Binding and carrying role of human serum albumin from various sources to sphingosine-1-phosphate / 中国输血杂志

【Objective】 To investigate the binding and carrying effects of human serum albumin (HSA) from various sources on sphingosine-1-phosphate (S1P). 【Methods】 Utilizing human plasma-derived HSA (pHSA) and recombinant HSA (rHSA) samples as the focal points of our investigation, LC-MS/MS technology was employed to meticulously compare and analyze the disparities in S1P content among the aforementioned samples. Subsequently, under physiological concentration conditions, S1P was directly introduced to HSA samples for loading processing, facilitating a comprehensive comparison of the binding efficacy of HSA from different sources to S1P. Within a serum-free culture setting, HSA samples from various sources were co-cultured with HUVEC cells. The alterations in S1P content within the cell culture supernatant across different treatment groups were meticulously analyzed, allowing for a nuanced comparison of the S1P carry effects exerted by HSA from different sources on cells.The interaction between HSA and S1P molecules from different sources was analyzed and their affinity was calculated using surface plasmon resonance (SPR) technology. Furthermore, leveraging AutoDock Vina software and the Molprophet platform, the molecular docking analysis of HSA and S1P was conducted, aiming to predict the key binding pocket domain of S1P within HSA. 【Results】 All pHSA samples exhibited detectable levels of S1P (ranging from 3.31±0.03 to 30.35±0.07 μg/L), with significant variations observed among pHSA samples from different manufacturers (P<0.001). Conversely, S1P was undetectable in all rHSA samples. Upon load treatment, the binding affinity of HSA from diverse sources to S1P demonstrated significant discrepancies (P<0.001), with rHSA exhibiting approximately double the average S1P loading compared to pHSA (ΔCrHSA=801.75±142.45 μg/L vs ΔCpHSA=461.94±85.73 μg/L; P<0.001, t=5.006). Co-culture treatment outcomes revealed a significant elevation in S1P concentration within the supernatant after 6 hours of co-culture across all HSA sample processing groups with HUVEC cells, while no changes were observed in the supernatant of the blank control group. Notably, significant differences in supernatant S1P concentration were observed among treatment groups at 6 h, 12 h, and 24 h (P<0.001). SPR analysis unveiled a stronger affinity of pHSA for S1P compared to rHSA (KDpHSA-S1P: 2.38E-06, KDrHSA-S1P: 3.72E-06). Molecular docking analysis and binding pocket prediction suggested that the key binding pocket of HSA and S1P may reside in the IB subdomain of the HSA molecule. 【Conclusion】 HSA from various sources exhibits distinct binding and carrying effects on S1P, which appear to be closely associated with the IB subdomain of the HSA molecule.

Effects of alfentanil on myocardial fibrosis in rats with acute myocardial infarction by regulating the SphK1/S1P signaling pathway / 中国药房

OBJECTIVE To explore the effects of alfentanil （ALF） on myocardial fibrosis in rats with acute myocardial infarction （AMI） by regulating sphingosine kinase 1 （SphK1）/sphingosine 1-phosphate （S1P） signaling pathway. METHODS Male SD rats were collected to construct AMI model by the ligation of anterior descending branch of left coronary artery. The successfully modeled rats were randomly divided into AMI model group （Model group）， ALF low-dose group （ALF-L group， 0.25 mg/kg ALF）， ALF high-dose group （ALF-H group， 0.5 mg/kg ALF）， high dose of ALF+SphK1 activator group （ALF-H+K6PC-5 group， 0.5 mg/kg ALF+1 μg/g K6PC-5）. At the same time， a sham operation group （Sham group） was set up to perform only chest opening/closing operations without ligating the anterior descending branch of left coronary artery， with 15 rats in each group. Rats in each drug group were intraperitoneally injected with the corresponding drug solution， once a day， for 4 consecutive weeks. Twelve hours after the last medication， cardiac function indicators [left ventricular systolic pressure （LVSP）， left ventricular ejection fraction （LVEF）， left ventricular systolic diameter （LVSD）， left ventricular fractional shortening （LVFS）] of rats were detected in each group； the condition of myocardial infarction， pathological changes in myocardial tissue， and degree of fibrosis were observed； serum levels of brain natriuretic peptide （BNP） and cardiac troponin Ⅰ （cTnⅠ） in rats were detected. The protein expressions of collagen Ⅰ ， collagen Ⅲ ， matrix metalloproteinase-2 （MMP-2）， SphK1 and S1P were alsodetected in the myocardial tissue of rats. RESULTS Compared with the Sham group， the arrangement of myocardial cells in the Model group was disordered， with a large number of inflammatory cells infiltrating. The levels of LVSP， LVFS and LVEF in the Model group were significantly reduced （P＜0.05）； LVSD level， myocardial infarction area， collagen volume fraction， serum levels of BNP and cTnⅠ， the protein expressions of collagen Ⅰ， collagen Ⅲ， MMP-2， SphK1 and S1P in myocardial tissue were significantly increased or enlarged （P＜0.05）. Compared with the Model group， the pathological changes and degree of fibrosis in the myocardial tissue of rats in each dose group of ALF were improved or relieved， while the quantitative indicators of rats in the ALF-H group were significantly improved and significantly better than those in ALF-L group （P＜0.05）. K6PC-5 could significantly reverse the improvement effect of high-dose ALF on the above quantitative indicators in rats （P＜0.05）. CONCLUSIONS ALF can reduce myocardial fibrosis and improve cardiac function in AMI rats， and the effect may be related to the inhibition of the SphK1/S1P signaling pathway.

