The Diagnostic Value of the 12-Lead ECG in Arrhythmogenic Left Ventricular Cardiomyopathy: Novel ECG Signs.

BACKGROUND: Electrocardiographic (ECG) findings in arrhythmogenic left ventricular cardiomyopathy (ALVC) are limited to small case series. OBJECTIVES: This study aimed to analyze the ECG characteristics of ALVC patients and to correlate ECG with cardiac magnetic resonance and genotype data. METHODS: We reviewed data of 54 consecutive ALVC patients (32 men, age 39 ± 15 years) and compared them with 84 healthy controls with normal cardiac magnetic resonance. RESULTS: T-wave inversion was often noted (57.4%), particularly in the inferior and lateral leads. Low QRS voltages in limb leads were observed in 22.2% of patients. The following novel ECG findings were identified: left posterior fascicular block (LPFB) (20.4%), pathological Q waves (33.3%), and a prominent R-wave in V1 with a R/S ratio ≥0.5 (24.1%). The QRS voltages were lower in ALVC compared with controls, particularly in lead I and II. At receiver-operating characteristic analysis, the sum of the R-wave in I to II ≤8 mm (AUC: 0.909; P < 0.0001) and S-wave in V1 plus R-wave in V6 ≤12 mm (AUC: 0.784; P < 0.0001) effectively discriminated ALVC patients from controls. It is noteworthy that 4 of the 8 patients with an apparently normal ECG were recognized by these new signs. Transmural late gadolinium enhancement was associated to LPFB, a R/S ratio ≥0.5 in V1, and inferolateral T-wave inversion, and a ringlike pattern correlated to fragmented QRS, SV1+RV6 ≤12 mm, low QRS voltage, and desmoplakin alterations. CONCLUSIONS: Pathological Q waves, LPFB, and a prominent R-wave in V1 were common ECG signs in ALVC. An R-wave sum in I to II ≤8 mm and SV1+RV6 ≤12 mm were specific findings for ALVC phenotypes compared with controls.

Variants in MHY7 Gene Cause Arrhythmogenic Cardiomyopathy.

BACKGROUND: Arrhythmogenic Cardiomyopathy (ACM) is a disease of the cardiac muscle, characterized by frequent ventricular arrhythmias and functional/ structural abnormalities, mainly of the right ventricle. To date, 20 different genes have been associated with ACM and the majority of them encode for desmosomal proteins. In this study, we describe the characterization of two novel variants in MHY7 gene, segregating in two ACM families. MYH7 encodes for myosin heavy chain ß (MHC-ß) isoform, involved in cardiac muscle contractility. METHOD AND RESULTS: In family A, the autopsy revealed ACM with biventricular involvement in both the proband and his father. In family B, the proband had been diagnosed as affected by ACM and implanted with implantable cardioverter defibrillator (ICD), due to ECG evidence of monomorphic ventricular tachycardia after syncope. After clinical evaluation, a molecular diagnosis was performed using a NGS custom panel. The two novel variants identified predicted damaging, located in a highly conserved domain: c. 2630T>C is not described while c.2609G>A has a frequency of 0.00000398. In silico analyses evaluated the docking characteristics between proteins using the Haddock2.2 webserver. CONCLUSIONS: Our results reveal two variants in sarcomeric genes to be the molecular cause of ACM, further increasing the genetic heterogeneity of the disease; in fact, sarcomeric variants are usually associated with HCM phenotype. Studies on the role of sarcomere genes in the pathogenesis of ACM are surely recommended in those ACM patients negative for desmosomal mutation screening.

