scholarly journals IFNγ and TNFα mediate CCL22/MDC production in alveolar macrophages after hemorrhage and resuscitation

2020 ◽  
Vol 318 (5) ◽  
pp. L864-L872
Author(s):  
Nadine Beckmann ◽  
Jeffrey M. Sutton ◽  
Richard S. Hoehn ◽  
Peter L. Jernigan ◽  
Lou Ann Friend ◽  
...  
Keyword(s):  
Alveolar Macrophages ◽  
Inflammatory Cell ◽  
Pulmonary Inflammation ◽  
Major Complication ◽  
Signaling Mechanism ◽  
Precise Role ◽  
Autocrine Mechanism

Acute lung injury is a major complication of hemorrhagic shock and the required resuscitation with large volumes of crystalloid fluids and blood products. We previously identified a role of macrophage-derived chemokine (CCL22/MDC) pulmonary inflammation following hemorrhage and resuscitation. However, further details regarding the induction of CCL22/MDC and its precise role in pulmonary inflammation after trauma remain unknown. In the current study we used in vitro experiments with a murine alveolar macrophage cell line, as well as an in vivo mouse model of hemorrhage and resuscitation, to identify key regulators in CCL22/MDC production. We show that trauma induces expression of IFNγ, which leads to production of CCL22/MDC through a signaling mechanism involving p38 MAPK, NF-κB, JAK, and STAT-1. IFNγ also activates TNFα production by alveolar macrophages, potentiating CCL22/MDC production via an autocrine mechanism. Neutralization of IFNγ or TNFα with specific antibodies reduced histological signs of pulmonary injury after hemorrhage and reduced inflammatory cell infiltration into the lungs.

Multinucleated rat alveolar macrophages express functional receptors for calcitonin

1991 ◽  
Vol 261 (6) ◽  
pp. F1026-F1032 ◽  
Author(s):  
A. Vignery ◽  
M. J. Raymond ◽  
H. Y. Qian ◽  
F. Wang ◽  
S. A. Rosenzweig
Keyword(s):  
Plasma Membrane ◽  
Alveolar Macrophages ◽  
Giant Cells ◽  
Mononuclear Phagocytes ◽  
Inflammatory Reactions ◽  
Calcitonin Gene ◽  
Novel Model

The fusion of mononuclear phagocytes occurs spontaneously in vivo and leads to the differentiation of either multinucleated giant cells or osteoclasts in chronic inflammatory sites or in bone, respectively. Although osteoclasts are responsible for resorbing bone, the functional role of giant cells in chronic inflammatory reactions and tumors remains poorly understood. We recently reported that the plasma membrane of multinucleated macrophages is, like that of osteoclasts, enriched in Na-K-adenosinetriphosphatases (ATPases). We also observed that the localization of their Na-K-ATPases is restricted to the nonadherent domain of the plasma membrane of cells both in vivo and in vitro, thus imposing a functional polarity on their organization. By following this observation, we wished to investigate whether these cells also expressed, like osteoclasts, functional receptors for calcitonin (CT). To this end, alveolar macrophages were fused in vitro, and both their structural and functional association with CT was analyzed and compared with those of mononucleated peritoneal and alveolar macrophages. Evidence is presented that multinucleated alveolar macrophages express a high copy number of functional receptors for CT. Our results also indicate that alveolar macrophages, much like peritoneal, express functional receptors for calcitonin gene-related peptide. It is suggested that multinucleated rat alveolar macrophages offer a novel model system to study CT receptors and that calcitonin may control local immune reactions where giant cells differentiate.

