In:
Journal of Cellular Physiology, Wiley, Vol. 227, No. 5 ( 2012-05), p. 2030-2039
Abstract:
Transplantation of cultivated human limbo‐corneal epithelial (HLE) cells has been recognized as an effective stem cell (SC) therapy for treating corneal epithelial SC deficiency caused by burn or other diseases. With this technique, cryo‐preserved human intact amniotic membrane (IAM) has been successfully used as a cell culture substrate and carrier, and is reported to preferentially preserve HLE stem/progenitor cells in vitro. However, little is known about what factors released by HLE cells are involved in the progenitor cell‐preserving mechanism. Using proteomic method, we identified 13 proteins over‐expressed by HLE cells cultured on IAM, which included heat shock protein 70‐1 (Hsp70‐1), Hsp‐27, glutathione (GSH) S‐transferase, annexin A2, galectin‐7, and protein S100‐A9. Increased Hsp70‐1 expression was confirmed by Western blot and real‐time PCR. The role of Hsp70‐1 in promoting HLE cell survival was demonstrated by increased apoptosis index and increased cleaved poly ADP‐ribose polymerase (CPARP) formation in hsp70‐1 ‐silenced, but not normal HLE cells after exposure to sublethal UVB irradiation or hydrogen peroxide. To understand the regulatory mechanism of Hsp70‐1 expression in HLE cells, the role of transcription factor deltaNp63 (a well‐recognized HLE stem cell; SC marker) was studied. We found that over‐expression of deltaNp63α by plasmid vector induced a corresponding increase in Hsp70‐1 protein production. Likewise, Hsp70‐1 expression decreased in HLE cells after addition of deltaNp63α SiRNA. Immunoconfocal microscopy also revealed a paralleled expression of both proteins in corneal specimens. Thus, deltaNp63α‐associated Hsp70‐1 over‐expression may promote HLE progenitor cell survival on IAM, possibly through the cytoprotective and anti‐apoptotic effect of Hsp70‐1. J. Cell. Physiol. 227: 2030–2039, 2012. © 2011 Wiley Periodicals, Inc.
Type of Medium:
Online Resource
ISSN:
0021-9541
,
1097-4652
Language:
English
Publisher:
Wiley
Publication Date:
2012
detail.hit.zdb_id:
1478143-8
SSG:
12
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