PURPOSE: 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). METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.
PURPOSE: 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). METHODS: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. RESULTS: 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. CONCLUSIONS: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.
Authors: Edgar M Espana; Andre C Romano; Tetsuya Kawakita; Mario Di Pascuale; Robert Smiddy; Scheffer C G Tseng Journal: Invest Ophthalmol Vis Sci Date: 2003-10 Impact factor: 4.799
Authors: Scott T Avecilla; Koichi Hattori; Beate Heissig; Rafael Tejada; Fang Liao; Koji Shido; David K Jin; Sergio Dias; Fan Zhang; Travis E Hartman; Neil R Hackett; Ronald G Crystal; Larry Witte; Daniel J Hicklin; Peter Bohlen; Dan Eaton; David Lyden; Fredric de Sauvage; Shahin Rafii Journal: Nat Med Date: 2003-12-21 Impact factor: 53.440
Authors: Szu-Yu Chen; Megha Mahabole; Elan Horesh; Sara Wester; Jeffrey L Goldberg; Scheffer C G Tseng Journal: Invest Ophthalmol Vis Sci Date: 2014-07-03 Impact factor: 4.799