The Role of MyD88 and TNF-α in the Inflammatory Response in the Middle Ear

2006 ◽  
Vol 117 (2) ◽  
pp. S147
Author(s):  
S.I. Wasserman ◽  
J. Ebmeyer ◽  
K. Pak ◽  
A. Ryan
2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Jianwei Zhang ◽  
Lei Han ◽  
Feng Chen

Abstract Background Let-7a-5p is demonstrated to be a tumor inhibitor in nasopharyngeal carcinoma. However, the role of let-7a-5p in chronic rhinosinusitis with nasal polyps (CRSwNP) has not been reported. This study is designed to determine the pattern of expression and role of let-7a-5p in CRSwNP. Methods The expression level of let-7a-5p, TNF-α, IL-1β, and IL-6 in CRSwNP tissues and cells were detected by RT-qPCR. Western blot assay was carried out to measure the protein expression of the Ras-MAPK pathway. Dual luciferase reporter assay and RNA pull-down assay were used to explore the relationship between let-7a-5p and IL-6. Results Let-7a-5p was significantly downregulated in CRSwNP tissues and cells. Moreover, the mRNA expression of TNF-α, IL-1β and IL-6 was increased in CRSwNP tissues, while let-7a-5p mimic inhibited the expression of TNF-α, IL-1β and IL-6. Besides that, let-7a-5p was negatively correlated with TNF-α, IL-1β and IL-6 in CRSwNP tissues. In our study, IL-6 was found to be a target gene of let-7a-5p. Additionally, let-7-5p mimic obviously reduced the protein levels of Ras, p-Raf1, p-MEK1 and p-ERK1/2, while IL-6 overexpression destroyed the inhibitory effect of let-7a-5p on the Ras-MAPK pathway in CRSwNP. Conclusion We demonstrated that let-7a-5p/IL-6 interaction regulated the inflammatory response through the Ras-MAPK pathway in CRSwNP.


Author(s):  
Meng Li ◽  
Xiaoyang Huang ◽  
Qingcui Zhuo ◽  
Jinghui Zhang ◽  
Xiuli Ju

Neonatal sepsis (NS) occurs in neonates within 28 days, especially preterm infants. The dysregulation of miRNAs is widely detected in NS. The study investigated the expression changes and clinical significance of miR-129-5p in NS patients and further explored the regulatory role of miR-129-5p in the LPS-induced inflammatory response in monocytes. A total of 75 neonates with NS and 84 neonates without NS were recruited. qRT-PCR was used for the measurement of miR-129-5p expression. The receiver operating characteristic (ROC) curve was constructed for diagnostic value analysis. ELISA was used to detect the concentration of inflammatory cytokines. Monocytes were isolated from the blood of neonates to investigate the role of miR-129-5p in the LPS-induced inflammatory response in vitro. miR-129-5p was low expressed in the serum of NS cases compared with controls. Serum miR-129-5p had a diagnostic value for NS with a sensitivity of 82.7% and specificity of 79.8%. There was close association for serum miR-129-5p with TNF-α (r = -0.652, p < 0.001) and IL-8 (r = -0.700, p < 0.001) levels in NS patients. Overexpression of miR-129-5p reversed the increasing trend of TNF-α and IL-8 induced by LPS, whereas miR-129-5p downregulation aggravated the increase of TNF-α and IL-8 induced by LPS in monocytes. MiR-129-5p was downregulated in the serum of NS patients, and it might be a promising biomarker for disease diagnosis. Overexpression of miR-129-5p alleviated the inflammatory response of NS.


2021 ◽  
Author(s):  
Kim Chiok ◽  
Kevin Hutchison ◽  
Lindsay Grace Miller ◽  
Santanu Bose ◽  
Tanya A Miura

Critically ill COVID-19 patients infected with SARS-CoV-2 display signs of generalized hyperinflammation. Macrophages trigger inflammation to eliminate pathogens and repair tissue, but this process can also lead to hyperinflammation and resulting exaggerated disease. The role of macrophages in dysregulated inflammation during SARS-CoV-2 infection is poorly understood. We used SARS-CoV-2 infected and glycosylated soluble SARS-CoV-2 Spike S1 subunit (S1) treated THP-1 human-derived macrophage-like cell line to clarify the role of macrophages in pro-inflammatory responses. Soluble S1 upregulated TNF-α and CXCL10 mRNAs, and induced secretion of TNF-α from THP-1 macrophages. While THP-1 macrophages did not support productive SARS-CoV-2 replication, virus infection resulted in upregulation of both TNF-α and CXCL10 genes. Our study shows that S1 is a key viral component inducing inflammatory response in macrophages, independently of virus replication. Thus, virus-infected or soluble S1-activated macrophages may become sources of pro-inflammatory mediators contributing to hyperinflammation in COVID-19 patients.


