scholarly journals Calpain activation and disturbance of autophagy are induced in cortical neurons in vitro by exposure to HA/β-Ga2O3:Cr3+ nanoparticles

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4365 ◽  
Author(s):  
Yu Lei ◽  
Chengkun Wang ◽  
Quan Jiang ◽  
Xiaoyi Sun ◽  
Yongzhong Du ◽  
...  

The toxicity of engineered nanoparticles remains a concern. The knowledge of biohazards associated with particular nanoparticles is crucial to make this cutting-edge technology more beneficial and safe. Here, we evaluated the toxicity of Ga2O3 nanoparticles (NPs), which are frequently used to enhance the performance of metal catalysts in a variety of catalytic reactions. The potential inflammatory signaling associated with the toxicity of HA/β-Ga2O3:Cr3+ NPs in primary cortical neurons was examined. We observed a dose-dependent decrease in cell viability and an increase in apoptosis in neurons following various concentrations (0, 1, 5, 25, 50, 100 µg/ml) of HA/β-Ga2O3:Cr3+ NPs treatment. Consistently, constitutively active forms of calcineurin (48 kDa) were significantly elevated in cultured primary cortical neurons, which was consistent with calpain activation indicated by the breakdown products of spectrin. Moreover, HA/β-Ga2O3:Cr3+ NPs result in the elevation of LC3-II formation, SQSTM/p62, and Cathepsin B, whereas phosphorylation of CaMKII (Thr286) and Synapsin I (Ser603) were downregulated in the same context. Taken together, these results demonstrate for the first time that calpain activation and a disturbance of autophagy signaling are evoked by exposure to HA/β-Ga2O3:Cr3+ NPs, which may contribute to neuronal injury in vitro.

2015 ◽  
Vol 43 (05) ◽  
pp. 915-925 ◽  
Author(s):  
Shou-Lun Lee ◽  
Hsien-Kuang Lee ◽  
Ting-Yu Chin ◽  
Ssu-Chieh Tu ◽  
Ming-Hsun Kuo ◽  
...  

Purple sweet potato leaves (PSPLs) are healthy vegetable that is rich in anti-oxidants. A solution of boiling water extract of PSPL (PSPLE) is believed to be able to prevent obesity and metabolic syndrome in the countryside of Taiwan, but its efficacy has not yet been verified. The purpose of this study was to investigate the possible anti-adipogenesis effect of PSPLE in vitro. PSPLE was used to treat the 3T3-L1 cells, and the effects on cell proliferation and adipogenesis were investigated. The results showed that PSPLE caused a dose-dependent decrease in the cell proliferation of 3T3-L1 preadipocytes, but did not alter the cell viability. In addition, PSPLE induced ERK inactivation in the 3T3-L1 preadipocytes. Furthermore, pre-treatment of confluent 3T3-L1 cells with PSPLE led to reduced lipid accumulation in differentiated 3T3-L1 cells. The inhibition of lipogenesis could result from the PSPLE-induced down-regulation of the expression of the C/EBPα and SREBP-1 transcription factors during 3T3-L1 adipocyte differentiation. These results suggest that PSPLE not only inhibits cell proliferation at an early stage but also inhibits adipogenesis at a later stage of the differentiation program.


2016 ◽  
Vol 2016 ◽  
pp. 1-17 ◽  
Author(s):  
Larissa Dyugovskaya ◽  
Slava Berger ◽  
Andrey Polyakov ◽  
Peretz Lavie ◽  
Lena Lavie

Previously we identified, for the first time, a new small-size subset of neutrophil-derived giant phagocytes (Gϕ) which spontaneously developin vitrowithout additional growth factors or cytokines. Gϕare CD66b+/CD63+/MPO+/LC3B+and are characterized by extended lifespan, large phagolysosomes, active phagocytosis, and reactive oxygen species (ROS) production, and autophagy largely controls their formation. Hypoxia, and particularly hypoxia/reoxygenation, is a prominent feature of many pathological processes. Herein we investigated Gϕformation by applying various hypoxic conditions. Chronic intermittent hypoxia (IH) (29 cycles/day for 5 days) completely abolished Gϕformation, while acute IH had dose-dependent effects. Exposure to 24 h (56 IH cycles) decreased their size, yield, phagocytic ability, autophagy, mitophagy, and gp91-phox/p22-phoxexpression, whereas under 24 h sustained hypoxia (SH) the size and expression of LC3B and gp91-phox/p22-phoxresembled Gϕformed in normoxia. Diphenyl iodide (DPI), a NADPH oxidase inhibitor, as well as the PI3K/Akt and autophagy inhibitor LY294002 abolished Gϕformation at all oxygen conditions. However, the potent antioxidant, N-acetylcysteine (NAC) abrogated the effects of IH by inducing large CD66b+/LC3B+Gϕand increased both NADPH oxidase expression and phagocytosis. These findings suggest that NADPH oxidase, autophagy, and the PI3K/Akt pathway are involved in Gϕdevelopment.


BIO-PROTOCOL ◽  
2017 ◽  
Vol 7 (16) ◽  
Author(s):  
Julia Alterman ◽  
Andrew Coles ◽  
Lauren Hall ◽  
Neil Aronin ◽  
Anastasia Khvorova ◽  
...  

