Identification of CRTH2 as a New PPARγ-Target Gene in T Cells Suggested CRTH2 Dependent Conversion of T2 Cells as Therapeutic Concept in COVID-19 Infection.

Background: COVID-19 is a serious viral infection, which is often associated with a lethal outcome. Therefore, understanding mechanisms, which affect the immune response during SARS-CoV2 infection, are important.

Methods: To address this, we determined the number of T cells in peripheral blood derived from intensive care COVID-19 patients.

Selective red blood cell depletion by apheresis in sheep causes severe normovolemic anemia.

Background: The setting of normovolemic anemia is required for a variety of research applications, such as testing of novel medication for anemia treatment. Unfortunately, large animal models using full blood draw and replenishment with balanced electrolyte solution (BES) lead to bleeding complications, as coagulation factors and platelets are also drawn. We therefore aimed to establish a model of selective red blood cell (RBC) depletion to the main endpoint of hemoglobin (Hgb) levels of 4-6 g dL using apheresis in sheep.

Hemojuvelin-mediated hepcidin induction requires both bone morphogenetic protein type I receptors ALK2 and ALK3.

Hemojuvelin (HJV) is a glycosylphosphatidylinositol-anchored protein of the repulsive guidance molecule family acting as a bone morphogenetic protein (BMP) coreceptor to induce the hepatic iron regulatory protein hepcidin. Hepcidin causes ubiquitination and degradation of the sole known iron exporter ferroportin, thereby limiting iron availability. The detailed signaling mechanism of HJV in vivo has yet to be investigated.

Association between spatial distribution of leukocyte subsets and clinical presentation of head and neck squamous cell carcinoma.

Background: Interactions between tumor cells and cells in the microenvironment contribute to tumor development and metastasis. The spatial arrangement of individual cells in relation to each other influences the likelihood of whether and how these cells interact with each other.

Methods: This study investigated the effect of spatial distribution on the function of leukocyte subsets in the microenvironment of human head and neck squamous cell carcinoma (HNSCC) using multiplex immunohistochemistry (IHC).

EVIDENCE FROM FATAL COVID-19 FOR TARGETING THE BRADYKININ METABOLISM-A SINGLE-CENTER COHORT STUDY.

Background: Severe progression of COVID-19 to critical illness, with pulmonary failure, multiple organ failure, and death, is driven by systemic inflammatory responses with overproduction of inflammatory cytokines. In the past years, the potential role of bradykinin, leading to inappropriate immune responses in the pathogenesis of COVID-19, has been raised in a so-called bradykinin storm. However, clinical investigations of bradykinin, its metabolite des-Arg 9 -bradykinin, or substance P, are rare or completely lacking during intensive care of COVID-19 patients.

HIGH HEPARANASE LEVEL IN SURVIVORS OF COVID-19 - INDICATOR OF VASCULAR AND PULMONARY RECOVERY?

Background: Severe progression of coronavirus disease 2019 (COVID-19) causes respiratory failure and critical illness. Recently, COVID-19 has been associated with heparanase (HPSE)-induced endothelial barrier dysfunction and inflammation, so called endothelitis, and therapeutic treatment with heparin or low-molecular-weight heparin (LMWH) targeting HPSE has been postulated. Because, up to this date, clinicians are unable to measure the severity of endothelitis, which can lead to multiorgan failure and concomitant death, we investigated plasma levels of HPSE and heparin-binding protein (HBP) in COVID-19 intensive care patients to render a possible link between endothelitis and these plasma parameters.

Cross-talk between red blood cells and plasma influences blood flow and omics phenotypes in severe COVID-19.

Coronavirus disease 2019 (COVID-19) is caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and can affect multiple organs, among which is the circulatory system. Inflammation and mortality risk markers were previously detected in COVID-19 plasma and red blood cells (RBCs) metabolic and proteomic profiles. Additionally, biophysical properties, such as deformability, were found to be changed during the infection.

RELSA-A multidimensional procedure for the comparative assessment of well-being and the quantitative determination of severity in experimental procedures.

Good science in translational research requires good animal welfare according to the principles of 3Rs. In many countries, determining animal welfare is a mandatory legal requirement, implying a categorization of animal suffering, traditionally dominated by subjective scorings. However, how such methods can be objectified and refined to compare impairments between animals, subgroups, and animal models remained unclear.

Phosphatidylserine Synthase PTDSS1 Shapes the Tumor Lipidome to Maintain Tumor-Promoting Inflammation.

Unlabelled: An altered lipidome in tumors may affect not only tumor cells themselves but also their microenvironment. In this study, a lipidomics screen reveals increased amounts of phosphatidylserine (PS), particularly ether-PS (ePS), in murine mammary tumors compared with normal tissue. PS was produced by phosphatidylserine synthase 1 (PTDSS1), and depletion of Ptdss1 from tumor cells in mice reduced ePS levels accompanied by stunted tumor growth and decreased tumor-associated macrophage (TAM) abundance.

Antioxidants as Therapeutic Agents in Acute Respiratory Distress Syndrome (ARDS) Treatment-From Mice to Men.

Acute respiratory distress syndrome (ARDS) is a major cause of patient mortality in intensive care units (ICUs) worldwide. Considering that no causative treatment but only symptomatic care is available, it is obvious that there is a high unmet medical need for a new therapeutic concept. One reason for a missing etiologic therapy strategy is the multifactorial origin of ARDS, which leads to a large heterogeneity of patients.

Nrf2-A Molecular Target for Sepsis Patients in Critical Care.

