Keisuke Fukuo

Apop-1, a novel protein inducing cyclophilin D-dependent but Bax/Bak-related channel-independent apoptosis

In the intrinsic pathway of apoptosis, mitochondria play a crucial role by releasing cytochrome c from the intermembrane space into the cytoplasm. Cytochrome c release through Bax/Bak-dependent channels in mitochondria has been well documented. In contrast, cyclophilin D (CypD), an important component of permeability transition pore-dependent protein release, remains largely undefined, and no apoptogenic proteins that act specifically in a CypD-dependent manner have been reported to date. Here, we describe a novel and evolutionarily conserved protein, apoptogenic protein (Apop). Mouse Apop-1 expression induces apoptotic death by releasing cytochrome c from mitochondria into the cytosolic space followed by activation of caspase-9 and -3. Apop-1-induced apoptosis is not blocked by Bcl-2 or Bcl-xL, inhibitors of Bax/Bak-dependent channels, whereas it is completely blocked by cyclosporin A, an inhibitor of permeability transition pore. Cells lacking CypD were resistant to Apop-induced apoptosis. Moreover, inhibition of Apop expression prevented the cell death induced by apoptosis-inducing substances. Our findings, thus, indicate that the expression of Apop-1 induces apoptosis though CypD-dependent pathway and that Apop-1 plays roles in cell death under physiological conditions.

Tissue Inhibitor of Metalloproteinase-3 Deficiency Inhibits Blood Pressure Elevation and Myocardial Microvascular Remodeling Induced by Chronic Administration of N^ω-Nitro-L-Arginine Methyl Ester in Mice

Hypertension is a major risk factor for cardiovascular disease. Thus, prevention of hypertension and consequent organ damage is important for reducing its incidence. In the present study, we examined the involvement of tissue inhibitor of metalloproteinase-3 (Timp-3) in Nω-nitro-L-arginine methyl ester (L-NAME)−induced hypertension and accompanying vascular remodeling in mice. L-NAME was orally administered to wild-type (WT) and Timp-3 knockout (KO) mice for 6 weeks, blood pressure was monitored, and histological changes in myocardial arteries were examined. After L-NAME administration, blood pressure was lower in Timp-3 KO mice than in WT mice. The coronary arteries of WT and Timp-3 KO mice were similar after L-NAME treatment and showed no differences compared to untreated control mice. However, cardiac microvessels differed histologically between WT and Timp-3 KO mice. Vascular walls were less thickened in Timp-3 KO than in WT mice, and fibrotic changes were significantly reduced in Timp-3 KO mice. Moreover, the L-NAME–induced production of reactive oxygen species in cardiac microvessels was lower in Timp-3 KO than in WT mice. These results indicate that Timp-3 plays an important role in L-NAME–induced hypertension and myocardial vascular remodeling. Our findings suggest that Timp-3 may be a novel therapeutic target for the treatment of hypertension and consequent organ damage.

Tissue Inhibitor of Metalloproteinase-3 Plays Important Roles in the Kidney Following Unilateral Ureteral Obstruction

Tissue inhibitor of metalloproteinase-3 (Timp-3), an inhibitor of matrix-degrading enzymes, is an important molecule for maintenance of the extracellular matrix. In this study, we generated Timp-3−deficient mice and used them to examine the effect of Timp-3-deficiency on blood pressure and to investigate the role of Timp-3 in the kidney following unilateral ureteral obstruction. The blood pressure and heart rate of Timp-3−deficient mice were not significantly different from those of wild-type mice. On the other hand, the obstructed kidneys of Timp-3−deficient mice developed more severe hydronephrosis than those of wild-type animals. Matrix metalloproteinase activities assessed by in situ zymography and transforming growth factor-β expression were elevated in Timp-3−deficient mice. The renal tissues were thinner and the ratio of renal medulla to cortex was significantly lower in the obstructed Timp-3−deficient kidneys. These findings indicate that Timp-3-deficiency does not substantially affect the blood pressure in mice, and that Timp-3 plays an important role in the maintenance of renal macrostructure after unilateral ureteral obstruction.

Direct association of visit-to-visit HbA1c variation with annual decline in estimated glomerular filtration rate in patients with type 2 diabetes.

