Role of nociceptin systems in learning and memory

This article summarizes our recent finding that the nociceptin system is involved in the regulation of learning and memory. The nociceptin-knockout mice show greater learning ability in the water maze task, an enhanced latent learning in the water finding task, better memory in the passive avoidance task, and further, larger long-term potentiation in the hippocampal CA1 region than wild-type mice. Nociceptin itself induces an impairment of passive avoidance task in wild-type mice, which is reversed by naloxone benzoylhydrazone (NalBzoH). Thus, the nociceptin system seems to play negative roles in learning and memory, and NalBzoH may act as a potent antagonist for the nociceptin receptor.     

Inhibition of angiotensin-converting enzyme protects endothelial cell against hypoxia/reoxygenation injury

Cardiovascular tissue injury in ischemia/reperfusion has been shown to be prevented by angiotensin-converting enzyme (ACE) inhibitors. However, the mechanism on endothelial cells has not been assessed in detail. Cultured human aortic endothelial cells (HAEC) were exposed to hypoxia with or without reoxygenation. Hypoxia enhanced apoptosis along with the activation of caspase-3. Reoxygenation increased lactate dehydrogenase release time-dependently, along with an increase of intracellular oxygen radicals. ACE inhibitor quinaprilat and bradykinin significantly lessened apoptosis and lactate dehydrogenase release with these effects being diminished by a kinin B2 receptor antagonist and a nitric oxide synthase inhibitor. In conclusion, hypoxia activated the suicide pathway leading to apoptosis of HAEC by enhancing caspase-3 activity, while subsequent reoxygenation induced necrosis by enhancing oxygen radical production. Quinaprilat could ameliorate both apoptosis and necrosis through the upregulation of constitutive endothelial nitric oxide synthase via an increase of bradykinin, with the resulting increase of nitric oxide.     

Autocrine/Paracrine secretion of IL-6 family cytokines causes angiotensin II-induced delayed STAT3 activation

We recently reported that angiotensin II (AngII) biphasically activates the JAK/STAT pathway and induces delayed phosphorylation of STAT3 in the late stage (120 min) in cardiomyocytes. This study was designed to determine the mechanism of delayed phosphorylation of STAT3. Conditioned medium prepared from AngII-stimulated cardiomyocytes could reproduce the tyrosine phosphorylation of STAT3 at 5 min. This delayed phosphorylation was almost completely inhibited by anti-gp130 blocking antibody RX435, but not by TAK044 (ET-A/B-R antagonist), prazosin, or propranolol. AngII induced phosphorylation of gp130 in the late stage, which was temporally in parallel with the delayed phosphorylation of STAT3. AngII augmented IL-6, CT-1, and LIF mRNA expression at 30-60 min, but not CNTF expression. AngII increased IL-6 protein levels by 3-fold in the conditioned media at 2 h compared with the control. These findings indicated that AngII-induced delayed activation of STAT3 is caused by autocrine/paracrine secreted IL-6 family cytokines.     

Selection of Orthologous Genes for Construction of a Highly Resolved Phylogenetic Tree and Clarification of the Phylogeny of Trichosporonales Species

The order Trichosporonales (Tremellomycotina, Basidiomycota) includes various species that have clinical, agricultural and biotechnological value. Thus, understanding why and how evolutionary diversification occurred within this order is extremely important. This study clarified the phylogenetic relationships among Tricosporonales species. To select genes suitable for phylogenetic analysis, we determined the draft genomes of 17 Trichosporonales species and extracted 30 protein-coding DNA sequences (CDSs) from genomic data. The CDS regions of Trichosporon asahii and T. faecale were identified by referring to mRNA sequence data since the intron positions of the respective genes differed from those of Cryptococcus neoformans (outgroup) and are not conserved within this order. A multiple alignment of the respective gene was first constructed using the CDSs of T. asahii, T. faecale and C. neoformans, and those of other species were added and aligned based on codons. The phylogenetic trees were constructed based on each gene and a concatenated alignment. Resolution of the maximum-likelihood trees estimated from the concatenated dataset based on both nucleotide (72,531) and amino acid (24,173) sequences were greater than in previous reports. In addition, we found that several genes, such as phosphatidylinositol 3-kinase TOR1 and glutamate synthase (NADH), had good resolution in this group (even when used alone). Our study proposes a set of genes suitable for constructing a phylogenetic tree with high resolution to examine evolutionary diversification in Trichosporonales. These can also be used for epidemiological and biogeographical studies, and may also serve as the basis for a comprehensive reclassification of pleomorphic fungi.     

