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- Drager, Luciano F., et al.
(författare)
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Chronic Intermittent Hypoxia Induces Atherosclerosis via Activation of Adipose Angiopoietin-like 4
- 2013
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Ingår i: American Journal of Respiratory and Critical Care Medicine. - 1073-449X .- 1535-4970. ; 188:2, s. 240-248
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Tidskriftsartikel (refereegranskat)abstract
- Rationale: Obstructive sleep apnea is a risk factor for dyslipidemia and atherosclerosis, which have been attributed to chronic intermittent hypoxia (CIH). Intermittent hypoxia inhibits a key enzyme of lipoprotein clearance, lipoprotein lipase, and up-regulates a lipoprotein lipase inhibitor, angiopoietin-like 4 (Angptl4), in adipose tissue. The effects and mechanisms of Angptl4 up-regulation in sleep apnea are unknown. Objectives: To examine whether CIH induces dyslipidemia and atherosclerosis by increasing adipose Angptl4 via hypoxia-inducible factor-1 (HIF-1). Methods: ApoE(-/-) mice were exposed to intermittent hypoxia or air for 4 weeks while being treated with Angptl4-neutralizing antibody or vehicle. Measurements and Main Results: In vehicle-treated mice, hypoxia increased adipose Angptl4 levels, inhibited adipose lipoprotein lipase, increased fasting levels of plasma triglycerides and very low density lipoprotein cholesterol, and increased the size of atherosclerotic plaques. The effects of CIH were abolished by the antibody. Hypoxia-induced increases in plasma fasting triglycerides and adipose Angptl4 were not observed in mice with germline heterozygosity for a HIF-1 alpha knockout allele. Transgenic overexpression of HIF-1 alpha in adipose tissue led to dyslipidemia and increased levels of adipose Angptl4. In cultured adipocytes, constitutive expression of HIF-1 alpha increased Angptl4 levels, which was abolished by siRNA. Finally, in obese patients undergoing bariatric surgery, the severity of nocturnal hypoxemia predicted Angptl4 levels in subcutaneous adipose tissue. Conclusions: HIF-1-mediated increase in adipose Angptl4 and the ensuing lipoprotein lipase in activation may contribute to atherosclerosis in patients with sleep apnea.
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| 2. |
- Hagstrom, Hannes, et al.
(författare)
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Serum levels of endotrophin are associated with nonalcoholic steatohepatitis
- 2021
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Ingår i: Scandinavian Journal of Gastroenterology. - : Taylor & Francis. - 0036-5521 .- 1502-7708. ; 56:4, s. 437-442
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Tidskriftsartikel (refereegranskat)abstract
- Background and aimsThere are no currently available biomarkers that can accurately indicate the presence of non-alcoholic steatohepatitis (NASH). We investigated the association between endotrophin, a cleavage product of collagen type 6α3, and disease severity in patients with non-alcoholic fatty liver disease (NAFLD).MethodsWe measured serum endotrophin levels in 211 patients with NAFLD and nine healthy controls. Liver biopsy data was available for 141 (67%) of the patients. Associations between endotrophin and the presence of NASH and advanced fibrosis were investigated alone and in combination with standard clinical parameters using logistic regression.ResultsA total of 211 patients were enrolled in this study, consisting of 108 (51%) men and 103 (49%) women with a mean age of 55.6 years. 58 (27%) of the patients had advanced fibrosis. Of those with biopsy data, 87 (62%) had NASH. Serum levels of endotrophin were significantly higher in patients with NAFLD than those in healthy controls (37[±12] vs. 17[±7] ng/mL, p<.001). Serum levels of endotrophin were also significantly higher in patients with NASH than in those without NASH (40[±12] vs. 32[±13] ng/mL, p<.001). A model using age, sex, body mass index and levels of alanine aminotransferase (ALT), glucose and endotrophin effectively predicted the presence of NASH in a derivation (AUROC 0.83, 95%CI = 0.74–0.92) and validation cohort (AUROC 0.71, 95%CI = 0.54–0.88). There was no significant association between serum levels of endotrophin and advanced fibrosis.ConclusionsThese data suggest that serum endotrophin could be a valuable biomarker for diagnosing NASH, but not for detecting advanced fibrosis in NAFLD.
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| 3. |
- Wernstedt Asterholm, Ingrid, 1978, et al.
(författare)
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Adipocyte inflammation is essential for healthy adipose tissue expansion and remodeling.
- 2014
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Ingår i: Cell metabolism. - : Elsevier BV. - 1932-7420 .- 1550-4131. ; 20:1, s. 103-18
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Tidskriftsartikel (refereegranskat)abstract
- Chronic inflammation constitutes an important link between obesity and its pathophysiological sequelae. In contrast to the belief that inflammatory signals exert a fundamentally negative impact on metabolism, we show that proinflammatory signaling in the adipocyte is in fact required for proper adipose tissue remodeling and expansion. Three mouse models with an adipose tissue-specific reduction in proinflammatory potential were generated that display a reduced capacity for adipogenesis in vivo, while the differentiation potential is unaltered in vitro. Upon high-fat-diet exposure, the expansion of visceral adipose tissue is prominently affected. This is associated with decreased intestinal barrier function, increased hepatic steatosis, and metabolic dysfunction. An impaired local proinflammatory response in the adipocyte leads to increased ectopic lipid accumulation, glucose intolerance, and systemic inflammation. Adipose tissue inflammation is therefore an adaptive response that enables safe storage of excess nutrients and contributes to a visceral depot barrier that effectively filters gut-derived endotoxin.
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| 4. |
- Wernstedt Asterholm, Ingrid, 1978, et al.
(författare)
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Elevated resistin levels induce central leptin resistance and increased atherosclerotic progression in mice.
- 2014
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Ingår i: Diabetologia. - : Springer Science and Business Media LLC. - 1432-0428 .- 0012-186X. ; 57:1, s. 1209-1218
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Tidskriftsartikel (refereegranskat)abstract
- Resistin was originally identified as an adipocyte-derived factor upregulated during obesity and as a contributor to obesity-associated insulin resistance. Clinically, resistin has also been implicated in cardiovascular disease in a number of different patient populations. Our aim was to simultaneously address these phenomena.
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