scholarly journals Experimental Epileptogenesis in a Cell Culture Model of Primary Neurons from Rat Brain: A Temporal Multi-Scale Study

Cells ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 3004
Author(s):  
Janos Jablonski ◽  
Lucas Hoffmann ◽  
Ingmar Blümcke ◽  
Anna Fejtová ◽  
Steffen Uebe ◽  
...  
Keyword(s):  
Intracellular Signaling ◽  
Cellular Structure ◽  
Regulation Of Gene Expression ◽  
Latency Period ◽  
Neonatal Rat ◽  
Network Activity ◽  
Related Sequence ◽  
Sequence Of Events ◽  
Differentially Methylated Genes

Understanding seizure development requires an integrated knowledge of different scales of organization of epileptic networks. We developed a model of “epilepsy-in-a-dish” based on dissociated primary neuronal cells from neonatal rat hippocampus. We demonstrate how a single application of glutamate stimulated neurons to generate spontaneous synchronous spiking activity with further progression into spontaneous seizure-like events after a distinct latency period. By computational analysis, we compared the observed neuronal activity in vitro with intracranial electroencephalography (EEG) data recorded from epilepsy patients and identified strong similarities, including a related sequence of events with defined onset, progression, and termination. Next, a link between the neurophysiological changes with network composition and cellular structure down to molecular changes was established. Temporal development of epileptiform network activity correlated with increased neurite outgrowth and altered branching, increased ratio of glutamatergic over GABAergic synapses, and loss of calbindin-positive interneurons, as well as genome-wide alterations in DNA methylation. Differentially methylated genes were engaged in various cellular activities related to cellular structure, intracellular signaling, and regulation of gene expression. Our data provide evidence that a single short-term excess of glutamate is sufficient to induce a cascade of events covering different scales from molecule- to network-level, all of which jointly contribute to seizure development.

Abstract P379: Inhibition Of O-glcnac Transferase Ogt Activates P38 Signaling In Neonatal Rat Cardiomyocytes

2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
Kyriakos Papanicolaou ◽  
Natasha Zachara ◽  
Deepthi Ashok ◽  
Agnes Sidor ◽  
D B Foster ◽  
...  
Keyword(s):  
Heart Failure ◽  
Intracellular Signaling ◽  
Ventricular Myocytes ◽  
Fold Increase ◽  
Mitogen Activated Protein Kinase ◽  
Neonatal Rat ◽  
Rat Cardiomyocytes ◽  
Creb Phosphorylation ◽  
Glcnac Transferase

The mitogen activated protein kinase (MAPK) p38 is important in cardiac hypertrophic responses and p38 inhibition has been tested as a potential therapeutic approach to heart failure. p38 is tightly regulated by upstream kinases and phosphatases. While p38 inhibitors suppress cardiac hypertrophy in vitro and in animal models, the partial efficacy of p38 inhibitors in clinical trials for heart failure illustrates the need for a deeper understanding of p38-regulatory mechanisms. O -linked N-Acetylglucosamine ( O -GlcNAc) on Ser/Thr residues is a ubiquitous intracellular modification ( O -GlcNAcylation) that participates in intracellular signaling, often occurring in counterpoint to phosphorylation. O -GlcNAcylation is catalyzed by O -GlcNAc Transferase (OGT) and removed by O -GlcNAc-Ase (OGA). Given the crucial regulation of p38 activity by phosphorylation, we hypothesized that O -GlcNAcylation regulates p38 phosphorylation during basal and hypertrophic cardiomyocyte signaling. Treating neonatal rat ventricular myocytes (NRVM) with OSMI-1 (inhibitor of OGT) significantly decreased O -GlcNAcylation (0.48 ± 0.02, P <0.001 vs. vehicle), whereas treatment with Thiamet-G (inhibitor of OGA) significantly increased O -GlcNAcylation (3.0-fold increase ± 0.35, P <0.05 vs. vehicle). OSMI1 treatment induced the phosphorylation of p38 at its activation site (3.9-fold increase ± 0.46, P <0.001 vs. vehicle) and promoted the phosphorylation of the downstream target, heat shock protein Hsp27 (8-fold increase ± 1.3, P <0.0001 vs. vehicle) and transcription factor Creb (3.3-fold increase ± 0.12, P <0.001 vs. vehicle). OSMI-1 had an additive effect in inducing p38 and Creb phosphorylation following hypertrophic stimulation by phenylephrine (3.1-fold and 1.4-fold increase vs. phenylephrine respectively, P <0.05). Treatment with the p38 inhibitor SB202190 abolished the phosphorylation of Hsp27 and Creb that was induced by OSMI-1. Canonical upstream activators of p38 include the MAP3Ks, TAK1 and ASK1. However, we found that treatment with ASK1 or TAK1 inhibitors (GS-444217 and Takinib, respectively) either alone, or in combination, did not negate the phosphorylation of p38 by OSMI-1. We conclude that regulation of p38 by OGT activity could occur at a level downstream of canonical MAP3Ks or through non-canonical pathways.

