During development and in the context of different morphogenetic events, epithelial cells undergo a process called epithelial to mesenchymal transition or transdifferentiation （EMT）. In this process, the cells lose ...During development and in the context of different morphogenetic events, epithelial cells undergo a process called epithelial to mesenchymal transition or transdifferentiation （EMT）. In this process, the cells lose their epithelial characteristics, including their polarity and specialized cell-cell contacts, and acquire a migratory behavior, allowing them to move away from their epithelial cell community and to integrate into surrounding tissue, even at remote locations. EMT illustrates the differentiation plasticity during development and is complemented by another process, called mesenchymal to epithelial transition （MET）. While being an integral process during development, EMT is also recapitulated under pathological conditions, prominently in fibrosis and in invasion and metastasis of carcinomas. Accordingly, EMT is considered as an important step in tumor progression. TGF-β signaling has been shown to play an important role in EMT. In fact, adding TGF-β to epithelial cells in culture is a convenient way to induce EMT in various epithelial cells. Although much less characterized, epithelial plasticity can also be regulated by TGF-β-related bone morphogenetic proteins （BMPs）, and BMPs have been shown to induce EMT or MET depending on the developmental context. In this review, we will discuss the induction of EMT in response to TGF-β, and focus on the under- lying signaling and transcription mechanisms.展开更多
Transforming growth factor-beta （TGF-β）/bone morphogenic protein （BMP） signaling is involved in the vast majority of cellular processes and is fundamentally important during the entire life of all metazoans. Dere...Transforming growth factor-beta （TGF-β）/bone morphogenic protein （BMP） signaling is involved in the vast majority of cellular processes and is fundamentally important during the entire life of all metazoans. Deregulation of TGF-β/ BMP activity almost invariably leads to developmental defects and/or diseases, including cancer. The proper functioning of the TGF-β/BMP pathway depends on its constitutive and extensive communication with other signaling pathways, leading to synergistic or antagonistic effects and eventually desirable biological outcomes. The nature of such signaling cross-talk is overwhelmingly complex and highly context-dependent. Here we review the different modes of cross-talk between TGF-β/BMP and the signaling pathways of Mitogen-activated protein kinase, phosphatidylinositol-3 kinase/ Akt, Wnt, Hedgehog, Notch, and the interleukin/interferon-gamma/tumor necrosis factor-alpha cytokines, with an emphasis on the underlying molecular mechanisms.展开更多
Transforming growth factor-β utilizes a multitude of intracellular signaling pathways in addition to Smads to regulate a wide array of cellular functions. These non-canonical, non-Smad pathways are activated directly...Transforming growth factor-β utilizes a multitude of intracellular signaling pathways in addition to Smads to regulate a wide array of cellular functions. These non-canonical, non-Smad pathways are activated directly by ligandoccupied receptors to reinforce, attenuate, or otherwise modulate downstream cellular responses. These non-Smad pathways include various branches of MAP kinase pathways, Rho-like GTPase signaling pathways, and phosphatidylinositol-3-kinase/AKT pathways. This review focuses on recent advances in the understanding of the molecular and biochemical mechanisms of non-Smad pathways. In addition, functions of these non-Smad pathways are also discussed.展开更多
