Browsing by Subject "ADIPOSE-TISSUE"

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  • Lluch, Aina; Veiga, Sonia R.; Latorre, Jèssica; Moreno-Navarrete, José M.; Bonifaci, Núria; Nguyen, Van Dien; Zhou, You; Höring, Marcus; Liebisch, Gerhard; Olkkonen, Vesa M.; Llobet-Navas, David; Thomas, George; Rodríguez-Barrueco, Ruth; Fernández-Real, José M.; Kozma, Sara C.; Ortega, Francisco J. (2022)
    The ribosomal protein S6 kinase 1 (S6K1) is a relevant effector downstream of the mammalian target of rapamycin complex 1 (mTORC1), best known for its role in the control of lipid homeostasis. Consistent with this, mice lacking the S6k1 gene have a defect in their ability to induce the commitment of fat precursor cells to the adipogenic lineage, which contributes to a significant reduction of fat mass. Here, we assess the therapeutic blockage of S6K1 in diet-induced obese mice challenged with LY2584702 tosylate, a specific oral S6K1 inhibitor initially developed for the treatment of solid tumors. We show that diminished S6K1 activity hampers fat mass expansion and ameliorates dyslipidemia and hepatic steatosis, while modifying transcriptome-wide gene expression programs relevant for adipose and liver function. Accordingly, decreased mTORC1 signaling in fat (but increased in the liver) segregated with defective epithelial-mesenchymal transition and the impaired expression of Cd36 (coding for a fatty acid translocase) and Lgals1 (Galectin 1) in both tissues. All these factors combined align with reduced adipocyte size and improved lipidomic signatures in the liver, while hepatic steatosis and hypertriglyceridemia were improved in treatments lasting either 3 months or 6 weeks.
  • Jew, Brandon; Alvarez, Marcus; Rahmani, Elior; Miao, Zong; Ko, Arthur; Garske, Kristina M.; Sul, Jae Hoon; Pietiläinen, Kirsi H.; Pajukanta, Päivi; Halperin, Eran (2020)
    We present Bisque, a tool for estimating cell type proportions in bulk expression. Bisque implements a regression-based approach that utilizes single-cell RNA-seq (scRNA-seq) or single-nucleus RNA-seq (snRNA-seq) data to generate a reference expression profile and learn gene-specific bulk expression transformations to robustly decompose RNA-seq data. These transformations significantly improve decomposition performance compared to existing methods when there is significant technical variation in the generation of the reference profile and observed bulk expression. Importantly, compared to existing methods, our approach is extremely efficient, making it suitable for the analysis of large genomic datasets that are becoming ubiquitous. When applied to subcutaneous adipose and dorsolateral prefrontal cortex expression datasets with both bulk RNA-seq and snRNA-seq data, Bisque replicates previously reported associations between cell type proportions and measured phenotypes across abundant and rare cell types. We further propose an additional mode of operation that merely requires a set of known marker genes.
  • Nath, Artika P.; Ritchie, Scott C.; Byars, Sean G.; Fearnley, Liam G.; Havulinna, Aki S.; Joensuu, Anni; Kangas, Antti J.; Soininen, Pasi; Wennerstrom, Annika; Milani, Lili; Metspalu, Andres; Mannisto, Satu; Wurtz, Peter; Kettunen, Johannes; Raitoharju, Emma; Kahonen, Mika; Juonala, Markus; Palotie, Aarno; Ala-Korpela, Mika; Ripatti, Samuli; Lehtimaki, Terho; Abraham, Gad; Raitakari, Olli; Salomaa, Veikko; Perola, Markus; Inouye, Michael (2017)
    Background: Immunometabolism plays a central role in many cardiometabolic diseases. However, a robust map of immune-related gene networks in circulating human cells, their interactions with metabolites, and their genetic control is still lacking. Here, we integrate blood transcriptomic, metabolomic, and genomic profiles from two population-based cohorts (total N = 2168), including a subset of individuals with matched multi-omic data at 7-year follow-up. Results: We identify topologically replicable gene networks enriched for diverse immune functions including cytotoxicity, viral response, B cell, platelet, neutrophil, and mast cell/basophil activity. These immune gene modules show complex patterns of association with 158 circulating metabolites, including lipoprotein subclasses, lipids, fatty acids, amino acids, small molecules, and CRP. Genome-wide scans for module expression quantitative trait loci (mQTLs) reveal five modules with mQTLs that have both cis and trans effects. The strongest mQTL is in ARHGEF3 (rs1354034) and affects a module enriched for platelet function, independent of platelet counts. Modules of mast cell/basophil and neutrophil function show temporally stable metabolite associations over 7-year follow-up, providing evidence that these modules and their constituent gene products may play central roles in metabolic inflammation. Furthermore, the strongest mQTL in ARHGEF3 also displays clear temporal stability, supporting widespread trans effects at this locus. Conclusions: This study provides a detailed map of natural variation at the blood immunometabolic interface and its genetic basis, and may facilitate subsequent studies to explain inter-individual variation in cardiometabolic disease.
