scholarly journals S1P Lyase Regulation of Thymic Egress and Oncogenic Inflammatory Signaling

2017 ◽  
Vol 2017 ◽  
pp. 1-19 ◽  
Author(s):  
Ashok Kumar ◽  
Jesus Zamora-Pineda ◽  
Emilie Degagné ◽  
Julie D. Saba

Sphingosine-1-phosphate (S1P) is a potent lipid signaling molecule that regulates pleiotropic biological functions including cell migration, survival, angiogenesis, immune cell trafficking, inflammation, and carcinogenesis. It acts as a ligand for a family of cell surface receptors. S1P concentrations are high in blood and lymph but low in tissues, especially the thymus and lymphoid organs. S1P chemotactic gradients are essential for lymphocyte egress and other aspects of physiological cell trafficking. S1P is irreversibly degraded by S1P lyase (SPL). SPL regulates lymphocyte trafficking, inflammation and other physiological and pathological processes. For example, SPL located in thymic dendritic cells acts as a metabolic gatekeeper that controls the normal egress of mature T lymphocytes from the thymus into the circulation, whereas SPL deficiency in gut epithelial cells promotes colitis and colitis-associated carcinogenesis (CAC). Recently, we identified a complex syndrome comprised of nephrosis, adrenal insufficiency, and immunological defects caused by inherited mutations in human SGPL1, the gene encoding SPL. In the present article, we review current evidence supporting the role of SPL in thymic egress, inflammation, and cancer. Lastly, we summarize recent progress in understanding other SPL functions, its role in inherited disease, and SPL targeting for therapeutic purposes.

2021 ◽  
Vol 22 (12) ◽  
pp. 6492
Author(s):  
Paola Giussani ◽  
Alessandro Prinetti ◽  
Cristina Tringali

Immunotherapy is now considered an innovative and strong strategy to beat metastatic, drug-resistant, or relapsing tumours. It is based on the manipulation of several mechanisms involved in the complex interplay between cancer cells and immune system that culminates in a form of immune-tolerance of tumour cells, favouring their expansion. Current immunotherapies are devoted enforcing the immune response against cancer cells and are represented by approaches employing vaccines, monoclonal antibodies, interleukins, checkpoint inhibitors, and chimeric antigen receptor (CAR)-T cells. Despite the undoubted potency of these treatments in some malignancies, many issues are being investigated to amplify the potential of application and to avoid side effects. In this review, we discuss how sphingolipids are involved in interactions between cancer cells and the immune system and how knowledge in this topic could be employed to enhance the efficacy of different immunotherapy approaches. In particular, we explore the following aspects: how sphingolipids are pivotal components of plasma membranes and could modulate the functionality of surface receptors expressed also by immune cells and thus their functionality; how sphingolipids are related to the release of bioactive mediators, sphingosine 1-phosphate, and ceramide that could significantly affect lymphocyte egress and migration toward the tumour milieu, in addition regulating key pathways needed to activate immune cells; given the renowned capability of altering sphingolipid expression and metabolism shown by cancer cells, how it is possible to employ sphingolipids as antigen targets.


2021 ◽  
Vol 39 (6_suppl) ◽  
pp. TPS191-TPS191
Author(s):  
Omer Kucuk ◽  
Charles Smith ◽  
Terry Plasse ◽  
Besim Ogretmen ◽  
Shikhar Mehrotra ◽  
...  

