Elevated Hedgehog activity contributes to attenuated DNA damage responses in aged hematopoietic cells

• Published in: Leukemia 2020-04, Vol.34 (4), p.1125-1134
• Main Authors: Scheffold, Annika, Baig, Ali H., Chen, Zhiyang, von Löhneysen, Sarah E., Becker, Friedrich, Morita, Yohei, Avila, Alush I., Groth, Marco, Lechel, André, Schmid, Florian, Kraus, Johann M., Kestler, Hans A., Stilgenbauer, Stephan, Philipp, Melanie, Burkhalter, Martin D.
• Format: Article
• Language: English
• Subjects: 13/89; 38/1; 38/39; 38/61; 45/15; 631/532/1542; 631/80/86; 64/60; 96/1; 96/31; 96/63; Aging; Aldehydes; Animals; Antimitotic agents; Antineoplastic agents; Apoptosis; Cancer Research; Cell Differentiation; Cell Proliferation; Cells (biology); Cells, Cultured; Critical Care Medicine; Damage accumulation; Damage prevention; Damage tolerance; Deoxyribonucleic acid; Differentiation; DNA; DNA Damage; Female; Genetic aspects; Health aspects; Hedgehog protein; Hedgehog proteins; Hedgehog Proteins - metabolism; Hematology; Hematopoiesis; Hematopoietic stem cells; Hematopoietic Stem Cells - drug effects; Hematopoietic Stem Cells - metabolism; Hematopoietic Stem Cells - pathology; Hematopoietic system; Humans; Intensive; Internal Medicine; Medicine; Medicine & Public Health; Mice; Mice, Inbred C57BL; Oncology; Patient outcomes; Phenotypes; Progenitor cells; Protein biosynthesis; Toxins; Veratrum Alkaloids - pharmacology
• ISSN: 0887-6924; 1476-5551
• DOI: 10.1038/s41375-019-0641-3

Accumulation of DNA damage and myeloid-skewed differentiation characterize aging of the hematopoietic system, yet underlying mechanisms remain incompletely understood. Here, we show that aging hematopoietic progenitor cells particularly of the myeloid branch exhibit enhanced resistance to bulky DNA lesions—a relevant type of DNA damage induced by toxins such as cancer drugs or endogenous aldehydes. We identified aging-associated activation of the Hedgehog (Hh) pathway to be connected to this phenotype. Inhibition of Hh signaling reverts DNA damage tolerance and DNA damage-resistant proliferation in aged hematopoietic progenitors. Vice versa, elevating Hh activity in young hematopoietic progenitors is sufficient to impair DNA damage responses. Altogether, these findings provide experimental evidence for aging-associated increases in Hh activity driving DNA damage tolerance in myeloid progenitors and myeloid-skewed differentiation. Modulation of Hh activity could thus be explored as a therapeutic strategy to prevent DNA damage tolerance, myeloid skewing, and disease development in the aging hematopoietic system.