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Chatterjee B, Fatima F, Seth S, Sinha Roy S. Moderate Elevation of Homocysteine Induces Endothelial Dysfunction through Adaptive UPR Activation and Metabolic Rewiring. Cells 2024; 13:214. [PMID: 38334606 PMCID: PMC10854856 DOI: 10.3390/cells13030214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 11/25/2023] [Indexed: 02/10/2024] Open
Abstract
Elevation of the intermediate amino acid metabolite Homocysteine (Hcy) causes Hyperhomocysteinemia (HHcy), a metabolic disorder frequently associated with mutations in the methionine-cysteine metabolic cycle as well as with nutritional deficiency and aging. The previous literature suggests that HHcy is a strong risk factor for cardiovascular diseases. Severe HHcy is well-established to correlate with vascular pathologies primarily via endothelial cell death. Though moderate HHcy is more prevalent and associated with an increased risk of cardiovascular abnormalities in later part of life, its precise role in endothelial physiology is largely unknown. In this study, we report that moderate elevation of Hcy causes endothelial dysfunction through impairment of their migration and proliferation. We established that unlike severe elevation of Hcy, moderate HHcy is not associated with suppression of endothelial VEGF/VEGFR transcripts and ROS induction. We further showed that moderate HHcy induces a sub-lethal ER stress that causes defective endothelial migration through abnormal actin cytoskeletal remodeling. We also found that sub-lethal increase in Hcy causes endothelial proliferation defect by suppressing mitochondrial respiration and concomitantly increases glycolysis to compensate the consequential ATP loss and maintain overall energy homeostasis. Finally, analyzing a previously published microarray dataset, we confirmed that these hallmarks of moderate HHcy are conserved in adult endothelial cells as well. Thus, we identified adaptive UPR and metabolic rewiring as two key mechanistic signatures in moderate HHcy-associated endothelial dysfunction. As HHcy is clinically associated with enhanced vascular inflammation and hypercoagulability, identifying these mechanistic pathways may serve as future targets to regulate endothelial function and health.
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Affiliation(s)
- Barun Chatterjee
- CSIR-Institute of Genomics & Integrative Biology, New Delhi 110025, India; (B.C.); (F.F.); (S.S.)
- Academy of Scientific & Innovative Research, Ghaziabad 201002, India
| | - Fabeha Fatima
- CSIR-Institute of Genomics & Integrative Biology, New Delhi 110025, India; (B.C.); (F.F.); (S.S.)
| | - Surabhi Seth
- CSIR-Institute of Genomics & Integrative Biology, New Delhi 110025, India; (B.C.); (F.F.); (S.S.)
- Academy of Scientific & Innovative Research, Ghaziabad 201002, India
| | - Soumya Sinha Roy
- CSIR-Institute of Genomics & Integrative Biology, New Delhi 110025, India; (B.C.); (F.F.); (S.S.)
- Academy of Scientific & Innovative Research, Ghaziabad 201002, India
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2
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Zhylkibayev A, Ung TT, Mobley J, Athar M, Gorbatyuk M. The Involvement of Unfolded Protein Response in the Mechanism of Nitrogen Mustard-Induced Ocular Toxicity. J Pharmacol Exp Ther 2024; 388:518-525. [PMID: 37914413 PMCID: PMC10801749 DOI: 10.1124/jpet.123.001814] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 09/25/2023] [Accepted: 09/26/2023] [Indexed: 11/03/2023] Open
Abstract
Nitrogen mustard (NM) is a known surrogate of sulfur mustard, a chemical-warfare agent that causes a wide range of ocular symptoms, from a permanent reduction in visual acuity to blindness upon exposure. Although it has been proposed that the two blistering agents have a similar mechanism of toxicity, the mode of NM-induced cell death in ocular tissue has not been fully explored. Therefore, we hypothesized that direct ocular exposure to NM in mice leads to retinal tissue injury through chronic activation of the unfolded protein response (UPR) PERK arm in corneal cells and VEGF secretion, eventually causing cell death. We topically applied NM directly to mice to analyze ocular and retinal tissues at 2 weeks postexposure. A dramatic decline in retinal function, measured by scotopic and photopic electroretinogram responses, was detected in the mice. This decline was associated with enhanced TUNEL staining in both corneal and retinal tissues. In addition, exposure of corneal cells to NM revealed 228 differentially and exclusively expressed proteins primarily associated with the UPR, ferroptosis, and necroptosis. Moreover, these cells exhibited activation of the UPR PERK arm and an increase in VEGF secretion. Enhancement of VEGF staining was later observed in the corneas of the exposed mice. Therefore, our data indicated that the mechanism of NM-induced ocular toxicity should be carefully examined and that future research should identify a signaling molecule transmitted via a prodeath pathway from the cornea to the retina. SIGNIFICANCE STATEMENT: This study demonstrated that NM topical exposure in mice results in dramatic decline in retinal function associated with enhanced TUNEL staining in both corneal and retinal tissues. We also found that the NM treatment of corneal cells resulted in 228 differentially and exclusively expressed proteins primarily associated with ferroptosis. Moreover, these cells manifest the UPR PERK activation and an increase in VEGF secretion. The latter was also found in the corneas of the cexposed mice.
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Affiliation(s)
- Assylbek Zhylkibayev
- School of Optometry, Department of Optometry and Vision Science (A.Z., T.T.U., M.G.), School of Medicine, Departments of Anesthesiology and Perioperative Medicine (J.M.), and Department of Dermatology (M.A.), University of Alabama at Birmingham, Birmingham, Alabama
| | - Trong Thuan Ung
- School of Optometry, Department of Optometry and Vision Science (A.Z., T.T.U., M.G.), School of Medicine, Departments of Anesthesiology and Perioperative Medicine (J.M.), and Department of Dermatology (M.A.), University of Alabama at Birmingham, Birmingham, Alabama
| | - James Mobley
- School of Optometry, Department of Optometry and Vision Science (A.Z., T.T.U., M.G.), School of Medicine, Departments of Anesthesiology and Perioperative Medicine (J.M.), and Department of Dermatology (M.A.), University of Alabama at Birmingham, Birmingham, Alabama
| | - Mohammad Athar
- School of Optometry, Department of Optometry and Vision Science (A.Z., T.T.U., M.G.), School of Medicine, Departments of Anesthesiology and Perioperative Medicine (J.M.), and Department of Dermatology (M.A.), University of Alabama at Birmingham, Birmingham, Alabama
| | - Marina Gorbatyuk
- School of Optometry, Department of Optometry and Vision Science (A.Z., T.T.U., M.G.), School of Medicine, Departments of Anesthesiology and Perioperative Medicine (J.M.), and Department of Dermatology (M.A.), University of Alabama at Birmingham, Birmingham, Alabama
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Zhang SX, Wang JJ, Starr CR, Lee EJ, Park KS, Zhylkibayev A, Medina A, Lin JH, Gorbatyuk M. The endoplasmic reticulum: Homeostasis and crosstalk in retinal health and disease. Prog Retin Eye Res 2024; 98:101231. [PMID: 38092262 PMCID: PMC11056313 DOI: 10.1016/j.preteyeres.2023.101231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 12/05/2023] [Accepted: 12/06/2023] [Indexed: 12/19/2023]
Abstract
The endoplasmic reticulum (ER) is the largest intracellular organelle carrying out a broad range of important cellular functions including protein biosynthesis, folding, and trafficking, lipid and sterol biosynthesis, carbohydrate metabolism, and calcium storage and gated release. In addition, the ER makes close contact with multiple intracellular organelles such as mitochondria and the plasma membrane to actively regulate the biogenesis, remodeling, and function of these organelles. Therefore, maintaining a homeostatic and functional ER is critical for the survival and function of cells. This vital process is implemented through well-orchestrated signaling pathways of the unfolded protein response (UPR). The UPR is activated when misfolded or unfolded proteins accumulate in the ER, a condition known as ER stress, and functions to restore ER homeostasis thus promoting cell survival. However, prolonged activation or dysregulation of the UPR can lead to cell death and other detrimental events such as inflammation and oxidative stress; these processes are implicated in the pathogenesis of many human diseases including retinal disorders. In this review manuscript, we discuss the unique features of the ER and ER stress signaling in the retina and retinal neurons and describe recent advances in the research to uncover the role of ER stress signaling in neurodegenerative retinal diseases including age-related macular degeneration, inherited retinal degeneration, achromatopsia and cone diseases, and diabetic retinopathy. In some chapters, we highlight the complex interactions between the ER and other intracellular organelles focusing on mitochondria and illustrate how ER stress signaling regulates common cellular stress pathways such as autophagy. We also touch upon the integrated stress response in retinal degeneration and diabetic retinopathy. Finally, we provide an update on the current development of pharmacological agents targeting the UPR response and discuss some unresolved questions and knowledge gaps to be addressed by future research.
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Affiliation(s)
- Sarah X Zhang
- Department of Ophthalmology and Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, United States; Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, United States.
| | - Josh J Wang
- Department of Ophthalmology and Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, United States
| | - Christopher R Starr
- Department of Optometry and Vision Science, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Eun-Jin Lee
- Department of Ophthalmology and Byers Eye Institute, Stanford University, Stanford, CA, United States; VA Palo Alto Healthcare System, Palo Alto, CA, United States; Department of Pathology, Stanford University, Stanford, CA, United States
| | - Karen Sophia Park
- Department of Ophthalmology and Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, United States
| | - Assylbek Zhylkibayev
- Department of Optometry and Vision Science, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Andy Medina
- Department of Ophthalmology and Ross Eye Institute, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, United States
| | - Jonathan H Lin
- Department of Ophthalmology and Byers Eye Institute, Stanford University, Stanford, CA, United States; VA Palo Alto Healthcare System, Palo Alto, CA, United States; Department of Pathology, Stanford University, Stanford, CA, United States
| | - Marina Gorbatyuk
- Department of Optometry and Vision Science, University of Alabama at Birmingham, Birmingham, AL, United States
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Wek RC, Anthony TG, Staschke KA. Surviving and Adapting to Stress: Translational Control and the Integrated Stress Response. Antioxid Redox Signal 2023; 39:351-373. [PMID: 36943285 PMCID: PMC10443206 DOI: 10.1089/ars.2022.0123] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 02/16/2023] [Accepted: 02/20/2023] [Indexed: 03/23/2023]
Abstract
Significance: Organisms adapt to changing environments by engaging cellular stress response pathways that serve to restore proteostasis and enhance survival. A primary adaptive mechanism is the integrated stress response (ISR), which features phosphorylation of the α subunit of eukaryotic translation initiation factor 2 (eIF2). Four eIF2α kinases respond to different stresses, enabling cells to rapidly control translation to optimize management of resources and reprogram gene expression for stress adaptation. Phosphorylation of eIF2 blocks its guanine nucleotide exchange factor, eIF2B, thus lowering the levels of eIF2 bound to GTP that is required to deliver initiator transfer RNA (tRNA) to ribosomes. While bulk messenger RNA (mRNA) translation can be sharply lowered by heightened phosphorylation of eIF2α, there are other gene transcripts whose translation is unchanged or preferentially translated. Among the preferentially translated genes is ATF4, which directs transcription of adaptive genes in the ISR. Recent Advances and Critical Issues: This review focuses on how eIF2α kinases function as first responders of stress, the mechanisms by which eIF2α phosphorylation and other stress signals regulate the exchange activity of eIF2B, and the processes by which the ISR triggers differential mRNA translation. To illustrate the synergy between stress pathways, we describe the mechanisms and functional significance of communication between the ISR and another key regulator of translation, mammalian/mechanistic target of rapamycin complex 1 (mTORC1), during acute and chronic amino acid insufficiency. Finally, we discuss the pathological conditions that stem from aberrant regulation of the ISR, as well as therapeutic strategies targeting the ISR to alleviate disease. Future Directions: Important topics for future ISR research are strategies for modulating this stress pathway in disease conditions and drug development, molecular processes for differential translation and the coordinate regulation of GCN2 and other stress pathways during physiological and pathological conditions. Antioxid. Redox Signal. 39, 351-373.
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Affiliation(s)
- Ronald C. Wek
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA
- Indiana University Melvin and Bren Simon Comprehensive Cancer Center, Indianapolis, Indiana, USA
| | - Tracy G. Anthony
- Department of Nutritional Sciences, Rutgers University, New Brunswick, New Jersey, USA
| | - Kirk A. Staschke
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA
- Indiana University Melvin and Bren Simon Comprehensive Cancer Center, Indianapolis, Indiana, USA
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Hăşmăşanu MG, Procopciuc LM, Matyas M, Zonda GI, Zaharie GC. Genetic Polymorphisms of Vascular Endothelial Growth Factor in Neonatal Pathologies: A Systematic Search and Narrative Synthesis of the Literature. CHILDREN (BASEL, SWITZERLAND) 2023; 10:children10040744. [PMID: 37189993 DOI: 10.3390/children10040744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 04/11/2023] [Accepted: 04/18/2023] [Indexed: 05/17/2023]
Abstract
(1) Background: Vascular endothelial growth factor (VEGF) is essential in vasculo- and angiogenesis due to its role in endothelial cell proliferation and migration. As a vascular proliferative factor, VEGF is one of the hallmarks of cancer and, in adult populations, the relationship between genetic polymorphism and neoplasm was widely investigated. For the neonatal population, only a few studies attempted to uncover the link between the genetic polymorphism of VEGF and neonatal pathology, especially related to late-onset complications. Our objective is to evaluate the literature surrounding VEGF genetic polymorphisms and the morbidity of the neonatal period. (2) Methods: A systematic search was initially conducted in December 2022. The PubMed platform was used to explore MEDLINE (1946 to 2022) and PubMed Central (2000 to 2022) by applying the search string ((VEGF polymorphism*) and newborn*). (3) Results: The PubMed search yielded 62 documents. A narrative synthesis of the findings was undertaken considering our predetermined subheadings (infants with low birth weight or preterm birth, heart pathologies, lung diseases, eye conditions, cerebral pathologies, and digestive pathologies). (4) Conclusion: The VEGF polymorphisms seem to be associated with neonatal pathology. The involvement of VEGF and VEGF polymorphism has been demonstrated for retinopathy of prematurity.
