scholarly journals Melatonin protects against LPS-induced inflammation and oxidative stress in hepatocytes by enhancing mitophagy and mitochondrial biogenesis

Author(s):  
Bin Hu ◽  
Zhijiang Chen ◽  
Lili Liang ◽  
Meiyu Zheng ◽  
Yaxin Wang ◽  
...  

Abstract Background: Melatonin have a protective effect in the liver during sepsis by counteracting oxidative stress and reducing inflammatory responses. Melatonin also regulates mitochondrial biogenesis. This study explored the mechanisms by which melatonin protects against liver injury in experimental sepsis with a focus on mitophagy and mitochondrial biogenesis.Methods and Results: An in vitro model of sepsis-induced hepatocyte injury was established using AML12 cells. Indicators of oxidative stress, inflammation, mitophagy and mitochondrial biogenesis were assessed. Tumor necrosis factor (TNF)-α and interleukin (IL)-6 protein levels, intracellular reactive oxygen species (ROS) levels, lipid peroxidation (malondialdehyde [MDA] levels), and markers of mitophagy (PTEN-induced putative kinase 1 [PINK1] and Parkin) and mitochondrial biogenesis (peroxisome proliferator-activated receptor-gamma coactivator 1a [PGC-1α], nuclear respiratory factor 1 [NRF-1], mitochondrial transcription factor A [TFAM]) were significantly increased, while superoxide dismutase (SOD) activity and intracellular adenosine triphosphate (ATP) levels were significantly decreased in LPS-treated AML12 cells compared to controls. TNF-α and IL-6 protein levels and intracellular ROS and MDA levels were significantly decreased, while SOD activity, intracellular ATP levels, and markers of mitophagy and mitochondrial biogenesis were significantly increased by melatonin pre-treatment.Conclusion: This study demonstrated that melatonin was involved in the maintenance of mitochondrial homeostasis in hepatocytes during sepsis. Mechanisms involved selective elimination of dysfunctional mitochondria through mitophagy and induction of mitochondrial biogenesis.

2021 ◽  
Vol 8 ◽  
Author(s):  
Yiling Liao ◽  
Enzheng Zhu ◽  
Wanxing Zhou

Background: Oxidized low-density lipoprotein (ox-LDL) can induce oxidative stress and inflammatory responses in macrophages to facilitate the genesis and development of atherosclerosis. However, the intermediate links remain unclear. MiR-491-5P can inhibit matrix metalloproteinase 9 (MMP-9); however, it remains unclear whether ox-LDL enhances MMP-9 expression and aggravates the oxidative stress and inflammatory responses under the mediating effect of miR-491-5P.Method: THP-1 macrophages were divided into 10 groups: blank (control), model (ox-LDL), miR-491-5P high-expression (miR-491-5P mimic), miR-491-5P control (mimic-NC), MMP-9 high-expression (MMP-9-plasmid), MMP-9 control (plasmid-NC), miR-491-5P+plasmid-NC, miR-491-5P+ MMP-9-plasmid, MMP-9 gene silencing (MMP-9-siRNA), and gene silencing control (siRNA-NC). The cells were transfected for 48 h and then treated with 50 μg/mL of ox-LDL for 24 h. MMP-9 mRNA and miR-491-5P expression levels in the cells were detected using reverse transcription-quantitative polymerase chain reaction, and the MMP-9 levels were detected with western blotting. The levels of oxidative stress factors (malondialdehyde [MDA]), reactive oxygen species (ROS), and antioxidant factors (superoxide dismutase [SOD]), and the expression levels of inflammatory factors (tumor necrosis factor [TNF-α] and interleukin-1β and−6 [IL-1β and IL-6]) in the supernatant were detected with enzyme-linked immunosorbent assay.Results: MDA, ROS, TNF-α, IL-1β, IL-6, and MMP-9 levels were increased, SOD activity was reduced, and miR-491-5P expression was downregulated in the ox-LDL group compared to the control group. In the miR-491-5P mimic group, the MDA, ROS, TNF-α, IL-1β, IL-6, MMP-9 mRNA and protein levels were downregulated, and SOD activity was enhanced compared to the ox-LDL group. MMP-9-plasmid elevated the MDA, ROS, TNF-α, IL-1β, IL-6, MMP-9 mRNA and protein levels, and downregulated SOD activity and miR-491-5P expression. Following transfection with MMP-9-siRNA, the MMP-9-plasmid outcomes were nullified, and the resulting trends were similar to the miR-491-5p simulation group. Oxidative stress and inflammatory responses were higher in the miR-491-5P mimic+MMP-9-plasmid co-transfection group than in the miR-491-5P mimic group.Conclusion: Ox-LDL aggravates the oxidative stress and inflammatory responses of THP-1 macrophages by reducing the inhibition effect of miR-491-5p on MMP-9.


