Diagnostic Value of sLR11 and sIL-2R in the Cerebrospinal Fluid for Malignant Central Nervous System Lymphoma.

Objective We previously reported that patients with acute leukemia and malignant lymphoma (ML) demonstrated significantly increased serum soluble LR11 (sLR11) levels compared to normal controls. Accurately diagnosing ML of the central nervous system (CNS ML) using cytology is frequently difficult. Therefore, we evaluated the use of cerebrospinal fluid (CSF) sLR11 and soluble interleukin-2 receptor (sIL-2R) as diagnostic and treatment response markers for CNS ML. Methods We retrospectively evaluated the CSF results for CNS ML using clinical data at our institution, and then analyzed the usefulness of sLR11 and sIL-2R in CSF for both the diagnosis and as surrogate markers that reflect the therapeutic effect. Patients We enrolled patients with CNS ML who received intrathecal anticancer drugs between 2017 and 2023. We analyzed the sLR11 and sIL-2R levels in CSF and cytological malignant grades. We studied 22 patients, including 17 with central nervous system (CNS) clinical conditions and five who received prevention treatment. Results The CSF sLR11 levels were significantly and positively correlated with CSF sIL-2R levels. The CSF sLR11 and sIL-2R levels in patients with CNS ML were significantly higher than those in the prevention group. A receiver operating characteristic (ROC) curve analysis showed the cut-off value of sLR11 for CNS invasion to be 21.7 ng/mL. Moreover, the chemotherapy-responder group demonstrated significantly decreased CSF sLR11 and sIL-2R levels after treatment. Conclusion CSF sLR11 and sIL-2R of CSF were found to be useful biomarkers for the diagnostic and treatment response evaluation in patients with CNS ML.

Apolipoprotein M/sphingosine 1-phosphate protects against diabetic nephropathy.

Diabetic nephropathy remains a common cause of end-stage renal failure and its associated mortality around the world. Sphingosine 1-phosphate (S1P) is a multifunctional lipid mediator and binds to HDL via apolipoprotein M (ApoM). Since HDL has been reported to be epidemiologically associated with kidney disease, we attempted to investigate the involvement of the ApoM/S1P axis in the pathogenesis/progression of diabetic nephropathy. In type 2 diabetic patients, the serum ApoM levels were inversely correlated with the clinical stage of diabetic nephropathy. The decline in the eGFR over a 5-year observation period proceeded more rapidly in subjects with lower serum ApoM levels. In a mouse model of streptozotocin-induced diabetes, deletion of ApoM deteriorated the phenotypes of diabetic nephropathy: the urinary albumin and plasma creatinine levels increased, the kidneys enlarged, and renal fibrosis and thickening of the basement membrane progressed. On the other hand, overexpression of ApoM ameliorated these phenotypes. These protective effects of ApoM were partially inhibited by treatment with VPC23019, an antagonist of S1P1 and S1P3, but not by treatment with JTE013, an antagonist of S1P2. ApoM/S1P axis attenuated activation of the Smad3 pathway, while augmented eNOS phosphorylation through the S1P1 pathway. Moreover, ApoM/S1P increased the SIRT1 protein levels and enhanced mitochondrial functions by increasing the S1P content of the cell membrane, which might cause selective activation of S1P1. ApoM might be a useful biomarker for predicting the progression of diabetic nephropathy, and the ApoM/S1P-S1P1 axis might serve as a novel therapeutic target for preventing the development/progression of diabetic nephropathy.

Colon Cancer Metastasis to the Right Testis: Case Report and Review of Literature.

Introduction: A metastatic testicular tumor is uncommon. We report here a case of testicular metastasis associated with recurrent colorectal cancer. Case Presentation. A 75-year-old male was presented with right scrotum pain one year after undergoing a right hemicolectomy combined with resection of the small intestine and omentum for ascending colon cancer (pT4N0M0). Magnetic resonance imaging of the pelvis showed a 7.3 × 5.4 × 4.5 cm mass consisting of a cystic solid tumor. A right inguinal orchiectomy was performed and right testicular pain improved after surgery. Pathology results showed that the tumor was a metastatic adenocarcinoma. The patient subsequently died two months later due to progression of the colon cancer. Conclusion: Although colorectal cancer metastasis to the testis is very uncommon, it should be kept in mind in clinical situations, especially for older males with a testicular mass or discomfort.

Hepatocellular carcinoma diagnosis using a novel electrochemiluminescence immunoassay targeting serum IgM-free AIM.

