# Reduced Dietary Protein Induces Changes in the Dental Proteome

## TL;DR

Reduced dietary protein during development changes tooth-related proteins but does not affect tooth size in mice.

## Contribution

Novel findings on altered immune and actin-based myosin proteins in tooth proteomes under low dietary protein.

## Key findings

- Low dietary protein alters expression of tooth-related and immune system proteins in mouse molars.
- Actin-based myosin proteins show significant differential expression under low dietary protein.
- Tooth size remains unchanged despite proteomic changes, indicating complex developmental responses.

## Abstract

Experimental studies have demonstrated that nutritional changes during development can result in phenotypic changes to mammalian cheek teeth. This developmental plasticity of tooth morphology is an example of phenotypic plasticity. Because tooth development occurs through complex interactions between manifold processes, there are many potential mechanisms which can contribute to a tooth's norm of reaction. Determining the identity of those mechanisms and the relative importance of each of them is one of the main challenges to understanding phenotypic plasticity. Quantitative proteomics combined with experimental studies allow for the identification of potential molecular contributors to a plastic response through quantification of expressed gene products. Here, we present the results of a quantitative proteomics analysis of mature upper first molars in Mus musculus from a controlled feeding experiment. Pregnant and nursing mothers were fed either a low‐dietary protein (10%) treatment diet or control (20%) diet. Low‐dietary protein was not associated with reduced molar size or skull length. However, expression of tooth‐related proteins, immune system proteins, and actin‐based myosin proteins were significantly altered in our low‐dietary protein proteomics sample. The differential expression of immune proteins along with systematic reduction in actin‐based myosin protein expression are novel discoveries for tooth proteomics studies. We propose that studies that aim to elucidate specific mechanisms of molar phenotypic plasticity should prioritize investigations into the relationships between IGF regulation and tooth development and actin‐based myosin expression and tooth development.

Low dietary protein (10%) from normal (20%) does change protein expression in tooth proteome and alter developmental pathways. Among the significant protein expressions changes are actin‐based myosins, tooth, and bone development proteins. Perplexingly tooth size is not altered, suggesting more nuanced phenotypic response to low dietary protein in early development.