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1.
Proteinase inhibitors have been implicated in brain development and in degenerative processes such as Alzheimer's disease. Low-density lipoprotein receptor-related protein (LRP) is a multifunctional cell-surface receptor that binds activated forms of the proteinase inhibitor, alpha 2-macroglobulin (alpha 2M) and apolipoprotein E. Solubilized plasma membranes of human cerebral cortical gray matter were subjected to affinity chromatography on alpha 2M-methylamine-sepharose. A single receptor was purified; this protein was LRP as determined by molecular mass, peptide structure, and immunoreactivity with monoclonal and polyclonal antibodies. In adult human brain, LRP immunoreactivity was abundant on neuronal cell bodies and proximal processes. Other cells within the neuropil, including glia and microvascular cells (endothelium and pericytes), were immunonegative. Weak LRP immunoreactivity was identified in a perivascular pattern corresponding to the location of astrocytic foot processes. The distribution of LRP in the central nervous system is consistent with the potential function of this receptor in the regulation of proteinase activity, cytokine activity, and cholesterol metabolism.  相似文献   

2.
2-Macroglobulin (2M) as well as its receptor, the low-density lipoprotein receptor-related (LRP) and the receptor-associated protein (RAP) are involved in the clearance of cerebral Aβ. Current evidence suggests that polymorphisms in the genes of 2M, LRP and RAP may have functional effects on the proteins. Two independent association samples of 271 AD patients and 280 representative controls were investigated whether the risk for developing AD is altered in carriers of polymorphisms in the 2M-gene (Va1000Ile), in the LRP-gene (Ala216Val) and in the RAP-gene (Val311Met). Genotypes were determined by standard PCR and restriction fragment length polymorphism. The results were adjusted for age, gender and apolipoprotein E-4 (APOE) polymorphism. Inheritance of 2M conferred a small increased risk for sporadic AD with an estimated Mantel–Haenszel odds ratio of 1.47. There was no age- or gender-dependent increase in 2M Val1000Ile allele frequencies in AD patients compared to controls. There was no significant difference in the allele frequencies among control and AD subjects for the LRP and RAP polymorphisms. We found no evidence of an interaction between the 2M and RAP or LRP with regard to conferred risk. Our data suggest that the 2M Val1000Ile polymorphism is weakly associated with AD. Although LRP as well as RAP seem to play an essential role in the metabolism of 2M and APOE, there is no increase in the genetic risk for AD in patients carrying the investigated polymorphisms.  相似文献   

3.
目的:探讨低密度脂蛋白受体相关蛋白在肾间质纤维化中的表达变化及意义。方法:雄性Wistar大鼠随机分为假手术组,模型3、6、9、12d组和血管紧张素转换酶抑制剂(依那普利)治疗9d组。Masson染色结合半定量评分测小管-间质损伤指数,免疫组化确定低密度脂蛋白受体相关蛋白在肾脏的表达部位;蛋白印迹分析检测肾组织内结缔组织生长因子,低密度脂蛋白受体相关蛋白水平。结果:低密度脂蛋白受体相关蛋白阳性表达主要在肾间质和肾小球系膜区中,在单侧输尿管梗阻模型中随观察时间延长逐渐增加,于第9d达高峰;并且第9d依那普利治疗组大鼠肾内低密度脂蛋白受体相关蛋白水平显著少于模型组(P<0.01);相关分析显示,在模型组中低密度脂蛋白受体相关蛋白和结缔组织生长因子蛋白水平呈正相关(r=0.786,P<0.01);低密度脂蛋白受体相关蛋白水平与肾小管间质损伤指数呈正相关(r=0.800,P<0.01)。结论:低密度脂蛋白受体相关蛋白作为结缔组织生长因子的受体蛋白,在大鼠肾间质纤维化模型中表达增加,可能参与肾间质纤维化过程。  相似文献   

4.
BACKGROUND: Tumor necrosis factor α, as a pathogenic factor, induces the inflammatory reaction mainly via the activation of the nuclear factor kappa B signaling pathway. Low density lipoprotein receptor-related protein 1 (LRP1) is involved in the regulation of the inflammatory reaction induced by cytokines.  相似文献   

