Yin Yang 1 regulates cohesin complex protein SMC3 in mouse hematopoietic stem cells.

ABSTRACT: Yin Yang 1 (YY1) and structural maintenance of chromosomes 3 (SMC3) are 2 critical chromatin structural factors that mediate long-distance enhancer-promoter interactions and promote developmentally regulated changes in chromatin architecture in hematopoietic stem/progenitor cells (HSPCs). Although YY1 has critical functions in promoting hematopoietic stem cell (HSC) self-renewal and maintaining HSC quiescence, SMC3 is required for proper myeloid lineage differentiation. However, many questions remain unanswered regarding how YY1 and SMC3 interact with each other and affect hematopoiesis. We found that YY1 physically interacts with SMC3 and cooccupies with SMC3 at a large cohort of promoters genome wide, and YY1 deficiency deregulates the genetic network governing cell metabolism. YY1 occupies the Smc3 promoter and represses SMC3 expression in HSPCs. Although deletion of 1 Smc3 allele partially restores HSC numbers and quiescence in YY1 knockout mice, Yy1-/-Smc3+/- HSCs fail to reconstitute blood after bone marrow transplant. YY1 regulates HSC metabolic pathways and maintains proper intracellular reactive oxygen species levels in HSCs, and this regulation is independent of the YY1-SMC3 axis. Our results establish a distinct YY1-SMC3 axis and its impact on HSC quiescence and metabolism.

Impact of macrophage differentiation on hematopoietic function enhancement by Shenzhu ErKang Syrup.

Shenzhu Erkang Syrup (SZEK) is a traditional Chinese medicine that improves spleen and stomach function, tonifying the Qi and activating the blood; however, its therapeutic effects in hematopoietic dysfunction and their underlying mechanism remain unexplored. In this study, mice were given cyclophosphamide (100 mg/kg) by intraperitoneal injections for three days to produce hematopoietic dysfunction model. We investigated the hematopoietic effect and mechanism of SZEK in mice with hematopoietic dysfunction via histopathological examination, flow cytometry, enzyme-linked immunosorbent assay, and Western blotting combined with intestinal flora and serum metabolomics analysis. In mice with hematopoietic dysfunction, SZEK (gavage, 0.3 mL/25 g) alleviated pathological damage to the bone marrow and spleen; increased the number of naïve cells (Lin-), hematopoietic stem cells (Lin-Sca-1+c-Kit+), long-term self-renewing hematopoietic stem cells (Lin-Sca-1+c-Kit+CD48-CD150+), B lymphocytes (CD45+CD19+), and macrophages (CD11b+F4/80+) in the bone marrow; and reduced inflammation. Preliminary intestinal flora and serum metabolome analyses indicated that the pro-hematopoietic mechanism of SZEK was associated with macrophage differentiation. Further validation revealed that SZEK promoted hematopoiesis by decreasing the number of M2 macrophages and inhibiting the secretion of negative hematopoietic regulatory factors in mice with hematopoietic dysfunction.

A Bloody Feast-Nutritional Regulation of Hematopoiesis.

Hematopoietic stem cells provide us with a lifelong supply of blood cells. Hence, their proper function is absolutely essential for life, and their dysfunction can lead to infectious and malignant diseases. These cells have specific metabolic requirements to enable their lifelong function and blood-producing capacity. With the words of the Roman poet Juvenal "a healthy mind in a healthy body" in mind, it is intriguing to understand the connection between our daily diet and the quality of our blood, with the hope that through specific dietary adjustments we can improve our hematopoietic stem cell function and prevent disease. Nowadays, dietary supplements are an expanding market filled with potential and promises for better health. However, the link between many of those supplements and human physiology is obscure. Several groups have begun to shed light on this by investigating the metabolic regulation of hematopoiesis by specific nutrients. Beyond the link to dietary supplementation, these studies have also significantly improved our understanding of basic hematopoietic stem cell biology. Herein we summarize recent knowledge on the effect of specific vitamins and amino acids, which might be considered as dietary supplements, on normal hematopoiesis and hematopoietic stem cell function. We propose that improving our understanding of the link between nutrition in general and blood physiology can ultimately lead to the optimization of health-care policies, protocols, and standards of care.

The Zinc Transporter SLC39A10 Plays an Essential Role in Embryonic Hematopoiesis.

