title: Expression of Sirt1 and Sirt2 in injured optic retina of calorie restricted rats.
abstract: OBJECTIVE
  To investigate retinal ganglion cell (RGC) survival after optic nerve injury in calorie-restricted (CR) rats, and analyze the potential role of Sirtuins.
  
  
  METHODS
  Ten-month old male Sprague-Dawley rats (n=14) were divided into calorie restricted (CR) and ad libitum (AL) groups. In the CR group (n=7), the rats were denied access to food every other day. Animals in the AL group (n=7) had had free access to food. PN-ON grafting was carried out on the right eyes of all subjects after 5 months of feeding. Three weeks postoperatively, retina samples were collected, half of which were fixed in 4% paraformaldehyde (PFA) and subjected to standard immunofluorescence staining for TUJ-1. The remaining samples were subjected to total RNA analysis and RT-PCR for Sirt1 and 2 expression.
  
  
  RESULTS
  Comparing the amount of TUJ-1 staining between the groups, the mean density and the total number of RGCs showed no significant difference. RT-PCR results indicated that mRNA expression of Sirtuin2 in the CR group was significantly lower than that in the AL group, whereas no statistically-significant difference was observed between  the two groups regarding the mRNA expression of Sirt1.
  
  
  CONCLUSIONS
  Calorie restriction had no impact on the survival of injured RGCs. The down-regulated mRNA expression of Sirt2 in the CR group may indicate an improved capacity for regeneration among these animals,  but more work is needed to explore this possibility.
authors.affiliation: Chinese Universtiy of Hong Kong Joint Shantou International Eye Center, Shantou, China. yqgeng@126.com
authors.forename: Yiqun
authors.initials: Y
authors.lastname: Geng
authors.forename: Jingying
authors.initials: J
authors.lastname: Wang
authors.forename: Jiajian
authors.initials: J
authors.lastname: Liang
authors.forename: Ciyan
authors.initials: C
authors.lastname: Xu
authors.forename: Ye
authors.initials: Y
authors.lastname: Zhi
mesh_terms: D000818:Animals; D031204:Caloric Restriction; D002470:Cell Survival / Q000502:physiology; D015536:Down-Regulation; D008297:Male; D020221:Optic Nerve Injuries / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012160:Retina / Q000293:injuries / Q000378:metabolism*; D012165:Retinal Ganglion Cells / Q000502:physiology*; D056564:Sirtuin 1 / Q000235:genetics / Q000378:metabolism*; D056565:Sirtuin 2 / Q000235:genetics / Q000378:metabolism*
chemical_list: D012333:RNA, Messenger; C097475:Sirt2 protein, rat; C488368:Sirt1 protein, rat; D056564:Sirtuin 1; D056565:Sirtuin 2