Redox state of albumin affects its lipid mediator binding characteristics

Depending on its redox status, albumin is known to exist as two forms: reduced albumin or human mercaptalbumin (HMA); and oxidised albumin or human nonmercaptalbumin (HNA). The ratio of HNA to HMA is reportedly elevated in several diseases. Since lipid mediators, such as eicosanoids and lysophospholipids, are typically bound to albumin, we examined the possible preferences of lipid mediators for HNA or HMA. We observed that DHA-derived and EPA-derived eicosanoids preferred to be bound to HMA, while the levels of lysophospholipid mediators, such as lysophosphatidic acids and sphingosine 1-phosphate, were higher in the HNA fraction. Considering the bioactivities reported in previous basic studies, these results suggest that proatherosclerotic lipid mediators might generally prefer HNA, while antiatherosclerotic ones might prefer HMA. Oxidative stress affects the redox status of albumin, which might modulate the dynamism of lipid mediators. This pathway might be partly involved in the association between oxidation and atherosclerosis.     

Global overexpression of divalent metal transporter 1 delays crocidolite-induced mesothelial carcinogenesis in male mice

Abstract

Exposure to asbestos fiber is central to mesothelial carcinogenesis, for which iron overload in or near mesothelial cells is a key pathogenic mechanism. Alternatively, iron chelation therapy with deferasirox or regular phlebotomy was significantly preventive against crocidolite-induced mesothelial carcinogenesis in rats. However, the role of iron transporters during asbestos-induced carcinogenesis remains elusive. Here, we studied the role of divalent metal transporter 1 (DMT1; Slc11a2), which is a Fe(II) transporter, that is present not only on the apical plasma membrane of duodenal cells but also on the lysosomal membrane of every cell, in crocidolite-induced mesothelial carcinogenesis using DMT1 transgenic (DMT1Tg) mice. DMT1Tg mice show mucosal block of iron absorption without cancer susceptibility under normal diet. We unexpectedly found that superoxide production was significantly decreased upon stimulation with crocidolite both in neutrophils and macrophages of DMT1Tg mice, and the macrophage surface revealed higher iron content 1?h after contact with crocidolite. Intraperitoneal injection of 3?mg crocidolite ultimately induced malignant mesothelioma in ～50% of both wild-type and DMT1Tg mice (23/47 and 14/28, respectively); this effect was marginally (p?=?0.069) delayed in DMT1Tg mice, promoting survival. The promotional effect of nitrilotriacetic acid was limited, and the liver showed significantly higher iron content both in DMT1Tg mice and after crocidolite exposure. The results indicate that global DMT1 overexpression causes decreased superoxide generation upon stimulation in inflammatory cells, which presumably delayed the promotional stage of crocidolite-induced mesothelial carcinogenesis. DMT1Tg mice with low-stamina inflammatory cells may be helpful to evaluate the involvement of inflammation in various pathologies.     

Inhibition of HCV Replication in HCV Replicon by shRNAs

We show that the vector-derived long dsRNA specifically inhibits the replication of HCV RNA in HCV replicon. We designed a long dsRNA targeted to the full-length HCV IRES/core elements (1-to 377-nt). Our results revealed that the replication of HCV RNA was reduced to near background levels in a sequence-specific manner by the long dsRNAs in the HCV replicon. We also designed four shRNAs against several regions (120- to 139-nt, 260- to 279-nt, 330- to 349-nt, and 340- to 359-nt) of the HCV IRES/Core elements. The two HCV IRES/core-specific shRNAs, 330- to 349-nt and 340- to 359-nt, containing the AUG initiation codon sequence showed stronger HCV inhibitory effects than the other two shRNAs, 120- to 139-nt and 260- to 279-nt.     

Optimization of a Method for Chromatin Immunoprecipitation Assays in the Marine Invertebrate Chordate Ciona

Chromatin immunoprecipitation (ChIP) assays allow the efficient characterization of the in vivo occupancy of genomic regions by DNA-binding proteins and thus facilitate the prediction of cis-regulatory sequences in silico and guide their validation in vivo. For these reasons, these assays and their permutations (e.g., ChIP-on-chip and ChIP-sequencing) are currently being extended to several non-mainstream model organisms, as the availability of specific antibodies increases. Here, we describe the development of a polyclonal antibody against the Brachyury protein of the marine invertebrate chordate Ciona intestinalis and provide a detailed ChIP protocol that should be easily adaptable to other marine organisms.     

Epidemiological Characterization of Influenza A(H1N1)pdm09 Cases from 2009 to 2010 in Baguio City,the Philippines

Background

Baguio City, Philippines experienced its first influenza A(H1N1)pdm09 [A(H1)pdm09] case in May 2009. In spite of numerous reports describing the epidemiological and clinical features of A(H1)pdm09 cases, there are no studies about A(H1)pdm09 epidemiology in the Philippines, where year-round influenza activity was observed.

Objectives

We aimed to investigate the epidemiological and clinical features of A(H1)pdm09 in pandemic and post-pandemic periods.

Methods

Data were collected under enhanced surveillance of influenza-like illness (ILI) and severe acute respiratory infection (SARI) from January 2009 to December 2010. RT-PCR was used to detect A(H1)pdm09, following the protocol of the United States Centers for Disease Control and Prevention. The reproduction number was computed as a simple exponential growth rate. Differences in proportional and categorical data were examined using chi-square test or Fishers’ exact test.

