Metformin alleviates inflammation in oxazolone induced ulcerative colitis in rats: plausible role of sphingosine kinase 1/sphingosine 1 phosphate signaling pathway.

OBJECTIVES: Ulcerative colitis (UC) is a chronic inflammatory bowel disease that is associated with high sphingosine kinase 1(SPHK1) expression in the colon, however its role in pathogenesis of UC is not clearly understood so, the aim of the present study was to clarify the role of SPHK1 and investigate whether the anti-inflammatory effects of metformin in UC is mediated by Sphingosine kinase 1/sphingosine 1 phosphate (S1P) signaling pathway. MATERIAL AND METHODS: Colitis was induced in adult male wistar rats by intra rectal administration of oxazolone in the fifth and seventh days from initial presensitization. Oxazolone treated rats were divided into untreated oxazolone group, metformin and mesalazine treated groups both in a dose of 100 mg/kg/day orally for 21 days. Along with these groups normal control and saline groups were used .Colitis was assessed by colon length, disease activity index (DAI) and histological examination of colontissue. Plasma samples were used to measure S1P.SPHK1 activity, signal transducer and activator of transcription -3(STAT-3), interleukin-6 (IL-6), nitric oxide (NO), myeloperoxidase activity (MPO), reduced glutathione (GSH) and tissue expression of intracellular cell adhesion molecule -1(ICAM-1) and caspase-3 genes were measured in tissue. RESULTS: Metformin successfully attenuated oxazolone colitis by increasing colon length, decreasing DAI and improved colon histologic picture. Metformin also induced a significant decrease in Plasma SIP, SPHK1 activity, inflammatory, oxidative stress markers, ICAM-1 and Caspase-3 genes expression compared to oxazolone group. CONCLUSION: It is revealed that metformin alleviated inflammation and underlying mechanism may result from inhibition of SPHK1/S1P signaling pathway.

Implementation of the plasma MYCN/NAGK ratio to detect MYCN amplification in patients with neuroblastoma.

Detection of amplification of the MYCN gene is essential for determining optimal treatment and estimating prognosis of patients with neuroblastoma (NB). DNA FISH with neuroblastoma tissues or patient-derived bone marrow cells is the standard clinical practice for the detection of MYCN amplification. As tumor cells may often be unavailable, we developed a method to detect MYCN amplification in the plasma of patients with neuroblastoma. Taking single-copy NAGK DNA as reference, we used real-time quantitative PCR (qPCR) to determine the MYCN/NAGK ratio in the plasma of 115 patients diagnosed with NB. An increased MYCN/NAGK ratio in the plasma was consistent with MYCN amplification as assessed by DNA FISH. The AUC for a MYCN/NAGK ratio equal to 6.965 was 0.943, with 86% sensitivity and 100% specificity. Beyond the threshold of 6.965, the MYCN/NAGK ratio correlated with a heavier tumor burden. Event-free and overall survival of two years were significantly shortened in stage 4 patients with a MYCN/NAGK ratio higher than 6.965. Plasma MYCN/NAGK ratios increased in patients with progressive disease and relapse. Thus, we conclude that the determination of the plasma MYCN/NAGK ratio by qPCR is a noninvasive and reproducible method to measure MYCN amplification in patients with NB.

Decreased S1P and SPHK2 are involved in pancreatic acinar cell injury.

Aim: The roles of S1P in acute pancreatitis (AP) or non-AP patients with pancreatic acinar cell injury (PACI) are not well understood. Materials & methods: Serum S1P, in 40 healthy individuals and 99 patients with PACI, was retrospectively analyzed. Additionally, we detected and analyzed S1P in AP mice and the AR42J acinar cell line. Results: Serum S1P was significantly decreased in PACI patients, compared with that of healthy controls. Patients with gall stones, normal serum calcium or normal blood lipids showed relative higher levels of serum S1P. Interestingly, in patients with gall or liver disease, serum S1P was positively associated with γ-GT and ALT. Additionally, S1P and SPHK2 were decreased in AP mice and AR42J cells, relative to the levels of corresponding controls. Conclusion: Serum S1P is decreased in PACI, which may be partly due to downregulation of pancreatic SPHK2.

