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Kidney International Mar 1991Although some progress has been made in recent years, there are truly large gaps in our basic knowledge on how the TBM is assembled during development. Some of the new... (Review)
Review
Although some progress has been made in recent years, there are truly large gaps in our basic knowledge on how the TBM is assembled during development. Some of the new evidence presented here indicates that both the tubular epithelium and interstitial fibroblasts participate in TBM protein biosynthesis during nephrogenesis. In addition, newly assembled segments of TBM are spliced or inserted into existing TBM during tubule expansion and elongation. A similar splicing mechanism has been described previously in the GBM, endocrine organs, and intestinal villi, and this mechanism therefore probably represents a fundamental process of basement membrane formation. A major unresolved question at present, however, is how this mechanism operates at the molecular level. Does the newly formed basement membrane contain identical components as that already present? Since an enzymatic process is likely occurring in the insertion of new matrix into old, which enzymes are involved? What is the cellular origin of these enzymes and which matrix component(s) is their substrate? Even more fundamental yet unanswered questions have to do with the mechanisms of epithelial induction, basement membrane gene activation, and tubular morphogenesis. Once the basement membrane is fully formed at the completion of nephrogenesis, what controls basement membrane turnover and how does this operate? Clearly, much additional research is necessary to address these questions. This work is needed, however, before we can fully understand the important roles basement membranes play in normal development as well as in disease.
Topics: Animals; Basement Membrane; Collagen; Humans; Kidney Tubules; Laminin; Microscopy, Electron; Proteoglycans
PubMed: 2062031
DOI: 10.1038/ki.1991.50 -
Current Biology : CB Mar 2022Building of the Drosophila abdomen relies on the removal of larval cells and expansion, through proliferation, of a population of progenitor epithelial cells. A new...
Building of the Drosophila abdomen relies on the removal of larval cells and expansion, through proliferation, of a population of progenitor epithelial cells. A new study shows that matrix metalloproteinases produced by larval cells drive basement membrane degradation and proliferative growth of the progenitor epithelial population.
Topics: Basement Membrane; Cell Proliferation; Epithelial Cells; Stem Cells
PubMed: 35349814
DOI: 10.1016/j.cub.2022.01.081 -
BioMed Research International 2013The epidermis functions in skin as first defense line or barrier against environmental impacts, resting on extracellular matrix (ECM) of the dermis underneath. Both... (Review)
Review
The epidermis functions in skin as first defense line or barrier against environmental impacts, resting on extracellular matrix (ECM) of the dermis underneath. Both compartments are connected by the basement membrane (BM), composed of a set of distinct glycoproteins and proteoglycans. Herein we are reviewing molecular aspects of BM structure, composition, and function regarding not only (i) the dermoepidermal interface but also (ii) the resident microvasculature, primarily focusing on the per se nonscaffold forming components perlecan and nidogen-1 and nidogen-2. Depletion or functional deficiencies of any BM component are lethal at some stage of development or around birth, though BM defects vary between organs and tissues. Lethality problems were overcome by developmental stage- and skin-specific gene targeting or by cell grafting and organotypic (3D) cocultures of normal or defective cells, which allows recapitulating BM formation de novo. Thus, evidence is accumulating that BM assembly and turnover rely on mechanical properties and composition of the adjacent ECM and the dynamics of molecular assembly, including further "minor" local components, nidogens largely functioning as catalysts or molecular adaptors and perlecan as bridging stabilizer. Collectively, orchestration of BM assembly, remodeling, and the role of individual players herein are determined by the developmental, tissue-specific, or functional context.
Topics: Basement Membrane; Collagen Type IV; Epidermis; Extracellular Matrix; Heparan Sulfate Proteoglycans; Humans; Laminin; Membrane Glycoproteins; Proteoglycans; Skin
PubMed: 23586018
DOI: 10.1155/2013/179784 -
Kidney International Mar 1992
Review
Topics: Animals; Basement Membrane; Humans; Kidney Diseases; Kidney Glomerulus; Membrane Proteins; Molecular Structure
PubMed: 1573839
DOI: 10.1038/ki.1992.95 -
Glycobiology Jul 2015Associations between cells and the basement membrane are critical for a variety of biological events including cell proliferation, cell migration, cell differentiation... (Review)
Review
Associations between cells and the basement membrane are critical for a variety of biological events including cell proliferation, cell migration, cell differentiation and the maintenance of tissue integrity. Dystroglycan is a highly glycosylated basement membrane receptor, and is involved in physiological processes that maintain integrity of the skeletal muscle, as well as development and function of the central nervous system. Aberrant O-glycosylation of the α subunit of this protein, and a concomitant loss of dystroglycan's ability to function as a receptor for extracellular matrix (ECM) ligands that bear laminin globular (LG) domains, occurs in several congenital/limb-girdle muscular dystrophies (also referred to as dystroglycanopathies). Recent genetic studies revealed that mutations in DAG1 (which encodes dystroglycan) and at least 17 other genes disrupt the ECM receptor function of dystroglycan and cause disease. Here, we summarize recent advances in our understanding of the enzymatic functions of two of these disease genes: the like-glycosyltransferase (LARGE) and protein O-mannose kinase (POMK, previously referred to as SGK196). In addition, we discuss the structure of the glycan that directly binds the ECM ligands and the mechanisms by which this functional motif is linked to dystroglycan. In light of the fact that dystroglycan functions as a matrix receptor and the polysaccharide synthesized by LARGE is the binding motif for matrix proteins, we propose to name this novel polysaccharide structure matriglycan.
