牦牛和雄性不育犏牛睾丸PPP2CA、PME-1基因mRNA水平的比较

蛋白磷酸酶2A(PP2A)参与细胞中蛋白质的可逆磷酸化作用,在磷酸化信号通路调控方面具有重要功能,其活性受蛋白磷酸甲酯酶-1(PME-1)和其他因素的调控。为阐明牦牛杂交雄性不育的分子机制,本研究从牦牛睾丸中克隆了PP2A催化亚基α基因(PPP2CA)和PME-1基因c DNA序列,编码区长度分别为930 bp和1 143 bp,编码的氨基酸序列保守;定量PCR检测显示,犏牛(n=7)睾丸中PPP2CA与PME-1基因的m RNA水平均极显著低于牦牛(n=13,P0.01)。根据本研究结果,推测犏牛睾丸中这2个基因的显著下调可能会影响一些重要信号通路,且与犏牛雄性不育有关。     

黄牛、牦牛和犏牛睾丸组织中Boule基因片段进化分析

目的:揭示黄牛、牦牛和犏牛与其他物种的系统发育关系。方法:通过PCR扩增和克隆测序获得黄牛、牦牛和犏牛睾丸组织Boule基因片段序列,并运用生物信息学软件与NCBI已报道的其他17个物种Boule基因编码区片段序列比对分析。结果:黄牛、牦牛和犏牛睾丸组织Boule基因RT-PCR扩增特异性条带为154bp,与引物设计源序列进行同源性比较,发现同源性达99%,系统发育树显示,牛科中的牦牛、犏牛和黄牛交错聚在一起(BP=99%),然后与哺乳纲的其他物种相聚,而犏牛与爬行纲和鸟纲动物的亲缘关系较远。结论:Boule基因在动物体上同源性高,可应用于系统发生研究。     

黄牛、牦牛和犏牛睾丸组织中Cdc2、Cdc25A基因mRNA表达水平

黄牛和牦牛远缘杂交后代犏牛雄性不育是牦牛杂交改良中的一大难题。Cdc2和Cdc25A是减数分裂的两个关键基因, 其表达水平的下降将使精子发生不能正常进行, 导致雄性不育。为了探讨Cdc2、Cdc25A基因mRNA表达水平与犏牛雄性不育的关系, 文章采用荧光定量PCR技术对Cdc2和Cdc25A基因的组织表达特征以及在黄牛、牦牛和犏牛睾丸组织中的表达水平进行了分析。结果表明: Cdc2和Cdc25A基因在牦牛各种组织中广泛表达, 说明Cdc2和Cdc25A基因在各种组织细胞分裂和细胞周期运行中均发挥作用; 黄牛和牦牛睾丸组织中Cdc2、Cdc25A基因表达水平均显著高于犏牛(P<0.05), 说明睾丸组织中Cdc2和Cdc25A基因的低表达可能与犏牛雄性不育相关。     

P38和ERK1/2在肝细胞癌中的表达及意义

目的探讨p38（mitogen-activated protein kinase p38,p38）和细胞外信号调节激酶1/2（extracellular reg-ulated kinase 1/2,ERK1/2）在不同分化程度肝细胞癌（human hepatocellular carcinoma,HCC）中的表达情况,以及两者的相关性。方法通过免疫组化（Envision）法,检测52例肝癌组织及l0例癌旁正常肝脏组织中p38和ERK1/2的表达。结果：p38和ERK1/2在肝癌组织中均有表达,与正常组比较差异有显著性,且阳性率的高低与其分化程度有关,p38在肝癌组织中的表达随分化程度的增高阳性率降低（P〈0.05）;ERK1/2在中、低分化的肝癌组织分别与高分化相比差异具有显著性（P〈0.05）。但低分化与中分化的肝癌组织比较虽也有差异但无统计学意义（P〉0.05）。癌组织中p38和ERK1/2的表达呈中度正相关（r=0.703,P〈0.05）。结论HCC中,p38和ERK1/2表达和活性增加,且存在一定的相关性。     