The involvement of blood cells in the phosphorylation of the selective sphingosine-1-phosphate receptor 1 agonist SYL-927.

SYL-927 is a selective sphingosine-1-phosphate receptor 1 (S1P1) agonist for autoimmune diseases. It undergoes phosphorylation to the active SYL-927-P in vivo, which activates S1P1 on lymphocytes, causing lymphopenia by retention of lymphocytes in the lymph nodes. The aim of this study was to identify the involvement of blood cells in the phosphorylation of SYL-927. In addition, pharmacokinetics of SYL-927 and SYL-927-P in blood and plasma were compared in rats. The results demonstrated that SYL-927 can be converted to SYL-927-P in rat blood, but not in rat plasma. However, both rat blood and plasma are capable of dephosphorylating SYL-927-P to SYL-927. SYL-927-P generation and release were observed after incubating SYL-927 with rat and human erythrocytes and platelets. The addition of sphingosine kinases (SPHKs) inhibitors N,N-dimethylsphingosine (DMS) and FTY720 significantly inhibited SYL-927-P generation, indicating the involvement of SPHKs. In addition, SYL-927 and SYL-927-P levels in blood were significantly higher than those in plasma after oral administration of SYL-927 in rats, suggesting the blood cells for the production of SYL-927-P. In summary, the blood cells such as erythrocytes and platelets contribute to the generation and release of SYL-927-P, which is important for maintaining plasma active phosphate levels for prolonged effects.

Transforming Growth Factor ß1 (TGF-ß1) Appears to Promote Coronary Artery Disease by Upregulating Sphingosine Kinase 1 (SPHK1) and Further Upregulating Its Downstream TIMP-1.

BACKGROUND Transforming growth factor (TGF)-ß1 is involved in the pathogenesis of coronary artery disease (CAD), but the mechanism of its action remains unclear. Our study aimed to investigate the role of TGF-ß1 in CAD and to explore the possible mechanisms. MATERIAL AND METHODS A total of 60 CAD patients and 54 healthy people were included in this study. Blood samples were drawn from each participant to prepare serum. ELISA was utilized to measure serum level of TGF-ß1. TGF-ß1 expression vector, TGF-ß1 siRNA, and TIMP-1 siRNA were transfected into human primary coronary artery endothelial cell (HCAEC) line cells, and expression of TGF-ß1 sphingosine kinase 1 (SPHK1) and TIMP metallopeptidase inhibitor 1 (TIMP-1) was detected by Western blot. Cell apoptosis was detected by MTT assay. RESULTS Serum level of TGF-ß1 was specifically higher in patients with CAD than in healthy controls. Serum levels of active TGF-ß1 can be used to effectively distinguish CAD patients from healthy controls. TGF-ß1 overexpression promoted the apoptosis of HCAEC and TGF-ß1 siRNA silencing inhibited the apoptosis of HCAEC. TGF-ß1 overexpression also promoted the expression of SPHK1 and TIMP-1. SPHK1 overexpression upregulated TIMP-1 but it showed no significant effects on TGF-ß1. TIMP-1 overexpression showed no significant effects on TGF-ß1 or SPHK1. SPHK1 inhibitor and TIMP-1 silencing reduced the enhancing effects of TGF-ß1 overexpression on cell apoptosis. CONCLUSIONS TGF-ß1 appears to promote CAD through the induction of cell apoptosis by upregulating SPHK1 expression and further upregulating its downstream TIMP-1.

Gene expression profiles of immune-regulatory genes in whole blood of cattle with a subclinical infection of Mycobacterium avium subsp. paratuberculosis.

