Sall4 Guides p53-Mediated Enhancer Interference upon DNA Damage in Mouse Embryonic Stem Cells.

p53 plays a pivotal role in maintaining the genomic stability of mouse embryonic stem cells (mESCs) through transcriptionally activating and repressing target genes. However, how p53 recognizes its repressed targets remains largely unknown. Herein, we demonstrate that Sall4 negatively regulates DNA damage induced apoptosis (DIA) of mESCs through mediating p53 recruitment to enhancers of ESC-associated genes repressed by p53 from promoters of p53-activated genes. Upon DNA damage, Sall4 is transcriptionally repressed by p53 and plays an anti-apoptotic role without altering p53 activation. Moreover, Sall4 is identified as a novel p53-interacting partner. Consistently, Sall4 exerts its anti-apoptotic function in a p53-dependent manner. Intriguingly, Sall4 depletion not only promotes the transcriptional activation of several p53-regulated pro-apoptotic genes but also compromises p53-mediated repression of ESC master transcription factors in response to DNA damage. Mechanistically, Sall4 balances p53-binding affinity between p53-activated and -repressed genes through tethering p53 to ESC enhancers. In light of our study, Sall4 may contribute to tumorigenesis by antagonizing p53-mediated apoptosis.

Mitochondrial Transfer in the Neurovascular Unit, Not Only for Energy Rescue: A Systematic Review.

Despite substantial evidence highlighting molecular communication within the components of neurovascular units (NVU), the interactions at the organelle level have been insufficiently explored in recent decades. Mitochondria, for instance, beyond their traditional role as energy supply for intracellular metabolism and survival, provide a novel perspective on intercellular connections through mitochondrial transfer. These transferred mitochondria not only carry bioactive molecules but also signal to mitigate risks in both healthy and pathological conditions. In this review, we summarized mitochondrial transfer events, relevant routes, and underlying molecular mechanisms originating from diverse cell populations within NVU. We particularly focus on the therapeutic potential of this mechanism in treating central nervous system disorders, notably neurodegenerative diseases marked by mitochondrial dysfunction and then highlight the promising prospects of exogenous mitochondrial supplementation as a treatment target.