Phenanthrene perturbs hematopoietic development and causes hematopoietic defects in zebrafish

Area of Science:

• Environmental toxicology
• Developmental biology
• Hematology

Background:

• Polycyclic aromatic hydrocarbons (PAHs) like phenanthrene (Phe) are environmental contaminants.
• Previous research indicates Phe causes cardiac and immune system toxicity.
• The effects of Phe on hematopoietic development in aquatic organisms remain largely unknown.

Purpose of the Study:

• To investigate the impact of chronic phenanthrene exposure on hematopoietic development in zebrafish (Danio rerio).
• To determine if Phe affects primitive and definitive hematopoiesis.
• To assess the potential ecological risks associated with Phe contamination.

Main Methods:

• Chronic exposure of zebrafish embryos and adults to varying concentrations of phenanthrene.
• Histological examination of kidney structure and peripheral blood.
• In situ hybridization to analyze the expression of hematopoietic marker genes (gata1, pu.1).
• Assessment of primitive erythrocyte circulation and hematopoietic stem cell generation.

Main Results:

• Phenanthrene induced structural damage to renal tubules and malformed erythrocytes.
• Phe exposure decreased myeloid cell proportion and primitive hematopoietic gene expression (gata1, pu.1).
• Impaired definitive hematopoiesis, increased PBI aberrations, and reduced hematopoietic stem cell generation were observed.

Conclusions:

• Phenanthrene exhibits significant hematopoietic toxicity in zebrafish, affecting both early and later stages of blood cell development.
• Observed effects include kidney damage, erythrocyte malformation, and altered myeloid cell populations.
• These findings highlight potential ecological risks posed by phenanthrene to aquatic life.