Diagnostic performance of two-dimensional shear wave elastography and attenuation imaging for fibrosis and steatosis assessment in chronic liver disease.

PURPOSE: We investigated the diagnostic performance of two-dimensional shear wave elastography (2D-SWE) and attenuation imaging (ATI) in detecting fibrosis and steatosis in patients with chronic liver disease (CLD), comparing them with established methods. METHODS: In 190 patients with CLD, 2D-SWE and vibration-controlled transient elastography (VCTE) were used for liver stiffness measurement (LSM), and ATI and controlled attenuation parameter (CAP) were used for steatosis quantification. The correlations between these new and established methods were analyzed. RESULTS: Significant correlations were found between 2D-SWE and VCTE (r = 0.78, P < 0.001), and between ATI and CAP (r = 0.70, P < 0.001). Liver stiffness tended to be lower with 2D-SWE compared with that with VCTE, especially in cases with higher LSM, and ATI was less influenced by skin-capsular distance than CAP. Area under the receiver-operating characteristics curves (AUCs) and optimal cut-offs of 2D-SWE for diagnosing liver fibrosis stages F2, F3, and F4 were 0.73 (8.7 kPa), 0.79 (9.1 kPa), and 0.88 (11.6 kPa), respectively. The AUCs and optimal cut-offs of ATI for diagnosing hepatic steatosis grades S1, S2, and S3 were 0.91 (0.66 dB/cm/MHz), 0.80 (0.79 dB/cm/MHz), and 0.88 (0.86 dB/cm/MHz), respectively. A subgroup analysis of 86 patients with metabolic dysfunction-associated steatotic liver disease also demonstrated good performance for 2D-SWE and ATI. CONCLUSION: 2D-SWE and ATI performed comparably with conventional VCTE and CAP in evaluating CLD, offering reliable alternatives for diagnosing liver fibrosis and steatosis.

Comprehensive metabolic modulations of sphingolipids are promising severity indicators in COVID-19.

The COVID-19 pandemic, caused by SARS-CoV-2, has had a significant worldwide impact, affecting millions of people. COVID-19 is characterized by a heterogenous clinical phenotype, potentially involving hyperinflammation and prolonged tissue damage, although the exact underlying mechanisms are yet to be fully understood. Sphingolipid metabolites, which govern cell survival and proliferation, have emerged as key players in inflammatory signaling and cytokine responses. Given the complex metabolic pathway of sphingolipids, this study aimed to understand their potential role in the pathogenesis of COVID-19. We conducted a comprehensive examination of sphingolipid modulations across groups classified based on disease severity, incorporating a time-course in serum and urine samples. Several sphingolipids, including sphingosine, lactosylceramide, and hexosylceramide, emerged as promising indicators of COVID-19 severity, as validated by correlation analyses conducted on both serum and urine samples. Other sphingolipids, such as sphingosine 1-phosphate, ceramides, and deoxy-dihydroceramides, decreased in both COVID-19 patients and individuals with non-COVID infectious diseases. This suggests that these sphingolipids are not specifically associated with COVID-19 but rather with pathological conditions caused by infectious diseases. Our analysis of urine samples revealed elevated levels of various sphingolipids, with changes dependent on disease severity, potentially highlighting the acute kidney injury associated with COVID-19. This study illuminates the intricate relationship between disturbed sphingolipid metabolism, COVID-19 severity, and clinical factors. These findings provide valuable insights into the broader landscape of inflammatory diseases.

Body Fat Distribution and Left Atrial Reverse Remodeling After Catheter Ablation for Atrial Fibrillation.

Background: Emerging evidence suggests a pathophysiological link between obesity and atrial fibrillation (AF). However, the contribution of body fat distribution to left atrial (LA) remodeling and its reversibility remain unclear in nonobese AF patients. Objectives: The purpose of this study was to investigate the association of body fat distribution with LA size and reverse remodeling (LARR). Methods: In total, 116 nonobese patients with AF (88 men, age 63 ± 11 years) who underwent first catheter ablation (CA) were included. Body fat distribution was assessed with bioelectrical impedance, and body fat percentage (BF%) and central fat percentage (CF%) were calculated. Patients were categorized by body size metrics (body mass index [BMI] and waist-to-hip [W/H] ratio) and fat parameters (BF% and CF%). Echocardiography was performed before and 6 months after CA. Multivariable logistic regression was used to examine the association between the 4 metrics (ie, BMI, W/H ratio, BF%, and CF%) and a lack of LARR (<15% reduction or increase in the LA volume index). Results: Body size metrics and adiposity measures were not independently associated with baseline LA size. Six months after CA, the higher W/H ratio and CF% groups exhibited persistent LA enlargement compared to their counterparts (both P < 0.01). In the multivariable analysis, W/H ratio and CF% were associated with a lack of LARR (adjusted ORs of 3.86 and 2.81 per 0.10 and 10% increase, respectively, both P < 0.01). The combined assessment of CF% with W/H ratio provided complementary risk stratification for persistent LA enlargement. Conclusions: Central adiposity was associated with a lack of LARR after CA, highlighting the importance of assessing body fat distribution even in nonobese patients.

