LPS诱导肝细胞LO2释放HMGB1蛋白的研究

以人单核巨噬细胞系U937细胞为对照,探讨肝细胞LO2分泌晚期炎症介质高迁移率族蛋白HMGB1过程的特点.400 μg/L LPS作用于人U937细胞和LO2细胞,MTT和荧光TUNNEL结果显示0～24 h,两种细胞均未见明显坏死和凋亡.RT-PCR结果表明LO2细胞HMGb1 mRNA表达水平高于相应对照组的时相(20 h)晚于U937细胞(16 h).Western blOT显示LO2细胞上清中检测到HMGB1蛋白的时相(16 h)晚于U937细胞(8h);两者上清HMGB1蛋白水平呈时间依赖性,但U937细胞分泌HMGB1蛋白的量占有绝对优势.细胞免疫荧光观察到两者均有HMGB1从细胞核向胞浆移位的现象,但LO2细胞晚于U937细胞.由此可见,LPS诱导肝细胞分泌晚期炎症介质HMGB1具有时相晚、量少的特点,且其分泌HMGB1的过程与HMGB1蛋白移位有关,而并不依赖于细胞坏死与凋亡.     

LPS诱导肝细胞L02释放HMGB1蛋白的研究

以人单核巨噬细胞系U937细胞为对照,探讨肝细胞L02分泌晚期炎症介质高迁移率族蛋白HMGB1过程的特点.400μg/L LPS作用于人U937细胞和L02细胞,MTT和荧光TUNEL结果显示0～24 h,两种细胞均未见明显坏死和凋亡.RT-PCR结果表明L02细胞HMGB1 mRNA表达水平高于相应对照组的时相(20 h)晚于U937细胞(16 h).Western blot显示L02细胞上清中检测到HMGB1蛋白的时相(16 h)晚于U937细胞(8h);两者上清HMGBl蛋白水平呈时间依赖性,但U937细胞分泌HMGB1蛋白的量占有绝对优势.细胞免疫荧光观察到两者均有HMGB1从细胞核向胞浆移位的现象,但L02细胞晚于U937细胞.由此可见,LPS诱导肝细胞分泌晚期炎症介质HMGB1具有时相晚、量少的特点,且其分泌HMGB1的过程与HMGB1蛋白移位有关,而并不依赖于细胞坏死与凋亡.     

高迁移率族蛋白B1在炎症性疾病中的研究进展

高迁移率族蛋白B1(high mobility group box 1 protein,HMGB1)是广泛存在于真核细胞核内的非组蛋白染色体结合蛋白,因其在聚丙烯酰胺凝胶电泳(PAGE)中迁移速度快而得名。近年来的研究表明,HMGB1作为一种重要的晚期炎症介质,在多种急慢性炎症中均有表达。本文就高迁移率族蛋白B1的结构、释放、致炎作用、与炎症性疾病的关系以及炎症时对高迁移率族蛋白B1的干预措施等方面研究近况做一综述。     

促炎因子调控紧密连接的研究进展

紧密连接存在于所有上皮或内皮细胞间连接的最顶端,是物质经过旁细胞途径进行物质转运的结构基础,具有"屏障"和"栅栏"的作用。在炎症及免疫因素介导的多种疾病中,如炎症性肠病、囊肿性纤维化、舍格伦综合征和神经系统炎症等,患者血清及疾病累及的上皮或内皮组织均出现多种促炎因子含量升高。促炎因子作用于相关的上皮或内皮组织,通过影响紧密连接蛋白的表达、结构和功能从而调控上皮或内皮的旁细胞途径通透性,是炎症性疾病的一个重要的发病机制。本文重点综述了促炎因子对肠道、呼吸道、唾液腺上皮以及脑微血管内皮紧密连接的调控及其相关分子机制。     

