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101.
Evidence that Glyceraldehyde-3-Phosphate Dehydrogenase Is Involved in Age-Induced Apoptosis in Mature Cerebellar Neurons in Culture 总被引:5,自引:0,他引:5
Ryoichi Ishitani Katsuyoshi Sunaga Atsushi Hirano †Paul Saunders Nobuo Katsube †De-Maw Chuang 《Journal of neurochemistry》1996,66(3):928-935
Abstract: Under typical culture conditions, cerebellar granule cells die abruptly after 17 days in vitro. This burst of neuronal death involves ultrastructural changes and internucleosomal DNA fragmentations characteristic of apoptosis and is effectively arrested by pretreatment with actinomycin-D and cycloheximide. The level of a 38-kDa protein in the particulate fraction is markedly increased during age-induced cell death and by pretreatment with NMDA, which potentiates this cell death. Conversely, the age-induced increment of the 38-kDa particulate protein is suppressed by actinomycin-D and cycloheximide. N-terminal microsequencing of the 38-kDa protein revealed sequence identity with glyceraldehyde-3-phosphate dehydrogenase (GAPDH). A GAPDH antisense oligodeoxyribonucleotide blocks age-induced expression of the particulate 38-kDa protein and effectively inhibits neuronal apoptosis. In contrast, the corresponding sense oligonucleotide of GAPDH was completely ineffective in preventing the age-induced neuronal death and the 38-kDa protein overexpression. Moreover, the age-induced expression of the 38-kDa protein is preceded by a pronounced increase in the GAPDH mRNA level, which is abolished by actinomycin-D, cycloheximide, or the GAPDH antisense, but not sense, oligonucleotide. Thus, our results suggest that overexpression of GAPDH in the particulate fraction has a direct role in age-induced apoptosis of cerebellar neurons. 相似文献
102.
Dahlia Minc-Golomb Gal Yadid Ilan Tsarfaty James H. Resau Joan P. Schwartz 《Journal of neurochemistry》1996,66(4):1504-1509
Abstract: In the CNS, nitric oxide (NO) functions as both neuromodulator and neurotoxic agent. In vivo neuronal expression of NO synthase (NOS) has been attributed to constitutive NOS—both the neuronal and the endothelial types. The other class of NOS—the inducible NOS (iNOS)—is known to mediate toxic effects of NO in various tissues. In this study, we show for the first time that direct intracerebellar injection of endotoxin and cytokine (lipopolysaccharide and interferon-γ) induced in vivo neuronal expression of the iNOS gene, as demonstrated by fluorescent in situ hybridization and immunohistochemical staining analyzed by confocal laser-scanning microscopy. This raises the possibility that neuronal iNOS might contribute significantly to the vulnerability of the brain to various insults. 相似文献
103.
Johannes H. P. Hackstein Theo A. van Alen 《Evolution; international journal of organic evolution》1996,50(2):559-572
It has been assumed that the feeding habits of vertebrates predispose the variety of intestinal differentiations and the composition of the microbial biota living in their intestinal tracts. Consequently, the presence of methanogenic bacteria in the various differentiations of the large intestine and the foregut of herbivorous vertebrates had been attributed primarily to the existence of anaerobic habitats and the availability of carbon dioxide and hydrogen originating from the fermentative microbial digestion of plant-based diets. However, Australian ratites, many murids, and several New World primates lack methanogens, despite their intestinal differentiations and their vegetarian feeding habits. Crocodiles, giant snakes, aardvarks, and ant-eaters on the other hand release significant amounts of methane. A determination of methane emissions by 253 vertebrate species confirmed that competence for intestinal methanogenic bacteria is shared by related species and higher taxa, irrespective of different feeding habits. In “methanogenic” branches of the evolutionary tree, a variety of differentiations of the large intestine evolved and, in some cases, differentiations of the foregut. In contrast, the lack of competence for methanogens in chiropterans/insectivores and carnivores apparently has precluded the evolution of specialized fermenting differentiations of the digestive tract. Our observations reveal that the presence of intestinal methanogenic bacteria is under phylogenetic rather than dietary control: competence for intestinal methanogenic bacteria is a plesiomorphic (primitive-shared) character among reptiles, birds, and mammals. This competence for methanogenic bacteria has been crucial for the evolution of the amniotes. 相似文献
104.
105.
