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Donald Lavelle - One of the best experts on this subject based on the ideXlab platform.
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LSD1 inhibitor RN-1 stimulates HbF Synthesis 1
2016Co-Authors: Raymond C. Trievel, Angela Rivers, Joseph Desimone, Donald Lavelle, Yogen Saunthararajah, James Douglas EngelAbstract:Key Points 1. RN-1 treatment of SCD mice results in increased human fetal γ-globin induction and fetal Hemoglobin Synthesis. 2. RN-1 treatment of SCD mice significantly reduces sickling, hemolysis and tissue injury with no obvious adverse side effects. Inhibition of lysine-specific demethylase 1 (LSD1) has been shown to induce fetal Hemoglobin (HbF) levels in cultured human erythroid cells in vitro. Here we report the in vivo effects of LSD1 inactivation by a selective and more potent inhibitor, RN-1, in a sickle cell disease (SCD) mouse model. Compared to untreated animals, RN-1 administration leads to induced HbF Synthesis and to increased frequencies of HbF-positive cells and mature erythrocytes, as well as to fewer reticulocytes and sickle cells, in the peripheral blood of treated SCD mice. In keeping with these observations, histological analyses of the liver and spleen o
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the lsd1 inhibitor rn 1 recapitulates the fetal pattern of Hemoglobin Synthesis in baboons p anubis
Haematologica, 2016Co-Authors: Angela Rivers, James Douglas Engel, Kestis Vaitkus, Vinzon Ibanez, Maria Armila Ruiz, Ramaswamy Jagadeeswaran, Joseph Desimone, Yogen Saunthararajah, Donald LavelleAbstract:Increased fetal Hemoglobin levels lessen the severity of symptoms and increase the lifespan of patients with sickle cell disease. Hydroxyurea, the only drug currently approved for the treatment of sickle cell disease, is not effective in a large proportion of patients and therefore new pharmacological agents that increase fetal Hemoglobin levels have long been sought. Recent studies identifying LSD-1 as a repressor of γ-globin expression led to experiments demonstrating that the LSD-1 inhibitor RN-1 increased γ-globin expression in the sickle cell mouse model. Because the arrangement and developmental stage-specific expression pattern of the β-like globin genes is highly conserved between man and baboon, the baboon model remains the best predictor of activity of fetal Hemoglobin-inducing agents in man. In this report, we demonstrate that RN-1 increases γ-globin Synthesis, fetal Hemoglobin, and F cells to high levels in both anemic and non-anemic baboons with activity comparable to decitabine, the most potent fetal Hemoglobin-inducing agent known. RN-1 not only restores high levels of fetal Hemoglobin but causes the individual 5′ Iγ- and 3′ Vγ-globin chains to be synthesized in the ratio characteristic of fetal development. Increased fetal Hemoglobin was associated with increased levels of acetylated Histone H3, H3K4Me2, H3K4Me3, and RNA polymerase II at the γ-globin gene, and diminished γ-globin promoter DNA methylation. RN-1 is likely to induce clinically relevant levels of fetal Hemoglobin in patients with sickle cell disease, although careful titration of the dose may be required to minimize myelotoxicity.
