👤 Francisca Saraiva

Lipoprotein(a) [Lp(a)] is recognized as an independent risk factor for coronary disease owing to its atherogenic, proinflammatory, and prothrombotic properties. Current guidelines recommend a single measurement in adults to refine cardiovascular (CV) risk assessment. We aimed to characterize Lp(a) levels in patients with acute coronary syndrome (ACS) and explore associations with sex, age, comorbidities, and traditional cardiovascular risk factors. We conducted a cross-sectional study of patients with ACS admitted to our center between January 2022 and December 2023, with Lp(a) measured at admission. Patients were stratified into two groups: Lp(a) >100 nmol/L and ≤100 nmol/L. Demographic and clinical data, including traditional cardiovascular risk factors (dyslipidemia, diabetes mellitus, arterial hypertension, smoking, and obesity), were collected from hospital records. Chi-square and independent t or Mann-Whitney U tests were used to compare categorical and quantitative variables; linear regression analysis assessed associations between continuous Lp(a) values and independent variables. Among 903 patients admitted with ACS during the study period, Lp(a) was measured in 388 (42%). Median Lp(a) level was 62.0 [18.4, 153.8] nmol/L. Of these, 38.7% had Lp(a) >100 nmol/L. Women had higher Lp(a) than men (p-trend=0.014). Lp(a) levels were similar across traditional cardiovascular risk factors categories. Among patients without traditional cardiovascular risk factors, women also had higher Lp(a) than men (p=0.003). Elevated Lp(a) was associated with history of coronary artery disease (p-trend=0.003) and with treatment with high-intensity statins alone (p-trend=0.032) or in combination with ezetimibe (p-trend=0.014). Lp(a) levels showed a heterogeneous distribution and was not associated with traditional cardiovascular risk factors or other lipid parameters. This reinforces Lp(a) as an independent risk factor, supporting active screening in patients with ACS, particularly in women not affected by traditional cardiovascular risk factors. Show less

Chronic exposure to second-hand smoke (SHS) contributes to the development of health issues, including cancer and cardiovascular diseases. Molecular mechanisms underlying SHS-related diseases remain poorly understood, highlighting the need for reliable risk assessment biomarkers. Herein, we demonstrate that the plasma proteome of individuals exposed to SHS undergoes significant modulation. Butyrylcholinesterase (BChE) and Vitamin D-binding protein (GC) that are involved in the physiological response to circulating toxic substances, as well as key mediators of systemic inflammation, including Complement C1r subcomponent (C1R), Complement C1q subcomponent subunit C (C1QC), Histidine-rich glycoprotein (HRG), and Vitamin K-dependent protein S (PROS1), were found to be significantly modulated in SHS-exposed individuals. Moreover, strong indicators of a pro-atherothrombotic response such Apolipoprotein A-IV (APOA4) and Alpha-2-antiplasmin (SERPINF2), were also differentially expressed. These findings provide novel insights into the biological pathways linking SHS-exposure to cardiovascular risks, and suggest a panel of candidate proteins with potential utility as SHS-risk assessment biomarkers. 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

What is the contribution of genetic defects in Portuguese patients with congenital hypogonadotropic hypogonadism (CHH)? Approximately one-third of patients with CHH were found to have a genetic cause for their disorder, with causal pathogenic and likely pathogenic germline variants distributed among 10 different genes; cases of oligogenic inheritance were also included. CHH is a rare and genetically heterogeneous disorder characterized by deficient production, secretion, or action of GnRH, LH, and FSH, resulting in delayed or absent puberty, and infertility. Genetic screening was performed on a cohort of 81 Portuguese patients with CHH (36 with Kallmann syndrome and 45 with normosmic hypogonadotropic hypogonadism) and 263 unaffected controls. The genetic analysis was performed by whole-exome sequencing followed by the analysis of a virtual panel of 169 CHH-associated genes. The main outcome measures were non-synonymous rare sequence variants (population allele frequency <0.01) classified as pathogenic, likely pathogenic, and variants of uncertain significance (VUS). A genetic cause was identified in 29.6% of patients. Causal pathogenic and likely pathogenic variants were distributed among 10 of the analysed genes. The most frequently implicated genes were N/A. The identification of a large number of VUS presents challenges in interpretation and these may require reclassification as more evidence becomes available. Non-coding and copy number variants were not studied. Functional studies of the variants were not undertaken. This study highlights the genetic heterogeneity of CHH and identified several novel variants that expand the mutational spectrum of the disorder. A significant proportion of patients remained without a genetic diagnosis, suggesting the involvement of additional genetic, epigenetic, or environmental factors. The high frequency of VUS underscores the importance of cautious variant interpretation. These findings contribute to the understanding of the genetic architecture of CHH and emphasize the need for further studies to elucidate the underlying mechanisms and identify additional causes of CHH. This research was funded by the Portuguese Foundation for Science and Technology (grant numbers PTDC/SAU-GMG/098419/2008, UIDB/00709/2020, CEECINST/00016/2021/CP2828/CT0002, and 2020.04924.BD) and by Sidra Medicine-a member of the Qatar Foundation (grant number SDR400038). The authors declare no competing interests. Show less

Genome sequencing efforts have led to the discovery of tens of millions of protein missense variants found in the human population with the majority of these having no annotated role and some likely contributing to trait variation and disease. Sequence-based artificial intelligence approaches have become highly accurate at predicting variants that are detrimental to the function of proteins but they do not inform on mechanisms of disruption. Here we combined sequence and structure-based methods to perform proteome-wide prediction of deleterious variants with information on their impact on protein stability, protein-protein interactions and small-molecule binding pockets. AlphaFold2 structures were used to predict approximately 100,000 small-molecule binding pockets and stability changes for over 200 million variants. To inform on protein-protein interfaces we used AlphaFold2 to predict structures for nearly 500,000 protein complexes. We illustrate the value of mechanism-aware variant effect predictions to study the relation between protein stability and abundance and the structural properties of interfaces underlying Show less

Macrophages are highly plastic cells, responding to diverse environmental stimuli to acquire different functional phenotypes. Signaling through MAPKs has been reported to regulate the differentiation of macrophages, but the role of ERK5 in IL-4-mediated M2 macrophage differentiation is still unclear. Here, we showed that the ERK5 signaling pathway plays a critical role in IL-4-induced M2 macrophage differentiation. Pharmacologic inhibition of MEK5, an upstream activator of ERK5, markedly reduced the expression of classical M2 markers, such as Arg-1, Ym-1, and Fizz-1, as well as the production of M2-related chemokines and cytokines, CCL22, CCL17, and IGF-1 in IL-4-stimulated macrophages. Moreover, pharmacologic inhibition of ERK5 also decreased the expression of several M2 markers induced by IL-4. In accordance, myeloid cell-specific Erk5 depletion (Erk5 Show less

Left ventricular noncompaction (LVNC) is a rare and potentially progressive cardiomyopathy, characterized by the persistence of multiple trabeculations and deep intratrabecular recesses in the ventricular myocardium. Although two-dimensional and color Doppler echocardiography are the most useful diagnostic modalities, cardiac magnetic resonance imaging has proved to have high sensitivity and specificity in the diagnosis of this anomaly. To characterize the clinical and imaging features of LVNC in a pediatric population and to assess their evolution. We performed a retrospective chart review of five pediatric patients with LVNC, followed at Coimbra Pediatric Hospital between January 1999 and December 2007. Median age at presentation was five months (ranging from one day to 13 years), and they were mainly male (1.5:1). Two of the children had a family history of sudden death. In one case the clinical presentation was cardiac arrest due to ventricular fibrillation and in three others, congestive cardiac failure. None of the five cases had associated congenital cardiac anomalies. Involvement of the ventricular apical region was found in all cases. Four children additionally had ventricular dysfunction which improved with diuretic and vasodilator therapy. Mean follow-up was 34 months, ranging from six months to seven years. In one case a change in the morphological phenotype was noted, from a dilated to a hypertrophic form. In this case and in the child's father a mutation in the MYBPC3 gene was identified, which is associated with hypertrophic cardiomyopathy. No thromboembolic phenomena or deaths occurred during the study period. In the pediatric population, congestive cardiac failure is the most common clinical presentation of LVNC, which can coexist with other cardiomyopathies, particularly dilated and hypertrophic forms. The sample presented in this analysis is statistically non-significant due to its limited size and the authors highlight the need for larger prospective studies in the pediatric population in order to clarify this disease and its diagnostic criteria. Show less

Familial amyloidotic polyneuropathy (FAP) is a neurodegenerative disorder characterized by the extracellular deposition of transthyretin (TTR), especially in the PNS. Given the invasiveness of nerve biopsy, salivary glands (SG) from FAP patients were used previously in microarray analysis; mitogen-activated protein (MAP) kinase phosphatase 1 (MKP-1) was down-regulated in FAP. Results were validated by RT-PCR and immunohistochemistry both in SG and in nerve biopsies of different stages of disease progression. MKP-3 was also down-regulated in FAP SG biopsies. Given the relationship between MKPs and MAPKs, the latter were investigated. Only extracellular signal-regulated kinases 1/2 (ERK1/2) displayed increased activation in FAP SG and nerves. ERK1/2 kinase (MEK1/2) activation was also up-regulated in FAP nerves. In addition, an FAP transgenic mouse model revealed increased ERK1/2 activation in peripheral nerve affected with TTR deposition when compared to control animals. Cultured rat Schwannoma cell line treatment with TTR aggregates stimulated ERK1/2 activation, which was partially mediated by the receptor for advanced glycation end-products (RAGE). Moreover, caspase-3 activation triggered by TTR aggregates was abrogated by U0126, a MEK1/2 inhibitor, indicating that ERK1/2 activation is essential for TTR aggregates-induced cytotoxicity. Taken together, these data suggest that abnormally sustained activation of ERK in FAP may represent an early signaling cascade leading to neurodegeneration. Show less