scholarly journals Syk Plays a Critical Role in the Expression and Activation of IRAK1 in LPS-Treated Macrophages

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Jae Gwang Park ◽  
Young-Jin Son ◽  
Byong Chul Yoo ◽  
Woo Seok Yang ◽  
Ji Hye Kim ◽  
...  
Keyword(s):  
Tyrosine Kinase ◽  
Protein Tyrosine Kinase ◽  
Interleukin 1 ◽  
Mrna Level ◽  
Critical Role ◽  
Primary Response ◽  
Transcriptional Level ◽  
Mrna Levels ◽  
Treatment Conditions ◽  
Lps Treatment

To address how interleukin-1 receptor-associated kinase 1 (IRAK1) is controlled by other enzymes activated by toll-like receptor (TLR) 4, we investigated the possibility that spleen tyrosine kinase (Syk), a protein tyrosine kinase that is activated at an earlier stage during TLR4 activation, plays a central role in regulating the functional activation of IRAK1. Indeed, we found that overexpression of myeloid differentiation primary response gene 88 (MyD88), an adaptor molecule that drives TLR signaling, induced IRAK1 expression and that piceatannol, a Syk inhibitor, successfully suppressed the MyD88-dependent upregulation of IRAK1 under LPS treatment conditions. Interestingly, in Syk-knockout RAW264.7 cells, IRAK1 activity was almost completely blocked after LPS treatment, while providing a Syk-recovery gene to the knockout cells successfully restored IRAK1 expression. According to our measurements of IRAK1 mRNA levels, the transcriptional upregulation of IRAK1 was induced by LPS treatment between 4 and 60 min, and this can be suppressed in Syk knockout cells, providing an effect similar that that seen under piceatannol treatment. The overexpression of Syk reverses this effect and leads to a significantly higher IRAK1 mRNA level. Collectively, our results strongly suggest that Syk plays a critical role in regulating both the activity and transcriptional level of IRAK1.

scholarly journals Oral Metformin Treatment Counteracts Adipoinsular Axis Dysfunction in Hypothalamic Obese Rats

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Daniel Castrogiovanni ◽  
Luisina Ongaro ◽  
Guillermina Zuburía ◽  
Andrés Giovambattista ◽  
Eduardo Spinedi
Keyword(s):  
Low Dose ◽  
Cushing Syndrome ◽  
Mrna Level ◽  
Mrna Levels ◽  
Metformin Treatment ◽  
Treatment Conditions ◽  
Catch Up ◽  
Visceral Adipose ◽  
And Control ◽  
Lps Treatment

Rats neonatally treated with monosodium L-glutamate (MSG) are deeply dysfunctional in adulthood. We explored the effect of an oral low dose of metformin treatment in male MSG rats on adipoinsular axis and visceral adipose tissue (VAT) dysfunctions, in both basal (nonfasting) and endotoxemia conditions. MSG rats, treated or not treated with metformin (30 days prior to experimentation), and control litter-mates (CTR) were studied at 90 days of age. Peripheral concentrations of glucose, lipids, and hormones were determined in basal and post-lipopolysaccharide (LPS) treatment conditions. Food intake and body weight (BW) were recorded and VAT mass and leptin mRNA levels were evaluated. Data indicated that MSG rats were lighter and displayed hypercorticosteronemia, hypophagia, adipoinsular axis hyperactivity, and enhanced VAT mass associated with an increased leptin gene expression. Interestingly, metformin-treated MSG rats corrected BW catch-up and counteracted VAT (mass and leptin mRNA level) and adipoinsular axis (basal and post-LPS) dysfunctions. Thus metformin treatment in MSG rats is able to correct several VAT and metabolic-endocrine dysfunctions. Our study suggests that a low-dose metformintherapy is effective to correct, at least in part, adipoinsular axis dysfunction in hypertrophic obese phenotypes, such as that of the human Cushing syndrome.

