of AD (fAD) occurring early in life represent less than 1%, the sporadic and late-onset ones (sAD) are the most common, with ageing being an important risk factor. Intracerebroventricular (ICV) infusion of streptozotocin (STZ)—a compound used in the systemic induction of diabetes due to its ability to damage the pancreatic β cells and to induce insulin resistance—mimics in rodents several behavioral, molecular and histopathological hallmarks of sAD, including memory/learning disturbance, amyloid-β (Aβ) accumulation, tau hyperphosphorylation, oxidative stress and brain glucose hypometabolism. We have demonstrated that pathological truncation of tau at its N-terminal domain occurs into hippocampi from two well-established transgenic lines of fAD animal models, such as Tg2576 and 3xTg mice, and that it’s in vivo neutralization via intravenous (i.v.) administration of the cleavage-specific anti-tau 12A12 monoclonal antibody (mAb) is strongly neuroprotective. Here, we report the therapeutic efficacy of 12A12mAb in STZ-infused mice after 14 days (short-term immunization, STIR) and 21 days (long-term immunization regimen, LTIR) of i.v. delivery. A virtually complete recovery was detected after three weeks of 12A12mAb immunization in both novel object recognition test (NORT) and object place recognition task (OPRT). Consistently, three weeks of this immunization regimen relieved in hippocampi from ICV-STZ mice the AD-like up-regulation of amyloid precursor protein (APP), the tau hyperphosphorylation and neuroinflammation, likely due to modulation of the PI3K/AKT/GSK3-β axis and the AMP-activated protein kinase (AMPK) activities. Cerebral oxidative stress, mitochondrial impairment, synaptic and histological alterations occurring in STZ-infused mice were also strongly attenuated by 12A12mAb delivery. These results further strengthen the causal role of N-terminal tau cleavage in AD pathogenesis and indicate that its specific neutralization by non-invasive administration of 12A12mAb can be a therapeutic option for both fAD and sAD patients, as well as for those showing type 2 diabetes as a comorbidity.
Collapse
Affiliation(s)
- Valentina Latina
- European Brain Research Institute (EBRI), Viale Regina Elena 295, 00161 Rome, Italy; (V.L.); (P.C.); (F.L.R.); (F.M.)
| | - Giacomo Giacovazzo
- IRCSS Santa Lucia Foundation, Via Fosso del Fiorano 64-65, 00143 Rome, Italy;
| | - Pietro Calissano
- European Brain Research Institute (EBRI), Viale Regina Elena 295, 00161 Rome, Italy; (V.L.); (P.C.); (F.L.R.); (F.M.)
| | - Anna Atlante
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies (IBIOM)-CNR, Via Amendola 122/O, 70126 Bari, Italy;
| | - Federico La Regina
- European Brain Research Institute (EBRI), Viale Regina Elena 295, 00161 Rome, Italy; (V.L.); (P.C.); (F.L.R.); (F.M.)
| | - Francesca Malerba
- European Brain Research Institute (EBRI), Viale Regina Elena 295, 00161 Rome, Italy; (V.L.); (P.C.); (F.L.R.); (F.M.)
| | - Marco Dell’Aquila
- Area of Pathology, Department of Woman and Child Health and Public Health, Fondazione Policlinico Universitario A. Gemelli IRCCS, Istituto di Anatomia Patologica, Università Cattolica del Sacro Cuore, Largo Francesco Vito, 1, 00168 Rome, Italy; (M.D.); (E.S.)
| | - Egidio Stigliano
- Area of Pathology, Department of Woman and Child Health and Public Health, Fondazione Policlinico Universitario A. Gemelli IRCCS, Istituto di Anatomia Patologica, Università Cattolica del Sacro Cuore, Largo Francesco Vito, 1, 00168 Rome, Italy; (M.D.); (E.S.)
| | - Bijorn Omar Balzamino
- Research Laboratories in Ophthalmology, IRCCS-Fondazione Bietti, Via Santo Stefano Rotondo, 6I, 00184 Rome, Italy; (B.O.B.); (A.M.)
| | - Alessandra Micera
- Research Laboratories in Ophthalmology, IRCCS-Fondazione Bietti, Via Santo Stefano Rotondo, 6I, 00184 Rome, Italy; (B.O.B.); (A.M.)
| | - Roberto Coccurello
- IRCSS Santa Lucia Foundation, Via Fosso del Fiorano 64-65, 00143 Rome, Italy;
- Institute for Complex System (ISC)-CNR, Via dei Taurini 19, 00185 Rome, Italy
- Correspondence: (R.C.); (G.A.)
| | - Giuseppina Amadoro
- European Brain Research Institute (EBRI), Viale Regina Elena 295, 00161 Rome, Italy; (V.L.); (P.C.); (F.L.R.); (F.M.)
- Institute of Translational Pharmacology (IFT)-CNR, Via Fosso del Cavaliere 100, 00133 Rome, Italy
- Correspondence: (R.C.); (G.A.)
| |
Collapse
|
10
|
Tang LHC, Fung FKC, Lai AKW, Wong IYH, Shih KC, Lo ACY. Autophagic Upregulation Is Cytoprotective in Ischemia/Reperfusion-Injured Retina and Retinal Progenitor Cells. Int J Mol Sci 2021; 22:8446. [PMID: 34445152 PMCID: PMC8395130 DOI: 10.3390/ijms22168446] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 08/02/2021] [Accepted: 08/03/2021] [Indexed: 11/16/2022] Open
Abstract
The cytoprotective versus cytotoxic role of macroautophagy in ocular ischemia/reperfusion injuries remains controversial and its effects under hyperglycemia are unclear. We investigated the involvement of autophagy in in vitro and in vivo normoglycemic and hyperglycemic models of retinal ischemia/reperfusion injury. Retinal ischemia (2 h) and reperfusion (2 or 22 h) was induced in wild-type and type I diabetic Ins2Akita/+ mice using a middle cerebral artery occlusion model. R28 retinal precursor cells were subjected to CoCl2-induced hypoxia with or without autophagic inhibitor NH4Cl. Autophagic regulation during ischemia/reperfusion was assessed through immunohistochemical detection and Western blotting of microtubule-associated protein 1A/1B-light chain 3 (LC3) and lysosomal associated membrane protein 1 (LAMP1). Effect of autophagic inhibition on cell viability and morphology under hypoxic conditions was also evaluated. Upregulation of autophagic markers in the inner retinae was seen after two hours reperfusion, with tapering of the response following 22 h of reperfusion in vivo. LC3-II turnover assays confirmed an increase in autophagic flux in our hypoxic in vitro model. Pharmacological autophagic inhibition under hypoxic conditions decreased cell survival and induced structural changes not demonstrated with autophagic inhibition alone. Yet no statistically significant different autophagic responses in ischemia/reperfusion injuries were seen between the two glycemic states.
Collapse
Affiliation(s)
| | | | | | | | | | - Amy Cheuk Yin Lo
- Department of Ophthalmology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong; (L.H.C.T.); (F.K.C.F.); (A.K.W.L.); (I.Y.H.W.); (K.C.S.)
| |
Collapse
|
11
|
Diabetic retinal neurodegeneration as a form of diabetic retinopathy. Int Ophthalmol 2021; 41:3223-3248. [PMID: 33954860 DOI: 10.1007/s10792-021-01864-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 04/08/2021] [Indexed: 12/11/2022]
Abstract
PURPOSE To review the evidence supporting diabetic retinal neurodegeneration (DRN) as a form of diabetic retinopathy. METHOD Review of literature. RESULTS DRN is recognized to be a part of retinopathy in patients with diabetes mellitus (DM), in addition to the well-established diabetic retinal vasculopathy (DRV). DRN has been noted in the early stages of DM, before the onset of clinically evident diabetic retinopathy. The occurrence of DRN has been confirmed in animal models of DM, histopathological examination of donor's eyes from diabetic individuals and assessment of neural structure and function in humans. DRN involves alterations in retinal ganglion cells, photoreceptors, amacrine cells and bipolar cells, and is thought to be driven by glutamate, oxidative stress and dysregulation of neuroprotective factors in the retina. Potential therapeutic options for DRN are under evaluation. CONCLUSIONS Literature is divided on the temporal relation between DRN and DRV, with evidence of both precedence and simultaneous occurrence. The relationship between DRN and multi-system neuropathy in DM is yet to be evaluated critically.
Collapse
|
12
|
Nian S, Lo ACY, Mi Y, Ren K, Yang D. Neurovascular unit in diabetic retinopathy: pathophysiological roles and potential therapeutical targets. EYE AND VISION 2021; 8:15. [PMID: 33931128 PMCID: PMC8088070 DOI: 10.1186/s40662-021-00239-1] [Citation(s) in RCA: 47] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 04/02/2021] [Indexed: 02/06/2023]
Abstract
Diabetic retinopathy (DR), one of the common complications of diabetes, is the leading cause of visual loss in working-age individuals in many industrialized countries. It has been traditionally regarded as a purely microvascular disease in the retina. However, an increasing number of studies have shown that DR is a complex neurovascular disorder that affects not only vascular structure but also neural tissue of the retina. Deterioration of neural retina could precede microvascular abnormalities in the DR, leading to microvascular changes. Furthermore, disruption of interactions among neurons, vascular cells, glia and local immune cells, which collectively form the neurovascular unit, is considered to be associated with the progression of DR early on in the disease. Therefore, it makes sense to develop new therapeutic strategies to prevent or reverse retinal neurodegeneration, neuroinflammation and impaired cell-cell interactions of the neurovascular unit in early stage DR. Here, we present current perspectives on the pathophysiology of DR as a neurovascular disease, especially at the early stage. Potential novel treatments for preventing or reversing neurovascular injuries in DR are discussed as well.
Collapse
Affiliation(s)
- Shen Nian
- Department of Pathology, Xi'an Medical University, Xi'an, Shaanxi Province, China.
| | - Amy C Y Lo
- Department of Ophthalmology, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong, Hong Kong
| | - Yajing Mi
- Institute of Basic Medicine Science, Xi'an Medical University, Xi'an, Shaanxi Province, China
| | - Kai Ren
- Department of Biochemistry and Molecular Biology, Xi'an Medical University, Xi'an, Shaanxi Province, China
| | - Di Yang
- Department of Ophthalmology, First Affiliated Hospital of Kunming Medical University, Kunming Medical University, Kunming, Yunnan Province, China.
| |
Collapse
|
13
|
Zolov SN, Imai H, Losiewicz MK, Singh RSJ, Fort PE, Gardner TW. Insulin-like growth factor-2 regulates basal retinal insulin receptor activity. J Biol Chem 2021; 296:100712. [PMID: 33915127 PMCID: PMC8138762 DOI: 10.1016/j.jbc.2021.100712] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 04/15/2021] [Accepted: 04/23/2021] [Indexed: 11/14/2022] Open
Abstract
The retinal insulin receptor (IR) exhibits basal kinase activity equivalent to that of the liver of fed animals, but unlike the liver, does not fluctuate with feeding and fasting; it also declines rapidly after the onset of insulin-deficient diabetes. The ligand(s) that determine basal IR activity in the retina has not been identified. Using a highly sensitive insulin assay, we found that retinal insulin concentrations remain constant in fed versus fasted rats and in diabetic versus control rats; vitreous fluid insulin levels were undetectable. Neutralizing antibodies against insulin-like growth factor 2 (IGF-2), but not insulin-like growth factor 1 (IGF-1) or insulin, decreased IR kinase activity in normal rat retinas, and depletion of IGF-2 from serum specifically reduced IR phosphorylation in retinal cells. Immunoprecipitation studies demonstrated that IGF-2 induced greater phosphorylation of the retinal IR than the IGF-1 receptor. Retinal IGF-2 mRNA content was 10-fold higher in adults than pups and orders of magnitude higher than in liver. Diabetes reduced retinal IGF-2, but not IGF-1 or IR, mRNA levels, and reduced IGF-2 and IGF-1 content in vitreous fluid. Finally, intravitreal administration of IGF-2 (mature and pro-forms) increased retinal IR and Akt kinase activity in diabetic rats. Collectively, these data reveal that IGF-2 is the primary ligand that defines basal retinal IR activity and suggest that reduced ocular IGF-2 may contribute to reduced IR activity in response to diabetes. These findings may have importance for understanding the regulation of metabolic and prosurvival signaling in the retina.
