Topographical Mapping of Isoform-Selectivity Determinants for J-Channel-Binding Inhibitors of Sphingosine Kinases 1 and 2

Discovery and biological evaluation of biaryl acetamide derivatives as selective and in vivo active sphingosine kinase-2 inhibitors

Sphingosine kinase 2 (SphK2) has emerged as a promising target for cancer therapy due to its critical role in tumor growth. However, the lack of potent and selective inhibitors has hindered its clinical application. Herein, we report the design and synthesis of a series of novel SphK2 inhibitors, culminating in the identification of compound 12q as a highly selective and potent inhibitor of SphK2. Molecular dynamics simulations suggest that the incorporation of larger substitution groups facilitates a more effective occupation of the binding site, thereby stabilizing the complex. Compared to the widely used inhibitor ABC294640, compound 12q exhibits superior anti-proliferative activity against various cancer cells, inducing G2 phase arrest and apoptosis in liver cancer cells HepG2. Notably, 12q inhibited migration and colony formation in HepG2 and altered intracellular sphingolipid content. Moreover, intraperitoneal administration of 12q in mice resulted in decreased levels of S1P. 12q provides a valuable tool compound for exploring the therapeutic potential of targeting SphK2 in cancer.

Second generation of pyrimidin-quinolone hybrids obtained from virtual screening acting as sphingosine kinase 1 inhibitors and potential anticancer agents

We report here the virtual screening design, synthesis and activity of eight new inhibitors of SphK1. For this study we used a pre-trained Graph Convolutional Network (GCN) combined with docking calculations. This exploratory analysis proposed nine compounds from which eight displayed significant inhibitory effect against sphingosine kinase 1 (SphK1) demonstrating a high level of efficacy for this approach. Four of these compounds also displayed anticancer activity against different tumor cell lines, and three of them (5), (6) and (7) have shown a wide inhibitory action against many of the cancer cell line tested, with GI50 below 5 µM, being (5) the most promising with TGI below 10 µM for the half of cell lines. Our results suggest that the three most promising compounds reported here are the pyrimidine-quinolone hybrids (1) and (6) linked by p-aminophenylsulfanyl and o-aminophenol fragments respectively, and (8) without such aryl linker. We also performed an exhaustive study about the molecular interactions that stabilize the different ligands at the binding site of SphK1. This molecular modeling analysis was carried out by using combined techniques: docking calculations, MD simulations and QTAIM analysis. In this study we also included PF543, as reference compound, in order to better understand the molecular behavior of these ligands at the binding site of SphK1.These results provide useful information for the design of new inhibitors of SphK1 possessing these structural scaffolds.

Design, synthesis, antitumor activity, and molecular dynamics simulations of novel sphingosine kinase 2 inhibitors

Targeting sphingosine kinase 2 (SphK2) has become a novel strategy for the treatment of cancer. However, potent and selective SphK2 inhibitors are rare. In our work, a series of novel SphK2 inhibitors were innovatively designed, synthesized and screened. Compound 12e showed the best inhibitory activity. Molecular dynamics simulations were carried out to analyze the detailed interactions between the SphK2 and its inhibitors. Moreover, 12e exhibited anti-proliferative activity in various cancer cells, and inhibited the migration of human breast cancer cells MCF-7.

The Expression and Clinical Significance of Sphingosine Kinase 1 and Vascular Endothelial Growth Factor in Endometrial Carcinoma