β3 Tyrosine Phosphorylation in αIIbβ3 (Platelet Membrane GP IIb-IIIa) Outside-in Integrin Signaling

2001 ◽  
Vol 86 (07) ◽  
pp. 246-258 ◽  
Author(s):  
Lisa Nannizzi-Alaimo ◽  
K. S. Srinivasa Prasad ◽  
David Phillips
Keyword(s):  
Platelet Aggregation ◽  
Tyrosine Phosphorylation ◽  
Critical Role ◽  
Clot Retraction ◽  
Signaling Mechanism ◽  
Platelet Aggregate ◽  
Von Willebrand

SummaryThe platelet integrin αIIbβ3 not only binds fibrinogen and von Willebrand factor to mediate platelet aggregation and adhesion, it also serves as a signaling receptor. Platelet agonists such as ADP, thrombin and collagen induce “inside-out” signaling which activates the receptor function of αIIbβ3 for soluble fibrinogen. Subsequent platelet aggregation leads to “outside-in” signaling, inducing platelet aggregate stabilization and triggering a variety of functions important to platelet physiology. This review focuses on the role of β3 tyrosine phosphorylation in αIIbβ3 outside-in signaling. Tyrosine phosphorylation of β3 in platelets is a dynamic process which is initiated upon platelet aggregation and also by adhesion of platelets to immobilized fibrinogen. Tyrosine phosphorylation occurs on the β3 integrin cytoplasmic tyrosine (ICY) domain, a conserved motif found in thesubunits of several integrins. β3 ICY domain tyrosine phosphorylation induces the recruitment of two proteins to the cytoplasmic domains of αIIbβ3: the cytoskeletal protein myosin, important to clot retraction; and the signaling adapter protein Shc, important to platelet stimulation. The critical role of β3 tyrosine phosphorylation to platelet function was established by the diYF mouse, a novel strain which expresses an αIIbβ3 in which the two β3 ICY domain tyrosines have been mutated to phenylalanine. These mice are selectively impaired in outside-in αIIbβ3 signaling, with defective aggregation and clot-retraction responses in vitro, and an in vivo bleeding defect which is characterized by a pronounced tendency to rebleed. Taken together, the data suggest that the β3 tyrosine phosphorylation signaling mechanism is important to αIIbβ3 function and might be applicable to a wide variety of integrin-mediated events.

scholarly journals Polymerization Defects within Human Telomerase Are Distinct from Telomerase RNA and TEP1 Binding

2000 ◽  
Vol 11 (10) ◽  
pp. 3329-3340 ◽  
Author(s):  
Tara L. Beattie ◽  
Wen Zhou ◽  
Murray O. Robinson ◽  
Lea Harrington
Keyword(s):  
Telomerase Activity ◽  
Amino Terminus ◽  
Telomerase Rna ◽  
Carboxy Terminus ◽  
Active Core ◽  
Human Telomerase ◽  
Precise Role

The minimal, active core of human telomerase is postulated to contain two components, the telomerase RNA hTER and the telomerase reverse transcriptase hTERT. The reconstitution of human telomerase activity in vitro has facilitated the identification of sequences within the telomerase RNA and the RT motifs of hTERT that are essential for telomerase activity. However, the precise role of residues outside the RT domain of hTERT is unknown. Here we have delineated several regions within hTERT that are important for telomerase catalysis, primer use, and interaction with the telomerase RNA and the telomerase-associated protein TEP1. In particular, certain deletions of the amino and carboxy terminus of hTERT that retained an interaction with telomerase RNA and TEP1 were nonetheless completely inactive in vitro and in vivo. Furthermore, hTERT truncations lacking the amino terminus that were competent to bind the telomerase RNA were severely compromised for the ability to elongate telomeric and nontelomeric primers. These results suggest that the interaction of telomerase RNA with hTERT can be functionally uncoupled from polymerization, and that there are regions outside the RT domain of hTERT that are critical for telomerase activity and primer use. These results establish that the human telomerase RT possesses unique polymerization determinants that distinguish it from other RTs.

scholarly journals E3 Ubiquitin Ligase TRIM29 Promotes Pancreatic Cancer Growth and Progression via Stabilizing Yes-associated Protein 1

2021 ◽  
Author(s):  
Xueqiang Deng ◽  
Xiaowei Fu ◽  
Hong Teng ◽  
Lu Fang ◽  
Bo Liang ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Cell Cycle Progression ◽  
Nude Mouse Model ◽  
Cycle Progression ◽  
Signal Cascade ◽  
The Relationship ◽  
Precise Role

