T-cell acute lymphoblastic leukemia (T-ALL) is the hematological malignancy of bone marrow characterized by the rapid proliferation and subsequent accumulation of immature T lymphocyte and mainly occurs in children and adolescents. In 1991, a kind of activating mutation of Notch 1 was found in a subset of T-ALL with chromosomal translocation t(7;9) for the first time. During the past 20 years since then, understanding of the relationship between Notch 1 activating mutation and T-ALL has been deepened and widened. This review briefly discusses the four main subtypes of Notch 1 activating mutations, also focuses on how these mutations change the normal signaling pathways and genes expression during their participation in the pathogenesis of T-ALL, and how these insights will promote the development of newly targeting therapies for patients with this aggressive form of leukemia.
Humans ; Mutation ; Precursor T-Cell Lymphoblastic Leukemia-Lymphoma ; etiology ; genetics ; Receptor, Notch1 ; genetics

OBJECTIVETo observe the effects of pravastatin on platelet-derived nitric oxide system in hypercholesterolemia (HC) and atherosclerosis (AS) in rabbits, and the relationship between these changes and atherosclerosis courses.

METHODSThirty male New Zealand white rabbits were randomly divided into three groups, 12 in group A, 12 in group B, and 6 in group C. All of them were fed daily with cholesterol-rich food during the first 12 weeks. In addition, in group A, pravastatin (10 mg) was orally administered daily. At the end of the 12th week, 6 in group A and B were killed randomly and their aortas were removed and the pathologic changes were observed. In the following 12 weeks, food enriched with cholesterol was substituted with normal food in all three groups. Pravastatin treatment was continued or started in the remaining members of group A and group B, but not in group C. At the end 24th week, all rabbits were killed and their aortas were examined for the fatty-streaks or atherosclerotic plaques. The expressions of endothelial NOS (eNOS) mRNA and inducible NOS (iNOS ) mRNA, NOS activity, NO production and the level of the serum lipids were measured at 0, 6th, 12th, 18th and 24th week.

RESULTSThe expression levels of platelet-derived NOS mRNA, eNOS mRNA ratio in group A had no difference at above time points, while in group B were reduced significantly at 6th week and 12th week compared with at 0 week (P <0.01), and increased at 18th week and 24th week compared with 12th week (P <0.05). The expression levels of eNOS mRNA in group C were reduced at 6th, 12th and 18th, 24th week compared with 0 week (P <0.05 and P <0.01, respectively), and were reduced in groups B and C compared with group A at 6th ,12th week (P < 0.05) and increased in group A and B compared with group C at 18th, 24th week (P <0.01). The expression levels of iNOS/mRNA among the three groups had no difference. Pathologic finding of the arteries: AS was not found in group A from the 12th to 24th week. While in group B, there were a lot of fatty-streaks on the entire intima of all large arteries at the 12th week. There were also fatty-streaks in the ascending aorta, but were improved at the 24th week. In group C, there were marked plaques in the entire aorta at the 24th week.

CONCLUSIONSThe expressions of platelet-derived eNOS mRNA, NOS activity, NO production are decreased in HC or AS rabbits. Pravastatin can up-regulate expressions of platelet-derived eNOS mRNA, NOS activity, leading to preventing or improving the pathological courses of AS.

Animals ; Atherosclerosis ; blood ; pathology ; Blood Platelets ; metabolism ; Disease Models, Animal ; Male ; Nitric Oxide ; blood ; genetics ; Nitric Oxide Synthase ; blood ; genetics ; Pravastatin ; pharmacology ; RNA, Messenger ; genetics ; Rabbits

OBJECTIVETo explore the effects of 2A-1-1 (purified component from Panax notoginsengs saponins) on the aggregation of and Ca2+ influx into human platelets.

METHODSThe aggregation of platelets was tested by nephelometry, Fura-2 fluorescent technique was used for detecting cell [Ca2+]i. The effects of 2A-1-1, nifedipine and SK&F96365 on Ca(2+) influx into human platelets induced by ADP or CPA were observed separately.

RESULTSNifedipine (< 20 micromol/L) could not inhibit platelet aggregation induced by ADP or the Ca(2+) influx induced by ADP or CPA. SK&F96365 at 20 micromol/L could inhibit the maximal aggregation of platelets induced by ADP with a inhibitory rate of 59.83%, at 15 micromol/L could inhibit the Ca2+ influx induced by CPA or ADP. 2A-1-1 (5, 10 and 20 micromol/L) could inhibit the maximal aggregation of platelets induced by ADP with the inhibitory rates of 47.06%, 53.47% and 71.52%, respectively. 2A-1-1 at 10 and 20 micromol/L could inhibit the Ca2+ influx induced by CPA or ADP.

CONCLUSIONS2A-1-1 can inhibit platelets aggregation, block the ROC (Receptor-dependent Ca2+ channels) and inhibit Ca2+ influx of human platelets.

