scholarly journals Regulation of cellular functions by extracellular matrix.

1992 ◽  
Vol 2 (10) ◽  
pp. S83 ◽  
Author(s):  
A Teti

Multicellular organisms are formed by specialized cells assembled in tissues. Individual cells contact and interact with other cells and with the extracellular matrix--a network of secreted proteins and carbohydrates that fills the intercellular spaces. The extracellular matrix helps cells to bind together and regulates a number of cellular functions, such as adhesion, migration, proliferation, and differentiation. It is formed by macromolecules, locally secreted by resident cells. The two main classes of macromolecules are polysaccharide glycosaminoglycans, usually covalently linked to proteins in the form of proteoglycans, and fibrous proteins of two functional types, structural (collagen, elastin) and adhesive (fibronectin, laminin, vitronectin, etc.). Receptors for extracellular matrix macromolecules are present in virtually all of the cells studied. They belong to the superfamily of integrins, alpha beta heterodimers, which, in most cases, recognize the Arg-Gly-Asp sequence of extracellular matrix proteins. On the exterior side of the cell, integrins link an extracellular matrix macromolecule, whereas in the cytosol, they bind the cytoskeleton, thereby forming a membrane bridge between extracellular and intracellular fibers. This structure enables the cell to adhere to the substratum. Similar to hormone- or growth factor-receptor binding, the interaction of the integrin with its specific ligand induces immediate signal transduction and influences cellular activities.

Parasitology ◽  
1999 ◽  
Vol 119 (4) ◽  
pp. 331-336 ◽  
Author(s):  
A. ADINI ◽  
A. WARBURG

Plasmodium ookinetes are elongate, motile and invasive while inside the mosquito gut but promptly metamorphose into spherical immobile oocysts upon coming in contact with the basement membrane surrounding the midgut. There they begin a prolonged growth period characterized by massive DNA synthesis for the production of sporozoites. Living Plasmodium gallinaceum ookinetes attached avidly to the murine extracellular matrix proteins, laminin and collagen type IV. In ELISA-type assays, the main ookinete surface protein, Pgs28 was implicated as a mediator of parasite attachment to these basement membrane constituents. Laminin and collagen IV adhered to ookinete and oocyst lysates spotted onto nitrocellulose membranes. Receptor–ligand blot assays demonstrated that Pgs28 and an oocyst-specific antigen recognized by the mAb 10D6 interact with murine collagen IV and laminin. 10D6 antigen was also recognized by monospecific antiserum against the human epidermal growth factor receptor. Mosquito-derived laminin was incorporated into oocyst capsules of P. gallinaceum growing in Aedes aegypti. We hypothesize that contact with the mosquito basement membrane triggers the transformation of ookinetes into oocysts. Coalescence of basement membrane proteins onto the capsules masks developing oocysts from the mosquito's immune system and facilitates their prolonged extracellular development in the mosquito body cavity.


PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9066 ◽  
Author(s):  
Binghui Liu ◽  
Ling Leng ◽  
Xuer Sun ◽  
Yunfang Wang ◽  
Jie Ma ◽  
...  

Extracellular matrix (ECM) proteins play an essential role in various biological processes in multicellular organisms, and their abnormal regulation can lead to many diseases. For large-scale ECM protein identification, especially through proteomic-based techniques, a theoretical reference database of ECM proteins is required. In this study, based on the experimentally verified ECM datasets and by the integration of protein domain features and a machine learning model, we developed ECMPride, a flexible and scalable tool for predicting ECM proteins. ECMPride achieved excellent performance in predicting ECM proteins, with appropriate balanced accuracy and sensitivity, and the performance of ECMPride was shown to be superior to the previously developed tool. A new theoretical dataset of human ECM components was also established by applying ECMPride to all human entries in the SwissProt database, containing a significant number of putative ECM proteins as well as the abundant biological annotations. This dataset might serve as a valuable reference resource for ECM protein identification.


Author(s):  
L. Terracio ◽  
A. Dewey ◽  
K. Rubin ◽  
T.K. Borg

The recognition and interaction of cells with the extracellular matrix (ECM) effects the normal physiology as well as the pathology of all multicellular organisms. These interactions have been shown to influence the growth, development, and maintenance of normal tissue function. In previous studies, we have shown that neonatal cardiac myocytes specifically interacts with a variety of ECM components including fibronectin, laminin, and collagens I, III and IV. Culturing neonatal myocytes on laminin and collagen IV induces an increased rate of both cell spreading and sarcomerogenesis.


1997 ◽  
Vol 10 (01) ◽  
pp. 6-11 ◽  
Author(s):  
R. F. Rosenbusch ◽  
L. C. Booth ◽  
L. A. Dahlgren

SummaryEquine tendon fibroblasts were isolated from explants of superficial digital flexor tendon, subcultured and maintained in monolayers. The cells were characterized by light microscopy, electron microscopy and radiolabel studies for proteoglycan production. Two predominant cell morphologies were identified. The cells dedifferentiated toward a more spindle shape with repeated subcultures. Equine tendon fibroblasts were successfully cryopreserved and subsequently subcultured. The ability to produce proteoglycan was preserved.The isolated cells were identified as fibroblasts, based on their characteristic shape by light microscopy and ultrastructure and the active production of extracellular matrix proteins. Abundant rough endoplasmic reticulum and the production of extracellular matrix products demonstrated active protein production and export. Proteoglycans were measurable via liquid scintillation counting in both the cell-associated fraction and free in the supernatant. This model is currently being utilized to study the effects of polysulfated glycosaminoglycan on tendon healing. Future uses include studying the effects of other pharmaceuticals, such as hyaluronic acid, on tendon healing.A model was developed for in vitro investigations into tendon healing. Fibroblasts were isolated from equine superficial digital flexor tendons and maintained in monolayer culture. The tenocytes were characterized via light and electron microscopy. Proteoglycan production was measured, using radio-label techniques. The fibroblasts were cryopreserved and subsequently subcultured. The cells maintained their capacity for proteoglycan production, following repeated subculturing and cryopreservation.


2004 ◽  
Vol 216 (03) ◽  
Author(s):  
U Schüller ◽  
W Hartmann ◽  
A Koch ◽  
K Schilling ◽  
OD Wiestler ◽  
...  

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