脊髓全横断损伤后差异表达蛋白的蛋白质组学分析

 对脊髓全横断损伤前后的大鼠脊髓全蛋白质进行双向凝胶电泳,借助PDQuest软件从中找出差异表达蛋白质点.应用基质辅助激光解吸电离串联质谱,对差异表达的蛋白质点进行鉴定,成功鉴定出18种蛋白质.脊髓损伤3 d后表达上调的蛋白质有巨噬细胞游走抑制因子、S期激酶相关蛋白 1、热休克蛋白 27、多配体蛋白聚糖 3、T细胞受体β链可变区、膜联蛋白Ⅲ、腺苷酸激酶 1、半乳凝素 3、丙酮酸脱氢酶、磷脂酶 B、嗜铬粒蛋白 A、热休克蛋白70凝结蛋白 1;同时表达下调的蛋白质有磷酸丙糖异构酶、神经鞘氨醇磷酸化受体、热休克蛋白10、肽酰 脯氨酰 顺反式异构酶 A多数差异蛋白质涉及到神经细胞的增殖、凋亡、应激反应等过程,为进一步阐明中枢神经系统的损伤和修复机制提供了理论依据.摘要 对脊髓全横断损伤前后的大鼠脊髓全蛋白质进行双向凝胶电泳,借助PDQuest软件从中找出差异表达蛋白质点.应用基质辅助激光解吸电离串联质谱,对差异表达的蛋白质点进行鉴定,成功鉴定出18种蛋白质.脊髓损伤3 d后表达上调的蛋白质有巨噬细胞游走抑制因子、S期激酶相关蛋白 1、热休克蛋白 27、多配体蛋白聚糖 3、T细胞受体β链可变区、膜联蛋白Ⅲ、腺苷酸激酶 1、半乳凝素 3、丙酮酸脱氢酶、磷脂酶 B、嗜铬粒蛋白 A、热休克蛋白70凝结蛋白 1;同时表达下调的蛋白质有磷酸丙糖异构酶、神经鞘氨醇磷酸化受体、热休克蛋白10、肽酰 脯氨酰 顺反式异构酶 A多数差异蛋白质涉及到神经细胞的增殖、凋亡、应激反应等过程,为进一步阐明中枢神经系统的损伤和修复机制提供了理论依据.     

基于相互作用的蛋白质功能预测

蛋白质功能预测是后基因时代研究的热点问题。基于相互作用的蛋白质功能预测方法目前应用比较广泛,但是当"伙伴蛋白质"(interacting partners)数目k较小时,其预测准确率不高。从蛋白质相互作用网络入手,结合"小世界网络"特性,有效解决了k较小时预测准确率不高的问题。对酵母(Saccharomyces cerevisiae)蛋白质的相互作用网络进行预测,当k≤4时其预测准确率比相同条件下的GO(global optimization)方法有一定提高。实验结果表明:该方法能够有效的应用于伙伴蛋白质数目较小时的蛋白质功能预测。     

Quercetin, a flavonoid antioxidant, modulates endothelium-derived nitric oxide bioavailability in diabetic rat aortas

The present work examined the effect of chronic oral administration of quercetin, a flavonoid antioxidant, on blood glucose, vascular function and oxidative stress in STZ-induced diabetic rats. Male Wistar-Kyoto (WKY) rats were randomized into euglycemic, untreated diabetic, vehicle (1% w/v methylcellulose)-treated diabetic, which served as control, or quercetin (10mgkg(-1) body weight)-treated diabetic groups and treated orally for 6 weeks. Quercetin treatment reduced blood glucose level in diabetic rats. Impaired relaxations to endothelium-dependent vasodilator acetylcholine (ACh) and enhanced vasoconstriction responses to alpha(1)-adrenoceptor agonist phenylephrine (PE) in diabetic rat aortic rings were restored to euglycemic levels by quercetin treatment. Pretreatment with N(omega)-nitro-l-arginine methyl ester (l-NAME, 10microM) or methylene blue (10microM) completely blocked but indomethacin (10microM) did not affect relaxations to ACh in aortic rings from vehicle- or quercetin-treated diabetic rats. PE-induced vasoconstriction with an essentially similar magnitude in vehicle- or quercetin-treated diabetic rat aortic rings pretreated with l-NAME (10microM) plus indomethacin (10microM). Quercetin treatment reduced plasma malonaldehyde (MDA) plus 4-hydroxyalkenals (4-HNE) content as well as increased superoxide dismutase activity and total antioxidant capacity in diabetic rats. From the present study, it can be concluded that quercetin administration to diabetic rats restores vascular function, probably through enhancement in the bioavailability of endothelium-derived nitric oxide coupled to reduced blood glucose level and oxidative stress.     

