OBJECTIVE: To explore the functional roles and underlying mechanisms of neferine in the context of angiotensin II (Ang II)-induced hypertension and vascular dysfunction. METHODS: Male mice were infused with Ang II to induce hypertension and randomly divided into treatment groups receiving neferine or a control vehicle based on baseline blood pressure using a random number table method. The hypertensive mouse model was constructed by infusing Ang II via a micro-osmotic pump (500 ng/kg per minute), and neferine (0.1, 1, or 10 mg/kg), valsartan (10 mg/kg), or double distilled water was administered intragastrically once daily for 6 weeks. A non-invasive blood pressure system, ultrasound, and hematoxylin and eosin staining were performed to assess blood pressure and vascular changes. RNA sequencing and network pharmacology were employed to identify differentially expressed transcripts (DETs) and pathways. Vascular ring tension assay was used to test vascular function. A7R5 cells were incubated with neferine for 24 h and then treated with Ang II to record the real-time Ca²⁺ concentration by confocal microscope. Immunohistochemistry (IHC) and Western blot were used to evaluate vasorelaxation, calcium, and the extracellular signal-regulated kinase (ERK)1/2 pathway. RESULTS: Neferine treatment effectively mitigated the elevation in blood pressure, pulse wave velocity, aortic thickening in the abdominal aorta of Ang II-infused mice (P<0.05). RNA sequencing and network pharmacology analysis identified 355 DETs that were significantly reversed by neferine treatment, along with 25 potential target genes, which were further enriched in multiple pathways and biological processes, such as ERK1 and ERK2 cascade regulation, calcium pathway, and vascular smooth muscle contraction. Further investigation revealed that neferine treatment enhanced vasorelaxation and reduced Ca²⁺-dependent contraction of abdominal aortic rings, independent of endothelium function (P<0.05). The underlying mechanisms were mediated, at least in part, via suppression of receptor-operated channels, store-operated channels, or voltage-operated calcium channels. Neferine pre-treatment demonstrated a reduction in intracellular Ca²⁺ release in Ang II stimulated A7R5 cells. IHC staining and Western blot confirmed that neferine treatment effectively attenuated the upregulation of p-ERK1/2 both in vivo and in vitro, which was similar with treatment of ERK1/2 inhibitor PD98059 (P<0.05). CONCLUSIONS Neferine remarkably alleviates Ang II-induced elevation of blood pressure, vascular dysfunction, and pathological changes in the abdominal aorta. This beneficial effect is mediated by the modulation of multiple pathways, including calcium and ERK1/2 pathways.
Animals ; Angiotensin II ; Male ; Benzylisoquinolines/therapeutic use* ; Network Pharmacology ; Blood Pressure/drug effects* ; Sequence Analysis, RNA ; Mice ; Hypertension/chemically induced* ; Mice, Inbred C57BL ; Calcium/metabolism*

OBJECTIVE: To develop monoclonal antibodies that can specifically recognize human von Willebrand factor (VWF) propeptide (VWFpp) in plasma, and establish a rapid and reliable method for the detection of VWFpp antigen in plasma by using the double-antibody sandwich ELISA with the obtained anti-VWFpp monoclonal antibody. METHODS: The recombinant human VWFpp (D1 and D2 regions) protein expressed in eukaryotic cells was used as immunogen to immunize BALB/c mice with routine method, so as to obtain clones of fusion cells. After screening and identification, hybridoma cell lines secreting monoclonal antibodies against VWFpp were selected, and then double-antibody sandwich ELISA assay was used to construct VWFpp antigen detection kit for the determination of VWFpp in human plasma. The levels of VWFpp antigen in plasma of 12 leukemia patients who underwent bone marrow transplantation were dynamically detected. RESULTS: Two hybridoma cell lines that can be subcultured continuously and secrete monoclonal antibodies against VWFpp were obtained and named SZ175 and SZ176 respectively. Identified by ELISA and Western blot, the antibodies could both specifically recognize VWFpp but couldn't recognize mature VWF (without propeptide). Based on the principle of double-antibody sandwich ELISA, monoclonal antibodies SZ175 and SZ176 were successfully made into a kit for detecting VWFpp antigen. The plasma VWFpp levels of leukemia patients before and after bone marrow transplantation were dynamically detected. The results showed that the plasma VWFpp levels of the patients after transplantation were significantly higher than those before transplantation. CONCLUSION Two monoclonal antibodies against VWFpp were successfully prepared, and a double-antibody sandwich ELISA detection kit for VWFpp antigen was constructed, which provides a powerful tool for further study on the biological function of VWFpp, the clinical diagnosis and classification of von Willebrand disease (VWD), and the prognostic monitoring of endothelial injury-related diseases.
Animals ; Mice ; Humans ; von Willebrand Factor ; Antibodies, Monoclonal ; Protein Precursors/metabolism* ; von Willebrand Diseases/diagnosis* ; Prognosis

