title: ES micro-environment enhances stemness and inhibits apoptosis in human limbal stem cells via the maintenance of telomerase activity.
abstract: Our previous work had found that telomerase rejuvenated in the cytoplasm of corneal epithelial cells cultured in embryonic stem cell-conditioned medium, the functional properties of stem-like corneal epithelial cells can be enhanced by co-culturing with embryonic stem cells (ESCs) via activation of the integrinβ1-FAK-PI3K/Akt signaling pathway. The goal of this study was to explore the potential molecular mechanisms of the ES micro-environment that enhance the stem cell-like phenotype and inhibit apoptosis in human limbal stem cells (LSC). The LSC were cultured in different media, either CnT-20 medium or CnT-20 +20% ES culture supernatant (ESC-CM). We observed that LSC cultured in ESC-CM had an increased proliferative capacity, greater serial passage capacity, higher colony-forming efficiency (CFE) and higher levels of stem cell-associated marker than those cultured in CnT-20. Compared with CnT-20, ESC-CM enhanced the undifferentiated status and inhibited apoptosis in the LSC by promoting the maintenance of telomerase activity, which could reduce the generation of reactive oxygen species (ROS), maintain the membrane potential (Δψm) at higher levels and reduce the expression of the p21 protein. Our findings indicated that ESC-CM system induced LSC to maintain a stem cell phenotype and inhibit the process of apoptosis. These effects might partially be achieved via the telomerase-p21-mitochondrial axis and the activation of the FAK/Wnt signaling pathways. This study may have high impact and clinic implication on the expansion of LSC in regenerative medicine, especially for ocular surface reconstruction.
authors: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong, China.
authors: Zhiping
authors: Z
authors: Liu
authors: Pengxia
authors: P
authors: Wan
authors: Hucheng
authors: H
authors: Duan
authors: Jin
authors: J
authors: Zhou
authors: Bowei
authors: B
authors: Tan
authors: Ying
authors: Y
authors: Liu
authors: Qiang
authors: Q
authors: Zhou
authors: Chenjing
authors: C
authors: Zhou
authors: Zheqian
authors: Z
authors: Huang
authors: Bishan
authors: B
authors: Tian
authors: Chaoyang
authors: C
authors: Li
authors: Zhichong
authors: Z
authors: Wang
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D060833:Cellular Microenvironment / Q000187:drug effects; D003114:Colony-Forming Units Assay; D017077:Culture Media, Conditioned / Q000494:pharmacology; D053595:Embryonic Stem Cells / Q000166:cytology* / Q000201:enzymology*; D051416:Focal Adhesion Protein-Tyrosine Kinases / Q000378:metabolism; D006801:Humans; D016850:Limbus Corneae / Q000166:cytology*; D051379:Mice; D008954:Models, Biological; D034622:RNA Interference / Q000187:drug effects; D019098:Telomerase / Q000378:metabolism*; D060449:Wnt Signaling Pathway / Q000187:drug effects
chemical_list: D017077:Culture Media, Conditioned; D051416:Focal Adhesion Protein-Tyrosine Kinases; D019098:Telomerase