scholarly journals Expansion of senescent megakaryocyte-lineage cells maintains CML cell leukemogenesis

2020 ◽  
Vol 4 (24) ◽  
pp. 6175-6188
Author(s):  
Yamato Tanabe ◽  
Shimpei Kawamoto ◽  
Tomoiku Takaku ◽  
Soji Morishita ◽  
Atsushi Hirao ◽  
...  

Abstract BCR-ABL, an oncogenic fusion gene, plays a central role in the pathogenesis of chronic myeloid leukemia (CML). Oncogenic signaling induces oncogene-induced senescence and senescence-associated secretory phenotype (SASP), which is characterized by enhanced production of various cytokines. BCR-ABL gene transduction confers senescent phenotype in vitro; however, the in vivo relevance of senescence has not been explored in this context. Transplantation of BCR-ABL–expressing hematopoietic stem/progenitor cells caused CML in mice with an increase in bone marrow BCR-ABL+CD41+CD150+ leukemic megakaryocyte-lineage (MgkL) cells, which exhibited enhanced senescence-associated β-galactosidase staining and increased expression of p16 and p21, key molecules that are crucially involved in senescence. Moreover, knockout of p16 and p21 genes reduced both BCR-ABL–induced abnormal megakaryopoiesis and the maintenance of CML cell leukemogenic capacity, as evidenced by attenuated leukemogenic capacity at secondary transplantation. The expression of transforming growth factor-β1 (TGF-β1), a representative SASP molecule, was enhanced in the leukemic MgkL cells, and TGF-β1 inhibition attenuated CML cell leukemogenic capacity both in vitro and in vivo. Furthermore, BCR-ABL–expressing MgkL cells displayed enhanced autophagic activity, and autophagy inhibition reduced bone marrow MgkL cell number and prolonged the survival of CML mice, which had transiently received the tyrosine kinase inhibitor, imatinib, earlier. Thus, BCR-ABL induced the expansion of senescent leukemic MgkL cells, which supported CML leukemogenesis by providing TGF-β1.

2021 ◽  
Vol 22 (4) ◽  
pp. 1985
Author(s):  
Xiaohe Li ◽  
Ling Ma ◽  
Kai Huang ◽  
Yuli Wei ◽  
Shida Long ◽  
...  

Idiopathic pulmonary fibrosis (IPF) is a fatal and age-related pulmonary disease. Nintedanib is a receptor tyrosine kinase inhibitor, and one of the only two listed drugs against IPF. Regorafenib is a novel, orally active, multi-kinase inhibitor that has similar targets to nintedanib and is applied to treat colorectal cancer and gastrointestinal stromal tumors in patients. In this study, we first identified that regorafenib could alleviate bleomycin-induced pulmonary fibrosis in mice. The in vivo experiments indicated that regorafenib suppresses collagen accumulation and myofibroblast activation. Further in vitro mechanism studies showed that regorafenib inhibits the activation and migration of myofibroblasts and extracellular matrix production, mainly through suppressing the transforming growth factor (TGF)-β1/Smad and non-Smad signaling pathways. In vitro studies have also indicated that regorafenib could augment autophagy in myofibroblasts by suppressing TGF-β1/mTOR (mechanistic target of rapamycin) signaling, and could promote apoptosis in myofibroblasts. In conclusion, regorafenib attenuates bleomycin-induced pulmonary fibrosis by suppressing the TGF-β1 signaling pathway.


Blood ◽  
2008 ◽  
Vol 112 (6) ◽  
pp. 2500-2507 ◽  
Author(s):  
Yoshiyuki Yamada ◽  
Abel Sanchez-Aguilera ◽  
Eric B. Brandt ◽  
Melissa McBride ◽  
Nabeel J. H. Al-Moamen ◽  
...  

Abstract Expression of the fusion gene FIP1-like 1/platelet-derived growth factor receptor alpha (FIP1L1/PDGFRα, F/P) and dysregulated c-kit tyrosine kinase activity are associated with systemic mastocytosis (SM) and chronic eosinophilic leukemia (CEL)/hypereosinophilic syndrome (HES). We analyzed SM development and pathogenesis in a murine CEL model induced by F/P in hematopoietic stem cells and progenitors (HSCs/Ps) and T-cell overexpression of IL-5 (F/P-positive CEL mice). These mice had more mast cell (MC) infiltration in the bone marrow (BM), spleen, skin, and small intestine than control mice that received a transplant of IL-5 transgenic HSCs/Ps. Moreover, intestinal MC infiltration induced by F/P expression was severely diminished, but not abolished, in mice injected with neutralizing anti–c-kit antibody, suggesting that endogenous stem cell factor (SCF)/c-kit interaction synergizes with F/P expression to induce SM. F/P-expressing BM HSCs/Ps showed proliferation and MC differentiation in vitro in the absence of cytokines. SCF stimulated greater migration of F/P-expressing MCs than mock vector–transduced MCs. F/P-expressing bone marrow–derived mast cells (BMMCs) survived longer than mock vector control BMMCs in cytokine-deprived conditions. The increased proliferation and survival correlated with increased SCF-induced Akt activation. In summary, F/P synergistically promotes MC development, activation, and survival in vivo and in vitro in response to SCF.


