Browsing by Subject "ENHANCERS"

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  • Gusev, Alexander; Shi, Huwenbo; Kichaev, Gleb; Pomerantz, Mark; Li, Fugen; Long, Henry W.; Ingles, Sue A.; Kittles, Rick A.; Strom, Sara S.; Rybicki, Benjamin A.; Nemesure, Barbara; Isaacs, William B.; Zheng, Wei; Pettaway, Curtis A.; Yeboah, Edward D.; Tettey, Yao; Biritwum, Richard B.; Adjei, Andrew A.; Tay, Evelyn; Truelove, Ann; Niwa, Shelley; Chokkalingam, Anand P.; John, Esther M.; Murphy, Adam B.; Signorello, Lisa B.; Carpten, John; Leske, M. Cristina; Wu, Suh-Yuh; Hennis, Anslem J. M.; Neslund-Dudas, Christine; Hsing, Ann W.; Chu, Lisa; Goodman, Phyllis J.; Klein, Eric A.; Witte, John S.; Casey, Graham; Kaggwa, Sam; Cook, Michael B.; Stram, Daniel O.; Blot, William J.; Eeles, Rosalind A.; Easton, Douglas; Kote-Jarai, ZSofia; Al Olama, Ali Amin; Benlloch, Sara; Muir, Kenneth; Giles, Graham G.; Southey, Melissa C.; Fitzgerald, Liesel M.; Taari, Kimmo; PRACTICAL Consortium (2016)
    Although genome-wide association studies have identified over 100 risk loci that explain similar to 33% of familial risk for prostate cancer (PrCa), their functional effects on risk remain largely unknown. Here we use genotype data from 59,089 men of European and African American ancestries combined with cell-type-specific epigenetic data to build a genomic atlas of single-nucleotide polymorphism (SNP) heritability in PrCa. We find significant differences in heritability between variants in prostate-relevant epigenetic marks defined in normal versus tumour tissue as well as between tissue and cell lines. The majority of SNP heritability lies in regions marked by H3k27 acetylation in prostate adenoc7arcinoma cell line (LNCaP) or by DNaseI hypersensitive sites in cancer cell lines. We find a high degree of similarity between European and African American ancestries suggesting a similar genetic architecture from common variation underlying PrCa risk. Our findings showcase the power of integrating functional annotation with genetic data to understand the genetic basis of PrCa.
  • Palin, Kimmo; Pitkänen, Esa; Turunen, Mikko; Sahu, Biswajyoti; Pihlajamaa, Päivi; Kivioja, Teemu; Kaasinen, Eevi; Välimäki, Niko; Hänninen, Ulrika A.; Cajuso, Tatiana; Aavikko, Mervi; Tuupanen, Sari; Kilpivaara, Outi; van den Berg, Linda; Kondelin, Johanna; Tanskanen, Tomas; Katainen, Riku; Grau, Marta; Rauanheimo, Heli; Plaketti, Roosa-Maria; Taira, Aurora; Sulo, Päivi; Hartonen, Tuomo; Dave, Kashyap; Schmierer, Bernhard; Botla, Sandeep; Sokolova, Maria; Vähärautio, Anna; Gladysz, Kornelia; Ongen, Halit; Dermitzakis, Emmanouil; Bramsen, Jesper Bertram; Orntoft, Torben Falck; Andersen, Claus Lindbjerg; Ristimäki, Ari; Lepistö, Anna; Renkonen-Sinisalo, Laura; Mecklin, Jukka-Pekka; Taipale, Jussi; Aaltonen, Lauri A. (2018)
    Point mutations in cancer have been extensively studied but chromosomal gains and losses have been more challenging to interpret due to their unspecific nature. Here we examine high-resolution allelic imbalance (Al) landscape in 1699 colorectal cancers, 256 of which have been whole-genome sequenced (WGSed). The imbalances pinpoint 38 genes as plausible Al targets based on previous knowledge. Unbiased CRISPR-Cas9 knockout and activation screens identified in total 79 genes within Al peaks regulating cell growth. Genetic and functional data implicate loss of TP53 as a sufficient driver of Al. The WGS highlights an influence of copy number aberrations on the rate of detected somatic point mutations. Importantly, the data reveal several associations between Al target genes, suggesting a role for a network of lineage-determining transcription factors in colorectal tumorigenesis. Overall, the results unravel the contribution of Al in colorectal cancer and provide a plausible explanation why so few genes are commonly affected by point mutations in cancers.
