In silico analyses of metagenomes from human atherosclerotic plaque samples.
BACKGROUND
Through several observational and mechanistic studies, microbial infection is known to promote cardiovascular disease. Direct infection of the vessel wall, along with the cardiovascular risk factors, is hypothesized to play a key role in the atherogenesis by promoting an inflammatory response leading to endothelial dysfunction and generating a proatherogenic and prothrombotic environment ultimately leading to clinical manifestations of cardiovascular disease, e.g., acute myocardial infarction or stroke. There are many reports of microbial DNA isolation and even a few studies of viable microbes isolated from human atherosclerotic vessels. However, high-resolution investigation of microbial infectious agents from human vessels that may contribute to atherosclerosis is very limited. In spite of the progress in recent sequencing technologies, analyzing host-associated metagenomes remain a challenge.


RESULTS
To investigate microbiome diversity within human atherosclerotic tissue samples, we employed high-throughput metagenomic analysis on: (1) atherosclerotic plaques obtained from a group of patients who underwent endarterectomy due to recent transient cerebral ischemia or stroke. (2) Presumed stabile atherosclerotic plaques obtained from autopsy from a control group of patients who all died from causes not related to cardiovascular disease. Our data provides evidence that suggest a wide range of microbial agents in atherosclerotic plaques, and an intriguing new observation that shows these microbiota displayed differences between symptomatic and asymptomatic plaques as judged from the taxonomic profiles in these two groups of patients. Additionally, functional annotations reveal significant differences in basic metabolic and disease pathway signatures between these groups.


CONCLUSIONS
We demonstrate the feasibility of novel high-resolution techniques aimed at identification and characterization of microbial genomes in human atherosclerotic tissue samples. Our analysis suggests that distinct groups of microbial agents might play different roles during the development of atherosclerotic plaques. These findings may serve as a reference point for future studies in this area of research.
Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore. suparna.mitra@ifr.ac.uk.|Norwich Medical School, University of East Anglia, Norwich, UK. suparna.mitra@ifr.ac.uk.|Institute of Food Research, Norwich Research Park, Norwich, UK. suparna.mitra@ifr.ac.uk.
Suparna
S
Mitra
Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore. danielamoses@pmail.ntu.edu.sg.
Daniela I
DI
Drautz-Moses
Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark. malhede@sund.ku.dk.
Morten
M
Alhede
Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore. MYAT@ntu.edu.sg.
Myat T
MT
Maw
Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore. Liu_Yang@ntu.edu.sg.
Yang
Y
Liu
Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore. RPurbojati@ntu.edu.sg.
Rikky W
RW
Purbojati
Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore. ZHYap@ntu.edu.sg.
Zhei H
ZH
Yap
Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore. k.kushwaha@ntu.edu.sg.
Kavita K
KK
Kushwaha
The Department of Forensic Medicine, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark. Alexandra.Gheorghe@sund.ku.dk.
Alexandra G
AG
Gheorghe
Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark. tbjarnsholt@sund.ku.dk.|Department of Clinical Microbiology, Rigshospitalet, Copenhagen, Denmark. tbjarnsholt@sund.ku.dk.
Thomas
T
Bjarnsholt
Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark. gormmh@gmail.com.|Department of Cardiology, Gentofte University Hospital, Copenhagen, Denmark. gormmh@gmail.com.
Gorm M
GM
Hansen
The Department of Forensic Medicine, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark. henrik.hegaard.sillesen@regionh.dk.
Henrik H
HH
Sillesen
The Department of Forensic Medicine, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark. Hans.Petter.Hougen@sund.ku.dk.
Hans P
HP
Hougen
Department of Cardiology, Gentofte University Hospital, Copenhagen, Denmark. prh@dadlnet.dk.
Peter R
PR
Hansen
Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore. YangLiang@ntu.edu.sg.
Liang
L
Yang
Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark. ttn@sund.ku.dk.
Tim
T
Tolker-Nielsen
Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore. SCSchuster@ntu.edu.sg.
Stephan C
SC
Schuster
Singapore Centre on Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University, Singapore, Singapore. mgivskov@sund.ku.dk.|Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark. mgivskov@sund.ku.dk.
Michael
M
Givskov
D050197:Atherosclerosis / Q000382:microbiology* / Q000473:pathology*; D044822:Biodiversity; D016000:Cluster Analysis; D058893:DNA Barcoding, Taxonomic; D005260:Female; D059014:High-Throughput Nucleotide Sequencing; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D054892:Metagenome; D064307:Microbiota; D058226:Plaque, Atherosclerotic / Q000382:microbiology*