Sp1/Kruppel样转录因子家族研究进展

Spl/Kruppel样转录因子(Spl-like and Kruppel-like transcription factors,Spl/KLFs)是参与真核细胞转录的高度相关锌指蛋白,以细胞和启动子特异性方式通过调控富含GC启动子的基因表达,参与调节细胞功能如细胞增生、凋亡、分化和肿瘤形成.

盐皮质激素受体与内耳

生理条件下盐皮质激素(醛固酮)主要通过盐皮质激素受体(mineralocorticoid receptor,MR)发挥作用.MR属于类固醇/甲状腺/维生素A配体依赖的转录因子受体超家族(steroid/thyroid/retinoid receptor superfamilv of ligand-dependent transcription factors)的一员.体内除了肾脏、结肠、唾液腺这些经典的靶组织以外还存在多处MR作用的靶组织.本文拟综述MR的结构特点、作用方式及其与内耳组织的关系.

转录因子参与药物成瘾的分子学机制

药物成瘾是以失去控制力、强迫性连续用药为主的慢性复发性脑病[1].强迫性索药、对药物的渴求和复吸构成了药物成瘾的三大特征,而且一旦形成,将持续数月甚至数年,因此有学者认为[2]成瘾状态是药物诱导的神经可塑性改变的形式之一.近年来的研究也认为[3],药物成瘾的持续状态在于成瘾性药物诱导了长期的神经适应性变化,尤其是转录过程的改变以及转录因子参与的基因表达在其中发挥了重要的作用.环磷酸腺苷(cAMP)反应元件结合蛋白(CREB)及△FosB是成瘾性药物应用后发生改变的主要的转录调节因子.本文综述了CREB及△FosB参与药物成瘾机制的研究进展.

梅毒血清固定患者外周血调节性T细胞/Th17细胞平衡的研究

目的 探讨梅毒血清固定患者外周血调节性T细胞(Treg细胞)和Th17细胞平衡的变化.方法 梅毒血清固定患者26例,正常人对照23例,利用流式细胞仪分别检测外周血Treg细胞和Th17细胞的比例及相关特异性转录因子Foxp3和ROR-γt的定量表达情况,并进行相关性分析.结果 梅毒血清固定患者外周血CD4+T细胞中,Treg细胞比例为33.28％±11.84％,明显高于正常人对照组(22.13％±7.79％,P＜0.01)；Th17细胞比例(3.17％±2.32％)显著低于正常人对照组(8.87％±2.00％,P＜ 0.01)；CD4+T细胞内转录因子Foxp3的表达量(2994.86±1099.18)高于正常人对照组(2539.72±1086.96,P＜0.05),而ROR-γt的表达量(1473.12±752.20)低于正常人对照组(1778.34±388.13,P＜ 0.05).在所有受试者外周血CD4+T细胞中Foxp3和ROR-γt的表达呈负相关(r=-0.48,P＜0.01).结论 梅毒血清固定患者外周血存在Treg/Th 17细胞平衡的异常.

植物雌激素α-玉米赤霉醇降低组织因子及核转录因子AP-1和NF-κB水平的作用

雌激素在体内具有广泛的生物学活性.妇女进入绝经期后,随着体内雌激素水平显著下降,出现与之相关的绝经期综合症,同时心血管疾病如冠心病、动脉粥样硬化等的发生率明显升高[1].

K离子通道在剪切力诱导血管内皮细胞信号转导中的作用

血液在血管中流动时对血管壁产生持续的作力,分为剪切力、周向应力和压应力[1],剪切力在心血管系统的许多病理及病理生理过程中起着重要而跃的作用[2],它可以影响血管内皮细胞的形态及功能,导致应激的和缓慢的组织应答.剪切力信号通过血管内皮细胞的转导主要通过细胞骨架与生化因的相互作用,并引起内皮细胞结构、代谢及基因表达的变化[3,4].但长期以来,剪切力诱导内皮细胞形态学和功能的改变未能受到足够的重视,本综述描述了剪切力信号转导的可能途径,重点是离子通道(特别是K+通道)对剪切力的应答以及由此引起的细胞反应.

