929 resultados para OX-LDL RECEPTOR-1


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Metabolic disturbances are quite common in critically ill patients. Glycemic control appears to be an important adjuvant therapy in such patients. In addition, disorders of lipid metabolism are associated with worse prognoses. The purpose of this study was to investigate the effects that two different glycemic control protocols have on lipid profile and metabolism. We evaluated 63 patients hospitalized for severe sepsis or septic shock, over the first 72 h of intensive care. Patients were randomly allocated to receive conservative glycemic control (target range 140-180 mg/dl) or intensive glycemic control (target range 80-110 mg/dl). Serum levels of low-density lipoprotein, high-density lipoprotein, triglycerides, total cholesterol, free fatty acids, and oxidized low-density lipoprotein were determined. In both groups, serum levels of low-density lipoprotein, high-density lipoprotein, and total cholesterol were below normal, whereas those of free fatty acids, triglycerides, and oxidized low-density lipoprotein were above normal. At 4 h after admission, free fatty acid levels were higher in the conservative group than in the intensive group, progressively decreasing in both groups until hour 48 and continuing to decrease until hour 72 only in the intensive group. Oxidized low-density lipoprotein levels were elevated in both groups throughout the study period. Free fatty acids respond to intensive glycemic control and, because of their high toxicity, can be a therapeutic target in patients with sepsis.

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Low-density lipoprotein (LDL) receptors are overexpressed in most neoplastic cell lines and provide a mechanism for the internalization and concentration of drug-laden nanoemulsions that bind to these receptors. The aim of the present study was to determine whether the administration of standard chemotherapeutic schemes can alter the expression of LDL and LDL receptor-related protein 1 (LRP-1) receptors in breast carcinoma. Fragments of tumoral and normal breast tissue from 16 consecutive volunteer women with breast cancer in stage II or III were obtained from biopsies before the beginning of neoadjuvant chemotherapy and after chemotherapy, from fragments excised during mastectomy. Tissues were analyzed by immunohistochemistry for both receptors. Because complete response to treatment was achieved in 4 patients, only the tumors from 12 were analyzed. Before chemotherapy, there was overexpression of LDL receptor in the tumoral tissue compared to normal breast tissue in 8 of these patients. LRP-1 receptor overexpression was observed in tumors of 4 patients. After chemotherapy, expression of both receptors decreased in the tumors of 6 patients, increased in 4 and was unchanged in 2. Nonetheless, even when chemotherapy reduced receptors expression, the expression was still above normal. The fact that chemotherapy does not impair LDL receptors expression supports the use of drug carrier systems that target neoplastic cells by the LDL receptor endocytic pathway in patients on conventional chemotherapy.

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Low-density lipoprotein receptor-related protein (LRP) mediates internalization of urokinase:plasminogen activator inhibitor complexes (uPA:PAI-1) and the urokinase receptor (uPAR). Here we investigated whether direct interaction between uPAR, a glycosyl-phosphatidylinositol–anchored protein, and LRP, a transmembrane receptor, is required for clearance of uPA:PAI-1, regeneration of unoccupied uPAR, activation of plasminogen, and the ability of HT1080 cells to invade extracellular matrix. We found that in the absence of uPA:PAI-1, uPAR is randomly distributed along the plasma membrane, whereas uPA:PAI-1 promotes formation of uPAR-LRP complexes and initiates redistribution of occupied uPAR to clathrin-coated pits. uPAR-LRP complexes are endocytosed via clathrin-coated vesicles and traffic together to early endosomes (EE) because they can be coimmunoprecipitated from immunoisolated EE, and internalization is blocked by depletion of intracellular K+. Direct binding of domain 3 (D3) of uPAR to LRP is required for clearance of uPA-PAI-1–occupied uPAR because internalization is blocked by incubation with recombinant D3. Moreover, uPA-dependent plasmin generation and the ability of HT1080 cells to migrate through Matrigel-coated invasion chambers are also inhibited in the presence of D3. These results demonstrate that GPI-anchored uPAR is endocytosed by piggybacking on LRP and that direct binding of occupied uPAR to LRP is essential for internalization of occupied uPAR, regeneration of unoccupied uPAR, plasmin generation, and invasion and migration through extracellular matrix.

