scholarly journals Regulatory polymorphism in vitamin K epoxide reductase complex subunit 1 (VKORC1) affects gene expression and warfarin dose requirement

Blood ◽  
2008 ◽  
Vol 112 (4) ◽  
pp. 1013-1021 ◽  
Author(s):  
Danxin Wang ◽  
Huizi Chen ◽  
Kathryn M. Momary ◽  
Larisa H. Cavallari ◽  
Julie A. Johnson ◽  
...  

Abstract Warfarin dose requirements have been associated with 2 main haplotypes in VKORC1, but the responsible polymorphisms remain unknown. To search for regulatory polymorphisms, we measured allelic mRNA expression of VKORC1 in human liver, heart, and B lymphocytes. The observed 2-fold allelic mRNA expression imbalance narrowed possible candidate SNPs to −1639G>A and 1173C<T. This genotype effect was observed selectively in the liver but not in heart or lymphocytes. In vitro expression of VKORC1 gene constructs, including coding and promoter regions, failed to reveal any genotype effect on transcription and mRNA processing. Chromatin immunoprecipitation with antibodies against acetyl-histone3 and K4-trimethyl-histone3 revealed preferential association of the promoter −1639 G allele with active chromatin, consistent with enhanced mRNA expression. The minor −1639 A allele generates a suppressor E-box binding site, apparently regulating gene expression by a mechanism undetectable with reporter gene assays. A clinical association study demonstrated that promoter SNP −1639G>A, and the tightly linked intron1 SNP 1173C>T, predict warfarin dose more accurately than intron 2 SNP 1542G>C in blacks. Increased warfarin dose requirement in blacks was accounted for by lower frequency of the −1639 A allele. Therefore, −1639G>A is a suitable biomarker for warfarin dosing across ethnic populations.

Blood ◽  
2012 ◽  
Vol 119 (3) ◽  
pp. 868-873 ◽  
Author(s):  
Tina T. Biss ◽  
Peter J. Avery ◽  
Leonardo R. Brandão ◽  
Elizabeth A. Chalmers ◽  
Michael D. Williams ◽  
...  

Abstract Although genetic and environmental factors explain approximately half of the interindividual variability in warfarin dose requirement in adults, there is limited information available in children. In a cross-sectional study of anticoagulated children from 5 tertiary care centers, 120 children with a stable warfarin dose were genotyped for VKORC1 (−1639G > A; rs9923231), CYP2C9 (*2 and *3 alleles; rs1799853 and rs1057910), and CYP4F2 (V433M; rs2108622) polymorphisms. Clinical and demographic features were recorded. Multiple regression analysis of the data showed that, although CYP4F2 made no contribution to the dose model, 72.4% of the variability in warfarin dose requirement is attributed to by patient height, genetic polymorphisms in VKORC1 and CYP2C9, and indication for warfarin. The recently published International Warfarin Pharmacogenetics Consortium pharmacogenetic-based warfarin dosing algorithm (based on data derived from anticoagulated adults) consistently overestimated warfarin dose for our cohort of children. A similar proportion of the interindividual variability in warfarin dose is explained by genetic factors in children compared with adult patients, although height is a greater predictor in children. A pharmacogenomic approach to warfarin dosing has the potential to improve the efficacy and safety of warfarin therapy in children. However, algorithms should be derived from data in children if their potential benefit is to be realized.


2021 ◽  
Author(s):  
Jozsef Bodis ◽  
Endre Sulyok ◽  
Akos Varnagy ◽  
Viktória Prémusz ◽  
Krisztina Godony ◽  
...  