  • Noguchi, Shuhei; Arakawa, Takahiro; Fukuda, Shiro; Furuno, Masaaki; Hasegawa, Akira; Hori, Fumi; Ishikawa-Kato, Sachi; Kaida, Kaoru; Kaiho, Ai; Kanamori-Katayama, Mutsumi; Kawashima, Tsugumi; Kojima, Miki; Kubosaki, Atsutaka; Manabe, Ri-ichiroh; Murata, Mitsuyoshi; Nagao-Sato, Sayaka; Nakazato, Kenichi; Ninomiya, Noriko; Nishiyori-Sueki, Hiromi; Noma, Shohei; Saijyo, Eri; Saka, Akiko; Sakai, Mizuho; Simon, Christophe; Suzuki, Naoko; Tagami, Michihira; Watanabe, Shoko; Yoshida, Shigehiro; Arner, Peter; Axton, Richard A.; Babina, Magda; Baillie, J. Kenneth; Barnett, Timothy C.; Beckhouse, Anthony G.; Blumenthal, Antje; Bodega, Beatrice; Bonetti, Alessandro; Briggs, James; Brombacher, Frank; Carlisle, Ailsa J.; Clevers, Hans C.; Davis, Carrie A.; Detmar, Michael; Dohi, Taeko; Edge, Albert S. B.; Edinger, Matthias; Ehrlund, Anna; Ekwall, Karl; Endoh, Mitsuhiro; Enomoto, Hideki; Eslami, Afsaneh; Fagiolini, Michela; Fairbairn, Lynsey; Farach-Carson, Mary C.; Faulkner, Geoffrey J.; Ferrai, Carmelo; Fisher, Malcolm E.; Forrester, Lesley M.; Fujita, Rie; Furusawa, Jun-ichi; Geijtenbeek, Teunis B.; Gingeras, Thomas; Goldowitz, Daniel; Guhl, Sven; Guler, Reto; Gustincich, Stefano; Ha, Thomas J.; Hamaguchi, Masahide; Hara, Mitsuko; Hasegawa, Yuki; Herlyn, Meenhard; Heutink, Peter; Hitchens, Kelly J.; Hume, David A.; Ikawa, Tomokatsu; Ishizu, Yuri; Kai, Chieko; Kawamoto, Hiroshi; Kawamura, Yuki I.; Kempfle, Judith S.; Kenna, Tony J.; Kere, Juha; Khachigian, Levon M.; Kitamura, Toshio; Klein, Sarah; Klinken, S. Peter; Knox, Alan J.; Kojima, Soichi; Koseki, Haruhiko; Koyasu, Shigeo; Lee, Weonju; Lennartsson, Andreas; Mackay-sim, Alan; Mejhert, Niklas; Mizuno, Yosuke; Morikawa, Hiromasa; Morimoto, Mitsuru; Moro, Kazuyo; Morris, Kelly J.; Motohashi, Hozumi; Mummery, Christine L.; Nakachi, Yutaka; Nakahara, Fumio; Nakamura, Toshiyuki; Nakamura, Yukio; Nozaki, Tadasuke; Ogishima, Soichi; Ohkura, Naganari; Ohno, Hiroshi; Ohshima, Mitsuhiro; Okada-Hatakeyama, Mariko; Okazaki, Yasushi; Orlando, Valerio; Ovchinnikov, Dmitry A.; Passier, Robert; Patrikakis, Margaret; Pombo, Ana; Pradhan-Bhatt, Swati; Qin, Xian-Yang; Rehli, Michael; Rizzu, Patrizia; Roy, Sugata; Sajantila, Antti; Sakaguchi, Shimon; Sato, Hiroki; Satoh, Hironori; Savvi, Suzana; Saxena, Alka; Schmidl, Christian; Schneider, Claudio; Schulze-Tanzil, Gundula G.; Schwegmann, Anita; Sheng, Guojun; Shin, Jay W.; Sugiyama, Daisuke; Sugiyama, Takaaki; Summers, Kim M.; Takahashi, Naoko; Takai, Jun; Tanaka, Hiroshi; Tatsukawa, Hideki; Tomoiu, Andru; Toyoda, Hiroo; van de Wetering, Marc; van den Berg, Linda M.; Verardo, Roberto; Vijayan, Dipti; Wells, Christine