Sphingosine kinase 2 and p62 regulation are determinants of sexual dimorphism in hepatocellular carcinoma.

OBJECTIVE: Hepatocellular carcinoma (HCC) is the third leading cause of cancer mortality, and its incidence is increasing due to endemic obesity. HCC is sexually dimorphic in both humans and rodents with higher incidence in males, although the mechanisms contributing to these correlations remain unclear. Here, we examined the role of sphingosine kinase 2 (SphK2), the enzyme that regulates the balance of bioactive sphingolipid metabolites, sphingosine-1-phosphate (S1P) and ceramide, in gender specific MASH-driven HCC. METHODS: Male and female mice were fed a high fat diet with sugar water, a clinically relevant model that recapitulates MASH-driven HCC in humans followed by physiological, biochemical cellular and molecular analyses. In addition, correlations with increased risk of HCC recurrence were determined in patients. RESULTS: Here, we report that deletion of SphK2 protects both male and female mice from Western diet-induced weight gain and metabolic dysfunction without affecting hepatic lipid accumulation or fibrosis. However, SphK2 deficiency decreases chronic diet-induced hepatocyte proliferation in males but increases it in females. Remarkably, SphK2 deficiency reverses the sexual dimorphism of HCC, as SphK2-/- male mice are protected whereas the females develop liver cancer. Only in male mice, chronic western diet induced accumulation of the autophagy receptor p62 and its downstream mediators, the antioxidant response target NQO1, and the oncogene c-Myc. SphK2 deletion repressed these known drivers of HCC development. Moreover, high p62 expression correlates with poor survival in male HCC patients but not in females. In hepatocytes, lipotoxicity-induced p62 accumulation is regulated by sex hormones and prevented by SphK2 deletion. Importantly, high SphK2 expression in male but not female HCC patients is associated with a more aggressive HCC differentiation status and increased risk of cancer recurrence. CONCLUSIONS: This work identifies SphK2 as a potential regulator of HCC sexual dimorphism and suggests SphK2 inhibitors now in clinical trials could have opposing, gender-specific effects in patients.

Alzheimer's disease manifests abnormal sphingolipid metabolism.

Introduction: Alzheimer's disease (AD) is associated with disturbed metabolism, prompting investigations into specific metabolic pathways that may contribute to its pathogenesis and pathology. Sphingolipids have garnered attention due to their known physiological impact on various diseases. Methods: We conducted comprehensive profiling of sphingolipids to understand their possible role in AD. Sphingolipid levels were measured in AD brains, Cerad score B brains, and controls, as well as in induced pluripotent stem (iPS) cells (AD, PS, and control), using liquid chromatography mass spectrometry. Results: AD brains exhibited higher levels of sphingosine (Sph), total ceramide 1-phosphate (Cer1P), and total ceramide (Cer) compared to control and Cerad-B brains. Deoxy-ceramide (Deoxy-Cer) was elevated in Cerad-B and AD brains compared to controls, with increased sphingomyelin (SM) levels exclusively in Cerad-B brains. Analysis of cell lysates revealed elevated dihydroceramide (dhSph), total Cer1P, and total SM in AD and PS cells versus controls. Multivariate analysis highlighted the relevance of Sph, Cer, Cer1P, and SM in AD pathology. Machine learning identified Sph, Cer, and Cer1P as key contributors to AD. Discussion: Our findings suggest the potential importance of Sph, Cer1P, Cer, and SM in the context of AD pathology. This underscores the significance of sphingolipid metabolism in understanding and potentially targeting mechanisms underlying AD.

Development of an advanced liquid chromatography-tandem mass spectrometry measurement system for simultaneous sphingolipid analysis.

