NF-E2-related factor 2 (Nrf2) is a key transcription factor that is critical for cellular defense against oxidative and xenobiotic insults. Nrf2 heterodimerizes with small Maf (sMaf) proteins and ...binds to antioxidant response elements (AREs) to activate a battery of cytoprotective genes. However, it remains unclear to what extent the Nrf2-sMaf heterodimers contribute to ARE-dependent gene regulation on a genome-wide scale. We performed chromatin immunoprecipitation coupled with high-throughput sequencing and identified the binding sites of Nrf2 and MafG throughout the genome. Compared to sites occupied by Nrf2 alone, many sites co-occupied by Nrf2 and MafG exhibit high enrichment and are located in species-conserved genomic regions. The ARE motifs were significantly enriched among the recovered Nrf2-MafG-binding sites but not among the Nrf2-binding sites that did not display MafG binding. The majority of the Nrf2-regulated cytoprotective genes were found in the vicinity of Nrf2-MafG-binding sites. Additionally, sequences that regulate glucose metabolism and several amino acid transporters were identified as Nrf2-MafG target genes, suggesting diverse roles for the Nrf2-MafG heterodimer in stress response. These data clearly support the notion that Nrf2-sMaf heterodimers are complexes that regulate batteries of genes involved in various aspects of cytoprotective and metabolic functions through associated AREs.
According to recent reports, individuals with reduced aldehyde dehydrogenase activity may require more energy for the detoxification of aldehydes. Aldehyde dehydrogenase 2 (ALDH2), an ALDH isozyme, ...is responsible for detoxifying acetaldehyde, an intermediate metabolite of ethanol. Because the variant allele of the rs671 polymorphism of ALDH2 results in a substantial reduction in enzymatic activity, carriers of this variant allele may have a higher energy demand when consuming alcohol than non-carriers. However, no studies have evaluated this phenomenon to date.
To test the hypothesis, we statistically examined the interactive effects between the rs671 and ethanol consumption on energy intake using cross-sectional data from a population-based cohort study, the Japan Multi-Institutional Collaborative Cohort Study, which was conducted in Saga city between 2005-2007 (N = 12,068).
General linear regression models adjusted for age, sex, ethanol consumption, current smoking status, years of education, dietary restriction, medical history, and physical activity level revealed that energy intake was higher in variant allele carriers than in non-carriers among individuals with alcohol drinking habits, whereas no such correlation was observed among those without drinking habits (≤2 g ethanol/day) (p = 0.03 for interaction between rs671 and ethanol consumption). Energy intake excluding energy from alcoholic beverages, carbohydrate intake, protein intake, and fat intake, showed similar tendencies (p for interaction = 0.01, 0.01, 0.04, and 0.07, respectively).
These findings support the hypothesis that increased energy intake is required for the detoxification of aldehydes in individuals with low ALDH activity. This epidemiological evidence provides a possible scientific basis for understanding aldehyde detoxification mechanisms and suggests a novel phenotype of the ALDH2 rs671 polymorphism.
Background: Selection of test-negative controls takes less time and costs less than traditional control selection for evaluating vaccine effectiveness (VE). Here, rotavirus VE was evaluated using ...hospital controls and compared with test-negative controls to determine whether using the latter can substitute for the former. Methods: We recorded gastroenteritis in children from 2 months to 2 years of age at six medical facilities in Saga City between January 4th and May 31st, 2014. Stools from all identified acute gastroenteritis patients were tested for rotavirus using immunochromatography. Rotavirus gastroenteritis (RVGE) cases had test-positive stool, whereas test-negative controls had gastroenteritis but no rotavirus infection; hospital controls were outpatients visiting the same facility for indications other than gastroenteritis. Vaccination status was verified by inspecting maternal and child health records, and demographic data were obtained from a questionnaire completed by the patients’ guardians or from the medical records. Unconditional logistic regression analysis was used to adjust for possible confounding factors. Results: Sixty-four RVGE cases, 260 test-negative controls, and 589 hospital controls were enrolled. The characteristics of the two control groups, including RV vaccination history, were similar. The RVGE cases were more likely to have used daycare services than children from either of the two control groups. The VE against RVGE estimated using hospital controls was 86.6% (95% confidence interval CI, 55.9–96.0%), very similar to the VE using test-negative controls (84.9% 95% CI, 49.6–95.5%). Conclusions: The estimated VE using test-negative controls and hospital controls is similar. Therefore, test-negative controls are considered appropriate for establishing VE.
