Author + information
Previously, we have shown that microencapsulated allogeneic mesenchymal stem cells (MSCs) improve angiogenesis and arteriogenesis compared to non–encapsulated MSCs in a rabbit model of peripheral arterial disease1. Whether this improvement is related to enhanced cell survival due to immunoprotection or enhanced ability of the MSCs to release pro–angiogenic cytokines in response to hypoxia is not clear. The objective of the in vitro current study was to evaluate the response to hypoxia of microencapsulated and non–encapsulated human MSCs (hMSCs).
Early passage hMSCs were microencapsulated in a 2% alginate solution or perfiuorocarbon–modified alginate (PFOB) containing 106 hMSCs/ml alginate. Encapsulated and non–encapsulated MSCs were subjected to 1% oxygen conditions for 4 hours and compared to controls in normoxic conditions (5% CO2). Alginate and PFOB capsules were lysed with citric acid and Versene and proteins were isolated. Western immunoblots were probed with anti–human hypoxia inducible factor–1α (HIF–1α) monoclonal antibody.
Immunoblot analysis of cell lysates revealed increased level of HIF–1α expression in all experimental arms cultured in hypoxia as compared to control, with a trend towards less HIF–1α in encapsulated cells relative to cancer or naked cells (P<0.07). PFOB encapsulated hMSCs demonstrated production of a small amount of HIF–1α when cultured in normoxia (0.09±0.06) and hypoxia (0.02±0.01).
MSCs showed evidence of less hypoxic protein upregulation when they are encapsulated, suggesting that encapsulation may be the most beneficial for angiogenic recruitment in PAD therapy.
(1) Kedziorek et al. Stem Cells, 2012.
Poster Sessions, Expo North
Sunday, March 10, 2013, 3:45 p.m.–4:30 p.m.
Session Title: Cell Therapy and Angiogenesis
Abstract Category: 42. TCT@ACC–i2: Cell Therapy & Angiogenesis
Presentation Number: 2110–235
- 2013 American College of Cardiology Foundation