Collapse
Affiliation(s)
- Sergey N Zolov
- Department of Ophthalmology & Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, USA; Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA; The Division of Pulmonary & Critical Care Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA.
| | - Hisanori Imai
- Department of Ophthalmology, Kobe University Medical School, Kobe, Japan
| | - Mandy K Losiewicz
- Department of Ophthalmology & Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | | | - Patrice E Fort
- Department of Ophthalmology & Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, USA; Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Thomas W Gardner
- Department of Ophthalmology & Visual Sciences, University of Michigan Medical School, Ann Arbor, Michigan, USA; Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USA; Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| |
Collapse
|
14
|
Abstract
The field of phosphoinositide signaling has expanded significantly in recent years. Phosphoinositides (also known as phosphatidylinositol phosphates or PIPs) are universal signaling molecules that directly interact with membrane proteins or with cytosolic proteins containing domains that directly bind phosphoinositides and are recruited to cell membranes. Through the activities of phosphoinositide kinases and phosphoinositide phosphatases, seven distinct phosphoinositide lipid molecules are formed from the parent molecule, phosphatidylinositol. PIP signals regulate a wide range of cellular functions, including cytoskeletal assembly, membrane budding and fusion, ciliogenesis, vesicular transport, and signal transduction. Given the many excellent reviews on phosphoinositide kinases, phosphoinositide phosphatases, and PIPs in general, in this review, we discuss recent studies and advances in PIP lipid signaling in the retina. We specifically focus on PIP lipids from vertebrate (e.g., bovine, rat, mouse, toad, and zebrafish) and invertebrate (e.g., Drosophila, horseshoe crab, and squid) retinas. We also discuss the importance of PIPs revealed from animal models and human diseases, and methods to study PIP levels both in vitro and in vivo. We propose that future studies should investigate the function and mechanism of activation of PIP-modifying enzymes/phosphatases and further unravel PIP regulation and function in the different cell types of the retina.
Collapse
Affiliation(s)
- Raju V S Rajala
- Departments of Ophthalmology, Physiology, and Cell Biology, and Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104.
| |
Collapse
|
15
|
Bürger S, Meng J, Zwanzig A, Beck M, Pankonin M, Wiedemann P, Eichler W, Unterlauft JD. Pigment Epithelium-Derived Factor (PEDF) Receptors Are Involved in Survival of Retinal Neurons. Int J Mol Sci 2020; 22:E369. [PMID: 33396450 PMCID: PMC7795132 DOI: 10.3390/ijms22010369] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 12/25/2020] [Accepted: 12/28/2020] [Indexed: 02/02/2023] Open
Abstract
The demise of retinal ganglion cells (RGCs) is characteristic of diseases of the retina such as glaucoma and diabetic or ischemic retinopathies. Pigment epithelium-derived factor (PEDF) is a multifunctional secreted protein that mediates neuroprotection and inhibition of angiogenesis in the retina. We have studied expression and regulation of two of several receptors for PEDF, patatin-like phospholipase 2 gene product/PEDF-R and laminin receptor (LR), in serum-starved RGC under normoxia and hypoxia and investigated their involvement in the survival of retinal neuronal cells. We show that PEDF-R and LR are co-expressed in RGC and R28 retinal precursor cells. Expression of both receptors was enhanced in the presence of complex secretions from retinal glial (Müller) cells and upregulated by VEGF and under hypoxic conditions. PEDF-R- and LR-knocked-down cells demonstrated a markedly attenuated expression of anti-apoptotic Bcl-2 family members (Bcl-2, Bcl-xL) and neuroprotective mediators (PEDF, VEGF, BDNF) suggesting that both PEDF-R and LR mediate pro-survival effects of PEDF on RGC. While this study does not provide evidence for a differential survival-promoting influence of either PEDF-R or LR, it nevertheless highlights the importance of both PEDF receptors for the viability of retinal neurons.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Wolfram Eichler
- Department of Ophthalmology and Eye Hospital, Leipzig University, Liebigstrasse 10-14, D-04103 Leipzig, Germany; (S.B.); (J.M.); (A.Z.); (M.B.); (M.P.); (P.W.); (J.D.U.)
| | | |
Collapse
|
16
|
HDAC inhibition ameliorates cone survival in retinitis pigmentosa mice. Cell Death Differ 2020; 28:1317-1332. [PMID: 33159184 PMCID: PMC8026998 DOI: 10.1038/s41418-020-00653-3] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 10/12/2020] [Accepted: 10/15/2020] [Indexed: 12/27/2022] Open
Abstract
Cone photoreceptor cell death in inherited retinal diseases, such as Retinitis Pigmentosa (RP), leads to the loss of high acuity and color vision and, ultimately to blindness. In RP, a vast number of mutations perturb the structure and function of rod photoreceptors, while cones remain initially unaffected. Extensive rod loss in advanced stages of the disease triggers cone death by a mechanism that is still largely unknown. Here, we show that secondary cone cell death in animal models for RP is associated with increased activity of histone deacetylates (HDACs). A single intravitreal injection of an HDAC inhibitor at late stages of the disease, when the majority of rods have already degenerated, was sufficient to delay cone death and support long-term cone survival in two mouse models for RP, affected by mutations in the phosphodiesterase 6b gene. Moreover, the surviving cones remained light-sensitive, leading to an improvement in visual function. RNA-seq analysis of protected cones demonstrated that HDAC inhibition initiated multi-level protection via regulation of different pro-survival pathways, including MAPK, PI3K-Akt, and autophagy. This study suggests a unique opportunity for targeted pharmacological protection of secondary dying cones by HDAC inhibition and creates hope to maintain vision in RP patients even in advanced disease stages.
Collapse
|
17
|
Kakavand K, Jobling AI, Greferath U, Vessey KA, de Iongh RU, Fletcher EL. Photoreceptor Degeneration in Pro23His Transgenic Rats (Line 3) Involves Autophagic and Necroptotic Mechanisms. Front Neurosci 2020; 14:581579. [PMID: 33224023 PMCID: PMC7670078 DOI: 10.3389/fnins.2020.581579] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 10/02/2020] [Indexed: 01/09/2023] Open
Abstract
Photoreceptor death contributes to 50% of irreversible vision loss in the western world. Pro23His (P23H) transgenic albino rat strains are widely used models for the most common rhodopsin gene mutation associated with the autosomal dominant form of retinitis pigmentosa. However, the mechanism(s) by which photoreceptor death occurs are not well understood and were the principal aim of this study. We first used electroretinogram recording and optical coherence tomography to confirm the time course of functional and structural loss. Electroretinogram analyses revealed significantly decreased rod photoreceptor (a-wave), bipolar cell (b-wave) and amacrine cell responses (oscillatory potentials) from P30 onward. The cone-mediated b-wave was also decreased from P30. TUNEL analysis showed extensive cell death at P18, with continued labeling detected until P30. Focused gene expression arrays indicated activation of, apoptosis, autophagy and necroptosis in whole retina from P14-18. However, analysis of mitochondrial permeability changes (ΔΨm) using JC-1 dye, combined with immunofluorescence markers for caspase-dependent (cleaved caspase-3) and caspase-independent (AIF) cell death pathways, indicated mitochondrial-mediated cell death was not a major contributor to photoreceptor death. By contrast, reverse-phase protein array data combined with RIPK3 and phospho-MLKL immunofluorescence indicated widespread necroptosis as the predominant mechanism of photoreceptor death. These findings highlight the complexity of mechanisms involved in photoreceptor death in the Pro23His rat model of degeneration and suggest therapies that target necroptosis should be considered for their potential to reduce photoreceptor death.
Collapse
Affiliation(s)
- Kiana Kakavand
- Visual Neuroscience Laboratory, Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, VIC, Australia
| | - Andrew I Jobling
- Visual Neuroscience Laboratory, Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, VIC, Australia
| | - Ursula Greferath
- Visual Neuroscience Laboratory, Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, VIC, Australia
| | - Kirstan A Vessey
- Visual Neuroscience Laboratory, Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, VIC, Australia
| | - Robb U de Iongh
- Ocular Development Laboratory, Department Anatomy and Neuroscience, The University of Melbourne, Parkville, VIC, Australia
| | - Erica L Fletcher
- Visual Neuroscience Laboratory, Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, VIC, Australia
| |
Collapse
|
18
|
Cdk5-mediated Drp1 phosphorylation drives mitochondrial defects and neuronal apoptosis in radiation-induced optic neuropathy. Cell Death Dis 2020; 11:720. [PMID: 32883957 PMCID: PMC7473761 DOI: 10.1038/s41419-020-02922-y] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 08/22/2020] [Accepted: 08/24/2020] [Indexed: 12/14/2022]
Abstract
Radiation-induced optic neuropathy (RION) is a devastating complication following external beam radiation therapy (EBRT) that leads to acute vision loss. To date, no efficient, available treatment for this complication, due partly to the lack of understanding regarding the developmental processes behind RION. Here, we report radiation caused changes in mitochondrial dynamics by regulating the mitochondrial fission proteins dynamin-related protein 1 (Drp1) and fission-1 (Fis1). Concurrent with an excessive production of reactive oxygen species (ROS), both neuronal injury and visual dysfunction resulted. Further, our findings delineate an important mechanism by which cyclin-dependent kinase 5 (Cdk5)-mediated phosphorylation of Drp1 (Ser616) regulates defects in mitochondrial dynamics associated with neuronal injury in the development of RION. Both the pharmacological inhibition of Cdk5 by roscovitine and the inhibition of Drp1 by mdivi-1 inhibited mitochondrial fission and the production of ROS associated with radiation-induced neuronal loss. Taken together, these findings may have clinical significance in preventing the development of RION.
Collapse
|
19
|
Britto FA, Dumas K, Giorgetti-Peraldi S, Ollendorff V, Favier FB. Is REDD1 a metabolic double agent? Lessons from physiology and pathology. Am J Physiol Cell Physiol 2020; 319:C807-C824. [PMID: 32877205 DOI: 10.1152/ajpcell.00340.2020] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The Akt/mechanistic target of rapamycin (mTOR) signaling pathway governs macromolecule synthesis, cell growth, and metabolism in response to nutrients and growth factors. Regulated in development and DNA damage response (REDD)1 is a conserved and ubiquitous protein, which is transiently induced in response to multiple stimuli. Acting like an endogenous inhibitor of the Akt/mTOR signaling pathway, REDD1 protein has been shown to regulate cell growth, mitochondrial function, oxidative stress, and apoptosis. Recent studies also indicate that timely REDD1 expression limits Akt/mTOR-dependent synthesis processes to spare energy during metabolic stresses, avoiding energy collapse and detrimental consequences. In contrast to this beneficial role for metabolic adaptation, REDD1 chronic expression appears involved in the pathogenesis of several diseases. Indeed, REDD1 expression is found as an early biomarker in many pathologies including inflammatory diseases, cancer, neurodegenerative disorders, depression, diabetes, and obesity. Moreover, prolonged REDD1 expression is associated with cell apoptosis, excessive reactive oxygen species (ROS) production, and inflammation activation leading to tissue damage. In this review, we decipher several mechanisms that make REDD1 a likely metabolic double agent depending on its duration of expression in different physiological and pathological contexts. We also discuss the role played by REDD1 in the cross talk between the Akt/mTOR signaling pathway and the energetic metabolism.
