scholarly journals Evidence for the Involvement of Toll-Like Receptor 4 (TLR4)-Mediated Apoptosis in Gynecological Cancers

2016 ◽  
Author(s):  
Jinyoung Won ◽  
Youngjeon Lee ◽  
Kyu-Tae Chang ◽  
Yonggeun Hong
Keyword(s):  
Cancer Cells ◽  
Apoptotic Cell ◽  
Gynecological Cancer ◽  
Mechanism Analysis ◽  
Toll Like Receptor ◽  
Gynecological Cancers ◽  
Toll Like Receptor 4 ◽  
Tlr4 Agonist ◽  
Apoptotic Activity ◽  
Tlr4 Activation

Toll-like receptor 4 (TLR4) is a member of the TLR family. Members of the TLR family play an important role in innate immune responses and are induced by recognition of pathogen-associated molecular patterns. They are also involved in cell proliferation and apoptosis in cancer. We investigated the role of TLR4 in apoptotic cell death in gynecological cancer cells; gynecological cancer is associated with infertility and spontaneous abortion. To examine the effect of TLR4 activation on apoptotic signaling in cancer cells, cultured primary cancer cells were treated with the TLR4 agonist lipopolysaccharide (LPS). The morphology of cancer cells was compared with normal myometrial cells. Enhanced growth rate and loss of contact inhibition with cellular overlap was observed in the cancer cells. The molecular mechanism analysis revealed differential expression of tumor suppressor genes in LPS-treated cancer cells. The expression of apoptosis-related caspase-3 was increased significantly in cancer cells with TLR4 activation after exposure to LPS. Taken together, these results suggest the pro-apoptotic activity of TLR4 as a potential therapeutic target for the treatment of gynecological cancers.

scholarly journals Toll-Like Receptor 4 Activation Prevents Rat Cardiac Fibroblast Death Induced by Simulated Ischemia/Reperfusion

2021 ◽  
Vol 8 ◽  
Author(s):  
Pablo Parra-Flores ◽  
Jenaro Espitia-Corredor ◽  
Claudio Espinoza-Pérez ◽  
Cristian Queirolo ◽  
Pedro Ayala ◽  
...  
Keyword(s):  
Cell Viability ◽  
Apoptotic Cell ◽  
Ischemia Reperfusion ◽  
Protective Effects ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4 ◽  
Trypan Blue Exclusion ◽  
Simulated Ischemia ◽  
Tlr4 Activation

Death of cardiac fibroblasts (CFs) by ischemia/reperfusion (I/R) has major implications for cardiac wound healing. In in vivo models of myocardial infarction, toll-like receptor 4 (TLR4) activation has been reported as a cardioprotector; however, it remains unknown whether TLR4 activation can prevent CF death triggered by simulated I/R (sI/R). In this study, we analyzed TLR4 activation in neonate CFs exposed to an in vitro model of sI/R and explored the participation of the pro-survival kinases Akt and ERK1/2. Simulated ischemia was performed in a free oxygen chamber in an ischemic medium, whereas reperfusion was carried out in normal culture conditions. Cell viability was analyzed by trypan blue exclusion and the MTT assay. Necrotic and apoptotic cell populations were evaluated by flow cytometry. Protein levels of phosphorylated forms of Akt and ERK1/2 were analyzed by Western blot. We showed that sI/R triggers CF death by necrosis and apoptosis. In CFs exposed only to simulated ischemia or only to sI/R, blockade of the TLR4 with TAK-242 further reduced cell viability and the activation of Akt and ERK1/2. Preconditioning with lipopolysaccharide (LPS) or treatment with LPS in ischemia or reperfusion was not protective. However, LPS incubation during both ischemia and reperfusion periods prevented CF viability loss induced by sI/R. Furthermore, LPS treatment reduced the sub-G1 population, but not necrosis of CFs exposed to sI/R. On the other hand, the protective effects exhibited by LPS were abolished when TLR4 was blocked and Akt and ERK1/2 were inhibited. In conclusion, our results suggest that TLR4 activation protects CFs from apoptosis induced by sI/R through the activation of Akt and ERK1/2 signaling pathways.

scholarly journals Lycopene Inhibits Toll-Like Receptor 4-Mediated Expression of Inflammatory Cytokines in House Dust Mite-Stimulated Respiratory Epithelial Cells

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3127
Author(s):  
Jiyeon Choi ◽  
Joo Weon Lim ◽  
Hyeyoung Kim
Keyword(s):  
Epithelial Cells ◽  
A549 Cells ◽  
Cytokine Expression ◽  
Ros Production ◽  
Toll Like Receptor ◽  
Respiratory Epithelial Cells ◽  
Toll Like Receptor 4 ◽  
Mitochondrial Ros ◽  
Tlr4 Activation ◽  
Respiratory Epithelial

