Exogenous and intracellularly generated sphingosine 1-phosphate can regulate cellular processes by divergent pathways

2003 ◽  
Vol 31 (6) ◽  
pp. 1216-1219 ◽  
Author(s):  
S. Spiegel ◽  
S. Milstien

S1P (sphingosine 1-phosphate) is the ligand for a family of specific G-protein-coupled receptors that regulate a wide variety of important cellular functions, including vascular maturation, angiogenesis, cell growth, survival, cytoskeletal rearrangements and cell motility. However, S1P also may have intracellular functions. In this review, we discuss two examples that clearly indicate that intracellularly generated and exogenous S1P can regulate biological processes by divergent pathways.

Blood ◽  
2003 ◽  
Vol 102 (10) ◽  
pp. 3665-3667 ◽  
Author(s):  
Maria L. Allende ◽  
Tadashi Yamashita ◽  
Richard L. Proia

AbstractSphingosine-1-phosphate (S1P) stimulates signaling pathways via G-protein-coupled receptors and triggers diverse cellular processes, including growth, survival, and migration. In S1P1 receptor-deficient embryos, blood vessels were incompletely covered by vascular smooth muscle cells (VSMCs), indicating the S1P1 receptor regulates vascular maturation. Because S1P1 receptor expression is not restricted to a particular cell type, it was not known whether the S1P1 receptor controlled VSMC coverage of vessels in a cell-autonomous fashion by functioning directly in VSMCs or indirectly through its activity in endothelial cells (ECs). By using the Cre/loxP system, we disrupted the S1P1 gene solely in ECs. The phenotype of the conditional mutant embryos mimicked the one obtained in the embryos globally deficient in S1P1. Thus, vessel coverage by VSMCs is directed by the activity of the S1P1 receptor in ECs. (Blood. 2003;102:3665-3667)


Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2988
Author(s):  
Zhen Zeng ◽  
Chunxiang Ma ◽  
Kexin Chen ◽  
Mingshan Jiang ◽  
Reshma Vasu ◽  
...  

It is well established that gastrointestinal (GI) cancers are common and devastating diseases around the world. Despite the significant progress that has been made in the treatment of GI cancers, the mortality rates remain high, indicating a real need to explore the complex pathogenesis and develop more effective therapeutics for GI cancers. G protein-coupled receptors (GPCRs) are critical signaling molecules involved in various biological processes including cell growth, proliferation, and death, as well as immune responses and inflammation regulation. Substantial evidence has demonstrated crucial roles of GPCRs in the development of GI cancers, which provided an impetus for further research regarding the pathophysiological mechanisms and drug discovery of GI cancers. In this review, we mainly discuss the roles of sphingosine 1-phosphate receptors (S1PRs), angiotensin II receptors, estrogen-related GPCRs, and some other important GPCRs in the development of colorectal, gastric, and esophageal cancer, and explore the potential of GPCRs as therapeutic targets.


2009 ◽  
Vol 297 (2) ◽  
pp. C451-C458 ◽  
Author(s):  
Chi-Lun Chang ◽  
Ming-Chih Ho ◽  
Po-Huang Lee ◽  
Chi-Yen Hsu ◽  
Wei-Pang Huang ◽  
...  

Sphingosine 1-phosphate (S1P) is a platelet- and endothelial cell-released lysophospholipid that regulates various cellular functions through activating a specific family of G protein-coupled receptors. Both platelet activation and angiogenesis play important roles in cancer development, implying that cancer cells might encounter a large amount of S1P during these processes. Cancer cells, in the meantime, may experience nutrient deprivation and rely on autophagy for early development. Whether extracellular S1P regulates autophagy remains to be tested. In the present work, we investigated whether autophagy is regulated by S1P in PC-3 cells. Through monitoring the modification patterns of LC3 by Western blotting, we demonstrated that autophagy was induced by exogenously applied S1P in PC-3 cells. This observation was further confirmed by fluorescence microscopy using PC-3 cells stably expressing enhanced green fluorescent protein-LC3. By applying small interfering RNA and dihydro-S1P, S1P5 activation was found to be involved in this process. Besides, mammalian target of rapamycin signaling was inhibited upon S1P treatment. Taken together, our results suggest that, under serum-starved conditions, S1P further upregulates autophagic activity through S1P5-dependent pathways in PC-3 cells.


