scholarly journals miR-26a-5p mediates TLR signaling pathway by targeting CTGF in LPS-induced alveolar macrophage

2020 ◽  
Vol 40 (6) ◽  
Author(s):  
Chunyan Li ◽  
Tingfeng Han ◽  
Run Li ◽  
Liming Fu ◽  
Lei Yue
Keyword(s):  
Cell Viability ◽  
Signaling Pathway ◽  
Alveolar Macrophages ◽  
Cell Model ◽  
Severe Pneumonia ◽  
Normal Group ◽  
Expression Level ◽  
Model Group ◽  
Tlr Signaling ◽  
Tlr Signaling Pathway

Abstract To explore the regulation mechanism of miR-26a-5p and connective tissue growth factor (CTGF) in lipopolysaccharide (LPS)-induced alveolar macrophages, which is a severe pneumonia cell model. MH-S cells were grouped into Normal group, Model group, negative control (NC) group, miR-26a-5p mimic group, oe-CTGF group, miR-26a-5p mimic + oe-CTGF group. The expression level of miR-26a-5p, CTGF and Toll-like receptor (TLR) signaling related molecules (TLR2, TLR4 and nuclear factor-κB p65) were detected by qRT-PCR and WB, respectively. The cell viability and apoptosis rate were detected by methyl thiazolyl tetrazolium (MTT) and flow cytometry, respectively. Compared with the Normal group, the expression level of miR-26a-5p was significantly decreased, while CTGF protein level was significantly increased in the Model group. Compared with the Model group, MH-S cells with miR-26a-5p overexpression showed enhanced cell viability, decreased apoptosis rate, declined expression level of TLR signaling related molecules and reduced level of tumor necrosis factor-α (TNF-α), interleukin (IL) 6 (IL-6) and IL-1β, while those with CTGF overexpression had an opposite phenotype. In conclusion, miR-26a-5p can inhibit the expression of CTGF and mediate TLR signaling pathway to inhibit the cell apoptosis and reduce the expression of proinflammatory cytokines in alveolar macrophages which is a cell model of severe pneumonia.

scholarly journals MicroRNA-34a Inhibition of the TLR Signaling Pathway Via CXCL10 Suppresses Breast Cancer Cell Invasion and Migration

2018 ◽  
Vol 46 (3) ◽  
pp. 1286-1304 ◽  
Author(s):  
Min Xu ◽  
Dong Li ◽  
Chen Yang ◽  
Jian-Song Ji
Keyword(s):  
Breast Cancer ◽  
Signaling Pathway ◽  
Migration And Invasion ◽  
Loss Of Function ◽  
Breast Tumorigenesis ◽  
Tlr Signaling ◽  
T47d Cells ◽  
Tlr Signaling Pathway ◽  
Mcf 7

Background/Aims: Breast cancer (BC) starts as a local disease, but it can metastasize to the lymph nodes and distant organs. However, the metastatic process is still poorly understood. The mRNA microarray datasets GSE26910 and GSE33447 show that CXCL10 is up-regulated in BC, and the microRNA microarray dataset GSE38167 and a network meta-analysis of microRNA expression profile studies in human BC suggest that microRNA-34a (miR-34a) is down-regulated in BC. CXCL10 was predicted as a target of miR-34a by microRNA.org. In this study, we uncovered a CXCL10-independent mechanism by which miR-34a exerts its antimetastatic activity in BC. Methods: To investigate the clinical significance of miR-34a in BC, we collected cancer tissues and paracancerous tissues from 258 patients with BC. In addition, a series of inhibitors, mimics, and siRNAs was introduced into MCF-7 and T47D cells to validate the regulatory mechanisms by which miR-34a regulates CXCL10. Next, to better understand the pivotal role of TLR signaling pathway inhibition in MCF-7 and T47D cells, we blocked the TLR signaling pathway using OxPAPC, an antagonist of TLR signaling. Results: Among BC patients, miR-34a was down-regulated, CXCL10 was up-regulated, and the TLR signaling pathway was activated. Determination of luciferase activity revealed that CXCL10 was a target of miR-34a. Through gain- and loss-of-function studies, miR-34a was demonstrated to negatively regulate CXCL10; inhibit activation of the TLR signaling pathway; significantly suppress in vitro cell proliferation, migration, and invasion; and induce apoptosis. Conclusion: Our findings suggest that functional loss or suppression of the tumor suppressor CXCL10 due to induction of miR-34a leads to inhibition of the TLR signaling pathway during breast tumorigenesis, providing a novel target for the molecular treatment of breast malignancies.

scholarly journals NF-κB mediates lipopolysaccharide-induced alternative pre-mRNA splicing of MyD88 in mouse macrophages

