Prognostic Value of PCSK9 Levels in Premenopausal Women at Risk of Breast Cancer-Evidence from a 17-Year Follow-Up Study.

BACKGROUND AND AIM: The involvement of cholesterol in cancer development remains a topic of debate, and its association with breast cancer has yet to be consistently demonstrated. Considering that circulating cholesterol levels depend on several concomitant processes, we tested the liability of plasma levels of proprotein convertase subtilisin/kexin type 9 (PCSK9), one of the key regulators of cholesterol levels, as a prognostic biomarker in the context of breast neoplastic events. METHODS: Within a prospective randomized breast cancer prevention trial we measured baseline plasma levels of PCSK9. A total of 235 at-risk premenopausal women were randomized and followed up for 17 years. Participants enrolled in this placebo-controlled, phase II, double-blind trial were randomly assigned to receive either tamoxifen 5 mg/d or fenretinide 200 mg/d, both agents, or placebo for 2 years. The associations with breast cancer events were evaluated through competing risk and Cox regression survival models, adjusted for randomization strata (5-year Gail risk ≥ 1.3% vs. intraepithelial neoplasia or small invasive breast cancer of favorable prognosis), age, and treatment allocation. PCSK9 associations with biomarkers linked to breast cancer risk were assessed on blood samples collected at baseline. RESULTS: The plasmatic PCSK9 median and interquartile range were 207 ng/mL and 170-252 ng/mL, respectively. Over a median follow-up period of 17 years and 89 breast neoplastic events, disease-free survival curves showed a hazard ratio of 1.002 (95% CI: 0.999-1.005, p = 0.22) for women with PCSK9 plasma levels ≥ 207 ng/mL compared to women with levels below 207 ng/mL. No differences between randomization strata were observed. We found a negative correlation between PCSK9 and estradiol (r = -0.305), maintained even after partial adjustment for BMI and age (r = -0.287). Cholesterol (r = 0.266), LDL-C (r = 0.207), non-HDL-C (r = 0.246), remnant cholesterol (r = 0.233), and triglycerides (r = 0.233) also correlated with PCSK9. CONCLUSIONS: In premenopausal women at risk of early-stage breast cancer, PCSK9 did not appear to have a role as a prognostic biomarker of breast neoplastic events. Larger studies are warranted investigating patients in different settings.

Exploring the role of epicardial adipose-tissue-derived extracellular vesicles in cardiovascular diseases.

Epicardial adipose tissue (EAT) is a fat depot located between the myocardium and the visceral layer of the epicardium, which, owing to its location, can influence surrounding tissues and can act as a local transducer of systemic inflammation. The mechanisms upon which such influence depends on are however unclear. Given the role EAT undoubtedly has in the scheme of cardiovascular diseases (CVDs), understanding the impact of its cellular components is of upmost importance. Extracellular vesicles (EVs) constitute promising candidates to fill the gap in the knowledge concerning the unexplored mechanisms through which EAT promotes onset and progression of CVDs. Owing to their ability of transporting active biomolecules, EAT-derived EVs have been reported to be actively involved in the pathogenesis of ischemia/reperfusion injury, coronary atherosclerosis, heart failure, and atrial fibrillation. Exploring the precise functions EVs exert in this context may aid in connecting the dots between EAT and CVDs.

Circulating PCSK9 as a prognostic biomarker of cardiovascular events in individuals with type 2 diabetes: evidence from a 16.8-year follow-up study.

BACKGROUND: Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of morbidity and mortality, being twofold to fourfold more common in patients with type 2 diabetes mellitus (T2DM) than in individuals without diabetes. However, despite this decade-old knowledge, the identification of a specific prognostic risk biomarker remains particularly challenging. METHODS: Taking advantage of a large sample of Caucasian patients (n = 529) with a diagnosis of T2DM followed for a median of 16.8 years, the present study was aimed at testing the hypothesis that fasting serum proprotein convertase subtilisin/kexin type 9 (PCSK9) levels could be prognostic for major adverse cardiovascular events (MACE) and all-cause mortality. RESULTS: Median levels of PCSK9 were 259.8 ng/mL, being higher in women compared to men and increasing even more in the presence of a complication (e.g., diabetic kidney disease). PCSK9 positively correlated with markers of blood glucose homeostasis (e.g., HbA1c, fasting insulin and HOMA-IR) and the atherogenic lipid profile (e.g., non-HDL-C, apoB and remnant cholesterol). Serum PCSK9 predicted new-onset of MACE, either fatal or non-fatal, only in women (Odds Ratio: 2.26, 95% CI 1.12-4.58) and all-cause mortality only in men (Hazard Ratio: 1.79, 95% CI 1.13-2.82). CONCLUSIONS: Considering that up to two-thirds of individuals with T2DM develop ASCVD in their lifetime, the assessment of circulating PCSK9 levels can be envisioned within the context of a biomarker-based strategy of risk stratification. However, the sex difference found highlights an urgent need to develop sex-specific risk assessment strategies. TRIAL REGISTRATION: It is a retrospective study.