5.
In this study, we examined protein–protein interactions between two neuronal receptors, low density lipoprotein receptor-related protein (LRP) and sorLA/LR11, and found that these receptors interact, as indicated by three independent lines of evidence: co-immunoprecipitation experiments on mouse brain extracts and mouse neuronal cells, surface plasmon resonance analysis with purified human LRP and sorLA, and fluorescence lifetime imaging microscopy (FLIM) on rat primary cortical neurons. Immunocytochemistry experiments revealed widespread co-localization of LRP and sorLA within perinuclear compartments of rat primary neurons, while FLIM analysis showed that LRP-sorLA interactions take place within a subset of these compartments.  相似文献   

6.
DNA samples from 70 unrelated UK patients with heterozygous familial hypercholesterolaemia were screened by Southern blot hybridisation with a 5' fragment of the human low density lipoprotein (LDL) receptor cDNA. In the majority of cases, the restriction fragment pattern of the LDL receptor gene was indistinguishable from that observed in normal subjects. However, three patients were found to have a deletion of approximately 1 kb in the central portion of the gene. Mapping experiments indicated that in two patients a similar deletion has occurred that includes all or part of exon 5, and in the third patient a deletion has occurred that includes exon 7. Taking into account our previously described patient with a deletion in the 3' part of the gene, this means that in four out of 70 UK patients with familial hypercholesterolaemia (6%), the defect is caused by a detectable deletion of part of the coding portion of the low density lipoprotein receptor gene.  相似文献   

7.
The expression of very low density lipoprotein (VLDL) receptor mRNA in atherosclerotic lesions in rabbits was investigated. To examine the expression of the VLDL receptor in the vascular wall, poly(A)+ RNA was isolated from whole aortas of cholesterol-fed New Zealand White (NZW), Watanabe heritable hyperlipidemic (WHHL), and normal NZW rabbits, and then Northern blot analysis was performed. The VLDL receptor mRNA was detected in aortas from both NZW rabbits fed 0.5% cholesterol for 16 weeks and 12-month-old WHHL rabbits, whereas no expression was seen in normal NZW rabbit aortas. To further determine the localization of the VLDL receptor mRNA, in situ hybridization using digoxigenin-labeled riboprobes and immunohistochemistry using monoclonal antibodies against each cell component were performed. Early atherosclerotic lesions, termed fatty streaks, in the NZW rabbits fed 0.5% cholesterol for 4 weeks demonstrated strong expression of the VLDL receptor mRNA by macrophages. The VLDL receptor mRNA was also expressed in more advanced atherosclerotic lesions from both atherogenic animal models. The predominant origin of the VLDL receptor mRNA-positive cells was macrophages, and some intimal smooth muscle cells appeared to express a weak but significant signal in these advanced lesions. Our findings suggest that the VLDL receptor expression may play a role in the development of atherosclerosis.  相似文献   

8.
The low density lipoprotein receptor-related protein 1 (LRP1 gene) is a candidate gene for Alzheimer's disease (AD), because it is a ligand for proteins involved in AD pathogenesis, such as apolipoprotein E (APOE), alpha2-macroglobulin (A2M), amyloid precursor protein (APP), and is located on chromosome 12, within a region linked with AD. An association between a silent polymorphism (C/T) in exon 3 and late onset AD has been reported, with an increased frequency of the C allele, although with conflicting results. We examined this polymorphism in a cohort of 166 sporadic AD patients and 225 sex- and age-matched nondemented controls from Southern Italy. No statistically significant differences were found in LRP1 genotype and allele frequencies between the whole AD sample and controls, nor in early- and late-onset subsets of AD patients. No statistically significant differences in frequencies between LRP1 alleles and AD among APOE allele, age, or gender strata were found. Finally, comparing our results with the findings from other European populations, the LRP1 C allele frequency showed a statistically significant decreasing trend from Northern to Southern regions of Europe, with a concomitant increase in LRP1 T allele frequency, but in AD patients only. Finally, in the AD sample, a decreasing geographical trend from North to South of Europe was found for LRP1 CC genotype, and an inverse trend for LRP1 CT genotype frequency. We suggest that these regional variations in LRP1 genotype and allele frequencies in AD could be related to the different patterns of association between this polymorphism and the disease in various European studies.  相似文献   

