scholarly journals Effects of porcine MyD88 knockdown on the expression of TLR4 pathway-related genes and proinflammatory cytokines

2016 ◽  
Vol 36 (6) ◽  
Author(s):  
Chaohui Dai ◽  
Li Sun ◽  
Lihuai Yu ◽  
Guoqiang Zhu ◽  
Shenglong Wu ◽  
...  
Keyword(s):  
Cell Line ◽  
Proinflammatory Cytokines ◽  
Negative Control ◽  
Signalling Pathway ◽  
Mechanistic Study ◽  
Interferon Α ◽  
Toll Like Receptor ◽  
Pk15 Cell ◽  
Tnf Α ◽  
Factor Α

As a critical adapter protein in Toll-like receptor (TLR)/Interleukin (IL)-1R signalling pathway, myeloid differentiation protein 88 (MyD88) plays an important role in immune responses and host defence against pathogens. The present study was designed to provide a foundation and an important reagent for the mechanistic study of MyD88 and its role TLR/IL-1R signalling pathways in porcine immunity. Lentivirus-mediated RNAi was used to generate a porcine PK15 cell line with a silenced MyD88 gene and quantitative real-time PCR (qPCR) and Western blotting were used to detect changes in the expression of critical genes in the Toll-like receptor 4 (TLR4) signalling pathway. ELISA was used to measure the levels of seven proinflammatory cytokines–interleukin-1β (IL-1β), tumour necrosis factor-α (TNF-α), IL-6, IL-8, IL-12, macrophage inflammatory protein (MIP)-1α and MIP-1β–in cell culture supernatants after MyD88 silencing. We successfully obtained a PK15 cell line with 61% MyD88 mRNA transcript down-regulated. In PK15 cells with MyD88 silencing, the transcript levels of TLR4 and IL-1β were significantly reduced, whereas there were no significant changes in the expression levels of cluster of differentiation antigen 14 (CD14), interferon-α (IFN-α) or TNF-α. The ELISA results showed that the levels of most cytokines were not significantly changed apart from IL-8 without stimulation, which was significantly up-regulated. When cells were induced by lipopolysaccharide (LPS) (0.1 μg/ml) for 6 h, the global level of seven proinflammatory cytokines up-regulated and the level of IL-1β, TNF-α, IL-6, IL-8 and IL-12 of Blank and negative control (NC) group up-regulated more significantly than RNAi group (P<0.05), which revealed that the MyD88 silencing could reduce the TLR4 signal transduction which inhibited the release of proinflammatory cytokines and finally leaded to immunosuppression.

Broad-spectrum sunscreens prevent the secretion of proinflammatory cytokines in human keratinocytes exposed to ultraviolet A and phototoxic lomefloxacin

2006 ◽  
Vol 84 (2) ◽  
pp. 221-226 ◽  
Author(s):  
P. Reinhardt ◽  
M. Cybulski ◽  
S.M. Miller ◽  
C. Ferrarotto ◽  
R. Wilkins ◽  
...  
Keyword(s):  
Cell Viability ◽  
Proinflammatory Cytokines ◽  
Broad Spectrum ◽  
Control Cell ◽  
Human Keratinocytes ◽  
Negative Control ◽  
Cytokine Secretion ◽  
Tnf Α ◽  
Negative Control Cell ◽  
Factor Α

