寒冷刺激支气管上皮细胞产生外泌体促肺成纤维细胞表达气道重塑相关因子

外泌体可由多种细胞分泌,是具有多种生物学功能的细胞外囊泡,但其在气道重塑中的作用尚不明确。为探讨经寒冷刺激的人支气管上皮细胞（BEAS-2B）分泌的外泌体对人胚肺成纤维细胞(HLF1)气道重塑相关因子表达的影响,收集BEAS-2B细胞株培养液提取外泌体,利用透射电镜及Western印迹对外泌体进行其大小、形态及标志性蛋白的检测;提取的外泌体与HLF1共同培育,分别设置空白对照组、正常对照组（加入未作干预的BEAS 2B细胞所产的外泌体）及寒冷刺激组（加入经寒冷刺激后的BEAS-2B细胞所产的外泌体）。运用Real-time-PCR及Western印迹技术,分别检测各组HLF1表达FGF-2、TNF-α、MMP-9的mRNA及蛋白情况。结果显示,提取BEAS-2B细胞分泌的外泌体为直径小于100 nm的圆形或椭圆形结构,并表达外泌体标志性蛋白CD9、TSG101、ALIX;寒冷刺激组24 h后,其FGF-2、TNF-α、MMP-9的mRNA及蛋白表达均显著高于空白对照组及正常对照组（均P<0.05）。本研究结果表明,BEAS-2B细胞能够释放外泌体;经寒冷刺激后的BEAS 2B细胞所释放的外泌体可以携带并传递生物信号,诱导HLF1表达气道重塑相关因子。     

Brd4‐Brd2 isoform switching coordinates pluripotent exit and Smad2‐dependent lineage specification

Pluripotent stem cells (PSCs) hold great clinical potential, as they possess the capacity to differentiate into fully specialised tissues such as pancreas, liver, neurons and cardiac muscle. However, the molecular mechanisms that coordinate pluripotent exit with lineage specification remain poorly understood. To address this question, we perform a small molecule screen to systematically identify novel regulators of the Smad2 signalling network, a key determinant of PSC fate. We reveal an essential function for BET family bromodomain proteins in Smad2 activation, distinct from the role of Brd4 in pluripotency maintenance. Mechanistically, BET proteins specifically engage Nodal gene regulatory elements (NREs) to promote Nodal signalling and Smad2 developmental responses. In pluripotent cells, Brd2‐Brd4 occupy NREs, but only Brd4 is required for pluripotency gene expression. Brd4 downregulation facilitates pluripotent exit and drives enhanced Brd2 NRE occupancy, thereby unveiling a specific function for Brd2 in differentiative Nodal‐Smad2 signalling. Therefore, distinct BET functionalities and Brd4‐Brd2 isoform switching at NREs coordinate pluripotent exit with lineage specification.     

温度、湿度对黄喉拟水龟胚胎发育的影响

在9种不同温湿度组合条件（25 ℃和-12 kPa、29 ℃和-12 kPa、33 ℃和-12 kPa、25 ℃和-150 kPa、29 ℃和-150 kPa、33 ℃和-150 kPa、25 ℃和-300 kPa、29 ℃和-300 kPa、33 ℃和-300 kPa）下孵化了黄喉拟水龟卵,研究了温度对黄喉拟水龟卵孵出幼体特征的影响及其与湿度的相互作用对孵化期、孵化成功率和孵出幼体特征的影响.结果表明：黄喉拟水龟卵的初始质量、孵化温度、湿度及温湿度相互作用均显著影响孵化过程中卵质量的增加;同一温度下,孵化湿度越高,卵的终末质量越大;而孵化卵的终末质量与孵化温度并不呈线性相关;孵化温度显著影响黄喉拟水龟卵的孵化期,温度越高、孵化期越短,孵化湿度及温湿度相互作用对孵化期的影响不显著;孵化温度和湿度显著影响孵化成功率和卵壳龟裂率;25 ℃和33 ℃处理组孵出幼体中发现畸形个体,而29 ℃处理组中未发现;孵化温度显著影响孵出幼体的质量、背甲长和宽、腹甲长和宽、体高和尾长;孵化湿度只对孵出幼体的背甲长有影响,对其他被检测的幼体特征无显著影响;温湿度的相互作用对所有被检测的孵出幼体特征无叠加或减弱的显著影响.     

