Dataset Information

Formaldehyde increases intracellular calcium concentration in primary cultured hippocampal neurons partly through NMDA receptors and T-type calcium channels.

ABSTRACT: Formaldehyde at high concentrations is a contributor to air pollution. It is also an endogenous metabolic product in cells, and when beyond physiological concentrations, has pathological effects on neurons. Formaldehyde induces mis-folding and aggregation of neuronal tau protein, hippocampal neuronal apoptosis, cognitive impairment and loss of memory functions, as well as excitation of peripheral nociceptive neurons in cancer pain models. Intracellular calcium ([Ca(2+)](i)) is an important intracellular messenger, and plays a key role in many pathological processes. The present study aimed to investigate the effect of formaldehyde on [Ca(2+)](i) and the possible involvement of N-methyl-D-aspartate receptors (NMDARs) and T-type Ca(2+) channels on the cell membrane.Using primary cultured hippocampal neurons as a model, changes of [Ca(2+)](i) in the presence of formaldehyde at a low concentration were detected by confocal laser scanning microscopy.Formaldehyde at 1 mmol/L approximately doubled [Ca(2+)](i). (2R)-amino-5-phosphonopentanoate (AP5, 25 μmol/L, an NMDAR antagonist) and mibefradil (MIB, 1 μmol/L, a T-type Ca(2+) channel blocker), given 5 min after formaldehyde perfusion, each partly inhibited the formaldehyde-induced increase of [Ca(2+)](i), and this inhibitory effect was reinforced by combined application of AP5 and MIB. When applied 3 min before formaldehyde perfusion, AP5 (even at 50 μmol/L) did not inhibit the formaldehyde-induced increase of [Ca(2+)](i), but MIB (1 μmol/L) significantly inhibited this increase by 70%.These results suggest that formaldehyde at a low concentration increases [Ca(2+)](i) in cultured hippocampal neurons; NMDARs and T-type Ca(2+) channels may be involved in this process.

SUBMITTER: Chi YN

PROVIDER: S-EPMC5561821 | biostudies-other | 2012 Dec

REPOSITORIES: biostudies-other

ACCESS DATA

Similar Datasets

Project description:BACKGROUND:Skeletal muscle atrophy is the net loss of muscle mass that results from an imbalance in protein synthesis and protein degradation. It occurs in response to several stimuli including disease, injury, starvation, and normal aging. Currently, there is no truly effective pharmacological therapy for atrophy; therefore, exploration of the mechanisms contributing to atrophy is essential because it will eventually lead to discovery of an effective therapeutic target. The ether-a-go-go related gene (ERG1A) K+ channel has been shown to contribute to atrophy by upregulating ubiquitin proteasome proteolysis in cachectic and unweighted mice and has also been implicated in calcium modulation in cancer cells. METHODS:We transduced C2C12 myotubes with either a human ERG1A encoded adenovirus or an appropriate control virus. We used fura-2 calcium indicator to measure intracellular calcium concentration and Calpain-Glo assay kits (ProMega) to measure calpain activity. Quantitative PCR was used to monitor gene expression and immunoblot evaluated protein abundances in cell lysates. Data were analyzed using either a Student's t test or two-way ANOVAs and SAS software as indicated. RESULTS:Expression of human ERG1A in C2C12 myotubes increased basal intracellular calcium concentration 51.7% (p?<?0.0001; n?=?177). Further, it increased the combined activity of the calcium-activated cysteine proteases, calpain 1 and 2, by 31.9% (p?<?0.08; n?=?24); these are known to contribute to degradation of myofilaments. The increased calcium levels are likely a contributor to the increased calpain activity; however, the change in calpain activity may also be attributable to increased calpain protein abundance and/or a decrease in levels of the native calpain inhibitor, calpastatin. To explore the enhanced calpain activity further, we evaluated expression of calpain and calpastatin genes and observed no significant differences. There was no change in calpain 1 protein abundance; however, calpain 2 protein abundance decreased 40.7% (p?<?0.05; n?=?6). These changes do not contribute to an increase in calpain activity; however, we detected a 31.7% decrease (p?<?0.05; n?=?6) in calpastatin which could contribute to enhanced calpain activity. CONCLUSIONS:Human ERG1A expression increases both intracellular calcium concentration and combined calpain 1 and 2 activity. The increased calpain activity is likely a result of the increased calcium levels and decreased calpastatin abundance.

Dataset Information

Formaldehyde increases intracellular calcium concentration in primary cultured hippocampal neurons partly through NMDA receptors and T-type calcium channels.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure