Effect of Rheb1 in the Development of Mouse Megakaryocyte-Erythroid Progenitor Cells / 中国实验血液学杂志

OBJECTIVE@#To investigate the effect of Rheb1 in the development of mouse megakaryocyte-erythroid progenitor cells and its related mechanism.@*METHODS@#Rheb1 was specifically knocked-out in the hematopoietic system of Vav1-Cre;Rheb1fl/fl mice(Rheb1Δ/Δ mice). Flow cytometry was used to detect the percentage of red blood cells in peripheral blood and erythroid cells in bone marrow in Vav1-Cre;Rheb1fl/fl mice and control mice. The CFC assay was used to detect the differentiation ability of Rheb1 KO megakaryocyte-erythroid progenitor cells and control cells. Real-time fluorescence quantification PCR was used to detect the relative expression of PU.1,GATA-1,GATA-2,CEBPα and CEBPβ of Rheb1 KO megakaryocyte-erythroid progenitor cells and control cells. Rapamycin was added to the culture medium, and it was used to detect the changes in cloning ability of megakaryocyte-erythroid progenitor cells from wild-type mice in vitro.@*RESULTS@#After Rheb1 was knocked out, the development and stress response ability of megakaryocyte-erythroid progenitor cells in mice were weaken and the differentiation ability of megakaryocyte-erythroid progenitor cells in vitro was weaken. Moreover, the expression of GATA-1 of megakaryocyte-erythroid progenitor cells was decreased. Further, rapamycin could inhibit the differentiative capacity of megakaryocyte-erythroid progenitor cells in vitro.@*CONCLUSION@#Rheb1 can regulate the development of megakaryocyte-erythroid progenitor cells probably through the mTOR signaling pathway in mice.

Proportion and role of CD45+ erythroid progenitor cells in patients with tongue cancer metastasis / 中华口腔医学杂志

Objective@#To investigate the proportion and role of CD45+ erythroid progenitor cells (EPC) in patients with tongue cancer metastasis.@*Methods@#The initial treatment of tongue cancer patients (n=40) from January 2017 to June 2018 in He'nan Provincial People′s Hospital was included in this study. According to the presence or absence of lymph node metastasis, they were divided into tumor group (no lymph node metastasis was found in imaging and pathology) and metastasis group (both imaging and pathology confirmed lymph node metastasis). The expression of Ki-67 was detected by immunohistochemistry and the proportion of CD45+CD71+TER119+EPC was detected by flow cytometry. EPC was sorted by flow cytometry, interleukin-10 (IL-10) and transforming growth factor-β (TGF-β) were detected by enzyme-linked immunosorbent assay (ELISA), and reactive oxygen species (ROS) was detected by flow cytometry. Transwell was used for tumor invasion test; methyl thiazolyltetrazolium (MTT) assay was used to detect proliferation level.@*Results@#There were 20 cases in the tumor group and metastasis group. There was no significant difference between the two groups in terms of age, sex, time of onset and size of tumors. Flow cytometry showed that the ratio of CD45+EPC in peripheral blood of tumor group and metastasis group was (1.2±0.2)% and (3.1±0.2)% (t=7.823, P<0.001). Correlation analysis showed that the ratio of CD45+EPC was positively correlated with the proliferation index of Ki-67 cells (r=0.592, P=0.006). The results of flow cytometry showed that the mean fluorescence intensity (MFI) of ROS in EPC was 102.1±22.9 in tumor group and 530.0±67.2 in metastasis group (t=6.025,P<0.001). The results of ELISA showed that the mass concentrations of IL-10 and TGF-β in EPC supernatant of tumor group were (10.8±1.6) and (3.2±0.8) μg/L, respectively. The mass concentrations of IL-10 and TGF-beta in EPC supernatant of metastasis group were (26.9±3.7) and (6.4±0.9) μg/L, respectively (t=3.956, P=0.003; t=2.595, P=0.027). Transwell results showed that the proportion of invasive cells in the CD45+EPC group [(40.3±4.4)%] was higher than that in the control group [(17.5±2.2)%] (t=4.607, P=0.001). MTT proliferation experiment showed that the proliferation rate of the CD45+EPC group [(52.0±3.3)%] was higher than that of the control group [(30.5±1.9)%] (t=5.656, P<0.001).@*Conclusions@#The proportion of CD45+EPC in patients with tongue cancer metastasis is significantly increased. CD45+EPC can promote the proliferation and metastasis of tongue cancer by secreting immunosuppressive molecules and ROS.