Peptide Platform as a Powerful Tool in the Fight against COVID-19.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in a global pandemic causing over 195 million infections and more than 4 million fatalities as of July 2021.To date, it has been demonstrated that a number of mutations in the spike glycoprotein (S protein) of SARS-CoV-2 variants of concern abrogate or reduce the neutralization potency of several therapeutic antibodies and vaccine-elicited antibodies. Therefore, the development of additional vaccine platforms with improved supply and logistic profile remains a pressing need. In this work, we have validated the applicability of a peptide-based strategy focused on a preventive as well as a therapeutic purpose. On the basis of the involvement of the dipeptidyl peptidase 4 (DPP4), in addition to the angiotensin converting enzyme 2 (ACE2) receptor in the mechanism of virus entry, we analyzed peptides bearing DPP4 sequences by protein-protein docking and assessed their ability to block pseudovirus infection in vitro. In parallel, we have selected and synthetized peptide sequences located within the highly conserved receptor-binding domain (RBD) of the S protein, and we found that RBD-based vaccines could better promote elicitation of high titers of neutralizing antibodies specific against the regions of interest, as confirmed by immunoinformatic methodologies and in vivo studies. These findings unveil a key antigenic site targeted by broadly neutralizing antibodies and pave the way to the design of pan-coronavirus vaccines.

Urine LOX-1 and Volatilome as Promising Tools towards the Early Detection of Renal Cancer.

Renal cell carcinoma (RCC) represents around 3% of all cancers, within which clear cell RCC (ccRCC) are the most common type (70-75%). The RCC disease regularly progresses asymptomatically and upon presentation is recurrently metastatic, therefore, an early method of detection is necessary. The identification of one or more specific biomarkers measurable in biofluids (i.e., urine) by combined approaches could surely be appropriate for this kind of cancer, especially due to easy obtainability by noninvasive method. OLR1 is a metabolic gene that encodes for the Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), implicated in inflammation, atherosclerosis, ROS, and metabolic disorder-associated carcinogenesis. Specifically, LOX-1 is clearly involved in tumor insurgence and progression of different human cancers. This work reports for the first time the presence of LOX-1 protein in ccRCC urine and its peculiar distribution in tumoral tissues. The urine samples headspace has also been analyzed for the presence of the volatile compounds (VOCs) by SPME-GC/MS and gas sensor array. In particular, it was found by GC/MS analysis that 2-Cyclohexen-1-one,3-methyl-6-(1-methylethyl)- correlates with LOX-1 concentration in urine. The combined approach of VOCs analysis and protein quantification could lead to promising results in terms of diagnostic and prognostic potential for ccRCC tumors.

Genotypic Categorization of Loeys-Dietz Syndrome Based on 24 Novel Families and Literature Data.

Loeys-Dietz syndrome (LDS) is a connective tissue disorder first described in 2005 featuring aortic/arterial aneurysms, dissections, and tortuosity associated with craniofacial, osteoarticular, musculoskeletal, and cutaneous manifestations. Heterozygous mutations in 6 genes (TGFBR1/2, TGFB2/3, SMAD2/3), encoding components of the TGF-ß pathway, cause LDS. Such genetic heterogeneity mirrors broad phenotypic variability with significant differences, especially in terms of the age of onset, penetrance, and severity of life-threatening vascular manifestations and multiorgan involvement, indicating the need to obtain genotype-to-phenotype correlations for personalized management and counseling. Herein, we report on a cohort of 34 LDS patients from 24 families all receiving a molecular diagnosis. Fifteen variants were novel, affecting the TGFBR1 (6), TGFBR2 (6), SMAD3 (2), and TGFB2 (1) genes. Clinical features were scored for each distinct gene and matched with literature data to strengthen genotype-phenotype correlations such as more severe vascular manifestations in TGFBR1/2-related LDS. Additional features included spontaneous pneumothorax in SMAD3-related LDS and cervical spine instability in TGFB2-related LDS. Our study broadens the clinical and molecular spectrum of LDS and indicates that a phenotypic continuum emerges as more patients are described, although genotype-phenotype correlations may still contribute to clinical management.

Rhabdoid tumor predisposition syndrome caused by SMARCB1 constitutional deletion: prenatal detection of new case of recurrence in siblings due to gonadal mosaicism.

