Independent origins of fetal liver haematopoietic stem and progenitor cells.

Self-renewal and differentiation are tightly controlled to maintain haematopoietic stem cell (HSC) homeostasis in the adult bone marrow1,2. During fetal development, expansion of HSCs (self-renewal) and production of differentiated haematopoietic cells (differentiation) are both required to sustain the haematopoietic system for body growth3,4. However, it remains unclear how these two seemingly opposing tasks are accomplished within the short embryonic period. Here we used in vivo genetic tracing in mice to analyse the formation of HSCs and progenitors from intra-arterial haematopoietic clusters, which contain HSC precursors and express the transcription factor hepatic leukaemia factor (HLF). Through kinetic study, we observed the simultaneous formation of HSCs and defined progenitors-previously regarded as descendants of HSCs5-from the HLF+ precursor population, followed by prompt formation of the hierarchical haematopoietic population structure in the fetal liver in an HSC-independent manner. The transcription factor EVI1 is heterogeneously expressed within the precursor population, with EVI1hi cells being predominantly localized to intra-embryonic arteries and preferentially giving rise to HSCs. By genetically manipulating EVI1 expression, we were able to alter HSC and progenitor output from precursors in vivo. Using fate tracking, we also demonstrated that fetal HSCs are slowly used to produce short-term HSCs at late gestation. These data suggest that fetal HSCs minimally contribute to the generation of progenitors and functional blood cells before birth. Stem cell-independent pathways during development thus offer a rational strategy for the rapid and simultaneous growth of tissues and stem cell pools.

Landscape of driver mutations and their clinical effects on Down syndrome-related myeloid neoplasms.

ABSTRACT: Transient abnormal myelopoiesis (TAM) is a common complication in newborns with Down syndrome (DS). It commonly progresses to myeloid leukemia (ML-DS) after spontaneous regression. In contrast to the favorable prognosis of primary ML-DS, patients with refractory/relapsed ML-DS have poor outcomes. However, the molecular basis for refractoriness and relapse and the full spectrum of driver mutations in ML-DS remain largely unknown. We conducted a genomic profiling study of 143 TAM, 204 ML-DS, and 34 non-DS acute megakaryoblastic leukemia cases, including 39 ML-DS cases analyzed by exome sequencing. Sixteen novel mutational targets were identified in ML-DS samples. Of these, inactivations of IRX1 (16.2%) and ZBTB7A (13.2%) were commonly implicated in the upregulation of the MYC pathway and were potential targets for ML-DS treatment with bromodomain-containing protein 4 inhibitors. Partial tandem duplications of RUNX1 on chromosome 21 were also found, specifically in ML-DS samples (13.7%), presenting its essential role in DS leukemia progression. Finally, in 177 patients with ML-DS treated following the same ML-DS protocol (the Japanese Pediatric Leukemia and Lymphoma Study Group acute myeloid leukemia -D05/D11), CDKN2A, TP53, ZBTB7A, and JAK2 alterations were associated with a poor prognosis. Patients with CDKN2A deletions (n = 7) or TP53 mutations (n = 4) had substantially lower 3-year event-free survival (28.6% vs 90.5%; P < .001; 25.0% vs 89.5%; P < .001) than those without these mutations. These findings considerably change the mutational landscape of ML-DS, provide new insights into the mechanisms of progression from TAM to ML-DS, and help identify new therapeutic targets and strategies for ML-DS.

Adiponectin Enhances Antibacterial Activity of Hematopoietic Cells by Suppressing Bone Marrow Inflammation.

