Age-related accumulation of advanced glycation end-products-albumin, S100β, and the expressions of advanced glycation end product receptor differ in visceral and subcutaneous fat.
Visceral fat induces more inflammation by activating macrophages than subcutaneous fat, and inflammation is an underlying feature of the pathogeneses of various diseases, including cardiovascular disease and diabetes. Advanced glycation end products (AGEs), S100β, and their receptors, the receptor for advanced glycation end products (RAGE), lead to macrophage activation. However, little information is available regarding the differential accumulations of AGE-albumin (serum albumin modified by AGEs), S100β, or expressions of RAGE in different adipocyte types in fat tissues. In this study, the authors investigated whether age-related AGE-albumin accumulations S100β level, and RAGE expressions differ in subcutaneous and visceral fat tissues. Subcutaneous and visceral fat were harvested from 3- and 28-week-old rats. Macrophage activation was confirmed by Iba1 staining, and AGE-albumin accumulations and RAGE expressions were assessed by confocal microscopy. S100β were analyzed by immunoblotting. It was found that activated macrophage infiltration, AGE-albumin accumulation, and S100β in visceral fat was significantly greater in 28-week-old rats than in 3-week-old rats, but similar in subcutaneous fat. The expression of RAGE in visceral fat was much greater in 28-week-old rats, but its expression in subcutaneous fat was similar in 3- and 28-week-old rats. Furthermore, inflammatory signal pathways (NFκB, TNF-α) and proliferation pathways (FAK) in visceral fat were more activated in 28-week-old rats. These results imply that age-related AGE-albumin accumulation, S100β, and RAGE expression are more prominent in visceral than in subcutaneous fat, suggesting that visceral fat is involved in the pathogenesis of inflammation-induced diseases in the elderly.
Department of Thoracic and Cardiovascular Surgery, Gachon University Gil Medical Center, Gachon University, Incheon, Republic of Korea.
Kuk Hui
KH
Son
Department of Anatomy and Cell Biology, Gachon University Graduate School of Medicine, Incheon, Republic of Korea; Functional Cellular Networks Laboratory, Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, Republic of Korea.
Myeongjoo
M
Son
Functional Cellular Networks Laboratory, Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, Republic of Korea.
Hyosang
H
Ahn
Functional Cellular Networks Laboratory, Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, Republic of Korea.
Seyeon
S
Oh
Functional Cellular Networks Laboratory, Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, Republic of Korea.
Yoonji
Y
Yum
Department of Thoracic and Cardiovascular Surgery, Gachon University Gil Medical Center, Gachon University, Incheon, Republic of Korea.
Chang Hu
CH
Choi
Department of Thoracic and Cardiovascular Surgery, Gachon University Gil Medical Center, Gachon University, Incheon, Republic of Korea. Electronic address: kkyypark@ghil.com.
Kook Yang
KY
Park
Department of Anatomy and Cell Biology, Gachon University Graduate School of Medicine, Incheon, Republic of Korea; Functional Cellular Networks Laboratory, Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon, Republic of Korea. Electronic address: khbyun1@gachon.ac.kr.
Kyunghee
K
Byun
D050153:Abdominal Fat / Q000378:metabolism*; D000375:Aging / Q000378:metabolism*; D000818:Animals; D017127:Glycation End Products, Advanced / Q000378:metabolism*; D018836:Inflammation Mediators / Q000378:metabolism*; D050152:Intra-Abdominal Fat / Q000378:metabolism; D008264:Macrophages / Q000378:metabolism; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D000067759:Receptor for Advanced Glycation End Products / Q000378:metabolism*; D064568:S100 Calcium Binding Protein beta Subunit / Q000378:metabolism*; D012710:Serum Albumin, Bovine / Q000378:metabolism*; D050151:Subcutaneous Fat / Q000378:metabolism; D014018:Tissue Distribution
C000593874:Ager protein, rat; D017127:Glycation End Products, Advanced; D018836:Inflammation Mediators; D000067759:Receptor for Advanced Glycation End Products; D064568:S100 Calcium Binding Protein beta Subunit; C579158:S100b protein, rat; C081628:advanced glycation end products-bovine serum albumin; D012710:Serum Albumin, Bovine
Old aged rat; RAGE ligands; Subcutaneous fat; Visceral fat