scholarly journals Hypoxia Activates SUMO-1-HIF-1α Signaling Pathway to Upregulate Pro-inflammatory Cytokines and Permeability in Human Tonsil Epithelial Cells

2021 ◽  
Author(s):  
Yan Lin ◽  
Mingjing Wang ◽  
Zhen Xiao ◽  
Zhiyan Jiang
Keyword(s):  
Epithelial Cells ◽  
Signaling Pathway ◽  
Behavioral Problems ◽  
Molecular Mechanisms ◽  
Inflammatory Responses ◽  
Hypoxia Inducible Factor ◽  
Hypoxic Condition ◽  
Human Tonsil ◽  
Vitro Model

Abstract Adenoid hypertrophy (AH) can cause harmful effects on untreated children, which include mouth breathing, chronic intermittent hypoxia, sleep disordered breathing (SDB), and even some behavioral problems. However, the molecular mechanisms underlying this pathophysiological process have remained poorly understood. In this study, with use of a variety of biochemical approaches including gene silencing and transiently ectopic protein expression, we examined the molecular effectors involved in this process in an in vitro model of human tonsil epithelial cells (HTECs). We found that a hypoxic condition caused a dramatic upregulation of SUMO-1 expression, a member of the ubiquitin-like protein family, which in turn stabilized hypoxia-inducible factor (HIF)-1α by sumoylating this HIF subunit and thus preventing its ubiquitination and degradation in HTECs. We also found that activating HIF-1α promoted permeability of HTEC cells as well as production and secretion of a variety of proinflammatory cytokines including IL-6, IL-8, and TNF-α, and pro-angiogenic growth factor VEGF. Furthermore, our data showed that hypoxia-induced inflammation was markedly inhibited by M2 macrophages that possess potent anti-inflammatory function. Our results suggest that selectively inhibiting the SUMO-1-HIF-1α signaling pathway leads to inflammatory responses in human tonsil epithelial cells, which might be a novel therapeutic approach for managing hypoxia-induced SDB resulting from AH.

scholarly journals Constitutive Expression of Functionally Active Protease-Activated Receptors 1 and 2 in Human Conjunctival Epithelial Cells

2006 ◽  
Vol 2006 ◽  
pp. 1-8 ◽  
Author(s):  
Timothy J. Nickel ◽  
Mohammad H. Kabir ◽  
Jaya Talreja ◽  
Daniel J. Stechschulte ◽  
Kottarappat N. Dileepan
Keyword(s):  
Epithelial Cells ◽  
Serine Proteases ◽  
Neutralizing Antibodies ◽  
Enzyme Inhibitors ◽  
Inflammatory Responses ◽  
Constitutive Expression ◽  
Protease Activated Receptors ◽  
Vitro Model ◽  
Conjunctival Epithelial Cells

Protease-activated receptors (PARs) are G-protein-coupled receptors which initiate inflammatory responses when activated by specific serine proteases. This study was conducted to examine whether human conjunctival epithelial cells (HCECs) express functionally active PAR1 and PAR2 using Chang conjunctival epithelial cells as in vitro model. We performed RT-PCR and immunofluorescence analyses to determine the expression of PAR1 and PAR2, and monitored the production of IL-6 after activating HCECs with PAR1 activating agents (thrombin or TFLLRN) or PAR2 activating agents (tryptase, trypsin, or SLIGKV). The results show that HCECs constitutively express PAR1 and PAR2 mRNA and proteins, and produce significant amounts of IL-6 when incubated with specific PAR-activating enzymes or agonist peptides. Thrombin- and tryptase-induced HCEC activation was blocked by PAR1 and PAR2 neutralizing antibodies, respectively, and by specific enzyme inhibitors. The constitutive expression of PAR1 and PAR2, and their activation by thrombin and tryptase, respectively, may have important implications in ocular inflammation.

scholarly journals The Impact of Acute or Chronic Alcohol Intake on the NF-κB Signaling Pathway in Alcohol-Related Liver Disease

