Low-dose lipopolysaccharide protects nerve cells against spinal cord injury via regulating the PI3K–AKT–Nrf2 signaling pathway

2021 ◽  
pp. 1-9
Author(s):  
Wei-Chao Li ◽  
Shao-Ping Yao ◽  
Jun Zhang ◽  
Wei-Bing Liu ◽  
Jie Liu ◽  
...  

This study explored the molecular mechanism behind the protective effects from low-dose lipopolysaccharide (LPS) on an in-vitro model of spinal cord injury (SCI). For this, PC12 cells were treated with different concentrations of LPS and the cell counting kit-8 assay was used to measure the toxicity of LPS to the cells. Next, we used immunofluorescence to measure nuclear translocation of Nrf2 in PC12 cells. PC12 cells were then treated with IGF-1 (PI3K agonist) and LY294002 (PI3K inhibitor). An in-vitro model of SCI was then established via oxygen–glucose deprivation/reoxygenation. Rates of apoptosis were measured using flow cytometry and the TUNEL assay. Low-dose LPS increased the expression levels of Nrf2, p-PI3K/PI3K, and p-AKT/AKT, and facilitated nuclear translocation of Nrf2. The activation of PI3K–AKT signaling by IGF-1 significantly increased the expression of Nrf2, whereas inhibition of PI3K–AKT signaling significantly decreased the expression of Nrf2. Low-dose LPS reduced the apoptotic ratio of PC12 cells, decreased the expression levels of caspase 3 and caspase 9, and increased the expression levels of HO-1, NQO1, and γ-GCS. Low-dose LPS also reduced the rate of apoptosis and oxidative stress by activating the PI3K–AKT–Nrf2 signaling pathway. Collectively, the results indicate that PI3K–AKT–Nrf2 signaling participates in the protective effects from low-dose LPS in an in-vitro PC12 cell model of SCI.

2020 ◽  
Vol 14 (5) ◽  
pp. 616-623
Author(s):  
Yun-Feng Liu ◽  
Yong-Mei Guan ◽  
Shi-Yu Huang ◽  
Lu Wu ◽  
Wei-Feng Zhu ◽  
...  

This research sought to study the influence and potentialmechanism of paeoniflorin and albiflorin on strychnine and brucine transport in MDCK-MDR1 cells regulated by P-gp. Cytotoxicity of drugs was tested by MTT assay, and the transport studies were performed in both directions in MDCK-MDR1 cells. The influence of drugs on P-gp ATPase, and the efflux function of P-gp, the expression levels of P-gp and MDR1 mRNA were also estimated. Strychnine and brucine showed well absorption, and the main transport mechanism might be passive diffusion. Verapamil could significantly decrease the efflux rate (ER) of strychnine and brucine, while the ER of strychnine and brucine was increased significantly when co-administrated with paeoniflorin or albiflorin, indicating that paeoniflorin and albiflorin could promote the efflux of these two alkaloids. Strychnine and brucine could activate the activity of P-gp ATPase, suppress the efflux function of P-gp, but have no significant effect on the expression of P-gp. In addition, strychnine could upregulate the expression of MDR1 mRNA. Paeoniflorin and albiflorin could increase the transmembrane transport of strychnine and brucine mediated by P-gp when co-administrated with strychnine or brucine via stimulating the activity of P-gp ATPase, enhancing the efflux function of P-g, increasing the expression levels of MDR1 mRNA and P-gp.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Golnaz Anvari ◽  
Evangelia Bellas

AbstractIn obese adipose tissue (AT), hypertrophic expansion of adipocytes is not matched by new vessel formation, leading to AT hypoxia. As a result, hypoxia inducible factor-1⍺ (HIF-1⍺) accumulates in adipocytes inducing a transcriptional program that upregulates profibrotic genes and biosynthetic enzymes such as lysyl oxidase (LOX) synthesis. This excess synthesis and crosslinking of extracellular matrix (ECM) components cause AT fibrosis. Although fibrosis is a hallmark of obese AT, the role of fibroblasts, cells known to regulate fibrosis in other fibrosis-prone tissues, is not well studied. Here we have developed an in vitro model of AT to study adipocyte-fibroblast crosstalk in a hypoxic environment. Further, this in vitro model was used to investigate the effect of hypoxia on adipocyte mechanical properties via ras homolog gene family member A (RhoA)/Rho-associated coiled-coil kinases (ROCK) signaling pathways. We confirmed that hypoxia creates a diseased phenotype by inhibiting adipocyte maturation and inducing actin stress fiber formation facilitated by myocardin-related transcription factor A (MRTF-A/MKL1) nuclear translocation. This work presents new potential therapeutic targets for obesity by improving adipocyte maturation and limiting mechanical stress in obese AT.


