scholarly journals Evidence for Nanoparticle-Induced Lysosomal Dysfunction in Lung Adenocarcinoma (A549) Cells

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.

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


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.


Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1515
Author(s):  
Xiukun Xue ◽  
Yanjuan Wu ◽  
Xiao Xu ◽  
Ben Xu ◽  
Zhaowei Chen ◽  
...  

Polymeric prodrugs, synthesized by conjugating chemotherapeutic agents to functional polymers, have been extensively investigated and employed for safer and more efficacious cancer therapy. By rational design, a pH and reduction dual-sensitive dextran-di-drugs conjugate (oDex-g-Pt+DOX) was synthesized by the covalent conjugation of Pt (IV) prodrug and doxorubicin (DOX) to an oxidized dextran (oDex). Pt (IV) prodrug and DOX were linked by the versatile efficient esterification reactions and Schiff base reaction, respectively. oDex-g-Pt+DOX could self-assemble into nanoparticles with an average diameter at around 180 nm. The acidic and reductive (GSH) environment induced degradation and drug release behavior of the resulting nanoparticles (oDex-g-Pt+DOX NPs) were systematically investigated by optical experiment, DLS analysis, TEM measurement, and in vitro drugs release experiment. Effective cellular uptake of the oDex-g-Pt+DOX NPs was identified by the human cervical carcinoma HeLa cells via confocal laser scanning microscopy. Furthermore, oDex-g-Pt+DOX NPs displayed a comparable antiproliferative activity than the simple combination of free cisplatin and DOX (Cis+DOX) as the extension of time. More importantly, oDex-g-Pt+DOX NPs exhibited remarkable reversal ability of tumor resistance compared to the cisplatin in cisplatin-resistant lung carcinoma A549 cells. Take advantage of the acidic and reductive microenvironment of tumors, this smart polymer-dual-drugs conjugate could serve as a promising and effective nanomedicine for combination chemotherapy.


1998 ◽  
Vol 330 (2) ◽  
pp. 853-860 ◽  
Author(s):  
N. J. Silvia MORENO ◽  
Li ZHONG ◽  
Hong-Gang LU ◽  
Wanderley DE SOUZA ◽  
Marlene BENCHIMOL

Cytoplasmic pH (pHi) regulation was studied in Toxoplasma gondii tachyzoites by using the fluorescent dye 2ʹ,7ʹ-bis-(2-carboxyethyl)-5(6)-carboxyfluorescein. Their mean baseline pHi (7.07±0.06; n = 5) was not significantly affected in the absence of extracellular Na+, K+ or HCO3- but was significantly decreased in a dose-dependent manner by low concentrations of N,Nʹ-dicyclohexylcarbodi-imide (DCCD), N-ethylmaleimide (NEM) or bafilomycin A1. Bafilomycin A1 also inhibited the recovery of tachyzoite pHi after an acid load with sodium propionate. Similar concentrations of DCCD, NEM and bafilomycin A1 produced depolarization of the plasma membrane potential as measured with bis-(1,3-diethylthiobarbituric)trimethineoxonol (bisoxonol), and DCCD prevented the hyperpolarization that accompanies acid extrusion after the addition of propionate, in agreement with the electrogenic nature of this pump. Confocal laser scanning microscopy indicated that, in addition to being located in cytoplasmic vacuoles, the vacuolar (V)-H+-ATPase of T. gondii tachyzoites is also located in the plasma membrane. Surface localization of the V-H+-ATPase was confirmed by experiments using biotinylation of cell surface proteins and immunoprecipitation with antibodies against V-H+-ATPases. Taken together, the results are consistent with the presence of a functional V-H+-ATPase in the plasma membrane of these intracellular parasites and with an important role of this enzyme in the regulation of pHi homoeostasis in these cells.


2010 ◽  
Vol 59 (10) ◽  
pp. 1225-1234 ◽  
Author(s):  
H. M. H. N. Bandara ◽  
O. L. T. Lam ◽  
R. M. Watt ◽  
L. J. Jin ◽  
L. P. Samaranayake

