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Chimeric antigen receptor (CAR)-engineered T cell therapy holds promise for treating myeloid malignancies, but challenges remain in bone marrow (BM) infiltration and targeting BM-resident malignant cells. Current autologous CAR-T therapies also face manufacturing and patient selection issues, underscoring the need for off-the-shelf products. In this study, we characterize primary patient samples and identify a unique therapeutic opportunity for CAR-engineered invariant natural killer T (CAR-NKT) cells. Using stem cell gene engineering and a clinically guided culture method, we generate allogeneic CD33-directed CAR-NKT cells with high yield, purity, and robustness. In preclinical mouse models, CAR-NKT cells exhibit strong BM homing and effectively target BM-resident malignant blast cells, including CD33-low/negative leukemia stem and progenitor cells. Furthermore, CAR-NKT cells synergize with hypomethylating agents, enhancing tumor-killing efficacy. These cells also show minimal off-tumor toxicity, reduced graft-versus-host disease and cytokine release syndrome risks, and resistance to allorejection, highlighting their substantial therapeutic potential for treating myeloid malignancies.

Fixation and demineralization protocols for bone marrow (BM) across diagnostic laboratories are not standardized. How different protocols affect histomorphology and DNA amplification is incompletely understood. In this study, 2 fixatives and 3 demineralization methods were tested on canine BM samples. Twenty replicate sternal samples obtained within 24 hours of death were fixed overnight in either acetic acid-zinc-formalin (AZF) or 10% neutral-buffered formalin (NBF) and demineralized with formic acid for 12 hours. Another 53 samples were fixed in AZF and demineralized with hydrochloric acid for 1-hour, formic acid for 12 hours, or ethylenediamine tetraacetic acid (EDTA) for 24 hours. Histologic sections were scored by 4 raters as of insufficient, marginal, good, or excellent quality. In addition, DNA samples extracted from sections treated with the different fixation and demineralization methods were amplified with 3 sets of primers to conserved regions of T cell receptor gamma and immunoglobulin heavy chain genes. Amplification efficiency was graded based on review of capillary electrophoretograms. There was no significant difference in the histomorphology scores of sections fixed in AZF or NBF. However, EDTA-based demineralization yielded higher histomorphology scores than demineralization with hydrochloric or formic acid, whereas formic acid resulted in higher scores than hydrochloric acid. Demineralization with EDTA yielded DNA amplification in 29 of 36 (81%) samples, whereas demineralization with either acid yielded amplification in only 2 of 72 (3%) samples. Although slightly more time-consuming and labor-intensive, tissue demineralization with EDTA results in superior morphology and is critical for polymerase chain reaction (PCR) amplification with the DNA extraction method described in this article.

Despite the various treatments proposed with barrier membranes, one of the main challenges for guided bone regeneration (GBR) is maintaining space for large defects and ensuring an adequate blood supply. The presented feasibility case series aims to introduce an original titanium frame (TF) design, customized for each defect, as a modification of well-known principles and materials for GBR to achieve an enhanced and more predictable horizontal and vertical bone augmentation. Three patients with significant horizontal defects were treated with pre-trimmed TFs to create needed space, and then a 50/50 mixture of autograft and bovine xenograft was placed and covered with a collagen membrane. After 8 months of healing, the sites were reopened, and the titanium screws were removed with the frame. An average of 8.0 ± 1.0 mm of horizontal and 3.0 ± 0.0 mm of vertical bone gain were achieved at the time of reentry and implant placement surgery. Bone core biopsy sample was obtained during the implant placement. Histomorphometric analysis revealed that 42.8% of the sample was new vital bone, 18.8% was residual bone graft particles, and 38.4% was bone marrow-like structures. After 3 to 4 months from implant placement, the implants were restored with provisional crowns and then finalized with zirconia screw-retained crowns. This case series suggests that GBR utilizing TFs with or without collagen membranes can be considered a suitable approach for horizontal and vertical bone augmentation. However, based on only three reported cases, the results should be carefully interpreted. [ABSTRACT FROM AUTHOR]

BACKGROUND: Cistanoside A has the effects of anti-inflammation, antioxidation, antioxidation, reducing renal damage and anti-osteoporosis, but its effect on osteoclast differentiation, function and its underlying molecular mechanisms remain unclear. OBJECTIVE: To investigate the effect of Cistanoside A on osteoclast differentiation and bone resorption induced by receptor activator of nuclear factor kappa-B ligand (RANKL) in vitro and its mechanism. METHODS: Bone marrow macrophages were obtained from the femur and tibia of 4-6-week-old C57BL/6 mice. The cytotoxic effect of Cistanoside A (5, 10, 20, 40, 80, and 160 μmol/L) on bone marrow macrophage viability was examined using the cell counting kit-8 assay kit. Tartrate-resistant acid phosphatase staining was performed to observe the effect of different concentrations of Cistanoside A on osteoblast differentiation and its effective intervention concentration was determined. There was positive control group, Cistanoside A low, medium, and high dose groups (40, 80, and 160 μmol/L). After cell attachment, 50 ng/mL RANKL was added to induce osteoblast differentiation, and the corresponding dose of Cistanoside A was added to the Cistanoside A low, medium, and high dose groups, respectively. F-actin ring and 2-(4-Amidinophenyl)-6-indolecarbamidine dihydrochloride staining were performed to detect the effects of Cistanoside A on the formation of osteoclasts. Toluidine blue staining of bone abrasion slices was used to observe the effects of Cistanoside A on bone resorption function of osteoclasts. The expression of upstream and downstream proteins of the JNK/MAPK pathway was detected by Western blot. The expression of genes related to osteoclast differentiation and bone resorption function such as tartrate-resistant acid phosphatase, DC-STAMP, Nfatc-1, Ctsk and c-Fos was detected by RTqPCR. RESULTS AND CONCLUSION: Tartrate-resistant acid phosphatase staining, F-actin ring staining and resorption pit assay showed that Cistanoside A significantly inhibited RANKL-induced osteoclast differentiation and bone resorption in a dose-dependent manner compared with the positive control group. The results of RT-qPCR showed that compared with the positive control group, both high and low dose groups of Cistanoside A could significantly downregulate the mRNA expression of tartrate-resistant acid phosphatase, DC-STAMP, Nfatc-1, Ctsk and c-Fos in a dosedependent manner. The results of western blot assay showed that the high dose group of Cistanoside A significantly inhibited the expression of p-JNK protein at 10, 20, 30 and 60 minutes of intervention; compared with the positive control group, Cistanoside A significantly inhibited the expression of Nfatc1 and c-Fos proteins in a dose-dependent manner. To conclude, Cistanoside A could inhibit the formation and bone resorption of osteoclasts by reducing the level of p-JNK protein, inhibiting the activation of MAPK pathway and the expression of key genes in osteoclasts. [ABSTRACT FROM AUTHOR]

