scholarly journals Astrocytes Exhibit a Protective Role in Neuronal Firing Patterns under Chemically Induced Seizures in Neuron–Astrocyte Co-Cultures

2021 ◽  
Vol 22 (23) ◽  
pp. 12770
Author(s):  
Annika Ahtiainen ◽  
Barbara Genocchi ◽  
Jarno M. A. Tanskanen ◽  
Michael T. Barros ◽  
Jari A. K. Hyttinen ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Microelectrode Arrays ◽  
Cell Types ◽  
Protective Role ◽  
Neuronal Firing ◽  
Neuronal Homeostasis ◽  
Chemically Induced ◽  
Rat Cortical Neurons

Astrocytes and neurons respond to each other by releasing transmitters, such as γ-aminobutyric acid (GABA) and glutamate, that modulate the synaptic transmission and electrochemical behavior of both cell types. Astrocytes also maintain neuronal homeostasis by clearing neurotransmitters from the extracellular space. These astrocytic actions are altered in diseases involving malfunction of neurons, e.g., in epilepsy, Alzheimer’s disease, and Parkinson’s disease. Convulsant drugs such as 4-aminopyridine (4-AP) and gabazine are commonly used to study epilepsy in vitro. In this study, we aim to assess the modulatory roles of astrocytes during epileptic-like conditions and in compensating drug-elicited hyperactivity. We plated rat cortical neurons and astrocytes with different ratios on microelectrode arrays, induced seizures with 4-AP and gabazine, and recorded the evoked neuronal activity. Our results indicated that astrocytes effectively counteracted the effect of 4-AP during stimulation. Gabazine, instead, induced neuronal hyperactivity and synchronicity in all cultures. Furthermore, our results showed that the response time to the drugs increased with an increasing number of astrocytes in the co-cultures. To the best of our knowledge, our study is the first that shows the critical modulatory role of astrocytes in 4-AP and gabazine-induced discharges and highlights the importance of considering different proportions of cells in the cultures.

scholarly journals Comparative AAV-eGFP Transgene Expression Using Vector Serotypes 1–9, 7m8, and 8b in Human Pluripotent Stem Cells, RPEs, and Human and Rat Cortical Neurons

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Thu T. Duong ◽  
James Lim ◽  
Vidyullatha Vasireddy ◽  
Tyler Papp ◽  
Hung Nguyen ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Transgene Expression ◽  
Fluorescent Protein ◽  
Ex Vivo ◽  
Cell Types ◽  
Egfp Expression ◽  
Cell Type ◽  
Egfp Gene ◽  
Rat Cortical Neurons

Recombinant adeno-associated virus (rAAV), produced from a nonpathogenic parvovirus, has become an increasing popular vector for gene therapy applications in human clinical trials. However, transduction and transgene expression of rAAVs can differ acrossin vitroand ex vivo cellular transduction strategies. This study compared 11 rAAV serotypes, carrying one reporter transgene cassette containing a cytomegalovirus immediate-early enhancer (eCMV) and chicken beta actin (CBA) promoter driving the expression of an enhanced green-fluorescent protein (eGFP) gene, which was transduced into four different cell types: human iPSC, iPSC-derived RPE, iPSC-derived cortical, and dissociated embryonic day 18 rat cortical neurons. Each cell type was exposed to three multiplicity of infections (MOI: 1E4, 1E5, and 1E6 vg/cell). After 24, 48, 72, and 96 h posttransduction, GFP-expressing cells were examined and compared across dosage, time, and cell type. Retinal pigmented epithelium showed highest AAV-eGFP expression and iPSC cortical the lowest. At an MOI of 1E6 vg/cell, all serotypes show measurable levels of AAV-eGFP expression; moreover, AAV7m8 and AAV6 perform best across MOI and cell type. We conclude that serotype tropism is not only capsid dependent but also cell type plays a significant role in transgene expression dynamics.

scholarly journals Nckβ Adapter Controls Neuritogenesis by Maintaining the Cellular Paxillin Level

2007 ◽  
Vol 27 (17) ◽  
pp. 6001-6011 ◽  
Author(s):  
Shengxi Guan ◽  
Mei Chen ◽  
David Woodley ◽  
Wei Li
Keyword(s):  
Pc12 Cells ◽  
Cortical Neurons ◽  
State Level ◽  
Cell Types ◽  
Steady State Level ◽  
Down Regulation ◽  
Evolutionarily Conserved ◽  
Rat Cortical Neurons ◽  
Interfering Rna

