scholarly journals Paraquat Exposure Induces Pulmonary Cell Mitophagy by Enhancing the PINK1/Parkin Signaling

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Kaixiang Liu ◽  
Zhipeng Zhan ◽  
Wei Gao ◽  
Jie Feng ◽  
Xisheng Xie

Paraquat (PQ) poisoning can cause oxidative stress, acute lung injury (ALI), and fibrosis. Excess oxidative stress can induce mitophagy. However, whether PQ exposure can induce mitophagy, contributing to the development of ALI and pulmonary fibrosis in vivo has not been clarified. Here, we show that PQ exposure induces ALI and fiber accumulation in the lung of rats in a time-dependent manner, accompanied by upregulating fibronectin (FN) and Collagen I (COL-I) expression. PQ exposure increased mitophagosome formation and PINK1 and Parkin expression in the lungs of rats. Similarly, PQ exposure reduced the viability and mitochondrial membrane potential, but enhanced FN, COL-I, PINK1, and Parkin expression in A549 cells. In contrast, PINK1 silencing significantly mitigated the PQ-upregulated Parkin, FN, and COL-I expression in A549 cells. Hence, PQ exposure induced ALI and fibrosis in rats by enhancing the PINK1/Parkin signaling and profibrotic factor expression in the lungs. Therefore, our findings suggest that the PINK1/Parkin signaling may be new therapeutic targets and may provide new insights in the pathogenesis of PQ-related ALI in rats.

Zygote ◽  
2019 ◽  
Vol 27 (4) ◽  
pp. 203-213 ◽  
Author(s):  
Anima Tripathi ◽  
Vivek Pandey ◽  
A.N. Sahu ◽  
Alok K. Singh ◽  
Pawan K. Dubey

SummaryThe present study investigated if the presence of encircling granulosa cells protected against di(2-ethylhexyl)phthalate (DEHP)-induced oxidative stress in rat oocytes cultured in vitro. Denuded oocytes and cumulus–oocyte complexes (COCs) were treated with or without various doses of DEHP (0.0, 25.0, 50.0, 100, 200, 400 and 800 μM) in vitro. Morphological apoptotic changes, levels of oxidative stress and reactive oxygen species (ROS), mitochondrial membrane potential, and expression levels of apoptotic markers (Bcl2, Bax, cytochrome c) were analyzed. Our results showed that DEHP induced morphological apoptotic changes in a dose-dependent manner in denuded oocytes cultured in vitro. The effective dose of DEHP (400 µg) significantly (P>0.05) increased oxidative stress by elevating ROS levels and the mitochondrial membrane potential with higher mRNA expression and protein levels of apoptotic markers (Bax, cytochrome c). Encircling granulosa cells protected oocytes from DEHP-induced morphological changes, increased oxidative stress and ROS levels, as well as increased expression of apoptotic markers. Taken together our data suggested that encircling granulosa cells protected oocytes against DEHP-induced apoptosis and that the presence of granulosa cells could act positively towards the survival of oocytes under in vitro culture conditions and may be helpful during assisted reproductive technique programmes.


1992 ◽  
Vol 263 (2) ◽  
pp. C405-C411 ◽  
Author(s):  
Y. Park ◽  
T. M. Devlin ◽  
D. P. Jones

The dimer and trimer of 16,16-dimethyl-15-dehydroprostaglandin B1 (16,16-diMePGB1) previously have been shown to have protective effects on mitochondrial function. To examine the potential mechanisms involved in protection against mitochondrial failure, we have studied the effects of the dimer of 16,16-diMe-PGB1 (dicalciphor) on mitochondrial function in hepatocytes exposed to KCN. Addition of micromolar concentrations of dicalciphor provided substantial protection against KCN-induced toxicity in a concentration- and time-dependent manner. Dicalciphor, however, had no effect on total or mitochondrial ATP losses in KCN-treated cells. The dimer prevented the marked loss of mitochondrial membrane potential (delta psi) and delta pH that occurs as a result of KCN treatment and prevented KCN-induced loading of phosphate in mitochondria. Furthermore, the dimer of 16,16-diMePGB1 also prevented KCN-induced mitochondrial and cellular swelling. These results demonstrate that dicalciphor protects against KCN-induced damage and that this protection is associated with regulation of specific mitochondrial ion transport functions.


Author(s):  
Jian Zhang ◽  
Hong-Yan Cao ◽  
Ji-Qun Wang ◽  
Guo-Dong Wu ◽  
Lin Wang

ObjectiveGraphene has been widely used for various biological and biomedical applications due to its unique physiochemical properties. This study aimed to evaluate the cardiotoxicity of graphene oxide (GO) and reduced GO (rGO) in vitro and in vivo, as well as to investigate the underlying toxicity mechanisms.MethodsGO was reduced by gamma irradiation to prepare rGO and then characterized by UV/visible light absorption spectroscopy. Rat myocardial cells (H9C2) were exposed to GO or rGO with different absorbed radiation doses. The in vitro cytotoxicity was evaluated by MTT assay, cell apoptosis assay, and lactate dehydrogenase (LDH) activity assay. The effects of GO and rGO on oxidative damage and mitochondrial membrane potential were also explored in H9C2 cells. For in vivo experiments, mice were injected with GO or rGO. The histopathological changes of heart tissues, as well as myocardial enzyme activity and lipid peroxidation indicators in heart tissues were further investigated.ResultsrGO was developed from GO following different doses of gamma irradiation. In vitro experiments in H9C2 cells showed that compared with control cells, both GO and rGO treatment inhibited cell viability, promoted cell apoptosis, and elevated the LDH release. With the increasing radiation absorbed dose, the cytotoxicity of rGO gradually increased. Notably, GO or rGO treatment increased the content of ROS and reduced the mitochondrial membrane potential in H9C2 cells. In vivo experiments also revealed that GO or rGO treatment damaged the myocardial tissues and changed the activities of several myocardial enzymes and the lipid peroxidation indicators in the myocardial tissues.ConclusionGO exhibited a lower cardiotoxicity than rGO due to the structure difference, and the cardiotoxicity of GO and rGO might be mediated by lipid peroxidation, oxidative stress, and mitochondrial dysfunction.


2013 ◽  
Vol 91 (12) ◽  
pp. 1016-1024 ◽  
Author(s):  
Jia Li ◽  
Siran Wang ◽  
Jimei Yin ◽  
Linna Pan

Geraniin has previously been reported to possess extensive biological activity. In this study, we reported that geraniin is an inhibitor of tumor activity in vitro and in vivo. Geraniin suppressed the proliferation of A549 cells in a dose- and time-dependent manner. Geraniin arrested the cell cycle in the S phase and induced a significant accumulation of reactive oxygen species (ROS), as well as an increased percentage of cells with mitochondrial membrane potential (MMP) disruption. Western blot analysis showed that geraniin inhibited Bcl-2 expression and induced Bax expression to disintegrate the outer mitochondrial membrane and cause cytochrome c release. Mitochondrial cytochrome c release was associated with the activation of caspase-9 and caspase-3 cascades. Additionally, geraniin resulted in tumor growth inhibition in A549 xenografts. Our results indicate cytotoxic activity of geraniin towards cancer cells in vitro and in vivo.


2020 ◽  
Vol 19 (9) ◽  
pp. 1835-1842
Author(s):  
Supita Tanasawet ◽  
Wanida Sukketsiri ◽  
Pennapa Chonpathompikunlert ◽  
Pennapa Chonpathompikunlert ◽  
Wanwimol Klaypradit ◽  
...  

Purpose: To investigate the anti-cancer potential of astaxanthin from Litopenaeus vannamei encapsulated in liposomes (ASX) to treat lung cancer A549 cells.Methods: Lung adenocarcinoma A549 cells were cultured and treated with ASX, following which cell viability and nuclear staining were performed. Generation of ROS was identified by the DCFH-DA assay while tetramethylrhodamine ethyl ester was used to determine the mitochondrial membrane potential. Flow cytometry was applied to investigate caspase-3/7 activity and cell cycle distribution.Results: ASX inhibited growth of A549 in a concentration- and time- dependent manner. The IC50 values at 24, 48 and 72 h were 53.73, 22.85, 17.46 μg/mL, respectively (p < 0.05). After incubation with ASX, the morphological changes were observed in A549 cells following Hoechst 33342/PI fluorescent staining. ASX increased ROS generation and was associated with the collapse of mitochondrial membrane potential, which subsequently triggered the activation of caspase-3/7 activity leading to apoptosis (p < 0.05). In addition, A549 cells accumulated in the G0/G1 phase.Conclusion: The results suggest that ASX is a valuable nutraceutical agent to target A549 lung cancer cells via ROS-dependent pathway as well as blockage of cell cycle progression. Keywords: Astaxanthin, Litopenaeus vannamei, Lung cancer, A549, Apoptosis


2017 ◽  
Vol 61 (6) ◽  
Author(s):  
Maizbha U. Ahmed ◽  
Tony Velkov ◽  
Yu-Wei Lin ◽  
Bo Yun ◽  
Cameron J. Nowell ◽  
...  