  • Mysore, Raghavendra; Liebisch, Gerhard; Zhou, You; Olkkonen, Vesa M.; Haridas, P. A. Nidhina (2017)
    Angiopoietin-like 8 (Angptl8) inhibits lipolysis in the circulation together with Angplt3 and controls post-prandial fat storage in white adipose tissue (WAT). It is strongly induced by insulin in vivo in WAT and in vitro in adipocytes. In this study we addressed the function of Angptl8 in adipocytes by its stable lentivirus-mediated knock-down in 3T3-L1 cells, followed by analyses of triglyceride (TG) storage, lipid droplet (LD) morphology, the cellular lipidome, lipolysis, and gene expression. Depletion of Angptl8 did not drastically affect the adipocyte differentiation of 3T3-L1 cells but resulted in a moderate (18-19%) reduction of stored TGs. The lipidome analysis revealed a reduction of alkyl-phosphatidylcholines (PCs) and phosphatidylethanolamine (PE) plasmalogens, as well as saturated PCs and PEs. Importantly, the Angptl8 depleted cells displayed enhanced lipolysis as measured by release of non-esterified fatty acids (NEFA5). Consistently, mRNAs encoding Angptl4 and Leptin, which facilitate lipolysis, as well as Cpt1a, Cpt1b, and Pgc-1 alpha involved in FA oxidation, were elevated. The Angptl8 mRNA itself was suppressed by pharmacologic treatments inducing lipolysis: stimulation with the beta-adrenergic agonist isoproterenol or with the adenylate cyclase activator forskolin. To conclude, knock-down of Angptl8 in adipocytes suggests that the protein acts to inhibit intracellular lipolysis, analogous to its activity in the circulation. Depletion of Angptl8 results in an altered cellular phospholipid composition. The findings identify Angptl8 as a central insulin-regulated controller of adipocyte lipid metabolism. (C) 2017 Elsevier B.V. All rights reserved.
  • Ruhanen, Hanna; Haridas, P. A. Nidhina; Jauhiainen, Matti; Olkkonen, Vesa M. (2020)
    Angiopoietin like protein 3 (ANGPTL3) is best known for its function as an inhibitor of lipoprotein and endothelial lipases. Due to the capacity of genetic or pharmacologic ANGPTL3 suppression to markedly reduce circulating lipoproteins, and the documented cardioprotection upon such suppression, ANGPTL3 has become an emerging therapy target for which both antibody and antisense oligonucleotide (ASO) therapeutics are being clinically tested. While the antibody is relatively selective for circulating ANGPTL3, the ASO also depletes the intra-hepatocellular protein, and there is emerging evidence for cell-autonomous functions of ANGPTL3 in the liver. These include regulation of hepatocyte glucose and fatty acid uptake, insulin sensitivity, LDL/VLDL remnant uptake, VLDL assembly/secretion, polyunsaturated fatty acid (PUFA) and PUFA-derived lipid mediator content, and gene expression. In this review we elaborate on (i) why ANGPTL3 is considered one of the most promising new cardiometabolic therapy targets, and (ii) the present evidences for its intra-hepatocellular or cell-autonomous functions.
