TLR4 and RAGE conversely mediate pro-inflammatory S100A8/9-mediated inhibition of proliferation-linked signaling in myeloproliferative neoplasms

Purpose

Previously, the family of S100A proteins has been found to be associated with inflammation and myelopoiesis and to be able to induce or support myeloproliferation during chronic inflammation. Here, we studied the inflammatory myeloid-related proteins S100A4, S100A8, S100A9 and S100A12 in myeloproliferative neoplasms (MPNs) in order to assess the involvement of chronic inflammation in the pathogenesis of MPN.

Methods

We analyzed the S100A4, S100A8, S100A9 and S100A12 mRNA and protein levels in the bone marrow and circulation of 140 patients with MPN and 15 healthy controls using Western blotting, microarray-based mRNA expression profiling and ELISA assays, respectively. In addition we performed functional studies on the proliferation-related AKT and ERK1/2 signaling pathways in MPN-derived granulocytes using Western blotting and proteomic analyses.

Results

We found that the S100A mRNA levels were increased in MPN patient-derived circulatory CD34⁺ cells, and that their protein expression levels were also augmented in their granulocytes and bone marrow stroma cells, depending on the JAK2V617F mutation allele burden. We also found that calreticulin (CALR) mutations were related to reduced S100A8 plasma levels in primary myelofibrosis (PMF). The S100A8 plasma levels were found to be increased in MPN, the S100A9 plasma levels in PMF and essential thrombocythemia (ET), and the S100A12 plasma levels in polycythemia vera (PV). These S100A plasma levels showed a positive correlation with the systemic inflammation marker IL-8, as well as with the numbers of leukocytes and thrombocytes, depending on the JAK2V617F mutation status. Additionally, we found that heterodimeric S100A8/9 can inhibit the AKT pathway in MPN-derived granulocytes mediated by the Toll-like receptor 4 (TLR4), depending on the CALR mutation status. Conversely, we found that blocking of the receptor for advanced glycation end products (RAGE) increased the S100A8/9-mediated inhibition of AKT signaling in the MPN-derived granulocytes. Moreover, we found that heterodimeric S100A8/9 generally induced TLR4-mediated ERK1/2 dephosphorylation proportionally to the JAK2V617F mutation allele burden. TLR4/RAGE blocking prevented the S100A8/9-mediated inhibition of ERK1/2 phosphorylation in PV.

Conclusions

From our data we conclude that the S100A8 and S100A9 granulocyte and plasma levels are increased in MPN patients, along with inflammation markers, depending on their JAK2V617F mutation allele burden. We also found that S100A8/9-mediated inhibition of the proliferation-related AKT and ERK1/2 signaling pathways can be decreased by CALR mutation-dependent TLR4 blocking and increased by RAGE inhibition in MPN.

     

A positive-feedback mechanism promotes reovirus particle conversion to the intermediate associated with membrane penetration

Membrane penetration by reovirus is associated with conversion of a metastable intermediate, the ISVP, to a further-disassembled particle, the ISVP*. Factors that promote this conversion in cells are poorly understood. Here, we report the in vitro characterization of a positive-feedback mechanism for promoting ISVP* conversion. At high particle concentration, conversion approximated second-order kinetics, and products of the reaction operated in trans to promote the conversion of target ISVPs. Pore-forming peptide μ1N, which is released from particles during conversion, was sufficient for promoting activity. A mutant that does not undergo μ1N release failed to exhibit second-order conversion kinetics and also failed to promote conversion of wild-type target ISVPs. Susceptibility of target ISVPs to promotion in trans was temperature dependent and correlated with target stability, suggesting that capsid dynamics are required to expose the interacting epitope. A positive-feedback mechanism of promoting escape from the metastable intermediate has not been reported for other viruses but represents a generalizable device for sensing a confined volume, such as that encountered during cell entry.     

Impact of hypoxic hepatitis on mortality in the intensive care unit

Purpose

Hypoxic hepatitis (HH) is a form of hepatic injury following arterial hypoxemia, ischemia, and passive congestion of the liver. We investigated the incidence and the prognostic implications of HH in the medical intensive care unit (ICU).

Methods

A total of 1,066 consecutive ICU admissions at three medical ICUs of a university hospital were included in this prospective cohort study. All patients were screened prospectively for the presence of HH according to established criteria. Independent risk factors of mortality in this cohort of critically ill patients were identified by a multivariate Poisson regression model.

Results

A total of 118 admissions (11%) had HH during their ICU stay. These patients had different baseline characteristics, longer median ICU stay (8 vs. 6?days, p?p?p?p?p?=?0.359).

Conclusions

Hypoxic hepatitis (HH) occurs frequently in the medical ICU. The presence of HH is a strong risk factor for mortality in the ICU in patients requiring vasopressor therapy.     