House dust mites (HDM) are critical factors in airway inflammation. They activate respiratory epithelial cells to produce reactive oxygen species (ROS) and activate Toll-like receptor 4 (TLR4). ROS induce the expression of inflammatory cytokines in respiratory epithelial cells. Lycopene is a potent antioxidant nutrient with anti-inflammatory activity. The present study aimed to investigate whether HDM induce intracellular and mitochondrial ROS production, TLR4 activation, and pro-inflammatory cytokine expression (IL-6 and IL-8) in respiratory epithelial A549 cells. Additionally, we examined whether lycopene inhibits HDM-induced alterations in A549 cells. The treatment of A549 cells with HDM activated TLR4, induced the expression of IL-6 and IL-8, and increased intracellular and mitochondrial ROS levels. TAK242, a TLR4 inhibitor, suppressed both HDM-induced ROS production and cytokine expression. Furthermore, lycopene inhibited the HDM-induced TLR4 activation and cytokine expression, along with reducing the intracellular and mitochondrial ROS levels in HDM-treated cells. These results collectively indicated that the HDM induced TLR4 activation and increased intracellular and mitochondrial ROS levels, thus resulting in the induction of cytokine expression in respiratory epithelial cells. The antioxidant lycopene could inhibit HDM-induced cytokine expression, possibly by suppressing TLR4 activation and reducing the intracellular and mitochondrial ROS levels in respiratory epithelial cells.

scholarly journals The Role of Toll-Like Receptor 4 in Infectious and Noninfectious Inflammation

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Monica Molteni ◽  
Sabrina Gemma ◽  
Carlo Rossetti
Keyword(s):  
Tissue Injury ◽  
Sterile Inflammation ◽  
Research Progress ◽  
Toll Like Receptor ◽  
Proinflammatory Response ◽  
Toll Like Receptor 4 ◽  
The Family ◽  
Tlr4 Activation ◽  
Molecular Patterns

Toll-like receptor 4 (TLR4) belongs to the family of pattern recognition receptors (PRRs). They are highly conserved receptors that recognize conserved pathogen-associated molecular patterns (PAMPs), thus representing the first line of defense against infections. TLR4 has been long recognized as the sensing receptor for gram-negative lipopolysaccharide (LPS). In addition, it also binds endogenous molecules produced as a result of tissue injury. Hence, TLR4 represents a key receptor on which both infectious and noninfectious stimuli converge to induce a proinflammatory response. TLR4-mediated inflammation, triggered by exogenous or endogenous ligands, is also involved in several acute and chronic diseases, having a pivotal role as amplifier of the inflammatory response. This review focuses on the research progress about the role of TLR4 activation in infectious and noninfectious (e.g., sterile) inflammation and the effects of TLR4 signaling in some pathological conditions.

Effects of Amygdalin on TLR4/NF-αB Signaling Pathway-Mediated Proliferation and Apoptosis of Gastric Cancer Cells

2021 ◽  
Vol 20 (1) ◽  
pp. 153-158
Author(s):  
Abulajiang Abudoukelimu ◽  
Xinhui Yang ◽  
Lei Ge ◽  
Xiangyue Zeng ◽  
Yin Shu ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Cancer Cells ◽  
Signaling Pathway ◽  
B Cell Lymphoma ◽  
Toll Like Receptor ◽  
Gastric Cancer Cells ◽  
Toll Like Receptor 4 ◽  
Proliferation And Apoptosis ◽  
High Incidence Rate ◽  
Factor Α

Gastric cancer is a highly malignant tumor of the digestive tract with high incidence rate and mortality. In the present study, we have shown decreased cell proliferation, increased apoptosis, and expression of proinflammatory cytokines (Interleukin-6, Interleukin-1β, and Tumor necrosis factor-α) in gastric cancer cells MGC-803 by amygdalin. Also, amygdalin treatment significantly reduced expression of the mRNA and protein for B-cell lymphoma 2 protein, CyclinD1, toll-like receptor 4, and REL-associated protein involved in NF-κB heterodimer formation in MGC-803 cells. In summary, amygdalin inhibits the proliferation of gastric cancer cells MGC-803 and promotes cell apoptosis by regulating the toll-like receptor 4/ nuclear factor-kappa B signaling pathway.

scholarly journals 4296 Targeting ERG Through Toll-Like Receptor 4 in Prostate Cancer

2020 ◽  
Vol 4 (s1) ◽  
pp. 17-17
Author(s):  
Ben Greulich ◽  
Josh Plotnik ◽  
Peter Hollenhorst
Keyword(s):  
Prostate Cancer ◽  
Transcription Factor ◽  
Protein Interactions ◽  
Treatment Options ◽  
Clonogenic Survival ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4 ◽  
Functional Assays ◽  
Prostate Cells ◽  
Tlr4 Activation

