Atherosclerotic cardiovascular disease is the main cause of mortality and morbidity in the world. Plasma levels of low density lipoprotein cholesterol (LDL-C) are positively correlated with the risk of atheroscleros...Atherosclerotic cardiovascular disease is the main cause of mortality and morbidity in the world. Plasma levels of low density lipoprotein cholesterol (LDL-C) are positively correlated with the risk of atherosclerosis. High plasma LDL concentrations in patients with hypercholesterolemia lead to build-up of LDL in the inner walls of the arteries, which becomes oxidized and promotes the formation of foam cells, consequently initiating atherosclerosis. Plasma LDL is mainly cleared through the LDL receptor (LDLR) pathway. Mutations in the LDLR cause familiar hyperch- olesterolemia and increase the risk of premature coronary heart disease. The expression of LDLR is regulated at the transcriptional level via the sterol regulatory element binding protein 2 (SREBP-2) and at the posttranslational levels mainly through proprotein convertase subtilisin/kexin-type 9 (PCSK9) and inducible degrader of the LDLR (IDOL). In this review, we summarize the latest advances in the studies of PCSK9.展开更多
Objective: To investigate the molecular mechanisms and effective target ponits of lipid-lowering drug, Rhizoma Curcumae Longae, and study the effect of curcumin on the expression of low density lipoprotein (LDL) re...Objective: To investigate the molecular mechanisms and effective target ponits of lipid-lowering drug, Rhizoma Curcumae Longae, and study the effect of curcumin on the expression of low density lipoprotein (LDL) receptors in macrophages in mice. Methods. Macrophages in mice were treated with curcumin, which was purified from the ethanolly extraction of Rhizoma Curcumae Longae for 24 h. The LDL receptors expressed in the macrophages were determined by enzyme-linked immunosorbent assay (ELISA) and assay of Dil labeled LDL uptake by flow cytometer. Results: It was found for the first time that 10 μmol/L-50 μmol/L curcumin could obviously up-regulate the expression of LDL receptor in macrophages in mice, and a dose-effect relationship was demonstrated. Conclusion: One of the lipid-lowering mechanisms of traditional Chinese medicine, Rhizoma Curcumae Longae, was completed by the effect of curcumin through the up-regulation of the expression of LDL receptor.展开更多
To explore the functions of very low density lipoprotein receptor (VLDL-R) subtype II in lipoprotein metabolism and foam cells formation, the recombinant plasmid with the two subtypes cDNA was constructed respectively...To explore the functions of very low density lipoprotein receptor (VLDL-R) subtype II in lipoprotein metabolism and foam cells formation, the recombinant plasmid with the two subtypes cDNA was constructed respectively, the ldl-A7 cell lines were transfected and two cell lines expressing VLDL-R were obtained: one stably expressing the VLDLR with the O-linked sugar region (type I VLDLR) and the other without the O-linked sugar region (type II VLDLR). In the study on binding of VLDLR to their nuclein labeled natural ligands (VLDL and β-VLDL), it was found that surface binding of 125I-VLDL or 125I-β-VLDL of ldl-A7 cells transfected with type I VLDLR recombinant (ldl-A7-VRI) was more higher than that of ldl-A7 cells transfected with type II VLDLR recombinant (ldl-A7-VRII). After being incubated with VLDL for different time, the contents of triglyceride and total cholesterol in cells were mensurated, and the formation of foam cells and accumulation of lipid in cells was observed by oil-red O staining. The results showed that the contents of triglyceride and total cholesterol in ldl-A7-VR I were much higher than those in ldl-A7-VR II, and ldl-A7-VR I could transform into foam cells notably. It was suggested that type I VLDLR binds with relative higher affinity to VLDL and β-VLDL, and internalizes much more lipoprotein into cells. As a result, we can conclude that type I VLDLR plays a more important role in lipoprotein metabolism and foam cells formation than type II VLDLR.展开更多