Effect of FTY720 on transfusion-related acute lung injury: a preliminary investigation / 中国输血杂志

【Objective】 To investigate the effects and mechanisms of different doses of fingolimod (FTY720) on non-antibody-mediated transfusion-related acute lung injury (TRALI). 【Methods】 A TRALI mouse model was constructed using lipopolysaccharide (LPS) pre-stimulation and platelets (Plt) of different storage days for second strike. The success of the modeling was determined by protein concentration in lung tissue homogenates, myeloperoxidase (MPo) activity, lung wet/dry weight ratio (W/D ratio), lung tissue damage score and pathological sections. Ceramide and sphingosine-1-phosphate (S1P) contents in platelets of different storage days were detected. FTY720 was administered 1 h after LPS injection to investigate the role of FTY720 in TRALI. The expression levels of vascular endothelial cadherin (VE-cadherin) and zonula occludens-1 (ZO-1) were analyzed by WB. 【Results】 Mice infused with stored 5-day Plt (d5Plt group) exhibited typical signs of TRALI, and the differences in lung tissue homogenate protein concentration (6 546.38±409.50) μg/mL, MPO activity (49.38±4.43) U/L, W/D ratio 4.79±0.21, and lung tissue damage score 7.24±0.38 from the rest of the groups were statistically significant (P<0.05). With the increase of platelet storage time, the ceramide content gradually increased and S1P content gradually decreased, and the ratio of the two was imbalanced. d5Plt showed statistically significant differences (P<0.01) in ceramide content (58.37±5.69) μmol/L and S1P content (149.81±4.86) nmol/L from the rest of the groups. After preventive administration of FTY720, 1 mg/kg FTY720 had no significant effect on TRALI mice, whose lung tissue homogenate protein concentration (6 170.26±545.50) μg/mL, MPO activity (45.97±4.79) U/L, W/D ratio 4.88±0.25, and lung tissue damage score 7.92±0.65 were significantly higher than those of the normal and LPS control groups (P<0.01). The low-dose (0.5, 0.2, and 0.1 mg/kg) FTY720 group alleviated lung injury, and its protein concentration, MPO activity, W/D ratio, and lung tissue injury score were significantly lower than those of the d5Plt group (P<0.05). Pathological sections also showed similar results. In terms of endothelial intercellular junction protein expression, the VE-cadherin expression levels in the 1 mg/kg FTY720 group were significantly lower than those in the normal and LPS control groups (P<0.05), and the VE-cadherin and ZO-1 expression levels in the low-dose (0.5, 0.2, and 0.1 mg/kg) FTY720 group were significantly higher than those in the d5Plt group (P<0.05), which tended to be normalized. 【Conclusion】 In this study, a TRALI mouse model was successfully established by one strike of LPS and two strikes of d5Plt. Low doses of FTY720 (0.5, 0.2, 0.1 mg/kg) were protective against TRALI, while high doses of FTY720 (1 mg/kg) may aggravate the symptoms of TRALI. This protective effect may be somewhat dependent on the expression of VE-cadherin and ZO-1.

