Modulation of glucocorticoid receptor expression, inflammation, and cell apoptosis in septic guinea pig lungs using methylprednisolone

2008 ◽  
Vol 295 (6) ◽  
pp. L998-L1006 ◽  
Author(s):  
Koki Kamiyama ◽  
Naoyuki Matsuda ◽  
Seiji Yamamoto ◽  
Ken-ichi Takano ◽  
Yasuo Takano ◽  
...  
Keyword(s):  
Guinea Pig ◽  
Cell Apoptosis ◽  
Nuclear Translocation ◽  
Lavage Fluid ◽  
Dominant Negative ◽  
Receptor Expression ◽  
Immunofluorescent Staining ◽  
Terminal Deoxynucleotidyl Transferase ◽  
High Dose ◽  
Mobility Shift

The use of glucocorticoids for treatment of sepsis has waxed and waned during the past several decades, and recent randomized controlled trials have evoked a reassessment of this therapy. Most glucocorticoid actions are mediated by its specific intracellular receptors (GRs). Thus we initially evaluated whether sepsis and high-dose corticosteroid therapy can regulate guinea pig pulmonary expression of GRs: active receptor, GRα, and dominant negative receptor, GRβ. Sepsis induction by LPS injection (300 μg/kg ip) decreased mRNA and protein levels of GRα and increased protein expression of GRβ in lungs. High-dose methylprednisolone (40 mg/kg ip), administered simultaneously with LPS, markedly potentiated the decrease in GRα expression but slightly affected the increase in GRβ expression. Consequently, this led to a significant reduction in GRα nuclear translocation. Nevertheless, methylprednisolone treatment strongly eliminated LPS induction of NF-κB activity, as determined by NF-κB nuclear translocation and by gel mobility shift assays. Furthermore, the LPS-induced increase in inflammatory cells in bronchoalveolar lavage fluid was blunted by administration of the corticosteroid. On the other hand, immunofluorescent staining for cleaved caspase-3 showed a marked increase in this proapoptotic marker in lung sections, and terminal deoxynucleotidyl transferase dUTP-mediated nick-end labeling (TUNEL) represented an enhanced appearance of cell apoptosis in lungs and spleen when methylprednisolone was given together with LPS. Cell apoptosis is now considered to play a role in the pathogenesis of septic syndrome. We thus suggest that the action of glucocorticoids at high doses to accelerate sepsis-induced cell apoptosis may overwhelm their therapeutic advantages in septic shock.

scholarly journals Tau accumulation activates STAT1 triggering memory deficits via suppressing NMDA receptor expression

2018 ◽  
Author(s):  
Xiao-Guang Li ◽  
Xiao-Yue Hong ◽  
Ya-li Wang ◽  
Shu-Juan Zhang ◽  
Jun-Fei Zhang ◽  
...  
Keyword(s):  
Nmda Receptor ◽  
Nuclear Translocation ◽  
Memory Performance ◽  
Memory Deficits ◽  
Dominant Negative ◽  
Receptor Expression ◽  
Signal Transducer ◽  
Synaptic Functions ◽  
Direct Binding ◽  
The Brain

ABSTRACTIntracellular tau accumulation forming neurofibrillary tangles is hallmark pathology of Alzheimer's disease (AD), but how tau accumulation induces synapse impairment is elusive. By overexpressing human full-length wildtype tau (termed hTau) to mimic tau abnormality as seen in the brain of sporadic AD patients, we found that hTau accumulation activated JAK2 to phosphorylate STAT1 (Signal Transducer and Activator of Transcription 1) at Tyr701 leading to STAT1 dimerization, nuclear translocation and its activation. STAT1 activation suppressed expression of N-methyl-D-aspartate receptors (NMDARs) through direct binding to the specific GAS element of GluN1, GluN2A and GluN2B promoters, while knockdown STAT1 by AAV-Cre in STAT1flox/flox mice or expressing dominant negative Y701F-STAT1 efficiently rescued hTau-induced suppression of NMDARs expression with amelioration of synaptic functions and memory performance. These findings indicate that hTau accumulation impairs synaptic plasticity through JAK2/STAT1-induced suppression of NMDARs expression, revealing a novel mechanism for hTau-associated synapse and memory deficits.