The aim of the study is to investigate the expression of sphingosine kinase 1 (SPHK1) and vascular endothelial growth factor (VEGF) in patients with endometrial carcinoma and its clinical significance. The tissues of 86 cases of patients with endometrial carcinoma and 54 cases of patients with endometrial atypical hyperplasia were collected. The expression of SPHK1 and VEGF in the tissue was detected by immunohistochemistry. The expression of SPHK1 in patients with endometrial carcinoma was compared with the clinicopathological data. Results. 69 cases (82.1%) of endometrial carcinoma were positive for SPHK1, which was higher than 2 cases (3.7%) of endometrial atypical hyperplasia (P < 0.05). The VEGF expression in 54 patients (62.8%) with endometrial carcinoma was higher than that in 12 patients with endometrial atypical hyperplasia (22.2%) (P < 0.05). There was a positive correlation between SPHK1 and VEGF expressions in endometrial carcinoma (c = 0.595). The expression of SPHK1 in endometrial cancer patients was different in different pathological types, FIGO stages, lymph node metastasis, ER, and PR positive or not, and the difference between the two groups was significant (P < 0.05). There was no difference in age, degree of differentiation, and depth of myometrial infiltration (P < 0.05). The expression of SPHK1 in patients with endometrial carcinoma is increased, which is helpful for early detection of patients with endometrial carcinoma, and may play a synergistic role with VEGF in the pathogenesis and development of endometrial carcinoma.

Sphk1 and Sphk2 Differentially Regulate Erythropoietin Synthesis in Mouse Renal Interstitial Fibroblast-like Cells

Erythropoietin (Epo) is a crucial hormone regulating red blood cell number and consequently the hematocrit. Epo is mainly produced in the kidney by interstitial fibroblast-like cells. Previously, we have shown that in cultures of the immortalized mouse renal fibroblast-like cell line FAIK F3-5, sphingosine 1-phosphate (S1P), by activating S1P₁ and S1P₃ receptors, can stabilize hypoxia-inducible factor (HIF)-2α and upregulate Epo mRNA and protein synthesis. In this study, we have addressed the role of intracellular iS1P derived from sphingosine kinases (Sphk) 1 and 2 on Epo synthesis in F3-5 cells and in mouse primary cultures of renal fibroblasts. We show that stable knockdown of Sphk2 in F3-5 cells increases HIF-2α protein and Epo mRNA and protein levels, while Sphk1 knockdown leads to a reduction of hypoxia-stimulated HIF-2α and Epo protein. A similar effect was obtained using primary cultures of renal fibroblasts isolated from wildtype mice, Sphk1−/−, or Sphk2−/− mice. Furthermore, selective Sphk2 inhibitors mimicked the effect of genetic Sphk2 depletion and also upregulated HIF-2α and Epo protein levels. The combined blockade of Sphk1 and Sphk2, using Sphk2−/− renal fibroblasts treated with the Sphk1 inhibitor PF543, resulted in reduced HIF-2α and Epo compared to the untreated Sphk2−/− cells. Exogenous sphingosine (Sph) enhanced HIF-2α and Epo, and this was abolished by the combined treatment with the selective S1P₁ and S1P₃ antagonists NIBR-0213 and TY52156, suggesting that Sph was taken up by cells and converted to iS1P and exported to then act in an autocrine manner through S1P₁ and S1P₃. The upregulation of HIF-2α and Epo synthesis by Sphk2 knockdown was confirmed in the human hepatoma cell line Hep3B, which is well-established to upregulate Epo production under hypoxia. In summary, these data show that sphingolipids have diverse effects on Epo synthesis. While accumulation of intracellular Sph reduces Epo synthesis, iS1P will be exported to act through S1P₁₊₃ to enhance Epo synthesis. Furthermore, these data suggest that selective inhibition of Sphk2 is an attractive new option to enhance Epo synthesis and thereby to reduce anemia development in chronic kidney disease.