The role of zinc in hematopoiesis is currently unclear. Here, SLC39A10 (ZIP10) is identified as a key zinc transporter in hematopoiesis. The results show that in zebrafish, Slc39a10 is a key regulator of the response to zinc deficiency. Surprisingly, both slc39a10 mutant zebrafish and hematopoietic Slc39a10-deficient mice develop a more severe form of impaired hematopoiesis than animals lacking transferrin receptor 1, a well-characterized iron gatekeeper, indicating that zinc plays a larger role than iron in hematopoiesis, at least in early hematopoietic stem cells (HSCs). Furthermore, it is shown that loss of Slc39a10 causes zinc deficiency in fetal HSCs, which in turn leads to DNA damage, apoptosis, and G1 cell cycle arrest. Notably, zinc supplementation largely restores colony formation in HSCs derived from hematopoietic Slc39a10-deficient mice. In addition, inhibiting necroptosis partially restores hematopoiesis in mouse HSCs, providing mechanistic insights into the requirement for zinc in mediating hematopoiesis. Together, these findings indicate that SLC39A10 safeguards hematopoiesis by protecting against zinc deficiency-induced necroptosis, thus providing compelling evidence that SLC39A10 and zinc homeostasis promote the development of fetal HSCs. Moreover, these results suggest that SLC39A10 may serve as a novel therapeutic target for treating anemia and zinc deficiency-related disorders.

[Effect of wheat-grain moxibustion on Wnt/ß-catenin signaling pathway in bone marrow cell in mice with bone marrow inhibition].

OBJECTIVE: To observe the effect of wheat-grain moxibustion at "Dazhui" (GV 14), "Zusanli" (ST 36) and "Sanyinjiao" (SP 6) on Wnt/ß-catenin signaling pathway in bone marrow cell in mice with bone marrow inhibition, and to explore the possible mechanism of wheat-grain moxibustion in treating bone marrow inhibition. METHODS: Forty-five SPF male CD1(ICR) mice were randomly divided into a blank group, a model group and a wheat-grain moxibustion group, 15 mice in each group. The bone marrow inhibition model was established by intraperitoneal injection of 80 mg/kg of cyclophosphamide (CTX). The mice in the wheat-grain moxibustion group were treated with wheat-grain moxibustion at "Dazhui" (GV 14), "Zusanli" (ST 36) and "Sanyinjiao" (SP 6), 3 moxa cones per acupoint, 30 s per moxa cone, once a day, for 7 consecutive days. The white blood cell count (WBC) was measured before modeling, before intervention and 3, 5 d and 7 d into intervention. After intervention, the general situation of mice was observed; the number of nucleated cells in bone marrow was detected; the serum levels of interleukin-3 (IL-3), interleukin-6 (IL-6) and granulocyte macrophage colony stimulating factor (GM-CSF) were measured by ELISA; the protein and mRNA expression of ß-catenin, cyclinD1 and C-Myc in bone marrow cells was measured by Western blot and real-time PCR method. RESULTS: Compared with the blank group, the mice in the model group showed sluggish reaction, unstable gait, decreased body weight, and the WBC, number of nucleated cells in bone marrow as well as serum levels of IL-3, IL-6, GM-CSF were decreased (P<0.01), and the protein and mRNA expression of ß-catenin, cyclinD1 and C-Myc was decreased (P<0.01). Compared with the model group, the mice in the wheat-grain moxibustion group showed better general condition, and WBC, the number of nucleated cells in bone marrow as well as serum levels of IL-3, IL-6, GM-CSF were increased (P<0.01, P<0.05), and the protein and mRNA expression of ß-catenin, cyclinD1 and C-Myc was increased (P<0.05). CONCLUSION: Wheat-grain moxibustion shows therapeutic effect on bone marrow inhibition, and its mechanism may be related to activating Wnt/ß-catenin signaling pathway in bone marrow cells, improving bone medullary hematopoiesis microenvironment and promoting bone marrow cell proliferation.

Selenium Improves Bone Microenvironment-Related Hematopoiesis and Immunity in T-2 Toxin-Exposed Mice.

