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(1) Background: An aging society is frequently affected by multimorbidity and polypharmacy, which, in turn, leads to an increased risk for drug interaction. The aim of this study was to evaluate the influence of drug interactions on the length of stay (LOS) in hospitals. (2) Methods: This retrospective, single-centre study is based on patients treated for community-acquired pneumonia in the hospital. Negative binomial regression was used to analyse the association between drug interactions and the LOS in the hospital. (3) Results: The total cohort contained 503 patients, yet 46 inpatients (9%) that died were not included in the analyses. The mean age was 74 (±15.3) years, 35% of patients older than 65 years were found to have more than two drug interactions, and 55% had a moderate, severe, or contraindicated adverse drug reaction. The regression model revealed a significant association between the number of drug interactions (rate ratio (RR) 1.02; 95%-CI 1.01-1.04) and the severity of drug interactions (RR 1.22; 95%-CI 1.09-1.37) on the LOS for the overall cohort as well as for the subgroup of patients aged 80 years and older. (4) Conclusion: Drug interactions are an independent risk factor for prolonged hospitalisation. Standardised assessment tools to avoid drug interactions should be implemented in clinical routines.
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BACKGROUND AND AIMS: Glycogen storage disease type I (GSD I) is associated with hyperlipidemia, a known risk factor for premature atherosclerosis. Few studies have addressed endothelial dysfunction in patients with GSD I, and these studies yielded controversial results. METHODS AND RESULTS: We investigated vascular dysfunction in a cohort of 32 patients with GSD I (26 GSD Ia, 6 GSD Ib, mean age 20.7 (4.8-47.5) years) compared to 32 age-, gender-, and BMI-matched healthy controls using non-invasive techniques such as quantification of carotid intima media thickness, retinal vessel analysis and 24 h-blood pressure measurements. In addition, early biomarkers of inflammatory and oxidative endothelial stress were assessed in blood. Although GSD I patients had a clearly proatherogenic lipid profile, increased oxidative stress, higher levels of high sensitivity C-reactive protein and increased lipoprotein associated phospholipase A2 activity, functional and structural parameters including carotid intima media thickness and retinal vessel diameters did not indicate premature atherosclerosis in this patient cohort. Blood pressure values and pulse wave velocity were comparable in patients and healthy controls, while central blood pressure and augmentation index were higher in GSD patients. CONCLUSION: Our data suggest that GSD I is not associated with early vascular dysfunction up to the age of at least 20 years. Further studies are needed to elucidate the possibly protective mechanisms that prevent early atherosclerosis is GSD I. Longer follow-up studies are required to assess the long-term risk of vascular disease with increased oxidative stress being present in GSD I patients.
Subject(s)
Glycogen Storage Disease Type I , Hyperlipidemias , Adolescent , Adult , Atherosclerosis/epidemiology , Cardiovascular Diseases/epidemiology , Case-Control Studies , Child , Child, Preschool , Cohort Studies , Female , Glycogen Storage Disease Type I/epidemiology , Humans , Hyperlipidemias/epidemiology , Male , Middle Aged , Young AdultABSTRACT
The c-Jun N-terminal kinase (JNK) signaling pathway mediates adaptation to stress signals and has been associated with cell death, cell proliferation, and malignant transformation in the liver. However, up to now, its function was experimentally studied mainly in young mice. By generating mice with combined conditional ablation of Jnk1 and Jnk2 in liver parenchymal cells (LPCs) (JNK1/2LPC-KO mice; KO, knockout), we unraveled a function of the JNK pathway in the regulation of liver homeostasis during aging. Aging JNK1/2LPC-KO mice spontaneously developed large biliary cysts that originated from the biliary cell compartment. Mechanistically, we could show that cyst formation in livers of JNK1/2LPC-KO mice was dependent on receptor-interacting protein kinase 1 (RIPK1), a known regulator of cell survival, apoptosis, and necroptosis. In line with this, we showed that RIPK1 was overexpressed in the human cyst epithelium of a subset of patients with polycystic liver disease. Collectively, these data reveal a functional interaction between JNK signaling and RIPK1 in age-related progressive cyst development. Thus, they provide a functional linkage between stress adaptation and programmed cell death (PCD) in the maintenance of liver homeostasis during aging.