Synthesis of PP2A-Activating PF-543 Derivatives and Investigation of Their Inhibitory Effects on Pancreatic Cancer Cells

Sphingosine kinase (SK) is involved in the growth of cells, including cancer cells. However, which of its two isotypes—SK1 and SK2—is more favorable for cancer growth remains unclear. Although PF-543 strongly and selectively inhibits SK1, its anticancer effect is not high, and the underlying reason remains difficult to explain. We previously determined that the tail group of PF-543 is responsible for its low metabolic stability (MS). In this study, compounds containing aromatic or aliphatic tails in the triazole group were synthesized, and changes in the SK-inhibitory effect and anticancer activity of PF-543 were assessed using pancreatic cancer cells. The compounds with aliphatic tails showed high inhibitory effects on pancreatic cancer cells but slightly lower selectivity for SK1. A compound with an introduced aliphatic tail activated protein phosphatase 2A (PP2A), showing an effect similar to that of FTY720. Molecular docking analysis revealed that the PP2A-binding form of this newly synthesized compound was different from that noted in the case of FTY720. This compound also improved the MS of PF-543. These results indicate that the tail structure of PF-543 influences MS.

Novel Sphingosine Kinase 1 Inhibitor Suppresses Growth of Solid Tumor and Inhibits the Lung Metastasis of Triple-Negative Breast Cancer

Targeting sphingosine kinase 1 (SphK1) has become a novel strategy for the treatment of inflammatory bowel disease and cancer via the SphK1/S1P signaling pathway. However, exploration of SphK1 inhibitor therapeutic applications has been hampered by the poor pharmacokinetic properties of these SphK1 inhibitors. Herein, we report the structural optimization and structure-activity relationship studies of a series of novel SphK1 inhibitors. The novel compound 28 selectively inhibits SphK1 and exhibits higher anti-proliferative activity compared to the positive compound PF-543 in various cancer cells, which is associated with the induction of G0/G1 phase arrest and apoptosis; besides, it could also inhibit the cell migration. Further, compound 28 can suppress in vivo growth of both colon tumor and triple-negative breast tumor and inhibits the lung metastasis of triple-negative breast cancer with higher potency compared with that of PF-543. Collectively, compound 28 represents a promising lead compound for the treatment of solid tumor and the metastasis.

Interleukin-7 receptor α mutational activation can initiate precursor B-cell acute lymphoblastic leukemia

Interleukin-7 receptor α (encoded by IL7R) is essential for lymphoid development. Whether acute lymphoblastic leukemia (ALL)-related IL7R gain-of-function mutations can trigger leukemogenesis remains unclear. Here, we demonstrate that lymphoid-restricted mutant IL7R, expressed at physiological levels in conditional knock-in mice, establishes a pre-leukemic stage in which B-cell precursors display self-renewal ability, initiating leukemia resembling PAX5 P80R or Ph-like human B-ALL. Full transformation associates with transcriptional upregulation of oncogenes such as Myc or Bcl2, downregulation of tumor suppressors such as Ikzf1 or Arid2, and major IL-7R signaling upregulation (involving JAK/STAT5 and PI3K/mTOR), required for leukemia cell viability. Accordingly, maximal signaling drives full penetrance and early leukemia onset in homozygous IL7R mutant animals. Notably, we identify 2 transcriptional subgroups in mouse and human Ph-like ALL, and show that dactolisib and sphingosine-kinase inhibitors are potential treatment avenues for IL-7R-related cases. Our model, a resource to explore the pathophysiology and therapeutic vulnerabilities of B-ALL, demonstrates that IL7R can initiate this malignancy.

Synthesis of PF-543 Derivatives Using Simple Synthetic Methods and Their Biological Effect Analysis for the Development of Anticolorectal Cancer Agents

Background:

Sphingolipids, even in extremely low doses, regulate various physiological functions. Particularly, immune and cancer cells might be controlled by changes in the sphingosine- 1-phosphate (S1P) levels, and S1P has been studied for a long time as a major target for new drug development. Sphingosine kinase (SK) phosphorylates sphingosine to produce S1P. An increase in the S1P levels promotes the growth of cancer cells. SK has 2 isoforms, SK1 and SK2, both of which are involved in the growth of cancer cells.

