Cellular adhesion proteins

In recent years, a large number of new biochemical prognostic markers have been described for cancer. These include steroid receptors, cellular or c-onco-genes, suppressor genes, and molecules directly involved in metastasis, such as proteases and adhesion proteins. 

Elevated concentrations of TNF have been found in the joints of RA patients and the stools of Crohn disease patients and correlate with elevated disease activity. In Crohn disease, infliximab reduces infiltration of inflammatory cells and TNF production in inflamed areas of the intestine and reduces the proportion of mononuclear cells from the lamina propria able to express TNF and interferon. In RA, treatment with infliximab reduced infiltration of inflammatory cells into inflamed areas of the joint as well as expression of molecules mediating cellular adhesion and vascular cell adhesion molecule-1, chemoattraction, and tissue degradation. After treatment with infliximab, patients with Crohn disease or RA have decreased levels of serum IL-6 and C-reactive protein compared with baseline. 

Moreover, currently, inflammation is being implicated as a driving force in the diabetic atherothromboembolic process. Increased concentrations of inflammatory markers such as C-reactive protein, tumor necrosis factor-alpha, platelet-derived soluble CD40 ligand, and upregulation of cellular adhesion molecules have been noted in blood samples of diabetic patients (7-10), and are a subject of great interest. 

Blood serum, usually bovine-derived (calf or fetal bovine), contains amino acids, growth factors, vitamins, proteins, hormones, lipids, and minerals, among other components, as indicated in Table 5.3. Besides fetal bovine serum, serum from horse (equine), and even from humans (less common) can also be used. The main functions of serum are to stimulate growth and other cellular activities through hormones and growth factors, to increase cellular adhesion through specific proteins, and to supply proteins for the transport of hormones, minerals, and lipids (Freshney, 2005). Supplementation with bovine fetal serum is performed at concentrations from 2 to 20% in volume. 

Fig. 8. Schematic representation of protein-mediated cell adhesion on biomaterial surfaces. Biomaterial surface properties (such as hydrophilicity/hydrophobicity, topography, energy, and charge) affect subsequent interactions of adsorbed proteins these interactions include but are not limited to adsorbed protein type, concentration, and conformation. Changes in protein-surface interactions may alter accessibility of adhesive domains (such as the peptide sequence arginine-glycine-aspartic acid) to cells (such as osteoblasts, fibroblasts, or endothelial cells) and thus modulate cellular adhesion. (Adapted and redrawn from Schakenraad, 1996.)...

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