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Gurubaran IS. Mitochondrial damage and clearance in retinal pigment epithelial cells. Acta Ophthalmol 2024; 102 Suppl 282:3-53. [PMID: 38467968 DOI: 10.1111/aos.16661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Accepted: 01/31/2024] [Indexed: 03/13/2024]
Abstract
Age-related macular degeneration (AMD) is a devastating eye disease that causes permanent vision loss in the central part of the retina, known as the macula. Patients with such severe visual loss face a reduced quality of life and are at a 1.5 times greater risk of death compared to the general population. Currently, there is no cure for or effective treatment for dry AMD. There are several mechanisms thought to underlie the disease, for example, ageing-associated chronic oxidative stress, mitochondrial damage, harmful protein aggregation and inflammation. As a way of gaining a better understanding of the molecular mechanisms behind AMD and thus developing new therapies, we have created a peroxisome proliferator-activated receptor gamma coactivator 1-alpha and nuclear factor erythroid 2-related factor 2 (PGC1α/NFE2L2) double-knockout (dKO) mouse model that mimics many of the clinical features of dry AMD, including elevated levels of oxidative stress markers, damaged mitochondria, accumulating lysosomal lipofuscin and extracellular drusen-like structures in retinal pigment epithelial cells (RPE). In addition, a human RPE cell-based model was established to examine the impact of non-functional intracellular clearance systems on inflammasome activation. In this study, we found that there was a disturbance in the autolysosomal machinery responsible for clearing mitochondria in the RPE cells of one-year-old PGC1α/NFE2L2-deficient mice. The confocal immunohistochemical analysis revealed an increase in autophagosome marker microtubule-associated proteins 1A/1B light chain 3B (LC3B) as well as multiple mitophagy markers such as PTE-induced putative kinase 1 (PINK1) and E3 ubiquitin ligase (PARKIN), along with signs of damaged mitochondria. However, no increase in autolysosome formation was detected, nor was there a colocalization of the lysosomal marker LAMP2 or the mitochondrial marker, ATP synthase β. There was an upregulation of late autolysosomal fusion Ras-related protein (Rab7) in the perinuclear space of RPE cells, together with autofluorescent aggregates. Additionally, we observed an increase in the numbers of Toll-like receptors 3 and 9, while those of NOD-like receptor 3 were decreased in PGC1α/NFE2L2 dKO retinal specimens compared to wild-type animals. There was a trend towards increased complement component C5a and increased involvement of the serine protease enzyme, thrombin, in enhancing the terminal pathway producing C5a, independent of C3. The levels of primary acute phase C-reactive protein and receptor for advanced glycation end products were also increased in the PGC1α/NFE2L2 dKO retina. Furthermore, selective proteasome inhibition with epoxomicin promoted both nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and mitochondrial-mediated oxidative stress, leading to the release of mitochondrial DNA to the cytosol, resulting in potassium efflux-dependent activation of the absent in melanoma 2 (AIM2) inflammasome and the subsequent secretion of interleukin-1β in ARPE-19 cells. In conclusion, the data suggest that there is at least a relative decrease in mitophagy, increases in the amounts of C5 and thrombin and decreased C3 levels in this dry AMD-like model. Moreover, selective proteasome inhibition evoked mitochondrial damage and AIM2 inflammasome activation in ARPE-19 cells.
