Selenium status and cardiovascular diseases: meta-analysis of prospective observational studies and randomized controlled trials

BACKGROUND/OBJECTIVES

Selenium was thought to have a role in cardiovascular disease (CVD) owing to its antioxidant properties; however, evidence from observational studies and randomized controlled trials (RCTs) has been inconsistent and controversial. We thus conducted a meta-analysis to assess the discrepancies between observational and randomized trial evidence.

SUBJECTS/METHODS

We searched MEDLINE and EMBASE for eligible prospective studies regarding the relationship between selenium and CVD up to 15 December 2013 and finally included 16 prospective observational studies and 16 RCTs. Random effects model was used to estimate the pooled relative risk (RR). Generalized least-squares trend test and restricted cubic spline model were performed to assess a linear and a nonlinear dose-response relationship.

RESULTS

Our meta-analysis of prospective studies showed a nonlinear relationship of CVD risk with blood selenium concentrations across a range of 30-165 μg/l and a significant benefit of CVD within a narrow selenium range of 55-145 μg/l. Our meta-analyses of RCTs showed that oral selenium supplements (median dose: 200 μg/day) for 2 weeks to 144 months significantly raised the blood selenium concentrations by 56.4 μg/l (95% confidence interval (CI): 40.9, 72.0 μg/l), whereas oral selenium supplements (median: 100 μg/day) for 6 to 114 months caused no effect on CVD (RR=0.91; 95% CI: 0.74, 1.10).

CONCLUSIONS

Our meta-analysis in prospective studies demonstrated a significant inverse association between selenium status and CVD risk within a narrow selenium range and a null effect of selenium supplementation on CVD was observed in RCTs. These findings indicate the importance of considering selenium status, dose and safety in health assessment and future study design.

Critical role of retinoid/rexinoid signaling in mediating transformation and therapeutic response of NUP98-RARG leukemia

While the nucleoporin 98-retinoic acid receptor gamma (NUP98-RARG) is the first RARG fusion protein found in acute leukemia, its roles and the molecular basis in oncogenic transformation are currently unknown. Here, we showed that homodimeric NUP98-RARG not only acquired unique nuclear localization pattern and ability of recruiting both RXRA and wild-type NUP98, but also exhibited similar transcriptional properties as RARA fusions found in acute promyelocytic leukemia (APL). Using murine bone marrow retroviral transduction/transformation assay, we further demonstrated that NUP98-RARG fusion protein had gained transformation ability of primary hematopoietic stem/progenitor cells, which was critically dependent on the C-terminal GLFG domain of NUP98 and the DNA binding domain (DBD) of RARG. In contrast to other NUP98 fusions, cells transformed by the NUP98-RARG fusion were extremely sensitive to all-trans retinoic acid (ATRA) treatment. Interestingly, while pan-RXR agonists, SR11237 and LGD1069 could specifically inhibit NUP98-RARG transformed cells, mutation of the RXR interaction domain in NUP98-RARG had little effect on its transformation, revealing that therapeutic functions of rexinoid can be independent of the direct biochemical interaction between RXR and the fusion. Together, these results indicate that deregulation of the retinoid/rexinoid signaling pathway has a major role and may represent a potential therapeutic target for NUP98-RARG-mediated transformation.

Photoemission study of the electronic structure and charge density waves of Na2Ti2Sb2O

The electronic structure of Na₂Ti₂Sb₂O single crystal is studied by photon energy and polarization dependent angle-resolved photoemission spectroscopy (ARPES). The obtained band structure and Fermi surface agree well with the band structure calculation of Na₂Ti₂Sb₂O in the non-magnetic state, which indicates that there is no magnetic order in Na₂Ti₂Sb₂O and the electronic correlation is weak. Polarization dependent ARPES results suggest the multi-band and multi-orbital nature of Na₂Ti₂Sb₂O. Photon energy dependent ARPES results suggest that the electronic structure of Na₂Ti₂Sb₂O is rather two-dimensional. Moreover, we find a density wave energy gap forms below the transition temperature and reaches 65 meV at 7 K, indicating that Na₂Ti₂Sb₂O is likely a weakly correlated CDW material in the strong electron-phonon interaction regime.

