Journal List > Korean J Leg Med > v.39(1) > 1087970

Ahn and Huh: The Efficacy of Connexin 43 Expression in the Myocardium as an Early Ischemic Marker in Forensic Autopsy

Abstract

The postmortem diagnosis of ischemic heart disease is sometimes difficult for forensic pathologists especially when microscopic ischemic change in the myocardium is not detected at the early stages of ischemic injury by conventional staining techniques. Connexin 43 (Cx43) is a gap junction protein in human myocardium, which is phosphorylated and localized to the intercalated discs in the normal cardiac muscles. However, during ischemia and hypoxia, total Cx43 (tCx43) undergoes progressive dephosphorylation and concomitant accumulation of non-phosphorylated Cx43 (npCx43) at the lateral cell borders. This study was aimed to evaluate the efficacy of the immunohistochemical expression of Cx43 in the myocardium as an early ischemic marker in forensic autopsy. The study group consisted of 24 cases listing patients who died of ischemic heart disease (IHD) with severe coronary atherosclerosis that showed no myocardial pathology. Cases of sudden death of individuals from non-IHD (n=16) were used as controls. The survival times in both IHD and non-IHD groups were within 24 hours of the onset of angina symptoms, related injury, or the event for the cause of death. There was a statistically significant difference in tCx43 and npCX43 immunopositivity in the IHD group due to their expression patterns. In the IHD group, the redistribution of Cx43 expression from the intercalated discs to the lateral cell borders occurred more frequently than in the non-IHD group. In conclusion, the different expression patterns of tCx43 and npCx43 in the myocardium in IHD could be used as adjunctive ischemic markers.

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Fig. 1.
Immunopositivity for total connexin 43 (Cx43) was present in the myocardium only at the intercalated discs (intercalated disc pattern) in the case of the ischemic heart disease group. Performed using antibody Cx43 detection, with visualization using the polymer method, and H&E (×200).
kjlm-39-6f1.tif
Fig. 2.
Immunopositivity for non-phosphorylated connexin 43 (Cx43) was present in the myocardium at both the intercalated discs (intercalated disc pattern) and lateral cell borders (redistribution pattern) in the case of the ischemic heart disease group. Performed using antibody Cx43 detection, with visualization using the polymer method, and H&E (×200).
kjlm-39-6f2.tif
Fig. 3.
Immunopositivity of non-phosphorylated connexin 43 (Cx43) was present in the myocardium only at the lateral cell borders (redistribution pattern) in the case of the ischemic heart disease group. Performed using antibody Cx43 detection, with visualization using the polymer method, and H&E (×200).
kjlm-39-6f3.tif
Table 1.
Distribution of total connexin 43 (tCx43) and non-phosphorylated Cx43 (npCx43) expression in the myocardium of the ischemic heart disease group categorized by the pattern of immunopositivity
Type of Cx43 Pattern of immunopositivity P-value
Intercalated disc Redistribution to lateral cell border
tCx43 14 10 0.042
npCx43 07 17  
Table 2.
Distribution of total connexin 43 (tCx43) and non-phosphorylated Cx43 (npCx43) expression in the myocardium of the non-ischemic heart disease group categorized by the pattern of immunopositivity
Type of Cx43 Pattern of immunopositivity P-value
Intercalated disc Redistribution to lateral cell border
tCx43 10 06 0.077
npCx43 05 11  
Table 3.
Differences in total connexin 43 (tCx43) expression in the myocardium between the ischemic heart disease (IHD) and non-IHD group categorized by the pattern of immunopositivity
Group Pattern of immunopositivity P-value
Intercalated disc Redistribution to lateral cell border
IHD 14 10 0.792
Non-IHD 10 06  
Table 4.
Difference in non-phosphorylated connexin 43 (npCx43) expression in the myocardium between the ischemic heart disease (IHD) and non-IHD group categorized by the pattern of immunopositivity
Group Pattern of immunopositivity P-value
Intercalated disc Redistribution to lateral cell border
IHD 7 17 0.888
Non-IHD 5 11  
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