scholarly journals Mitochondrial DNA leakage induces odontoblast inflammation via the cGAS-STING pathway

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Lu Zhou ◽  
Yi-Fei Zhang ◽  
Fu-Hua Yang ◽  
Han-Qing Mao ◽  
Zhi Chen ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Real Time ◽  
Inflammatory Cytokines ◽  
Real Time Pcr ◽  
Nuclear Translocation ◽  
Inflammatory Responses ◽  
Immunofluorescent Staining ◽  
Bacterial Invasion ◽  
Sting Pathway ◽  
Pro Inflammatory Cytokines

Abstract Background Mitochondrial DNA (mtDNA) is a vital driver of inflammation when it leaks from damaged mitochondria into the cytosol. mtDNA stress may contribute to cyclic GMP-AMP synthase (cGAS) stimulator of interferon genes (STING) pathway activation in infectious diseases. Odontoblasts are the first cells challenged by cariogenic bacteria and involved in maintenance of the pulp immune and inflammatory responses to dentine-invading pathogens. In this study, we investigated that mtDNA as an important inflammatory driver participated in defending against bacterial invasion via cGAS-STING pathway in odontoblasts. Methods The normal tissues, caries tissues and pulpitis tissues were measured by western blotting and immunohistochemical staining. Pulpitis model was built in vitro to evaluated the effect of the cGAS-STING pathway in odontoblast-like cell line (mDPC6T) under inflammation. Western blot and real-time PCR were performed to detect the expression of cGAS-STING pathway and pro-inflammatory cytokines. The mitochondrial function was evaluated reactive oxygen species (ROS) generated by mitochondria using MitoSOX Red dye staining. Cytosolic DNA was assessed by immunofluorescent staining and real-time PCR in mDPC6T cells after LPS stimulation. Furthermore, mDPC6T cells were treated with ethidium bromide (EtBr) to deplete mtDNA or transfected with isolated mtDNA. The expression of cGAS-STING pathway and pro-inflammatory cytokines were measured. Results The high expression of cGAS and STING in caries and pulpitis tissues in patients, which was associated with inflammatory progression. The cGAS-STING pathway was activated in inflamed mDPC6T. STING knockdown inhibited the nuclear import of p65 and IRF3 and restricted the secretion of the inflammatory cytokines CXCL10 and IL-6 induced by LPS. LPS caused mitochondrial damage in mDPC6T, which promoted mtDNA leakage into the cytosol. Depletion of mtDNA inhibited the cGAS-STING pathway and nuclear translocation of p65 and IRF3. Moreover, repletion of mtDNA rescued the inflammatory response, which was inhibited by STING knockdown. Conclusion Our study systematically identified a novel mechanism of LPS-induced odontoblast inflammation, which involved mtDNA leakage from damaged mitochondria into the cytosol stimulating the cGAS-STING pathway and the inflammatory cytokines IL-6 and CXCL10 secretion. The mtDNA-cGAS-STING axis could be a potent therapeutic target to prevent severe bacterial inflammation in pulpitis. Graphic abstract

scholarly journals Mitochondrial DNA drives noncanonical inflammation activation via cGAS–STING signaling pathway in retinal microvascular endothelial cells

2020 ◽  
Author(s):  
Yue Guo ◽  
Ruiping Gu ◽  
Dekang Gan ◽  
Fangyuan Hu ◽  
Gang Li ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Transcription Factor ◽  
Mitochondrial Dna ◽  
Mrna Expression ◽  
Real Time ◽  
Proinflammatory Cytokines ◽  
Real Time Pcr ◽  
Nuclear Translocation ◽  
Immunofluorescent Staining ◽  
Microvascular Endothelial Cells