Mass spectrometry-based lipidomics approaches offer valuable tools for the detection and quantification of various lipid species, including sphingolipids. The present study aimed to develop a new method to simultaneously detect various sphingolipid species that applies to diverse biological samples. We developed and validated a measurement system by employing a single-column liquid chromatography-mass spectrometry system utilizing a normal-phase separation mode with positive ionization. The measurement system provided precision with a coefficient of variant below 20% for sphingolipids in all types of samples, and we observed good linearity in diluted serum samples. This system can measure the following sphingolipids: sphingosine 1-phosphate (S1P), sphingosine (Sph), dihydroS1P (dhS1P), dihydroSph (dhSph), ceramide 1-phosphate (Cer1P), hexosylceramide (HexCer), lactosylceramide (LacCer), dh-ceramide, deoxy-ceramide, deoxy-dh-ceramide, and sphingomyelin (SM). By measuring these sphingolipids in cell lysates where S1P lyase expression level was modulated, we could observe significant and dynamic modulations of sphingolipids in a comprehensive manner. Our newly established and validated measurement system can simultaneously measure many kinds of sphingolipids in biological samples. It holds great promise as a valuable tool for laboratory testing applications to detect overall modulations of sphingolipids, which have been proposed to be involved in pathogenesis processes in a series of elegant basic research studies.

Alterations in urinary ceramides, sphingoid bases, and their phosphates among patients with kidney disease.

Background: To avoid an invasive renal biopsy, noninvasive laboratory testing for the differential diagnosis of kidney diseases is a desirable goal. As sphingolipids are demonstrated to be involved in the pathogenesis of various kidney diseases, we investigated the possible usefulness of the simultaneous measurement of urinary sphingolipids for differentiating kidney diseases. Materials and methods: Residual urine specimens were collected from patients who had been clinically diagnosed with chronic glomerulonephritis (CGN), diabetic mellitus (DM), systemic lupus erythematosus (SLE), and arterial hypertension (AH). The urinary sphingolipids-CERs C16:0, C18:0, C18:1, C20:0, C22:0, and C24:0; sphingosine [Sph]; dihydrosphingosine; sphingosine 1-phosphate [S1P]; and dihydroS1P [dhS1P]-were measured by liquid chromatography-tandem mass spectrometry. Based on the results, machine learning models were constructed to differentiate the various kidney diseases. Results: The urinary S1P was higher in patients with DM than in other participants (P < 0.05), whereas dhS1P was lower in the CGN and AH groups compared with control participants (P < 0.05). Sph and dhSph were higher in patients with CGN, AH, and SLE than in those with control participants (P < 0.05). The urinary CERs were significantly higher in patients with CGN, AH, and SLE than in those with control participants (P < 0.05). As a results of constructing a machine learning model discriminating kidney diseases, the resulting diagnostic accuracy and precision were improved from 94.03% and 66.96% to 96.10% and 78.26% respectively, when the urinary CERs, Sph, dhSph, S1P, dhS1P, and their ratios were added to the models. Conclusion: The urinary CERs, sphingoid bases, and their phosphates show alterations among kidney diseases, suggesting their potential involvement in the development of kidney injury.

Genetic and biochemical analysis of severe hypertriglyceridemia complicated with acute pancreatitis or with low post-heparin lipoprotein lipase mass.

Severe hypertriglyceridemia is a pathological condition caused by genetic factors alone or in combination with environmental factors, sometimes leading to acute pancreatitis (AP). In this study, exome sequencing and biochemical analyses were performed in 4 patients with hypertriglyceridemia complicated by obesity or diabetes with a history of AP or decreased post-heparin LPL mass. In a patient with a history of AP, SNP rs199953320 resulting in LMF1 nonsense mutation and APOE rs7412 causing apolipoprotein E2 were both found in heterozygous form. Three patients were homozygous for APOA5 rs2075291, and one was heterozygous. ELISA and Western blot analysis of the serum revealed the existence of apolipoprotein A-V in the lipoprotein-free fraction regardless of the presence or absence of rs2075291; furthermore, the molecular weight of apolipoprotein A-V was different depending on the class of lipoprotein or lipoprotein-free fraction. Lipidomics analysis showed increased serum levels of sphingomyelin and many classes of glycerophospholipid; however, when individual patients were compared, the degree of increase in each class of phospholipid among cases did not coincide with the increases seen in total cholesterol and triglycerides. Moreover, phosphatidylcholine, lysophosphatidylinositol, and sphingomyelin levels tended to be higher in patients who experienced AP than those who did not, suggesting that these phospholipids may contribute to the onset of AP. In summary, this study revealed a new disease-causing gene mutation in LMF1, confirmed an association between overlapping of multiple gene mutations and severe hypertriglyceridemia, and suggested that some classes of phospholipid may be involved in the pathogenesis of AP.

