👤 Mafalda Raposo

Spinocerebellar ataxia type 3 (SCA3) is one of the most common dominantly inherited ataxias worldwide. Despite research advances, no approved disease-modifying treatment exists, and management focuses on symptom alleviation and functional capacity maximization. Symptomatic treatment guidelines are scarce, leaving decisions to physicians' discretion. The lack of studies on SCA3 symptom management hinders therapy standardization. The aim of this study was to investigate medication-usage patterns among SCA3 mutation carriers and controls included in the multicentric European Spinocerebellar Ataxia Type-3/Machado-Joseph Disease Initiative (ESMI) cohort. We conducted a retrospective cross-sectional analysis of the medication taken by ESMI participants enrolled in the study between 2016 and 2023. Medication being used at the most recent follow-up visit available was categorized according to the Anatomical Therapeutic Chemical system. Comparisons between groups were performed using nonparametric tests for continuous variables and Fisher's exact test for categorical variables. In addition, a retrospective longitudinal analysis was conducted to study the impact of medication subclasses on disease progression, using linear mixed-effects models adjusted for relevant covariates. A total of 474 participants were included, comprising 344 SCA3 mutation carriers and 130 controls. Compared with controls, SCA3 subjects took more vitamins, mineral supplements, muscle relaxants, and medications targeting the nervous system. Psychoanaleptics and vitamins were introduced early in the disease course, whereas most other subclasses were initiated in mid-to-late stages, coinciding with the onset of neurological symptoms. Substantial disparities in medication usage were observed across the study centers. None of the medication subclasses commonly used by patients with SCA3 showed a significant impact on disease progression. This is the first study to explore medication usage patterns in SCA3 mutation carriers. Our study provides a comprehensive overview of the medications administered in SCA3 and underscores the importance of collaborative efforts toward achieving standardized clinical practices in the management of this disease. Show less

Lipids are a principal component of drusen and are involved in the pathobiology of age-related macular degeneration (AMD). Nonhuman primates (NHPs) develop macular drusen and may provide insight into circulating or local lipids in AMD. We evaluated aged rhesus macaques by fundus photography, optical coherence tomography (OCT), and fundus autofluorescence, as well as measured fasting plasma glucose, total cholesterol, high- and low-density lipoproteins, triglycerides, and apolipoprotein (Apo) A1, B, CIII, and E. Retinal tissues were collected for electron microscopy and immunostained for oil red O, ApoE, and ApoB. Among 203 adult macaques (mean age 19.1 ± 3.1 years), 25 animals (12.1%) exhibited soft drusen with sub-RPE deposits, while 59 (28.6%) had yellow punctate dots that were mostly hyperautofluorescent without RPE elevation on OCT. Drusen prevalence increased with older age (P = 0.001) but not with plasma lipids (P > 0.05 for all), while the punctate dot phenotype was associated with older age (P = 0.014), higher fasting glucose (P = 0.023), low-density lipoprotein cholesterol (P = 0.022), and ApoB (P = 0.017). Ultrastructure revealed NHP drusen consisting of extracellular sub-RPE lipid particles, whereas punctate dots appeared to correspond to individual RPE cells with intracellular lipid vacuoles. Both sub-RPE and intra-RPE lipids of the two phenotypes contained neutral lipids and ApoE, while ApoE and ApoB appeared to be expressed in RPE. In rhesus macaques, soft drusen are extracellular lipid deposits associated with older age, while punctate dots are intracellular lipids linked to age, hyperglycemia, and hyperlipidemia, suggesting differential dysregulation of lipid transport in these NHP models of AMD. Show less

Neurodegenerative diseases are characterized by the structural and functional loss of neurons, which impacts populations worldwide. Enzymes such as acetylcholinesterase (AChE), beta-site APP cleaving enzyme-1 (BACE1), and glycogen synthase kinase 3-beta (GSK3β) are implicated in their progression. Therefore, developing compounds that inhibit these enzymes is relevant for treating these conditions. This study investigated the potential of quinoline analogs as multitarget enzyme inhibitors through in silico and in vitro assays. In silico analyses highlighted one of the derivatives as the most potent inhibitor for all proteins. In vitro assays confirmed that the quinoline derivatives modulated the activity of the three targets. The best derivative in silico also exhibited significant AChE inhibition of 94.6 %. For GSK3β and BACE1, four derivatives, with quinoline linked to the sulfonamide nitrogen, showed inhibition values above 40 %. Two of them demonstrated no cytotoxicity for human glioblastoma cell proliferation, and the most potent was noncytotoxic at 7.8 and 3.9 μg mL Show less