Obesity has been shown to increase the morbidity of infections, however, the underlying mechanisms remain largely unknown. Here we demonstrate that obesity caused adiponectin deficiency in the bone marrow (BM), which led to an inflamed BM characterized by increased tumor necrosis factor (TNF) production from bone marrow macrophages. Hematopoietic stem and progenitor cells (HSPCs) chronically exposed to excessive TNF in obese marrow aberrantly expressed cytokine signaling suppressor SOCS3, impairing JAK-STAT mediated signal transduction and cytokine-driven cell proliferation. Accordingly, both obese and adiponectin-deficient mice showed attenuated clearance of infected Listeria monocytogenes, indicating that obesity or loss of adiponectin is critical for exacerbation of infection. Adiponectin treatment restored the defective HSPC proliferation and bacterial clearance of obese and adiponectin-deficient mice, affirming the importance of adiponectin against infection. Taken together, our findings demonstrate that obesity impairs hematopoietic response against infections through a TNF-SOCS3-STAT3 axis, highlighting adiponectin as a legitimate target against obesity-related infections.

Association between longitudinal changes in striatal dopamine transporter uptake and clinical features of dementia with Lewy bodies.

BACKGROUND: It is widely known that there is low striatal 123 I-2ß-Carbomethoxy-3ß-(4-iodophenyl)-N-(3- fluoropropyl) nortropane (123 I-FP-CIT) dopamine transporter single photon emission tomography (DaT-SPECT) uptake in patients with dementia with Lewy bodies (DLB). No studies to date have analyzed the association between longitudinal changes of clinical features and DaT uptake in patients with Parkinson syndrome, particularly those with DLB. The aim of this study was to investigate the association between the longitudinal changes in DaT uptake and the severity of parkinsonism and cognitive function in DLB patients. METHODS: A total of 35 outpatients with probable DLB who underwent DaT-SPECT twice (at the initial examination and the follow-up period) in the Memory Disorder Clinic at the Department of Geriatric Medicine, Tokyo Medical University, were enrolled in this study between April 2014 and September 2020. The correlation between annual changes in DaT uptake and clinical features (cognitive function decline and parkinsonism) of the patients was analyzed. RESULTS: A significant correlation was detected between annual changes in parkinsonism symptom severity and DaT uptake in the left posterior putamen (r = -0.39, P = 0.03), and between Mini-Mental State Examination scores and DaT uptake in all regions except the right posterior putamen (P < 0.05) in patients with DLB. CONCLUSIONS: Our results suggested that the pathway from the ventrolateral tier of the substantia nigra to the putamen might be more crucial for motor function than other pathways, not only in Parkinson's disease but also in DLB.

Isolated Bone Recurrence of Medulloblastoma With MYCN Amplification and TP53 Loss: A Case Report.

Extraneural recurrence of a medulloblastoma is rare with dismal prognosis. A 9-year-old girl with medulloblastoma was treated with gross total resection followed by a combination of chemotherapy and radiotherapy. Fourteen months after treatment completion, she developed multifocal bone metastases. Despite chemotherapy combined with irradiation, she died 18 months after recurrence due to progressive disease. Fluorescence in situ hybridization on formalin-fixed paraffin-embedded tissue sections revealed MYCN amplification and TP53 loss, consistent with the genetic alterations of a rapidly progressive subgroup of recurrent medulloblastomas. In clinical practice, dismal biologic features can be determined using fluorescence in situ hybridization in defective materials.

Biomarkers associated with coronary high-risk plaques.