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Affiliation(s)
- Monica G Hăşmăşanu
- Department of Neonatology, Iuliu Haţieganu University of Medicine and Pharmacy, 400006 Cluj-Napoca, Romania
| | - Lucia M Procopciuc
- Department of Medical Biochemistry, Iuliu Haţieganu University of Medicine and Pharmacy, 400349 Cluj-Napoca, Romania
| | - Melinda Matyas
- Department of Neonatology, Iuliu Haţieganu University of Medicine and Pharmacy, 400006 Cluj-Napoca, Romania
| | - Gabriela I Zonda
- Department of Mother and Child Care, "Grigore T. Popa" University of Medicine and Pharmacy Iasi, 700115 Iași, Romania
| | - Gabriela C Zaharie
- Department of Neonatology, Iuliu Haţieganu University of Medicine and Pharmacy, 400006 Cluj-Napoca, Romania
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Askari S, Azizi F, Javadpour P, Karimi N, Ghasemi R. Endoplasmic reticulum stress as an underlying factor in leading causes of blindness and potential therapeutic effects of 4-phenylbutyric acid: from bench to bedside. EXPERT REVIEW OF OPHTHALMOLOGY 2022. [DOI: 10.1080/17469899.2022.2145945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Sahar Askari
- Neuroscience Research center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Department of Physiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Fatemeh Azizi
- Department of Neuroscience and Addiction Studies, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Pegah Javadpour
- Department of Physiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Nasser Karimi
- Eye and Skull Base Research Centers, The Five Senses Institute, Iran University of Medical Sciences, Tehran, Iran5Neurophysiology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Rasoul Ghasemi
- Department of Physiology, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Capatina N, Burton GJ, Yung HW. Elevated homocysteine activates unfolded protein responses and causes aberrant trophoblast differentiation and mouse blastocyst development. Physiol Rep 2022; 10:e15467. [PMID: 36117391 PMCID: PMC9483615 DOI: 10.14814/phy2.15467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 08/28/2022] [Accepted: 08/30/2022] [Indexed: 06/15/2023] Open
Abstract
Hyperhomocysteinemia may arise from folate/vitamin B12 deficiency, genetic polymorphisms, kidney disease, or hypothyroidism. It is associated with an increased risk of early pregnancy loss and placenta-related complications of pregnancy, including pre-eclampsia and fetal growth restriction. While the majority of studies of hyperhomocysteinemia focus on epigenetic changes secondary to metabolic disruption, the effects of homocysteine toxicity on placental development remain unexplored. Here, we investigated the influence of hyperhomocysteinemia on early blastocyst development and trophoblast differentiation. Exposure of cultured blastocysts to high homocysteine levels reduces cell number in the trophectoderm layer, most likely through increased apoptosis. Homocysteine also promotes differentiation of a trophoblast stem cell line. Both effects diminish the stem cell pool, and are mediated in an endoplasmic reticulum (ER) unfolded protein response (UPRER )-dependent manner. Targeted alleviation of UPRER may therefore provide a new therapeutic intervention to improve pregnancy outcome in women with hyperhomocysteinemia.
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Affiliation(s)
- Nadejda Capatina
- Department of Physiology, Development and Neuroscience, Centre for Trophoblast ResearchUniversity of CambridgeCambridgeUK
| | - Graham J. Burton
- Department of Physiology, Development and Neuroscience, Centre for Trophoblast ResearchUniversity of CambridgeCambridgeUK
| | - Hong Wa Yung
- Department of Physiology, Development and Neuroscience, Centre for Trophoblast ResearchUniversity of CambridgeCambridgeUK
- Department of Clinical NeuroscienceUniversity of CambridgeCambridgeUK
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Herrema H, Guan D, Choi JW, Feng X, Salazar Hernandez MA, Faruk F, Auen T, Boudett E, Tao R, Chun H, Ozcan U. FKBP11 rewires UPR signaling to promote glucose homeostasis in type 2 diabetes and obesity. Cell Metab 2022; 34:1004-1022.e8. [PMID: 35793654 DOI: 10.1016/j.cmet.2022.06.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 11/21/2021] [Accepted: 06/11/2022] [Indexed: 12/12/2022]
Abstract
Chronic endoplasmic reticulum (ER) stress and sustained activation of unfolded protein response (UPR) signaling contribute to the development of type 2 diabetes in obesity. UPR signaling is a complex signaling pathway, which is still being explored in many different cellular processes. Here, we demonstrate that FK506-binding protein 11 (FKBP11), which is transcriptionally regulated by XBP1s, is severely reduced in the livers of obese mice. Restoring hepatic FKBP11 expression in obese mice initiates an atypical UPR signaling pathway marked by rewiring of PERK signaling toward NRF2, away from the eIF2α-ATF4 axis of the UPR. This alteration in UPR signaling establishes glucose homeostasis without changing hepatic ER stress, food consumption, or body weight. We conclude that ER stress during obesity can be beneficially rewired to promote glucose homeostasis. These findings may uncover possible new avenues in the development of novel approaches to treat diseases marked by ER stress.
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Affiliation(s)
- Hilde Herrema
- Division of Endocrinology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02130, USA.
| | - Dongxian Guan
- Division of Endocrinology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02130, USA
| | - Jae Won Choi
- Division of Endocrinology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02130, USA
| | - Xudong Feng
- Division of Endocrinology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02130, USA
| | | | - Farhana Faruk
- Division of Endocrinology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02130, USA
| | - Thomas Auen
- Division of Endocrinology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02130, USA
| | - Eliza Boudett
- Division of Endocrinology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02130, USA
| | - Rongya Tao
- Division of Endocrinology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02130, USA
| | - Hyonho Chun
- Department of Mathematics and Statistics, Boston University, Boston, MA 02130, USA
| | - Umut Ozcan
- Division of Endocrinology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02130, USA.
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Homocysteine-Thiolactone Modulates Gating of Mitochondrial Voltage-Dependent Anion Channel (VDAC) and Protects It from Induced Oxidative Stress. J Membr Biol 2022; 255:79-97. [PMID: 35103807 DOI: 10.1007/s00232-022-00215-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 01/10/2022] [Indexed: 12/26/2022]
Abstract
The gating of the Voltage-Dependent Anion Channel (VDAC) is linked to oxidative stress through increased generation of mitochondrial ROS with increasing mitochondrial membrane potential (ΔΨm). It has been already reported that H2O2 increases the single-channel conductance of VDAC on a bilayer lipid membrane. On the other hand, homocysteine (Hcy) has been reported to induce mitochondria-mediated cell death. It is argued that the thiol-form of homocysteine, HTL could be the plausible molecule responsible for the alteration in the function of proteins, such as VDAC. It is hypothesized that HTL interacts with VDAC that causes functional abnormalities. An investigation was undertaken to study the interaction of HTL with VDAC under H2O2 induced oxidative stress through biophysical and electrophysiological methods. Fluorescence spectroscopic studies indicate that HTL interacts with VDAC, but under induced oxidative stress the effect is prevented partially. Similarly, bilayer electrophysiology studies suggest that HTL shows a reduction in VDAC single-channel conductance, but the effects are partially prevented under an oxidative environment. Gly172 and His181 are predicted through bioinformatics tools to be the most plausible binding residues of HTL in Rat VDAC. The binding of HTL and H2O2 with VDAC appears to be cooperative as per our analysis of experimental data in the light of the Hill-Langmuir equation. The binding energies are estimated to be - 4.7 kcal mol-1 and - 2.8 kcal mol-1, respectively. The present in vitro studies suggest that when mitochondrial VDAC is under oxidative stress, the effects of amino acid metabolites like HTL are suppressed.
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Park CY, Lee SK, Kim J, Kim D, Choe H, Jeong JH, Choi KC, Park HS, Han SN, Jang YJ. Endoplasmic reticulum stress increases LECT2 expression via ATF4. Biochem Biophys Res Commun 2021; 585:169-176. [PMID: 34808500 DOI: 10.1016/j.bbrc.2021.11.038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 11/11/2021] [Indexed: 12/23/2022]
Abstract
Non-alcoholic fatty liver disease (NAFLD) is frequently associated with obesity, insulin resistance, and endoplasmic reticulum (ER) stress. Elevated circulating levels of the hepatokine leukocyte cell-derived chemotaxin-2 (LECT2) have also been noted in NAFLD; however, the mechanism underlying this association is unclear. To investigate a possible link between ER stress/unfolded protein response (UPR) signaling and LECT2 secretion, HepG2 cells were incubated with ER stress inducers with or without an ER stress-reducing chemical chaperone. Additionally, UPR pathway genes were knocked down and overexpressed, and a ChIP assay was performed. In diet-induced obese mice, hepatic expression of LECT2 and activating transcription factor 4 (ATF4) was measured. In HepG2 cells, LECT2 expression was increased by ER stressors, an effect blocked by the chemical chaperone. Among UPR pathway proteins, only knockdown of ATF4 suppressed ER stress-induced LECT2 expression, while overexpression of ATF4 enhanced LECT2 expression. The ChIP assay revealed that ATF4 binds to three putative binding sites on the LECT2 promoter and binding is promoted by an ER stress inducer. In steatotic livers of obese mice, LECT2 and ATF4 expression was concomitantly elevated. Our data indicate that activation of ER stress/UPR signaling induces LECT2 expression in steatotic liver; specifically, ATF4 appears to mediate upregulation of LECT2 transcription.
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Affiliation(s)
- Chan Yoon Park
- Department of Physiology, University of Ulsan College of Medicine, Seoul, South Korea; Department of Food & Nutrition, College of Health Science, The University of Suwon, Hwaseong-si, Gyeonggi-do, South Korea
| | - Seul Ki Lee
- Department of Physiology, University of Ulsan College of Medicine, Seoul, South Korea
| | - Jimin Kim
- Department of Physiology, University of Ulsan College of Medicine, Seoul, South Korea
| | - Donguk Kim
- Department of Physiology, University of Ulsan College of Medicine, Seoul, South Korea
| | - Han Choe
- Department of Physiology, University of Ulsan College of Medicine, Seoul, South Korea
| | - Ji-Hoon Jeong
- Department of Biomedical Sciences, Asan Medical Center, AMIST, University of Ulsan College of Medicine, Seoul, South Korea
| | - Kyung-Chul Choi
- Department of Biomedical Sciences, Asan Medical Center, AMIST, University of Ulsan College of Medicine, Seoul, South Korea
| | - Hye Soon Park
- Department of Family Medicine, University of Ulsan College of Medicine, Seoul, South Korea
| | - Sung Nim Han
- Department of Food and Nutrition & Research Institute of Human Ecology, College of Human Ecology, Seoul National University, Seoul, South Korea
| | - Yeon Jin Jang
- Department of Physiology, University of Ulsan College of Medicine, Seoul, South Korea.
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Todorovic D, Stojanovic M, Medic A, Gopcevic K, Mutavdzin S, Stankovic S, Djuric D. Four Weeks of Aerobic Training Affects Cardiac Tissue Matrix Metalloproteinase, Lactate Dehydrogenase and Malate Dehydrogenase Enzymes Activities, and Hepatorenal Biomarkers in Experimental Hyperhomocysteinemia in Rats. Int J Mol Sci 2021; 22:ijms22136792. [PMID: 34202757 PMCID: PMC8268082 DOI: 10.3390/ijms22136792] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Revised: 06/18/2021] [Accepted: 06/22/2021] [Indexed: 12/12/2022] Open
Abstract
The aim of this study was to investigate the effect of the application of homocysteine as well as its effect under the condition of aerobic physical activity on the activities of matrix metalloproteinases (MMP), lactate dehydrogenase (LDH) and malate dehydrogenase (MDH) in cardiac tissue and on hepato-renal biochemical parameters in sera of rats. Male Wistar albino rats were divided into four groups (n = 10, per group): C: 0.9% NaCl 0.2 mL/day subcutaneous injection (s.c.); H: homocysteine 0.45 µmol/g b.w./day s.c.; CPA saline (0.9% NaCl 0.2 mL/day s.c.) and a program of physical activity on a treadmill; and HPA homocysteine (0.45 µmol/g b.w./day s.c.) and a program of physical activity on a treadmill. Subcutaneous injection of substances was applied 2 times a day at intervals of 8 h during the first two weeks of experimental protocol. Hcy level in serum was significantly higher in the HPA group compared to the CPA group (p < 0.05). Levels of glucose, proteins, albumin, and hepatorenal biomarkers were higher in active groups compared with the sedentary group. It was demonstrated that the increased activities of LDH (mainly caused by higher activity of isoform LDH2) and mMDH were found under the condition of homocysteine-treated rats plus aerobic physical activity. Independent application of homocysteine did not lead to these changes. Physical activity leads to activation of MMP-2 isoform and to increased activity of MMP-9 isoform in both homocysteine-treated and control rats.
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Affiliation(s)
- Dusan Todorovic
- Faculty of Medicine, Institute of Medical Physiology “Richard Burian”, University of Belgrade, 11000 Belgrade, Serbia; (D.T.); (M.S.); (S.M.)
| | - Marija Stojanovic
- Faculty of Medicine, Institute of Medical Physiology “Richard Burian”, University of Belgrade, 11000 Belgrade, Serbia; (D.T.); (M.S.); (S.M.)
| | - Ana Medic
- Faculty of Medicine, Institute of Chemistry in Medicine “Prof. Dr. Petar Matavulj”, University of Belgrade, 11000 Belgrade, Serbia; (A.M.); (K.G.)
| | - Kristina Gopcevic
- Faculty of Medicine, Institute of Chemistry in Medicine “Prof. Dr. Petar Matavulj”, University of Belgrade, 11000 Belgrade, Serbia; (A.M.); (K.G.)
| | - Slavica Mutavdzin
- Faculty of Medicine, Institute of Medical Physiology “Richard Burian”, University of Belgrade, 11000 Belgrade, Serbia; (D.T.); (M.S.); (S.M.)
| | - Sanja Stankovic
- Centre of Medical Biochemistry, Clinical Centre of Serbia, 11000 Belgrade, Serbia;
| | - Dragan Djuric
- Faculty of Medicine, Institute of Medical Physiology “Richard Burian”, University of Belgrade, 11000 Belgrade, Serbia; (D.T.); (M.S.); (S.M.)
- Correspondence:
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12
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GSH-Independent Induction of ER Stress during Hypoglycaemia in the Retinal Cells of Mice. J Clin Med 2021; 10:jcm10112529. [PMID: 34200353 PMCID: PMC8201117 DOI: 10.3390/jcm10112529] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 05/31/2021] [Accepted: 06/04/2021] [Indexed: 11/17/2022] Open
Abstract
Glucose is one of the most important metabolic substrates of the retina, and glycaemic imbalances can lead to serious side effects, including retinopathy. We previously showed that hypoglycaemia induces retinal cell death in mice, as well as the implication of glutathione (GSH) in this process. This study aimed to analyse the role of low glucose-induced decrease in GSH levels in endoplasmic reticulum (ER) stress. We cultured 661W photoreceptor-like cells under various glucose conditions and analysed ER stress markers at the mRNA and protein levels. We used the ERAI (“ER stress-activated indicator”) mouse model to test ER stress in both ex vivo, on retinal explants, or in vivo, in mice subjected to hypoglycaemia. Moreover, we used buthionine sulfoximine (BSO) and glutamate cysteine ligase (Gclm)-KO mice as models of low GSH to test its effects on ER stress. We show that the unfolded protein response (UPR) is triggered in 661W cells and in ERAI mice under hypoglycaemic conditions. Low GSH levels promote cell death, but have no impact on ER stress. We concluded that low glucose levels induce ER stress independently of GSH levels. Inhibition of ER stress could prevent neurodegeneration, which seems to be an early event in the pathogenesis of diabetic retinopathy.