Adenovirus-mediated artificial MicroRNAs targeting matrix or nucleoprotein genes protect mice against lethal influenza virus challenge

Influenza virus (IV) infection is a major public health problem, causing millions of cases of severe illness and as many as 500 000 deaths each year worldwide. Given the limitations of current prevention or treatment of acute influenza, novel therapies are needed. RNA interference (RNAi) through microRNAs (miRNA) is an emerging technology that can suppress virus replication in vitro and in vivo. Here, we describe a novel strategy for the treatment of infuenza based on RNAi delivered by a replication-defective adenovirus (Ad) vector, derived from chimpanzee serotype 68 (AdC68). Our results showed that artificial miRNAs (amiRNAs) specifically targeting conserved regions of the IV genome could effectively inhibit virus replication in human embryonic kidney 293 cells. Moreover, our results demonstrated that prophylactic treatment with AdC68 expressing amiRNAs directed against M1, M2 or nucleoprotein genes of IV completely protected mice from homologous A/PR8 virus challenge and partially protected the mice from heterologous influenza A virus strains such as H9N2 and H5N1. Collectively, our data demonstrate that amiRNAs targeting the conserved regions of influenza A virus delivered by Ad vectors should be pursued as a novel strategy for prophylaxis of IV infection in humans and animals.

Correlation between macrosomia body indices and maternal fasting blood glucose

To explore the significance of neonatal body indices in identifying pathological macrosomia, we implemented a retrospective study of 254 neonates, including: 100 macrosomia of diabetic pregnancies, 77 macrosomia of healthy pregnancies and 77 normal neonates of healthy pregnancies, using their birth weight, body length, head circumference and chest circumference, to calculate neonatal body indices, multiple regression analysis of the correlation between newborn body indices and maternal fasting blood glucose. The Quetelet Index and Kaup Index of diabetic macrosomia is higher than that of non-diabetic macrosomia; HC:CC (ratio between head circumference and chest circumference) is reversed (p < 0.05). The multiple regression equation of neonatal body indices to maternal fasting blood glucose is BG = 6.959 + 0.031 QI -4.482 × HC:CC. Quetelet index and HC:CC have linear relationship with maternal fasting blood glucose (p < 0.05). Compared with birth weight, Quetelet Index and HC:CC could better reflect the effect of maternal metabolism on the fetus and be of great significance in the prediction of fetal macrosomia.

Phosphoglycerate kinase-1 is a predictor of poor survival and a novel prognostic biomarker of chemoresistance to paclitaxel treatment in breast cancer

Background:

Phosphoglycerate kinase-1 (PGK1) has been recently documented in various malignancies; however, the molecular mechanisms of the variable PGK1 expression and its clinical significance in terms of survival status remain unclear.

Methods:

Real-time quantitative PCR (real-time qPCR) and western blotting were used to verify PGK1 expression in 46 fresh breast cancer tissues and matched normal tissues. A tissue microarray (TMA) comprising 401 breast cancer tissues and 123 matched normal tissues was investigated by immunohistochemistry for PGK1 expression. Then, the correlation between PGK1 expression and the clinicopathologic features was analysed.

Results:

PGK1 mRNA and protein expression were significantly increased in breast cancer tissues compared with that in normal breast tissues. High PGK1 expression was significantly associated with higher histologic grade (P=0.009) and positive status of ER (P=0.004), Her-2 (P=0.026) and P53 (P=0.012). High levels of PGK1 expression were associated with worse overall survival (OS, P=0.02). Furthermore, patients who underwent paclitaxel chemotherapy with high levels PGK1 expression had shorter OS than did those with low levels of PGK1 expression (P<0.001). Multivariate analysis indicated that PGK1 (P=0.001) was an independent predictor in the patients treated with paclitaxel.

Conclusions:

PGK1 is a prognostic biomarker of chemoresistance to paclitaxel treatment in breast cancer.

Role of IL-6 polymorphism on the development of cardiovascular events and coronary artery disease in patients receiving hemodialysis

We aimed to investigate the role of IL-6 polymorphism on the development of cardiovascular events and coronary artery disease in patients receiving hemodialysis. Blood samples were collected from 216 patients receiving hemodialysis treatment. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to genotype IL-6 -634C/G, -174G/C and -572C/G. By multivariate analysis, we found that the IL-6 -634GG genotype was associated with increased risk of cardiovascular events in patients receiving hemodialysis, with HR (95%CI) of 4.07 (1.20-15.70). Similarly, we found that the IL-6-174CC genotype was related to the onset and development of cardiovascular events in patients receiving hemodialysis, with HR (95%CI) of 3.33 (1.21-9.51). However, we did not find an association between IL-6 -572C/G polymorphism and risk of cardiovascular events in patients receiving hemodialysis.

