scholarly journals Silencing Bruton's tyrosine kinase in alveolar neutrophils protects mice from LPS/immune complex-induced acute lung injury

2014 ◽  
Vol 307 (6) ◽  
pp. L435-L448 ◽  
Author(s):  
Agnieszka Krupa ◽  
Marek Fol ◽  
Moshiur Rahman ◽  
Karen Y. Stokes ◽  
Jon M. Florence ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Tyrosine Kinase ◽  
Immune Complex ◽  
Distress Syndrome ◽  
Bruton’S Tyrosine Kinase ◽  
Bruton's Tyrosine Kinase ◽  
Neutrophil Survival

Previous observations made by our laboratory indicate that Bruton's tyrosine kinase (Btk) may play an important role in the pathophysiology of local inflammation in acute lung injury (ALI)/acute respiratory distress syndrome (ARDS). We have shown that there is cross talk between FcγRIIa and TLR4 in alveolar neutrophils from patients with ALI/ARDS and that Btk mediates the molecular cooperation between these two receptors. To study the function of Btk in vivo we have developed a unique two-hit model of ALI: LPS/immune complex (IC)-induced ALI. Furthermore, we conjugated F(ab)2 fragments of anti-neutrophil antibodies (Ly6G1A8) with specific siRNA for Btk to silence Btk specifically in alveolar neutrophils. It should be stressed that we are the first group to perform noninvasive transfections of neutrophils, both in vitro and in vivo. Importantly, our present findings indicate that silencing Btk in alveolar neutrophils has a dramatic protective effect in mice with LPS/IC-induced ALI, and that Btk regulates neutrophil survival and clearance of apoptotic neutrophils in this model. In conclusion, we put forward a hypothesis that Btk-targeted neutrophil specific therapy is a valid goal of research geared toward restoring homeostasis in lungs of patients with ALI/ARDS.

scholarly journals The Crucial Role of PPARγ-Egr-1-Pro-Inflammatory Mediators Axis in IgG Immune Complex-Induced Acute Lung Injury

2021 ◽  
Vol 12 ◽  
Author(s):  
Chunguang Yan ◽  
Jing Chen ◽  
Yue Ding ◽  
Zetian Zhou ◽  
Bingyu Li ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Acute Lung Injury ◽  
Lung Injury ◽  
Immune Complex ◽  
Inflammatory Mediators ◽  
Lung Inflammation ◽  
Acute Lung Inflammation ◽  
Pparγ Agonist

BackgroundThe ligand-activated transcription factor peroxisome proliferator-activated receptor (PPAR) γ plays crucial roles in diverse biological processes including cellular metabolism, differentiation, development, and immune response. However, during IgG immune complex (IgG-IC)-induced acute lung inflammation, its expression and function in the pulmonary tissue remains unknown.ObjectivesThe study is designed to determine the effect of PPARγ on IgG-IC-triggered acute lung inflammation, and the underlying mechanisms, which might provide theoretical basis for therapy of acute lung inflammation.SettingDepartment of Pathogenic Biology and Immunology, Medical School of Southeast UniversitySubjectsMice with down-regulated/up-regulated PPARγ activity or down-regulation of Early growth response protein 1 (Egr-1) expression, and the corresponding controls.InterventionsAcute lung inflammation is induced in the mice by airway deposition of IgG-IC. Activation of PPARγ is achieved by using its agonist Rosiglitazone or adenoviral vectors that could mediate overexpression of PPARγ. PPARγ activity is suppressed by application of its antagonist GW9662 or shRNA. Egr-1 expression is down-regulated by using the gene specific shRNA.Measures and Main ResultsWe find that during IgG-IC-induced acute lung inflammation, PPARγ expression at both RNA and protein levels is repressed, which is consistent with the results obtained from macrophages treated with IgG-IC. Furthermore, both in vivo and in vitro data show that PPARγ activation reduces IgG-IC-mediated pro-inflammatory mediators’ production, thereby alleviating lung injury. In terms of mechanism, we observe that the generation of Egr-1 elicited by IgG-IC is inhibited by PPARγ. As an important transcription factor, Egr-1 transcription is substantially increased by IgG-IC in both in vivo and in vitro studies, leading to augmented protein expression, thus amplifying IgG-IC-triggered expressions of inflammatory factors via association with their promoters.ConclusionDuring IgG-IC-stimulated acute lung inflammation, PPARγ activation can relieve the inflammatory response by suppressing the expression of its downstream target Egr-1 that directly binds to the promoter regions of several inflammation-associated genes. Therefore, regulation of PPARγ-Egr-1-pro-inflammatory mediators axis by PPARγ agonist Rosiglitazone may represent a novel strategy for blockade of acute lung injury.

