OBJECTIVETo explore the phenotype, genotype and molecular mechanism for two pedigrees affected with hereditary antithrombin (AT) deficiency.

METHODSClinical diagnosis was validated by assaying of coagulation parameters including prothrombin time, activated partial thromboplastin time, thrombin time, fibrinogen, antithrombin activity (AT:A) and specific antigen (AT:Ag), protein C activity, as well as protein S activity. To detect potential mutations in the probands, all exons, exon-intron boundaries and the 3', 5' untranslated regions were amplified by PCR and subjected to direct sequencing. Suspected mutation was confirmed by reverse sequencing and silver staining. The effect of mutations on the AT protein was analyzed with bioinformatics software.

RESULTSThe AT:Ag of pedigree 1 was normal, but its AT:A has reduced to 30%. A heterozygous c.235C>T mutation in exon 2 causing p.Arg47Cys, in addition with two single nucleotide polymorphisms (c.981G>A, c.1011G>A) in exon 5 were identified in the patient. His four children, except for the elder daughter, were heterozygous for the mutations. The plasma levels of AT:A and AT:Ag in proband 2 have decreased to 39% and 103 mg/L, respectively. A heterozygous deletion (g.5890-5892delCTT) leading to loss of p.Phe121 was also detected in his father. Bioinformatic analysis suggested that the missense mutation Arg47Cys can affect the functions of AT protein. Meanwhile, lacking of Phe121 will result in loss of hydrogen bonds with Ala124, Lys125 and the cation π interactions with Lys125, Arg47, which may jepordize the stability of the protein.

CONCLUSIONThe proband 1 had type II AT deficiency, while proband 2 had type I AT deficiency. The p.Arg47Cys and g.5890-5892delCTT mutations of the AT gene are significantly correlated with the levels of AT in the two probands, respectively.

Adult ; Aged, 80 and over ; Antithrombin III ; genetics ; metabolism ; Antithrombin III Deficiency ; enzymology ; genetics ; physiopathology ; Exons ; Female ; Genetic Testing ; Genotype ; Humans ; Male ; Mutation ; Partial Thromboplastin Time ; Pedigree ; Phenotype ; Protein C ; genetics ; metabolism ; Protein S ; genetics ; metabolism

OBJECTIVETo study the pattern of DNA double-strand break (DSB) formation in S-phase cells after thermal damage and explore the mechanisms behind heat sensitivity of S-phase cells and delayed DSBs.

METHODSFlow cytometry was used to analyze the cell cycle arrest in H1299 cells exposed to thermal damage, and EdU incorporation assay was employed to evaluate the DNA replication capacity of the cells. The cells synchronized in S phase were obtained by serum starvation and DSBs were observed dynamically using neutral comet assay. Trypan blue dye exclusion technique was used to analyze the cell viability after thermal damage. Western blotting (WB) was used to detect the phosphorylation of ATM and DNA binding RAD18.

RESULTSThe percentage of S-phase cells increased significantly after exposure of the cells to 45 degrees celsius; for 1 h (P<0.01). The time-dependent variation pattern of EdU incorporation was similar to that of S-phase cell fraction. The comet tail began to appear only after incubation of the cells at 37 degrees celsius; for some time and the Olive tail moment (OTM) increased with prolonged incubation. Cell death remained low until 7.5 h after heat exposure of the S-phase cells and then increased rapidly. The phosphorylation of ATM first increased but then decreased drastically. In cells with heat exposure, DNA binding RAD18 was attenuated obviously compared that in non-exposed cells.

CONCLUSIONThermal damage causes cell cycle arrest in S phase, and delayed fatal DSBs occur in the arrested cells due to persistent replication and DNA damage repair suppression, which are the possible cause of heat sensitivity of S-phase cells.

Ataxia Telangiectasia Mutated Proteins ; metabolism ; Cell Cycle Checkpoints ; Cell Line ; Cell Survival ; Comet Assay ; DNA Breaks, Double-Stranded ; DNA Repair ; DNA Replication ; DNA-Binding Proteins ; metabolism ; Hot Temperature ; Humans ; Phosphorylation ; S Phase ; Ubiquitin-Protein Ligases

OBJECTIVETo explore the high risk factors of thrombosis in paroxysmal nocturnal hemoglobinuria (PNH). It has been reported that in Chinese patients with venous thrombosis, the mutation frequency in PROC c.574_576 del (rs199469469), PROC c.565C>T (rs146922325) and THBD c.-151G>T (rs1698852) was higher than that of normal controls, indicating its importance in thrombophilia pathogenesis.