Background: Neutrophil granulocytes are important parts of the defence against bacterial infections. Their action is a two-edged sword, the mediators killing the intruding bacteria are at the same time causing tissue damage. Neutrophil activation is part of the dysregulated immune response to infection defining sepsis and neutrophil elastase is one of the powerful proteases causing both effects and damage. Inhibition of neutrophil elastase has been tried in sepsis and ARDS, so far with inconclusive results. Methods: We used positron emission tomography (PET) combined with computed tomography (CT) and the selective and specific neutrophil elastase inhibitor PET-tracer [11C]GW457427 ([11C]NES), in an intensive care unit porcine Escherichia coli sepsis model with the primary aim to visualise the biodistribution of neutrophil elastase in the initial acute phase of the septic reaction. Repeated PET–CT investigations were performed before and after induction of sepsis. Results: At baseline [11C]NES uptake was found in the bone marrow, spleen and liver. The uptake in the bone marrow was markedly increased two hours into the sepsis, whereas in spleen and liver the uptake was not as markedly changed compared to baseline. At 4 h after the sepsis induction [11C]NES in the bone marrow decreased while the uptake increased in the spleen, liver and lungs. Conclusion: The neutrophil elastase PET-tracer [11C]NES is a novel and unique instrument to study the acute innate neutrophil immune response in sepsis and associated vital organ failure. We here present images and quantitative data of the neutrophil elastase distribution the first hours of acute experimental sepsis. Surprisingly, a pronounced increase of neutrophil elastase was found in the bone marrow 2 h into the sepsis reaction followed at 4 h by increase in the liver, spleen and lungs and a concomitant reduction of the tracer uptake in bone marrow. [ABSTRACT FROM AUTHOR]

Polymorphonuclear neutrophils (PMNs), the most abundant leukocytes circulating in human blood, are pivotal players in the innate immune system. In recent years, PMNs have gained increasing recognition for their significant involvement in the pathogenesis of a wide array of human diseases, including sepsis, pulmonary conditions, autoimmune disorders, and various cancers. Due to their terminally differentiated state, PMNs possess a short lifespan and exhibit limited proliferative potential, which makes continuous replenishment from the bone marrow essential for maintaining immune homeostasis. This demand underscores the need for efficient, reliable, and robust methods of PMN production. In this study, we evaluated three forward programming protocols and one directed differentiation protocol aimed at generating PMNs from human pluripotent stem cells (hPSCs). We analyzed not only their differentiation efficiency but also the transcriptomic profiles and functional capabilities of the resulting PMNs. Our findings revealed that both the forward programming method and the directed differentiation approach can successfully generate functional PMNs. Furthermore, by fine-tuning the culture media at various stages during forward programming, we identified an optimal protocol that significantly enhances hematopoietic differentiation potential and promotes the functional maturity of the neutrophils. [ABSTRACT FROM AUTHOR]

Neutrophils are rapidly recruited to sites of infection, injury, or to immune complexes. Upon arrival, they initiate degranulation, release reactive oxygen species (ROS), and/or nuclear extracellular traps (NETs) to eliminate invading microorganisms, clear debris, or remove abnormal immunoglobulins. While these processes ideally trigger healing and a return to balance, overshooting neutrophil function can lead to life-threatening infections such as sepsis or persistent inflammation observed in various autoimmune diseases. However, recent evidence highlights a phenotypic and functional heterogeneity of neutrophils that extends well beyond their traditional - potentially harmful- role as first responders. For example, neutrophils regulate ongoing inflammation by modulating macrophage function through efferocytosis, T cell responses by antigen presentation and the release of cytokines. The factors that induce neutrophil differentiation into activating or regulatory phenotypes remain poorly defined. Here, we hypothesize that intracellular components that have been released into the extracellular space could contribute to the phenotypic heterogeneity of neutrophils. To find out, we used nanoparticles composed of intracellular proteins (cell-derived nanoparticles, CDNPs) and analyzed their effects on cultured murine bone marrow neutrophils (BMN). We observed that CDNPs activate BMN transiently with an increase in the expression of CD11b without triggering classical effector functions. Additionally, CDNPs induce the secretion of IL-10, shift PMA-induced cell death toward apoptosis, and increase the expression of CD80. Mechanistically, our findings indicate that 26% of BMNs ingest CDNPs. These BMNs preferentially express CD54+, fail to migrate toward CXCL12, exhibit diminished responses to LPS, and undergo apoptosis. These data identify CDNPs as biomaterials that modulate neutrophil behavior by fine-tuning the expression of CD11b and CD80. [ABSTRACT FROM AUTHOR]