Abstract BackgroundThis observational clinical study evaluated the expression levels and predictive values of some apoptosis-related genes in granulosa cells (GCs) and follicular fluid (FF) of women undergoing in vitro fertilization (IVF).Methods GCs and FF were obtained at oocyte retrieval from 31 consecutive patients with heterogeneous infertility diagnosis (age: 34.3±5.8 years, body mass index: 24.02±3.12 kg/m2, duration of infertility: 4.2±2.1 years). mRNA expression of pro-apoptotic (BAX, CASP3, CASP8) and anti-apoptotic (BCL2, AMH, AMHR, FSHR, LHR, CYP19A1) factors was determined by quantitative RT-PCR using ROCHE LightCycler 480. Results No significant difference in GC or FF mRNA expression of pro- and anti-apoptotic factors could be demonstrated between IVF patients with (9 patients) or without (22 patients) clinical pregnancy. Each transcript investigated was detected in FF, but their levels were markedly reduced and independent of those in GCs. The number of retrieved oocytes was positively associated with GC AMHR (r=0.393, p=0.029), but the day of embryo transfer was negatively associated with GC LHR (r=-0.414, p=0.020) and GC FSHR transcripts (r=-0.535, p=0.002). When pregnancy positive group was analysed separately the impact of apoptosis- related gene expressions on some selected measures of IVF success could be observed. Strong positive relationship was found between gene expression levels of pro- and anti-apoptotic factors in GCs.ConclusionOur study provides only marginal evidences for the apoptosis dependence of IVF outcome and suggests that the apoptosis process induces adaptive increases of the anti-apoptotic gene expression to attenuate apoptosis and to protect cell survival.


2020 ◽  
pp. postgradmedj-2019-137197
Author(s):  
Maryam Hosseindokht ◽  
Hamed Zare ◽  
Rasoul Salehi ◽  
Leyla Pourgholi ◽  
Shayan Ziaee ◽  
...  

BackgroundThe optimal dose of anticoagulant warfarin varies among patients to achieve the target international normalised ratio. Although genetic variations related to warfarin pharmacokinetics and vitamin K cycle are important factors associated with warfarin dose requirements, these variations do not completely explain the large interindividual variability observed in the most populations, suggesting that additional factors may contribute to this variability. microRNAs have recently been introduced as regulators of drug function genes, and therefore, may be involved in drug responses. In this study, we aimed to evaluate the possible association between variants in the seed region of microRNAs, which target the genes involved in the action of warfarin and warfarin dose requirement.Methods526 samples were collected from Iranian patients. Four selected polymorphisms in the seed region of microRNAs (rs2910164, rs66683138, rs12416605 and rs35770269 in miR-146a, miR-3622a, miR-938 and miR-449c, respectively) were genotyped by PCR-restriction fragment length polymorphism method.Resultsrs2910164 C/G in the seed region of miR-146a was associated with warfarin dose requirement (p<0.001); the patients with GG genotype had the higher mean dose of warfarin (40.6 mg/week, compared with 33.9 and 31.8 mg/week for GC and CC genotypes, respectively). The association of other polymorphisms with warfarin dose requirement was not statistically significant.Conclusionrs2910164 C/G in the seed region of miR-146a is associated with warfarin maintenance dose, likely by disrupting interaction between miR-146a and ATP-binding cassette subfamily B member 1 gene, ABCB1. Therefore, this polymorphism may possibly be a potential factor for assessment of warfarin dose requirements.


2000 ◽  
Vol 279 (6) ◽  
pp. E1398-E1405 ◽  
Author(s):  
Valérie Serazin-Leroy ◽  
Mireille Morot ◽  
Philippe de Mazancourt ◽  
Yves Giudicelli

Adipose tissue is an important source of angiotensinogen (ATG), and hypertension is commonly associated with android obesity. Therefore, we tested the hypothesis that androgens may control ATG gene expression and secretion in rat fat cells. In intact male rats, ATG mRNA expression (Northern blot and co-reverse transcription-polymerase chain reaction analysis) and protein secretion were significantly higher in deep intra-abdominal (perirenal and epididymal) than in subcutaneous adipocytes. After castration, ATG mRNA was reduced almost 50% in the three fat deposits, with parallel changes in ATG protein secretion. Conversely, testosterone treatment fully restored the ATG mRNA decrease after castration, whatever the anatomical origin of the adipocytes. Finally, a 24-h in vitro exposure of perirenal fat cells or differentiated preadipocytes from castrated rats to testosterone or dihydrotestosterone (10 nM free hormone concentration) increased ATG mRNA expression by 50–100%, an effect that was prevented by the anti-androgen cyproterone acetate. These data, demonstrating both in vivo and in vitro androgen induction of ATG mRNA expression in rat adipocytes, add further weight to the hypothesis of a link between adipose tissue ATG production, androgens, and android obesity-related hypertension.