Real-time PCR检测黄牛、牦牛、犏牛睾丸组织中Boule、Dazl基因mRNA表达

旨在探讨DAZ基因家族Dazl和Boule基因与犏牛雄性不育的关系.采用实时荧光定量PCR技术检测黄牛、牦牛和犏牛睾丸组织中DAZ基因家族Boule和Dazl基因mRNA表达并进行分析.结果表明,Boule和Dazl熔解曲线扩增产物呈现单特异峰,具有较高的灵敏度和特异性;标准曲线显示Ct值与重组质粒浓度间线性关系良好,相关系数均大于0.999;mRNA表达分析显示,3种牛中Dazl基因在犏牛睾丸组织中表达量最低,其中黄牛与牦牛、黄牛与犏牛差异显著(P＜0.05),犏牛与牦牛差异不显著(P＞0.05);Boule基因在3种牛睾丸组织中的表达量显示,黄牛与牦牛差异不显著(P＞0.05),黄牛、牦牛与犏牛差异显著(P＜0.05).结果提示,Dazl和Boule基因可作为研究犏牛雄性不育的候选基因.     

周围神经损伤中P2Y12受体-p38MAPK通路的研究进展

周围神经损伤是临床中常见的神经损伤之一,神经胶质细胞和信号通路转导在周围神经损伤和再生修复中发挥重要作用。小胶质细胞的活化与周围神经损伤导致的神经损伤及疼痛密切相关,小胶质细胞是周围神经损伤与修复的关键场所。脊髓背角的小胶质细胞可被嘌呤信号通路的P2Y_(12)受体活化,进而导致p38MAPK磷酸化,造成相关神经损伤及感觉功能障碍。以脊髓背角的小胶质细胞为靶点,从P2Y_(12)受体-p38MAPK通路的角度可揭示周围神经损伤的部分可能机制。探究从嘌呤信号通路与小胶质细胞活化的新角度,将神经损伤后的P2Y_(12)受体与p38MAPK的磷酸化表达联系为P2Y_(12)受体-p38MAPK通路,可为临床治疗周围神经损伤提供新的思路。本文就周围神经损伤中P2Y_(12)受体-p38MAPK通路的研究进展作一综述。     

WNK2通过抑制ERK1/2/ROS/SHP2信号通路延缓肝细胞癌的增殖和侵袭

目的 探讨WNK2对肝细胞癌(hepatocellocellua carcinoma, HCC)中ERK1/2/ROS/SHP2信号通路的影响,并探讨其在HCC细胞增殖和迁移中的作用。方法 将WNK2-mimic和sh-RNA WNK2以及相应的阴性对照转染HepG2细胞,采用BALB/c裸鼠皮下成瘤实验检测WNK2对肝细胞癌增殖能力的影响;采用Western Blot检测瘤组织中WNK2、p40、gp90、p-SHP2、p-AKT和p-ERK1/2的表达;使用SHP2抑制剂PHPS1进行处理之后,采用Western Blot检测HepG2细胞中WNK2、p40、gp90、p-SHP2、p-AKT和p-ERK1/2的表达;使用细胞划痕实验和Transwell检测HepG2细胞的迁移能力和侵袭能力;采用单克隆增殖实验和CCK-8检测HepG2细胞的增殖能力。结果 与sh-NC组相比,sh-RNA WNK2组裸鼠的瘤体体积显著增大(P<0.01);而与NC-mimic组相比,WNK2-mimic组裸鼠的瘤体体积显著减小(P<0.01);Western Blot结果显示,与sh-...     

荒漠甲虫小胸鳖甲胞外信号调节激酶ERK基因的克隆与低温表达谱分析

昆虫属变温生物,冷胁迫是其最常见的环境刺激。丝裂原活化蛋白激酶(MAPK)信号通路与细胞应对外界刺激密切相关,为了解MAPK信号通路在荒漠甲虫小胸鳖甲耐寒机制中的作用,从小胸鳖甲4℃转录组数据中筛选出胞外信号调节激酶(ERK)基因的全长c DNA,命名为Mp ERK。生物信息学分析表明,Mp ERK全长1125 bp,编码374个氨基酸。Mp ERK的理论分子量是43 k Da,含有ERK激酶所共有的磷酸化位点,属于MAPK超家族,与其它物种ERK的一致性达80%以上。实时定量PCR检测Mp ERK基因在低温下的表达谱发现,4℃处理1 h后,Mp ERK基因的表达上调为对照的7.5倍,5 h时达到高峰,为对照的15倍。-4℃处理1 h后,Mp ERK基因的表达上调为对照的8.4倍,5 h时达到高峰,为对照的13.75倍。研究结果表明Mp ERK基因是冷响应的,可能在小胸鳖甲应对低温时发挥信号转导作用。     

