Publications by authors named "Christoph Reinhardt"

70 Publications

Sex differences in Lemierre syndrome: Individual patient-level analysis.

Thromb Res 2021 Mar 6;202:36-39. Epub 2021 Mar 6.

Center for Thrombosis and Hemostasis, University Medical Center Mainz, Mainz, Germany; Clinic of Angiology, University Hospital Zurich, Zurich, Switzerland. Electronic address:

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http://dx.doi.org/10.1016/j.thromres.2021.03.002DOI Listing
March 2021

IL-17 controls central nervous system autoimmunity through the intestinal microbiome.

Sci Immunol 2021 Feb;6(56)

Institute for Molecular Medicine, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany.

Interleukin-17A- (IL-17A) and IL-17F-producing CD4 T helper cells (T17 cells) are implicated in the development of chronic inflammatory diseases, such as multiple sclerosis and its animal model, experimental autoimmune encephalomyelitis (EAE). T17 cells also orchestrate leukocyte invasion of the central nervous system (CNS) and subsequent tissue damage. However, the role of IL-17A and IL-17F as effector cytokines is still confused with the encephalitogenic function of the cells that produce these cytokines, namely, T17 cells, fueling a long-standing debate in the neuroimmunology field. Here, we demonstrated that mice deficient for IL-17A/F lose their susceptibility to EAE, which correlated with an altered composition of their gut microbiota. However, loss of IL-17A/F in T cells did not diminish their encephalitogenic capacity. Reconstitution of a wild-type-like intestinal microbiota or reintroduction of IL-17A specifically into the gut epithelium of IL-17A/F-deficient mice reestablished their susceptibility to EAE. Thus, our data demonstrated that IL-17A and IL-17F are not encephalitogenic mediators but rather modulators of intestinal homeostasis that indirectly alter CNS-directed autoimmunity.
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http://dx.doi.org/10.1126/sciimmunol.aaz6563DOI Listing
February 2021

Response by Ascher et al to Letter Regarding Article, "Gut Microbiota Restricts NETosis in Acute Mesenteric Ischemia-Reperfusion Injury".

Arterioscler Thromb Vasc Biol 2021 01 23;41(1):e74-e75. Epub 2020 Dec 23.

Center for Thrombosis and Hemostasis, University Medical Center of the Johannes Gutenberg-University of Mainz (S.A., E.W., G.P., K.K., F.M., M.B., K.J., C.R.), Johannes Gutenberg University of Mainz, Germany.

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http://dx.doi.org/10.1161/ATVBAHA.120.315541DOI Listing
January 2021

Co-option of Neutrophil Fates by Tissue Environments.

Cell 2020 Nov 23;183(5):1282-1297.e18. Epub 2020 Oct 23.

Area of Cell & Developmental Biology, Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid 28029, Spain; Institute for Cardiovascular Prevention (IPEK), Ludwig-Maximillians-Universitat, Munich 80802, Germany. Electronic address:

Classically considered short-lived and purely defensive leukocytes, neutrophils are unique in their fast and moldable response to stimulation. This plastic behavior may underlie variable and even antagonistic functions during inflammation or cancer, yet the full spectrum of neutrophil properties as they enter healthy tissues remains unexplored. Using a new model to track neutrophil fates, we found short but variable lifetimes across multiple tissues. Through analysis of the receptor, transcriptional, and chromatin accessibility landscapes, we identify varying neutrophil states and assign non-canonical functions, including vascular repair and hematopoietic homeostasis. Accordingly, depletion of neutrophils compromised angiogenesis during early age, genotoxic injury, and viral infection, and impaired hematopoietic recovery after irradiation. Neutrophils acquired these properties in target tissues, a process that, in the lungs, occurred in CXCL12-rich areas and relied on CXCR4. Our results reveal that tissues co-opt neutrophils en route for elimination to induce programs that support their physiological demands.
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http://dx.doi.org/10.1016/j.cell.2020.10.003DOI Listing
November 2020

The Commensal Microbiota Enhances ADP-Triggered Integrin αβ Activation and von Willebrand Factor-Mediated Platelet Deposition to Type I Collagen.

Int J Mol Sci 2020 Sep 28;21(19). Epub 2020 Sep 28.

Center for Thrombosis and Hemostasis (CTH), University Medical Center of the Johannes Gutenberg- University of Mainz, Langenbeckstrasse 1, 55131 Mainz, Germany.

The commensal microbiota is a recognized enhancer of arterial thrombus growth. While several studies have demonstrated the prothrombotic role of the gut microbiota, the molecular mechanisms promoting arterial thrombus growth are still under debate. Here, we demonstrate that germ-free (GF) mice, which from birth lack colonization with a gut microbiota, show diminished static deposition of washed platelets to type I collagen compared with their conventionally raised (CONV-R) counterparts. Flow cytometry experiments revealed that platelets from GF mice show diminished activation of the integrin αβ (glycoprotein IIbIIIa) when activated by the platelet agonist adenosine diphosphate (ADP). Furthermore, washed platelets from Toll-like receptor-2 ()-deficient mice likewise showed impaired static deposition to the subendothelial matrix component type I collagen compared with wild-type (WT) controls, a process that was unaffected by GPIbα-blockade but influenced by von Willebrand factor (VWF) plasma levels. Collectively, our results indicate that microbiota-triggered steady-state activation of innate immune pathways via TLR2 enhances platelet deposition to subendothelial matrix molecules. Our results link host colonization status with the ADP-triggered activation of integrin αβ, a pathway promoting platelet deposition to the growing thrombus.
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http://dx.doi.org/10.3390/ijms21197171DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7583822PMC
September 2020

Bacterial polyphosphates interfere with the innate host defense to infection.

