title: Transcription of Inflammatory Cytokine TNFα is Upregulated in Retinal Angiogenesis under Hyperoxia.
abstract: OBJECTIVE
  Hypoxia induces angiogenesis while hyperoxia promotes vasoregression in the retina. We investigated herein the effect of prolonged hyperoxia on retinal angiogenesis and the underlying mechanism in an oxygen-induced retinopathy (OIR) model.
  
  
  METHODS
  Vascular morphology was quantified in whole-mount retina from the mice subjected to the conventional OIR model (c-OIR) or the OIR model with prolonged hyperoxia (p-OIR). Expressions of genes related to angiogenesis were determined by real-time PCR.
  
  
  RESULTS
  p-OIR retinas showed few intraretinal neovascular tufts at the border of avascular zones, lacking preretinal neovascularization, whereas c-OIR retinas had numerous preretinal neovascularizations. p-OIR retinas demonstrated outgrowth of capillaries in the deep layers despite persistent hyperoxia and possess a larger avascular zone compared with the c-OIR retinas. The capillaries in the p-OIR retinas were well-formed in contrast to those in the c-OIR retinas. p-OIR retinas expressed significantly higher TNFα (∼4 fold) than c-OIR retinas. The expression of vascular endothelial growth factor, Erythropoietin, Angiopoietin 1 and 2 remained unchanged.
  
  
  CONCLUSIONS
  Our data demonstrate that TNFα transcription is increased in hyperoxia-promoted retinal angiogenesis, implicating it, in association with low VEGF levels, as a possible proponent in retinal angiogenesis under hyperoxia.
authors.affiliation: 5th Medical Clinic, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.
authors.forename: Yuxi
authors.initials: Y
authors.lastname: Feng
authors.forename: Shalini
authors.initials: S
authors.lastname: Gross
authors.forename: Anupriya
authors.initials: A
authors.lastname: Chatterjee
authors.forename: Yumei
authors.initials: Y
authors.lastname: Wang
authors.forename: Jihong
authors.initials: J
authors.lastname: Lin
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Hammes
mesh_terms: D042683:Angiopoietin-1 / Q000235:genetics / Q000378:metabolism; D042702:Angiopoietin-2 / Q000235:genetics / Q000378:metabolism; D000818:Animals; D004921:Erythropoietin / Q000235:genetics / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D005786:Gene Expression Regulation; D018496:Hyperoxia; D000860:Hypoxia; D008810:Mice, Inbred C57BL; D015861:Retinal Neovascularization / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics* / Q000378:metabolism; D015854:Up-Regulation; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism
chemical_list: D042683:Angiopoietin-1; D042702:Angiopoietin-2; D014409:Tumor Necrosis Factor-alpha; D042461:Vascular Endothelial Growth Factor A; D004921:Erythropoietin