Sequential changes in autophagy in diabetic cardiac fibrosis

Area of Science:

• Cardiovascular Biology
• Metabolic Disease Research
• Cellular Mechanisms

Background:

• Autophagy's role in cardiac fibrosis is debated, with uncertainty regarding its acceleration or amelioration of the condition.
• Diabetic cardiomyopathy is a significant complication characterized by cardiac fibrosis and impaired systolic function.

Purpose of the Study:

• To investigate the role of autophagy in the development and progression of cardiac fibrosis in a rat model of diabetes.
• To determine whether autophagy accelerates or ameliorates diabetic cardiac fibrosis.

Main Methods:

• A diabetic rat model was established using a high-fat diet and streptozotocin.
• Cardiac fibrosis was assessed via Masson's trichrome staining and collagen mRNA expression (type I and III).
• Autophagy markers, including Beclin 1 mRNA, LC3-II/LC3-I ratio, and P62 protein levels, were evaluated using RT-qPCR and Western blotting.

Main Results:

• Diabetic rats exhibited progressive cardiac fibrosis and reduced systolic function over 7 months.
• Upregulation of collagen type I and III mRNA, Beclin 1 mRNA, and increased LC3-II/LC3-I ratio were observed.
• A decrease in P62 protein content and aggravation of fibrosis and autophagy markers over time were noted.

Conclusions:

• Autophagy markers were correlated with cardiac fibrosis progression in diabetic rats.
• The findings suggest that autophagy plays a synergistic role in accelerating diabetic cardiac fibrosis.
• Autophagy may exacerbate cardiac dysfunction in the context of diabetes.