Correlation between variant call accuracy and quality parameters in comprehensive cancer genomic profiling tests.

Background: Comprehensive genomic profiling (CGP) tests have been widely utilized in clinical practice. In this test, the variant list automatically output from the data analysis pipeline often contains false-positive variants, although the correlation between the quality parameters and prevalence of false-positive variants remains unclear. Methods: We analyzed 125 CGP tests performed in our laboratory. False-positive variants were manually detected via visual inspection. The quality parameters of both wet and dry processes were also analyzed. Results: Among the 125 tests, 52 (41.6%) required more than one correction of the called variants, and 21 (16.8%) required multiple corrections. A significant correlation was detected between somatic false-positive variants and quality parameters in the wet (ΔΔCq, pre-capture library peak size, pre-capture library DNA amount, capture library peak size, and capture library concentration) and dry processes (total reads, mapping rates, duplication rates, mean depth, and depth coverage). Capture library concentration and mean depth were strong independent predictors of somatic false-positive variants. Conclusions: We demonstrated a correlation between somatic false-positive variants and quality parameters in the CGP test. This study facilitates gaining a better understanding of CGP test quality management.

Cerebrospinal Fluid Lysophosphatidylcholine Species for Distinguishing Narrowing of the Lumbar Spine.

BACKGROUND: Reoperation, sometimes multiple, is common with progressively worse outcomes in patients with degenerative lumbar spine diseases. Lysophosphatidylcholine (LPC), a precursor of lysophosphatidic acid, in the cerebrospinal fluid (CSF) is a possible biomarker for neuropathic pain and discriminating neuropathic pain caused by lumbar spinal canal stenosis (LSCS) from other etiologies. This study aimed to explore this possible use of LPC species in the CSF. METHODS: Patients with LSCS (n = 137) and persistent spinal pain syndrome (n = 22) were subjected in this multi-site observational study. The CSF was collected by lumbar puncture. Using liquid chromatography-tandem mass spectrometry, we measured 6 LPC species, (16:0), (18:0), (18:1), (18:2), (20:4), and (22:6), in the CSF. We compared the LPC values between the groups and determined the cutoff levels that could efficiently discriminate the groups with high accuracy. RESULTS: The levels of all measured LPC species were significantly higher in the LSCS group than the persistent spinal pain syndrome group. Four LPC species demonstrated more than 0.80 area under the curve obtained from the receiver operating characteristic curve analysis. Although the specificity of cutoff levels for the 6 LPC species was low to moderate, their sensitivity was consistently high. CONCLUSIONS: The existing diagnostic protocols combining physical examinations and morphological imaging studies for lumbar spinal pain have limited sensitivity. Measuring LPC species in the CSF is a promising objective laboratory test and could be suitable for detecting the presence of lumbar spinal stenosis and can help indications for surgery.

Comprehensive Analysis of Metabolites in Postmortem Brains of Patients with Alzheimer's Disease.

BACKGROUND: Disturbed metabolism has been proposed as being involved in the pathogenesis of Alzheimer's disease (AD), and more evidence from human AD brains is required. OBJECTIVE: In this study, we attempted to identify or confirm modulations in the levels of metabolites associated with AD in postmortem AD brains. METHODS: We performed metabolomics analyses using a gas chromatography mass spectrometry system in postmortem brains of patients with confirmed AD, patients with CERAD score B, and control subjects. RESULTS: Impaired phosphorylation of glucose and elevation of several tricarboxylic acid (TCA) metabolites, except citrate, were observed and the degree of impaired phosphorylation and elevation in the levels of the TCA cycle metabolites were negatively and positively correlated, respectively, with the clinical phenotypes of AD. The levels of uronic acid pathway metabolites were modulated in AD and correlated positively with the amyloid-ß content. The associations of nucleic acid synthesis and amino acid metabolites with AD depended on the kinds of metabolites; in particular, the contents of ribose 5-phosphate, serine and glycine were negatively correlated, while those of ureidosuccinic acid and indole-3-acetic acid were positively modulated in AD. Comprehensive statistical analyses suggested that alterations in the inositol pathway were most closely associated with AD. CONCLUSIONS: The present study revealed many novel associations between metabolites and AD, suggesting that some of these might serve as novel potential therapeutic targets for AD.

Development of blood collection tubes for glucose measurement using adenosine 3-phosphate and sodium fluoride as glycolytic inhibitors.

