Publications by authors named "Yukiko Miyamoto"

Sialic acids (Sias) are a diverse family of nine-carbon backbone monosaccharides occupying terminal positions on cell surface and secreted glycans and are abundant at mucosal surfaces. Sias can be modified with -acetyl esters on the side chain (C7 to C9) hydroxyls. Structural analysis and functional studies of these modifications are challenging due to chemical lability and variable resistance to sialidases.

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Alcohol-associated liver disease poses a global health burden with high mortality. Imbalances in the gut microbiota are important for disease progression. Using metagenomic sequencing of fecal samples from a multicenter, international cohort of patients with alcohol-associated hepatitis, we found that the presence of virulence factor KpsM, encoded in the genome of Escherichia coli (E.

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Alcohol-associated liver disease represents a significant global health challenge, with gut microbial dysbiosis and bacterial translocation playing a critical role in its pathogenesis. Patients with alcohol-associated hepatitis had increased fecal abundance of mammalian viruses, including retroviruses. This study investigated the role of endogenous retroviruses (ERVs) in the development of alcohol-associated liver disease.

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Article Synopsis
  • Trichomonas vaginalis (Tv) is a protozoan parasite that causes trichomoniasis, the most prevalent non-viral sexually transmitted infection globally, but current treatment options are limited and facing resistance issues.
  • Researchers are targeting the proteasome, a key enzyme complex in eukaryotes, to develop new treatments by isolating the enzyme and identifying specific inhibitors for its three catalytic subunits (β1, β2, β5).
  • By creating specialized substrates for each subunit and screening a library of inhibitors, the study found that targeting the Tv β5 subunit is particularly effective in killing the parasite, which may lead to improved drug development strategies against trichomoniasis.
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The proteasome is a proteolytic enzyme complex essential for protein homeostasis in mammalian cells and protozoan parasites like Trichomonas vaginalis (Tv), the cause of the most common, non-viral sexually transmitted disease. Tv and other protozoan 20S proteasomes have been validated as druggable targets for antimicrobials. However, low yields and purity of the native proteasome have hindered studies of the Tv 20S proteasome (Tv20S).

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Article Synopsis
  • Trichomonas vaginalis causes trichomoniasis, a widespread STD that affects over a hundred million people, and resistance to common treatments like metronidazole is increasing.
  • The study explored using Tritrichomonas foetus, a related parasite, as a better animal model for testing new treatments since it caused reliable infections in mice, unlike T. vaginalis.
  • Findings showed that while some drugs had similar effectiveness on both parasites, proteasome inhibitors were less effective on T. foetus, suggesting the need for targeted drug development and further understanding of genetic differences between the two organisms.
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  • The poly(A) signal is critical for determining the 3' end of mature mRNA transcripts, with the common signal in humans being the AAUAAA hexamer, while a unique hexamer (AGURAA) was discovered in a deeply branching eukaryote.
  • Research showed that the AAUAAA signal is likely ancestral, appearing in at least four different eukaryotic clades, indicating its evolutionary significance.
  • Findings also highlighted that auxiliary elements influencing cleavage sites are variable and can differ within species, suggesting that the processes governing gene expression are dynamic and warrant further study for potential therapeutic applications against eukaryotic pathogens.
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is an important protozoan cause of diarrheal disease worldwide, delayed development and cognitive impairment in children in low- and middle-income countries, and protracted post-infectious syndromes in developed regions. resides in the lumen and at the epithelial surface of the proximal small intestine but is not mucosa invasive. The protozoan parasite is genetically diverse with significant genome differences across strains and assemblages.

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The intestinal parasites and are major causes of morbidity and mortality associated with diarrheal diseases. Metronidazole is the most common drug used to treat giardiasis and amebiasis. Despite its efficacy, treatment failures in giardiasis occur in up to 5%-40% of cases.

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Mitochondrial DNA m.3243A > G mutation causes mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) and its associated multi-organ disorders, including diabetes. To clarify associations between m.

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Article Synopsis
  • Proteasomes play a critical role in maintaining protein balance in mammalian cells and protozoan parasites, making the 20S proteasome a promising drug target.
  • Researchers successfully created a recombinant version of the 20S proteasome, enabling detailed study of its biochemical properties and response to inhibitors like marizomib (MZB) and carmaphycin-17 (CP-17).
  • High-resolution cryo-EM structures revealed how these inhibitors bind to the proteasome, shedding light on their specificity, and supporting the development of targeted treatments for trichomoniasis.
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The protozoan parasite, (Tv) causes trichomoniasis, the most common, non-viral, sexually transmitted infection in the world. Only two closely related drugs are approved for its treatment. The accelerating emergence of resistance to these drugs and lack of alternative treatment options poses an increasing threat to public health.

