# Mitochondrial movement in pancreatic alpha cells requires Miro2 and is regulated by glucose

## TL;DR

This study shows that glucose regulates mitochondrial movement in pancreatic alpha cells, and that Miro2 is essential for this process, affecting glucagon secretion.

## Contribution

The study identifies Miro2 as a novel regulator of mitochondrial motility in alpha cells and its role in glucose-dependent glucagon secretion.

## Key findings

- Glucose rapidly regulates mitochondrial motility and localization in alpha cells.
- Miro2 knockdown reduces mitochondrial motility and impairs glucose-induced inhibition of glucagon secretion.
- Miro2's role is specific to alpha cells, with no effect on insulin secretion or mitochondrial motility in other islet cells.

## Abstract

Under normal physiological conditions, glucagon is released from pancreatic alpha cells to elevate circulating glucose levels in response to hypoglycemia. In patients with type 2 diabetes, glucagon secretion is dysregulated, but the underlying mechanisms remain unclear. Several hypotheses have been suggested to explain the coupling of blood glucose sensing to electrical activity and glucagon secretion from alpha cells. Here, we show that glucose rapidly regulates mitochondrial motility and localization in alpha cells. Under conditions of low glucose, mitochondria are arrested in positions further from the nucleus, correlating with increased ATP/ADP in the sub-plasma membrane space. We also find that knockdown (KD) of Mitochondrial Rho GTPase 2 (Miro2), but not Miro1, reduces mitochondrial motility in alpha cells and impairs glucose-induced inhibition of glucagon secretion without effects on insulin secretion or mitochondrial motility in non-alpha islet cells. These findings highlight the significance of mitochondrial motility for alpha cell function and reveal fundamental differences between alpha and beta cells.