Subject(s)
Aging/metabolism , Bile Duct Diseases/etiology , Bile Duct Diseases/metabolism , Caspase 8/metabolism , Cysts/etiology , Cysts/metabolism , MAP Kinase Signaling System , Receptor-Interacting Protein Serine-Threonine Kinases/genetics , Animals , Apoptosis , Biopsy , Disease Models, Animal , Disease Susceptibility , Immunohistochemistry , Immunophenotyping , Liver Diseases/etiology , Liver Diseases/metabolism , Mice , Mitogen-Activated Protein Kinase 8/deficiency , NecroptosisABSTRACT
We investigate the problem # IndSub ( Φ ) of counting all induced subgraphs of size k in a graph G that satisfy a given property Φ . This continues the work of Jerrum and Meeks who proved the problem to be # W [ 1 ] -hard for some families of properties which include (dis)connectedness [JCSS 15] and even- or oddness of the number of edges [Combinatorica 17]. Using the recent framework of graph motif parameters due to Curticapean, Dell and Marx [STOC 17], we discover that for monotone properties Φ , the problem # IndSub ( Φ ) is hard for # W [ 1 ] if the reduced Euler characteristic of the associated simplicial (graph) complex of Φ is non-zero. This observation links # IndSub ( Φ ) to Karp's famous Evasiveness Conjecture, as every graph complex with non-vanishing reduced Euler characteristic is known to be evasive. Applying tools from the "topological approach to evasiveness" which was introduced in the seminal paper of Khan, Saks and Sturtevant [FOCS 83], we prove that # IndSub ( Φ ) is # W [ 1 ] -hard for every monotone property Φ that does not hold on the Hamilton cycle as well as for some monotone properties that hold on the Hamilton cycle such as being triangle-free or not k-edge-connected for k > 2 . Moreover, we show that for those properties # IndSub ( Φ ) can not be solved in time f ( k ) · n o ( k ) for any computable function f unless the Exponential Time Hypothesis (ETH) fails. In the final part of the paper, we investigate non-monotone properties and prove that # IndSub ( Φ ) is # W [ 1 ] -hard if Φ is any non-trivial modularity constraint on the number of edges with respect to some prime q or if Φ enforces the presence of a fixed isolated subgraph.
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Background: Hepatic glycogen storage diseases (GSDs) are inborn errors of metabolism affecting the synthesis or breakdown of glycogen in the liver. This study, for the first time, systematically assessed vitamin B12 status in a large cohort of hepatic GSD patients. Methods: Plasma vitamin B12, total plasma homocysteine (tHcy) and methylmalonic acid concentrations were measured in 44 patients with hepatic GSDs and compared to 42 healthy age- and gender-matched controls. Correlations of vitamin B12 status with different disease markers of GSDs (including liver transaminase activities and triglycerides) as well as the vitamin B12 intake were studied. Results: GSD patients had significantly higher plasma vitamin B12 concentrations than healthy controls (p = 0.0002). Plasma vitamin B12 concentration remained elevated in GSD patients irrespective of vitamin B12 intake. Plasma vitamin B12 concentrations correlated negatively with triglyceride levels, whereas no correlations were detected with liver transaminase activities (GOT and GPT) in GSD patients. Merging biomarker data of healthy controls and GSD patients showed a positive correlation between vitamin B12 status and liver function, which suggests complex biomarker associations. A combined analysis of biomarkers permitted a reliable clustering of healthy controls versus GSD patients. Conclusions: Elevated plasma concentration of vitamin B12 (irrespective of B12 intake) is a common finding in patients with hepatic GSD. The negative correlation of plasma vitamin B12 with triglyceride levels suggests an influence of metabolic control on the vitamin B12 status of GSD patients. Elevated vitamin B12 was not correlated with GOT and GPT in our cohort of GSD patients. Merging of data from healthy controls and GSD patients yielded positive correlations between these biomarkers. This apparent dichotomy highlights the intrinsic complexity of biomarker associations and argues against generalizations of liver disease and elevated vitamin B12 in blood. Further studies are needed to determine whether the identified associations are causal or coincidental, and the possible impact of chronically elevated vitamin B12 on GSD.
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Nonalcoholic steatohepatitis (NASH), a primary cause of liver disease, leads to complications such as fibrosis, cirrhosis, and carcinoma, but the pathophysiology of NASH is incompletely understood. Epstein-Barr virus-induced G protein-coupled receptor 2 (EBI2) and its oxysterol ligand 7α,25-dihydroxycholesterol (7α,25-diHC) are recently discovered immune regulators. Several lines of evidence suggest a role of oxysterols in NASH pathogenesis, but rigorous testing has not been performed. We measured oxysterol levels in the livers of NASH patients by LC-MS and tested the role of the EBI2-7α,25-diHC system in a murine feeding model of NASH. Free oxysterol profiling in livers from NASH patients revealed a pronounced increase in 24- and 7-hydroxylated oxysterols in NASH compared with controls. Levels of 24- and 7-hydroxylated oxysterols correlated with histological NASH activity. Histological analysis of murine liver samples demonstrated ballooning and liver inflammation. No significant genotype-related differences were observed in Ebi2-/- mice and mice with defects in the 7α,25-diHC synthesizing enzymes CH25H and CYP7B1 compared with wild-type littermate controls, arguing against an essential role of these genes in NASH pathogenesis. Elevated 24- and 7-hydroxylated oxysterol levels were confirmed in murine NASH liver samples. Our results suggest increased bile acid synthesis in NASH samples, as judged by the enhanced level of 7α-hydroxycholest-4-en-3-one and impaired 24S-hydroxycholesterol metabolism as characteristic biochemical changes in livers affected by NASH.