Johne's disease is a chronic wasting disease of ruminants caused by Mycobacterium avium subsp. paratuberculosis (MAP), resulting in inflammation of intestines and persistent diarrhea. The initial host response against MAP infections is mainly regulated by the Th1 response, which is characterized by the production of IFN-γ. With the progression of disease, MAP can survive in the host through the evasion of the host's immune response by manipulating the host immune response. However, the host response during subclinical phases has not been fully understood. Immune regulatory genes, including Th17-derived cytokines, interferon regulatory factors, and calcium signaling-associated genes, are hypothesized to play an important role during subclinical phases of Johne's disease. Therefore, the present study was conducted to analyze the expression profiles of immune regulatory genes during MAP infection in whole blood. Different expression patterns of genes were identified depending on the infection stages. Downregulation of IL-17A, IL-17F, IL-22, IL-26, HMGB1, and IRF4 and upregulation of PIP5K1C indicate suppression of the Th1 response due to MAP infection and loss of granuloma integrity. In addition, increased expression of IRF5 and IRF7 suggest activation of IFN-α/ß signaling during subclinical stages, which induced indoleamine 2,3-dioxygenase mediated depletion of tryptophan metabolism. Increased expression of CORO1A indicate modulation of calcium signaling, which enhanced the survival of MAP. Taken together, distinct host gene expression induced by MAP infection indicates enhanced survival of MAP during subclinical stages.

Spectrophotometric assays for measuring redox biomarkers in blood and tissues: the NADPH network.

Nicotinamide adenine dinucleotide (NAD+/NADH) along with its phosphorylated form (NADP+/NADPH) are two molecules ubiquitously present in all organisms, and they play key roles as cofactors in fundamental catabolic and anabolic processes, respectively. The oxidation of NADPH to NADP+ initiates a cascade of reactions, where a network of molecules is implicated. The molecules of this cascade form a network with eminent translational potential in redox metabolism. A special point of interest is that spectrophotometric assays have been developed both for NADH/NADPH and the molecules directly regulated by them. Therefore, crucial molecules of the NADPH-dependent redox network can be measured, and the results can be used to assess the bioenergetic and/or oxidative stress status. The main aim of this review is to collectively present the NADPH-related molecules, namely NADPH, NADH, NAD+ kinase, NADPH oxidase, peroxiredoxin, thioredoxin, thioredoxin reductase, and nitric oxide synthase, that can be measured in blood and tissues with the use of a spectrophotometer, which is probably the most simple, inexpensive and widely used tool in biochemistry. We are providing the researchers with reliable and valid spectrophotometric assays for the measurement of the most important biomarkers of the NADPH network in blood and other tissues, thus allowing the opportunity to follow the redox changes in response to a stimulus.

A simple colorimetric assay for measuring fructosamine 3 kinase activity.

BACKGROUND: Fructosamine 3 kinase (FN3K) is a deglycating enzyme, which may play a key role in reducing diabetes-induced organ damage by removing bound glucose from glycated proteins. We wanted to develop a simple colorimetric method for assaying FN3K activity in human body fluids. METHODS: Glycated bovine serum albumin (BSA) was obtained by glycation with a 10% glucose solution at 37 °C. After 72 h, glycated BSA was dialyzed against phosphate buffered saline (0.1 mol/L, pH 7.4). The dialyzed solution (containing ±1000 µmol/L fructosamine) was used as an FN3K substrate. In the assay, 300 µL of substrate was incubated with 50 µL of serum and 100 µL of MgCl2 (0.7 mmol/L)/ATP (3.2 mmol/L). The fructosamine concentration was determined at the start and after incubation (120 min, 25 °C). The decrease in fructosamine concentration over time is a measure for the FN3K activity (1 U corresponding to 1 µmol/min). Concomitantly, the FN3K SNP rs1056534 and the ferroportin SNP rs1156350 were genotyped. RESULTS: Within-assay CV was 6.0%. Reference values for FN3K activity in serum were 14.2±1.6 U/L (n=143). Reference values for FN3K were neither age- nor sex-dependent. The various FN3K SNP rs1056534 genotypes showed no significant differences in serum FN3K activity. In diabetics (n=191), values (14.0±2.2 U/L) were comparable to those of the controls. FN3K activity in erythrocytes was significantly higher (170.3±7.6 U/L). The intra-erythrocytic FN3K activity makes the results prone to hemolysis. FN3K activity depended on the ferroportin Q248H genotypes, with the highest value for the wild type genotype. Neither transferrin saturation nor ferritin were confounders for the FN3K activity. FN3K activity was significantly (p<0.0001) correlated with HbA1c values, although the correlation between FN3K and HbA1c was weak. CONCLUSIONS: The simple colorimetric method allows determining FN3K activity in human serum. The assay may be useful for studying the impact of deglycation processes in diabetes mellitus.

