New Mechanism of Pluripotency Exit in Porcine Embryonic Stem Cells for Breeding and Regenerative Medicine

Embryonic stem cells (ESCs) are valued for their ability to self-renew indefinitely while retaining the potential to generate all somatic cell types. For pigs—a key biomedical and agricultural model—understanding how stem cells transition from pluripotency to differentiation has major implications for both regenerative medicine and genetic breeding. Yet, the precise molecular drivers of this transition have remained elusive.

In a new study published in Fundamental Research, a team led by Yi-Liang Miao, a professor at Huazhong Agricultural University, has pinpointed PIAS4, an E3 ubiquitin ligase, as a pivotal regulator of pluripotency exit in porcine embryonic stem cells.

“Exiting pluripotency is a decisive moment for stem cells, marking the point at which they embark on a path toward specialized fates,” explains Miao. “Our work shows that PIAS4 is a master switch in this process.”

The team's approach combined high-throughput genetics with chromatin profiling:

1. CRISPR-based genome-wide screen: Using the CRISPR/Cas9 library screening of all E3 ubiquitin enzymes in pigs, the researchers identified PIAS4 as a top candidate essential for pluripotency exit. Cells lacking PIAS4 failed to downregulate pluripotency markers and remained trapped in an undifferentiated state.
2. Epigenetic mechanism: Further analyses revealed that PIAS4 interacts with the histone demethylase KDM5B, enhancing its stability through SUMOylation. This cooperation enables fine-tuned control of H3K4me3, a histone mark critical for activating lineage-specific genes.
3. LEFTY2–SMAD axis: The study also uncovered a downstream pathway in which PIAS4 suppresses LEFTY2 expression, thereby promoting SMAD2/3 phosphorylation and guiding mesendoderm specification.

“Our results highlight PIAS4 as a gatekeeper of pluripotency exit,” adds Prof. Miao. “Harnessing this knowledge could accelerate advances in both regenerative therapies and animal biotechnology.”

Beyond basic science, the implications are wide ranging. Porcine ESCs hold promise for xenotransplantation, disease modeling, precision breeding, and even cultured meat production.

Contact author:  Yi-Liang Miao, Institute of Stem Cell and Regenerative Biology, College of Animal Science and Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China, miaoyl@mail.hzau.edu.cn; Jilong Zhou, Institute of Stem Cell and Regenerative Biology, College of Animal Science and Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China, zhoujilong@mail.hzau.edu.cn

Funder: This work was supported by the National Key R&D Program of China (2022YFD1302200), Scientific Innovation 2030 Project (2023ZD04072, 2023ZD0404703), the Natural Science Foundation of Hubei Province (2022CFB149), the Fundamental Research Funds for the Central Universities (2662023DKPY001) and the Special Research Project on Experimental Animal of Hubei Province (2023CFA006).

Conflict of interest: The authors declare that they have no conflicts of interest in this work.

See the article: Qin W, Wang Y, Duan H F, et al. PIAS4 regulates pluripotency exit and cell fate commitment in porcine embryonic stem cells [J]. Fundamental Research, Volume 5, Issue 4, July 2025, Pages 1556-1569, https://doi.org/10.1016/j.fmre.2024.10.016.