Susceptibility to obesity differs depending on the genetic background and housing temperatures. We have recently reported that CETP expressing female mice are leaner due to increased lipolysis, brown adipose tissue (BAT) activity, and body energy expenditure compared to nontransgenic (NTg) littermates under standard housing temperature (22°C). The aim of this study is to evaluate how CETP expression affects body temperature, composition, and metabolism during cold exposure (4°C) and thermoneutrality (30°C). When submitted to cold, CETP mice maintained rectal temperature, body weight, and food intake similarly to NTg mice along acute or chronic exposure to 4°C. The body oxygen consumption in response to an isoproterenol challenge was 21% higher at 22°C, and 41% higher after 7 days of cold exposure in CETP than in NTg mice. In addition, BAT biopsies from CETP mice showed reduced lipid content and increased basal oxygen consumption rates. Under thermoneutrality (30°C), when BAT activity is inhibited, CETP mice showed higher rectal and tail temperatures, increased food intake, and increased energy expenditure. Lean mass was elevated and fat mass reduced in CETP mice kept at 30°C. In this thermoneutral condition, soleus muscle, but not gastrocnemius or liver of CETP mice, showed increased mitochondrial respiration rates. These data indicate that CETP expression confers a greater capacity of elevating body metabolic rates at both cold exposure, through BAT activity, and at thermoneutrality, through increased muscle metabolism. Thus, the CETP expression levels in females should be considered as a new influence in the contexts of obesity and metabolic disorders propensity. Show less

Childhood obesity and associated comorbidities in adulthood are of great concern worldwide. Evidence highlights the importance of lactation in later disease development. In this sense, obese children are at great risk of developing adult obesity, insulin resistance, type 2 diabetes, and cardiovascular disease at adulthood. PPARα activation during lactation promotes the expression of key enzymes involved in lipid oxidation, and it was associated with reduced adiposity in children. Therefore, we hypothesized that an animal model of childhood obesity, small litter (SL), would lead to the development of obesity and metabolic dysfunction in adulthood, which could be prevented by postnatal PPARα agonism. Wistar dams had their litter reduced, leading to postnatal overfeeding and obesity early in life. SL male pups were treated with fenofibrate, an PPARα agonist, during lactation, from postnatal day (PND) 1 until weaning (PND21), to verify whether PPARα activation prevents the developmental programming at adulthood (PND120). Childhood obesity induced by postnatal overfeeding leads to decreased markers for oxidative metabolism during infancy, leading to increased visceral adiposity and oxidative stress, insulin resistance, hepatic microvesicular steatosis, and increased fibroblast growth factor 21 (Fgf21) expression, followed by decreased brown adipose tissue (BAT) sympathetic nerve activity and decreased Fgfr1 hypothalamic expression in adulthood. Agonist-induced PPARα activation during lactation mitigated the development of aforementioned alterations in adulthood. Postnatal fenofibrate treatment prevents the developmental programming of visceral obesity, liver-associated metabolic dysfunction and BAT autonomic sympathetic hypoactivity in an animal model of childhood obesity. Show less

The systemic function of CETP has been well characterized. CETP plasma activity reduces HDL cholesterol and thus increases the risk of atherosclerosis. Here, we investigated whether CETP expression modulate adiposity. Body adiposity and energy metabolism related assays and gene/protein expression were compared in CETP transgenic and non-transgenic mice and in hamsters treated with CETP neutralizing antibody. We found that transgenic mice expressing human CETP present less white adipose tissue mass and lower leptinemia than nontransgenic (NTg) littermates. No differences were found in physical activity, food intake, fat fecal excretion, lipogenesis or exogenous lipid accumulation in adipose depots. Nonetheless, adipose lipolysis rates and whole-body energy expenditure were elevated in CETP mice. In accordance, lipolysis-related gene expression and protein content were increased in visceral and brown adipose tissue (BAT). In addition, we verified increased BAT temperature and oxygen consumption. These results were confirmed in two other animal models: 1) hamsters treated with CETP neutralizing antibody and 2) an independent line of transgenic mice expressing simian CETP. These findings reveal a novel anti-adipogenic role for CETP. Show less

In this chapter, we present the major advances in CETP research since the detection, isolation, and characterization of its activity in the plasma of humans and several species. Since CETP is a major modulator of HDL plasma levels, the clinical importance of CETP activity was recognized very early. We describe the participation of CETP in reverse cholesterol transport, conflicting results in animal and human genetic studies, possible new functions of CETP, and the results of the main clinical trials on CETP inhibition. Despite major setbacks in clinical trials, the hypothesis that CETP inhibitors are anti-atherogenic in humans is still being tested. Show less

Dyggve-Melchior-Clausen dysplasia (DMC) is a rare inherited dwarfism with severe mental retardation due to mutations in the DYM gene which encodes Dymeclin, a 669-amino acid protein of yet unknown function. Despite a high conservation across species and several predicted transmembrane domains, Dymeclin could not be ascribed to any family of proteins. Here we show, using in situ hybridization, that DYM is widely expressed in human embryos, especially in the cortex, the hippocampus and the cerebellum. Both the endogenous and the recombinant protein fused to green fluorescent protein co-localized with Golgi apparatus markers. Electron microscopy revealed that Dymeclin associates with the Golgi apparatus and with transitional vesicles of the reticulum-Golgi interface. Moreover, permeabilization assays revealed that Dymeclin is not a transmembrane but a peripheral protein of the Golgi apparatus as it can be completely released from the Golgi after permeabilization of the plasma membrane. Time lapse confocal microscopy experiments on living cells further showed that the protein shuttles between the cytosol and the Golgi apparatus in a highly dynamic manner and recognizes specifically a subset of mature Golgi membranes. Finally, we found that DYM mutations associated with DMC result in mis-localization and subsequent degradation of Dymeclin. These data indicate that DMC results from a loss-of-function of Dymeclin, a novel peripheral membrane protein which shuttles rapidly between the cytosol and mature Golgi membranes and point out a role of Dymeclin in cellular trafficking. Show less