高迁移率族蛋白B1与动脉粥样硬化

越来越多的研究表明,炎症反应在动脉粥样硬化(Atherosclerosis,AS)的发生发展中起着至关重要的作用。而高迁移率族蛋白B1(HMGB1)作为一种重要的炎性介质和促炎细胞因子,它不仅可以通过活化细胞而主动分泌,还可以通过损伤坏死细胞被动释放到胞外,从而介导炎症反应。近年来,HMGB1在AS发病机制中的作用备受关注。大量研究表明,从炎症反应开始到斑块破裂及血栓形成的各个时期中,HMGB1均发挥重要的作用。本文就近年来HMGB1在AS发病机制中作用的研究做简要地综述。     

综述:炎症小体信号通路的负调控

炎症小体(inflammasomes)活化后产生的IL-1β和IL-18等促炎因子对天然免疫和适应性免疫具有重要作用.炎症小体持续活化可引起促炎因子过度表达,导致慢性炎症和自身免疫疾病的发生.正常生理状态下,机体存在多种炎症小体负调机制,以维持免疫反应平衡.病理状态下,感染机体的病原微生物通过多种途径抑制炎症小体信号通路的活化及促炎因子的产生,以利于免疫逃逸.本文综述了机体和病原微生物对炎症小体信号通路的负调控机理.阐明炎症小体信号通路负调控机制将为感染性疾病及其他炎症小体相关炎症性疾病的治疗提供策略.     

炎症小体信号通路的负调控

炎症小体(inflammasomes)活化后产生的IL-1β和IL-18等促炎因子对天然免疫和适应性免疫具有重要作用.炎症小体持续活化可引起促炎因子过度表达,导致慢性炎症和自身免疫疾病的发生.正常生理状态下,机体存在多种炎症小体负调机制,以维持免疫反应平衡.病理状态下,感染机体的病原微生物通过多种途径抑制炎症小体信号通路的活化及促炎因子的产生,以利于免疫逃逸.本文综述了机体和病原微生物对炎症小体信号通路的负调控机理.阐明炎症小体信号通路负调控机制将为感染性疾病及其他炎症小体相关炎症性疾病的治疗提供策略.     

高迁移率族蛋白B1的胞外作用与免疫效应

高迁移率族蛋白B1(HMGB1)是一种高度保守的核蛋白,具有调控DNA稳定、复制、转录及翻译等功能.近年来的研究表明,它通过主动或被动的方式被释放至细胞外,并作为一种晚期炎症介质,参与脓毒症等炎症性疾病的发病过程,同时也可作为一种免疫"预警信号"调控机体免疫反应.本文综述了HMGB1的结构、分泌机制、受体信号通路及其对细胞免疫的调控作用.     

高迁移率族蛋白B1在脓毒症和创伤后炎症反应中的作用

高迁移率族蛋白B1(high mobility group box-1 protein, HMGB1)是一种多功能核蛋白,从细胞中释放出来时,作为一种典型的预警蛋白或损伤相关分子模式(damage-associated molecular pattern, DAMP)分子发挥着多种功能。HMGB1多种功能的发挥主要依赖于其在细胞中的定位,包括细胞核、细胞质以及通过主动分泌或被动释放到细胞外。在脓毒症和创伤等多种应激和疾病过程中,HMGB1在细胞中的定位发生动态变化,这一过程受翻译后修饰的调控,发挥着不同的作用。现就HMGB1的不同定位和相应功能在脓毒症和创伤所致炎症反应中的作用作一概述。     

HMGB1与冠心病关系的研究进展

高迁移率族蛋白B1(high mobility group box1protein,HMGB1)是一种高度保守的核内非组蛋白,可由致病因素引发细胞被动释放或损伤、凋亡和坏死细胞主动分泌而产生。HMGB1可以在真核细胞坏死过程中被释放到细胞外。越来越多的研究证明,HMGB1是一种重要的潜在炎性介质,通过与其特异性受体结合而发挥着重要的炎症细胞因子作用。近年来研究表明,HMGB1通过参与炎症过程而影响动脉粥样硬化斑块的进展。因此,HMGB1可能是机体冠状动脉炎性疾病的重要靶点。本文对HMGB1及其作用机制进行综述,为心血管疾病的预防和治疗提供文献依据。     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.