Ultrasmall Gold Nanoparticles
Three‐dimensional cell culture models represent a bridge between conventional two‐dimensional cell culture studies and in‐vivo animal experiments. In article number ...2201167, Astrid M. Westendorf, Matthias Epple, and co‐workers demonstrate the cytostatic action of doxorubicin‐carrying ultrasmall gold nanoparticles, including their superior ability to enter the three‐dimensional cell cultures compared to dissolved drugs.
Anti-neutrophil cytoplasmic autoantibodies (ANCA) targeting proteinase 3 (PR3) and myeloperoxidase expressed by innate immune cells (neutrophils and monocytes) are salient diagnostic and pathogenic ...features of small vessel vasculitis, comprising granulomatosis with polyangiitis (GPA), microscopic polyangiitis, and eosinophilic GPA. Genetic studies suggest that ANCA-associated vasculitides (AAV) constitute separate diseases, which share common immunological and pathological features, but are otherwise heterogeneous. The successful therapeutic use of anti-CD20 antibodies emphasizes the prominent role of ANCA and possibly other autoantibodies in the pathogenesis of AAV. However, to elucidate causal effects in AAV, a better understanding of the complex interplay leading to the emergence of B lymphocytes that produce pathogenic ANCA remains a challenge. Different scenarios seem possible; e.g., the break of tolerance induced by a shift from non-pathogenic toward pathogenic autoantigen epitopes in inflamed tissue. This review gives a brief overview on current knowledge about genetic and epigenetic factors, barrier dysfunction and chronic non-resolving inflammation, necro-inflammatory auto-amplification of cellular death and inflammation, altered autoantigen presentation, alternative complement pathway activation, alterations within peripheral and inflamed tissue-residing T- and B-cell populations, ectopic lymphoid tissue neoformation, the characterization of PR3-specific T-cells, properties of ANCA, links between autoimmune disease and infection-triggered pathology, and animal models in AAV.
Recommended treatment options for advanced-stage hepatocellular carcinoma (HCC) include systemic therapy (ST) and trans-arterial radioembolization (TARE) with Yttrium-90 (Y90). Before the approval of ...immune-checkpoint inhibitors, a similar safety profile was reported for TARE and ST with tyrosine kinase inhibitors (TKI). However, whole-liver treatment and underlying cirrhosis were identified as risk factors for potentially lethal radioembolization-induced liver disease (REILD). Therefore, the safety and efficacy of TARE and ST with atezolizumab/bevacizumab were compared in patients with advanced HCC involving at least both liver lobes in a retrospective real-world cohort. In total, 74 patients with new or recurrent advanced-stage HCC (BCLC stage B/C) were included if treated with either bilobar TARE (n = 33) or systemic combination therapy with atezolizumab plus bevacizumab (n = 41). Most patients had compensated liver function (90.5% were classified as Child-Pugh Score A, 73% as ALBI Grade 1) at baseline. Although not significant, patients treated with ST showed a more prolonged overall survival than those treated with Y90 TARE (7.1 months vs. 13.0 months, p = 0.07). While a similar disease control rate could be achieved with bilobar TARE and atezolizumab/bevacizumab, in the TARE group, overall survival was curtailed by the occurrence of REILD. In patients with underlying liver cirrhosis, the liver function at baseline was a predictor for REILD.
A variety of amino acid substitutions in the NS3-4A protease of the hepatitis C virus lead to protease inhibitor (PI) resistance. Many of these significantly impair the replication fitness of the ...resistant variants in a genotype- and subtype-dependent manner, a critical factor in determining the probability with which resistant variants will persist. However, the underlying molecular mechanisms are unknown. Here, we present a novel residue-interaction network approach to determine how near-neighbor interactions of PI resistance mutations in NS3-4A can impact protease functional sites dependent on their genomic background. We constructed subtype-specific consensus residue networks for subtypes 1a and 1b from protease structure ensembles combined with biological properties of protein residues and evolutionary amino acid conservation. By applying local and global network topology analysis and visual exploration, we characterize PI resistance-associated sites and outline differences in near-neighbor interactions. We find local residue-interaction patterns and features at protease functional sites that are subtype specific. The noncovalent bonding patterns indicate higher fitness costs conferred by PI resistance mutations in a subtype 1b genomic background and explain the prevalence of Q80K and R155K in subtype 1a. Based on local residue interactions, we predict a subtype-specific role for the protease residue NS3–Q80 in molecular mechanisms related to the assembly of infectious virus particles that is supported by experimental data on the capacity of Q80K variants to replicate and produce infectious virus in subtype 1a and 1b cell culture.