9.
目的 探讨新疆地区维吾尔族、汉族低密度脂蛋白受体相关蛋白基因(low density lipoproteinreceptor-related protein gene,LRP)766C/T多态性与阿尔茨海默病(Alzheimer's disease AD)的关系.方法 对新疆地区维吾尔族、汉族≥50岁8284名人群进行AD流行病学调查,参照ADRDA-NINCDS的标准,选取AD患者209例与正常对照220名,应用聚合酶链反应-限制性片段长度多态技术检测LRP基因766C/T多态性,采用病例-对照的关联分析方法进行基因型和等位基因频率分析.结果 (1)新疆维吾尔族、汉族之间LRP基因的基因型和等位基因分布频率差异有统计学意义(P<0.05).(2)汉族病例组与对照组间基因型和等位基因频率分布差异有统计学意义(P<0.05).(3)在年龄≥65岁的病例组与对照组间基因型和等位基因频率分布差异有统计学意义(P<0.05),且此年龄组携带C等位基因的个体发生AD的危险性显著增加(OR=1.98,P<0.05).(4)在女性病例组中C/C基因型分布频率和C等位基因频率显著高于对照组(P<0.05),女性携带C等位基因的个体发生AD的危险性显著增加(OR=2.927,P<0.05).结论 新疆维吾尔族和汉族之间LRP,基因766C/T多态性存在差异,并发现在汉族、年龄≥65岁及女性人群中LRP基因766C/T多态性与AD的发病风险存在关联.  相似文献   

10.
11.
The recently cloned very low density lipoprotein (VLDL) receptor binds triglyceride-rich, apolipoprotein-E-containing lipoproteins with high affinity. The observation that VLDL receptor mRNA is abundantly expressed in extracts of tissues such as skeletal muscle and heart, but not liver, has led to the hypothesis that this receptor may facilitate the peripheral uptake of triglyceride-rich lipoproteins. However, little information is available concerning the types of cells that express this receptor in vivo. As expression of the VLDL receptor in the vascular wall might have important implications for the uptake and transport of triglyceride-rich lipoproteins, and perhaps facilitate the development of atherosclerosis in hypertriglyceridemic individuals, we used in situ hybridization and immunohistochemistry to determine whether VLDL receptor mRNA and protein was expressed in human vascular tissue. We observed expression of the receptor by both endothelial and smooth muscle cells within normal arteries and veins, as well as within atherosclerotic plaques. In the latter, the VLDL receptor was also expressed by macrophage-derived foam cells. The widespread distribution of the VLDL receptor in vascular tissue suggests a potentially important role for this receptor in normal and pathophysiological vascular processes.  相似文献   

12.
低密度脂蛋白受体相关蛋白5基因的基因组结构   总被引:3,自引:0,他引:3  
目的 确定2低密度脂蛋白受体相关蛋白5(low density lipoprotein receptor related protein,5 LRP5)的基因组结构。方法 以LRP5基因的cDNA序列为线索,采用计算机杂交方法首先通过对比分析该基因的cDNA序列和基因组序列,初步确定LRP5基因的基因组结构,按分析得到的基因组结构设计引物,扩增并测定外显子序列和外显子内含子接头序列,确定该基因的基因组结构。结果 LRP5基因的基因组DNA全长为131.6kb,含4有23个外显子和22个内含子;在编码序列中检测到3个单核苷酸多态,即位于第2外显子的A459G,位于第10外显子的C2220T和位于第21外显子的G4416C;LRP5基因含有4个已知的短串联重复序列,即D11S1917,D11S4087,D11S1337和D11S4178,它们分别位于该基因的5'端和第1,4,13内含子内。结论 LRP5基因的基因组结构的确定,为分析该基因突变和功能研究奠定了基础。  相似文献   

