The role of polypeptide PDTLN1 in suppression of PI3K/AKT signaling causes cardiogenetic disorders in vitro and in vivo

Aims: A new polypeptide, PDTLN1, derived from the human Talin-1 protein, which is highly expressed in both myocardial tissue and maternal peripheral blood of aborted fetuses with congenital heart disease (CHD). However, its role in cardiac developmental disorders has not been disclosed till now. In the present study, we aim to assess the functions of PDTLN1 in heart development of zebrafish and cellular viability, proliferation, and apoptosis of P19 cells. Main methods: Cellular viability was assessed by Cell Counting Kit-8, the EdU Kit was used to evaluate cellular proliferation, and apoptosic rate of P19 was examined using FITC Annexin-V staining followed by flow cytometry. The zebrafish embryos were divided into three groups: PEP group and NC group were microinjected with polypeptides, WT group without any intervention. The protein expression of PI3K/AKT were evaluated by western blotting. Key findings: PDTLN1 could suppress the proliferation, and facilitate apoptosis. PDTLN1 caused abnormal heart development of zebrafish embryos and the PDTLN1 (50 μM)-injected group showed an aberrant expression pattern of vmhc, amhc and cmlc2. Compared to the CTL group and SC79 group of P19 cells, the PDTLN1 group had a lower phosphorylated PI3K/AKT proteins level, decreased cellular viability and lower proliferation activity. Significance: PDTLN1 caused cardiac developmental defects in zebrafish, inhibited cellular viability, proliferation, and promoted apoptosis of P19 cells via suppressing the PI3K/AKT signaling pathway. Our findings provide a fresh perspective on the functional mechanism of human-derived peptides and may promote novel diagnostic biomarkers detection and therapeutic targets in CHD.