title: Decreased VEGF-A and sustained PEDF expression in a human retinal pigment epithelium cell line cultured under hypothermia.
abstract: BACKGROUND
  Previous reports have described a decrease in retinal temperature and clinical improvement of wet age-related macular degeneration (AMD) after vitrectomy. We hypothesized that the retinal temperature decrease after vitrectomy plays a part in the suppression of wet AMD development. To test this hypothesis, we evaluated the temperature dependence of the expression of vascular endothelial growth factor-A (VEGF-A) and in vitro angiogenesis in retinal pigment epithelium (RPE).
  
  
  RESULTS
  We cultured ARPE-19 cells at 37, 35, 33 and 31 °C and measured the expression of VEGF-A, VEGF-A splicing variants, and pigment epithelium-derived factor (PEDF). We performed an in vitro tube formation assay. The dehydrogenase activity was also evaluated at each temperature. Expression of VEGF-A significantly decreased with decreased temperature while PEDF expression did not. VEGF165 expression and in vitro angiogenesis also were temperature dependent. The dehydrogenase activity significantly decreased as the culture temperature decreased.
  
  
  CONCLUSIONS
  RPE cultured under hypothermia that decreased cellular metabolism also had decreased VEGF-A and sustained PEDF expression, creating an anti-angiogenic environment. This mechanism may be associated with a beneficial effect after vitrectomy in patients with wet AMD.
authors.affiliation: Department of Ophthalmology, Aichi Medical University, Nagakute, 480-1195, Aichi, Japan. mtakeyam@aichi-med-u.ac.jp.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Takeyama
authors.affiliation: Department of Biochemistry and Molecular Biology, School of Nursing and Health, Aichi Prefectural University, Nagoya, 463-8502, Aichi, Japan. yoneda@nrs.aichi-pu.ac.jp.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Yoneda
authors.affiliation: Department of Clinical Trial and Clinical Epidemiology, Faculty of Medicine, University of Tsukuba, Tsukuba, 305-8575, Ibaraki, Japan. mgosho@md.tsukuba.ac.jp.
authors.forename: Masahiko
authors.initials: M
authors.lastname: Gosho
authors.affiliation: Department of Ophthalmology, Aichi Medical University, Nagakute, 480-1195, Aichi, Japan. iwaki@aichi-med-u.ac.jp.
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Iwaki
authors.affiliation: Department of Ophthalmology, Aichi Medical University, Nagakute, 480-1195, Aichi, Japan. zako@aichi-med-u.ac.jp.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Zako
mesh_terms: D002460:Cell Line; D005136:Eye Proteins / Q000378:metabolism*; D006801:Humans; D007035:Hypothermia; D018919:Neovascularization, Physiologic; D009414:Nerve Growth Factors / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D055213:Retinal Pigment Epithelium / Q000378:metabolism*; D015843:Serpins / Q000378:metabolism*; D013997:Time Factors; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*; D000099174:Pigment Epithelium-Derived Factor
chemical_list: D005136:Eye Proteins; D009414:Nerve Growth Factors; D012333:RNA, Messenger; D015843:Serpins; D042461:Vascular Endothelial Growth Factor A; D000099174:Pigment Epithelium-Derived Factor; C467484:VEGFA protein, human