  • Al-Ahmadi, Jawaher; Enani, Sumia; Bahijri, Suhad; Al-Raddadi, Rajaa; Jambi, Hanan; Eldakhakhny, Basmah; Borai, Anwar; Ajabnoor, Ghada; Tuomilehto, Jaakko (2022)
    Context: Waist circumference (WC) is used in screening for metabolic syndrome (MetS) based on its association with cardiometabolic risk.This might apply differently in ethnically different populations. Associations with other measures are also unclear. Objective: This work aimed to investigate the association between neck circumference (NC), WC, WC:hip circumference, WC:height (VVC:Ht), NC:Ht, fat percentage, body mass index (BMI), conicity index, abdominal volume index, and weight-adjusted waist index with nonanthropometric components of MetS in nondiabetic Saudi adults. Methods: This cross-sectional study took place in public health centers in Jeddah, comprising 1365 Saudi adults (772 men and 593 women) aged 18 years or older not previously diagnosed with diabetes. Main outcome measures included the presence of 2 or more nonanthropometric components of the MetS were used to define clinical metabolic abnormality (CMA). The predictive ability of studied anthropometric indices for CMA was determined using the area under receiver operating characteristics (AUC) curve and binary logistic regression. Results: A total of 157 men and 83 women had CMA. NC and NC:Ht had the highest predictive ability for CMA in men (odds ratio [OR](NC) = 1.79, P < .001 and ORNC:Ht = 1.68, P < .001; AUC(NC) = 0.69 [95% CI, 0.64-0.74] and ALS, = 0.69 [95% CI, 0.64-0.73]). In women, WC had the highest predictive ability ORWC = 1.81, P< .001; AUC(WC) = 0.75 [95% CI, 0.69-0.80]). Conclusion: Upper-body anthropometric indicators that were associated with subcutaneous fat had the highest predictive ability for CMA in men whereas abdominal obesity indictors had the best predictive ability in women, suggesting that fat distribution might contribute to CMA in a sex-specific manner.
  • Graner, M.; Gustavsson, S.; Nyman, Kristofer; Siren, R.; Pentikainen, M. O.; Lundbom, J.; Hakkarainen, A.; Lauerma, K.; Lundbom, N.; Boren, J.; Nieminen, M. S.; Taskinen, M. -R. (2016)
    Background and aims: Lipid oversupply to cardiomyocytes or decreased utilization of lipids leads to cardiac steatosis. We aimed to examine the role of different circulating metabolic biomarkers as predictors of myocardial triglyceride (TG) content in non-diabetic men. Methods and results: Myocardial and hepatic TG contents were measured with 1.5 T magnetic resonance (MR) spectroscopy, and LV function, visceral adipose tissue (VAT), abdominal subcutaneous tissue (SAT), epicardial and pericardial fat by MR imaging in 76 non-diabetic men. Serum concentration of circulating metabolic biomarkers [adiponectin, leptin, adipocyte-fatty acid binding protein 4 (A-FABP 4), resistin, and lipocalin-2] including beta-hydroxybuturate (beta-OHB) were measured. Subjects were stratified by tertiles of myocardial TG into low, moderate, and high myocardial TG content groups. Concentrations of beta-OHB were lower (p = 0.003) and serum levels of A-FABP 4 were higher (p <0.001) in the group with high myocardial TG content compared with the group with low myocardial TG content. beta-OHB was negatively correlated with myocardial TG content (r = -0.316, p = 0.006), whereas A-FABP 4 was not correlated with myocardial TG content (r = 0.192, p = 0.103). In multivariable analyses beta-OHB and plasma glucose levels were the best predictors of myocardial TG content independently of VAT and hepatic TG content. The model explained 58.8% of the variance in myocardial TG content. Conclusion: Our data showed that beta-OHB and fasting glucose were the best predictors of myocardial TG content in non-diabetic men. These data suggest that hyperglycemia and alterations in lipid oxidation may be associated with cardiac steatosis in humans. (C) 2015 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.
  • Bacos, Karl; Gillberg, Linn; Volkov, Petr; Olsson, Anders H.; Hansen, Torben; Pedersen, Oluf; Gjesing, Anette Prior; Eiberg, Hans; Tuomi, Tiinamaija; Almgren, Peter; Groop, Leif; Eliasson, Lena; Vaag, Allan; Dayeh, Tasnim; Ling, Charlotte (2016)
    Aging associates with impaired pancreatic islet function and increased type 2 diabetes (T2D) risk. Here we examine whether age-related epigenetic changes affect human islet function and if blood-based epigenetic biomarkers reflect these changes and associate with future T2D. We analyse DNA methylation genome-wide in islets from 87 non-diabetic donors, aged 26-74 years. Aging associates with increased DNA methylation of 241 sites. These sites cover loci previously associated with T2D, for example, KLF14. Blood-based epigenetic biomarkers reflect age-related methylation changes in 83 genes identified in human islets (for example, KLF14, FHL2, ZNF518B and FAM123C) and some associate with insulin secretion and T2D. DNA methylation correlates with islet expression of multiple genes, including FHL2, ZNF518B, GNPNAT1 and HLTF. Silencing these genes in beta-cells alter insulin secretion. Together, we demonstrate that blood-based epigenetic biomarkers reflect age-related DNA methylation changes in human islets, and associate with insulin secretion in vivo and T2D.
