An IL-4 signalling axis in bone marrow drives pro-tumorigenic myelopoiesis.

Myeloid cells are known to suppress antitumour immunity1. However, the molecular drivers of immunosuppressive myeloid cell states are not well defined. Here we used single-cell RNA sequencing of human and mouse non-small cell lung cancer (NSCLC) lesions, and found that in both species the type 2 cytokine interleukin-4 (IL-4) was predicted to be the primary driver of the tumour-infiltrating monocyte-derived macrophage phenotype. Using a panel of conditional knockout mice, we found that only deletion of the IL-4 receptor IL-4Rα in early myeloid progenitors in bone marrow reduced tumour burden, whereas deletion of IL-4Rα in downstream mature myeloid cells had no effect. Mechanistically, IL-4 derived from bone marrow basophils and eosinophils acted on granulocyte-monocyte progenitors to transcriptionally programme the development of immunosuppressive tumour-promoting myeloid cells. Consequentially, depletion of basophils profoundly reduced tumour burden and normalized myelopoiesis. We subsequently initiated a clinical trial of the IL-4Rα blocking antibody dupilumab2-5 given in conjunction with PD-1/PD-L1 checkpoint blockade in patients with relapsed or refractory NSCLC who had progressed on PD-1/PD-L1 blockade alone (ClinicalTrials.gov identifier NCT05013450 ). Dupilumab supplementation reduced circulating monocytes, expanded tumour-infiltrating CD8 T cells, and in one out of six patients, drove a near-complete clinical response two months after treatment. Our study defines a central role for IL-4 in controlling immunosuppressive myelopoiesis in cancer, identifies a novel combination therapy for immune checkpoint blockade in humans, and highlights cancer as a systemic malady that requires therapeutic strategies beyond the primary disease site.

Thallium exposure induces changes in B and T cell generation in mice.

Thallium (Tl) is a high-priority toxic metal that poses a severe threat to human health. The toxicity characteristics induced by Tl have been partially discussed. However, the immunotoxic effects of Tl exposure have remained largely unexplored. Our findings demonstrated that 50 ppm of Tl exposure for one week induced severe weight loss in mice, which was accompanied by appetite suppression. Moreover, although Tl exposure did not induce significant pathological damage to skeletal muscle and bone, Tl inhibited the expression of B cell development-related genes in the bone marrow. Additionally, Tl exposure increased B cell apoptosis and reduced its generation in the bone marrow. Analysis of B cells in the blood indicated that the percentage of B-2 cells decreased significantly, whereas B-2 cell proportions in the spleen did not. The percentage of CD4+ T cells in the thymus increased significantly, and the proportion of CD8+ T cells did not. Furthermore, although the proportion of the total CD4+ and CD8+ T cells was not significantly altered in the blood and spleen, Tl exposure promoted the migration of naïve CD4+ T cells and recent thymic emigrants (RTEs) from the thymus to the spleen. These results suggest that Tl exposure can affect B and T cell generation and migration, which provides new evidence for Tl-induced immunotoxicity.

Acute hepatitis-like presentation with cholestasis of CBFB-MYH11-positive acute myeloid leukemia in an adult male: a case report.

BACKGROUND: Liver involvement in adults with acute myeloid leukemia is uncommon. Most of the case reports describe acute liver failure or obstructive jaundice, while acute hepatitis is rarely mentioned. We report a patient with acute myeloid leukemia who presented with clinical, biochemical, and radiological signs of acute hepatitis that totally regressed after chemotherapy. CASE PRESENTATION: A 38-year-old Caucasian man presented with fever, cough, and mild fatigue. Laboratory workup showed anemia, thrombocytopenia, severe leukocytosis, transaminitis, and hyperbilirubinemia. Imaging of the abdomen (ultrasound and magnetic resonance) showed hepatomegaly, splenomegaly, upper limits portal veins diameters, increased thickness of the gallbladder wall, and significant abdominal lymph nodes. Peripheral blood smear and bone marrow evaluation were consistent with acute myeloid leukemia, and liver biopsy showed massive sinusoidal and portal infiltration by leukemic cells. After remission-inducing chemotherapy, there was complete normalization of liver function tests, and liver, spleen, and portal vein size. CONCLUSIONS: This case highlights the importance of taking acute myeloid leukemia into account as a possible cause of liver damage to make a rapid diagnosis and start appropriate treatment that may lead to hematological remission and hepatic dysfunction resolution.

