Detection of H2S using a novel fluorescent nanoprobe in plasma and tissue samples from ASD patients and model mice

Hydrogen sulfide (H2S) exerts its protective role in a variety of neurological diseases, but the related mechanisms of H2S in autism spectrum disorder (ASD) remain unclear. Toward a better understanding of the physiological role of H2S in ASD patients and mice, we designed a novel H2S detection fluorescent nanoprobe DNS-Az-M by encapsulating DNS-Az into an amphiphilic block copolymer DSPE-PEG2000. DNS-Az-M not only disperses well in aqueous solution and exhibits non-toxicity, but also achieves quantitative detection of H2S contents in biological samples of ASD patients and mice. We first found that the plasma H2S concentration in children with ASD was 12.14 +/- 5.03 mM through DNS-Az-M detection, which is remarkably lower than that in children without ASD (17.08 +/- 5.85 mM). The same phenomenon was observed in the ASD model BTBR mice. Furthermore, western blot and RT-PCR examination of BTBR mice hippocampus clearly revealed that CBS protein and CBS mRNA, as a key enzyme for H2S synthesis, had lower expression than that of B6 mice. This research provides a basis for the pathogenesis of ASD and outlines a promising strategy for targeted treatment of ASD.