1-磷酸鞘氨醇受体的研究进展

1-磷酸鞘氨醇S1P(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之一,作用于S1P受体后,在很多生理和病理过程中发挥重要的调节作用。Sphk-S1P-S1PR信号通路及其在炎症、肿瘤、动脉粥样硬化、自体免疫系统疾病、神经系统疾病等多种疾病中的作用已成为目前研究的热点之一。越来越多的S1P受体调节剂被研发。     

鞘氨醇-1-磷酸信号激活对乳腺癌MCF-7细胞增殖作用机制研究

目的 研究鞘氨醇-1-磷酸(S1P)信号激活在乳腺癌MCF-7细胞增殖中的作用及其机制.方法 (1)将细胞分为空白组和低、中、高3个浓度实验组,实验组用SEW2871(S1P受体激动剂)处理乳腺癌细胞72 h.四甲基偶氮唑蓝法检测细胞增殖.(2)将转染的乳腺癌细胞分为3组:第1转染组、第2转染组和第3转染组.第1转染组...     

1-磷酸鞘氨醇及受体对自身免疫性疾病血管新生的影响

1-磷酸鞘氨醇(sphingosine-1-phosphate,S1P)是细胞膜鞘磷脂代谢过程产生的一类信号分子,在免疫系统中,与细胞膜表面的G蛋白偶联受体S1P受体(S1P receptors,S1PRs)结合,通过相关炎症信号通路,影响新生血管的形成。该文简述S1P及其受体通过细胞内信号转导对类风湿关节炎、多发性硬化症、结肠炎、系统性红斑狼疮等自身免疫性疾病微血管生成的影响,提出了S1P及其受体可能是治疗自身免疫性疾病血管炎症新的靶点。     

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。     

治疗多发性硬化症的选择性鞘胺醇-1-磷酸受体1激动剂的临床研究进展

多发性硬化（ NS）是一种常见的中枢神经脱髓鞘疾病,主要表现为肌体无力,感觉异常,眼部障碍,记忆力衰退,认知障碍等。根据多发性硬化的种类的不同,需采用不同的药物治疗。     

鞘氨醇-1-磷酸受体调节剂siponimod的药理作用及临床评价

siponimod是由诺华公司研发的一种鞘氨醇-1-磷酸受体(sphingosine-1-phosphate receptor,S1PR)调节剂,能选择性地与S1PR1和S1PR5结合,阻止淋巴细胞离开淋巴结,用于治疗成人复发型多发性硬化症,2019年3月获FDA批准上市。本文对其药理作用、药动学、临床研究及不良反应等进行归纳总结。     

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。     

黄连素调节鞘氨醇激酶-1-磷酸鞘氨醇信号通路抗糖尿病小鼠肾损伤的研究

目的研究黄连素对四氧嘧啶诱导的糖尿病小鼠肾损伤的保护作用及其对糖尿病小鼠肾脏鞘氨醇激酶-1-磷酸鞘氨醇(SphK-S1P)信号通路的抑制效应。方法四氧嘧啶诱导的糖尿病小鼠采用黄连素(300 mg.kg-1.d-1)灌胃给药12周,正常组和糖尿病组小鼠给予同体积的溶媒。采用Re-al-time PCR技术检测肾组织中SphK1、TGF-β1、FN、ColⅣ的基因;Western blot法检测肾脏组织中SphK1、FN、ColⅣ的蛋白表达;LC-MS/MS检测肾脏组织中SphK1活性和S1P含量。结果黄连素明显抑制糖尿病小鼠血糖,肾重/体重比、血尿素氮、血肌酐和24 h尿蛋白异常增高;抑制肾脏肥大、纤维连接蛋白和Ⅳ型胶原积聚。此外,黄连素明显减少肾脏SphK1活性、mRNA和蛋白表达,降低S1P的生成。结论黄连素发挥抗糖尿病小鼠肾损伤的作用可能与抑制肾脏SphK-S1P信号通路的激活相关联。     

