scholarly journals Depletion of Toll-Like Receptor-9 Attenuates Renal Tubulointerstitial Fibrosis After Ischemia-Reperfusion Injury

2021 ◽  
Vol 9 ◽  
Author(s):  
Haofeng Zheng ◽  
Yannan Zhang ◽  
Lei Li ◽  
Rui Zhang ◽  
Zihuan Luo ◽  
...  
Keyword(s):  
Ischemia Reperfusion Injury ◽  
Smooth Muscle Actin ◽  
Ischemia Reperfusion ◽  
Critical Role ◽  
Dependent Manner ◽  
Toll Like Receptor ◽  
Mesenchymal Transition ◽  
Renal Tubulointerstitial Fibrosis ◽  
Collagen Iii

Toll-like receptor-9 (TLR-9) is a potent proinflammatory receptor that mediates renal injury. However, the reported effects of TLR-9 are contradictory. Here, using a traditional mouse AKI→CKD transition model, the roles of TLR-9 during the transition from acute kidney injury (AKI) to chronic kidney disease (CKD) were further explored. Using a TLR-9–/– mouse, the effects and mechanisms of TLR-9 were investigated. Loss of TLR-9 elicited no obvious effects as regards renal function or histology during AKI in the early phases (24–48 h), while TLR-9 KO attenuated renal fibrosis (as shown using fibronectin and collagen III) and epithelial-to-mesenchymal transition (EMT) [E-cadherin (E-Cad) and α-smooth muscle actin (α-SMA)] on the long-term after AKI through the inhibition of macrophages infiltration, especially M2 macrophages. The roles of TLR-9 on macrophages were also explored using Raw264.7 macrophage cell line, and results indicated that the inhibition of TLR-9 on Raw 264.7 macrophages decreased the induction of M2 type macrophage in a dose-dependent manner. The roles of TLR-9 on renal tubular epithelial (RTE) cells were also explored. Conversely, TLR-9 depletion did not contribute to the improvement of fibrosis and EMT in vitro. Therefore, TLR-9 plays a critical role in the AKI→CKD transition. Attenuation of CKD post-AKI in the TLR-9 KO group mainly relies on the effects of TLR-9 on macrophages. These results also suggest that TLR-9 could be a therapeutic target for CKD.

scholarly journals Hydroxychloroquine Inhibits Macrophage Activation and Attenuates Renal Fibrosis After Ischemia-Reperfusion Injury

2021 ◽  
Vol 12 ◽  
Author(s):  
Haofeng Zheng ◽  
Yannan Zhang ◽  
Jiannan He ◽  
Zhe Yang ◽  
Rui Zhang ◽  
...  
Keyword(s):  
Reperfusion Injury ◽  
Renal Fibrosis ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Tubulointerstitial Fibrosis ◽  
Health Concern ◽  
Dependent Manner ◽  
Renal Tubulointerstitial Fibrosis

Chronic kidney disease (CKD), which is associated with high morbidity, remains a worldwide health concern, while effective therapies remain limited. Hydroxychloroquine (HCQ), which mainly targets toll-like receptor-7 (TLR-7) and TLR-9, is associated with a lower risk of incident CKD. Taking into account that TLR-9 is involved in the development of renal fibrosis and serves as a potential therapy target for CKD, we investigated whether HCQ could attenuate CKD via TLR-9 signal pathway. The effects of HCQ on renal tubulointerstitial fibrosis were further explored using a mouse model of renal tubulointerstitial fibrosis after ischemia/reperfusion injury. Bone marrow-derived macrophages were isolated to explore the effects of HCQ in vitro. Judicious use of HCQ efficiently inhibited the activation of macrophages and MAPK signaling pathways, thereby attenuating renal fibrosis in vivo. In an in vitro model, results showed that HCQ promoted apoptosis of macrophages and inhibited activation of macrophages, especially M2 macrophages, in a dose-dependent manner. Because TLR-7 is not involved in the development of CKD post-injury, a TLR-9 knockout mouse was used to explore the mechanisms of HCQ. The effects of HCQ on renal fibrosis and macrophages decreased after depletion of TLR-9 in vivo and in vitro. Taken together, this study indicated that proper use of HCQ could be a new strategy for anti-fibrotic therapy and that TLR-9 could be a potential therapeutic target for CKD following acute kidney injury.

