RESUMEN
Previous studies have suggested that microsomal prostaglandin E synthase-1 (mPGES-1) is highly expressed and closely associated with mitogen-activated protein kinase (MAPK) signaling pathways in various types of malignant cells. However, their expression patterns and function with respect to T-cell acute lymphoblastic leukemia (T-ALL) remain largely unknown. The present study investigated whether mPGES-1 served a crucial role in T-ALL and aimed to identify interactions between mPGES-1 and the MAPK signaling pathway in T-ALL. The results indicated that mPGES-1 overexpression in T-ALL jurkat cells was significantly decreased by RNA silencing. Decreasing mPGES-1 on a consistent basis may inhibit cell proliferation, induce apoptosis and arrest the cell cycle in T-ALL jurkat cells. Microarray and western blot analyses revealed that c-Jun N-terminal kinase served a role in the mPGES-1/prostaglandin E2/EP4/MAPK positive feedback loops. In addition, P38 and extracellular signal-regulated kinase 1/2 exhibited negative feedback effects on mPGES-1. In conclusion, the results suggested that cross-talk between mPGES-1 and the MAPK signaling pathway was very complex. Therefore, the combined regulation of mPGES-1 and the MAPK signaling pathway may be developed into a new candidate therapy for T-ALL in the future.
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OBJECTIVE: To investigate the expression and clinical significance of high mobility group box 1(HMGB1) in spleen of adult patients with chronic and refractory immune thrombocytopenia(ITP). METHODS: Twenty chronic and refactory ITP patients received splenectomy were enrolled in ITP group and 20 cases of traumatic spleen rupture were enrolled in control group. The splenectomy efficacy in ITP patients was analyzed retrospectively. The HMGB1 expression in spleen tissue was detected by immunohistochemistry, and the correlation between different expression levels of HMGB1 and splenectomy efficacy were analysed. Meanwhile, the protein expression levels of HMGB1 in peripheral blood serum and mononuclear cells(PBMNC) of 25 patients with chronic and refractory ITP were detected by ELISA and Western blot. RESULTS: The median platelet count before splenectomy was 7.5 (0-20) ×109/L; all the patients showed that the initial response to splenectomy within the first month after operation was 100%, the median time of response was 1 day (1-6 days). The median peak platelet count post splenectomy was 448.5 (161-1272)×109/L. In the median time of 10(3-30) months, the platelets count in 8 patients was reduced to varying degrees. After a median follow-up of 69.5 months (22-195), complete response was found in 12 patients, 4 cases showed response and 4 did not. The HMGB1 expression positive rate in spleen of ITP patients was significantly higher than that in control group (85.0% vs 15.0%)(P<0.001). There were a negative correlation between the HMGB1 expression in ITP and therapeutic outcome after splenectomy (r=-0.791, P<0.01). In addition, HMGB1 expression levels in serum and PBMNC of the patients with chronic refractory ITP were also significantly higher than that in healthy controls (P<0.01). CONCLUSION: The splenectomy has been found to be effective therapeutic method for patients with ITP, the HMGB1 highly express in the spleen of the patients with chronic refractory ITP, but negatively correlats with the therapeutic outcome after splenectomy.
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Púrpura Trombocitopénica Idiopática , Adulto , Proteína HMGB1 , Humanos , Recuento de Plaquetas , Estudios Retrospectivos , Bazo , Esplenectomía , Resultado del TratamientoRESUMEN
OBJECTIVE: To investigate the effects of shRNA targeting mPGES-1 on tumorigenicity of human acute leukemia K562 cells in nude mice in vivo and its mechanisms. METHODS: For experiment 3 groups including KD group(expression of mPGES-1 in K562 cells was down-regulated by shRNA), CON (cells without any treatment) and NC group (cells treated with nonspecific-sequence shRNA) were set-up. Western blot was used to test the expression of ß-catenin and cyclinD1 in cells. Then the cells of 3 groups were implanted into BALB/c nude mice subcutaneously to establish murine xenograft model. The growth state of the mice and the size of the xenograft tumor were recorded. HE staining was used to observe the morphology of xenograft tumor. Expressions of ß-catenin and cyclinD1 in xenograft tumor were detected by immunohistochemical staining. RESULTS: In vitro the expression of ß-catenin and cyclinD1 in KD group were lower than the CON group and NC group (P<0.05). In vivo the tumor volume and weight of KD group were significant smaller than the other two groups (P<0.01). HE staining showed that tissues in the KD group were relatively looser in arrangement with smaller cell nucleus and less cytoplasm. The expression of ß-catenin and cyclinD1 in the KD group were remarkable weak as compared with that in CON group and NC group (P<0.05). CONCLUSION: Down-regulating the expression of mPGES-1 by shRNA may significantly inhibit the tumorigenicity of K562 cells in nude mice in vivo and its mechanism may be related with the inhibition of expression of ß-catenin and cyclinD1.
