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Bone marrow aspirate concentrate (BMAC) and adipose-derived stromal vascular fraction (ADSVF) are the most marketed stem cell therapies to treat a variety of conditions in the general population and elite athletes. Both tissues have been used interchangeably clinically even though their detailed composition, heterogeneity, and mechanisms of action have neither been rigorously inventoried nor compared. This lack of information has prevented investigations into ideal dosages and has facilitated anecdata and misinformation. Here, we analyzed single-cell transcriptomes, proteomes, and flow cytometry profiles from paired clinical-grade BMAC and ADSVF. This comparative transcriptional atlas challenges the prevalent notion that there is one therapeutic cell type present in both tissues. We also provide data of surface markers that may enable isolation and investigation of cell (sub)populations. Furthermore, the proteome atlas highlights intertissue and interpatient heterogeneity of injected proteins with potentially regenerative or immunomodulatory capacities. An interactive webtool is available online.

The precise identities of bone marrow resident cells contributing to AML relapse are not fully known. Hollands et al. report early evidence to support the existence of an aberrant monocytic cell population that appears to promote LSC expansion after cytarabine treatment.

Mitochondrial loss and dysfunction drive T cell exhaustion, representing major barriers to successful T cell-based immunotherapies. Here, we describe an innovative platform to supply exogenous mitochondria to T cells, overcoming these limitations. We found that bone marrow stromal cells establish nanotubular connections with T cells and leverage these intercellular highways to transplant stromal cell mitochondria into CD8+ T cells. Optimal mitochondrial transfer required Talin 2 on both donor and recipient cells. CD8+ T cells with donated mitochondria displayed enhanced mitochondrial respiration and spare respiratory capacity. When transferred into tumor-bearing hosts, these supercharged T cells expanded more robustly, infiltrated the tumor more efficiently, and exhibited fewer signs of exhaustion compared with T cells that did not take up mitochondria. As a result, mitochondria-boosted CD8+ T cells mediated superior antitumor responses, prolonging animal survival. These findings establish intercellular mitochondrial transfer as a prototype of organelle medicine, opening avenues to next-generation cell therapies. [Display omitted] • BMSCs transfer mitochondria to CD8+ T cells via intercellular nanotube connections • Mitochondrial transfer between BMSCs and CD8+ T cells depends on Talin 2 • Mitochondrial transfer augments CD8+ T cell mitochondria mass and metabolic fitness • Mitochondria-boosted mouse and human CD8+ T cells exhibit superior antitumor efficacy Transfer of mitochondria via nanotubes from bone marrow stem cells to CD8+ T cells augments cellular metabolism, empowering engineered T cells and tumor-infiltrating lymphocytes to counteract exhaustion and fight tumors more effectively. [ABSTRACT FROM AUTHOR]

At present, the characteristics of double-hit multiple myeloma (DHMM) are unknown. We retrospectively analyzed the clinical data from 433 new diagnosed MM patients and found that DHMM have a higher β2-MG level and percentage of bone marrow plasma cell. Cox regression analysis showed that the prognosis of DHMM was not limited by clinical indicators. The abnormal proliferation of bone marrow in DHMM is obvious, and the proportion of poorly differentiated plasma cell is high. By collecting specimens from our center and performing flow cytometry to analyze the immunophenotypic and functional characteristics of lymphocyte subpopulations, we found that DHMM had a higher ratio of Tregs cells, and the proportion of iTregs cells was also significantly higher than non-DHMM (P < 0.05). Moreover, DHMM had higher levels of TGF-β1 and IL-10, and TGF-β1 and IL-10 were positively correlated with iTregs (P < 0.05). In addition, DHMM was highly expressed PD-1 on CD8 + T cells and had a higher proportion of CD38highTregs cells. In vitro we have shown that the addition of TGF-β1 antibody or CD38 antibody can effectively inhibit the proportion of CD38high Tregs. This study describes the characteristics of DHMM based on bicentric data, which is helpful to better provide theoretical support for the treatment of DHMM. [ABSTRACT FROM AUTHOR]

The article discusses the successful treatment of refractory Epstein-Barr virus-associated haemophagocytic lymphohistiocytosis (EBV-HLH) using a combination of venetoclax, PD-1 blockade, and ruxolitinib. Two cases are presented where patients who did not respond to PD-1 blockade achieved remission after receiving combined venetoclax treatment. The study highlights the potential of BCL-2 inhibitors in supporting PD-1 blockade for EBV-HLH patients, offering a promising therapeutic option when other treatments fail. [Extracted from the article]

Bone marrow stem cells (BMSCs)‐engineered cartilage (BEC) shows promise for clinically repairing cartilage defects. However, when implanted in immunocompetent large animals, BEC becomes susceptible to ossification due to inflammatory infiltration. To address this, a nanofilm isolation approach is developed to enhance BEC's chondrogenic stability. Tacrolimus (FK506), known for its immunosuppressive effect, is integrated into adipic dihydrazide (ADH)‐modified hyaluronic acid (HA), creating an acid‐responsive macromolecular prodrug called FK506@HA‐ADH. This prodrug is then blended with poly(lactic‐co‐glycolic acid) (PLGA) to form electrospun FK506@HA/PLGA nanofilm. Goat‐derived BMSCs are induced in vitro to form BEC, which is enclosed within the FK506@HA/PLGA nanofilm and subcutaneously implanted in autologous goats. The nanofilm acted as a physical barrier, preventing immunocyte infiltration. Additionally, in response to the acidic environment triggered by inflammation and the gradual degradation of PLGA, the FK506@HA‐ADH prodrug is cleaved, releasing FK506 as needed. The released FK506 effectively countered inflammatory cytokines and promoted cartilaginous maturity. These combined mechanisms significantly inhibited BEC hypertrophy and improved its chondrogenic stability within an immunocompetent goat model. This nanofilm‐based isolation strategy established an immunosuppressive niche, successfully preventing endochondral ossification and promoting stable cartilage formation in BEC. These advancements are crucial for translating stem cell‐based therapies into clinical use for cartilage repair. [ABSTRACT FROM AUTHOR]

Background: The one-step membrane technique, using a human acellular dermal matrix (hADM), is an experimental method for treating large bone defects. This eliminates the need for the Masquelet membrane induction step, shortening the procedure while maintaining effectiveness. However, previous studies showed that colonizing hADM with bone marrow mononuclear cells (BMC) worsens healing, likely due to the presence of CD8+ lymphocytes, which negatively affect bone regeneration. This study aims to investigate whether the negative impact of BMC on bone healing in this technique is due to the CD8+ cell population. Materials and methods: A 5 mm femoral defect was created in 25 male Sprague-Dawley rats, divided into three groups (G1-G3). BMC were isolated from syngenic donor rats, with CD8+ lymphocytes removed magnetically from the BMC fraction in one group. The defects were filled with bone chips and wrapped with differently treated hADM: G1 received native hADM, G2 received hADM+BMC, and G3 received hADM+BMC-CD8. After 8 weeks, the femurs were evaluated through radiological, biomechanical, and histological examinations. Results: Bone defects and bone mineral density (BMD) were significantly improved in G3 (hADM+BMC-CD8) compared to G2 (hADM+BMC). Bone volume, bone formation, and median bending stiffness were higher in G3. Immunohistological analysis showed a significant decrease in CD8 cell count in G3, with a lower percentage of IFNγ-producing cells compared to G2. Conclusion: Depleting CD8+ cells from BMC before colonizing hADM significantly improved bone healing, likely due to changes in the local mediator environment. This suggests that preoperative colonization with CD8+-depleted BMC could enhance the one-step membrane technique. [ABSTRACT FROM AUTHOR]