OBJECTIVE: To obtain the recombinant protein of spacer domain in von Willebrand factor cleaving protease (ADAMTS13), and further study its biological function in ADAMTS13. METHODS: The prokaryotic expression vector was constructed by using the template of plasmid with full-length ADAMTS13, and then transfected into E coli., following the induction of IPTG with the low temperature (30 ℃). The recombinant protein was purified with Ni-NTA agarose column by gradient imidazole. The purity and immune activity of purified products were identified with SDS-PAGE and Western blot respectively. By Adding the recombinant protein to the plasma of immune-mediated thrombotic thrombocytopenic purpura (iTTP) patients, the activity of ADAMTS13 was tested. RESULTS: The prokaryotic expression vector was successfully constructed and the protein of spacer domain with the high purity was obtained. Western blot showed that the recombinant fragment could both react with monoclonal antibody against 6×His and polyclonal sheep IgG against ADAMTS13 (Gln34-Trp688). The protein formed a main lane at the position of 15 kDa with SDS-PAGE. It was demonstrated that the recombinant protein could efficiently elevate the ADAMTS13 activity in plasma of iTTP patients to reach normal level by functional experiment. CONCLUSION The recombinant protein has high purity and immune activity, which provides the experimental basis for further research on mechanism of iTTP involved in spacer domain.
ADAM Proteins ; ADAMTS13 Protein ; Animals ; Escherichia coli ; Humans ; Purpura, Thrombotic Thrombocytopenic ; Recombinant Proteins ; Sheep ; von Willebrand Factor

OBJECTIVETo establish the hybridoma cell lines secreting anti-ADAMTS13-T7 monoclonal antibodies (MA6) and to construct the MAb directed against different domains of ADAMTS13-T7.

METHODSThe trucated type protein ADAMTS13 of eukaryote-expressed recombinant ADAMTS13-T7 was constructed and was purified by using Ni-NTA agarose. Then the purified ADAMTS13 was used to immunize the BALB/c mice; the antiserum titer of ADAMTS13 protein of immunized mice was deteceted by ELISA. The spleen was taken from mice for construcing the single cell suspension, then the single cell suspension was mixed with myeloma cells SP2/0 at 10:1 ratio for cell fusion, and the elution culture of hybridoma cells was carried out; after 2 weeks, the wells in which clones were well grown were selected for detection, then the positive clonal wells were expansively cultured and the detection again was performed.

RESULTSThe purified ADAMTS13-T7 protein was gained. The ELISA showed that the antiserum titer in mice immumized by ADAMTS13-T7 protein was 1:20000. The results of fusion culture by hybridoma techmique showed that 30 hyridoma cell lines secreting MAb against recombinant ADAMTS13 were established.

CONCLUSIONThe hybridoma cell lines secreting MAb against recombinant ADAMTS13 have been successfully established by fusion culture, which provide more powerful tools for further screening the MAb with certain functional activity and studying the structure and function of ADAMTS13.

OBJECTIVETo construct and identify the monoclonal antibodies against von willebrand factor cleaving protease(ADAMTS13), and to study their biological function.

