Predictive Factors for the Development or Regression of Fatty Liver in Japanese Adults

Fatty liver is commonly associated with alcohol or metabolic syndrome. We aimed to examine the longitudinal aspects of fatty liver, and clarify the independent predictors for the development or regression of fatty liver. In the present study, the clinical features of 1578 Japanese adults (1208 men and 370 women; 35 to 69 years of age) who visited our center both in 2000 and 2007–2008 were recorded and compared, including liver status diagnosed by ultrasonography. Of the 1578 participants, 217 (13.8%) showed fatty liver development, and 74 (4.7%) showed fatty liver regression. Logistic regression analysis revealed that body mass index and percentage body fat were strongly associated with the development or regression of fatty liver. Metabolic syndrome-related disorders such as serum levels of total cholesterol, triglyceride, uric acid, and fasting blood glucose were also associated with clinical course to some degree. However, the history of alcohol intake, the presence of metabolic syndrome, blood pressure, and habitual physical exercise were not independent predictors for the development or regression of fatty liver. Our present data suggest that control of body weight in men and the percentage body fat in women are particularly important for the prevention or treatment of fatty liver.     

Development of packaging cell lines for generation of adeno-associated virus vectors by lentiviral gene transfer of trans-complementary components

Adeno-associated virus (AAV) vector system has several useful advantages with regard to in vitro and in vivo gene transfer. However, their usages have been limited by cumbersome and labor-intensive vector production in the traditional method. To overcome limitations in AAV production, in this report, we explored the possibility of generating AAV packaging cell line, 293T R/C.VA.E2A.E4. cells, by using lentivirus-mediated transduction of Rep/Cap gene of AAV-2, VA RNA, E2A, and E4 genes of Ad5 into 293T cells. In packaging cell lines, it is important that supply of the AAV vector can be stably performed for long time. We showed that the 293T R/C.VA.E2A.E4. cells have stably maintained the transduced components after more than 10 passages and yielded high-titer AAV vectors, and the titer of AAV vectors did not decline even if culture of the packaging cells was continued for long time. The Rep/Cap and E4 gene products caused no remarkable cytotoxicity. The 293T R/C.VA.E2A.E4. cells might be able to tolerate the Rep/Cap and E4 gene products, or have less copy numbers of the Rep/Cap and E4 genes than the traditional method. Moreover, we showed that the AAV vectors derived from 293T R/C.VA.E2A.E4. cells infected the primary human CD34+ haematopoietic progenitor cells with high efficiency (50-70%). In the 293T R/C.VA.E2A.E4. cells, the AAV vectors can be generated by the transfection of one AAV vector plasmid, and large-scale AAV production can be easily achieved. It is important that cumbersome, variable, and costly transfection is avoided.     

An Exploratory Study of Dapagliflozin for the Attenuation of Albuminuria in Patients with Heart Failure and Type 2 Diabetes Mellitus (DAPPER)

Background and Aims

Sodium-dependent glucose transporter-2 (SGLT-2) inhibitors, which are anti-diabetic drugs, reportedly decrease the incidence of cardiovascular events in high-risk patients with cardiovascular diseases, and thus chronic heart failure (CHF). SGLT-2 inhibitors also decrease albuminuria in patients with type 2 diabetes mellitus (T2D). Since albuminuria is a biomarker of not only chronic kidney disease but also cardiovascular events, we hypothesized that, among T2D patients with CHF, SGLT-2 inhibitors will decrease the extent of albuminuria and also improve CHF concomitantly.

Methods

DAPPER (UMIN000025102) is a multicenter, randomized, open-labeled, parallel-group, standard treatment-controlled study, which is designed to evaluate whether dapagliflozin, one of the SGLT-2 inhibitors, decreases albuminuria in T2D patients with CHF and exerts cardioprotective effects on the failing heart. The patients are randomized to either of the dapagliflozin (5 or 10 mg, once daily orally) or control group (administration of anti-diabetic drugs administered other than SGLT 2 inhibitors). The estimated number of patients that need to be enrolled is 446 in total (223 in each group). The primary objective is the changes in the urinary albumin-to-creatinine ratio from the baseline after 2-year treatment. The key secondary objectives are (1) the safety of dapagliflozin and (2) the cardiovascular and renal efficacies of dapagliflozin.

Conclusion and Perspectives

DAPPER study investigates whether dapagliflozin decreases albuminuria and exerts beneficial effects on the failing heart in T2D patients. (UMIN000025102).

