ID2 and HIF-1α collaborate to protect quiescent hematopoietic stem cells from activation, differentiation, and exhaustion
Brad L. Jakubison, … , Kimberly D. Klarmann, Jonathan R. Keller
Brad L. Jakubison, … , Kimberly D. Klarmann, Jonathan R. Keller
Published July 1, 2022
Citation Information: J Clin Invest. 2022;132(13):e152599. https://doi.org/10.1172/JCI152599.
View: Text | PDF
Research Article Hematology

ID2 and HIF-1α collaborate to protect quiescent hematopoietic stem cells from activation, differentiation, and exhaustion

Abstract

Defining mechanism(s) that maintain tissue stem quiescence is important for improving tissue regeneration, cell therapies, aging, and cancer. We report here that genetic ablation of Id2 in adult hematopoietic stem cells (HSCs) promotes increased HSC activation and differentiation, which results in HSC exhaustion and bone marrow failure over time. Id2Δ/Δ HSCs showed increased cycling, ROS production, mitochondrial activation, ATP production, and DNA damage compared with Id2+/+ HSCs, supporting the conclusion that Id2Δ/Δ HSCs are less quiescent. Mechanistically, HIF-1α expression was decreased in Id2Δ/Δ HSCs, and stabilization of HIF-1α in Id2Δ/Δ HSCs restored HSC quiescence and rescued HSC exhaustion. Inhibitor of DNA binding 2 (ID2) promoted HIF-1α expression by binding to the von Hippel-Lindau (VHL) protein and interfering with proteasomal degradation of HIF-1α. HIF-1α promoted Id2 expression and enforced a positive feedback loop between ID2 and HIF-1α to maintain HSC quiescence. Thus, sustained ID2 expression could protect HSCs during stress and improve HSC expansion for gene editing and cell therapies.

Authors

Brad L. Jakubison, Tanmoy Sarkar, Kristbjorn O. Gudmundsson, Shweta Singh, Lei Sun, Holly M. Morris, Kimberly D. Klarmann, Jonathan R. Keller

×

Figure 7

Stabilization of HIF-1α in Id2Δ/Δ HSCs rescues HSC numbers and promotes quiescence in vitro.

Options: View larger image (or click on image) Download as PowerPoint
Stabilization of HIF-1α in Id2Δ/Δ HSCs rescues HSC numbers and promotes ...
(A) Procedure to rescue Id2Δ/Δ loss of function using FG-4592 and DMOG to stabilize HIF-1α expression and NAC to reduce ROS in stem cell expansion assays. (B) Frequency of LSK FLT3– cells in Id2+/+ and Id2Δ/Δ cultures treated with FG-4592, NAC, or DMOG. (C) Total number of LSK FLT3– cells and HSCs following the indicated treatment in stem cell expansion assays. (D) Flow cytometric analysis of HIF-1α expression in Id2+/+ and Id2Δ/Δ HSCs after the indicated treatments. (E) Quantitation of HIF-1α expression (left) and quiescence (right) in HSCs after treatment with FG-4592, NAC, or DMOG. (F and G) Summary of the procedure to rescue HSC function in Id2Δ/Δ HSCs with control, ID2MycFlag, and HIF1α3M lentiviral expression vectors (left). Twenty transduced HSCs were combined with 50,000 LSM BMCs and transplanted into irradiated recipient mice and then analyzed for donor reconstitution after 16 weeks (right). In C and E, data are presented as the mean ± SEM. Comparisons between mean values of 2 groups were evaluated using an unpaired, 1-tailed Student’s t test, and 2-way ANOVA with Dunnett’s correction was used for multiple testing. In F, the center line indicates the median, and the box represents the 25th and 75th percentiles. *P ≤ 0.05, **P ≤ 0.01, and ***P ≤ 0.001.