鞘氨醇-1-磷酸受体1在疼痛中的作用研究

鞘氨醇-1-磷酸受体1(sphingosine-1-phosphate receptor1,S1PR1)属于G蛋白偶联受体,其能调节多种下游信号分子和细胞功能。研究发现S1PR1在疼痛中发挥重要作用,但激活S1PR1产生致痛作用还是镇痛作用尚存在争议。该文讨论了S1P/S1PR1信号在疼痛研究中的最新观点与进展,以增进对其生物学功能及病理作用的了解。     

新型免疫抑制剂鞘氨醇-1-磷酸受体激动剂研究进展

免疫抑制剂在器官移植和自身免疫系统疾病的治疗方面疗效显著,但多种不良反应限制了其广泛应用。在寻找高活性、低不良反应的新型免疫抑制剂的过程中发现,鞘氨醇-1-磷酸（S1P）受体激动剂通过使淋巴细胞聚集在淋巴结、脾等次级淋巴器官中,导致血液和胸腺的淋巴细胞减少,同时抑制淋巴细胞进入移植器官中,减少移植排斥反应。因此,通过激动S1P受体阻断淋巴细胞循环可以用于治疗免疫系统疾病。本文主要综述新型免疫抑制剂S1P受体全激动剂和选择性激动剂的特点、作用机制及研究进展。     

鞘胺醇-1-磷酸受体1选择性调节剂的研究进展

鞘氨醇-1-磷酸（sphingosine-1-phosphate,S1P）是调节细胞内外多种生物学功能的重要信号分子。S1P通过结合5种G蛋白偶联受体（G protein-coupled receptors,GPCRs）亚型介导多重下游信号通路产生相关的细胞生理功能。近年来,对选择性鞘氨醇-1-磷酸受体1（sphingosine-1-phosphate receptor 1,S1PR1）调节剂的研究已成为发现免疫性疾病治疗药物的热点。综述总结了近年来S1PR1调节剂的研究进展,对构效关系进行了讨论,并在此基础上探讨了此类调节剂的发展方向。     

鞘氨醇激酶和1-磷酸鞘氨醇及其受体信号在肿瘤微环境中的研究进展

鞘氨醇激酶(SphK)、1-磷酸鞘氨醇(S1P)及其受体(S1PR)参与肿瘤细胞增殖、迁移等生物学过程,在癌症的发生发展中起重要作用。近年来,研究者日益关注癌细胞与肿瘤微环境之间的相互作用,肿瘤微环境具有遗传稳定性并且能够被诱导为抗肿瘤表型,具有显著的治疗优势。研究显示, SphK/S1P/S1PR能够调节肿瘤微环境的多个方面。本文从肿瘤免疫微环境、癌症相关成纤维细胞、肿瘤血管生成、肿瘤缺氧微环境4个角度对SphK和S1P/S1PR信号对肿瘤微环境的影响进行综述,并简要概述相关药物研究情况,旨在阐明SphK/S1P/S1PR在癌症中的作用及为抗肿瘤药物的研究提供新思路。     

1-磷酸鞘氨醇及其信号通路在炎症相关性疾病中的作用

1-磷酸鞘氨醇(sphingosine 1-phosphate,S1P)是细胞膜鞘磷脂在代谢过程中产生的一类重要的信号分子,S1P可被转运到细胞外,通过作用于S1P受体,激活一系列下游信号分子发挥作用,如Ras/Raf/ERK、PI3K/Akt等,也可作为第二信使直接作用于细胞内靶点,如HDAC、TRAF2。其介导的信号通路在很多生理和病理过程中发挥作用,如细胞增殖和迁移、炎性细胞因子浸润、血管生成、自身免疫等。该文分别从S1P的胞外及胞内两种作用方式,探讨S1P及其信号通路在炎症相关性疾病中的作用,综述S1P信号通路相关药物研究进展。     

