CREB研究进展

CREB是cAMP应答元件结合蛋白(cAMPresponseelementbindingprotein)的简称,它于80年代后期被发现。CREB由341个氨基酸残基组成,分子量43000。分子结构分两个区域,N端区域与调节转录的功能有关,C端区域是与启动子结合的部位。CREB是CREBATF家族中的一个成员,它包括8种分子亚型,其中CREBα和CREBΔα最为重要。CREB是一种细胞核内调控因子,它通过自身磷酸化实现调节转录的功能。CREB与学习记忆分子神经机制的关系特别受到注意。CREB能促进果蝇和小鼠等动物长时程记忆的形成。开展对CREB在人类大脑记忆活动中功能的研究,是分子神经生物学家感兴趣的课题。     

Novel SNPs in <Emphasis Type="Italic">HSP70A1A</Emphasis> gene and the association of polymorphisms with thermo tolerance traits and tissue specific expression in Chinese Holstein cattle

Heat stress induces heat shock proteins (HSPs) expression and HSP70 family is one of them that have been reported to involve in cellular protection against heat stress. But whether there is any association of genetic variation in the HSP70A1A gene with thermo tolerance is unknown. PCR-SSCP and DNA sequencing were used to detect possible SNPs in HSP70A1A gene in 890 Chinese Holstein cattle. Three fragments were amplified and five novel mutations were found in HSP70A1A gene in Chinese Holstein cattle. G/A mutation was found at nucleotide 1524 in coding region that resulting two genotypes of AA and AB. T/C mutation was found at nucleotide 3494 in 3′-UTR resulting three genotypes of CC, CD and DD. The other three point mutations, G/C at nucleotide 6400, C/T at nucleotide 6600 and G/A at nucleotide 6601 were also found in 3′-UTR resulting six genotypes of EE, EF, FF, EG, FG and GG. Linkage disequilibrium (LD) analysis showed that the nucleotide 6400, 6600 and 6601 were in strong LD (D > 0.75). Association analysis indicated that AB, DD and FF genotype were the thermo tolerance genotype. SBYE Green I was used to quantify HSP70A1A mRNA expression in different tissues through quantitative real-time PCR assay. The results of the real-time PCR showed that the expression of HSP70A1A mRNA in the heart was significantly higher than that in the other tissues (P < 0.05). We presume that these mutations could be used in marker assisted selection for anti-heat stress cows in our breeding program.     

One SNP in the 3′-UTR of HMGB1 gene affects the binding of target bta-miR-223 and is involved in mastitis in dairy cattle

High-mobility group box protein 1 (HMGB1) gene has a universal sentinel function for nucleic acid-mediated innate immune responses and acts as a pathogenic mediator in the inflammatory disease. In an effort to identify the functional single-nucleotide polymorphism (SNP) in the 3′-untranslated region (UTR) of the bovine HMGB1 gene that affects the binding to its target microRNA, first, the expression of HMGB1 mRNA in different genotypes and its candidate bta-miR-223 was investigated. Quantitative real-time polymerase chain reaction results showed that the relative expression of HMGB1 mRNA in cows with the genotype GG is significantly higher than those in cows with the genotype AA (P?<?0.05). The expression of bta-miR-223 was significantly upregulated by 1.95-fold (P?<?0.05) in the bovine mastitis-infected mammary gland tissues compared with that in the healthy tissues. Subsequently, luciferase assay indicated that the HMGB1 expression was directly targeted by bta-miR-223 in human embryo kidney 293 T (HEK 293T)?cells. One novel SNP (g. +2776 A?>?G) in the HMGB1 3′-UTR, altering the binding of HMGB1 and bta-miR-223, was found to be associated with somatic count scores in cows. Taken together, the g. +2776 A?>?G-GG was an advantageous genotype which can be used as a candidate functional marker for mastitis resistance breeding program.     

四川大巴山野生蜡梅资源现状与保护利用

蜡梅属（Chimonanthus Lindley）植物为我国特有,是国家二级珍稀濒危植物,为全身是宝的落叶灌木树种。2004年1月、2006年9月和12月,以及2007年12月4次深入四川大巴山地区,采用踏查法对野生蜡梅资源的分布、生境、生物学性状、开发利用等状况进行了调查。结果发现,四川大巴山地区广泛分布着野生蜡梅原生林,其分布地域、面积和资源存量在我国野生蜡梅中均占有重要地位。该地区野生蜡梅原生而古老,株、叶、枝、花、果类型丰富多样。但是,存在开发利用误区,资源破坏严重,一些地方甚至濒临灭绝。结合当地经济、历史、文化特色,对有效保护和合理开发利用野生蜡梅资源,发展地方特色资源经济提出了相应的思路与建议。     

Presence and characterization of complement-like activity in the amphioxus Branchiostoma belcheri tsingtauense

The humoral fluid of Branchiostoma belcheri tsingtauense was examined for the presence of complement-like activity. The humoral fluid showed hemolytic activity for rabbit erythrocytes and those from species representing mammals, birds, amphibians and fish, but not sensitized sheep erythrocytes. There was no relationship between phylogeny of the target erythrocytes and degree of hemolysis. The hemolytic activity was optimally assayed at 20 degrees C, at pH 7.5, and in the presence of 10 mM Mg2+. The hemolytic activity was Mg2+-dependent and heat-sensitive, and was abrogated by treatment with rabbit anti-human C3 serum, zymosan, methylamine, hydrazine, and phenylmethylenesulfonyl fluoride. In addition, Western blotting and titration by turbidimetric immunoassay (TIA) revealed that amphioxus humoral fluid contained C3 component, and its concentration is about 1.17 mg/ml, which is comparable to C3 concentration in human or dog sera. These suggest that the hemolytic activities displayed by amphioxus humoral fluid appear to represent the vertebrate complement system probably operating via the alternative pathway.     

