XCR1+ conventional dendritic cell-induced CD4+ T helper 1 cell activation exacerbates cardiac remodeling after ischemic myocardial injury.

Cardiac remodeling has no established therapies targeting inflammation. CD4+ T-cell subsets have been reported to play significant roles in healing process after ischemic myocardial injury, but their detailed mechanisms of activation remain unknown. To explore immune reactions during cardiac remodeling, we applied a non-surgical model of coronary heart disease (CHD) induced by a high-fat diet (HFD-CHD) in SR-BI-/-/ApoeR61h/h mice. Flow cytometry analyses throughout the period of progressive cardiac dysfunction revealed that CD4+ T Helper 1 (Th1) cells were predominantly activated in T-cell subsets. Probucol was reported to attenuate cardiac dysfunction after coronary artery ligation model (ligation-MI) in rats. To determine whether probucol suppress cardiac remodeling after HFD-CHD, we treated SR-BI-/-/ApoeR61h/h mice with probucol. We found treatment with probucol in HFD-CHD mice reduced cardiac dysfunction, with attenuated activation of Th1 cells. RNA-seq analyses revealed that probucol suppressed the expression of CXCR3, a Th1-related chemokine receptor, in the heart. XCR1+ cDC1 cells, which highly expresses the CXCR3 ligands CXCL9 and CXCL10, were predominantly activated after HFD-CHD. XCR1+ cDC1 lineage skewing of pre-DC progenitors was observed in bone marrow, with subsequent systemic expansion of XCR1+ cDC1 cells after HFD-CHD. Activation of CXCR3+ Th1 cell and XCR1+ cDC1 cells was also observed in ligation-MI. Notably, post-MI depletion of XCR1+ cDC1 cells suppressed CXCR3+ Th1 cell activation and prevented cardiac dysfunction. In patient autopsy samples, CXCR3+ Th1 and XCR1+ cDC1 cells infiltrated the infarcted area. In this study, we identified a critical role of XCR1+ cDC1-activated CXCR3+ Th1 cells in ischemic cardiac remodeling.

Rivaroxaban Suppresses the Progression of Ischemic Cardiomyopathy in a Murine Model of Diet-Induced Myocardial Infarction.

AIM: A direct oral anti-coagulant, FXa inhibitor, has been applied to the clinical treatment of myocardial infarction (MI). Experimental studies in mice indicated that FXa inhibitors reduced atherosclerosis and prevented cardiac dysfunction after coronary ligation. These studies suggested that protease-activated receptor (PAR) 2, a major receptor of activated FX, may play an important role in atherosclerosis and cardiac remodeling. METHODS: The effects of a FXa inhibitor, rivaroxaban, were investigated in a new murine model of ischemic cardiomyopathy (ICM) using SR-BI KO/ApoeR61h/h mice (Hypo E mice) that developed MI by high-fat diet loading. RESULTS: Hypo E mice were fed rivaroxaban-containing (n=49) or control chow diets (n=126) after the induction of MI. The survival curve of the rivaroxaban-treated group 2 weeks after the induction of MI was improved significantly as compared with the non-treatment group (survival rate: 75.5% vs. 47.4%, respectively, p=0.0012). Echocardiography and the expression of BNP showed that rivaroxaban attenuated heart failure. Histological analyses revealed that rivaroxaban reduced aortic atherosclerosis and coronary occlusion, and markedly attenuated cardiac fibrosis. Rivaroxaban treatment decreased cardiac PAR2 levels and pro-inflammatory genes. In vitro, rivaroxaban application demonstrated the increase of cell viability against hypoxia in cardiac myocytes and the reduction of hypoxia-induced inflammation and fibrosis-related molecules in cardiac fibroblasts. The effects of the PAR2 antagonist against hypoxia-induced inflammation were comparable to rivaroxaban in cardiac fibroblasts. CONCLUSIONS: Rivaroxaban treatment just after MI in Hypo E mice prevented the progression of ICM by attenuating cardiac remodeling, partially through the suppression of the PAR2-mediated inflammatory pathway.