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Affiliation(s)
- Iswariyaraja Sridevi Gurubaran
- Department of Medicine, Clinical Medicine Unit, University of Eastern Finland Institute of Clinical Medicine, Kuopio, Northern Savonia, Finland
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2
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Oxidative Stress and Mitochondrial Damage in Dry Age-Related Macular Degeneration Like NFE2L2/PGC-1α -/- Mouse Model Evoke Complement Component C5a Independent of C3. BIOLOGY 2021; 10:biology10070622. [PMID: 34356477 PMCID: PMC8301195 DOI: 10.3390/biology10070622] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 06/30/2021] [Accepted: 07/02/2021] [Indexed: 11/16/2022]
Abstract
Aging-associated chronic oxidative stress and inflammation are known to be involved in various diseases, e.g., age-related macular degeneration (AMD). Previously, we reported the presence of dry AMD-like signs, such as elevated oxidative stress, dysfunctional mitophagy and the accumulation of detrimental oxidized materials in the retinal pigment epithelial (RPE) cells of nuclear factor erythroid 2-related factor 2, and a peroxisome proliferator-activated receptor gamma coactivator 1-alpha (NFE2L2/PGC1α) double knockout (dKO) mouse model. Here, we investigated the dynamics of inflammatory markers in one-year-old NFE2L2/PGC1α dKO mice. Immunohistochemical analysis revealed an increase in levels of Toll-like receptors 3 and 9, while those of NOD-like receptor 3 were decreased in NFE2L2/PGC1α dKO retinal specimens as compared to wild type animals. Further analysis showed a trend towards an increase in complement component C5a independent of component C3, observed to be tightly regulated by complement factor H. Interestingly, we found that thrombin, a serine protease enzyme, was involved in enhancing the terminal pathway producing C5a, independent of C3. We also detected an increase in primary acute phase C-reactive protein and receptor for advanced glycation end products in NFE2L2/PGC1α dKO retina. Our main data show C5 and thrombin upregulation together with decreased C3 levels in this dry AMD-like model. In general, the retina strives to mount an orchestrated inflammatory response while attempting to maintain tissue homeostasis and resolve inflammation.
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Liu Y, Mo CF, Luo XY, Li H, Guo HJ, Sun H, Hu S, Li LM, Wang YT, Yang SX, Chang S, Zou Q. Activation of Toll-Like Receptor 3 Induces Interleukin-1 Receptor Antagonist Expression by Activating the Interferon Regulatory Factor 3. J Innate Immun 2019; 12:304-320. [PMID: 31865314 DOI: 10.1159/000504321] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 10/21/2019] [Indexed: 12/16/2022] Open
Abstract
Toll-like receptor 3 (TLR3) is a sensor of endogenous cell necrosis during the process of acute inflammation. Interleukin (IL)-1 receptor antagonist (IL-1Ra) is an anti-inflammatory cytokine and can negatively regulate the pathogenesis of inflammation. However, whether and how activation of TLR3 can regulate IL-1Ra expression has not been clarified. Here, we show that poly(I:C) induces IL-1Ra expression in primarily cultured human fibroblast-like synoviocytes and other types of cells. Induction of IL-1Ra by poly(I:C) was dependent on TLR3, but was independent of melanoma differentiation--associated protein 5 or retinoic acid-inducible gene I. Interferon regulatory factor 3 (IRF3) directly binds to the IL-1Ra promoter and promotes IL-1Ra expression in response to poly(I:C) stimulation. Induction of IL-1Ra by poly(I:C) was abolished by the inhibition of the NF-κB signaling, attenuated by the inhibition of the PI3K-Akt signaling, enhanced by inhibition of the ERK1/2 or MSK1/2 activation, but was independent of the p38 MAPK signaling. Treatment with poly(I:C) or Sendai virus elevated the levels of serum IL-1Ra in wild-type, but not in TLR3-/- or IRF3-/- mice. Our findings may provide new insights into the intrinsic anti-inflammatory function of TLR3 and double-stranded RNA-induced IL-Ra expression by TLR3 and its regulation.