1-磷酸鞘氨醇后适应对人脐静脉内皮细胞缺氧/复氧损伤的保护作用

目的研究1-磷酸鞘氨醇(S1P)后适应对人脐静脉内皮细胞(HUVEC)缺氧/复氧损伤的保护作用,并探讨其作用机制。方法建立HUVEC缺氧/复氧损伤模型,将HUVEC细胞分为5组,正常对照组、S1P低剂量组、S1P中剂量组、S1P高剂量组以及缺氧/复氧损伤(H/R)组。MTT法检测细胞存活率;流式细胞术分析测定细胞凋亡率;比色法测定细胞培养液中总超氧化物歧化酶(total superoxide disnmtase,TSOD)、铜锌超氧化物歧化酶(copper/zinc superoxide dismutase,CuZn-SOD)和锰超氧化物歧化酶(manganese superoxide dismutase,Mn-SOD)活力以及一氧化氮(nitric oxide,NO)、丙二醛(malondialdehyde,MDA)含量;荧光显微镜下观察线粒体膜电位;Western blot测定HUVECs细胞Bcl-2/Bax、eNOS蛋白的表达水平。结果与H/R组相比,S1P低、中、高剂量组可明显增加HUVECs细胞缺氧/复氧损伤后细胞存活率;均明显升高T-SOD活力、CuZn-SOD活力、Mn-SOD活力,降低MDA含量,明显升高NO含量及增加eNOS蛋白表达,降低凋亡率,抑制线粒体膜电位下降。结论 S1P能够使H/R损伤的HUVECs细胞凋亡率降低,且呈一定的浓度依赖性。S1P对H/R损伤的HUVECs细胞凋亡的保护作用可能与降低细胞内MDA含量,提高细胞内SOD活力,提升线粒体膜电位,增强抗凋亡蛋白Bcl-2/Bax的表达有关。     

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。     

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.     

Role of sphingosine-1-phosphate (S1P) and the S1P2 receptor in allergen-induced, mast cell-dependent contraction of rat lung parenchymal strips

Lung parenchymal strips isolated from ovalbumin-sensitized rats manifest a mast cell-dependent, biphasic contraction when challenged with allergen. The first phase is mediated by the release of preformed 5-HT while the second phase is dependent on de novo synthesis of leukotrienes. Sphingosine 1-phosphate (S1P) is a sphingolipid metabolite which is readily generated in mast cells and has been demonstrated to be an important regulator of allergen-induced mast cell activation. We have used the parenchymal strip to explore the role of sphingosine 1-phosphate and the S1P₂ receptor in the two components of the acute response to allergen. Lung parenchymal strips were prepared from Brown Norway rats actively sensitized to ovalbumin. The strips were set up in organ baths and contractile responses measured isometrically. The inhibitors of sphingosine kinase, D-erythro-NN-dimethylsphingosine (dimethylsphingosine) and 4-[4-(4-chloro-phenyl)-thiazol-2-ylamino]-phenol (SKI-II) inhibited concentration-dependently both phases of the contractile response induced by 0.1 µg ml^?1 ovalbumin. The effects were seen at concentrations similar to those which inhibit the purified enzyme and were selective in that neither the contractile response to adenosine nor that to 5-hydroxytryptamine was affected. JTE-013 (a selective S1P₂ receptor antagonist) also blocked the response to ovalbumin (0.1 µg ml^?1). However, the concentrations of JTE-013 required (µM) were substantially higher than its affinity for the S1P₂ receptors (nM). However, when tested against a lower concentration of ovalbumin (0.03 µg ml^?1), JTE-013 inhibited the response with nM potency. These data demonstrate the importance of S1P and the S1P₂ receptor as regulators of allergen-induced activation of mast cells in their natural environment in the rat lung.     

Different response patterns of several ligands at the sphingosine-1-phosphate receptor subtype 3 (S1P3)

Background and purpose:

Recently, some ligands targeting the sphingosine-1-phosphate receptor subtype 3 (S1P₃) have become available. The characterization of these compounds was mainly based on one functional read-out system, although S1P₃ receptors are known to activate different signal transduction pathways. Therefore, this study pharmacologically characterizes these compounds using different assays.

