To elucidate the mechanisms responsible for cytoprotective effects of TNF receptor–activated factor 2 (TRAF2) in the heart, we employed genetic gain- and loss-of-function studies ex vivo and in vivo in mice with cardiac-restricted overexpression of TRAF2 (Myh6-TRAF2LC). Crossing Myh6-TRAF2LC mice with mice lacking canonical signaling (Myh6-TRAF2LC/Myh6-IκBαΔN) abrogated the cytoprotective effects of TRAF2 ex vivo. In contrast, inhibiting the JAK/STAT pathway did not abrogate the cytoprotective effects of TRAF2. Transcriptional profiling of WT, Myh6-TRAF2LC, and Myh6-TRAF2LC/Myh6-IκBαΔN mouse hearts suggested that the noncanonical NF-κB signaling pathway was upregulated in the Myh6-TRAF2LC mouse hearts. Western blotting and ELISA for the NF-κB family proteins p50, p65, p52, and RelB on nuclear and cytoplasmic extracts from naive 12-week-old WT, Myh6-TRAF2LC, and Myh6-TRAF2LC/Myh6-IκBαΔN mouse hearts showed increased expression levels and increased DNA binding of p52 and RelB, whereas there was no increase in expression or DNA binding of the p50 and p65 subunits. Crossing Myh6-TRAF2LC mice with RelB–/+ mice (Myh6-TRAF2LC/RelB–/+) attenuated the cytoprotective effects of TRAF2 ex vivo and in vivo. Viewed together, these results suggest that crosstalk between the canonical and noncanonical NF-κB signaling pathways is required for mediating the cytoprotective effects of TRAF2.
Sarah Evans, Huei-Ping Tzeng, Deborah J. Veis, Scot Matkovich, Carla Weinheimer, Attila Kovacs, Philip M. Barger, Douglas L. Mann
This article was first published February 8, 2018. Usage data is cumulative from February 2018 through August 2018.
Usage information is collected from two different sources: this site (JCI) and Pubmed Central (PMC). JCI information (compiled daily) shows human readership based on methods we employ to screen out robotic usage. PMC information (aggregated monthly) is also similarly screened of robotic usage.
Various methods are used to distinguish robotic usage. For example, Google automatically scans articles to add to its search index and identifies itself as robotic; other services might not clearly identify themselves as robotic, or they are new or unknown as robotic. Because this activity can be misinterpreted as human readership, data may be re-processed periodically to reflect an improved understanding of robotic activity. Because of these factors, readers should consider usage information illustrative but subject to change.