BRPF1 is essential for development of fetal hematopoietic stem cells
Linya You, … , Edwin Wang, Xiang-Jiao Yang
Linya You, … , Edwin Wang, Xiang-Jiao Yang
Published August 8, 2016
Citation Information: J Clin Invest. 2016;126(9):3247-3262. https://doi.org/10.1172/JCI80711.
View: Text | PDF
Research Article Article has an altmetric score of 5

BRPF1 is essential for development of fetal hematopoietic stem cells

Abstract

Hematopoietic stem cells (HSCs) serve as a life-long reservoir for all blood cell types and are clinically useful for a variety of HSC transplantation-based therapies. Understanding the role of chromatin organization and regulation in HSC homeostasis may provide important insights into HSC development. Bromodomain- and PHD finger–containing protein 1 (BRPF1) is a multivalent chromatin regulator that possesses 4 nucleosome-binding domains and activates 3 lysine acetyltransferases (KAT6A, KAT6B, and KAT7), suggesting that this protein has the potential to stimulate crosstalk between different chromatin modifications. Here, we investigated the function of BRPF1 in hematopoiesis by selectively deleting its gene in murine blood cells. Brpf1-deficient pups experienced early lethality due to acute bone marrow failure and aplastic anemia. The mutant bone marrow and fetal liver exhibited severe deficiency in HSCs and hematopoietic progenitors, along with elevated reactive oxygen species, senescence, and apoptosis. BRPF1 deficiency also reduced the expression of multipotency genes, including Slamf1, Mecom, Hoxa9, Hlf, Gfi1, Egr, and Gata3. Furthermore, BRPF1 was required for acetylation of histone H3 at lysine 23, a highly abundant but not well-characterized epigenetic mark. These results identify an essential role of the multivalent chromatin regulator BRPF1 in definitive hematopoiesis and illuminate a potentially new avenue for studying epigenetic networks that govern HSC ontogeny.

Authors

Linya You, Lin Li, Jinfeng Zou, Kezhi Yan, Jad Belle, Anastasia Nijnik, Edwin Wang, Xiang-Jiao Yang

×

Figure 4

Brpf1 disruption impairs colony formation and bone marrow reconstitution activities in the neonatal bone marrow.

Options: View larger image (or click on image) Download as PowerPoint
Brpf1 disruption impairs colony formation and bone marrow reconstitutio...
(A) Myeloid progenitor cell colony formation. Bone marrow cells (6 × 104) isolated from control and Brpf1fl/fl Vav1-iCre (vKO) pups at P6 were plated and cultured in MethoCult M3434 and colonies were analyzed on days 8–10. Representative images of the plates are shown. (B) Myeloid progenitor cell colony formation assays were performed as in A. Three different types of colonies, burst-forming unit-erythroid (BFU-E), colony-forming unit-granulocyte/monocyte (CFU-GM), and colony-forming unit-granulocyte/erythrocyte/monocyte/megakaryocyte (CFU-GEMM), were enumerated on days 8–10. Average values were calculated from 3 pairs of control and vKO pups. (C) B cell progenitor colony formation. Bone marrow cells (1.5 × 105) from control and vKO pups at P6 were cultured in MethoCult M3630 (see Supplemental Methods) and pre-B cell colonies were counted on days 8–10. Average values from 3 pairs of control and vKO pups are shown. (D) Long-term hematopoietic reconstitution was impaired in the mutant bone marrow. Contribution of donor (CD45.2+) cells in the recipients’ peripheral blood was determined at 4 to 16 weeks after transplantation. (E) At week 16 after transplantation, multilineage engraftment in the peripheral blood was analyzed. Note the robust contribution of the control but not the mutant CD45.2+ bone marrow cells to formation of B cells (B220+), myeloid cells (Gr1+Mac1+), and T cells (CD4+ or CD8+). (F) Fractions of donor-derived cells in HSCs, progenitors, and lineage cells in the recipient bone marrow at week 16 after transplantation. For D–F, n = 6 for each group; ***P < 0.001. Unpaired 2-tailed Student’s t tests were performed and average values are shown as the mean + SEM in B–F. LT-HSC, long-term HSC; ST-HSC, short-term HSC.