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the lsd1 inhibitor rn 1 recapitulates the fetal pattern of Hemoglobin Synthesis in anemic and normal non anemic baboons
Blood, 2015Co-Authors: Angela Rivers, Kestis Vaitkus, Vinzon Ibanez, Maria Armila Ruiz, Ramaswamy Jagadeeswaran, Joseph Desimone, Donald LavelleAbstract:Increased fetal Hemoglobin (HbF) levels lessen the severity of symptoms and increase the lifespan of patients with sickle cell disease (SCD). Hydroxyurea (HU), the only drug approved for the treatment of sickle cell disease, increases HbF levels, reduces pain crises, and increases the lifespan of patients. Because HU is not effective in a large proportion of patients, new pharmacological agents that increase HbF levels have long been sought. Recent studies identifying LSD-1 as a repressor of γ-globin expression led to experiments demonstrating that the LSD-1 inhibitor RN-1 increased γ-globin expression in SCD mice. As the arrangement and developmental stage-specific expression pattern of the β-like globin genes is highly conserved between man and baboon, the baboon remains the best predictor of the activity of HbF-inducing agents in man. Therefore, experiments were performed to test the effect of RN-1 on HbF in anemic baboons. Anemia (Hct=20) was induced by repeated phlebotomies for 14 days prior to administration of RN-1. Five anemic baboons were treated with varying doses of RN-1(0.125-2.5 mg/kg/d; 5d; sc). Dose-dependent increases in HbF, F cells, F retics, and γ-globin chain Synthesis in reticulocytes were associated with decreased neutrophils and increased monocytes. Globin chain Synthesis analysis following RN-1 treatment showed that the 5' Iγ and 3' Vγ-globin genes were expressed in the ratio characteristic of fetal development (5'Iγ/3'Vγ>2) rather than that induced in adults by erythropoietic stress (5'Iγ/3'Vγ<0.5) or decitabine treatment where changes in the Iγ/Vγ ratio are observed but the fetal ratio is not attained. RT-PCR analysis of pre-and post-treatment BM showed that RN-1 increased γ-globin mRNA nearly 5 fold (p<0.05) with no effect on e-globin mRNA. ChIP analysis of pre- and post-treatment BM erythroid cells showed increased levels of pol II, H3K9ac, H3K4me2 and H3K4me3 associated with the γ-globin but not with the e- or β-globin promoter and IVS II regions consistent with increased γ-globin transcription. Levels of H3K9me2 were increased at the β-globin promoter and IVSII regions. Bisulfite sequence analysis showed a small decrease in level of DNA methylation of the γ-globin promoter in post-treatment (0.68+0.07% total cytosine) compared to pre-treatment (0.79+0.05%; p<0.05). To investigate whether induction of γ-globin expression was dependent on erythropoietic stress, four normal, non-anemic baboons were treated with varying doses and schedules of RN-1 (0.2-0.5mg/kg/d; 5d/wk; 1-10wks; sc). The effect of RN-1 was measured by analysis of F cells and globin chain Synthesis in peripheral blood. The results (Table) show that RN-1 increases γ-globin expression and F cells in normal, non-anemic baboons in a dose-dependent manner. Analysis of globin chain Synthesis showed predominant Synthesis of the Iγ-globin chain with an Iγ/Vγ ratio exceeding the fetal ratio in all individuals. Effect of RN-1 in Normal, Non-Anemic Baboons | Animal | RN-1 Dose (mg/kg/d) | Schedule | Globin chain Synthesis (γ/γ+β) | Iγ/Vγ chain Synthesis | F cells (%) | ANC (/μl) | Plt(X103/μl) | Mono(%) | | ------ | ------------------- | ------------ | ------------------------------ | --------------------- | ----------- | --------- | ------------ | ------- | ----- | | | | | Pre | Post | | Pre | Post | Nadir | Nadir | Peak | | 8549 | 0.5 | 5d | 0.03 | 0.71 | 4.63 | ND | ND | 1910 | 169 | 21.6 | | 8549 | 0.25 | 5d | 0.01 | 0.26 | 4.47 | ND | ND | 1910 | 219 | 14.5 | | 8698 | 0.25 | 5d/wk/2 wks | 0.01 | 0.20 | 20.1 | 2.0 | 9.2 | 1210 | 68 | 7.9 | | 8696 | 0.2-0.25 | 5d/wk/10 wks | ND | 0.10 | 6.63 | 3.5 | 26.8 | 1440 | 64 | 6.1 | Table. Neutropenia following RN-1 treatment of anemic baboons (mean ANC nadir=746±156) was reduced in non-anemic animals (2 of 4 baboons >1500; mean ANC nadir=1617±350; p<0.02). Increased monocytes and decreased platelet counts were observed. Differences between anemic and non-anemic baboons may reflect perturbation of hematopoietic differentiation by phlebotomy. We conclude that RN-1 is a powerful in vivo inducer of HbF in both anemic and non-anemic baboons that preferentially increases Synthesis of the 5' Iγ-globin gene and recapitulates the fetal pattern of Hemoglobin Synthesis. Our data predicts that RN-1 treatment will induce clinically relevant levels of HbF in SCD patients, although careful titration of dose may be required to minimize effects on hematopoiesis. Disclosures No relevant conflicts of interest to declare.
