Study On The Role Of ROS-NLRP3 Signal Pathway In Sterile Inflammation Postoperative Of Thulium Laser Resection Of The Prostate

Background:Thulium laser resection of the prostate(TmLRP)is one of the major minimally invasive surgical methods for the treatment of benign prostatic hyperplasia(BPH),with less bleeding,less trauma and less complication.But the sterile inflammation(SI)of the urinary tract is a common problem after surgery,the incidence of which is as high as 17%in 1 month postoperative.Lack of effective treatments,it does a serious impact on postoperative recovery and efficacy,but the relevant researches are rarely reported.At present,the development mechanism of urinary tract SI after TmLRP is unclear.In the previous study,we examined the prostate tissue specimens after surgery and found that the innate immune response initiated by damage associated molecular patterns(DAMPs)may be one of the causes of SI induction.The latest study found that reactive oxygen species(ROS)were highly expressed in semen of patients with chronic prostatitis,activating NLRP3 inflammasome to induce a series of inflammatory responses,suggesting that ROS-NLRP3 signaling pathways may play an important role in the urinary system inflammation,which inspired us to follow the direction to find the treatment target of postoperative SI of TmLRP.Objectives:1.To study the development stage of urinary tract SI after TmLRP.2.To clarify the mechanism of DAMPs to initiate the innate immune response,promote the expression of inflammatory factors and its relationship with ROS-NLRP3 signaling pathway.3.To clarify the expression and mechanism of ROS-NLRP3 signaling pathway in postoperative urinary tract SI after TmLRP and find potential method to reduce the SI.Methods:1.ELISA method was used to detect the levels of inflammatory cells(granulocytes,monocytes,macrophages,etc.)and inflammatory factors(HSP70,IL-1β,IL-18)in serum and urine of 25 patients with TmLRP before and after operation.The expression of HSP70 was detected by immunohistochemistry with the negative biopsy specimens of BPH as control.2.The expression of ROS,NLRP3,Caspase-1,IL-1β and IL-18 were detected by FCM,ELISA,Western Blot and qRT-PCR after stimulation with THP-1 and HSP70 in vitro.NAC pretreatment of THP-1,observed the expression of the above factors.3.Establish experimental canine animal model of TmLRP.the control group of 10 dogs were treated with TmLRP.The levels of serum and urine inflammatory factors(HSP70,IL-1β,IL-18)were detected by ELISA at different time before and after operation.The expressions of NLRP3 and Caspase-1 were detected by immunofluorescence and immunohistochemistry.The developmental stages and intensity were detected.Another group of 10 dogs with ROS inhibitor NAC pretreatment were used in surgical channels preoperative to observe its impact on SI.Results:1.Clinical specimens test showed that expression of inflammatory factors increased rapidly within 7 days postoperative of TmLRP in urine and the peak time was 3-5 days after surgery;the trend of HSP70,TNFα,IL-1β in urine was similar to that of peripheral blood neutrophils,while IL-18 was similar to that of peripheral blood mononuclear cells and eosinophils.The expression of HSP70 was observed in the prostate tissue immediately.2.After stimulated monocyte-macrophage THP-1 in vitro,the expression of ROS,NLRP3,Caspase-1 and IL-18 increased and the peak time was 12h and IL-1β reached to peak at 6h.THP-1 was stimulated by HSP70 after ROS inhibitor NAC and the expression of factors above were lower than that of the study group.3.Animal model experiments suggest that dog TmLRP postoperative SI was divided as acute inflammation and chronic inflammation.Acute stage started from surgery to 7 days after surgery,of which 3 days after surgery was acute inflammation peak.Chronic inflammation was 7 days to 28 days after surgery,of which 14 days was chronic inflammation peak.HSP70,NLRP3,Caspase-1,IL-1β and 1L-18 were highly expressed at different time points after operation.NAC pretreatment surgery can reduce the release of postoperative ROS,inhibit the expression of NLRP3 signaling pathway,and reduce the postoperative blood,urine and prostate tissue SI.Conclusions:1.TmLRP postoperative SI was divided as acute inflammation and chronic inflammation.Acute stage started from surgery to 7 days after surgery,of which 3 days after surgery was acute inflammation peak.Chronic inflammation was 7 days to 28 days after surgery,of which 14 days was chronic inflammation peak.Expression of inflammatory cells and inflammatory factors changed in different time periods.2.HSP70 expressed immediately after TmLRP,activated of ROS-NLRP3 signaling pathway and Caspase-1,promoted inflammatory factors IL-1β,IL-18 expression,induced SI3.ROS inhibitor NAC pretreatment before surgery,can inhibit the ROS-NLRP3 signaling pathway,reduce SI.The ROS-NLRP3 signaling pathway can serve as a target for the control of SI.