ISWI chromatin remodeling ATPase SMARCA5 (SNF2H) is a well-known factor for its role in regulation of DNA access via nucleosome sliding and assembly. SMARCA5 transcriptionally inhibits the myeloid master regulator PU.1. Upregulation of SMARCA5 was previously observed in CD34+ hematopoietic progenitors of acute myeloid leukemia (AML) patients. Since high levels of SMARCA5 are necessary for intensive cell proliferation and cell cycle progression of developing hematopoietic stem and progenitor cells in mice, we reasoned that removal of SMARCA5 enzymatic activity could affect the cycling or undifferentiated state of leukemic progenitor-like clones. Indeed, we observed that CRISPR/cas9-mediated SMARCA5 knockout in AML cell lines (S5KO) inhibited the cell cycle progression. We also observed that the SMARCA5 deletion induced karyorrhexis and nuclear budding as well as increased the ploidy, indicating its role in mitotic division of AML cells. The cytogenetic analysis of S5KO cells revealed the premature chromatid separation. We conclude that deleting SMARCA5 in AML blocks leukemic proliferation and chromatid cohesion.
- MeSH
- adenosintrifosfatasy nedostatek metabolismus MeSH
- akutní myeloidní leukemie * enzymologie genetika patologie MeSH
- buňky K562 MeSH
- chromatidy * genetika metabolismus MeSH
- chromozomální proteiny, nehistonové nedostatek metabolismus MeSH
- genový knockout * MeSH
- lidé MeSH
- nádorové buněčné linie MeSH
- nádorové proteiny * nedostatek metabolismus MeSH
- proliferace buněk * MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Development of lymphoid progenitors requires a coordinated regulation of gene expression, DNA replication, and gene rearrangement. Chromatin-remodeling activities directed by SWI/SNF2 superfamily complexes play important roles in these processes. In this study, we used a conditional knockout mouse model to investigate the role of Smarca5, a member of the ISWI subfamily of such complexes, in early lymphocyte development. Smarca5 deficiency results in a developmental block at the DN3 stage of αβ thymocytes and pro-B stage of early B cells at which the rearrangement of Ag receptor loci occurs. It also disturbs the development of committed (CD73+) γδ thymocytes. The αβ thymocyte block is accompanied by massive apoptotic depletion of β-selected double-negative DN3 cells and premitotic arrest of CD4/CD8 double-positive cells. Although Smarca5-deficient αβ T cell precursors that survived apoptosis were able to undergo a successful TCRβ rearrangement, they exhibited a highly abnormal mRNA profile, including the persistent expression of CD44 and CD25 markers characteristic of immature cells. We also observed that the p53 pathway became activated in these cells and that a deficiency of p53 partially rescued the defect in thymus cellularity (in contrast to early B cells) of Smarca5-deficient mice. However, the activation of p53 was not primarily responsible for the thymocyte developmental defects observed in the Smarca5 mutants. Our results indicate that Smarca5 plays a key role in the development of thymocytes undergoing β-selection, γδ thymocytes, and also B cell progenitors by regulating the transcription of early differentiation programs.
- MeSH
- adenosintrifosfatasy genetika metabolismus MeSH
- B-lymfocyty fyziologie MeSH
- buněčná diferenciace MeSH
- chromozomální proteiny, nehistonové genetika metabolismus MeSH
- genová přestavba MeSH
- klonální selekce zprostředkovaná antigeny MeSH
- kultivované buňky MeSH
- lymfoidní progenitorové buňky fyziologie MeSH
- myši inbrední C57BL MeSH
- myši knockoutované MeSH
- myši MeSH
- nádorový supresorový protein p53 metabolismus MeSH
- receptory antigenů B-buněk genetika metabolismus MeSH
- receptory antigenů T-buněk alfa-beta genetika metabolismus MeSH
- receptory antigenů T-buněk gama-delta genetika metabolismus MeSH
- T-lymfocyty fyziologie MeSH
- thymocyty fyziologie MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
- Publikační typ
- abstrakt z konference MeSH
