Human limbal niche cells are a powerful regenerative source for the prevention of limbal stem cell deficiency in a rabbit model

Abstract

In this article, human limbal niche cells (LNC) or bone marrow derived mesenchymal stem cells (BMMSC) were used to prevent limbal stem cell deficiency (LSCD) in an alkali burn rabbit model and their results were compared. The epithelial cell defect area, corneal neovascularization, and the print cell cytometry were quantified to grade the severity of LSCD. Three months after the alkali burn, a partial LSCD was observed in the control group (no treatment) indicated by chronic corneal epithelial defects, positive corneal fluorescein staining, neovascularization and goblet cell migration. In contrast, the severity of LSCD in both the LNC and BMMSC transplantation groups was dramatically reduced as shown by smaller epithelial cell defects, decreased fluorescein sodium staining, decreased neovascularization and decreased goblet cell density. Interestingly, the LNC group was shown to more effectively prevent LSCD than the BMMSC group. Further analysis indicated subconjunctivally transplanted LNCs were more powerful than BMMSCs to prevent LSCD, at least partially, due to increased activation of SCF-c-Kit signal. We conclude that LNCs are a more powerful resource than BMMSCs to prevent LSCD in an alkali burn rabbit model, at least partially due to increased activation of SCF signaling.

Differential Gene Expression between Limbal Niche Progenitors and Bone Marrow Derived Mesenchymal Stem Cells

“…In this study, Genechip was used to compare gene expression profiles between human LNCs and BMMSCs and RT-qPCR was used to verify the Genechip results. Both Genechip and RT-qPCR results showed that the expression of CD73, CD90, CD105, PDGFRβ, Vimentin, SCF and KIT in LNC were higher than that from BMMSC, consistent with our previous reports [2,17].…”

“…Previously, we have shown LNC can maintain the stemness of LEPCs better than BMMSC when co-cultured in 3D Matrigel, both of which could form spheres after ten days of culture, although LEPC co-cultured with LNC expressed higher level of p63α but lower level of CK12 [1,2]. Animal experiments verified these observations wherein both subconjunctivally injected LNCs and BMMSCs prevented LSCD caused by alkali burn, yet LNC treated corneas had less corneal opacity and faster epithelial healing [17]. Although these results suggest LNC are therapeutically more advantageous than BMMSC for LSCD, the mechanism remains unclear.…”

“…It has been recognized that these two kinds of cells have many similarities, both of them express CD73, CD90 and CD105 [2,8,18], can be induced into corneal epithelial like-cells [5,9,10,15], and can prevent LSCD after corneal alkali burn in rats or rabbits when subconjunctivally injected. However, we have reported that LNCs can support LSC better than BMMSC under 3D Matrigel culture environment in vitro [1,2], and LNCs prevent LSCD caused by alkali burn better than BMMSCs [17]. Therefore, exploring the differences between LNC and BMMSC may reveal the key factors for the reconstruction of the LSC niche in vivo.…”

KIT ligand produced by limbal niche cells under control of SOX10 maintains limbal epithelial stem cell survival by activating the KIT/AKT signalling pathway

“…that they play important roles in regulating LESCs survival and development. 22,38,[41][42][43][44][45][46] In addition, as shown above, LNCs act in a paracrine fashion to support LESCs in vitro, and so, we decided to analyse whether SOX10 acts through growth factors to influence the survival of LESCs in LNCs. To identify which factors might be involved, we compared the expression of a series of growth factor genes in si-Sox10 transfected LNCs vs si-C or mock-transfected LNCs.…”

“…[13][14][15][16][17][18][19][20][21] Previous results have shown that LNCs support self-renewal of LESCs, 21 and LNCs transplants prevent LSCD in an alkali burn rabbit model. 22 They likely do this by secreting paracrine factors including KITL, 22 but the detailed mechanisms of KITL regulation in LNCs and how KIT, KITL and its downstream signal pathways are involved are not clearly understood. Here, we use both in vivo and in vitro approaches to provide insights into the regulation of KITL in LNCs and its action in LESCs.…”