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Basic Research in Cardiology Aug 2023Pharmacological inhibition of factor Xa by rivaroxaban has been shown to mediate cardioprotection and is frequently used in patients with, e.g., atrial fibrillation....
Pharmacological inhibition of factor Xa by rivaroxaban has been shown to mediate cardioprotection and is frequently used in patients with, e.g., atrial fibrillation. Rivaroxaban's anti-inflammatory actions are well known, but the underlying mechanisms are still incompletely understood. To date, no study has focused on the effects of rivaroxaban on the bone marrow (BM), despite growing evidence that the BM and its activation are of major importance in the development/progression of cardiovascular disease. Thus, we examined the impact of rivaroxaban on BM composition under homeostatic conditions and in response to a major cardiovascular event. Rivaroxaban treatment of mice for 7 days markedly diminished mature leukocytes in the BM. While apoptosis of BM-derived mature myeloid leukocytes was unaffected, lineage-negative BM cells exhibited a differentiation arrest at the level of granulocyte-monocyte progenitors, specifically affecting neutrophil maturation via downregulation of the transcription factors Spi1 and Csfr1. To assess whether this persists also in situations of increased leukocyte demand, mice were subjected to cardiac ischemia/reperfusion injury (I/R): 7 d pretreatment with rivaroxaban led to reduced cardiac inflammation 72 h after I/R and lowered circulating leukocyte numbers. However, BM myelopoiesis showed a rescue of the leukocyte differentiation arrest, indicating that rivaroxaban's inhibitory effects are restricted to homeostatic conditions and are mainly abolished during emergency hematopoiesis. In translation, ST-elevation MI patients treated with rivaroxaban also exhibited reduced circulating leukocyte numbers. In conclusion, we demonstrate that rivaroxaban attenuates neutrophil maturation in the BM, which may offer a therapeutic option to limit overshooting of the immune response after I/R.
Topics: Animals; Mice; Bone Marrow; Rivaroxaban; Neutrophils; Hematopoiesis; Leukocytes; Bone Marrow Cells
PubMed: 37580509
DOI: 10.1007/s00395-023-01001-5 -
Cancers Aug 2023Wnt/β-catenin signaling is critically required for the development and maintenance of leukemia stem cells (LSCs) in acute myeloid leukemia (AML) by constitutive...
Wnt/β-catenin signaling is critically required for the development and maintenance of leukemia stem cells (LSCs) in acute myeloid leukemia (AML) by constitutive activation of myeloid regeneration-related pathways. Cell-intrinsic activation of canonical Wnt signaling propagates in the nucleus by β-catenin translocation, where it induces expression of target oncogenes such as , and . As the Wnt/β-catenin pathway is now well established to be a key oncogenic signaling pathway promoting leukemic myelopoiesis, targeting it would be an effective strategy to impair LSC functionality. Although the effects of the adenosine analogue cordycepin in repressing β-catenins and destabilizing the LSC niche have been highlighted, the cellular and molecular effects on AML-LSC have not been fully clarified. In the present study, we evaluated the potency and efficacy of cordycepin, a selective repressor of Wnt/β-catenin signaling with anti-leukemia properties, on the AC133 LSC fraction. Cordycepin effectively reduces cell viability of the AC133 LSCs in the MUTZ-2 cell model and patient-derived cells through the induction of apoptosis. By Wnt-targeted RNA sequencing panel, we highlighted the re-expression of WIF1 and DKK1 among others, and the consequent downregulation of MYC and PROM1 (CD133) following MUTZ-2 cell exposure to increasing doses of cordycepin. Our results provide new insights into the molecular circuits involved in pharmacological inhibition mediated by cordycepin reinforcing the potential of targeting the Wnt/β-catenin and co-regulatory complexes in AML.
PubMed: 37568748
DOI: 10.3390/cancers15153931 -
ELife Aug 2023Monocytes are heterogeneous innate effector leukocytes generated in the bone marrow and released into circulation in a CCR2-dependent manner. During infection or...
Monocytes are heterogeneous innate effector leukocytes generated in the bone marrow and released into circulation in a CCR2-dependent manner. During infection or inflammation, myelopoiesis is modulated to rapidly meet the demand for more effector cells. Danger signals from peripheral tissues can influence this process. Herein we demonstrate that repetitive TLR7 stimulation via the epithelial barriers drove a potent emergency bone marrow monocyte response in mice. This process was unique to TLR7 activation and occurred independently of the canonical CCR2 and CX3CR1 axes or prototypical cytokines. The monocytes egressing the bone marrow had an immature Ly6C-high profile and differentiated into vascular Ly6C-low monocytes and tissue macrophages in multiple organs. They displayed a blunted cytokine response to further TLR7 stimulation and reduced lung viral load after RSV and influenza virus infection. These data provide insights into the emergency myelopoiesis likely to occur in response to the encounter of single-stranded RNA viruses at barrier sites.
