scholarly journals Enhanced AP-1 and NF-κB activities and stability of interleukin 8 (IL-8) transcripts are implicated in IL-8 mRNA superinduction in lung epithelial H292 cells

1998 ◽  
Vol 330 (1) ◽  
pp. 429-435 ◽  
Author(s):  
Thierry ROGER ◽  
A. Theo OUT ◽  
Naofumi MUKAIDA ◽  
Kouji MATSUSHIMA ◽  
M. Henk JANSEN ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Dna Binding ◽  
Mrna Expression ◽  
Gene Transcription ◽  
Molecular Mechanisms ◽  
Interleukin 8 ◽  
Mrna Levels ◽  
Tnf Α ◽  
Lung Epithelial ◽  
Inhibitor Of Protein Synthesis

Inhibition of protein synthesis may result in superinduction of short-lived transcripts and has been attributed variably to stabilization of transcripts and/or increased gene transcription. Little is known about the kinetics of these processes and relevant transcriptional elements have not been identified. In this study, we describe superinduction of interleukin 8 (IL-8) mRNA, an important inflammatory mediator, in lung epithelial-like H292 cells and identify the underlying molecular mechanisms and their kinetics. Cycloheximide (CHI, 10 μg/ml), an inhibitor of protein synthesis, maximally increased IL-8 mRNA levels 30-fold in H292 cells. Tumour necrosis factor α (TNF-α), which induced IL-8 mRNA 3-fold, synergized with CHI causing a 150-fold increase at 6 h. CHI early on increased the stability of IL-8 mRNA (from 40 min in cells cultured with medium to more than 4 h with CHI). CHI also increased transcription as shown by transfection with IL-8 promoter constructs. Truncated and mutated constructs identified NF-κB and AP-1 binding sites as primary cis-acting elements in IL-8 gene transcription and IL-8 mRNA superinduction. Electrophoretic mobility shift assays indicated that CHI increased NF-κB and prolonged AP-1 DNA-binding activities and that the synergism of TNF-α and CHI on IL-8 mRNA expression was paralleled by a further increase of AP-1 DNA-binding activity. This synergism was still noticed when 4 h elapsed between the addition of CHI and that of TNF-α. Taken together, our results indicate that CHI interferes with both post-transcriptional and transcriptional repressive mechanisms of IL-8 mRNA expression.

A direct requirement of nuclear factor-κB for suppression of apoptosis in ventricular myocytes

2000 ◽  
Vol 279 (3) ◽  
pp. H939-H945 ◽  
Author(s):  
Shareef Mustapha ◽  
Alla Kirshner ◽  
Danielle De Moissac ◽  
Lorrie A. Kirshenbaum
Keyword(s):  
Dna Binding ◽  
Gene Transcription ◽  
Ventricular Myocytes ◽  
Vital Staining ◽  
Fold Increase ◽  
Nuclear Factor Κb ◽  
Nuclear Factor ◽  
Cytoplasmic Factor ◽  
Tnf Α ◽  
Factor Α

Nuclear factor-κB (NF-κB) is a ubiquitously expressed cellular factor regulated by the cytoplasmic factor inhibitor protein κBα (IκBα). Activation of NF-κB by cytokines, including tumor necrosis factor-α (TNF-α), requires the phosphorylation and degradation of IκBα. An anti-apoptotic role for NF-κB has recently been suggested. In the present study, we ascertained whether death-promoting signals and apoptosis mediated by TNF-α are suppressed by NF-κB in postnatal ventricular myocytes. Stimulation of myocytes with TNF-α resulted in a 12.1-fold increase ( P < 0.01) in NF-κB-dependent gene transcription and DNA binding compared with controls. This was accompanied by a corresponding increase in the NF-κB target protein A20 as determined by Western blot analysis. Vital staining revealed that TNF-α was not cytotoxic to myocytes and did not provoke apoptosis. Adenovirus-mediated delivery of a nonphosphorylatable form of IκBα to inactivate NF-κB prevented TNF-α-stimulated NF-κB-dependent gene transcription and nuclear NF-κB DNA binding. Importantly, myocytes stimulated with TNF-α and defective for NF-κB activation resulted in a 2.2-fold increase ( P < 0.001) in apoptosis. To our knowledge, the data provide the first indication that a functional NF-κB signaling pathway is crucial for suppressing death-promoting signals mediated by TNF-α in ventricular myocytes.