METHODSBALB/c mice were immunized by purified recombinant ADAMTS13 truncated eukaryotic protein (ADAMTS13-T7). Murine anti-human ADAMTS13 monoclonal antibodies (McAbs) were constructed by standard hybridoma technology and identified by ELISA. The recognition of McAbs with full-length recombinant ADAMTS13 protein was identified by Western blot. In function assay, the influence of McAbs on the proteolysis of vWF by ADAMTS13 was observed.

RESULTSA group of 6 murine anti-ADAMTS13 McAbs was obtained with the clone number 1G11, 2F11, 6G3, 9E1, 10A8 and 10B4. In ELISA, the highest titers of 1G11 and 2F11 were observed, both of which showed a higher affinity to ADAMTS13-T7 than full-length ADAMTS13. The Western blot demonstrated that the 6 McAbs all could recognize ADAMTS13, among which 1G11 and 2F11 showed stronger reaction with ADAMTS13. In addition, under the denatured conditions, 1G11 and 2F11 could inhibit hydrolysis of vWF by ADAMTS13, and that was stronger with the increasing of McAbs concentration.

CONCLUSIONMcAbs against ADAMTS13 have been gained, two of which are inhibitory antibodies.

ADAMTS13 Protein ; Animals ; Antibodies, Monoclonal ; analysis ; immunology ; Blotting, Western ; Enzyme-Linked Immunosorbent Assay ; Hybridomas ; Mice ; Mice, Inbred BALB C ; von Willebrand Factor

This study was aimed to summarize and analyze the morphology, immunophenotype, cytogenetics, molecular biology (MICM), tyrosine kinase (TK) gene mutations and clinical features of acute myeloid leukemia (AML) with complex variant of t(8;21). A retrospective study was performed for 20 AML patients with complex variant of t(8;21) in our hospital from January 1994 to April 2012, including analysis of clinical feature, immunophenotype, chromosome karyotype, treatment regimen, as well as the overall survival (OS) and relapse-free survival (RFS). Mutations of C-KIT, FLT3-ITD, FLT3-TKD and JAK2V617F were detected by genomic DNA PCR and the sequencing was per-formed in 13 AML patients with complex variant of t(8;21). The results showed that (1) the incidence of 20 AML patients with complex variant of t(8; 21) was 2.4% of total t(8; 21) AML patients. In 20 AML patients with complex variant of t(8;21), 1 case was M1, 17 cases were M2, 2 cases were M4; 10 cases were myeloid phenotype and the other 3 were myeloid plus lymphoid phenotype. There were 16 kinds of cytogenetics additional involvement of chromosomal breakpoints: lp22, 1p32, 2q35, 2q14, 3p25, 5q13, 6p22, 7q21, llq11, 1lq13, 12q14, 12q24, 12p12, 14q32, 15p13, 20q12. (2) C-KIT aberrations were detected in 30.8% cases, all mutated in exon 17 (mutkit 17), only 1 case had JAK2V617F mutation. The result of FLT3 mutation screenings in AML patients with complex variant of t(8; 21) was negative. Of 5 patients with gene mutations, 1 patient (20%) achieved complete remission (CR), the median RFS and median OS time were 6.5 months and 8.9 months respectively. Of the 8 patients without gene mutations, 6 patietns (75%) achieved CR; the median RFS and median OS time were 26.6 months and 27.7 months respectively. It is concluded that the AML patients with complex variant of t(8;21) shows typical features of t(8;21) AML, but the existence of the tyrosine kinase-related gene mutation has important implications on remission rate and long-term survival of patients treated by induction chemotherapy.
Adolescent ; Adult ; Aged ; Chromosomes, Human, Pair 21 ; Chromosomes, Human, Pair 8 ; DNA Mutational Analysis ; Female ; Humans ; Leukemia, Myeloid, Acute ; genetics ; Male ; Middle Aged ; Protein-Tyrosine Kinases ; genetics ; Retrospective Studies ; Translocation, Genetic ; Young Adult

OBJECTIVETo investigate the molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) isolates from Chinese children in seven cities.

