Epidemiological data showed a positive correlation between GDM and the risk of autism spectrum disorder (ASD) in offspring, but specific mechanisms remain unclear. C57BL/6 female mice were fed with 60% HFD for 4 weeks, and then bred with healthy male mice. On gestational days 0.5 and 7.5, pregnant mice were injected with streptozocin (STZ, 110mg/kg, ip) to establish GDM model. Male offspring were selected for ASD related behavior at P42-P60. LC/MC was used to detect 5-hydroxytryptamine (5-HT) levels, while Western blot and immunofluorescence (IF) were used to detect functional indicators related to the dorsal raphe nucleus (DRN)5-HT system. Male GDM offspring showed impaired social function as evidenced by poor performance in three box test, and repetitive stereotypical behavior. LC/MS detection revealed a significant decrease in 5-HT levels in brain tissue and a significant increase in GDM offspring plasma. WB and IF showed that the abnormal differentiation of neural stem cells in DRN region in GDM offspring, with a significant decrease in the number of 5-HT positive neurons and 5-HT nerve fibers, and a significant downregulation of SYP and PSD95 protein levels. Ahi1, a highly susceptible gene to schizophrenia and ASD, as well as two key related proteins, B9D1 and Shh, were significantly downregulated. Treatment of meptazinol in GDM offspring increased Ahi1 mRNA and protein levels and effectively reversed the loss of 5-HT neurons in DRN and improved ASD-like behavioral signs. Notably, injection of AAV B9D1 shRNA into DRN, while decreasing B9D1 protein levels, attenuated the improvement of meptazinol on ASD-like behavioral changes in GDM offspring. Taken together, our studies suggested that GDM male offspring are susceptible to ASD, which may be related to the abnormal neural stem cells differentiation and maturation due to the impairment of Ahi1/ B9D1/Shh axis, resulting in the loss of 5-HT neurons in the DRN region.
X. Xiao: None. G. Qin: None.
The National Natural Science Foundation of China (82071734)
