膜蛋白尼曼-匹克C1型类似蛋白1(Niemann-Pick C1 Like 1,NPC1L1)是介导肝脏和小肠细胞从胆汁或食物中吸收胆固醇的关键蛋白质。本文综述了NPC1L1蛋白的结构、功能及其介导肝肠细胞吸收外源胆固醇的分子机制。NPC1L1蛋白与脂筏蛋白Flotil...膜蛋白尼曼-匹克C1型类似蛋白1(Niemann-Pick C1 Like 1,NPC1L1)是介导肝脏和小肠细胞从胆汁或食物中吸收胆固醇的关键蛋白质。本文综述了NPC1L1蛋白的结构、功能及其介导肝肠细胞吸收外源胆固醇的分子机制。NPC1L1蛋白与脂筏蛋白Flotillin-1或Flotillin-2结合,在细胞质膜上形成富含胆固醇的膜微结构域,通过clathrin/AP2介导的囊泡内吞机制,将该NPC1L1-Flotillin-Cholesterol膜微结构域内吞运输至细胞内的内吞循环体上;内吞循环体上的胆固醇浓度下降后,NPC1L1-Flotillin复合物则由Cdc42和Myosin Vb.Rab11a.Rab11-FIP2蛋白运输至质膜,以执行下一轮的胆固醇吸收功能。NPC1L1蛋白的N端结构域可特异性结合胆固醇,是NPC1L1-Flotillin-Cholesterol膜微结构域形成所必需的,同时决定了胆固醇吸收的特异性。人群中NPC1L1基因的多态性与胆固醇吸收异常相关。本文还对未来的研究方向进行了探讨。展开更多
The identification and use of molecular biomarkers have greatly improved the diagnosis and treatment of malignant tumors. However, a much deeper understanding of oncogenic proteins is needed for the benefit to cancer ...The identification and use of molecular biomarkers have greatly improved the diagnosis and treatment of malignant tumors. However, a much deeper understanding of oncogenic proteins is needed for the benefit to cancer patients. The lipid raft marker proteins, flotillin-1 and flotillin-2, were first found in goldfish retinal ganglion cells during axon regeneration. They have since been found in a variety of cells, mainly on the inner surface of cell membranes, and not only act as a skeleton to provide a platform for protein-protein interactions, but also are involved in signal transduction, nerve regeneration, endocytosis, and lymphocyte activation. Previous studies have shown that flotillins are closely associated with tumor development, invasion, and metastasis. In this article, we review the functions of flotillins in relevant cell processes, their underlying mechanisms of action in a variety of tumors, and their potential applications to tumor molecular diagnosis and targeted therapy.展开更多
Objective:Small cell lung carcinoma(SCLC)is considered one of the most aggressive types of lung cancer due to its rapid growth and early metastasis.No tumor markers or therapeutic targets have been demonstrated to be ...Objective:Small cell lung carcinoma(SCLC)is considered one of the most aggressive types of lung cancer due to its rapid growth and early metastasis.No tumor markers or therapeutic targets have been demonstrated to be specific or effective in SCLC to date.This study aims to evaluate the potential of Flotillin1(Flot1)as a target of SCLC treatment.Methods:Flot1 expression level in the tissue of SCLC and other tissue of lung disease was detected using immunohistochemical staining.Transwell and Matrigel assays were employed to examine migration and invasion of cancer cells.Flow cytometry and xCELLigence system were used to evaluate cell apoptosis and cell viability,respectively.Expression levels of Flot1,epithelialmesenchymal transition(EMT)marker E-cadherin,vimentin,cyclinD1,TGF-β-Smad2/3,and p-AKT were examined using Western blot.Furthermore,xenograft tumor in nude mice was used to evaluate the growth and metastasis of NCI-H446 cells in vivo.Results:Our results demonstrated that Flot1 is highly expressed in SCLC samples and that its expression correlates strongly with clinical stage,distant metastasis,and poor survival.The knockdown of Flot1 decreased the growth,migration,and invasiveness of SCLC cells and reversed EMT phenotype in vitro and in vivo,while enhanced Flot1 expression exhibited the opposite behavior.Gene expression profile analysis demonstrated that Flot1-regulated genes frequently mapped to the AKT and TGF-β-Smad2/3pathways.Our results further revealed that Flot1 affected the progression of SCLC via regulation of EMT progression.Conclusions:These findings indicated an oncogenic role of Flot1 via promoting EMT in SCLC and suggested its potential as a tumor marker and prognostic indicator.展开更多
