scholarly journals Expression and Secretion of Cathelicidin LL-37 in Human Epithelial Cells after Infection by Mycobacterium bovis Bacillus Calmette-Guérin

2008 ◽  
Vol 15 (9) ◽  
pp. 1450-1455 ◽  
Author(s):  
Patricia Méndez-Samperio ◽  
Elena Miranda ◽  
Artemisa Trejo

ABSTRACT The antimicrobial cathelicidin LL-37 is considered to play an important role in the innate immune response to tuberculosis infection. However, little is known about the induction and secretion of this antimicrobial peptide in A549 epithelial cells after infection with Mycobacterium bovis bacillus Calmette-Guérin (BCG), the world's most widely used tuberculosis vaccine. In this study, we investigated the effect of M. bovis BCG on LL-37 mRNA levels in A549 cells by real-time PCR and on protein levels by Western blotting. Treatment of cells with M. bovis BCG upregulates LL-37 mRNA expression in a dose- and time-dependent manner. The quantitative analysis of LL-37 gene expression correlated with our Western blotting results. Moreover, our results demonstrated that treatment of cells with the transcriptional inhibitor actinomycin D effectively inhibited in a concentration-dependent manner the ability of M. bovis BCG to induce LL-37 mRNA expression. Finally, inhibition of the MEK1/2 and p38 mitogen-activated protein kinase (MAPK) signaling pathways reduced M. bovis BCG-mediated LL-37 mRNA expression, a reduction that correlated with the observed high level of downregulation of LL-37 protein induction. Thus, these results indicate that the MEK1/2 and p38 MAPK signaling pathways play a critical role in the regulation of inducible LL-37 gene expression in A549 cells infected with M. bovis BCG.

2019 ◽  
Vol 86 (2) ◽  
pp. 171-176 ◽  
Author(s):  
Chenxu Zhao ◽  
Yazhou Wang ◽  
Xue Yuan ◽  
Guoquan Sun ◽  
Bingyu Shen ◽  
...  

AbstractSubacute ruminal acidosis (SARA) can increase the level of inflammation and induce rumenitis in dairy cows. Berberine (BBR) is the major active component of Rhizoma Coptidis, which is a type of Chinese anti-inflammatory drug for gastrointestinal diseases. The purpose of this study was to investigate the anti-inflammatory effects of BBR on lipopolysaccharide (LPS)-stimulated rumen epithelial cells (REC) and the underlying molecular mechanisms. REC were cultured and stimulated with LPS in the presence or absence of different concentrations of BBR. The results showed that cell viability was not affected by BBR. Moreover, BBR markedly decreased the concentrations and mRNA expression of pro-inflammatory cytokines, including tumor necrosis factor-α, interleukin-1β, and interleukin-6 in the LPS-treated REC in a dose-dependent manner. Importantly, Western blotting analysis showed that BBR significantly suppressed the protein expression of toll-like receptor 4 (TLR4) and myeloid differentiation primary response protein (MyD88) and the phosphorylation of nuclear factor-κB (NF-κB), inhibitory kappa B (IκBα), p38 mitogen-activated protein kinase (MAPK), and c-Jun N-terminal kinase (JNK) in LPS-treated REC. Furthermore, the results of immunocytofluorescence showed that BBR significantly inhibited the nuclear translocation of NF-κB p65 induced by LPS treatment. In conclusion, the protective effects of BBR on LPS-induced inflammatory responses in REC may be due to its ability to suppress the TLR4-mediated NF-κB and MAPK signaling pathways. These findings suggest that BBR can be used as an anti-inflammatory drug to treat inflammation induced by SARA.


2016 ◽  
Vol 38 (6) ◽  
pp. 2375-2388 ◽  
Author(s):  
Hongyang Hu ◽  
Min Chen ◽  
Guangzu Dai ◽  
Guoqing Du ◽  
Xuezong Wang ◽  
...  