scholarly journals NMDA receptor-mediated CaMKII/ERK activation contributes to renal fibrosis

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Jingyi Zhou ◽  
Shuaihui Liu ◽  
Luying Guo ◽  
Rending Wang ◽  
Jianghua Chen ◽  
...  
Keyword(s):  
Reperfusion Injury ◽  
Renal Fibrosis ◽  
Epithelial To Mesenchymal Transition ◽  
Ischemia Reperfusion Injury ◽  
Smooth Muscle Actin ◽  
Ischemia Reperfusion ◽  
Mesenchymal Transition ◽  
Erk Activation

Abstract Background This study aimed to understand the mechanistic role of N-methyl-D-aspartate receptor (NMDAR) in acute fibrogenesis using models of in vivo ureter obstruction and in vitro TGF-β administration. Methods Acute renal fibrosis (RF) was induced in mice by unilateral ureteral obstruction (UUO). Histological changes were observed using Masson’s trichrome staining. The expression levels of NR1, which is the functional subunit of NMDAR, and fibrotic and epithelial-to-mesenchymal transition markers were measured by immunohistochemical and Western blot analysis. HK-2 cells were incubated with TGF-β, and NMDAR antagonist MK-801 and Ca2+/calmodulin-dependent protein kinase II (CaMKII) antagonist KN-93 were administered for pathway determination. Chronic RF was introduced by sublethal ischemia–reperfusion injury in mice, and NMDAR inhibitor dextromethorphan hydrobromide (DXM) was administered orally. Results The expression of NR1 was upregulated in obstructed kidneys, while NR1 knockdown significantly reduced both interstitial volume expansion and the changes in the expression of α-smooth muscle actin, S100A4, fibronectin, COL1A1, Snail, and E-cadherin in acute RF. TGF-β1 treatment increased the elongation phenotype of HK-2 cells and the expression of membrane-located NR1 and phosphorylated CaMKII and extracellular signal–regulated kinase (ERK). MK801 and KN93 reduced CaMKII and ERK phosphorylation levels, while MK801, but not KN93, reduced the membrane NR1 signal. The levels of phosphorylated CaMKII and ERK also increased in kidneys with obstruction but were decreased by NR1 knockdown. The 4-week administration of DXM preserved renal cortex volume in kidneys with moderate ischemic–reperfusion injury. Conclusions NMDAR participates in both acute and chronic renal fibrogenesis potentially via CaMKII-induced ERK activation.

scholarly journals Role of Stat3 Signaling in Control of EMT of Tubular Epithelial Cells During Renal Fibrosis

2017 ◽  
Vol 42 (6) ◽  
pp. 2552-2558 ◽  
Author(s):  
Jingsong Liu ◽  
Ying Zhong ◽  
Guoyong Liu ◽  
Xiaobai Zhang ◽  
Bofei Xiao ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Renal Injury ◽  
Renal Fibrosis ◽  
Critical Role ◽  
Dependent Manner ◽  
Tubular Epithelial Cells ◽  
Mesenchymal Transition ◽  
Stat3 Signaling ◽  
Phosphorylated Stat3

Background/Aims: Transforming growth factor β 1 (TGFβ1) plays a critical role in the epithelial-to-mesenchymal transition (EMT) of renal tubular epithelial cells (TECs) during renal injury, a major cause of acute renal failure, renal fibrosis and obstructive nephropathy. However, the underlying molecular mechanisms remain ill-defined. Here, we addressed this question. Methods: Expression of TGFβ1, Snail, and phosphorylated Stat3 was examined by immunohistochemistry in the kidney after induction of unilateral ureteral obstruction (UUO) in mice. In vitro, primary TECs were purified by flow cytometry, and then challenged with TGFβ1 with/without presence of specific inhibitors for phosphorylation of SMAD3 or Stat3. Protein levels were determined by Western blotting. Results: We detected significant increases in Snail and phosphorylated Stat3, an activated form for Stat3, in the kidney after induction of UUO in mice. In vitro, TGFβ1-challenged primary TECs upregulated Snail, in a SMAD3/Stat3 dependent manner. Conclusion: Our study sheds light on the mechanism underlying the EMT of TECs after renal injury, and suggests Stat3 signaling as a promising innovative therapeutic target for prevention of renal fibrosis.

scholarly journals Safflower Yellow B Protects Brain against Cerebral Ischemia Reperfusion Injury through AMPK/NF-kB Pathway

