BACKGROUND: Mitochondria, which harbor their own genome (mtDNA), have attracted attention due to the potential of mtDNA copy number (mtDNA-CN) as an indicator of mitochondrial dysfunction. Although mtDNA-CN has been proposed as a simple and accessible biomarker for metabolic disorders such as metabolic dysfunction-associated steatotic liver disease, the underlying mechanisms and the causal relationship remain insufficiently elucidated. In this investigation, we combined longitudinal epidemiological data, animal studies, and in vitro assays to elucidate the potential causal relationship between reduced mtDNA-CN and the development of steatotic liver disease (SLD). METHODS: We conducted a longitudinal study using data from a health examination cohort initiated in 1981 in Yakumo, Hokkaido, Japan. Data from examinations performed in 2015 and 2022 were analyzed, focusing on 76 subjects without SLD at baseline (2015) to assess the association between baseline mtDNA-CN and subsequent risk of SLD development. In addition, 28-day-old SD rats were fed ad libitum on a 45% high-fat diet and dissected at 2 and 8 weeks of age. Blood and liver mtDNA-CN were measured and compared at each feeding period. Additionally, in vitro experiments were performed using HepG2 cells treated with mitochondrial function inhibitors to induce mtDNA-CN depletion and to examine its impact on intracellular lipid accumulation. RESULTS: Epidemiological analysis showed that the subjects with low mtDNA-CN had a significantly higher odds ratio for developing SLD compared to high (odds ratio [95% confidence interval]: 4.93 [1.08-22.50]). Analysis of the animal model showed that 8 weeks of high-fat diet led to the development of fatty liver and a significant decrease in mtDNA-CN. A further 2 weeks of high-fat diet consumption resulted in a significant decrease in hepatic mtDNA-CN, despite the absence of fatty liver development, and a similar trend was observed for blood. Complementary in vitro experiments revealed that pharmacologically induced mitochondrial dysfunction led to a significant reduction in mtDNA-CN and was associated with increases in intracellular lipid accumulation in HepG2 cells. CONCLUSIONS Our findings suggest that reduced mtDNA-CN may contribute causally to SLD development and could serve as a convenient, noninvasive biomarker for early detection and risk assessment.
Animals ; DNA, Mitochondrial/genetics* ; Humans ; Male ; DNA Copy Number Variations ; Female ; Fatty Liver/blood* ; Rats ; Middle Aged ; Longitudinal Studies ; Rats, Sprague-Dawley ; Adult ; Japan/epidemiology* ; Aged ; Biomarkers/blood* ; Hep G2 Cells ; Diet, High-Fat/adverse effects*

BACKGROUND: Pneumonia is a major global public health concern. Taking antioxidant nutrients has attracted attention for their potential role in reducing pneumonia mortality. Although studies in Western countries have evaluated this association, the current evidence remains controversial, and research in Asia remains limited. This cohort study investigated the association between dietary antioxidant nutrients intake and pneumonia mortality in Japanese population. METHODS: Data were collected from the Japan Public Health Center-based Prospective Study between 1995 and 1998, with follow-up until the end of 2018. The intake of antioxidant nutrients was assessed using a validated food-frequency questionnaire. The Cox proportional hazard model was employed to calculate hazard ratios (HRs) and p-trends for pneumonia mortality, adjusting for potential confounding factors including age, area, body mass index, smoking status, alcohol intake, physical activity, postmenopausal status, occupation, coffee intake, green tea intake, antihypertensive medication use, vitamin-supplement use, and total energy intake. RESULTS: The analysis included data from 39,850 men and 46,705 women. Over a median follow-up of 20.8 years, 813 men and 477 women died from pneumonia. The multivariable model revealed that a higher intake of cryptoxanthin (p-trend = 0.027 in men; 0.019 in women), lycopene (p-trend = 0.016 in women), vitamin C (p-trend = 0.022 in men), and vitamin E (p-trend = 0.031 in women) was significantly associated with a reduction in pneumonia mortality. CONCLUSIONS Higher dietary intake of cryptonxanthin, lycopene, and vitamins C and E was associated with a low risk of pneumonia mortality in Japanese adults.
Humans ; Male ; Japan/epidemiology* ; Female ; Prospective Studies ; Middle Aged ; Pneumonia/mortality* ; Antioxidants/administration & dosage* ; Diet/statistics & numerical data* ; Aged ; Adult ; Nutrients ; East Asian People