BACKGROUND: Recent increases in the number of patients with non-alcoholic steatohepatitis (NASH) warrant the identification of biomarkers for early detection of hepatocellular carcinoma (HCC) associated with NASH (NASH-HCC). IgM-free apoptosis inhibitor of macrophage (AIM), which generally associates with IgM in blood and exerts its biological function by dissociation from IgM, may serve as an effective biomarker for NASH-HCC. Here, we established a fully automatic and high-throughput electrochemiluminescence immunoassay (ECLIA) to measure IgM-free AIM and investigated its efficacy in diagnosing NASH-HCC and viral HCC. METHODS: IgM-free AIM levels were measured in 212 serum samples from patients with, or without, HCC related to NASH, hepatitis B virus, and hepatitis C virus, using ECLIA. We also developed an ECLIA for measuring both IgM-free and IgM-bound AIM and investigated the existing form of AIM in blood by size-exclusion chromatography. RESULTS: IgM-free AIM levels were significantly higher in the HCC group than in the non-HCC group, regardless of the associated pathogenesis. Moreover, the area under the receiver operating curve for IgM-free AIM was greater than that for conventional HCC biomarkers, alpha-fetoprotein or des-γ-carboxy prothrombin, regardless of the cancer stage. ECLIA counts of IgM-free AIM derived from samples fractionated by size-exclusion chromatography were significantly higher in patients with NASH-HCC than in healthy volunteers and in patients with non-alcoholic fatty liver and NASH. CONCLUSIONS: Serum IgM-free AIM may represent a universal HCC diagnostic marker superior to alpha-fetoprotein or des-γ-carboxy prothrombin. Our newly established ECLIA could contribute to further clinical studies on AIM and in vitro HCC diagnosis.

Glycation of HDL Polymerizes Apolipoprotein M and Attenuates Its Capacity to Bind to Sphingosine 1-Phosphate.

AIM: Recently, it has been established that most of the pleiotropic effects of high-density lipoprotein (HDL) are attributed to sphingosine 1-phosphate (S1P), which rides on HDL via apolipoprotein M (ApoM). In subjects with diabetes mellitus, both the pleiotropic effects of HDL and its role in reverse cholesterol transport are reported to be impaired. To elucidate the mechanisms underlying the impaired pleiotropic effects of HDL in subjects with diabetes, from the aspects of S1P and ApoM. METHODS: The incubation of HDL in a high-glucose condition resulted in the dimerization of ApoM. Moreover, the treatment of HDL with methylglyoxal resulted in the modulation of the ApoM structure, as suggested by the results of western blot analysis, isoelectric focusing electrophoresis, and two-dimensional gel electrophoresis, which was reversed by treatment with anti-glycation reagents. RESULTS: The glycation of HDL resulted in impaired binding of the glycated HDL to S1P, and the S1P on glycated HDL degraded faster. In the case of human subjects, on the other hand, although both the serum ApoM levels and the ApoM content in HDL were lower in subjects with diabetes, we did not observe the polymerization of ApoM. CONCLUSIONS: Modulation of the quantity and quality of ApoM might explain, at least in part, the impaired functions of HDL in subjects with diabetes mellitus. ApoM might be a useful target for laboratory testing and/or the treatment of diabetes mellitus.

Temporary pacemaker insertion for severe bradycardia following pneumoperitoneum during robot-assisted radical prostatectomy: a case report.

BACKGROUND: Pneumoperitoneum to maintain a constant gas flow to assist various surgeries is known to cause severe bradycardia and has been linked to heart failure;; however, a recent study demonstrated that it is not linked to poorer surgical outcomes; accordingly, it does not require routine preventive measures. Thus, whether there is a link between sudden bradycardia development and surgical procedures is controversial. We report the case of severe bradycardia that occurred along with a complete atrioventricular block (CAVB) during peritoneum creation in robot-assisted radical prostatectomy (RARP). CASE PRESENTATION: A 72-year-old man presented at our hospital with prostate cancer and underwent RARP. After pneumoperitoneum, severe bradycardia and CAVB were observed; thus, the surgery was extended by inserting a temporary pacemaker (TPM). CONCLUSION: Because of the difficulty in performing emergency procedures in robot-assisted surgeries, the current case is reported to provide an awareness that surgeons should be cautious of the possible complication of bradycardia and CAVB during such operations, and thus should take steps necessary for managing induction of such conditions.

Protection Against Insulin Resistance by Apolipoprotein M/Sphingosine-1-Phosphate.