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Background We have previously reported an association between the estrogen receptor 1 (ESR1) gene exon 8 G594A polymorphism and migraine susceptibility in two independent Australian cohorts. In this paper we report results of analysis of two further single nucleotide polymorphisms (SNPs) in the ESR1 gene in the same study group, the T/C Pvu II SNP in intron 1 and the C325G SNP in exon 4, as well as results of linkage disequilibrium (LD) analysis on these markers. Methods We investigated these variants by case-control association analysis in a cohort of 240 migraineurs and 240 matched controls. The SNPs were genotyped using specific restriction enzyme assays. Results were analysed using contingency table methods incorporating the chi-squared statistic. LD results are presented as D' statistics with associated P values. Results We found no evidence for association of the Pvu II T/C polymorphism and the C325G polymorphism and migraine susceptibility and no evidence for LD between these two SNPs and the previously implicated exon 8 G594A marker. Conclusion We have found no role for the polymorphisms in intron 1 and exon 4 with migraine susceptibility. To further investigate our previously implicated exon 8 marker, we suggest the need for studies with a high density of polymorphisms be undertaken, with particular focus on markers in LD with the exon 8 marker.

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Migraine is a painful and debilitating disorder with a significant genetic component. Steroid hormones, in particular estrogen, have long been considered to play a role in migraine, as variations in hormone levels are associated with migraine onset in many sufferers of the disorder. Steroid hormones mediate their activity via hormone receptors, which have a wide tissue distribution. Estrogen receptors have been localized to the brain in regions considered to be involved in migraine pathogenesis. Hence it is possible that genetic variation in the estrogen receptor gene may play a role in migraine susceptibility. This study thus examined the estrogen receptor 1 (ESRα) gene for a potential role in migraine pathogenesis and susceptibility. A population-based cohort of 224 migraine sufferers and 224 matched controls were genotyped for the G594A polymorphism located in exon 8 of the ESR1 gene. Statistical analysis indicated a significant difference between migraineurs and non-migraineurs in both the allele frequencies (P=0.003) and genotype distributions (P=0.008) in this sample. An independent follow-up study was then undertaken using this marker in an additional population-based cohort of 260 migraine sufferers and 260 matched controls. This resulted in a significant association between the two groups with regard to allele frequencies (P=8×10−6) and genotype distributions (P=4×10−5). Our findings support the hypothesis that genetic variation in hormone receptors, in particular the ESR1 gene, may play a role in migraine.

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Introduction Sphingosine-1-phosphate receptor 1 (S1P1) is crucial for regulation of immunity and bone metabolism. This study aimed to investigate the expression of S1P1 in rat periapical lesions and its relationship with receptor activator of nuclear factor kappa B ligand (RANKL) and regulatory T (Treg) cells. Methods Periapical lesions were induced by pulp exposure in the first lower molars of 55 Wistar rats. Thirty rats were killed on days 0, 7, 14, 21, 28, and 35, and their mandibles were harvested for x-ray imaging, micro–computed tomography scanning, histologic observation, immunohistochemistry, enzyme histochemistry, and double immunofluorescence analysis. The remaining 25 rats were killed on days 0, 14, 21, 28, and 35, and mandibles were harvested for flow cytometry. Results The volume and area of the periapical lesions increased from day 0 to day 21 and then remained comparably stable after day 28. S1P1-positive cells were observed in the inflammatory periapical regions; the number of S1P1-positive cells peaked at day 14 and then decreased from day 21 to day 35. The distribution of S1P1-positive cells was positively correlated with the dynamics of RANKL-positive cells but was negatively correlated with that of Treg cells. Conclusions S1P1 expression was differentially correlated with RANKL and Treg cell infiltration in the periapical lesions and is therefore a contributing factor to the pathogenesis of such lesions.