Protein-tyrosine Kinase p72 syk Is Activated by Platelet Activating Factor in Platelets

1994 ◽  
Vol 72 (06) ◽  
pp. 937-941 ◽  
Author(s):  
Karim Rezaul ◽  
Shigeru Yanagi ◽  
Kiyonao Sada ◽  
Takanobu Taniguchi ◽  
Hirohei Yamamura
Keyword(s):  
Tyrosine Kinase ◽  
Tyrosine Phosphorylation ◽  
Protein Tyrosine Kinase ◽  
Kinase Inhibitor ◽  
Critical Role ◽  
Platelet Activating Factor ◽  
Kinase Assay ◽  
Potential Candidate ◽  
Protein Tyrosine ◽  
Induced Aggregation

SummaryIt has been demonstrated that activation of platelets by platelet-activating factor (PAF) results in a dramatic increase in tyrosine phosphorylation of several cellular proteins. We report here that p72 syk is a potential candidate for the protein-tyrosine phosphorylation following PAF stimulation in porcine platelets. Immunoprecipitation kinase assay revealed that PAF stimulation resulted in a rapid activation of p72 syk which peaked at 10 s. The level of activation was found to be dose dependent and could be completely inhibited by the PAF receptor antagonist, CV3988. Phosphorylation at the tyrosine residues of p72 syk coincided with activation of yllsyk. Pretreatment of platelets with aspirin and apyrase did not affect PAF induced activation of p72 syk .Furthermore, genistein, a potent protein-tyrosine-kinase inhibitor, diminished PAF-induced p72 syk activation and Ca2+ mobilization as well as platelet aggregation. These results suggest that p72 syk may play a critical role in PAF-induced aggregation, possibly through regulation of Ca2+ mobilization.

scholarly journals IL-1β dysregulates cGMP signaling in the newborn lung

2020 ◽  
Vol 319 (1) ◽  
pp. L21-L34
Author(s):  
Ying Zhong ◽  
Kristina Bry ◽  
Jesse D. Roberts
Keyword(s):  
Mrna Expression ◽  
Transforming Growth Factor ◽  
Critical Role ◽  
Lung Epithelial Cells ◽  
Lung Fibroblasts ◽  
Transcriptional Level ◽  
Mrna Levels ◽  
Iκb Kinase ◽  
Primary Mouse ◽  
Cgmp Signaling

Cyclic guanosine monophosphate (cGMP) signaling is an important regulator of newborn lung function and development. Although cGMP signaling is decreased in many models of newborn lung injury, the mechanisms are poorly understood. We determined how IL-1β regulates the expression of the α1-subunit of soluble guanylate cyclase (sGCα1), a prime effector of pulmonary cGMP signaling. Physiologic levels of IL-1β were discovered to rapidly decrease sGCα1 mRNA expression in a human fetal lung fibroblast cell line (IMR-90 cells) and protein levels in primary mouse pup lung fibroblasts. This sGCα1 expression inhibition appeared to be at a transcriptional level; IL-1β treatment did not alter sGCα1 mRNA stability, although it reduced sGCα1 promoter activity. Transforming growth factor-β (TGFβ)-activated kinase-1 (TAK1) was determined to be required for IL-1β’s regulation of sGCα1 expression; TAK1 knockdown protected sGCα1 mRNA expression in IL-1β-treated IMR-90 cells. Moreover, heterologously expressed TAK1 was sufficient to decrease sGCα1 mRNA levels in those cells. Nuclear factor-κB (NF-κB) signaling played a critical role in the IL-1β-TAK1-sGCα1 regulatory pathway; chromatin immunoprecipitation studies demonstrated enhanced activated NF-κB subunit (RelA) binding to the sGCα1 promoter after IL-1β treatment unless treated with an IκB kinase-2 inhibitor. Also, this NF-κB signaling inhibition protected sGCα1 expression in IL-1β-treated fibroblasts. Lastly, using transgenic mice in which active IL-1β was conditionally expressed in lung epithelial cells, we established that IL-1β expression is sufficient to stimulate TAK1 and decrease sGCα1 protein expression in the newborn lung. Together these results detail the role and mechanisms by which IL-1β inhibits cGMP signaling in the newborn lung.

scholarly journals Reduced miR-26b Expression in Megakaryocytes and Platelets Contributes to Elevated Level of Platelet Activation Status in Sepsis

2020 ◽  
Vol 21 (3) ◽  
pp. 866 ◽  
Author(s):  
Bernadett Szilágyi ◽  
Zsolt Fejes ◽  
Szilárd Póliska ◽  
Marianna Pócsi ◽  
Zsolt Czimmerer ◽  
...  
Keyword(s):  
Platelet Activation ◽  
Mirna Expression ◽  
Mrna Level ◽  
Severe Infection ◽  
Mrna Levels ◽  
Rna Seq ◽  
Calpain Inhibition ◽  
The Impact ◽  
Lps Treatment ◽  
Activation Status

