Diversification processes of teleost intron-less opsin genes

Opsins are universal photosensitive proteins in animals. Vertebrates have a variety of opsin genes for visual and non-visual photoreceptions. Analysis of the gene structures shows that most opsin genes have introns in their coding regions. However, teleosts exceptionally have several intron-less opsin genes which are presumed to have been duplicated by an RNA-based gene duplication mechanism, retroduplication. Among these retrogenes, we focused on the Opn4 (melanopsin) gene responsible for non-image-forming photoreception. Many teleosts have five Opn4 genes including one intron-less gene, which is speculated to have been formed from a parental intron-containing gene in the Actinopterygii. In this study, to reveal the evolutionary history of Opn4 genes, we analyzed them in teleost (zebrafish and medaka) and non-teleost (bichir, sturgeon and gar) fishes. Our synteny analysis suggests that the intron-less Opn4 gene emerged by retroduplication after branching of the bichir lineage. In addition, our biochemical and histochemical analyses showed that, in the teleost lineage, the newly acquired intron-less Opn4 gene became abundantly used without substantial changes of the molecular properties of the Opn4 protein. This stepwise evolutionary model of Opn4 genes is quite similar to that of rhodopsin genes in the Actinopterygii. The unique acquisition of rhodopsin and Opn4 retrogenes would have contributed to the diversification of the opsin gene repertoires in the Actinopterygii and the adaptation of teleosts to various aquatic environments

Efficacy and Safety of Three-dimensional Conformal Radiotherapy for Macroscopic Vascular Invasion of Hepatocellular Carcinoma

Chemotherapy is insufficient to treat macroscopic vascular invasion (MVI) of hepatocellular carcinoma (HCC). We retrospectively investigated the treatment outcomes of patients who underwent three-dimensional conformal radiotherapy (3D-CRT) for HCC MVI and analyzed prognostic factors by multivariate analysis using a Cox proportional hazard model. Sixty-five patients were studied. MVI sites were the portal vein (n=48 patients), portal and hepatic veins (n=8), and hepatic vein (n=9). The median irradiation dose was 50 Gy. The median survival time (MST) was 7.5 months. Performance status 2 or 3, modified albumin-bilirubin grade 2b or 3, and massive/diffuse type were poor prognostic factors. Nineteen patients (29%) with a treatment effect of 3 or 4 (≥ 50% of tumor necrosis or regression) at the irradiation sites according to the Response Evaluation Criteria in Cancer of the Liver showed longer survival than those with an effect of 1 or 2 (MST 18.7 vs. 5.9 months, p<0.001). No treatment-related death occurred. The hepatic function reserve was preserved in more than 70% of patients. 3D-CRT controlled HCC MVI safely and was suggested to be a good treatment option

New host record for three scuttle flies, Megaselia flava, M. kanekoi and M. gotoi (Diptera: Phoridae), on the poisonous fungus Amanita ibotengutake (Agaricales: Amanitaceae)

金沢大学理工研究域　自然システム学

Polaprezinc Protects Mice against Endotoxin Shock

Polaprezinc (PZ), a chelate compound consisting of zinc and l-carnosine (Car), is an anti-ulcer drug developed in Japan. In the present study, we investigated whether PZ suppresses mortality, pulmonary inflammation, and plasma nitric oxide (NO) and tumor necrosis factor (TNF)-α levels in endotoxin shock mice after peritoneal injection of lipopolysaccharide (LPS), and how PZ protects against LPS-induced endotoxin shock. PZ pretreatment inhibited the decrease in the survival rate of mice after LPS injection. PZ inhibited the increases in plasma NO as well as TNF-α after LPS. Compatibly, PZ suppressed LPS-induced inducible NO synthase mRNA transcription in the mouse lungs. PZ also improved LPS-induced lung injury. However, PZ did not enhance the induction of heat shock protein (HSP) 70 in the mouse lungs after LPS. Pretreatment of RAW264 cells with PZ suppressed the production of NO and TNF-α after LPS addition. This inhibition likely resulted from the inhibitory effect of PZ on LPS-mediated nuclear factor-κB (NF-κB) activation. Zinc sulfate, but not Car, suppressed NO production after LPS. These results indicate that PZ, in particular its zinc subcomponent, inhibits LPS-induced endotoxin shock via the inhibition of NF-κB activation and subsequent induction of proinflammatory products such as NO and TNF-α, but not HSP induction

Generation of Tetrafluoroethylene–Propylene Elastomer-Based Microfluidic Devices for Drug Toxicity and Metabolism Studies