Blood ◽  
2010 ◽  
Vol 116 (8) ◽  
pp. 1244-1253 ◽  
Author(s):  
Claude Capron ◽  
Catherine Lacout ◽  
Yann Lécluse ◽  
Valérie Jalbert ◽  
Hédia Chagraoui ◽  
...  

Abstract Transforming growth factor-β1 (TGF-β1) is a pleiotropic cytokine with major in vitro effects on hematopoietic stem cells (HSCs) and lymphocyte development. Little is known about hematopoiesis from mice with constitutive TGF-β1 inactivation largely because of important embryonic lethality and development of a lethal inflammatory disorder in TGF-β1−/− pups, making these studies difficult. Here, we show that no sign of the inflammatory disorder was detectable in 8- to 10-day-old TGF-β1−/− neonates as judged by both the number of T-activated and T-regulator cells in secondary lymphoid organs and the level of inflammatory cytokines in sera. After T-cell depletion, the inflammatory disease was not transplantable in recipient mice. Bone marrow cells from 8- to 10-day-old TGF-β1−/− neonates showed strikingly impaired short- and long-term reconstitutive activity associated with a parallel decreased in vivo homing capacity of lineage negative (Lin−) cells. In addition an in vitro–reduced survival of immature progenitors (Lin− Kit+ Sca+) was observed. Similar defects were found in liver cells from TGF-β1−/− embryos on day 14 after vaginal plug. These data indicate that TGF-β1 is a critical regulator for in vivo homeostasis of the HSCs, especially for their homing potential.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1398-1398
Author(s):  
Stephen Bartelmez ◽  
Francis W Ruscetti ◽  
Patrick Iversen ◽  
Ashay Bhatwadekar ◽  
Maria Grant

Abstract Previously, we demonstrated that a transient blockade of endogenous transforming growth factor-beta type 1 (TGF-β1) in murine and human HSC accelerates bone marrow engraftment while dramatically reducing the number of HSC needed for long-term reconstitution. CD34+ cells give rise to endothelial progenitor cells (EPC) and have been shown to participate in the repair of damaged vasculature. CXCR4 is the receptor for stromal derived factor (SDF-1), a chemoattractant released by ischemic tissue that guides EPCs to damaged sites. In this study, we examined levels of TGF- β1 mRNA in CD34+ blood and bone marrow (BM) cells of diabetic and non diabetic individuals. We also treated CD34+ cells of diabetic and nondiabetic origin with antisense phosphorodiamidate morpholino oligomers (PMOs) to TGF-β1 and examined surface expression of CXCR-4, migratory response to SDF-1 as well as in vivo reparative function in a model of retinal ischemic injury. Our results show that CD34+ EPC from the blood of diabetic patients are markedly defective in their ability to repair damaged retinal vessels compared to control cells in contrast to CD34+ cells from the diabetic BM. Diabetic CD34+EPC from blood express elevated levels of TGF-β1 mRNA and have a blunted migratory response to SDF-1 compared to controls (p<0.05 and p<0.01 respectively). Transient (2–4 days) blockade of endogenous TGF-β1 using PMOs to TGF- β1 in diabetic CD34+/EPC increases CXCR-4 expression in these cells, enhances their migratory prowess and restores their ability to repair damaged retinal vessels. This approach is an enhanced autologous stem cell therapy based on a well studied, rapid and reversible modification of bone marrow CD34+EPCs derived from the diabetic patient.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1078-1078
Author(s):  
Ivan Sloma ◽  
Suzan Imren ◽  
Yun Zhao ◽  
Keith Humphries ◽  
Connie J. Eaves

