Mouse Cyp2c expression and zonation structure in the liver begins in the early neonatal stage.

In the adult liver, drug-metabolizing enzymes such as cytochrome P450 (CYP) efficiently metabolize drugs by forming an expression pattern called "zonation" structure around the central veins (CV). However, most previous studies on CYPs have focused on the expression levels of CYP mRNA and proteins in the whole liver. In this study, we analyzed not only the expression levels of Cyp2c family mRNAs and proteins in mice during fetal liver development, but also the relationship with their localization. In the whole fetal liver, Cyp2c mRNA and protein were hardly expressed. On the other hand, zonation analysis results showed that only some cells around the CV of the fetal liver expressed Cyp2c. In addition, the protein expression level of Cyp2c in the whole liver during the neonatal period started from postnatal day (P) 7 in both males and females, while the zonation was weakly formed from P5. This study suggested that fetal liver cannot metabolize Cyp2c substrate drugs transferred from mother to fetus due to the low expression of Cyp2c and unformed zonation. The expression level of Cyp2c protein in neonates was lower than that in adult liver, and the zonation structure was not clear, suggesting that drug metabolism was not sufficient. Furthermore, this study revealed that the expression level of Cyp2c does not correlate with the formation of zonation structures, because Cyp2c expression is found in hepatocytes near the CV even in the fetal and neonatal stages, when Cyp2c protein expression is hardly detectable in the whole liver.

An Myh11 single lysine deletion causes aortic dissection by reducing aortic structural integrity and contractility.

Pathogenic variants in myosin heavy chain (Myh11) cause familial thoracic aortic aneurysms and dissections (FTAAD). However, the underlying pathological mechanisms remain unclear because of a lack of animal models. In this study, we established a mouse model with Myh11 K1256del, the pathogenic variant we found previously in two FTAAD families. The Myh11∆K/∆K aorta showed increased wall thickness and ultrastructural abnormalities, including weakened cell adhesion. Notably, the Myh11∆K/+ mice developed aortic dissections and intramural haematomas when stimulated with angiotensin II. Mechanistically, integrin subunit alpha2 (Itga2) was downregulated in the Myh11∆K/∆K aortas, and the smooth muscle cell lineage cells that differentiated from Myh11∆K/∆K induced pluripotent stem cells. The contractility of the Myh11∆K/∆K aortas in response to phenylephrine was also reduced. These results imply that the suboptimal cell adhesion indicated by Itga2 downregulation causes a defect in the contraction of the aorta. Consequently, the defective contraction may increase the haemodynamic stress underlying the aortic dissections.

Growth Differentiation Factor-15 Predicts Death and Stroke Event in Outpatients With Cardiovascular Risk Factors: The J-HOP Study.

Background Growth differentiation factor-15 (GDF-15) has emerged as a novel biomarker to predict all-cause death in community-dwelling individuals and patients with cardiovascular disease. We evaluated the prognostic value of GDF-15 in outpatients with cardiovascular risk factors. Methods and Results GDF-15 levels were measured in 3562 outpatients with cardiovascular risk factors in the J-HOP (Japan Morning Surge-Home Blood Pressure) study, a nationwide prospective study. Participants were stratified according to tertiles of GDF-15 and followed up for all-cause death and cardiovascular disease. During a mean follow-up period of 6.6 years, there were 155 all-cause deaths, 81 stroke events including cerebral infarction and intracranial hemorrhage, and 141 cardiac events including cardiac artery disease and heart failure. Patients with higher GDF-15 levels were associated with risks of all-cause death and stroke events (except for cardiac events) after adjustment for traditional risk factors and other prognostic biomarkers (NT-proBNP [N-terminal pro-B-type natriuretic peptide], high-sensitivity troponin T; all-cause death, hazard ratio, 2.38; 95% CI, 1.26-4.48; P=0.007; stroke events, hazard ratio, 2.93; 95% CI, 1.31-6.56, P=0.009; compared with the lowest tertile). Furthermore, incorporating GDF-15 to the predictive models for all-cause death improved discrimination and reclassification significantly. For stroke events, GDF-15 showed similar diagnostic accuracy to NT-proBNP and high-sensitivity troponin T. Conclusions In Japanese outpatients with cardiovascular risk factors, GDF-15 improves risk stratification for all-cause death when compared with NT-proBNP and high-sensitivity troponin T. GDF-15 was associated with increased risks of stroke events beyond conventional risk factors and other prognostic markers; however, the predictive ability for stroke events was equivalent to NT-proBNP and high-sensitivity troponin T. Registration URL: http://www.umin.ac.jp/ctr.; Unique identifier: UMIN000000894.

Growth Differentiation Factor 15 Predicts Cancer Death in Patients With Cardiovascular Risk Factors: The J-HOP Study.

