Astrid Schmieder

cFLIP Regulates Skin Homeostasis and Protects against TNF-Induced Keratinocyte Apoptosis

FADD, caspase-8, and cFLIP regulate the outcome of cell death signaling. Mice that constitutively lack these molecules die at an early embryonic age, whereas tissue-specific constitutive deletion of FADD or caspase-8 results in inflammatory skin disease caused by increased necroptosis. The function of cFLIP in the skin in vivo is unknown. In contrast to tissue-specific caspase-8 knockout, we show that mice constitutively lacking cFLIP in the epidermis die around embryonic days 10 and 11. When cFLIP expression was abrogated in adult skin of cFLIPfl/fl-K14CreERtam mice, severe inflammation of the skin with concomitant caspase activation and apoptotic, but not necroptotic, cell death developed. Apoptosis was dependent of autocrine tumor necrosis factor production triggered by loss of cFLIP. In addition, epidermal cFLIP protein was lost in patients with severe drug reactions associated with epidermal apoptosis. Our data demonstrate the importance of cFLIP for the integrity of the epidermis and for silencing of spontaneous skin inflammation.

Liver sinusoidal endothelium: A microenvironment-dependent differentiation program in rat including the novel junctional protein liver endothelial differentiation-associated protein-1†

Liver sinusoidal endothelium (LSEC) is a prime example of organ‐specific microvascular differentiation and functions. Disease‐associated capillarization of LSEC in vivo and dedifferentiation of LSEC in vitro indicate the importance of the hepatic microenvironment. To identify the LSEC‐specific molecular differentiation program in the rat we used a two‐sided gene expression profiling approach comparing LSEC freshly isolated ex vivo with both lung microvascular endothelial cells (LMEC) and with LSEC cultured for 42 hours. The LSEC signature consisted of 48 genes both down‐regulated in LMEC and in LSEC upon culture (fold change >7 in at least one comparison); quantitative reverse‐transcription polymerase chain reaction confirmation of these genes included numerous family members and signaling pathway‐associated molecules. The LSEC differentiation program comprised distinct sets of growth (Wnt2, Fzd4, 5, 9, Wls, vascular endothelial growth factors [VEGFR] 1, 2, 3, Nrp2) and transcription factors (Gata4, Lmo3, Tcfec, Maf) as well as endocytosis‐related (Stabilin‐1/2, Lyve1, and Ehd3) and cytoskeleton‐associated molecules (Rnd3/RhoE). Specific gene induction in cultured LSEC versus freshly isolated LSEC as well as LMEC (Esm‐1, Aatf) and up‐regulation of gene expression to LMEC levels (CXCR4, Apelin) confirmed true transdifferentiation of LSEC in vitro. In addition, our analysis identified a novel 26‐kDa single‐pass transmembrane protein, liver endothelial differentiation‐associated protein (Leda)‐1, that was selectively expressed in all liver endothelial cells and preferentially localized to the abluminal cell surface. Upon forced overexpression in MDCK cells, Leda‐1 was sorted basolaterally to E‐cadherin‐positive adherens junctions, suggesting functional involvement in cell adhesion and polarity. Conclusion: Comparative microvascular analysis in rat identified a hepatic microenvironment‐dependent LSEC‐specific differentiation program including the novel junctional molecule Leda‐1. HEPATOLOGY 2010

Patient preferences for psoriasis treatments: impact of treatment experience.

Background  Patient preferences for psoriasis treatments can impact treatment satisfaction and adherence and may therefore influence clinical outcome.

Macrophage activation in human diseases.

It is becoming increasingly accepted that macrophages play a crucial role in many diseases associated with chronic inflammation, including atherosclerosis, obesity, diabetes, cancer, skin diseases, and even neurodegenerative diseases. It is therefore not surprising that macrophages in human diseases have gained significant interest during the last years. Molecular analysis combined with more sophisticated murine disease models and the application of genome-wide technologies has resulted in a much better understanding of the role of macrophages in human disease. We highlight important gain of knowledge during the last years for tumor-associated macrophages, and for macrophages in atherosclerosis, obesity and wound healing. Albeit these exciting findings certainly pave the way to novel diagnostics and therapeutics, several hurdles still need to be overcome. We propose a general outline for future research and development in disease-related macrophage biology based on integrating (1) genome-wide technologies, (2) direct human sampling, and (3) a dedicated use of in vivo model systems.

