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Handin N, Mickols E, Ölander M, Rudfeldt J, Blom K, Nyberg F, Senkowski W, Urdzik J, Maturi V, Fryknäs M, Artursson P. Conditions for maintenance of hepatocyte differentiation and function in 3D cultures. iScience 2021; 24:103235. [PMID: 34746700 PMCID: PMC8551077 DOI: 10.1016/j.isci.2021.103235] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 08/02/2021] [Accepted: 10/04/2021] [Indexed: 12/15/2022] Open
Abstract
Spheroid cultures of primary human hepatocytes (PHH) are used in studies of hepatic drug metabolism and toxicity. The cultures are maintained under different conditions, with possible confounding results. We performed an in-depth analysis of the influence of various culture conditions to find the optimal conditions for the maintenance of an in vivo like phenotype. The formation, protein expression, and function of PHH spheroids were followed for three weeks in a high-throughput 384-well format. Medium composition affected spheroid histology, global proteome profile, drug metabolism and drug-induced toxicity. No epithelial-mesenchymal transition was observed. Media with fasting glucose and insulin levels gave spheroids with phenotypes closest to normal PHH. The most expensive medium resulted in PHH features most divergent from that of native PHH. Our results provide a protocol for culture of healthy PHH with maintained function - a prerequisite for studies of hepatocyte homeostasis and more reproducible hepatocyte research. 3D spheroid cultures were established in 384-well format Eight different media variants were used to optimize the 3D cultures Optimized William's medium was as good as expensive commercial medium The 3D cultures were used to study drug metabolism and toxicity
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Affiliation(s)
- Niklas Handin
- Department of Pharmacy, Uppsala University, 75123 Uppsala, Sweden
| | - Evgeniya Mickols
- Department of Pharmacy, Uppsala University, 75123 Uppsala, Sweden
| | - Magnus Ölander
- Department of Pharmacy, Uppsala University, 75123 Uppsala, Sweden
| | - Jakob Rudfeldt
- Department of Medical Sciences, Division of Cancer Pharmacology and Computational Medicine, Uppsala University, Uppsala, Sweden
| | - Kristin Blom
- Department of Medical Sciences, Division of Cancer Pharmacology and Computational Medicine, Uppsala University, Uppsala, Sweden
| | - Frida Nyberg
- Department of Medical Sciences, Division of Cancer Pharmacology and Computational Medicine, Uppsala University, Uppsala, Sweden
| | - Wojciech Senkowski
- Department of Medical Sciences, Division of Cancer Pharmacology and Computational Medicine, Uppsala University, Uppsala, Sweden.,Biotech Research & Innovation Centre (BRIC) and Novo Nordisk Foundation Center for Stem Cell Biology (DanStem), University of Copenhagen, 2200 Copenhagen N, Denmark
| | - Jozef Urdzik
- Department of Surgical Sciences, Uppsala University, Uppsala, Sweden
| | - Varun Maturi
- Department of Pharmacy, Uppsala University, 75123 Uppsala, Sweden
| | - Mårten Fryknäs
- Department of Medical Sciences, Division of Cancer Pharmacology and Computational Medicine, Uppsala University, Uppsala, Sweden
| | - Per Artursson
- Department of Pharmacy, Uppsala University, 75123 Uppsala, Sweden
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2
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Babalola OA, Ogunkeyede A, Odetunde AB, Fasola F, Oni AA, Babalola CP, Falusi AG. Haematological indices of sickle cell patients with chronic leg ulcers on compression therapy. Afr J Lab Med 2020; 9:1037. [PMID: 33392050 PMCID: PMC7756931 DOI: 10.4102/ajlm.v9i1.1037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 09/23/2020] [Indexed: 11/01/2022] Open
Abstract
Background Recurrent chronic leg ulcers and its are morbidities associated with sickle cell anaemia (SCA). Compression therapy increases the rate of healing of these ulcers and also decreases the rate of recurrence. Objective This study evaluated the haematological parameters of patients with SCA and chronic leg ulcers placed on high compression bandaging to provide data for improved ulcer management and prevention. Methods Eighteen patients with SCA and chronic leg ulcers were recruited for treatment by compression therapy in Ibadan, Nigeria, from March to June 2015. Eighteen SCA patients with no history of chronic leg ulcers were age and sex matched and recruited as controls. Blood samples, wound biopsies and swabs were collected at different time points for full blood count, microbiology, culture and antimicrobial susceptibility tests. Haemoglobin variants were quantified by high performance liquid chromatography. Fasting blood sugar was tested for leg ulcer patients to determine diabetic status. Results Ulcers ranged from 0.5 cm2 to 416 cm2 (median: 38.4 cm2). Post-intervention ulcer size ranged from 0.0 cm2 to 272 cm2 (median: 18.6 cm2, p < 0.001); four ulcers completely healed. Compared to the control group, haematological indices at commencement of treatment were more severe in leg ulcer patients (p = 0.02). No patients with chronic leg ulcer was diabetic. Microorganisms isolated from the leg ulcers include Pseudomonas aeruginosa, Staphylococcus aureus, Proteus sp., Escherichia coli and Klebsiella oxytoca. Conclusion Measures to improve haematological parameters during leg ulcer treatment in SCA patients should be taken to aid wound healing.
