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Zhu Y, Zhang M, Wang J, Wang Q. Lin28A Reduced Sevoflurane-Induced Nerve Injury and Cognitive Dysfunction by Inhibiting Tau Acetylation and Phosphorylation via Activating SIRT1 in Elderly Rats. Neurotox Res 2022; 40:1913-1923. [PMID: 36322362 DOI: 10.1007/s12640-022-00594-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 09/30/2022] [Accepted: 10/11/2022] [Indexed: 11/07/2022]
Abstract
Sevoflurane (Sev) might cause neurotoxicity in elderly rats. However, the role of Lin28A in Sev-induced neurotoxicity remains unclear in elderly rats. In this study, elderly rats were used to construct an Sev-induced nerve injury model. Learning and memory abilities were assessed by Morris water maze (MWM) trainings; pathological alterations in hippocampal region were assessed by HE staining; neuronal apoptosis was assessed by TUNEL; related protein expression was analyzed by immunofluorescence, immunohistochemistry, and Western blotting. Results of this study showed that Sev treatment caused nerve injury and cognitive dysfunction in elderly rats, with increased neuronal apoptosis and decreased Lin28A levels. Pathological impairment and learning and memory abilities of elderly rats were significantly improved after forced overexpression of Lin28A using AAV, accompanied by decreased expression of CD68, Iba-1, and GFAP. TUNEL analysis showed that Lin28A overexpression significantly reversed Sev-induced neuronal apoptosis. Further mechanistic analysis showed that Lin28A significantly promoted SIRT1 expression, which further reversed Sev-induced Tau acetylation at lysine 280 and 686 and Tau hyperphosphorylation, thereby alleviating nerve injury and cognitive dysfunction in elderly rats. The introduction of SIRT1 inhibitor EX527 further confirmed the involvement of SIRT1 in the regulation of Lin28A in elderly rats. In conclusion, our findings demonstrated that Lin28A reduced sevoflurane-induced nerve injury and cognitive dysfunction by inhibiting Tau acetylation and phosphorylation via activating SIRT1 in elderly rats.
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Affiliation(s)
- Yingjun Zhu
- Department of Anesthesiology, The Affiliated Huai'an No. 1 People's Hospital of Nanjing Medical University, No. 6 West Beijing Road, Huaiyin District , 223300, Huai'an, Jiangsu, China.
| | - Min Zhang
- Department of Anesthesiology, The Affiliated Huai'an No. 1 People's Hospital of Nanjing Medical University, No. 6 West Beijing Road, Huaiyin District , 223300, Huai'an, Jiangsu, China
| | - Jiayu Wang
- Department of Anesthesiology, The Affiliated Huai'an No. 1 People's Hospital of Nanjing Medical University, No. 6 West Beijing Road, Huaiyin District , 223300, Huai'an, Jiangsu, China
| | - Qingxiu Wang
- Department of Anesthesiology, The Affiliated Shanghai East Hospital of Tongji University, Shanghai, 200120, China
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Zhang YS, Gong JS, Yao ZY, Jiang JY, Su C, Li H, Kang CL, Liu L, Xu ZH, Shi JS. Insights into the source, mechanism and biotechnological applications of hyaluronidases. Biotechnol Adv 2022; 60:108018. [PMID: 35853550 DOI: 10.1016/j.biotechadv.2022.108018] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Revised: 07/11/2022] [Accepted: 07/13/2022] [Indexed: 01/10/2023]
Abstract
It has long been found that hyaluronidases exist in a variety of organisms, playing their roles in various biological processes including infection, envenomation and metabolic regulation through degrading hyaluronan. However, exploiting them as a bioresource for specific applications had not been extensively studied until the latest decades. In recent years, new application scenarios have been developed, which extended the field of application, and emphasized the research value of hyaluronidase. This critical review comprehensively summarizes existing studies on hyaluronidase from different source, particularly in their structures, action patterns, and biological functions in human and mammals. Furthermore, we give in-depth insight into the resource mining and protein engineering process of hyaluronidase, as well as strategies for their high-level production, indicating that mixed strategies should be adopted to obtain well-performing hyaluronidase with efficiency. In addition, advances in application of hyaluronidase were summarized and discussed. Finally, prospects for future researches are proposed, highlighting the importance of further investigation into the characteristics of hyaluronidases, and the necessity of investigating their products for the development of their application value.