Abstract Background: Pancreatic cancer (PC) is one of the most fatal digestive system cancers. tripartite motif-29 (TRIM29) has been reported as oncogene in several human cancers. However, the precise role and underlying signal cascade of TRIM29 in PC progression remain unclear.Methods: Western blot, qRT-PCR and immunohistochemistry were used to analyze TRIM29 and Yes-associated protein 1 (YAP1) levels. CCK8 assays, EdU assays and flow cytometry were designed to explore the function and potential mechanism of TRIM29 and YAP1 in the proliferation of PC. Next, a nude mouse model of PC was established for validating the roles of TRIM29 and YAP1 in vivo. The relationship among TRIM29 and YAP1 was explored by co-immunoprecipitation and in vitro ubiquitination assay.Results: TRIM29 and YAP1 was significantly upregulated in PC patient samples, and TRIM29 expression was closely related to a malignant phenotype and poorer overall survival (OS) of PC patients. Functional assays revealed that TRIM29 knockdown suppresses cell growth, arrests cell cycle progression and promotes cell apoptosis of PC cells in vivo and in vitro. Furthermore, the rescue experiments demonstrated that TRIM29-induced proliferation is dependent on YAP1 in PC cells. Mechanistically, TRIM29 regulates YAP1 expression by directly binding to YAP1, and reduced its ubiquitination and degradation.Conclusion: Taken together, these results identify a novel mechanism used by PC growth, and provide insight regarding the role of TRIM29 in PC.

scholarly journals Trehalose Alleviates Crystalline Silica-Induced Pulmonary Fibrosis via Activation of the TFEB-Mediated Autophagy-Lysosomal System in Alveolar Macrophages

Cells ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 122 ◽  
Author(s):  
Xiu He ◽  
Shi Chen ◽  
Chao Li ◽  
Jiaqi Ban ◽  
Yungeng Wei ◽  
...  
Keyword(s):  
Pulmonary Fibrosis ◽  
Alveolar Macrophages ◽  
Nuclear Translocation ◽  
Protective Role ◽  
Crystalline Silica ◽  
Autophagic Flux ◽  
Lysosomal System

Silicosis is an occupational lung disease characterized by persistent inflammation and irreversible fibrosis. Crystalline silica (CS) particles are mainly phagocytized by alveolar macrophages (AMs), which trigger apoptosis, inflammation, and pulmonary fibrosis. Previously, we found that autophagy-lysosomal system dysfunction in AMs was involved in CS-induced inflammation and fibrosis. Induction of autophagy and lysosomal biogenesis by transcription factor EB (TFEB) nuclear translocation can rescue fibrotic diseases. However, the role of TFEB in silicosis is unknown. In this study, we found that CS induced TFEB nuclear localization and increased TFEB expression in macrophages both in vivo and in vitro. However, TFEB overexpression or treatment with the TFEB activator trehalose (Tre) alleviated lysosomal dysfunction and enhanced autophagic flux. It also reduced apoptosis, inflammatory cytokine levels, and fibrosis. Both pharmacologically inhibition of autophagy and TFEB knockdown in macrophages significantly abolished the antiapoptotic and anti-inflammatory effects elicited by either TFEB overexpression or Tre treatment. In conclusion, these results uncover a protective role of TFEB-mediated autophagy in silicosis. Our study suggests that restoration of autophagy-lysosomal function by Tre-induced TFEB activation may be a novel strategy for the treatment of silicosis.

