84 research outputs found

    Regulation of energy metabolism by interleukin-1 β, but not by interleukin-6, is mediated by nitric oxide in primary cultured rat hepatocytes

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    AbstractThe effects of inflammatory cytokines (interleukin-1 β, interleukin-6, and tumor necrosis factor-α) on energy metabolism were studied in primary cultured rat hepatocytes. Adenine nucleotide (ATP, ADP, and AMP) content, lactate production, the ketone body ratio (acetoacetate/β-hydroxybutyrate) reflecting the liver mitochondrial redox state (NAD+/NADH), and nitric oxide formation were measured. Insulin increased ATP content in hepatocytes and had a maximal effect after 8–12 h of culture. Both interleukin-1β and interleukin-6, but not tumor necrosis factor-α, significantly inhibited the ATP increase time- and dose-dependently. Interleukin-1β and interleukin-6 also stimulated lactate production. During the same period, interleukin-1 β but not interleukin-6 decreased the ketone body ratio. Furthermore, interleukin-1 β markedly stimulated nitric oxide formation in hepatocytes, and this increase was blocked by NG-monomethyl-L-arginine (a nitric oxide synthase inhibitor) and by interleukin-1 receptor antagonist. NG-monomethyl-l-arginine reversed inhibition of the ATP increase, decrease in the ketone body ratio, and increase in lactate production, which were induced by interleukin-lβ. Interleukin-1 receptor antagonist completely abolished all of the effects induced by interleukin-1 β. These results demonstrated that interleukin-1 β and interleukin-6 affect the insulin-induced energy metabolism in rat hepatocytes by different mechanisms. Specifically, interleukin-1 β inhibits ATP synthesis by causing the mitochondrial dysfunction, a process which may be mediated by nitric oxide

    Importance of Achromatic Contrast in Short-Range Fruit Foraging of Primates

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    Trichromatic primates have a ‘red-green’ chromatic channel in addition to luminance and ‘blue-yellow’ channels. It has been argued that the red-green channel evolved in primates as an adaptation for detecting reddish or yellowish objects, such as ripe fruits, against a background of foliage. However, foraging advantages to trichromatic primates remain unverified by behavioral observation of primates in their natural habitats. New World monkeys (platyrrhines) are an excellent model for this evaluation because of the highly polymorphic nature of their color vision due to allelic variation of the L-M opsin gene on the X chromosome. In this study we carried out field observations of a group of wild, frugivorous black-handed spider monkeys (Ateles geoffroyi frontatus, Gray 1842, Platyrrhini), consisting of both dichromats (n = 12) and trichromats (n = 9) in Santa Rosa National Park, Costa Rica. We determined the color vision types of individuals in this group by genotyping their L-M opsin and measured foraging efficiency of each individual for fruits located at a grasping distance. Contrary to the predicted advantage for trichromats, there was no significant difference between dichromats and trichromats in foraging efficiency and we found that the luminance contrast was the main determinant of the variation of foraging efficiency among red-green, blue-yellow and luminance contrasts. Our results suggest that luminance contrast can serve as an important cue in short-range foraging attempts despite other sensory cues that could be available. Additionally, the advantage of red-green color vision in primates may not be as salient as previously thought and needs to be evaluated in further field observations

    The whole blood transcriptional regulation landscape in 465 COVID-19 infected samples from Japan COVID-19 Task Force

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    「コロナ制圧タスクフォース」COVID-19患者由来の血液細胞における遺伝子発現の網羅的解析 --重症度に応じた遺伝子発現の変化には、ヒトゲノム配列の個人差が影響する--. 京都大学プレスリリース. 2022-08-23.Coronavirus disease 2019 (COVID-19) is a recently-emerged infectious disease that has caused millions of deaths, where comprehensive understanding of disease mechanisms is still unestablished. In particular, studies of gene expression dynamics and regulation landscape in COVID-19 infected individuals are limited. Here, we report on a thorough analysis of whole blood RNA-seq data from 465 genotyped samples from the Japan COVID-19 Task Force, including 359 severe and 106 non-severe COVID-19 cases. We discover 1169 putative causal expression quantitative trait loci (eQTLs) including 34 possible colocalizations with biobank fine-mapping results of hematopoietic traits in a Japanese population, 1549 putative causal splice QTLs (sQTLs; e.g. two independent sQTLs at TOR1AIP1), as well as biologically interpretable trans-eQTL examples (e.g., REST and STING1), all fine-mapped at single variant resolution. We perform differential gene expression analysis to elucidate 198 genes with increased expression in severe COVID-19 cases and enriched for innate immune-related functions. Finally, we evaluate the limited but non-zero effect of COVID-19 phenotype on eQTL discovery, and highlight the presence of COVID-19 severity-interaction eQTLs (ieQTLs; e.g., CLEC4C and MYBL2). Our study provides a comprehensive catalog of whole blood regulatory variants in Japanese, as well as a reference for transcriptional landscapes in response to COVID-19 infection

    DOCK2 is involved in the host genetics and biology of severe COVID-19

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    「コロナ制圧タスクフォース」COVID-19疾患感受性遺伝子DOCK2の重症化機序を解明 --アジア最大のバイオレポジトリーでCOVID-19の治療標的を発見--. 京都大学プレスリリース. 2022-08-10.Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge. Here we conducted a genome-wide association study (GWAS) involving 2, 393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3, 289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target

    What is the best reconstruction procedure after esophagectomy? A meta‐analysis comparing posterior mediastinal and retrosternal approaches

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    Abstract Thoracic esophagectomy is a particularly invasive and complicated surgical procedure, with a reconstruction of the gastrointestinal tract, such as the stomach, jejunum, or colon. The posterior mediastinal, retrosternal, and subcutaneous routes are the three possible esophageal reconstruction routes. Each route has advantages and disadvantages, and the optimal reconstruction route after esophagectomy remains controversial. Additionally, the best anastomotic techniques after esophagectomy in terms of location (Ivor Lewis or McKeown) and suturing (manual or mechanical) are debatable. Our meta‐analysis investigating postoperative complications after esophagectomy between the posterior mediastinal and retrosternal routes revealed that the posterior mediastinal route was associated with a significantly lower anastomotic leakage rate than the retrosternal route (odds ratio = 0.78, 95% confidence interval: 0.70–0.87, p < 0.0001). Conversely, pulmonary complications (odds ratio = 0.80, 95% confidence interval: 0.58–1.11, p = 0.19) and mortality between the posterior mediastinal and retrosternal routes (odds ratio = 0.79, 95% confidence interval: 0.56–1.12, p = 0.19) were not significantly different. However, the incidence of pneumonia may be lower when using the retrosternal route rather than the posterior mediastinal route for performing minimally invasive esophagectomy. The McKeown procedure is oncologically necessary for tumors located above the carina to dissect upper mediastinal and cervical lymph nodes; however, the Ivor Lewis procedure offers perioperative and oncological safety for tumors located under the carina. An individualized treatment strategy for selecting the optimal reconstruction procedure can be proposed in future studies based on oncological and patient risk factors considering mid‐ to long‐term quality of life
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