Korelacija aktivnosti PAI-1 u plazmi i polimorfizma 4G/5G u genu za PAI-1

Abstract

Hemostaza obuhvaća složene, međusobno povezane sustave čija je zadaća održati fluidnost krvi u tekućem stanju u krvožilnom sustavu, ali i omogućiti brzo stvaranje krvnog ugruška nakon ozljede krvne žile. Zgrušavanje i fibrinoliza, dvije ključne komponente hemostaze, moraju biti strogo kontrolirane. Inhibitor aktivatora plazminogena 1 (PAI-1) je jedan od faktora kontrole fibrinolize. Uloga ovog serpina je spriječiti aktivaciju plazminogena u plazmin inhibirajući njegove aktivatore tkivni aktivator plazminogena (tPA) i urokinazu (uPA). Na aktivnost PAI-1 utječe polimorfizam 4G/5G koja se javlja u promotorskoj regiji gena za PAI-1. Homozigoti 4G/4G će imati veću aktivnost PAI-1 od homozigota 5G/5G. Osim toga, na aktivnost PAI-1 djeluju brojni drugi faktori uključujući spol, doba dana, pretilost, inzulin i glukokortikoide. U ovom istraživanju utvrđivali smo ovisnost aktivnosti PAI-1 o prisutnosti polimorfizma 4G/5G u uzorcima plazme 60 ispitanika. Također je ispitana razlika u aktivnosti PAI-1 između muškaraca i žena. Genotip se određivao uređajem za PCR u stvarnom vremenu LightCycler 2.0 (Roche, Švicarska), a aktivnosti funkcionalnim testom na automatskom koagulacijskom analizatoru Behring Coagulation Timer koristeći komplet reagencija Berichrom PAI (Siemens Medical Solutions, Njemačka). Pokazan je trend (p=0.092) veće aktivnosti PAI-1 kod muškaraca, kao što je i očekivano. Nije dokazana statistički značajna razlika u aktivnosti PAI-1 između pojedinih genotipova. Taj neočekivan rezultat objašnjava se malim brojem ispitanika, te ne uzimanjem u obzir ostalih faktora koji utječu na aktivnost PAI-1 kao što su dob, vrijeme uzorkovanja, pretilost, inzulin i glukokortikoidi.Hemostasis consists of complex and interrelated systems whose task is to maintain blood fluidity in the vascular system, while allowing the rapid formation of solid blood clots in the prevention of hemorrhage after a blood vessel injury. The balance between coagulation and fibrinolysis, two key components of hemostasis, has to be strictly controlled. Plasminogen activator inhibitor-1 (PAI-1) is a serpin that prevents the conversion of plasminogen to plasmin by inhibiting its activators - urokinase (uPA) and tissue plasminogen activator (tPA). The PAI-1 gene has a common polymorphism 4G/5G which is located in the promoter region and it affects the activity of PAI-1. People who are homozygotes 4G/4G have a higher plasma PAI-1 activity. Other factors such as age, circadian rhythm, obesity, insulin and glucocorticoids can also influence plasma PAI-1 activity. The aim of this study was to determine the correlation between the 4G/5G polymorphism and the plasma PAI-1 activity in plasma samples of 60 subjects. Additionally, we compared the activities of plasma PAI-1 of female and male subjects. The genotype was determined using the LightCycler 2.0 real-time PCR system (Roche, Switzerland). The activity was determined using the automated hemostasis analyzer Behring Coagulation Timer with the Berichrom PAI test kit (Siemens Medical Solutions, Germany). A trend was found (p=0.092) which confirmed the premise of a higher activity in male patients. A statistically significant difference in the activities between genotypes was not found. This unexpected result can be explained taking into account the small sample size and not considering the other influential factors (age, circadian rhythm, obesity, insulin, glucocorticoids) whilst selecting subject samples