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Bone mass accrual and maintenance are regulated by a complex interplay between genetic and environmental factors. Recent studies have revealed an important role for the low-density lipoprotein receptor-related protein 5 (LRP5) in this process. The aim of this thesis study was to identify novel variants in the LRP5 gene and to further elucidate the association of LRP5 and its variants with various bone health related clinical characteristics. The results of our studies show that loss-of-function mutations in LRP5 cause severe osteoporosis not only in homozygous subjects but also in the carriers of these mutations, who have significantly reduced bone mineral density (BMD) and increased susceptibility to fractures. In addition, we demonstrated for the first time that a common polymorphic LRP5 variant (p.A1330V) was associated with reduced peak bone mass, an important determinant of BMD and osteoporosis in later life. The results from these two studies are concordant with results seen in other studies on LRP5 mutations and in association studies linking genetic variation in LRP5 with BMD and osteoporosis. Several rare LRP5 variants were identified in children with recurrent fractures. Sequencing and multiplex ligation-dependent probe amplification (MLPA) analyses revealed no disease-causing mutations or whole-exon deletions. Our findings from clinical assessments and family-based genotype-phenotype studies suggested that the rare LRP5 variants identified are not the definite cause of fractures in these children. Clinical assessments of our study subjects with LPR5 mutations revealed an unexpectedly high prevalence of impaired glucose tolerance and dyslipidaemia. Moreover, in subsequent studies we discovered that common polymorphic LRP5 variants are associated with unfavorable metabolic characteristics. Changes in lipid profile were already apparent in pre-pubertal children. These results, together with the findings from other studies, suggest an important role for LRP5 also in glucose and lipid metabolism. Our results underscore the important role of LRP5 not only in bone mass accrual and maintenance of skeletal health but also in glucose and lipid metabolism. The role of LRP5 in bone metabolism has long been studied, but further studies with larger study cohorts are still needed to evaluate the specific role of LRP5 variants as metabolic risk factors.

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Pre-eclampsia is a pregnancy complication that affects about 5% of all pregnancies. It is known to be associated with alterations in angiogenesis -related factors, such as vascular endothelial growth factor (VEGF). An excess of antiangiogenic substances, especially the soluble receptor-1 of VEGF (sVEGFR-1), has been observed in maternal circulation after the onset of the disease, probably reflecting their increased placental production. Smoking reduces circulating concentrations of sVEGFR-1 in non-pregnant women, and in pregnant women it reduces the risk of pre-eclampsia. Soluble VEGFR-1 acts as a natural antagonist of VEGF and placental growth factor (PlGF) in human circulation, holding a promise for potential therapeutic use. In fact, it has been used as a model to generate a fusion protein, VEGF Trap , which has been found effective in anti-angiogenic treatment of certain tumors and ocular diseases. In the present study, we evaluated the potential use of maternal serum sVEGFR-1, Angiopoietin-2 (Ang-2) and endostatin, three central anti-angiogenic markers, in early prediction of subsequent pre-eclampsia. We also studied whether smoking affects circulating sVEGFR-1 concentrations in pregnant women or their first trimester placental secretion and expression in vitro. Last, in order to allow future discussion on the potential therapy based on sVEGFR-1, we determined the biological half-life of endogenous sVEGFR-1 in human circulation, and measured the concomitant changes in free VEGF concentrations. Blood or placental samples were collected from a total of 268 pregnant women between the years 2001 2007 in Helsinki University Central Hospital for the purposes above. The biomarkers were measured using commercially available enzyme-linked immunosorbent assays (ELISA). For the analyses of sVEGFR-1, Ang-2 and endostatin, a total of 3 240 pregnant women in the Helsinki area were admitted to blood sample collection during two routine ultrasoundscreening visits at 13.7 ± 0.5 (mean ± SD) and 19.2 ± 0.6 weeks of gestation. Of them, 49 women later developing pre-eclampsia were included in the study. Their disease was further classified as mild in 29 and severe in 20 patients. Isolated early-onset intrauterine growth retardation (IUGR) was diagnosed in 16 women with otherwise normal medical histories and uncomplicated pregnancies. Fifty-nine women remaining normotensive, non-proteinuric and finally giving birth to normal-weight infants were picked to serve as the control population of the study. Maternal serum concentrations of Ang-2, endostatin and sVEGFR-1, were increased already at 16 20 weeks of pregnancy, about 13 weeks before the clinical manifestation of preeclampsia. In addition, these biomarkers could be used to identify women at risk with a moderate precision. However, larger patient series are needed to determine whether these markers could be applied for clinical use to predict preeclampsia. Intrauterine growth retardation (IUGR), especially if noted at early stages of pregnancy and not secondary to any other pregnancy complication, has been suggested to be a form of preeclampsia compromising only the placental sufficiency and the fetus, but not affecting the maternal endothelium. In fact, IUGR and preeclampsia have been proposed to share a common vascular etiology in which factors regulating early placental angiogenesis are likely to play a central role. Thus, these factors have been suggested to be involved in the pathogenesis of IUGR. However, circulating sVEGFR-1, Ang-2 and endostatin concentrations were unaffected by subsequent IUGR at early second trimester. Furthermore, smoking was not associated with alterations in maternal circulating sVEGFR-1 or its placental production. The elimination of endogenous sVEGFR-1 after pregnancy was calculated from serial samples of eight pregnant women undergoing elective Caesarean section. As typical for proteins in human compartments, the elimination of sVEGFR-1 was biphasic, containing a rapid halflife of 3.4 h and a slow one of 29 h. The decline in sVEGFR-1 concentrations after mid-trimester legal termination of pregnancy was accompanied with a simultaneous increase in the serum levels of free VEGF so that within a few days after pregnancy VEGF dominated in the maternal circulation. Our study provides novel information on the kinetics of endogenous sVEGFR-1, which serves as a potential tool in the development of new strategies against diseases associated with angiogenic imbalance and alterations in VEGF signaling.