Effects of erythropoietin on peripheral blood endothelial progenitor cells from rats with chronic kidney disease / 中华肾脏病杂志

Objective To investigate the effects of erythropoietin (EPO) on the number and function of peripheral blood endothelial progenitor cells (EPCs) from rats with chronic renal failure (CRF). Methods The model of chronic renal failure was established by a two-stage 5/6nephrectomy procedure in rats. Experimental rats were randomly divided into four groups (n =7,respectively): sham operation group, CRF group, CRF rats treated with 30 U/kg EPO (low-dosage group) and with 50 U/kg EPO (high-dosage group). CRF rats were given EPO by hypodermic injection for 6 weeks, then EPCs were isolated by density gradient centrifugation from peripheral blood mononuclear cells. The ability of cell proliferation, adhesion and vasculogenesis in vitro was further observed. Results Compared to sham operation group, the ability of cell proliferation,adhesion and vasculogenesis in vitro in CRF rats was remarkably decreased (P＜0.05, respectively).Such ability was promoted significantly in dose-dependent manner by EPO treatment (P＜0.05,respectively). Conclusion EPO can improve the number and ability of endothelial progenitor cells from rats with chronic renal failure.

Human erythroid progenitors from adult bone marrow and cord blood in optimized liquid culture systems respectively maintained adult and neonatal characteristics of globin gene expression

In vitro suspension culture procedures for erythroid progenitor cells make it possible for us to obtain large cultures of erythrocyte populations for the investigation of globin gene switching. In this study we aimed to establish optimized culture systems for neonatal and adult erythroblasts and to explore the globin expression patterns in these culture systems. To culture CD34+ cells purified from human umbilical cord blood (CB) and adult bone marrow (BM), we respectively replaced the fetal bovine serum (FBS) with human cord serum and human adult serum. These CD34+ cells were then induced to erythroid differentiation. All the globin mRNA (including alfa-, xi-, vita-, gama-and epsilón-globin), the hemoglobin (Hb)-producing erythroid cells and the cellular distribution of fetal hemoglobin (Hb F) were identified during the culture process. The results showed that the globin expression pattern during erythroid differentiation in our culture systems closely recapitulated neonatal and adult patterns of globin expression in vivo, suggesting that our specially optimized culture systems not only overcame the higher Hb F levels in the BM-derived CD34+ culture in FBS-containing medium but also eliminated the disadvantages of low cell proliferation rate and low globin mRNA levels in serum-free medium.

Capsaicin promotes the development of burst-forming nits-erythroid (BFU-E) from mouse bone marrow cells

Capsaicin, the pungent component of chilli peppers, is known to induce mediators of hematopoiesis. We investigated the effect of capsaicin on hematopoiesis in mouse progenitor cells. Treatment of mouse bone marrow cells with capsaicin induced the formation of colony of burst-forming units-erythroid (BFU-E). We also found that the number of erythropoietin receptor (EpoR)-positive cells was increased by capsaicin. To clarify the effect of capsaicin on erythroid lineage, BFU-E colonies were separated from non-BFU-E colonies by colony-picking after in vitro culture of mouse bone marrow cells. Quantitative RT-PCR analysis revealed that capsaicin stimulated the expression of the erythroid-specific genes encoding EpoR, glycophorin A (GPA), beta-globin (Hbb-b1), GATA-1, PU.1, nuclear factor erythroid-derived 2 (NF-E2), and Kruppel-like factor 1 (KLF1) in the BFU-E colonies. Furthermore, capsaicin could effectively stimulate the transfected GATA-1 promoter in K562 cells. GATA-1 is known as an essential transcription factor for the development of erythroid cells. Our results show that development of the erythroid lineage from bone marrow cells can be induced by treatment with capsaicin, and that GATA-1 seems to play a role in this induced erythroid maturation.

