901-26 Coexpression of Vimentin and Ki 67 Indicates Cardiomyocyte Regeneration After Acute Rejection in Human Cardiac Allografts

• Published in: Journal of the American College of Cardiology 1995-02, Vol.25 (2), p.11A-11A
• Main Authors: Behr, Thomas M., Fischer, Petra, Spes, Christoph H., Kur, Felix, Ziegler, Ulrike, Pongratz, Dieter E., Angermann, Christiane E.
• Format: Article
• Language: English
• ISSN: 0735-1097; 1558-3597
• DOI: 10.1016/0735-1097(95)91503-P

Electron microscopy suggests that after acute cardiac allograft rejection (AR) injured adult human cardiomyocytes regenerate. They dedifferentiate and reacquire the condition of embryonic myocytes. A close connection between regeneration and vimentin (vim) expression was shown in an animal model. Vim is an intermediate filament expressed in muscle tissue during development and replaced lateron by desmin. In this study, immunohistochemistry (alkaline phosphatase-, peroxidase- and fluorescence-techniques) was used to further analyze this regeneration process. We obtained endomyocardial biopsies (EMS) of 41 heart transplant patients (9 f, 32 m, mean age 46,160 months postop) on 104 occasions. EMS were graded for AR (ISHLT) and (double-)stained with vim, desmin and Ki67, a proliferating cell marker. vim was expressed in 1-5% of cardiomyocytes in 19/104 EMB (vim+). Double staining with desmin proved the muscular origin of vim+cells. Coexpression of vim and Ki67 indicated myocyte proliferation. Of the 19 vim+EMB all had AR ≥ IA (ISHLT) either in this or in the preceeding EMB (14±7 days). Of the 85 vim negative EMB 59 had no AR, 26 had AR ≥ IA(ISHLT) in this or the preceeding EMB. This is the first report to show that vim can be expressed by adult cardiomyocytes. Expression of vim and Ki67 appears to be related to AR but was not found in all EMB with evidence for AR, either due to sampling error or lack of regeneration in some AR. The data suggest that myocytes damaged by AR may gain myofibrillar regeneration by going through a sequence of embryological development as indicated by expression of vimentin and Ki67. Immunohistochemistry is a useful tool to investigate cardiac regeneration.