Subjects with low serum HDL cholesterol levels are reported to be susceptible to diabetes, with insulin resistance believed to be the underlying pathological mechanism. Apolipoprotein M (apoM) is a carrier of sphingosine-1-phosphate (S1P), a multifunctional lipid mediator, on HDL, and the pleiotropic effects of HDL are believed to be mediated by S1P. In the current study, we attempted to investigate the potential association between apoM/S1P and insulin resistance. We observed that the serum levels of apoM were lower in patients with type 2 diabetes and that they were negatively correlated with BMI and the insulin resistance index. While deletion of apoM in mice was associated with worsening of insulin resistance, overexpression of apoM was associated with improvement of insulin resistance. Presumably, apoM/S1P exerts its protective effect against insulin resistance by activating insulin signaling pathways, such as the AKT and AMPK pathways, and also by improving the mitochondrial functions through upregulation of SIRT1 protein levels. These actions of apoM/S1P appear to be mediated via activation of S1P1 and/or S1P3. These results suggest that apoM/S1P exerts protective roles against the development of insulin resistance.

A new method for measuring cholesterol efflux capacity uses stable isotope-labeled, not radioactive-labeled, cholesterol.

The incidence of cardiovascular events correlates inversely with cholesterol efflux capacity (CEC) more than with HDL-cholesterol level. The measurement of CEC is used to qualify cardiovascular disease risk and is conventionally performed with radioisotope (RI)-labeled cholesterol. Here, we established a CEC measurement technique using stable isotope-labeled cholesterol as an alternative, and we compared the new method with RI and fluorescence (boron dipyrromethene difluoride-cholesterol) methods in cells and in patient serum. We incubated J774 cells labeled with [d7]cholesterol ([d7]C) with patient serum depleted of apoB, and [d7]C extracted from the culture medium was quantified by liquid chromatography/quadrupole time-of-flight mass spectrometry. [d7]C efflux increased with greater apoB-depleted serum concentration and longer incubation time. The assay coefficient of variation (CV) of five consecutive measurements of three sets of samples ranged from 7.3% to 9.5%, and the interassay CV determined by measuring three samples four times ranged from 4.1% to 8.5%, both indicating good precision. We then measured CEC levels of 41 outpatients with serum HDL-cholesterol levels between 36 and 94 mg/dl (mean: 61.7 ± 18.0 mg/dl); in the presence of cAMP, we observed a significant, positive correlation between CEC levels determined with the stable isotope and RI methods that was stronger than the correlation between measurements obtained by the fluorescence and RI methods (r = 0.73, P < 0.0001 vs. r = 0.55, P < 0.001). Therefore, our stable isotope method can be considered useful as a non-RI method and thus deserves evaluation in future clinical studies.

Apolipoprotein M Protects Lipopolysaccharide-Treated Mice from Death and Organ Injury.

OBJECTIVE: High-density lipoprotein (HDL) has been epidemiologically shown to be associated with the outcome of sepsis. One potential mechanism is that HDL possesses pleiotropic effects, such as anti-apoptosis, some of which can be ascribed to sphingosine 1-phosphate (S1P) carried on HDL via apolipoprotein M (apoM). Therefore, the aim of this study was to elucidate the roles of apoM/S1P in the consequent lethal conditions of sepsis, such as multiple organ failure caused by severe inflammation and/or disseminated intravascular coagulation. METHODS AND RESULTS: In mice treated with lipopolysaccharide (LPS), both plasma apoM levels and the expression of apoM in the liver and kidney were suppressed. The overexpression of apoM improved the survival rate and ameliorated the elevated plasma alanine aminotransferase (ALT) and creatinine levels, while the knockout or knockdown of apoM deteriorated these parameters in mice treated with LPS. Treatment with VPC23019, an antagonist against S1P receptor 1 and 3, or LY294002, a PI3K inhibitor, partially reversed these protective properties arising from the overexpression of apoM. The overexpression of apoM inhibited the elevation of plasma plasminogen activator inhibitor-1, restored the phosphorylation of Akt, and induced anti-apoptotic changes in the liver, kidney and heart. CONCLUSION: These results suggest that apoM possesses protective properties against LPS-induced organ injuries and could potentially be introduced as a novel therapy for the severe conditions that are consequent to sepsis.

Vehicle-dependent Effects of Sphingosine 1-phosphate on Plasminogen Activator Inhibitor-1 Expression.

