EP4 receptor-associated protein regulates gluconeogenesis in the liver and is associated with hyperglycemia in diabetic mice.

Prostaglandin E2 receptor 4-associated protein (EPRAP) is a key molecule in suppressing inflammatory responses in macrophages. EPRAP is expressed not only in macrophages but also in hepatocytes; however, the role of EPRAP in hepatocytes has not yet been defined. To examine the physiological role of hepatic EPRAP in mice, we performed the glucose tolerance test and the hyperinsulinemic-euglycemic clamp in high-fat sucrose diet (HFSD)-fed wild-type (WT) and Eprap null mice. We evaluated the contribution of EPRAP to gluconeogenesis by pyruvate tolerance test and primary hepatocyte experiments. Furthermore, lentivirus-expressing Eprap-specific small-hairpin RNA was injected in db/ db mice. HFSD-fed Eprap null mice had significantly lower blood glucose levels than HFSD-fed WT mice. Eprap null mice also had low glucose levels after fasting or pyruvic acid injection. Moreover, primary hepatocytes from Eprap-deficient mice showed decreased glucose production and lower expression of the Phosphoenol pyruvate carboxykinase and Glucose 6-phosphatase genes. Lentivirus-mediated hepatic Eprap suppression decreased glucose levels and the expression of gluconeogenic genes in db/ db mice. We conclude that EPRAP regulates gluconeogenesis in hepatocytes and is associated with hyperglycemia in diabetic mice. Our data suggest that suppression of EPRAP could be a novel strategy for the treatment of diabetes.

Imaging mass spectroscopy delineates the thinned and thickened walls of intracranial aneurysms.

OBJECT: The wall thickness of intracranial aneurysms (IAs) is heterogeneous. Although thinning of the IA wall is thought to contribute to IA rupture, the underlying mechanism remains poorly understood. Recently, imaging mass spectroscopy (IMS) has been used to reveal the distribution of phospholipids in vascular diseases. To investigate the feature of phospholipid composition of IA walls, we conducted IMS in a rat model of experimentally induced IA. MATERIAL AND METHODS: IAs were surgically induced in 7-week-old male rats and analyzed by IMS in negative-ion mode. RESULTS: A molecule at m/z 885.5 was more abundant in the thickened wall than in the thinned wall (P = 0.03). Multiple-stage mass spectroscopy revealed the molecule to be phosphatidylinositol containing stearic acid and arachidonic acid (PI 18:0/20:4). Immunohistochemistry indicated that vascular smooth muscle cells (SMCs) in the thickened wall had dedifferentiated phenotypes. To investigate the relationship between accumulation of PI (18:0/20:4) and phenotypic changes in SMCs, we subjected primary mouse aortic SMCs to liquid chromatography-tandem mass spectrometry. Notably, dedifferentiated SMCs had 1.3-fold more PI (18:0/20:4) than partly differentiated SMCs. CONCLUSIONS: Our study demonstrated the heterogeneity in phospholipid composition of the aneurysmal walls using experimentally induced IAs. PI (18:0/20:4) accumulated at high levels in the thickened aneurysmal wall where synthetic dedifferentiated SMCs exist, suggesting that this phospholipid may be involved in the phenotypic switching of medial SMCs in the IA wall.

Deficiency in EP4 Receptor-Associated Protein Ameliorates Abnormal Anxiety-Like Behavior and Brain Inflammation in a Mouse Model of Alzheimer Disease.