13.
We recently suggested that soluble beta-amyloid (betaA4) is a ligand of the low density lipoprotein receptor-related protein and heparan sulfate proteoglycan pathway. In the blood and in the cerebrospinal fluid, betaA4 is bound to apolipoprotein E containing lipoproteins. We examined how binding of betaA4 to beta-very low density lipoproteins (betaVLDL) alters their cellular metabolism. Compared with betaVLDL alone, complexes of betaVLDL and betaA4 were internalized, but not degraded at increased rates in fibroblasts and in rat hippocampal cells. The uptake of complexes of betaVLDL and betaA4 was not mediated by the low density lipoprotein receptor. BetaA4 not complexed to betaVLDL competed with the endocytosis of alpha2-macroglobulin and apolipoprotein E-enriched betaVLDL. The uptake of complexes of betaVLDL and betaA4 was inhibited by heparin, suramin, lactoferrin, the 39-kd receptor-associated protein, and alpha2-macroglobulin. Complexes of betaVLDL and betaA4 were taken up at reduced rates in Chinese hamster ovary cells partially (pgsB-650) or completely lacking (pgsA-745) proteoglycans. BetaA4 in which the positively charged amino acids between positions 13 and 17 (HHQKL) were replaced by glycine (GGQGL) failed to enhance the uptake of betaVLDL. Together, the data suggest that binding of betaA4 to betaVLDL produces particles that are endocytosed by low density lipoprotein receptor-related protein and HSPG. Complexes of betaVLDL and betaA4 had an intracellular half-life 4-fold that of native betaVLDL, did not undergo lysosomal degradation, and were resecreted into the culture medium. These findings represent the first identification of an endocytotic pathway for betaA4 and may be of relevance to the pathobiochemistry of neurodegenerative disorders.  相似文献   

14.
Genetics of the low density lipoprotein receptor:   总被引:1,自引:0,他引:1  
Six indices of low density lipoprotein (LDL) receptor activity were assayed in cultured fibroblasts from seven subjects with familial hypercholesterolemia (HC) and six subjects without HC (non-HCs). Four non-HCs, three HC heterozygotes and one HC homozygous proband belonged to one kindred (kindred A). The proband's fibroblast 125I-LDL processing values fell within or were slightly above the range defined by fibroblasts from three "receptor-negative" HC homozygotes. Thus, the plasma membrane receptor defect in this kindred is probably of the "receptor-negative" category. LDL receptor-dependent 125I-LDL processing was about twice as high in fibroblasts from non-HCs as in those from HC heterozygotes belonging to kindred A. The segregation pattern of LDL receptor activity in this kindred was compatible with control by a single gene locus. 125I-LDL processing values from non-HCs, HC heterozygotes and HC homozygotes differed significantly from one another, but non-HCs and HC heterozygotes showed some overlap. LDL receptor-dependent 125I-LDL association (plasma membrane binding plus intracellular accumulation) data for 6 HC heterozygous and 13 non-HC fibroblast strains clustered into two and into three groups, respectively. Median 125I-LDL association levels in these groups appeared to be in agreement with hypothesis that two different geno-types in HC heterozygotes and three in non-HCs determined LDL receptor activity. These findings suggest the possibility that 125I-LDL processing studies may reveal "normal" alleles at the LDL receptor locus.  相似文献   

15.
Fibroblast low density lipoprotein (LDL) plasma membrane receptor activity, measured as 125I-LDL association (plasma membrane binding plus intracellular accumulation) and degradation was determined in cell strains from 14 monozygotic (MZ) and 21 like-sexed dizygotic (DZ) normolipidemic twin pairs. The twins were between 57 and 62 years old and had liver apart for an average of 38 years (range 0-60). The intrapair differences were significantly smaller in MZ than in DZ twin pairs in fibroblast 125I-LDL association as well as degradation assays (P less than 0.05). These findings suggest a genetic influence on normal variation in LDL receptor activity in vitro. In two MZ pairs discordant for psoriasis, the psoriatic twin had markedly lower LDL receptor activity than the cotwin.  相似文献   