BACKGROUND: Blood collection tubes with sodium fluoride (NaF) added as a glycolytic inhibitor are widely used for glucose measurement. However, the glycolytic inhibitory effects of NaF are insufficient, and decreases in glucose levels over time after blood collection have become a problem. METHODS: Blood from a volunteer collected using an NaF tube was used to compare the glycolysis inhibitory abilities of ATP and ADP. Blood samples from 10 volunteers were collected in NaF tubes and NaF tubes with added ATP (NaF-ATP tubes). The stability of glucose and haemoglobin (Hb)A1c after whole-blood storage from immediately after blood collection to 24 h later was compared. RESULTS: ATP and ADP had similar inhibitory effects on glycolysis, but ATP was selected as an additive for blood collection tubes because ADP was more haemolytic than ATP. We verified the ability of NaF blood collection tubes supplemented with ATP to inhibit glycolysis. Mean (± standard deviation) glucose levels (n=10) after storage for 24 h after blood collection decreased to -9.0 ± 2.7 mg/dL (-0.50 ± 0.15 mmol/L) in conventional NaF tubes. NaF-ATP(20) tubes with 20 mg (0.036 mmol) ATP added showed a reduced decrease, with a mean of -5.8 ± 2.9 mg/dL (-0.32 ± 0.16 mmol/L). NaF-ATP tubes also had no effect on HbA1c measurement. CONCLUSION: This study reports on a blood collection tube that enables the measurement of glucose and HbA1c. Based on the results of validation, we conclude that NaF-ATP tubes can reduce decreases in glucose over time in stored whole blood compared to conventional NaF tubes.

Understanding the modulations of glycero-lysophospholipids in an elastase-induced murine emphysema model.

BACKGROUND: Increasing evidence indicates that bioactive lipid mediators are involved in chronic obstructive pulmonary disease (COPD) pathogenesis. Recently, glycero-lysophospholipids, such as lysophosphatidic acid (LysoPA) and lysophosphatidylserine (LysoPS), have been recognized as significant inflammation-related lipid mediators. However, their association with COPD remains unclear. METHODS: We used an elastase-induced murine emphysema model to analyze the levels of lysophospholipids and diacyl-phospholipids in the lungs. Additionally, we assessed the expression of LysoPS-related genes and published data on smokers. RESULTS: In the early phase of an elastase-induced murine emphysema model, the levels of LysoPS and its precursor (phosphatidylserine [PS]) were significantly reduced, without significant modulations in other glycero-lysophospholipids. Additionally, there was an upregulation in the expression of lysoPS receptors, specifically GPR34, observed in the lungs of a cigarette smoke-exposed mouse model and the alveolar macrophages of human smokers. Elastase stimulation induces GPR34 expression in a human macrophage cell line in vitro. CONCLUSIONS: Elastase-induced lung emphysema affects the LysoPS/PS-GPR34 axis, and cigarette smoking or elastase upregulates GPR34 expression in alveolar macrophages. This novel association may serve as a potential pharmacological target for COPD treatment.

Evaluation of the fully automated urine particle analyzer UF-1500.

BACKGROUND AND AIMS: This study primarily assessed the performance of the UF-1500, the novel and compact model of the fully automated urine particle analyzer and evaluated its performance against the existing UF-5000 instrument. MATERIALS AND METHODS: A total of 648 residual urine specimens were randomly collected and examined using both the UF-1500 and UF-5000 instruments as well as manual microscopy. For each parameter, the concordance rates and detection accuracy of the UF-1500 against manual microscopy were compared with the UF-5000. RESULTS: The concordance rates between the UF-1500 and manual microscopy were 75.3%-98.5%. The UF-1500 concordance rates within one group agreement were observed to be >90%, for all parameters except for YLCs. The differences within one group agreement between the UF-1500 and manual microscopy were insignificant, in comparison to the UF-5000, with exceptions noted for ECs and YLCs. The sensitivity and specificity of the UF-1500 for RBCs, WBCs, Squa.ECs, and BACT exceeded 80%, while the positive predictive values of ECs and CASTs were below 70%. CONCLUSION: The UF-1500 exhibited a performance that was comparable to the existing instrument, the UF-5000, and was suitable to be introduced in clinical practice. For the samples with suspected false-positive or false-negative results, a manual microscopic examination is required for accurate testing.

Association between non-alcoholic fatty liver disease and subclinical left ventricular dysfunction in the general population.