Nitric oxide increases IL-8 gene transcription and mRNA stability to enhance IL-8 gene expression in lung epithelial cells

2004 ◽  
Vol 287 (4) ◽  
pp. L764-L773 ◽  
Author(s):  
Loretta Sparkman ◽  
Vijayakumar Boggaram
Keyword(s):  
Gene Expression ◽  
Nitric Oxide ◽  
Protein Kinase ◽  
Epithelial Cells ◽  
Gene Transcription ◽  
Mrna Stability ◽  
Inflammatory Responses ◽  
Lung Epithelial Cells ◽  
Mrna Levels ◽  
Lung Epithelial

Interleukin (IL)-8, a C-X-C chemokine, is a potent chemoattractant and an activator for neutrophils, T cells, and other immune cells. The airway and respiratory epithelia play important roles in the initiation and modulation of inflammatory responses via production of cytokines and surfactant. The association between elevated levels of nitric oxide (NO) and IL-8 in acute lung injury associated with sepsis, acute respiratory distress syndrome, respiratory syncytial virus infection in infants, and other inflammatory diseases suggested that NO may play important roles in the control of IL-8 gene expression in the lung. We investigated the role of NO in the control of IL-8 gene expression in H441 lung epithelial cells. We found that a variety of NO donors significantly induced IL-8 mRNA levels, and the increase in IL-8 mRNA was associated with an increase in IL-8 protein. NO induction of IL-8 mRNA was due to increases in IL-8 gene transcription and mRNA stability. NO induction of IL-8 mRNA levels was not inhibited by 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one and KT-5823, inhibitors of soluble guanylate cyclase and protein kinase G, respectively, and 8-bromo-cGMP did not increase IL-8 mRNA levels. This indicated that NO induces IL-8 mRNA levels independently of changes in the intracellular cGMP levels. NO induction of IL-8 mRNA was significantly reduced by inhibitors of extracellular regulated kinase and protein kinase C. IL-8 induction by NO was also reduced by hydroxyl radical scavengers such as dimethyl sulfoxide and dimethylthiourea, indicating the involvement of hydroxyl radicals in the induction process. NO induction of IL-8 gene expression could be a significant contributing factor in the initiation and induction of inflammatory response in the respiratory epithelium.

scholarly journals Transglutaminase 2 Up-Regulation Is Associated with Inflammatory Response in PBMC from Healthy Subjects with Hypovitaminosis D

2018 ◽  
Vol 6 (4) ◽  
pp. 103 ◽  
Author(s):  
Daniela Caccamo ◽  
Nadia Ferlazzo ◽  
Monica Currò ◽  
Sergio Ricca ◽  
Riccardo Ientile
Keyword(s):  
Vitamin D ◽  
Immune Response ◽  
Molecular Mechanisms ◽  
Nuclear Translocation ◽  
Transglutaminase 2 ◽  
Hypovitaminosis D ◽  
Mrna Levels ◽  
Vitamin D Status ◽  
Vitamin D Levels ◽  
Tnf Α

Recent evidence indicated that transglutaminase 2 (TG2) is involved in the adaptive immune response. Peripheral blood mononuclear cells (PBMC) have largely been used to characterize molecular mechanisms occurring in the activation of immune response. Given that the maintenance of immune system functions requires an optimal vitamin D status, we aimed to assess the involvement of TG2/NF-κB signaling in cytokine production in PBMC isolated from adult subjects with different vitamin D status. We observed TG2 up-regulation and a significant positive correlation between TG2 expression and tumor necrosis factor (TNF)-α mRNA levels in PBMC of recruited patients. The mRNA levels of TG2 and TNF-α were higher in PBMC of subjects having hypovitaminosis D, namely plasma 25(OH)vitamin D3 levels lower than 50 nmol/L, than in those with normal vitamin D levels. Moreover, NF-κB up-regulation and nuclear translocation were detected, concomitantly with TG2 as well as TNF-α increased expression, in PBMC of vitamin D-deficient subjects. The present findings confirm that an increase in TG2 expression exacerbates the activation of NF-κB and the production of pro-inflammatory cytokines, and suggest a link between vitamin D deficiency, TG2 up-regulation, and inflammation.