scholarly journals Pneumocystis Activates Human Alveolar Macrophage NF-κB Signaling through Mannose Receptors

2004 ◽  
Vol 72 (6) ◽  
pp. 3147-3160 ◽  
Author(s):  
Jianmin Zhang ◽  
Jinping Zhu ◽  
Amy Imrich ◽  
Melanie Cushion ◽  
T. Bernard Kinane ◽  
...  
Keyword(s):  
Hiv Infection ◽  
Nuclear Translocation ◽  
Competitive Inhibition ◽  
Mannose Receptor ◽  
Innate Immune ◽  
Receptor Expression ◽  
Dependent Manner ◽  
Mobility Shift ◽  
Human Alveolar Macrophage ◽  
Mannose Receptors

ABSTRACT Alveolar macrophages (AM) represent important effector cells in the innate immune response to the AIDS-related pathogen Pneumocystis, but the early AM host defense signaling events are poorly defined. Using AM from healthy individuals, we showed in the present study that Pneumocystis organisms stimulate AM NF-κB p50 and p65 nuclear translocation in a time-dependent and multiplicity-of-infection-dependent manner as determined by electrophoretic mobility shift assay and immunofluorescence microscopy and that NF-κB nuclear translocation is associated with I-κB phosphorylation. Importantly, competitive inhibition of mannose receptor and targeted short interfering RNA-mediated gene suppression of mannose receptor mRNA and protein is associated with complete elimination of NF-κB nuclear translocation in response to Pneumocystis. Furthermore, human immunodeficiency virus (HIV) infection of AM (as a model human disease state of reduced AM mannose receptor expression and function) inhibits Pneumocystis-mediated NF-κB nuclear translocation and is associated with reduced I-κB phosphorylation and reduced interleukin-8 (IL-8) release. In contrast, NF-κB nuclear translocation and IL-8 release in response to lipopolysaccharide are intact in AM from both healthy and HIV-infected individuals, indicating that the observed impairment is not a global disturbance of the NF-κB pathway. Thus, in addition to phagocytic and endocytic effector functions, the present study identifies mannose receptors as pattern recognition receptors capable of NF-κB activation in response to infectious non-self challenge. AM mannose receptor-mediated NF-κB activation may represent an important mechanism of the host cell response to Pneumocystis, and altered NF-κB activation in the context of HIV infection may impair a critical innate immune signaling response and may contribute to pathogenesis of opportunistic lung infections.

scholarly journals Nicotine Modulates CTSS (Cathepsin S) Synthesis and Secretion Through Regulating the Autophagy-Lysosomal Machinery in Atherosclerosis

2020 ◽  
Vol 40 (9) ◽  
pp. 2054-2069 ◽  
Author(s):  
Huaner Ni ◽  
Shuang Xu ◽  
Hangwei Chen ◽  
Qiuyan Dai
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Nuclear Translocation ◽  
Critical Role ◽  
Mammalian Target Of Rapamycin ◽  
Immunofluorescent Staining ◽  
Luciferase Reporter ◽  
Cathepsin S ◽  
Mobility Shift

Objective: Increased CTSS (cathepsin S) has been reported to play a critical role in atherosclerosis progression. Both CTSS synthesis and secretion are essential for exerting its functions. However, the underlying mechanisms contributing to CTSS synthesis and secretion in atherosclerosis remain unclear. Approach and Results: In this study, we showed that nicotine activated autophagy and upregulated CTSS expression in vascular smooth muscle cells and in atherosclerotic plaques. Western blotting and immunofluorescent staining showed that nicotine inhibited the mTORC1 (mammalian target of rapamycin complex 1) activity, promoted the nuclear translocation of TFEB (transcription factor EB), and upregulated the expression of CTSS. Chromatin immunoprecipitation-qualificative polymerase chain reaction, electrophoretic mobility shift assay, and luciferase reporter assay further demonstrated that TFEB directly bound to the CTSS promoter. mTORC1 inhibition by nicotine or rapamycin promoted lysosomal exocytosis and CTSS secretion. Live cell assays and IP-MS (immunoprecipitation-mass spectrometry) identified that the interactions involving Rab10 (Rab10, member RAS oncogene family) and mTORC1 control CTSS secretion. Nicotine promoted vascular smooth muscle cell migration by upregulating CTSS, and CTSS inhibition suppressed nicotine-induced atherosclerosis in vivo. Conclusions: We concluded that nicotine mediates CTSS synthesis and secretion through regulating the autophagy-lysosomal machinery, which offers a potential therapeutic target for atherosclerosis treatment.

