PAPP-A-Specific IGFBP-4 Proteolysis in Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes

• Published in: International journal of molecular sciences 2023-05, Vol.24 (9), p.8420
• Main Authors: Adasheva, Daria A, Lebedeva, Olga S, Goliusova, Daria V, Postnikov, Alexander B, Teriakova, Maria V, Kopylova, Irina V, Lagarkova, Maria A, Katrukha, Alexey G, Serebryanaya, Daria V
• Format: Article
• Language: English
• Subjects: Analysis; Binding proteins; Bioavailability; Biological activity; Blood proteins; Cardiomyocytes; Cardiovascular diseases; Cell lines; Cell surface; Cells; Congestive heart failure; Coronary heart disease; Coronary vessels; Epitopes; Ethylenediaminetetraacetic acid; Ethylenediaminetetraacetic acids; Fibroblasts; Flow cytometry; Growth factors; Heart; Heart cells; Humans; Induced Pluripotent Stem Cells - metabolism; Insulin-Like Growth Factor Binding Protein 4 - metabolism; Insulin-like growth factor I; Insulin-like growth factor II; Insulin-like growth factor-binding protein 4; Insulin-like growth factors; Ischemia; Metalloproteinase; Myocytes, Cardiac - metabolism; Physiological aspects; Physiology; Pluripotency; Pregnancy; Pregnancy-Associated Plasma Protein-A - metabolism; Protein A; Protein binding; Proteins; Proteolysis; Secretome; Smooth muscle; Stem cells
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms24098420

The insulin-like growth factors IGF-I and IGF-II-as well as their binding proteins (IGFBPs), which regulate their bioavailability-are involved in many pathological and physiological processes in cardiac tissue. Pregnancy-associated plasma protein A (PAPP-A) is a metalloprotease that preferentially cleaves IGFBP-4, releasing IGF and activating its biological activity. Previous studies have shown that PAPP-A-specific IGFBP-4 proteolysis is involved in the pathogenesis of cardiovascular diseases, such as ischemia, heart failure, and acute coronary syndrome. However, it remains unclear whether PAPP-A-specific IGFBP-4 proteolysis participates in human normal cardiomyocytes. Here, we report PAPP-A-specific IGFBP-4 proteolysis occurring in human cardiomyocytes derived from two independent induced pluripotent cell lines (hiPSC-CMs), detected both on the cell surface and in the cell secretome. PAPP-A was measured by fluoroimmune analysis (FIA) in a conditioned medium of hiPSC-CMs and was detected in concentrations of up to 4.3 ± 1.33 ng/mL and 3.8 ± 1.1 ng/mL. The level of PAPP-A-specific IGFBP-4 proteolysis was determined as the concentration of NT-IGFBP-4 proteolytic fragments using FIA for a proteolytic neo-epitope-specific assay. We showed that PAPP-A-specific IGFBP-4 proteolysis is IGF-dependent and inhibited by EDTA and 1,10-phenanthroline. Therefore, it may be concluded that PAPP-A-specific IGFBP-4 proteolysis functions in human normal cardiomyocytes, and hiPSC-CMs contain membrane-bound and secreted forms of proteolytically active PAPP-A.