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Affiliation(s)
- Yang Liu
- Department of Immunology, School of Basic Medical Sciences, Chengdu Medical College, Chengdu, China.,Center of Science and Research, Chengdu Medical College, Chengdu, China
| | - Chun-Fen Mo
- Department of Immunology, School of Basic Medical Sciences, Chengdu Medical College, Chengdu, China.,Center of Science and Research, Chengdu Medical College, Chengdu, China
| | - Xing-Yan Luo
- Department of Immunology, School of Basic Medical Sciences, Chengdu Medical College, Chengdu, China.,Center of Science and Research, Chengdu Medical College, Chengdu, China
| | - Hua Li
- Cancer Center, Chengdu Military General Hospital, Chengdu, China
| | - Hui-Jie Guo
- Department of Immunology, School of Basic Medical Sciences, Chengdu Medical College, Chengdu, China.,Center of Science and Research, Chengdu Medical College, Chengdu, China
| | - Hai Sun
- Department of Immunology, School of Basic Medical Sciences, Chengdu Medical College, Chengdu, China.,Center of Science and Research, Chengdu Medical College, Chengdu, China
| | - Song Hu
- Department of Immunology, School of Basic Medical Sciences, Chengdu Medical College, Chengdu, China.,Center of Science and Research, Chengdu Medical College, Chengdu, China
| | - Li-Mei Li
- Department of Immunology, School of Basic Medical Sciences, Chengdu Medical College, Chengdu, China.,Center of Science and Research, Chengdu Medical College, Chengdu, China
| | - Yan-Tang Wang
- Department of Immunology, School of Basic Medical Sciences, Chengdu Medical College, Chengdu, China.,Center of Science and Research, Chengdu Medical College, Chengdu, China
| | - Shu-Xia Yang
- Department of Immunology, School of Basic Medical Sciences, Chengdu Medical College, Chengdu, China.,Center of Science and Research, Chengdu Medical College, Chengdu, China
| | - Shan Chang
- Department of Orthopedics, First Teaching Hospital, Chengdu Medical College, Chengdu, China
| | - Qiang Zou
- Department of Immunology, School of Basic Medical Sciences, Chengdu Medical College, Chengdu, China, .,Center of Science and Research, Chengdu Medical College, Chengdu, China,
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McCarthy GM, Bridges CR, Blednov YA, Harris RA. CNS cell-type localization and LPS response of TLR signaling pathways. F1000Res 2017; 6:1144. [PMID: 29043065 PMCID: PMC5621151 DOI: 10.12688/f1000research.12036.1] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/17/2017] [Indexed: 12/15/2022] Open
Abstract
Background: Innate immune signaling in the brain has emerged as a contributor to many central nervous system (CNS) pathologies, including mood disorders, neurodegenerative disorders, neurodevelopmental disorders, and addiction. Toll-like receptors (TLRs), a key component of the innate immune response, are particularly implicated in neuroimmune dysfunction. However, most of our understanding about TLR signaling comes from the peripheral immune response, and it is becoming clear that the CNS immune response is unique. One controversial aspect of neuroimmune signaling is which CNS cell types are involved. While microglia are the CNS cell-type derived from a myeloid lineage, studies suggest that other glial cell types and even neurons express TLRs, although this idea is controversial. Furthermore, recent work suggests a discrepancy between RNA and protein expression within the CNS. Methods: To elucidate the CNS cell-type localization of TLRs and their downstream signaling molecules, we isolated microglia and astrocytes from the brain of adult mice treated with saline or the TLR4 ligand lipopolysaccharide (LPS). Glial mRNA and protein expression was compared to a cellular-admixture to determine cell-type enrichment. Results: Enrichment analysis revealed that most of the TLR pathway genes are localized in microglia and changed in microglia following immune challenge. However, expression of
Tlr3 was enriched in astrocytes, where it increased in response to LPS. Furthermore, attempts to determine protein cell-type localization revealed that many antibodies are non-specific and that antibody differences are contributing to conflicting localization results. Conclusions: Together these results highlight the cell types that should be looked at when studying TLR signaling gene expression and suggest that non-antibody approaches need to be used to accurately evaluate protein expression.