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the lsd1 inhibitor rn 1 induces fetal Hemoglobin Synthesis and reduces disease pathology in sickle cell mice
Blood, 2015Co-Authors: Natee Jearawiriyapaisarn, Greggory Myers, Angela Rivers, Joseph Desimone, Donald Lavelle, Raymond C. Trievel, Andrew Campbell, David Harro, Shigeki Iwase, Yogen SaunthararajahAbstract:Inhibition of lysine-specific demethylase 1 (LSD1) has been shown to induce fetal Hemoglobin (HbF) levels in cultured human erythroid cells in vitro. Here we report the in vivo effects of LSD1 inactivation by a selective and more potent inhibitor, RN-1, in a sickle cell disease (SCD) mouse model. Compared with untreated animals, RN-1 administration leads to induced HbF Synthesis and to increased frequencies of HbF-positive cells and mature erythrocytes, as well as fewer reticulocytes and sickle cells, in the peripheral blood of treated SCD mice. In keeping with these observations, histologic analyses of the liver and spleen of treated SCD mice verified that they do not exhibit the necrotic lesions that are usually associated with SCD. These data indicate that RN-1 can effectively induce HbF levels in red blood cells and reduce disease pathology in SCD mice, and may therefore offer new therapeutic possibilities for treating SCD.
James Douglas Engel - One of the best experts on this subject based on the ideXlab platform.
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inhibition of lsd1 by small molecule inhibitors stimulates fetal Hemoglobin Synthesis
Blood, 2019Co-Authors: Cuong Quang Le, David H K Chui, Greggory Myers, Alawi Habara, Natee Jearawiriyapaisarn, George J Murphy, Martin H. Steinberg, James Douglas EngelAbstract:TO THE EDITOR: Increased fetal Hemoglobin (HbF) leads to diminished severity of sickle cell disease (SCD), as HbF disrupts deoxygenated sickle Hemoglobin polymerization.[1][1] Many efforts have been made to identify an effective way to increase HbF in adults that include using chemical inducers,[2
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LSD1 inhibitor RN-1 stimulates HbF Synthesis 1
2016Co-Authors: Raymond C. Trievel, Angela Rivers, Joseph Desimone, Donald Lavelle, Yogen Saunthararajah, James Douglas EngelAbstract:Key Points 1. RN-1 treatment of SCD mice results in increased human fetal γ-globin induction and fetal Hemoglobin Synthesis. 2. RN-1 treatment of SCD mice significantly reduces sickling, hemolysis and tissue injury with no obvious adverse side effects. Inhibition of lysine-specific demethylase 1 (LSD1) has been shown to induce fetal Hemoglobin (HbF) levels in cultured human erythroid cells in vitro. Here we report the in vivo effects of LSD1 inactivation by a selective and more potent inhibitor, RN-1, in a sickle cell disease (SCD) mouse model. Compared to untreated animals, RN-1 administration leads to induced HbF Synthesis and to increased frequencies of HbF-positive cells and mature erythrocytes, as well as to fewer reticulocytes and sickle cells, in the peripheral blood of treated SCD mice. In keeping with these observations, histological analyses of the liver and spleen o
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the lsd1 inhibitor rn 1 recapitulates the fetal pattern of Hemoglobin Synthesis in baboons p anubis
Haematologica, 2016Co-Authors: Angela Rivers, James Douglas Engel, Kestis Vaitkus, Vinzon Ibanez, Maria Armila Ruiz, Ramaswamy Jagadeeswaran, Joseph Desimone, Yogen Saunthararajah, Donald LavelleAbstract:Increased fetal Hemoglobin levels lessen the severity of symptoms and increase the lifespan of patients with sickle cell disease. Hydroxyurea, the only drug currently approved for the treatment of sickle cell disease, is not effective in a large proportion of patients and therefore new pharmacological agents that increase fetal Hemoglobin levels have long been sought. Recent studies identifying LSD-1 as a repressor of γ-globin expression led to experiments demonstrating that the LSD-1 inhibitor RN-1 increased γ-globin expression in the sickle cell mouse model. Because the arrangement and developmental stage-specific expression pattern of the β-like globin genes is highly conserved between man and baboon, the baboon model remains the best predictor of activity of fetal Hemoglobin-inducing agents in man. In this report, we demonstrate that RN-1 increases γ-globin Synthesis, fetal Hemoglobin, and F cells to high levels in both anemic and non-anemic baboons with activity comparable to decitabine, the most potent fetal Hemoglobin-inducing agent known. RN-1 not only restores high levels of fetal Hemoglobin but causes the individual 5′ Iγ- and 3′ Vγ-globin chains to be synthesized in the ratio characteristic of fetal development. Increased fetal Hemoglobin was associated with increased levels of acetylated Histone H3, H3K4Me2, H3K4Me3, and RNA polymerase II at the γ-globin gene, and diminished γ-globin promoter DNA methylation. RN-1 is likely to induce clinically relevant levels of fetal Hemoglobin in patients with sickle cell disease, although careful titration of the dose may be required to minimize myelotoxicity.
