Generation of functional oligopeptides that promote osteogenesis based on unsupervised deep learning of protein IDRs

Deep learning(DL)is currently revolutionizing peptide drug development due to both computational advances and the substantial recent expansion of digitized biological data.However,progress in oligopeptide drug development has been limited,likely due to the lack of suitable datasets and difficulty in identifying informative features to use as inputs for DL models.Here,we utilized an unsupervised deep learning model to learn a semantic pattern based on the intrinsically disordered regions of~171 known osteogenic proteins.Subsequently,oligopeptides were generated from this semantic pattern based on Monte Carlo simulation,followed by in vivo functional characterization.A five amino acid oligopeptide(AIB5P)had strong bone-formation-promoting effects,as determined in multiple mouse models(e.g.,osteoporosis,fracture,and osseointegration of implants).Mechanistically,we showed that AIB5P promotes osteogenesis by binding to the integrinα5 subunit and thereby activating FAK signaling.In summary,we successfully established an oligopeptide discovery strategy based on a DL model and demonstrated its utility from cytological screening to animal experimental verification.

Bacteria-mediated tumor-targeted delivery of tumstatin(54-132)significantly suppresses tumor growth in mouse model by inhibiting angiogenesis and promoting apoptosis

Tumor growth is an angiogenesis-dependent process and accompanied by the formation of hypoxic areas.Tumstatin is a tumor-specific angiogenesis inhibitor that suppresses the proliferation and induces the apoptosis of tumorous vascular endothelial cells.VNP20009,an attenuated Salmonella typhimurium strain,preferentially accumulates in the hypoxic areas of solid tumors.In this study,a novel Salmonella-mediated targeted expression system of tumstatin(VNP-Tum5)was developed under the control of the hypoxia-induced J23100 promoter to obtain anti-tumor efficacy in mice.Treatment with VNP-Tum5 effectively suppressed tumor growth and prolonged survival in the mouse model of B16F10 melanoma.VNP-Tum5 exhibited a higher efficacy in inhibiting the proliferation and inducing the necrosis and apoptosis of B16F10 cells in vitro and in vivo compared with VNP(control).VNP-Tum5 significantly inhibited the proliferation and migration of mouse umbilical vascular endothelial cells to impede angiogenesis.VNP-Tum5 downregulated the expression of anti-vascular endothelial growth factor A,platelet endothelial cell adhesion molecule-1,phosphorylated phosphoinositide 3 kinase,and phosphorylated protein kinase B and upregulated the expression of cleaved-caspase 3 in tumor tissues.This study is the first to use tumstatin-transformed VNP20009 as a tumor-targeted system for treatment of melanoma by combining anti-tumor and anti-angiogenic effects.