CD95 and TRAIL receptor-mediated activation of protein kinase C and NF-kappaB contributes to apoptosis resistance in ductal pancreatic adenocarcinoma cells.

The molecular alterations in tumour cells leading to resistance towards apoptosis induced by CD95 and TRAIL-receptors are not fully understood. We report here that the stimulation of the CD95- and TRAIL-resistant human pancreatic adenocarcinoma cell line PancTuI with an agonistic anti-CD95 antibody or TRAIL resulted in activation of protein kinase C and NF-kappaB. Inhibition of protein kinase C by G?6983 sensitized these cells to apoptotic challenges and strongly diminished activation of NF-kappaB by anti-CD95 and TRAIL. Similarly, inhibition of NF-kappaB by MG132 or by transient transfection with a dominant negative mutant of IkappaBalpha restored the responsiveness of PancTuI cells to both death ligands. In the CD95 and TRAIL-sensitive cell line Colo357 the induction of protein kinase C and NF-kappaB following activation of CD95 and TRAIL-R was very moderate compared with PancTuI cells. However, pre-incubation of these cells with PMA strongly reduced their apoptotic response to anti-CD95 and TRAIL. Taken together, we show that activation of protein kinase C operates directly in a death receptor-dependent manner in PancTuI cells and protect pancreatic tumour cells from anti-CD95 and TRAIL-mediated apoptosis by preventing the loss DeltaPsim and Cytochrome c release as well as by induction of NF-kappaB.     

Targeting the function of mature dendritic cells by human cytomegalovirus: a multilayered viral defense strategy.

Human cytomegalovirus (HCMV) can suppress and evade the immune system. We have identified as a mechanism the ability of HCMV to infect dendritic cells (DC), which initiate the antiviral immune response. HCMV-infected DC show enhanced expression of costimulatory molecules. In contrast, MHC molecules are partially downregulated, leading to a reduced antigen-presenting capacity. Moreover, the apoptosis-inducing ligands CD95L (FasL) and tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) are upregulated, thereby enabling HCMV-infected DC to delete activated T lymphocytes. This additional layer of viral defense is complemented by nondeletional mechanisms, which suppress surviving T cells. Thus, infection of DC allows the virus to blunt the antiviral T cell response by a multilayered defense strategy and could play a pivotal role in HCMV-triggered immunosuppression.     

Trends in coronary artery calcification in peritoneal dialysis and transplant patients.

Sir, In a recent issue of Nephrology Dialysis and Transplantation,an interesting paper by Moe and co-workers was published thathas shown a substantial difference in trends of coronary arterycalcification (CAC) progression between patients remaining ondialysis and those who underwent renal transplantation (RTx)[1]. We would like to share our experience on this topic. We performed CAC assessment using multi-slice spiral computedtomography (MSCT; Somatom Plus 4 Volume Zoom, Siemens AG, Erlangen,Germany) in 61 patients (28 female, 33 male, mean age 50.4±13.6years, on dialysis for a period     

Chlorhexidine resistance in antibiotic-resistant bacteria isolated from the surfaces of dispensers of soap containing chlorhexidine.

Bacterial contamination with pan-resistant Acinetobacter and Klebsiella, multidrug-resistant Pseudomonas, and methicillin-resistant Staphylococcus aureus (MRSA) was noted on the surfaces of dispensers of hand soap with 2% chlorhexidine. Gram-negative isolates could multiply in the presence of 1% chlorhexidine. In contrast, MRSA was inhibited in vitro by chlorhexidine at concentrations as low as 0.0019%.     

Morphological and carbogen-based functional MRI of a chemically induced liver tumor model in mice.

A multifocal mouse liver tumor model chemically induced with 5,9-dimethyl-7H-dibenzo[c,g]carbazole was investigated by respiratory-triggered morphological and functional MRI (fMRI) at 4.7 Tesla. The model is characterized by the presence of two tumor types: hypovascular cholangioma and vascularized hepatocellular carcinoma (HCC). Growth curves measured by 3D-MRI showed limited growth of cholangiomas and rapid growth of HCCs after a latency of about 25 weeks. Functional imaging based on T(2) (*)-weighted fast gradient-echo MRI and carbogen breathing was optimized for liver imaging in mice. A response to carbogen was observed in HCCs but not in cholangiomas. Transversal analysis (50 HCCs) of signal change upon carbogen revealed four different types of response patterns: 1) signal increase upon carbogen administration (74%); 2) small or insignificant signal change (10%), 3) transient signal decrease and delayed increase (8%), and 4) signal decrease (8%). Longitudinal follow-up of a subgroup (N = 17) showed that an initially observed type 1 response, attesting to the presence of a functional vasculature, remained stable for at least 3 weeks in 14 HCCs. A switch from a type 1 response to another response type may be useful for demonstrating, in a noninvasive manner, a disturbance of tumor vasculature induced by anti-vascular or anti-angiogenic therapy.     

