title: MicroRNA-19a and CD22 Comprise a Feedback Loop for B Cell Response in Sepsis.
abstract: BACKGROUND
  MicroRNA-19a (miR-19a), an oncogenic microRNA, has been recently reported to target CD22 in B cell lymphoma cell lines, but its role in inflammatory response is unclear. CD22 is a negative regulator for BCR signaling, and we hypothesize that miR-19a regulates B cell response by targeting CD22 in sepsis.
  
  
  METHODS
  In order to determine whether miR-19a-CD22 pathway was involved in sepsis, and what role it played in the regulatory mechanisms, we detected the levels of miR-19a in B cells obtained from patients with sepsis, and measured the levels of miR-19a and CD22 expression in B cells activated by LPS in vitro. Additionally, we investigated the correlation between miR-19a and CD22, as well as the influence of this pathway on BCR signaling, in transfected B cells.
  
  
  RESULTS
  We found that septic patients displayed up-regulated miR-19a in B cells. In vitro, miR-19a was increased in activated B cells, with CD22 expression initially enhanced but subsequently decreased. Moreover, overexpression of miR-19a resulted in an amplified BCR signaling, while overexpression of CD22 attenuated the effect of miR-19a and increased its expression.
  
  
  CONCLUSIONS
  Our study demonstrated that miR-19a and CD22 comprised a feedback loop for B cell response in sepsis, providing a potential therapeutic target to recover the immune homeostasis.
authors.affiliation: Institute of Organ Transplantation, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Key Laboratory of Ministry of Health, and Key Laboratory of Ministry of Education, Wuhan, Hubei, China (mainland).
authors.forename: Yinan
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: Department of Cardiothoracic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China (mainland).
authors.forename: Hongmin
authors.initials: H
authors.lastname: Zhou
authors.affiliation: Department of General Surgery, Wuhan General Hospital of Guangzhou Military Command, Wuhan, Hubei, China (mainland).
authors.forename: Dandan
authors.initials: D
authors.lastname: Ma
authors.affiliation: Institute of Organ Transplantation, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Key Laboratory of Ministry of Health, and Key Laboratory of Ministry of Education, Wuhan, Hubei, China (mainland).
authors.forename: Zhonghua Klaus
authors.initials: ZK
authors.lastname: Chen
authors.affiliation: Department of General Surgery, Wuhan General Hospital of Guangzhou Military Command, Wuhan, Hubei, China (mainland).
authors.forename: Xun
authors.initials: X
authors.lastname: Cai
mesh_terms: D000704:Analysis of Variance; D001402:B-Lymphocytes / Q000276:immunology*; D015153:Blotting, Western; D002681:China; D017931:DNA Primers / Q000235:genetics; D025461:Feedback, Physiological; D005434:Flow Cytometry; D006801:Humans; D066298:In Vitro Techniques; D008070:Lipopolysaccharides; D035683:MicroRNAs / Q000276:immunology*; D060888:Real-Time Polymerase Chain Reaction; D018805:Sepsis / Q000276:immunology*; D051918:Sialic Acid Binding Ig-like Lectin 2 / Q000276:immunology*
chemical_list: C497867:CD22 protein, human; D017931:DNA Primers; D008070:Lipopolysaccharides; C549214:MIRN19A microRNA, human; D035683:MicroRNAs; D051918:Sialic Acid Binding Ig-like Lectin 2