2008 ◽  
Vol 410 (2) ◽  
pp. 427-437 ◽  
Author(s):  
Erika Kovacs ◽  
Karoly Liliom

S1P (sphingosine 1-phosphate) and SPC (sphingosylphosphorylcholine) have been recently recognized as important mediators of cell signalling, regulating basic cellular processes such as growth, differentiation, apoptosis, motility and Ca2+ homoeostasis. Interestingly, they can also act as first and second messengers. Although their activation of cell-surface G-protein-coupled receptors has been studied extensively, not much is known about their intracellular mechanism of action, and their target proteins are yet to be identified. We hypothesized that these sphingolipids might bind to CaM (calmodulin), the ubiquitous intracellular Ca2+ sensor. Binding assays utilizing intrinsic tyrosine fluorescence of the protein, dansyl-labelled CaM and surface plasmon resonance revealed that SPC binds to both apo- and Ca2+-saturated CaM selectively, when compared with the related lysophospholipid mediators S1P, LPA (lysophosphatidic acid) and LPC (lysophosphatidylcholine). Experiments carried out with the model CaM-binding domain melittin showed that SPC dissociates the CaM–target peptide complex, suggesting an inhibitory role. The functional effect of the interaction was examined on two target enzymes, phosphodiesterase and calcineurin, and SPC inhibited the Ca2+/CaM-dependent activity of both. Thus we propose that CaM might be an intracellular receptor for SPC, and raise the possibility of a novel endogenous regulation of CaM.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Guangmeng Xu ◽  
Zecheng Yang ◽  
Yamin Sun ◽  
Hongmei Dong ◽  
Jingru Ma

AbstractSphingosine-1-phosphate (S1P), a pleiotropic lipid mediator, participates in various cellular processes during tumorigenesis, including cell proliferation, survival, drug resistance, metastasis, and angiogenesis. S1P is formed by two sphingosine kinases (SphKs), SphK1 and SphK2. The intracellularly produced S1P is delivered to the extracellular space by ATP-binding cassette (ABC) transporters and spinster homolog 2 (SPNS2), where it binds to five transmembrane G protein-coupled receptors to mediate its oncogenic functions (S1PR1-S1PR5). MicroRNAs (miRNAs) are small non-coding RNAs, 21–25 nucleotides in length, that play numerous crucial roles in cancer, such as tumor initiation, progression, apoptosis, metastasis, and angiogenesis via binding to the 3′‐untranslated region (3′‐UTR) of the target mRNA. There is growing evidence that various miRNAs modulate tumorigenesis by regulating the expression of SphKs, and S1P receptors. We have reviewed various roles of miRNAs, SphKs, S1P, and S1P receptors (S1PRs) in malignancies and how notable miRNAs like miR-101, miR-125b, miR-128, and miR-506, miR-1246, miR-21, miR-126, miR499a, miR20a-5p, miR-140-5p, miR-224, miR-137, miR-183-5p, miR-194, miR181b, miR136, and miR-675-3p, modulate S1P signaling. These tumorigenesis modulating miRNAs are involved in different cancers including breast, gastric, hepatocellular carcinoma, prostate, colorectal, cervical, ovarian, and lung cancer via cell proliferation, invasion, angiogenesis, apoptosis, metastasis, immune evasion, chemoresistance, and chemosensitivity. Therefore, understanding the interaction of SphKs, S1P, and S1P receptors with miRNAs in human malignancies will lead to better insights for miRNA-based cancer therapy.


