Paternal mixed exposure to nicotine/ethanol/caffeine damaged cartilage quality in paternal/offspring rats and its differential glucocorticoid regulation mechanisms

Nicotine, ethanol, and caffeine are the most common exogenous substances in the men's living environment, but their effects on the cartilage quality in the father and offspring have not been reported. According to the average daily intake of adult men, we constructed a male rat model of paternal mixed exposure (PME) to low-dose nicotine (0.1 mg/(kg·day)), ethanol (0.5 g/(kg·day)), and caffeine (7.5 mg/(kg·day)) for 8 weeks. Then, the male rats mated with normal female rats to obtain offspring. The results showed that PME reduced the cartilage quality of paternal and offspring rats. Among them, the paternal cartilage was damaged by enhancing matrix degradation, while the offspring cartilage was damaged by reducing matrix synthesis. The cartilage damage in male offspring rats was more evident than in female offspring. It was further confirmed that differential GC regulation mechanisms were the main reasons for the intergenerational differential damage of paternal/offspring cartilage quality caused by PME. In addition, the androgen receptor (AR) and estrogen receptor beta (ERβ) mediated the sex difference of PME-induced fetal cartilage dysplasia by affecting the binding degree of GR/P300. This study provided a theoretical and experimental basis for guiding male healthy lifestyle and exploring early prevention and treatment strategies for paternal diseases.