scholarly journals Hipertrofia muscular esquelética humana induzida pelo exercício físico/Exercise-induced human skeletal muscle hypertrophy

2011 ◽  
Vol 1 (2) ◽  
pp. 52-61
Author(s):  
Bernardo Neme Ide ◽  
Fernanda Lorenzi Lazarim ◽  
Denise Vaz de Macedo
Keyword(s):  
Protein Synthesis ◽  
Resistance Training ◽  
Signaling Pathways ◽  
Gene Transcription ◽  
Satellite Cells ◽  
Physical Training ◽  
Molecular Mechanisms ◽  
Enzyme Activation ◽  
Specific Gene ◽  
Adaptation Process

A resposta adaptativa ao treinamento físico é determinada pelo tipo, volume e frequência de aplicação dos estímulos, que ativam vias de sinalização distintas, a transcrição de genes específicos e posterior síntese protéica. O treinamento resistido está relacionado à ativação da enzima mTOR, proporcionada pelo hormônio IGF-1 e estimulada pela insulina, quando um carboidrato é consumido após a atividade física. Estas vias de sinalização levam à inibição da transcrição de genes relacionados à atrofia e aumento da síntese de proteínas contráteis e metabólicas, proporcionando um aumento da massa muscular, conhecido como hipertrofia. Atualmente, evidências sugerem que, além das sinalizações dos hormônios, os estímulos mecânicos (mecanotransdução) também podem influenciar a ativação gênica durante o processo hipertrófico. A ativação de células satélites, proporcionada pelo estresse mecânico, fatores de crescimento, radicais livres e citocinas é de suma importância para o crescimento muscular. Devido à relevância deste assunto, o presente trabalho traz uma revisão da literatura a respeito dos processos envolvidos na resposta hipertrófica, em decorrência do treinamento físico. Embora o processo hipertrófico seja bastante estudado, os mecanismos moleculares, tanto em nível gênico quanto protéico, envolvidos no processo adaptativo ainda não são totalmente compreendidos. Neste sentido, o avanço nas técnicas de biologia molecular como genômica, transcriptoma e proteômica abrem caminhos para futuras investigações nesta área.Palavras-chave: treino resistido, adaptações ao treinamento de força, células satélites, IGF-1, síntese protéica.The adaptation process to physical training is determined by the type, volume and frequency of stimulation, activating distinct signaling pathways, specific gene transcription and then protein synthesis. Resistance-training is related to mTOR enzyme activation induced by IGF-1 and stimulated by insulin when carbohydrates are consumed after physical activity. These pathways, may lead to the inhibition of gene transcription related to atrophy and the increment of contractile and metabolic protein synthesis causing an increase on muscle mass known as hypertrophy. Presently, there is evidence to suggest that besides hormone signaling pathways, mechanical stimulation (mechanotransduction) may also influence the gene activation during the hypertrophic process. The satellite cells activation induced by mechanical stress, growth factors, free radicals, and cytokines is crucial for muscle growth. Due to the importance of this topic, the present study, proposes a literature review about the processes related to the hypertrophic responses to physical training. Despite the frequent studies on the hypertrophic process, the molecular mechanisms (both at gene and protein levels) involved in the adaptation process is yet to be fully understood. Thus, advances in molecular biology techniques such as genomic, transcriptoma and proteomic open ways for future investigations in this area.Key words: Resistance-training, strength training adaptations, satellite cells, IGF-1, protein synthesis.

scholarly journals TheBDKRB2 +9/-9 Polymorphisms Influence Pro-Inflammatory Cytokine Levels in Knee Osteoarthritis by Altering TLR-2 Expression: Clinical and in Vitro Studies

2016 ◽  
Vol 38 (3) ◽  
pp. 1245-1256 ◽  
Author(s):  
Shuo Chen ◽  
Lei Zhang ◽  
Ruonan Xu ◽  
Yunfan Ti ◽  
Yunlong Zhao ◽  
...  
Keyword(s):  
Knee Osteoarthritis ◽  
Inflammatory Cytokine ◽  
Molecular Mechanisms ◽  
Enzyme Linked Immunosorbent Assay ◽  
Mrna Levels ◽  
Knee Oa ◽  
Tnf Α ◽  
Cytokine Levels ◽  
Underlying Mechanisms

