Dataset Information

Single AAV-mediated CRISPR-Nme2Cas9 efficiently reduces mutant hTTR expression in a transgenic mouse model of transthyretin amyloidosis.

ABSTRACT: Transthyretin (TTR) amyloidosis is a hereditary life-threatening disease characterized by deposition of amyloid fibrils. The main causes of TTR amyloidosis are mutations in the TTR gene that lead to the production of misfolded TTR protein. Reducing the production of toxic protein in the liver is a validated strategy to treat TTR amyloidosis. In this study, we established a humanized mouse model that expresses mutant human TTR (hTTR; V30M) protein in the liver to model TTR amyloidosis. Then, we compared the efficiency of reducing the expression of mutant hTTR by dual adeno-associated virus 8 (AAV8)-mediated split SpCas9 with that by single AAV8-mediated Nme2Cas9 in this model. With two gRNAs targeting different exons, dual AAV-mediated split SpCas9 system achieved efficiencies of 37% and 34% reduction of hTTR mRNA and reporter GFP expression, respectively, in the liver. Surprisingly, single AAV-mediated Nme2Cas9 treatment resulted in 65% and 71% reduction of hTTR mRNA and reporter GFP, respectively. No significant editing was identified in predicted off-target sites in the mouse and human genomes after Nme2Cas9 targeting. Thus, we provide proof of principle for using single AAV-mediated CRISPR-Nme2Cas9 to effectively reduce mutant hTTR expression in vivo, which may translate into gene therapy for TTR amyloidosis.

SUBMITTER: Wen J

PROVIDER: S-EPMC8753293 | biostudies-literature | 2022 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Single AAV-mediated CRISPR-Nme2Cas9 efficiently reduces mutant hTTR expression in a transgenic mouse model of transthyretin amyloidosis.

Wen Jinkun J Cao Tianqi T Wu Jinni J Chen Yuxi Y Zhi Shengyao S Huang Yanming Y Zhen Peilin P Wu Guanglan G Aagaard Lars L Zhong Jianxin J Liang Puping P Huang Junjiu J

Molecular therapy : the journal of the American Society of Gene Therapy 20210514 1

Transthyretin (TTR) amyloidosis is a hereditary life-threatening disease characterized by deposition of amyloid fibrils. The main causes of TTR amyloidosis are mutations in the TTR gene that lead to the production of misfolded TTR protein. Reducing the production of toxic protein in the liver is a validated strategy to treat TTR amyloidosis. In this study, we established a humanized mouse model that expresses mutant human TTR (hTTR; V30M) protein in the liver to model TTR amyloidosis. Then, we c ...[more]

PMID: 33992807

Similar Datasets

Project description:AimsCardiac transthyretin amyloidosis (ATTR-CM) is a progressive and fatal condition. Prognosis can be determined at diagnosis according to the National Amyloidosis Centre (NAC) transthyretin amyloidosis (ATTR) stage. We sought to examine how NAC ATTR stage changes during follow-up and whether it maintains its prognostic value throughout the disease course.Methods and resultsWe performed a retrospective study of 945 patients with wild-type ATTR-CM (wtATTR-CM) or hereditary ATTR-CM associated with the V122I variant (V122I-hATTR-CM) who were diagnosed and serially evaluated at the UK NAC. Patients who commenced any disease-modifying therapy for amyloidosis were censored at the time of doing so. Landmark Kaplan-Meier survival analyses were performed at diagnosis (n = 945) and at 6 ± 1 (n = 432), 12 ± 3 (n = 562), and 24 ± 3 (n = 316) months and stratified by recalculated NAC ATTR stage at the relevant time point. Cox regression analyses were performed to assess the prognostic significance during follow-up of an increase in NAC ATTR stage from Stage I at diagnosis. Mortality in ATTR-CM was predicted by NAC ATTR stage at each time point [Stage II vs. I, hazard ratios (HRs) 1.95-2.67; P < 0.001; Stage III vs. II, HRs 1.64-2.25; P < 0.001-0.013]. An increase from NAC ATTR Stage I, which occurred in 21%, 32%, and 44% of evaluable patients at 6, 12, and 24 months of follow-up respectively, was highly predictive of ongoing mortality at each time point (HRs 2.58-3.22; P < 0.001) and in each genotypic subgroup (HRs 1.86-4.38; P < 0.05). Increase in NAC ATTR stage occurred earlier in V122I-hATTR-CM than in wtATTR-CM (43% vs. 27% at 12 months of follow-up; P = 0.003).ConclusionsNational Amyloidosis Centre ATTR stage predicts ongoing survival throughout the disease natural history in ATTR-CM, and an increase from NAC ATTR Stage I at diagnosis to a higher NAC ATTR stage predicts mortality throughout follow-up. Serial calculation of NAC ATTR stage suggests a more aggressive phenotype in V122I-hATTR-CM than in wtATTR-CM.