AIM: Sphingosine 1-phosphate (S1P) has been suggested to be a positive regulator of plasminogen activator inhibitor 1 (PAI-1) in adipocytes, while some studies are not consistent with this prothrombotic property of S1P. Since S1P is bound to apolipoprotein M (apoM) on HDL or to albumin in plasma, we compared the properties of these two forms on the PAI-1 induction. METHODS: We investigated the associations of S1P, apoM, and PAI-1 concentrations in the plasma of normal coronary artery (NCA), stable angina pectoris (SAP), and acute coronary syndrome (ACS) subjects (n=32, 71, and 38, respectively). Then, we compared the effects of S1P with various vehicles on the PAI-1 expression in 3T3L1 adipocytes. We also investigated the modulation of the PAI-1 levels in mice infected with adenovirus coding apoM. RESULTS: Among ACS subjects, the PAI-1 level was positively correlated with the S1P level, but not the apoM level. In adipocytes, S1P bound to an apoM-rich vehicle induced PAI-1 expression to a lesser extent than the control vehicle, while S1P bound to an apoM-depleted vehicle induced PAI-1 expression to a greater extent than the control vehicle in 3T3L1 adipocytes. Additionally, apoM overexpression in mice failed to modulate the plasma PAI-1 level and the adipose PAI-1 expression level. S1P bound to albumin increased PAI-1 expression through the S1P receptor 2-Rho/ROCK-NFκB pathway. CONCLUSION: S1P bound to albumin, but not to apoM, induces PAI-1 expression in adipocytes, indicating that S1P can exert different properties on the pathogenesis of vascular diseases, depending on its vehicle.

Induction of insulin secretion by apolipoprotein M, a carrier for sphingosine 1-phosphate.

BACKGROUNDS: High-density lipoprotein (HDL) has been proposed to enhance ß-cell functions. Clinical studies have suggested that apolipoprotein M (apoM), which rides mainly on HDL, is involved in diabetes; however, the underlying mechanism has not yet been elucidated. Recently, apoM was shown to be a carrier for sphingosine 1-phosphate (S1P), a bioactive lipid mediator. In the present study, we investigated the modulation of insulin secretion by apoM through the action of S1P. METHODS AND RESULTS: We overexpressed apoM in the livers of C57BL6 mice using adenovirus gene transfer and found that the blood glucose levels under ad libitum feeding conditions were lower in the apoM-overexpressing mice. While an insulin tolerance test revealed that insulin sensitivity was not significantly affected, a glucose tolerance test revealed that apoM-overexpressing mice had a better glucose tolerance because of enhanced insulin secretion, a phenomenon that was reversed by treatment with VPC 23019, an antagonist against S1P1 and S1P3 receptor. In vitro experiments with MIN6 cells also revealed that apoM-containing lipoproteins enhanced insulin secretion, which was again inhibited by VPC 23019. ApoM retarded the degradation of S1P, and an increase in Pdx1 expression, the attenuation of endoreticulum stress, and the phosphorylation of Akt, AmpK, and Erk were observed as possible underlying mechanisms for the effect of S1P, maintained at a high concentration by apoM, on the increase in insulin secretion. CONCLUSIONS: ApoM augmented insulin secretion by maintaining the S1P concentration under both in vivo and in vitro conditions.

Comparative genetic studies on the APRR5 and APRR7 genes belonging to the APRR1/TOC1 quintet implicated in circadian rhythm, control of flowering time, and early photomorphogenesis.

In Arabidopsis thaliana, a number of circadian-associated factors have been identified. Among those, TOC1 (TIMING OF CAB EXPRESSION 1) is believed to be a component of the central oscillator. TOC1 is a member of a small family of proteins, designated as Arabidopsis PSEUDO-RESPONSE REGULATORS (APRR1/TOC1, APRR3, APRR5, APRR7, and APRR9). Nonetheless, it is not very clear whether or not the APRR family members other than APRR1/TOC1 are also implicated in the mechanisms underlying the circadian rhythm. To address this issue further, here we characterized a set of T-DNA insertion mutants, each of which is assumed to have a severe lesion in each one of the quintet genes (i.e. APRR5 and APRR7). For each of these mutants (aprr5-11 and aprr7-11) we demonstrate that a given mutation singly, if not directly, affects the circadian-associated biological events simultaneously: (i) flowering time in the long-day photoperiod conditions, (ii) red light sensitivity of seedlings during the early photomorphogenesis, and (iii) the period of free-running rhythms of certain clock-controlled genes including CCA1 and APRR1/TOC1 in constant white light. These results suggest that, although the quintet members other than APRR1/TOC1 may not be directly integrated into the framework of the central oscillator, they are crucial for a better understanding of the molecular mechanisms underlying the Arabidopsis circadian clock.