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Biomedical subjects

Satoshi Koyama

Publications and source records attributed to Satoshi Koyama.

At least 19 recordsLinked to original sources

Integrating multi-ancestry common and rare variant mapping accelerates therapeutic target discovery.

Integrating human genetics into therapeutic discovery accelerates drug development. However, ancestral biases in historical cohorts have left critical functional variation largely uncharted. Here, we leverage the diverse NIH All of Us Research Program to conduct comprehensive common- and rare-variant association analyses for 624 quantitative traits across 369,655 ancestrally diverse individuals. We identified 6,181 genome-wide significant locus-trait associations (526 novel) and 416 gene-trait associations (105 novel) via rare-variant burden testing. By integrating fine-mapping with computational variant-effect predictors, we systematically prioritized rare, likely causal variants driving these signals. Jointly modeling common and rare variation with protein-class annotations significantly improved the identification of known drug targets compared to common-variant analysis alone. Notably, we identified NRG4 as a high-confidence candidate therapeutic target for preserving kidney function. Our findings demonstrate that characterization of rare and common variation across diverse populations enhances causal gene discovery and identifies novel, actionable therapeutic targets.

Journal Article↗

The Biobank Rare Variant consortium powers the discovery of rare genetic associations through global collaboration.

Rare coding variants can have large effects on disease risk and provide direct routes from human genetics to disease mechanisms and therapeutic targets, but their discovery is constrained by sample size, particularly for low-prevalence diseases. Here we establish the Biobank Rare Variant Analysis (BRaVa) consortium, a global rare variant association resource that integrates sequencing and linked health-record data from ten biobanks and cohorts comprising over 1.2 million individuals across diverse ancestries. We performed gene-based meta-analyses of rare coding variation across 33 clinical endpoints and 11 quantitative traits. Aggregating evidence across biobanks and ancestries identified 514 gene-trait associations, including 31 not previously reported in prior studies or curated association resources following systematic literature review. Notably, 36.1% of gene-level associations were undetectable in any individual biobank, and 91 emerged only through cross-ancestry meta-analysis, demonstrating that federated integration enables discovery beyond the reach of single cohorts. Similar gains were observed at the variant level, where 25.0% of phenotype-locus associations were detectable only through meta-analysis. Effect size estimates were correlated across ancestries with concordant directions of effect, supporting the generalizability of rare variant associations. The identified signals implicate pathways involved in transcriptional and epigenetic regulation, metabolism, vascular and epithelial biology, and immune function, highlighting rare coding variation as an engine for biological discovery across medical record phenotypes. For example, damaging variation in ANKRD12 implicates inflammatory transcriptional dysregulation in asthma and chronic obstructive pulmonary disease, and ultra-rare predicted loss-of-function variants in NAA15 link protein acetylation processes to type 2 diabetes risk. BRaVa establishes a scalable framework and freely available community resource for rare variant meta-analysis across global biobanks. Public release of gene- and variant-level association summary statistics provides a reference map of rare coding variant associations to support disease gene discovery, biological interpretation, and therapeutic target prioritization as sequencing-linked health-record resources continue to expand.

Journal Article↗

Precision Diagnosis in APOL1 Kidney Disease With the p.N264K M1 Protective Variant.