Sphingosine-1-phosphate promotes erythrocyte glycolysis and oxygen release for adaptation to high-altitude hypoxia.

Sphingosine-1-phosphate (S1P) is a bioactive signalling lipid highly enriched in mature erythrocytes, with unknown functions pertaining to erythrocyte physiology. Here by employing nonbiased high-throughput metabolomic profiling, we show that erythrocyte S1P levels rapidly increase in 21 healthy lowland volunteers at 5,260 m altitude on day 1 and continue increasing to 16 days with concurrently elevated erythrocyte sphingonisne kinase 1 (Sphk1) activity and haemoglobin (Hb) oxygen (O2) release capacity. Mouse genetic studies show that elevated erythrocyte Sphk1-induced S1P protects against tissue hypoxia by inducing O2 release. Mechanistically, we show that intracellular S1P promotes deoxygenated Hb anchoring to the membrane, enhances the release of membrane-bound glycolytic enzymes to the cytosol, induces glycolysis and thus the production of 2,3-bisphosphoglycerate (2,3-BPG), an erythrocyte-specific glycolytic intermediate, which facilitates O2 release. Altogether, we reveal S1P as an intracellular hypoxia-responsive biolipid promoting erythrocyte glycolysis, O2 delivery and thus new therapeutic opportunities to counteract tissue hypoxia.

Identification of three mutations in the MVK gene in six patients associated with disseminated superficial actinic porokeratosis.

Porokeratosis is recognized as a heterogenously inherited epidermal keratinization disorder. Disseminated superficial actinic porokeratosis (DSAP) is considered to be the most common form of porokeratosis and is characterized by multiple, small keratotic lesions on sun-exposed areas of body. MVK has been reported to be the main candidate gene associated with DSAP. In this study, six sporadic cases of DSAP were clinically characterized. Direct DNA sequencing analysis of the whole coding regions of MVK detected three MVK missense mutations, and two were novel for DSAP: c.31C>T (P11S) and c.1004G>A (G335D). The three mutant MVK proteins were less stable than the wild type protein in different degrees. Mutation G335D also resulted in the misfolding of the ATP binding domain. This study extends the mutation spectrum of MVK. MVK protein stability and correct folding might be the molecular mechanism causing DASP. A 50% probability of detecting a MVK mutation in six DSAP sporadic cases indicated that the MVK gene was useful for clinical characterization, genetic counseling and prenatal diagnosis of DSAP.

Anti-cancer and cardioprotective effects of indol-3-carbinol in doxorubicin-treated mice.

Doxorubicin (DOX) is a broad-spectrum antitumor antibiotic used in treatment of cancer. Its effect may be complicated by increased risk of cardiotoxicity. It was suggested that natural compounds with anticancer properties can be used in combination with DOX to decrease its dose and side effects. Indole-3-carbinol (I3C) is one of the phytochemicals that was shown to have anti-cancer effect. Our aim was to detect the possible chemosensitizing effects of I3C in DOX-induced cytotoxicity and the possible cardioprotective effects of I3C in DOX-induced cardiotoxicity. One hundred mice were divided into five equal groups: Control untreated group, solid Ehrlich carcinoma (SEC), SEC + DOX, SEC + I3C, SEC + DOX + I3C. Tumor volume, serum creatinine kinase and lactate dehydrogenase were measured. Also, tissue malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD), sphingosine kinase-1 (SphK1) activity and interleukin-6 (IL-6) were determined. Parts of the tumor and cardiac tissues were subjected to histopathological examination. DOX or I3C alone or in combination induced significant increase in tumor CAT and SOD with significant decrease in tumor volume, tumor MDA, SphK1 activity and IL-6 and alleviated the histopathological changes with significant increase in the apoptotic index and significant decrease in tissue bcl2 compared to SEC group. Also, DOX induced cardiotoxicity which was ameliorated by I3C. In conclusion, DOX/I3C combination had a better effect than each of DOX or I3C alone against SEC in mice with marked improvement of the cardiotoxicity induced by DOX.

Improvement of prognostic performance in severely injured patients by integrated clinico-transcriptomics: a translational approach.

INTRODUCTION: Severe trauma triggers a systemic inflammatory response that contributes to secondary complications, such as nosocomial infections, sepsis or multi-organ failure. The present study was aimed to identify markers predicting complications and an adverse outcome of severely injured patients by an integrated clinico-transcriptomic approach. METHODS: In a prospective study, RNA samples from circulating leukocytes from severely injured patients (injury severity score ≥ 17 points; n = 104) admitted to a Level I Trauma Center were analyzed for dynamic changes in gene expression over a period of 21 days by quantitative RT-PCR. Transcriptomic candidates were selected based on whole genome screening of a representative discovery set (n = 10 patients) or known mechanisms of the immune response, including mediators of inflammation (IL-8, IL-10, TNF-α, MIF, C5, CD59, SPHK1), danger signaling (HMGB1, TLR2, CD14, IL-33, IL-1RL1), and components of the heme degradation pathway (HP, CD163, HMOX1, BLVRA, BLVRB). Clinical markers comprised standard physiological and laboratory parameters and scoring systems routinely determined in trauma patients. RESULTS: Leukocytes, thrombocytes and the expression of sphingosine kinase-1 (SPHK1), complement C5, and haptoglobin (HP) have been identified as markers with the best performance. Leukocytes showed a biphasic course with peaks on day 0 and day 11 after trauma, and patients with sepsis exhibited significantly higher leukocyte levels. Thrombocyte numbers showed a typical profile with initial thrombopenia and robust thrombocytosis in week 3 after trauma, ranging 2- to 3-fold above the upper normal value. 'Relative thrombocytopenia' was associated with multi-organ dysfunction, the development of sepsis, and mortality, the latter of which could be predicted within 3 days prior to the time point of death. SPHK1 expression at the day of admission indicated mortality with excellent performance. C5-expression on day 1 after trauma correlated with an increased risk for the development of nosocomial infections during the later course, while HP was found to be a marker for the development of sepsis. CONCLUSIONS: The combination of clinical and transcriptomic markers improves the prognostic performance and may represent a useful tool for individual risk stratification in trauma patients.

Sphingosine 1-Phosphate Produced by Sphingosine Kinase 2 Intrinsically Controls Platelet Aggregation In Vitro and In Vivo.

RATIONALE: Platelets are known to play a crucial role in hemostasis. Sphingosine kinases (Sphk) 1 and 2 catalyze the conversion of sphingosine to the bioactive metabolite sphingosine 1-phosphate (S1P). Although platelets are able to secrete S1P on activation, little is known about a potential intrinsic effect of S1P on platelet function. OBJECTIVE: To investigate the role of Sphk1- and Sphk2-derived S1P in the regulation of platelet function. METHODS AND RESULTS: We found a 100-fold reduction in intracellular S1P levels in platelets derived from Sphk2(-/-) mutants compared with Sphk1(-/-) or wild-type mice, as analyzed by mass spectrometry. Sphk2(-/-) platelets also failed to secrete S1P on stimulation. Blood from Sphk2-deficient mice showed decreased aggregation after protease-activated receptor 4-peptide and adenosine diphosphate stimulation in vitro, as assessed by whole blood impedance aggregometry. We revealed that S1P controls platelet aggregation via the sphingosine 1-phosphate receptor 1 through modulation of protease-activated receptor 4-peptide and adenosine diphosphate-induced platelet activation. Finally, we show by intravital microscopy that defective platelet aggregation in Sphk2-deficient mice translates into reduced arterial thrombus stability in vivo. CONCLUSIONS: We demonstrate that Sphk2 is the major Sphk isoform responsible for the generation of S1P in platelets and plays a pivotal intrinsic role in the control of platelet activation. Correspondingly, Sphk2-deficient mice are protected from arterial thrombosis after vascular injury, but have normal bleeding times. Targeting this pathway could therefore present a new therapeutic strategy to prevent thrombosis.

