title: Senescence Mediated by p16INK4aImpedes Reprogramming of Human Corneal Endothelial Cells into Neural Crest Progenitors.
abstract: Human corneal endothelial cells (HCECs) have limited proliferative capacity due to "contact-inhibition" at G1 phase. Such contact-inhibition can be delayed from Day 21 to Day 42 by switching EGF-containing SHEM to LIF/bFGF-containing MESCM through transient activation of LIF-JAK1-STAT3 signaling that delays eventual nuclear translocation of p16INK4a. Using the latter system, we have reported a novel tissue engineering technique by implementing 5 weekly knockdowns with p120 catenin (p120) and Kaiso siRNAs since Day 7 to achieve effective expansion of HCEC monolayers to a transplantable size with a normal HCEC density, through reprogramming of HCECs into neural crest progenitors by activating p120-Kaiso-RhoA-ROCK-canonical BMP signaling. Herein, we noted that a single knockdown with p120-Kaiso siRNAs at Day 42 failed to achieve such reprogramming when contact inhibition transitioned to senescence with nuclear translocation of p16INK4a. In contrast, 5 weekly knockdowns with p120-Kaiso siRNAs since Day 7 precluded senescence mediated by p16INK4aby inducing nuclear translocation of Bmi1 because of sustained activation of JAK2-STAT3 signaling downstream of p120-Kaiso-RhoA-ROCK signaling. STAT3 or Bmi1 siRNA impeded nuclear exclusion of p16INK4aand suppressed the reprogramming induced by p120-Kaiso siRNAs, suggesting that another important engineering strategy of HCEC lies in prevention of senescence mediated by nuclear translocation of p16INK4a.
authors.affiliation: Department of Ophthalmology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Wen-Juan
authors.initials: WJ
authors.lastname: Lu
authors.affiliation: R&D Department, Tissue Tech, Inc., Ocular Surface Research &amp;Education Foundation, Miami, FL, USA.|Ocular Surface Center, Ocular Surface Research &Education Foundation, Miami, FL, USA.
authors.forename: Scheffer C G
authors.initials: SC
authors.lastname: Tseng
authors.affiliation: R&D Department, Tissue Tech, Inc., Ocular Surface Research &amp;Education Foundation, Miami, FL, USA.
authors.forename: Shuangling
authors.initials: S
authors.lastname: Chen
authors.affiliation: R&D Department, Tissue Tech, Inc., Ocular Surface Research &amp;Education Foundation, Miami, FL, USA.
authors.forename: Sean
authors.initials: S
authors.lastname: Tighe
authors.affiliation: Dalian Central Hospital, Dalian City, Liaoning Province, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Ophthalmology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Liu
authors.affiliation: R&D Department, Tissue Tech, Inc., Ocular Surface Research &amp;Education Foundation, Miami, FL, USA.
authors.forename: Szu-Yu
authors.initials: SY
authors.lastname: Chen
authors.affiliation: R&D Department, Tissue Tech, Inc., Ocular Surface Research &amp;Education Foundation, Miami, FL, USA.
authors.forename: Chen-Wei
authors.initials: CW
authors.lastname: Su
authors.affiliation: R&D Department, Tissue Tech, Inc., Ocular Surface Research &amp;Education Foundation, Miami, FL, USA.
authors.forename: Ying-Ting
authors.initials: YT
authors.lastname: Zhu
mesh_terms: D002478:Cells, Cultured; D065150:Cellular Reprogramming; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000378:metabolism*; D042783:Endothelial Cells / Q000502:physiology*; D005786:Gene Expression Regulation; D006801:Humans; D058953:Neural Stem Cells / Q000502:physiology*; D015398:Signal Transduction
chemical_list: C000614131:CDKN2A protein, human; D019941:Cyclin-Dependent Kinase Inhibitor p16