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Affiliation(s)
- Oluwatoyin A Babalola
- Institute for Advanced Medical Research and Training, College of Medicine, University of Ibadan, Ibadan, Nigeria
| | - Ayodele Ogunkeyede
- Department of Surgery, University of Ilorin Teaching Hospital, Ilorin, Kwara State, Nigeria
| | - Abayomi B Odetunde
- Institute for Advanced Medical Research and Training, College of Medicine, University of Ibadan, Ibadan, Nigeria
| | - Foluke Fasola
- Department of Haematology, College of Medicine, University of Ibadan, Ibadan, Nigeria
| | - Anthony A Oni
- Department of Medical Microbiology, College of Medicine, University of Ibadan, Ibadan, Nigeria
| | - Chinedum P Babalola
- Institute for Advanced Medical Research and Training, College of Medicine, University of Ibadan, Ibadan, Nigeria.,Sickle Cell Hope Alive Foundation (SCHAF), Nigeria
| | - Adeyinka G Falusi
- Institute for Advanced Medical Research and Training, College of Medicine, University of Ibadan, Ibadan, Nigeria.,Sickle Cell Hope Alive Foundation (SCHAF), Nigeria
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Sun XJ, Chen M, Zhao MH. Thrombin Contributes to Anti-myeloperoxidase Antibody Positive IgG-Mediated Glomerular Endothelial Cells Activation Through SphK1-S1P-S1PR3 Signaling. Front Immunol 2019; 10:237. [PMID: 30891029 PMCID: PMC6413724 DOI: 10.3389/fimmu.2019.00237] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Accepted: 01/28/2019] [Indexed: 12/15/2022] Open
Abstract
Background: Activation of coagulation system plays an important role in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) pathogenesis. Thrombin, generated during coagulation could disrupt endothelial barrier integrity through protease-activated receptor 1 (PAR1). Our previous study found that sphingosine-1-phosphate (S1P) contributed to myeloperoxidase (MPO)-ANCA-positive IgG-induced glomerular endothelial cell (GEnC) activation through a S1P receptor (S1PR)-dependent route. In recent years, S1P signaling was reported to be involved in thrombin effects on endothelial cells. This current study investigated whether the interaction between thrombin-PAR and S1P-S1PR signaling contributed to MPO-ANCA-positive IgG-induced GEnC dysfunction. Methods: The effect of thrombin on GEnC activation was analyzed from three aspects. First, morphological alteration of GEnCs was observed. Second, permeability assay was performed to determine GEnC monolayer activation quantitatively. Third, endothelin-1 (ET-1) levels were measured. Expression levels of sphingosine kinases (SphKs) and S1PRs were detected. In addition, antagonists of PAR1 and S1PR3 were employed to determine their roles. Eventually, PAR1 and tissue factor (TF) expression levels as well as TF procoagulant activity were analyzed. Results: Thrombin induced further damage of tight junction, increase in endothelial monolayer permeability as well as upregulation of ET-1 levels in GEnCs stimulated with MPO-ANCA-positive IgG. Blocking PAR1 downregulated ET-1 levels in the supernatants of GEnCs treated by thrombin plus MPO-ANCA-positive IgG. Expression levels of SphK1, S1PR3 increased significantly in GEnCs treated with thrombin plus MPO-ANCA-positive IgG. S1P upregulated PAR1 and TF expression, and enhanced procoagulant activity of TF in MPO-ANCA-positive IgG-stimulated GEnCs. Conclusion: Thrombin synergized with SphK1-S1P-S1PR3 signaling pathway to enhance MPO-ANCA-positive IgG-mediated GEnC activation.