In sepsis, platelets may become activated via toll-like receptors (TLRs), causing microvascular thrombosis. Megakaryocytes (MKs) also express these receptors; thus, severe infection may modulate thrombopoiesis. To explore the relevance of altered miRNAs in platelet activation upon sepsis, we first investigated sepsis-induced miRNA expression in platelets of septic patients. The effect of abnormal Dicer level on miRNA expression was also evaluated. miRNAs were profiled in septic vs. normal platelets using TaqMan Open Array. We validated platelet miR-26b with its target SELP (P-selectin) mRNA levels and correlated them with clinical outcomes. The impact of sepsis on MK transcriptome was analyzed in MEG-01 cells after lipopolysaccharide (LPS) treatment by RNA-seq. Sepsis-reduced miR-26b was further studied using Dicer1 siRNA and calpain inhibition in MEG-01 cells. Out of 390 platelet miRNAs detected, there were 121 significantly decreased, and 61 upregulated in sepsis vs. controls. Septic platelets showed attenuated miR-26b, which were associated with disease severity and mortality. SELP mRNA level was elevated in sepsis, especially in platelets with increased mean platelet volume, causing higher P-selectin expression. Downregulation of Dicer1 generated lower miR-26b with higher SELP mRNA, while calpeptin restored miR-26b in MEG-01 cells. In conclusion, decreased miR-26b in MKs and platelets contributes to an increased level of platelet activation status in sepsis.

scholarly journals VHL tumor suppressor regulates Cl−/HCO3− exchange and Na+/H+ exchange activities in renal carcinoma cells

2001 ◽  
Vol 5 (3) ◽  
pp. 119-128 ◽  
Author(s):  
S. ANANTH KARUMANCHI ◽  
LIANWEI JIANG ◽  
BERTRAND KNEBELMANN ◽  
ALAN K. STUART-TILLEY ◽  
SETH L. ALPER ◽  
...  
Keyword(s):  
Tumor Suppressor ◽  
Mrna Level ◽  
Critical Role ◽  
Suppressor Gene ◽  
Mrna Levels ◽  
Differential Display Pcr ◽  
Von Hippel Lindau ◽  
Acid Load ◽  
Vhl Disease ◽  
Exchange Activity

Mutations in the von Hippel-Lindau (VHL) tumor suppressor gene are thought to play a critical role in the pathogenesis of both sporadic and VHL disease-associated clear-cell renal carcinomas (RCC). Differential display-PCR identified the AE2 anion exchanger as a candidate VHL target gene. AE2 mRNA and polypeptide levels were approximately threefold higher in 786-O VHL cells than in 786-O Neo cells. In contrast, Cl−/HCO3− exchange activity in 786-O VHL cells was 50% lower than in 786-O Neo cells. Since resting intracellular pH (pHi) values were indistinguishable, we postulated that Na+/H+ exchange activity (NHE) might be similarly reduced in 786-O VHL cells. NHE-mediated pHi recovery from acid load was less than 50% that in 786-O Neo cells, whereas hypertonicity-stimulated, amiloride-sensitive NHE was indistinguishable in the two cell lines. The NHE3 mRNA level was higher in 786-O VHL than 786-O Neo cells, but NHE1 mRNA levels did not differ. AE2 and NHE3 are the first transcripts reported to be upregulated by pVHL. Elucidation of mechanisms responsible for downregulation of both ion exchange activities will require further investigation.

scholarly journals Gene expression of lipid storage-related enzymes in adipose tissue of the genetically obese Zucker rat. Co-ordinated increase in transcriptional activity and potentiation by hyperinsulinaemia

1992 ◽  
Vol 281 (3) ◽  
pp. 607-611 ◽  
Author(s):  
I Dugail ◽  
A Quignard-Boulangé ◽  
X Le Liepvre ◽  
B Ardouin ◽  
M Lavau
Keyword(s):  
Adipose Tissue ◽  
Mrna Level ◽  
Lipid Storage ◽  
Zucker Rats ◽  
Transcriptional Level ◽  
Transcription Rate ◽  
Mrna Levels ◽  
Zucker Rat ◽  
Obese Zucker Rat ◽  
Obese Rats

