RESUMO
Neuroglobin (Ngb) is expressed in the central and peripheral nervous system, cerebrospinal fluid, retina, and endocrine tissues where it is involved in binding O2 and other gasotransmitters. Several studies have highlighted its endogenous neuroprotective function. Huntington's disease (HD), a dominant hereditary disease, is characterized by the gradual loss of neurons in discrete areas of the central nervous system. We analyzed the expression of Ngb in the brain tissue of a mouse model of HD, in order to define the role of Ngb with respect to individual cell type vulnerability in HD and to gender and age of mice. Our results showed different expressions of Ngb among neurons of a specific region and between different brain regions. We evidenced a decreased intensity of Ngb at 13 weeks of age, compared to 7 weeks of age. The double immunofluorescence and fluorescence resonance energy transfer (FRET) experiments showed that the co-localization between Ngb and huntingtin at the subcellular level was not close enough to account for a direct interaction. We also observed a different expression of Ngb in the striatum, depending on the sex and age of animals. These findings provide the first experimental evidence for an adaptive response of Ngb in HD, suggesting that Ngb may exert neuroprotective effects in HD beyond its role in reducing sensitivity to oxidative stress.
Assuntos
Corpo Estriado/metabolismo , Regulação da Expressão Gênica/genética , Globinas/metabolismo , Doença de Huntington/patologia , Proteínas do Tecido Nervoso/metabolismo , Fatores de Ribosilação do ADP , Animais , Toxinas Bacterianas , Linhagem Celular Tumoral , Colinesterases/metabolismo , Corpo Estriado/patologia , Modelos Animais de Doenças , Feminino , Transferência Ressonante de Energia de Fluorescência , Proteína Huntingtina/genética , Doença de Huntington/genética , Masculino , Camundongos , Camundongos Transgênicos , Mutação/genética , Neuroglobina , Neurônios/metabolismo , Parvalbuminas/metabolismo , Fatores Sexuais , Fatores de TempoRESUMO
A new tetraphosphine, the cis-cis-cis-1,2,3,4-tetrakis(diphenylphosphinomethyl)cyclopentane (Tedicyp) 1 has been synthesized, characterized, and used in Pd-catalyzed allylic substitutions. The Tedicyp was easily prepared in seven steps from the commercially available himic anhydride. The structure of the complex Tedicyp-borane was determined by X-ray analysis. The tetraphosphine in combination with [Pd(eta(3)-C(3)H(5))Cl](2) affords a very efficient catalyst for allylic substitution of several allylic acetates. Under mild conditions, very high turnover numbers and turnover frequencies have been obtained.
RESUMO
The intramolecular [2 + 2] photocycloaddition of bismaleimides leads to cage diimides 2. Nucleophilic addition on these compounds (NaBH4, RLi, or MeONa) gives rise to various diazatetracyclic 4 and 11 or oxadiazapentacyclic 3 "bowl shaped" alcohols. X-ray analyses of 3c and 11a provide definite structural data concerning these two highly functionalized compounds.