2020 ◽  
Vol 40 (6) ◽  
Author(s):  
Xudong Wang ◽  
Yali Wang ◽  
Mingjian Kong ◽  
Jianping Yang

Abstract Background: Septic acute kidney injury is considered as a severe and frequent complication that occurs during sepsis. The present study was performed to understand the role of miR-22-3p and its underlying mechanism in sepsis-induced acute kidney injury. Methods: Rats were injected with adenovirus carrying miR-22-3p or miR-NC in the caudal vein before cecal ligation. Meanwhile, HK-2 cells were transfected with the above adenovirus following LPS stimulation. We measured the markers of renal injury (blood urea nitrogen (BUN), serum creatinine (SCR)). Histological changes in kidney tissues were examined by hematoxylin and eosin (H&E), Masson staining, periodic acid Schiff staining and TUNEL staining. The levels of IL-1β, IL-6, TNF-α and NO were determined by ELISA assay. Using TargetScan prediction and luciferase reporter assay, we predicted and validated the association between PTEN and miR-22-3p. Results: Our data showed that miR-22-3p was significantly down-regulated in a rat model of sepsis-induced acute kidney injury, in vivo and LPS-induced sepsis model in HK-2 cells, in vitro. Overexpression of miR-22-3p remarkably suppressed the inflammatory response and apoptosis via down-regulating HMGB1, p-p65, TLR4 and pro-inflammatory factors (IL-1β, IL-6, TNF-α and NO), both in vivo and in vitro. Moreover, PTEN was identified as a target of miR-22-3p. Furthermore, PTEN knockdown augmented, while overexpression reversed the suppressive role of miR-22-3p in LPS-induced inflammatory response. Conclusions: Our results showed that miR-22-3p induced protective role in sepsis-induced acute kidney injury may rely on the repression of PTEN.


1998 ◽  
Vol 274 (1) ◽  
pp. L26-L31 ◽  
Author(s):  
Paul J. Jagielo ◽  
Timothy J. Quinn ◽  
Nilofer Qureshi ◽  
David A. Schwartz

To further determine the importance of endotoxin in grain dust-induced inflammation of the lower respiratory tract, we evaluated the efficacy of pentaacylated diphosphoryl lipid A derived from the lipopolysaccharide of Rhodobacter sphaeroides (RsDPLA) as a partial agonist of grain dust-induced airway inflammation. RsDPLA is a relatively inactive compound compared with lipid A derived from Escherichia coli (LPS) and has been demonstrated to act as a partial agonist of LPS-induced inflammation. To assess the potential stimulatory effect of RsDPLA in relation to LPS, we incubated THP-1 cells with RsDPLA (0.001–100 μg/ml), LPS (0.02 μg endotoxin activity/ml), or corn dust extract (CDE; 0.02 μg endotoxin activity/ml). Incubation with RsDPLA revealed a tumor necrosis factor (TNF)-α stimulatory effect at 100 μg/ml. In contrast, incubation with LPS or CDE resulted in TNF-α release at 0.02 μg/ml. Pretreatment of THP-1 cells with varying concentrations of RsDPLA before incubation with LPS or CDE (0.02 μg endotoxin activity/ml) resulted in a dose-dependent reduction in the LPS- or CDE-induced release of TNF-α with concentrations of RsDPLA of up to 10 μg/ml but not at 100 μg/ml. To further understand the role of endotoxin in grain dust-induced airway inflammation, we utilized the unique LPS inhibitory property of RsDPLA to determine the inflammatory response to inhaled CDE in mice in the presence of RsDPLA. Ten micrograms of RsDPLA intratracheally did not cause a significant inflammatory response compared with intratracheal saline. However, pretreatment of mice with 10 μg of RsDPLA intratracheally before exposure to CDE (5.4 and 0.2 μg/m3) or LPS (7.2 and 0.28 μg/m3) resulted in significant reductions in the lung lavage concentrations of total cells, neutrophils, and specific proinflammatory cytokines compared with mice pretreated with sterile saline. These results confirm the LPS-inhibitory effect of RsDPLA and support the role of endotoxin as the principal agent in grain dust causing airway inflammation.


