Dietary melatonin and liver cancer incidence in Japan: From the Takayama study.

There is some biological plausibility that exogenous melatonin plays a role in preventing liver carcinogenesis. There has been little research on the association between melatonin intake in a normal diet and health outcomes. We evaluated the association between dietary melatonin intake and the incidence of liver cancer in a population-based prospective study in Japan. This study included 30,824 residents of Takayama city who were 35 years of age or older in 1992 and had participated in the Takayama study, Japan. Dietary intake was assessed using a validated food frequency questionnaire at the baseline. Melatonin content in foods was measured by liquid chromatography-tandem mass spectrometry. Cancer incidence was confirmed through regional population-based cancer registries in Gifu. Liver cancer was defined as code C22 according to the International Classification of Diseases and Related Health Problems, 10th Revision. Hazard ratios for liver cancer were estimated for the tertile groups of melatonin intake using a Cox proportional hazards model. During the mean follow-up period of 13.6 years, 189 individuals developed liver cancer. Compared with subjects in the lowest tertile of melatonin intake, those in the middle and highest tertiles had decreased risks of liver cancer, with a significant linear trend after multivariate adjustments (hazard ratios: 0.64 and 0.65, respectively, trend p = 0.023). There was no significant interaction by sex (interaction p = 0.54). This initial finding, which needs to be confirmed by further studies, suggests that consuming melatonin-containing foods might play a role in the prevention of liver cancer.

Dietary advanced glycation end products and cancer risk in Japan: From the Takayama study.

Few large epidemiological studies have evaluated the association between dietary advanced glycation end products (AGEs) and cancer risk. We evaluated the relationship between dietary AGE intake and the incidence of total cancer and site-specific cancers in a population-based prospective study in Japan. Participants were 14,173 men and 16,549 women who were 35 years of age or older in 1992. Dietary intake was assessed via a validated food frequency questionnaire. Intake of the AGE Nε -carboxymethyl-lysine (CML) was estimated using databases of CML content in foods determined using ultraperformance liquid chromatography-tandem mass spectrometry. Cancer incidence was confirmed through regional population-based cancer registries. During a mean follow-up period of 13.3 years, 1954 men and 1477 women developed cancer. We did not observe a significant association between CML intake and the risk of total cancer in men or women. In men, compared with the lowest quartile of CML intake, the hazard ratios of liver cancer for the second, third, and highest quartiles were 1.69 (95% CI: 0.92-3.10), 1.48 (95% CI: 0.77-2.84), and 2.10 (95% CI: 1.10-3.98; trend p = 0.04). Conversely, a decreased relative risk of male stomach cancer was observed for the second and highest quartiles of CML intake versus the lowest quartile, with hazard ratios of 0.73 and 0.67, respectively (trend p = 0.08). Our finding on the potential harmfulness of consuming AGEs on liver cancer risk is intriguing and warrants further study.

Inhibitory effects of pentoxifylline on inflammation-related tumorigenesis in rat colon.

Chronic inflammation in the colorectum increases the risk of colorectal cancer development. Pentoxifylline, a medicine used for improving the circulation, has been reported to inhibit TNF-α production and to ameliorate inflammatory bowel disease and non-alcoholic steatohepatitis. In this study, we investigated the effects of pentoxifylline on inflammation-related colon tumorigenesis in a rodent model using Kyoto APC delta rats, which have APC mutation and are susceptible to colon carcinogenesis. Male Kyoto APC delta rats were treated with azoxymethane and dextran sodium sulfate, and were subsequently administered water, with or without pentoxifylline. At the end of the experiment, the development of colorectal tumor was significantly inhibited in the pentoxifylline group. The pentoxifylline treatment also lowered the levels of oxidative stress markers and mRNAs of pro-inflammatory cytokines, including TNF-α and IL-6, in the colon mucosa. The PCNA labeling index and the inflammation score were also decreased in the colon of rats in the pentoxifylline -treated group. We also used an endoscopy to observe the tumor progression and inflammation in the colon of rats, revealing that inflammation grade was significantly lower in pentoxifylline-treated group at several points during the experiment. These findings suggest that pentoxifylline treatment might be useful for chemoprevention of inflammation-related colon cancer.

Inorganic phosphorus (Pi) in CSF is a biomarker for SLC20A2-associated idiopathic basal ganglia calcification (IBGC1).