2014 ◽  
Vol 19 (7) ◽  
pp. 1079-1089 ◽  
Author(s):  
Yingjie Zhu ◽  
John Watson ◽  
Mengjie Chen ◽  
Ding Ren Shen ◽  
Melissa Yarde ◽  
...  

G protein–coupled receptors (GPCRs) are one of the most popular and proven target classes for therapeutic intervention. The increased appreciation for allosteric modulation, receptor oligomerization, and biased agonism has led to the development of new assay platforms that seek to capitalize on these aspects of GPCR biology. High-content screening is particularly well suited for GPCR drug discovery given the ability to image and quantify changes in multiple cellular parameters, to resolve subcellular structures, and to monitor events within a physiologically relevant environment. Focusing on the sphingosine-1-phosphate (S1P1) receptor, we evaluated the utility of high-content approaches in hit identification efforts by developing and applying assays to monitor β-arrestin translocation, GPCR internalization, and GPCR recycling kinetics. Using these approaches in combination with more traditional GPCR screening assays, we identified compounds whose unique pharmacological profiles would have gone unnoticed if using a single platform. In addition, we identified a compound that induces an atypical pattern of β-arrestin translocation and GPCR recycling kinetics. Our results highlight the value of high-content imaging in GPCR drug discovery efforts and emphasize the value of a multiassay approach to study pharmacological properties of compounds of interest.


2021 ◽  
Vol 12 ◽  
Author(s):  
Roberta Lattanzi ◽  
Cinzia Severini ◽  
Daniela Maftei ◽  
Luciano Saso ◽  
Aldo Badiani

The prokineticin (PK) family, prokineticin 1 and Bv8/prokineticin 2 (PROK2), initially discovered as regulators of gastrointestinal motility, interacts with two G protein-coupled receptors, PKR1 and PKR2, regulating important biological functions such as circadian rhythms, metabolism, angiogenesis, neurogenesis, muscle contractility, hematopoiesis, immune response, reproduction and pain perception. PROK2 and PK receptors, in particular PKR2, are widespread distributed in the central nervous system, in both neurons and glial cells. The PROK2 expression levels can be increased by a series of pathological insults, such as hypoxia, reactive oxygen species, beta amyloid and excitotoxic glutamate. This suggests that the PK system, participating in different cellular processes that cause neuronal death, can be a key mediator in neurological/neurodegenerative diseases. While many PROK2/PKRs effects in physiological processes have been documented, their role in neuropathological conditions is not fully clarified, since PROK2 can have a double function in the mechanisms underlying to neurodegeneration or neuroprotection. Here, we briefly outline the latest findings on the modulation of PROK2 and its cognate receptors following different pathological insults, providing information about their opposite neurotoxic and neuroprotective role in different pathological conditions.


1998 ◽  
Vol 330 (2) ◽  
pp. 605-609 ◽  
Author(s):  
C. M. Gerben ZONDAG ◽  
R. Friso POSTMA ◽  
Ingrid VAN ETTEN ◽  
Ingrid VERLAAN ◽  
H. Wouter MOOLENAAR

Sphingosine 1-phosphate (S1P) and lysophosphatidic acid (LPA) are structurally related lipid mediators that act on distinct G-protein-coupled receptors to evoke similar responses, including Ca2+ mobilization, adenylate cyclase inhibition, and mitogen-activated protein (MAP) kinase activation. However, little is still known about the respective receptors. A recently cloned putative LPA receptor (Vzg-1/Edg-2) is similar to an orphan Gi-coupled receptor termed Edg-1. Here we show that expression of Edg-1 in Sf9 and COS-7 cells results in inhibition of adenylate cyclase and activation of MAP kinase (Gi-mediated), but not Ca2+ mobilization, in response to S1P. These responses are specific in that (i) S1P action is not mimicked by LPA, and (ii) Vzg-1/Edg-2 cannot substitute for Edg-1. Thus the Edg-1 receptor is capable of mediating a subset of the cellular responses to S1P.


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