Biology subjects

Katagiri, C.

Publications and source records attributed to Katagiri, C..

3 recordsLinked to original sources

bioRxiv2026

IF1 restrains excessive elevation of the mitochondrial membrane potential and safeguards the epithelial state of human induced pluripotent stem cells

Human pluripotent stem cells (hPSCs) rely on glycolysis and exhibit low mitochondrial respiration, conditions under which F1Fo ATP synthase tends to run in reverse, hydrolyzing ATP. ATP synthase inhibitory factor subunit 1 (IF1) inhibits F1Fo-mediated ATP hydrolysis, but its significance in glycolytic hPSCs remains unclear. Here, we show that stable IF1 knockdown (IF1-KD) in human induced pluripotent stem cells (hiPSCs) enhanced mitochondrial ATP hydrolysis and elevated the mitochondrial membrane potential ({Delta}{Psi}m). Markers of the undifferentiated state were largely maintained, whereas IF1-KD cells exhibited reduced epithelial characteristics and a partial epithelial-mesenchymal transition (EMT)-like state. IF1-KD cells also showed enhanced store-operated Ca2 entry (SOCE) and increased nuclear NFATc3. Pharmacological reduction of {Delta}{Psi}m attenuated SOCE, whereas NFATc3 overexpression reproduced key features of the EMT-like expression pattern. Endogenous IF1 therefore acts as a constitutive restraint on reverse-mode F1Fo activity, limiting excessive {Delta}{Psi}m and downstream SOCE-NFATc3 signaling and safeguarding the epithelial state of hPSCs.

Cell Biology↗

bioRxiv2026

Ancient Ryukyu Jomon contributed to past and current genetic structure of Japanese populations

Characterized by the earliest use of pottery, the Jomon culture was a unique Neolithic culture that spread throughout the Japanese Archipelago. Previous archaeological evidence suggests that Jomon hunter-gatherers colonized the southernmost islands, the Ryukyu Archipelago, by approximately 7,000 years before present (YBP). However, genetic characteristics of the Ryukyu Jomon population and its contribution to the modern population have not been elucidated yet. In this study, we newly sequenced 273 modern and 25 ancient (6,700-900 YBP) whole genomes collected across the Ryukyu Archipelago. Our analysis demonstrated a genetic differentiation between the Hondo (Japanese mainland) and Ryukyu Jomon, dating back to [~]6,900 YBP. After the divergence from the Hondo Jomon, the Ryukyu Jomon experienced severe bottlenecks, with an effective population size of [~]2,000. Admixture between the Ryukyu Jomon and migrants from the historic Hondo population occurred [~]1,000 YBP, which corresponds to the widespread adoption of iron tools and agriculture in the Central Ryukyus. Different demographic histories between modern Hondo and Ryukyu populations resulted in different rates of Jomon ancestry in these populations. By providing a new perspective on the peopling of the Ryukyu Archipelago, this study significantly enhances our understanding of cultural transitions in the region.

evolutionary biology↗

bioRxiv2021

Ancient genomes from the last three millennia support multiple human dispersals into Wallacea

Previous research indicates that the human genetic diversity found in Wallacea - islands in present-day Eastern Indonesia and Timor-Leste that were never part of the Sunda or Sahul continental shelves - has been shaped by complex interactions between migrating Austronesian farmers and indigenous hunter-gatherer communities. Here, we provide new insights into this regions demographic history based on genome-wide data from 16 ancient individuals (2600-250 yrs BP) from islands of the North Moluccas, Sulawesi, and East Nusa Tenggara. While the ancestry of individuals from the northern islands fit earlier views of contact between groups related to the Austronesian expansion and the first colonization of Sahul, the ancestry of individuals from the southern islands revealed additional contributions from Mainland Southeast Asia, which seems to predate the Austronesian admixture in the region. Admixture time estimates for the oldest individuals of Wallacea are closer to archaeological estimates for the Austronesian arrival into the region than are admixture time estimates for present-day groups. The decreasing trend in admixture times exhibited by younger individuals supports a scenario of multiple or continuous admixture involving Papuan- and Asian-related groups. Our results clarify previously debated times of admixture and suggest that the Neolithic dispersals into Island Southeast Asia are associated with the spread of multiple genetic ancestries.

genomics↗