Experimental approach:

Using CHO-FlpIn cells expressing the human S1P₃ receptor the potencies and maximal effects of S1P, FTY720-P, VPC23019, VPC23153 and VPC24191 were determined in three different assays [inhibition of cAMP accumulation, elevation of intracellular calcium concentrations ([Ca²⁺]_i) and S1P₃ receptor internalization].

Key results:

All compounds tested inhibited forskolin-induced cAMP accumulation, increased [Ca²⁺]_i and induced S1P₃ receptor internalization but with different potencies and maximal effects. S1P was the most potent compound in all assays followed by FTY720-P. The VPC compounds were generally less potent than S1P and FTY720-P. Regarding the maximal effects, all compounds except VPC23153, behaved as full agonists in the cAMP accumulation assay. In the calcium assay, FTY720-P, VPC23019 and VPC24191 displayed partial and VPC23153 weak partial agonist activity, relative to S1P. Interestingly, treatment with the G_i inactivator Pertussis toxin, did not affect S1P-induced [Ca²⁺]_i elevations but inhibited those in response to the other compounds, by about 50%.

Conclusions and implications:

This study demonstrated differential response patterns at the S1P₃ receptor for a range of ligands. These differences could indicate the presence of functional selectivity at this receptor as FTY720-P and the VPC compounds seemed to signal predominantly via G_i– whereas S1P activated G_i and G_q-coupled pathways.     

BML-241 fails to display selective antagonism at the sphingosine-1-phosphate receptor, S1P(3)

BACKGROUND AND PURPOSE: The thiazolidine carboxylic acid, BML-241, has been proposed as a lead compound in development of selective antagonists at the sphingosine-1-phosphate receptor (S1P3), based on its inhibition of the rise in intracellular calcium concentrations ([Ca2+]i) in HeLa cells overexpressing S1P receptors. We have studied the antagonistic properties of BML-241 for the S1P(3) receptor in more detail. EXPERIMENTAL APPROACH: Chinese hamster ovary (CHO) cells stably transfected with the S1P3, S1P2 or alpha(1A)-adrenoceptors were used to investigate the effect of BML-241 on increases in [Ca2+]i mediated via different receptors. CHO-K1 cells were used to study ATP-induced [Ca2+]i elevations. Effects on S1P3 -mediated inhibition of forskolin-induced cAMP accumulation and on binding to alpha(1A)-adrenoceptors were also investigated. In addition, the effect of BML-241 on contractions of rat mesenteric artery induced by phenylephrine was studied in an organ bath. KEY RESULTS: High concentrations of BML-241 (10 microM) inhibited the rise in [Ca2+]i induced by S1P3 and S1P2 receptor stimulation; lower concentrations were ineffective. This high concentration of BML-241 also inhibited [Ca2+]i increases via P2 (nucleotide) receptor or alpha(1A)-adrenoceptor stimulation. Moreover, BML-241 (10 microM) inhibited alpha(1)-adrenoceptor-mediated contraction of rat mesenteric artery but did not displace [3H]-prazosin from alpha(1A)-adrenoceptors in concentrations up to 100 microM. BML-241 (10 microM) did not affect the S1P3 -mediated decrease of forskolin-induced cAMP accumulation. CONCLUSIONS AND IMPLICATIONS: We conclude that BML-241 is a low potency, non-selective inhibitor of increases in [Ca2+]i, rather than a specific antagonist at the S1P3 receptor.     