INTRODUCTION: Idiopathic basal ganglia calcification (IBGC), also called Fahr's disease or recently primary familial brain calcification (PFBC), is characterized by abnormal deposits of minerals including calcium mainly and phosphate in the brain. Mutations in SLC20A2 (IBGC1 (merged with former IBGC2 and IBGC3)), which encodes PiT-2, a phosphate transporter, is the major cause of IBGC. Recently, Slc20a2-KO mice have been showed to have elevated levels of inorganic phosphorus (Pi) in cerebrospinal fluid (CSF); however, CSF Pi levels in patients with IBGC have not been fully examined. METHODS: We investigated the cases of 29 patients with IBGC including six patients with SLC20A2 mutation and three patients with PDGFB mutation, and 13 controls. The levels of sodium (Na), potassium (K), chloride (Cl), calcium (Ca), and Pi in sera and CSF were determined by potentiometry and colorimetry. Moreover, clinical manifestations were investigated in the IBGC patients with high Pi levels in CSF. RESULTS: The study revealed that the average level of Pi in the CSF of the total group of patients with IBGC is significantly higher than that of the control group, and the levels of Pi in CSF of the IBGC patients with SLC20A2 mutations are significantly higher than those of the IBGC patients with PDGFB mutations, the other IBGC patients and controls. CONCLUSION: Results of this study suggest that the levels of CSF Pi will be a good biomarker for IBGC1.

Prediction of Early BK Virus Infection in Kidney Transplant Recipients by the Number of Cells With Intranuclear Inclusion Bodies (Decoy Cells).

BACKGROUND: BK virus (BKV) is the cause of nephropathy. Because BKV nephropathy can progress to graft loss, early diagnosis of BKV infection is very important. In this study, we aimed to investigate the utility of quantifying cells with intranuclear inclusion bodies (decoy cells) in urinary sediment for the screening and monitoring of BKV infection in renal transplant recipients at our hospital. METHODS: This was a retrospective single-center study. Urine sediment examination was performed at each outpatient visit, and the number of decoy cells was measured in the whole microscopic field. Patients (n = 41) were divided into the BK viremia group (blood positive for BKV DNA by polymerase chain reaction [PCR]) and non-BK viremia group (blood negative for BKV DNA by PCR), and the decoy cell count in urinary sediments was examined. RESULTS: The maximum decoy cell count was significantly higher (P = 0.04) in the BK viremia group than in the non-BK viremia group. In the receiver operating characteristic curve for the maximum decoy cells, the cutoff value was 507 cells. The area under the receiver operating characteristic curve was 0.8774 (95% confidence interval, 0.7739-0.9810). The number of decoy cells at the time of appearance in the BK viremia group was not significantly different from that in the non-BK viremia group. However, the BK viremia group showed an increasing trend, whereas the non-BK viremia group showed a decreasing trend, in the number of decoy cells. There was a positive correlation between the number of decoy cells and the data from the urine BKV-DNA PCR quantification (correlation coefficient [r] = 0.74). CONCLUSIONS: Measurement of decoy cells in urinary sediments may predict early BKV infection, and if performed quickly, it may be useful for screening and continuous monitoring of BKV infection in renal transplant recipients.

Activation of NLRP3 signalling accelerates skin wound healing.

The process of skin wound healing involves the following three steps: inflammation, tissue formation and tissue remodelling. These optimal steps are required for the development of normal wound healing. Recent reports demonstrated that inflammasomes are involved in the innate immune response. In the present study, we examined whether the activation of inflammasomes affects the process of skin wound repair. The skin wound repair model was established using wild-type (WT), NACHT, LRR and PYD domains-containing protein 3 (NALP3) knockout (KO) and ASC-KO mice. The wounds were observed every other day, and changes in wound size over time were calculated using photography. Wound repair in NALP3-KO and ASC-KO mice was significantly impaired compared with WT mice. Isoliquiritigenin, an inhibitor of NALP3, decreased the rate of wound repair in WT mice. mRNA expression of pro-inflammatory cytokines in the wound sites of NALP3-KO mice was markedly decreased compared with WT mice. Treatment with adenosine triphosphate (ATP), a ligand of NALP3, upregulated the mRNA expression of pro-inflammatory cytokines at the wound site and accelerated wound healing in the WT mice. Scratch assay revealed that ATP accelerated wound closure in mouse embryonic fibroblasts from WT mice but not from NALP3-KO mice. In conclusion, the present study demonstrated that NALP3 pathway activation is involved in wound repair, and the topical use of ATP may be useful as an effective treatment for accelerating wound healing.

