title: Overexpression of SIRT1 promotes high glucose-attenuated corneal epithelial wound healing via p53 regulation of the IGFBP3/IGF-1R/AKT pathway.
abstract: OBJECTIVE
  To investigate how Sirtuin (silent mating type information regulation 2 homolog) 1 (SIRT1) promotes high glucose-attenuated corneal epithelial wound healing.
  
  
  METHODS
  The effects of high glucose on SIRT1 expression were assessed in primary human corneal epithelial cells (CECs) in treatment of 5 mM d-glucose (normal glucose [NG]) and 25 mM D-glucose (high glucose [HG]) and corneas from Ins2(Akita/+) mice by Western blotting. The osmotic pressure of the NG medium was adjusted to that of the HG medium by adding 20 mM mannitol. Pifithrin-α (PFT-α) was used to inhibit the expression of p53 and an adenovirus was used for overexpression of SIRT1 in vivo and in vitro. How overexpression of SIRT1 promotes HG-attenuated corneal epithelial wound healing via p53 regulation of the IGFBP3 (insulin-like growth factor binding protein-3)/IGF-1 (insulin-like growth factor-1)/AKT pathway was investigated in CECs and Ins2(Akita/+) mice.
  
  
  RESULTS
  HG induced the downregulation of SIRT1 and the upregulation of p53 acetylation in primary human CECs and corneas from Ins2(Akita/+) mice. The results of cell migration assay and corneal wound healing from Ins2(Akita/+) mice demonstrated that SIRT1 overexpression strongly promoted wound healing in the presence of HG levels via the downregulation of the IGFBP3 protein. The levels of total p53 expression and acetylated p53 decreased dramatically in the presence of PFT-α, whereas the IGF-1R/AKT pathway was activated in CECs. The results of cell migration assay suggested this posttranslational modification of p53 was involved in the response to cell injury under HG conditions in CECs.
  
  
  CONCLUSIONS
  The molecular mechanism by which SIRT1 promotes corneal epithelial wound healing was involved in an enhancement of the IGFBP3/IGF-1/AKT pathway through the deacetylation of p53. This study also suggests that SIRT1 has a protective role in the pathogenesis of diabetic keratopathy.
authors: State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong Academy of Medical Sciences, Qingdao, China.
authors: Ye
authors: Y
authors: Wang
authors: Xiaowen
authors: X
authors: Zhao
authors: Daling
authors: D
authors: Shi
authors: Peng
authors: P
authors: Chen
authors: Yang
authors: Y
authors: Yu
authors: Lingling
authors: L
authors: Yang
authors: Lixin
authors: L
authors: Xie
mesh_terms: D000818:Animals; D052160:Benzothiazoles / Q000494:pharmacology; D015153:Blotting, Western; D002478:Cells, Cultured; D015536:Down-Regulation; D019573:Epithelium, Corneal / Q000187:drug effects* / Q000378:metabolism; D005786:Gene Expression Regulation / Q000502:physiology*; D005947:Glucose / Q000494:pharmacology*; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018613:Microscopy, Confocal; D011494:Protein Kinases / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D017526:Receptor, IGF Type 1 / Q000378:metabolism; D056564:Sirtuin 1 / Q000235:genetics*; D014050:Toluene / Q000031:analogs & derivatives / Q000494:pharmacology; D016159:Tumor Suppressor Protein p53 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D014945:Wound Healing / Q000187:drug effects*
chemical_list: D052160:Benzothiazoles; C515497:IGFBP3 protein, human; D018972:Insulin-Like Growth Factor Binding Protein 3; D016159:Tumor Suppressor Protein p53; D014050:Toluene; C121565:pifithrin; D011494:Protein Kinases; D017526:Receptor, IGF Type 1; D051057:Proto-Oncogene Proteins c-akt; C447939:SIRT1 protein, human; D056564:Sirtuin 1; D005947:Glucose
keywords: SIRT1; corneal wound healing; diabetic keratopathy