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Assessing Teratogenic Changes in a Zebrafish Model of Fetal Alcohol Exposure
Published on: March 20, 2012
Midazolam-induced developmental toxicity and neurotoxicity in zebrafish embryos: Insights from phenotypic,
Daohua Cao1, Xiaoyang Zhou2, Jiaolong Huang3
1Department of Anesthesiology, Xiangyang No.1 People's Hospital, Hubei University of Medicine, Xiangyang, 441000, China.
Abstract:
Midazolam (MDZ), a widely used short-acting benzodiazepine, has been linked to developmental and neurotoxic effects, yet its underlying molecular mechanisms during early development remain unclear. This study examined the impact of MDZ on zebrafish embryos and larvae through phenotypic, behavioural, and transcriptomic analyses. Embryos were exposed to MDZ at 2 and 4 mg/L from 6 to 96 h post-fertilisation (hpf). MDZ exposure significantly increased mortality, delayed hatching, and induced morphological abnormalities, indicating developmental toxicity. Neurotoxic effects included elevated apoptosis in both brain and heart regions, reduced spontaneous movement, and altered motor responses to light-dark stimulation. MDZ also decreased heart rate and body size, highlighting its detrimental impact on growth and cardiac function. Transcriptomic profiling identified 1496 DEGs (380 up-regulated and 1116 down-regulated) and revealed altered expression of genes involved in GABAergic synapse, PPAR signalling, cardiac muscle contraction, oestrogen and MAPK signalling, apoptosis, phototransduction, and osteoclast differentiation. These molecular changes likely underpin the observed developmental and neurotoxic outcomes. Notably, locomotor impairments persisted up to 5 days post-fertilisation (dpf), partially recovered by 7 dpf, and approached normalization by 10 dpf. Collectively, these findings underscore the developmental risks of MDZ exposure and provide molecular insights that may inform safer clinical practice.
Insights
Midazolam (MDZ) exposure causes developmental and neurotoxic effects in zebrafish, impacting growth, behavior, and gene expression. These findings highlight potential risks during early development.
Area of Science:
- Developmental toxicology
- Neuroscience
- Genomics
Background:
- Midazolam (MDZ), a short-acting benzodiazepine, is widely used but linked to developmental and neurotoxic effects.
- The molecular mechanisms of MDZ's impact on early development are not fully understood.
Purpose of the Study:
- To investigate the phenotypic, behavioral, and transcriptomic effects of MDZ exposure on zebrafish embryos and larvae.
- To elucidate the molecular pathways affected by MDZ during early development.
Main Methods:
- Zebrafish embryos were exposed to MDZ (2 and 4 mg/L) from 6 to 96 hours post-fertilization.
- Phenotypic, behavioral (locomotion, light-dark stimulation), cardiac function, and transcriptomic analyses were performed.
- Gene expression changes were analyzed using transcriptomic profiling.
Main Results:
- MDZ exposure led to increased mortality, delayed hatching, morphological abnormalities, and reduced body size.
- Neurotoxicity was evidenced by increased apoptosis in brain and heart, reduced movement, and altered responses to stimuli.
- Transcriptomic analysis revealed significant alterations in genes related to GABAergic synapse, cardiac function, apoptosis, and signaling pathways.
Conclusions:
- MDZ exposure poses significant developmental and neurotoxic risks during early zebrafish development.
- Altered gene expression in key pathways underlies the observed adverse effects.
- Findings provide molecular insights into MDZ's toxicity, informing safer clinical practices.
