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Published on: September 19, 2011
An immunohistochemical study of feline myocardial fibrosis
H Aupperle1, K Baldauf, I März
1Institute für Veterinär-Pathologie, An den Tierkliniken 33, Veterinärmedizinische Fakultät, Universität Leipzig, An den Tierkliniken 23, 04103 Leipzig, Germany. aupperle@laboklin.de
Insights
Feline myocardial fibrosis involves complex cardiac remodelling. Cardiomyocytes play a significant role in this process, showing altered expression of matrix metalloproteinases and transforming growth factor-beta.
Area of Science:
- Veterinary Pathology
- Cardiovascular Research
- Feline Medicine
Background:
- Feline myocardial fibrosis is a significant cardiac condition in cats.
- Understanding the cellular mechanisms and pathological changes is crucial for diagnosis and treatment.
- Previous studies have indicated alterations in cardiac tissue, but the specific cellular contributions remain unclear.
Purpose of the Study:
- To investigate the pathological mechanisms of feline myocardial fibrosis.
- To compare the molecular and cellular changes in fibrotic feline hearts versus normal hearts.
- To identify the role of cardiomyocytes and fibroblasts in the fibrotic process.
Main Methods:
- Comparative analysis of 40 feline hearts with myocardial fibrosis and 25 normal feline hearts.
- Echocardiography to assess cardiac function and morphology.
- Immunohistochemical analysis to evaluate the expression of matrix metalloproteinases (MMPs), tissue inhibitors of matrix metalloproteinases (TIMPs), and transforming growth factor-beta (TGF-β) in cardiomyocytes and fibroblasts.
Main Results:
- Hearts with myocardial fibrosis exhibited hypomotility and hyperechoic ventricular walls on echocardiography.
- Fibrosis correlated significantly with ventricular hypertrophy, atrial dilation, and angiosclerosis.
- In affected hearts, cardiomyocytes showed increased expression of MMP-2, TIMP-3, and TGF-β2, with decreased TIMP-2 expression. Fibroblasts expressed MMP-14 in some cases.
Conclusions:
- A complex fibrotic remodelling process occurs in feline myocardial fibrosis.
- Cardiomyocytes are actively involved in the pathogenesis of feline myocardial fibrosis through altered protein expression.
- These findings highlight the cellular basis of cardiac remodeling in feline heart disease.
Abstract:
The aim of the present study was to investigate the pathology of feline myocardial fibrosis. The hearts from 40 cats with myocardial fibrosis were compared with the hearts from 25 normal cats. Clinical data were available in 11 cases. Hearts with myocardial fibrosis were hypomotile and there were hyperechoic areas in the ventricular wall on echocardiography. The presence of myocardial fibrosis was correlated significantly with hypertrophy of the ventricles, atrial dilation and angiosclerosis. Immunohistochemical studies demonstrated that normal feline cardiomyocytes expressed matrix metalloproteinase (MMP)-2, MMP-9, MMP-14, tissue inhibitor of matrix metalloproteinase (TIMP)-2 and transforming growth factor (TGF)-β2. Fibroblasts in normal hearts expressed only TIMP-2. In the hearts with myocardial fibrosis, expression of MMP-2, TIMP-3 and TGF-β2 by cardiomyocytes was significantly increased, but TIMP-2 expression was diminished. Fibroblasts in the affected hearts showed expression of MMP-14 in several cases. These findings suggest that a complex fibrotic remodelling of the feline myocardium occurs in this disease and that cardiomyocytes are involved in this process.
