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Detrimental consequences of antibiotic treatment may include long-lasting disruption of the gut microbiota. Previous studies found no negative effects of antibiotics on metabolic health, although individualized responses were observed. Here, we aimed to investigate the subject-specific response to vancomycin use in tissue-specific insulin sensitivity by stratifying individuals based on the presence of antibiotic resistance genes (ARGs) or opportunistic pathogens (OPs) in the baseline fecal microbiota. Quantitative Polymerase Chain Reaction (qPCR) was used to detect ARGs and OPs in DNA isolated from fecal samples of 56 males with overweight/obesity (Body Mass Index: 25-35 kg/m

A growing body of evidence suggests that the human gut microbiota plays a role in the development of obesity and related metabolic diseases. However, there is little consensus between studies, which could be due to biological as well as technical variation. In addition, little human data are available to investigate whether tissue-specific insulin sensitivity is related to specific microbial patterns. We examined this relation in two independent cohorts of overweight and obese pre-diabetic men, using phylogenetic microarray data and hepatic, peripheral and adipose tissue insulin sensitivity that were determined by a two-step hyperinsulinemic-euglycemic clamp with [6,6-2H2]-glucose tracer infusion. Despite a prominent subject-specific microbiota, we found significant associations of microbial taxa with tissue-specific insulin sensitivity using regression analysis. Using random forests we found moderate associations with other measures of glucose homeostasis in only one of the cohorts (fasting glucose concentrations AUC = 0.66 and HbA1c AUC = 0.65). However, all findings were cohort-specific due to pronounced variation in microbiota between cohorts, suggesting the existence of alternative states for dysbiosis in metabolic syndrome patients. Our findings suggest individual or group related dynamics, instead of universal microbiota signals, related to the host when the overweight or obese state has already developed and argue that care should be taken with extrapolating significant correlations from single cohorts, into generalized biological relevance.

Background Measures during the COVID-19 pandemic, including the closure of schools and sports facilities, may have lasting impact on the physical activity (PA) of children that persists for a long time. Objective To investigate the effect of COVID-19 measures on screen time and PA in Dutch children pre-, during- and post-school closures. Methods In cohort A (n = 102, 10.5 ± 3.6 years, 42.4% boys), data on PA and screen time during the lockdown were collected using a questionnaire. In cohort B (n = 131, 10.2 ± 0.9 years, 43.5% boys), data on PA and screen time were collected using a questionnaire and accelerometry 1 year before and after school closure. Results In cohort A, 62% reported less total PA. Self-reported screen time on week days increased 34 ± 105 min/d during the lockdown. In cohort B, sedentary time as measured by accelerometry, increased by 45 ± 67 min/d and only 20% reached PA levels of 60 min/d compared to 64% in May 2019. Self-reported screen time increased by 59 ± 112 min/d and 62 ± 130 min/d during week and weekend days, respectively. Conclusions Children were less physically active, and screen time was higher during and after the school closures due to the COVID-19 lockdown. This is alarming as an active lifestyle in children is crucial in preventing chronic diseases such as obesity.

The hypertensive pregnancy disorder preeclampsia (PE) is a leading cause of fetal and maternal morbidity/mortality. Obesity increases the risk to develop PE, presumably via the release of inflammatory mediators from the adipose tissue, but the exact etiology remains largely unknown. Using obese PE-like blood pressure high subline 5 (BPH/5) and lean gestational age-matched C57Bl6 mice, we aimed to obtain insight into differential reproductive white adipose tissue (rWAT) gene expression, circulating lipids and inflammation at the maternal-fetal interface during early pregnancy. In addition, we investigated the effect of 7 days 25% calorie restriction (CR) in early pregnancy on gene expression in rWAT and implantation sites. Compared with C57Bl6, female BPH/5 are dyslipidemic before pregnancy and show an amplification of rWAT mass, circulating cholesterol, free fatty acids, and triacylglycerol levels throughout pregnancy. RNA sequencing showed that pregnant BPH/5 mice have elevated gene enrichment in pathways related to inflammation and cholesterol biosynthesis at embryonic day ( e) 7.5. Expression of cholesterol-related HMGCS1, MVD, Cyp51a1, and DHCR was validated by quantitative reverse-transcription-polymerase chain reaction. CR during the first 7 days of pregnancy restored the relative mRNA expression of these genes to a level comparable to C57Bl6 pregnant females and reduced the expression of circulating leptin and proinflammatory prostaglandin synthase 2 in both rWAT and implantation sites in BPH/5 mice at e7.5. Our data suggest a possible role for rWAT in the dyslipidemic state and inflammatory uterine milieu that might underlie the pathogenesis of PE. Future studies should further address the physiological functioning of the adipose tissue in relation to PE-related pregnancy outcomes.