Effects of S1P/S1PR1 pathway on high glucose induced epithelial-mesenchymal transition of rat renal tubular epithelial cells by regulating ROS/NLRP3 / 中国药理学通报

Aim To explore the effect of S1P/S1PR1 signaling pathway on high glucose(HG)-induced epithelial-mesenchymal transition of rat renal tubular epithelial cells and its possible mechanism. Methods Cells were treated with different concentrations of glucose, and intracellular S1P expression was detected by ELISA and S1PR1 protein expression was detected by Western blot. The cells were divided into normal control group, HG group and HG + siS1PR1 group. The expression of E-cadherin, Vimentin, Fibronectin and Twist mRNA were detected by RT-qPCR and E-cadherin, α-SMA, Vimentin, NLRP3, ASC and NF-κB protein expression were detected by Western blot, and the levels of reactive oxygen species(ROS) were detected by flow cytometry. The cells were divided into normal control group, S1P group and S1P + siS1PR1 group. Vimentin, Snail, α-SMA, NLRP3, ASC and NF-κB protein expressions were detected by Western blot, and ROS levels were measured by fluorescence microscopy. Results ELISA results showed that the content of S1P in cells increased significantly under high glucose stimulation. Western blot results showed that S1PR1 protein expression was significantly higher at 30 mmol · L

S1P/S1P Receptor Pathway: A New Target for Treatment of Inflammatory Bowel Disease / 胃肠病学

The development of targeted oral drugs that can stably treat inflammatory bowel disease (IBD) is still a clinical problem to be solved. In recent years, studies have confirmed that sphingosine⁃1⁃phosphate (S1P)/S1P receptor pathway can regulate lymphocyte homing and immune regulation, inhibit intestinal inflammation, protect intestinal endothelial barrier, and affect intestinal microbial metabolism, which may play a key role in the treatment of IBD. This article reviewed the effect of S1P/S1P receptor pathway on IBD and its potential mechanism.

Platycladi Semen oil ameliorates Aβ_(25-35)-induced brain injury in mice based on network pharmacology and gut microbiota / 中国中药杂志

The present study aimed to investigate the protective effect and underlying mechanism of Platycladi Semen oil(SP) on Aβ_(25-35)-induced brain injury in mice to provide a theoretical basis for the clinical treatment of Alzheimer's disease(AD). Male Kunming(KM) mice were randomly divided into a control group, a model group(brain injection of Aβ_(25-35), 200 μmol·L~(-1), 0.15 μL·g~(-1)), a positive drug group(donepezil, 10 mg·kg~(-1)), and low-and high-dose SP groups(0.5 and 1 mL·kg~(-1)). Learning and memory ability, neuronal damage, levels of Aβ_(1-42)/Aβ_(1-40), p-Tau, related indicators of apoptosis and oxidative stress, and immune cells, and protein and mRNA expression related to the sphingosine kinase 1(SPHK1)/sphingosine-1-phosphate(S1P)/sphingosine-1-phosphate receptor 5(S1PR5) signaling pathway of mice in each group were determined. In addition, compounds in SP were analyzed by gas chromatography-mass spectrometry(GC-MS). The mechanism of SP against AD was investigated by network pharmacology, 16S rDNA gene sequencing for gut microbiota(GM), and molecular docking techniques. The results showed that SP could improve the learning and memory function of Aβ_(25-35)-induced mice, reduce hippocampal neuronal damage, decrease the levels of Aβ_(1-42)/Aβ_(1-40), p-Tau, and indicators related to apoptosis and oxidative stress in the brain, and maintain the homeostasis of immune cells and GM. Network pharmacology and sequencing analysis for GM showed that the therapeutic effect of SP on AD was associated with the sphingolipid signaling pathway. Meanwhile,(Z,Z,Z)-9,12,15-octadecatrienoic acid and(Z,Z)-9,12-octadecadienoic acid, the components with the highest content in SP, showed good binding activity to SPHK1 and S1PR5. Therefore, it is inferred that SP exerts anti-apoptosis and antioxidant effects by regulating GM and inhibiting SPHK1/S1P/S1PR5 pathway, thereby improving brain injury induced by Aβ_(25-35) in mice. Moreover,(Z,Z,Z)-9,12,15-octadecatrienoic acid and(Z,Z)-9,12-octadecadienoic acid may be the material basis for the anti-AD effect of SP.