Ras-Regulated Hypophosphorylation of the Retinoblastoma Protein Mediates Neuronal Differentiation in PC12 Cells 总被引:2,自引:0,他引:2
†HongZhen Li ‡Hiroshi Kawasaki ‡Eisuke Nishida Seisuke Hattori Shun Nakamura 《Journal of neurochemistry》1996,66(6):2287-2294
Abstract: To investigate the role of the retinoblastoma protein pRB in neuronal differentiation, we have measured the accumulation of hypophosphorylated pRB in PC12 cells stimulated by nerve growth factor (NGF). NGF induced the accumulation of hypophosphorylated pRB within 30 min and the level peaked after 12 h. Viral Kiras, cyclic AMP (cAMP), and 12- O -tetradecanoylphorbol 13-acetate (TPA) also induced the hypophosphorylation of pRB, but epidermal growth factor and interleukin-6 did not. The extent of hypophosphorylation of pRB correlated well with the capacity of these factors to stimulate neurite outgrowth. The constitutively activated Ras induced persistent shift of the phosphorylation state of pRB toward hypophosphorylation. A dominant negative form of cHa-Ras suppressed significantly induction of the hypophosphorylation of pRB by NGF, but not by cAMP. Taken together, these results suggest that the hypophosphorylation of pRB triggered by NGF is mediated by a Ras-dependent pathway. Furthermore, microinjection of a monoclonal antibody specific for the hypophosphorylated form of pRB blocked the neurite outgrowth initiated by NGF. These results suggest a crucial role of pRB in withdrawal of cells from the cell cycle and in neuronal differentiation of PC12 cells. 相似文献
106.
Molecular genetics of cellular differentiation in leaves 总被引:2,自引:1,他引:1
107.
Isozyme analysis of Galaxias species (Teleostei: Galaxiidae) from the Taieri River, South Island, New Zealand: a species complex revealed 总被引:2,自引:0,他引:2
Richard M. Allibone Todd A. Crowl Jean M. Holmes Tania M. King Robert M. McDowall Colin R. Townsend Graham P. Wallis 《Biological journal of the Linnean Society. Linnean Society of London》1996,57(2):107-127
We examined genetic differentiation among 23 samples of non-migratory river galaxias from 17 streams in the Taieri River system, South Island, New Zealand. Four major genetic types were found, two of which occur in narrow sympatry in one location. These were compared with topotypical material representing Galaxias anomalus from the Clutha system (Otago) and G. vulgaris from the Waimakariri system (Canterbury) in order to establish identity. Morphological examination of these four major genetic types revealed consistent concomitant differences. The results suggest that there are at least three species of river galaxias in the Taieri system: G. anomalus, G. vulgaris and at least one previously undescribed species. We propose that the genetic structuring and subsequent speciation of this group has been promoted by the absence of the marine juvenile phase that is found in five other members of the genus native to New Zealand. This structuring may be exacerbated by population fragmentation over the last century owing to the negative influence of introduced trout. The phylogenetic diversity within the river system mirrors the diverse flora and invertebrate fauna of the region, and has conservation implications that parallel those resulting from our improved knowledge of the New Zealand herpetofauna through the application of genetic analysis. 相似文献
108.
Consequences of food-attraction conditioning in Helix: a behavioral and electrophysiological study 总被引:1,自引:0,他引:1
M. Peschel V. Straub T. Teyke 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1996,178(3):317-327
Food-attraction conditioning is a learning phenomenon by which adult Helix pomatia acquire the ability to locate food through exposure to that particular food. Food-conditioned snails can be distinguished from naive snails during their approach to food. Naive snails keep their tentacles upright — whereas food-conditioned animals bend the tentacles down-ward, in a horizontal orientation, pointed in the direction of the food.Tentacle musculature is innervated by two peritentacular nerves (PTn), each projecting to approximately one hemi-section of the tentacle wall. Stimulating the peritentacular nerves caused the tentacles to bend downward in a manner reflecting the full complement of tentacle movements performed by conditioned snails.The neural correlate of tentacle movements was investigated in isolated ganglion preparations with the posterior tentacles attached. PT nerve activity was recorded while the olfactory epithelia were stimulated with natural food odors. Preparations obtained from conditioned animals responded with a substantial increase in unit activity (mean increase 280%) to stimulation with odor of the conditioned food but not to other odors. Preparations from naive animals did not respond to food odor stimulation. The electrophysiological results demonstrated that plasticity due to conditioning the snails in vivo survived dissection and could be monitored in vitro.Abbreviations
ext PTn
external peritentacular nerve
-
int PTn
internal peritentacular nerve 相似文献
109.
110.
懒猴属的核糖体DNA变异及其种间分化关系 总被引:5,自引:2,他引:3
用15种限制性内切酶和人28S、18SrDNA探针构建了懒猴属各物种核糖体DNA重复单位的限制性内切酶图谱。在进化速率较高的非转录间隔区,在大、中、小懒猴中分别定位了23、24、24个酶切位点。大懒猴与中懒猴有12个位点不同,与小懒猴有14个位点不同,而中、小懒猴间则只有一个位点的差异。经过计算,大懒猴与中懒猴的遗传距离值为12.65%,与小懒猴的差异为14.24%,中、小懒猴间的差异则仅为0.7 相似文献