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Affiliation(s)
- Yue-Sheng Zhang
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Life Sciences and Health Engineering, Jiangnan University, Wuxi 214122, PR China; National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, School of Biotechnology, Jiangnan University, Wuxi 214122, PR China
| | - Jin-Song Gong
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Life Sciences and Health Engineering, Jiangnan University, Wuxi 214122, PR China.
| | - Zhi-Yuan Yao
- National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, School of Biotechnology, Jiangnan University, Wuxi 214122, PR China; Jiangsu Provincial Engineering Research Center for Bioactive Product Processing, Jiangnan University, Wuxi 214122, PR China
| | - Jia-Yu Jiang
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Life Sciences and Health Engineering, Jiangnan University, Wuxi 214122, PR China
| | - Chang Su
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Life Sciences and Health Engineering, Jiangnan University, Wuxi 214122, PR China
| | - Heng Li
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Life Sciences and Health Engineering, Jiangnan University, Wuxi 214122, PR China
| | - Chuan-Li Kang
- Shandong Engineering Laboratory of Sodium Hyaluronate and its Derivatives, Shandong Focusfreda Biotech Co., Ltd, Qufu 273165, PR China
| | - Lei Liu
- Shandong Engineering Laboratory of Sodium Hyaluronate and its Derivatives, Shandong Focusfreda Biotech Co., Ltd, Qufu 273165, PR China
| | - Zheng-Hong Xu
- National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, School of Biotechnology, Jiangnan University, Wuxi 214122, PR China; Jiangsu Provincial Engineering Research Center for Bioactive Product Processing, Jiangnan University, Wuxi 214122, PR China
| | - Jin-Song Shi
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Life Sciences and Health Engineering, Jiangnan University, Wuxi 214122, PR China
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Kocurkova A, Nesporova K, Sandanusova M, Kerberova M, Lehka K, Velebny V, Kubala L, Ambrozova G. Endogenously-Produced Hyaluronan and Its Potential to Regulate the Development of Peritoneal Adhesions. Biomolecules 2021; 12:biom12010045. [PMID: 35053193 PMCID: PMC8773905 DOI: 10.3390/biom12010045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 12/17/2021] [Accepted: 12/24/2021] [Indexed: 12/23/2022] Open
Abstract
Formation of peritoneal adhesions (PA) is one of the major complications following intra-abdominal surgery. It is primarily caused by activation of the mesothelial layer and underlying tissues in the peritoneal membrane resulting in the transition of mesothelial cells (MCs) and fibroblasts to a pro-fibrotic phenotype. Pro-fibrotic transition of MCs—mesothelial-to-mesenchymal transition (MMT), and fibroblasts activation to myofibroblasts are interconnected to changes in cellular metabolism and culminate in the deposition of extracellular matrix (ECM) in the form of fibrotic tissue between injured sides in the abdominal cavity. However, ECM is not only a mechanical scaffold of the newly synthetized tissue but reciprocally affects fibrosis development. Hyaluronan (HA), an important component of ECM, is a non-sulfated glycosaminoglycan consisting of N-acetyl-D-glucosamine (GlcNAc) and D-glucuronic acid (GlcUA) that can affect the majority of processes involved in PA formation. This review considers the role of endogenously produced HA in the context of different fibrosis-related pathologies and its overlap in the development of PA.
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Affiliation(s)
- Anna Kocurkova
- Institute of Biophysics, Academy of Sciences of the Czech Republic, 612 65 Brno, Czech Republic; (A.K.); (M.S.); (M.K.); (L.K.)