TPS191 Background: Opaganib (Yeliva, ABC294640) is a first-in-class, sphingosine kinase-2 (SK2) selective inhibitor, with anticancer, anti-inflammatory and anti-viral activities. SK2, a lipid kinase catalyzes formation of the lipid signaling molecule sphingosine 1-phosphate (S1P). S1P promotes cancer growth, and proliferation and pathological inflammation, including inflammatory cytokine production. Specifically, by inhibiting the SK2 enzyme, opaganib blocks the synthesis of S1P which regulates fundamental biological processes such as cell proliferation, migration, immune cell trafficking and angiogenesis, and are also involved in immune-modulation and suppression of innate immune responses from T cells. Opaganib is a sphingosine-competitive inhibitor of SK2 and also inhibits dihydroceramide desaturase. Opaganib has antitumor activity against human and murine prostate cancer cell lines, and in xenograft (LNCaP) and syngeneic (MycCAP, TRAMP-C1) murine tumor models. In addition to its target effect of reducing sphingosine-1-phosphate, opaganib reduces both MYC and AR proteins through its kinase-blocking and desaturase-inhibiting properties, respectively. Methods: The study is open to patients with mCRPC who have been treated with at least one newer androgen antagonist (abiraterone or enzalutamide) and no prior chemotherapy for castration-resistant disease. Patients who are failing either abiraterone or enzalutamide may enroll, with the addition of opaganib. The trial design includes brief safety lead-in cohort 1a (abiraterone + opaganib 250 mg Q 12hr, 3/3 enrolled) and 1b (enzalutamide + opaganib 250 mg Q 12hr, 3/3 enrolled). These cohorts have been completed without any DLTs. We are now enrolling cohort 2 (abiraterone + opaganib 500 mg Q 12hr, 0/27 enrolled) and cohort 3 (enzalutamide + opaganib 500 mg Q 12hr, 8/27 enrolled). A total of 60 patients will be enrolled and response will be evaluated after 4 cycles (28 days/cycle) using a composite metric based on PSA, bone scan and RECIST measurements per PCWG3 criteria. Safety and tolerability will be monitored, and dose modifications will be allowed. Primary endpoint is disease control (stable disease or better) after 4 cycles. Secondary endpoints include overall survival, radiographic progression-free survival and PSA progression-free survival. Correlative studies include assessment of quality of life (QOL), circulating MDSCs, immune cells and clones with amplified AR or MYC. Supported by NIH grant P01 CA203628. Clinical trial information: NCT04207255.


2020 ◽  
Vol 88 (11) ◽  
Author(s):  
Zengzi Zhou ◽  
Lingxiang Xie ◽  
Luying Wang ◽  
Min Xue ◽  
Dabao Xu ◽  
...  

ABSTRACT Fingolimod (FTY720), an FDA-approved immunomodulatory drug for treating multiple sclerosis, is an agonist of sphingosine-1-phosphate receptor (S1PR), which has been used as a research tool for inhibiting immune cell trafficking. FTY720 was recently reported to inhibit Chlamydia dissemination. Since genital Chlamydia spreading to the gastrointestinal tract correlated with its pathogenicity in the upper genital tract, we evaluated the effect of FTY720 on chlamydial pathogenicity in the current study. Following an intravaginal inoculation, live chlamydial organisms were detected in mouse rectal swabs. FTY720 treatment significantly delayed live organism shedding in the rectal swabs. However, FTY720 failed to block chlamydial spreading to the gastrointestinal tract. The live chlamydial organisms recovered from rectal swabs reached similar levels between mice with or without FTY720 treatment by day 42 in C57BL/6J and day 28 in CBA/J mice, respectively. Thus, genital Chlamydia is able to launch a 2nd wave of spreading via an FTY720-resistant pathway after the 1st wave of spreading is inhibited by FTY720. As a result, all mice developed significant hydrosalpinx. The FTY720-resistant spreading led to stable colonization of chlamydial organisms in the colon. Consistently, FTY720 did not alter the colonization of intracolonically inoculated Chlamydia. Thus, we have demonstrated that, following a delay in chlamydial spreading caused by FTY720, genital Chlamydia is able to both spread to the gastrointestinal tract via an FTY720-resistant pathway and maintain its pathogenicity in the upper genital tract. Further characterization of the FTY720-resistant pathway(s) explored by Chlamydia for spreading to the gastrointestinal tract may promote our understanding of Chlamydia pathogenic mechanisms.


Science ◽  
2019 ◽  
Vol 366 (6463) ◽  
pp. eaar5551 ◽  
Author(s):  
Andreane Cartier ◽  
Timothy Hla

Sphingosine 1-phosphate (S1P), a metabolic product of cell membrane sphingolipids, is bound to extracellular chaperones, is enriched in circulatory fluids, and binds to G protein–coupled S1P receptors (S1PRs) to regulate embryonic development, postnatal organ function, and disease. S1PRs regulate essential processes such as adaptive immune cell trafficking, vascular development, and homeostasis. Moreover, S1PR signaling is a driver of multiple diseases. The past decade has witnessed an exponential growth in this field, in part because of multidisciplinary research focused on this lipid mediator and the application of S1PR-targeted drugs in clinical medicine. This has revealed fundamental principles of lysophospholipid mediator signaling that not only clarify the complex and wide ranging actions of S1P but also guide the development of therapeutics and translational directions in immunological, cardiovascular, neurological, inflammatory, and fibrotic diseases.


