Interaction Between Sympk and Oct4 Promotes Mouse Embryonic Stem Cell Proliferation

• Published in: Stem cells (Dayton, Ohio) Vol. 37; no. 6; pp. 743 - 753
• Main Authors: Yu, Jianping, Lu, Weisi, Ge, Tianyu, Huang, Rui, Chen, Bohong, Ye, Miaoman, Bai, Yaofu, Shi, Guang, Songyang, Zhou, Ma, Wenbin, Huang, Junjiu
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01-06-2019; Oxford University Press
• Subjects: Animals; Cell Differentiation; Cell Line; Cell Proliferation; Cell self-renewal; Clonal deletion; Colonies; CRISPR; CRISPR-Cas Systems; Depletion; Differentiation; Embryo cells; Embryonic stem cells; Gene Deletion; Gene Expression Profiling; Gene Expression Regulation, Developmental; Genes; Genes, Reporter; Genome; Genomes; Genomic Instability; Genomic stability; Green Fluorescent Proteins - genetics; Green Fluorescent Proteins - metabolism; Mice; Mouse Embryonic Stem Cells - cytology; Mouse Embryonic Stem Cells - metabolism; Nuclear Proteins - deficiency; Nuclear Proteins - genetics; Oct-4 protein; Oct4; Octamer Transcription Factor-3 - genetics; Octamer Transcription Factor-3 - metabolism; Pluripotency; Pluripotent Stem Cells - cytology; Pluripotent Stem Cells - metabolism; Polyadenylation; Proliferation; Ribonucleic acid; RNA; Signal Transduction; Stability analysis; Stem cell transplantation; Stem cells; Symplekin; Teratoma; Teratoma - genetics; Teratoma - metabolism; Teratoma - pathology; Tight junctions; Tight Junctions - metabolism; Transcription; Oct4; Genomic stability; Proliferation; Symplekin; Embryonic stem cells; Pluripotency
• ISSN: 1066-5099; 1549-4918
• DOI: 10.1002/stem.2992

The scaffold protein Symplekin (Sympk) is involved in cytoplasmic RNA polyadenylation, transcriptional modulation, and the regulation of epithelial differentiation and proliferation via tight junctions. It is highly expressed in embryonic stem cells (ESCs), in which its role remains unknown. In this study, we found Sympk overexpression in mouse ESCs significantly increased colony formation, and Sympk deletion via CRISPR/Cas9 decreased colony formation. Sympk promoted ESC growth and its overexpression sustained ESC pluripotency, as assessed by teratoma and chimeric mouse formation. Genomic stability was preserved in these cells after long‐term passage. The domain of unknown function 3453 (DUF3453) in Sympk was required for its interaction with the key pluripotent factor Oct4, and its depletion led to impaired colony formation. Sympk activated proliferation‐related genes and suppressed differentiation‐related genes. Our results indicate that Sympk interacts with Oct4 to promote self‐renewal and pluripotency in ESCs and preserves genome integrity; accordingly, it has potential value for stem cell therapies. Stem Cells 2019;37:743–753
Large expansion of embryonic stem cells sustaining stemness and genomic stability is a bottleneck before meeting the demands of clinical transplantation. Here, we found a scaffold protein Symplekin is enriched in mouse embryonic stem cells. Its overexpression enhanced cell proliferation, maintained pluripotency and genomic stability during long‐term culture both in vitro and in vivo, whereas its deficiency impaired mouse embryonic stem cells self‐renewability. Mechanistically, the DUF3453 domain of Symplekin was sufficient for its binding with the key pluripotency factor Oct4 and essential for mouse embryonic stem cell colony formation. Finally, Symplekin could promote genome‐wide proliferative genes and inhibit differentiation genes. Thus, Symplekin is a potential candidate for optimizing embryonic stem cell culture and expansion.