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13
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Abdel-Ghaffar A, Elhossary GG, Mahmoud AM, Elshazly AHM, Hassanin OA, Saleh A, Mansour SM, Metwally FG, Hanafy LK, Karam SH, Darweesh N, Ata AM. Effects of 4-phenylbutyric acid on the development of diabetic retinopathy in diabetic rats: regulation of endoplasmic reticulum stress-oxidative activation. Arch Physiol Biochem 2021:1-11. [PMID: 33653182 DOI: 10.1080/13813455.2021.1888302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
There are good evidences suggesting that endoplasmic reticulum (ER) stress can be one of the contributing factors in the development of diabetic retinopathy. The present study was designed to investigate the effect of chemical chaperone 4-phenylbutyric acid (4-PBA) in alleviating the ER stress, and diabetic retinopathy in type 2 diabetic rats. Treatment of diabetic rats with 4-PBA, increased the antioxidant capacity, reduced the levels of lipid peroxidation, organised the state of apoptosis and regulated the ER stress - oxidative activation in retinal tissue. Also there was an improvement in the histological picture of retinal specimens compared to untreated diabetic rats. It was concluded that 4-PBA is a promising therapeutic agent for ER stress diseases such as diabetic retinopathy.
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Affiliation(s)
- Amany Abdel-Ghaffar
- Department of Biochemistry, Research Institute of Ophthalmology, Giza, Egypt
| | - Ghada G Elhossary
- Department of Pharmacology, Research Institute of Ophthalmology, Giza, Egypt
| | - Atef M Mahmoud
- Department of Biochemistry, Research Institute of Ophthalmology, Giza, Egypt
| | - Amany H M Elshazly
- Department of Pharmacology, Research Institute of Ophthalmology, Giza, Egypt
| | - Olfat A Hassanin
- Departments of Ophthalmology, Research Institute of Ophthalmology, Giza, Egypt
| | - Anisa Saleh
- Department of Histology, Research Institute of Ophthalmology, Giza, Egypt
| | - Sahar M Mansour
- Department of Histology, Research Institute of Ophthalmology, Giza, Egypt
| | - Fatma G Metwally
- Department of Histology, Research Institute of Ophthalmology, Giza, Egypt
| | - Laila K Hanafy
- Department of Histology, Research Institute of Ophthalmology, Giza, Egypt
| | - Sawsan H Karam
- Department of Histology, Research Institute of Ophthalmology, Giza, Egypt
| | - Neveen Darweesh
- Department of Histology, Research Institute of Ophthalmology, Giza, Egypt
| | - Ahmed Mostafa Ata
- Department of Biochemistry, Research Institute of Ophthalmology, Giza, Egypt
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14
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Alam K, Akhter Y. The Impacts of Unfolded Protein Response in the Retinal Cells During Diabetes: Possible Implications on Diabetic Retinopathy Development. Front Cell Neurosci 2021; 14:615125. [PMID: 33613197 PMCID: PMC7886690 DOI: 10.3389/fncel.2020.615125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 12/23/2020] [Indexed: 11/25/2022] Open
Abstract
Diabetic retinopathy (DR) is a vision-threatening, chronic, and challenging eye disease in the diabetic population. Despite recent advancements in the clinical management of diabetes, DR remains the major cause of blindness in working-age adults. A better understanding of the molecular and cellular basis of DR development will aid in identifying therapeutic targets. Emerging pieces of evidence from recent research in the field of ER stress have demonstrated a close association between unfolded protein response (UPR)-associated cellular activities and DR development. In this minireview article, we shall provide an emerging understating of how UPR influences DR pathogenesis at the cellular level.
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Affiliation(s)
- Kaiser Alam
- Department of Biotechnology, School of Life Sciences, Babasaheb Bhimrao Ambedkar University, Lucknow, India
| | - Yusuf Akhter
- Department of Biotechnology, School of Life Sciences, Babasaheb Bhimrao Ambedkar University, Lucknow, India
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15
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Alomar SY, M Barakat B, Eldosoky M, Atef H, Mohamed AS, Elhawary R, El-Shafey M, Youssef AM, Elkazaz AY, Gabr AM, Elaskary AA, Salih MAK, Alolayan SO, Zaitone SA. Protective effect of metformin on rat diabetic retinopathy involves suppression of toll-like receptor 4/nuclear factor-k B expression and glutamate excitotoxicity. Int Immunopharmacol 2021; 90:107193. [PMID: 33246827 DOI: 10.1016/j.intimp.2020.107193] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 10/27/2020] [Accepted: 11/08/2020] [Indexed: 01/27/2023]
Abstract
Microvascular complications of diabetes mellitus are progressively significant reasons for mortality. Metformin (MET) is considered as the first-line therapy for type 2 diabetes patients, and may be especially beneficial in cases of diabetic retinopathy although the precise mechanisms of MET action are not fully elucidated. The current study was designed to inspect the antioxidant and modulatory actions of MET on DRET in streptozotocin-induced diabetic rats. The effect of MET on the toll-like receptor 4/nuclear factor kappa B (TLR4/NFkB), inflammatory burden and glutamate excitotoxicity was assessed. Twenty-four male rats were assigned to four experimental groups: (1) Vehicle group, (2) Diabetic control: developed diabetes by injection of streptozotocin (60 mg/kg, i.p.). (3&4) Diabetic + MET group: diabetic rats were left for 9 weeks without treatment and then received oral MET 100 and 200 mg/kg for 6 weeks. Retinal samples were utilized in biochemical, histological, immunohistochemical and electron microscopic studies. MET administration significantly decreased retinal level of insulin growth factor and significantly suppressed the diabetic induced increase of malondialdehyde, glutamate, tumor necrosis factor-α and vascular endothelial growth factor (VEGF). Further, MET decreased the retinal mRNA expression of NFkB, tumor necrosis factor-α and TLR4 in diabetic rats. The current findings shed the light on MET's efficacy as an adjuvant therapy to hinder the development of diabetic retinopathy, at least partly, via inhibition of oxidative stress-induced NFkB/TLR4 pathway and suppression of glutamate excitotoxicity.
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Affiliation(s)
- Suliman Y Alomar
- Doping Research Chair, Department of Zoology, College of Science, King Saud University, Riyadh 11495, Saudi Arabia.
| | - Bassant M Barakat
- Department of Pharmacology and Toxicology, Faculty of Pharmacy (Girls), Al-Azhar University, Cairo, Egypt; Department of Clinical Pharmacy, College of Clinical Pharmacy, Al-Baha University, Al-Baha, Saudi Arabia
| | - Mohamed Eldosoky
- Department of Neuroscience Technology, College of Applied Sciences, Jubail Imam Abdulrahman bin Faisal University, Saudi Arabia
| | - Hoda Atef
- Department of Histology and Cell Biology, Faculty of Medicine, Mansoura University, Mansoura, Egypt
| | - Abdelaty Shawky Mohamed
- Pathology Department, Faculty of Medicine, Mansoura University, Mansoura, Egypt; Basic Medical Sciences Department, College of Medicine, AlMaarefa University, Riyadh, Saudi Arabia
| | - Reda Elhawary
- Department of Pathology, Faculty of Medicine, Al-Azhar University, Cairo, Egypt
| | - Mohamed El-Shafey
- Department of Anatomy and Embryology, Faculty of Medicine, Mansoura University, Mansoura, Egypt; Physiological Sciences Department, Fakeeh College for Medical Sciences, Jeddah, Saudi Arabia
| | - Amal M Youssef
- Department of Physiology, Faculty of Medicine, Suez Canal University, Ismailia, Egypt
| | - Amany Y Elkazaz
- Biochemistry and Molecular Biology Department, Faculty of Medicine, Suez Canal University, Ismailia, Egypt; Biochemistry and Molecular Biology Department, Faculty of Medicine, Portsaid University, Portsaid, Egypt
| | - Attia M Gabr
- Department of Clinical Pharmacology, Faculty of Medicine, Suez Canal University, Ismailia, Egypt; Pharmacology and Therapeutics Department, College of Medicine, Qassim University, Qassim, Saudi Arabia
| | | | - Mohamed A K Salih
- Ophthalmology Department, Al-Azher Asyut Faculty of Medicine for Men, Asyut, Egypt
| | - Sultan Othman Alolayan
- Clinical and Hospital Pharmacy Department, College of Pharmacy, Taibah University, Al-Madinah Al-Munawarah, Saudi Arabia
| | - Sawsan A Zaitone
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Suez Canal University, Ismailia 41522, Egypt; Department of Pharmacology and Toxicology, Faculty of Pharmacy, University of Tabuk, Tabuk, Saudi Arabia.
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16
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Osman A, El-Gamal H, Pasha M, Zeidan A, Korashy HM, Abdelsalam SS, Hasan M, Benameur T, Agouni A. Endoplasmic Reticulum (ER) Stress-Generated Extracellular Vesicles (Microparticles) Self-Perpetuate ER Stress and Mediate Endothelial Cell Dysfunction Independently of Cell Survival. Front Cardiovasc Med 2020; 7:584791. [PMID: 33363219 PMCID: PMC7758248 DOI: 10.3389/fcvm.2020.584791] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Accepted: 11/09/2020] [Indexed: 12/16/2022] Open
Abstract
Circulating extracellular vesicles (EVs) are recognized as biomarkers and effectors of endothelial dysfunction, the initiating step of cardiovascular abnormalities. Among these EVs, microparticles (MPs) are vesicles directly released from the cytoplasmic membrane of activated cells. MPs were shown to induce endothelial dysfunction through the activation of endoplasmic reticulum (ER) stress. However, it is not known whether ER stress can lead to MPs release from endothelial cells and what biological messages are carried by these MPs. Therefore, we aimed to assess the impact of ER stress on MPs shedding from endothelial cells, and to investigate their effects on endothelial cell function. EA.hy926 endothelial cells or human umbilical vein endothelial cells (HUVECs) were treated for 24 h with ER stress inducers, thapsigargin or dithiothreitol (DTT), in the presence or absence of 4-Phenylbutyric acid (PBA), a chemical chaperone to inhibit ER stress. Then, MPs were isolated and used to treat cells (10–20 μg/mL) for 24–48 h before assessing ER stress response, angiogenic capacity, nitric oxide (NO) release, autophagy and apoptosis. ER stress (thapsigargin or DDT)-generated MPs did not differ quantitatively from controls; however, they carried deleterious messages for endothelial function. Exposure of endothelial cells to ER stress-generated MPs increased mRNA and protein expression of key ER stress markers, indicating a vicious circle activation of ER stress. ER stress (thapsigargin)-generated MPs impaired the angiogenic capacity of HUVECs and reduced NO release, indicating an impaired endothelial function. While ER stress (thapsigargin)-generated MPs altered the release of inflammatory cytokines, they did not, however, affect autophagy or apoptosis in HUVECs. This work enhances the general understanding of the deleterious effects carried out by MPs in medical conditions where ER stress is sustainably activated such as diabetes and metabolic syndrome.
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Affiliation(s)
- Aisha Osman
- Department of Pharmaceutical Sciences, College of Pharmacy, QU Health, Qatar University, Doha, Qatar
| | - Heba El-Gamal
- Department of Pharmaceutical Sciences, College of Pharmacy, QU Health, Qatar University, Doha, Qatar
| | - Mazhar Pasha
- Department of Pharmaceutical Sciences, College of Pharmacy, QU Health, Qatar University, Doha, Qatar
| | - Asad Zeidan
- Department of Basic Sciences, College of Medicine, QU Health, Qatar University, Doha, Qatar
| | - Hesham M Korashy
- Department of Pharmaceutical Sciences, College of Pharmacy, QU Health, Qatar University, Doha, Qatar
| | - Shahenda S Abdelsalam
- Department of Pharmaceutical Sciences, College of Pharmacy, QU Health, Qatar University, Doha, Qatar
| | - Maram Hasan
- Department of Pharmaceutical Sciences, College of Pharmacy, QU Health, Qatar University, Doha, Qatar
| | - Tarek Benameur
- College of Medicine, King Faisal University, Al-Ahsa, Saudi Arabia
| | - Abdelali Agouni
- Department of Pharmaceutical Sciences, College of Pharmacy, QU Health, Qatar University, Doha, Qatar
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17
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Yadav BK, Yadav R, Kang HG, Kim KW, Lee CH, Shin BS. Association of Genetic Variation in a Wnt Signaling Pathway Gene ( β-Catenin) with Susceptibility to Leukoaraiosis. Genet Test Mol Biomarkers 2020; 24:708-716. [PMID: 33026847 DOI: 10.1089/gtmb.2020.0111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Aim: Blood-brain barrier (BBB) disruption is the primary initiating cause of cerebral small-vessel diseases including leukoaraiosis (LA). β-Catenin is a key regulator of the BBB and plays an important role in cell-cell adhesion at adherens junctions by interacting with cadherin molecules. Thus, β-Catenin may be a good candidate gene for LA. We performed a genetic analyses to investigate the association between β-catenin alleles and LA. Materials and Methods: A total of 339 LA cases and 203 controls were enrolled from individuals who underwent brain magnetic resonance imaging with obtainable vascular risk factors. Genotyping of β-catenin single nucleotide polymorphisms (SNPs), including rs1880481 C > A, rs13072632 C > T, and rs4135385 A > G, was performed by real-time polymerase chain reaction using a LightCycler 2.0. Results: Two SNPs, rs1880481 and rs4135385, showed significant differences in their allelic frequencies between the control and LA groups and the combinatorial effects of the risk alleles for these two SNPs also significantly increased the risk of LA. The G-T-A, A-T-A, and A-T-G haplotypes for the three SNPs showed significant differences in both types of LA: LA-periventricular white matter and LA-deep white matter. However, the C-T-G haplotype was only significantly different for LA-PVWM, while the A-C-A was only significantly different for LA-DWM. The combination of diabetes mellitis, hypertension, and these risk alleles increased the likelihood of both types of LA. Conclusion: This study provides evidence that β-catenin polymorphisms and their associated haplotypes are associated with susceptibility to LA.
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Affiliation(s)
- Binod Kumar Yadav
- Department of Biochemistry, Maharajgunj Medical Campus, Institute of Medicine, Tribhuvan University, Kathmandu, Nepal
| | - Renu Yadav
- Department of Dietary, Tribhuvan University Teaching Hospital, Kathmandu, Nepal
| | - Hyun Goo Kang
- Department of Neurology, Jeonbuk National University Medical School, Jeonju, Republic of Korea.,Department of Neurology, Jeonbuk National University Hospital, Jeonju, Republic of Korea
| | - Ko Woon Kim
- Department of Neurology, Jeonbuk National University Medical School, Jeonju, Republic of Korea.,Department of Neurology, Jeonbuk National University Hospital, Jeonju, Republic of Korea
| | - Chan-Hyuk Lee
- Department of Neurology, Jeonbuk National University Hospital, Jeonju, Republic of Korea
| | - Byoung-Soo Shin
- Department of Neurology, Jeonbuk National University Medical School, Jeonju, Republic of Korea.,Department of Neurology, Jeonbuk National University Hospital, Jeonju, Republic of Korea.,Research Institute of Clinical Medicine of Jeonbuk National University-Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju, Republic of Korea
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18
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Kumar A, Singh PK, Zhang K, Kumar A. Toll-like receptor 2 (TLR2) engages endoplasmic reticulum stress sensor IRE1α to regulate retinal innate responses in Staphylococcus aureus endophthalmitis. FASEB J 2020; 34:13826-13838. [PMID: 32813318 PMCID: PMC8033405 DOI: 10.1096/fj.202001393r] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 07/31/2020] [Accepted: 08/05/2020] [Indexed: 12/18/2022]
Abstract
Endoplasmic reticulum (ER) stress response has been implicated in a variety of pathophysiological conditions, including infectious and inflammatory diseases. However, its contribution in ocular bacterial infections, such as endophthalmitis, which often cause blindness is not known. Here, using a mouse model of Staphylococcus (S.) aureus endophthalmitis, our study demonstrates the induction of inositol-requiring enzyme 1α (IRE1α) and splicing of X-box binding protein-1 (Xbp1) branch of the ER-stress pathway, but not the other classical ER stress sensors. Interestingly, S aureus-induced ER stress response was found to be dependent on Toll-like receptor 2 (TLR2), as evident by reduced expression of IRE1α and Xbp1 mRNA splicing in TLR2 knockout mouse retina. Pharmacological inhibition of IRE1α using 4µ8C or experiments utilizing IRE1α-/- macrophages revealed that IRE1α positively regulates S aureus-induced inflammatory responses. Moreover, IRE1α inhibition attenuated S aureus-triggered NF-κB, p38, and ERK pathways activation and cells treated with these pathway-specific inhibitors reduced Xbp1 splicing, suggesting a positive feedback inhibition. In vivo, inhibition of IRE1α diminished the intraocular inflammation and reduced PMN infiltration in mouse eyes, but, increased the bacterial burden and caused more retinal tissue damage. These results revealed a critical role of the IRE1α/XBP1 pathway as a regulator of TLR2-mediated protective innate immune responses in S aureus-induced endophthalmitis.