  • Blomqvist, Kim H.; Lundbom, Jesper; Lundbom, Nina; Sepponen, Raimo E. (2011)
  • Sievanen, Tero; Tormakangas, Timo; Laakkonen, Eija K.; Mecklin, Jukka-Pekka; Pylvänäinen, Kirsi; Seppälä, Toni T.; Peltomäki, Paivi; Sipila, Sarianna; Sillanpää, Elina (2021)
    Simple Summary Lifestyle modifies cancer risk in the general public. How lifestyle modifies cancer risk in individuals carrying the inherited pathogenic gene variants in DNA mismatch repair genes (Lynch syndrome) remains understudied. We conducted a retrospective study with cancer register data to investigate associations between body weight, physical activity, and cancer risk among Finnish Lynch syndrome carriers (n = 465, 54% women). The results of our study indicated that longitudinal weight gain increases cancer risk, whereas being highly physically active during adulthood could decrease cancer risk in men. Further, women were observed to be less prone to lifestyle-related risk factors than men. The results emphasize the role of weight maintenance and high-intensity physical activity throughout the lifespan, especially in men with Lynch syndrome. Lynch syndrome (LS) increases cancer risk. There is considerable individual variation in LS cancer occurrence, which may be moderated by lifestyle factors, such as body weight and physical activity (PA). The potential associations of lifestyle and cancer risk in LS are understudied. We conducted a retrospective study with cancer register data to investigate associations between body weight, PA, and cancer risk among Finnish LS carriers. The participants (n = 465, 54% women) self-reported their adulthood body weight and PA at 10-year intervals. Overall cancer risk and colorectal cancer (CRC) risk was analyzed separately for men and women with respect to longitudinal and near-term changes in body weight and PA using extended Cox regression models. The longitudinal weight change was associated with an increased risk of all cancers (HR 1.02, 95% CI 1.00-1.04) and CRC (HR 1.03, 1.01-1.05) in men. The near-term weight change was associated with a lower CRC risk in women (HR 0.96, 0.92-0.99). Furthermore, 77.6% of the participants retained their PA category over time. Men in the high-activity group had a reduced longitudinal cancer risk of 63% (HR 0.37, 0.15-0.98) compared to men in the low-activity group. PA in adulthood was not associated with cancer risk among women. These results emphasize the role of weight maintenance and high-intensity PA throughout the lifespan in cancer prevention, particularly in men with LS.
  • Lovric, Alen; Graner, Marit; Bjornson, Elias; Arif, Muhammad; Benfeitas, Rui; Nyman, Kristofer; Ståhlman, Marcus; Pentikäinen, Markku O.; Lundbom, Jesper; Hakkarainen, Antti; Siren, Reijo; Nieminen, Markku S.; Lundbom, Nina; Lauerma, Kirsi; Taskinen, Marja-Riitta; Mardinoglu, Adil; Boren, Jan (2018)
    Non-alcoholic fatty liver disease (NAFLD) is recognized as a liver manifestation of metabolic syndrome, accompanied with excessive fat accumulation in the liver and other vital organs. Ectopic fat accumulation was previously associated with negative effects at the systemic and local level in the human body. Thus, we aimed to identify and assess the predictive capability of novel potential metabolic biomarkers for ectopic fat depots in non-diabetic men with NAFLD, using the inflammation-associated proteome, lipidome and metabolome. Myocardial and hepatic triglycerides were measured with magnetic spectroscopy while function of left ventricle, pericardial and epicardial fat, subcutaneous and visceral adipose tissue were measured with magnetic resonance imaging. Measured ectopic fat depots were profiled and predicted using a Random Forest algorithm, and by estimating the Area Under the Receiver Operating Characteristic curves. We have identified distinct metabolic signatures of fat depots in the liver (TAG50:1, glutamate, diSM18:0 and CE20:3), pericardium (N-palmitoyl-sphinganine, HGF, diSM18:0, glutamate, and TNFSF14), epicardium (sphingomyelin, CE20:3, PC38:3 and TNFSF14), and myocardium (CE20:3, LAPTGF-beta 1, glutamate and glucose). Our analyses highlighted non-invasive biomarkers that accurately predict ectopic fat depots, and reflect their distinct metabolic signatures in subjects with NAFLD.