Nat Commun 2020 08 12;11(1):4035. Epub 2020 Aug 12.

Center for Thrombosis and Hemostasis, University Medical Center Mainz, 55131, Mainz, Germany.

Polyphosphates are linear polymers and ubiquitous metabolites. Bacterial polyphosphates are long chains of hundreds of phosphate units. Here, we report that mouse survival of peritoneal Escherichia coli sepsis is compromised by long-chain polyphosphates, and improves with bacterial polyphosphatekinase deficiency or neutralization using recombinant exopolyphosphatase. Polyphosphate activities are chain-length dependent, impair pathogen clearance, antagonize phagocyte recruitment, diminish phagocytosis and decrease production of iNOS and cytokines. Macrophages bind and internalize polyphosphates, in which their effects are independent of P2Y1 and RAGE receptors. The M1 polarization driven by E. coli derived LPS is misdirected by polyphosphates in favor of an M2 resembling phenotype. Long-chain polyphosphates modulate the expression of more than 1800 LPS/TLR4-regulated genes in macrophages. This interference includes suppression of hundreds of type I interferon-regulated genes due to lower interferon production and responsiveness, blunted STAT1 phosphorylation and reduced MHCII expression. In conclusion, prokaryotic polyphosphates disturb multiple macrophage functions for evading host immunity.
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http://dx.doi.org/10.1038/s41467-020-17639-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7423913PMC
August 2020

Gut Microbiota Restricts NETosis in Acute Mesenteric Ischemia-Reperfusion Injury.

Arterioscler Thromb Vasc Biol 2020 09 2;40(9):2279-2292. Epub 2020 Jul 2.

From the Center for Thrombosis and Hemostasis (CTH), University Medical Center of the Johannes Gutenberg University of Mainz (JGU), Germany (S.A., E.W., G.P., H.F., F.B., M.M., F.M., A.G., M.B., M.S., I.B., K.G., K.K., K.J., C.R.).

Objective: Recruitment of neutrophils and formation of neutrophil extracellular traps (NETs) contribute to lethality in acute mesenteric infarction. To study the impact of the gut microbiota in acute mesenteric infarction, we used gnotobiotic mouse models to investigate whether gut commensals prime the reactivity of neutrophils towards formation of neutrophil extracellular traps (NETosis). Approach and Results: We applied a mesenteric ischemia-reperfusion (I/R) injury model to germ-free (GF) and colonized C57BL/6J mice. By intravital imaging, we quantified leukocyte adherence and NET formation in I/R-injured mesenteric venules. Colonization with gut microbiota or monocolonization with augmented the adhesion of leukocytes, which was dependent on the TLR4 (Toll-like receptor-4)/TRIF (TIR-domain-containing adapter-inducing interferon-β) pathway. Although neutrophil accumulation was decreased in I/R-injured venules of GF mice, NETosis following I/R injury was significantly enhanced compared with conventionally raised mice or mice colonized with the minimal microbial consortium altered Schaedler flora. Also ex vivo, neutrophils from GF and antibiotic-treated mice showed increased LPS (lipopolysaccharide)-induced NETosis. Enhanced TLR4 signaling in GF neutrophils was due to elevated TLR4 expression and augmented IRF3 (interferon regulatory factor-3) phosphorylation. Likewise, neutrophils from antibiotic-treated conventionally raised mice had increased NET formation before and after ischemia. Increased NETosis in I/R injury was abolished in conventionally raised mice deficient in the TLR adaptor TRIF. In support of the desensitizing influence of enteric LPS, treatment of GF mice with LPS via drinking water diminished LPS-induced NETosis in vitro and in the mesenteric I/R injury model.

Conclusions: Collectively, our results identified that the gut microbiota suppresses NETing neutrophil hyperreactivity in mesenteric I/R injury, while ensuring immunovigilance by enhancing neutrophil recruitment.
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http://dx.doi.org/10.1161/ATVBAHA.120.314491DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7484055PMC
September 2020

Germ-free housing conditions do not affect aortic root and aortic arch lesion size of late atherosclerotic low-density lipoprotein receptor-deficient mice.

Gut Microbes 2020 11 24;11(6):1809-1823. Epub 2020 Jun 24.

Center for Thrombosis and Hemostasis (CTH), University Medical Center Mainz , Mainz, Germany.

The microbiota has been linked to the development of atherosclerosis, but the functional impact of these resident bacteria on the lesion size and cellular composition of atherosclerotic plaques in the aorta has never been experimentally addressed with the germ-free low-density lipoprotein receptor-deficient ( ) mouse atherosclerosis model. Here, we report that 16 weeks of high-fat diet (HFD) feeding of hypercholesterolemic mice at germ-free (GF) housing conditions did not impact relative aortic root plaque size, macrophage content, and necrotic core area. Likewise, we did not find changes in the relative aortic arch lesion size. However, late atherosclerotic GF mice had altered inflammatory plasma protein markers and reduced smooth muscle cell content in their atherosclerotic root plaques relative to CONV-R mice. Neither absolute nor relative aortic root or aortic arch plaque size correlated with age. Our analyses on GF mice did not reveal a significant contribution of the microbiota in late aortic atherosclerosis.
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http://dx.doi.org/10.1080/19490976.2020.1767463DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7524356PMC
November 2020

Microbiota-Induced Type I Interferons Instruct a Poised Basal State of Dendritic Cells.