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Xenoinjertos , Prostaglandina-E Sintasas/metabolismo , ARN Interferente Pequeño , Animales , Línea Celular Tumoral , Proliferación Celular , Regulación hacia Abajo , Humanos , Células K562 , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
OBJECTIVE: To explore the role of Treg cells in the pathogenesis of idiopathic thrombocytopenic purpura (ITP). METHODS: The ITP mouse model was established, the Treg cell ratio in peripheral blood and spleen was detected by flow cytometry, the CD4+ CD25+ T cells were sorted by immunomagnetic beads, the Treg cell associated transcription factors (Foxp3, Smad7, STAT5 and Akt-1) and cytokines (IL-10, TGF-ß) in CD4+ CD25+ T cells were enriched from spleen mononuclear cells, and the mRNA expression of Treg cell was measured by real-time PCR. RESULTS: The ratio of Tregs in peripheral blood and spleen decreased significantly in ITP mouse, as compared with the controls (P<0.01). In addition, the mRNA expression of IL-10, TGF-ß and Foxp3 decreased significantly in spleen CD4+ CD25+ T cells (P<0.05). Expression of Smad 7 mRNA was higher than that of controls. CONCLUSION: The alteration in Treg frequency and function may be responsible for the immune dysfunction in ITP disease. It is also speculated that the lower mRNA expression of Foxp3 and higher mRNA expression of Smad 7 may inhibit the proliferation and differentiation of Treg cells.
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Púrpura Trombocitopénica Idiopática/inmunología , Linfocitos T Reguladores/citología , Animales , Citometría de Flujo , Factores de Transcripción Forkhead/metabolismo , Interleucina-10/metabolismo , Ratones , Púrpura Trombocitopénica Idiopática/patología , ARN Mensajero/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Proteína smad7/metabolismo , Bazo/citología , Factor de Crecimiento Transformador beta/metabolismoRESUMEN
To investigate the effect of a microsomal prostaglandin E synthase-1 (mPGES-1) inhibitor MK886 on cell cycle of the human acute myeloid leukemia HL-60 cells. HL-60 cells were treated with different concentration of MK886 (10, 25, 50 µmol/L) for 24 h. Flow cytometry, Western blot and ELISA were used to measure cell cycle, cyclin D1, mPGES-1, PGE(2), Akt, P-Akt and C-MYC. The results indicated that after treated with MK886, the percentage of HL-60 cells decreased in G(0)/G(1) phase and increased in S phase, and expressions of mPGES-1, cyclin D1, P-Akt and C-MYC and synthesis of PGE(2) decreased significantly. It is concluded that MK886 can arrest HL-60 cells in G(0)/G(1) phase, the mechanism of which is possibly associated to inhibition of mPGES-1 expression, reduction of PGE(2) synthesis, suppression of Akt phosphorylation and C-MYC expression, down-regulation of cyclin D1 expression.
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Ciclo Celular/efectos de los fármacos , Indoles/farmacología , Oxidorreductasas Intramoleculares/antagonistas & inhibidores , Leucemia/patología , Células HL-60 , Humanos , Leucemia/metabolismo , Prostaglandina-E SintasasRESUMEN
This study was aimed to investigate the effect of MK886, a mPGES-1 inhibitor, on apoptosis and drug resistance of leukemia HL-60/A cell line. Expression of mPGES-1 was assayed by QT-PCR and Western blot. The effect of MK886 on HL-60/A cell proliferation was assayed by CCK-8 method, and flow cytometry was used to detect cell apoptosis. The expression of Akt and P-Akt was detected by Western blot. PGE2 was measured by ELISA. Effect of MK886 (10 µmol/L) on the chemotherapeutic sensitivity of HL-60/A cells and expression of mdr-1 mRNA and P170 protein were investigated too. The results indicated the expression of mPGES-1 was higher in HL-60/A cells. MK886 inhibited HL-60/A cell proliferation and induced apoptosis in a time- and concentration-dependent manner. Expression of mPGES-1 and P-Akt and synthesis of PGE2 decreased significantly. MK886 reduced expression of mdr-1 and P170 protein and enhanced the sensitivity of HL-60/A cells to chemotherapeutic drugs. It is concluded that MK886 can inhibit HL-60/A cell proliferation, induce apoptosis and enhance sensitivity to chemotherapeutic drugs, the mechanism of which possibly associates to down-regulation of mPGES-1/PGE2 synthesis, reduction P-Akt expression and decreasing mdr-1 and P170 protein expression.