2016 ◽  
Vol 38 (6) ◽  
pp. 2163-2172 ◽  
Author(s):  
Xiaorong Hu ◽  
Ruisong Ma ◽  
Jiajia Lu ◽  
Kai Zhang ◽  
Weipan Xu ◽  
...  

Background/Aims: Inflammation and oxidative stress play an important role in myocardial ischemia and reperfusion (I/R) injury. We hypothesized that IL-23, a pro-inflammatory cytokine, could promote myocardial I/R injury by increasing the inflammatory response and oxidative stress. Methods: Male Sprague-Dawley rats were randomly assigned into sham operated control (SO) group, ischemia and reperfusion (I/R) group, (IL-23 + I/R) group and (anti-IL-23 + I/R) group. At 4 h after reperfusion, the serum concentration of lactate dehydrogenase (LDH), creatine kinase (CK) and the tissue MDA concentration and SOD activity were measured. The infarcte size was measured by TTC staining. Apoptosis in heart sections were measured by TUNEL staining. The expression of HMGB1 and IL-17A were detected by Western Blotting and the expression of TNF-α and IL-6 were detected by Elisa. Results: After 4 h reperfusion, compared with the I/R group, IL-23 significantly increased the infarct size, the apoptosis of cardiomyocytes and the levels of LDH and CK (all P < 0.05). Meanwhile, IL-23 significantly increased the expression of eIL-17A, TNF-α and IL-6 and enhanced both the increase of the MDA level and the decrease of the SOD level induced by I/R (all P<0.05). IL-23 had no effect on the expression of HMGB1 (p > 0.05). All these effects were abolished by anti-IL-23 administration. Conclusion: The present study suggested that IL-23 may promote myocardial I/R injury by increasing the inflammatory responses and oxidative stress reaction.


2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Huanjin Song ◽  
Hao Wu ◽  
Jun Dong ◽  
Sihua Huang ◽  
Jintao Ye ◽  
...  

Ellagic acid (EA) was reported to play protective roles in rheumatoid arthritis (RA). It was found that the level of metastasis-associated gene 1 (MTA1)/histone deacetylase 1 (HDAC1) protein complex was downregulated by polyphenols in several human disorders. Notably, inhibition of MTA1 or HDAC1 has anti-inflammatory effects on RA. Therefore, our study is aimed at investigating whether EA prevents RA progression through regulating the MTA1/HDAC1 complex. Herein, the human fibroblast-like synoviocyte (FLS) cell line MH7A was treated with TNF-α to induce an inflammation model in vitro and then incubated with different concentrations of EA. Western blot analysis showed that EA reduced MTA1 expression in a dose-dependent manner in MH7A cells. Then, TNF-α-treated MH7A cells were incubated with EA alone or together with MTA1 overexpression plasmid (pcDNA-MTA1), and we found that EA inhibited proliferation, inflammation cytokine levels, and oxidative stress marker protein levels and promoted apoptosis in MH7A cells, while MTA1 overexpression abolished these effects. Moreover, coimmunoprecipitation assay verified the interaction between MTA1 and HDAC1. EA downregulated the MTA1/HDAC1 complex in MH7A cells. MTA1 knockdown inhibited proliferation, inflammation, and oxidative stress and promoted apoptosis in MH7A cells, while HDAC1 overexpression reversed these effects. Moreover, chromatin immunoprecipitation assay indicated that EA inhibited HDAC1-mediated Nur77 deacetylation. Rescue experiments demonstrated that Nur77 knockdown reversed the effects of EA on MH7A cell biological behaviors. Additionally, EA treatment attenuated arthritis index, paw swelling, synovial hyperplasia, and inflammation in collagen-induced arthritis (CIA) rats. In conclusion, EA inhibited proliferation, inflammation, and oxidative stress and promoted apoptosis in MH7A cells and alleviated the severity of RA in CIA rats though downregulating MTA1/HDAC1 complex and promoting HDAC1 deacetylation-mediated Nur77 expression.


