Biology subjects

Sudo, K.

Publications and source records attributed to Sudo, K..

8 recordsLinked to original sources

bioRxiv2026

Ileitis abolishes tolerogenic functions of the enterohepatic bile acid pool

Bile acids (BAs) regulate lipid uptake, epithelial integrity, and immune responses in the gut. Hepatocytes synthesize primary BAs, which microbiota metabolize into secondary metabolites. Together, these species form a composite pool that circulates enterohepatically between the liver and intestines. Here, we show that immunoregulatory outputs of the enterohepatic BA pools involve competition between multiple BA species for individual nuclear receptors and are dependent on intestinal health. In healthy mice, the primary BA, tauro {beta} muricholic acid (t{beta}MCA) antagonized ROR{gamma}t-mediated Th17 function in the presence of two secondary BAs (tDCA, tLCA) which activated ROR{gamma}t. Conversely, ileitis in Crohns disease patients and Tnf{delta}ARE mice depleted primary BAs by reducing the number and function of BA transporting enterocytes. In mice, ileitis driven t{beta}MCA depletion enhanced tDCA and tLCA mediated ROR{gamma}t activation and supported Th17 cell function. Replenishing t{beta}MCA in Tnf{delta}ARE mice reestablished BA dependent Th17 cell regulation. Thus, intra pool competition underpins BA immunoregulatory functions and reveals new opportunities for precision Crohns disease therapy.

immunology↗

bioRxiv2026

A macrocyclic peptide-based fusion inhibitor targeting SARS-CoV-2 Spike S2 subunit

Continuous emergence of SARS-CoV-2 variants carrying mutations in Spike presents a significant challenge for durable antiviral agents. Here we screen for random 13-amino acid non-mimetic macrocyclic peptides that bind to Spike and identify PA-001 that inhibits SARS-CoV-2 infection with high potency at 0.23-2.9 nM as 50% inhibitory concentration (IC50). PA-001 bound to Spike S2 subunit and inhibited the membrane fusion during virus entry. Through drug-resistant selection, we revealed that PA-001 targeted the fusion peptide proximal region (FPPR) in S2, which has not been recognized as a drug target to date. Consistent with its highly conserved amino acid sequences beyond strains, PA-001 exhibited broad antiviral activity against all tested SARS-CoV-2 variants, in contrast to clinically-approved S1-targeting antibodies that lost activity to Omicron variants. PA-001 suppressed SARS-CoV-2 propagation and disease progression in mouse- and hamster-infection models, both by administration prophylactically and therapeutically. Combination therapy with remdesivir further enhanced antiviral profiles. In clinical phase-I trial, PA-001 was well-tolerated and showed high systemic exposure, with 4,300-10,300-fold concentration of IC50 as maximum plasma concentration by single administration to healthy volunteers. These evidence propose FPPR as an unexpected antiviral drug target accessible by macrocyclic peptides and identify PA-001 as a potent anti-SARS-CoV-2 fusion inhibitor.

microbiology↗

bioRxiv2024

Quantifying forms and functions of intestinal bile acid pools in mice

Bile acids (BAs) are gastrointestinal metabolites that serve dual functions in lipid absorption and cell signaling. BAs circulate actively between the liver and distal small intestine (i.e., ileum), yet the dynamics through which complex BA pools are absorbed in the ileum and interact with intestinal cells in vivo remain ill-defined. Through multi-site sampling of nearly 100 BA species in individual wild type mice, as well as mice lacking the ileal BA transporter, Asbt/Slc10a2, we calculate the ileal BA pool in fasting C57BL/6J mice to be [~]0.3 moles/g. Asbt-mediated transport accounts for [~]80% of this pool and amplifies size, whereas passive absorption explains the remaining [~]20%, and generates diversity. Accordingly, ileal BA pools in mice lacking Asbt are [~]5-fold smaller than in wild type controls, enriched in secondary BA species normally found in the colon, and elicit unique transcriptional responses in cultured ileal explants. This work quantitatively defines ileal BA pools in mice and reveals how BA dysmetabolism can impinge on intestinal physiology.

physiology↗

bioRxiv2023

mRNA vaccine induces protective immunity against the type III secretory virulence of Pseudomonas aeruginosa

Few studies have addressed mRNA vaccination against bacteria despite the desperate need to control antimicrobial resistance. Herein, we developed mRNA vaccines targeting the type III secretion system of Pseudomonas aeruginosa, which plays a critical role in the pathogenesis. Vaccination with a nucleoside-modified mRNA encapsulated in lipid nanoparticles improved mouse survival, reduced the bacterial load in the lung, and alleviated pathological changes in the lungs after bacterial challenge.

immunology↗

bioRxiv2021

Induction of antioxidant and detoxifying enzymes by oriental bezoar

ObjectivesOriental bezoar, a gallstone formed in the gall sac of Bos taurus Linne var. domesticus Gmelin (Bovidae), has been used as a crude drug in oriental medicine for stroke, convulsion, epilepsy, swelling and pain in the throat, and high fever. Despite reports on the antioxidative effect of oriental bezoar-containing drugs, in vitro-cultured calculus bovis (a substitute for oriental bezoar), and its components (namely, bilirubin and biliverdin), the intracellular mechanism of the antioxidative action of oriental bezoar remains unclear. Therefore, we studied the effect of oriental bezoar on the nuclear factor erythroid 2-related factor 2 (Nrf2)-antioxidant response element (ARE) pathway, which transcriptionally regulates genes encoding antioxidant and detoxifying enzymes, such as heme oxygenase-1 (HO-1), glutathione-S-transferase alpha 1 (GSTA1), and quinone oxidoreductase 1 (NQO1), to elucidate its antioxidative effect. MethodsARE promoter activity and mRNA expression (HO-1, GSTA1, and NQO1) in HepG2 cells supplemented with test drugs were examined in vitro by luciferase reporter assay and real-time PCR, respectively. ResultsOriental bezoar induced ARE promoter activity and increased the mRNA expression level of HO-1, GSTA1, and NQO1. Its components, namely, bilirubin and biliverdin, also increased the ARE promoter activity. ConclusionThese results suggest that oriental bezoar can induce antioxidative and detoxification effects via the Nrf2-ARE pathway.

