Biology subjects

Sugano, A.

Publications and source records attributed to Sugano, A..

5 recordsLinked to original sources

bioRxiv2026

Inosine Triphosphate Pyrophosphatase as a Candidate Associated with White Matter Abnormalities in Chronic Heart Failure

Background: White matter hyperintensities (WMHs) are common with normal brain aging and frequently observed also in chronic heart failure (CHF). However, the relationship between CHF and white matter abnormalities and the biological factors remain unclear. We investigated WMH and associated white matter microstructural changes, such as fractional anisotropy (FA), in CHF and explored candidate molecular factors. Methods: We conducted a longitudinal prospective observation including brain T2-FLAIR magnetic resonace imaging for 32 asymptomatic Stage B (mean age 63.3{+/-}10.5 years; 25% women) and 23 symptomatic Stage C CHF patients (mean age 67.3{+/-}7.1 years; 30% women). Plasma proteomics and Mendelian randomization (MR) were used to identify candidate proteins associated with both CHF and WMH. The association of candidate proteins was further investigated using complementary analyses in CHF rats, cultured cortical neurons, and community-based genetic data in UK Biobank. Results: Global WMH volume increased more in Stage C than Stage B patients, predominantly near the anterior periventricular white matter, despite comparable cardiac indices (4,717{+/-}5,335 mm3 vs. 2,116{+/-}3,134 mm3, P=0.027). SomaScan-based proteomic analysis of plasma samples from this patient cohort revealed that 44 proteins are significantly associated with both Stage C CHF and WMH progression (P<0.05). Of these 44 proteins, two-step Mendelian randomization analysis identified inosine triphosphate pyrophosphatase (ITPA) as the only candidate protein, further supported by an association between rare variants in ITPA and FA. In CHF rats, the anterior pericallosal cortex showed decreases in myelin basic protein density and FA and an increase in ITPA expression compared to sham rats. In cultured cortical neurons, recombinant ITPA exposure reduced total axonal length. Conclusions: Symptomatic CHF was associated with WMH and impaired white matter integrity. ITPA emerged as a candidate factor across human, animal, and cellular analyses. These findings provide a basis for investgating the biological pathways linking CHF and white matter injury.

neuroscience↗

bioRxiv2023

SARS-CoV-2 Omicron XBB.1.5 may be a cautionary variant by in silico study

In this research, we aimed to predict the relative risk of the recent new variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on the basis of our previous research. We first performed molecular docking simulation analyses of the spike proteins with human angiotensin-converting enzyme 2 (ACE2) to determine the binding affinities to human cells of three new variants of SARS-CoV-2: Omicron BQ.1, XBB, and XBB.1.5 We then investigated the three variants to discover the evolutionary distance of the spike protein gene (S gene) from the Wuhan, Omicron BA.1, and Omicron BA.4/5 variants, to understand the changes in the S gene. The results indicated that the XBB.1.5 variant had the highest binding affinity of the spike protein with ACE2 and the longest evolutionary distance of the S gene. This in silico evidence suggested that the XBB.1.5 variant may produce infections that spread more widely and faster than can infections of preexisting variants.

bioinformatics↗

bioRxiv2022

SARS-CoV-2 Omicron BA.2.75 variant may be much more infective than preexisting variants

ObjectivesIn our previous research, we developed a mathematical model via molecular simulation analysis to predict the infectivity of seven SARS-CoV-2 variants. In this report, we aimed to predict the relative risk of the recent new variants of SARS-CoV-2 as based on our previous research. MethodsWe subjected Omicron BA.4/5 and BA.2.75 variants of SARS-CoV-2 to the analysis to determine the absolute evolutionary distance of the spike protein gene (S gene) of the variants from the Wuhan variant so as to appreciate the changes in the spike protein. We performed the molecular docking simulation analyses of the spike proteins with human angiotensin-converting enzyme 2 (ACE2) to understand the docking affinities of these variants. We then compared the evolutionary distances and the docking affinities of these variants with those of the seven variants that we had analyzed in our previous research. ResultsThe evolutionary distances of the S gene in BA.4/5 and BA.2.75 from the Wuhan variant were longer than those of the other variants. BA.2.75 had the highest docking affinity of the spike protein with ACE2 (ratio per Wuhan variant). ConclusionThe important results from this analysis are the following: BA.2.75 has both the highest docking affinity and the longest evolutionary distance of the S gene. These results suggest that BA.2.75 infection can spread farther than can infections of preexisting variants.