Amifostine Inhibits Hematopoietic Progenitor Cell Apoptosis by Activating NF-κB/Rel Transcription Factors

Blood ◽  
1999 ◽  
Vol 94 (12) ◽  
pp. 4060-4066 ◽  
Author(s):  
Maria Fiammetta Romano ◽  
Annalisa Lamberti ◽  
Rita Bisogni ◽  
Corrado Garbi ◽  
Antonio M. Pagnano ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Cell Apoptosis ◽  
Progenitor Cell ◽  
Cell Types ◽  
Hematopoietic Progenitor Cell ◽  
Hematopoietic Progenitor ◽  
Mobility Shift ◽  
Human Cord Blood ◽  
Mobility Shift Assay ◽  
Induced Apoptosis

Abstract We investigated the involvement of NF-κB/Rel transcription factors that reportedly can inhibit apoptosis in various cell types in the antiapoptotic mechanism of the cytoprotectant amifostine. In the nontumorigenic murine myeloid progenitor 32D cells incubated with amifostine, we detected a reduction of the IκB cytoplasmic levels by Western blotting and a raising of nuclear NF-κB/Rel complexes by electrophoretic mobility shift assay. Amifostine inhibited by more than 30% the growth factor deprivation-induced apoptosis, whereas its effect failed when we blocked the NF-κB/Rel activity with an NF-κB/Rel-binding phosphorothioate decoy oligodeoxynucleotide. In human cord blood CD34+ cells, the NF-κB/Rel p65 subunit was detectable (using immunofluorescence analysis) mainly in the cytoplasm in the absence of amifostine, whereas its presence was appreciable in the nuclei of cells incubated with the cytoprotectant. In 4 CD34+ samples incubated for 3 days in cytokine-deficient conditions, cell apoptosis was reduced by more than 30% in the presence of amifostine (or amifostine plus a control oligo); the effect of amifostine was abolished in cultures with the decoy oligo. These findings indicate that the inhibition of hematopoietic progenitor cell apoptosis by amifostine requires the induction of NF-κB/Rel factors and that the latter can therefore exert an antiapoptotic activity in the hematopoietic progenitor cell compartment. Furthermore, the identification of this specific mechanism underlying the survival-promoting activity of amifostine lends support to the possible use of this agent in apoptosis-related pathologies, such as myelodysplasias.

scholarly journals CHOP Enhancement of Gene Transcription by Interactions with Jun/Fos AP-1 Complex Proteins

1999 ◽  
Vol 19 (11) ◽  
pp. 7589-7599 ◽  
Author(s):  
Mariano Ubeda ◽  
Mario Vallejo ◽  
Joel F. Habener
Keyword(s):  
Transcription Factor ◽  
Gene Transcription ◽  
Stress Responses ◽  
Leucine Zipper ◽  
Target Genes ◽  
Cellular Stress ◽  
Dominant Negative ◽  
Dimerization Domain ◽  
Mobility Shift

