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Ozsan McMillan I, Li JP, Wang L. Heparan sulfate proteoglycan in Alzheimer's disease: aberrant expression and functions in molecular pathways related to amyloid-β metabolism. Am J Physiol Cell Physiol 2023; 324:C893-C909. [PMID: 36878848 PMCID: PMC10069967 DOI: 10.1152/ajpcell.00247.2022] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 02/28/2023] [Accepted: 02/28/2023] [Indexed: 03/08/2023]
Abstract
Alzheimer's disease (AD) is the most common form of dementia. Currently, there is no effective treatment for AD, as its etiology remains poorly understood. Mounting evidence suggests that the accumulation and aggregation of amyloid-β peptides (Aβ), which constitute amyloid plaques in the brain, is critical for initiating and accelerating AD pathogenesis. Considerable efforts have been dedicated to shedding light on the molecular basis and fundamental origins of the impaired Aβ metabolism in AD. Heparan sulfate (HS), a linear polysaccharide of the glycosaminoglycan family, co-deposits with Aβ in plaques in the AD brain, directly binds and accelerates Aβ aggregation, and mediates Aβ internalization and cytotoxicity. Mouse model studies demonstrate that HS regulates Aβ clearance and neuroinflammation in vivo. Previous reviews have extensively explored these discoveries. Here, this review focuses on the recent advancements in understanding abnormal HS expression in the AD brain, the structural aspects of HS-Aβ interaction, and the molecules involved in modulating Aβ metabolism through HS interaction. Furthermore, this review presents a perspective on the potential effects of abnormal HS expression on Aβ metabolism and AD pathogenesis. In addition, the review highlights the importance of conducting further research to differentiate the spatiotemporal components of HS structure and function in the brain and AD pathogenesis.
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Affiliation(s)
- Ilayda Ozsan McMillan
- Department of Molecular Pharmacology & Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida, United States
- Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, Florida, United States
| | - Jin-Ping Li
- Department of Medical Biochemistry and Microbiology & The Biomedical Center, University of Uppsala, Uppsala, Sweden
- SciLifeLab Uppsala, University of Uppsala, Uppsala, Sweden
| | - Lianchun Wang
- Department of Molecular Pharmacology & Physiology, Morsani College of Medicine, University of South Florida, Tampa, Florida, United States
- Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, Florida, United States
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Snow AD, Cummings JA, Lake T. The Unifying Hypothesis of Alzheimer's Disease: Heparan Sulfate Proteoglycans/Glycosaminoglycans Are Key as First Hypothesized Over 30 Years Ago. Front Aging Neurosci 2021; 13:710683. [PMID: 34671250 PMCID: PMC8521200 DOI: 10.3389/fnagi.2021.710683] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 08/23/2021] [Indexed: 01/03/2023] Open
Abstract
The updated "Unifying Hypothesis of Alzheimer's disease" (AD) is described that links all the observed neuropathology in AD brain (i.e., plaques, tangles, and cerebrovascular amyloid deposits), as well as inflammation, genetic factors (involving ApoE), "AD-in-a-Dish" studies, beta-amyloid protein (Aβ) as a microbial peptide; and theories that bacteria, gut microflora, gingivitis and viruses all play a role in the cause of AD. The common link is the early accumulation of heparan sulfate proteoglycans (HSPGs) and heparan sulfate glycosaminoglycans (GAGs). HS GAG accumulation and/or decreased HS GAG degradation is postulated to be the key initiating event. HS GAGs and highly sulfated macromolecules induce Aβ 1-40 (but not 1-42) to form spherical congophilic maltese-cross star-like amyloid core deposits identical to those in the AD brain. Heparin/HS also induces tau protein to form paired helical filaments (PHFs). Increased sulfation and/or decreased degradation of HSPGs and HS GAGs that occur due to brain aging leads to the formation of plaques and tangles in AD brain. Knockout of HS genes markedly reduce the accumulation of Aβ fibrils in the brain demonstrating that HS GAGs are key. Bacteria and viruses all use cell surface HS GAGs for entry into cells, including SARS-CoV-2. Bacteria and viruses cause HS GAGs to rapidly increase to cause near-immediate aggregation of Aβ fibrils. "AD-in-a-dish" studies use "Matrigel" as the underlying scaffold that spontaneously causes plaque, and then tangle formation in a dish. Matrigel mostly contains large amounts of perlecan, the same specific HSPG implicated in AD and amyloid disorders. Mucopolysaccharidoses caused by lack of specific HS GAG enzymes lead to massive accumulation of HS in lysosomal compartments in neurons and contribute to cognitive impairment in children. Neurons full of HS demonstrate marked accumulation and fibrillization of Aβ, tau, α-synuclein, and prion protein (PrP) in mucopolysaccharidosis animal models demonstrating that HS GAG accumulation is a precursor to Aβ accumulation in neurons. Brain aging leads to changes in HSPGs, including newly identified splice variants leading to increased HS GAG sulfation in the AD brain. All of these events lead to the new "Unifying Hypothesis of Alzheimer's disease" that further implicates HSPGs /HS GAGs as key (as first hypothesized by Snow and Wight in 1989).