Cell 2020 05 6;181(5):1080-1096.e19. Epub 2020 May 6.

Institute of Immunology, University Medical Center Mainz, Langenbeckstrasse 1, 55131 Mainz, Germany; Research Centre for Immunotherapy, University Medical Center Mainz, Langenbeckstraße 1, 55131 Mainz, Germany. Electronic address:

Environmental signals shape host physiology and fitness. Microbiota-derived cues are required to program conventional dendritic cells (cDCs) during the steady state so that they can promptly respond and initiate adaptive immune responses when encountering pathogens. However, the molecular underpinnings of microbiota-guided instructive programs are not well understood. Here, we report that the indigenous microbiota controls constitutive production of type I interferons (IFN-I) by plasmacytoid DCs. Using genome-wide analysis of transcriptional and epigenetic regulomes of cDCs from germ-free and IFN-I receptor (IFNAR)-deficient mice, we found that tonic IFNAR signaling instructs a specific epigenomic and metabolic basal state that poises cDCs for future pathogen combat. However, such beneficial biological function comes with a trade-off. Instructed cDCs can prime T cell responses against harmless peripheral antigens when removing roadblocks of peripheral tolerance. Our data provide fresh insights into the evolutionary trade-offs that come with successful adaptation of vertebrates to their microbial environment.
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http://dx.doi.org/10.1016/j.cell.2020.04.022DOI Listing
May 2020

Physiological Roles of the von Willebrand Factor-Factor VIII Interaction.

Subcell Biochem 2020 ;94:437-464

Center for Thrombosis and Hemostasis (CTH), University Medical Center Mainz, Langenbeckstrasse 1, Building 708, 55131, Mainz, Germany.

Von Willebrand factor (VWF) and coagulation factor VIII (FVIII) circulate as a complex in plasma and have a major role in the hemostatic system. VWF has a dual role in hemostasis. It promotes platelet adhesion by anchoring the platelets to the subendothelial matrix of damaged vessels and it protects FVIII from proteolytic degradation. Moreover, VWF is an acute phase protein that has multiple roles in vascular inflammation and is massively secreted from Weibel-Palade bodies upon endothelial cell activation. Activated FVIII on the other hand, together with coagulation factor IX forms the tenase complex, an essential feature of the propagation phase of coagulation on the surface of activated platelets. VWF deficiency, either quantitative or qualitative, results in von Willebrand disease (VWD), the most common bleeding disorder. The deficiency of FVIII is responsible for Hemophilia A, an X-linked bleeding disorder. Here, we provide an overview on the role of the VWF-FVIII interaction in vascular physiology.
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http://dx.doi.org/10.1007/978-3-030-41769-7_18DOI Listing
April 2020

α-Linolenic Acid-Rich Diet Influences Microbiota Composition and Villus Morphology of the Mouse Small Intestine.

Nutrients 2020 Mar 11;12(3). Epub 2020 Mar 11.

Center for Thrombosis and Hemostasis (CTH), University Medical Center Mainz, Johannes Gutenberg-University Mainz, Langenbeckstrasse 1, 55131 Mainz, Germany.

α-Linolenic acid (ALA) is well-known for its anti-inflammatory activity. In contrast, the influence of an ALA-rich diet on intestinal microbiota composition and its impact on small intestine morphology are not fully understood. In the current study, we kept adult C57BL/6J mice for 4 weeks on an ALA-rich or control diet. Characterization of the microbial composition of the small intestine revealed that the ALA diet was associated with an enrichment in and . In contrast, taxa belonging to the Firmicutes phylum, including , cluster XIVa, Lachnospiraceae and , had significantly lower abundance compared to control diet. Metagenome prediction indicated an enrichment in functional pathways such as bacterial secretion system in the ALA group, whereas the two-component system and ALA metabolism pathways were downregulated. We also observed increased levels of ALA and its metabolites eicosapentanoic and docosahexanoic acid, but reduced levels of arachidonic acid in the intestinal tissue of ALA-fed mice. Furthermore, intestinal morphology in the ALA group was characterized by elongated villus structures with increased counts of epithelial cells and reduced epithelial proliferation rate. Interestingly, the ALA diet reduced relative goblet and Paneth cell counts. Of note, high-fat Western-type diet feeding resulted in a comparable adaptation of the small intestine. Collectively, our study demonstrates the impact of ALA on the gut microbiome and reveals the nutritional regulation of gut morphology.
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http://dx.doi.org/10.3390/nu12030732DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7146139PMC
March 2020

A holobiont view on thrombosis: unravelling the microbiota's influence on arterial thrombus growth.

Microb Cell 2020 Jan 2;7(1):28-31. Epub 2020 Jan 2.

Center for Thrombosis and Hemostasis (CTH), University Medical Center Mainz, Johannes Gutenberg University of Mainz, Langenbeckstrasse 1, 55131 Mainz, Germany.