ABSTRACT The transcription factor CHOP (C/EBP homologous protein 10) is a bZIP protein induced by a variety of stimuli that evoke cellular stress responses and has been shown to arrest cell growth and to promote programmed cell death. CHOP cannot form homodimers but forms stable heterodimers with the C/EBP family of activating transcription factors. Although initially characterized as a dominant negative inhibitor of C/EBPs in the activation of gene transcription, CHOP-C/EBP can activate certain target genes. Here we show that CHOP interacts with members of the immediate-early response, growth-promoting AP-1 transcription factor family, JunD, c-Jun, and c-Fos, to activate promoter elements in the somatostatin, JunD, and collagenase genes. The leucine zipper dimerization domain is required for interactions with AP-1 proteins and transactivation of transcription. Analyses by electrophoretic mobility shift assays and by an in vivo mammalian two-hybrid system for protein-protein interactions indicate that CHOP interacts with AP-1 proteins inside cells and suggest that it is recruited to the AP-1 complex by a tethering mechanism rather than by direct binding of DNA. Thus, CHOP not only is a negative or a positive regulator of C/EBP target genes but also, when tethered to AP-1 factors, can activate AP-1 target genes. These findings establish the existence of a new mechanism by which CHOP regulates gene expression when cells are exposed to cellular stress.

scholarly journals Activation of Nuclear Factor κb and bcl-x Survival Gene Expression by Nerve Growth Factor Requires Tyrosine Phosphorylation of IκBα

2001 ◽  
Vol 152 (4) ◽  
pp. 753-764 ◽  
Author(s):  
Nguyen Truc Bui ◽  
Antonia Livolsi ◽  
Jean-Francois Peyron ◽  
Jochen H.M. Prehn
Keyword(s):  
Gene Expression ◽  
Tyrosine Phosphorylation ◽  
Fluorescent Protein ◽  
Nuclear Translocation ◽  
Nuclear Factor Κb ◽  
Dominant Negative ◽  
Dominant Negative Mutant ◽  
Nuclear Factor ◽  
Human Neuroblastoma ◽  
Tnf Α

NGF has been shown to support neuron survival by activating the transcription factor nuclear factor-κB (NFκB). We investigated the effect of NGF on the expression of Bcl-xL, an anti–apoptotic Bcl-2 family protein. Treatment of rat pheochromocytoma PC12 cells, human neuroblastoma SH-SY5Y cells, or primary rat hippocampal neurons with NGF (0.1–10 ng/ml) increased the expression of bcl-xL mRNA and protein. Reporter gene analysis revealed a significant increase in NFκB activity after treatment with NGF that was associated with increased nuclear translocation of the active NFκB p65 subunit. NGF-induced NFκB activity and Bcl-xL expression were inhibited in cells overexpressing the NFκB inhibitor, IκBα. Unlike tumor necrosis factor-α (TNF-α), however, NGF-induced NFκB activation occurred without significant degradation of IκBs determined by Western blot analysis and time-lapse imaging of neurons expressing green fluorescent protein–tagged IκBα. Moreover, in contrast to TNF-α, NGF failed to phosphorylate IκBα at serine residue 32, but instead caused significant tyrosine phosphorylation. Overexpression of a Y42F mutant of IκBα potently suppressed NFG-, but not TNF-α–induced NFκB activation. Conversely, overexpression of a dominant negative mutant of TNF receptor-associated factor-6 blocked TNF-α–, but not NGF-induced NFκB activation. We conclude that NGF and TNF-α induce different signaling pathways in neurons to activate NFκB and bcl-x gene expression.

Transcriptional transactivation functions localized to the glucocorticoid receptor N terminus are necessary for steroid induction of lymphocyte apoptosis

1992 ◽  
Vol 12 (2) ◽  
pp. 589-597
Author(s):  
E S Dieken ◽  
R L Miesfeld
Keyword(s):  
Transcriptional Regulation ◽  
Glucocorticoid Receptor ◽  
Target Genes ◽  
Dominant Negative ◽  
Receptor Expression ◽  
Transactivation Domain ◽  
Lymphocyte Apoptosis ◽  
Murine Cell Line ◽  
N Terminus ◽  
Simplex Virus

