Gangliosides are considered to be essential in the maintenance and repair of nervous tissues; however, the mechanisms for neurodegeneration caused by ganglioside defects are unknown. We examined gene expression profiles in double knockout (DKO) mice of GM2/GD2 synthase and GD3 synthase genes and showed that the majority of complement genes and their receptors were up-regulated in cerebellum in DKO mice. Inflammatory reactions were demonstrated in those tissues by measuring up-regulated inflammatory cytokines, indicating the presence of complement activation and inflammation as reported in Alzheimer's disease. Immunoblotting of fractionated membrane extracts by sucrose density gradient revealed that complement-regulatory molecules such as decay-accelerating factor and CD59 were dispersed from glycolipid-enriched microdomain/rafts in DKO cerebellum. Immunohistostaining of these molecules showed disordered membrane localization. These results suggested that dysfunction of complement-regulatory molecules may be due to abnormal glycolipid-enriched microdomain/rafts that triggered complement activation, subsequent inflammation, and neurodegeneration in DKO mice. Generation of the triple KO mice lacking complement activity in addition to the two glycosyltransferases suggested that complement activation is involved in the inflammatory reactions and neurodegeneration caused by the ganglioside deficiency.cerebellum ͉ degeneration ͉ inflammation ͉ knockout ͉ lipid raft
Mast cells (MCs) are widely distributed in most human tissues. Those cells that contain only tryptase are designated as T-MCs, while those that also contain chymase are referred to as TC-MCs. This study uses immunohistochemical staining for tryptase and chymase to assess the distribution and heterogeneity of these two types of MCs in the human uterus. The greatest number of MCs was found in the inner (i.e. luminal) half of the myometrium, with this area containing approximately equal proportions of T-MCs and TC-MCs. There were fewer MCs in the outer half of the myometrium and the cervix, but the proportion of TC-MCs in both of these areas was substantially higher. In contrast, the endometrium contained significantly fewer MCs, but proportionally more T-MCs. There was no change in the number of MCs between the proliferative and secretory phases of the menstrual cycle; however, there was a significantly lower number in all areas after menopause. Most of the MCs were observed in close association with uterine smooth muscle cells, as well as in the vicinity of fibroblasts and collagen, and it appears they may play an important role in the reconstruction of uterine tissues during the menstrual cycle.
To examine a possible protective effect of exogenous glial cell line-derived neurotrophic factor (GDNF) gene expression against ischemic brain injury, a replication-defective adenoviral vector containing GDNF gene (Ad-GDNF) was directly injected into the cerebral cortex at 1 day before 90 minutes of transient middle cerebral artery occlusion (MCAO) in rats. 2,3,5-Triphenyltetrazolium chloride staining showed that infarct volume of the Ad-GDNF-injected group at 24 hours after the transient MCAO was significantly smaller than that of vehicle- or Ad-LacZ-treated group. Enzyme-linked immunosorbent assay (ELISA) for immunoreactive GDNF demonstrated that GDNF gene products in the Ad-GDNF-injected group were higher than those of vehicle-treated group at 24 hours after transient MCAO. Immunoreactive GDNF staining was obviously detected in the cortex around the needle track just before or 24 hours after MCAO in the Ad-GDNF group, whereas no or slight GDNF staining was detected in the vehicle group. The numbers of TUNEL, immunoreactive caspase-3, and cytochrome c-positive neurons induced in the ipsilateral cerebral cortex at 24 hours after transient MCAO were markedly reduced by the Ad-GDNF group. These results suggest that the successful exogenous GDNF gene transfer ameliorates ischemic brain injury after transient MCAO in association with the reduction of apoptotic signals.
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