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Affiliation(s)
- Gizelle M McCarthy
- Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX, 78712, USA.,Waggoner Center for Alcohol and Addiction Research, University of Texas at Austin, Austin, TX, 78712, USA
| | - Courtney R Bridges
- Waggoner Center for Alcohol and Addiction Research, University of Texas at Austin, Austin, TX, 78712, USA
| | - Yuri A Blednov
- Waggoner Center for Alcohol and Addiction Research, University of Texas at Austin, Austin, TX, 78712, USA
| | - R Adron Harris
- Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX, 78712, USA.,Waggoner Center for Alcohol and Addiction Research, University of Texas at Austin, Austin, TX, 78712, USA.,Insitute for Neuroscience, University of Texas at Austin, Austin, TX, 78712, USA
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Li Y, Xu XL, Zhao D, Pan LN, Huang CW, Guo LJ, Lu Q, Wang J. TLR3 ligand Poly IC Attenuates Reactive Astrogliosis and Improves Recovery of Rats after Focal Cerebral Ischemia. CNS Neurosci Ther 2016; 21:905-13. [PMID: 26494128 DOI: 10.1111/cns.12469] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Revised: 09/06/2015] [Accepted: 09/13/2015] [Indexed: 01/08/2023] Open
Abstract
AIMS Brain ischemia activates astrocytes in a process known as astrogliosis. Although this process has beneficial effects, excessive astrogliosis can impair neuronal recovery. Polyinosinic-polycytidylic acid (Poly IC) has shown neuroprotection against cerebral ischemia-reperfusion injury, but whether it regulates reactive astrogliosis and glial scar formation is not clear. METHODS We exposed cultured astrocytes to oxygen-glucose deprivation/reoxygenation (OGD/R) and used a rat middle cerebral artery occlusion (MCAO)/reperfusion model to investigate the effects of Poly IC. Astrocyte proliferation and proliferation-related molecules were evaluated by immunostaining and Western blotting. Neurological deficit scores, infarct volumes and neuroplasticity were evaluated in rats after transient MCAO. RESULTS In vitro, Poly IC inhibited astrocyte proliferation, upregulated Toll-like receptor 3 (TLR3) expression, upregulated interferon-β, and downregulated interleukin-6 production. These changes were blocked by a neutralizing antibody against TLR3, suggesting that Poly IC function is TLR3-dependent. Moreover, in the MCAO model, Poly IC attenuated reactive astrogliosis, reduced brain infarction volume, and improved neurological function. In addition, Poly IC prevented MCAO-induced reductions in soma size, dendrite length, and number of dendritic bifurcations in cortical neurons of the infarct penumbra. CONCLUSIONS By ameliorating astrogliosis-related damage, Poly IC is a potential therapeutic agent for attenuating neuronal damage and promoting recovery after brain ischemia.
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Affiliation(s)
- Yang Li
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xu-Lin Xu
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,The Key Laboratory for Drug Target Research and Pharmacodynamic Evaluation of Hubei Province, Wuhan, China
| | - Dan Zhao
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Lin-Na Pan
- Medical Department of Neurology, The Second Hospital of Nanchang, Nanchang, China
| | - Chun-Wei Huang
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Lian-Jun Guo
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,The Key Laboratory for Drug Target Research and Pharmacodynamic Evaluation of Hubei Province, Wuhan, China
| | - Qing Lu
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,The Key Laboratory for Drug Target Research and Pharmacodynamic Evaluation of Hubei Province, Wuhan, China
| | - Jian Wang
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
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Pan LN, Zhu W, Li Y, Xu XL, Guo LJ, Lu Q, Wang J. Astrocytic Toll-like receptor 3 is associated with ischemic preconditioning-induced protection against brain ischemia in rodents. PLoS One 2014; 9:e99526. [PMID: 24914679 PMCID: PMC4051824 DOI: 10.1371/journal.pone.0099526] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 05/15/2014] [Indexed: 11/18/2022] Open
Abstract
Background Cerebral ischemic preconditioning (IPC) protects brain against ischemic injury. Activation of Toll-like receptor 3 (TLR3) signaling can induce neuroprotective mediators, but whether astrocytic TLR3 signaling is involved in IPC-induced ischemic tolerance is not known. Methods IPC was modeled in mice with three brief episodes of bilateral carotid occlusion. In vitro, IPC was modeled in astrocytes by 1-h oxygen-glucose deprivation (OGD). Injury and components of the TLR3 signaling pathway were measured after a subsequent protracted ischemic event. A neutralizing antibody against TLR3 was used to evaluate the role of TLR3 signaling in ischemic tolerance. Results IPC in vivo reduced brain damage from permanent middle cerebral artery occlusion in mice and increased expression of TLR3 in cortical astrocytes. IPC also reduced damage in isolated astrocytes