Microglia are thought to play key roles in the progression of Alzheimer disease (AD). Overactivated microglia produce proinflammatory cytokines, such as tumor necrosis factor-α, which appear to contribute to disease progression. Previously, we reported that prostaglandin E2 type 4 receptor-associated protein (EPRAP) promotes microglial activation. We crossed human amyloid precursor protein transgenic mice from strain J20+/- onto an EPRAP-deficient background to determine the role of EPRAP in AD. Behavioral tests were performed in 5-month-old male J20+/-EPRAP+/+ and J20+/-EPRAP-/- mice. EPRAP deficiency reversed the reduced anxiety of J20+/- mice but did not affect hyperactivity. No differences in spatial memory were observed between J20+/-EPRAP+/+ and J20+/-EPRAP-/- mice. In comparison with J20+/-EPRAP+/+, J20+/-EPRAP-/- mice exhibited less microglial accumulation and reductions in the Cd68 and tumor necrosis factor-α mRNAs in the prefrontal cortex and hippocampus. No significant differences were found between the two types of mice in the amount of amyloid-ß 40 or 42 in the cortex and hippocampus. J20+/-EPRAP-/- mice reversed the reduced anxiety-like behavior and had reduced microglial activation compared with J20+/-EPRAP+/+ mice. Further research is required to identify the role of EPRAP in AD, but our results indicate that EPRAP may be related to behavioral and psychological symptoms of dementia and inflammation in patients with AD.

EP4 Receptor-Associated Protein in Macrophages Protects against Bleomycin-Induced Pulmonary Inflammation in Mice.

Excessive activation of inflammatory macrophages drives the pathogenesis of many chronic diseases. EP4 receptor-associated protein (EPRAP) has been identified as a novel, anti-inflammatory molecule in macrophages. In this study, we investigated the role of EPRAP using a murine model of bleomycin (BLM)-induced pulmonary inflammation. When compared with wild-type mice, EPRAP-deficient mice exhibited significantly higher mortality, and increased accumulation of macrophages and proinflammatory molecules in the lung 7 d post-BLM administration. Accordingly, the levels of phosphorylated p105, MEK1/2, and ERK1/2 were elevated in EPRAP-deficient alveolar macrophages following BLM administration. In contrast, macrophage-specific EPRAP overexpression decreased the production of proinflammatory cytokines and chemokines, suggesting that EPRAP in macrophages plays a key role in attenuating BLM-induced pulmonary inflammation. As EPRAP is phosphorylated after translation, we examined the role of posttranslational modifications in cellular inflammatory activation using mouse embryo fibroblasts (MEFs) expressing mutant EPRAP proteins. Expression of mutant EPRAP, in which serine-108 and serine-608 were replaced with alanine (EPRAP S108A/S608A), markedly suppressed TNF-α production in LPS-treated MEFs. Conversely, the serine phosphatase 2A (PP2A) inhibitor, cantharidic acid, increased LPS-induced TNF-α production in MEFs expressing wild-type EPRAP, but not in MEFs expressing EPRAP S108A/S608A. Immunoprecipitation analyses demonstrated that EPRAP associated with PP2A in both MEFs and alveolar macrophages from BLM-treated mice. Our data suggest that PP2A dephosphorylates EPRAP, which may be a crucial step in exertion of its anti-inflammatory properties. For these reasons, we believe the EPRAP-PP2A axis in macrophages holds the key to treating chronic inflammatory disorders.

A therapeutic angiogenesis of sustained release of basic fibroblast growth factor using biodegradable gelatin hydrogel sheets in a canine chronic myocardial infarction model.

This study investigated the safety and efficacy of a sustained release of basic fibroblast growth factor (bFGF) with biodegradable gelatin hydrogel sheets as therapeutic angiogenesis in canine chronic myocardial infarction (MI) models. Canine chronic MI model was induced by ligating the left anterior descending coronary artery and its diagonal branches. At 4 week post-induction, we applied either saline (Control group, n = 5) or 200 µg of bFGF (Treatment group, n = 6) soaked gelatin hydrogel sheets on the ischemic area of the left ventricular (LV) wall. At 6 weeks after the procedure, we evaluated the efficacy by echocardiography and immunohistochemical study. There were no procedure-related adverse events or deaths. The serum bFGF level was under detectable levels in all animals at any sampling points. In terms of efficacy, echocardiographic evaluation demonstrated that fractional shortening was significantly improved in the treatment group. In addition, immunohistochemical study showed that the capillary density in the border zone of the MI area, as well as the MI area, significantly increased in the treatment group. Therapeutic angiogenesis by bFGF using biodegradable gelatin hydrogel sheets was safe, increased the capillary density, and improved LV function in canine chronic MI models.