Angela Rivers - One of the best experts on this subject based on the ideXlab platform.
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LSD1 inhibitor RN-1 stimulates HbF Synthesis 1
2016Co-Authors: Raymond C. Trievel, Angela Rivers, Joseph Desimone, Donald Lavelle, Yogen Saunthararajah, James Douglas EngelAbstract:Key Points 1. RN-1 treatment of SCD mice results in increased human fetal γ-globin induction and fetal Hemoglobin Synthesis. 2. RN-1 treatment of SCD mice significantly reduces sickling, hemolysis and tissue injury with no obvious adverse side effects. Inhibition of lysine-specific demethylase 1 (LSD1) has been shown to induce fetal Hemoglobin (HbF) levels in cultured human erythroid cells in vitro. Here we report the in vivo effects of LSD1 inactivation by a selective and more potent inhibitor, RN-1, in a sickle cell disease (SCD) mouse model. Compared to untreated animals, RN-1 administration leads to induced HbF Synthesis and to increased frequencies of HbF-positive cells and mature erythrocytes, as well as to fewer reticulocytes and sickle cells, in the peripheral blood of treated SCD mice. In keeping with these observations, histological analyses of the liver and spleen o
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the lsd1 inhibitor rn 1 recapitulates the fetal pattern of Hemoglobin Synthesis in baboons p anubis
Haematologica, 2016Co-Authors: Angela Rivers, James Douglas Engel, Kestis Vaitkus, Vinzon Ibanez, Maria Armila Ruiz, Ramaswamy Jagadeeswaran, Joseph Desimone, Yogen Saunthararajah, Donald LavelleAbstract:Increased fetal Hemoglobin levels lessen the severity of symptoms and increase the lifespan of patients with sickle cell disease. Hydroxyurea, the only drug currently approved for the treatment of sickle cell disease, is not effective in a large proportion of patients and therefore new pharmacological agents that increase fetal Hemoglobin levels have long been sought. Recent studies identifying LSD-1 as a repressor of γ-globin expression led to experiments demonstrating that the LSD-1 inhibitor RN-1 increased γ-globin expression in the sickle cell mouse model. Because the arrangement and developmental stage-specific expression pattern of the β-like globin genes is highly conserved between man and baboon, the baboon model remains the best predictor of activity of fetal Hemoglobin-inducing agents in man. In this report, we demonstrate that RN-1 increases γ-globin Synthesis, fetal Hemoglobin, and F cells to high levels in both anemic and non-anemic baboons with activity comparable to decitabine, the most potent fetal Hemoglobin-inducing agent known. RN-1 not only restores high levels of fetal Hemoglobin but causes the individual 5′ Iγ- and 3′ Vγ-globin chains to be synthesized in the ratio characteristic of fetal development. Increased fetal Hemoglobin was associated with increased levels of acetylated Histone H3, H3K4Me2, H3K4Me3, and RNA polymerase II at the γ-globin gene, and diminished γ-globin promoter DNA methylation. RN-1 is likely to induce clinically relevant levels of fetal Hemoglobin in patients with sickle cell disease, although careful titration of the dose may be required to minimize myelotoxicity.