Cells ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 2189 ◽  
Author(s):  
Shah Alam ◽  
Antonia Piazzesi ◽  
Mariam Abd El Fatah ◽  
Maren Raucamp ◽  
Gerhild van Echten-Deckert

We have shown that sphingosine 1-phosphate (S1P) generated by sphingosine kinase 2 (SK2) is toxic in neurons lacking S1P-lyase (SGPL1), the enzyme that catalyzes its irreversible cleavage. Interestingly, patients harboring mutations in the gene encoding this enzyme (SGPL1) often present with neurological pathologies. Studies in a mouse model with a developmental neural-specific ablation of SGPL1 (SGPL1fl/fl/Nes) confirmed the importance of S1P metabolism for the presynaptic architecture and neuronal autophagy, known to be essential for brain health. We now investigated in SGPL1-deficient murine brains two other factors involved in neurodegenerative processes, namely tau phosphorylation and histone acetylation. In hippocampal and cortical slices SGPL1 deficiency and hence S1P accumulation are accompanied by hyperphosphorylation of tau and an elevated acetylation of histone3 (H3) and histone4 (H4). Calcium chelation with BAPTA-AM rescued both tau hyperphosphorylation and histone acetylation, designating calcium as an essential mediator of these (patho)physiological functions of S1P in the brain. Studies in primary cultured neurons and astrocytes derived from SGPL1fl/fl/Nes mice revealed hyperphosphorylated tau only in SGPL1-deficient neurons and increased histone acetylation only in SGPL1-deficient astrocytes. Both could be reversed to control values with BAPTA-AM, indicating the close interdependence of S1P metabolism, calcium homeostasis, and brain health.


2020 ◽  
Vol 477 (5) ◽  
pp. 925-935 ◽  
Author(s):  
Yugesh Kharel ◽  
Tao Huang ◽  
Anita Salamon ◽  
Thurl E. Harris ◽  
Webster L. Santos ◽  
...  

The interplay of sphingosine 1-phosphate (S1P) synthetic and degradative enzymes as well as S1P exporters creates concentration gradients that are a fundamental to S1P biology. Extracellular S1P levels, such as in blood and lymph, are high relative to cellular S1P. The blood-tissue S1P gradient maintains endothelial integrity while local S1P gradients influence immune cell positioning. Indeed, the importance of S1P gradients was recognized initially when the mechanism of action of an S1P receptor agonist used as a medicine for multiple sclerosis was revealed to be inhibition of T-lymphocytes’ recognition of the high S1P in efferent lymph. Furthermore, the increase in erythrocyte S1P in response to hypoxia influences oxygen delivery during high altitude acclimatization. However, understanding of how S1P gradients are maintained is incomplete. For example, S1P is synthesized but is only slowly metabolized by blood yet circulating S1P turns over quickly by an unknown mechanism. Prompted by the counterintuitive observation that blood S1P increases markedly in response to inhibition S1P synthesis (by sphingosine kinase 2 (SphK2)), we studied mice wherein several tissues were made deficient in either SphK2 or S1P degrading enzymes. Our data reveal a mechanism whereby S1P is de-phosphorylated at the hepatocyte surface and the resulting sphingosine is sequestered by SphK phosphorylation and in turn degraded by intracellular S1P lyase. Thus, we identify the liver as the primary site of blood S1P clearance and provide an explanation for the role of SphK2 in this process. Our discovery suggests a general mechanism whereby S1P gradients are shaped.


2018 ◽  
Vol 25 (36) ◽  
pp. 4758-4784 ◽  
Author(s):  
Amy L. Wilson ◽  
Magdalena Plebanski ◽  
Andrew N. Stephens

Cancer is one of the leading causes of death worldwide, and current research has focused on the discovery of novel approaches to effectively treat this disease. Recently, a considerable number of clinical trials have demonstrated the success of immunomodulatory therapies for the treatment of cancer. Monoclonal antibodies can target components of the immune system to either i) agonise co-stimulatory molecules, such as CD137, OX40 and CD40; or ii) inhibit immune checkpoints, such as cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4), programmed cell death-1 (PD-1) and its corresponding ligand PD-L1. Although tumour regression is the outcome for some patients following immunotherapy, many patients still do not respond. Furthermore, chemotherapy has been the standard of care for most cancers, but the immunomodulatory capacity of these drugs has only recently been uncovered. The ability of chemotherapy to modulate the immune system through a variety of mechanisms, including immunogenic cell death (ICD), increased antigen presentation and depletion of regulatory immune cells, highlights the potential for synergism between conventional chemotherapy and novel immunotherapy. In addition, recent pre-clinical trials indicate dipeptidyl peptidase (DPP) enzyme inhibition, an enzyme that can regulate immune cell trafficking to the tumour microenvironment, as a novel cancer therapy. The present review focuses on the current immunological approaches for the treatment of cancer, and summarizes clinical trials in the field of immunotherapy as a single treatment and in combination with chemotherapy.


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