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Affiliation(s)
- Ajay Kumar
- Department of Ophthalmology, Visual and Anatomical Sciences/ Kresge Eye Institute, Wayne State University School of Medicine, Detroit, MI, USA
| | - Pawan Kumar Singh
- Department of Ophthalmology, Visual and Anatomical Sciences/ Kresge Eye Institute, Wayne State University School of Medicine, Detroit, MI, USA
| | - Kezhong Zhang
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI, USA
- Department of Biochemistry, Microbiology, and Immunology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Ashok Kumar
- Department of Ophthalmology, Visual and Anatomical Sciences/ Kresge Eye Institute, Wayne State University School of Medicine, Detroit, MI, USA
- Department of Biochemistry, Microbiology, and Immunology, Wayne State University School of Medicine, Detroit, MI, USA
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19
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Ho HL, Tsai MH, Hsieh YH, Huo TI, Chang CC, Lee FY, Huang HC, Hou MC, Lee SD. Folic acid ameliorates homocysteine-induced angiogenesis and portosystemic collaterals in cirrhotic rats. Ann Hepatol 2020; 18:633-639. [PMID: 31078441 DOI: 10.1016/j.aohep.2018.12.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 12/06/2018] [Accepted: 11/23/2018] [Indexed: 02/04/2023]
Abstract
INTRODUCTION AND OBJECTIVES Liver cirrhosis is characterized by increased intrahepatic resistance, splanchnic vasodilation/angiogenesis, and formation of portosystemic collateral vessels. Collaterals can cause lethal complications such as gastroesophageal variceal hemorrhage. Homocysteine is linked to vascular dysfunction and angiogenesis and higher levels have been reported in cirrhotic patients. It is also known that folic acid supplementation reverses the effects of homocysteine. However, the treatment effect in cirrhosis has yet to be investigated. MATERIAL AND METHODS Liver cirrhosis was induced in Sprague-Dawley rats with common bile duct ligation (CBDL). The CBDL rats randomly received (1) vehicle; (2) dl-homocysteine thiolactone (1g/kg/day); (3) dl-homocysteine thiolactone plus folic acid (100mg/kg/day); or (4) folic acid. On the 29th day, hemodynamic parameters, liver and renal biochemistry, protein expressions of proangiogenic factors, mesenteric vascular density and portosystemic shunting were evaluated. RESULTS In the cirrhotic rats, homocysteine increased mesenteric vascular density and the severity of shunting. It also up-regulated the protein expressions of mesenteric vascular endothelial growth factor (VEGF) and phosphorylated-endothelial nitric oxide synthase (p-eNOS). These effects were reversed by folic acid treatment (P<0.05). CONCLUSION Folic acid ameliorated the adverse effects of homocysteine in the cirrhotic rats, which may be related to down-regulation of the VEGF-NO signaling pathway.
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Affiliation(s)
- Hsin-Ling Ho
- Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan; Institute of Pharmacology, National Yang-Ming University School of Medicine, Taipei, Taiwan; Division of Gastroenterology and Hepatology, Department of Medicine, Lo-Hsu Medical Foundation, Lotung Poh-Ai Hospital, Yilan, Taiwan
| | - Ming-Hung Tsai
- Division of Gastroenterology and Hepatology, Chang Gung Memorial Hospital, Lin-Kuo Medical Center, Chang Gung University, College of Medicine, Taoyuan, Taiwan
| | - Yu-Hsin Hsieh
- Division of Gastroenterology and Hepatology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Teh-Ia Huo
- Institute of Pharmacology, National Yang-Ming University School of Medicine, Taipei, Taiwan; Division of Gastroenterology and Hepatology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Ching-Chih Chang
- Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan; Division of General Medicine, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Fa-Yauh Lee
- Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan; Division of Gastroenterology and Hepatology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
| | - Hui-Chun Huang
- Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan; Division of Gastroenterology and Hepatology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan; Division of General Medicine, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan.
| | - Ming-Chih Hou
- Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan; Division of Gastroenterology and Hepatology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Shou-Dong Lee
- Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan; Division of Gastroenterology, Department of Medicine, Cheng Hsin General Hospital, Taipei, Taiwan
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20
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Ionizing Radiation Regulates Vascular Endothelial Growth Factor-A Transcription in Cultured Human Vascular Endothelial Cells Via the PERK/eIF2α/ATF4 Pathway. Int J Radiat Oncol Biol Phys 2020; 107:563-570. [DOI: 10.1016/j.ijrobp.2020.03.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 02/27/2020] [Accepted: 03/02/2020] [Indexed: 01/24/2023]
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21
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Shi C, Wang P, Airen S, Brown C, Liu Z, Townsend JH, Wang J, Jiang H. Nutritional and medical food therapies for diabetic retinopathy. EYE AND VISION (LONDON, ENGLAND) 2020; 7:33. [PMID: 32582807 PMCID: PMC7310218 DOI: 10.1186/s40662-020-00199-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 05/28/2020] [Indexed: 02/07/2023]
Abstract
Diabetic retinopathy (DR) is a form of microangiopathy. Reducing oxidative stress in the mitochondria and cell membranes decreases ischemic injury and end-organ damage to the retina. New approaches are needed, which reduce the risk and improve the outcomes of DR while complementing current therapeutic approaches. Homocysteine (Hcy) elevation and oxidative stress are potential therapeutic targets in DR. Common genetic polymorphisms such as those of methylenetetrahydrofolate reductase (MTHFR), increase Hcy and DR risk and severity. Patients with DR have high incidences of deficiencies of crucial vitamins, minerals, and related compounds, which also lead to elevation of Hcy and oxidative stress. Addressing the effects of the MTHFR polymorphism and addressing comorbid deficiencies and insufficiencies reduce the impact and severity of the disease. This approach provides safe and simple strategies that support conventional care and improve outcomes. Suboptimal vitamin co-factor availability also impairs the release of neurotrophic and neuroprotective growth factors. Collectively, this accounts for variability in presentation and response of DR to conventional therapy. Fortunately, there are straightforward recommendations for addressing these issues and supporting traditional treatment plans. We have reviewed the literature for nutritional interventions that support conventional therapies to reduce disease risk and severity. Optimal combinations of vitamins B1, B2, B6, L-methylfolate, methylcobalamin (B12), C, D, natural vitamin E complex, lutein, zeaxanthin, alpha-lipoic acid, and n-acetylcysteine are identified for protecting the retina and choroid. Certain medical foods have been successfully used as therapy for retinopathy. Recommendations based on this review and our clinical experience are developed for clinicians to use to support conventional therapy for DR. DR from both type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) have similar retinal findings and responses to nutritional therapies.
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Affiliation(s)
- Ce Shi
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 1638 NW 10th Avenue, McKnight Building - Room 202A, Miami, FL 33136 USA
- School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Peng Wang
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 1638 NW 10th Avenue, McKnight Building - Room 202A, Miami, FL 33136 USA
- Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Shriya Airen
- College of Arts and Sciences, University of Miami, Miami, FL USA
| | - Craig Brown
- Department of Ophthalmology, College of Medicine, the University of Arkansas for Medical Sciences, Fayetteville, AR USA
| | - Zhiping Liu
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 1638 NW 10th Avenue, McKnight Building - Room 202A, Miami, FL 33136 USA
- Ophthalmic Center, the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong China
| | - Justin H. Townsend
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 1638 NW 10th Avenue, McKnight Building - Room 202A, Miami, FL 33136 USA
| | - Jianhua Wang
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 1638 NW 10th Avenue, McKnight Building - Room 202A, Miami, FL 33136 USA
| | - Hong Jiang
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, 1638 NW 10th Avenue, McKnight Building - Room 202A, Miami, FL 33136 USA
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL USA
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A multi-omics analysis reveals the unfolded protein response regulon and stress-induced resistance to folate-based antimetabolites. Nat Commun 2020; 11:2936. [PMID: 32522993 PMCID: PMC7287054 DOI: 10.1038/s41467-020-16747-y] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 05/22/2020] [Indexed: 02/07/2023] Open
Abstract
Stress response pathways are critical for cellular homeostasis, promoting survival through adaptive changes in gene expression and metabolism. They play key roles in numerous diseases and are implicated in cancer progression and chemoresistance. However, the underlying mechanisms are only poorly understood. We have employed a multi-omics approach to monitor changes to gene expression after induction of a stress response pathway, the unfolded protein response (UPR), probing in parallel the transcriptome, the proteome, and changes to translation. Stringent filtering reveals the induction of 267 genes, many of which have not previously been implicated in stress response pathways. We experimentally demonstrate that UPR‐mediated translational control induces the expression of enzymes involved in a pathway that diverts intermediate metabolites from glycolysis to fuel mitochondrial one‐carbon metabolism. Concomitantly, the cells become resistant to the folate-based antimetabolites Methotrexate and Pemetrexed, establishing a direct link between UPR‐driven changes to gene expression and resistance to pharmacological treatment. The unfolded protein response (UPR) is a stress response pathway implicated in numerous diseases and chemotherapy resistance. Here, the authors define the UPR regulon with a multi-omics strategy, uncovering changes to mitochondrial one-carbon metabolism and concomitant resistance to folate-based therapeutics.
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Paraoan L, Sharif U, Carlsson E, Supharattanasitthi W, Mahmud NM, Kamalden TA, Hiscott P, Jackson M, Grierson I. Secretory proteostasis of the retinal pigmented epithelium: Impairment links to age-related macular degeneration. Prog Retin Eye Res 2020; 79:100859. [PMID: 32278708 DOI: 10.1016/j.preteyeres.2020.100859] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 03/24/2020] [Accepted: 03/26/2020] [Indexed: 12/19/2022]
Abstract
Secretory proteostasis integrates protein synthesis, processing, folding and trafficking pathways that are essential for efficient cellular secretion. For the retinal pigment epithelium (RPE), secretory proteostasis is of vital importance for the maintenance of the structural and functional integrity of apical (photoreceptors) and basal (Bruch's membrane/choroidal blood supply) sides of the environment it resides in. This integrity is achieved through functions governed by RPE secreted proteins, which include extracellular matrix modelling/remodelling, angiogenesis and immune response modulation. Impaired RPE secretory proteostasis affects not only the extracellular environment, but leads to intracellular protein aggregation and ER-stress with subsequent cell death. Ample recent evidence implicates dysregulated proteostasis as a key factor in the development of age-related macular degeneration (AMD), the leading cause of blindness in the developed world, and research aiming to characterise the roles of various proteins implicated in AMD-associated dysregulated proteostasis unveiled unexpected facets of the mechanisms involved in degenerative pathogenesis. This review analyses cellular processes unveiled by the study of the top 200 transcripts most abundantly expressed by the RPE/choroid in the light of the specialised secretory nature of the RPE. Functional roles of these proteins and the mechanisms of their impaired secretion, due to age and genetic-related causes, are analysed in relation to AMD development. Understanding the importance of RPE secretory proteostasis in relation to maintaining retinal health and how it becomes impaired in disease is of paramount importance for the development and assessment of future therapeutic advancements involving gene and cell therapies.
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Affiliation(s)
- Luminita Paraoan
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom.
| | - Umar Sharif
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom
| | - Emil Carlsson
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom
| | - Wasu Supharattanasitthi
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom; Department of Physiology, Faculty of Pharmacy, Mahidol University, Bangkok, Thailand
| | - Nur Musfirah Mahmud
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom
| | - Tengku Ain Kamalden
- Eye Research Centre, Department of Ophthalmology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Paul Hiscott
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom
| | - Malcolm Jackson
- Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom
| | - Ian Grierson
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom
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Wang S, Liu Y, Tan JW, Hu T, Zhang HF, Sorenson CM, Smith JA, Sheibani N. Tunicamycin-induced photoreceptor atrophy precedes degeneration of retinal capillaries with minimal effects on retinal ganglion and pigment epithelium cells. Exp Eye Res 2019; 187:107756. [PMID: 31421136 DOI: 10.1016/j.exer.2019.107756] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 08/10/2019] [Accepted: 08/13/2019] [Indexed: 12/13/2022]
Abstract
Endoplasmic reticulum (ER) stress is recognized as a contributing factor to various ocular neurovascular pathologies including retinitis pigmentosa, glaucoma, and diabetic retinopathy (DR). ER stress in particular is implicated in the development of DR, which is significantly influenced by inflammation driven retinal vascular degeneration and dysfunction. Ultimately, loss of vision occurs if left untreated. However, the identity of the target cells and their temporal involvement in diabetes-mediated dysfunction need further investigation. Early diabetes-induced stress in photoreceptor cells is proposed as the driver of inflammatory mediated neurovascular changes during diabetes. Although tunicamycin induced ER stress results in photoreceptor loss, its consequences for retinal vascular degeneration and retinal ganglion (RGC) and pigment epithelium (RPE) cell loss remains unclear. Here we show intravitreal delivery of tunicamycin primarily induced ER stress in photoreceptor cells resulting in their loss by apoptosis. This was concomitant with induced expression of the unfolded protein response marker CHOP in these cells. We also demonstrated significant degeneration of retinal capillaries following the loss of photoreceptor cells with minimal impact on loss of RGC and RPE cells. However, activation of retinal microglial and Muller cells were noticeable. Thus, our data support the notion that ER stress mediated dysfunction and/or loss of photoreceptor cells in response to inflammation and oxidative stress could precede retinal vascular and neuronal dysfunction and degeneration.
