Deficiency of Nardilysin in the Liver Reduces Serum Cholesterol Levels.

Nardilysin (NRDC) has been shown to be involved in post-translational histone modifications, in addition to enhancement in ectodomain shedding of membrane-anchored protein, which play significant roles in various pathophysiology, including glucose homeostasis, inflammatory diseases and cancer. The present study sought to determine roles of NRDC in the liver on lipid and lipoprotein metabolism. We established liver-specific NRDC deficient mice by use of NRD1 floxed mice and albumin promoter-Cre recombinase (Cre) transgenic mice, and found that their serum low-density lipoprotein (LDL) cholesterol levels were significantly lower than those in control littermate mice. In the liver, LDL receptor (LDLR) mRNA expression was significantly upregulated, while inducible degrader of LDLR (IDOL) and microsomal triglyceride transfer protein (MTP) mRNA expression was significantly downregulated, in liver-specific NRDC deficient mice. Hepatic cell-surface LDLR expression levels were significantly elevated and serum pro-protein convertase subtilisin-kexin type 9 (PCSK9) levels were significantly reduced in mice with hepatic NRDC deficiency. In cultured hepatocytes, NRDC deficiency significantly reduced secreted PCSK9 and increased cell-surface LDLR expression. On the other hand, NRDC overexpression in cultured hepatocytes significantly increased secreted PCSK9 and lowered cell-surface LDLR expression. Thus, NRDC in murine hepatocytes appears to play key roles in cholesterol homeostasis, although the precise molecular mechanisms remain to be determined.

Reduced Serum Cholesterol and Triglyceride Levels in a Choline-Deficient L-Amino Acid-Defined High-Fat Diet (CDAHFD)-Induced Mouse Model of Non-alcoholic Steatohepatitis (NASH).

Non-alcoholic fatty liver disease (NAFLD) or non-alcoholic seatohepatitis (NASH) is one of the major health problems world wide, because of increased abdominal obesity. To date, specific and effective medications to treat or prevent NAFLD/NASH have not been established. To identify appropriate molecular targets for that purpose, suitable animal models of NAFLD/NASH have been explored. A choline-deficient amino acid-defined high fat diet (CDAHFD)-induced mouse model of NASH has been developed. However, its relevance to human NASH, including serum lipid profiles, have not been clearly defined. In this study, we have revealed that mice fed CDAHFD showed significantly lowerd serum total cholesterol and triglyceride (TG) levels, in addition to reduced body weight (BW). Furthermore, hepatic microsomal triglyceride transfer protein (MTP) expression was significantly downregulated in CDAHFD-fed mice. Thus, the current CDAHFD-fed mouse model has points that are distinct from human NAFLD/NASH, in general, which is based upon abdominal obesity.

Association of Hypnotic Drug Use with Fall Incidents in Hospitalized Elderly Patients: A Case-Crossover Study.

We investigated whether use of hypnotic drugs, including benzodiazepine receptor agonists, as well as ramelteon and suvorexant are associated with fall incidents in elderly inpatients aged no less than 75 years, who were hospitalized at an acute care general hospital in Japan, between November 1st, 2016 and October 31st, 2017. Multivariate analysis results were reported as odds ratio (OR) with 95% confidence interval (CI). Following to a case-crossover study protocol, the time windows of the case and the control days were assigned to the day or the days, which are one day or 2-8 d before the fall incidents, respectively. In the enrolled 111 patients, the accumulated total available numbers of the cases and the control days were 111 and 554 patient days, respectively. Hypnotic drug use was significantly associated with fall incidents (OR: 2.85, 95% CI: 1.03-7.90, p = 0.04). Especially benzodiazepine receptor agonists (OR: 5.79, 95% CI: 1.52-22.1, p = 0.01) showed statistically significant association with fall incidents. In contrast, neither ramelteon (OR: 7.95, 95% CI: 0.72-87.9, p = 0.09) nor suvorexant (OR: 0.25, 95% CI: 0.06-1.06, p = 0.06) were significantly associated with fall incidents. Thus, benzodiazepine receptor agonists, but not ramelteon or suvorexant, showed significant association with fall incidents. Therefore, special care should be taken especially when benzodiazepine receptor agonists are administrated to elderly subjects. In contrast, fall risk may be much less in patients treated with ramelteon or suvorexant. These results could help us to conduct safer drug treatment for insomnia patients aged no less than 75 years.

