| 5211. |
- Ahlqvist, Emma, et al.
(författare)
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The genetics of type 2 diabetes
- 2015. - 4th
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Ingår i: International Textbook of Diabetes Mellitus. - : Wiley. - 9780470658611 - 9781118387658 ; , s. 401-412
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Bokkapitel (refereegranskat)
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| 5212. |
- Ahluwalia, Tarun, et al.
(författare)
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Common variants in CNDP1 and CNDP2, and risk of nephropathy in type 2 diabetes.
- 2011
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Ingår i: Diabetologia. - : Springer Science and Business Media LLC. - 1432-0428 .- 0012-186X. ; 54, s. 2295-2302
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Tidskriftsartikel (refereegranskat)abstract
- AIMS/HYPOTHESIS: Several genome-wide linkage studies have shown an association between diabetic nephropathy and a locus on chromosome 18q harbouring two carnosinase genes, CNDP1 and CNDP2. Carnosinase degrades carnosine (β-alanyl-L-: histidine), which has been ascribed a renal protective effect as a scavenger of reactive oxygen species. We investigated the putative associations of genetic variants in CNDP1 and CNDP2 with diabetic nephropathy (defined either as micro- or macroalbuminuria) and estimated GFR in type 2 diabetic patients from Sweden. METHODS: We genotyped nine single nucleotide polymorphisms (SNPs) and one trinucleotide repeat polymorphism (D18S880, five to seven leucine repeats) in CNDP1 and CNDP2 in a case-control set-up including 4,888 unrelated type 2 diabetic patients (with and without nephropathy) from Sweden (Scania Diabetes Registry). RESULTS: Two SNPs, rs2346061 in CNDP1 and rs7577 in CNDP2, were associated with an increased risk of diabetic nephropathy (rs2346061 p = 5.07 × 10(-4); rs7577 p = 0.021). The latter was also associated with estimated GFR (β = -0.037, p = 0.014), particularly in women. A haplotype including these SNPs (C-C-G) was associated with a threefold increased risk of diabetic nephropathy (OR 2.98, 95% CI 2.43-3.67, p < 0.0001). CONCLUSIONS/INTERPRETATION: These data suggest that common variants in CNDP1 and CNDP2 play a role in susceptibility to kidney disease in patients with type 2 diabetes.
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| 5213. |
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| 5214. |
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| 5215. |
- Ahmad, Abrar, et al.
(författare)
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Precision Prognostics for Cardiovascular Disease in Type 2 Diabetes : A Systematic Review and Meta-analysis
- 2023
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- BACKGROUND: Precision medicine has the potential to improve cardiovascular disease (CVD) risk prediction in individuals with type 2 diabetes (T2D).METHODS: We conducted a systematic review and meta-analysis of longitudinal studies to identify potentially novel prognostic factors that could improve CVD risk prediction in T2D. Out of 9380 studies identified, 416 studies met inclusion criteria. Outcomes were reported for 321 biomarker studies, 48 genetic marker studies, and 47 risk score/model studies.Out of all evaluated biomarkers, only 13 showed improvement in prediction performance. Results of pooled meta-analyses, non-pooled analyses, and assessments of improvement in prediction performance and risk of bias, yielded the highest predictive utility for N-terminal pro b-type natriuretic peptide (NT-proBNP) (high-evidence), troponin-T (TnT) (moderate-evidence), triglyceride-glucose (TyG) index (moderate-evidence), Genetic Risk Score for Coronary Heart Disease (GRS-CHD) (moderate-evidence); moderate predictive utility for coronary computed tomography angiography (low-evidence), single-photon emission computed tomography (low-evidence), pulse wave velocity (moderate-evidence); and low predictive utility for C-reactive protein (moderate-evidence), coronary artery calcium score (low-evidence), galectin-3 (low-evidence), troponin-I (low-evidence), carotid plaque (low-evidence), and growth differentiation factor-15 (low-evidence). Risk scores showed modest discrimination on internal validation, with lower performance on external validation.CONCLUSIONS: Despite high interest in this topic, very few studies conducted rigorous analyses to demonstrate incremental predictive utility beyond established CVD risk factors for T2D. The most promising markers identified were NT-proBNP, TnT, TyG and GRS-CHD, with the highest strength of evidence for NT-proBNP. Further research is needed to determine their clinical utility in risk stratification and management of CVD in T2D.PLAIN LANGUAGE SUMMARY: Patients with T2D are at high risk for CVD but predicting who will experience a cardiac event is challenging. Current risk tools and prognostic factors, such as laboratory tests, may not accurately predict risk in different patient populations. There is a need for personalized risk prediction tools to identify patients more accurately so that CVD prevention can be targeted to those who need it most. This study examined novel biomarkers, genetic markers, and risk scores on the prediction of CVD in individuals with T2D. We found that four laboratory markers and a genetic risk score for CHD had high predictive utility beyond traditional CVD risk factors and that risk scores had modest predictive utility when tested in diverse populations, but more studies are needed to determine their usefulness in clinical practice. The highest strength of evidence was observed for NT-proBNP, a laboratory test currently used to monitor patients with heart failure but not currently used in clinical practice for the purpose of CVD prediction in T2D.
