Endothelial cell specific promoter

Vascular gene therapy Transfer of dominant-negative receptors or suicide genes under the control of angiogenic endothelial cell specific promoters... 

Figure 12.9 Endothelial cell-specific nuclear import of plasmids. Growth-arrested African Green Monkey kidney epithelial cells (TC7), human pulmonary artery smooth muscle cells (HSMCs) and human umbilical vein endothelial cells (HUYECs) were microinjected in the nucleus (top) and cytoplasm with CMV-driven, GFP-expressing plasmids containing either no additional sequences (open bars), the SV40 enhancer (striped bars), or the flk-1 promoter (shaded bars). Eight hours after injection, the cells were visualized for GFP expression by fluorescence microscopy. Whereas all three plasmids supported GFP expression when delivered into the nucleus of all three cell types, only the SV40 enhancer mediated nuclear import and gene expression in all cells when injected into the cytoplasm. As predicted, the flk-1 promoter caused import and expression only in cells in which transcription factors necessary for its expression and import were made, namely endothelial cells.

R. T. Jaggar, H. Y. Chan, A. L. Harris, and R. Bicknell, Endothelial cell-specific expression of tumor necrosis factor-alpha from the KDR or E-selectin promoters following retroviral delivery, Hum. Gene Ther. 8 2239 (1997). 

Beyond roles of chemokine receptors in hematopoiesis and innate immunity, roles for chemokines in adaptive immunity emerged. Moreover, other nonleukocyte migration properties of chemokine receptors have been identified. These include roles in the biology of endothelial cells (Chapter 15), cancer (Chapter 16), smooth muscle (Chapter 11), fibroblasts (Chapter 14), stem cells (Chapter 8), and all cell types associated with nervous system tissues (Chapter 17). In many instances, broad functional overlap is evident as chemokines can direct the migration of these cells just as they do with leukocytes. In certain instances, the ability of chemokines to retain cell populations within a specific microenvironment is as important as their migration-promoting properties. However, it is also clear that migration and retention are not the sole end points. 

Utilization of cell-specific peptide sequences in biomaterials enables the selective adhesion of certain cell types, even in the presence of a mixture of many cell types. As mentioned earlier, REDV promotes the adhesion of endothelial cells, but not other vascular cell types (Hubbell et al., 1991). This selectivity has great potential for endothelialization of vascular devices, where the growth of an endothelial cells, but not fibroblasts or smooth muscle cells, is desired. Another peptide sequence, KRSR, has been shown to selectively promote the adhesion of osteoblasts, which is useful in the rational design of better dental and orthopedic biomaterials (Dee et al., 1998). 

Protein C. This vitamin K-dependent glycoprotein serine protease zymogen is produced in the liver. It is an anticoagulant with species specificity (19—21). Protein C is activated to Protein Ca by thrombomodulin, a protein that resides on the surface of endothelial cells, plus thrombin in the presence of calcium. In its active form, Protein Ca selectively inactivates, by proteolytic degradation, Factors V, Va, VIII, and Villa. In this reaction the efficiency of Protein Ca is enhanced by complex formation with free Protein S. In addition, Protein Ca activates tissue plasminogen activator, which promotes the conversion of plasminogen [9001-91-6] to plasmin [9001-90-5]. 

Select proteins that mediate adhesion of specific anchorage-dependent cells (such as osteoblasts, fibroblasts, and endothelial cells) on substrate surfaces have been identified (Underwood and Bennett, 1989 Thomas et al., 1997 Ayad et al, 1994). For example, adsorption of fibronectin and vitronectin on tissue-culture polystryene subsequently enhanced osteoblast, fibroblast, and endothelial cell adhesion (Underwood and Bennett, 1989). More importantly, fibronectin and vitronectin adsorption on borosilicate glass, in a competitive environment, maximized fibroblast and osteoblast adhesion, respectively (Thomas et al., 1997). Ayad et al. (1994) reported that enhanced adsorption of laminin on tissue-culture polystyrene promoted subsequent endothelial cell adhesion. These studies provided evidence that adsorption of specific protein(s) can, subsequently, control select cell adhesion on material surfaces. 

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