Low-density lipoprotein receptor-related protein 1(LRP1,also known as CD91),a multifunctional endocytic and cell signaling receptor,is widely expressed on the surface of multiple cell types such as hepatocytes,fibrobl...Low-density lipoprotein receptor-related protein 1(LRP1,also known as CD91),a multifunctional endocytic and cell signaling receptor,is widely expressed on the surface of multiple cell types such as hepatocytes,fibroblasts,neurons,astrocytes,macrophages,smooth muscle cells,and malignant cells.Emerging in vitro and in vivo evidence demonstrates that LRP1 is critically involved in many processes that drive tumorigenesis and tumor progression.For example,LRP1 not only promotes tumor cell migration and invasion by regulating matrix metalloproteinase(MMP)-2and MMP-9 expression and functions but also inhibits cell apoptosis by regulating the insulin receptor,the serine/threonine protein kinase signaling pathway,and the expression of Caspase-3.LRPI-mediated phosphorylation of the extracellular signal-regulated kinase pathway and c-jun N-terminal kinase are also involved in tumor cell proliferation and invasion.In addition,LRP1 has been shown to be down-regulated by microRNA-205 and methylation of LRP1CpG islands.Furthermore,a novel fusion gene,LRP1-SNRNP25,promotes osteosarcoma cell invasion and migration.Only by understanding the mechanisms of these effects can we develop novel diagnostic and therapeutic strategies for cancers mediated by LRP1.展开更多
Objective To investigate the association between low-density lipoprotein receptor-related protein 5 (LRPS) variants (rs12363572 and rs4930588) and type 2 diabetes mellitus (T2DM) in Han Chinese. Methods A total ...Objective To investigate the association between low-density lipoprotein receptor-related protein 5 (LRPS) variants (rs12363572 and rs4930588) and type 2 diabetes mellitus (T2DM) in Han Chinese. Methods A total of 1842 T2DM cases (507 newly diagnosed cases and 1335 previously diagnosed cases) and 7777 controls were included in this case-control study. PCR-RFLP was conducted to detect the genotype of the two single nucleotide polymorphisms (SNPs). Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated to describe the strength of the association by logistic regression. Results In the study subjects, neither rs12363572 nor rs4930588 was significantly associated with T2DM, even after adjusting for relevant covariates. When stratified by body mass index (BMI), the two SNPs were also not associated with T2DM. Among the 3 common haplotypes, only haplotype ~ was associated with reduced risk of T2DM (OR 0.820, 95% CI 0.732-0.919). In addition, rs12363572 was associated with BMI (P〈0.001) and rs4930588 was associated with triglyceride levels (P=0.043) in 507 newly diagnosed T2DM cases but not in healthy controls. Conclusion No LRP5 variant was found to be associated with T2DM in Han Chinese, but haplotype TT was found to be associated with T2DM.展开更多
Objectives Bai Ku Yao(White-trousers Yaos)is a special branch of Yao minority in China.They are now living in both Lihu and Baxu villages,Nandan County, Guangxi,China.The population size is about 30,000.The special cu...Objectives Bai Ku Yao(White-trousers Yaos)is a special branch of Yao minority in China.They are now living in both Lihu and Baxu villages,Nandan County, Guangxi,China.The population size is about 30,000.The special customs and culture of Bai Ku Yao,including their special clothing,intra-ethnic marriages and alcohol intake are still completely conserved to the present day.In previous epidemiologic studies,we found that the serum lipid levels and the prevalence of hyperlipidaemia were lower in Bai Ku Yao than in Han Chinese from the same region.This ethnic difference in serum lipid profiles is still not well known.We hypothesized that there may be significant differences in some genetic polymorphismsssociation of low density lipoprotein receptor (LDL-R) genepolymorphism and several environmental factors with serum lipid levels in the Guangxi Bai Ku Yao and Han populations.Methods A total of 1024 subjects of Bai Ku Yao and 792 participants of Han Chinese were stud- ied by a stratified randomized cluster sampling.Epidemiological survey was carried out using internationally standardized methods.Information on demographics,socioeconomic status, and lifestyle factors was collected with standardized questionnaires. The height,weight,waist circumference,blood pressure, and serum total cholesterol(TC),triglyceride(TG), high-density lipoprotein cholesterol(HDL-C),low-density lipoprotein cholesterol(LDL-C),apolipoprotein(Apo) A1, and ApoB were measured.Body massindex(BMI,kg/m2) was calculated.Genotyping of the LDL-RAvaⅡwas performed by polymerse chain reaction and restriction fragment length polymorphism combined with gel electrophoresis,and then confirmed by direct sequencing.Results(l)The height,weight,serum TC,HDL-C,LDL-C,ApoAl levels and the ratio of ApoAl to ApoB were lower in Bai Ku Yao than in Han Chinese(P【0.01 for all),whereas the percentage of subjects who consumed alcohol or smoked cigarettes was higher in Bai Ku Yao than in Han Chinese(P【0.01 for each).