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Farach-Carson MC, Warren CR, Harrington DA, Carson DD. Border patrol: insights into the unique role of perlecan/heparan sulfate proteoglycan 2 at cell and tissue borders. Matrix Biol 2013; 34:64-79. [PMID: 24001398 DOI: 10.1016/j.matbio.2013.08.004] [Citation(s) in RCA: 93] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Revised: 08/16/2013] [Accepted: 08/17/2013] [Indexed: 12/11/2022]
Abstract
The extracellular matrix proteoglycan (ECM) perlecan, also known as heparan sulfate proteoglycan 2 or HSPG2, is one of the largest (>200 nm) and oldest (>550 M years) extracellular matrix molecules. In vertebrates, perlecan's five-domain structure contains numerous independently folding modules with sequence similarities to other ECM proteins, all connected like cars into one long, diverse complex train following a unique N-terminal domain I decorated with three long glycosaminoglycan chains, and an additional glycosaminoglycan attachment site in the C-terminal domain V. In lower invertebrates, perlecan is not typically a proteoglycan, possessing the majority of the core protein modules, but lacking domain I where the attachment sites for glycosaminoglycan chains are located. This suggests that uniting the heparan sulfate binding growth factor functions of domain I and the core protein functions of the rest of the molecule in domains II-V occurred later in evolution for a new functional purpose. In this review, we surveyed several decades of pertinent literature to ask a fundamental question: Why did nature design this protein uniquely as an extraordinarily long multifunctional proteoglycan with a single promoter regulating expression, rather than separating these functions into individual proteins that could be independently regulated? We arrived at the conclusion that the concentration of perlecan at functional borders separating tissues and tissue layers is an ancient key function of the core protein. The addition of the heparan sulfate chains in domain I likely occurred as an additional means of binding the core protein to other ECM proteins in territorial matrices and basement membranes, and as a means to reserve growth factors in an on-site depot to assist with rapid repair of those borders when compromised, such as would occur during wounding. We propose a function for perlecan that extends its role from that of an extracellular scaffold, as we previously suggested, to that of a critical agent for establishing and patrolling tissue borders in complex tissues in metazoans. We also propose that understanding these unique functions of the individual portions of the perlecan molecule can provide new insights and tools for engineering of complex multi-layered tissues including providing the necessary cues for establishing neotissue borders.
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Affiliation(s)
- Mary C Farach-Carson
- Department of Biochemistry and Cell Biology, Rice University W100 George R. Brown Hall P.O. Box 1892, MS-140, Houston, TX 77251-1892, United States.
