Mentalizing in Adolescents With and Without Prominent Borderline Features: Validation of the Reflective Functioning Questionnaire for Youths (RFQY) and an Investigation of the Factor Structure of Hypo- and Hypermentalizing.

The Reflective Functioning Questionnaire for Youths (RFQY) is a self-report measure of reflective functioning (RF) also referred to as mentalizing. Lower levels of RF are characteristic of a wide range of mental disorders and are especially relevant in the assessment of personality pathology. The goal of the current study is to examine the psychometric properties of a Danish translation of the RFQY and to corroborate previous research on the measure's ability to differentiate between adolescents with and without borderline personality disorder (BPD) features. 889 adolescents were administered the RFQY and divided into three subsamples: a community sample (n = 644), a clinical non-personality disorder sample (n = 64), and a BPD sample (n = 181). Construct validity was examined through bivariate correlations between RFQY and a dimensional assessment of borderline personality features. Analysis of variance (ANOVA) supported the utility of the RFQY to discriminate between adolescents with and without BPD features. Moreover, a two-factor structure based on previous research of the adult version of the RFQ was examined. A series of exploratory and confirmatory factor analyses yielded a two-factor structure corroborating previous research. Implications for prevention, assessment, and treatment are discussed along with methodological limitations and suggestions for future research.

Heparan sulfate proteoglycans present PCSK9 to the LDL receptor.

Coronary artery disease is the main cause of death worldwide and accelerated by increased plasma levels of cholesterol-rich low-density lipoprotein particles (LDL). Circulating PCSK9 contributes to coronary artery disease by inducing lysosomal degradation of the LDL receptor (LDLR) in the liver and thereby reducing LDL clearance. Here, we show that liver heparan sulfate proteoglycans are PCSK9 receptors and essential for PCSK9-induced LDLR degradation. The heparan sulfate-binding site is located in the PCSK9 prodomain and formed by surface-exposed basic residues interacting with trisulfated heparan sulfate disaccharide repeats. Accordingly, heparan sulfate mimetics and monoclonal antibodies directed against the heparan sulfate-binding site are potent PCSK9 inhibitors. We propose that heparan sulfate proteoglycans lining the hepatocyte surface capture PCSK9 and facilitates subsequent PCSK9:LDLR complex formation. Our findings provide new insights into LDL biology and show that targeting PCSK9 using heparan sulfate mimetics is a potential therapeutic strategy in coronary artery disease.PCSK9 interacts with LDL receptor, causing its degradation, and consequently reduces the clearance of LDL. Here, Gustafsen et al. show that PCSK9 interacts with heparan sulfate proteoglycans and this binding favors LDLR degradation. Pharmacological inhibition of this binding can be exploited as therapeutic intervention to lower LDL levels.