Effects of Hydroxycamptothecin Liposomes on Myocardial Fibrosis in Heart Failure Rats by Regulating Sphingosine Kinase 1/Sphingosine-1-Phosphate Signaling Pathway / 中山大学学报(医学科学版)

ObjectiveTo investigate the effects of hydroxycamptothecin liposomes （LHCPT） on myocardial fibrosis in rats with heart failure by regulating the sphingosine kinase 1 （SphK1）/sphingosine-1-phosphate （S1P） signaling pathway. MethodsSD rats were divided into control group， model group， hydroxycamptothecin （HCPT） group， LHCPT group， captopril group， and LHCPT+K6PC-5 （SphK1 activator） group， with 12 rats in each group. The heart failure rat models in all groups except the control group were established by intraperitoneal injection of doxorubicin and then the corresponding drugs were given once a day. After four weeks， we applied color Doppler ultrasound to detect left ventricular end systolic diameter （LVESD）， left ventricular end diastolic diameter （LVEDD）， and left ventricular ejection fraction （LVEF） in rats； HE and Masson staining for myocardial pathological damage and myocardial fibrosis in rats， respectively； ELISA method for the levels of tumor necrosis factor-α （TNF-α） and interleukin-6 （IL-6） in rat myocardial tissues； qRT-PCR for the expression of transforming growth factor-β1 （TGF-β1）， type I collagen （Collagen I）， and type Ⅲ collagen （Collagen Ⅲ） in rat myocardial tissues； Western blot for the expression of SphK1 and S1P proteins in rat myocardial tissues. ResultsCompared with the control group， the model group showed severe myocardial pathological damage and myocardial fibrosis， increased LVESD， LVEDD， levels of TNF-α and IL-6， expression of TGF-β1， Collagen I， Collagen Ⅲ， SphK1， S1P and decreased LVEF （P<0.05）. Compared with the model group， the HCPT group， LHCPT group and captopril group showed alleviated myocardial pathological damage and myocardial fibrosis， decreased LVESD， LVEDD， levels of TNF-α and IL-6， expression of TGF-β1， Collagen I， Collagen Ⅲ， SphK1， S1P and increased LVEF （P<0.05）. Compared with the LHCPT group， the LHCPT+K6PC-5 group showed aggravated myocardial pathological damage and myocardial fibrosis， increased LVESD， LVEDD， levels of TNF-α and IL-6， expression of TGF-β1， Collagen I， Collagen Ⅲ， SphK1， S1P and decreased LVEF （P<0.05）. ConclusionLHCPT may inhibit myocardial fibrosis in heart failure rats by inhibiting the SphK1/S1P signaling pathway.

Research progress of S1P signaling pathway in eye diseases / 中华实验眼科杂志

Sphingolipid metabolism is widely involved in the functional regulation of different cells, and also plays an important role in ocular tissues.Sphingosine 1-phosphate (S1P) is the end product of sphingolipid metabolism and has been shown to play an important role in the onset and development of eye diseases.S1P signaling pathway is widely expressed in various ocular cells and is involved in the regulation of cell proliferation, differentiation, migration and apoptosis.S1P activates a variety of signaling pathways by binding to corresponding receptors and thus plays a wide range of physiological and pathological effects in the eye.Recent studies have found that the S1P signaling pathway can not only mediate the normal development of blood vessels and nerves in the eye, maintain the normal structure of the ocular tissues, and participate in the metabolism of lipids in the eye, but also has a close relationship with immune-related inflammatory response, pathological fibrosis, destruction of cell functional barrier and other related pathological changes.This paper mainly reviewed the basic overview of the S1P signaling pathway, its physiological role in the eye, and its role in the pathological changes of anterior and posterior segment diseases, so as to provide new directions and targets for the treatment of eye diseases.