Pharmacology ◽  
2019 ◽  
Vol 105 (1-2) ◽  
pp. 109-117 ◽  
Author(s):  
Jing Ma ◽  
Ranran Wang ◽  
Haijing Yan ◽  
Renjie Xu ◽  
Ajing Xu ◽  
...  

Objectives: Sepsis-induced inflammation injury and oxidative stress are well known causes of mortality. The anti-inflammatory effects of baicalin have been proposed in a mouse model of experimental sepsis. Here, we investigated its protective effects and associated mechanisms with respect to lipopolysaccharide (LPS)-induced injury in Caenorhabditis elegans. Methods: Worms were stimulated by LPS (100 μg/mL), with baicalin (1, 10, 100 μmol/L), for 24 h. Animal survival rates and behaviors (reversal and omega turn) were then determined. Further, levels of the inflammatory cytokines interleukin 6 (IL-6), IL-1, and tumor necrosis factor (TNF)-α were detected by enzyme-linked immunosorbent assay. Western blotting was also performed to determine the protein expression levels of Toll-like receptor 4 (TLR4), nuclear factor-κB (NF-κB), Bax, and Bcl-2. The activities of malondialdehyde (MDA) and superoxide dismutase (SOD) contents were determined using corresponding kits. Results: Baicalin (10, 100 μmol/L) improved LPS-stimulated C. elegans survival and rescued behavioral phenotypes. It also suppressed the oxidative stress related to LPS injury by decreasing MDA levels and increasing SOD activity. Moreover, the inflammatory response was inhibited as evidenced by decreased levels of cytokines including IL-6, IL-1, and TNF-α. In addition, baicalin treatment significantly decreased cleaved Bax levels and increased Bcl-2 expression in C. elegans treated with LPS. Simultaneously, the expression of NF-κB and TLR4 was significantly decreased. Conclusion: Baicalin treatment protects against LPS-induced injury by decreasing oxidative stress, repressing the inflammatory cascade, and inhibiting apoptosis.


2008 ◽  
Vol 294 (5) ◽  
pp. E898-E909 ◽  
Author(s):  
Kazuto Takahashi ◽  
Shinya Yamaguchi ◽  
Tatsuhiro Shimoyama ◽  
Hiroyuki Seki ◽  
Kaoru Miyokawa ◽  
...  

Obese conditions increase the expression of adipocytokine monocyte chemoattractant protein-1 (MCP-1) in adipose tissue as well as MCP-1 plasma levels. To investigate the mechanism behind increased MCP-1, we used a model in which 3T3-L1 adipocytes were artificially hypertrophied by preloading with palmitate in vitro. As observed in obesity, under our model conditions, palmitate-preloaded cells showed significantly increased oxidative stress and increased MCP-1 expression relative to control cells. This increased MCP-1 expression was enhanced by adding exogenous tumor necrosis factor-α (TNF-α; 17.8-fold vs. control cells, P < 0.01) rather than interleukin-1β (IL-1β; 2.6-fold vs. control cells, P < 0.01). However, endogenous TNF-α and IL-1β release was not affected in hypertrophied cells, suggesting that these endogenous cytokines do not mediate hypertrophy-induced increase in MCP-1. MCP-1 secretion from hypertrophied cells was significantly decreased by treatment with antioxidant N-acetyl-cysteine, JNK inhibitors SP600125 and JIP-1 peptide, and IκB phosphorylation inhibitors BAY 11-7085 and BMS-345541 ( P < 0.01). MCP-1 secretion was not affected by peroxisome proliferator-activated receptor-γ (PPARγ) antagonists assayed. Adiponectin, another adipocytokine studied in parallel, also showed increased release in hypertrophy relative to control cells. But in contrast to MCP-1, adiponectin release was significantly suppressed by both exogenous TNF-α and IL-1β as well as by PPARγ antagonists bisphenol A diglycidyl ether and T0070907 ( P < 0.01). JNK inhibitors and IκB phosphorylation inhibitors showed no significant effect on adiponectin. We conclude that adipocyte hypertrophy through palmitate loading causes oxidative stress, which in turn increases MCP-1 expression and secretion through JNK and IκB signaling. In contrast, the parallel increase in adiponectin expression appears to be related to the PPARγ ligand properties of palmitate.


