Mechanism of Saikosaponin D Mediating Autophagy in ICCs by Regulating CaMKKβ/AMPK Signaling Pathway
Objectives To explore the effect and mechanism of saikosaponin D on cellular autophagy of ICCs by regulating the CaMKKβ/AMPK signaling pathway.Methods Rat primary ICCs cells were isolated and stimulated with glutamate to construct an autophagy model.The Ca2+level was detected by immunofluorescence.Primary ICCs cells were divided into control group,model group,model+saikosaponin D group,model+CaMKKβ inhibitor group,and model+saikosaponin D+CaMKKβ inhibitor group.The ultrastructure of autophagosomes was observed by transmission electron microscopy.The levels of Ghrelin and SP were detected by ELISA.The expressions of Ca2+and LC-3Ⅱ were detected by immunofluorescence.The protein expression levels of LC-3Ⅱ/Ⅰ、CaMKKβ,p-AMPK,Drp1,MFN2,IP3R and RyR were detected by Western blot.Results The fluorescence expression of LC-3Ⅱ was enhanced.Saikosaponin D reduced the levels of CaMKKβ,AMPK and MFN2(P<0.01),and increased the levels of LC-3Ⅱ/Ⅰ、IP3R,RyR,Drp1,Ghrelin and SP(P<0.01).The effect of Saikosaponin D combined with CaMKKβ inhibitor STO-609 was more significant.Conclusion Saikosaponin D can mediate Ca2+outflow through the CaMKKβ/AMPK signaling pathway,and affect the expression of excessive autophagy and gastrointestinal motility-related factors in ICCs cells.