Paneth cells inhibit intestinal stem cell proliferation through the bone morphogenic protein 7 pathway under...

Rotavirus (RV), a primary cause of diarrhea-related mortality in 2021, has been shown to damage intestinal epithelial cells while upregulating intestinal stem cells (ISCs) activities. ISCs within the crypt niche drive the continuous self-renewal of intestinal epithelium, preserving its barrier functions. Paneth cells secrete antimicrobial peptide and signaling molecules within the intestine crypt, thereby playing a crucial role in intestinal immune defense and providing ISCs functional support. However, the regulatory function of Paneth cells under pathological conditions, such as RV infection, remains unclear.

To determine the impact of RV infection on Paneth cells and how Paneth cells regulate ISCs during intestinal injury repair.

We constructed a reference genome for the RV enteric cytopathogenic human orphan virus strain and reanalyzed published single-cell RNA sequencing data to investigate Paneth cell responses to RV-induced intestinal injury. We derived Paneth-ISC communication networks using CellChat, tracked ISC differentiation with pseudotime analysis, and validated our findings in leucine-rich repeat-containing G protein-coupled receptor 5-enhanced green fluorescent protein-internal ribosomal entry site-Cre recombinase estrogen receptor variant 2 mice and organoids via immunofluorescence, flow cytometry, and reverse transcription quantitative polymerase chain reaction.

We found that RV directly infects Paneth cells, leading to a reduction in mature Paneth cells and an increase in kallikrein 1-high immature Paneth cells. Paneth-ISC communication was significantly enhanced. In particular, the bone morphogenic protein 7 (BMP7)-activin A receptor type 2B/BMP receptor type 1A-Smad pathway was upregulated post-infection, suggesting that Paneth cells suppress excessive ISC proliferation. Functional validation confirmed activation of this pathway.

Paneth cells regulate ISC proliferation during RV infection by activating BMP7 signaling, limiting excessive stem cell expansion and preserving crypt homeostasis for effective epithelial repair.