A.; Winteringham, Louise N.; Wolvetang, Ernst; Yamaguchi, Yoko; Yamamoto, Masayuki; Yanagi-Mizuochi, Chiyo; Yoneda, Misako; Yonekura, Yohei; Zhang, Peter G.; Zucchelli, Silvia; Abugessaisa, Imad; Arner, Erik; Harshbarger, Jayson; Kondo, Atsushi; Lassmann, Timo; Lizio, Marina; Sahin, Serkan; Sengstag, Thierry; Severin, Jessica; Shimoji, Hisashi; Suzuki, Masanori; Suzuki, Harukazu; Kawai, Jun; Kondo, Naoto; Itoh, Masayoshi; Daub, Carsten O.; Kasukawa, Takeya; Kawaji, Hideya; Carninci, Piero; Forrest, Alistair R. R.; Hayashizaki, Yoshihide (2017)
    In the FANTOM5 project, transcription initiation events across the human and mouse genomes were mapped at a single base-pair resolution and their frequencies were monitored by CAGE (Cap Analysis of Gene Expression) coupled with single-molecule sequencing. Approximately three thousands of samples, consisting of a variety of primary cells, tissues, cell lines, and time series samples during cell activation and development, were subjected to a uniform pipeline of CAGE data production. The analysis pipeline started by measuring RNA extracts to assess their quality, and continued to CAGE library production by using a robotic or a manual workflow, single molecule sequencing, and computational processing to generate frequencies of transcription initiation. Resulting data represents the consequence of transcriptional regulation in each analyzed state of mammalian cells. Non-overlapping peaks over the CAGE profiles, approximately 200,000 and 150,000 peaks for the human and mouse genomes, were identified and annotated to provide precise location of known promoters as well as novel ones, and to quantify their activities.
  • Miroshnikova, Yekaterina A; Cohen, Idan; Ezhkova, Elena; Wickström, Sara A (2019)
    The skin epidermis is a constantly renewing stratified epithelium that provides essential protective barrier functions throughout life. Epidermal stratification is governed by a step-wise differentiation program that requires precise spatiotemporal control of gene expression. How epidermal self-renewal and differentiation are regulated remains a fundamental open question. Cell-intrinsic and cell-extrinsic mechanisms that modify chromatin structure and interactions have been identified as key regulators of epidermal differentiation and stratification. Here, we will review the recent advances in our understanding of how chromatin modifiers, tissue-specific transcription factors, and force-induced nuclear remodeling processes function to shape chromatin and to control epidermal tissue development and homeostasis.