- Institute of Experimental Biology, Faculty of Science, Masaryk University, 611 37 Brno, Czech Republic
- International Clinical Research Center, St. Anne’s University Hospital, 656 91 Brno, Czech Republic
| | - Kristina Nesporova
- Contipro a.s., Dolní Dobrouč 401, 561 02 Dolní Dobrouč, Czech Republic; (K.N.); (K.L.); (V.V.)
| | - Miriam Sandanusova
- Institute of Biophysics, Academy of Sciences of the Czech Republic, 612 65 Brno, Czech Republic; (A.K.); (M.S.); (M.K.); (L.K.)
- Institute of Experimental Biology, Faculty of Science, Masaryk University, 611 37 Brno, Czech Republic
- International Clinical Research Center, St. Anne’s University Hospital, 656 91 Brno, Czech Republic
| | - Michaela Kerberova
- Institute of Biophysics, Academy of Sciences of the Czech Republic, 612 65 Brno, Czech Republic; (A.K.); (M.S.); (M.K.); (L.K.)
| | - Katerina Lehka
- Contipro a.s., Dolní Dobrouč 401, 561 02 Dolní Dobrouč, Czech Republic; (K.N.); (K.L.); (V.V.)
| | - Vladimir Velebny
- Contipro a.s., Dolní Dobrouč 401, 561 02 Dolní Dobrouč, Czech Republic; (K.N.); (K.L.); (V.V.)
| | - Lukas Kubala
- Institute of Biophysics, Academy of Sciences of the Czech Republic, 612 65 Brno, Czech Republic; (A.K.); (M.S.); (M.K.); (L.K.)
- Institute of Experimental Biology, Faculty of Science, Masaryk University, 611 37 Brno, Czech Republic
- International Clinical Research Center, St. Anne’s University Hospital, 656 91 Brno, Czech Republic
| | - Gabriela Ambrozova
- Institute of Biophysics, Academy of Sciences of the Czech Republic, 612 65 Brno, Czech Republic; (A.K.); (M.S.); (M.K.); (L.K.)
- Correspondence:
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4
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Abstract
Neuropsychiatric sequalae to coronavirus disease 2019 (COVID-19) infection are beginning to emerge, like previous Spanish influenza and severe acute respiratory syndrome episodes. Streptococcal infection in paediatric patients causing obsessive compulsive disorder (PANDAS) is another recent example of an infection-based psychiatric disorder. Inflammation associated with neuropsychiatric disorders has been previously reported but there is no standard clinical management approach established. Part of the reason is that it is unclear what factors determine the specific neuronal vulnerability and the efficacy of anti-inflammatory treatment in neuroinflammation. The emerging COVID-19 data suggested that in the acute stage, widespread neuronal damage appears to be the result of abnormal and overactive immune responses and cytokine storm is associated with poor prognosis. It is still too early to know if there are long-term-specific neuronal or brain regional damages associated with COVID-19, resulting in distinct neuropsychiatric disorders. In several major psychiatric disorders where neuroinflammation is present, patients with abnormal inflammatory markers may also experience less than favourable response or treatment resistance when standard treatment is used alone. Evidence regarding the benefits of co-administered anti-inflammatory agents such as COX-2 inhibitor is encouraging in selected patients though may not benefit others. Disease-modifying therapies are increasingly being applied to neuropsychiatric diseases characterised by abnormal or hyperreactive immune responses. Adjunct anti-inflammatory treatment may benefit selected patients and is definitely an important component of clinical management in the presence of neuroinflammation.