The T-2 toxin is one of the most frequent contaminants in the environment and agricultural production globally. It exerts a wide range of toxic effects. Selenium (Se), as an antioxidant, has the potential to be widely used to antagonize mycotoxin toxicity. To investigate the protective effects of Se on bone microenvironment (BM)-related hematopoiesis and immunity after T-2 toxin exposure, 36 male mice were treated with the T-2 toxin (1 mg/kg) and/or Se (0.2 mg/kg) by intragastric administration for 28 days. The results showed that Se alleviated T-2 toxin-induced cytopenia and splenic extramedullary hematopoiesis. Se also significantly relieved T-2 toxin-induced immunosuppression, as assessed by immune factors and lymphocytes. Furthermore, Se also attenuated oxidative stress and apoptosis and improved the BM in T-2 toxin-exposed mice. Therefore, Se improves BM-related hematopoiesis and immunity after T-2 toxin exposure. This study provides references for identifying the toxic mechanism and screening potential therapeutic drugs of the T-2 toxin.

Effect of wheat-grain moxibustion on Wnt/β-catenin signaling pathway in bone marrow cell in mice with bone marrow inhibition / 中国针灸

OBJECTIVE@#To observe the effect of wheat-grain moxibustion at "Dazhui" (GV 14), "Zusanli" (ST 36) and "Sanyinjiao" (SP 6) on Wnt/β-catenin signaling pathway in bone marrow cell in mice with bone marrow inhibition, and to explore the possible mechanism of wheat-grain moxibustion in treating bone marrow inhibition.@*METHODS@#Forty-five SPF male CD1(ICR) mice were randomly divided into a blank group, a model group and a wheat-grain moxibustion group, 15 mice in each group. The bone marrow inhibition model was established by intraperitoneal injection of 80 mg/kg of cyclophosphamide (CTX). The mice in the wheat-grain moxibustion group were treated with wheat-grain moxibustion at "Dazhui" (GV 14), "Zusanli" (ST 36) and "Sanyinjiao" (SP 6), 3 moxa cones per acupoint, 30 s per moxa cone, once a day, for 7 consecutive days. The white blood cell count (WBC) was measured before modeling, before intervention and 3, 5 d and 7 d into intervention. After intervention, the general situation of mice was observed; the number of nucleated cells in bone marrow was detected; the serum levels of interleukin-3 (IL-3), interleukin-6 (IL-6) and granulocyte macrophage colony stimulating factor (GM-CSF) were measured by ELISA; the protein and mRNA expression of β-catenin, cyclinD1 and C-Myc in bone marrow cells was measured by Western blot and real-time PCR method.@*RESULTS@#Compared with the blank group, the mice in the model group showed sluggish reaction, unstable gait, decreased body weight, and the WBC, number of nucleated cells in bone marrow as well as serum levels of IL-3, IL-6, GM-CSF were decreased (P<0.01), and the protein and mRNA expression of β-catenin, cyclinD1 and C-Myc was decreased (P<0.01). Compared with the model group, the mice in the wheat-grain moxibustion group showed better general condition, and WBC, the number of nucleated cells in bone marrow as well as serum levels of IL-3, IL-6, GM-CSF were increased (P<0.01, P<0.05), and the protein and mRNA expression of β-catenin, cyclinD1 and C-Myc was increased (P<0.05).@*CONCLUSION@#Wheat-grain moxibustion shows therapeutic effect on bone marrow inhibition, and its mechanism may be related to activating Wnt/β-catenin signaling pathway in bone marrow cells, improving bone medullary hematopoiesis microenvironment and promoting bone marrow cell proliferation.

Deciphering the Effects of 2D Black Phosphorus on Disrupted Hematopoiesis and Pulmonary Immune Homeostasis Using a Developed Flow Cytometry Method.

As an emerging two-dimensional nanomaterial with promising prospects, mono- or few-layer black phosphorus (BP) is potentially toxic to humans. We investigated the effects of two types of BPs on adult male mice through intratracheal instillation. Using the flow cytometry method, the generation, migration, and recruitment of immune cells in different organs have been characterized on days 1, 7, 14, and 21 post-exposure. Compared with small BP (S-BP, lateral size at ∼188 nm), large BP (L-BP, lateral size at ∼326 nm) induced a stronger stress lymphopoiesis and B cell infiltration into the alveolar sac. More importantly, L-BP dramatically increased peripheral neutrophil (NE) counts up to 1.9-fold on day 21 post-exposure. Decreased expression of the CXCR4 on NEs, an important regulator of NE retention in the bone marrow, explained the increased NE release into the circulation induced by L-BP. Therefore, BP triggers systemic inflammation via the disruption of both the generation and migration of inflammatory immune cells.