Spermatogenesis is a complex process of terminal differentiation by which mature sperms are generated,and it can be divided into three phases：mitosis,meiosis and spermiogenesis.In a previous study,we established a se...Spermatogenesis is a complex process of terminal differentiation by which mature sperms are generated,and it can be divided into three phases：mitosis,meiosis and spermiogenesis.In a previous study,we established a series of proteomic profiles for spermatogenesis to understand the regulation of male fertility and infertility.Here,we further investigated the localization and the role of flotillin-2 in spermiogenesis.Flotillin-2 expression was investigated in the testis of male CD1 mice at various developmental stages of spermatogenesis by using Western blotting,immunohistochemistry and immunofluorescence.Flotillin-2 was knocked down in vivo in three-week-old male mice using intratesticular injection of small inhibitory RNA（siRNA）,and sperm abnormalities were assessed three weeks later.Flotillin-2 was expressed at high levels in male germ cells during spermatogenesis.Flotillin-2 immunoreactivity was observed in pachytene spermatocytes as a strong dot-shaped signal and in round spermatids as a sickle-shaped distribution ahead of the acrosome.Immunofluorescence confirmed flotillin-2 was localized in front of the acrosome in round spermatids,indicating that flotillin-2 was localized to the Golgi apparatus.Knockdown of flotillin-2 in vivo led to a significant increase in head sperm abnormalities isolated from the cauda epididymis,compared with control siRNA-injected testes.This study indicates that flotillin-2 is a novel Golgi-related protein involved in sperm acrosome biogenesis.展开更多
文摘膜蛋白尼曼-匹克C1型类似蛋白1(Niemann-Pick C1 Like 1,NPC1L1)是介导肝脏和小肠细胞从胆汁或食物中吸收胆固醇的关键蛋白质。本文综述了NPC1L1蛋白的结构、功能及其介导肝肠细胞吸收外源胆固醇的分子机制。NPC1L1蛋白与脂筏蛋白Flotillin-1或Flotillin-2结合,在细胞质膜上形成富含胆固醇的膜微结构域,通过clathrin/AP2介导的囊泡内吞机制,将该NPC1L1-Flotillin-Cholesterol膜微结构域内吞运输至细胞内的内吞循环体上;内吞循环体上的胆固醇浓度下降后,NPC1L1-Flotillin复合物则由Cdc42和Myosin Vb.Rab11a.Rab11-FIP2蛋白运输至质膜,以执行下一轮的胆固醇吸收功能。NPC1L1蛋白的N端结构域可特异性结合胆固醇,是NPC1L1-Flotillin-Cholesterol膜微结构域形成所必需的,同时决定了胆固醇吸收的特异性。人群中NPC1L1基因的多态性与胆固醇吸收异常相关。本文还对未来的研究方向进行了探讨。
基金Project supported by the National Natural Science Foundation of China(Nos.81773179 and 81272972)the National Basic Research Program(973)of China(No.2010CB833605)+3 种基金the Hunan Provincial Science and Technology Department(Nos.2013FJ4010 and2014FJ6006)the Open-End Fund for the Valuable and Precision Instruments of Central South University(Nos.CSUZC201634 and CSUZC201638)the Natural Science Foundation of Hunan Province(No.2016JJ2172)the National College Students Innovation Projects(Nos.201610533264 and 201610533538),China
文摘The identification and use of molecular biomarkers have greatly improved the diagnosis and treatment of malignant tumors. However, a much deeper understanding of oncogenic proteins is needed for the benefit to cancer patients. The lipid raft marker proteins, flotillin-1 and flotillin-2, were first found in goldfish retinal ganglion cells during axon regeneration. They have since been found in a variety of cells, mainly on the inner surface of cell membranes, and not only act as a skeleton to provide a platform for protein-protein interactions, but also are involved in signal transduction, nerve regeneration, endocytosis, and lymphocyte activation. Previous studies have shown that flotillins are closely associated with tumor development, invasion, and metastasis. In this article, we review the functions of flotillins in relevant cell processes, their underlying mechanisms of action in a variety of tumors, and their potential applications to tumor molecular diagnosis and targeted therapy.
