Maternal age is a critical factor influencing female fertility, often leading to diminished reproductive outcomes as age advances. A recently published study by a collaborative research team from Chongqing Medical University and Tongji University has shed new light on the molecular underpinnings linking maternal aging to impaired early embryonic development. Their groundbreaking work uncovers how autophagy—a fundamental cellular degradation and recycling mechanism—declines with maternal aging and how this decline disrupts embryonic metabolism, ultimately derailing developmental potential.
Autophagy serves as a cellular housekeeping process, essential for removing damaged organelles and recycling macromolecules to maintain metabolic homeostasis. This function is particularly vital during embryogenesis when rapid cell divisions and differentiation demand tight metabolic regulation. The research illustrates that in embryos from aged female mice, autophagic activity is markedly reduced. Notably, administration of Rapamycin, a potent autophagy activator, in the culture medium partially restored early developmental competence, underscoring the pivotal role of autophagy in embryonic viability under aging-induced metabolic stress.
Intriguingly, the team employed comprehensive non-targeted lipidomics and proteomics approaches that unveiled enhanced fatty acid β-oxidation (β-FAO) in embryos from aged females. This metabolic shift, characterized by elevated breakdown of fatty acids in mitochondria to produce energy, paradoxically correlated with low autophagy levels. Mechanistically, the study reveals a regulatory axis involving the autophagy protein LC3B and ACOX1, a peroxisomal enzyme integral to fatty acid β-oxidation. Reduced autophagy impairs LC3B-dependent degradation of ACOX1, leading to its accumulation and subsequent hyperactivation of β-FAO pathways.
Further validating these insights, overexpression of Acox1 hampered blastocyst formation rates, signaling compromised embryonic development, whereas targeted knockdown of Acox1 in low-autophagy embryos partially rescued developmental outcomes. These findings place autophagy-mediated regulation of β-FAO at the core of embryonic competency decline during maternal aging, highlighting a carefully balanced metabolic repertoire essential for development.
Expanding beyond metabolic alterations, the research incorporated next-generation sequencing techniques including RNA-seq, Cut&Tag, and ATAC-seq to capture the epigenomic landscape within these embryos. A pivotal discovery emerged linking hyperactive β-FAO to excessive consumption of oxidized nicotinamide adenine dinucleotide (NAD+), a crucial coenzyme in redox reactions. This NAD+ depletion disrupted the erasure of histone H3 lysine 9 acetylation (H3K9ac), a key epigenetic modification required for proper timing of minor zygotic genome activation (ZGA) exit during early embryogenesis.
The failure to reset H3K9ac impeded the embryo’s ability to exit minor ZGA in a timely manner, which is essential for transitioning control of gene expression to the embryonic genome. This epigenetic interference was directly linked to developmental defects observed in embryos from aged females, illustrating how metabolic dysfunction reverberates through chromatin regulation to sabotage embryonic progression.
Crucially, the research team extended their observations to human embryos derived from women of advanced maternal age, confirming that this autophagy-β-FAO-NAD+-histone acetylation axis is conserved evolutionarily and clinically relevant. This underscores the translational potential of these findings in guiding new therapeutic interventions to enhance fertility outcomes in aging populations.
By linking fundamental cellular degradation processes, metabolic homeostasis, and epigenetic regulation within the context of maternal aging, this study provides an integrated mechanistic framework that has long eluded reproductive biology. Importantly, it opens avenues for metabolic modulation strategies—such as autophagy activation or targeted β-FAO regulation—to rescue embryonic developmental competence in aged females.
In light of this work, future clinical approaches may entail optimizing culture conditions with autophagy activators or fine-tuning fatty acid metabolism to restore NAD+ availability and ensure appropriate epigenetic remodeling during early development. Such interventions hold promise not only for improving Assisted Reproductive Technology (ART) outcomes but also for mitigating natural fertility decline, a pressing issue given global demographic trends toward delayed childbearing.
Furthermore, this study invites deeper investigation into how other metabolic pathways might intersect with chromatin dynamics during embryogenesis and how maternal systemic factors influence these delicate processes. The broad implications for developmental biology, epigenetics, and reproductive medicine signify a paradigm shift in understanding and potentially controlling the molecular consequences of maternal aging.
The collaborative efforts of Prof. Jingyu Li, Prof. Shimeng Guo, Prof. Guoning Huang, and Shaorong Gao reflect a powerful synergy combining molecular biology, multi-omics technologies, and clinical perspectives, culminating in findings published in Science Bulletin. This seminal research charts a roadmap for future exploration of metabolic-epigenetic crosstalk in reproductive aging and sparks hope for innovative fertility-preserving therapies.
As the field advances, unraveling how autophagy interacts with diverse metabolic circuits will be pivotal for designing holistic interventions that safeguard embryonic integrity amidst the challenges posed by maternal aging. Ultimately, this integrative insight bridges gaps between cellular metabolism, chromatin biology, and developmental competence, promising transformative impacts on reproductive health and longevity.
Subject of Research:
Maternal aging-related decline in embryonic development mediated by autophagy-dependent metabolic and epigenetic dysregulation.
Article Title:
Autophagy-dependent disruption of β-FAO-mediated histone acetylation in embryos during maternal aging
News Publication Date:
2-May-2026
Web References:
http://dx.doi.org/10.1016/j.scib.2026.02.053
Keywords:
Autophagy, maternal aging, early embryonic development, fatty acid β-oxidation, ACOX1, histone acetylation, NAD+, zygotic genome activation, epigenetics, metabolic regulation, reproductive biology, assisted reproductive technology
