Transcriptional regulation of a BMP-6 promoter by estrogen receptor alpha.

The effects of 17beta-estradiol (E2) and ICI 182,780 (ICI) on activity of a BMP-6 promoter were compared in osteoblast-like and breast cancer cells transiently transfected with ERalpha. E2 but not ICI stimulated BMP-6 reporter activity in breast cancer cells, whereas the opposite was observed in osteoblast-like cells, associated with lack of AF-2 dependence of the response, and absent intranuclear localization of ERalpha, suggesting the involvement of a distinct ERalpha-dependent response mechanism in osteoblasts. INTRODUCTION: Previous studies suggest that the tissue-selective effect of antiestrogens on bone reflects the ability of these compounds to target certain osteoblast regulatory genes. To explore this hypothesis, we examined whether antiestrogens preferentially stimulate the bone morphogenetic protein 6 (BMP-6) promoter in bone cells, and if so, whether this activity is associated with a distinct estrogen receptor (ER)alpha-dependent response mechanism to that in other cell types. MATERIALS AND METHODS: We compared the effects of 17beta-estradiol (E2) and ICI 182,780 (ICI) on activity of a 4.3-kb BMP-6 reporter construct in osteoblast-like cells (human MG63 and SaOS-2 cells and rat ROS 17/2.8 cells), human MCF-7 and T47-D breast cancer cell lines, and HepG2 hepatoma cells, after transient transfection with ERalpha, ERbeta, and mutant ER constructs. RESULTS: E2, but not ICI, stimulated BMP-6 reporter activity by approximately 100% in MCF-7, T47-D cells, and HepG2 cells when transfected with ERalpha. In contrast, in ERalpha-transfected osteoblast-like cells, an increase in reporter activity of approximately 75% was observed after treatment with ICI but not E2. The response of MG63 cells to ICI and MCF-7 cells to E2 both required ERalpha as opposed to ERbeta and the ERalpha activation function (AF)-1 activation domain. However, whereas the AF-2 domain was also required for E2 to stimulate reporter activity in MCF-7 cells, the response to ICI in MG63 cells was AF-2 independent. In further studies where we compared the intracellular distribution of ERalpha associated with these responses, E2-dependent stimulation of the BMP-6 reporter in MCF-7 cells was associated with intranuclear localization of ERalpha, whereas extranuclear localization was seen in rat osteosarcoma cells (ROS) cells treated with ICI. CONCLUSIONS: Antiestrogens selectively stimulate BMP-6 reporter activity in osteoblast-like cells through a distinct ERalpha-dependent mechanism characterized by independence of the AF-2 domain and extranuclear localization of ERalpha.     

Association of a sodium channel alpha subunit promoter variant with blood pressure.

The SCNNIA gene, which is located on human chromosome 12p13.3, encodes the alpha subunit of the amiloride-sensitive epithelial sodium channel, and mutations in SCNNIA can result in pseudohypoaldosteronism type I. It was postulated that genetic variations in SCNN1A could lead to an increased risk of hypertension. Sequence variations in SCNN1A were identified, and the association between these polymorphisms and BP was examined in a large cohort (n = 3898) representing the general population in Japan. Four polymorphisms in the promoter region, three polymorphisms in the exonic region, and one polymorphism in the first intron were identified. Because association studies with one-half of the study population indicated that the A(2139)G polymorphism, among others, significantly affected BP, this polymorphism was studied in the entire study population. Multiple logistic analyses indicated that the odds ratio for hypertension with the GA+GG genotype was 1.31 (P = 0.0154) in the total population and 1.77 (P = 0.0035) among subjects <60 yr of age. A significantly higher frequency of proteinuria was also observed among subjects with the GA+GG genotype. A transient transfection assay using MDCK cells indicated that the promoter activity of the G(2139) allele was higher than that of the A(2139) allele. Therefore, possession of the SCNN1A G(2139) allele significantly increased the risk of hypertension. A lower level of SCNN1A subunit expression among subjects with the AA genotype might lead to lower levels of sodium reabsorption in the kidney and might provide protection against the development of hypertension.     

Profiling of endogenous ligand solutes that bind to serum proteins in sera of patients with uremia

The profiling of endogenous ligand solutes in sera of patients with uremia was performed by using an ultrafiltration device and high-performance liquid chromatography. Seventeen endogenous ligand solutes, which are ultraviolet-absorbing substances, were detected in a sample volume of 40 microliters, and four ligand solutes were tentatively identified as indoxylsulfate, hippuric acid, 2-hydroxybenzoylglycine, and 3-indoleacetic acid. One of these ligand solutes designated as peak P was thought to be a candidate for a major drug-binding inhibitor in uremia.     

Anti-DNA antibodies can bind to the glomerulus via two distinct mechanisms.