Objective:

PF-543 has been developed as an SK1 inhibitor and has a non-lipid structure that differs from those of general SK inhibitors. While PF-543 has a potent SK1 inhibitory effect, and has low anticancer activity in some types of cancer cells. Therefore, the development of other PF-543 derivatives is needed.

Methods:

We designed a structurally simplified derivative of PF-543. To primarily demonstrate that the designed structure was biologically active, 8 derivatives were synthesized by a 2-step method using the commercial starting material, and their biological activities were evaluated.

Results:

The SK1-inhibitory effects of the synthesized derivatives were not higher than that of PF- 543. However, the anticancer activity and apoptotic effect of the derivatives were similar to those of PF-543, despite their fabrication from a simple modification of the PF-543 structure. In a docking study, the derivatives were found to bind SK1 in a form similar to PF-543.

Conclusion:

Our analogs, which are similar to PF-543, showed comparable anticancer activity, indicating that the synthesized derivatives are structurally more efficient for anticancer activity than PF-543. Therefore, our study provides important information that may be useful for developing new anticancer substances that target SK1.

Critical roles of sphingosine kinase 1 in the regulation of neuroinflammation and neuronal injury after spinal cord injury

Background

The pathological process of traumatic spinal cord injury (SCI) involves excessive activation of microglia leading to the overproduction of proinflammatory cytokines and causing neuronal injury. Sphingosine kinase 1 (Sphk1), a key enzyme responsible for phosphorylating sphingosine into sphingosine-1-phosphate (S1P), plays an important role in mediating inflammation, cell proliferation, survival, and immunity.

Methods

We aim to investigate the mechanism and pathway of the Sphk1-mediated neuroinflammatory response in a rodent model of SCI. Sixty Sprague-Dawley rats were randomly assigned to sham surgery, SCI, or PF543 (a specific Sphk1 inhibitor) groups. Functional outcomes included blinded hindlimb locomotor rating and inclined plane test.

Results

We discovered that Sphk1 is upregulated in injured spinal cord tissue of rats after SCI and is associated with production of S1P and subsequent NF-κB p65 activation. PF543 attenuated p65 activation, reduced inflammatory response, and relieved neuronal damage, leading to improved functional recovery. Western blot analysis confirmed that expression of S1P receptor 3 (S1PR3) and phosphorylation of p38 mitogen-activated protein kinase (p38 MAPK) are activated in microglia of SCI rats and mitigated by PF543. In vitro, we demonstrated that Bay11-7085 suppressed NF-κB p65 and inhibited amplification of the inflammation cascade by S1P, reducing the release of proinflammatory TNF-α. We further confirmed that phosphorylation of p38 MAPK and activation of NF-κB p65 is inhibited by PF543 and CAY10444. p38 MAPK phosphorylation and NF-κB p65 activation were enhanced by exogenous S1P and inhibited by the specific inhibitor SB204580, ultimately indicating that the S1P/S1PR3/p38 MAPK pathway contributes to the NF-κB p65 inflammatory response.

Conclusion

Our results demonstrate a critical role of Sphk1 in the post-traumatic SCI inflammatory cascade and present the Sphk1/S1P/S1PR3 axis as a potential target for therapeutic intervention to control neuroinflammation, relieve neuronal damage, and improve functional outcomes in SCI.

Rational design of SphK inhibitors using crystal structures aided by computer

Sphingosine kinases (SphKs) are lipid kinases that catalyze the phosphorylation of sphingosine (Sph) to sphingosine-1-phosphate (S1P). As a bioactive lipid, S1P plays a role outside and inside the cell to regulate biological processes. The overexpression of SphKs is related to a variety of pathophysiological conditions. Targeting the S1P signaling pathway is a potential treatment strategy for many diseases. SphKs are key kinases of the S1P signaling pathway. The SphK family includes two isoforms: SphK1 and SphK2. Determination of the co-crystal structure of SphK1 with various inhibitors has laid a solid foundation for the development of small molecule inhibitors targeting SphKs. This paper reviews the differences and connections between the two isoforms and the structure of SphK1 crystals, especially the structure of its Sph "J-shaped" channel binding site. This review also summarizes the recent development of SphK1 and SphK2 selective inhibitors and the exploration of the unresolved SphK2 structure.

