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Nature Reviews. Cancer Oct 2017Metaplasia is the replacement of one differentiated somatic cell type with another differentiated somatic cell type in the same tissue. Typically, metaplasia is... (Review)
Review
Metaplasia is the replacement of one differentiated somatic cell type with another differentiated somatic cell type in the same tissue. Typically, metaplasia is triggered by environmental stimuli, which may act in concert with the deleterious effects of microorganisms and inflammation. The cell of origin for intestinal metaplasia in the oesophagus and stomach and for pancreatic acinar-ductal metaplasia has been posited through genetic mouse models and lineage tracing but has not been identified in other types of metaplasia, such as squamous metaplasia. A hallmark of metaplasia is a change in cellular identity, and this process can be regulated by transcription factors that initiate and/or maintain cellular identity, perhaps in concert with epigenetic reprogramming. Universally, metaplasia is a precursor to low-grade dysplasia, which can culminate in high-grade dysplasia and carcinoma. Improved clinical screening for and surveillance of metaplasia might lead to better prevention or early detection of dysplasia and cancer.
Topics: Adaptation, Biological; Animals; Barrett Esophagus; Epigenesis, Genetic; Epithelium; Gastric Mucosa; Humans; Intestinal Mucosa; Metaplasia; Mucous Membrane; Respiratory Mucosa; Transcription Factors
PubMed: 28860646
DOI: 10.1038/nrc.2017.68 -
The Journal of Membrane Biology Jun 2018Biomembranes assemble and operate at the interface with electrolyte solutions. Interactions between ions in solutions and the lipid affect the membrane structure,...
Biomembranes assemble and operate at the interface with electrolyte solutions. Interactions between ions in solutions and the lipid affect the membrane structure, dynamics and electrostatic potential. In this article, I review some of the experimental and computational methods that are used to study membrane-ions interactions. Experimental methods that account for membrane-ion interactions directly and indirectly are presented first. Then, studies in which molecular dynamics simulations were used to gain an understanding of membrane-ion interactions are surveyed. Finally, the current view on membrane-ion interactions and their significance is briefly discussed.
Topics: Ions; Magnetic Resonance Spectroscopy; Membranes; Molecular Dynamics Simulation
PubMed: 29330605
DOI: 10.1007/s00232-017-0010-y -
Biology Open Aug 2023The basement membrane (BM) is a thin, planar-organized extracellular matrix that underlies epithelia and surrounds most organs. During development, the BM is highly... (Review)
Review
The basement membrane (BM) is a thin, planar-organized extracellular matrix that underlies epithelia and surrounds most organs. During development, the BM is highly dynamic and simultaneously provides mechanical properties that stabilize tissue structure and shape organs. Moreover, it is important for cell polarity, cell migration, and cell signaling. Thereby BM diverges regarding molecular composition, structure, and modes of assembly. Different BM organization leads to various physical features. The mechanisms that regulate BM composition and structure and how this affects mechanical properties are not fully understood. Recent studies show that precise control of BM deposition or degradation can result in BMs with locally different protein densities, compositions, thicknesses, or polarization. Such heterogeneous matrices can induce temporospatial force anisotropy and enable tissue sculpting. In this Review, I address recent findings that provide new perspectives on the role of the BM in morphogenesis.
Topics: Basement Membrane; Morphogenesis; Extracellular Matrix; Cell Movement
PubMed: 37531197
DOI: 10.1242/bio.059980 -
Biochimica Et Biophysica Acta.... Mar 2023Proteins can organize into dynamic, functionally important assemblies on fluid membrane surfaces. Phase separation has emerged as an important mechanism for forming such... (Review)
Review
Proteins can organize into dynamic, functionally important assemblies on fluid membrane surfaces. Phase separation has emerged as an important mechanism for forming such protein assemblies on the membrane during cell signaling, endocytosis, and cytoskeleton regulation. Protein-protein phase separation thus adds novel fluid mosaics to the classical Singer and Nicolson model. Protein condensates formed in this process can modulate membrane morphologies. This is evident from recent reports of protein condensate-driven membrane reshaping in processes such as endocytosis, autophagosome formation, and protein storage vacuole morphogenesis in plants. Lateral phase separation (on the membrane surface) of peripheral curvature coupling proteins can modulate such membrane morphological transitions. Additionally, three-dimensional protein phase separation can result in droplets that through adhesion can affect membrane shape changes. How do these condensate-driven curvature generation mechanisms contrast with the classically recognized scaffolding and amphipathic helix insertion activities of specific membrane remodeling proteins? A salient feature of these condensate-driven membrane activities is that they depend upon both macroscopic features (such as interfacial energies of the condensate, membrane, and cytosol) as well as microscopic, molecular-level interactions (such as protein-lipid binding). This review highlights the current understanding of the mechanisms underlying curvature generation by protein condensates in various biological pathways.
