Gingival RAGE expression in calorie-restricted versus ad libitum-fed rats.
BACKGROUND
The receptor for advanced glycation end products (RAGE) is a multiligand receptor expressed in a number of cell types, including gingival epithelia. RAGE mediates inflammation and induces cellular oxidative stress. Upregulation of RAGE is associated with various diseases, such as periodontal and cardiovascular diseases. This study examines the hypothesis that the gingiva of rats fed a calorie-restriction (CR) diet expresses lower levels of RAGE than the gingiva of rats fed an ad libitum (AL) diet.


METHODS
Male F344BN rats (n = 16) from the National Institute on Aging (NIA) were fed a CR (n = 8) or AL (n = 8) diet according to NIA recommendations. Rats were sacrificed by guillotine at 8 (n = 5), 18 (n = 3), 29 (n = 4), and 38 (n = 4) months of age. The gingiva from around the molars was dissected and submitted for histologic and molecular analyses.


RESULTS
Immunohistochemistry revealed that RAGE was expressed in the plasma membrane and cytoplasm of gingival epithelial cells and endothelial cells from both groups. RAGE mRNA levels were quantified relative to levels of GAPDH mRNA by real-time reverse-transcriptase polymerase chain reaction. The mean relative RAGE mRNA level in the CR group (7.26 ± 0.54) was lower than in the AL group (10 ± 1.4) (P <0.05). There were no detectable differences in RAGE expression according to animal age.


CONCLUSIONS
Gingival RAGE expression in rats is reduced by calorie restriction.
Aris
John P
JP
Department of Anatomy and Cell Biology, College of Medicine, University of Florida, Gainesville, FL 32610-0414, USA.
Elios
Megan C
MC
Bimstein
Enrique
E
Wallet
Shanon M
SM
Cha
Seunghee
S
Lakshmyya
Kesavalu N
KN
Katz
Joseph
J
D000818:Animals; D031204:Caloric Restriction; D004847:Epithelial Cells / Q000378:metabolism; D015870:Gene Expression; D005881:Gingiva / Q000166:cytology / Q000378:metabolism*; D017127:Glycation End Products, Advanced / Q000378:metabolism*; D008297:Male; D051381:Rats; D011916:Rats, Inbred F344; D000067759:Receptor for Advanced Glycation End Products; D011971:Receptors, Immunologic / Q000096:biosynthesis* / Q000235:genetics
D017127:Glycation End Products, Advanced; D000067759:Receptor for Advanced Glycation End Products; D011971:Receptors, Immunologic