NMDA Receptor-Mediated Oscillatory Activity in the Neonatal Rat Spinal Cord Is Serotonin Dependent

1998 ◽  
Vol 79 (5) ◽  
pp. 2804-2808 ◽  
Author(s):  
Jason N. Maclean ◽  
Kristine C. Cowley ◽  
Brian J. Schmidt
Keyword(s):  
Spinal Cord ◽  
Nmda Receptor ◽  
Motor Behavior ◽  
Neonatal Rat ◽  
Network Activity ◽  
Oscillatory Activity ◽  
Rat Spinal Cord ◽  
Cell Level ◽  
Receptor Antagonists

MacLean, Jason N., Kristine C. Cowley, and Brian J. Schmidt. NMDA receptor-mediated oscillatory activity in the neonatal rat spinal cord is serotonin dependent. J. Neurophysiol. 79: 2804–2808, 1998. The effect of serotonin (5-HT) receptor blockade on rhythmic network activity and on N-methyl-d-aspartate (NMDA) receptor-induced membrane voltage oscillations was examined using an in vitro neonatal rat spinal cord preparation. Pharmacologically induced rhythmic hindlimb activity, monitored via flexor and extensor electroneurograms or ventral root recordings, was abolished by 5-HT receptor antagonists. Intrinsic motoneuronal voltage oscillations, induced by NMDA in the presence of tetrodotoxin (TTX), either were abolished completely or transformed to long-lasting voltage shifts by 5-HT receptor antagonists. Conversely, 5-HT application facilitated the expression of NMDA-receptor–mediated rhythmic voltage oscillations. The results suggest that an interplay between 5-HT and NMDA receptor actions may be critical for the production of rhythmic motor behavior in the mammalian spinal cord, both at the network and single cell level.

Cytochemical Evidence for Presynatic β-Adrenergic Regulation of Secretion in the Developing Rat Submandibular Gland

1977 ◽  
Vol 35 ◽  
pp. 430-431
Author(s):  
L.S. Cutler
Keyword(s):  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Submandibular Gland ◽  
Neonatal Rat ◽  
Cyclase Activity ◽  
Adenylate Cyclase Activity ◽  
Parotid Glands ◽  
Adrenergic Agonist ◽  
Rat Submandibular Gland

Many studies previously have shown that the B-adrenergic agonist isoproterenol and the a-adrenergic agonist norepinephrine will stimulate secretion by the adult rat submandibular (SMG) and parotid glands. Recent data from several laboratories indicates that adrenergic agonists bind to specific receptors on the secretory cell surface and stimulate membrane associated adenylate cyclase activity which generates cyclic AMP. The production of cyclic AMP apparently initiates a cascade of events which culminates in exocytosis. During recent studies in our laboratory it was observed that the adenylate cyclase activity in plasma membrane fractions derived from the prenatal and early neonatal rat submandibular gland was retractile to stimulation by isoproterenol but was stimulated by norepinephrine. In addition, in vitro secretion studies indicated that these prenatal and neonatal glands would not secrete peroxidase in response to isoproterenol but would secrete in response to norepinephrine. In contrast to these in vitro observations, it has been shown that the injection of isoproterenol into the living newborn rat results in secretion of peroxidase by the SMG (1).

