bims-iorami Biomed News
on Ionising Radiation and Mitochondria
Issue of 2024–03–31
three papers selected by
Chenxiao Yu, Soochow University



  1. Cytokine Growth Factor Rev. 2024 Mar 26. pii: S1359-6101(24)00030-3. [Epub ahead of print]
      Innate immunity is not only the first line of host defense against microbial infections but is also crucial for the host responses against a variety of noxious stimuli. Z-DNA binding protein 1 (ZBP1) is a cytosolic nucleic acid sensor that can induce inflammatory cell death in both immune and nonimmune cells upon sensing of incursive virus-derived Z-form nucleic acids and self-nucleic acids via its Zα domain. Mechanistically, aberrantly expressed or activated ZBP1 induced by pathogens or noxious stimuli enables recruitment of TANK binding kinase 1 (TBK1), interferon regulatory factor 3 (IRF3), receptor-interacting serine/threonine-protein kinase 1 (RIPK1) and RIPK3 to drive type I interferon (IFN-I) responses and activation of nuclear factor kappa B (NF-κB) signaling. Meanwhile, ZBP1 promotes the assembly of ZBP1- and absent in melanoma 2 (AIM2)-PANoptosome, which ultimately triggers PANoptosis through caspase 3-mediated apoptosis, mixed lineage kinase domain like pseudokinase (MLKL)-mediated necroptosis, and gasdermin D (GSDMD)-mediated pyroptosis. In response to damaged mitochondrial DNA, ZBP1 can interact with cyclic GMP-AMP synthase to augment IFN-I responses but inhibits toll like receptor 9-mediated inflammatory responses. This review summarizes the structure and expression pattern of ZBP1, discusses its roles in human diseases through immune-dependent (e.g., the production of IFN-I and pro-inflammatory cytokines) and -independent (e.g., the activation of cell death) functions, and highlights the attractive prospect of manipulating ZBP1 as a promising therapeutic target in diseases.
    Keywords:  Disease; Innate immunity; PANoptosis; Z-DNA binding protein 1
    DOI:  https://doi.org/10.1016/j.cytogfr.2024.03.005
  2. Int J Mol Sci. 2024 Mar 15. pii: 3320. [Epub ahead of print]25(6):
      An important hallmark of radiation dermatitis is the impairment of the mitotic ability of the stem/progenitor cells in the basal cell layers due to radiation-induced DNA damage, leading to suppressed cell renewal in the epidermis. However, this mechanism alone does not adequately explain the complex pathogenesis of radiation-induced skin injury. In this review, we summarize the latest findings on the complex pathogenesis of radiation dermatitis and correlate these with the clinical features of radiation-induced skin reactions. The current studies show that skin exposure to ionizing radiation induces cellular senescence in the epidermal keratinocytes. As part of their epithelial stress response, these senescent keratinocytes secrete pro-inflammatory mediators, thereby triggering skin inflammation. Keratinocyte-derived cytokines and chemokines modulate intercellular communication with the immune cells, activating skin-resident and recruiting skin-infiltrating immune cells within the epidermis and dermis, thereby orchestrating the inflammatory response to radiation-induced tissue damage. The increased expression of specific chemoattractant chemokines leads to increased recruitment of neutrophils into the irradiated skin, where they release cytotoxic granules that are responsible for the exacerbation of an inflammatory state. Moreover, the importance of IL-17-expressing γδ-T cells to the radiation-induced hyperproliferation of keratinocytes was demonstrated, leading to reactive hyperplasia of the epidermis. Radiation-induced, reactive hyperproliferation of the keratinocytes disturbs the fine-tuned keratinization and cornification processes, leading to structural dysfunction of the epidermal barrier. In summary, in response to ionizing radiation, epidermal keratinocytes have important structural and immunoregulatory barrier functions in the skin, coordinating interacting immune responses to eliminate radiation-induced damage and to initiate the healing process.
    Keywords:  cellular senescence; epidermis; ionizing radiation; radiation dermatitis; senescence-associated secretory phenotype (SASP); skin inflammation
    DOI:  https://doi.org/10.3390/ijms25063320
  3. Cancers (Basel). 2024 Mar 13. pii: 1141. [Epub ahead of print]16(6):
      On the one hand, ionizing radiation has been used to treat not only cancer, but also non-cancer diseases. On the other hand, associations with radiation exposure have increasingly been reported not only for cancer, but also non-cancer diseases, both at doses or dose rates much lower than previously suggested or considered. This underscores the need for considering both cancer and non-cancer effects of medical (diagnostic or therapeutic), occupational or environmental exposure to radiation. As such, this Special Issue aims to serve as a forum to gather the latest developments and discuss future prospects in the field of normal tissue responses to radiation exposure. The Special Issue is composed of 18 articles outlining the radiation effects arising in various tissues (e.g., those in the circulatory, sensory, nervous, respiratory, and reproductive systems).
    DOI:  https://doi.org/10.3390/cancers16061141