Real-time in situ observation of P53-mediated cascade activation of apoptotic pathways with nucleic acid multicolor fluorescent probes based on symmetrical gold nanostars

T-2 toxin,one of the most dangerous natural pollutants,induces apoptosis through multiple pathways.Amongst,P53 mediated apoptosis pathway,an important collection of molecules,plays a key role in cell vital activity.Real-time monitoring of upstream and downstream activation relationships of P53 mRNA,Bax mRNA,and cytochrome c(Cyt c)in signaling pathways is of great significance for understanding the apoptotic machinery in human physiology.In this work,a novel nucleic acid multicolor fluorescent probe,based on silica-coated symmetric gold nanostars(S-AuNSs@SiO_(2)),was developed for highly sensitive in situ real-time imaging of P53 mRNA,Bax mRNA,and Cyt c during T-2 toxin-induced apoptosis.The nucleic acid chains modified with carboxyl groups were modified on the surface of S-AuNSs@SiO_(2)by amide reaction.The complementary chains of targeted mRNA and the aptamer of targeted Cyt c were modified with different fluorophores,respectively,and successfully hybridized on S-AuNSs@SiO_(2)surface.When targets were present,the fluorescent chains bound to the targets and detached from the material,resulting in the quenched fluorescence being revived.The probes based on S-AuNSs showed excellent performance is partly ascribed to the presence of 20 symmetric“hot spots”.Notably,the amide-bonded probe exhibited excellent anti-interference capability against biological agents(nucleases and biothiols).During the real-time fluorescence imaging of T-2 toxin-induced apoptosis,the corresponding fluorescence signals of P53 mRNA,Bax mRNA,and Cyt c were observed sequentially.Therefore,S-AuNSs@SiO_(2)probe not only provides a novel tool for real-time monitoring of apoptosis pathways cascade but also has considerable potential in disease diagnosis and pharmaceutical medical.