The genetically obese Zucker rat displays excessive fat storage capacity which is due to a tissue-specific increase in the activities of a number of lipid storage-related enzymes in adipose tissue. The aim of this study was to investigate the molecular mechanism responsible for this phenomenon. Lean (Fa/fa) and obese (fa/fa) Zucker rats were studied during the early stages of adipose tissue overdevelopment, both before (at 16 days of age) and after (at 30 days of age) the emergence of hyperinsulinaemia, in order to delineate the effects of the fatty genotype independently of those of hyperinsulinaemia. Lipoprotein lipase (LPL), glycerophosphate dehydrogenase (GPDH), glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and malic enzyme (ME) mRNA levels in the adipose tissue of lean and obese rats were assessed by Northern blot analysis, and the relative transcription rates of the corresponding genes were compared in the two genotypes by a nuclear run-on assay. In normoinsulinaemic 16-day-old pre-obese rats, mRNA levels were increased over control values (LPL, 5-fold; ME, 2-fold; GAPDH, 3-fold), in close correlation with genotype-mediated differences in enzyme activities. Stimulation of the transcription rates of the ME and GAPDH genes was observed in obese rats, which could fully account for differences in steady-state mRNA levels. At this age, GPDH activity, mRNA level and transcription rate were similar in the two genotypes. In hyperinsulinaemic 30-day-old obese rats, a 6-7-fold increase in both mRNA and the transcription rate of GPDH emerged, together with an amplification of the genotype-mediated differences observed in younger animals (GAPDH, 6-fold; ME, 7.9-fold; LPL, 10-fold). These results demonstrate that the obese genotype exerts a co-ordinated control on the expression of these genes in adipose tissue, mainly at the transcriptional level. This genotype effect is greatly amplified by the development of hyperinsulinaemia.

scholarly journals Control of Nipah Virus Infection in Mice by the Host Adaptors Mitochondrial Antiviral Signaling Protein (MAVS) and Myeloid Differentiation Primary Response 88 (MyD88)

2019 ◽  
Vol 221 (Supplement_4) ◽  
pp. S401-S406 ◽  
Author(s):  
Mathieu Iampietro ◽  
Noemie Aurine ◽  
Kevin P Dhondt ◽  
Claire Dumont ◽  
Rodolphe Pelissier ◽  
...  
Keyword(s):  
Interleukin 1 ◽  
Critical Role ◽  
Nipah Virus ◽  
Primary Response ◽  
Myeloid Differentiation ◽  
Type I ◽  
Antiviral Signaling ◽  
Signaling Protein ◽  
Mitochondrial Antiviral Signaling ◽  
Mitochondrial Antiviral Signaling Protein

Abstract Interferon (IFN) type I plays a critical role in the protection of mice from lethal Nipah virus (NiV) infection, but mechanisms responsible for IFN-I induction remain unknown. In the current study, we demonstrated the critical role of the mitochondrial antiviral signaling protein signaling pathway in IFN-I production and NiV replication in murine embryonic fibroblasts in vitro, and the redundant but essential roles of both mitochondrial antiviral signaling protein and myeloid differentiation primary response 88 adaptors, but not toll/interleukin-1 receptor/resistance [TIR] domain–containing adaptor–inducing IFN-β (TRIF), in the control of NiV infection in mice. These results reveal potential novel targets for antiviral intervention and help in understanding NiV immunopathogenesis.

Src protein tyrosine kinase family and acute inflammatory responses

2006 ◽  
Vol 291 (2) ◽  
pp. L129-L141 ◽  
Author(s):  
Daisuke Okutani ◽  
Monika Lodyga ◽  
Bing Han ◽  
Mingyao Liu
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Tyrosine Kinase ◽  
Reperfusion Injury ◽  
Protein Tyrosine Kinase ◽  
Inflammatory Responses ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Critical Role ◽  
Protein Tyrosine

Acute inflammatory responses are one of the major underlying mechanisms for tissue damage of multiple diseases, such as ischemia-reperfusion injury, sepsis, and acute lung injury. By use of cellular and molecular approaches and transgenic animals, Src protein tyrosine kinase (PTK) family members have been identified to be essential for the recruitment and activation of monocytes, macrophages, neutrophils, and other immune cells. Src PTKs also play a critical role in the regulation of vascular permeability and inflammatory responses in tissue cells. Importantly, animal studies have demonstrated that small chemical inhibitors for Src PTKs attenuate tissue injury and improve survival from a variety of pathological conditions related to acute inflammatory responses. Further investigation may lead to the clinical application of these inhibitors as drugs for ischemia-reperfusion injury (such as stroke and myocardial infarction), sepsis, acute lung injury, and multiple organ dysfunction syndrome.

scholarly journals Transfection of Syk protein tyrosine kinase reconstitutes high affinity IgE receptor-mediated degranulation in a Syk-negative variant of rat basophilic leukemia RBL-2H3 cells.