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Apoptosis/efectos de los fármacos , Resistencia a Antineoplásicos/efectos de los fármacos , Indoles/farmacología , Proliferación Celular/efectos de los fármacos , Regulación Leucémica de la Expresión Génica , Células HL-60 , HumanosRESUMEN
To observe the expression of cyclin D1, hTERT, and telomerase activity in MNC, HL-60, HL-60A and to explore their effects on leukemogenesis and drug-resistance, normal human peripheral blood mononuclear cells, HL-60 cells sensitive to adriamycin and HL-60A cells resistant to adriamycin were investigated. The cell cycle was analyzed by flow cytometry, and the apoptosis was analyzed by Annexin V-FITC(+) PI staining. Expressions of cyclin D1 and hTERT were determined by real-time PCR and Western blot. Telomerase activity was detected by TRAP-ELISA. The results indicated that the percentage of MNC, HL-60 and HL-60A in S phase was (10.21 + 2.11)%, (44.93 + 3.00)%, and (51.38 + 1.10)% respectively; the percentage of apoptosis cells was (16.14 + 2.13)%, (7.53 + 0.92)%, (4.15 + 0.96)% respectively; the expression of mRNA and protein for cyclin D1 and hTERT increased; the telomerase activities of HL-60 and HL-60A were higher (p = 0.000), whereas the difference between HL-60 and HL-60A was no statistically significant (p = 0.232); positive correlation between cyclin D1, hTERT and telomerase activity had been found (p < 0.01). It is concluded that the cells of S phase increased while the apoptotic cells decreased in HL-60 and HL-60A, especially in HL-60A, which may be due to the up-regulation of cyclin D1, hTERT and telomerase activity.
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Ciclina D1/metabolismo , Leucemia/metabolismo , Telomerasa/metabolismo , Ciclo Celular , Células HL-60 , HumanosRESUMEN
This study was aimed to clarify whether valproic acid (VPA) induces apoptosis of leukemia HL-60 cell line and its possible mechanism. The effect of different concentrations and treatment time of VPA on HL-60 cell proliferation was assayed by cytotoxicity test (CCK-8 method) and fluorescence microscopy, and flow cytometry was used to detect cell apoptosis. The expressions of telomerase subunit h-tert mRNA and apoptosis-related protein as well as caspase-3 activity were detected by real time-quantitative PCR, Western blot and ELISA respectively. The results indicated that VPA inhibited proliferation of HL-60 cells and induced cell apoptosis in a dose dependent manner (r = -0.87). The expressions of anti-apoptotic protein BCL-2 and h-tert mRNA were significantly decreased while the pro-apoptotic protein BAX and caspase-3 activity increased after treatment with VPA. The apoptosis rate of HL-60 cell was negatively correlated with expression of h-tert mRNA. It is concluded that VPA can inhibit leukemia HL-60 cell proliferation and induce apoptosis. The VPA displays anti-leukemia activity possibly through reducing h-tert mRNA and BCL-2 protein expression, increasing BAX expression and activity of caspase-3.