Background/Aims: Bone marrow-derived mesenchymal stem cells (MSCs) are responsible for new bone formation during adulthood. Accumulating evidences showed that Osthole promotes the osteogenic differentiation in primary osteoblasts. The aim of this study was to investigate whether Osthole exhibits a potential to stimulate the osteogenic differentiation of MSCs and the underlying mechanism. Methods: MSCs were treated with a gradient concentration of Osthole (6.25 µM, 12.5 µM, and 25 µM). Cell proliferation was assessed by western blotting with the proliferating cell nuclear antigen (PCNA) and Cyclin D1 antibodies, fluorescence activated cell sorting (FACS), and cell counting kit 8 (CCK8). MSCs were cultured in osteogenesis-induced medium for one or two weeks. The osteogenic differentiation of MSCs was estimated by Alkaline Phosphatase (ALP) staining, Alizarin red staining, Calcium influx, and quantitative PCR (qPCR). The underlying mechanism of Osthole-induced osteogenesis was further evaluated by western blotting with antibodies in Wnt/β-catenin, PI3K/Akt, BMPs/smad1/5/8, and MAPK signaling pathways. Results: Osthole inhibited proliferation of rat MSCs in a dose-dependent manner. Osthole suppressed osteogenic differentiation of rat MSCs by down-regulating the activities of Wnt/β-catenin and Erk1/2-MAPK signaling. Conclusions: Osthole inhibits the proliferation and osteogenic differentiation of rat MSCs, which might be mediated through blocking the Wnt/β-catenin and Erk1/2-MAPK signaling pathways.


2021 ◽  
Author(s):  
Samaneh Abbasi ◽  
Reza Bazyar ◽  
Mohammad Ali Saremi ◽  
Gholamhoseen Alishiri ◽  
Nasrin Seyyedsani ◽  
...  

Abstract Background and aim: Gastric cancer) GC) is one of the most common cancer with high mortality worldwide. The human Wharton's jelly stem cells (hWJSCs) can inhibit several cancer cells through several molecular pathways. Therefore, the present study aimed to investigate anticancer effects of hWJSCs conditioned medium (hWJSC-CM) and cell-free lysate (hWJSC-CL) against of GC cell line AGS and underlying signaling pathways. Methods: In this study, we evaluated the effects of hWJSC-CM and hWJSC-CL on viability, proliferation, migration, invasion, apoptosis, and MAPK and NF‑κB signaling pathways in AGS cells. Moreover, mRNA expression of genes involved in apoptosis (BAX, BCL2, SMAC, and SURVIVIN), as well as expression of proteins involved in NF-κB and MAPK signaling pathways were evaluated. Results: The obtained results showed that the hWJSC-CM and hWJSC-CL decreased viability, migration, and invasion of GC cell line AGS in a concentration and time dependent manner. We observed that the hWJSC-CM and hWJSC-CL induced apoptosis pathway through regulation of apoptosis involved genes mRNA expression. In addition, the hWJSC-CM and hWJSC-CL suppressed NF-κB signaling pathways as well as promoted MAPK signaling pathways. Conclusions: In general, our study suggested that the hWJSC-CM and hWJSC-CL inhibits proliferation and viability of GC cell line AGS through induction of apoptosis, as well as modification of NF-κB and MAPK signaling pathways.


Biology ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1356
Author(s):  
Ling Ge ◽  
Shuangxia Zou ◽  
Zehu Yuan ◽  
Weihao Chen ◽  
Shanhe Wang ◽  
...  