Unique cell type-specific junctional complexes in vascular endothelium of human and rat liver sinusoids.

Liver sinusoidal endothelium is strategically positioned to control access of fluids, macromolecules and cells to the liver parenchyma and to serve clearance functions upstream of the hepatocytes. While clearance of macromolecular debris from the peripheral blood is performed by liver sinusoidal endothelial cells (LSECs) using a delicate endocytic receptor system featuring stabilin-1 and -2, the mannose receptor and CD32b, vascular permeability and cell trafficking are controlled by transcellular pores, i.e. the fenestrae, and by intercellular junctional complexes. In contrast to blood vascular and lymphatic endothelial cells in other organs, the junctional complexes of LSECs have not yet been consistently characterized in molecular terms. In a comprehensive analysis, we here show that LSECs express the typical proteins found in endothelial adherens junctions (AJ), i.e. VE-cadherin as well as α-, β-, p120-catenin and plakoglobin. Tight junction (TJ) transmembrane proteins typical of endothelial cells, i.e. claudin-5 and occludin, were not expressed by rat LSECs while heterogenous immunreactivity for claudin-5 was detected in human LSECs. In contrast, junctional molecules preferentially associating with TJ such as JAM-A, B and C and zonula occludens proteins ZO-1 and ZO-2 were readily detected in LSECs. Remarkably, among the JAMs JAM-C was considerably over-expressed in LSECs as compared to lung microvascular endothelial cells. In conclusion, we show here that LSECs form a special kind of mixed-type intercellular junctions characterized by co-occurrence of endothelial AJ proteins, and of ZO-1 and -2, and JAMs. The distinct molecular architecture of the intercellular junctional complexes of LSECs corroborates previous ultrastructural findings and provides the molecular basis for further analyses of the endothelial barrier function of liver sinusoids under pathologic conditions ranging from hepatic inflammation to formation of liver metastasis.

Matching physicians' treatment recommendations to patients' treatment preferences is associated with improvement in treatment satisfaction.

Background  Dissatisfaction with treatment is common among those with psoriasis. While incorporating patients’ preferences into the process of treatment decision‐making may improve satisfaction, this relationship has not been clearly established.

Treatment Satisfaction of Patients with Psoriasis

Treatment satisfaction of patients with psoriasis largely depends on the treatment modality, but evidence on preferences for specific medications is scarce. Here we assessed treatment satisfaction of 200 participants with moderate-to-severe psoriasis from a German University hospital with a 5-point scale and the Treatment Satisfaction Questionnaire for Medication (TSQM) and determined sociodemographic and disease-related influence factors. Participants obtaining biologicals and traditional systemic medications were significantly more satisfied than those receiving phototherapy or topical agents (TSQM = 323.3, 288.0, 260.6 or 266.8; p < 0.001). The highest TSQM score was calculated for ustekinumab (350.1), followed by acitretin (338.1), adalimumab (323.0), fumaric acid esters (304.7), infliximab (300.2), etanercept (298.8), and methotrexate (272.3; p < 0.001). High disease-related quality of life impairment (β = -0.437, p < 0.001) and psoriatic arthritis (β = -0.185, p = 0.005) were associated with decreased satisfaction. Optimising satisfaction is essential to improve adherence and outcome. We show high preferences for biologicals, particularly ustekinumab, but also good satisfaction with certain traditional medications.