Effects of Ramelteon and Other Sleep-Promoting Drugs on Serum Low-Density Lipoprotein and Non-high-density Lipoprotein Cholesterol: A Retrospective Comparative Pilot Study.

Melatonin has been suggested to play important roles in lipid metabolism as well as circadian rhythm; however, very few studies explored the effects of ramelteon, a selective melatonin receptor agonist, on serum lipid profiles. In this study effects of ramelteon on serum lipid profiles were explored, comparing to those of other sleep-promoting drugs including benzodiazepines and non-benzodiazepines, in patients with insomnia. We retrospectively reviewed medical charts of outpatients who were treated with ramelteon (8 mg/d) or other sleep-promoting drugs for no less than 8 weeks during the period between October 1st, 2011 and September 30th, 2014, and compared the changes in serum lipid profiles between the two groups. Patients with regular dialysis or malignant diseases treated with cytotoxic anti-cancer drugs, or whose lipid-lowering drugs were altered during the study period, were excluded. Among 365 or 855 outpatients treated with ramelteon or other sleep-promoting drugs, 35 or 46 patients, respectively, had complete serum low-density lipoprotein cholesterol (LDL-C) or non-high-density lipoprotein cholesterol (non-HDL-C) data. Serum LDL-C was significantly reduced from 103.1±4.4 to 94.6±4.2 mg/dL (8.2% reduction, p<0.05, n=31) in the ramelteon group, and was not significantly changed (p=0.23, n=40) in the other sleep-promoting drug group. Non-HDL-C was significantly decreased from 138.8±6.0 to 130.6±4.9 mg/dL (5.9% reduction, p<0.05, n=32) in the ramelteon group, and was not significantly altered (p=0.29, n=42) in the other sleep-promoting drug group. Ramelteon, but not other sleep-promoting drugs, specifically lowers serum LDL-C and non-HDL-C levels.

Matrix Metalloproteinase-9 as a Marker for Plaque Rupture and a Predictor of Adverse Clinical Outcome in Patients with Acute Coronary Syndrome: An Optical Coherence Tomography Study.

OBJECTIVES: The present study sought to clarify the relationship between matrix metalloproteinase-9 (MMP-9) levels and plaque morphology demonstrated by optical coherence tomography (OCT), and to examine their prognostic impacts in patients with acute coronary syndrome (ACS). METHODS: MMP-9 levels were measured for patients with ACS (n = 249). Among 249 patients, 120 with evaluable OCT images were categorized into patients with ruptured plaques (n = 65) and those with nonruptured plaques (n = 55) on the basis of culprit lesion plaque morphology demonstrated by OCT. RESULTS: MMP-9 levels on admission were significantly higher in the rupture group than in the nonrupture group (p = 0.029). Although creatine kinase-MB (CK-MB) on admission was comparable between the groups, peak CK-MB was higher in the rupture group than in the nonrupture group (p < 0.001). By receiver operating characteristic curve analysis, the optimal cut-off value of MMP-9 to detect ruptured plaques was 65.5 ng/ml (p = 0.029). There was a nonstatistically significant trend toward increased cardiac death at 2 years (5.9 vs. 1.0%, p = 0.059) in patients with high MMP-9 (≥65.5 ng/ml) compared to those with low MMP-9 (<65.5 ng/ml). CONCLUSIONS: MMP-9 can differentiate ACS with ruptured plaques from nonruptured plaques, and MMP-9 may be a valuable predictor of long-term cardiac mortality in patients with ACS reflecting plaque rupture.

Plasma soluble lectin-like oxidized low-density lipoprotein receptor-1 as a novel prognostic biomarker in patients with ST-segment elevation acute myocardial infarction.