1-磷酸鞘氨醇对过氧化氢所致微血管通透性增高的影响

目的研究1-磷酸鞘氨醇(S1P)对氧化应激状态下过氧化氢引起的大鼠微血管通透性增高的影响。方法应用大鼠在体肠系膜微血管灌注的方法,通过外源性给予过氧化氢模拟病理条件下氧化应激状态,并通过测定微静脉的静水传导性(hydraulic conductivity,Lp),观察S1P对过氧化氢引起的微血管通透性增高的影响;并利用在体免疫荧光组织化学技术,观察S1P对过氧化氢引起的内皮细胞粘附连接主要成分钙粘蛋白(VE-Cadherin)、F-肌动蛋白变化的影响。结果过氧化氢可增加微血管Lp至正常对照的6.13±0.87倍(P<0.01);微血管经S1P预处理后,再给予过氧化氢未出现Lp的明显变化,与对照值比较无显著性差异。免疫荧光组织化学检测结果显示:过氧化氢可改变内皮细胞F-肌动蛋白形态及分布,细胞F-肌动蛋白分布紊乱不规则,细胞内部有密集的应力纤维形成。过氧化氢也可影响VE-Cadherin正常结构,导致粘附连接断裂,细胞间隙形成。而S1P预处理可抑制过氧化氢对VE-Cadherin和F-肌动蛋白的影响。结论 S1P可抑制过氧化氢引起的血管通透性增高,其机制可能与S1P抑制应力纤维形成、加强内皮细胞间粘附连接,抑制细胞间隙形成有关。     

一磷酸鞘氨醇受体2在肠癌中的阳性率及意义

目的 探讨一磷酸鞘氨醇受体2(S1PR2)在肠癌中的阳性率及意义.方法 收集2017年9月至2019年9月于九江市第一人民医院行肠癌根治术患者的组织,采用免疫组化检测肿瘤组织及切缘正常组织中S1PR2的表达,分析S1PR2在肠癌中的阳性率及其与临床参数的关系.结果 相对于正常组织,肿瘤组织中S1PR2的阳性率降低(26...     

人脐静脉内皮细胞 1-磷酸鞘氨醇受体鉴定及其应用探讨

摘要： 目的 鉴定人脐静脉内皮融合细胞株 EA.hy926 和人脐静脉内皮细胞 （HUVEC） CRL-1730 1-磷酸鞘氨醇受体 （S1PR） 亚型和胞浆中 C-myc 及 His 标签蛋白的表达情况, 为研究载脂蛋白 M （ApoM） -1-磷酸鞘氨醇轴 （ApoMS1P 轴） 的功能提供参考。方法 体外培养 EA.hy926 及 CRL-1730 至细胞密度达到 60%～70%时, 采用细胞免疫荧光技术鉴定内皮细胞标志凝血八因子（FⅧ）、 ApoM、 S1PR1~S1PR5、 C-myc 和 His 标签蛋白。结果 （1）两种细胞均表达 FⅧ和 ApoM, FⅧ在 CRL-1730 中呈散在颗粒状分布, 在 EA.hy926 中呈均匀分布。（2）两种细胞均主要表达 S1PR1, 少量表达 S1PR2 和 S1PR3, 不表达 S1PR4 和 S1PR5。（3）两种细胞胞浆中均有 C-myc 和 His 标签蛋白的表达。结论 两种细胞都具有内皮细胞的特性; 因其自身表达 ApoM、 C-myc 和 His 标签蛋白, 在应用这两种细胞研究 ApoM-S1P 轴的功能时, 不适合选用带有 C-myc 和 （或） His 标签的重组 ApoM 蛋白。     

选择性鞘胺醇-1-磷酸受体1激动剂研究进展

鞘胺醇-1-磷酸 (S1P) 是调节细胞内外多种生物学功能的重要信号分子。S1P可通过结合5种G蛋白偶联受体亚型 (S1PR₁₋₅) 介导多重下游信号通路产生相关的细胞生理功能, 其中激动S1PR₁可以达到调节免疫的作用。新型S1PR₁激动剂芬戈莫德 (Fingolimod, FTY-720) 已完成临床研究成为自身免疫性疾病——多发性硬化症的治疗药物。选择性S1PR₁激动剂的研究已成为发现免疫性疾病治疗药物的热点。本文总结了近年来该领域的研究进展, 着重介绍S1PR₁激动剂的结构类型和构效关系研究, 并探讨了此类激动剂的发展方向。     

LC-MS/MS检测血浆中1-磷酸鞘氨醇含量分析方法的建立

目的:建立可以快速检测人血浆中1-磷酸鞘氨醇(S1P)的LC-MS/MS定量分析方法。方法:采用C17-S1P作为内参,甲醇一步法进行蛋白沉淀,随后进行正相电喷雾离子化LC-MS/MS分析。流动相为甲醇-0.1%甲酸水(95∶5,v/v),流速0.2ml/min,每个样品的分析时间为4min。结果:对于所有的质控样品,批内和批间精确度均小于12%。测定人血浆S1P的浓度为67.6ng/ml。结论:该方法可以快速、灵敏、特异性地检测血浆中S1P的含量。     

