Sexual Dimorphism in Placental mTORC1 Signaling, Amino Acid Transport, and Mitochondrial Respiration at Term.

Shimada H, Sakuragi T, Zaegel V et al. · 2026 · Antioxidants · Atlas ID SHIMADA2026

What this study shows

In 46 term placentas, male placentas showed higher mTORC1 signalling (increased S6RP phosphorylation, reduced 4E-BP1), greater System A amino acid transport and higher mitochondrial respiratory capacity than female placentas, correlating with a higher birth-weight-to-placental-weight ratio. Observational: a cross-sectional association at a single timepoint, with no intervention and no randomisation, so the direction of the relationship between mTORC1 signalling and growth is not established here and residual confounding by maternal and obstetric factors cannot be excluded.

Abstract

ShowHide

Male fetuses generally grow faster in utero and are heavier at birth than females, whereas perinatal mortality and morbidity are often higher in boys. Placentas were collected from 46 women with uncomplicated pregnancies delivering appropriate-for-gestational-age infants (23 female, 23 male). In homogenates of male placentas, phosphorylation of S6RP (Ser235/236) was increased and total 4E-BP1 protein expression reduced compared with female placentas, indicating enhanced mTORC1 signalling.

Read the full abstract on PubMed →

At a glance

Evidence type	H Human study Marked H because it is direct evidence from a human clinical trial or human cohort; the code names the kind of study, not its quality -- a small, well-run trial is still H.
Study type	3 - Human Observational
Model system	Human placenta at term (n=46)
Journal	Antioxidants
Year	2026
Peer reviewed	Yes
Record last updated	2026-08-22
Source	DOI 10.3390/antiox15080977 · PMID 42650242 · Free full text (PMC13509233)

Extracted findings

Intervention	None (observational comparison by fetal sex)
Target	mTORC1; S6RP; 4E-BP1; System A amino acid transport
Model	Human
Effect	Higher mTORC1 activity, amino acid transport and mitochondrial respiratory capacity in male placentas; higher birth-weight-to-placental-weight ratio

Cite this paper

ShowHide

Shimada, H., et al. (2026). Sexual Dimorphism in Placental mTORC1 Signaling, Amino Acid Transport, and Mitochondrial Respiration at Term. Antioxidants. https://doi.org/10.3390/antiox15080977

@article{SHIMADA2026,
  author       = {Shimada, H. and Sakuragi, T. and Zaegel, V. and others},
  title        = {{Sexual Dimorphism in Placental mTORC1 Signaling, Amino Acid Transport, and Mitochondrial Respiration at Term}},
  journal      = {Antioxidants},
  year         = {2026},
  doi          = {10.3390/antiox15080977},
  note         = {PMID: 42650242},
}

Cite this Atlas record

The record is the Atlas's own work — the evidence label, the extracted findings and the links. It is cited as part of the dataset, not as the paper.

Barton, O. (2026). Oliver's mTOR Atlas (record SHIMADA2026) [Data set]. https://mtor-atlas.org/study/SHIMADA2026/ · Dataset DOI 10.5281/zenodo.22059963

@misc{atlas_SHIMADA2026,
  author       = {Barton, Oliver},
  title        = {{Oliver's mTOR Atlas}, record SHIMADA2026},
  howpublished = {Data set},
  year         = {2026},
  url          = {https://mtor-atlas.org/study/SHIMADA2026/},
  doi          = {10.5281/zenodo.22059963}
}