The Role of SPHK￣S1P Axis in Angiogenesis￣related Diseases / 中国生物化学与分子生物学报

Angiogenesis refers to the process of forming new blood vessels based on original blood vessels. Pathological angiogenesis is a sign of a series of diseases such as cancer, cardiovascular diseases, and retinopathy. Sphingosine 1-phosphate (S1P) is a signaling lipid synthesized by sphingosine kinase (SPHK) that exerts its diverse biological and pathophysiological roles through five G protein-coupled receptors (S1PR1-5) and initiates various signaling cascades by activating receptors that affect cell fate, vascular tension, endothelial function and integrity, and lymphocyte transport. The imbalance ofproduction and signal is closely related to pathological processes such as endothelial dysfunction and abnormal angiogenesis. Accumulating evidence suggests that the SPHK-S1P axis plays an important role in angiogenesis, especially in the development of tumors, diabetes retinopathy, atherosclerosis, myocardial infarction and other cardiovascular diseases. Studies on its roles and functions can provide new insights and drug therapeutic targets for the treatment of angiogenesis-related diseases. This review describes the molecular mechanisms by which the SPHK-S1P axis affects endothelial cell and smooth muscle cellproliferation, endothelial cell migration and the formation of lumen by endothelial cells, pericytes and smooth muscle cells through SPHK and S1PR1-5. The review also elaborates how the SPHK-S1P axis affects angiogenesis in tumors, cardiovascular diseases, diabetes and retinopathy through SPHK and S1PR1-5, and aims to provide new therapeutic strategy for related diseases by understanding the molecular mechanism of the SPHK-S1P axis in angiogenesis.

Design and synthesis of selective sphingosine-1-phosphate receptor 1 agonists with increased phosphorylation rates

FTY720 and IMMH002, prodrugs for sphingosine-1-phosphate receptor 1 (S1P) agonists, show inadequate and inconsistent levels of phosphorylation in humans compared to that in rats. In this study, FTY720 or IMMH002 analogues (-) were designed and synthesized with modified head pieces to improve the biotransformation of the prodrugs to the active phosphorylated forms. Target compounds were synthesized a convergent route using the key and optically pure building block , which was first synthesized asymmetrically catalyzed amination. The phosphorylation rates of these analogues in rat or human blood were compared. The new methyl-substituted analogue compound showed higher phosphorylation rates in both rats and humans than the parent compound, whereas compound showed improvements in rats, but not in humans. In pharmacokinetics studies of rats, compounds and both had higher levels of phosphorylation than FTY720 and IMMH002. Thus, our study not only yielded new compounds with therapeutic potential, but also showed species differences between rats and humans in response to the structural modifications, which might be useful for predicting the biotransformation behavior and efficacy of this class of prodrugs in the clinic.

A novel S1P1 modulator IMMH002 ameliorates psoriasis in multiple animal models

Psoriasis is characterized by abnormal proliferation of keratinocytes, as well as infiltration of immune cells into the dermis and epidermis, causing itchy, scaly and erythematous plaques of skin. The understanding of this chronic inflammatory skin disease remains unclear and all available treatments have their limitations currently. Here, we showed that IMMH002, a novel orally active S1P modulator, desensitized peripheral pathogenic lymphocytes to egress signal from secondary lymphoid organs and thymus. Using different psoriasis animal models, we demonstrated that IMMH002 could significantly relieve skin damage as revealed by PASI score and pathological injure evaluation. Mechanistically, IMMH002 regulated CD3 T lymphocytes re-distribution by inducing lymphocytes' homing, thus decreased T lymphocytes allocation in the peripheral blood and skin but increased in the thymus. Our results suggest that the novel S1P agonist, IMMH002, exert extraordinary capacity to rapidly modulate T lymphocytes distribution, representing a promising drug candidate for psoriasis treatment.

Deficiency of Sphingosine-1-Phosphate Receptor 2 (S1P₂) Attenuates Bleomycin-Induced Pulmonary Fibrosis