Abstract Background Pathological stimuli cause mitochondrial damage and leakage of mitochondrial DNA (mtDNA) into the cytosol, as demonstrated in many cell types. The cytosolic mtDNA then drives the activation of noninfectious inflammation. Retinal microvascular endothelial cells (RMECs) play an important role in the inner endothelial blood–retinal barrier (BRB). RMEC dysfunction frequently occurs in posterior-segment eye diseases, causing loss of vision. In this study, we investigated the involvement of cytosolic mtDNA in noninfectious immune inflammation in RMECs under pathological stimuli. Methods RMECs were stimulated with 100 ng/ml lipopolysaccharide (LPS), 200 μM hydrogen peroxide (H 2 O 2 ), or 25 mM d -glucose. After 24 h, immunofluorescent staining was used to detect the opening of the mitochondrial permeability transition pore (MPTP). Cytosolic mtDNA was detected with immunofluorescent staining and PCR after stimulation. mtDNA was then isolated and used to transfect RMECs in vitro, and the protein levels of cGAS were evaluated with western blotting. Real-time PCR was used to examine cGAS mRNA expression levels at different time points after mtDNA stimulation. The activation of STING was detected with immunofluorescent staining 6 h after mtDNA stimulation. Western blotting was used to determine the expression of STING and IFNβ, the phosphorylation status of TBK1, IRF3, and nuclear factor-κB (NF-κB) P65, and the nuclear translocation of IRF3 and NF-κB P65 at 0, 3, 6, 12, and 24 h. The mRNA expression of proinflammatory cytokines CCL4, CXCL10, IFNB1, and transcription factor IRF1 were determined with real-time PCR, together with the concentrations of intercellular adhesion molecule 1 (ICAM-1) mRNA. Results Pathological stimuli caused mtDNA to leak into the cytosol by opening the MPTP in RMECs after 24 h. Cytosolic mtDNA regulated the expression of cGAS and the distribution of STING in RMECs. It promoted ICAM-1, STING, and IFNβ expression, TBK1, IRF3, and NF-κB phosphorylation and the nuclear translocation in RMECs at 12 and 24 h after its transfection. The mRNAs of proinflammatory cytokines CCL4, CXCL10, IFNB1, and transcription factor IRF1 were significantly elevated at 12 and 24 h after mtDNA stimulation. Conclusions Pathological stimulation induces mtDNA escape into the cytosol of RMECs. This cytoplasmic mtDNA is recognized by the DNA sensor cGAS, increasing the expression of inflammatory cytokines through the STING–TBK1 signaling pathway.

scholarly journals Mitochondrial DNA drives noncanonical inflammation activation via cGAS–STING signaling pathway in retinal microvascular endothelial cells

2020 ◽  
Author(s):  
Yue Guo ◽  
Ruiping Gu ◽  
Dekang Gan ◽  
Fangyuan Hu ◽  
Gang Li ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Mitochondrial Dna ◽  
Mrna Expression ◽  
Real Time ◽  
Signaling Pathway ◽  
Proinflammatory Cytokines ◽  
Real Time Pcr ◽  
Nuclear Translocation ◽  
Immunofluorescent Staining ◽  
Microvascular Endothelial Cells

Abstract Background Pathological stimuli cause mitochondrial damage and leakage of mitochondrial DNA (mtDNA) into the cytosol, as demonstrated in many cell types. The cytosolic mtDNA then drives the activation of noninfectious inflammation. Retinal microvascular endothelial cells (RMECs) play an important role in the inner endothelial blood–retinal barrier (BRB). RMEC dysfunction frequently occurs in posterior-segment eye diseases, causing loss of vision. In this study, we investigated the involvement of cytosolic mtDNA in noninfectious immune inflammation in RMECs under pathological stimuli.Methods RMECs were stimulated with 100 ng/ml lipopolysaccharide (LPS), 200 μM hydrogen peroxide (H 2 O 2 ), or 25 mM d -glucose. After 24 h, immunofluorescent staining was used to detect the opening of the mitochondrial permeability transition pore (MPTP). Cytosolic mtDNA was detected with immunofluorescent staining and PCR after stimulation. mtDNA was then isolated and used to transfect RMECs in vitro, and the protein levels of cGAS were evaluated with western blotting. Real-time PCR was used to examine cGAS mRNA expression levels at different time points after mtDNA stimulation. The activation of STING was detected with immunofluorescent staining 6 h after mtDNA stimulation. Western blotting was used to determine the phosphorylation status of TBK1, IRF3, and nuclear factor-κB (NF-κB) P65, and the nuclear translocation of IRF3 and NF-κB P65 at 0, 3, 6, 12, and 24 h. The mRNA expression of proinflammatory cytokines CCL4, CXCL10, IRF1, and IFNB1 was determined with real-time PCR, together with the concentrations of intercellular adhesion molecule 1 (ICAM-1) mRNA.Results Pathological stimuli caused mtDNA to leak into the cytosol by opening the MPTP in RMECs after 24 h. Cytosolic mtDNA regulated the expression of cGAS and the distribution of STING in RMECs. It promoted TBK1, IRF3, and NF-κB phosphorylation and the nuclear translocation in RMECs at 12 and 24 h after its transfection. The mRNAs of proinflammatory cytokines CCL4, CXCL10, IRF1, and IFNB1 were significantly elevated at 12 and 24 h after mtDNA stimulation.Conclusions Pathological stimulation induces mtDNA escape into the cytosol of RMECs. This cytoplasmic mtDNA is recognized by the DNA sensor cGAS, increasing the expression of inflammatory cytokines through the STING–TBK1 signaling pathway.