OBJECTIVES/GOALS: The objective of this research was to learn how the oncogenic transcription factor, ERG, is regulated in prostate cancer. If we could learn how ERG is regulated and which genes are important for its oncogenic phenotype in prostate cells, we could design new therapeutic strategies against ERG, which has proven to be difficult to target. METHODS/STUDY POPULATION: We conducted an shRNA screen in prostate cells to determine candidate genes and pathways that are important for ERG function. To validate the findings of the screen, we performed a variety of cell-based functional assays, including trans-well migration, wound healing, and clonogenic survival assays. To further investigate the mechanism between ERG and the genes revealed by the screen, we performed biochemical and molecular biology experiments such as Western blotting and qRT-PCR for protein and mRNA expression, co-immunoprecipitation assays to determine protein-protein interactions, and chromatin immunoprecipitation (ChIP-qPCR) to determine transcription factor binding to DNA sites. RESULTS/ANTICIPATED RESULTS: The screen revealed that genes involved in the toll-like receptor 4 (TLR4) pathway are important for ERG-mediated migration. We tested the effect of a TLR4 inhibitor on ERG function and observed decreased migration and clonogenic survival exclusively in ERG-positive cells. Expression of pMEK and pERG was reduced when TLR4 was inhibited, which suggests a mechanism in which TLR4 upregulates pMEK, leading to the phosphorylation and activation of ERG. This is supported by functional assays in which cells expressing a phosphomimetic ERG are resistant to the TLR4 inhibitor. We demonstrated that ERG drives the transcription of TLR4 and its endogenous ligands HSPA8 and BGN. Therefore, ERG can sensitize the cell to TLR4 activation by increasing the number of receptors as well as providing the ligands needed for stimulation. DISCUSSION/SIGNIFICANCE OF IMPACT: This research provides a new therapeutic pathway for treating ERG-positive patients through TLR4 inhibition. This can be beneficial because many patients become resistant to the standard therapy, leaving very few treatment options. TLR4-based therapies could provide an alternative for patients who have developed resistance.

scholarly journals p62 is Negatively Implicated in the TRAF6-BECN1 Signaling Axis for Autophagy Activation and Cancer Progression by Toll-Like Receptor 4 (TLR4)

Cells ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 1142 ◽  
Author(s):  
Mi-Jeong Kim ◽  
Yoon Min ◽  
Ji Seon Im ◽  
Juhee Son ◽  
Joo Sang Lee ◽  
...  
Keyword(s):  
Cell Migration ◽  
Cancer Cells ◽  
Cancer Cell ◽  
A549 Cells ◽  
Migration And Invasion ◽  
Cancer Cell Migration ◽  
Toll Like Receptor ◽  
Toll Like Receptor 4 ◽  
Cell Migration And Invasion ◽  
Signaling Axis

Toll-like receptors (TLRs) induce the activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and autophagy through the TNF (Tumor necrosis factor) receptor-associated factor 6 (TRAF6)-evolutionarily conserved signaling intermediate in Toll pathways (ECSIT) and TRAF6-BECN1 signaling axes, respectively. Having shown that p62 negatively regulates Toll-like receptor 4 (TLR4)-mediated signaling via TRAF6-ECSIT signaling axis, we herein investigated whether p62 is functionally implicated in the TRAF6-BECN1 signaling axis, thereby regulating cancer cell migration and invasion. p62 interacted with TRAF6 and BECN1, to interrupt the functional associations required for TRAF6-BECN1 complex formation, leading to inhibitions of BECN1 ubiquitination and autophagy activation. Importantly, p62-deficient cancer cells, such as p62-knockdown (p62KD) SK-HEP-1, p62KD MDA-MB-231, and p62-knockout (p62KO) A549 cells, showed increased activation of autophagy induced by TLR4 stimulation, suggesting that p62 negatively regulates autophagy activation. Moreover, these p62-deficient cancer cells exhibited marked increases in cell migration and invasion in response to TLR4 stimulation. Collectively, these results suggest that p62 is negatively implicated in the TRAF6-BECN1 signaling axis, thereby inhibiting cancer cell migration and invasion regulated by autophagy activation in response to TLR4 stimulation.

Toll-like receptor 4 ligation confers chemoresistance to docetaxel on PC-3 human prostate cancer cells

2012 ◽  
Vol 28 (4) ◽  
pp. 269-277 ◽  
Author(s):  
Yuntao Zhang ◽  
Yong Wang ◽  
Jianlin Yuan ◽  
Weijun Qin ◽  
Fei Liu ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cancer Cells ◽  
Human Prostate ◽  
Human Prostate Cancer ◽  
Toll Like Receptor ◽  
Prostate Cancer Cells ◽  
Toll Like Receptor 4
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