Topics: Animals; Mice; Cytokines; Lung; Mice, Inbred C57BL; Monocytes; Myelopoiesis; Toll-Like Receptor 7; Virus Diseases
PubMed: 37566453
DOI: 10.7554/eLife.85647 -
Leukemia Research Reports 2023Transient abnormal myelopoiesis (TAM) is a transient, clonal myeloproliferative disorder unique to Down Syndrome (DS) babies. It is characterized by increased peripheral...
INTRODUCTION
Transient abnormal myelopoiesis (TAM) is a transient, clonal myeloproliferative disorder unique to Down Syndrome (DS) babies. It is characterized by increased peripheral blasts and presence of mutation. The clinical spectrum ranges from jaundice and hepatosplenomegaly to multi-organ failure and death. Here we present a case of a premature baby with DS diagnosed to have TAM with extramedullary involvement at birth who had a fatal outcome.
CASE REPORT
A 30.3-week-old female fetus with DS had leukocytosis (WBC: 187.82 K/uL) with neutrophilia (ANC 27.65 K/uL), macrocytic anemia (RBC: 2.41 m/uL, Hb 8.8 g/dL, MCV 108.3, MCH 36.5, MCHC 33.7) and thrombocytosis (platelet count 361 K/uL) at birth. Liver panels demonstrated normal bilirubin levels with elevated liver enzymes (AST = 239 U/L, ALT = 216 U/L).
RESULTS
Peripheral smear showed marked leukocytosis with increased blasts (70%), nucleated RBCs, giant platelets, and megakaryocytic elements. Flow cytometry demonstrated two populations of cells: 20% myeloblasts and 26% dim CD45 CD34- cells. mutation was present. Based on these findings a diagnosis of TAM with extramedullary hematopoiesis was made. She received two cycles of cytarabine chemotherapy. Though her WBC levels reached a low of 18.93 K/uL, she developed multi-organ failure, eventually leading to death on day 45.
DISCUSSION
TAM is a transient condition resulting in disease resolution in around 80% of cases. Death is reported in 10% of cases. Risk factors associated with early death include prematurity, hyperleukocytosis, elevated bilirubin levels. Management of high-risk babies with chemotherapy is recommended to improve survival.
PubMed: 37560406
DOI: 10.1016/j.lrr.2023.100381 -
Inflammation Research : Official... Aug 2023Airway inflammation in chronic inflammatory lung diseases (e.g. bronchiectasis) is partly mediated by neutrophil-derived serine protease (NSP)/antiprotease imbalance....
BACKGROUND
Airway inflammation in chronic inflammatory lung diseases (e.g. bronchiectasis) is partly mediated by neutrophil-derived serine protease (NSP)/antiprotease imbalance. NSPs are activated during neutrophil myelopoiesis in bone marrow by cathepsin C (CatC; DPP1). CatC is therefore an attractive target to reduce NSP activity in the lungs of patients with bronchiectasis, restoring the protease/antiprotease balance. We report results from the preclinical pharmacological assessment of the novel CatC inhibitor BI 1291583.
METHODS
Binding kinetics of BI 1291583 to human CatC were determined by surface plasmon resonance. In vitro inhibition of human CatC activity was determined by CatC-specific fluorescent assay, and selectivity was assessed against related cathepsins and unrelated proteases. Inhibition of NSP neutrophil elastase (NE) production was assessed in a human neutrophil progenitor cell line. In vivo inhibition of NE and NSP proteinase 3 (PR3) in bronchoalveolar lavage fluid (BALF) neutrophils after lipopolysaccharide (LPS) challenge and distribution of BI 1291583 was determined in a mouse model.
RESULTS
BI 1291583 bound human CatC in a covalent, reversible manner, selectively and fully inhibiting CatC enzymatic activity. This inhibition translated to concentration-dependent inhibition of NE activation in U937 cells and dose-dependent, almost-complete inhibition of NE and PR3 activity in BALF neutrophils in an in vivo LPS-challenge model in mice. BI 1291583 exhibited up to 100 times the exposure in the target tissue bone marrow compared with plasma.