Author(s):  
Deiziane V. S. Costa ◽  
Vivaldo Moura-Neto ◽  
David T. Bolick ◽  
Richard L. Guerrant ◽  
Jibraan A. Fawad ◽  
...  

The involvement of the enteric nervous system, which is a source of S100B, in Clostridioides difficile (C. difficile) infection (CDI) is poorly understood although intestinal motility dysfunctions are known to occur following infection. Here, we investigated the role of S100B in CDI and examined the S100B signaling pathways activated in C. difficile toxin A (TcdA)- and B (TcdB)-induced enteric glial cell (EGC) inflammatory response. The expression of S100B was measured in colon tissues and fecal samples of patients with and without CDI, as well as in colon tissues from C. difficile-infected mice. To investigate the role of S100B signaling in IL-6 expression induced by TcdA and TcdB, rat EGCs were used. Increased S100B was found in colonic biopsies from patients with CDI and colon tissues from C. difficile-infected mice. Patients with CDI-promoted diarrhea exhibited higher levels of fecal S100B compared to non-CDI cases. Inhibition of S100B by pentamidine reduced the synthesis of IL-1β, IL-18, IL-6, GMCSF, TNF-α, IL-17, IL-23, and IL-2 and downregulated a variety of NFκB-related genes, increased the transcription (SOCS2 and Bcl-2) of protective mediators, reduced neutrophil recruitment, and ameliorated intestinal damage and diarrhea severity in mice. In EGCs, TcdA and TcdB upregulated S100B-mediated IL-6 expression via activation of RAGE/PI3K/NFκB. Thus, CDI appears to upregulate colonic S100B signaling in EGCs, which in turn augment inflammatory response. Inhibition of S100B activity attenuates the intestinal injury and diarrhea caused by C. difficile toxins. Our findings provide new insight into the role of S100B in CDI pathogenesis and opens novel avenues for therapeutic interventions.


1990 ◽  
Vol 99 (6_suppl) ◽  
pp. 33-34 ◽  
Author(s):  
David J. Lim ◽  
Hideyuki Kawauchi ◽  
Thomas F. DeMaria

2021 ◽  
Author(s):  
Jun Zhou ◽  
Yuhui Que ◽  
Lihua Pan ◽  
Xu Li ◽  
Chao Zhu ◽  
...  

Abstract Supervillin (SVIL), the largest member of villin/gelsolin family, is an actin-binding and membrane-associated protein, that can also be localized to the nucleus. It has been reported that the mRNA expression of SVIL in neutrophils could be increased by lipopolysaccharide (LPS), but the underlying mechanisms remain unknown. Moreover, SVIL was also observed to be involved in the regulation of macrophages’ movement. However, it is not clear whether SVIL is involved in the LPS-induced inflammatory response in macrophages. This work was to investigate the underlying molecular mechanisms of LPS regulating SVIL expression in macrophages and hence the possible role of SVIL in LPS-induced inflammation. Our data showed that in THP-1-derived macrophages, LPS stimulation significantly increased SVIL mRNA and protein expression. Inhibition of TLR4 by Resatorvid (Res) completely reversed the expression of SVIL and inflammatory cytokines (IL-6, IL-1β and TNF-α) induced by LPS. Additionally, ERK1/2 and NF-κB inhibitors (U0126 and BAY) significantly reduced SVIL and IL-6, IL-1β & TNF-α expression. Furthermore, down-regulation of SVIL by SVIL-specific shRNA significantly attenuated the expression of IL-6, IL-1β & TNF-α induced by LPS. Taken together, as a downstream molecule of TLR4/NF-κB and ERK1/2, SVIL was involved in the inflammatory response of LPS-induced elevated IL-6, IL-1β and TNF-α in macrophages.


Sign in / Sign up

Export Citation Format

Share Document