2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Qunqun Shan ◽  
Ning Li ◽  
Fan Zhang ◽  
Peng Yu ◽  
Qingxi Meng

During disc degeneration, the increase of inflammatory cytokines and decrease of disc cell density are two prominent features. Enhanced inflammatory reaction contributes to disc annulus fibrosus (AF) cell apoptosis. In this study, we investigated whether resveratrol can suppress AF cell apoptosis in an inflammatory environment. Rat disc AF cells were cultured in medium with or without tumor necrosis factor-α (TNF-α). Resveratrol was added along with the culture medium supplemented with TNF-α. Caspase-3 activity, cell apoptosis ratio, expression of apoptosis-associated molecules (Bcl-2, Bax, caspase-3, cleaved PARP, and cleaved caspase-3), reactive oxygen species (ROS) content, and the total superoxide dismutase (SOD) activity were measured. Our results showed that TNF-α significantly increased caspase-3 activity and AF cell apoptosis ratio and upregulated gene/protein expression of Bax, caspase-3, cleaved caspase-3, and cleaved PARP, whereas it downregulated the expression of Bcl-2. Moreover, TNF-α significantly increased ROS content but decreased the total SOD activity. Further analysis demonstrated that resveratrol partly attenuated the effects of TNF-α on AF cell apoptosis-associated parameters, decreased ROS content, and increased the total SOD activity in the AF cells treated with TNF-α. In conclusion, resveratrol attenuates inflammatory cytokine TNF-α-induced AF cell apoptosis through regulating oxidative stress reaction in vitro. This study sheds a new light on the protective role of resveratrol in alleviating disc degeneration.


2020 ◽  
Author(s):  
Yaping Zhang ◽  
Nan Ding ◽  
Hanlu Yi ◽  
Yudong Zhao ◽  
Daole Yan ◽  
...  

Abstract Background To investigate the potential role of CFTR in myocardial ischemic/reperfusion (I/R) injury and its relationship with mitophagy. Methods Wild type (WT) and age matched CFTR−/− male mice were used to establish the myocardial I/R model. CFTR activator forskolin (FSK) was used to activate CFTR in mice. Hypoxia/reoxygenation (H/R) treatment was used for in vitro model in WT or CFTR−/− cardiomyocytes. The autophagy inhibitor 3-MA and activator rapamycin was used for inhibition or activation of autophagy, respectively. The mitochondrial membrane potential (MMP) and ATP concentration were detected. Immunofluorescence was performed for measurement of mitochondria. Oxidative factors reactive oxygen species (ROS), superoxide dismutase (SOD), malondiadehycle (MDA) and glutathione peroxidase (GSH-PX) were detected. The expression of CFTR, MMP-9, TNF-α, IL-8, LC3 II/I, beclin1, caspase-3, caspase-8, caspase-9, bax, bcl-2, p-62 and FUNDC1 was determined using western blotting or PCR. Results Knockdown of CFTR significantly increased the infraction volume and decreased the expression of autophagy related proteins beclin1 and LC3II/I in mice. In H/R cardiomyocytes, deficiency of CFTR by induced dysfunction of mitochondrial, decrease of ATP concentration and enhanced oxidative stress, as well as inhibited mitophagy and increased cell apoptosis related protein levels. When treated with 3-MA, the effects of overexpression of CFTR was remarkably reversed, while treatment of rapamycin significantly reversed the effects of inhibiting CFTR on both mitophagy, oxidative stress and cell apoptosis related proteins. The inhibition of FUNDC1 also reversed the above effects of overexpressing CFTR. Conclusion Inhibition of CFTR could promote myocardial I/R injury by suppressing FUNDC1-mediated mitophagy and activating of oxidative stress.


