Simultaneous immunophenotypical assessment of troponin and extracellular matrix molecules in myocardium of patients with sudden cardiac death

Vol. 50 No. 1, 2009

ROMANIAN JOURNAL of MORPHOLOGY and EMBRYOLOGY

M. Ceauşu, C. Curcă, D. Dermengiu, Carmen Ardeleanu

In patients with sudden unexpected cardiac death, there is a relationship between the interstitial fibrosis of the myocardium and matrix molecules with a role in global remodeling of the cardiac stroma. Tissue samples of left ventricular myocardium from 17 middle-aged patients with sudden cardiac death, following acute or chronic ischemic cardio(myo)pathies, were analyzed using standard HE stain and the indirect tristadial ABC peroxidase immunohistochemical method for a panel of four antibodies involved in the dynamic remodeling of extracellular matrix: matrix metalloproteinase 9 (MMP9), tenascin X (Tn-X), TGF-b, CD54 (ICAM-1), together with simultaneously assessment of troponin in myocardic fibers. The most sensitive reaction was noticed for ICAM-1 in 71% of cases, followed by MMP9 in 59% of cases and TGF-b in 47% of cases (with great specificity for capillary vessels), in the extracellular matrix of the residual cardiomyocytes. A direct correlation, statistically significant was recorded between troponin and MMP9 (r = 0.65, p = 0.01), troponin and ICAM-1 (r = 0.31, p = 0.02), respectively ICAM-1 and tenascin (r = 0.72, p = 0.01). The extensive expression of ICAM-1 in the extracellular matrix from the perilesional area probably plays a role in the stimulation of new developing adhesion substrates between residual cells and adjacent stroma, while the over expression of troponin in the residual cardiomyocytes is accompanied by a high expression of MMP9 in the myocardic interstitium, with heterogeneous remodeling of the ventricular stroma. The simultaneous IHC expression of tenascin and ICAM-1 suggests a colocalization required for the nerve sprouting in the residual myocardium and for developing new focal cell-matrix adhesion contacts.

Corresponding author: Mihai Ceauşu, MD, PhD, e-mail: ceausu_mihai@yahoo.com

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