Xist exerts gene-specific silencing during XCI maintenance and impacts lineage-specific cell differentiation and proliferation during hematopoiesis.

X chromosome inactivation (XCI) is a dosage compensation phenomenon that occurs in females. Initiation of XCI depends on Xist RNA, which triggers silencing of one of the two X chromosomes, except for XCI escape genes that continue to be biallelically expressed. In the soma XCI is stably maintained with continuous Xist expression. How Xist impacts XCI maintenance remains an open question. Here we conditionally delete Xist in hematopoietic system of mice and report differentiation and cell cycle defects in female hematopoietic stem and progenitor cells (HSPCs). By utilizing female HSPCs and mouse embryonic fibroblasts, we find that X-linked genes show variable tolerance to Xist loss. Specifically, XCI escape genes exhibit preferential transcriptional upregulation, which associates with low H3K27me3 occupancy and high chromatin accessibility that accommodates preexisting binding of transcription factors such as Yin Yang 1 (YY1) at the basal state. We conclude that Xist is necessary for gene-specific silencing during XCI maintenance and impacts lineage-specific cell differentiation and proliferation during hematopoiesis.

Effects of Soy-Whey Protein Nutritional Supplementation on Hematopoiesis and Immune Reconstitution in an Allogeneic Transplanted Mice.

Profound malnutrition and immunodeficiency are serious negative effects of radiotherapy and bone marrow transplantation for hematologic malignancy patients. This study aimed to evaluate the effects of nutritional supplementation with a soy-whey protein mixture on hematopoietic and immune reconstitution in an allogeneic transplant mouse model. Male BALB/c (H-2Kd) mice, 6-8 weeks-old, were divided randomly into five groups and then provided with different protein nutrition support. After 28 days, blood samples, bone marrow, spleen, and thymus were harvested to measure the effects. The results showed that soy-whey blended protein supplements promoted hematopoietic stem cell engraftment, body weight recovery, and the recovery of white blood cells, lymphocytes, and neutrophils; triggered the expansion of hematopoietic stem cells and progenitor cell pools by increasing the numbers of the c-kit+ progenitor, Lin-Sca1+c-kit+, short-term hematopoietic stem cells, and multipotent progenitors; enhanced thymus re-establishment and splenic subset recovery in both organ index and absolute number; improved overall nutritional status by increasing total serum protein, albumin, and globulin; protected the liver from radiation-induced injury, and increased antioxidant capacity as indicated by lower concentrations of alanine aminotransferase, aspartate aminotransferase, malondialdehyde, and 4-hydroxynonenal. This study indicated that soy-whey blended protein as important nutrients, from both plant and animal sources, had a greater positive effect on patients with hematological malignancies to accelerate hematopoiesis and immune reconstitution after bone marrow transplantation.

Mechanisms of Danggui Buxue Tang on Hematopoiesis via Multiple Targets and Multiple Components: Metabonomics Combined with Database Mining Technology.

This study aimed to explore the mechanism of action of Danggui Buxue Tang (DBT) with its multiple components and targets in the synergistic regulation of hematopoiesis. Mouse models of hematopoiesis were established using antibiotics. Metabolomics was used to detect body metabolites and enriched pathways. The active ingredients, targets, and pathways of DBT were analyzed using system pharmacology. The results of metabolomics and system pharmacology were integrated to identify the key pathways and targets. A total of 515 metabolites were identified using metabolomics. After the action of antibiotics, 49 metabolites were markedly changed: 23 were increased, 26 were decreased, and 11 were significantly reversed after DBT administration. Pathway enrichment analysis showed that these 11 metabolites were related to bile secretion, cofactor biosynthesis, and fatty acid biosynthesis. The results of the pharmacological analysis showed that 616 targets were related to DBT-induced anemia, which were mainly enriched in biological processes, such as bile secretion, biosynthesis of cofactors, and cholesterol metabolism. Combined with the results of metabolomics and system pharmacology, we found that bile acid metabolism and biotin synthesis were the key pathways for DBT. Forty-two targets of DBT were related to these two metabolic pathways. PPI analysis revealed that the top 10 targets were CYP3A4, ABCG2, and UGT1A8. Twenty-one components interacted with these 10 targets. In one case, a target corresponds to multiple components, and a component corresponds to multiple targets. DBT acts on multiple targets of ABCG2, UGT1A8, and CYP3A4 through multiple components, affecting the biosynthesis of cofactors and bile secretion pathways to regulate hematopoiesis.