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Shibin Du ◽  
Youliang Deng ◽  
Hongjie Yuan ◽  
Yanyan Sun
Keyword(s):  
Brain Injury ◽  
Cerebral Ischemia ◽  
Pc12 Cells ◽  
Inflammatory Cytokines ◽  
Nuclear Translocation ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Dependent Manner ◽  
Secondary Damage

Inflammation had showed its important role in the pathogenesis of cerebral ischemia and secondary damage. Safflower yellow B (SYB) had neuroprotective effects against oxidative stress-induced brain injuries, but the mechanisms were still largely unknown to us. In this study, we tried to investigate the anti-inflammation effects of SYB and the possible roles of AMPK/NF-κB signaling pathway on these protective effects. In vivo, brain ischemia/reperfusion (I/R) was induced by transient middle cerebral artery occlusion for 2 h and reperfusion for 20 h. Neurofunctional evaluation, infarction area, and brain water contents were measured. Brain injury markers and inflammatory cytokines levels were measured by ELISA kits. In vitro, cell viability, apoptosis, and LDH leakage were measured after I/R in PC12 cells. The expression and phosphorylation levels of AMPK, NF-κB p65, and P-IκB-α in cytoplasm and nuclear were measured by Western blotting. SiRNA experiment was performed to certify the role of AMPK. The results showed SYB reduced infarct size, improved neurological outcomes, and inhibited brain injury after I/R. In vitro test, SYB treatment alleviated PC12 cells injury and apoptosis and inhibited the inflammatory cytokines (IL-1, IL-6, TNF-α, and COX-2) in a dose-dependent manner. SYB treatment induced AMPK phosphorylation and inhibited NF-κB p65 nuclear translocation both in brain and in PC12 cells. Further studies also showed that the inhibition of NF-κB activity of SYB was through AMPK. In conclusion, SYB protected brain I/R injury through reducing expression of inflammatory cytokines and this effect might be partly due to the inhibition of NF-κB mediated by AMPK.

scholarly journals Identification of Tisp40 as an Essential Regulator of Renal Tubulointerstitial Fibrosis via TGF-β/Smads Pathway

2017 ◽  
Vol 42 (2) ◽  
pp. 697-712 ◽  
Author(s):  
Cheng-cheng Xiao ◽  
Jie Zhang ◽  
Peng-cheng Luo ◽  
Cong Qin ◽  
Yang Du ◽  
...  
Keyword(s):  
Western Blot ◽  
Blot Analysis ◽  
Western Blot Analysis ◽  
Renal Fibrosis ◽  
Molecular Mechanisms ◽  
Ischemia Reperfusion ◽  
Critical Role ◽  
Tubulointerstitial Fibrosis ◽  
Mesenchymal Transition ◽  
Renal Tubulointerstitial Fibrosis

Background: Tisp40, a transcription factor of the CREB/CREM family, is involved in cell proliferation, differentiation and other biological functions, but its role in renal tubulointerstitial fibrosis is unknown. Methods: In our study, we investigated the effects of Tisp40 on extracellular matrix (ECM) accumulation, epithelial-mesenchymal transition (EMT) and the underlying molecular mechanisms in transforming growth factor-β (TGF-β)-stimulated TCMK-1 cells by quantitative real-time polymerase chain reaction (qPCR), Western blot analysis and immunofluorescence in vitro, and further explored the role of Tisp40 on renal fibrosis induced by ischemia-reperfusion (I/R) by qPCR, Western blot analysis, hydroxyproline analysis, Masson trichrome staining and immunohistochemistry staining in vivo. Results: The data showed that Tisp40 was upregulated in a model of renal fibrosis induced by I/R injury (IRI). Upon IRI, Tisp40-deficient mice showed attenuated renal fibrosis compared with wild-type mice. Furthermore, the expression of α-smooth muscle actin, E-cadherin, fibronectin, and collagen I was suppressed. Tisp40 overexpression aggravated ECM accumulation and EMT in the TGF-β-stimulated TCMK-1 cell line, whereas the opposite occurred in cells treated with small interfering RNA (siRNA) targeting Tisp40. Importantly, it is changes in the Smad pathway that attenuate renal fibrosis. Conclusion: These findings suggest that Tisp40 plays a critical role in the TGF-β/ Smads pathway involved in this process. Hence, Tisp40 could be a useful therapeutic target in the fight against renal tubulointerstitial fibrosis.

