Racing to Stay Put: How Resident Microbiota Stimulate Intestinal Epithelial Cell Proliferation
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Purpose of Review
In this review, we describe a shared requirement for resident microbiota to stimulate intestinal epithelial cell proliferation revealed in germ-free mice, zebrafish, and fruit flies. We seek to understand the extent to which these hosts respond to their microbiota through shared mechanisms, reflecting ancient animal epithelial tissue adaptations to microbial coexistence, versus through host-specific specializations.
We find examples of host-specific microbial pro-proliferative stimuli, but across hosts, these stimuli are often sensed via innate immune pathways involving Myd88 and NFkappaB. These sensing pathways appear to stimulate a diversity of conserved effectors of epithelial proliferation and repair including reactive oxygen species, Beta-catenin, Jak/Stat, and mTOR signaling.
We conclude that diverse microbial signals are sensed through host innate immune pathways to induce conserved programs of epithelial proliferation and repair. Harnessing these responses will provide new avenues for treating underdeveloped or injured epithelia.
KeywordsIntestinal epithelial proliferation Germ-free Microbiota Mouse Zebrafish Fruit fly
Compliance with Ethical Standards
Conflict of Interest
The authors declare that they have no conflict of interest.
Human and Animal Rights and Informed Consent
This article does not contain any studies with human or animal subjects performed by any of the authors.
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