Widespread Coronary Dysfunction in the Absence of HDL Receptor SR-B1 in an Ischemic Cardiomyopathy Mouse Model.

Reduced clearance of lipoproteins by HDL scavenger receptor class B1 (SR-B1) plays an important role in occlusive coronary artery disease. However, it is not clear how much microvascular dysfunction contributes to ischemic cardiomyopathy. Our aim was to determine the distribution of vascular dysfunction in vivo in the coronary circulation of male mice after brief exposure to Paigen high fat diet, and whether this vasomotor dysfunction involved nitric oxide (NO) and or endothelium derived hyperpolarization factors (EDHF). We utilised mice with hypomorphic ApoE lipoprotein that lacked SR-B1 (SR-B1-/-/ApoER61h/h, n = 8) or were heterozygous for SR-B1 (SR-B1+/-/ApoER61h/h, n = 8) to investigate coronary dilator function with synchrotron microangiography. Partially occlusive stenoses were observed in vivo in SR-B1 deficient mice only. Increases in artery-arteriole calibre to acetylcholine and sodium nitroprusside stimulation were absent in SR-B1 deficient mice. Residual dilation to acetylcholine following L-NAME (50 mg/kg) and sodium meclofenamate (3 mg/kg) blockade was present in both mouse groups, except at occlusions, indicating that EDHF was not impaired. We show that SR-B1 deficiency caused impairment of NO-mediated dilation of conductance and microvessels. Our findings also suggest EDHF and prostanoids are important for global perfusion, but ultimately the loss of NO-mediated vasodilation contributes to atherothrombotic progression in ischemic cardiomyopathy.

Myocardial energy provision is preserved by increased utilization of glucose and ketone bodies in CD36 knockout mice.

AIMS: CD36 is an important transporter of long-chain fatty acids (LCFAs) in the myocardium. As we have reported previously, CD36-deficient patients demonstrate a marked reduction in myocardial uptake of (123)I-15-(p-iodophenyl)-(R, S)-methyl pentadecanoic acid (BMIPP), which is an analog of LCFAs, while myocardial (18)F-fluorodeoxy-glucose (FDG) uptake is increased. However, it has not been clarified whether energy provision is preserved in patients with CD36 deficiency. The aims of the current study were to investigate the myocardial uptake of glucose and alterations in myocardial metabolites in wild-type (WT) and CD36 knockout (KO) mice. METHODS AND RESULTS: High-resolution positron emission tomography (PET) demonstrated markedly enhanced glucose uptake in KO mouse hearts compared with those of WT mice in real-time. The myocardial protein expression of glucose transporter protein 1 (GLUT1) was significantly enhanced in KO mice compared to WT mice, whereas that of GLUT4 was not altered. While the myocardial expression of genes involved in fatty acid metabolism did not increase in KO mice, that of genes related to glucose utilization compensatorily increased in KO mice. The metabolomic analysis of cardiac tissues revealed that the myocardial concentrations of ATP and phosphocreatine were maintained, even in KO mice. The concentration of 3-hydroxybutyric acid and mRNA expression of hydroxybutyrate dehydrogenase in the heart were significantly higher in KO than in WT mice. CONCLUSION: These data suggest that high-energy phosphate might be preserved by the increased utilization of glucose and ketone bodies in CD36KO mouse hearts under conditions of deficient LCFA uptake.

Establishment of a novel murine model of ischemic cardiomyopathy with multiple diffuse coronary lesions.

