scholarly journals Extracellular HMGB1 Induced Glomerular Endothelial Cell Injury via TLR4/MyD88 Signaling Pathway in Lupus Nephritis

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Tian Yu ◽  
Feng Xiaojuan ◽  
Liu Jinxi ◽  
Miao Xinyan ◽  
Xu Jie ◽  
...  

Previously, our study showed that HMGB1 was significantly elevated in the blood and located in the glomerular endothelium in LN patients. But whether extracellular HMGB1 is involved in the injury of glomerular endothelial cells (GECs) in LN still needs further investigation. Firstly, we detected the levels of SDC-1, VCAM-1, and proteinuria in LN patients and MRL/lpr mice and analyzed their correlations. Then, HMGB1 and TLR4/MyD88 were inhibited to observe the shedding of glycocalyx and injury of GECs in vivo and in vitro. Our results showed that HRGEC injury and SDC-1 shedding played an important role in the increase of permeability and proteinuria formation in LN. Additionally, inhibition of extracellular HMGB1 and/or downstream TLR4/MyD88/NF-κB/p65 signaling pathway also alleviated GEC monolayer permeability, reduced the shedding of the glomerular endothelial glycocalyx, improved the intercellular tight junction and cytoskeletal arrangement, and downregulated the NO level and VCAM-1 expression. These results suggested that extracellular HMGB1 might involve in GEC injury by activating the TLR4/MyD88 signaling pathway in LN, which provided novel insights and potential therapeutic target for the treatment of lupus nephritis.

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Zhenjian Xu ◽  
Junzhe Chen ◽  
Anping Xu

Abstract Background and Aims Our previous study found a new regulatory T cell subpopulation, CD4+CD126lowFoxp3+ regulatory T cells (CD4+CD126lowFoxp3+ Treg). This cell can maintain a stable immune regulatory function in the inflammatory state. Through in vivo and in vitro experiments, we have confirmed that CD4+CD126lowFoxp3+ Treg has an immunotherapeutic effect on T cell-mediated mouse models of autoimmune diseases such as colitis and collagen-induced arthritis (CIA). Further experimental studies showed that CD4+CD126lowFoxp3+ Treg could reduce the kidney injury caused by autoantibodies and prolong the survival time of lupus mice. However, the mechanism of CD4+CD126lowFoxp3+ Treg immunotherapy in lupus nephritis is not clear. The purpose of this study was to explore the mechanism of CD4+CD126lowFoxp3+ Treg immunotherapy in mice with lupus nephritis. Method In vitro experiments CD4+CD126lowFoxp3+ Treg or CD4+CD126lowFoxp3+ Treg pretreated with PD-1 inhibitor were co-cultured with T or B lymphocytes of lupus mice under different in vitro culture condition. The expression levels of Akt and mTOR of Treg in each group were measured under immunoinflammatory conditions. To observe the effects and differences of Treg groups on the activation, proliferation and differentiation of T or B cells and other immunomodulatory effects. In vivo experiments CD4+CD126lowFoxp3+ Treg (2 × 106/mouse) and CD4+CD126lowFoxp3+ Treg (2 × 106/mouse) pretreated with PD-1 inhibitor and PBS were injected into NZM2328 lupus mice, respectively. After cell injection, urine protein was measured weekly. Autoantibody expression in lupus mice was measured every two weeks. The effects of Treg on the proliferation and differentiation of T/B cells in lupus mice were observed. The therapeutic effects of Treg on lupus mice were observed. Results Compared with CD4+CD126lowFoxp3+ Treg, the expression of Akt and mTOR increases in PD-1 inhibitors pretreatment cells. The activation, proliferation and differentiation functions of T or B lymphocytes of lupus mice were significantly weakened by immunosuppression of PD-1 inhibitors pretreated Treg in vitro, indicating that CD4+CD126lowFoxp3+ Treg may inhibit Akt-mTOR signaling pathway through PD-1 in in vitro. Compared with CD4+CD126lowFoxp3+ Treg, the activation, proliferation and differentiation functions of T or B lymphocytes of lupus mice were significantly weakened by immunosuppression of PD-1 inhibitors pretreated Treg in vivo. And its therapeutic effect on lupus mice was ineffective, indicating that CD4+CD126lowFoxp3+ Treg may inhibit Akt-MTOR signaling pathway through PD-1 in vivo. Conclusion CD4+CD126lowFoxp3+ Treg may inhibit the Akt-mTOR signaling pathway by expressing PD-1, and maintain stable immunomodulatory function in the inflammatory state, thus producing immunotherapeutic effect on lupus nephritis mice.