scholarly journals Mitochondrial DNA drives noncanonical inflammation activation via cGAS–STING signaling pathway in retinal microvascular endothelial cells

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Yue Guo ◽  
Ruiping Gu ◽  
Dekang Gan ◽  
Fangyuan Hu ◽  
Gang Li ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Transcription Factor ◽  
Mitochondrial Dna ◽  
Mrna Expression ◽  
Real Time ◽  
Proinflammatory Cytokines ◽  
Real Time Pcr ◽  
Nuclear Translocation ◽  
Immunofluorescent Staining ◽  
Microvascular Endothelial Cells

Abstract Background Pathological stimuli cause mitochondrial damage and leakage of mitochondrial DNA (mtDNA) into the cytosol, as demonstrated in many cell types. The cytosolic mtDNA then drives the activation of noninfectious inflammation. Retinal microvascular endothelial cells (RMECs) play an important role in the inner endothelial blood–retinal barrier (BRB). RMEC dysfunction frequently occurs in posterior-segment eye diseases, causing loss of vision. In this study, we investigated the involvement of cytosolic mtDNA in noninfectious immune inflammation in RMECs under pathological stimuli. Methods RMECs were stimulated with 100 ng/ml lipopolysaccharide (LPS), 200 μM hydrogen peroxide (H2O2), or 25 mM d-glucose. After 24 h, immunofluorescent staining was used to detect the opening of the mitochondrial permeability transition pore (MPTP). Cytosolic mtDNA was detected with immunofluorescent staining and PCR after stimulation. mtDNA was then isolated and used to transfect RMECs in vitro, and the protein levels of cGAS were evaluated with western blotting. Real-time PCR was used to examine cGAS mRNA expression levels at different time points after mtDNA stimulation. The activation of STING was detected with immunofluorescent staining 6 h after mtDNA stimulation. Western blotting was used to determine the expression of STING and IFNβ, the phosphorylation status of TBK1, IRF3, and nuclear factor-κB (NF-κB) P65, and the nuclear translocation of IRF3 and NF-κB P65 at 0, 3, 6, 12, and 24 h. The mRNA expression of proinflammatory cytokines CCL4, CXCL10, and IFNB1, and transcription factor IRF1 were determined with real-time PCR, together with the concentrations of intercellular adhesion molecule 1 (ICAM-1) mRNA. Results Pathological stimuli caused mtDNA to leak into the cytosol by opening the MPTP in RMECs after 24 h. Cytosolic mtDNA regulated the expression of cGAS and the distribution of STING in RMECs. It promoted ICAM-1, STING and IFNβ expression, TBK1, IRF3, and NF-κB phosphorylation and the nuclear translocation in RMECs at 12 and 24 h after its transfection. The mRNAs of proinflammatory cytokines CCL4, CXCL10, and IFNB1, and transcription factor IRF1 were significantly elevated at 12 and 24 h after mtDNA stimulation. Conclusions Pathological stimulation induces mtDNA escape into the cytosol of RMECs. This cytoplasmic mtDNA is recognized by the DNA sensor cGAS, increasing the expression of inflammatory cytokines through the STING–TBK1 signaling pathway.

