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Cell Aug 2023The bone marrow in the skull is important for shaping immune responses in the brain and meninges, but its molecular makeup among bones and relevance in human diseases...
The bone marrow in the skull is important for shaping immune responses in the brain and meninges, but its molecular makeup among bones and relevance in human diseases remain unclear. Here, we show that the mouse skull has the most distinct transcriptomic profile compared with other bones in states of health and injury, characterized by a late-stage neutrophil phenotype. In humans, proteome analysis reveals that the skull marrow is the most distinct, with differentially expressed neutrophil-related pathways and a unique synaptic protein signature. 3D imaging demonstrates the structural and cellular details of human skull-meninges connections (SMCs) compared with veins. Last, using translocator protein positron emission tomography (TSPO-PET) imaging, we show that the skull bone marrow reflects inflammatory brain responses with a disease-specific spatial distribution in patients with various neurological disorders. The unique molecular profile and anatomical and functional connections of the skull show its potential as a site for diagnosing, monitoring, and treating brain diseases.
Topics: Animals; Humans; Mice; Bone Marrow; Brain; Carrier Proteins; Nervous System Diseases; Positron-Emission Tomography; Receptors, GABA; Skull
PubMed: 37562402
DOI: 10.1016/j.cell.2023.07.009 -
Bone Marrow Transplantation Jul 2023Sinusoidal obstruction syndrome, also known as veno-occlusive disease (SOS/VOD), is a potentially life-threatening complication that can develop after hematopoietic cell... (Review)
Review
Diagnosis and severity criteria for sinusoidal obstruction syndrome/veno-occlusive disease in adult patients: a refined classification from the European society for blood and marrow transplantation (EBMT).
Sinusoidal obstruction syndrome, also known as veno-occlusive disease (SOS/VOD), is a potentially life-threatening complication that can develop after hematopoietic cell transplantation (HCT). A new definition for diagnosis, and a severity grading system for SOS/VOD in adult patients, was reported a few years ago on behalf of the European Society for Blood and Marrow Transplantation (EBMT). The aim of this work is to update knowledge regarding diagnosis and severity assessment of SOS/VOD in adult patients, and also its pathophysiology and treatment. In particular, we now propose to refine the previous classification and distinguish probable, clinical and proven SOS/VOD at diagnosis. We also provide an accurate definition of multiorgan dysfunction (MOD) for SOS/VOD severity grading based on Sequential Organ Failure Assessment (SOFA) score.
Topics: Humans; Adult; Hepatic Veno-Occlusive Disease; Bone Marrow; Vascular Diseases; Syndrome; Hematopoietic Stem Cell Transplantation
PubMed: 37095231
DOI: 10.1038/s41409-023-01992-8 -
Arteriosclerosis, Thrombosis, and... Nov 2023Megakaryocytes are commonly known as large, polyploid, bone marrow resident cells that contribute to hemostasis through the production of platelets. Soon after their... (Review)
Review
Megakaryocytes are commonly known as large, polyploid, bone marrow resident cells that contribute to hemostasis through the production of platelets. Soon after their discovery in the 19th century, megakaryocytes were described in tissue locations other than the bone marrow, specifically in the lungs and the blood circulation. However, the localization of megakaryocytes in the lungs and the contribution of lung megakaryocytes to the general platelet pool has only recently been appreciated. Moreover, the conception of megakaryocytes as uniform cells with the sole purpose of platelet production has been challenged. Here, we review the literature on megakaryocyte cell identity and location with a special focus on recent observations of megakaryocyte subpopulations identified by transcriptomic analyses.
Topics: Megakaryocytes; Blood Platelets; Bone Marrow; Bone Marrow Cells; Thrombopoiesis
PubMed: 37675634
DOI: 10.1161/ATVBAHA.123.318782 -
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 -
Nature Cell Biology Dec 2023The bone marrow contains peripheral nerves that promote haematopoietic regeneration after irradiation or chemotherapy (myeloablation), but little is known about how this...
