Single-cell RNA transcriptomics in mice reveals embryonic origin of fi brosis due to maternal obesity

Background Over 40% of pregnant women in the USA are obese which negatively affects fetal development and offspring health. Maternal obesity (MO) leads to fi brotic infiltration in multiple tissues and organs of offspring during their adulthood although the origin and mechanisms are unclear. Methods C57BL/6J female mice were fed a control and high-fat diet to mimic MO condition. Embryonic somatic tissues were obtained at E9.5, E11.5, and E13.5 (equivalent to 6 weeks of human pregnancy) from control (CON) and MO mice for single-cell RNA-sequencing (scRNA-seq). To explore the role of AMP-activated protein kinase (AMPK), AMPK was activated by metformin and A769662, and knocked out in embryonic mesenchymal cells (EMC) using AMPK alpha 1 fl oxed mice. Findings Using unsupervised clustering, we identified three major cell populations with fi brogenic capacity. Compared to CON, the population of fi brogenic cells increased dramatically (by similar to 125%) due to MO, supporting an embryonic origin of fi brosis in the offspring. MO induced inflammatory response and elevated expression of transforming growth factor (3 (TGF(3) signalling and fi brogenic genes in embryos. MO inhibited AMPK and its activation by metformin and A769662 inhibited TGF(3 signalling and fi brogenesis. Interpretation MO profoundly enhances embryonic fi brogenesis, explaining the origin of fi brosis in the offspring of mothers living with obesity. Our data underscore the importance of early intervention, before 5-6 weeks of pregnancy, in improving embryonic development, and AMPK is an amiable target for suppressing excessive fi brogenesis in MO embryos to assist increasing populations of obese mothers having healthy children. Funding This work was funded by National Institutes of Health Grant R01HD067449. Copyright (c) 2024 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).