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.

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.

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.

Comparison of the clinical performance of the Atyp.C parameter of the UF-5000 fully automated urine particle analyzer with that of microscopic urine sediment analysis.

a Objectives: Urinalysis is one of the most common laboratory screening tests to detect problems in the renal and urinary system; however, they cannot detect atypical cells (Atyp.Cs). The Sysmex UF-5000, a fully automated urine particle analyzer, can detect Atyp.Cs via its Atyp.C parameter. This study aimed to compare the clinical value of the Atyp.C parameter with that of urine sediment microscopy. b Method: A total of 471 leftover urine samples were submitted to the Department of Clinical Laboratory at the University of Tokyo Hospital for urinalysis by manual sediment microscopy examination and UF-5000 Atyp.C analysis. c Result: Of 471 submitted samples, 117 were positive for Atyp.Cs by urine sediment and 354 samples were negative. The histological subtypes of the Atyp.Cs included 105 cases of suspected urothelial carcinoma cells, 10 suspected squamous carcinoma cells, and 2 of suspected adenocarcinoma cells. The Atyp.C values for the Atyp.C-positive and -negative groups were 2.64 ± 0.69 and 0.38 ± 0.16, respectively. The optimal Atyp.C cutoff value determined by the receiver operating characteristic curve analysis was 0.4/µL. The area under the curve was 0.856, with a sensitivity of 79.5% and specificity of 85.1%. Atyp.C values of the UF-5000 showed high predictive performance for Atyp.C-positive specimens identified by urine sediment microscopy. d Conclusions: This study shows that a combination of UF-5000 analysis and microscopic examination of urine sediment improves Atyp.C detection in urine sediment analysis. These results suggest that Atyp.C measured by UF-5000 could be a useful screening parameter in routine testing of urine samples.

Genetic Polymorphisms of ENPP2 Are Possibly Associated with Pain Severity and Opioid Dose Requirements in Patients with Inflammatory Pain Conditions: Clinical Observation Study.

Autotaxin, encoded by the ENPP2 gene, is a known key element of neuropathic pain; however, its involvement in nociceptive pain processing remains unclear. We explored the associations between postoperative pain intensity, 24-h postoperative opioid dose requirements, and 93 ENNP2-gene single-nucleotide polymorphisms (SNPs) in 362 healthy patients who underwent cosmetic surgery using the dominant, recessive, and genotypic models. Next, we validated the associations between relevant SNPs on the one hand and pain intensity and daily opioid dosages on the other in 89 patients with cancer-related pain. In this validation study, a Bonferroni correction for multiplicity was applied on all relevant SNPs of the ENPP2 gene and their respective models. In the exploratory study, three models of two SNPs (rs7832704 and rs2249015) were significantly associated with postoperative opioid doses, although the postoperative pain intensity was comparable. In the validation study, the three models of the two SNPs were also significantly associated with cancer pain intensity (p < 0.017). Patients with a minor allele homozygosity complained of more severe pain compared with patients with other genotypes when using comparable daily opioid doses. Our findings might suggest that autotaxin is associated with nociceptive pain processing and the regulation of opioid requirements.

The Lysophospholipase PNPLA7 Controls Hepatic Choline and Methionine Metabolism.

The in vivo roles of lysophospholipase, which cleaves a fatty acyl ester of lysophospholipid, remained unclear. Recently, we have unraveled a previously unrecognized physiological role of the lysophospholipase PNPLA7, a member of the Ca2+-independent phospholipase A2 (iPLA2) family, as a key regulator of the production of glycerophosphocholine (GPC), a precursor of endogenous choline, whose methyl groups are preferentially fluxed into the methionine cycle in the liver. PNPLA7 deficiency in mice markedly decreases hepatic GPC, choline, and several metabolites related to choline/methionine metabolism, leading to various symptoms reminiscent of methionine shortage. Overall metabolic alterations in the liver of Pnpla7-null mice in vivo largely recapitulate those in methionine-deprived hepatocytes in vitro. Reduction of the methyl donor S-adenosylmethionine (SAM) after methionine deprivation decreases the methylation of the PNPLA7 gene promoter, relieves PNPLA7 expression, and thereby increases GPC and choline levels, likely as a compensatory adaptation. In line with the view that SAM prevents the development of liver cancer, the expression of PNPLA7, as well as several enzymes in the choline/methionine metabolism, is reduced in human hepatocellular carcinoma. These findings uncover an unexplored role of a lysophospholipase in hepatic phospholipid catabolism coupled with choline/methionine metabolism.