Collapse
Affiliation(s)
| | - Karine Dumas
- Université Cote d'Azur, INSERM, UMR1065, C3M, Nice, France
| | | | | | | |
Collapse
|
20
|
Öztürk H, Özen B, Manyas H, Çatlı G, Dündar B. Can ocular changes be detected early in children and adolescents with type 1 diabetes mellitus without retinopathy by using optical biometry and optical coherence tomography? Int Ophthalmol 2020; 40:2503-2514. [PMID: 32488589 DOI: 10.1007/s10792-020-01430-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 05/16/2020] [Indexed: 12/17/2022]
Abstract
PURPOSE To determine early ocular changes in children and adolescents with type 1 diabetes mellitus without retinopathy (T1DM-woR) by optical biometry (OB) and optical coherence tomography (OCT). METHODS Seventy children and adolescents with T1DM-woR (patient group) and 72 healthy children and adolescents (control group) were included. Demographic data, anthropometric measurements and anterior-posterior segment parameters of groups were compared. Correlations between ocular parameters and glycosylated hemoglobin (HbA1c) level, age at diabetes mellitus (DM) onset and DM duration were evaluated. RESULTS Patients with T1DM-woR had significantly shallower anterior chambers (3.50 ± 0.12 vs 3.67 ± 0.11 mm, p < 0.001), thicker lenses (3.65 ± 0.15 vs 3.37 ± 0.14 mm, p < 0.001), thinner central retinal nerve fiber layer (RNFL) thicknesses (95.3 ± 6.7 vs 104.8 ± 6.2 µm, p < 0.001) and thinner central choroidal thicknesses (292.8 ± 23.6 vs 325.1 ± 24.7 µm, p < 0.001) than healthy individuals. As the lens thickness (LT) increased, anterior chamber depth (ACD) decreased in patient group (r = - 0.368, p = 0.040). Other anterior (central corneal thickness, axial length, keratometry, spherical equivalent) and posterior (superior temporal, superior nasal, nasal, inferior nasal, inferior temporal, temporal RNFL thicknesses; nasal and temporal choroidal thicknesses; central part's and inner-outer macular segments' thickness and volume measurements) segment parameters of groups were similar (p > 0.05). In patient group, as HbA1c level increased, central RNFL and choroidal thicknesses decreased (r = - 0.639, p < 0.001; r = - 0.486, p = 0.010, respectively). CONCLUSIONS In patients with T1DM, we found that LT increased, and ACD, central RNFL and choroidal thicknesses decreased by OB and OCT before visible findings appeared in routine ophthalmological examination. Determination of early changes is warning to physician and patient in order to prevent more serious damages occurring later.
Collapse
Affiliation(s)
- Hakan Öztürk
- Department of Ophthalmology, Tepecik Training and Research Hospital, Yenisehir, Izmir, Turkey.
| | - Bediz Özen
- Department of Ophthalmology, Tepecik Training and Research Hospital, Yenisehir, Izmir, Turkey
| | - Hayrullah Manyas
- Faculty of Medicine, Department of Pediatric Endocrinology, Izmir Katip Celebi University, Izmir, Turkey
| | - Gönül Çatlı
- Faculty of Medicine, Department of Pediatric Endocrinology, Izmir Katip Celebi University, Izmir, Turkey
| | - Bumin Dündar
- Faculty of Medicine, Department of Pediatric Endocrinology, Izmir Katip Celebi University, Izmir, Turkey
| |
Collapse
|
21
|
Gerendas BS, Hatz K, Kaider A, Zulewski H, Lehmann R, Montuoro A, Schmidt‐Erfurth U, Pruente C. Ganglion cell layer thickening in well-controlled patients with type 1 diabetes: an early sign for diabetic retinopathy? Acta Ophthalmol 2020; 98:e292-e300. [PMID: 31654495 PMCID: PMC7216836 DOI: 10.1111/aos.14273] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Accepted: 09/14/2019] [Indexed: 01/14/2023]
Abstract
PURPOSE To evaluate early changes in retinal layers using optical coherence tomography (OCT) in patients with long-standing type 1 diabetes (DM1) receiving intensified insulin therapy. METHODS In a cross-sectional case-control study 150 patients with DM1 and 150 age- and sex-matched healthy control participants underwent OCT imaging. Scans of both eyes were analysed for different layers (NFL, GCL (+IPL), INL, outer layer complex (OLC, including OPL, ONL and ELM) and photoreceptors (PR)) in all subfields of an ETDRS grid. All analyses were performed semi-automatically using custom software by certified graders of the Vienna Reading Center. ANOVA models were used to compare the mean thickness of the layers between patients and controls. RESULTS Six hundred eyes with 512 datapoints in 49 b-scans in each OCT were analysed. Mean thickness in patients/controls was 31.35 μm/30.65 μm (NFL, p = 0.0347), 76.7 μm/73.15 μm (GCL, p ≤ 0.0001), 36.29 μm/37.13 μm (INL, p = 0.0116), 114.34 μm/112.02 μm (OLC, p < 0.0001) and 44.71 μm/44.69 μm (PR, p = 0.9401). When evaluating the ETDRS subfields separately for clinically meaningful hypotheses, a significant swelling of the GCL in patients could be found uniformly and a central swelling for the OLC, whereas the distribution of NFL and INL thickening suggests that their statistical significance was not clinically relevant. CONCLUSION These preliminary results demonstrate that preclinical retinal changes in patients with long-standing DM1 can be found by retinal layer evaluation. However, the changes are layer-specific, with significant thickening of the GCL and less so of the OLC suggesting a role as an early sign for diffuse swelling and the evolution of DME even in well-controlled diabetes.
Collapse
Affiliation(s)
- Bianca S. Gerendas
- Vienna Reading CenterDepartment of OphthalmologyMedical University of ViennaViennaAustria
| | - Katja Hatz
- Vienna Reading CenterDepartment of OphthalmologyMedical University of ViennaViennaAustria,Vista Klinik BinningenBinningenSwitzerland,Department of OphthalmologyUniversity of BaselBaselSwitzerland
| | - Alexandra Kaider
- Center for Medical StatisticsInformatics and Intelligent SystemsSection for Clinical BiometricsMedical University of ViennaViennaAustria
| | - Henryk Zulewski
- Department of EndocrinologyUniversity of BaselBaselSwitzerland
| | - Roger Lehmann
- Department of EndocrinologyUniversity of ZuerichZuerichSwitzerland
| | - Alessio Montuoro
- Vienna Reading CenterDepartment of OphthalmologyMedical University of ViennaViennaAustria
| | - Ursula Schmidt‐Erfurth
- Vienna Reading CenterDepartment of OphthalmologyMedical University of ViennaViennaAustria
| | - Christian Pruente
- Department of OphthalmologyUniversity of BaselBaselSwitzerland,Department of OphthalmologyKantonsspital LiestalLiestalSwitzerland,Institute of Molecular and Clinical OphthalmologyBaselSwitzerland
| |
Collapse
|
22
|
Chung YW, Lee JH, Lee JY, Ju HH, Lee YJ, Jee DH, Ko SH, A Choi J. The Anti-Inflammatory Effects of Glucagon-Like Peptide Receptor Agonist Lixisenatide on the Retinal Nuclear and Nerve Fiber Layers in an Animal Model of Early Type 2 Diabetes. THE AMERICAN JOURNAL OF PATHOLOGY 2020; 190:1080-1094. [PMID: 32354571 DOI: 10.1016/j.ajpath.2020.01.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Revised: 01/11/2020] [Accepted: 01/17/2020] [Indexed: 12/30/2022]
Abstract
This study explored the anti-inflammatory effects of a glucagon-like peptide-1 receptor agonist (GLP-1RA), known as lixisenatide, on the eyes of early type 2 diabetic mice. Diabetic (db/db) mice were divided into three groups: GLP-1RA [lixisenatide (LIX)], insulin (INS) with controlled hyperglycemia based on the glucose concentration of lixisenatide, and diabetic control (D-CON). Nondiabetic control mice (db/dm) were also characterized for comparison. After 8 weeks of treatment, mRNA levels of inflammatory markers, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling, immunohistochemical staining; Western blot of glial fibrillary acidic protein (GFAP) and thioredoxin-interacting protein; and retinal thickness were assessed in the central and peripheral neurosensory retina. LIX showed decreased immunohistochemical staining for both thioredoxin-interacting protein and GFAP in the central and peripheral neurosensory retina compared with D-CON and INS, and decreased expression of these proteins in the neurosensory retina and immunohistochemical staining in the optic nerve head for GFAP compared with D-CON. The inner nuclear layer in the peripheral retina in LIX was only thinner than those of D-CON and INS. In an early type 2 diabetic mouse model, lixisenatide treatment showed superior anti-inflammatory effects on the retina and optic nerve head independent of hyperglycemia. Thus, the neuroprotective effects of lixisenatide treatment in the peripheral inner nuclear layer should be evaluated in early type 2 diabetic retinopathy.
Collapse
Affiliation(s)
- Yeon Woong Chung
- Department of Ophthalmology and Visual Science, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Jae Hyung Lee
- Department of Ophthalmology and Visual Science, St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Ji Young Lee
- Department of Ophthalmology and Visual Science, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Hyun Hee Ju
- Clinical Research Center, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Ye-Jee Lee
- Division of Endocrinology & Metabolism, Department of Internal Medicine, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Dong Hyun Jee
- Department of Ophthalmology and Visual Science, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Seung-Hyun Ko
- Division of Endocrinology & Metabolism, Department of Internal Medicine, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Jin A Choi
- Department of Ophthalmology and Visual Science, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
| |
Collapse
|
23
|
Sciarretta F, Fulci C, Palumbo C, Aquilano K, Pastore A, Iorio E, Lettieri-Barbato D, Cicconi R, Minutolo A, Parravano M, Gilardi M, Varano M, Caccuri AM. Glutathione transferase P silencing promotes neuronal differentiation of retinal R28 cells. J Cell Physiol 2019; 234:15885-15897. [PMID: 30741416 DOI: 10.1002/jcp.28246] [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: 07/01/2018] [Revised: 01/14/2019] [Accepted: 01/15/2019] [Indexed: 01/24/2023]
Abstract
Glutathione transferases (GSTs) play an important role in retinal pathophysiology. Within this family, the GSTP isoform is known as an endogenous regulator of cell survival and proliferation pathways and of cellular responses to oxidative stress. In the present study we silenced GSTP in R28 cells, a retinal precursor cell line with markers of both glial and neuronal origin, and obtained stable clones which were viable and, unexpectedly, characterized by a more neuronal phenotype. The degree of neuronal differentiation was inversely correlated with GSTP residual expression levels. The clone with the lowest expression of GSTP showed metabolic reprogramming, a more favorable redox status and, despite its neuronal phenotype, a sensitivity to glutamate and 4-hydroxynonenal toxicity comparable to that of control cells. Altogether, our evidence shows that near full depletion of GSTP in retinal precursor cells, triggers neuronal differentiation and prosurvival metabolic changes.
Collapse
Affiliation(s)
- Francesca Sciarretta
- Department of Experimental Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Chiara Fulci
- Department of Experimental Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Camilla Palumbo
- Department of Clinical Sciences and Translational Medicine, University of Rome Tor Vergata, Rome, Italy
| | - Katia Aquilano
- Department of Biology, University of Rome Tor Vergata, Rome, Italy
| | - Anna Pastore
- Laboratory of Molecular Genetics and Functional Genomics, Division of Genetic and Rare Disease, Children's Hospital and Research Institute Bambino Gesù, Rome, Italy
| | - Egidio Iorio
- Core Facilities, High Resolution NMR Unit, Istituto Superiore di Sanità, Rome, Italy
| | | | - Rosella Cicconi
- Interdepartmental Service Centre - Station for Animal Technology (STA), University of Rome Tor Vergata, Rome, Italy
| | | | | | - Marta Gilardi
- Ophthalmology, IRCCS-G.B. Bietti Foundation, Rome, Italy
| | - Monica Varano
- Ophthalmology, IRCCS-G.B. Bietti Foundation, Rome, Italy
| | - Anna Maria Caccuri
- Department of Experimental Medicine, University of Rome Tor Vergata, Rome, Italy.,Interdepartmental Centre for Nanosciences, Nanotechnologies, Innovative Instrumentation (NAST), University of Rome Tor Vergata, Rome, Italy
| |
Collapse
|
24
|
Tan J, Digicaylioglu M, Wang SX, Dresselhuis J, Dedhar S, Mills J. Insulin attenuates apoptosis in neuronal cells by an integrin-linked kinase-dependent mechanism. Heliyon 2019; 5:e02294. [PMID: 31463398 PMCID: PMC6706370 DOI: 10.1016/j.heliyon.2019.e02294] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Revised: 06/04/2019] [Accepted: 08/08/2019] [Indexed: 01/19/2023] Open
Abstract
Insulin promotes neuronal survival by activating a phosphatidylinositol 3-kinase (PI 3-kinase)/AKT-dependent signaling pathway and reducing caspase activation. We investigated a role for integrin-linked kinase (ILK) in insulin-mediated cell survival in cultured neurons and differentiated R28 cells. We used a serum and depolarization withdrawal model to induce apoptosis in cerebellar granule neurons and a serum withdrawal model to induce apoptosis in differentiated R28 cells. ILK knock-out decreased insulin-mediated protection as did the addition of pharmacological inhibitors of ILK, KP-392 or QLT-0267. Prosurvival effects of insulin were rescued by Boc-Asp (O-methyl)-CH2F (BAF), a pancaspase inhibitor, in the presence of KP-392. Insulin and IGF-1 decreased caspase-3 activation, an effect that was inhibited by KP-392 and QLT-0267. Western blot analysis indicates that insulin-induced stimulation of AKT Ser-473 phosphorylation was decreased after the ILK gene was conditionally knocked-out, following overexpression of AKT-DN or in the presence of QLT-0267. Insulin and IGF-1 stimulated ILK kinase activity in primary neurons and this was inhibited following ILK-DN overexpression. Western blot analysis indicates that insulin exposure upregulated the expression of the cellular inhibitor of apoptosis protein c-IAP2 in an extracellular matrix-dependent manner, an effect blocked by KP-392. These results indicate that ILK is an important effector in insulin-mediated neuroprotection.