after 12-h OGD. In astrocytes, IPC or 12-h OGD alone increased TLR3 expression, and 12-h OGD alone increased expression of phosphorylated NFκB (pNFκB). However, IPC or 12-h OGD alone did not alter the expression of Toll/interleukin receptor domain-containing adaptor-inducing IFNβ (TRIF) or phosphorylated interferon regulatory factor 3 (pIRF3). Exposure to IPC before OGD increased TRIF and pIRF3 expression but decreased pNFκB expression. Analysis of cytokines showed that 12-h OGD alone increased IFNβ and IL-6 secretion; 12-h OGD preceded by IPC further increased IFNβ secretion but decreased IL-6 secretion. Preconditioning with TLR3 ligand Poly I:C increased pIRF3 expression and protected astrocytes against ischemic injury; however, cells treated with a neutralizing antibody against TLR3 lacked the IPC- and Poly I:C-induced ischemic protection and augmentation of IFNβ. Conclusions The results suggest that IPC-induced ischemic tolerance is mediated by astrocytic TLR3 signaling. This reprogramming of TLR3 signaling by IPC in astrocytes may play an important role in suppression of the post-ischemic inflammatory response and thereby protect against ischemic damage. The mechanism may be via activation of the TLR3/TRIF/IRF3 signaling pathway.
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Affiliation(s)
- Lin-na Pan
- Department of Pharmacology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
- Medical Department of Neurology, The Second Hospital of Nanchang, Nanchang, Jiangxi, People's Republic of China
| | - Wei Zhu
- Department of Emergency Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, Maryland, United States of America
| | - Yang Li
- Department of Pharmacology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
| | - Xu-lin Xu
- Department of Pharmacology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
- The Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation, Hubei Province, Wuhan, Hubei, People's Republic of China
| | - Lian-jun Guo
- Department of Pharmacology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
- The Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation, Hubei Province, Wuhan, Hubei, People's Republic of China
| | - Qing Lu
- Department of Pharmacology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, People's Republic of China
- The Key Laboratory of Drug Target Research and Pharmacodynamic Evaluation, Hubei Province, Wuhan, Hubei, People's Republic of China
- * E-mail:
| | - Jian Wang
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, Maryland, United States of America
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Defects in TLR3 expression and RNase L activation lead to decreased MnSOD expression and insulin resistance in muscle cells of obese people. Cell Death Dis 2014; 5:e1136. [PMID: 24651439 PMCID: PMC3973244 DOI: 10.1038/cddis.2014.104] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Revised: 02/12/2014] [Accepted: 02/13/2014] [Indexed: 12/14/2022]
Abstract
Obesity is associated with chronic low-grade inflammation and oxidative stress that blunt insulin response in its target tissues, leading to insulin resistance (IR). IR is a characteristic feature of type 2 diabetes. Skeletal muscle is responsible for 75% of total insulin-dependent glucose uptake; consequently, skeletal muscle IR is considered to be the primary defect of systemic IR development. Interestingly, some obese people stay insulin-sensitive and metabolically healthy. With the aim of understanding this difference and identifying the mechanisms responsible for insulin sensitivity maintenance/IR development during obesity, we explored the role of the latent endoribonuclease (RNase L) in skeletal muscle cells. RNase L is a regulator of innate immunity, of double-stranded RNA sensors and of toll-like receptor (TLR) 4 signaling. It is regulated during inflammation by interferons and its activity is dependent on its binding to 2-5A, an oligoadenylate synthesized by oligoadenylate synthetases (OAS). Increased expression of RNase L or downregulation of its inhibitor (RLI) improved insulin response in mouse myogenic C2C12 cells and in primary human myotubes from normal-weight subjects treated with palmitate, a saturated free fatty acid (FFA) known to induce inflammation and oxidative stress via TLR4 activation. While RNase L and RLI levels remained unchanged, OAS level was decreased in primary myotubes from insulin-resistant obese subjects (OB-IR) compared with myotubes from insulin-sensitive obese subjects (OB-IS). TLR3 and mitochondrial manganese superoxide dismutase (MnSOD) were also underexpressed in OB-IR myotubes. Activation of RNase L by 2-5A transfection allowed to restore insulin response, OAS, MnSOD and TLR3 expression in OB-IR myotubes. Due to low expression of OAS, OB-IR myotubes present a defect in RNase L activation and TLR3 regulation. Consequently, MnSOD level is low and insulin sensitivity is reduced. These results support that RNase L activity limits FFA/obesity-induced impairment of insulin response in muscle cells via TLR3 and MnSOD expression.
