title: PEDF promotes self-renewal of limbal stem cell and accelerates corneal epithelial wound healing.
abstract: Limbal epithelial stem cell (LSC) transplantation is a prevalent therapeutic method for patients with LSC deficiency. The maintenance of stem cell characteristics in the process of culture expansion is critical for the success of ocular surface reconstruction. Pigment epithelial-derived factor (PEDF) increased the numbers of holoclone in LSC monolayer culture and preserved the stemness of LSC in suspension culture by evidence of ΔNp63α, Bmi-1, and ABCG2 expression. BrdU pulse-labeling assay also demonstrated that PEDF stimulated LSCs proliferation. In air-lift culture of limbal equivalent, PEDF was capable of increasing the numbers of ΔNp63α-positive cells. The mitogenic effect of PEDF was found to be mediated by the phosphorylations of p38 MAPK and STAT3 in LSCs. Synthetic 44-mer PEDF (residues 78-121) was as effective as the full length PEDF in LSC expansion in suspension culture and limbal equivalent formation, as well as the activation of p38 MAPK and STAT3. In mice subjecting to mechanical removal of cornea epithelium, 44-mer PEDF facilitated corneal wound healing. Microscopically, 44-mer PEDF advanced the early proliferative response in limbus, increased the proliferation of ΔNp63α-positive cells both in limbus and in epithelial healing front, and assisted the repopulation of limbus in the late phase of wound healing. In conclusion, the capability of expanding LSC in cell culture and in animal indicates the potential of PEDF and its fragment (e.g., 44-mer PEDF) in ameliorating limbal stem cell deficiency; and their uses as therapeutics for treating corneal wound.
authors.affiliation: Department of Medical Research, Mackay Memorial Hospital Taipei, Taiwan, Republic of China.
authors.forename: Tsung-Chuan
authors.initials: TC
authors.lastname: Ho
authors.forename: Show-Li
authors.initials: SL
authors.lastname: Chen
authors.forename: Ju-Yun
authors.initials: JY
authors.lastname: Wu
authors.forename: Mei-Ying
authors.initials: MY
authors.lastname: Ho
authors.forename: Lee-Jen
authors.initials: LJ
authors.lastname: Chen
authors.forename: Jui-Wen
authors.initials: JW
authors.lastname: Hsieh
authors.forename: Huey-Chuan
authors.initials: HC
authors.lastname: Cheng
authors.forename: Yeou-Ping
authors.initials: YP
authors.lastname: Tsao
mesh_terms: D000818:Animals; D001973:Bromodeoxyuridine / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D019573:Epithelium, Corneal / Q000187:drug effects / Q000473:pathology*; D005136:Eye Proteins / Q000494:pharmacology*; D005455:Fluorescent Antibody Technique; D006801:Humans; D016850:Limbus Corneae / Q000166:cytology*; D051379:Mice; D008934:Mitogens / Q000494:pharmacology; D041681:NIH 3T3 Cells; D009414:Nerve Growth Factors / Q000494:pharmacology*; D010455:Peptides / Q000494:pharmacology; D011817:Rabbits; D050796:STAT3 Transcription Factor / Q000378:metabolism; D015843:Serpins / Q000494:pharmacology*; D013234:Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology; D014945:Wound Healing / Q000187:drug effects*; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism; D000099174:Pigment Epithelium-Derived Factor
chemical_list: D001973:Bromodeoxyuridine; D005136:Eye Proteins; D008934:Mitogens; D009414:Nerve Growth Factors; D010455:Peptides; D050796:STAT3 Transcription Factor; D015843:Serpins; D048051:p38 Mitogen-Activated Protein Kinases; D000099174:Pigment Epithelium-Derived Factor
keywords: Cornea; Limbal stem cells; Peptide; Pigment epithelial-derived factor; Regenerative medicine; Wound healing