  • Darabi, Hatef; Beesley, Jonathan; Droit, Arnaud; Kar, Siddhartha; Nord, Silje; Marjaneh, Mahdi Moradi; Soucy, Penny; Michailidou, Kyriaki; Ghoussaini, Maya; Wahl, Hanna Fues; Bolla, Manjeet K.; Wang, Qin; Dennis, Joe; Alonso, M. Rosario; Andrulis, Irene L.; Anton-Culver, Hoda; Arndt, Volker; Beckmann, Matthias W.; Benitez, Javier; Bogdanova, Natalia V.; Bojesen, Stig E.; Brauch, Hiltrud; Brenner, Hermann; Broeks, Annegien; Bruening, Thomas; Burwinkel, Barbara; Chang-Claude, Jenny; Choi, Ji-Yeob; Conroy, Don M.; Couch, Fergus J.; Cox, Angela; Cross, Simon S.; Czene, Kamila; Devilee, Peter; Doerk, Thilo; Easton, Douglas F.; Fasching, Peter A.; Figueroa, Jonine; Fletcher, Olivia; Flyger, Henrik; Galle, Eva; Garcia-Closas, Montserrat; Giles, Graham G.; Goldberg, Mark S.; Gonzalez-Neira, Anna; Guenel, Pascal; Haiman, Christopher A.; Hallberg, Emily; Hamann, Ute; Hartman, Mikael; Hollestelle, Antoinette; Hopper, John L.; Ito, Hidemi; Jakubowska, Anna; Johnson, Nichola; Kang, Daehee; Khan, Sofia; Kosma, Veli-Matti; Kriege, Mieke; Kristensen, Vessela; Lambrechts, Diether; Le Marchand, Loic; Lee, Soo Chin; Lindblom, Annika; Lophatananon, Artitaya; Lubinski, Jan; Mannermaa, Arto; Manoukian, Siranoush; Margolin, Sara; Matsuo, Keitaro; Mayes, Rebecca; Mckay, James; Meindl, Alfons; Milne, Roger L.; Muir, Kenneth; Neuhausen, Susan L.; Nevanlinna, Heli; Olswold, Curtis; Orr, Nick; Peterlongo, Paolo; Pita, Guillermo; Pylkaes, Katri; Rudolph, Anja; Sangrajrang, Suleeporn; Sawyer, Elinor J.; Schmidt, Marjanka K.; Schmutzler, Rita K.; Seynaeve, Caroline; Shah, Mitul; Shen, Chen-Yang; Shu, Xiao-Ou; Southey, Melissa C.; Stram, Daniel O.; Surowy, Harald; Swerdlow, Anthony; Teo, Soo H.; Tessier, Daniel C.; Tomlinson, Ian; Torres, Diana; Truong, Therese; Vachon, Celine M.; Vincent, Daniel; Winqvist, Robert; Wu, Anna H.; Wu, Pei-Ei; Yip, Cheng Har; Zheng, Wei; Pharoah, Paul D. P.; Hall, Per; Edwards, Stacey L.; Simard, Jacques; French, Juliet D.; Chenevix-Trench, Georgia; Dunning, Alison M. (2016)
    Genome-wide association studies have found SNPs at 17q22 to be associated with breast cancer risk. To identify potential causal variants related to breast cancer risk, we performed a high resolution fine-mapping analysis that involved genotyping 517 SNPs using a custom Illumina iSelect array (iCOGS) followed by imputation of genotypes for 3,134 SNPs in more than 89,000 participants of European ancestry from the Breast Cancer Association Consortium (BCAC). We identified 28 highly correlated common variants, in a 53 Kb region spanning two introns of the STXBP4 gene, that are strong candidates for driving breast cancer risk (lead SNP rs2787486 (OR = 0.92; CI 0.90-0.94; P = 8.96 x 10(-15))) and are correlated with two previously reported risk-associated variants at this locus, SNPs rs6504950 (OR = 0.94, P = 2.04 x 10-09, r(2) = 0.73 with lead SNP) and rs1156287 (OR = 0.93, P = 3.41 x 10(-11), r(2) = 0.83 with lead SNP). Analyses indicate only one causal SNP in the region and several enhancer elements targeting STXBP4 are located within the 53 kb association signal. Expression studies in breast tumor tissues found SNP rs2787486 to be associated with increased STXBP4 expression, suggesting this may be a target gene of this locus.