Results and Conclusions

The outbreak was observed from week 25 to 35 in 2009 and from week 24 to 37 in 2010. The highest proportion of cases was among children aged 5–14 years. The number of ILI outpatients was 2.3-fold higher in 2009 than in 2010, while the number of inpatients was 1.8-fold higher in 2009. No significant difference in gender was observed during the two periods. The clinical condition of all patients was generally mild and self-limiting, with only 2 mortalities among inpatients in 2009. The basic reproduction number was estimated as 1.16 in 2009 and 1.05 in 2010 in the assumption of mean generation time as 2.6 days. School children played a significant role in facilitating influenza transmission.     

Synthesis of Very-Long-Chain Fatty Acids in the Epidermis Controls Plant Organ Growth by Restricting Cell Proliferation

Plant organ growth is controlled by inter-cell-layer communication, which thus determines the overall size of the organism. The epidermal layer interfaces with the environment and participates in both driving and restricting growth via inter-cell-layer communication. However, it remains unknown whether the epidermis can send signals to internal tissue to limit cell proliferation in determinate growth. Very-long-chain fatty acids (VLCFAs) are synthesized in the epidermis and used in the formation of cuticular wax. Here we found that VLCFA synthesis in the epidermis is essential for proper development of Arabidopsis thaliana. Wild-type plants treated with a VLCFA synthesis inhibitor and pasticcino mutants with defects in VLCFA synthesis exhibited overproliferation of cells in the vasculature or in the rib zone of shoot apices. The decrease of VLCFA content increased the expression of IPT3, a key determinant of cytokinin biosynthesis in the vasculature, and, indeed, elevated cytokinin levels. These phenotypes were suppressed in ipt3;5;7 triple mutants, and also by vasculature-specific expression of cytokinin oxidase, which degrades active forms of cytokinin. Our results imply that VLCFA synthesis in the epidermis is required to suppress cytokinin biosynthesis in the vasculature, thus fine-tuning cell division activity in internal tissue, and therefore that shoot growth is controlled by the interaction between the surface (epidermis) and the axis (vasculature) of the plant body.     

Vertical Distribution and Estimated Doses from Artificial Radionuclides in Soil Samples around the Chernobyl Nuclear Power Plant and the Semipalatinsk Nuclear Testing Site

For the current on-site evaluation of the environmental contamination and contributory external exposure after the accident at the Chernobyl Nuclear Power Plant (CNPP) and the nuclear tests at the Semipalatinsk Nuclear Testing Site (SNTS), the concentrations of artificial radionuclides in soil samples from each area were analyzed by gamma spectrometry. Four artificial radionuclides (²⁴¹Am, ¹³⁴Cs, ¹³⁷Cs, and ⁶⁰Co) were detected in surface soil around CNPP, whereas seven artificial radionuclides (²⁴¹Am, ⁵⁷Co, ¹³⁷Cs, ⁹⁵Zr, ⁹⁵Nb, ⁵⁸Co, and ⁶⁰Co) were detected in surface soil around SNTS. Effective doses around CNPP were over the public dose limit of 1 mSv/y (International Commission on Radiological Protection, 1991). These levels in a contaminated area 12 km from Unit 4 were high, whereas levels in a decontaminated area 12 km from Unit 4 and another contaminated area 15 km from Unit 4 were comparatively low. On the other hand, the effective doses around SNTS were below the public dose limit. These findings suggest that the environmental contamination and effective doses on the ground definitely decrease with decontamination such as removing surface soil, although the effective doses of the sampling points around CNPP in the present study were all over the public dose limit. Thus, the remediation of soil as a countermeasure could be an extremely effective method not only for areas around CNPP and SNTS but also for areas around the Fukushima Dai-ichi Nuclear Power Plant (FNPP), and external exposure levels will be certainly reduced. Long-term follow-up of environmental monitoring around CNPP, SNTS, and FNPP, as well as evaluation of the health effects in the population residing around these areas, could contribute to radiation safety and reduce unnecessary exposure to the public.     

Basal and Ischemia-Induced Transcardiac Troponin Release into the Coronary Circulation in Patients with Suspected Coronary Artery Disease

Background

Cardiac troponin is a specific biomarker for cardiomyocyte necrosis in acute coronary syndromes. Troponin release from the coronary circulation remains to be determined because of the lower sensitivity of the conventional assay. We sought to determine basal and angina-induced troponin release using a highly sensitive troponin assay.

Methods and Results

The cardiac troponin T levels in serum sampled from the peripheral vein (PV), the aortic root (AO), and the coronary sinus (CS) were measured in 105 consecutive stable patients with coronary risk factor(s) and suspected coronary artery disease (CAD) and in 33 patients without CAD who underwent an acetylcholine provocation test. At baseline, there was a significant increase in the troponin levels from AO [9.0 (6.4, 13.1) pg/mL for median (25^th, 75^th percentiles)] to CS [10.3 (7.3, 15.5) pg/mL, p<0.001] in 96 (91.4%) patients and the difference was 1.1 (0.4, 2.1) pg/mL, which reflected basal transcardiac troponin release (TTR). TTR was positively correlated with PV levels (r = 0.22, p = 0.03). Male sex, left ventricular hypertrophy determined by echocardiography, T-wave inversion, and CAD correlated with elevated TTR defined as above: median, 1.1 pg/mL. A significant increase in TTR was noted in 17 patients with coronary spasms [0.6 (0.2, 1.2) pg/mL, p<0.01] but not in 16 patients without spasms [0.0 (−0.5, 0.9) pg/mL, p = 0.73] after the acetylcholine provocation.

Conclusion

Basal TTR in the coronary circulation was observed in most of the patients with suspected CAD and risk factor(s). This sensitive assay detected myocardial ischemia-induced increases in TTR caused by coronary spasms.