EP4 Receptor-Associated Protein in Macrophages Ameliorates Colitis and Colitis-Associated Tumorigenesis.

Prostaglandin E2 plays important roles in the maintenance of colonic homeostasis. The recently identified prostaglandin E receptor (EP) 4-associated protein (EPRAP) is essential for an anti-inflammatory function of EP4 signaling in macrophages in vitro. To investigate the in vivo roles of EPRAP, we examined the effects of EPRAP on colitis and colitis-associated tumorigenesis. In mice, EPRAP deficiency exacerbated colitis induced by dextran sodium sulfate (DSS) treatment. Wild-type (WT) or EPRAP-deficient recipients transplanted with EPRAP-deficient bone marrow developed more severe DSS-induced colitis than WT or EPRAP-deficient recipients of WT bone marrow. In the context of colitis-associated tumorigenesis, both systemic EPRAP null mutation and EPRAP-deficiency in the bone marrow enhanced intestinal polyp formation induced by azoxymethane (AOM)/DSS treatment. Administration of an EP4-selective agonist, ONO-AE1-329, ameliorated DSS-induced colitis in WT, but not in EPRAP-deficient mice. EPRAP deficiency increased the levels of the phosphorylated forms of p105, MEK, and ERK, resulting in activation of stromal macrophages in DSS-induced colitis. Macrophages of DSS-treated EPRAP-deficient mice exhibited a marked increase in the expression of pro-inflammatory genes, relative to WT mice. By contrast, forced expression of EPRAP in macrophages ameliorated DSS-induced colitis and AOM/DSS-induced intestinal polyp formation. These data suggest that EPRAP in macrophages functions crucially in suppressing colonic inflammation. Consistently, EPRAP-positive macrophages were also accumulated in the colonic stroma of ulcerative colitis patients. Thus, EPRAP may be a potential therapeutic target for inflammatory bowel disease and associated intestinal tumorigenesis.

Behavioral abnormalities and reduced norepinephrine in EP4 receptor-associated protein (EPRAP)-deficient mice.

EP4 receptor-associated protein (EPRAP) is a newly identified molecule that regulates macrophage activation. We recently demonstrated the presence of EPRAP in the mice brain; however, little is known about the function of EPRAP in this tissue. Therefore, we investigated the role of EPRAP in behavior and emotion using behavioral analysis in mice. In this study, we subjected EPRAP-deficient (KO) mice and wild-type C57BL/6 (WT) mice to a battery of behavioral tests. EPRAP-KO mice tended to have shorter latencies to fall in the wire hang test, but had normal neuromuscular strength. EPRAP-KO mice exhibited elevated startle responses and reduced pre-pulse inhibition. Compared with WT mice, EPRAP-KO mice increased depression-like behavior in the forced swim test. These abnormal behaviors partially mimic symptoms of depression, attention deficit hyperactivity disorder (ADHD) and schizophrenia. Methylphenidate administration increased locomotor activity less in EPRAP-KO mice than in WT mice. Finally, levels of norepinephrine were reduced in the EPRAP-KO mouse brain. These behavioral abnormalities in EPRAP-KO mice may result from the dysfunction of monoamines, in particular, norepinephrine. Our results suggest that EPRAP participates in the pathogenesis of various behavioral disorders.

EP4 Receptor-Associated Protein in Microglia Promotes Inflammation in the Brain.

