Biology subjects

Takita, J.

Publications and source records attributed to Takita, J..

3 recordsLinked to original sources

bioRxiv2026

Personalized reference genome-based pipeline reveals comprehensive haplotype-resolved views of cancer genomes

Cancer genome analysis relies on standard human reference genomes, but detecting somatic alterations in highly repetitive or individual-specific regions remains challenging. We developed the Personalized Reference genome-based Cancer Genome Analysis Pipeline (PRCGAP, https://github.com/yos-sk/PRCGAP), to our knowledge, the first comprehensive pipeline integrating haplotype-resolved analyses of somatic point mutations, structural variants, copy number, and DNA methylation on personalized diploid reference genomes, with each variant phased and annotated by genomic features. We applied PRCGAP to eight tumor-normal cell line pairs and three newly collected pediatric B-cell acute lymphoblastic leukemia (B-ALL) clinical samples. PRCGAP recovered most standard reference-based variants (86.7-96.4% across variant types), validated by orthogonal short-read sequencing, while additionally detecting variants that standard references missed (23.4% of SNVs and 32.6% of SVs). Notably, PRCGAP uncovered variants in centromeric and telomeric regions, and somatic single-nucleotide variants were enriched in centromere dip regions, the putative kinetochore formation sites. Using PRCGAP outputs, we identified L1 retrotransposition source sites absent from standard references and showed that a B-ALL IGH::DUX4 fusion arose from a DUX4 pseudogene within an internal D4Z4 repeat unit, rather than the canonical full-length DUX4 gene. Within a single haplotype-resolved framework, PRCGAP opens regions of the cancer genome that are inaccessible to standard references.

bioinformatics↗

bioRxiv2023

HOIL-1L deficiency induces cell cycle alteration which causes immaturity of myocyte and fibrogenesis

HOIL-1L deficiency was recently reported to be one of the causes of myopathy and dilated cardiomyopathy (DCM). However, the mechanisms by which myopathy and DCM develop have not been clearly elucidated. Here, we sought to elucidate these mechanisms using the murine myoblast cell line C2C12 and disease-specific human induced pluripotent stem cells (hiPSCs). Myotubes were differentiated from control and HOIL-1L-KO C2C12 cells. Cardiomyocytes (CMs) were differentiated from control and patient-derived hiPSCs. We investigated the impact of HOIL-1L on differentiation of myotubes and CMs. Myotubes differentiated from HOIL-1L-KO C2C12 cells exhibited deteriorated differentiation and mitotic cell accumulation. CMs differentiaed from patient-derived hiPSCs had an abnormal morphology with a larger size and were excessively multinucleated compared with CMs differentiaed from control hiPSCs. Further analysis of hiPSC- derived CMs showed that HOIL-1L deficiency caused cell cycle alteration and mitotic cell accumulation. These results were supported by RNA sequencing of C2C12 cell-derived myotubes. In addition, SerpinE2, a cardiac fibrogenesis gene, was significantly upregulated in CMs differentiaed from patient-derived hiPSCs. These results demonstrate that abnormal cell maturation and fibrosis possibly contribute to the development of DCM and myopathy. In conclusion, HOIL-1L is an important intrinsic regulator of cell cycle-related myotube and CM maturation and cell proliferation.

cell biology↗

bioRxiv2021

Aberrant localization of CDC42 C-terminal variants to the Golgi apparatus drives pyrin inflammasome-dependent autoinflammation

Mutations in the C-terminal region of the CDC42 gene cause severe neonatal-onset autoinflammation. Elevated levels of serum IL-18 in patients and effectiveness of IL-1{beta}-blocking therapy indicate that the pathology involves abnormal inflammasome activation; however, the mechanism underlying autoinflammation remains to be elucidated. Using induced-pluripotent stem cells established from patients carrying CDC42R186C, we found that patient-derived cells secreted larger amounts of IL-1{beta} in response to pyrin-activating stimuli. Aberrant palmitoylation and localization of CDC42R186C protein to the Golgi apparatus promoted pyrin inflammasome assembly downstream of pyrin dephosphorylation. Aberrant subcellular localization was the common pathological feature shared by CDC42 C-terminal variants with inflammatory phenotypes, including CDC42*192C*24 that also localizes to the Golgi apparatus. Furthermore, the level of pyrin inflammasome overactivation paralleled that of mutant protein accumulation in the Golgi apparatus, but no that of the mutant GTPase activity. These results reveal an unexpected association between CDC42 subcellular localization and pyrin inflammasome activation that could pave way for elucidating the mechanism of pyrin inflammasome formation.

immunology↗