Trafficking of the transcription factor Nrf2 to promyelocytic leukemia-nuclear bodies: implications for degradation of NRF2 in the nucleus.

Ubiquitylation of Nrf2 by the Keap1-Cullin3/RING box1 (Cul3-Rbx1) E3 ubiquitin ligase complex targets Nrf2 for proteasomal degradation in the cytoplasm and is an extensively studied mechanism for regulating the cellular level of Nrf2. Although mechanistic details are lacking, reports abound that Nrf2 can also be degraded in the nucleus. Here, we demonstrate that Nrf2 is a target for sumoylation by both SUMO-1 and SUMO-2. HepG2 cells treated with As2O3, which enhances attachment of SUMO-2/3 to target proteins, increased SUMO-2/3-modification (polysumoylation) of Nrf2. We show that Nrf2 traffics, in part, to promyelocytic leukemia-nuclear bodies (PML-NBs). Cell fractions harboring key components of PML-NBs did not contain biologically active Keap1 but contained modified Nrf2 as well as RING finger protein 4 (RNF4), a poly-SUMO-specific E3 ubiquitin ligase. Overexpression of wild-type RNF4, but not the catalytically inactive mutant, decreased the steady-state levels of Nrf2, measured in the PML-NB-enriched cell fraction. The proteasome inhibitor MG-132 interfered with this decrease, resulting in elevated levels of polysumoylated Nrf2 that was also ubiquitylated. Wild-type RNF4 accelerated the half-life (t½) of Nrf2, measured in PML-NB-enriched cell fractions. These results suggest that RNF4 mediates polyubiquitylation of polysumoylated Nrf2, leading to its subsequent degradation in PML-NBs. Overall, this work identifies Nrf2 as a target for sumoylation and provides a novel mechanism for its degradation in the nucleus, independent of Keap1.

Developing an emergency department order set to treat acute pain in sickle cell disease.

STUDY OBJECTIVE: Patients with sickle cell disease (SCD) have many emergency department visits because of painful vaso-occlusive episodes (VOE). Guidelines recommend treatment within 30 minutes of triage, but this is rarely achieved in clinical practice. Our goal was to develop an order set that is being implemented in the ED to facilitate and standardize emergency care for SCD patients in acute pain from VOEs presenting to the emergency department (ED) in New York City (NYC). METHODS: Using a RAND/University of California, Los Angeles modified Delphi panel, we convened a multidisciplinary panel and reviewed evidence on how to best manage SCD pain in the ED. Panelists collaboratively developed then rated 202 items that could be included in an ED order set. RESULTS: A consensus order set, a practical how-to guide for managing SCD pain in the ED, was developed based on items that received high median ratings. CONCLUSIONS: The management of acute pain experienced during VOEs is critical to patients with SCD; ED order sets, such as this one, can help standardize pain management, including at triage, evaluation, discharge, and follow-up care. After implementation in NYC EDs, studies to examine changes in quality care metrics (eg, wait times, readmissions) are planned.