Men develop larger infarct sizes than women after a myocardial infarction (MI), but the mechanism underlying this sex difference is unknown. Here, we demonstrated that blood neutrophil counts post-MI were higher in male than female mice. Castration-induced testosterone deficiency reduced blood neutrophil counts to the level in females and increased survival post-MI. These effects were mimicked by Osterix-directed ablation of the androgen receptor in bone marrow (BM). Mechanistically, androgens downregulated the leukocyte retention factor CXCL12 in BM stromal cells. Post-hoc analysis of clinical trial data showed that neutrophilia was greater in men than women after reperfusion of first-time ST-elevation MI, and tocilizumab, an interleukin-6 receptor inhibitor, reduced blood neutrophil counts and infarct size to a greater extent in men than women. Our work reveals a previously unknown mechanism connecting testosterone with neutrophilia and MI injury via BM and identifies the importance of considering sex when developing anti-inflammatory strategies to treat MI. Men develop larger myocardial infarction (MI) sizes than women. Here, the authors show that male sex and testosterone, via bone marrow stroma, exacerbates MI-induced neutrophilia and cardiac injury and that response to anti-inflammatory treatment in MI is greater in men than women [ABSTRACT FROM AUTHOR]

Background: Natural killer cells, an important component of the innate immune system, can directly recognize and lyse virally infected or transformed cells. However, NK cells fail to restrain the growth of malignancies, such as B-cell acute lymphoblastic leukemia (B-ALL). The molecular genetics of NK cells in the B-ALL bone marrow microenvironment and the mechanisms underlying the inhibited function of NK cells at the single-cell level remain largely elusive. Methods: In this study, we studied the frequency and absolute number of NK cells in peripheral blood samples collected from 43 healthy volunteers and 104 pediatric B-ALL patients diagnosed at Hunan Children's Hospital. We also analyzed published single-cell RNA sequencing (scRNAseq) data from B-ALL and normal bone marrow samples using unsupervised clustering. Our findings were further validated using bulk transcriptomic data and clinical data from a cohort of 139 B-ALL bone marrow samples. Results: We found that the frequency and number of NK cells were significantly decreased in the bone marrow and peripheral blood of B-ALL patients. In-depth analysis of scRNAseq data identified 12 NK cell clusters. Among them, the C2 cluster, which is present in healthy bone marrow but reduced in B-ALL bone marrow, displays overexpression of a transcription factor KLF2 and a significant downregulation of the "leukocyte proliferation" pathway. Furthermore, we found that the expression of KLF2 in B-ALL at diagnosis was positively correlated with the percentage of leukemia cells and the positive rate of minimal residual disease (MRD), indicating that KLF2 is a marker of poor prognosis. Conclusion: There are dramatic differences at the single-cell level in the transcriptomics of NK cells between healthy donors and B-ALL patients. A transcription factor, KLF2, which is enriched in the C2 cluster of NK cells, has been suggested to regulate the proliferation of NK cells and is associated with poor prognosis of pediatric B-ALL. [ABSTRACT FROM AUTHOR]

Murine double minute 2 (MDM2) inhibitors have shown promising activity in TP53-wild type tumors and are under active investigation across a spectrum of malignancies. Herein, we report a 51-year-old female with MDM2-amplified, TP53-wild type adenoid cystic carcinoma who was treated with a MDM2 inhibitor and developed persistent pancytopenia despite drug discontinuation. Her pancytopenia was associated with 20 distinct pathogenic TP53 mutations in peripheral blood and bone marrow not present in drug-resistant tumor tissue. Plasma TP53 mutations were similarly detected among 4 other patients treated at our institution, with the number of mutations correlating strongly with duration of treatment. This case suggests that MDM2 inhibitors are associated with TP53 clonal hematopoiesis, which may confer a risk of subsequent myeloid malignancy. As multiple MDM2 inhibitor trials are ongoing, our findings underscore the need for further investigation into the potential long-term deleterious effects of these inhibitors in the hematopoietic stem and progenitor compartment. [ABSTRACT FROM AUTHOR]

Sarcoid-like reaction (SLR) has been reported in patients with solid tumor malignancies, lymphomas, and patients receiving immunotherapy. SLR is often incidentally found during positron emission tomography/computed tomography scans as hilar and/or mediastinal lymphadenopathy. SLR has also been found in the lung, spleen, bone marrow, and skin. Biopsy of these lesions shows noncaseating granulomas. When systemic criteria are not met for sarcoidosis, these noncaseating granulomas are termed SLR. We present the first case in the literature of a case of orbital SLR in a patient with concomitant diffuse large B-cell lymphoma and inverted papilloma of the maxillary sinus. This case highlights the importance of including malignancy in the differential for the presence of a noncaseating granuloma in the orbit. [ABSTRACT FROM AUTHOR]

Acute manifestations of sickle cell disease (SCD) are numerous and multisystemic. Cerebral fat embolism (CFE) is a rare but serious complication of SCD caused by bone marrow necrosis (BMN) during vaso-occlusive crises (VOC). We present the case of a 41-year-old man with SCD who developed severe VOC and multi-organ dysfunction. He subsequently experienced neurological deterioration with decreased consciousness and diffuse encephalopathy on serial electroencephalograms. Bone marrow aspiration confirmed BMN. Brain MRI revealed extensive diffuse leukoencephalopathy, vasogenic and cytotoxic edema in the white matter, patchy edema in the cranial vault bone marrow on fat-suppressed FLAIR sequence (a finding consistent with the confirmed BMN), and multiple cerebral microbleeds on susceptibility-weighted imaging consistent with CFE. The management of acute neurological complications of SCD varies depending on the specific complication. Brain MRI plays a crucial role in the accurate diagnosis of these complications to guide appropriate treatment. [ABSTRACT FROM AUTHOR]