Subject(s)
Liver/metabolism , Liver/pathology , Non-alcoholic Fatty Liver Disease/metabolism , Non-alcoholic Fatty Liver Disease/pathology , Oxysterols/metabolism , Adult , Alanine Transaminase/blood , Animals , Aspartate Aminotransferases/blood , Cholesterol/blood , Chromatography, Liquid , Flow Cytometry , Humans , Hydroxycholesterols/blood , Hydroxycholesterols/metabolism , Male , Mass Spectrometry , Mice , Mice, Knockout , Middle Aged , Mixed Function Oxygenases/genetics , Mixed Function Oxygenases/metabolism , Non-alcoholic Fatty Liver Disease/blood , Oxysterols/blood , Steroid Hydroxylases/genetics , Steroid Hydroxylases/metabolismABSTRACT
OBJECTIVE: Hypovitaminosis D is common in the obese population and patients suffering from obesity-associated disorders such as type 2 diabetes and fatty liver disease, resulting in suggestions for vitamin D supplementation as a potential therapeutic option. However, the pathomechanistic contribution of the vitamin D-vitamin D receptor (VDR) axis to metabolic disorders is largely unknown. METHODS: We analyzed the pathophysiological role of global and intestinal VDR signaling in diet-induced obesity (DIO) using global Vdr-/- mice and mice re-expressing an intestine-specific human VDR transgene in the Vdr deficient background (Vdr-/- hTg). RESULTS: Vdr-/- mice were protected from DIO, hepatosteatosis and metabolic inflammation in adipose tissue and liver. Furthermore, Vdr-/- mice displayed a decreased adipose tissue lipoprotein lipase (LPL) activity and a reduced capacity to harvest triglycerides from the circulation. Intriguingly, all these phenotypes were partially reversed in Vdr-/- hTg animals. This clearly suggested an intestine-based VDR activity on systemic lipid homeostasis. Scrutinizing this hypothesis, we identified the potent LPL inhibitor angiopoietin-like 4 (Angptl4) as a novel transcriptional target of VDR. CONCLUSION: Our study suggests a VDR-mediated metabolic cross-talk between gut and adipose tissue, which significantly contributes to systemic lipid homeostasis. These results have important implications for use of the intestinal VDR as a therapeutic target for obesity and associated disorders.
Subject(s)
Angiopoietin-Like Protein 4/genetics , Fatty Liver/genetics , Intestinal Mucosa/metabolism , Lipoprotein Lipase/genetics , Liver/metabolism , Receptors, Calcitriol/genetics , Adipose Tissue/metabolism , Adipose Tissue/pathology , Adult , Aged , Angiopoietin-Like Protein 4/metabolism , Animals , Cohort Studies , Fatty Liver/metabolism , Fatty Liver/pathology , Female , Gene Expression Regulation , Humans , Inflammation , Intestinal Mucosa/pathology , Lipid Metabolism/genetics , Lipoprotein Lipase/antagonists & inhibitors , Lipoprotein Lipase/metabolism , Liver/pathology , Male , Mice , Mice, Obese , Mice, Transgenic , Middle Aged , Receptors, Calcitriol/deficiency , Signal Transduction , Transcription, Genetic , Transgenes , Triglycerides/metabolismABSTRACT
BACKGROUND & AIMS: Serum interferon-gamma-inducible protein-10 (IP-10) is elevated in cholestatic liver diseases and predicts response to antiviral therapy in patients with chronic hepatitis C virus (HCV) infection. Dipeptidylpeptidase 4 (DPPIV) cleaves active IP-10 into an inactive form, which inhibits recruitment of CXCR3+ T cells to the liver. In this study the link between IP-10 levels, DPPIV activity in serum and CXCR3+ T cells is analysed in cholestatic and non-cholestatic liver patients. METHODS: In serum DPPIV activity (by enzymatic assay), IP-10 (by ELISA) and bile acids (BA) (by enzymatic assay) were analysed in 229 naive HCV genotype (GT) 1 patients and in 16 patients with cholestatic liver disease. In a prospective follow-up (FU) cohort of 27 HCV GT 1 patients peripheral CD3+CXCR3+, CD4+CXCR3+ and CD8+CXCR3+ cells were measured by FACS. RESULTS: In 229 HCV patients serum IP-10 levels correlated positively to DPPIV serum activity. Higher IP-10 levels and DPPIV activity were detected in cholestatic and in cirrhotic HCV patients. Increased IP-10 serum levels were associated with therapeutic non-response to antiviral treatment with pegylated-interferon and ribavirin. In the HCV FU cohort elevated IP-10 serum levels and increased BA were associated with higher frequencies of peripheral CD3+CXCR3+, CD4+CXCR3+ and CD8+CXCR3+ T cells. Positive correlation between serum IP-10 levels and DPPIV activity was likewise validated in patients with cholestatic liver diseases. CONCLUSIONS: A strong correlation between elevated serum levels of IP-10 and DPPIV activity was seen in different cholestatic patient groups. Furthermore, in cholestatic HCV patients a functional link to increased numbers of peripheral CXCR3+ immune cells could be observed. The source of DPPIV release in cholestatic patients remains open.
