Gap junctions and chagas disease

Area of Science:

• Cardiovascular Biology
• Molecular Cardiology
• Parasitology

Background:

• Gap junction channels, primarily connexin43 (Cx43), are crucial for coordinated cardiac impulse propagation and synchronous contraction.
• Chagasic cardiomyopathy, caused by Trypanosoma cruzi infection, is characterized by impaired cardiac function and arrhythmias.
• Previous studies link arrhythmogenic cardiac diseases to reduced Cx43 expression.

Purpose of the Study:

• To investigate the impact of Trypanosoma cruzi infection on gap junction function and Cx43 expression in cardiac myocytes.
• To explore the transcriptomic changes in the heart during Chagas disease and their correlation with functional pathology.

Main Methods:

• Infection of cardiac myocytes with Trypanosoma cruzi in vitro.
• Immunofluorescence staining to assess gap junction and tight junction protein localization.
• Transcriptomic analysis of hearts from mouse models and infected cardiac myocytes.

Main Results:

• Trypanosoma cruzi infection significantly impairs synchronous contraction and leads to loss of gap junction immunoreactivity in cardiac myocytes.
• Changes in gap junction integrity were not observed for tight junction proteins.
• Transcriptomic studies revealed profound gene expression remodeling, particularly involving heart rhythm determinant genes.

Conclusions:

• Reduced Cx43 expression and impaired gap junction function are key features of Chagasic cardiomyopathy.
• Altered gene expression patterns contribute to the functional cardiac pathology observed in Chagas disease.
• The localized nature of Cx43 alterations suggests a potential spread of damage signals from infected to healthy cells, contributing to global cardiac dysfunction.