scholarly journals MiR-200c-3p inhibits LPS-induced M1 polarization of BV2 cells by targeting RIP2

2022 ◽  
Author(s):  
Lei Zhao ◽  
Xiaosong Liu ◽  
Jiankai Yang ◽  
Xiaoliang Wang ◽  
Xiaomeng Liu ◽  
...  
Keyword(s):  
Inflammatory Cytokines ◽  
Nuclear Translocation ◽  
Inflammatory Responses ◽  
Luciferase Reporter ◽  
Dependent Manner ◽  
M1 Polarization ◽  
Bv2 Cells ◽  
M1 Phenotype ◽  
Lps Treatment ◽  
Pro Inflammatory Cytokines

Abstract Background Microglia are important immune cells, which can be induced by lipopolysaccharide (LPS) into M1 phenotype that express pro-inflammatory cytokines. Some studies have shown that microRNAs play critical roles in microglial activation. Objective This study was designed to investigate the role of miR-200c-3p in regulating inflammatory responses of LPS-treated BV2 cells. Methods The expression of miR-200c-3p in BV2 cells was detected by real-time PCR. Receptor-interacting protein 2 (RIP2) was predicted as a target gene of miR-200c-3p. Their relationship was verified by dual-luciferase reporter assay. The function of miR-200c-3p and RIP2 in microglial polarization and NF-κB signaling was further evaluated. Results LPS treatment reduced miR-200c-3p expression in a dose-dependent and time-dependent manner in BV2 cells. LPS treatment increased the expression of M1 phenotype markers inducible nitric oxide synthase (iNOS) and major histocompatibility complex class (MHC)-II, promoted the release of pro-inflammatory cytokines interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α, and enhanced the nuclear translocation and phosphorylation of nuclear factor-kappaB (NF-κB) p65. Reversely, miR-200c-3p mimics down-regulated the levels of these inflammatory factors. Furthermore, RIP2 was identified to be a direct target of miR-200c-3p. RIP2 knockdown had a similar effect to miR-200c-3p mimics. Overexpression of RIP2 eliminated the inhibitory effect of miR-200c-3p on LPS-induced M1 polarization and NF-κB activation in BV2 cells. Conclusions MiR-200c-3p mimics suppressed LPS-induced microglial M1 polarization and NF-κB activation by targeting RIP2. MiR-200c-3p/RIP2 might be a potential therapeutic target for the treatment of neuroinflammation-associated diseases.

scholarly journals Isoimperatorin exerts anti-inflammatory activity by targeting the LPS-TLR4/MD-2-NF-κB pathway

2021 ◽  
Vol 19 ◽  
pp. 205873922110005
Author(s):  
Guirong Chen ◽  
Yunong Liu ◽  
Yubin Xu ◽  
Mingbo Zhang ◽  
Song Guo ◽  
...  
Keyword(s):  
Molecular Docking ◽  
Real Time ◽  
Signaling Pathway ◽  
Western Blotting ◽  
Inflammatory Cytokines ◽  
Real Time Pcr ◽  
Inflammatory Responses ◽  
Inflammatory Activity ◽  
Tnf Α ◽  
Anti Inflammatory

Isoimperatorin (QHS) is a phytoconstituent found in the methanolic extracts obtained from the roots of Angelica dahurica, which contains anti-inflammatory, anti-bacterial, analgesic, anti-tumor, and vasodilatory activities. QHS possesses potent antagonistic activity against lipopolysaccharide (LPS)-induced inflammation; however, the mechanism of action remains unclear. In this study, we investigated the anti-inflammatory effect of QHS and explored the underlying mechanisms. The QHS was purchased from Jiangsu Yongjian Pharmaceutical Co., Ltd. (Jiangsu, China). We performed MTT assay, real-time PCR, ELISA, and western blotting experiments to assess the anti-inflammatory activity and the possible mechanism of QHS in vitro. Molecular docking was performed to study the binding of QHS and myeloid differentiation protein-2 (MD-2) and elucidate the possible anti-inflammatory mechanism. QHS had no significant effect on cell viability. Moreover, pre-treatment with QHS significantly decreased the release of inflammatory cytokines and mediators including NO, TNF-α, IL-6, and IL-1β. In addition, real-time PCR showed that QHS decreased the mRNA expressions of iNOS, COX-2 TNF-α, IL-6, and IL-1β. Western blotting indicated that QHS could inhibit the expression of the proteins associated with the LPS-TLR4/MD-2-NF-κB signaling pathway. Lastly, molecular docking revealed a possible binding mechanism between QHS and MD-2. QHS exhibited anti-inflammatory activity when combined with MD-2, regulating the LPS-TLR4/MD-2-NF-κB signaling pathway, and inhibiting the release and expression of inflammatory cytokines and mediators. Furthermore, QHS can be used as a potential TLR4 antagonist, which blocks MD-2 binding, for treating inflammatory responses induced by LPS.

