| 1. |
- van Rooijen, Marianne, et al.
(författare)
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APC resistance during the normal menstrual cycle
- 2007
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Ingår i: Thrombosis and Haemostasis. - 0340-6245 .- 2567-689X. ; 98:6, s. 1246-1251
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Tidskriftsartikel (refereegranskat)abstract
- Increased serum levels of endogenous as well as exogenous estrogen are regarded to be responsible for acquired activated protein C (APC) resistance. It was the objective of this study to evaluate whether the physiological increase in serum estradiol concentration during the normal menstrual cycle affects the individual's sensitivity to APC. Seventy-two women with normal menstrual cycles were included in the study. Blood samples for analysis of estradiol (E2), progesterone (P4) and APC resistance were drawn at two time points of the menstrual cycle (day 3-5 and day 22-25). Two methods of measuringAPC resistance were used: the activated partial thromboplastin time (aPTT)-based assay and the endogenous thrombin potential (ETP)-basedAPC resistance test. Independent of the method used, no changes in APC resistance were found, even though the E2 concentration increased significantly between the two menstrual phases. No correlations between E2 levels andAPC resistance, P4 levels and APC resistance or changes in E2 concentrations and changes in APC resistance were detected. Ten women were carriers of the factor V-Leiden mutation, Their baseline APC resistance was increased, but their response to elevated E2 during the menstrual cycle did not differ from that of non-carriers. In conclusion, our observations suggest that physiological differences in serum levels of estradiol and progesterone between the early follicular and the luteal phase in a normal menstrual cycle do not have any significant impact on the individual's sensitivity to APC.
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| 2. |
- Zhu, Chaoyong, et al.
(författare)
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Allele-specific MMP-3 transcription under in vivo conditions
- 2006
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Ingår i: Biochemical and Biophysical Research Communications - BBRC. - : Elsevier BV. - 0006-291X .- 1090-2104. ; 348:3, s. 1150-1156
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Tidskriftsartikel (refereegranskat)abstract
- A common matrix metalloproteinases-3 (MMP-3) -1612 5A/6A promoter polymorphism is associated with risk for cardiovascular disease, rheumatoid arthritis, and other diseases. Here we used the haplotype chromatin immunoprecipitation method to study allele-specific MMP-3 expression under in vivo conditions in heterozygous THP-1 cells. Pyrosequencing was used to analyse the ratio of 5A-allele to 6A-allele after chromatin immunoprecipitation using an antibody against phosphorylated active RNA polymerase II. There was no allele-specific difference in transcriptional activity during basal conditions, i.e., in unstimulated monocytic THP-1 cells. However, after stimulation of MMP-3 expression by monocyte differentiation or incubation with IL-1 beta, the haplotype containing the 5A-allete was associated with higher transcriptional activity compared with the 6A-containing haplotype. Electromobility shift assay demonstrated increased binding of nuclear proteins to the 5A-allele after monocyte differentiation. In conclusion, the common MMP-3 5A/6A promoter polymorphism appears to be functional only during specific environmental conditions involving inflammation.
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