Stimulating the Hematopoietic Effect of Simulated Digestive Product of Fucoidan from Sargassum fusiforme on Cyclophosphamide-Induced Hematopoietic Damage in Mice and Its Protective Mechanisms Based on Serum Lipidomics.

Hematopoietic damage is a serious side effect of cytotoxic drugs, and agents promoting hematopoiesis are quite important for decreasing the death rate in cancer patients. In our previous work, we prepared the simulated digestive product of fucoidan from Sargassum fusiforme, DSFF, and found that DSFF could activate macrophages. However, more investigations are needed to further evaluate whether DSFF could promote hematopoiesis in the chemotherapy process. In this study, the protective effect of DSFF (1.8-7.2 mg/kg, i.p.) on cyclophosphamide-induced hematopoietic damage in mice and the underlying mechanisms were investigated. Our results show that DSFF could restore the numbers of white blood cells, neutrophils, and platelets in the peripheral blood, and could also retard bone marrow cell decrease in mice with cyclophosphamide-induced hematopoietic damage. UPLC/Q-Extraction Orbitrap/MS/MS-based lipidomics results reveal 16 potential lipid biomarkers in a serum that responded to hematopoietic damage in mice. Among them, PC (20:1/14:0) and SM (18:0/22:0) were the key lipid molecules through which DSFF exerted protective actions. In a validation experiment, DSFF (6.25-100 µg/mL) could also promote K562 cell proliferation and differentiation in vitro. The current findings indicated that DSFF could affect the blood cells and bone marrow cells in vivo and thus showed good potential and application value in alleviating the hematopoietic damage caused by cyclophosphamide.

The Effect of Low Doses of Zearalenone (ZEN) on the Bone Marrow Microenvironment and Haematological Parameters of Blood Plasma in Pre-Pubertal Gilts.

The aim of this study was to determine whether low doses of zearalenone (ZEN) influence the carry-over of ZEN and its metabolites to the bone marrow microenvironment and, consequently, haematological parameters. Pre-pubertal gilts (with a body weight of up to 14.5 kg) were exposed to daily ZEN doses of 5 µg/kg BW (group ZEN5, n = 15), 10 µg/kg BW (group ZEN10, n = 15), 15 µg/kg BW (group ZEN15, n = 15), or were administered a placebo (group C, n = 15) throughout the entire experiment. Bone marrow was sampled on three dates (exposure dates 7, 21, and 42-after slaughter) and blood for haematological analyses was sampled on 10 dates. Significant differences in the analysed haematological parameters (WBC White Blood Cells, MONO-Monocytes, NEUT-Neutrophils, LYMPH-Lymphocytes, LUC-Large Unstained Cells, RBC-Red Blood Cells, HGB-Haemoglobin, HCT-Haematocrit, MCH-Mean Corpuscular Volume, MCHC-Mean Corpuscular Haemoglobin Concentrations, PLT-Platelet Count and MPV-Mean Platelet Volume) were observed between groups. The results of the experiment suggest that exposure to low ZEN doses triggered compensatory and adaptive mechanisms, stimulated the local immune system, promoted eryptosis, intensified mycotoxin biotransformation processes in the liver, and produced negative correlations between mycotoxin concentrations and selected haematological parameters.

Latency reversal plus natural killer cells diminish HIV reservoir in vivo.