2020 ◽  
Author(s):  
Cansu Selcan Akdeniz ◽  
Mehtap Cevik ◽  
Ismail Polat Canbolat ◽  
Selen Yurdakul ◽  
Penbe Cagatay ◽  
...  

Aim: Our aim was to examine the effect of CYP2C9 and VKORC1 polymorphisms on warfarin dose requirements in Turkish patients. Materials & methods: 24 warfarin prescribed patients were included and analyzed for eight VKORC1 and 6 CYP2C9 polymorphisms in the study. Results: Patients with CYP2C9 *1/*1 and VKORC1 -1639 GG and GA genotypes required higher warfarin doses in comparison to wild type VKORC1 genotype. Patients with CYP2C9 *1/*3 and VKORC1 -1639 GG genotypes simultaneously, required the lowest dose of warfarin (4.64 mg/day). Patients with CYP2C9 *1/*1 and VKORC1 9041 AA genotype were found to require higher warfarin doses. Conclusion: Our results provide additional evidence to support the hypothesis that CYP2C9 *2, *3, VKORC1 9041 G > A polymorphisms explain considerable proportion of inter-individual variability in warfarin dose requirement.


2016 ◽  
Vol 28 (2) ◽  
pp. 137
Author(s):  
Y. Liu ◽  
A. Lucas-Hahn ◽  
B. Petersen ◽  
R. Li ◽  
D. Hermann ◽  
...  

Conventional “Dolly”-based cloned (CNT) embryos maintain zona pellucida and can be transferred early in development. Handmade cloned (HMC) embryos are zona free and are cultured to later stages for transfer. We have shown differences between HMC and CNT embryos (Rep. Fert. Dev. 26, 123), and both in vitro culture and cloning method (NT) are associated with alterations in histone acetylation. More studies are needed to clarify whether CNT and HMC embryos differ in epigenetic profiles due to NT method or culture condition. Here we investigated histone acetylation profile of NT embryos produced by CNT or HMC with or without 5 to 6 days in vitro culture, emphasising quality and gene expression in resulting embryos. Both NT methods were performed on Day 0 (D0) with same oocyte batch, donor cells, and culture medium (CNT in group, HMC in well of well). On D0, 5, and 6 after CNT (Clon. Stem Cells 10, 355) or HMC (Zygote 20, 61), all developed embryos of all morphological qualities were collected for immunostaining of H3K18ac, and on D0 and 6 for mRNA expression of the genes KAT2A/2B, EP300, HDAC1/2, DNMT1o/s, and GAPDH. Embryo quality was evaluated normal (clear inner cell mass, high cell number, no fragments) or bad (no clear inner cell mass, low cell number, fragments). Cell numbers per blastocyst were counted on D5 and 6. Differences in cell number and H3K18ac level between different groups and days were analysed by ANOVA; gene expression data were analysed by GLM (SAS version 9.3, SAS Institute Inc., Cary, NC, USA). Embryo development rates of both NT methods were reported previously (Rep. Fert. Dev. 26, 123). On D5 and 6, all HMC embryos were evaluated as normal, but the CNT group contained both normal and bad embryos. Regarding cell numbers (Table 1), on D5 there was no difference between normal CNT and HMC embryos, but numbers were lower in CNT bad embryos. On D6 the blastocyst cell number was lower in both normal and bad CNT embryos compared with HMC. Regarding H3K18ac levels (Table 1), no differences were found on D5 between normal CNT and HMC embryos, but on D6 both CNT normal and bad embryos had higher H3K18ac level compared with HMC. On D0, no difference was found in mRNA expression of all 8 genes. On D6, KAT2A expression was slight increased (1.8-fold) in CNT compared with HMC embryos (P < 0.05). In conclusion, no differences were found between CNT and HMC embryos after completed NT procedure (D0) or after 5 days in vitro culture. However, differences in quality (cell number and H3K18ac) and gene expression between the 2 NT methods were observed when blastocyst expansion was initiated (D6). Thus, the 2 NT methods seem to produce embryos of similar quality, which is maintained over 5 days in vitro culture, but thereafter gene expression and histone acetylation are more active in CNT embryos. Table 1.Cell number and H3K18ac level1


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