scholarly journals Meta-Analysis of Low Density Lipoprotein Receptor (LDLR) rs2228671 Polymorphism and Coronary Heart Disease

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Huadan Ye ◽  
Qianlei Zhao ◽  
Yi Huang ◽  
Lingyan Wang ◽  
Haibo Liu ◽  
...  

Low density lipoprotein receptor (LDLR) can regulate cholesterol metabolism by removing the excess low density lipoprotein cholesterol (LDL-C) in blood. Since cholesterol metabolism is often disrupted in coronary heart disease (CHD),LDLRas a candidate gene of CHD has been intensively studied. The goal of our study is to evaluate the overall contribution ofLDLRrs2228671 polymorphism to the risk of CHD by combining the genotyping data from multiple case-control studies. Our meta-analysis is involved with 8 case-control studies among 7588 cases and 9711 controls to test the association betweenLDLRrs2228671 polymorphism and CHD. In addition, we performed a case-control study ofLDLRrs2228671 polymorphism with the risk of CHD in Chinese population. Our meta-analysis showed that rs2228671-T allele was significantly associated with a reduced risk of CHD (P=0.0005, odds ratio (OR) = 0.83, and 95% confidence interval (95% CI) = 0.75–0.92). However, rs2228671-T allele frequency was rare (1%) and was not associated with CHD in Han Chinese (P=0.49), suggesting an ethnic difference ofLDLRrs2228671 polymorphism. Meta-analysis has established rs2228671 as a protective factor of CHD in Europeans. The lack of association in Chinese reflects an ethnic difference of this genetic variant between Chinese and European populations.

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Dianaly T. Au ◽  
Mary Migliorini ◽  
Dudley K. Strickland ◽  
Selen C. Muratoglu

Hepatic inflammation is associated with the development of insulin resistance, which can perpetuate the disease state and may increase the risk of metabolic syndrome and diabetes. Despite recent advances, mechanisms linking hepatic inflammation and insulin resistance are still unclear. The low-density lipoprotein receptor-related protein 1 (LRP1) is a large endocytic and signaling receptor that is highly expressed in macrophages, adipocytes, hepatocytes, and vascular smooth muscle cells. To investigate the potential role of macrophage LRP1 in hepatic inflammation and insulin resistance, we conducted experiments using macrophage-specific LRP1-deficient mice (macLRP1−/−) generated on a low-density lipoprotein receptor knockout (LDLR−/−) background and fed a Western diet. LDLR−/−; macLRP1−/− mice gained less body weight and had improved glucose tolerance compared to LDLR−/− mice. Livers from LDLR−/−; macLRP1−/− mice displayed lower levels of gene expression for several inflammatory cytokines, including Ccl3, Ccl4, Ccl8, Ccr1, Ccr2, Cxcl9, and Tnf, and reduced phosphorylation of GSK3α and p38 MAPK proteins. Furthermore, LRP1-deficient peritoneal macrophages displayed altered cholesterol metabolism. Finally, circulating levels of sFRP-5, a potent anti-inflammatory adipokine that functions as a decoy receptor for Wnt5a, were elevated in LDLR−/−; macLRP1−/− mice. Surface plasmon resonance experiments revealed that sFRP-5 is a novel high affinity ligand for LRP1, revealing that LRP1 regulates levels of this inhibitor of Wnt5a-mediated signaling. Collectively, our results suggest that LRP1 expression in macrophages promotes hepatic inflammation and the development of glucose intolerance and insulin resistance by modulating Wnt signaling.


2020 ◽  
Author(s):  
Roxane St-Amand ◽  
Emilienne T. Ngo Sock ◽  
Samantha Quinn ◽  
Jean-Marc Lavoie ◽  
David H. St-Pierre

Abstract Background: The present study was designed to test the hypothesis that in the liver, excessive fat accumulation impairs cholesterol metabolism mainly by altering the low-density lipoprotein-receptor (LDL-R) pathway. Method: Young male Wistar rats were fed standard (SD), high fat (HFD; 60% kcal) or Western (WD; 40% fat + 35% sucrose (17.5% fructose)) diets for 2 or 6 weeks. Results: Weight gain (~ 40g) was observed only following 6 weeks of the obesogenic diets (P < 0.01). Compared to the 2-week treatment, obesogenic diets tripled fat pad weight (~ 20 vs 7 g) after 6 weeks. Hepatic triglyceride (TG) levels were greater in response to both the WD and HFD compared to the SD (P < 0.01) at 2 and 6 weeks and their concentrations were greater (P < 0.05) in WD than HFD at 2 weeks. Plasma total cholesterol levels were higher (P < 0.05) in animals submitted to WD. After 2 and 6 weeks, liver expression of LDL-R, proprotein convertase subtilisin/kexin 9 (PCSKk9) and sterol regulatory element binding protein 2 (SREBP2), involved in LDL-cholesterol uptake, was lower in animals submitted to WD than in others treated with HFD or SD (P < 0.01). Similarly, low-density lipoprotein-receptor-related protein 1 (LRP1) and acyl-CoA cholesterol acyltransferase-2 (ACAT-2) mRNA levels were lower (P < 0.01) among WD compared to SD-fed rats. Expression of the gene coding the main regulator of endogenous cholesterol synthesis, 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMGCoAR) was reduced in response to WD compared to SD and HFD at 2 (P < 0.001) and 6 (P < 0.05) weeks. Being enriched in fructose, the WD strongly promoted the expression of carbohydrate-response element binding protein (ChREBP) and acetyl-CoA carboxylase (ACC), two key regulators of de novo lipogenesis. Conclusion: These results show that the WD promptly increased TG levels in the liver by potentiating fat storage. This impaired the pathway of hepatic cholesterol uptake via the LDL-R axis, promoting a rapid increase in plasma total cholesterol levels. These results indicate that liver fat content is a factor involved in the regulation of plasma cholesterol.


2019 ◽  
Vol 2019 ◽  
pp. 1-6 ◽  
Author(s):  
Zulaika Roslan ◽  
Mudiana Muhamad ◽  
Lakshmi Selvaratnam ◽  
Sharaniza Ab-Rahim

Low-density lipoprotein receptor (LDLR) has been an object of research since the 1970s because of its role in various cell functions. The LDLR family members include LRP5, LRP6, and LRP8. Even though LRP5, 6, and 8 are in the same family, intriguingly, these three proteins have various roles in physiological events, as well as in regulating different mechanisms in various kinds of cancers. LRP5, LRP6, and LRP8 have been shown to play important roles in a broad panel of cancers. LRP5 is highly expressed in many tissues and is involved in the modulation of glucose-induced insulin secretion, bone development, and cholesterol metabolism, as well as cancer progression. Recently, LRP5 has also been shown to play a role in chondroblastic subtype of osteosarcoma (OS) and prostate cancer and also in noncancer case such as osteoporosis. LRP6, which has been previously discovered to share the same structures as LRP5, has also been associated with many cancer progressions such as human triple negative breast cancer (TNBC), primary chronic lymphocytic leukemia (CLL), nonsmall cell lung cancer (NSCL), lung squamous cell carcinoma (LSCC), and hepatocellular carcinoma (HCC). In addition to its role in cancer progression, LRP8 (apolipoprotein E receptor 2 [APOER2]) has also been demonstrated to regulate canonical Wnt/β-catenin signaling pathway whereby this pathway plays a role in cell migration and development. Therefore, this review aimed to elucidate the role of LRP 5, 6, and 8 in regulating the cancer progression.


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