Aim
The aim of the current study is to examine whether home‐based step exercise at anaerobic threshold (AT) and branched‐chain amino acid (BCAA) supplementation improve aerobic capacity, ectopic fat ...in liver and muscle, and glycemic control in patients with liver cirrhosis.
Methods
Six female patients with compensated liver cirrhosis received oral BCAA and were instructed to undertake bench step exercises at an intensity that corresponded to AT, with a goal of performing 140 min of exercise per week at home for 12 months. Fat deposition in liver (liver to spleen ratio) and intramuscular adipose tissue content were assessed at baseline and after 6 and 12 months by computed tomography. Glycemic control indices (homeostasis model assessment of insulin resistance, hemoglobin A1c HbA1c, glycated albumin GA and chronic liver disease CLD‐HbA1c average of HbA1c and GA/3) were also measured.
Results
Twelve months of moderate training significantly increased AT, which is an index of aerobic capacity, but no changes were observed in body weight, liver to spleen ratio, or intramuscular adipose tissue content. Glycated albumin significantly decreased (P < 0.05) and there tended to be a similar decrease in CLD‐HbA1c (P < 0.1) after the exercise. The baseline serum triglyceride level correlated with changes in GA (P < 0.01) and CLD‐HbA1c (P < 0.1).
Conclusion
The current results suggest that the combination of home‐based step exercise at AT and BCAA supplementation enhances aerobic capacity and potentially improves glycemic control in patients with cirrhosis without changes in body weight. The baseline serum serum triglyceride may partially explain the degree of improvement in glycemic control with exercise and BCAA intervention.
Introduction
Overexpression of lipoprotein lipase (LPL) protects against high-fat-diet (HFD)-induced obesity and insulin resistance in transgenic rabbits; however, the molecular mechanisms remain ...unclear. Skeletal muscle is a major organ responsible for insulin-stimulated glucose uptake and energy expenditure.
Objectives
The main purpose of the current study was to examine the effects of the overexpression of LPL on the skeletal muscle metabolomic profiles to test our hypothesis that the mitochondrial oxidative metabolism would be activated in the skeletal muscle of LPL transgenic rabbits and that the higher mitochondrial oxidative metabolism activity would confer better phenotypic metabolic outcomes.
Methods
Under a HFD, insulin resistance index was measured using the intravenous glucose tolerance test, and total energy expenditure (TEE) was measured by doubly-labeled water in control and LPL transgenic rabbits (n = 12, each group). Serum lipids, such as triglycerides and free fatty acid, were also measured. The skeletal muscle metabolite profile was analyzed using capillary electrophoresis time-of flight mass spectrometry in the two groups (n = 9, each group). A metabolite set enrichment analysis (MSEA) with muscle metabolites and a false discovery rate q < 0.2 was performed to identify significantly different metabolic pathways between the 2 groups.
Results
The triglycerides and free fatty acid levels and insulin resistance index were lower, whereas the TEE was higher in the LPL transgenic rabbits than in the control rabbits. Among 165 metabolites detected, the levels of 37 muscle metabolites were significantly different between the 2 groups after false discovery rate correction (q < 0.2). The MSEA revealed that the TCA cycle and proteinogenic amino acid metabolism pathways were significantly different between the 2 groups (
P
< 0.05). In the MSEA, all four selected metabolites for the TCA cycle (2-oxoglutaric acid, citric acid, malic acid, fumaric acid), as well as eight selected metabolites for proteinogenic amino acid metabolism (asparagine, proline, methionine, phenylalanine, histidine, arginine, leucine, isoleucine) were consistently increased in the transgenic rabbits compared with control rabbits, suggesting that these two metabolic pathways were activated in the transgenic rabbits. Some of the selected metabolites, such as citric acid and methionine, were significantly associated with serum lipids and insulin resistance (
P
< 0.05).