BACKGROUND: Meals are provided at nursery schools for Japanese preschool children, and this may result in different energy and nutrient intakes on weekdays and weekends. The purpose of this study was to obtain basic information for public nutrition policies in early childhood by examining differences in energy and nutrient intakes of preschool children between weekdays and weekends using meal categories such as breakfast, lunch, dinner, and snacks. METHODS: Energy and nutrient intakes were examined in 761 Japanese preschool children (423 boys, 338 girls) aged 3-6 years attending childcare facilities in seven regions in Japan. Data collection was based on non-consecutive four-day dietary records (two weekdays, two weekend days) in 2019 or 2020. Energy and nutrient intake by meal category were compared using a generalized linear mixed model adjusted for demographic factors. RESULTS: Total energy intake was significantly higher on weekdays for boys (1,478 vs. 1,415 kcal) and girls (1,349 vs. 1,296 kcal) (both P < 0.001). Weekday lunches had higher protein content and essential micronutrients such as potassium, iron, vitamins, and lower fat, saturated fatty acids, and salt, compared to weekend lunches. Similarly, weekday snacks also had significantly higher nutritional consumption for most nutrients compared to weekend equivalents. CONCLUSION These findings suggest that meals at nursery schools, particularly lunch and snacks, result in more desirable nutrient intake in preschool children. On weekdays, children consume meals with higher nutrient density, possibly due to the role of dietitians in menu planning. However, some children still fail to meet the Dietary Reference Intakes for Japanese, indicating a need for improvements in nursery school and home meals. More communication is needed between nursery schools and families, including sharing menus and recipes is essential. The results of this study are of value for development of public health nutrition strategies targeting early childhood.
Humans ; Child, Preschool ; Male ; Japan ; Female ; Energy Intake ; Meals ; Child ; Nutrients/analysis* ; Diet/statistics & numerical data* ; East Asian People

BACKGROUND: This cross-sectional study examined meal patterns based on daily energy intake distribution and their associations with nutrient and food intake, diet quality, and body mass index (BMI). METHODS: Body height, weight, habitual dietary intake and the Healthy Eating Index (HEI)-2020 score by eating occasion were assessed using the validated Meal-based Diet History Questionnaire among employees (465 males and 193 females aged 20-75 years) in the Tokyo Metropolitan Area. Meal patterns were extracted based on % energy intake from breakfast, lunch, dinner, and snacks using K-means clustering by sex. Dietary intake, HEI-2020 score, and BMI were then compared between sex-specific meal patterns. RESULTS: The identified patterns were "large lunch and dinner" (n = 299), "three meals-balanced" (n = 97), and "large dinner" (n = 69) patterns in males and "large dinner" (n = 79); "large afternoon snack" (n = 54) and "large lunch" (n = 60) patterns in females. The HEI-2020 scores were the highest for dinner, followed by breakfast, lunch, and snacks in any meal pattern. Males with the "large dinner" pattern had lower intakes of rice, bread, carbohydrates, dietary fibre, and thiamine; higher intake of alcoholic beverages; and higher HEI-2020 scores than those with other patterns. Females with a "large dinner" pattern had a lower intake of bread, confectionery, total and saturated fats, and carbohydrates; higher intake of fish, meat, and alcoholic beverages; higher HEI-2020 scores; and lower BMI. Thus, a meal pattern with higher energy intake distribution at dinner was associated with higher diet quality among males and females and lower BMI among females in Japanese workers. CONCLUSIONS These findings suggest that improving the quality of the meal with the highest energy contribution could help enhance overall dietary quality and metabolism.
Humans ; Female ; Male ; Middle Aged ; Adult ; Energy Intake ; Body Mass Index ; Cross-Sectional Studies ; Aged ; Meals ; Young Adult ; Tokyo ; Feeding Behavior ; Diet/statistics & numerical data*