METHODA total of 134 MRSA isolates were collected from nine hospitals. Multilocus sequence typing and spa typing were analyzed by polymerase chain reaction (PCR), and staphylococcal chromosomal cassette mec (SCCmec) type was analyzed by multiplex PCR. The Panton-Valentine leukocidin (pvl) gene was also detected.

RESULTMost MRSA strains were isolated from pneumonia and skin and soft tissue infection (SSTIs) patients, accounting for 82.1%. Overall, 16 sequence types (STs) were obtained, and CC59 (51.7%) was found to be the most prevalent, which included ST 59 and ST 338, followed by ST239 (16.4%). SCCmec types II, III, IV, and V were also identified in the current study. SCCmec type IV was the most predominant type at 50.0%, followed by SCCmec type V at 23.9% and III at 23.9%. SCCmec subtypes IVa, IVc, and IVg were found among SCCmec type IV strains, whereas IVa was the main subtype at 77.6%. Twenty-six spa types were also identified, among which the predominant type was t437 (47.8%). The prevalence of pvl genes and the SCCmec type of strain was relevant, and the pvl gene positive rate was higher in SCCmec type IV and V-type strains than in SCCmec type II and III strains (58.6% vs. 14.3%, P < 0.05); there was a significant difference between them. In the strains isolated from pneumonia and SSTIs, ST59-MRSA-IVa(t437) was the predominant clone. There were five clones detected from the strains isolated from septicemia, with ST59-MRSA-IVa(t437) and ST59-MRSA-V(t437) as the main clones (57.1%). Various predominant clones existed in different regions. ST59-MRSA-IVa(t437) was the prevalent clone in the Guangzhou, Beijing, Chongqing, and Shenzhen areas, whereas ST239-MRSA-III(t037) was the prevalent clone in the Shanghai area. Fifty percent of the isolates from the Wenzhou area belonged to ST910-MRSA-V(t318), whereas three clinical strains isolated from the Shenyang region belonged to three different types.

CONCLUSIONThe results indicate that MRSA isolates from Chinese children are largely associated with the ST59-MRSA-IV(t437) and ST239-MRSA-III(t037) clones. These two may belong to community-acquired MRSA and hospital-acquired ones, respectively. Different prevalent clones were detected in different diseases and different regions. Therefore, there is a need to conduct further research on clinical isolates, which can guide the choice of antibiotic treatment and the examination of MRSA prevalence.

Adolescent ; Bacterial Typing Techniques ; Child ; Child, Preschool ; China ; epidemiology ; DNA, Bacterial ; genetics ; Female ; Humans ; Infant ; Infant, Newborn ; Male ; Methicillin-Resistant Staphylococcus aureus ; classification ; genetics ; isolation & purification ; Prevalence ; Staphylococcal Infections ; epidemiology ; microbiology

OBJECTIVETo study the expression of annexin II (AnnII) and the fibrinolytic activity in NB4 cells and their alterations in the presence of arsenic trioxide (ATO) and daunorubicin (DNR).

METHODSLeukemia cell line NB4 was treated with ATO or DNR for 24 ∼ 72 h. Cell surface expression of AnnII and its mRNA were analysed by flow cytometry and real time PCR, respectively, the fibrinolytic activity by chromogenic assay.

RESULTSCompared with other acute leukemia cell lines, the expression of AnnII on untreated NB4 cells was relatively higher. The AnnII positive cell rates on NB4, HL-60, K562, and A3 cells were (94.5 ± 1.6)%, (40.1 ± 2.1)%, (36.3 ± 1.5)% and (11.8 ± 2.5)%, respectively. The fibrinolytic activity of NB4 cells was the greatest with a A value of 0.68 ± 0.02. The fibrinolytic activity of NB4 cells was obviously decreased by ATO, DNR or monoclonal antibody against AnnII, being decreased by 60.4%, 35.8% and 26.0% of the pretreatment level, respectively. The expressions of AnnII and its mRNA in NB4 cells were decreased dramatically after ATO and DNR treated for 48 h. Annexin II positive cells rate were (55.46 ± 4.72)% and (27.00 ± 6.18)%, respectively.