Project description:AimsMutant transthyretin (ATTRm) amyloidosis is a systemic disease caused by the deposition of amyloid fibrils derived from mutated transthyretin. Although cardiac involvement impacts the prognosis of patients with ATTRm amyloidosis, the incidence of cardiac events, such as bradyarrhythmia, ventricular tachycardia, and heart failure, has not been fully elucidated. The aim of this study was to evaluate the prognosis and predictors of clinical outcomes, including cardiac events, in patients with ATTRm amyloidosis in Japan.Methods and resultsWe evaluated 90 consecutive patients with ATTRm amyloidosis at Kumamoto University. ATTRm amyloidosis was diagnosed by the observation of both amyloid fibril deposition on tissue biopsy and a transthyretin mutation on sequential analysis. Sympathetic nerve activity was evaluated in 59 patients using 123-iodine metaiodobenzylguanidine (123 I-MIBG) imaging. The endpoint was a composite of all-cause death, hospitalization for heart failure, and implantation of a pacemaker, implantable cardioverter defibrillator, or cardiac resynchronization therapy defibrillator. Sixty-seven patients had the Val30Met mutation (74%). The composite endpoint occurred in 23 patients (26%): all-cause death (n = 6), hospitalization for worsening heart failure (n = 1), and implantation of an implantable cardioverter defibrillator (n = 6), cardiac resynchronization therapy defibrillator (n = 3), or pacemaker (n = 7). The 5-year incident rate for clinical outcomes was 19%. In a multivariate Cox hazard analysis, age [hazard ratio (HR): 1.07, 95% confidence interval (95% CI): 1.01-1.12, P = 0.015], PQ interval (HR: 1.01, 95% CI: 1.00-1.02, P = 0.042), interventricular septum thickness in diastole (HR: 1.25, 95% CI: 1.09-1.42, P = 0.001), and non-Val30Met mutation (HR: 4.31, 95% CI: 1.53-12.16, P = 0.006) were independent predictive factors of clinical outcomes. Kaplan-Meier analysis demonstrated a significantly higher probability of the composite endpoint in the non-Val30Met group than in the Val30Met group (log-rank test: P = 0.002) and in patients with left ventricular hypertrophy than in patients without left ventricular hypertrophy (log-rank test: P < 0.001). In patients who underwent 123 I-MIBG imaging, a delayed heart-to-mediastinum (HM) ratio <1.6 was a significant predictive factor of the composite endpoint (HR: 4.98, 95% CI: 1.73-14.37, P = 0.003) in the univariate Cox hazard analyses. Kaplan-Meier curve analysis showed that a delayed HM ratio <1.6 was associated with a poor prognosis (log-rank test: P = 0.001).ConclusionsNon-Val30Met mutation, septal hypertrophy, and a delayed HM ratio are useful predictors of clinical outcomes in patients with ATTRm amyloidosis in Japan. These results suggest that it is important to evaluate cardiac involvement in terms of morphological (left ventricular hypertrophy) and functional (cardiac denervation) perspectives using echocardiography and 123 I-MIBG imaging, respectively.

Dataset Information

Single AAV-mediated CRISPR-Nme2Cas9 efficiently reduces mutant hTTR expression in a transgenic mouse model of transthyretin amyloidosis.

Publications

Single AAV-mediated CRISPR-Nme2Cas9 efficiently reduces mutant hTTR expression in a transgenic mouse model of transthyretin amyloidosis.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets