Regenerative growth is impacted by TCDD: gene expression analysis reveals extracellular matrix modulation

Area of Science:

• Zebrafish fin regeneration
• Toxicology
• Molecular biology

Background:

• Adult zebrafish possess remarkable caudal fin regeneration capabilities.
• Regeneration involves wound healing, blastema formation, and tissue regrowth.
• Exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) inhibits zebrafish fin regeneration.

Purpose of the Study:

• To investigate the molecular mechanisms by which TCDD disrupts zebrafish fin regeneration.
• To identify genes and pathways affected by TCDD exposure during the early stages of fin regeneration.

Main Methods:

• Adult male zebrafish were exposed to TCDD or vehicle.
• Caudal fins were amputated, and regeneration was monitored.
• mRNA abundance was analyzed using microarray and quantitative real-time PCR at 1, 3, and 5 days post-amputation (dpa).

Main Results:

• Fin regeneration involves significant alterations in nearly 900 gene expressions between 1 and 5 dpa.
• TCDD exposure altered the expression of 370 genes.
• TCDD affected aryl hydrocarbon responsive genes and those involved in extracellular matrix metabolism, suggesting impaired cellular differentiation regulated by Sox9b.

Conclusions:

• TCDD exposure significantly perturbs gene expression profiles during zebrafish fin regeneration.
• The identified molecular changes indicate impaired wound healing, cellular differentiation, and extracellular matrix regulation.
• Sox9b may play a crucial role in mediating TCDD's inhibitory effects on fin regeneration.