The objective of this study was to evaluate the effect of the bacterial endotoxin LPS on Candida biofilm formation in vitro. The effect of the LPS of Pseudomonas aeruginosa, Klebsiella pneumoniae, Serratia marcescens and Salmonella typhimurium on six different species of Candida, comprising Candida albicans ATCC 90028, Candida glabrata ATCC 90030, Candida krusei ATCC 6258, Candida tropicalis ATCC 13803, Candida parapsilosis ATCC 22019 and Candida dubliniensis MYA 646, was studied using a standard biofilm assay. The metabolic activity of in vitro Candida biofilms treated with LPS at 90 min, 24 h and 48 h was quantified by XTT reduction assay. Viable biofilm-forming cells were qualitatively analysed using confocal laser scanning microscopy (CLSM), while scanning electron microscopy (SEM) was employed to visualize the biofilm structure. Initially, adhesion of C. albicans was significantly stimulated by Pseudomonas and Klebsiella LPS. A significant inhibition of Candida adhesion was noted for the following combinations: C. glabrata with Pseudomonas LPS, C. tropicalis with Serratia LPS, and C. glabrata, C. parapsilosis or C. dubliniensis with Salmonella LPS (P<0.05). After 24 h of incubation, a significant stimulation of initial colonization was noted for the following combinations: C. albicans/C. glabrata with Klebsiella LPS, C. glabrata/C. tropicalis/C. krusei with Salmonella LPS. In contrast, a significant inhibition of biofilm formation was observed in C. glabrata/C. dubliniensis/C. krusei with Pseudomonas LPS, C. krusei with Serratia LPS, C. dubliniensis with Klebsiella LPS and C. parapsilosis/C. dubliniensis /C. krusei with Salmonella LPS (P<0.05). On further incubation for 48 h, a significant enhancement of biofilm maturation was noted for the following combinations: C. glabrata/C. tropicalis with Serratia LPS, C. dubliniensis with Klebsiella LPS and C. glabrata with Salmonella LPS, and a significant retardation was noted for C. parapsilosis/C. dubliniensis/C. krusei with Pseudomonas LPS, C. tropicalis with Serratia LPS, C. glabrata/C. parapsilosis/C. dubliniensis with Klebsiella LPS and C. dubliniensis with Salmonella LPS (P<0.05). These findings were confirmed by SEM and CLSM analyses. In general, the inhibition of the biofilm development of LPS-treated Candida spp. was accompanied by a scanty architecture with a reduced numbers of cells compared with the profuse and densely colonized control biofilms. These data are indicative that bacterial LPSs modulate in vitro Candida biofilm formation in a species-specific and time-dependent manner. The clinical and the biological relevance of these findings have yet to be explored.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Kai Zhang ◽  
Tao Peng ◽  
Qingying Yan ◽  
Leitao Sun ◽  
Haojun Miao ◽  
...  

Jiedu Sangen Decoction (JSD), a traditional Chinese medicine (TCM) formula, has been widely used in China to treat gastrointestinal cancer, especially as an adjuvant therapy in colorectal cancer (CRC) patients. This study aimed to evaluate the efficacy of JSD and Jiedu Sangen aqueous extract (JSAE) in colon cancer cells and explored the underlining mechanisms by cytotoxicity assay, scratch assay, transwell migration assay, matrigel invasion assay, confocal laser scanning microscopy, and western blot analysis. We demonstrated that JSAE inhibited the growth of colon cancer SW480 cells in a dose-dependent manner and JSAE repressed cancer cell migration and invasion. Furthermore, epithelial mesenchymal transition (EMT) was reversed by JSAE via enhancing E-cadherin expression and attenuating protein levels of EMT promoting factors such as N-cadherin, Slug, and ZEB1. These findings provided the first experimental evidence confirming the efficacy of JSAE in repressing invasion and metastasis of CRC and paving a way for the broader use of JSD in clinic.


2017 ◽  
Author(s):  
Dahong Wang ◽  
Lanlan Wei ◽  
Shuaiying Zhang

The biological activities of quinoxalone, a novel small molecular substance isolated from the broth of the myxobacterium Stigmatella eracta WXNXJ-B, was investigated. This study was designed to determine the anti-proliferative, apoptotic property of quinoxalone, using B16 mouse melanoma cells as a model system. The results showed that quinoxalone has antitumor activity and can significantly inhibit the proliferation of B16 cells. The extent and the timing of apoptosis were strongly dependent on the dose. After treating with quinoxalone and staining with Hoechst 33342, B16 cells showed typical apoptotic morphological features such as chromatin condensation by fluorescent microscopy. DNA isolated from B16 cells cultured with quinoxalone showed a typical DNA ladder of apoptosis in agarose gel electrophoresis. Further investigation results showed that the apoptotic machinery of B16 induced by quinoxalone was associated with drop in mitochondrial membrane potential from 5.35% to 23.7%, up-regulation of Bax and down-regulation of Bcl-2 in a dose-dependent manner. And a significant increased activation of caspase-3. Our finding suggests that quinoxalone could suppress the growth of B16 cells and reduces cell survival via disturbing mitochondrial membrane potential and inducing apoptosis of tumor cells.