The histone lysine acetyltransferase HBO1 (KAT7) regulates hematopoietic stem cell quiescence and self-renewal.

The histone acetyltransferase HBO1 (MYST2, KAT7) is indispensable for postgastrulation development, histone H3 lysine 14 acetylation (H3K14Ac), and the expression of embryonic patterning genes. In this study, we report the role of HBO1 in regulating hematopoietic stem cell function in adult hematopoiesis. We used 2 complementary cre-recombinase transgenes to conditionally delete Hbo1 (Mx1-Cre and Rosa26-CreERT2). Hbo1-null mice became moribund due to hematopoietic failure with pancytopenia in the blood and bone marrow 2 to 6 weeks after Hbo1 deletion. Hbo1-deleted bone marrow cells failed to repopulate hemoablated recipients in competitive transplantation experiments. Hbo1 deletion caused a rapid loss of hematopoietic progenitors. The numbers of lineage-restricted progenitors for the erythroid, myeloid, B-, and T-cell lineages were reduced. Loss of HBO1 resulted in an abnormally high rate of recruitment of quiescent hematopoietic stem cells (HSCs) into the cell cycle. Cycling HSCs produced progenitors at the expense of self-renewal, which led to the exhaustion of the HSC pool. Mechanistically, genes important for HSC functions were downregulated in HSC-enriched cell populations after Hbo1 deletion, including genes essential for HSC quiescence and self-renewal, such as Mpl, Tek(Tie-2), Gfi1b, Egr1, Tal1(Scl), Gata2, Erg, Pbx1, Meis1, and Hox9, as well as genes important for multipotent progenitor cells and lineage-specific progenitor cells, such as Gata1. HBO1 was required for H3K14Ac through the genome and particularly at gene loci required for HSC quiescence and self-renewal. Our data indicate that HBO1 promotes the expression of a transcription factor network essential for HSC maintenance and self-renewal in adult hematopoiesis.

An experimental study on the effect of preoperative autologous blood donation on bone marrow hematopoiesis and hematopoietic stem cells.

To evaluate the effect of autologous blood transfusion (ABT) on hematopoietic stem cells through the observation of the changes in the number and activity of bone marrow CD34+ cells after preoperative autologous blood donation (PABD). Rabbit bone marrow specimens were collected preoperatively (T2), 6 h postoperatively (T3), and 24 h postoperatively (T4). Next, the percentages of CD34+ cells, the cell cycle, and the relative expression of telomeric DNA were measured in each group of rabbits. Peripheral blood specimens were collected before PABD (T1) and at T4 to measure reticulocytes. At T3 and T4, the percentages of CD34+ cells and the expressions of telomeric DNA were significantly higher, and the percentages of cells in the G1 phase were significantly lower in each experimental group compared with those in the blank control group (group A) (P<0.05). Compared with the surgical blood collection group (group C), the CD34+ cells and the expressions of telomeric DNA were significantly higher, and the percentages of cells in the G1 phase were significantly lower in the preoperative autologous whole blood group (group D) and the preoperative autologous blood component group (group E) (P<0.05). Compared with group D, the CD34+ cells and the expressions of telomeric DNA were significantly lower, and the percentages of cells in the G1 phase were significantly higher in group E (P<0.05). At T4, the reticulocyte percentages in the surgery group (group B) and group C were significantly higher than in group E and group D, and the reticulocyte percentages in group E were higher than in group D (P<0.05). This study's findings indicated that ABT suppressed bone marrow hematopoiesis, while autologous blood component transfusion had less of an effect than that of whole blood transfusion. Therefore, PABD blood component transfusion would be superior to autologous whole blood transfusion.

Enriched clonal hematopoiesis in seniors with dietary vitamin C inadequacy.

BACKGROUND: The anti-cancer effect of vitamin C (VC) has long been speculated, but studies yielded inconsistency. Recent studies reported that supraphysiological concentration of VC have therapeutic or prevention effects for myeloid malignancies with certain mutation signatures. There was a notable proportion of DAT (i.e., DNMT3A, ASXL1, and TET2) and dozens of other genes that mutate in age-related clonal hematopoiesis (ARCH). METHODS AND RESULTS: Through analyzing the plasma VC concentration and mutations of 21 genes in 215 senior volunteers, we revealed that ARCH is significantly associated with dietary plasma VC concentrations, especially TET2 mutations and non-DAT mutations. CONCLUSION: This study firstly disclosed the significant association between VC inadequacy and ARCH in the senior population. It provides evidence that physiological VC concentration has ARCH prevention effect. It will illuminate future explorations on the oral VC supplement in maintaining sound hematopoiesis, reversal ARCH, adjuvant therapy for myeloid malignancies, and prevention of other ARCH related comorbidities.