2020 ◽  
Vol 21 (24) ◽  
pp. 9407
Author(s):  
Aleksander J. Nowak ◽  
Borna Relja
Keyword(s):  
Liver Disease ◽  
Signaling Pathway ◽  
Molecular Mechanisms ◽  
Inflammatory Responses ◽  
Current Knowledge ◽  
In Vivo Studies ◽  
Related Liver Disease ◽  
The Impact

Ethanol misuse is frequently associated with a multitude of profound medical conditions, contributing to health-, individual- and social-related damage. A particularly dangerous threat from this classification is coined as alcoholic liver disease (ALD), a liver condition caused by prolonged alcohol overconsumption, involving several pathological stages induced by alcohol metabolic byproducts and sustained cellular intoxication. Molecular, pathological mechanisms of ALD principally root in the innate immunity system and are especially associated with enhanced functionality of the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathway. NF-κB is an interesting and convoluted DNA transcription regulator, promoting both anti-inflammatory and pro-inflammatory gene expression. Thus, the abundancy of studies in recent years underlines the importance of NF-κB in inflammatory responses and the mechanistic stimulation of inner molecular motifs within the factor components. Hereby, in the following review, we would like to put emphasis on the correlation between the NF-κB inflammation signaling pathway and ALD progression. We will provide the reader with the current knowledge regarding the chronic and acute alcohol consumption patterns, the molecular mechanisms of ALD development, the involvement of the NF-κB pathway and its enzymatic regulators. Therefore, we review various experimental in vitro and in vivo studies regarding the research on ALD, including the recent active compound treatments and the genetic modification approach. Furthermore, our investigation covers a few human studies.

Nano-Curcumin Regulates p53 Phosphorylation and PAI-1 Expression during Bleomycin Induced Injury in Alveolar Basal Epithelial Cells

2020 ◽  
Vol 16 (1) ◽  
pp. 85-89
Author(s):  
Mahesh M. Gouda ◽  
Ashwini Prabhu ◽  
Varsha Reddy S.V. ◽  
Rafa Jahan ◽  
Yashodhar P. Bhandary
Keyword(s):  
Epithelial Cells ◽  
Lung Injury ◽  
Molecular Mechanisms ◽  
A549 Cells ◽  
Plasminogen Activator Inhibitor ◽  
Underlying Mechanism ◽  
Protective Role ◽  
Alveolar Epithelial Cells ◽  
Cellular Damage

Background: Bleomycin (BLM) is known to cause DNA damage in the Alveolar Epithelial Cells (AECs). It is reported that BLM is involved in the up-regulation of inflammatory molecules such as neutrophils, macrophages, chemokines and cytokines. The complex underlying mechanism for inflammation mediated progression of lung injury is still unclear. This investigation was designed to understand the molecular mechanisms associated with p53 mediated modulation of Plasminogen Activator Inhibitor-I (PAI-I) expression and its regulation by nano-curcumin formulation. Methods: A549 cells were treated with BLM to cause the cellular damage in vitro and commercially available nano-curcumin formulation was used as an intervention. Cytotoxic effect of nano-curcumin was analyzed using Methyl Thiazolyl Tetrazolium (MTT) assay. Protein expressions were analyzed using western blot to evaluate the p53 mediated changes in PAI-I expression. Results: Nano-curcumin showed cytotoxicity up to 88.5 % at a concentration of 20 μg/ml after 48 h of treatment. BLM exposure to the cells activated the phosphorylation of p53, which in turn increased PAII expression. Nano-curcumin treatment showed a protective role against phosphorylation of p53 and PAI-I expression, which in turn regulated the fibro-proliferative phase of injury induced by bleomycin. Conclusion: Nano-curcumin could be used as an effective intervention to regulate the severity of lung injury, apoptosis of AECs and fibro-proliferation during pulmonary injury.

scholarly journals MicroRNA-1297 suppressed the Akt/GSK3β signaling pathway and stimulated neural apoptosis in an in vivo sevoflurane exposure model

