@article{BeckmannSchumacherKleuseretal.2021, author = {Beckmann, Nadine and Schumacher, Fabian and Kleuser, Burkhard and Gulbins, Erich and Nomellini, Vanessa and Caldwell, Charles C.}, title = {Burn injury impairs neutrophil chemotaxis through increased ceramide}, series = {Shock : injury, inflammation, and sepsis, laboratory and clinical approaches}, volume = {56}, journal = {Shock : injury, inflammation, and sepsis, laboratory and clinical approaches}, number = {1}, publisher = {Lippincott Williams \& Wilkins}, address = {Hagerstown, Md.}, issn = {1073-2322}, doi = {10.1097/SHK.0000000000001693}, pages = {125 -- 132}, year = {2021}, abstract = {Infection is a common and often deadly complication after burn injury. A major underlying factor is burn-induced immune dysfunction, particularly with respect to neutrophils as the primary responders to infection. Temporally after murine scald injury, we demonstrate impaired bone marrow neutrophil chemotaxis toward CXCL1 ex vivo. Additionally, we observed a reduced recruitment of neutrophils to the peritoneal after elicitation 7 days after injury. We demonstrate that neutrophil ceramide levels increase after burn injury, and this is associated with decreased expression of CXCR2 and blunted chemotaxis. A major signaling event upon CXCR2 activation is Akt phosphorylation and this was reduced when ceramide was elevated. In contrast, PTEN levels were elevated and PTEN-inhibition elevated phospho-Akt levels and mitigated the burn-induced neutrophil chemotaxis defect. Altogether, this study identifies a newly described pathway of ceramide-mediated suppression of neutrophil chemotaxis after burn injury and introduces potential targets to mitigate this defect and reduce infection-related morbidity and mortality after burn.}, language = {en} } @article{BeckmannKadowSchumacheretal.2018, author = {Beckmann, Nadine and Kadow, Stephanie and Schumacher, Fabian and Goethert, Joachim R. and Kesper, Stefanie and Draeger, Annette and Schulz-Schaeffer, Walter J. and Wang, Jiang and Becker, Jan U. and Kramer, Melanie and Kuehn, Claudine and Kleuser, Burkhard and Becker, Katrin Anne and Gulbins, Erich and Carpinteiro, Alexander}, title = {Pathological manifestations of Farber disease in a new mouse model}, series = {Biological chemistry}, volume = {399}, journal = {Biological chemistry}, number = {10}, publisher = {De Gruyter}, address = {Berlin}, issn = {1431-6730}, doi = {10.1515/hsz-2018-0170}, pages = {1183 -- 1202}, year = {2018}, abstract = {Farber disease (FD) is a rare lysosomal storage disorder resulting from acid ceramidase deficiency and subsequent ceramide accumulation. No treatments are clinically available and affected patients have a severely shortened lifespan. Due to the low incidence, the pathogenesis of FD is still poorly understood. Here, we report a novel acid ceramidase mutant mouse model that enables the study of pathogenic mechanisms of FD and ceramide accumulation. Asah1(tmEx1) mice were generated by deletion of the acid ceramidase signal peptide sequence. The effects on lysosomal targeting and activity of the enzyme were assessed. Ceramide and sphingomyelin levels were quantified by liquid chromatography tandem-mass spectrometry (LC-MS/MS) and disease manifestations in several organ systems were analyzed by histology and biochemistry. We show that deletion of the signal peptide sequence disrupts lysosomal targeting and enzyme activity, resulting in ceramide and sphingomyelin accumulation. The affected mice fail to thrive and die early. Histiocytic infiltrations were observed in many tissues, as well as lung inflammation, liver fibrosis, muscular disease manifestations and mild kidney injury. Our new mouse model mirrors human FD and thus offers further insights into the pathogenesis of this disease. In the future, it may also facilitate the development of urgently needed therapies.}, language = {en} } @article{MorrisKassamBerczetal.2019, author = {Morris, Mackenzie C. and Kassam, Farzaan and Bercz, Aron and Beckmann, Nadine and Schumacher, Fabian and Gulbins, Erich and Makley, Amy T. and Goodman, Michael D.