Protective Effects of Pinostrobin on β-Amyloid-Induced Neurotoxicity in PC12 Cells

Beta-Amyloid peptide (A??), a major protein component of brain senile plaques in Alzheimer??s disease (AD), has been considered as a critical cause in the pathogenesis of AD. Pinostrobin, a potent flavonoid inducer, is the major and most active ingredient of Folium cajani. The present study aimed to investigate whether pinostrobin could provide protective effect against A??_25-35-induced neurotoxicity in cultured rat pheochromocytoma (PC12) cells. The PC12 cells were pretreated with different concentrations of pinostrobin for 2?h, followed by the challenge with 20???M A??_25?C35 for 24?h. The results showed that pretreatment with pinostrobin significantly elevated cell viability, decreased the lactate dehydrogenase activity, the levels of intracellular reactive oxygen species and calcium, and mitochondrial membrane potential in A??_25?C35-treated PC12 cells. In addition, pinostrobin significantly suppressed the formation of DNA fragmentation and increased the ratio of Bcl-2/Bax. These results indicate that pinostrobin was able to exert a neuroprotective effect against A??_25?C35-induced neurotoxicity in PC12 cells, at least in part, via inhibiting oxidative damage and calcium overload, as well as suppressing the mitochondrial pathway of cellular apoptosis.     

调节性T细胞的分化及其影响因素

调节性T细胞是近年发现的一种具有免疫抑制活性的CD4+T细胞亚群,它们可以在胸腺中被选择分化,也可以在外周淋巴组织内由转化生长因子-β等细胞因子诱导分化。本文就调节性T细胞分化过程的关键信号通路及影响因素进行综述。调控调节性T细胞的分化过程能够影响其在体内的数目,可通过对其数量的干预,为自身免疫性疾病、免疫监视、排斥反应及变态反应等相关疾病提供可能的治疗靶点。     

野生甜瓜'云甜-930'对白粉病抗性的遗传分析

以经过多代自交选育的高抗白粉病材料野生甜瓜'云甜-930'(P1)与感病栽培甜瓜'华莱士'(P2)组配,构建了P1、P2、F1、B1、B2和F2 6个世代,对大棚栽培条件下各世代材料的白粉病自然发病状况进行考察,用植物数量性状主基因+多基因混合遗传模型的多世代联合分析法,研究野生甜瓜'云甜-930'对白粉病的抗性遗传规律.结果显示:野生甜瓜'云甜-930'对白粉病的抗性遗传符合2对加性-显性-上位性主基因+加性-显性-上位性多基因混合遗传模型(E-0),2对主基因的加性效应相等,da和db均为-15.76,2对主基因的显性效应ha和hb分别为14.98和19.87,第2对主基因的显性效应大于第1对;2对主基因互作效应中除了显性×显性效应(l=-7.73)较小外,其它互作效应均较大,加性×加性效应i为31.46,加性×显性效应jab为-26.86,而显性×加性效应jba为-17.07.该组合的B1、B2和F2群体抗病性主基因遗传率分别为73.31%、69.15%和97.61%,多基因遗传率分别为18.83%、25.86%和0,环境变异在2.39%～7.86%之间.研究表明,野生甜瓜'云甜-930'对白粉病的抗性受2对加性-显性-上位性主基因+加性-显性-上位性多基因控制,同时还受到环境的影响.在甜瓜抗白粉病育种中,在F2代主基因的选择效率最高.     

ADAMTS-7,血管重塑中的新靶点(英文)

血管重塑是动脉粥样硬化和血管再狭窄发病中的一个重要的病理生理学过程。越来越多的证据表明,具有降解细胞外基质能力的酶在血管重塑中发挥着重要的作用。含I型血小板反应蛋白的解聚素和金属蛋白酶(a disintegrin and metalloproteinase with thrombospondin motifs,ADAMTS)家族是一类最近被克隆的金属蛋白酶家族,该家族成员同样具备降解细胞外基质的能力。ADAMTS家族由19个家族成员组成,参与了一系列的正常生理学功能,如发育、血管新生和凝血等。而ADAMTS家族成员的异常表达通常会引发各种疾病,如关节炎、肿瘤、凝血功能障碍性紫癜。本文从ADAMTS家族第七个成员——ADAMTS-7的结构、组织分布、调控、尤其是通过其底物软骨寡聚基质蛋白(cartilage oligomeric matrix protein,COMP)精细调控血管稳态几个方面综述了其在血管重塑中作用的最新研究进展。     

Decreased expression of the Ets family transcription factor Fli-1 markedly prolongs survival and significantly reduces renal disease in MRL/lpr mice