Analysis of sphingosine kinase activity in single natural killer cells from peripheral blood.

Sphingosine-1-phosphate (S1P), a lipid second messenger formed upon phosphorylation of sphingosine by sphingosine kinase (SK), plays a crucial role in natural killer (NK) cell proliferation, migration, and cytotoxicity. Dysregulation of the S1P pathway has been linked to a number of immune system disorders and therapeutic manipulation of the pathway has been proposed as a method of disease intervention. However, peripheral blood NK cells, as identified by surface markers (CD56(+)CD45(+)CD3(-)CD16) consist of a highly diverse population with distinct phenotypes and functions and it is unknown whether the S1P pathway is similarly diverse across peripheral blood NK cells. In this work, we measured the phosphorylation of sphingosine-fluorescein (SF) and subsequent metabolism of S1P fluorescein (S1PF) to form hexadecanoic acid fluorescein (HAF) in 111 single NK cells obtained from the peripheral blood of four healthy human subjects. The percentage of SF converted to S1PF or HAF was highly variable amongst the cells ranging from 0% to 100% (S1PF) and 0% to 97% (HAF). Subpopulations of cells with varying levels of S1PF formation and metabolism were readily identified. Across all subjects, the average percentage of SF converted to S1PF or HAF was 37 ± 36% and 12 ± 19%, respectively. NK cell metabolism of SF by the different subjects was also distinct with hierarchical clustering suggesting two possible phenotypes: low (<20%) or high (>50%) producers of S1PF. The heterogeneity of SK and downstream enzyme activity in NK cells may enable NK cells to respond effectively to a diverse array of pathogens as well as incipient tumor cells. NK cells from two subjects were also loaded with S1PF to assess the activity of S1P phosphatase (S1PP), which converts S1P to sphingosine. No NK cells (n = 41) formed sphingosine, suggesting that S1PP was minimally active in peripheral blood NK cells. In contrast to the SK activity, S1PP activity was homogeneous across the peripheral blood NK cells, suggesting a bias in the SK pathway towards proliferation and migration, activities supported by S1P.

Elevated adenosine signaling via adenosine A2B receptor induces normal and sickle erythrocyte sphingosine kinase 1 activity.

Erythrocyte possesses high sphingosine kinase 1 (SphK1) activity and is the major cell type supplying plasma sphingosine-1-phosphate, a signaling lipid regulating multiple physiological and pathological functions. Recent studies revealed that erythrocyte SphK1 activity is upregulated in sickle cell disease (SCD) and contributes to sickling and disease progression. However, how erythrocyte SphK1 activity is regulated remains unknown. Here we report that adenosine induces SphK1 activity in human and mouse sickle and normal erythrocytes in vitro. Next, using 4 adenosine receptor-deficient mice and pharmacological approaches, we determined that the A2B adenosine receptor (ADORA2B) is essential for adenosine-induced SphK1 activity in human and mouse normal and sickle erythrocytes in vitro. Subsequently, we provide in vivo genetic evidence that adenosine deaminase (ADA) deficiency leads to excess plasma adenosine and elevated erythrocyte SphK1 activity. Lowering adenosine by ADA enzyme therapy or genetic deletion of ADORA2B significantly reduced excess adenosine-induced erythrocyte SphK1 activity in ADA-deficient mice. Finally, we revealed that protein kinase A-mediated extracellular signal-regulated kinase 1/2 activation functioning downstream of ADORA2B underlies adenosine-induced erythrocyte SphK1 activity. Overall, our findings reveal a novel signaling network regulating erythrocyte SphK1 and highlight innovative mechanisms regulating SphK1 activity in normal and SCD.

