Methyl-β-cyclodextrin alters adipokine gene expression and glucose metabolism in swine adipose tissue

Abstract

This study was designed to determine whether methyl-b-cyclodextrin (MCD) can substitute for albumin in incubation medium for neonatal swine adipose tissue explants, or whether MCD affects metabolism and cytokine expression. Subcutaneous adipose tissue explants (100 6 10 mg) were prepared from 21-day-old pigs. Explants were incubated in medium 199 supplemented with 25 mM HEPES, 1.0 nM insulin at 378C. The medium also contained bovine serum albumin (BSA) or MCD at 0%, 0.05%, 0.1%, 0.2% or 0.3%. Tissue explants were treated with these media for 1 h and then switched to the same basal incubation medium containing 0.05% BSA. Explants were removed from basal medium at 2 or 8 h of incubation, and real-time PCR was performed to assess expression of tumor necrosis a (TNF) and interleukin 6 (IL6), acetyl CoA carboxylase (ACAC) and fatty acid synthase (FASN). Alternatively, rates of 14 C-glucose oxidation and lipogenesis were monitored 6 insulin (100 nM), following MCD treatment. Incubation with BSA had minimal effects on gene expression or adipose tissue metabolism, only producing a doubling in TNF mRNA abundance ( P , 0.01). Treatment with MCD increased TNF mRNA abundance by eightfold ( P , 0.009), whereas IL6 gene expression increased a 100-fold ( P , 0.001) with a suppression in ACAC and FASN expression ( P , 0.01). This was paralleled by MCD inhibition of insulin-stimulated glucose oxidation and lipogenesis ( P , 0.001). Addition of a TNF antibody to the incubation medium alleviated this inhibition of insulin-stimulated glucose metabolism by ,30% ( P , 0.05).

Cell culture models of fatty acid overload: Problems and solutions

“…Corroborating this, BSA-treated human adipocytes present an increase in the expression of IL-6, IL-8 and TNF-α [136]. Interestingly, methyl-β-cyclodextrin, which can be used to replace BSA as a FA carrier, also promotes increases in the expression of pro-inflammatory cytokines by adipocytes [137]. This suggests that lipid homeostasis plays a central role in the control of inflammatory marker expression.…”

α 1-acid glycoprotein inhibits lipogenesis in neonatal swine adipose tissue

“…Primer sets for the mRNAs encoding the lipogenic Ramsay, Blomberg and Caperna enzymes ME, acetyl CoA carboxylase (CBX) and FASN were designed to span an intron as previously described and utilized for real-time PCR (Ramsay and Azain, 2007;Ramsay et al, 2013). Primers for genes important for insulin responsiveness of adipose tissue were also examined and included sterol regulatory element-binding protein 1 (SREBP), carbohydrate regulatory element-binding protein (ChREBP) and insulin receptor substrate 1 (IRS1).…”