CONCLUSION
BI 1291583-mediated inhibition of CatC is expected to restore the protease-antiprotease balance in the lungs of patients with chronic airway inflammatory diseases such as bronchiectasis.
Topics: Animals; Humans; Mice; Bronchiectasis; Cathepsin C; Leukocyte Elastase; Lipopolysaccharides; Neutrophils; Protease Inhibitors; Serine Proteases
PubMed: 37542002
DOI: 10.1007/s00011-023-01774-4 -
Molecular Therapy : the Journal of the... Sep 2023Lymphodepleting pre-conditioning is a nearly universal component of T cell adoptive transfer protocols. The side effects of pre-conditioning regimens used in adoptive...
Lymphodepleting pre-conditioning is a nearly universal component of T cell adoptive transfer protocols. The side effects of pre-conditioning regimens used in adoptive cell therapy are clinically significant and include pan-cytopenia, immune suppression, and reactive myelopoiesis. We conducted studies to test the hypothesis that the mechanisms underlying effective engraftment are cell autonomous and not dependent on a lymphodepleted host immune status. These studies leveraged mouse models to examine the role of Stat5 signaling during T cell adoptive transfer. We observed that, by transiently expressing a constitutively active mutamer of Stat5b during the process of adoptive transfer, we could completely obviate the need for lymphodepletion prior to adoptive transfer. Using several functional assays, we benchmark the function of the engrafted T cells against T cells transferred after conventional lymphodepletion. These studies identify a cell-autonomous mechanism driven by transient Stat5b signaling with lasting effects on T cell phenotype and function. Furthermore, the results presented suggest that adoptive T cell therapy could be improved by removing lymphodepletion protocols entirely and replacing them with RNA transfection of T cells with transcripts encoding active Stat5.
Topics: Mice; Animals; T-Lymphocytes; Adoptive Transfer; Signal Transduction; Immunotherapy, Adoptive
PubMed: 37481703
DOI: 10.1016/j.ymthe.2023.07.015 -
International Journal of Molecular... Jul 2023Fanconi anemia (FA) develops due to a mutation in one of the FANC genes that are involved in the repair of interstrand crosslinks (ICLs). FANCG, a member of the FA core...
Fanconi anemia (FA) develops due to a mutation in one of the FANC genes that are involved in the repair of interstrand crosslinks (ICLs). FANCG, a member of the FA core complex, is essential for ICL repair. Previous FANCG-deficient mouse models were generated with drug-based selection cassettes in mixed mice backgrounds, leading to a disparity in the interpretation of genotype-related phenotype. We created a -KO (KO) mouse model using CRISPR/Cas9 to exclude these confounders. The entire locus was targeted and maintained on the immunological well-characterized C57BL/6J background. The intercrossing of heterozygous mice resulted in sub-Mendelian numbers of homozygous mice, suggesting the loss of FANCG can be embryonically lethal. KO mice displayed infertility and hypogonadism, but no other developmental problems. Bone marrow analysis revealed a defect in various hematopoietic stem and progenitor subsets with a bias towards myelopoiesis. Cell lines derived from -KO mice were hypersensitive to the crosslinking agents cisplatin and Mitomycin C, and -KO mouse embryonic fibroblasts (MEFs) displayed increased γ-H2AX upon cisplatin treatment. The reconstitution of these MEFs with cDNA corrected for the ICL hypersensitivity. This project provides a new, genetically, and immunologically well-defined -KO mouse model for further in vivo and in vitro studies on FANCG and ICL repair.
Topics: Humans; Animals; Mice; Cisplatin; Fanconi Anemia; Mice, Inbred C57BL; CRISPR-Cas Systems; DNA-Binding Proteins; Fibroblasts; Mitomycin; Phenotype; Fanconi Anemia Complementation Group G Protein
PubMed: 37446306
DOI: 10.3390/ijms241311129 -
Journal of Hematology & Oncology Jul 2023Tumor-associated myeloid cells (TAMCs) are among the most important immune cell populations in the tumor microenvironment, and play a significant role on the efficacy of... (Review)
Review
Tumor-associated myeloid cells (TAMCs) are among the most important immune cell populations in the tumor microenvironment, and play a significant role on the efficacy of immune checkpoint blockade. Understanding the origin of TAMCs was found to be the essential to determining their functional heterogeneity and, developing cancer immunotherapy strategies. While myeloid-biased differentiation in the bone marrow has been traditionally considered as the primary source of TAMCs, the abnormal differentiation of splenic hematopoietic stem and progenitor cells, erythroid progenitor cells, and B precursor cells in the spleen, as well as embryo-derived TAMCs, have been depicted as important origins of TAMCs. This review article provides an overview of the literature with a focus on the recent research progress evaluating the heterogeneity of TAMCs origins. Moreover, this review summarizes the major therapeutic strategies targeting TAMCs with heterogeneous sources, shedding light on their implications for cancer antitumor immunotherapies.