2021 ◽  
Vol 49 (4) ◽  
pp. 030006052098210
Author(s):  
Quan Wang ◽  
Jingcong Luo ◽  
Ruiqiang Sun ◽  
Jia Liu
Keyword(s):  
Protein Expression ◽  
Signaling Pathway ◽  
Neuronal Apoptosis ◽  
In Vitro Model ◽  
Nervous System Development ◽  
Exposure Model ◽  
Control Group ◽  
Pten Protein ◽  
Vitro Model

Objective Common inhalation anesthetics used for clinical anesthesia (such as sevoflurane) may induce nerve cell apoptosis during central nervous system development. Furthermore, anesthetics can produce cognitive impairments, such as learning and memory impairments, that continue into adulthood. However, the precise mechanism remains largely undefined. We aimed to determine the function of microRNA-1297 (miR-1297) in sevoflurane-induced neurotoxicity. Methods Reverse transcription-polymerase chain reaction assays were used to analyze miR-1297 expression in sevoflurane-exposed mice. MTT and lactate dehydrogenase (LDH) assays were used to measure cell growth, and neuronal apoptosis was analyzed using flow cytometry. Western blot analyses were used to measure PTEN, PI3K, Akt, and GSK3β protein expression. Results In sevoflurane-exposed mice, miR-1297 expression was up-regulated compared with the control group. MiR-1297 up-regulation led to neuronal apoptosis, inhibition of cell proliferation, and increased LDH activity in the in vitro model of sevoflurane exposure. MiR-1297 up-regulation also suppressed the Akt/GSK3β signaling pathway and induced PTEN protein expression in the in vitro model. PTEN inhibition (VO-Ohpic trihydrate) reduced PTEN protein expression and decreased the effects of miR-1297 down-regulation on neuronal apoptosis in the in vitro model. Conclusion Collectively, the results indicated that miR-1297 stimulates sevoflurane-induced neurotoxicity via the Akt/GSK3β signaling pathway by regulating PTEN expression.

Exogenous phospholipase A2 affects inflammatory gene expression in primary bovine mammary epithelial cells

2019 ◽  
Vol 86 (2) ◽  
pp. 177-180
Author(s):  
Jacqueline P. Kurz ◽  
Mark P. Richards ◽  
Matthew Garcia ◽  
Zhongde Wang
Keyword(s):  
Epithelial Cells ◽  
Phospholipase A2 ◽  
Inflammatory Responses ◽  
Mammary Epithelial Cells ◽  
Constitutive Expression ◽  
Mammary Epithelial ◽  
Inflammatory Factors ◽  
Bovine Mammary Epithelial Cells ◽  
Lps Challenge

AbstractThis Research Communication addresses the hypothesis that exogenously administered phospholipase A2 (PLA2) affects the inflammatory responses of bovine mammary epithelial cells (bMEC) in vitro with the aim of providing preliminary justification of investigation into the uses of exogenously administered PLA2 to manage or treat bovine mastitis. Primary bMEC lines from 11 lactating Holstein dairy cows were established and the expression of 14 pro-inflammatory genes compared under unchallenged and lipopolysaccharide (LPS)-challenged conditions, with and without concurrent treatment with bovine pancreatic PLA2G1B, a secreted form of PLA2. No differences in the expression of these genes were noted between PLA2-treated and untreated bMEC under unchallenged conditions. Following LPS challenge, untreated bMEC exhibited significant downregulation of CXCL8, IL1B, CCL20, and CXCL1. In contrast, PLA2-treated bMEC exhibited significant downregulation of IL1B and CCL20 only. These findings indicate that exogenous PLA2 affects the expression of some pro-inflammatory factors in immune-stimulated bMEC, but does not influence the constitutive expression of these factors. Further investigation of the influence of exogenous PLA2 in the bovine mammary gland is justified.

scholarly journals Crocetin Mitigates Irradiation Injury in an In Vitro Model of the Pubertal Testis: Focus on Biological Effects and Molecular Mechanisms

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1676
Author(s):  
Giulia Rossi ◽  
Martina Placidi ◽  
Chiara Castellini ◽  
Francesco Rea ◽  
Settimio D'Andrea ◽  
...  
Keyword(s):  
In Vitro Model ◽  
Molecular Mechanisms ◽  
Biological Effects ◽  
Cellular Damage ◽  
X Rays ◽  
Adolescent Cancer ◽  
Radiation Induced ◽  
Vitro Model ◽  
Underlying Mechanisms