Escherichia coli (E. coli) F17 is a member of enterotoxigenic Escherichia coli, which can cause massive diarrhea and high mortality in newborn lambs. β-defensin is mainly produced by the epithelial tissue of the gastrointestinal tract in response to microbial infection. However, the molecular mechanism of sheep β-defensin 2 (SBD-2) against E. coli F17 remains unclear. This study aims to reveal the antibacterial ability of SBD-2 against E. coli F17 infection in sheep. Firstly, we established the culture system of ovine intestinal epithelial cells (OIECs) in vitro, treated with different concentrations of E. coli F17 for an indicated time. Secondly, we performed RNA interference and overexpression to investigate the effect of SBD-2 expression on E. coli F17 adhesion to OIECs. Finally, inhibitors of NF-κB and MAPK pathways were pre-treated to explore the possible relationship involving in E. coli F17 infection regulating SBD-2 expression. The results showed that E. coli F17 markedly (p < 0.01) upregulated the expression levels of SBD-2 mRNA and protein in a concentration- and time-dependent manner. Overexpression of SBD-2 contributed to enhancing E. coli F17 resistance in OIECs, while silencing SBD-2 dramatically improved the adhesion of E. coli F17 to OIECs (p < 0.05 or p < 0.01). Furthermore, E. coli F17 stimulated SBD-2 expression was obviously decreased by pre-treatment with NF-κB inhibitor PDTC, p38 MAPK inhibitor SB202190 and ERK1/2 MAPK inhibitor PD98095 (p < 0.05 or p < 0.01). Interestingly, adhesion of E. coli F17 to OIECs were highly enhanced by pre-treated with PDTC, SB202190 and PD98095. Our data suggested that SBD-2 could inhibit E. coli F17 infection in OIECs, possibly through NF-κB and MAPK signaling pathways. Our results provide useful theoretical basis on developing anti-infective drug and breeding for E. coli diarrhea disease-resistant sheep.


Toxins ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 301
Author(s):  
Yu-Hsiang Yu ◽  
Yi-Han Lai ◽  
Felix Shih-Hsiang Hsiao ◽  
Yeong-Hsiang Cheng

Deoxynivalenol (DON) is the most prevalent mycotoxin in swine feedstuffs. The intestinal epithelial cells represent the first target for the DON. Here, we studied the effects of DON and mycotoxin adsorbent agents on mitogen-activated protein kinase (MAPK) signaling pathways and inflammation-associated gene expression in porcine intestinal epithelial cells (IPEC-J2). Results showed that phosphorylation of MAPK signaling pathways (p38, ERK, and JNK) was increased after treatment of DON or lipopolysaccharide (LPS) in IPEC-J2 cells. The phosphorylation of p38, ERK, and JNK was not further enhanced after co-treatment with DON and LPS. The inos and cox-2 mRNA expression were significantly induced at 6 h after treatment of DON. DON treatment significantly increased the claudin 3 and occludin mRNA expression at 12 h. DON in combination with LPS treatment did not further increase the inflammation and tight junction-associated gene expression. The DON-induced phosphorylation of MAPK signaling pathways was impaired by mycotoxin adsorbent agent (nanoscale silicate platelets and the mixture of montmorillonites and yeast cell walls) treatment, thereby decreasing inflammation and tight junction-associated gene expression. Taken together, these findings demonstrate that DON triggers the inflammation in IPEC-J2 cells by phosphorylation of MAPK signaling pathways and LPS does not further augment the DON-induced inflammatory responses. Mycotoxin adsorbent agents can attenuate DON-induced inflammatory responses in IPEC-J2 cells through modulation of the phosphorylation of p38, ERK, and JNK.


2008 ◽  
Vol 295 (3) ◽  
pp. H1319-H1329 ◽  
Author(s):  
Konstantina Stathopoulou ◽  
Isidoros Beis ◽  
Catherine Gaitanaki

pH is one of the most important physiological parameters, with its changes affecting the function of vital organs like the heart. However, the effects of alkalosis on the regulation of cardiac myocyte function have not been extensively investigated. Therefore, we decided to study whether the mitogen-activated protein kinase (MAPK) signaling pathways [c-Jun NH2-terminal kinases (JNKs), extracellular signal-regulated kinases (ERKs), and p38 MAPK] are activated by alkalosis induced with Tris-Tyrode buffer at two pH values, 8.5 and 9.5, in H9c2 rat cardiac myoblasts. These buffers also induced intracellular alkalinization comparable to that induced by 1 mM NH4Cl. The three MAPKs examined presented differential phosphorylation patterns that depended on the severity and the duration of the stimulus. Inhibition of Na+/H+ exchanger (NHE)1 by its inhibitor HOE-642 prevented alkalinization and partially attenuated the alkalosis (pH 8.5)-induced activation of these kinases. The same stimulus also promoted c-Jun phosphorylation and enhanced the binding at oligonucleotides bearing the activator protein-1 (AP-1) consensus sequence, all in a JNK-dependent manner. Additionally, mitogen- and stress-activated kinase 1 (MSK1) was transiently phosphorylated by alkalosis (pH 8.5), and this was abolished by the selective inhibitors of either p38 MAPK or ERK pathways. JNKs also mediated Bcl-2 phosphorylation in response to incubation with the alkaline medium (pH 8.5), while selective inhibitors of the three MAPKs diminished cell viability under these conditions. All these data suggest that alkalosis activates MAPKs in H9c2 cells and these kinases, in turn, modify proteins that regulate gene transcription and cell survival.