Collapse
Affiliation(s)
- Jacqueline Tan
- Department of Biology, Trinity Western University, Langley, British Columbia, Canada
| | - Murat Digicaylioglu
- Departments of Neurosurgery and Physiology, Scripps Research, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Stacy X.J. Wang
- Department of Biology, Trinity Western University, Langley, British Columbia, Canada
| | - Jonathan Dresselhuis
- Department of Biology, Trinity Western University, Langley, British Columbia, Canada
| | - Shoukat Dedhar
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Julia Mills
- Department of Biology, Trinity Western University, Langley, British Columbia, Canada
- Corresponding author.
| |
Collapse
|
25
|
Kern TS, Antonetti DA, Smith LEH. Pathophysiology of Diabetic Retinopathy: Contribution and Limitations of Laboratory Research. Ophthalmic Res 2019; 62:196-202. [PMID: 31362288 PMCID: PMC6872907 DOI: 10.1159/000500026] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 03/29/2019] [Indexed: 12/11/2022]
Abstract
Preclinical models of diabetic retinopathy are indispensable in the drug discovery and development of new therapies. They are, however, imperfect facsimiles of diabetic retinopathy in humans. This chapter discusses the advantages, limitations, and physiological and pathological relevance of preclinical models of diabetic retinopathy. The judicious interpretation and extrapolation of data derived from these models to humans and a correspondingly greater emphasis placed on translational medical research in early-stage clinical trials are essential to more successfully inhibit the development and progression of diabetic retinopathy in the future.
Collapse
Affiliation(s)
- Timothy S Kern
- Gavin Herbert Eye Institute, University of California Irvine, Irvine, California, USA,
- Veterans Administration Medical Center Research Service 151, Cleveland, Ohio, USA,
| | - David A Antonetti
- Kellogg Eye Center, Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan, USA
| | - Lois E H Smith
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| |
Collapse
|
26
|
New Insights into the Mechanisms of Action of Topical Administration of GLP-1 in an Experimental Model of Diabetic Retinopathy. J Clin Med 2019; 8:jcm8030339. [PMID: 30862093 PMCID: PMC6463072 DOI: 10.3390/jcm8030339] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 03/04/2019] [Accepted: 03/07/2019] [Indexed: 12/25/2022] Open
Abstract
The main goals of this work were to assess whether the topical administration of glucagon-like peptide-1 (GLP-1) could revert the impairment of the neurovascular unit induced by long-term diabetes (24 weeks) in diabetic mice and to look into the underlying mechanisms. For that reason, db/db mice were treated with eye drops of GLP-1 or vehicle for 3 weeks. Moreover, db/+ mice were used as control. Studies performed in vivo included electroretinogramand the assessment of vascular leakage by using Evans Blue. NF-κB, GFAP and Ki67 proteins were analyzed by immunofluorescence (IF). Additionally, caspase 9, AMPK, IKBα, NF-κB, AKT, GSK3, β-catenin, Bcl-xl, and VEGF were analyzed by WB. Finally, VEGF, IL-1β, IL-6, TNF-α, IL-18, and NLRP3 were studied by reverse transcription-polymerase chain reaction (RT-PCR) and immunofluorescence. We found that topical administration of GLP-1 reverted reactive gliosis and albumin extravasation, and protected against apoptosis and retinal dysfunction. Regarding the involved mechanisms, GLP-1 exerted an anti-inflammatory action by decreasing NF-κB, inflammosome, and pro-inflammatory factors. In addition, it also decreased VEGF expression. Furthermore, GLP-1 promoted cell survival by increasing the anti-apoptotic protein Bcl-xl and the signaling pathway Akt/GSK3b/β-catenin. Finally, Ki67 results revealed that GLP-1 treatment could induce neurogenesis. In conclusion, the topical administration of GLP-1 reverts the impairment of the neurovascular unit by modulating essential pathways involved in the development of diabetic retinopathy (DR). These beneficial effects on the neurovascular unit could pave the way for clinical trials addressed to confirm the effectiveness of GLP-1 in early stages of DR.
Collapse
|
27
|
Liraglutide and its Neuroprotective Properties-Focus on Possible Biochemical Mechanisms in Alzheimer's Disease and Cerebral Ischemic Events. Int J Mol Sci 2019; 20:ijms20051050. [PMID: 30823403 PMCID: PMC6429395 DOI: 10.3390/ijms20051050] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 02/24/2019] [Accepted: 02/25/2019] [Indexed: 12/28/2022] Open
Abstract
Liraglutide is a GLP-1 analog (glucagon like peptide-1) used primarily in the treatment of diabetes mellitus type 2 (DM2) and obesity. The literature starts to suggest that liraglutide may reduce the effects of ischemic stroke by activating anti-apoptotic pathways, as well as limiting the harmful effects of free radicals. The GLP-1R expression has been reported in the cerebral cortex, especially occipital and frontal lobes, the hypothalamus, and the thalamus. Liraglutide reduced the area of ischemia caused by MCAO (middle cerebral artery occlusion), limited neurological deficits, decreased hyperglycemia caused by stress, and presented anti-apoptotic effects by increasing the expression of Bcl-2 and Bcl-xl proteins and reduction of Bax and Bad protein expression. The pharmaceutical managed to decrease concentrations of proapoptotic factors, such as NF-κB (Nuclear Factor-kappa β), ICAM-1 (Intercellular Adhesion Molecule 1), caspase-3, and reduced the level of TUNEL-positive cells. Liraglutide was able to reduce the level of free radicals by decreasing the level of malondialdehyde (MDA), and increasing the superoxide dismutase level (SOD), glutathione (GSH), and catalase. Liraglutide may affect the neurovascular unit causing its remodeling, which seems to be crucial for recovery after stroke. Liraglutide may stabilize atherosclerotic plaque, as well as counteract its early formation and further development. Liraglutide, through its binding to GLP-1R (glucagon like peptide-1 receptor) and consequent activation of PI3K/MAPK (Phosphoinositide 3-kinase/mitogen associated protein kinase) dependent pathways, may have a positive impact on Aβ (amyloid beta) trafficking and clearance by increasing the presence of Aβ transporters in cerebrospinal fluid. Liraglutide seems to affect tau pathology. It is possible that liraglutide may have some stem cell stimulating properties. The effects may be connected with PKA (phosphorylase kinase A) activation. This paper presents potential mechanisms of liraglutide activity in conditions connected with neuronal damage, with special emphasis on Alzheimer's disease and cerebral ischemia.
Collapse
|
28
|
Zafar S, Sachdeva M, Frankfort BJ, Channa R. Retinal Neurodegeneration as an Early Manifestation of Diabetic Eye Disease and Potential Neuroprotective Therapies. Curr Diab Rep 2019; 19:17. [PMID: 30806815 PMCID: PMC7192364 DOI: 10.1007/s11892-019-1134-5] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
PURPOSE OF REVIEW Diabetic retinopathy (DR) is a major cause of visual impairment and blindness throughout the world. Microvascular changes have long been regarded central to disease pathogenesis. In recent years, however, retinal neurodegeneration is increasingly being hypothesized to occur prior to the vascular changes classically associated with DR and contribute to disease pathogenesis. RECENT FINDINGS There is growing structural and functional evidence from human and animal studies that suggests retinal neurodegeneration to be an early component of DR. Identification of new therapeutic targets is an ongoing area of research with several different molecules undergoing testing in animal models for their neuroprotective properties and for possible use in humans. Retinal neurodegeneration may play a central role in DR pathogenesis. As new therapies are developed, it will be important to develop criteria for clinically defining retinal neurodegeneration. A standardization of the methods for monitoring neurodegeneration along with more sensitive means of detecting preclinical damage is also needed.
Collapse
Affiliation(s)
- Sidra Zafar
- Wilmer Eye Institute, Johns Hopkins Hospital, Baltimore, MD 21287, USA
| | - Mira Sachdeva
- Wilmer Eye Institute, Johns Hopkins Hospital, Baltimore, MD 21287, USA
| | | | - Roomasa Channa
- Wilmer Eye Institute, Johns Hopkins Hospital, Baltimore, MD 21287, USA
- Department of Ophthalmology, Baylor College of Medicine, Houston, TX, USA
| |
Collapse
|
29
|
Biocompatibility and safety of insulin-loaded chitosan nanoparticles/ PLGA-PEG-PLGA hydrogel (ICNPH) delivered by subconjunctival injection in rats. J Drug Deliv Sci Technol 2019. [DOI: 10.1016/j.jddst.2018.12.032] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
|
30
|
Tarchick MJ, Cutler AH, Trobenter TD, Kozlowski MR, Makowski ER, Holoman N, Shao J, Shen B, Anand-Apte B, Samuels IS. Endogenous insulin signaling in the RPE contributes to the maintenance of rod photoreceptor function in diabetes. Exp Eye Res 2018; 180:63-74. [PMID: 30543793 DOI: 10.1016/j.exer.2018.11.020] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 11/19/2018] [Accepted: 11/20/2018] [Indexed: 01/01/2023]
Abstract
In diabetes, there are two major physiological aberrations: (i) Loss of insulin signaling due to absence of insulin (type 1 diabetes) or insulin resistance (type 2 diabetes) and (ii) increased blood glucose levels. The retina has a high proclivity to damage following diabetes, and much of the pathology seen in diabetic retinopathy has been ascribed to hyperglycemia and downstream cascades activated by increased blood glucose. However, less attention has been focused on the direct role of insulin on retinal physiology, likely due to the fact that uptake of glucose in retinal cells is not insulin-dependent. The retinal pigment epithelium (RPE) is instrumental in maintaining the structural and functional integrity of the retina. Recent studies have suggested that RPE dysfunction is a precursor of, and contributes to, the development of diabetic retinopathy. To evaluate the role of insulin on RPE cell function directly, we generated a RPE specific insulin receptor (IR) knockout (RPEIRKO) mouse using the Cre-loxP system. Using this mouse, we sought to determine the impact of insulin-mediated signaling in the RPE on retinal function under physiological control conditions as well as in streptozotocin (STZ)-induced diabetes. We demonstrate that loss of RPE-specific IR expression resulted in lower a- and b-wave electroretinogram amplitudes in diabetic mice as compared to diabetic mice that expressed IR on the RPE. Interestingly, RPEIRKO mice did not exhibit significant differences in the amplitude of the RPE-dependent electroretinogram c-wave as compared to diabetic controls. However, loss of IR-mediated signaling in the RPE reduced levels of reactive oxygen species and the expression of pro-inflammatory cytokines in the retina of diabetic mice. These results imply that IR-mediated signaling in the RPE regulates photoreceptor function and may play a role in the generation of oxidative stress and inflammation in the retina in diabetes.