Desmosomal distribution in the epidermis of a non-contracting human skin equivalent

1992 ◽  
Vol 50 (1) ◽  
pp. 896-897
Author(s):  
L.X. Oakford ◽  
S.D. Dimitrijevich ◽  
R. Gracy
Keyword(s):  
Human Skin ◽  
Basal Layer ◽  
Skin Equivalent ◽  
Tissue Component ◽  
Intact Skin ◽  
Similar Sequence ◽  
Sequence Of Events ◽  
Suprabasal Keratinocytes ◽  
Human Skin Equivalent

In intact skin the epidermal layer is a dynamic tissue component which is maintained by a basal layer of mitotically active cells. The protective upper epidermis, the stratum corneum, is generated by differentiation of the suprabasal keratinocytes which eventually desquamate as anuclear comeocytes. A similar sequence of events is observed in vitro in the non-contracting human skin equivalent (HSE) which was developed in this lab (1). As a part of the definition process for this model of living skin we are examining its ultrastructural features. Since desmosomes are important in maintaining cell-cell interactions in stratified epithelia their distribution in HSE was examined.

Nanocurcumin: A Double-Edged Sword for Microcancers

2020 ◽  
Vol 26 (45) ◽  
pp. 5783-5792
Author(s):  
Kholood Abid Janjua ◽  
Adeeb Shehzad ◽  
Raheem Shahzad ◽  
Salman Ul Islam ◽  
Mazhar Ul Islam
Keyword(s):  
Intracellular Signaling ◽  
Dosage Forms ◽  
The Body ◽  
In Vivo Studies ◽  
Mrna Levels ◽  
Anticancer Activities ◽  
Road Map ◽  
Anticancer Effects

There is compelling evidence that drug molecules isolated from natural sources are hindered by low systemic bioavailability, poor absorption, and rapid elimination from the human body. Novel approaches are urgently needed that could enhance the retention time as well as the efficacy of natural products in the body. Among the various adopted approaches to meet this ever-increasing demand, nanoformulations show the most fascinating way of improving the bioavailability of dietary phytochemicals through modifying their pharmacokinetics and pharmacodynamics. Curcumin, a yellowish pigment isolated from dried ground rhizomes of turmeric, exhibits tremendous pharmacological effects, including anticancer activities. Several in vitro and in vivo studies have shown that curcumin mediates anticancer effects through the modulation (upregulation and/or downregulations) of several intracellular signaling pathways both at protein and mRNA levels. Scientists have introduced multiple modern techniques and novel dosage forms for enhancing the delivery, bioavailability, and efficacy of curcumin in the treatment of various malignancies. These novel dosage forms include nanoparticles, liposomes, micelles, phospholipids, and curcumin-encapsulated polymer nanoparticles. Nanocurcumin has shown improved anticancer effects compared to conventional curcumin formulations. This review discusses the underlying molecular mechanism of various nanoformulations of curcumin for the treatment of different cancers. We hope that this study will make a road map for preclinical and clinical investigations of cancer and recommend nano curcumin as a drug of choice for cancer therapy.

scholarly journals Mechanism of CK2.3, a Novel Mimetic Peptide of Bone Morphogenetic Protein Receptor Type IA, Mediated Osteogenesis

2019 ◽  
Vol 20 (10) ◽  
pp. 2500 ◽  
Author(s):  
Vrathasha Vrathasha ◽  
Hilary Weidner ◽  
Anja Nohe
Keyword(s):  
Signaling Pathways ◽  
Treatment Options ◽  
Time Frame ◽  
Bmp Signaling ◽  
C2c12 Cells ◽  
Molecular Sequence ◽  
Sequence Of Events ◽  
Protein Receptor