Probing the substitution pattern of indole-based scaffold reveals potent and selective sphingosine kinase 2 inhibitors

Elevated levels of sphingosine 1-phosphate (S1P) and increased expression of sphingosine kinase isoforms (SphK1 and SphK2) have been implicated in a variety of disease states including cancer, inflammation, and autoimmunity. Consequently, the S1P signaling axis has become an attractive target for drug discovery. Selective inhibition of either SphK1 or SphK2 has been demonstrated to be effective in modulating S1P levels in animal models. While SphK1 inhibitors have received much attention, the development of potent and selective SphK2 inhibitors are emerging. Previously, our group reported a SphK2 naphthalene-based selective inhibitor, SLC5081308, which displays approximately 7-fold selectivity for hSphK2 over hSphK1 and has a SphK2 K_i value of 1.0 μM. To improve SphK2 potency and selectivity, we designed, synthesized, and evaluated a series of indole-based compounds derived from SLC5081308. After investigating substitution patterns around the indole ring, we discovered that 1,5-disubstitution promoted optimal binding in the SphK2 substrate binding site and subsequent inhibition of enzymatic activity. Our studies led to the identification of SLC5101465 (6r, SphK2 K_i = 90 nM, >110 fold selective for SphK2 over SphK1). Molecular modeling studies revealed key nonpolar interactions with Val308, Phe548, His556, and Cys533 and hydrogen bonds with both Asp211 and Asp308 as responsible for the high SphK2 inhibition and selectivity.

Lipophilic tail modifications of 2-(hydroxymethyl)pyrrolidine scaffold reveal dual sphingosine kinase 1 and 2 inhibitors

The sphingosine 1-phosphate (S1P) signaling pathway is an attractive target for pharmacological manipulation due to its involvement in cancer progression and immune cell chemotaxis. The synthesis of S1P is catalyzed by the action of sphingosine kinase 1 or 2 (SphK1 or SphK2) on sphingosine and ATP. While potent and selective inhibitors of SphK1 or SphK2 have been reported, development of potent dual SphK1/SphK2 inhibitors are still needed. Towards this end, we report the structure-activity relationship profiling of 2-(hydroxymethyl)pyrrolidine-based inhibitors with 22d being the most potent dual SphK1/SphK2 inhibitor (SphK1 K_i = 0.679 μM, SphK2 K_i = 0.951 μM) reported in this series. 22d inhibited the growth of engineered Saccharomyces cerevisiae and decreased S1P levels in histiocytic lymphoma myeloid cell line (U937 cells), demonstrating inhibition of SphK1 and 2 in vitro. Molecular modeling studies of 22d docked inside the Sph binding pocket of both SphK1 and SphK2 indicate essential hydrogen bond between the 2-(hydroxymethyl)pyrrolidine head to interact with aspartic acid and serine residues near the ATP binding pocket, which provide the basis for dual inhibition. In addition, the dodecyl tail adopts a "J-shape" conformation found in crystal structure of sphingosine bound to SphK1. Collectively, these studies provide insight into the intermolecular interactions in the SphK1 and 2 active sites to achieve maximal dual inhibitory activity.