IMPORTANCE: The APOL1 M1 (p.N264K) variant protects against G2-associated APOL1 focal segmental glomerulosclerosis (FSGS) and chronic kidney disease (CKD). However, the utility of knowing an individual's M1 status in guiding kidney disease diagnosis and other clinical scenarios remains underexplored. OBJECTIVE: To test 2 hypotheses: (1) in patients with APOL1 high-risk (HR) genotype kidney disease with at least 1 G2 allele, M1 can distinguish APOL1 CKD from non-APOL1 CKD; (2) in people with APOL1 low-risk (LR) genotypes, M1 is independently associated with protection against FSGS and CKD. DESIGN, SETTING, AND PARTICIPANTS: Retrospective case-control study using data from 2 tertiary care hospitals (Columbia University Irving Medical Center and Mass General Brigham Biobank) and population-based data (the UK Biobank [UKB], Electronic Medical Records and Genomics [eMERGE-III], and All of Us [AoU]). Participants were individuals with a diagnosis of FSGS or steroid-resistant nephrotic syndrome (SRNS), individuals with CKD, and controls. EXPOSURES: Exposures included the M1 variant (p.N264K) obtained from exome or genome sequencing data, sex, and genetic ancestry. MAIN OUTCOME AND MEASURE: The main outcome was the presence or absence of kidney disease, defined as FSGS or non-FSGS CKD, compared with non-kidney disease controls. Association between the M1 variant and disease status was assessed using odds ratios (ORs). RESULTS: A total of 107 696 individuals (54 994 [51.1%] female; 8779 [8.2%] with African ancestry, 78 475 [72.9%] with European ancestry, and 16 129 [15.0%] with multiethnic ancestry), including 3460 with FSGS or SRNS, 24 382 with non-FSGS CKD kidney disease, and 79 854 controls were enrolled in the discovery cohort. In the APOL1-HR group (1413 participants), M1 was significantly inversely associated with FSGS or SRNS cases compared with controls without kidney disease (OR, 0.20; 95% CI, 0.04-0.63; P = 3.69 × 10-3). Among individuals with CKD with APOL1-HR genotypes, M1 was 4 times more frequent in those whose CKD was not due to FSGS or SRNS. Importantly, electronic health record and biopsy review identified an alternative, non-APOL1 cause for CKD in nearly all APOL1-HR-M1 cases. There was no association between individuals with APOL1-LR genotypes with M1 and protection against CKD or FSGS. CONCLUSIONS AND RELEVANCE: In this case-control study of 107 696 individuals, presence of an APOL1-HR genotype M1 was significantly associated with protection against kidney disease, suggesting that it may have a role as a genetic modifier. Patients with CKD with an APOL1-HR genotype and M1 should be evaluated for an alternative and potentially treatable cause of their CKD.

Humans↗

DiscoDivas: Leveraging genetic ancestry continuum information to interpolate PRS for admixed populations.

The relatively low representation of admixed populations in both discovery and fine-tuning individual-level datasets limits polygenic risk score (PRS) development and equitable clinical translation for admixed populations. Under the assumption that the most informative PRS model for a genetically homogeneous sample varies linearly in an ancestry continuum space, we introduce a Genetic Distance-assisted PRS Combination Pipeline for Diverse Genetic Ancestries (DiscoDivas) to interpolate a harmonized PRS for diverse, especially admixed, genetic ancestries, leveraging multiple PRS models fine-tuned within existing samples, which are mostly of single ancestry, and genetic distance. DiscoDivas treats genetic ancestry as a continuous variable and does not require shifting between different models when calculating PRS for different ancestries. We generated PRS with DiscoDivas and the current conventional method, i.e. fine-tuning multiple GWAS PRS using the matched or similar genetic ancestry samples. DiscoDivas generated a harmonized PRS of the accuracy comparable to or higher than the conventional approach, with the greatest advantage exhibited in admixed individuals.

PRS harmonization↗

Nonadherence to guidelines for genetic testing in families with ovarian cancer shows racial bias.

PURPOSE: The National Comprehensive Cancer Network (NCCN) recommends germline genetic testing for individuals at risk for hereditary ovarian cancer. We sought to determine the proportion and characteristics of individuals meeting testing criteria in a multicenter biobank who were appropriately offered testing. METHODS: In this retrospective cohort study, we identified Mass General Brigham Biobank participants meeting genetic testing criteria per NCCN guidelines. Logistic regression was used to analyze sociodemographic factors associated with which participants were offered testing, completed testing, and had a family history that matched their self-report documented in the electronic medical record. RESULTS: Most eligible participants (909/1441, 63.1%) were not offered genetic testing. Participants who were Black or Hispanic had a lower likelihood of being offered testing. Compared with self-report, 988 (68.6%) participants had a family history of ovarian cancer documented in their electronic medical record. Older age, Hispanic ethnicity, and public insurance use were associated with decreased likelihoods of accurate family history documentation. Correct documentation was associated with an increased likelihood of being offered testing. CONCLUSION: The majority of participants in this study did not receive NCCN-compliant care. Germline genetic testing for hereditary ovarian cancer screening is underutilized and access to this testing is currently inequitable.