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Apoptosis/efectos de los fármacos , Telomerasa/metabolismo , Ácido Valproico/farmacología , Caspasa 3/metabolismo , Células HL-60 , Humanos , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Proteína X Asociada a bcl-2/metabolismoRESUMEN
OBJECTIVE: To investigate the effect of 3'-meisoindigo on the proliferation and the biological function of the splenocyte and thymocyte of mouse, which were 8 weeks old masculinity BALB/c, C57BL/6 and F1 hybridization mouse. METHODS: Cells of thymus and spleen were harvested and prepared as the unicell suspension, then treated with 5, 10, 15, 20, 25 micromol/L 3'-meisoindigo. The cell proliferation was by MTT method, concentration of IL-12 was dectected by ELISA method, the mRNA levels of Bcl-2 and CDK2 were decected by RT-PCR. The cell cycle, apoptosis ratio, death ratio and intracellular ROS concentration were detected by FCM method. The protein level of Bcl-2, CDK2 and Bax were detected by immumofluorescence method. RESULTS: 15, 20, 25 micromol/L 3'-meisoindigo can inhibit the proliferation of thymocyte and splenocyte (P < 0.05). It had dose-dependent and time-dependent manner. 3'-meisoindigo inhibit the secretion of IL-12, even at 5 micromol/L concentration. 15 micromol/L 3'-meisoindigo decrease the mRNA level of Bcl-2 and CDK2, induced apoptosis and G2 arrestting of the thymocyte and splenocyte. (P < 0.05). The intracellular ROS level increased after treated by 3'-meisoindigo at 15 micromol/L for 24 h (P < 0.05). There were no difference among three germ line mouse. CONCLUSION: Above 15 micromol/L, 3'-meisoindigo can inhibit the proliferation and externalization function of thymocyte and splenocyte from different germ line mouse, meanwhile the mRNA and protein level of Bcl-2 and CDK2 decrease, the Bax protein expressed increased, the intracellular ROS level increase too.
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Adyuvantes Inmunológicos/farmacología , Extractos Vegetales/farmacología , Bazo/citología , Timo/citología , Animales , Apoptosis/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Quinasa 2 Dependiente de la Ciclina/genética , Quinasa 2 Dependiente de la Ciclina/metabolismo , Indoles/administración & dosificación , Indoles/farmacología , Interleucina-12/metabolismo , Isatis/química , Linfocitos/efectos de los fármacos , Linfocitos/metabolismo , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Extractos Vegetales/administración & dosificación , Polygonum/química , Proteínas Proto-Oncogénicas c-bcl-2/genética , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Especificidad de la Especie , Bazo/inmunología , Timo/inmunologíaRESUMEN
OBJECTIVE: To investigate the effect of valproic acid on the expression of P27(Kip1) and P170 and drug resistance of leukemia HL60/HT cell line and explore its possible mechanisms. METHODS: HL-60/HT cells were derived from HL-60 cells induced by harringtonine (HT) in gradient concentrations. The inhibitory effect of valproic acid on the proliferation of HL-60 and HL-60/HT cells was evaluated by MTT assay, and the P27(Kip1) expression, P170 expression and cell cycle of the cells were analyzed with flow cytometry. RESULTS: The multidrug-resistant HL-60/HT was acquired, which showed a stable drug-resistant index with increased IC(50) of HT, VCR, DNR and Ara-c by 9.30, 5.20, 4.91 and 3.65 folds, respectively, as compared with those of HL60 cells. The expression of P27(Kip1) in HL-60/HT cells was significantly lower but P170 expression significantly higher than that of HL-60 cells and normal mononuclear cells (P<0.05). The expressions of P27(Kip1) and P170 showed no significant difference between normal mononuclear cells and HL-60 cells. The growth inhibition rate of VPA combined with Ara-C was significantly higher than that of valproic acid or Ara-C alone in HL-60/HT cells and HL-60 cells (q=1.37 and 1.51, respectively). HL-60/HT and HL-60 cells cultured in the presence of VPA resulted in a significant increase in the expression of P27(Kip1) and the G(1)-phase cells (P<0.05), but the expression of P170 underwent no significant changes (P>0.05). CONCLUSION: HL-60/HT cells have lower P27(Kip1) expression compared with HL-60 cells. Valproic acid can inhibit the growth of HL-60/HT cells and enhance their Ara-C sensitivity possibly by increasing P27(Kip1) expression and causing cell cycle arrest in G(1) phase.