Simple Summary Preeclampsia is a life-threatening disorder that occurs in 10% of pregnant women worldwide. It presents as high blood pressure and multi-organ damage that when left untreated can result in death to both mother and baby. Treatment involves delivery of the placenta as well as the baby, often prematurely. Unfortunately, the cause of preeclampsia is unknown. However, there are known risk factors in women that may contribute to preeclampsia, including obesity. Increased adipose tissue (fat) has the potential to promote inflammation during pregnancy, which may negatively impact development of the baby and placenta, and lead to preeclampsia. This study aimed to show that reversal of maternal obesity through diet lowers inflammation in the fat and improves placental development, both of which have been shown to be necessary for pregnancy success. Utilizing obese female mice that demonstrate signs of preeclampsia (BPH/5), we showed that calorie restriction lowered inflammatory immune factors (complement) in the fat and restored essential growth factors in the developing placenta. In conclusion, these data suggest that targeting maternal obesity using calorie restriction and weight loss may improve pregnancy outcomes. Further studies are necessary to determine the influence of fat reduction in women and their likelihood of developing preeclampsia. Abstract Preeclampsia (PE) is a serious hypertensive disorder of pregnancy characterized by abnormal placental development with an unknown etiology. To better understand which women will develop PE, a number of maternal risk factors have been identified, including obesity. Visceral white adipose tissue (WAT) contains inflammatory mediators that may contribute to PE. To explore this, we utilized the blood pressure high (BPH)/5 mouse model of superimposed PE that spontaneously recapitulates the maternal PE syndrome. We hypothesized that BPH/5 visceral WAT adjacent to the female reproductive tract (reproductive WAT) is a source of complement factors that contribute to the inflammatory milieu and angiogenic imbalance at the maternal–fetal interface in this model and in preeclamptic women. To test our hypothesis, we calorie-restricted BPH/5 females for two weeks prior to pregnancy and the first seven days of pregnancy, which attenuated complement component 3 (C3) but not complement factor B, nor complement factor D, (adipsin) in the reproductive WAT or the implantation site in BPH/5. Furthermore, calorie restriction during pregnancy restored vascular endothelial and placental growth factor mRNA levels in the BPH/5 implantation site. These data show maternal reproductive WAT may be a source of increased C3 during pregnancy, which is increased at the maternal–fetal interface in preeclamptic BPH/5 mice. It also suggests that calorie restriction could regulate inflammatory mediators thought to contribute to placental dysfunction in PE. Future studies are necessary to examine the effect of calorie restriction on C3 throughout pregnancy and the role of maternal obesity in PE.

Preeclampsia (PE), a hypertensive disease of pregnancy, is a leading cause of fetal and maternal morbidity/mortality. Early angiogenic and inflammatory disturbances within the placenta are thought to underlie the development of the maternal PE syndrome and poor pregnancy outcomes. However, the exact etiology remains largely unknown. Here, we use the BPH/5 mouse model of PE to elucidate the way in which inflammation early in pregnancy contributes to abnormal expression of angiogenic factors at the maternal-fetal interface. We have previously described improvement in maternal hypertension and fetal growth restriction in this model after treatment with the anti-inflammatory cyclooxygenase-2 (Cox2) specific inhibitor celecoxib. To further characterize the mechanisms by which celecoxib improves poor pregnancy outcomes in BPH/5 mice, we determined expression of angiogenic factors and complement pathway components after celecoxib. In BPH/5 implantation sites there was increased hypoxia inducible factor-1α ( Hif1α), heme oxygenase-1 ( Ho-1), and stem cell factor ( Scf) mRNA concomitant with elevated prostaglandin synthase 2 ( Ptgs2), encoding Cox2, and elevated VEGF protein. Angiopoietin 1 ( Ang1), tunica interna endothelial cell kinase-2 receptor ( Tie2), complement factor 3 ( C3), and complement factor B ( CfB) were increased in midgestation BPH/5 placentae. Whereas BPH/5 expression levels of VEGF, Ang1, and Tie2 normalized after celecoxib, placental C3 and CfB mRNA remained unchanged. However, celecoxib did reduce the pregnancy-specific circulating soluble fms-like tyrosine kinase-1 (sFlt-1) rise in BPH/5 mice at midgestation. These data show that elevated Cox2 during implantation contributes to placental angiogenic factor imbalances in the BPH/5 mouse model of PE.

Background: Changes in the microbiota composition have been implicated in the development of obesity and type 2 diabetes. However, not much is known on the involvement of gut microbiota in lipid and cholesterol metabolism. In addition, the gut microbiota might also be a potential source of plasma oxyphytosterol and oxycholesterol concentrations (oxidation products of plant sterols and cholesterol). Therefore, the aim of this study was to modulate the gut microbiota by antibiotic therapy to investigate effects on parameters reflecting cholesterol metabolism and oxyphytosterol concentrations.Design: A randomized, double blind, placebo-controlled trial was performed in which 55 obese, prediabetic men received oral amoxicillin (broad-spectrum antibiotic), vancomycin (antibiotic directed against Gram-positive bacteria) or placebo (microcrystalline cellulose) capsules for 7 days (1500 mg/day). Plasma lipid and lipoprotein, non-cholesterol sterol, bile acid and oxy(phyto)sterol concentrations were determined at baseline and after 1-week intervention.Results: Plasma secondary bile acids correlated negatively with cholestanol (marker for cholesterol absorption, r = -0.367; P Conclusion: Despite strong correlations between plasma bile acid concentrations and cholesterol metabolism (synthesis and absorption), amoxicillin and vancomycin treatment for 7 days did not affect plasma lipid and lipoprotein, plasma non-cholesterol sterol and oxy(phyto)sterol concentrations in obese, pre-diabetic men. (C) 2017 Elsevier B.V. All rights reserved.

Patients with chronic kidney disease (CKD) and loss of kidney function are at increased risk for morbidity and mortality. The risks of CKD are attributed to “uremia,” an increased concentration of uremic retention solutes (toxins) in the plasma. Recently, a colo-renal axis became clearly apparent and uremia has been associated with an altered gut microbiome composition and metabolism. There is a high prevalence of anemia in patients with CKD, for which patients are often treated with oral or intravenous iron. Recent in vivo and in vitro studies have reported adverse effects of oral iron supplementation on the gut microbiota composition, gut metabolome, and intestinal health, which in turn may result in an increased production of uremic toxins. It may also affect circulating levels of other microbe-derived molecules, that can act as mediators of immune regulation. Changes in body iron levels have also been reported to exert subtle effects on host immune function by modulating immune cell proliferation and differentiation, and by directly regulating cytokine formation and antimicrobial immune effector mechanisms. Based on the foregoing it is conceivable that oral iron supplementation in iron deficient predialysis CKD patients adversely changes gut microbiota composition, the gut and systemic metabolome, and host immunity and infection. Future studies are needed to confirm these hypotheses and to assess whether, compared to IV iron supplementation, oral iron supplementation negatively impacts on morbidity of CKD, and whether these adverse effects depend on the iron bioavailability of the iron formulation to the microbiota.

Background: Although children seem to be at a lower risk for severe COVID-19 infection, governmental regulations to prevent the spread of the virus possibly affect their lifestyle and related health. In the Netherlands, controlled lock-down measures included closure of schools, daycare and sports facilities. In this study screen time and self-reported and objectively measured physical activity (PA) was investigated among Dutch children before and during the COVID-19 pandemic. Methods: Data derived from two different cohorts were used. In cohort A (102 children, 10.5 ± 3.6 year, 42.4% boys) PA and screen time were evaluated with questionnaires regarding the pre-pandemic situation and regarding the situation during the COVID-19 pandemic. 131 children (10.2 ± 0.9 year, 43.5% boys) from cohort B filled out questionnaires on PA and screen time and wore an ActiGraph accelerometer, after reopening of schools and one year earlier. Findings: Seventy-five percent of children in cohort A reported less total PA during the controlled lock-down. Total screen time on weekdays significantly increased by 34± 105 min/day. Compared to May 2019, children in cohort B reported to spend less time on sports during the pandemic. Objectively measured sedentary time increased with 45 ± 67 min/day compared to May 2019. Children that spent a minimum of 60 min/day on moderate-to-vigorous intensity PA decreased from 64% to 20%. Screen time increased by 59 ± 112 min/day on week days and 62 ± 130 min/day on weekend days for children in cohort B. Interpretation: During the COVID-19 pandemic, PA levels decreased and screen time increased during and directly after the controlled lockdown. This is alarming as a healthy, active lifestyle in children is crucial in preventing chronic diseases. Trial Registration: Clinicaltrials.gov (NCT04411511 and NCT03440580), for cohort A and B respectively. Funding: Data from children from cohort B was collected from an ongoing study which received funding from Province Limburg (SAS-2015-04956). Declaration of Interests: The authors declare no competing interest. Ethics Approval Statement: Both studies were reviewed and approved by the Medical Ethics Committee of the Maastricht University Medical Centre+ (METC2020-1330-A-1 and METC172043/NL64324.068.17).

Introduction: Preeclampsia (PE) is a hypertensive disease of pregnancy that affects an estimated 8% of women worldwide. The underlying mechanism is unknown; however, maternal obesity increases the risk of PE by 30% and may contribute to increased inflammation seen in preeclamptic mothers. Hypothesis: To better understand the role of white adipose tissue (WAT) signaling on adverse pregnancy outcomes, we used the obese PE-like BPH/5 mouse to test the hypothesis that visceral WAT has an inflammatory phenotype prior to the presentation of the maternal hypertensive syndrome Methods: Visceral WAT adjacent to the reproductive tract (“reproductive WAT”) was harvested from ad libitum fed control C57 and BPH/5 female mice (8 weeks of age) at embryonic day (e) 7.5. RNA was isolated and subjected to Next Generation Sequencing (NGS) using an Illumina platform. DAVID pathway analysis was performed to annotate differentially expressed genes. BPH/5 female mice were calorie restricted by 25% from e0.5 until e7.5 and reproductive WAT was collected for RNA isolation and quantitative real-time PCR. The calorie restriction paradigm has been shown to significantly reduce reproductive WAT accumulation throughout gestation in BPH/5 mice. Results: NGS of e7.5 reproductive WAT revealed 899 genes that were significantly dysregulated in BPH/5 vs C57. DAVID showed upregulation of lipid metabolic processes in both C57 and BPH/5 pregnant reproductive WAT, while 18 inflammation-related pathways were significantly upregulated in reproductive WAT of pregnant BPH/5 mice compared to pregnant C57 (FDR=1.5). Quantitative real-time PCR confirmed upregulation of PE- related inflammatory genes, interleukin (IL)-6, IL-15 and Ptgs2, in e7.5 BPH/5 reproductive WAT vs C57 (n=6, p Conclusions: These data show that obese PE-like BPH/5 mice have elevated inflammatory gene expression in reproductive WAT before placenta formation. Further investigations are needed to confirm if the reduction in IL-6 and Ptgs2 in reproductive WAT by calorie restriction improves fetoplacental and maternal outcomes in BPH/5 mice

Background Preeclampsia (PE) is a hypertensive disease of pregnancy that is a leading cause of fetal and maternal morbidity/mortality. Obesity is a risk factor for developing PE, however, the under...

The intestinal microbiota may contribute to the development of obesity by affecting host lipid metabolism and insulin sensitivity. To investigate the effects of microbiota manipulation on ex vivo basal and beta-adrenergically-stimulated lipolysis in human adipocytes, 36 obese men were randomized to amoxicillin (broad-spectrum antibiotic), vancomycin (narrow-spectrum antibiotic) or placebo treatment (7 d, 1500 mg/d). Before and after treatment, ex vivo adipose tissue lipolysis was assessed under basal conditions and during stimulation with the non-selective beta-agonist isoprenaline using freshly isolated mature adipocytes. Gene (targeted microarray) and protein expression were analyzed to investigate underlying pathways. Antibiotics treatment did not significantly affect basal and maximal isoprenaline-mediated glycerol release from adipocytes. Adipose tissue beta-adrenoceptor expression or post-receptor signalling was also not different between groups. In conclusion, 7 d oral antibiotics treatment has no effect on ex vivo lipolysis in mature adipocytes derived from adipose tissue of obese insulin resistant men.

Patients with chronic kidney disease (CKD) and loss of kidney function are at increased risk for morbidity and mortality. The risks of CKD are attributed to "uremia," an increased concentration of uremic retention solutes (toxins) in the plasma. Recently, a colo-renal axis became clearly apparent and uremia has been associated with an altered gut microbiome composition and metabolism. There is a high prevalence of anemia in patients with CKD, for which patients are often treated with oral or intravenous iron. Recent in vivo and in vitro studies have reported adverse effects of oral iron supplementation on the gut microbiota composition, gut metabolome, and intestinal health, which in turn may result in an increased production of uremic toxins. It may also affect circulating levels of other microbe-derived molecules, that can act as mediators of immune regulation. Changes in body iron levels have also been reported to exert subtle effects on host immune function by modulating immune cell proliferation and differentiation, and by directly regulating cytokine formation and antimicrobial immune effector mechanisms. Based on the foregoing it is conceivable that oral iron supplementation in iron deficient predialysis CKD patients adversely changes gut microbiota composition, the gut and systemic metabolome, and host immunity and infection. Future studies are needed to confirm these hypotheses and to assess whether, compared to IV iron supplementation, oral iron supplementation negatively impacts on morbidity of CKD, and whether these adverse effects depend on the iron bioavailability of the iron formulation to the microbiota.

Gut microbiota composition may play an important role in the development of obesity-related comorbidities. However, only few studies have investigated gender-differences in microbiota composition and gender-specific associations between microbiota or microbial products and insulin sensitivity. Insulin sensitivity (hyperinsulinemic-euglycemic clamp), body composition (dual energy X-ray absorptiometry), substrate oxidation (indirect calorimetry), systemic inflammatory markers and microbiota composition (PCR) were determined in male (n=15) and female (n=14) overweight and obese subjects. Bacteroidetes/Firmicutes-ratio was higher in men than in women (P=0.001). Bacteroidetes/Firmicutes-ratio was inversely related to peripheral insulin sensitivity only in men (men: P=0.003, women: P=0.882). This association between Bacteroidetes/Firmicutes-ratio and peripheral insulin sensitivity did not change after adjustment for dietary fibre and saturated fat intake, body composition, fat oxidation and markers of inflammation. Bacteroidetes/Firmicutes-ratio was not associated with hepatic insulin sensitivity. Men and women differ in microbiota composition and its impact on insulin sensitivity, implying that women might be less sensitive to gut microbiota-induced metabolic aberrations than men. This trial was registered at clinicaltrials.gov as NCT02381145.