1996 ◽  
Vol 184 (1) ◽  
pp. 71-79 ◽  
Author(s):  
J Zhang ◽  
E H Berenstein ◽  
R L Evans ◽  
R P Siraganian
Keyword(s):  
Tyrosine Kinase ◽  
Histamine Release ◽  
Phospholipase C ◽  
Tyrosine Phosphorylation ◽  
Protein Tyrosine Kinase ◽  
Immunoglobulin E ◽  
Critical Role ◽  
Protein Tyrosine ◽  
High Affinity ◽  
Phospholipase C Gamma

Aggregation of the high affinity receptor for immunoglobulin E (Fc epsilon RI) on mast cells results in rapid tyrosine phosphorylation and activation of Syk, a cytoplasmic protein tyrosine kinase. To examine the role of Syk in the Fc epsilon RI signaling pathway, we identified a variant of RBL-2H3 cells that has no detectable Syk by immunoblotting and by in vitro kinase reactions. In these Syk-deficient TB1A2 cells, aggregation of Fc epsilon RI induced no histamine release and no detectable increase in total cellular protein tyrosine phosphorylation. However, stimulation of these cells with the calcium ionophore did induce degranulation. Fc epsilon RI aggregation induced tyrosine phosphorylation of the beta and gamma subunits of the receptor, but no increase in the tyrosine phosphorylation of phospholipase C-gamma 1 and phospholipase C-gamma 2 and no detectable increase in intracellular free Ca2+ concentration. By transfection, cloned lines were established with stable expression of Syk. In these reconstituted cells, Fc epsilon RI aggregation induced tyrosine phosphorylation of phospholipase C-gamma 1 and phospholipase C-gamma 2, an increase in intracellular free Ca2+ and histamine release. These results demonstrate that Syk plays a critical role in the early Fc epsilon RI-mediated signaling events. It further demonstrates that Syk activation occurs downstream of receptor phosphorylation, but upstream of most of the Fc epsilon RI-mediated protein tyrosine phosphorylations.

scholarly journals Acid secretion by mitochondrion-rich cells of medaka (Oryzias latipes) acclimated to acidic freshwater

2012 ◽  
Vol 302 (2) ◽  
pp. R283-R291 ◽  
Author(s):  
Chia-Cheng Lin ◽  
Li-Yih Lin ◽  
Hao-Hsuan Hsu ◽  
Violette Thermes ◽  
Patrick Prunet ◽  
...  
Keyword(s):  
Acid Secretion ◽  
Mrna Level ◽  
Critical Role ◽  
Mrna Levels ◽  
Selective Electrode ◽  
Embryonic Skin ◽  
Apical Membranes ◽  
Acid Acclimation ◽  
Electrode Technique

In the present study, medaka embryos were exposed to acidified freshwater (pH 5) to investigate the mechanism of acid secretion by mitochondrion-rich (MR) cells in embryonic skin. With double or triple in situ hybridization/immunocytochemistry, the Na+/H+ exchanger 3 (NHE3) and H+-ATPase were localized in two distinct subtypes of MR cells. NHE3 was expressed in apical membranes of a major proportion of MR cells, whereas H+-ATPase was expressed in basolateral membranes of a much smaller proportion of MR cells. Gill mRNA levels of NHE3 and H+-ATPase and the two subtypes of MR cells in yolk sac skin were increased by acid acclimation; however, the mRNA level of NHE3 was remarkably higher than that of H+-ATPase. A scanning ion-selective electrode technique was used to measure H+, Na+, and NH4+ transport by individual MR cells in larval skin. Results showed that Na+ uptake and NH4+ excretion by MR cells increased after acid acclimation. These findings suggested that the NHE3/Rh glycoprotein-mediated Na+ uptake/NH4+ excretion mechanism plays a critical role in acidic equivalent (H+/NH4+) excretion by MR cells of the freshwater medaka.

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