Biology subjects

Hyden-Granskog, C.

Publications and source records attributed to Hyden-Granskog, C..

3 recordsLinked to original sources

bioRxiv2026

Hsa-miR-92a-3p regulates cell-cycle and signaling programs during human extra-embryonic lineage commitment

MicroRNA (miRNA) levels increase during human embryonic genome activation (EGA) and have been implicated in the first lineage decisions. Re-analyzing single-cell and bulk small RNA-seq (sRNA-seq) from human and mouse embryos, together with new sRNA-seq of naive human embryonic stem cells (hESCs) differentiated into hypoblast-like cells (HLCs) and extra-embryonic mesoderm (EXM)-like cells (EXMCs), we identify hsa-miR-92a-3p as highly expressed from oocyte to morula stage and dynamically regulated during HLC and EXMC formation. Functional inhibition of hsa-miR-92a-3p delays RACL (HLC/EXMC) differentiation, maintains epiblast-like and promotes trophectoderm (TE)-like transcriptional features, and reduces hypoblast and EXM marker acquisition. Transcriptome analyses revealed derepression of hsa-miR-92a-3p targets, including FGF2, and shifts in developmental and cell-cycle programs. The patterns of FGF protein stainings and flow cytometry-based cell-cycle analysis further implicate these pathways in RACL differentiation. Our findings position hsa-miR-92a-3p as a central regulator coordinating signaling and cell-cycle cues during extra embryonic lineage progression.

developmental biology↗

bioRxiv2024

Mechano-osmotic signals control chromatin state and fate transitions in pluripotent stem cells

Acquisition of specific cell shapes and morphologies is a central component of cell fate transitions. Although signaling circuits and gene regulatory networks that regulate pluripotent stem cell differentiation have been intensely studied, how these networks are integrated in space and time with morphological transitions and mechanical deformations to control state transitions remains a fundamental open question. Here, we focus on two distinct models of pluripotency, primed pluripotent stem cells and pre-implantation inner cell mass cells of human embryos to discover that cell fate transitions associate with rapid changes in nuclear shape and volume which collectively alter the nuclear mechanophenotype. Mechanistic studies in human induced pluripotent stem cells further reveal that these phenotypical changes and the associated active fluctuations of the nuclear envelope arise from growth factor signaling-controlled changes in chromatin mechanics and cytoskeletal confinement. These collective mechano-osmotic changes trigger global transcriptional repression and a condensation-prone environment that primes chromatin for a cell fate transition by attenuating repression of differentiation genes. However, while this mechano-osmotic chromatin priming has the potential to accelerate fate transitions and differentiation, sustained biochemical signals are required for robust induction of specific lineages. Our findings uncover a critical mechanochemical feedback mechanism that integrates nuclear mechanics, shape and volume with biochemical signaling and chromatin state to control cell fate transition dynamics.

cell biology↗

bioRxiv2019

DUX4 regulates oocyte to embryo transition in human

During the human oocyte-to-embryo transition, the fertilized oocyte undergoes final maturation and the embryo genome is gradually activated during the first three cell divisions. How this transition is coordinated in humans is largely unknown. We show that the double homeodomain transcription factor DUX4 contributes to this transition. DUX4 knockdown in human zygotes caused insufficient transcriptome reprogramming as observed three days after fertilization. Induced DUX4 expression in human embryonic stem cells activated transcription of thousands of newly identified bi-directional transcripts, including putative enhancers for embryonic genome activation genes such as LEUTX. DUX4 protein interacted with transcriptional modifiers that are known to couple enhancers and promoters. Taken together, our results reveal that DUX4 is a pioneer regulating oocyte-to-embryo transition in human through activation of intergenic genome, especially enhancers, and hence setting the stage for early human embryo development.

developmental biology↗