Vascular inflammation, lipid metabolism, and thrombogenicity play a key role not only in atherogenesis but also in the development of acute coronary syndromes. Biomarkers associated with coronary high-risk plaques defined according to intravascular imaging have not been systematically studied. A total of 69 patients with coronary artery disease who underwent both optical coherence tomography and intravascular ultrasound imaging, and who provided blood specimens were included. Comprehensive biomarkers for inflammation, lipid, and coagulation were analyzed. Composite models sought biomarker patterns associated with thin-cap fibroatheroma (TCFA) and "high-risk plaques" (TCFA and large plaque burden). Two different composite models were developed for TCFA, based on the finding that high sensitivity C-reactive protein (hsCRP), plasminogen activator inhibitor-1, fibrinogen, IL-6, homocysteine and amyloid A levels were elevated, and high-density lipoprotein cholesterol (HDL) and bile acid levels were decreased in these patients. Both composite models were highly accurate for detecting patients with TCFA (area under curve [AUC]: 0.883 in model-A and 0.875 in model-B, both p < 0.001). In addition, creatinine, hsCRP, fibrinogen, tumor necrosis factor-α, IL-6, homocysteine, amyloid A, HDL, prothrombin, and bile acid were useful for detecting patients with "high-risk plaques". Two composite models were highly accurate for detection of patients with "high-risk plaques" (AUC: 0.925 in model-A and 0.947 in model-B, both p < 0.001). Biomarkers useful for detection of patients with high-risk coronary plaques defined according to intravascular imaging have been identified. These biomarkers may be useful to risk stratify patients and to develop targeted therapy.Clinical Trial Registration https://www.umin.ac.jp/ctr/ , UMIN000041692. Biomarkers and high-risk plaques hsCRP, PAI-1, fibrinogen, IL-6, homocysteine, amyloid A, HDL, and bile acid were useful for detecting patients with TCFA. hsCRP, fibrinogen, IL-6, homocysteine, amyloid A, creatinine, TNFα, HDL, prothrombin, and bile acid were useful for detecting patients with "high-risk plaques" (plaque which has both TCFA and large plaque burden). White arrowhead denotes TCFA. Red and green dashed lines denote lumen area and external elastic membrane area, respectively.

Impact of directional coronary atherectomy followed by drug-coated balloon strategy to avoid the complex stenting for bifurcation lesions.

Although the simple single stenting rather than complex double stenting is recommended on percutaneous coronary intervention (PCI) for bifurcation lesions, double stenting cannot always be avoided. We investigated the impact of directional coronary atherectomy (DCA), followed by drug-coated balloon (DCB) treatment to reduce the number of stents and avoid complex stenting in PCI for bifurcation lesions and short-term patency. DCA treatment without stents was attempted for 27 bifurcation lesions in 25 patients, of those, 26 bifurcation lesions in 24 patients were successfully treated and 3-month follow-up angiography and optical coherence tomography (OCT) were performed. Sixteen lesions (59.3%) were related to left main trunk distal bifurcations, and 7 (25.9%) were true bifurcation lesions. Among the true bifurcation lesions, 4 lesions (57.1%) needed 1 stent, and the other 3 lesions (42.9%) needed no stents. Among the non-true bifurcation lesions, 1 lesion (5.0%) needed bailout stent and other lesions (95.0%) needed no stents. According to DCA followed by DCB treatment, the angiographic mean diameter stenosis improved from 65.5 ± 15.0% to 7.8 ± 9.8%, and the mean plaque area in intravascular ultrasound improved from 80.4 ± 10.5% to 39.0 ± 11.5%, respectively. Angiographic and OCT late lumen loss values were 0.2 ± 0.6 mm and 1.4 ± 1.9 mm, respectively. No patient had in-hospital major adverse cardiac events (MACE) and 3-month MACE. In conclusion, compared with standard provisional side branch stenting strategy, DCA followed by DCB treatment might reduce the number of stents, avoid complex stenting for major bifurcation lesions and provide good short-term outcomes.

De Novo Mutations Activating Germline TP53 in an Inherited Bone-Marrow-Failure Syndrome.

Inherited bone-marrow-failure syndromes (IBMFSs) include heterogeneous genetic disorders characterized by bone-marrow failure, congenital anomalies, and an increased risk of malignancy. Many lines of evidence have suggested that p53 activation might be central to the pathogenesis of IBMFSs, including Diamond-Blackfan anemia (DBA) and dyskeratosis congenita (DC). However, the exact role of p53 activation in each clinical feature remains unknown. Here, we report unique de novo TP53 germline variants found in two individuals with an IBMFS accompanied by hypogammaglobulinemia, growth retardation, and microcephaly mimicking DBA and DC. TP53 is a tumor-suppressor gene most frequently mutated in human cancers, and occasional germline variants occur in Li-Fraumeni cancer-predisposition syndrome. Most of these mutations affect the core DNA-binding domain, leading to compromised transcriptional activities. In contrast, the variants found in the two individuals studied here caused the same truncation of the protein, resulting in the loss of 32 residues from the C-terminal domain (CTD). Unexpectedly, the p53 mutant had augmented transcriptional activities, an observation not previously described in humans. When we expressed this mutant in zebrafish and human-induced pluripotent stem cells, we observed impaired erythrocyte production. These findings together with close similarities to published knock-in mouse models of TP53 lacking the CTD demonstrate that the CTD-truncation mutations of TP53 cause IBMFS, providing important insights into the previously postulated connection between p53 and IBMFSs.

