Screening and characterization of pro-angiogenic peptides from Spirulina: computer simulation, experimental...

In this study, we identified novel pro-angiogenic peptides from Spirulina and elucidated their molecular mechanisms. Among the three fractions (A, B, and C) purified from the Spirulina protein extract by RP-HPLC, fraction B displayed the most potent pro-angiogenic activity. Through LC-MS/MS analysis, bioinformatics screening, and molecular docking, 20 candidate peptides were selected. In zebrafish models, five of these peptides, MFDCLR, MDMWGK, MNPGCR, MYDNFCK, and MPGLGR, significantly stimulated subintestinal vessel plexus (SIVP) growth and rescued intersegmental vessel (ISV) injury induced by Vatalanib (PTK787). Cellular experiments further showed that the five peptides reversed VEGFR tyrosine kinase inhibitor II (VRI)-induced impairments in proliferation, migration, and tube formation, with MDMWGK exhibiting the most pronounced pro-angiogenic effect. Moreover, the Matrigel plug assay confirmed that MDMWGK promoted extensive neovascularization in vivo. Subsequent mechanistic investigations revealed that the pro-angiogenic effect of MDMWGK was associated with activation of the VEGFA/PI3K-Akt signaling pathway, as evidenced by increased phosphorylation of PI3K and Akt. Collectively, this study provides an integrated screening strategy for discovering bioactive peptides from Spirulina and establishes a theoretical basis for developing pro-angiogenic agents.