RESUMO
Friedreich ataxia is a hereditary neurodegenerative disorder resulting from reduced levels of the protein frataxin due to an expanded GAA repeat in the FXN gene. This deficiency causes progressive degeneration of specific neuronal populations in the cerebellum and the consequent loss of movement coordination and equilibrium, which are some of the main symptoms observed in affected individuals. Like in other neurodegenerative diseases, previous studies suggest that glial cells could be involved in the neurodegenerative process and disease progression in patients with Friedreich ataxia. In this work, we followed and characterized the progression of changes in the cerebellar cortex in the latest version of Friedreich ataxia humanized mouse model, YG8-800 (Fxnnull:YG8s(GAA)>800), which carries a human FXN transgene containing >800 GAA repeats. Comparative analyses of behavioral, histopathological, and biochemical parameters were conducted between the control strain Y47R and YG8-800 mice at different time points. Our findings revealed that YG8-800 mice exhibit an ataxic phenotype characterized by poor motor coordination, decreased body weight, cerebellar atrophy, neuronal loss, and changes in synaptic proteins. Additionally, early activation of glial cells, predominantly astrocytes and microglia, was observed preceding neuronal degeneration, as was increased expression of key proinflammatory cytokines and downregulation of neurotrophic factors. Together, our results show that the YG8-800 mouse model exhibits a stronger phenotype than previous experimental murine models, reliably recapitulating some of the features observed in humans. Accordingly, this humanized model could represent a valuable tool for studying Friedreich ataxia molecular disease mechanisms and for preclinical evaluation of possible therapies.
RESUMO
Plasma levels of endocannabinoids (eCBs) are very dynamic and variable in different circumstances and pathologies. The aim of the study was to determine the levels of the main eCBs and N-acylethanolamines (NAEs) in COVID-19 patients during the acute and post-acute phase of SARS-CoV-2 infection. Samples collected before December 31, 2020 were used for the determination of circulating eCB levels by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The association between plasma eCB measurements and biochemical and hematological parameters, as well as serum IL-6 levels, was evaluated. Samples of 64 individuals were analysed, n = 18 healthy donors, n = 30 acute, and n = 16 post-acute patients. Plasma levels of 2-arachidonoylglycerol (2-AG), were significantly elevated in COVID-19 patients when compared to healthy individuals. Plasma N-palmitoylethanolamide (PEA) and N-arachidonoylethanolamide (AEA) levels were found to be decreased in post-acute patient samples. These results suggest that 2-AG plays an important role in the inflammatory cascade in COVID-19 disease; in addition, eCBs might be involved in the post-acute pathogenesis of COVID-19. This study provides evidence of altered levels of circulating eCBs as a consequence of SARS-CoV-2 infection.
Assuntos
Ácidos Araquidônicos , COVID-19 , Endocanabinoides , Glicerídeos , Inflamação , SARS-CoV-2 , Humanos , Endocanabinoides/sangue , COVID-19/sangue , COVID-19/virologia , Masculino , Feminino , Pessoa de Meia-Idade , Adulto , Ácidos Araquidônicos/sangue , Inflamação/sangue , Glicerídeos/sangue , Alcamidas Poli-Insaturadas/sangue , Etanolaminas/sangue , Idoso , Interleucina-6/sangue , Ácidos Palmíticos/sangue , Espectrometria de Massas em Tandem , Amidas , Cromatografia LíquidaRESUMO
Background: Single anastomosis duodenoileal bypass with sleeve gastrectomy (SADI-S) is a predominantly malabsorptive technique that has shown excellent results in morbid obese patients. The aim of this study is to establish a rodent model modifying the SADI-S technique by performing a proximal duodenojejunal anastomosis. This model can be useful for the study of glucose metabolism without malabsorption observed after the SADI-S technique. Methods: Goto-Kakizaki rats, a genetic model of non-obese and non-hypertensive type 2 diabetes mellitus, that develop hyperglycemia at an early age was used. Surgery consisted in a sleeve gastrectomy, duodenojejunal anastomosis and duodenal exclusion using three different techniques: duodenal transection (DT), duodenal ligation with hem-o-lock (DLH), and duodenal ligation with suture (DLS). Surgery time, weight loss, morbidity and mortality were recorded. Results: A total of 16 animals were subjected to surgical intervention and overall mortality was 25 %, with the DT group showing the highest mortality rate (42.9 %). No differences were observed among groups in terms of weight loss. Conclusion: The surgical technique described in this work is feasible and reproducible. Weight loss is comparable regardless of the technique used for duodenal exclusion.