ERK1/2信号通路活化对Tamoxifen所致胶质瘤细胞凋亡的影响

为了探讨ERK1/2信号通路在他莫昔芬(tamoxifen, TAM)所致胶质瘤细胞凋亡中的作用,以C6和U87MG胶质瘤细胞为研究对象,经TAM处理后,采用MTT法检测细胞的存活率;倒置显微镜和DAPI染色观察细胞的形态;流式细胞术检测细胞凋亡; Western-blot法检测细胞内ERK1/2磷酸化水平。最后应用ERK1/2抑制剂(PD98059)与TAM共同作用,观察其对胶质瘤细胞内ERK1/2磷酸化水平和细胞凋亡的影响。实验结果显示:TAM可呈浓度和时间依赖性地抑制胶质瘤细胞生长; TAM处理组的细胞凋亡明显增加且呈浓度依赖性;TAM能增加细胞内ERK1/2磷酸化水平;以PD98059阻断ERK1/2的激活,能增强TAM诱导细胞凋亡的作用。实验结果表明TAM能够抑制胶质瘤细胞生长和促进其细胞凋亡, ERK1/2信号通路的激活参与调控TAM所致胶质瘤细胞凋亡。     

StARmRNA在仔猪睾丸组织中的表达研究

类固醇合成快速调节蛋白(steroidogenic acute regulatory protein,StAR )在调节类固醇合成中发挥了重要作用,为了认识StAR蛋白在仔猪性腺发育早期中的表达,本研究以7、14、23、37日龄的仔猪睾丸为研究对象,采用组织原位杂交方法研究了StAR mRNA在仔猪睾丸中的表达水平。结果表明：在7、14、23、37日龄的仔猪睾丸中,StARmRNA在睾丸的间质细胞中表达,其中在7日龄StARmRNA表达很弱,14、23、37日龄StARmRNA表达较强,StAR蛋白在这一时期的睾丸间质表达与其合成睾酮的能力一致。     

p-ERK1／2及ERK2mRNA在哮喘大鼠气道中的表达变化

目的探讨细胞外信号调节激酶在哮喘大鼠气道中表达变化及其对气道平滑肌细胞增殖的影响。观察细胞外信号调节激酶是否参与了哮喘气道重构这一病理过程。方法18只6周龄雄性wistar大鼠随机分为对照组、哮喘组、地塞米松干预组各6只。以腹腔注射10％卵蛋白和1％卵蛋白雾化吸入复制慢性哮喘模型。干预组在每次激发前给予地塞米松干预。用免疫组化与原位杂交法检测p-ERK1／2及ERK2mRNA在不同大鼠肺组织的表达程度,采用图像分析系统进行图象分析。结果（1）哮喘模型组气道壁面积和平滑肌厚度较对照组和干预组显著增加（P〈0．05）。（2）哮喘组p-ERK1／2及ERK2mRNA在大鼠肺组织的表达程度较对照组和干预组显著增加（P〈0．05）。（3）直线相关性分析显示,哮喘组气道壁面积和平滑肌厚度与大鼠肺组织中p-ERK1／2表达水平呈正相关（分别为r=0．858,r=0．848,P均〈0．05）,哮喘组气道壁面积和平滑肌厚度与大鼠肺组织中ERK2mRNA表达水平呈正相关,（分别为r=0．918,r=0．860,P均〈0．05）。结论哮喘大鼠肺组织p-ERK1／2及ERK2mRNA表达上调,并与气道重构密切相关,该结果提示细胞外信号调节激酶可能参与了气道重构中平滑肌的增殖过程。     