Review of spino-occipital and spinal nerves in Tetraodontiformes,with special reference to pectoral and pelvic fin muscle innervation

The spino-occipital nerve (SO) and ventral rami of the spinal nerves (SV) in 10 tetraodontiform families and 5 outgroup taxa were examined, with special reference to pectoral and pelvic fin muscle innervation. Compared with the outgroup taxa, tetraodontiforms were characteristic in having SO3 + SV1 (SO3 in tetraodontids) that gave off several lateral subbranches to the pectoral fin base and SO participation in infracarinalis anterior innervation. SO and SV1 were connected with one another (6 patterns) before entering the pectoral fin muscles in most species, including the outgroup taxa, resulting in the participation of SV1 in the innervation of almost all of the pectoral fin muscles. SO3 + SV1 was present in all tetraodontiforms (except in 2 tetraodontids having only SO3) and the outgroup taxa, an upper dorsal branch uniformly extending dorsally into the pectoral fin base. The pectoral fin base also received a branch ventrally, but its identity differed (participation or nonparticipation of SV2). SV1 alone constituting the branch was a derived condition occurring in Aracanidae, Ostraciidae, Tetraodontidae, Diodontidae, and Molidae. No strong characters supporting a tetraodontiform sister group were recognized among the spino-occipital nerve and ventral rami of spinal nerves.     

Mesenchymal Stem Cells from Rat Bone Marrow Downregulate Caspase-3-mediated Apoptotic Pathway After Spinal Cord Injury in Rats

Mesenchymal stem cells have been intensively studied for their potential use in reparative strategies for neurodegenerative diseases and traumatic injuries. We used mesenchymal stem cells (rMSC) from rat bone marrow to evaluate the therapeutic potential after spinal cord injury (SCI). Immunohistochemistry confirmed a large number of apoptotic neurons and oligodendrocytes in caudal segments 2 mm away from the lesion site. Expression of caspase-3 on both neurons and oligodendrocytes after SCI was significantly downregulated by rMSC. Caspase-3 downregulation by rMSC involves increased expression of FLIP and XIAP in the cytosol and inhibition of PARP cleavage in the nucleus. Animals treated with rMSC had higher Basso, Beattie, Bresnahan (BBB) locomotor scoring and better recovery of hind limb sensitivity. Treatment with rMSC had a positive effect on behavioral outcome and histopathological assessment after SCI. The ability of rMSC to incorporate into the spinal cord, differentiate and to improve locomotor recovery hold promise for a potential cure after SCI. Special issue in honor of Naren Banik.     

Shifts in the psychophysical function in rats

The primary goal was to compare results from a free-operant procedure with pigeons [Machado, A., Guilhardi, P., 2000. Shifts in the psychometric function and their implications for models of timing. J. Exp. Anal. Behav. 74, 25-54, Experiment 2] with new results obtained with rats. The secondary goal was to compare the results of both experiments with dependent variables that were not used in the original publication. As in the original study with pigeons, rats were trained on a two-alternative free-operant psychophysical procedure in which left lever press responses were reinforced during the first and second quarters of a 60-s trial, and right lever press responses were reinforced during the third and fourth quarters of the trial. The quarters were reinforced according to four independent variable interval (VI) schedules of reinforcement. The VI duration was manipulated in each quarter, and shifts in the psychophysical functions that relate response rate with time since trial onset were measured. The results obtained with rats were consistent with those previously obtained with pigeons. In addition, results not originally reported were also consistent between rats and pigeons, and provided insights into the perception, memory, and decision processes in Scalar Expectancy Theory and Learning-to-Time Theory.     