Adenosine Diphosphate ; pharmacology ; Adult ; Blood Platelets ; cytology ; drug effects ; metabolism ; Calcium ; metabolism ; pharmacokinetics ; Calcium Channel Blockers ; pharmacology ; Dose-Response Relationship, Drug ; Female ; Ginsenosides ; pharmacology ; Humans ; Imidazoles ; pharmacology ; Indoles ; pharmacology ; Male ; Nifedipine ; pharmacology ; Platelet Aggregation ; drug effects ; Platelet Aggregation Inhibitors ; pharmacology

OBJECTIVETo explore the effects of basic fibroblast growth factor (bFGF) on human bone marrow mesenchymal stem cell (hBMMSC) damaged by irradiation and its underlying mechanisms.

METHODShBMMSC was irradiated with 0, 6, 12 Gy X ray, then flow cytometry, cell counting kit-8 (CCK-8), Western blot and alizarin red staining were used to detect the effects of X ray on apoptosis, proliferation and osteogenic differentiation of hBMMSC; 0, 1, 5, 10, 20 ng/ml bFGF was added to hBMMSC irradiated with X ray for selecting the suitable bFGF reaction concentration; then the Western blot was used to detect the expression of PDGFRα so as to evaluate whether the expression of PDGFRα participated in bFGF-mediated recovery of hBMMSC proliferation and osteogenic differentiation after irradiation.

RESULTSThe proliferation and osteogenic differentiation of hBMMSC decreased remarkably after irradiation. bFGF promoted the recovery of proliferation and osteogenic differentiation of irradiated hBMMSC compared with untreated irradiated hBMMSC (P < 0.05); 5 ng/ml bFGF was identified as the optimal concentration. A significant difference in the number of apoptotic cells could be detected only between the 0 Gy group and 12 Gy group at the 24 h time point, while no differences were detected at later time points. Irradiated hBMMSC showed remarkable decrease of PDGFRα expression, while the PDGFRα expression increased after bFGF was added.

CONCLUSIONIrradiation dose not show significant effect on apoptosis of hBMMSC, but the bFGF displays a effect on repairing the irradiation damage of hBMMSC and promotes the recovery of hBMMSC proliferation and osteogenic differentiation. The damage of hBMMSC proliferation and osteogenic differentiation associates with downregulation of PDGFRα expression induced by irrediation. PDGFRα involves in repairing effect of bFGF on irradiation damage of hBMMSC.

Apoptosis ; Bone Marrow Cells ; Cell Differentiation ; Cell Proliferation ; Cells, Cultured ; Fibroblast Growth Factor 2 ; Humans ; Mesenchymal Stromal Cells ; Osteogenesis ; Receptor, Platelet-Derived Growth Factor alpha

BACKGROUND: Zinc finger and BTB domain-containing protein 46 (Zbtb46) is a transcription factor identified in classical dendritic cells, and maintains dendritic cell quiescence in a steady state. Zbtb46 has been reported to be a negative indicator of acute myeloid leukemia (AML). We found that Zbtb46 was expressed at a relatively higher level in hematopoietic stem and progenitor cells (HSPCs) compared to mature cells, and higher in AML cells compared to normal bone marrow (BM) cells. However, the role of Zbtb46 in HSPCs and AML cells remains unclear. Therefore, we sought to elucidate the effect of Zbtb46 in normal hematopoiesis and AML cells. METHODS: We generated Zbtb46 and Zbtb46Mx1-Cre mice. The deletion of Zbtb46 in Zbtb46Mx1-Cre mice was induced by intraperitoneal injection of double-stranded poly (I). poly (C) (poly(I:C)), and referred as Zbtb46 cKO. After confirming the deletion of Zbtb46, the frequency and numbers of HSPCs and mature blood cells were analyzed by flow cytometry. Serial intraperitoneal injection of 5-fluorouracil was administrated to determine the repopulation ability of HSCs from Zbtb46 and Zbtb46 cKO mice. The correlation between Zbtb46 expression and prognosis was analyzed using the data from the Cancer Genome Atlas. To investigate the role of Zbtb46 in AML cells, we knocked down the expression of Zbtb46 in THP-1 cells using lentiviral vectors expressing small hairpin RNAs targeting Zbtb46. Cell proliferation rate was determined by cell count assay. Cell apoptosis and bromodeoxyuridine incorporation were determined by flow cytometry. RESULTS: The percentages and absolute numbers of HSPCs and mature blood cells were comparable in Zbtb46 cKO mice and its Zbtb46 littermates (Zbtb46vs. Zbtb46 cKO, HPC: 801,310 ± 84,282 vs. 907,202 ± 97,403, t = 0.82, P = 0.46; LSK: 86,895 ± 7802 vs. 102,210 ± 5025, t = 1.65, P = 0.17; HSC: 19,753 ± 3116 vs. 17,608 ± 3508, t = 0.46, P = 0.67). The repopulation ability of HSCs from Zbtb46Mx1-Cre mice was similar to those from Zbtb46 control (P = 0.26). Zbtb46 had elevated expression in AML cells compared to total BM cells from normal control. Knockdown of Zbtb46 in THP-1 cells led to a significant increase in cell apoptosis and reduced cell growth and proliferation. CONCLUSION Collectively, our data indicate that Zbtb46 is essential for survival and proliferation of AML cells, but dispensable for normal hematopoiesis.