Placental powerhouses: Links between physical activity, tissue location and mitochondrial properties

This is the authors' abstract. We don't add key points for this paper.

Physical activity (PA) during pregnancy can result in health benefits for both the mother and fetus, potentially mediated by molecular changes in placental physiology. One organelle that may play a key role is the mitochondrion, but there is limited data on placental mitochondria. In particular, the relationship between PA and mitochondrial characteristics across different placental regions (central vs. peripheral) has not been explored, despite numerous known physiological differences. We aim to examine associations between maternal PA and placental tissue location with key mitochondrial parameters. Central and peripheral placental tissue samples were collected from healthy pregnancies. Pregnancies were classified as either active or inactive based on objectively measured PA levels at mid-gestation. Mitochondrial complexes (CI-CV), SOD1, SOD2, OPA1, and DRP1 were measured by Western blot. Mitochondrial DNA (mtDNA) copy number, and function (via high-resolution respirometry), were also assessed. Activity status was significantly associated with greater peripheral CII protein expression ( p = 0.014) and central SOD1 protein expression ( p = 0.029), and with higher state 3 (S3) respiration (a measure of oxidative phosphorylation capacity) in central mitochondria ( p = 0.015); no other characteristics were significant. Our within-group comparison based on tissue location showed significant differences for SOD1 and complexes I, II, III, and V in the active group, and for CI, CII, and CIII in the inactive group. No differences in mtDNA (trend noted) or other mitochondrial function measures were found. Overall, this data from our small but well-phenotyped sample provides novel insights into how mitochondrial characteristics may respond to PA during pregnancy and how they may differ between central and peripheral placental tissues.