Lipidomic signature of stroke recurrence after transient ischemic attack.

While TIA patients have transient symptoms, they should not be underestimated, as they could have an underlying pathology that may lead to a subsequent stroke: stroke recurrence (SR). Previously, it has been described the involvement of lipids in different vascular diseases. The aim of the current study was to perform a lipidomic analysis to identify differences in the lipidomic profile between patients with SR and patients without. Untargeted lipidomic analysis was performed in plasma samples of 460 consecutive TIA patients recruited < 24 h after the onset of symptoms. 37 (8%) patients suffered SR at 90 days. Lipidomic profiling disclosed 7 lipid species differentially expressed between groups: 5 triacylglycerides (TG), 1 diacylglyceride (DG), and 1 alkenyl-PE (plasmalogen) [specifically, TG(56:1), TG(63:0), TG(58:2), TG(50:5), TG(53:7, DG(38:5)) and PE(P-18:0/18:2)]. 6 of these 7 lipid species belonged to the glycerolipid family and a plasmalogen, pointing to bioenergetics pathways, as well as oxidative stress response. In this context, it was proposed the PE(P-18:0/18:2) as potential biomarker of SR condition.The observed changes in lipid patterns suggest pathophysiological mechanisms associated with lipid droplets metabolism and antioxidant protection that is translated to plasma level as consequence of a more intensive or high-risk ischemic condition related to SR.

Adverse effects of a SOD1-peptide immunotherapy on SOD1 G93A mouse slow model of amyotrophic lateral sclerosis.

Previous reports from our lab had shown that some anti-purinergic receptor P2X4 antibodies cross-reacted with misfolded forms of mutant Cu/Zn superoxide dismutase 1 (SOD1), linked to amyotrophic lateral sclerosis (ALS). Cross-reactivity could be caused by the abnormal exposure of an epitope located in the inner hydrophobic region of SOD1 that shared structural homology with the P2X4-immunizing peptide. We had previously raised antibodies against human SOD1 epitope mimicked by the P2X4 immunizing peptide. One of these antibodies, called AJ10, was able to recognize mutant/misfolded forms of ALS-linked mutant SOD1. Here, we used the AJ10 antigen as a vaccine to target neurotoxic species of mutant SOD1 in a slow mouse model of ALS. However, the obtained results showed no improvement in life span, disease onset or weight loss in treated animals; we observed an increased microglial neuroinflammatory response and high amounts of misfolded SOD1 accumulated within spinal cord neurons after AJ10 immunization. An increase of immunoglobulin G deposits was also found due to the treatment. Finally, a significantly worse clinical evolution was displayed by an impairment on motor function as a consequence of AJ10 peptide immunization.

Characterization of a mouse model overexpressing beta-site APP-cleaving enzyme 2 reveals a new role for BACE2.

BACE2 is homologous to BACE1, a beta-secretase that is involved in the amyloidogenic pathway of amyloid precursor protein (APP), and maps to the Down syndrome critical region of chromosome 21. Alzheimer disease neuropathology is common in Down syndrome patients at relatively early ages, and it has thus been speculated that BACE2 co-overexpression with APP would promote the early neurodegenerative phenotype. However, the in vivo function of BACE2 has not yet been elucidated. The aim of the present work has been to analyse the impact of in vivo BACE2 overexpression using a transgenic mouse model. Our results suggest that BACE2 is not involved in the amyloidogenic pathway, cognitive dysfunction or cholinergic degeneration. However, TgBACE2 animals showed increased anxiety-like behaviour along with increased numbers of noradrenergic neurones in locus coeruleus, thus suggesting an unexpected role of BACE2 overexpression.