  • Verta, Jukka-Pekka; Barton, Henry Juho; Pritchard, Victoria; Primmer, Craig (2021)
    Whole-genome duplications (WGD) have been considered as springboards that potentiate lineage diversification through increasing functional redundancy. Divergence in gene regulatory elements is a central mechanism for evolutionary diversification, yet the patterns and processes governing regulatory divergence following events that lead to massive functional redundancy, such as WGD, remain largely unknown. We studied the patterns of divergence and strength of natural selection on regulatory elements in the Atlantic salmon (Salmo salar) genome, which has undergone WGD 100–80 Ma. Using ChIPmentation, we first show that H3K27ac, a histone modification typical to enhancers and promoters, is associated with genic regions, tissue-specific transcription factor binding motifs, and with gene transcription levels in immature testes. Divergence in transcription between duplicated genes from WGD (ohnologs) correlated with difference in the number of proximal regulatory elements, but not with promoter elements, suggesting that functional divergence between ohnologs after WGD is mainly driven by enhancers. By comparing H3K27ac regions between duplicated genome blocks, we further show that a longer polyploid state post-WGD has constrained regulatory divergence. Patterns of genetic diversity across natural populations inferred from resequencing indicate that recent evolutionary pressures on H3K27ac regions are dominated by largely neutral evolution. In sum, our results suggest that post-WGD functional redundancy in regulatory elements continues to have an impact on the evolution of the salmon genome, promoting largely neutral evolution of regulatory elements despite their association with transcription levels. These results highlight a case where genome-wide regulatory evolution following an ancient WGD is dominated by genetic drift.
  • GC-HBOC Study Collaborators; GEMO Study Collaborators; EMBRACE Collaborators; HEBON Investigators; BCFR Investigators; ABCTB Investigators; Ferreira, Manuel A.; Gamazon, Eric R.; Aittomäki, Kristiina; Blomqvist, Carl; Kiiski, Johanna I.; Nevanlinna, Heli (2019)
    Genome-wide association studies (GWAS) have identified more than 170 breast cancer susceptibility loci. Here we hypothesize that some risk-associated variants might act in non-breast tissues, specifically adipose tissue and immune cells from blood and spleen. Using expression quantitative trait loci (eQTL) reported in these tissues, we identify 26 previously unreported, likely target genes of overall breast cancer risk variants, and 17 for estrogen receptor (ER)-negative breast cancer, several with a known immune function. We determine the directional effect of gene expression on disease risk measured based on single and multiple eQTL. In addition, using a gene-based test of association that considers eQTL from multiple tissues, we identify seven (and four) regions with variants associated with overall (and ER-negative) breast cancer risk, which were not reported in previous GWAS. Further investigation of the function of the implicated genes in breast and immune cells may provide insights into the etiology of breast cancer.
  • Khanshour, Anas M.; Kou, Ikuyo; Fan, Yanhui; Einarsdottir, Elisabet; Makki, Nadja; Kidane, Yared H.; Kere, Juha; Grauers, Anna; Johnson, Todd A.; Paria, Nandina; Patel, Chandreshkumar; Singhania, Richa; Kamiya, Nobuhiro; Takeda, Kazuki; Otomo, Nao; Watanabe, Kota; Luk, Keith D. K.; Cheung, Kenneth M. C.; Herring, John A.; Rios, Jonathan J.; Ahituv, Nadav; Gerdhem, Paul; Gurnett, Christina A.; Song, You-Qiang; Ikegawa, Shiro; Wise, Carol A. (2018)
    Adolescent idiopathic scoliosis (AIS) is the most common musculoskeletal disorder of childhood development. The genetic architecture of AIS is complex, and the great majority of risk factors are undiscovered. To identify new AIS susceptibility loci, we conducted the first genome-wide meta-analysis of AIS genome-wide association studies, including 7956 cases and 88 459 controls from 3 ancestral groups. Three novel loci that surpassed genome-wide significance were uncovered in intragenic regions of the CDH13 (P-value_rs4513093 = 1.7E-15), ABO (P-value_ rs687621 = 7.3E-10) and SOX6 (P-value_ rs1455114 = 2.98E-08) genes. Restricting the analysis to females improved the associations at multiple loci, most notably with variants within CDH13 despite the reduction in sample size. Genome-wide gene-functional enrichment analysis identified significant perturbation of pathways involving cartilage and connective tissue development. Expression of both SOX6 and CDH13 was detected in cartilage chondrocytes and chromatin immunoprecipitation sequencing experiments in that tissue revealed multiple HeK27ac-positive peaks overlapping associated loci. Our results further define the genetic architecture of AIS and highlight the importance of vertebral cartilage development in its pathogenesis.