Increased Fli-1 mRNA is present in PBLs from systemic lupus erythematosus patients, and transgenic overexpression of Fli-1 in normal mice leads to a lupus-like disease. We report in this study that MRL/lpr mice, an animal model of systemic lupus erythematosus, have increased splenic expression of Fli-1 protein compared with BALB/c mice. Using mice with targeted gene disruption, we examined the effect of reduced Fli-1 expression on disease development in MRL/lpr mice. Complete knockout of Fli-1 is lethal in utero. Fli-1 protein expression in heterozygous MRL/lpr (Fli-1(+/-)) mice was reduced by 50% compared with wild-type MRL/lpr (Fli-1(+/+)) mice. Fli-1(+/-) MRL/lpr mice had significantly decreased serum levels of total IgG and anti-dsDNA Abs as disease progressed. Fli-1(+/-) MRL/lpr mice had significantly increased splenic CD8(+) and naive T cells compared with Fli-1(+/+) MRL/lpr mice. Both in vivo and in vitro production of MCP-1 were significantly decreased in Fli-1(+/-) MRL/lpr mice. The Fli-1(+/-) mice had markedly decreased proteinuria and significantly lower pathologic renal scores. At 48 wk of age, survival was significantly increased in the Fli-1(+/-) MRL/lpr mice, as 100% of Fli-1(+/-) MRL/lpr mice were alive, in contrast to only 27% of Fli-1(+/+) mice. These findings indicate that Fli-1 expression is important in lupus-like disease development, and that modulation of Fli-1 expression profoundly decreases renal disease and improves survival in MRL/lpr mice.     

用鲮鱼鱼苗代替鼠妇探究光对生物生活的影响

针对在广东等地的城市学校,开展初中阶段的第1个探究实验——“光对鼠妇生活的影响”中存在的困难,提出用鲮鱼鱼苗代替鼠妇的探究方案。实践表明,该材料更易得,操作更简单,需时更短,现象更明显,减小了教师实验前和实验后的工作量,提高了实验课的效率。     

Effects of Growing Location on the Contents of Main Active Components and Antioxidant Activity of Dasiphora fruticosa (L.) Rydb. by Chemometric Methods

Traditional Chinese Medicine (TCM) is a very important raw material source for natural medicines in China. The content and activity of active component are main indexes that evaluate the quality of TCM, however, they may vary with environmental factors. In this study, the effects of environmental factors on the active component contents and antioxidant activity of Dasiphora fruticosa collected from the five main growing areas of China were investigated. The contents of tannin, total flavonoids and rutin were determined to be 7.65 – 10.69%, 2.30 – 5.39% and 0.18 – 0.81%, respectively. Antioxidant activity was determined by DPPH assay, with the DPPH IC₅₀ values ranged from 8.791 to 32.534 μg mL^?1. In order to further explore the cause of these significant geographical variations, the chemometric methods including correlation analysis, principal component analysis, gray correlation analysis and path analysis were applied. The results showed that environmental factors had significant effect on the contents of active components and antioxidant activity. Rapidly available phosphorus (RAP) and rapidly available nitrogen (RAN) were common dominant factors, and a significant positive action existed between RAP and active components and antioxidant activity (P < 0.05). Contributed by their high active components and strong antioxidant activity, Bange in Tibet and Geermu in Qinghai Province were selected as a favorable growing location, respectively.     

Retracted: Icariin attenuates methotrexate chemotherapy-induced bone marrow microvascular damage and bone loss in rats

Methotrexate (MTX), a widely used antimetabolite in paediatric cancer to treatment, has been widely reported to cause bone loss and bone marrow (BM) microvascular (particularly sinusoids) damage. Investigations must now investigate how MTX-induced bone loss and microvasculature damage can be attenuated/prevented. In the present study, we examined the potency of icariin, an herbal flavonoid, in reducing bone loss and the dilation/damage of BM sinusoids in rats caused by MTX treatment. Groups of young rats were treated with five daily MTX injections (0.75 mg/kg) with and without icariin oral supplementation until Day 9 after the first MTX injection. Histological analyses showed a significant reduction in the bone volume/tissue volume (BV/TV) fraction (%) and trabecular number in the metaphysis trabecular bone of MTX-treated rats, but no significant changes in trabecular thickness and trabecular spacing. However, the BV/TV (%) and trabecular number were found to be significantly higher in MTX + icariin-treated rats than those of MTX alone-treated rats. Gene expression analyses showed that icariin treatment maintained expression of osteogenesis-related genes but suppressed the induction of adipogenesis-related genes in bones of MTX-treated rats. In addition, icariin treatment attenuated MTX-induced dilation of BM sinusoids and upregulated expression of endothelial cell marker CD31 in the metaphysis bone of icariin + MTX-treated rats. Furthermore, in vitro studies suggest that icariin treatment can potentially enhance the survival of cultured rat sinusoidal endothelial cells against cytotoxic effect of MTX and promote their migration and tube formation abilities, which is associated with enhanced production of nitric oxide.