Modeling human protein aggregation cardiomyopathy using murine induced pluripotent stem cells

Area of Science:

• Biochemistry
• Cardiovascular Biology
• Stem Cell Biology

Background:

• Mutations in alpha B-crystallin (CryAB) are linked to human myopathies.
• Transgenic mice expressing R120GCryAB exhibit myopathic features like protein aggregates and cardiomyopathy.
• Induced pluripotent stem cells (iPSCs) offer a novel approach for disease modeling.

Purpose of the Study:

• To investigate the relevance of iPSC-derived cardiomyocytes for modeling aggregation-prone disorders.
• To determine if iPSC-derived cardiomyocytes from R120GCryAB mice recapitulate disease hallmarks.
• To establish a new in vitro model for studying CryAB-linked myopathies.

Main Methods:

• Generation and validation of iPSC lines from transgenic (TG) and non-TG mice.
• Differentiation of iPSCs into cardiomyocytes.
• Analysis of CryAB protein aggregation, cellular size, and gene expression (e.g., fetal genes).

Main Results:

• TG iPSC-derived cardiomyocytes displayed perinuclear CryAB aggregates.
• High-level R120GCryAB expression correlated with significantly larger cardiomyocyte size.
• Increased expression of fetal genes indicated activation of the hypertrophic genetic program in TG cardiomyocytes.

Conclusions:

• Differentiation of R120G iPSCs into cardiomyocytes successfully recapitulates protein aggregation and cellular hypertrophy in vitro.
• This iPSC-derived cardiomyocyte model effectively mirrors key pathognomonic hallmarks of CryAB myopathies.
• The study provides a valuable cell model for future mechanistic and therapeutic investigations of these disorders.