Background: Disease-related anorexia-cachexia is associated with poor prognosis of patients with cardiovascular disease (CVD) or cancer. Growth differentiation factor-15 (GDF-15) has emerged as a central regulator of appetite and body weight. However, the exact role of GDF-15 in lean patients has not been elucidated. Aim: Our aim is to evaluate whether the association of GDF-15 with mortality, including cancer death, differs according to body mass index (BMI) level. Methods and Results: We collected blood samples from 4,061 patients with CV risk factors who were enrolled in the nationwide practice-based J-HOP (Japan Morning Surge-Home Blood Pressure) study. Serum GDF-15 levels were determined by immunoassay analysis. During a mean follow-up period of 6.6 years, we observed 174 (6.7/1000 person-year) all-cause deaths, 68 (2.6/1000 person-year) cancer deaths, and 56 (2.2/1000 person-year) CV deaths. Patients were stratified according to the cut-points of GDF-15 at 1,200 ng/L and BMI at 22.5 and 25.0 kg/m2. The association between the GDF-15/BMI based study groups and each outcome was evaluated by Cox-proportional hazard models with adjustment for established risk factors. The multivariate Cox regression model showed that patients with elevated GDF-15 (≥1,200 ng/L) and low BMI (<22.5 kg/m2) were significantly associated with increased risk of all outcomes [all-cause death, hazard ratio (HR) 3.15, 95% confidence interval (CI) 1.85-5.34, p < 0.001; cancer death, HR 3.52, 95%CI 1.64-7.57, p = 0.001; CV death, HR 2.88, 95%CI 1.20-6.92, p = 0.018, respectively] compared to a reference group with non-elevated GDF-15 and normal BMI (22.5-25.0 kg/m2). In analyses of a subgroup with low BMI (<22.5 kg/m2), patients with elevated GDF-15 had 4.79-fold increased risk of cancer death and 11-fold greater risk of CV death when compared with patients with non-elevated GDF-15 (<1,200 ng/L) after adjustment for established risk factors. Conclusion: In patients with CV risk factors, GDF-15 was associated with all-cause, cancer, and CV death. This relationship was especially remarkable in patients with low BMI. The serum GDF-15 levels in patients with low BMI might be a useful marker to identify the potential for anorexia-cachexia associated with CVD and cancer.

Calcium phosphate microcrystals in the renal tubular fluid accelerate chronic kidney disease progression.

The Western pattern diet is rich not only in fat and calories but also in phosphate. The negative effects of excessive fat and calorie intake on health are widely known, but the potential harms of excessive phosphate intake are poorly recognized. Here, we show the mechanism by which dietary phosphate damages the kidney. When phosphate intake was excessive relative to the number of functioning nephrons, circulating levels of FGF23, a hormone that increases the excretion of phosphate per nephron, were increased to maintain phosphate homeostasis. FGF23 suppressed phosphate reabsorption in renal tubules and thus raised the phosphate concentration in the tubule fluid. Once it exceeded a threshold, microscopic particles containing calcium phosphate crystals appeared in the tubule lumen, which damaged tubule cells through binding to the TLR4 expressed on them. Persistent tubule damage induced interstitial fibrosis, reduced the number of nephrons, and further boosted FGF23 to trigger a deterioration spiral leading to progressive nephron loss. In humans, the progression of chronic kidney disease (CKD) ensued when serum FGF23 levels exceeded 53 pg/mL. The present study identified calcium phosphate particles in the renal tubular fluid as an effective therapeutic target to decelerate nephron loss during the course of aging and CKD progression.

Ethnic differences in association of outcomes with trimethylamine N-oxide in acute heart failure patients.

AIMS: The aim of this study was to investigate whether ethnicity influences the associations between trimethylamine N-oxide (TMAO) levels and heart failure (HF) outcomes. METHODS AND RESULTS: Trimethylamine N-oxide levels were measured in two cohorts with acute HF at two sites. The UK Leicester cohort consisted mainly of Caucasian (n = 842, 77%) and South Asian (n = 129, 12%) patients, whereas patients in the Japanese cohort (n = 116, 11%) were all Japanese. The primary endpoint was the measurement of all-cause mortality and/or HF rehospitalization within 1 year post-admission. Association of TMAO levels with outcome was compared in the entire population and between ethnic groups after adjustment for clinical parameters. TMAO levels were significantly higher in Japanese patients [median (interquartile range): 9.9 µM (5.2-22.8)] than in Caucasian [5.9 µM (3.6-10.8)] and South Asian [4.5 µM (3.1-8.4)] (P < 0.001) patients. There were no differences in the rate of mortality and/or HF rehospitalization between the ethnic groups (P = 0.096). Overall, higher TMAO levels showed associations with mortality and/or rehospitalization after adjustment for confounders ( P = 0.002). Despite no differences between ethnicity and association with mortality/HF after adjustment (P = 0.311), only in Caucasian patients were TMAO levels able to stratify for a mortality/HF event (P < 0.001). CONCLUSIONS: Differences were observed in the association of mortality and/or rehospitalization based on circulating TMAO levels. Elevated TMAO levels in Caucasian patients showed increased association with adverse outcomes, but not in non-Caucasian patients.

Direct Comparison of Home Versus Ambulatory Defined Nocturnal Hypertension for Predicting Cardiovascular Events: The Japan Morning Surge-Home Blood Pressure (J-HOP) Study.