ERK 1/2 signaling pathway is involved in nicotine-mediated neuroprotection in spinal cord neurons

Evidence indicates that agonists of neuronal nicotinic receptors (nAChRs), including nicotine, can induce neuroprotective and anti-apoptotic effects in the CNS. To study these mechanisms, the present study focused on nicotine-mediated modulation of the extracellular regulated kinase 1 and 2 (ERK1/2) pathway in cultured spinal cord neurons. Exposure to nicotine (0.1-10 microM) for as short as 1 min markedly upregulated levels of phosphorylated ERK1/2 (pERK1/2) and increased total ERK1/2 activity. Inhibition studies with mecamylamine and alpha-bungarotoxin revealed that these effects were mediated by the alpha7 nicotinic receptor. In addition, pre-exposure to U0126, a specific inhibitor of the ERK1/2 signaling, prevented nicotine-mediated anti-apoptotic effects. To indicate if treatment with nicotine also can activate ERK1/2 in vivo, a moderate spinal cord injury (SCI) was induced in rats using a weight-drop device and nicotine was injected 2 h post-trauma. Consistent with in vitro data, nicotine increased levels of pERK1/2 in this animal model of spinal cord trauma. Results of the present study indicate that the ERK1/2 pathway is involved in anti-apoptotic effects of nicotine in spinal cord neurons and may be involved in therapeutic effects of nicotine in spinal cord trauma.     

Neuromodulation by Glutamate and Acetylcholine can Change Circuit Dynamics by Regulating the Relative Influence of Afferent Input and Excitatory Feedback

Substances such as acetylcholine and glutamate act as both neurotransmitters and neuromodulators. As neuromodulators, they change neural information processing by regulating synaptic transmitter release, altering baseline membrane potential and spiking activity, and modifying long-term synaptic plasticity. Slice physiology research has demonstrated that many neuromodulators differentially modulate afferent, incoming information compared to intrinsic and recurrent processing in cortical structures such as piriform cortex, neocortex, and the hippocampus. The enhancement of afferent (external) pathways versus the suppression at recurrent (internal) pathways could cause cortical dynamics to switch between a predominant influence of external stimulation to a predominant influence of internal recall. Modulation of afferent versus intrinsic processing could contribute to the role of neuromodulators in regulating attention, learning, and memory effects in behavior.     

Pathways involved in alanyl-glutamine-induced changes in neutrophil amino- and α-keto acid homeostasis or immunocompetence

Summary. We examined the effects of DON [glutamine-analogue and inhibitor of glutamine-requiring enzymes], alanyl-glutamine (regarding its role in neutrophil immunonutrition) and alanyl-glutamine combined with L-NAME, SNAP, DON, β-alanine and DFMO on neutrophil amino and α-keto acid concentrations or important neutrophil immune functions in order to establish whether an inhibitor of •NO-synthase [L-NAME], an •NO donor [SNAP], an analogue of taurine and a taurine transport antagonist [β-alanine], an inhibitor of ornithine-decarboxylase [DFMO] as well as DON could influence any of the alanyl-glutamine-induced effects. In summary, irrespective of which pharmacological, metabolism-inhibiting or receptor-mediated mechanisms were involved, our results showed that impairment of granulocytic glutamine uptake, modulation of intracellular glutamine metabolisation and/or de novo synthesis as well as a blockade of important glutamine-dependent metabolic processes may led to significant modifications of physiological and immunological functions of the affected cells.     

Development of distylous flowers and investment of biomass in male and female function in Palicourea padifolia (Rubiaceae)

Knowledge of developmental pathways for achieving differences in style and anther heights, in concert with those of ancillary features accompanied with data in regard to biomass investment to male and female function, provide an excellent opportunity for examining the developmental correlations between primary and ancillary floral traits so as to understand the evolution of heterostyly. The ontogenetic relationships between bud length and anther height and between bud length and style height, and between bud length versus bud width, anther length, and number of pollen grains per anther for long-styled (LS) and short-styled (SS) morphs of P. PADIFOLIA are described. We also described the ontogenetic biomass allocation to male and female function and to corolla with elongation of buds harvested at regular intervals. We observed an early termination of stylar growth in SS buds, whereas LS styles steadily increased in size. Morph differences for relative growth rates were significant for anther height, anther length, and pollen number but not for bud width. Bud width and anther length had a negative allometric relationship with bud elongation. The relationship between bud length and number of pollen grains per anther was positive and morph differences in pollen number were detected at later stages of development. An increase in corolla mass involved a disproportionate allocation to the female function in SS flowers and male allocation was similar for the two morphs over the course of development. Our results are consistent with theoretical and empirical data for distylous species with an approach herkogamous ancestor, and with the more general hypothesis of ontogenetic lability of heterostyly, in which morph differences in style and anther heights are achieved in various ways. Variations observed in sexual investment between floral morphs suggest differences in sex expression during flower development.