CONCLUSIONNB4 cells have strong ability to enhance the catalytic efficiency of the t-PA-dependent plasminogen activation and AnnII on the cell membrane contributes to this activity. Its high fibrinolytic activity can be corrected by ATO and DNR through down-regulating AnnII.

Annexin A2 ; Apoptosis ; Daunorubicin ; HL-60 Cells ; Humans ; Leukemia ; metabolism

OBJECTIVETo investigate the effect of thalidomide on Annexin II (AnxA2) gene regulation in multiple myeloma cell line RPMI8226 and human microvascular endothelial cell line HMEC-1 cells in vitro, and explore the potential mechanism of thrombosis induced by thalidomide.

METHODSRPMI8226 and HMEC-1 cells were cultivated in vitro. Real time quantitative PCR (RQ-PCR) was used to detect the influence of thalidomide at different concentration on the expression of AnxA2 mRNA, flow cytometry (FCM) and confocal microscopy were used to detect the cell surface protein level after the samples were stimulated with different concentrations of thalidomide.

RESULTSAnxA2 mRNA level in RPMI8226 cells treated with thalidomide at 12.5 microg/ml, 25.0 microg/ml and 50.0 microg/ml was decreased compared with the control group (0.60+/-0.15, 0.33+/-0.14, 0.42+/-0.16, vs 1.07+/-0.16, respectively, P<0.05) and did so in HMEC-1 cells (0.21+/-0.20, 0.08+/-0.08, 0.17+/-0.16 vs 1.16+/-0.24, respectively, P<0.05). The AnxA2 protein level in RPMI8226 cells treated with above mentioned concentrations of thalidomide was also decreased compared with the control (3.39+/-0.32, 2.82+/-0.28, 3.21+/-0.23 vs 5.53+/-0.32, respectively, P<0.05) and that did so in HMEC-1 cells (0.72+/-0.11, 0.64+/-0.08, 0.67+/-0.08 vs 1.40+/-0.15, respectively, P<0.05).

CONCLUSIONSThalidomide can inhibit the expression of AnxA2 mRNA and protein in RPMI8226 and HMEC-1 cells, which may be one of the mechanisms for the development of thrombosis induced by thalidomide in multiple myeloma patients.

Annexin A2 ; genetics ; metabolism ; Cell Line ; Endothelial Cells ; metabolism ; Endothelium, Vascular ; cytology ; Humans ; Multiple Myeloma ; metabolism ; pathology ; RNA, Messenger ; genetics ; Thalidomide ; pharmacology

OBJECTIVETo develop a monoclonal antibody (mAb) directed to FVIII C2 domain and investigate its effect on FVIII activity.

METHODSFVIII C2 protein was expressed in E. coli and purified. A murine antihuman FVIII C2 domain mAb SZ-132 was developed by standard hybridoma technology and characterized. In coagulation assays, different concentrations of SZ-132 were incubated with freshly collected pooled human plasma and the residual activity of FVIII and activated partial thromboplastin time (APTT) were determined. The effects of SZ-132 on rhFVIII binding to purified human vWF, phosphatidylserine (PS) and platelets were assessed by enzyme linked immunosorbent assays (ELISA).

RESULTSSZ-132 could inhibit FVIII procoagulant activity in a dose-dependent manner within the concentrations of 0-25 microg/ml and the FVIII activity was completely inhibited on above 25 microg/ml. It could also prevent rhFVIII from binding to vWF, PS and platelets.

CONCLUSIONSSZ-132 is a neutralizing mAb against FVIII C2 domain and can inhibit FVIII procoagulant activity by preventing FVIII from binding to vWF and PS.

Animals ; Antibodies, Monoclonal ; biosynthesis ; immunology ; Antibodies, Neutralizing ; biosynthesis ; immunology ; Factor VIII ; immunology ; metabolism ; Humans ; Male ; Mice ; Mice, Inbred BALB C