TRPM2:氧化应激敏感的多功能离子通道(英文)

瞬时受体电位(transient receptor potential,TRP)超家族是一组非选择性阳离子通道,分为7个亚家族。TRPM亚家族包括8个不同的成员,TRPM1~8。TRPM2广泛表达于可兴奋细胞和非兴奋性细胞,形成Ca2+通透性阳离子通道,并发挥不同的细胞功能。TRPM2通道可被ADP-核糖(ADPR)、Ca2+、H2O2以及其他活性氧(ROS)所激活。现已证明,TRPM2作为氧化应激传感器,介导了氧化应激引起的细胞内Ca2+浓度升高,并参与多种细胞的生理/病理过程。丰富的证据表明,TRPM2可作为氧化应激相关疾病的一个潜在的治疗靶点。本文对以上方面的研究进展做一综述。     

肿瘤细胞对血清补体杀伤耐受的机制研究

目的:探讨肿瘤细胞耐受血清补体杀伤的分子机制。方法:将表达不同血型抗原的肿瘤细胞与添加同血型血清的培养基孵育,获得耐受血清杀伤的肿瘤细胞。无血清悬浮培养肿瘤干细胞,对耐受血清杀伤的肿瘤细胞和肿瘤干细胞分别提取mRNA,进行反转录PCR,检测肿瘤干细胞干性标志物和补体调节蛋白的表达情况;干扰补体调节蛋白,检测肿瘤细胞对血清补体的杀伤情况。结果:对分别表达血型抗原A、B和H的HT-29、KATOⅢ、MCF7肿瘤细胞均获得耐受血清杀伤的耐受细胞,耐受细胞高表达三种膜性补体调节蛋白CD46、CD55和CD59,以及部分肿瘤干细胞干性标志物;spheroid悬浮球肿瘤干细胞高表达上述三种膜性补体调节蛋白,特别是CD46;在肿瘤细胞中腺病毒干扰CD46的表达,可显著增强血清补体对肿瘤细胞的杀伤率。结论:补体调节蛋白CD46分子可通过增强肿瘤细胞的干性而介导肿瘤细胞对血清补体的杀伤耐受。     

FGF-2 在细胞凋亡中的作用机制

成纤维细胞生长因子2(fibroblast growth factor 2,FGF-2)具有多种细胞生物学功能。FGF-2在肿瘤组织中呈高水平表达状态,且可抑制多种化疗药物的促凋亡作用,从而曾为肿瘤细胞存活的重要刺激因素。但也有研究表明FGF-2可诱导部分细胞的分化和凋亡。鉴于FGF-2在肿瘤的发生发展中发挥的重要作用,FGF-2与细胞凋亡的关系及其相应的调节机制成为有待于深入研究和迫切需要解决的问题。本文主要阐述在细胞凋亡通路中,FGF-2关键分子的作用机制及其最新研究进展。     

IAP家族分子与肿瘤靶向治疗

凋亡抑制因子(inhibitor of apoptosis proteins,IAPs)是一类高度保守的内源性抗细胞凋亡因子家族,主要通过抑制Caspase活性和参与调节核因子NF-κB的作用而抑制细胞凋亡。细胞抗凋亡机制在肿瘤发生、发展以及肿瘤耐药性形成中发挥重要作用。肿瘤细胞高表达IAPs是导致肿瘤细胞抵抗凋亡的关键。细胞凋亡调控异常与肿瘤细胞耐药密切相关,增强肿瘤细胞对化疗药物的敏感性成为近年来肿瘤治疗的重要策略之一。该文综述了IAP家族蛋白的结构、生物学特性及其作为肿瘤治疗靶点的研究进展。     

姜黄素抗肿瘤的机制

姜黄素具有很显著的抗肿瘤作用。本文通过对几年来国内外对姜黄素抗肿瘤的研究进行总结,介绍了姜黄素的抗肿瘤机制。在分子水平上,肿瘤细胞摄取姜黄素,增加药物作用的靶位点,调节肿瘤细胞的信号传递,从而调节肿瘤细胞中某些酶活性及蛋白质、基因的表达。在细胞水平上,姜黄素能抑制肿瘤细胞的增殖、促进肿瘤细胞凋亡、逆转肿瘤细胞的多药耐药性、增强NK细胞杀伤力。在组织水平上抑制肿瘤血管生成等方面来发挥抗肿瘤作用。     