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5
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Diverse Roles for Hyaluronan and Hyaluronan Receptors in the Developing and Adult Nervous System. Int J Mol Sci 2020; 21:ijms21175988. [PMID: 32825309 PMCID: PMC7504301 DOI: 10.3390/ijms21175988] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 08/17/2020] [Accepted: 08/18/2020] [Indexed: 02/07/2023] Open
Abstract
Hyaluronic acid (HA) plays a vital role in the extracellular matrix of neural tissues. Originally thought to hydrate tissues and provide mechanical support, it is now clear that HA is also a complex signaling molecule that can regulate cell processes in the developing and adult nervous systems. Signaling properties are determined by molecular weight, bound proteins, and signal transduction through specific receptors. HA signaling regulates processes such as proliferation, differentiation, migration, and process extension in a variety of cell types including neural stem cells, neurons, astrocytes, microglia, and oligodendrocyte progenitors. The synthesis and catabolism of HA and the expression of HA receptors are altered in disease and influence neuroinflammation and disease pathogenesis. This review discusses the roles of HA, its synthesis and breakdown, as well as receptor expression in neurodevelopment, nervous system function and disease.
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Reed MJ, Damodarasamy M, Banks WA. The extracellular matrix of the blood-brain barrier: structural and functional roles in health, aging, and Alzheimer's disease. Tissue Barriers 2019; 7:1651157. [PMID: 31505997 DOI: 10.1080/21688370.2019.1651157] [Citation(s) in RCA: 87] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
There is increasing interest in defining the location, content, and role of extracellular matrix (ECM) components in brain structure and function during development, aging, injury, and neurodegeneration. Studies in vivo confirm brain ECM has a dynamic composition with constitutive and induced alterations that impact subsequent cell-cell and cell-matrix interactions. Moreover, it is clear that for any given ECM component, the brain region, and cell type within that location, determines the direction, magnitude, and composition of those changes. This review will examine the ECM at the neurovascular unit (NVU) and the blood-brain barrier (BBB) within the NVU. The discussion will begin at the glycocalyx ECM on the luminal surface of the vasculature, and progress to the abluminal side with a focus on changes in basement membrane ECM during aging and neurodegeneration.
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Affiliation(s)
- May J Reed
- Department of Medicine, Division of Gerontology and Geriatric Medicine, University of Washington, Seattle, WA, USA
| | - Mamatha Damodarasamy
- Department of Medicine, Division of Gerontology and Geriatric Medicine, University of Washington, Seattle, WA, USA
| | - William A Banks
- Department of Medicine, Division of Gerontology and Geriatric Medicine, University of Washington, Seattle, WA, USA.,VA Puget Sound Health Care System, Geriatric Research Education and Clinical Center, Seattle, WA, USA
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7
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Su W, Matsumoto S, Banine F, Srivastava T, Dean J, Foster S, Pham P, Hammond B, Peters A, Girish KS, Rangappa KS, Basappa, Jose J, Hennebold JD, Murphy MJ, Bennett-Toomey J, Back SA, Sherman LS. A modified flavonoid accelerates oligodendrocyte maturation and functional remyelination. Glia 2019; 68:263-279. [PMID: 31490574 DOI: 10.1002/glia.23715] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 08/06/2019] [Accepted: 08/15/2019] [Indexed: 12/19/2022]
Abstract
Myelination delay and remyelination failure following insults to the central nervous system (CNS) impede axonal conduction and lead to motor, sensory and cognitive impairments. Both myelination and remyelination are often inhibited or delayed due to the failure of oligodendrocyte progenitor cells (OPCs) to mature into myelinating oligodendrocytes (OLs). Digestion products of the glycosaminoglycan hyaluronan (HA) have been implicated in blocking OPC maturation, but how these digestion products are generated is unclear. We tested the possibility that hyaluronidase activity is directly linked to the inhibition of OPC maturation by developing a novel modified flavonoid that functions as a hyaluronidase inhibitor. This compound, called S3, blocks some but not all hyaluronidases and only inhibits matrix metalloproteinase activity at high concentrations. We find that S3 reverses HA-mediated inhibition of OPC maturation in vitro, an effect that can be overcome by excess recombinant hyaluronidase. Furthermore, we find that hyaluronidase inhibition by S3 accelerates OPC maturation in an in vitro model of perinatal white matter injury. Finally, blocking hyaluronidase activity with S3 promotes functional remyelination in mice with lysolecithin-induced demyelinating corpus callosum lesions. All together, these findings support the notion that hyaluronidase activity originating from OPCs in CNS lesions is sufficient to prevent OPC maturation, which delays myelination or blocks remyelination. These data also indicate that modified flavonoids can act as selective inhibitors of hyaluronidase activity and can promote OPC maturation, making them excellent candidates to accelerate myelination or promote remyelination following perinatal and adult CNS insults.