(2) The frequency of A+ allele in Bai Ku Yao was 34.5%,and the frequencies of A-A-,A-A+ and A+A + genotypes were 42.6%,45.9%and 11.5%;respectively. The frequency of A+ allele in Han Chinese was 19.3%(P【0.001),and the frequencies of A-A-,A-A + and A+A+ genotypes were 64.9%,31.6%and 3.5%(P【0.001);respectively. The frequencies of A-A-,A-A+ and A+A+ genotypes in Bai Ku Yao were significant difference between males and females,between normal TC and high TC subgroup, and between normal LDL-C and high LDL-C subgroup (P【0.05 for all),whereas the frequencies of A- and A+ ? alleles in Han Chinese were significant difference between males and females(P【0.05).(3) Serum LDL-C levels in Bai Ku Yao were significant difference among the A-A-, A-A+ and A+A+ genotypes(P【0.05),the A+ carriers had higher serum LDL-C levels.Serum HDL-C levels in Han Chiese were significant difference among the A-A-,A-A + and A+A+ genotypes(P【0.01),the A+ carriers had higher serum HDL-C levels.(4) After adjusting other factors,the prevalence of LDL-C abnormality was still higher in Han Chiese than in Bai Ku Yao.The prevalence of TC abnormality in Han Chinese was almost twice high as in Bai Ku Yao. The age and diet were common risk factor for TC abnormality. No effect of AvaⅡgenotype or alcohol consumption on the TC abnormality was found,but the combination of geno-type and alcohol consumption can increase the prevalence of TC abnormality[Exp(B) =(1.154)].Age was negatively cor- related with TG level.Conclusions Serum TC and LDL-C levels were lower in Bai Ku Yao than in Han Chinese.There were significant differences in the AvaⅡallele and genotype frequencies between the he A+ carriers in Bai Ku Yao had higher serum LDL-C levels,whereas the A+ carriers in Han had higher serum HDL-C levels.Interactions between alcohol consumption or cigarette smoking and the LDL-R AvaⅡgenotype were also observed.The differences in the serum lipid profiles between the two ethnic groups might partly result from different genotypic frequency of LDL-R AvaⅡpolymorphism or differentgene-enviromental interactions.Bai Ku Yao and Han population,the frequency of A + allele was higher in Bai Ku Yao than in Han.T between the two ethnic groups.Therefore,the aim of the present study was to detect the展开更多
Objective.- To investigate the prevention by Tongxinluo capsule (通心络胶囊, TXL) of vascular lesions and its effect on the levels of protein and gene expression of lectin-like oxidized low-density lipoprotein recep...Objective.- To investigate the prevention by Tongxinluo capsule (通心络胶囊, TXL) of vascular lesions and its effect on the levels of protein and gene expression of lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) of vascular wall in rabbits with atherosclerosis (AS), and to explore its possible mechanism against AS. Methods: AS models were established by feeding New Zealand white rabbits with high-cholesterol diet, and 24 immature rabbits were randomly divided into the control group, model group and treated group (treated with TXL capsule). The indexes of total cholesterol (TO) and low density lipoprotein (LDL) levels were measured at the 16th week. The intima thickness and the plaque area of abdominal aorta were quantitatively analyzed by pathological morphological analysis, the expression of macrophage and smooth muscle cell (SMC) in intima were detected by immunohistochemical method and histologic segments were stained by Hematoxilin-Eosin (HE) to identify the degree of atherosclerotic lesion in the model group and the prevention by TXL. The LOX-1 gene and protein expression in abdominal aorta was detected by semi-quantitative RT-PCR and immunohistochemistry, respectively. Results: In the model group, the levels of TC and LDL were significantly elevated, aortic intima thickened extensively, the intima area enhanced, and macrophages expression increased; the levels of LOX-1 gene and protein expression was up-regulated in endothelium and neo-intima of the abdominal aorta. The treatment with TXL reduced blood lipids, attenuated arterial intimal proliferation, markedly inhibited the expression of macrophage and excessively expressed the level of LOX-1. Conclusion:TXL has an inhibitory effect on blood lipids, and it can prevent the occurrence of vascular lesion and cure its development, and its protection against AS was possibly associated with a crucial endothelial protective action through lowering the expression of LOX-1 in vascular walls.展开更多