OBJECTIVES: Atherosclerotic lesions of the coronary arteries are the pathological basis for myocardial infarction and ischemic cardiomyopathy. Progression of heart failure after myocardial infarction is associated with cardiac remodeling, which has been studied by means of coronary ligation in mice. However, this ligation model requires excellent techniques. Recently, a new murine model, HypoE mouse was reported to exhibit atherogenic Paigen diet-induced coronary atherosclerosis and myocardial infarction; however, the HypoE mice died too early to make possible investigation of cardiac remodeling. Therefore, we aimed to modify the HypoE mouse model to establish a novel model for ischemic cardiomyopathy caused by atherosclerotic lesions, which the ligation model does not exhibit. METHODS AND RESULTS: In our study, the sustained Paigen diet for the HypoE mice was shortened to 7 or 10 days, allowing the mice to survive longer. The 7-day Paigen diet intervention starting when the mice were 8 weeks old was adequate to permit the mice to survive myocardial infarction. Our murine model, called the "modified HypoE mouse", was maintained until 8 weeks, with a median survival period of 36 days, after the dietary intervention (male, n = 222). Echocardiography demonstrated that the fractional shortening 2 weeks after the Paigen diet (n = 14) significantly decreased compared with that just before the Paigen diet (n = 6) (31.4±11.9% vs. 54.4±2.6%, respectively, P<0.01). Coronary angiography revealed multiple diffuse lesions. Cardiac remodeling and fibrosis were identified by serial analyses of cardiac morphological features and mRNA expression levels in tissue factors such as MMP-2, MMP-9, TIMP-1, collagen-1, and TGF-ß. CONCLUSION: Modified HypoE mice are a suitable model for ischemic cardiomyopathy with multiple diffuse lesions and may be considered as a novel and convenient model for investigations of cardiac remodeling on a highly atherogenic background.

Deletion of progranulin exacerbates atherosclerosis in ApoE knockout mice.

AIMS: Progranulin (PGRN) is a multifunctional protein known to be involved in inflammation. However, the relation between PGRN and atherosclerosis remains elusive. The aim of this study was to define the role of PGRN in the development of atherosclerosis. METHODS AND RESULTS: First, we checked the expression levels of PGRN in human atherosclerotic plaques. Immunohistochemical analysis showed that PGRN is strongly expressed in foam cells of atherosclerotic plaques. We also found that PGRN is expressed more abundantly in macrophages than in the smooth muscle cells of atherosclerotic lesions in ApoE(-/-) mice fed a high-fat diet for 12 weeks. Next, PGRN(-/-)ApoE(-/-) mice were generated to investigate the effect of PGRN on the development of atherosclerosis. PGRN(-/-)ApoE(-/-) mice exhibited severe atherosclerotic lesions compared with PGRN(+/+)ApoE(-/-) mice, despite their anti-atherogenic lipid profile. These results are partly due to enhanced expression of inflammatory cytokines, adhesion molecules, and decreased expression of endothelial nitric oxide synthase. In addition, lack of PGRN leads to accumulate excessive cholesterol in the macrophages and alter HDL-associated proteins. CONCLUSION: PGRN seems to be involved in the pathogenesis of atherosclerosis, possibly by various anti-atherogenic effects, including modulation of local and/or systemic inflammation.

Apolipoprotein B-48 to triglyceride ratio is a novel and useful marker for detection of type III hyperlipidemia after antihyperlipidemic intervention.

AIM: Remnant lipoproteins are atherogenic and are accumulated in patients with type III hyperlipidemia (HL). Although type III HL is diagnosed by phenotyping apolipoprotein (apo) E, this procedure is time-consuming and inconvenient for routine clinical use. Clinical indices for screening type III HL in untreated HL patients have been proposed; however, in clinical settings, HL patients are promptly treated with lipid-lowering agents without diagnosing the underlying cause. We investigated whether existing clinical indices for screening type III HL as well as the apo B-48/triglyceride (TG) ratio, which was suggested to be related to the accumulation of small chylomicron (CM) remnants, are useful after the initiation of lipid-lowering therapies. METHODS: In 25 normolipidemic subjects and 191 treated HL patients (type I, n =6; IIa, 62; IIb, 66; III, 12; IV, 22; and V, 23) from Osaka University Hospital and related hospitals, fasting low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), TG, and apolipoproteins were measured and clinical indices were evaluated statistically. RESULTS: Apo B-48 levels were significantly higher in patients with type I, III, and V HL, and TG levels were significantly higher in patients with type I and V HL. The apo B-48/TG ratio was significantly higher only in patients with type III HL compared with other types of HL (p<0.001), and was statistically significant among the other clinical indices (AUC-ROC value, 0.895; cut-off value, 0.110). CONCLUSION: The apo B-48/TG ratio is a novel and useful marker for detecting type III HL even after the initiation of lipid-lowering interventions.

