Detection of cardiomyocyte apoptosis in forensic autopsy cases

Abstract

The purpose of the present study was to determine reliable parameters for the detection of apoptotic cells for use as a diagnostic marker during the early stage of acute myocardial infarction (AMI) in forensic autopsy cases. Myocardial tissues taken from forensic autopsy cases were examined by immunohistochemical and molecular-biological methods using the terminal deoxynucleotidyl transferase-mediated dUTP biotin nick end-labelling (TUNEL) and the DNA laddering methods. In cases of AMI with a time period between 2 h from onset to death and 20 h post-mortem time, the nuclei of cardiomyocytes were stained positive with the TUNEL method and DNA fragmentation of myocardial cells was detected by agarose gel electrophoresis. Similar findings were obtained in cases of carbon monoxide (CO) intoxication. However, no apoptotic cells were found in other cases such as methamphetamine (MAP) intoxication, tetrodotoxin intoxication, alcohol intoxication, asphyxia, head injury, heart injury or myocarditis. These findings suggested that it would be possible to apply TUNEL-positive cells as a diagnostic marker during the early stages of AMI.

The role of p53, bax, bcl2, and 8-OHdG in human acute myocardial infarction

“…Previous studies have reported the presence of apoptosis in most cases of AMI [34][35][36][37]. These studies demonstrated that during an AMI widespread apoptosis occurs and is evident only a few hours after the onset of AMI, prior to the appearance of necrosis [35].…”

Apoptosis in Human Acute Myocardial Infarction: The Rationale for Clinical Trials of Apoptosis Inhibition in Acute Myocardial Infarction

“…Another issue is that 5 of 22 of the published studies did not report the time from the onset of symptoms to death. Most autopsies were performed within 24 to 30 hours of patient death because excessively long time periods would have limited the accurate detection of apoptosis [21]. Unfortunately, in half of the studies, the time from the death to autopsy is uncertain.…”

“…The presence of TUNEL staining in nuclei of myocardial cells is a function of the time from death to autopsy because postmortem autolysis damages the DNA and limits detection of the characteristic apoptosis. Nakatome et al reported that all 6 cases with autopsies between 5 to 30 hours after death showed TUNEL-positive cells in the infarct while none of 6 cases who had autopsies 24 to 63 after death showed TUNELpositive cells [21].…”

“…Itoh et al were the first to report DNA fragmentation in the infarcted myocardium but not in normal myocardium [11]. It has been examined in seven studies and the characteristic DNA fragmentation has been consistently demonstrated (Table 2) in the myocardium of patents following MI [11,12,14,18,19,21,34]. In contrast, there is no DNA fragmentation in hearts from individuals who did not die of MI or in normal myocardium remote from the MI [12,14,19].…”

“…Histologic staining of the myocardium to show nuclei with specific DNA fragmentation has been accomplished by staining for in situ end-labeling (ISEL), TUNEL, or ssDNA. The early studies used ISEL or TUNEL and reported either the presence or absence of apoptosis with the conclusion that apoptosis was present in most cases of acute MI [10,14,16,21] (Table 3). These studies, therefore, demonstrated that widespread apoptosis occurs in acute MI since apoptosis was evident after only a few hours after the onset of MI and prior to the appearance of necrosis [14].…”