[Mechanism of inhibitory effect of catalpol on TNF-α induced HAECs cell damage].

Catalpol is an iridoid glycoside extracted from the root of Rehmannia glutinosa. It has been reported to have antioxidant stress effects. Adenosine 5' monophosphate-activated protein kinase( AMPK) plays an important role in inhibiting oxidative stress. This study was designed to investigate the protective effects of catalpol on TNF-α-exposed human aorta epithelial cells( HAECs) via inhibit oxidative stress,and the relationship between catalpol and AMPK was detected by RNA interference technique. Levels of superoxide dismutase( SOD),malonaldehyde( MDA),glutathione( GSH) and lactate dehydrogenase( LDH) were measured with a colorimetric assay kit. The level of ROS was measured with FACS calibur. Western blot was employed to detect the protein expression of AMPK,phosphorylated-AMPK and NOX4. Finally,RNA interference technique was used to investigate the role of AMPK in catalpol-induced protective effects. TNF-α treatment decreased the expression of phosphorylated-AMPK protein level,however,catalpol could reverse the decreased phosphorylated-AMPK level. Catalpol could inhibit NOX4 protein expression and decrease ROS overproduction. After using AMPK siRNA that effects of catalpol on ROS overproduction and NOX4 protein expression inhibition were attenuated. The above results suggest that catalpol inhibits oxidative stress in TNF-α-exposed HAECs by activating AMPK.

Lung ultrasonography for the diagnosis of 11 patients with acute respiratory distress syndrome due to bird flu H7N9 infection.

BACKGROUND: A novel reassortant avian-origin influenza A (H7N9) virus was found to infect three Chinese residents, the first H7N9 infection in humans in Asia. Chest computed tomography (CT) for acute respiratory distress syndrome (ARDS) diagnosis is not only expensive but also exposes patients to radiation and might cause patients to be at risk of infection during transportation; in addition, chest radiography cannot be used to monitor the lung repeatedly in real time. Therefore, the routine use of bedside lung ultrasonography for critically ill patients with ARDS is especially valuable. OBJECTIVES: The aim of this study was to evaluate the application of ultrasound for lung examination in patients with ARDS. METHODS: Eleven patients infected with H7N9 avian influenza who developed ARDS were diagnosed by lung ultrasonography. RESULTS: Six patients who had severe ARDS showed a diffuse comet tail sign or a consolidation score ≥ 7 and a lung ultrasound score ≥ 20 points. A diffuse comet tail sign or a consolidation score ≤ 6 and a lung ultrasound score < 25 were observed in four patients. One patient showed a diffuse comet tail sign or consolidation area in four lung areas, with an ultrasound score of 14. Among all 11 patients studied, 6 patients had thoracic puncture and drainage of pleural effusion and 2 patients had pneumothorax puncture drainage. CONCLUSIONS: Lung ultrasound could be useful for monitoring ARDS caused by the influenza virus A H7N9 strain in clinical applications.

Structural characterization and anti-oxidative activity for a glycopeptide from Ganoderma lucidum fruiting body.

A water-soluble glycopeptide (named GL-PWQ3) with a molecular weight (Mw) of 2.40 × 104 g/mol was isolated from Ganoderma lucidum fruiting body by hot water extraction, membrane ultrafiltration, and gel column chromatography, which mainly consisted of glucose and galactose. Based on the methylation, FT-IR, 1D, and 2D NMR analysis, the polysaccharide portion of GL-PWQ3 was identified as a glucogalactan, which was comprised of unsubstituted (1,6-α-Galp, 1,6-ß-Glcp, 1,4-ß-Glcp) and monosubstituted (1,2,6-α-Galp and 1,3,6-ß-Glcp) in the backbone and possible branches that at the O-3 position of 1,3-Glcp and T-Glcp, and the O-2 position of T-Fucp, T-Manp or T-Glcp. The chain conformational study by SEC-MALLS-RI and AFM revealed that GL-PWQ3 was identified as a highly branched polysaccharide with a polydispersity index of 1.25, and might have compact sphere structures caused by stacked multiple chains. Moreover, the GL-PWQ3 shows strong anti-oxidative activity in NRK-52E cells. This study provides a theoretical basis for further elucidating the structure-functionality relationships of GL-PWQ3 and its potential application as a natural antioxidant in pharmacotherapy as well as functional food additives.

Prevalence, clinical characteristics, and long-term outcomes of new diabetes diagnosis in elderly patients undergoing percutaneous coronary intervention.

Previous studies have reported associations between newly diagnosed diabetes and poor outcomes after percutaneous coronary intervention (PCI), but there is limited data focusing on elderly patients (age ≥ 65). This study aimed to analyze the prevalence and clinical implications of newly diagnosed diabetes in elderly patients who underwent PCI. From 2004 to 2021, a total of 2456 elderly patients who underwent invasive PCI at Korea University Guro Hospital were prospectively enrolled and followed up for a median of five years. The primary endpoint was five-year major adverse cardiovascular events (MACE). Cox regression was used to evaluate whether newly diagnosed diabetes impacted on long-term clinical outcomes. Newly diagnosed diabetes was presented in approximately 8.1% to 10.9% of elderly patients who underwent PCI. Those who had a new diagnosis of diabetes had a higher risk of MACE than previously known diabetes (25.28% vs. 19.15%, p = 0.039). After adjusting for significant factors, newly diagnosed diabetes remained an independent predictor of MACE (HR [hazard ratio] 1.64, 95% confidence interval [CI] 1.24-2.17, p < 0.001), cardiac death (HR 2.15, 95% CI 1.29-3.59, p = 0.003) and repeat revascularization (HR 1.52, 95% CI 1.09-2.11, p = 0.013), but not for non-fatal myocardial infarction (HR 1.66, 95% CI 0.94-2.12, p = 0.081). Newly diagnosed diabetes was associated with an increased risk of 5-year MACE compared with non-diabetes and previously diagnosed diabetes in elderly patients underwent PCI. More attention should be given to those elderly newly diagnosed diabetes population.

Ganoderic acids alleviate atherosclerosis by inhibiting macrophage M1 polarization via TLR4/MyD88/NF-κB signaling pathway.

BACKGROUND AND AIMS: Atherosclerosis (AS) is a chronic inflammatory disease characterized by lipid infiltration and plaque formation in blood vessel walls. Ganoderic acids (GA), a class of major bioactive compounds isolated from the Chinese traditional medicine Ganoderma lucidum, have multiple pharmacological activities. This study aimed to determine the anti-atherosclerotic effect of GA and reveal the pharmacological mechanism. METHODS: ApoE-/- mice were fed a high-cholesterol diet and treated with GA for 16 weeks to induce AS and identify the effect of GA. Network pharmacological analysis was performed to predict the anti-atherosclerotic mechanisms. An invitro cell model was used to explore the effect of GA on macrophage polarization and the possible mechanism involved in bone marrow dereived macrophages (BMDMs) and RAW264.7 cells stimulated with lipopolysaccharide or oxidized low-density lipoprotein. RESULTS: It was found that GA at 5 and 25 mg/kg/d significantly inhibited the development of AS and increased plaque stability, as evidenced by decreased plaque in the aorta, reduced necrotic core size and increased collagen/lipid ratio in lesions. GA reduced the proportion of M1 macrophages in plaques, but had no effect on M2 macrophages. In vitro experiments showed that GA (1, 5, 25 µg/mL) significantly decreased the proportion of CD86+ macrophages and the mRNA levels of IL-6, IL-1ß, and MCP-1 in macrophages. Experimental results showed that GA inhibited M1 macrophage polarization by regulating TLR4/MyD88/NF-κB signaling pathway. CONCLUSIONS: This study demonstrated that GA play an important role in plaque stability and macrophage polarization. GA exert the anti-atherosclerotic effect partly by regulating TLR4/MyD88/NF-κB signaling pathways to inhibit M1 polarization of macrophages. Our study provides theoretical basis and experimental data for the pharmacological activity and mechanisms of GA against AS.

Liquiritigenin reverses skin aging by inhibiting UV-induced mitochondrial uncoupling and excessive energy consumption.

