ABSTRACT
Frontotemporal dementia (FTD) is a neurodegenerative disorder characterized by progressive impairment in behavior, executive function, and language. The behavioral variant (bvFTD) is the most clinical common form and requires differential diagnosis with atypical Alzheimer's disease (AD) cases. This study aimed to investigate the plasma metabolite profile of patients with bvFTD compared to AD patients and cognitively healthy individuals using gas chromatography coupled to mass spectrometry (GCMS). This study included nine patients with bvFTD, 17 with AD and 15 cognitively healthy controls (training set), whose data were validated on a testing set (eight bvFTD, 14 AD and ten controls). The metabolites were detected by GCMS. A tendency towards a reduction in the levels of palmitoleic, oleic and lauric acids was found in the bvFTD group compared to the AD group; however, no significance after multiple comparison correction was observed. However, bvFTD group showed reduced levels of creatinine, glycine, tryptophan, uric acid, hypoxanthine, serine, valine, threonine, isoleucine, homoserine, methionine, glutamic acid, capric acid, tartronic acid, fumaric acid, and myo-inositol, metabolites related to glycine/serine/threonine, alanine/aspartate/glutamate pathways and aminoacyl-tRNA biosynthesis, when compared to controls. The data suggest that bvFTD patients may present an impairment of amino acid metabolism and the translation process. This pioneering study on bvFTD and its plasma metabolomic signature can be useful to provide new ideas about pathophysiological mechanisms, as well as guide more robust studies in search of possible biomarkers for the diagnosis of this important dementia.
Subject(s)
Alzheimer Disease , Frontotemporal Dementia , Diagnosis, Differential , Frontotemporal Dementia/diagnosis , Gas Chromatography-Mass Spectrometry , Humans , Neuropsychological TestsABSTRACT
Fundamento: a Doença de Alzheimer (DA) é o tipo mais comum de demência, sendo histologicamente caracterizada pela deposição de peptídeo ß-amiloide, hiperfosforilação da proteína tau, neuroinflamação e perda neuronal, favorecida por diferentes mecanismos fisiopatológicos. O diabetes mellitus tipo 2 (DM2) ocorre devido à resistência periférica à insulina e à insuficiência insulínica (em fases mais avançadas da doença). Dados epidemiológicos sugerem relação entre DA e DM2, embora os supostos mecanismos fisiopatológicos comuns dessa inter-relação sejam obscuros. Objetivos: revisar os principais mecanismos fisiopatológicos compartilhados pela DA e DM2. Métodos: foram pesquisados artigos de 2000 a 2017 nas bases de dados do Portal CAPES/MEC, utilizando as palavras-chave: doença de Alzheimer, diabetes mellitus tipo 2, lesão vascular, resistência à insulina e estresse oxidativo. Resultados: 127 publicações foram analisadas e 73 incluídas. Lesão endotelial, resistência à insulina e estresse oxidativo foram os aspectos fisiopatológicos mais importantes e comuns à DA e DM2. Conclusão: há indícios de relação entre DA e DM2, embora não esteja clara se a relação é causal. Consequentemente, há a necessidade de estudos mais aprofundados sobre marcadores e mecanismos relacionados, visando o desenvolvimento de programas de prevenção e intervenção nas duas doenças em conjunto. (AU)
Introduction: Alzheimer's Disease (AD) is the most common type of dementia and is histologically characterized by deposition of ß-amyloid peptide, hyperphosphorylation of tau protein, neuronal loss and neuroinflammation, favored by different pathophysiological mechanisms. The type 2 diabetes mellitus (T2DM) occurs due to peripheral insulin resistance and insulin insufficiency (in later stages of the disease). Epidemiological data suggest a relationship between AD and T2DM, although the supposed common pathophysiological mechanisms of this interrelation are obscure. Objectives: to review the main pathophysiological mechanisms possibly shared by AD and T2DM. Methods: articles were searched from 2000 to 2017 in the databases of Portal CAPES / MEC, using the key words: Alzheimer's disease, type 2 diabetes mellitus, vascular injury, insulin resistance and oxidative stress. Results: we selected 73 from 127 articles. Endothelial injury, insulin resistance and oxidative stress are pathophysiological aspects common to AD and T2DM. Conclusion: there is evidence of a relationship between AD and T2DM, although it is unclear whether the relation is causal. There is a need for more studies about markers and related mechanisms, aiming at the development of prevention and intervention programs in both diseases. (AU)