  • Weltner, Jere; Balboa, Diego; Katayama, Shintaro; Bespalov, Maxim; Krjutskov, Kaarel; Jouhilahti, Eeva-Mari; Trokovic, Ras; Kere, Juha; Otonkoski, Timo (2018)
    CRISPR-Cas9-based gene activation (CRISPRa) is an attractive tool for cellular reprogramming applications due to its high multiplexing capacity and direct targeting of endogenous loci. Here we present the reprogramming of primary human skin fibroblasts into induced pluripotent stem cells (iPSCs) using CRISPRa, targeting endogenous OCT4, SOX2, KLF4, MYC, and LIN28A promoters. The low basal reprogramming efficiency can be improved by an order of magnitude by additionally targeting a conserved Alu-motif enriched near genes involved in embryo genome activation (EEA-motif). This effect is mediated in part by more efficient activation of NANOG and REX1. These data demonstrate that human somatic cells can be reprogrammed into iPSCs using only CRISPRa. Furthermore, the results unravel the involvement of EEA-motif-associated mechanisms in cellular reprogramming.
  • Zeng, Chenjie; Guo, Xingyi; Long, Jirong; Kuchenbaecker, Karoline B.; Droit, Arnaud; Michailidou, Kyriaki; Ghoussaini, Maya; Kar, Siddhartha; Freeman, Adam; Hopper, John L.; Milne, Roger L.; Bolla, Manjeet K.; Wang, Qin; Dennis, Joe; Agata, Simona; Ahmed, Shahana; Aittomäki, Kristiina; Andrulis, Irene L.; Anton-Culver, Hoda; Antonenkova, Natalia N.; Arason, Adalgeir; Arndt, Volker; Arun, Banu K.; Arver, Brita; Bacot, Francois; Barrowdale, Daniel; Baynes, Caroline; Beeghly-Fadiel, Alicia; Benitez, Javier; Bermisheva, Marina; Blomqvist, Carl; Blot, William J.; Bogdanova, Natalia V.; Bojesen, Stig E.; Bonanni, Bernardo; Borresen-Dale, Anne-Lise; Brand, Judith S.; Brauch, Hiltrud; Brennan, Paul; Brenner, Hermann; Broeks, Annegien; Bruening, Thomas; Burwinkel, Barbara; Buys, Saundra S.; Cai, Qiuyin; Caldes, Trinidad; Campbell, Ian; Carpenter, Jane; Khan, Sofia; Nevanlinna, Heli; EMBRACE; GEMO Study Collaborators; HEBON; KConFab; AOCS Investigators (2016)
    Background: Multiple recent genome-wide association studies (GWAS) have identified a single nucleotide polymorphism (SNP), rs10771399, at 12p11 that is associated with breast cancer risk. Method: We performed a fine-scale mapping study of a 700 kb region including 441 genotyped and more than 1300 imputed genetic variants in 48,155 cases and 43,612 controls of European descent, 6269 cases and 6624 controls of East Asian descent and 1116 cases and 932 controls of African descent in the Breast Cancer Association Consortium (BCAC; http://bcac.ccge.medschl.cam.ac.uk/), and in 15,252 BRCA1 mutation carriers in the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA). Stepwise regression analyses were performed to identify independent association signals. Data from the Encyclopedia of DNA Elements project (ENCODE) and the Cancer Genome Atlas (TCGA) were used for functional annotation. Results: Analysis of data from European descendants found evidence for four independent association signals at 12p11, represented by rs7297051 (odds ratio (OR) = 1.09, 95 % confidence interval (CI) = 1.06-1.12; P = 3 x 10(-9)), rs805510 (OR = 1.08, 95 % CI = 1.04-1.12, P = 2 x 10(-5)), and rs1871152 (OR = 1.04, 95 % CI = 1.02-1.06; P = 2 x 10(-4)) identified in the general populations, and rs113824616 (P = 7 x 10(-5)) identified in the meta-analysis of BCAC ER-negative cases and BRCA1 mutation carriers. SNPs rs7297051, rs805510 and rs113824616 were also associated with breast cancer risk at P <0.05 in East Asians, but none of the associations were statistically significant in African descendants. Multiple candidate functional variants are located in putative enhancer sequences. Chromatin interaction data suggested that PTHLH was the likely target gene of these enhancers. Of the six variants with the strongest evidence of potential functionality, rs11049453 was statistically significantly associated with the expression of PTHLH and its nearby gene CCDC91 at P <0.05. Conclusion: This study identified four independent association signals at 12p11 and revealed potentially functional variants, providing additional insights into the underlying biological mechanism(s) for the association observed between variants at 12p11 and breast cancer risk.