Preventive effects of the sodium glucose cotransporter 2 inhibitor tofogliflozin on diethylnitrosamine-induced liver tumorigenesis in obese and diabetic mice.

Sodium glucose cotransporter 2 inhibitors are expected to ameliorate the abnormalities associated with metabolic syndrome including non-alcoholic fatty liver disease. In this study, we investigated the effects of the sodium glucose cotransporter 2 inhibitor tofogliflozin on the development of non-alcoholic fatty liver disease-related liver tumorigenesis in C57BL/KsJ-+Lepr db /+Lepr db obese and diabetic mice. The direct effects of tofogliflozin on human liver cancer cell proliferation were also evaluated. Mice were administered diethylnitrosamine-containing water for 2 weeks and were treated with tofogliflozin throughout the experiment. In mice treated with tofogliflozin, the development of hepatic preneoplastic lesions was markedly suppressed, and hepatic steatosis and inflammation significantly reduced, as evaluated using the non-alcoholic fatty liver disease activity score, in comparison with the control mice. Serum levels of glucose and free fatty acid and mRNA expression levels of pro-inflammatory markers in the liver were reduced by tofogliflozin treatment. Conversely, the proliferation of sodium glucose cotransporter 2 protein-expressing liver cancer cells was not inhibited by this agent. These findings suggest that tofogliflozin suppressed the early phase of obesity- and non-alcoholic fatty liver disease-related hepatocarcinogenesis by attenuating chronic inflammation and hepatic steatosis. Therefore, sodium glucose cotransporter 2 inhibitors may have a chemopreventive effect on obesity-related hepatocellular carcinoma.

The inhibition of NLRP3 signaling attenuates liver injury in an α-galactosylceramide-induced hepatitis model.

Inflammasomes are involved in innate immune responses. Several NOD-Like receptors (NLRs) participate in the formation of inflammasomes. NACHT, LRR and PYD domains-containing protein 3 (NALP3) belongs to the NLR family and recognizes adenosine triphosphate (ATP), crystals, and Reactive Oxygen Species (ROS). This study examined the effect of inflammasomes on alpha-galactosylceramide (GalCer)-induced liver injury using NALP3-knockout (KO) mice. GalCer administration induced inflammasome activation and IL-1ß-maturation. In NALP3-KO mice treated with GalCer, serum ALT levels were significantly reduced compared with those in GalCer-treated WT mice. Histological examination revealed decreased necrosis in NALP3-KO mice compared with WT mice, consistent with ALT levels. Expression of proinflammatory cytokines (such as IL-6, and TNF-α) and chemokines was also significantly suppressed in NALP3-KO mice. Moreover, flow cytometry analysis revealed fewer infiltrating immune cells in the livers of GalCer-treated NALP3-KO mice. Inportantly, the frequency of MDSCs (CD11b+Gr-1int cells), which suppress the immune response, was significantly increased in GalCer-treated NALP3-KO mice. In conclusion, NALP3 inhibition attenuated liver injury in GalCer-induced hepatitis. The inhibition of NALP3 signaling coused be a therapeutic target in immune-mediated liver injury.

Deficiency of NALP3 Signaling Impairs Liver Regeneration After Partial Hepatectomy.

Inflammatory response is required to proceed the optimal liver regeneration after liver injury. Recent reports demonstrated that inflammasomes are involved in the innate immune response. Several NOD-Like receptors (NLRs) participated in the formation of the inflammasomes. NACHT, LRR, and PYD domain-containing protein 3 (NALP3) belongs to the NLR families and recognizes adenosine triphosphate (ATP), crystals, and reactive oxygen species. The present study examined the effect of inflammasomes on the process of liver regeneration using NALP3 knockout (KO) mice. The activation of inflammasomes in the liver was induced after 70% partial hepatectomy (PHx). The liver-to-body weight ratio was significantly decreased in NALP3-KO mice compared to that in WT mice after PHx. The number of Ki67-positive cells and the expression of Cyclin D1 and E1 after PHx were reduced in NALP3-KO mice compared to WT mice. The expression of pro-inflammatory cytokines (IL-1ß, TNF-α, and IL-6) were decreased in the remnant liver of NALP3-KO mice compared to WT mice. Flow cytometric analysis revealed that the expression of chemokines was decreased and the accumulation of CD11b-positive cells was suppressed in NALP3-KO mice after PHx. The treatment with ATP, which is a ligand to NALP3, increased the liver-to-body weight ratio in WT mice. These results indicate that NALP3 signaling is required for the induction of inflammatory response and the development of liver regeneration after PHx.

