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Summary: Cell identity is orchestrated through an interplay between transcription factor (TF) action and genome architecture. The mechanisms used by TFs to shape three-dimensional (3D) genome organization remain incompletely understood. Here we present evidence that the lineage-instructive TF CEBPA drives extensive chromatin compartment switching and promotes the formation of long-range chromatin hubs during induced B cell-to-macrophage transdifferentiation. Mechanistically, we find that the intrinsically disordered region (IDR) of CEBPA undergoes in vitro phase separation (PS) dependent on aromatic residues. Both overexpressing B cells and native CEBPA-expressing cell types such as primary granulocyte-macrophage progenitors, liver cells, and trophectoderm cells reveal nuclear CEBPA foci and long-range 3D chromatin hubs at CEBPA-bound regions. In short, we show that CEBPA can undergo PS through its IDR, which may underlie in vivo foci formation and suggest a potential role of PS in regulating CEBPA function.

Promyelocytic leukemia protein (PML), the main constituent of PML nuclear bodies, regulates various physiological processes in different cell types. However, little is known about its functions in embryonic stem cells (ESC). Here, we report that PML contributes to ESC self-renewal maintenance by controlling cell-cycle progression and sustaining the expression of crucial pluripotency factors. Transcriptomic analysis and gain- or loss-of-function approaches showed that PML-deficient ESC exhibit morphological, metabolic, and growth properties distinct to naive and closer to the primed pluripotent state. During differentiation of embryoid bodies, PML influences cell-fate decisions between mesoderm and endoderm by controlling the expression of Tbx3. PML loss compromises the reprogramming ability of embryonic fibroblasts to induced pluripotent stem cells by inhibiting the transforming growth factor β pathway at the very early stages. Collectively, these results designate PML as a member of the regulatory network for ESC naive pluripotency and somatic cell reprogramming.

Objectives: The peak of the COVID-19 pandemic was a challenging situation for transfusion-dependent thalassemia (TDT) patients. The objectives of this study were to measure the quality of life (QoL) in TDT patients during the COVID-19 lockdown restriction measures, compare the results with the pre-COVID-19 era, and evaluate the influence of sociodemographic and clinical factors on QoL., Methods: This was a cross-sectional study of 110 consecutively selected adult TDT patients, during the stringent lockdown restriction measures implemented in Greece. All participants completed a combination of 2 QoL questionnaires, the generic Short-Form Health Survey 36 version 2 and the disease-specific Transfusion-Quality of life (TranQol). We used the "1/2 SD method," a distribution-based approach to calculate minimal clinically important differences and clinically compare the QoL scores between the pre-COVID-19 and post-COVID-19 era. A backward stepwise linear regression was selected to explore the influence of potential predictors on TranQol scores., Results: The Short-Form Health Survey 36 version 2 and TranQol scores remained low but not clinically different compared with the pre-COVID-19 era. Older, married, and higher educated TDT patients exhibited significantly lower TranQol summary scores. The patients who reported a negative effect of the COVID-19 pandemic had significantly lower TranQol scores in summary and all subdomains except for school and career., Conclusions: During the COVID-19 pandemic, the overall QoL of TDT patients was clinically similar to the status of the pre-COVID-19 era. Nevertheless, most of the significant QoL subdomains were negatively affected, and distinct groups of TDT patients were more vulnerable., Competing Interests: Author Disclosures Author disclosure forms can be accessed below in the Supplemental Material section., (Copyright © 2024 International Society for Health Economics and Outcomes Research. Published by Elsevier Inc. All rights reserved.)