2020 ◽  
Vol 295 (18) ◽  
pp. 6236-6248
Author(s):  
Frank Fang-Yao Lee ◽  
Kevin Davidson ◽  
Chelsea Harris ◽  
Jazalle McClendon ◽  
William J. Janssen ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Chronic Inflammation ◽  
Mrna Splicing ◽  
Dominant Negative ◽  
Mrna Isoforms ◽  
Inflammatory Signaling ◽  
Tlr Signaling ◽  
Tlr4 Agonist ◽  
Alternatively Spliced ◽  
Tlr Signaling Pathway

Although a robust inflammatory response is needed to combat infection, this response must ultimately be terminated to prevent chronic inflammation. One mechanism that terminates inflammatory signaling is the production of alternative mRNA splice forms in the Toll-like receptor (TLR) signaling pathway. Whereas most genes in the TLR pathway encode positive mediators of inflammatory signaling, several, including that encoding the MyD88 signaling adaptor, also produce alternative spliced mRNA isoforms that encode dominant-negative inhibitors of the response. Production of these negatively acting alternatively spliced isoforms is induced by stimulation with the TLR4 agonist lipopolysaccharide (LPS); thus, this alternative pre-mRNA splicing represents a negative feedback loop that terminates TLR signaling and prevents chronic inflammation. In the current study, we investigated the mechanisms regulating the LPS-induced alternative pre-mRNA splicing of the MyD88 transcript in murine macrophages. We found that 1) the induction of the alternatively spliced MyD88 form is due to alternative pre-mRNA splicing and not caused by another RNA regulatory mechanism, 2) MyD88 splicing is regulated by both the MyD88- and TRIF-dependent arms of the TLR signaling pathway, 3) MyD88 splicing is regulated by the NF-κB transcription factor, and 4) NF-κB likely regulates MyD88 alternative pre-mRNA splicing per se rather than regulating splicing indirectly by altering MyD88 transcription. We conclude that alternative splicing of MyD88 may provide a sensitive mechanism that ensures robust termination of inflammation for tissue repair and restoration of normal tissue homeostasis once an infection is controlled.

scholarly journals PRC1 promotes GLI1-dependent osteopontin expression in association with the Wnt/β-catenin signaling pathway and aggravates liver fibrosis

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Shenzong Rao ◽  
Jie Xiang ◽  
Jingsong Huang ◽  
Shangang Zhang ◽  
Min Zhang ◽  
...  
Keyword(s):  
Liver Fibrosis ◽  
Western Blot ◽  
Cell Viability ◽  
Signaling Pathway ◽  
Cell Model ◽  
Stellate Cell ◽  
Underlying Mechanism ◽  
Histopathological Analysis ◽  
Osteopontin Expression

Abstract Background PRC1 (Protein regulator of cytokinesis 1) regulates microtubules organization and functions as a novel regulator in Wnt/β-catenin signaling pathway. Wnt/β-catenin is involved in development of liver fibrosis (LF). We aim to investigate effect and mechanism of PRC1 on liver fibrosis. Methods Carbon tetrachloride (CCl4)-induced mice LF model was established and in vitro cell model for LF was induced by mice primary hepatic stellate cell (HSC) under glucose treatment. The expression of PRC1 in mice and cell LF models was examined by qRT-PCR (quantitative real-time polymerase chain reaction), western blot and immunohistochemistry. MTT assay was used to detect cell viability, and western blot to determine the underlying mechanism. The effect of PRC1 on liver pathology was examined via measurement of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and hydroxyproline, as well as histopathological analysis. Results PRC1 was up-regulated in CCl4-induced mice LF model and activated HSC. Knockdown of PRC1 inhibited cell viability and promoted cell apoptosis of activated HSC. PRC1 expression was regulated by Wnt3a signaling, and PRC1 could regulate downstream β-catenin activation. Moreover, PRC1 could activate glioma-associated oncogene homolog 1 (GLI1)-dependent osteopontin expression to participate in LF. Adenovirus-mediated knockdown of PRC1 in liver attenuated LF and reduced collagen deposition. Conclusions PRC1 aggravated LF through regulating Wnt/β-catenin mediated GLI1-dependent osteopontin expression, providing a new potential therapeutic target for LF treatment.

scholarly journals Functional Toll-Like Receptors (TLRs) Are Expressed by a Majority of Primary Human Acute Myeloid Leukemia Cells and Inducibility of the TLR Signaling Pathway Is Associated with a More Favorable Phenotype

