TY  - JOUR
AU  - Ugrin, Milena
AU  - Stojiljković, Maja
AU  - Zukić, Branka
AU  - Klaassen, Kristel
AU  - Katsila, Theodora
AU  - Komazec, Jovana
AU  - Dokmanović, Lidija
AU  - Janić, Dragana
AU  - Patrinos, George P.
AU  - Pavlović, Sonja
PY  - 2016
UR  - https://imagine.imgge.bg.ac.rs/handle/123456789/975
AB  - Hereditary persistence of fetal hemoglobin (HPFH) is a condition characterized by persistent -globin gene expression and synthesis of high levels of fetal hemoglobin (Hb F; 22) during adult life. It is usually caused by promoter variants or large deletions affecting the human fetal globin (HBG1 and HBG2) genes. Some of these HPFH-causing variants, such as HBG2: g.-158C gt T, exert their effect only under conditions of erythropoietic stress, typical for -thalassemia (-thal) patients. Namely, the presence of HBG2: g.-158C gt T favors a higher Hb F response, while it has little effect in healthy individuals. We analyzed a previously reported deletion residing in the promoter region of the HBG1 gene (HBG1: g.-225_-222delAGCA), both in normal conditions and under conditions of erythropoietic stress. Our results indicate that this deletion is responsible for decreased HBG1 gene expression. Specifically, this deletion was shown to result in drastically reduced reporter gene expression in K562 cells, compared to the wild-type sequence but only under conditions of erythropoietic stress, mimicked by introduction of erythropoietin (EPO) into the cell culture. Also, electrophoretic mobility shift analysis showed that the HBG1: g.-225_-222delAGCA deletion creates additional transcriptional factors' binding sites, which, we propose, bind a transcriptional repressor, thus decreasing the HBG1 gene promoter activity. These results are consistent with in silico analysis, which indicated that this deletion creates a binding site for GATA1, known to be a repressor of the -globin gene expression. These data confirm the regulatory role of the HBG1: g.-225_-222 region that exerts its effect under conditions of erythropoietic stress characteristic for -thal patients.
PB  - Taylor & Francis Ltd, Abingdon
T2  - Hemoglobin
T1  - Functional Analysis of an (A)gamma-Globin Gene Promoter Variant (HBG1: g.-225_-222delAGCA) Underlines Its Role in Increasing Fetal Hemoglobin Levels Under Erythropoietic Stress
EP  - 52
IS  - 1
SP  - 48
VL  - 40
DO  - 10.3109/03630269.2015.1107842
ER  - 

@article{
author = "Ugrin, Milena and Stojiljković, Maja and Zukić, Branka and Klaassen, Kristel and Katsila, Theodora and Komazec, Jovana and Dokmanović, Lidija and Janić, Dragana and Patrinos, George P. and Pavlović, Sonja",
year = "2016",
abstract = "Hereditary persistence of fetal hemoglobin (HPFH) is a condition characterized by persistent -globin gene expression and synthesis of high levels of fetal hemoglobin (Hb F; 22) during adult life. It is usually caused by promoter variants or large deletions affecting the human fetal globin (HBG1 and HBG2) genes. Some of these HPFH-causing variants, such as HBG2: g.-158C gt T, exert their effect only under conditions of erythropoietic stress, typical for -thalassemia (-thal) patients. Namely, the presence of HBG2: g.-158C gt T favors a higher Hb F response, while it has little effect in healthy individuals. We analyzed a previously reported deletion residing in the promoter region of the HBG1 gene (HBG1: g.-225_-222delAGCA), both in normal conditions and under conditions of erythropoietic stress. Our results indicate that this deletion is responsible for decreased HBG1 gene expression. Specifically, this deletion was shown to result in drastically reduced reporter gene expression in K562 cells, compared to the wild-type sequence but only under conditions of erythropoietic stress, mimicked by introduction of erythropoietin (EPO) into the cell culture. Also, electrophoretic mobility shift analysis showed that the HBG1: g.-225_-222delAGCA deletion creates additional transcriptional factors' binding sites, which, we propose, bind a transcriptional repressor, thus decreasing the HBG1 gene promoter activity. These results are consistent with in silico analysis, which indicated that this deletion creates a binding site for GATA1, known to be a repressor of the -globin gene expression. These data confirm the regulatory role of the HBG1: g.-225_-222 region that exerts its effect under conditions of erythropoietic stress characteristic for -thal patients.",
publisher = "Taylor & Francis Ltd, Abingdon",
journal = "Hemoglobin",
title = "Functional Analysis of an (A)gamma-Globin Gene Promoter Variant (HBG1: g.-225_-222delAGCA) Underlines Its Role in Increasing Fetal Hemoglobin Levels Under Erythropoietic Stress",
pages = "52-48",
number = "1",
volume = "40",
doi = "10.3109/03630269.2015.1107842"
}

Ugrin, M., Stojiljković, M., Zukić, B., Klaassen, K., Katsila, T., Komazec, J., Dokmanović, L., Janić, D., Patrinos, G. P.,& Pavlović, S.. (2016). Functional Analysis of an (A)gamma-Globin Gene Promoter Variant (HBG1: g.-225_-222delAGCA) Underlines Its Role in Increasing Fetal Hemoglobin Levels Under Erythropoietic Stress. in Hemoglobin
Taylor & Francis Ltd, Abingdon., 40(1), 48-52.
https://doi.org/10.3109/03630269.2015.1107842

Ugrin M, Stojiljković M, Zukić B, Klaassen K, Katsila T, Komazec J, Dokmanović L, Janić D, Patrinos GP, Pavlović S. Functional Analysis of an (A)gamma-Globin Gene Promoter Variant (HBG1: g.-225_-222delAGCA) Underlines Its Role in Increasing Fetal Hemoglobin Levels Under Erythropoietic Stress. in Hemoglobin. 2016;40(1):48-52.
doi:10.3109/03630269.2015.1107842 .

Ugrin, Milena, Stojiljković, Maja, Zukić, Branka, Klaassen, Kristel, Katsila, Theodora, Komazec, Jovana, Dokmanović, Lidija, Janić, Dragana, Patrinos, George P., Pavlović, Sonja, "Functional Analysis of an (A)gamma-Globin Gene Promoter Variant (HBG1: g.-225_-222delAGCA) Underlines Its Role in Increasing Fetal Hemoglobin Levels Under Erythropoietic Stress" in Hemoglobin, 40, no. 1 (2016):48-52,
https://doi.org/10.3109/03630269.2015.1107842 . .