Klotho ablation converts the biochemical and skeletal alterations in FGF23 (R176Q) transgenic mice to a Klotho-deficient phenotype

2009 ◽  
Vol 296 (1) ◽  
pp. E79-E88 ◽  
Author(s):  
Xiuying Bai ◽  
Qiu Dinghong ◽  
Dengshun Miao ◽  
David Goltzman ◽  
Andrew C. Karaplis
Keyword(s):  
Transgenic Mice ◽  
Cortical Bone ◽  
Related Factor ◽  
Signaling Mechanism ◽  
Dihydroxyvitamin D ◽  
Hypomorphic Allele ◽  
Calcium Phosphorus

Transgenic mice overexpressing fibroblast growth factor (FGF23) (R176Q) ( F Tg) exhibit biochemical {hypophosphatemia, phosphaturia, abnormal 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] metabolism} and skeletal (rickets and osteomalacia) abnormalities attributable to FGF23 action. In vitro studies now implicate the aging-related factor Klotho in the signaling mechanism of FGF23. In this study, we used a mouse genetic approach to validate in vivo the pivotal role of Klotho in the metabolic and skeletal derangements associated with FGF23 (R176Q) overexpression. To this end, we crossed mice heterozygous for the hypomorphic Klotho allele ( Kl+/−) to F Tg mice and obtained F Tg transgenic mice homozygous for the Kl-hypomorphic allele ( F Tg/ Kl−/−). Mice were killed on postnatal day 50, and serum and tissues were procured for analysis and comparison with F Tg, wild-type, and Kl−/− controls. From 4 wk onward, F Tg/ Kl−/− mice were clearly distinguishable from F Tg mice and exhibited a striking phenotypic resemblance to the Kl−/− controls. Serum analysis for calcium, phosphorus, parathyroid hormone, 1,25(OH)2D3, and alkaline phosphatase activity confirmed the biochemical similarity between the F Tg/ Kl−/− and Kl−/− mice and their distinctness from the F Tg controls. The characteristic skeletal changes associated with FGF23 (R176Q) overexpression were also dramatically reversed by the absence of Klotho. Hence the wide, unmineralized growth plates and the osteomalacic abnormalities apparent in trabecular and cortical bone were completely reversed in the F Tg/ Kl−/− mice. Nevertheless, independent actions of Klotho on bone were suggested as manifested by alterations in mineralized bone, and in cortical bone volume which were observed in both the Kl−/− and F Tr/ Kl−/− mutants. In summary, our findings substantiate in vivo the essential role of Klotho in the mechanism of action of FGF23 in view of the fact that Klotho ablation converts the biochemical and skeletal manifestations resulting from FGF23 overexpression to a phenotype consistent with Klotho deficiency.

scholarly journals BBX21, an Arabidopsis B-box protein, directly activates HY5 and is targeted by COP1 for 26S proteasome-mediated degradation

2016 ◽  
Vol 113 (27) ◽  
pp. 7655-7660 ◽  
Author(s):  
Dongqing Xu ◽  
Yan Jiang ◽  
Jigang Li ◽  
Fang Lin ◽  
Magnus Holm ◽  
...  
Keyword(s):  
Salt Tolerance ◽  
26S Proteasome ◽  
Light Signaling ◽  
Dependent Manner ◽  
Positive Regulator ◽  
Molecular Base ◽  
Precise Role

BBX21 (also known as SALT TOLERANCE HOMOLOG 2), a B-box (BBX)-containing protein, has been previously identified as a positive regulator of light signaling; however, the precise role of BBX21 in regulating seedling photomorphogenesis remains largely unclear. In this study, we report that CONSTITUTIVELY PHOTOMORPHOGENIC 1 (COP1) interacts with BBX21 in vivo and is able to ubiquitinate BBX21 in vitro. Thus, BBX21 is targeted for 26S proteasome-mediated degradation in dark-grown Arabidopsis seedlings in a COP1-dependent manner. Moreover, we show that BBX21 binds to the T/G-box in the ELONGATED HYPOCOTYL 5 (HY5) promoter and directly activates HY5 expression in the light. Transgenic seedlings overexpressing BBX21 exhibit dramatically shortened hypocotyls in the light, and this phenotype is dependent on a functional HY5. Taken together, our data suggest a molecular base underlying BBX21-mediated seedling photomorphogenesis, indicating that BBX21 is a pivotal component involved in the COP1-HY5 regulatory hub.

