title: Allergen exposure induces adipose tissue inflammation and insulin resistance.
abstract: This study investigates whether exposure to allergen elicits insulin resistance as a result of adipose tissue inflammation. Male C57BL/6 mice were challenged with ovalbumin (OVA) allergen for 12 weeks, and blood and adipose tissue samples were collected at 24h after the last challenge. Levels of adhesion molecules, fasting insulin, fasting glucose, and adipokines in the blood were analyzed, and fasting homeostasis model assessment was applied to determine insulin resistance (HOMA-IR). The expression of pro- and anti-inflammatory genes in dissected adipose tissues was analyzed by real-time RT-PCR. Our results showed that OVA exposure increased insulin resistance as well as resistin and E-selectin, but reduced adiponectin in the serum. Resistin level was significantly correlated with HOMA-IR. Moreover, in adipose tissues of OVA-challenged mice, the pro-inflammatory M1 genes were more abundant while the anti-inflammatory M2 genes were less than those of PBS-treated mice. The expressional changes of both M1 and M2 genes were significantly associated with serum levels of adiponectin, resistin, and E-selectin. Hematoxylin and eosin (HE) and immunohistochemistry (IHC) stain also showed that there was more obvious inflammation in OVA-challenged mice. In conclusion, the current study suggests the relationship between allergen-elicited adipose tissue inflammation and circulating inflammatory molecules, which are possible mediators for the development of insulin resistance. Therefore, we propose that allergen exposure might be one risk factor for insulin resistance.
authors.affiliation: Department of Environmental and Occupational Health, Out-Patient Building, College of Medicine, National Cheng Kung University, 138 Sheng-Li Road, Tainan 70403, Taiwan. Electronic address: s7897102@mail.ncku.edu.tw.
authors.forename: Chien-Cheng
authors.initials: CC
authors.lastname: Jung
authors.affiliation: Institute of Clinical Medicine, Out-Patient Building, College of Medicine, National Cheng Kung University, 138 Sheng-Li Road, Tainan 70403, Taiwan. Electronic address: yaustsai@mail.ncku.edu.tw.
authors.forename: Yau-Sheng
authors.initials: YS
authors.lastname: Tsai
authors.affiliation: Department of Environmental and Occupational Health, Out-Patient Building, College of Medicine, National Cheng Kung University, 138 Sheng-Li Road, Tainan 70403, Taiwan. Electronic address: chang3@mail.ncku.edu.tw.
authors.forename: Chih-Ching
authors.initials: CC
authors.lastname: Chang
authors.affiliation: Institute of Occupational Medicine and Industrial Hygiene, College of Public Health, National Taiwan University, 17 Xuzhou Road, Taipei 10055, Taiwan. Electronic address: tcheng@ntu.edu.tw.
authors.forename: Tsun-Jen
authors.initials: TJ
authors.lastname: Cheng
authors.affiliation: Institute of Environmental Health, College of Public Health, National Taiwan University, 17 Xuzhou Road, Taipei 10055, Taiwan. Electronic address: chingwenchang@ntu.edu.tw.
authors.forename: Ching-Wen
authors.initials: CW
authors.lastname: Chang
authors.affiliation: Institute of Clinical Medicine, Out-Patient Building, College of Medicine, National Cheng Kung University, 138 Sheng-Li Road, Tainan 70403, Taiwan. Electronic address: larry@mail.ncku.edu.tw.
authors.forename: Ping-Yen
authors.initials: PY
authors.lastname: Liu
authors.affiliation: Department of Environmental and Occupational Health, Out-Patient Building, College of Medicine, National Cheng Kung University, 138 Sheng-Li Road, Tainan 70403, Taiwan. Electronic address: yijen5395@gmail.com.
authors.forename: Yi-Jen
authors.initials: YJ
authors.lastname: Chiu
authors.affiliation: Department of Environmental and Occupational Health, Out-Patient Building, College of Medicine, National Cheng Kung University, 138 Sheng-Li Road, Tainan 70403, Taiwan. Electronic address: hjsu@mail.ncku.edu.tw.
authors.forename: Huey-Jen
authors.initials: HJ
authors.lastname: Su
mesh_terms: D052242:Adiponectin / Q000097:blood; D000273:Adipose Tissue / Q000276:immunology*; D000485:Allergens / Q000276:immunology*; D000818:Animals; D019040:E-Selectin / Q000378:metabolism; D004781:Environmental Exposure; D006801:Humans; D006967:Hypersensitivity / Q000276:immunology*; D007249:Inflammation / Q000276:immunology*; D007333:Insulin Resistance / Q000276:immunology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010047:Ovalbumin / Q000276:immunology; D052243:Resistin / Q000378:metabolism
chemical_list: D052242:Adiponectin; D000485:Allergens; D019040:E-Selectin; D052243:Resistin; D010047:Ovalbumin
keywords: Adipose tissue; Allergen; Insulin resistance