白细胞介素-8与肿瘤免疫逃逸

IL-8是趋化因子CXC家族的一员,是一种多细胞来源的细胞因子,在细胞的多种炎症反应中起调节作用,并且在自身免疫性疾病中也发挥重要作用。IL-8通过与细胞膜上的CXC趋化因子受体CXCR1和CXCR2相互作用,激活偶联的G蛋白,由G蛋白进一步激活PLC、AC、PLD、PI3K、JAK2及Ras等信号分子,从而调控基因表达、细胞增殖和分化、细胞代谢、细胞运动及血管生成等多种细胞生命过程。IL-8在多种恶性肿瘤细胞中表达量升高,其高表达与肿瘤细胞增殖、迁移、侵袭、血管生成及上皮间充质转化有密切联系。肿瘤免疫逃逸是肿瘤细胞产生和转移过程中的主要特征之一,肿瘤细胞可以通过多种机制使得人体免疫系统无法对其进行正常的识别和攻击,从而导致肿瘤细胞在体内存活,并且不断增殖和转移,而肿瘤细胞、免疫细胞以及肿瘤微环境中其他相关组分均可以促进肿瘤免疫逃逸。IL-8作为一种炎性趋化因子,已被证明在肿瘤免疫逃逸中具有重要作用,其可通过诱导肿瘤细胞PD-L1表达、抑制肿瘤细胞凋亡、促进肿瘤细胞EMT进程、促进肿瘤微环境血管生成、招募免疫抑制性细胞等五个方面介导肿瘤免疫逃逸。IL-8中和抗体和CXCR1/2拮抗剂在抗肿瘤治疗方面已经显示出较好的治疗效果。     

Nrf2的代谢调节作用与肿瘤的生长和增殖

核转录因子Nrf2[nuclear factor erythroid 2(NFE2)related factor 2]是细胞内重要的调节因子。通过与Keap1(Kelch-like-ECH associated protein 1)蛋白质的相互作用,Nrf2可以调控下游基因转录,发挥抗氧化应激、维持细胞内稳态的功能,而Nrf2在肿瘤细胞中的表达与肿瘤的发生发展具有重要关系。Nrf2通过调节肿瘤细胞代谢模式调控细胞生长和增殖,近年来成为了细胞生物学和肿瘤生物学领域的研究热点之一。该文介绍了Nrf2对于活性氧分子产生与清除以及多种物质代谢途径的调控作用,着重阐明Nrf2的代谢调节作用对肿瘤细胞生长增殖的影响及其与肿瘤耐药的关系,旨在为今后的临床研究提供更多信息。     

原卟啉Ⅸ-声动力学疗法诱导S180肿瘤细胞的凋亡

采用频率为2.2MHz,声强为3W/cm2的低强度聚焦超声结合原卟啉Ⅸ对S180肿瘤细胞的损伤以及诱导细胞凋亡的发生进行研究,并探讨其作用的分子机制。超声激活原卟啉Ⅸ作用于S180肿瘤细胞处理后,不同时间段取材,通过Annexin V-PI荧光双染观察凋亡细胞的形态学变化;采用TUNEL末端标记法检测细胞凋亡的发生率;利用间接免疫荧光技术和免疫细胞化学技术检测细胞内凋亡相关蛋白Caspase-8、Caspase-3以及死亡底物聚ADP核糖聚合酶[poly(ADP-ribose)polymerase,PARP]的表达活性变化。实验结果显示:超声激活原卟啉Ⅸ可以诱导S180肿瘤细胞凋亡的发生,并且凋亡细胞的比例随着取材时间的延迟明显增加;免疫细胞化学染色表明声动力学处理显著增强了细胞内Caspase-8和Caspase-3的蛋白表达活性,并且其活化程度分别于处理后1h和3h达到最高,而死亡底物PARP也发生时间相关性剪切。研究表明,超声结合原卟啉Ⅸ可以通过诱导细胞凋亡的方式发挥其抗肿瘤活性,其作用的分子机制可能涉及到膜受体介导的Caspase-8、Caspase-3以及PARP依赖性的凋亡信号调节通路     