BACKGROUND: The accumulation of reactive oxygen species (ROS) generated by UV radiation can lead to lipid, protein, nucleic acid, and organelle damage, one of the core mechanisms mediating skin aging. In the photoaging process, how ROS drives the imbalance of the body's complex repair system to induce senescence-like features is not fully understood. METHODS: We irradiated human epidermal keratinocytes with 12 J/cm2 of UVA to establish an in vitro photoaging model. Then we employed whole-transcriptome sequencing and O2K mitochondrial function assay to reveal the photoprotective mechanisms of liquiritigenin (LQ). DISCUSSION: We found that skin reduces endogenous ROS by promoting mitochondrial oxidative phosphorylation uncoupling in response to UVA-induced damage. However, this also causes excessive consumption and idling of nutrients, leading to the inhibition of cell proliferation, and ultimately accelerating the skin aging process. Here, we demonstrated that LQ can reduce stress in keratinocytes, increase oxidative phosphorylation and ATP production efficiency, and block the massive loss of skin nutrients and net energy stress. Furthermore, LQ can promote collagen synthesis and keratinocyte proliferation through the PI3K-AKT pathway, thereby reversing photoaging. CONCLUSION: This work provides a new skin aging mechanism and solution strategy with high clinical translation value.

LiOtBu-Promoted trans-Stereoselective and ß-Regioselective Hydroboration of Propargyl Alcohols.

A convenient and efficient trans-stereoselective and ß-regioselective hydroboration of propargyl alcohols was achieved simply with LiOtBu as the base and (Bpin)2 as the boron reagent in dimethyl sulfoxide at room temperature. Both terminal and internal propargyl alcohols with diverse structures and functional groups underwent the transformation smoothly to produce ß-Bpin-substituted (E)-allylic alcohols, of which the synthetic potentials were demonstrated by the downstream conversions of boronate, alkenyl, and hydroxyl groups.

Nrf2 deficiency improves glucose tolerance in mice fed a high-fat diet.

Nrf2, a master regulator of intracellular redox homeostasis, is indicated to participate in fatty acid metabolism in liver. However, its role in diet-induced obesity remains controversial. In the current study, genetically engineered Nrf2-null, wild-type (WT), and Nrf2-activated, Keap1-knockdown (K1-KD) mice were fed either a control or a high-fat Western diet (HFD) for 12 weeks. The results indicate that the absence or enhancement of Nrf2 activity did not prevent diet-induced obesity, had limited effects on lipid metabolism, but affected blood glucose homeostasis. Whereas the Nrf2-null mice were resistant to HFD-induced glucose intolerance, the Nrf2-activated K1-KD mice exhibited prolonged elevation of circulating glucose during a glucose tolerance test even on the control diet. Feeding a HFD did not activate the Nrf2 signaling pathway in mouse livers. Fibroblast growth factor 21 (Fgf21) is a liver-derived anti-diabetic hormone that exerts glucose- and lipid-lowering effects. Fgf21 mRNA and protein were both elevated in livers of Nrf2-null mice, and Fgf21 protein was lower in K1-KD mice than WT mice. The inverse correlation between Nrf2 activity and hepatic expression of Fgf21 might explain the improved glucose tolerance in Nrf2-null mice. Furthermore, a more oxidative cellular environment in Nrf2-null mice could affect insulin signaling in liver. For example, mRNA of insulin-like growth factor binding protein 1, a gene repressed by insulin in hepatocytes, was markedly elevated in livers of Nrf2-null mice. In conclusion, genetic alteration of Nrf2 does not prevent diet-induced obesity in mice, but deficiency of Nrf2 improves glucose homeostasis, possibly through its effects on Fgf21 and/or insulin signaling.

Diurnal-and sex-related difference of metallothionein expression in mice.

BACKGROUND: Metallothionein (MT) is a small, cysteine-rich, metal-binding protein that plays an important role in protecting against toxicity of heavy metal and chemicals. This study was aimed to define diurnal and sex variation of MT in mice. METHODS: Adult mice were maintained in light- and temperature-controlled facilities for 2 weeks with light on at 8:00 and light off at 20:00. The blood, liver, and kidneys were collected every 4 h during the 24 h period. Total RNA was isolated, purified, and subjected to real-time RT-PCR analysis and MT protein was determined by western blot and the Cd/hemoglobin assay. RESULTS: The diurnal variations in mRNA levels of MT-1 and MT-2in liver were dramatic, up to a 40-foldpeak/trough ratio. MT mRNA levels in kidneys and blood also showed diurnal variation, up to 5-fold peak/trough ratio. The diurnal variation of MT mRNAs resembled the clock gene albumin site D-binding protein (Dbp), and was anti-phase to the clock gene Brain and Muscle ARNT-like Protein 1 (Bmal1) in liver and kidneys. The peaks of MT mRNA levels were higher in females than in males. Hepatic MT protein followed a similar pattern, with about a 3-fold difference. CONCLUSION: MT mRNA levels and protein showed diurnal- and sex-variation in liver, kidney, and blood of mice, which could impact the body defense against toxic stimuli.

