Project description:Atherosclerosis is an inflammatory disease linked to elevated blood cholesterol levels. Despite ongoing advances in the prevention and treatment of atherosclerosis 1, cardiovascular disease remains the leading cause of death worldwide 2. Continuous retention of apolipoprotein B-containing lipoproteins in the subendothelial space causes a local overabundance of free cholesterol. Since cholesterol accumulation and deposition of cholesterol crystals (CCs) triggers a complex inflammatory response 3 4, we tested the therapeutic potential of increasing cholesterol solubility in experimental atherogenesis. Here we show that treatment of murine atherosclerosis with the cyclic oligosaccharide 2-hydroxypropyl-β-cyclodextrin (CD), a compound that solubilizes lipophilic substances, reduced atherosclerotic plaque size, cholesterol crystal load and promoted plaque regression even under continuing Western diet. CD solubilized CCs and promoted cholesterylester and oxysterol production in macrophages leading to liver X receptor (LXR)-mediated transcriptional reprogramming. CD increased cholesterol efflux from macrophages and substantially augmented reverse cholesterol transport in vivo. Furthermore, CD reduced proinflammatory cytokines in vivo and decreased macrophage responsiveness towards TLR and inflammasome activation. Since CD treatment in humans is safe and CD beneficially affects key pathogenetic factors in atherogenesis it may thus be used clinically to prevent or treat human atherosclerosis .
Project description:Atherosclerosis is an inflammatory disease linked to elevated blood cholesterol levels. Despite ongoing advances in the prevention and treatment of atherosclerosis 1, cardiovascular disease remains the leading cause of death worldwide 2. Continuous retention of apolipoprotein B-containing lipoproteins in the subendothelial space causes a local overabundance of free cholesterol. Since cholesterol accumulation and deposition of cholesterol crystals (CCs) triggers a complex inflammatory response 3 4, we tested the therapeutic potential of increasing cholesterol solubility in experimental atherogenesis. Here we show that treatment of murine atherosclerosis with the cyclic oligosaccharide 2-hydroxypropyl-β-cyclodextrin (CD), a compound that solubilizes lipophilic substances, reduced atherosclerotic plaque size, cholesterol crystal load and promoted plaque regression even under continuing Western diet. CD solubilized CCs and promoted cholesterylester and oxysterol production in macrophages leading to liver X receptor (LXR)-mediated transcriptional reprogramming. CD increased cholesterol efflux from macrophages and substantially augmented reverse cholesterol transport in vivo. Furthermore, CD reduced proinflammatory cytokines in vivo and decreased macrophage responsiveness towards TLR and inflammasome activation. Since CD treatment in humans is safe and CD beneficially affects key pathogenetic factors in atherogenesis it may thus be used clinically to prevent or treat human atherosclerosis .
Project description:Atherosclerosis is an inflammatory disease linked to elevated blood cholesterol concentrations. Despite ongoing advances in the prevention and treatment of atherosclerosis, cardiovascular disease remains the leading cause of death worldwide. Continuous retention of apolipoprotein B-containing lipoproteins in the subendothelial space causes a local overabundance of free cholesterol. Because cholesterol accumulation and deposition of cholesterol crystals (CCs) trigger a complex inflammatory response, we tested the efficacy of the cyclic oligosaccharide 2-hydroxypropyl-?-cyclodextrin (CD), a compound that increases cholesterol solubility in preventing and reversing atherosclerosis. We showed that CD treatment of murine atherosclerosis reduced atherosclerotic plaque size and CC load and promoted plaque regression even with a continued cholesterol-rich diet. Mechanistically, CD increased oxysterol production in both macrophages and human atherosclerotic plaques and promoted liver X receptor (LXR)-mediated transcriptional reprogramming to improve cholesterol efflux and exert anti-inflammatory effects. In vivo, this CD-mediated LXR agonism was required for the antiatherosclerotic and anti-inflammatory effects of CD as well as for augmented reverse cholesterol transport. Because CD treatment in humans is safe and CD beneficially affects key mechanisms of atherogenesis, it may therefore be used clinically to prevent or treat human atherosclerosis.
Project description:Atherosclerosis is an inflammatory disease linked to elevated blood cholesterol levels. Since cholesterol retention and cholesterol crystals in arterial walls are key pathogenetic factors for atherogenesis, we assessed the therapeutic potential of increasing cholesterol solubility in vivo. Here we show that treatment of murine atherosclerosis with the cyclic oligosaccharide 2-hydroxypropyl-β-cyclodextrin (CD), a compound that solubilizes lipophilic substances, reduced atherosclerotic plaque size, cholesterol crystal (CC) load and promoted plaque regression even under continuing Western diet. CD solubilized CC and promoted cholesterylester and oxysterol production in macrophages leading to liver X receptor-mediated transcriptional reprogramming with increased cholesterol efflux and decreased inflammation. CD treatment may thus be used to increase cholesterol solubility and clearance to prevent or treat atherosclerosis.
Project description:We have previously shown that mouse atherosclerosis regression involves monocyte-derived (CD68+) cell emigration from plaques and is dependent on the chemokine receptor CCR7. Concurrent with regression, mRNA levels of the gene encoding LXRalpha are increased in plaque CD68+ cells, suggestive of a functional relationship between LXR and CCR7. To extend these results, atherosclerotic Apoe-/- mice sufficient or deficient in CCR7 were treated with an LXR agonist, resulting in a CCR7-dependent decrease in plaque CD68+ cells. To test the requirement for LXR for CCR7-dependent regression, we transplanted aortic arches from atherosclerotic Apoe-/- mice, or from Apoe-/- mice with BM deficiency of LXRalpha or LXRbeta, into WT recipients. Plaques from both LXRalpha and LXRbeta-deficient Apoe-/- mice exhibited impaired regression. In addition, the CD68+ cells displayed reduced emigration and CCR7 expression. Using an immature DC line, we found that LXR agonist treatment increased Ccr7 mRNA levels. This increase was blunted when LXRalpha and LXRbeta levels were reduced by siRNAs. Moreover, LXR agonist treatment of primary human immature DCs resulted in functionally significant upregulation of CCR7. We conclude that LXR is required for maximal effects on plaque CD68+ cell expression of CCR7 and monocyte-derived cell egress during atherosclerosis regression in mice.
Project description:BackgroundAtherosclerosis is a fundamental pathological process responded to some serious cardiovascular events. Although the cholesterol-lowering drugs are widely prescribed for atherosclerosis therapy, it is still the leading cause of death in the developed world. Here we measured the effects of compound K in atherosclerosis formation and investigated the probably mechanisms of the anti-antherosclerosis roles of compound K.MethodsWe treated the atherosclerotic model animals (apoE(-/-) mice on western diet) with compound K and measured the size of atherosclerotic lesions, inflammatory cytokine levels and serum lipid profile. Peritoneal macrophages were collected in vitro for the foam cell and inflammasome experiments.ResultsOur results show that treatment with compound K dose-dependently attenuates the formation of atherosclerotic plaques by 55% through activation of reverse cholesterol transport pathway, reduction of systemic inflammatory cytokines and inhibition of local inflammasome activity. Compound K increases the cholesterol efflux of macrophage-derived foam cells, and reduces the inflammasome activity in cholesterol crystal stimulated macrophages. The activation of LXR? may contribute to the athero-protective effects of compound K.ConclusionThese observations provide evidence for an athero-protective effect of compound K via LXR? activation, and support its further evaluation as a potential effective modulator for the prevention and treatment of atherosclerosis.