Development of adeno-associated viral vectors targeting cardiac fibroblasts for efficient in vivo cardiac reprogramming

• Published in: Stem cell reports 2024-10, Vol.19 (10), p.1389-1398
• Main Authors: Nakano, Koji, Sadahiro, Taketaro, Fujita, Ryo, Isomi, Mari, Abe, Yuto, Yamada, Yu, Akiyama, Tatsuya, Honda, Seiichiro, French, Brent A., Mizukami, Hiroaki, Ieda, Masaki
• Format: Article
• Language: English
• Subjects: AAV; Animals; Cellular Reprogramming - genetics; Dependovirus - genetics; Fibroblasts - cytology; Fibroblasts - metabolism; Fibrosis; GATA4 Transcription Factor - genetics; GATA4 Transcription Factor - metabolism; Genetic Vectors - genetics; Humans; MEF2 Transcription Factors - genetics; MEF2 Transcription Factors - metabolism; Mice; Mice, Inbred C57BL; Myocardial Infarction - genetics; Myocardial Infarction - metabolism; Myocardial Infarction - therapy; Myocardium - cytology; Myocardium - metabolism; Myocytes, Cardiac - cytology; Myocytes, Cardiac - metabolism; Promoter Regions, Genetic; Regeneration; Reprogramming; T-Box Domain Proteins - genetics; T-Box Domain Proteins - metabolism; Transgenes
• ISSN: 2213-6711; 2213-6711
• DOI: 10.1016/j.stemcr.2024.08.002

Overexpression of cardiac reprogramming factors, including GATA4, HAND2, TBX5, and MEF2C (GHT/M), can directly reprogram cardiac fibroblasts (CFs) into induced cardiomyocytes (iCMs). Adeno-associated virus (AAV) vectors are widely used clinically, and vectors targeting cardiomyocytes (CMs) have been extensively studied. However, safe and efficient AAV vectors targeting CFs for in vivo cardiac reprogramming remain elusive. Therefore, we screened multiple AAV capsids and promoters to develop efficient and safe CF-targeting AAV vectors for in vivo cardiac reprogramming. AAV-DJ capsids containing periostin promoter (AAV-DJ-Postn) strongly and specifically expressed transgenes in resident CFs in mice after myocardial infarction (MI). Lineage tracing revealed that AAV-DJ-Postn vectors expressing GHT/M reprogrammed CFs into iCMs, which was further increased 2-fold using activated MEF2C via the fusion of the powerful MYOD transactivation domain (M-TAD) with GHT (AAV-DJ-Postn-GHT/M-TAD). AAV-DJ-Postn-GHT/M-TAD injection improved cardiac function and reduced fibrosis after MI. Overall, we developed new AAV vectors that target CFs for cardiac reprogramming. [Display omitted] •AAV-DJ vectors containing Postn promoter specifically expressed transgenes in CFs•AAV-DJ-Postn expressing cardiac reprogramming factors converted CFs into iCMs•Activated MEF2C promoted in vivo cardiac reprogramming with GATA4, HAND2, and TBX5•AAV-based in vivo cardiac reprogramming repaired infarcted mouse hearts Ieda and colleagues developed AAV vectors targeting CFs for in vivo cardiac reprogramming. In vitro and in vivo screening revealed that AAV-DJ vectors containing a CF-specific Postn promoter strongly and specifically expressed transgenes in resident CFs in mice after MI. AAV-based in vivo cardiac reprogramming converted resident CFs into iCMs, improved cardiac function, and reduced fibrosis after MI.