Stimulation of intracellular sphingosine-1-phosphate production by G-protein-coupled sphingosine-1-phosphate receptors

Recently, a family of G-protein-coupled receptors named endothelial differentiation gene (Edg) receptor family has been identified, which are specifically activated by the two serum lipids, sphingosine-1-phosphate and lysophosphatidic acid. Sphingosine-1-phosphate can also act intracellularly to release Ca2+ from intracellular stores. Since in several cell types, G-protein-coupled lysophosphatidic acid or sphingosine-1-phosphate receptors mobilize Ca2+ in the absence of a measurable phospholipase C stimulation, it was analysed here whether intracellular sphingosine-1-phosphate production was the signalling mechanism used by extracellular sphingosine-1-phosphate for mobilization of stored Ca2+. Sphingosine-1-phosphate and the low affinity sphingosine-1-phosphate receptor agonist, sphingosylphosphorylcholine, induced a rapid, transient and nearly complete pertussis toxin-sensitive Ca2+ mobilization in human embryonic kidney (HEK-293) cells. The G-protein-coupled sphingosine-1-phosphate receptors, Edg-1, Edg-3 and Edg-5, were found to be endogenously expressed in these cells. Most interestingly, sphingosine-1-phosphate and sphingosylphosphorylcholine did not induce a measurable production of inositol-1,4,5-trisphosphate or accumulation of inositol phosphates. Instead, sphingosine-1-phosphate and sphingosylphosphorylcholine induced a rapid and transient increase in production of intracellular sphingosine-1-phosphate with a maximum of about 1.4-fold at 30 s. Stimulation of sphingosine-1-phosphate formation by sphingosine-1-phosphate and sphingosylphosphorylcholine was fully blocked by pertussis toxin, indicating that extracellular sphingosine-1-phosphate via endogenously expressed G(i)-coupled receptors induces a stimulation of intracellular sphingosine-1-phosphate production. As sphingosine-1-phosphate- and sphingosylphosphorylcholine-induced increases in intracellular Ca2+ were blunted by sphingosine kinase inhibitors, this sphingosine-1-phosphate production appears to mediate Ca2+ signalling by extracellular sphingosine-1-phosphate and sphingosylphosphorylcholine in HEK-293 cells.     

The role of sphingosine-1-phosphate and its receptors in asthma

Sphingosine-1-phosphate (S1P) is a bioactive sphingolipid metabolite that plays important roles in allergic responses, including asthma and anaphylaxis, the incidence of which is rising worldwide especially in industrialized urban populations. In this review, we will discuss how S1P is formed and released, and how it acts at many cellular levels, including mast cells, the airway epithelium, airway smooth muscle and many immune cells. Since the actions of S1P on all of these cells could exacerbate allergic responses, the proteins that synthesize, release and respond to S1P offer plausible targets for a new generation of antiinflammatory therapeutics.     

Targeting sphingosine-1-phosphate receptors in cancer

Sphingosine 1-phosphate (S1P) is a bioactive lipid with diverse biological functions, including cell proliferation, differentiation, angiogenesis, chemotaxis, and migration. Many of the activities of S1P are mediated through five closely related G-protein-coupled receptors of the sphingosine-1-phosphate receptor family (S1PR) which play a crucial role in sphingolipid metabolism. Each of these receptors appears to be tissue specific and to have demonstrated roles in the regulation of cell proliferation and survival in various cancer types. Further analysis of the function that S1PRs serve in hematological malignancies offers a great potential for the discovery of novel and selective therapeutic agents targeting these receptors. This review focuses on the characterization of S1PRs and their roles in cancer development in various signaling pathways mediated through specific G coupled protein. In particular, pharmacological agents targeting these S1PRs will be discussed and their potential will be examined.     

