scholarly journals Resveratrol Protects against Sepsis-Associated Encephalopathy and Inhibits the NLRP3/IL-1βAxis in Microglia

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Da-ming Sui ◽  
Qun Xie ◽  
Wen-jing Yi ◽  
Sahil Gupta ◽  
Xi-ya Yu ◽  
...  

Sepsis-associated encephalopathy (SAE) is characterized as brain dysfunction associated with sepsis. In this study we sought to investigate the effects of resveratrol in mice with SAE, as well as its effects in NLRP3 inflammasome and IL-1β, which were critical in the pathogenesis of SAE. SAE was induced in mice via cecal ligation and puncture (CLP), and resveratrol was administered at two doses after surgery. Spatial learning memory functions were evaluated by Morris water maze testing. Apoptosis in the hippocampus was quantified using TUNEL assay. Inflammation in the hippocampus was quantified by measuring the levels of microglial activation, NLRP3, and IL-1β. CLP mice treated with resveratrol demonstrated a better spatial memory during water maze training. The TUNEL assay demonstrated significantly attenuated rates of apoptosis, in resveratrol treated mice, while decreasing the number of iba-1 positive microglia in the hippocampus region. NLRP3 expression and IL-1βcleavage were well inhibited by resveratrol dose-dependently. Thein vitroresults showed that in the BV2 cell lines resveratrol prevents ATP induced NLRP3 activation and IL-1βcleavage, which were reversed by the sirtuin 1 inhibitor, nicotinamide. In conclusion, resveratrol improves the spatial memory in mice with SAE and inhibits the NLRP3/IL-1βaxis in the microglia.

2021 ◽  
Vol 12 (7) ◽  
Author(s):  
Yu Tian ◽  
Bo Tang ◽  
Chengye Wang ◽  
Yan Wang ◽  
Jiakai Mao ◽  
...  

AbstractOncogenic ubiquitin-specific protease 22 (USP22) is implicated in a variety of tumours; however, evidence of its role and underlying molecular mechanisms in cholangiocarcinoma (CCA) development remains unknown. We collected paired tumour and adjacent non-tumour tissues from 57 intrahepatic CCA (iCCA) patients and evaluated levels of the USP22 gene and protein by qPCR and immunohistochemistry. Both the mRNA and protein were significantly upregulated, correlated with the malignant invasion and worse OS of iCCA. In cell cultures, USP22 overexpression increased CCA cell proliferation and mobility, and induced epithelial-to-mesenchymal transition (EMT). Upon an interaction, USP22 deubiquitinated and stabilized sirtuin-1 (SIRT1), in conjunction with Akt/ERK activation. In implantation xenografts, USP22 overexpression stimulated tumour growth and metastasis to the lungs of mice. Conversely, the knockdown by USP22 shRNA attenuated the tumour growth and invasiveness in vitro and in vivo. Furthermore, SIRT1 overexpression reversed the USP22 functional deficiency, while the knockdown acetylated TGF-β-activated kinase 1 (TAK1) and Akt. Our present study defines USP22 as a poor prognostic predictor in iCCA that cooperates with SIRT1 and facilitates tumour development.


Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1433
Author(s):  
Ok-Hyeon Kim ◽  
Jun-Hyung Park ◽  
Jong-In Son ◽  
Ok-Ja Yoon ◽  
Hyun-Jung Lee

Suitable scaffolds with appropriate mechanical and biological properties can improve mesenchymal stromal cell (MSC) therapy. Because silk fibroins (SFs) are biocompatible materials, they were electrospun and applied as scaffolds for MSC therapy. Consequently, interferon (IFN)-primed human bone marrow MSCs on SF nanofibers were administered into a polymicrobial sepsis murine model. The IL-6 level gradually decreased from 40 ng/mL at 6 h after sepsis to 35 ng/mL at 24 h after sepsis. The IL-6 level was significantly low as 5 ng/mL in primed MSCs on SF nanofibers, and 15 ng/mL in primed MSCs on the control surface. In contrast to the acute response, inflammation-related factors, including HO-1 and COX-2 in chronic liver tissue, were effectively inhibited by MSCs on both SF nanofibers and the control surface at the 5-day mark after sepsis. An in vitro study indicated that the anti-inflammatory function of MSCs on SF nanofibers was mediated through enhanced COX-2-PGE2 production, as indomethacin completely abrogated PGE2 production and decreased the survival rate of septic mice. Thus, SF nanofiber scaffolds potentiated the anti-inflammatory and immunomodulatory functions of MSCs, and were beneficial as a culture platform for the cell therapy of inflammatory disorders.