Toxins ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 494 ◽  
Author(s):  
Jan Lubawy ◽  
Arkadiusz Urbański ◽  
Lucyna Mrówczyńska ◽  
Eliza Matuszewska ◽  
Agata Światły-Błaszkiewicz ◽  
...  

Melittin (MEL) is a basic polypeptide originally purified from honeybee venom. MEL exhibits a broad spectrum of biological activity. However, almost all studies on MEL activity have been carried out on vertebrate models or cell lines. Recently, due to cheap breeding and the possibility of extrapolating the results of the research to vertebrates, insects have been used for various bioassays and comparative physiological studies. For these reasons, it is valuable to examine the influence of melittin on insect physiology. Here, for the first time, we report the immunotropic and cardiotropic effects of melittin on the beetle Tenebrio molitor as a model insect. After melittin injection at 10−7 M and 10−3 M, the number of apoptotic cells in the haemolymph increased in a dose-dependent manner. The pro-apoptotic action of MEL was likely compensated by increasing the total number of haemocytes. However, the injection of MEL did not cause any changes in the percent of phagocytic haemocytes or in the phenoloxidase activity. In an in vitro bioassay with a semi-isolated Tenebrio heart, MEL induced a slight chronotropic-positive effect only at a higher concentration (10−4 M). Preliminary results indicated that melittin exerts pleiotropic effects on the functioning of the immune system and the endogenous contractile activity of the heart. Some of the induced responses in T. molitor resemble the reactions observed in vertebrate models. Therefore, the T. molitor beetle may be a convenient invertebrate model organism for comparative physiological studies and for the identification of new properties and mechanisms of action of melittin and related compounds.


2013 ◽  
Vol 7 (8) ◽  
pp. 656-664 ◽  
Author(s):  
Ying-Ying Huang ◽  
Kazuya Nagata ◽  
Clark E Tedford ◽  
Michael R. Hamblin

2013 ◽  
Vol 31 (3) ◽  
pp. 670-683 ◽  
Author(s):  
Juliette Janson ◽  
Susanna Eketjäll ◽  
Karin Tunblad ◽  
Fredrik Jeppsson ◽  
Stefan Von Berg ◽  
...  

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Katharina Leitmeyer ◽  
Andrea Glutz ◽  
Cristian Setz ◽  
Leonie Wieland ◽  
Sulamith Egloff ◽  
...  

Statins are inhibitors of the 3-hydroxy-3-methylglutaryl-coenzyme A reductase, an enzyme necessary for the production of mevalonate. They are widely used as cholesterol-lowering drugs. However, conflicting data about the effect of statins on neuronal cells has been published. To explore the effect of simvastatin on spiral ganglion neurons (SGNs), SG explants of 5-day-old rats were treated with increasing concentrations of simvastatin. In addition, SG explants were treated with mevalonate and with the combination of simvastatin and mevalonate. SGN number, length of the neurites, area of nonneuronal supporting cells, and neuronal survival were analyzed. Simvastatin treatment results in a significant dose-dependent decrease of SG neurite number, length of neurites, area of supporting cells, and SG neuronal survival compared to control. Interestingly, treatment with mevalonate in addition to simvastatin increased SG neuronal survival compared to simvastatin treatment only. However, treatment with mevalonate in addition to simvastatin did not influence SG neurite number, length of neurites, and area of supporting cells compared to simvastatin treatment only. Our results suggest a neurotoxic effect of simvastatin on SGNsin vitro. Neurotoxicity seems to be at least partially mediated by the mevalonate pathway. Therefore, caution is warranted to use simvastatin as a potential otoprotective drug.


2009 ◽  
Vol 77 (9) ◽  
pp. 4092-4101 ◽  
Author(s):  
Monica L. Vieira ◽  
Silvio A. Vasconcellos ◽  
Amane P. Gonçales ◽  
Zenaide M. de Morais ◽  
Ana L. T. O. Nascimento

ABSTRACT Pathogenic Leptospira species are the etiological agents of leptospirosis, a widespread disease of human and veterinary concern. In this study, we report that Leptospira species are capable of binding plasminogen (PLG) in vitro. The binding to the leptospiral surface was demonstrated by indirect immunofluorescence confocal microscopy with living bacteria. The PLG binding to the bacteria seems to occur via lysine residues because the ligation is inhibited by addition of the lysine analog 6-aminocaproic acid. Exogenously provided urokinase-type PLG activator (uPA) converts surface-bound PLG into enzymatically active plasmin, as evaluated by the reaction with the chromogenic plasmin substrate d-Val-Leu-Lys 4-nitroanilide dihydrochloridein. The PLG activation system on the surface of Leptospira is PLG dose dependent and does not cause injury to the organism, as cellular growth in culture was not impaired. The generation of active plasmin within Leptospira was observed with several nonvirulent high-passage strains and with the nonpathogenic saprophytic organism Leptospira biflexa. Statistically significant higher activation of plasmin was detected with a low-passage infectious strain of Leptospira. Plasmin-coated virulent Leptospira interrogans bacteria were capable of degrading purified extracellular matrix fibronectin. The breakdown of fibronectin was not observed with untreated bacteria. Our data provide for the first time in vitro evidence for the generation of active plasmin on the surface of Leptospira, a step that may contribute to leptospiral invasiveness.


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