昆仑雪菊原花青素对四氯化碳致小鼠肝损伤的保护作用

本文研究了昆仑雪菊原花青素(KCPC)对四氯化碳(CCl4)致小鼠急性肝损伤的保护作用。采用CCl4建立肝损伤模型,观察KCPC对肝损伤小鼠肝脏病理变化和肝脏指数等的影响;检测小鼠丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)水平和超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性及丙二醛(MDA)含量;采用Fe2+-Vc诱导线粒体细胞膜肿胀,分析KCPC对抑制线粒体肿胀的作用,并检测琥珀酸脱氢酶(SDH)活性。结果表明,KCPC中剂量组及高剂量组绝大部分肝组织结构正常,而模型组的小鼠肝组织出现病变坏死,而且血清中ALT、AST显著上升(p0.01)。此外,KCPC高剂量组(800 mg/kg)的ALT、AST活性分别比模型组降低了82.46%和69.41%,且SOD、GSH-Px活性分别增加了101.08%和92.13%(p0.01),MDA含量降低了45.16%(p0.01)。KCPC还具有一定抑制线粒体肿胀的能力,且400mg/kg剂量组的SDH活性为模型组的1.22倍。上述结果表明,KCPC对CCl4诱导的小鼠肝损伤具有保护作用,其机制可能与提高抗氧化酶的活性有关。     

基于DNA测序方法检测生鲜肉中5种动物源性成分

目的建立生鲜肉中猪、牛、羊、鸡、鸭源性成分的DNA测序鉴别方法,并对采集自北京各地区生鲜肉品进行检测验证。方法合成动物线粒体上12S rRNA、cytochrome b、cytochrome c oxidase基因引物,建立猪、牛、羊、鸡、鸭源性成分的DNA测序鉴别方法,并对50份猪、牛、羊、鸡、鸭肉品进行检测。结果使用线粒体上12S rRNA、cytochrome b、cytochrome c oxidase基因引物对猪、牛、羊、鸡、鸭肉品进行扩增,分别获得456、400和710 bp大小的DNA片段。只有12S rRNA基因引物均可对此5种动物源性成分扩增且效果良好。扩增产物进行序列测定。根据序列构建的系统进化树发现,此方法可有效区分样品中猪、牛、羊、鸡、鸭源性成分。结论此方法快速、简便,可准确检测50种生鲜肉样品中的动物源性成分,作为肉类鉴别的新方法。     

荧光定量PCR方法检测畜肉食品中鸭源性成分

目的 建立一种快速、特异、灵敏的鸭源性成分检测方法。方法 本研究以鸭线粒体基因全序列为靶位点设计引物和探针, 进行荧光定量PCR扩增, 建立鸭源性成分检测方法; 以常见畜禽肉包括羊肉、牛肉、鸡肉、鹅肉、猪肉、兔肉、马肉、鹿肉等参考动物物种作特异性检测; 以50 mg/kg羊肉DNA作为稀释液对鸭肉DNA进行梯度稀释, 做灵敏度检测。结果 该方法能够有效对鸭源性成分进行快速检测, 具有较强的特异性, 灵敏度较高(可达0.1 μg/kg)并且羊肉成分的存在对鸭肉灵敏度检测没有影响。结论 该方法特异性强, 灵敏度高, 可以快速、准确检测畜肉食品中含有的鸭源性成分。     

植物的线粒体基因组研究

线粒体作为最重要的细胞器之一,是细胞氧化磷酸化进行的场所。它有其自身的基因组,也有其独立的转录、翻译体系,甚至其使用的遗传密码也与核基因组的有所不同。本文介绍了高等植物线粒体基因组的特点及研究现状。由于高等植物的细胞质雄性不育性与线粒体ＤＮＡ有密切关系,本文对此也作了阐述。     

低温驯化速度对鲫鱼离水储藏酶活性的影响

为研究低温驯化及储藏温度对鲫鱼活体离水后储藏的影响,成年鲫鱼(Carassius carassius)放置于水箱中,采用每小时5℃和1℃速率,由25℃匀速降温降至0℃,分别在4℃和0℃冷库中离水储藏24 h,测定鲫鱼新陈代谢及抗氧化相关酶的活力,并探讨低温驯化及离水储藏对鱼体生理状态的影响。结果表明,1℃/h降温有利于乳酸脱氢酶(LDH)活力的保存。经过1℃/h降温驯化后,0℃储藏异柠檬酸脱氢酶活力功能得到了一定保存,脑琥珀酸脱氢酶(SDH)未受影响。丙氨酸氨基转移酶(ALT)活力体现为受储藏温度影响,0℃下其活力得到保存。0℃储藏导致丙二醛(MDA)的积聚,同时低温储藏中血液过氧化氢酶(CAT)集聚而肝脏未表现出明显变化。     

Novel Models of Crohn’s Disease Pathogenesis Associated with the Occurrence of Mitochondrial Dysfunction in Intestinal Cells

Crohn’s disease remains one of the challenging problems of modern medicine, and the development of new and effective and safer treatments against it is a dynamic field of research. To make such developments possible, it is important to understand the pathologic processes underlying the onset and progression of Crohn’s disease at the molecular and cellular levels. During the recent years, the involvement of mitochondrial dysfunction and associated chronic inflammation in these processes became evident. In this review, we discuss the published works on pathogenetic models of Crohn’s disease. These models make studying the role of mitochondrial dysfunction in the disease pathogenesis possible and advances the development of novel therapies.     

Identification and characterization of the type 2C protein phosphatase Ptc4p in the human fungal pathogen Candida albicans

Type 2C protein phosphatases (PP2C) are monomeric enzymes and their activities require the presence of magnesium or manganese ions. There are seven PP2C genes, named from PTC1 to PTC7, in Saccharomyces cerevisiae. In the current study we identified the CaPTC4 gene in Candida albicans and demonstrated that the CaPtc4p protein is a typical PP2C enzyme, which is highly conserved in fungal species. Deletion of CaPTC4 renders Candida cells sensitive to sodium and potassium ions as well as to antifungal azole drugs. In addition, we have shown that CaPtc4p is localized in the mitochondrion, suggesting that CaPtc4p is likely to be involved in the regulation of a mitochondrial function related to ion homeostasis. Copyright © 2009 John Wiley & Sons, Ltd.     

Functional characterization of the PP2C phosphatase CaPtc2p in the human fungal pathogen Candida albicans

Type 2C protein phosphatases (PP2C) are monomeric enzymes and their activities require the presence of magnesium or manganese ion. There are seven PP2C‐like genes in Candida albicans. In this study, we demonstrate that CaPtc2p is a PP2C phosphatase. Surprisingly, in addition to the cytoplasmic localization, CaPtc2p is partially associated with mitochondria in yeast‐form and filamentous cells of C. albicans. Expression of CaPTC2 is developmentally regulated during the serum‐induced filamentation. Deletion of CaPTC2 renders C. albicans cells sensitive to SDS and azole antifungals, as well as the DNA methylation agent methylmethane sulphonate and the DNA synthesis inhibitor hydroxyurea. Therefore, CaPtc2p might fulfil multiple functions, including the regulation of mitochondrial physiology and checkpoint recovery from DNA damage in C. albicans cells. Copyright © 2010 John Wiley & Sons, Ltd.