BACKGROUND: Soluble lectin-like oxidized low-density lipoprotein receptor-1 (sLOX-1) level is a reliable prognostic biomarker in acute coronary syndrome. However, it is unclear whether its plasma level at acute phase is related to the long-term prognosis in patients with ST-segment elevation acute myocardial infarction (STEMI). METHODS AND RESULTS: We prospectively examined the relation between plasma sLOX-1 level on admission and prognosis in 153 consecutive STEMI patients admitted within 24 h of onset. Primary percutaneous coronary intervention was performed in 144 patients. The patients were divided into 2 groups by the median value (71 pg/ml) of plasma sLOX-1 level on admission [sLOX-1 level ≤71 pg/ml (n=77) and >71 pg/ml (n=76)], and were followed for median of 1,156 days. All-cause mortality and the combined endpoints of major adverse cardiovascular events (MACE) defined as cardiovascular mortality and recurrent MI were both significantly higher in patients with sLOX-1 values above median than in those below median (25.0% vs. 3.9%, P<0.001, and 19.4% vs. 6.5%, P=0.019 by log-rank test, respectively). Even after adjustment for confounders, a level of sLOX-1 above median was an independent predictor for all-cause mortality (hazard ratio (HR): 5.893; 95% confidence interval (CI): 1.665-20.854, P=0.006) and MACE (HR: 3.457; 95% CI: 1.164-10.270, P=0.030). CONCLUSIONS: Elevated plasma sLOX-1 level on admission independently predicts long-term all-cause mortality and MACE after STEMI.

Lectin-like oxidized low-density lipoprotein receptor 1 signal is a potent biomarker and therapeutic target for human rheumatoid arthritis.

OBJECTIVE: To determine whether lectin-like oxidized low-density lipoprotein (ox-LDL) receptor 1 (LOX-1) and the soluble form of LOX-1 (sLOX-1) are novel target molecules for the diagnosis and treatment of rheumatoid arthritis (RA). METHODS: Expression of ox-LDL and LOX-1 proteins in human RA synovium was evaluated by immunohistochemistry. Human RA fibroblast-like synoviocytes (FLS) were assessed for ox-LDL-induced expression of LOX-1 and ox-LDL-induced production of matrix metalloproteinase 1 (MMP-1) and MMP-3. Levels of sLOX-1 in the plasma and synovial fluid of patients with RA, compared with patients with osteoarthritis (OA), were determined by a specific chemiluminescence enzyme-linked immunoassay. In animal experiments, ox-LDL was injected into the knee joints of mice, with or without an anti-LOX-1 neutralizing antibody or sLOX-1, and the severity of arthritis was analyzed by histology and immunohistochemistry. RESULTS: Oxidized LDL and LOX-1 proteins were detected in the RA synovial tissue. Levels of MMP-1 and MMP-3 were enhanced by stimulation of RA FLS with ox-LDL, and the production of both MMPs was inhibited by blockade of the ox-LDL-LOX-1 interaction with the anti-LOX-1 neutralizing antibody or sLOX-1. Levels of sLOX-1 in the plasma and synovial fluid of RA patients were significantly higher than those in OA patients and healthy controls and were positively correlated with inflammation markers and the extent of RA disease activity. In the knees of mice, blockade of the ox-LDL-LOX-1 interaction suppressed arthritic changes and reduced the expression of MMP-3 induced by ox-LDL. CONCLUSION: These findings strongly indicate that sLOX-1 is a novel biomarker that may be useful for the diagnosis of RA and for the evaluation of disease activity in RA. Furthermore, the results suggest that LOX-1 may be a potent therapeutic target for RA.

SR-PSOX/CXCL16 plays a critical role in the progression of colonic inflammation.

BACKGROUND AND AIMS: Inflammatory bowel disease (IBD) is initiated and perpetuated by a dysregulated immune response to unknown environmental antigens such as luminal bacteria in genetically susceptible hosts. SR-PSOX/CXCL16, a scavenger receptor that binds phosphatidylserine and oxidised lipoprotein, has both phagocytic activity and chemotactic properties. The aim of this study was to investigate the role of SR-PSOX/CXCL16 in patients with IBD and experimental murine colitis. METHODS: The serum levels of SR-PSOX/CXCL16 were measured in patients with IBD. The roles of SR-PSOX/CXCL16 in phagocytosis of bacterial components and cytokine production by macrophages from wild-type (WT) and SR-PSOX/CXCL16 knockout (KO) mice were assessed. Colitis was induced by administering dextran sulfate sodium (DSS) to WT and SR-PSOX/CXCL16 KO mice. Colonic inflammation was analysed by clinical, histological and immunological parameters. Finally, the effect of a monoclonal antibody (mAb) to SR-PSOX/CXCL16 on DSS-induced colitis and trinitrobenzene sulfonic acid-induced colitis models was evaluated. RESULTS: Serum levels of SR-PSOX/CXCL16 correlated significantly with the disease activity of patients with IBD. Ex vivo experiments showed that SR-PSOX/CXCL16 was involved in both phagocytosis of bacterial antigens and the T helper 1 immune response through the production of interleukin 12 and interferon γ. In vivo murine experiments demonstrated the upregulated gene expression of SR-PSOX/CXCL16 in inflamed colonic tissues and the predominant expression of SR-PSOX/CXCL16 on macrophages. SR-PSOX/CXCL16 KO mice were less susceptible to colonic inflammation than were their WT littermates. Administration of SR-PSOX/CXCL16 mAb ameliorated the condition in the two different experimental colitis models. CONCLUSIONS: SR-PSOX/CXCL16 plays a critical role in colonic inflammation and could be a potential therapeutic target for patients with IBD.

