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- Karpale, Mikko, et al.
(författare)
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Activation of nuclear receptor PXR induces atherogenic lipids and PCSK9 through SREBP2-mediated mechanism
- 2021
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Ingår i: British Journal of Pharmacology. - : Macmillan Publishers Ltd.. - 0007-1188 .- 1476-5381. ; 178:12, s. 2461-2481
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE: Many drugs and environmental contaminants induce hypercholesterolemia and promote the risk of atherosclerotic cardiovascular disease. The mechanisms involved are poorly defined precluding efficient prediction and prevention. We tested the hypothesis that pregnane X receptor (PXR), a xenobiotic-sensing nuclear receptor, regulates the level of circulating atherogenic lipids in humans and utilized mouse experiments to identify the mechanisms involved.EXPERIMENTAL APPROACH: We performed serum NMR metabolomics in healthy volunteers administered rifampicin, a prototypical human PXR ligand, or placebo in a crossover setting. Furthermore, we used high-fat diet fed wildtype and PXR knockout mice to investigate the mechanisms and pathways mediating the PXR-induced alterations in cholesterol homeostasis.KEY RESULTS: Activation of PXR induced cholesterogenesis both in pre-clinical and clinical settings. In human volunteers, rifampicin increased IDL, LDL and total cholesterol and lathosterol-cholesterol ratio, a marker of cholesterol synthesis, suggesting increased cholesterol synthesis. Mechanistic studies in mice indicated that PXR activation launches widespread induction of the cholesterol synthesis genes including the rate-limiting Hmgcr and upregulates the intermediates in the Kandutsch-Russell cholesterol synthesis pathway in the liver. Additionally, PXR activation induced plasma PCSK9, a negative regulator of hepatic LDL uptake, in both mice and humans. We propose that these effects were mediated through increased proteolytic activation of SREBP2 in response to PXR activation.CONCLUSION AND IMPLICATIONS: PXR activation induces cholesterol synthesis and elevates LDL and total cholesterol in humans. The PXR-SREBP2 pathway is a novel regulator of the cholesterol and PCSK9 synthesis, and a molecular mechanism for drug- and chemical-induced hypercholesterolemia.
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| 2. |
- Kraja, Aldi T., et al.
(författare)
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New Blood Pressure-Associated Loci Identified in Meta-Analyses of 475000 Individuals
- 2017
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Ingår i: Circulation. - : LIPPINCOTT WILLIAMS & WILKINS. - 1942-325X .- 1942-3268. ; 10:5
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Tidskriftsartikel (refereegranskat)abstract
- Background - Genome-wide association studies have recently identified >400 loci that harbor DNA sequence variants that influence blood pressure (BP). Our earlier studies identified and validated 56 single nucleotide variants (SNVs) associated with BP from meta-analyses of exome chip genotype data. An additional 100 variants yielded suggestive evidence of association.Methods and Results - Here, we augment the sample with 140886 European individuals from the UK Biobank, in whom 77 of the 100 suggestive SNVs were available for association analysis with systolic BP or diastolic BP or pulse pressure. We performed 2 meta-analyses, one in individuals of European, South Asian, African, and Hispanic descent (pan-ancestry, approximate to 475000), and the other in the subset of individuals of European descent (approximate to 423000). Twenty-one SNVs were genome-wide significant (P<5x10(-8) ) for BP, of which 4 are new BP loci: rs9678851 (missense, SLC4A1AP), rs7437940 (AFAP1), rs13303 (missense, STAB1), and rs1055144 (7p15.2). In addition, we identified a potentially independent novel BP-associated SNV, rs3416322 (missense, SYNPO2L) at a known locus, uncorrelated with the previously reported SNVs. Two SNVs are associated with expression levels of nearby genes, and SNVs at 3 loci are associated with other traits. One SNV with a minor allele frequency <0.01, (rs3025380 at DBH) was genome-wide significant.Conclusions - We report 4 novel loci associated with BP regulation, and 1 independent variant at an established BP locus. This analysis highlights several candidate genes with variation that alter protein function or gene expression for potential follow-up.
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| 3. |
- Molander, Pauliina, et al.
(författare)
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Tofacitinib real-world experience in ulcerative colitis in Finland (FinTofUC) : a retrospective non-interventional multicenter patient chart data study
- 2024
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Ingår i: Scandinavian Journal of Gastroenterology. - : Taylor & Francis. - 0036-5521 .- 1502-7708. ; 59:4, s. 425-432
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Tidskriftsartikel (refereegranskat)abstract
- ObjectivesThe aim was to define the effectiveness of tofacitinib and to characterize the patient population receiving tofacitinib in a real-world cohort clinical setting for ulcerative colitis (UC) in Finland.MethodsThis is a retrospective non-interventional multicenter patient chart data study conducted in 23 Finnish Inflammatory Bowel Disease (IBD) centers. Baseline demographic and clinical data, clinical remission, steroid-free remission rate and time to tofacitinib discontinuation, colectomy or UC-related hospitalization were studied.ResultsThe study included 252 UC patients of which 69% were male. Most patients had extensive disease (71%) and were bio-experienced (81%). Tofacitinib demonstrated positive treatment outcomes with clinical response, clinical remission, and steroid-free clinical remission at one year in 33%, 34% and 31% of patients, respectively. Moreover, 64% of patients in pMayo remission at week 16 from the start of tofacitinib were still in remission at one year. Only no or mild disease activity compared to moderate activity at baseline was associated with a higher probability of achieving remission according to pMayo at six months, p = .008. Hospitalizations and/or colectomies during the study period (before treatment discontinuation/end of follow-up) were low (n = 24), with less than 5 colectomies.ConclusionsIn this real-world cohort, including a majority of bio-experienced UC patients, tofacitinib was effective in achieving steroid-free clinical remission in a third of the population at one year. A majority of patients in remission at week 16 were also in remission at one year. Results are in line with earlier published real-world studies. Registration: ClinicalTrials.gov NCT05082428.
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| 4. |
- Surendran, Praveen, et al.
(författare)
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Trans-ancestry meta-analyses identify rare and common variants associated with blood pressure and hypertension
- 2016
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 48:10, s. 1151-1161
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Tidskriftsartikel (refereegranskat)abstract
- High blood pressure is a major risk factor for cardiovascular disease and premature death. However, there is limited knowledge on specific causal genes and pathways. To better understand the genetics of blood pressure, we genotyped 242,296 rare, low-frequency and common genetic variants in up to 192,763 individuals and used -1/4155,063 samples for independent replication. We identified 30 new blood pressure- or hypertension-associated genetic regions in the general population, including 3 rare missense variants in RBM47, COL21A1 and RRAS with larger effects (>1.5 mm Hg/allele) than common variants. Multiple rare nonsense and missense variant associations were found in A2ML1, and a low-frequency nonsense variant in ENPEP was identified. Our data extend the spectrum of allelic variation underlying blood pressure traits and hypertension, provide new insights into the pathophysiology of hypertension and indicate new targets for clinical intervention.
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