bioinformatics↗

bioRxiv2022

Prediction of infectivity of SARS-CoV2: Mathematical Model with Docking Simulation analysis between Spike Protein and ACE2

Variants of a coronavirus (SARS-CoV-2) have been spreading in a global pandemic. Improved understanding of the infectivity of future new variants is important so that effective countermeasures against them can be quickly undertaken. In our research reported here, we aimed to predict the infectivity of SARS-CoV-2 by using a mathematical model with molecular simulation analysis, and we used phylogenetic analysis to determine the evolutionary distance of the spike protein gene (S gene) of SARS-CoV-2. We subjected the six variants and the wild type of spike protein and human angiotensin-converting enzyme 2 (ACE2) to molecular docking simulation analyses to understand the binding affinity of spike protein and ACE2. We then utilized regression analysis of the correlation coefficient of the mathematical model and the infectivity of SARS-CoV-2 to predict infectivity. The evolutionary distance of the S gene correlated with the infectivity of SARS-CoV-2 variants. The coefficient of the mathematical model obtained with results of molecular docking simulation also correlated with the infectivity of SARS-CoV-2 variants. These results suggest that the data from the docking simulation for the receptor binding domain of variant spike proteins and human ACE2 were valuable for prediction of SARS-CoV-2 infectivity. In addition, we developed a mathematical model for prediction of SARS-CoV-2 variant infectivity by using binding affinity obtained via molecular docking and the evolutionary distance of the S gene.

bioinformatics↗

bioRxiv2019

Serpentine mountain uplift in northern Japan triggered the divergence of a narrow endemic from a widespread (sub)arctic Asia-Alaska species complex of Lagotis (Plantaginaceae)

In the circumboreal region, plants often have extremely-wide species ranges. Lagotis minor-glauca species complex widespread from (sub)arctic Asia to Alaska, however, have two allied narrow endemics in northern Japan: a serpentine plant L. takedana endemic to the Yubari Mountains (Mt. Yubari) and a non-serpentine plant L. yesoensis endemic to the Taisetsu Mountains (Mt. Taisetsu). Elucidating their origins sheds light on drivers for secondary-speciation of widespread circumboreal plants. To infer phylogenetic distinctiveness of two narrow endemics with those related taxa, which contained 25 out of all the 29 species of the genus, chloroplast DNA (cpDNA), nuclear ribosomal (nrITS), two low copy nuclear gene (LCN) markers and genome-wide single-nucleotide polymorphism genotyping (MIG-seq) were used. In the result of cpDNA analyses, the Lagotis minor-glauca species complex formed a clade. Within the clade, L. yesoensis and a portion of L. glauca samples formed a subclade. However, monophyly of each of the four species was not supported. In the results of nrITS and two LCN analyses, L. takedana was monophyletic, while monophyly was not recovered for each L. yesoensis, L. glauca, and L. minor. Based on a Bayesian dating analysis using nrITS data, the age of the most recent common ancestor of L. takedana was Ma (95% confidence interval: 0.05-1.75 Ma). Possible scenario is that an ancestral linage being adapted to serpentine soils migrated into the alpine habitat of Mt. Yubari, that was formed with mountain uplift by the early Pleistocene, and subsequently reproductively isolated from non-serpentine populations and speciated. The contrasting result of L. yesoensis, that was phylogenetically indistinct, is possibly explained by incorrect taxonomy, or alternatively, shallow history and incomplete lineage sorting. In Mt. Taisetsu, massive volcanic eruptions had occurred the Early Pleistocene and even after the last glacial period, suggesting that alpine plants have not migrated into and established populations in Mt. Taisetsu until very recently. To fully resolve the phylogeny of the three species L. yesoensis, L. glauca, and L. minor, further analyses using high resolution molecular markers are needed. The present study illustrated that two narrow endemics in northern Japan diverged from the widespread species include phylogenetically distinctive and indistinctive species, owing to historical orogeny and ecological factors.

ecology↗