Soluble lectin-like oxidized low-density lipoprotein receptor-1 as an early biomarker for ST elevation myocardial infarction: time-dependent comparison with other biomarkers: time-dependent comparison with other biomarkers.

BACKGROUND: The diagnostic sensitivity of myocardial necrosis markers, such as creatine kinase-MB (CK-MB), cardiac troponins, myoglobin and heart-type fatty acid-binding protein (H-FABP) for the earliest stage of ST-elevation myocardial infarction (STEMI), remains insufficient. We compared a new biomarker of plaque vulnerability (soluble lectin-like oxidized low-density lipoprotein receptor-1, sLOX-1) with other biomarkers at the earliest stage of STEMI. METHODS AND RESULTS: Plasma sLOX-1 levels were measured in 125 STEMI, 44 non-STEMI (NSTEMI) and 125 non-acute myocardial infarction (non-AMI) patients and were significantly (P < 0.0001) higher in the STEMI and NSTEMI than in the non-AMI patients (median, 25th and 75th percentiles: 241.0, 132.3 and 472.2 vs. 147.3, 92.9 and 262.4 vs. 64.3, 54.4 and 84.3 pg/ml, respectively). At the optimal cut-off value of 91.0 pg/ml, sLOX-1 discriminated STEMI from non-AMI with 89.6% sensitivity and 82.4% specificity. Time-dependent changes in sLOX-1, H-FABP, myoglobin, troponin T and CK-MB were analyzed in 27 STEMI patients. Elevated plasma sLOX-1 levels persisted for 24h after admission, whereas other markers were not elevated at the time of admission and peaked at ≥ 2h thereafter. The diagnostic sensitivity of sLOX-1, H-FABP, myoglobin, troponin T and CK-MB for STEMI upon admission (89 min after onset) was 93%, 78%, 70%, 56% and 33%, respectively. CONCLUSIONS: Plasma sLOX-1 diagnosed the early stages of STEMI more accurately than H-FABP, myoglobin, troponin T and CK-MB.

Soluble lectin-like oxidized LDL receptor-1 and high-sensitivity troponin T as diagnostic biomarkers for acute coronary syndrome. Improved values with combination usage in emergency rooms.

BACKGROUND: Although highly sensitive assays for troponin T (hs-TnT) have been developed, the sensitivity and specificity of hs-TnT for diagnosing acute coronary syndrome (ACS) remains imperfect. We evaluated the diagnostic value of a new biomarker of plaque vulnerability (soluble lectin-like oxidized low-density lipoprotein receptor-1, sLOX-1) as compared with hs-TnT in the emergency room (ER). METHODS AND RESULTS: Plasma sLOX-1 and serum hs-TnT levels were measured in 200 consecutive patients presenting with chest symptoms and ECG abnormalities in the ER (116 ST elevation ACS [STEACS], 44 non-ST elevation ACS [NSTEACS], 40 non-ACS). The non-ACS group consisted of patients with cardiovascular diseases such as coronary spastic angina pectoris, pulmonary thromboembolism, perimyocarditis and takotsubo cardiomyopathy. Levels of sLOX-1 and hs-TnT were significantly higher in STEACS and NSTEACS than in non-ACS patients. The receiver-operating characteristic (ROC) curves of sLOX-1 and hs-TnT for detecting ACS, using the non-ACS patients as negative references, showed that the area under the curve (AUC) values of sLOX-1 and hs-TnT were 0.769 and 0.739, respectively. In the lower hs-TnT (<0.0205ng/ml) subgroup, the AUC value of the ROC curve of sLOX-1 for detecting ACS was 0.869. CONCLUSIONS: The diagnostic value for ACS was comparable between sLOX-1 and hs-TnT, and the accuracy of ACS diagnosis appeared to improve when sLOX-1 and hs-TnT were measured in combination.