Infertility is a potential side effect of radiotherapy and significantly affects the quality of life for adolescent cancer survivors. Very few studies have addressed in pubertal models the mechanistic events that could be targeted to provide protection from gonadotoxicity and data on potential radioprotective treatments in this peculiar period of life are elusive. In this study, we utilized an in vitro model of the mouse pubertal testis to investigate the efficacy of crocetin to counteract ionizing radiation (IR)-induced injury and potential underlying mechanisms. Present experiments provide evidence that exposure of testis fragments from pubertal mice to 2 Gy X-rays induced extensive structural and cellular damage associated with overexpression of PARP1, PCNA, SOD2 and HuR and decreased levels of SIRT1 and catalase. A twenty-four hr exposure to 50 μM crocetin pre- and post-IR significantly reduced testis injury and modulated the response to DNA damage and oxidative stress. Nevertheless, crocetin treatment did not counteract the radiation-induced changes in the expression of SIRT1, p62 and LC3II. These results increase the knowledge of mechanisms underlying radiation damage in pubertal testis and establish the use of crocetin as a fertoprotective agent against IR deleterious effects in pubertal period.

scholarly journals Role of the C5a-C5a receptor axis in the inflammatory responses of the lungs after experimental polytrauma and hemorrhagic shock

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shinjini Chakraborty ◽  
Veronika Eva Winkelmann ◽  
Sonja Braumüller ◽  
Annette Palmer ◽  
Anke Schultze ◽  
...  
Keyword(s):  
Hemorrhagic Shock ◽  
Inflammatory Responses ◽  
Experimental Models ◽  
Lung Damage ◽  
C5a Receptor ◽  
Cytokine Levels ◽  
Vitro Model

AbstractSingular blockade of C5a in experimental models of sepsis is known to confer protection by rescuing lethality and decreasing pro-inflammatory responses. However, the role of inhibiting C5a has not been evaluated in the context of sterile systemic inflammatory responses, like polytrauma and hemorrhagic shock (PT + HS). In our presented study, a novel and highly specific C5a L-aptamer, NoxD21, was used to block C5a activity in an experimental murine model of PT + HS. The aim of the study was to assess early modulation of inflammatory responses and lung damage 4 h after PT + HS induction. NoxD21-treated PT + HS mice displayed greater polymorphonuclear cell recruitment in the lung, increased pro-inflammatory cytokine levels in the bronchoalveolar lavage fluids (BALF) and reduced myeloperoxidase levels within the lung tissue. An in vitro model of the alveolar-capillary barrier was established to confirm these in vivo observations. Treatment with a polytrauma cocktail induced barrier damage only after 16 h, and NoxD21 treatment in vitro did not rescue this effect. Furthermore, to test the exact role of both the cognate receptors of C5a (C5aR1 and C5aR2), experimental PT + HS was induced in C5aR1 knockout (C5aR1 KO) and C5aR2 KO mice. Following 4 h of PT + HS, C5aR2 KO mice had significantly reduced IL-6 and IL-17 levels in the BALF without significant lung damage, and both, C5aR1 KO and C5aR2 KO PT + HS animals displayed reduced MPO levels within the lungs. In conclusion, the C5aR2 could be a putative driver of early local inflammatory responses in the lung after PT + HS.

scholarly journals Enhancing the Nrf2 Antioxidant Signaling Provides Protection Against Trichloroethene-mediated Inflammation and Autoimmune Response

2020 ◽  
Vol 175 (1) ◽  
pp. 64-74 ◽  
Author(s):  
Nivedita Banerjee ◽  
Hui Wang ◽  
Gangduo Wang ◽  
M Firoze Khan
Keyword(s):  
Oxidative Stress ◽  
T Cells ◽  
Molecular Mechanisms ◽  
Inflammatory Responses ◽  
Autoimmune Response ◽  
Mediated Effects ◽  
Antioxidant Gene Expression ◽  
Responsive Element