Background/AimsThis study examined associations of visit-to-visit variability of glycemic control with annual decline in estimated glomerular filtration rate (eGFR) in patients with type 2 diabetes attending an outpatient clinic.MethodsIntrapersonal mean and coefficient of variation (CV) of 8-12 measurements of HbA1c and those of 4-6 measurements of fasting and post-breakfast plasma glucose (FPG and PPG, respectively) during the first 12 months after enrollment were calculated in a cohort of 168 patients with type 2 diabetes. Annual changes in eGFR were computed using 52 (median) creatinine measurements obtained over a median follow-up of 6.0 years. Multivariate linear regressions assessed the independent correlates of changes in eGFR.ResultsCV-HbA1c (standardized β、-0.257、pu2009=u20090.004) were significantly and log urine albumin/creatinine ratio (standardized β、-0.155、pu2009=u20090.085) and smoking (standardized β、-0.186、pu2009=u20090.062) tended to be associated with annual eGFR decline independently of mean HbA1c, age, sex, BMI, waist circumference, diabetes duration and therapy, means and CVs of FPG, PPG and systolic blood pressure, baseline eGFR, and uses of anti-hypertensive and lipid-lowering medications. Association between HbA1c variability and renal function decline was stronger in patients with albumin/creatinine ratio ≧ 30 mg/g than in those with normoalbuminuria (ru2009=u2009-0.400, pu2009=u20090.003 and ru2009=u2009-0.169, pu2009=u20090.07, respectively).ConclusionsConsistency of glycemic control is important to preserve kidney function in type 2 diabetic patients, in particular, in those with nephropathy.

Timp-3 deficiency impairs cognitive function in mice

Extracellular matrix (ECM) degradation is performed primarily by matrix metalloproteinases (MMPs). MMPs have recently been shown to regulate synaptic activity in the hippocampus and to affect memory and learning. The tissue inhibitor of metalloproteinase (Timp) is an endogenous factor that controls MMP activity by binding to the catalytic site of MMPs. At present, four Timp isotypes have been reported (Timp-1 through Timp-4) with 35–50% amino-acid sequence homology. Timp-3 is a unique member of Timp proteins in that it is bound to the ECM. In this study, we used the passive avoidance test, active avoidance test, and water maze test to examine the cognitive function in Timp-3 knockout (KO) mice. Habituation was evaluated using the open-field test. The water maze test showed that Timp-3 KO mice exhibit deterioration in cognitive function compared with wild-type (WT) mice. The open-field test showed decreased habituation of Timp-3 KO mice. Immunostaining of brain slices revealed the expression of Timp-3 in the hippocampus. In situ zymography of the hippocampus showed increased gelatinolytic activity in Timp-3 KO mice compared with WT mice. These results present the first evidence of Timp-3 involvement in cognitive function and hippocampal MMP activity in mice. Moreover, our findings suggest a novel therapeutic target to be explored for improvement of cognitive function in humans.

Fas Ligand mRNA Levels of Circulating Leukocytes Reflect Endothelial Dysfunction in Hyperlipidemic but Not in Non-Hyperlipidemic Patients

To find a novel marker for identifying patients at high-risk for endothelial dysfunction among patients with atherosclerosis, we examined the correlation between mRNA levels of Fas ligand (FasL), an apoptosis-inducing factor, in circulating leukocytes and clinical parameters in these patients. FasL mRNA levels of circulating leukocytes were measured with the TaqMan-PCR method. A negative correlation was observed between brachial artery flow-mediated dilatation (%FMD) and FasL mRNA levels of leukocytes in hyperlipidemic but not in non-hyperlipidemic patients. %FMD was more impaired in patients with a high level of FasL mRNA than in those with a low level of FasL mRNA. Interestingly, the improvement of %FMD by treatment with a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor (simvastatin) was greater in the group showing a decrease in FasL mRNA than in the group with no such decrease. Additionally, simvastatin suppressed the FasL mRNA expression in leukocytes and decreased plasma oxidized low-density lipoprotein (OxLDL) levels. Furthermore, the supernatant of cultured leukocytes from hyperlipidemic patients induced cell death in Jurkat T cells, which was neutralized by an antibody against FasL. These findings suggest that high FasL mRNA expression in circulating leukocytes may be a marker of high-risk for endothelial dysfunction in hyperlipidemic but not in non-hyperlipidemic patients. This information may provide a novel basis for targeting of statin therapy in patients with vulnerable plaques.

Association of Metabolic Syndrome with Serum Adipokines in Community-Living Elderly Japanese Women: Independent Association with Plasminogen Activator-Inhibitor-1