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Affiliation(s)
- Weiping Su
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon
| | - Steven Matsumoto
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon.,Integrative Biosciences Department, School Dentistry, Oregon Health and Science University, Portland, Oregon
| | - Fatima Banine
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon
| | - Taasin Srivastava
- Department of Pediatrics, Oregon Health and Science University, Portland, Oregon
| | - Justin Dean
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Scott Foster
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon
| | - Peter Pham
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon
| | - Brian Hammond
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon
| | - Alec Peters
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon
| | - Kesturu S Girish
- Department of Studies and Research in Biochemistry, Tumkur University, Tumakuru, India
| | | | - Basappa
- Department of Studies in Organic Chemistry, University of Mysore, Manasagangotri, India
| | - Joachim Jose
- Institute of Pharmaceutical and Medicinal Chemistry, Phytochemistry, PharmaCampus, Westfälische Wilhelms-Universität Münster, Münster, Germany
| | - Jon D Hennebold
- Division of Reproductive and Developmental Sciences, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon
| | - Melinda J Murphy
- Division of Reproductive and Developmental Sciences, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon
| | - Jill Bennett-Toomey
- Division of Reproductive and Developmental Sciences, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon
| | - Stephen A Back
- Department of Pediatrics, Oregon Health and Science University, Portland, Oregon.,Department of Neurology, Oregon Health and Science University, Portland, Oregon
| | - Larry S Sherman
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health and Science University, Beaverton, Oregon.,Department of Cell, Developmental and Cancer Biology, Oregon Health and Science University, Portland, Oregon
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Ho MT, Teal CJ, Shoichet MS. A hyaluronan/methylcellulose-based hydrogel for local cell and biomolecule delivery to the central nervous system. Brain Res Bull 2019; 148:46-54. [PMID: 30898580 DOI: 10.1016/j.brainresbull.2019.03.005] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 03/01/2019] [Accepted: 03/12/2019] [Indexed: 02/03/2023]
Abstract
Regenerative medicine strategies rely on exogenous cell transplantation and/or endogenous cell stimulation. Biomaterials can help to increase the regenerative potential of cells and biomolecules by controlling transplanted cell fate and provide a local, sustained release of biomolecules. In this review, we describe the use of a hyaluronan/methylcellulose (HAMC)-based hydrogel as a delivery vehicle to the brain, spinal cord, and retina to promote cellular survival and tissue repair. We discuss various controlled release strategies to prolong the delivery of factors for neuroprotection. The versatility of this hydrogel for a diversity of applications highlights its potential to enhance cell- and biomolecule-based treatment strategies.
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Affiliation(s)
- Margaret T Ho
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Canada; Donnelly Centre for Cellular & Biomolecular Research, University of Toronto, Toronto, Canada
| | - Carter J Teal
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Canada; Donnelly Centre for Cellular & Biomolecular Research, University of Toronto, Toronto, Canada
| | - Molly S Shoichet
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Canada; Donnelly Centre for Cellular & Biomolecular Research, University of Toronto, Toronto, Canada; Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Canada; Department of Chemistry, University of Toronto, Toronto, Canada.
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9
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Hyaluronan biology: A complex balancing act of structure, function, location and context. Matrix Biol 2019; 78-79:1-10. [PMID: 30802498 DOI: 10.1016/j.matbio.2019.02.002] [Citation(s) in RCA: 189] [Impact Index Per Article: 37.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 02/09/2019] [Accepted: 02/11/2019] [Indexed: 02/07/2023]
Abstract
Cell-matrix interactions are fundamental to many developmental, homeostatic, immune and pathologic processes. Hyaluronan (HA), a critical component of the extracellular matrix (ECM) that regulates normal structural integrity and development, also regulates tissue responses during injury, repair, and regeneration. Though simple in its primary structure, HA regulates biological responses in a highly complex manner with balanced contributions from its molecular size and concentration, synthesis versus enzymatic and/or oxidative-nitrative fragmentation, interactions with key HA binding proteins and cell associated receptors, and its cell context-specific signaling. This review highlights the different, but inter-related factors that dictate the biological activity of HA and introduces the overarching themes that weave throughout this special issue of Matrix Biology on hyaluronan.