  • Garske, Kristina M.; Comenho, Caroline; Pan, David Z.; Alvarez, Marcus; Mohlke, Karen; Laakso, Markku; Pietiläinen, Kirsi H.; Pajukanta, Päivi (2022)
    Obesity perturbs central functions of human adipose tissue, centred on differentiation of preadipocytes to adipocytes, i.e., adipogenesis. The large environmental component of obesity makes it important to elucidate epigenetic regulatory factors impacting adipogenesis. Promoter Capture Hi-C (pCHi-C) has been used to identify chromosomal interactions between promoters and associated regulatory elements. However, long range interactions (LRIs) greater than 1 Mb are often filtered out of pCHi-C datasets, due to technical challenges and their low prevalence. To elucidate the unknown role of LRIs in adipogenesis, we investigated preadipocyte differentiation to adipocytes using pCHi-C and bulk and single nucleus RNA-seq data. We first show that LRIs are reproducible between biological replicates, and they increase >2-fold in frequency across adipogenesis. We further demonstrate that genomic loci containing LRIs are more epigenetically repressed than regions without LRIs, corresponding to lower gene expression in the LRI regions. Accordingly, as preadipocytes differentiate into adipocytes, LRI regions are more likely to contain repressed preadipocyte marker genes; whereas these same LRI regions are depleted of actively expressed adipocyte marker genes. Finally, we show that LRIs can be used to restrict multiple testing of the long-range cis-eQTL analysis to identify variants that regulate genes via LRIs. We exemplify this by identifying a putative long range cis regulatory mechanism at the LYPLAL1/TGFB2 obesity locus. In summary, we identify LRIs that mark repressed regions of the genome, and these interactions increase across adipogenesis, pinpointing developmental regions that need to be repressed in a cell-type specific way for adipogenesis to proceed.
  • Taipale, M.; Jakkula, E.; Kamarainen, O. -P; Gao, P.; Skarp, S.; Barral, S.; Kiviranta, I.; Kroger, H.; Ott, J.; Wei, G. -H.; Ala-Kokko, L.; Mannikko, M. (2016)
    Objective: The aim of the study was to identify genetic variants predisposing to primary hip and knee osteoarthritis (OA) in a sample of Finnish families. Methods: Genome wide analysis was performed using 15 independent families (279 individuals) originating from Central Finland identified as having multiple individuals with primary hip and/or knee OA. Targeted re-sequencing was performed for three samples from one 33-member, four-generation family contributing most significantly to the LOD score. In addition, exome sequencing was performed in three family members from the same family. Results: Genome wide linkage analysis identified a susceptibility locus on chromosome 2q21 with a multipoint LOD score of 3.91. Targeted re-sequencing and subsequent linkage analysis revealed a susceptibility insertion variant rs11446594. It locates in a predicted strong enhancer element region with maximum LOD score 3.42 under dominant model of inheritance. Insertion creates a recognition sequence for ELF3 and HMGA1 transcription factors. Their DNA-binding affinity is highly increased in the presence of A-allele compared to wild type null allele. Conclusion: A potentially novel functional OA susceptibility variant was identified by targeted resequencing. This variant locates in a predicted regulatory site and creates a recognition sequence for ELF3 and HMGA1 transcription factors that are predicted to play a significant role in articular cartilage homeostasis. (C) 2015 The Authors. Published by Elsevier Ltd and Osteoarthritis Research Society International.