[Dityrosine administration induces myocardium injury and inflammatory response in mice]

Area of Science:

• Biochemistry and Molecular Biology
• Cardiovascular Research
• Oxidative Stress and Inflammation

Background:

• Oxidative stress contributes to cardiovascular diseases.
• Tyrosine oxidation products, such as dityrosine, are implicated in cellular damage.
• Understanding the specific role of these products in myocardial injury is crucial.

Purpose of the Study:

• To investigate the impact of oxidized tyrosine products (O-Tyr) and dityrosine (Dityr) on myocardial injury.
• To assess the effects of O-Tyr and Dityr on inflammatory responses in a mouse model.
• To determine the role of dityrosine as a major component in oxidized tyrosine-induced cardiac damage.

Main Methods:

• Thirty female Kunming mice were divided into three groups: control (saline), O-Tyr, and Dityr.
• Mice were gavaged with 320μg/kg body weight for 10 weeks.
• Assessed levels of protein oxidation (DT, AOPPs, 3-NT), lipid peroxidation (MDA), oxidative stress (T-AOC, GSH/GSSG), cardiac injury markers (CK, CK-MB, cTnI, Ca2+-ATPase), and inflammatory factors (CRP, TNF-α).
• Analyzed inflammatory response gene expression using Real-time quantitative PCR.

Main Results:

• O-Tyr and Dityr significantly increased markers of protein oxidation, lipid peroxidation, and oxidative stress in plasma and myocardium.
• Elevated levels of cardiac injury markers (CK, CK-MB, cTnI) and decreased Ca2+-ATPase activity were observed.
• Increased plasma levels of inflammatory markers (CRP, TNF-α) and up-regulated inflammatory gene expression were detected.

Conclusions:

• O-Tyr and Dityr promote myocardial protein oxidation and lipid peroxidation, inducing oxidative damage.
• These compounds may trigger myocardial tissue injury and inflammatory responses.
• Dityrosine plays a significant role in oxidized tyrosine-induced myocardial injury in mice.