瞬时感受器电位M2通道抗原位点的兔单抗特异性检测

目的：筛选特异性较高的抗体以推动对瞬时感受器电位M2（TRPM2）通道结构和功能的研究。方法：以野生型昆明种小鼠大脑皮层、人胚肾293细胞、未诱导的TRPM2细胞及四环素诱导的TRPM2细胞为标本,采用免疫印迹和免疫荧光方法,以被检测抗体为一抗,荧光分子结合的抗体为二抗,根据170kD（TRPM2通道蛋白分子量）位置上是否有特异性条带,检测兔单抗的特异性。结果：抗体98927对鼠源TRPM2通道有特异性,抗体40622,抗体98721,抗体98921对人源TRPM2通道有特异性,另外抗体98721对鼠源TRPM2通道的突变型有特异性。结论：作为分子探针,抗体98927、40622、98721、98921可用于TRPM2通道结构和功能研究。     

蛋白激酶AKT 不同亚型影响乳腺癌恶性表型的研究进展

细胞的增殖、转移、存活等细胞生物学过程的异常对人类众多疾病尤其是恶性肿瘤的发生发展至关重要。大量研究表明,PI3K/AKT信号通路的异常激活在肿瘤的恶性转化过程中发挥重要作用并具有普遍意义。但是,目前的研究多集中于探讨AKT总的激酶活性,而往往忽视了AKT不同亚型的特异性功能。近年来在乳腺癌中的研究发现,AKT家族不同亚型的激酶分子在调控肿瘤细胞的存活、生长、增殖、代谢、转移等众多恶性表型方面发挥独特而关键的作用:与Akt1促进肿瘤细胞增殖、抑制肿瘤细胞转移的作用相反,Akt2在促进肿瘤细胞转移、抑制肿瘤细胞增殖方面发挥重要功能;此外,随着对AKT家族研究的深入,人们对Akt3的特异性生物学功能也有了新的认识。本文在此对AKT不同亚型与乳腺癌恶性表型之间关系的研究进展做一总结。     

TRP channel–associated factors are a novel protein family that regulates TRPM8 trafficking and activity

TRPM8 is a cold sensor that is highly expressed in the prostate as well as in other non-temperature-sensing organs, and is regulated by downstream receptor–activated signaling pathways. However, little is known about the intracellular proteins necessary for channel function. Here, we identify two previously unknown proteins, which we have named “TRP channel–associated factors” (TCAFs), as new TRPM8 partner proteins, and we demonstrate that they are necessary for channel function. TCAF1 and TCAF2 both bind to the TRPM8 channel and promote its trafficking to the cell surface. However, they exert opposing effects on TRPM8 gating properties. Functional interaction of TCAF1/TRPM8 also leads to a reduction in both the speed and directionality of migration of prostate cancer cells, which is consistent with an observed loss of expression of TCAF1 in metastatic human specimens, whereas TCAF2 promotes migration. The identification of TCAFs introduces a novel mechanism for modulation of TRPM8 channel activity.     