Mechanism and potential treatments for gastrointestinal dysfunction in patients with COVID-19.

The global coronavirus disease 2019 (COVID-19) has become one of the biggest threats to the world since 2019. The respiratory and gastrointestinal tracts are the main targets for severe acute respiratory syndrome coronavirus 2 infection for they highly express angiotensin-converting enzyme-2 and transmembrane protease serine 2. In patients suffering from COVID-19, gastrointestinal symptoms have ranged from 12% to 61%. Anorexia, nausea and/or vomiting, diarrhea, and abdominal pain are considered to be the main gastrointestinal symptoms of COVID-19. It has been reported that the direct damage of intestinal mucosal epithelial cells, malnutrition, and intestinal flora disorders are involved in COVID-19. However, the underlying mechanisms remain unclear. Thus, in this study, we reviewed and discussed the correlated mechanisms that cause gastrointestinal symptoms in order to help to develop the treatment strategy and build an appropriate guideline for medical workers.

Simvastatin inhibits the inflammation and oxidative stress of human neutrophils in sepsis via autophagy induction.

Simvastatin exerts a protective effect during sepsis (SP) in animal models; however, the underlying mechanism is not completely understood, particularly in human SP. Neutrophils are a critical effector in the host inflammatory response to SP. Therefore, the present study aimed to investigate the effect of simvastatin on neutrophils in human SP. Neutrophils were isolated from the peripheral venous blood of adult patients with SP and healthy volunteers (HP). Cell viability was analyzed using the MTT assay. Intracellular reactive oxygen species (ROS) generation and the concentrations of inflammatory mediators were also assessed using flow cytometry and ELISA. The results demonstrated that the cell viability of neutrophils from the SP group was significantly decreased compared with that in the HP group, and that treatment with simvastatin partly reversed the reduced cell viability. Furthermore, simvastatin administration significantly decreased ROS production and the concentrations of TNF­α and IL­6, which were significantly increased in neutrophils isolated from the SP group. Simvastatin also enhanced autophagy induction, as indicated by the promotion of the conversion of LC3I to LC3II and the increased expression levels of Beclin 1 in SP neutrophils. Treatment with 3­methyladenine, an autophagy inhibitor, completely blocked the protective effects of simvastatin on neutrophils from SP, including the effects of simvastatin on the inhibition of inflammation, oxidative stress and improving cell viability. Collectively, the present study provided evidence for the simvastatin­induced autophagic process of neutrophils involved in human SP, which protects neutrophils and partially attenuates the inflammatory response and oxidative stress. Therefore, the augmentation of neutrophil autophagy may serve as a potential therapeutic target for patients with SP.

Proteomic Analyses Reveal Higher Levels of Neutrophil Activation in Men Than in Women With Systemic Lupus Erythematosus.

Objective: Systemic Lupus Erythematosus (SLE) is a systemic autoimmune disease that displays a significant gender difference in terms of incidence and severity. However, the underlying mechanisms accounting for sexual dimorphism remain unclear. The aim of this work was to reveal the heterogeneity in the pathogenesis of SLE between male and female patients. Methods: PBMC were collected from 15 patients with SLE (7 males, 8 females) and 15 age-matched healthy controls (7 males, 8 females) for proteomic analysis. The proteins of interest were validated in independent samples (6 male SLE, 6 female SLE). Biomarkers for neutrophil activation (calprotectin), neutrophil extracellular traps (cell-free DNA and elastase), and reactive oxygen species (glutathione) were measured, using enzyme-linked immunosorbent assay, in plasma obtained from 52 individuals. Results: Enrichment analysis of proteomic data revealed that type I interferon signaling and neutrophil activation networks mapped to both male and female SLE, while male SLE has a higher level of neutrophil activation compared with female SLE. Western blot validated that PGAM1, BST2, and SERPINB10 involved in neutrophil activation are more abundant in male SLE than in female SLE. Moreover, biomarkers of neutrophil activation and reactive oxygen species were increased in male SLE compared with female SLE. Conclusion: Type I interferon activation is a common signature in both male and female SLE, while neutrophil activation is more prominent in male SLE compared with female SLE. Our findings define gender heterogeneity in the pathogenesis of SLE and may facilitate the development of gender-specific treatments.