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Live bacterial therapeutics (LBTs) could reverse diseases by engrafting in the gut and providing persistent beneficial functions in the host. However, attempts to functionally manipulate the gut microbiome of conventionally raised (CR) hosts have been unsuccessful because engineered microbial organisms (i.e.

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Giardia lamblia is a leading protozoal cause of diarrheal disease worldwide. Infection is associated with abdominal pain, malabsorption and weight loss, and protracted post-infectious syndromes. A human vaccine is not available against G.

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The protozoan pathogen Giardia lamblia is an important worldwide cause of diarrheal disease and malabsorption. Infection is managed with antimicrobials, although drug resistance and treatment failures are a clinical challenge. Prior infection provides significant protection, yet a human vaccine has not been realized.

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Metronidazole (MTZ) is a clinically important antimicrobial agent that is active against both bacterial and protozoan organisms. MTZ has been used extensively for more than 60 years and until now resistance has been rare. However, a recent and dramatic increase in the number of MTZ resistant bacteria and protozoa is of great concern since there are few alternative drugs with a similarly broad activity spectrum.

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Aims/introduction: Diastolic cardiac dysfunction in type 2 diabetes (DD2D) is a critical risk of heart failure with preserved ejection fraction. However, there is no established biomarker to detect DD2D. We aimed to investigate the predictive impact of fragmented QRS (fQRS) on electrocardiography on the existence of DD2D.

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Background: Obesity, non-alcoholic fatty liver disease (NAFLD) and its more advanced form non-alcoholic steatohepatitis (NASH) are important causes of morbidity and mortality worldwide. Bile acid dysregulation is a pivotal part in their pathogenesis. The aim of this study was to evaluate the bile acid sequestrant colesevelam in a microbiome-humanized mouse model of diet-induced obesity and steatohepatitis.

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Atherosclerosis is an inflammatory disease of the artery walls and involves immune cells such as macrophages. Olfactory receptors (OLFRs) are G protein–coupled chemoreceptors that have a central role in detecting odorants and the sense of smell. We found that mouse vascular macrophages express the olfactory receptor and all associated trafficking and signaling molecules.

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Background & Aims: Studies investigating the gut-liver axis have largely focused on bacteria, whereas little is known about commensal fungi. We characterized fecal fungi in patients with non-alcoholic fatty liver disease (NAFLD) and investigated their role in a fecal microbiome-humanized mouse model of Western diet-induced steatohepatitis.

Methods: We performed fungal internal transcribed spacer 2 sequencing using fecal samples from 78 patients with NAFLD, 16 controls and 73 patients with alcohol use disorder.

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Trichomoniasis is a common and widespread sexually-transmitted infection, caused by the protozoan parasite Trichomonas vaginalis. T. vaginalis lacks the biosynthetic pathways for purines and pyrimidines, making nucleoside metabolism a drug target.

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The microbiota plays a critical role in regulating organismal health and response to environmental stresses. Intermittent hypoxia and hypercapnia, a condition that represents the main hallmark of obstructive sleep apnea in humans, is known to induce significant alterations in the gut microbiome and metabolism, and promotes the progression of atherosclerosis in mouse models. To further understand the role of the microbiome in the cardiovascular response to intermittent hypoxia and hypercapnia, we developed a new rodent cage system that allows exposure of mice to controlled levels of O and CO under gnotobiotic conditions.

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causes the most common, nonviral sexually transmitted infection. Only metronidazole (Mz) and tinidazole are approved for treating trichomoniasis, yet resistance is a clinical problem. The gold(I) complex, auranofin, is active against and other protozoa but has significant human toxicity.

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Synopsis of recent research by authors named "Yukiko Miyamoto"

  • Yukiko Miyamoto's recent research primarily focuses on the development of novel drug strategies against protozoan infections, notably Trichomonas vaginalis and Giardia, addressing the urgent need due to rising resistance to conventional treatments.
  • A significant finding is the structural elucidation of the 20S proteasome from Trichomonas vaginalis, providing insights into potential inhibitor interactions which can guide future antimicrobial drug development.
  • Additionally, Miyamoto's work explores the evolutionary dynamics of polyadenylation signals in eukaryotes, contributing to a deeper understanding of RNA processing mechanisms in diverse species.