The commensal microbiota has co-evolved with its host, colonizing all body surfaces. Therefore, this microbial ecosystem is intertwined with host physiology at multiple levels. While it is evident that microbes that reach the blood stream can trigger thrombus formation, it remains poorly explored if the wealth of microbes that colonize the body surfaces of the mammalian host can be regarded as a modifier of cardiovascular disease (CVD) development. To experimentally address the microbiota's role in the development of atherosclerotic lesions and arterial thrombosis, we generated a germ-free (GF) low-density lipoprotein receptor-deficient ( ) atherosclerosis mouse model (Kiouptsi et al., mBio, 2019) and explored the role of nutritional composition on arterial thrombogenesis.
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http://dx.doi.org/10.15698/mic2020.01.704DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6946017PMC
January 2020

The Gut Microbiota in Cardiovascular Disease and Arterial Thrombosis.

Microorganisms 2019 Dec 13;7(12). Epub 2019 Dec 13.

Center for Thrombosis and Hemostasis (CTH), University Medical Center Mainz, Johannes Gutenberg University of Mainz, Langenbeckstrasse 1, 55131 Mainz, Germany.

The gut microbiota has emerged as a contributing factor in the development of atherosclerosis and arterial thrombosis. Metabolites from the gut microbiota, such as trimethylamine N-oxide and short chain fatty acids, were identified as messengers that induce cell type-specific signaling mechanisms and immune reactions in the host vasculature, impacting the development of cardiovascular diseases. In addition, microbial-associated molecular patterns drive atherogenesis and the microbiota was recently demonstrated to promote arterial thrombosis through Toll-like receptor signaling. Furthermore, by the use of germ-free mouse models, the presence of a gut microbiota was shown to influence the synthesis of endothelial adhesion molecules. Hence, the gut microbiota is increasingly being recognized as an influencing factor of arterial thrombosis and attempts of dietary pre- or probiotic modulation of the commensal microbiota, to reduce cardiovascular risk, are becoming increasingly significant.
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http://dx.doi.org/10.3390/microorganisms7120691DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6956001PMC
December 2019

Evaluation of blood collection methods and anticoagulants for platelet function analyses on C57BL/6J laboratory mice.

Platelets 2020 Nov 8;31(8):981-988. Epub 2019 Dec 8.

Center for Thrombosis and Hemostasis (CTH), University Medical Center Mainz, Johannes Gutenberg University of Mainz , Mainz, Germany.

The exploration of thrombotic mechanisms relies on the application of blood collection methods from laboratory mice with a minimal pre-activation of platelets and the clotting system. So far, very little is known on how the blood collection method and the anticoagulant used influence pre-activation of mouse platelets and coagulation. To determine the most suitable blood collection method, we systematically compared blood collection by heart puncture, puncture, and puncture of the retro-orbital vein plexus and the use of citrate, heparin, and EDTA as frequently used anticoagulants with regard to platelet activation and whole blood clotting parameters. The activation of platelet-rich plasma diluted in Tyrode's buffer was analyzed by flow cytometry, analyzing the exposure of P-selectin and activated integrin αβ. Clotting of whole blood was profiled by thrombelastometry. Puncture of the retro-orbital vein plexus by plastic capillaries is not superior in terms of blood volume and platelet pre-activation, whereas heart puncture and puncture resulted in similarly high blood volumes. Cardiac puncture and puncture did not result in pre-activated platelets with citrate as an anticoagulant, but the use of EDTA resulted in increased levels of integrin αβ activation. Puncture of the retro-orbital vein plexus by plastic capillaries resulted in increased platelet integrin αβ activation, which could be prevented by soaking with citrate or coating with heparin. Further, activation of coagulation in citrated whole blood by puncture of the retro-orbital vein plexus using a blunt plastic capillary was observed by thromboelastometry. The use of citrate is the optimal anticoagulant in mouse platelet assays. Blood collections from the heart or represent reliable alternatives to retro-orbital puncture of the vein plexus to avoid pre-activation of platelets and coagulation.
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http://dx.doi.org/10.1080/09537104.2019.1701185DOI Listing
November 2020

Dietary tryptophan links encephalogenicity of autoreactive T cells with gut microbial ecology.

Nat Commun 2019 10 25;10(1):4877. Epub 2019 Oct 25.

DKTK Clinical Cooperation Unit Neuroimmunology and Brain Tumor Immunology, German Cancer Research Center (DKFZ), Heidelberg, Germany.

The interaction between the mammalian host and its resident gut microbiota is known to license adaptive immune responses. Nutritional constituents strongly influence composition and functional properties of the intestinal microbial communities. Here, we report that omission of a single essential amino acid - tryptophan - from the diet abrogates CNS autoimmunity in a mouse model of multiple sclerosis. Dietary tryptophan restriction results in impaired encephalitogenic T cell responses and is accompanied by a mild intestinal inflammatory response and a profound phenotypic shift of gut microbiota. Protective effects of dietary tryptophan restriction are abrogated in germ-free mice, but are independent of canonical host sensors of intracellular tryptophan metabolites. We conclude that dietary tryptophan restriction alters metabolic properties of gut microbiota, which in turn have an impact on encephalitogenic T cell responses. This link between gut microbiota, dietary tryptophan and adaptive immunity may help to develop therapeutic strategies for protection from autoimmune neuroinflammation.
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http://dx.doi.org/10.1038/s41467-019-12776-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6814758PMC
October 2019

The Microbiota Promotes Arterial Thrombosis in Low-Density Lipoprotein Receptor-Deficient Mice.

mBio 2019 10 22;10(5). Epub 2019 Oct 22.

