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Background: Observational studies suggest interconnections between thyroid status, metabolism, and risk of coronary artery disease (CAD), but causality remains to be proven. The present study aimed to investigate the potential causal relationship between thyroid status and cardiovascular disease and to characterize the metabolomic profile associated with thyroid status.Methods: Multi-cohort two-sample Mendelian randomization (MR) was performed utilizing genome-wide significant variants as instruments for standardized thyrotropin (TSH) and free thyroxine (fT4) within the reference range. Associations between TSH and fT4 and metabolic profile were investigated in a two-stage manner: associations between TSH and fT4 and the full panel of 161 metabolomic markers were first assessed hypothesis-free, then directional consistency was assessed through Mendelian randomization, another metabolic profile platform, and in individuals with biochemically defined thyroid dysfunction.Results: Circulating TSH was associated with 52/161 metabolomic markers, and fT4 levels were associated with 21/161 metabolomic markers among 9432 euthyroid individuals (median age varied from 23.0 to 75.4 years, 54.5% women). Positive associations between circulating TSH levels and concentrations of very low-density lipoprotein subclasses and components, triglycerides, and triglyceride content of lipoproteins were directionally consistent across the multivariable regression, MR, metabolomic platforms, and for individuals with hypo- and hyperthyroidism. Associations with fT4 levels inversely reflected those observed with TSH. Among 91,810 CAD cases and 656,091 controls of European ancestry, per 1-SD increase of genetically determined TSH concentration risk of CAD increased slightly, but not significantly, with an OR of 1.03 (95% CI 0.99-1.07; p value 0.16), whereas higher genetically determined fT4 levels were not associated with CAD risk (OR 1.00 per SD increase of fT4; 95% CI 0.96-1.04; p value 0.59).Conclusions: Lower thyroid status leads to an unfavorable lipid profile and a somewhat increased cardiovascular disease risk. [ABSTRACT FROM AUTHOR]

Background: In Taiwan, DNA-based newborn screening showed a surprisingly high incidence of a cardiac Fabry mutation (IVS4 + 919G > A). The prevalence of this mutation is too high to be believed that it is a real pathogenic mutation. The purpose of this study is to identify the cardiac pathologic characteristics in patients with left ventricular hypertrophy and this mutationMethods and Results: Endomyocardial biopsies were obtained in 22 patients (Median age: 61, males: 17; females: 5) with left ventricular hypertrophy and the IVS4 + 919G > A mutation; five patients had not received enzyme replacement therapy (ERT) before biopsy, while the other 17 patients had received ERT from 8 months to 51 months. Except for three patients who had received ERT for more than 3 years, all other patients showed significant pathological change and globotriaosylceramide (Gb3) accumulation in their cardiomyocytes. In contrast to classical Fabry patients, no Gb3 accumulation was found in the capillary endothelial cells of any of our patients. Fourteen patients (63.6%) were found to have myofibrillolysis.Conclusions: All of the untreated and most of the treated IVS4 + 919G > A patients showed typical pathological changes of Fabry disease in their cardiomyocytes. No endothelial accumulation of Gb3 was found, which is similar to the findings of several previous reports regarding later-onset Fabry disease. This result highly suggests that the IVS4 + 919G > A is a real pathogenic later-onset Fabry mutation. [ABSTRACT FROM AUTHOR]

Background: Breast-conserving surgery (BCS) followed by radiotherapy is generally the preferred treatment for women diagnosed with early stage breast cancer. This study aimed to investigate the proportion of patients who receive BCS versus mastectomy and post-BCS radiotherapy, and explore factors associated with receipt of these treatments in Alberta, Canada., Methods: A retrospective population-based study was conducted that including all patients surgically treated with stage I-III breast cancer diagnosed in Alberta from 2002-2010. Clinical characteristics, treatment information and patient age at diagnosis were collected from the Alberta Cancer Registry. Log binomial multiple regression was used to calculate stage-specific relative risk estimates of receiving BCS and post-BCS radiotherapy., Results: Of the 14 646 patients included in the study, 44% received BCS, and of those, 88% received post-BCS radiotherapy. The adjusted relative risk of BCS was highest in Calgary and lowest in Central Alberta for all disease stages. Relative to surgeries performed in Calgary, those performed in Central Alberta were significantly less likely to be BCS for stage I (RR = 0.65; 95% 0.57, 0.72), II (RR = 0.58; 95% 0.49, 0.68), and III (RR = 0.62; 95% CI: 0.37, 0.95) disease, respectively, adjusting for patient age at diagnosis, clinical and treatment characteristics. No significant variation of post-BCS radiotherapy was found., Conclusions: Factors such as region of surgical treatment should not be related to the receipt of standard care within a publicly-funded health care system. Further investigation is needed to understand the significant geographic variation present within the province in order to identify appropriate interventions.

