Search Results (84)

Adoptive cell therapy (ACT) using tumor-infiltrating lymphocytes (TILs) has achieved clinically and biologically relevant responses in patients with solid cancer. Clinical efficacy has been increasingly linked to a specific T-cell phenotype, particularly CD8⁺ TILs exhibiting a progenitor stem-cell-like profile (CD39⁻ CD69⁻). This review explores the critical role of the sphingosine-1-phosphate (S1P) axis in orchestrating these responses. We detail the biological antagonism between the activation marker CD69 and S1P receptor 1 (S1PR1), where mutual exclusivity dictates thymic selection, if T-cells are retained in tissues or allowed to recirculate and maintain long-term immune surveillance. The S1PR1:S1P axis is further recognized as a critical regulator of mitochondrial fitness, sustaining the high energetic demands of precursor T-cells. We examine the “double-edged sword” nature of S1P in the tumor microenvironment (TME), where it can drive pro-tumorigenic processes like angiogenesis and vascular mimicry (VM), be hijacked by cancer cells to create immune-excluded environments, or S1P can increase T-cell fitness. We summarize the current landscape of clinical trials (as of January 2026) that target S1P production or signaling to modulate anti-tumor responses or use S1P as a biologically relevant marker of treatment outcome. Full article

Women living with HIV face an increased burden of spontaneous preterm birth (sPTB); however, the underlying immunological mechanisms of sPTB and its association with HIV infection are poorly understood. Although the limited earlier literature implicates sphingosine-1-phosphate (S1P), a lysosphingolipid signaling molecule, in reproductive biology, the association of S1P signaling with HIV and sPTB has not been investigated. We examined whether two S1P signaling components, S1P receptors and sphingosine kinases, are expressed in the female reproductive tract and whether levels are associated with HIV status or spontaneous preterm birth. We quantified the mRNA expression of sphingosine-1-phosphate receptors 1 and 3 (S1PR1/S1PR3) and sphingosine kinases 1 and 2 (SPHK1/SPHK2) in 167 banked vaginal swab specimens collected between 14 and 26 weeks of gestation in a longitudinal pregnancy cohort in Lusaka, Zambia. We evaluated the expression of S1PR1, S1PR3, SPHK1, and SPHK2 by real-time quantitative reverse transcription PCR (RT-qPCR) in four groups (n = 41–42 each): women without HIV (WWoH) with term birth (≥37 weeks of gestation; TB), WWoH with spontaneous preterm birth (<37 weeks of gestation, sPTB), women with HIV (WWH) with TB, and WWH with sPTB. We found that S1P receptors and sphingosine kinases are expressed in the female reproductive tract. SPHK1 and SPHK2 mRNA expression were generally comparable among women independent of HIV status or birth outcome, though SPHK2 trended toward higher expression in women with HIV and women with sPTB. In contrast, S1PR1 mRNA trended toward higher expression in WWH vs. WWoH overall, as well as in WWH vs. WWoH among women with sPTB. Similarly, S1PR3 mRNA expression was greater in women with HIV than in women without HIV, and WWH, both with TB and sPTB, had higher S1PR3 mRNA expression than WWoH with TB. Perturbations in S1PR1 and S1PR3 mRNA expression may be associated with inflammation related to HIV infection and spontaneous preterm birth, suggesting that further studies of S1P signaling in pregnancy, especially among women with HIV, are warranted. Full article

Stroke is the leading cause of death and long-term disability worldwide, with ischemic stroke accounting for nearly 87% of all cases. Vascular occlusion, a key pathological event in ischemic stroke, has been reliably reproduced in preclinical studies using permanent ischemic stroke models. This study demonstrated the neuroprotective effect of NXC736, a functional antagonist of sphingosine-1-phosphate receptor 4 (S1P₄, currently in phase II clinical trials for alopecia areata), against acute injury in mice with permanent middle cerebral artery occlusion (pMCAO). pMCAO-challenged mice received oral NXC736 1 h after occlusion. NXC736 demonstrated substantial therapeutic activity against permanent ischemic stroke by attenuating pMCAO-induced acute brain infarction, neurological deficits, and apoptosis. Additionally, NXC736 reduced blood–brain barrier disruption and edema in the injured brain. Moreover, NXC736 reduced microglial activation and proliferation, oxidative stress, and suppressed pro-inflammatory cytokine expression, suggesting that the efficacy of NXC736 in permanent ischemic stroke is associated with the suppression of neuroinflammatory responses. Mechanistically, we found that NXC736-mediated neuroprotective effects were dependent on the inactivation of NF-κB and MAPKs, including ERK1/2, JNK, and p38. Collectively, our findings indicate that NXC736 is an effective neuroprotective drug for permanent ischemic brain stroke, highlighting S1P₄ as a promising therapeutic target for ischemic stroke. Full article