Effect of probucol on antioxidant properties of HDL in patients with heterozygous familial hypercholesterolemia.

AIM: High density lipoprotein (HDL) has multi-antiatherogenic effects such as antioxidation and anti-inflammation, in addition to being a key mediator of reverse cholesterol transport. Probucol, known as a lipid lowering drug, is also a potent antioxidant, but it decreases serum HDL cholesterol (HDL-C) levels. To elucidate the effect of probucol on antioxidant properties of HDL, we investigated the function of HDL derived from patients with heterozygous familial hypercholesterolemia (FH) who have been treated with probucol. METHODS AND RESULTS: Probucol-treated FH patients (n=21) showed a 47% reduction of serum HDL-C levels compared to probucol-untreated FH patients (n=15). High performance liquid chromatography (HPLC) analysis revealed that probucol diminished HDL particle size compared to the non-treated group. Antioxidant capacity of HDL was evaluated by its effect to protect reference LDL from oxidation induced in the presence of an oxidizing agent, AAPH. The HDL derived from the probucol-treated group demonstrated a significantly prolonged time to start oxidation by 112%, decreased the maximum oxidation rate by 14%, and lowered the maximum concentration of conjugated dienes formation by 15%. Furthermore, HDL-associated paraoxonase 1 (PON1) activity, but not platelet-activating factor acetyl-hydrolase (PAF-AH) correlated with these measurements of HDL anti-oxidative activity. Treatment with probucol in vitro and inhibition of PON1 activity demonstrated that probucol in HDL particles and increase of PON1 activity might largely contribute to the increase of HDL anti-oxidative activity. CONCLUSION: Probucol reduced HDL-C levels and HDL particle size in patients with heterozygous FH, while it concomitantly enhanced HDL anti-oxidative properties, possibly through increasing PON1 activity.

Serum adiponectin level is correlated with the size of HDL and LDL particles determined by high performance liquid chromatography.

OBJECTIVE: Adiponectin (APN) improves insulin resistance and prevents atherosclerosis, and HDL removes cholesterol from atherosclerotic lesions. We have demonstrated that serum HDL-cholesterol (HDL-C) and APN concentrations are positively correlated and that APN accelerates reverse cholesterol transport (RCT) by increasing HDL synthesis in the liver and cholesterol efflux from macrophages. We previously reported that APN reduced apolipoprotein (apo) B secretion from the liver. It is well-known that insulin resistance influences the lipoprotein profile. In this study, we investigated the clinical significance of APN levels and insulin resistance in lipoprotein metabolism. MATERIAL/METHOD: We investigated the correlation between serum APN concentration, HOMA-R, the lipid concentrations and lipoprotein particle size by high-performance liquid chromatography (HPLC) in 245 Japanese men during an annual health checkup. RESULTS: Serum APN level was positively correlated with the cholesterol content in large LDL and HDL particles, but inversely correlated with the cholesterol content in large VLDL and small LDL particles. HOMA-R was negatively correlated with the cholesterol content in large LDL and HDL particles and positively correlated with the cholesterol content in large VLDL and small LDL particles. By multivariate analysis, APN was correlated with the particle size of LDL-C and HDL-C independently of age, BMI and HOMA-R. CONCLUSIONS: APN may be associated with the formation of both HDL and LDL particles, reflecting the enhancement of RCT and the improvement in TG-rich lipoprotein metabolism and insulin resistance.

Establishment of chemiluminescence enzyme immunoassay for apolipoprotein B-48 and its clinical applications for evaluation of impaired chylomicron remnant metabolism.

