scholarly journals Extracellular electrical recording of pH-triggered bursts in C6 glioma cell populations

2016 ◽  
Vol 2 (12) ◽  
pp. e1600516 ◽  
Author(s):  
Paulo R. F. Rocha ◽  
Maria C. R. Medeiros ◽  
Ulrike Kintzel ◽  
Johannes Vogt ◽  
Inês M. Araújo ◽  
...  

Glioma patients often suffer from epileptic seizures because of the tumor’s impact on the brain physiology. Using the rat glioma cell line C6 as a model system, we performed long-term live recordings of the electrical activity of glioma populations in an ultrasensitive detection method. The transducer exploits large-area electrodes that maximize double-layer capacitance, thus increasing the sensitivity. This strategy allowed us to record glioma electrical activity. We show that although glioma cells are nonelectrogenic, they display a remarkable electrical burst activity in time. The low-frequency current noise after cell adhesion is dominated by the flow of Na+ions through voltage-gated ion channels. However, after an incubation period of many hours, the current noise markedly increased. This electric bursting phenomenon was not associated with apoptosis because the cells were viable and proliferative during the period of increased electric activity. We detected a rapid cell culture medium acidification accompanying this event. By using specific inhibitors, we showed that the electrical bursting activity was prompted by extracellular pH changes, which enhanced Na+ion flux through the psalmotoxin 1–sensitive acid-sensing ion channels. Our model of pH-triggered bursting was unambiguously supported by deliberate, external acidification of the cell culture medium. This unexpected, acidosis-driven electrical activity is likely to directly perturb, in vivo, the functionality of the healthy neuronal network in the vicinity of the tumor bulk and may contribute to seizures in glioma patients.

2005 ◽  
Vol 288 (6) ◽  
pp. E1277-E1283 ◽  
Author(s):  
Danielle A. Dufner ◽  
Ilya R. Bederman ◽  
Daniel Z. Brunengraber ◽  
Nadia Rachdaoui ◽  
Faramarz Ismail-Beigi ◽  
...  

We previously reported that 2H2O can be used to measure rates of protein synthesis during prolonged steady-state conditions (Previs SF, Fatica R, Chandramouli V, Alexander JC, Brunengraber H, and Landau BR. Am J Physiol Endocrinol Metab 286: E665-E672, 2004). The underlying premise of our method is that following the administration of 2H2O, 2H atoms in body water rapidly equilibrate with free alanine before it is incorporated into newly synthesized proteins. We have now directly examined whether 2H2O can be used to measure the influence of a single meal on protein synthesis. In addition, we have compared the use of 2H2O for measuring rates of protein synthesis in vivo vs. in cell culture. Using a rat model, we observed rapid equilibration between 2H in body water and free alanine; therefore we were able to study the response of protein synthesis to a single meal. We observed that ∼50% of the plasma albumin that is synthesized over the course of 24 h is made within ∼5 h after eating (in rats trained to eat a complete 24-h ration of food in a single meal). Contrary to what we observed in vivo, feeding (the replenishment of cell culture medium) does influence the use of 2H2O for in vitro studies. In particular, since there can be slow equilibration of 2H between water and alanine in the cell culture medium, special consideration must be made to avoid underestimating the rate of protein synthesis in vitro.


Molecules ◽  
2019 ◽  
Vol 24 (2) ◽  
pp. 326 ◽  
Author(s):  
Li Liu ◽  
Yu Dong ◽  
Xin Shan ◽  
Lin Li ◽  
Baomei Xia ◽  
...  

Baicalin (BA), a major polyphenol compound isolated from the extracts of Scutellaria radix, has been previously reported to ameliorate depressive-like behaviors in mice with chronic unpredictable mild stress (CUMS). However, its underlying antidepressant mechanisms remain unclear. This study was designed to confirm the antidepressant-like effects of BA on CUMS induced behavioral abnormalities in mice, and sought to explore the pharmacological mechanisms in vivo and in vitro. The CUMS procedure was carried out to induce depression in mice. Afterwards, the tail suspension test (TST), forced swim test (FST), and open field test (OFT) were performed within 24 h, then sucrose preference test (SPT) was conducted. Additionally, PC12 cells were pretreated with BA for 2 h, then further stimulated with corticosterone for 24 h. The levels of Interleukin-1β (IL-1β), IL-6 and Tumor Necrosis Factor-α (TNF-α) in serum, hippocampus homogenate and cell culture medium were determined using the enzyme-linked immunosorbent assay (ELISA) method. The protein expressions of inhibition of high mobility group box 1 protein (HMGB1)/Toll-like receptor 4 (TLR4)/nuclear factor kappa B (NF-κB) pathways in hippocampus and PC12 cells were detected. Our results showed that CUMS-treated mice presented notable depressive-like symptoms, such as decreased sucrose consumption, increased FST and TST immobility time. While BA (25, 50 mg/kg) significantly attenuated these changes. Besides, BA treatment considerably inhibited inflammatory cytokinesl (IL-1β, IL-6, TNF-α) levels in serum, hippocampus homogenate and cell culture medium. Western blot analysis indicated that BA inhibited the expressions of HMGB1, TLR4, and p-NF-κBp65 both in vivo and in vitro. In conclusion, the present study confirmed that BA possessed efficient antidepressant effects on depression, which was possibly related to the inhibition of HMGB1/TLR4/NF-κB pathways.


