Artifacts in Nuclear Medicine with Identifying and resolving artifacts.
YEAR IN REVIEW - Genetics, Genomics, Epigenetics
1. YEAR IN REVIEW
Genetics, Genomics, Epigenetics
Louise Reynard
Newcastle University, UK
louise.reynard@newcastle.ac.uk
2. Louise Reynard, PhD
Lecturer
Newcastle University, Newcastle upon Tyne, UK
Disclosure Information
I have no financial relationships with commercial interests to disclose
AND
My presentation does not include discussion of off-label or investigational use.
3. Systematic Literature Review
Year in Review: Genetics, Genomics, Epigenetics
From 26/04/2018 to 23/04/2019 identified 636 papers using the terms
OSTEOARTHRITIS or CARTILAGE
and
GENETICS/SNP/GENOMICS/RNA sequencing/TRANSCRIPTOMICS/EPIGENETICS/
EPIGENOMICS/NON-CODING RNA/miRNA/lncRNA/HISTONE/DNA METHYLATION
In this review, I will focus on
- Identification of new OA genetic loci from genome-wide association studies
- New publically available databases and datasets that will aid functional studies of
- Genomic techniques used for the first time in cartilage
(e.g. single-cell RNAseq, ATACseq, histone ChIPseq)
OA risk loci and OA-associated epigenetic changes
5. 57 new OA genetic risk loci were identified this year
Year in Review: Genetics, Genomics, Epigenetics GENETICS
Total loci
Novel loci
>650,000 Icelandic +UK individuals from
UKBB + deCODE cohorts
PMID:30374069
>450,000 UK individuals from UK
Biobank + arcOGEN cohorts
PMID:30664745
joint
Together, these studies almost tripled the number of OA risk loci from 33 to 90
Two large scale genome-wide association studies for OA were published
6. Replication of existing loci including GDF5, PTHLH, ASTN2, RUNX2, SMAD3 and ALDH1A2
UKBB + deCODE study
Meta-analysis for OA hip or OA knee
Also looked at association with height*
UK Biobank + arcOGEN study
Meta-analysis of OA hip, OA knee, OA
hip&/or knee and OA any site
DPEP1
CRADD
SPTBN2
COL11A1
HDAC9
SMO
FAM101A*
COL11A1*
LTBP1* LTBP3
COL27A1
GSDMC*
IL11*
NACA2
SBNO1*
LMX1B
TNC
NFAT5/WWP2*
HFE/HIST1H2BC
ANP32E
RABGAP1L
COLGALT2
KIF26B
SDPR
RAPH1
MST1R
FAM53
RAB28
ANAPC4
SLC39A8
AP3B1
FGFR18
COL11A2
CDC5L
BMP5
DYNCIL1
PPR1R3B
mir8068
DCDC5
TSKU
LRIG3
CPSF6
linc00936
BCL7AUSP8
CSK
NF1
SMG1
MAPT
SOX9
TMEM241
SLC44A2
TGFB1
ERG
SCUBE1
Year in Review: Genetics, Genomics, Epigenetics GENETICS
57 new OA genetic risk loci were identified this year
4 unique loci 12 shared loci 41 unique loci
* Loci also
associated
with height
at p<5x10-8
7. • 10 hip shape modules from DXA scans of 15,973
• Loci overlap established PTHLH & ASTN2 and
novel OA loci near SOX9
1st meta-analysis GWAS for hip shape
identified 12 loci at p< 5x10-8
SOX9
rs2158915
PTHLH
rs10743612
ASTN2
rs1885285
PMID:30320955
New variants for hip shape and DHH co-localise with OA loci
Genetic association between OA, hip
shape and DDH suggests that OA genetic
risk is established during development
GWASs of hip shape and developmental dysplasia of the hip (DDH)