Background/Aims: The bradykinin B2 receptor (BDKRB2) +9/-9 gene polymorphisms have been shown to be associated with the susceptibility and severity of osteoarthritis (OA); however, the underlying mechanisms are unclear. In this study, we investigated the correlation between the BDKRB2 +9/-9 polymorphisms and pro-inflammatory cytokine levels in OA and the molecular mechanisms involved. Methods: A total of 156 patients with primary knee OA and 121 healthy controls were enrolled. The BDKRB2 +9/-9 polymorphisms were genotyped. The tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and IL-8 levels were determined using Enzyme-linked immunosorbent assay (ELISA). The toll-like receptor (TLR)-2 and TLR-4 mRNA levels were determined by quantitative real-time PCR. The basal and bradykinin-stimulated pro-inflammatory cytokine secretion in human OA synoviocytes and the involvement of TLR-2 and mitogen-activated protein kinases (MAPKs) were investigated. Results: The presence of -9 bp genotype is associated with higher TNF-α, IL-6, and IL-8 levels and higher TLR-2 expression in OA patients. The basal and bradykinin-induced TLR-2 expressions in human OA synoviocytes were significantly reduced by specific inhibitors of p38, JNK1/2, and ERK1/2. Both the B2 receptor antagonist MEN16132 and TLR-2 silencing inhibited IL-6 and IL-8 secretion in human OA synoviocytes. Conclusion: The data suggested that the BDKRB2 +9/-9 polymorphisms influence pro-inflammatory cytokine levels in knee osteoarthritis by altering TLR-2 expression.

scholarly journals Functional Modification of Pituitary Somatotropes in the Aromatase Knockout Mouse and the Effect of Estrogen Replacement

Endocrinology ◽  
2004 ◽  
Vol 145 (2) ◽  
pp. 604-612 ◽  
Author(s):  
Ming Yan ◽  
Margaret E. E. Jones ◽  
Maria Hernandez ◽  
Dongling Liu ◽  
Evan R. Simpson ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Molecular Mechanisms ◽  
Somatostatin Receptors ◽  
Mrna Levels ◽  
Gene Encoding ◽  
Gh Secretion ◽  
Ghrh Receptor ◽  
Elevated Expression ◽  
Cyp19 Gene

Abstract Available data on the influence of estradiol (E2) on GH levels remains controversial. A factor contributing to this uncertainty is a lack of knowledge of both E2 action on somatotropes as well as the molecular mechanisms involved. In this study we investigated gene expression implicated in GH secretion in somatotropes derived from female aromatase knockout (ArKO) mice. In these mice E2 production is blocked due to disruption of the Cyp19 gene encoding aromatase, the enzyme responsible for estrogen biosynthesis. The effect of E2 replacement was also studied by in vivo treatment of mice with E2 for 3 wk. It was demonstrated that somatotropes from ArKO mice had a low expression of GH, GH secretagogue receptor, GHRH receptor (GHRH-R), and pituitary-specific transcription factor (Pit-1). On the other hand, the somatotropes exhibited elevated expression of somatostatin receptors (sst1–5). Overall, these effects resulted in a reduction in GH secretion. E2 replacement increased GHRH-R, Pit-1, and GH mRNA levels to 185%, 193%, and 157% and reduced the levels of sst1, sst2, sst4, and sst5 mRNA expression in ArKO mice, respectively. E2 replacement did not affect the levels of pituitary estrogen (α and β) and androgen receptor mRNA expression. It is concluded that the expression of important genes involved in GH synthesis in somatotropes of the female ArKO mouse are functionally down-regulated, and such a down-regulation is reversed to normal levels by E2 replacement. The levels of GH secretagogue receptor, GHRH-R, and Pit-1 mRNA expression were also reduced, and sst1 and sst3 mRNA expression enhanced in aging ArKO and wild-type mice, resulting in a decrease in GH mRNA expression. It is suggested that aging is another important impact factor for the pituitary expression and regulation of GH mRNA in female mice.