INTRODUCTIONCancer cells,which proliferate rapidly need largeamounts of cholesterol for new membrane synthesis,and high LDL receptor (LDLR) activity.LDL hasbeen proposed as a useful discriminatory vehicle forthe deliv...INTRODUCTIONCancer cells,which proliferate rapidly need largeamounts of cholesterol for new membrane synthesis,and high LDL receptor (LDLR) activity.LDL hasbeen proposed as a useful discriminatory vehicle forthe delivery of cytotoxic drugs to tumor cells.LDL presents many advantages as drug展开更多
The role of very low density lipoprotein receptor (LVLDR) in the process of foam cell formation was investigated. After the primary cultured mouse peritoneal macrophages were incubated with VLDL, β VLDL or low densi...The role of very low density lipoprotein receptor (LVLDR) in the process of foam cell formation was investigated. After the primary cultured mouse peritoneal macrophages were incubated with VLDL, β VLDL or low density lipoprotein (LDL), respectively for 24 h and 48 h, foam cells formation was identified by oil red O staining and cellular contents of triglyceride (TG) and total cholesterol (TC) were determined. The mRNA levels of LDLR, LDLR related protein (LRP) and VLDLR were detected by semi quantitative RT PCR. The results demonstrated that VLDL, β VLDL and LDL could increase the contents of TG and TC in macrophages. Cells treated with VLDL or β VLDL showed markedly increased expression of VLDLR and decreased expression of LDLR, whereas LRP was up regulated slightly. For identifying the effect of VLDL receptor on cellular lipid accumulation, ldl A7 VR cells, which expresses VLDLR and trace amount of LRP without functional LDLR, was used to incubate with lipoproteins for further examination. The results elucidated that the uptake of triglyceride rich lipoprotein mediated by VLDLR plays an important role in accumulation of lipid and the formation of foam cells.展开更多
This study examined the effect of insulin on the expression of very low density lipoprotein receptor (VLDLR) subtypes of SGC7901 cells and discussed its biological implication.In vitro, moderately or poorly-differenti...This study examined the effect of insulin on the expression of very low density lipoprotein receptor (VLDLR) subtypes of SGC7901 cells and discussed its biological implication.In vitro, moderately or poorly-differentiated human gastric adenocarcinoma cell line SGC7901 was incubated with insulin for different lengths of time, and then the expression of protein and RNA level in VLDLR subtypes were detected by Western blotting and real-time PCR, respectively.The results showed that, at certain time interval, insulin could down-regulate expression of type Ⅰ VLDLR and up-regulate the expression of type Ⅱ VLDLR in SGC7901 cells, at both protein and RNA level.We are led to conclude that insulin serves as a regulator in maintaining the balance between glucose and lipid metabolism in vivo, possibly through its effect on the differential expression of VLDLR subtypes.展开更多
By means of radioligand binding assay, both receptors of the malondialdehyde modified low density lipoprotein (MDA-LDL) and the oxidatively modified LDL(o-LDL) on the mouse's peritoneal macrophage (MPM) were studi...By means of radioligand binding assay, both receptors of the malondialdehyde modified low density lipoprotein (MDA-LDL) and the oxidatively modified LDL(o-LDL) on the mouse's peritoneal macrophage (MPM) were studied. The results show that there were high affinity receptors for MDA-LDL and o-LDL on the MPM and both receptors had multiplicity of configuration based on the competitive-inhibition curve or parameters IC50 and Ki, and the acetylated LDL (Ac-LDL) and dextran sulfate can both competitively inhibit MDA-LDL or oLDL binding to these receptors in some degree.It is meanful to study the scavenger receptor multiplicity and its relationship to the genesis, protection and treamtent of atherosclerosis.展开更多
AIM: To investigated the status of low-density lipoprotein (LDL)-receptor and angiotensionogen gene expression in rats treated chronically with ethanol followed by binge administration, a model that mimics the human s...AIM: To investigated the status of low-density lipoprotein (LDL)-receptor and angiotensionogen gene expression in rats treated chronically with ethanol followed by binge administration, a model that mimics the human scenario. METHODS: Rats were chronically treated with ethanol in liquid diet for 4 wk followed by a single binge mode of ethanol administration (5 mg/kg body weight). Samples were processed 4 h after binge ethanol administration (chronic ethanol binge). Control rats were fed isocaloric diet. In the control for binge, ethanol was replaced by water. Expression of mRNA for angioten-sinogen, c-fos and LDL-receptor, and nuclear accumulation of phospho-extracellular regulated kinases (ERK)1/2 and ERK1/2 protein were examined. RESULTS: Binge ethanol administration in chronically treated rats caused increase in steatosis and necrosis. Chronic ethanol alone had negligible effect on mRNA levels of LDL-receptor, or on the levels of nuclear ERK1/2 and phospho-ERK1/2. But, chronic ethanol followed by binge caused a decrease in LDL-receptor mRNA, and also decreased the levels of ERK1/2 and phospho-ERK1/2 in the nuclear compartment. On the other hand, chronic ethanol-binge increased mRNA expression of angiotensinogen and c-fos. CONCLUSION: Binge ethanol after chronic exposure, causes transcriptional dysregulation of LDL-receptor and angiotensinogen genes, both cardiovascular risk factors.展开更多