Vascular sphingosine-1-phosphate S1P1 and S1P3 receptors

The sphingolipid sphingosine-1-phosphate (S1P) acts on five subtypes of G-protein- coupled receptors, termed S1P(1) (formerly endothelial differentiation gene-1 [Edg-1]), S1P(2) (Edg-5), S1P(3) (Edg-3), S1P(4) (Edg-6) and S1P(5) (Edg-8), and possibly several other "orphan" receptors, such as GPR3, GPR6 and GPR12. These receptors are coupled to different intracellular second messenger systems, including adenylate cyclase, phospholipase C, phosphatidylinositol 3-kinase/protein kinase Akt, mitogen-activated protein kinases, as well as Rho- and Ras-dependent pathways. Consistently with this receptor multiplicity and pleiotropic signaling mechanisms, S1P influences numerous cell functions. S1P(1)1, S1P(2) and S1P(3) receptors are the major S1P receptor subtypes in the cardiovascular system, where they mediate the effects of S1P released from platelets, and possibly other tissues (such as brain). Thus S1P(1) and S1P(3) receptors enhance endothelial and vascular smooth muscle cell proliferation and migration, playing a key role in developmental and pathological angiogenesis. In contrast, S1P(2) receptors inhibit migration of these cell types, probably because of their unique stimulatory effect on a GTPase-activating protein inhibiting the activity of Rac. S1P receptors can also cause relaxation and constriction of blood vessels. The former effect is mediated by pertussis toxin-sensitive receptors (possibly S1P(1)) located on the endothelium and stimulating phosphatidylinositol 3-kinase/Akt/endothelial nitric oxide synthase (eNOS). The vasoconstricting effect of S1P is likely to be mediated by S1P(2) and/or S1P(3) receptors, via Rho-Rho-kinase, and is more potent in coronary and cerebral blood vessels. Finally, S1P also protects endothelial cells from apoptosis through activation of phosphatidylinositol 3-kinase/Akt/eNOS via S1P(1) and S1P(3) receptors. The variety of these effects, taken together with the existence of multiple receptor subtypes, provides an abundance of therapeutic targets that currently still await the development of selective agents.     

The role of sphingosine-1-phosphate and ceramide-1-phosphate in calcium homeostasis

During the last several years, sphingolipids have been identified as a source of important signaling molecules. Particularly, the understanding of the distinct biological roles of ceramide, sphingosine-1-phosphate (S1P), ceramide-1-phosphate (C1P) and lyso-sphingomyelin in the regulation of cell growth, death, senescence, adhesion, migration, inflammation, angiogenesis and intracellular trafficking has rapidly expanded. Additional studies have elucidated the biological roles of sphingolipids in maintaining a homeostatic environment in cells, as well as in regulating numerous cellular responses to environmental stimuli. This review focuses on the role of S1P and C1P in maintaining Ca2+ homeostasis. By studying changes in the metabolism of S1P and C1P in pathological conditions, it is hoped that altered sphingolipid-metabolizing enzymes and their metabolites can be used as therapeutic targets.     

Targeting sphingosine-1-phosphate in hematologic malignancies

Sphingosine-1-phosphate (S1P) is a pleiotropic bioactive lipid mediator that regulates several processes important for hematologic cancer progression. S1P is generated by two sphingosine kinases, SphK1 and SphK2, and is exported outside the cell, where it activates specific cell surface S1P G-protein coupled receptors in autocrine/paracrine manner, coined "inside-out signaling". In this review, we highlight the importance of SphK1 and inside-out signaling by S1P in hematologic malignancy. We also summarize the results of studies targeting the SphK1/S1P/S1P receptor axis and the effects of the S1P receptor modulator, FTY720, in hematologic malignancy.     

Effects of synthetic sphingosine-1-phosphate analogs on arachidonic acid metabolism and cell death

Sphingolipid metabolites such as sphingosine regulate cell functions including cell death and arachidonic acid (AA) metabolism. D-erythro-C18-Sphingosine-1-phosphate (D-e-S1P), a sphingolipid metabolite, acts as an intracellular messenger in addition to being an endogenous ligand of some cell surface receptors. The development of S1P analogs may be useful for studying and/or regulating S1P-mediated cellular responses. In the present study, we found that several synthetic S1P analogs at pharmacological concentrations stimulated AA metabolism and cell death in PC12 cells. D-erythro-N,O,O-Trimethyl-C18-S1P (D-e-TM-S1P), L-threo-O,O-dimethyl-C18-S1P (L-t-DM-S1P) and L-threo-O,O-dimethyl-3O-benzyl-C18-S1P (L-t-DMBn-S1P) at 100 microM stimulated [(3)H]AA release from the prelabeled PC12 cells. L-t-DMBn-S1P at 20 microM increased prostanoid formation in PC12 cells. L-t-DMBn-S1P-induced AA release was inhibited by D-e-sphingosine, but not by the tested PLA(2) inhibitors. L-t-DMBn-S1P did not stimulate the activity of cytosolic phospholipase A(2alpha) (cPLA(2alpha)) in vitro and the translocation of cPLA(2alpha) in the cells, and caused AA release from the cells lacking cPLA(2alpha). These findings suggest that L-t-DMBn-S1P stimulated AA release in a cPLA(2alpha)-independent manner. In contrast, D-e-S1P and D-erythro-N-monomethyl-C18-S1P caused cell death without AA release in PC12 cells, and the effects of D-e-TM-S1P, L-t-DM-S1P and L-t-DMBn-S1P on cell death were limited. Synthetic S1P analogs may be useful tools for studying AA metabolism and cell death in cells.     