Matrix metalloproteinase-9 for the earliest stage acute coronary syndrome.

BACKGROUND: Matrix metalloproteinase-9 (MMP-9) is regarded as a biomarker of plaque rupture or vulnerability and is elevated in patients with acute coronary syndrome (ACS). The aim of the present study was to evaluate the diagnostic value of MMP-9 for early ACS (≤4h of onset) and late ACS (>4h after onset), compared with high-sensitivity troponin T (hs-TnT). METHODS AND RESULTS: MMP-9 and hs-TnT were measured in 200 patients with ST elevation ACS (STEACS; 115 early STEACS and 85 late STEACS patients), and 66 patients with non-ST elevation ACS (NSTEACS; 25 early NSTEACS and 41 late NSTEACS patients). Forty patients with stable angina pectoris (SAP) were enrolled as a control group. MMP-9 levels were significantly higher in patients with early STEACS (P<0.001), early NSTEACS (P<0.001), late STEACS (P<0.001) and late NSTEACS (P=0.025) than SAP. MMP-9 levels were significantly higher in patients with early STEACS (P=0.017) and early NSTEACS (P=0.034) than late STEACS and late NSTEACS, respectively. Levels of hs-TnT were significantly lower in patients with early STEACS (P<0.001) and early NSTEACS (P=0.007) than late STEACS and late NSTEACS, respectively. On receiver operating characteristic curve analysis, area under the curve of early STEACS, early NSTEACS, late STEACS and late NSTEACS was 0.880, 0.782, 0.790 and 0.648 for MMP-9, and 0.707, 0.725, 0.993 and 0.920 for hs-TnT, respectively. CONCLUSIONS: MMP-9 levels were elevated earlier than hs-TnT and had a higher diagnostic value for early ACS, but not for late ACS, reflecting plaque rupture or vulnerability.

Soluble lectin-like oxidized low-density lipoprotein receptor-1 predicts prognosis after acute coronary syndrome--a pilot study.

BACKGROUND: Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) is implicated in atherosclerotic plaque vulnerability. It is shed, in part, by proteases and released as soluble LOX-1 (sLOX-1), which is a specific and sensitive biomarker of acute coronary syndrome (ACS). The present study explored if sLOX-1 can also predict prognosis after ACS. METHODS AND RESULTS: ACS patients undergoing emergency percutaneous coronary intervention and measurement of circulating sLOX-1 were followed (median: 896 days). Among 94 patients, 13 had ACS recurrence or died (re-ACS/death group). None of age, sex, lipid profile or prevalence of diabetes, smoking or hypertension was significantly different between the re-ACS/death group and the event-free survival group. Circulating sLOX-1 levels, but not those of high-sensitivity C-reactive protein (hs-CRP) or troponin T (TnT), were significantly (P<0.005) higher in the re-ACS/death group than in the event-free survival group. Kaplan-Meier survival curves showed that ACS patients with sLOX-1 values in the highest quartile or tertile had more frequent and earlier ACS recurrence or death. Receiver-operating characteristic curves for prediction of re-ACS or death showed higher sensitivity and specificity for sLOX-1 (area under the curve for sLOX-1, hs-CRP and TnT: 0.764, 0.658 and 0.524, respectively). CONCLUSIONS: Circulating sLOX-1, a diagnostic biomarker of ACS, also predicts ACS recurrence or death.

[Molecular mechanisms of coronary atherosclerotic plaque formation and rupture].

Rupture or erosion of atherosclerotic plaques of the coronary artery followed by thrombus formation appears to be the major causes of acute coronary syndrome. Rupture-prone vulnerable or unstable plaques have been proposed as those with thin fibrous caps, large lipid cores, and enhanced inflammatory responses as well as oxidative and mechanical stresses. Angiotensin II, oxidized low-density lipoprotein(LDL), and its receptor lectin-like oxidized LDL receptor-1(LOX-1) appear to play key roles in atherosclerotic plaque vulnerability and rupture. In addition soluble LOX-1 can be a biomarker for acute coronary syndrome reflecting plaque vulnerability and rupture.

