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Www.biomedcentral.com/1472-6823/10/Page 6 ofthe context of peripheral insulin resistance or T2DM. Similar results have been reported previously, in which the investigators generated models with much higher doses of NDEA [84]. One potential explanation for this paradox is that homeostatic mechanisms may have shifted toward increased storage of lipids/triglycerides in adipose tissue, skeletal muscle
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P. Chronic HFD feeding aloneTable 3 Effects of High Fat Diet and NDEA Exposure on Biomarkers of Insulin and IGF Resistance in the CerebellummRNA AbPP Tau AChE ChAT Insulin IGF-1 IGF-2 Insulin R IGF-1R IGF-2R IRS-1 IRS-2 IRS-4 LFD+VEH 7.007 ?0.828 12.230 ?1.098 2.829 ?0.178 0.701 ?0.045 0.754 ?0.048 0.957 ?0.119 12.000 ?1.800 17.090 ?1.547 5.031 ?0.525 5.677 ?0.548 5.559 ?0.411 7.701 ?0.509 0.135 ?
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Or NDEA-associated neurodegeneration and insulin/IGF resistance were likely mediated by increased brain ceramide levels. Those studies demonstrated strikingly increased expression of several genes regulating ceramide production via both de novo biosynthesis or sphingomyelin degradation pathways in NDEA-treated rats, irrespective of chronic HFD feeding. Since NDEA is lipid soluble [115,116] and can
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Ingomyelin phosphodiesterase; SPTLC: Serine palmitoyltransferase; STZ: Streptozotocin; T2DM: Type 2 diabetes mellitus; TBS: Tris buffered saline; UGCG: UDP-glucose ceramide glycoysltransferase. Acknowledgements Supported by AA-11431, AA-12908, and K24-AA-16126 from the National Institutes of Health. Author details 1 Department of Pathology (Neuropathology), Rhode Island Hospital, 593 Eddy Street,
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Agent for RNA extraction and QuantiTect SYBR Green PCR Mix were obtained from Qiagen, Inc (Valencia, CA). The AMV 1st Strand cDNAPostnatal day 3 (P3) Long Evans rat pups (mean body weight 10 g) were given 3 alternate day intra-peritoneal (i.p.) injections of 20 g NDEA or vehicle. Upon weaning, male rats (N = 8-10 per group) were pair-fed for 8 weeks with high fat (HFD) or low fat (LFD) chow diets.
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S described elsewhere [79]. For molecular and biochemical assays, cerebella were snap-frozen in a dry ice-methanol bath and stored at -80 . We studied cerebellar tissue because the cerebellum: 1) requires intact insulin/IGF signaling to maintain its structural and functional integrity [80,81]; 2) is severely damaged by i.c.-STZ mediated neurodegeneration [19,22]; 3) although relatively spared, it
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Ds, and cholesterol levels compared with LFD+VEH and LFD +NDEA treated groups. In addition, the serum free fatty acid level was significantly lower in the LFD+NDEA compared with LFD+VEH treated rats, whereas the triglyceride and cholesterol levels were similar in the two groups. Therefore, hyperglycemia, hyper-insulinemia, and hyper-leptinemia were features of chronic HFD feeding, and worsened by
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Cer. Clin Cancer Res. 2009;15(17):5308?6. 80. Degterev A, Yuan J. Expansion and evolution of cell death programmes. Nat Rev Mol Cell Biol. 2008;9(5):378?0. 81. Shen HM, Codogno P. Autophagy is a survival force via suppression of necrotic cell death. Exp Cell Res. 2012;318(11):1304?. 82. Munoz-Gamez JA, Rodriguez-Vargas JM, Quiles-Perez R, Aguilar-Quesada R, Martin-Oliva D, de Murcia G, et al. PARP