Abstract
Purpose :
Tnfaip3/A20 is required for terminating NFkappaB signaling in response to microbial products such as lipopolysaccharide (LPS). Loss of Tnfaip3/A20 functions has been associated with many autoimmune diseases in human. We have reported that Tnfaip3/A20 has an alternative transcriptional start-site specifically in mouse retina, however the functions of Tnfaip3/A20 in retina remain unclear. In this study we explored characterizations of Tnfaip3/A20 in response to LPS in retina compared to the response in spleen of same animals.
Methods :
Animal use was in accordance with ARVO and IACUC guidelines at Penn State University College of Medicine. C57BL/6j mice (Jackson Lab) in experimental groups were treated intraperitoneally with LPS from Escherichia coli 055:B5 (Sigma-Aldrich). Saline was used as control. Retina and spleen tissues were collected from each animal. RNA extraction/purification (Qiagen).and RNA reverse transcription (Invitrogen) followed the manufacturer’s protocol. Two sets of primers were designed specifically to distinguish the RNA products from two transcriptional start-sites. Beta-actin was served as internal RNA control. PCR reaction was employed to examine the products. For quantitative analysis, the intensity of RT-PCR band was analyzed via ImageJ (version 1.46r) and further statistical analysis was done by unpaired Student t-test or one-way ANOVA based on the experimental designs. The expression of Tnfaip3/A20 during mouse retina development was analyzed from a previous dataset generated from this lab.
Results :
The developmental expression pattern of Tnfaip3/A20 matched perfectly that of a set of well-known retina-specific genes including Rs1h, Abca4 and Rho, but differed from the expressions of Tnfaip1 or Tnfaip2, other members of the same gene family as Tnfaip3/A20. In response to LPS treatment, the level of Tnfaip3/A20 from spleen extracts presented a de novo expression and reached the peak at 1 hour after LPS treatment, which agreed with many previous studies. However the expression of Tnfaip3/A20 from retina tissues showed a higher level at the beginning, decreasing at 1 hour and reached the lowest level at 24 hours.
Conclusions :
A distinct responding pattern to LPS treatment between retinas and spleens was uncovered in this study. Giving the important role of Tnfaip3/A20 in NFkappaB pathway, further investigation of Tnfaip3/A20 functions in retina is needed.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.