Enhancement of Regnase-1 expression with stem loop–targeting antisense oligonucleotides alleviates inflammatory diseases
K.M. Tse, Alexis Vandenbon, Xiaotong Cui, Takashi Mino, Takuya Uehata, Keiko Yasuda, Ayuko Sato, Tohru Tsujimura, Fabian Hia, Masanori Yoshinaga, Makoto Kinoshita, Tatsusada Okuno, Osamu Takeuchi
Abstract
Regnase-1 is an ribonuclease that plays essential roles in restricting inflammation through degrading messenger RNAs (mRNAs) involved in immune reactions via the recognition of stem-loop (SL) structures in the 3′ untranslated regions (3′UTRs). Dysregulated expression of Regnase-1 is associated with the pathogenesis of inflammatory and autoimmune diseases in mice and humans. Here, we developed a therapeutic strategy to suppress inflammatory responses by blocking Regnase-1 self-regulation, which was mediated by the simultaneous use of two antisense phosphorodiamidate morpholino oligonucleotides (MOs) to alter the binding of Regnase-1 toward the SL structures in its 3′UTR. Regnase-1–targeting MOs not only enhanced Regnase-1 expression by stabilizing mRNAs but also effectively reduced the expression of multiple proinflammatory transcripts that were controlled by Regnase-1 in macrophages. Intratracheal administration of Regnase-1–targeting MOs ameliorated acute respiratory distress syndrome and chronic fibrosis through suppression of inflammatory cascades. In addition, intracranial treatment with Regnase-1–targeting MOs attenuated the development of experimental autoimmune encephalomyelitis by promoting the expansion of homeostatic microglia and regulatory T cell populations. Regnase-1 expression was inversely correlated with disease severity in patients with multiple sclerosis, and MOs targeting human Regnase-1 SL structures were effective in mitigating cytokine production in human immune cells. Collectively, MO-mediated disruption of the Regnase-1 self-regulation pathway is a potential therapeutic strategy to enhance Regnase-1 abundance, which, in turn, provides therapeutic benefits for treating inflammatory diseases by suppressing inflammation.