ABSTRACT The SH2/SH3 adapter Nck has an evolutionarily conserved role in neurons, linking the cell surface signals to actin cytoskeleton-mediated responses. The mechanism, however, remains poorly understood. We have investigated the role of Nck/Nckα/Nck1 versus Grb4/Nckβ/Nck2 side-by-side in the process of mammalian neuritogenesis. Here we show that permanent genetic silencing of Nckβ, but not Nckα, completely blocked nerve growth factor-induced neurite outgrowth in PC12 cells and dramatically disrupted the axon and dendrite tree in primary rat cortical neurons. By screening for changes among the components reportedly present in complex with Nck, we found that the steady-state level of paxillin was significantly reduced in Nckβ knockdown, but not Nckα knockdown, neurons. Interestingly, Nckβ knockdown did not affect the paxillin level in glial cells and several other cell types of various tissue origins. Genetic silencing of paxillin blocked neuritogenesis, just like Nckβ knockdown. Reintroducing a nondegradable Nckβ into Nckβ short interfering RNA-expressing PC12 cells rescued paxillin from down-regulation and allowed the resumption of neuritogenesis. Forced expression of paxillin in Nckβ knockdown PC12 also rescued its capacity for neuritogenesis. Finally, Nckβ, but not Nckα, binds strongly to paxillin and treatment of the neurons with proteosome inhibitors prevented paxillin down-regulation in Nckβ knockdown neurons. Thus, Nckβ maintains paxillin stability during neuritogenesis.

scholarly journals Regulation of aryl hydrocarbon receptor activity in porcine cumulus–oocyte complexes in physiological and toxicological conditions: the role of follicular fluid

Reproduction ◽  
2007 ◽  
Vol 133 (5) ◽  
pp. 887-897 ◽  
Author(s):  
Daniela Nestler ◽  
Michaela Risch ◽  
Bernd Fischer ◽  
Paola Pocar
Keyword(s):  
Follicular Fluid ◽  
Cumulus Cells ◽  
Cell Types ◽  
Protective Role ◽  
Cytochrome P450 1A1 ◽  
Aryl Hydrocarbon ◽  
Arylhydrocarbon Receptor ◽  
Aryl Hydrocarbon Receptor Activity

The arylhydrocarbon receptor (AhR) mediates the adverse effects of dioxin-like compounds. However, it has also been reported that the AhR may exert a role in ovarian physiology. In the present study, porcine cumulus–oocyte complexes (COCs) were matured in vitro in the presence of 10% follicular fluid. Expression of AhR and its partner, AhR nuclear translocator occurs in immature COCs. After in vitro maturation (IVM), an up-regulation of AhR and cytochrome P450 1A1 (CYP1A1; the main AhR-target gene) was observed. To explore the role of the AhR during IVM, we exposed the COCs to 50 μM β-napthoflavone (βNF). The treatment induced a marked up-regulation of CYP1A1 mRNA, indicating both constitutive and inducible AhR activity. However, in contrast to what was observed in other cell types, no sign of toxicity was observed in COCs. To investigate if components of porcine follicular fluid may exert a protective role against AhR ligands, we exposed porcine COCs to βNF, in the absence of follicular fluid. In these conditions, a marked decrease in the percentage of matured oocytes, concomitant with an increase in oocyte degeneration, was observed. Furthermore, βNF increased apoptosis in cumulus cells in the absence of follicular fluid, whereas βNF has no effects when COCs were treated in the presence of porcine follicular fluid (pFF). In conclusion, these results suggest the presence of unknown endogenous AhR-ligand(s) during porcine IVM and that a dysregulation of this mechanism may result in ovotoxicity by inducing apoptosis in cumulus cells. However, this phenomenon is interrupted by the presence of follicular fluid, indicating a putative protective role for follicular fluid components against exogenous insults.

Mechanical perturbation of cultured cortical neurons reveals a stretch-induced delayed depolarization

1995 ◽  
Vol 74 (6) ◽  
pp. 2767-2773 ◽  
Author(s):  
S. J. Tavalin ◽  
E. F. Ellis ◽  
L. S. Satin
Keyword(s):  
Brain Injury ◽  
Cortical Neurons ◽  
Receptor Activation ◽  
Neuronal Firing ◽  
Neonatal Rat ◽  
Resting Membrane Potential ◽  
Cell Stretch ◽  
Cultured Cortical Neurons ◽  
Rat Cortical Neurons

1. An in vitro cellular model of injury was used to elucidate mechanisms contributing to traumatic brain injury (TBI). Neonatal rat cortical neurons cultured on a flexible silastic membrane were stretched rapidly and reversibly by a 50-ms pulse of pressurized air. 2. Sublethal cell stretch depolarized neuronal resting membrane potential by approximately 10 mV but only if cells were incubated for 1 h after injury. Stretch-induced delayed depolarization (or SIDD) returned to baseline values within 24 h. 3. SIDD was dependent on the degree of cell stretch and required neuronal firing, calcium entry, and N-methyl-D-aspartate receptor activation for its induction but not its maintainance. 4. Similarities between SIDD and TBI suggest that SIDD may play a role in brain injury.

Cannabis-like activity of Zornia latifolia Sm. detected in vitro on rat cortical neurons: major role of the flavone syzalterin

2020 ◽  
pp. 1-13
Author(s):  
Susanna Alloisio ◽  
Marco Clericuzio ◽  
Mario Nobile ◽  
Annalisa Salis ◽  
Gianluca Damonte ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Rat Cortical Neurons

scholarly journals High current optogenetic channels for stimulation and inhibition of primary rat cortical neurons

2017 ◽  
Author(s):  
Lei Jin ◽  
Eike Frank Joest ◽  
Wenfang Li ◽  
Shiqiang Gao ◽  
Andreas Offenhäusser ◽  
...  
Keyword(s):  
Neural Development ◽  
Cortical Neurons ◽  
Single Channel ◽  
Chloride Concentration ◽  
Neuronal Firing ◽  
High Current ◽  
Neuronal Inhibition ◽  
Rat Cortical Neurons

AbstractChR2-XXL and GtACR1 are currently the cation and anion ends of the optogenetic single channel current range. These were used in primary rat cortical neurons in vitro to manipulate neuronal firing patterns. ChR2-XXL provides high cation currents via elevated light sensitivity and a prolonged open state. Stimulating ChR2-XXL expressing putative presynaptic neurons induced neurotransmission. Moreover, stable depolarisation block could be generated in single neurons using ChR2-XXL, proving that ChR2-XXL is a promising candidate for in vivo applications of optogenetics, for example to treat peripheral neuropathic pain. We also addressed an anion channelrhodopsin (GtACR1) for the next generation of optogenetic neuronal inhibition in primary rat cortical neurons. GtACR1‘s light-gated chloride conduction was verified in primary neurons and the efficient photoinhibition of action potentials, including spontaneous activity, was shown. Our data also implies that the chloride concentration in neurons decreases during neural development. In both cases, we find surprising applications of these high current channels. For ChR2-XXL inhibition and stimulation are possible, while for GtACR1 the role of Cl−during neural development becomes a new optogenetic target.

scholarly journals Desensitization of NMDA receptors depends of their association with plasma membrane sodium-calcium exchangers in lipid nanoclasters

2018 ◽  
Author(s):  
Dmitry A. Sibarov ◽  
Ekaterina E. Poguzhelskaya ◽  
Sergei M. Antonov
Keyword(s):  
Plasma Membrane ◽  
Steady State ◽  
Cortical Neurons ◽  
External Solution ◽  
Membrane Lipid ◽  
Before And After ◽  
Rat Cortical Neurons ◽  
Amplitude Decrease