The transcription factor NF-E2 p45-related factor 2 (Nrf2) is an established master regulator of the anti-oxidative and detoxifying cellular response. Thus, a role in inflammatory diseases associated with the generation of large amounts of reactive oxygen species (ROS) seems obvious. In line with this, data obtained in cell culture experiments and preclinical settings have shown that Nrf2 is important in regulating target genes that are necessary to ensure cellular redox balance.

Macrophage-Derived Iron-Bound Lipocalin-2 Correlates with Renal Recovery Markers Following Sepsis-Induced Kidney Damage.

During the course of sepsis in critically ill patients, kidney dysfunction and damage are among the first events of a complex scenario toward multi-organ failure and patient death. Acute kidney injury triggers the release of lipocalin-2 (Lcn-2), which is involved in both renal injury and recovery. Taking into account that Lcn-2 binds and transports iron with high affinity, we aimed at clarifying if Lcn-2 fulfills different biological functions according to its iron-loading status and its cellular source during sepsis-induced kidney failure.

Redox Regulation of PPAR in Polarized Macrophages.

The peroxisome proliferator-activated receptor (PPAR) is a central mediator of cellular lipid metabolism and immune cell responses during inflammation. This is facilitated by its role as a transcription factor as well as a DNA-independent protein interaction partner. We addressed how the cellular redox milieu in the cytosol and the nucleus of lipopolysaccharide (LPS)/interferon-- (IFN-) and interleukin-4- (IL4-) polarized macrophages (M) initiates posttranslational modifications of PPAR, that in turn alter its protein function.

Histone Deacetylation Inhibitors as Modulators of Regulatory T Cells.

Regulatory T cells (T) are important mediators of immunological self-tolerance and homeostasis. Being cluster of differentiation 4Forkhead box protein3 (CD4FOXP3), these cells are a subset of CD4 T lymphocytes and can originate from the thymus (tT) or from the periphery (pT). The malfunction of CD4 T is associated with autoimmune responses such as rheumatoid arthritis (RA), multiple sclerosis (MS), type 1 diabetes (T1D), inflammatory bowel diseases (IBD), psoriasis, systemic lupus erythematosus (SLE), and transplant rejection.

Structure optimization of a new class of PPARγ antagonists.

Peroxisome proliferator-activated receptor gamma (PPARγ) modulators have found wide application for the treatment of cancers, metabolic disorders and inflammatory diseases. Contrary to PPARγ agonists, PPARγ antagonists have been much less studied and although they have shown immunomodulatory effects, there is still no therapeutically useful PPARγ antagonist on the market. In contrast to non-competitive, irreversible inhibition caused by 2-chloro-5-nitrobenzanilide (GW9662), the recently described (E)-2-(5-((4-methoxy-2-(trifluoromethyl)quinolin-6-yl)methoxy)-2-((4-(trifluoromethyl)benzyl)oxy)-benzylidene)-hexanoic acid (MTTB, T-10017) is a promising prototype for a new class of PPARγ antagonists.

Flow cytometry-based FRET identifies binding intensities in PPARγ1 protein-protein interactions in living cells.

PPARγ is a pharmacological target in inflammatory and metabolic diseases. Upon agonistic treatment or following antagonism, binding of co-factors is altered, which consequently affects PPARγ-dependent transactivation as well as its DNA-independent properties. Therefore, establishing techniques to characterize these interactions is an important issue in living cells.

Macrophage S1PR1 Signaling Alters Angiogenesis and Lymphangiogenesis During Skin Inflammation.

The bioactive lipid sphingosine-1-phosphate (S1P), along with its receptors, modulates lymphocyte trafficking and immune responses to regulate skin inflammation. Macrophages are important in the pathogenesis of psoriasiform skin inflammation and express various S1P receptors. How they respond to S1P in skin inflammation remains unknown.

Sphingosine kinase 2 is a negative regulator of inflammatory macrophage activation.

Sphingosine kinases (SPHK) generate the sphingolipid sphingosine-1-phosphate, which, among other functions, is a potent regulator of inflammation. While SPHK1 produces S1P to promote inflammatory signaling, the role of SPHK2 is unclear due to divergent findings in studies utilizing gene depletion versus inhibition of catalytic activity. We sought to clarify how SPHK2 affects inflammatory signaling in human macrophages, which are main regulators of inflammation.

Tolerizing CTL by Sustained Hepatic PD-L1 Expression Provides a New Therapy Approach in Mouse Sepsis.

Cytotoxic T lymphocyte (CTL) activation contributes to liver damage during sepsis, but the mechanisms involved are largely unknown. Understanding the underlying principle will permit interference with CTL activation and thus, provide a new therapeutic option. To elucidate the mechanism leading to CTL activation we used the Hepa1-6 cell line and the mouse model of polymicrobial sepsis, following cecal-ligation and -puncture (CLP) in wildtype, myeloid specific NOX-2, global NOX2 and NOX4 knockout mice, and their survival as a final readout.

Shooting three inflammatory targets with a single bullet: Novel multi-targeting anti-inflammatory glitazones.

In search for effective multi-targeting drug ligands (MTDLs) to address low-grade inflammatory changes of metabolic disorders, we rationally designed some novel glitazones-like compounds. This was achieved by incorporating prominent pharmacophoric motifs from previously reported COX-2, 15-LOX and PPARγ ligands. Challenging our design with pre-synthetic docking experiments on PPARγ showed encouraging results.

Histone Deacetylation Inhibitors as Therapy Concept in Sepsis.

Sepsis is characterized by dysregulated gene expression, provoking a hyper-inflammatory response occurring in parallel to a hypo-inflammatory reaction. This is often associated with multi-organ failure, leading to the patient's death. Therefore, reprogramming of these pro- and anti-inflammatory, as well as immune-response genes which are involved in acute systemic inflammation, is a therapy approach to prevent organ failure and to improve sepsis outcomes.