Loss of Atg2b and Gskip Impairs the Maintenance of the Hematopoietic Stem Cell Pool Size.

Molecular and cellular biology 2022 Jan 20

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A germ line copy number duplication of chromosome 14q32, which contains ATG2B and GSKIP, was identified in families with myeloproliferative neoplasm (MPN). Here, we show that mice lacking both Atg2b and Gskip, but not either alone, exhibited decreased hematopoiesis, resulting in death in utero accompanied by anemia. In marked contrast to MPN patients with duplication of ATG2B and GSKIP, the number of hematopoietic stem cells (HSCs), in particular long-term HSCs, in double-knockout fetal livers was significantly decreased due to increased cell death. Although the remaining HSCs still had the ability to differentiate into hematopoietic progenitor cells, the differentiation efficiency was quite low. Remarkably, mice with knockout of Atg2b or Gskip alone did not show any hematopoietic abnormality. Mechanistically, while loss of both genes had no effect on autophagy, it increased the expression of genes encoding enzymes involved in oxidative phosphorylation. Taken together, our results indicate that Atg2b and Gskip play a synergistic effect in maintaining the pool size of HSCs.

Citation

Shun-Suke Sakai, Atsushi Hasegawa, Ryosuke Ishimura, Naoki Tamura, Shun Kageyama, Satoko Komatsu-Hirota, Manabu Abe, Yiwei Ling, Shujiro Okuda, Manabu Funayama, Mika Kikkawa, Yoshiki Miura, Kenji Sakimura, Ichiei Narita, Satoshi Waguri, Ritsuko Shimizu, Masaaki Komatsu. Loss of Atg2b and Gskip Impairs the Maintenance of the Hematopoietic Stem Cell Pool Size. Molecular and cellular biology. 2022 Jan 20;42(1):e0002421