Subject(s)
Chemokine CXCL10/blood , Cholestasis/blood , Dipeptidyl Peptidase 4/blood , Hepatitis C/blood , Receptors, CXCR3/metabolism , T-Lymphocytes/metabolism , Bile Acids and Salts/blood , CD3 Complex/metabolism , CD4 Antigens/metabolism , Cholestasis/metabolism , Enzyme-Linked Immunosorbent Assay , Female , Flow Cytometry , Hepatitis C/metabolism , Humans , Leukocytes, Mononuclear/metabolism , MaleABSTRACT
Type 2 diabetes (T2DM) and obesity are frequently associated with non-alcoholic fatty liver disease (NAFLD) and with an elevated cancer incidence. The molecular mechanisms of carcinogenesis in this context are only partially understood. High blood insulin levels are typical in early T2DM and excessive insulin can cause elevated reactive oxygen species (ROS) production and genomic instability. ROS are important for various cellular functions in signaling and host defense. However, elevated ROS formation is thought to be involved in cancer induction. In the molecular events from insulin receptor binding to genomic damage, some signaling steps have been identified, pointing at the PI3K/AKT pathway. For further elucidation Phosphatase and Tensin homolog (Pten), a tumour suppressor phosphatase that plays a role in insulin signaling by negative regulation of PI3K/AKT and its downstream targets, was investigated here. Dihydroethidium (DHE) staining was used to detect ROS formation in immortalized human hepatocytes. Comet assay and micronucleus test were performed to investigate genomic damage in vitro. In liver samples, DHE staining and western blot detection of HSP70 and HO-1 were performed to evaluate oxidative stress response. DNA double strand breaks (DSBs) were detected by immunohistostaining. Inhibition of PTEN with the pharmacologic inhibitor VO-OHpic resulted in increased ROS production and genomic damage in a liver cell line. Knockdown of Pten in a mouse model yielded increased oxidative stress levels, detected by ROS levels and expression of the two stress-proteins HSP70 and HO-1 and elevated genomic damage in the liver, which was significant in mice fed with a high fat diet. We conclude that PTEN is involved in oxidative stress and genomic damage induction in vitro and that this may also explain the in vivo observations. This further supports the hypothesis that the PI3K/AKT pathway is responsible for damaging effects of high levels of insulin.
Subject(s)
DNA Damage , Hepatocytes/pathology , Liver/pathology , Oxidative Stress , PTEN Phosphohydrolase/physiology , Animals , Cells, Cultured , Comet Assay , Hepatocytes/metabolism , Humans , Liver/metabolism , Mice , Mice, Inbred C57BL , Mice, Knockout , Reactive Oxygen Species/metabolism , Signal TransductionABSTRACT
BACKGROUND: Fibroblast growth factor (FGF) 15/19 is part of the gut-liver crosstalk accounting for bile acid (BA) metabolism regulation. Dysregulation of fibroblast growth factor 15/19 signaling is observed in different pathological conditions, for example, in gastrointestinal diseases such as inflammatory bowel disease (IBD). To understand the molecular bases, we analyzed the enterohepatic regulation of Fgf15-mediated pathway in 2 different inflammatory bowel disease mouse models. METHODS: Target genes of the BA-farnesoid-X-receptor (Fxr)-Ffg15 axis were quantified by RT-PCR or western blotting in gut and liver of dextran sulfate sodium (DSS)-treated and IL10 mice. Serum Fgf15 levels were analyzed by ELISA. Biliary and fecal BA composition was differentiated by HPLC-MS/MS. RESULTS: Dextran sulfate sodium-treated mice with ileum-sparing colitis showed higher Fgf15 serum levels. In contrast, IL10 mice with ileitis had a trend toward decreased Fgf15 serum levels compared with controls and increased expression of Asbt as a negative Fxr-target gene. In hepatic tissue of both models, no histological changes, but higher interleukin 6 (IL-6) mRNA expression and down-regulation of Fxr and Cytochrom P450 7a1 mRNA expression were observed. Fibroblast growth factor receptor 4 up-regulation was in line with higher Fgf15 serum levels in dextran sulfate sodium-treated mice. A distinct fecal BA profile was observed in both models with significantly higher levels of taurine-conjugated BA in particular tauro-ß-muricholic acid in IL10 mice. CONCLUSIONS: Ileum-sparing colitis is characterized by activation of Fxr-Fgf15 signaling with higher expression of Fxr-target gene Fgf15, whereas ileal inflammation showed no signs of Fxr-Fgf15 activation. Abundance of BA such as T-ß-MCA may be important for intestinal Fxr activation in mice.
Subject(s)
Bile Acids and Salts/metabolism , Colitis/metabolism , Fibroblast Growth Factors/metabolism , Receptors, Cytoplasmic and Nuclear/metabolism , Signal Transduction/physiology , Animals , Colitis/chemically induced , Colitis/pathology , Colitis/physiopathology , Cytochrome P-450 Enzyme System , Dextran Sulfate , Disease Models, Animal , Down-Regulation , Female , Fibroblast Growth Factors/blood , Ileum/physiopathology , Intestines/physiopathology , Liver/metabolism , Mice , Mice, Inbred C57BL , Real-Time Polymerase Chain Reaction , Receptor, Fibroblast Growth Factor, Type 4/metabolism , Up-RegulationABSTRACT
Fibroblast growth factor 19 (FGF19) is a gut-derived hormone that controls bile acid (BA), carbohydrate and lipid metabolism. Whereas strong evidence supports a key role of BAs and farnesoid X receptor (FXR) for the control of FGF19 expression, information on other regulators is limited. In mice, FGF15 expression (ortholog of human FGF19) is induced by vitamin A (VitA) in an FXR-dependent manner. However, the significance of this finding for human FGF19 is currently unclear. Here, we demonstrate that VitA derivatives induce FGF19 in human intestinal cell lines by a direct transcriptional mechanism. In contrast to mouse FGF15, however, this direct regulation is not dependent on FXR but mediated by retinoic acid receptors (RARs) and their interaction with a novel DR-5 element in the human FGF19 gene. In addition to this direct effect, VitA derivatives impacted on the BA-mediated control of FGF19 by regulation of FXR protein levels. In conclusion, VitA regulates human FGF19 expression through FXR-dependent and -independent pathways. Moreover, we suggest that considerable mechanistic differences exist between humans and mice with regard to the nuclear receptors controlling the VitA-FGF15/19 axis. These findings may implicate a clinical relevance of RAR-activating VitA derivatives for the regulation of FGF19 levels in humans.