METHODS142 patients with PNH diagnosed between 2009 and 2015 were enrolled in the study. Clinical data were analyzed and thrombophilia risk factors, such as the level of protein C, protein S, antithrombin III, APC resistance, blood fat, phospholipid antibody, were evaluated. Samples from patients and 100 normal controls were detected for the mutations of PROC c.574_576 del (rs199469469), PROC c.565C>T (rs146922325) and THBD c.-151G>T (rs1698852) by Sanger sequence.

RESULTSOf the 142 PNH patients, 21 (14.8%) patients had at least 1 episode of thrombotic event. Only 2 patients had arterial thrombosis and 19 patients had venous thrombosis. The median age of patients with thrombosis was 35 years old, similar to those without episode (40 years old, P=0.687). The ratios of males and females were 1.33 in thrombosis group and 1.57 in non-thrombosis group (P=0.728) , respectively. Patients with thrombosis had the same disease pattern compared with those without episode. Although there was no difference in the level of hemoglobin, WBC and PLT count, and LDH level between patients with thrombosis and those without episode, patients with thrombosis showed higher RBC, higher percentage of CD59(-) granulocytes and RBC, and Flaer(-) granulocytes compared with those without episode. The routine thrombophilia screening tests did not show any difference either between PNH patients and normal controls, or between patients with or without thrombosis. There were two mutations in rs199469469 and rs16984852 sites in patients with PNH, but the mutated patients did not have any thrombosis. Mutation rs146922325 was found in PNH patients. The mutation rate was similar between PNH patients and normal controls, thrombotic PNH and non-thrombotic PNH (P>0.05).

CONCLUSIONSCompared with non-thrombotic patients, PNH thrombotic patients have bigger PNH clone and higher RBC count. There are no differences among the routine thrombophilia factors and the three known venous eligible genes either between PNH patients and normal controls or between thrombotic and non-thrombotic PNH patients.

Adult ; Antithrombin III ; metabolism ; Case-Control Studies ; Clone Cells ; cytology ; Female ; Granulocytes ; cytology ; Hemoglobinuria, Paroxysmal ; genetics ; physiopathology ; Humans ; Leukocyte Count ; Male ; Protein C ; metabolism ; Protein S ; metabolism ; Risk Factors ; Thrombosis ; genetics ; physiopathology

Thrombophilia that is common among Caucasians is caused by genetic polymorphisms of coagulation factor V Leiden (R506Q) and prothrombin G20210A. Unlike that in Caucasians, thrombophilia that is common in the Japanese and Chinese involve dysfunction of the activated protein C (APC) anticoagulant system caused by abnormal protein S and protein C molecules. Approximately 50% of Japanese and Chinese individuals who develop venous thrombosis have reduced activities of protein S. The abnormal sites causing the protein S molecule abnormalities are distributed throughout the protein S gene, PROS1. One of the most common abnormalities is protein S Tokushima (K155E), which accounts for about 30% of the protein S molecule abnormalities in the Japanese. Whether APC dysfunction occurs in other Asian countries is an important aspect of mapping thrombophilia among Asians. International surveys using an accurate assay system are needed to determine this.
Asian Continental Ancestry Group ; Blood Coagulation ; Blood Proteins/genetics/metabolism ; Humans ; Protein C/genetics/*metabolism ; Protein S/chemistry/genetics/metabolism ; Thrombophilia/epidemiology/*etiology ; Venous Thrombosis/etiology/genetics

OBJECTIVETo explore the tumor growth inhibition of gamma secretase inhibitor MRK003 on human multiple myeloma xenograft mice by inhibition of AKT and Notch1 expression.

METHODSNOD/SCID mice were injected with human multiple myeloma cell lines RPMI8226 to establish a xenograft mouse model. Mice were randomized into two groups：the experimental group were injected with MRK003 at a dose of 5 mg× kg⁻¹×d⁻¹ for 14 days; the inhibitor was replaced by an equal saline in the control group. Mice were sacrificed by cervical dislocation on the next day after the last injection and tumor tissue was removed to detect the expression of Notch1 and AKT by immunohistochemistry.

