Biology subjects

Pink, R.

Publications and source records attributed to Pink, R..

3 recordsLinked to original sources

bioRxiv2020

Early cardiac inflammation as a driver of murine model of Arrhythmogenic Cardiomyopathy

The study of a desmoglein 2 murine model of arrhythmogenic cardiomyopathy revealed cardiac inflammation as a key early event leading to fibrosis. Arrhythmogenic Cardiomyopathy (AC) is an inherited heart muscle disorder leading to ventricular arrhythmias and heart failure due to abnormalities in the cardiac desmosome. We examined how loss of desmoglein 2 (Dsg2) in the young murine heart leads to development of AC. Cardiomyocyte apoptosis was an early cellular phenotype and RNA-Seq analysis revealed early activation of inflammatory-associated pathways in Dsg2 null (Dsg2−/−) hearts at postnatal day 14 (Two weeks) that were absent in the fibrotic heart of adult mice (Ten weeks). This included upregulation of iRhom2/ADAM17 and its associated pro-inflammatory cytokines and receptors such as TNFα, IL6R and IL-6. Furthermore, genes linked to specific macrophage populations were upregulated. This suggests cardiomyocyte stress triggers an early immune response to clear apoptotic cells allowing tissue remodelling later on in the fibrotic heart. Our analysis at different disease stages implicate inflammation related to loss of desmoglein 2 as a major mechanism for disease progression.View Full Text

immunology↗

bioRxiv2019

An intergenic non-coding RNA promoter required for histone modifications in the human β-globin chromatin domain

Transcriptome analyses show a surprisingly large proportion of the mammalian genome is transcribed; much more than can be accounted for by genes and introns alone. Most of this transcription is non-coding in nature and arises from intergenic regions, often overlapping known protein-coding genes in sense or antisense orientation. The functional relevance of this widespread transcription is unknown. Here we characterize a promoter responsible for initiation of an intergenic transcript located approximately 3.3 kb and 10.7 kb upstream of the adult-specific human {beta}-globin genes. Mutational analyses in {beta}-YAC transgenic mice show that alteration of intergenic promoter activity results in ablation of H3K4 di- and tri-methylation and H3 hyperacetylation extending over a 30 kb region immediately downstream of the initiation site, containing the adult {delta}- and {beta}-globin genes. This results in dramatically decreased expression of the adult genes through position effect variegation in which the vast majority of definitive erythroid cells harbor inactive adult globin genes. In contrast, expression of the neighboring {varepsilon}- and {gamma}-globin genes is completely normal in embryonic erythroid cells, indicating a developmentally specific variegation of the adult domain. Our results demonstrate a role for intergenic non-coding RNA transcription in the propagation of histone modifications over chromatin domains and epigenetic control of {beta}-like globin gene transcription during development.

genetics↗

bioRxiv2019

Clinical long-read sequencing of the human mitochondrial genome for mitochondrial disease diagnostics

PurposeLong-read, third generation, sequencing technologies have the potential to improve current state of the art diagnostic strategies. In order to determine if long-read sequencing technologies are suitable for the diagnosis of mitochondrial disorders due to mitochondrial DNA (mtDNA) variants, particularly large deletions, we compared the performance of Oxford Nanopore Technologies (ONT) MinION to current diagnostic methods.\n\nMethodsWe sequenced mtDNA from nine patients with mtDNA deletion disorders and three normal controls with both ONT MinION and Illumina MiSeq. We applied a computational pipeline to estimate the positions of mtDNA deletions in patients, and subsequently validated the breakpoints using Sanger sequencing.\n\nResultsWe were able to detect mtDNA deletions with a MinION workflow, successfully calling the disease causing event in all cases. Sequencing coverage was in most cases significantly more (p=0.03, Wilcoxon test) uniform with MinION than with MiSeq and subsequent correction of MinION reads improved breakpoint accuracy and reduced false positives. Although heteroplasmic single nucleotide variants are detectable, the high number of false positives and false negatives precludes their use in diagnostics at this time.\n\nConclusionThe MinION is becoming an increasingly attractive diagnostic tool due to the reducing cost, increasing accuracy, and the speed at which data can be obtained.

genomics↗