| | - Curtis R Warren
- Department of Biochemistry and Cell Biology, Rice University W100 George R. Brown Hall P.O. Box 1892, MS-140, Houston, TX 77251-1892, United States
| | - Daniel A Harrington
- Department of Biochemistry and Cell Biology, Rice University W100 George R. Brown Hall P.O. Box 1892, MS-140, Houston, TX 77251-1892, United States
| | - Daniel D Carson
- Department of Biochemistry and Cell Biology, Rice University W100 George R. Brown Hall P.O. Box 1892, MS-140, Houston, TX 77251-1892, United States
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Leadbeater WE, Gonzalez AM, Logaras N, Berry M, Turnbull JE, Logan A. Intracellular trafficking in neurones and glia of fibroblast growth factor-2, fibroblast growth factor receptor 1 and heparan sulphate proteoglycans in the injured adult rat cerebral cortex. J Neurochem 2006; 96:1189-200. [PMID: 16417571 DOI: 10.1111/j.1471-4159.2005.03632.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The potent gliogenic and neurotrophic fibroblast growth factor (FGF)-2 signals through a receptor complex comprising high-affinity FGF receptor (FGFR)1 with heparan sulphate proteoglycans (HSPGs) as co-receptors. We examined the intracellular dynamics of FGF-2, FGFR1 and the HSPGs syndecan-2 and -3, glypican-1 and -2, and perlecan in neurones and glia in and around adult rat cerebral wounds. In the intact cerebral cortex, FGF-2 and FGFR1 mRNA and protein were constitutively expressed in astrocytes and neurones respectively. FGF-2 protein was localized exclusively to astrocyte nuclei. After injury, expression of FGF-2 mRNA was up-regulated only in astrocytes, whereas FGFR1 mRNA expression was increased in both glia and neurones, a disparity indicating that FGF-2 may act as a paracrine and autocrine factor for neurones and glia respectively. FGF-2 protein localized to both cytoplasm and nuclei of injury-responsive neurones and glia. There was weak or no staining of HSPGs in the normal cerebral neuropil and glia nuclei, with a few immunopositive neurones. Specific HSPGs responded to injury by differentially co-localizing with trafficked intracellular FGF-2 and FGFR1. The spatiotemporal dynamics of FGF-2-FGFR1-HSPG complex formation implies a role for individual HSPGs in regulating FGF-2 storage, nuclear trafficking and cell-specific injury responses in CNS wounds.
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Affiliation(s)
- W E Leadbeater
- Molecular Neuroscience Group, Division of Medical Sciences, University of Birmingham, Birmingham, UK.
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Bussini S, Meda L, Scarpini E, Clementi E, Conti G, Tiriticco M, Bresolin N, Baron P. Heparan sulfate proteoglycan induces the production of NO and TNF-alpha by murine microglia. IMMUNITY & AGEING 2005; 2:11. [PMID: 16022734 PMCID: PMC1208935 DOI: 10.1186/1742-4933-2-11] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2005] [Accepted: 07/16/2005] [Indexed: 11/10/2022]
Abstract
Background A common feature of Alzheimer's disease (AD) pathology is the abundance of activated microglia in neuritic plaques containing amyloid-beta protein (Aβ) and associated molecules including heparan sulfate proteoglycan (HSPG). Besides the role as pathological chaperone favouring amyloidogenesis, little is known about whether or not HSPG can induce microglial activation. Cultures of primary murine microglia were used to assess the effect of HSPG on production of proinflammatory molecules that are known to be present in neuritic plaques of AD. Results HSPG stimulated up-regulation of tumor necrosis factor-alpha (TNF-α), production of inducible nitric oxide synthase (iNOS) mRNA and accumulation of TNF-α protein and nitrite (NO2-) in a time- and concentration-dependent manner. The effects of HSPG were primarily due to the property of the protein core as indicated by the lack of microglial accumulation of TNF-α and NO2- in response to denaturated HSPG or heparan sulfate GAG chains (HS). Conclusion These data demonstrate that HSPG may contribute to chronic microglial activation and neurodegeneration seen in neuritic plaques of AD.