The home blood pressure monitoring (HBPM) method that measures blood pressure during sleep hours was reported to be comparable to ambulatory blood pressure monitoring (ABPM) in measuring nighttime blood pressure and detecting nocturnal hypertension. The aim of this study was to directly compare the prognostic power of nocturnal hypertension detected by HBPM versus ABPM for predicting future cardiovascular events. We analyzed nighttime blood pressure (measured by HBPM and ABPM) data of 1005 participants who were included in the J-HOP study (Japan Morning Surge-Home Blood Pressure). During a follow-up period of 7.6±3.4 years, 80 cardiovascular disease events occurred. The majority (91.8%) of our study population were hypertensive, and 80.7% of participants were using antihypertensive medication. Nighttime home systolic blood pressure (SBP) was higher compared to nighttime ambulatory SBP (123.0±14.6 versus 120.3±14.4 mm Hg, P<0.001). Nocturnal hypertension was defined as nighttime home or ambulatory SBP of ≥120 mm Hg. The number of participants with nocturnal hypertension defined by HBPM and ABPM was 564 (56.1%) and 469 (46.7%), respectively. Nocturnal hypertension defined by HBPM was associated with increased risk of future cardiovascular events: total cardiovascular events (coronary artery disease and stroke events; 1.78 [1.00-3.15]) and stroke (2.65 [1.14-6.20]), independent of office SBP. These results were absent with nocturnal hypertension defined by ABPM. This is the first comparison prospective study illustrating that uncontrolled nocturnal hypertension defined by HBPM (independent of office SBP) is a predictor of future cardiovascular events.

Age-related difference of the association of cardiovascular risk factors with the cardio-ankle vascular index in the Cardiovascular Prognostic Coupling Study in Japan (the Coupling Registry).

The value of the cardio-ankle vascular index (CAVI) increases with age. All large-scale studies of the CAVI have investigated patients <80 years old. Thus, the clinical characteristics of high CAVI in patients aged 80 or more remain unclear. Therefore, we investigated (1) the CAVI in very elderly patients and (2) the determinants of a high CAVI in high-risk patients, including very elderly patients. The Cardiovascular Prognostic Coupling Study in Japan (Coupling Registry) is a prospective observational study of Japanese outpatients with any cardiovascular risk factors. We enrolled 5109 patients from 30 institutions (average age 68.7 ± 11.4 years, 52.4% males). We investigated the determinants of the CAVI by separating the patients into three groups: 970 middle-aged (<60 years), 3252 elderly (60-79 years), and 887 very elderly (≥80 years) patients. The CAVI values of the males were significantly higher those of the females in all age groups (<60 years: 7.81 ± 1.11 vs. 7.38 ± 0.99, P < .001; 60-79 years: 9.20 ± 1.29 vs. 8.66 ± 1.07, P < .001; ≥80 years: 10.26 ± 1.39 vs. 9.51 ± 1.12, P < .001). In all age groups, the CAVI of the patients with diabetes/glucose tolerance disorder was higher than that of the patients without diabetes/glucose tolerance disorder (<60 years: 7.82 ± 1.22 vs 7.58 ± 1.03, P = .002; 60-79 years: 9.23 ± 1.20 vs 8.78 ± 1.19, P < .001; ≥80 years: 10.04 ± 1.24 vs 9.75 ± 1.32, P = .002). The determinants of the CAVI in these very elderly patients were age, male sex, low BMI, and mean blood pressure. Diabetes/glucose tolerance disorder and glucose were independently associated with the CAVI in the patients aged <60 years and 60-79 years, but not in those aged ≥80 years after adjusting for other covariates.

Rationale, design, and baseline characteristics of the Cardiovascular Prognostic COUPLING Study in Japan (the COUPLING Registry).

Vascular biomarkers, including the cardio-ankle vascular index (CAVI), are increasingly being recognized as important indicators of cardiovascular risk. CAVI has been shown to have good discriminative ability for detecting new-onset hypertension, but results of studies investigating cardiovascular risk prediction are inconsistent. Furthermore, there is a lack of data on the prognostic value of changes in CAVI over time. The Cardiovascular Prognostic Coupling study was designed to determine the impact of baseline CAVI and changes in CAVI on cardiovascular events in a Japanese cohort. The design of the ongoing, multicenter, prospective, observational registry and baseline characteristics of the enrolled population are reported. Eligible consecutive patients were aged ≥30 years, had ≥1 cardiovascular risk factor, and were being treated according to relevant Japanese guidelines. The primary outcome is time to onset of a major cardiovascular event (a composite of cerebral infarction, cerebral hemorrhage, subarachnoid hemorrhage, stroke of unknown etiology, myocardial infarction, cardiovascular intervention for angina pectoris, and sudden death). Screening and enrollment occurred over a period of 3 years, followed by ≥7 years of follow-up, with CAVI determined annually. A total of 5279 patients were registered, of whom 5109 had baseline data available and will be included in future analyses. Mean CAVI at baseline was 8.8 ± 1.4. The proportion of patients with CAVI of <8, 8-10 or >10 was 25.3%, 57.0%, and 17.7%, respectively. Data from this registry should provide information on the significance of baseline CAVI and change in CAVI as indicators of cardiovascular prognosis in a representative patient population.