基金D.W.Z.is a Scholar of the Alberta Heritage Foundation for Medical Research and is supported in part by a Canadian Institutes of Health Research New Investigator AwardZhang laboratory is supported by Canadian Foundation for Innovation,grants from a Grant-in-Aidfor Heart and Stroke Foundation of CanadaPfizer Canada, the Canadian Institutes of Health Research(MOP 93794), and Mazankowski Alberta Heart Institute
文摘Atherosclerotic cardiovascular disease is the main cause of mortality and morbidity in the world. Plasma levels of low density lipoprotein cholesterol (LDL-C) are positively correlated with the risk of atherosclerosis. High plasma LDL concentrations in patients with hypercholesterolemia lead to build-up of LDL in the inner walls of the arteries, which becomes oxidized and promotes the formation of foam cells, consequently initiating atherosclerosis. Plasma LDL is mainly cleared through the LDL receptor (LDLR) pathway. Mutations in the LDLR cause familiar hyperch- olesterolemia and increase the risk of premature coronary heart disease. The expression of LDLR is regulated at the transcriptional level via the sterol regulatory element binding protein 2 (SREBP-2) and at the posttranslational levels mainly through proprotein convertase subtilisin/kexin-type 9 (PCSK9) and inducible degrader of the LDLR (IDOL). In this review, we summarize the latest advances in the studies of PCSK9.
文摘Objective: To investigate the molecular mechanisms and effective target ponits of lipid-lowering drug, Rhizoma Curcumae Longae, and study the effect of curcumin on the expression of low density lipoprotein (LDL) receptors in macrophages in mice. Methods. Macrophages in mice were treated with curcumin, which was purified from the ethanolly extraction of Rhizoma Curcumae Longae for 24 h. The LDL receptors expressed in the macrophages were determined by enzyme-linked immunosorbent assay (ELISA) and assay of Dil labeled LDL uptake by flow cytometer. Results: It was found for the first time that 10 μmol/L-50 μmol/L curcumin could obviously up-regulate the expression of LDL receptor in macrophages in mice, and a dose-effect relationship was demonstrated. Conclusion: One of the lipid-lowering mechanisms of traditional Chinese medicine, Rhizoma Curcumae Longae, was completed by the effect of curcumin through the up-regulation of the expression of LDL receptor.
基金This project was supported by a grant from National Natu-ral Sciences Foundation of China (No .30300134)
文摘To explore the functions of very low density lipoprotein receptor (VLDL-R) subtype II in lipoprotein metabolism and foam cells formation, the recombinant plasmid with the two subtypes cDNA was constructed respectively, the ldl-A7 cell lines were transfected and two cell lines expressing VLDL-R were obtained: one stably expressing the VLDLR with the O-linked sugar region (type I VLDLR) and the other without the O-linked sugar region (type II VLDLR). In the study on binding of VLDLR to their nuclein labeled natural ligands (VLDL and β-VLDL), it was found that surface binding of 125I-VLDL or 125I-β-VLDL of ldl-A7 cells transfected with type I VLDLR recombinant (ldl-A7-VRI) was more higher than that of ldl-A7 cells transfected with type II VLDLR recombinant (ldl-A7-VRII). After being incubated with VLDL for different time, the contents of triglyceride and total cholesterol in cells were mensurated, and the formation of foam cells and accumulation of lipid in cells was observed by oil-red O staining. The results showed that the contents of triglyceride and total cholesterol in ldl-A7-VR I were much higher than those in ldl-A7-VR II, and ldl-A7-VR I could transform into foam cells notably. It was suggested that type I VLDLR binds with relative higher affinity to VLDL and β-VLDL, and internalizes much more lipoprotein into cells. As a result, we can conclude that type I VLDLR plays a more important role in lipoprotein metabolism and foam cells formation than type II VLDLR.
