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Doerflinger, N.

Publications and source records attributed to Doerflinger, N..

6 recordsLinked to original sources

Netrin-1 Acts as a Guardian of Naive Pluripotency in Human Embryonic Stem Cells

We investigated the role of Netrin-1 (NTN1) in human naive pluripotency using complementary loss- and gain-of-function approaches. In primate embryos and human embryonic stem cells (hESCs), Netrin-1 expression is associated with the naive pluripotent state. Disruption of NTN1 had no detectable effect on hESCs maintained on murine embryonic fibroblasts. However, under sub-optimal culture conditions, NTN1-knockout cells exhibited compromised naive pluripotency, which was rescued with feeder cells overexpressing Netrin-1. Netrin-1 overexpression in hESCs accelerated acquisition of the naive state and markedly increased resistance to differentiation. These effects were accompanied by extensive epigenetic remodeling, including H3K27ac and H2K27me3. Proteomic and phospho-proteomic analyses further revealed rapid Netrin-1-dependent alterations in pathways controlling cell adhesion, signaling, and chromatin regulation. Together, these findings extend the role of Netrin-1 beyond its established functions and identify it as a coordinator of extracellular cues, intracellular signaling, and nuclear regulatory mechanisms that support human naive pluripotency.

cell biology↗

A STAT3-regulated lncRNA integrates microRNA biogenesis and sequestration to safeguard naive pluripotency

Leukemia inhibitory factor (LIF)/STAT3 signaling is central to maintaining naive pluripotency in mouse embryonic stem cells (mESCs). We identify Asgard, a previously uncharacterized long non-coding RNA, as a direct STAT3 target required for efficient self-renewal. Asgard is rapidly induced by LIF, enriched in the epiblast, and its depletion reduces alkaline phosphatase-positive colony formation while enhancing differentiation. Mechanistically, Asgard fulfils a dual role: it acts as the primary transcript for the differentiation-promoting microRNA Odin, while also functioning as a sponge to sequester Odin and related miRNAs. This dual mechanism enables Asgard to both generate and buffer pro-differentiation signals, thereby stabilizing the pluripotent state while preserving responsiveness to lineage cues. Our work reveals a new paradigm in RNA-mediated control of stem cell identity, where a single STAT3-regulated lncRNA couples microRNA production with competitive inhibition to safeguard naive pluripotency.

developmental biology↗

Identification of novel candidate regulators of human naive pluripotency by means of a genetic switch utilizing the chimeric receptor G-CSFR:GP130

This study investigated the molecular mechanisms underpinning the transition from primed to naive pluripotency in human pluripotent stem cells (hPSCs) by utilizing a dual genetic switch combining hormone-dependent STAT3-ERT2 and a chimeric GCSFR:gp130 receptor. Upon activation with tamoxifen and G-CSF, hPSCs demonstrated upregulation of naive markers, and sustained self-renewal independent of LIF. Transcriptomic analyses revealed distinct clusters of early response genes, with a subset of 26 genes significantly enriched in the human epiblast. Knockdown experiments further delineated essential regulators that modulate differentiation and proliferation during naive reprogramming including interferon gamma inducible protein (IFI)16 and interferon-induced transmembrane (IFITM) proteins. Moreover, functional assays using mutant chimeric GCSFR:gp130 receptor highlighted the critical role of JAK kinase recruitment in orchestrating epigenomic remodeling and early gene activation. This approach establishes a robust platform to dissect the signaling dynamics governing the accession of hPSCs to naive pluripotency.

cell biology↗

Generation of systemic rabbit chimeras via Induced Pluripotent Stem Cells Reprogrammed with KLF2, ERAS, and PRMT6

Little is known about the molecular underpinnings of pluripotent stem cells (PSCs) ability to colonize the epiblast of preimplantation embryos and generate chimeras. In our study, using rabbit PSCs as a model system, we conducted unbiased screening of a cDNA library that encodes a panel of 36 pluripotency factors. From this screening, we identified KLF2, ERAS and PRMT6, whose overexpression confers the ability for self-renewal in a KOSR/FGF2-free culture medium supplemented with LIF, activin A, PKC and WNT inhibitors. The reprogrammed cells acquired transcriptomic and epigenetic features of naive pluripotency, including the reactivation of the 2nd X-chromosome. Leveraging these PSC lines, we determined the transcriptomic signature of embryonic colonization-competence, demonstrating transcriptional repression of genes involved in MAPK, WNT, HIPPO, and EPH signaling pathways, alongside the activation of genes involved in amino-acid metabolism, NF-kB signaling, and p53 pathway. Remarkably, a subset of reprogrammed cells, expressing CD75 at a high level, gained the ability to produce chimeric fetuses with a high contribution from PSCs in all lineages.

cell biology↗

Primate naive pluripotent stem cells stall in the G1 phase of the cell cycle and differentiate prematurely during embryo colonization

After reprogramming to naive pluripotency, human pluripotent stem cells (PSCs) still exhibit very low ability to make interspecies chimeras. Whether this is because they are inherently devoid of the attributes of chimeric competency or because naive PSCs cannot colonize embryos from distant species remains to be elucidated. Here, we have used different types of mouse, human and rhesus monkey naive PSCs and analyzed their ability to colonize rabbit and cynomolgus monkey embryos. Mouse embryonic stem cells (ESCs) remained mitotically active and efficiently colonized host embryos. In contrast, primate naive PSCs colonized host embryos with much lower efficiency. Unlike mouse ESCs, they slowed DNA replication after dissociation and, after injection into host embryos, they stalled in the G1 phase and differentiated prematurely, regardless of host species. We conclude that human and non-human primate naive PSCs do not efficiently make chimeras because they are inherently unfit to remain mitotically active during colonization.

cell biology↗

Regulation of Cyclin E by transcription factors of the naïve pluripotency network in mouse embryonic stem cells

Continuous, non-cell cycle-dependent expression of cyclin E is a characteristic feature of mouse embryonic stem cells (ESCs). We studied the 5 regulatory region of Cyclin E, also known as Ccne1, and identified binding sites for transcription factors of the naive pluripotency network, including Esrrb, Klf4, and Tfcp2l1 within 1 kilobase upstream of the transcription start site. Luciferase assay and chromatin immunoprecipitation-quantitative polymerase chain reaction (ChiP-qPCR) study highlighted one binding site for Esrrb that is essential to transcriptional activity of the promoter region, and three binding sites for Klf4 and Tfcp2l1. Knockdown of Esrrb, Klf4, and Tfcp2l1 reduced Cyclin E expression whereas overexpression of Esrrb and Klf4 increased it, indicating a strong correlation between the expression level of these factors and that of cyclin E. We observed that cyclin E overexpression delays differentiation induced by Esrrb depletion, suggesting that cyclin E is an important target of Esrrb for differentiation blockade. We observed that mESCs express a low level of miR-15a and that transfection of a miR-15a mimic decreases Cyclin E mRNA level. These results lead to the conclusion that the high expression level of Cyclin E in mESCs can be attributed to transcriptional activation by Esrrb as well as to the absence of its negative regulator, miR-15a.

cell biology↗