scholarly journals Toll-like receptor 2 mediates mesenchymal stem cell-associated myocardial recovery and VEGF production following acute ischemia-reperfusion injury

2010 ◽  
Vol 298 (5) ◽  
pp. H1529-H1536 ◽  
Author(s):  
Aaron M. Abarbanell ◽  
Yue Wang ◽  
Jeremy L. Herrmann ◽  
Brent R. Weil ◽  
Jeffrey A. Poynter ◽  
...  
Keyword(s):  
Reperfusion Injury ◽  
Ischemia Reperfusion Injury ◽  
Myocardial Dysfunction ◽  
Ischemia Reperfusion ◽  
Left Ventricular ◽  
Toll Like Receptor ◽  
Myocardial Recovery ◽  
Paracrine Factors ◽  
Toll Like Receptor 2

Toll-like receptor 2 (TLR2), a key component of the innate immune system, is linked to inflammation and myocardial dysfunction after ischemia-reperfusion injury (I/R). Treatment of the heart with mesenchymal stem cells (MSCs) is known to improve myocardial recovery after I/R in part by paracrine factors such as VEGF. However, it is unknown whether TLR2 activation on the MSCs affects MSC-mediated myocardial recovery and VEGF production. We hypothesized that the knockout of TLR2 on the MSCs (TLR2KO MSCs) would 1) improve MSC-mediated myocardial recovery and 2) increase myocardial and MSC VEGF release. With the isolated heart perfusion system, Sprague-Dawley rat hearts were subjected to I/R and received one of three intracoronary treatments: vehicle, male wild-type MSCs (MWT MSCs), or TL2KO MSCs. All treatments were performed immediately before ischemia, and heart function was measured continuously. Postreperfusion, heart homogenates were analyzed for myocardial VEGF production. Contrary to our hypothesis, only MWT MSC treatment significantly improved the recovery of left ventricular developed pressure and the maximal positive and negative values of the first derivative of pressure. In addition, VEGF production was greatest in hearts treated with MWT MSCs. To investigate MSC production of VEGF, MSCs were activated with TNF in vitro and the supernatants collected for ELISA. In vitro basal levels of MSC VEGF production were similar. However, with TNF activation, MWT MSCs produced significantly more VEGF, whereas activated TLR2KO MSC production of VEGF was unchanged. Finally, we observed that MWT MSCs proliferated more rapidly than TLR2KO MSCs. These data indicate that TLR2 may be essential to MSC-mediated myocardial recovery and VEGF production.

scholarly journals Neuroprotective effect of a new free radical scavenger HL-008 against ischemia-reperfusion injury

2020 ◽  
Author(s):  
Yahong Liu ◽  
Ying Cheng ◽  
Wei Zhang ◽  
Hongqi Tian
Keyword(s):  
Oxidative Stress ◽  
Reperfusion Injury ◽  
Brain Tissue ◽  
Cell Activation ◽  
Ischemia Reperfusion Injury ◽  
Neuroprotective Effect ◽  
Ischemia Reperfusion ◽  
Critical Role ◽  
Radical Scavenger

Abstract Oxidative stress plays a critical role in cerebral ischemia-reperfusion injury. We previously developed a powerful antioxidant, HL-008, and this study aimed to investigate the neuroprotective function of HL-008. The in vitro and in vivo efficacy of HL-008 was evaluated using a PC-12 cell oxidative stress model induced by hydrogen peroxide and a rat model of middle cerebral artery occlusion, respectively. The MTT assay was used to analyze cell viability. TTC staining, HE staining, immunofluorescence, western blot, and proteomics were used to evaluate the infarction volume, brain tissue morphology, apoptosis, inflammation, and related pathways. Indicators related to oxidative levels were mainly detected using commercial kits. HL-008 significantly reduced the cerebral infarction area induced by ischemia-reperfusion, improved the neurological score, alleviated oxidative stress and inflammation in the brain tissue, reduced glial cell activation, inhibited brain tissue apoptosis by influencing multiple signaling pathways, and had a neuroprotective effect. If HL-008 is successfully developed, it can significantly improve the quality of life of stroke patients.

scholarly journals Histidine–Tryptophan-–Ketoglutarate Solution as a Neuroprotective Against Ischemia/Reperfusion Injury