ABSTRACT Inhaled polymyxins are of considerable utility in achieving optimal exposure in the respiratory tract for the treatment of lung infections caused by multidrug-resistant Gram-negative pathogens. Current inhaled polymyxin therapy is empirical, and often large doses are used that may lead to potential pulmonary adverse effects. This study aimed to investigate the effect of polymyxins on human lung epithelial (A549) cells. The viability of A549 cells was examined after treatment with polymyxins by flow cytometry. Activation of caspases 3, 8, and 9, expression of Fas ligand (FasL), loss of mitochondrial membrane potential, and mitochondrial oxidative stress induced by polymyxin B were evaluated. The concentration of polymyxin B required to induce 50% of maximal cell death was 1.74 mM (95% confidence interval, 1.60 to 1.90 mM). Colistin was at least 2-fold less toxic than polymyxin B, while colistimethate was nontoxic. With 2.0 mM polymyxin B, 30.6% ± 11.5% (mean ± standard deviation) of the cells were apoptotic at 8 h and this increased to 71.3% ± 3.72% at 24 h. Concentration- and time-dependent activation of caspases 3, 8, and 9 was evident, while the activation of caspase 9 was more dramatic. Furthermore, polymyxin B caused concentration- and time-dependent FasL expression, production of mitochondrial reactive oxygen species, and changes in mitochondrial membrane potential. This is the first study to demonstrate that both extrinsic death receptor and intrinsic mitochondrial pathways are involved in polymyxin-induced toxicity in A549 cells. This knowledge base is critical for the development of novel strategies for the safe and effective inhalation therapy of polymyxins against Gram-negative “superbugs.”


2019 ◽  
Vol 20 (21) ◽  
pp. 5253 ◽  
Author(s):  
Arnold Sipos ◽  
Kwang-Jin Kim ◽  
Constantinos Sioutas ◽  
Edward D. Crandall

Background: Polystyrene nanoparticles (PNP) are taken up by primary rat alveolar epithelial cell monolayers (RAECM) in a time-, dose-, and size-dependent manner without involving endocytosis. Internalized PNP in RAECM activate autophagy, are delivered to lysosomes, and undergo [Ca2+]-dependent exocytosis. In this study, we explored nanoparticle (NP) interactions with A549 cells. Methods: After exposure to PNP or ambient pollution particles (PM0.2), live single A549 cells were studied using confocal laser scanning microscopy. PNP uptake and egress were investigated and activation of autophagy was confirmed by immunolabeling with LC3-II and LC3-GFP transduction/colocalization with PNP. Mitochondrial membrane potential, mitophagy, and lysosomal membrane permeability (LMP) were assessed in the presence/absence of apical nanoparticle (NP) exposure. Results: PNP uptake into A549 cells decreased in the presence of cytochalasin D, an inhibitor of macropinocytosis. PNP egress was not affected by increased cytosolic [Ca2+]. Autophagy activation was indicated by increased LC3 expression and LC3-GFP colocalization with PNP. Increased LMP was observed following PNP or PM0.2 exposure. Mitochondrial membrane potential was unchanged and mitophagy was not detected after NP exposure. Conclusions: Interactions between NP and A549 cells involve complex cellular processes leading to lysosomal dysfunction, which may provide opportunities for improved nanoparticle-based therapeutic approaches to lung cancer management.


Author(s):  
Hongtao Li ◽  
Peng Chen ◽  
Lei Chen ◽  
Xinning Wang

Background: Nuclear factor kappa B (NF-κB) is usually activated in Wilms tumor (WT) cells and plays a critical role in WT development. Objective: The study purpose was to screen a NF-κB inhibitor from natural product library and explore its effects on WT development. Methods: Luciferase assay was employed to assess the effects of natural chemical son NF-κB activity. CCK-8 assay was conducted to assess cell growth in response to naringenin. WT xenograft model was established to analyze the effect of naringenin in vivo. Quantitative real-time PCR and Western blot were performed to examine the mRNA and protein levels of relative genes, respectively. Results: Naringenin displayed significant inhibitory effect on NF-κB activation in SK-NEP-1 cells. In SK-NEP-1 and G-401 cells, naringenin inhibited p65 phosphorylation. Moreover, naringenin suppressed TNF-α-induced p65 phosphorylation in WT cells. Naringenin inhibited TLR4 expression at both mRNA and protein levels in WT cells. CCK-8 staining showed that naringenin inhibited cell growth of the two above WT cells in dose-and time-dependent manner, whereas Toll-like receptor 4 (TLR4) over expression partially reversed the above phenomena. Besides, naringenin suppressed WT tumor growth in dose-and time-dependent manner in vivo. Western blot found that naringenin inhibited TLR4 expression and p65 phosphorylation in WT xenograft tumors. Conclusion: Naringenin inhibits WT development viasuppressing TLR4/NF-κB signaling


2019 ◽  
Vol 19 (4) ◽  
pp. 557-566 ◽  
Author(s):  
Nerella S. Goud ◽  
Mahammad S. Ghouse ◽  
Jatoth Vishnu ◽  
Jakkula Pranay ◽  
Ravi Alvala ◽  
...  