Breviscapine remodels myocardial glucose and lipid metabolism by regulating serotonin to alleviate doxorubicin-induced cardiotoxicity.

Aims: The broad-spectrum anticancer drug doxorubicin (Dox) is associated with a high incidence of cardiotoxicity, which severely affects the clinical application of the drug and patients' quality of life. Here, we assess how Dox modulates myocardial energy and contractile function and this could aid the development of relevant protective drugs. Methods: Mice were subjected to doxorubicin and breviscapine treatment. Cardiac function was analyzed by echocardiography, and Dox-mediated signaling was assessed in isolated cardiomyocytes. The dual cardio-protective and anti-tumor actions of breviscapine were assessed in mouse breast tumor models. Results: We found that Dox disrupts myocardial energy metabolism by decreasing glucose uptake and increasing fatty acid oxidation, leading to a decrease in ATP production rate, an increase in oxygen consumption rate and oxidative stress, and further energy deficits to enhance myocardial fatty acid uptake and drive DIC development. Interestingly, breviscapine increases the efficiency of ATP production and restores myocardial energy homeostasis by modulating the serotonin-glucose-myocardial PI3K/AKT loop, increasing glucose utilization by the heart and reducing lipid oxidation. It enhances mitochondrial autophagy via the PINK1/Parkin pathway, eliminates damaged mitochondrial accumulation caused by Dox, reduces the degree of cardiac fibrosis and inflammation, and restores cardiac micro-environmental homeostasis. Importantly, its low inflammation levels reduce myeloid immunosuppressive cell infiltration, and this effect is synergistic with the anti-tumor effect of Dox. Conclusion: Our findings suggest that disruption of the cardiac metabolic network by Dox is an important driver of its cardiotoxicity and that serotonin is an important regulator of myocardial glucose and lipid metabolism. Myocardial energy homeostasis and timely clearance of damaged mitochondria synergistically contribute to the prevention of anthracycline-induced cardiotoxicity and improve the efficiency of tumor treatment.

Whole-genome resequencing reveals molecular imprints of anthropogenic and natural selection in wild and domesticated sheep.

The abundance of domesticated sheep varieties and phenotypes is largely the result of long-term natural and artificial selection. However, there is limited information regarding the genetic mechanisms underlying phenotypic variation induced by the domestication and improvement of sheep. In this study, to explore genomic diversity and selective regions at the genome level, we sequenced the genomes of 100 sheep across 10 breeds and combined these results with publicly available genomic data from 225 individuals, including improved breeds, Chinese indigenous breeds, African indigenous breeds, and their Asian mouflon ancestor. Based on population structure, the domesticated sheep formed a monophyletic group, while the Chinese indigenous sheep showed a clear geographical distribution trend. Comparative genomic analysis of domestication identified several selective signatures, including IFI44 and IFI44L genes and PANK2 and RNF24 genes, associated with immune response and visual function. Population genomic analysis of improvement demonstrated that candidate genes of selected regions were mainly associated with pigmentation, energy metabolism, and growth development. Furthermore, the IFI44 and IFI44L genes showed a common selection signature in the genomes of 30 domesticated sheep breeds. The IFI44 c. 54413058 C>G mutation was selected for genotyping and population genetic validation. Results showed that the IFI44 polymorphism was significantly associated with partial immune traits. Our findings identified the population genetic basis of domesticated sheep at the whole-genome level, providing theoretical insights into the molecular mechanism underlying breed characteristics and phenotypic changes during sheep domestication and improvement.

Stereoselective Dehydroxyboration of Allylic Alcohols to Access (E)-Allylboronates by a Combination of C-OH Cleavage and Boron Transfer under Iron Catalysis.

Iron-catalyzed direct SN2' dehydroxyboration of allylic alcohols has been developed to access (E)-stereoselective allylboronates. Allylic alcohols with diverse structures and functional groups, especially derived from natural products, underwent smooth transformation. The six-membered ring transition state formed by allylic alcohols and iron-boron intermediate was indicated to be the key component involved in transfer of the boron group, activation of the C-OH bond, and control of the stereoselectivity.