AIM:R-spondin 2 (Rspo2), one member of R-spondin family which contains four secreted proteins , plays an important role in skeletal muscle development .However, the impact of Rspo2 on vascular smooth muscle cell ( SMC) differentiation is little known . This study aims at revealing the role and mechanism of Rspo 2 on SMC differentiation from embryonic stem cells (ESCs).METHODS:A well-established model for studying SMC differentiation from ESCs were used , in which mouse embryonic stem cells ( ES-D3) were seeded on collagen IV-coated flasks and cultured in differentiation medium (DM) for 2, 4, 6 and 8 days.Smooth muscle specific markers, includingα-smooth muscle actin (α-SMA), SM22 and smooth muscle myosin heavy chain (SM-MHC), were detected to in-sure the successful model by qRT-PCR and Western blot .After 3-day pre-differentiation, ESCs were treated with recombinant Rspo 2 protein, overexpression plasmid or shRNA plasmid for 96 h, and the mRNA and protein expression of smooth muscle markers was detected.To explore the role of Rspo2 on SMC differentiation in vivo, 3-day predifferentiated ESCs (106 in 50μLα-MEM) incubated with Rspo2-overexpression plasmid were mixed with 50 μL of Matrigel ( Becton Dickinson Labware ) and then subcutaneously injected into C57BL/6J mice.After 12 days, mice were sacrificed and the implants were harvested for immunofluorescence staining , qRT-PCR and Western blot.Furthermore, electrophoretic mobility shift assay (EMSA), chromatin immunoprecipitation assay (ChIP) and lucif-erase reporter assay were performed to investigate the transcriptional activity of SMC differentiation related transcription factors , inclu-ding serum response factor (SRF), myocardin (MYO), myocyte-specific enhancer factor 2C (MEF-2C).Involvement of Rspo2 re-ceptor, leucine-rich repeat-containing, G-protein-coupled receptors (Lgr)4,5,6, and β-catenin pathway during Rspo2-induced MSC differentiation were also uncovered by overexpression or inhibition of the respective protein .RESULTS:Our results showed that Rspo 2 mRNA and protein expression was significantly and consistently increased during ESC differentiation towards SMCs .Recombinant Rs-po2 protein and enforced Rspo 2 expression in ESCs resulted in up-regulation of smooth muscle markers and transcription factors , while knockdown decreased the expression of these genes .Expectedly , Rspo2 overexpression also promotes SMC differentiation in vivo.
Mechanistically , our data showed that Rspo 2 could promote SRF binding to SM22 promoter region .Evidence also revealed that one of three Rspo2 receptors, LGR5, was up-regulated while the other two , LGR4 and LGR6, was down-regulated.Silencing of LGR5 inhibi-ted Rspo2-induced SMC differentiation, whereas knockdown of LGR4 had no impact.Finally, activation or inhibition of β-catenin could promote or inhibit SMC differentiation , respectively .CONCLUSION: Our findings demonstrate for the first time that Rspo 2 plays a positive role during smooth muscle cell differentiation from embryonic stem cells .We confirmed that Rspo 2 can up-regulate smooth muscle markers at transcription level .We also revealed Rspo promote smooth muscle cell differentiation through activation of LGR 5 re-ceptor and Wnt/β-catenin pathway .

于福興實驗室研究計劃

1 Molecular regulation of corneal wound healing Rapid healing of the corneal epithelium in response to injury is essential for maintenance of its barrier function. The long-term goal of this project is to obtain basic information about the molecular and cell biology of corneal wound healing. The project will test the hypotheses that amyloid β/A4 precursor-like protein controls serine proteinase activity, mediates cell adhesion, and promotes cell migration during corneal reepithelialization. This study should provide the basis to begin constructing a detailed nap of the molecular pathways and interconnecting networks of proteins functioning in wound repair and to develop therapeutics for treatment of corneal diseases like recurrent erosions and persistent defects of the epithelium.2 Developing an ex vivo model for ocular irritation testThe objective of this project is to develop an ex vivo assay system to predict ocular irritation potential of test chemicals and consumer products. Our hypothesis has been that activation of these transcription factors and disruption of corneal integrity can be used as endpoints/ markers for evaluating ocular toxicity in organ culture. Our goal is to develop a sensitive, efficient, economical and reliable ex vivo model for predicting irritation potential of a chemical or consumer product with mechanistic basis.3 Modulation of epithelial barrier function during corneal infectionThe long-term goal of this project is to understand the mechanisms underlying the induction of the inflammatory reaction and breakdown of the epithelial barrier in the cornea upon infection. We will test the hypothesis that in the cornea TLRs confer responsiveness of HCE cells to pathogens, and PA challenge-induced TLR signaling, through activation of NF-?B and/ or mitogen-activated protein kinase (MAPK), contributes to infection-induced epithelial barrier breakdown. The following studies will be carried out. An understanding of how TLRs transmit signals that lead to epithelial response, including modulation of barrier function,may allow the development of therapeutic agents that prevent breakdown or enhance recovery of barrier function during infection and, as an adjuvant therapy, eliminate the corneal scarring and vision loss associated with bacterial keratitis.4 Developing an adjuvant therapy to reduce inflammatory response induced by bacterial infection of the cornea (bacterial keratitis).