Rhabdoid tumors are aggressive malignancies that show loss-of-function mutations of SMARCB1 gene, a member of the SWI/SNF chromatin-remodeling complex controlling gene transcription. One-third of patients affected by rhabdoid tumor harbor a germ-line mutation of SMARCB1 defining a rhabdoid tumor predisposition syndrome. The occurrence of a second somatic mutation determines the development of neoplasia in a two-hit model. Most germ-line mutations occur de novo, and few cases of recurrence in a sibship have been described. Here we report on a new Italian family with recurrence of SMARCB1 germ-line deletion in two siblings due to gonadal mosaicism. The deletion was identified in the 9-month-old proband with malignant rhabdoid tumor of the right kidney and disseminated metastases. Testing of both parents confirmed the de novo origin of the mutation, but recurrence was then detected prenatally in a new pregnancy. This is the sixth family with malignant rhabdoid tumor predisposition syndrome with the recurrence of the same germ-line SMARCB1 mutation in the sibship but not in healthy parents, suggesting that gonadal mosaicism is a less rare event than supposed. The clinical outcome in our patient confirms previous data of poorer outcome in patients with rhabdoid tumor predisposition syndrome.

Expression analysis of the gene encoding for the U-box-type ubiquitin ligase UBE4A in human tissues.

The Ubiquitination Factor E4A gene (UBE4A) encodes for a U-box-type ubiquitin ligase, originally described as an E4 ubiquitination factor. UBE4A is a mammalian homolog of Saccharomyces cerevisiae Ufd2. The UBE4A gene has been mapped on the human chromosome region 11q23.3, a critical region involved in some specific cancers such as neuroblastoma. Northern blots analysis on foetal and adult human tissues revealed a single band of approximately 7.5 kb transcript most abundant in the heart, skeletal muscle and kidney. We generated a polyclonal antibody to UBE4A and performed immunoblot and immunohistochemical analysis. The UBE4A protein appeared as a single band of approximately 125 kDa. UBE4A was present in the skeletal muscle, kidney and liver; a faint band was visible in peripheral blood leukocytes and spleen. We did not reveal expression of UBE4A in whole brain, colon, lung and heart. At the cellular level, UBE4A results predominantly expressed in the nucleus and the cytoplasm of cortical neurons and liver and in the nucleus of tubular kidney cells. In the liver, the nucleus of similar cells appeared to be unstained or stained at different levels suggesting that UBE4A may have a cell cycle dependent expression or a role of in cell cycle control. In conclusion, our results show that UBE4A is expressed in different tissues in a pattern that seems to be dependent from cell type and cell cycle and that UBE4A might have a specific role in different biochemical processes other than ubiquitination, including growth or differentiation.

3'-UTR OLR1/LOX-1 gene polymorphism and endothelial dysfunction: molecular and vascular data in never-treated hypertensive patients.

Endothelial dysfunction represents an independent predictor for clinical events. Genetic background may promote deleterious alterations of endothelial physiology. The aim of the study was to investigate the relationship between the rs1050283 polymorphism in the 3'-UTR of OLR1/LOX-1 gene and endothelial dysfunction in 178 never-treated hypertensive patients and 36 healthy subjects. The rs1050283 C/T single nucleotide polymorphism was detected, by TaqMan allelic discrimination assay. The influence of polymorphism on gene transcription rate was tested in 12 heterozygous hypertensive patients, by using an allelic imbalance assay. Forearm blood flow (FBF) was measured during intra-arterial infusion of acetylcholine (ACh), and sodium nitroprusside at increasing doses. Analysis of endothelium-dependent and endothelium-independent vasodilatation was tested according to rs1050283 polymorphism. In hypertensive patients, ACh-stimulated FBF is significantly reduced in T allele carriers (P < 0.0001), even when the allelic imbalance assay indicates an overexpression of C allele. In healthy subjects, there is no significant difference for ACh-dependent vasodilatation among genotypic groups (P = 0.660). In essential hypertensive patients, the T allele of OLR1/LOX-1 gene is strongly associated with an impaired endothelium-dependent vasodilatation, a powerful predictor of cardiovascular events.