Upregulated insulin receptor tyrosine kinase substrate promotes the proliferation of colorectal cancer cells via the bFGF/AKT signaling pathway.

BACKGROUND: Some recent studies on insulin receptor tyrosine kinase substrate (IRTKS) have focused more on its functions in diseases. However, there is a lack of research on the role of IRTKS in carcinomas and its mechanism remains ambiguous. In this study, we aimed to clarify the role and mechanism of IRTKS in the carcinogenesis of colorectal cancer (CRC). METHODS: We analysed the expression of IRTKS in CRC tissues and normal tissues by researching public databases. Cancer tissues and adjacent tissues of 67 CRC patients who had undergone radical resection were collected from our center. Quantitative real-time polymerase chain reaction and immunohistochemistry were performed in 52 and 15 pairs of samples, respectively. In vitro and in vivo experiments were conducted to observe the effect of IRTKS on CRC cells. Gene Set Enrichment Analysis and Metascape platforms were used for functional annotation and enrichment analysis. We detected the protein kinase B (AKT) phosphorylation and cell viability of SW480 transfected with small interfering RNAs (siRNAs) with or without basic fibroblast growth factor (bFGF) through immunoblotting and proliferation assays. RESULTS: The expression of IRTKS in CRC tissues was higher than that in adjacent tissues and normal tissues (all P < 0.05). Disease-free survival of patients with high expression was shorter. Overexpression of IRTKS significantly increased the proliferation rate of CRC cells in vitro and the number of tumor xenografts in vivo. The phosphorylation level of AKT in CRC cells transfected with pLVX-IRTKS was higher than that in the control group. Furthermore, siRNA-IRTKS significantly decreased the proliferation rate of tumor cells and the phosphorylation level of AKT induced by bFGF. CONCLUSION: IRTKS mediated the bFGF-induced cell proliferation through the phosphorylation of AKT in CRC cells, which may contribute to tumorigenicity in vivo.

A Comparison Study of Age and Colorectal Cancer-Related Gut Bacteria.

Intestinal microbiota is gaining increasing interest from researchers, and a series of studies proved that gut bacteria plays a significant role in various malignancies, especially in colorectal cancer (CRC). In this study, a cohort of 34 CRC patients (average age=65 years old), 26 young volunteers (below 30 years old), and 26 old volunteers (over 60 years old) was enrolled. 16S ribosomal RNA gene sequencing was used to explore fecal bacteria diversity. The operational taxonomic unit (OTU) clustering analysis and NMDS (non-metric multidimensional scaling) analysis were used to separate different groups. Cluster of ortholog genes (COG) functional annotation and Kyoto encyclopedia of genes and genomes (KEGG) were used to detect enriched pathways among three groups. Community separations were observed among the three groups of this cohort. Clostridia, Actinobacteria, Bifidobacterium, and Fusobacteria were the most enriched bacteria in the young group, old group, and CRC group respectively. Also, in the young, old, and CRC group, the ratio of Firmicutes/Bacteroidetes was increased sequentially despite no statistical differences. Further, COG showed that transcription, cell wall/membrane/envelope biogenesis, inorganic ion transport and metabolism, and signal transduction mechanisms were differentially expressed among three groups. KEGG pathways associated with ABC transporters, amino sugar and nucleotide sugar metabolism, arginine and proline metabolism, and aminoacyl-tRNA biosynthesis also showed statistical differences among the three groups. These results indicated that the intestinal bacterial community varied as age changed and was related to CRC, and we discussed that specific bacteria enriched in the young and old group may exert a protective function, while bacteria enriched in the CRC group may promote tumorigenesis.

Energy restriction does not compensate for the reduced expression of hepatic drug-processing genes in mice with aging.

