Intracellular crowding as mechanoregulator of intestinal organoid growth via modulating Wnt-receptor complex phase transition*

Enormous amounts of essential intracellular events are crowdedly packed inside picoliter-sized cellular space. However, the significance of the physical properties of cells remains underappreciated due to a lack of evidence of how they impact cellular functionalities. Here, we show that the degree of intracellular crowding serves as a mechanoregulator of intestinal organoid growth via modulating Wnt/β-catenin signaling. Intracellular crowding varies upon stimulation by different types of extracellular physical and mechanical cues, and leads to a significant enhancement of Wnt/β-catenin signaling by promoting phase transition of LRP6 receptor complex. By enhancing intracellular crowding using either osmotic or mechanical compression, we show that expansion of intestinal organoids was facilitated through elevated Wnt/β-catenin signaling and greater intestinal stem cells (ISCs) self-renewal. Our results provide an entry point for understanding how intracellular crowdedness functions as a mechanotransducer linking extracellular physical cues with intracellular signaling, and potentially facilitate the design of engineering approaches for expansion of stem cells and organoids.