The bone marrow contains peripheral nerves that promote haematopoietic regeneration after irradiation or chemotherapy (myeloablation), but little is known about how this is regulated. Here we found that nerve growth factor (NGF) produced by leptin receptor-expressing (LepR) stromal cells is required to maintain nerve fibres in adult bone marrow. In nerveless bone marrow, steady-state haematopoiesis was normal but haematopoietic and vascular regeneration were impaired after myeloablation. LepR cells, and the adipocytes they gave rise to, increased NGF production after myeloablation, promoting nerve sprouting in the bone marrow and haematopoietic and vascular regeneration. Nerves promoted regeneration by activating β2 and β3 adrenergic receptor signalling in LepR cells, and potentially in adipocytes, increasing their production of multiple haematopoietic and vascular regeneration growth factors. Peripheral nerves and LepR cells thus promote bone marrow regeneration through a reciprocal relationship in which LepR cells sustain nerves by synthesizing NGF and nerves increase regeneration by promoting the production of growth factors by LepR cells.
Topics: Bone Marrow; Receptors, Leptin; Bone Marrow Cells; Nerve Growth Factor; Hematopoietic Stem Cells; Nerve Regeneration
PubMed: 38012403
DOI: 10.1038/s41556-023-01284-9 -
Cell Reports Jul 2023Human bone marrow (BM) plasma cells are heterogeneous, ranging from newly arrived antibody-secreting cells (ASCs) to long-lived plasma cells (LLPCs). We provide...
Human bone marrow (BM) plasma cells are heterogeneous, ranging from newly arrived antibody-secreting cells (ASCs) to long-lived plasma cells (LLPCs). We provide single-cell transcriptional resolution of 17,347 BM ASCs from five healthy adults. Fifteen clusters are identified ranging from newly minted ASCs (cluster 1) expressing MKI67 and high major histocompatibility complex (MHC) class II that progress to late clusters 5-8 through intermediate clusters 2-4. Additional ASC clusters include the following: immunoglobulin (Ig) M predominant (likely of extra-follicular origin), interferon responsive, and high mitochondrial activity. Late ASCs are distinguished by G2M checkpoints, mammalian target of rapamycin (mTOR) signaling, distinct metabolic pathways, CD38 expression, utilization of tumor necrosis factor (TNF)-receptor superfamily members, and two distinct maturation pathways involving TNF signaling through nuclear factor κB (NF-κB). This study provides a single-cell atlas and molecular roadmap of LLPC maturation trajectories essential in the BM microniche. Altogether, understanding BM ASC heterogeneity in health and disease enables development of new strategies to enhance protective ASCs and to deplete pathogenic ones.
Topics: Adult; Humans; Plasma Cells; Bone Marrow; Antibody-Producing Cells; Histocompatibility Antigens Class II; Single-Cell Analysis; Bone Marrow Cells
PubMed: 37355988
DOI: 10.1016/j.celrep.2023.112682 -
Cell Stem Cell Feb 2024The paradigmatic hematopoietic tree model is increasingly recognized to be limited, as it is based on heterogeneous populations largely defined by non-homeostatic assays...
The paradigmatic hematopoietic tree model is increasingly recognized to be limited, as it is based on heterogeneous populations largely defined by non-homeostatic assays testing cell fate potentials. Here, we combine persistent labeling with time-series single-cell RNA sequencing to build a real-time, quantitative model of in vivo tissue dynamics for murine bone marrow hematopoiesis. We couple cascading single-cell expression patterns with dynamic changes in differentiation and growth speeds. The resulting explicit linkage between molecular states and cellular behavior reveals widely varying self-renewal and differentiation properties across distinct lineages. Transplanted stem cells show strong acceleration of differentiation at specific stages of erythroid and neutrophil production, illustrating how the model can quantify the impact of perturbations. Our reconstruction of dynamic behavior from snapshot measurements is akin to how a kinetoscope allows sequential images to merge into a movie. We posit that this approach is generally applicable to understanding tissue-scale dynamics at high resolution.
Topics: Animals; Mice; Bone Marrow; Hematopoietic Stem Cells; Hematopoiesis; Cell Differentiation
PubMed: 38183977
DOI: 10.1016/j.stem.2023.12.001 -
Blood Jun 2023The bone marrow microenvironment supports leukocyte mobilization and differentiation and controls the development of leukemias, including acute myeloid leukemia (AML)....
