RESUMEN
BACKGROUND: It has been suggested that genetic factors may be substantially linked to allergy disorders. OBJECTIVE: This study aims to investigate the relationship between the serum specific Immunoglobulin E (sIgE), blood eosinophil, and the polymorphisms of glycoprotein Ib alpha gene (GP1BA) rs6065, platelet endothelial aggregation receptor 1 gene (PEAR1) rs12041331, and plasminogen activator inhibitor 1 gene (PAI-1) rs1799762. METHODS: From the Peking Union Medical College Hospital, this study enrolled 60 healthy participants and 283 participants with allergic diseases. TaqMan-minor groove binder (MGB) quantitative polymerase chain reaction (qPCR) was used to examine the gene polymorphisms in each group. RESULTS: The TaqMan-MGB qPCR results were completely consistent with the DNA sequencing results, according to other studies in this medical center (Kappa =1, p <0.001). The GP1BA rs6065, PEAR1 rs12041331, and PAI-1 rs1799762 polymorphisms did not show different distribution between allergy patients and healthy individuals. Concerning allergy patients, the CT (n=33) genotype of GP1BA rs6065 had higher blood eosinophil level than the CC (n=250) genotype (0.59, IQR 0.32-0.72 vs 0.31, IQR 0.15-0.61, *109/L, p =0.005). The serum sIgE of AA (n=46) genotype of PEAR1 rs12041331 was lower (median 3.7, interquartile quartiles (IQR) 0.2-16.8, kU/L) than the GA (n=136) and GG (n=101) genotypes (GA median 16.3, IQR 3.1-46.3, kU/L, p = 0.002; GG median 12.9, IQR 3.0-46.9, kU/L, p =0.003). The GA genotypes of PEAR1 rs12041331were with higher blood eosinophil levels (median 0.42, IQR 0.17-0.74 *109/L) than the AA genotype (median 0.25, IQR 0.15-0.41*109/L, p =0.012). The sIgE of the 5G5G (n=44) genotype of PAI-1 rs1799762 was lower (median 5.0, IQR 0.1-22.8, kU/L) than the 4G5G (n=144) (median 17.3, IQR 3.7-46.0, kU/L, p = 0.012). CONCLUSION: The GP1BA rs6065, PEAR1 rs12041331, and PAI-1 rs1799762 polymorphisms may be associated with the genetic susceptibility of serum sIgE or blood eosinophil in Chinese allergic disease patients.
Asunto(s)
Pueblo Asiatico , Eosinófilos , Predisposición Genética a la Enfermedad , Hipersensibilidad , Inmunoglobulina E , Inhibidor 1 de Activador Plasminogénico , Complejo GPIb-IX de Glicoproteína Plaquetaria , Polimorfismo de Nucleótido Simple , Receptores de Superficie Celular , Humanos , Masculino , Femenino , Inmunoglobulina E/sangre , Adulto , Inhibidor 1 de Activador Plasminogénico/genética , Inhibidor 1 de Activador Plasminogénico/sangre , Receptores de Superficie Celular/genética , Receptores de Superficie Celular/sangre , Hipersensibilidad/genética , Hipersensibilidad/sangre , Pueblo Asiatico/genética , Persona de Mediana Edad , Complejo GPIb-IX de Glicoproteína Plaquetaria/genética , China/epidemiología , Estudios de Casos y Controles , Adulto Joven , Estudios de Asociación Genética , Adolescente , Pueblos del Este de AsiaRESUMEN
Background: Several assays are now available to evaluate platelet-dependent von Willebrand factor (VWF) activity. Objective: To report the results obtained using 4 different assays in patients with von Willebrand disease (VWD) carrying variants mainly in the A1 domain, which is critical for VWF binding to glycoprotein Ib (GPIb) and ristocetin. Methods: We evaluated 4 different assays, 2 gain-of-function mutant GPIb binding (VWF:GPIbM) and 2 ristocetin cofactor (VWF:RCo) assays, in 76 patients with type 2 VWD. Patients and healthy controls were tested using VWF:GPIbM enzyme-linked immunosorbent assay (ELISA), VWF:GPIbM automated, VWF:RCo aggregometric, and VWF:RCo automated assays. Results: There was a good correlation (Pearson's r>0.82) and agreement (Bland-Altman plots assessment) between the 4 assays, although several outliers existed among the type 2B without high-molecular-weight multimers (HMWM). The VWF activity/VWF:antigen ratios, calculated for each assay, were used to establish the percentage of a correct diagnosis of type 2 (ratio<0.60) in these patients: VWF:RCo aggregometric, 2A(100%), 2M(78%), 2M/2A(100%), 2B(68%); VWF:RCo automated, 2A(88%), 2M(89%), 2M/2A(100%), 2B(63%); VWF:GPIbM ELISA, 2A(96%), 2M(67%), 2M/2A(67%), 2B(0%); VWF:GPIbM automated, 2A(73%), 2M(44%), 2M/2A(75%), 2B(84%). In type 2B patients with HMWM, all assays gave a ratio ≥0.60. Conclusion: The VWF:GPIbM-automated assay is the most effective to diagnose as type 2 the 2B variants, whereas the VWF:RCo assays are the most effective in detecting 2M and 2M/2A variants. The VWF:GPIbM ELISA greatly overestimates the activity of the type 2B patients lacking HMWM. In this study, the use of a VWF activity/VWF:antigen ratio cut-off of 0.70 halved the number of misdiagnosed patients.