A comprehensive understanding of the cardio-spleen-bone marrow immune cell axis is essential for elucidating the alterations occurring during the pathogenesis of diabetes mellitus (DM). This study investigates the dynamics of immune cell kinetics in DM after myocardial infarction (MI) over time. MI was induced in diabetic and healthy control groups using C57BL/N6 mice, with sacrifices occurring at days 1, 3, 7, and 28 post-MI to collect heart, peripheral blood (PB), spleen, and bone marrow (BM) samples. Cell suspensions from each organ were isolated and analyzed via flow cytometry. Additionally, the endothelial progenitor cell-colony-forming assay (EPC-CFA) was performed using mononuclear cells derived from BM, PB, and the spleen. The results indicated that, despite normal production in BM and the spleen, CD45+ cells were lower in the PB of DM mice at days 1 to 3. Further analysis revealed a reduction in total and pro-inflammatory neutrophils (N1s) in PB at days 1 to 3 and in the spleen at days 3 to 7 in DM mice, suggesting that DM-induced alterations in splenic neutrophils fail to meet the demand in PB and ischemic tissues. Infiltrating macrophages (total, M1, M2) were reduced at day 3 in the DM-ischemic heart, with total and M1 (days 1–3) and M2 (days 3–7) macrophages being significantly decreased in DM-PB compared to controls, indicating impaired macrophage recruitment and polarization in DM. Myeloid dendritic cells (mDCs) in the heart were higher from days 1 to 7, which corresponded with the enhanced recruitment of CD8+ cells from days 1 to 28 in the DM-infarcted myocardium. Total CD4+ cells decreased in DM-PB at days 1 to 3, suggesting a delayed adaptive immune response to MI. B cells were reduced in PB at days 1 to 3, in myocardium at day 3, and in the spleen at day 7, indicating compromised mobilization from BM. EPC-CFA results showed a marked decrease in definitive EPC colonies in the spleen and BM from days 1 to 28 in DM mice compared to controls in vitro, highlighting that DM severely impairs EPC colony-forming activity by limiting the differentiation of EPCs from primitive to definitive forms. Taking together, this study underscores significant disruptions in the cardio-spleen-bone marrow immune cell axis following MI in DM, revealing delayed innate and adaptive immune responses along with impaired EPC differentiation. [ABSTRACT FROM AUTHOR]

There is increasing evidence that thirdhand exposure to e-cigarette vapor (e-vapor) can have detrimental effects on the lungs. However, whether maternal exposure during pregnancy results in harmful changes to the offspring is unknown. Using two different e-cigarette settings (low vs. high power), BALB/c mice were subjected to thirdhand e-vapor (e-vapor deposited onto towels, towels changed daily) in the absence or presence of nicotine, before, during, and after pregnancy. Male adult offspring were then infected with mouse-adapted influenza A virus (A/PR/8/34 H1N1; Flu) and lung and bone marrow immune cell responses were assessed 7 days postinfection. Maternal thirdhand exposure to low-power (MLP) or high-power (MHP) e-vapor with nicotine (MLP + NIC and MHP + NIC, respectively) increased the percentage of lung immune cells and neutrophils in the bone marrow. Interestingly, Flu-infected offspring from MLP + NIC and MHP + NIC groups had lower percentages of lung alveolar macrophages and more pronounced increases in neutrophils in the bone marrow, when compared with offspring from MSham Flu controls. Flu infection also decreased the percentage of lung CD4+ T cells and increased the percentage of lung CD8+ T cells, irrespective of maternal exposure (MLP −/+ NIC and MHP −/+ NIC). Significantly, both MLP + NIC and MHP + NIC resulted in blunted activation of lung CD4+ T cells, but only MLP + NIC caused blunted activation of lung CD8+ T cells. Together, we show for the first time that maternal thirdhand exposure to e-vapor results in significant, long-lived effects on lung and bone marrow immune cell responses in offspring at baseline and response to Flu infection. NEW & NOTEWORTHY: Maternal exposure to environmental residues of e-cigarette use has significant effects on immune cell responses in the lungs and bone marrow of offspring at both baseline and in response to influenza A virus (Flu) infection. [ABSTRACT FROM AUTHOR]

Activation-induced cytidine deaminase (AID, encoded by Aicda) plays a key role in somatic hypermutation and class switch recombination in germinal center B cells. However, off-target effects of AID are implicated in human leukemia and lymphoma. A mouse model of precursor B cell acute lymphoblastic leukemia driven by deletion of the related transcription factors PU.1 and Spi-B revealed C->T transition mutations compatible with being induced by AID. Therefore, we hypothesized that PU.1 negatively regulates Aicda during B cell development. Aicda mRNA transcript levels were increased in leukemia cells and bone marrow pre-B cells lacking PU.1 and/or Spi-B, relative to wild type cells. Using chromatin immunoprecipitation, PU.1 was found to interact with a negative regulatory region (R2–1) within the first intron of Aicda. CRISPR-Cas9-induced mutagenesis of R2–1 in cultured pre-B cells resulted in upregulation of Aicda in response to lipopolysaccharide stimulation. Mutation of the PU.1 interaction site and neighboring sequences resulted in reduced repressive ability of R2–1 in transient transfection analysis followed by luciferase assays. These results show that a PU.1-interacting intronic region negatively regulates Aicda transcription in developing B cells. • Aicda transcription is dysregulated in the absence of PU.1. • The transcription factor PU.1 interacts with the first intron of Aicda. • CRISPR-Cas9 mutation of a PU.1 site in Aicda intron 1 dysregulates transcription. • A PU.1-interacting site in intron 1 is a negative regulator of Aicda transcription. [ABSTRACT FROM AUTHOR]

Avian species have played a pivotal role in developmental hematopoiesis research, leading to numerous critical discoveries. Avian influenza, particularly the H5N1 strain, poses a significant threat to poultry and has zoonotic potential for humans. Infections often result in abnormal hematologic profiles, highlighting the complex interplay between avian diseases and hematopoiesis. Many avian diseases can suppress immune cells in the bone marrow (BM), impacting immune responses. Studying hematopoietic stem cells (HSCs) in avian BM is crucial for understanding these processes and developing effective vaccines and protection strategies for both avian and human health. This study adapted methods from mouse studies to isolate avian HSCs as Lineage-negative (Lin-) cells. These isolated cells were further identified as Lin-Sca1+c-Kit+ (LSK) and were found to be more prevalent than in control groups. RT-PCR analyses were conducted, showing that genes like MEIS1 and TSC1 were upregulated, while SIRT1, FOXO1, and AHR were downregulated in these stem cells. Screening for LSK markers revealed ten unique surface antigens in the Sca1+c-Kit+ cell populations, including highly enriched antigens such as CD178, CD227, and CD184. Additionally, studies on quail HSCs demonstrated that similar labeling techniques were effective in quail BM. The research demonstrated that the identification of avian HSC-specific surface antigens provides valuable insights into the pathogenesis of avian influenza and other diseases, enhancing our understanding of how these diseases suppress HSC function. Notably, the upregulation of MEIS1 and TSC1 genes in LSK cells underscores their critical roles in regulating hematopoietic processes. Conversely, the downregulation of SIRT1, FOXO1, and AHR genes provides important clues about their roles in differentiation and immune response mechanisms. The findings of this study deepen our understanding of the effects of avian diseases on the immune system by identifying surface markers specific to avian HSCs. The suppression of HSC function by pathogens such as influenza highlights the importance of understanding these cells in developing targeted vaccines. These results represent a significant step towards improving global health security by mitigating risks associated with avian pathogens. [ABSTRACT FROM AUTHOR]

Among blood cancers, multiple myeloma (MM) represents the second most common neoplasm and is characterized by the accumulation and proliferation of monoclonal plasma cells within the bone marrow. Despite the last few decades being characterized by the development of different therapeutic strategies against MM, at present such disease is still considered incurable. Although MM is highly heterogeneous in terms of genetic and molecular subtypes, about 67% of MM cases are associated with abnormal activity of the transcription factor c-Myc, which has so far revealed a protein extremely difficult to target. We have recently demonstrated that activation of fibroblast growth factor (FGF) signaling protects MM cells from oxidative stress-induced apoptosis by stabilizing the oncoprotein c-Myc. Accordingly, secretion of FGF ligands and autocrine activation of FGF receptors (FGFR) is observed in MM cells and FGFR3 genomic alterations represent some 15–20% MM cases and are associated with poor outcome. Thus, FGF/FGFR blockade may represent a promising strategy to indirectly target c-Myc in MM. On this basis, the present review aims at providing an overview of recently explored connections between the FGF/FGFR system and c-Myc oncoprotein, sustaining the therapeutic potential of targeting the FGF/FGFR/c-Myc axis in MM by using inhibitors targeting FGF ligands or FGF receptors. Importantly, the provided findings may represent the rationale for using FDA approved FGFR TK inhibitors (i.e. Pemigatinib, Futibatinib, Erdafitinib) for the treatment of MM patients presenting with an aberrant activation of this axis. [ABSTRACT FROM AUTHOR]