Collapse
Affiliation(s)
- Matthew J Tarchick
- Research Service, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA; Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Alecia H Cutler
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Timothy D Trobenter
- Research Service, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA; Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Michael R Kozlowski
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Emily R Makowski
- Research Service, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA; Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Nicholas Holoman
- Research Service, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA; Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Jianning Shao
- Cleveland Clinic Lerner College of Medicine at Case Western Reserve University, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Bailey Shen
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Bela Anand-Apte
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, OH, USA; Department of Molecular Medicine, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, USA
| | - Ivy S Samuels
- Research Service, Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA; Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, OH, USA.
| |
Collapse
|
31
|
Pereiro X, Ruzafa N, Acera A, Fonollosa A, Rodriguez FD, Vecino E. Dexamethasone protects retinal ganglion cells but not Müller glia against hyperglycemia in vitro. PLoS One 2018; 13:e0207913. [PMID: 30475883 PMCID: PMC6258116 DOI: 10.1371/journal.pone.0207913] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 11/08/2018] [Indexed: 12/21/2022] Open
Abstract
Diabetic retinopathy (DR) is a common complication of diabetes, for which hyperglycemia is a major etiological factor. It is known that retinal glia (Müller cells) and retinal ganglion cells (RGCs) are affected by diabetes, and there is evidence that DR is associated with neural degeneration. Dexamethasone is a glucocorticoid used to treat many inflammatory and autoimmune conditions, including several eye diseases like DR. Thus, our goal was to study the effect of dexamethasone on the survival of RGCs and Müller glial cells isolated from rat retinas and maintained in vitro under hyperglycemic conditions. The behavior of primary RGC cell cultures, and of mixed RGC and Müller cell co-cultures, was studied in hyperglycemic conditions (30 mM glucose), both in the presence and absence of Dexamethasone (1 μM). RGC and Müller cell survival was evaluated, and the conditioned media of these cultures was collected to quantify the inflammatory cytokines secreted by these cells using a multiplex assay. The role of IL-1β, IL-6 and TNFα in RGC death was also evaluated by adding these cytokines to the co-cultures. RGC survival decreased significantly when these cells were grown in high glucose conditions, reaching 54% survival when they were grown alone and only 33% when co-cultured with Müller glia. The analysis of the cytokines in the conditioned media revealed an increase in IL-1β, IL-6 and TNFα under hyperglycemic conditions, which reverted to the basal concentration in co-cultures maintained in the presence of dexamethasone. Finally, when these cytokines were added to co-cultures they appeared to have a direct effect on RGC survival. Hence, these cytokines could be implicated in the death of RGCs when glucose concentrations increase and dexamethasone might protect RGCs from the cell death induced in these conditions.
Collapse
Affiliation(s)
- Xandra Pereiro
- Department of Cell Biology and Histology, University of Basque Country UPV/EHU, Leioa, Vizcaya, Spain
- * E-mail:
| | - Noelia Ruzafa
- Department of Cell Biology and Histology, University of Basque Country UPV/EHU, Leioa, Vizcaya, Spain
| | - Arantxa Acera
- Department of Cell Biology and Histology, University of Basque Country UPV/EHU, Leioa, Vizcaya, Spain
| | - Alex Fonollosa
- Servicio Oftalmología Hospital de Cruces, BioCruces, Barakaldo, Vizcaya, Spain
| | - F. David Rodriguez
- Department of Biochemistry and Molecular Biology, University of Salamanca, Salamanca, Spain
| | - Elena Vecino
- Department of Cell Biology and Histology, University of Basque Country UPV/EHU, Leioa, Vizcaya, Spain
| |
Collapse
|
32
|
Lázár BA, Jancsó G, Pálvölgyi L, Dobos I, Nagy I, Sántha P. Insulin Confers Differing Effects on Neurite Outgrowth in Separate Populations of Cultured Dorsal Root Ganglion Neurons: The Role of the Insulin Receptor. Front Neurosci 2018; 12:732. [PMID: 30364236 PMCID: PMC6191510 DOI: 10.3389/fnins.2018.00732] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2018] [Accepted: 09/24/2018] [Indexed: 01/04/2023] Open
Abstract
Apart from its pivotal role in the regulation of carbohydrate metabolism, insulin exerts important neurotrophic and neuromodulator effects on dorsal root ganglion (DRG) neurons. The neurite outgrowth-promoting effect is one of the salient features of insulin's action on cultured DRG neurons. Although it has been established that a significant population of DRG neurons express the insulin receptor (InsR), the significance of InsR expression and the chemical phenotype of DRG neurons in relation to the neurite outgrowth-promoting effect of insulin has not been studied. Therefore, in this study by using immunohistochemical and quantitative stereological methods we evaluated the effect of insulin on neurite outgrowth of DRG neurons of different chemical phenotypes which express or lack the InsR. Insulin, at a concentration of 10 nM, significantly increased total neurite length, the length of the longest neurite and the number of branch points of cultured DRG neurons as compared to neurons cultured in control medium or in the presence of 1 μM insulin. In both the control and the insulin exposed cultures, ∼43% of neurons displayed InsR-immunoreactivity. The proportions of transient receptor potential vanilloid type 1 receptor (TRPV1)-immunoreactive (IR), calcitonin gene-related peptide (CGRP)-IR and Bandeiraea simplicifolia isolectin B4 (IB4)-binding neurons amounted to ∼61%, ∼57%, and ∼31% of DRG neurons IR for the InsR. Of the IB4-positive population only neurons expressing the InsR were responsive to insulin. In contrast, TRPV1-IR nociceptive and CGRP-IR peptidergic neurons showed increased tendency for neurite outgrowth which was further enhanced by insulin. However, the responsiveness of DRG neurons expressing the InsR was superior to populations of DRG neurons which lack this receptor. The findings also revealed that besides the expression of the InsR, inherent properties of peptidergic, but not non-peptidergic nociceptive neurons may also significantly contribute to the mechanisms of neurite outgrowth of DRG neurons. These observations suggest distinct regenerative propensity for differing populations of DRG neurons which is significantly affected through insulin receptor signaling.
Collapse
Affiliation(s)
- Bence András Lázár
- Department of Psychiatry, Faculty of Medicine, University of Szeged, Szeged, Hungary.,Department of Physiology, University of Szeged, Szeged, Hungary
| | - Gábor Jancsó
- Department of Physiology, University of Szeged, Szeged, Hungary
| | - Laura Pálvölgyi
- Department of Physiology, University of Szeged, Szeged, Hungary
| | - Ildikó Dobos
- Department of Physiology, University of Szeged, Szeged, Hungary
| | - István Nagy
- Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Péter Sántha
- Department of Physiology, University of Szeged, Szeged, Hungary
| |
Collapse
|
33
|
Rotermund C, Machetanz G, Fitzgerald JC. The Therapeutic Potential of Metformin in Neurodegenerative Diseases. Front Endocrinol (Lausanne) 2018; 9:400. [PMID: 30072954 PMCID: PMC6060268 DOI: 10.3389/fendo.2018.00400] [Citation(s) in RCA: 194] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 06/27/2018] [Indexed: 12/12/2022] Open
Abstract
The search for treatments for neurodegenerative diseases is a major concern in light of today's aging population and an increasing burden on individuals, families, and society. Although great advances have been made in the last decades to understand the underlying genetic and biological cause of these diseases, only some symptomatic treatments are available. Metformin has long since been used to treat Type 2 Diabetes and has been shown to be beneficial in several other conditions. Metformin is well-tested in vitro and in vivo and an approved compound that targets diverse pathways including mitochondrial energy production and insulin signaling. There is growing evidence for the benefits of metformin to counteract age-related diseases such as cancer, cardiovascular disease, and neurodegenerative diseases. We will discuss evidence showing that certain neurodegenerative diseases and diabetes are explicitly linked and that metformin along with other diabetes drugs can reduce neurological symptoms in some patients and reduce disease phenotypes in animal and cell models. An interesting therapeutic factor might be how metformin is able to balance survival and death signaling in cells through pathways that are commonly associated with neurodegenerative diseases. In healthy neurons, these overarching signals keep energy metabolism, oxidative stress, and proteostasis in check, avoiding the dysfunction and neuronal death that defines neurodegenerative disease. We will discuss the biological mechanisms involved and the relevance of neuronal vulnerability and potential difficulties for future trials and development of therapies.
Collapse
Affiliation(s)
| | - Gerrit Machetanz
- Department of Neurodegenerative Diseases, Centre of Neurology and Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Julia C. Fitzgerald
- German Centre for Neurodegenerative Diseases, Tübingen, Germany
- Department of Neurodegenerative Diseases, Centre of Neurology and Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| |
Collapse
|
34
|
Rotermund C, Machetanz G, Fitzgerald JC. The Therapeutic Potential of Metformin in Neurodegenerative Diseases. Front Endocrinol (Lausanne) 2018; 9:400. [PMID: 30072954 DOI: 10.3389/fendo.2018.00400/xml/nlm] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 06/27/2018] [Indexed: 05/25/2023] Open
Abstract
The search for treatments for neurodegenerative diseases is a major concern in light of today's aging population and an increasing burden on individuals, families, and society. Although great advances have been made in the last decades to understand the underlying genetic and biological cause of these diseases, only some symptomatic treatments are available. Metformin has long since been used to treat Type 2 Diabetes and has been shown to be beneficial in several other conditions. Metformin is well-tested in vitro and in vivo and an approved compound that targets diverse pathways including mitochondrial energy production and insulin signaling. There is growing evidence for the benefits of metformin to counteract age-related diseases such as cancer, cardiovascular disease, and neurodegenerative diseases. We will discuss evidence showing that certain neurodegenerative diseases and diabetes are explicitly linked and that metformin along with other diabetes drugs can reduce neurological symptoms in some patients and reduce disease phenotypes in animal and cell models. An interesting therapeutic factor might be how metformin is able to balance survival and death signaling in cells through pathways that are commonly associated with neurodegenerative diseases. In healthy neurons, these overarching signals keep energy metabolism, oxidative stress, and proteostasis in check, avoiding the dysfunction and neuronal death that defines neurodegenerative disease. We will discuss the biological mechanisms involved and the relevance of neuronal vulnerability and potential difficulties for future trials and development of therapies.
Collapse
Affiliation(s)
| | - Gerrit Machetanz
- Department of Neurodegenerative Diseases, Centre of Neurology and Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Julia C Fitzgerald
- German Centre for Neurodegenerative Diseases, Tübingen, Germany
- Department of Neurodegenerative Diseases, Centre of Neurology and Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| |
Collapse
|
35
|
Role of neuritin in retinal ganglion cell death in adult mice following optic nerve injury. Sci Rep 2018; 8:10132. [PMID: 29973613 PMCID: PMC6031618 DOI: 10.1038/s41598-018-28425-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 06/21/2018] [Indexed: 12/31/2022] Open
Abstract
Neuritin is a small extracellular protein that plays important roles in the process of neural development, synaptic plasticity, and neural cell survival. Here we investigated the function of neuritin in a mouse model of optic nerve injury (ONI). ONI induced upregulation of neuritin mRNA in the retina of WT mice. The retinal structure and the number of retinal ganglion cells (RGCs) were normal in adult neuritin knockout (KO) mice. In vivo retinal imaging and histopathological analyses demonstrated that RGC death and inner retinal degeneration following ONI were more severe in neuritin KO mice. Immunoblot analyses revealed that ONI-induced phosphorylation of Akt and ERK were suppressed in neuritin KO mice. Our findings suggest that neuritin has neuroprotective effects following ONI and may be useful for treatment of posttraumatic complication.