Aims: Emerging evidence suggests an association between non-alcoholic fatty liver disease (NAFLD) and heart failure (HF). We investigated the relationship between NAFLD and left ventricular (LV) functional remodelling in a general population sample without overt cardiac and liver disease. Methods and results: We included 481 individuals without significant alcohol consumption who voluntarily underwent an extensive cardiovascular health check. The fatty liver index (FLI) was calculated for each participant, and NAFLD was defined as FLI ≥ 60. All participants underwent 2D transthoracic echocardiography; LV global longitudinal strain (LVGLS) was assessed with speckle-tracking analysis. Univariable and multivariable linear regression models were constructed to investigate the possible association between NAFLD and LVGLS. Seventy-one (14.8%) participants were diagnosed with NAFLD. Individuals with NAFLD exhibited larger LV size and LV mass index than those without NAFLD, although left atrial size and E/e' ratio did not differ between groups. Left ventricular global longitudinal strain was significantly reduced in participants with vs. without NAFLD (17.1% ± 2.4% vs. 19.5% ± 3.1%, respectively; P < 0.001). The NAFLD group had a significantly higher frequency of abnormal LVGLS (<16%) than the non-NAFLD group (31.0% vs. 10.7%, respectively; P < 0.001). Multivariable linear regression analysis demonstrated that higher FLI score was significantly associated with impaired LVGLS independent of age, sex, conventional cardiovascular risk factors, and echocardiographic parameters (standardized ß -0.11, P = 0.031). Conclusion: In the general population without overt cardiac and liver disease, the presence of NAFLD was significantly associated with subclinical LV dysfunction, which may partly explain the elevated risk of HF in individuals with NAFLD.

Upregulation of autotaxin by oxidative stress via Nrf2 activation: A novel insight into the compensation mechanism in preeclamptic placenta.

The response of autotaxin (ATX)-lysophosphatidic acid (LPA) signaling system to placental oxidative stress (OS) and its significance to preeclampsia were investigated. For this purpose, oxidative stress index (OSI) and ATX levels were measured in the serum of pregnant women with preeclampsia. The expression levels of ATX and LPA receptors were assessed in trophoblast cells under high OS and glucose deprivation/re-oxygenation (OGD/R) conditions, with particular emphasis on the antioxidative nuclear factor erythroid 2-related factor 2 (NRF2) pathway. The influence of ATX-LPA signaling on cell migration was also evaluated using the wound healing assay. ATX concentrations and OSI in the serum were found to be elevated in preeclamptic women. The serum ATX levels were also positively correlated with OSI. Trophoblast cells responded to OS by increasing ATX mRNA expression concomitantly with intranuclear translocation of Nrf2, whereas inhibition of Nrf2 activation reverted this effect. The ATX-LPA signaling pathway facilitated trophoblast cell motility after Nrf2 activation. In conclusion, OS accumulation in preeclamptic placenta may activate the ATX-LPA system in trophoblasts via the Nrf2 pathway to sustain trophoblast functionality.

Apolipoprotein M bound sphingosine 1-phosphate suppresses NETosis through activating S1P1 and S1P4.

The pleiotropic effects of high-density lipoprotein (HDL), including its protective properties against sepsis, are attributed to the sphingosine 1-phosphate and apolipoprotein M (ApoM) that are carried on the lipoproteins. In this study, we attempted to elucidate the possible mechanisms underlying the sepsis coagulopathic state by considering the modulation of NETosis. Our results revealed that in a lipopolysaccharide-induced sepsis mouse model, the levels of NETosis markers, such as plasma DNA and histone, were elevated in ApoM-knockout (KO) mice and attenuated in ApoM-overexpressing mice. In ApoM-KO mice, the survival rate decreased and the occurrence rates of coagulopathy and organ injury increased following the administration of histone. Treatment with a conditioned medium of ApoM-overexpressing cells attenuated the observed NETosis in HL-60S cells that differentiated into neutrophils and were inhibited through the suppression of S1P1 or S1P4. The attenuation of PKCδ and PKCα/ß by S1P1 and S1P4 activation may also be involved. In ApoM-overexpressing mice, coagulopathy and organ injuries were attenuated following an injection of histone; these effects were partially inhibited by S1P1, 3, S1P4, or S1P1 antagonists. Furthermore, the exogenous administration of ApoM protected ApoM-KO mice that were challenged with histone from developing NETosis. In conclusion, the ApoM/S1P axis protects against NETosis through the attenuation of PKC activation by S1P1 and S1P4. The development of drugs targeting the ApoM/S1P axis may be beneficial for the treatment of pathological conditions involving uncontrolled NETosis, such as sepsis.