Sudden Unexpected Death in Epilepsy: A Review of Incidence and Risk Factors

Summary:  Sudden unexpected death in epilepsy (SUDEP) is the most important direct epilepsy-related cause of death. However, SUDEP is rare in patients with new onset epilepsy and in patients in remission. Incidence is about 0.35 cases/1,000 person-years in population-based incidence cohort of epilepsy. Incidence is considerably higher in patients with chronic epilepsy, 1–2/1,000 person-years, and highest with severe, refractory seizures, 3–9/1,000. The highest rates occur from 20 to 40 years. Most SUDEP appears seizure-related. When witnessed, the fatal event generally occurred in association with generalized tonic–clonic seizure. Two recent case–control studies suggest that seizure frequency is the strongest risk factor for SUDEP: relative risk = 23 (95% CI = 3.2–170) for persons with ≥1 seizure during the year of observation versus seizure-free patients. Onset of epilepsy at an early age and long duration of the disorder are other risk factors. Although SUDEP has not been associated with the use of any particular antiepileptic drugs (AEDs), some case–control studies have pointed to an association between SUDEP and polytherapy with AEDs and frequent dose changes independent of seizure frequency. Although recent epidemiological studies have been helpful in identifying patients at risk for SUDEP, providing clues to mechanisms behind SUDEP, no single risk factor is common to all SUDEP, suggesting multiple mechanisms or trigger factors. Seizure control seems of paramount importance to prevent SUDEP. Further large-scale case–control studies are needed to assess the role of AEDs in order to form a basis for treatment strategies aiming at seizure control and prevention of SUDEP.     

Assessing the efficacy of allogeneic hematopoietic stem cells transplantation (allo‐HSCT) by analyzing survival end points in defined groups of acute myeloid leukemia patients: A retrospective,multicenter Polish Adult Leukemia Group study

The importance of allogeneic hematopoietic stem cell transplantation (allo‐HSCT) for survival outcomes in patients with acute myeloid leukemia (AML) currently remains unclear. The study aimed to compare measures of clinical treatment for patients with AML in CR1 (the first complete remission) with or without being subjected to allo‐HSCT. These consisted of leukemia‐free survival (LFS), overall survival (OS), cumulative incidence of relapse (CIR), and non‐relapse mortality disease (NRM). Subjects were 622 patients, median age of 44, forming part of the prospective, randomized, and multicenter clinical Polish Adult Leukemia Group trials during 1999–2008. The Mantel–Byar approach was used to assess allo‐HSCT on survival endpoints, accounting for a changing transplant status. Undergoing allo‐HSCT significantly improved the LFS and OS for the entire group of patients with AML in CR1, along with the DAC induction subgroup and for the group with unfavorable cytogenetics aged 41–60. The CIR demonstrated that allo‐HSCT reduced the risk of relapse for patients with AML in CR1 and those with an unfavorable cytogenetic risk. In addition, the NRM analysis showed that allo‐HSCT significantly reduced the risk of death unrelated to relapse for the entire group of AML patients in CR1 and aged 41–60. The allo‐HSCT treatment particularly benefitted survival for the AML in CR1 group having an unfavorable cytogenetic prognosis. Am. J. Hematol. 90:904–909, 2015. © 2015 Wiley Periodicals, Inc.     

Linear ubiquitination in immunity

Linear ubiquitination is a post-translational protein modification recently discovered to be crucial for innate and adaptive immune signaling. The function of linear ubiquitin chains is regulated at multiple levels: generation, recognition, and removal. These chains are generated by the linear ubiquitin chain assembly complex (LUBAC), the only known ubiquitin E3 capable of forming the linear ubiquitin linkage de novo. LUBAC is not only relevant for activation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinases (MAPKs) in various signaling pathways, but importantly, it also regulates cell death downstream of immune receptors capable of inducing this response. Recognition of the linear ubiquitin linkage is specifically mediated by certain ubiquitin receptors, which is crucial for translation into the intended signaling outputs. LUBAC deficiency results in attenuated gene activation and increased cell death, causing pathologic conditions in both, mice, and humans. Removal of ubiquitin chains is mediated by deubiquitinases (DUBs). Two of them, OTULIN and CYLD, are constitutively associated with LUBAC. Here, we review the current knowledge on linear ubiquitination in immune signaling pathways and the biochemical mechanisms as to how linear polyubiquitin exerts its functions distinctly from those of other ubiquitin linkage types.