Topics: Humans; Neoplasms; Myeloid Cells; Immunotherapy; Bone Marrow; Hematopoietic Stem Cells; Tumor Microenvironment
PubMed: 37415162
DOI: 10.1186/s13045-023-01473-x -
Signal Transduction and Targeted Therapy Jul 2023Traumatic brain injury (TBI) accelerates fracture healing, but the underlying mechanism remains largely unknown. Accumulating evidence indicates that the central nervous...
Traumatic brain injury (TBI) accelerates fracture healing, but the underlying mechanism remains largely unknown. Accumulating evidence indicates that the central nervous system (CNS) plays a pivotal role in regulating immune system and skeletal homeostasis. However, the impact of CNS injury on hematopoiesis commitment was overlooked. Here, we found that the dramatically elevated sympathetic tone accompanied with TBI-accelerated fracture healing; chemical sympathectomy blocks TBI-induced fracture healing. TBI-induced hypersensitivity of adrenergic signaling promotes the proliferation of bone marrow hematopoietic stem cells (HSCs) and swiftly skews HSCs toward anti-inflammation myeloid cells within 14 days, which favor fracture healing. Knockout of β3- or β2-adrenergic receptor (AR) eliminate TBI-mediated anti-inflammation macrophage expansion and TBI-accelerated fracture healing. RNA sequencing of bone marrow cells revealed that Adrb2 and Adrb3 maintain proliferation and commitment of immune cells. Importantly, flow cytometry confirmed that deletion of β2-AR inhibits M2 polarization of macrophages at 7th day and 14th day; and TBI-induced HSCs proliferation was impaired in β3-AR knockout mice. Moreover, β3- and β2-AR agonists synergistically promote infiltration of M2 macrophages in callus and accelerate bone healing process. Thus, we conclude that TBI accelerates bone formation during early stage of fracture healing process by shaping the anti-inflammation environment in the bone marrow. These results implicate that the adrenergic signals could serve as potential targets for fracture management.
Topics: Mice; Animals; Fracture Healing; Bone Marrow; Myelopoiesis; Mice, Knockout; Brain Injuries, Traumatic; Adrenergic Agents
PubMed: 37402714
DOI: 10.1038/s41392-023-01457-w -
The Tohoku Journal of Experimental... Sep 2023Transient abnormal myelopoiesis (TAM) can cause early death in children with Down syndrome, and liver failure is the most common cause of death. The aim of this...
Transient abnormal myelopoiesis (TAM) can cause early death in children with Down syndrome, and liver failure is the most common cause of death. The aim of this single-center retrospective study was to identify a quantitative index for predicting TAM-related mortality at the time of diagnosis. Of the 462 children with Down syndrome admitted to our hospital from 1992 to 2021, we studied 12 infants with TAM-related death and 31 survivors who were diagnosed with TAM. In the death and survival groups, the median gestational ages were 34.9 and 37.1 weeks, respectively (p = 0.12). At diagnosis, the white blood cell (WBC) counts were 99.2 and 36.2 × 10/L (p = 0.011), the hemoglobin concentrations were 131 and 159 g/L (p = 0.009), and the serum albumin concentrations were 23 and 31 g/L (p < 0.001), respectively. The areas under the receiver operating characteristic curve for the abilities of the WBC count, hemoglobin, and serum albumin at diagnosis to predict survival were 0.75, 0.76, and 0.85, respectively. The serum albumin concentration threshold of 28 g/L at diagnosis had sensitivity of 0.79 and specificity of 0.82. Gestational age and serum albumin concentration were entered into a logistic regression model. The serum albumin concentration was an independent indicator of TAM-related death (adjusted odds ratio, 0.78; 95% confidence interval, 0.65-0.93; p = 0.005). In conclusion, a low serum albumin concentration at diagnosis may be a good predictor of TAM-related death.
Topics: Child; Infant; Humans; Down Syndrome; Retrospective Studies; Myelopoiesis; Leukemoid Reaction; Leukocyte Count; Serum Albumin
PubMed: 37344418
DOI: 10.1620/tjem.2023.J051