# Molecular Mechanism of Metformin Regulating the Regeneration of Planarian Dugesia japonica Through miR-27b

## TL;DR

This study shows how metformin promotes regeneration in planarians by regulating a specific miRNA and its target gene.

## Contribution

The study identifies the DjmiR-27b/DjPax6 axis as a novel mechanism through which metformin influences regeneration.

## Key findings

- 1 mM metformin significantly promotes planarian eyespot regeneration.
- Metformin regulates DjPax6 expression via DjmiR-27b.
- DjmiR-27b and DjPax6 are expressed throughout the planarian body.

## Abstract

Metformin is one of the most commonly used medications to treat type 2 diabetes. In addition to lowering blood sugar, it can also promote the regeneration of certain organs or tissues. Planarian Dugesia japonica, with its remarkable regenerative capacity, has become an important model organism for studying pharmacology and regenerative medicine. Planarian eyespot regeneration involves precise tissue regeneration via mechanisms like cell proliferation, differentiation, and gene regulation following body damage. Experiments on planarian eyespot regeneration have confirmed that 1 mM metformin significantly promotes regeneration. Through analysis of the regenerating planarian miRNA database and the metformin-treated transcriptome database, combined with target gene prediction by TargetScan, the DjmiR-27b/DjPax6 axis was finally determined as the research focus. qPCR showed that metformin significantly affects the expression levels of DjmiR-27b and DjPax6. DjPax6 was identified as the target gene of DjmiR-27b through dual luciferase reporter gene analysis. Functional experiments revealed that metformin regulates the expression of DjPax6 via DjmiR-27b, thereby influencing the regeneration of planarian eyespots. In situ hybridization showed that both DjmiR-27b and DjPax6 are expressed throughout the entire body. This study reveals the molecular mechanism of metformin regulating planarian regeneration through miRNA, providing further insights into its role in the field of regeneration.