Conclusion
The current results suggest that the overexpression of LPL may lead to increased activities of TCA cycle and proteinogenic amino acid metabolism pathways in the skeletal muscle, and these enhancements may play an important role in the biological mechanisms underlying the anti-obesity/anti-diabetes features of LPL overexpression.
Oncogenic signaling pathways regulate gene expression in part through epigenetic modification of chromatin including DNA methylation and histone modification. Trimethylation of histone H3 at ...lysine-27 (H3K27), which correlates with transcriptional repression, is regulated by an oncogenic form of the small GTPase Ras. Although accumulation of trimethylated H3K27 (H3K27me3) has been implicated in transcriptional regulation, it remains unclear whether Ras-induced changes in H3K27me3 are a trigger for or a consequence of changes in transcriptional activity. We have now examined the relation between H3K27 trimethylation and transcriptional regulation by Ras. Genome-wide analysis of H3K27me3 distribution and transcription at various times after expression of oncogenic Ras in mouse NIH 3T3 cells identified 115 genes for which H3K27me3 level at the gene body and transcription were both regulated by Ras. Similarly, 196 genes showed Ras-induced changes in transcription and H3K27me3 level in the region around the transcription start site. The Ras-induced changes in transcription occurred before those in H3K27me3 at the genome-wide level, a finding that was validated by analysis of individual genes. Depletion of H3K27me3 either before or after activation of Ras signaling did not affect the transcriptional regulation of these genes. Furthermore, given that H3K27me3 enrichment was dependent on Ras signaling, neither it nor transcriptional repression was maintained after inactivation of such signaling. Unexpectedly, we detected unannotated transcripts derived from intergenic regions at which the H3K27me3 level is regulated by Ras, with the changes in transcript abundance again preceding those in H3K27me3. Our results thus indicate that changes in H3K27me3 level in the gene body or in the region around the transcription start site are not a trigger for, but rather a consequence of, changes in transcriptional activity.
Daily step counts are an easy-to-understand indicator of physical activity; however, there is limited evidence regarding the optimal daily step count to prevent sarcopenia. This study examined the ...dose-response relationship between daily step count and the prevalence of sarcopenia and explored the optimal dose.
Cross-sectional study.
The study included 7949 community-dwelling middle-aged and older adults (aged 45–74 years) from Japan.
Skeletal muscle mass (SMM) was assessed using bioelectrical impedance spectroscopy, and muscle strength was quantified through handgrip strength (HGS) measurement. Participants who exhibited both low HGS (men: <28 kg, women: <18 kg) and low SMM (lowest quartile in each sex-specific category) were defined as having sarcopenia. Daily step counts were measured for 10 days using a waist-mounted accelerometer. To examine the association between daily step count and sarcopenia, a multivariate logistic regression analysis was performed, adjusting for potential confounding factors such as age, sex, body mass index, smoking status, alcohol consumption, protein intake, and medical history. The odds ratios (ORs) and confidence intervals (CIs) were calculated based on the daily step counts categorized into quartiles (Q1-Q4). Finally, a restricted cubic spline curve was fitted to further investigate the dose-response relationship between daily step count and sarcopenia.