Effect of Antimuscarinic Autoantibodies in Primary Sjögren's Syndrome

The presence of functional autoantibodies against the muscarinic type 3 receptor (M3R) has been reported in primary Sjögren's syndrome (pSS). However, the pathogenic role of these autoantibodies in pSS development remains to be elucidated. In this experiment, we investigated a pathologic role of pSS autoantibodies (pSS IgG) associated with downregulation of the major histocompatibility complex I (MHC I) molecule with M3R through internalization. Anti-M3R autoantibodies in purified control and pSS IgG were detected using 4 synthesized cyclic M3R peptides by enzyme-linked immunosorbent assay. The binding reactivity of pSS IgG to M3R in situ was analyzed by a dual immunostaining method. Surface expression, interaction, and internalization of M3R with MHC I were analyzed by immunofluorescence confocal microscopy and biochemical assays. Synthetic cyclic peptides M3RP(205-221) and M3RP(520-527) showed significantly high reactivity with pSS IgG compared to the control IgG or the other 3 peptides (P < 0.05). Significantly high reactivity of pSS IgG to M3R in situ was observed. PSS IgG increased the interaction of membrane M3R with MHC I and induced their internalization in primary human submandibular gland cells. The pSS IgG-induced internalization of M3R with MHC I was significantly inhibited by the cholesterol-sequestering drug filipin. Our novel finding-namely, strong downregulation of the membrane MHC I with M3R through internalization of the cholesterol-rich microdomain associating with anti-M3R autoantibodies-could be an important mechanism contributing to the impaired salivation seen in pSS and linking secretory hypofunction to autoimmune pathogenesis.

The distribution of kisspeptin (Kiss)1- and Kiss2-positive neurones and their connections with gonadotrophin-releasing hormone-3 neurones in the zebrafish brain

Kisspeptin is a neuroendocrine hormone with a critical role in the activation of gonadotrophin-releasing hormone (GnRH) neurones, which is vital for the onset of puberty in mammals. However, the functions of kisspeptin neurones in non-mammalian vertebrates are not well understood. We have used transgenics to labell kisspeptin neurones (Kiss1 and Kiss2) with mCherry in zebrafish (Danio rerio). In kiss1:mCherry transgenic zebrafish, Kiss1 cells were located in the dorsomedial and ventromedial habenula, with their nerve fibres contributing to the fasciculus retroflexus and projecting to the ventral parts of the interpeduncular and raphe nuclei. In kiss2:mCherry zebrafish, Kiss2 cells were primarily located in the dorsal zone of the periventricular hypothalamus and, to a lesser extent, in the periventricular nucleus of the posterior tuberculum and the preoptic area. Kiss2 fibres formed a wide network projecting into the telencephalon, the mesencephalon, the hypothalamus and the pituitary. To study the relationship of kisspeptin neurones and GnRH3 neurones, these fish were crossed with gnrh3:EGFP zebrafish to obtain kiss1:mCherry/gnrh3:EGFP and kiss2:mCherry/gnrh3:EGFP double transgenic zebrafish. The GnRH3 fibres ascending to the habenula were closely associated with Kiss1 fibres projecting from the ventral habenula. On the other hand, GnRH3 fibres and Kiss2 fibres were adjacent but scarcely in contact with each other in the telencephalon and the hypothalamus. The Kiss2 and GnRH3 fibres in the ventral hypothalamus projected into the pituitary via the pituitary stalk. In the pituitary, Kiss2 fibres were directly in contact with GnRH3 fibres in the pars distalis. These results reveal the pattern of kisspeptin neurones and their connections with GnRH3 neurones in the brain, suggesting distinct mechanisms for Kiss1 and Kiss2 in regulating reproductive events in zebrafish.

Role of pentose phosphate pathway in lipid accumulation of oleaginous fungus Mucor circinelloides

Overexpressing the genes coding for glucose 6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase from the pentose phosphate pathway in the oleaginous fungusMucor circinelloidesincreased the lipid content of cell dry weight by 20–30%.