Adult↗

Genetic Predisposition to Low-Density Lipoprotein Cholesterol and Incident Type 2 Diabetes.

IMPORTANCE: Treatment to lower high levels of low-density lipoprotein cholesterol (LDL-C) reduces incident coronary artery disease (CAD) risk but modestly increases the risk for incident type 2 diabetes (T2D). The extent to which genetic factors across the cholesterol spectrum are associated with incident T2D is not well understood. OBJECTIVE: To investigate the association of genetic predisposition to increased LDL-C levels with incident T2D risk. DESIGN, SETTING, AND PARTICIPANTS: In this large prospective, population-based cohort study, UK Biobank participants who underwent whole-exome sequencing and genome-wide genotyping were included. Participants were separated into 7 groups with familial hypercholesterolemia (FH), predicted loss of function (pLOF) in APOB or PCSK9 variants, and LDL-C polygenic risk score (PRS) quintiles. Data were collected between 2006 and 2010, with a median follow-up of 13.7 (IQR, 12.9-14.5) years. Data were analyzed from March 1 to November 1, 2024. EXPOSURES: LDL-C level, LDL-C PRS, FH, or pLOF variant status. MAIN OUTCOMES AND MEASURES: Cox proportional hazards regression models adjusted for age, sex, genotyping array, lipid-lowering medication use, and the first 10 genetic principal components were fitted to assess the association between LDL-C genetic factors and incident T2D and CAD risks. RESULTS: Among the 361 082 participants, mean (SD) age was 56.8 (8.0) years, 194 751 (53.9%) were female, and mean (SD) baseline LDL-C level was 138.0 (33.6) mg/dL. During the follow-up period, 22 619 (6.3%) participants developed incident T2D and 17 966 (5.0%) developed incident CAD. The hazard ratio for incident T2D was lowest in the FH group (0.65; 95% CI, 0.54-0.77), while the highest risk was in the pLOF group (1.48; 95% CI, 1.18-1.86). The association between LDL-C PRS and incident T2D was 0.72 (95% CI, 0.66-0.79) for very high LDL-C PRS, 0.87 (95% CI, 0.84-0.90) for high LDL-C PRS, 1.13 (95% CI, 1.09-1.17) for low LDL-C PRS, and 1.26 (95% CI, 1.15-1.38) for very low LDL-C PRS. CAD risk increased directly with the LDL-C PRS. CONCLUSIONS AND RELEVANCE: In this cohort study, LDL-C and T2D risks were inversely associated across genetic mechanisms for LDL-C variation. Further elucidation of the mechanisms associating low LDL-C risk with increased risk of T2D is warranted.

Humans↗

Edaravone diminishes free radicals from circulating neutrophils in patients with ischemic brain attack.

OBJECTIVE: Treatment with a free radical scavenger could be a new option for ischemic brain attack, however, little is known about the alteration of oxidative stress markers induced by edaravone, a novel free radical scavenger, in human ischemic brain attack. METHODS: We investigated the effects of edaravone on the oxidative stress markers in patients with ischemic brain attack. Twenty-one patients with ischemic brain attack and 19 controls were enrolled in this study. Blood samples were obtained just before and soon after the first administration of edaravone (30 mg) or ozagrel (40 mg). Intracellular reactive oxygen species of neutrophils were measured using 6-carboxy-2', 7'-dichlorodihydrofluorescin diacetate and a fluorescence-activated cell sorter. Superoxide from neutrophils, induced by phorbol myristate acetate (PMA), was determined by luminol-amplified chemiluminescence assay. RESULTS: Treatment with 30 mg of edaravone significantly decreased the intracellular reactive oxygen species (ROS) of neutrophils (Wilcoxon test, p=0.0001) and PMA-induced superoxide produced by neutrophils (Wilcoxon test, p=0.001). Ozagrel did not alter the intracellular ROS or superoxide production of neutrophils. CONCLUSION: Reduction of intracellular ROS and suppression of superoxide production in neutrophils provide a potential explanation for the clinical efficacy of edaravone in patients with ischemic brain attack.