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Affiliation(s)
- Simona Bussini
- Department of Neurological Sciences, Centre for Excellence on Neurodegenerative Diseases and "Dino Ferrari" Center, University of Milan, Fondazione IRCCS "Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena", Via F. Sforza 35, 20122 Milan, Italy
| | - Lucia Meda
- Department of Neurological Sciences, Centre for Excellence on Neurodegenerative Diseases and "Dino Ferrari" Center, University of Milan, Fondazione IRCCS "Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena", Via F. Sforza 35, 20122 Milan, Italy
| | - Elio Scarpini
- Department of Neurological Sciences, Centre for Excellence on Neurodegenerative Diseases and "Dino Ferrari" Center, University of Milan, Fondazione IRCCS "Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena", Via F. Sforza 35, 20122 Milan, Italy
| | - Emilio Clementi
- Dept. Preclinical Sciences, University of Milano, 20157 - Milano and E.Medea Scientific Institute 23842 - Bosisio Pasini, Italy
| | - Giancarlo Conti
- Department of Neurological Sciences, Centre for Excellence on Neurodegenerative Diseases and "Dino Ferrari" Center, University of Milan, Fondazione IRCCS "Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena", Via F. Sforza 35, 20122 Milan, Italy
| | - Marco Tiriticco
- Department of Neurological Sciences, Centre for Excellence on Neurodegenerative Diseases and "Dino Ferrari" Center, University of Milan, Fondazione IRCCS "Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena", Via F. Sforza 35, 20122 Milan, Italy
| | - Nereo Bresolin
- Department of Neurological Sciences, Centre for Excellence on Neurodegenerative Diseases and "Dino Ferrari" Center, University of Milan, Fondazione IRCCS "Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena", Via F. Sforza 35, 20122 Milan, Italy
| | - Pierluigi Baron
- Department of Neurological Sciences, Centre for Excellence on Neurodegenerative Diseases and "Dino Ferrari" Center, University of Milan, Fondazione IRCCS "Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena", Via F. Sforza 35, 20122 Milan, Italy
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Stéphan A, Phillips AG. A case for a non-transgenic animal model of Alzheimer's disease. GENES BRAIN AND BEHAVIOR 2005; 4:157-72. [PMID: 15810904 DOI: 10.1111/j.1601-183x.2004.00113.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Alzheimer's disease (AD) is associated with an early impairment in memory and is the major cause of dementia in the elderly. beta-Amyloid (Abeta) is believed to be a primary factor in the pathogenic pathway leading to dementia. Mounting evidence suggests that this syndrome begins with subtle alterations in synaptic efficacy prior to extensive neuronal degeneration and that the synaptic dysfunction could be caused by diffusible oligomeric assemblies of Abeta. This paper reviews the findings from behavioral analysis, electrophysiology, neuropathology and nootropic drug screening studies involving exogenous administration of Abeta in normal rodent brains. This non-transgenic model of amyloid pathology in vivo is presented as a complementary alternative model to transgenic mice to study the cellular and molecular pathways induced by amyloid, which in turn may be a causal factor in the disruption of cognition. The data reviewed here confirm that the diffusible form of Abeta rapidly induces synaptic dysfunction and a secondary process involving cellular cascades induced by the fibrillar form of amyloid. The time-course of alteration in memory processes implicates at least two different mechanisms that may be targeted with selective therapies aimed at improving memory in some AD patients.
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Affiliation(s)
- A Stéphan
- Department of Psychiatry and the Brain Research Centre, University of British Columbia, Vancouver, Canada.
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Blasko I, Stampfer-Kountchev M, Robatscher P, Veerhuis R, Eikelenboom P, Grubeck-Loebenstein B. How chronic inflammation can affect the brain and support the development of Alzheimer's disease in old age: the role of microglia and astrocytes. Aging Cell 2004; 3:169-76. [PMID: 15268750 DOI: 10.1111/j.1474-9728.2004.00101.x] [Citation(s) in RCA: 249] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
A huge amount of evidence has implicated amyloid beta (A beta) peptides and other derivatives of the amyloid precursor protein (beta APP) as central to the pathogenesis of Alzheimer's disease (AD). It is also widely recognized that age is the most important risk factor for AD and that the innate immune system plays a role in the development of neurodegeneration. Little is known, however, about the molecular mechanisms that underlie age-related changes of innate immunity and how they affect brain pathology. Aging is characteristically accompanied by a shift within innate immunity towards a pro-inflammatory status. Pro-inflammatory mediators such as tumour necrosis factor-alpha or interleukin-1 beta can then in combination with interferon-gamma be toxic on neurons and affect the metabolism of beta APP such that increased concentrations of amyloidogenic peptides are produced by neuronal cells as well as by astrocytes. A disturbed balance between the production and the degradation of A beta can trigger chronic inflammatory processes in microglial cells and astrocytes and thus initiate a vicious circle. This leads to a perpetuation of the disease.
