The MTOR signaling pathway regulates macrophage differentiation from mouse myeloid progenitors by inhibiting autophagy

Autophagy. 2019 Jul;15(7):1150-1162. doi: 10.1080/15548627.2019.1578040. Epub 2019 Feb 27.

Abstract

Understanding of the mechanism for myeloid differentiation provides important insights into the hematopoietic developmental processes. By using an ESC-derived myeloid progenitor cell model, we found that CSF2/GM-CSF triggered macrophage differentiation and activation of the MTOR signaling pathway. Activation or inhibition of the MTOR signaling enhanced or attenuated macrophage differentiation, respectively, suggesting a critical function. We further showed that macroautophagy/autophagy was inhibited with the addition of CSF2. Furthermore, pharmacological inhibition and genetic modification of autophagy enhanced macrophage differentiation and rescued the inhibitory effect on differentiation caused by MTOR inhibition. Thus, the MTOR signaling pathway regulates macrophage differentiation of myeloid progenitors by inhibiting autophagy. Our results provide new insights into the mechanisms for myeloid differentiation and may prove useful for therapeutic applications of hematopoietic and myeloid progenitor cells. Abbreviations: 2-DG: 2-deoxy-D-glucose; ADGRE1/F4/80: adhesion G protein-coupled receptor E1; BM: bone marrow; CQ: chloroquine; ECAR: extracellular acidification rate; ESC: embryonic stem cell; CSF2/GM-CSF: colony stimulating factor 2; CSF3/G-CSF: colony stimulating factor 3; HPC: hematopoietic progenitor cell; ITGAM/CD11b: integrin alpha M; LPS: lipopolysaccharide; MFI: median fluorescence intensity; MTOR: mechanistic target of rapamycin kinase; RPS6KB1/p70S6K1: ribosomal protein S6 kinase, polypeptide 1; shRNA: short hairpin RNA; SQSTM1/p62: sequestosome 1.

Keywords: Autophagy; CSF2; MTOR; myeloid differentiation; myeloid progenitors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Autophagy* / drug effects
  • Autophagy* / genetics
  • Autophagy-Related Protein-1 Homolog / chemistry
  • Autophagy-Related Protein-1 Homolog / genetics
  • Autophagy-Related Protein-1 Homolog / metabolism
  • Autophagy-Related Proteins / genetics
  • Autophagy-Related Proteins / metabolism
  • CD11b Antigen / genetics
  • CD11b Antigen / metabolism
  • Cell Differentiation* / drug effects
  • Cell Differentiation* / genetics
  • Cell Line
  • Granulocyte-Macrophage Colony-Stimulating Factor / pharmacology
  • Macrophages / cytology
  • Macrophages / metabolism*
  • Mice
  • Mice, Inbred C57BL
  • Myeloid Progenitor Cells / cytology
  • Myeloid Progenitor Cells / drug effects
  • Myeloid Progenitor Cells / metabolism*
  • Phosphorylation
  • Sequestosome-1 Protein / genetics
  • Sequestosome-1 Protein / metabolism
  • Signal Transduction* / genetics
  • Sirolimus / pharmacology
  • TOR Serine-Threonine Kinases / antagonists & inhibitors
  • TOR Serine-Threonine Kinases / genetics
  • TOR Serine-Threonine Kinases / metabolism*

Substances

  • Autophagy-Related Proteins
  • CD11b Antigen
  • Sequestosome-1 Protein
  • Granulocyte-Macrophage Colony-Stimulating Factor
  • mTOR protein, mouse
  • Autophagy-Related Protein-1 Homolog
  • TOR Serine-Threonine Kinases
  • Ulk1 protein, mouse
  • Sirolimus

Grants and funding

This work was supported by the National Natural Science Foundation of China (NSFC) [81370600]; The Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning under TP2015022; Shanghai Pujiang Program under Grant 15PJ1404800 and Innovation Program of Shanghai Municipal Education Commission under Grant 15ZZ056.