Collapse
|
36
|
Lázár BA, Jancsó G, Nagy I, Horváth V, Sántha P. The insulin receptor is differentially expressed in somatic and visceral primary sensory neurons. Cell Tissue Res 2018; 374:243-249. [PMID: 29955950 DOI: 10.1007/s00441-018-2868-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 06/04/2018] [Indexed: 10/28/2022]
Abstract
Recent studies demonstrated the expression of the insulin receptor (InsR) and its functional interaction with the transient receptor potential vanilloid type 1 receptor (TRPV1) in primary sensory neurons (PSNs). The present study was undertaken to reveal the target-specific expression of the InsR and its co-localization with the TRPV1 in rat PSNs. We assessed the localization of the InsR and its co-localization with the TRPV1 in PSNs retrogradely labelled with biotin-conjugated wheat germ agglutinin injected into the dorsal hind paw skin, the gastrocnemius muscle, the pancreas and the urinary bladder wall. The largest proportions of retrogradely labelled InsR-immunoreactive neurons were identified among PSNs serving the pancreas (~ 54%) and the urinary bladder (~ 53%). The proportions of retrogradely labelled InsR-immunoreactive neurons innervating the dorsal hind paw skin and the gastrocnemius muscle amounted to ~ 22 and ~ 21%. TRPV1-immunoreactive neurons amounted to ~ 63, ~ 62, ~ 67 and ~ 65% of retrogradely labelled cutaneous, muscle, pancreatic and urinary bladder PSNs, respectively. Co-localization of the TRPV1 with the InsR was observed in ~ 16, ~ 15, ~ 29 and ~ 30% of retrogradely labelled cutaneous, muscle, pancreatic and urinary bladder PSNs. These quantitative immunohistochemical data demonstrate a preponderance of InsR-immunoreactivity among PSNs, which innervate visceral targets. The present findings suggest that visceral spinal PSNs are more likely to be exposed to the modulatory effects of insulin on sensory functions, including neurotrophic, nociceptive and inflammatory processes.
Collapse
Affiliation(s)
- Bence András Lázár
- Department of Psychiatry, University of Szeged, Kálvária sugárút 57, Szeged, H-6725, Hungary. .,Department of Physiology, University of Szeged, Szeged, Hungary.
| | - Gábor Jancsó
- Department of Physiology, University of Szeged, Szeged, Hungary
| | - István Nagy
- Department of Surgery and Cancer, Imperial College London, London, UK
| | - Viktor Horváth
- First Department of Internal Medicine, Semmelweis University, Budapest, Hungary
| | - Péter Sántha
- Department of Physiology, University of Szeged, Szeged, Hungary
| |
Collapse
|
37
|
Acuity and colour vision changes post intravitreal dexamethasone implant injection in patients with diabetic macular oedema. PLoS One 2018; 13:e0199693. [PMID: 29944702 PMCID: PMC6019681 DOI: 10.1371/journal.pone.0199693] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 06/11/2018] [Indexed: 11/19/2022] Open
Abstract
Purpose To evaluate changes in colour vision following intravitreal injection of Dexamethasone implant (Ozurdex) in patients with diabetic macular oedema (DMO). Both red-green (RG) and yellow-blue (YB) chromatic sensitivity were assessed using the Colour Assessment & Diagnosis (CAD) test which isolates the use of colour signals and provides age-corrected, statistical limits for normal trichromats. To determine whether colour changes and visual acuity (VA) post-treatment relate to central sub-field retinal thickness (CST). Methods Fourteen patients with DMO who were undergoing treatment with Ozurdex were recruited for this study. RG and YB colour thresholds were measured using the CAD test, best corrected visual acuity was assessed using the ETDRS chart and CST was measured using spectral domain optical coherence tomography (SD-OCT). All tests were performed monocularly at baseline and 24 weeks post injection. Results All patients (n = 14 eyes), had significant loss of RG and YB chromatic sensitivity at baseline (p<0.05). The mean age was 56 ± 9.5 years. The age specific, monocular, upper normal limits for a 56 year old subject are 2.66 for RG and 2.85 for YB. In this study, the measured, pre injection thresholds (mean±SD) were 22.6 ± 11.3 for RG and 16.2 ± 3.76 for YB. There was significant improvement in RG threshold post injection (i.e., 19.2 ± 10.8 (p<0.05)). No significant changes were found in the YB thresholds with corresponding mean and range values of: 15.8 ± 4.6 (p = 0.23). CST pre-treatment was 542 ±135 μm. After treatment and by week 24 the CST values decreased to 435 ±127 μm. Conclusions RG colour thresholds provide a sensitive measure of functional change in diabetic subjects with macular oedema. The YB system is damaged severely in the DMO patients studied and shows little or no recovery post treatment. The improvement in VA and particularly in RG colour vision correlate well with the measured decrease in CST. The results suggest that the improvement in the RG chromatic sensitivity can provide a useful biomarker for monitoring the efficacy of treatment in DMO.
Collapse
|
38
|
Dai W, Miller WP, Toro AL, Black AJ, Dierschke SK, Feehan RP, Kimball SR, Dennis MD. Deletion of the stress-response protein REDD1 promotes ceramide-induced retinal cell death and JNK activation. FASEB J 2018; 32:fj201800413RR. [PMID: 29920218 PMCID: PMC6219834 DOI: 10.1096/fj.201800413rr] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The role of dyslipidemia in the development of retinal dysfunction remains poorly understood. Using an animal model of diet-induced obesity/pre-type 2 diabetes, we investigated molecular defects in the retina arising from consumption of a diet high in saturated fats and sugars ( i.e., a Western diet). We found that feeding mice a Western diet increased the abundance of retinal sphingolipids, attenuated protein kinase B (Akt) phosphorylation, enhanced JNK activation, and increased retinal cell death. When we used palmitate or C6-ceramide (Cer) to assess sphingolipid-mediated signaling in cultured murine and human cells, we observed similar effects on Akt, JNK, and cell death. Furthermore, both Western diet and C6-Cer exposure enhanced expression of the stress-response protein regulated in development and DNA damage response 1 (REDD1) and loss of REDD1 increased C6-Cer-induced JNK activation and cell death. Exogenous REDD1 expression repressed JNK-mediated phosphorylation in cultured cells. We found that thioredoxin-interacting protein (TXNIP) expression was elevated in REDD1-deficient cell lines and C6-Cer promoted TXNIP expression in both wild-type and REDD1-deficient cells. Likewise, TXNIP knockdown attenuated JNK activation and caspase 3 cleavage after either C6-Cer exposure or REDD1 deletion. The results support a model wherein Cer-induced REDD1 expression attenuates TXNIP-dependent JNK activation and retinal cell death.-Dai, W., Miller, W. P., Toro, A. L., Black, A. J., Dierschke, S. K., Feehan, R. P., Kimball, S. R., Dennis, M. D. Deletion of the stress-response protein REDD1 promotes ceramide-induced retinal cell death and JNK activation.
Collapse
Affiliation(s)
- Weiwei Dai
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, Pennsylvania, USA
| | - William P Miller
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, Pennsylvania, USA
| | - Allyson L Toro
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, Pennsylvania, USA
| | - Adam J Black
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, Pennsylvania, USA
| | - Sadie K Dierschke
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, Pennsylvania, USA
| | - Robert P Feehan
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, Pennsylvania, USA
| | - Scot R Kimball
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, Pennsylvania, USA
| | - Michael D Dennis
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, Pennsylvania, USA
| |
Collapse
|
39
|
Mishra N, Lata S, Deshmukh P, Kamat K, Surolia A, Banerjee T. Insulin signaling pathway protects neuronal cell lines by Sirt3 mediated IRS2 activation. Biofactors 2018; 44:224-236. [PMID: 29411439 DOI: 10.1002/biof.1413] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 12/28/2017] [Accepted: 01/05/2018] [Indexed: 01/15/2023]
Abstract
Cellular stress like ER and oxidative stress are the principle causative agents of various proteinopathies. Multifunctional protein PARK7/DJ-1 provides protection against cellular stress. Recently, insulin/IGF also has emerged as a neuro-protective molecule. However, it is not known whether DJ-1 and insulin/IGF complement each other for cellular protection in response to stress. In this study, we show for the first time, that in human and mouse neuronal cell lines, down regulation of DJ-1 for 48 h leads to compensatory upregulation of insulin/IGF signaling (IIS) pathway genes, namely, insulin receptor, insulin receptor substrate, and Akt under normal physiological conditions as well as in cellular stress conditions. Moreover, upon exogenous supply of insulin there is a marked increase in the IIS components both at gene and protein levels leading to down regulation and inactivation of GSK3β. By immunoprecipitation, it was observed that Sirt3 mediated deacetylation and activation of FoxO3a could not occur under DJ-1 downregulation. Transient DJ-1 downregulation also led to Akt mediated increased phosphorylation and nuclear exclusion of FoxO3a. When DJ-1 was downregulated increased interaction of Sirt3 with IRS2 was observed leading to its activation resulting in IIS upregulation. Thus, transient downregulation of DJ-1 leads to stimulation of IIS pathway by Sirt3 mediated IRS2 activation. Consequently, antiapoptotic program is triggered in neuronal cells via Akt-GSK3β-FoxO3a axis. © 2018 BioFactors, 44(3):224-236, 2018.
Collapse
Affiliation(s)
- Neha Mishra
- Department of Biotechnology, Savitribai Phule Pune University (Former Pune University), Ganeshkhind Road, Pune, Maharashtra 411007, India
| | - Sonam Lata
- Department of Biotechnology, Savitribai Phule Pune University (Former Pune University), Ganeshkhind Road, Pune, Maharashtra 411007, India
| | - Priyanka Deshmukh
- Department of Biotechnology, Savitribai Phule Pune University (Former Pune University), Ganeshkhind Road, Pune, Maharashtra 411007, India
| | - Kajal Kamat
- Department of Biotechnology, Savitribai Phule Pune University (Former Pune University), Ganeshkhind Road, Pune, Maharashtra 411007, India
| | - Avadhesha Surolia
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, India
| | - Tanushree Banerjee
- Department of Biotechnology, Savitribai Phule Pune University (Former Pune University), Ganeshkhind Road, Pune, Maharashtra 411007, India
| |
Collapse
|
40
|
Rübsam A, Parikh S, Fort PE. Role of Inflammation in Diabetic Retinopathy. Int J Mol Sci 2018; 19:ijms19040942. [PMID: 29565290 PMCID: PMC5979417 DOI: 10.3390/ijms19040942] [Citation(s) in RCA: 450] [Impact Index Per Article: 75.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 03/09/2018] [Accepted: 03/17/2018] [Indexed: 02/07/2023] Open
Abstract
Diabetic retinopathy is a common complication of diabetes and remains the leading cause of blindness among the working-age population. For decades, diabetic retinopathy was considered only a microvascular complication, but the retinal microvasculature is intimately associated with and governed by neurons and glia, which are affected even prior to clinically detectable vascular lesions. While progress has been made to improve the vascular alterations, there is still no treatment to counteract the early neuro-glial perturbations in diabetic retinopathy. Diabetes is a complex metabolic disorder, characterized by chronic hyperglycemia along with dyslipidemia, hypoinsulinemia and hypertension. Increasing evidence points to inflammation as one key player in diabetes-associated retinal perturbations, however, the exact underlying molecular mechanisms are not yet fully understood. Interlinked molecular pathways, such as oxidative stress, formation of advanced glycation end-products and increased expression of vascular endothelial growth factor have received a lot of attention as they all contribute to the inflammatory response. In the current review, we focus on the involvement of inflammation in the pathophysiology of diabetic retinopathy with special emphasis on the functional relationships between glial cells and neurons. Finally, we summarize recent advances using novel targets to inhibit inflammation in diabetic retinopathy.
Collapse
Affiliation(s)
- Anne Rübsam
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA.
| | - Sonia Parikh
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA.
| | - Patrice E Fort
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA.
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48105, USA.
| |
Collapse
|
41
|
Sorrentino P, Nieboer D, Twisk JWR, Stam CJ, Douw L, Hillebrand A. The Hierarchy of Brain Networks Is Related to Insulin Growth Factor-1 in a Large, Middle-Aged, Healthy Cohort: An Exploratory Magnetoencephalography Study. Brain Connect 2018; 7:321-330. [PMID: 28520468 DOI: 10.1089/brain.2016.0469] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Recently, a large study demonstrated that lower serum levels of insulin growth factor-1 (IGF-1) relate to brain atrophy and to a greater risk for developing Alzheimer's disease in a healthy elderly population. We set out to test if functional brain networks relate to IGF-1 levels in the middle aged. Hence, we studied the association between IGF-1 and magnetoencephalography-based functional network characteristics in a middle-aged population. The functional connections between brain areas were estimated for six frequency bands (delta, theta, alpha1, alpha2, beta, gamma) using the phase lag index. Subsequently, the topology of the frequency-specific functional networks was characterized using the minimum spanning tree. Our results showed that lower levels of serum IGF-1 relate to a globally less integrated functional network in the beta and theta band. The associations remained significant when correcting for gender and systemic effects of IGF-1 that might indirectly affect the brain. The value of this exploratory study is the demonstration that lower levels of IGF-1 are associated with brain network topology in the middle aged.
