MORT1/FADD is involved in liver regeneration

AIM: To explore the role of the adaptor molecule in liver regeneration after partial hepatectomy (PH).METHODS: We used transgenic mice expressing an N-terminal truncated form of MORT1/FADD under the control of the albumin promoter. As previously shown,this transgenic protein abrogated CD95- and CD120a-mediated apoptosis in the liver. Cyclin A expression was detected using Western blotting. ELISA and RT-PCR were used to detect IL-6 and IL-6 mRNA, respectively. DNA synthesis in liver tissue was measured by BrdU staining.RESULTS: Resection of 70% of the liver was followed by a reduced early regenerative response in the transgenic group at 36 h. Accordingly, 36 h after hepatectomy, cyclin A expression was only detectable in wild-type animals. Consequently, the onset of liver mass restoration was retarded as measured by MRI volumetry and mortality was significantly higher in the transgenic group.CONCLUSION: Our data demonstrate for the first time an involvement of the death receptor molecule MORT1/FADD in liver regeneration, beyond its well described role as part of the intracellular death signaling pathway.     

Synergistic effects of AKAP95, Cyclin D1, Cyclin E1, and Cx43 in the development of rectal cancer

Objective: To explore the expression of A-kinase anchor protein 95 (AKAP95), Cyclin D1, Cyclin E1, and Connexin43 (Cx43) in rectal cancer tissues and assess the associations between each of the proteins and pathological parameters, as well as their inter-relationships. Methods: AKAP95, Cyclin D1, Cyclin E1, and Cx43 protein expression rates were evaluated by immunohistochemistry in 50 rectal cancer specimens and 16 pericarcinoma tissues. Results: The positive rates of AKAP95, Cyclin E1, and Cyclin D1 proteins were 54.00 vs. 18.75%, 62.00 vs. 6.25%, and 72.00 vs. 31.25% in rectal cancer specimens and pericarcinoma tissues, respectively, representing statistically significant differences (P < 0.05). The positive rate of Cx43 protein expression in rectal cancer tissues was 44.00% and 62.50% in pericarcinoma tissues, and the difference between them was not significant (P > 0.05). No significant associations were found between protein expression of AKAP95, Cyclin E1, Cyclin D1, and Cx43, and the degree of differentiation, histological type, and lymph node metastasis of rectal cancer (P > 0.05). However, significant correlations were obtained between the expression rates of AKAP95 and Cyclin E1, Cyclin E1 and Cyclin D1, Cyclin E1 and Cx43 protein, and Cyclin D1 and Cx43, respectively (P < 0.05). Conclusion: AKAP95, Cyclin E1, and Cyclin D1 protein expression rates were significantly higher in rectal cancer tissues compared with pericarcinoma samples, suggesting an association between these proteins and the development and progression of rectal cancer. In addition, the significant correlations between the proteins (AKAP95 and Cyclin E1, Cyclin E1 and Cyclin D1, Cyclin E1 and Cx43 protein, and Cyclin D1 and Cx43) indicate the possible synergistic effects of these factors in the development and progression of rectal cancer.     

CYLD deletion triggers nuclear factor-κB-signaling and increases cell death resistance in murine hepatocytes

AIM:To analyze the role of CYLD for receptor-mediated cell death of murine hepatocytes in acute liver injury models.METHODS:Hepatocyte cell death in CYLD knockout mice(CYLD-/-)was analyzed by application of liver injury models for CD95-(Jo2)and tumor necrosis factor(TNF)-α-[D-Gal N/lipopolysaccharide(LPS)]induced apoptosis.Liver injury was assessed by measurement of serum transaminases and histological analysis.Apoptosis induction was quantified by cleaved PARP staining and Western blotting of activated caspases.Nuclear factor(NF)-κB,ERK,Akt and jun amino-terminal kinases signaling were assessed.Primary Hepatocytes were isolated by two step-collagenase perfusion and treated with recombinant TNF-αand with the CD95-ligand Jo2.Cell viability was analyzed by MTT-assay.RESULTS:Livers of CYLD-/-mice showed increased anti-apoptotic NF-κB signaling.In both applied liver injury models CYLD-/-mice showed a significantly reduced apoptosis sensitivity.After D-Gal N/LPS treatment CYLD-/-mice exhibited significantly lower levels of alanine aminotransferase(ALT)(295 U/L vs 859 U/L,P<0.05)and aspartate aminotransferase(AST)(560 U/L vs 1025 U/L,P<0.01).After Jo injection CYLD-/-mice showed 2-fold lower ALT(50 U/L vs 110 U/L,P<0.01)and lower AST(250 U/L vs 435 U/L,P<0.01)serumlevels compared to WT mice.In addition,isolated CYLD-/-primary murine hepatocytes(PMH)were less sensitive towards death receptor-mediated apoptosis and showed increased levels of Bcl-2,XIAP,c IAP1/2,survivin and c-FLIP expression upon TNF-and CD95-receptor triggering,respectively.Inhibition of NF-κB activation by the inhibitor of NF-κB phosphorylation inhibitor BAY 11-7085 inhibited the expression of antiapoptotic proteins and re-sensitized CYLD-/-PMH towards TNF-and CD95-receptor mediated cell death.CONCLUSION:CYLD is a central regulator of apoptotic cell death in murine hepatocytes by controlling NF-κB dependent anti-apoptotic signaling.     

