MMPs regulate both development and immunity in the tribolium model insect.

Area of Science:

• * Developmental Biology
• * Molecular Biology
• * Immunology

Background:

• * Matrix metalloproteinases (MMPs) are essential molecules for development and homeostasis.
• * In vivo functions of MMPs remain poorly understood despite extensive in vitro research.
• * Insect MMPs are evolutionarily conserved but their roles in vivo are largely unexplored.

Purpose of the Study:

• * To investigate the in vivo functions of insect MMPs and their inhibitors (TIMP, RECK) in development and immunity.
• * To establish the beetle Tribolium castaneum as a model organism for studying MMPs in vivo.
• * To explore the evolutionary conservation of MMP functions.

Main Methods:

• * RNA interference (RNAi) was used to silence MMP, TIMP, and RECK genes in Tribolium castaneum.
• * Phenotypic analysis of developmental defects and immune responses was performed.
• * Recombinant Tribolium MMP-1 was produced and purified to assess collagenolytic activity.

Main Results:

• * MMP-1 knockdown disrupted pupal morphogenesis, affecting antennae, eyes, wings, legs, and head.
• * MMP-1 and MMP-2 knockdown during embryogenesis led to tracheal and gut defects.
• * MMP-1 knockdown increased susceptibility to fungal infection, highlighting its role in innate immunity.
• * MMP expression and activity increased in hemocytes upon immune stimulation.
• * Recombinant Tribolium MMP-1 showed collagen IV degrading activity, similar to human MMP-19.

Conclusions:

• * MMPs play critical roles in insect embryogenesis, including tracheal and gut development.
• * MMPs are essential for pupal morphogenesis and innate immune defense in insects.
• * The study reveals conserved roles of MMPs in development and immunity across evolution.
• * Tribolium castaneum is a valuable model for in vivo MMP research.