title: Ionising radiation triggers fat accumulation in white adipose tissue.
abstract: OBJECTIVE
  To investigate changes in gonadal white adipose tissue and lipogenesis-related gene expression induced by radiation exposure.
  
  
  METHODS
  Groups of two-month-old C57BL/6 mice were exposed whole-body to ¹³⁷Cs γ-rays at a single dose (5 gray [Gy]) or fractionated doses (1 Gy x 5 times, 0.5 Gy x 10 times, or 0.2 Gy x 25 times). Six months after irradiation, gonadal white adipose tissue was isolated from mice. Two and 25-month-old mice were used as young and old study references. Real-time reverse transcriptase-polymerase chain reaction (RT-PCR) was used to measure messenger RNA (mRNA) expression of genes related to: (i) Primary lipid metabolism (ATP-citrate lyase [ACL], malic enzyme1 [ME1] and glucose-6-phosphate dehydrogenase 2 [G6PD2]), (ii) glucose uptake (glucose transporter 4 [GLUT4]), (iii) fatty acid synthesis (sterol regulatory element binding transcription factor 1 [SREBP-1c], fatty acid synthetase [FAS] and acetyl-coenzyme A carboxylase beta [ACC]), (iv) triglyceride synthesis (diacylglycerol O-acyltransferase 1 [DGAT1] and diacylglycerol O-acyltransferase 2 [DGAT2]), and (v) adipose-derived hormones (leptin [LEP]).
  
  
  RESULTS
  The weight of gonadal white adipose tissue in the irradiated groups tended to increase compared to the non-irradiated group though the radiation-induced increase in white adipose tissue was only significant for the 5 x 1 Gy group. The mRNA levels of SREBP-1c, ACC, FAS, ACL, GLUT4, ME1 and G6PD2 were relatively lower in γ-irradiated groups than in non-irradiated groups. The mRNA levels of leptin and DGAT were relatively higher than non-irradiated groups. The changes in expression of these lipogenesis-related genes caused by γ-irradiation showed a very similar pattern to changes caused by ageing.
  
  
  CONCLUSIONS
  A physical agent such as γ-rays can trigger biological responses resulting in fat accumulation of gonadal white adipose tissue in mice.
authors.affiliation: Radiation Research Division for Biotechnology, Advanced Radiation Technology Institute (ARTI), Korea Atomic Energy Research Institute (KAERI), Jeongeup, Jeonbuk, Republic of Korea.
authors.forename: Sung Kee
authors.initials: SK
authors.lastname: Jo
authors.forename: Min-A
authors.initials: MA
authors.lastname: Seol
authors.forename: Hae-Ran
authors.initials: HR
authors.lastname: Park
authors.forename: Uhee
authors.initials: U
authors.lastname: Jung
authors.forename: Changhyun
authors.initials: C
authors.lastname: Roh
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism / Q000528:radiation effects; D052436:Adipose Tissue, White / Q000166:cytology* / Q000528:radiation effects*; D000818:Animals; D001823:Body Composition / Q000528:radiation effects; D002588:Cesium Radioisotopes / Q000494:pharmacology; D051048:Diacylglycerol O-Acyltransferase / Q000378:metabolism; D004307:Dose-Response Relationship, Radiation; D005260:Female; D005720:Gamma Rays; D020738:Leptin / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D012333:RNA, Messenger / Q000378:metabolism; D011839:Radiation, Ionizing; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D002588:Cesium Radioisotopes; D020738:Leptin; D012333:RNA, Messenger; C494881:DGAT1 protein, human; D051048:Diacylglycerol O-Acyltransferase