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Affiliation(s)
- Xiao-Jing Sun
- Renal Division, Department of Medicine, Peking University, First Hospital, Peking University Institute of Nephrology, Beijing, China
| | - Min Chen
- Renal Division, Department of Medicine, Peking University, First Hospital, Peking University Institute of Nephrology, Beijing, China.,Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China
| | - Ming-Hui Zhao
- Renal Division, Department of Medicine, Peking University, First Hospital, Peking University Institute of Nephrology, Beijing, China.,Key Laboratory of Renal Disease, Ministry of Health of China, Beijing, China.,Key Laboratory of Chronic Kidney Disease Prevention and Treatment, Ministry of Education, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
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4
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Chen Q, Weng HY, Tang XP, Lin Y, Yuan Y, Li Q, Tang Z, Wu HB, Yang S, Li Y, Zhao XL, Fu WJ, Niu Q, Feng H, Zhang X, Wang Y, Bian XW, Yao XH. ARL4C stabilized by AKT/mTOR pathway promotes the invasion of PTEN-deficient primary human glioblastoma. J Pathol 2018; 247:266-278. [PMID: 30357833 DOI: 10.1002/path.5189] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2018] [Revised: 09/04/2018] [Accepted: 10/18/2018] [Indexed: 12/16/2022]
Abstract
Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) deficiency in primary human glioblastoma (GBM) is associated with increased invasiveness and poor prognosis with unknown mechanisms. Therefore, how loss of PTEN promotes GBM progression remains to be elucidated. Herein, we identified that ADP-ribosylation factor like-4C (ARL4C) was highly expressed in PTEN-deficient human GBM cells and tissues. Mechanistically, loss of PTEN stabilized ARL4C protein due to AKT/mTOR pathway-mediated inhibition of ARL4C ubiquitination. Functionally, ARL4C enhanced the progression of GBM cells in vitro and in vivo. Moreover, microarray profiling and GST pull-down assay identified that ARL4C accelerated tumor progression via RAC1-mediated filopodium formation. Importantly, targeting PTEN potently inhibited GBM tumor progression in vitro and in vivo, whereas overexpression of ARL4C reversed the tumor progression impaired by PTEN overexpression. Clinically, analyses with patients' specimens validated a negative correlation between PTEN and ARL4C expression. Elevated ARL4C expression but PTEN deficiency in tumor was associated with poorer disease-free survival and overall survival of GBM patients. Taken together, ARL4C is critical for PTEN-deficient GBM progression and acts as a novel prognostic biomarker and a potential therapeutic candidate. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
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Affiliation(s)
- Qian Chen
- Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, PR China
| | - Hai-Yan Weng
- Department of Pathology, The Affiliated Provincial Hospital, Anhui Medical University, Hefei, PR China
| | - Xiao-Peng Tang
- Department of Nephrology, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, PR China
| | - Yong Lin
- Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, PR China
| | - Ye Yuan
- Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, PR China
| | - Qian Li
- Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, PR China
| | - Zhuo Tang
- Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, PR China
| | - Hai-Bo Wu
- Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, PR China
| | - Shuai Yang
- Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, PR China
| | - Yong Li
- Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, PR China
| | - Xi-Long Zhao
- Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, PR China
| | - Wen-Juan Fu
- Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, PR China
| | - Qin Niu
- Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, PR China
| | - Hua Feng
- Department of Neurosurgery, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, PR China
| | - Xia Zhang
- Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, PR China
| | - Yan Wang
- Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, PR China
| | - Xiu-Wu Bian
- Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, PR China
| | - Xiao-Hong Yao
- Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, PR China
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Kuck JL, Bastarache JA, Shaver CM, Fessel JP, Dikalov SI, May JM, Ware LB. Ascorbic acid attenuates endothelial permeability triggered by cell-free hemoglobin. Biochem Biophys Res Commun 2018; 495:433-437. [PMID: 29129689 PMCID: PMC5736437 DOI: 10.1016/j.bbrc.2017.11.058] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 11/08/2017] [Indexed: 01/09/2023]
Abstract