Liver is the major organ that eliminates xenobiotics from the body, a process that is accomplished by a series of drug-processing genes (DPGs). These genes encode transporters on both basolateral and apical membranes of hepatocytes, as well as phase I and II enzymes. The current study compares the expression of hepatic DPGs in adult and aged mouse livers and explores the potential effects of energy restriction (ER) on these genes during aging. Of 79 quantified hepatic DPGs, 52 were expressed lower in 24-month-old aged mice than in 12-month-old adult mice. Furthermore, the mRNA expression of multiple xenobiotic-activated transcription factors also decreased with age. Six-month ER exerted less of an effect on the hepatic DPGs than did aging. ER increased the mRNAs of two and decreased the mRNAs of nine DPGs in adult mice. In aged mice, ER increased the mRNAs of 10 and decreased the mRNAs of 5 DPGs. The only mRNA that was increased by both ER and aging was Gstm3. ER increased the mRNAs of Cyp2b10, Ugt1a9, Gsta1, and Oatp1a4 only in adult mice and decreased the mRNAs of Aldh6a1, Pon3, Ugt1a1, Sult1a1, and Atp8b1 only in aged mice. In summary, the reduced mRNA expression of hepatic DPGs in aged mice indicates decreased drug-processing capability, whereas ER did not compensate for the global reduction of hepatic DPG expression in aged mice. The hepatic transcription factors are likely to mediate the changes in hepatic DPG expression during aging and ER.

Enhanced expression of Nrf2 in mice attenuates the fatty liver produced by a methionine- and choline-deficient diet.

Oxidative stress has been proposed as an important promoter of the progression of fatty liver diseases. The current study investigates the potential functions of the Nrf2-Keap1 signaling pathway, an important hepatic oxidative stress sensor, in a rodent fatty liver model. Mice with no (Nrf2-null), normal (wild type, WT), and enhanced (Keap1 knockdown, K1-kd) expression of Nrf2 were fed a methionine- and choline-deficient (MCD) diet or a control diet for 5 days. Compared to WT mice, the MCD diet-caused hepatosteatosis was more severe in the Nrf2-null mice and less in the K1-kd mice. The Nrf2-null mice had lower hepatic glutathione and exhibited more lipid peroxidation, whereas the K1-kd mice had the highest amount of glutathione in the liver and developed the least lipid peroxidation among the three genotypes fed the MCD diet. The Nrf2 signaling pathway was activated by the MCD diet, and the Nrf2-targeted cytoprotective genes Nqo1 and Gstalpha1/2 were induced in WT and even more in K1-kd mice. In addition, Nrf2-null mice on both control and MCD diets exhibited altered expression profiles of fatty acid metabolism genes, indicating Nrf2 may influence lipid metabolism in liver. For example, mRNA levels of long chain fatty acid translocase CD36 and the endocrine hormone Fgf21 were higher in livers of Nrf2-null mice and lower in the K1-kd mice than WT mice fed the MCD diet. Taken together, these observations indicate that Nrf2 could decelerate the onset of fatty livers caused by the MCD diet by increasing hepatic antioxidant and detoxification capabilities.

Circadian expression profiles of drug-processing genes and transcription factors in mouse liver.

Temporal coordination of hepatic drug-processing gene (DPG) expression facilitates absorption, biotransformation, and excretion of exogenous and endogenous compounds. To further elucidate the circadian rhythm of hepatic DPG expression, male C57BL/6 mice were subjected to a standard 12-h light/dark cycle, and livers were collected at 2:00, 6:00, and 10:00 AM and 2:00, 6:00, and 10:00 PM. The mRNAs of hepatic phase I enzymes (cytochromes P450, aldehyde dehydrogenases, and carboxylesterases), phase II enzymes (glucuronosyltransferases, sulfotransferases, and glutathione S-transferases), uptake and efflux transporters, and transcription factors were quantified. Messenger RNAs of various genes were graphed across time of day and compared by hierarchical clustering. In general, the mRNA of phase I enzymes increased during the dark phase, whereas the mRNAs of most phase II enzymes and transporters reached maximal levels during the light phase. The majority of hepatic transcription factors exhibited expression peaks either before or after the onset of the dark phase. During the same time period, the negative clock regulator gene Rev-Erbalpha and the hepatic clock-controlled gene Dbp also reached mRNA expression peaks. Considering their important role in xenobiotic metabolism, hepatic transcription factors, such as constitutive androstane receptor, pregnane X receptor, aryl hydrocarbon receptor, and peroxisomal proliferator activated receptor alpha, may be involved in coupling the hepatic circadian clock to environmental cues. Taken together, these data demonstrate that the circadian expression of the DPG battery and transcription factors contribute to the temporal detoxification cycle in the liver.