2018 ◽  
Author(s):  
Jiun Hsu ◽  
Chih-Hsien Wang ◽  
Shu-Chien Huang ◽  
Yung-Wei Chen ◽  
Shengpin Yu ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
In Vitro Study ◽  
Dependent Manner ◽  
Sterile Saline ◽  
Nadph Oxidase 4 ◽  
H2o2 Level

Ischemic neuron loss contributes to brain dysfunction in patients with cardiac arrest (CA). Histidine–tryptophan–ketoglutarate (HTK) solution is a preservative used during organ transplantation. Can HTK also protect neurons from severe hypoxia (SH) following CA? We isolated rat primary cortical neurons and induced SH with or without HTK. Changes in caspase-3, hypoxia-inducible factor 1-alpha (HIF-1α), and NADPH oxidase-4 (NOX4) expression were evaluated at different time points till 72 h. Using a rat asphyxia model, we induced CA-mediated brain damage and then completed resuscitation. HTK or sterile saline was administered into the left carotid artery. Neurological deficit scoring and mortality were evaluated for 3 days. Then the rats were sacrificed for evaluating NOX4 and H2O2 level in blood and brain. In the in vitro study, HTK attenuated SH- and H2O2-mediated cytotoxicity in a volume- and time-dependent manner, associated with persisted HIF-1α expression, reductions in procaspase-3 activation and NOX4 expression. The inhibition of HIF-1α abrogated HTK’s effect on NOX4. In the in vivo study, neurological scores were significantly improved by HTK. H2O2 level, NOX4 activity and NOX4 gene expression were all decreased in the brain specimen of HTK-treated rats. Our results suggest that HTK acts as an effective neuroprotective solution.

scholarly journals microRNA-16 via Twist1 inhibits EMT induced by PM2.5 exposure in human hepatocellular carcinoma

Open Medicine ◽  
2019 ◽  
Vol 14 (1) ◽  
pp. 673-682 ◽  
Author(s):  
Hao Zhang ◽  
Zhihu Li
Keyword(s):  
Hepatocellular Carcinoma ◽  
Cell Line ◽  
Epithelial Mesenchymal Transition ◽  
Smooth Muscle Actin ◽  
Human Hepatocellular Carcinoma ◽  
Luciferase Reporter ◽  
Migration And Invasion ◽  
Dependent Manner ◽  
Mesenchymal Transition

AbstractEpidemiological study has confirmed that PM2.5 (particulate matter with an aerodynamic diameter less than 2.5 μm) is associated with the incidence and progression of human hepatocellular carcinoma (HCC). Accordingly, this study was undertaken to investigate the pro-metastatic effects of PM2.5 on human HCC cell line SMMC-7721 in vitro and to explore the underlying mechanisms. CCK-8 assay was performed to examine the effect of PM2.5 on the proliferation of SMMC-7721 cells; scratch wound assay and transwell matrigel system has been used to examine the effect of PM2.5 on the migration and invasion ability of SMMC-7721 cells; furthermore, effect of PM2.5 on epithelial mesenchymal transition (EMT) of SMMC-7721 cells were examined by examining the EMT markers vimentin, ɑ-smooth muscle actin (ɑ-SMA), and E-cadherin; furthermore, the roles of microRNA-16 (miR-16) and its target Twist1 in PM2.5 induced carcinogenic effects were also examined. Results of CCK-8 assay suggested that PM2.5 promoted the proliferation of SMMC-7721 cells in a dose and time dependent manner. PM2.5 also markedly promoted the migration and invasion ability of SMMC-7721 cells. Moreover, epithelial mesenchymal transition (EMT) was also triggered by PM2.5. On the other hand, microRNA-16 (miR-16) and its target Twist1 was found to be mediated by PM2.5, and miR-16 mimic could suppress the metastatic ability of SMMC-7721 cells exposure to PM2.5 via inversely regulating the expression of Twist1. Furthermore, dual Luciferase reporter assay confirmed the specifically binding of miR-16 to the predicted 3′-UTR of Twist1. The present study confirmed the pro-proliferative and pro-metastatic effect of PM2.5 on HCC cell line SMMC-7721. The possible mechanisms were EMT process induced by PM2.5 in SMMC-7721 cells, which was accompanied by a decrease in miR-16 and increase in Twist1 expression.

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