HIV is difficult to eradicate due to the persistence of a long-lived reservoir of latently infected cells. Previous studies have shown that natural killer cells are important to inhibiting HIV infection, but it is unclear whether the administration of natural killer cells can reduce rebound viremia when anti-retroviral therapy is discontinued. Here we show the administration of allogeneic human peripheral blood natural killer cells delays viral rebound following interruption of anti-retroviral therapy in humanized mice infected with HIV-1. Utilizing genetically barcoded virus technology, we show these natural killer cells efficiently reduced viral clones rebounding from latency. Moreover, a kick and kill strategy comprised of the protein kinase C modulator and latency reversing agent SUW133 and allogeneic human peripheral blood natural killer cells during anti-retroviral therapy eliminated the viral reservoir in a subset of mice. Therefore, combinations utilizing latency reversal agents with targeted cellular killing agents may be an effective approach to eradicating the viral reservoir.

Azacitidine-induced reconstitution of the bone marrow T cell repertoire is associated with superior survival in AML patients.

Hypomethylating agents (HMA) like azacitidine are licensed for the treatment of acute myeloid leukemia (AML) patients ineligible for allogeneic hematopoietic stem cell transplantation. Biomarker-driven identification of HMA-responsive patients may facilitate the choice of treatment, especially in the challenging subgroup above 60 years of age. Since HMA possesses immunomodulatory functions that constitute part of their anti-tumor effect, we set out to analyze the bone marrow (BM) immune environment by next-generation sequencing of T cell receptor beta (TRB) repertoires in 51 AML patients treated within the RAS-AZIC trial. Patients with elevated pretreatment T cell diversity (11 out of 41 patients) and those with a boost of TRB richness on day 15 after azacitidine treatment (12 out of 46 patients) had longer event-free and overall survival. Both pretreatment and dynamic BM T cell metrics proved to be better predictors of outcome than other established risk factors. The favorable broadening of the BM T cell space appeared to be driven by antigen since these patients showed significant skewing of TRBV gene usage. Our data suggest that one course of AZA can cause reconstitution to a more physiological T cell BM niche and that the T cell space plays an underestimated prognostic role in AML.Trial registration: DRKS identifier: DRKS00004519.

Effects of Alendronate and Dexamethasone on Osteoclast Gene Expression and Bone Resorption in Mouse Marrow Cultures.

Osteoclasts are cells whose main function is the resorption of bone matrix. However, several factors, including medications, can interfere with the resorption process. Alendronate (ALN), a nitrogen-containing type of bisphosphonate, and dexamethasone (DEX), a glucocorticoid, are drugs that may affect the resorption activity. The aim of this study is to investigate the effects of ALN, and/or DEX on osteoclast gene expression and resorption activity in primary mouse marrow cultures stimulated with 1,25-dihydroxyvitamin D3, a model for the bone microenvironment. Cultures were treated only with ALN (10-5 M), DEX (10-6 M), and with a combination of both agents. Viability assays performed at days 5, 7, and 9 showed the highest number of viable cells at day 7. All the following assays were then performed at day 7 of cell culture: tartrate resistant acid phosphatase (TRAP) histochemistry, receptor activator of nuclear factor kappa B ligand (RANKL) immunofluorescence, osteoprotegerin (OPG), and RANKL gene expression by qPCR and resorption analysis by scanning electron microscopy. Treatment with ALN, DEX, and the combination of both did not promote significant changes in the number of TRAP+ cells, although larger giant cells were detected in groups treated with DEX. DEX treatment increased the gene expression of RANKL and reduced OPG. The treatment with ALN reduced the depth of the resorption pits, but their inhibitory effect was less effective when administered with DEX.

Glucocorticoid Production in Lymphoid Organs: Acute Effects of Lipopolysaccharide in Neonatal and Adult Mice.

