Mucin-fused myeloid-derived growth factor (MYDGF164) exhibits a prolonged serum half-life and alleviates fibrosis in chronic kidney disease.

Abstract

Although no effective therapy is available to stop or reverse CKD progression targeting its key feature, the loss of peritubular capillaries (PTCs) leading to interstitial fibrosis, myeloid-derived growth factor (MYDGF) with tissue-repairing activities enlightens its therapeutic potential for CKD. However, the extremely short circulatory lifetime (15 min) restricts its application. We selected a tandem repeated (TR) region of human CD164 as a carrier to fuse with MYDGF and then investigated for biophysical and pharmacokinetic changes. The MYDGF164 bioactivities were validated in HUVECs and then assessed in HK-2 cells. We also investigated its efficacy in unilateral ureteral obstruction (UUO)-treated mice and in adenine-induced CKD rats. MYDGF164 was modified with sialoglycans, improving its resistance to serum proteases and increasing its hydrodynamic radius. The half-life of MYDGF164 was significantly prolonged but retained its original cell proliferation, anti-apoptosis, and tubulogenesis activities. It selectively stimulated the proliferation in endothelial and epithelial cells through phosphorylating MAPK1/3. MYDGF164 alleviated capillary rarefaction, hypoxia, renal fibrosis, and tubular atrophy in UUO mice and in adenine-induced CKD rats. MYDGF164 restored renal function, with normalized creatinine and urea levels in adenine-induced CKD rats. Histopathology and immunohistochemistry revealed that MYDGF164 protection was related to its cell-proliferative, anti-apoptosis, and angiogenesis activities. This study is the first successful example of using a tandem repeated region of hCD164 as a cargo protein for the pharmacokinetic improvement of therapeutic proteins. Our findings highlight the potential of MYDGF164 in alleviating renal fibrosis in CKD.