Next generation sequencing and RNA-seq characterization of adipose tissue in the Nile crocodile (Crocodylus niloticus) in South Africa: Possible mechanism(s) of pathogenesis and pathophysiology of pansteatitis

Autor: Joseph P Chamunorwa, Ana-Mari Bosman, Kgomotso P. Sibeko-Matjilla, Jonathan Featherston, Marinda C. Oosthuizen, Jan G. Myburgh, O. I. Azeez
Rok vydání: 2019
Předmět:
0301 basic medicine
Physiology
Gene Expression
Adipose tissue
Apoptosis
Pathology and Laboratory Medicine
Transcriptome
South Africa
0302 clinical medicine
Cell Signaling
Immune Physiology
Gene expression
Medicine and Health Sciences
Immune Response
Alligators and Crocodiles
Base Composition
Innate Immune System
Multidisciplinary
Cell Death
Protein Kinase Signaling Cascade
biology
High-Throughput Nucleotide Sequencing
Eukaryota
Genomics
Signaling Cascades
Up-Regulation
Fatty acid synthase
Adipose Tissue
Cell Processes
030220 oncology & carcinogenesis
Vertebrates
Medicine
Cytokines
Anatomy
medicine.symptom
Transcriptome Analysis
Research Article
Signal Transduction
Science
Immunology
Down-Regulation
Proinflammatory cytokine
03 medical and health sciences
Signs and Symptoms
Diagnostic Medicine
Genetics
Pansteatitis
medicine
Animals
RNA
Messenger
Transcription factor
Gene
Inflammation
Sequence Analysis
RNA
Organisms
Crocodiles
Biology and Life Sciences
Computational Biology
Reptiles
Cell Biology
Molecular Development
Genome Analysis
Molecular biology
Gene Ontology
Biological Tissue
030104 developmental biology
Immune System
Amniotes
biology.protein
Steatitis
Developmental Biology
Zdroj: PLoS ONE
PLoS ONE, Vol 14, Iss 11, p e0225073 (2019)
ISSN: 1932-6203
DOI: 10.1371/journal.pone.0225073
Popis: BackgroundConcerted efforts to identify the pathogenesis and mechanism(s) involved in pansteatitis, (a generalized inflammation of the adipose tissue), that was attributed to the recent crocodile die off in the Olifants River and Loskop Dam in Kruger National Park, Mpumalanga, South Africa have been in the forefront of research in recent time. As part of the efforts, molecular characterization of healthy and pansteatitis adipose tissue was carried out by RNA sequencing (RNA-Seq) using Next Generation Sequencing (NGS) and de novo assembly of the adipose transcriptome, followed by differential gene expression analysis.MethodologyHealthy adipose tissue consisting of fifty samples was collected from the subcutaneous, visceral, intermuscular adipose tissues and the abdominal fat body of ten 4 years old juvenile crocodiles from a local crocodile farm in Pretoria, South Africa. Ten pansteatitis samples were collected from visceral and intermuscular adipose tissues of five crocodiles that were dying of pansteatitis.ResultsForty-two thousand, two hundred and one (42,201) transcripts were assembled, out of which 37, 835 had previously been characterized. The de novo assembled transcriptome had an N50 (average sequence) of 436 bp, percentage GC content of 43.92, which compared well with previously assembled transcripts in the saltwater crocodile. Seventy genes were differentially expressed and upregulated in pansteatitis. These included genes coding for extracellular matrix (ECM) signaling ligands, inflammatory cytokines and tumour necrosis factor alpha (TNFα) receptors, fatty acid synthase and fatty acid binding proteins, peroxisome proliferator-activated receptor gamma (PPARγ), nuclear factor and apoptosis signaling ligands, and mitogen activated protein kinase enzymes among others. Majority (88.6%) of the upregulated genes were found to be involved in hypoxia inducible pathways for activation of NFkβ and inflammation, apoptosis, Toll-like receptor pathway and PPARγ. Bicaudal homologous 2 Drosophila gene (BICD2) associated with spinal and lower extremity muscle atrophy was also upregulated in pansteatitis while Sphingosine -1-phosphate phosphatase 2 (SGPP2) involved in Sphingosine -1- phosphate metabolism was downregulated. Futhermore, Doublesex-mab-related transcription factor 1 (DMRT1) responsible for sex gonad development and germ cell differentiation was also downregulated.ConclusionThus, from the present study, based on differentially expressed genes in pansteatitis, affected Nile crocodiles might have died partly due to their inability to utilize stored triglycerides as a result of inflammation induced insulin resistance, leading to starvation in the midst of plenty. Affected animals may have also suffered muscular atrophy of the lower extremities and poor fertility.
Databáze: OpenAIRE
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