Transcriptome analysis of molecular mechanism in inhibition of x-ray or carbon-ion induced lung fibrosis by Fc-Endostatin and its derived peptides

Endostatin is a naturally occurring 183-amino acid proteolytic fragment of collagen XVIII that localizes in the basement membrane around blood vessels. The anti-tumor properties of this protein have been extensively described, demarcating endostatin as an endogenous inhibitor of angiogenesis. Further, it supresses many signaling cascades such as pro-inflammatory NF-κB, coagulation and adhesion cascades. Yamaguchi et al. reported that endostatin via its C-terminal domain (E4 peptide) has elicit anti-fibrosis effects. However, the zinc binding domain has been previously confined to the N terminus (endostatin mP1 peptide) and was critical to numerous functions of the molecule. The present study aimed to better understand the impact of oligomerization (Fc-Endostatin) as well as N- vs. C-terminal fragments of endostatin (mP1, CE4) on modulating radiation-induced lung fibrosis. Mice were treated with Fc-endostatin (Fc-Endo), N-terminus endostatin peptide (mP1) or C-terminus endostatin E4 peptide (CE4) combined with photon 20 Gy or carbon-ions 12.5 Gy whole thoracic irradiation