RESULTSAfter subcutaneous injection with RPMI8226, mice had tumor formation in 5-7 days and the largest tumor block in 10-12 days. Before RPMI8226 injection, the mean sizes of tumor block in the experimental and the control groups were 509.2 mm³, 511.2 mm³(P>0.05). 9 days after injection, the mean sizes of tumor tissue in the experimental and the control groups were 636.6 mm³, 691.2 mm³(P<0.01). On the next day after the last injection, the tumor sizes of the experimental and the control groups were 683.5 mm³ and 1798.7 mm³(P<0.01). The size of tumor block in the experimental group was significantly smaller than that of the control group(P<0.01). Immunohistochemistry staining showed that the positive expression rates of Notch1(11.1%, P<0.01) and AKT(13.3%, P<0.01) in experimental group were significantly decreased compared with the control group(Notch1: 95.6%; AKT: 93.3%). Western blot results showed that Notch1 and AKT protein in experimental group were significantly lower than those in the control group.

CONCLUSIONMRK003 could inhibit the tumor growth of human multiple myeloma xenograft mice by downregulated expression of Notch1 signaling pathway.

Amyloid Precursor Protein Secretases ; antagonists & inhibitors ; Animals ; Cell Line, Tumor ; Cyclic S-Oxides ; pharmacology ; Humans ; Mice ; Mice, Inbred NOD ; Mice, SCID ; Multiple Myeloma ; drug therapy ; metabolism ; Proto-Oncogene Proteins c-akt ; metabolism ; Receptor, Notch1 ; metabolism ; Signal Transduction ; drug effects ; Thiadiazoles ; pharmacology ; Xenograft Model Antitumor Assays

OBJECTIVETo explore the distribution and influence factors of protein C (PC), protein S (PS) and antithrombin (AT) activities and to determine the prevalence of their deficiencies in the Chinese Han healthy population.

METHODSHealthy volunteers including blood donors and individuals for routine check-up were recruited from 4 Chinese medical centers. The plasma levels of PC, PS and AT activities were measured. The plasma levels of activities were measured by chromogenic substrate assay (AT and PC) and clotting assay (PS).

RESULTSA total of 3493 healthy Chinese adults had been recruited in this study. Males had higher PS and PC activities than females, especially for PS (P < 0.01). PC activities increased with age in both sexes but decreased in men after 50 years old. There was no significant change with age were of PS in 50 years old, while there was a decline in males and a rise in females above 50 years old. AT tended to increase with age in women but decreased with age in men after 50 years old. Based on the age and gender, the general prevalence of PC, PS and AT deficiencies in the general Chinese Han population were 1.15%, 1.49% and 2.29%, respectively.

CONCLUSIONPC, PS and AT activities have correlation with age and gender in Chinese Han population. Reference range should be laid down and deficiencies should be identified

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Antithrombin III ; metabolism ; Antithrombin III Deficiency ; epidemiology ; Antithrombins ; metabolism ; Asian Continental Ancestry Group ; Female ; Humans ; Male ; Middle Aged ; Plasma ; metabolism ; Prevalence ; Protein C ; metabolism ; Protein C Deficiency ; epidemiology ; Protein S ; metabolism ; Protein S Deficiency ; epidemiology ; Young Adult

Nucleophosmin/B23 (NPM) is a universally expressed nucleolar phosphoprotein that participates in proliferation, apoptosis, ribosome assembly, and centrosome duplication; however, the role of NPM in cell cycle regulation is not well characterized. We investigated the mechanism by which NPM is involved in cell cycle regulation. NPM was knocked down using siRNA in HepG2 hepatoblastoma cells. NPM translocation following actinomycin D (ActD) treatment was investigated using immunofluorescent staining. Expression of NPM and other factors involved in cell cycle regulation was examined by Western blotting. Cell cycle distribution was measured using flow cytometry to detect 5-ethynyl-2'-deoxyuridine (EdU) incorporation. Cell proliferation was quantified by the MTT assay. Knockdown of NPM increased the percentage of HepG2 cells in S phase and led to decreased expression of P53 and P21Cip1/WAF1. S-phase arrest in HepG2 cells was significantly enhanced by ActD treatment. Furthermore, knockdown of NPM abrogated ActD-induced G2/M phase cell cycle arrest. Taken together, these data demonstrate that inhibition of NPM has a significant effect on the cell cycle.
Antibiotics, Antineoplastic ; pharmacology ; Cell Cycle ; Cell Proliferation ; Cyclin-Dependent Kinase Inhibitor p21 ; metabolism ; Dactinomycin ; pharmacology ; Gene Knockdown Techniques ; Hep G2 Cells ; Humans ; Nuclear Proteins ; genetics ; metabolism ; RNA, Small Interfering ; S Phase ; Tumor Suppressor Protein p53 ; metabolism

OBJECTIVETo study the correlation of activated protein C (APC) resistance, coagulation factors and inhibitors abnormality and JAK2V617F mutation burden in patients with myeloproliferative neoplasms (MPN).

