👤 Luydson Richardson Silva Vasconcelos

Alzheimer's disease (AD) is a progressive neurodegenerative disorder marked by cognitive decline, synaptic dysfunction, and mitochondrial abnormalities. Mitochondrial dynamics, especially the balance between fusion and fission processes regulated by proteins like mitofusin 2 (Mfn2) and dynamin-related protein 1 (Drp1), play critical roles in neuronal health. However, the relationship between mitochondrial dynamics and synaptic integrity, and cognitive deficits remains incompletely understood. This study aimed to investigate the alterations in Mfn2 and Drp1 expression and their association with synaptic protein levels and also behavioral outcomes in a rat model of AD. Thirty adult male Wistar rats were randomly assigned to control and AD groups. AD was induced through bilateral hippocampal injection of Aβ1-42. Behavioral assessments including the Morris Water Maze, Novel Object Recognition, and Y-maze were conducted to evaluate spatial learning and memory. On day 21 post-induction, gene expression of Drp1, Mfn2, PSD-95, synaptophysin, BDNF, Bax, and Bcl2 in the hippocampus and cortex was measured using real-time PCR. Oxidative stress markers (MDA, SOD, CAT) and inflammatory cytokines (NF-κB, IL-1β) were evaluated in serum using ELISA kits. Results showed significant downregulation of Mfn2 and synaptic proteins, with increased Drp1 and Bax expression in AD rats. These molecular changes were accompanied with increase of oxidative and inflammatory markers and altered cognitive performance. In conclusion, the findings suggest that disrupted mitochondrial dynamics contribute to synaptic loss and cognitive decline in AD. Targeting mitochondrial function and neuroinflammation may represent potential therapeutic targets for AD management. Show less

The pathogenesis of lipodystrophy in people living with HIV (PLWHIV) receiving antiretrovirals appears to be multifactorial and may involve genetic factors; however, it is not yet fully understood. We verified the association between single nucleotide polymorphisms in the APOC3-rs2854116, ESR2-rs3020450, HFE-rs1799945 and MMP1-rs1799750 genes and lipodystrophy and its subtypes in PLWHIV receiving antiretroviral. Design: cross-sectional study. Lipodystrophy definition was based on self-report. Genotyping of the polymorphisms was performed using real-time polymerase chain reaction. Lipodystrophy was reported in 204/404 participants (51%), being 89/204 with mixed lipodystrophy, 72/204 with lipohypertrophy, and 43/204 with lipoatrophy. There was no association between APOC3, HFE, and MMP1 polymorphisms and lipodystrophy. The frequency of AA genotype ( Participants with lipoatrophy had higher frequency of the AA genotype and the A allele of the ESR2-rs3020450 polymorphism. In addition, viral load >40 copies/mL and current use of zidovudine were associated with lipoatrophy, suggesting a potential involvement of this genetic variant in the pathogenesis of lipoatrophy in PLWHIV receiving antiretroviral. Show less

The recently developed therapeutic strategies have led to unprecedented improvements in the control of metastatic melanoma and in the survival of specific subgroups of patients. However, drug resistance, low response rates, and undesired side effects make these treatments not suitable or tolerable for all the patients, and chemotherapeutic treatments appear still indispensable, at least for subgroups of patients. New combinatory strategies are also under investigation as tailored treatments or salvage therapies, including combined treatments of immunotherapy with conventional chemotherapy. On this basis, and in consideration of the antineoplastic properties of ω-3 polyunsaturated fatty acids, we have here investigated the potential of these bioactive dietary factors to revert the resistance frequently exhibited by this form of cancer to cisplatin (CDDP, cis-diamminedichloroplatinum). We demonstrated that docosahexenoic acid (DHA, 22:6ω-3) sensitizes the cells to the CDDP-induced inhibition of cell growth and migration by reverting CDDP effects on DNA damage and ERCC1 expression, as well as on the DUSP6 and p-ERK expressions, which regulate ERCC1 activation upwardly. In line, DUSP6 gene silencing prevented the effect of DHA, confirming that DHA acted on the DUSP6/p-ERK/ERCC1 repair pathways to sensitize melanoma cells to the anticancer effect of CDDP. Similar effects were obtained also with eicosapentaenoic acid (20:5ω-3). Overall, our findings suggest that the combination of CDDP treatment with a dietary supplementation with ω-3 polyunsaturated fatty acids could potentially represent a new therapeutic strategy for overcoming CDDP resistance in metastatic melanoma. Show less

There is no published data comparing dietary management of urea cycle disorders (UCD) in different countries. Cross-sectional data from 41 European Inherited Metabolic Disorder (IMD) centres (17 UK, 6 France, 5 Germany, 4 Belgium, 4 Portugal, 2 Netherlands, 1 Denmark, 1 Italy, 1 Sweden) was collected by questionnaire describing management of patients with UCD on prescribed protein restricted diets. Data for 464 patients: N-acetylglutamate synthase (NAGS) deficiency, n=10; carbamoyl phosphate synthetase (CPS1) deficiency, n=29; ornithine transcarbamoylase (OTC) deficiency, n=214; citrullinaemia, n=108; argininosuccinic aciduria (ASA), n=80; arginase deficiency, n=23 was reported. The majority of patients (70%; n=327) were aged 0-16y and 30% (n=137) >16y. Prescribed median protein intake/kg body weight decreased with age with little variation between disorders. The UK tended to give more total protein than other European countries particularly in infancy. Supplements of essential amino acids (EAA) were prescribed for 38% [n=174] of the patients overall, but were given more commonly in arginase deficiency (74%), CPS (48%) and citrullinaemia (46%). Patients in Germany (64%), Portugal (67%) and Sweden (100%) were the most frequent users of EAA. Only 18% [n=84] of patients were prescribed tube feeds, most commonly for CPS (41%); and 21% [n=97] were prescribed oral energy supplements. Dietary treatment for UCD varies significantly between different conditions, and between and within European IMD centres. Further studies examining the outcome of treatment compared with the type of dietary therapy and nutritional support received are required. Show less