title: Characterization of cellular senescence mechanisms in human corneal endothelial cells.
abstract: The human cornea is a tri-laminar structure composed of several cell types with substantial mitotic potential. Age-related changes in the cornea are associated with declining visual acuity and the onset of overt age-related corneal diseases. Corneal transplantation is commonly used to restore vision in patients with damaged or diseased corneas. However, the supply of donor tissue is limited, and thus there is considerable interest in the development of tissue-engineered alternatives. A major obstacle to these approaches is the short replicative lifespan of primary human corneal endothelial cells (HCEC). Accordingly, a comprehensive investigation of the signalling pathways and mechanisms underpinning proliferative lifespan and senescence in HCEC was undertaken. The effects of exogenous human telomerase reverse transcriptase expression, p53 knockdown, disruption of the pRb pathway by over-expression of CDK4 and reduced oxygen concentration on the lifespan of primary HCEC were evaluated. We provide proof-of-principle that forced expression of telomerase, when combined with either p53 knockdown or CDK4 over-expression, is sufficient to produce immortalized HCEC lines. The resultant cell lines express an HCEC-specific transcriptional fingerprint, and retain expression of the corneal endothelial temperature-sensitive potassium channel, suggesting that significant dedifferentiation does not occur as a result of these modes of immortalization. Exploiting these insights into proliferative lifespan barriers in HCEC will underpin the development of novel strategies for cell-based therapies in the human cornea.
authors: School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, UK.
authors: Angela N
authors: AN
authors: Sheerin
authors: S Kaye
authors: SK
authors: Smith
authors: Katrin
authors: K
authors: Jennert-Burston
authors: Amy J
authors: AJ
authors: Brook
authors: Marcus C
authors: MC
authors: Allen
authors: Badr
authors: B
authors: Ibrahim
authors: Dawn
authors: D
authors: Jones
authors: Corrin
authors: C
authors: Wallis
authors: Katrin
authors: K
authors: Engelmann
authors: William
authors: W
authors: Rhys-Williams
authors: Richard G A
authors: RG
authors: Faragher
authors: David
authors: D
authors: Kipling
mesh_terms: D002478:Cells, Cultured; D016922:Cellular Senescence; D051358:Cyclin-Dependent Kinase 4 / Q000378:metabolism; D042783:Endothelial Cells / Q000378:metabolism*; D004728:Endothelium, Corneal / Q000378:metabolism*; D006801:Humans; D018384:Oxidative Stress; D059467:Transcriptome; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
chemical_list: C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; C495900:CDK4 protein, human; D051358:Cyclin-Dependent Kinase 4