Large scale isolation and some properties of AGY-specific serine tRNA from bovine heart mitochondria

A method was developed for large scale isolation of AGY-specific serine tRNA (tRNASerAGY) from bovine heart mitochondria. By this method, 5 A260 units of tRNASerAGY were recovered from 6.3 kg of bovine hearts. The nucleotide sequence was identical to that reported previously. tRNASerAGY showed abnormal melting profiles, as was predicted from its unique primary sequence. Its secondary and/or tertiary structure was analyzed by nuclease digestion method. It was suggested that three extra base pairs could occur in the anticodon stem region, with one adenosine residue protruding. The T loop was quite sensitive to nuclease S1, suggesting that the T loop doesn't interact with other regions. This finding is consistent with the model proposed by Sundaralingam (1980). tRNASerAGY was aminoacylated in vitro with only mitochondrial enzyme but not with the enzymes from E. coli and yeast. The aminoacylation rate of tRNASerAGY with mitochondrial enzyme was much faster than that of cytosolic tRNASerUCN, perhaps reflecting differences due to the presence and absence of the D arm of the tRNAs.     

Comparative Studies on Large- and Small-Plaque-Forming Clones of Newcastle Disease Virus (Miyadera Strain)

The Miyadera strain of Newcastle disease virus (NDV) consisted predominantly of virus particles forming small plaques on monolayers of chick embryo fibroblasts (CEF), and contained small amounts of virus particles forming large plaques. These large- and small-plaque-forming clones of this virus (NDV-L and NDV-S) were isolated. The small size of the NDV-S plaques did not appear to be due to an agar inhibitor. NDV-L produced a much higher yield of infective virus particles in CEF and they were released more completely from the infected cells than were those produced by NDV-S. The yield of infective virus of NDV-L per cell from cultures of CEF was comparable to the yield from the allantoic cells. The infectivity/hemagglutinin ratio for NDV-L from CEF was as high as the ratio for virus from the allantoic cells, but the ratio for NDV-S from CEF was lower. NDV-S demonstrated an autointerference phenomenon in CEF when infected at high multiplicities, but NDV-L did not. Contrary to virus multiplication, NDV-S exhibited a more rapid and marked cytopathic effect on monolayers of CEF than NDV-L. In the allantoic cavity of eggs NDV-S produced slightly higher virus yields than NDV-L. No correlation existed between plaque size of the two viruses and the capacity to induce interferon synthesis or the susceptibility to the action of interferon. The properties of both distinctive plaque isolates were stable on egg passage.     

TRIM37 prevents formation of condensate-organized ectopic spindle poles to ensure mitotic fidelity

Centrosomes are composed of a centriolar core surrounded by pericentriolar material that nucleates microtubules. The ubiquitin ligase TRIM37 localizes to centrosomes, but its centrosomal roles are not yet defined. We show that TRIM37 does not control centriole duplication, structure, or the ability of centrioles to form cilia but instead prevents assembly of an ectopic centrobin-scaffolded structured condensate that forms by budding off of centrosomes. In ∼25% of TRIM37-deficient cells, the condensate organizes an ectopic spindle pole, recruiting other centrosomal proteins and acquiring microtubule nucleation capacity during mitotic entry. Ectopic spindle pole–associated transient multipolarity and multipolar segregation in TRIM37-deficient cells are suppressed by removing centrobin, which interacts with and is ubiquitinated by TRIM37. Thus, TRIM37 ensures accurate chromosome segregation by preventing the formation of centrobin-scaffolded condensates that organize ectopic spindle poles. Mutations in TRIM37 cause the disorder mulibrey nanism, and patient-derived cells harbor centrobin condensate-organized ectopic poles, leading us to propose that chromosome missegregation is a pathological mechanism in this disorder.     

Ribosome induces transdifferentiation of A549 and H-111-TC cancer cell lines

Previously we reported that, lactic acid bacteria (LAB) can induce human dermal fibroblast (HDF) cells to form multipotent cell clusters which are able to transdifferentiate into three germ layer derived cell lineages. Later on, we confirmed that ribosome is responsible for the LAB-induced transdifferentiation and ribosomes from diverse organisms can mimic the LAB effect on HDF cells. In our present study we have shown that, upon incorporation of ribosomes, non-small cell lung cancer cell line A549 and gastric tubular adenocarcinoma cell line H-111-TC are transformed into spheroid like morphology those can be transdifferentiated into adipocytes and osteoblast. Our qPCR analysis has revealed that, during the formation of ribosome induced cancer cell spheroids, the expression of the cancer cell associated markers and cell cycle/proliferation markers were altered at different time point. Through our investigation, here we report a novel and a non-invasive approach for cancer cell reprogramming by incorporating ribosomes.     

Predation on symbiont sea anemones by their host hermit crab Dardanus pedunculatus

Feeding by host hermit crabs Dardanus pedunculatus on their symbiotic sea anemones Calliactis polypus was investigated using animals collected at Shirahama, Wakayama Prefecture, Japan. In the first experiment, changes in the number of sea anemones on hermit crab shells were recorded in single‐and double‐crab trials without food and single‐crab trials with food. The number of sea anemones significantly decreased under starved conditions. The extent of this decrease per single hermit crab was higher in the double‐crab trials than in the single‐crab trials. Direct observations and video recordings showed that hermit crabs occasionally removed sea anemones from their own shells, and also from partners’ shells in the double‐crab trials, and consumed them. In the second experiment, fed and unfed hermit crabs with or without sea anemones were examined for body weight changes. Fed hermit crabs gained weight whereas unfed hermit crabs lost it. The degree of weight loss in unfed hermit crabs was significantly higher in those without sea anemones, which indicates some value of the latter as food. We offer some speculations on the course of development of this symbiosis, with predation on sea anemones having played an important initial role.     