AbstractThe plasma membrane Na+/Ca2+-exchanger (NCX) has recently been shown to regulate Ca2+-dependent N-methyl-d-aspartate receptor (NMDAR) desensitization, suggesting tight interaction of NCXs and NMDARs in lipid nanoclaster or “rafts”. To evaluate possible role of this interaction we studied effects of Li+ on NMDA-elicited whole-cell currents and Ca2+ responses of rat cortical neurons in vitro before and after cholesterol extraction by methyl-β-cyclodextrin (MβCD). Substitution Li+ for Na+ in the external solution caused a concentration-dependent decrease of steady-state NMDAR currents from 440 ± 71 pA to 111 ± 29 pA in 140 mM Na+ and 140 mM Li+, respectively. Li+ inhibition of NMDAR currents disappeared in the absence of Ca2+ in the external solution (Ca2+-free), suggesting that Li+ enhanced Ca2+-dependent NMDAR desensitization. Whereas the cholesterol extraction with MβCD induced NMDAR current decrease to 136 ± 32 pA in 140 mM Na+ and 46 ± 15 pA in 140 mM Li+, the IC50 values for the Li+ inhibition were similar (about 44 mM Li+) before and after this procedure. In Ca2+-free Na+ solution steady-state NMDAR currents after the cholesterol extraction were 47 ± 6 % of control currents. Apparently this amplitude decrease was not Ca2+-dependent. In 1 mM Ca2+ Na+ solution the Ca2+-dependent NMDAR desensitization was greater when cholesterol was extracted. Obviously, this procedure promoted its development. In agreement, Li+ and KB-R7943, an inhibitor of NCX, both considerably reduced NMDAR-mediated Ca2+ responses. The cholesterol extraction itself caused a decrease of NMDAR-mediated Ca2+ responses and, in addition, abolished the effects of Li+ and KB-R7943. Taken together our data suggest that NCXs downregulate the Ca2+-dependent NMDAR desensitization. Most likely, this is determined by co-localization and tight functional interaction of NCX and NMDAR molecules in membrane lipid rafts. Their destruction is accompanied by an enhancement of NMDAR desensitization and a loss of NCX-selective agent effects on NMDARs.

Role of the 807 C/T Polymorphism of the α2 Gene in Platelet GP Ia Collagen Receptor Expression and Function

1999 ◽  
Vol 81 (06) ◽  
pp. 951-956 ◽  
Author(s):  
J. Corral ◽  
R. González-Conejero ◽  
J. Rivera ◽  
F. Ortuño ◽  
P. Aparicio ◽  
...  
Keyword(s):  
Venous Thrombosis ◽  
Cell Types ◽  
Receptor Expression ◽  
Case Control Studies ◽  
Platelet Surface ◽  
Vitro Analysis ◽  
And Function ◽  
In Vitro Analysis

SummaryThe variability of the platelet GP Ia/IIa density has been associated with the 807 C/T polymorphism (Phe 224) of the GP Ia gene in American Caucasian population. We have investigated the genotype and allelic frequencies of this polymorphism in Spanish Caucasians. The T allele was found in 35% of the 284 blood donors analyzed. We confirmed in 159 healthy subjects a significant association between the 807 C/T polymorphism and the platelet GP Ia density. The T allele correlated with high number of GP Ia molecules on platelet surface. In addition, we observed a similar association of this polymorphism with the expression of this protein in other blood cell types. The platelet responsiveness to collagen was determined by “in vitro” analysis of the platelet activation and aggregation response. We found no significant differences in these functional platelet parameters according to the 807 C/T genotype. Finally, results from 3 case/control studies involving 302 consecutive patients (101 with coronary heart disease, 104 with cerebrovascular disease and 97 with deep venous thrombosis) determined that the 807 C/T polymorphism of the GP Ia gene does not represent a risk factor for arterial or venous thrombosis.

scholarly journals Emerging Roles for Browning of White Adipose Tissue in Prostate Cancer Malignant Behaviour

2021 ◽  
Vol 22 (11) ◽  
pp. 5560
Author(s):  
Alejandro Álvarez-Artime ◽  
Belén García-Soler ◽  
Rosa María Sainz ◽  
Juan Carlos Mayo
Keyword(s):  
Prostate Cancer ◽  
Adipose Tissue ◽  
White Adipose Tissue ◽  
Tumor Development ◽  
Cell Types ◽  
Protective Role ◽  
Bioactive Molecules ◽  
Brown Adipose ◽  
Endocrine Organs

In addition to its well-known role as an energy repository, adipose tissue is one of the largest endocrine organs in the organism due to its ability to synthesize and release different bioactive molecules. Two main types of adipose tissue have been described, namely white adipose tissue (WAT) with a classical energy storage function, and brown adipose tissue (BAT) with thermogenic activity. The prostate, an exocrine gland present in the reproductive system of most mammals, is surrounded by periprostatic adipose tissue (PPAT) that contributes to maintaining glandular homeostasis in conjunction with other cell types of the microenvironment. In pathological conditions such as the development and progression of prostate cancer, adipose tissue plays a key role through paracrine and endocrine signaling. In this context, the role of WAT has been thoroughly studied. However, the influence of BAT on prostate tumor development and progression is unclear and has received much less attention. This review tries to bring an update on the role of different factors released by WAT which may participate in the initiation, progression and metastasis, as well as to compile the available information on BAT to discuss and open a new field of knowledge about the possible protective role of BAT in prostate cancer.

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