Aberrant Leukocyte-endothelial Adhesion Participates In Autism And Drug Intervention

Background:Autism is a complex neurological disorders caused by nervous system disorders,which is characterized by social interaction deficits,early-onset difficulties in social communication and repetitive behavior.The disease incidence of autism increases in resent years.Unfortunately,the mechanism of autism is not fully understood yet.The inflammatory response is closely related to the central nervous system diseases and many studies have reported that there are persistent inflammatory lesions in the brain of autism patients.Leukocyte-endothelial cell adhesion is a key step in inflammation,which further leads to the disturbance of neuron vascular unit.Whether this phenomenon happens in pathological process of autism and the specific molecular mechanisms have not been clarified.Objects:Utilizing BTBR mice as an autism model,key inflammatory response in the pathological process of autism was evaluated based on the leukocyte-endothelial adhesion and the pharmacological invention was used to improve the outcome of autism.Methods:1)Leukocyte recruitment and leukocyte-endothelial adhesion in brain vessels of BTBR mice by in vivo two-photon;2)The number of neutrophils and the expression of adhesion molecules in cerebrovascular endothelial cells were detected by flow cytometry;3)Western-blot,immunofluorescence and real-time quantitative PCR were used to detect the inflammation responses in the brain of BTBR mice;4)Alzet osmotic pumps were used to verify the key molecules in disease model.Results:1)Leukocyte-endothelial adhesion was significantly increased in BTBR mice as compared to the wild-type mice;2)The density of neutrophil?the expression level of?2-integrin(CD11b)and brain vascular endothelial cell adhesion molecules ICAM-1 were much higher in BTBR mice by flow cytometry;3)Western blot and immunofluorescence results showed the significantly increased expression level of inflammatory factor such as Caspase-1,IL-1? and cleaved IL-1? in the brain of BTBR mice;4)The mRNA level of chemokine CXCL7 in the endothelial cells of BTBR mice were significantly higher than WT mice by RT-PCR;5)Lysosome Cathepsin B was aberrant increased in the cerebral cortex and blood neutrophils in BTBR mice found by western blot;6)Cathepsin B inhibitor CA-074 Me administration by osmotic pumps not only reduced the leukocyte-endothelial cell adhesion,neutrophils density,but also decreased the expression level of endothelial adhesion molecules and the mRNA level of CXCL7 in the endothelial cells of BTBR mice;7)Cathepsin B inhibitor CA-074 Me can reverse abnormal behavior of BTBR mice in marble-burying test.Conclusion:The significantly increased leukocyte-endothelial adhesion in the cerebral vascular of BTBR mice may result from the abnormal activation of Cathepsin B,which leads to the upregulation of chemokine CXCL7 and CD11b/ICAM-1.Pharmacological inhibition of Cathepsin B could ameliorate the inflammatory response in leukocyte-endothelial adhesion as well as the abnormal behavior in BTBR mice,which suggested that targeting Cathepsin B and the related leukocyte-endothelial adhesion inflammatory responses may shed the light on the treatment of autism.