Experimental Verification of the Effects on Normal Domestic Cats by Feeding Prescription Diet for Decreasing Stress

The objective of this study was to evaluate the effects of diet on the feline stress response by measuring plasma and urinary cortisol. A study diet was developed with a unique combination of nutrients that supports the management of stressful situations. The specific formulation of the diet included alpha-casozepine, which is believed to have an anxiolytic effect, and tryptophan supplementation. Tryptophan is the precursor for the synthesis of the neurotransmitter serotonin. Twenty-one indoor cats were fed with the study diet (n = 10) or a control diet (n = 11) for 8 weeks, after which physiological responses were evaluated. The study diet significantly increased the ratio of plasma tryptophan to large neutral amino acids and decreased urinary cortisol concentrations after being consumed daily for 8 weeks, but there was no effect on plasma cortisol levels following a stressful event (veterinary examination and blood draw). Further studies, such as behavioral analyses, are needed to clarify the effects of the study diet.     

Role of the prosthetic groups of NADPH-cytochrome P450 reductase in 3-hydroxyanthranilamide-catalyzed,NADPH-dependent superoxide anion production

Summary

The role of the prosthetic groups (FAD and FMN) of NADPH-cytochrome P450 reductase (P450 reductase)in 3-hydroxyanthranilamide (3-OH An.Amide)-catalyzed, NADPH-dependent superoxide anion (O₂-) production via the reductase was examined using the native and FMN-depleted preparations of P450 reductase which was partially purified from rat liver microsomes. NADPH-dependent O₂-production by the FMN-depleted preparation was about 10% of that by the native preparation. 3-OH An. Amide-catalyzed, NADPH-dependent O₂-production by the FMN-depleted preparation was less than 10% of that by the native preparation. FMN supplementation returned O₂-production to near normal. We observed the same results for NADPH oxidation and hydrogen peroxide formation. O₂-production, NADPH oxidation, and hydrogen peroxide formation were inhibited by native superoxide dismutase (SOD), but not by boiled, denatured SOD. These results indicate that the prosthetic groups, especially FMN, of P450 reductase play a critical role in 3-OH An.Amide-catalyzed, NADPH-dependent O₂-production via the reductase.     

Thermophilic and halophilic β-agarase from a halophilic archaeon Halococcus sp. 197A

An agar-degrading archaeon Halococcus sp. 197A was isolated from a solar salt sample. The agarase was purified by hydrophobic column chromatography using a column of TOYOPEARL Phenyl-650 M. The molecular mass of the purified enzyme, designated as Aga-HC, was ~55 kDa on both SDS-PAGE and gel-filtration chromatography. Aga-HC released degradation products in the order of neoagarohexose, neoagarotetraose and small quantity of neoagarobiose, indicating that Aga-HC was a β-type agarase. Aga-HC showed a salt requirement for both stability and activity, being active from 0.3 M NaCl, with maximal activity at 3.5 M NaCl. KCl supported similar activities as NaCl up to 3.5 M, and LiCl up to 2.5 M. These monovalent salts could not be substituted by 3.5 M divalent cations, CaCl₂ or MgCl₂. The optimal pH was 6.0. Aga-HC was thermophilic, with optimum temperature of 70 °C. Aga-HC retained approximately 90 % of the initial activity after incubation for 1 hour at 65–80 °C, and retained 50 % activity after 1 hour at 95 °C. In the presence of additional 10 mM CaCl₂, approximately 17 % remaining activity was detected after 30 min at 100 °C. This is the first report on agarase purified from Archaea.     

Plasma B-type Natriuretic Peptide as a Predictor of Cardiovascular Events in Subjects with Atrial Fibrillation: A Community-Based Study

Objectives

Atrial fibrillation (AF) is a significant public health issue due to its high prevalence in the general population, and is associated with an increased risk of cardiovascular (CV) events including systemic thrombo-embolism, heart failure, and coronary artery disease. The relationship between plasma B-type natriuretic peptide (BNP) and CV risk in real world AF subjects remains unknown.

Methods

The subject of the study (n = 228; mean age = 69 years) was unselected individuals with AF in a community-based population (n = 15,394; AF prevalence rate = 1.5%). The CV event free rate within each BNP tertile was estimated, and Cox regression analysis was performed to examine the relative risk of the onset of CV events among the tertiles. The prognostic ability of BNP was compared to an established risk score for embolic events (CHADS2 score). In addition, to determine the usefulness of BNP as a predictor in addition to CHADS2 score, we calculated Net Reclassification Improvement (NRI) and Integrated Discrimination Improvement (IDI) indices.

Results

During the follow-up period 58 subjects experienced CV events (52 per 1,000 person-years). The event-free ratio was significantly lower in the highest tertile (p < 0.02). After adjustment for established CV risk factors, the hazard ratio (HR) of the highest tertile was significantly higher than that of the lowest tertile (HR = 2.38; p < 0.02). The predictive abilities of plasma BNP in terms of sensitivity and specificity for general CV events were comparable to those of CHADS2 score. Adding BNP to the CHADS2 score only model improved the NRI (0.319; p < 0.05) and the IDI (0.046; p < 0.05).

Conclusion

Plasma BNP is a valuable biomarker both singly or in combination with an established scoring system for assessing general CV risk including stroke, heart failure and acute coronary syndrome in real-world AF subjects.