Biology subjects

Kuwahara, A.

Publications and source records attributed to Kuwahara, A..

4 recordsLinked to original sources

bioRxiv2026

GSDMD transcript levels are higher in endothelial than cardiomyocyte compartments across three human heart cohorts

Cardiac GSDMD research has largely centred on cardiomyocytes. We quantified donor-level endothelial-minus-cardiomyocyte differences in two single-nucleus cohorts and one GeoMx spatial cohort, retaining assay-specific scales. GSDMD was higher in endothelial compartments in 42/42, 38/38 and 27/32 donors and ranked, post hoc, at the 94.9th, 95.1st and 97.4th percentiles of the corresponding within-cohort signed-contrast distributions. Although positive direction and complete donor concordance were not unique transcriptome-wide, this hypothesis-led target retained high rank across markedly different reference backgrounds and assay modalities. A fixed eight-transcript panel included both endothelial- and cardiomyocyte-shifted members, arguing against a uniform panel-wide directional shift or simple detection failure. GeoMx provided the most discriminating transcriptome background but remained composition-sensitive. GSDMD transcripts are therefore recurrently higher in endothelial than cardiomyocyte compartments across human-heart cohorts, showing that a cardiomyocyte-only interpretation of human-heart GSDMD transcript signals is incomplete.

cell biology↗

bioRxiv2026

Spatial transcriptomics identifies a translayer architecture of pyroptosis-related transcription in systemic sclerosis skin

Anatomical-layer enrichment does not establish cellular attribution, so correspondence with major-cell-class expression must be tested gene by gene. Systemic sclerosis (SSc) skin is informative because inflammasome- and pyroptosis-related molecules have been reported across epidermal, fibroblast-associated and vascular contexts. Spatial transcriptomics of SSc and control skin, with same-donor single-nucleus profiles from 10 SSc donors, revealed gene-specific correspondence. Across 13 discovery sections, NLRP1, PYCARD and CASP4 were epidermally biased, whereas GSDMD was dermally biased. An independent 10-section SSc cohort supported epidermal NLRP1 (q = 0.0078) and PYCARD (q = 0.043), with directional, non-significant support for CASP4 and GSDMD. Despite epidermal NLRP1 bias, endothelial class-pseudobulk exceeded keratinocyte class-pseudobulk in all 10 donors. Restricted three-class reconstruction reproduced the NLRP1 direction in 1 and 0 of 10 donors under the two fixed dermal weightings and in 0-8 of 10 across a post hoc sweep of the dermal endothelial share; PYCARD and GSDMD were concordant in most donors at every weighting, and CASP4 in no more than 4 of 10. Thus, tissue layer and major cell class are gene-specifically non-equivalent axes of spatial interpretation.

immunology↗

bioRxiv2023

Intronic TNR-retained ISOPROPYLMALATE ISOMERASE LARGE SUBUNIT1 transcripts impair leaf development in Arabidopsis

Intronic trinucleotide repeat (TNR) is widely distributed in plant genomes. In Arabidopsis accession Bur-0, abnormally expanded TTC repeat in intron-3 of the ISOPROPYLMALATE ISOMERASE LARGE SUBUNIT1 (IIL1) gene causes growth defects called the irregularly impaired leaves (iil) phenotype, triggered by DNA methylation-mediated IIL1 gene silencing at elevated temperature. However, little is known about how the reduced expression of IIL1 causes the iil phenotype. We demonstrated that the iil phenotype was resulted from the relative increase of intron-3-retained IIL1 transcripts through the experiments where the iil phenotype was reproduced by introducing the IIL1 gene harboring 100 copies of TTC repeat into Col-0. The iil phenotype appeared when the total amount of the IIL1 transcripts was decreased by co-suppression and the percentage of intron-3-retained IIL1 transcripts was increased. The IIL1 gene encodes an isopropylmalate isomerase large subunit, forming heterodimers with small subunits (AtLeuD1, AtLeuD2, or AtLeuD3). In the myb28 myb29 mutant lacking AtLeuD1 and AtLeuD2, the iil phenotype was almost completely suppressed regardless of higher percentage of intron-3-retained IIL1 transcripts. The results indicated that the iil phenotype was associated with interaction with AtLeuDs, suggesting that intronic TNR-containing transcripts were translated into abnormal proteins and perturbed the metabolic pathway supporting the leaf development.

plant biology↗

bioRxiv2022

Self-organization, quality control, and preclinical studies of human iPSC-derived retinal sheets for tissue-transplantation therapy

Three-dimensional retinal organoids (3D-retinas) are a promising graft source for transplantation therapy. We previously developed self-organizing culture for 3D-retina generation from human pluripotent stem cells (hPSCs). Here we present a quality control method and preclinical studies for tissue-sheet transplantation. Self-organizing hPSCs differentiated into both retinal and off-target tissues. Gene expression analyses identified the major off-target tissues as eye-related, cortex-like, and spinal cord-like tissues. For quality control, we developed a qPCR-based test in which each hPSC-derived neuroepithelium was dissected into two tissue-sheets: inner-central sheet for transplantation and outer-peripheral sheet for qPCR to ensure retinal tissue selection. During qPCR, tissue-sheets were stored for 3-4 days using a newly developed preservation method. In a rat tumorigenicity study, no transplant-related adverse events were observed. In retinal degeneration model rats, retinal transplants differentiated into mature photoreceptors and exhibited light responses in electrophysiology assays. These results demonstrate our rationale toward self-organizing retinal sheet transplantation therapy.

neuroscience↗