Resveratrol inhibits EMMPRIN expression via P38 and ERK1/2 pathways in PMA-induced THP-1 cells

The extracellular matrix metalloproteinase inducer (EMMPRIN) is significant in the regulation of matrix metalloproteinase (MMP) synthesis in atherosclerosis-related cells, and is possibly involved in the progression of atherosclerotic plaque. EMMPRIN expression is also up-regulated in PMA-induced THP-1 cells and is inhibited by resveratrol. However, it remains unclear how resveratrol inhibits EMMPRIN expression. We thus investigated the role of the MAPK signaling pathway in resveratrol inhibiting the up-regulation of EMMPRIN in PMA-induced THP-1 cells. We found that the ERK1/2 and p38 pathways, but not the JNK, are activated during the up-regulation of EMMPRIN expression. We also observed that while resveratrol suppresses the up-regulation of EMMPRIN, it also suppresses both the ERK1/2 and p38 pathways in a dose-dependent manner. Taken together, we established that it is through both the ERK1/2 and p38 MAPK pathways that resveratrol inhibits the expression of EMMPRIN in PMA-induced THP-1 cells.     

Regulation of Indian hedgehog mRNA levels in chondrocytic cells by ERK1/2 and p38 mitogen-activated protein kinases

Indian hedgehog (Ihh) is produced by growth plate pre-hypertrophic chondrocytes, and is an important regulator of endochondral ossification. However, little is known about the regulation of Ihh in chondrocytes. We have examined the role of integrins and mitogen-activated protein (MAP) kinases in Ihh mRNA regulation in CFK-2 chondrocytic cells. Cells incubated with the beta1-integrin blocking antibody had decreased Ihh mRNA levels, which was accompanied by decreases of activated extracellular signal-regulated kinases (ERK1/2) and activated p38 MAPK. Ihh mRNA levels were also inhibited by U0126, a specific MEK1/2 inhibitor, or SB203580, a specific p38 MAPK inhibitor. Cells transfected with constitutively active MEK1 or MKK3 had increased Ihh mRNA levels, which were diminished by dominant-negative MEK1, p38alpha or p38beta. Stimulation of the PTH1R with 10(-8) M rPTH (1-34) resulted in dephosphorylation of ERK1/2 that was evident within 15 min and sustained for 1 h, as well as transient dephosphorylation of p38 MAPK that was maximal after 25 min. PTH stimulation decreased Ihh mRNA levels, and this effect was blocked by transfecting the cells with constitutively active MEK1 but not by MKK3. These studies demonstrated that activation of ERK1/2 or p38 MAPK increased Ihh mRNA levels. Stimulation of the PTH1R or blocking of beta1-integrin resulted in inhibition of ERK1/2 and p38 MAPK and decreased levels of Ihh mRNA. Our data demonstrate the central role of MAPK in the regulation of Ihh in CFK-2 cells.     

LPS-Induced G-CSF Expression in Macrophages Is Mediated by ERK2, but Not ERK1

Granulocyte colony-stimulating factor (G-CSF) selectively stimulates proliferation and differentiation of neutrophil progenitors which play important roles in host defense against infectious agents. However, persistent G-CSF production often leads to neutrophilia and excessive inflammatory reactions. There is therefore a need to understand the mechanism regulating G-CSF expression. In this study, we showed that U0126, a MEK1/2 inhibitor, decreases lipopolysaccharide (LPS)-stimulated G-CSF promoter activity, mRNA expression and protein secretion. Using short hairpin RNA knockdown, we demonstrated that ERK2, and not ERK1, involves in LPS-induced G-CSF expression, but not LPS-regulated expression of TNF-α. Reporter assays showed that ERK2 and C/EBPβ synergistically activate G-CSF promoter activity. Further chromatin immunoprecipitation (ChIP) assays revealed that U0126 inhibits LPS-induced binding of NF-κB (p50/p65) and C/EBPβ to the G-CSF promoter, but not their nuclear protein levels. Knockdown of ERK2 inhibits LPS-induced accessibility of the G-CSF promoter region to DNase I, suggesting that chromatin remodeling may occur. These findings clarify that ERK2, rather than ERK1, mediates LPS-induced G-CSF expression in macrophages by remodeling chromatin, and stimulates C/EBPβ-dependent activation of the G-CSF promoter. This study provides a potential target for regulating G-CSF expression.     