RESUMO
Studies have shown that anodically grown TiO2 nanotubes (TNTs) exhibit excellent biocompatibility. However, TiO2 nanowires (TNWs) have received less attention. The objective of this study was to investigate the proliferation of osteoblast precursor cells on the surfaces of TNWs grown by electrochemical anodization of a Ti-35Nb-7Zr-5Ta (TNZT) alloy. TNT and flat TNZT surfaces were used as control samples. MC3T3-E1 cells were cultured on the surfaces of the samples for up to 5 days, and cell viability and proliferation were investigated using fluorescence microscopy, colorimetric assay, and scanning electron microscopy. The results showed lower cell proliferation rates on the TNW surface compared to control samples without significant differences in cell survival among experimental conditions. Contact angles measurements showed a good level of hydrophilicity for the TNWs, however, their relatively thin diameter and their high density may have affected cell proliferation. Although more research is necessary to understand all the parameters affecting biocompatibility, these TiO2 nanostructures may represent promising tools for the treatment of bone defects and regeneration of bone tissue, among other applications.
Assuntos
Nanotubos , Nanofios , Ligas/química , Proliferação de Células , Microscopia Eletrônica de Varredura , Nanotubos/química , Osteoblastos , Propriedades de Superfície , Titânio/química , Titânio/farmacologiaRESUMO
The search for novel therapies for the treatment of Alzheimer's disease is an urgent need, due to the current paucity of available pharmacological tools and the recent failures obtained in clinical trials. Among other strategies, the modulation of amyloid-triggered neuroinflammation by the endocannabinoid system seems of relevance. Previous data indicate that the enhancement of the endocannabinoid tone through the inhibition of the enzymes responsible for the degradation of their main endogenous ligands may render beneficial effects. Based on previously reported data, in which we described a paradoxical effect of the genetic deletion of the fatty acid amide hydrolase, we here aimed to expand our knowledge on the role of the endocannabinoid system in the context of Alzheimer's disease. To that end, we inhibited the production of interleukin-1ß, one of the main inflammatory cytokines involved in the neuroinflammation triggered by amyloid peptides, in a transgenic mouse model of this disease by using minocycline, a drug known to impair the synthesis of this cytokine. Our data suggest that interleukin-1ß may be instrumental in order to achieve the beneficial effects derived of fatty acid amide hydrolase genetic inactivation. This could be appreciated at the molecular (cytokine expression, amyloid production, plaque deposition) as well as behavioral levels (memory impairment). We here describe a previously unknown link between the endocannabinoid system and interleukin-1ß in the context of Alzheimer's disease that open new possibilities for the development of novel therapeutics.
Assuntos
Doença de Alzheimer/metabolismo , Amidoidrolases/genética , Interleucina-1beta/fisiologia , Doença de Alzheimer/genética , Animais , Citocinas/biossíntese , Citocinas/genética , Modelos Animais de Doenças , Mediadores da Inflamação/metabolismo , Interleucina-1beta/metabolismo , Camundongos Knockout , Camundongos Transgênicos , Microglia/citologia , Minociclina/farmacologia , FenótipoRESUMO
BACKGROUND: Because of their low levels of expression and the inadequacy of current research tools, CB2 cannabinoid receptors (CB2R) have been difficult to study, particularly in the brain. This receptor is especially relevant in the context of neuroinflammation, so novel tools are needed to unveil its pathophysiological role(s). METHODS: We have generated a transgenic mouse model in which the expression of enhanced green fluorescent protein (EGFP) is under the control of the cnr2 gene promoter through the insertion of an Internal Ribosomal Entry Site followed by the EGFP coding region immediately 3' of the cnr2 gene and crossed these mice with mice expressing five familial Alzheimer's disease (AD) mutations (5xFAD). RESULTS: Expression of EGFP in control mice was below the level of detection in all regions of the central nervous system (CNS) that we examined. CB2R-dependent-EGFP expression was detected in the CNS of 3-month-old AD mice in areas of intense inflammation and amyloid deposition; expression was coincident with the appearance of plaques in the cortex, hippocampus, brain stem, and thalamus. The expression of EGFP increased as a function of plaque formation and subsequent microgliosis and was restricted to microglial cells located in close proximity to neuritic plaques. AD mice with CB2R deletion exhibited decreased neuritic plaques with no changes in IL1ß expression. CONCLUSIONS: Using a novel reporter mouse line, we found no evidence for CB2R expression in the healthy CNS but clear up-regulation in the context of amyloid-triggered neuroinflammation. Data from CB2R null mice indicate that they play a complex role in the response to plaque formation.