Topics: Membrane Proteins; Membranes
PubMed: 36642341
DOI: 10.1016/j.bbamem.2023.184121 -
Journal of Structural Biology Oct 2016In bacteria the ability to remodel membrane underpins basic cell processes such as growth, and more sophisticated adaptations like inter-cell crosstalk, organelle... (Review)
Review
In bacteria the ability to remodel membrane underpins basic cell processes such as growth, and more sophisticated adaptations like inter-cell crosstalk, organelle specialisation, and pathogenesis. Here, selected examples of membrane remodelling in bacteria are presented and the diverse mechanisms for inducing membrane fission, fusion, and curvature discussed. Compared to eukaryotes, relatively few curvature-inducing proteins have been characterised so far. Whilst it is likely that many such proteins remain to be discovered, it also reflects the importance of alternative membrane remodelling strategies in bacteria where passive mechanisms for generating curvature are utilised.
Topics: Bacteria; Membrane Proteins; Membranes
PubMed: 27265614
DOI: 10.1016/j.jsb.2016.05.010 -
Experimental Eye Research Sep 2020Integrins mediate adhesion of cells to substrates and maintain tissue integrity by facilitating mechanotransduction between cells, the extracellular matrix, and gene... (Review)
Review
Integrins mediate adhesion of cells to substrates and maintain tissue integrity by facilitating mechanotransduction between cells, the extracellular matrix, and gene expression in the nucleus. Changes in integrin expression in corneal epithelial cells and corneal endothelial cells impacts their adhesion to the epithelial basement membrane (EpBM) and Descemet's membrane, respectively. Integrins also play roles in assembly of basement membranes by both activating TGFβ1 and other growth factors. Over the past two decades, this knowledge has been translated into methods to grow corneal epithelial and endothelial cells in vitro for transplantation in the clinic thereby transforming clinical practice and quality of life for patients. Current knowledge on the expression and function of the integrins that mediate adhesion to the basement membrane expressed by corneal epithelial and endothelial cells in health and disease is summarized. This is the first review to discuss similarities and differences in the integrins expressed by both cell types.
Topics: Basement Membrane; Descemet Membrane; Endothelium, Corneal; Epithelium, Corneal; Extracellular Matrix; Humans; Integrins
PubMed: 32712184
DOI: 10.1016/j.exer.2020.108138 -
Biomacromolecules Aug 2022Advancements in the field of tissue engineering have led to the elucidation of physical and chemical characteristics of physiological basement membranes (BM) as... (Review)
Review
Advancements in the field of tissue engineering have led to the elucidation of physical and chemical characteristics of physiological basement membranes (BM) as specialized forms of the extracellular matrix. Efforts to recapitulate the intricate structure and biological composition of the BM have encountered various advancements due to its impact on cell fate, function, and regulation. More attention has been paid to synthesizing biocompatible and biofunctional fibrillar scaffolds that closely mimic the natural BM. Specific modifications in biomimetic BM have paved the way for the development of models like alveolar-capillary barrier, airway models, skin, blood-brain barrier, kidney barrier, and metastatic models, which can be used for personalized drug screening, understanding physiological and pathological pathways, and tissue implants. In this Review, we focus on the structure, composition, and functions of BM and the ongoing efforts to mimic it synthetically. Light has been shed on the advantages and limitations of various forms of biomimetic BM scaffolds including porous polymeric membranes, hydrogels, and electrospun membranes This Review further elaborates and justifies the significance of BM mimics in tissue engineering, in particular in the development of organ model systems.
Topics: Basement Membrane; Cell Differentiation; Extracellular Matrix; Skin; Tissue Engineering; Tissue Scaffolds
PubMed: 35839343
DOI: 10.1021/acs.biomac.2c00402 -
Cells Feb 2023With a history of more than 100 years of different applications in various scientific fields, the chicken chorioallantoic membrane (CAM) assay has proven itself to be an... (Review)
Review
With a history of more than 100 years of different applications in various scientific fields, the chicken chorioallantoic membrane (CAM) assay has proven itself to be an exceptional scientific model that meets the requirements of the replacement, reduction, and refinement principle (3R principle). As one of three extraembryonic avian membranes, the CAM is responsible for fetal respiration, metabolism, and protection. The model provides a unique constellation of immunological, vascular, and extracellular properties while being affordable and reliable at the same time. It can be utilized for research purposes in cancer biology, angiogenesis, virology, and toxicology and has recently been used for biochemistry, pharmaceutical research, and stem cell biology. Stem cells and, in particular, mesenchymal stem cells derived from adipose tissue (ADSCs) are emerging subjects for novel therapeutic strategies in the fields of tissue regeneration and personalized medicine. Because of their easy accessibility, differentiation profile, immunomodulatory properties, and cytokine repertoire, ADSCs have already been established for different preclinical applications in the files mentioned above. In this review, we aim to highlight and identify some of the cross-sections for the potential utilization of the CAM model for ADSC studies with a focus on wound healing and tissue engineering, as well as oncological research, e.g., sarcomas. Hereby, the focus lies on the combination of existing evidence and experience of such intersections with a potential utilization of the CAM model for further research on ADSCs.
Topics: Animals; Stem Cell Research; Chorioallantoic Membrane; Tissue Engineering; Adipose Tissue
PubMed: 36831259
DOI: 10.3390/cells12040592 -
Frontiers in Endocrinology 2022The fetal membranes healing is a complex and dynamic process of replacing devitalized and missing cellular structures and tissue layers. Multiple cells and extracellular... (Review)
Review
The fetal membranes healing is a complex and dynamic process of replacing devitalized and missing cellular structures and tissue layers. Multiple cells and extracellular matrices, and cell differentiation, migration and proliferation may participate in restoring the integrity of damaged tissue, however this process still remains unclear. Therefore, there is a need to identify and integrate new ideas and methods to design a more effective dressing to accelerate fetal membrane healing. This review explores the function and role of galectins in the inflammatory, epithelial mesenchymal transition, proliferative migration, and remodeling phases of fetal membrane healing. In conclusion, the preliminary findings are promising. Research on amnion regeneration is expected to provide insight into potential treatment strategies for premature rupture of membranes.
Topics: Amnion; Extracellular Matrix; Extraembryonic Membranes; Galectins; Humans; Wound Healing
PubMed: 36017312
DOI: 10.3389/fendo.2022.941029 -
Experimental Eye Research May 2020Basement membranes are highly specialized extracellular matrices. More than providing scaffolds, basement membranes are recognized as dynamic and versatile structures... (Review)
Review
Basement membranes are highly specialized extracellular matrices. More than providing scaffolds, basement membranes are recognized as dynamic and versatile structures that modulate cellular responses to regulate tissue development, function, and repair. Increasing evidence suggests that, in addition to providing structural support to adjacent cells, basement membranes serve as reservoirs and modulators of growth factors that direct and fine-tune cellular functions. Since the corneal stroma is avascular and has a relatively low keratocyte density, it's likely that the corneal BM is different in composition from the BMs in other tissues. BMs are composed of a diverse assemblage of extracellular molecules, some of which are likely specific to the tissue where they function; but in general they are composed of four primary components-collagens, laminins, heparan sulfate proteoglycans, and nidogens-in addition to other components such as thrombospondin-1, matrilin-2, and matrilin-4 and fibronectin. Severe injuries to the cornea, including infection, surgery, and trauma, may trigger the development of myofibroblasts and fibrosis in the normally transparent connective tissue stroma. Ultrastructural studies have demonstrated that defective epithelial basement membrane (EBM) regeneration after injury to the cornea underlies the development of myofibroblasts from both bone marrow- and keratocyte-derived precursor cells. Defective EBM permits epithelium-derived and tear-derived transforming growth factor beta (TGF-β), platelet-derived growth factor (PDGF), and possibly other modulators, to penetrate the stroma at sustained levels necessary to drive the development and persistence of vimentin + alpha-smooth muscle actin + desmin+ (V + A + D+) mature myofibroblasts. A recent discovery that has contributed to our understanding of haze development is that keratocytes and corneal fibroblasts produce critical EBM components, such as nidogen-1, nidogen-2 and perlecan, that are essential for complete regeneration of a normal EBM once laminin secreted by epithelial cells self-polymerizes into a nascent EBM. Mature myofibroblasts that become established in the anterior stroma are a barrier to keratocyte/corneal fibroblast contributions to the nascent EBM. These myofibroblasts, and the opacity they produce, often persist for months or years after the injury. Transparency is subsequently restored if the EBM is fully regenerated, myofibroblasts are deprived of TGF-β and undergo apoptosis, and keratocytes reoccupy the anterior stroma and reabsorb the disordered extracellular matrix.
Topics: Animals; Basement Membrane; Cornea; Corneal Diseases; Extracellular Matrix Proteins; Fibrosis; Humans; Regeneration
PubMed: 32179076
DOI: 10.1016/j.exer.2020.108002