Synergistic activation by p38MAPK and glucocorticoid signaling mediates induction of M2-like tumor-associated macrophages expressing the novel CD20 homolog MS4A8A

Tumor‐associated macrophages (TAMs) represent alternatively activated (M2) macrophages that support tumor growth. Previously, we have described a special LYVE‐1+ M2 TAM subset in vitro and in vivo; gene profiling of this TAM subset identified MS4A8A as a novel TAM molecule expressed in vivo by TAM in mammary carcinoma and malignant melanoma. In vitro, Ms4a8a mRNA and MS4A8A protein expression was strongly induced in bone marrow‐derived macrophages (BMDMs) by combining M2 mediators (IL‐4, glucocorticoids) and tumor‐conditioned media (TCM). Admixture of MS4A8A+ TCM/IL‐4/GC‐treated BMDM significantly enhanced the tumor growth rate of subcutaneously transplanted TS/A mammary carcinomas. Upon forced overexpression of MS4A8A, Raw 264.7 macrophage‐like cells displayed a special gene signature. Admixture of these MS4A8A+ Raw 264.7 cells also significantly enhanced the tumor growth rate of subcutaneously transplanted mammary carcinomas. To identify the signaling pathways involved in synergistic induction of MS4A8A, the major signaling cascades with known functions in TAM were analyzed. Although inhibitors of NF‐κB activation and of the MAPK JNK and ERK did not show relevant effects, the p38α/β MAPK inhibitor SB203580 strongly and highly significantly (p > 0.001) inhibited MS4A8A expression on mRNA and protein level. In addition, MS4A8A expression was restricted in M2 BMDM from mice with defective GC receptor (GR) dimerization indicating that classical GR gene regulation is mandatory for MS4A8A induction. In conclusion, expression of MS4A8A within the complex signal integration during macrophage immune responses may act to fine tune gene regulation. Furthermore, MS4A8A+ TAM may serve as a novel cellular target for selective cancer therapy.

Endothelial transdifferentiation in hepatocellular carcinoma: loss of Stabilin-2 expression in peri-tumourous liver correlates with increased survival

Hepatocellular carcinoma (HCC) is a malignant tumour that is characterized by extensive vascular remodelling and responsiveness to treatment with the anti‐angiogenic multikinase inhibitor sorafenib. The aim was to study endothelial remodelling in HCC.

Patient Preferences for Treatment of Psoriasis with Biologicals: A Discrete Choice Experiment

Treatment dissatisfaction and non-adherence are common among patients with psoriasis, partly due to discordance between individual preferences and recommended treatments. However, patients are more satisfied with biologicals than with other treatments. The aim of our study was to assess patient preferences for treatment of psoriasis with biologicals by using computer-based conjoint analysis. Biologicals approved for psoriasis in Germany were decomposed into outcome (probability of 50% and 90% improvement, time until response, sustainability of success, probability of mild and severe adverse events (AE), probability of American College of Rheumatology (ACR) 20 response) and process attributes (treatment location, frequency, duration and delivery method). Impact of sociodemographic and socioeconomic characteristics and disease severity on Relative Importance Scores (RIS) of each attribute was assessed with analyses of variance, post hoc tests, and multivariate regression. Averaged across the cohort of 200 participants with moderate-to-severe psoriasis, preferences were highest for avoiding severe AE (RIS = 17.3), followed by 90% improvement (RIS = 14.0) and avoiding mild AE (RIS = 10.5). Process attributes reached intermediate RIS (8.2–8.8). Men were more concerned about efficacy than women (50% improvement: RIS = 6.9 vs. 9.5, p = 0.008; β = -0.191, p = 0.011 in multivariate models; 90% improvement: RIS = 12.1 vs. 15.4, p = 0.002; β = -0.197, p = 0.009). Older participants judged the probability of 50% and 90% improvement less relevant than younger ones (50% improvement: Pearson’s Correlation (PC) = -0.161, p = 0.022; β = -0.219, p = 0.017; 90% improvement: PC = -0.155, p = 0.028; β = -0.264, p = 0.004) but worried more about severe AE (PC = 0.175, p = 0.013; β = 0.166, p = 0.082). In summary, participants with moderate-to-severe psoriasis were most interested in safety of biologicals, followed by efficacy, but preferences varied with sociodemographic characteristics and working status. Based on this knowledge, physicians should identify preferences of each individual patient during shared decision-making in order to optimize treatment satisfaction, adherence and outcome.