The TGFβ signaling pathway is conserved from flies to humans and has been shown to regulate such diverse pro- cesses as cell proliferation, differentiation, motility, adhesion, organization, and programmed cell death...The TGFβ signaling pathway is conserved from flies to humans and has been shown to regulate such diverse pro- cesses as cell proliferation, differentiation, motility, adhesion, organization, and programmed cell death. Both in vitro and in vivo experiments suggest that TGF[~ can utilize these varied programs to promote cancer metastasis through its effects on the tumor microenvironment, enhanced invasive properties, and inhibition of immune cell function. Recent clinical evidence demonstrating a link between TGFβ signaling and cancer progression is fostering interest in this signaling pathway as a therapeutic target. Anti-TGFβ therapies are currently being developed and tested in pre- clinical studies. However, targeting TGFβ carries a substantial risk as this pathway is implicated in multiple homeostatic processes and is also known to have tumor-suppressor functions. Additionally, clinical and experimental results show that TGFβ has diverse and often conflicting roles in tumor progression even within the same tumor types. The development of TGFβ inhibitors for clinical use will require a deeper understanding of TGFβ signaling, its consequences, and the contexts in which it acts.展开更多
Transforming growth factor （TGF）-βs and their family members, including bone morphogenetic proteins （BMPs）, Nodal and activins, have been implicated in the development and maintenance of various organs, in which ...Transforming growth factor （TGF）-βs and their family members, including bone morphogenetic proteins （BMPs）, Nodal and activins, have been implicated in the development and maintenance of various organs, in which stem cells play important roles. Stem cells are characterized by their ability to self-renew and to generate differentiated cells of a particular tissue, and are classified into embryonic and somatic stem cells. Embryonic stem （ES） cells self-renew indefinitely and contribute to derivatives of all three primary germ layers. In contrast, somatic stem cells, which can be identified in various adult organs, exhibit limited abilities for self-renewal and differentiation in most cases. The multi-lineage differentiation capacity of ES ceils and somatic stem cells has opened possibilities for cell replacement therapies for genetic, malignant and degenerative diseases. In order to utilize stem cells for therapeutic applications, it is essential to understand the extrinsic and intrinsic factors regulating self-renewal and differentiation of stem cells. More recently, induced pluripotent stem （iPS） cells have been generated from mouse and human fibroblasts that resemble ES cells via ectopic expression of four transcription factors, iPS cells may have an advantage in regenerative medicine, since they overcome the immunogenicity and ethical controversy of ES cells. Moreover, recent studies have highlighted the involvement of cancer stem cells during the formation and progression of various types of cancers, including leukemia, glioma, and breast cancer. Here, we illustrate the roles of TGF-β family members in the maintenance and differentiation of ES cells, somatic stem cells, and cancer stem cells.展开更多
类风湿性关节炎(rheumatoid arthritis,RA)是一种以慢性多关节滑膜炎为主要特征的自身免疫性疾病。虽然目前对于RA的确切发病机制尚不明确,但一般认为和T细胞相关。最近研究发现调节性T细胞(regulatory T cell,Treg)和Th17细胞在RA的发...类风湿性关节炎(rheumatoid arthritis,RA)是一种以慢性多关节滑膜炎为主要特征的自身免疫性疾病。虽然目前对于RA的确切发病机制尚不明确,但一般认为和T细胞相关。最近研究发现调节性T细胞(regulatory T cell,Treg)和Th17细胞在RA的发生发展中发挥重要作用。Th17细胞能够分泌促炎症因子IL-17,通过诱导基质金属蛋白酶(ma-trix metallo proteinases,MMPs)和破骨细胞生成,促进骨滑膜炎症、骨和关节损伤;而Treg则通过释放抑制性细胞因子IL-10和TGF-β发挥免疫效应,调控RA中的炎症性免疫应答过程。单独TGF-β作用下诱导初始T细胞分化为Treg,而在TGF-β和IL-6共同作用下诱导初始T细胞分化为Th17细胞,因此,Th17和Treg细胞在特定的细胞因子微环境下可以相互转化。调节Th17/Treg之间的平衡可能成为治疗RA的新方法。该文将对Th17/Treg平衡在RA发生发展中的调节作用作一综述。展开更多