  • Yki-Järvinen, Hannele; Luukkonen, Panu K.; Hodson, Leanne; Moore, J. Bernadette (2021)
    This Review discusses the role of dietary fats and carbohydrates in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). Studies on the dietary habits of patients with NAFLD, and the effect on liver fat accumulation of altering dietary macronutrients, are also reviewed. The global prevalence of nonalcoholic fatty liver disease (NAFLD) has dramatically increased in parallel with the epidemic of obesity. Controversy has emerged around dietary guidelines recommending low-fat-high-carbohydrate diets and the roles of dietary macronutrients in the pathogenesis of metabolic disease. In this Review, the topical questions of whether and how dietary fats and carbohydrates, including free sugars, differentially influence the accumulation of liver fat (specifically, intrahepatic triglyceride (IHTG) content) are addressed. Focusing on evidence from humans, we examine data from stable isotope studies elucidating how macronutrients regulate IHTG synthesis and disposal, alter pools of bioactive lipids and influence insulin sensitivity. In addition, we review cross-sectional studies on dietary habits of patients with NAFLD and randomized controlled trials on the effects of altering dietary macronutrients on IHTG. Perhaps surprisingly, evidence to date shows no differential effects between free sugars, with both glucose and fructose increasing IHTG in the context of excess energy. Moreover, saturated fat raises IHTG more than polyunsaturated or monounsaturated fats, with adverse effects on insulin sensitivity, which are probably mediated in part by increased ceramide synthesis. Taken together, the data support the use of diets that have a reduced content of free sugars, refined carbohydrates and saturated fat in the treatment of NAFLD.
  • Dayeh, Tasnim; Tuomi, Tiinamaija; Almgren, Peter; Perfilyev, Alexander; Jansson, Per-Anders; de Mello, Vanessa D.; Pihlajamaki, Jussi; Vaag, Allan; Groop, Leif; Nilsson, Emma; Ling, Charlotte (2016)
    Identification of subjects with a high risk of developing type 2 diabetes (T2D) is fundamental for prevention of the disease. Consequently, it is essential to search for new biomarkers that can improve the prediction of T2D. The aim of this study was to examine whether 5 DNA methylation loci in blood DNA (ABCG1, PHOSPHO1, SOCS3, SREBF1, and TXNIP), recently reported to be associated with T2D, might predict future T2D in subjects from the Botnia prospective study. We also tested if these CpG sites exhibit altered DNA methylation in human pancreatic islets, liver, adipose tissue, and skeletal muscle from diabetic vs. non-diabetic subjects. DNA methylation at the ABCG1 locus cg06500161 in blood DNA was associated with an increased risk for future T2D (OR = 1.09, 95% CI = 1.02-1.16, P-value = 0.007, Q-value = 0.018), while DNA methylation at the PHOSPHO1 locus cg02650017 in blood DNA was associated with a decreased risk for future T2D (OR = 0.85, 95% CI = 0.75-0.95, P-value = 0.006, Q-value = 0.018) after adjustment for age, gender, fasting glucose, and family relation. Furthermore, the level of DNA methylation at the ABCG1 locus cg06500161 in blood DNA correlated positively with BMI, HbA1c, fasting insulin, and triglyceride levels, and was increased in adipose tissue and blood from the diabetic twin among monozygotic twin pairs discordant for T2D. DNA methylation at the PHOSPHO1 locus cg02650017 in blood correlated positively with HDL levels, and was decreased in skeletal muscle from diabetic vs. non-diabetic monozygotic twins. DNA methylation of cg18181703 (SOCS3), cg11024682 (SREBF1), and cg19693031 (TXNIP) was not associated with future T2D risk in subjects from the Botnia prospective study.