GDF5 OA SNP rs143384 is also
associated with DDH genetic risk
• GDF5 rs143384 SNP p=3.55x10-22, OR 1.44
PMID:30273415
Gdf5 null mice have
abnormal hips incl. smaller
femoral heads and necks
GDF5 is required for normal hip
morphology in mice
PMID:30388100
+/- -/-
Year in Review: Genetics, Genomics, Epigenetics GENETICS
8. In 2019-2020, the number of OA loci will increase again….
Year in Review: Genetics, Genomics, Epigenetics GENETICS
Meta-analysis of 18 GWAS cohorts by the Genetics of Osteoarthritis consortium*
• 1st trans-ethnic GWAS meta-analysis for OA and includes 179,305 cases and >650,000
controls from Europe, Japan, Hong Kong and USA
* Personal communication from Cindy Boer and Joyce van Meurs
arcoGEN
ARGO study
Geisinger
HKDDDC
HUNT study
TwinsUK
Norwegian Arthroplasty Register
Japanese OA cohort
Leiden Longevity Study
Nurses’ Health Study
Rotterdam study
UKBiobank
CHECK
deCODE
EGCUT
GARP
RAAK
UKHLS
https://www.genetics-osteoarthritis.com/
• Phenotypes include hip, knee, spine, hand, thumb, finger OA and all OA
• ~70 novel OA loci have been identified*
• Polygenic risk score and heritability estimate analyses are now being performed*
>2 fold increase in number of cases
than previous meta-analyses
10. Year in Review: Genetics, Genomics, Epigenetics GENOMICS
RNAseq detected SNPs with allelic imbalance (AI) in OA cartilage
‘ .. data set for researchers in the OA research field to probe for disease-relevant genetic
variation that affects gene expression in pivotal disease-affected tissue’
Transcriptome-wide quantification of SNP allelic output in heterozygotes
A
C
AAA
AAA
AAA
Allelic balance
AAA
AAA
AAA
A
C
AAA
AAA
AAA
AAA
AAA
Allelic imbalance (AI)
PMID:30298554
• AI assessed in 42 preserved and 5 lesioned OA cartilage samples
• 2,070 SNPs that consistently marked AI of 1,031 unique genes (Supplementary Table S3)
• 11 previously identified OA/mJSW risk genes contained SNPs that marked AI in OA cartilage
(including ALDH1A2, MGP, MAP2K6, PLEC and COL11A1)
• 4/57 new OA loci contain transcript SNPs with AI in cartilage
(LTBP1, TNC, SBNO1/CDK2AP1 and SLC44A2)
11. SkeletalVis is a new database for skeletal transcriptomics data
SkeletalVis transcriptomic data portal http://phenome.manchester.ac.uk/
Year in Review: Genetics, Genomics, Epigenetics GENOMICS
‘..will be useful for prioritization of differentially expressed genes…. and for initial
functional characterization of novel disease-associated genes identified through GWAS..’
Database of ~300 consistently analysed
cross-species transcriptomic experiments
from skeletal tissues (including cartilage,
bone, synovium, meniscus & blood)
PMID:30481257
12. The first single-cell RNAseq analysis of cartilage identified
seven molecular subgroups of OA chondrocytes
Analysis of 1464 chondrocytes from the tibial plateau of 10 OA knee patients
Year in Review: Genetics, Genomics, Epigenetics GENOMICS
‘reveal the overall pattern of transcriptome states during OA pathogenesis at the single-cell level’
PMID:30026257
- Identified 7 chondrocyte clusters and their markers genes
- These included 3 novel populations; effector (ECs), regulatory
(RegCs) and homeostatic (HomCs) chondrocytes
14. ‘..aimed to define a transcriptome of
lncRNAs in OA cartilage, specifically
comparing the lincRNA
transcriptome of knee and hip cartilage.’
• 1692 hip & 648 knee lncRNAs TPM>1
• 198 DE hip & 93 DE knee lncRNAs e.g. MEG3
PMID:30611906
Two RNAseq studies systematically identified cartilage ncRNAs
Genome-wide expression analysis of miRNAs and lncRNAs in OA cartilage
• Integrated mRNA and miRNA RNAseq in
paired preserved and lesioned OA cartilage
‘our miRNA interactome represents a
comprehensive legacy to directly probe
miRNAs of interest with their likely
downstream signalling pathways..’