Collapse
Affiliation(s)
- Pierpaolo Sorrentino
- 1 Department of Clinical Neurophysiology and MEG Center, VU University Medical Center , Amsterdam, The Netherlands .,2 Istituto di Diagnosi e Cura Hermitage Capodimonte , Naples, Italy
| | - Dagmar Nieboer
- 3 Department of Methodology and Applied Biostatistics, Faculty of Earth and Life Sciences, VU University Amsterdam , Amsterdam, The Netherlands
| | - Jos W R Twisk
- 4 Department of Epidemiology and Biostatistics, VU University Medical Center , Amsterdam, The Netherlands
| | - Cornelis J Stam
- 1 Department of Clinical Neurophysiology and MEG Center, VU University Medical Center , Amsterdam, The Netherlands
| | - Linda Douw
- 5 Department of Anatomy and Neurosciences, VU University Medical Center , Amsterdam, The Netherlands .,6 Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging/Massachusetts General Hospital , Boston, Massachusetts
| | - Arjan Hillebrand
- 1 Department of Clinical Neurophysiology and MEG Center, VU University Medical Center , Amsterdam, The Netherlands
| |
Collapse
|
42
|
Rosa AP, Mescka CP, Catarino FM, de Castro AL, Teixeira RB, Campos C, Baldo G, Graf DD, de Mattos-Dutra A, Dutra-Filho CS, da Rosa Araujo AS. Neonatal hyperglycemia induces cell death in the rat brain. Metab Brain Dis 2018; 33:333-342. [PMID: 29260360 DOI: 10.1007/s11011-017-0170-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2017] [Accepted: 12/11/2017] [Indexed: 02/06/2023]
Abstract
Several studies have examined neonatal diabetes, a rare disease characterized by hyperglycemia and low insulin levels that is usually diagnosed in the first 6 month of life. Recently, the effects of diabetes on the brain have received considerable attention. In addition, hyperglycemia may perturb brain function and might be associated with neuronal death in adult rats. However, few studies have investigated the damaging effects of neonatal hyperglycemia on the rat brain during central nervous system (CNS) development, particularly the mechanisms involved in the disease. Thus, in the present work, we investigated whether neonatal hyperglycemia induced by streptozotocin (STZ) promoted cell death and altered the levels of proteins involved in survival/death pathways in the rat brain. Cell death was assessed using FluoroJade C (FJC) staining and the expression of the p38 mitogen-activated protein kinase (p38), phosphorylated-c-Jun amino-terminal kinase (p-JNK), c-Jun amino-terminal kinase (JNK), protein kinase B (Akt), phosphorylated-protein kinase B (p-Akt), glycogen synthase kinase-3β (Gsk3β), B-cell lymphoma 2 (Bcl2) and Bcl2-associated X protein (Bax) protein were measured by Western blotting. The main results of this study showed that the metabolic alterations observed in diabetic rats (hyperglycemia and hypoinsulinemia) increased p38 expression and decreased p-Akt expression, suggesting that cell survival was altered and cell death was induced, which was confirmed by FJC staining. Therefore, the metabolic conditions observed during neonatal hyperglycemia may contribute to the harmful effect of diabetes on the CNS in a crucial phase of postnatal neuronal development.
Collapse
Affiliation(s)
- Andrea Pereira Rosa
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600 (Anexo), Porto Alegre, RS, 90035-003, Brazil.
| | - Caroline Paula Mescka
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Felipe Maciel Catarino
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600 (Anexo), Porto Alegre, RS, 90035-003, Brazil
| | - Alexandre Luz de Castro
- Programa de Pós-Graduação em Ciências Biológicas: Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Rayane Brinck Teixeira
- Programa de Pós-Graduação em Ciências Biológicas: Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Cristina Campos
- Programa de Pós-Graduação em Ciências Biológicas: Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Guilherme Baldo
- Programa de Pós-Graduação em Ciências Biológicas: Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Débora Dalmas Graf
- Departamento de Ciências Básicas da Saúde, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS, Brazil
| | - Angela de Mattos-Dutra
- Departamento de Ciências Básicas da Saúde, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS, Brazil
| | - Carlos Severo Dutra-Filho
- Programa de Pós-Graduação em Ciências Biológicas: Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600 (Anexo), Porto Alegre, RS, 90035-003, Brazil
| | - Alex Sander da Rosa Araujo
- Programa de Pós-Graduação em Ciências Biológicas: Fisiologia, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| |
Collapse
|
43
|
Miller WP, Yang C, Mihailescu ML, Moore JA, Dai W, Barber AJ, Dennis MD. Deletion of the Akt/mTORC1 Repressor REDD1 Prevents Visual Dysfunction in a Rodent Model of Type 1 Diabetes. Diabetes 2018; 67:110-119. [PMID: 29074598 PMCID: PMC5741149 DOI: 10.2337/db17-0728] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 10/20/2017] [Indexed: 12/25/2022]
Abstract
Diabetes-induced visual dysfunction is associated with significant neuroretinal cell death. The current study was designed to investigate the role of the Protein Regulated in Development and DNA Damage Response 1 (REDD1) in diabetes-induced retinal cell death and visual dysfunction. We recently demonstrated that REDD1 protein expression was elevated in response to hyperglycemia in the retina of diabetic rodents. REDD1 is an important regulator of Akt and mammalian target of rapamycin and as such plays a key role in neuronal function and survival. In R28 retinal cells in culture, hyperglycemic conditions enhanced REDD1 protein expression concomitant with caspase activation and cell death. By contrast, in REDD1-deficient R28 cells, neither hyperglycemic conditions nor the absence of insulin in culture medium were sufficient to promote cell death. In the retinas of streptozotocin-induced diabetic mice, retinal apoptosis was dramatically elevated compared with nondiabetic controls, whereas no difference was observed in diabetic and nondiabetic REDD1-deficient mice. Electroretinogram abnormalities observed in b-wave and oscillatory potentials of diabetic wild-type mice were also absent in REDD1-deficient mice. Moreover, diabetic wild-type mice exhibited functional deficiencies in visual acuity and contrast sensitivity, whereas diabetic REDD1-deficient mice had no visual dysfunction. The results support a role for REDD1 in diabetes-induced retinal neurodegeneration.
Collapse
Affiliation(s)
- William P Miller
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, PA
| | - Chen Yang
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, PA
| | - Maria L Mihailescu
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, PA
| | - Joshua A Moore
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, PA
| | - Weiwei Dai
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, PA
| | - Alistair J Barber
- Department of Ophthalmology, Penn State College of Medicine, Hershey, PA
| | - Michael D Dennis
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, PA
| |
Collapse
|
44
|
Liao R, Yan F, Zeng Z, Wang H, Qiu K, Xu J, Zheng W. Insulin-like growth factor-1 activates PI3K/Akt signalling to protect human retinal pigment epithelial cells from amiodarone-induced oxidative injury. Br J Pharmacol 2017; 175:125-139. [PMID: 29057462 DOI: 10.1111/bph.14078] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 10/11/2017] [Accepted: 10/13/2017] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND AND PURPOSE Amiodarone is one of the most effective anti-arrhythmic drugs available, but its clinical applications are limited by toxic side effects including optic toxicity. The purpose of this study was to investigate the toxic effect of amiodarone on D407 cells (a human retinal pigmented epithelial (RPE) cell line) and the mechanisms of the protective effect of insulin-like growth factor-1 (IGF-1). EXPERIMENTAL APPROACH The involvement of the kinases, Akt and ERK, was analysed by Western blot. Intracellular accumulation of ROS was measured using fluorophotometric quantification. A pharmacological approach with inhibitors was used to investigate the pathways involved in the protective action of IGF-1. KEY RESULTS Amiodarone concentration-dependently augmented the production of ROS, lipid peroxidation and apoptosis in D407 cells. IGF-1 time- and concentration-dependently reversed these effects of amiodarone and protected D407 cells from amiodarone-mediated toxicity. Amiodarone inhibited the pAkt but not pErk, and IGF-1 reversed this inhibitory effect of amiodarone. However, IGF-1 failed to suppress amiodarone-induced cytotoxicity in the presence of PI3K/Akt inhibitor LY294002 suggesting the direct involvement of the PI3K/Akt pathway. Furthermore, in vivo rat flash electroretinogram (FERG) recordings showed that IGF-1 reverses the amiodarone-induced decrease in a- and b-waves. The immunocytochemistry findings confirmed that vitreous IGF-1 injections promote the survival of RPE cells in rat retina treated with amiodarone. CONCLUSION AND IMPLICATIONS IGF-1 can protect RPE cells from amiodarone-mediated injury via the PI3K/Akt pathway in vivo and in vitro. IGF-1 has potential as a protective drug for the prevention and treatment of amiodarone-induced optic toxicity.
Collapse
Affiliation(s)
- Rifang Liao
- Faculty of Health Sciences, University of Macau, Taipa, Macau, and UM Zhuhai Research Institute, Zhuhai, China.,Department of Pharmacy, Sun Yat-Sen Memorial Hospital and the School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
| | - Fengxia Yan
- Faculty of Health Sciences, University of Macau, Taipa, Macau, and UM Zhuhai Research Institute, Zhuhai, China.,Department of Pharmacy, Sun Yat-Sen Memorial Hospital and the School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
| | - Zhuanping Zeng
- School of Public Health, Guangdong Pharmaceutical University, Guangzhou, China
| | - Haitao Wang
- Faculty of Health Sciences, University of Macau, Taipa, Macau, and UM Zhuhai Research Institute, Zhuhai, China.,School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Kaifeng Qiu
- Department of Pharmacy, Sun Yat-Sen Memorial Hospital and the School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
| | - Jinying Xu
- Faculty of Health Sciences, University of Macau, Taipa, Macau, and UM Zhuhai Research Institute, Zhuhai, China
| | - Wenhua Zheng
- Faculty of Health Sciences, University of Macau, Taipa, Macau, and UM Zhuhai Research Institute, Zhuhai, China.,Department of Pharmacy, Sun Yat-Sen Memorial Hospital and the School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou, China
| |
Collapse
|
45
|
Gao M, Guo KM, Wei YM, Ma MM, Cai JR, Xia TT, Ye QJ. Aspirin inhibits the proliferation of human uterine leiomyoma cells by downregulation of K‑Ras‑p110α interaction. Oncol Rep 2017; 38:2507-2517. [PMID: 28849118 DOI: 10.3892/or.2017.5915] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 08/14/2017] [Indexed: 11/06/2022] Open
Abstract
Aspirin has been confirmed as an effective antitumor drug in various cancers. However, the relationship between aspirin and uterine leiomyoma is still underexplored. Here, we explored the effects of aspirin on human uterine leiomyoma cells and provide insights into the underlying mechanisms. Cell Counting Kit-8 (CCK-8) and flow cytometry analysis showed that aspirin treatment inhibited cell proliferation and promoted cell cycle arrest at G0/G1 phase in a dose- and time‑dependent manner of human uterine leiomyoma cells. Further studies revealed that aspirin blocked the interaction between K-Ras and p110α by co-immunoprecipitation and immunofluorescence. Western blotting demonstrated K‑Ras‑p110α interaction was required for the effects of aspirin‑induced inhibition on cell growth and cell cycle transition via cell cycle regulators, including cyclin D1 and cyclin-dependent kinase 2 (CDK2). PI3K/Akt/caspase signaling pathway was involved in human uterine leiomyoma cell growth under aspirin treatment. Taken together, these results suggest that aspirin inhibited human uterine leiomyoma cell growth by regulating K‑Ras‑p110α interaction. Aspirin which targeting on interaction between K-Ras and p110α may serve as a new therapeutic drug for uterine leiomyoma treatment.