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Affiliation(s)
- Shoujian Wang
- Departments of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Yiping Liu
- Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Jin Wen Tan
- Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Tiancheng Hu
- Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Hao F Zhang
- Department of Biomedical Engineering, Northwestern University, Evanston, IL, USA
| | - Christine M Sorenson
- Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; McPherson Eye Research Institute, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA
| | - Judith A Smith
- Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
| | - Nader Sheibani
- Departments of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; McPherson Eye Research Institute, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; Biomedical Engineering, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
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25
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Wang J, Brown C, Shi C, Townsend J, Gameiro GR, Wang P, Jiang H. Improving diabetic and hypertensive retinopathy with a medical food containing L-methylfolate: a preliminary report. EYE AND VISION 2019; 6:21. [PMID: 31363484 PMCID: PMC6643316 DOI: 10.1186/s40662-019-0147-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 07/01/2019] [Indexed: 02/07/2023]
Abstract
Background Homocysteine and vitamin D may play a role in the development of diabetic and hypertensive retinopathy in patients with diabetes mellitus (DM) and hypertension. Supplementing food with L-methylfolate and vitamin D theoretically may improve diabetic and hypertensive retinopathy, however, the outcome of these nutritional approaches has not been fully examined. A retrospective case review was done of cases of retinopathy reversal in patients on Ocufolin™ and a similar nonprescription multivitamin, Eyefolate™. In this study, they were administered L-methylfolate (2.7 mg and 3.0 mg, respectively) and vitamin D3 (4500 IU each). These dosages are significantly above the RDA but well below levels associated with toxicity. Case presentation Seven patients had nonproliferative diabetic retinopathy (NPDR) and some of them had hypertension. One patient had only hypertensive retinopathy. All patients were instructed to take Ocufolin™ medical food as a food supplement. Baseline genetic testing for MTHFR polymorphisms was conducted. Fundus photography was used to document the fundus condition of the enrolled eyes in 8 NPDR patients at the initial and follow-up visits. Microaneurysms (MA) and exudates were observed to be improved in some trial patients. All subjects had one or more MTHFR polymorphisms. All had diabetic retinopathy, hypertensive retinopathy, or both. MAs were resolved, and exudates were decreased in 8/8 cases after taking the medical food. Retinal edema was found in 2/8 cases and improved or resolved in both cases after taking the medical food or the supplement. The best corrected visual activity was stable or improved in 8/8 cases. Conclusion We report a series of diabetic and hypertensive retinopathy cases with MTHFR polymorphisms and the improvement of retinal microvasculature (mainly MAs) in serial fundus photography after taking a medical food or supplement containing L-methylfolate and vitamin D. It appears that the use of nutritional supplements and medical foods containing L-methylfolate and vitamin D may be effective in facilitating the improvement of diabetic and hypertensive retinopathy.
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Affiliation(s)
- Jianhua Wang
- 1Bascom Palmer Eye Institute, University of Miami, Miller School of Medicine, 1638 NW 10th Avenue, McKnight Building - Room 202A, Miami, FL 33136 USA
| | - Craig Brown
- 2Department of Ophthalmology, College of Medicine, University of Arkansas for Medical Sciences, Fayetteville, AR USA
| | - Ce Shi
- 1Bascom Palmer Eye Institute, University of Miami, Miller School of Medicine, 1638 NW 10th Avenue, McKnight Building - Room 202A, Miami, FL 33136 USA.,3School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang China
| | - Justin Townsend
- 1Bascom Palmer Eye Institute, University of Miami, Miller School of Medicine, 1638 NW 10th Avenue, McKnight Building - Room 202A, Miami, FL 33136 USA
| | - Giovana Rosa Gameiro
- 1Bascom Palmer Eye Institute, University of Miami, Miller School of Medicine, 1638 NW 10th Avenue, McKnight Building - Room 202A, Miami, FL 33136 USA
| | - Peng Wang
- 1Bascom Palmer Eye Institute, University of Miami, Miller School of Medicine, 1638 NW 10th Avenue, McKnight Building - Room 202A, Miami, FL 33136 USA.,Department of Ophthalmology, Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Hong Jiang
- 1Bascom Palmer Eye Institute, University of Miami, Miller School of Medicine, 1638 NW 10th Avenue, McKnight Building - Room 202A, Miami, FL 33136 USA
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3'-UTR Polymorphisms in the Vascular Endothelial Growth Factor Gene (VEGF) Contribute to Susceptibility to Recurrent Pregnancy Loss (RPL). Int J Mol Sci 2019; 20:ijms20133319. [PMID: 31284523 PMCID: PMC6651559 DOI: 10.3390/ijms20133319] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 07/01/2019] [Accepted: 07/03/2019] [Indexed: 12/11/2022] Open
Abstract
Numerous studies have examined the genetic association of vascular endothelial growth factor (VEGF) single nucleotide polymorphisms (SNPs) with recurrent pregnancy loss (RPL). However, of the four known SNPs in the 3′-untranslated region (3′-UTR) of VEGF, three SNPs—namely rs3025040 (1451C>T), rs10434 (1612G>A), and rs3025053 (1725G>A)—remain poorly characterized with regard to RPL. Herein, we evaluated the association between these three SNPs in the VEGF 3′-UTR and RPL susceptibility. We analyzed VEGF 3′-UTR gene variants in with and without RPL using TaqMan allelic discrimination. There were significant differences in the genotype frequencies of 1612G>A (GA: adjusted odds ratio (AOR), 0.652; 95% confidence interval (CI), 0.447–0.951; p = 0.026) and 1725G>A (GA: AOR, 0.503; 95% CI, 0.229–0.848; p = 0.010) in RPL patients vs. controls. Our results indicate that the 1612G>A and 1725G>A polymorphisms in the 3′-UTR of VEGF are associated with RPL susceptibility in Korean women. These data suggest that VEGF 3′-UTR polymorphisms may be utilized as biomarkers for the detection of RPL risk and prevention.
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Reddy VS, Trinath J, Reddy GB. Implication of homocysteine in protein quality control processes. Biochimie 2019; 165:19-31. [PMID: 31269461 DOI: 10.1016/j.biochi.2019.06.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 06/26/2019] [Indexed: 12/22/2022]
Abstract
Homocysteine (Hcy) is a key metabolite generated during methionine metabolism. The elevated levels of Hcy in the blood are reffered to as hyperhomocystenimeia (HHcy). The HHcy is caused by impaired metabolism/deficiency of either folate or B12 or defects in Hcy metabolism. Accumulating evidence suggests that HHcy is associated with cardiovascular and brain diseases including atherosclerosis, endothelial injury, and stroke etc. Vitamin B12 (cobalamin; B12) is a water-soluble vitamin essential for two metabolic reactions. It acts as a co-factor for methionine synthase and L-methylmalonyl-CoA mutase. Besides, it is also vital for DNA synthesis and maturation of RBC. Deficiency of B12 is associated with haematological and neurological disorders. Hyperhomocysteinemia (HHcy)-induced toxicity is thought to be mediated by the accumulation of Hcy and its metabolites, homocysteinylated proteins. Cellular protein quality control (PQC) is essential for the maintenance of proteome integrity, and cell viability and its failure contributes to the development of multiple diseases. Chaperones, unfolded protein response (UPR), ubiquitin-proteasome system (UPS), and autophagy are analogous strategies of PQC that maintain cellular proteome integrity. Recently, multiple studies reported that HHcy responsible for perturbation of PQC by reducing chaperone levels, activating UPR, and impairing autophagy. Besides, HHcy also induce cytotoxicity, inflammation, protein aggregation and apoptosis. It has been shown that some of the factors including altered SIRT1-HSF1 axis and irreversible homocysteinylation of proteins are responsible for folate and/or B12 deficiency or HHcy-induced impairment of PQC. Therefore, this review highlights the current understanding of HHcy in the context of cellular PQC and their pathophysiological and clinical consequences, epigenomic changes, therapeutic implications of B12, and chemical chaperones based on cell culture and experimental animal models.
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Affiliation(s)
- V Sudhakar Reddy
- Biochemistry Division, National Institute of Nutrition, Hyderabad, India.
| | - Jamma Trinath
- Department of Biological Sciences, BITS-Pilani, 500078, Hyderabad Campus, Hyderabad, Telangana, India
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Aliyu SR, Lin L, Chen X, Abdul W, Lin Y, Otieno FJ, Shabbir A, Batool W, Zhang Y, Tang W, Wang Z, Norvienyeku J. Disruption of putative short-chain acyl-CoA dehydrogenases compromised free radical scavenging, conidiogenesis, and pathogenesis of Magnaporthe oryzae. Fungal Genet Biol 2019; 127:23-34. [PMID: 30822500 DOI: 10.1016/j.fgb.2019.02.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 02/05/2019] [Accepted: 02/25/2019] [Indexed: 12/30/2022]
Abstract
Short-chain acyl-CoA dehydrogenase (Scad) mediated β-oxidation serves as the fastest route for generating essential energies required to support the survival of organisms under stress or starvation. In this study, we identified three putative SCAD genes in the genome of the globally destructive rice blast pathogen Magnaporthe oryzae, named as MoSCAD1, MoSCAD2, and MoSCAD3. To elucidate their function, we deployed targeted gene deletion strategy to investigate individual and the combined influence of MoSCAD genes on growth, stress tolerance, conidiation and pathogenicity of the rice blast fungus. First, localization and co-localization results obtained from this study showed that MoScad1 localizes to the endoplasmic reticulum (ER), MoScad2 localizes exclusively to the mitochondria while MoScad3 partially localizes to the mitochondria and peroxisome at all developmental stages of M. oryzae. Results obtained from this investigation showed that the deletion of MoSCAD1 and MoSCAD2 caused a minimal but significant reduction in the growth of ΔMoscad1 and ΔMoscad2 strains, while, growth characteristics exhibited by the ΔMoscad3 strain was similar to the wild-type strain. Furthermore, we observed that deletion of MoSCAD2 resulted in drastic reduction in conidiation, delayed conidia germination, triggered the development of abnormal appressorium and suppressed host penetration and colonization efficiencies of the ΔMoscad1 strain. This study provides first material evidence confirming the possible existence of ER β-oxidation pathway in M. oryzae. We also infer that mitochondria β-oxidation rather than peroxisomal and ER β-oxidation play an essential role in the vegetative growth, conidiation, appressorial morphogenesis and progression of pathogenesis in M. oryzae.
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Affiliation(s)
- Sami Rukaiya Aliyu
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Lili Lin
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Xiaomin Chen
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Waheed Abdul
- Fujian University Key Laboratory for Plant-Microbe Interaction, The School of Life Sciences, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Yahong Lin
- Fujian University Key Laboratory for Plant-Microbe Interaction, The School of Life Sciences, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Frankine Jagero Otieno
- Fujian University Key Laboratory for Plant-Microbe Interaction, The School of Life Sciences, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Ammarah Shabbir
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Wajjiha Batool
- Fujian University Key Laboratory for Plant-Microbe Interaction, The School of Life Sciences, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Yiqun Zhang
- Fujian University Key Laboratory for Plant-Microbe Interaction, The School of Life Sciences, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | - Wei Tang
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Fujian University Key Laboratory for Plant-Microbe Interaction, The School of Life Sciences, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
| | - Zonghua Wang
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Fujian University Key Laboratory for Plant-Microbe Interaction, The School of Life Sciences, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Institute of Oceanography, Minjiang University, Fuzhou 350108, China.
| | - Justice Norvienyeku
- State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China; Fujian University Key Laboratory for Plant-Microbe Interaction, The School of Life Sciences, College of Plant Protection, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
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Jakubowski H. Homocysteine Modification in Protein Structure/Function and Human Disease. Physiol Rev 2019; 99:555-604. [PMID: 30427275 DOI: 10.1152/physrev.00003.2018] [Citation(s) in RCA: 135] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Epidemiological studies established that elevated homocysteine, an important intermediate in folate, vitamin B12, and one carbon metabolism, is associated with poor health, including heart and brain diseases. Earlier studies show that patients with severe hyperhomocysteinemia, first identified in the 1960s, exhibit neurological and cardiovascular abnormalities and premature death due to vascular complications. Although homocysteine is considered to be a nonprotein amino acid, studies over the past 2 decades have led to discoveries of protein-related homocysteine metabolism and mechanisms by which homocysteine can become a component of proteins. Homocysteine-containing proteins lose their biological function and acquire cytotoxic, proinflammatory, proatherothrombotic, and proneuropathic properties, which can account for the various disease phenotypes associated with hyperhomocysteinemia. This review describes mechanisms by which hyperhomocysteinemia affects cellular proteostasis, provides a comprehensive account of the biological chemistry of homocysteine-containing proteins, and discusses pathophysiological consequences and clinical implications of their formation.
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Affiliation(s)
- Hieronim Jakubowski
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers-New Jersey Medical School, International Center for Public Health , Newark, New Jersey ; and Department of Biochemistry and Biotechnology, Poznań University of Life Sciences , Poznań , Poland
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Yadav BK, Shin BS. Single-nucleotide polymorphisms of the adherent junction component cadherin gene are associated with leukoaraiosis. Gene 2018; 676:65-72. [PMID: 30017735 DOI: 10.1016/j.gene.2018.07.007] [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: 01/04/2018] [Revised: 06/26/2018] [Accepted: 07/02/2018] [Indexed: 02/07/2023]
Abstract
BACKGROUND Leukoaraiosis (LA) is one of the manifestations of cerebral small vessel disease. Blood-brain barrier (BBB) disruption plays a key role in LA. Cadherin is a component of adherent junctions (AJ), which play a crucial role in cell-cell adhesion, cell-cell recognition and homeostasis in BBB development. We hypothesized that alterations in cadherin genes might be a potential cause of BBB abnormalities that result in LA. METHODS A total of 339 LA individuals (LA-PVWM, 183; LA-DWM 156) were enrolled, who underwent brain magnetic resonance imaging with obtainable vascular risk factors. Genotyping of cadherin single-nucleotide polymorphisms (SNPs) (rs5030625, rs1801026, and rs16260) was performed by real-time polymerase chain reaction with LightSNiP reagents (coupled primer and probe) and FastStart DNAMaster HybProbe (Roche Diagnostic, GmBH, Mannheim, Germany) on a LightCycler 2.0 instrument. RESULTS Two SNPs, rs1801026 and rs16260, were significantly different between the control and LA groups. The combinatorial effects of the three SNPs were also significant. The haplotypes G-T-C and GA-T-A increased the development of LA-PVWM (OR = 1.76 and OR = 40.7, respectively). The haplotypes G-T-A and GA-T-A increased the development of LA-DWM (OR = 2.56 and OR = 10.48, respectively), but G-C-C decreased the development of LA-DWM (OR = 17.57). CONCLUSION This study provides evidence for genetic polymorphisms of the AJ component cadherin gene and the association of its haplotypes with LA.
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Affiliation(s)
- Binod Kumar Yadav
- Department of Biochemistry, Maharajgunj Medical Campus, Institute of Medicine, Tribhuvan University, Kathmandu, Nepal
| | - Byoung-Soo Shin
- Department of Neurology, Chonbuk National University Medical School, Jeonju, Chonbuk, Republic of Korea; Research Institute of Clinical Medicine of Chonbuk National University-Biomedical Research Institute of Chonbuk National University Hospital, Jeonju, Chonbuk, Republic of Korea.