S1P3 receptors mediate the potent constriction of cerebral arteries by sphingosine-1-phosphate

We characterized the effect of Sphingosine-1-phosphate (S1P) on vascular tone. S1P selectively constricted isolated cerebral, but not peripheral arteries, despite ubiquitous expression of S1P(1), S1P(2), S1P(3) and S1P(5) receptor mRNA. Clostridium B and C3 toxins and the rho-kinase inhibitor Y27632 (trans-N-(4-pyridyl)-4-(l-aminoethyl)-cyclohexane carboxamide) reduced this vasoconstriction to S1P, indicating that the response was mediated through Rho. Pertussis toxin displayed only weak inhibition, suggesting minor involvement of G(i/o) protein. The S1P effect was specifically reduced by adenovirus bearing a s1p(3) but not s1p(2), antisense construct. Furthermore, suramin, which selectively blocks S1P(3) receptors, inhibited the vasoconstrictor effect of S1P, indicating that S1P(3) receptors account for at least part of S1P-mediated vasoconstriction in cerebral arteries. In vivo, intracarotid injection of S1P decreased cerebral blood flow, an effect prevented by suramin treatment. Because S1P constricts cerebral blood vessels and is released from platelets during clotting, the S1P/S1P(3) system constitutes a novel potential target for cerebrovascular disease therapy.     

Involvement of sphingosine-1-phosphate and S1P1 in angiogenesis: Analyses using a new S1P1 antagonist of non-sphingosine-1-phosphate analog

Chemical lead 2 (CL2) is the first non-sphingosine-1-phosphate (Sph-1-P) analog type antagonist of endothelial differentiation gene-1 (Edg-1/S1P₁), which is a member of the Sph-1-P receptor family. CL2 inhibits [³H]Sph-1-P/S1P₁ binding and shows concentration-dependent inhibition activity against both intracellular cAMP concentration decrease and cell invasion induced by the Sph-1-P/S1P₁ pathway. It also inhibits normal tube formation in an angiogenesis culture model, indicating that CL2 has anti-angiogenesis activity. This compound improved the disease conditions in two angiogenic models in vivo. It significantly inhibited angiogenesis induced by vascular endothelial growth factor in a rabbit cornea model as well as the swelling of mouse feet in an anti-type II collagen antibody-induced arthritis model. These results indicate that the Sph-1-P/S1P₁ pathway would have an important role in disease-related angiogenesis, especially in the processes of migration/invasion and tube formation. In addition, CL2 would be a powerful tool for the pharmacological study of the mechanisms of the Sph-1-P/S1P₁ pathway in rheumatoid arthritis, diabetes retinopathy, and solid tumor growth processes.     

Involvement of p38 MAP kinase-mediated cytochrome c release on sphingosine-1-phosphate (S1P)- and N-monomethyl-S1P-induced cell death of PC12 cells

d-erythro-Sphingosine-1-phosphate (S1P), a sphingolipid metabolite, affects various neuronal functions including cell fate. S1P appears to have contradictory effects in PC12 cells, a neuronal model cell line; neurite retraction and cell survival/differentiation. In the present study, we examined whether S1P induces cell death in undifferentiated PC12 cells. Culture with S1P at 20 microM for 4 h caused lactate dehydrogenase leakage 24 h later. The response was reduced by an inhibitor of caspases and accompanied by the release of cytochrome c and DNA fragmentation. S1P caused the phosphorylation of p38 mitogen-activated protein kinase (p38 MAPK) within 10 min. An inhibitor of p38 MAPK (10 microM SB203580) inhibited both the release of cytochrome c and DNA fragmentation induced by S1P. Treatment with nerve growth factor or pertussis toxin (PTX) decreased S1P-induced phosphorylation of p38 MAPK and cell death. These findings suggest that S1P-activated p38 MAPK acts as a death signal upstream of the release of cytochrome c. N-Monomethyl-S1P (MM-S1P), a weak agonist in cells expressing S1P1 receptors, had marked effects (phosphorylation of p38 MAPK, release of cytochrome c and DNA fragmentation) at lower concentrations than S1P and in a PTX-sensitive manner. These findings show that the activation of S1P receptors by S1P and MM-S1P causes cell death accompanied by DNA fragmentation via the p38 MAPK pathway-mediated release of cytochrome c in PC12 cells. The potential of S1P and MM-S1P to act as agonists of S1P receptors and as intracellular messengers is discussed.