基金the National Natural Science Foundation of China (Grant No. 81472661, 81490753, 81230047, 81672743, 81772550) Postdoctoral Science Foundation Program of Chinese Academy of Medical Science & Peking Medical College
文摘Objective:Small cell lung carcinoma(SCLC)is considered one of the most aggressive types of lung cancer due to its rapid growth and early metastasis.No tumor markers or therapeutic targets have been demonstrated to be specific or effective in SCLC to date.This study aims to evaluate the potential of Flotillin1(Flot1)as a target of SCLC treatment.Methods:Flot1 expression level in the tissue of SCLC and other tissue of lung disease was detected using immunohistochemical staining.Transwell and Matrigel assays were employed to examine migration and invasion of cancer cells.Flow cytometry and xCELLigence system were used to evaluate cell apoptosis and cell viability,respectively.Expression levels of Flot1,epithelialmesenchymal transition(EMT)marker E-cadherin,vimentin,cyclinD1,TGF-β-Smad2/3,and p-AKT were examined using Western blot.Furthermore,xenograft tumor in nude mice was used to evaluate the growth and metastasis of NCI-H446 cells in vivo.Results:Our results demonstrated that Flot1 is highly expressed in SCLC samples and that its expression correlates strongly with clinical stage,distant metastasis,and poor survival.The knockdown of Flot1 decreased the growth,migration,and invasiveness of SCLC cells and reversed EMT phenotype in vitro and in vivo,while enhanced Flot1 expression exhibited the opposite behavior.Gene expression profile analysis demonstrated that Flot1-regulated genes frequently mapped to the AKT and TGF-β-Smad2/3pathways.Our results further revealed that Flot1 affected the progression of SCLC via regulation of EMT progression.Conclusions:These findings indicated an oncogenic role of Flot1 via promoting EMT in SCLC and suggested its potential as a tumor marker and prognostic indicator.
基金supported by a grant from the National Basic Research Program of China(973 Program)(No.2011CB944301)
文摘Spermatogenesis is a complex process of terminal differentiation by which mature sperms are generated,and it can be divided into three phases：mitosis,meiosis and spermiogenesis.In a previous study,we established a series of proteomic profiles for spermatogenesis to understand the regulation of male fertility and infertility.Here,we further investigated the localization and the role of flotillin-2 in spermiogenesis.Flotillin-2 expression was investigated in the testis of male CD1 mice at various developmental stages of spermatogenesis by using Western blotting,immunohistochemistry and immunofluorescence.Flotillin-2 was knocked down in vivo in three-week-old male mice using intratesticular injection of small inhibitory RNA（siRNA）,and sperm abnormalities were assessed three weeks later.Flotillin-2 was expressed at high levels in male germ cells during spermatogenesis.Flotillin-2 immunoreactivity was observed in pachytene spermatocytes as a strong dot-shaped signal and in round spermatids as a sickle-shaped distribution ahead of the acrosome.Immunofluorescence confirmed flotillin-2 was localized in front of the acrosome in round spermatids,indicating that flotillin-2 was localized to the Golgi apparatus.Knockdown of flotillin-2 in vivo led to a significant increase in head sperm abnormalities isolated from the cauda epididymis,compared with control siRNA-injected testes.This study indicates that flotillin-2 is a novel Golgi-related protein involved in sperm acrosome biogenesis.