Suppressive Effects of Britanin, a Sesquiterpene Compound Isolated from Inulae Flos, on Mast Cell-Mediated Inflammatory Responses

2014 ◽  
Vol 42 (04) ◽  
pp. 935-947 ◽  
Author(s):  
Hyo-Hyun Park ◽  
Sun-Gun Kim ◽  
Young Na Park ◽  
Jiean Lee ◽  
Youn Ju Lee ◽  
...  
Keyword(s):  
Mast Cell ◽  
Inflammatory Cytokines ◽  
Nuclear Translocation ◽  
Inflammatory Responses ◽  
Human Mast Cell ◽  
Ionophore A23187 ◽  
Dependent Manner ◽  
Vitro Assay ◽  
Dose Dependent ◽  
Pro Inflammatory Cytokines

Mast cells are central players in immediate-type hypersensitvity and inflammatory responses. In the present study, the effects of britanin on the passive cutaneous anaphylaxis (PCA) reaction in mice and on the phorbol 12-myristate 13-acetate and calcium ionophore A23187 (PMACI)-induced production of pro-inflammatory cytokines in human mast cell line (HMC-1) were evaluated. The oral administration of britanin (10–20 mg/kg) decreased the mast cell-mediated PCA reaction in IgE-sensitized mice. In the activity and mechanism of britanin in vitro assay, britanin suppressed the gene expression and secretion of pro-inflammatory cytokines in a dose-dependent manner in HMC-1. In addition, britanin attenuated PMACI-induced activation of NF-κB as indicated by the inhibition of the degradation of IκBα, nuclear translocation of NF-κB, NF-κB/DNA binding activity assay, and blocked the phosphorylation of p38 MAP kinase, in a dose-dependent manner. We conclude that britanin may have potential as a treatment for allergic-inflammatory diseases.

MO596HYPERPHOSPHATEMIA INDUCES ENDOTHELIN-1 SYNTHESIS AND INFLAMMATION IN LUNG FIBROBLASTS

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Ana Asenjo-Bueno ◽  
Elena Alcalde-Estevez ◽  
Gemma Olmos ◽  
Diego Rodríguez-Puyol ◽  
Maria Piedad Ruiz-Torres ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Lung Function ◽  
Real Time ◽  
Chronic Diseases ◽  
Inflammatory Cytokines ◽  
Real Time Pcr ◽  
Lung Fibroblasts ◽  
Ros Production ◽  
Tnf Α ◽  
Pro Inflammatory Cytokines