Hepatic phosphatidylcholine catabolism driven by PNPLA7 and PNPLA8 supplies endogenous choline to replenish the methionine cycle with methyl groups.

Choline supplies methyl groups for regeneration of methionine and the methyl donor S-adenosylmethionine in the liver. Here, we report that the catabolism of membrane phosphatidylcholine (PC) into water-soluble glycerophosphocholine (GPC) by the phospholipase/lysophospholipase PNPLA8-PNPLA7 axis enables endogenous choline stored in hepatic PC to be utilized in methyl metabolism. PNPLA7-deficient mice show marked decreases in hepatic GPC, choline, and several metabolites related to the methionine cycle, accompanied by various signs of methionine insufficiency, including growth retardation, hypoglycemia, hypolipidemia, increased energy consumption, reduced adiposity, increased fibroblast growth factor 21 (FGF21), and an altered histone/DNA methylation landscape. Moreover, PNPLA8-deficient mice recapitulate most of these phenotypes. In contrast to wild-type mice fed a methionine/choline-deficient diet, both knockout strains display decreased hepatic triglyceride, likely via reductions of lipogenesis and GPC-derived glycerol flux. Collectively, our findings highlight the biological importance of phospholipid catabolism driven by PNPLA8/PNPLA7 in methyl group flux and triglyceride synthesis in the liver.

Modulations of urinary lipid mediators in acute bladder cystitis.

Bioactive lipids, such as lysophospholipids, ceramides, and eicosanoids and related mediators, have been demonstrated to be involved in inflammation. We aimed to investigate the possible orchestral modulations of these bioactive lipids in human inflammation. We simultaneously measured the urinary levels of lysophospholipids, ceramides, and eicosanoids and related mediators by a liquid chromatography-mass spectrometry method in patients with cystitis and control subjects. The urinary levels of lysophosphatidylcholine, lysophosphatidylethanolamine, sphingosine 1-phosphate, ceramides, prostaglandin (PG)E2 and its metabolites represented by tetranor-PGEM, several oxylipins, DHA, and lysoPAF were higher in patients with cystitis. Urinary levels of some species of glycerolysophospholipids were highly positively correlated with those of other species of the same glycerolysophospholipids. Cluster analyses revealed that lysophosphatidylcholine was close to a PGE2 metabolite, lysophosphatidylethanolamine was close to DHA, and sphingosine 1-phosphate and ceramides were close to lysoPAF. The orchestral dynamism of the lipid mediators was observed in the urine of cystitis, suggesting the necessity for simultaneous investigation of lipid mediators for translational research.

Autotaxin is a potential link between genetic risk factors and immunological disturbances of plasmacytoid dendritic cells in systematic lupus erythematosus.

BACKGROUND: The importance of autotaxin, an enzyme that catalyzes lysophospholipid production, has recently been recognized in various diseases, including cancer and autoimmune diseases. Herein, we examined the role of autotaxin in systemic lupus erythematosus (SLE), utilizing data from ImmuNexUT, a comprehensive database consisting of transcriptome data and expression quantitative trait locus (eQTL) data of immune cells from patients with immune-mediated disorders. METHODS: Serum autotaxin concentrations in patients with SLE and healthy controls (HCs) were compared. The transcriptome data of patients with SLE and age- and sex-matched HCs were obtained from ImmuNexUT. The expression of ENPP2, the gene encoding autotaxin, was examined in peripheral blood immune cells. Next, weighted gene correlation network analysis (WGCNA) was performed to identify genes with expression patterns similar to ENPP2. The ImmuNexUT eQTL database and public epigenomic databases were used to infer the relationship between autotaxin and pathogenesis of SLE. RESULTS: Autotaxin levels were elevated in the serum of patients with SLE compared to HCs. Furthermore, the expression of ENPP2 was higher in plasmacytoid dendritic cells (pDCs) than in other immune cell subsets, and its expression was elevated in pDCs of patients with SLE compared to HCs. In WGCNA, ENPP2 belonged to a module that correlated with disease activity. This module was enriched in interferon-associated genes and included genes whose expression was influenced by single-nucleotide polymorphisms associated with SLE, suggesting that it is a key module connecting genetic risk factors of SLE with disease pathogenesis. Analysis utilizing the ImmuNexUT eQTL database and public epigenomic databases suggested that the increased expression of ENPP2 in pDCs from patients with SLE may be caused by increased expression of interferon-associated genes and increased binding of STAT3 complexes to the regulatory region of ENPP2. CONCLUSIONS: Autotaxin may play a critical role in connecting genetic risk factors of SLE to disease pathogenesis in pDCs.