METHODSThe APC resistance was defined as the ratio of activated partial thromboplastin time (APTT) in the presence and absence of APC, i.e. APC sensitivity ratio (APCsr). Plasma protein C (PC), protein S (PS), prothrombin (FII), factor V (FV), factor VIII levels and CD11b expression on neutrophils were measured. The percentage of mutated JAK2V617F allele (V617F%) was evaluated by real time polymerase chain reaction (qRT-PCR).

RESULTSExpression of CD11b on neutrophils was significantly elevated in MPN patients compared with that of the control group. APCsr, PS and FV levels were reduced in patients with MPN. The APCsr level was decreased mainly in patients with thrombosis and JAK2V617F mutant burden higher than 75%. APCsr was not only positively correlated with PS levels but also inversely correlated with JAK2V617F allele burden in JAK2V617F mutant gene carriers.

CONCLUSIONThe neutrophil was activated and PS, FV level were reduced in MPN patients. The APCsr level was decreased and the occurrence of relatively acquired APC resistance was found in MPN patients with thrombosis. The APCsr is correlated with the PS level and JAK2V617F mutational furden.

Activated Protein C Resistance ; metabolism ; Adolescent ; Adult ; Aged ; Blood Coagulation ; Blood Coagulation Disorders ; Factor V ; metabolism ; Female ; Humans ; Male ; Middle Aged ; Myeloproliferative Disorders ; blood ; metabolism ; Protein S ; metabolism ; Young Adult

In eukaryotic cells, DNA damage triggers activation of checkpoint signaling pathways that coordinate cell cycle arrest and repair of damaged DNA. These DNA damage responses serve to maintain genome stability and prevent accumulation of genetic mutations and development of cancer. The p38 MAPK was previously implicated in cellular responses to several types of DNA damage. However, the role of each of the four p38 isoforms and the mechanism for their involvement in DNA damage responses remained poorly understood. In this study, we demonstrate that p38γ, but not the other p38 isoforms, contributes to the survival of UV-treated cells. Deletion of p38γ sensitizes cells to UV exposure, accompanied by prolonged S phase cell cycle arrest and increased rate of apoptosis. Further investigation reveal that p38γ is essential for the optimal activation of the checkpoint signaling caused by UV, and for the efficient repair of UV-induced DNA damage. These findings have established a novel role of p38γ in UV-induced DNA damage responses, and suggested that p38γ contributes to the ability of cells to cope with UV exposure by regulating the checkpoint signaling pathways and the repair of damaged DNA.
Animals ; Apoptosis ; Cell Cycle Proteins ; metabolism ; Cells, Cultured ; DNA Damage ; DNA Repair ; Enzyme Activation ; Fibroblasts ; metabolism ; radiation effects ; Gene Deletion ; Histones ; metabolism ; Mice ; Mitogen-Activated Protein Kinase 12 ; genetics ; metabolism ; Phosphorylation ; S Phase ; Tumor Suppressor Protein p53 ; metabolism ; Ultraviolet Rays

OBJECTIVETo investigate the prevalence and the risk of natural anticoagulants such as plasma protein C (PC), protein S (PS) and antithrombin (AT) deficiency in thromboembolic patients with no evident acquired factors.

METHODSClotting assays on French STAGO autoanalyzer were used to detect the activity of plasma PC, PS and AT in 85 patients with thrombotic disease and 50 sex and age matched healthy controls.

RESULTSAmong the 85 enrolled patients (18 arterial and 67 venous thromboembolism), male to female ratio was 1.4 and the median age was 42 years (17-69). The activity of plasma PC, PS and AT in the pre-therapy thrombotic disease group, the thrombo-recurrence group, and the age < or = 45 years group were significantly lower than that is the healthy control group, the first thrombotic episodes group and the age > 45 years group respectively (P < 0.001, P < 0.01, P < 0.01). The overall deficiency rate of these three natural anticoagulants was 30.6%, PS deficiency was the commonest (10.6%), the second was PC deficiency (8.2%), AT deficiency and combined deficiency each accounted for 5.9%.

CONCLUSIONThe PC, PS and AT protein deficiencies are frequent in Chinese thromboembolic patients, they are the independent risk factors for the thrombotic events and recurrence.

Adolescent ; Adult ; Aged ; Antithrombins ; blood ; Case-Control Studies ; Female ; Humans ; Male ; Middle Aged ; Protein C ; metabolism ; Protein C Deficiency ; blood ; Protein S ; metabolism ; Protein S Deficiency ; blood ; Risk Factors ; Thrombosis ; blood ; etiology ; Young Adult