Despite a few genes that do not encode ion channels have been identified as implicating some kinds of human idiopathic epilepsies(IE) in recent years, but genetic discoveries have shown the ion channels to play a central role in genetic pathomechanism of IE. The gene mutations of ion channels are a common cause of some rare monogenic IE which could be so-called as channelopathies, and able to be applied to account for the questioned epileptic syndrome to minority of families and sporadic cases. However, more frustrating has been from the genetic research on more common IE with complex inheritance due to the unknown mode of inheritance, the phenotypic heterogeneity and the uncertainty of genetic overlap among syndrome subtypes, which have limited gene mapping. Absence epilepsy is a kind of common IE subtype and shows a complex way to inherit. Evidences from heredity investigation indicate that eleven genes are correlated with absence epilepsy, of which four encode the neuronal calcium channel subunits. Therefore, calcium channel genes may be considered as important candidates for involving in absence epilepsy. To focus the genetics research on calcium channel genes of absence epilepsy may be opening an optimal gate to the pathogenetic study of more common IE with complex inheritance, and benefit to elucidate the molecular mechanisms of absence epilepsy finally, one of the more common IE subtypes with complex inheritance.
Calcium ; metabolism ; Calcium Channels ; genetics ; physiology ; Epilepsy, Absence ; genetics ; physiopathology ; Genetic Predisposition to Disease ; genetics ; Humans ; Models, Biological

OBJECTIVETo construct a rat model of chronic nonbacterial prostatitis (CP) and investigate the difference in the quantitative expression of voltage-dependent calcium channels of prostate smooth muscle cells (PSMCs) between the models and controls.

METHODSWe established a CP rat model by estrogen induction, cultured and purified the PSMCs in vitro, and extracted total RNA by Trizol. Then we measured the mRNA expression of the cal subunit in the calcium channel subtypes by reverse transcription and SYBR Green I real time RT-PCR, and compared it with that of the controls.

RESULTSThe expressions of the L-, T- and P/Q-type calcium channels were found in both the CP and control groups, and that of the CaV1.2 L-type calcium channel was significantly increased in the former as compared with the latter (0.048 +/- 0.024 versus 0.031 +/- 0.015, t = 2.846, P = 0.007), but there were no statistically significant differences in the T- and P/Q-type calcium channels between the two groups.

CONCLUSIONThe number of CaV1.2 L-type calcium channels of PSMCs and calcium influx were increased in CP patients, which may be involved in the mechanism of CP.

Animals ; Calcium Channels, L-Type ; metabolism ; Calcium Channels, Q-Type ; metabolism ; Calcium Channels, T-Type ; metabolism ; Estradiol ; pharmacology ; Male ; Myocytes, Smooth Muscle ; metabolism ; Prostate ; metabolism ; Prostatitis ; metabolism ; RNA, Messenger ; genetics ; Rats ; Rats, Wistar

The acrosome reaction is a Ca(2+)-dependent exocytotic process that is a prerequisite step for fertilization. External calcium entry through voltage-activated Ca(2+)channels is known to be essential in inducing the acrosome reaction of mammalian spermatozoa. Due to their complex geometry, however, electrophysiological identification of sperm Ca(2+)channels has been limited. Here we identified Ca(2+)channel mRNAs expressed in motile human sperm using RT-PCR and their levels were compared using RNase protection assays. L-type, non- L-type, and T-type Ca(2+)channel mRNAs were detected by RT-PCR using degenerate primers. Cloning and sequencing of the PCR products revealed alpha1B, alpha1C, alpha1E, alpha1G, and alpha1H sequences. RT-PCR using specific primers repeatedly detected alpha1B, alpha1C, alpha1E, alpha1G, and alpha1H mRNAs, and additionally alpha1I mRNA. But alpha1A and alpha1D messages were not detected. Relative expression levels of the detected Ca(2+)channel subtypes were compared by RNase protection assays. The abundance of detected mRNA messages was in the following order: alpha1H> or =alpha1G> or =alpha1E> or =alpha1B>alpha1C>alpha1I. These findings indicated that human motile sperm express multiple voltage-activated Ca(2+)channel RNAs among which T-type and non-L-type channel messages are likely to be predominantly expressed. Based on their relative expression levels, we propose that not only T-type but also non-L-type calcium channels may be major gates for the external calcium influx, required for the acrosome reaction.
Calcium/*metabolism ; Calcium Channels/biosynthesis/classification/*genetics ; Human ; Male ; RNA, Messenger/*metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Spermatozoa/*metabolism

