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Liu D, Zhang C, Zhang J, Xu GT, Zhang J. Molecular pathogenesis of subretinal fibrosis in neovascular AMD focusing on epithelial-mesenchymal transformation of retinal pigment epithelium. Neurobiol Dis 2023; 185:106250. [PMID: 37536385 DOI: 10.1016/j.nbd.2023.106250] [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: 04/15/2023] [Revised: 07/11/2023] [Accepted: 07/31/2023] [Indexed: 08/05/2023] Open
Abstract
Age-related macular degeneration (AMD) is a leading cause of vision loss among elderly people in developed countries. Neovascular AMD (nAMD) accounts for more than 90% of AMD-related vision loss. At present, intravitreal injection of anti-vascular endothelial growth factor (anti-VEGF) is widely used as the first-line therapy to decrease the choroidal and retinal neovascularizations, and thus to improve or maintain the visual acuity of the patients with nAMD. However, about 1/3 patients still progress to irreversible visual impairment due to subretinal fibrosis even with adequate anti-VEGF treatment. Extensive literatures support the critical role of epithelial-mesenchymal transformation (EMT) of retinal pigment epithelium (RPE) in the pathogenesis of subretinal fibrosis in nAMD, but the underlying mechanisms still remain largely unknown. This review summarized the molecular pathogenesis of subretinal fibrosis in nAMD, especially focusing on the transforming growth factor-β (TGF-β)-induced EMT pathways. It was also discussed how these pathways crosstalk and respond to signals from the microenvironment to mediate EMT and contribute to the progression of nAMD-related subretinal fibrosis. Targeting EMT signaling pathways might provide a promising and effective therapeutic strategy to treat subretinal fibrosis secondary to nAMD.
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Affiliation(s)
- Dandan Liu
- Department of Ophthalmology of Tongji Hospital and Laboratory of Clinical and Visual Sciences of Tongji Eye Institute, School of Medicine, Tongji University, Shanghai, China
| | - Chaoyang Zhang
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, Shanghai, China; National Clinical Research Center for Eye Diseases, Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China
| | - Jingting Zhang
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, Shanghai, China; National Clinical Research Center for Eye Diseases, Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China
| | - Guo-Tong Xu
- Department of Ophthalmology of Tongji Hospital and Laboratory of Clinical and Visual Sciences of Tongji Eye Institute, School of Medicine, Tongji University, Shanghai, China.
| | - Jingfa Zhang
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University, Shanghai, China; National Clinical Research Center for Eye Diseases, Shanghai Key Laboratory of Ocular Fundus Diseases, Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai Engineering Center for Precise Diagnosis and Treatment of Eye Diseases, Shanghai, China.
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Pan L, Cho KS, Wei X, Xu F, Lennikov A, Hu G, Tang J, Guo S, Chen J, Kriukov E, Kyle R, Elzaridi F, Jiang S, Dromel PA, Young M, Baranov P, Do CW, Williams RW, Chen J, Lu L, Chen DF. IGFBPL1 is a master driver of microglia homeostasis and resolution of neuroinflammation in glaucoma and brain tauopathy. Cell Rep 2023; 42:112889. [PMID: 37527036 PMCID: PMC10528709 DOI: 10.1016/j.celrep.2023.112889] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 03/08/2023] [Accepted: 07/12/2023] [Indexed: 08/03/2023] Open
Abstract
Microglia shift toward an inflammatory phenotype during aging that is thought to exacerbate age-related neurodegeneration. The molecular and cellular signals that resolve neuroinflammation post-injury are largely undefined. Here, we exploit systems genetics methods based on the extended BXD murine reference family and identify IGFBPL1 as an upstream cis-regulator of microglia-specific genes to switch off inflammation. IGFBPL1 is expressed by mouse and human microglia, and higher levels of its expression resolve lipopolysaccharide-induced neuroinflammation by resetting the transcriptome signature back to a homeostatic state via IGF1R signaling. Conversely, IGFBPL1 deficiency or selective deletion of IGF1R in microglia shifts these cells to an inflammatory landscape and induces early manifestation of brain tauopathy and retinal neurodegeneration. Therapeutic administration of IGFBPL1 drives pro-homeostatic microglia and prevents glaucomatous neurodegeneration and vision loss in mice. These results identify IGFBPL1 as a master driver of the counter-inflammatory microglial modulator that presents an endogenous resolution of neuroinflammation to prevent neurodegeneration in eye and brain.
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Affiliation(s)
- Li Pan
- Schepens Eye Research Institute of Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA; School of Optometry, The Hong Kong Polytechnic University, Hong Kong 999077, China
| | - Kin-Sang Cho
- Schepens Eye Research Institute of Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA
| | - Xin Wei
- Schepens Eye Research Institute of Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA; Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China
| | - Fuyi Xu
- Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN 38163, USA; Shandong Technology Innovation Center of Molecular Targeting and Intelligent Diagnosis and Treatment, School of Pharmacy, Binzhou Medical University, Yantai, Shandong 264003, China
| | - Anton Lennikov
- Schepens Eye Research Institute of Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA
| | - Guangan Hu
- Koch Institute for Integrative Cancer Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Jing Tang
- Schepens Eye Research Institute of Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA; Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, Sichuan 610041, China
| | - Shuai Guo
- Schepens Eye Research Institute of Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA
| | - Julie Chen
- Schepens Eye Research Institute of Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA
| | - Emil Kriukov
- Schepens Eye Research Institute of Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA
| | - Robert Kyle
- Schepens Eye Research Institute of Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA
| | - Farris Elzaridi
- Schepens Eye Research Institute of Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA
| | - Shuhong Jiang
- Schepens Eye Research Institute of Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA
| | - Pierre A Dromel
- Schepens Eye Research Institute of Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA
| | - Michael Young
- Schepens Eye Research Institute of Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA
| | - Petr Baranov
- Schepens Eye Research Institute of Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA
| | - Chi-Wai Do
- School of Optometry, The Hong Kong Polytechnic University, Hong Kong 999077, China
| | - Robert W Williams
- Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN 38163, USA
| | - Jianzhu Chen
- Koch Institute for Integrative Cancer Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Lu Lu
- Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN 38163, USA.
| | - Dong Feng Chen
- Schepens Eye Research Institute of Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School, Boston, MA 02114, USA.
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Balne PK, Gupta S, Landon KM, Sinha NR, Hofmann AC, Hauser N, Sinha PR, Huang H, Kempuraj D, Mohan RR. Characterization of C-X-C chemokine receptor type 5 in the cornea and role in the inflammatory response after corneal injury. Exp Eye Res 2023; 226:109312. [PMID: 36400287 DOI: 10.1016/j.exer.2022.109312] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 10/13/2022] [Accepted: 11/06/2022] [Indexed: 11/17/2022]
Abstract
C-X-C chemokine receptor type 5 (CXCR5) regulates inflammatory responses in ocular and non-ocular tissues. However, its expression and role in the cornea are still unknown. Here, we report the expression of CXCR5 in human cornea in vitro and mouse corneas in vivo, and its functional role in corneal inflammation using C57BL/6J wild-type (CXCR5+/+) and CXCR5-deficient (CXCR5-/-) mice, topical alkali injury, clinical eye imaging, histology, immunofluorescence, PCR, qRT-PCR, and western blotting. Human corneal epithelial cells, stromal fibroblasts, and endothelial cells demonstrated CXCR5 mRNA and protein expression in PCR, and Western blot analyses, respectively. To study the functional role of CXCR5 in vivo, mice were divided into four groups: Group-1 (CXCR5+/+ alkali injured cornea; n = 30), Group-2 (CXCR5-/- alkali injured cornea; n = 30), Group-3 (CXCR5+/+ naïve cornea; n = 30), and Group-4 (CXCR5-/- naïve cornea; n = 30). Only one eye was wounded with alkali. Clinical corneal evaluation and imaging were performed before and after injury. Mice were euthanized 4 h, 3 days, or 7 days after injury, eyes were excised and used for histology, immunofluorescence, and qRT-PCR. In clinical eye examinations, CXCR5-/- mouse corneas showed ocular health akin to the naïve corneas. Alkali injured CXCR5+/+ mouse corneas showed significantly increased mRNA (p < 0.001) and protein (p < 0.01 or p < 0.0001) levels of the CXCR5 compared to the naïve corneas. Likewise, alkali injured CXCR5-/- mouse corneas showed remarkably amplified inflammation in clinical eye exams in live animals. The histological and molecular analyses of these corneas post euthanasia exhibited markedly augmented inflammatory cells in H&E staining and significant CD11b + cells in immunofluorescence (p < 0.01 or < 0.05); and tumor necrosis factor-alpha (TNFα; p < 0.05), cyclooxygenase 2 (COX-2; p < 0.0001), interleukin (IL)-1β (p < 0.0001), and IL-6 (p < 0.0001 or < 0.01) mRNA expression compared to the CXCR5+/+ mouse corneas. Interestingly, CXCR5-/- alkali injured corneas also showed altered mRNA expression of fibrotic alpha smooth muscle actin (α-SMA; p > 0.05) and angiogenic vascular endothelial growth factor (VEGF; p < 0.01) compared to the CXCR5+/+ alkali injured corneas. In summary, the CXCR5 gene is expressed in all three major layers of the cornea and appears to influence corneal inflammatory and repair events post-injury in vivo. More studies are warranted to tease the mechanistic role of CXCR5 in corneal inflammation and wound healing.
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Affiliation(s)
- Praveen K Balne
- Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, United States; One-Health Vision Research Program, Departments of Veterinary Medicine & Surgery and Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, United States
| | - Suneel Gupta
- Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, United States; One-Health Vision Research Program, Departments of Veterinary Medicine & Surgery and Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, United States
| | - Keele M Landon
- Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, United States; One-Health Vision Research Program, Departments of Veterinary Medicine & Surgery and Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, United States
| | - Nishant R Sinha
- Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, United States; One-Health Vision Research Program, Departments of Veterinary Medicine & Surgery and Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, United States
| | | | - Nicholas Hauser
- One-Health Vision Research Program, Departments of Veterinary Medicine & Surgery and Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, United States
| | - Prashant R Sinha
- Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, United States; One-Health Vision Research Program, Departments of Veterinary Medicine & Surgery and Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, United States
| | - Hu Huang
- Mason Eye Institute, School of Medicine, University of Missouri, Columbia, MO, United States
| | - Duraisamy Kempuraj
- Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, United States; One-Health Vision Research Program, Departments of Veterinary Medicine & Surgery and Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, United States
| | - Rajiv R Mohan
- Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, United States; One-Health Vision Research Program, Departments of Veterinary Medicine & Surgery and Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, United States; Mason Eye Institute, School of Medicine, University of Missouri, Columbia, MO, United States.
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Saddala MS, Lennikov A, Mukwaya A, Yang X, Tang S, Huang H. Data mining and network analysis reveals C-X-C chemokine receptor type 5 is involved in the pathophysiology of age-related macular degeneration. J Biomol Struct Dyn 2022; 40:10783-10792. [PMID: 34243690 DOI: 10.1080/07391102.2021.1949391] [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] [Indexed: 10/20/2022]
Abstract
Our previous studies found that the C-X-C motif chemokine receptor 5 (CXCR5) loss leads to retinal pigment epithelium (RPE) dysfunction and AMD pathogenesis. The current study aimed to characterize the G protein-coupled receptor (GPCR) structure of CXCR5 and analyze its interactions with AMD-related risk genes. The sequence alignments, homology model of CXCR5 and structural assessment analysis were performed. Data and text mining were then performed to identify AMD-related risk genes and their interaction with CXCR5 using statistical and mathematical algorithms. Sequence alignment and phylogenetic tree analysis revealed that human CXCR5 was highly similar (85.4839%) to the rabbit. The least similarity (33.871%) was found to be in zebrafish compared to the other species. The CXCR5 model structural assessment and secondary structure analysis exhibited an excellent model. Network analysis revealed that IL10, TNF, ICAM1, CXCL1, CXCL8, APP, TLR4, SELL, C3, IL17A and CCR2 were the most connected genes CXCR5. These findings suggest that CXCR5 signaling may regulate the biological function of RPE and modulate AMD pathophysiology via GPCR signaling and interacting with identified AMD risk genes. In summary, the data presented here provide novel and crucial insights into the molecular mechanisms of CXCR5 involvement in AMD.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Madhu Sudhana Saddala
- Department of Ophthalmology, University of Missouri-Columbia, MO, USA.,Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Anton Lennikov
- Department of Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear, Harvard Medical School, Boston, MA, USA
| | - Anthony Mukwaya
- Department of Ophthalmology, Institute for Clinical, and Experimental Medicine, Faculty of Health Sciences, Linköping University, Linköping, Sweden
| | - Xu Yang
- Aier Eye Institute, Aier Eye Hospital Group, Changsha, Hunan, China
| | - Shibo Tang
- Aier Eye Institute, Aier Eye Hospital Group, Changsha, Hunan, China
| | - Hu Huang
- Department of Ophthalmology, University of Missouri-Columbia, MO, USA
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Yang X, Diaz V, Huang H. The Role of Interferon Regulatory Factor 1 in Regulating Microglial Activation and Retinal Inflammation. Int J Mol Sci 2022; 23:ijms232314664. [PMID: 36498991 PMCID: PMC9739975 DOI: 10.3390/ijms232314664] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 11/20/2022] [Accepted: 11/21/2022] [Indexed: 11/25/2022] Open
Abstract
Microglia are resident immune cells in the central nervous system (CNS). Microglial activation plays a prominent role in neuroinflammation and CNS diseases. However, the underlying mechanisms of microglial activation are not well understood. Here, we report that the transcription factor interferon regulatory factor 1 (IRF1) plays critical roles in microglial activation and retinal inflammation by regulating pro- and anti-inflammatory gene expression. IRF1 expression was upregulated in activated retinal microglia compared to those at the steady state. IRF1 knockout (KO) in BV2 microglia cells (BV2ΔIRF1) created by CRISPR/Cas9 genome-editing technique causes decreased microglia proliferation, migration, and phagocytosis. IRF1-KO decreased pro-inflammatory M1 marker gene expression induced by lipopolysaccharides (LPS), such as IL-6, COX-2, and CCL5, but increased anti-inflammatory M2 marker gene expression by IL-4/13, such as Arg-1, CD206, and TGF-β. Compared to the wild-type cells, microglial-conditioned media (MCM) of activated BV2ΔIRF1 cell cultures reduced toxicity or death to several retinal cells, including mouse cone photoreceptor-like 661 W cells, rat retinal neuron precursor R28 cells, and human ARPE-19 cells. IRF1 knockdown by siRNA alleviated microglial activation and retinal inflammation induced by LPS in mice. Together, the findings suggest that IRF1 plays a vital role in regulating microglial activation and retinal inflammation and, therefore, may be targeted for treating inflammatory and degenerative retinal diseases.
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Affiliation(s)
- Xu Yang
- Department of Ophthalmology, School of Medicine, University of Missouri, Columbia, MO 65212, USA
- Aier Eye Hospital Group, Aier Eye Institute, Changsha 410015, China
| | - Valeria Diaz
- Department of Ophthalmology, School of Medicine, University of Missouri, Columbia, MO 65212, USA
| | - Hu Huang
- Department of Ophthalmology, School of Medicine, University of Missouri, Columbia, MO 65212, USA
- Correspondence: ; Tel.: +1(573)-882-9899
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Landowski M, Bowes Rickman C. Targeting Lipid Metabolism for the Treatment of Age-Related Macular Degeneration: Insights from Preclinical Mouse Models. J Ocul Pharmacol Ther 2021; 38:3-32. [PMID: 34788573 PMCID: PMC8817708 DOI: 10.1089/jop.2021.0067] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Age-related macular degeneration (AMD) is a major leading cause of irreversible visual impairment in the world with limited therapeutic interventions. Histological, biochemical, genetic, and epidemiological studies strongly implicate dysregulated lipid metabolism in the retinal pigmented epithelium (RPE) in AMD pathobiology. However, effective therapies targeting lipid metabolism still need to be identified and developed for this blinding disease. To test lipid metabolism-targeting therapies, preclinical AMD mouse models are needed to establish therapeutic efficacy and the role of lipid metabolism in the development of AMD-like pathology. In this review, we provide a comprehensive overview of current AMD mouse models available to researchers that could be used to provide preclinical evidence supporting therapies targeting lipid metabolism for AMD. Based on previous studies of AMD mouse models, we discuss strategies to modulate lipid metabolism as well as examples of studies evaluating lipid-targeting therapeutics to restore lipid processing in the RPE. The use of AMD mouse models may lead to worthy lipid-targeting candidate therapies for clinical trials to prevent the blindness caused by AMD.
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Affiliation(s)
- Michael Landowski
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, Wisconsin, USA.,McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, Wisconsin, USA.,Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Catherine Bowes Rickman
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina, USA.,Department of Cell Biology, Duke University Medical Center, Durham, North Carolina, USA
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Shen Y, Zhang Y, Du J, Jiang B, Shan T, Li H, Bao H, Si Y. CXCR5 down-regulation alleviates cognitive dysfunction in a mouse model of sepsis-associated encephalopathy: potential role of microglial autophagy and the p38MAPK/NF-κB/STAT3 signaling pathway. J Neuroinflammation 2021; 18:246. [PMID: 34711216 PMCID: PMC8554863 DOI: 10.1186/s12974-021-02300-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Accepted: 10/18/2021] [Indexed: 12/23/2022] Open
Abstract
Background Cognitive deficits are common in patients with sepsis. Previous studies in sepsis-associated encephalopathy (SAE) implicated the C-X-C chemokine receptor type (CXCR) 5. The present study used a mouse model of SAE to examine whether CXCR5 down-regulation could attenuate cognitive deficits. Methods Sepsis was induced in adult male C57BL/6 J and CXCR5−/− mice by cecal ligation and puncture (CLP). At 14–18 days after surgery, animals were tested in a Morris water maze, followed by a fear conditioning test. Transmission electron microscopy of hippocampal sections was used to assess levels of autophagy. Primary microglial cultures challenged with lipopolysaccharide (LPS) were used to examine the effects of short interfering RNA targeting CXCR5, and to investigate the possible involvement of the p38MAPK/NF-κB/STAT3 signaling pathway. Results CLP impaired learning and memory and up-regulated CXCR5 in hippocampal microglia. CLP activated hippocampal autophagy, as reflected by increases in numbers of autophagic vacuoles, conversion of microtubule-associated protein 1 light chain 3 (LC3) from form I to form II, accumulation of beclin-1 and autophagy-related gene-5, and a decrease in p62 expression. CLP also shifted microglial polarization to the M1 phenotype, and increased levels of IL-1β, IL-6 and phosphorylated p38MAPK. CXCR5 knockout further enhanced autophagy but partially reversed all the other CLP-induced effects, including cognitive deficits. Similar effects on autophagy and cytokine expression were observed after knocking down CXCR5 in LPS-challenged primary microglial cultures; this knockdown also partially reversed LPS-induced up-regulation of phosphorylated NF-κB and STAT3. The p38MAPK agonist P79350 partially reversed the effects of CXCR5 knockdown in microglial cultures. Conclusions CXCR5 may act via p38MAPK/NF-κB/STAT3 signaling to inhibit hippocampal autophagy during sepsis and thereby contribute to cognitive dysfunction. Down-regulating CXCR5 can restore autophagy and mitigate the proinflammatory microenvironment in the hippocampus.
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Affiliation(s)
- Yanan Shen
- Department of Anesthesiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, 210006, Jiangsu, China
| | - Yuan Zhang
- Department of Anesthesiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, 210006, Jiangsu, China
| | - Jiayue Du
- Department of Anesthesiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, 210006, Jiangsu, China
| | - Baochun Jiang
- Institute of Pain Medicine and Special Environmental Medicine, Nantong University, Nantong, 226019, Jiangsu, China
| | - Tao Shan
- Department of Anesthesiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, 210006, Jiangsu, China
| | - Haojia Li
- Department of Anesthesiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, 210006, Jiangsu, China
| | - Hongguang Bao
- Department of Anesthesiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, 210006, Jiangsu, China
| | - Yanna Si
- Department of Anesthesiology, Nanjing First Hospital, Nanjing Medical University, Nanjing, 210006, Jiangsu, China.
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