TY - JOUR
T1 - Induction of angiogenesis by implantation of encapsulated primary myoblasts expressing vascular endothelial growth factor
AU - Springer, Matthew L.
AU - Hortelano, Gonzalo
AU - Bouley, Donna M.
AU - Wong, Jason
AU - Kraft, Peggy E.
AU - Blau, Helen M.
N1 - Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2000
Y1 - 2000
N2 - Background: We previously demonstrated that intramuscular implantation of primary myoblasts engineered to express vascular endothelial growth factor (VEGF) constitutively resulted in hemangioma formation and the appearance of VEGF in the circulation. To investigate the potential for using allogeneic myoblasts and the effects of delivery of VEGF-expressing myoblasts to non-muscle sites, we have enclosed them in microcapsules that protect allogeneic cells from rejection, yet allow the secretion of proteins produced by the cells. Methods: Encapsulated mouse primary myoblasts that constitutively expressed murine VEGF164, or encapsulated negative control cells, were implanted either subcutaneously or intraperitoneally into mice. Results: Upon subcutaneous implantation, capsules containing VEGF-expressing myoblasts gave rise to large tissue masses at the implantation site that continued to grow and were composed primarily of endothelial and smooth muscle cells directly surrounding the capsules, and macrophages and capillaries further away from the capsules. Similarly, when injected intraperitoneally, VEGF-producing capsules caused significant localized inflammation and angiogenesis within the peritoneum, and ultimately led to fatal intraperitoneal hemorrhage. Notably, however, VEGF was not detected in the plasma of any mice. Conclusions: We conclude that encapsulated primary myoblasts persist and continue to secrete VEGF subcutaneously and intraperitoneally, but that the heparin-binding isoform VEGF164 exerts localized effects at the site of production. VEGF secreted from the capsules attracts endothelial and smooth muscle cells in a macrophage-independent manner. These results, along with our previous results, show that the mode and site of delivery of the same factor by the same engineered myoblasts can lead to markedly different outcomes. Moreover, the results confirm that constitutive delivery of high levels of VEGF is not desirable. In contrast, regulatable expression may lead to efficacious, safe, and localized VEGF delivery by encapsulated allogeneic primary myoblasts that can serve as universal donors.
AB - Background: We previously demonstrated that intramuscular implantation of primary myoblasts engineered to express vascular endothelial growth factor (VEGF) constitutively resulted in hemangioma formation and the appearance of VEGF in the circulation. To investigate the potential for using allogeneic myoblasts and the effects of delivery of VEGF-expressing myoblasts to non-muscle sites, we have enclosed them in microcapsules that protect allogeneic cells from rejection, yet allow the secretion of proteins produced by the cells. Methods: Encapsulated mouse primary myoblasts that constitutively expressed murine VEGF164, or encapsulated negative control cells, were implanted either subcutaneously or intraperitoneally into mice. Results: Upon subcutaneous implantation, capsules containing VEGF-expressing myoblasts gave rise to large tissue masses at the implantation site that continued to grow and were composed primarily of endothelial and smooth muscle cells directly surrounding the capsules, and macrophages and capillaries further away from the capsules. Similarly, when injected intraperitoneally, VEGF-producing capsules caused significant localized inflammation and angiogenesis within the peritoneum, and ultimately led to fatal intraperitoneal hemorrhage. Notably, however, VEGF was not detected in the plasma of any mice. Conclusions: We conclude that encapsulated primary myoblasts persist and continue to secrete VEGF subcutaneously and intraperitoneally, but that the heparin-binding isoform VEGF164 exerts localized effects at the site of production. VEGF secreted from the capsules attracts endothelial and smooth muscle cells in a macrophage-independent manner. These results, along with our previous results, show that the mode and site of delivery of the same factor by the same engineered myoblasts can lead to markedly different outcomes. Moreover, the results confirm that constitutive delivery of high levels of VEGF is not desirable. In contrast, regulatable expression may lead to efficacious, safe, and localized VEGF delivery by encapsulated allogeneic primary myoblasts that can serve as universal donors.
KW - Angiogenesis
KW - Encapsulation
KW - Gene therapy
KW - Myoblasts
KW - VEGF
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U2 - 10.1002/1521-2254(200007/08)2:4<279::aid-jgm114>3.0.co;2-8
DO - 10.1002/1521-2254(200007/08)2:4<279::aid-jgm114>3.0.co;2-8
M3 - Article
C2 - 10953919
AN - SCOPUS:0034218552
VL - 2
SP - 279
EP - 288
JO - Journal of Gene Medicine
JF - Journal of Gene Medicine
SN - 1099-498X
IS - 4
ER -