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31
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Keagy CD. The potential role of folate metabolism in interstitial cystitis. Int Urogynecol J 2018; 30:363-370. [PMID: 30293165 DOI: 10.1007/s00192-018-3771-7] [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: 05/25/2018] [Accepted: 09/14/2018] [Indexed: 12/30/2022]
Abstract
The topic of interstitial cystitis (IC), also known as painful bladder syndrome (PBS), and folate/one carbon metabolism has previously been unaddressed in research. This narrative review highlights a potential connection for those with mast cell-related IC and histamine-mediated pain that is explored through four conceptual sections. The first section focuses on the nature of mast cell involvement and histamine-mediated pain in some interstitial cystitis patients. The second section reviews the literature on folate status in wider allergic conditions. The third section addresses the role of folate and methylation in general in histamine excretion. Finally, folate metabolism and vascular function are addressed because of the vascular abnormalities present in some IC bladders.
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Affiliation(s)
- Carolyn D Keagy
- Kaiser Permanente, 1795 Second Street, Berkeley, CA, 94710, USA.
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32
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Geng W, Qin F, Ren J, Xiao S, Wang A. Mini-peptide RPL41 attenuated retinal neovascularization by inducing degradation of ATF4 in oxygen-induced retinopathy mice. Exp Cell Res 2018; 369:243-250. [PMID: 29803741 DOI: 10.1016/j.yexcr.2018.05.027] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 05/22/2018] [Accepted: 05/23/2018] [Indexed: 12/14/2022]
Abstract
Endoplasmic reticulum (ER) stress signaling is activated in retinal degeneration disease. Activating transcription factor 4 (ATF4), an important mediator of the unfolded protein response (UPR), is a key element that maintains cell survival and proliferation in hypoxic conditions. Our previous studies showed that a small ribosomal protein L41 (RPL41) inhibits ATF4 by inducing its phosphorylation and degradation. In the present study, the effects of mini-peptide RPL41 on retinal neovascularization (RNV) in oxygen-induced retinopathy (OIR) mice was investigated. We induced OIR in C57BL/6 mice and obtained retinas from normoxia, OIR, OIR control (treated with PBS), and OIR treated (treated with RPL41) mice. Our results showed that ER stress signaling was activated and ATF4 was overexpressed in the retinas of OIR mice. After intravitreal injection of RPL41, the size of RNV and vaso-obliteration, and the number of preretinal neovascular cell nuclei in the retinas of OIR mice were significantly decreased. Western blot analysis and quantitative real-time polymerase chain reaction (qPCR) showed ATF4 and VEGF expression decreased after intravitreal injection of RPL41. Furthermore, the expression levels of inflammatory genes including TNF-α, IL-1β, and IL-6 were significantly decreased compared with the OIR control mice. In conclusion, RPL41 prevented pathologic neovascularization and exerted anti-inflammatory effects by degrading the important ER stress factor ATF4, thus, RPL41 could be a promising therapeutic agent for the treatment of neovascular eye diseases, especially retinopathy of prematurity (ROP).
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Affiliation(s)
- Wen Geng
- Department of Ophthalmology, Shengjing Hospital of China Medical University, Shengyang, Liaoning 110004, PR China
| | - Feng Qin
- Department of Ophthalmology, Shengjing Hospital of China Medical University, Shengyang, Liaoning 110004, PR China
| | - Jiaxu Ren
- Department of Ophthalmology, Shengjing Hospital of China Medical University, Shengyang, Liaoning 110004, PR China
| | - Sheng Xiao
- Department of Pathology, Brigham and Women's Hospital of Harvard Medical School, Boston, MA 02115, USA
| | - Aiyuan Wang
- Department of Ophthalmology, Shengjing Hospital of China Medical University, Shengyang, Liaoning 110004, PR China.
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Hu Y, Lu X, Xu Y, Lu L, Yu S, Cheng Q, Yang B, Tsui CK, Ye D, Huang J, Liang X. Salubrinal attenuated retinal neovascularization by inhibiting CHOP-HIF1α-VEGF pathways. Oncotarget 2017; 8:77219-77232. [PMID: 29100382 PMCID: PMC5652775 DOI: 10.18632/oncotarget.20431] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 06/12/2017] [Indexed: 12/30/2022] Open
Abstract
Retinal neovascularization (RNV) related disease is the leading cause of irreversible blindness in the world. The aim of this study is to identify whether salubrinal could attenuate RNV by inhibiting CCAAT/enhancer-binding protein (C/EBP) homologous protein (CHOP)- hypoxia inducible factors 1α (HIF1α) -vascular endothelial growth factor (VEGF) pathways in both mouse retinal microvascular endothelial cells (mRMECs) and oxygen-induced retinopathy (OIR) mouse model. After being treated with salubrinal (20μmol/L) or CHOP-siRNA, mRMECs were exposed to a hypoxia environment. OIR mice were intraperitoneally injected with salubrinal (0.5 mg/kg/day) from P12 to P17. With salubrinal or CHOP-siRNA treatment, the elevated CHOP protein and mRNA levels in hypoxia-induced mRMECs were significantly decreased. HIF1α-VEGF pathways were activated under hypoxia condition, then HIF1α protein was degraded and VEGF secretion was down-regulated after salubrinal or CHOP-siRNA treatment. In OIR mice, the areas of RNV were markedly decreased with salubrinal treatment. Moreover, elevated expressions of CHOP, HIF1α and VEGF in retinas of OIR mice were all reduced after salubrinal treatment. It suggested that salubrinal attenuated RNV in mRMECs and OIR mice by inhibiting CHOP-HIF1α-VEGF pathways and could be a potential therapeutic target for hypoxia-induced retinal microangiopathy.
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Affiliation(s)
- Yaguang Hu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510000, Guangdong Province, China
| | - Xi Lu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510000, Guangdong Province, China
| | - Yue Xu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510000, Guangdong Province, China
| | - Lin Lu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510000, Guangdong Province, China
| | - Shanshan Yu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510000, Guangdong Province, China
| | - Qiaochu Cheng
- Department of Ophthalmology, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710061, Shaanxi Province, China
| | - Boyu Yang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510000, Guangdong Province, China
| | - Ching-Kit Tsui
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510000, Guangdong Province, China
| | - Dan Ye
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510000, Guangdong Province, China
| | - Jingjing Huang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510000, Guangdong Province, China
| | - Xiaoling Liang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510000, Guangdong Province, China
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Singh M, Tyagi SC. Hyperhomocysteinemia and Age-related Macular Degeneration: Role of Inflammatory Mediators and Pyroptosis; A Proposal. Med Hypotheses 2017; 105:17-21. [DOI: 10.1016/j.mehy.2017.06.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 06/22/2017] [Indexed: 02/03/2023]
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Park JH, Kim M, Oh JH. Effects of bevacizumab on endoplasmic reticulum stress in hypoxic retinal pigment epithelial cells. PLoS One 2017; 12:e0179048. [PMID: 28591217 PMCID: PMC5462411 DOI: 10.1371/journal.pone.0179048] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 05/23/2017] [Indexed: 11/18/2022] Open
Abstract
Purpose To investigate the effects of bevacizumab on endoplasmic reticulum (ER) stress in human retinal pigment epithelial (RPE) cells cultured under hypoxic conditions. Methods RPE cells (ARPE–19) were cultured under hypoxic conditions (1% O2) with or without bevacizumab (0.3125 mg/mL) for 24 and 48 h. Cell viability was measured by a PrestoBlue assay. The expression of vascular endothelial growth factor (VEGF), binding protein/glucose-regulated protein 78 (BiP/GRP78), and C/EBP homologous protein-10 (CHOP) mRNA was measured by quantitative real-time polymerase chain reaction (qRT-PCR). BiP/GRP78 and CHOP protein levels in the cells were assessed by western blot. VEGF protein in the media was quantified by enzyme-linked immunosorbent assay (ELISA). Results Under hypoxic conditions, cell viability decreased and mRNA and protein levels of VEGF, BiP/GRP78, and CHOP increased compared to those under normoxic conditions. Bevacizumab improved cell viability and reduced the expression of VEGF mRNA under hypoxic conditions. Bevacizumab also reduced the expression of both mRNA and protein of two ER stress indicators, BiP/GRP78 and CHOP, under hypoxic conditions. Conclusions Bevacizumab mitigated ER stress in human RPE cells cultured under hypoxic conditions. This effect may be involved in the improved cell viability and reduction of VEGF expression after bevacizumab treatment of hypoxic RPE cells in vitro. However, the effects of bevacizumab on RPE cells under experimental conditions are unlikely to be clinically equivalent to those in the human eye.
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Affiliation(s)
- Joo-Hee Park
- Department of Ophthalmology, Dongguk University Ilsan Hospital, Goyang, South Korea
| | - Moosang Kim
- Department of Ophthalmology, School of Medicine, Kangwon National University, Chuncheon, South Korea
| | - Jong-Hyun Oh
- Department of Ophthalmology, Dongguk University Ilsan Hospital, Goyang, South Korea
- * E-mail:
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Wang Y, Gao S, Zhu Y, Shen X. Elevated Activating Transcription Factor 4 and Glucose-Regulated 78 Kda Protein Levels Correlate with Inflammatory Cytokines in the Aqueous Humor and Vitreous of Proliferative Diabetic Retinopathy. Curr Eye Res 2017; 42:1202-1208. [PMID: 28497987 DOI: 10.1080/02713683.2017.1297998] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE To determine concentrations of endoplasmic reticulum (ER) stress-related factors activating transcription factor 4 (ATF4) and glucose-regulated 78 kDa protein (GRP78) in vitreous and aqueous humor (AqH) of patients with proliferative diabetic retinopathy (PDR) and the correlation of ATF4, GRP78 and inflammatory cytokines interleukin-6(IL-6) and monocyte chemoattractant protein-1 (MCP-1). MATERIALS AND METHODS AqH and vitreous samples were collected from eyes of patients with PDR and idiopathic macular hole (IMH) which needed vitrectomy. Protein Levels of ATF4, GRP78, and IL-6, MCP-1 in samples were evaluated using enzyme-linked immunosorbent assay (ELISA). RESULTS ELISA analysis revealed significantly increased levels in both AqH and vitreous of ATF4 and GRP78 in eyes affected with PDR compared to the controls (all p < 0.001). The mean concentrations of IL-6, MCP-1 were also higher in both AqH and vitreous samples from patients with PDR compared to those of IMH (all p < 0.001). (Independent Student t-test, normality test followed with Skewness-Kurtosis Test). In addition, correlations of ATF4 and GRP78 with inflammatory factors IL-6 and MCP-1 in subjects of patients were analyzed. No significant correlation between the AqH concentrations of ATF4/IL-6 and ATF4/MCP-1 was detected in eyes of PDR patients (r = 0.346, p = 0.072 and r = 0.275, p = 0.157). Significant correlations were observed between AqH concentrations of GRP78/IL-6 (r = 0.724, p < 0.001), GRP78/MCP-1 (r = 0.654, p < 0.001) in PDR patients. Significant correlations were observed between vitreous concentrations of ATF4/IL-6 (r = 0.918, p < 0.001), ATF4/MCP-1 (r = 0.921, p < 0.001), GRP78/IL-6 (r = 0.978, p < 0.001), GRP78/MCP-1 (r = 0.979, p < 0.001) in PDR patients. No significant correlations was observed between AqH concentrations of ATF4/IL-6 (r = 0.187, p = 474), ATF4/MCP-1 (r = 0.240, p = 0.353), GRP78/IL-6 (r = 0.321, p = 0.209) and GRP78/MCP-1 (r = 0.169, p = 0.516) in eyes of IMH patients. And also no significant correlation was observed between vitreous concentrations of ATF4/IL-6 (r = 0.130, p = 0.563), ATF4/MCP-1(r = 0.029, p = 0.897), GRP78/IL-6 (r = 0.078, p = 0.717), GRP78/MCP-1 (r = 0.005, p = 0.982) in IMH patients. (Pearson correlation coefficient (two-tailed)). CONCLUSIONS Our results demonstrated that ATF4 and GRP78 may play an important role in the pathogenesis of PDR and work in concert with inflammatory cytokines IL-6 and MCP-1 in pathological process. ATF4 and GRP78 may be good diagnostic biomarkers and new therapeutic targets for PDR. ABBREVIATIONS ER stress, endoplasmic reticulum stress; ATF4, activating transcription factor 4; GRP78, glucose-regulated 78 kDa protein; AqH, aqueous humor; PDR, proliferative diabetic retinopathy; IL-6, interleukin-6; MCP-1, monocyte chemoattractant protein-1; IMH, idiopathic macular hole.
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Affiliation(s)
- Yanuo Wang
- a Department of Ophthalmology , Ruijin Hospital, Shanghai Jiao Tong University, School of Medicine , Shanghai , China
| | - Sha Gao
- a Department of Ophthalmology , Ruijin Hospital, Shanghai Jiao Tong University, School of Medicine , Shanghai , China
| | - Yanji Zhu
- a Department of Ophthalmology , Ruijin Hospital, Shanghai Jiao Tong University, School of Medicine , Shanghai , China
| | - Xi Shen
- a Department of Ophthalmology , Ruijin Hospital, Shanghai Jiao Tong University, School of Medicine , Shanghai , China
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Doultsinos D, Avril T, Lhomond S, Dejeans N, Guédat P, Chevet E. Control of the Unfolded Protein Response in Health and Disease. SLAS DISCOVERY 2017; 22:787-800. [PMID: 28453376 DOI: 10.1177/2472555217701685] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The unfolded protein response (UPR) is an integrated, adaptive biochemical process that is inextricably linked with cell homeostasis and paramount to maintenance of normal physiological function. Prolonged accumulation of improperly folded proteins in the endoplasmic reticulum (ER) leads to stress. This is the driving stimulus behind the UPR. As such, prolonged ER stress can push the UPR past beneficial functions such as reduced protein production and increased folding and clearance to apoptotic signaling. The UPR is thus contributory to the commencement, maintenance, and exacerbation of a multitude of disease states, making it an attractive global target to tackle conditions sorely in need of novel therapeutic intervention. The accumulation of information of screening tools, readily available therapies, and potential pathways to drug development is the cornerstone of informed clinical research and clinical trial design. Here, we review the UPR's involvement in health and disease and, beyond providing an in-depth description of the molecules found to target the three UPR arms, we compile all the tools available to screen for and develop novel therapeutic agents that modulate the UPR with the scope of future disease intervention.