Background: The cAMP receptor protein (CRP) is a global bacterial regulator that controls many target genes. The CRP-cAMP complex regulates the ompR-envZ operon in E. coli directly, involving both positive and negative regulations of multiple target promoters; further, it controls the production of porins indirectly through its direct action on ompR-envZ. Auto-regulation of CRP has also been established in E. coli. However, the regulation of porin genes and its own gene by CRP remains unclear in Y. pestis., Results: Y. pestis employs a distinct mechanism indicating that CRP has no regulatory effect on the ompR-envZ operon; however, it stimulates ompC and ompF directly, while repressing ompX. No transcriptional regulatory association between CRP and its own gene can be detected in Y. pestis, which is also in contrast to the fact that CRP acts as both repressor and activator for its own gene in E. coli. It is likely that Y. pestis OmpR and CRP respectively sense different signals (medium osmolarity, and cellular cAMP levels) to regulate porin genes independently., Conclusion: Although the CRP of Y. pestis shows a very high homology to that of E. coli, and the consensus DNA sequence recognized by CRP is shared by the two bacteria, the Y. pestis CRP can recognize the promoters of ompC, F, and X directly rather than that of its own gene, which is different from the relevant regulatory circuit of E. coli. Data presented here indicate a remarkable remodeling of the CRP-mediated regulation of porin genes and of its own one between these two bacteria.

Background: The osmotic regulator OmpR in Escherichia coli regulates differentially the expression of major porin proteins OmpF and OmpC. In Yersinia enterocolitica and Y. pseudotuberculosis, OmpR is required for both virulence and survival within macrophages. However, the phenotypic and regulatory roles of OmpR in Y. pestis are not yet fully understood., Results: Y. pestis OmpR is involved in building resistance against phagocytosis and controls the adaptation to various stressful conditions met in macrophages. The ompR mutation likely did not affect the virulence of Y. pestis strain 201 that was a human-avirulent enzootic strain. The microarray-based comparative transcriptome analysis disclosed a set of 224 genes whose expressions were affected by the ompR mutation, indicating the global regulatory role of OmpR in Y. pestis. Real-time RT-PCR or lacZ fusion reporter assay further validated 16 OmpR-dependent genes, for which OmpR consensus-like sequences were found within their upstream DNA regions. ompC, F, X, and R were up-regulated dramatically with the increase of medium osmolarity, which was mediated by OmpR occupying the target promoter regions in a tandem manner., Conclusion: OmpR contributes to the resistance against phagocytosis or survival within macrophages, which is conserved in the pathogenic yersiniae. Y. pestis OmpR regulates ompC, F, X, and R directly through OmpR-promoter DNA association. There is an inducible expressions of the pore-forming proteins OmpF, C, and × at high osmolarity in Y. pestis, in contrast to the reciprocal regulation of them in E. coli. The main difference is that ompF expression is not repressed at high osmolarity in Y. pestis, which is likely due to the absence of a promoter-distal OmpR-binding site for ompF.

Background: Pathogenic yersiniae, including Y. pestis, share a type III secretion system (T3SS) that is composed of a secretion machinery, a set of translocation proteins, a control system, and six Yop effector proteins including YpkA and YopJ. The cyclic AMP receptor protein (CRP), a global regulator, was recently found to regulate the laterally acquired genes (pla and pst) in Y. pestis. The regulation of T3SS components by CRP is unknown., Results: The sycO, ypkA and yopJ genes constitute a single operon in Y. pestis. CRP specifically binds to the promoter-proximate region of sycO, and represses the expression of the sycO-ypkA-yopJ operon. A single CRP-dependent promoter is employed for the sycO-ypkA-yopJ operon, but two CRP binding sites (site 1 and site 2) are detected within the promoter region. A CRP box homologue is found in site 1 other than site 2. The determination of CRP-binding sites, transcription start site and core promoter element (-10 and -35 regions) promotes us to depict the structural organization of CRP-dependent promoter, giving a map of CRP-promoter DNA interaction for sycO-ypkA-yopJ., Conclusion: The sycO-ypkA-yopJ operon is under the direct and negative regulation of CRP in Y. pestis. The sycO-ypkA-yopJ promoter-proximate regions are extremely conserved in Y. pestis, Y. pseudotuberculosis and Y. enterocolitica. Therefore, data presented here can be generally applied to the above three pathogenic yersiniae.