Heterologous desensitization of the sphingosine-1-phosphate receptors by purinoceptor activation in renal mesangial cells

1 Sphingosine-1-phosphate (S1P) is considered a potent mitogen for mesangial cells and activates the classical mitogen-activated protein kinase (MAPK) cascade via S1P receptors. In this study, we show that S1P signalling is rapidly desensitized upon S1P receptor activation. A complete loss of S1P sensitivity occurs after 10 min of S1P pretreatment and remains for at least 8 h. A similar desensitization is also seen with the S1P mimetic FTY720-phosphate, but not with the nonphosphorylated FTY720, nor with sphingosine or ceramide. 2 Prestimulating the cells with extracellular ATP or UTP, which bind to and activate P2Y receptors on mesangial cells, a similar rapid desensitization of the S1P receptor occurs, suggesting a heterologous desensitization of S1P receptors by P2Y receptor activation. Furthermore, adenosine binding to P1 receptors triggers a similar desensitization. In contrast, two other growth factors, PDGF-BB and TGFbeta2, have no significant effect on S1P-induced MAPK activation. 3 S1P also triggers increased inositol trisphosphate (IP3) formation, which is completely abolished by S1P pretreatment but only partially by ATP pretreatment, suggesting that IP3 formation and MAPK activation stimulated by S1P involve different receptor subtypes. 4 Increasing intracellular cAMP levels by forskolin pretreatment has a similar effect on desensitization as adenosine. Moreover, a selective A3 adenosine receptor agonist, which couples to phospholipase C and increases IP3 formation, exerted a similar effect. 5 Pretreatment of cells with various protein kinase C (PKC) inhibitors prior to ATP prestimulation and subsequent S1P stimulation leads to a differential reversal of the ATP effect. Whereas the broad-spectrum protein kinase inhibitor staurosporine potently reverses the effect, the PKC-alpha inhibitor CGP41251, the PKC-delta inhibitor rottlerin and calphostin C show only a partial reversal at maximal concentrations. 6 Suramin, which is reported as a selective S1P3 receptor antagonist compared to the other S1P receptor subtypes, has no effect on the S1P-induced MAPK activation, thus excluding the involvement of S1P3 in this response. 7 In summary, these data document a rapid homologous and also heterologous desensitization of S1P signalling in mesangial cells, which is mechanistically triggered by PKC activation and eventually another staurosporine-sensitive protein kinase, as well as by increased cAMP formation.     

Effects of sphingosine-1-phosphate,a lipid mediator,in cardiovascular tissues

Effects of sphingosine-1-phosphate (S1P), a putative lipid mediator, was examined in vascular smooth muscle and endothelial cells by means of measuring intracellular Ca2+ concentration ([Ca2+]i), whole-cell membrane currents and tension. Application of S1P in a concentration range from 30 to 1000 nM to human umbilical vein endothelial cells (HUVECs) induced a slowly developing increase in [Ca2+]i. and concomitant non-selelctive cationic inward currents. Pretreatment of HUVECs with pertussis toxin (PTX) almost abolished the S1P-induced elevation of [Ca2+]i, suggesting that PTX sensitive edg1 receptors are involved in the S1P-induced response in HUVECs. Moreover, treatment of HUVECs with S1P for 24 hrs caused cell-proliferation to 150% of the control. On the other hand, application of S1P had no effect on [Ca2+]i in rabbit, rat and mouse aortic myocytes. When S1P applied to rabbit aorta with endothelium, the muscle ring had small relaxation which disappeared in endothelium-denuded aorta. In contrast, rat cerebral arterial myocytes had increase in [Ca2+]i in the presence of S1P. These results suggest that responses of vascular tissues to S1P vary from cell to cell. To clarify physiological and pharmacological significance of S1P in cardiovascular system, comprehensive analyses are required.