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Grosskopf I.,The Bert Strassburger Lipid Center | Shaish A.,The Bert Strassburger Lipid Center | Charach G.,Tel Aviv Sourasky Medical Center | Charach G.,Tel Aviv University | And 5 more authors.
Hormone and Metabolic Research | Year: 2015

Hypertension, advanced age, postprandial hyperlipidemia, and insulin resistance are major risk factors for atherosclerosis. The calcium channel blocker nifedipine is reported to ameliorate insulin resistance possibly by activating PPARγ. This is expected to become accentuated in elderly individuals due to age-related insulin resistance. Insulin resistance modulates lipoprotein metabolism. Therefore, we reasoned that nifedipne offers the potential for improving postprandial lipemia in association with increasing age. We studied the effect of nifedipine on fasting lipids, postprandial lipemia, insulin sensitivity, and plasma lipolytic activity in 24 and 15 hypertensive subjects aged 70–75 years and 40–45 years, respectively. As expected, nifedipine significantly lowered systolic and diastolic blood pressure. Nifedipine decreased fasting triglyceride level (23%) and increased HDL-C (15%) in the elderly group. At baseline, postprandial triglyceride levels were remarkably elevated in elderly compared to younger patients (1 288±798 vs. 501±260 mg·dl−1·h, p<0.05), as was retinyl palmitate (surrogate marker for intestinally-derived cholesterol) in the chylomicrons (45.0±26.5 vs. 23.4±10.6 mg·l−1·h, p<0.05) and chylomicron remnant (15.2±5.4 vs. 11.7±4.7 mg·l−1·h, p<0.05) fractions. Importantly, while the level of chylomicron remnants in the group of younger subjects remained unchanged after treatment, nifedipine was associated with a significantly decreased chylomicron remnants retinyl palmitate in the elderly group, which dropped to levels, observed in younger subjects. This was accompanied by enhanced insulin sensitivity and augmented plasma lipolytic activity. The present work suggests that nifedipine has favorable metabolic effects that are beyond the known enhancement of insulin sensitivity. The improvement in postprandial lipidemia by nifedipine may add to its anti-atherogenic effects in hypertensive patients. Copyright © 2015, Georg Thieme Verlag KG. All rights reserved.

Kamari Y.,The Bert Strassburger Lipid Center | Kamari Y.,Tel Aviv University | Shaish A.,The Bert Strassburger Lipid Center | Shemesh S.,The Bert Strassburger Lipid Center | And 12 more authors.
Biochemical and Biophysical Research Communications | Year: 2011

Objective: Interleukin (IL)-1α and IL-1β are products of macrophages, endothelial cells and vascular smooth muscle cells; moreover, each of these cell types is affected by the pro-inflammatory properties of both IL-1's. Whereas several studies demonstrate the proatherogenic properties of IL-1β, the role of IL-1α in atherogenesis remains unclear. We assessed whether IL-1α and IL-1β from tissue resident vascular cells or emigrating bone marrow-derived cells promote the development of atherosclerosis in apoE-/- mice and determined the effect of selective macrophage IL-1α or IL-1β deficiency on degradation of LDL and cytokine production. Methods: We generated strains of double knock-out (KO) mice (apoE-/-/IL-1α-/- and apoE-/-/IL-1β-/-) and created chimeras consisting of apoE-/- mice reconstituted with bone marrow-derived cells from apoE-/-/IL-1+/+, apoE-/-/IL-1α-/- and apoE-/-/IL-1β-/- Results: The areas of aortic sinus lesions were lower in either double KO mice compared to solely apoE-/- mice, despite higher non-HDL cholesterol levels. Importantly, selective deficiency of IL-1α or IL-1β in bone marrow-derived cells inhibited atherogenesis to the same extent as in double KO mice without affecting plasma lipids. Aortic sinus lesions in apoE-/- mice transplanted with IL-1β-/- or IL-1α-/- cells were 32% and 52% lower, respectively, than in IL-1+/+ transplanted mice. Ex vivo, isolated IL-1α-/- macrophages from atherosclerotic mice degraded LDL and secreted IL-6, TNFα and IL-12 similarly to IL-1+/+ macrophages; however, IL-1α deficient macrophages secreted reduced levels of IL-1β (-50%) and 2-3-fold higher levels of the anti-inflammatory cytokine IL-10. Conclusion: We show for the first time that it is IL-1α from bone marrow-derived cells that accelerates atherogenesis in apoE-deficient mice rather than constitutive IL-1α in vascular cells, possibly by increasing the inflammatory cytokine profile of macrophages. © 2011 Elsevier Inc.

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