Risultati per: Fumo e malattia coronarica: responsabile un singolo gene

Senza DRG, i pazienti non hanno accesso a farmaci e monitoraggio

Senza DRG, i pazienti non hanno accesso a farmaci e monitoraggio

New England Journal of Medicine, Ahead of Print.

New England Journal of Medicine, Ahead of Print.

New England Journal of Medicine, Ahead of Print.

New England Journal of Medicine, Ahead of Print.

Neurologi: ‘si apre una nuova storia per i pazienti’

Circulation, Volume 150, Issue Suppl_1, Page A4142133-A4142133, November 12, 2024. The majority of variants identified by genome-wide association studies (GWAS) that influence coronary artery disease (CAD) risk reside in noncoding regions of the genome, making it challenging to link them with the genes they regulate. The 9p21.3 locus is the most impactful genetic risk locus for CAD. Due to the complexity of this locus, the causal genes and molecular mechanisms are poorly understood. Enhancers are cell type specific, and vascular smooth muscle cells (SMC) are known to have the highest heritable risk for CAD and play a major role in the atherosclerotic plaque formation. Here, we report efforts to systematically map SMC specific enhancers to neighboring genes within the 9p21.3 locus by implementing single cell CRISPRi enhancer screens and validating single causal variants in these enhancers. First, we intersected CAD GWAS loci with human coronary artery SMC (HCASMC) ATAC-seq and H3K27ac ChIP-seq datasets to focus on the disease relevant SNPs. This analysis identified 27 SNPs in 11 enhancers, that we targeted with CRISPRi machinery and analyzed at 5- and 10-days post transduction. As target genes in the locus are lowly expressed, we employed the targeted Perturb-seq (TAP-seq) approach for library generation and sequencing. We identified several enhancer-gene -pairs, including a strong enhancer-gene connection to bothCDKN2AandCDKN2B. Additionally, we identified multiple enhancer regions that controlMTAPexpression, with smaller but significant effects. We followed up with individual validation of enhancer-gene pairs through qPCR. Furthermore, these results are consistent with chromosomal interaction data obtained from our previous HiChIP. Notably, enhancers 5 and 6 were strong regulators of CDNK2B and CDKN2A expression, so we investigated how variants in these enhancers might directly disrupt transcription factor (TF) binding. By using luciferase enhancer assays, CHIPseq and phenotypic in vitro assays we linked this variation with TFs that drive vascular calcification in SMCs. Our results identify new variant to gene links and suggest how the genetic risk in 9p21 is mediated in the vascular wall, providing mechanistic understanding of vascular calcification and genetic risk of CAD and suggesting a novel mechanism of how 9p21.3 mediates disease risk.

Circulation, Volume 150, Issue Suppl_1, Page A4145948-A4145948, November 12, 2024. Background:Mutations in desmoplakin gene (DSP) are associated with arrhythmogenic cardiomyopathy (ARVC). Myosin-binding protein C gene (MYBPC3) is a sarcomere gene and is associated with hypertrophic cardiomyopathy (HCM). The expression of both of these genes has only been reported twice in the literature. It remains unclear whether the expression of both mutation carries a more severe phenotype than carrying on of the mutations only.Case Description:A 21-year-old female with history of sustained ventricular fibrillation (VT) at age 18, VT arrest at age 20,dilated cardiomyopathy with LVEF 30-35% and subcutaneous ICD, who was admitted after multiple ICD defibrillations. Device interrogation demonstrated 23 monomorphic VT episodes treated with 44 shocks by the ICD. Coronary angiogram demonstrated non-obstructive coronary arteries. Patient underwent VT ablation, complicated by incessant VT from LV summit which was eliminated during procedure. Cardiac MRI demonstrated RVEF 33%, regional dyskinesis in the sub-tricuspid area and RV outflow tract. cMRI also demonstrated subepicardial late gadolinium enhancement at the level of the mid antero/infero lateral walls with extension into the apicolateral wall and mid inferoseptal territory. These findings heightened suspicion for left ventricle fatty infiltration. However, endomyocardial biopsy negative for inflammation or granuloma, no fibrosis, negative iron and amyloid staining. Left-dominant arrhythmogenic cardiomyopathy was diagnosed based on cMRI findings, LV systolic dysfunction, and arrhythmia of LV origin. Subcutaneous ICD was explanted and replaced with a dual chamber ICD. Patient was discharged on Mexiletine and GDMT for HFrEF. Genetics testing later revealed rare co-occurance of two genetic mutations including MYBPC3 and DSP.Discussion:The presentation of both DSP and MYBPC3 mutations in patients diagnosed with ARVC has only been reported twice in the literature and a is an extremely rare phenomenon. There is currently no sufficient understanding of the genotype-phenotype correlation of DSP and MYBPC3 mutations in the clinical expression of their associated inherited cardiac diseases. Therefore, more research need to investigate this phenomena and to study whether the co-presence of both of these two mutations is associated with a more severe phenotypic expression of HCM and ARVC.