Center for Thrombosis and Hemostasis (CTH), University Medical Center Mainz, Mainz, Germany

Atherosclerotic plaque development depends on chronic inflammation of the arterial wall. A dysbiotic gut microbiota can cause low-grade inflammation, and microbiota composition was linked to cardiovascular disease risk. However, the role of this environmental factor in atherothrombosis remains undefined. To analyze the impact of gut microbiota on atherothrombosis, we rederived low-density lipoprotein receptor-deficient ( ) mice as germfree (GF) and kept these mice for 16 weeks on an atherogenic high-fat Western diet (HFD) under GF isolator conditions and under conventionally raised specific-pathogen-free conditions (CONV-R). In spite of reduced diversity of the cecal gut microbiome, caused by atherogenic HFD, GF mice and CONV-R mice exhibited atherosclerotic lesions of comparable sizes in the common carotid artery. In contrast to HFD-fed mice, showing no difference in total cholesterol levels, CONV-R mice fed control diet (CD) had significantly reduced total plasma cholesterol, very-low-density lipoprotein (VLDL), and LDL levels compared with GF mice. Myeloid cell counts in blood as well as leukocyte adhesion to the vessel wall at the common carotid artery of GF mice on HFD were diminished compared to CONV-R controls. Plasma cytokine profiling revealed reduced levels of the proinflammatory chemokines CCL7 and CXCL1 in GF mice, whereas the T-cell-related interleukin 9 (IL-9) and IL-27 were elevated. In the atherothrombosis model of ultrasound-induced rupture of the common carotid artery plaque, thrombus area was significantly reduced in GF mice relative to CONV-R mice. , this atherothrombotic phenotype was explained by decreased adhesion-dependent platelet activation and thrombus growth of HFD-fed GF mice on type III collagen. Our results demonstrate a functional role for the commensal microbiota in atherothrombosis. In a ferric chloride injury model of the carotid artery, GF C57BL/6J mice had increased occlusion times compared to colonized controls. Interestingly, in late atherosclerosis, HFD-fed GF mice had reduced plaque rupture-induced thrombus growth in the carotid artery and diminished thrombus formation under arterial flow conditions.
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http://dx.doi.org/10.1128/mBio.02298-19DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6805995PMC
October 2019

Antibiotic Treatment Protocols and Germ-Free Mouse Models in Vascular Research.

Front Immunol 2019 12;10:2174. Epub 2019 Sep 12.

Center for Thrombosis and Hemostasis (CTH), University Medical Center Mainz, Johannes Gutenberg University Mainz, Mainz, Germany.

The gut microbiota influence host vascular physiology locally in the intestine, but also evoke remote effects that impact distant organ functions. Amongst others, the microbiota affect intestinal vascular remodeling, lymphatic development, cardiac output and vascular function, myelopoiesis, prothrombotic platelet function, and immunovigilance of the host. Experimentally, host-microbiota interactions are investigated by working with animals devoid of symbiotic bacteria, i.e., by the decimation of gut commensals by antibiotic administration, or by taking advantage of germ-free mouse isolator technology. Remarkably, some of the vascular effects that were unraveled following antibiotic treatment were not observed in the germ-free animal models and . In this review, we will dissect the manifold influences that antibiotics have on the cardiovascular system and their effects on thromboinflammation.
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http://dx.doi.org/10.3389/fimmu.2019.02174DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6751252PMC
November 2020

Flexure-tuned membrane-at-the-edge optomechanical system.

Opt Express 2019 Sep;27(18):25731-25748

We introduce a passively-aligned, flexure-tuned cavity optomechanical system in which a membrane is positioned microns from one end mirror of a Fabry-Perot optical cavity. By displacing the membrane through gentle flexure of its silicon supporting frame (i.e., to ∼80 m radius of curvature (ROC)), we gain access to the full range of available optomechanical couplings, finding also that the optical spectrum exhibits none of the abrupt discontinuities normally found in "membrane-in-the-middle" (MIM) systems. More aggressive flexure (3 m ROC) enables >15 μm membrane travel, milliradian tilt tuning, and a wavelength-scale (1.64 ± 0.78 μm) membrane-mirror separation. We also provide a complete set of analytical expressions for this system's leading-order dispersive and dissipative optomechanical couplings. Notably, this system can potentially generate orders of magnitude larger linear dissipative or quadratic dispersive strong coupling parameters than is possible with a MIM system. Additionally, it can generate the same purely quadratic dispersive coupling as a MIM system, but with significantly suppressed linear dissipative back-action (and force noise).
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http://dx.doi.org/10.1364/OE.27.025731DOI Listing
September 2019

Protease-activated receptor signaling in intestinal permeability regulation.

FEBS J 2020 02 23;287(4):645-658. Epub 2019 Sep 23.

Center for Thrombosis and Hemostasis (CTH), University Medical Center Mainz, Johannes Gutenberg University of Mainz, Germany.