Subject(s)
Fibroblast Growth Factors/genetics , Receptors, Cytoplasmic and Nuclear/genetics , Transcription, Genetic , Vitamin A/metabolism , Animals , Bile Acids and Salts/genetics , Bile Acids and Salts/metabolism , Cell Line , Fibroblast Growth Factors/biosynthesis , Gene Expression Regulation , Humans , Intestinal Mucosa/metabolism , Intestines/cytology , Lipid Metabolism/genetics , Mice , Receptors, Cytoplasmic and Nuclear/metabolism , Receptors, Retinoic Acid/genetics , Receptors, Retinoic Acid/metabolism , Signal Transduction , Vitamin A/analogs & derivatives , Vitamin A/geneticsABSTRACT
OBJECTIVES: Liver biopsies are the current gold standard in non-alcoholic steatohepatitis (NASH) diagnosis. Their invasive nature, however, still carries an increased risk for patients' health. The development of non-invasive diagnostic tools to differentiate between bland steatosis (NAFL) and NASH remains crucial. The aim of this study is the evaluation of investigated circulating microRNAs in combination with new targets in order to optimize the discrimination of NASH patients by non-invasive serum biomarkers. METHODS: Serum profiles of four microRNAs were evaluated in two cohorts consisting of 137 NAFLD patients and 61 healthy controls. In a binary logistic regression model microRNAs of relevance were detected. Correlation of microRNA appearance with known biomarkers like ALT and CK18-Asp396 was evaluated. A simplified scoring model was developed, combining the levels of microRNA in circulation and CK18-Asp396 fragments. Receiver operating characteristics were used to evaluate the potential of discriminating NASH. RESULTS: The new finding of our study is the different profile of circulating miR-21 in NASH patients (p<0.0001). Also, it validates recently published results of miR-122 and miR-192 to be differentially regulated in NAFL and NASH. Combined microRNA expression profiles with CK18-Asp396 fragment level scoring model had a higher potential of NASH prediction compared to other risk biomarkers (AUROC = 0.83, 95% CI = 0.754-0.908; p<0.001). Evaluation of score model for NAFL (Score = 0) and NASH (Score = 4) had shown high rates of sensitivity (91%) and specificity (83%). CONCLUSIONS: Our study defines candidates for a combined model of miRNAs and CK18-Asp396 levels relevant as a promising expansion for diagnosis and in turn treatment of NASH.
Subject(s)
Biomarkers/blood , Liver/pathology , MicroRNAs/blood , Non-alcoholic Fatty Liver Disease/blood , Adult , Apoptosis , Biopsy , Case-Control Studies , Cohort Studies , Female , Gene Expression Profiling , Humans , Male , Non-alcoholic Fatty Liver Disease/diagnosis , Obesity/blood , ROC Curve , Regression Analysis , Sensitivity and Specificity , Young AdultABSTRACT
BACKGROUND & AIMS: There is a growing evidence that bile acids are involved in the regulation of triglyceride-, cholesterol-homoeostasis and fat absorption. In this study organ-specific Fxr knockout mice were used to further investigate the influence of farnesoid X receptor FXR in lipogenesis. METHODS: Liver- and intestine-specific Fxr knockout mice were fed a 1% cholesterol diet for 28 days. Histological examination of frozen tissue sections included Sudan III/H&E, BODIPY staining and liver X receptor (LXR) immunohistochemistry. Liver triglycerides, serum cholesterol, serum bile acids and nuclear LXR protein were measured. mRNA expression of several genes involved in bile acid-, cholesterol-homoeostasis and lipogenesis was quantified by real-time PCR. RESULTS: Hepatic FXR deficiency contributes to lipid accumulation under 1% cholesterol administration which is not observed in intestinal Fxr knockout mice. Strong lipid accumulation, characterized by larger vacuoles could be observed in hepatic Fxr knockout sections, while intestinal Fxr knockout mice show no histological difference to controls. In addition, these mice have the ability to maintain normal serum cholesterol and bile acid levels. Hepatic Fxr knockouts were characterized by elevated triglycerides and bile acid levels. Expression level of LXR was significantly elevated under control and 1% cholesterol diet in hepatic Fxr knockout mice and was followed by concomitant lipogenic target gene induction such as Fas and Scd-1. This protective FXR effect against hepatic lipid accumulation was independent of intestinal Fgf15 induction. CONCLUSION: These results show that the principal site of protective bile acid signalling against lipid accumulation is located in the liver since the absence of hepatic but not intestinal FXR contributes to lipid accumulation under cholesterol diet.