胚胎干细胞移植治疗糖尿病的研究进展

糖尿病是一种严重的免疫缺陷性疾病,目前的治疗方法很难从根本上治愈。近年来的研究表明,通过诱导胚胎干细胞定向分化为胰岛β细胞,并进行移植治疗糖尿病,是一种有希望的根治方案。本文就利用胚胎干细胞移植治疗糖尿病的最新进展作一综述。     

组蛋白去甲基化酶UTX与胚胎发育及疾病关系

组蛋白3赖氨酸27(histone 3 lysine 27, H3K27)去甲基化酶UTX(ubiquitously transcribed tetratricopeptide repeat on chromosome X, UTX)为X染色体上重复的转录三十四肽,是组蛋白3赖氨酸4(histone 3 lysine 4, H3K4)甲基转移酶复合物MLL2(mixed-lineage leukemia 2, MLL2)中的一员,可调节同源基因HOX(homeobox, HOX)和视网膜母细胞瘤基因RB(retinoblastoma, RB)转录谱系. UTX与BRG1-SWI/SNF重塑复合物(Brg1-containing ATPase-dependent Swi/Snf chromatin-remodeling complex, BRG1-SWI/SNF)相互作用促进染色质重塑. 因其在细胞的正确再编程、胚胎发育和组织特异性分化中扮演重要角色,UTX失活或缺失会导致癌症、胚胎发育缺陷等疾病的发生. 本文将对近年来UTX在胚胎发育及与疾病关系方面的研究进展做一综述.     

体外重组的人促黄体素对小鼠早期胚胎发育的影响

为了研究人的重组促黄体素（r-hLH)对小鼠早期胚胎发育的作用,我们用一定剂量的r-hFSH(人促卵泡素,20IU）结合不同剂量的r-hLH（0－20IU）,或先与不同剂量r-hLH配比（5－20IU）,再与一定剂量,r-hLH（15IU）结合,对性成熟前的小鼠进行超数排卵;并对从其输卵管冲出的早期胚胎进行体外培养,通过观察这些早期胚胎体外发育情况,再与PMSG－hCG超排小鼠的早期胚胎体外培养结果进行比较。我们发现用重组激素处理的性成熟前小鼠,无论在平均冲胚数或桑囊率,囊胚率上,都以结合r-hLH或配比r-hLH的剂量为15IU时最好,但各重组激素处理组在桑囊率和囊胚率上都极显著低于PMSG－hCG对照组的相应指标。上述结果表明,r-hLH对小鼠早期胚胎的发育（尤其是囊胚的形成）有明显的抑制作用,且与r-hLH呈一定的剂量依赖性关系。     

人胚胎干细胞建系的研究现状与存在的问题

人胚胎干细胞系的建立,对人类胚胎发生和人类发育生物学研究、人类新基因的发现和功能研究以及基因治疗、细胞和组织的移植治疗等领域的突破性进展具有重大意义;回顾了人胚胎干细胞建系研究的历程,就建系的几种方案、路线、意义和可行性进行了探讨;详细系统地说明了迄今为止建立人胚胎干细胞系所需要的饲养层类型、培养基组成、添加细胞因子种类及其作用;分析了建立和维持人胚胎干细胞系所需消化酶的种类及其作用以及目前常用的几种传代方法;从若干方面总结了人胚胎干细胞系的鉴定方法,并对建立和维持人胚胎干细胞系中存在的若干问题进行了剖析,提出了目前急待解决的问题。     

Spatial distribution and initial changes of SSEA-1 and other cell adhesion-related molecules on mouse embryonic stem cells before and during differentiation.