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Antineoplásicos/farmacología , Inhibidor p27 de las Quinasas Dependientes de la Ciclina/metabolismo , Resistencia a Antineoplásicos/efectos de los fármacos , Glicoproteínas/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Ácido Valproico/farmacología , Subfamilia B de Transportador de Casetes de Unión a ATP , Inhibidor p27 de las Quinasas Dependientes de la Ciclina/genética , Citarabina/farmacología , Resistencia a Múltiples Medicamentos/efectos de los fármacos , Glicoproteínas/genética , Células HL-60 , Humanos , Péptidos y Proteínas de Señalización Intracelular/genéticaRESUMEN
OBJECTIVE: To explore the in vitro anti-platelet effects of Ginsenoside -2A,a purified extract from Panax notoginseng. METHODS: Platelet rich plasma (PRP) was prepared routinely from venous blood samples of patients with essential hypertension and normal persons. PRP was incubated with different concentrations of Nifedipine, Ginsenoside-2A ,and SK&F96365. Maximal platelet aggregation rate[ PAG (M) ] induced by 2 micromol/L ADP was taken as the observed index. Five-minute PAG( M) was determined for 5 consecutive times. RESULTS: (1) PAG (M) in essential hypertension group was 0. 89 +/- 0. 06, which was higher than that in the normal group (0. 68 +/-0. 07 ) with significant difference (P <0.01). (2)Nifedipine of two concentrations (10 p.mol/L,20 pVmol/L) had no effect on PAG(M) in either essential hypertension group or normal group(P >0. 05). (3)Different concentrations of SK&F96365 (2.5 micromol/L,5 micromol/L,10 micromol/L and 20 micromol/L) could inhibit the PAG(M) in essential hypertension group; (4) Differen concentrations of Ginsenoside -2A (2. 5 micromol/L, 5 micromol/L, 10 micromol/L and 20 micromol/L) could inhibit PAG ( M) in essential hypertension group; three concentrations of Ginsenoside -2A (5 micromol/L, 10 micromol/L, 20 micromol/L) could inhibit the PAG(M) in the normal group (all P <0.05). CONCLUSION: Platelet aggregating function in essential hypertension patients was obviously higher than that in the normal persons and platelets was in the high reactive status. Nifedipine had no inhibitive effect on platelet aggregation. SK&F96365 could inhibit the platelet aggregation. Ginsenoside-2A could inhibit platelet aggregation, and had the definite anti-platelet action.
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Medicamentos Herbarios Chinos/farmacología , Ginsenósidos/farmacología , Inhibidores de Agregación Plaquetaria/farmacología , Medicamentos Herbarios Chinos/administración & dosificación , Ginsenósidos/administración & dosificación , Humanos , Imidazoles/administración & dosificación , Imidazoles/farmacología , Nifedipino/administración & dosificación , Nifedipino/farmacología , Inhibidores de Agregación Plaquetaria/administración & dosificaciónAsunto(s)
Ácido 4,4'-Diisotiocianostilbeno-2,2'-Disulfónico/farmacología , Plaquetas/metabolismo , Calcio/metabolismo , Canales de Cloruro/antagonistas & inhibidores , Citosol/metabolismo , Ácido Niflúmico/farmacología , Oligopéptidos/farmacología , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria/antagonistas & inhibidores , Adolescente , Adulto , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Masculino , Agregación Plaquetaria/efectos de los fármacosRESUMEN
OBJECTIVE: To explore the effects of chloride channels on the regulation of platelet cytoplasmic free calcium concentration ([Ca2+]i) and platelet aggregation (PAG). METHODS: Freshly separated platelets were activated by thrombin. Chloride channel blockers DIDS or NFA and calcium channel blockers SK&F96365 or nifedipine were added to study the effects on platelet [Ca2+]i and PAG by a single reagent or the combination of reagents and find out the interactions among DIDS, NFA, SK&F96365 and nifedipine. RESULTS: Both DIDS and NFA could inhibit the thrombin (1 U/ml) induced PAG in a dose-dependent manner, whereas had little effect on resting [Ca2+]i. As compared with the control group, DIDS, SK&F96365 and Nifedipine could significantly reduce the PAG, Ca2+ release and Ca2+ influx in thrombin activated platelet (P < 0.05). The combination of DIDS and SK&F96365 had greater effects in reducing the PAG, Ca2+ release and Ca2+ influx than either reagent alone (P < 0.05). The combination of DIDS and nifedipine also had greater effect than each alone in reducing Ca2+ release (P < 0.05). The combination of NFA and SK&F96365 weakened each other's effect on Ca2+ release (P < 0.05), while NFA and nifedipine weakened each other's effects on PAG, Ca2+ release and Ca2+ influx in thrombin activated platelet (P < 0.05). CONCLUSION: DIDS and NFA have no effect on the resting [Ca2+]i and the leak calcium influx of platelet. DIDS can inhibit the Ca2+ release, Ca2+ influx and PAG of platelet induced by thrombin, while NFA can only inhibit the Ca2+ release. The chloride channel and calcium channel blockers have interactions in affecting resting [Ca2+]i and PAG of platelet. The opening of chloride channel can influence the cellular calcium movement of platelet.
