👤 Alejandro Castellanos

Air pollution exposure is associated with increased cardiovascular morbidity and mortality worldwide. Previous studies provide a causal relationship between exposure to particulate matter (PM) and atherosclerosis development. We have previously demonstrated increased aortic atherosclerosis and adverse metabolic effects in hyperlipidemic mice exposed to ambient ultrafine PM. However, the underlying mechanisms by which ambient PM promotes systemic effects leading to worsened atherosclerosis remain unknown. We have recently shown that the gut microbiota composition was altered in mice exposed to re-aerosolized PM in the ultrafine-size range for 10 weeks. We hypothesized that sub-chronic exposure to ultrafine PM induces gut dysbiosis in association with systemic prooxidative effects and atherosclerotic lesion development. Male apolipoprotein E knockout (ApoE Show less

Familial chylomicronemia syndrome (FCS) is an ultra-rare disorder associated with pathogenic variants in genes implicated in chylomicron metabolism such as LPL, APOA5, APOC2, GPIHBP1, and LMF1. Patients with FCS have severe hypertriglyceridemia complicated with recurrent episodes of pancreatitis. Volanesorsen is a treatment option for such patients. However, this treatment is not approved or available in all countries. To present the real-life evidence of clinical response to volanesorsen in patients with FCS in Colombia. All patients treated with volanesorsen in Colombia as of June 25, 2024, were included. After informed consent, relevant clinical and laboratory data were obtained through review of clinical charts and records from the volanesorsen patient support program. Ten patients with FCS and treated with volanesorsen were included. Most cases were caused by variants in LPL. A total of 90% of cases had at least 1 episode of pancreatis, the mean number of pancreatitis episodes was 5. Median follow-up was 56.5 weeks (IQR 38.3-82.3). The median highest plasma triglyceride (TG) level before treatment was 3111 mg/dL (IQR 1738-3810), while the median lowest TG level after treatment was 493 mg/dL (IQR 147-812). The mean percent decreases in plasma TG at months 1, 3, 6, and 12 were 53.6%, 59.7%, 51.5%, and 40.5%, respectively. There were no new pancreatitis episodes after initiation of volanesorsen treatment. Side effects were consistent with those reported in clinical trials. Real-life data of volanesorsen treatment for FCS in Colombia demonstrate efficacy and safety similar to pivotal clinical trials. Show less

Megalencephalic Leukoencephalopathy with subcortical Cysts (MLC) is a type of vacuolating leukodystrophy, which is mainly caused by mutations in MLC1 or GLIALCAM. The two MLC-causing genes encode for membrane proteins of yet unknown function that have been linked to the regulation of different chloride channels such as the ClC-2 and VRAC. To gain insight into the role of MLC proteins, we have determined the brain GlialCAM interacting proteome. The proteome includes different transporters and ion channels known to be involved in the regulation of brain homeostasis, proteins related to adhesion or signaling as several G protein-coupled receptors (GPCRs), including the orphan GPRC5B and the proposed prosaposin receptor GPR37L1. Focusing on these two GPCRs, we could validate that they interact directly with MLC proteins. The inactivation of Gpr37l1 in mice upregulated MLC proteins without altering their localization. Conversely, a reduction of GPRC5B levels in primary astrocytes downregulated MLC proteins, leading to an impaired activation of ClC-2 and VRAC. The interaction between the GPCRs and MLC1 was dynamically regulated upon changes in the osmolarity or potassium concentration. We propose that GlialCAM and MLC1 associate with different integral membrane proteins modulating their functions and acting as a recruitment site for various signaling components as the GPCRs identified here. We hypothesized that the GlialCAM/MLC1 complex is working as an adhesion molecule coupled to a tetraspanin-like molecule performing regulatory effects through direct binding or influencing signal transduction events. Show less

Ischemic stroke is among the leading causes of adult disability. Part of the variability in functional outcome after stroke has been attributed to genetic factors but no locus has been consistently associated with stroke outcome. Our aim was to identify genetic loci influencing the recovery process using accurate phenotyping to produce the largest GWAS (genome-wide association study) in ischemic stroke recovery to date. A 12-cohort, 2-phase (discovery-replication and joint) meta-analysis of GWAS included anterior-territory and previously independent ischemic stroke cases. Functional outcome was recorded using 3-month modified Rankin Scale. Analyses were adjusted for confounders such as discharge National Institutes of Health Stroke Scale. A gene-based burden test was performed. The discovery phase (n=1225) was followed by open (n=2482) and stringent joint-analyses (n=1791). Those cohorts with modified Rankin Scale recorded at time points other than 3-month or incomplete data on previous functional status were excluded in the stringent analyses. Novel variants in PATJ (Pals1-associated tight junction) gene were associated with worse functional outcome at 3-month after stroke. The top variant was rs76221407 (G allele, β=0.40, P=1.70×10 Our results identify a set of common variants in PATJ gene associated with 3-month functional outcome at genome-wide significance level. Future studies should examine the role of PATJ in stroke recovery and consider stringent phenotyping to enrich the information captured to unveil additional stroke outcome loci. Show less