Sphingosine 1-phosphate lyase facilitates cancer progression through converting sphingolipids to glycerophospholipids.

BACKGROUND: In addition to potent agonist properties for sphingosine 1-phosphate (S1P) receptors, intracellularly, S1P is an intermediate in metabolic conversion pathway from sphingolipids to glycerolysophospholipids (glyceroLPLs). We hypothesized that this S1P metabolism and its products might possess some novel roles in the pathogenesis of cancer, where S1P lyase (SPL) is a key enzyme. METHODS: The mRNA levels of sphingolipid-related and other cancer-related factors were measured in human hepatocellular carcinoma (HCC), colorectal cancer, and esophageal cancer patients' tumours and in their adjacent non-tumour tissues. Phospholipids (PL) and glyceroLPLs were measured by using liquid chromatography-tandem mass spectrometry (LC-MS/MS). In-vitro experiments were performed in Colon 26 cell line with modulation of the SPL and GPR55 expressions. Xenograft model was used for determination of the cancer progression and for pharmacological influence. RESULTS: Besides high SPL levels in human HCC and colon cancer, SPL levels were specifically and positively linked with levels of glyceroLPLs, including lysophosphatidylinositol (LPI). Overexpression of SPL in Colon 26 cells resulted in elevated levels of LPI and lysophosphatidylglycerol (LPG), which are agonists of GPR55. SPL overexpression-enhanced cell proliferation was inhibited by GPR55 silencing. Conversely, inhibition of SPL led to the opposite outcome and reversed by adding LPI, LPG, and metabolites generated during S1P degradation, which is regulated by SPL. The xenograft model results suggested the contribution of SPL and glyceroLPLs to tumour progression depending on levels of SPL and GPR55. Moreover, the pharmacological inhibition of SPL prevented the progression of cancer. The underlying mechanisms for the SPL-mediated cancer progression are the activation of p38 and mitochondrial function through the LPI, LPG-GPR55 axis and the suppression of autophagy in a GPR55-independent manner. CONCLUSION: A new metabolic pathway has been proposed here in HCC and colon cancer, SPL converts S1P to glyceroLPLs, mainly to LPI and LPG, and facilitates cancer development.

Role of Autotaxin in High Glucose-Induced Human ARPE-19 Cells.

Autotaxin (ATX) is an enzymatic with lysophospholipase D (lysoPLD) activity. We investigated the role of ATX in high glucose (HG)-induced human retinal pigment epithelial (ARPE-19) cells to explore the pathogenesis of diabetic retinopathy (DR). We performed a quantitative real-time polymerase chain reaction, Western blotting, immunocytochemistry, enzyme-linked immunosorbent assay, cell permeability assay, and transepithelial electrical resistance measurement in HG-induced ARPE-19 cells and compared their results with those of normal glucose and osmotic pressure controls. ATX expression and its lysoPLD activity, barrier function, and expression of vascular endothelial growth factor receptors VEGFR-1 and VEGFR-2 were downregulated, while fibrotic responses, cytoskeletal reorganization, and transforming growth factor-ß expression were upregulated, in the HG group. Our results suggest that HG induces intracellular ATX downregulation, barrier dysfunction, and fibrosis, which are involved in early DR and can be targeted for DR treatment.

Serum levels of apolipoprotein A-I and E are associated with postoperative delirium: A post hoc analysis.

Postoperative delirium is a common complication for elderly patients. Detection of phosphorylated neurofilament heavy subunit in the serum reflects axonal damage with postoperative delirium. Although it has been implicated that serum apolipoprotein levels might be associated with senile cognitive disorder, its role in the development of delirium has not been fully investigated. This study examined the association of apolipoproteins with delirium after surgery. This was a post hoc analysis of 117 patients who participated in a prospective observational study of delirium in patients undergoing cancer surgery. Patients were clinically assessed for delirium within the first 5 days of surgery. Serum levels of apolipoprotein A-I, B, and E were measured on postoperative day 3. Forty-one patients (35%) were clinically diagnosed with postoperative delirium. Serum levels of apolipoprotein A-I and B were increased in patients with delirium whereas those of apolipoprotein E were decreased. These changes in apolipoprotein A-I and E levels were associated with the presence of phosphorylated neurofilament heavy subunit in the serum, and were significantly associated with delirium (A-I: adjusted odds ratio [aOR], 6.238; 95% confidence interval [CI], 2.766-20.68; P < .0001; E: aOR, 0.253; 95% CI, 0.066-0.810; P = .0193). A combination of apolipoprotein A-I and E offers significant discrimination between delirium and nondelirium with high accuracy (area under the curve, 0.8899). Serum apolipoprotein A-I and E levels were associated with delirium and the presence of phosphorylated neurofilament heavy subunit in serum. Therefore, apolipoproteins might be useful biomarkers of postoperative delirium.

