TY - JOUR T1 - Serum albumin maintains Wnt water-solubility and activity JF - bioRxiv DO - 10.1101/2023.01.22.525087 SP - 2023.01.22.525087 AU - Joo Hye Yeo AU - Soon Sung Kwon AU - Jiyeon Chae AU - Ines Kusen AU - Jaeeun Han AU - Ju Yeon Lim AU - Jae-Ho Cheong AU - Taeil Kim AU - Yang Ouk Jung AU - Chul Hoon Kim AU - Jinu Lee Y1 - 2023/01/01 UR - http://biorxiv.org/content/early/2023/01/23/2023.01.22.525087.abstract N2 - Wnt proteins regulate adult tissue homeostasis and repair by driving stem cell self-renewal and differentiation. High-performance Wnt preparations have enormous therapeutic potential, especially alongside various stem cell technologies. Currently, most of these Wnt preparations contain FBS or the detergent CHAPS to maintain Wnt solubility and activity. Recently, afamin was identified as a serum factor that solubilizes Wnt3a in conditioned media (CM), obviating the requirement for animal sera. Here, we report serum albumin (SA) is required for afamin-mediated solubilization of Wnt3a in CM. Moreover, SA-mediated solubilization of purified Wnt3a in tubes does not require afamin. This means conventional CHAPS-Wnt3a preparations can be modified into SA-purified Wnt3a (SA-pWnt3a) preparations by exchanging CHAPS for SA through dialysis. SA-pWnt3a preparations effectively promote the growth of human stem cell organoids. These data suggest SA as a physiological factor for maintaining Wnt3a activity in therapeutic applications.Competing Interest StatementC.H.K. is supported in part by a collaborative research grant from Interpark Bio Convergence Corp. ER -