Aged↗

Identification and characterization of a novel human collectin CL-K1.

Collectins are a family of C-type lectins with two characteristic structures, collagen like domains and carbohydrate recognition domains. They recognize carbohydrate antigens on microorganisms and act as host-defense. Here we report the cloning and characterization of a novel collectin CL-K1. RT-PCR analyses showed CL-K1 mRNA is present in all organs. The deduced amino acid sequence and the data from immunostaining of CL-K1 cDNA expressing CHO cells revealed that CL-K1 is expressed as a secreted protein. CL-K1 is found in blood by immunoblotting and partial amino acid analyses. CL-K1 showed Ca(2+)-dependent sugar binding activity of fucose and weakly mannose but not N-acetyl-galactosamine, N-acetyl-glucosamine, or maltose, though mannose-binding lectin (MBL) containing similar amino acid motif. CL-K1 can recognize specially several bacterial saccharides due to specific sugar-binding character. Elucidation of the role of two ancestor collectins of CL-K1 and CL-L1 could lead to see the biological function of collectin family.

Amino Acid Sequence↗

[Homocysteine].

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Animals↗

Reticulon 3 is involved in membrane trafficking between the endoplasmic reticulum and Golgi.

Reticulons (RTNs) constitute a family of endoplasmic reticulum (ER)-associated proteins with a reticular distribution. Despite the implication of their neuronal isoforms in axonal regeneration, the function of their widely expressed isoforms is largely unknown. In this study, we examined the role of the ubiquitously expressed RTN3 in membrane trafficking. Ectopically expressed RTN3 exhibited heterogeneous patterns; filamentous, reticular, and granular distributions. The ER morphology changed accordingly. In cells where RTN3 displayed a filamentous/reticular distribution, protein transport between the ER and Golgi was blocked, and Golgi proteins were dispersed. In contrast, ERGIC-53, a marker for the ER-Golgi intermediate compartment, accumulated at the perinuclear region, and remained there even after cells were treated with agents that induce redistribution of Golgi proteins to the ER, indicating an inhibition of Golgi-to-ER transport of ERGIC-53. These results suggest that RTN3 plays a role in membrane trafficking in the early secretory pathway.

Carrier Proteins↗

Discovery of new diphenyloxazole derivatives containing a pyrrolidine ring: orally active prostacyclin mimetics. Part 2.

Synthetic and biological evaluation of novel diphenyloxazole derivatives containing a pyrrolidine ring, as a prostacyclin mimetic without the PG skeleton, are described. Asymmetric reduction of a ketone using a chiral Ru complex and reductive amination by NaBH(4) produces four isomers of the tetrahydronaphthalene ring and the pyrrolidine ring with high stereoselectivity. FR193262 (4), (R,R)-diphenyloxazolyl pyrrolidine derivative, displays high potency and agonist efficacy at the IP receptor and has good bioavailability in rats and dogs.

Animals↗

Metabolism investigation leading to novel drug design: orally active prostacyclin mimetics. Part 4.

A metabolism study of FR181157 (1) led to the discovery of new oxazole derivatives as active metabolites. The metabolite 6 with an epoxy ring exhibited high anti-aggregative potency with an IC(50) of 5.8 nM and potent binding affinity for the human recombinant IP receptor with a K(i) value of 6.1 nM and selectivity for human IP receptor over all other members of the human prostanoid receptor family.

Administration, Oral↗

Discovery of diphenylcarbamate derivatives as highly potent and selective IP receptor agonists: orally active prostacyclin mimetics. Part 3.

The new classes of diphenylcarbamate derivatives with a tetrahydronaphthalene skeleton as highly potent and selective IP agonists have been discovered. The optimized diphenylcarbamate type compound FK-788: (R)-4 exhibited potent antiaggregative potency with an IC50 of 18 nM and high binding affinity for the human recombinant IP receptor with K(i) values of 20 nM and selectivity for human IP over all other members of the human prostanoid receptor family. Compound (R)-4 was shown to exhibit good pharmacokinetic properties in rats and dogs, and also good bioavailability in healthy volunteers.