Ex vivo production of red blood cells (RBCs) represents a promising alternative for transfusion medicine. Several strategies have been described to generate erythroid cell lines from different sources, including embryonic, induced pluripotent, and hematopoietic stem cells. All these approaches have in common that they require elaborate differentiation cultures whereas the yield of enucleated RBCs is inefficient. We generated a human immortalized adult erythroid progenitor cell line derived from bone marrow CD71-positive erythroid progenitor cells (immortalized bone marrow erythroid progenitor adult, or imBMEP-A) by an inducible expression system, to shorten differentiation culture necessary for terminal erythroid differentiation. It is the first erythroid cell line that is generated from direct reticulocyte progenitors and demonstrates robust hemoglobin production in the immortalized state. Morphologic analysis of the immortalized cells showed that the preferred cell type of the imBMEP-A line corresponds to hemoglobin-producing basophilic erythroblasts. In addition, we were able to generate a stable cell line from a single cell clone with the triple knockout of RhAG, RhDCE and KELL. After removal of doxycycline, part of the cells differentiated into normoblasts and reticulocytes within 5–7 days. Our results demonstrate that the imBMEP-A cell line can serve as a stable and straightforward modifiable platform for RBC engineering in the future. [Display omitted] [ABSTRACT FROM AUTHOR]

Pre-transplant lung dysfunction is known to be a risk factor for non-relapse mortality (NRM) after allogeneic hematopoietic cell transplantation (allo-HCT). It is unclear which cell source gives better outcomes for patients with pulmonary dysfunction. We analyzed 3289 adult patients with standard-risk disease who had received HLA-matched allo-HCT, and compared outcomes between those who received peripheral blood stem cell (PBSC) vs. bone marrow (BM) in two cohorts based on the presence of a lung score by the Hematopoietic Cell Transplantation-specific Comorbidity Index (HCT-CI): the Lung-scored (LS) and non-LS cohorts. In the LS cohort, the 2-year overall survival (OS) in the BM group tended to be higher than that in the PBSC group (72.4% vs. 61.4%; P = 0.044). In the non-LS cohort, there was no significant difference between the two groups (71.7% vs. 73.2%; P = 0.13). Multivariate analyses confirmed that PBSC was significantly associated with inferior OS in the LS cohort (hazard ratio [HR], 1.66; 95% CI, 1.09-2.54; P = 0.019). On the other hand, the cell source did not affect OS in the non-LS cohort (HR, 0.92; 95% CI, 0.76-1.12; P = 0.41). We found that PBSC was associated with an increased risk of NRM in the LS cohort (HR, 2.17; 95% CI, 1.16-4.05; P = 0.016), while the cell source did not significantly affect NRM in the non-LS cohort. PBSC was not identified as a risk factor for relapse in either cohort. Our results suggest that BM might be beneficial for recipients with lung dysfunction in HLA-matched allo-HCT. [Display omitted] • The use of PBSC was significantly associated with inferior OS and NRM in HCT-CI Lung-scored patients. • Patients in the HCT-CI Lung-scored cohort who received PBSC experienced a higher incidence of non-pulmonary infection-related deaths than those who received BM. [ABSTRACT FROM AUTHOR]

The one-year survival rate for patients experiencing a relapse of B-cell acute lymphocytic leukemia (B-ALL) following hematopoietic stem cell transplantation (HSCT) is approximately 30%. Patients experiencing a relapse after allogeneic HSCT frequently encounter difficulties in obtaining autologous CAR-T products. We conducted a study involving 14 patients who received donor-derived CAR-T therapy for relapsed B-ALL following HSCT between August 2019 and May 2023 in our center. The results revealed a CR/CRi rate of 78.6% (11/14), a GVHD rate of 21.4% (3/14), and a 1-year overall survival (OS) rate of 56%. Decreased bone marrow donor cell chimerism in 9 patients recovered after CAR-T therapy. The main causes of death were disease progression and infection. Further analysis showed that GVHD (HR 7.224, 95% CI 1.42–36.82, P = 0.017) and platelet recovery at 30 days (HR 6.807, 95% CI 1.61–28.83, P = 0.009) are significantly associated with OS after CAR-T therapy. Based on the findings, we conclude that donor-derived CAR-T cells are effective in treating relapsed B-ALL patients following HSCT. Additionally, GVHD and poor platelet recovery impact OS, but further verification with a larger sample size is needed. [ABSTRACT FROM AUTHOR]

BMI1 polycomb ring finger proto-oncogene (BMI1) is involved in the pathogenesis of different cancers, including acute myeloid leukemia (AML). However, the role of the circular RNA of BMI1 (circBMI1) has not been studied. Our study aimed to investigate the role and mechanism of circBMI1 in AML. circBMI1 was significantly decreased in bone marrow mononuclear cells aspirated from patients with AML. Receiver operating characteristic curve analysis showed that circBMI1 could distinguish patients with AML from controls. By overexpressing and knocking down circBMI1 in HL-60 cells, we found that circBMI1 inhibited cell proliferation, promoted apoptosis, and increased chemotherapeutic drug sensitivity in AML. Experiments using severe combined immune-deficient mice and circBMI1 transgenic mice showed that mice with circBMI1 overexpression had lower white blood cell counts, which suggested less severe AML invasion. RNA immunoprecipitation and dual-luciferase reporter assay revealed binding sites among circBMI1 , miR-338-5p , and inhibitor of DNA-binding protein 4 (ID4). Rescue experiments proved that circBMI1 inhibited AML progression by binding to miR-338-5p , which affected the expression of ID4. By coculturing exosomes extracted from circBMI1 -HL-60 and small interfering circBMI1 -HL-60 cells with HL-60 cells, we found that exosomes from circBMI1 -HL-60 cells showed tumor-suppressive effects, namely inhibiting HL-60 proliferation, promoting apoptosis, and increasing chemotherapeutic drug sensitivity. Exosomes from small interfering circBMI1 -HL-60 cells showed the opposite effects. circBMI1 may act as an exosome-dependent tumor inhibitor. circBMI1 , a potential biomarker for clinical diagnosis, acts as a tumor suppressor in AML by regulating miR-338-5p / ID4 and might affect the pathogenesis of AML by exosome secretion. [ABSTRACT FROM AUTHOR]

Background: Achieving first complete remission with induction chemotherapy (ICT) for acute myeloid leukemia (AML) correlates with patient's prognosis. This study aimed to determine the correlation between oxidative stress and the outcome of ICT in AML patients. Methods: A total of 195 AML patients underwent initial ICT at the Longyan First Affiliated Hospital of Fujian Medical University from 06-11-2018 to 12-30-2023. Three weeks after ICT, patients were divided into two groups, CR (complete remission) and PR (partial remission), by detecting blood parameters and bone marrow cells. Serum oxidative stress-related factors, malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), total antioxidant capacity (T-AOC), and growth/differentiation factor-15 (GDF15) activities or levels were measured to assess the diagnostic value of these factors as a means of diagnosing the efficacy of ICT in patients. Factors affecting PR after initial ICT were analyzed. Results: Patients in the PR group had higher levels of oxidative stress three weeks after initial ICT. Compared with the CR group, patients in the PR group had elevated levels of MDA and GDF15 and reduced activities of SOD, GSH-Px, and T-AOC. Serum MDA levels (AUC 0.709; 95% CI. 0.618 - 0.781) and the combination of multiple indicators (AUC 0.791; 95% CI. 704 - 0.851) had diagnostic value for the efficacy of AML patients undergoing ICT. Serum MDA and GDF15 exceeding cutoff values were risk factors for PR in AML patients undergoing ICT, as were serum SOD and T-AOC below cutoff values. Preoperative malnutrition was associated with PR in patients. Conclusions: Serum oxidative stress-related factors in AML patients are helpful in detecting the efficacy of ICT. Oxidative stress in response to ICT is useful for characterizing the efficacy in AML patients after ICT. [ABSTRACT FROM AUTHOR]

