Genetic modifications of EGLN1 reactivate HbF production in β0-thalassemia/HbE
Varit Jan-ngam,
Siriraj Boontha,
Alisa Tubsuwan,
Somsakul Pop Wongpalee,
Kanda Fanhchaksai,
Adisak Tantiworawit,
Pimlak Charoenkwan,
Pinyaphat Khamphikham
Affiliations
Varit Jan-ngam
Master of Science Program in Medical Technology, Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand; Division of Clinical Microscopy, Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
Siriraj Boontha
Bachelor of Science Program in Medical Technology, Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand
Alisa Tubsuwan
Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom, Thailand
Somsakul Pop Wongpalee
Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
Kanda Fanhchaksai
Division of Hematology and Oncology, Department of Pediatrics, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand; Thalassemia and Hematology Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
Adisak Tantiworawit
Division of Hematology, Department of Internal Medicine, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
Pimlak Charoenkwan
Division of Hematology and Oncology, Department of Pediatrics, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand; Thalassemia and Hematology Center, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
Pinyaphat Khamphikham
Division of Clinical Microscopy, Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand; Hematology and Health Technology Research Center, Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand; Corresponding author. Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University, Chiang Mai, Thailand.
Reactivation of fetal hemoglobin (HbF, α2γ2) potentially alleviates clinical presentation in β-thalassemia. Prolyl hydroxylase domain enzymes (PHDs) play roles in the canonical oxygen-sensing pathway and maintain the stability of cellular hypoxia-inducible factor α (HIF-α) in response to low oxygen levels or hypoxia. Pharmacological inhibition of PHDs has been shown to increase HbF production in erythroid progenitors derived from healthy donors. Here, we demonstrated the relationship between PHD2, the main PHD isoform, and clinical phenotypes in β0-thalassemia/HbE disease. Although the targeted sequencing annotated several common variants within EGLN1, the gene encoding PHD2, none of these variants were located in the functional domains of PHD2 and were irrelevant to the clinical phenotypes. CRISPR-mediated EGLN1 modifications at the functional regions; however, led to significantly reduce PHD2 expression and increase HbF expression levels in severe β-thalassemia erythroblasts. Moreover, these beneficial phenotypes were independent to the two well-known HbF regulators including BCL11A and GATA1. Our findings introduce an additional mechanism for HbF regulation in β-thalassemia and propose that targeting the canonical oxygen-sensing pathway, particularly PHD2 functional domains, might offer a promising therapeutic strategy to β-thalassemia diseases.