Background: Pseudomonas aeruginosa infection is a major driver of morbidity and mortality in cystic fibrosis (CF), yet disease severity varies widely among people with CF (pwCF). This clinical heterogeneity suggests the involvement of host genetic modifiers beyond CFTR. We previously identified sphingosine 1-phosphate receptor 1 (S1PR1) as a candidate gene associated with susceptibility to P. aeruginosa. Here, we investigated its role in modulating airway epithelial responses to infection. Methods: Using CRISPR/Cas9, we generated S1PR1-knockout bronchial epithelial cells with (IB3-1) and without (C38) CFTR mutations. We assessed cell viability, cytotoxicity, and interleukin-8 secretion following exposure to P. aeruginosa exoproducts. S1PR1 protein expression was evaluated in lung tissue from pwCF and non-CF individuals using immunohistochemistry. Results: S1PR1-mutant cells produced truncated, non-functional peptides. In CFTR-mutant cells, S1PR1 loss reduced viability, increased cytotoxicity, and significantly enhanced interleukin-8 production in response to P. aeruginosa exoproducts. These effects were not observed in CFTR-competent cells. Notably, S1PR1 protein levels were markedly lower in lung tissue from pwCF compared to non-CF individuals. Conclusions: S1PR1 deficiency exacerbates epithelial damage and inflammatory responses to P. aeruginosa in CF models. These findings highlight S1PR1 as a potential contributor to infection severity and a promising target for therapeutic strategies in pwCF. Full article

Hashimoto’s thyroiditis (HT) is the most common autoimmune thyroid disorder, characterized by progressive lymphocytic infiltration, follicular destruction, tissue fibrosis, and an elevated risk of thyroid carcinoma. While the precise mechanisms underlying HT remain incompletely defined, emerging evidence implicates dysregulated sphingolipid (SPL) metabolism, particularly the sphingosine-1-phosphate (S1P) signaling axis, as a central contributor to disease pathogenesis. S1P, a bioactive lipid mediator, integrates metabolic and immunological cues to regulate immune cell trafficking, cytokine production, apoptosis, and fibroblast activation. Aberrant activation of the sphingosine kinase (SPHK)/sphingosine-1-phosphate (S1P)/S1P receptor (S1PR) pathway has been linked to persistent T helper 1 (Th1) cell recruitment, signal transducer and activator of transcription 3 (STAT3)-mediated immune polarization, epithelial–mesenchymal transition, extracellular matrix remodeling, and the establishment of a chronic inflammatory and fibrotic microenvironment. Moreover, S1P signaling may foster a pro-tumorigenic niche, providing a mechanistic explanation for the strong epidemiological association between HT and papillary thyroid carcinoma. This review summarizes current insights into the role of SPL metabolism in HT, highlighting its potential as a mechanistic link between autoimmunity, fibrosis, and carcinogenesis. Full article

Background: Type 2 diabetes mellitus (T2DM) is a rapidly expanding worldwide health issue associated with impairments in memory and executive functions. The bioactive sphingolipid sphingosine-1-phosphate (S1P) regulates cell death/survival and the inflammatory response by acting on S1P receptors (S1PRs). Unfortunately, the role of S1PRs signaling in the T2DM brain remains elusive. Methods: The effect of fingolimod (FTY720, S1PRs modulator) on the behavior and expression profile of genes encoding S1PRs, sphingosine kinases (SPHK1 and 2), glucose transporters, proteins engaged in insulin signaling, sirtuin 1 (SIRT1), and proinflammatory cytokines in the brain cortex and hippocampus of diabetic mice was examined. Results: We observed a significant reduction in S1pr1, Sirt1, and insulin-like growth factor-1 (Igf1) gene expression that was accompanied by elevation of Sphk2, S1pr3, Il6, and Tnf in T2DM mice. Moreover, animals showed anxiety-like behavior and memory deficits. Fingolimod administration recovered downregulated S1pr1, Sirt1, and Igf1 expression and upregulated Slc2a4 (GLUT-4) and Ide (insulin-degrading enzyme). Furthermore, FTY720 reduced the elevated expression of Il6 and Tnf. Fingolimod also exerted an anxiolytic effect in T2DM. Conclusions: Results indicate an important role of S1PR modulation in T2DM. Moreover, fingolimod affected mRNA levels of proteins engaged in glucose metabolism/insulin signaling and improved the behavior of diabetic mice. Full article