Serological monitoring of protection of sheep against Echinococcus granulosus induced by the EG95 vaccine

Although immunity to Echinococcus granulosus in sheep has been shown to be antibody-mediated and complement-dependent and can be passively transferred in colostrum, in animals vaccinated with EG95, the relationship between protection against an oral challenge infection with E. granulosus eggs and anti-EG95 IgG ELISA absorbance values at the time of challenge has not been satisfactorily proven. Using a combination of results from three EG95 vaccination trials, we have found that the IgG ELISA absorbance at the time of challenge infection explains approximately 50% (P ≤ 0·001) of the variability in the percentage protection against an oral challenge with E. granulosus eggs (transformed with arcsin).     

电针“百会”“神庭”对血管性痴呆大鼠学习记忆能力和海马突触结构与相关蛋白表达水平的影响

目的 观察电针“百会”“神庭”对血管性痴呆（vascular dementia,VD）大鼠学习和记忆功能的影响,并从突触结构及突触相关蛋白表达水平的角度揭示其作用机制。方法 将35只雄性SD大鼠随机分为假手术组、模型组、电针穴位组、电针非穴位组和奥拉西坦组,每组7只。采用改良双侧颈动脉结扎模型,电针穴位组大鼠选择“百会”“神庭”两穴治疗,电针非穴位组大鼠选择固定非穴位刺激,每次电针30 min,每日1次,连续干预14 d;奥拉西坦组大鼠选择腹腔注射奥拉西坦,50 mg/kg,每日1次,连续14 d。采用Morris水迷宫检测各组大鼠学习和空间记忆能力;透射电子显微镜观察各组大鼠海马CA1区突触结构;Western blot检测各组大鼠海马突触后致密蛋白95（postsynaptic density protein 95, PSD95）、GluA1、GluN2B和磷酸化GluN2B蛋白表达水平。结果 与假手术组比较,模型组大鼠学习期逃避潜伏时间延长,测试期跨越平台次数减少,目标象限停留时间显著缩短,大脑质量显著增加,海马CA1区突触结构数明显减少,海马PSD95、GluA1、GluN2B和磷酸化GluN2B蛋白表达水平均显著降低,差异均有统计学意义（P＜0.05）;与模型组比较,电针穴位组大鼠的学习期逃避潜伏时间缩短,测试期跨越平台次数增加,目标象限停留时间延长,大脑质量降低,CA1区突触结构数增多,海马PSD95、GluA1、GluN2B和磷酸化GluN2B蛋白表达水平增加,差异均有统计学意义（P＜0.05）。结论 电针“百会”“神庭”能改善VD大鼠的学习记忆功能,改变海马突触结构,分子机制可能和增加突触蛋白PSD95、GluA1和GluN2B的蛋白表达水平相关。     

Preconditioning ischemia attenuates increased neurexin-neuroligin1-PSD-95 interaction after transient cerebral ischemia in rat hippocampus

In this study, we investigated the interactions between synapse adhesion molecules neurexin, neuroligin1, neuroligin2 and postsynaptic density protein 95 (PSD-95) in transient cerebral ischemia and possible regulatory mechanism of these interactions. Our data show that preconditioning ischemia can down-regulate the increased neurexin-neuroligin1-PSD-95 interaction induced by ischemia injury and exerts a neuroprotective effect. Pre-treatment of N-methyl-D-aspartate (NMDA) receptor antagonist ketamine can demolish this neuroprotective effect of preconditioning by increasing neurexin-neuroligin1-PSD-95 interaction. These results indicate that the neurexin-neuroligin1-PSD-95 is an important signalling module in ischemic injury and a novel possible target in therapeutics of brain ischemia.     

Can we increase the speed and efficacy of antidepressant treatments? Part II. Glutamatergic and RNA interference strategies

In the second part we focus on two treatment strategies that may overcome the main limitations of current antidepressant drugs. First, we review the experimental and clinical evidence supporting the use of glutamatergic drugs as fast-acting antidepressants. Secondly, we review the involvement of microRNAs (miRNAs) in the pathophysiology of major depressive disorder (MDD) and the use of small RNAs (e.g.., small interfering RNAs or siRNAs) to knockdown genes in monoaminergic and non-monoaminergic neurons and induce antidepressant-like responses in experimental animals.The development of glutamatergic agents is a promising venue for antidepressant drug development, given the antidepressant properties of the non-competitive NMDA receptor antagonist ketamine. Its unique properties appear to result from the activation of AMPA receptors by a metabolite [(2 S,6 S;2 R,6 R)-hydroxynorketamine (HNK)] and mTOR signaling. These effects increase synaptogenesis in prefrontal cortical pyramidal neurons and enhance serotonergic neurotransmission via descending inputs to the raphe nuclei. This view is supported by the cancellation of ketamine's antidepressant-like effects by inhibition of serotonin synthesis.We also review existing evidence supporting the involvement of miRNAs in MDD and the preclinical use of RNA interference (RNAi) strategies to target genes involved in antidepressant response. Many miRNAs have been associated to MDD, some of which e.g., miR-135 targets genes involved in antidepressant actions. Likewise, SSRI-conjugated siRNA evokes faster and/or more effective antidepressant-like responses. Intranasal application of sertraline-conjugated siRNAs directed to 5-HT_1A receptors and SERT evoked much faster changes of pre- and postsynaptic antidepressant markers than those produced by fluoxetine.     

