Oxidative stress disruption of receptor-mediated calcium signaling mechanisms
| Autor: | Chiung-Tan Chang, Rhett A Reichard, Joshua D Erickson, Yue-Wern Huang, Adam L. Martin, Robert S. Aronstam, Hsiu-Jen Wang, Tso-hao Tang, Alexis G Martin, Erica K. Shannon |
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| Jazyk: | angličtina |
| Rok vydání: | 2013 |
| Předmět: |
medicine.medical_specialty
Cytoplasm Thapsigargin Cell Survival Endocrinology Diabetes and Metabolism Calcium pump Clinical Biochemistry chemistry.chemical_element CHO Cells Calcium Endoplasmic Reticulum Muscarinic acetylcholine receptor chemistry.chemical_compound Cricetulus tert-Butylhydroperoxide Internal medicine Cricetinae Phospholipase Cβ medicine Animals Pharmacology (medical) Molecular Biology Calcium signaling Biochemistry medical Calcium metabolism Ion Transport Research Biochemistry (medical) Muscarinic acetylcholine receptor M3 Inositol trisphosphate Inositol trisphosphate (IP3) Cell Biology General Medicine Store-operated calcium entry (SOCE) Inositol trisphosphate receptor Oxidative Stress Endocrinology chemistry Biophysics Carrier Proteins Signal Transduction |
| Zdroj: | Journal of Biomedical Science |
| ISSN: | 1423-0127 1021-7770 |
| Popis: | Background Oxidative stress increases the cytosolic content of calcium in the cytoplasm through a combination of effects on calcium pumps, exchangers, channels and binding proteins. In this study, oxidative stress was produced by exposure to tert-butyl hydroperoxide (tBHP); cell viability was assessed using a dye reduction assay; receptor binding was characterized using [3H]N-methylscopolamine ([3H]MS); and cytosolic and luminal endoplasmic reticulum (ER) calcium concentrations ([Ca2+]i and [Ca2+]L, respectively) were measured by fluorescent imaging. Results Activation of M3 muscarinic receptors induced a biphasic increase in [Ca2+]i: an initial, inositol trisphosphate (IP3)-mediated release of Ca2+ from endoplasmic reticulum (ER) stores followed by a sustained phase of Ca2+ entry (i.e., store-operated calcium entry; SOCE). Under non-cytotoxic conditions, tBHP increased resting [Ca2+]i; a 90 minute exposure to tBHP (0.5-10 mM ) increased [Ca2+]i from 26 to up to 127 nM and decreased [Ca2+]L by 55%. The initial response to 10 μM carbamylcholine was depressed by tBHP in the absence, but not the presence, of extracellular calcium. SOCE, however, was depressed in both the presence and absence of extracellular calcium. Acute exposure to tBHP did not block calcium influx through open SOCE channels. Activation of SOCE following thapsigargin-induced depletion of ER calcium was depressed by tBHP exposure. In calcium-free media, tBHP depressed both SOCE and the extent of thapsigargin-induced release of Ca2+ from the ER. M3 receptor binding parameters (ligand affinity, guanine nucleotide sensitivity, allosteric modulation) were not affected by exposure to tBHP. Conclusions Oxidative stress induced by tBHP affected several aspects of M3 receptor signaling pathway in CHO cells, including resting [Ca2+]i, [Ca2+]L, IP3 receptor mediated release of calcium from the ER, and calcium entry through the SOCE. tBHP had little effect on M3 receptor binding or G protein coupling. Thus, oxidative stress affects multiple aspects of calcium homeostasis and calcium dependent signaling. |
| Databáze: | OpenAIRE |
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