scholarly journals Sex Differences in Estrogen-Dependent Transcription of Gonadotropin-Releasing Hormone (GnRH) Gene Revealed in GnRH Transgenic Mice

Endocrinology ◽  
2003 ◽  
Vol 144 (8) ◽  
pp. 3351-3358 ◽  
Author(s):  
Niren R. Thanky ◽  
Ruth Slater ◽  
Allan E. Herbison
Keyword(s):  
Transgenic Mice ◽  
Mrna Expression ◽  
Gene Transcription ◽  
Transgene Expression ◽  
Gonadal Steroids ◽  
Critical Element ◽  
Sexually Dimorphic ◽  
Mrna Levels ◽  
Estrogen Replacement

Abstract The mechanisms through which gonadal steroids exert feedback actions on the activity of the GnRH neurons are not understood. Using a series of GnRH-LacZ transgenic mice we have examined the manner in which gonadal steroids suppress GnRH mRNA expression in male and female mice. The long-term gonadectomy of 5.5-GNZ-3.5 transgenic mice resulted in significant increases in cellular GnRH mRNA expression (P &lt; 0.05) and plasma LH concentrations (P &lt; 0.01) in both sexes. However, cellular levels of LacZ mRNA and β-galactosidase, which provide an index of GnRH gene transcription, were only elevated in males after gonadectomy. This sexually differentiated response was also observed in mice gonadectomized for 2 wk. Estrogen replacement in gonadectomized males returned transgene expression to intact levels. Experiments in transgenic mice with 3′ and 5′ deleted GnRH-LacZ constructs revealed that the suppressive influence of estrogen on LacZ transcription in the male required a critical element located between −5.2 and −1.7 kb of the GnRH promoter. These studies show that the suppression of GnRH mRNA expression by estrogen in the male involves a decrease in GnRH gene transcription that is dependent on a distal GnRH promoter element. The same mechanism does not exist in females, indicating that gonadal steroids suppress GnRH mRNA levels in a sexually dimorphic manner.

p29ING4 Regulates the Production of Pro-Angiogenic Molecules by Human Myeloma Cells in Normoxic and Hypoxic Conditions Being Involved in Myeloma-Induced Angiogenesis.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 515-515
Author(s):  
Sara Tagliaferri ◽  
Francesca Morandi ◽  
Paolo Lunghi ◽  
Simona Colla ◽  
Mirca Lazzaretti ◽  
...  
Keyword(s):  
Tumor Suppressor ◽  
Mrna Expression ◽  
Real Time ◽  
Real Time Pcr ◽  
Interleukin 8 ◽  
Mrna Levels ◽  
Quantitative Real Time Pcr ◽  
Angiogenic Switch ◽  
Hypoxic Conditions

