Expression profiles of Nrf1 and Nrf2 in adult rat small intestine

Safeguarding the integrity and functionality of the gastrointestinal system is paramount, given its vulnerability to several detrimental effects. One of the factors that can cause functional disorders is oxidative stress, which can disrupt the homeostasis of intestinal tissue and cause various diseases. In this study, we aimed to evaluate the expression patterns of nuclear factor erythroid 2-like 1 (Nrf1) and nuclear factor erythroid 2-like 2 (Nrf2) transcription factors, which are part of an important cleaning system that protects cells against oxidative stress, in the adult rat small intestine by immunohistochemical means. Six Wistar albino adult rats were used in this study. After taking 5 μm thick sections of the small intestine, immunohistochemistry labeling was performed to investigate the expression of Nrf1 and Nrf2. Both transcription factors were found to exhibit immunopositivity in the duodenum, jejunum, and ileum segments of the small intestine. In the crypt epithelium, Nrf1 and Nrf2 showed similar intensity and distribution of staining, whereas, in the villus epithelium, Nrf2 immunoreactivity was most prominent in the ileum and weakest in the jejunum. Nrf1 exhibited lower staining intensity in the ileum. In the smooth muscle layers and the myenteric plexus, Nrf2 immunopositivity was highest in the duodenum, while it was weaker in the jejunum and ileum. These findings indicate that Nrf1 and Nrf2 display region-specific expression patterns in the small intestine and suggest that these transcription factors may play distinct roles in the regional oxidative stress response of intestinal tissues.