Association of Multiple Gene Polymorphisms Including Homozygous NUDT15 R139C With Thiopurine Intolerance During the Treatment of Acute Lymphoblastic Leukemia.

Although thiopurine is a crucial drug for treating acute lymphoblastic leukemia, individual variations in intolerance are observed due to gene polymorphisms. A 3-year-old boy with B-cell precursor acute lymphoblastic leukemia who was administered thiopurine developed mucositis, sepsis, and hemophagocytic lymphohistiocytosis due to prolonged hematologic toxicity, chronic disseminated candidiasis, and infective endocarditis that triggered multiple brain infarctions. The patient was found to harbor 3 gene polymorphisms associated with thiopurine intolerance including homozygous NUDT15 R139C, heterozygous ITPA C94A, and homozygous MTHFR C677T and heterozygous RFC1 G80A. Thus, the combined effect of intolerance via multiple gene polymorphisms should be considered in case of unexpected adverse reactions.

EID1 suppresses lipid accumulation by inhibiting the expression of GPDH in 3T3-L1 preadipocytes.

The imbalance between food intake and energy expenditure causes high accumulation of triglycerides in adipocytes. Obesity is related with the increased lipid accumulation in white adipose tissue, which is a major risk factor for the development of metabolic disorders, such as type 2 diabetes and cardiovascular disease. This study highlights the role of E1A-like inhibitor of differentiation 1 (EID1) in the modulation of adipogenesis through the downregulation of glycerol-3-phosphate dehydrogenase (GPDH), which is a key enzyme in the synthesis of triglycerides and is considered to be a marker of adipogenesis. By analyzing DNA microarray data, we found that when EID1 is overexpressed in preadipocytes (3T3-L1 cells) during adipocyte differentiation, EID1 inhibits lipid accumulation through the downregulation of GPDH. In contrast, EID1 is not involved in the regulation of intracellular glucose via the translocation of glucose transporter. A confocal image analysis showed that EID1 is located in the nucleus of preadipocytes in the form of speckles, which could be involved as a regulator of the transcriptional process. We further confirmed that EID1 is able to bind to the promoter sequence of GPDH in the nucleus. These findings provide a molecular explanation for the inhibitory effect of EID1 on lipid accumulation in adipocytes.

Clinical, cytogenetic, and molecular analyses of 17 neonates with transient abnormal myelopoiesis and nonconstitutional trisomy 21.

BACKGROUND: Transient abnormal myelopoiesis (TAM) is a unique myeloproliferative disorder that occurs in neonates with constitutional trisomy 21/Down syndrome (DS). Although TAM also develops in neonates without constitutional trisomy 21, the clinical, cytogenetic, and molecular characteristics of those patients are not fully understood. PROCEDURE: We retrospectively evaluated the clinical and cytogenetic findings and GATA1 mutation status of 17 neonates with TAM and nonconstitutional trisomy 21 tested for GATA1 mutations at our institute, and compared the findings with those of 64 neonates with TAM and constitutional trisomy 21/DS. RESULTS: DS clinical features were observed in five of the 17 (29%) patients. In all patients, both trisomy 21 and GATA1 mutations were detected in diagnostic samples. Over a median follow-up of 33 (range, 0-139) months, early death (< 6 months of age) occurred in four patients (24%). Overall and event-free survivals were not significantly different between the patients with TAM and nonconstitutional trisomy 21 and those with TAM and constitutional trisomy 21/DS (five-year overall survival: 76% ± 10% vs 53% ± 13%, P = 0.40; five-year event-free survival: 55% ± 13% vs 48% ± 12%, P = 0.90). The five-year cumulative incidence of progression to myeloid leukemia of DS was also similar between the groups (21% vs 24%, P = 0.80). CONCLUSIONS: Patients with TAM and nonconstitutional trisomy 21 exhibited similar biology and outcomes to those with TAM and constitutional trisomy 21/DS. The possibility of TAM should be considered even in phenotypically normal neonates with TAM symptoms, for appropriate management.

