Bisphenol analogue exposure at low concentrations modifies heart-brain functions and transcriptomics in zebrafish...

Area of Science:

• Environmental Toxicology
• Endocrinology
• Ecotoxicology

Background:

• Bisphenol A (BPA) is a common endocrine disruptor.
• Concerns exist regarding the environmental safety of BPA substitutes.
• Zebrafish larvae are a sensitive model for assessing chemical impacts.

Purpose of the Study:

• To investigate the physiological and molecular effects of low-concentration bisphenol analogues (BPS, BPF, BPAF) compared to BPA.
• To determine if these analogues induce motor-swimming deficits and associated electrophysiological changes.
• To identify molecular pathways affected by bisphenol exposure in zebrafish larvae.

Main Methods:

• OECD-compliant lethal dose (LD₅₀) determination for BPS, BPF, BPAF, and BPA.
• Assessment of morphological and developmental abnormalities below LD₅₀.
• In vivo optical mapping to analyze brain activity and heart rate.
• Transcriptomic analysis to identify gene expression changes.

Main Results:

• Low environmentally relevant concentrations of BPS, BPF, BPAF, and BPA induced significant motor-swimming changes.
• Increased high-frequency, low-amplitude brain activity was observed.
• BPF and BPAF exposure led to bradycardia.
• Eight specific genes related to heart-brain function, homeostasis, and immunity were downregulated by all tested bisphenols.

Conclusions:

• Low-level environmental exposure to bisphenol analogues can cause significant physiological and behavioral modifications in zebrafish larvae.
• Observed effects include altered motor function and heart-brain electrophysiology.
• These findings highlight potential risks to aquatic ecosystems and inform the One Health framework regarding endocrine disruptors.