BACKGROUND: Apolipoprotein B-48 (apoB-48) is a constituent of chylomicron remnants synthesized in the small intestines. The serum concentration of apoB-48 at fasting has been reported to be a marker of postprandial hyperlipidemia, a presumed risk factor for atherosclerosis. METHODS: We evaluated the basal performance of a recently developed chemiluminescent enzyme immunoassay (CLEIA). We also examined the correlations between serum apoB-48 concentrations and other lipid concentrations or life style patterns, including smoking and drinking. We analyzed the data of 273 clinical samples by multiple regression analysis to examine the influence of other serum lipid values, age, sex, smoking, drinking status and BMI on serum apoB-48 values. RESULTS: Within-run and between-run precision was obtained with 1.7-2.7% and 1.2-7.3%, respectively. The correlativity of enzyme-linked immunosorbent assay was correlation coefficient r=0.953, and regression y=1.02×-1.59. Serum apoB-48 concentrations were higher in males than in females, and were correlated with the status of smoking as well as with remnant-like particle-cholesterol (RLP-C) concentrations. Patients with the metabolic syndrome showed higher values of serum apoB-48 compared with control subjects. CONCLUSION: Serum apoB-48 measurement by CLEIA was satisfactory for clinical use to assess abnormalities in the chylomicron remnant metabolism.

Patients with CD36 deficiency are associated with enhanced atherosclerotic cardiovascular diseases.

AIM: The clustering of dyslipidemia, impaired glucose tolerance and hypertension increases the morbidity and mortality from cardiovascular events. A class B scavenger receptor, CD36, is a receptor for oxidized LDL and a transporter of long-chain fatty acids. Because of the impaired uptake of oxidized LDL in CD36-deficient macrophages and from the results of CD36 knockout mice, CD36 deficiency (CD36-D) was supposed to be associated with reduced risks for coronary artery disease (CAD); however, CD36-D patients are often accompanied by a clustering of coronary risk factors. The current study aimed to investigate the morbidity and severity of cardiovascular diseases in CD36-D patients. METHODS: By screening for CD36 antigen on platelets and monocytes using FACS or the absent myocardial accumulation of 123I-BMIPP by scintigraphy, 40 patients with type I CD36-D were collected, the morbidity of CAD and their features of atherosclerotic cardiovascular diseases were observed. Screening for CD36-D in both CAD patients (n = 319) and healthy subjects (n = 1,239) were underwent. RESULTS: The morbidity of CAD was significantly higher in CD36-D patients than in the general population; 50% of patients (20 out of 40) had CAD identified by BMIPP scintigraphy and 37.5% (3 out of 8) by FACS screening, respectively. Three representative CD36-D cases demonstrated severe CAD and atherosclerosis. The frequency of CD36-D was three times higher in CAD patients than in healthy subjects (0.9% vs 0.3%, p < 0.0001). CONCLUSION: The morbidity of CAD is significantly higher in CD36-D patients suffering from severe atherosclerosis, implying that the status of CD36-D might be atherogenic.

Fasting serum apolipoprotein B-48 can be a marker of postprandial hyperlipidemia.

AIM: Postprandial hyperlipidemia (PH) is thought to be caused by the impaired postprandial metabolism of triglycerides (TG)-rich lipoproteins in both endogenous and exogenous pathways; however, there is no consensus. It is difficult to estimate the presence of PH without performing a time-consuming oral fat loading (OFL) test, so postprandial lipoprotein metabolism was analyzed by measuring the postprandial levels of apolipoprotein (apo) B-48 and apo B-100, and the correlation between postprandial TG increase and fasting apoB-48 levels was assessed to establish a good marker of PH without performing an OFL test. METHODS: Ten male normolipidemic subjects were loaded with a high-fat (HF, 1045 kcal) or standard (ST, 566 kcal) meal, and the lipids, apolipoproteins and lipoprotein profiles were analyzed after each meal. RESULTS: TG, apo B-48, remnant-like particles (RLP)-cholesterol and RLP-TG levels were increased and their levels were significantly higher after intake of the HF meal than the ST meal; however, there was no postprandial increase in apo B-100 and LDL-C levels. Postprandial increases in TG levels of CM, VLDL, LDL and HDL were significantly higher after intake of the HF meal than the ST meal. Fasting apo B-48 levels were strongly correlated with the incremental area under the curve of TG after intake of the HF meal, but not the ST meal. CONCLUSION: Postprandial TG increase was mainly due to increased CM and CM-R, but not VLDL. Measurement of fasting serum apo B-48 may be a simple and useful method for assessment of the existence of PH.