Introduction: The influence of patient age on the clinical outcome of surgically treated osteochondral lesions of the talus (OCT) is controversial. Aim of this study was to evaluate the 24 months follow-up data of the German Cartilage Registry (KnorpelRegister DGOU, GCR) regarding the influence of patient age on clinical outcomes after surgical OCT treatment. Materials and methods: 303 patients met the inclusion criteria and were divided into patients < 40 years (27.1 ± 5.8 years, n = 177) and patients ≥ 40 years (50.8 ± 7.4 years, n = 126). Pre- and postoperative FAOS total scores, subscores and ΔFAOS for most frequent surgical techniques (bone marrow stimulation, matrix-augmented bone marrow stimulation, matrix-augmented bone marrow stimulation with additional bone grafting) and lesion size characteristics were evaluated for both groups. ANOVA analysis with post hoc Duncan test was applied for statistical analysis. Results: Both patients < 40 years and patients ≥ 40 years benefit from surgical treatment of OCT showing significant changes from pre- to postoperative FAOS total score (63.8 ± 20.3 to 81.5 ± 17.8 in patients < 40 years, p < 0.001; 57.3 ± 20.1 to 74.9 ± 21.6 in patients ≥ 40 years, p < 0.001) and subscores. Younger patient group tended to higher pre- and postoperative scores. ΔFAOS was not different between both groups. Older patient group had significantly higher lesion size area and volume; proportion of additional bone grafting was increased. Conclusion: Results of surgical therapy of OCTs are independent from patient age. There is no superiority of a specific surgical technique depending on patient age. [ABSTRACT FROM AUTHOR]

The hematopoietic system is the primary target of benzene exposure. Whether peripheral blood miRNA can serve as sensitive biomarkers for benzene-induced hematopoietic damage has attracted considerable attention. This study focuses on exploring the role of miR-451a and miR-486-5p in benzene-induced erythroid damage and assessing their potential as biomarkers of benzene-induced hematotoxicity. Animal experiments and human studies were conducted to reveal expression patterns of miR-451a and miR-486-5p in bone marrow and peripheral blood after benzene exposure, along with their correlations with erythrocyte indices. In C57BL/6J mice exposed to benzene, the expression levels of miR-451a and miR-486-5p in bone marrow decreased, which also positively correlated with red blood cell count (RBC), hemoglobin (Hb), and hematocrit (HCT). Conversely, in peripheral blood of C57BL/6J mice, the expression levels of the two miRNAs increased and showed a negative correlation with the three erythroid indices. Subsequent validation in bone marrow samples of chronic benzene poisoning patients and peripheral blood of workers from petrochemical plant confirmed significant correlations between miR-451a and miR-486-5p expression levels and red blood cell parameters. Furthermore, receiver operator characteristic (ROC) curve analyses revealed that miR-451a emerged as a potential biomarker for benzene-induced hematotoxicity, exhibiting superior discriminatory power compared to miR-486-5p and conventional erythroid indices. Additionally, in vitro experiments using K562 cells revealed differential regulatory effects of benzene metabolite hydroquinone (HQ) on miR-451a expression based on erythroid differentiation status. These findings emphasized the important role of miR-451a and miR-486-5p in benzene-induced erythrogenesis disruption, offering valuable insights for biomarker development and therapeutic interventions. [ABSTRACT FROM AUTHOR]

The increasing use of SARS-CoV-2 mRNA vaccines has raised concerns about their potential toxicological effects, necessitating further investigation to ensure their safety. To address this issue, we aimed to evaluate the toxicological effects of SARS-CoV-2 mRNA vaccine candidates formulated with four different types of lipid nanoparticles in ICR mice, focusing on repeated doses and administration routes. We conducted an extensive analysis in which mice received the mRNA vaccine candidates intramuscularly (50 μg/head) twice at 2-week intervals, followed by necropsy at 2 and 14 dpsi (days post-secondary injection). In addition, we performed a repeated dose toxicity test involving three, four, or five doses and compared the toxicological outcomes between intravenous and intramuscular routes. Our findings revealed that all vaccine candidates significantly induced SARS-CoV-2 spike protein-specific IgG and T cell responses. However, at 2 dpsi, there was a notable temporary decrease in lymphocyte and reticulocyte counts, anemia-related parameters, and significant increases in cardiac damage markers, troponin-I and NT-proBNP. Histopathological analysis revealed severe inflammation and necrosis at the injection site, decreased erythroid cells in bone marrow, cortical atrophy of the thymus, and increased spleen cellularity. While most toxicological changes observed at 2 dpsi had resolved by 14 dpsi, spleen enlargement and injection site damage persisted. Furthermore, repeated doses led to the accumulation of toxicity, and different administration routes resulted in distinct toxicological phenotypes. These findings highlight the potential toxicological risks associated with mRNA vaccines, emphasizing the necessity to carefully consider administration routes and dosage regimens in vaccine safety evaluations, particularly given the presence of bone marrow and immune organ toxicity, which, though eventually reversible, remains a serious concern. [ABSTRACT FROM AUTHOR]