2021 ◽  
Vol 12 (4) ◽  
Author(s):  
Pei-Yao Liu ◽  
Cheng-Cheung Chen ◽  
Chia-Ying Chin ◽  
Te-Jung Liu ◽  
Wen-Chiuan Tsai ◽  
...  

AbstractIn obese adults, nonalcoholic fatty liver disease (NAFLD) is accompanied by multiple metabolic dysfunctions. Although upregulated hepatic fatty acid synthesis has been identified as a crucial mediator of NAFLD development, the underlying mechanisms are yet to be elucidated. In this study, we reported upregulated expression of gene related to anergy in lymphocytes (GRAIL) in the livers of humans and mice with hepatic steatosis. Grail ablation markedly alleviated the high-fat diet-induced hepatic fat accumulation and expression of genes related to the lipid metabolism, in vitro and in vivo. Conversely, overexpression of GRAIL exacerbated lipid accumulation and enhanced the expression of lipid metabolic genes in mice and liver cells. Our results demonstrated that Grail regulated the lipid accumulation in hepatic steatosis via interaction with sirtuin 1. Thus, Grail poses as a significant molecular regulator in the development of NAFLD.


2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Rinie Bajracharya ◽  
David Brici ◽  
Liviu-Gabriel Bodea ◽  
Phillip W. Janowicz ◽  
Jürgen Götz ◽  
...  

AbstractOne of the main pathological hallmarks of Alzheimer’s disease (AD) is the intraneuronal accumulation of hyperphosphorylated tau. Passive immunotherapy is a promising strategy for the treatment of AD and there are currently a number of tau-specific monoclonal antibodies in clinical trials. A proposed mechanism of action is to engage and clear extracellular, pathogenic forms of tau. This process has been shown in vitro to be facilitated by microglial phagocytosis through interactions between the antibody-tau complex and microglial Fc-receptors. As this interaction is mediated by the conformation of the antibody's Fc domain, this suggests that the antibody isotype may affect the microglial phagocytosis and clearance of tau, and hence, the overall efficacy of tau antibodies. We therefore aimed to directly compare the efficacy of the tau-specific antibody, RN2N, cloned into a murine IgG1/κ framework, which has low affinity Fc-receptor binding, to that cloned into a murine IgG2a/κ framework, which has high affinity Fc-receptor binding. Our results demonstrate, for RN2N, that although enhanced microglial activation via the IgG2a/κ isotype increased extracellular tau phagocytosis in vitro, the IgG1/κ isoform demonstrated enhanced ability to reduce tau pathology and microgliosis following passive immunisation of the P301L tau transgenic pR5 mouse model.


2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Xiaoxia Ye ◽  
Mingming Zhu ◽  
Xiaohang Che ◽  
Huiyang Wang ◽  
Xing-Jie Liang ◽  
...  

Abstract Background Microglial activation is a prominent feature of neuroinflammation, which is present in almost all neurodegenerative diseases. While an initial inflammatory response mediated by microglia is considered to be protective, excessive pro-inflammatory response of microglia contributes to the pathogenesis of neurodegeneration. Although autophagy is involved in the suppression of inflammation, its role and mechanism in microglia are unclear. Methods In the present study, we studied the mechanism by which lipopolysaccharide (LPS) affects microglial autophagy and the effects of autophagy on the production of pro-inflammatory factors in microglial cells by western blotting, immunocytochemistry, transfection, transmission electron microscopy (TEM), and real-time PCR. In a mouse model of neuroinflammation, generated by intraventricular injection of LPS (5 μg/animal), we induced autophagy by rapamycin injection and investigated the effects of enhanced autophagy on microglial activation by enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry. Results We found that autophagic flux was suppressed in LPS-stimulated N9 microglial cells, as evidenced by decreased expression of the autophagy marker LC3-II (lipidated form of MAP1LC3), as well as increased levels of the autophagy adaptor protein SQSTM1. LPS significantly decreased Vps34 expression in N9 microglial cells by activating the PI3KI/AKT/MTOR pathway without affecting the levels of lysosome-associated proteins and enzymes. More importantly, overexpression of Vps34 significantly enhanced the autophagic flux and decreased the accumulation of SQSTM1 in LPS-stimulated N9 microglial cells. Moreover, our results revealed that an LPS-induced reduction in the level of Vps34 prevented the maturation of omegasomes to phagophores. Furthermore, LPS-induced neuroinflammation was significantly ameliorated by treatment with the autophagy inducer rapamycin both in vitro and in vivo. Conclusions These data reveal that LPS-induced neuroinflammation in N9 microglial cells is associated with the inhibition of autophagic flux through the activation of the PI3KI/AKT/MTOR pathway, while enhanced microglial autophagy downregulates LPS-induced neuroinflammation. Thus, this study suggests that promoting the early stages of autophagy might be a potential therapeutic approach for neuroinflammation-associated diseases.