A Novel Selective Sphingosine Kinase 2 Inhibitor, HWG-35D, Ameliorates the Severity of Imiquimod-Induced Psoriasis Model by Blocking Th17 Differentiation of Naïve CD4 T Lymphocytes

Sphingosine kinases (SK) catalyze the phosphorylation of sphingosine to generate sphingosine-1-phosphate. Two isoforms of SK (SK1 and SK2) exist in mammals. Previously, we showed the beneficial effects of SK2 inhibition, using ABC294640, in a psoriasis mouse model. However, ABC294640 also induces the degradation of SK1 and dihydroceramide desaturase 1 (DES1). Considering these additional effects of ABC294640, we re-examined the efficacy of SK2 inhibition in an IMQ-induced psoriasis mouse model using a novel SK2 inhibitor, HWG-35D, which exhibits nM potency and 100-fold selectivity for SK2 over SK1. Topical application of HWG-35D ameliorated IMQ-induced skin lesions and normalized the serum interleukin-17A levels elevated by IMQ. Application of HWG-35D also decreased skin mRNA levels of interleukin-17A, K6 and K16 genes induced by IMQ. Consistent with the previous data using ABC294640, HWG-35D also blocked T helper type 17 differentiation of naïve CD4⁺ T cells with concomitant reduction of SOCS1. Importantly, HWG-35D did not affect SK1 or DES1 expression levels. These results reaffirm an important role of SK2 in the T helper type 17 response and suggest that highly selective and potent SK2 inhibitors such as HWG-35D might be of therapeutic use for the treatment of psoriasis.

Structure-function analysis of lipid substrates and inhibitors of sphingosine kinases

The sphingosine kinases, SK1 and SK2, catalyse the formation of the bioactive signalling lipid, sphingosine 1-phosphate (S1P), from sphingosine. SK1 and SK2 differ in their subcellular localisation, trafficking and regulation, but the isoforms are also distinct in their selectivity toward naturally occurring and synthetic ligands as substrates and inhibitors. To date, only the structure of SK1 has been determined, and a structural basis for selectivity differences in substrate handling by SK2 has yet to be established. Here we present a structural rationale, based on homology modelling and ligand docking, to account for the capacity of SK2, but not SK1, to efficiently process the pharmacologically active substances, fingolimod (FTY720) and safingol, as substrates. We propose that two key residue differences in hSK2 (Ser305/Thr584 in place of Ala175/Ala339 in hSK1) facilitate conformational switching in the lipid head group anchor residue, Asp308 (corresponding to Asp178 in hSK1), to accommodate substrate diversity for SK2. Our analysis accounts for the contrasting behaviour of fingolimod and safingol as non-turnover inhibitors of SK1, but substrates for SK2, and the observed stereoselectivity for phosphorylation of the pro-S hydroxymethyl group of fingolimod to generate (S)-FTY720-P in vivo. We also rationalise why methylation of the pro-R hydroxymethyl of FTY720 switches the behaviour of the resulting compound, (R)-FTY720 methyl ether (ROMe), to SK2-selective inhibition. Whilst the pharmacological significance of (S)-FTY720-P is firmly established, as the active principle of fingolimod in treating relapsing-remitting multiple sclerosis, the potential importance of SK-mediated phosphorylation of other substrates, such as safingol and non-canonical naturally occuring substrates such as (4E,nZ)-sphingadienes, is less widely appreciated. Thus, the contribution of SK2-derived safingol 1-phosphate to the anti-cancer activity of safingol should be considered. Similarly, the biological role of sphingadiene 1-phosphates derived from plant-based dietary sphingadienes, which we also show here are substrates for both SK1 and SK2, merits investigation.

Recent advances in the role of sphingosine 1-phosphate in cancer

Sphingosine 1-phosphate (S1P) is a bioactive lipid that binds to a family of G protein-coupled receptors (S1P_1-5 ) and intracellular targets, such as HDAC1/2, that are functional in normal and pathophysiologic cell biology. There is a significant role for sphingosine 1-phosphate in cancer underpinning the so-called hallmarks, such as transformation and replicative immortality. In this review, we survey the most recent developments concerning the role of sphingosine 1-phosphate receptors, sphingosine kinase and S1P lyase in cancer and the prognostic indications of these receptors and enzymes in terms of disease-specific survival and recurrence. We also provide evidence for identification of new therapeutic approaches targeting sphingosine 1-phosphate to prevent neovascularisation, to revert aggressive and drug-resistant cancers to more amenable forms sensitive to chemotherapy, and to induce cytotoxicity in cancer cells. Finally, we briefly describe current advances in the development of isoform-specific inhibitors of sphingosine kinases for potential use in the treatment of various cancers, where these enzymes have a predominant role. This review will therefore highlight sphingosine 1-phosphate signalling as a promising translational target for precision medicine in stratified cancer patients.