2011 ◽  
Vol 300 (1) ◽  
pp. L81-L87 ◽  
Author(s):  
Sharmistha Bhattacharyya ◽  
Usha Gutti ◽  
Jose Mercado ◽  
Chad Moore ◽  
Harvey B. Pollard ◽  
...  

Cystic fibrosis (CF) is characterized by a massive proinflammatory phenotype in the lung, caused by mutations in the CFTR gene. IL-8 and other proinflammatory mediators are elevated in the CF airway, and the immediate mechanism may depend on disease-specific stabilization of IL-8 mRNA in CF lung epithelial cells. MAPK signaling pathways impact directly on IL-8 protein expression in CF cells, and we have hypothesized that the mechanism may also involve stabilization of the IL-8 mRNA. To test this hypothesis, we have examined the effects of pharmacological and molecular inhibitors of p38, and downstream MK2, ERK1/2, and JNK, on stability of IL-8 mRNA in CF lung epithelial cells. We previously showed that tristetraprolin (TTP) was constitutively low in CF and that raising TTP destabilized the IL-8 mRNA. We therefore also tested these effects on CF lung epithelial cells stably expressing TTP. TTP binds to AU-rich elements in the 3′-UTR of the IL-8 mRNA. We find that inhibition of p38 and ERK1/2 reduces the stability of IL-8 mRNA in parental CF cells. However, neither intervention further lowers TTP-dependent destabilization of IL-8 mRNA. By contrast, inhibition of the JNK-2 pathway has no effect on IL-8 mRNA stability in parental CF cell, but rather increases the stability of the message in cells expressing high levels of TTP. However, we find that inhibition of ERK1/2 or p38 leads to suppression of the effect of JNK-2 inhibition on IL-8 mRNA stability. These data thus lend support to our hypothesis that constitutive MAPK signaling and proteasomal activity might also contribute, along with aberrantly lower TTP, to the proinflammatory phenotype in CF lung epithelial cells by increasing IL-8 mRNA stability and IL-8 protein expression.


2007 ◽  
Vol 293 (2) ◽  
pp. L480-L490 ◽  
Author(s):  
Jinming Zhao ◽  
Richart Harper ◽  
Aaron Barchowsky ◽  
Y. P. Peter Di

Activation and regulation of transcription factors (TFs) are the major mechanisms regulating changes in gene expression upon environmental exposure. Tobacco smoke (TS) is a complex mixture of chemicals, each of which could act through different signal cascades, leading to the regulation of distinct TFs and alterations in subsequent gene expression. We proposed that TS exposure affects inflammatory gene expression at the transcriptional level by modulating the DNA binding activities of TFs. To investigate transcriptional regulation upon TS exposure, a protein/DNA array was applied to screen TFs that are affected by TS exposure. This array-based screening allowed us to simultaneously detect 244 different TFs. Our results indicated that multiple TFs were rapidly activated upon TS exposure. DNA-binding activity of differentially expressed TFs was confirmed by EMSA. Our results showed that at least 20 TFs displayed more than twofold expressional changes after smoke treatment. Ten smoke-induced TFs, including NF-κB, VDR, ISRE, and RSRFC4, were involved in MAPK signaling pathways. The NF-κB family, which is involved in inflammation-induced gene activation, was selected for further study to characterize TS exposure-induced transcriptional activation. Western blot analysis and immunofluorescence microscopy indicated that TS exposure induced phosphorylation of IκB and translocation of NF-κB p65/p50 heterodimers into the nucleus. This activity was abrogated by the MAPK inhibitors PD98059 and U0126. Our results confirmed that activation of MAPK signaling pathways by TS exposure increased transcriptional activity of NF-κB. These data provide a potential mechanism for TS-induced inflammatory gene expression.


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