Expression of phospholipase D isozymes in scar and viable tissue in congestive heart failure due to myocardial infarction

• Published in: Journal of cellular and molecular medicine 2004-10, Vol.8 (4), p.526-536
• Main Authors: Dent, Melissa R., Singal, Tushi, Dhalla, Naranjan S., Tappia, Paramjit S.
• Format: Article
• Language: English
• Subjects: Animals; Blotting, Western; Body Weight; cardiac sarcolemma; Cicatrix - pathology; Congestive heart failure; Coronary artery; Gene expression; Guanosine 5'-O-(3-Thiotriphosphate) - metabolism; Heart; Heart attack; Heart attacks; Heart failure; Heart Failure - enzymology; Heart Ventricles - pathology; Hydrolysis; Isoenzymes; Lecithin; Lipids; Male; Membrane proteins; Myocardial infarction; Myocardial Infarction - enzymology; Myocardium - metabolism; Phosphatidic acid; Phosphatidic Acids - chemistry; Phosphatidylcholine; Phospholipase D; Phospholipase D - chemistry; phospholipase D isozymes; Phospholipases; Phospholipids; Protein Isoforms; Proteins; Rats; Rats, Sprague-Dawley; Reverse Transcriptase Polymerase Chain Reaction; RNA; RNA - metabolism; RNA, Messenger - metabolism; RNA-directed DNA polymerase; scar tissue; Time Factors
• ISSN: 1582-1838; 1582-4934
• DOI: 10.1111/j.1582-4934.2004.tb00477.x

The phospholipase D (PLD) associated with the cardiac sarcolemmal (SL) membrane hydrolyses phosphatidylcholine to produce phosphatidic acid, an important phospholipid signaling molecule known to influence cardiac function. The present study was undertaken to examine PLD isozyme mRNA expression, protein contents and activities in congestive heart failure (CHF) subsequent to myocardial infarction (MI). MI was induced in rats by occlusion of the left anterior descending coronary artery. At 8 weeks after the surgical procedure, hemodynamic assessment revealed that these experimental rats were at a moderate stage of CHF. Semi‐quantitative reverse transcriptase‐polymerase chain reaction revealed that PLD1 and PLD2 mRNA amounts were unchanged in viable left ventricular (LV) tissue of the failing heart. Furthermore, this technique demonstrated the presence of PLD1 and PLD2 mRNA in the scar tissue. While SL PLD1 and PLD2 protein contents were elevated in the viable LV tissue of the failing heart, SL PLD1 activity was significantly decreased, whereas SL PLD2 activity was significantly increased. On the other hand, although PLD1 protein was undetectable, PLD2 protein and activity were detected in the scar tissue. Our findings suggest that differential changes in PLD isozymes may contribute to the pathophysiology of CHF and may also be involved in the processes of scar remodeling.