Serum apolipoprotein B-48 levels are correlated with carotid intima-media thickness in subjects with normal serum triglyceride levels.

BACKGROUND: Postprandial hyperlipidemia (PPHL) is an independent risk factor for coronary heart disease (CHD) which is based on the accumulation of chylomicrons (CM) and CM remnants containing apolipoprotein B-48 (apoB-48). Since atherosclerotic cardiovascular diseases are frequently observed even in subjects with normal serum triglyceride (TG) level, the correlation between fasting apoB-48 containing lipoproteins and carotid intima-media thickness (IMT) was analyzed in subjects with normal TG levels. METHODS: From subjects who took their annual health check at the Osaka Police Hospital (n=245, male), one-hundred and sixty-four male subjects were selected to take part in this study; the excluding factors were: systolic blood pressure ≥ 140 mmHg, intake of antihypertensive or antihyperlipidemic drugs, or age >65 years. The association between biochemical markers and IMT was analyzed and independent predictors of max-IMT were determined by multiple regression analysis in all subjects and in groups N-1 (TG<100mg/dl, n=58), N-2 (100 ≤ TG<150 mg/dl, n=53) and H (150 ≤ TG mg/dl, n=53), respectively. RESULTS: Fasting total cholesterol, LDL-cholesterol, HDL-cholesterol, apoB-100 and lnRemL-C (remnant lipoprotein-cholesterol) levels were not correlated with max-IMT, but lnTG and lnapoB-48 were significantly correlated with max-IMT in all subjects. LnapoB-48 and apoB-48/TG ratio were significantly correlated with max-IMT in group N-2. By multiple regression analysis, age and lnapoB-48 were independent variables associated with max-IMT in group N-2. CONCLUSION: Serum apoB-48 level might be a good marker for the detection of early atherosclerosis in middle-aged subjects with normal-range levels of blood pressure and TG.

Comprehensive expressional analyses of antisense transcripts in colon cancer tissues using artificial antisense probes.

BACKGROUND: Recent studies have identified thousands of sense-antisense gene pairs across different genomes by computational mapping of cDNA sequences. These studies have shown that approximately 25% of all transcriptional units in the human and mouse genomes are involved in cis-sense-antisense pairs. However, the number of known sense-antisense pairs remains limited because currently available cDNA sequences represent only a fraction of the total number of transcripts comprising the transcriptome of each cell type. METHODS: To discover novel antisense transcripts encoded in the antisense strand of important genes, such as cancer-related genes, we conducted expression analyses of antisense transcripts using our custom microarray platform along with 2376 probes designed specifically to detect the potential antisense transcripts of 501 well-known genes suitable for cancer research. RESULTS: Using colon cancer tissue and normal tissue surrounding the cancer tissue obtained from 6 patients, we found that antisense transcripts without poly(A) tails are expressed from approximately 80% of these well-known genes. This observation is consistent with our previous finding that many antisense transcripts expressed in a cell are poly(A)-. We also identified 101 and 71 antisense probes displaying a high level of expression specifically in normal and cancer tissues respectively. CONCLUSION: Our microarray analysis identified novel antisense transcripts with expression profiles specific to cancer tissue, some of which might play a role in the regulatory networks underlying oncogenesis and thus are potential targets for further experimental validation. Our microarray data are available at http://www.brc.riken.go.jp/ncrna2007/viewer-Saito-01/index.html.

Genome-wide analysis of expression modes and DNA methylation status at sense-antisense transcript loci in mouse.