Sphingosine 1-phosphate (S1P) levels are often found to be elevated in serum, bronchoalveolar lavage, and lung tissue of idiopathic pulmonary fibrosis patients and experimental mouse models. Although the roles of sphingosine kinase 1 and S1P receptors have been implicated in fibrosis, the underlying mechanism of fibrosis via Sphingosine 1-phosphate receptor 2 (S1P₂) has not been fully investigated. Therefore, in this study, the roles of S1P₂ in lung inflammation and fibrosis was investigated by means of a bleomycin-induced lung fibrosis model and lung epithelial cells. Bleomycin was found to induce lung inflammation on day 7 and fibrosis on day 28 of treatment. On the 7(th) day after bleomycin administration, S1P₂ deficient mice exhibited significantly less pulmonary inflammation, including cell infiltration and pro-inflammatory cytokine induction, than the wild type mice. On the 28(th) day after bleomycin treatment, severe inflammation and fibrosis were observed in lung tissues from wild type mice, while lung tissues from S1P₂ deficient mice showed less inflammation and fibrosis. Increase in TGF-β1-induced extracellular matrix accumulation and epithelial-mesenchymal transition were inhibited by JTE-013, a S1P₂ antagonist, in A549 lung epithelial cells. Taken together, pro-inflammatory and pro-fibrotic functions of S1P₂ were elucidated using a bleomycin-induced fibrosis model. Notably, S1P₂ was found to mediate epithelial-mesenchymal transition in fibrotic responses. Therefore, the results of this study indicate that S1P₂ could be a promising therapeutic target for the treatment of pulmonary fibrosis.

Pro-Inflammatory Role of S1P₃ in Macrophages

Sphingosine kinase 1 and its product, sphingosine 1-phosphate (S1P), as well as their receptors, have been implicated in inflammatory responses. The functions of receptors S1P₁ and S1P₂ on cell motility have been investigated. However, the function of S1P₃ has been poorly investigated. In this study, the roles of S1P₃ on inflammatory response were investigated in primary perito-neal macrophages. S1P₃ receptor was induced along with sphingosine kinase 1 by stimulation of lipopolysaccharide (LPS). LPS treatment induced inflammatory genes, such iNOS, COX-2, IL-1β, IL-6 and TNF-α. TY52156, an antagonist of S1P₃ suppressed the induction of inflammatory genes in a concentration dependent manner. Suppression of iNOS and COX-2 induction was further confirmed by western blotting and NO measurement. Suppression of IL-1β induction was also confirmed by western blotting and ELISA. Caspase 1, which is responsible for IL-1β production, was similarly induced by LPS and suppressed by TY52156. Therefore, we have shown S1P₃ induction in the inflammatory conditions and its pro-inflammatory roles. Targeting S1P₃ might be a strategy for regulating inflammatory diseases.

S1P₁ Regulates M1/M2 Polarization toward Brain Injury after Transient Focal Cerebral Ischemia

M1/M2 polarization of immune cells including microglia has been well characterized. It mediates detrimental or beneficial roles in neuroinflammatory disorders including cerebral ischemia. We have previously found that sphingosine 1-phospate receptor subtype 1 (S1P₁) in post-ischemic brain following transient middle cerebral artery occlusion (tMCAO) can trigger microglial activation, leading to brain damage. Although the link between S1P₁ and microglial activation as a pathogenesis in cerebral ischemia had been clearly demonstrated, whether the pathogenic role of S1P₁ is associated with its regulation of M1/M2 polarization remains unclear. Thus, this study aimed to determine whether S1P₁ was associated with regulation of M1/M2 polarization in post-ischemic brain. Suppressing S1P₁ activity with its functional antagonist, AUY954 (5 mg/kg, p.o.), attenuated mRNA upregulation of M1 polarization markers in post-ischemic brain at 1 day and 3 days after tMCAO challenge. Similarly, suppressing S1P₁ activity with AUY954 administration inhibited M1-polarizatioin-relevant NF-κB activation in post-ischemic brain. Particularly, NF-κB activation was observed in activated microglia of post-ischemic brain and markedly attenuated by AUY954, indicating that M1 polarization through S1P₁ in post-ischemic brain mainly occurred in activated microglia. Suppressing S1P₁ activity with AUY954 also increased mRNA expression levels of M2 polarization markers in post-ischemic brain, further indicating that S1P₁ could also influence M2 polarization in post-ischemic brain. Finally, suppressing S1P₁ activity decreased phosphorylation of M1-relevant ERK1/2, p38, and JNK MAPKs, but increased phosphorylation of M2-relevant Akt, all of which were downstream pathways following S1P₁ activation. Overall, these results revealed S1P₁-regulated M1/M2 polarization toward brain damage as a pathogenesis of cerebral ischemia.

