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Biology subjects

Miyachi, Y.

Publications and source records attributed to Miyachi, Y..

3 recordsLinked to original sources

SpliceSelectNet: A Hierarchical Transformer-Based Deep Learning Model for Splice Site Prediction

Accurate RNA splicing is essential for gene expression and protein function, yet the mechanisms governing splice site recognition remain incompletely understood. Aberrant splicing caused by mutations can lead to severe diseases, including cancer and genetic disorders, underscoring the need for accurate computational tools to predict splice sites and detect disruptions. Existing methods have made significant advances in splice site prediction but are often limited in handling long-range dependencies due to high computational costs, a factor critical to splicing regulation. Moreover, many models lack interpretability, hindering efforts to elucidate the underlying biological mechanisms. Here, we present SpliceSelectNet (SSNet), a hierarchical Transformer-based deep learning model that predicts splice sites from DNA sequences spanning up to 100 kb. By integrating local and global attention mechanisms, SSNet efficiently captures both proximal and distal regulatory signals while maintaining single-nucleotide resolution. Across multiple benchmark datasets, SSNet achieves state-of-the-art performance in splice site prediction and aberrant splicing detection. Systematic in-silico mutagenesis demonstrates that attention scores reflect functional sequence importance, supporting their biological relevance. Long-range sequence perturbation experiments further show that SSNet captures distal regulatory effects beyond conventional receptive fields. Together, these results establish SSNet as a biologically interpretable framework for modeling long-range splicing regulation from genomic sequence.

bioinformatics↗

Cyb5r3-based mechanism and reversal of secondary failure to sulfonylurea

Sulfonylureas (SU) are effective and affordable anti-diabetic drugs. But chronic use leads to secondary failure, limiting their utilization. The mechanism of secondary failure is unknown. Here we identify Cyb5r3 downregulation as a mechanism of SU failure and successfully reverse it. Chronic exposure to SU impairs Cyb5r3 levels and reduces islet glucose utilization with a metabolomics signature characterized by low acetyl-CoA and amino acid levels. Cyb5r3 engages in a glucose-dependent interaction that stabilizes glucokinase (Gck) to maintain glucose utilization. Accordingly, activating Gck mutations in patients with hyperinsulinemia reduce Cyb5r3 binding, whereas inactivating MODY mutations increase it, providing evidence for a role of Cyb5r3 in determining flux through Gck. The Cyb5r3 activator tetrahydroindenoindole (THII) rescues secondary failure to SU in an animal model of chronic SU treatment and restores insulin secretion from ex vivo islets. We conclude that Cyb5r3 loss-of-function is a key factor in the secondary failure to SU and a potential target for its prevention, which may lead to a rehabilitation of SU use in diabetes.

physiology↗

Antagonistic epistasis of Hnf4a and FoxO1 networks through enhancer interactionsin beta-cell function

Genetic and acquired abnormalities contribute to pancreatic {beta}-cell failure in diabetes. Transcription factors Hnf4 (MODY1) and FoxO1 are respective examples of these two components, and are known to act through {beta}-cell-specific enhancers. However, their relationship is unclear. Here we show by genome-wide interrogation of chromatin modifications that FoxO1 ablation in mature {beta}-cells leads to increased selection of FoxO1 enhancers by Hnf4. To model the functional significance we generated single and compound knockouts of FoxO1 and Hnf4 in {beta}-cells. Single knockout of either gene impaired insulin secretion in mechanistically distinct fashions. Surprisingly, the defective {beta}-cell secretory function of either single mutant in hyperglycemic clamps and isolated islets treated with various secretagogues, was completely reversed in double mutants. Gene expression analyses revealed the reversal of {beta}-cell dysfunction with an antagonistic network regulating glycolysis, including {beta}-cell "disallowed" genes; and that a synergistic network regulating protocadherins emerged as likely mediators of the functional restoration of insulin secretion. The findings provide evidence of antagonistic epistasis as a model of gene/environment interactions in the pathogenesis of {beta}-cell dysfunction.

pathology↗