2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Zhiqin Liu ◽  
Leixi Xue ◽  
Zhichun Liu ◽  
Jun Huang ◽  
Jian Wen ◽  
...  

This study aim was to explore the effects of tumor necrosis factor-like weak inducer of apoptosis (TWEAK) in lupus nephritis and its potential underlying mechanisms. MRL/lpr mice were used forin vivoexperiments and human proximal tubular cells (HK2 cells) were used forin vitroexperiments. Results showed that MRL/lpr mice treated with vehicle solution or LV-Control shRNA displayed significant proteinuria and severe renal histopathological changes. LV-TWEAK-shRNA treatment reversed these changes and decreased renal expressions of TWEAK, TGF-β1, p-p38 MAPK, p-Smad2, COL-1, andα-SMA proteins.In vitro, hTWEAK treatment upregulated the expressions of TGF-β1, p-p38 MAPK, p-SMAD2,α-SMA, and COL-1 proteins in HK2 cells and downregulated the expressions of E-cadherin protein, which were reversed by cotreatment with anti-TWEAK mAb or SB431542 treatment. These findings suggest that TWEAK may contribute to chronic renal changes and renal fibrosis by activating TGF-β1 signaling pathway, and phosphorylation of Smad2 and p38 MAPK proteins was also involved in this signaling pathway.


2021 ◽  
Vol 12 ◽  
Author(s):  
Lintao Wang ◽  
Suya Zhang ◽  
Jibo Han ◽  
Xiaoyan Nie ◽  
Yajun Qi ◽  
...  

Cardiovascular complications are a well-documented limitation of conventional cancer chemotherapy. As a notable side effect of cisplatin, cardiotoxicity represents a major obstacle to the treatment of cancer. Recently, it has been reported that cyclic GMP-AMP synthase (cGAS) stimulator of interferon genes (STING) signaling pathway was associated with the occurrence and development of cardiovascular diseases. However, the effect of STING on cardiac damage caused by cisplatin remains unclear. In this study, cisplatin was shown to activate the cGAS-STING signaling pathway, and deficiency of STING attenuated cisplatin-induced cardiotoxicity in vivo and in vitro. Mechanistically, the STING-TNF-α-AP-1 axis contributed to cisplatin-induced cardiotoxicity by triggering cardiomyocyte apoptosis. In conclusion, our results indicated that STING might be a critical regulator of cisplatin-induced cardiotoxicity and be considered as a potential therapeutic target for preventing the progression of chemotherapy-associated cardiovascular complications.


2021 ◽  
Author(s):  
lianxiang luo ◽  
Xiaoling Li ◽  
Riming Huang ◽  
Hui Luo

Abstract BackgroundAcute lung injury (ALI) is a leading cause of morbidity and mortality in respiratory disease. Astaxanthin, a natural antioxidant xanthophyll carotenoid, has been shown to possess anti-inflammatory activity. However, poor evidence has been reported that whether it has protective effects against ALI.Methods A network pharmacology analysis was carried out combining the construction of the GeneCards database and the Pharmmapper database, The potential active compounds and targets were predicted by compound-target prediction, protein-protein interaction analysis, GO and KEGG pathway analysis. Then, the anti-inflammation effect of astaxanthin was investigated in LPS-induced RAW264.7 cells in vitro and LPS-induced ALI mice in vivo.ResultsThe results screened by GO and KEGG enrichment analysis suggested that astaxanthin had extensive associations with 25 known therapeutic targets of ALI. These target genes were further found to be associated with pathways involved in inflammatory pathways in ALI, such as the Toll-like receptor signal pathway, TNF signal pathway, Hif signal pathway, and NF-Kappa B signal pathway. Pre-treatment with astaxanthin inhibited the TLR4/MyD88 signaling pathway and attenuated LPS-increased inflammatory factors in vitro. Furthermore, the administration of astaxanthin significantly protected lung injury in vivo. Subsequently, we validated astaxanthin binds to the TLR4 pocket using molecular docking. ConclusionTaken together, astaxanthin exerts impressively protective effects on LPS-induced ALI in vitro and in vivo via suppressing the TLR4/MyD88 signaling pathway.


Author(s):  
Suwei Zhu ◽  
Shaoshuai Hou ◽  
Yao Lu ◽  
Wei Sheng ◽  
Zhengguo Cui ◽  
...  