• 142 miRNAs & 2387 DE mRNAs at FDR≤0.05
• 62 miRNAs and 238 mRNAs formed the first
comprehensive OA miRNA interactome
PMID:30504444
Year in Review: Genetics, Genomics, Epigenetics EPIGENETICS
DE lncRNAs
15. ATACseq identifed open chromatin regions in OA knee cartilage
Year in Review: Genetics, Genomics, Epigenetics EPIGENETICS*assay for transposase-accessible chromatin using sequencing
ATACseq* is a genome-wide method to identify open chromatin regions
ATACseq is fast, sensitive, requires few cells and is becoming an essential epigenetic tool for
identifying transcriptional regulatory regions including enhancers and promoters
PMID:24097267
50,000 cells from paired damaged and intact regions of OA knee cartilage from 8 OA patients
PMID:30341348
109,125 open chromatin regions were identified in OA knee cartilage
16. ATACseq identifed open chromatin regions in OA knee cartilage
*based on Roadmap annotations
• 71.1% peaks were annotated as enhancers*
109,125 open chromatin regions were identified in OA knee cartilage
PMID:30341348
unknown
(12%)
promoter
(16.9%%)
enhancer
(71.1%)
More open
in intact
(2.6%)
More open
in damaged
(1.4%)
Unaltered
96%
Open chromatin characteristics
‘..our study provides an accessible chromatin landscape of cartilage tissue for better
interpretation of other genetic and epigenomic data relevant to OA..’
• Several previously reported OA SNPs overlap OA knee ATACseq peaks
(GDF5, ALDH1A2, DOT1L, MCF2L, GLIS3 and MGP loci)
• SNPs within 29/57 new OA loci overlap ATACseq peaks
(including LTBP1, LTBP3, GSDMC, SBNO1, COL11A1, TNC and SLC44A2)
Year in Review: Genetics, Genomics, Epigenetics EPIGENETICS
17. Histone ChIPseq identified promoters and enhancer regions in
fetal and adult articular cartilage
Year in Review: Genetics, Genomics, Epigenetics EPIGENETICS
ChIPseq of 10,000 chondrocytes for H3K4me1, H3K4me3, H3K27Ac & H3K27me3
• Histone ChIPseq of 17 week human fetal & adult chondrocytes and hESC-derived chondrocytes
• 12 chromatin states identified including inactive, poised and active enhancers
(raw ChIPseq data available to download at GSE111850)
• RNAseq analysis of 4 in vivo & 2 in vitro stages of chondrocyte
differentiation, and 17 week fetal bone, muscle, ligament and
tendon tissues (TPM data available as an excel file at GSE106292)
PMID:30194383
18. Acknowledgements
Thank you to Cindy Boer and Joyce van Meurs for sharing unpublished GWAS data
from the GO consortium meta-analysis
Editor's Notes
Total of 4134 cases, 5781 ctls
Three years ago Joyce van Meurs gave the year in review and at the end of her presentation, she said that OA genetics was in the trough of dillusionment and would hopefully enter the plateau of productiveity. However, we have entered a golden age of identification of OA genetic loci, which will continue with the GO consortium.