The combination of phototoxic drugs and ultraviolet (UV) radiation can trigger the release of proinflammatory cytokines. The present study measured the ability of sunscreens to prevent cytokine secretion in human keratinocytes following cotreatment of these cells with a known photoreactive drug and UVA. Keratinocytes were treated for 1 h with increasing concentrations of lomefloxacin (LOM) or norfloxacin (NOR), exposed to 15 J/cm2 UVA, and incubated for 24 h. NOR, owing to the absence of a fluorine atom in position 8, was non-phototoxic and used as a negative control. Cell viability and the release of 3 cytokines were assessed, namely interleukin-1α (IL-1α), interleukin-6 (IL-6), and tumour necrosis factor-α (TNF-α). The measurement of these cytokines may be a useful tool for detecting photoreactive compounds. To measure their ability to prevent cytokine secretion, various sunscreens were inserted between the UVA source and the cells. Treatment with NOR, NOR plus UVA, or LOM had no effect on the cells. LOM plus UVA, however, had an effect on cell viability and on cytokine secretion. IL-1α levels increased with LOM concentration. The release of TNF-α and IL-6 followed the same pattern at lower concentrations of LOM but peaked at 15 µmol/L and decreased at higher concentrations. Sunscreens protected the cells from the effects of LOM plus UVA, as cell viability and levels of cytokines remained the same as in the control cells. In conclusion, the application of broad-spectrum sunscreen by individuals exposed to UVA radiation may prevent phototoxic reactions initiated by drugs such as LOM.

scholarly journals Exacerbated Imiquimod-Induced Psoriasis-Like Skin Inflammation in IRF5-Deficient Mice

2020 ◽  
Vol 21 (10) ◽  
pp. 3681
Author(s):  
Momoko Nakao ◽  
Tomomitsu Miyagaki ◽  
Makoto Sugaya ◽  
Shinichi Sato
Keyword(s):  
Critical Role ◽  
Skin Inflammation ◽  
Interferon Α ◽  
Toll Like Receptor ◽  
Adaptive Immune ◽  
Th17 Cytokines ◽  
Factor Α ◽  
Deficient Mice ◽  
Necrosis Factor

Interferon regulatory factors (IRFs) play diverse roles in the regulation of the innate and adaptive immune responses in various diseases. In psoriasis, IRF2 is known to be involved in pathogenesis, while studies on other IRFs are limited. In this study, we investigated the role of IRF5 in psoriasis using imiquimod-induced psoriasis-like dermatitis. Although IRF5 is known to play a critical role in the induction of proinflammatory cytokines by immune cells, such as dendritic cells (DCs), macrophages, and monocytes, IRF5 deficiency unexpectedly exacerbated psoriasiform skin inflammation. The interferon-α and tumor necrosis factor-α mRNA expression levels were decreased, while levels of Th17 cytokines including IL-17, IL-22, and IL-23 were increased in IRF5-deficient mice. Furthermore, IL-23 expression in DCs from IRF5-deficient mice was upregulated both in steady state and after toll-like receptor 7/8 agonist stimulation. Importantly, the expression of IRF4, which is also important for the IL-23 production in DCs, was augmented in DCs from IRF5-deficient mice. Taken together, our results suggest that IRF5 deficiency induces the upregulation of IRF4 in DCs followed by augmented IL-23 production, resulting in the amplification of Th17 responses and the exacerbation of imiquimod-induced psoriasis-like skin inflammation. The regulation of IRF4 or IRF5 expression may be a novel therapeutic approach to psoriasis.

scholarly journals Antibody-Mediated Porcine Reproductive and Respiratory Syndrome Virus Infection Downregulates the Production of Interferon-α and Tumor Necrosis Factor-α in Porcine Alveolar Macrophages via Fc Gamma Receptor I and III

Viruses ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 187
Author(s):  
Liujun Zhang ◽  
Wen Li ◽  
Yangyang Sun ◽  
Linghao Kong ◽  
Pengli Xu ◽  
...  
Keyword(s):  
Virus Infection ◽  
Tumor Necrosis ◽  
Tumor Necrosis Factor Α ◽  
Respiratory Syndrome Virus ◽  
Interferon Α ◽  
Fc Gamma Receptor ◽  
Gamma Receptor ◽  
Tnf Α ◽  
Factor Α ◽  
Necrosis Factor

