bims-minfam Biomed News
on Inflammation and metabolism in ageing and cancer
Issue of 2025–09–14
eight papers selected by
Ayesh Seneviratne, McMaster University



  1. Blood. 2025 Sep 08. pii: blood.2024027432. [Epub ahead of print]
      Hematopoietic stem cells (HSCs) responsible for blood cell production and their bone marrow regulatory niches undergo age-related changes, impacting immune responses and predisposing individuals to hematologic malignancies. Here, we show that the age-related alterations of the megakaryocytic niche and associated downregulation of Platelet Factor 4 (PF4) are pivotal mechanisms driving HSC aging. PF4-deficient mice display several phenotypes reminiscent of accelerated HSC aging, including lymphopenia, increased myeloid output, and DNA damage, mimicking physiologically aged HSCs. Remarkably, recombinant PF4 administration restored old HSCs to youthful functional phenotypes characterized by improved cell polarity, reduced DNA damage, enhanced in vivo reconstitution capacity, and balanced lineage output. Mechanistically, we identified LDLR and CXCR3 as the HSC receptors transmitting the PF4 signal, with double knockout mice showing exacerbated HSC aging phenotypes similar to PF4-deficient mice. Furthermore, human HSCs across various age groups also respond to the youthful PF4 signaling, highlighting its potential for rejuvenating aged hematopoietic systems. These findings pave the way for targeted therapies aimed at reversing age-related HSC decline with potential implications in the prevention or improvement of the course of age-related hematopoietic diseases.
    DOI:  https://doi.org/10.1182/blood.2024027432
  2. Annu Rev Pathol. 2025 Sep 10.
      Clonal hematopoiesis, originally identified as a precursor to hematologic malignancies, has emerged as a significant factor in various nonmalignant diseases. Recent research highlights how somatic mutations in hematopoietic stem cells lead to the expansion of circulating mutated immune cells that exert profound effects on organ function and disease progression. These mutated clones display altered inflammatory profiles and tissue-specific functional consequences, contributing to various diseases including atherosclerotic cardiovascular disease, osteoporosis, heart failure, and neurodegenerative conditions. Key mutations, particularly in genes regulating epigenetics (TET2, DNMT3A, ASXL1), splicing (SF3B1, U2AF1), and DNA damage repair (TP53, PPM1D), modify immune responses and promote chronic inflammation. Intriguingly, while clonal hematopoiesis exacerbates many inflammatory conditions, it has been linked to a protective effect in Alzheimer's disease, potentially due to enhanced microglial function. Understanding the mechanistic underpinnings of clonal hematopoiesis in nonmalignant disease may inform targeted therapeutic strategies, particularly those aimed at modulating inflammation. This review explores the gene- and organ-specific roles of clonal hematopoiesis, highlighting its implications for disease pathogenesis and potential interventions.
    DOI:  https://doi.org/10.1146/annurev-pathmechdis-111523-023442