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Series GSE8367 Query DataSets for GSE8367
Status Public on Dec 31, 2009
Title Sustained L-type Calcium Channel Blockade Alters Gene Regulation in the Adult Mouse Ventricle
Organism Mus musculus
Experiment type Expression profiling by array
Summary Objective: L-type calcium channels (LTCC) homeostatically regulate calcium on a beat by beat basis, but also provide Ca that over long time scales may contribute to transcriptional regulation. We previously showed that sustained LTCC blockade (CCB) elicits LTCC remodeling in ventricular cardiac myocytes (CM). Here we hypothesize that sustained CCB has broad effects on the expression of genes involved in calcium handling. Methods and Results: Therefore, we subjected adult mice to sustained CCB for 24 hours and performed gene expression profiling. In comparison to vehicle-only control animals, 231 genes were up-regulated, and 111 genes were down-regulated by sustained LTCC blockade (p <0.01). Gene ontology analysis suggested that the CaMKIIdelta signaling pathway was up-regulated in these cells. Unexpectedly, phosphorylation of phospholamban (PLN) at threonine17 (Thr17), an index of CaMKIIdelta activity, was not changed by sustained CCB; however, the degree of phosphorylation of the neighboring PLN-Ser16 substrate site for PKA was significantly reduced by sustained CCB compared to control. Gene expression profiling suggested no change in PKA, but it showed that protein phosphatase 2A (PP2A) mRNA increased, and immunoblots demonstrated that PP2Ac-alpha protein was significantly increased by sustained CCB. Consistent with elevated PP2Ac-alpha protein expression LTCC exhibited decreased phosphorylation of the C-terminal Ser1928 PKA substrate site. Conclusions: We conclude that sustained CCB elicits a spectrum of transcriptional events, including compensatory up-regulation of LTCC and PP2Ac-alpha. Although this study is restricted to mouse, these results suggest the new hypothesis that clinically-relevant sustained LTCC blockade in humans results in changes in gene regulation in the heart.
Keywords: L-type calcium channel, calcium channel blockade, verapamil
 
Overall design Female and male ICR mice (12-14 weeks age) weighing between 25 and 30 grams were anesthetized with a ketamine/xylazine mixture ( i.p.) allowing the subcutaneous implantation of miniosmotic pumps (Alzet, model 2001). The pumps were filled with either verapamil or vehicle (0.02% ascorbic acid). Control animals carried mini-pumps with vehicle and control animals were investigated in parallel with each set of experimental animals. Mini pumps delivered verapamil at 3.6 mg/kg/day for 24 (RNA)-48 (protein) hours. After treatment animals were anesthetized and weighed. Hearts were excised, rinsed, blotted dry, weighed, and then frozen on dry ice and the stored at -80oC until studied. Animals were anesthetized and euthanized according to animal protocols approved by the University of Kentucky Institutional Animal Care and Use Committee. This investigation conforms with the Guide for the Care and Use of Laboratory Animals published by the US National Institutes of Health (NIH Publication NO. 85-23, revised 1996).

Left ventricular free wall from female mice was rapidly excised and either snap frozen at -80oC or used immediately for RNA isolation. Three VER treated mice and 3 vehicle treated mice were used to generate RNA for microarray. Total RNA was isolated using the RNAqueous -4PCR kit (Ambion) and quantitated spectrophotometrically at 260nm. Contaminating genomic DNA was eliminated by DNase treatment (Ambion). RNA quality was assessed using the Agilent 2100 Bioanalyzer. Microarray data was obtained using the Affymetrix 430 V2 GeneChip (representing 45,101 probe sets), in accordance with the manufacturer’s specifications.
 
Contributor(s) Schroder EA, Satin J
Citation missing Has this study been published? Please login to update or notify GEO.
Submission date Jul 03, 2007
Last update date Feb 11, 2019
Contact name Elizabeth Anne Schroder
E-mail(s) eschr0@uky.edu
Phone 859-323-2918
Organization name University of Kentucky
Department Physiology
Lab Satin Lab
Street address 800 Rose Street, MS508
City Lexington
State/province KY
ZIP/Postal code 40536-0298
Country USA
 
Platforms (1)
GPL1261 [Mouse430_2] Affymetrix Mouse Genome 430 2.0 Array
Samples (12)
GSM201495 Sustained L-type Calcium Channel Blockade Alters Gene Regulation in the Adult Mouse Ventricle
GSM202328 Sustained L-type Calcium Channel Blockade Alters Gene Regulation in the Adult Mouse Ventricle-VER1
GSM202329 Sustained L-type Calcium Channel Blockade Alters Gene Regulation in the Adult Mouse Ventricle- VER2
Relations
BioProject PRJNA101393

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Series Matrix File(s) TXTHelp

Supplementary file Size Download File type/resource
GSE8367_RAW.tar 47.8 Mb (http)(custom) TAR (of CEL, CHP)
Raw data provided as supplementary file
Processed data included within Sample table
Processed data provided as supplementary file

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