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VEXAS syndrome is a newly described autoinflammatory entity characterized by somatic mutations in the UBA1 X-linked gene in hematopoietic progenitor cells. Several studies have demonstrated that the presence of vacuoles in progenitor cells from bone marrow aspirates is a hallmark finding for this syndrome. Therefore, this study aimed to characterize leukocytes from VEXAS patients versus patients with ANCA-associated vasculitis (AAV), familial Mediterranean fever (FMF), and healthy donors (HD) to define a specific cytological pattern that can support VEXAS diagnosis. Twelve VEXAS patients were included in the study. Blood samples from FMF (n = 16), AAV (n = 16) and HDs (n = 20) acted as controls. May-Grünwald Giemsa (MGG) staining was used for studying cellular morphology, including cytoplasm, granules, and vacuoles and to perform a cytogenic evaluation of leucocytes. Plasma IL-1b, IL-1a, TNFa, IL-18 and IL-8 were measured using ELISA assay. The cytological analysis from blood smears confirmed the presence of immature neutrophils in VEXAS patients. We found a greater number of vacuoles in VEXAS patients vs. FMF, AAV and HD. Micronuclei (MNi) and cell death rate were higher in VEXAS patients vs. HD. Cell death correlated with IL-1b and IL-8 levels. MNi were positively associated with IL-8 and IL-1b levels, and with the percentage of immature neutrophils and vacuoles. In conclusion, our findings suggested that cytological test may be supportive for VEXAS diagnosis, despite genetical analysis is mandatory for confirming the disease. Finally, we identified several cytological hallmarks that may distinguish the VEXAS “cytotype” not only from HD but also from other inflammatory diseases. [ABSTRACT FROM AUTHOR]

Osteoblasts are mainly derived from mesenchymal stem cells in the bone marrow. These stem cells can differentiate into osteoblasts, which have the functions of secreting bone matrix, promoting bone formation, and participating in bone remodeling. The abnormality of osteoblasts can cause a variety of bone-related diseases, including osteoporosis, delayed fracture healing, and skeletal deformities. In recent years, with the side effects caused by the application of PTH drugs, biphosphonate drugs, and calmodulin drugs, people have carried out more in-depth research on the mechanism of osteoblast differentiation, and are actively looking for natural compounds for the treatment of osteoporosis. The Wnt/β-catenin signaling pathway is considered to be one of the important pathways of osteoblast differentiation, and has become an important target for the treatment of osteoporosis. The Wnt/β-catenin signaling pathway, whether its activation is enhanced or its expression is weakened, will cause a variety of diseases including tumors. This review will summarize the effect of Wnt/β-catenin signaling pathway on osteoblast differentiation and the correlation between the related proteins in the pathway and human diseases. At the same time, the latest research progress of natural compounds targeting Wnt/β-catenin signaling pathway against osteoporosis is summarized. [ABSTRACT FROM AUTHOR]

Both cell-intrinsic and niche-derived, cell-extrinsic cues drive the specification of hematopoietic multipotent progenitors (MPPs) in the bone marrow, which comprise multipotent MPP1 cells and lineage-restricted MPP2, MPP3, and MPP4 subsets. Patients with WHIM syndrome, a rare congenital immunodeficiency caused by mutations that prevent desensitization of the chemokine receptor CXCR4, have an excess of myeloid cells in the bone marrow. Here, we investigated the effects of increased CXCR4 signaling on the localization and fate of MPPs. Knock-in mice bearing a WHIM syndrome–associated CXCR4 mutation (CXCR41013) phenocopied the myeloid skewing of bone marrow in patients. Whereas MPP4 cells in wild-type mice differentiated into lymphoid cells, MPP4s in CXCR41013 knock-in mice differentiated into myeloid cells. This myeloid rewiring of MPP4s in CXCR41013 knock-in mice was associated with enhanced signaling mediated by the kinase mTOR and increased oxidative phosphorylation (OXPHOS). MPP4s also localized further from arterioles in the bone marrow of knock-in mice compared with wild-type mice, suggesting that the loss of extrinsic cues from the perivascular niche may also contribute to their myeloid skewing. Chronic treatment with the CXCR4 antagonist AMD3100 or the mTOR inhibitor rapamycin restored the lymphoid potential of MPP4s in knock-in mice. Thus, CXCR4 desensitization drives the lymphoid potential of MPP4 cells by dampening the mTOR-dependent metabolic changes that promote myeloid differentiation. Editor's summary: Truncations of the chemokine receptor CXCR4 prevent its internalization and cause WHIM syndrome, an inherited immunodeficiency characterized by increased numbers of myeloid cells in the bone marrow. In a mouse model of WHIM syndrome, Rondeau et al. found that a subset of multipotent progenitor cells that normally adopt a lymphoid fate were reprogrammed to instead adopt a myeloid fate. Impaired Cxcr4 desensitization in these cells caused their mislocalization within the bone marrow and an increase in mTOR signaling that metabolically rewired them toward a myeloid fate. These findings show that Cxcr4 promotes an mTOR-dependent metabolic program that confers myeloid identity. —Annalisa M. VanHook [ABSTRACT FROM AUTHOR]

Background: Brain microglia and infiltrating monocyte-derived macrophages are vital in preserving blood vessel integrity after stroke. Understanding mechanisms that induce immune cells to adopt vascular-protective phenotypes may hasten the development of stroke treatments. IL-33 is a potent chemokine released from damaged cells, such as CNS glia after stroke. The activation of IL-33/ST2 signaling has been shown to promote neuronal viability and white matter integrity after ischemic stroke. The impact of IL-33/ST2 on blood-brain barrier (BBB) integrity, however, remains unknown. The current study fills this gap and reveals a critical role of IL-33/ST2 signaling in macrophage-mediated BBB protection after stroke. Methods: Transient middle cerebral artery occlusion (tMCAO) was performed to induce ischemic stroke in wildtype (WT) versus ST2 knockout (KO) male mice. IL-33 was applied intranasally to tMCAO mice with or without dietary PLX5622 to deplete microglia/macrophages. ST2 KO versus WT bone marrow or macrophage cell transplantations were used to test the involvement of ST2+ macrophages in BBB integrity. Macrophages were cocultured in transwells with brain endothelial cells (ECs) after oxygen-glucose deprivation (OGD) to test potential direct effects of IL33-treated macrophages on the BBB in vitro. Results: The ST2 receptor was expressed in brain ECs, microglia, and infiltrating macrophages. Global KO of ST2 led to more IgG extravasation and loss of ZO-1 in cerebral microvessels 3 days post-tMCAO. Intranasal IL-33 administration reduced BBB leakage and infarct severity in microglia/macrophage competent mice, but not in microglia/macrophage depleted mice. Worse BBB injury was observed after tMCAO in chimeric WT mice reconstituted with ST2 KO bone marrow, and in WT mice whose monocytes were replaced by ST2 KO monocytes. Macrophages treated with IL-33 reduced in vitro barrier leakage and maintained tight junction integrity after OGD. In contrast, IL-33 exerted minimal direct effects on the endothelial barrier in the absence of macrophages. IL-33-treated macrophages demonstrated transcriptional upregulation of an array of protective factors, suggesting a shift towards favorable phenotypes. Conclusion: Our results demonstrate that early-stage IL-33/ST2 signaling in infiltrating macrophages reduces the extent of acute BBB disruption after stroke. Intranasal IL-33 administration may represent a new strategy to reduce BBB leakage and infarct severity. [ABSTRACT FROM AUTHOR]

Human bone marrow mesenchymal stem cells (hBMSCs) are adult stem cells residing in the bone marrow, characterized by their capacity for multi-directional differentiation, self-renewal, migration, and engraftment. Serving as seed cells, BMSCs play a pivotal role in the regeneration of bone defects. Hence, investigating the transcription factors and signaling pathways involved in the regulation of osteogenic differentiation in BMSCs holds significant importance. Recent research has unveiled that certain circular RNAs (circRNAs) can function as molecular sponges, influencing the osteogenic differentiation process of mesenchymal stem cells. However, many circRNAs remain undiscovered, and their precise mechanisms remain elusive. Therefore, the objective of this study is to construct an osteogenic differentiation-related circRNA-miRNA-mRNA network in hBMSCs. Subsequently, through bioinformatics analysis, we constructed a ceRNA network related to the osteogenic differentiation ability of hBMSCs, comprising 22 circRNAs, 17 miRNAs, and 15 mRNAs. The potential circRNA-miRNA-mRNA axes, including the role of hsa_circ_0001600 in promoting the osteogenic differentiation of hBMSCs through the targeted regulation of hsa-miR-542-3p, were validated through in vitro experiments. [ABSTRACT FROM AUTHOR]