The bone marrow microenvironment supports leukocyte mobilization and differentiation and controls the development of leukemias, including acute myeloid leukemia (AML). Here, we found that the development of AML xenotransplants was suppressed in mice with osteoclasts tuberous sclerosis 1 (Tsc1) deletion. Tsc1-deficient osteoclasts released a high level of interleukin-34 (IL-34), which efficiently induced AML cell differentiation and prevented AML progression in various preclinical models. Conversely, AML development was accelerated in mice deficient in IL-34. Interestingly, IL-34 inhibited AML independent of its known receptors but bound directly to triggering receptor expressed on myeloid cells 2 (TREM2), a key hub of immune signals. TREM2-deficient AML cells and normal myeloid cells were resistant to IL-34 treatment. Mechanistically, IL-34-TREM2 binding rapidly phosphorylated Ras protein activator like 3 and inactivated extracellular signal-regulated protein kinase 1/2 signaling to prevent AML cell proliferation and stimulate differentiation. Furthermore, TREM2 was downregulated in patients with AML and associated with a poor prognosis. This study identified TREM2 as a novel receptor for IL-34, indicating a promising strategy for overcoming AML differentiation blockade in patients with AML.
Topics: Animals; Mice; Bone Marrow; Carrier Proteins; Interleukins; Leukemia, Myeloid, Acute; Signal Transduction; Tumor Microenvironment
PubMed: 37001042
DOI: 10.1182/blood.2022018619 -
Nature Communications Jun 2023Metastasis is the major cause of cancer-related deaths. Neuroblastoma (NB), a childhood tumor has been molecularly defined at the primary cancer site, however, the bone...
Metastasis is the major cause of cancer-related deaths. Neuroblastoma (NB), a childhood tumor has been molecularly defined at the primary cancer site, however, the bone marrow (BM) as the metastatic niche of NB is poorly characterized. Here we perform single-cell transcriptomic and epigenomic profiling of BM aspirates from 11 subjects spanning three major NB subtypes and compare these to five age-matched and metastasis-free BM, followed by in-depth single cell analyses of tissue diversity and cell-cell interactions, as well as functional validation. We show that cellular plasticity of NB tumor cells is conserved upon metastasis and tumor cell type composition is NB subtype-dependent. NB cells signal to the BM microenvironment, rewiring via macrophage mgration inhibitory factor and midkine signaling specifically monocytes, which exhibit M1 and M2 features, are marked by activation of pro- and anti-inflammatory programs, and express tumor-promoting factors, reminiscent of tumor-associated macrophages. The interactions and pathways characterized in our study provide the basis for therapeutic approaches that target tumor-to-microenvironment interactions.
Topics: Humans; Child; Bone Marrow; Monocytes; Transcriptome; Epigenomics; Bone Marrow Neoplasms; Neuroblastoma; Tumor Microenvironment
PubMed: 37365178
DOI: 10.1038/s41467-023-39210-0 -
Experimental & Molecular Medicine Mar 2024Hematopoiesis can occur outside of the bone marrow during inflammatory stress to increase the production of primarily myeloid cells at extramedullary sites; this process... (Review)
Review
Hematopoiesis can occur outside of the bone marrow during inflammatory stress to increase the production of primarily myeloid cells at extramedullary sites; this process is known as extramedullary hematopoiesis (EMH). As observed in a broad range of hematologic and nonhematologic diseases, EMH is now recognized for its important contributions to solid tumor pathology and prognosis. To initiate EMH, hematopoietic stem cells (HSCs) are mobilized from the bone marrow into the circulation and to extramedullary sites such as the spleen and liver. At these sites, HSCs primarily produce a pathological subset of myeloid cells that contributes to tumor pathology. The EMH HSC niche, which is distinct from the bone marrow HSC niche, is beginning to be characterized. The important cytokines that likely contribute to initiating and maintaining the EMH niche are KIT ligands, CXCL12, G-CSF, IL-1 family members, LIF, TNFα, and CXCR2. Further study of the role of EMH may offer valuable insights into emergency hematopoiesis and therapeutic approaches against cancer. Exciting future directions for the study of EMH include identifying common and distinct EMH mechanisms in cancer, infectious diseases, and chronic autoimmune diseases to control these conditions.
Topics: Humans; Hematopoiesis, Extramedullary; Hematopoiesis; Hematopoietic Stem Cells; Bone Marrow; Neoplasms; Chronic Disease
PubMed: 38443597
DOI: 10.1038/s12276-024-01192-4