Antibody-dependent enhancement (ADE) contributes to the pathogenesis of porcine reproductive and respiratory syndrome virus (PRRSV)-persistent infection. However, the mechanisms of PRRSV-ADE infection are still confusing. A clear understanding of the event upon virus infection by the ADE pathway has become crucial for developing efficient intervention of the PRRSV infection. In this study, an ADE assay showed that PRRSV-ADE infection in porcine alveolar macrophages (AMs) significantly decreased the production of interferon-α (IFN-α) and tumor necrosis factor-α (TNF-α), and significantly increased the production of interleukine-10 (IL-10). A gene knockdown assay based on small interfering RNA (siRNA) showed that both Fc gamma receptor I (FcγRI) and FcγRIII in porcine AMs were involved in PRRSV-ADE infection. An activation assay showed that specific activation of FcγRI or FcγRIII in porcine AMs during PRRSV infection not only significantly decreased the production of IFN-α and TNF-α, but also significantly increased the production of IL-10 and significantly facilitated PRRSV replication. In conclusion, our studies suggested that ADE downregulated the production of IFN-α and TNF-α in porcine AMs maybe via FcγRI and FcγRIII, thereby leading to enhanced PRRSV infection.

Cyclosporine Ameliorates Silica-Induced Autoimmune Hepatitis in Rat Model by Altering the Expression of Toll-Like Receptor-4, Interleukin-2 and Tumor Necrosis Factor-α

2022 ◽  
Vol 22 ◽  
Author(s):  
Moustafa M. Mohamed ◽  
Ahmed M. M. Okasha ◽  
Amany H. Abdel Naiem ◽  
Reham F. Mohamed ◽  
Sayed F. Abdelwahab ◽  
...  
Keyword(s):  
Autoimmune Hepatitis ◽  
Interleukin 2 ◽  
Hepatic Function ◽  
Treated Group ◽  
Control Group ◽  
Toll Like Receptor ◽  
Hepatic Diseases ◽  
Tnf Α ◽  
Factor Α ◽  
Necrosis Factor

Background: Autoimmune hepatitis (AIH) is an inflammatory liver disease which is characterized histologically by interface hepatitis, biochemically by elevated transaminase levels, and serologically by the presence of autoantibodies. Toll-like receptor (TLR)-4 is a TLR family member that, upon activation in hepatocytes, initiates a cascade of events. Interleukin-2 (IL-2) and tumour necrosis factor-α (TNF-α) are potent inflammatory cytokines secreted in AIH playing an important role in the early development of inflammation, and hepatocyte damage. Objective: This study examined cyclosporine role in AIH and tried to illustrate its actions on altered hepatic function in silica-induced AIH model. Methods: AIH was induced in Wester rats using Sodium Silicate. The rats were divided into four groups: control group, Silica-AIH group, cyclosporine-treated group, and prevention group. TLR-4, and IL-2 mRNA expression in liver tissues was tested by RT-PCR. Results: AIH was associated with up-regulation of liver enzymes, IL-2, and TLR-4 gene expression while cyclosporine significantly down-regulated the expression of both. The relative quantity of TLR-4 mRNA was 1±0, 13.57±1.91, 4±0.38, and 2±0 in the control, AIH, cyclosporine, and prevention groups, respectively (p<0.001). Also, the relative quantity of IL-2 mRNA was 1±0, 14.79±1.42, 7.07±0.96, and 3.4±0.55 in the same groups, respectively (p<0.001). Additionally, immuno-histochemical staining for TNF-α in liver sections was increased in the silica-AIH group but it was decreased in the cyclosporine-treated and prevention groups. Conclusion: This study advocates a therapeutic role of cyclosporine in treating immune-mediated hepatic diseases. Cyclosporine improves histological alterations in the liver and inhibits the production of proinflammatory cytokines.