Cancers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 973 ◽  
Author(s):  
Annette K. Brenner ◽  
Øystein Bruserud
Keyword(s):  
Acute Myeloid Leukemia ◽  
Signaling Pathway ◽  
Myeloid Leukemia ◽  
Receptor Expression ◽  
Cytokine Secretion ◽  
Toll Like Receptors ◽  
Tlr Signaling ◽  
General Response ◽  
Tlr Signaling Pathway ◽  
Acute Myeloid

Acute myeloid leukemia (AML) is a highly heterogeneous disease with regard to biological characteristics and receptor expression. Toll-like receptors (TLRs) are upstream to the transcription factor NFκB and part of the innate immune system. They are differentially expressed on AML blasts, and during normal hematopoiesis they initiate myeloid differentiation. In this study, we investigated the response upon TLR stimulation in an AML cohort (n = 83) by measuring the increase of NFκB-mediated cytokine secretion. We observed that TLR4 is readily induced in most patients, while TLR1/2 response was more restricted. General response to TLR stimulation correlated with presence of nucleophosmin gene mutations, increased mRNA expression of proteins, which are part of the TLR signaling pathway and reduced expression of transcription-related proteins. Furthermore, signaling via TLR1/2 appeared to be linked with prolonged patient survival. In conclusion, response upon TLR stimulation, and especially TLR1/2 induction, seems to be part of a more favorable phenotype, which also is characterized by higher basal cytokine secretion and a more mature blast population.

scholarly journals The Effects of Paclitaxel and Metformin and Combined Treatments on TLR Signaling Pathway on MDA-MB-231 Breast Cancer Cell Lines

Proceedings ◽  
2017 ◽  
Vol 1 (10) ◽  
pp. 1016 ◽  
Author(s):  
Melike Ozgul ◽  
Elgin Turkoz Uluer ◽  
Tuna Onal ◽  
Damla Akogullari ◽  
Kemal Ozbilgin ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Signaling Pathway ◽  
Cell Lines ◽  
Cancer Cell ◽  
Breast Cancer Cell ◽  
Cancer Cell Lines ◽  
Breast Cancer Cell Lines ◽  
Combined Treatments ◽  
Tlr Signaling ◽  
Tlr Signaling Pathway

scholarly journals Acupuncture at Back-Shu and Front-Mu Acupoints Prevents Gastric Ulcer by Regulating the TLR4/MyD88/NF-κB Signaling Pathway

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Li Li ◽  
Hao Zang ◽  
Yang Jiang ◽  
Yue Zhang ◽  
Shuangshuang Mu ◽  
...  
Keyword(s):  
Gastric Ulcer ◽  
Signaling Pathway ◽  
Water Immersion ◽  
Serum Levels ◽  
Normal Group ◽  
Inhibition Rate ◽  
Model Group ◽  
Extracellular Signals ◽  
Tnf Α ◽  
Histopathological Score

Purpose. To assess the preventive effects of acupuncture at back-shu and front-mu acupoints on rats with restraint water-immersion stress (RWIS)-induced gastric ulcer. Methods. Thirty-six rats were randomly divided into four groups for 10 days of treatment as follows: the normal group received no treatment; the model group received RWIS-induced gastric ulcer; the omeprazole group was administered omeprazole orally every 2 days; and the electroacupuncture group received electroacupuncture at the RN12 and BL21 acupoints every 2 days. After 10 days of treatment, except for the normal group, all rats were induced with gastric ulcer by RWIS for 3 h. The ulcer index (UI), ulcer inhibition rate, and histopathological score were calculated. We determined the levels of tumor necrosis factor (TNF)-α and interleukin (IL)-6 in serum, and the activities of myeloperoxidase (MPO), malondialdehyde (MDA), superoxide dismutase (SOD), nitric oxide (NO), and glutathione peroxidase (GSH-Px) in serum and gastric tissues. Protein expression of MyD88, nuclear factor (NF)-κB (p65), and toll-like receptor (TLR) 4 was quantified in gastric tissues. Results. The electroacupuncture and omeprazole groups were equivalent in terms of UI, ulcer inhibition rate, and histopathological score. The serum levels of TNF-α and IL-6 were significantly lower in the electroacupuncture group compared with the omeprazole group ( P  < 0.05). Compared with the model group, there were significant changes in the levels of NO, MPO, GSH-Px, and MDA in all other groups, while the expression of TLR4, MyD88, and NF-κB p65 in gastric tissue decreased significantly in the electroacupuncture group. The expression of TLR4 was substantially lower in the electroacupuncture group compared with the omeprazole group. Conclusion. Acupuncture at back-shu and front-mu acupoints played a role in preventing gastric ulcer by inhibiting extracellular signals, stimulating kinases in serum and gastric tissues, and activating the inhibition of the TLR4 signaling pathway.

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