Showing papers by "Javier Carrasco published in 2005"
TL;DR: It is shown for the first time that even though TgMT mice were more susceptible to KA, the cerebral MT‐I overexpression decreases the hippocampal inflammation and delayed neuronal degeneration and cell death as measured 3 days after KA administration, and indicates thatMT‐I therapy could be used against neurological disorders.
Abstract: We examined metallothionein (MT)-induced neuroprotection during kainic acid (KA)-induced excitotoxicity by studying transgenic mice with MT-I overexpression (TgMT mice). KA induces epileptic seizures and hippocampal excitotoxicity, followed by inflammation and delayed brain damage. We show for the first time that even though TgMT mice were more susceptible to KA, the cerebral MT-I overexpression decreases the hippocampal inflammation and delayed neuronal degeneration and cell death as measured 3 days after KA administration. Hence, the proinflammatory responses of microglia/macrophages and lymphocytes and their expression of interleukin (IL)-1, IL-6, IL-12, tumor necrosis factor-alpha and matrix metalloproteinases (MMP-3, MMP-9) were significantly reduced in hippocampi of TgMT mice relative to wild-type mice. Also by 3 days after KA, the TgMT mice showed significantly less delayed damage, such as oxidative stress (formation of nitrotyrosine, malondialdehyde, and 8-oxoguanine), neurodegeneration (neuronal accumulation of abnormal proteins), and apoptotic cell death (judged by TUNEL and activated caspase-3). This reduced bystander damage in TgMT mice could be due to antiinflammatory and antioxidant actions of MT-I but also to direct MT-I effects on the neurons, in that significant extracellular MT presence was detected. Furthermore, MT-I overexpression stimulated astroglia and increased immunostaining of antiinflammatory IL-10, growth factors, and neurotrophins (basic fibroblastic growth factor, transforming growth factor-beta, nerve growth factor, brain-derived neurotrophic factor, glial-derived neurotrophic factor) in hippocampus. Accordingly, MT-I has different functions that likely contribute to the increased neuron survival and improved CNS condition of TgMT mice. The data presented here add new insight into MT-induced neuroprotection and indicate that MT-I therapy could be used against neurological disorders.
125 citations
TL;DR: IL‐6 deficiency showed a dramatic effect in the expression of many genes, especially in the 1 day post‐lesion timing, which presumably underlies the poor capacity of IL‐6 knockout mice to cope with brain damage.
Abstract: Traumatic injury to the brain is one of the leading causes of injury-related death or disability. Brain response to injury is orchestrated by cytokines, such as interleukin (IL)-6, but the full repertoire of responses involved is not well known. We here report the results obtained with microarrays in wild-type and IL-6 knockout mice subjected to a cryolesion of the somatosensorial cortex and killed at 0, 1, 4, 8 and 16 days post-lesion. Overall gene expression was analyzed by using Affymetrix genechips/oligonucleotide arrays with approximately 12,400 probe sets corresponding to approximately 10,000 different murine genes (MG_U74Av2). A robust, conventional statistical method (two-way anova) was employed to select the genes significantly affected. An orderly pattern of gene responses was clearly detected, with genes being up- or down-regulated at specific timings consistent with the processes involved in the initial tissue injury and later regeneration of the parenchyma. IL-6 deficiency showed a dramatic effect in the expression of many genes, especially in the 1 day post-lesion timing, which presumably underlies the poor capacity of IL-6 knockout mice to cope with brain damage. The results highlight the importance of IL-6 controlling the response of the brain to injury as well as the suitability of microarrays for identifying specific targets worthy of further study.
55 citations
TL;DR: It appears that LFR caused more alterations in the HPA axis than DFR and, therefore, the latter FR schedule should be used in those protocols necessarily involving partial FR.
Abstract: Partial food restriction (FR) protocols have been used not only to study behavioral and physiological consequences of decrease food intake, but as a necessary treatment of the animals in some operant learning tasks. It is well-established in rodents that restricting food availability to a few hours in the morning causes an alteration of the daily rhythm of corticosterone, thus making it difficult to evaluate whether or not such treatments are stressful. In the present experiment adult male Sprague-Dawley rats were subjected to two different FR schedules: food availability after 1100 h (LFR) or after 1900 h (DFR). After 14 days, animals from both groups, together with corresponding controls, were killed under resting conditions, either in the morning or in the evening, just before daily access to food in FR rats. Both FR schedules reduced body weight gain to the same extent, but their impact on the hypothalamic-pituitary-adrenal (HPA) axis was different: DFR increased relative, but not absolute, adrenal weight and morning and evening levels of corticosterone, whereas LFR increased both absolute and relative adrenal weights and increased morning corticosterone levels to a greater extent than DFR rats. Neither serum ACTH nor corticotropin-releasing factor (CRF) mRNA levels in the paraventricular nucleus of the hypothalamus were altered by DFR or LFR protocols, suggesting that factors other than CRF and ACTH are involved in the control of adrenocortical secretion under FR. It appears that LFR caused more alterations in the HPA axis than DFR and, therefore, the latter FR schedule should be used in those protocols necessarily involving partial FR.
34 citations