BACKGROUND Increased endothelial permeability is central to shock and organ dysfunction in sepsis but therapeutics targeted to known mediators of increased endothelial permeability have been unsuccessful in patient studies. We previously reported that cell-free hemoglobin (CFH) is elevated in the majority of patients with sepsis and is associated with organ dysfunction, poor clinical outcomes and elevated markers of oxidant injury. Others have shown that Vitamin C (ascorbate) may have endothelial protective effects in sepsis. In this study, we tested the hypothesis that high levels of CFH, as seen in the circulation of patients with sepsis, disrupt endothelial barrier integrity. METHODS Human umbilical vein endothelial cells (HUVEC) were grown to confluence and treated with CFH with or without ascorbate. Monolayer permeability was measured by Electric Cell-substrate Impedance Sensing (ECIS) or transfer of 14C-inulin. Viability was measured by trypan blue exclusion. Intracellular ascorbate was measured by HPLC. RESULTS CFH increased permeability in a dose- and time-dependent manner with 1 mg/ml of CFH increasing inulin transfer by 50% without affecting cell viability. CFH (1 mg/ml) also caused a dramatic reduction in intracellular ascorbate in the same time frame (1.4 mM without CFH, 0.23 mM 18 h after 1 mg/ml CFH, p < 0.05). Pre-treatment of HUVECs with ascorbate attenuated CFH induced permeability. CONCLUSIONS CFH increases endothelial permeability in part through depletion of intracellular ascorbate. Supplementation of ascorbate can attenuate increases in permeability mediated by CFH suggesting a possible therapeutic approach in sepsis.
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Affiliation(s)
- Jamie L. Kuck
- Division of Allergy, Pulmonary and Critical Care Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
| | - Julie A. Bastarache
- Division of Allergy, Pulmonary and Critical Care Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN,Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN
| | - Ciara M. Shaver
- Division of Allergy, Pulmonary and Critical Care Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
| | - Joshua P. Fessel
- Division of Allergy, Pulmonary and Critical Care Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN,Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN
| | - Sergey I. Dikalov
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN
| | - James M. May
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
| | - Lorraine B. Ware
- Division of Allergy, Pulmonary and Critical Care Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN,Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN,Corresponding author: Lorraine B. Ware, MD, Professor of Medicine and Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, 1161 21st Avenue South, T1218 MCN, Nashville, TN 37232,
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6
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Parthasarathi K. The Pulmonary Vascular Barrier: Insights into Structure, Function, and Regulatory Mechanisms. MOLECULAR AND FUNCTIONAL INSIGHTS INTO THE PULMONARY VASCULATURE 2018; 228:41-61. [DOI: 10.1007/978-3-319-68483-3_3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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7
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Anti-inflammatory mechanism of ulinastatin: Inhibiting the hyperpermeability of vascular endothelial cells induced by TNF-α via the RhoA/ROCK signal pathway. Int Immunopharmacol 2017; 46:220-227. [DOI: 10.1016/j.intimp.2017.03.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 03/06/2017] [Indexed: 12/11/2022]
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8
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Parker WH, Rhea EM, Qu ZC, Hecker MR, May JM. Intracellular ascorbate tightens the endothelial permeability barrier through Epac1 and the tubulin cytoskeleton. Am J Physiol Cell Physiol 2016; 311:C652-C662. [PMID: 27605450 DOI: 10.1152/ajpcell.00076.2016] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 08/21/2016] [Indexed: 12/28/2022]
Abstract
Vitamin C, or ascorbic acid, both tightens the endothelial permeability barrier in basal cells and also prevents barrier leak induced by inflammatory agents. Barrier tightening by ascorbate in basal endothelial cells requires nitric oxide derived from activation of nitric oxide synthase. Although ascorbate did not affect cyclic AMP levels in our previous study, there remains a question of whether it might activate downstream cyclic AMP-dependent pathways. In this work, we found in both primary and immortalized cultured endothelial cells that ascorbate tightened the endothelial permeability barrier by ∼30%. In human umbilical vein endothelial cells, this occurred at what are likely physiologic intracellular ascorbate concentrations. In so doing, ascorbate decreased measures of oxidative stress and also flattened the cells to increase cell-to-cell contact. Inhibition of downstream cyclic AMP-dependent proteins via protein kinase A did not prevent ascorbate from tightening the endothelial permeability barrier, whereas inhibition of Epac1 did block the ascorbate effect. Although Epac1 was required, its mediator Rap1 was not activated. Furthermore, ascorbate acutely stabilized microtubules during depolymerization induced by colchicine and nocodazole. Over several days in culture, ascorbate also increased the amount of stable acetylated α-tubulin. Microtubule stabilization was further suggested by the finding that ascorbate increased the amount of Epac1 bound to α-tubulin. These results suggest that physiologic ascorbate concentrations tighten the endothelial permeability barrier in unstimulated cells by stabilizing microtubules in a manner downstream of cyclic AMP that might be due both to increasing nitric oxide availability and to scavenging of reactive oxygen or nitrogen species.