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Affiliation(s)
- Imrich Blasko
- Department of Psychiatry, University Hospital of Innsbruck, Innsbruck, Austria
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8
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Tran PK, Tran-Lundmark K, Soininen R, Tryggvason K, Thyberg J, Hedin U. Increased Intimal Hyperplasia and Smooth Muscle Cell Proliferation in Transgenic Mice With Heparan Sulfate–Deficient Perlecan. Circ Res 2004; 94:550-8. [PMID: 14739157 DOI: 10.1161/01.res.0000117772.86853.34] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Smooth muscle cell (SMC) proliferation is a critical process in vascular disease. Heparan sulfate (HS) proteoglycans inhibit SMC growth, but the role of endogenous counterparts in the vessel wall in control of SMC function is not known in detail. Perlecan is the major HS proteoglycans in SMC basement membranes and in vessel wall extracellular matrix (ECM). In this study, transgenic mice with HS-deficient perlecan were analyzed with respect to vascular phenotype and intimal lesion formation. Furthermore, SMC cultures were established and characterized with respect to morphology, immunocytochemical features, proteoglycan synthesis, proliferative capacity, and ECM binding of basic fibroblast growth factor (FGF-2). In vitro, mutant SMCs formed basement membranes with perlecan core protein, but with decreased levels of HS, they showed diminished secretion of HS-containing perlecan into the medium and a defective ECM-binding capacity of FGF-2. In vitro, mutant SMCs showed increased proliferation compared with wild-type cells, and in vivo, enhanced SMC proliferation and intimal hyperplasia were observed after flow cessation of the carotid artery in mutant mice. The results indicate that the endogenous HS side-chains of perlecan contribute to SMC growth control both in vitro and during intimal hyperplasia, possibly by sequestering heparin-binding mitogens such as FGF-2.
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Affiliation(s)
- Phan-Kiet Tran
- Department of Surgical Sciences, Karolinska Hospital, SE-17176 Stockholm, Sweden.
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9
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Blasko I, Grubeck-Loebenstein B. Role of the immune system in the pathogenesis, prevention and treatment of Alzheimer's disease. Drugs Aging 2003; 20:101-13. [PMID: 12534311 DOI: 10.2165/00002512-200320020-00002] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The dysregulation in the metabolism of beta-amyloid precursor protein and consequent deposition of amyloid-beta (Abeta) has been envisaged as crucial for the development of neurodegeneration in Alzheimer's disease (AD). Amyloid deposition begins 10-20 years before the appearance of clinical dementia. During this time, the brain is confronted with increasing amounts of toxic Abeta peptides and data from the last decade intriguingly suggest that both the innate and the adaptive immune systems may play an important role in the disorder. Innate immunity in the brain is mainly represented by microglial cells, which phagocytose and degrade Abeta. As the catabolism of Abeta decreases, glial cells become overstimulated and start to produce substances that are toxic to neurons, such as nitric oxide and inflammatory proteins. Pro-inflammatory cytokines can be directly toxic or stimulate Abeta production and increase its cytotoxicity. A therapeutic possibility arises from clinical studies, which demonstrate that nonsteroidal anti-inflammatory drugs (NSAIDs) may delay the onset and slow the progression of AD. Recent data show that in addition to the suppression of inflammatory processes in the brain NSAIDs may decrease the production of Abeta peptides. The role of adaptive immunity lies mainly in the fact that Abeta can be recognised as an antigen. Immunisation with Abeta peptides and peripheral administration of Abeta-specific antibodies both decrease senile plaques and cognitive dysfunction in murine models of AD. A recent trial in humans seems still to be hampered by adverse effects. As adaptive immunity decreases with aging while innate immunity remains intact, immunotherapy for AD will have to be adapted to this situation. Strategies that combine vaccination and inflammatory drug treatment could be considered.