Abstract Background and Aims Hyperphosphatemia is an aging-related condition associated to chronic diseases such as chronic kidney disease (CKD). In both cases, aging and CKD, it has been described a decline lung function, however, relationship between high serum levels of phosphate and lung damage has not been described yet. The aim of this work was to evaluate if phosphate could induce inflammation in lung, studying the mechanisms implied. Method In vitro studies were performed on a cell line from human lung fibroblasts (Wi-38) which were treated with a phosphate donor termed β-glycerophosphate (BGP, 10 mM) and also with endothelin 1 (ET-1, 10 nM) at different times. To assess inflammation, the expression of several cytokines such as TNF-α,IL-1β, IL-6 and MCP-1 were measured by real time PCR. mRNA expressions of prepro-ET-1 and endothelin-converting enzyme-1 (ECE-1) were also analyzed by real time PCR. Reactive oxygen species (ROS) production was evaluated by confocal microscopy in live cells using the fluorogenic probe CellROX as oxidative stress reagent. Results Treatment with BGP induced a significant rise of the pro-inflammatory cytokines expression, TNF-α, IL-1β, IL-6 and MCP-1, on lung fibroblasts. Moreover, BGP was able to regulate ET-1 system, as we found a significant increase of mRNA expressions not only of prepro-ET-1 but also of ECE-1, reaching a peak around 2 and 6 hours, respectively. Later, it was checked whether ET-1 could induce inflammation itself in lung fibroblasts. Cells incubated with ET-1 show similar results as BGP, increasing expressions of all cytokines, TNF-α, IL-1β, IL-6 and MCP-1.ET-1 response was earlier than BGP, around at 2 hours with ET-1 instead of at 8 hours with BGP. In order to elucidate a possible mechanism, ROS production was assessed after BGP treatment. BGP induced ROS production at 15 min in lung fibroblasts. Conclusion BGP induces the synthesis of pro-inflammatory cytokines as well as the system of synthesis of ET-1, besides to rise ROS production.ET-1 itself also increases pro-inflammatory cytokines expression. ET-1 could contribute to the inflammation observed in lung fibroblast after BGP treatment. We propose oxidative stress as a potential mechanism implied, as it is well known that ROS can mediate in inflammation and in the ET system. However, more studies are necessary to confirm this role. All in all, these results relate hyperphosphatemia with a higher inflammation in lung fibroblasts which could decline lung function in chronic diseases associated to aging as CKD.

scholarly journals Lactobacillus rhamnosus GG attenuates interferon-γ and tumour necrosis factor-α-induced barrier dysfunction and pro-inflammatory signalling

Microbiology ◽  
2010 ◽  
Vol 156 (11) ◽  
pp. 3288-3297 ◽  
Author(s):  
Kevin A. Donato ◽  
Mélanie G. Gareau ◽  
Yu Jing Jenny Wang ◽  
Philip M. Sherman
Keyword(s):  
Epithelial Cells ◽  
Inflammatory Cytokines ◽  
Time Course ◽  
Nuclear Translocation ◽  
Inflammatory Responses ◽  
Cell Signalling ◽  
Lactobacillus Rhamnosus ◽  
Basal Medium ◽  
Barrier Dysfunction ◽  
Pro Inflammatory Cytokines

The intestinal epithelium forms a protective barrier against luminal contents and the external environment, mediated via intercellular tight junctions (TJs). The TJ can be disrupted via cell signalling induced by either enteric pathogens or pro-inflammatory cytokines, thereby contributing to various intestinal disorders ranging from acute infectious diarrhoea to chronic inflammatory bowel diseases. Probiotics, such as Lactobacillus rhamnosus GG (LGG), are reported to confer beneficial effects on epithelial cells, including antagonizing infections and reducing overt pro-inflammatory responses, but the underlying mechanisms of these observed effects require further characterization. We hypothesized that probiotics preserve barrier function by interfering with pro-inflammatory cytokine signalling. Caco-2bbe cells were seeded into Transwells to attain polarized monolayers with intercellular TJs. Monolayers were inoculated apically with the probiotic LGG 3 h prior to the addition of IFN-γ (100 ng ml−1) to the basolateral medium overnight. The monolayers were then placed in fresh basal medium±TNF-α (10 ng ml−1) and transepithelial electrical resistance (TER) measurements were taken over the time-course of TNF-α stimulation. To complement the TER findings, cells were processed for zona occludens-1 (ZO-1) immunofluorescence staining. As a measure of TNF-α downstream signalling, cells were immunofluorescently stained for NF-κB p65 subunit and CXCL-8 mRNA was quantified by qRT-PCR. Basal cell culture medium was collected after overnight TNF-α stimulation to measure secreted chemokines, including CXCL-8 (interleukin-8) and CCL-11 (eotaxin). Following LGG inoculation, IFN-γ priming and 24 h TNF-α stimulation, epithelial cells maintained TER and ZO-1 distribution. LGG diminished the nuclear translocation of p65, demonstrated by both immunofluorescence and CXCL-8 mRNA expression. CXCL-8 and CCL-11 protein levels were decreased in LGG-inoculated, cytokine-challenged cells. These findings indicate that LGG alleviates the effects of pro-inflammatory cytokines on epithelial barrier integrity and inflammation, mediated, at least in part, through inhibition of NF-κB signalling.

