# Hypoxia-inducible factor-1 alpha modulates muscle growth and the molting process through its regulation of glycolysis in Neocaridina davidi

## TL;DR

This study explores how HIF-1α regulates muscle growth and molting in shrimp through glycolysis, revealing a Warburg-like effect during pre-molting.

## Contribution

The study identifies HIF-1α as a key regulator of glycolysis during shrimp molting and muscle growth.

## Key findings

- HIF-1α expression is elevated during specific molting subphases, correlating with muscle proliferation.
- Knockdown of HIF-1α inhibits glycolytic enzyme expression and disrupts molting and muscle growth.
- Gill removal and tumor cell-free extracts influence HIF levels, potentially mimicking hypoxic conditions.

## Abstract

Molting is a characteristic feature of crustaceans, closely associated with their growth. Following the molting process, crustaceans experience an explosive increase in muscle mass; however, the specific mechanisms underlying this rapid growth remain to be fully elucidated. This study aims to analyze the mechanisms of accelerated muscle proliferation from the perspective of sugar metabolism. The relationship between glycolysis and HIF-1α expression in shrimp muscle during different molting stages was investigated, revealing decreased glucose levels and elevated lactate concentrations in the D0-1 subphase. These findings suggest a Warburg-like effect occurring during pre-molting. Notably, HIF-1α expression was consistently higher in the D0-1, D2, and D3 subphases compared to other stages, indicating its pivotal role in muscle cell proliferation and molting regulation. Knockdown of HIF-1α significantly reduced the expression of glycolytic enzymes and inhibited both muscle growth and molting processes. Additionally, this study explored the effects of gill removal on HIF-1α expression; it was found that mechanical injury increased HIF levels, potentially mimicking hypoxic conditions. Specifically, tumor cell-free extracts were observed to enhance the molting rate, likely linked to upregulation of HIF expression. These results imply that such extracts may create a favorable environment for molting by influencing physiological mechanisms associated with HIF activity, thereby facilitating the molting process in shrimp. Overall, these findings suggest a complex interplay between glycolysis, HIF expression, and physiological processes during shrimp molting while highlighting the potential role of HIF as a regulator within these metabolic pathways.