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Affiliation(s)
- Imrich Blasko
- Department of Psychiatry, University Hospital of Innsbruck, Austria
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10
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Affiliation(s)
- John M Whitelock
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA
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11
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Wick G, Berger P, Jansen-Dürr P, Grubeck-Loebenstein B. A Darwinian-evolutionary concept of age-related diseases. Exp Gerontol 2003; 38:13-25. [PMID: 12543257 DOI: 10.1016/s0531-5565(02)00161-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Humans and animals are structurally designed as a compromise to guarantee optimal survival until the time of reproduction based on natural selection that is effective until that age. Modern conditions of life including improvement of hygiene, preventive and curative medicine as well as socio-economic and political developments have led to an increase of the mean life expectancy that allows ever larger proportions of the population to reach an age that is far beyond that of the reproductive phase. The concept of a Darwinian-evolutionary basis for the development of age-related diseases in principle postulates that genetic traits that are beneficial in younger years to allow for successful reproduction may become deleterious in the elderly, i.e. when selective pressure does not seem to be effective anymore. Examples for this mechanism of pleiotropic antagonism taken from the work of the Institute for Biomedical Aging Research in Innsbruck, Austria, include atherosclerosis, benign and malignant prostate hypertrophy, Alzheimer's disease and the reciprocal relationship between cellular senescence and cancer.
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Affiliation(s)
- Georg Wick
- Institute for Biomedical Aging Research, Austrian Academy of Sciences, Rennweg 10, A-6020 Innsbruck, Austria.
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12
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Lundmark K, Tran PK, Kinsella MG, Clowes AW, Wight TN, Hedin U. Perlecan inhibits smooth muscle cell adhesion to fibronectin: role of heparan sulfate. J Cell Physiol 2001; 188:67-74. [PMID: 11382923 DOI: 10.1002/jcp.1094] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Smooth muscle cell migration, proliferation, and deposition of extracellular matrix are key events in atherogenesis and restenosis development. To explore the mechanisms that regulate smooth muscle cell function, we have investigated whether perlecan, a basement membrane heparan sulfate proteoglycan, modulates interaction between smooth muscle cells and other matrix components. A combined substrate of fibronectin and perlecan showed a reduced adhesion of rat aortic smooth muscle cells by 70-90% in comparison to fibronectin alone. In contrast, perlecan did not interfere with cell adhesion to laminin. Heparinase treated perlecan lost 60% of its anti-adhesive effect. Furthermore, heparan sulfate as well as heparin reduced smooth muscle cell adhesion when combined with fibronectin whereas neither hyaluronan nor chondroitin sulfate had any anti-adhesive effects. Addition of heparin as a second coating to a preformed fibronectin matrix did not affect cell adhesion. Cell adhesion to the 105- and 120 kDa cell-binding fragments of fibronectin, lacking the main heparin-binding domains, was also inhibited by heparin. In addition, co-coating of fibronectin and (3)H-heparin showed that heparin was not even incorporated in the substrate. Morphologically, smooth muscle cells adhering to a substrate prepared by co-coating of fibronectin and perlecan or heparin were small, rounded, lacked focal contacts, and showed poorly developed stress fibers of actin. The results show that the heparan sulfate chains of perlecan lead to altered interactions between smooth muscle cells and fibronectin, possibly due to conformational changes in the fibronectin molecule. Such interactions may influence smooth muscle cell function in atherogenesis and vascular repair processes.
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Affiliation(s)
- K Lundmark
- Department of Surgical Sciences, Division of Vascular Surgery, Karolinska Hospital, SE-171, 76 Stockholm, Sweden.
