Effect Of Mst1 On Endometriosis Apoptosis And Migration:Role Of Mitochondrial Fission And Mitophagy

BackgroundMitochondrial homeostasis is implicated in the development and progression of endometriosis through poorly defined mechanisms.Mst1 is the major growth suppressor related to cancer migration,apoptosis and proliferation.However,whether Mst1 is involved in endometriosis apoptosis and migration via regulating the mitochondrial function remains to be elucidated.ObjectTo explore the role of Mst1 in the development and progression of endometriosis,especially in Drp1-related mitochondrial fission and Parkin-required mitophagy.To verify the p53 pathway and identify the upstream regulating signals of Mst1.To determine the potential target in endometriosis therapy.Methods1.Expression of Mst1 in endometriosis was examined via western blots.2.Cellular apoptosis was detected via MTT and TUNEL assay.3.Gain of function assay about target gene was conducted via adenovirus over-expression;loss of function assay about target gene was conducted via siRNA knockdown.4.Mitochondrial functions evaluation.a.Mitochondrial membrane potential change(??m)was evaluated via JC-1 staining,for the drop of ??m indicates early stage of apoptosis.b.ROS flow cytometry analysis,mPTP opening assessment,because of the mPTP opening,the mitochondria-contained pro-apoptotic factors are released into the cytoplasm,evoking apoptosis.c.Immunofluorescence of HtrA2/Omi,which is a pro-apoptotic factor.d.The mitophagy activity were examined via western blots and immunofluorescence.ResultsFirst,we found that Mst1 was significantly downregulated in the ectopic endometrium of endometriosis compared to the normal endometrium.However,the recovery of Mst1 function was closely associated with the inability of endometrial stromal cells(ESCs)to migrate and survive.A functional study indicated that regaining Mst1 enhanced Drpl post-transcriptional phosphorylation at Ser616 and repressed Parkin transcription activity via p53,leading to mitochondrial fission activation and mitophagy inhibition.Excessive Drpl-related fission forced the mitochondria to liberate HtrA2/Omi into the cytoplasm.Moreover,Mst1-induced defective mitophagy evoked cellular oxidative stress,energy metabolism and calcium overload.Through excessive mitochondrial fission and aberrant mitophagy,Mst1 launched caspase 9-related mitochondrial apoptosis and abrogated F-actin/lamellipodium-dependent cellular migration.Notably,we also defined NR4A/miR181c as the upstream signal for Mst1 dysfunction in endometriosis.ConclusionCollectively,our results comprehensively described the important role of the NR4A-miR181c-Mst1 pathway in endometriosis,which handled mitochondrial apoptosis and F-actin/lamellipodium-based migration via the regulation of Drpl-related mitochondrial fission and Parkin-required mitophagy,with a potential application in endometriosis therapy by limiting ESCs migration and promoting apoptosis.