Use of emerging genomic methods in cartilage and databases and datasets that will aid future functional studies of genetic and epigenetic OA loci
Analysed ctl hip, OA hip, preserved knee and lesioned knee cartilage
alternative advanced method for MNase-seq (sequencing of micrococcal nuclease sensitive sites), FAIRE-seq and DNAse-seq (1). ATAC-seq is an emerging technique that’s gaining popularity among researchers from diverse backgrounds as it aids in a fast and sensitive analysis of the epigenome compared to DNase-seq or MNase-seq (2,3,4). The applications of ATAC-seq in enhancing the functional genomics field have been explored in recent literature in hopes to understand epigenetic regulation in the context of disease development and cell differentiation. Indeed, ATAC-seq is becoming an essential tool in epigenetics and genome-regulation research and a standard part of epigenetic analysis. It has been successfully adapted to efficiently identify open chromatin and identify regulatory elements across the genome. ATAC-seq identifies accessible DNA regions by probing open chromatin with hyperactive mutant Tn5 transposase that inserts sequencing adapters into open regions of the genome. The mutant Tn5 transposase excises any sufficiently long DNA in a process called tagmentation: the simultaneous fragmentation and tagging of DNA performed by Tn5 transposase pre-loaded with sequencing adaptors. The tagged DNA fragments are then purified, amplified by PCR and sent for sequencing. Sequencing reads can then be used to infer regions of increased accessibility as well as to map regions of transcription-factor binding sites and nucleosome positions. The key element of the ATAC-seq procedure is the action of the transposase Tn5 on the genomic DNA of the sample. Transposases are enzymes catalyzing the movement of transposons to other parts in the genome (5). While naturally occurring transposases have a low level of activity, ATAC-seq employs a mutated hyperactive transposase(5). The most common use of ATAC-Seq is in nucleosome mapping experiments (3). To this end, ATAC-Seq analysis has been used to investigate a number of chromatin-related signatures such as the genome-wide chromatin accessibility landscape in human cancer (6) and enhancer prediction. The utility of high-resolution enhancer mapping ranges from studying the evolutionary divergence of enhancer usage (e.g. between chimps and humans) during development (7) and uncovering a lineage-specific enhancer map used during blood cell differentiation (8). Most recently, ATAC-Seq has been used to reveal a genome-wide decrease in chromatin accessibility specifically related to macular degeneration (vision loss) (9).
alternative advanced method for MNase-seq (sequencing of micrococcal nuclease sensitive sites), FAIRE-seq and DNAse-seq (1). ATAC-seq is an emerging technique that’s gaining popularity among researchers from diverse backgrounds as it aids in a fast and sensitive analysis of the epigenome compared to DNase-seq or MNase-seq (2,3,4). The applications of ATAC-seq in enhancing the functional genomics field have been explored in recent literature in hopes to understand epigenetic regulation in the context of disease development and cell differentiation. Indeed, ATAC-seq is becoming an essential tool in epigenetics and genome-regulation research and a standard part of epigenetic analysis. It has been successfully adapted to efficiently identify open chromatin and identify regulatory elements across the genome. ATAC-seq identifies accessible DNA regions by probing open chromatin with hyperactive mutant Tn5 transposase that inserts sequencing adapters into open regions of the genome. The mutant Tn5 transposase excises any sufficiently long DNA in a process called tagmentation: the simultaneous fragmentation and tagging of DNA performed by Tn5 transposase pre-loaded with sequencing adaptors. The tagged DNA fragments are then purified, amplified by PCR and sent for sequencing. Sequencing reads can then be used to infer regions of increased accessibility as well as to map regions of transcription-factor binding sites and nucleosome positions. The key element of the ATAC-seq procedure is the action of the transposase Tn5 on the genomic DNA of the sample. Transposases are enzymes catalyzing the movement of transposons to other parts in the genome (5). While naturally occurring transposases have a low level of activity, ATAC-seq employs a mutated hyperactive transposase(5). The most common use of ATAC-Seq is in nucleosome mapping experiments (3). To this end, ATAC-Seq analysis has been used to investigate a number of chromatin-related signatures such as the genome-wide chromatin accessibility landscape in human cancer (6) and enhancer prediction. The utility of high-resolution enhancer mapping ranges from studying the evolutionary divergence of enhancer usage (e.g. between chimps and humans) during development (7) and uncovering a lineage-specific enhancer map used during blood cell differentiation (8). Most recently, ATAC-Seq has been used to reveal a genome-wide decrease in chromatin accessibility specifically related to macular degeneration (vision loss) (9).