}, title = {The Role of Chemoprophylactic Agents in Modulating Platelet Aggregability After Traumatic Brain Injury}, series = {Journal of surgical research}, volume = {244}, journal = {Journal of surgical research}, publisher = {Elsevier}, address = {San Diego}, issn = {0022-4804}, doi = {10.1016/j.jss.2019.06.022}, pages = {1 -- 8}, year = {2019}, abstract = {Background: The pathophysiology behind the subacute but persistent hypercoagulable state after traumatic brain injury (TBI) is poorly understood but contributes to morbidity induced by venous thromboembolism. Because platelets and their microvesicles have been hypothesized to play a role in post-traumatic hypercoagulability, administration of commonly used agents may ameliorate this coagulability. We hypothesized that utilization of aspirin, ketorolac, amitriptyline, unfractionated heparin, or enoxaparin would modulate the platelet aggregation response after TBI. Methods: Concussive TBI was induced by weight drop. Mice were then randomized to receive aspirin, ketorolac, amitriptyline, heparin, enoxaparin, or saline control at 2 and 8 h after TBI. Mice were sacrificed at 6 or 24 h after injury to determine coagulability by rotational thromboelastometry (ROTEM), platelet function testing with impedance aggregometry, and microvesicle enumeration. Platelet sphingolipid metabolites were analyzed by mass spectrometry. Results: ROTEM demonstrated increased platelet contribution to maximum clot firmness at 6 h after TBI in mice that received aspirin or amitriptyline, but this did not persist at 24 h. By contrast, adenosine diphosphate- and arachidonic acid-induced platelet aggregation at 6 h was significantly lower in mice receiving ketorolac, aspirin, and amitriptyline compared with mice receiving saline at 6 h after injury and only arachidonic acid-initiated platelet aggregation was decreased by aspirin at 24 h. There were no differences in microvesicle production at either time point. Platelet sphingosine-1-phosphate levels were decreased at 6 h in the group receiving amitriptyline and increased at 24 h along with platelet ceramide levels at 24 h in the amitriptyline group. Conclusion: After TBI, amitriptyline decreased platelet aggregability and increased contribution to clot in a manner similar to aspirin. The amitriptyline effects on platelet function and sphingolipid metabolites may represent a possible role of the acid sphingomyelinase in the hypercoagulability observed after injury. In addition, inhibition of platelet reactivity may be an underappreciated benefit of low molecular weight heparins, such as enoxaparin. (C) 2019 Elsevier Inc. All rights reserved.}, language = {en} } @article{BeckmannBeckerKadowetal.2019, author = {Beckmann, Nadine and Becker, Katrin Anne and Kadow, Stephanie and Schumacher, Fabian and Kramer, Melanie and Kuehn, Claudine and Schulz-Schaeffer, Walter J. and Edwards, Michael J. and Kleuser, Burkhard and Gulbins, Erich and Carpinteiro, Alexander}, title = {Acid Sphingomyelinase Deficiency Ameliorates Farber Disease}, series = {International journal of molecular sciences}, volume = {20}, journal = {International journal of molecular sciences}, number = {24}, publisher = {MDPI}, address = {Basel}, issn = {1422-0067}, doi = {10.3390/ijms20246253}, pages = {18}, year = {2019}, abstract = {Farber disease is a rare lysosomal storage disorder resulting from acid ceramidase deficiency and subsequent ceramide accumulation. No treatments for Farber disease are clinically available, and affected patients have a severely shortened lifespan. We have recently reported a novel acid ceramidase deficiency model that mirrors the human disease closely. Acid sphingomyelinase is the enzyme that generates ceramide upstream of acid ceramidase in the lysosomes. Using our acid ceramidase deficiency model, we tested if acid sphingomyelinase could be a potential novel therapeutic target for the treatment of Farber disease. A number of functional acid sphingomyelinase inhibitors are clinically available and have been used for decades to treat major depression. Using these as a therapeutic for Farber disease, thus, has the potential to improve central nervous symptoms of the disease as well, something all other treatment options for Farber disease can't achieve so far. As a proof-of-concept study, we first cross-bred acid ceramidase deficient mice with acid sphingomyelinase deficient mice in order to prevent ceramide accumulation. Double-deficient mice had reduced ceramide accumulation, fewer disease manifestations, and prolonged survival. We next targeted acid sphingomyelinase pharmacologically, to test if these findings would translate to a setting with clinical applicability. Surprisingly, the treatment of acid ceramidase deficient mice with the acid sphingomyelinase inhibitor amitriptyline was toxic to acid ceramidase deficient mice and killed them within a few days of treatment. In conclusion, our study provides the first proof-of-concept that acid sphingomyelinase could be a potential new therapeutic target for Farber disease to reduce disease manifestations and prolong survival. However, we also identified previously unknown toxicity of the functional acid sphingomyelinase inhibitor amitriptyline in the context of Farber disease, strongly cautioning against the use of this substance class for Farber disease patients.}, language = {en} }