Targeting of lectinlike oxidized low-density lipoprotein receptor 1 (LOX-1) with 99mTc-labeled anti-LOX-1 antibody: potential agent for imaging of vulnerable plaque.

UNLABELLED: Lectinlike oxidized low-density lipoprotein (LDL) receptor 1 (LOX-1), a cell surface receptor for oxidized LDL, has been implicated in vascular cell dysfunction related to plaque instability, which could be a potential target for an atherosclerosis imaging tracer. In this study, we designed and prepared (99m)Tc-labeled anti-LOX-1 monoclonal IgG and investigated its usefulness as an atherosclerosis imaging agent. METHODS: Anti-LOX-1 monoclonal IgG and control mouse IgG2a were labeled with (99m)Tc after derivatization with 6-hydrazinonicotinic acid to yield (99m)Tc-LOX-1-mAb and (99m)Tc-IgG2a, respectively. Myocardial infarction-prone Watanabe heritable hyperlipidemic (WHHLMI) rabbits (atherosclerosis model) and control rabbits were injected intravenously with these probes, and in vivo planar imaging was performed. At 24 h after the injection, the aortas were removed, and radioactivity was measured. Autoradiography and histologic studies were performed with serial aortic sections. RESULTS: The level of (99m)Tc-LOX-1-mAb accumulation was 2.0-fold higher than the level of (99m)Tc-IgG2a accumulation in WHHLMI rabbit aortas, and the level of (99m)Tc-LOX-1-mAb accumulation in WHHLMI rabbit aortas was 10.0-fold higher than the level of (99m)Tc-LOX-1-mAb accumulation in control rabbit aortas. In vivo imaging clearly visualized the atherosclerotic aortas of WHHLMI rabbits. Autoradiography and histologic studies revealed that regional (99m)Tc-IgG2a accumulation was independent of the histologic grade of the lesions; however, regional (99m)Tc-LOX-1-mAb accumulation was significantly correlated with LOX-1 expression density and the vulnerability index. The highest level of (99m)Tc-LOX-1-mAb accumulation, expressed as {radioactivity in region of interest (Bq/mm(2))/[injected radioactivity (Bq)/animal body weight (g)]} x 10(2), was found in atheromatous lesions (3.8 +/- 1.1 [mean +/- SD]), followed in decreasing order by fibroatheromatous lesions (2.0 +/- 1.0), collagen-rich lesions (1.6 +/- 0.8), and neointimal lesions (1.4 +/- 0.7). CONCLUSION: The level of (99m)Tc-LOX-1-mAb accumulation in grade IV atheroma was higher than that in neointimal lesions or other, more stable lesions. Nuclear imaging of LOX-1 expression with (99m)Tc-LOX-1-mAb may be a useful means for predicting atheroma at high risk for rupture.

Mulberry leaf aqueous fractions inhibit TNF-alpha-induced nuclear factor kappaB (NF-kappaB) activation and lectin-like oxidized LDL receptor-1 (LOX-1) expression in vascular endothelial cells.

Mulberry (Morus Alba L., family Moraceae) leaf extracts have various biological effects including inhibition of oxidative modification of low-density lipoprotein (LDL), which is the major cause of atherosclerosis. Endothelial dysfunction elicited by oxidized LDL (Ox-LDL) has been implicated in atherogenesis. Lectin-like Ox-LDL receptor-1 (LOX-1), a cell-surface receptor for atherogenic Ox-LDL, appears to mediate Ox-LDL-induced inflammation, which may be crucial in atherogenesis. Previous studies revealed that expression of LOX-1 is highly inducible by proinflammatory stimuli, including tumor necrosis factor-alpha (TNF-alpha), lipopolysaccharide (LPS), and transforming growth factor-beta (TGF-beta). Therefore, we examined whether mulberry leaf aqueous fractions inhibit LOX-1 expression induced by proinflammatory stimuli. Pretreatment of cultured bovine aortic endothelial cells (BAECs) with mulberry leaf aqueous fractions inhibited TNF-alpha- and LPS-induced expression of LOX-1 at both protein and mRNA levels in a time- and concentration-dependent manner. In contrast, mulberry leaf aqueous fractions did not affect TGF-beta-induced LOX-1 expression. Furthermore, mulberry leaf aqueous fractions inhibited TNF-alpha-induced activation of nuclear factor-kappaB (NF-kappaB) and phosphorylation of inhibitory factor of NF-kappaB-alpha (IkappaB-alpha) in a time- and concentration-dependent fashion. Thus, mulberry leaf aqueous fractions suppress TNF-alpha- and LPS-induced LOX-1 gene expression, by inhibiting NF-kappaB activation.