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the lsd1 inhibitor rn 1 recapitulates the fetal pattern of Hemoglobin Synthesis in anemic and normal non anemic baboons
Blood, 2015Co-Authors: Angela Rivers, Kestis Vaitkus, Vinzon Ibanez, Maria Armila Ruiz, Ramaswamy Jagadeeswaran, Joseph Desimone, Donald LavelleAbstract:Increased fetal Hemoglobin (HbF) levels lessen the severity of symptoms and increase the lifespan of patients with sickle cell disease (SCD). Hydroxyurea (HU), the only drug approved for the treatment of sickle cell disease, increases HbF levels, reduces pain crises, and increases the lifespan of patients. Because HU is not effective in a large proportion of patients, new pharmacological agents that increase HbF levels have long been sought. Recent studies identifying LSD-1 as a repressor of γ-globin expression led to experiments demonstrating that the LSD-1 inhibitor RN-1 increased γ-globin expression in SCD mice. As the arrangement and developmental stage-specific expression pattern of the β-like globin genes is highly conserved between man and baboon, the baboon remains the best predictor of the activity of HbF-inducing agents in man. Therefore, experiments were performed to test the effect of RN-1 on HbF in anemic baboons. Anemia (Hct=20) was induced by repeated phlebotomies for 14 days prior to administration of RN-1. Five anemic baboons were treated with varying doses of RN-1(0.125-2.5 mg/kg/d; 5d; sc). Dose-dependent increases in HbF, F cells, F retics, and γ-globin chain Synthesis in reticulocytes were associated with decreased neutrophils and increased monocytes. Globin chain Synthesis analysis following RN-1 treatment showed that the 5' Iγ and 3' Vγ-globin genes were expressed in the ratio characteristic of fetal development (5'Iγ/3'Vγ>2) rather than that induced in adults by erythropoietic stress (5'Iγ/3'Vγ<0.5) or decitabine treatment where changes in the Iγ/Vγ ratio are observed but the fetal ratio is not attained. RT-PCR analysis of pre-and post-treatment BM showed that RN-1 increased γ-globin mRNA nearly 5 fold (p<0.05) with no effect on e-globin mRNA. ChIP analysis of pre- and post-treatment BM erythroid cells showed increased levels of pol II, H3K9ac, H3K4me2 and H3K4me3 associated with the γ-globin but not with the e- or β-globin promoter and IVS II regions consistent with increased γ-globin transcription. Levels of H3K9me2 were increased at the β-globin promoter and IVSII regions. Bisulfite sequence analysis showed a small decrease in level of DNA methylation of the γ-globin promoter in post-treatment (0.68+0.07% total cytosine) compared to pre-treatment (0.79+0.05%; p<0.05). To investigate whether induction of γ-globin expression was dependent on erythropoietic stress, four normal, non-anemic baboons were treated with varying doses and schedules of RN-1 (0.2-0.5mg/kg/d; 5d/wk; 1-10wks; sc). The effect of RN-1 was measured by analysis of F cells and globin chain Synthesis in peripheral blood. The results (Table) show that RN-1 increases γ-globin expression and F cells in normal, non-anemic baboons in a dose-dependent manner. Analysis of globin chain Synthesis showed predominant Synthesis of the Iγ-globin chain with an Iγ/Vγ ratio exceeding the fetal ratio in all individuals. Effect of RN-1 in Normal, Non-Anemic Baboons | Animal | RN-1 Dose (mg/kg/d) | Schedule | Globin chain Synthesis (γ/γ+β) | Iγ/Vγ chain Synthesis | F cells (%) | ANC (/μl) | Plt(X103/μl) | Mono(%) | | ------ | ------------------- | ------------ | ------------------------------ | --------------------- | ----------- | --------- | ------------ | ------- | ----- | | | | | Pre | Post | | Pre | Post | Nadir | Nadir | Peak | | 8549 | 0.5 | 5d | 0.03 | 0.71 | 4.63 | ND | ND | 1910 | 169 | 21.6 | | 8549 | 0.25 | 5d | 0.01 | 0.26 | 4.47 | ND | ND | 1910 | 219 | 14.5 | | 8698 | 0.25 | 5d/wk/2 wks | 0.01 | 0.20 | 20.1 | 2.0 | 9.2 | 1210 | 68 | 7.9 | | 8696 | 0.2-0.25 | 5d/wk/10 wks | ND | 0.10 | 6.63 | 3.5 | 26.8 | 1440 | 64 | 6.1 | Table. Neutropenia following RN-1 treatment of anemic baboons (mean ANC nadir=746±156) was reduced in non-anemic animals (2 of 4 baboons >1500; mean ANC nadir=1617±350; p<0.02). Increased monocytes and decreased platelet counts were observed. Differences between anemic and non-anemic baboons may reflect perturbation of hematopoietic differentiation by phlebotomy. We conclude that RN-1 is a powerful in vivo inducer of HbF in both anemic and non-anemic baboons that preferentially increases Synthesis of the 5' Iγ-globin gene and recapitulates the fetal pattern of Hemoglobin Synthesis. Our data predicts that RN-1 treatment will induce clinically relevant levels of HbF in SCD patients, although careful titration of dose may be required to minimize effects on hematopoiesis. Disclosures No relevant conflicts of interest to declare.