Glucocorticoids (GCs) are critical modulators of the immune system. The hypothalamic-pituitary-adrenal (HPA) axis regulates circulating GC levels and is stimulated by endotoxins. Lymphoid organs also produce GCs; however, it is not known how lymphoid GC levels are regulated in response to endotoxins. We assessed whether an acute challenge of lipopolysaccharide (LPS) increases lymphoid levels of progesterone and GCs, and expression of steroidogenic enzymes and key HPA axis components (eg, corticotropin-releasing hormone [CRH], adrenocorticotropic hormone [ACTH]). We administered LPS (50 µg/kg intraperitoneally) or vehicle control to male and female C57BL/6J neonatal (postnatal day [PND] 5) and adult (PND90) mice and collected blood, bone marrow, thymus, and spleen 4 hours later. We measured progesterone, 11-deoxycorticosterone, corticosterone, and 11-dehydrocorticosterone via liquid chromatography-tandem mass spectrometry. We measured gene expression of key steroidogenic enzymes (Cyp11b1, Hsd11b1, and Hsd11b2) and HPA axis components (Crh, Crhr1, Pomc, and Mc2r) via quantitative polymerase chain reaction. At PND5, LPS induced greater increases in steroid levels in lymphoid organs than in blood. In contrast, at PND90, LPS induced greater increases in steroid levels in blood than in lymphoid organs. Steroidogenic enzyme transcripts were present in all lymphoid organs, and LPS altered steroidogenic enzyme expression predominantly in the spleen. Lastly, we detected transcripts of key HPA axis components in all lymphoid organs, and there was an effect of LPS in the spleen. Taken together, these data suggest that LPS regulates GC production by lymphoid organs, similar to its effects on the adrenal glands, and the effects of LPS might be mediated by local expression of CRH and ACTH.

Management of Breast Cancer Patients During the Coronavirus Disease 2019 Pandemic: The Experience From the Epicenter of China, Wuhan.

BACKGROUND: The coronavirus disease 2019 pandemic is a global public health event. Wuhan used to be the epicenter of China and finally controlled the outbreak through city lockdown and many other policies. However, the pandemic and the prevention strategies had a huge impact on the medical care procedures for patients with breast cancer, leading to the delay or interruption of anticancer therapies. PATIENTS AND METHODS: To better serve patients with breast cancer under the premise of epidemic control, many strategies have been proposed and optimized in our center. One of the most important parts of these strategies is the promotion of telemedicine, including online consultation, online prescription, and drug mailing services. RESULTS: In keeping with the city and hospital policies, we have also introduced stricter ward management policies and more precise care. CONCLUSION: Here, we collected the diagnosis and treatment process of patients with breast cancer in our center during the coronavirus disease 2019 pandemic, which was found to be correlated to a reduction in chemotherapy-related myelosuppression and hepatic dysfunction, hoping to provide a reference for other cancer centers that may suffer from the similar situation.

Olive oil effectively mitigates ovariectomy-induced marrow adiposity assessed by MR spectroscopy in estrogen-deficient rabbits.

BACKGROUND: Polyphenols in extra virgin olive oil (EVOO) have been found to reduce the expression of PPARγ2, inhibit adipocyte differentiation, and enhance the formation of osteoblasts from bone marrow stem cells. However, the underlying mechanisms of their action remain unknown. PURPOSE: To determine the sequential effects of EVOO on marrow fat expansion induced by estrogen deprivation using 3.0-T proton magnetic resonance (MR) spectroscopy in an ovariectomy (OVX) rabbit model of postmenopausal bone loss over a six-month period. MATERIAL AND METHODS: A total of 45 female New Zealand rabbits were equally divided into sham-operation, OVX controls, and OVX treated with EVOO for six months. Marrow fat fraction was measured by MR spectroscopy at baseline conditions, and three and six months postoperatively, respectively. Serum bone biomarkers, lumbar and femoral bone mineral density, microtomographic parameters, biomechanical properties, and quantitative parameters of marrow adipocytes were studied. RESULTS: OVX was associated with marrow adiposity in a time-dependent manner, accompanied with increased bone turnover and impaired bone mass and trabecular microarchitecture. In OVX rabbits, EVOO markedly alleviated trabecular bone loss and reduced the accumulation of lipid droplets including adipocyte size, density, and areas of fat deposits in the bone marrow. EVOO prevented such changes in terms of both marrow adiposity and bone remodeling. CONCLUSION: Early EVOO treatment may exert beneficial effects on bone by modulating marrow adiposity, which would support their protective effect against bone pathologies.