MiR-144-3p Inhibits BMSC Proliferation and Osteogenic Differentiation Via Targeting FZD4 in Steroid-Associated Osteonecrosis

2020 ◽  
Vol 25 (45) ◽  
pp. 4806-4812 ◽  
Author(s):  
Zhibo Sun ◽  
Fei Wu ◽  
Yue Yang ◽  
Feng Liu ◽  
Fengbo Mo ◽  
...  
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Nuclear Translocation ◽  
Bone Diseases ◽  
Luciferase Reporter ◽  
Reporter Assay ◽  
Alizarin Red ◽  
Over Expression ◽  
Negative Effect ◽  
Proliferation Ability

Background: MicroRNAs have recently been recognized to be engaged in the development of bone diseases. Objective: This study was performed to elucidate the effects of miR-144-3p on proliferation and osteogenesis of mesenchymal stem cells (MSCs) from the patients with steroid-associated osteonecrosis (ONFH) and its related mechanism. Method: The expression level of miR-144-3p in the MSCs from the proximal femur of the patients was examined by Real-time PCR. The cell proliferation ability was assayed by MTT. The differentiation ability of MSCs was assayed by Alizarin Red S (ARS) staining. The interaction between miR-144-3p and frizzled4 (FZD4) was investigated by Real-time PCR, western blot and luciferase reporter assay. Results: ONFH samples had the obviously high expression of miR-144-3p compared to the control. MiR-144-3p had a negative effect on the proliferation and osteogenesis of MSCs. Via targeting FZD4, miR-144-3p decreased β-catenin nuclear translocation, the transcription of RUNX2 and COL1A1. Over-expression of FZD4 partially reversed miR-144-3p-induced decrease in the proliferation and osteogenesis of MSCs. Conclusion: MiR-144-3p might play an important role in the development of ONFH and might be used as a novel class of therapeutic targets for this disease.

scholarly journals Punicalagin Prevents Inflammation in LPS-Induced RAW264.7 Macrophages by Inhibiting FoxO3a/Autophagy Signaling Pathway

Nutrients ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2794 ◽  
Author(s):  
Cao ◽  
Chen ◽  
Ren ◽  
Zhang ◽  
Tan ◽  
...  
Keyword(s):  
Western Blot ◽  
Signaling Pathway ◽  
Inflammatory Cytokines ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Inflammatory Responses ◽  
Raw264.7 Macrophages ◽  
Tnf Α ◽  
Autophagy Inhibition ◽  
Pro Inflammatory Cytokines

Punicalagin, a hydrolysable tannin of pomegranate juice, exhibits multiple biological effects, including inhibiting production of pro-inflammatory cytokines in macrophages. Autophagy, an intracellular self-digestion process, has been recently shown to regulate inflammatory responses. In this study, we investigated the anti-inflammatory potential of punicalagin in lipopolysaccharide (LPS) induced RAW264.7 macrophages and uncovered the underlying mechanisms. Punicalagin significantly attenuated, in a concentration-dependent manner, LPS-induced release of NO and decreased pro-inflammatory cytokines TNF-α and IL-6 release at the highest concentration. We found that punicalagin inhibited NF-κB and MAPK activation in LPS-induced RAW264.7 macrophages. Western blot analysis revealed that punicalagin pre-treatment enhanced LC3II, p62 expression, and decreased Beclin1 expression in LPS-induced macrophages. MDC assays were used to determine the autophagic process and the results worked in concert with Western blot analysis. In addition, our observations indicated that LPS-induced releases of NO, TNF-α, and IL-6 were attenuated by treatment with autophagy inhibitor chloroquine, suggesting that autophagy inhibition participated in anti-inflammatory effect. We also found that punicalagin downregulated FoxO3a expression, resulting in autophagy inhibition. Overall these results suggested that punicalagin played an important role in the attenuation of LPS-induced inflammatory responses in RAW264.7 macrophages and that the mechanisms involved downregulation of the FoxO3a/autophagy signaling pathway.

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