BACKGROUNDnAssociations between metabolic syndrome (MetS) with serum adipokines and basal lipoprotein lipase mass (serum LPL) have not been extensively studied in elderly Asians, who in general have lower body mass index than European populations.nnnMETHODSnA cross-sectional analysis was conducted including 159 community-living elderly Japanese women whose age averaged 77 years. MetS was defined by the modified National Cholesterol Education Program Adult Treatment Panel III criteria, but using a body mass index ≥25u2009kg/m(2) instead of waist circumference. Serum LPL, leptin, adiponectin, plasminogen activator inhibitor 1 (PAI-1), interleukin-6, tumor necrosis factor-alpha, and high-sensitivity C-reactive protein were measured.nnnRESULTSnBoth the presence of MetS and the number of MetS components were associated with higher homeostasis assessment of insulin resistance, serum levels of leptin, PAI-1, and tumor necrosis factor-alpha and with lower serum levels of LPL and adiponectin (all Pu2009<u20090.05), but not with high-sensitivity C-reactive protein and interleukin-6. Among six biomarkers of MetS, PAI-1 remained associated with MetS independent of fat mass index and insulin resistance.nnnCONCLUSIONSnAlthough proinflammatory, prothrombotic, and anti-inflammatory states were associated with MetS, higher PAI-1 was associated with MetS independent of fat mass index and insulin resistance in elderly Japanese women, in whom obesity is rare.

Association of Cystatin C with Leptin and TNF-α in Elderly Japanese Women

BACKGROUND AND OBJECTIVESnDeterminants of cystatin C, a novel marker of mortality in the elderly, have not been extensively studied in Asian elderly population.nnnMETHODS AND STUDY DESIGNnAssociations of cystatin C with anthropometric, cardiometabolic, hematological, nutritional variables and inflammatory markers were examined in 159 community-living elderly Japanese women whose BMI averaged 22.6±2.9 (SD) kg/m2.nnnRESULTSnSerum creatinine and cystatin C averaged 0.73±0.16 mg/dL and 0.85±0.20 mg/L, respectively. Creatinine-based estimated glomerular filtration rate (standardized β, -0.538, p<0.001), age (standardized β, 0.274, p<0.001), serum leptin (standardized β, 0.218, p<0.001) and tumour necrosis factor-α (TNF-α, standardized β, 0.165, p=0.002) emerged as significant predictors of serum cystatin C independent of percentage body fat, homeostasis model assessment of insulin resistance, high-sensitivity C-reactive protein, systolic blood pressure and HDL cholesterol (cumulative R2=0.674).nnnCONCLUSIONSnElevated serum levels of leptin and TNF-α contributed to elevated cystatin C independent of kidney function, fat mass, insulin resistance and inflammation in community-living elderly women and may represent confounders of associations between cystatin C and mortality in this population.

Different changes of bone mineral density and nutritional status after hospitalization between vascular dementia and Alzheimer's disease in elderly female patients

Background:u2003 Bone fractures strongly influence morbidity and mortality in elderly patients with dementia. The goal of this study was to examine whether difference in the type of dementia affects changes of bone mineral density (BMD) during hospitalization with rehabilitation programs.

Postmeal triglyceridemia and variability of HbA1c and postmeal glycemia were predictors of annual decline in estimated glomerular filtration rate in type 2 diabetic patients with different stages of nephropathy

BackgroundThis study examined associations of annual glycemic variability and postprandial dysmetabolism with annual decline in estimated glomerular filtration rate (eGFR) in type 2 diabetic patients with different stages of nephropathy.MethodsIntrapersonal mean and coefficient of variation (CV) of HbA1c, fasting and postmeal concentrations of plasma glucose (FPG and PMPG, respectively) and serum triglycerides (FTG and PMTG, respectively) during the first 12xa0months after enrollment were calculated in a cohort of 168 type 2 diabetic patients: 53 with optimal albumin/creatinine ratio (ACRu2009<u200910xa0mg/g), 62 with high normal ACR (10–29xa0mg/g) and 53 with elevated ACR (≧30xa0mg/g). Annual changes in eGFR were computed using 52 (median) creatinine measurements obtained over a median follow-up of 6.0xa0years. Multivariate linear regressions assessed the independent correlates of changes in eGFR.ResultsKidney function declined faster in patients with high normal and elevated ACR (−1.47 and −2.01xa0ml/min/1.73xa0m2/year, respectively) compared to patients with optimal ACR (0.08xa0ml/min/1.73xa0m2/year, pu2009<u20090.05). In patients with high normal ACR, age (standardized β、-0.30、pu2009=u20090.01), CV-HbA1c (standardized β、-0.66、pu2009<u20090.001) and CV-PMPG (standardized β、-0.27、pu2009=u20090.01) was associated with annual eGFR decline independently of mean HbA1c and PMPG, sex, BMI, waist circumference, diabetes duration and therapy, means and CVs of FPG and systolic blood pressure, baseline eGFR, log ACR and uses of anti-hypertensive medications (R2u2009=u20090.47). In patients with elevated ACR, PMTG (standardized β、-0.408, pu2009=u20090.007) was associated with annual eGFR decline (R2u2009=u20090.15).ConclusionsConsistency of glycemic control and management of postprandial glycemia and lipidemia are important to preserve kidney function in type 2 diabetic patients.