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Affiliation(s)
- Dimitrios Doultsinos
- 1 Inserm U1242, Chemistry, Oncogenesis, Stress & Signaling, University of Rennes 1, Rennes, France.,2 Centre de Lutte contre le Cancer Eugène Marquis, Rennes, France
| | - Tony Avril
- 1 Inserm U1242, Chemistry, Oncogenesis, Stress & Signaling, University of Rennes 1, Rennes, France.,2 Centre de Lutte contre le Cancer Eugène Marquis, Rennes, France
| | | | | | | | - Eric Chevet
- 1 Inserm U1242, Chemistry, Oncogenesis, Stress & Signaling, University of Rennes 1, Rennes, France.,2 Centre de Lutte contre le Cancer Eugène Marquis, Rennes, France.,3 BMYscreen, Bergonié Cancer Institute, Bordeaux, France
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Single-nucleotide Polymorphisms in Vascular Endothelial Growth Factor Gene Associated with Stroke Subtype in LAA and SVO. INT J GERONTOL 2017. [DOI: 10.1016/j.ijge.2016.09.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Tung HC, Hsu SJ, Tsai MH, Lin TY, Hsin IF, Huo TI, Lee FY, Huang HC, Ho HL, Lin HC, Lee SD. Homocysteine deteriorates intrahepatic derangement and portal-systemic collaterals in cirrhotic rats. Clin Sci (Lond) 2017; 131:69-86. [DOI: 10.1042/cs20160470] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
Abstract
In liver cirrhosis, the altered levels of vasoactive substances, especially endothelin-1 (ET-1) and nitric oxide (NO) lead to elevated intrahepatic resistance, increased portal-systemic collaterals and abnormal intra- and extra-hepatic vascular responsiveness. These derangements aggravate portal hypertension-related complications such as gastro-oesophageal variceal bleeding. Homocysteine, a substance implicated in cardiovascular diseases, has been found with influences on vasoresponsiveness and angiogenesis. However, their relevant effects in liver cirrhosis have not been investigated. In the present study, liver cirrhosis was induced by common bile duct ligation (BDL) in Sprague–Dawley rats. In acute study, the results showed that homocysteine enhanced hepatic vasoconstriction to ET-1 but decreased portal-systemic collateral vasocontractility to arginine vasopressin (AVP). Homocysteine down-regulated hepatic phosphorylated endothelial NO synthase (p-eNOS) and p-Akt protein expressions. Inducible NOS (iNOS) and cyclooxygenase (COX)-2 expressions were up-regulated by homocysteine in splenorenal shunt (SRS), the most prominent intra-abdominal collateral vessel. In chronic study, BDL or thioacetamide (TAA) rats received homocysteine or vehicle for 14 days. The results revealed that homocysteine increased hepatic collagen fibre deposition and fibrotic factors expressions in both BDL- and TAA-induced liver fibrotic rats. Portal-systemic shunting and expressions of mesenteric angiogenetic factors [vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), PDGF receptor β (PDGFRβ) and p-eNOS] were also increased in BDL rats. In conclusion, homocysteine is harmful to vascular derangements and liver fibrosis in cirrhosis.
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Affiliation(s)
- Hung-Chun Tung
- Institute of Pharmacology, National Yang-Ming University School of Medicine, Taipei, Taiwan
| | - Shao-Jung Hsu
- Institute of Pharmacology, National Yang-Ming University School of Medicine, Taipei, Taiwan
- Division of Gastroenterology and Hepatology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan
| | - Ming-Hung Tsai
- Chang Gung University College of Medicine and Division of Gastroenterology and Hepatology, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Te-Yueh Lin
- Division of Gastroenterology and Hepatology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
| | - I-Fang Hsin
- Institute of Pharmacology, National Yang-Ming University School of Medicine, Taipei, Taiwan
- Division of Endoscopy Center for Diagnosis and Treatment, Taipei Veterans General Hospital, Taipei, Taiwan
- Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan
| | - Te-Ia Huo
- Institute of Pharmacology, National Yang-Ming University School of Medicine, Taipei, Taiwan
- Division of Gastroenterology and Hepatology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Fa-Yauh Lee
- Division of Gastroenterology and Hepatology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan
| | - Hui-Chun Huang
- Division of Gastroenterology and Hepatology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan
- Division of General Medicine, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Hsin-Ling Ho
- Institute of Pharmacology, National Yang-Ming University School of Medicine, Taipei, Taiwan
- Division of Gastroenterology and Hepatology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Han-Chieh Lin
- Division of Gastroenterology and Hepatology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan
| | - Shou-Dong Lee
- Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan
- Division of Gastroenterology, Department of Medicine, Cheng Hsin General Hospital, Taipei, Taiwan
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Steger CM, Mayr T, Bonaros N, Bonatti J, Schachner T. Vein graft disease in a knockout mouse model of hyperhomocysteinaemia. Int J Exp Pathol 2016; 97:447-456. [PMID: 28004436 DOI: 10.1111/iep.12215] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Accepted: 11/15/2016] [Indexed: 12/28/2022] Open
Abstract
A major reason for vein graft failure after coronary artery bypass grafting is neointimal hyperplasia and thrombosis. Elevated serum levels of homocysteine (Hcy) are associated with higher incidence of cardiovascular disease, but homocysteine levels also tend to increase during the first weeks or months after cardiac surgery. To investigate this further, C57BL/6J mice (WT) and cystathionine-beta-synthase heterozygous knockout mice (CBS+/-), a mouse model for hyperhomocysteinaemia, underwent interposition of the vena cava of donor mice into the carotid artery of recipient mice. Two experimental groups were examined: 20 mice of each group underwent bypass surgery (group 1: WT donor and WT recipient; group 2: CBS+/- donor and CBS+/- recipient). After 4 weeks, the veins were harvested, dehydrated, paraffin-embedded, stained and analysed by histomorphology and immunohistochemistry. Additionally, serum Hcy levels in CBS knockout animals and in WT animals before and after bypass surgery were measured. At 4 weeks postoperatively, group 2 mice showed a higher percentage of thrombosis compared to controls, a threefold increase in neointima formation, higher general vascularization, a lower percentage of elastic fibres with shortage and fragmentation in the neointima, a lower percentage of acid mucopolysaccharides in the neointima and a more intense fibrosis in the neointima and media. In conclusion, hyperhomocysteinaemic cystathionine-beta-synthase knockout mice can play an important role in the study of mechanisms of vein graft failure. But further in vitro and in vivo studies are necessary to answer the question whether or not homocysteine itself or a related metabolic factor is the key aetiologic agent for accelerated vein graft disease.
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Affiliation(s)
- Christina Maria Steger
- Department of Pathology, Academic Teaching Hospital Feldkirch (Affiliation of the Innsbruck Medical University), Feldkirch, Austria
| | - Tobias Mayr
- Department of Surgery, State Hospital Kufstein, Kufstein, Austria
| | - Nikolaos Bonaros
- Department of Cardiac Surgery, Innsbruck Medical University, Innsbruck, Austria
| | - Johannes Bonatti
- Heart and Vascular Institute, Cleveland Clinic Abu Dhabi, Abu Dhabi, UAE
| | - Thomas Schachner
- Department of Cardiac Surgery, Innsbruck Medical University, Innsbruck, Austria
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Stokes MB, Zviti R, Lin F, D'Agati VD. An unusual cause of hypertension with hematuria and proteinuria: Answers. Pediatr Nephrol 2016; 31:2265-2270. [PMID: 26980089 DOI: 10.1007/s00467-016-3348-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 02/05/2016] [Indexed: 01/27/2023]
Affiliation(s)
- Michael B Stokes
- Columbia University Medical Center, New York, NY, 10032, USA. .,Department of Pathology, Renal Pathology Laboratory, Columbia University College of Physicians and Surgeons, VC14-224, New York, NY, 10032, USA.
| | - Ronald Zviti
- Columbia University Medical Center, New York, NY, 10032, USA.,Department of Pediatrics, Columbia University College of Physicians and Surgeons, New York, NY, USA
| | - Fangming Lin
- Columbia University Medical Center, New York, NY, 10032, USA.,Department of Pathology, Renal Pathology Laboratory, Columbia University College of Physicians and Surgeons, VC14-224, New York, NY, 10032, USA.,Department of Pediatrics, Columbia University College of Physicians and Surgeons, New York, NY, USA
| | - Vivette D D'Agati
- Columbia University Medical Center, New York, NY, 10032, USA.,Department of Pathology, Renal Pathology Laboratory, Columbia University College of Physicians and Surgeons, VC14-224, New York, NY, 10032, USA
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Ahluwalia TS, Troelsen JT, Balslev-Harder M, Bork-Jensen J, Thuesen BH, Cerqueira C, Linneberg A, Grarup N, Pedersen O, Hansen T, Dalgaard LT. Carriers of a VEGFA enhancer polymorphism selectively binding CHOP/DDIT3 are predisposed to increased circulating levels of thyroid-stimulating hormone. J Med Genet 2016; 54:166-175. [PMID: 27627987 DOI: 10.1136/jmedgenet-2016-104084] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 08/08/2016] [Accepted: 08/22/2016] [Indexed: 01/15/2023]
Abstract
BACKGROUND Levels of serum thyroid-stimulating hormone (TSH) indicate thyroid function, because thyroid hormone negatively controls TSH release. Genetic variants in the vascular endothelial growth factor A (VEGFA) gene are associated with TSH levels. The aim of this study was to characterise the association of VEGFA variants with TSH in a Danish cohort and to identify and characterise functional variants. METHODS We performed an association study of the VEGFA locus for circulating TSH levels in 8445 Danish individuals. Lead variants were tested for allele-specific effects in vitro using luciferase reporter and gel-shift assays. RESULTS Four SNPs in VEGFA were associated with circulating TSH (rs9472138, rs881858, rs943080 and rs4711751). For rs881858, the presence of each G-allele was associated with a corresponding decrease in TSH levels of 2.3% (p=8.4×10-9) and an increase in circulating free T4 levels (p=0.0014). The SNP rs881858 is located in a binding site for CHOP (C/EBP homology protein) and c/EBPβ (ccaat enhancer binding protein β). Reporter-gene analysis showed increased basal enhancer activity of the rs881858 A-allele versus the G-allele (34.5±9.9% (average±SEM), p=0.0012), while co-expression of CHOP effectively suppressed the rs881858 A-allele activity. The A-allele showed stronger binding to CHOP in gel-shift assays. CONCLUSIONS VEGF is an important angiogenic signal required for tissue expansion. We show that VEGFA variation giving allele-specific response to transcription factors with overlapping binding sites associate closely with circulating TSH levels. Because CHOP is induced by several types of intracellular stress, this indicates that cellular stress could be involved in the normal or pathophysiological response of the thyroid to TSH. TRIAL REGISTRATION NUMBER NCT00289237, NCT00316667; Results.
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Affiliation(s)
- Tarunveer Singh Ahluwalia
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Section of Metabolic Genetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Steno Diabetes Center, Gentofte, Denmark
| | | | - Marie Balslev-Harder
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Section of Metabolic Genetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jette Bork-Jensen
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Section of Metabolic Genetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Charlotte Cerqueira
- Research Centre for Prevention and Health, The Capital Region, Glostrup, Denmark
| | - Allan Linneberg
- Research Centre for Prevention and Health, The Capital Region, Glostrup, Denmark.,Department of Clinical Experimental Research, Rigshospitalet, Copenhagen, Denmark.,Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Niels Grarup
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Section of Metabolic Genetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Oluf Pedersen
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Section of Metabolic Genetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Torben Hansen
- The Novo Nordisk Foundation Center for Basic Metabolic Research, Section of Metabolic Genetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark
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EFFECT OF PEGAPTANIB AND RANIBIZUMAB ON PLASMA AND VITREOUS HOMOCYSTEINE IN PATIENTS WITH EXUDATIVE AGE-RELATED MACULAR DEGENERATION. Retina 2016; 35:1765-71. [PMID: 25923955 DOI: 10.1097/iae.0000000000000552] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To investigate homocysteine (Hcy) concentration in the blood plasma and the vitreous in patients with exudative age-related macular degeneration receiving intravitreal anti-vascular endothelial growth factor therapy. METHODS Plasma Hcy and vitreous Hcy levels were analyzed in 73 exudative age-related macular degeneration patients (50.7% received pegaptanib 0.3 mg and 50.3% received ranibizumab 0.5 mg) and compared with 80 controls and 40 patients with idiopathic epiretinal membranes, respectively. Homocysteine concentration was measured by immunonephelometric particle test, and it was determined before and after antiangiogenic therapy. RESULTS The mean Hcy concentrations (± SD) of blood plasma and vitreous were 13.0 ± 4.2 μmol/L and 1.00 ± 0.3 μmol/L in patients treated with pegaptanib; in ranibizumab group, they were 12.8 ± 2.5 μmol/L and 1.4 ± 0.6 μmol/L, respectively. The results of plasma and vitreous Hcy indicated statistically significant differences between exudative age-related macular degeneration patients and control groups (P = 0.03 and P = 0.02). After 6 months with both intravitreal therapies, the plasma and vitreous Hcy concentrations did not change significantly (P = 0.1). CONCLUSION Pegaptanib and ranibizumab did not increase the plasma or vitreous Hcy concentrations.
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Martins AS, Alves I, Helguero L, Domingues MR, Neves BM. The Unfolded Protein Response in Homeostasis and Modulation of Mammalian Immune Cells. Int Rev Immunol 2016; 35:457-476. [PMID: 27119724 DOI: 10.3109/08830185.2015.1110151] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The endoplasmic reticulum (ER) plays important roles in eukaryotic protein folding and lipid biosynthesis. Several exogenous and endogenous cellular sources of stress can perturb ER homeostasis leading to the accumulation of unfolded proteins in the lumen. Unfolded protein accumulation triggers a signal-transduction cascade known as the unfolded protein response (UPR), an adaptive mechanism which aims to protect cells from protein aggregates and to restore ER functions. Further to this protective mechanism, in immune cells, UPR molecular effectors have been shown to participate in a wide range of biological processes such as cell differentiation, survival and immunoglobulin and cytokine production. Recent findings also highlight the involvement of the UPR machinery in the maturational program and antigen presentation capacities of dendritic cells. UPR is therefore a key element in immune system homeostasis with direct implications on both adaptive and innate immune responses. The present review summarizes the knowledge on the emerging roles of UPR signaling cascades in mammalian immune cells as well as the consequences of their dysregulation in relation to the pathogenesis of several diseases.
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Affiliation(s)
- Ana Sofia Martins
- a Mass Spectrometry Centre, Department of Chemistry and QOPNA , University of Aveiro, Campus Universitário de Santiago , Aveiro , Portugal
| | - Inês Alves
- a Mass Spectrometry Centre, Department of Chemistry and QOPNA , University of Aveiro, Campus Universitário de Santiago , Aveiro , Portugal
| | - Luisa Helguero
- a Mass Spectrometry Centre, Department of Chemistry and QOPNA , University of Aveiro, Campus Universitário de Santiago , Aveiro , Portugal.,b Institute for Research in Biomedicine - iBiMED, Health Sciences Program, Universidade de Aveiro , Portugal
| | - Maria Rosário Domingues
- a Mass Spectrometry Centre, Department of Chemistry and QOPNA , University of Aveiro, Campus Universitário de Santiago , Aveiro , Portugal
| | - Bruno Miguel Neves
- a Mass Spectrometry Centre, Department of Chemistry and QOPNA , University of Aveiro, Campus Universitário de Santiago , Aveiro , Portugal.,c Faculty of Pharmacy and Centre for Neuroscience and Cell Biology, University of Coimbra , Coimbra , Portugal
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Jain K, Suryakumar G, Ganju L, Singh SB. Amelioration of ER stress by 4-phenylbutyric acid reduces chronic hypoxia induced cardiac damage and improves hypoxic tolerance through upregulation of HIF-1α. Vascul Pharmacol 2016; 83:36-46. [PMID: 27058435 DOI: 10.1016/j.vph.2016.03.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 02/27/2016] [Accepted: 03/12/2016] [Indexed: 12/14/2022]
Abstract
While endoplasmic reticulum (ER) stress has been observed in several human diseases, few studies have reported the involvement of ER stress in chronic hypoxia (CH) induced cardiac damage. Hypoxia, such as that prevalent at high altitude (HA), forms the underlying cause of several maladies including cardiovascular diseases. While the role of hypoxia inducible factor-1 (HIF-1α) in the adaptive responses to hypoxia is known, the role of the unfolded protein response (UPR) is only recently being explored in the HA pathophysiologies. The present study investigates the effect of ER stress modulation on CH mediated injury and the cardioprotective action of 4-phenylbutyric acid (PBA) in enhancing survival response under hypoxia. Here, we observed that exposure of rats, for 1, 7 and 14days CH to a simulated altitude of 7620m, led to cardiac hypertrophy and significant protein oxidation. This induced the activation of UPR signaling mechanisms, mediated by PERK, IRE1α and ATF6. By 14days, there was a marked upregulation of apoptosis, evident in increased CHOP and caspase-3/9 activity. PBA reduced CH induced right ventricular enlargement and apoptosis. Further, in contrast to tunicamycin, PBA considerably enhanced hypoxic tolerance. An elevation in the level of antioxidant enzymes, HIF-1α and its regulated proteins (HO-1, GLUT-1) was observed in the PBA administered animals, along with a concomitant suppression of UPR markers. Our study thus emphasizes upon the attenuation of ER stress by PBA as a mechanism to diminish CH induced cardiac injury and boost hypoxic survival, providing an insight into the novel relationship between the HIF-1α and UPR under hypoxia.