2018 ◽  
Vol 15 (4) ◽  
pp. 345-354 ◽  
Author(s):  
Barbara D'Orio ◽  
Anna Fracassi ◽  
Maria Paola Cerù ◽  
Sandra Moreno

Background: The molecular mechanisms underlying Alzheimer's disease (AD) are yet to be fully elucidated. The so-called “amyloid cascade hypothesis” has long been the prevailing paradigm for causation of disease, and is today being revisited in relation to other pathogenic pathways, such as oxidative stress, neuroinflammation and energy dysmetabolism. The peroxisome proliferator-activated receptors (PPARs) are expressed in the central nervous system (CNS) and regulate many physiological processes, such as energy metabolism, neurotransmission, redox homeostasis, autophagy and cell cycle. Among the three isotypes (α, β/δ, γ), PPARγ role is the most extensively studied, while information on α and β/δ are still scanty. However, recent in vitro and in vivo evidence point to PPARα as a promising therapeutic target in AD. Conclusion: This review provides an update on this topic, focussing on the effects of natural or synthetic agonists in modulating pathogenetic mechanisms at AD onset and during its progression. Ligandactivated PPARα inihibits amyloidogenic pathway, Tau hyperphosphorylation and neuroinflammation. Concomitantly, the receptor elicits an enzymatic antioxidant response to oxidative stress, ameliorates glucose and lipid dysmetabolism, and stimulates autophagy.


Author(s):  
Reza Afrisham ◽  
Sahar Sadegh-Nejadi ◽  
Reza Meshkani ◽  
Solaleh Emamgholipour ◽  
Molood Bagherieh ◽  
...  

Introduction: Obesity is a disorder with low-grade chronic inflammation that plays a key role in the hepatic inflammation and steatosis. Moreover, there are studies to support the role of exosomes in the cellular communications, the regulation of metabolic homeostasis and immunomodulatory activity. Accordingly, we aimed to evaluate the influence of plasma circulating exosomes derived from females with normal-weight and obesity on the secretion of inflammatory cytokines in human liver cells. Methods: Plasma circulating exosomes were isolated from four normal (N-Exo) and four obese (O-Exo) women. The exosomes were characterized and approved for CD63 expression (common exosomal protein marker) and morphology/size using the western blot and TEM methods, respectively. The exosomes were used for stimulation of HepG2 cells in vitro. After 24 h incubation, the protein levels of TNF-α,IL-6, and IL-1β were measured in the culture supernatant of HepG2 cells using the ELISA kit. Results: The protein levels of IL-6 and TNF-α in the cells treated with O-Exo and N-Exo reduced significantly in comparison with control group (P=0.039 and P<0.001 respectively), while significance differences were not found between normal and obese groups (P=0.808, and P=0.978 respectively). However, no significant differences were found between three groups in term of IL-1β levels (P=0.069). Based on the correlation analysis, the protein levels of IL-6 were positively correlated with TNF-α (r 0.978, P<0.001). Conclusion: These findings suggest that plasma circulating exosomes have probably anti-inflammatory properties independently from body mass index and may decrease the secretion of inflammatory cytokines in liver. However, further investigations in vitro and in vivo are needed to address the anti-inflammatory function of N-Exo and O-Exo in human liver cells and/or other cells.


Author(s):  
Kiptiyah Kiptiyah ◽  
Widodo Widodo ◽  
Gatot Ciptadi ◽  
Aulanni’am Aulanni’Am ◽  
Mohammad A. Widodo ◽  
...  

AbstractBackgroundWe investigated whether 10-gingerol is able to induce oxidative stress in cumulus cells.MethodsFor the in-vitro research, we used a cumulus cell culture in M199, containing 10-gingerol in various concentrations (0, 12, 16, and 20 µM), and detected oxidative stress through superoxide dismutase (SOD) activity and malondialdehyde (MDA) concentrations, with incubation periods of 24, 48, 72, and 96 h. The obtained results were confirmed by in-silico studies.ResultsThe in-vitro data revealed that SOD activity and MDA concentration increased with increasing incubation periods: SOD activity at 0 µM (1.39 ± 0.24i), 12 µM (16.42 ± 0.35ab), 16 µM (17.28 ± 0.55ab), 20 µM (17.81 ± 0.12a), with a contribution of 71.1%. MDA concentration at 0 µM (17.82 ± 1.39 l), 12 µM (72.99 ± 0.31c), 16 µM (79.77 ± 4.19b), 20 µM (85.07 ± 2.57a), with a contribution of 73.1%. Based on this, the in-silico data uncovered that 10˗gingerol induces oxidative stress in cumulus cells by inhibiting HTR1A functions and inactivating GSK3B and AKT˗1.Conclusions10-gingerol induces oxidative stress in cumulus cells through enhancing SOD activity and MDA concentration by inhibiting HTR1A functions and inactivating GSK3B and AKT˗1.


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