Recombinant human R-spondin 1(ARCA biopharma)

Roof plate-specific spondin 1 (R-spondin1, RSPO1) is a Wnt/β-catenin signaling pathway activator that binds with Wnt ligands to stimulate the Wnt/β-catenin signaling pathway, which is key to hair regeneration. However, it is not clear whether recombinant RSPO1 (rRSPO1) affects hair regeneration. Here, we treat C57BL/6 male mice with rRSPO1 and investigate the expression of the Wnt/β-catenin signaling pathway and the activation of hair follicle stem cells in the dorsal skin. The mouse skin color score and hair-covered area are determined to describe hair growth, and the skin samples are subjected to H&E staining, western blot analysis and immunofluorescence staining to evaluate hair follicle development and the expressions of Wnt/β-catenin signaling pathway-related proteins. We find that rRSPO1 activates mouse hair follicle stem cells (mHFSCs) and accelerates hair regeneration. rRSPO1 increases the hair-covered area, the number of hair follicles, and the hair follicle diameter and length. Moreover, rRSPO1 enhances the activity of Wnt/β-catenin signaling pathway-related proteins and the expressions of HFSC markers, as well as mHFSC viability. These results indicate that subcutaneous injection of rRSPO1 can improve hair follicle development by activating the Wnt/β-catenin signaling pathway, thereby promoting hair regeneration. This study demonstrates that rRSPO1 has the potential to treat hair loss by activating the Wnt/β-catenin signaling pathway.

R-spondin 1 (RSPO1) is a ligand for the intestinal stem cell (ISC) marker Lgr5 in the crypt, which functions to amplify canonical Wnt signaling to stimulate the division of ISCs. Despite the crucial role of recombinant human RSPO1 (rhRSPO1) in homeostasis and regeneration, little is known about RSPO1 among different species. Here, we cloned the porcine RSPO1 (pRSPO1) gene and obtained rpRSPO1 protein through the expression system of the recombinant Escherichia coli Rosetta (DE3) chemical competent cells. Using the in vitro IPEC-J2 model that combines cell proliferation evaluation approaches, we identified the rpRSPO1 activity in stimulating jejunal epithelial cells. And upon deoxynivalenol challenge in mice, we found that rpRSPO1 ameliorated their growth retardation and jejunal epithelial integrity. Importantly, the ISCs in the jejunum had greater proliferation and differentiation potential that was accompanied by Wnt/β-catenin pathway activation after rpRSPO1 modulation. Subsequently, the jejunal organoids expanded from these ISCs ex vivo presented robust growth advantages. And the rpRSPO1 was able to guide Wnt/β-catenin activity to increase ISC activity. Our work systematically demonstrates that rpRSPO1 facilitates ISC expansion by potentiating Wnt/β-catenin signaling during homeostasis and responding to deoxynivalenol perturbations.