Subject(s)
Fibroblast Growth Factors/metabolism , Intestinal Mucosa/metabolism , Liver/metabolism , Non-alcoholic Fatty Liver Disease/prevention & control , Receptors, Cytoplasmic and Nuclear/metabolism , Signal Transduction , Animals , Bile Acids and Salts/blood , Cholesterol, Dietary , Disease Models, Animal , Gene Expression Regulation , Liver/pathology , Liver X Receptors , Male , Mice, Inbred C57BL , Mice, Knockout , Non-alcoholic Fatty Liver Disease/genetics , Non-alcoholic Fatty Liver Disease/metabolism , Non-alcoholic Fatty Liver Disease/pathology , Orphan Nuclear Receptors/genetics , Orphan Nuclear Receptors/metabolism , Receptors, Cytoplasmic and Nuclear/deficiency , Receptors, Cytoplasmic and Nuclear/genetics , Stearoyl-CoA Desaturase/genetics , Stearoyl-CoA Desaturase/metabolism , Triglycerides/blood , fas Receptor/genetics , fas Receptor/metabolismABSTRACT
LINC complexes are evolutionarily conserved nuclear envelope bridges, composed of SUN (Sad-1/UNC-84) and KASH (Klarsicht/ANC-1/Syne/homology) domain proteins. They are crucial for nuclear positioning and nuclear shape determination, and also mediate nuclear envelope (NE) attachment of meiotic telomeres, essential for driving homolog synapsis and recombination. In mice, SUN1 and SUN2 are the only SUN domain proteins expressed during meiosis, sharing their localization with meiosis-specific KASH5. Recent studies have shown that loss of SUN1 severely interferes with meiotic processes. Absence of SUN1 provokes defective telomere attachment and causes infertility. Here, we report that meiotic telomere attachment is not entirely lost in mice deficient for SUN1, but numerous telomeres are still attached to the NE through SUN2/KASH5-LINC complexes. In Sun1(-/-) meiocytes attached telomeres retained the capacity to form bouquet-like clusters. Furthermore, we could detect significant numbers of late meiotic recombination events in Sun1(-/-) mice. Together, this indicates that even in the absence of SUN1 telomere attachment and their movement within the nuclear envelope per se can be functional.
Subject(s)
Meiosis/genetics , Membrane Proteins/genetics , Microtubule-Associated Proteins/genetics , RNA, Long Noncoding/genetics , Telomere-Binding Proteins/genetics , Animals , Cell Cycle Proteins/genetics , Cytoskeletal Proteins , Mice , Multiprotein Complexes/genetics , Nuclear Envelope/genetics , Nuclear Proteins/genetics , Telomere/geneticsABSTRACT
BACKGROUND & AIMS: Age is frequently discussed as negative host factor to achieve a sustained virological response (SVR) to antiviral therapy of chronic hepatitis C. However, elderly patients often show advanced fibrosis/cirrhosis as known negative predictive factor. The aim of this study was to assess age as an independent predictive factor during antiviral therapy. METHODS: Overall, 516 hepatitis C patients were treated with pegylated interferon-α and ribavirin, thereof 66 patients ≥60 years. We analysed the impact of host factors (age, gender, fibrosis, haemoglobin, previous hepatitis C treatment) and viral factors (genotype, viral load) on SVR per therapy course by performing a generalized estimating equations (GEE) regression modelling, a matched pair analysis and a classification tree analysis. RESULTS: Overall, SVR per therapy course was 42.9 and 26.1%, respectively, in young and elderly patients with hepatitis C virus (HCV) genotypes 1/4/6. The corresponding figures for HCV genotypes 2/3 were 74.4 and 84%. In the GEE model, age had no significant influence on achieving SVR. In matched pair analysis, SVR was not different in young and elderly patients (54.2 and 55.9% respectively; P = 0.795 in binominal test). In classification tree analysis, age was not a relevant splitting variable. CONCLUSIONS: Age is not a significant predictive factor for achieving SVR, when relevant confounders are taken into account. As life expectancy in Western Europe at age 60 is more than 20 years, it is reasonable to treat chronic hepatitis C in selected elderly patients with relevant fibrosis or cirrhosis but without major concomitant diseases, as SVR improves survival and reduces carcinogenesis.