Type 2 diabetes mellitus (T2DM) is a chronic disease that has become a serious health problem worldwide. Moreover, increased systemic and cerebrovascular inflammation is one of the major pathophysiological features of T2DM, and a growing body of evidence emphasizes T2DM with memory and executive function decline. Bioactive sphingolipids regulate a cell’s survival, inflammatory response, as well as glucose and insulin signaling/metabolism. Moreover, current research on the role of sphingosine kinases (SPHKs) and sphingosine-1-phosphate receptors (S1PRs) in T2DM is not fully understood, and the results obtained often differ. The aim of the present study was to evaluate the effect of metformin (anti-diabetic agent, MET) on the brain’s sphingosine-1-phosphate-related signaling and ultrastructure in diabetic mice. Our results revealed elevated mRNA levels of genes encoding sphingosine kinase 2 (SPHK2) and sphingosine-1-phosphate receptor 3 (S1PR3), which was accompanied by downregulation of sphingosine-1-phosphate receptor 1 (S1PR1) in the hippocampus of diabetic mice. Simultaneously, upregulation of genes encoding pro-inflammatory cytokines interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) was observed. Administration of MET significantly reversed changes in mRNA levels in the hippocampus and reduced Sphk2, Il6, and Tnf, with concomitant upregulation of S1pr1 gene expression. Ultrastructural analysis of diabetic mice hippocampus revealed morphological alterations in neurons, neuropil, and capillaries that were manifested as mitochondria swelling, blurred synaptic structure, and thickened basal membrane of capillaries. The use of MET partially reversed those changes. Our research emphasizes the important role of insulin sensitivity modulation by metformin in the regulation of SPHKs and S1PRs and inflammatory gene expression in a murine model of T2DM. Full article

Background/Objectives: The interaction between brain-metastasizing melanoma cells and surrounding microglia shapes the immune tumor microenvironment and influences tumor progression. Gene expression analysis revealed that sphingosine-1-phosphate receptor 1 (S1PR1), encoding the S1P1 receptor, is upregulated in microglia upon interaction with melanoma cells. Here, we investigated the functions of S1P1 in microglia and its contribution to melanoma–microglia crosstalk. Methods: We examined the effects of S1P1 inhibition on microglia and four brain-metastasizing human melanoma cell lines in monocultures and co-cultures using the selective S1P1 antagonist NIBR0213 and S1PR1 gene knockdown. Results: We found that melanoma-secreted IL-6 upregulated S1PR1 expression in microglia. S1P1 inhibition increased expression of CD32, CD150, and CD163 in microglia; however, CD150 and CD163 upregulation was abolished in the presence of melanoma cells. S1P1 inhibition downregulated immunosuppressive and anti-inflammatory factors in microglia, including CD274, SOCS3, TGFBR1, TGFBR2, and JunB, promoting a pro-inflammatory phenotype. It also reduced viability of both melanoma and microglia cells, inducing apoptosis in melanoma-associated microglia, possibly via downregulation of CH25H, an upstream regulator of SREBPs. In co-cultures, melanoma cells were more sensitive than microglia to NIBR0213-induced growth arrest. In 3D spheroid cultures, NIBR0213 delayed melanoma–microglia aggregation. Combined treatment with the BRAF inhibitor Vemurafenib and NIBR0213 enhanced Vemurafenib efficacy in three of four melanoma lines. Conclusions: S1P1 contributes to the immunosuppressive phenotype of microglia. Inhibiting the S1P/S1P1 axis impairs viability and crosstalk between melanoma cells and tumor-activated microglia, offering a potential therapeutic strategy for melanoma brain metastases. Full article

Sphingosine 1 phosphate receptor (S1PR) modulators are the latest drug class to have received approval for the treatment of ulcerative colitis, and have brought a new mechanism of action to this landscape. They target immune cell trafficking, specifically the egress of lymphocytes from lymph nodes to the bloodstream, and have proven to be an efficacious and safe anti-inflammatory mechanism. This narrative review aims to distil the key trial data on the efficacy and safety of ozanimod and etrasimod, the two S1PR modulators currently licensed for use in UC. We discuss the higher response rates in the advanced therapy naive versus exposed subgroups. We summarise their safety profiles, taking into consideration open label extension data. Finally, we consider where this class of drugs may be best placed in the treatment landscape and also provide a practical guide for their use in clinical practice. Full article