Topics: Basement Membrane; Dystroglycans; Extracellular Matrix; Mutation; Polysaccharides
PubMed: 25882296
DOI: 10.1093/glycob/cwv021 -
Journal of Cell Science Feb 2011Metastasis, the process by which cells spread from the primary tumor to a distant site to form secondary tumors, is still not fully understood. Although histological... (Review)
Review
Metastasis, the process by which cells spread from the primary tumor to a distant site to form secondary tumors, is still not fully understood. Although histological techniques have provided important information, they give only a static image and thus compromise interpretation of this dynamic process. New advances in intravital microscopy (IVM), such as two-photon microscopy, imaging chambers, and multicolor and fluorescent resonance energy transfer imaging, have recently been used to visualize the behavior of single metastasizing cells at subcellular resolution over several days, yielding new and unexpected insights into this process. For example, IVM studies showed that tumor cells can switch between multiple invasion strategies in response to various densities of extracellular matrix. Moreover, other IVM studies showed that tumor cell migration and blood entry take place not only at the invasive front, but also within the tumor mass at tumor-associated vessels that lack an intact basement membrane. In this Commentary, we will give an overview of the recent advances in high-resolution IVM techniques and discuss some of the latest insights in the metastasis field obtained with IVM.
Topics: Basement Membrane; Cell Movement; Extracellular Matrix; Humans; Microscopy, Fluorescence, Multiphoton; Microscopy, Video; Neoplasm Metastasis; Neoplasms; Neovascularization, Pathologic
PubMed: 21242309
DOI: 10.1242/jcs.072728 -
Journal Francais D'ophtalmologie Mar 2023The treatment of refractory macular holes is controversial, with human amniotic membrane grafts emerging recently as an attractive option. We performed a meta-analysis... (Meta-Analysis)
Meta-Analysis Review
PURPOSE
The treatment of refractory macular holes is controversial, with human amniotic membrane grafts emerging recently as an attractive option. We performed a meta-analysis and systematic review in this paper to assess the results of human amniotic membrane (hAM) in the treatment of refractory macular hole (MH).
METHODS
We searched the Cochrane Database of Systematic Reviews, Web of Science, PubMed, Embase, China National Knowledge Infrastructure databases, VIP database, Wanfang Data Knowledge Service Platform, Sinomed, Chinese Clinical Trial Registry, and Clinical Trials.gov. Studies reporting hAM for the treatment of refractory MH were included. The outcomes are MH closure rate, visual acuity (VA) improvement rate, and graft dislocation/contracture rate.
RESULTS
A total of 8 studies on 103 eyes were included, all of which had undergone failed vitrectomy and internal limiting membrane (ILM) peeling. In all studies, the VA improvement rate was 66% (95%CI: 45 to 84%), the MH closure rate was 94% (95%CI: 84 to 100%) and the hAM graft dislocation/contracture rate was 6% (95%CI: 0 to 15%). In the studies using cryopreserved hAM grafts, the MH closure rate was 99% (95%CI: 94 to 100%) and the hAM graft dislocation/contracture rate was 3% (0%, 10%). The VA improvement rates were 94% (95%CI: 79 to 100%) in the retinal detachment subgroup, 37% (95%CI: 20 to 56%) in the pathologic myopia subgroup, and 62% (95%CI: 14 to 100%) in the idiopathic MH subgroup.
CONCLUSION
Human amniotic membrane in the treatment of refractory MH results in visual improvement. It has a high macular hole closure rate and low dislocation/contracture rate. Cryopreserved hAM grafts might have better outcomes than dehydrated grafts.
Topics: Humans; Amnion; Basement Membrane; Retina; Retinal Detachment; Retinal Perforations; Retrospective Studies; Tomography, Optical Coherence; Vitrectomy
PubMed: 36739260
DOI: 10.1016/j.jfo.2022.07.001 -
The Journal of Investigative... Aug 2009Aging of sun-exposed skin is accelerated by three major environmental factors: UV radiation, dryness, and oxidation. UV radiation exposure is the most influential factor... (Review)
Review
Aging of sun-exposed skin is accelerated by three major environmental factors: UV radiation, dryness, and oxidation. UV radiation exposure is the most influential factor in skin aging (so-called photoaging). To find ways to protect against damage caused by UV exposure and to delay photoaging, we studied internal changes of sun-exposed skin compared with those of sun-protected skin. We found that the basement membrane (BM) at the dermal-epidermal junction (DEJ) of sun-exposed skin becomes damaged and multilayered and partly disrupted compared with that of sun-protected skin. BM plays important roles in maintaining a healthy epidermis and dermis, and repeated damage destabilizes the skin, accelerating the aging process. Matrix metalloproteinases (MMPs) and urinary plasminogen activator are increased in UV-irradiated skin. MMPs are detected in the cornified layer in sun-exposed skin, but not in sun-protected skin. Using skin-equivalent models, we found that MMPs and plasmin cause BM damage and that the reconstruction of BM is enhanced by inhibiting these proteinases, as well as by increasing the synthesis of BM components. Enhancement of BM repair mechanisms may be a useful strategy in retarding photoaging.Journal of Investigative Dermatology Symposium Proceedings (2009) 14, 2-7; doi:10.1038/jidsymp.2009.5.
Topics: Animals; Basement Membrane; Cell Adhesion Molecules; Collagen Type VII; Fibrinolysin; Humans; Matrix Metalloproteinases, Membrane-Associated; Models, Biological; Skin Aging; Kalinin
PubMed: 19675545
DOI: 10.1038/jidsymp.2009.5 -
Ophthalmology Feb 2018Despite posterior vitreous detachment being a common ocular event affecting most individuals in an aging population, there is little consensus regarding its precise...
PURPOSE
Despite posterior vitreous detachment being a common ocular event affecting most individuals in an aging population, there is little consensus regarding its precise anatomic definition. We investigated the morphologic appearance and molecular composition of the posterior hyaloid membrane to determine whether the structure clinically observed enveloping the posterior vitreous surface after posterior vitreous detachment is a true basement membrane and to postulate its origin. Understanding the relationship between the vitreous (in both its attached and detached state) and the internal limiting membrane of the retina is essential to understanding the cause of rhegmatogenous retinal detachment and vitreoretinal interface disorders, as well as potential future prophylactic and treatment strategies.
DESIGN
Clinicohistologic correlation study.
PARTICIPANTS
Thirty-six human donor globes.
METHODS
Vitreous bodies identified to have posterior vitreous detachment were examined with phase-contrast microscopy and confocal microscopy after immunohistochemically staining for collagen IV basement membrane markers, in addition to extracellular proteins that characterize the vitreoretinal junction (fibronectin, laminin) and vitreous gel (opticin) markers. The posterior retina similarly was stained to evaluate the internal limiting membrane. Findings were correlated to the clinical appearance of the posterior hyaloid membrane observed during slit-lamp biomicroscopy after posterior vitreous detachment and compared with previously published studies.
MAIN OUTCOME MEASURES
Morphologic appearance and molecular composition of the posterior hyaloid membrane.
RESULTS
Phase-contrast microscopy consistently identified a creased and distinct glassy membranous sheet enveloping the posterior vitreous surface, correlating closely with the posterior hyaloid membrane observed during slit-lamp biomicroscopy in patients with posterior vitreous detachment. Immunofluorescent confocal micrographs demonstrated the enveloping membranous structure identified on phase-contrast microscopy to show positive stain results for type IV collagen. Immunofluorescence of the residual intact internal limiting membrane on the retinal surface also showed positive stain results for type IV collagen.
CONCLUSIONS
The results of this study provide immunohistochemical evidence that the posterior hyaloid membrane is a true basement membrane enveloping the posterior hyaloid surface. Because this membranous structure is observed only after posterior vitreous detachment, the results of this study indicate that it forms part of the internal limiting membrane when the vitreous is in its attached state.
Topics: Adult; Aged; Aged, 80 and over; Basement Membrane; Collagen; Female; Humans; Imaging, Three-Dimensional; Immunohistochemistry; Male; Microscopy, Acoustic; Microscopy, Confocal; Middle Aged; Prospective Studies; Vitrectomy; Vitreous Body; Vitreous Detachment
PubMed: 28867131
DOI: 10.1016/j.ophtha.2017.08.001 -
Nature Cell Biology Jun 2011Large gaps in basement membrane occur at sites of cell invasion and tissue remodelling in development and cancer. Though never followed directly in vivo, basement...
Large gaps in basement membrane occur at sites of cell invasion and tissue remodelling in development and cancer. Though never followed directly in vivo, basement membrane dissolution or reduced synthesis have been postulated to create these gaps. Using landmark photobleaching and optical highlighting of laminin and type IV collagen, we find that a new mechanism, basement membrane sliding, underlies basement membrane gap enlargement during uterine-vulval attachment in Caenorhabditis elegans. Laser ablation and mutant analysis reveal that the invaginating vulval cells promote basement membrane movement. Further, an RNA interference and expression screen identifies the integrin INA-1/PAT-3 and VAB-19, homologue of the tumour suppressor Kank, as regulators of basement membrane opening. Both concentrate within vulval cells at the basement membrane gap boundary and halt expansion of the shifting basement membrane. Basement membrane sliding followed by targeted adhesion represents a new mechanism for creating precise basement membrane breaches that can be used by cells to break down compartment boundaries.
Topics: Animals; Basement Membrane; Caenorhabditis elegans; Cell Adhesion; Female; Uterus; Vulva
PubMed: 21572423
DOI: 10.1038/ncb2233