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Latorre E, Mendoza C, Layunta E, Alcalde AI, Mesonero JE. TLR2, TLR3, and TLR4 activation specifically alters the oxidative status of intestinal epithelial cells. Cell Stress Chaperones 2014; 19:289-93. [PMID: 24068346 PMCID: PMC3933612 DOI: 10.1007/s12192-013-0461-8] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Revised: 09/03/2013] [Accepted: 09/04/2013] [Indexed: 01/08/2023] Open
Abstract
Intestinal inflammatory diseases are the result of multiple processes, including mucosal oxidative stress and perturbed homeostasis between commensal bacteria and mucosal immunity. Toll-like receptors (TLRs) recognize molecular-associated microorganisms' patterns and trigger innate immunity responses contributing to intestinal homeostasis and inflammatory responses. However, TLRs effects on redox balance in intestinal mucosa remain unknown. Therefore, the present study analyzes the effect of TLR2, TLR3, and TLR4 on both oxidative damage of lipids and proteins, and the activity of antioxidant enzymes in enterocyte-like Caco-2 cells. The results show that the activation of these TLRs increased lipid and protein oxidation levels; however, the effect on the antioxidant enzymes activity is different depending on the TLR activated. These results suggest that the activation of TLR2, TLR3, and TLR4 might affect intestinal inflammation by not only their inherent innate immunity responses, but also their pro-oxidative effects on intestinal epithelial cells.
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Affiliation(s)
- Eva Latorre
- />Department of Pharmacology and Physiology, Faculty of Veterinary Sciences, University of Zaragoza, Miguel Servet 177, 50013 Zaragoza, Spain
| | - Carmen Mendoza
- />Department of Pharmacology and Physiology, Faculty of Veterinary Sciences, University of Zaragoza, Miguel Servet 177, 50013 Zaragoza, Spain
- />Department of Basic Sciences. Faculty of Veterinary Sciences, University Centroccidental Lisandro Alvarado, Núcleo Hector Ochoa Zuleta, Tarabana, Estado Lara Venezuela
| | - Elena Layunta
- />Department of Pharmacology and Physiology, Faculty of Veterinary Sciences, University of Zaragoza, Miguel Servet 177, 50013 Zaragoza, Spain
| | - Ana I. Alcalde
- />Department of Pharmacology and Physiology, Faculty of Veterinary Sciences, University of Zaragoza, Miguel Servet 177, 50013 Zaragoza, Spain
| | - José E. Mesonero
- />Department of Pharmacology and Physiology, Faculty of Veterinary Sciences, University of Zaragoza, Miguel Servet 177, 50013 Zaragoza, Spain
- />Departamento de Farmacología y Fisiología, Facultad de Veterinaria, Miguel Servet 177, 50013 Zaragoza, Spain
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