     

Mitochondrial K<Subscript>ATP</Subscript> channel-dependent and -independent phases of ischemic preconditioning against myocardial infarction in the rat

To obtain insight into the role of the mitochondrial ATP-sensitive K(+) (mitoK(ATP)) channel in ischemic preconditioning (PC), we aimed to clarify the mitoK(ATP) channel-dependent phase of PC in two PC protocols with different intervals between PC ischemia and an index ischemia. The possible contribution of mitoK(ATP) channel opening to protein kinase C activation in PC was also examined by Western blotting. Myocardial infarction was induced by 30-min coronary occlusion/2-h reperfusion in rat hearts in situ, and infarct size was expressed as a percentage of the area at risk (% IS/AR). PC was performed with 2 episodes of 5-min ischemia, and each heart was subjected to 30-min ischemia either 5 min or 20 min after PC. At 5 min after PC, both PKC-delta and -epsilon were translocated and the myocardium was protected against infarction (% IS/AR = 28.3 +/- 2.7 % vs. 72.7 +/- 2.2 in controls p < 0.05). Pretreatment with a selective mitoK(ATP) channel blocker, 5-hydroxydecanoate (5-HD, 10 mg/kg), abolished the cardioprotection but not PKC translocation by PC. At 20 min after PC, PKC translocation remained at the same level as that 5 min after PC, but the anti-infarct tolerance was attenuated (%IS/AR = 43.5 +/- 4.7 %). Injection of 5-HD after PC did not affect anti-infarct tolerance at 5 min after PC but abolished the protection at 20 min after PC without any effects on PKC. These results suggest that the mitoK(ATP) channel plays a role in triggering of PC in a PKC-independent manner and that the role of the mitoK(ATP) channel as a mediator of protection is detectable after, but not before, the PC effect starts to decay without a change in the level of PKC translocation in the rat heart.     

Altered relationship between body fat and plasma adiponectin in end-stage renal disease

Patients with end-stage renal disease (ESRD) show an inverse association between body mass index and risk of death from cardiovascular disease. Paradoxical epidemiology may suggest some beneficial effects of body fat in ESRD. Because an antiatherogenic adipocytokine adiponectin is increased in uremic plasma, we tested a hypothesis that, in ESRD, plasma adipocytokine profile may be less atherogenic or that the relationship between body fat and adipocytokines may be altered. The subjects were 103 patients with ESRD undergoing hemodialysis and 166 healthy subjects comparable in age and sex. We measured body fat mass by dual-energy x-ray absorptiometry and plasma levels of adiponectin and leptin by enzyme-linked immunosorbent assay. The ESRD group showed a significant increase in plasma adiponectin, leptin, and adiponectin/leptin ratio than the healthy subjects. Although sex and fat mass were significant factors correlating with plasma adiponectin level in the healthy group, none of these were significantly associated with plasma adiponectin in the patients with ESRD. In contrast, leptin showed significant relationships with sex and fat mass regardless of the presence of ESRD. Plasma adiponectin correlated negatively with plasma triglycerides and positively with high-density lipoprotein cholesterol in both healthy and ESRD groups, suggesting that uremic adiponectin retains its actions in favor of its antiatherogenicity. Thus, plasma adipocytokine profile was altered in ESRD, and the effects of body fat and sex on adiponectin were less significant in the patients with ESRD.     

Infarct Size Limitation by Bradykinin Receptor Activation Is Mediated by the Mitochondrial But Not by the Sarcolemmal KATP Channel

Earlier studies have shown that activation of bradykinin B₂ receptor triggers protein kinase C (PKC)-mediated cardioprotective mechanism in ischemic preconditioning (PC). In the present study, we examined whether the effector in this B₂-receptor triggered pathway of PC is the ATP sensitive potassium (K_ATP) channel in the mitochondria (mito-K_ATP channel) or K_ATP channel in the sarcolemma (sarc-K_ATP channel). Isolated rabbit hearts were perfused with modified Krebs-Henseleit buffer in a Langendorff mode, and regional myocardial ischemia was induced by occluding a left coronary artery for 30 min and then reperfusing for 2 hours. Infarct size was determined by triphenyltetrazolium chloride staining and expressed as a percentage of area at risk (% IS/AR). Infusion of bradykinin (500 nmol/L) for 15 min prior to ischemia significantly reduced % IS/AR from 37.4 ± 2.9 (SE) of the untreated controls to 12.0 ± 3.3%. This protective effect of bradykinin was completely abolished by coinfusion of 5-hydroxydecanoate (5-HD, 50 mol/L), a selective mito-K_ATP channel blocker (% IS/AR = 44.2 ± 6.4). In contrast, a high dose of HMR1098 (20 mol/L), which is a newly developed sarc-K_ATP channel selective blocker with IC₅₀ of 0.6 mol/L, failed to modify the infarct size limitation by preischemic infusion of bradykinin (% IS/AR = 11.7 ± 3.4). Neither 5-HD nor HMR1098 alone modified infarct size (% IS/AR = 37.8 ± 3.8 and 35.1 ± 6.2, respectively). These results suggest that opening of the mito-K_ATP channel but not the sarc-K_ATP channel is involved in infarct size limitation by a mechanism triggered by bradykinin B₂ receptor activation.