The Inhibition of Indoleamine 2,3-Dioxygenase Accelerates Early Liver Regeneration in Mice After Partial Hepatectomy.

BACKGROUND AND AIM: The inflammatory response accelerates early liver regeneration after liver injury and resection. Recent studies have demonstrated that indoleamine 2,3-dioxygenase-1 (IDO1) suppresses the activation of inflammatory cells and induces immune tolerance. In this study, we examined the role of IDO1 in liver regeneration after partial hepatectomy (PHx). METHODS: WT or IDO1-knockout (IDO1-KO) mice received 70% PHx. The liver-body weight ratio after PHx was measured and hepatocyte growth was assessed by immunostaining. The expression of cell cycle genes and pro-inflammatory cytokines in the liver was analyzed by quantitative RT-PCR. In addition, 1-methyl-DL-tryptophan (1-MT), which is an IDO1 inhibitory agent, was given to WT mice and the liver-body weight ratio was measured after PHx. RESULTS: The liver-body weight ratio was significantly increased in IDO1-KO mice compared with that in WT mice after PHx. More Ki-67-positive cells were present in IDO1-KO mice than in WT mice after PHx. The expression of cell cycle genes (cyclin D1, cyclin E) and pro-inflammatory cytokines (IL-1ß, TNF-α and IL-6) was up-regulated in the remnant liver of IDO1-KO mice compared with WT mice. Moreover, treatment with 1-MT promoted liver regeneration. CONCLUSION: IDO1 deficiency promoted early liver regeneration after PHx, indicating that IDO1 suppresses the production of inflammatory cytokines and subsequently inhibits hepatocyte proliferation during liver regeneration.

Quantitative Sonographic Assessment of the Quadriceps Femoris Muscle in Healthy Japanese Adults.

OBJECTIVES: The aim of this study was to evaluate the relationships among aging, muscle strength, and image feature analysis of the quadriceps femoris muscle and to evaluate the relationship between aging, muscle strength, and sonographic findings. METHODS: One hundred forty-five healthy volunteers participated in the study. The participants were classified into 6 groups on the basis of sex and age. To assess muscle quality, texture analysis was defined with the following parameters: mean, skewness, kurtosis, inverse difference moment, sum of entropy, and angular second moment. The knee extension force in the sitting position and thickness of the quadriceps femoris muscle were also measured. RESULTS: The quadriceps femoris thickness, skewness, kurtosis, inverse difference moment, angular second moment, and muscle strength were significantly decreased in elderly participants versus those in the younger and middle-aged groups (P < .05). In contrast, the mean and sum of entropy were significantly decreased in the younger group compared with the middle-aged and elderly groups. CONCLUSIONS: Sonography has the capacity to quantitatively assess muscular morphologic changes due to aging and could be a valuable tool for early detection of musculoskeletal disorders.

Behavior of leucine-rich repeat-containing G-protein coupled receptor 5-expressing cells in the reprogramming process.

It remains unclear what cells are proper for the generation of induced pluripotent stem cells (iPSCs). Leucine-rich repeat-containing G-protein coupled receptor 5 (Lgr5) is well known as a tissue stem cell and progenitor marker, both of which are reported to be sensitive to reprogramming. In the present study, we examined the reprogramming behavior of Lgr5-expressing cells (Lgr5+ cells). First, we compared reprogramming behavior using mouse Lgr5+ and Lgr5 negative (Lgr5-) hair follicles (HFs). The number of alkaline phosphatase staining-positive cells was lesser in a well of Lgr5+ HFs than in Lgr5- HFs; however, the ratio of Nanog+ SSEA1+ cells in the cell mixture derived from Lgr5+ HFs was much higher than that from Lgr5- HFs. Lgr5+ cells could be induced from mouse embryonic fibroblasts (MEFs) after transduction with Yamanaka factors. As shown in HFs, the progeny of Lgr5+ cells arising from MEFs highly converted into Nanog+ cells and did not form Nanog- colonies. The progeny represented the status of the late reprogramming phase to a higher degree than the nonprogeny. We also confirmed this using human Lg5+ cells. Our findings suggest that the use of Lgr5+ cells will minimize sorting efforts for obtaining superior iPSCs.