Protease-activated receptors (PARs) are a unique class of G-protein-coupled transmembrane receptors, which revolutionized the perception of proteases from degradative enzymes to context-specific signaling factors. Although PARs are traditionally known to affect several vascular responses, recent investigations have started to pinpoint the functional role of PAR signaling in the gastrointestinal (GI) tract. This organ is exposed to the highest number of proteases, either from the gut lumen or from the mucosa. Luminal proteases include the host's digestive enzymes and the proteases released by the commensal microbiota, while mucosal proteases entail extravascular clotting factors and the enzymes released from resident and infiltrating immune cells. Active proteases and, in case of a disrupted gut barrier, even entire microorganisms are capable to translocate the intestinal epithelium, particularly under inflammatory conditions. Especially PAR-1 and PAR-2, expressed throughout the GI tract, impact gut permeability regulation, a major factor affecting intestinal physiology and metabolic inflammation. In addition, PARs are critically involved in the onset of inflammatory bowel diseases, irritable bowel syndrome, and tumor progression. Due to the number of proteases involved and the multiple cell types affected, selective regulation of intestinal PARs represents an interesting therapeutic strategy. The analysis of tissue/cell-specific knockout animal models will be of crucial importance to unravel the intrinsic complexity of this signaling network. Here, we provide an overview on the implication of PARs in intestinal permeability regulation under physiologic and disease conditions.
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http://dx.doi.org/10.1111/febs.15055DOI Listing
February 2020

Tissue factor pathway inhibitor primes monocytes for antiphospholipid antibody-induced thrombosis.

Blood 2019 10 21;134(14):1119-1131. Epub 2019 Aug 21.

Center for Thrombosis and Hemostasis and.

Antiphospholipid antibodies (aPLs) with complex lipid and/or protein reactivities cause complement-dependent thrombosis and pregnancy complications. Although cross-reactivities with coagulation regulatory proteins contribute to the risk for developing thrombosis in patients with antiphospholipid syndrome, the majority of pathogenic aPLs retain reactivity with membrane lipid components and rapidly induce reactive oxygen species-dependent proinflammatory signaling and tissue factor (TF) procoagulant activation. Here, we show that lipid-reactive aPLs activate a common species-conserved TF signaling pathway. aPLs dissociate an inhibited TF coagulation initiation complex on the cell surface of monocytes, thereby liberating factor Xa for thrombin generation and protease activated receptor 1/2 heterodimer signaling. In addition to proteolytic signaling, aPLs promote complement- and protein disulfide isomerase-dependent TF-integrin β1 trafficking that translocates aPLs and NADPH oxidase to the endosome. Cell surface TF pathway inhibitor (TFPI) synthesized by monocytes is required for TF inhibition, and disabling TFPI prevents aPL signaling, indicating a paradoxical prothrombotic role for TFPI. Myeloid cell-specific TFPI inactivation has no effect on models of arterial or venous thrombus development, but remarkably prevents experimental aPL-induced thrombosis in mice. Thus, the physiological control of TF primes monocytes for rapid aPL pathogenic signaling and thrombosis amplification in an unexpected crosstalk between complement activation and coagulation signaling.
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http://dx.doi.org/10.1182/blood.2019001530DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6776793PMC
October 2019

The Microbiota: A Microbial Ecosystem Built on Mutualism Prevails.

J Innate Immun 2019 20;11(5):391-392. Epub 2019 Jun 20.

Center for Thrombosis and Hemostasis (CTH), University Medical Center Mainz, Johannes Gutenberg University of Mainz, Mainz, Germany,

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http://dx.doi.org/10.1159/000501237DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6738262PMC
June 2020

The gut microbiota - a modulator of endothelial cell function and a contributing environmental factor to arterial thrombosis.

Expert Rev Hematol 2019 07 10;12(7):541-549. Epub 2019 Jun 10.

a Center for Thrombosis and Hemostasis (CTH) , University Medical Center Mainz, Johannes Gutenberg University Mainz , Mainz , Germany.

: There is emerging evidence linking the commensal gut microbiota with the development of cardiovascular disease and arterial thrombosis. In immunothrombosis, the host clotting system protects against the dissemination of invading microbes, not considering the huge number of microbes that interact with host physiology in a mutualistic fashion. : Interestingly, recent research revealed that colonizing gut microbes profoundly influence host innate immune pathways that support arterial thrombus growth. The gut microbiota promotes arterial thrombus formation by enhancing the pro-adhesive capacity of the vascular endothelium, triggering hepatic von Willebrand factor synthesis and its release by Weibel-Palade body exocytosis, resulting in elevated von Willebrand factor levels and enhancing FVIII stability in plasma. Furthermore, the metabolic capacity of gut resident microbes promotes agonist-induced platelet activation and deposition. Here, we give an overview, with a focus on the vascular endothelium, on how this gut-resident microbial ecosystem contributes to arterial thrombus formation. : The gut microbiota and its metabolites not only act on agonist-induced platelet reactivity, but also influence the hepatic endothelial phenotype via remote signaling, facilitating arterial thrombus growth at the arterial injury site.
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http://dx.doi.org/10.1080/17474086.2019.1627191DOI Listing
July 2019

Common miRNA Patterns of Alzheimer's Disease and Parkinson's Disease and Their Putative Impact on Commensal Gut Microbiota.