基于“成分-靶点-通路”的枸杞子调控年龄相关性黄斑变性作用机制研究

目的采用网络药理学方法探讨枸杞子改善年龄相关性黄斑变性(age-related macular degeneration,AMD)的活性成分及作用机制。方法以检索TCMSP数据库和查阅文献获得的枸杞子潜在活性成分为研究对象,通过Swiss Target Prediction平台、GeneCards数据库、OMIM数据库、DDT数据库和Drugbank数据库预测活性成分的潜在靶点;应用Metascape平台对潜在靶点进行基因本体(gene ontology,GO)功能富集分析和京都基因与基因组百科全书(Kyoto encyclopedia of genes and genomes,KEGG)富集分析;运用String数据库和Cytoscape软件构建蛋白相互作用(protein-protein interaction,PPI)网络和"药物-成分-靶点-通路-疾病"网络;考察枸杞子不同提取部位对碘酸钠诱导的人视网膜色素上皮细胞ARPE-19活力的影响,以及对脂多糖诱导的小鼠小胶质细胞系BV2中炎症因子表达的影响。结果枸杞子中的88个活性成分通过调控血管内皮生长因子A(vascular endothelial growth factor A,VEGFA)、白细胞介素-8(interleukin-8,IL-8)、白细胞介素-6(interleukin-6,IL-6)、肿瘤坏死因子(tumor necrosis factor,TNF)、基质金属蛋白酶-9(matrix metalloproteinase-9,MMP-9)等靶点,参与氧化应激、炎症反应等生物学过程,影响晚期糖基化终末产物(advanced glycation end products,AGE)-晚期糖基化终末产物受体(receptor for advanced glycation end products,RAGE)、IL-17、TNF等信号通路发挥改善AMD的作用。枸杞子95%乙醇提取部位能够显著提高碘酸钠诱导的ARPE-19细胞活力(P<0.001),并显著降低脂多糖诱导的BV2细胞中IL-6、IL-1β、TNF-αmRNA表达水平(P<0.05、0.01、0.001)。结论枸杞子中多种成分具有影响AMD相关靶点的潜在作用,枸杞子能够通过改善氧化损伤、抑制炎症反应治疗AMD,为后续深入研究枸杞子中不同活性成分调节AMD的作用机制提供依据。     

NMDAR/PSD-95/nNOs复合体及其解偶联剂在治疗缺血性卒中的应用

缺血性脑卒中是一种高死亡率、高致残率、高复发率的疾病。目前认为,脑卒中是由各种血管性病因引起的急性或局灶性脑功能障碍,且持续时间超过24 h或引起死亡的临床症候群。随着对脑卒中发病机制的深入研究,其治疗药物也日新月异,该文综合国内外文献,根据NMDAR/PSD-95/nNOs复合体结构特点及其如何在缺血性脑卒中产生病理作用,阐明新型解偶联药物在治疗缺血性卒中的应用前景。     

Investigation into the effects of prenatal alcohol exposure on postnatal spine development and expression of synaptophysin and PSD95 in rat hippocampus

Ethanol is known as a potent teratogen responsible for the fetal alcohol syndrome characterized by cognitive deficits especially pronounced in juveniles but ameliorating in adults. Since the mechanisms of these deficits and following partial recovery are not fully elucidated, the aim of the present study was to investigate the process of synaptogenesis in the hippocampus over the first two months of life in control and fetal-alcohol rats. Ethanol was delivered to the pregnant dams by intragastric intubation throughout 7–21 gestation days at the daily dose of 6 g/kg generating a mean blood alcohol level of 246.6 ± 40.9 mg/dl on gestation day 20. The spine densities as well as the expression of pre- and postsynaptic proteins, synaptophysin (SYP) and PSD-95 protein, were evaluated for three distinct hippocampal regions: CA1, CA2+3, and DG and four postnatal days: PD1, PD10, PD30 and PD60, independently. Our results confirmed an intensive synaptogenesis within the brain spurt period (first 10 postnatal days), however, the temporal pattern of changes in the SYP and PSD-95 expression was different. The ethanol exposure during half of the 1st and the whole 2nd human trimester equivalent resulted in an overall trend toward lower values of synaptic indices at PD1 with a fast recovery from these deficits observed already at PD10. At PD30, around the age when the most pronounced behavioral deficits have been previously reported in juvenile fetal-alcohol subjects, no significant changes were found in either the hippocampal levels of synaptic proteins or in the spine density in principal hippocampal neurons.