基金the National Natural Science Foundation of China(81372872 to J.Yang,81402215 to X.Du,and 81320108022 to K.Chen)funds from the University Cancer Foundation via the Sister Institution Network Fund at the Tianjin Medical University Cancer Institute and Hospital,Fudan University Shanghai Cancer Center,and University of Texas MD Anderson Cancer Centersupported by the program for Innovative Research Team in University in China(IRT1076 to K.Chen)
文摘Low-density lipoprotein receptor-related protein 1(LRP1,also known as CD91),a multifunctional endocytic and cell signaling receptor,is widely expressed on the surface of multiple cell types such as hepatocytes,fibroblasts,neurons,astrocytes,macrophages,smooth muscle cells,and malignant cells.Emerging in vitro and in vivo evidence demonstrates that LRP1 is critically involved in many processes that drive tumorigenesis and tumor progression.For example,LRP1 not only promotes tumor cell migration and invasion by regulating matrix metalloproteinase(MMP)-2and MMP-9 expression and functions but also inhibits cell apoptosis by regulating the insulin receptor,the serine/threonine protein kinase signaling pathway,and the expression of Caspase-3.LRPI-mediated phosphorylation of the extracellular signal-regulated kinase pathway and c-jun N-terminal kinase are also involved in tumor cell proliferation and invasion.In addition,LRP1 has been shown to be down-regulated by microRNA-205 and methylation of LRP1CpG islands.Furthermore,a novel fusion gene,LRP1-SNRNP25,promotes osteosarcoma cell invasion and migration.Only by understanding the mechanisms of these effects can we develop novel diagnostic and therapeutic strategies for cancers mediated by LRP1.
基金supported by the National Natural Science Foundation of China(No.81072359)Natural Science Foundation of Guangdong Province(No.S2013010016791)+1 种基金Science and Technology Development Foundation of Shenzhen(No.JCYJ20120613112221107 and JCYJ20130326110246234)Natural Science Foundation of Shenzhen University(No.801-00035911)
文摘Objective To investigate the association between low-density lipoprotein receptor-related protein 5 (LRPS) variants (rs12363572 and rs4930588) and type 2 diabetes mellitus (T2DM) in Han Chinese. Methods A total of 1842 T2DM cases (507 newly diagnosed cases and 1335 previously diagnosed cases) and 7777 controls were included in this case-control study. PCR-RFLP was conducted to detect the genotype of the two single nucleotide polymorphisms (SNPs). Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated to describe the strength of the association by logistic regression. Results In the study subjects, neither rs12363572 nor rs4930588 was significantly associated with T2DM, even after adjusting for relevant covariates. When stratified by body mass index (BMI), the two SNPs were also not associated with T2DM. Among the 3 common haplotypes, only haplotype ~ was associated with reduced risk of T2DM (OR 0.820, 95% CI 0.732-0.919). In addition, rs12363572 was associated with BMI (P〈0.001) and rs4930588 was associated with triglyceride levels (P=0.043) in 507 newly diagnosed T2DM cases but not in healthy controls. Conclusion No LRP5 variant was found to be associated with T2DM in Han Chinese, but haplotype TT was found to be associated with T2DM.
文摘Objectives Bai Ku Yao(White-trousers Yaos)is a special branch of Yao minority in China.They are now living in both Lihu and Baxu villages,Nandan County, Guangxi,China.The population size is about 30,000.The special customs and culture of Bai Ku Yao,including their special clothing,intra-ethnic marriages and alcohol intake are still completely conserved to the present day.In previous epidemiologic studies,we found that the serum lipid levels and the prevalence of hyperlipidaemia were lower in Bai Ku Yao than in Han Chinese from the same region.This ethnic difference in serum lipid profiles is still not well known.We hypothesized that there may be significant differences in some genetic polymorphismsssociation of low density lipoprotein receptor (LDL-R) genepolymorphism and several environmental factors with serum lipid levels in the Guangxi Bai Ku Yao and Han populations.Methods A total of 1024 subjects of Bai Ku Yao and 792 participants of Han Chinese were stud- ied by a stratified randomized cluster sampling.Epidemiological survey was carried out using internationally standardized methods.Information on demographics,socioeconomic status, and lifestyle factors was collected with standardized questionnaires. The height,weight,waist circumference,blood pressure, and serum total cholesterol(TC),triglyceride(TG), high-density lipoprotein cholesterol(HDL-C),low-density lipoprotein cholesterol(LDL-C),apolipoprotein(Apo) A1, and ApoB were measured.Body massindex(BMI,kg/m2) was calculated.Genotyping of the LDL-RAvaⅡwas performed by polymerse chain reaction and restriction fragment length polymorphism combined with gel electrophoresis,and then confirmed by direct sequencing.Results(l)The height,weight,serum TC,HDL-C,LDL-C,ApoAl levels and the ratio of ApoAl to ApoB were lower in Bai Ku Yao than in Han Chinese(P【0.01 for all),whereas the percentage of subjects who consumed alcohol or smoked cigarettes was higher in Bai Ku Yao than in Han Chinese(P【0.01 for each).