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Ácido 4,4'-Diisotiocianostilbeno-2,2'-Disulfónico/farmacología , Plaquetas/efectos de los fármacos , Calcio/metabolismo , Ácido Niflúmico/farmacología , Agregación Plaquetaria/efectos de los fármacos , Adulto , Plaquetas/citología , Plaquetas/metabolismo , Bloqueadores de los Canales de Calcio/farmacología , Células Cultivadas , Canales de Cloruro/antagonistas & inhibidores , Canales de Cloruro/fisiología , Citoplasma/efectos de los fármacos , Citoplasma/metabolismo , Interacciones Farmacológicas , Humanos , Imidazoles/farmacología , Nifedipino/farmacología , Trombina/farmacologíaRESUMEN
OBJECTIVE: To investigate the platelet activity and function in pregnancy induced hypertension (PIH) and gestational diabetes mellitus (GDM). METHODS: Twenty-one patients with GDM and 23 patients with PIH in third-trimester were included. Twenty normal pregnant women in third-trimester served as controls. Platelet count (PC), mean platelet volume (MPV) were determined on Cell-DYN 1600 and the expression of CD62P was analyzed on FACSC alibur. RESULTS: (1) PC was (181 +/- 56) x 10(9)/L in PIH, (206 +/- 60) x 10(9)/L in GDM and (229 +/- 56) x 10(9)/L in controls, respectively. PC in PIH was lower than that of controls (P < 0.01), but there was no significant difference between GDM and controls. (2) MPV was (11.2 +/- 2.0) fl in PIH, significantly higher than that of controls (8.7 +/- 1.6) fl (P < 0.001). In GDM, MPV was (9.5 +/- 1.6) fl, without significant difference compared with that of controls. (3) The expression of CD62P increased significantly in PIH compared with controls [CD62P: (42 +/- 13)% vs (26 +/- 7)%, P < 0.001; CD62P(I): 109 +/- 39 vs 75 +/- 13, P < 0.01]. In GDM, the expression of CD62P also increased significantly compared with the normal pregnancy [CD62P(%): (42 +/- 14)% vs (26 +/- 7), P < 0.001; CD62P(I): 100 +/- 42 vs 75 +/- 13, P < 0.05]. (4) All parameters had no significant difference between PIH and GDM. CONCLUSION: Platelet activity is enhanced in PIH and GDM. It may play an important role in the pathogenesis and development of the two diseases.
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Plaquetas/fisiología , Diabetes Gestacional/sangre , Hipertensión Inducida en el Embarazo/sangre , Adulto , Femenino , Citometría de Flujo , Humanos , Activación Plaquetaria , Recuento de Plaquetas , Glicoproteínas de Membrana Plaquetaria/biosíntesis , EmbarazoRESUMEN
OBJECTIVE: To 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. METHODS: Thirty 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. RESULTS: The 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. CONCLUSIONS: The 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.
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Plaquetas/metabolismo , Óxido Nítrico Sintasa/sangre , Óxido Nítrico/sangre , Pravastatina/farmacología , Animales , Aterosclerosis/sangre , Aterosclerosis/patología , Modelos Animales de Enfermedad , Masculino , Óxido Nítrico/genética , Óxido Nítrico Sintasa/genética , ARN Mensajero/genética , ConejosRESUMEN
OBJECTIVE: To explore the effects of 2A-1-1 (purified component from Panax notoginsengs saponins) on the aggregation of and Ca2+ influx into human platelets. METHODS: The 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. RESULTS: Nifedipine (< 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. CONCLUSIONS: 2A-1-1 can inhibit platelets aggregation, block the ROC (Receptor-dependent Ca2+ channels) and inhibit Ca2+ influx of human platelets.