Loss of miR-144/451 alleviates β-thalassemia by stimulating ULK1-mediated autophagy of free α-globin.

Autor:	Keith J; Department of Hematology, St. Jude Children's Research Hospital, Memphis, TN., Christakopoulos GE; Department of Hematology, St. Jude Children's Research Hospital, Memphis, TN., Fernandez AG; Department of Hematology, St. Jude Children's Research Hospital, Memphis, TN., Yao Y; Department of Hematology, St. Jude Children's Research Hospital, Memphis, TN., Zhang J; Department of Hematology, St. Jude Children's Research Hospital, Memphis, TN., Mayberry K; Department of Hematology, St. Jude Children's Research Hospital, Memphis, TN., Telange R; Department of Hematology, St. Jude Children's Research Hospital, Memphis, TN., Sweileh RBA; Department of Hematology, St. Jude Children's Research Hospital, Memphis, TN., Dudley M; Department of Hematology, St. Jude Children's Research Hospital, Memphis, TN., Westbrook C; Department of Hematology, St. Jude Children's Research Hospital, Memphis, TN., Sheppard H; Department of Pathology, St. Jude Children's Research Hospital, Memphis, TN.; Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN., Weiss MJ; Department of Hematology, St. Jude Children's Research Hospital, Memphis, TN., Lechauve C; Department of Hematology, St. Jude Children's Research Hospital, Memphis, TN.
Jazyk:	angličtina
Zdroj:	Blood [Blood] 2023 Sep 07; Vol. 142 (10), pp. 918-932.
DOI:	10.1182/blood.2022017265
Abstrakt:	Most cells can eliminate unstable or misfolded proteins through quality control mechanisms. In the inherited red blood cell disorder β-thalassemia, mutations in the β-globin gene (HBB) lead to a reduction in the corresponding protein and the accumulation of cytotoxic free α-globin, which causes maturation arrest and apoptosis of erythroid precursors and reductions in the lifespan of circulating red blood cells. We showed previously that excess α-globin is eliminated by Unc-51-like autophagy activating kinase 1 (ULK1)-dependent autophagy and that stimulating this pathway by systemic mammalian target of rapamycin complex 1 (mTORC1) inhibition alleviates β-thalassemia pathologies. We show here that disrupting the bicistronic microRNA gene miR-144/451 alleviates β-thalassemia by reducing mTORC1 activity and stimulating ULK1-mediated autophagy of free α-globin through 2 mechanisms. Loss of miR-451 upregulated its target messenger RNA, Cab39, which encodes a cofactor for LKB1, a serine-threonine kinase that phosphorylates and activates the central metabolic sensor adenosine monophosphate-activated protein kinase (AMPK). The resultant enhancement of LKB1 activity stimulated AMPK and its downstream effects, including repression of mTORC1 and direct activation of ULK1. In addition, loss of miR-144/451 inhibited the expression of erythroblast transferrin receptor 1, causing intracellular iron restriction, which has been shown to inhibit mTORC1, reduce free α-globin precipitates, and improve hematological indices in β-thalassemia. The beneficial effects of miR-144/451 loss in β-thalassemia were inhibited by the disruption of Cab39 or Ulk1 genes. Together, our findings link the severity of β-thalassemia to a highly expressed erythroid microRNA locus and a fundamental, metabolically regulated protein quality control pathway that is amenable to therapeutic manipulation. (© 2023 by The American Society of Hematology.)
Databáze:	MEDLINE
Externí odkaz:	Zobrazit plný text záznamu