Scavenger receptors for oxidized lipoprotein in age-related macular degeneration.

PURPOSE: The accumulation of macrophages is known to be involved in the pathogenesis of age-related macular degeneration (AMD), but the reasons why macrophages accumulate in AMD lesions have not been determined. Because the histopathology of AMD has some factors common with those of atherosclerosis, the authors hypothesized that macrophages accumulate to take up oxidized lipoproteins in the eyes of patients with AMD, as has been demonstrated in atherosclerosis. METHODS: Immunohistochemistry was performed on 10 surgically excised choroidal neovascular (CNV) membranes from eyes with AMD. An antibody against oxidized lipoprotein and antibodies against the scavenger receptors SR-PSOX and LOX-1 were used. Antibodies against cytokeratin, CD68, and von Willebrand factor were used to identify retinal pigment epithelium (RPE), macrophages, and vascular endothelial cells, respectively. RT-PCR was performed to detect the mRNAs of the scavenger receptors in the CNV membranes. RESULTS: Oxidized lipoproteins were immunohistochemically detected in the CNV membranes. Intense immunostaining was observed at the surface of the CNV membranes with the SR-PSOX antibody, whereas LOX-1 immunostaining was weak. Cells expressing scavenger receptors were found to be predominantly macrophages with a minority of RPE. Both SR-PSOX and LOX-1 mRNAs were detected in CNV membranes. CONCLUSIONS: Oxidized lipoproteins are present in AMD lesions. Macrophages and RPE in the CNV membranes express cell surface scavenger receptors for oxidized lipoproteins. These findings suggest that macrophages may accumulate to take up oxidized lipoproteins in AMD and that the control of oxidative stress and macrophage responses may therefore be potential treatments for AMD.

Oxidized phospholipids in the macula increase with age and in eyes with age-related macular degeneration.

PURPOSE: There is good evidence that oxidative stress is involved in the pathogenesis of age-related macular degeneration (AMD). Because AMD has risk factors and histopathology similar to with atherosclerosis, we hypothesized that oxidized phospholipids, which contribute to the pathogenesis of atherosclerosis, would accumulate in the eyes of AMD patients. To test this hypothesis, we investigated whether oxidized phospholipids were present in normal eyes and whether the level changed with increasing age. We then, we determined whether the levels of oxidized phospholipids were higher in eyes with AMD. METHODS: Twenty normal human donor eyes and six eyes with AMD were studied. Immunohistochemistry was performed on a tissue strip from the macular region using an antibody against oxidized phosphatidylcholine. Western blot analysis was also performed on proteins extracted from the posterior retina of donor eyes. The immunoreactivity of the specimens and the bands were quantified with NIH image software. RESULTS: Immunohistochemistry showed oxidized phosphatidylcholine was present in the photoreceptors and retinal pigment epithelium of the normal human macular area, and their levels increased with age. Eyes with AMD showed more intense immunoreactivity for oxidized phospholipids than age-matched normal eyes. CONCLUSIONS: These findings suggest that oxidative stress is involved in the pathogenesis of AMD possibly by oxidizing phospholipids in the photoreceptors as demonstrated in the arterial intima of patients with atherosclerosis. It is likely that controlling oxidation of phospholipids may be a potential treatment for AMD.

Serum soluble lectin-like oxidized low-density lipoprotein receptor-1 levels are elevated in acute coronary syndrome: a novel marker for early diagnosis.

