Difference between revisions of "Part:BBa K782061"

Latest revision as of 03:45, 2 November 2017

VEGF-p2a-PDGF

Introduction

Experimental data show the important regenerating role of vascular endothelial growth factor (VEGF) after acute myocardial infarction (Banfi et al., 2012; Zhang et al., 2008). After binding to its receptor VEGFR1 and VEGFR2 it supports angiogenesis, inhibits endothelial cell apoptosis, promotes endothelial cell proliferation, and restores heart function. Although therapeutic angiogenesis by delivery of vascular growth factors is an attractive strategy, many clinical trials have thus far failed to show efficacy. One of the most likely explanations for this discrepancy is that VEGF induces growth of dysfunctional vessels, if expressed outside of a narrow dosage window (Banfi et al., 2012). Banfi et al. confirmed the hypothesis that co-delivery of platelet-derived growth factor-BB (PDGF-BB), which recruits pericytes, induced normal angiogenesis in skeletal muscle irrespective of VEGF levels. It was also shown that coexpression of VEGF and PDGF-BB encoded by separate vectors in different cells or in the same cells only partially corrected aberrant angiogenesis. In marked contrast, coexpression of both factors in every cell at a fixed relative level via a single bicistronic vector led to robust, uniformly normal angiogenesis, even when VEGF expression was high and heterogeneous. We therefore prepared and deposited a fusion of VEGF and PDGF-BB, joined through a p2a sequence in frame between the two coding protein coding sequences (figure 1). This allows concurrent stoichiometric production of these proteins (Szymczak et al., 2004).

Figure 1. Shematic representation of VEGF and PDGF linked with p2A.

• VEGF and PDGF-BB were obtained from Sino Biological Inc.

Improvement by SYSU-CHINA 2017

In iGEM 2017, SYSU-CHINA improved the part by submitting a basic part version of VEGF-A121 Part:BBa_K2298001 for teams in the future, so that they can use this growth factor alone or in combination with other growth factors other than PDGF. In addition, the VEGF coding sequence in this part was from mouse(Mus musculus). So SYSU-CHINA submitted the counterpart in human(Homo sapiens), which may be more appropriate for experiments using human cell lines as well as clinical applications.

SYSU-CHINA also provided some data demonstrating the efficacy of VEGF-A121 in wound healing.

Feel free to check out our new basic part Part:BBa_K2298001!

Refrences

Banfi, A., von Degenfeld, G., Gianni-Barrera, R., Reginato, S., Merchant, M.J., McDonald, D.M., and Blau, H.M. (2012) Therapeutic angiogenesis due to balanced single-vector delivery of VEGF and PDGF-BB. FASEB J. 26, 2486-2497.

Szymczak, A.L., Workman, C.J., Wang, Y., Vignali, K.M., Dilioglou, S., Vanin, E.F., Vignali D.A. (2004) Correction of multi-gene deficiency in vivo using a single 'self-cleaving' 2A peptide-based retroviral vector. Nat. Biotechnol. 22, 589-94.

Zhang, H., Zhu, S.J., Wang, W., Wei, Y.J., and Hu, S.S. (2008) Transplantation of microencapsulated genetically modified xenogeneic cells augments angiogenesis and improves heart function. Gene Ther. 15, 40-48.

Sequence and Features