Inhibitor Biologie

The kidney develops from the embryonic mesoderm, which bone and muscle cells also originate from.This structure is composed of undifferentiated mesenchymal cells, which are defined as loose connective tissue with the ability to be motile.The mesoderm then star ts to dif ferentiate into nephrons by forming an early epithelium during epithelial mesenchymaltransformat ion. Th is early epithel ium consists of newly Granisetron hydrochloride polarized cells, with a basement membrane and initial lumen formation.Additionally, the cellcell junction represented by the slit diaphragm is not a typical epithelial tight junction, but is described as a modified adherens junction.Thus, we may ask what the phenotype of the fully matu re podocy teis. Th isfind ing raises intr igu ing questions about what additional features of differentiated mesenchymal cells the mature podocyte might have acquired, and how this relates to the functional capacities of the cell.In addition, the cell body and major and secondaryfoot processes containviment inr ich intermediate filaments, and the larger microtubules are known to form organized structures along the major and secondary processes.Intermediate filaments are tensionbearing elements that help to maintain cell shape and rigidity.The contractile system of the foot processes by way of intermediate proteins attaching to collagenIV, fibronectin and laminin, thus forming stabilizing attachment patches that counteract GBM distension.Microtubules form a dynamic intracellular cytoskeletal network that has a number of roles, including regulating cell motility, vesicular Pancuronium bromide transport, maintaining cell shape and polarity, and organization and positioning of membrane organelles.Microtubules are polymers of tubulin and tubulin that grow and shrink in a highly regu lated fashion, via the interact ion with numerous microtubu leassociated proteins, in response to both extracellular and intracellular signals.In cultured human podocytes, we have shown that as the cells differenti ate, they upregu late expression of genes and proteins consistent with a highly differentiated smooth muscle phenotype.These proteins include smoothelin, calpon in and myo card in, wh ich are also expre ss ed in the mature humanglomeru lus exc lus ive ly in podo cytes.The other striking functionalana logy we found between podocytes and smooth muscle cells is the uptake of glucose in response to insulin, a response found in a very limited subset of cells in the body, and which kinetically is identical to smooth muscle cells.Therefore, it can be convincingly speculated that the podocyte is analogous to capillary pericytes, which are elongated contractile cells that wrap around precapillary arterioles outside the basement membrane.Importantly, pericytes have been shown to control capillary diameter in the central nervous system.Electrical stimulation of retinal pericytes evoked a localized capillary constriction, which propagated at ms to constrict distant pericytes.Interestingly, ischemia also resulted in constriction of the capillaries, which might be an important ana logyin understand ing the control ofglomeru lar blood flow during renal ischemia.On the basis of obser vations of limited physiological motility of podocytes invivo and invitro, and changes in the podocyte migratoryphenotype under cer tain experimental conditions, it could be postulated that in nephrotic syndromes there is a spectrum of migratoryand associated contractile changes to the normal podocyte that reflect the specific changes in cytoskeletal dynamics in those conditions.

Leave a Reply