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| 5216. |
- Ahmad, Faiyaz, et al.
(författare)
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Adenovirus-mediated overexpression of murine cyclic nucleotide phosphodiesterase 3B
- 2005
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Ingår i: Methods in molecular biology (Clifton, N.J.). - New Jersey : Humana Press. - 1940-6029 .- 1064-3745. ; 307, s. 93-107
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- To construct the recombinant adenovirus vector containing the cDNA for recombinant mouse cyclic nucleotide phosphodiesterase 3B (mPDE3B), the cDNA for mPDE3B was subcloned into pACCMV.pLpA. Subsequently, this recombinant plasmid, pACCMV.mPDE3B, was cotransfected with pJM17 plasmid containing the adenoviral genome into 293 human embryonic kidney cells, and the replication-deficient adenovirus AdCMV.mPDE3B was generated via homologous recombination. Large-scale preparation of adenovirus yielded 10(11)-10(13) viral particles/mL and could be quantitated by real-time polymerase chain reaction using iCycler (Bio-Rad). Efficiency of gene transfer was assessed by infecting FDCP2 or H4IIE cells with a recombinant adenovirus expressing beta-galactosidase (beta-gal); greater than 75% of cells were infected. Expression of mPDE3B in H4IIE hepatoma cells, FDCP2 hematopoietic cells, and beta-cells from isolated pancreatic islets was detected by Western blot analysis. In lysates from FDCP2 cells and H4IIE hepatoma cells infected with recombinant adenoviral mPDE3B constructs, mPDE3B activity was increased 10- to 30-fold compared with the activity in lysates from cells infected with beta-gal adenovirus. Stimulation of FDCP2 cells infected with mPDE3B adenovirus with insulin (100 nM, 10 min) resulted in an approx 1.7-fold increase in endogenous PDE3B and recombinant wild-type PDE3B activities. Infection of rat pancreatic islets resulted in a 5- to 10-fold increase in PDE3B expression and activity and subsequent blunting of insulin secretion. Thus, adenovirus-mediated gene transfer is effective for studying expression and regulation of recombinant PDE3 in insulin-responsive cells as well as insulin-secreting cells.
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| 5217. |
- Ahmad, F., et al.
(författare)
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Cyclic Nucleotide Phosphodiesterase 3 Signaling Complexes
- 2012
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Ingår i: Hormone and Metabolic Research. - : Georg Thieme Verlag KG. - 1439-4286 .- 0018-5043. ; 44:10, s. 776-785
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Forskningsöversikt (refereegranskat)abstract
- The superfamily of cyclic nucleotide phosphodiesterases is comprised of 11 gene families. By hydrolyzing cAMP and cGMP, PDEs are major determinants in the regulation of intracellular concentrations of cyclic nucleotides and cyclic nucleotide-dependent signaling pathways. Two PDE3 subfamilies, PDE3A and PDE3B, have been described. PDE3A and PDE3B hydrolyze cAMP and cGMP with high affinity in a mutually competitive manner and are regulators of a number of important cAMP- and cGMP-mediated processes. PDE3B is relatively more highly expressed in cells of importance for the regulation of energy homeostasis, including adipocytes, hepatocytes, and pancreatic beta-cells, whereas PDE3A is more highly expressed in heart, platelets, vascular smooth muscle cells, and oocytes. Major advances have been made in understanding the different physiological impacts and biochemical basis for recruitment and subcellular localizations of different PDEs and PDE-containing macromolecular signaling complexes or signalosomes. In these discrete compartments, PDEs control cyclic nucleotide levels and regulate specific physiological processes as components of individual signalosomes which are tethered at specific locations and which contain PDEs together with cyclic nucleotide-dependent protein kinases (PKA and PKG), adenylyl cyclases, Epacs (guanine nucleotide exchange proteins activated by cAMP), phosphoprotein phosphatases, A-Kinase anchoring proteins (AKAPs), and pathway-specific regulators and effectors. This article highlights the identification of different PDE3A- and PDE3B-containing signalosomes in specialized subcellular compartments, which can increase the specificity and efficiency of intracellular signaling and be involved in the regulation of different cAMP-mediated metabolic processes.
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| 5218. |
- Ahmad, Faiyaz, et al.
(författare)
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Regulation of SERCA2 activity by PDE3A in human myocardium: Phosphorylation-dependent interaction of PDE3A1 with SERCA2.