Oncostatin M regulates hematopoietic stem cell (HSC) niches in the bone marrow to restrict HSC mobilization.

We show that pro-inflammatory oncostatin M (OSM) is an important regulator of hematopoietic stem cell (HSC) niches in the bone marrow (BM). Treatment of healthy humans and mice with granulocyte colony-stimulating factor (G-CSF) dramatically increases OSM release in blood and BM. Using mice null for the OSM receptor (OSMR) gene, we demonstrate that OSM provides a negative feed-back acting as a brake on HSPC mobilization in response to clinically relevant mobilizing molecules G-CSF and CXCR4 antagonist. Likewise, injection of a recombinant OSM molecular trap made of OSMR complex extracellular domains enhances HSC mobilization in poor mobilizing C57BL/6 and NOD.Cg-PrkdcscidIl2rgtm1Wjl/SzJ mice. Mechanistically, OSM attenuates HSC chemotactic response to CXCL12 and increases HSC homing to the BM signaling indirectly via BM endothelial and mesenchymal cells which are the only cells expressing OSMR in the BM. OSM up-regulates E-selectin expression on BM endothelial cells indirectly increasing HSC proliferation. RNA sequencing of HSCs from Osmr-/- and wild-type mice suggest that HSCs have altered cytoskeleton reorganization, energy usage and cycling in the absence of OSM signaling in niches. Therefore OSM is an important regulator of HSC niche function restraining HSC mobilization and anti-OSM therapy combined with current mobilizing regimens may improve HSPC mobilization for transplantation.

Gene Expression Profiles Identify Biomarkers of Resistance to Decitabine in Myelodysplastic Syndromes.

Myelodysplastic syndrome (MDS) is a clonal hematopoietic stem cell disease characterized by inefficient hematopoiesis and the potential development of acute leukemia. Among the most notable advances in the treatment of MDS is the hypomethylating agent, decitabine (5-aza-2'deoxycytidine). Although decitabine is well known as an effective method for treating MDS patients, only a subset of patients respond and a tolerance often develops, leading to treatment failure. Moreover, decitabine treatment is costly and causes unnecessary toxicity. Therefore, clarifying the mechanism of decitabine resistance is important for improving its therapeutic efficacy. To this end, we established a decitabine-resistant F-36P cell line from the parental F-36P leukemia cell line, and applied a genetic approach employing next-generation sequencing, various experimental techniques, and bioinformatics tools to determine differences in gene expression and relationships among genes. Thirty-eight candidate genes encoding proteins involved in decitabine-resistant-related pathways, including immune checkpoints, the regulation of myeloid cell differentiation, and PI3K-Akt signaling, were identified. Interestingly, two of the candidate genes, AKT3 and FOS, were overexpressed in MDS patients with poor prognoses. On the basis of these results, we are pursuing development of a gene chip for diagnosing decitabine resistance in MDS patients, with the goal of ultimately improving the power to predict treatment strategies and the prognosis of MDS patients.

Hematogones with light chain restriction: A potential diagnostic pitfall when using flow cytometry analysis to assess bone marrow specimens.