We examined the distribution of cell adhesion-related molecules (CAMs) among mouse embryonic stem (ES) cells and the spatial distribution on cell surfaces before and during differentiation. The cell-cell heterogeneity of SSEA-1, PECAM-1, and ICAM-1 among the undifferentiated cells in the ES cell colonies was evident by immunohistochemistry and immuno-SEM, supporting the flow cytometry findings. In contrast, most undifferentiated ES cells strongly expressed CD9. SSEA-1 was located preferentially on the edge of low protuberances and microvilli and formed clusters or linear arrays of 3-20 particles. PECAM-1 and ICAM-1 were randomly localized on the free cell surfaces, whereas CD9 was preferentially localized on the microvilli or protuberances, especially in the cell periphery. Both the SSEA-1(+) fraction and the SSEA-1(-) fraction of magnetic cell sorting (MACS) formed undifferentiated colonies after plating. Flow cytometry showed that these populations reverted separately again to a culture with a mixed phenotype. Differentiation induced by retinoic acid downregulated the expression of all CAMs. Immuno-SEM showed decreases of SSEA-1 in the differentiated ES cells, although some clustering still remained. Our findings help to elucidate the significance of these molecules in ES cell maintenance and differentiation and suggest that cell surface antigens may be useful for defining the phenotype of undifferentiated and differentiated ES cells.     

超声波辅助农杆菌介导CP基因转化番小瓜(Carioca papaya L.)的有效方法

本研究探索了通过农杆菌介导,超声波辅助处理,转化番木瓜胚性愈伤组织,获得转基因植株的有效方法。分别将含有日本PLDMV 外壳蛋白基因(PTi-Epj-TL-PLDMV)和含有台湾PRSV 菌株、美国夏威夷PRSV 菌株、泰国PRSV 菌株及日本PLDMV 菌株的多元外壳蛋白基因编码序列(PTi-NP-YKT)插入双元载体质粒pGA482G,借助于农杆菌系LBA4404将双元载体上的外壳蛋白基因和新霉素磷酸转移酶基因(nptⅡ)转移到番木瓜品种Sunset 的胚性愈伤组织中,从而获得抗卡那霉素的转化再生植株。试验着重在转化方法上进行探索。结果表明,农杆菌过夜培养后,用高渗透压培养液(1/2 MS 6%蔗糖 1%葡萄糖,pH 5.7)调整至光密度OD_(600(?)m)=0.15-0.20,然后用该菌液感染材料30min,其间辅以超声波处理,可以大大提高转化效率。用15ml 无菌离心管装载胚性愈伤材料进行15s 的超声波处理,在80块被转化的胚性愈伤中获得21个CP 基因G 转化系(26.3%),而在对照处理64块胚性愈伤中仅获得1个转化系(1.6%);在经过15s 的超声波处理48块被转化的胚性愈伤中获得8个CP 基因B 转化系(16.7%),而在对照处理25块胚性愈伤中未出现转化系。上述操作方法用在两种CP 基因转化上均表现出相似的效果。试验还表明:120mg/L 是卡那霉素抗性筛选的最佳浓度。抗性筛选9个月后,在421块胚性愈伤组织中产生了42个抗卡那霉素的转化系。所获得的转基因植株分别用PCR 和Southern 印迹杂交进行了鉴定。     

Differentiation Antigens: Dependence on Carcinogenesis Mechanisms and Tumor Progression (A Hypothesis)

The data considered in the paper indicate that a tumor clone resulting from cell transformation, in order to develop into an overt neoplasm, should overcome a microenvironmental constraint. This destroys intercellular contacts and cell interactions with extracellular matrix required for induction and maintenance of epithelium differentiation. The possible reasons for this lie in mutations of genes that control cell adhesion molecules and integrins, as well as proteases secreted by a tumor. These events lead to partial loss of differentiation antigens by a cell or to their incorrect localization in a cell. Simultaneously, the expression of embryo-specific genes is unblocked, leading to overexpression of embryonic antigens and their abnormal secretion into blood, which results in appearance of oncofetal serum markers. Discussed from this point of view are alpha-fetoprotein, the carcinoembryonic antigen, and the prostate-specific antigen, which are used as tumor markers.