16.
倪杰  房宇  胡燕  董玉林 《解剖学报》2016,47(6):744-749
目的探讨细叶远志皂苷(TEN)对阿尔茨海默病(AD)大鼠海马低密度脂蛋白受体相关蛋白1(LRP1)水平的影响。方法 60只SD大鼠随机分组,采用脑立体定位技术将β-淀粉样蛋白(Aβ)1~40注入大鼠右侧海马CA1区制备AD模型并给予细叶远志皂苷治疗4周。术后分别采用Morris水迷宫、Real-time PCR和Western blotting检测大鼠学习记忆能力及海马内LRP1 mRNA及蛋白的表达变化,并行免疫荧光检测海马区LRP1阳性神经元的变化。结果 1.Morris水迷宫:模型组大鼠学习记忆能力较正常组相比明显降低(P0.01),经TEN灌胃治疗后,TEN各剂量组逃逸潜伏期均不同程度缩短、游泳路程缩小、穿越虚拟平台次数增加,中、高剂量组差异具有统计学意义(P0.05,P0.01);2.Real-time PCR和Western blotting:模型组LRP1mRNA和蛋白的相对表达量均明显低于正常对照组(P0.01),给予TEN治疗后,治疗组LRP1mRNA和蛋白相对表达量随着TEN给药剂量的增加逐步升高,低剂量组差异不明显(P0.05),中、高剂量组与模型组之间的差异有统计学意义(P0.01);3.免疫荧光检测结果显示,海马区模型组LRP1阳性细胞明显减少,与正常组差异有统计学意义(P0.01);高剂量组LRP1阳性细胞数量增加明显,与正常组差异没有统计学意义(P0.05)。结论细叶远志皂苷可能通过提高脑内LRP1的含量,从而改善Aβ1~40诱导的AD大鼠的学习记忆能力。  相似文献   

17.
BACKGROUND: Emerging evidence demonstrates that low density lipoprotein receptor-related protein 1 (LRP1) is involved in lipid metabolism and regulation of inflammatory reaction. OBJECTIVE:To explore the effect of lentivirus-induced knockdown of low density lipoprotein receptor-related protein 1 on cartilage damage and matrix metalloproteinase 13 in a rat model of osteoarthritis, so as to assess the role of low density lipoprotein receptor-related protein 1 in the pathogenesis of osteoarthritis. METHODS: Sixty-four Sprague-Dawley rats were included and ramdomly divided into four groups (n=16 for each): negative control group, no surgery; sham-surgery group, only the articular cavity of the knee was exposed; osteoarthritis plus shLRP1 group, rat osteoarthritis models were established by cutting anterior cruciate ligament and removing the medial meniscus partly followed by an intra-articular injection of lentivirus-mediated siRNA at 2 days after surgery, once a week for 2 consecutive weeks; osteoarthritis group, an intra-articular injection of the negative control lentivirus was performed after surgery. Rats in the four groups started running on the self-made electric treadmill from 5 days after modeling, 30 minutes per day, totally 500 meters. Cartilage damage and matrix metalloproteinase 13 expression in cartilage tissues were determined at 2, 4, 6 weeks after surgery. RESULTS AND CONCLUSION: Gross and pathological observations showed that lentivirus-induced knockdown of low density lipoprotein receptor-related protein 1 aggravated cartilage damage in the rat model of osteoarthritis. At 6 weeks after surgery, Mankin’s score and matrix metalloproteinase 13 expression in the cartilage tissues in osteoarthritis plus shLRP1 group were significantly increased compared with other three groups (P < 0.05). These findings indicate that a simulation model of osteoarthritis is developed by cutting anterior cruciate ligament and removing the medial meniscus partly combined with running on the treadmill. Lentivirus-induced knockdown of LRP1 aggravates cartilage damage in a rat model of osteoarthritis 中国组织工程研究杂志出版内容重点:组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程  相似文献   