Objective: Sepsis is a syndrome of the systemic inflammatory response caused by infection that can endanger a patient's life. The aim of this study was to explore the molecular mechanism by which bone marrow mesenchymal stem cells-derived exosomes (BMSCs-exo) carrying miR-20a-5p regulate the progression of sepsis. Methods: Clinical samples from sepsis patients were collected. Mouse and cell models of sepsis were induced by lipopolysaccharide (LPS). The levels of related genes and proteins were determined by RT‒qPCR, Western blotting and ELISA. CCK-8 and flow cytometry assays were used to assess cell viability, apoptosis, and markers of macrophage polarization. Results: In septic patients, miR-20a-5p levels were significantly lower and CXCL12 expression was significantly increased. After LPS induction, M2 polarization of macrophages was significantly reduced, the level of inflammatory factors was increased, and apoptosis was increased. The addition of BMSCs-exo increased the miR-20a-5p level and decreased the expression of CXCL12 in macrophages, thereby promoting macrophage M2 polarization and reducing the levels of inflammatory factors. Conclusion: This study demonstrated for the first time that BMSCs-exo promoted the polarization of M2 macrophages through the miR-20a-5p/CXCL12 axis, thus alleviating the development of sepsis. These findings provide a new theoretical basis for the targeted treatment of sepsis with exosomes or miR-20a-5p. [ABSTRACT FROM AUTHOR]

MiRNAs have been identified as participants in leukemogenesis by controlling several cellular functions, such as differentiation, proliferation, and apoptosis. Their role in myelodysplastic neoplasms (MDS) pathogenesis is researched due to implementations in early identification, classification, and therapeutical options. IPSS-R, being the most widely used MDS classification, underestimates early biological events that can alter the disease's prognosis. The purpose of this study is to determine whether miRNA levels are aligned to MDS risk stratification groups and can therefore be used as diagnostic biomarkers. To evaluate miRNAs as possible biomarkers, we measured the levels of miR-181a-2-3p, miR-124-3p, miR-550a-3p, miR-155-5p, miR-151a-3p, and miR-125b-5p by a quantitative real-time PCR in bone marrow samples of 41 MDS patients. In conclusion, in myeloid malignancies, genomic characteristics may provide a wider apprehension of its clinical course and prognosis. MiRNAs constitute a possible diagnostic biomarker and therapeutic target, allowing intermediate-risk patients that express high levels of specific miRNAs to be re-classified and receive more advanced therapeutic agents. In our study, an association between high levels of miRNAs and worsening outcomes is established, supporting the need for further incorporation of molecular data into currently used classification systems. [ABSTRACT FROM AUTHOR]

Objective: To examine the association between medial meniscal extrusion and structural progression in adults with symptomatic knee osteoarthritis (OA). Methods: This prospective cohort study examined 176 participants with symptomatic knee OA recruited into a randomised controlled trial. The participants underwent magnetic resonance imaging (MRI) of the study knee at baseline and approximately 2 years later. Meniscal extrusion, tibial cartilage volume, and tibiofemoral bone marrow lesions (BMLs) were measured from MRI using validated methods. Results: Participants with medial meniscal extrusion ≥ 3 mm had a higher prevalence of lateral tibiofemoral BMLs at baseline (OR = 2.21, 95% CI 1.06–4.61, p = 0.035), and those with medial meniscal extrusion 2–3 mm had a higher likelihood of lateral BML worsening over 2 years (OR = 3.76, 95% CI 1.35–10.52, p = 0.011), compared with those with medial meniscal extrusion < 2 mm. Participants with stable medial meniscal extrusion had a lower likelihood of lateral BML worsening compared with those with regression of medial meniscal extrusion over 2 years (OR = 0.20, 95% CI 0.07–0.56, p = 0.002). There were no associations between medial meniscal extrusion and tibial cartilage volume or medial tibiofemoral BMLs. Conclusions: Our study showed associations between medial meniscal extrusion and baseline prevalence and worsening over 2 years of lateral tibiofemoral BMLs in people with symptomatic knee OA. Although the reasons for the lack of associations in the medial compartment are not clear, our results suggest a role of medial meniscal extrusion in predicting structural progression in lateral knee OA and that meniscal extrusion might be a potential target in the management of knee OA. [ABSTRACT FROM AUTHOR]

Osteoarthritis (OA) is a leading cause of pain, functional impairment, and disability in older adults. However, there are no effective treatments to delay and reverse OA. Magnetic resonance imaging (MRI) can assess structural abnormalities of OA by directly visualizing damage and inflammatory reactions within the tissues and detecting abnormal signals in the subchondral bone marrow region. While some studies have shown that bone marrow lesions (BMLs) are one of the early signs of the development of OA and predict structural and symptomatic progression of OA, others claimed that BMLs are prevalent in the general population and have no role in the progression of OA. In this narrative review, we screened and summarized studies with different designs that evaluated the association of BMLs with joint symptoms and structural abnormalities of OA. We also discussed whether BMLs may serve as an imaging biomarker and a treatment target for OA based on existing clinical trials. [ABSTRACT FROM AUTHOR]