Front Neurosci 2019 5;13:113. Epub 2019 Mar 5.

Faculty of Biology, Institute for Developmental Biology and Neurobiology, Center of Computational Sciences Mainz (CSM), Johannes Gutenberg University Mainz, Mainz, Germany.

With the rise of Next-Generation-Sequencing (NGS) methods, Micro-RNAs (miRNAs) have achieved an important position in the research landscape and have been found to present valuable diagnostic tools in various diseases such as multiple sclerosis or lung cancer. There is also emerging evidence that miRNAs play an important role in the pathogenesis of neurodegenerative diseases such as Alzheimer's disease (AD) or Parkinson's disease (PD). Apparently, these diseases come along with changes in miRNA expression patterns which led to attempts from researchers to use these small RNA species from several body fluids for a better diagnosis and in order to observe disease progression. Additionally, it became evident that microbial commensals might play an important role for pathology development and were shown to have a significantly different composition in patients suffering from neurodegeneration compared with healthy controls. As it could recently be shown that secreted miRNAs are able to enter microbial organisms, it is conceivable that the host's miRNA might affect the gut microbial ecosystem. As such, miRNAs may inherit a central role in shaping the "diseased microbiome" and thereby mutually act on the characteristics of these neurodegenerative diseases. We have therefore (1) compiled a list of miRNAs known to be associated with AD and/or PD, (2) performed an target screen for binding sites of these miRNA on human gut metagenome sequences and (3) evaluated the hit list for interesting matches potentially relevant to the etiology of AD and or PD. The examination of protein identifiers connected to bacterial secretion system, lipopolysaccharide biosynthesis and biofilm formation revealed an overlap of 37 bacterial proteins that were targeted by human miRNAs. The identified links of miRNAs to the biological processes of bacteria connected to AD and PD have yet to be validated via experiments. However, our results show a promising new approach for understanding aspects of these neurodegenerative diseases in light of the regulation of the microbiome.
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http://dx.doi.org/10.3389/fnins.2019.00113DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6411762PMC
March 2019

Comment on "Endothelial Protein C Receptor (EPCR), Protease Activated Receptor-1 (PAR-1) and Their Interplay in Cancer Growth and Metastatic Dissemination" 2019, , 51.

Cancers (Basel) 2019 Mar 16;11(3). Epub 2019 Mar 16.

Center for Thrombosis and Hemostasis (CTH), University Medical Center Mainz, Johannes Gutenberg University of Mainz, Langenbeckstrasse 1, 55131 Mainz, Germany.

Although the interplay between tumor progression and blood coagulation has been recognized [...].
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http://dx.doi.org/10.3390/cancers11030374DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6468748PMC
March 2019

Hypoxia evokes increased PDI and PDIA6 expression in the infarcted myocardium of ex-germ-free and conventionally raised mice.

Biol Open 2019 Jan 2;8(1). Epub 2019 Jan 2.

Center for Thrombosis and Hemostasis (CTH), University Medical Center Mainz, Johannes Gutenberg University Mainz, Langenbeckstrasse 1, 55131 Mainz, Germany

The prototypic protein disulfide isomerase (PDI), encoded by the gene, has been described as a survival factor in ischemic cardiomyopathy. However, the role of protein disulfide isomerase associated 6 (PDIA6) under hypoxic conditions in the myocardium remains enigmatic, and it is unknown whether the gut microbiota influences the expression of PDI and PDIA6 under conditions of acute myocardial infarction. Here, we revealed that, in addition to the prototypic PDI, the PDI family member PDIA6, a regulator of the unfolded protein response, is upregulated in the mouse cardiomyocyte cell line HL-1 when cultured under hypoxia. , in the left anterior descending artery (LAD) ligation mouse model of acute myocardial infarction, similar to PDI, PDIA6 protein expression was enhanced in the infarcted area (LAD+) relative to uninfarcted sham tissue or the neighbouring area at risk (LAD-) of C57BL/6J mice. Interestingly, we found that ex-germ-free (ex-GF) mice subjected to the LAD ligation model for 24 h had a reduced ejection fraction compared with their conventionally raised (CONV-R) SPF controls. Furthermore, the LAD+ area in the infarcted heart of ex-GF mice showed reduced PDIA6 expression relative to CONV-R controls, suggesting that the presence of a gut microbiota enhanced LAD ligation-triggered PDIA6 expression. Collectively, our results demonstrate that PDIA6 is upregulated in cardiomyocytes as a consequence of hypoxia. In the LAD mouse model, PDIA6 was also increased in the infarcted area under conditions, but this increase was suppressed in ex-GF mice relative to CONV-R controls.This article has an associated First Person interview with the first author of the paper.
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http://dx.doi.org/10.1242/bio.038851DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6361221PMC
January 2019

The Gut Microbiota as an Influencing Factor of Arterial Thrombosis.

Hamostaseologie 2019 Jun 20;39(2):173-179. Epub 2018 Nov 20.

Center for Thrombosis and Hemostasis (CTH), University Medical Center Mainz, Johannes Gutenberg University of Mainz, Mainz, Germany.

