# Nutrients and Metabolites as Signalling Molecules in Osteoclasts

## TL;DR

This paper reviews how nutrients and metabolites act as signaling molecules in osteoclasts, influencing their formation and function through metabolic and epigenetic pathways.

## Contribution

The paper introduces the novel idea that metabolites regulate osteoclasts via signaling roles, beyond their traditional roles in energy and biosynthesis.

## Key findings

- Nutrients like glucose and amino acids influence osteoclastogenesis through metabolic and epigenetic pathways.
- Metabolites such as succinate and α-ketoglutarate modulate osteoclast function by interacting with nutrient sensors and transcriptional regulators.
- Understanding metabolite-driven signaling could lead to new treatments for bone diseases.

## Abstract

This review aims to highlight the emerging concept that nutrients and metabolites act not merely as energy sources or biosynthetic precursors, but also as instructive signalling molecules in osteoclasts. While much is known about transcriptional and genetic pathways governing osteoclast differentiation and function, comparatively little attention has been given to the role of cellular metabolism and nutrient-sensing mechanisms. This review seeks to categorise key metabolites based on their signalling roles and examine how they influence osteoclastogenesis through metabolic, epigenetic, and inflammatory pathways.

Recent studies have demonstrated that nutrients such as glucose, amino acids, and lipids, along with their intermediary metabolites such as succinate, itaconate, α-ketoglutarate (αKG), S-adenosylmethionine (SAM), and acetyl-CoA, regulate osteoclast formation and function by modulating signalling cascades and epigenetic landscapes. These molecules engage nutrient sensors (e.g., aldolase, mTORC1, CPT1) and transcriptional regulators (e.g., NFATc1, PPARs), while also affecting chromatin structure, inflammatory responses, and organelle dynamics.

Osteoclast metabolism is tightly linked to cellular fate through nutrient-sensing and metabolite-driven signalling. Elucidating these pathways will reshape our understanding of osteoclast regulation and help identify new metabolic targets for treating bone diseases.