Metallomics ◽  
2015 ◽  
Vol 7 (1) ◽  
pp. 102-111 ◽  
Author(s):  
H. Haase ◽  
S. Hebel ◽  
G. Engelhardt ◽  
L. Rink

Differential speciation and lower zinc buffering by less bovine serum albumin (BSA) in cell culture medium lead to altered zinc homeostasis compared to the cellular environmentin vivo.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Andreanne G. Vasconcelos ◽  
Ana Luisa A. N. Barros ◽  
Wanessa F. Cabral ◽  
Daniel C. Moreira ◽  
Ingrid Gracielle M. da Silva ◽  
...  

Abstract Background Self-emulsifying drug delivery systems (SEDDSs) have attracted attention because of their effects on solubility and bioavailability of lipophilic compounds. Herein, a SEDDS loaded with lycopene purified from red guava (nanoLPG) was produced. The nanoemulsion was characterized using dynamic light scattering (DLS), zeta potential measurement, nanoparticle tracking analysis (NTA), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), lycopene content quantification, radical scavenging activity and colloidal stability in cell culture medium. Then, in vivo toxicity and tissue distribution in orally treated mice and cytotoxicity on human prostate carcinoma cells (DU-145) and human peripheral blood mononuclear cells (PBMC) were evaluated. Results NanoLPG exhibited physicochemical properties with a size around 200 nm, negative zeta-potential, and spherical morphology. The size, polydispersity index, and zeta potential parameters suffered insignificant alterations during the 12 month storage at 5 °C, which were associated with lycopene stability at 5 °C for 10 months. The nanoemulsion showed partial aggregation in cell culture medium at 37 °C after 24 h. NanoLPG at 0.10 mg/mL exhibited radical scavenging activity equivalent to 0.043 ± 0.002 mg Trolox/mL. The in vivo studies did not reveal any significant changes in clinical, behavioral, hematological, biochemical, and histopathological parameters in mice orally treated with nanoLPG at 10 mg/kg for 28 days. In addition, nanoLPG successfully delivered lycopene to the liver, kidney and prostate in mice, improved its cytotoxicity against DU-145 prostate cancer cells—probably by pathway independent on classical necrosis and apoptosis—and did not affect PBMC viability. Conclusions Thus, nanoLPG stands as a promising and biosafe lycopene delivery system for further development of nanotechnology-based health products. Graphical Abstract


2020 ◽  
Author(s):  
Federica Saponaro ◽  
Marco Borsò ◽  
Sara Verlotta ◽  
Lavinia Bandini ◽  
Alessandro Saba ◽  
...  

2013 ◽  
Vol 133 (5) ◽  
pp. 278-285
Author(s):  
Norimitsu Takamura ◽  
Douyan Wang ◽  
Takao Satoh ◽  
Takao Namihira ◽  
Hisato Saitoh ◽  
...  

2021 ◽  
Vol 12 ◽  
pp. 204173142110086
Author(s):  
Jun Yong Kim ◽  
Won-Kyu Rhim ◽  
Yong-In Yoo ◽  
Da-Seul Kim ◽  
Kyoung-Won Ko ◽  
...  

Exosomes derived from mesenchymal stem cells (MSCs) have been studied as vital components of regenerative medicine. Typically, various isolation methods of exosomes from cell culture medium have been developed to increase the isolation yield of exosomes. Moreover, the exosome-depletion process of serum has been considered to result in clinically active and highly purified exosomes from the cell culture medium. Our aim was to compare isolation methods, ultracentrifuge (UC)-based conventional method, and tangential flow filtration (TFF) system-based method for separation with high yield, and the bioactivity of the exosome according to the purity of MSC-derived exosome was determined by the ratio of Fetal bovine serum (FBS)-derived exosome to MSC-derived exosome depending on exosome depletion processes of FBS. The TFF-based isolation yield of exosome derived from human umbilical cord MSC (UCMSC) increased two orders (92.5 times) compared to UC-based isolation method. Moreover, by optimizing the process of depleting FBS-derived exosome, the purity of UCMSC-derived exosome, evaluated using the expression level of MSC exosome surface marker (CD73), was about 15.6 times enhanced and the concentration of low-density lipoprotein-cholesterol (LDL-c), known as impurities resulting from FBS, proved to be negligibly detected. The wound healing and angiogenic effects of highly purified UCMSC-derived exosomes were improved about 23.1% and 71.4%, respectively, with human coronary artery endothelial cells (HCAEC). It suggests that the defined MSC exosome with high yield and purity could increase regenerative activity.


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