The cytokines interleukin-1β and tumor necrosis factor-α stimulate CFTR-mediated fluid secretion by swine airway submucosal glands

2012 ◽  
Vol 303 (4) ◽  
pp. L327-L333 ◽  
Author(s):  
Nicholas Baniak ◽  
Xiaojie Luan ◽  
Amber Grunow ◽  
Terry E. Machen ◽  
Juan P. Ianowski
Keyword(s):  
Tumor Necrosis Factor ◽  
Proinflammatory Cytokines ◽  
Tumor Necrosis ◽  
Tumor Necrosis Factor Α ◽  
Interleukin 1Β ◽  
Tnf Α ◽  
Submucosal Glands ◽  
Factor Α ◽  
Airway Defense ◽  
Necrosis Factor

The airway is kept sterile by an efficient innate defense mechanism. The cornerstone of airway defense is mucus containing diverse antimicrobial factors that kill or inactivate pathogens. Most of the mucus in the upper airways is secreted by airway submucosal glands. In patients with cystic fibrosis (CF), airway defense fails and the lungs are colonized by bacteria, usually Pseudomonas aeruginosa . Accumulating evidence suggests that airway submucosal glands contribute to CF pathogenesis by failing to respond appropriately to inhalation of bacteria. However, the regulation of submucosal glands by the innate immune system remains poorly understood. We studied the response of submucosal glands to the proinflammatory cytokines interleukin-1β and tumor necrosis factor-α. These are released into the airway submucosa in response to infection with the bacterium P. aeruginosa and are elevated in CF airways. Stimulation with IL-1β and TNF-α increased submucosal gland secretion in a concentration-dependent manner with a maximal secretion rate of 240 ± 20 and 190 ± 40 pl/min, respectively. The half maximal effective concentrations were 11 and 20 ng/ml, respectively. The cytokine effect was dependent on cAMP but was independent of cGMP, nitric oxide, Ca2+, or p38 MAP kinase. Most importantly, IL-1β- and TNF-α-stimulated secretion was blocked by the CF transmembrane conductance regulator (CFTR) blocker, CFTRinh172 (100 μmol/l) but was not affected by the Ca2+-activated Cl− channel blocker, niflumic acid (1 μmol/l). The data suggest, that during bacterial infections and resulting release of proinflammatory cytokines, the glands are stimulated to secrete fluid, and this response is mediated by cAMP-activated CFTR, a process that would fail in patients with CF.

Natural limonoids protect mice from alcohol-induced liver injury

2020 ◽  
Vol 31 (5) ◽  
Author(s):  
Abacuc Valansa ◽  
Borris Rosnay Tietcheu Galani ◽  
Pascal Dieudonne Djamen Chuisseu ◽  
Armelle Tontsa Tsamo ◽  
Vincent Brice Ayissi Owona ◽  
...  
Keyword(s):  
Liver Injury ◽  
Positive Control ◽  
Negative Control ◽  
Protective Effects ◽  
Tnf Α ◽  
Factor Α ◽  
Necrosis Factor ◽  
Different Doses ◽  
Better Than

AbstractBackgroundAlcoholic liver disease (ALD) is regarded as a global health problem with limited therapeutic options. Previous studies highlighted some anticancer, antiviral, and hepatoprotective activities of limonoids, but the effects of these compounds on ALD remain unknown. The present study aimed to evaluate the effect of some natural limonoids on ethanol-induced liver injury.MethodsThirty-five albino mice (Mus musculus) were administered with 40% ethanol in the presence or absence of the different limonoids [including three havanensin-type limonoids, TS1, TS3, Rubescin D isolated from an African medicinal plant, Trichilia rubescens Oliv. (Meliaceae), and one limonin], or silymarin at 50 mg/kg for 3 days. Thereafter, the effect of the most active compound was evaluated in a chronic model of ALD. For this purpose, 24 mice with each group consisting of six mice were administered orally with 40% ethanol and limonoid at different doses (50, 75, and 100 mg/kg) for 28 days. Finally, biochemical parameters such as alanine aminotransferase (ALT), superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA), triglyceride (TG), and tumor necrosis factor α (TNF-α) levels were quantified in liver homogenates.ResultsAll tested limonoids significantly (p < 0.01) reduced ALT levels relative to the negative control in the acute model. However, in comparison to other limonoids, limonin at 50 and 75 mg/kg significantly reduced TG, MDA, and TNF-α levels (1.8-fold); alleviated leukocyte infiltration in liver tissue; significantly increased the activity of SOD; and decreased those of CAT better than silymarin used as a positive control at 50 mg/kg.ConclusionsThese data suggest that limonin possesses protective effects on long-term alcohol poisoning partially due to antioxidant and anti-inflammatory mechanisms.

