0
Article ? AI-assigned paper type based on the abstract. Classification may not be perfect — flag errors using the feedback button. Tier 2 ? Original research — experimental, observational, or case-control study. Direct primary evidence. Nanoplastics Remediation Sign in to save

Polystyrene nanoplastics disrupted cholesterol/testosterone homeostasis via Smurf1-dependent FTO degradation

Food and Chemical Toxicology 2026
Jianhui Liu, Shaofei Su, Ruixia Liu, Shuanghua Xie, Chenghong Yin, E M Zhang, Lihua Ren

Summary

Researchers found that early-life exposure to polystyrene nanoplastics lowers testosterone in male rats by disrupting cholesterol uptake in testicular cells through a molecular chain in which nanoplastics upregulate the protein Smurf1, which degrades FTO, ultimately reducing the cholesterol receptors needed for testosterone synthesis.

Polymers

Polystyrene nanoplastics (PS-NPs) exposure can induce testosterone decline, but the underlying mechanism remains elusive. In the present study, prepubertal PS-NPs exposure caused testicular injury and reduced testosterone levels. RNA sequence analysis indicated that cholesterol homeostasis and PPARα signaling pathways may be involved in the disruption of testosterone biosynthesis. Compared with the control group, exposure to PS-NPs resulted in no significant change in serum cholesterol levels but a marked reduction in testicular and TM3 cell cholesterol levels. Western blot analysis revealed prepubertal PS-NPs exposure activated the PPARα pathway, with a consequent significant downregulation in the expression of cholesterol uptake receptors SCARB1 and LDLR. Using immunoprecipitation, we found that PS-NPs disrupted cholesterol uptake by facilitating the ubiquitin-dependent degradation of FTO. Ultimately, we observed that PS-NPs exposure markedly upregulated Smurf1 protein expression. Knocking down Smurf1 repressed PS-NPs caused the ubiquitin-dependent degradation of FTO protein, thereby alleviating cholesterol and testosterone decline. Overall, our study elucidated a novel mechanism by which prepubertal PS-NPs exposure disrupted cholesterol/testosterone homeostasis via Smurf1-dependent FTO degradation.

Share this paper