Identification of microRNA-mRNA functional interactions in UVB-induced senescence of human diploid fibroblasts

BACKGROUND: Cellular senescence can be induced by a variety of extrinsic stimuli, and sustained exposure to sunlight is a key factor in photoaging of the skin. Accordingly, irradiation of skin fibroblasts by UVB light triggers cellular senescence, which is thought to contribute to extrinsic skin aging, although molecular mechanisms are incompletely understood. Here, we addressed molecular mechanisms underlying UVB induced senescence of human diploid fibroblasts. RESULTS: We observed a parallel activation of the p53/p21(WAF1) and p16(INK4a)/pRb pathways. Using genome-wide transcriptome analysis, we identified a transcriptional signature of UVB-induced senescence that was conserved in three independent strains of human diploid fibroblasts (HDF) from skin. In parallel, a comprehensive screen for microRNAs regulated during UVB-induced senescence was performed which identified five microRNAs that are significantly regulated during the process. Bioinformatic analysis of miRNA-mRNA networks was performed to identify new functional mRNA targets with high confidence for miR-15a, miR-20a, miR-20b, miR-93, and miR-101. Already known targets of these miRNAs were identified in each case, validating the approach. Several new targets were identified for all of these miRNAs, with the potential to provide new insight in the process of UVB-induced senescence at a genome-wide level. Subsequent analysis was focused on miR-101 and its putative target gene Ezh2. We confirmed that Ezh2 is regulated by miR-101 in human fibroblasts, and found that both overexpression of miR-101 and downregulation of Ezh2 independently induce senescence in the absence of UVB irradiation. However, the downregulation of miR-101 was not sufficient to block the phenotype of UVB-induced senescence, suggesting that other UVB-induced processes induce the senescence response in a pathway redundant with upregulation of miR-101. CONCLUSION: We performed a comprehensive screen for UVB-regulated microRNAs in human diploid fibroblasts, and identified a network of miRNA-mRNA interactions mediating UVB-induced senescence. In addition, miR-101 and Ezh2 were identified as key players in UVB-induced senescence of HDF

Nicotine and Cotinine Induce Neutrophil Extracellular Trap Formation-Potential Risk for Impaired Wound Healing in Smokers

Smoking undoubtedly affects human health. Investigating 2318 representative patients at a level 1 trauma center identified delayed wound healing, tissue infections, and/or sepsis as main complications in smokers following trauma and orthopedic surgery. Therefore, smoking cessation is strongly advised to improve the clinical outcome in these patients, although smoking cessation often fails despite nicotine replacement therapy raising the need for specific interventions that may reduce the complication rate. However, the underlying mechanisms are still unknown. In diabetics, delayed wound healing and infections/sepsis are associated with increased neutrophilic PADI4 expression and formation of neutrophil extracellular traps (NETs). The aim was to investigate if similar mechanisms hold for smokers. Indeed, our results show higher PADI4 expression in active and heavy smokers than non-smokers, which is associated with an increased complication rate. However, in vitro stimulation of neutrophils with cigarette smoke extract (CSE) only moderately induced NET formation despite accumulation of reactive oxygen species (ROS). Physiological levels of nicotine and its main metabolite cotinine more effectively induced NET formation, although they did not actively induce the formation of ROS, but interfered with the activity of enzymes involved in anti-oxidative defense and NET formation. In summary, we propose increased formation of NETs as possible triggers for delayed wound healing, tissue infections, and/or sepsis in smokers after a major trauma and orthopedic surgery. Smoking cessation might reduce this effect. However, our data show that smoking cessation supported by nicotine replacement therapy should be carefully considered as nicotine and its metabolite cotinine effectively induced NET formation in vitro, even without active formation of ROS

Elevated liver fibrosis index FIB-4 is not reliable for HCC risk stratification in predominantly non-Asian CHB patients

We aimed to validate the liver fibrosis index FIB-4 as a model for risk stratification of hepatocellular carcinoma development in predominantly non-Asian patients with chronic hepatitis B infection seen at a tertiary referral center in Germany.We retrospectively analyzed 373 adult patients with chronic hepatitis B infection. Patient demographics, hepatitis B markers, antiviral treatment, laboratory parameters, results from liver imaging and histology were recorded. Patients were divided into 2 groups according to their FIB-4 levels and their hazard ratios for developing hepatocellular carcinoma were analyzed adjusted for age, sex, body mass index, alcohol consumption, and antiviral medication.Median follow-up was 8.7 years (range 1-21.3 years), 93% of patients were of non-Asian origin, and 64% were male. Compared with patients with a low FIB-4 (<1.25) patients with FIB-4 1.25 showed a hazard ratio for incidence of hepatocellular carcinoma of 3.03 (95% confidence interval (CI): 1.24-7.41) and an adjusted hazard ratio of 1.75 (95% CI: 0.64-4.74). Notably, 68% of patients with liver cirrhosis and 68% of those who developed HCC during observation had a low FIB-4 (<1.25).We could not confirm that a FIB-4 value 1.25 is a reliable clinical indicator for incidence of hepatocellular carcinoma in predominantly non-Asian patients with chronic hepatitis B. Further studies in geographically and ethnically diverse populations are needed to prove its utility as a predictive tool