  • Luukkonen, Panu K.; Dufour, Sylvie; Lyu, Kun; Zhang, Xian-Man; Hakkarainen, Antti; Lehtimäki, Tiina E.; Cline, Gary W.; Petersen, Kitt Falk; Shulman, Gerald I.; Yki-Järvinen, Hannele (2020)
    Weight loss by ketogenic diet (KD) has gained popularity in management of nonalcoholic fatty liver disease (NAFLD). KD rapidly reverses NAFLD and insulin resistance despite increasing circulating nonesterified fatty acids (NEFA), the main substrate for synthesis of intrahepatic triglycerides (IHTG). To explore the underlying mechanism, we quantified hepatic mitochondrial fluxes and their regulators in humans by using positional isotopomer NMR tracer analysis. Ten overweight/obese subjects received stable isotope infusions of: [D-7]glucose, [C-13(4)]beta-hydroxybutyrate and [3-C-13]lactate before and after a 6-d KD. IHTG was determined by proton magnetic resonance spectroscopy (H-1-MRS). The KD diet decreased IHTG by 31% in the face of a 3% decrease in body weight and decreased hepatic insulin resistance (-58%) despite an increase in NEFA concentrations (+35%). These changes were attributed to increased net hydrolysis of IHTG and partitioning of the resulting fatty acids toward keto-genesis (+232%) due to reductions in serum insulin concentrations (-53%) and hepatic citrate synthase flux (-38%), respectively. The former was attributed to decreased hepatic insulin resistance and the latter to increased hepatic mitochondrial redox state (+167%) and decreased plasma leptin (-45%) and triiodothyronine (-21%) concentrations. These data demonstrate heretofore unde-scribed adaptations underlying the reversal of NAFLD by KD: That is, markedly altered hepatic mitochondrial fluxes and redox state to promote ketogenesis rather than synthesis of IHTG.
  • Kokkonen, Tuomo Juhani; Salin, Siru; Jaakkola, Seija Liisa; Taponen, Juhani Olavi; Elo, Kari Tapani; Vanhatalo, Aila Orvokki (2018)
    The aim was to study if overconsumption of grass silage during the far-off dry period (FODP) and decreasing feed allowance in close-up dry period (CUDP) affect body condition score (BCS) and body weight (BW) changes, as well as lactation performance and body tissue mobilization after calving in dairy cows. Control diet (CON) was fed to meet the metabolizable energy (ME) requirements, the test diet (HEI) averaged 144% and 119% of ME requirements in the FODP and CUDP, respectively. All cows were fed concentrates in the CUDP (30% of ME d(-1)). Plasma non-esterified fatty acids (NEFA) were lower and insulin tended to be higher in HEI vs. CON prepartum. No dietary effects in accretion or mobilization of body reserves were observed, and accordingly no differences in silage DMI, ME balance and plasma parameters postpartum were detected. Concentrate DMI and milk yield tended to be lower in HEI vs. CON during early lactation.
  • Spracklen, Cassandra N.; Karaderi, Tugce; Yaghootkar, Hanieh; Schurmann, Claudia; Fine, Rebecca S.; Kutalik, Zoltan; Preuss, Michael H.; Lu, Yingchang; Wittemans, Laura B. L.; Adair, Linda S.; Allison, Matthew; Amin, Najaf; Auer, Paul L.; Bartz, Traci M.; Blueher, Matthias; Boehnke, Michael; Borja, Judith B.; Bork-Jensen, Jette; Broer, Linda; Chasman, Daniel I.; Chen, Yii-Der Ida; Chirstofidou, Paraskevi; Demirkan, Ayse; van Duijn, Cornelia M.; Feitosa, Mary F.; Garcia, Melissa E.; Graff, Mariaelisa; Grallert, Harald; Grarup, Niels; Guo, Xiuqing; Haesser, Jeffrey; Hansen, Torben; Harris, Tamara B.; Highland, Heather M.; Hong, Jaeyoung; Ikram, M. Arfan; Ingelsson, Erik; Jackson, Rebecca; Jousilahti, Pekka; Kahonen, Mika; Kizer, Jorge R.; Kovacs, Peter; Kriebel, Jennifer; Laakso, Markku; Lange, Leslie A.; Lehtimaki, Terho; Li, Jin; Ruifang Li-Gao; Lind, Lars; Luan, Jian'an; Lyytikainen, Leo-Pekka; MacGregor, Stuart; Mackey, David A.; Mahajan, Anubha; Mangino, Massimo; Männistö, Satu; McCarthy, Mark I.; McKnight, Barbara; Medina-Gomez, Carolina; Meigs, James B.; Molnos, Sophie; Mook-Kanamori, Dennis; Morris, Andrew P.; de Mutsert, Renee; Nalls, Mike A.; Nedeljkovic, Ivana; North, Kari E.; Pennell, Craig E.; Pradhan, Aruna D.; Province, Michael A.; Raitakari, Olli T.; Raulerson, Chelsea K.; Reiner, Alex P.; Ridker, Paul M.; Ripatti, Samuli; Roberston, Neil; Rotter, Jerome I.; Salomaa, Veikko; Sandoval-Zarate, America A.; Sitlani, Colleen M.; Spector, Tim D.; Strauch, Konstantin; Stumvoll, Michael; Taylor, Kent D.; Thuesen, Betina; Toenjes, Anke; Uitterlinden, Andre G.; Venturini, Cristina; Walker, Mark; Wang, Carol A.; Wang, Shuai; Wareham, Nicholas J.; Willems, Sara M.; van Dijk, Ko Willems; Wilson, James G.; Wu, Ying; Yao, Jie; Young, Kristin L.; Langenberg, Claudia; Frayling, Timothy M.; Kilpelainen, Tuomas O.; Lindgren, Cecilia M.; Loos, Ruth J. F.; Mohlke, Karen L. (2019)