Sphingosine kinase 1 dependent protein kinase C-δ activation plays an important role in acute liver failure in mice.

AIM: To investigate the role of protein kinase C (PKC)-δ activation in the pathogenesis of acute liver failure (ALF) in a well-characterized mouse model of D-galactosamine (D-GalN)/lipopolysaccharide (LPS)-induced ALF. METHODS: BALB/c mice were randomly assigned to five groups, and ALF was induced in mice by intraperitoneal injection of D-GaIN (600 mg/kg) and LPS (10 µg/kg). Kaplan-Meier method was used for survival analysis. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels at different time points within one week were determined using a multiparameteric analyzer. Serum levels of high-mobility group box 1 (HMGB1), tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, IL-6, and IL-10 as well as nuclear factor (NF)-κB activity were determined by enzyme-linked immunosorbent assay. Hepatic morphological changes at 36 h after ALF induction were assessed by hematoxylin and eosin staining. Expression of PKC-δ in liver tissue and peripheral blood mononuclear cells (PBMCs) was analyzed by Western blot. RESULTS: The expression and activation of PKC-δ were up-regulated in liver tissue and PBMCs of mice with D-GalN/LPS-induced ALF. Inhibition of PKC-δ activation with rottlerin significantly increased the survival rates and decreased serum ALT/AST levels at 6, 12 and 24 h compared with the control group (P < 0.001). Rottlerin treatment also significantly decreased serum levels of HMGB1 at 6, 12, and 24 h, TNF-α, IL-6 and IL-1 ß at 12 h compared with the control group (P < 0.01). The inflammatory cell infiltration and necrosis in liver tissue were also decreased in the rottlerin treatment group. Furthermore, sphingosine kinase 1 (SphK1) dependent PKC-δ activation played an important role in promoting NF-κB activation and inflammatory cytokine production in ALF. CONCLUSION: SphK1 dependent PKC-δ activation plays an important role in promoting NF-κB activation and inflammatory response in ALF, and inhibition of PKC-δ activation might be a potential therapeutic strategy for this disease.

Elevated sphingosine-1-phosphate promotes sickling and sickle cell disease progression.

Sphingosine-1-phosphate (S1P) is a bioactive lipid that regulates multicellular functions through interactions with its receptors on cell surfaces. S1P is enriched and stored in erythrocytes; however, it is not clear whether alterations in S1P are involved in the prevalent and debilitating hemolytic disorder sickle cell disease (SCD). Here, using metabolomic screening, we found that S1P is highly elevated in the blood of mice and humans with SCD. In murine models of SCD, we demonstrated that elevated erythrocyte sphingosine kinase 1 (SPHK1) underlies sickling and disease progression by increasing S1P levels in the blood. Additionally, we observed elevated SPHK1 activity in erythrocytes and increased S1P in blood collected from patients with SCD and demonstrated a direct impact of elevated SPHK1-mediated production of S1P on sickling that was independent of S1P receptor activation in isolated erythrocytes. Together, our findings provide insights into erythrocyte pathophysiology, revealing that a SPHK1-mediated elevation of S1P contributes to sickling and promotes disease progression, and highlight potential therapeutic opportunities for SCD.

Serum dihydroxyacetone kinase peptide m/z 520.3 as predictor of disease severity in patients with compensated chronic hepatitis B.