Bone marrow and teeth contain mesenchymal stem cells (MSCs) that could be used for cell-based regenerative therapies. MSCs from these two tissues represent heterogeneous cell populations with varying degrees of lineage commitment. Although human bone marrow stem cells (hBMSCs) and human dental pulp stem cells (hDPSCs) have been extensively studied, it is not yet fully defined if their adipogenic potential differs. Therefore, in this study, we compared the in vitro adipogenic differentiation potential of hDPSCs and hBMSCs. Both cell populations were cultured in adipogenic differentiation media, followed by specific lipid droplet staining to visualise cytodifferentiation. The in vitro differentiation assays were complemented with the expression of specific genes for adipogenesis and osteogenesis–dentinogenesis, as well as for genes involved in the Wnt and Notch signalling pathways. Our findings showed that hBMSCs formed adipocytes containing numerous and large lipid vesicles. In contrast to hBMSCs, hDPSCs did not acquire the typical adipocyte morphology and formed fewer lipid droplets of small size. Regarding the gene expression, cultured hBMSCs upregulated the expression of adipogenic-specific genes (e.g., PPARγ2, LPL, ADIPONECTIN). Furthermore, in these cells most Wnt pathway genes were downregulated, while the expression of NOTCH pathway genes (e.g., NOTCH1, NOTCH3, JAGGED1, HES5, HEY2) was upregulated. hDPSCs retained their osteogenic/dentinogenic molecular profile (e.g., RUNX2, ALP, COLIA1) and upregulated the WNT-specific genes but not the NOTCH pathway genes. Taken together, our in vitro findings demonstrate that hDPSCs are not entirely committed to the adipogenic fate, in contrast to the hBMSCs, which are more effective to fully differentiate into adipocytes. [ABSTRACT FROM AUTHOR]

The serine/threonine/tyrosine kinase 1 (STYK1) is a receptor protein-tyrosine kinase (RPTK)-like molecule that is detected in several human organs. STYK1 plays an important role in promoting tumorigenesis and metastasis in various cancers. By analyzing the expression of RTKs in immune cells in the database of 2013 Immunological Genome Project, we found that STYK1 was principally expressed in NK cells. In order to investigate the function of STYK1, we used CRISPR/Cas9 technology to generate STYK1-deleted mice, we found STYK1 deletion mice have normal number, development, and function of NK cells in spleen and bone marrow in tumor-free resting state. To examine the tumor surveillance of STYK1 in vivo, we utilized a variety of tumor models, including NK cell-specific target cell (ß2M and RMA-S) clearance experiments in vivo, subcutaneous and intravenous injection of B16F10 melanoma model, and the spontaneous breast cancer model MMTV-PyMT. Surprisingly, we discovered that deletion of the oncogenic STYK1 promoted the four-model tumor progression, and we observed a reduction of NK cell accumulation in the tumor tissues of STYK1 deletion mice compared to WT mice. In order to study the mechanism of STYK1 in NK, RNA sequence of STYK1−/− and WT NK have unveiled a disparity in the signaling pathways linked to migration and adhesion in STYK1−/− NK cells. Further analysis of chemokine receptors associated with NK cell migration revealed that STYK1-deficient NK cells exhibited a significant reduction in CCR2 expression. The STYK1 expression was negatively associated with tumor progression in glioma patients. Overall, our study found the expression of STYK1 in NK cell mediates NK cell anti-tumor response through regulating CCR2 and infiltrating into tumor tissue. [ABSTRACT FROM AUTHOR]

BACKGROUND. Donor cell engraftment is a prerequisite of successful allogeneic hematopoietic stem cell transplantation. Based on peripheral blood analyses, it is characterized by early myeloid recovery and T and B cell lymphopenia. However, cellular networks associated with bone marrow engraftment of allogeneic human cells have been poorly described. METHODS. Mass cytometry and CITE-Seq analyses were performed on bone marrow cells 3 months after transplantation in patients with acute myelogenous leukemia. RESULTS. Mass cytometric analyses in 26 patients and 20 healthy controls disclosed profound alterations in myeloid and B cell progenitors, with a shift toward terminal myeloid differentiation and decreased B cell progenitors. Unsupervised analysis separated recipients into 2 groups, one of them being driven by previous graft-versus-host disease (R2 patients). We then used single-cell CITE-Seq to decipher engraftment, which resolved 36 clusters, encompassing all bone marrow cellular components. Hematopoiesis in transplant recipients was sustained by committed myeloid and erythroid progenitors in a setting of monocyte-, NK cell-, and T cell-mediated inflammation. Gene expression revealed major pathways in transplant recipients, namely, TNF-α signaling via NF-κB and the IFN-γ response. The hallmark of allograft rejection was consistently found in clusters from transplant recipients, especially in R2 recipients. CONCLUSION. Bone marrow cell engraftment of allogeneic donor cells is characterized by a state of emergency hematopoiesis in the setting of an allogeneic response driving inflammation. FUNDING. This study was supported by the French National Cancer Institute (Institut National du Cancer; PLBIO19-239) and by an unrestricted research grant by Alexion Pharmaceuticals. [ABSTRACT FROM AUTHOR]

Myeloproliferative neoplasms (MPNs) are characterized by an increased production of blood cells due to the acquisition of mutations such as JAK2V617F. TGF‐β, whose secretion is increased in MPN patients, is known to negatively regulate haematopoietic stem cell (HSC) proliferation. Using an isogenic JAK2V617F or JAK2 wild‐type UT‐7 cell line we observed that JAK2V617F cells resist to TGF‐β antiproliferative activity. Although TGF‐β receptors and SMAD2/3 expressions are similar in both cell types, TGF‐β‐induced phosphorylation of SMAD2/3 is reduced in UT‐7 JAK2V617F cells compared with JAK2 WT cells. We confirmed that JAK2V617F mutated cells are resistant to the antiproliferative effect of TGF‐β in a competitive assay as we observed a positive selection of JAK2V617F cells when exposed to TGF‐β. Using cell lines, CD34‐positive cells from MPN patients and bone marrow cells from JAK2V617F knock‐in mice we identified a down regulation of the SHP‐1 phosphatase, which is required for the regulation of HSC quiescence by TGF‐β. The transduction of SHP‐1 cDNA (but not a phosphatase inactive cDNA) restores the antiproliferative effect of TGF‐β in JAK2V617F mutated cells. Finally, SC‐1, a known agonist of SHP‐1, antagonized the selection of JAK2V617F mutated cells in the presence of TGF‐β. In conclusion, we show a JAK2‐dependent down regulation of SHP‐1 in MPN patients' cells which is related to their resistance to the antiproliferative effect of TGF‐β. This may participate in the clonal selection of cancer cells in MPNs. [ABSTRACT FROM AUTHOR]

AbstractFDA approved agents for the treatment of chronic GVHD including ruxolitinib and belumosudil are effective steroid-sparing agents, with overall response rates (ORR) of 76% and 65% respectively. Ruxolitinib and belumosudil are well tolerated with different primary targets. Little data is available on the use of combination ruxolitinib and belumosudil. This is a single center, retrospective analysis of 20 treatment-refractory patients with chronic GVHD treated with combination ruxolitinib and belumosudil. The ORR including complete response (CR) and partial response (PR) at any time was 55% (11/20). Among responding patients, other immunosuppressive agents were tapered or discontinued in all patients. None of the patients developed EBV or CMV reactivation requiring treatment. 4 patients (20%) developed pneumonia and 2 patients (10%) developed viral URI. Cytopenias were not exacerbated. No patients had graft failure or relapsed disease. The combination is tolerable, delays the need for alternative therapies, and facilitates tapering of corticosteroids. [ABSTRACT FROM AUTHOR]

Acute myeloid leukemia (AML) is a malignant tumor of the hematological system. Because of its characteristics of recurrence, refractory and chemoresistance, new therapeutic targets need to be identified. Adhesion and proliferation are characteristics of AML cells, and critical steps in inducing chemotherapy resistance. In this study, we reported that UNC5B inhibits AML cell bone marrow adhesion, inhibits AML cell proliferation and increases sensitivity to chemotherapy. Mechanistically, RNA sequencing (RNA-seq) and experimental results revealed that overexpression of UNC5B inhibits adhesion and proliferation signaling pathways and inhibits the expression of MPZL1, CLDN23, IGF2 and WNT7B. In conclusion, our findings suggest that UNC5B serves as a prognostic indicator and a potential therapeutic target for AML. [ABSTRACT FROM AUTHOR]