Induced Pluripotent Stem Cells as a Tool for Modeling Hematologic Disorders and as a Potential Source for Cell-Based Therapies.

The breakthrough in human induced pluripotent stem cells (hiPSCs) has revolutionized the field of biomedical and pharmaceutical research and opened up vast opportunities for drug discovery and regenerative medicine, especially when combined with gene-editing technology. Numerous healthy and patient-derived hiPSCs for human disease modeling have been established, enabling mechanistic studies of pathogenesis, platforms for preclinical drug screening, and the development of novel therapeutic targets/approaches. Additionally, hiPSCs hold great promise for cell-based therapy, serving as an attractive cell source for generating stem/progenitor cells or functional differentiated cells for degenerative diseases, due to their unlimited proliferative capacity, pluripotency, and ethical acceptability. In this review, we provide an overview of hiPSCs and their utility in the study of hematologic disorders through hematopoietic differentiation. We highlight recent hereditary and acquired genetic hematologic disease modeling with patient-specific iPSCs, and discuss their applications as instrumental drug screening tools. The clinical applications of hiPSCs in cell-based therapy, including the next-generation cancer immunotherapy, are provided. Lastly, we discuss the current challenges that need to be addressed to fulfill the validity of hiPSC-based disease modeling and future perspectives of hiPSCs in the field of hematology.

PAC1 Receptor Mediates Electroacupuncture-Induced Neuro and Immune Protection During Cisplatin Chemotherapy.

Platinum-based chemotherapy is an effective treatment used in multiple tumor treatments, but produces severe side effects including neurotoxicity, anemia, and immunosuppression, which limits its anti-tumor efficacy and increases the risk of infections. Electroacupuncture (EA) is often used to ameliorate these side effects, but its mechanism is unknown. Here, we report that EA on ST36 and SP6 prevents cisplatin-induced neurotoxicity and immunosuppression. EA induces neuroprotection, prevents pain-related neurotoxicity, preserves bone marrow (BM) hematopoiesis, and peripheral levels of leukocytes. EA activates sympathetic BM terminals to release pituitary adenylate cyclase activating polypeptide (PACAP). PACAP-receptor PAC1-antagonists abrogate the effects of EA, whereas PAC1-agonists mimic EA, prevent neurotoxicity, immunosuppression, and preserve BM hematopoiesis during cisplatin chemotherapy. Our results indicate that PAC1-agonists may provide therapeutic advantages during chemotherapy to treat patients with advanced neurotoxicity or neuropathies limiting EA efficacy.

Vitamin D Deficiency, Osteoporosis and Effect on Autoimmune Diseases and Hematopoiesis: A Review.

Vitamin D (VD) is essential for bone homeostasis, but it is also involved in pleiotropic effects on various organs and tissues. In adults, VD deficiency can cause or exacerbate osteoporosis and induce osteomalacia. However, every tissue and cell in the body has a VD receptor, including the brain, heart, stomach, pancreas, skin, gonads, and immune cells, and a deficiency may modify the function of these organs. Thus, the wide-ranging actions of VD help to explain why a reduction in VD amount has been correlated with numerous chronic diseases. In fact, VD deficiency increases the risk of osteoporosis and several other diseases and complications characterized by impaired bone metabolisms, such as autoimmune diseases, inflammatory bowel diseases, allergy, endocrinological diseases, hematological malignancies, and bone marrow transplantation. This review aims to investigate the link between VD deficiency, osteoporosis, and its concomitant diseases. Further epidemiological and mechanistic studies are necessary in order to ascertain the real role of hypovitaminosis in causing the reported diseases; however, adequate vitamin supplementation and restoration of metabolic normality could be useful for better management of these pathologies.

Tanshinone I, a new EZH2 inhibitor restricts normal and malignant hematopoiesis through upregulation of MMP9 and ABCG2.