Diabetic kidney disease (DKD) has become the leading cause of end-stage renal disease but the efficacy of current treatment remains unsatisfactory. The pathogenesis of DKD needs a more in-depth research. Ubiquitin specific proteases 36 (USP36), a member of deubiquitinating enzymes family, has aroused wide concerns for its role in deubiquitinating and stabilizing target proteins. Nevertheless, the role of USP36 in diabetes has never been reported yet. Herein, we identified an increased expression of USP36 both in vitro and in vivo in diabetic renal tubular epithelial cells (TECs), and its overexpression is related to the enhanced epithelial-to-mesenchymal transition (EMT). Further investigation into the mechanisms proved that USP36 could directly bind to and mediate the deubiquitination of dedicator of cytokinesis 4 (DOCK4), a guanine nucleotide exchange factor (GEF) that could activate Wnt/β-catenin signaling pathway and induce EMT. Our study revealed a new mechanism that USP36 participates in the pathogenesis of DKD, and provided potential intervening targets accordingly.


2021 ◽  
pp. 1-11
Author(s):  
Yupeng Liu ◽  
Hui Wu ◽  
Fan Zhang ◽  
Jun Yang ◽  
Jingchun He

Resveratrol is a non-flavonoid polyphenol compound that exists in many plants, and is considered an antitoxin. This study explores the effects from the regulation of miR-455-5p by resveratrol on cisplatin-induced ototoxicity via the PTEN–PI3K–AKT signaling pathway. For this, House Ear Institute–Organ of Corti 1 (HEI-OC1) cells were transfected with miR-455-5p inhibitor and treated with cisplatin and resveratrol, then cell proliferation, apoptosis, and oxidative stress were evaluated. A mouse model of hearing loss was established, and these mice were treated with cisplatin, resveratrol, or cisplatin combined with resveratrol, by intraperitoneal injection. The auditory brainstem response (ABR) threshold was measured, and hair cells were examined using immunofluorescence staining. The expression levels of miR-455-5p, PTEN, and PI3K/Akt proteins were examined. The results from our in-vitro experiments indicate that resveratrol promoted viability and reduced apoptosis and oxidative stress in cisplatin-induced HEI-OC1 cells. Resveratrol upregulated miR-455-5p, downregulated PTEN, and activated the PI3K–Akt axis. These effects of resveratrol were reversed by knock-down of miR-455-5p. The results from our in-vivo experiments indicate that resveratrol protected hearing and inhibited the hair-cell injury caused by cisplatin ototoxicity. Resveratrol also upregulated miR-455-5p, downregulated PTEN, and activated the PTEN–PI3K–Akt axis in cochlear tissues from cisplatin-treated mice. These results indicate that resveratrol upregulates miR-455-5p to target PTEN and activate the PI3K–Akt signaling pathway to counteract cisplatin ototoxicity.


2021 ◽  
Vol 12 (5) ◽  
Author(s):  
Ben Liu ◽  
Meng Zhou ◽  
Xiangchun Li ◽  
Xining Zhang ◽  
Qinghua Wang ◽  
...  

AbstractThere is a male preponderance in gastric cancer (GC), which suggests a role of androgen and androgen receptor (AR). However, the mechanism of AR signaling in GC especially in female patients remains obscure. We sought to identify the AR signaling pathway that might be related to prognosis and examine the potential clinical utility of the AR antagonist for treatment. Deep learning and gene set enrichment analysis was used to identify potential critical factors associated with gender bias in GC (n = 1390). Gene expression profile analysis was performed to screen differentially expressed genes associated with AR expression in the Tianjin discovery set (n = 90) and TCGA validation set (n = 341). Predictors of survival were identified via lasso regression analyses and validated in the expanded Tianjin cohort (n = 373). In vitro and in vivo experiments were established to determine the drug effect. The GC gender bias was attributable to sex chromosome abnormalities and AR signaling dysregulation. The candidates for AR-related gene sets were screened, and AR combined with miR-125b was associated with poor prognosis, particularly among female patients. AR was confirmed to directly regulate miR-125b expression. AR-miR-125b signaling pathway inhibited apoptosis and promoted proliferation. AR antagonist, bicalutamide, exerted anti-tumor activities and induced apoptosis both in vitro and in vivo, using GC cell lines and female patient-derived xenograft (PDX) model. We have shed light on gender differences by revealing a hormone-regulated oncogenic signaling pathway in GC. Our preclinical studies suggest that AR is a potential therapeutic target for this deadly cancer type, especially in female patients.


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