Contains fulltext : 117918.pdf (Publisher’s version ) (Closed access) During chronic kidney disease (CKD), drug metabolism is affected leading to changes in drug disposition. Furthermore, there is a progressive accumulation of uremic retention solutes due to impaired renal clearance. Here, we investigated whether uremic toxins can influence the metabolic functionality of human conditionally immortalized renal proximal tubule epithelial cells (ciPTEC) with the focus on UDP-glucuronosyltransferases (UGTs) and mitochondrial activity. Our results showed that ciPTEC express a wide variety of metabolic enzymes, including UGTs. These enzymes were functionally active as demonstrated by the glucuronidation of 7-hydroxycoumarin (7-OHC; K(m) of 12+/-2muM and a V(max) of 76+/-3pmol/min/mg) and p-cresol (K(m) of 33+/-13muM and a V(max) of 266+/-25pmol/min/mg). Furthermore, a wide variety of uremic toxins, including indole-3-acetic acid, indoxyl sulfate, phenylacetic acid and kynurenic acid, reduced 7-OHC glucuronidation with more than 30% as compared with controls (p

The gut microbiota has been implicated in obesity and cardiometabolic diseases, although evidence in humans is scarce. We investigated how gut microbiota manipulation by antibiotics (7-day administration of amoxicillin, vancomycin, or placebo) affects host metabolism in 57 obese, prediabetic men. Vancomycin, but not amoxicillin, decreased bacterial diversity and reduced Firmicutes involved in short-chain fatty acid and bile acid metabolism, concomitant with altered plasma and/or fecal metabolite concentrations. Adipose tissue gene expression of oxidative pathways was upregulated by antibiotics, whereas immune-related pathways were downregulated by vancomycin. Antibiotics did not affect tissue-specific insulin sensitivity, energy/substrate metabolism, postprandial hormones and metabolites, systemic inflammation, gut permeability, and adipocyte size. Importantly, energy harvest, adipocyte size, and whole-body insulin sensitivity were not altered at 8-week follow-up, despite a still considerably altered microbial composition, indicating that interference with adult microbiota by 7-day antibiotic treatment has no clinically relevant impact on metabolic health in obese humans.

P-glycoprotein (P-gp) is an ATP-dependent transporter localized at the apical membrane of the kidney proximal tubules, which plays a role in the efflux of cationic and amphipathic endogenous waste products and xenobiotics, such as drugs, into urine. Studies in mice deficient in P-gp showed generalized proximal tubular dysfunction similar to the phenotype of patients with cystinosis, an autosomal recessive disorder caused by mutations in the lysosomal cystine transporter cystinosin. Renal disease in cystinosis is characterized by generalized dysfunction of the apical proximal tubular influx transporters (so-called renal Fanconi syndrome) developing during infancy and gradually progressing towards end-stage renal disease before the 10th birthday in the majority of patients that are not treated with the cystine-depleting drug cysteamine. Here, we investigated whether the proximal tubular efflux transporter P-gp is affected in cystinosis and whether this might contribute to the development of renal Fanconi syndrome. We used conditionally immortalized (ci) proximal tubular epithelial cells (ciPTEC) derived from cystinotic patients and healthy volunteers. P-gp-mediated transport was measured by using the P-gp substrate calcein-AM in the presence and absence of the P-gp-inhibitor PSC833. P-gp activity was normal in cystinotic cells as compared to controls. Additionally, the effect of cysteamine on P-gp transport activity and phosphate uptake was determined; demonstrating increased P-gp activity in cystinotic cells, and further decrease of proximal tubular phosphate uptake. This observation is compatible with the persistence of renal Fanconi syndrome in vivo under cysteamine therapy. In summary, P-gp expression and activity are normal in cystinotic ciPTEC, indicating that P-gp dysfunction is not involved in the pathogenesis of cystinosis. ispartof: Pharmaceutics vol:3 issue:4 pages:782-792 ispartof: location:Switzerland status: Published online

