Hiroshi Shimada
Obstetrician-scientist from Sapporo Medical University working in the Colorado placenta group of Thomas Jansson, Theresa Powell and Fredrick Rosario on how mTOR controls nutrient transport to the fetus
Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus (2024–2026) · Visiting researcher, Faculty of Medicine, Sapporo Medical University (2020, 2026) · Researcher, Faculty of Medicine, Sapporo Medical University (2019)
The placenta decides how much food reaches a growing baby, and mTORC1, the cell's nutrient and growth sensor, helps set how fast it pumps amino acids across. In the 2026 study led by Hiroshi Shimada, with Fredrick Rosario as senior author, the team compared 46 placentas from healthy term pregnancies. Placentas from boys showed stronger mTORC1 signalling, more System A amino acid transport and higher mitochondrial respiration than placentas from girls, and boys had a higher birth weight relative to placental weight.
This was a snapshot at one time point with no treatment, so it shows an association between fetal sex and placental function, not a cause. It does suggest that male and female pregnancies may need to be analysed separately in placental research.
Shimada is listed by PubMed with both the University of Colorado Anschutz Medical Campus and Sapporo Medical University in Japan. Earlier work in the Colorado group includes a 2024 review on how placental amino acid transporters are regulated, with mTOR as a key regulator, and a 2025 mouse study in which switching off mTOR only in placental trophoblast cells cut the transport of folate to the fetus and reduced fetal growth.
The Japanese national research database KAKEN lists Shimada at the Faculty of Medicine of Sapporo Medical University, as a researcher in 2019 and as a visiting researcher in 2020 and 2026, in the field of obstetrics and gynecology. There Shimada led an early-career grant from 2019 to 2020 to study how endometriosis, the growth of womb-lining tissue outside the womb, develops, using a new disease model.
Milestones in the Atlas
A selection, not a full bibliography: only papers that meet the Atlas inclusion criteria.
| Year | Evidence | Study |
|---|---|---|
| 2026 | H | Sexual Dimorphism in Placental mTORC1 Signaling, Amino Acid Transport, and Mitochondrial Respiration at Term. SHIMADA2026 First author: compared 46 term placentas and found higher mTORC1 signalling, amino acid transport and mitochondrial respiration in placentas from male pregnancies. |
Co-authors in the Atlas 1
People with a profile here who share at least one study with Hiroshi Shimada.
ShowHide
- Fredrick J. Rosario Studies how mTOR signalling in the placenta controls the transport of amino acids and folate to the fetus
Every researcher with a profile →
Thank you. That helps us know which pages have been read by someone who knows the work.
Thank you. We will check it and correct the page.
Thank you. Your answer was counted anonymously.