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10
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Li M, Liu J, Bi Y, Chen J, Zhao L. Potential Medications or Compounds Acting on Toll-like Receptors in Cerebral Ischemia. Curr Neuropharmacol 2018; 16:160-175. [PMID: 28571545 PMCID: PMC5883378 DOI: 10.2174/1570159x15666170601125139] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 05/24/2017] [Accepted: 05/31/2017] [Indexed: 01/22/2023] Open
Abstract
Background: Toll-like receptors play an integral role in the process of inflammatory response after ischemic in-jury. The therapeutic potential acting on TLRs is worth of evaluations. The aim of this review was to introduce readers some potential medications or compounds which could alleviate the ischemic damage via TLRs. Methods: Research articles online on TLRs were reviewed. Categorizations were listed according to the follows, methods acting on TLRs directly, modulations of MyD88 or TRIF signaling pathway, and the ischemic tolerance induced by the pre-conditioning or postconditioning with TLR ligands or minor cerebral ischemia via acting on TLRs. Results: There are only a few studies concerning on direct effects. Anti-TLR4 or anti-TLR2 therapies may serve as promis-ing strategies in acute events. Approaches targeting on inhibiting NF-κB signaling pathway and enhancing interferon regu-latory factor dependent signaling have attracted great interests. Not only drugs but compounds extracted from traditional Chinese medicine have been used to identify their neuroprotective effects against cerebral ischemia. In addition, many re-searchers have reported the positive therapeutic effects of preconditioning with agonists of TLR2, 3, 4, 7 and 9. Several trails have also explored the potential of postconditioning, which provide a new idea in ischemic treatments. Considering all the evidence above, many drugs and new compounds may have great potential to reduce ischemic insults. Conclusion: This review will focus on promising therapies which exerting neuroprotective effects against ischemic injury by acting on TLRs.
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Affiliation(s)
- Man Li
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Jing Liu
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.,Department of Neurology, Puai Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430033, China
| | - Ying Bi
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Jixiang Chen
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Lei Zhao
- Department of Infectious Diseases, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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11
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Abstract
The glycosaminoglycan hyaluronan (HA) is a key component of the microenvironment surrounding cells. In healthy tissues, HA molecules have extremely high molecular mass and consequently large hydrodynamic volumes. Tethered to the cell surface by clustered receptor proteins, HA molecules crowd each other, as well as other macromolecular species. This leads to severe nonideality in physical properties of the biomatrix, because steric exclusion leads to an increase in effective concentration of the macromolecules. The excluded volume depends on both polymer concentration and hydrodynamic volume/molecular mass. The biomechanical properties of the extracellular matrix, tissue hydration, receptor clustering, and receptor-ligand interactions are strongly affected by the presence of HA and by its molecular mass. In inflammation, reactive oxygen and nitrogen species fragment the HA chains. Depending on the rate of chain degradation relative to the rates of new synthesis and removal of damaged chains, short fragments of the HA molecules can be present at significant levels. Not only are the physical properties of the extracellular matrix affected, but the HA fragments decluster their primary receptors and act as endogenous danger signals. Bioanalytical methods to isolate and quantify HA fragments have been developed to determine profiles of HA content and size in healthy and diseased biological fluids and tissues. These methods have potential use in medical diagnostic tests. Therapeutic agents that modulate signaling by HA fragments show promise in wound healing and tissue repair without fibrosis.
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Affiliation(s)
- Mary K Cowman
- Tandon School of Engineering, New York University, New York, NY, United States
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