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13
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Lee RT, Yamamoto C, Feng Y, Potter-Perigo S, Briggs WH, Landschulz KT, Turi TG, Thompson JF, Libby P, Wight TN. Mechanical strain induces specific changes in the synthesis and organization of proteoglycans by vascular smooth muscle cells. J Biol Chem 2001; 276:13847-51. [PMID: 11278699 DOI: 10.1074/jbc.m010556200] [Citation(s) in RCA: 145] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In the mechanically active environment of the artery, cells sense mechanical stimuli and regulate extracellular matrix structure. In this study, we explored the changes in synthesis of proteoglycans by vascular smooth muscle cells in response to precisely controlled mechanical strains. Strain increased mRNA for versican (3.2-fold), biglycan (2.0-fold), and perlecan (2.0-fold), whereas decorin mRNA levels decreased to a third of control levels. Strain also increased versican, biglycan, and perlecan core proteins, with a concomitant decrease in decorin core protein. Deformation did not alter the hydrodynamic size of proteoglycans as evidenced by molecular sieve chromatography but increased sulfate incorporation in both chondroitin/dermatan sulfate proteoglycans and heparan sulfate proteoglycans (p < 0.05 for both). Using DNA microarrays, we also identified the gene for the hyaluronan-linking protein TSG6 as mechanically induced in smooth muscle cells. Northern analysis confirmed a 4.0-fold increase in steady state mRNA for TSG6 following deformation. Size exclusion chromatography under associative conditions showed that versican-hyaluronan aggregation was enhanced following deformation. These data demonstrate that mechanical deformation increases specific vascular smooth muscle cell proteoglycan synthesis and aggregation, indicating a highly coordinated extracellular matrix response to biomechanical stimulation.
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MESH Headings
- Aorta/cytology
- Biglycan
- Blotting, Northern
- Blotting, Western
- Cells, Cultured
- Chondroitin Sulfate Proteoglycans/biosynthesis
- Chondroitin Sulfate Proteoglycans/metabolism
- Chondroitin Sulfates/metabolism
- Chromatography, Agarose
- Decorin
- Electrophoresis, Polyacrylamide Gel
- Extracellular Matrix Proteins
- Heparan Sulfate Proteoglycans/biosynthesis
- Heparitin Sulfate/metabolism
- Humans
- Hyaluronic Acid/metabolism
- Kinetics
- Lectins, C-Type
- Lipoproteins, LDL/metabolism
- Muscle, Smooth, Vascular/cytology
- Oligonucleotide Array Sequence Analysis
- Protein Binding
- Proteoglycans/biosynthesis
- Proteoglycans/metabolism
- RNA, Messenger/metabolism
- Stress, Mechanical
- Time Factors
- Up-Regulation
- Versicans
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Affiliation(s)
- R T Lee
- Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, 02115, USA.
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Castillo GM, Lukito W, Peskind E, Raskind M, Kirschner DA, Yee AG, Snow AD. Laminin inhibition of beta-amyloid protein (Abeta) fibrillogenesis and identification of an Abeta binding site localized to the globular domain repeats on the laminin a chain. J Neurosci Res 2000; 62:451-62. [PMID: 11054814 DOI: 10.1002/1097-4547(20001101)62:3<451::aid-jnr15>3.0.co;2-f] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
beta-Amyloid protein (Abeta) is a major component of neuritic plaques and cerebrovascular amyloid deposits in the brains of patients with Alzheimer's disease (AD). Inhibitors of Abeta fibrillogenesis are currently sought as potential future therapeutics for AD and related disorders. In the present study, the basement membrane protein laminin was found to bind Abeta 1-40 with a single dissociation constant, K(d) = 2.7 x 10(-9) M, and serve as a potent inhibitor of Abeta fibril formation. 