2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Chang Liu ◽  
Bozhao Li ◽  
Qi Yan ◽  
Shaopeng Niu ◽  
Yiding Zhao ◽  
...  

Ischemic heart disease (IHD) is a cardiovascular disease with high fatality rate, and its pathogenesis is closely related to oxidative stress. Reactive oxygen species (ROS) in oxidative stress can lead to myocardial ischemia (MI) injury in many ways. Therefore, the application of antioxidants may be an effective way to prevent IHD. In recent years, glutathione peroxidase 4 (GPx4) has received increasing attention due to its antioxidant effect. In a previous study, we used the new chimeric tRNAUTuT6 to express highly active recombinant human GPx4 (rhGPx4) in amber-less Escherichia coli. In this study, we established an isoproterenol- (ISO-) induced MI injury model in rats and an in vitro model to research the protective effect and mechanism of rhGPx4 on MI injury. The results showed that rhGPx4 could reduce the area of myocardial infarction and ameliorate the pathological injury of heart tissue, significantly reduce ISO-induced abnormalities on electrocardiogram (ECG) and cardiac serum biomarkers, protect mitochondrial function, and attenuate cardiac oxidative stress injury. In an in vitro model, the results also confirmed that rhGPx4 could inhibit ISO-induced oxidative stress injury and cardiomyocyte apoptosis. The mechanism of action of rhGPx4 involves not only the inhibition of lipid peroxidation by eliminating ROS but also keeping a normal level of endogenous antioxidant enzymes by eliminating ROS, thereby preventing oxidative stress injury in cardiomyocytes. Additionally, rhGPx4 could inhibit cardiomyocyte apoptosis through a mitochondria-dependent pathway. In short, rhGPx4, a recombinant antioxidant enzyme, can play an important role in the prevention of IHD and may have great potential for application.


Fitoterapia ◽  
2020 ◽  
Vol 143 ◽  
pp. 104553 ◽  
Author(s):  
Agnese Gugliandolo ◽  
Federica Pollastro ◽  
Placido Bramanti ◽  
Emanuela Mazzon

2021 ◽  
pp. 112609
Author(s):  
Glen M. DeLoid ◽  
Xiaoqiong Cao ◽  
Dimitrios Bitounis ◽  
Dilpreet Singh ◽  
Paula Montero Llopis ◽  
...  

2013 ◽  
Vol 750-752 ◽  
pp. 1545-1548
Author(s):  
Kuang Ren ◽  
Yan Chun Wang ◽  
Hong Yan Fan

In this study, schisandrin was assessed for potential protective effects on pheochromocytoma cell line (PC12 cells). Using PC12 cells damage induced by H2O2(25μmol/L) as in vitro model. After pre-treatment with different concentration of schisandrin (0.3, 0.6, 1.2μM) for 24h, MTT assay was used to detect the cell viability, the supernatant of cells was collected to examine the levels of nitric oxide (NO) in each sample, and immunocytochemical staining was adopted to observe the expression levels of bcl-2. Results showed that schisandrin at different concentrations could increase the viability of PC12 cells and decrease the levels of NO in the culture medium. There were significant differences between schisandrin group and H2O2group (P<0.05,P<0.01). Immunocytochemical staining result revealed that schisandrin could upregulate bcl-2 protein expression. In summary, schisandrin shown significant neuroprotective effects on H2O2-injured PC12 cells through antioxidant properties and upregulate bcl-2 protein expression, and could be a potential candidate for intervention in neurodegenerative diseases.


Antioxidants ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 54 ◽  
Author(s):  
Gabriele Carullo ◽  
Paolo Governa ◽  
Umile Gianfranco Spizzirri ◽  
Marco Biagi ◽  
Fabio Sciubba ◽  
...  

Inflammatory bowel disease and food allergies are a growing topic in the field of nutrition science. Polyphenols, which are the most important secondary metabolites of plants, demonstrated to modulate the expression and/or production of numerous proteins, but also to regulate the intestinal ecosystem. In this context, our aim was the investigation of protective effects against the gastrointestinal mucosa of fortified milk kefir obtained by adding seeds extract from Sangiovese cv. Pomace. Methods: An ultrasound-assisted method was used to obtain the extracts. All the extracts were assayed for the antioxidant activity. The best extract was used as an additive of fermented milk kefir to obtain a fortified final product. Kefir samples were analyzed by NMR spectroscopy. The efficiency of the barrier functions was evaluated by measuring trans-epithelial electric resistance (TEER) using a voltmeter. Results: the enriched kefir (Ksgn) possesses higher antioxidant performances compared to the unfortified sample (Kwht). Kwht and Ksgn did not alter Caco-2 TEER in basal condition.


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