Beclin 1 of megakaryocytic lineage cells is locally dispensable for platelet hemostasis but functions distally in bone homeostasis
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE283093 | GEO | 2025/03/12
REPOSITORIES: GEO
Similar Datasets
Project description:The crosstalk between megakaryocytic lineage cells and the skeletal system has just begun to be explored but remains largely elusive. Using conditional gene knockout mouse models, we demonstrated that loss of Beclin 1 (Becn1), a major regulator of mammalian autophagy, exclusively in the megakaryocytic lineage disrupted autophagy in platelets but did not compromise megakaryopoiesis or the formation and function of platelets. Unexpectedly, conditional Becn1 deletion in male mice led to a remarkable increase in bone mass with improved bone quality, in association with a decrease in sex hormone binding globulin (SHBG) and an increase in free testosterone (FT). In vivo Becn1 overexpression in megakaryocytic lineage-specific cells reduced bone mass and quality, along with an increase in SHBG and a decrease in FT. Transplantation of wild-type bone marrow cells into megakaryocytic lineage Becn1-deficient male mice restored bone mass and normalized SHBG and FT. Furthermore, bilateral orchiectomy of Becn1f/f;Pf4-iCre mice, which are crippled with the production of testosterone, resulted in a reduction in bone mass and quality, whereas in vivo overexpression of SHBG, specifically in the liver of Becn1f/f;Pf4-iCre mice, decreased FT and reduced bone mass and quality. In addition, metformin treatment, which induces SHBG expression, reduced FT and normalized bone mass in Becn1f/f;Pf4-iCre mice. We thus concluded that Becn1 of the megakaryocytic lineage is dispensable locally for platelet hemostasis but limits bone mass by increasing SHBG, which in turn reduces the FT of male mice. Our findings highlight a mechanism by which Becn1 from megakaryocytic lineage cells distally balances bone growth.
| S-EPMC11876339 | biostudies-literature
Project description:Beclin 1 of megakaryocytic lineage cells is locally dispensable for platelet hemostasis but functions distally in bone homeostasis
| PRJNA1191849 | ENA
Project description:Proper control of inflammatory responses is essential for embryonic development, but the underlying mechanism is poorly understood. Here, we show that under physiological conditions, inactivation of ISG15, an inflammation amplifier, is associated with the interaction of Beclin 1 (Becn1), via its ECD domain, with STAT3 in the major fetal hematopoietic organ of mice. Conditional loss of Becn1 caused sequential dysfunction and exhaustion of fetal liver hematopoietic stem cells, leading to lethal inflammatory cell-biased hematopoiesis in the fetus. Molecularly, the absence of Becn1 resulted in the release of STAT3 from Becn1 tethering and subsequent phosphorylation and translocation to the nucleus, which in turn directly activated the transcription of ISG15 in fetal liver hematopoietic cells, coupled with increased ISGylation and production of inflammatory cytokines, whereas inactivating STAT3 reduced ISG15 transcription and inflammation but improved hematopoiesis potential, and further silencing ISG15 mitigated the above collapse in the Becn1 null hematopoietic lineage. The Becn1-STAT3-ISG15 axis remains functional in Atg5/7-disrupted fetal hematopoietic organs. These results suggest that Becn1, in an autophagy-independent manner, secures hematopoiesis and survival of the fetus by directly inhibiting STAT3-ISG15 activation to prevent cytokine storms. Our findings highlight a previously undocumented role of Becn1 in governing ISG15 to safeguard the fetus.
2025-02-05 | GSE280034 | GEO
Project description:A high incidence of acute megakaryoblastic leukemia (AMKL) in Down syndrome patients implies that chromosome 21 genes have a pivotal role in AMKL development, but the functional contribution of individual genes remains elusive. Here, we report that SON, a chromosome 21-encoded DNA- and RNA-binding protein, inhibits megakaryocytic differentiation by suppressing RUNX1 and the megakaryocytic gene expression program. As megakaryocytic progenitors differentiate, SON expression is drastically reduced, with mature megakaryocytes having the lowest levels. In contrast, AMKL cells express an aberrantly high level of SON, and knockdown of SON induced the onset of megakaryocytic differentiation in AMKL cell lines. Genome-wide transcriptome analyses revealed that SON knockdown turns on the expression of pro-megakaryocytic genes while reducing erythroid gene expression. Mechanistically, SON represses RUNX1 expression by directly binding to the proximal promoter and two enhancer regions, the known +23 kb enhancer and the novel +139 kb enhancer, at the RUNX1 locus to suppress H3K4 methylation. In addition, SON represses the expression of the AP-1 complex subunits JUN, JUNB and FOSB which are required for late megakaryocytic gene expression. Our findings define SON as a negative regulator of RUNX1 and megakaryocytic differentiation, implicating SON overexpression in impaired differentiation during AMKL development.
2020-09-01 | GSE157178 | GEO
Project description:The mechanism underlying thrombocytosis in patients with iron deficiency anemia remains unknown. We present findings that support the hypothesis that low iron biases the commitment of Megakaryocytic-Erythroid Progenitors (MEP) toward the megakaryocytic (Mk) lineage in mice. In MEP of Transmembrane serine protease 6 knockout (Tmprss6-/-) mice, which exhibit iron deficiency microcytic anemia concomitant with thrombocytosis, we observed a megakaryocytic (Mk) bias, decreased labile iron, and decreased proliferation relative to wild-type (WT) MEP. Bone marrow transplantation assays suggest that the systemic iron deficiency of the Tmprss6-/- recipients contributes to the MEP lineage commitment bias. Genes involved in metabolic, VEGF, and ERK pathways were enriched among those differentially expressed between WT and Tmprss6-/- MEP. Corroborating our findings from the murine model of chronic iron deficiency anemia, primary human MEP also exhibited decreased proliferation and Mk-biased commitment when their iron sensing pathways were disrupted by knockdown of Transferrin Receptor 2. These data are consistent with a model in which low iron in the marrow environment affects MEP metabolism, attenuates ERK signaling, slows proliferation, and biases MEP toward Mk lineage commitment. Keywords: megakaryocytic-erythroid progenitor (MEP), iron deficiency, Tmprss6
2023-03-17 | GSE227563 | GEO
Project description:Single-cell RNA sequencing was performed on bone marrow mononuclear of a patient with acute myeloid leukemia with erythroid differentiation of the blasts and on peripheral blood mononuclear cells of a patient with acute myeloid leukemia with megakaryocytic differentiation of the blasts. Raw data for this dataset can be found at the EGA under accession EGAS00001006819.
2022-12-05 | E-MTAB-12607 | biostudies-arrayexpress
Project description:SON inhibits megakaryocytic differentiation via repressing the megakaryocytic gene expression program in acute megakaryoblastic leukemia
| PRJNA660403 | ENA
Project description:Rostro-caudal coordination of spinal motor output is essential for locomotion. Most spinal interneurons project axons longitudinally to govern locomotor output, yet their connectivity along this axis remains unclear. In this study, we use larval zebrafish to map synaptic outputs of a major inhibitory population, V1 (Eng1+) neurons, which are implicated in dual sensory and motor functions. We find that V1 neurons exhibit long axons extending rostrally and exclusively ipsilaterally for an average of 6 spinal segments; however, they do not connect uniformly with their post-synaptic targets along the entire length of their axon. Locally, V1 neurons inhibit motor neurons (both fast and slow) and other premotor targets, including V2a, V2b, and commissural premotor neurons. In contrast, V1 neurons make robust long-range inhibitory contacts onto a dorsal horn sensory population, the commissural primary ascending neurons (CoPAs). In a computational model of the ipsilateral spinal network, we show that this pattern of short-range V1 inhibition to motor and premotor neurons underlies burst termination, which is critical for coordinated rostro-caudal propagation of the locomotor wave. We conclude that spinal network architecture in the longitudinal axis can vary dramatically, with differentially targeted local and distal connections, yielding important consequences for function.
| S-EPMC8440420 | biostudies-literature
Project description:Profiling of human megakaryocytic cell lines using genome wide gene expression microarrays
2011-11-04 | E-MTAB-908 | biostudies-arrayexpress
Project description:The Core Binding Factor (CBF) protein RUNX1 is a master regulator of definitive hematopoiesis, crucial for hematopoietic stem cell (HSC) emergence during ontogeny, which also plays vital roles in adult mice, in regulating the correct specification of numerous blood lineages. Akin to the other mammalian Runx genes, Runx1 has two promoters P1 (distal) and P2 (proximal) which generate distinct protein isoforms. The activities and specific relevance of these two promoters in adult hematopoiesis remain to be fully elucidated. Utilizing a dual reporter model we demonstrate here that the distal P1 promoter is broadly active in adult hematopoietic stem and progenitor cell (HSPC) populations. By contrast the activity of the proximal P2 promoter is more restricted and its upregulation, in both the immature Lineage- Sca1high cKithigh (LSK) and bipotential Pre-Megakaryocytic/Erythroid Progenitor (PreMegE) populations, coincides with a loss of erythroid specification. Accordingly the PreMegE population can be prospectively separated into âpro-erythroidâ and âpro-megakaryocyteâ populations based on Runx1 P2 activity. Comparative gene expression analyses between Runx1 P2+ and P2- populations indicated that the level of CD34 expression could substitute for P2 activity to distinguish these two cell populations in wild type (WT) bone marrow (BM). Prospective isolation of these two populations will provide the opportunity to further investigate and define the molecular mechanisms involved in megakaryocytic/erythroid (Mk/Ery) cell fate decisions. mRNA profiles of wild type (WT), Runx1 P2-hCD4+ (P2+) and Runx1 P2-hCD4- (P2-) Bone marrow Pre-Megakryocyte/Erythroid (PreMegE) progenitors were generated from young adult (12-16 weeks) mice by deep sequencing, in triplicate, using Illumina NextSeq 500.
2016-01-04 | E-GEOD-68958 | biostudies-arrayexpress