// Birce Akpinar 1 , Ethiene V. Bracht 1 , Dorin Reijnders 1 , Barbora Safarikova 2 , Iva Jelinkova 2 , Alf Grandien 3 , Alena Hyrslova Vaculova 1, 2 , Boris Zhivotovsky 1 , Magnus Olsson 1 1 Division of Toxicology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden 2 Department of Cytokinetics, Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i., Brno, Czech Republic 3 Department of Medicine, Center for Infectious Medicine, Karolinska Institutet, Karolinska University Hospital–Huddinge, Stockholm, Sweden Correspondence to: Boris Zhivotovsky, e-mail: Boris.Zhivotovsky@ki.se Keywords: colon cancer, apoptosis, 5-fluorouracil, p53, necrosis Received: July 22, 2015 Accepted: October 12, 2015 Published: October 24, 2015 ABSTRACT Despite recent advances in targeted therapeutics, administration of 5-fluorouracil (5-FU) remains a common clinical strategy for post-surgical treatment of solid tumors. Although it has been proposed that RNA metabolism is disturbed by 5-FU treatment, the key cytotoxic response is believed to be enzymatic inhibition of thymidylate synthase resulting in nucleotide pool disproportions. An operating p53 tumor suppressor signaling network is in many cases essential for the efficiency of chemotherapy, and malfunctions within this system remain a clinical obstacle. Since the fate of chemotherapy-insensitive tumor cells is rarely described, we performed a comparative analysis of 5-FU toxicity in p53-deficient cells and conclude that p53 acts as a facilitator rather than a gatekeeper of cell death. Although p53 can act as a regulator of several cellular stress responses, no rerouting of cell death mode was observed in absence of the tumor suppressor. Thus, the final death outcome of 5-FU-treated p53 -/- cells is demonstrated to be caspase-dependent, but due to a slow pace, accumulation of mitochondrial reactive oxygen species contributes to necrotic characteristics. The oligomerization status of the p53 target gene DR5 is determined as a significant limiting factor for the initiation of caspase activity in an intracellular TRAIL-dependent manner. Using several experimental approaches, we further conclude that RNA-rather than DNA-related stress follows by caspase activation irrespectively of p53 status. A distinct 5-FU-induced stress mechanism is thereby functionally connected to a successive and discrete cell death signaling pathway. Finally, we provide evidence that silencing of PARP-1 function may be an approach to specifically target p53-deficient cells in 5-FU combinatorial treatment strategies. Together, our results disclose details of impaired cell death signaling engaged as a consequence of 5-FU chemotherapy. Obtained data will contribute to the comprehension of factors restraining 5-FU efficiency, and by excluding DNA as the main stress target in some cell types they propose alternatives to currently used and suggested synergistic treatment regimens.

Present: Due to a technical error during image processing, the same picture set of control cells were used in TEM figures for both HCT116 wt and p53−/− cells. Figure ​Figure2B2B and Supplementary Figure 2 were affected.

Obesity has been associated with changes in the composition and function of the intestinal microbiota. Modulation of the microbiota by antibiotics also alters bile acid and glucose metabolism in mice. Hence, we hypothesized that short term administration of oral antibiotics in humans would affect fecal microbiota composition and subsequently bile acid and glucose metabolism. In this single blinded randomized controlled trial, 20 male obese subjects with metabolic syndrome were randomized to 7 days of amoxicillin 500 mg t.i.d. or 7 days of vancomycin 500 mg t.i.d. At baseline and after 1 week of therapy, fecal microbiota composition (Human Intestinal Tract Chip phylogenetic microarray), fecal and plasma bile acid concentrations as well as insulin sensitivity (hyperinsulinemic euglycemic clamp using [6,6-(2)H2]-glucose tracer) were measured. Vancomycin reduced fecal microbial diversity with a decrease of gram-positive bacteria (mainly Firmicutes) and a compensatory increase in gram-negative bacteria (mainly Proteobacteria). Concomitantly, vancomycin decreased fecal secondary bile acids with a simultaneous postprandial increase in primary bile acids in plasma (p