Rationale: Tanshinone, a type of diterpenes derived from salvia miltiorrhiza, is a particularly promising herbal medicine compound for the treatment of cancers including acute myeloid leukemia (AML). However, the therapeutic function and the underlying mechanism of Tanshinone in AML are not clear, and the toxic effect of Tanshinone limits its clinical application. Methods: Our work utilizes human leukemia cell lines, zebrafish transgenics and xenograft models to study the cellular and molecular mechanisms of how Tanshinone affects normal and abnormal hematopoiesis. WISH, Sudan Black and O-Dianisidine Staining were used to determine the expression of hematopoietic genes on zebrafish embryos. RNA-seq analysis showed that differential expression genes and enrichment gene signature with Tan I treatment. The surface plasmon resonance (SPR) method was used with a BIAcore T200 (GE Healthcare) to measure the binding affinities of Tan I. In vitro methyltransferase assay was performed to verify Tan I inhibits the histone enzymatic activity of the PRC2 complex. ChIP-qPCR assay was used to determine the H3K27me3 level of EZH2 target genes. Results: We found that Tanshinone I (Tan I), one of the Tanshinones, can inhibit the proliferation of human leukemia cells in vitro and in the xenograft zebrafish model, as well as the normal and malignant definitive hematopoiesis in zebrafish. Mechanistic studies illustrate that Tan I regulates normal and malignant hematopoiesis through direct binding to EZH2, a well-known histone H3K27 methyltransferase, and inhibiting PRC2 enzymatic activity. Furthermore, we identified MMP9 and ABCG2 as two possible downstream genes of Tan I's effects on EZH2. Conclusions: Together, this study confirmed that Tan I is a novel EZH2 inhibitor and suggested MMP9 and ABCG2 as two potential therapeutic targets for myeloid malignant diseases.

Radix Astragali polysaccharide RAP directly protects hematopoietic stem cells from chemotherapy-induced myelosuppression by increasing FOS expression.

Radix Astragali polysaccharide RAP has been reported to play a crucial role in hematopoiesis without a clear mechanism. In this study, RAP's effects to enhance the recovery of cyclophosphamide (Cy)-suppressed bone marrow and blood cells is confirmed in vivo first. Confocal micrographs demonstrated the interesting direct binding of FITC-RAP to hematopoietic stem cells (HSC) in bone marrow. RAP protects both mice and human HSC in terms of cell morphology, proliferation, and apoptosis. RNA-sequencing and shRNA approaches revealed FOS to be a key regulator in RAP's protection. These evidences provide an unreported mechanism that RAP directly protects hematopoietic stem cells from chemotherapy-induced myelosuppression by increasing FOS expression.

Ush regulates hemocyte-specific gene expression, fatty acid metabolism and cell cycle progression and cooperates with dNuRD to orchestrate hematopoiesis.

The generation of lineage-specific gene expression programmes that alter proliferation capacity, metabolic profile and cell type-specific functions during differentiation from multipotent stem cells to specialised cell types is crucial for development. During differentiation gene expression programmes are dynamically modulated by a complex interplay between sequence-specific transcription factors, associated cofactors and epigenetic regulators. Here, we study U-shaped (Ush), a multi-zinc finger protein that maintains the multipotency of stem cell-like hemocyte progenitors during Drosophila hematopoiesis. Using genomewide approaches we reveal that Ush binds to promoters and enhancers and that it controls the expression of three gene classes that encode proteins relevant to stem cell-like functions and differentiation: cell cycle regulators, key metabolic enzymes and proteins conferring specific functions of differentiated hemocytes. We employ complementary biochemical approaches to characterise the molecular mechanisms of Ush-mediated gene regulation. We uncover distinct Ush isoforms one of which binds the Nucleosome Remodeling and Deacetylation (NuRD) complex using an evolutionary conserved peptide motif. Remarkably, the Ush/NuRD complex specifically contributes to the repression of lineage-specific genes but does not impact the expression of cell cycle regulators or metabolic genes. This reveals a mechanism that enables specific and concerted modulation of functionally related portions of a wider gene expression programme. Finally, we use genetic assays to demonstrate that Ush and NuRD regulate enhancer activity during hemocyte differentiation in vivo and that both cooperate to suppress the differentiation of lamellocytes, a highly specialised blood cell type. Our findings reveal that Ush coordinates proliferation, metabolism and cell type-specific activities by isoform-specific cooperation with an epigenetic regulator.