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The vomeronasal receptor 1 (V1R) are believed to be pheromone receptors in rodents. Here we used computational methods to identify 95 and 62 new putative V1R genes from the draft rat and mouse genome sequence, respectively. The rat V1R repertoire consists of 11 subfamilies, 10 of which are shared with the mouse, while rat appears to lack the H and I subfamilies found in mouse and possesses one unique subfamily (M). The estimations of the relative divergence times suggest that many subfamilies originated after the split of rodents and primates. The analysis also reveals that these clusters underwent an expansion very close to the split of mouse and rat. In addition, maximum likelihood analysis showed that the nonsynonymous and synonymous rate ratio for most of these clusters was much higher than one, suggesting the role of positive selection in the diversification of these duplicated V1R genes. Because V1R are thought to mediate the process of signal transduction in response to pheromone detection, we speculate that the V1R genes have evolved under positive Darwinian selection to maintain the ability to discriminate between large and complex pheromonal mixtures.

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Background Interferon ? receptor 1 (IFN? R1) deficiency is a primary immunodeficiency with allelic dominant and recessive mutations characterised clinically by severe infections with mycobacteria. We aimed to compare the clinical features of recessive and dominant IFN?R1 deficiencies. Methods We obtained data from a large cohort of patients worldwide. We assessed these people by medical histories, records, and genetic and immunological studies. Data were abstracted onto a standard form. Findings We identified 22 patients with recessive complete IFN?R1 deficiency and 38 with dominant partial deficiency. BCG and environmental mycobacteria were the most frequent pathogens. In recessive patients, 17 (77%) had environmental mycobacterial disease and all nine BCG-vaccinated patients had BCG disease. In dominant patients, 30 (79%) had environmental mycobacterial disease and 11 (73%) of 15 BCG-vaccinated patients had BCG disease. Compared with dominant patients, those with recessive deficiency were younger at onset of first environmental mycobacterial disease (mean 3·1 years [SD 2·5] vs 13·4 years [14·3], p=0·001), had more mycobacterial disease episodes (19 vs 8 per 100 person-years of observation, p=0·0001), had more severe mycobacterial disease (mean number of organs infected by Mycobacterium avium complex 4·1 [SD 0·8] vs 2·0 [1·1], p=0·004), had shorter mean disease-free intervals (1·6 years [SD 1·4] vs 7·2 years [7·6], p