2-arachnadoyl glycerol (2-AG) is one of the most common endocannabinoid molecules with anti-proliferative, cytotoxic, and pro-proliferative effects on different types of tumors. Typically, it induces cell death via cannabinoid receptor 1/2 (CB1/CB2)-linked ceramide production. In breast cancer, ceramide is counterbalanced by the sphingosine-1-phosphate, and thus the mechanisms of 2-AG influence on proliferation are poorly understood. We evaluated the mechanism of the anti-proliferative action by 2-AG and the influence of lysophaosphatidylinositol (LPI) on it in six human breast cancer cell lines of different tumor degree (MCF-10A, MCF-7, BT-474, BT-20, SK-BR-3, and MDA-MB-231) using resazurin test, inhibitor, blocker, and anti-oxidant analysis, and siRNA interference. To avoid acyl migration in 2-AG, we replaced it with the analog 2-arachidonoyl-1,3-difluoropropanol (2-ADFP) newly synthesized by us. Using a molecular docking approach, we showed that at the CB2 receptor, 2-ADFP and 2-AG were very close to each other. However, 2-ADFP demonstrated a stronger affinity towards CB1 in the antagonist-bound conformation. 2-ADFP was anti-proliferative in all the cell lines tested. The toxicity of 2-ADFP was enhanced by LPI. 2-ADFP activity was reduced or prevented by the CB2 and vanilloid receptor 1 (TRPV1) blockers, inositol triphosphate receptor, CREB, and cyclooxygenase 2 inhibitor, and by anti-oxidant addition. Together with the literature data, these results indicate CB2- and TRPV1-dependent COX-2 induction with concomitant cell death induction by the oxidized molecule’s metabolites. Full article

Background: The aim of our study was to determine the role of sphingolipids, which control proliferation and apoptosis, in the placenta of pregnant women with pregnancy-associated breast cancer (PABC) after chemotherapy compared with healthy patients. Methods: We analyzed (by the PCR method) the gene expression of key sphingolipid metabolism enzymes (sphingomyelinases (SMPD1 and SMPD3), acid ceramidase (ASAH1), ceramide synthases (CERS 1–6), sphingosine kinase1 (SPHK1), sphingosine-1-phosphate lyase 1 (SGPL1), and sphingosine-1-phosphate receptors (S1PR1, S1PR2, and S1PR3)) and the content of subspecies of ceramides, sphingosine, and sphingosine-1-phosphate in seven patients with PABC after chemotherapy and eight healthy pregnant women as a control group. Results: We found a significant increase in the expression of genes of acid ceramidase (ASAH1), sphingosine-1-phosphate lyase 1 (SGPL1), sphingosine kinase (SPHK1), and ceramide synthases (CERS 1-3, 5, 6) in the samples of patients with PABC during their treatment with cytostatic chemotherapy. The increase in the expression of the enzymes’ genes was not accompanied by changes in the content of the studied sphingolipids. Such significant changes in the expression of genes controlling the level of CER, sphingosine, and S1P may indicate their ability to initiate the metabolism of pro-apoptotic and anti-apoptotic sphingolipids in the placenta of pregnant women with cancer undergoing chemotherapy in order to maintain levels typical of the placenta of healthy women. Conclusions: Our results may indicate the promising mechanism of placenta protection during chemotherapy for pregnant women with breast cancer and, consequently, of the newborn. This protective effect of the placenta and especially for the newborn has been discovered for the first time and requires more careful study. Full article

Glycolipid metabolic disorders (GLMDs) are various metabolic disorders resulting from dysregulation in glycolipid levels, consequently leading to an increased risk of obesity, diabetes, liver dysfunction, neuromuscular complications, and cardiorenal vascular diseases (CRVDs). In patients with GLMDs, excess caloric intake and a lack of physical activity may contribute to oxidative stress (OxS) and systemic inflammation. This study aimed to review the connection between GLMD, OxS, metainflammation, and the onset of CRVD. GLMD is due to various metabolic disorders causing dysfunction in the synthesis, breakdown, and absorption of glucose and lipids in the body, resulting in excessive ectopic accumulation of these molecules. This is mainly due to neuroendocrine dysregulation, insulin resistance, OxS, and metainflammation. In GLMD, many inflammatory markers and defense cells play a vital role in related tissues and organs, such as blood vessels, pancreatic islets, the liver, muscle, the kidneys, and adipocytes, promoting inflammatory lesions that affect various interconnected organs through their signaling pathways. Advanced glycation end products, ATP-binding cassette transporter 1, Glucagon-like peptide-1, Toll-like receptor-4, and sphingosine-1-phosphate (S1P) play a crucial role in GLMD since they are related to glucolipid metabolism. The consequences of this is system organ damage and increased morbidity and mortality. Full article

