A novel strategy to activate cytoprotective genes in the injured brain

作者：Zhao Jing; Redell John B; Moore Anthony N; Dash Pramod K^*

来源：Biochemical and Biophysical Research Communications, 2011, 407(3): 501-506.

DOI：10.1016/j.bbrc.2011.03.046

• Blood-brain barrier
• Cytoprotective genes
• Keap1
• Nrf2
• Peptide-based therapy
• TBI

The transcription factor nuclear factor E2-related factor 2 (Nrf2) regulates the expression of multiple cytoprotective genes that have been shown to offer protection in response to a number of insults. The present study describes a novel strategy to increase expression of Nrf2-responsive genes in brain injured mice. Under normal conditions, the adapter protein Kelch-like ECH-associated protein 1 (Keap1) binds to Nrf2 and promotes its proteosomal degradation in the cytoplasm. The amino acid sequence DEETGE, located at amino acid 77-82 of Nrf2, is critical for Nr12-Keap1 interaction, and synthetic peptides containing this sequence can be used to disrupt the complex in vitro. We observed that intracerebroventricular (i.c.v.) infusion of a peptide containing the DEETGE sequence along with the cell transduction domain of the HIV-TAT protein (TAT-DEETGE) into brain-injured mice did not increase the mRNA levels for Nrf2-driven genes. However, when a calpain cleavage sequence was introduced between the TAT sequence and the DEETGE sequence, the new peptide (TAT-CAL-DEETGE) increased the mRNA levels of these genes. Increased gene expression was not observed when the TAT-CAL-DEETGE peptide was injected into uninjured animals. Furthermore, injection of TAT-CAL-DEETGE peptides before or after brain injury reduced blood-brain barrier compromise, a prominent secondary pathology that negatively influences outcome. The present strategy to increase Nrf2-responsive gene expression can be adapted to treat other insults or diseases based on their underlying mechanism(s) of cellular damage.

• 出版日期2011-4-15