- 2015
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Ingår i: Journal of Biological Chemistry. - 1083-351X. ; 290:11, s. 6763-6776
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Tidskriftsartikel (refereegranskat)abstract
- PDE3 regulates cAMP-mediated signaling in the heart, and PDE3 inhibitors augment contractility in patients with heart failure. Studies in mice showed that PDE3A, not PDE3B, is the subfamily responsible for these inotropic effects, and that murine PDE3A1 associates with SERCA2, PLB and AKAP18 in a multi-protein signalosome in human SR. Immunohistochemical staining demonstrated that PDE3A co-localizes in Z-bands of human cardiac myocytes with desmin, SERCA2, PLB and AKAP18. In human SR fractions, cAMP increased PLB phosphorylation and SERCA2 activity; this was potentiated by PDE3 inhibition but not by PDE4 inhibition. During gel-filtration chromatography of solubilized SR membranes, PDE3 activity was recovered in distinct HMW and LMW peaks. HMW peaks contained PDE3A1 and PDE3A2, while LMW peaks contained PDE3A1, PDE3A2 and PDE3A3. Western blotting showed that endogenous HMW PDE3A1 was the principal PKA-phosphorylated isoform. Phosphorylation of endogenous PDE3A by rPKAc increased cAMP-hydrolytic activity, correlated with shift of PDE3A from LMW to HMW peaks, and increased co-immumoprecipitation of SERCA2, cav3, PKARII, PP2A and AKAP18 with PDE3A. In experiments with recombinant proteins, phosphorylation of rhPDE3A isoforms by rPKAc increased co-immumoprecipitation with rSERCA2 and rAKAP18. Deletion of the rhPDE3A1/PDE3A2 N-terminus blocked interactions with rSERCA2. Serine-to-alanine substitutions identified S292/S293, a site unique to hPDE3A1, as the principal site regulating its interaction with SERCA2. These results indicate that phosphorylation of hPDE3A1 at a PKA site in its unique N-terminal extension promotes its incorporation into SERCA2/AKAP18 signalosomes, where it regulates a discrete cAMP pool that controls contractility by modulating phosphorylation-dependent protein-protein interactions, PLB phosphorylation and SERCA2 activity.
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| 5219. |
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| 5220. |
- Ahmad, Shafqat
(författare)
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Genetic and Environmental Risk Factors in the Development of Obesity
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Lifestyle behaviors and genetic variation have clear and distinguishable effects on obesity risk; however, the pattern of disease occurrence within and between populations that differ in their genetic and environmental underpinnings suggests obesity is caused in part by the interaction between adverse lifestyle behaviors and the genetic risk profile of an individual. This thesis aims to investigate the joint effects of genetic and environmental (specifically lifestyle) risk factors for obesity and its comorbidities using cross-sectional and longitudinal epidemiological cohorts and clinical trials. Characterizing interactions may help optimize prevention and treatment strategies by identifying risk groups of people for targeted interventions. The work in this thesis was conducted in the cross-sectional European ancestry sample of 111,421 individuals from the GLACIER, MDC, INTER99, HEALTH2006, HPFS, NHS, WGHS, InterAct, MESTSIM, TwinGene cohorts (paper I), 14,131 Pakistani adults from the PROMIS cohort (paper II), 3,541 adult from the prospective GLACIER Study (paper III) and in 5,730 participants of the DPP and Look AHEAD clinical trial (paper IV). In paper I, we reported that physical activity, assessed by the Cambridge physical activity index, diminishes the genetic risk of obesity predisposed by 12 BMIassociated genetic variants (Pinteraction=0.015). In sensitivity analyses, the interaction was only evident in the Northern American (N= 39,810) but not the European (N= 71,611) cohorts. In paper II, by employing genomewide heterogeneity of variance approach in GWAS data in PROMIS study, we identified one locus, FLJ33534 rs140133294 that associated with variance of BMI (P-value of 3.1 x 10-8). In subsequent analysis the association of this locus on BMI was found to be significant modified by smoking (Pinteraction= 0.0005). In paper III, we a genetic risk score based upon 97 BMI-associated genetic variants was significantly associated with change in BMI (β=0.014 kg/m2 per allele per 10-year follow-up, SE= 0.006, P=0.015). Three of the BMI- loci (PARK2 rs13191362, C6orf106 rs205262, C9orf93 rs4740619) were individually significantly associated with 10 year change in BMI. In paper IV, we observed that lifestyle interventions modified the response of MTIF3 rs1885988 genetic variant to weight loss. In the meta-analyzed sample of DPP and Look AHEAD, each copy of the minor Gallele at MTIF3 rs1885988 was associated with weight loss across all four years of the lifestyle interventions (P= 2.4×10-3), while no association with weight loss was observed in the control arm (P= 0.11). In conclusion, this thesis work shows that gene-lifestyle interactions influence human weight maintenance on several levels, although the clinical relevance remains to be determined.
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