Selective AMPKβ1 activation induces fetal hemoglobin in human erythroid cells and sickle cell mice via the noncanonical NRF2 pathway.

Sickle cell disease (SCD), an inherited blood disorder caused by mutation of the β-globin gene, results in sickle-shaped erythrocytes, organ damage, and increased mortality. Current therapeutic options are limited, and innovative treatments to induce fetal hemoglobin (HbF) are needed. Adenosine monophosphate-activated protein kinase (AMPK) comprises a family of 12 isoforms. In the present study, single-cell RNA sequencing of bone marrow cells revealed that AMPKβ1 isoform (AMPKα1β1γ1) predominates in the erythroid lineage. AMPKβ1 activators increased the expression of HbF in erythroid cells from SCD donors and decreased sickling in vitro through activation of nuclear factor erythroid 2-related factor 2 (NRF2) but independently from direct Kelch-like ECH-associated protein 1 (KEAP1) inhibition, by way of a noncanonical NRF2 pathway, as shown by phosphorylation of Unc-51-like autophagy-activating kinase 1 (ULK1) and sequestosome 1/p62 (SQSTM1). In vivo studies in Townes SCD mice treated with the selective AMPKβ1 activator PF-06409577 confirmed increased HbF in circulating erythrocytes, associated with decreased reactive oxygen species and reduced chronic inflammation markers. Collectively, these findings establish selective AMPKβ1 activation as a promising therapeutic approach to induce HbF in hemoglobinopathies.