Role of C fibers in the inflammatory response to intratracheal lipopolysaccharide

1996 ◽  
Vol 271 (3) ◽  
pp. L425-L431 ◽  
Author(s):  
N. C. Long ◽  
C. W. Frevert ◽  
S. A. Shore
Keyword(s):  
Inflammatory Response ◽  
Alveolar Macrophages ◽  
Tumor Necrosis ◽  
Pulmonary Inflammation ◽  
Intratracheal Instillation ◽  
C Fibers ◽  
Vehicle Treatment ◽  
Necrosis Factor

We proposed that C fibers play a role in mediating the inflammatory response to the intratracheal instillation of lipopolysaccharaide (LPS), a purified form of endotoxin. To test this hypothesis, we compared the inflammatory response to intratracheal LPS (0.1-2.5 mg/kg) in rats whose C fibers had been destroyed by neonatal capsaicin treatment to the response seen in animals that were treated with vehicle. Three hours after the instillation of LPS, we assessed pulmonary inflammation by performing bronchoalveolar lavage (BAL) on the animals. We measured the number of neutrophils, the concentration of protein as an index of vascular permeability, and the concentration of tumor necrosis factor (TNF). Our results indicate that capsaicin treatment resulted in more neutrophils and higher levels of protein and TNF in the BAL fluid in response to intratracheal LPS, compared with vehicle treatment. Using cells from both groups of rats, we also assessed the production of inflammatory mediators by alveolar macrophages incubated with LPS (0.3-30 ng/ml) in vitro. We found a modest increase in the concentration of TNF and nitrite in the supernatant of macrophages collected from capsaicin-treated rats, in comparison with vehicle-treated animals. These results are consistent with the hypothesis that intrinsic differences in the sensitivity of alveolar macrophages of capsaicin and vehicle-treated animals contribute to the greater inflammatory response of capsaicin-treated rat to intratracheal LPS.

scholarly journals E3 ubiquitin ligase TRIM29 promotes pancreatic cancer growth and progression via stabilizing Yes-associated protein 1

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Xueqiang Deng ◽  
Xiaowei Fu ◽  
Hong Teng ◽  
Lu Fang ◽  
Bo Liang ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Cell Cycle Progression ◽  
Nude Mouse Model ◽  
Cycle Progression ◽  
Signal Cascade ◽  
The Relationship ◽  
Precise Role

Abstract Background Pancreatic cancer (PC) is one of the most fatal digestive system cancers. tripartite motif-29 (TRIM29) has been reported as oncogene in several human cancers. However, the precise role and underlying signal cascade of TRIM29 in PC progression remain unclear. Methods Western blot, qRT-PCR and immunohistochemistry were used to analyze TRIM29 and Yes-associated protein 1 (YAP1) levels. CCK8 assays, EdU assays and flow cytometry were designed to explore the function and potential mechanism of TRIM29 and YAP1 in the proliferation of PC. Next, a nude mouse model of PC was established for validating the roles of TRIM29 and YAP1 in vivo. The relationship among TRIM29 and YAP1 was explored by co-immunoprecipitation and in vitro ubiquitination assay. Results TRIM29 and YAP1 was significantly upregulated in PC patient samples, and TRIM29 expression was closely related to a malignant phenotype and poorer overall survival (OS) of PC patients. Functional assays revealed that TRIM29 knockdown suppresses cell growth, arrests cell cycle progression and promotes cell apoptosis of PC cells in vivo and in vitro. Furthermore, the rescue experiments demonstrated that TRIM29-induced proliferation is dependent on YAP1 in PC cells. Mechanistically, TRIM29 regulates YAP1 expression by directly binding to YAP1, and reduced its ubiquitination and degradation. Conclusion Taken together, these results identify a novel mechanism used by PC growth, and provide insight regarding the role of TRIM29 in PC.

Sign in / Sign up

Export Citation Format

Share Document