pharmacology and toxicology↗

bioRxiv2020

Protective effects of saffron and its constituent crocetin to motor symptoms, short life span and rough-eyed phenotypes in the fly models of Parkinson's disease in vivo

Parkinsons disease (PD) is a common neurodegenerative disorder with motor symptoms linked to the loss of dopaminergic neurons in the brain. -Synuclein is an aggregation-prone neural protein that plays a role in the pathogenesis of PD. In our previous paper, we found that saffron; the stigma of Crocus sativus Linne (Iridaceae), and its constituents (crocin and crocetin) suppressed aggregation of -synuclein and promoted the dissociation of -synuclein fibrils in vitro. In this study, we investigated the effect of dietary saffron and its constituent, crocetin, in vivo on a fly PD model overexpressing several mutant -synuclein in a tissue-specific manner. Saffron and crocetin significantly suppressed the decrease of climbing ability in the Drosophila overexpressing A30P (A30P fly PD model) or G51D (G51D fly PD model) mutated -synuclein in neurons. Saffron and crocetin extended the life span in the G51D fly PD model. Saffron suppressed the rough-eyed phenotype and the dispersion of the size histogram of the ocular long axis in A30P fly PD model in eye. Saffron had a cytoprotective effect on a human neuronal cell line with -synuclein fibrils. These data showed that saffron and its constituent crocetin have protective effects on the progression of PD disease in animals in vivo and suggest that saffron and crocetin can be used to treat PD.

pharmacology and toxicology↗

bioRxiv2019

SMAD3 Determines Conventional versus Plasmacytoid Dendritic Cell Fates

Transforming growth factor (TGF)-{beta} plays crucial roles in differentiation of dendritic cells (DC). However, molecular mechanisms how TGF-{beta} regulates DC differentiation remain largely unknown. Here, we show that selective repression of one of the TGF-{beta} receptor-regulated SMADs (R-SMADs), SMAD3 directs conventional DC (cDC) differentiation, whereas maintenance of SMAD3 is indispensable for plasmacytoid DC (pDC) differentiation. Expression of SMAD3 was specifically downregulated in CD115+ common DC progenitor (CDP), pre-cDCs and cDCs. SMAD3 deficient mice showed a significant reduction in pre-pDCs and pDCs with increased CDP, pre-cDCs and cDCs. SMAD3 upregulated the pDC-related genes: SPI-B, E2-2 and IKAROS, while it repressed FLT3 and the cDC-related genes: IRF4 and ID2. STAT3 and a SMAD transcriptional co-repressor, c-SKI repressed SMAD3 for cDC differentiation, whereas canonical SMAD-mediated TGF-{beta} signalling maintained SMAD3 for pDC differentiation. Thus, SMAD3 is the pivotal determinant to bifurcate cDC and pDC differentiation in the steady-state condition.

immunology↗

bioRxiv2018

Comparative evaluation of the GeeniusTM HIV 1/2 Confirmatory Assay and the HIV-1 and HIV-2 Western blots in the Japanese population

Accurate diagnosis of earlier HIV infection is essential for treatment and prevention. Currently, confirmation tests of HIV infection in Japan are performed using Western blot (WB), but WB has several limitations including low sensitivity and cross-reactivity between HIV-1 and HIV-2 antibodies. To address these problems, a new HIV testing algorithm and a more reliable confirmation and HIV-1/2 differentiation assay are required. The Bio-Rad Geenius HIV-1/2 Confirmatory Assay (Geenius) has recently been approved and recommended for use in the revised guidelines for diagnosis of HIV infection by the Center for Disease Control and Prevention (USA). We made comprehensive comparison of the performance of Geenius and the Bio-Rad NEW LAV BLOT 1 and 2 (NLB 1 and 2) which are WB kits for HIV-1 and HIV-2, respectively, to examine if Geenius is a suitable alternative to these WB assays which are now being used in HIV testing in Japan. A total of 166 HIV-1 positive samples (146 from patients with established HIV-1 infection and 20 from patients with acute infection), five HIV-1 seroconversion panels containing 21 samples and 30 HIV-2 positive samples were used. In addition, a total of 140 HIV negative samples containing 10 false-positives on screening tests were examined. The sensitivity of Geenius and NLB 1 for HIV-1 positive samples was 99.3% and 98.6%, respectively. Geenius provided more positive results in the samples from acute infections and detected positivity 0 to 32 days earlier in seroconversion panels than NLB 1. NLB 2 gave positive results in 12.3% of HIV-1 positive samples. The sensitivity of both Geenius and NLB 2 for HIV-2 positive samples was 100%. The specificity of Geenius, NLB 1 and NLB 2 was 98.5%, 81.5% and 90.0%, respectively. Geenius is an attractive alternative to WB for confirmation and differentiation of HIV-1 and HIV-2 infections. The adaptation of Geenius to the HIV testing algorithm may be advantageous for rapid diagnosis and the reduction of testing costs.

molecular biology↗