25 microM of Abeta 1-40 was incubated at 37 degrees C for 1 week in the presence of 100 nM of laminin or other basement membrane components, including perlecan, type IV collagen, and fibronectin to determine their effects on Abeta fibril formation as evaluated by thioflavin T fluorometry. Of all the basement membrane components tested, laminin demonstrated the greatest inhibitory effect on Abeta-amyloid fibril formation, causing a ninefold inhibition at 1 and 3 days and a 21-fold inhibition at 1 week. The inhibitory effects of laminin on Abeta fibrillogenesis occurred in a dose-dependent manner and were still effective at lower concentrations. The inhibitory effects of laminin on Abeta 1-40 fibril formation was confirmed by negative stain electron microscopy, whereby laminin caused an almost complete inhibition of Abeta fibril formation and assembly by 3 days, resulting in the appearance of primarily amorphous nonfibrillar material. Laminin also caused partial disassembly of preformed Abeta-amyloid fibrils following 4 days of coincubation. Laminin was not effective as an inhibitor of islet amyloid polypeptide fibril formation, suggesting that laminin's amyloid inhibitory effects were Abeta-specific. To identify a potential Abeta-binding site(s) on laminin, laminin was first digested with V8, trypsin, or elastase. An Abeta-binding elastase digestion product of approximately 120-130 kDa was found. In addition, a approximately 55 kDa fragment derived from V8 and elastase-digested laminin interacted with biotinylated Abeta 1-40. Amino acid sequencing of the approximately 55 kDa fragment identified a conformationally dependent Abeta-binding site within laminin localized to the globular repeats on the laminin A chain. These studies demonstrate that laminin not only binds Abeta with relatively high affinity but is a potent inhibitor of Abeta-amyloid fibril formation. In addition, further identification of an Abeta-binding domain within the globular repeats on the laminin A chain may lead to the design of new therapeutics for the inhibition of Abeta fibrillogenesis.
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Affiliation(s)
- G M Castillo
- ProteoTech Inc., Kirkland, Washington 98034, USA.
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Miller JD, Cummings J, Maresh GA, Walker DG, Castillo GM, Ngo C, Kimata K, Kinsella MG, Wight TN, Snow AD. Localization of perlecan (or a perlecan-related macromolecule) to isolated microglia in vitro and to microglia/macrophages following infusion of beta-amyloid protein into rodent hippocampus. Glia 1997; 21:228-43. [PMID: 9336237 DOI: 10.1002/(sici)1098-1136(199710)21:2<228::aid-glia6>3.0.co;2-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The origin of the heparan sulfate proteoglycan (PG), perlecan, in beta-amyloid protein (A beta)-containing amyloid deposits in Alzheimer's disease (AD) brain is not known. In the present investigation we used indirect immunofluorescence, SDS-PAGE, and Western blotting with a specific perlecan core protein antibody to identify possible cell candidates of perlecan production in both primary cell cultures and in a rat infusion model. Double and triple-labeled indirect immunofluorescence was performed on dissociated primary rat septal cultures using antibodies for specific identification of cell types and for perlecan core protein. In mixed cultures of both embryonic day 18 (containing neurons and glia) and postnatal day 2-3 (devoid of neurons), microglia identified by labeling with OX-42 or anti-ED1 were the only cell type also double labeled with an affinity-purified polyclonal antibody against perlecan core protein. Similar immunolabeling of microglia with the anti-perlecan antibody was also observed in purified cultures of post-natal rat microglia. Analyses of PGs from cultured postnatal rat microglia by Western blotting using a polyclonal antibody against perlecan core protein revealed an approximately 400 kDa band in cell layer, which was intensified following heparitinase/heparinase digestion, suggestive of perlecan core protein. Other lower Mr bands were also found implicating either degradation of the 400 kDa core protein or the presence of separate and distinct gene products immunologically related to perlecan. Reverse transcription followed by polymerase chain reaction using human perlecan domain I specific primers demonstrated perlecan mRNA in cultured human microglia derived from postmortem normal aged and AD brain. Following a 1-week continuous infusion of A beta (1-40) into rodent hippocampus, immunoperoxidase immunocytochemistry and double-labeled immunofluorescent studies revealed perlecan accumulation primarily localized to microglia/macrophages within the A beta infusion site. These studies have identified microglia/macrophages as one potential source of perlecan (or a perlecan-related macromolecule) which may be important for the ongoing accumulation of both perlecan and A beta in the amyloid deposits of AD.
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Affiliation(s)
- J D Miller
- Department of Pathology, University of Washington, Seattle 98195-6480, USA
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