scholarly journals Low-Density Lipoprotein-Reactive T Cells Regulate Plasma Cholesterol Levels and Development of Atherosclerosis in Humanized Hypercholesterolemic Mice

Circulation ◽  
2018 ◽  
Vol 138 (22) ◽  
pp. 2513-2526 ◽  
Author(s):  
Anton Gisterå ◽  
Maria L. Klement ◽  
Konstantinos A. Polyzos ◽  
Reiner K.W. Mailer ◽  
Amanda Duhlin ◽  
...  
Author(s):  
Mei Hu ◽  
Sayantan Jana ◽  
Tolga Kilic ◽  
Faqi Wang ◽  
Mengcheng Shen ◽  
...  

Objective: Atherosclerosis is accumulation of lipids and extracellular matrix in the arterial wall. TIMPs (tissue inhibitor of metalloproteinases) can impact plaque deposition by regulating ECM (extracellular matrix) turnover. TIMP4 also influences lipid metabolism and smooth muscle cell (SMC) proliferation. We investigated the role of TIMP4 in atherosclerosis. Approach and Results: Mice lacking low-density lipoprotein receptor ( Ldlr −/− ) and Timp4 ( Timp4 −/− / Ldlr −/− ) were fed high-fat diet (HFD) or regular laboratory diet. After 3 or 6 months, HFD-fed male and female Timp4 −/− / Ldlr −/− mice exhibited higher plaque density in the abdominal aorta (but not in aortic valves, arch, thoracic aorta) compared with Ldlr −/− mice. Although plasma lipid and cholesterol levels were lower in Timp4 −/− / Ldlr −/− -HFD, cholesterol content in the abdominal aorta was higher along with elevated inflammatory cytokines, MMP (matrix metalloproteinase) activities, CD68 + /calponin + macrophage-like SMCs in Timp4 −/− / Ldlr −/− -HFD compared with Ldlr −/− -HFD mice. In vitro, oxidized LDL (low-density lipoprotein) markedly increased CD68 expression, reduced SMC markers, increased lipid uptake, and reduced cholesterol efflux protein ABCA1 (ATP-binding cassette transporter A1) in Timp4 −/− / Ldlr −/− compared with Ldlr −/− primary SMCs from abdominal, but not thoracic aorta. TIMP4 expression in the abdominal aorta (in vivo) and its corresponding SMCs (in vitro) was ≈2-fold higher than in the thoracic aorta and SMCs; TIMP4 levels decreased following HFD. Timp4 -deficiency in bone marrow–derived macrophages did not alter their foam cell formation capacity. Conclusions: TIMP4 protects against plaque deposition in the abdominal aorta independent of plasma cholesterol levels. TIMP4 prevents proteolytic degradation of ABCA1 in SMCs, hindering cholesterol accumulation and transdifferentiation to macrophage-like foam cells, representing a novel negative regulator of atherosclerosis.


Author(s):  
Jaroslav A. Hubacek ◽  
Tommy Hyatt

AbstractMutations in a putative low-density lipoprotein (LDL) receptor adaptor protein called


1973 ◽  
Vol 45 (5) ◽  
pp. 583-592 ◽  
Author(s):  
Gilbert R. Thompson ◽  
J. Paul Miller

1. Plasma lipids and lipoproteins have been studied in control subjects and patients with various types of steatorrhoea. 2. Low plasma cholesterol levels were found in malabsorbers and were associated with decreased amounts of low-density lipoprotein (LDL) in males and high-density lipoprotein (HDL) in females. 3. Serum triglyceride levels were normal in males, but exceeded control values in some of the females, due to an increase in very-low-density lipoprotein. 4. LDL composition was abnormal in both male and female malabsorbers, with a decreased proportion of cholesterol ester and an increased proportion of triglyceride. There was also an increased proportion of triglyceride in HDL. 5. These findings show that malabsorption markedly influences not only the concentration but also the composition of plasma lipoproteins.


2013 ◽  
Vol 24 (3) ◽  
pp. 437-441 ◽  
Author(s):  
Avishay Elis ◽  
Rong Zhou ◽  
Evan A. Stein

AbstractBackground:This study evaluated the effectiveness of long-term intensive lipid-lowering therapy in children and adolescents with familial hypercholesterolaemia.Methods:The charts of 89 children and adolescents with heterozygous familial hypercholesterolaemia among ∼1000 patients treated from 1974 to 2008 were reviewed. Familial hypercholesterolaemia was defined as low-density lipoprotein cholesterol level >90th percentile in individuals with a history of familial hypercholesterolaemia.Results:Of the 89 patients, 51% were male; the mean age at diagnosis was 8 ± 4 years, and the mean follow-up was 13 ± 8 years. Baseline and most recent low-density lipoprotein cholesterol levels (mg/dl) under treatment were 250 ± 50 and 142 ± 49, respectively, reduced 43% from baseline (p < 0.0001). At the most recent visit, 39 patients received statin monotherapy, mainly atorvastatin or rosuvastatin, and 50 (56%) patients received combination therapy, mainly vytorin or rosuvastain/ezetimibe, 15 patients were >30 years of age, and none developed symptomatic cardiovascular disease or needed revascularisation.Conclusions:Long-term statin-based therapy can reduce low-density lipoprotein cholesterol levels in most children and adolescents with heterozygous familial hypercholesterolaemia and decrease cardiovascular risk significantly.


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