Abstract Multiple myeloma (MM) cells produce several angiogenic molecules as VEGF, Angiopoietin-1 (Ang-1), interleukin-8 (IL-8) and osteopontin (OPN), however the molecular mechanisms underlying the angiogenic switch are not completely elucidated. The candidate tumor suppressor gene inhibitor of growth family member 4 (p29ING4) has been recently implicated in solid tumors as a repressor of angiogenesis and tumor growth through the suppression of angiogenic related molecules including interleukin-8 (IL-8) and the hypoxia inducible factor (HIF)-1 alpha. In this study we investigate the potential involvement of p29ING4 in the angiogenic switch in MM. First using quantitative real time PCR we compared p29ING4 with VEGF, Ang-1, IL-8 and OPN mRNA levels in eight human myeloma cell lines (HMCLs). A significantly negative correlation was observed between ING4 and IL-8 and a trend of correlation with OPN. Following we transfected HMCLs JJN3, OPM-2 and RPMI-8226 with specific siRNA to completely block the expression of p29ING4 checking the effect on the expression and production of the myeloma-related angiogenic molecules VEGF, Ang-1, IL-8 and OPN by quantitative real time PCR and ELISA assay. p29ING4 suppression in HMCLs did not affect VEGF and Ang-1 production but induced a strong up-regulation of IL-8 mRNA and IL-8 protein secretion. Similarly an induction of OPN mRNA expression as well as OPN secretion was induced by siRNA anti-p29ING4. Moreover conditioned media of HMCLs transfected with siRNA anti p29ING4 significantly increased vessel formation in an experimental in vitro model of angiogenesis (ANGIO kit) as compared to controls. Further we investigate the role of p29ING4 in the production of angiogenic molecule by MM cells in hypoxic condition compared to normoxic one as well as its potential relationship with HIF-1alpha system. Hypoxia induced HIF-1alpha expression at nuclear level and its activity in HMCLs and p29ING4 suppression by siRNA further induced HIF-1alpha transcriptional activity with an increase of its target gene Nip-3 in HMCLs. In turn the block of HIF1-alpha by specific siRNA up-regulated p29ING4 and suppressed IL-8 and OPN mRNA expression by HMCLs suggesting a relationship between p29ING4 and HIF-1alpha activity. These in vitro observations have been extended in vivo by the finding of a significant correlation between bone marrow (BM) plasma IL-8 levels and p29ING4 mRNA expression in purified MM cells obtained from 40 newly diagnosed MM patients (R=−0.58 Spearman’s 2-tailed test: p=0.04), consistently MM patients with higher BM IL-8 levels have a significantly lower p29ING4 mRNA levels. Similarly MM patients positive for OPN expression with high OPN BM levels had a significant lower p29ING4 levels (p=0.02). Finally we found that MM patients with high microvalscular density (MVD&gt;30) have significant lower p29ING4 levels as compared to those with low MVD (&lt;30) (p=0.04) and that MM patients with histological high grade had significant lower p29ING4 mRNA levels (Mann-Whitney 2-tailed: p=0.05). In conclusion, our data indicate that the tumor suppressor p29ING4 regulate the production of angiogenic molecules by MM cells both in normoxic and hypoxic conditions being involved in MM-induced angiogenesis and potentially in tumor progression.

scholarly journals Tumor Necrosis Factor-α Stimulates Lactate Dehydrogenase A Expression in Porcine Cultured Sertoli Cells: Mechanisms of Action

Endocrinology ◽  
1999 ◽  
Vol 140 (7) ◽  
pp. 3054-3062 ◽  
Author(s):  
Fayçal Boussouar ◽  
Renée Grataroli ◽  
Jingwei Ji ◽  
Mohamed Benahmed
Keyword(s):  
Mrna Expression ◽  
Gene Transcription ◽  
Sertoli Cells ◽  
Tumor Necrosis ◽  
Actinomycin D ◽  
Lactate Production ◽  
Mrna Levels ◽  
Kinase C ◽  
Factor Α ◽  
Necrosis Factor

Abstract In the present study, we investigated the regulatory action of tumor necrosis factor-α (TNFα) on lactate dehydrogenase A (LDH A), a key enzyme involved in lactate production. To this end, use was made of a primary culture system of porcine testicular Sertoli cells. TNFα stimulated LDH A messenger RNA (mRNA) expression in a dose (ED50 = 2.5 ng/ml; 0.1 nm TNFα)-dependent manner. This stimulatory effect was time dependent, with an effect detected after 6 h of TNFα treatment and maximal after 48 h of exposition (5-fold; P &lt; 0.001). The direct effect of TNFα on LDH A mRNA could not be accounted for by an increase in mRNA stability (half-life = 9 h), but was probably due to an increase in LDH A gene transcription. Inhibitors of protein synthesis (cycloheximide), gene transcription (actinomycin D and dichlorobenzimidazole riboside), tyrosine kinase (genistein), and protein kinase C (bisindolylmaleimide) abrogated completely (actinomycin D, dichlorobenzimidazole riboside, cycloheximide, and genistein) or partially (bisindolylmaleimide) TNFα-induced LDH A mRNA expression. These observations suggest that the stimulatory effect of TNFα on LDH A mRNA expression requires protein synthesis and may involve a protein tyrosine kinase and protein kinase C. In addition, we report that LDH A mRNA levels were increased in Sertoli cells treated with FSH. However, although the cytokine enhances LDH A mRNA levels through increased gene transcription, the hormone exerts its stimulatory action through an increase in LDH A mRNA stability. The regulatory actions of the cytokine and the hormone on LDH A mRNA levels and therefore on lactate production may operate in the context of the metabolic cooperation between Sertoli and postmeiotic germ cells in the seminiferous tubules.

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