18.
Genetics of the low density lipoprotein receptor:   总被引:1,自引:0,他引:1  
Fibroblast association (plasma membrane binding plus intracellular accumulation) and degradation of radioiodinated low density lipoprotein (125I-LDL) index plasma membrane LDL receptor activity. Cultured fibroblasts from 23 subjects affected with familial hypercholesterolemia (HC) and from 95 subjects without HC (non-HCs) were tested for 125I-LDL association and degradation. Both LDL receptor activity indices were twice as high in non-HC and HC heterozygous cell strains. This is compatible with a major gene effect on LDL receptor activity. However, a considerable overlap between non-HC and HC heterozygous values was found in the 125I-LDL association assay [median (range) 970 (330-2500), and 450 (250-490), respectively] and in the degradation assay [median (range) 810 (280-2020), and 470 (160-790), respectively]. The values are expressed as ng 125I-LDL X mg cell protein-1 X 4.5 h-1. These great overlaps in the LDL receptor activity indices support the view that the influence of LDL receptor activity on the HC phenotype may be smaller than believed previously. Furthermore, for the diagnosis of HC, these LDL receptor activity assays are far more expensive and have less sensitivity and specificity than simple serum cholesterol determination. The LDL receptor-dependent 125I-LDL association values for the HC heterozygous individuals clustered into four groups. Family data supported the hypothesis that this variation could be due to four different LDL receptor variants, each coded for by different alleles at the LDL receptor locus. If confirmed, this finding may have implications for the understanding of the variable expression of HC and also of the genetic impact on lipoprotein metabolism and susceptibility to atherosclerosis in non-HCs.  相似文献   

19.
High levels of small low density lipoprotein (LDL) particles are a major risk factor for cardiovascular morbidity and mortality. Both estrogens and smoking, with known anti-estrogenic effects, alter the atherogenic lipid profile. We tested for a role of interaction between smoking and estrogen receptor alpha gene (ESR1) variation in association with plasma concentration of atherogenic small LDL particles and LDL particle size. We studied 1727 unrelated subjects, 854 women and 873 men, mean age 51 years (SD 10), from the population-based Framingham Heart Study. After covariate adjustment, women who smoked and had the common ESR1 c.454-397 TT genotype (in 30% of women, T was present on both chromosomes at position 397 prior to the start of exon 2) had >1.7-fold higher levels of small LDL particles than women with the alternative genotypes (P-value for smoking-genotype interaction was 0.001). Similar results were obtained for three other ESR1 variants including c.454-351A > G, in the same linkage disequilibrium block. A similar substantial gender-specific result was also evident with a fifth variant, in a separate linkage disequilibrium block, in exon 4 (P = 0.003). Women who smoked and had specific, common ESR1 genotypes had a substantially higher plasma concentration of atherogenic small LDL particles. Significant results revealed a dose-dependent effect of smoking and were evident in both pre- and postmenopausal women. The reported association has the potential to explain the risks associated with estrogen use in certain women and a recent report of association between an ESR1 haplotype comprised of c.454-397 T and c.454-351 A alleles with increased myocardial infarction and ischaemic heart disease, independent of the standard, established cardiovascular risk factors.  相似文献   

20.

Background

Osteoporosis, characterized by low bone mineral density (BMD) and high bone fracture risk, is prevalent in Thai menopausal women. Genetic factors are known to play a key role in BMD. Low density lipoprotein receptor-related protein 5 (LRP5), a co-receptor in the Wnt/beta-catenin pathway, is involved in many aspects of bone biology. As coding single nucleotide polymorphisms (cSNPs) of LRP5, including A1330V (rs3736228), and Asian-related Q89R (rs41494349) and N740N (rs2306862), are associated with lowered BMD, this study aimed to determine the relationship between these LRP5 polymorphisms and BMD in 277 Thai menopausal women.

Results

Only rs3736228 deviated from the Hardy–Weinberg equilibrium of allele frequency (p = 0.022). The median, range and p value for the BMD related to each SNP parameter were compared (Mann–Whitney U test). Significant differences were observed between wild-type and risk alleles for both rs3736228 (total radial, p = 0.011; and radial 33, p = 0.001) and rs2306862 (radial 33: p = 0.015) SNPs, with no significant difference for rs41494349 SNP. Linkage disequilibrium was strong for both rs3736228 and rs2306862 SNPs. Haplotype analysis identified high CC frequency in both normal and osteopenia/osteoporosis groups, with a significant odds ratio for carrying the TT haplotype; however, this was non-significant after adjusting for age. Multivariate binary logistic regression analysis performed for rs3736228 showed that individuals with a body mass index <25 kg/m2 had an increased risk of osteoporosis for each decade, but the polymorphism had no effect.

Conclusions

This study did not identify LRP5 polymorphisms as a risk factor for osteoporosis in Thai menopausal women. Further studies with larger sample sizes are needed to further clarify the role of LRP5 as a genetic determinant of osteoporosis.
  相似文献   

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