    Circulating levels of adiponectin, an adipocyte-secreted protein associated with cardiovascular and metabolic risk, are highly heritable. To gain insights into the biology that regulates adiponectin levels, we performed an exome array meta-analysis of 265,780 genetic variants in 67,739 individuals of European, Hispanic, African American, and East Asian ancestry. We identified 20 loci associated with adiponectin, including 11 that had been reported previously (p <2 x 10(-7)). Comparison of exome array variants to regional linkage disequilibrium (LD) patterns and prior genome-wide association study (GWAS) results detected candidate variants (r(2) > .60) spanning as much as 900 kb. To identify potential genes and mechanisms through which the previously unreported association signals act to affect adiponectin levels, we assessed cross-trait associations, expression quantitative trait loci in subcutaneous adipose, and biological pathways of nearby genes. Eight of the nine loci were also associated (p <1 x 10(-4)) with at least one obesity or lipid trait. Candidate genes include PRKAR2A, PTH1R, and HDAC9, which have been suggested to play roles in adipocyte differentiation or bone marrow adipose tissue. Taken together, these findings provide further insights into the processes that influence circulating adiponectin levels.
  • Huovinen, Ville; Bucci, Marco; Lipponen, Heta; Kiviranta, Riku; Sandboge, Samuel; Raiko, Juho; Koskinen, Suvi; Koskensalo, Kalle; Eriksson, Johan G.; Parkkola, Riitta; Iozzo, Patricia; Nuutila, Pirjo (2016)
    Bone marrow insulin sensitivity may be an important factor for bone health in addition to bone mineral density especially in insulin resistant conditions. First we aimed to study if prenatal maternal obesity plays a role in determining bone marrow insulin sensitivity in elderly female offspring. Secondly we studied if a four-month individualized resistance training intervention increases bone marrow insulin sensitivity in elderly female offspring and whether this possible positive outcome is regulated by the offspring's mother's obesity status. 37 frail elderly females (mean age 71.9 +/- 3.1 years) of which 20 were offspring of lean/normal-weight mothers (OLM, maternal BMI = 28.1 kg/m(2)) were studied before and after a four-month individualized resistance training intervention. Nine age-and sex-matched non-frail controls (maternal BMI
  • Gusarova, Viktoria; O'Dushlaine, Colm; Teslovich, Tanya M.; Benotti, Peter N.; Mirshahi, Tooraj; Gottesman, Omri; Van Hout, Cristopher V.; Murray, Michael F.; Mahajan, Anubha; Nielsen, Jonas B.; Fritsche, Lars; Wulff, Anders Berg; Gudbjartsson, Daniel F.; Sjogren, Marketa; Emdin, Connor A.; Scott, Robert A.; Lee, Wen-Jane; Small, Aeron; Kwee, Lydia C.; Dwivedi, Om Prakash; Prasad, Rashmi B.; Bruse, Shannon; Lopez, Alexander E.; Penn, John; Marcketta, Anthony; Leader, Joseph B.; Still, Christopher D.; Kirchner, H. Lester; Mirshahi, Uyenlinh L.; Wardeh, Amr H.; Hartle, Cassandra M.; Habegger, Lukas; Fetterolf, Samantha N.; Tusie-Luna, Teresa; Morris, Andrew P.; Holm, Hilma; Steinthorsdottir, Valgerdur; Sulem, Patrick; Thorsteinsdottir, Unnur; Rotter, Jerome I.; Chuang, Lee-Ming; Damrauer, Scott; Birtwell, David; Brummett, Chad M.; Khera, Amit V.; Natarajan, Pradeep; Orho-Melander, Marju; Flannick, Jason; Lotta, Luca A.; Hansson, Ola; Groop, Leif (2018)
