Article

Angiogenesis potential of human limbal stromal niche cells.

Department of Ophthalmology, Tongji Hospital, Wuhan, People's Republic of China.
Investigative ophthalmology & visual science (impact factor: 3.43). 04/2012; 53(7):3357-67. DOI:10.1167/iovs.11-9414 pp.3357-67
Source: PubMed

ABSTRACT The perivascular localization of stem cell (SC) niches suggests the presence of a vascular niche. We aimed to determine the angiogenesis potential of limbal niche cells (NCs).
Human limbal NCs were isolated and serially passaged on plastic or coated Matrigel in embryonic SC medium containing BFGF and leukemia inhibitory factor before being reseeded in 3D Matrigel. Expression of angiogenesis markers was assessed by RT-qPCR and immunofluorescence staining. Their angiogenesis potential was measured by differentiation into vascular endothelial cells and by supporting vascular tube network formed by human umbilical vein endothelial cells (HUVEC) on Matrigel. Their support of limbal epithelial progenitor cells (LEPC) was examined in sphere growth formed by reunion in 3D Matrigel.
On plastic, limbal NC could be cultured only up to four passages before turning into myofibroblasts. In contrast, on coated Matrigel, they could be expanded for up to 12 passages with upregulation of markers suggestive of angiogenesis progenitors when reseeded in 3D Matrigel because they could differentiate into vascular endothelial cells and pericytes stabilizing the tube network formed by HUVEC. Although both expanded limbal NCs and HUVEC rejoined with LEPC to form spheres to upregulate expression of ΔNp63α, CK15, and CEBPδ, the former but not the latter abolished expression of CK12 keratin.
Human limbal NCs continuously expanded on the basement membrane differentiate into angiogenesis progenitors that prevent differentiation of LEPC/SCs. They may partake in formation of the vascular niche and contribute to angiogenesis during wound healing.

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Keywords

12 passages
 
3D Matrigel
 
abolished expression
 
basement membrane differentiate
 
embryonic SC medium
 
form spheres
 
Human limbal NCs
 
human umbilical vein endothelial cells
 
limbal epithelial progenitor cells
 
limbal niche cells
 
perivascular localization
 
prevent differentiation
 
serially passaged
 
sphere growth
 
tube network
 
upregulate expression
 
vascular endothelial cells
 
vascular niche
 
vascular tube network
 
wound healing