Understanding modulations of lipid mediators in cancer using a murine model of carcinomatous peritonitis.

BACKGROUND: Numerous studies have investigated the possible involvement of eicosanoids, lysophospholipids, and sphingolipids in cancer. We considered that comprehensive measurement of these lipid mediators might provide a better understanding of their involvement in the pathogenesis of cancer. In the present study, we attempted to elucidate the modulations of sphingolipids, lysophospholipids, diacyl-phospholipids, eicosanoids, and related mediators in cancer by measuring their levels simultaneously by a liquid chromatography-mass spectrometry method in a mouse model of carcinomatous peritonitis. METHODS: We investigated the modulations of these lipids in both ascitic fluid and plasma specimens obtained from Balb/c mice injected intraperitoneally with Colon-26 cells, as well as the modulations of the lipid contents in the cancer cells obtained from the tumor xenografts. RESULTS: The results were as follows: the levels of sphingosine 1-phosphate were increased, while those of lysophosphatidic acid (LysoPA), especially unsaturated long-chain LysoPA, tended to be increased, in the ascitic fluid. Our findings suggested that ceramides, sphingomyelin, and phosphatidylcholine, their precursors, were supplied by both de novo synthesis and from elsewhere in the body. The levels of lysophosphatidylserine (LysoPS), lysophosphatidylinositol, lysophosphatidylglycerol, and lysophosphatidylethanolamine were also increased in the ascitic fluid, while those of phosphatidylserine (PS), a precursor of LysoPS, were markedly decreased. The levels of arachidonic acid derivatives, especially PGE2-related metabolites, were increased, while the plasma levels of eicosanoids and related mediators were decreased. Comprehensive statistical analyses mainly identified PS in the ascitic fluid and eicosanoids in the plasma as having highly negative predictive values for cancer. CONCLUSIONS: The results proposed many unknown associations of lipid mediators with cancer, underscoring the need for further studies. In particular, the PS/LysoPS pathway could be a novel therapeutic target, and plasma eicosanoids could be useful biomarkers for cancer.

Urine sediment findings were milder in patients with COVID-19-associated renal injuries than in those with non-COVID-19-associated renal injuries.

BACKGROUND: Acute renal injury is an important complication of coronavirus disease 2019 (COVID-19). Both COVID-19-specific mechanisms, such as damage to the renal parenchyma by direct infection, and non-specific mechanisms, such as the pre-renal injury factors, have been proposed to be involved in COVID-19-associated renal injuries. In this study, we aimed to elucidate the characteristics of COVID-19-associated renal injuries, focusing mainly on urine sediment findings. METHODS: We compared the urine sediment findings and their associations with renal functions or urinary clinical parameters between subjects with COVID-19 and subjects without COVID-19 with acute renal injuries. RESULTS: We found that the number of urine sediment particles and the levels of N-acetyl-ß-D-glucosaminidase, α1-microglobulin, liver type fatty acid-binding protein, and neutrophil gelatinase-associated lipocalin were associated with the severity of COVID-19. In addition, we observed that the number of granular casts, epithelial casts, waxy casts, and urinary chemical marker levels were lower in the subjects with COVID-19 than subjects without COVID-19 with acute renal injuries when the subjects were classified according to their renal function. CONCLUSIONS: These results suggest that pre-renal injury factors might be largely involved in the pathogenesis of COVID-19-associated renal injuries compared with non-COVID-19-associated renal injuries arising from surgery or sepsis.

Isoform-Dependent Effects of Apolipoprotein E on Sphingolipid Metabolism in Neural Cells.

BACKGROUND: Sphingosine 1-phosphate (S1P) and ceramides have been implicated in the development of Alzheimer's disease. Apolipoprotein E (ApoE) isoforms are also involved in the development of Alzheimer's disease. OBJECTIVE: We aimed at elucidating the potential association of the ApoE isoforms with sphingolipid metabolism in the central nervous system. METHODS: We investigated the modulations of apolipoprotein M (apoM), a carrier of S1P, S1P, and ceramides in Apoeshl mice, which spontaneously lack apoE, and U251 cells and SH-SY5Y cells infected with adenovirus vectors encoding for apoE2, apoE3, and apoE4. RESULTS: In the brains of Apoeshl mice, the levels of apoM were lower, while those of ceramides were higher. In U251 cells, cellular apoM and S1P levels were the highest in the cells overexpressing apoE2 among the apoE isoforms. The cellular and medium contents of ceramides decreased in the order of the cells overexpressing apoE3 > apoE2 and increased in the cells overexpressing apoE4. In SH-SY5Y cells, apoM mRNA and medium S1P levels were also the highest in the cells overexpressing apoE2. The cellular contents of ceramides decreased in the order of the cells overexpressing apoE3 > apoE2 = apoE4 and those in medium decreased in the order of the cells overexpressing apoE3 > apoE2, while increased in the cells overexpressing apoE4. CONCLUSION: The modulation of apoM and S1P might partly explain the protective effects of apoE2 against Alzheimer's disease, and the modulation of ceramides might be one of the mechanisms explaining the association of apoE4 with the development of Alzheimer's disease.