Myeloproliferative neoplasms are stem cell–driven cancers associated with a large burden of morbidity and mortality. Most patients present with early-stage disease, but a substantial proportion progress to myelofibrosis or secondary leukemia, advanced cancers with a poor prognosis and high symptom burden. Currently, it remains difficult to predict progression, and therapies that reliably prevent or reverse fibrosis are lacking. A major bottleneck to the discovery of disease-modifying therapies has been an incomplete understanding of the interplay between perturbed cellular and molecular states. Several cell types have individually been implicated, but a comprehensive analysis of myelofibrotic bone marrow is lacking. We therefore mapped the cross-talk between bone marrow cell types in myelofibrotic bone marrow. We found that inflammation and fibrosis are orchestrated by a "quartet" of immune and stromal cell lineages, with basophils and mast cells creating a TNF signaling hub, communicating with megakaryocytes, mesenchymal stromal cells, and proinflammatory fibroblasts. We identified the β-galactoside–binding protein galectin-1 as a biomarker of progression to myelofibrosis and poor survival in multiple patient cohorts and as a promising therapeutic target, with reduced myeloproliferation and fibrosis in vitro and in vivo and improved survival after galectin-1 inhibition. In human bone marrow organoids, TNF increased galectin-1 expression, suggesting a feedback loop wherein the proinflammatory myeloproliferative neoplasm clone creates a self-reinforcing niche, fueling progression to advanced disease. This study provides a resource for studying hematopoietic cell–niche interactions, with relevance for cancer-associated inflammation and disorders of tissue fibrosis. Editor's summary: Myeloproliferative neoplasms can transition to advanced cancers with poor prognosis. Predicting progression and reversing the associated myelofibrosis remain difficult. Li, Colombo, and Wang et al. present a mouse cancer-stroma interactome for myelofibrosis and show that galectin-1 is a potential inflammation-related target for treating disease. Mesenchymal stem cells, eosinophils, basophils, and mast cells were each implicated in an inflammatory niche that drove myelofibrosis progression. Inhibiting galectin-1 with a monoclonal antibody in a mouse model of myeloproliferative neoplasm decreased fibrosis and cell proliferation and had a beneficial effect on survival. Galectin-1 was associated with myelofibrosis and poor survival in multiple human cohorts. These results suggest that galectin-1 may be a target to alter the inflammatory niche and to reduce fibrosis in myeloproliferative neoplasms. —Brandon Berry [ABSTRACT FROM AUTHOR]

Certain immune cells, including neutrophils, macrophages, dendritic cells, B cells, Breg cells, CD4+ T cells, CD8+ T cells, and Treg cells, establish enduring residency within the bone marrow. Their distinctive interactions with hematopoiesis and the bone marrow microenvironment are becoming increasingly recognized alongside their multifaceted immune functions. These cells play a dual role in shaping hematopoiesis. They directly influence the quiescence, self-renewal, and multi-lineage differentiation of hematopoietic stem and progenitor cells through either direct cell-to-cell interactions or the secretion of various factors known for their immunological functions. Additionally, they actively engage with the cellular constituents of the bone marrow niche, particularly mesenchymal stem cells, endothelial cells, osteoblasts, and osteoclasts, to promote their survival and contribute to tissue repair, thereby fostering a supportive environment for hematopoietic stem and progenitor cells. Importantly, these bone marrow immune cells function synergistically, both locally and functionally, rather than in isolation. In summary, immune cells residing in the bone marrow are pivotal components of a sophisticated network of regulating hematopoiesis. [ABSTRACT FROM AUTHOR]

Nephrotic syndrome is characterized by the leakage of protein from the blood into the urine along with the triad of proteinuria, albuminuria, and peripheral edema. Loss of protein leads to the loss of immunoglobulin and complements. X-linked agammaglobulinemia (XLA), or Bruton disease, is a primary immunodeficiency disease caused by a defect in the development of B cells in the bone marrow and a low serum level of immunoglobulins. The present case involves a 12-yearold boy with nephrotic syndrome, osteomyelitis, and recurrent infections. We discovered that he had XLA. This report underscores the importance of considering inborn errors of immunity in cases of protein loss, such as nephrotic syndrome. [ABSTRACT FROM AUTHOR]

Introduction: Chronic lymphocytic leukemia (CLL) is the most common type of leukemia in the Western countries and is very rare in Asia. Methods: Peripheral blood or bone marrow mononuclear cells obtained at initial diagnosis from 215 patients with CLL were analyzed by using next-generation sequencing to investigate the ethnic differences in genetic abnormalities. Results: Whole-genome sequencing and whole-exome sequencing analyses on 30 cases showed that 9 genes, including IGLL5, MYD88, TCHH, DSCAM, AXDND1, BICRA, KMT2D, MYT1L, and RBM43, were more frequently mutated in our Taiwanese cohort compared with those of the Western cohorts. IGLL5, MYD88, and KMT2D genes were further analyzed by targeted sequencing in another 185 CLL patients, unraveling frequencies of 29.3%, 20.9%, and 15.0%, respectively. The most frequent positional mutation of MYD88 was V217F (26/45, 57.8%), followed by L265P (9/45, 20.0%). MYD88 mutations were significantly associated with IGLL5 mutations (p = 0.0004), mutated IGHV (p < 0.0001) and 13q deletion (p = 0.0164). CLL patients with co-occurrence of MYD88 mutations with KMT2D or/and IGLL5 mutations were associated with a significantly inferior survival compared to those with MYD88 mutation alone (not reached vs. 131.8 months, p = 0.007). In multivariate analysis, MYD88 mutation without KMT2D or IGLL5 mutations was an independently favorable predictor. Conclusions: IGLL5, MYD88, and KMT2D mutations were enriched in Taiwanese CLL, and co-occurrence of MYD88 mutations with KMT2D or/and IGLL5 mutations was associated with a poorer prognosis. [ABSTRACT FROM AUTHOR]

Pancytopenia is a hematological condition characterized by a decrease in three blood cell lines: erythrocytes, leukocytes, and platelets. This condition is not an independent disease, but a manifestation of various underlying diseases. Pancytopenia can be caused by impaired blood cell production in the bone marrow or increased destruction of blood cells in the periphery. Precise and prompt identification of the etiology is essential, given that pancytopenia can be life-threatening if not treated properly. This study aims to analyze and identify the causes of pancytopenia in patients at Batang Regency Hospital, as well as provide recommendations for appropriate treatment based on the etiology found. The methods used were clinical observation, laboratory examination, and diagnostic imaging in a 58-year-old patient with the main complaint of weakness and a history of pancytopenia. The examination includes a complete blood count, a smear of peripheral blood, and a clinical evaluation. The results showed that the patient had central type pancytopenia, with a suspected etiology of aplastic anemia or myelodysplastic syndrome. Other differential diagnoses include vitamin B12 deficiency. Although a bone marrow biopsy is necessary to confirm the diagnosis, initial therapy with blood transfusions and nutritional improvements has shown an improvement in the patient's condition. The conclusion of this study is the importance of a thorough evaluation to identify the etiology of pancytopenia. Proper treatment should be based on the underlying cause, which will affect the prognosis and prevent recurrence. A comprehensive approach can improve patients' quality of life and reduce the risk of complications. [ABSTRACT FROM AUTHOR]

Bone marrow cellular therapy has undergone a remarkable evolution, significantly impacting the treatment of musculoskeletal disorders. This review traces the historical trajectory from early mythological references to contemporary scientific advancements. The groundbreaking work of Friedenstein in 1968, identifying fibroblast colony-forming cells in bone marrow, laid the foundation for future studies. Caplan's subsequent identification of mesenchymal stem cells (MSCs) in 1991 highlighted their differentiation potential and immunomodulatory properties, establishing them as key players in regenerative medicine. Contemporary research has focused on refining techniques for isolating and applying bone marrow-derived MSCs. These cells have shown promise in treating conditions like osteonecrosis, osteoarthritis, and tendon injuries thanks to their ability to promote tissue repair, modulate immune responses, and enhance angiogenesis. Clinical studies have demonstrated significant improvements in pain relief, functional recovery, and tissue regeneration. Innovations such as the ACH classification system and advancements in bone marrow aspiration methods have standardized practices, improving the consistency and efficacy of these therapies. Recent clinical trials have validated the therapeutic potential of bone marrow-derived products, highlighting their advantages in both surgical and non-surgical applications. Studies have shown that MSCs can reduce inflammation, support bone healing, and enhance cartilage repair. However, challenges remain, including the need for rigorous characterization of cell populations and standardized reporting in clinical trials. Addressing these issues is crucial for advancing the field and ensuring the reliable application of these therapies. Looking ahead, future research should focus on integrating bone marrow-derived products with other regenerative techniques and exploring non-surgical interventions. The continued innovation and refinement of these therapies hold promise for revolutionizing the treatment of musculoskeletal disorders, offering improved patient outcomes, and advancing the boundaries of medical science. [ABSTRACT FROM AUTHOR]