It is generally assumed that antibodies to double stranded DNA (anti-DNA) play a pivotal role in the pathogenesis of SLE nephritis. Recently, we reported that anti-DNA antibodies can bind to heparan sulphate proteoglycan (HSPG), a constituent of the glomerular basement membrane (GBM), via histones and DNA. We postulated that these histone/DNA/anti-DNA complexes can bind via their histone part to the glomerulus in vivo. To test this hypothesis we performed in vitro binding studies with isolated GBM loops and renal perfusion studies in the rat using histones, DNA and an anti-DNA monoclonal antibody (mAb) with high avidity for dsDNA. A strong granular binding of anti-DNA mAb to isolated GBM loops occurred via histones and DNA and a moderate granular binding was found via DNA alone. Anti-DNA mAb alone did not bind to the GBM loops. After perfusion of histones, DNA and immediately thereafter anti-DNA, we found with immunoelectron microscopy (IEM) a strong binding to endothelial cells in the glomerulus and to a lesser extent in the GBM. When the anti-DNA mAb was injected i.v. one hour after perfusion of histones and DNA, we observed a strong fine granular binding to the capillary wall by immunofluorescence (IF) in a membranous pattern along with some minor mesangial deposits. After perfusion of DNA alone followed by anti-DNA mAb, binding in the glomerulus was less than with histones and DNA, and was more restricted to the mesangium. No direct binding to the glomerulus was observed after perfusion with anti-DNA mAb alone, histones and anti-DNA mAb, or histones, DNA and a control mAb.(ABSTRACT TRUNCATED AT 250 WORDS)     

胃癌与细胞毒性T淋巴细胞相关抗原-4基因启动子区域多态性的相关性研究

目的探讨细胞毒性T淋巴细胞相关抗原（CTLA）-4基因启动子区-1722位点（T／C）多态性和-1661位点（A／G）多态性与中国汉族人群中胃癌的相关性。方法采用聚合酶链反应（PCR）-限制性片段长度多态性（RFLP）方法，对183例胃癌患者和116例中国汉族正常对照者进行CTLA-4基因-1722位点和-1661位点多态性检测。结果与正常对照组比较，胃癌患者CTLA-4基因-1661位点AA基因型频率，-1661位点A等位基因频率显著降低（65．6％vs84．5％；P〈0．01；odds ratio=0．3499；95％CI=0．1943—0．6299；81．1％vs91．8％；P〈0．01；odds ratio=2．6040；95％CI=1．521—4．458）。结论CTLA-4基因启动子区-1661位点A等位基因与中国汉族胃癌显著相关。     

Association of HLA-DR3 and HLA-DR4 with sinonasal polyposis in Mexican Mestizos.

OBJECTIVE: The pathogenesis of sinonasal polyposis (SNP) is not clear; it has been suggested that it is polygenic and multifactorial. The major histocompatibility complex is a useful tool to predict genetic susceptibility to diseases, especially to autoimmune diseases. Since such susceptibility is influenced by ethnicity, it is necessary to have a wide knowledge of the structure of the population to which the patient belongs. The purpose of the study was to determine the association of HLA-DRB1 alleles with sinonasal polyposis in the Mexican Mestizo population. STUDY DESIGN: We studied the HLA-DR alleles in 34 adult Mexican Mestizo patients with SNP and compared them to those present in 99 healthy controls. METHODS: Genomic DNA from mononuclear cells was obtained by using the "salting out" technique and high-resolution DNA typing of the HLA-DRB1 alleles was performed after PCR amplification. RESULTS: We found a statistically significant increased frequency of the HLA-DRB1*03 allele (P = 0.03, odds ratio [OR] = 2.9, 95% confidence interval [CI]: 1.0-7.8) and of the HLA-DRB1*04 allele (P = 0.009, OR = 2.2, 95% CI: 1.2-4.2) in patients with SNP as compared to controls, and a statistically significant decreased frequency of the HLA-DRB1*08 allele (P = 0.01, OR = 0.2, 95% CI: 0.05-0.8). CONCLUSION: The HLA-DR locus seems to be associated with the genetic susceptibility to develop SNP in Mexicans. EBM rating: B-2b.     

Penetrating injury to the gluteal region.

Eight cases of life-threatening sequelae of relatively minor penetrating injuries of the gluteal region, involving the gluteal or internal pudendal arteries, are reported. The modes of presentation included exsanguinating external hemorrhage (two), acute false aneurysm (one), and chronic false aneurysm (five). Failure to appreciate the nature of the lesion led to inappropriate initial management in seven instances. This series emphasizes the danger of direct incision of lesions in this region which are suspected of being abscesses that are in fact false aneurysms ("pulsatile abscesses") and demonstrates the need for a high index of suspicion for problems related to these vessels following penetrating trauma to the gluteal region, even if seemingly minor, and the need for adequate investigation and planning before surgery.     

Microsurgical approach to the parasellar region.

The anatomical structures of the parasellar region are described from the microsurgical point of view. The study was performed on 20 autopsied specimens.