Background: The zinc uptake regulator Zur is a Zn2+-sensing metalloregulatory protein involved in the maintenance of bacterial zinc homeostasis. Up to now, regulation of zinc homeostasis by Zur is poorly understood in Y. pestis., Results: We constructed a zur null mutant of Y. pestis biovar microtus strain 201. Microarray expression analysis disclosed a set of 154 Zur-dependent genes of Y. pestis upon exposure to zinc rich condition. Real-time reverse transcription (RT)-PCR was subsequently used to validate the microarray data. Based on the 154 Zur-dependent genes, predicted regulatory Zur motifs were used to screen for potential direct Zur targets including three putative operons znuA, znuCB and ykgM-RpmJ2. The LacZ reporter fusion analysis verified that Zur greatly repressed the promoter activity of the above three operons. The subsequent electrophoretic mobility shift assay (EMSA) demonstrated that a purified Zur protein was able to bind to the promoter regions of the above three operons. The DNase I footprinting was used to identify the Zur binding sites for the above three operons, verifying the Zur box sequence as predicted previously in gamma-Proteobacteria. The primer extension assay was further used to determine the transcription start sites for the above three operons and to localize the -10 and -35 elements. Zur binding sites overlapped the -10 sequence of its target promoters, which was consistent with the previous observation that Zur binding would block the entry of the RNA polymerase to repress the transcription of its target genes., Conclusion: Zur as a repressor directly controls the transcription of znuA, znuCB and ykgM-RpmJ2 in Y. pestis by employing a conserved mechanism of Zur-promoter DNA association as observed in gamma-Proteobacteria. Zur contributes to zinc homeostasis in Y. pestis likely through transcriptional repression of the high-affinity zinc uptake system ZnuACB and two alternative ribosomal proteins YkgM and RpmJ2.

Background: The transcription regulator PhoP has been shown to be important for Y. pestis survival in macrophages and under various in vitro stresses. However, the mechanism by which PhoP promotes bacterial intracellular survival is not fully understood. Our previous microarray analysis suggested that PhoP governed a wide set of cellular pathways in Y. pestis. A series of biochemical experiments were done herein to study members of the PhoP regulon of Y. pestis biovar Microtus., Results: By using gel mobility shift assay and quantitative RT-PCR, a total of 30 putative transcription units were characterized as direct PhoP targets. The primer extension assay was further used to determine the transcription start sites of 18 PhoP-dependent promoters and to localize the -10 and -35 elements. The DNase I footprinting was used to identify the PhoP-binding sites within 17 PhoP-dependent promoters, enabling the identification of PhoP box and matrix that both represented the conserved signals for PhoP recognition in Y. pestis. Data presented here providing a good basis for modeling PhoP-promoter DNA interactions that is crucial to the PhoP-mediated transcriptional regulation., Conclusion: The proven direct PhoP targets include nine genes encoding regulators and 21 genes or operons with functions of detoxification, protection against DNA damages, resistance to antimicrobial peptides, and adaptation to magnesium limitation. We can presume that PhoP is a global regulator that controls a complex regulatory cascade by a mechanism of not only directly controlling the expression of specific genes, but also indirectly regulating various cellular pathways by acting on a set of dedicated regulators. These results help us gain insights into the PhoP-dependent mechanisms by which Y. pestis survives the antibacterial strategies employed by host macrophages.

Background: Environmental modulation of gene expression in Yersinia pestis is critical for its life style and pathogenesis. Using cDNA microarray technology, we have analyzed the global gene expression of this deadly pathogen when grown under different stress conditions in vitro., Results: To provide us with a comprehensive view of environmental modulation of global gene expression in Y. pestis, we have analyzed the gene expression profiles of 25 different stress conditions. Almost all known virulence genes of Y. pestis were differentially regulated under multiple environmental perturbations. Clustering enabled us to functionally classify co-expressed genes, including some uncharacterized genes. Collections of operons were predicted from the microarray data, and some of these were confirmed by reverse-transcription polymerase chain reaction (RT-PCR). Several regulatory DNA motifs, probably recognized by the regulatory protein Fur, PurR, or Fnr, were predicted from the clustered genes, and a Fur binding site in the corresponding promoter regions was verified by electrophoretic mobility shift assay (EMSA)., Conclusion: The comparative transcriptomics analysis we present here not only benefits our understanding of the molecular determinants of pathogenesis and cellular regulatory circuits in Y. pestis, it also serves as a basis for integrating increasing volumes of microarray data using existing methods.