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Affiliation(s)
- William H Parker
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee; and
| | - Elizabeth Meredith Rhea
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Zhi-Chao Qu
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee; and
| | - Morgan R Hecker
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee; and
| | - James M May
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, Tennessee; and
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Yuan S, Pardue S, Shen X, Alexander JS, Orr AW, Kevil CG. Hydrogen sulfide metabolism regulates endothelial solute barrier function. Redox Biol 2016; 9:157-166. [PMID: 27552214 PMCID: PMC4993857 DOI: 10.1016/j.redox.2016.08.004] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 08/03/2016] [Accepted: 08/10/2016] [Indexed: 12/14/2022] Open
Abstract
Hydrogen sulfide (H2S) is an important gaseous signaling molecule in the cardiovascular system. In addition to free H2S, H2S can be oxidized to polysulfide which can be biologically active. Since the impact of H2S on endothelial solute barrier function is not known, we sought to determine whether H2S and its various metabolites affect endothelial permeability. In vitro permeability was evaluated using albumin flux and transendothelial electrical resistance. Different H2S donors were used to examine the effects of exogenous H2S. To evaluate the role of endogenous H2S, mouse aortic endothelial cells (MAECs) were isolated from wild type mice and mice lacking cystathionine γ-lyase (CSE), a predominant source of H2S in endothelial cells. In vivo permeability was evaluated using the Miles assay. We observed that polysulfide donors induced rapid albumin flux across endothelium. Comparatively, free sulfide donors increased permeability only with higher concentrations and at later time points. Increased solute permeability was associated with disruption of endothelial junction proteins claudin 5 and VE-cadherin, along with enhanced actin stress fiber formation. Importantly, sulfide donors that increase permeability elicited a preferential increase in polysulfide levels within endothelium. Similarly, CSE deficient MAECs showed enhanced solute barrier function along with reduced endogenous bound sulfane sulfur. CSE siRNA knockdown also enhanced endothelial junction structures with increased claudin 5 protein expression. In vivo, CSE genetic deficiency significantly blunted VEGF induced hyperpermeability revealing an important role of the enzyme for barrier function. In summary, endothelial solute permeability is critically regulated via exogenous and endogenous sulfide bioavailability with a prominent role of polysulfides. Polysulfide from cystathionine γ-lyase (CSE) and exogenous polysulfide donors increases endothelial permeability. The ability of polysulfide to increase permeability is associated with junction disruption and stress fiber formation. CSE expression in vivo regulates VEGF induced hyper-permeability.
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Affiliation(s)
- Shuai Yuan
- Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences Center, Shreveport, LA 71103, USA
| | - Sibile Pardue
- Department of Pathology, Louisiana State University Health Sciences Center, Shreveport, LA 71103, USA
| | - Xinggui Shen
- Department of Pathology, Louisiana State University Health Sciences Center, Shreveport, LA 71103, USA
| | - J Steven Alexander
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, Shreveport, LA 71103, USA
| | - A Wayne Orr
- Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences Center, Shreveport, LA 71103, USA; Department of Pathology, Louisiana State University Health Sciences Center, Shreveport, LA 71103, USA
| | - Christopher G Kevil
- Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences Center, Shreveport, LA 71103, USA; Department of Pathology, Louisiana State University Health Sciences Center, Shreveport, LA 71103, USA; Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center, Shreveport, LA 71103, USA; Center for Cardiovascular Diseases and Sciences, Louisiana State University Health Sciences Center, Shreveport, LA 71103, USA.