BACKGROUND AND AIM: Due to known limitations of liver biopsy, reliable non-invasive serum biomarkers for chronic liver diseases are needed. We performed serum peptidomics for such investigation in compensated chronic hepatitis B (CHB) patients. METHODS: Liquid chromatography combined with tandem mass spectrometry (LC-MS/MS) was used to identify differentially expressed peptides in sera from 40 CHB patients (20 with S0G0-S1G1 and 20 with S3G3-S4G4). Ion pair quantification from differentially expressed peptides in a validation set of sera from 86 CHB patients was done with multiple reaction monitoring (MRM). RESULTS: 21 differentially represented peptide peaks were found through LC-MS/MS. Ion pairs generated from eleven of these peptides (m/z < 800) were quantified by MRM. Summed peak area ratios of 6 ion pairs from peptide m/z 520.3 (176.1, 353.7, 459.8, 503.3, 351.3, 593.1), which was identified as dihydroxyacetone kinase (DAK) fragment, decreased from mild to advanced stages of fibrosis or inflammation. Area Under Receiver Operating Characteristic Curves (AUROCs) of five ion models discriminating fibrosis degrees were 0.871 ~ 0.915 (S2-4 versus S0-1) and 0.804 ~ 0.924 (S3-4 versus S0-2). AUROCs discriminating inflammation grades were 0.840 ~ 0.902 (G2-4 versus G0-1) and 0.787 ~ 0.888 (G3-4 versus G0-2). The diagnostic power of these models provides improved sensitivity and specificity for predicting disease progression as compared to aspartate aminotransferase to platelet ratio index (APRI), FIB-4, Forn's index and serum DAK protein. CONCLUSIONS: The peptide fragment (m/z 520.3) of DAK is a promising biomarker to guide timing of antiviral treatment and to avoid liver biopsy in compensated CHB patients.

Circulating sphingosine-1-phosphate and erythrocyte sphingosine kinase-1 activity as novel biomarkers for early prostate cancer detection.

BACKGROUND: Current markers available for screening normal populations and for monitoring prostate cancer (PCa) treatment lack sensitivity and selectivity. Sphingosine-1-phosphate (S1P) is a circulating lipid second messenger involved in cell growth and migration, the immune response, angiogenesis, and malignant transformation. METHODS: Eighty-eight patients with localised, locally advanced, or metastatic PCa were recruited into this prospective single-centre study. Plasma S1P levels were measured and compared with age-matched controls with benign prostate hyperplasia (BPH) (n=110) or with young healthy males with the very small chance of having PCa foci (n=20). RESULTS: Levels of circulating S1P were significantly higher in healthy subjects (10.36 ± 0.69 pmol per mg protein, P<0.0001) and patients with BPH (9.39 ± 0.75, P=0.0013) than in patients with PCa (6.89 ± 0.58, ANOVA, P=0.0019). Circulating S1P levels were an early marker of PCa progression to hormonal unresponsiveness and correlated with prostate-specific antigen (PSA) levels and lymph node metastasis. During the course of the study, nine patients have died of PCa. Importantly, their circulating S1P levels were significantly lower (5.11 ± 0.75) than in the surviving patients (7.02 ± 0.22, n=79, P=0.0439). Our data suggest that the decrease in circulating S1P during PCa progression may stem from a highly significant downregulation of erythrocyte sphingosine kinase-1 (SphK1) activity (2.14 ± 0.17 pmol per mg protein per minute in PCa patients vs 4.7 ± 0.42 in healthy individuals, P<0.0001), which may be a potential mechanism of cancer-induced anaemia. CONCLUSION: This current study has provided a potential mechanism for cancer-related anaemia and the first evidence that plasma S1P and erythrocyte SphK1 activity are the potential markers for the diagnosis, monitoring, and predicating for PCa mortality.

Mevalonate kinase deficiency (hyper IgD syndrome with periodic fever)--different faces with separate treatments: two cases and review of the literature.

The hyperimmunoglobulinemia D syndrome (HIDS), so-called mevalonate kinase deficiency, is caused by recessive mutations in the gene encoding mevalonate kinase enzyme. HIDS is characterized by recurrent fever attacks of 3-7 days that begin in infancy and recur every 4-6 weeks. The febrile period is accompanied by lymphadenopathy, arthralgia, abdominal pain, diarrhea, aphthous ulcers, and varying degree of skin involvement. The course and severity of the disease may be quite different. There is no effective or proven therapy for HIDS. We report two cases with HIDS, which had separate clinical findings and treatment strategies.