Direct and Indirect Effects of Androgens on Survival of Hematopoietic Progenitor Cells In Vitro

Androgens remain a common treatment for certain type of anemia, based upon its myelostimulating effects; however, it has not been established whether androgens affect apoptosis of hematopoietic progenitor cells (HPCs). We investigated the effects of the androgens, such as testosterone, 5beta-dihydrotestosterone (5-DHT), and oxymetholone, on apoptosis of normal hematopoietic progenitor cells in vitro. Androgens did not rescue normal bone marrow (BM) CD34+ cells and colony-forming cells (CFCs), other than mature erythroid CFCs, from apoptosis induced by serum- and growth factor deprivation. Oxymetholone did not affect growth factor-mediated survival of normal CD34+ cells or its inhibition by interferon-gamma (IFN-gamma). In a standard methylcellulose clonogenic assay, low concentrations of oxymetholone and 5-DHT stimulated the clonal growth of colony-forming unit (CFU)-erythroid, but did not affect growth of CFU-granulocyte/macrophage or burst-forming unit-erythroid. Oxymetholone and 5-DHT stimulated the production of stem cell factor in normal bone marrow stromal cells (BMSCs) via transcriptional regulation. In agreement with this, oxymetholone-treated BMSCs better supported the survival of HPCs. These data indicate that survival-enhancing or growth-stimulatory effects of androgens on hematopoietic progenitor cells are minimal and mostly restricted to mature erythroid progenitors, and its myelostimulating effects could be attributed, at least in part, to the stimulation of production of hematopoietic growth factors in BMSCs.

Comparison of CD34+ subsets and clonogenicity in human bone marrow, granulocyte colony-stimulating factor-mobilized peripheral blood, and cord blood

To compare the clonogenicity and distribution of CD34+ subsets in bone marrow (BM), granulocyte colony-stimulating factor (G-CSF) mobilized peripheral blood (PB) and cord blood (CB), we analyzed in vitro colony formation and CD34+ cells co-expressing differentiation molecules (CD38, HLA-DR), myeloid associated molecules (CD13, CD33), a T-cell associated molecule (CD3), and a B-cell associated molecule (CD19) from mononuclear cells (MNCs) in the three compartments. The proportions of CD34+CD38- cells (BM: 4.4+/-2.8%, PB: 5.3+/-2.1%, CB: 5.9+/-3.9%) and CD34+HLA-DR cells (BM: 4.7+/-3.4%, PB: 5.5+/-2.3%, CB: 6.1+/-3.7%) did not differ significantly among the compartments. In contrast, a significantly higher proportion of CD34 cells of PB and CB co-expressed CD13 (75.0+/-11.4%, 77.7+/-17.3%) and CD33 (67.1 +/-5.7%, 56.8+/-10.3%) compared with those of BM (43.0+/-6.3%, 27.6+/-5.1%) and a significantly higher number of granulocyte-macrophage colony-forming units (CFU-GM) and erythroid burst-forming units (BFU-E) were detected in MNCs derived from PB and CB compared with those from BM (p<0.01). The proportion of CD34+CD19+ cells was higher in BM (34.9+/-11.9%) than those in PB (5.6+/-3.0%) and CB (4.7=2.1%) (p<0.05). The proportion of CD34+CD3+ was comparable in all three compartments. In conclusion, our findings show that MNCs of mobilized PB and CB display similar phenotypic profiles of CD34+ subsets and clonogenicity, different from those of BM.

Effect of C-phycocyanin from Spirulina platensis on erythropoiesis in mice / 中国海洋药物

To investigate the effects of C-phycocyanin(C-PC) from Spirulina platensis on erythropoiesis in mice.The colony forming uniterythroid(CFU-E) and burst forming unit-erythroid(BFU-E) were determined using micro-methycellulose culture method in vitro.The erythropoietin(EPO)-like activity of C-PC was examined using the technique of CFU-E culture of fetal liver cells in mice in vitro.Anemic mice models were established by ~(60)Co ?-ray irradiation(5Gy) and intra-peritoneal injected with benzohyarazine hydrochloride.After normal mice were intra-peritoneal injected with C-PC (50 mg?kg~(-1)) for 5d,C-PC provided the only increase in the numbers of CFU-E and BFU-E-derived colonies.C-PC exhibited higher EPO-like activity.12.5 ng of C-PC could match with EPO 1.06U.The specific activity of C-PC was 84,800 U?mg~(-1) C-PC.When anemic mice were intra-peritoneal injected with C-PC for 5d,on d10 the leukocyte,erythrocyte and hemoglobin were significant increased.