(2) The frequency of A+ allele in Bai Ku Yao was 34.5%,and the frequencies of A-A-,A-A+ and A+A + genotypes were 42.6%,45.9%and 11.5%;respectively. The frequency of A+ allele in Han Chinese was 19.3%(P【0.001),and the frequencies of A-A-,A-A + and A+A+ genotypes were 64.9%,31.6%and 3.5%(P【0.001);respectively. The frequencies of A-A-,A-A+ and A+A+ genotypes in Bai Ku Yao were significant difference between males and females,between normal TC and high TC subgroup, and between normal LDL-C and high LDL-C subgroup (P【0.05 for all),whereas the frequencies of A- and A+ ? alleles in Han Chinese were significant difference between males and females(P【0.05).(3) Serum LDL-C levels in Bai Ku Yao were significant difference among the A-A-, A-A+ and A+A+ genotypes(P【0.05),the A+ carriers had higher serum LDL-C levels.Serum HDL-C levels in Han Chiese were significant difference among the A-A-,A-A + and A+A+ genotypes(P【0.01),the A+ carriers had higher serum HDL-C levels.(4) After adjusting other factors,the prevalence of LDL-C abnormality was still higher in Han Chiese than in Bai Ku Yao.The prevalence of TC abnormality in Han Chinese was almost twice high as in Bai Ku Yao. The age and diet were common risk factor for TC abnormality. No effect of AvaⅡgenotype or alcohol consumption on the TC abnormality was found,but the combination of geno-type and alcohol consumption can increase the prevalence of TC abnormality[Exp(B) =(1.154)].Age was negatively cor- related with TG level.Conclusions Serum TC and LDL-C levels were lower in Bai Ku Yao than in Han Chinese.There were significant differences in the AvaⅡallele and genotype frequencies between the he A+ carriers in Bai Ku Yao had higher serum LDL-C levels,whereas the A+ carriers in Han had higher serum HDL-C levels.Interactions between alcohol consumption or cigarette smoking and the LDL-R AvaⅡgenotype were also observed.The differences in the serum lipid profiles between the two ethnic groups might partly result from different genotypic frequency of LDL-R AvaⅡpolymorphism or differentgene-enviromental interactions.Bai Ku Yao and Han population,the frequency of A + allele was higher in Bai Ku Yao than in Han.T between the two ethnic groups.Therefore,the aim of the present study was to detect the
基金Supported bythe State Natural Science Foundation of China(No .30371496) .
文摘Objective.- To investigate the prevention by Tongxinluo capsule (通心络胶囊, TXL) of vascular lesions and its effect on the levels of protein and gene expression of lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) of vascular wall in rabbits with atherosclerosis (AS), and to explore its possible mechanism against AS. Methods: AS models were established by feeding New Zealand white rabbits with high-cholesterol diet, and 24 immature rabbits were randomly divided into the control group, model group and treated group (treated with TXL capsule). The indexes of total cholesterol (TO) and low density lipoprotein (LDL) levels were measured at the 16th week. The intima thickness and the plaque area of abdominal aorta were quantitatively analyzed by pathological morphological analysis, the expression of macrophage and smooth muscle cell (SMC) in intima were detected by immunohistochemical method and histologic segments were stained by Hematoxilin-Eosin (HE) to identify the degree of atherosclerotic lesion in the model group and the prevention by TXL. The LOX-1 gene and protein expression in abdominal aorta was detected by semi-quantitative RT-PCR and immunohistochemistry, respectively. Results: In the model group, the levels of TC and LDL were significantly elevated, aortic intima thickened extensively, the intima area enhanced, and macrophages expression increased; the levels of LOX-1 gene and protein expression was up-regulated in endothelium and neo-intima of the abdominal aorta. The treatment with TXL reduced blood lipids, attenuated arterial intimal proliferation, markedly inhibited the expression of macrophage and excessively expressed the level of LOX-1. Conclusion:TXL has an inhibitory effect on blood lipids, and it can prevent the occurrence of vascular lesion and cure its development, and its protection against AS was possibly associated with a crucial endothelial protective action through lowering the expression of LOX-1 in vascular walls.