Human corneal fibrosis can lead to opacity and ultimately partial or complete vision loss. Currently, corneal transplantation is the only treatment for severe corneal fibrosis and comes with the risk of rejection and donor shortages. Sphingolipids (SPLs) are known to modulate fibrosis in various tissues and organs, including the cornea. We previously reported that SPLs are tightly related to both, transforming growth factor beta (TGF-β) signaling and corneal fibrogenesis. The aim of this study was to investigate the effects of sphingosine-1-phosphate (S1P) and S1P inhibition on specific TGF-β and SPL family members in corneal fibrosis. Healthy human corneal fibroblasts (HCFs) were isolated and cultured in EMEM + FBS + VitC (construct medium) on 3D transwells for 4 weeks. The following treatments were prepared in a construct medium: 0.1 ng/mL TGF-β1 (β1), 1 μM sphingosine-1-phosphate (S1P), and 5 μM Sphingosine kinase inhibitor 2 (I₂). Five groups were tested: (1) control (no treatment); rescue groups; (2) β1/S1P; (3) β1/I₂; prevention groups; (4) S1P/β1; and (5) I₂/β1. Each treatment was administered for 2 weeks with one treatment and switched to another for 2 weeks. Using Western blot analysis, the 3D constructs were examined for the expression of fibrotic markers, SPL, and TGF-β signaling pathway members. Scratch assays from 2D cultures were also utilized to evaluate cell migration We observed reduced fibrotic expression and inactivation of latent TGF-β binding proteins (LTBPs), TGF-β receptors, Suppressor of Mothers Against Decapentaplegic homologs (SMADs), and SPL signaling following treatment with I₂ prevention and rescue compared to S1P prevention and rescue, respectively. Furthermore, we observed increased cell migration following stimulation with I₂ prevention and rescue groups, with decreased cell migration following stimulation with S1P prevention and rescue groups after 12 h and 18 h post-scratch. We have demonstrated that I₂ treatment reduced fibrosis and modulated the inactivation of LTBPs, TGF-β receptors, SPLs, and the canonical downstream SMAD pathway. Further investigations are warranted in order to fully uncover the potential of utilizing SphK I₂ as a novel therapy for corneal fibrosis. Full article

The deterioration of osteoblast-led bone formation and the upregulation of osteoclast-regulated bone resorption are the primary causes of bone diseases, including osteoporosis. Numerous circulating factors play a role in bone homeostasis by regulating osteoblast and osteoclast activity, including the sphingolipid—sphingosine-1-phosphate (S1P). However, to date no comprehensive studies have investigated the impact of S1P activity on human and murine osteoblasts and osteoclasts. We observed species-specific responses to S1P in both osteoblasts and osteoclasts, where S1P stimulated human osteoblast mineralisation and reduced human pre-osteoclast differentiation and mineral resorption, thereby favouring bone formation. The opposite was true for murine osteoblasts and osteoclasts, resulting in more mineral resorption and less mineral deposition. Species-specific differences in osteoblast responses to S1P were potentially explained by differential expression of S1P receptor 1. By contrast, human and murine osteoclasts expressed comparable levels of S1P receptors but showed differential expression patterns of the two sphingosine kinase enzymes responsible for S1P production. Ultimately, we reveal that murine models may not accurately represent how human bone cells will respond to S1P, and thus are not a suitable model for exploring S1P physiology or potential therapeutic agents. Full article

Krabbe’s disease (KD) is caused by mutations in the lysosomal enzyme galactocerebrosidase and is associated with psychosine toxicity. The sphingosine 1-phosphate receptor (S1PR) agonist fingolimod (FTY720) attenuates psychosine-induced cell death of human astrocytes, demyelination in cerebellar slices, as well as demyelination in the central nervous system of twitcher mice. Psychosine also accumulates in the peripheral nervous system in twitcher mice; however, effects of fingolimod on this peripheral myelin have not been examined. The aim of this study was to investigate the effects of fingolimod administration on peripheral and central markers of myelination. Here, we report that fingolimod administration (1 mg/kg/day) from postnatal day 5 (PND) onwards did not alter peripheral demyelination in the sciatic nerve of twitcher mice, despite significantly reducing myelin debris, glial reactivity, and neuronal damage in the cerebellum. We also find fingolimod administration improves twitching and mobility scores in twitcher mice. Importantly, we find that fingolimod significantly increases the lifespan of twitcher mice by approximately 5 days. These findings suggest differential effects of fingolimod on peripheral and central neuropathy in twitcher mice, which may explain its modest efficacy on behavior and lifespan. Full article