フッ素系エラストマー素材を用いた肝臓チップの開発と薬物代謝・毒性試験への応用. 京都大学プレスリリース. 2021-09-16.Drug testing on miniatured livers. 京都大学プレスリリース. 2021-09-17.Polydimethylsiloxane (PDMS) is widely used to fabricate microfluidic organs-on-chips. Using these devices (PDMS-based devices), the mechanical microenvironment of living tissues, such as pulmonary respiration and intestinal peristalsis, can be reproduced in vitro. However, the use of PDMS-based devices in drug discovery research is limited because of their extensive absorption of drugs. In this study, we investigated the feasibility of the tetrafluoroethylene–propylene (FEPM) elastomer to fabricate a hepatocyte-on-a-chip (FEPM-based hepatocyte chip) with lower drug absorption. The FEPM-based hepatocyte chip expressed drug-metabolizing enzymes, drug-conjugating enzymes, and drug transporters. Also, it could produce human albumin. Although the metabolites of midazolam and bufuralol were hardly detected in the PDMS-based hepatocyte chip, they were detected abundantly in the FEPM-based hepatocyte chip. Finally, coumarin-induced hepatocyte cytotoxicity was less severe in the PDMS-based hepatocyte chip than in the FEPM-based hepatocyte chip, reflecting the different drug absorptions of the two chips. In conclusion, the FEPM-based hepatocyte chip could be a useful tool in drug discovery research, including drug metabolism and toxicity studies

Structure of the dopamine D2 receptor in complex with the antipsychotic drug spiperone

統合失調症に関わるドパミン受容体の構造解明 --副作用を抑えた薬の迅速な探索・設計が可能に--. 京都大学プレスリリース. 2020-12-24.In addition to the serotonin 5-HT2A receptor (5-HT2AR), the dopamine D2 receptor (D2R) is a key therapeutic target of antipsychotics for the treatment of schizophrenia. The inactive state structures of D2R have been described in complex with the inverse agonists risperidone (D2Rris) and haloperidol (D2Rhal). Here we describe the structure of human D2R in complex with spiperone (D2Rspi). In D2Rspi, the conformation of the extracellular loop (ECL) 2, which composes the ligand-binding pocket, was substantially different from those in D2Rris and D2Rhal, demonstrating that ECL2 in D2R is highly dynamic. Moreover, D2Rspi exhibited an extended binding pocket to accommodate spiperone’s phenyl ring, which probably contributes to the selectivity of spiperone to D2R and 5-HT2AR. Together with D2Rris and D2Rhal, the structural information of D2Rspi should be of value for designing novel antipsychotics with improved safety and efficacy

Mercury concentrations in primary feathers reflect pollutant exposure in discrete non-breeding grounds used by Short-tailed Shearwaters

We measured mercury concentrations ([Hg]) and nitrogen stable isotope ratios (δ15N) in the primary feathers of Short-tailed Shearwaters (Puffinus tenuirostris) that were tracked year-round. The [Hg] were highest in 14 birds that used the Okhotsk and northern Japan Seas during the non-breeding period (2.5 ± 1.4 μg/g), lowest in nine birds that used the eastern Bering Sea (0.8 ± 0.2 μg/g), and intermediate in five birds that used both regions (1.0 ± 0.5 μg/g), with no effects of δ15N. The results illustrate that samples from seabirds can provide a useful means of monitoring pollution at a large spatial scale

Translocator protein imaging with 18F-FEDAC-positron emission tomography in rabbit atherosclerosis and its presence in human coronary vulnerable plaques

Background and aims: This study aimed to investigate whether N-benzyl-N-methyl-2-[7,8-dihydro-7-(2-[18F]fluoroethyl)-8-oxo-2-phenyl-9H-purin-9-yl]acetamide (18F-FEDAC), a probe for translocator protein (TSPO), can visualize atherosclerotic lesions in rabbits and whether TSPO is localized in human coronary plaques.Methods: 18F-FEDAC-PET of a rabbit model of atherosclerosis induced by a 0.5% cholesterol diet and ballooninjury of the left carotid artery (n = 7) was performed eight weeks after the injury. The autoradiography intensity of 18F-FEDAC in carotid artery tissue sections was measured, and TSPO expression was evaluated immunohistochemically.TSPO expression was examined in human coronary arteries obtained from autopsy cases (n = 16), and in human coronary plaques (n = 12) aspirated from patients with acute myocardial infarction (AMI).Results: 18F-FEDAC-PET visualized the atherosclerotic lesions in rabbits as high-uptake areas, and the standard uptake value was higher in injured arteries (0.574 ± 0.24) than in uninjured arteries (0.277 ± 0.13, p < 0.05) or myocardium (0.189 ± 0.07, p < 0.05). Immunostaining showed more macrophages and more TSPO expression in atherosclerotic lesions than in uninjured arteries. TSPO was localized in macrophages, and arterial autoradiography intensity was positively correlated with macrophage concentration (r = 0.64) and TSPO (r = 0.67). TSPO expression in human coronary arteries was higher in AMI cases than in non-cardiac death, or in the vulnerable plaques than in early or stable lesions, respectively. TSPO was localized in macrophages in all aspirated coronary plaques with thrombi.Conclusions: 18F-FEDAC-PET can visualize atherosclerotic lesions, and TSPO-expression may be a marker of highrisk coronary plaques