Late Reactivation of Hepatitis B Virus after Chemotherapies for Hematological Malignancies: A Case Report and Review of the Literature.

Reactivation of hepatitis B virus (HBV) is a serious complication of immunosuppressive therapy and cytotoxic chemotherapy. The optimal duration of HBV-DNA monitoring for at-risk patients depends on the clinical features of reactivation, especially the range of potency from therapies to reactivation. We present a case of very late reactivation after chemotherapy for lymphoma and review previous reports of late reactivation cases. We also underscore the significance of developing an indicator for anti-HBV immunity which can be used to determine the optimal monitoring period.

Serum concentrations of l-kynurenine predict clinical outcomes of patients with peripheral T-cell lymphoma, not otherwise specified.

Indoleamine 2,3-dioxygenase exerts intense immunomodulatory effects due to enzymatic activities that catalyze the breakdown of the essential amino acid l-tryptophan. The activity of indoleamine 2,3-dioxygenase can be estimated by measuring serum l-kynurenine concentrations. Here, we aimed to determine the role of l-kynurenine as a prognostic factor for peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) in a retrospective analysis of data derived from 31 consecutive patients between June 2000 and March 2013 who were histologically diagnosed with PTCL-NOS according to the World Health Organization classification and treated with 6-8 cycles of cyclophosphamide, doxorubicin or pirarubicin, vincristine, and prednisolone. l-kynurenine concentrations in serum samples collected at admission were measured using high-performance liquid chromatography. The median serum concentration of l-kynurenine was 3.28 (range 0.92-8.16) µM. The l-kynurenine cutoff was set at 3.07 µM using receiver operating characteristics curves. The complete remission rates of patients with l-kynurenine <3.07 and ≥3.07 µM were 69% and 51%, respectively. The 5-year overall survival (OS) rates for patients with l-kynurenine <3.07 and ≥3.07 µM were 80.2% and 23.4%, respectively (p < 0.001). More advanced age, poor performance status, elevated lactate dehydrogenase, an unfavorable International Prognostic Index, and a poor prognostic index for T-cell lymphoma were significantly worse factors for OS. Multivariate analyses revealed only l-kynurenine as an independent prognostic factor for OS. In conclusion, serum concentrations of l-kynurenine might comprise a novel prognostic factor with which to determine the outcomes of treatment for PTCL-NOS. Copyright © 2016 John Wiley & Sons, Ltd.

Role of invariant NKT cells in lipopolysaccharide-induced lethal shock during encephalomyocarditis virus infection.

Viral infections can give rise to secondary bacterial infections. In the present study, we examined the role of invariant natural killer T (iNKT) cells in lipopolysaccharide (LPS)-induced lethal shock during encephalomyocarditis virus (EMCV) infection. Wild-type (WT) mice and Jα18 gene knockout (Jα18 KO) mice were inoculated with EMCV, 5days prior to challenging with LPS. The survival rate of Jα18 KO mice subjected to EMCV and LPS was significantly higher than that of WT mice. TNF-α and nitric oxide (NO) production were increased in WT mice, than that in Jα18 KO mice, after the administration of EMCV and LPS. EMCV infection increased the number of iNKT cells and IFN-γ production by iNKT cells in WT mice. Moreover, EMCV infection enhanced the expression of Toll-like receptor 4 (TLR4) in the lung and spleen. IFN-γ also increased the expression of TLR4 in splenocytes. These findings indicated that EMCV infection activated iNKT cells, and IFN-γ secreted from the iNKT cells up-regulated the expression of TLR4 in various tissues. As a result, EMCV-infected mice were susceptible to LPS and easily developed the lethal shock. In conclusion, iNKT cells were involved in the development of LPS-induced lethal shock during EMCV infection.

Symptomatic Acute Pancreatitis Induced by Nilotinib: A Report of Two Cases.

Nilotinib is a selective tyrosine kinase inhibitor for the treatment of Philadelphia chromosome-positive leukemias. An elevation of the pancreatic enzyme level is one of the major adverse events associated with nilotinib, but whether or not nilotinib induces symptomatic pancreatitis remains to be elucidated. The cases of two chronic myeloid leukemia patients treated with nilotinib who developed symptomatic acute pancreatitis on the third and fifth day of nilotinib administration are herein presented. Since both patients had no other etiologies for pancreatitis, nilotinib was considered to be the causal agent. The withdrawal of nilotinib resulted in a prompt recovery. These cases underline the importance of recognizing pancreatitis as a possible adverse event associated with nilotinib.