Genetic studies have suggested that transcriptional regulation of specific target genes (by either induction or repression) is the molecular basis of glucocorticoid-mediated lymphocyte apoptosis. To examine the role of transcriptional regulation more directly, we developed a complementation assay utilizing stable transfection of wild-type (wt) and mutant (nti) glucocorticoid receptor (GR) cDNA constructs into a GR-deficient S49 murine cell line (7r). Our data confirm that the level of functional GR is rate limiting for S49 apoptosis and moreover that the GR amino terminus (N terminus), which as been deleted from the nti GR, is absolutely required for complementation in this system. Surprisingly, we found that at physiological levels of receptor, expression of the nti GR in cells containing wt GR results in enhanced dexamethasone sensitivity rather than a dominant negative phenotype. One interpretation of these data is that DNA binding by wt-nti heterodimers may be functionally similar to that of wt-wt homodimers, indicating that GRE occupancy by at least one transactivation domain may be sufficient to induce the hormonal response. To determine whether acidic activating sequences such as those localized to the GR N terminus are important in the induction of lymphocyte apoptosis, we tested the activity of a chimeric receptor in which we replaced the entire GR N terminus with sequences from the herpes simplex virus VP16 protein. Our results demonstrate that 7r cells expressing VP-GR fusions are indeed steroid sensitive, strongly supporting the idea that S49 apoptosis is dependent on transcriptional regulation of specific genes which respond to acidic activating domains, implying that induction, rather than repression, may be the critical initiating event.

In utero exposure of high-dose di-n-butyl phthalate resulted in opposite effects on testicular cell apoptosis in late embryonic and pubertal male rat offspring

2017 ◽  
Vol 36 (12) ◽  
pp. 1236-1247 ◽  
Author(s):  
H Shen ◽  
K Liao ◽  
H-F Wu ◽  
H-C Lu ◽  
Y Li ◽  
...  
Keyword(s):  
Western Blot ◽  
Cell Apoptosis ◽  
In Utero ◽  
Male Rat ◽  
In Utero Exposure ◽  
High Dose ◽  
Testicular Cell ◽  
Rat Testis ◽  
Rat Offspring ◽  
Butyl Phthalate

Objective: To investigate the effects of in utero exposure to high-dose di- n-butyl phthalate (DBP) on testicular cell apoptosis in late embryonic and pubertal male rat offspring. Methods: Twenty pregnant Sprague-Dawley (SD) rats were divided into two groups. During gestation day (GD) 12 to GD 19, control group was given 1 ml day−1 of olive oil and experimental group was given DBP 500 mg kg−1 day−1 by gavage. On GD 19.5 and postnatal day (PND) 45, the testes were removed. Morphological analysis of the testes was observed by transmission electron microscopy and hematoxylin and eosin (H&E) staining. Testicular cell apoptosis was detected by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL). The expression of Bcl-2, Bax, and p53 was presented by immunohistochemistry (IHC) and western blot. Data of the two groups was compared using independent samples t-test and Mann–Whitney test by SPSS 20.0. Results: H&E staining showed that spermatogenetic cells were significantly decreased in DBP exposed pubertal rat testis. The apoptosis index of testes in DBP-treated group was significantly lower on GD 19.5 but higher on PND 45 than that of the controls ( p < 0.01). IHC and western blot revealed significantly increased expression of Bcl-2 in GD 19.5 rat testis and Bax and p53 in PND 45 rat testis after DBP exposure, compared with the control ( p < 0.05). Conclusion: In utero exposure of high-dose DBP resulted in opposite effects on testicular cell apoptosis in late embryonic and pubertal rat offspring. The overexpression of Bcl-2, Bax, and p53 might be related to the occurrence of abnormal apoptosis and finally produce male infertility.

scholarly journals Nuclear translocation of granzyme B in target cell apoptosis

2000 ◽  
Vol 7 (1) ◽  
pp. 17-24 ◽  
Author(s):  
M J Pinkoski ◽  
J A Heibein ◽  
M Barry ◽  
R C Bleackley
Keyword(s):  
Target Cell ◽  
Cell Apoptosis ◽  
Nuclear Translocation ◽  
Granzyme B

Erythropoietin and erythropoietin receptor expression in the guinea pig inner ear

2005 ◽  
Vol 203 (1-2) ◽  
pp. 21-27 ◽  
Author(s):  
Per Cayé-Thomasen ◽  
Niels Wagner ◽  
Birgitte Lidegaard Frederiksen ◽  
Korhan Asal ◽  
Jens Thomsen
Keyword(s):  
Guinea Pig ◽  
Inner Ear ◽  
Erythropoietin Receptor ◽  
Receptor Expression
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