scholarly journals Direct Evidence for Central Proinflammatory Mechanisms in Rats with Experimental Acute Liver Failure: Protective Effect of Hypothermia

2009 ◽  
Vol 29 (5) ◽  
pp. 944-952 ◽  
Author(s):  
Wenlei Jiang ◽  
Paul Desjardins ◽  
Roger F Butterworth
Keyword(s):  
Liver Failure ◽  
Acute Liver Failure ◽  
Brain Edema ◽  
Proinflammatory Cytokines ◽  
Direct Evidence ◽  
Mild Hypothermia ◽  
Tnf Α ◽  
Factor Α ◽  
The Brain ◽  
Necrosis Factor

It has been proposed that proinflammatory mechanisms are involved in the pathogenesis of brain edema in acute liver failure (ALF). The aim of this study was to assess the contribution of cerebral inflammation to the neurologic complications of ALF and to assess the antiinflammatory effect of mild hypothermia. Upregulation of CD11b/c immunoreactivity, consistent with microglial activation, was observed in the brains of ALF rats at coma stages of encephalopathy. Interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) mRNAs were increased two to threefold in the brains of ALF rats compared with that in sham-operated controls. The magnitude of increased expression of proinflammatory cytokines in the brain was correlated with the progression of encephalopathy and the onset of brain edema. Significant increases in IL-1β, IL-6, and TNF-α levels were also found in the sera and cerebrospinal fluid (CSF) of these animals. Mild hypothermia delayed the onset of encephalopathy, prevented brain edema, and concomitantly attenuated plasma, brain, and CSF proinflammatory cytokines. These results show that experimental ALF leads to increases in brain production of proinflammatory cytokines, and afford the first direct evidence that central inflammatory mechanisms play a role in the pathogenesis of the cerebral complications of ALF. Antiinflammatory agents could be beneficial in the management of these complications.

scholarly journals Particle size and activation threshold: a new dimension of danger signaling

Blood ◽  
2010 ◽  
Vol 115 (22) ◽  
pp. 4533-4541 ◽  
Author(s):  
Lorna Rettig ◽  
Sebastian P. Haen ◽  
Anne Greet Bittermann ◽  
Lotta von Boehmer ◽  
Alessandra Curioni ◽  
...  
Keyword(s):  
Immune Cells ◽  
Interferon Α ◽  
Innate Response ◽  
Activation Threshold ◽  
Tnf Α ◽  
Nanometric Particles ◽  
Human Immune ◽  
Factor Α ◽  
Molecular Patterns ◽  
Necrosis Factor

Abstract Previous studies have shown that single-stranded RNA (ssRNA) mixed with protamine forms particles and activates immune cells through Toll-like receptors (TLRs). We have found that the size of protamine-RNA particles generated depends on the electrolyte content when mixing the 2 components. Moreover, we have evidenced that (1) nanometric particles induce production of interferon-α, whereas (2) micrometric particles mainly induce production of tumor necrosis factor-α (TNF-α) in human immune cells. We found that the mechanisms underlying these observations are (1) nanoparticles but not microparticles are selectively phagocytosed by plasmacytoid dendritic cells (pDCs), which produce interferon-α and (2) monocytes that produce TNF-α have a higher activation threshold than that of pDCs. Thus, at the same time as sensing pathogen-associated molecular patterns such as ssRNA, the immune system distinguishes the size of the associated structure in such a way as to trigger the adapted antivirus (nanometric) or antibacterial/antifungal (micrometric) immune response. Our results introduce a new dimension in danger signaling—how size qualitatively affects innate response.

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