scholarly journals Oral administration of Bruton's tyrosine kinase inhibitors impairs GPVI-mediated platelet function

2016 ◽  
Vol 310 (5) ◽  
pp. C373-C380 ◽  
Author(s):  
Rachel A. Rigg ◽  
Joseph E. Aslan ◽  
Laura D. Healy ◽  
Michael Wallisch ◽  
Marisa L. D. Thierheimer ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Platelet Activation ◽  
Platelet Function ◽  
Lymphocytic Leukemia ◽  
Bruton’S Tyrosine Kinase ◽  
Bruton's Tyrosine Kinase ◽  
Glycoprotein Vi ◽  
Activation Spreading

The Tec family kinase Bruton's tyrosine kinase (Btk) plays an important signaling role downstream of immunoreceptor tyrosine-based activation motifs in hematopoietic cells. Mutations in Btk are involved in impaired B-cell maturation in X-linked agammaglobulinemia, and Btk has been investigated for its role in platelet activation via activation of the effector protein phospholipase Cγ2 downstream of the platelet membrane glycoprotein VI (GPVI). Because of its role in hematopoietic cell signaling, Btk has become a target in the treatment of chronic lymphocytic leukemia and mantle cell lymphoma; the covalent Btk inhibitor ibrutinib was recently approved by the US Food and Drug Administration for treatment of these conditions. Antihemostatic events have been reported in some patients taking ibrutinib, although the mechanism of these events remains unknown. We sought to determine the effects of Btk inhibition on platelet function in a series of in vitro studies of platelet activation, spreading, and aggregation. Our results show that irreversible inhibition of Btk with two ibrutinib analogs in vitro decreased human platelet activation, phosphorylation of Btk, P-selectin exposure, spreading on fibrinogen, and aggregation under shear flow conditions. Short-term studies of ibrutinib analogs administered in vivo also showed abrogation of platelet aggregation in vitro, but without measurable effects on plasma clotting times or on bleeding in vivo. Taken together, our results suggest that inhibition of Btk significantly decreased GPVI-mediated platelet activation, spreading, and aggregation in vitro; however, prolonged bleeding was not observed in a model of bleeding.

scholarly journals Bruton’s Tyrosine Kinase Inhibition Promotes Myelin Repair

2020 ◽  
Vol 5 (2) ◽  
pp. 123-133
Author(s):  
Elodie Martin ◽  
Marie-Stéphane Aigrot ◽  
Roland Grenningloh ◽  
Bruno Stankoff ◽  
Catherine Lubetzki ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Ex Vivo ◽  
Fold Increase ◽  
Experimental Models ◽  
Bruton’S Tyrosine Kinase ◽  
Bruton's Tyrosine Kinase ◽  
Myelin Repair ◽  
Before And After

