Decrypting pH

Think pH and you might remember experimenting with acids and alkalis at school. Your body plays with pH too, making subtle changes to control cell behaviour. Researchers now examine how pH affects adult gut stem cells. Mice were injected with a virus genetically engineered with a fluorescent pH marker. Fluorescence microscopy of gut organoids (pictured) made from these mice revealed a pH gradient in cells that make up crypts – structures that line the gut. At the bottom of crypts, where stem cells live, the pH was lowest; it increased upwards. Disrupting this gradient with a drug (bottom) stopped crypt budding, the creation of new crypts to maintain the gut lining, as compared with untreated organoids (top). It also prevented cells that regulate stem cells, Paneth cells (yellow), from maturing. Consequently, stem cells failed to mature into secretory cells. This reveals the importance of intracellular pH in regulating adult stem cells.

Written by Lux Fatimathas

Lux Fatimathas

Writer

Having pursued science through a career in research, communications and publishing, she is currently a writer and editor for a healthcare marketing agency and also juggles freelance science writing.

• Image adapted from work by Yi Liu and colleagues
• Department of Cell and Tissue Biology, University of California San Francisco, San Francisco, CA, USA
• Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)
• Published in Nature Communications, June 2023