Background: Human Galectin-1, a protein of lectin family showing affinity towards β-galactosides has emerged as a critical regulator of tumor progression and metastasis, by modulating diverse biological events including homotypic cell aggregation, migration, apoptosis, angiogenesis and immune escape. Therefore, galectin-1 inhibitors might represent novel therapeutic agents for cancer. Methods: A new series of heterocyclic imines linked coumarin-thiazole hybrids (6a-6r) was synthesized and evaluated for its cytotoxic potential against a panel of six human cancer cell lines namely, lung (A549), prostate (DU-145), breast (MCF-7 & MDA-MB-231), colon (HCT-15 & HT-29) using MTT assay. Characteristic apoptotic assays like DAPI staining, cell cycle, annexin V and Mitochondrial membrane potential studies were performed for the most active compound. Furthermore, Gal-1 inhibition was confirmed by ELISA and fluorescence spectroscopy. Results: Among all, compound 6g 3-(2-(2-(pyridin-2-ylmethylene) hydrazineyl) thiazol-4-yl)-2H-chromen-2- one exhibited promising growth inhibition against HCT-15 colorectal cancer cells with an IC50 value of 1.28 ± 0.14 µM. The characteristic apoptotic morphological features like chromatin condensation, membrane blebbing and apoptotic body formation were clearly observed with compound 6g on HCT-15 cells using DAPI staining studies. Further, annexin V-FITC/PI assay confirmed effective early apoptosis induction by treatment with compound 6g. Loss of mitochondrial membrane potential and enhanced ROS generation were confirmed with JC-1 and DCFDA staining method, respectively by treatment with compound 6g, suggesting a possible mechanism for inducing apoptosis. Moreover, flow cytometric analysis revealed that compound 6g blocked G0/G1 phase of the cell cycle in a dose-dependent manner. Compound 6g effectively reduced the levels of Gal-1 protein in a dose-dependent manner. The binding constant (Ka) of 6g with Gal-1 was calculated from the intercept value which was observed as 1.9 x 107 M-1 by Fluorescence spectroscopy. Molecular docking studies showed strong interactions of compound 6g with Gal-1 protein. Conclusion: Our studies demonstrate the anticancer potential and Gal-1 inhibition of heterocyclic imines linked coumarin-thiazole hybrids.


2019 ◽  
Vol 18 (4) ◽  
pp. 334-341 ◽  
Author(s):  
Kun Fu ◽  
Liqiang Chen ◽  
Lifeng Miao ◽  
Yan Guo ◽  
Wei Zhang ◽  
...  

Background/Objective: Grape seed proanthocyanidins (GSPs) are a group of polyphenolic bioflavonoids, which possess a variety of biological functions and pharmacological properties. We studied the neuroprotective effects of GSP against oxygen-glucose deprivation/reoxygenation (OGD/R) injury and the potential mechanisms in mouse neuroblastoma N2a cells. Methods: OGD/R was conducted in N2a cells. Cell viability was evaluated by CCK-8 and LDH release assay. Apoptosis was assessed by TUNEL staining and flow cytometry. Protein levels of cleaved caspase-3, Bax and Bcl-2 were detected by Western blotting. CHOP, GRP78 and caspase-12 mRNA levels were assessed by real-time PCR. JC-1 dying was used to detect mitochondrial membrane potential. ROS levels, activities of endogenous antioxidant enzymes and ATP production were examined to evaluate mitochondrial function. Results: GSP increased cell viability after OGD/R injury in a dose-dependent manner. Furthermore, GSP inhibited cell apoptosis, reduced the mRNA levels of CHOP, GRP78 and caspase-12 (ER stressassociated genes), restored mitochondrial membrane potential and ATP generation, improved activities of endogenous anti-oxidant ability (T-AOC, GXH-Px, and SOD), and decreased ROS level. Conclusion: Our findings suggest that GSP can protect N2a cells from OGD/R insult. The mechanism of anti-apoptotic effects of GSP may involve attenuating ER stress and mitochondrial dysfunction.


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