拟南芥雄性不育相关基因LDAD1&2的遗传定位(英文)

利用EMS诱变筛选手段分离到一株拟南芥类似花药不开裂雄性不育突变体(like-defective in anther de-hiscence,ldad),其果荚干瘪,花药不能开裂且花粉败育。遗传分析表明,突变体的表型受2个隐性基因控制;细胞学观察发现,在花药发育过程中伴随着小孢子的降解;通过图位克隆初步对ldad的2个突变位点分别定位,一个定位在1号染色体上SSLP标记F22L4与端粒之间171 kb的区间,另一个定位在5号染色体上SSLP标记T10O8与端粒间150 kb的区间内;生物信息学分析显示此区间内未见育性相关的已知基因。该研究的结果对进一步克隆LDAD1&2基因及探讨其在花药发育中的功能具有重要意义。     

Age Dependence of the Level ofcopia Retrotransposon Expression in the Testes of Drosophila melanogaster

Expression of the lacZ reporter gene controlled by various deletion derivatives of the regulatory region of the copia retrotransposon was studied in the testes of adult transgenic males of the Drosophila melanogaster y ¹ w ^67c23(2) strain at the age of 3, 6–9, 12–15, 18–21, and 24–27 days. When the construct contained the full-length regulatory region, which included the 5-long terminal repeat (LTR) and the 5-untranslated region (UTR), expression was the lowest in males aged 12–15 days and the highest in males aged 3 or 24–27 days. A similar V-shaped age dependence was previously observed for the copia transposition rate and RNA content in a strain with a high rate of copia transposition. Thus, the V-shaped age dependence of expression, which is unusual for Drosophila, proved to be characteristic of copiaregardless of its transposition rate. Deletion of the 5 or 3 end of the LTR, but not of the UTR, changed the age dependence of the level of reporter gene expression. In this case, expression was the highest in 3-day-old males and gradually decreased with age, as typical for many Drosophila genes. It was assumed that the 5- and 3-terminal regions of the copiaLTR contain regulatory elements responsible for the V-shaped age dependence of expression, while the expression level depends to a greater extent on the regulatory elements of UTR.     

Src Tyrosine Kinase Activation by 4-Hydroxynonenal Upregulates p38, ERK/AP-1 Signaling and COX-2 Expression in YPEN-1 Cells

4-Hydroxynonenal (4-HNE), a major end product of lipid peroxidation, is highly reactive and involved in various cellular processes, such as inflammatory signaling. However, to date, the mechanistic roles of 4-HNE in inflammatory signaling related to protein tyrosine kinases have not been elucidated. In the present study, we investigated the interaction between 4-HNE and Src (a non-receptor tyrosine kinase) for its involvement in the molecular modulation of the inflammatory signaling pathway utilizing the YPEN-1 cell system. Immunoprecipitation experiments showed that 4-HNE phosphorylates (activates) Src at Tyr416 via adduct formation. In addition, LC-MS/MS and a docking simulation model revealed an addiction site at the Cys248 residue of Src, resulting in the stimulation of downstream p38, ERK/AP-1 and cyclooxygenase-2 (COX-2) signaling in YPEN-1 cells. The role of 4-HNE-activated Src in downstream inflammatory signaling was further investigated using dasatinib (a Src inhibitor) and by siRNA knockdown of Src. p38 and ERK were directly regulated by Src, as revealed by immunoblotting of the phosphorylated forms of mitogen-activated protein kinases (MAPKs), which are key elements in the signaling transduction pathway initiated by Src. The study also shows that Src modulates the HNE-enhanced activation of AP-1 and the expression of COX-2 (a target gene of AP-1). Together, the results of this study show that 4-HNE stimulates Src tyrosine kinase in activation of the inflammation process.