Microglial cells play a key role in neuronal damage in neurodegenerative disorders. Overactivated microglia induce detrimental neurotoxic effects through the excess production of proinflammatory cytokines. However, the mechanisms of microglial activation are poorly understood. We focused on prostaglandin E2 type 4 receptor-associated protein (EPRAP), which suppresses macrophage activation. We demonstrated that EPRAP exists in microglia in the brain. Furthermore, EPRAP-deficient mice displayed less microglial accumulation, and intraperitoneal administration of lipopolysaccharide (LPS) led to reduced expression of tumor necrosis factor-α and monocyte chemoattractant protein-1 mRNA in the brains of EPRAP-deficient mice. Consistently, EPRAP-deficient microglia showed a marked decrease in the production of tumor necrosis factor-α and monocyte chemoattractant protein-1 induced by LPS treatment compared with wild-type controls. In addition, EPRAP deficiency decreased microglial activation and neuronal cell death induced by intraventricular injection of kainic acid. EPRAP deficiency impaired the LPS-induced phosphorylation of c-jun N-terminal kinase and p38 mitogen-activated protein kinase in microglia. The phosphorylation levels of mitogen-activated protein kinase kinase 4-which phosphorylates c-jun N-terminal kinase and p38 mitogen-activated protein kinase-were also decreased in EPRAP-deficient microglia after LPS stimulation. Although EPRAP in macrophages plays a role in the attenuation of inflammation, EPRAP promotes proinflammatory activation of microglia through mitogen-activated protein kinase kinase 4-mediated signaling and may be key to the deteriorating neuronal damage brought on by brain inflammation.

Dysregulated glycolysis as an oncogenic event.

Enhanced glycolysis in cancer, called the Warburg effect, is a well-known feature of cancer metabolism. Recent advances revealed that the Warburg effect is coupled to many other cancer properties, including adaptation to hypoxia and low nutrients, immortalisation, resistance to oxidative stress and apoptotic stimuli, and elevated biomass synthesis. These linkages are mediated by various oncogenic molecules and signals, such as c-Myc, p53, and the insulin/Ras pathway. Furthermore, several regulators of glycolysis have been recently identified as oncogene candidates, including the hypoxia-inducible factor pathway, sirtuins, adenosine monophosphate-activated kinase, glycolytic pyruvate kinase M2, phosphoglycerate mutase, and oncometabolites. The interplay between glycolysis and oncogenic events will be the focus of this review.

Safety and efficacy of sustained release of basic fibroblast growth factor using gelatin hydrogel in patients with critical limb ischemia.

As a form of therapeutic angiogenesis, we sought to investigate the safety and efficacy of a sustained-release system of basic fibroblast growth factor (bFGF) using biodegradable gelatin hydrogel in patients with critical limb ischemia (CLI). We conducted a phase I-IIa study that analyzed 10 CLI patients following a 200-µg intramuscular injection of bFGF-incorporated gelatin hydrogel microspheres into the ischemic limb. Primary endpoints were safety and transcutaneous oxygen pressure (TcO2) at 4 and 24 weeks after treatment. During the follow-up, there was no death or serious procedure-related adverse event. After 24 weeks, TcO2 (28.4 ± 8.4 vs. 46.2 ± 13.0 mmHg for pretreatment vs after 24 weeks, p < 0.01) showed significant improvement. Regarding secondary endpoints, the distance walked in 6 min (255 ± 105 vs. 318 ± 127 m, p = 0.02), the Rutherford classification (4.4 ± 0.5 vs. 3.1 ± 1.4, p = 0.02), the rest pain scale (1.7 ± 1.0 vs. 1.2 ± 1.3, p = 0.03), and the cyanotic scale (2.0 ± 1.1 vs. 0.9 ± 0.9, p < 0.01) also showed improvement. The blood levels of bFGF were within the normal range in all patients. A subanalysis of patients with arteriosclerosis obliterans (n = 7) or thromboangiitis obliterans (Buerger's disease) (n = 3) revealed that TcO2 had significantly improved in both subgroups. TcO2 did not differ between patients with or without chronic kidney disease. The sustained release of bFGF from biodegradable gelatin hydrogel may offer a safe and effective form of angiogenesis for patients with CLI.

Measuring motivation for medical treatment: confirming the factor structure of the Achievement Motivation Index for Medical Treatment (AMI-MeT).