The functionality of sense-antisense transcripts (SATs), although widespread throughout the mammalian genome, is largely unknown. Here, we analyzed the SATs expression and its associated promoter DNA methylation status by surveying 12 tissues of mice to gain insights into the relationship between expression and DNA methylation of SATs. We have found that sense and antisense expression positively correlate in most tissues. However, in some SATs with tissue-specific expression, the expression level of a transcript from a CpG island-bearing promoter is low when the promoter DNA methylation is present. In these circumstances, the expression level of its opposite-strand transcript, especially when it is poly(A)-negative was coincidentally higher. These observations suggest that, albeit the general tendency of sense-antisense simultaneous expression, some antisense transcripts have coordinated expression with its counterpart sense gene promoter methylation. This cross-strand relationship is not a privilege of imprinted genes but seems to occur widely in SATs.

Molecular mechanisms of ezetimibe-induced attenuation of postprandial hypertriglyceridemia.

AIM: Postprandial hypertriglyceridemia (PHTG) has been shown repeatedly to be associated with metabolic syndrome and atherosclerotic cardiovascular diseases. We have recently reported that ezetimibe inhibits PHTG in patients with type IIb hyperlipidemia. Ezetimibe was also reported to atten-uate PHTG in combination with low-dose statins in patients with obesity or metabolic syndrome. We reported CD36-deficient (CD36KO) mice as a new model for PHTG, in which the synthesis of chylomicron (CM) in the small intestines is enhanced. In the current study, we investigated the effect of ezetimibe on PHTG in this mouse model of metabolic syndrome. METHODS: Wild-type (WT) mice fed a western diet, and CD36KO mice fed a normal chow diet, respectively, were treated for 3 weeks with and without ezetimibe, followed by an evaluation of triglyceride (TG) concentrations by enzymatic method and by high performance liquid chromatogra-phy (HPLC) as well as those of and apolipoprotein (Apo) B-48 in plasma and intestinal lymph after oral fat loading with olive oil. Intestinal mucosa was also harvested to evaluate the transcriptional regulation of the genes involved in the intestinal production of ApoB-containing lipoproteins. RESULTS: Ezetimibe dramatically reduced PHTG in both WT and CD36KO mice. HPLC analysis of plasma showed that the decrease in TG content in CM and CM remnants-sized particles contributed to this suppression, suggesting that CM production in the small intestines might be reduced after ezetimibe treatment. Intestinal lymph was collected after oral fat loading in ezetimibe-treated and non-treated mice. Both TG content and ApoB-48 mass were decreased in ezetimibe-treated mice. The quantitative RT-PCR of intestinal mucosa showed down-regulation of the mRNA expression of FATP4 and ApoB in both groups along with FABP2, DGAT1, DGAT2 and SCD1 in WT mice at postprandial state after ezetimibe treatment. CONCLUSION: Ezetimibe alone reduces PHTG by blocking both the absorption of cholesterol and the intracellular trafficking and metabolism of long-chain fatty acids in enterocytes, resulting in the reduction of the formation of ApoB-48 which is necessary for the ApoB48-containing lipoprotein production in the small intestines.

Fenofibrate reduces postprandial hypertriglyceridemia in CD36 knockout mice.

AIM: Metabolic syndrome (MetS) and postprandial hypertriglyceridemia (PHTG) are closely related and both are associated with coronary heart disease. We have demonstrated that CD36 deficiency is prevalent in the genetic background of MetS and is accompanied by PHTG concomitantly with an increase in remnants and a decrease in high density lipoprotein cholesterol. These findings make CD36 knockout mice (CD36KO) an interesting model for evaluating PHTG in MetS. Fenofibrate was reported to reduce fasting and postprandial triglyceride (TG) levels in hypertriglyceridemic subjects with MetS. To define its mechanism, we investigated the effect of fenofibrate on PHTG in CD36KO. METHODS: Wild-type (WT) and CD36KO mice were fed chow diet and fenofibrate for two weeks. TG concentrations and lipoprotein profiles were assessed during fasting and in the postprandial state in plasma; intestinal mucosa and lymph were collected after oral fat loading for both treatment groups. RESULTS: Fenofibrate treatment markedly suppressed the postprandial TG response in CD36KO along with decreased apoB-48 levels in plasma. HPLC analysis depicted the decrease of TG content in chylomicrons (CM) and CM remnant-sized lipoproteins contributed to this suppression, suggesting that CM and CM remnant production in the intestines might be attenuated by fenofibrate. ApoB-48 and TG levels in intestinal lymph were markedly reduced after treatment. Intestinal mRNA expression of apoB was also reduced in the postprandial state after fenofibrate administration without affecting any other genes related to CM assembly and production. CONCLUSION: Fenofibrate reduces PHTG in CD36KO partially through attenuating intestinal CM production.