RESUMEN
BACKGROUND: Atherosclerotic plaque rupture and subsequent thrombosis underpin thrombotic syndromes. Under inflammatory conditions in the unstable plaque, perturbed endothelial cells secrete von Willebrand Factor (VWF) which, via its interaction with GpIbα, enables platelet rolling across and adherence to the damaged endothelium. Following plaque rupture, VWF and platelets are exposed to subendothelial collagen, which supports stable platelet adhesion, activation, and aggregation. Plaque-derived matrix metalloproteinase (MMP)-13 is also released into the surrounding lumen where it may interact with VWF, collagen, and platelets. OBJECTIVES: We sought to discover whether MMP-13 can cleave VWF and whether this might regulate its interaction with both collagen and platelets. METHODS: We have used platelet adhesion assays and whole blood flow experiments to assess the effects of VWF cleavage by MMP-13 on platelet adhesion and thrombus formation. RESULTS: Unlike the shear-dependent cleavage of VWF by a disintegrin and metalloprotease with thrombospondin motif member 13 (ADAMTS13), MMP-13 is able to cleave VWF under static conditions. Following cleavage by MMP-13, immobilized VWF cannot bind to collagen but interacts more strongly with platelets, supporting slower platelet rolling in whole blood under shear. Compared with intact VWF, the interaction of cleaved VWF with platelets results in greater GpIbα upregulation and P-selectin expression, and the thrombi formed on cleaved VWF-collagen co-coatings are larger and more contractile than platelet aggregates on intact VWF-collagen co-coatings or on collagen alone. CONCLUSIONS: Our data suggest a VWF-mediated role for MMP-13 in the recruitment of platelets to the site of vascular injury and may provide new insights into the association of MMP-13 in atherothrombotic and stroke pathologies.
Asunto(s)
Plaquetas , Colágeno , Metaloproteinasa 13 de la Matriz , Factor de von Willebrand , Células Endoteliales , Humanos , Adhesividad PlaquetariaRESUMEN
BACKGROUND: Disruption of protein folding or inter-subunit interactions in the platelet glycoprotein (GP)Ib-IX complex leads to its abnormally low expression in the plasma membrane, the hallmark of Bernard-Soulier syndrome (BSS). OBJECTIVE: To discover the molecular mechanism by which GPIbα in the absence of GPIbß and GPIX subunits is targeted for rapid degradation. METHOD: The expression of GPIbα mutants with deletion or replacement of various domains were measured in transiently transfected Chinese hamster ovary cells. RESULTS: We report evidence to suggest that induction of the unfolded protein response by the unaccompanied mechanosensory domain (MSD) is a major factor for intracellular degradation and low expression of GPIbα. Removal of the MSD produced the first GPIbα variant that, even in the absence of GPIbß and GPIX, expressed at a level comparable to that of wild-type GPIbα in the GPIb-IX complex, while retaining its native ligand-binding activity. CONCLUSION: Our finding has important implications on the molecular pathogenesis of BSS and the function of the GPIb-IX complex.