    Angiopoietin-like 4 (ANGPTL4) is an endogenous inhibitor of lipoprotein lipase that modulates lipid levels, coronary atherosclerosis risk, and nutrient partitioning. We hypothesize that loss of ANGPTL4 function might improve glucose homeostasis and decrease risk of type 2 diabetes (T2D). We investigate protein-altering variants in ANGPTL4 among 58,124 participants in the DiscovEHR human genetics study, with follow-up studies in 82,766 T2D cases and 498,761 controls. Carriers of p.E40K, a variant that abolishes ANGPTL4 ability to inhibit lipoprotein lipase, have lower odds of T2D (odds ratio 0.89, 95% confidence interval 0.85-0.92, p = 6.3 x 10(-10)), lower fasting glucose, and greater insulin sensitivity. Predicted loss-of-function variants are associated with lower odds of T2D among 32,015 cases and 84,006 controls (odds ratio 0.71, 95% confidence interval 0.49-0.99, p = 0.041). Functional studies in Angptl4-deficient mice confirm improved insulin sensitivity and glucose homeostasis. In conclusion, genetic inactivation of ANGPTL4 is associated with improved glucose homeostasis and reduced risk of T2D.
  • Byars, Sean G.; Huang, Qin Qin; Gray, Lesley-Ann; Bakshi, Andrew; Ripatti, Samuli; Abraham, Gad; Stearns, Stephen C.; Inouye, Michael (2017)
    Traditional genome-wide scans for positive selection have mainly uncovered selective sweeps associated with monogenic traits. While selection on quantitative traits is much more common, very few signals have been detected because of their polygenic nature. We searched for positive selection signals underlying coronary artery disease (CAD) in worldwide populations, using novel approaches to quantify relationships between polygenic selection signals and CAD genetic risk. We identified new candidate adaptive loci that appear to have been directly modified by disease pressures given their significant associations with CAD genetic risk. These candidates were all uniquely and consistently associated with many different male and female reproductive traits suggesting selection may have also targeted these because of their direct effects on fitness. We found that CAD loci are significantly enriched for lifetime reproductive success relative to the rest of the human genome, with evidence that the relationship between CAD and lifetime reproductive success is antagonistic. This supports the presence of antagonistic-pleiotropic tradeoffs on CAD loci and provides a novel explanation for the maintenance and high prevalence of CAD in modern humans. Lastly, we found that positive selection more often targeted CAD gene regulatory variants using HapMap3 lymphoblastoid cell lines, which further highlights the unique biological significance of candidate adaptive loci underlying CAD. Our study provides a novel approach for detecting selection on polygenic traits and evidence that modern human genomes have evolved in response to CAD-induced selection pressures and other early-life traits sharing pleiotropic links with CAD.
  • Hyötyläinen, Tuulia; Jerby, Livnat; Petäjä, Elina M.; Mattila, Ismo; Jäntti, Sirkku; Auvinen, Petri; Gastaldelli, Amalia; Yki-Järvinen, Hannele; Ruppin, Eytan; Oresic, Matej (2016)
    Non-alcoholic fatty liver disease (NAFLD) is a major risk factor leading to chronic liver disease and type 2 diabetes. Here we chart liver metabolic activity and functionality in NAFLD by integrating global transcriptomic data, from human liver biopsies, and metabolic flux data, measured across the human splanchnic vascular bed, within a genome-scale model of human metabolism. We show that an increased amount of liver fat induces mitochondrial metabolism, lipolysis, glyceroneogenesis and a switch from lactate to glycerol as substrate for gluconeogenesis, indicating an intricate balance of exacerbated opposite metabolic processes in glycemic regulation. These changes were associated with reduced metabolic adaptability on a network level in the sense that liver fat accumulation puts increasing demands on the liver to adaptively regulate metabolic responses to maintain basic liver functions. We propose that failure to meet excessive metabolic challenges coupled with reduced metabolic adaptability may lead to a vicious pathogenic cycle leading to the co-morbidities of NAFLD.