Administration, Oral↗

Cell lysis directed by sigmaE in early stationary phase and effect of induction of the rpoE gene on global gene expression in Escherichia coli.

It has been shown that Escherichia coli cells with increased expression of the rpoE gene encoding sigma(E) exhibit enhanced cell lysis in early stationary phase. Further analysis of the lysis phenomenon was performed using a transient expression system of the rpoE gene and by DNA microarray. The former analysis revealed a sigma(E)-directed cell lysis, specific for early stationary phase but not for the exponential phase. The microarray analysis with RNAs from exponential and early stationary phase cells revealed that a large number of genes were up- or down-regulated when the rpoE gene was induced, and that several genes were induced in a phase-specific manner. The upregulated genes include many previously identified sigma(E) regulon genes, suggesting that a large number of genes are under the control of sigma(E) in this organism. These genes are involved in various cellular activities, including the cell envelope, cellular processes, regulatory functions, transport and translation. Genes that are presumably related to phase-specific cell lysis in E. coli are discussed.

Escherichia coli↗

Transient swelling of peripheral nerves in a case of neurosarcoidosis.

We present a case of neurosarcoidosis showing bilateral carpal tunnel syndrome which disappeared without any medication. This patient was also suffering from motor and sensory disturbance caused by peripheral neuropathy of the four extremities. Magnetic resonance image showed transient swelling of the median nerve, and subperineurial edema was unexpectedly observed in some fascicles in sural nerve biopsy. We hypothesize that the carpal tunnel syndrome in this case was induced by the intercanal high pressure due to edema inside the tunnel, which might be related to the high level of serum IL-2.

Aged↗

Prevalence of multiple sclerosis in Asahikawa, a city in northern Japan.

Twenty-two years after the first survey, a follow-up study was performed on the prevalence of multiple sclerosis (MS) in Asahikawa, a city in northern Japan. The crude prevalence of MS rose from 2.5/100,000 (in 1975) to 10.2/100,000 (in 2002). The clinical diagnosis was established using the Poser diagnostic criteria, and the degree of physical disability was determined using the Expanded Disability Status Scale (EDSS). The distribution of patients according to the clinical form of MS was 65% with relapsing-remitting MS, 19% with secondary chronic progressive MS and 16% with the primary chronic progressive forms of MS. Symptoms at onset in the present study less often affected optic nerves (3%) than previously reported in Japan and was more like that seen in western MS series. Although prevalence of MS increase four-fold in Japan over the last two decades, it remains uncertain whether this apparent increase is real or reflects better ascertainment.

Adolescent↗

Effect of N-(4-Acetyl-1-piperazinyl)-p-fluorobenzamide monohydrate (FK960), an antidementia drug with a novel mechanism of action, on regional cerebral blood flow and glucose metabolism in aged rhesus macaques studied with positron emission tomography.

Effect of N-(4-acetyl-1-piperazinyl)-p-fluorobenzamide monohydrate (FK960), a putative antidementia drug with a novel mechanism of action, on regional cerebral blood flow (rCBF) and regional cerebral metabolic rate of glucose (rCMRglc) was examined in conscious aged rhesus macaques using positron emission tomography. Seven aged (21.6 +/- 2.7 years) male rhesus macaques were subjected. FK960 was intramuscularly administered at doses of 0, 0.01, 0.1, or 1 mg/kg for seven consecutive days, in randomized order and in a blinded manner. Each subject was scanned four times in all, with at least 3-week intervals, after treatment with saline or three doses of FK960. Significant increases in rCBF in the left temporal and left frontal cortex, and in rCMRglc in the right hippocampus with adjacent cortex, were observed in the treatment group with 1 mg/kg FK960, without affecting any other cardiovascular and respiratory variables. No statistically significant change in any region was observed at doses of 0.01 or 0.1 mg/kg. These results suggested that FK960 restored the rCBF and rCMRglc deficits in brain areas responsible for cognitive functioning in aged rhesus macaques.

Aging↗