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Affiliation(s)
- Kanika Jain
- Cellular Biochemistry Division, Defence Institute of Physiology and Allied Sciences, Lucknow Road, Timarpur, Delhi 110 054, India
| | - Geetha Suryakumar
- Cellular Biochemistry Division, Defence Institute of Physiology and Allied Sciences, Lucknow Road, Timarpur, Delhi 110 054, India.
| | - Lilly Ganju
- Cellular Biochemistry Division, Defence Institute of Physiology and Allied Sciences, Lucknow Road, Timarpur, Delhi 110 054, India
| | - Shashi Bala Singh
- Cellular Biochemistry Division, Defence Institute of Physiology and Allied Sciences, Lucknow Road, Timarpur, Delhi 110 054, India
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46
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Saha S, Chakraborty PK, Xiong X, Dwivedi SKD, Mustafi SB, Leigh NR, Ramchandran R, Mukherjee P, Bhattacharya R. Cystathionine β-synthase regulates endothelial function via protein S-sulfhydration. FASEB J 2016; 30:441-56. [PMID: 26405298 PMCID: PMC4684530 DOI: 10.1096/fj.15-278648] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Accepted: 09/14/2015] [Indexed: 12/31/2022]
Abstract
Deficiencies of the human cystathionine β-synthase (CBS) enzyme are characterized by a plethora of vascular disorders and hyperhomocysteinemia. However, several clinical trials demonstrated that despite reduction in homocysteine levels, disease outcome remained unaffected, thus the mechanism of endothelial dysfunction is poorly defined. Here, we show that the loss of CBS function in endothelial cells (ECs) leads to a significant down-regulation of cellular hydrogen sulfide (H2S) by 50% and of glutathione (GSH) by 40%. Silencing CBS in ECs compromised phenotypic and signaling responses to the VEGF that were potentiated by decreased transcription of VEGF receptor (VEGFR)-2 and neuropilin (NRP)-1, the primary receptors regulating endothelial function. Transcriptional down-regulation of VEGFR-2 and NRP-1 was mediated by a lack in stability of the transcription factor specificity protein 1 (Sp1), which is a sulfhydration target of H2S at residues Cys68 and Cys755. Reinstating H2S but not GSH in CBS-silenced ECs restored Sp1 levels and its binding to the VEGFR-2 promoter and VEGFR-2, NRP-1 expression, VEGF-dependent proliferation, and migration phenotypes. Thus, our study emphasizes the importance of CBS-mediated protein S-sulfhydration in maintaining vascular health and function.-Saha, S., Chakraborty, P. K., Xiong, X., Dwivedi, S. K. D., Mustafi, S. B., Leigh, N. R., Ramchandran, R., Mukherjee, P., Bhattacharya, R. Cystathionine β-synthase regulates endothelial function via protein S-sulfhydration.
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Affiliation(s)
- Sounik Saha
- *Peggy and Charles Stephenson Cancer Center, Department of Obstetrics and Gynecology, Department of Pathology, and Department of Cell Biology, University of Oklahoma Health Science Center, Oklahoma City, Oklahoma, USA; and Developmental Vascular Biology Program and Zebrafish Drug Screening Core, Department of Obstetrics and Gynecology, The Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Prabir K Chakraborty
- *Peggy and Charles Stephenson Cancer Center, Department of Obstetrics and Gynecology, Department of Pathology, and Department of Cell Biology, University of Oklahoma Health Science Center, Oklahoma City, Oklahoma, USA; and Developmental Vascular Biology Program and Zebrafish Drug Screening Core, Department of Obstetrics and Gynecology, The Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Xunhao Xiong
- *Peggy and Charles Stephenson Cancer Center, Department of Obstetrics and Gynecology, Department of Pathology, and Department of Cell Biology, University of Oklahoma Health Science Center, Oklahoma City, Oklahoma, USA; and Developmental Vascular Biology Program and Zebrafish Drug Screening Core, Department of Obstetrics and Gynecology, The Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Shailendra Kumar Dhar Dwivedi
- *Peggy and Charles Stephenson Cancer Center, Department of Obstetrics and Gynecology, Department of Pathology, and Department of Cell Biology, University of Oklahoma Health Science Center, Oklahoma City, Oklahoma, USA; and Developmental Vascular Biology Program and Zebrafish Drug Screening Core, Department of Obstetrics and Gynecology, The Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Soumyajit Banerjee Mustafi
- *Peggy and Charles Stephenson Cancer Center, Department of Obstetrics and Gynecology, Department of Pathology, and Department of Cell Biology, University of Oklahoma Health Science Center, Oklahoma City, Oklahoma, USA; and Developmental Vascular Biology Program and Zebrafish Drug Screening Core, Department of Obstetrics and Gynecology, The Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Noah R Leigh
- *Peggy and Charles Stephenson Cancer Center, Department of Obstetrics and Gynecology, Department of Pathology, and Department of Cell Biology, University of Oklahoma Health Science Center, Oklahoma City, Oklahoma, USA; and Developmental Vascular Biology Program and Zebrafish Drug Screening Core, Department of Obstetrics and Gynecology, The Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Ramani Ramchandran
- *Peggy and Charles Stephenson Cancer Center, Department of Obstetrics and Gynecology, Department of Pathology, and Department of Cell Biology, University of Oklahoma Health Science Center, Oklahoma City, Oklahoma, USA; and Developmental Vascular Biology Program and Zebrafish Drug Screening Core, Department of Obstetrics and Gynecology, The Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Priyabrata Mukherjee
- *Peggy and Charles Stephenson Cancer Center, Department of Obstetrics and Gynecology, Department of Pathology, and Department of Cell Biology, University of Oklahoma Health Science Center, Oklahoma City, Oklahoma, USA; and Developmental Vascular Biology Program and Zebrafish Drug Screening Core, Department of Obstetrics and Gynecology, The Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Resham Bhattacharya
- *Peggy and Charles Stephenson Cancer Center, Department of Obstetrics and Gynecology, Department of Pathology, and Department of Cell Biology, University of Oklahoma Health Science Center, Oklahoma City, Oklahoma, USA; and Developmental Vascular Biology Program and Zebrafish Drug Screening Core, Department of Obstetrics and Gynecology, The Medical College of Wisconsin, Milwaukee, Wisconsin, USA
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Matsui A, Kaneko H, Kachi S, Ye F, Hwang SJ, Takayama K, Nagasaka Y, Sugita T, Terasaki H. Expression of Vascular Endothelial Growth Factor by Retinal Pigment Epithelial Cells Induced by Amyloid-β Is Depressed by an Endoplasmic Reticulum Stress Inhibitor. Ophthalmic Res 2015; 55:37-44. [PMID: 26560903 DOI: 10.1159/000440885] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 09/07/2015] [Indexed: 11/19/2022]
Abstract
PURPOSE Amyloid-β (Aβ) is a 36- to 43-amino-acid peptide that is a constituent of drusen, and it has been demonstrated to upregulate vascular endothelial growth factor (VEGF) expression by retinal pigment epithelial (RPE) cells. This study aimed to determine whether 4-phenylbutyl phosphonylacetate (PBA), a known endoplasmic reticulum (ER) stress inhibitor, can reduce Aβ-induced expression of VEGF in RPE cells. METHODS Aβ was added to the medium of regularly cultured or polarized ARPE-19 cells, a human RPE cell line, with or without PBA. The levels of VEGF and ER stress markers, namely GRP78/Bip, cleaved caspases 4 and 12 and GADD153/C-EBP homologous protein, were determined by enzyme-linked immunoassay, immunocytochemistry and Western blotting. RESULTS Exposure of ARPE-19 cells to Aβ induced GRP78/Bip expression and activated caspases 4 and 12; however, their expression was decreased by simultaneous exposure to PBA. Aβ increased the expression of VEGF both in regularly cultured and polarized ARPE-19 cells, but it was suppressed by PBA. PBA did not cause RPE cell apoptosis. CONCLUSION Aβ has been suggested to be involved in the development of age-related macular degeneration; therefore, our findings suggest that drugs that target ER stress should be considered for the treatment of age-related macular degeneration.
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Affiliation(s)
- Asako Matsui
- Department of Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, Japan
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Saito RDF, Tortelli TC, Jacomassi MD, Otake AH, Chammas R. Emerging targets for combination therapy in melanomas. FEBS Lett 2015; 589:3438-48. [PMID: 26450371 DOI: 10.1016/j.febslet.2015.09.022] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Revised: 09/25/2015] [Accepted: 09/25/2015] [Indexed: 12/21/2022]
Abstract
Cutaneous melanomas are often difficult to treat when diagnosed in advanced stages. Melanoma cells adapt to survive in extreme environmental conditions and are among the tumors with larger genomic instability. Here we discuss some intrinsic and extrinsic mechanisms of resistance of melanoma cells to both conventional and target therapies, such as autophagy, adaptation to endoplasmic reticulum stress, metabolic reprogramming, mechanisms of tumor repopulation and the role of extracellular vesicles in this later phenomenon. These biological processes are potentially targetable and thus provide a platform for research and discovery of new drugs for combination therapy to manage melanoma patient treatment.
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Affiliation(s)
- Renata de Freitas Saito
- Center for Translational Research in Oncology (LIM24), Dept. of Radiology and Oncology, Faculdade de Medicina da Universidade de São Paulo and Instituto do Câncer do Estado de São Paulo, Brazil
| | - Tharcísio Citrângulo Tortelli
- Center for Translational Research in Oncology (LIM24), Dept. of Radiology and Oncology, Faculdade de Medicina da Universidade de São Paulo and Instituto do Câncer do Estado de São Paulo, Brazil
| | - Mayara D'Auria Jacomassi
- Center for Translational Research in Oncology (LIM24), Dept. of Radiology and Oncology, Faculdade de Medicina da Universidade de São Paulo and Instituto do Câncer do Estado de São Paulo, Brazil
| | - Andréia Hanada Otake
- Center for Translational Research in Oncology (LIM24), Dept. of Radiology and Oncology, Faculdade de Medicina da Universidade de São Paulo and Instituto do Câncer do Estado de São Paulo, Brazil
| | - Roger Chammas
- Center for Translational Research in Oncology (LIM24), Dept. of Radiology and Oncology, Faculdade de Medicina da Universidade de São Paulo and Instituto do Câncer do Estado de São Paulo, Brazil.
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49
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The unfolded protein response in retinal vascular diseases: implications and therapeutic potential beyond protein folding. Prog Retin Eye Res 2014; 45:111-31. [PMID: 25529848 DOI: 10.1016/j.preteyeres.2014.12.001] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Revised: 12/09/2014] [Accepted: 12/11/2014] [Indexed: 01/18/2023]
Abstract
Angiogenesis is a complex, step-wise process of new vessel formation that is involved in both normal embryonic development as well as postnatal pathological processes, such as cancer, cardiovascular disease, and diabetes. Aberrant blood vessel growth, also known as neovascularization, in the retina and the choroid is a major cause of vision loss in severe eye diseases, such as diabetic retinopathy, age-related macular degeneration, retinopathy of prematurity, and central and branch retinal vein occlusion. Yet, retinal neovascularization is causally and dynamically associated with vasodegeneration, ischemia, and vascular remodeling in retinal tissues. Understanding the mechanisms of retinal neovascularization is an urgent unmet need for developing new treatments for these devastating diseases. Accumulating evidence suggests a vital role for the unfolded protein response (UPR) in regulation of angiogenesis, in part through coordinating the secretion of pro-angiogenic growth factors, such as VEGF, and modulating endothelial cell survival and activity. Herein, we summarize current research in the context of endoplasmic reticulum (ER) stress and UPR signaling in retinal angiogenesis and vascular remodeling, highlighting potential implications of targeting these stress response pathways in the prevention and treatment of retinal vascular diseases that result in visual deficits and blindness.
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50
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Yang L, Wu L, Wang D, Li Y, Dou H, Tso MOM, Ma Z. Role of endoplasmic reticulum stress in the loss of retinal ganglion cells in diabetic retinopathy. Neural Regen Res 2014; 8:3148-58. [PMID: 25206636 PMCID: PMC4158709 DOI: 10.3969/j.issn.1673-5374.2013.33.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Accepted: 09/21/2013] [Indexed: 01/26/2023] Open
Abstract
Endoplasmic reticulum stress is closely involved in the early stage of diabetic retinopathy. In the present study, a streptozotocin-induced diabetic animal model was given an intraperitoneal injection of tauroursodeoxycholic acid. Results from immunofluorescent co-localization experiments showed that both caspase-12 protein and c-Jun N-terminal kinase 1 phosphorylation levels significantly in-creased, which was associated with retinal ganglion cell death in diabetic retinas. The C/ERB mologous protein pathway directly contributed to glial reactivity, and was subsequently responsible for neuronal loss and vascular abnormalities in diabetic retinopathy. Our experimental findings dicate that endoplasmic reticulum stress plays an important role in diabetes-induced retinal neu-ronal loss and vascular abnormalities, and that inhibiting the activation of the endoplasmic reticulum stress pathway provides effective protection against diabetic retinopathy.
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Affiliation(s)
- Liping Yang
- Department of Ophthalmology, Peking University Third Hospital, Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing 100191, China
| | - Lemeng Wu
- Department of Ophthalmology, Peking University Third Hospital, Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing 100191, China
| | - Dongmei Wang
- Department of Ophthalmology, Peking University Third Hospital, Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing 100191, China
| | - Ying Li
- Department of Ophthalmology, Peking University Third Hospital, Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing 100191, China
| | - Hongliang Dou
- Department of Ophthalmology, Peking University Third Hospital, Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing 100191, China
| | - Mark O M Tso
- Department of Ophthalmology, Peking University Third Hospital, Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing 100191, China ; Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Zhizhong Ma
- Department of Ophthalmology, Peking University Third Hospital, Key Laboratory of Vision Loss and Restoration, Ministry of Education, Beijing 100191, China
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