Cardiac Troponin I Antibodies Induce Cardiomyocyte Damage and Alter Cell Morphology

Area of Science:

• Cardiovascular Research
• Immunology
• Cell Biology

Background:

• Heart-reactive autoantibodies (aAbs) are linked to heart failure progression and poor prognosis in various heart diseases.
• The precise mechanisms by which these autoantibodies affect cardiac health remain largely undetermined.

Purpose of the Study:

• To investigate the direct effects of autoantibodies against cardiac troponin I (anti-cTnI-aAbs) on cardiomyocytes.
• To elucidate the in vivo and in vitro impact of anti-cTnI-aAbs on cardiac function, inflammation, fibrosis, and apoptosis.

Main Methods:

• Induction of autoimmune response to cTnI in mice to generate anti-cTnI-aAbs.
• Evaluation of cardiac function, inflammation, fibrosis, and apoptosis in mice after 21 days.
• In vitro experiments exposing neonatal rat cardiomyocytes (NRCMs) to murine plasma containing anti-cTnI-aAbs.
• Morphological phenotyping of NRCMs using the C-MORE fluorescent image-based analysis workflow.

Main Results:

• Immunization with cTnI led to significant anti-cTnI-aAb production, myocardial inflammation, fibrosis, and reduced ejection fraction in mice.
• NRCMs treated with anti-cTnI-aAb-containing plasma exhibited decreased cell size, altered morphology, and increased cell death (p < 0.01 at 20% plasma).

Conclusions:

• Autoantibodies against cardiac troponin I directly interact with cardiomyocytes.
• These interactions likely contribute to adverse myocardial remodeling and may play a role in the progression of heart failure.