Ebv-mediated BDNF Expression in B Cells is Causally Linked to the Persistence of Hic-induced Pathogenesis
Jia-Fong Jhang, Hann-Chorng Kuo
Department of Urology, Haulien Tzu Chi Hospital.
Purpose: The bladders of interstitial cystitis/bladder pain syndrome (IC/BPS) were characterized by persisting inflammation and nerve hyperplasia, and the IC/BPS patients with Hunner’s lesion (HIC) have more severe bladder inflammation. However, the pathogenesis is still uncertain. Our previous study showed EBV infection in the IC/BPS bladders. Current study aimed to investigate the EBV infection type and associated bladder cytokines expression changes in the IC/BPS patients with Hunner’s lesion (HIC).
Materials and Methods: The bladder specimen from HIC and control subjects were analyzed with flowcytometry, immunochemical staining and western blot. Whole transcriptomic RNA sequencing was also performed for the bladder specimens. EBV infected B lymphocyte was injected into rat bladders.
Results: The flow cytometry and immunochemical staining results showed both EBV latency and lytic infection majorly in the B cells were presented the HIC bladders. Nerve hyperplasia and up-regulation of BDNF were also noted in the HIC bladders, and the flowcytometry and double immunochemical staining revealed the origin should be the EBV infected B cells. In vitro cells study exhibited significant BDNF expression in the EBV infected B cells but not in the T cells. Transfection of EBV viral proteins to cells also induced BDNF expression. Chromatin immunoprecipitation showed the EBV nuclear proteins, especially the EBNA-1, could work with human epigenetic modification enhancers to act on BDNF promoter to initiate BDNF synthesis. Knockdown BDNF in EBV infected B cells resulted in inhibition of cell proliferation and viability, and suppressing phosphorylation of SMAD2 and STAT3 may play a role in the mechanism. In vivo preclinical rats study revealed injection EBV infected B cells into bladder wall could result in more significant bladder inflammation and nerve hyperplasia in the bladders. The EBV bladder injected rats also had more reduction of micturition volume and increasing micturition number.
Conclusions: Our results revealed EBV infection should play an important role in the mechanism of persistent inflammation and nerve hyperplasia in the HIC bladders.