瞬时受体电位M8离子通道功能及其翻译后修饰调节机制

瞬时受体电位M8(transient receptor potential melastatin 8, TRPM8)又称冷及薄荷醇感受器,位于细胞膜或细胞器膜上,是瞬时受体电位(transient receptor potential, TRP)通道超家族中的一员。TRPM8通道分布广泛,是一个非选择性阳离子通道,可作为冷热传感器和冷痛传感器进行信号传导,参与众多生物过程的调节,在维持细胞内外稳态、控制离子进出细胞方面具有重要作用。研究发现,蛋白质翻译后修饰(post-translational modification, PTM)通过调控TRPM8通道的功能,进而影响多种疾病的发生和发展。因此,探究TRPM8的翻译后修饰的过程,对深入了解TRPM8的功能及调控机制是十分必要的。目前,已报道的TRPM8翻译后修饰包括磷酸化、泛素化和糖基化等,它们能够调控蛋白质的相互作用和改变TRPM8离子通道的活性,从而调控细胞增殖、迁移和凋亡。值得注意的是,TRPM8的表达与前列腺癌、膀胱癌和乳腺癌等多种癌症密切相关。本文将从TRPM8离子通道的结构出发,系统地阐述TRPM8蛋白翻译后修饰和激动剂、...     

TRPM7 is required for ovarian cancer cell growth,migration and invasion

Our previous study demonstrated that the melastatin-related transient receptor potential channel 7 (TRPM7) was highly expressed in ovarian carcinomas and its overexpression was significantly associated with poor prognosis in ovarian cancer patients. However, the function of TRPM7 in ovarian cancer is mostly unknown. In this study, we examined the roles of TRPM7 in ovarian cancer cell proliferation, migration and invasion. We found that short hairpin RNA interference-mediated silence of TRPM7 significantly inhibited cell proliferation, colony formation, migration and invasion in multiple ovarian cancer cell lines. Mechanistic investigation revealed that silence of TRPM7 decreased phosphorylation levels of Akt, Src and p38 and increased filamentous actin and focal adhesion number in ovarian cancer cells. Thus, our results suggest that TRPM7 is required for proliferation, migration and invasion of ovarian cancer cells through regulating multiple signaling transduction pathways and the formation of focal adhesions.     

Regulation of TRPM8 channel activity by Src-mediated tyrosine phosphorylation

The transient receptor potential melastatin type 8 (TRPM8) receptor channel is expressed in primary afferent neurons where it is the main transducer of innocuous cold temperatures and also in a variety of tumors, where it is involved in progression and metastasis. Modulation of this channel by intracellular signaling pathways has therefore important clinical implications. We investigated the modulation of recombinant and natively expressed TRPM8 by the Src kinase, which is known to be involved in cancer pathophysiology and inflammation. Human TRPM8 expressed in HEK293T cells is constitutively tyrosine phosphorylated by Src which is expressed either heterologously or endogenously. Src action on TRPM8 potentiates its activity, as treatment with PP2, a selective Src kinase inhibitor, reduces both TRPM8 tyrosine phosphorylation and cold-induced channel activation. RNA interference directed against the Src kinase diminished the extent of PP2-induced functional downregulation of TRPM8, confirming that PP2 acts mainly through Src inhibition. Finally, the effect of PP2 on TRPM8 cold activation was reproduced in cultured rat dorsal root ganglion neurons, and this action was antagonized by the protein tyrosine phosphatase inhibitor pervanadate, confirming that TRPM8 activity is sensitive to the cellular balance between tyrosine kinases and phosphatases. This positive modulation of TRPM8 by Src kinase may be relevant for inflammatory pain and cancer signaling.     

LncRNA DGUOK-AS1 facilitates non-small cell lung cancer growth and metastasis through increasing TRPM7 stability via m6A modification

BackgroundN6-methyladenosine (m6A) modification plays key roles in tumor progression. LncRNA deoxyguanosine kinase antisense RNA 1 (DGUOK-AS1) has been reported as a promoter in tumors, but its role and mechanism in non-small cell lung cancer (NSCLC) development remain uncertain.MethodsCell proliferation, migration, invasion and angiogenesis were investigated via CCK-8, colony formation, transwell, and tube formation assays, respectively. The location of DGUOK-AS1 was detected via FISH assay. The interaction relationship among DGUOK-AS1, IGF2BP2 and TRPM7 was confirmed by RIP and MeRIP assays. The effects of DGUOK-AS1 on NSCLC growth and metastasis in vivo were investigated using xenograft and pulmonary metastatic models.ResultsDGUOK-AS1 was upregulated in NSCLC. DGUOK-AS1 silencing inhibited NSCLC cell proliferation, migration, invasion and angiogenesis. DGUOK-AS1 was mostly expressed in cytoplasm, and positively regulated IGF2BP2. METTL3/IGF2BP2 axis could increase TRPM7 mRNA stability in m6A-dependent manner. TRPM7 overexpression reversed the inhibitive function of DGUOK-AS1 silencing on NSCLC development. DGUOK-AS1 knockdown suppressed NSCLC cell growth and metastasis in nude mice.ConclusionDGUOK-AS1 silencing restrains NSCLC cell growth and metastasis through decreasing TRPM7 stability via regulation of the METTL3/IGF2BP2-mediated m6A modification.     