Ski and the closely related SnoN were discovered as oncogenes by their ability to transform chicken embryo fibroblasts upon overexpression. While elevated expressions of Ski and SnoN have also been reported in many hu...Ski and the closely related SnoN were discovered as oncogenes by their ability to transform chicken embryo fibroblasts upon overexpression. While elevated expressions of Ski and SnoN have also been reported in many human cancer cells and tissues, consistent with their pro-oncogenic activity, emerging evidence also suggests a potential anti-oncogenic activity for both. In addition, Ski and SnoN have been implicated in regulation of cell differentiation, especially in the muscle and neuronal lineages. Multiple cellular partners of Ski and SnoN have been identifed in an effort to understand the molecular mechanisms underlying the complex roles of Ski and SnoN. In this review, we summarize recent findings on the biological functions of Ski and SnoN, their mechanisms of action and how their levels of expression are regulated.展开更多
目的探讨乙肝病毒(hepatitis B virus,HBV)感染患者外周血中几种细胞因子在疾病慢性化及疾病进展中的作用。方法分离HBV慢性感染者及健康人外周血,采用酶联免疫吸附法(ELISA法)检测IL-17、IL-23、TGF-β和IL-10的表达及其与乙肝患者肝...目的探讨乙肝病毒(hepatitis B virus,HBV)感染患者外周血中几种细胞因子在疾病慢性化及疾病进展中的作用。方法分离HBV慢性感染者及健康人外周血,采用酶联免疫吸附法(ELISA法)检测IL-17、IL-23、TGF-β和IL-10的表达及其与乙肝患者肝功能指标及血清中病毒载量的关系。结果乙肝患者血清中IL-17、IL-23和TGF-β与健康对照比较无明显差异,但IL-10显著增加,IL-17、IL-10与转氨酶水平正相关,TGF-β与转氨酶水平负相关,而IL-10与乙肝病毒DNA载量正相关。结论IL-17、IL-10及TGF-β与HBV感染者肝细胞的炎性损伤有关,对于乙肝患者肝纤维化及疾病进展程度具有提示意义,而IL-10具有促炎和耐受的双重作用,可以预测乙肝感染慢性化及病毒持续感染。展开更多
文摘During development and in the context of different morphogenetic events, epithelial cells undergo a process called epithelial to mesenchymal transition or transdifferentiation （EMT）. In this process, the cells lose their epithelial characteristics, including their polarity and specialized cell-cell contacts, and acquire a migratory behavior, allowing them to move away from their epithelial cell community and to integrate into surrounding tissue, even at remote locations. EMT illustrates the differentiation plasticity during development and is complemented by another process, called mesenchymal to epithelial transition （MET）. While being an integral process during development, EMT is also recapitulated under pathological conditions, prominently in fibrosis and in invasion and metastasis of carcinomas. Accordingly, EMT is considered as an important step in tumor progression. TGF-β signaling has been shown to play an important role in EMT. In fact, adding TGF-β to epithelial cells in culture is a convenient way to induce EMT in various epithelial cells. Although much less characterized, epithelial plasticity can also be regulated by TGF-β-related bone morphogenetic proteins （BMPs）, and BMPs have been shown to induce EMT or MET depending on the developmental context. In this review, we will discuss the induction of EMT in response to TGF-β, and focus on the under- lying signaling and transcription mechanisms.
文摘Transforming growth factor-beta （TGF-β）/bone morphogenic protein （BMP） signaling is involved in the vast majority of cellular processes and is fundamentally important during the entire life of all metazoans. Deregulation of TGF-β/ BMP activity almost invariably leads to developmental defects and/or diseases, including cancer. The proper functioning of the TGF-β/BMP pathway depends on its constitutive and extensive communication with other signaling pathways, leading to synergistic or antagonistic effects and eventually desirable biological outcomes. The nature of such signaling cross-talk is overwhelmingly complex and highly context-dependent. Here we review the different modes of cross-talk between TGF-β/BMP and the signaling pathways of Mitogen-activated protein kinase, phosphatidylinositol-3 kinase/ Akt, Wnt, Hedgehog, Notch, and the interleukin/interferon-gamma/tumor necrosis factor-alpha cytokines, with an emphasis on the underlying molecular mechanisms.
文摘Transforming growth factor-β utilizes a multitude of intracellular signaling pathways in addition to Smads to regulate a wide array of cellular functions. These non-canonical, non-Smad pathways are activated directly by ligandoccupied receptors to reinforce, attenuate, or otherwise modulate downstream cellular responses. These non-Smad pathways include various branches of MAP kinase pathways, Rho-like GTPase signaling pathways, and phosphatidylinositol-3-kinase/AKT pathways. This review focuses on recent advances in the understanding of the molecular and biochemical mechanisms of non-Smad pathways. In addition, functions of these non-Smad pathways are also discussed.