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10
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May JM. Ascorbic acid repletion: A possible therapy for diabetic macular edema? Free Radic Biol Med 2016; 94:47-54. [PMID: 26898503 PMCID: PMC4844774 DOI: 10.1016/j.freeradbiomed.2016.02.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 02/10/2016] [Accepted: 02/16/2016] [Indexed: 02/07/2023]
Abstract
Macular edema poses a significant risk for visual loss in persons with diabetic retinopathy. It occurs when plasma constituents and fluid leak out of damaged retinal microvasculature in the area of the macula, causing loss of central vision. Apoptotic loss of pericytes surrounding capillaries is perhaps the earliest feature of diabetic vascular damage in the macula, which is also associated with dysfunction of the endothelium and loss of the otherwise very tight endothelial permeability barrier. Increased oxidative stress is a key feature of damage to both cell types, mediated by excess superoxide from glucose-induced increases in mitochondrial metabolism, as well as by activation of the receptor for advanced glycation end products (RAGE). The latter in turn activates multiple pathways, some of which lead to increased oxidative stress, such as those involving NF-ĸB, NADPH oxidase, and endothelial nitric oxide synthase. Such cellular oxidative stress is associated with low cellular and plasma ascorbic acid levels in many subjects with diabetes in poor glycemic control. Whether repletion of low ascorbate in retinal endothelium and pericytes might help to prevent diabetic macular edema is unknown. However, cell culture studies show that the vitamin prevents high-glucose and RAGE-induced apoptosis in both cell types, that it preserves nitric oxide generated by endothelial cells, and that it tightens the leaky endothelial permeability barrier. Although these findings need to be confirmed in pre-clinical animal studies, it is worth considering clinical trials to determine whether adequate ascorbate repletion is possible and whether it might help to delay or even reverse early diabetic macular edema.
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Affiliation(s)
- James M May
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN 37232-6303, United States.
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11
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Ulker E, Parker WH, Raj A, Qu ZC, May JM. Ascorbic acid prevents VEGF-induced increases in endothelial barrier permeability. Mol Cell Biochem 2015; 412:73-9. [PMID: 26590088 DOI: 10.1007/s11010-015-2609-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Accepted: 11/14/2015] [Indexed: 02/07/2023]
Abstract
Vascular endothelial growth factor (VEGF) increases endothelial barrier permeability, an effect that may contribute to macular edema in diabetic retinopathy. Since vitamin C, or ascorbic acid, can tighten the endothelial permeability barrier, we examined whether it could prevent the increase in permeability due to VEGF in human umbilical vein endothelial cells (HUVECs). As previously observed, VEGF increased HUVEC permeability to radiolabeled inulin within 60 min in a concentration-dependent manner. Loading the cells with increasing concentrations of ascorbate progressively prevented the leakage caused by 100 ng/ml VEGF, with a significant inhibition at 13 µM and complete inhibition at 50 µM. Loading cells with 100 µM ascorbate also decreased the basal generation of reactive oxygen species and prevented the increase caused by both 100 ng/ml VEGF. VEGF treatment decreased intracellular ascorbate by 25%, thus linking ascorbate oxidation to its prevention of VEGF-induced barrier leakage. The latter was blocked by treating the cells with 60 µM L-NAME (but not D-NAME) as well as by 30 µM sepiapterin, a precursor of tetrahydrobiopterin that is required for proper function of endothelial nitric oxide synthase (eNOS). These findings suggest that VEGF-induced barrier leakage uncouples eNOS. Ascorbate inhibition of the VEGF effect could thus be due either to scavenging superoxide or to peroxynitrite generated by the uncoupled eNOS, or more likely to its ability to recycle tetrahydrobiopterin, thus avoiding enzyme uncoupling in the first place. Ascorbate prevention of VEGF-induced increases in endothelial permeability opens the possibility that its repletion could benefit diabetic macular edema.
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Affiliation(s)
- Esad Ulker
- Department of Medicine, Vanderbilt University School of Medicine, 7465 Medical Research Building IV, Nashville, TN, 37232-0475, USA
| | - William H Parker
- Department of Medicine, Vanderbilt University School of Medicine, 7465 Medical Research Building IV, Nashville, TN, 37232-0475, USA
| | - Amita Raj
- Department of Medicine, Vanderbilt University School of Medicine, 7465 Medical Research Building IV, Nashville, TN, 37232-0475, USA
| | - Zhi-chao Qu
- Department of Medicine, Vanderbilt University School of Medicine, 7465 Medical Research Building IV, Nashville, TN, 37232-0475, USA
| | - James M May
- Department of Medicine, Vanderbilt University School of Medicine, 7465 Medical Research Building IV, Nashville, TN, 37232-0475, USA.
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