Circulation, Volume 150, Issue Suppl_1, Page A4147026-A4147026, November 12, 2024. Introduction:Lipoprotein a (Lp(a)) levels are an often unmeasured predictor of future risk of cardiovascular disease. Unlike LDL, HDL, and triglycerides, Lp(a) levels are believed to be genetically determined; they are not altered by lipid-lowering medications or dietary changes, and are consistent over a lifetime, making them a potential early-life predictor of adult morbidity. However, genetic predictors of Lp(a) are challenging to design. Repeats of the kringle IV subtype 2 domain (KIV-2) contribute significantly but are extremely challenging to quantify via next-generation sequencing; this variability is particularly impactful in non-European ancestries.Methods:We analyzed ~110K individuals with paired clinical and exome sequencing data from six medical centers. We developed a coverage-based method to determine KIV-2 repeat counts. We validated that these counts associated with clinical Lp(a) measurements derived from the course of care (n = 2039 individuals). We calculated an expected Lp(a) in units of nmol/L using a genetic risk score (GRS) based on 43 variants in the Lp(a) gene. We identified instances of CAD via ICD9CM, ICD10CM and SNOMED terms present in the medical record.Results:Adding the number of KIV-2 repeats to the GRS substantially improved prediction of clinical Lp(a) measurements, for example improving the r-squared for non-Europeans five-fold (from 0.05 to 0.22). Individuals with fewer than 15 estimated KIV-2 repeats and a high GRS-predicted Lp(a) (high risk group) have a mean measured Lp(a) of that is 10-fold that of those in the lowest category of GRS-predicted Lp(a) (low risk group). In the full cohort, most of whom had not been measured for Lp(a), we find that relative to the low risk group, the high risk individuals are 1.6x more likely to have CAD.Conclusion:Lp(a) is a potentially useful biomarker with consistency over a lifetime and implications for future cardiovascular morbidity. We developed a method for estimating the number of KIV-2 repeats, a challenging component of genetic prediction of Lp(a). This estimate can be used in combination with a GRS to predict Lp(a), especially in individuals with non-European ancestry where GRS-based estimates fall short. The final prediction is associated with increased risk of CAD.

Circulation, Volume 150, Issue Suppl_1, Page A4133040-A4133040, November 12, 2024. Introduction:Heart failure (HF) is associated with high mortality and morbidity, and there are limited therapeutic options available to improve cardiac muscle function. Recent studies suggest that the impairment of cardiomyocyte T-tubule microdomains is a key factor in HF pathophysiology. AAV9-cBIN1 gene therapy effectively addresses this impairment. However, the kinetics and biodistribution of AAV9-cBIN1 have not been explored, limiting the knowledge of the transcription efficiency and organ specificity of cBIN1 gene therapy when delivered systemically.Aim:This study aims to elucidate the kinetics and biodistribution of AAV9-cBIN1 in a murine model.Method:Adult male C57BL/6J mice (n=20) were administered a single retro-orbital injection of AAV9-CMV-cBIN1-V5 at a dose (2×10^12 vg/kg) known to effectively transduce the majority of cardiomyocytes. Mice were sacrificed at pre-determined time points: prior to injection (Day 0, n=2) and post-injection at Days 3, 7, 14, 28, 56, and 84 (n=3/group). Tissues were harvested from the heart, lung, liver, kidney, skeletal muscle, and spleen. Genomic DNA was extracted and analyzed using qPCR to determine vector genome (vg) copies. For transcriptional analysis of the AAV9-transduced exogenous gene, mRNA was extracted and converted to cDNA for qRT-PCR quantification ofcBin1-V5, normalized to the housekeeping geneHprt1.Results:All mice survived to their designated sacrifice times. Kinetic analysis demonstrated a time-dependent expression of the exogenouscBin1-V5gene, with peak expression observed at 4 weeks in both the heart and liver, with expression declining in the liver after this peak (Figure 1A). Genomic DNA analysis showed a gradual increase and plateau of viral genome distribution in the heart between 2-4 weeks, while in the liver, distribution peaked sharply between Days 3-7 and then decreased. When correcting the gene transcription ofcBin1-V5(ΔCq ofV5/Hprt1) for vector DNA vg copies in the tissue, the transcription efficiency in the heart was higher than in the liver (Figure 1B). Outside of the liver and heart,cBin1-V5mRNA expression was undetectable in all other tissues by Day 56.Conclusion:In adult male mice, a single systemic administration of AAV9-cBIN1 results in robust transduction and higher transcription efficiency in the heart compared to the liver. AAV9-cBIN1 holds promise for targeted gene therapy in cardiac tissues, with minimal off-target expression in other organs.