• The neuro-mesenchymal units regulate bone marrow B cell development mainly via the norepinephrine-Cxcl12 pathway. • Targeting these neuro-mesenchymal units not only restored B cell development but also alleviated anxiety-like behavior in the mice. • Anxiety disorders can create a vicious cycle, perpetuating ongoing mental and immunological damage and ultimately leading to irreversible harm. The reduction in B lymphocytes observed in individuals with anxiety disorders may compromise antiviral responses, yet the precise mechanisms behind this decline remain unclear. While elevated glucocorticoid levels have been suggested as contributing factors, anxiety disorders are associated with diminished glucocorticoid signaling. Given that autonomic nervous system dysfunction is a hallmark of anxiety disorders, we established an anxiety-related behavior mouse model by stimulating C1 neurons in the rostral ventrolateral medulla. Using this model, we confirmed that sustained activation of sympathetic nerves can disrupt adaptive immunity, particularly affecting the development of B cells. The underlying mechanism involves the control of B cell development through neuro-mesenchymal units within the bone marrow, with mesenchyme-derived CXCL12 playing a pivotal role in this regulatory process. Intriguingly, targeting these neuro-mesenchymal units not only restored B cell development but also alleviated anxiety-like behavior in the mice. Our study provides compelling evidence regarding the regulatory role of neuro-mesenchymal units in the development of B cells within the bone marrow. Additionally, our findings suggest that anxiety disorders can create a vicious cycle, perpetuating ongoing mental and immunological damage and ultimately leading to irreversible harm. To break this cycle, it is essential to focus on the dysfunction of immune cells and strive to restore immune homeostasis in individuals suffering from anxiety disorders. [ABSTRACT FROM AUTHOR]

Purpose: Obesity increases colon cancer risk that has been previously linked to marrow-derived myeloid cells. We previously demonstrated that exercise training (EX) prevents colon cancer initiation, potentially through reduced myelopoiesis. However, it remains unknown whether early myeloid cell accumulation and inflammation in the colon precedes carcinogenesis with high-fat diet (HFD)-induced obesity, and if EX can attenuate these effects. We hypothesized that obesity would promote colon carcinogenesis that was preceded by myeloid cell accumulation and inflammation that would be attenuated by EX. Methods: C57BL/6 mice were randomized to a HFD or control (CON) diet for 8 weeks. The HFD mice switched to CON diet and all mice were given intraperitoneal injections of azoxymethane (AOM) to induce colon cancer and randomized into EX or sedentary (SED) conditions. Results: HFD mice developed more aberrant crypt foci (ACF), a marker for early carcinogenesis, compared with CON (P < 0.01), and EX developed fewer ACF compared with SED (P < 0.0001). Marrow-derived (P < 0.001) CD206+ macrophages were elevated in HFD compared with CON at study week 16 (P < 0.01). Marrow-derived CD206− macrophages (P < 0.05) and marrow-derived (P < 0.05) CD206+ macrophages were more abundant in HFD compared with CON at study week 42. EX did not alter colon immune cell populations. β-catenin protein was higher in HFD compared with CON at study week 42 (P < 0.05), and STAT3 protein content was lower at study week 28 with EX compared with SED (P < 0.05). Conclusions: The results suggest that obesity promotes colon ACF formation, potentially through early inflammatory myeloid cell accumulation. Despite attenuating ACF, EX did not alter myeloid cell accumulation in the colon, suggesting that EX inhibits ACF formation through alternative mechanisms which may include reduced β-catenin and STAT3 signaling. [ABSTRACT FROM AUTHOR]

Innate training of macrophages can be beneficial for the clearance of pathogens. However, for certain chronic conditions, innate training can have detrimental effects due to an excessive production of pro-inflammatory cytokines. Obesity is a condition that is associated with a range of increased pro-inflammatory training stimuli including the free fatty acid palmitate. Mesenchymal stromal cells (MSCs) are powerful immunomodulators and known to suppress inflammatory macrophages via a range of soluble factors. We show that palmitate training of murine bone-marrow-derived macrophages and human monocyte-derived macrophages (MDMs) results in an increased production of TNFα and IL-6 upon stimulation with lipopolysaccharide and is associated with epigenetic remodeling. Palmitate training led to metabolic changes, however, MSCs did not alter the metabolic profile of human MDMs. Using a transwell system, we demonstrated that human bone marrow MSCs block palmitate training in both murine and human macrophages suggesting the involvement of secreted factors. MSC disruption of the training process occurs through more than one pathway. Suppression of palmitate-enhanced TNFα production is associated with cyclooxygenase-2 activity in MSCs, while secretion of interleukin-1 receptor antagonist by MSCs is required to suppress palmitate-enhanced IL-6 production in MDMs. [Display omitted] • Palmitate drives trained immunity in human macrophages dependent on epigenetic remodeling. • Palmitate training promotes an M2 phenotypic switch with CD206 expression. • MSCs suppress palmitate training pro-inflammatory cytokine production by macrophages. • MSCs do not alter palmitate training-induced M2 phenotypic switch. • MSCs block palmitate training of macrophages via COX-2 and IL-1Ra. [ABSTRACT FROM AUTHOR]

BACKGROUND: Small diameter artificial vessels are urgently needed to treat coronary artery and peripheral artery diseases in clinical practice. At present, vascular tissue engineering has become the main method for preparing small diameter artificial vessels. Selecting suitable biomaterials and cell sources is the key factor for successful construction of small diameter tissue engineered vessels. OBJECTIVE: To observe the effect of four kinds of electrospinning membrane materials on proliferation, adhesion and differentiation of bone marrow mesenchymal stem cells into vascular smooth muscle cells. METHODS: Bone marrow mesenchymal stem cells were isolated and extracted from SD rats. The bone marrow mesenchymal stem cells were inoculated separately on polycaprolactone (PCL), polycaprolactone-hyaluronic acid (PCL-HA), polycaprolactone-silk-filament proteins (PCL-SF), and polycaprolactone- gelatin (PCL-GEL) electrospinning membrane materials. After 1, 3, and 7 days of culture, the cell arrangement on the material was observed under scanning electron microscope. The proliferation and adhesion of the material were observed by phalloidin staining. The mRNA expressions of CD90, Meflin, and transforming growth factor β were detected by qRT-PCR. After 7 days of induced differentiation into vascular smooth muscle cells, the mRNA expression of ɑ-smooth muscle actin on the material was detected by qRT-PCR. RESULTS AND CONCLUSION: (1) Bone marrow mesenchymal stem cells were arranged along the fibers of the four kinds of electrospinning membranes under scanning electron microscopy. (2) Phalloidin staining showed the regular distribution of bone marrow mesenchymal stem cells on the four kinds of electrospinning membranes and parallel distribution along the fiber direction. Moreover, PCL-HA, PCL-SF, and PCL-GEL electrospinning membranes were more conducive to the proliferation and adhesion of bone marrow mesenchymal stem cells than PCL electrospinning membranes. Compared with PCL-HA and PCL-GEL electrospinning membranes, PCL-SF electrospinning membranes were more conducive to the proliferation and adhesion of bone marrow mesenchymal stem cells. (3) qRT-PCR showed that the four kinds of electrospun membrane materials could maintain the mRNA expression of CD90 and Meflin in bone marrow mesenchymal stem cells, but there was no significant difference between groups (P > 0.05). The mRNA expression of transforming growth factor β in PCL-HA, PCL-SF, and PCL-GEL groups was higher than that in PCL group on days 1 and 7 (P < 0.05), and the mRNA expression of transforming growth factor β in PCL-SF group was higher than that in the other three groups on days 3 and 7 (P < 0.05). The mRNA expression of transforming growth factor β in PCL-HA group was higher than that in PCL-GEL group on day 7 (P < 0.05). (4) qRT-PCR showed that the mRNA expression of ɑ-smooth muscle actin in PCL-SF group was higher than that in the other three groups (P < 0.05), and that in PCL-HA group was higher than that in PCL group (P < 0.05). (5) The results indicate that compared with PCL, PCL-HA and PCL-GEL electrospinning membranes, PCL-SF electrospinning membranes combined with bone marrow mesenchymal stem cells are more suitable for the preparation of small diameter tissue engineered vessels. [ABSTRACT FROM AUTHOR]

The immune system is regulated by dendritic cells (DCs), which are highly specialized cells for presenting antigens. They are thought of as natural sentinels that start the immune response triggered by naive T cells against invasive infections. DCs participate in the initial stage of muscle damage in conjunction with monocytes, macrophages, and myogenic cells. The goal of this study was to determine whether DCs might mitigate tissue damage and aid in the regeneration of the gastrocnemius muscle following envenomation with Bothrops jararacussu venom (BjV). Mature bone marrow dendritic cells (BMDCs) were used to treat mice in an experimental envenomation model with BjV by activation with lipopolysaccharide (LPS). BMDCs were injected into the gastrocnemius muscle at the same site of the BjV injury, in a single dose, 3 h after envenomation, and envenoming effects were observed at different periods for 7 days. In both untreated (NT) and treated (T) groups tissue necrosis, leukocyte influx, and hemorrhage at the injury site were observed. Results showed an increase in serum and tissue CK as well as IL-6, TNF-α, and IL-1β release in the first hours after envenoming. In contrast, after treatment with BMDCs results obtained demonstrated an attenuated local effect with a small leukocyte influx, decreased or non-existent necrosis and hemorrhage, as well as a reduction in both serum and tissue CK levels as well as cytokine release and, consequently, the onset of a moderate regenerative process. The present study's findings concluded that BjV causes a severe inflammatory reaction at the site of injury and that treating envenoming with BMDCs in the muscle was crucial for minimizing damage to the muscle and the inflammatory reaction and promoting the early onset of the tissue repair process. • BjV induces myonecrosis and local inflammation. • BMDCs therapy promote muscle regeneration of envenomated animals. • BMDCs played an important role attenuating inflammation and local damage. [ABSTRACT FROM AUTHOR]

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A 31-year-old pregnant woman presented with chest pain, dyspnea, fever, lower extremity swelling, and acute kidney injury. Despite negative infectious disease workup, a diagnosis of idiopathic multicentric Castleman disease (iMCD) was made, specifically the TAFRO subtype. The patient was treated with steroids and siltuximab, showing improvement and renal recovery after 30 days in the hospital. iMCD is a rare syndrome involving lymphadenopathy and cytokine storm, requiring excisional lymph node biopsy for diagnosis and targeting IL-6 for treatment in severe cases. [Extracted from the article]

Automatic detection of Leukemia or blood cancer is one of the most challenging tasks that need to be addressed in the healthcare system. Analysis of white blood cells (WBCs) in the blood or bone marrow microscopic slide images play a crucial part in early identification to facilitate medical experts. For Acute Lymphocytic Leukemia (ALL), the most preferred part of the blood or marrow is to be analyzed by the experts before it spreads in the whole body and the condition becomes worse. The researchers have done a lot of work in this field, to demonstrate a comprehensive analysis few literature reviews have been published focusing on various artificial intelligence-based techniques like machine and deep learning detection of ALL. The systematic review has been done in this article under the PRISMA guidelines which presents the most recent advancements in this field. Different image segmentation techniques were broadly studied and categorized from various online databases like Google Scholar, Science Direct, and PubMed as image processing-based, traditional machine and deep learning-based, and advanced deep learning-based models were presented. Convolutional Neural Networks (CNN) based on traditional models and then the recent advancements in CNN used for the classification of ALL into its subtypes. A critical analysis of the existing methods is provided to offer clarity on the current state of the field. Finally, the paper concludes with insights and suggestions for future research, aiming to guide new researchers in the development of advanced automated systems for detecting life-threatening diseases. [ABSTRACT FROM AUTHOR]