Subject(s)
Hepacivirus/genetics , Hepatitis C, Chronic/drug therapy , Hepatitis C, Chronic/pathology , Interferon-alpha/therapeutic use , Polyethylene Glycols/therapeutic use , Ribavirin/therapeutic use , Age Factors , Aged , Genotype , Hemoglobins/metabolism , Hepacivirus/drug effects , Humans , Interferon-alpha/pharmacology , Matched-Pair Analysis , Polyethylene Glycols/pharmacology , Recombinant Proteins/pharmacology , Recombinant Proteins/therapeutic use , Regression Analysis , Ribavirin/pharmacology , Sex Factors , Treatment Outcome , Viral LoadABSTRACT
RFA (radiofrequency ablation) is an established therapy for HCC (hepatocellular carcinoma). The multikinase inhibitor sorafenib prolongs survival in advanced HCC. We examined the effects of RFA alone and in combination with sorafenib on a bystanding tumour in a two-tumour rat model of HCC. A total of 80 rats were implanted with two liver tumours and randomized to four treatment groups: vehicle and sham operation (control), sorafenib and sham operation (Sora/Sham), vehicle and RFA (Vh/RFA), and sorafenib and RFA (Sora/RFA) (n=10/group per time point). RFA or sham-operation was performed on the left lobe tumour on day 15. Animals were killed at day 18 and day 30. Non-RFA-targeted right lobe tumours were analysed for angiogenesis, growth factors [HGF (hepatocyte growth factor), EGF (epidermal growth factor) and VEGF (vascular endothelial growth factor)] and infiltrating immune cells (CD3 and CD68). At day 30, the non-RFA-targeted tumours were significantly smaller in all three treatment groups compared with control (Sora/Sham P≤0.0001, Vh/RFA P=0.005 and Sora/RFA P≤0.0001). The smallest tumours were observed in animals treated with a combination of sorafenib and RFA, whereas the size reduction seen in the RFA-only group indicated an RFA-mediated distant suppression of tumour growth. Growth factor measurement revealed transiently decreased EGF levels after RFA (P=0.008), whereas sorafenib treatment decreased HGF levels (P=0.001). MVD (microvessel density) was reduced by sorafenib (P=0.002) despite increased VEGF levels (P≤0.0001). The immune parameters revealed augmented T-cells and IL-10 (interleukin 10) levels in all three treatment groups; sorafenib additionally increased macrophage numbers (P≤0.0001). RFA and sorafenib alone resulted in significant volume reduction of the non-RFA-targeted tumour; this effect was enhanced when both modalities were combined.
Subject(s)
Antineoplastic Agents/therapeutic use , Carcinoma, Hepatocellular/surgery , Catheter Ablation , Liver Neoplasms, Experimental/surgery , Niacinamide/analogs & derivatives , Phenylurea Compounds/therapeutic use , Animals , Antineoplastic Agents/pharmacology , Carcinoma, Hepatocellular/blood supply , Carcinoma, Hepatocellular/drug therapy , Carcinoma, Hepatocellular/metabolism , Cell Line, Tumor , Cell Proliferation/drug effects , Epidermal Growth Factor/metabolism , Hepatocyte Growth Factor/metabolism , Interleukin-10/metabolism , Liver Neoplasms, Experimental/blood supply , Liver Neoplasms, Experimental/drug therapy , Liver Neoplasms, Experimental/metabolism , Macrophages/drug effects , Niacinamide/pharmacology , Niacinamide/therapeutic use , Phenylurea Compounds/pharmacology , Rats , Sorafenib , T-Lymphocytes/drug effects , Transforming Growth Factor beta/metabolism , Vascular Endothelial Growth Factors/metabolismABSTRACT
UNLABELLED: Human iron homeostasis is regulated by intestinal iron transport, hepatic hepcidin release, and signals from pathways that consume or supply iron. The aim of this study was to characterize the adaptation of iron homeostasis under hypoxia in mountaineers at the levels of (1) hepatic hepcidin release, (2) intestinal iron transport, and (3) systemic inflammatory and erythropoietic responses. Twenty-five healthy mountaineers were studied. Blood samples and duodenal biopsies were taken at baseline of 446 m as well as on day 2 (MG2) and 4 (MG4) after rapid ascent to 4559 m. Divalent metal-ion transporter 1 (DMT-1), ferroportin 1 (FP-1) messenger RNA (mRNA), and protein expression were analyzed in biopsy specimens by quantitative reverse-transcription polymerase chain reaction (RT-PCR) and immunohistochemistry. Serum hepcidin levels were analyzed by mass spectrometry. Serum iron, ferritin, transferrin, interleukin (IL)-6, and C-reactive protein (CRP) were quantified by standard techniques. Serum erythropoietin and growth differentiation factor 15 (GDF15) levels were measured by enzyme-linked immunosorbent assay (ELISA). Under hypoxia, erythropoietin peaked at MG2 (P < 0.001) paralleled by increased GDF15 on MG2 (P < 0.001). Serum iron and ferritin levels declined rapidly on MG2 and MG4 (P < 0.001). Duodenal DMT-1 and FP-1 mRNA expression increased up to 10-fold from baseline on MG2 and MG4 (P < 0.001). Plasma CRP increased on MG2 and MG4, while IL-6 only increased on MG2 (P < 0.001). Serum hepcidin levels decreased at high altitude on MG2 and MG4 (P < 0.001). CONCLUSION: This study in healthy volunteers showed that under hypoxemic conditions hepcidin is repressed and duodenal iron transport is rapidly up-regulated. These changes may increase dietary iron uptake and allow release of stored iron to ensure a sufficient iron supply for hypoxia-induced compensatory erythropoiesis.