During membrane depolarization associated with skeletal excitation-contraction (EC) coupling, dihydropyridine receptor [DHPR, a L-type Ca2+ channel in the transverse (t)-tubule membrane] undergoes conformational changes that are transmitted to ryanodine receptor 1 [RyR1, an internal Ca2+-release channel in the sarcoplasmic reticulum (SR) membrane] causing Ca2+ release from the SR. Canonical-type transient receptor potential cation channel 3 (TRPC3), an extracellular Ca2+-entry channel in the t-tubule and plasma membrane, is required for full-gain of skeletal EC coupling. To examine additional role(s) for TRPC3 in skeletal muscle other than mediation of EC coupling, in the present study, we created a stable myoblast line with reduced TRPC3 expression and without alpha1SDHPR (MDG/TRPC3 KD myoblast) by knock-down of TRPC3 in alpha1SDHPR-null muscular dysgenic (MDG) myoblasts using retrovirus-delivered small interference RNAs in order to eliminate any DHPR-associated EC coupling-related events. Unlike wild-type or alpha1SDHPR-null MDG myoblasts, MDG/TRPC3 KD myoblasts exhibited dramatic changes in cellular morphology (e.g., unusual expansion of both cell volume and the plasma membrane, and multi-nuclei) and failed to differentiate into myotubes possibly due to increased Ca2+ content in the SR. These results suggest that TRPC3 plays an important role in the maintenance of skeletal muscle myoblasts and myotubes.
Animals ; Calcium/metabolism ; Calcium Channels/metabolism ; Calcium Channels, L-Type/genetics/metabolism ; Cations/metabolism ; *Cell Differentiation ; *Cell Proliferation ; Cells, Cultured ; Excitation Contraction Coupling ; Gene Knockdown Techniques ; Membrane Potentials ; Mice ; Muscle Fibers, Skeletal/*metabolism ; Muscle Proteins/metabolism ; Myoblasts, Skeletal/*metabolism ; Ryanodine Receptor Calcium Release Channel/metabolism ; Sarcoplasmic Reticulum/*physiology ; Synaptophysin/metabolism ; TRPC Cation Channels/genetics/*metabolism ; Transient Receptor Potential Channels/metabolism

OBJECTIVETo investigate rapid atrial pacing (RAP) induced atrial ultrastructural changes and mRNA and protein expression changes of L-type calcium channel subunits and potassium channel Kv4.3 in a rabbit model.

METHODSThirty-six rabbits were electrically paced at a frequency of 600 beats/min for durations ranging from 0 - 48 h via bipolar endocardial leads through surgical techniques. Ultrastructural changes of the atrium were observed through a transmission electron microscope (TEM), L-type calcium channel subunits and potassium channel Kv4.3 expressions at mRNA and protein levels were analyzed by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot.

RESULTSAtrial ultrastructure changes characterized by mitochondrial vacuolization, myofilament lysis, and glycogen accumulation were detected obvious at 3 h post pacing. Down-regulated mRNA expression of Ca(2+) channel beta1 and alpha1 subunits was observed 6 h post pacing, Kv4.3 mRNA down-regulation occurred 24 h post pacing, auxiliary subunit alpha2 was not affected by pacing. Protein expression of alpha1c subunit and potassium channel Kv4.3 paralleled their mRNA expression changes.

CONCLUSIONRAP induced ultrastructural changes of the atrium and down-regulated mRNA and protein expressions of L-type calcium channel subunits and potassium channel Kv4.3 occurred thereafter in response to intracellular calcium overload induced by RAP.

Animals ; Calcium Channels, L-Type ; genetics ; metabolism ; Cardiac Pacing, Artificial ; methods ; Female ; Heart Atria ; metabolism ; ultrastructure ; Male ; Patch-Clamp Techniques ; Potassium Channels ; genetics ; metabolism ; RNA, Messenger ; metabolism ; Rabbits

OBJECTIVETo discuss the role of calcium-overloading in initiation and maintenance of atrial fibrillation (AF).

METHODSThe right atrial appendages were obtained from 14 patients with AF and 12 patients with sinus rhythm. The mRNA expression of proteins influencing the calcium homeostasis was measured by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) and normalized to the mRNA level of glyceraldehyde-3- phosphate dehydrogenase. The left atrial diameter (LAD), mitral valvular area (MVOA), and systolic pulmonary arterial pressure were obtained by echocardiography before surgery.

RESULTSCompared to sinus rhythm group, the mRNA levels of L-type calcium channel alc, sarcoplasmic reticulum (SR), calcium adenosine triphosphatase (Ca2+ -ATPase), and ryanodine receptor type-2 (R(Y) R2) were significantly decreased (P < 0.01); the mRNA level of inositol triphosphate receptor type-1 (IP3R1) was significantly increased (P < 0.05). No changes in the mRNA expression of phospholamban and calsequestrin were observed between two groups (P > 0.05). Correlations were found between MVOA and mRNA levels of LVDC-Calc, SR Ca2+ -ATPase (r = 0.719, P = 0.004; r = 0.625, P = 0.017). The mRNA level of SR Ca2+ -ATPase was negatively correlated with LAD (r = -0.573, P = 0.032).

