👤 Mariana Rosolen Tavares

The brain is vulnerable to DNA damage and cardiometabolic risk. Yet, whether genetic variation in DNA repair interacts with cardiometabolic factors to explain cognitive variability remains unclear. Participants (n = 376,533) of white-British ancestry from the UK biobank with cognitive, neuroimaging, and whole-exome sequencing data were included. Six cognitive outcomes were assessed: fluid intelligence (FIQ), symbol-digit matching task (SDMT), visual matching (MATCH), trail making (TRAIL1 and TRAIL2), and prospective memory (PMEM). Seven brain regions of interest were assessed: total brain (TBV), grey matter (GMV), left and right white matter (LWM/RWM), left and right hippocampi (LHC/RHC), and white matter hyperintensities (WMH) volumes. A total of 3487 genetic variants across 39 DNA repair genes were tested. SNP and gene/gene-set level associations were tested using regression models adjusted for age, sex, APOE ε4, ancestry, and outcome-specific covariates. Genetic interactions with a multidimensional cardiometabolic risk index (CMRI), encompassing established risk factors, were assessed. We detected 107 genetic variants (mostly extremely rare) across 36 DNA repair genes associated at Bonferroni-significance (p ≤ 1.4 × 10 Show less

Lipoprotein(a) (Lp(a)) is a plasma lipoprotein with atherogenic, prothrombotic, and proinflammatory properties. Elevated Lp(a) levels are linked to the development of early atherosclerosis in childhood and contribute to a higher risk of cardiovascular disease (CVD) in adulthood. This study aimed to assess the clinical significance of Lp(a) levels in Portuguese pediatric patients who underwent serum Lp(a) testing as part of a lipid disorder screening prompted by obesity, hypercholesterolemia, and/or a family history of premature CVD. We also evaluated the correlation between Lp(a) levels and CVD risk factors. This cross-sectional retrospective study included 792 pediatric patients. Data on demographics, clinical history, body mass index, and laboratory values, including Lp(a), were collected. Lp(a) levels were categorized into 3 groups: <75 nmol/L, 75-125 nmol/L, and >125 nmol/L. A multivariate analysis was used to identify factors associated with Lp(a) ≥ 75 nmol/L. The most prevalent comorbidities in this sample were obesity and associated low-grade inflammation, each affecting at least one-third of participants. The median Lp(a) level was 31.80 nmol/L, with 9.1% and 21.6% of children having intermediate (75-125 nmol/L) and high (>125 nmol/L) Lp(a) levels, respectively. Higher total cholesterol, non-high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol (LDL-C) levels were correlated with elevated Lp(a) levels. The multivariate analysis identified an elevated LDL-C level as a predictor of a higher Lp(a) level. This study highlights the alarming prevalence of elevated Lp(a) levels in Portuguese pediatric patients who underwent serum Lp(a) testing due to lipid disorder screening, with >30% at intermediate/high CVD risk. As Lp(a) levels are mostly genetically determined and tend to persist into adulthood, these findings emphasize the importance of including Lp(a) screening in the cardiovascular risk assessment of children with CVD risk factors to enable timely prevention strategies for adultonset CVD. Show less

This work evaluated aspects of the immune response of BALB/c mice infected with Corynebacterium pseudotuberculosis (T1 and C57). The fifteen BALB/c mice were euthanized after 70 days of infection and morphologically evaluated, also analyzing the innate and adaptive immune responses. The C57 strain induced more pronounced morphological changes than the T1 strain. There was an increase in CD4 Show less

Vertical transmission of Zika virus (ZIKV) is associated with congenital malformations but the mechanism of pathogenesis remains unclear. Although host genetics appear to play a role, no genetic association study has yet been performed to evaluate this question. In order to investigate if maternal genetic variation is associated with Congenital Zika Syndrome (CZS), we conducted a case-control study in a cohort of Brazilian women infected with ZIKV during pregnancy. A total of 100 women who reported symptoms of zika during pregnancy were enrolled and tested for ZIKV. Among 52 women positive for ZIKV infection, 28 were classified as cases and 24 as controls based on the presence or absence of CZS in their infants. Variations in the coding region of 205 candidate genes involved in cAMP signaling or immune response were assessed by high throughput sequencing and tested for association with development of CZS. From the 817 single nucleotide variations (SNVs) included in association analyses, 22 SNVs in 17 genes were associated with CZS under an additive model (alpha = 0.05). Variations c.319T>C (rs11676272) and c.1297G>A, located at ADCY3 and ADCY7 genes showed the most prominent effect. The association of ADCY3 and ADCY7 genes was confirmed using a Sequence Kernel Association Test to assess the joint effect of common and rare variations, and results were statistically significant after adjustment for multiple comparisons (P < 0.002). These results suggest that maternal ADCY genes contribute to ZIKV pathogenicity and influence the outcome of CZS, being promising candidates for further replication studies and functional analysis. Show less

Amyloidosis is a group of disorders characterised by the accumulation of extracellular deposits of insoluble protein aggregates. Clinical management depends on the accurate identification of the amyloid precursor and underlying cause. We describe a rare case of apolipoprotein A-IV cardiac amyloidosis, the diagnosis of which required mass spectrometry-based proteomic analysis. To be able to perform the differential diagnosis of cardiac amyloidosis subtypes using imaging methods, analytical results and tissue analysis.To recognise the added value of mass spectrometry (MS)-based proteomic analysis. Show less

The mitogen-activated kinase phosphatase-3 (MKP-3) has gained great importance in the scientific community by acting as a regulator of the cell cycle through dephosphorylation of FoxO1, an important transcription factor involved in the insulin intracellular signaling cascade. When dephosphorylated and translocated to the nuclei, FoxO1 can promote the transcription of orexigenic neuropeptides (NPY/AgRP) in the hypothalamus, whereas insulin signaling is responsible for the disruption of this process. However, it is not understood if the hypothalamic activation of MKP-3 affects FoxO1 phosphorylation, and we hypothesized that MKP-3 overexpression reduces the capacity of the insulin signal to phosphorylate FoxO1. In the present study, we overexpressed the DUSP6 gene through an injection of adenovirus directly into the hypothalamic third ventricle of Swiss mice. The colocalization of the adenovirus was confirmed by the immunofluorescence assay. Then, MKP-3 overexpression resulted in a significant reduction of hypothalamic FoxO1 phosphorylation after insulin stimulation. This effect was independent of changes in Akt phosphorylation. Thus, the role of MKP-3 in the hypothalamus is closely associated with FoxO1 dephosphorylation and may provide a potential therapeutic target against hypothalamic disorders related to obesity and unbalanced food intake control. Show less

High throughput sequencing technologies have revolutionized the identification of mutations responsible for genetic diseases such as hypertrophic cardiomyopathy (HCM). However, approximately 50% of individuals with a clinical diagnosis of HCM have no causal mutation identified. This may be due to the presence of pathogenic mutations located deep within the introns, which are not detected by conventional sequencing analysis restricted to exons and exon-intron boundaries. The aim of this study was to develop a whole-gene sequencing strategy to prioritize deep intronic variants that may play a role in HCM pathogenesis. The full genomic DNA sequence of 26 genes previously associated with HCM was analysed in 16 unrelated patients. We identified likely pathogenic deep intronic variants in VCL, PRKAG2 and TTN genes. These variants, which are predicted to act through disruption of either splicing or transcription factor binding sites, are 3-fold more frequent in our cohort of probands than in normal European populations. Moreover, we found a patient that is compound heterozygous for a splice site mutation in MYBPC3 and the deep intronic VCL variant. Analysis of family members revealed that carriers of the MYBPC3 mutation alone do not manifest the disease, while family members that are compound heterozygous are clinically affected. This study provides a framework for scrutinizing variation along the complete intronic sequence of HCM-associated genes and prioritizing candidates for mechanistic and functional analysis. Our data suggest that deep intronic variation contributes to HCM phenotype. Show less