Basement membranes receptors

Certain proteoglycans (eg, heparan sulfate) are associated with the plasma membrane of cells, with their core proteins acmally spanning that membrane. In it they may act as receptors and may also participate in the mediation of cell growth and cell-cell communication. The attachment of cells to their substramm in cul-mre is mediated at least in part by heparan sulfate. This proteoglycan is also found in the basement membrane of the kidney along with type IV collagen and laminin... 

Fig. 2.14 Cellular morphology of neuroepithelium chemosensory groove in lamellae of the African lungfish Protopterus annectens (Dipnoan) basal, receptor and supporting cells (CB, CRe and CS) MB basement membrane. Owen, x400 (from Derivot, 1984).

It has been known for some time that the enteric nervous system does not simply regulate smooth muscle contraction, but is intimately involved in the control of transport processes in enterocytes. Nerve fibres in the mucosa terminate subjacent to the basement membrane of epithelial and entero-endocrine cells, on which muscarinic acetylcholine receptors (mAChRs)... 

Pericytes lie periendothelially on the abluminal side of the microvessels (Figure 15.3). A layer of basement membrane separates the pericytes from the endothelial cells and the astrocyte foot processes. Pericytes send out cell processes which penetrate the basement membrane and cover around 20-30% of the micro-vascular circumference [18]. Pericyte cytoplasmic projections encircling the endothelial cells provide both a vasodynamic capacity and structural support to the microvasculature. They bear receptors for vasoactive mediators such as catecholamines, endothelin-1, VIP, vasopressin and angiotensin II. Pericytes become mark-... 

Cell attachment to the glomerular basement membrane is mediated by laminin, entactin, and fibronectin, at least partly through integrin receptors on the cell surface of both endothelial and visceral epithelial cells. 

Nakamura, A., T. Yuasa, A. Ujike, M. Ono, T. Nukiwa, J. V. Ravetch, and T. Takai. 2000. Fcgamma receptor IIB-deficient mice develop Goodpasture s syndrome upon immunization with type IV collagen a novel murine model for autoimmune glomerular basement membrane disease. J. Exp. Med. 191 899-906. 

Recent studies have shown that all basement membranes contain a unique collagen arranged in an unusual network structure as well as certain glycoproteins and proteoglycans that occur only in basement membranes (Laurie et al., 1983). The cooccurrence of these proteins in basement membranes is due both to their synthesis by the cells that lie along the basement membrane and to strong and specific interactions that maintain the components together in situ. Also, the cells on basement membranes have specific receptors for these components (Yamada, 1983 von der Mark and Kiihl, 1985 Kleinman et al., 1985 Martin and Timpl, 1987). 

Nagamatsu et al. (1999) found beneficial effects of an angiotensin II type I receptor antagonist in anti-glomerular basement membrane antibody-associated nephritis in rats. 

---