Differential myocardial abundance of collagen type I and type III mRNA in dilated cardiomyopathy: effects of myocardial inflammation.
OBJECTIVE
The collagen subtypes I (Col I) and III (Col III) are essential components of the cardiac extracellular matrix (ECM) maintaining the functional integrity of the heart. Histological, immunohistological, and biochemical studies, however, demonstrate characteristical changes of the ECM in dilated cardiomyopathy, myocarditis, ischemic cardiomyopathy, and hypertensive heart disease.


METHODS
In order to investigate possible effects of inflammatory processes on mRNA abundance of Col I and Col III, we examined 24 patients with the presumptive clinical diagnosis of dilated cardiomyopathy (EF = 30 +/- 11%). 12 Patients were classified as idiopathic dilated cardiomyopathy without any evidence of myocardial inflammation; the remaining 12 patients were classified as inflammatory cardiomyopathy due to the immunohistologically documented inflammatory myocardial process.


RESULTS
Quantification of reverse transcription polymerase chain reaction (RT-PCR) products revealed significant differences as to the mRNA abundance ratio Col III/Col I between subgroups of patients with inflammatory cardiomyopathy (1.16 +/- 0.18) and idiopathic dilated cardiomyopathy (2.77 +/- 0.65) regardless of left ventricular dysfunction (p < or = 0.05).


CONCLUSIONS
It is not yet known, whether different Col III/Col I ratios differentially influence diastolic compliance. Our data suggest that inflammatory mechanisms seen in inflammatory cardiomyopathy influence the mRNA abundance of collagen subtypes I and III.
Pauschinger
M
M
Department of Cardiology, Universitätsklinikum Benjamin Franklin, Freien Universität Berlin, Germany.
Doerner
A
A
Remppis
A
A
Tannhäuser
R
R
Kühl
U
U
Schultheiss
H P
HP
D000328:Adult; D015139:Blotting, Southern; D017252:CD3 Complex; D002311:Cardiomyopathy, Dilated / Q000150:complications / Q000276:immunology / Q000378:metabolism*; D003094:Collagen / Q000235:genetics / Q000378:metabolism*; D005109:Extracellular Matrix / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008214:Lymphocytes / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009205:Myocarditis / Q000150:complications* / Q000276:immunology / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis
D017252:CD3 Complex; D012333:RNA, Messenger; D003094:Collagen