PCSK9 Confers Inflammatory Properties to Extracellular Vesicles Released by Vascular Smooth Muscle Cells.

Vascular smooth muscle cells (VSMCs) are key participants in both early- and late-stage atherosclerosis and influence neighbouring cells possibly by means of bioactive molecules, some of which are packed into extracellular vesicles (EVs). Proprotein convertase subtilisin/kexin type 9 (PCSK9) is expressed and secreted by VSMCs. This study aimed to unravel the role of PCSK9 on VSMCs-derived EVs in terms of content and functionality. EVs were isolated from human VSMCs overexpressing human PCSK9 (VSMCPCSK9-EVs) and tested on endothelial cells, monocytes, macrophages and in a model of zebrafish embryos. Compared to EVs released from wild-type VSMCs, VSMCPCSK9-EVs caused a rise in the expression of adhesion molecules in endothelial cells and of pro-inflammatory cytokines in monocytes. These acquired an increased migratory capacity, a reduced oxidative phosphorylation and secreted proteins involved in immune response and immune effector processes. Concerning macrophages, VSMCPCSK9-EVs enhanced inflammatory milieu and uptake of oxidized low-density lipoproteins, whereas the migratory capacity was reduced. When injected into zebrafish embryos, VSMCPCSK9-EVs favoured the recruitment of macrophages toward the site of injection. The results of the present study provide evidence that PCSK9 plays an inflammatory role by means of EVs, at least by those derived from smooth muscle cells of vascular origin.

Synovial Fluid-Derived Extracellular Vesicles of Patients with Arthritides Contribute to Hippocampal Synaptic Dysfunctions and Increase with Mood Disorders Severity in Humans.

Arthritides are a highly heterogeneous group of disorders that include two major clinical entities, localized joint disorders such as osteoarthritis (OA) and systemic autoimmune-driven diseases such as rheumatoid arthritis (RA). Arthritides are characterized by chronic debilitating musculoskeletal conditions and systemic chronic inflammation. Poor mental health is also one of the most common comorbidities of arthritides. Depressive symptoms which are most prevalent, negatively impact patient global assessment diminishing the probability of achieving the target of clinical remission. Here, we investigated new insights into mechanisms that link different joint disorders to poor mental health, and to this issue, we explored the action of the synovial fluid-derived extracellular vesicles (EVs) on neuronal function. Our data show that the exposure of neurons to different concentrations of EVs derived from both RA and OA synovial fluids (RA-EVs and OA-EVs) leads to increased excitatory synaptic transmission but acts on specific modifications on excitatory or inhibitory synapses, as evidenced by electrophysiological and confocal experiments carried out in hippocampal cultures. The treatment of neurons with EVs membrane is also responsible for generating similar effects to those found with intact EVs suggesting that changes in neuronal ability arise upon EVs membrane molecules' interactions with neurons. In humans with arthritides, we found that nearly half of patients (37.5%) showed clinically significant psychiatric symptoms (CGIs score ≥ 3), and at least mild anxiety (HAM-A ≥ 7) or depression (MADRS and HAM-D ≥ 7); interestingly, these individuals revealed an increased concentration of synovial EVs. In conclusion, our data showing opposite changes at the excitatory and inhibitory levels in neurons treated with OA- and RA-EVs, lay the scientific basis for personalized medicine in OA and RA patients, and identify EVs as new potential actionable biomarkers in patients with OA/RA with poor mental health.

Managing folate deficiency implies filling the gap between laboratory and clinical assessment.

The characterization of folate status in subjects at risk of deficiency and with altered vitamin homeostasis is crucial to endorse preventive intervention health policies, especially in developed countries. Several physiological changes (i.e. pregnancy), clinical situations and diseases have been associated to increased requirement, impaired intake and absorption of folate. However clinical practice guidelines (CPG) endorse folic acid supplementation generally discarding the use of its determination in serum to assess the risk of deficiency and/or its concentration at baseline. Poor confidence on the diagnostic accuracy of serum folate assays still persists in the current CPGs although recent standardization efforts have greatly improved inter-method variability and precision. In this review we critically appraise the methodological issues concerning laboratory folate determination and the evidence on the potential adverse effects of folic acid exposure. The final aim is to build a sound background to promote serum folate-based cost-effective health care policies by optimizing folic acid supplementation in subjects at risk of deficiency and with altered folate homeostasis. Our first result was to adjust in relation to current serum folate assays the thresholds reported by CPGs as index of folate status, defined on the association with metabolic and hematologic indicators. We identify a statistically significant difference between the estimated thresholds and accordingly show that the assessment of folate status actually changes in relation to the assay employed. The use of the method-dependent thresholds here reported may pragmatically endorse the stewardship of folic acid supplementation in clinical practice and increase the cost-effectiveness of health care policies.