A Rapid Cytologic Double Staining of Epstein-Barr Virus-encoded Small RNA and Cell Surface Markers for Diagnosis of Epstein-Barr Virus-associated Hemophagocytic Lymphohistiocytosis.

A 3-year-old boy was clinically diagnosed with Epstein-Barr virus (EBV)-associated hemophagocytic lymphohistiocytosis. We identified EBV-infected CD8-positive T-lymphocytes by cytologic double staining of the peripheral blood for EBV-encoded small RNA and cell surface markers. The patient was subsequently administered immunosuppressive therapy with a reduced dose of etoposide because of previous organ damage. EBV clearance was confirmed by serial quantification of cell-fractionated EBV-DNA, whereas EBV-DNA persisted in the plasma for 18 weeks. Immunochemotherapy with low-dose etoposide combined with serial viral load monitoring is a potential therapeutic option for severe EBV-hemophagocytic lymphohistiocytosis cases with organ damage.

Effects of 12-month exercise intervention on physical and cognitive functions of nursing home residents requiring long-term care: a non-randomised pilot study.

AIMS: We performed a 12-month exercise intervention for 'nursing home for the elderly' residents requiring long-term care. We evaluated changes in their muscular strength, muscle mass, and cognitive function. METHODS: Thirty-seven nursing home residents (Mini-Mental State Examination (MMSE): 14.7 ± 7.0, Barthel Index: 44.2 ± 18.9) were enrolled. We divided the participants into the exercise intervention group (n = 19) and non-intervention group (n = 18) ensuring no significant difference in the participants' characteristics at baseline. For the exercise intervention group, exercise was performed for about 40 min twice a week for 12 months. Skeletal Mass Index and grip force were determined to evaluate muscle mass and muscle strength, respectively. MMSE, Trail Making Test (TMT) part A, and Geriatric Depression Scale 15 (GDS15) were used for cognitive function evaluation, with their changes investigated. RESULTS: After 12 months, the MMSE scores were significantly improved in the exercise intervention group compared with the non-intervention group (change from baseline to 12 months: Non-intervention: -1.0 ± 2.8, Intervention: 1.2 ± 3.0; P = 0.04). Moreover, the grip force of the dominant arm was significantly improved in the exercise intervention group compared with the non-intervention group (change from baseline to 12 months: Non-intervention: -1.3 ± 2.8 kg, Intervention: 1.4 ± 4.6 kg; P = 0.007). The prevalence of sarcopenia was significantly increased after 12 months compared with baseline in the non-intervention group (Non-intervention: 61.1% → 75.0%, Intervention: 77.8% → 71.4%; P < 0.02). There were no significant changes in GDS15, Barthel Index and TMT after 12 months in intervention and non-intervention groups. CONCLUSION: Exercise intervention may be effectively used for improving the physical and cognitive functions of nursing home residents requiring long-term care.

Two siblings with familial neuroblastoma with distinct clinical phenotypes harboring an ALK germline mutation.

The authors report two siblings with familial neuroblastoma with a germline R1275Q mutation of the tyrosine kinase domain of ALK. Whole exome sequencing and copy number variation assay were performed to investigate genetic alterations in the two cases. No common somatic mutations or gene polymorphisms related to the tumorigenesis of neuroblastoma were detected. A distinct pattern involving both segmental chromosomal alteration and MYCN amplification was detected. The diversity of biological behavior of familial neuroblastoma harboring a germline ALK mutation may depend on conventional prognostic factors, such as segmental chromosomal alterations and MYCN amplification, rather than additional acquired mutations.