CONCLUSIONSCalcium loading may be responsible for the occurrence and maintenance of AF, and abnormal regulation in the mRNA expression may be the molecular mechanism of intracellular Ca2+ overload. The progressive nature of AF involves structural change.

Arrhythmia, Sinus ; metabolism ; Atrial Fibrillation ; metabolism ; pathology ; Calcium ; metabolism ; Calcium Channels ; biosynthesis ; genetics ; Calcium-Binding Proteins ; biosynthesis ; genetics ; Calcium-Transporting ATPases ; biosynthesis ; genetics ; Chronic Disease ; Heart Atria ; metabolism ; pathology ; Humans ; Mitral Valve ; pathology ; Myocardium ; metabolism ; RNA, Messenger ; biosynthesis

TRPA1 channels are non-selective cation channels that could be activated by plant-derived pungent products, including gingerol, a main active constituent of ginger. Ginger could improve the digestive function; however whether ginger improves the digestive function through activating TRPA1 receptor in gastrointestinal tract has not been investigated. In the present study, gingerol was used to stimulate cell lines (RIN14B or STC-1) while depletion of extracellular calcium. TRPA1 inhibitor (rethenium red) and TRPA1 gene silencing via TRPA1-specific siRNA were also used for mechanistic studies. The intracellular calcium and secretion of serotonin or cholecystokinin were measured by fura-2/AM and ELISA. Stimulation of those cells with gingerol increased intracellular calcium levels and the serotonin or cholecystokinin secretion. The gingerol-induced intracellular calcium increase and secretion (serotonin or cholecystokinin) release were completely blocked by ruthenium red, EGTA, and TRPA1-specific siRNA. In summary, our results suggested that gingerol derived from ginger might improve the digestive function through secretion releasing from endocrine cells of the gut by inducing TRPA1-mediated calcium influx.
Calcium ; metabolism ; Calcium Channels ; genetics ; metabolism ; Catechols ; pharmacology ; Cell Line ; Fatty Alcohols ; pharmacology ; Gastrointestinal Tract ; drug effects ; metabolism ; Ginger ; chemistry ; Humans ; Nerve Tissue Proteins ; genetics ; metabolism ; Plant Extracts ; pharmacology ; TRPA1 Cation Channel ; Transient Receptor Potential Channels ; genetics ; metabolism

A growing body of evidence, including studies using genetically engineered mouse models, has shown that Ca2+ cycling and Ca2+ -dependent signaling pathways play a pivotal role in cardiac hypertrophy and heart failure. In addition, recent studies identified that mutations of the genes encoding sarcoplasmic reticulum (SR) proteins cause human cardiomyopathies and lethal ventricular arrhythmias. The regulation of Ca2+ homeostasis via the SR proteins may have potential therapeutic value for heart diseases such as cardiomyopathy, heart failure and arrhythmias.
Animals ; Animals, Genetically Modified ; Arrhythmia/genetics ; Calcium/*metabolism ; Calcium Channels/genetics/*physiology ; Calcium-Binding Proteins/genetics/*physiology ; Cardiac Output, Low/genetics ; Cardiomyopathies/genetics ; Heart Diseases/*etiology/genetics/metabolism ; Humans ; Mutation/genetics ; Research Support, Non-U.S. Gov't ; Sarcoplasmic Reticulum/metabolism

The present study was aimed to investigate the effect of Janus kinase 3 (JAK3) on the migration of breast cancer cells and the underlying mechanism. The expression of JAK3 in breast cancer MCF-7 cells was silenced by siRNA (siJAK3). The migration ability of MCF-7 cells was detected by scratch test. The activity of store-operated calcium channel (SOCC) was detected by fluorescence calcium imaging. The expression levels of Orai1 and STIM1, key molecules in the process of store-operated calcium entry (SOCE) were detected by Western blot and RT-PCR. The results showed that 2-APB, an inhibitor of SOCC, could inhibit the migration ability of MCF-7 cells. siJAK3 transfection significantly inhibited the migration ability of MCF-7 cells, decreased the activity of SOCC, and down-regulated mRNA and protein expression levels of Orai1 and Stim1. Over-expression of Orai1 or STIM1 in JAK3-silenced cells restored their migration ability. These results suggest that JAK3 facilitates the migration of breast cancer cells by SOCC.
Breast Neoplasms ; enzymology ; Calcium ; metabolism ; Calcium Channels ; metabolism ; Cell Movement ; physiology ; Gene Expression Regulation, Neoplastic ; Humans ; Janus Kinase 3 ; genetics ; metabolism ; MCF-7 Cells ; ORAI1 Protein ; genetics

Action Potentials ; Animals ; Calcium Channels, L-Type ; genetics ; Dogs ; Heart Atria ; metabolism ; Kv Channel-Interacting Proteins ; genetics ; RNA, Messenger ; analysis ; Shal Potassium Channels ; genetics