Author(s):  
Mahmoud Hashemzaei ◽  
Najmeh Baratzadeh ◽  
Iraj Sharamian ◽  
Sahar Fanoudi ◽  
Mehdi Sanati ◽  
...  

Abstract Objectives H-89 (a protein kinase AII [PKA II] inhibitor) impairs the spatial memory in the Morris water maze task in rats. In the present study, we aimed to study the protective effects of nicotine and O-acetyl-L-carnitine against H-89-induced spatial memory deficits. Methods Spatial memory impairment was induced by the bilateral intrahippocampal administration of 10 µM H-89 (dissolved in dimethyl sulfoxide, DMSO) to rats. The rats then received bilateral administrations of either nicotine (1 μg/μL, dissolved in saline) or O-acetyl-L-carnitine (100 μM/side, dissolved in deionized water) alone and in combination. Control groups received either saline, deionized water, or DMSO. Results The H-89-treated animals showed significant increases in the time and distance travelled to find hidden platforms, and there was also a significant decrease in the time spent in the target quadrant compared to DMSO-treated animals. Nicotine and O-acetyl-L-carnitine had no significant effects on H-89-induced spatial learning impairments alone, but the bilateral intrahippocampal co-administration of nicotine and O-acetyl-L-carnitine prevented H-89-induced spatial learning deficits and increased the time spent in the target quadrant in comparison with H-89-treated animals. Conclusions Our results indicated the potential synergistic effects of nicotine and O-acetyl-L-carnitine in preventing protein kinase AII inhibitor (H-89)-induced spatial learning impairments.


1995 ◽  
Vol 182 (1) ◽  
pp. 267-272 ◽  
Author(s):  
T E Read ◽  
C Grunfeld ◽  
Z L Kumwenda ◽  
M C Calhoun ◽  
J P Kane ◽  
...  

Triglyceride-rich lipoproteins bind and inactive bacterial endotoxin in vitro and prevent death when given before a lethal dose of endotoxin in animals. However, lipoproteins have not yet been demonstrated to improve survival in polymicrobial gram-negative sepsis. We therefore tested the ability of triglyceride-rich lipoproteins to prevent death after cecal ligation and puncture (CLP) in rats. Animals were given bolus infusions of either chylomicrons (1 g triglyceride/kg per 4 h) or an equal volume of saline for 28 h after CLP. Chylomicron infusions significantly improved survival (measured at 96 h) compared with saline controls (80 vs 27%, P < or = 0.03). Chylomicron infusions also reduced serum levels of endotoxin, measured 90 min (26 +/- 3 vs 136 +/- 51 pg/ml, mean +/- SEM, P < or = 0.03) and 6 h (121 +/- 54 vs 1,026 +/- 459 pg/ml, P < or = 0.05) after CLP. The reduction in serum endotoxin correlated with a reduction in serum tumor necrosis factor, measured 6 h after CLP (0 +/- 0 vs 58 +/- 24 pg/ml, P < or = 0.03), suggesting that chylomicrons improve survival in this model by limiting macrophage exposure to endotoxin and thereby reducing secretion of inflammatory cytokines. Infusions of a synthetic triglyceride-rich lipid emulsion (Intralipid; KabiVitrum, Inc., Alameda, CA) (1 g triglyceride/kg) also significantly improved survival compared with saline controls (71 vs 27%, P < or = 0.03). These data demonstrate that triglyceride-rich lipoproteins can protect animals from lethal polymicrobial gram-negative sepsis.


2016 ◽  
Vol 38 (3) ◽  
pp. 859-870 ◽  
Author(s):  
Mingfeng He ◽  
Hongquan Dong ◽  
Yahui Huang ◽  
Shunmei Lu ◽  
Shu Zhang ◽  
...  

Background/Aims: Microglia are an essential player in central nervous system inflammation. Recent studies have demonstrated that the astrocytic chemokine, CCL2, is associated with microglial activation in vivo. However, CCL2-induced microglial activation has not yet been studied in vitro. The purpose of the current study was to understand the role of astrocyte-derived CCL2 in microglial activation and to elucidate the underlying mechanism(s). Methods: Primary astrocytes were pre-treated with CCL2 siRNA and stimulated with TNF-α. The culture medium (CM) was collected and added to cultures of microglia, which were incubated with and without CCR2 inhibitor. Microglial cells were analyzed by quantitative RT-PCR to determine whether they polarized to the M1 or M2 state. Microglial migratory ability was assessed by transwell migration assay. Results: TNF-α stimulated the release of CCL2 from astrocytes, even if the culture media containing TNF-α was replaced with fresh media after 3 h. CM from TNF-α-stimulated astrocytes successfully induced microglial activation, which was ascertained by increased activation of M1 and enhanced migration ability. In contrast, CM from astrocytes pretreated with CCL2 siRNA showed no effect on microglial activation, compared to controls. Additionally, microglia pre-treated with RS102895, a CCR2 inhibitor, were resistant to activation by CM from TNF-α-stimulated astrocytes. Conclusion: This study demonstrates that the CCL2/CCR2 pathway of astrocyte-induced microglial activation is associated with M1 polarization and enhanced migration ability, indicating that this pathway could be a useful target to ameliorate inflammation in the central nervous system.


2012 ◽  
Vol 303 (10) ◽  
pp. F1443-F1453 ◽  
Author(s):  
Chung-Hsi Hsing ◽  
Chiou-Feng Lin ◽  
Edmund So ◽  
Ding-Ping Sun ◽  
Tai-Chi Chen ◽  
...  

Bone morphogenetic protein (BMP)-7 protects sepsis-induced acute kidney injury (AKI). Dexmedetomidine (DEX), an α2-adrenoceptor (α2-AR) agonist, has anti-inflammatory effects. We investigated the protective effects of DEX on sepsis-induced AKI and the expression of BMP-7 and histone deacetylases (HDACs). In vitro , the effects of DEX or trichostatin A (TSA, an HDAC inhibitor) on TNF-α, monocyte chemotactic protein (MCP-1), BMP-7, and HDAC mRNA expression in LPS-stimulated rat renal tubular epithelial NRK52E cells, was determined using real-time PCR. In vivo, mice were intraperitoneally injected with DEX (25 μg/kg) or saline immediately and 12 h after cecal ligation and puncture (CLP) surgery. Twenty-four hours after CLP, we examined kidney injury and renal TNF-α, MCP-1, BMP-7, and HDAC expression. Survival was monitored for 120 h. LPS increased HDAC2, HDAC5, TNF-α, and MCP-1 expression, but decreased BMP-7 expression in NRK52E cells. DEX treatment decreased the HDAC2, HDAC5, TNF-α, and MCP-1 expression, but increased BMP-7 and acetyl histone H3 expression, whose effects were blocked by yohimbine, an α2-AR antagonist. With DEX treatment, the LPS-induced TNF-α expression and cell death were attenuated in scRNAi-NRK52E but not BMP-7 RNAi-NRK52E cells. In CLP mice, DEX treatment increased survival and attenuated AKI. The expression of HDAC2, HDAC5, TNF-α, and MCP-1 mRNA in the kidneys of CLP mice was increased, but BMP-7 was decreased. However, DEX treatment reduced those changes. DEX reduces sepsis-induced AKI by decreasing TNF-α and MCP-1 and increasing BMP-7, which is associated with decreasing HDAC2 and HDAC5, as well as increasing acetyl histone H3.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Junli Sun ◽  
Keke Xin ◽  
Chenghui Leng ◽  
Jianlin Ge

Abstract Background Long noncoding RNAs contribute to various inflammatory diseases, including sepsis. We explore the role of small nucleolar RNA host gene 16 (SNHG16) in sepsis-mediated acute lung injury (ALI) and inflammation. Methods A sepsis-induced ALI rat model was constructed by the cecal ligation and perforation method. The profiles of SNHG16, miR-128-3p, and high-mobility group box 3 (HMGB3) were monitored by quantitative reverse transcription PCR and Western blot. The pathologic changes of lung tissues were evaluated by Hematoxylin–Eosin staining, immunohistochemistry, and dry and wet method. Meanwhile, the pro-inflammatory factors and proteins were determined by ELISA and Western blot. In contrast, a sepsis model in BEAS-2B was induced with lipopolysaccharide (LPS) to verify the effects of SNHG16/miR-128-3p/HMGB3 on lung epithelial cell viability and apoptosis. Results As a result, SNHG16 and HMGB3 were up-regulated, while miR-128-3p was down-regulated in sepsis-induced ALI both in vivo and in vitro. Inhibiting SNHG16 reduced the apoptosis and inflammation in the sepsis-induced ALI model. Overexpressing SNHG16 promoted LPS-mediated lung epithelial apoptosis and inhibited cell viability and inflammation, while miR-128-3p had the opposite effects. Mechanistically, SNHG16 targeted miR-128-3p and attenuated its expression, while miR-128-3p targeted the 3′ untranslated region of HMGB3. Conclusions Overall, down-regulating SNHG16 alleviated the sepsis-mediated ALI by regulating miR-128-3p/HMGB3.


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