TRPM channels, calcium and redox sensors during innate immune responses

Melastatin-related TRPM ion channels have emerged as novel therapeutic targets due to their potential ability to modulate the function and fate of immune cells during inflammation, innate, and adaptive immunity. Four family members, TRPM1, TRPM2, TRPM4 and TRPM7 have a strong presence in the immune system. TRPM channels regulate ion-homeostasis by sensing cellular redox status and cytoplasmic calcium levels. TRPM2 for example, is highly expressed in phagocytes. This channel is activated by intracellular ADP-ribose upon exposure to oxidative stress and induces cell death. Here we will review the functional links between TRPM-mediated ion conductance, chemotaxis, apoptosis, and innate immunity.     

TRPM7 and its role in neurodegenerative diseases

Calcium (Ca²⁺) and magnesium (Mg²⁺) ions have been shown to play an important role in regulating various neuronal functions. In the present review we focus on the emerging role of transient potential melastatin-7 (TRPM7) channel in not only regulating Ca²⁺ and Mg²⁺ homeostasis necessary for biological functions, but also how alterations in TRPM7 function/expression could induce neurodegeneration. Although eight TRPM channels have been identified, the channel properties, mode of activation, and physiological responses of various TRPM channels are quite distinct. Among the known 8 TRPM channels only TRPM6 and TRPM7 channels are highly permeable to both Ca²⁺ and Mg²⁺; however here we will only focus on TRPM7 as unlike TRPM6, TRPM7 channels are abundantly expressed in neuronal cells. Importantly, the discrepancy in TRPM7 channel function and expression leads to various neuronal diseases such as Alzheimer disease (AD) and Parkinson disease (PD). Further, it is emerging as a key factor in anoxic neuronal death and in other neurodegenerative disorders. Thus, by understanding the precise involvement of the TRPM7 channels in different neurodegenerative diseases and by understanding the factors that regulate TRPM7 channels, we could uncover new strategies in the future that could evolve as new drug therapeutic targets for effective treatment of these neurodegenerative diseases.     

TRPM7 and its role in neurodegenerative diseases

Calcium (Ca²⁺) and magnesium (Mg²⁺) ions have been shown to play an important role in regulating various neuronal functions. In the present review we focus on the emerging role of transient potential melastatin-7 (TRPM7) channel in not only regulating Ca²⁺ and Mg²⁺ homeostasis necessary for biological functions, but also how alterations in TRPM7 function/expression could induce neurodegeneration. Although eight TRPM channels have been identified, the channel properties, mode of activation, and physiological responses of various TRPM channels are quite distinct. Among the known 8 TRPM channels only TRPM6 and TRPM7 channels are highly permeable to both Ca²⁺ and Mg²⁺; however here we will only focus on TRPM7 as unlike TRPM6, TRPM7 channels are abundantly expressed in neuronal cells. Importantly, the discrepancy in TRPM7 channel function and expression leads to various neuronal diseases such as Alzheimer disease (AD) and Parkinson disease (PD). Further, it is emerging as a key factor in anoxic neuronal death and in other neurodegenerative disorders. Thus, by understanding the precise involvement of the TRPM7 channels in different neurodegenerative diseases and by understanding the factors that regulate TRPM7 channels, we could uncover new strategies in the future that could evolve as new drug therapeutic targets for effective treatment of these neurodegenerative diseases.