Subject(s)
Adaptation, Physiological , Altitude , Hypoxia/metabolism , Iron/metabolism , Adult , Altitude Sickness/drug therapy , Basic Helix-Loop-Helix Transcription Factors/biosynthesis , C-Reactive Protein/metabolism , Cation Transport Proteins/blood , Dexamethasone/therapeutic use , Duodenum/metabolism , Female , Ferritins/blood , Growth Differentiation Factor 15/blood , Hepcidins/blood , Humans , Interleukin-6/blood , Liver , Male , Middle Aged , RNA, Messenger/metabolism , Transferrin/metabolismABSTRACT
OBJECTIVE: The aim of this clinical study was to evaluate whether a correlation exists between three-dimensional tooth mobility (TM) and Periotest values for maxillary anterior periodontally involved teeth (pocket depth > 3 mm) before and after periodontal therapy. METHOD AND MATERIALS: Force-related TM was measured in 3 N intervals in 19 participants as they bit down on a load cell. Periotest values were evaluated at reproducible measurement points. Both measurement techniques were performed on maxillary central and lateral incisors and canine teeth before periodontal treatment and after a healing period of 3 months. The Pearson product-moment correlation coefficient was calculated to determine exploratory associations. RESULTS: The comparison between TM and Periotest values indicated "high" and "optimum" correlations for maxillary central incisors before and after periodontal therapy. Lateral incisors exhibited "moderate" and "high" correlations, whereas canines exhibited "weak" and "moderate" correlations before and after periodontal therapy. CONCLUSION: Periotest values may provide valuable information about quantitative metric tooth mobility in periodontally involved teeth. In future investigations, the study design can expand on various dental fields, such as implantology and traumatology.
Subject(s)
Aggressive Periodontitis , Chronic Periodontitis , Tooth Mobility/diagnosis , Adult , Aged , Aggressive Periodontitis/complications , Aggressive Periodontitis/therapy , Anti-Infective Agents, Local/therapeutic use , Bite Force , Chlorhexidine/therapeutic use , Chronic Periodontitis/complications , Chronic Periodontitis/therapy , Cuspid , Dental Scaling , Female , Humans , Incisor , Middle Aged , Tooth Mobility/complicationsABSTRACT
The nuclear lamina is the structural scaffold of the nuclear envelope and is well known for its central role in nuclear organization and maintaining nuclear stability and shape. In the past, a number of severe human disorders have been identified to be associated with mutations in lamins. Extensive research on this topic has provided novel important clues about nuclear lamina function. These studies have contributed to the knowledge that the lamina constitutes a complex multifunctional platform combining both structural and regulatory functions. Here, we report that, in addition to the previously demonstrated significance for somatic cell differentiation and maintenance, the nuclear lamina is also an essential determinant for germ cell development. Both male and female mice lacking the short meiosis-specific A-type lamin C2 have a severely defective meiosis, which at least in the male results in infertility. Detailed analysis revealed that lamin C2 is required for telomere-driven dynamic repositioning of meiotic chromosomes. Loss of lamin C2 affects precise synapsis of the homologs and interferes with meiotic double-strand break repair. Taken together, our data explain how the nuclear lamina contributes to meiotic chromosome behaviour and accurate genome haploidization on a mechanistic level.
Subject(s)
Germ Cells , Homologous Recombination/genetics , Laminin , Meiosis/genetics , Nuclear Lamina , Animals , Cell Differentiation , Chromosomes/genetics , Female , Germ Cells/growth & development , Germ Cells/metabolism , Humans , Infertility, Male/etiology , Infertility, Male/genetics , Infertility, Male/metabolism , Laminin/genetics , Laminin/metabolism , Male , Mice , Mutation , Nuclear Lamina/genetics , Nuclear Lamina/metabolismABSTRACT
UNLABELLED: Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease in industrialized countries and may proceed to steatohepatitis (NASH). Apoptosis and free fatty acid (FFA)-induced lipotoxicity are important features of NASH pathogenesis. We have shown a hepatoprotective effect of adiponectin in steatotic livers of hepatitis C virus (HCV) patients and recent data links bile acid (BA) metabolism to the pathogenesis of NAFLD. The aim of this study was to identify potential interactions between BA and FFA metabolism in NAFLD. Liver biopsies and serum samples from 113 morbidly obese patients receiving bariatric surgery, healthy individuals, and moderately obese NAFLD patients were studied. Serum FFA, BA, and M30 were increased in NASH versus simple steatosis, while adiponectin was significantly decreased. The NAFLD activity score (NAS) score correlated with BA levels and reversely with adiponectin. Adiponectin reversely correlated with CD95/Fas messenger RNA (mRNA) and hepatocellular apoptosis. The BA transporter high-affinity Na+ /taurocholate cotransporter (NTCP) and the BA synthesizing enzyme cholesterol 7 alpha-hydroxylase (CYP7A1) were significantly up-regulated in obese patients and hepatoma cells exposed to FFA. Up-regulation of NTCP and CYP7A1 indicate failure to activate small heterodimer partner (SHP) upon farnesoid X receptor (FXR) stimulation by increasing BA concentrations. In line with the NAS score, adiponectin levels were reversely correlated with BA levels. Adiponectin correlated with NTCP and affects Cyp7A1 expression both in vivo and in vitro. CONCLUSION: BA synthesis and serum BA levels correlated with disease severity in NAFLD, while adiponectin is reversely correlated. FFA exposure prevented SHP-mediated repression of NTCP and Cyp7A1 expression, which lead to increased BA synthesis and uptake. In NASH, BA accumulation induced hepatocyte cell death and late FXR activation failed to prevent hepatocyte injury due to decreased adiponectin levels. Early treatment with FXR ligands and/or adiponectin-receptor agonists might prevent NASH.