文摘The TGFβ signaling pathway is conserved from flies to humans and has been shown to regulate such diverse pro- cesses as cell proliferation, differentiation, motility, adhesion, organization, and programmed cell death. Both in vitro and in vivo experiments suggest that TGF[~ can utilize these varied programs to promote cancer metastasis through its effects on the tumor microenvironment, enhanced invasive properties, and inhibition of immune cell function. Recent clinical evidence demonstrating a link between TGFβ signaling and cancer progression is fostering interest in this signaling pathway as a therapeutic target. Anti-TGFβ therapies are currently being developed and tested in pre- clinical studies. However, targeting TGFβ carries a substantial risk as this pathway is implicated in multiple homeostatic processes and is also known to have tumor-suppressor functions. Additionally, clinical and experimental results show that TGFβ has diverse and often conflicting roles in tumor progression even within the same tumor types. The development of TGFβ inhibitors for clinical use will require a deeper understanding of TGFβ signaling, its consequences, and the contexts in which it acts.
文摘Transforming growth factor （TGF）-βs and their family members, including bone morphogenetic proteins （BMPs）, Nodal and activins, have been implicated in the development and maintenance of various organs, in which stem cells play important roles. Stem cells are characterized by their ability to self-renew and to generate differentiated cells of a particular tissue, and are classified into embryonic and somatic stem cells. Embryonic stem （ES） cells self-renew indefinitely and contribute to derivatives of all three primary germ layers. In contrast, somatic stem cells, which can be identified in various adult organs, exhibit limited abilities for self-renewal and differentiation in most cases. The multi-lineage differentiation capacity of ES ceils and somatic stem cells has opened possibilities for cell replacement therapies for genetic, malignant and degenerative diseases. In order to utilize stem cells for therapeutic applications, it is essential to understand the extrinsic and intrinsic factors regulating self-renewal and differentiation of stem cells. More recently, induced pluripotent stem （iPS） cells have been generated from mouse and human fibroblasts that resemble ES cells via ectopic expression of four transcription factors, iPS cells may have an advantage in regenerative medicine, since they overcome the immunogenicity and ethical controversy of ES cells. Moreover, recent studies have highlighted the involvement of cancer stem cells during the formation and progression of various types of cancers, including leukemia, glioma, and breast cancer. Here, we illustrate the roles of TGF-β family members in the maintenance and differentiation of ES cells, somatic stem cells, and cancer stem cells.
文摘Ski and the closely related SnoN were discovered as oncogenes by their ability to transform chicken embryo fibroblasts upon overexpression. While elevated expressions of Ski and SnoN have also been reported in many human cancer cells and tissues, consistent with their pro-oncogenic activity, emerging evidence also suggests a potential anti-oncogenic activity for both. In addition, Ski and SnoN have been implicated in regulation of cell differentiation, especially in the muscle and neuronal lineages. Multiple cellular partners of Ski and SnoN have been identifed in an effort to understand the molecular mechanisms underlying the complex roles of Ski and SnoN. In this review, we summarize recent findings on the biological functions of Ski and SnoN, their mechanisms of action and how their levels of expression are regulated.
文摘目的探讨乙肝病毒(hepatitis B virus,HBV)感染患者外周血中几种细胞因子在疾病慢性化及疾病进展中的作用。方法分离HBV慢性感染者及健康人外周血,采用酶联免疫吸附法(ELISA法)检测IL-17、IL-23、TGF-β和IL-10的表达及其与乙肝患者肝功能指标及血清中病毒载量的关系。结果乙肝患者血清中IL-17、IL-23和TGF-β与健康对照比较无明显差异,但IL-10显著增加,IL-17、IL-10与转氨酶水平正相关,TGF-β与转氨酶水平负相关,而IL-10与乙肝病毒DNA载量正相关。结论IL-17、IL-10及TGF-β与HBV感染者肝细胞的炎性损伤有关,对于乙肝患者肝纤维化及疾病进展程度具有提示意义,而IL-10具有促炎和耐受的双重作用,可以预测乙肝感染慢性化及病毒持续感染。
