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Biology subjects

Masuyama, T.

Publications and source records attributed to Masuyama, T..

2 recordsLinked to original sources

Cold adaptation in Upper Paleolithic hunter-gatherers of eastern Eurasia

Previous genomic studies understanding the dispersal of Homo sapiens have suggested that present-day East Eurasians and Native Americans can trace their ancestry to migrations from Southeast Asia. However, ineluctable adaptations during the Last Glacial Maximum (LGM) remain unclear. By analyzing 42 genomes of up to 30-fold coverage from prehistoric hunter-gatherers, Jomon, we reveal their descent from Upper Paleolithic (UP) foragers who migrated to and isolated in the Japanese archipelago during Late Pleistocene. We provide compelling evidence suggesting that these UP people underwent positive selection for cold environments, aiding their survival through the LGM facilitated by non-shivering thermogenesis and detecting it polygenically across multiple loci in the Jomon lineage. Our study pioneers the close estimation of the physiological adaptation of ancient humans by the paleogenomic approach.

evolutionary biology↗

Iron Deficiency Induces Heart Failure with Ectopic Cardiac Calcification in Mice with Metabolic Syndrome

Iron deficiency is linked to worse clinical status and outcomes in heart failure. Although metabolic syndrome contributes to the development of heart failure, the impact of iron deficiency in heart failure complicated with metabolic syndrome remains obscure. KKAy mice were used as a model of metabolic syndrome. Four-week-old male C57BL/6J and KKAy mice were fed either a normal diet or iron-restricted (IR) diet for 12 weeks. During the experiment, 40% of mice died due to pulmonary congestion in KKAy mice with IR diet (KKAy-IR), while no mice died in other groups. Necropsy showed the presence of multiple white lesions on the cardiac surface in those KKAy-IR mice. Echocardiography and histological analyses revealed that KKAy-IR mice exhibited cardiac hypertrophy and cardiac dysfunction with cardiac calcification. Cardiac mRNA of ectonucleotide pyrophosphatase/phosphodiesterase-1 (Enpp1), a key enzyme for bone mineralization, was highly abundant in KKAy-IR mice. Of note, iron restriction-induced cardiac calcification and dysfunction were attenuated by etidronate, an inhibitor of bone mineralization, with decreased cardiac Enpp1 mRNA abundance in KKAy-IR mice. In conclusion, iron deficiency leads to ectopic cardiac calcification and dysfunction with the increase of Enpp1 in metabolic syndrome model mice.

pathology↗