BACKGROUND: Developments in chemotherapy have led to changes in cancer care in Japan, with the government promoting a transition to outpatient chemotherapy. This requires patients and their families to participate more actively in treatment than in the past. However, it remains unclear how patients' motivation for medical treatment affects clinical consultations with their physicians. To investigate this, we developed a psychological index called the Achievement Motive Index for Medical Treatment (AMI-MeT), which comprises self-derived achievement motivation (AMS) and achievement motivation derived from others (AMO). However, its factor structure has not yet been confirmed in populations other than healthy university students. Thus, the aims of this study were to confirm the factor structure of the AMI-MeT in other groups and to determine the convergent and divergent validity of the AMI-MeT. METHODS: The AMI-MeT was administered to university students (n = 414), apparently healthy workers (n = 154), and cancer patients (n = 51). Multi-group confirmatory factor analysis was conducted and the mean scores of the AMI-MeT were compared between the groups. Correlations between the AMI-MeT and the Self-Construal Scale, comprising independent self-construal (IndSC) and interdependent self-construal (InterSC) subscales, were investigated in another group of students (n = 335). RESULTS: The multi-group confirmatory factor analysis supported a two-factor structure of the AMI-MeT: the weak invariance model was the best fit for the data. The mean scores of the AMI-MeT in apparently healthy workers and cancer patients were significantly higher than that in students (P < .01). The correlation analysis revealed that AMS scores were associated with IndSC scores (r = .25, P < .01) and AMO scores with InterSC scores (r = .30, P < .01). CONCLUSION: The two-factor model of the AMI-MeT was deemed appropriate for all three groups, and the subscales of the AMI-MeT successfully reflected the self and other dimensions. The AMI-MeT appears to be an effective tool for measuring medical treatment motivation, making it useful in participant observational research on medical consultations for Japanese cancer treatment.

A pilot study of regenerative therapy using controlled release of recombinant human fibroblast growth factor for patients with pre-collapse osteonecrosis of the femoral head.

PURPOSE: We evaluated the safety and clinical outcomes of a single local administration of gelatin hydrogel impregnated with recombinant human fibroblast growth factor (rhFGF)-2 for the treatment of the precollapse stage of osteonecrosis of the femoral head (ONFH). METHODS: Patients with ONFH (precollapse stage ≤2) received a single local administration of 800 µg of rhFGF-2-impregnated gelatin hydrogel and were followed up for one year. The surgery was performed using a minimally invasive technique involving a 1-cm skin incision, and walking was allowed from day one postoperatively. The primary outcomes included occurrence of adverse events and complications. The secondary outcomes included changes in the Harris hip scores, visual analog scale for pain scores, University of California, Los Angeles (UCLA) activity scores, and radiological images. RESULTS: We included ten patients, of which five experienced 14 adverse events, including one complication from spinal anesthesia. However, patients completely recovered from all adverse events. The mean clinical scores significantly improved by one year postoperatively compared with the pre-operative scores (before vs. after: visual analog score for pain, 21.2 vs. 5.3 mm; UCLA activity score, 5.5 vs. 6.6; Harris hip score, 81.0 vs. 96.9 points). There was only one case of femoral head collapse; however, this occurred in a hip with extensive necrosis. Stage progression and collapse did not occur in the other nine cases. Computed tomography confirmed bone regeneration in the femoral heads. CONCLUSIONS: Clinical application of rhFGF-2-impregnated gelatin hydrogel for patients with precollapse ONFH was feasible and safe.

[Pharmacotherapeutic Treatment of Elderly Cancer Patients].

Age-specific analyses of mortality rates in Japan show that cancer was the leading cause of death for the age group 40-89 years in the year 2013. Although the crude mortality rate from cancer has recently increased, the age-adjusted cancer mortality rate has shown a decreasing trend. This suggests that the increases in the crude mortality rate may have been caused by the aging of the population. Cancer patients who are old present many comorbidities and newly diagnosed geriatric problems. Several tools provide determinants of survival in cancer patients who are old (including the comprehensive geriatric assessment [CGA]) in order to improve the quality of cancer care in this population.

Deacetylation of phosphoglycerate mutase in its distinct central region by SIRT2 down-regulates its enzymatic activity.