Circulation, Volume 150, Issue Suppl_1, Page A4145103-A4145103, November 12, 2024. Dilated cardiomyopathy (DCM) is a clinical condition with tremendous diversity of etiology. In familial forms of DCM, there has been a compelling evidence of immense genetic heterogeneity that implicate various mechanisms. Recently, biallelic loss-of-function (LOF) variants in the nebulin-related-anchoring protein (NRAP) gene have been reported in an ultra-rare form of DCM inherited recessively.In this study, we sought to describe the clinical and genetic spectrum associated withNRAPvariants in our highly consanguineous population. Genetic analysis with whole exome sequencing, conducted on consecutively recruited cases of DCM, identified 13 consanguineous families with 6 different LOF variants inNRAP. Segregation analysis detected 25 homozygous and 25 heterozygous individuals. Interestingly, only 18 of the 25 homozygous cases were symptomatic with a remarkable variability of age of onset (9 months to 47 years, median 5 years), of whom 9 cases died with a median age of death of 3 years (range: 9 months to 13 years). None of the heterozygous individuals was clinically symptomatic. Of note, 3 homozygous cases underwent heart transplantation at the ages of 8, 11, and 14 years who are alive with a follow up of 6 years, 3 years, and 3 months respectively.Our work illustrates a notable clinical variability of DCM associated withNRAPLOF variants. This observation suggests an underling complex mechanism ofNRAP-related DCM that deviates from simple mendelian inheritance and plausibly implicates modifiers. The reduced penetrance and variable expression underscore the need of exercising precaution when counseling individuals and families found to haveNRAPvariants.

Circulation, Volume 150, Issue Suppl_1, Page A4132120-A4132120, November 12, 2024. Epidemiological studies indicate that individuals with Down syndrome (DS) have an increased risk of leukemia and neuronal diseases but a significantly reduced incidence of most solid tumors and advanced vascular dysfunction. This suggests that one or a combination of trisomy genes on human chromosome 21 (HSA21) or murine chromosome 16 (Mmu16) may be responsible for protecting against vasculopathy. Our previous research has shown that theDown syndrome critical region (Dscr)-1gene, located on HSA21 orMmu16, encodes a feedback modulator of calcineurin-NFAT signaling in endothelial cells (ECs). Null mutation or overexpression of Dscr-1 has been found to increase or prevent septic mortality, angiogenesis, liver steatosis, and susceptibility of tumor metastasizing to the lung, respectively, demonstrating its significant role in these processes.In a unique approach, we crossed DS model mice withApoE-null mice and fed them a high-fat diet (HFD) for 12 weeks to survey the effects of DS-related genes on atherosclerosis. The results were striking, with HFD-mediated increased LDL and triglyceride levels inApoE-null mice significantly reduced in the combined DS plusApoE-null mice. This innovative method allowed us to observe a remarkable (~35%) reduction in ApoE-null mediated atheroma formation in the DS model. This finding was also replicated in EC-specific DSCR-1 transgenic (DSCR-1ECTg) mice.Furthermore, to test the effect of HSA21, we have collected DS patient-derived trisomy and disomy iPS cells and executed them for the chromatin conformation capture analysis and thein vitroECs differentiation experiments. DS-derived trisomy iPS cells already changed the whole chromatin structure, typically within the X chromosome. Moreover, the trisomy iPS-derived ECs revealed less proliferation compared to the disomy. RNA-seqs indicated trisomy iPS derived ECs dramatically (21-fold) increasedDSCR-1, but some HSA21 genes, Alzheimer’s relatedAppandBace2, e.g., were inversely reduced the expression.Our comprehensive studies not only shed new light on the mechanisms of atherosclerosis in vascular pathology but also offer potential therapeutic strategies. The discovery of theDscr-1gene on the DS chromosome, which could be a powerful tool in combating lifestyle-related vascular diseases, underscores the significance of our research.