Abstract Analysis of the leukemic stem cell compartment in CML patients with chronic phase disease remains a major challenge. This is due to the usually low frequency of these cells in the bone marrow and blood of most patients regardless of the WBC count and the fact that they are typically outnumbered by normal hematopoietic stem cells from which they cannot be currently separated. Moreover, thus far it has not been possible to identify conditions for their selective expansion in vitro or in vivo. To pursue this goal, we have begun to explore the effects of certain HOX gene-containing constructs on primitive chronic phase CML cells based on previous evidence that these genes markedly enhance the expansion of primitive normal murine and human cord blood cell numbers without inducing leukemia. Lineage-negative peripheral blood or bone marrow cells from 3 chronic phase CML patients (with >93%, <20% and <6% Ph+ LTC-ICs by G-banding karyotyping) were pre-stimulated overnight in a medium containing a serum substitute and 100 ng/ml hSteel Factor (SF), 100 ng/ml hFlt3-ligand and 20 ng/ml each of hIL-3, hIL-6 and hG-CSF. Cells were then exposed to a lenti-PGK-GFP virus with or without an upstream MDUS-NUP98-HOXA10 homeodomain (HD) element for 5 hours in the same medium. After removal of the virus, the cells were maintained in culture under the same conditions for 2 more days to allow full expression of the transduced genes. At this point, both cultures contained the same number of total cells, GFP+ cells and clonogenic progenitors (BFU-E + CFU-GM + CFU-GEMM); i.e., 2.2±0.5 x105 vs 2.2±0.6 x105 total cells, 1.0±0.2 x105 vs 1.3±0.3 x105 GFP+ cells, 3.6±1.7 x104 vs 3.4±1.7 x104 total CFCs and 1.7±0.9 x104 vs 2.4±1.3 x104 GFP+ CFCs per 105 starting lin- cells. However, after the 2-day post-transduction, cells had been maintained for 6 weeks in longterm cultures (LTCs) containing murine stromal cells producing hIL-3, hSF and hG-CSF, we noted a markedly higher (4 to 74-fold) output of CFCs from the NUP98-HOXA10HD-transduced cells. Moreover, whereas the proportion of GFP+ CFCs in the 2-day post-transduction cultures was on average only 31% and 48 % for the control and tested cells respectively, this increased to >98% in the 6-week LTCs initiated with cells that were overexpressing NUP98-HOXA10HD but remained constant at 39% in the control LTCs - suggesting a significant growth advantage conferred by the NUP98A10HD transgene. Importantly, RT-PCR genotyping of the colonies in these assays showed the majority of LTC-IC-derived CFCs from the NUP98-HOXA10HD-transduced cells to be BCR-ABL+, indicative of an even greater output of CFCs by the NUP98-HOXA10HD transduced BCR-ABL+ vs normal cells. These results highlight the potential of NUP98-HOXA10HD to selectively expand primitive CML cells isolated directly from chronic phase patients which will facilitate their further investigation and use to screen and validate new therapeutic agents.


Blood ◽  
1999 ◽  
Vol 94 (6) ◽  
pp. 1961-1970 ◽  
Author(s):  
Sumio Sakamaki ◽  
Yasuo Hirayama ◽  
Takuya Matsunaga ◽  
Hiroyuki Kuroda ◽  
Toshiro Kusakabe ◽  
...  

Abstract The present study was designed to test the concept that platelets release a humoral factor that plays a regulatory role in megakaryopoiesis. The results showed that, among various hematoregulatory cytokines examined, transforming growth factor-β1 (TGF-β1) was by far the most potent enhancer of mRNA expression of bone marrow stromal thrombopoietin (TPO), a commitment of lineage specificity. The TPO, in turn, induced TGF-β receptors I and II on megakaryoblasts at the midmegakaryopoietic stage; at this stage, TGF-β1 was able to arrest the maturation of megakaryocyte colony-forming units (CFU-Meg). This effect was relatively specific when compared with its effect on burst-forming unit-erythroid (BFU-E) or colony-forming unit–granulocyte-macrophage (CFU-GM). In patients with idiopathic thrombocytopenic purpura (ITP), the levels of both TGF-β1 and stromal TPO mRNA were correlatively increased and an arrest of megakaryocyte maturation was observed. These in vivo findings are in accord with the aforementioned in vitro results. Thus, the results of the present investigation suggest that TGF-β1 is one of the pathophysiological feedback regulators of megakaryopoiesis.


Blood ◽  
1999 ◽  
Vol 94 (6) ◽  
pp. 1961-1970 ◽  
Author(s):  
Sumio Sakamaki ◽  
Yasuo Hirayama ◽  
Takuya Matsunaga ◽  
Hiroyuki Kuroda ◽  
Toshiro Kusakabe ◽  
...  

The present study was designed to test the concept that platelets release a humoral factor that plays a regulatory role in megakaryopoiesis. The results showed that, among various hematoregulatory cytokines examined, transforming growth factor-β1 (TGF-β1) was by far the most potent enhancer of mRNA expression of bone marrow stromal thrombopoietin (TPO), a commitment of lineage specificity. The TPO, in turn, induced TGF-β receptors I and II on megakaryoblasts at the midmegakaryopoietic stage; at this stage, TGF-β1 was able to arrest the maturation of megakaryocyte colony-forming units (CFU-Meg). This effect was relatively specific when compared with its effect on burst-forming unit-erythroid (BFU-E) or colony-forming unit–granulocyte-macrophage (CFU-GM). In patients with idiopathic thrombocytopenic purpura (ITP), the levels of both TGF-β1 and stromal TPO mRNA were correlatively increased and an arrest of megakaryocyte maturation was observed. These in vivo findings are in accord with the aforementioned in vitro results. Thus, the results of the present investigation suggest that TGF-β1 is one of the pathophysiological feedback regulators of megakaryopoiesis.


