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New roles for the major human 3'-5' exonuclease TREX1 in human disease.

ABSTRACT: Aicardi-Goutières syndrome (AGS), Systemic Lupus Erythematosus (SLE), Familial Chilblain Lupus (FCL) and Retinal Vasculopathy and Cerebral Leukodystrophy (RVCL) {a new term encompassing three independently described conditions with a common etiology--Cerebroretinal Vasculopathy (CRV), Hereditary Vascular Retinopathy (HVR) and Hereditary Endotheliopathy, Retinopathy and Nephropathy (HERNS)}--have previously been regarded as distinct entities. However, recent genetic analysis has demonstrated that each of these diseases maps to chromosome 3p21 and can be caused by mutations in TREX1, the major human 3'-5' exonuclease. In this review, we discuss the putative functions of TREX1 in relationship to the clinical, genetic and functional characteristics of each of these conditions.

SUBMITTER: Kavanagh D

PROVIDER: S-EPMC2825026 | biostudies-literature | 2008 Jun

REPOSITORIES: biostudies-literature

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New roles for the major human 3'-5' exonuclease TREX1 in human disease.

Kavanagh David D Spitzer Dirk D Kothari Parul H PH Shaikh Aisha A Liszewski M Kathryn MK Richards Anna A Atkinson John P JP

Cell cycle (Georgetown, Tex.) 20080616 12

Aicardi-Goutières syndrome (AGS), Systemic Lupus Erythematosus (SLE), Familial Chilblain Lupus (FCL) and Retinal Vasculopathy and Cerebral Leukodystrophy (RVCL) {a new term encompassing three independently described conditions with a common etiology--Cerebroretinal Vasculopathy (CRV), Hereditary Vascular Retinopathy (HVR) and Hereditary Endotheliopathy, Retinopathy and Nephropathy (HERNS)}--have previously been regarded as distinct entities. However, recent genetic analysis has demonstrated that ...[more]

PMID: 18583934

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Exonuclease TREX1 degrades double-stranded DNA to prevent spontaneous lupus-like inflammatory disease.

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Project description:Maintaining genome integrity is important for cells and damaged DNA triggers autoimmunity. Previous studies have reported that Three-prime repair exonuclease 1(TREX1), an endogenous DNA exonuclease, prevents immune activation by depleting damaged DNA, thus preventing the development of certain autoimmune diseases. Consistently, mutations in TREX1 are linked with autoimmune diseases such as systemic lupus erythematosus, Aicardi-Goutières syndrome (AGS) and familial chilblain lupus. However, TREX1 mutants competent for DNA exonuclease activity are also linked to AGS. Here, we report a nuclease-independent involvement of TREX1 in preventing the L1 retrotransposon-induced DNA damage response. TREX1 interacted with ORF1p and altered its intracellular localization. Furthermore, TREX1 triggered ORF1p depletion and reduced the L1-mediated nicking of genomic DNA. TREX1 mutants related to AGS were deficient in inducing ORF1p depletion and could not prevent L1-mediated DNA damage. Therefore, our findings not only reveal a new mechanism for TREX1-mediated L1 suppression and uncover a new function for TREX1 in protein destabilization, but they also suggest a novel mechanism for TREX1-mediated suppression of innate immune activation through maintaining genome integrity.

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Rare variants of the 3'-5' DNA exonuclease <i>TREX1</i> in early onset small vessel stroke.

Project description:Background: Monoallelic and biallelic mutations in the exonuclease TREX1 cause monogenic small vessel diseases (SVD). Given recent evidence for genetic and pathophysiological overlap between monogenic and polygenic forms of SVD, evaluation of TREX1 in small vessel stroke is warranted. Methods: We sequenced the TREX1 gene in an exploratory cohort of patients with lacunar stroke (Edinburgh Stroke Study, n=290 lacunar stroke cases). We subsequently performed a fully blinded case-control study of early onset MRI-confirmed small vessel stroke within the UK Young Lacunar Stroke Resource (990 cases, 939 controls). Results: No patients with canonical disease-causing mutations of TREX1 were identified in cases or controls. Analysis of an exploratory cohort identified a potential association between rare variants of TREX1 and patients with lacunar stroke. However, subsequent controlled and blinded evaluation of TREX1 in a larger and MRI-confirmed patient cohort, the UK Young Lacunar Stroke Resource, identified heterozygous rare variants in 2.1% of cases and 2.3% of controls. No association was observed with stroke risk (odds ratio = 0.90; 95% confidence interval, 0.49-1.65 p=0.74). Similarly no association was seen with rare TREX1 variants with predicted deleterious effects on enzyme function (odds ratio = 1.05; 95% confidence interval, 0.43-2.61 p=0.91). Conclusions: No patients with early-onset lacunar stroke had genetic evidence of a TREX1-associated monogenic microangiopathy. These results show no evidence of association between rare variants of TREX1 and early onset lacunar stroke. This includes rare variants that significantly affect protein and enzyme function. Routine sequencing of the TREX1 gene in patients with early onset lacunar stroke is therefore unlikely to be of diagnostic utility, in the absence of syndromic features or family history.

| S-EPMC5717473 | biostudies-literature

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