Catechins and Its Role in Chronic Diseases.

The mechanisms of action of polyphenols have attracted much attention. Catechins are generally known as tea polyphenols. Researchers have extensively investigated the molecular mechanisms of these substances, especially (-)-epigallocatechin gallate of green tea catechin, and have provided new insights in the prevention and therapy for chronic diseases. This chapter summarizes catechins and their effects on chronic diseases, including metabolic syndromes, cardiovascular diseases, neurodegenerative diseases, and cancer, focusing on the effects of green tea catechins.

The Deficiency of Indoleamine 2,3-Dioxygenase Aggravates the CCl4-Induced Liver Fibrosis in Mice.

In the present study, we examined the role of indoleamine 2,3-dioxygenase (IDO) in the development of CCl4-induced hepatic fibrosis. The liver fibrosis induced by repetitive administration with CCl4 was aggravated in IDO-KO mice compared to WT mice. In IDO-KO mice treated with CCl4, the number of several inflammatory cells and the expression of pro-inflammatory cytokines increased in the liver. In the results, activated hepatic stellate cells (HSCs) and fibrogenic factors on HSCs increased after repetitive CCl4 administration in IDO-KO mice compared to WT mice. Moreover, the treatment with l-tryptophan aggravated the CCl4-induced hepatic fibrosis in WT mice. Our findings demonstrated that the IDO deficiency enhanced the inflammation in the liver and aggravated liver fibrosis in repetitive CCl4-treated mice.

[Physiological Function of Apolipoproteins and Atherosclerosis].

We have studied the physiological function of four apolipoproteins. First, apo A-I is a major component of HDL and plays a crucial role in reverse cholesterol transport. The lipid-poor apo A-I concentration in plasma was significantly increased in patients with coronary artery disease compared with healthy controls, which may be caused by the impairment of the reverse cholesterol transport pathway. Second, the plasma A-IV concentration was significantly elevated in uremic patients, and we revealed the mechanism of apo A-IV accumulation in plasma using a rat model. Third, apo B48 is associated with lipid absorption in the intestinal epithelium, but the lymph apo B48 output was not changed during the absorption of mid-chain triglycerides, unlike apo A-IV. Fourth, we showed for the first time that the cerebrospinal apo E level was reduced in early-onset Alzheimer's disease and increased in a late-onset group. Taken together, apolipoproteins show various functions via the regulation of lipid metabolism. We have also studied the effect of cytokines on atherosclerosis using cytokine knockout mice. TNF-α and IL-1ß increased the number and size of atherosclerotic lesions, but IFN-γ attenuated the lesions. Plaque formation is influenced by not only the cholesterol level in plasma but also cytokine levels and other unknown factors. It may be of no merit to give cholesterol-lowering drugs to hypercholesterolemic patients without plaque. It is, thus, strongly expected that a biomarker which can predict the presence of plaque will be developed in the future.

[Introduction].

It is well-known that plasma HDL-C shows a negative correlation with the incidence of coronary artery disease, which was confirmed by the Framingham Study, a famous prospective cohort study, in 1977. At first, HDL-C was determined by the precipitation method, and then the homogeneous method of HDL-C determination was developed in the 1990's in Japan. This method enabled HDL-C measurement in a short time for many samples. HDL removes free cholesterol from somatic cells by accepting cell cholesterol via ATP-binding cassette transporter A1. Cholesterol ester in HDL is transferred to VLDL and LDL by the action of cholesterol ester transfer protein or is incorporated into the liver via SR-BI. This pathway is called reverse cholesterol transport, which can regress atheromatous plaques. On the other hand, some CETP inhibitors, which can increase the HDL-C level have been developed in the world. However, the development of all candidate drugs was stopped because of side or insufficient effects. In addition, patients with CETP deficiency, whose HDL-C levels are markedly high, sometimes show the findings of coronary artery disease. These observations indicate that elevating HDL-C levels alone may not lower the cardiovascular disease risk. Recently, it was reported that HDL has pleiotropic functions other than reverse cholesterol transport. Actually, HDL inhibits lipid oxidation, impairs leukocyte adhesion and monocyte activation, promotes nitric oxide production, and inhibits the activation of platelets and the coagulation cascade. Functional characterization of HDL is, therefore, necessary for precise assessment of the cardiovascular risk and effectiveness of risk reduction.