Substantially high rate of glycolysis, known as the Warburg effect, is a well-known feature of cancers, and emerging evidence suggests that it supports cancerous proliferation/tumor growth. Phosphoglycerate mutase (PGAM), a glycolytic enzyme, is commonly up-regulated in several cancers, and recent reports show its involvement in the Warburg effect. Here, a comprehensive analysis shows that PGAM is acetylated at lysines 100/106/113/138 in its central region, and a member of the Sirtuin family (class III deacetylase), SIRT2, is responsible for its deacetylation. Over-expression of SIRT2 or mutations at the acetylatable lysines of PGAM attenuates cancer cell proliferation with a concomitant decrease in PGAM activity. We also report that the acetyltransferase PCAF (p300/CBP-associated factor) interacts with PGAM and acetylates its C-terminus, but not the central region. As prior evidence suggests that SIRT2 functions as a tumor suppressor, our results would provide support for the mechanistic basis of this activity.

MicroRNA-33a/b in lipid metabolism ­ novel "thrifty" models.

MicroRNAs (miRNAs; miRs) are small non-protein-coding RNAs that negatively regulate gene expression. They bind to the 3' UTR of specific mRNAs and either inhibit translation or promote mRNA degradation. There is emerging evidence linking miR-33a/b to lipid homoeostasis, targeting ABCA1,SREBF1, etc and it would appear that they have acted as "thrifty genes" during evolution to maintain cholesterol levels both at the cellular and whole body level. As we are now living in a period of "satiation", miR-33a/b no longer seem to be useful and could be potential therapeutic targets for lipid disorders and/or atherosclerosis. In this review, we describe the current understanding of the function of miR-33a/b in lipid homeostasis, focusing on the "thrifty" aspect.

Aspirin augments the expression of Adenomatous Polyposis Coli protein by suppression of IKKß.

Aspirin has been widely used as analgesic, antipyretic and anti-inflammatory medicine for long. In addition to these traditional effects, clinical studies suggest that aspirin can protect against cancer, but its mechanism has not been explored. To unveil it, we identified the proteins up- or down-regulated after incubation with aspirin by using proteomics analysis with Nano-flow LC/MALDI-TOF system. Interestingly, the analysis identified the protein of Adenomatous Polyposis Coli (APC) as one of the most up-regulated protein. APC regulates cell proliferation or angiogenesis, and is widely known as a tumor-suppressing gene which can cause colorectal cancer when it is mutated. Western blots confirmed this result, and real-time PCR indicated it is transcriptionally regulated. We further tried to elucidate the molecular mechanism with focusing on IKKß. IKKß is the essential kinase in activation of nuclear factor-kappa B (NF-κB), major transcriptional factors that regulate genes responsible for inflammation or immune response. Previous reports indicated that aspirin specifically inhibits IKKß activity, and constitutively active form of IKKß accelerates APC loss. We found that aspirin suppressed the expression of IKKß, and the deletion of IKKß by siRNA increases the expression of APC in HEK294 cells. Finally, we observed similar effects of aspirin in human umbilical vein endothelial cells. Taken together, these results reveal that aspirin up-regulates the expression of APC via the suppression of IKKß. This can be a mechanism how aspirin prevents cancer at least in part, and a novel link between inflammatory NF-κB signaling and cancer.

The increase in prescriptions of bisphosphonates and the incidence proportion of osteonecrosis of the jaw after risk communication activities in Japan: a hospital-based cohort study.

PURPOSE: The purpose of this study was to investigate the impact of risk communication about bisphosphonate (BP)-related osteonecrosis of the jaw (ONJ) on the number of reported cases to the Drug Adverse Reactions Reporting System and on the incidence proportion of ONJ in a hospital-based cohort study in Japan. METHOD: We conducted a survey of the safety information on BP-related ONJ available from regulatory authorities, pharmaceutical manufacturers and academic associations. We also performed a trend analysis of a dataset from the Drug Adverse Reactions Reporting System and a sub-analysis, using previously constructed data from a retrospective cohort study. RESULTS: Risk communication from pharmaceutical manufacturers and academic associations began within 1 year after revisions were made to the package inserts, in October 2006. Twenty times more cases of ONJ have been reported to regulatory authority since 2007, compared with the period before 2007. In our cohort, the incidence proportion of ONJ during and after 2009 was four times greater than before 2009. During this period, BPs were frequently prescribed, whereas there was no increase in the use of alternative agents, such as selective estrogen receptor modulators. CONCLUSION: ONJ was increasingly diagnosed after risk communication efforts, but the impact of the communications was not clear. Safety notifications were diligently disseminated after the package insert was revised. However, there was no surveillance for ONJ before the revision.

