Evaluation of a Liquid Chromatography-Tandem Mass Spectrometry Method for the Analysis of Glucosylceramide and Galactosylceramide Isoforms in Cerebrospinal Fluid of Parkinson's Disease Patients.

Mutations in GBA1, encoding glucocerebrosidase beta 1 (GCase), are the most common genetic risk factor for Parkinson's disease (PD). GCase dysfunction leads to an accumulation of glucosylceramide (GluCer) substrates in different organs and fluids. Despite the challenges in quantifying GluCer isoforms in biological samples, their potential clinical interest as PD biomarkers justifies the development of robust assays. An extensively evaluated high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method for quantifying 14 GluCer and galactosylceramide (GalCer) isoforms in human cerebrospinal fluid (CSF) samples is presented. Sample pretreatment, HPLC, and MS/MS parameters were optimized. Evaluation was performed according to the recommendations of the Clinical and Laboratory Standards Institute and European Medicines Agency guidelines. Four 7-point calibration curves were generated, with a linearity interval from 2.5 to 200 nM (R2 ≥ 0.995). The limit of quantification was set at 5 nM. Between-run precision and accuracy were up to 12.5 and 9%, respectively. After method validation, we measured the levels of GluCer and GalCer isoforms in CSF human samples, including 6 healthy controls (HC), 22 idiopathic GBA1 wild-type PD (iPD) patients, and 5 GBA1-associated PD (PD-GBA) patients. GluCer/GalCer median ratios were found to be higher in the CSF of PD-GBA patients, particularly in severe GBA1 mutations, than those in iPD and HC. The observed trends in GluCer/GalCer ratios among groups provide novel information for the comprehensive analysis of sphingolipids as potential biomarkers of PD.

The Role of Chaperone-Mediated Autophagy in Tissue Homeostasis and Disease Pathogenesis.

Chaperone-mediated autophagy (CMA) is a selective proteolytic pathway in the lysosomes. Proteins are recognized one by one through the detection of a KFERQ motif or, at least, a KFERQ-like motif, by a heat shock cognate protein 70 (Hsc70), a molecular chaperone. CMA substrates are recognized and delivered to a lysosomal CMA receptor, lysosome-associated membrane protein 2A (LAMP-2A), the only limiting component of this pathway, and transported to the lysosomal lumen with the help of another resident chaperone HSp90. Since approximately 75% of proteins are reported to have canonical, phosphorylation-generated, or acetylation-generated KFERQ motifs, CMA maintains intracellular protein homeostasis and regulates specific functions in the cells in different tissues. CMA also regulates physiologic functions in different organs, and is then implicated in disease pathogenesis related to aging, cancer, and the central nervous and immune systems. In this minireview, we have summarized the most important findings on the role of CMA in tissue homeostasis and disease pathogenesis, updating the recent advances for this Special Issue.

Ajuste personal y conductas disruptivas en alumnado de primaria / Personal Adjustment and Disruptive Behaviors in Primary School Students

Resumen. Objetivo. Estudiar las relaciones entre variables de ajuste personal y las conductas disruptivas en un grupo de 136 alumnos y alumnas de primaria de entre 9 y 12 años. Método. Estudio de campo observacional, de metodología no experimental y transversal. Se utilizaron varios cuestionarios para medir la autoestima, la personalidad, el estrés y las competencias emocionales de los y las estudiantes, así como un cuestionario ad hoc elaborado para el registro de las conductas disruptivas. Resultados. Los resultados indican relaciones significativas positivas entre conductas disruptivas y estrés escolar, así como negativas con autoestima, estabilidad, competencia y comprensión emocional. Las diferencias son significativas según el género, manifestándose las conductas inadecuadas en menor medida en el caso de las niñas.

Abstract. Objective. This study analyses the relationships between personal adjustment and disruptive behaviors in a group of 136 primary school students between the ages of 9 and 12. Method. This field observation study used a non-experimental, cross-sectional methodology. Several questionnaires were used to measure students' self-esteem, personality, stress, and emotional competencies. Moreover, an ad hoc questionnaire was created to record disruptive behaviors. Results. The results indicate significant positive relationships between disruptive behaviors and school stress, as well as negative ones with self-esteem, stability, competence, and emotional understanding. The differences are significant according to gender, with inappropriate behaviors manifesting to a lesser extent in the case of girls.