Display omitted
•A novel graph-based approach is applied to characterize multiple NS3-4A structure models.•Residue-interaction patterns at PI resistance sites are HCV subtype specific.•PI resistance sites are closer to NS3-4A protease functional sites in subtype 1b than 1a.•NS3–Q80K impairs infectious virus particle assembly specifically in subtype 1b.•This paper highlights subtype-specific molecular mechanisms in RAV persistence.
Abstract
Background
The efficacy of antibiotic prophylaxis to prevent spontaneous bacterial peritonitis (SBP) in patients colonized with multidrug-resistant organisms (MDROs) is unknown. We evaluated ...the effectiveness of fluoroquinolone-based SBP prophylaxis in an era and area of frequent antibiotic resistance.
Methods
This is a prospective observational study in patients with liver cirrhosis and an indication for fluoroquinolone-based prophylaxis of SBP. Patients were recruited and followed in a large German tertiary reference center with comprehensive microbiological and clinical monitoring performed at baseline and after 30, 60, 90, and 180 days of prophylaxis.
Results
Overall, 77 patients received antibiotic prophylaxis for an average of 93 days. Baseline prevalence of colonization with MDROs was high (N = 39, 50.6%). At least one de novo MDRO was detected in 27 patients (35.1%) during antibiotic prophylaxis; 33 patients (42.9%) developed secondary infections, including 14 cases (17.9%) of infections with MDROs, and 13 cases (16.9%) of de novo/recurrent SBP. Thirty patients (39.0%) died during follow-up. Significantly higher risks of SBP development during antibiotic prophylaxis were observed for patients with versus without any apparent MDROs (P = .009), vancomycin-resistant enterococci (P = .008), multidrug-resistant gram-negative bacteria (P = .016), or quinolone-resistant gram-negative bacteria (QR-GNB) (P = .015). In competing risk analysis, QR-GNB were independently associated with prophylaxis failure (hazard ratio, 3.39; P = .045) and infections with QR-GNB were independently associated with death before SBP (subdistribution hazard risk, 6.47; P = .034).
Conclusions
Antibiotic prophylaxis of SBP appears to be less efficient in patients with known MDROs. Regular MDRO screening seems to be useful to tailor treatment of secondary infections and re-evaluate antibiotic prophylaxis in case of selection of quinolone resistance.
In this prospective observational study in patients with liver cirrhosis, fluoroquinolone-based prophylaxis of Spontaneous Bacterial Peritonitis appears to be less efficient in patients with known multidrug-resistant organisms (MDROs). Regular MDRO screening might be useful to tailor and re-evaluate individual antibiotic prophylaxis.
The treatment of hepatocellular carcinoma (HCC) is undergoing a historic transformation with the approval of several new systemic therapies in the last few years. This study aimed to examine the ...impact of this changing landscape on survival and costs in a Western nationwide, real-world cohort.
A nationwide representative claims database (InGef) was screened for HCC cases between 2015 and 2020. Survival in an era with only sorafenib (period A, January 2015 to July 2018) and after approval of lenvatinib and other systemic treatments (period B, August 2018 to December 2020) was analysed. Health care costs were assessed.
We identified 2876 individuals with HCC in the study period. The proportion of patients receiving systemic therapy increased significantly over time, from 11.8% in 2015 to 15.1% in 2020 (p < 0.0001). The median overall survival in period B was 6.5 months (95% confidence interval CI: 4.9–8.9) and in period A was 5.3 months (95% CI: 4.5–6.3; p = 0.046). In period B, the median overall survival with lenvatinib was 9.7 months (95% CI: 6.3–18.4) versus 4.8 months with sorafenib (95% CI: 4.0–7.1, p = 0.008). Costs for prescription drugs per patient increased from €6150 in 2015 to €9049 in 2020 (p < 0.0001), and costs for outpatient care per patient increased from €1646 to €2149 (p = 0.0240).