OBJECTIVE: To investigate the therapeutic potential of pseudolaric acid B (PAB) on non-alcoholic fatty liver disease (NAFLD) and its underlying molecular mechanism in vitro and in vivo. METHODS: Eight-week-old male C57BL/6J mice (n=32) were fed either a normal chow diet (NCD) or a high-fat diet (HFD) for 8 weeks. The HFD mice were divided into 3 groups according to a simple random method, including HFD, PAB low-dose [10 mg/(kg·d), PAB-L], and PAB high-dose [20 mg/(kg·d), PAB-H] groups. After 8 weeks of treatment, glucose metabolism and insulin resistance were assessed by oral glucose tolerance test (OGTT) and insulin tolerance test (ITT). Biochemical assays were used to measure the serum and cellular levels of total cholesterol (TC), triglycerides (TG), aspartate aminotransferase (AST), alanine aminotransferase (ALT), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C). White adipose tissue (WAT), brown adipose tissue (BAT) and liver tissue were subjected to hematoxylin and eosin (H&E) staining or Oil Red O staining to observe the alterations in adipose tissue and liver injury. PharmMapper and DisGeNet were used to predict the NAFLD-related PAB targets. Peroxisome proliferator-activated receptor alpha (PPARα) pathway involvement was suggested by Kyoto Encyclopedia of Genes and Genomes (KEGG) and search tool Retrieval of Interacting Genes (STRING) analyses. Luciferase reporter assay, cellular thermal shift assay (CETSA), and drug affinity responsive target stability assay (DARTS) were conducted to confirm direct binding of PAB with PPARα. Molecular dynamics simulations were applied to further validate target engagement. RT-qPCR and Western blot were performed to assess the downstream genes and proteins expression, and validated by PPARα inhibitor MK886. RESULTS: PAB significantly reduced serum TC, TG, LDL-C, AST, and ALT levels, and increased HDL-C level in HFD mice (P<0.01). Target prediction analysis indicated a significant correlation between PAB and PPARα pathway. PAB direct target binding with PPARα was confirmed through luciferase reporter assay, CETSA, and DARTS (P<0.05 or P<0.01). The target engagement between PAB and PPARα protein was further confirmed by molecular dynamics simulations and the top 3 amino acid residues, LEU321, MET355, and PHE273 showed the most significant changes in mutational energy. Subsequently, PAB upregulated the genes expressions involved in lipid metabolism and mitochondrial biogenesis downstream of PPARα (P<0.05 or P<0.01). Significantly, the PPARα inhibitor MK886 effectively reversed the lipid-lowering and PPARα activation properties of PAB (P<0.05 or P<0.01). CONCLUSION PAB mitigates lipid accumulation, ameliorates liver damage, and improves mitochondrial biogenesis by binding with PPARα, thus presenting a potential candidate for pharmaceutical development in the treatment of NAFLD.
Animals ; PPAR alpha/metabolism* ; Non-alcoholic Fatty Liver Disease/pathology* ; Male ; Mice, Inbred C57BL ; Lipid Metabolism/drug effects* ; Diterpenes/therapeutic use* ; Organelle Biogenesis ; Diet, High-Fat ; Humans ; Mice ; Liver/metabolism* ; Insulin Resistance ; Mitochondria/metabolism* ; Molecular Docking Simulation

OBJECTIVES: Recent evidence suggests that the gut may be a primary site of metformin action. However, studies on the effects of metformin on gut microbiota remain limited, and its impact on gut microbial metabolites such as short-/medium-chain fatty acids is unclear. This study aims to investigate the effects of metformin on gut microbiota, short-/medium-chain fatty acids, and associated metabolic benefits in high-fat diet rats. METHODS: Twenty-four Sprague-Dawley rats were randomly divided into 3 groups: 1) Normal diet group (ND group), fed standard chow; 2) high-fat diet group (HFD group), fed a high-fat diet; 3) high-fat diet + metformin treatment group (HFD+Met group), fed a high-fat diet for 8 weeks, followed by daily intragastric administration of metformin solution (150 mg/kg body weight) starting in week 9. At the end of the experiment, all rats were sacrificed, and serum, liver, and colonic contents were collected for assessment of glucose and lipid metabolism, liver pathology, gut microbiota composition, and the concentrations of short-/medium-chain fatty acids. RESULTS: Metformin significantly improved HFD-induced glucose and lipid metabolic disorders and liver injury. Compared with the HFD group, the HFD+Met group showed reduced abundance of Blautia, Romboutsia, Bilophila, and Bacteroides, while Lactobacillus abundance significantly increased (all P<0.05). Colonic contents of butyric acid, 2-methyl butyric acid, valeric acid, octanoic acid, and lauric acid were significantly elevated (all P<0.05), whereas acetic acid, isoheptanoic acid, and nonanoic acid levels were significantly decreased (all P<0.05). Spearman correlation analysis revealed that Lactobacillus abundance was negatively correlated with body weight gain and insulin resistance, while butyrate and valerate levels were negatively correlated with insulin resistance and liver injury (all P<0.05). CONCLUSIONS Metformin significantly increases the abundance of beneficial bacteria such as Lactobacillus and promotes the production of short-/medium-chain fatty acids including butyric, valeric, and lauric acid in the colonic contents of HFD rats, suggesting that metformin may regulate host metabolism through modulation of the gut microbiota.
Animals ; Metformin/pharmacology* ; Rats, Sprague-Dawley ; Diet, High-Fat/adverse effects* ; Rats ; Gastrointestinal Microbiome/drug effects* ; Male ; Fatty Acids, Volatile/metabolism* ; Fatty Acids/metabolism*

OBJECTIVES: To investigate the regulatory role of nucleotide-bound oligomerized domain-like receptor containing pyrin-domain protein 6 (NLRP6) in liver lipid metabolism and non-alcoholic fatty liver disease (NAFLD). METHODS: Mouse models with high-fat diet (HFD) feeding for 16 weeks (n=6) or with methionine choline-deficient diet (MCD) feeding for 8 weeks (n=6) were examined for the development of NAFLD using HE and oil red O staining, and hepatic expressions of NLRP6 were detected with RT-qPCR, Western blotting, and immunohistochemical staining. Cultured human hepatocytes (LO2 cells) with adenovirus-mediated NLRP6 overexpression or knock-down were treated with palmitic acid (PA) in the presence or absence of compound C (an AMPK inhibitor), and the changes in cellular lipid metabolism were examined by measuring triglyceride, ATP and β-hydroxybutyrate levels and using oil red staining, RT-qPCR, and Western blotting. RESULTS: HFD and MCD feeding both resulted in the development of NAFLD in mice, which showed significantly decreased NLRP6 expression in the liver. In PA-treated LO2 cells, NLRP6 overexpression significantly decreased cellular TG content and lipid deposition, while NLRP6 knockdown caused the opposite effects. NLRP6 overexpression in PA-treated LO2 cells also increased mRNA and protein expressions of PGC1A and CPT1A, levels of ATP and β-hydroxybutyrate, and the phosphorylation level of AMPK pathway; the oxidative decomposition of lipids induced by Ad-NLRP6 was inhibited by the use of AMPK inhibitors. CONCLUSIONS NLRP6 overexpression promotes lipid oxidation and decomposition through AMPK/CPT1A/PGC1A to alleviate lipid deposition in hepatocytes.
Non-alcoholic Fatty Liver Disease/metabolism* ; Animals ; Hepatocytes/metabolism* ; Lipid Metabolism ; Mice ; Humans ; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha ; AMP-Activated Protein Kinases/metabolism* ; Carnitine O-Palmitoyltransferase/metabolism* ; Diet, High-Fat ; Male ; Mice, Inbred C57BL ; Signal Transduction

OBJECTIVES: To investigate the role of activating transcription factor 3 (ATF3) in atherosclerotic plaques for regulating inflammatory responses during atherosclerosis (AS) progression. METHODS: Human coronary artery specimens from autopsy cases were examined for ATF3 protein expression and localization using immunofluorescence staining and Western blotting. Apolipoprotein E-deficient (ApoE^-/-) mouse models of AS induced by high-fat diet (HFD) feeding for 12 weeks were subjected to tail vein injection of adeno-associated virus serotype 9 (AAV9) to knock down ATF3 expression. After an additional 5 weeks of HFD feeding, the mice were euthanized for analyzing structural changes of the aortic plaques, and the expression levels of ATF3, inflammatory factors (CD45, CD68, IL-1β, and TNF-α), and NF-κB pathway proteins (P-IKKα/β and P-NF-κB p65) were detected. In the cell experiment, THP-1-derived foam cells were transfected with an ATF3-overexpressing plasmid or an ATF3-specific siRNA to validate the relationship between ATF3 and NF‑κB signaling. RESULTS: In human atherosclerotic plaques, ATF3 expression was significantly elevated and partially co-localized with CD68. ATF3 knockout in ApoE^-/- mice significantly increased aortic plaque volume, upregulated the inflammatory factors, enhanced phosphorylation of the NF‑κB pathway proteins, and increased the expressions of VCAM1, MMP9, and MMP2 in the plaques. In THP-1-derived foam cells, ATF3 silencing caused activation of the NF‑κB pathway, while ATF3 overexpression suppressed the activity of the NF-κB pathway. CONCLUSIONS AS promotes ATF3 expression, and ATF3 deficiency exacerbates AS progression by enhancing plaque inflammation via activating the NF-κB pathway, suggesting the potential of ATF3 as a therapeutic target for AS.
Animals ; Activating Transcription Factor 3/metabolism* ; Signal Transduction ; NF-kappa B/metabolism* ; Humans ; Mice ; Plaque, Atherosclerotic/metabolism* ; Inflammation/metabolism* ; Apolipoproteins E ; Atherosclerosis/metabolism* ; Diet, High-Fat

OBJECTIVES: To investigate the therapeutic effect of electroacupuncture (EA) at Zusanli (ST36) acupoint on hyperlipidemia in mice and explore the underlying mechanisms. METHODS: Thirty C57BL/6J mice were equally randomized into normal diet group, high-fat diet (HFD) group, and EA group. The changes in blood lipids and serum malondialdehyde (MDA) content of the mice were evaluated, and histopathological changes and lipid accumulation in the liver were observed using Oil red O staining (ORO). The expressions of NLRP3, TLR4, and IL-1β proteins in the colon tissues were detected with Western blotting, and gut microbiota changes were analyzed using 16S rDNA sequencing. RESULTS: In mice with HFD feeding, 16 weeks of EA treatment significantly lowered body weight and serum TC, TG, LDL-C and MDA levels, obviously reduced lipid accumulation in the liver, and ameliorated HFD-induced elevations of protein expressions of NLRP3, TLR4, and IL-1β. 16S rRNA sequencing revealed that EA significantly altered gut microbiota composition, and increased the diversity and relative abundance of beneficial bacterial groups such as Muribaculaceae and Lachnospiraceae NK4A136_group. CONCLUSIONS Electroacupuncture at ST36 alleviates blood lipid disorders in hyperlipidemic mice possibly by improving intestinal microbiota structure, promoting degradation of high-caloric carbohydrates, cholesterol lipid metabolism and intestinal mucosa repair, and reducing toxin leakage, lipid peroxides, and liver fat deposition.
Animals ; Electroacupuncture ; Gastrointestinal Microbiome ; Hyperlipidemias/blood* ; Mice, Inbred C57BL ; Mice ; Diet, High-Fat ; Toll-Like Receptor 4/metabolism* ; NLR Family, Pyrin Domain-Containing 3 Protein ; Acupuncture Points ; Male ; Lipids/blood* ; Interleukin-1beta/metabolism* ; Liver/metabolism*

OBJECTIVES: To explore the molecular mechanism of Jiangzhi Huaban Decoction (JZHBD) for improving atherosclerosis through the "qi meridian-blood channels" pathway. METHODS: ApoE^-/- mouse models of atherosclerosis were established by high-fat diet feeding for 8 weeks, with C57BL/6 mice on a normal diet as the controls. Forty ApoE^-/- mouse models were randomized into model group, low-, medium-, and high-dose JZHBD treatment groups, and atorvastatin treatment group (n=8) for their respective treatments for 8 weeks. The changes in body weight and overall condition of the mice were monitored weekly. After the treatments, serum levels of TC, TG, HDL-C, LDL-C, TBA, ALT, and AST of the mice were measured, pathological changes in the liver and aortic root plaques were examined with HE staining, and lipid accumulation in the liver and aortic wall was assessed using Oil Red O staining. The core molecular mechanism was studied through transcriptomics, and the expressions of the key pathway proteins were confirmed using Western blotting and immunohistochemistry. RESULTS: Treatment with JZHBD significantly reduced blood lipid and total bile acid levels, improved liver function and hepatic steatosis, and decreased aortic lipid deposition and plaque area in the mouse models of atherosclerosis. Transcriptomic analysis suggested that the therapeutic mechanism of JZHBD involved reverse cholesterol transport, PPAR signaling, and the inflammatory pathways. In atherosclerotic mice, JZHBD treatment obviously up-regulated hepatic expressions of PPARγ, LXRα, ABCA1, ABCG1, and CYP7A1, down-regulated hepatic expressions of p-p65/p65, IL-6, IL1β in the liver, increased ABCG5 and ABCG8 expressions in the intestines, and decreased ICAM-1 and VCAM-1 expressions in the aortic plaques. CONCLUSIONS JZHBD improves atherosclerotic vascular damage and plaque formation possibly by regulating hepatic reverse cholesterol transport and inflammation via modulating the hepatic PPARγ/LXRα/NF-κB signaling pathway.
Animals ; Drugs, Chinese Herbal/therapeutic use* ; Mice, Inbred C57BL ; Plaque, Atherosclerotic/metabolism* ; Liver/metabolism* ; Mice ; Atherosclerosis/metabolism* ; Cholesterol/metabolism* ; PPAR gamma/metabolism* ; Male ; Diet, High-Fat ; Biological Transport