Collapse
Affiliation(s)
- Min Gao
- Department of Pharmacy, The Sixth Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong 510655, P.R. China
| | - Kai-Min Guo
- Department of Obstetrics and Gynecology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou, Guangdong 510623, P.R. China
| | - Ying-Mei Wei
- Department of Neurology, Sun Yat-sen Memorial Hospital of Sun Yat-sen University, Guangzhou, Guangdong 510120, P.R. China
| | - Ming-Ming Ma
- Department of Pharmacology, Cardiac and Cerebral Vascular Research Center, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, Guangdong 510080, P.R. China
| | - Jia-Rong Cai
- Department of Urology, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong 510630, P.R. China
| | - Ting-Ting Xia
- Department of Infertility, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong 510630, P.R. China
| | - Qing-Jian Ye
- Department of Gynecology, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong 510630, P.R. China
| |
Collapse
|
46
|
He H, Weir RL, Toutounchian JJ, Pagadala J, Steinle JJ, Baudry J, Miller DD, Yates CR. The quinic acid derivative KZ-41 prevents glucose-induced caspase-3 activation in retinal endothelial cells through an IGF-1 receptor dependent mechanism. PLoS One 2017; 12:e0180808. [PMID: 28796787 PMCID: PMC5552119 DOI: 10.1371/journal.pone.0180808] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 06/21/2017] [Indexed: 12/03/2022] Open
Abstract
Retinal microaneurysms, an early disease manifestation of diabetic retinopathy, are associated with retinal endothelial cell (REC) death and macular edema. We previously demonstrated that a quinic acid (QA) analog, KZ-41, promoted REC survival by blunting stress-induced p38 MAPK activation. Herein, we sought to expand our understanding of the pro-survival signal transduction pathways actuated by KZ-41. Using human RECs exposed to high glucose (25 mM, 72 hours), we demonstrated that KZ-41 blocks caspase-3 activation by triggering phosphorylation of the PI3K regulatory subunit (p85; Tyr458) and its downstream target Akt (Ser473). Akt signal transduction was accompanied by autophosphorylation of the receptor tyrosine kinase, insulin growth factor-1 receptor (IGF-1R). IGF-1R knockdown using either the tyrosine kinase inhibitor AG1024 or silencing RNA abolished KZ-41’s pro-survival effect. Under high glucose stress, caspase-3 activation correlated with elevated ERK1/2 phosphorylation and decreased insulin receptor substrate-1 (IRS-1) levels. KZ-41 decreased ERK1/2 phosphorylation and reversed the glucose-dependent reduction in IRS-1. To gain insight into the mechanistic basis for IGF-1R activation by KZ-41, we used molecular modeling and docking simulations to explore a possible protein:ligand interaction between the IGF-1R kinase domain and KZ-41. Computational investigations suggest two possible KZ-41 binding sites within the kinase domain: a region with high homology to the insulin receptor contains one potential allosteric binding site, and another potential site on the other side of the kinase domain, near the hinge domain. These data, together with previous proof-of-concept efficacy studies demonstrating KZ-41 mitigates pathologic retinal neovascularization in the murine oxygen-induced retinopathy model, suggests that QA derivatives may offer therapeutic benefit in ischemic retinopathies.
Collapse
Affiliation(s)
- Hui He
- Department of Pharmaceutical Sciences, UTHSC College of Pharmacy, Memphis, Tennessee, United States of America
| | - Rebecca L. Weir
- Biochemistry and Cellular and Molecular Biology, The University of Tennessee, Knoxville, Tennessee, United States of America
| | - Jordan J. Toutounchian
- Department of Pharmaceutical Sciences, UTHSC College of Pharmacy, Memphis, Tennessee, United States of America
| | - Jayaprakash Pagadala
- Department of Pharmaceutical Sciences, UTHSC College of Pharmacy, Memphis, Tennessee, United States of America
| | - Jena J. Steinle
- Department of Anatomy, Wayne State University, Detroit, Michigan, United States of America
| | - Jerome Baudry
- Biochemistry and Cellular and Molecular Biology, The University of Tennessee, Knoxville, Tennessee, United States of America
- UT/ORNL Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
| | - Duane D. Miller
- Department of Pharmaceutical Sciences, UTHSC College of Pharmacy, Memphis, Tennessee, United States of America
| | - Charles R. Yates
- Department of Pharmaceutical Sciences, UTHSC College of Pharmacy, Memphis, Tennessee, United States of America
- Department of Ophthalmology, UTHSC College of Medicine, Memphis, Tennessee, United States of America
- * E-mail:
| |
Collapse
|
47
|
Inman DM, Harun-Or-Rashid M. Metabolic Vulnerability in the Neurodegenerative Disease Glaucoma. Front Neurosci 2017; 11:146. [PMID: 28424571 PMCID: PMC5371671 DOI: 10.3389/fnins.2017.00146] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Accepted: 03/08/2017] [Indexed: 12/14/2022] Open
Abstract
Axons can be several orders of magnitude longer than neural somas, presenting logistical difficulties in cargo trafficking and structural maintenance. Keeping the axon compartment well supplied with energy also presents a considerable challenge; even seemingly subtle modifications of metabolism can result in functional deficits and degeneration. Axons require a great deal of energy, up to 70% of all energy used by a neuron, just to maintain the resting membrane potential. Axonal energy, in the form of ATP, is generated primarily through oxidative phosphorylation in the mitochondria. In addition, glial cells contribute metabolic intermediates to axons at moments of high activity or according to need. Recent evidence suggests energy disruption is an early contributor to pathology in a wide variety of neurodegenerative disorders characterized by axonopathy. However, the degree to which the energy disruption is intrinsic to the axon vs. associated glia is not clear. This paper will review the role of energy availability and utilization in axon degeneration in glaucoma, a chronic axonopathy of the retinal projection.
Collapse
Affiliation(s)
- Denise M Inman
- Department of Pharmaceutical Sciences, Northeast Ohio Medical UniversityRootstown, OH, USA
| | | |
Collapse
|
48
|
Yan D, Cai X, Feng Y. miR-183 Modulates Cell Apoptosis and Proliferation in Tongue Squamous Cell Carcinoma SCC25 Cell Line. Oncol Res 2017; 24:399-404. [PMID: 28281960 PMCID: PMC7838737 DOI: 10.3727/096504016x14685034103239] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
This study was designed to investigate the role of miR-183 in modulating cell growth and apoptosis of tongue squamous cell carcinoma SCC25 cell line. Human squamous epithelial cell and squamous cell carcinoma cell line SCC25 was used, and miR-183 was inhibited. Cell growth, colony formation, and apoptotic rate, as well as the expression of caspase 3 and BCL-xL, were detected. Results showed that miR-183 was significantly overexpressed in the SCC25 cell line when compared with normal control. The miR-183 inhibitor reduced cell growth and colony formation, while the apoptosis percentage was significantly increased. The expression of activated caspase 3 and BCL-xL was obviously up- and downregulated in siRNA-transfected cells, respectively. In conclusion, miR-183 contributed to cell growth and proliferation, and suppressed cell apoptosis in SCC25 cells. Therefore, miR-183 might serve as a therapeutic target in tongue squamous cell carcinoma (TSCC).
Collapse
Affiliation(s)
- Dayong Yan
- Oral and Maxillofacial Surgery, The Central Hospital of Zhengzhou, University of Zhengzhou, Zhengzhou, Henan, P.R. China
| | | | | |
Collapse
|
49
|
Arıkan S, Erşan İ, Eroğlu M, Yılmaz M, Tufan HA, Gencer B, Kara S, Aşık M. Does Retinal Neurodegeneration Seen in Diabetic Patients Begin in the Insulin Resistance Stage? Turk J Ophthalmol 2017; 46:264-269. [PMID: 28050322 PMCID: PMC5177782 DOI: 10.4274/tjo.68888] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 11/09/2015] [Indexed: 01/21/2023] Open
Abstract
OBJECTIVES To investigate whether retinal neurodegeneration and impairment in contrast sensitivity (CS), which have been demonstrated to begin in diabetic patients before the presence of signs of diabetic retinal vasculopathy, also occur in the stage of insulin resistance. MATERIALS AND METHODS The average, minimum and sectoral (inferior, superior, inferonasal, superonasal, inferotemporal and superotemporal) thicknesses of the ganglion cell-inner plexiform layer (GCIPL) measured using optical coherence tomography were compared between an insulin-resistant group and control group in order to evaluate the presence of retinal neurodegeneration. The CS of the two groups was also compared according to the logarithmic values measured at spatial frequencies of 1.5, 3, 6, 12 and 18 cycles per degree in photopic light using functional acuity contrast test (FACT). RESULTS Twenty-five eyes of 25 patients with insulin resistance (insulin resistant group) and 25 eyes of 25 healthy subjects (control group) were included in this study. There were no statistically significant differences between the two groups in any of the spatial frequencies in the FACT. The mean average GCIPL thickness and mean GCIPL thickness in the inferotemporal sector were significantly less in the insulin-resistant group when compared with the control group (mean average GCIPL thicknesses in the insulin-resistant and control groups were 83.6±4.7 µm and 86.7±3.7 µm respectively, p=0.01; mean inferotemporal GCIPL thicknesses in the insulin-resistant and control groups were 83±6.0 µm and 86.7±4.6 µm respectively, p=0.02). CONCLUSION Although it may not lead to functional visual impairment such as CS loss, the retinal neurodegeneration seen in diabetic patients may begin in the insulin resistance stage.
Collapse
Affiliation(s)
- Sedat Arıkan
- Çanakkale Onsekiz Mart University Faculty of Medicine, Department of Ophthalmology, Çanakkale, Turkey
| | - İsmail Erşan
- Çanakkale Onsekiz Mart University Faculty of Medicine, Department of Ophthalmology, Çanakkale, Turkey
| | - Mustafa Eroğlu
- Çanakkale Onsekiz Mart University Faculty of Medicine, Department of Endocrinology and Metabolism, Çanakkale, Turkey
| | - Mehmet Yılmaz
- Çanakkale Onsekiz Mart University Faculty of Medicine, Department of Ophthalmology, Çanakkale, Turkey
| | - Hasan Ali Tufan
- Çanakkale Onsekiz Mart University Faculty of Medicine, Department of Ophthalmology, Çanakkale, Turkey
| | - Baran Gencer
- Çanakkale Onsekiz Mart University Faculty of Medicine, Department of Ophthalmology, Çanakkale, Turkey
| | - Selçuk Kara
- Çanakkale Onsekiz Mart University Faculty of Medicine, Department of Ophthalmology, Çanakkale, Turkey
| | - Mehmet Aşık
- Çanakkale Onsekiz Mart University Faculty of Medicine, Department of Endocrinology and Metabolism, Çanakkale, Turkey
| |
Collapse
|
50
|
Kim SY, Jeong IW, Yang YS, Choi CW. Changes of the Individual Retinal Layer Thickness in Non-proliferative Diabetic Retinopathy in Type 2 Diabetes. JOURNAL OF THE KOREAN OPHTHALMOLOGICAL SOCIETY 2017. [DOI: 10.3341/jkos.2017.58.12.1376] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Sang Yeop Kim
- Department of Ophthalmology, Wonkwang University School of Medicine, Iksan, Korea
- Institute of Wonkwang Medical Science, Wonkwang University, Iksan, Korea
| | - Il Won Jeong
- Department of Ophthalmology, Wonkwang University School of Medicine, Iksan, Korea
- Institute of Wonkwang Medical Science, Wonkwang University, Iksan, Korea
| | - Yun Sik Yang
- Department of Ophthalmology, Wonkwang University School of Medicine, Iksan, Korea
- Institute of Wonkwang Medical Science, Wonkwang University, Iksan, Korea
| | - Chang Wook Choi
- Department of Ophthalmology, Wonkwang University School of Medicine, Iksan, Korea
- Institute of Wonkwang Medical Science, Wonkwang University, Iksan, Korea
| |
Collapse
|