The approval of new systemic therapies resulted in a survival benefit in patients with HCC. The magnitude of the effect is modest and associated with a moderate increase in health costs.
Display omitted
•Nationwide study of survival and costs trends in hepatocellular carcinoma.•Proportion of patients with systemic therapies increases over time.•Novel treatments include targeted agents and immunotherapies.•More systemic treatment options are associated with a longer survival.•A moderate increase in health care costs could be observed.
Hepatitis C virus (HCV) infection is associated with alterations in host lipid and insulin signaling cascades, which are partially explained by a dependence of the HCV life cycle on key molecules in ...these metabolic pathways. Yet, little is known on the role in the HCV life cycle of glycogen synthase kinase 3 (GSK3), one of the most important kinases in cellular metabolism. Therefore, the impact of GSK3 on the HCV life cycle was assessed in human hepatoma cell lines harboring subgenomic genotype 1b and 2a replicons or producing cell culture-derived HCV genotype 2a by exposure to synthetic GSK3 inhibitors, GSK3 gene silencing, overexpression of GSK3 constructs and immunofluorescence analyses. In addition, the role of GSK3 in hepatitis E virus (HEV) replication was investigated to assess virus specificity of the observed findings. We found that both inhibition of GSK3 function by synthetic inhibitors as well as silencing of GSK3β gene expression resulted in a decrease of HCV replication and infectious particle production, whereas silencing of the GSK3α isoform had no relevant effect on the HCV life cycle. Conversely, overexpression of GSK3β resulted in enhanced HCV replication. In contrast, GSK3β had no effect on replication of subgenomic HEV replicon. The pro-viral effect of GSK3β on HCV replication was mediated by supporting expression of microRNA-122 (miR-122), a micro-RNA which is mandatory for wild-type HCV replication, as GSK3 inhibitors suppressed miR-122 levels and as inhibitors of GSK3 had no antiviral effect on a miR-122-independent HCV mutant. In conclusion, we have identified GSK3β is a novel host factor supporting HCV replication by maintaining high levels of hepatic miR-122 expression.
Background and Aims
Hepatitis B virus (HBV) infection is a major cause of hepatocellular carcinoma (HCC) development and progression. The aim of this study was to mechanistically investigate the ...involvement of Hippo signalling in HBV surface antigen (HBsAg)‐dependent neoplastic transformation.
Methods
Liver tissue and hepatocytes from HBsAg‐transgenic mice were examined for the Hippo cascade and proliferative events. Functional experiments in mouse hepatoma cells included knockdown, overexpression, luciferase reporter assays and chromatin immunoprecipitation. Results were validated in HBV‐related HCC biopsies.
Results
Hepatic expression signatures in HBsAg‐transgenic mice correlated with YAP responses, cell cycle control, DNA damage and spindle events. Polyploidy and aneuploidy occurred in HBsAg‐transgenic hepatocytes. Suppression and inactivation of MST1/2 led to the loss of YAP phosphorylation and the induction of BMI1 expression in vivo and in vitro. Increased BMI1 directly mediated cell proliferation associated with decreased level of p16INK4a, p19ARF, p53 and Caspase 3 as well as increased Cyclin D1 and γ‐H2AX expression. Chromatin immunoprecipitation and the analysis of mutated binding sites in dual‐luciferase reporter assays confirmed that the YAP/TEAD4 transcription factor complex bound and activated the Bmi1 promoter. In chronic hepatitis B patients, paired liver biopsies of non‐tumour and tumour tissue indicated a correlation between YAP expression and the abundance of BMI1. In a proof‐of‐concept, treatment of HBsAg‐transgenic mice with YAP inhibitor verteporfin directly suppressed the BMI1‐related cell cycle.
Conclusion
HBV‐associated proliferative HCC might be related to the HBsAg‐YAP‐BMI1 axis and offer a potential target for the development of new therapeutic approaches.
PDF
