Induction of cyclooxygenase-2 in human synovial cells by β2-microglobulin

Induction of cyclooxygenase-2 in human synovial cells by β2-microglobulin.BackgroundProstaglandins (PGs) are important mediators of inflammation in arthritis. We evaluated the role of the cyclooxygenase-2 (COX-2) enzyme, which regulates PG biosynthesis, in osteoarthropathy associated with hemodialysis-associated amyloidosis (HAA) by characterizing COX-2 expression in β2-microglobulin–treated human synovial cells.MethodsWe examined the effects of β2-microglobulin (β2m), a major constituent protein of amyloid fibrils in HAA, on the COX-2 protein and mRNA expression in human synovial cells using Western blot and reverse transcriptase-polymerase chain reaction.Resultsβ2m selectively increased the biosynthesis of COX-2 protein and induction of COX-2 mRNA in a dose-dependent manner. Immunoabsorption of β2m–containing media by anti-β2m–specific antibody abrogated β2m–mediated COX-2 expression on synovial cells. On the other hand, dexamethasone markedly suppressed the induction of COX-2 protein and mRNA in β2m–stimulated synovial cells.ConclusionsOur results suggest that induction of COX-2 expression by β2m may be an important component of the inflammatory process in hemodialysis-associated osteoarthropathy

Revisiting museum collections in the genomic era: potential of MIG-seq for retrieving phylogenetic information from aged minute dry specimens of ants (Hymenoptera: Formicidae) and other small organisms

Multiplexed inter-simple sequence repeat genotyping by sequencing – MIG-seq – is an effective PCR-based method for genome-wide SNP detection using the Next-Generation Sequencing platform, and it provides a potential solution to a central problem in museomics – the difficulties of obtaining useful sequence data from aged specimens with often degraded and / or low yields of DNA. We demonstrate and validate the cost effectiveness and utility of the MIG-seq workflow in obtaining useful and robust sequence data from aged museum specimens. We applied the MIG-seq approach to 55 aged (10 - 23 years old) millimeter-sized dry-mounted specimens of the hyper-diverse ant genus Pheidole. A total of 50,782,736 reads were generated from the 55 samples (259,902 - 3,693,375 reads per sample). The reads corresponded to 36,862 SNPs from 4,849 polymorphic loci; the SNP dataset was then used to construct a Bayesian phylogenetic tree. The topology of the phylogenetic tree was highly compatible with existing knowledge of phylogenetic relationships among species of Pheidole. Therefore, we recommend the MIG-seq method as a cost-effective and highly applicable pipeline for conducting phylogenetic and population genetic studies on aged museum specimens, potentially enhancing the relevance of specimen repositories in general towards modern biodiversity science and conservation biology

Comparative study of the effect of neuromuscular electrical stimulation and oral administration of branched-chain amino acid on preventing sarcopenia in patients after living-donor liver transplantation: study protocol for an open-label randomized controlled trial

Background: Liver cirrhosis is the irreversible fibrosis of the liver and causes refractory ascites and hepatic encephalopathy, which might not respond to treatment. Living donor liver transplantation (LDLT) is an effective treatment for patients with cirrhosis. However, post-LDLT patients are prone to muscle atrophy and sarcopenia. Therefore, physiotherapy of post-LDLT patients is essential for preventing the progression of sarcopenia. Recently, rehabilitation using neuromuscular electrical stimulation (NMES) has been reported to be useful for preventing the progression of sarcopenia. Similarly, nutrition therapy is essential for post-LDLT patients because these patients frequently experience malnutrition. However, the effects of combined NMES and nutrition therapy on post-LDLT patients remain unknown. Methods/design: This open-label, randomized, parallel-group study will compare the effects of combined therapy with NMES and branched-chain amino acids (BCAA) with those of NMES alone in patients with decompensated cirrhosis after LDLT. After LDLT, 50 patients with decompensated cirrhosis will be randomly assigned to receive NMES with BCAA or NMES without BCAA. The duration of the intervention will be 3 months. To analyze the change in skeletal muscle mass, InBody 770 body composition and body water analysis and ultrasonography will be performed before LDLT and 4 weeks and 12 weeks post-LDLT. The primary endpoint is changes in the skeletal muscle mass from baseline to 3 months. Important secondary endpoints are the changes in the skeletal muscle mass from baseline to 1 month and changes in the quadriceps strength from baseline to 1 month. Discussion: The results of this study are expected to provide evidence regarding the effect of NMES combined with BCAA therapy on the skeletal muscle of post-LDLT patients. Trial registration: Japan Registry of Clinical Research jRCTs071190051. Registered on February 26, 2020

Larval pufferfish protected by maternal tetrodotoxin

Marine pufferfish contain tetrodotoxin (TTX), an extremely potent neurotoxin. All species of the genus Takifugu accumulate TTX in the liver and ovaries, although the tissue(s) in which it is localized can differ among species. TTX is the major defense strategy the pufferfish appears to use against predators. TTX is also used as a male-attracting pheromone during spawning. Here we demonstrate an additional (and unexpected) use of maternal TTX in the early larval stages of the Takifugu pufferfish. Predation experiments demonstrated that juveniles of all the species of fish used as predators ingested pufferfish larvae, but spat them out promptly. Liquid Chromatography-Tandem Mass Spectrometry (LC-MSMS) analysis revealed that the pufferfish larvae contain a small quantity of TTX, which is not enough to be lethal to the predators. Immunohistochemical analysis with anti-TTX monoclonal antibody revealed that the TTX is primarily localized in the body surface of the larvae as a layer of protection. Our study showed the female parent of the Takifugu pufferfish vertically transfers TTX to the larvae through its accumulation in the ovaries, and subsequent localization on the body surface of the larvae

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

「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

Mechanisms Underlying Resistance to FLT3 Inhibitors in Acute Myeloid Leukemia

FLT3-ITD and FLT3-TKD mutations were observed in approximately 20 and 10% of acute myeloid leukemia (AML) cases, respectively. FLT3 inhibitors such as midostaurin, gilteritinib and quizartinib show excellent response rates in patients with FLT3-mutated AML, but its duration of response may not be sufficient yet. The majority of cases gain secondary resistance either by on-target and off-target abnormalities. On-target mutations (i.e., FLT3-TKD) such as D835Y keep the TK domain in its active form, abrogating pharmacodynamics of type II FLT3 inhibitors (e.g., midostaurin and quizartinib). Second generation type I inhibitors such as gilteritinib are consistently active against FLT3-TKD as well as FLT3-ITD. However, a “gatekeeper” mutation F691L shows universal resistance to all currently available FLT3 inhibitors. Off-target abnormalities are consisted with a variety of somatic mutations such as NRAS, AXL and PIM1 that bypass or reinforce FLT3 signaling. Off-target mutations can occur just in the primary FLT3-mutated clone or be gained by the evolution of other clones. A small number of cases show primary resistance by an FL-dependent, FGF2-dependent, and stromal CYP3A4-mediated manner. To overcome these mechanisms, the development of novel agents such as covalently-coupling FLT3 inhibitor FF-10101 and the investigation of combination therapy with different class agents are now ongoing. Along with novel agents, gene sequencing may improve clinical approaches by detecting additional targetable mutations and determining individual patterns of clonal evolution