H-InvDB in 2009: extended database and data mining resources for human genes and transcripts.

We report the extended database and data mining resources newly released in the H-Invitational Database (H-InvDB; http://www.h-invitational.jp/). H-InvDB is a comprehensive annotation resource of human genes and transcripts, and consists of two main views and six sub-databases. The latest release of H-InvDB (release 6.2) provides the annotation for 219,765 human transcripts in 43,159 human gene clusters based on human full-length cDNAs and mRNAs. H-InvDB now provides several new annotation features, such as mapping of microarray probes, new gene models, relation to known ncRNAs and information from the Glycogene database. H-InvDB also provides useful data mining resources-'Navigation search', 'H-InvDB Enrichment Analysis Tool (HEAT)' and web service APIs. 'Navigation search' is an extended search system that enables complicated searches by combining 16 different search options. HEAT is a data mining tool for automatically identifying features specific to a given human gene set. HEAT searches for H-InvDB annotations that are significantly enriched in a user-defined gene set, as compared with the entire H-InvDB representative transcripts. H-InvDB now has web service APIs of SOAP and REST to allow the use of H-InvDB data in programs, providing the users extended data accessibility.

Pulmonary hypertension associated with bone marrow transplantation.

Bone marrow transplantation (BMT) is one of the promising methods of treatment of hematologic malignancy. However, it has a variety of complications since it involves fatal doses of anti-cancer drugs and radiation during the conditioning period. Among the various complications of BMT, pulmonary hypertension is rare and its pathogenesis is poorly understood. A 35-year-old female with acute myeloid leukemia (AML) presented with pulmonary hypertension after BMT. Although she exhibited severe dyspnea on admission, her general condition markedly improved after oxygen therapy and treatment with warfarin and beraprost sodium. Her pulmonary hypertension was diagnosed as pulmonary arterial hypertension (PAH) related to BMT. Although PAH has only rarely been reported as a complication of BMT, we present here for the first time an adult patient with PAH associated with BMT who exhibited marked improvement with medical treatment. This case indicates that attention needs to be paid to the clinical symptoms and physical findings of PAH as a complication of BMT.

Differential reactivities of four homogeneous assays for LDL-cholesterol in serum to intermediate-density lipoproteins and small dense LDL: comparisons with the Friedewald equation.

BACKGROUND: In routine clinical laboratory testing and numerous epidemiological studies, LDL-cholesterol (LDL-C) has been estimated commonly using the Friedewald equation. We investigated the relationship between the Friedewald equation and 4 homogeneous assays for LDL-C. METHODS: LDL-C was determined by 4 homogeneous assays [liquid selective detergent method: LDL-C (L), selective solubilization method: LDL-C (S), elimination method: LDL-C (E), and enzyme selective protecting method: LDL-C (P)]. Samples with discrepancies between the Friedewald equation and the 4 homogeneous assays for LDL-C were subjected to polyacrylamide gel electrophoresis and the beta-quantification method. RESULTS: The correlations between the Friedewald equation and the 4 homogeneous LDL-C assays were as follows: LDL-C (L) (r=0.962), LDL-C (S) (r=0.986), LDL-C (E) (r=0.946) and LDL-C (P) (r=0.963). Discrepancies were observed in sera from type III hyperlipoproteinemia patients and in sera containing large amounts of midband and small dense LDL on polyacrylamide gel electrophoresis. LDL-C (S) was most strongly correlated with the beta-quantification method even in sera from patients with type III hyperlipoproteinemia. CONCLUSIONS: Of the 4 homogeneous assays for LDL-C, LDL-C (S) exhibited the closest correlation with the Friedewald equation and the beta-quantification method, thus reflecting the current clinical databases for coronary heart disease.