Expression of PFKFB3 and S1P2 in the retina of type 2 diabetic rats and the intervention effect of tBHQ / 眼科新进展

Objective To investigate the expression of 6-phosphofructo-2-kinase /fructose-2,6-bisphosphatase-3 (PFKFB3) and sphingosine 1-phosphate receptor 2 (S1 P2) in the retina of rats with type 2 diabetes mellitus (DM) and to explore the correlation of tertiary butylhydroquinone (tBHQ) with PFKFB3 and S1P2.Methods Together 60 male SD rats were divided into normal control group (NC group),diabetes mellitus group (DM group) and tBHQ group.Type 2 DM model was induced in the latter two groups.The rats in tBHQ group were given 10 g · L-1 tBHQ in high-fat and highsugar diet 1 week after successful modeling,while DM rats were fed with high-fat and high-sugar diet continuously.At 4 weeks and 12 weeks after tBHQ intervention,blood samples were taken from the hearts of rats in each group,and serum contents of fasting plasma glucose (FPG) and fasting serum insulin (FINs) were measured.Immunohistochemistry and qRT-PCR were taken to detect the distribution and expression of PFKFB3,S1 P2 and vascular endothehal growth factor (VEGF) mRNA and protein in the retina,and TUNEL methods were used to detect apoptosis index of retinal ganglion cells of rats in each group.Results There were significant difference in the FPG and FINs levels of the three groups at 4 weeks and 12 weeks (all P =0.000).Light microscopy test showed that positive expressions of PFKFB3,S1 P2 and VEGF protein were found in all groups at 4 and 12 weeks,which were mainly located in the retinal ganglion cell layer and the inner nuclear layer.Immunohistochemistry and qRT-PCR showed that the difference in relative expressions of PFKFB3,S1P2,VEGF protein and mRNA in the retina at different times after modeling were statistically significant (all P ＜ 0.05).At 4 and 12 weeks,the expression levels of PFKFB3,S1P2 and VEGF in DM group were higher than those in NC group,but their expressions in tBHQ group were significantly downregulated when compared with DM group,and all differences were statistically significant (all P ＜ 0.05).Compared with 4 weeks,PFKFB3,S1 P2 and VEGF mRNA and protein in DM group were overexpressed at 12 weeks,and the expression level of S1 P2 in tBHQ group at 12 weeks was lower than that at 4 weeks,and the differences were statistically significant (all P ＜ 0.05).TUNEL assays showed that there was significant difference in the apoptotic index (AI) of retinal ganglion cells of rats in each group at different times after modeling (all P ＜ 0.05).DM group had higher AI than NC group (P ＜ 0.05),and tBHQ group was lower than DM group (P ＜ 0.05);Compared with 4 weeks,DM group had increased AI at 12 weeks while tBHQ group had decreased AI (both P ＜ 0.05).Conclusion PFKFB3,S1P2 and VEGF are involved in the pathological process of the retina of type 2 DM rats,which may play a role through the PFKFB3 / VEGF / S1P2 signaling pathway and may be related to the apoptosis of retinal ganglion cells.And it is indicated that tBHQ has a protective effect on the retina of type 2 DM rats.

Effects of FoxO1 on FoxO1-KLF2-S1P1 pathway in Jurkat cells / 中国免疫学杂志

To observe the contribution of FoxO1 on its downstream molecules expression and function in Jurkat cells,Jurkat cells were infected with FoxO1 expression lentivirus and interference lentivirus to establish FoxO1-KLF2-S1P1 signaling pathways mod-el.After infection of 120 h,FoxO1,KLF2,S1P1 and CD62L mRNA levels and the protein expression of FoxO1,FoxO1-p and KLF2 were increased (P<0.05) in FoxO1-overexpression group.Converse results(P<0.05) were observed in the interference group.The proportions of S1P1+cells were increased in both groups.It was notably that S1P1+cells were decreased(P<0.05) in interference group after infection of 72 h.The proportion of CD62L+cells was increased(P<0.05) in overexpression group,it was decreased(P<0.05) in the interference group.This vitro experiments showed S1P1 and CD62L could be regulated by FoxO1 lentivirus,and provided an experimental basis for research about intracellular FoxO1-KLF2-S1P1 signaling pathways and cellular functions.