Background: Osteoporosis is a degenerative skeletal disease with a limited number of treatment options. CK2.3, a novel peptide, may be a potential therapeutic. It induces osteogenesis and bone formation in vitro and in vivo by acting downstream of BMPRIA through releasing CK2 from the receptor. However, the detailed signaling pathways, the time frame of signaling, and genes activated remain largely unknown. Methods: Using a newly developed fluorescent CK2.3 analog, specific inhibitors for the BMP signaling pathways, Western blot, and RT-qPCR, we determined the mechanism of CK2.3 in C2C12 cells. We then confirmed the results in primary BMSCs. Results: Using these methods, we showed that CK2.3 stimulation activated OSX, ALP, and OCN. CK2.3 stimulation induced time dependent release of CK2β from BMPRIA and concurrently CK2.3 colocalized with CK2α. Furthermore, CK2.3 induced BMP signaling depends on ERK1/2 and Smad1/5/8 signaling pathways. Conclusion: CK2.3 is a novel peptide that drives osteogenesis, and we detailed the molecular sequence of events that are triggered from the stimulation of CK2.3 until the induction of mineralization. This knowledge can be applied in the development of future therapeutics for osteoporosis.

The in vitro neonatal rat spinal cord preparation: a new insight into mammalian locomotor mechanisms

2004 ◽  
Vol 190 (5) ◽  
pp. 343-357 ◽  
Author(s):  
F. Clarac ◽  
E. Pearlstein ◽  
J. F. Pflieger ◽  
L. Vinay
Keyword(s):  
Spinal Cord ◽  
Neonatal Rat ◽  
Rat Spinal Cord ◽  
Insight Into

Dementia with Lewy bodies—associated ß-synuclein mutations V70M and P123H cause mutation-specific neuropathological lesions

2021 ◽  
Author(s):  
Maryna Psol ◽  
Sofia Guerin Darvas ◽  
Kristian Leite ◽  
Sameehan U Mahajani ◽  
Mathias Bähr ◽  
...  
Keyword(s):  
Neuronal Network ◽  
Dementia With Lewy Bodies ◽  
Lewy Bodies ◽  
Sporadic Case ◽  
Network Activity ◽  
Proteinase K ◽  
Neuronal Network Activity ◽  
Distinct Disease

Abstract ß-Synuclein (ß-Syn) has long been considered to be an attenuator for the neuropathological effects caused by the Parkinson’s disease-related α-Synuclein (α-Syn) protein. However, recent studies demonstrated that overabundant ß-Syn can form aggregates and induce neurodegeneration in CNS neurons in vitro and in vivo, albeit at a slower pace as compared to α-Syn. Here we demonstrate that ß-Syn mutants V70M, detected in a sporadic case of Dementia with Lewy Bodies (DLB), and P123H, detected in a familial case of DLB, robustly aggravate the neurotoxic potential of ß-Syn. Intriguingly, the two mutations trigger mutually exclusive pathways. ß-Syn V70M enhances morphological mitochondrial deterioration and degeneration of dopaminergic and non-dopaminergic neurons, but has no influence on neuronal network activity. Conversely, ß-Syn P123H silences neuronal network activity, but does not aggravate neurodegeneration. ß-Syn WT, V70M and P123H formed proteinase K (PK) resistant intracellular fibrils within neurons, albeit with less stable C-termini as compared to α-Syn. Under cell free conditions, ß-Syn V70M demonstrated a much slower pace of fibril formation as compared to WT ß-Syn, and P123H fibrils present with a unique phenotype characterized by large numbers of short, truncated fibrils. Thus, it is possible that V70M and P123H cause structural alterations in ß-Syn, that are linked to their distinct neuropathological profiles. The extent of the lesions caused by these neuropathological profiles is almost identical to that of overabundant α-Syn, and thus likely to be directly involved into etiology of DLB. Over all, this study provides insights into distinct disease mechanisms caused by mutations of ß-Syn.

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