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Biology subjects

Wilson, C. L.

Publications and source records attributed to Wilson, C. L..

3 recordsLinked to original sources

UCHL1-dependent control of Hypoxia-Inducible Factor Transcriptional Activity in Liver Disease.

Liver fibrosis is the excessive accumulation of extracellular matrix proteins that occurs in most types of chronic liver diseases. Fibrosis is associated with the activation of hepatic stellate cells (HSCs) which transdifferentiate into a myofibroblast like phenotype that is contractile, proliferative and profibrogenic. Hypoxia-inducible factor 1 (HIF1), an oxygen-sensitive transcription factor, is elevated during HSC activation and promotes the expression of profibrotic mediator HIF target genes. HIF activation during HSC activation can by either due to localised decreases in oxygen levels, or through oxygen-independent mechanisms that are not completely understood. Here we describe a role for the deubiquitinase UCHL1 in regulating HIF levels and activity during HSC activation and liver fibrosis. Increased HIF1 expression correlated with induction of UCHL1 mRNA and protein with HSC activation. Genetic deletion or chemical inhibition of UCHL1 impaired HIF activity through reduction of HIF1 levels. UCHL1 specifically cleaves the degradative ubiquitin chains from HIF1 leading to increased HIF1 levels, even in sufficiently oxygenated cells. Furthermore, our mechanistic studies have shown that UCHL1 elevates HIF activity through specific cleavage of degradative ubiquitin chains, elevates levels of pro-fibrotic gene expression and increases proliferation rates. These results demonstrate how small molecule inhibitors of DUBs can modulate the activity of HIF transcription factors in liver disease. Furthermore, inhibition of HIF activity via modulation of the ubiquitin-proteasomal degradation pathway may represent a therapeutic opportunity with other HIF-related pathologies. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=110 SRC="FIGDIR/small/523142v1_ufig1.gif" ALT="Figure 1"> View larger version (25K): org.highwire.dtl.DTLVardef@1d82ee9org.highwire.dtl.DTLVardef@1eff21aorg.highwire.dtl.DTLVardef@1ffb0eforg.highwire.dtl.DTLVardef@1b93dc9_HPS_FORMAT_FIGEXP M_FIG C_FIG

cell biology↗

Generalizability of "GWAS hits" in clinical populations: Lessons from childhood cancer survivors

With mounting interest in translating GWAS hits from large meta-analyses (meta-GWAS) in diverse clinical settings, evaluating their generalizability in target populations is crucial. Here we consider long-term survivors of childhood cancers from the St. Jude Lifetime Cohort Study and show the limited generalizability of 1,376 robust SNP associations reported in the general population across 12 complex anthropometric and cardiometabolic phenotypes (N=2,231; observed-to-expected replication ratio=0.68, P=2.4x10-9). An examination of five comparable phenotypes in a second independent cohort of survivors from the Childhood Cancer Survivor Study corroborated the overall limited generalizability of meta-GWAS hits to survivors (N=4,212, observed-to-expected replication ratio=0.53, P=1.1x10-16). Meta-GWAS hits were less likely to be replicated in survivors exposed to cancer therapies associated with phenotype risk. Examination of complementary DNA methylation data in a subset of survivors revealed that treatment-related methylation patterns at genomic sites linked to meta-GWAS hits may disrupt established genetic signals in survivors.

genetics↗

A pseudo-meiotic centrosomal function of TEX12 in cancer

Cell division by meiosis involves an extraordinary chromosome choreography including pairing, synapsis and crossing over between homologous chromosomes1, 2. The many meiosis-specific genes involved in these processes also constitute a latent toolbox of chromosome remodelling and recombination factors that may be exploited through aberrant expression in cancer3, 4. Here, we report that TEX12, a structural protein involved in meiotic chromosome synapsis5-7, is aberrantly expressed in human cancers, with high TEX12 levels correlating with poor prognosis. We find that TEX12 knock-down causes proliferative failure in multiple cancer cell lines, and confirm its role in the early stages of oncogenesis through murine cancer models. Remarkably, somatically expressed TEX12 localises to centrosomes, leading to altered centrosome number and structure, features associated with cancer development. Further, we identify TEX12 in meiotic centrin-rich bodies, likely precursors of the mitotic centrosome, suggesting that this may represent an additional cellular function of TEX12 in meiosis that has been previously overlooked. Thus, we propose that an otherwise meiotic function of TEX12 in centrosome duplication is responsible for promoting oncogenesis and cellular proliferation in cancer, which may be targeted for novel cancer therapeutics and diagnostics.

cell biology↗