RESUMO
Frontotemporal dementia (FTD) is a neurodegenerative disease which affects mainly the frontal and anterior temporal cortex. It is associated with neuronal loss, gliosis, and microvacuolation of lamina I to III in these brain regions. In previous studies we have described neurons with DNA damage in the absence of tangle formation and suggested this may result in tangle-independent mechanisms of neurodegeneration in the AD brain. In the present study, we sought to examine DNA fragmentation and activated caspase-3 expression in FTD brain where tangle formation is largely absent. The results demonstrate that numerous nuclei were TdT positive in all FTD brains examined. Activated caspase-3 immunoreactivity was detected in both neurons and astrocytes and was elevated in FTD cases as compared to control cases. A subset of activated caspase-3-positive cells were also TdT positive. In addition, the cell bodies of a subset of astrocytes showed enlarged, irregular shapes, and vacuolation and their processes appeared fragmented. These degenerating astrocytes were positive for activated caspase-3 and colocalized with robust TdT-labeled nuclei. These findings suggest that a subset of astrocytes exhibit degeneration and that DNA damage and activated caspase-3 may contribute to neuronal cell death and astrocyte degeneration in the FTD brain. Our results suggest that apoptosis may be a mechanism of neuronal cell death in FTD as well as in AD (228).
Assuntos
Astrócitos/enzimologia , Caspases/metabolismo , Dano ao DNA , Demência/patologia , Demência/fisiopatologia , Neurônios/enzimologia , Idoso , Idoso de 80 Anos ou mais , Apoptose , Astrócitos/patologia , Sintomas Comportamentais/diagnóstico , Encéfalo/enzimologia , Encéfalo/patologia , Caspase 3 , Núcleo Celular/enzimologia , Núcleo Celular/patologia , Fragmentação do DNA , Demência/diagnóstico , Evolução Fatal , Feminino , Lobo Frontal/enzimologia , Lobo Frontal/patologia , Proteína Glial Fibrilar Ácida/metabolismo , Gliose , Humanos , Masculino , Pessoa de Meia-Idade , Neuritos/enzimologia , Neuritos/patologia , Neurônios/patologia , Células Piramidais/enzimologia , Células Piramidais/patologia , Lobo Temporal/enzimologia , Lobo Temporal/patologiaRESUMO
The galls of the agamic generation of the cynipid gall-wasp Cynips divisa were studied; these galls are found only on the main veins of the leaf. Galls are concentrated on the middle veins of leaves, and generally occur closer to the midrib than to the edge of the leaf. Survival of the gall-maker and fecundity of the energing wasp depend on wasp size and position of the gall. There is a striking pattern in gall size according to the number of galls on the vein. The number of galls on a vein appears therefore to have a strong effect on potential fecundity.