The mutualistic gut microbiota does not only impact the development and function of various immune cell types, but it also influences the function of the hepatic vascular endothelium and prothrombotic platelet function. With germ-free mouse models, we have demonstrated that gut-derived microbial-associated molecular patterns could stimulate hepatic von Willebrand factor (VWF) synthesis and plasmatic VWF levels through Toll-like receptor-2 (TLR2), thus defining the extent of platelet deposition to the subendothelial matrix of the ligation-injured common carotid artery. In addition to the microbiota-derived choline metabolite trimethylamine N-oxide and the microbiota's regulatory role on the colonic serotonin biosynthesis pathway, affecting prothrombotic platelet function, TLR2-regulated hepatic endothelial VWF synthesis and elevated VWF plasma levels constitute a pivotal mechanism of how the gut microbiota is linked to arterial thrombosis. Conceptually, in addition to the identified functions of the gut microbiota in modulating host nutrition and metabolism, our work places the innate immune functions of the liver sinusoidal endothelium as an actuating variable in arterial thrombus growth.
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http://dx.doi.org/10.1055/s-0038-1675357DOI Listing
June 2019

Post-transcriptional, post-translational and pharmacological regulation of tissue factor pathway inhibitor.

Blood Coagul Fibrinolysis 2018 Dec;29(8):668-682

Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.

: Tissue factor (TF) pathway inhibitor (TFPI) is an endogenous natural anticoagulant that readily inhibits the extrinsic coagulation initiation complex (TF-FVIIa-Xa) and prothrombinase (FXa, FVa and calcium ions). Alternatively, spliced TFPI isoforms (α, β and δ) are expressed by vascular and extravascular cells and regulate thrombosis and haemostasis, as well as cell signalling functions of TF complexes via protease-activated receptors (PARs). Proteolysis of TFPI plays an important role in regulating physiological roles of the TF pathway in host defense and possibly haemostasis. Elimination of TFPI inhibition has therefore been proposed as an approach to improve haemostasis in haemophilia patients. In this review, we focus on posttranscription and translational modification of TFPI and its function in thrombosis and how pharmacological inhibitors and endogenous proteases interfere with TFPI and alter haemostasis.
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http://dx.doi.org/10.1097/MBC.0000000000000775DOI Listing
December 2018

Microbiota-Derived Trimethylamine.

Circ Res 2018 10;123(10):1112-1114

From the Center for Thrombosis and Hemostasis, University Medical Center Mainz, Johannes Gutenberg University of Mainz, Germany (K.K., W.R., C.R.).

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http://dx.doi.org/10.1161/CIRCRESAHA.118.314039DOI Listing
October 2018

The Involvement of Toll-like Receptor-2 in Arterial Thrombus Formation.

Hamostaseologie 2018 Nov 27;38(4):223-228. Epub 2018 Sep 27.

Center for Thrombosis and Hemostasis (CTH), University Medical Center Mainz, Johannes Gutenberg University of Mainz, Mainz, Germany.

There is emerging evidence for the participation of toll-like receptor-2 (TLR2) expressed on platelets and endothelial cells in the setting of arterial thrombosis. In isolated human platelets, TLR2/1 activation was demonstrated to induce platelet activation, secretion, aggregation, adhesion to collagen coatings and the formation of platelet-leukocyte conjugates, whereas murine platelets were less sensitive to TLR2/1 stimulation. Also, endothelial cells can be activated by stimulation with TLR2 agonists, resulting in increased expression of adhesion molecules, synthesis of inflammatory mediators and Weibel-Palade body exocytosis. Endothelial TLR2 signalling promotes atherosclerotic lesion development in mouse atherosclerosis models. Experiments with germ-free mouse models demonstrated that the presence of commensal microbiota increased endothelial von Willebrand factor synthesis in the liver through TLR2. In the carotid artery ligation model, the elevated von Willebrand factor plasma levels enhanced platelet deposition to the injury site. Furthermore, in the hyperlipidemic ApoE-deficient mouse model, TLR2 deficiency was shown to protect from ferric chloride-induced carotid artery thrombosis. This review article provides an overview on TLR2 signalling in platelets and the vascular endothelium and summarizes how TLR2 signalling contributes to arterial thrombosis.
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http://dx.doi.org/10.1055/s-0038-1668164DOI Listing
November 2018

Contribution of the commensal microbiota to atherosclerosis and arterial thrombosis.

Br J Pharmacol 2018 12 25;175(24):4439-4449. Epub 2018 Sep 25.

Center for Thrombosis and Hemostasis (CTH), University Medical Center of the Johannes Gutenberg University of Mainz, Mainz, Germany.

The commensal gut microbiota is an environmental factor that has been implicated in the development of cardiovascular disease. The development of atherosclerotic lesions is largely influenced not only by the microbial-associated molecular patterns of the gut microbiota but also by the meta-organismal trimethylamine N-oxide pathway. Recent studies have described a role for the gut microbiota in platelet activation and arterial thrombosis. This review summarizes the results from gnotobiotic mouse models and clinical data that linked microbiota-induced pattern recognition receptor signalling with atherogenesis. Based on recent insights, we here provide an overview of how the gut microbiota could affect endothelial cell function and platelet activation, to promote arterial thrombosis. LINKED ARTICLES: This article is part of a themed section on When Pharmacology Meets the Microbiome: New Targets for Therapeutics? To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v175.24/issuetoc.
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http://dx.doi.org/10.1111/bph.14483DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6255953PMC
December 2018