Background: Pediatric sedation clinics are rare in low-income countries. Our aim is to describe the establishment of the first-ever pediatric sedation clinic in Ethiopia and provide an assessment of its safety and efficacy over the 5 years since its establishment. Methods: A multi-phase approach was undertaken. In the first phase, we analyzed barriers to procedural pain management through repeated focus group discussions with stakeholders. Subsequently, we conducted a modified sedation provider course from the Society for Pediatric Sedation (SPS) with pre and post-training testing to document course effectiveness. Finally, we developed a procedural sedation clinic at Tikur Anbessa Specialized Hospital. In the second phase, we prospectively collected outcome data over a 5-year period from patients receiving procedural sedation at the clinic. This included assessing the efficacy of sedation and documenting any adverse events that occurred during the procedures. Result: One hundred three providers completed the procedural sedation course. There was a 13.4% improvement in knowledge between baseline and post-course testing. A total of 2,820 patients underwent procedural sedation over the 5-year period from 2016 through 2021, and data selected from 475 (16.8%) patients were analyzed. The most common procedure performed was bone marrow aspiration/biopsy in 384 subjects (80.8%). The most common procedural sedation used was the combination of ketamine and propofol in 60.6%. The mean pain score during the procedure was 0.28/10, which was significantly lower than the pre-procedural pain score (p-value < 0.001). A total of 9 (1.9%) patients had adverse events and there was no mortality. Conclusion: Based on our experience, development of a safe and effective sedation clinic is possible in resource-limited settings as evidenced by low procedural pain scores, and low adverse events rates. Provider training based on a modification of the SPS course improved overall procedural sedation knowledge. [ABSTRACT FROM AUTHOR]

Introduction: Bone marrow-derived mesenchymal stem cell-derived extracellular vesicles (BMSC-EVs) are widely used for therapeutic purposes in preclinical studies. However, their utility in treating diabetes-associated atherosclerosis remains largely unexplored. Here, we aimed to characterize BMSC-EV-mediated regulation of autophagy and macrophage polarization. Methods: EVs were isolated from the supernatant of cultured BMSCs and characterized with transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), and western blotting. A diabetes-related atherosclerotic ApoE−/− mouse model was established through feeding with a high-fat diet (HFD) and streptozotocin (STZ). Histopathological analyses were carried out using Oil Red O, H&E, and Masson staining of the aorta. TEM and immunohistochemistry (IHC) were applied to evaluate autophagy, and immunofluorescence (IF) was used to identify macrophage polarization. RAW264.7 macrophages were induced with oxidized low-density lipoprotein (ox-LDL) and high glucose (HG), co-cultured with BMSC-EVs, and analyzed for macrophage proliferation, migration, and foam cell formation. RAW264.7 cells were transduced with autophagy marker mRFP-GFP-LC3 lentivirus and analyzed with IF and western blotting. Results: Diabetic mice (DA group) had larger aortic plaque areas and lower collagen content than the HFD mice. BMSC-EV treatment significantly reduced blood glucose, LDL levels, and aortic plaque areas while increasing collagen content. BMSC-EV-treated aortas contained a higher number of autophagosomes/autolysosomes, with increased expression of LC3BII correlating with decreased P62 levels and a lower proportion of M1 macrophages. In vitro, BMSC-EVs inhibited proliferation, migration, and foam cell formation in ox-LDL and HG-induced activated RAW264.7 cells. These effects were reversed by the autophagy blocker bafilomycin A1. Consistent with the in vivo findings, BMSC-EVs elevated levels of the autophagy-related protein LC3BII/I and decreased P62 in ox-LDL and HG-induced RAW264.7 cells. These cells also expressed the M1 macrophage markers CD86 and iNOS, but showed reduced expression of the M2 marker Arg-1. Further, BMSC-EVs decreased AMPKα and mTOR phosphorylation levels, which were blocked by the AMPK inhibitor compound C. Conclusions: BMSC-EVs attenuate diabetes-exacerbated atherosclerosis by inhibiting vascular macrophage proliferation, migration, and foam cell formation via AMPK/mTOR signaling-regulated autophagy and macrophage polarization. BMSC-EVs thus hold promise as therapeutic agents for atherosclerosis. Extracellular vesicles derived from bone marrow mesenchymal stem cells may mitigate diabetes-aggravated atherosclerosis by regulating AMPK/mTOR-mediated autophagy-related macrophage polarization and inhibiting macrophage proliferation, migration, foam cell formation, and cholesterol transport. [ABSTRACT FROM AUTHOR]

Toll-like receptor (TLRs) activation in multiple myeloma (MM) cells induces heterogeneous functional responses including cell growth and proliferation, survival or apoptosis. These effects have been suggested to be partly due to increase in secretion of cytokines such as IL-6 or IFNα among others from MM cells following TLR activation. However, whether triggering of these receptors also modulates production of immunoglobulin free light chains (FLCs), which largely contribute to MM pathology, has not been investigated in MM cells before. This study explored the effect of TLR1/2 ligand (Pam3CSK4) alone or combined with bortezomib (BTZ) on production of FLCs in human myeloma cell lines, L363, OPM-2, U266 and NCI-H929. It also investigated the above effect when MM cells were exposed to bone marrow stromal cells (BMSCs) or fibronectin (FN). Adhesion to BMSCs or FN increased secretion of FLC in MM cells. Pam3CSK4 decreased FLC production, and this effect was enhanced in combination with BTZ but attenuated when MM cells adhered to BMSCs or FN. The findings of this study imply that activation of TLR1/2 downregulates FLC production in MM cells even in the context of bone marrow microenvironment components and suggest that targeting some TLRs such as TLR1/2 might have therapeutic potential. [ABSTRACT FROM AUTHOR]