The article discusses the integration of single-cell RNA sequencing data to understand the heterogeneity and function of macrophages in different organs and diseases. It highlights the developmental origins of macrophages, their classification into M1 and M2 types, and the challenges of binary classification in explaining diverse pathophysiological processes. The use of single-cell RNA sequencing technology has revolutionized the study of macrophages, providing insights into their heterogeneity, functional diversity, lineage origin, differentiation trajectories, and cellular communication networks. The article also emphasizes the importance of validating findings from omics data and the advantages and challenges of integrating single-cell research across various organs and diseases. [Extracted from the article]

Assessment of minimal residual disease (MRD) is the most powerful predictor of outcome in B-type acute lymphoblastic leukemia (B-ALL). MRD, defined as the presence of leukemic cells in the blood or bone marrow, is used for the evaluation of therapy efficacy. We report on a microfluidic-based MRD (MF-MRD) assay that allows for frequent evaluation of blood for the presence of circulating leukemia cells (CLCs). The microfluidic chip affinity selects B-lineage cells, including CLCs using anti-CD19 antibodies poised on the wall of the microfluidic chip. Affinity-selected cells are released from the capture surface and can be subjected to immunophenotyping to enumerate the CLCs, perform fluorescence in situ hybridization (FISH), and/or molecular analysis of the CLCs' mRNA/gDNA. During longitudinal testing of 20 patients throughout induction and consolidation therapy, the MF-MRD performed 116 tests, while only 41 were completed with multiparameter flow cytometry (MFC-MRD) using a bone marrow aspirate, as standard-of-care. Overall, 57% MF-MRD tests were MRD(+) as defined by CLC numbers exceeding a threshold of 5 × 10−4%, which was determined to be the limit of quantitation. Above a threshold of 0.01%, MFC-MRD was positive in 34% of patients. The MF offered the advantage of the opportunity for efficiently processing small volumes of blood (2 mL), which is important in the care of pediatric patients, especially infants. The minimally invasive means of blood collection are of high value when treating patients whose MRD is typically tested using an invasive bone marrow biopsy. MF-MRD detection can be useful for stratification of patients into risk groups and monitoring of patient well-being after completion of treatment for early recognition of potential impending disease recurrence. [ABSTRACT FROM AUTHOR]

Hematopoietic stem cells (HSCs) reside in specific microenvironments that facilitate their regulation through both internal mechanisms and external cues. Bone marrow endothelial cells (BMECs), which are found in one of these microenvironments, play a vital role in controlling the self-renewal and differentiation of HSCs during hematological stress. We previously showed that 27-hydroxycholesterol (27HC) administration of exogenous 27HC negatively affected the population of HSCs and progenitor cells by increasing the reactive oxygen species levels in the bone marrow. However, the effect of 27HC on BMECs is unclear. To determine the function of 27HC in BMECs, we employed magnetic-activated cell sorting to isolate CD31+ BMECs and CD31− cells. We demonstrated the effect of 27HC on CD31+ BMECs and HSCs. Treatment with exogenous 27HC led to a decrease in the number of BMECs and reduced the expression of adhesion molecules that are crucial for maintaining HSCs. Our results demonstrate that BMECs are sensitively affected by 27HC and are crucial for HSC survival. [ABSTRACT FROM AUTHOR]

The article discusses the role of the chemokine CCL28 in modulating neutrophil responses during infection with mucosal pathogens. The study found that CCL28 promotes neutrophil accumulation in the gut during Salmonella infection and in the lung during Acinetobacter infection. Neutrophils isolated from the infected mucosa express CCL28 receptors on their surface, and CCL28 stimulation enhances neutrophil antimicrobial activity. The absence of CCL28 in mice confers protection against Acinetobacter infection but makes them susceptible to Salmonella infection. These findings highlight the importance of CCL28 in the immune response to bacterial infections. The document also provides information on the materials and methods used in the study, as well as references to related scientific articles. [Extracted from the article]

The stem cell niche in the bone marrow is a hypoxic environment, where the low oxygen tension preserves the pluripotency of stem cells. We have identified mesangiogenic progenitor cells (MPC) exhibiting angiogenic and mesenchymal differentiation capabilities in vitro. The effect of hypoxia on MPC has not been previously explored. In this study, MPCs were isolated from volunteers' bone marrow and cultured under both normoxic and hypoxic conditions (3% O2). MPCs maintained their characteristic morphology and surface marker expression (CD18 + CD31 + CD90-CD73-) under hypoxia. However, hypoxic conditions led to reduced MPC proliferation in primary cultures and hindered their differentiation into mesenchymal stem cells (MSCs) upon exposure to differentiative medium. First passage MSCs derived from MPC appeared unaffected by hypoxia, exhibiting no discernible differences in proliferative potential or cell cycle. However, hypoxia impeded the subsequent osteogenic differentiation of MSCs, as evidenced by decreased hydroxyapatite deposition. Conversely, hypoxia did not impact the angiogenic differentiation potential of MPCs, as demonstrated by spheroid-based assays revealing comparable angiogenic sprouting and tube-like formation capabilities under both hypoxic and normoxic conditions. These findings indicate that hypoxia preserves the stemness phenotype of MPCs, inhibits their differentiation into MSCs, and hampers their osteogenic maturation while leaving their angiogenic potential unaffected. Our study sheds light on the intricate effects of hypoxia on bone marrow-derived MPCs and their differentiation pathways. [ABSTRACT FROM AUTHOR]

This letter to the editor discusses the successful treatment of a heavily pretreated patient with multiple myeloma and liver extramedullary disease using belantamab mafodotin (Belamaf). Extramedullary disease is a rare and aggressive form of multiple myeloma characterized by the presence of soft-tissue plasmacytomas. Belamaf is a first-in-class drug that targets B-cell maturation antigen (BCMA) and has shown promising results in clinical trials. The patient in this case study experienced complete resolution of liver lesions after treatment with Belamaf, although the drug has since been withdrawn from the market due to the results of a clinical trial. Ongoing clinical trials are investigating the use of Belamaf in combination with other drugs. [Extracted from the article]

Background: The field of immunology has undoubtedly benefited from the in vitro use of cell lines for immunological studies; however, due to the "immortal" nature of many cell lines, they are not always the best model. Thus, direct collection and culture of primary cells from model organisms is a solution that many researchers utilize. To the best of our knowledge, there is not a singular protocol which encompasses the entire process of bone marrow cell collection through cryopreservation and resuscitation of cells from a murine model. Methods: Bone marrow cells were collected from mice with a C57BL6 genetic background. Cells were differentiated using L929 conditioned media. Cells were assessed using a combination of microscopy, differential staining, immunocytochemistry, and trypan blue. Results: Primary murine BMDMs that underwent cryopreservation followed by resuscitation retained a high degree of viability. Furthermore, these BMDMs retained on overall ability to clear S. aureus. Results: Primary murine BMDMs that underwent cryopreservation followed by resuscitation retained a high degree of viability. Furthermore, these BMDMs retained on overall ability to clear S. aureus. Conclusion: Crypopreserved and resuscitated primary murine BMDMs were viable and retained their pverall S. aureus clearance ability. [ABSTRACT FROM AUTHOR]

This article discusses the use of allogenic haematopoietic stem cell transplantation (HSCT) as a potential treatment for subcutaneous panniculitis-like T-cell lymphoma (SPTCL) with a specific genetic mutation. SPTCL is a rare disease with no agreed-upon treatment. The study focuses on one patient who did not respond to other treatments and received HSCT from a sibling donor. The patient achieved complete remission, suggesting that HSCT could be an effective therapy for SPTCL patients with this genetic mutation. The article also includes a table summarizing the characteristics and treatment outcomes of 13 SPTCL patients from diverse ethnic backgrounds. The study was funded by the Japan Society for the Promotion of Science and declares no conflicts of interest. [Extracted from the article]