Background: Microglia are the resident macrophages of the central nervous system (CNS). In multiple sclerosis (MS) and related experimental models, microglia have either a pro-inflammatory or a pro-regenerative/pro-remyelinating function. Inhibition of Bruton’s tyrosine kinase (BTK), a member of the Tec family of kinases, has been shown to block differentiation of pro-inflammatory macrophages in response to granulocyte–macrophage colony-stimulating factor in vitro. However, the role of BTK in the CNS is unknown. Methods: Our aim was to investigate the effect of BTK inhibition on myelin repair in ex vivo and in vivo experimental models of demyelination and remyelination. The remyelination effect of a BTK inhibitor (BTKi; BTKi-1) was then investigated in LPC-induced demyelinated cerebellar organotypic slice cultures and metronidazole-induced demyelinated Xenopus MBP-GFP-NTR transgenic tadpoles. Results: Cellular detection of BTK and its activated form BTK-phospho-Y223 (p-BTK) was determined by immunohistochemistry in organotypic cerebellar slice cultures, before and after lysophosphatidylcholine (LPC)-induced demyelination. A low BTK signal detected by immunolabeling under normal conditions in cerebellar slices was in sharp contrast to an 8.5-fold increase in the number of BTK-positive cells observed in LPC-demyelinated slice cultures. Under both conditions, approximately 75% of cells expressing BTK and p-BTK were microglia and 25% were astrocytes. Compared with spontaneous recovery, treatment of demyelinated slice cultures and MTZ-demyelinated transgenic tadpoles with BTKi resulted in at least a 1.7-fold improvement of remyelination. Conclusion: Our data demonstrate that BTK inhibition is a promising therapeutic strategy for myelin repair.

scholarly journals Targeting Bruton’s Tyrosine Kinase in Inflammatory and Autoimmune Pathologies

2021 ◽  
Vol 9 ◽  
Author(s):  
Stefan F. H. Neys ◽  
Rudi W. Hendriks ◽  
Odilia B. J. Corneth
Keyword(s):  
B Cells ◽  
Tyrosine Kinase ◽  
B Cell ◽  
Critical Role ◽  
Myeloid Cells ◽  
Systemic Autoimmune Disease ◽  
Bruton’S Tyrosine Kinase ◽  
Bruton's Tyrosine Kinase

Bruton’s tyrosine kinase (BTK) was discovered due to its importance in B cell development, and it has a critical role in signal transduction downstream of the B cell receptor (BCR). Targeting of BTK with small molecule inhibitors has proven to be efficacious in several B cell malignancies. Interestingly, recent studies reveal increased BTK protein expression in circulating resting B cells of patients with systemic autoimmune disease (AID) compared with healthy controls. Moreover, BTK phosphorylation following BCR stimulation in vitro was enhanced. In addition to its role in BCR signaling, BTK is involved in many other pathways, including pattern recognition, Fc, and chemokine receptor signaling in B cells and myeloid cells. This broad involvement in several immunological pathways provides a rationale for the targeting of BTK in the context of inflammatory and systemic AID. Accordingly, numerous in vitro and in vivo preclinical studies support the potential of BTK targeting in these conditions. Efficacy of BTK inhibitors in various inflammatory and AID has been demonstrated or is currently evaluated in clinical trials. In addition, very recent reports suggest that BTK inhibition may be effective as immunosuppressive therapy to diminish pulmonary hyperinflammation in coronavirus disease 2019 (COVID-19). Here, we review BTK’s function in key signaling pathways in B cells and myeloid cells. Further, we discuss recent advances in targeting BTK in inflammatory and autoimmune pathologies.

scholarly journals Bruton's Tyrosine Kinase Is Required for Activation of Iκb Kinase and Nuclear Factor κb in Response to B Cell Receptor Engagement

2000 ◽  
Vol 191 (10) ◽  
pp. 1745-1754 ◽  
Author(s):  
James B. Petro ◽  
S.M. Jamshedur Rahman ◽  
Dean W. Ballard ◽  
Wasif N. Khan
Keyword(s):  
Tyrosine Kinase ◽  
B Cell ◽  
Cell Cycle Progression ◽  
Coupling Mechanism ◽  
Bruton’S Tyrosine Kinase ◽  
Nuclear Factor ◽  
Bruton's Tyrosine Kinase ◽  
Iκb Kinase

Mutations in the gene encoding Bruton's tyrosine kinase (btk) cause the B cell deficiency diseases X-linked agammaglobulinemia (XLA) in humans and X-linked immunodeficiency (xid) in mice. In vivo and in vitro studies indicate that the BTK protein is essential for B cell survival, cell cycle progression, and proliferation in response to B cell antigen receptor (BCR) stimulation. BCR stimulation leads to the activation of transcription factor nuclear factor (NF)-κB, which in turn regulates genes controlling B cell growth. We now demonstrate that a null mutation in btk known to cause the xid phenotype prevents BCR-induced activation of NF-κB. This defect can be rescued by reconstitution with wild-type BTK. This mutation also interferes with BCR-directed activation of IκB kinase (IKK), which normally targets the NF-κB inhibitor IκBα for degradation. Taken together, these findings indicate that BTK couples IKK and NF-κB to the BCR. Interference with this coupling mechanism may contribute to the B cell deficiencies observed in XLA and xid.

scholarly journals Inhibiting Bruton’s tyrosine kinase rescues mice from lethal influenza-induced acute lung injury

2018 ◽  
Vol 315 (1) ◽  
pp. L52-L58 ◽  
Author(s):  
Jon M. Florence ◽  
Agnieszka Krupa ◽  
Laela M. Booshehri ◽  
Sandra A. Davis ◽  
Michael A. Matthay ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Tyrosine Kinase ◽  
Lung Inflammation ◽  
Influenza A ◽  
Neutrophil Extracellular Trap ◽  
Bruton’S Tyrosine Kinase ◽  
Bruton's Tyrosine Kinase ◽  
Lung Dysfunction ◽  
Btk Inhibitor

Infection with seasonal influenza A virus (IAV) leads to lung inflammation and respiratory failure, a main cause of death in influenza-infected patients. Previous experiments in our laboratory indicate that Bruton’s tyrosine kinase (Btk) plays a substantial role in regulating inflammation in the respiratory region during acute lung injury in mice; therefore, we sought to determine if blocking Btk activity has a protective effect in the lung during influenza-induced inflammation. The Btk inhibitor ibrutinib (also known as PCI-32765) was administered intranasally to mice starting 72 h after lethal infection with IAV. Our data indicate that treatment with the Btk inhibitor not only reduced weight loss and led to survival, but also had a dramatic effect on morphological changes to the lungs, in IAV-infected mice. Attenuation of lung inflammation indicative of acute lung injury, such as alveolar hemorrhage, interstitial thickening, and the presence of alveolar exudate, together with reduced levels of the inflammatory mediators TNFα, IL-1β, IL-6, KC, and MCP-1, strongly suggests amelioration of the pathological immune response in the lungs to promote resolution of the infection. Finally, we observed that blocking Btk specifically in the alveolar compartment led to significant attenuation of neutrophil extracellular traps released into the lung in vivo and neutrophil extracellular trap formation in vitro. Our innovative findings suggest that Btk may be a new drug target for influenza-induced lung injury, and, in general, that immunomodulatory treatment may be key in treating lung dysfunction driven by excessive inflammation.

scholarly journals In vitro and in vivo assessment of the protective effect of sufentanil in acute lung injury

2021 ◽  
Vol 49 (2) ◽  
pp. 030006052098635
Author(s):  
Qi Gao ◽  
Ningqing Chang ◽  
Donglian Liu
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Protective Effect ◽  
High Mobility ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Inflammatory Factors ◽  
Luciferase Reporter ◽  
Hmgb1 Protein

Objectives To investigate the mechanisms underlying the protective effect of sufentanil against acute lung injury (ALI). Material and Methods Rats were administered lipopolysaccharide (LPS) by endotracheal instillation to establish a model of ALI. LPS was used to stimulate BEAS-2B cells. The targets and promoter activities of IκB were assessed using a luciferase reporter assay. Apoptosis of BEAS-2B cells was evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling. Results Sufentanil treatment markedly reduced pathological changes in lung tissue, pulmonary edema and secretion of inflammatory factors associated with ALI in vivo and in vitro. In addition, sufentanil suppressed apoptosis induced by LPS and activated NF-κB both in vivo and in vitro. Furthermore, upregulation of high mobility group box protein 1 (HMGB1) protein levels and downregulation of miR-129-5p levels were observed in vivo and in vitro following sufentanil treatment. miR-129-5p targeted the 3ʹ untranslated region and its inhibition decreased promoter activities of IκB-α. miR-129-5p inhibition significantly weakened the protective effect of sufentanil on LPS-treated BEAS-2B cells. Conclusion Sufentanil regulated the miR-129-5p/HMGB1 axis to enhance IκB-α expression, suggesting that sufentanil represents a candidate drug for ALI protection and providing avenues for clinical treatment.

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