秦巴山区生态农业类型及效益

陕西省安康地区位于全国最大的一块贫困片秦巴山区,北靠秦岭主脊,南踞大巴山北坡,汉水横贯其中,形成“两山夹一川”的地貌特征。全地区总面积２．３３９１×１０４ｋｍ２,其中耕地和水域面积约各占１０％,林地和荒山面积约各占４０％。特别是荒山面积平均一人０６１ｈａ,可利用的土地资源十分丰富。据调查和国土资源资料分析,在山区有３０％～４０％的农户单家独居,其居住的方圆土地规模一般为２００～２６７ｈａ,多的可达６６７ｈａ以上,形成一户一条沟,一户一条梁,一户一面坡的人口与土地资源的分布格局。在农业生态…     

Enhanced infarct myocardium repair mediated by thermosensitive copolymer hydrogel-based stem cell transplantation

Mesenchymal stem cell (MSC) transplantation by intramyocardial injection has been proposed as a promising therapy strategy for cardiac repair after myocardium infarction. However, low retention and survival of grafted MSCs hinder its further application. In this study, copolymer with N-isopropylacrylamide/acrylic acid/2-hydroxylethyl methacrylate-poly(ɛ-caprolactone) ratio of 88:9.6:2.4 was bioconjugated with type I collagen to construct a novel injectable thermosensitive hydrogel. The injectable and biocompatible hydrogel-mediated MSC transplantation could enhance the grafted cell survival in the myocardium, which contributed to the increased neovascularization, decreased interstitial fibrosis, and ultimately improved heart function to a significantly greater degree than regular MSC transplantation. We suggest that this novel hydrogel has the potential for future stem cell transplantation.     

热休克转录因子1与机体耐热性的相关研究

热休克转录因子1(HSF1)能够启动各种热休克蛋白基因的诱导表达,这对防止机体免受热应激损伤具有重要的意义。从HSF1的结构、功能及活化过程等几个方面阐述了HSF1的生理特征及其与机体耐热性能之间的关系。     

Hydrogen sulfide inhibits the development of atherosclerosis with suppressing CX3CR1 and CX3CL1 expression

Hydrogen sulfide, as a novel gaseous mediator, has been suggested to play a key role in atherogenesis. However, the precise mechanisms by which H(2)S affects atherosclerosis remain unclear. Therefore, the present study aimed to investigate the potential role of H(2)S in atherosclerosis and the underlying mechanism with respect to chemokines (CCL2, CCL5 and CX3CL1) and chemokine receptors (CCR2, CCR5, and CX3CR1) in macrophages. Mouse macrophage cell line RAW 264.7 or mouse peritoneal macrophages were pre-incubated with saline or NaHS (50 μM, 100 μM, 200 μM), an H(2)S donor, and then stimulated with interferon-γ (IFN-γ) or lipopolysaccharide (LPS). It was found that NaHS dose-dependently inhibited IFN-γ or LPS-induced CX3CR1 and CX3CL1 expression, as well as CX3CR1-mediated chemotaxis in macrophages. Overexpression of cystathionine γ-lyase (CSE), an enzyme that catalyzes H(2)S biosynthesis resulted in a significant reduction in CX3CR1 and CX3CL1 expression as well as CX3CR1-mediated chemotaxis in stimulated macrophages. The inhibitory effect of H(2)S on CX3CR1 and CX3CL1 expression was mediated by modulation of proliferators-activated receptor-γ (PPAR-γ) and NF-κB pathway. Furthermore, male apoE(-/-) mice were fed a high-fat diet and then randomly given NaHS (1 mg/kg, i.p., daily) or DL-propargylglycine (PAG, 10 mg/kg, i.p., daily). NaHS significantly inhibited aortic CX3CR1 and CX3CL1 expression and impeded aortic plaque development. NaHS had a better anti-atherogenic benefit when it was applied at the early stage of atherosclerosis. However, inhibition of H(2)S formation by PAG increased aortic CX3CR1 and CX3CL1 expression and exacerbated the extent of atherosclerosis. In addition, H(2)S had minimal effect on the expression of CCL2, CCL5, CCR2 and CCR5 in vitro and in vivo. In conclusion, these data indicate that H(2)S hampers the progression of atherosclerosis in fat-fed apoE(-/-) mice and downregulates CX3CR1 and CX3CL1 expression on macrophages and in lesion plaques.