2021 ◽  
Author(s):  
Zhuang Ma ◽  
Zuheng Liu ◽  
Yuting Xue ◽  
Hao Zhang ◽  
Wenjun Xiong ◽  
...  

Abstract Background: Both mitochondrial quality control and energy metabolism are critical in maintaining the physiological function of cardiomyocytes. Previous studies indicated that PGC-1α is a transcription co-activator in promoting mitochondrial energy metabolism which would be beneficial for cardiomyocytes. However, PGC-1α overexpression in heart tissues could also result in the development of cardiomyopathy. This discrepancy in vivo and in vitro might be due to neglecting the elimination of damaged mitochondrial. Thus, an integration strategy of mitochondrial biogenesis and mitophagy might be beneficial.Methods: We studied the function of PINK1 in mitophagy in isoproterenol (Iso)-induced cardiomyocyte injury. Adenovirus was used to provoke an overexpression of the PINK1/Mfn2 protein. Mitochondrial morphology was examined via electron microscopy and confocal microscopy. Cardiomyocytes injury were measured by mitochondrial membrane potential (MMP), reactive oxygen species (ROS) and apoptosis. Metformin was used to increase mitochondrial biogenesis, the level of which was detected via immunoblotting. Additionally, mitochondrial respiratory function was measured by ATP production and oxygen consumption rate (OCR). Results: Cardiomyocytes treated with Iso had high levels of PINK1 and low levels of Mfn2 in a time-dependent manner. PINK1 overexpression promoted mitophagy, alleviated Iso-induced reduction in MMP, reduced ROS production and the apoptotic rate. In addition to increasing mitophagy, metformin could promote mitochondrial biogenensis and the overexpression of Mfn2 induce mitochondrial fusion. Moreover, metformin treatment and PINK1/Mfn2 overexpression reduced the mitochondrial dysfunction by inhibiting the generation of ROS, and leading to an increase in both ATP production and mitochondrial membrane potential in Iso-induced cardiomyocytes injury. Conclusion: Our findings indicate that a combination strategy may help ameliorate myocardial injury through mitophagy and mitochondrial biogenesis.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Shaoe Zhang ◽  
Xiao Wang ◽  
Xiaotao Shi ◽  
Honglue Tan ◽  
Himanshu Garg

Background. External socking and washing with the Chinese herbal Sanhuang Jiedu decoction (SHJD) can effectively control local limb infections with bone and implant exposure. However, the antibiofilm activities of this decoction in vitro have not yet been investigated. Therefore, the aim of this study was to examine the effects and characteristics of SHJD on the mature biofilms of multidrug-resistant staphylococci on a titanium surface. Methods. Biofilm-forming methicillin-resistant Staphylococcus epidermidis ATCC 35984 and S. aureus ATCC 43330, and non-biofilm-forming S. epidermidis ATCC 12228 were selected as the experimental strains. The mature biofilms were prepared on titanium surfaces. The five experimental groups were based on dilution concentrations (DC) of SHJD: the control group (biofilm incubated with 0.85% NaCl solution), the SHJD (DC:1/8) group (initial SHJD solution was diluted 1/8), the SHJD (DC:1/4) group, the SHJD (DC:1/2) group, and the SHJD (DC:1/1) group (initial SHJD solution). The effects of SHJD on the mature biofilms were observed with the bacterial spread plate method, crystal violet (CV) staining, scanning electron microscopy, and confocal laser scanning microscopy. Results. After culture in tryptic soy broth for 72 h, ATCC 43300 and ATCC 35984 produced mature biofilms and ATCC 12228 did not. The optical density value of ATCC 12228 was 0.11 ± 0.02 , significantly lower than that of ATCC 35984 ( 0.42 ± 0.05 ) or ATCC 43300 ( 0.41 ± 0.03 ) ( P < 0.05 ). The mature biofilms of ATCC 43300 and ATCC 35984 clearly disintegrated when incubated for 12–24 h with SHJD (DC:1/1) or SHJD (DC:1/2), showing only scattered bacterial adhesion. In the SHJD (DC:1/4) group, although many residual bacterial colonies still clustered together, presenting a biofilm structure, it was very looser than that in the SHJD (DC:1/8) group in which the biofilm was similar to that in the control group. For ATCC 12228, only colony adhesion was observed, and the number of colonies decreased as the concentration of SHJD or the culture period increased. The quantitative results for the bacterial spread plate and CV staining showed significant differences between the SHJD groups ( P < 0.05 ). Conclusion. SHJD has antibiofilm activity against multidrug-resistant Staphylococcus strains. It weakens or disrupts already-formed mature biofilms on titanium surfaces in a concentration- and incubation time-dependent manner.


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