Decreased Expression of Sphingosine-1-Phosphate Receptor 1 in the Blood Leukocyte of Rheumatoid Arthritis Patients

Sphingosine-1-phosphate (S1P) plays an important role in trafficking leukocytes and developing immune disorders including autoimmunity. In the synovium of rheumatoid arthritis (RA) patients, increased expression of S1P was reported, and the interaction between S1P and S1P receptor 1 (S1P1) has been suggested to regulate the expression of inflammatory genes and the proliferation of synovial cells. In this study, we investigated the level of S1P1 mRNA expression in the blood leukocytes of RA patients. In contrast to the previous reports, the expression level of this gene was not correlated to their clinical scores, disease durations and ages. However, S1P1 was transcribed at a significantly lower level in the circulating leukocytes of RA patients when compared to age-, and sex-matched healthy controls. Since these data may suggest the participation of S1P1, further studies are needed to determine the role of this receptor in the pathogenesis of RA.

Sphingosine 1-Phosphate Receptor Modulators and Drug Discovery

Initial discovery on sphingosine 1-phosphate (S1P) as an intracellular second messenger was faced unexpectedly with roles of S1P as a first messenger, which subsequently resulted in cloning of its G protein-coupled receptors, S1P₁₋₅. The molecular identification of S1P receptors opened up a new avenue for pathophysiological research on this lipid mediator. Cellular and molecular in vitro studies and in vivo studies on gene deficient mice have elucidated cellular signaling pathways and the pathophysiological meanings of S1P receptors. Another unexpected finding that fingolimod (FTY720) modulates S1P receptors accelerated drug discovery in this field. Fingolimod was approved as a first-in-class, orally active drug for relapsing multiple sclerosis in 2010, and its applications in other disease conditions are currently under clinical trials. In addition, more selective S1P receptor modulators with better pharmacokinetic profiles and fewer side effects are under development. Some of them are being clinically tested in the contexts of multiple sclerosis and other autoimmune and inflammatory disorders, such as, psoriasis, Crohn’s disease, ulcerative colitis, polymyositis, dermatomyositis, liver failure, renal failure, acute stroke, and transplant rejection. In this review, the authors discuss the state of the art regarding the status of drug discovery efforts targeting S1P receptors and place emphasis on potential clinical applications.

The role of SPHK-1 in non-small cell lung cancer drug-resistant cell line H460 / 西安交通大学学报(医学版)

Objective To examine the role of SPHK-1/S1P and NFκB p65 signal pathway in non-small cell lung cancer (NSCLC)drug-resistant cells.Methods The drug-resistant cell line of lung cancer H460/DDP was constructed and its biological characteristics were identified successfully.The expression of SPHK-l was tested by RT-PCR and Western blot methods.S1 P and some proteins related to NFκB pathway were studied by Western blot. Results The drug-resistant lung cancer cell line H460/DDP was constructed and its drug-resistant ability was evaluated (IC50H460/DDP = 50.62μg/mL, RIH460/DDP = 2.95 ). Cisplatin at a concentration of 10 - 80 μg/mL significantly decreased cell death of drug-resistant cell line (P<0 .01 ).Western blot assay analysis showed that overexpressions of SPHK-l,S1 P and NFκB p65 were significantly higher in drug-resistant cell line than in their parent cell line H460 (P=0.0415,P=0.0465,P=0.0218).RT-PCR method revealed that SPHK-1 mRNA was overexpressed in drug-resistant cell line compared with that in their parent cell line H460 (P<0.05).More NFκB p65 protein in cell nucleus was expressed in drug-resistant cells than in parent cells.Conclusion SPHK-1/S1P and NFκB p65 signal pathway may play an improtant role in the drug-resistant H460 cell line in non-small cell lung cancer.

Sphingosine 1-phosphate signaling pathway:a novel target for regulation of epithelial and endothelial barrier function / 中国药科大学学报

@#Sphingosine 1-phosphate(S1P)is a pleiotropic sphingolipid metabolite that has been shown to regulate important physiological function by activation of its G-protein-coupled receptors S1PRs. S1P has been identified as an important signaling molecule in maintaining epithelial and endothelial barrier function. S1P signaling pathway is involved in epithelial and endothelial barrier function by regulation of adherens junction and tight junction assembly, cytoskeletal reorganization, and focal adhesion formation. Thus, S1P signaling pathway may become a novel therapeutic target for cell barrier dysfunction during some illnesses such as acute lung injury, inflammatory bowel disease and sepsis. In this review, the research progress of S1P signaling pathway in regulating epithelial and endothelial barrier function and the application of S1P in barrier dysfunction-related diseases were summarized, so as to provide references for future research.