Expression And Function Of HMGB1 And Its Receptor,NF-κB At The Maternal Fetal Interface In Patients With Unexplained Recurrent Abortion

Objective: High Mobility Group Protein B1(HMGB1)has been reported to play a key role in the physiological and pathophysiological responses during pregnancy.Unexplained recurrent spontaneous abortion(URSA),as one of the pathological pregnancies,is characterized by inflammation and thrombus formation at the maternal fetal interface.Although it has been reported that the serum concentration of HMGB1 in patients with URSA is higher than that in the normal early pregnant population,it is still unknown that the local response capacity of HMGB1 at the maternal fetal interface.Does HMGB1,as a typical late inflammatory factor,participate in the occurrence and development of URSA? The purpose of this study was to investigate the expression distribution and characteristics of HMGB1,its receptor(RAGE / TLR2 / 4)and its important signal molecule nuclear,and factor-κ bp65(NF-κ bp65)at the maternal fetal interface,and the difference of serum concentration of HMGB1 between URSA group and normal control group.Furthermore,to explore the difference of HMGB1 expression between the group with and without aspirin pretreatment group in URSA group,and to know the influence of aspirin on serum HMGB1 concentration in order to confirm the role of HMGB1 in URSA.Material and Methods: In our study,decidua,villus and blood samples were collected from artificial abortion volunteers of normal early pregnancies(control group)and URSA patients respectively.H&E staining was supplied to detect the infiltration of inflammatory cells at the maternal-fetal interface.The double-immunofluorescence staining was used to define the cell type of HMGB1 expression.Immunohistochemical staining was applied to determine the transposition of HMGB1 and NF-κB.Western blot analysis was applied to determine the expression of HMGB1 and its receptors at the maternal-fetal interface.ELISA was utilized to detect the concentration of HMGB1 in plasma.Result:(1)The increased number of immune cells infiltration was detected at the maternal-fetal interface of URSA patients.(2)Immunohistochemical results showed that HMGB1 was mainly expressed in the nucleus of the control group.While in the URSA group,HMGB1 could be expressed in nucleus,cytoplasm and extracellular matrix.(3)Immunofluorescence staining demonstrated that the excessive expression of HMGB1 was mainly originated from immune cells.(4)Western Blot analysis showed that the expression level of HMGB1,TLR2/4,NF-Κ B protein in URSA group increased compared with the control group.(5)The HMGB1 concentration was higher in URSA group than that in the control group.Furthermore,the levels of HMGB1 of subjects with URSA reduced by administrating low doses of aspirin(ASPL).Conclusions:(1)Our study demonstrated that HMGB1 was related with the development of URSA.The possible mechanism may result from HMGB1-RAGE/TLR2/TLR4-NF-κB signaling pathway activated at the maternal-fetal interface of URSA(2)This is the first report indicating the roles of HMGB1 at the maternal-fetal interface of URSA patients and broadening the horizons for clinical diagnosis and treatment of URSA.