BACKGROUND: Markers of cardiac injury, including troponin-T (TnT), are used to diagnose acute coronary syndrome (ACS); however, markers for plaque instability may be more useful for diagnosing ACS at the earliest stage. Lectin-like oxidized LDL receptor-1 (LOX-1) appears to play crucial roles in the pathogenesis of atherosclerotic plaque rupture and ACS onset. LOX-1 is released in part as soluble LOX-1 (sLOX-1) by proteolytic cleavage. METHODS AND RESULTS: We examined serum sLOX-1 levels in 521 patients, consisting of 427 consecutive patients undergoing coronary angiography, including 80 ACS patients, 173 symptomatic coronary heart disease patients, 122 patients with significant coronary stenosis without ischemia, and 52 patients without apparent coronary atherosclerosis plus 34 patients with noncardiac acute illness and 60 patients with noncardiac chronic illness. Time-dependent changes in sLOX-1 and TnT levels were analyzed in an additional 40 ACS patients. Serum sLOX-1 levels were significantly higher in ACS than the other groups and were associated with ACS as shown by multivariable logistic regression analyses. Given a cutoff value of 1.0 ng/mL, sLOX-1 can discriminate ACS from other groups with 81% and 75% of sensitivity and specificity, respectively. sLOX-1 can also discriminate ACS without ST elevation or abnormal Q waves and ACS without TnT elevation from non-ACS with 91% and 83% of sensitivity, respectively. Peak values of sLOX-1 in ACS were observed earlier than those of TnT. CONCLUSIONS: sLOX-1 appears to be a useful marker for early diagnosis of ACS.

A catheter-based intravascular radiation detector of vulnerable plaques.

UNLABELLED: Detection of vulnerable plaques before rupture is important in preventing acute coronary events such as myocardial infarction. Although therapeutic strategies such as percutaneous transluminal coronary angioplasty appear to prevent coronary occlusion and consequently may lead to improved prognosis in these patients, a method of detecting vulnerable plaques has not been established. A nuclear method that uses an intravascular radiation detector (IVRD) with the plaque-avid tracer (18)F-FDG is one of the most promising methods. The catheter-based IVRD consists of a catheter probe (a scintillator and flexible optic fibers), photomultipliers, a controller, and an automatic pullback unit and personal computer. A phantom study demonstrated that this detector was highly sensitive to (18)F and enabled the detection of (18)F point sources. However, details of the detection system in vivo remain unclear. METHODS: To evaluate vulnerable plaques in vivo, we investigated a canine femoral artery and coronary artery using this detector system. Our goal was to estimate the ability of this device to navigate through these arteries and to detect (18)F point sources fixed on their adventitia. RESULTS: In the study using a canine femoral artery, the IVRD could detect the point sources with good repeatability. In the study using an open-chest canine model, the catheter probe could easily be advanced into the left descending coronary artery, and the IVRD could detect target sources attached externally to the coronary artery (7- to 15-mm intervals) with good resolution. CONCLUSION: This newly developed catheter-based IVRD was able to detect, with good resolution, the slight radioactivity from (18)F point sources attached to the femoral artery and the coronary adventitia. These results show that catheter-based detection of coronary vulnerable plaques may be feasible.

Comparison of serum lipid management between elderly and non-elderly patients with and without coronary heart disease (CHD).

Serum lipid management in patients aged ≥ 75 has not been precisely explored. We, therefore, compared the serum lipid management between the two age groups with and without coronary heart disease (CHD). We, therefore, retrospectively reviewed medical charts of patients who were hospitalized in the departments of internal medicine during a period of 14 months. Serum lipid goal attainment was explored by applying the lipid goals for patients aged < 75 to those aged ≥ 75. In 1988 enrolled patients, 717 subjects (36.1%) were aged ≥ 75. Among them, 41.3% and 32.4% of the patients had CHD, 44.2% and 41.0% were primary prevention at high-risk, and 14.5% and 14.6% were primary prevention at moderate-risk in patients aged ≥ 75 and aged < 75, respectively. Serum LDL-C goal achievement rates in CHD were 66.9% and 65.0% in patients aged ≥ 75 and < 75, respectively (p = 0.334). In the primary prevention at high-risk, these rates were 73.5% and 63.3%, in patients aged ≥ 75 and < 75, respectively (p = 0.001). They were 77.9% and 58.1% in primary prevention at moderate-risk aged ≥ 75 and < 75, respectively (p < 0.001). In CHD, lipid-lowering medication subscription rates were significantly lower in patients aged ≥ 75 (60.1%) than those aged < 75 (73.8%, p < 0.001). In conclusion, in CHD, serum lipid goal attainment was comparable between the two age groups although the lipid-lowering drugs were less frequently prescribed in patients aged ≥ 75. Without CHD, it was significantly better in patients aged ≥ 75 than those aged < 75 although the lipid-lowering drug subscription rates were comparable between the two age groups.