Glycans Meet Sphingolipids: Structure-Based Design of Glycan Containing Analogues of a Sphingosine Kinase Inhibitor

Sphingosine 1-phosphate (S1P) is a bioactive lipid mediator associated with diverse homeostatic and signaling roles. Enhanced biosynthesis of S1P, mediated by the sphingosine kinase isozymes (SK1 and SK2), is implicated in several pathophysiological conditions and diseases, including skeletal muscle fibrosis, inflammation, multiple sclerosis, and cancer. Therefore, therapeutic approaches that control S1P production have focused on the development of SK1/2 inhibitors. In this framework, we designed a series of natural monosaccharide-based compounds to enhance anchoring of the known SK1 inhibitor PF-543 at the polar head of the J-shaped substrate-binding channel. Herein, we describe the structure-based design and synthesis of new glycan-containing PF-543 analogues and we demonstrate their efficiency in a TGFβ1-induced pro-fibrotic assay.

Discovery of a Small Side Cavity in Sphingosine Kinase 2 that Enhances Inhibitor Potency and Selectivity

The sphingosine-1-phosphate (S1P) signaling pathway is an attractive drug target due to its involvement in immune cell chemotaxis and vascular integrity. The formation of S1P is catalyzed by sphingosine kinase 1 or 2 (SphK1 or SphK2) from sphingosine (Sph) and ATP. Inhibition of SphK1 and SphK2 to attenuate levels of S1P has been reported to be efficacious in animal models of diseases such as cancer, sickle cell disease, and renal fibrosis. While inhibitors of both SphKs have been reported, improvements in potency and selectivity are still needed. Toward that end, we performed structure-activity relationship profiling of 8 (SLM6031434) and discovered a heretofore unrecognized side cavity that increased inhibitor potency toward SphK2. Interrogating this region revealed that relatively small hydrophobic moieties are preferred, with 10 being the most potent SphK2-selective inhibitor (K_i = 89 nM, 73-fold SphK2-selective) with validated in vivo activity.

Targeting sphingosine kinase 1 for the treatment of pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH), characterized by high morbidity and mortality, is a serious hazard to human life. Until now, the long-term survival of the PAH patients is still suboptimal. Recently, sphingosine kinase 1 (SPHK1) has drawn more and more attention due to its essential role in the pulmonary vasoconstriction, remodeling of pulmonary blood vessels and right cardiac lesions in PAH patients, and this enzyme is regarded as a new target for the treatment of PAH. Here, we discussed the multifarious functions of SPHK1 in PAH physiology and pathogenesis. Moreover, the structural features of SPHK1 and binding modes with different inhibitors were summarized. Finally, recent advances in the medicinal chemistry research of SPHK1 inhibitors are presented.

Meeting Report - The 2019 FEBS special meeting on sphingolipid biology: sphingolipids in physiology and pathology

Sphingolipids are a fundamental class of molecules that are involved in structural, organizational and signaling properties of eukaryotic membranes. Defects in their production or disposal lead to acquired and inherited human diseases. A growing community of scientists has embraced the challenge to dissect different aspects of sphingolipid biology using a variety of approaches, and a substantial part of this community met last May in the beautiful town of Cascais in Portugal. Over 200 scientists from 26 countries animated the conference, held in a 15th century citadel, sharing their data and opinions on the current understanding and future challenges in sphingolipid research. Here, we report some of their contributions to provide the readers with a bird's-eye view of the themes discussed at the meeting.