Light-chain restricted hematogones (LCR HGs) detected by flow cytometry analysis can mimic bone marrow involvement by B-cell lymphoma. This phenomenon can present a diagnostic pitfall and negatively impact patient management, as misinterpretation may upgrade disease stage. In this study, we characterized the immunophenotype of LCR HGs with an aim to differentiate them from B-cell lymphoma. We analyzed 24 patients with LCR HGs, 12 (50 %) were kappa light chain restricted and 12 (50 %) were lambda light chain restricted. LCR HGs account for 51 % (range, 1.5%-99%) of B cells, and 0.5 % (range, 0.1%-3.7%) of total cells. In 15 patients in whom multiple specimens were analyzed, 10 (67 %) showed persistent LCR HGs in more than 1 specimen, and the duration of the light chain restriction ranged from 4 months to 2 years. Among 24 patients, 4 (16.6 %) cases were concurrently involved by B-cell lymphoma/myeloma in addition to LCR HGs. With the exception of light chain restriction, LCR HGs showed a similar immunophenotype as normal HGs and had a distinct location on the CD45/Side Scatter (SSC) plot. They were also consistently positive for CD10, CD19, CD38 (bright), CD43, and CD200. CD20 expression showed a spectrum from dim/negative to positive.

Allium sativum aqueous extract does not have chemo-protective effect on etoposide induced therapy-related DNA damage leading to Acute Myeloid Leukemia in albino-wistar rats.

BACKGROUND: Therapy-related acute myeloid leukemia (t-AML) is a well-recognized clinical syndrome occurring in a significant fraction of patients who have undergone previous chemotherapy for a solid tumour. OBJECTIVES: We aim to evaluate the effect of aqueous extract of fresh Allium sativum cloves on haematological parameters, bone marrow and DNA of etoposide treated albino wistar rats. Decoction method was used to prepare plant extracts and the rats were weighed and divided into experimental and control groups. Blood and bone marrow sample were analysed and DNA fragment analysis was carried out. RESULTS: There was progressive increase in the weight of animals that received distilled water only for the duration of the experiment while those that received etoposide only showed a sharp decrease in weight by the end of week 3. There was no significant difference in the mean of the haematological parameters in the test and control groups except for platelet count. The bone marrow smears showed no prevention of erythroblast fragmentation by the extract, in the same vein, DNA damage was not abated. CONCLUSION: Aqueous extract of fresh Allium sativum cloves may not be the option for the prevention of etoposide induced acute myeloid leukemia.

Subclone-specific microenvironmental impact and drug response in refractory multiple myeloma revealed by single-cell transcriptomics.

Virtually all patients with multiple myeloma become unresponsive to treatment over time. Relapsed/refractory multiple myeloma (RRMM) is accompanied by the clonal evolution of myeloma cells with heterogeneous genomic aberrations and profound changes of the bone marrow microenvironment (BME). However, the molecular mechanisms that drive drug resistance remain elusive. Here, we analyze the heterogeneous tumor cell population and its complex interaction network with the BME of 20 RRMM patients by single cell RNA-sequencing before/after treatment. Subclones with chromosome 1q-gain express a specific transcriptomic signature and frequently expand during treatment. Furthermore, RRMM cells shape an immune suppressive BME by upregulation of inflammatory cytokines and close interaction with the myeloid compartment. It is characterized by the accumulation of PD1+ γδ T-cells and tumor-associated macrophages as well as the depletion of hematopoietic progenitors. Thus, our study resolves transcriptional features of subclones in RRMM and mechanisms of microenvironmental reprogramming with implications for clinical decision-making.

Anti Thymocyte Globulin-Based Treatment for Acquired Bone Marrow Failure in Adults.

Idiopathic acquired aplastic anemia can be successfully treated with Anti Thymocyte Globulin (ATG)-based immune suppressive therapy and is therefore considered a T cell-mediated auto immune disease. Based on this finding, several other forms of idiopathic acquired bone marrow failure are treated with ATG as well. For this review, we extensively searched the present literature for evidence that ATG can lead to enduring remissions in different forms of acquired multi- or single-lineage bone marrow failure. We conclude that ATG-based therapy can lead to an enduring hematopoietic response and increased overall survival (OS) in patients with acquired aplastic aplasia. In patients with hypocellular myelodysplastic syndrome, ATG can lead to a hematological improvement without changing the OS. ATG seems less effective in acquired single-lineage failure diseases like Pure Red Cell Aplasia, Amegakaryocytic Thrombocytopenia and Pure White Cell Aplasia, suggesting a different pathogenesis in these bone marrow failure states compared to aplastic anemia. T cell depletion is hypothesized to play an important role in the beneficial effect of ATG but, as ATG is a mixture of polyclonal antibodies binding to different antigens, other anti-inflammatory or immunomodulatory effects could play a role as well.

Chondroitin Sulfate Alleviates Diabetic Osteoporosis and Repairs Bone Microstructure via Anti-Oxidation, Anti-Inflammation, and Regulating Bone Metabolism.

Diabetic osteoporosis (DOP) belongs to secondary osteoporosis caused by diabetes; it has the characteristics of high morbidity and high disability. In the present study, we constructed a type 1 diabetic rat model and administered chondroitin sulfate (200 mg/kg) for 10 weeks to observe the preventive effect of chondroitin sulfate on the bone loss of diabetic rats. The results showed that chondroitin sulfate can reduce blood glucose and relieve symptoms of diabetic rats; in addition, it can significantly increase the bone mineral density, improve bone microstructure, and reduce bone marrow adipocyte number in diabetic rats; after 10 weeks of chondroitin sulfate administration, the SOD activity level was upregulated, as well as CAT levels, indicating that chondroitin sulfate can alleviate oxidative stress in diabetic rats. Chondroitin sulfate was also found to reduce the level of serum inflammatory cytokines (TNF-α, IL-1, IL-6, and MCP-1) and alleviate the inflammation in diabetic rats; bone metabolism marker detection results showed that chondroitin sulfate can reduce bone turnover in diabetic rats (decreased RANKL, CTX-1, ALP, and TRACP 5b levels were observed after 10 weeks of chondroitin sulfate administration). At the same time, the bone OPG and RUNX 2 expression levels were higher after chondroitin sulfate treatment, the bone RANKL expression was lowered, and the OPG/RANKL ratio was upregulated. All of the above indicated that chondroitin sulfate could prevent STZ-induced DOP and repair bone microstructure; the main mechanism was through anti-oxidation, anti-inflammatory, and regulating bone metabolism. Chondroitin sulfate could be used to develop anti-DOP functional foods and diet interventions for diabetes.

Three dimensional and microphysiological bone marrow models detect in vivo positive compounds.

Micronucleus (MN) assessment is a valuable tool in safety assessment. However, several compounds are positive in the in vivo bone marrow (BM) MN assay but negative in vitro, reflecting that BM complexity is not recapitulated in vitro. Importantly, these compounds are not genotoxic; rather, drug-driven pharmacological-effects on the BM increase MN, however, without mechanistic understanding, in vivo positives stop drug-progression. Thus, physiologically-relevant BM models are required to bridge the gap between in vitro and in vivo. The current study aimed to investigate the utility of two human 3D BM models (fluidic and static) for MN assessment. MN induction following treatment with etoposide and Poly-ADP Ribose Polymerase inhibitor (PARPi) and prednisolone (negative in vitro, positive in vivo) was determined in 2D L5178Y and human BM cells, and the 3D BM models. Etoposide (0-0.070 µM) and PARPi (0-150 µM) induced MN in both 3D BM models indicating their utility for genotoxicity testing. Interestingly, PARPi treatment induced a MN trend in 3D more comparable to in vivo. Importantly, prednisolone (0-1.7 mM) induced MN in both 3D BM models, suggesting recapitulation of the in vivo microenvironment. These models could provide a valuable tool to follow up, and eventually predict, suspected pharmacological mechanisms, thereby reducing animal studies.