The role of paclitaxel in the development and treatment of multidrug resistant cancer cell lines

Paclitaxel (PTX) is used for treatment of wide range of solid tumors, but its efficacy is often limited by appearance of multidrug resistance (MDR). We explored the MDR induced by PTX in human colon cancer DLD1 and glioblastoma U87 cell lines. After confirmation of the cross-resistance to other anticancer agents in newly established DLD1-TxR and U87-TxR, we analyzed the mRNA expression of membrane transporters involved in MDR. The cells had increased levels of mdr1 gene expression, while mrp1 was decreased. Flow cytometry analyzes showed that the accumulation of P-glycoprotein (P-gp) substrates (rhodamine 123 and doxorubicin) was significantly lower in DLD1-TxR and U87-TxR compared to DLD1 and U87, respectively. The significant depletion of gst-π gene expression and glutathione (GSH) concentration was observed in U87-TxR. The analysis of cell cycle kinetics revealed extensive cell death in colon cancer cells that were accumulated in subG0 phase after PTX treatment, while glioblastoma cells died during interphase (G1, S or G2). The secretion of vascular endothelial growth factor (VEGF) was inhibited by single PTX treatment of colon cancer and in continuous treatment of glioblastoma cell lines. In conclusion, continuous PTX treatment caused the over-expression of P-gp and acquisition of MDR in colon cancer and glioblastoma cell lines, while some mechanisms of MDR and tumor progression such as GSH detoxification system and VEGF secretion were suppressed. Hence, the present results implicate that PTX is an important clinical tool for colon cancer and glioblastoma treatment even in the presence of MDR.     

eCHAT for Lifestyle and Mental Health Screening in Primary Care

PURPOSE

Early detection and management of unhealthy behaviors and mental health issues in primary care has the potential to prevent or ameliorate many chronic diseases and increase patients’ well-being. This study aimed to assess the feasibility and acceptability of the systematic use of a Web-based eCHAT (electronic Case-finding and Help Assessment Tool) screening patients for problematic drinking, smoking, and other drug use, gambling, exposure to abuse, anxiety, depression, anger control, and physical inactivity, and whether they want help with these issues. Patients self-administered eCHAT on an iPad in the waiting room and received summarized results, including relevant scores and interpretations, which could be by a family physician on the website and in the electronic health record (EHR) at the point of care.

METHODS

We conducted a mixed method feasibility and acceptability study in 2 general practices in Auckland, New Zealand. Participants were consecutive adult patients attending the practice during a 2-week period, as well as all practice staff. Patients completed eCHAT, doctors accessed the summarized reports. Outcome measures were patients’ responses to eCHAT, and patients’ written and staff recorded interview feedback.

RESULTS

Of the 233 invited patients, 196 (84%) completed eCHAT and received feedback. Domains where patients wanted immediate help were anxiety (9%), depression (7%), physical activity (6%), and smoking (5%), which was not overwhelming for physicians to address. Most patients found the iPad easy to use, and the questions easy to understand and appropriate; they did not object to questions. Feedback from 7 doctors, 2 practice managers, 4 nurses, and 5 receptionists was generally positive. Practices continue to use eCHAT regularly since the research was completed.

CONCLUSIONS

eCHAT is an acceptable and feasible means of systemic screening patients for unhealthy behaviors and negative mood states and is easily integrated into the primary care electronic health record.     

Fatal skin and pulmonary infection caused by Hormographiella aspergillata in a leukaemic patient: case report and literature overview

Invasive systemic fungal infections are a major cause of morbidity and mortality in patients after hematopoietic stem cell transplantation. We report the case of a fatal infection with Hormographiella aspergillata in a patient undergoing allogenic peripheral blood stem cell transplantation for acute myeloid leukaemia.     

Hypoxic hepatitis: underlying conditions and risk factors for mortality in critically ill patients

Purpose  Hypoxic hepatitis (HH) is a frequent cause of acute hepatocellular damage at the intensive care unit. Although mortality is reported to be high, risk factors for mortality in this population are unknown. Methods  One-hundred and seventeen consecutive patients with HH were studied prospectively at three medical intensive care units of a university hospital. Results  The main causes of hypoxic hepatitis were low cardiac output and septic shock, and most patients (74%) had more than one underlying factor. Peak aspartate transaminase (P = 0.02), lactate dehydrogenase (P = 0.03), INR (P < 0.001) and lactate (P < 0.01) were higher in non-survivors. Prolonged duration of HH caused higher overall mortality rate (P = 0.03). INR > 2 (P = 0.02), septic shock (P = 0.01) and SOFA score >10 (P = 0.04) were risk factors of mortality in the regression model. Conclusions  Hypoxic hepatitis is the consequence of multiorgan injury. Outcome is influenced by the severity of liver impairment and the etiology and severity of the basic disease. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. The study was performed at the intensive care units 13H1, 13H3 and 13I2 of the Medical University of Vienna.