Haematopoietic stem cells require a highly regulated protein synthesis rate

Area of Science:

• Cellular Physiology
• Stem Cell Biology
• Hematopoiesis

Background:

• Limited understanding of protein synthesis in somatic stem cells.
• Protein synthesis rates are largely uncharacterized in hematopoietic stem cells (HSCs).

Purpose of the Study:

• To compare protein synthesis rates between HSCs and restricted hematopoietic progenitors.
• To investigate the impact of altered protein synthesis on HSC function and leukaemogenesis.

Main Methods:

• In vivo assessment of protein synthesis in HSCs and progenitors.
• Utilized Rpl24(Bst/+) mice with reduced ribosome function.
• Investigated the effects of Pten deletion on HSC protein synthesis and function.

Main Results:

• HSCs exhibit lower protein synthesis rates compared to other hematopoietic cells.
• Reduced ribosome function (Rpl24(Bst/+)) further decreased protein synthesis and impaired HSC function.
• Pten deletion increased protein synthesis in HSCs, leading to reduced function and promoting leukaemogenesis.
• Restoring normal ribosome function rescued Pten deletion-induced defects in HSCs.

Conclusions:

• Protein synthesis levels are critical for HSC function; both extremes (too high or too low) are detrimental.
• Pten deficiency contributes to HSC depletion and leukemia by increasing protein synthesis.
• Modulating protein synthesis represents a potential therapeutic strategy for HSC disorders and leukemia.