Elevated neuron-specific enolase level is associated with postoperative delirium and detection of phosphorylated neurofilament heavy subunit: A prospective observational study.

BACKGROUND: Delirium is the most common central nervous system complication after surgery. Detection of phosphorylated neurofilament heavy subunit in the serum reflects axonal damage within the central cervous system and is associated with the severity of postoperative delirium. Neuron-specific enolase and S100 calcium-binding protein ß have been identified as possible serum biomarkers of postoperative delirium. This study examined the association of the levels of these markers with incidence of postoperative delirium and detection of phosphorylated neurofilament heavy subunit. METHODS: This study represents a post hoc analysis of 117 patients who participated in a prospective observational study of postoperative delirium in patients undergoing cancer surgery. Patients were clinically assessed for development of postoperative delirium within the first five days of surgery. Serum levels of phosphorylated neurofilament heavy subunit, neuron-specific enolase, and S100 calcium-binding protein ß levels were measured on postoperative day 3. RESULTS: Forty-one patients (35%) were clinically diagnosed with postoperative delirium. Neuron-specific enolase level (P < 0.0001) and the proportion of patients positive for phosphorylated neurofilament heavy subunit (P < 0.0001) were significantly higher in the group of patients with postoperative delirium. Neuron-specific enolase level discriminated between patients with and without clinically diagnosed postoperative delirium with significantly high accuracy (area under the curve [AUC], 0.87; 95% confidence interval [CI], 0.79-0.95; P < 0.0001). Neuron-specific enolase level was associated with incidence of postoperative delirium independently of age (adjusted odds ratio, 8.291; 95% Cl, 3.506-33.286; P < 0.0001). The AUC for the serum neuron-specific enolase level in detecting phosphorylated neurofilament heavy subunit was significant (AUC, 0.78; 95% CI, 0.66-0.90; P < 0.0001). CONCLUSION: Elevated serum neuron-specific enolase was associated with postoperative delirium independent of age as well as detection of phosphorylated neurofilament heavy subunit in serum. Serum neuron-specific enolase and phosphorylated neurofilament heavy subunit might be useful as biomarkers of postoperative delirium. TRIAL REGISTRATION: University Medical Information Network (UMIN) trial ID: UMIN000010329; https://clinicaltrials.gov/.

Epidemiological study using IgM and IgG antibody titers against SARS-CoV-2 in The University of Tokyo, Japan (UT-CATS).

INTRODUCTION: The worldwide pandemic of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has continued to date. Given that some of the patients with coronavirus disease 2019 (COVID-19) are asymptomatic, antibody tests are useful to determine whether there is a previous infection with SARS-CoV-2. In this study, we measured IgM and IgG antibody titers against SARS-CoV-2 in the serum of asymptomatic healthy subjects in The University of Tokyo, Japan. METHODS: From June 2020, we recruited participants, who were students, staff, and faculty members of The University of Tokyo in the project named The University of Tokyo COVID-19 Antibody Titer Survey (UT-CATS). Following blood sample collection, participants were required to answer an online questionnaire about their social and health information. We measured IgG and IgM titers against SARS-CoV-2 using iFlash-SARS-CoV-2 IgM and IgG detection kit which applies a chemiluminescent immunoassay (CLIA) for the qualitative detection. RESULTS: There were 6609 volunteers in this study. After setting the cutoff value at 10 AU/mL, 32 (0.48%) were positive for IgG and 16 (0.24%) for IgM. Of six participants with a history of COVID-19, five were positive for IgG, whereas all were negative for IgM. The median titer of IgG was 0.40 AU/mL and 0.39 AU/mL for IgM. Both IgG and IgM titers were affected by gender, age, smoking status, and comorbidities. CONCLUSIONS: Positive rates of IgG and IgM titers were relatively low in our university. Serum levels of these antibodies were affected by several factors, which might affect the clinical course of COVID-19.