According to the International Agency for Research on Cancer, leukemia ranks 14th in incidence and 11th in mortality and has a 5-year prevalence of approximately 1300,000 cases. Acute lymphoblastic leukemia is the most common hematopoietic syndrome in children during the first 5 years of life and represents approximately 75 % of all neoplasms among the pediatric population. The development of leukemia is strongly governed by DNA alterations that accelerate the growth of bone marrow cells. Currently, the most examined factor in pediatric leukemia is exposure to multiple compounds, such as hydrocarbons. Benzene, an aromatic hydrocarbon, can cause health challenges and is categorized as a carcinogen. Benzene toxicity has been widely associated with occupational exposure. Importantly, studies are underway to generate evidence that can provide clues regarding the risk of environmental benzene exposure and hematological problems in children. In this review, we summarize the existing evidence regarding the effects of benzene on pediatric leukemia, the associations between the effect of benzene on carcinogenesis, and the presence of certain molecular signatures in benzene-associated pediatric leukemia. Although there is sufficient evidence regarding the effects of benzene on carcinogenesis and leukemia, epidemiological research has primarily focused on occupational risk. Moreover, most benzene-induced molecular and cytogenetic alterations have been widely described in adults but not in the pediatric population. Thus, epidemiological efforts are crucial in the pediatric population in terms of epidemiological, clinical, and biomedical research. [Display omitted] • Pediatric leukemia incidence, mortality, and long-term prevalence represents a global health concern. • Acute lymphoblastic leukemia is the most frequent hematopoietic neoplasia in children. • Benzene, a carcinogenic aromatic hydrocarbon, represents a risk factor in hematopoietic tumors. • Evidence regarding the effects of benzene on pediatric leukemia is increasing, but still limited. • Future epidemiological efforts may provide insight into the mechanisms of benzene on pediatric leukemia. [ABSTRACT FROM AUTHOR]

Background: The effect of the expression of the newly identified immune checkpoint, T cell immunoglobulin and immunoreceptor tyrosine-based inhibition motif domain (TIGIT) on NK cells in core binding factor-acute myeloid leukemia (CBF-AML) remains to be investigated. Methods: Fresh bone marrow samples from a total of 39 newly diagnosed CBF-AML patients and 25 healthy donors (HDs) were collected for testing the phenotype and function state of total NK, CD56bright, and CD56dim NK cell subsets after in vitro stimulation. Results: The frequencies of TIGIT+ cells in total NK, CD56bright, and CD56dim NK cell subsets had no significant difference between patients and HDs. TNF-α and INF-γ levels were uniformly lower in TIGIT+ cells than the corresponding TIGIT− cells in all HDs, whereas those for TIGIT+ to TIGIT− cells in patients were highly heterogenous; TIGIT expression was not related to PFP and GZMB expression in HDs, whereas it was related to higher intracellular PFP and GZMB levels in patients. Patients' TIGIT+ NK cells displayed lower K562 cell-killing activity than their TIGIT− NK cells. In addition, high frequencies of TIGIT+ cells in total NK and CD56dim NK cells were associated with poor RFS. Conclusions: TIGIT expression affected the diagnostic bone marrow-sited NK cell function and had prognostic significance in CBF-AML patients. [ABSTRACT FROM AUTHOR]

Macrophage and osteoclast proliferation, differentiation and survival are regulated by colony-stimulating factor 1 receptor (CSF1R) signaling. Osteopetrosis associated with Csf1 and Csf1r mutations has been attributed to the loss of osteoclasts and deficiency in bone resorption. Here, we demonstrate that homozygous Csf1r mutation in rat leads to delayed postnatal skeletal ossification associated with substantial loss of osteal macrophages in addition to osteoclasts. Osteosclerosis and site-specific skeletal abnormalities were reversed by intraperitoneal transfer of wild-type bone marrow cells (bone marrow cell transfer, BMT) at weaning. Following BMT, IBA1+ macrophages were detected before TRAP+ osteoclasts at sites of ossification restoration. These observations extend evidence that osteal macrophages independently contribute to bone anabolism and are required for normal postnatal bone growth and morphogenesis. [ABSTRACT FROM AUTHOR]

Background: The aim of the study was to improve the clinical cognition of nonaccelerating myelodysplastic/myeloproliferative neoplasms-unclassifiable (MDS/MPN-U) with 5q- karyotype and to avoid misdiagnosis or delayed diagnosis. Methods: The clinical manifestations and laboratory results of a patient with nonaccelerating MDS/MPN-U with 5q- karyotype were analyzed, and related literature was reviewed. Results: The patient was admitted to hospital mainly due to chest tightness and shortness of breath, aggravated for 4 days. After admission, combined with clinical manifestations, bone marrow cell morphology, immunology, multiparameter flow cytometry, cytogenetics and molecular biology, etc., the final diagnosis was MDS-MPN-U. Conclusions: Research on the correlation between MPN-U and MDS with 5q deletion is still needed. Clinically, MPN-U combined with MDS is prone to misdiagnosis. In diagnosing MPN-U patients, it is essential to not only complete routine and immunological tests but also consider clinical manifestations and laboratory results. It is crucial to be vigilant about the possibility of concurrent diseases, especially cancer, and to choose targeted examinations in a timely manner to avoid missed or incorrect diagnoses. [ABSTRACT FROM AUTHOR]

Background: This study aimed to explore the clinical significance of ruxolitinib and its effects on the proliferation and apoptosis of human erythroleukemia (HEL) cells and the expression of immune checkpoint molecules programmed death-1 (PD-1), programmed death-ligand 1 (PD-L1), and regulatory T cells (Tregs) in HEL cells and JAK2 V617F-positive patients with myeloproliferative neoplasms (MPNs). Methods: JAK2 V617F-positive patients with MPNs admitted to the Baoding No. 1 Hospital from January 2016 to September 2023 were recruited, including 30 patients for the newly diagnosed group and 10 for the treatment group. Additionally, 15 healthy volunteers were selected as the control group. JAK2 V617F mutation was detected by using fluorescence quantitative PCR, and the expression levels of phosphorylated JAK2 (p-JAK2), PD-1, and PD-L1 in fresh bone marrow were examined by immunohistochemistry. HEL cells were treated with ruxolitinib at different concentrations (0, 50, 100, 250, 500, and 1,000 nmol/L). Cell viability was detected by CCK-8 assay. The mRNA expression levels of JAK2, PD-1, and PD-L1 were determined by using fluorescence quantitative PCR. The protein expression of p-JAK2 was detected by Western blot and those of PD-1 and PD-L1 were evaluated by flow cytometry. The expression of PD-1, PD-L1, and Tregs after the 48-hour co-culture of primary bone marrow cells and HEL cells were also analyzed by flow cytometry. Results: In the newly diagnosed group, the bone marrow myeloid cells highly expressed p-JAK2, PD-1, and PDL1. The Tregs expression in their peripheral blood increased and was significantly higher than those in the treatment and control groups (all p < 0.05). Ruxolitinib at different concentrations could inhibit the proliferation of HEL cells and was positively correlated with treatment time and dose. Additionally, ruxolitinib could reduce p- JAK2, PD-1, and PD-L1 expression in HEL cells and Tregs expression. Conclusions: Ruxolitinib reduces the expression of p-JAK2, PD-1, and PD-L1 in JAK2 V617F-positive cells by specifically inhibiting the JAK2 signaling pathway, thereby suppressing the progression of MPNs. [ABSTRACT FROM AUTHOR]

After primary infection, human cytomegalovirus (HCMV) establishes lifelong persistence, underpinned by latent carriage of the virus with spontaneous reactivation events. In the immune-competent, primary infection or reactivation from latency rarely causes disease. However, HCMV can cause significant disease in immune-compromised individuals such as immune-suppressed transplant patients. Latency, where the viral genome is carried in the absence of the production of infectious virions, can be established in undifferentiated cells of the myeloid lineage. A number of stimuli can cause virus reactivation from latency to occur, beginning with the induction of viral immediate-early (IE) lytic gene expression. The suppression of viral IE gene expression to establish and maintain latent infection is known to result from a balance of viral and cellular factors. One key viral factor involved in this is the G protein-coupled receptor US28. Recently, we have shown that US28 is targeted for degradation by a modified nanobody (PCTD-Vun100bv) based on the novel PACTAC (PCSK9-antibody clearance-targeting chimeras) approach for targeted protein degradation. Furthermore, we have shown that this PCTD-Vun100bv-induced degradation of US28 results in IE gene expression in experimentally latently infected CD14+ monocytes. However, HCMV also establishes latency in CD34+ bone marrow cells, the progenitors of CD14+ cells. Here, we show that PCTD-Vun100bv also causes US28 degradation in these CD34+ primary cells, again resulting in the induction of viral IE gene expression. Additionally, we show that PCTD-Vun100bv can target US28 in naturally latently infected CD14+ monocytes from an HCMV-seropositive donor, allowing these latently infected cells to be killed by HCMV-specific cytotoxic T cells from that same donor. These observations support the view that targeting US28 for degradation during natural latency could be a tractable 'shock-and-kill' strategy to target the latent HCMV reservoir in myeloid cells. [ABSTRACT FROM AUTHOR]