Abstract Trichloroethene (trichloroethylene, TCE) and one of its reactive metabolites dichloroacetyl chloride (DCAC) are associated with the induction of autoimmunity in MRL+/+ mice. Although oxidative stress plays a major role in TCE-/DCAC-mediated autoimmunity, the underlying molecular mechanisms still need to be delineated. Nuclear factor (erythroid-derived 2)-like2 (Nrf2) is an oxidative stress-responsive transcription factor that binds to antioxidant responsive element (ARE) and provides protection by regulating cytoprotective and antioxidant gene expression. However, the potential of Nrf2 in the regulation of TCE-/DCAC-mediated autoimmunity is not known. This study thus focused on establishing the role of Nrf2 and consequent inflammatory responses in TCE-/DCAC-mediated autoimmunity. To achieve this, we pretreated Kupffer cells (KCs) or T cells with/without tert-butylhydroquinone (tBHQ) followed by treatment with DCAC. In both KCs and T cells, DCAC treatment significantly downregulated Nrf2 and HO-1 expression along with induction of Keap-1 and caspase-3, NF-κB (p65), TNF-α, and iNOS, whereas pretreatment of these cells with tBHQ attenuated these responses. The in vitro findings were further verified in vivo by treating female MRL+/+ mice with TCE along with/without sulforaphane. TCE exposure in mice also led to reduction in Nrf2 and HO-1 but increased phospho-NF-κB (p-p65) and iNOS along with increased anti-dsDNA antibodies. Interestingly, sulforaphane treatment led to amelioration of TCE-mediated effects, resulting in Nrf2 activation and reduction in inflammatory and autoimmune responses. Our results show that TCE/DCAC mediates an impairment in Nrf2 regulation. Attenuation of TCE-mediated autoimmunity via activation of Nrf2 supports that antioxidants sulforaphane/tBHQ could be potential therapeutic agents for autoimmune diseases.

scholarly journals A Salmonella Virulence Factor Activates the NOD1/NOD2 Signaling Pathway

mBio ◽  
2011 ◽  
Vol 2 (6) ◽  
Author(s):  
A. Marijke Keestra ◽  
Maria G. Winter ◽  
Daisy Klein-Douwel ◽  
Mariana N. Xavier ◽  
Sebastian E. Winter ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Type Iii Secretion ◽  
Salmonella Enterica ◽  
Intestinal Inflammation ◽  
Inflammatory Responses ◽  
Type Iii Secretion System ◽  
Secretion System ◽  
Content Type ◽  
Type Iii

ABSTRACTThe invasion-associated type III secretion system (T3SS-1) ofSalmonella entericaserotype Typhimurium (S. Typhimurium) activates the transcription factor NF-κB in tissue culture cells and induces inflammatory responses in animal models through unknown mechanisms. Here we show that bacterial delivery or ectopic expression of SipA, a T3SS-1-translocated protein, led to the activation of the NOD1/NOD2 signaling pathway and consequent RIP2-mediated induction of NF-κB-dependent inflammatory responses. SipA-mediated activation of NOD1/NOD2 signaling was independent of bacterial invasionin vitrobut required an intact T3SS-1. In the mouse colitis model, SipA triggered mucosal inflammation in wild-type mice but not in NOD1/NOD2-deficient mice. These findings implicate SipA-driven activation of the NOD1/NOD2 signaling pathway as a mechanism by which the T3SS-1 induces inflammatory responsesin vitroandin vivo.IMPORTANCESalmonella entericaserotype Typhimurium (S. Typhimurium) deploys a type III secretion system (T3SS-1) to induce intestinal inflammation and benefits from the ensuing host response, which enhances growth of the pathogen in the intestinal lumen. However, the mechanisms by which the T3SS-1 triggers inflammatory responses have not been resolved. Here we show that the T3SS-1 effector protein SipA induces NF-κB activation and intestinal inflammation by activating the NOD1/NOD2 signaling pathway. These data suggest that the T3SS-1 escalates innate responses through a SipA-mediated activation of pattern recognition receptors in the host cell cytosol.

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