The prevalence of sarcopenia in the overall participants was 3.3 % (259/7949 participants), with a mean daily step count of 7292 ± 2966 steps. Expressed in quartiles, the mean daily step counts were 3873 ± 935 steps in Q1, 6025 ± 503 steps in Q2, 7942 ± 624 steps in Q3, and 11,328 ± 1912 steps in Q4. The prevalence of sarcopenia in each quartile of daily step count was 4.7 % (93/1987 participants) in Q1, 3.4 % (68/1987 participants) in Q2, 2.7 % (53/1988 participants) in Q3, and 2.3 % (45/1987 participants) in Q4. The ORs and 95 % CIs adjusted for covariates demonstrated a statistically significant inverse association between daily step count and sarcopenia prevalence (P for trend <0.01), as follows: Q1, reference; Q2, 0.79 (95 % CI: 0.55–1.11); Q3, 0.71 (95 % CI: 0.49–1.03); Q4, 0.61 (95 % CI: 0.41–0.90). The restricted cubic spline curve indicated that the ORs leveled off at approximately 8000 steps per day, and no statistically significant decrease in ORs was observed for daily step counts above this threshold.
The study found a significant inverse association between daily step count and the prevalence of sarcopenia, with the association plateauing when the daily step count exceeded approximately 8000 steps. These findings suggest that 8000 steps per day may be the optimal dose to prevent sarcopenia. Further intervention and longitudinal studies are needed to validate the results.
•Study aims to find dose-response relationship between daily steps and sarcopenia prevalence.•Inverse association found between step count and sarcopenia prevalence.•Dose-response relationship plateaus at approximately 8,000 steps.•Results suggest 8,000 daily steps as optimal dose to prevent sarcopenia.
Centrioles are cylindrical microtubule-based structures whose assembly is critical for the formation of cilia, flagella, and centrosomes. The centriole proximal region harbors a cartwheel that ...dictates the 9-fold symmetry of centrioles. Although the cartwheel architecture has been recently analyzed, how it connects to the peripheral microtubules is not understood. More generally, a high-resolution view of the proximal region of the centriole is lacking, thus limiting understanding of the underlying assembly mechanisms.
We report the complete architecture of the Trichonympha centriole proximal region using cryotomography. The resulting 3D map reveals several features, including additional densities in the cartwheel that exhibit a 9-fold symmetrical arrangement, as well as the structure of the Pinhead and the A-C linker that connect to microtubules. Moreover, we uncover striking chiral features that might impart directionality to the entire centriole. Furthermore, we identify Trichonympha SAS-6 and demonstrate that it localizes to the cartwheel in vivo.
Our work provides unprecedented insight into the architecture of the centriole proximal region, which is key for a thorough understanding of the mechanisms governing centriole assembly.
•Complete architecture of Trichonympha proximal centriole•The CID might facilitate 9-fold symmetrization of the cartwheel•The Pinhead and the A-C linker exhibit chiral features•TaSAS-6 assembles into rings in the cartwheel
This study aims to characterize the housekeeping and tissue-specific genes in 15 mouse tissues by using the serial analysis of gene expression (SAGE) strategy which indicates the relative level of ...expression for each transcript matched to the tag.
Here, we identified constantly expressed housekeeping genes, such as eukaryotic translation elongation factor 2, which is expressed in all tissues without significant difference in expression levels. Moreover, most of these genes were not regulated by experimental conditions such as steroid hormones, adrenalectomy and gonadectomy. In addition, we report previously postulated housekeeping genes such as peptidyl-prolyl cis-trans isomerase A, glyceraldehyde-3-phosphate dehydrogenase and beta-actin, which are expressed in all the tissues, but with significant difference in their expression levels. We have also identified genes uniquely detected in each of the 15 tissues and other tissues from public databases.
These identified housekeeping genes could represent appropriate controls for RT-PCR and northern blot when comparing the expression levels of genes in several tissues. The results reveal several tissue-specific genes highly expressed in testis and pituitary gland. Furthermore, the main function of tissue-specific genes expressed in liver, lung and bone is the cell defence, whereas several keratins involved in cell structure function are exclusively detected in skin and vagina. The results from this study can be used for example to target a tissue for agent delivering by using the promoter of tissue-specific genes. Moreover, this study could be used as basis for further researches on physiology and pathology of these tissues.
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