基金the Scientific Foundation of Shandong Provincial Scientific & Technical Commission,No.971164607.
文摘INTRODUCTIONCancer cells,which proliferate rapidly need largeamounts of cholesterol for new membrane synthesis,and high LDL receptor (LDLR) activity.LDL hasbeen proposed as a useful discriminatory vehicle forthe delivery of cytotoxic drugs to tumor cells.LDL presents many advantages as drug
文摘The role of very low density lipoprotein receptor (LVLDR) in the process of foam cell formation was investigated. After the primary cultured mouse peritoneal macrophages were incubated with VLDL, β VLDL or low density lipoprotein (LDL), respectively for 24 h and 48 h, foam cells formation was identified by oil red O staining and cellular contents of triglyceride (TG) and total cholesterol (TC) were determined. The mRNA levels of LDLR, LDLR related protein (LRP) and VLDLR were detected by semi quantitative RT PCR. The results demonstrated that VLDL, β VLDL and LDL could increase the contents of TG and TC in macrophages. Cells treated with VLDL or β VLDL showed markedly increased expression of VLDLR and decreased expression of LDLR, whereas LRP was up regulated slightly. For identifying the effect of VLDL receptor on cellular lipid accumulation, ldl A7 VR cells, which expresses VLDLR and trace amount of LRP without functional LDLR, was used to incubate with lipoproteins for further examination. The results elucidated that the uptake of triglyceride rich lipoprotein mediated by VLDLR plays an important role in accumulation of lipid and the formation of foam cells.
基金supported by grants from National Natural Sciences Foundation of China (No.39970307)Hubei Provincial Natural Sciences Foundation of China (No.2005ABA092)
文摘This study examined the effect of insulin on the expression of very low density lipoprotein receptor (VLDLR) subtypes of SGC7901 cells and discussed its biological implication.In vitro, moderately or poorly-differentiated human gastric adenocarcinoma cell line SGC7901 was incubated with insulin for different lengths of time, and then the expression of protein and RNA level in VLDLR subtypes were detected by Western blotting and real-time PCR, respectively.The results showed that, at certain time interval, insulin could down-regulate expression of type Ⅰ VLDLR and up-regulate the expression of type Ⅱ VLDLR in SGC7901 cells, at both protein and RNA level.We are led to conclude that insulin serves as a regulator in maintaining the balance between glucose and lipid metabolism in vivo, possibly through its effect on the differential expression of VLDLR subtypes.
文摘By means of radioligand binding assay, both receptors of the malondialdehyde modified low density lipoprotein (MDA-LDL) and the oxidatively modified LDL(o-LDL) on the mouse's peritoneal macrophage (MPM) were studied. The results show that there were high affinity receptors for MDA-LDL and o-LDL on the MPM and both receptors had multiplicity of configuration based on the competitive-inhibition curve or parameters IC50 and Ki, and the acetylated LDL (Ac-LDL) and dextran sulfate can both competitively inhibit MDA-LDL or oLDL binding to these receptors in some degree.It is meanful to study the scavenger receptor multiplicity and its relationship to the genesis, protection and treamtent of atherosclerosis.
文摘AIM: To investigated the status of low-density lipoprotein (LDL)-receptor and angiotensionogen gene expression in rats treated chronically with ethanol followed by binge administration, a model that mimics the human scenario. METHODS: Rats were chronically treated with ethanol in liquid diet for 4 wk followed by a single binge mode of ethanol administration (5 mg/kg body weight). Samples were processed 4 h after binge ethanol administration (chronic ethanol binge). Control rats were fed isocaloric diet. In the control for binge, ethanol was replaced by water. Expression of mRNA for angioten-sinogen, c-fos and LDL-receptor, and nuclear accumulation of phospho-extracellular regulated kinases (ERK)1/2 and ERK1/2 protein were examined. RESULTS: Binge ethanol administration in chronically treated rats caused increase in steatosis and necrosis. Chronic ethanol alone had negligible effect on mRNA levels of LDL-receptor, or on the levels of nuclear ERK1/2 and phospho-ERK1/2. But, chronic ethanol followed by binge caused a decrease in LDL-receptor mRNA, and also decreased the levels of ERK1/2 and phospho-ERK1/2 in the nuclear compartment. On the other hand, chronic ethanol-binge increased mRNA expression of angiotensinogen and c-fos. CONCLUSION: Binge ethanol after chronic exposure, causes transcriptional dysregulation of LDL-receptor and angiotensinogen genes, both cardiovascular risk factors.