Clinical effects of ghrelin on gastrointestinal involvement in patients with systemic sclerosis.

The majority of patients with systemic sclerosis (SSc) have gastrointestinal (GI) tract involvement, but therapies using prokinetic agents are usually unsatisfactory. Ghrelin stimulates gastric motility in healthy human volunteers. In this study, we investigated whether ghrelin could improve gastric emptying in patients with gastrointestinal symptoms due to SSc. The study was performed in a randomized, double-blind, placebo-controlled crossover fashion on two occasions. Ten SSc patients with GI tract involvement received an infusion of either ghrelin (5.0 µg/kg) or saline, and gastric emptying rate was evaluated by ¹³C-acetic acid breath test. Gastric emptying was significantly accelerated by ghrelin infusion in patients with SSc (ghrelin vs. saline: 43.3 ± 11.4 min vs. 53.4 ± 5.4 min, P=0.03). No serious adverse effects were observed. Our results suggest that ghrelin might represent a new therapeutic approach for GI tract involvement in patients with SSc.

An international survey of physicians regarding clinical trials: a comparison between Kyoto University Hospital and Seoul National University Hospital.

BACKGROUND: International clinical trials are now rapidly expanding into Asia. However, the proportion of global trials is higher in South Korea compared to Japan despite implementation of similar governmental support in both countries. The difference in clinical trial environment might influence the respective physicians' attitudes and experience towards clinical trials. Therefore, we designed a questionnaire to explore how physicians conceive the issues surrounding clinical trials in both countries. METHODS: A questionnaire survey was conducted at Kyoto University Hospital (KUHP) and Seoul National University Hospital (SNUH) in 2008. The questionnaire consisted of 15 questions and 2 open-ended questions on broad key issues relating to clinical trials. RESULTS: The number of responders was 301 at KUHP and 398 at SNUH. Doctors with trial experience were 196 at KUHP and 150 at SNUH. Among them, 12% (24/196) at KUHP and 41% (61/150) at SUNH had global trial experience. Most respondents at both institutions viewed clinical trials favorably and thought that conducting clinical trials contributed to medical advances, which would ultimately lead to new and better treatments. The main reason raised as a hindrance to conducting clinical trials was the lack of personnel support and time. Doctors at both university hospitals thought that more clinical research coordinators were required to conduct clinical trials more efficiently. KUHP doctors were driven mainly by pure academic interest or for their desire to find new treatments, while obtaining credits for board certification and co-authorship on manuscripts also served as motivation factors for doctors at SNUH. CONCLUSIONS: Our results revealed that there might be two different approaches to increase clinical trial activity. One is a social level approach to establish clinical trial infrastructure providing sufficient clinical research professionals. The other is an individual level approach that would provide incentives to encourage doctors to participate in and conduct clinical trials.

MicroRNA-33 encoded by an intron of sterol regulatory element-binding protein 2 (Srebp2) regulates HDL in vivo.

Sterol regulatory element-binding protein 2 (SREBP-2) transcription factor has been identified as a key protein in cholesterol metabolism through the transactivation of the LDL receptor and cholesterol biosynthesis genes. Here, we generated mice lacking microRNA (miR)-33, encoded by an intron of the Srebp2, and showed that miR-33 repressed the expression of ATP-binding cassette transporter A1 (ABCA1) protein, a key regulator of HDL synthesis by mediating cholesterol efflux from cells to apolipoprotein A (apoA)-I. In fact, peritoneal macrophages derived from miR-33-deficient mice showed a marked increase in ABCA1 levels and higher apoA-I-dependent cholesterol efflux than those from WT mice. ABCA1 protein levels in liver were also higher in miR-33-deficient mice than in WT mice. Moreover, miR-33-deficient mice had significantly higher serum HDL cholesterol levels than WT mice. These data establish a critical role for miR-33 in the regulation of ABCA1 expression and HDL biogenesis in vivo.