Intracellular pH dynamics regulates intestinal stem cell lineage specification

Abstract

Intracellular pH dynamics is increasingly recognized to regulate myriad cell behaviors. We report a finding that intracellular pH dynamics also regulates adult stem cell lineage specification. We identify an intracellular pH gradient in mouse small intestinal crypts, lowest in crypt stem cells and increasing along the crypt column. Disrupting this gradient by inhibiting H+ efflux by Na+/H+ exchanger 1 abolishes crypt budding and blocks differentiation of Paneth cells, which are rescued with exogenous WNT. Using single-cell RNA sequencing and lineage tracing we demonstrate that intracellular pH dynamics acts downstream of ATOH1, with increased pH promoting differentiation toward the secretory lineage. Our findings indicate that an increase in pH is required for the lineage specification that contributes to crypt maintenance, establishing a role for intracellular pH dynamics in cell fate decisions within an adult stem cell lineage.

Intracellular pH regulates β-catenin with low pHi increasing adhesion and signaling functions

“…This fits with prior work showing β-catenin/TCF4 complexes are transcriptionally active but that plakoglobin/TCF4 complexes are unable to bind DNA (Roura et al, 1999;Simcha et al, 1998). Our data show that pHi directly regulates βcatenin signaling and transcriptional activity in the absence of Wnt pathway activation and indicates that pH-dependent regulation of β-catenin signaling may reinforce stem cell phenotypes previously associated with low pHi (Liu et al, 2023) and high Wnt signaling (Nusse, 2008).…”

“…Spatiotemporal pHi dynamics regulate cell processes like differentiation (Ulmschneider et al, 2016), cell migration (Denker and Barber, 2002), cell cycle progression (Spear and White, 2023), and cell fate determination (Liu et al, 2023).…”

“…Spatiotemporal pHi dynamics regulate cell processes like differentiation (Ulmschneider et al, 2016), cell migration (Denker and Barber, 2002), cell cycle progression (Spear and White, 2023), and cell fate determination (Liu et al, 2023). While low pHi is required to maintain the adult stem cell niche (Liu et al, 2023; Ulmschneider et al, 2016) and transient increases in pHi are required for successful differentiation (Ulmschneider et al, 2016), the molecular drivers of these pHi-dependent processes are unknown.…”

“…Spatiotemporal pHi dynamics regulate cell processes like differentiation (Ulmschneider et al, 2016), cell migration (Denker and Barber, 2002), cell cycle progression (Spear and White, 2023), and cell fate determination (Liu et al, 2023). While low pHi is required to maintain the adult stem cell niche (Liu et al, 2023; Ulmschneider et al, 2016) and transient increases in pHi are required for successful differentiation (Ulmschneider et al, 2016), the molecular drivers of these pHi-dependent processes are unknown. Recent work has identified β-catenin as a pH-sensitive protein with decreased abundance at high pHi driven by pH-dependent binding of β-catenin to the E3 ligase, β-transducin repeat containing protein (β-TrCP) (White, Katharine A.; Grillo-Hill, Bree K.; Esquivel, Mario; Peralta, Jobelle; Bui, Vivian N.; Chire, Ismahan; Barber, 2018).…”

Bacillus amyloliquefaciens SC06 Relieving Intestinal Inflammation by Modulating Intestinal Stem Cells Proliferation and Differentiation via AhR/STAT3 Pathway in LPS-Challenged Piglets

“…These findings showed that SC06 could enhance intestinal mucosa integrity by encouraging ISC regeneration. Goblet cells are specialized intestinal epithelial cells that are crucial for maintaining bacterial defense and mucosal integrity. − Our findings suggest that SC06 also increased the proportion of the goblet in the ileum. Enterocyte cells and absorptive cells are integral constituents of intestinal cells and serve a pivotal function in the regulation of digestion, appetite, intestinal motility and metabolism .…”