Is Urinary Lipoarabinomannan the Result of Renal Tuberculosis? Assessment of the Renal Histology in an Autopsy Cohort of Ugandan HIV-Infected Adults

Objective

The detection of urinary lipoarabinomannan (LAM), a mycobacterial cell wall component, is used to diagnose tuberculosis (TB). How LAM enters the urine is not known. To investigate if urinary LAM-positivity is the result of renal TB infection we correlated the outcomes of urinary LAM-antigen testing to renal histology in an autopsy cohort of hospitalized, Ugandan, HIV-infected adults.

Methods

We performed a complete autopsy, including renal sampling, in HIV-infected adults that died during hospitalization after written informed consent was obtained from the next of kin. Urine was collected postmortem through post-mortem catheterisation or by bladder puncture and tested for LAM with both a lateral flow assay (LFA) and an ELISA assay. Two pathologists assessed the kidney histology. We correlated the LAM-assay results and the histology findings.

Results

Of the 13/36 (36%) patients with a positive urinary LAM ELISA and/or LFA, 8/13 (62%) had renal TB. The remaining 5 LAM-positive patients had disseminated TB without renal involvement. Of the 23 LAM-negative patients, 3 had disseminated TB without renal involvement. The remaining LAM-negative patients had no TB infection and died mostly of fungal and bacterial infections. LAM LFA had a sensitivity of 81% and specificity of 100% to diagnose TB at any location, and the LAM ELISA a sensitivity of 63% and a specificity of 100%. 54% (7/13) LAM LFA-positive patients were not on anti-TB treatment at the time of death.

Conclusion

Renal TB infection explained LAM-positivity in the majority of patients. Patients with disseminated TB without renal involvement can also be diagnosed with LAM. This suggests that other mechanisms that lead to urinary LAM-positivity exist in a minority of patients.     

Simultaneous polygyny of the gobiid fish Asterropteryx semipunctata in relation to mate availability

Nesting males of Asterropteryx semipunctata conducted spawning behavior with 2–6 females simultaneously. We carried out field observations on a rocky reef in Kagoshima, Japan, to examine the hypotheses that large males will show multi-female spawning behavior because of their mating advantage, and that simultaneous multi-female spawning will occur when the operational sex ratio (OSR; the ratio of receptive males to receptive females) becomes female-biased. Contrary to our prediction, neither the total number of multi-female spawnings during a spawning season nor mean number of spawning females at a time were correlated with nesting male sizes. This indicates that larger males often did not conduct multi-female spawnings. As predicted, the incidence of multi-female spawning followed the change in the OSR over time—as the OSR in the study area became biased toward females, the incidence of multi-female spawnings gradually increased. Our results suggest that mate availability affects mating patterns in A. semipunctata.     

Genetic analysis of rooting ability of transplanted rice (Oryza sativa L.) under different water conditions

In order to assess the benefits of superior rooting ability of rice (Oryza sativa L.) for growth after transplanting under water-limiting conditions, genetic differences in the rooting ability of rice seedlings 30 d after sowing, with their visible roots either pruned or not pruned, were quantified by several root parameters 4 d after transplanting (DAT), under flooded or non-flooded paddy fields (four treatments in total), together with production traits at maturity. Ninety-eight recombinant inbred lines from the two japonica ecotypes, a lowland variety Otomemochi, and an upland variety Yumenohatamochi, were genotyped with 107 simple sequence repeat (SSR) markers. Otomemochi in general produced more adventitious roots, partitioned a greater proportion of biomass to roots, and had a greater increment of root dry weight (DeltaRW) at 4 DAT than Yumenohatamochi, but these variety differences were less clear under non-flooded conditions without root pruning. Several quantitative trait loci (QTLs) associated with rooting ability were identified mainly in chromosomes 1, 4, and 6 across the four treatments or in combined analysis. On the other hand, QTLs for DeltaRW around RM2357 in chromosome 5 and for maximum new root length in RM215-RM205 in chromosome 9 were found only under root pruning treatments and under non-flooded conditions without root pruning, respectively. Greater DeltaRW was associated with higher head dry weight per hill at maturity only in the non-flooded and root-pruning treatments. This study suggests the importance of rooting ability after transplanting and, possibly, other mechanisms for adaptation to non-flooded conditions.