Blood ◽  
2021 ◽  
Author(s):  
Julia Tilburg ◽  
Isabelle C. Becker ◽  
Joseph E Italiano

Platelets, small, anucleate cell fragments, derive from large precursor cells, megakaryocytes (MKs), that reside in the bone marrow. MKs emerge from hematopoietic stem cells in a complex differentiation process that involves cytoplasmic maturation, including the formation of the demarcation membrane system, and polyploidization. The main function of MKs is the generation of platelets, which predominantly occurs through the release of long, microtubule-rich proplatelets into vessel sinusoids. However, the idea of a one-dimensional role of MKs as platelet precursors is currently being questioned due to advances in high resolution microscopy and single-cell Omics. On the one hand, recent findings suggest that proplatelet formation from bone marrow-derived MKs is not the only mechanism of platelet production, but that it might also occur through budding of the plasma membrane and in distant organs like lung or liver. On the other hand, novel evidence suggests that MKs do not only maintain physiological platelet levels but further contribute to bone marrow homeostasis through the release of extracellular vesicles or cytokines such as transforming growth factor β1 or platelet factor 4. The notion of multitasking MKs was reinforced in recent studies using single cell RNA sequencing approaches on MKs derived from adult and fetal bone marrow and lungs, leading to the identification of different MK subsets that appear to exhibit immunomodulatory or secretory roles. In the following, novel insights into the mechanisms leading to proplatelet formation in vitro and in vivo will be reviewed and the hypothesis of megakaryocytes as immunoregulatory cells will be critically discussed.


Blood ◽  
1997 ◽  
Vol 89 (11) ◽  
pp. 3919-3924 ◽  
Author(s):  
Jean C.Y. Wang ◽  
Monica Doedens ◽  
John E. Dick

Abstract We have previously reported the development of in vivo functional assays for primitive human hematopoietic cells based on their ability to repopulate the bone marrow (BM) of severe combined immunodeficient (SCID) and nonobese diabetic/SCID (NOD/SCID) mice following intravenous transplantation. Accumulated data from gene marking and cell purification experiments indicate that the engrafting cells (defined as SCID-repopulating cells or SRC) are biologically distinct from and more primitive than most cells that can be assayed in vitro. Here we demonstrate through limiting dilution analysis that the NOD/SCID xenotransplant model provides a quantitative assay for SRC. Using this assay, the frequency of SRC in cord blood (CB) was found to be 1 in 9.3 × 105 cells. This was significantly higher than the frequency of 1 SRC in 3.0 × 106 adult BM cells or 1 in 6.0 × 106 mobilized peripheral blood (PB) cells from normal donors. Mice transplanted with limiting numbers of SRC were engrafted with both lymphoid and multilineage myeloid human cells. This functional assay is currently the only available method for quantitative analysis of human hematopoietic cells with repopulating capacity. Both CB and mobilized PB are increasingly being used as alternative sources of hematopoietic stem cells in allogeneic transplantation. Thus, the findings reported here will have important clinical as well as biologic implications.


Blood ◽  
2007 ◽  
Vol 110 (7) ◽  
pp. 2276-2285 ◽  
Author(s):  
Maria De La Luz Sierra ◽  
Paola Gasperini ◽  
Peter J. McCormick ◽  
Jinfang Zhu ◽  
Giovanna Tosato

The mechanisms underlying granulocyte-colony stimulating factor (G-CSF)–induced mobilization of granulocytic lineage cells from the bone marrow to the peripheral blood remain elusive. We provide evidence that the transcriptional repressor growth factor independence-1 (Gfi-1) is involved in G-CSF–induced mobilization of granulocytic lineage cells from the bone marrow to the peripheral blood. We show that in vitro and in vivo G-CSF promotes expression of Gfi-1 and down-regulates expression of CXCR4, a chemokine receptor essential for the retention of hematopoietic stem cells and granulocytic cells in the bone marrow. Gfi-1 binds to DNA sequences upstream of the CXCR4 gene and represses CXCR4 expression in myeloid lineage cells. As a consequence, myeloid cell responses to the CXCR4 unique ligand SDF-1 are reduced. Thus, Gfi-1 not only regulates hematopoietic stem cell function and myeloid cell development but also probably promotes the release of granulocytic lineage cells from the bone marrow to the peripheral blood by reducing CXCR4 expression and function.


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