Comparison of Pre-Endoscopic C-WATCH Score with Established Risk Assessment Tools in Patients with Upper Gastrointestinal Bleeding

Introduction: Use of risk scores for early assessment of patients with upper gastrointestinal bleeding (UGIB) is recommended by various guidelines. We compared Cologne-WATCH (C-WATCH) score with Glasgow-Blatchford score (GBS), Rockall score (RS), and pre-endoscopic RS (p-RS). Methods: Patients with UGIB between January and December 2017 were retrospectively analyzed for 30-day mortality and composite endpoints risk of complications and need for intervention using areas under the receiver-operating characteristics curve (AUROC). Subgroup analysis was conducted for patients with UGIB on admission and in-hospital UGIB. Results: A total of 252 patients were identified (67.5% men, mean age 63.8 +/- 14.9 years). In-hospital UGIB occurred in 49.6%. AUROCs for 30-day mortality, risk of complications, and need for intervention (not applicable to RS) were 0.684 (95% confidence interval [CI]: 0.606-0.763), 0.665 (95% CI: 0.594-0.735), and 0.694 (95% CI: 0.612-0.775) for C-WATCH score, 0.724 (95% CI: 0.653-0.796) and 0.751 (95% CI: 0.687-0.815) for RS, 0.652 (95% CI: 0.57-0.735), 0.653 (95% CI: 0.579-0.727), and 0.673 (95% CI: 0.602-0.745) for p-RS and 0.652 (95% CI: 0.572-0.732), 0.663 (95% CI: 0.592-0.734), and 0.752 (95% CI: 0.683-0.821) for GBS. RS outperformed pre-endoscopic scores in predicting risk of complications, while there were no significant differences between pre-endoscopic scores except GBS outperforming p-RS in predicting need for intervention. The subgroup analysis obtained similar results. Positive predictive values for patients with estimated low risk for all three endpoints (C-WATCH score <= 1, RS <= 2, p-RS <1, and GBS <= 1) were 89%, 69%, 78%, and 92%. Conclusion: C-WATCH score performed similar to the established pre-endoscopic risk scores in patients with UGIB regarding relevant patient-related endpoints with no significant differences between both the subgroups

Insulin-like growth factor binding protein-6 delays replicative senescence of human fibroblasts

► Proteomic analysis of senescent secretome reveals upregulation of IGFBP-6 in fibroblasts. ► IGFBP-6 knockdown induces premature senescence in young fibroblasts. ► IGFBP-6 lentiviral overexpression delays replicative senescence in fibroblasts

Longitudinal relationship between B-type natriuretic peptide and anxiety in coronary heart disease patients with depression

Objective: Patients with coronary heart disease (CHD) suffer from physical limitations, but also from psychological distress. Natriuretic peptides may be involved in the neurobiological processes that modulate psychological adaptation, as they are increased in heart disease and seem to have an anxiolytic-like function. Longitudinal data on this association are scarce. Methods: To assess the relationship between NT-proBNP and anxiety (Hospital Anxiety and Depression Scale (HADS)), we used secondary data from a multicenter trial from baseline to 24 months. Patients (N = 308, 80.8% male, mean age 60.1 years) had stable CHD and moderate levels of depression (HADS >= 8). Results: Multiple linear regression adjusted for age, sex, BMI, and physical functioning revealed NT-proBNP as a significant predictor for anxiety at baseline, 1, 6, 12, 18, and 24 months (all p < .05). Linear mixed model analysis with the six anxiety measures as level-1 variable and NT-proBNP as fixed factor revealed a significant time*NT-proBNP interaction (t(1535.99) = -2.669, p = .01) as well as a significant time*NT-proBNP*sex-interaction (1(1535.99) = 3.277, p = .001), when NT-proBNP was dichotomized into lowest vs. the three highest quartiles. Conclusion: Our results indicate a stable negative association of baseline NT-proBNP with anxiety over two years. In men and women, different pathways modulating this relationship appear to be in effect. Female patients with very low NT-proBNP levels, despite their cardiac disease, show persistently higher levels of anxiety compared to women with higher levels of NT-proBNP and compared to men