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the lsd1 inhibitor rn 1 induces fetal Hemoglobin Synthesis and reduces disease pathology in sickle cell mice
Blood, 2015Co-Authors: Natee Jearawiriyapaisarn, Greggory Myers, Angela Rivers, Joseph Desimone, Donald Lavelle, Raymond C. Trievel, Andrew Campbell, David Harro, Shigeki Iwase, Yogen SaunthararajahAbstract:Inhibition of lysine-specific demethylase 1 (LSD1) has been shown to induce fetal Hemoglobin (HbF) levels in cultured human erythroid cells in vitro. Here we report the in vivo effects of LSD1 inactivation by a selective and more potent inhibitor, RN-1, in a sickle cell disease (SCD) mouse model. Compared with untreated animals, RN-1 administration leads to induced HbF Synthesis and to increased frequencies of HbF-positive cells and mature erythrocytes, as well as fewer reticulocytes and sickle cells, in the peripheral blood of treated SCD mice. In keeping with these observations, histologic analyses of the liver and spleen of treated SCD mice verified that they do not exhibit the necrotic lesions that are usually associated with SCD. These data indicate that RN-1 can effectively induce HbF levels in red blood cells and reduce disease pathology in SCD mice, and may therefore offer new therapeutic possibilities for treating SCD.
Joseph Desimone - One of the best experts on this subject based on the ideXlab platform.
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LSD1 inhibitor RN-1 stimulates HbF Synthesis 1
2016Co-Authors: Raymond C. Trievel, Angela Rivers, Joseph Desimone, Donald Lavelle, Yogen Saunthararajah, James Douglas EngelAbstract:Key Points 1. RN-1 treatment of SCD mice results in increased human fetal γ-globin induction and fetal Hemoglobin Synthesis. 2. RN-1 treatment of SCD mice significantly reduces sickling, hemolysis and tissue injury with no obvious adverse side effects. Inhibition of lysine-specific demethylase 1 (LSD1) has been shown to induce fetal Hemoglobin (HbF) levels in cultured human erythroid cells in vitro. Here we report the in vivo effects of LSD1 inactivation by a selective and more potent inhibitor, RN-1, in a sickle cell disease (SCD) mouse model. Compared to untreated animals, RN-1 administration leads to induced HbF Synthesis and to increased frequencies of HbF-positive cells and mature erythrocytes, as well as to fewer reticulocytes and sickle cells, in the peripheral blood of treated SCD mice. In keeping with these observations, histological analyses of the liver and spleen o
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the lsd1 inhibitor rn 1 recapitulates the fetal pattern of Hemoglobin Synthesis in baboons p anubis
Haematologica, 2016Co-Authors: Angela Rivers, James Douglas Engel, Kestis Vaitkus, Vinzon Ibanez, Maria Armila Ruiz, Ramaswamy Jagadeeswaran, Joseph Desimone, Yogen Saunthararajah, Donald LavelleAbstract:Increased fetal Hemoglobin levels lessen the severity of symptoms and increase the lifespan of patients with sickle cell disease. Hydroxyurea, the only drug currently approved for the treatment of sickle cell disease, is not effective in a large proportion of patients and therefore new pharmacological agents that increase fetal Hemoglobin levels have long been sought. Recent studies identifying LSD-1 as a repressor of γ-globin expression led to experiments demonstrating that the LSD-1 inhibitor RN-1 increased γ-globin expression in the sickle cell mouse model. Because the arrangement and developmental stage-specific expression pattern of the β-like globin genes is highly conserved between man and baboon, the baboon model remains the best predictor of activity of fetal Hemoglobin-inducing agents in man. In this report, we demonstrate that RN-1 increases γ-globin Synthesis, fetal Hemoglobin, and F cells to high levels in both anemic and non-anemic baboons with activity comparable to decitabine, the most potent fetal Hemoglobin-inducing agent known. RN-1 not only restores high levels of fetal Hemoglobin but causes the individual 5′ Iγ- and 3′ Vγ-globin chains to be synthesized in the ratio characteristic of fetal development. Increased fetal Hemoglobin was associated with increased levels of acetylated Histone H3, H3K4Me2, H3K4Me3, and RNA polymerase II at the γ-globin gene, and diminished γ-globin promoter DNA methylation. RN-1 is likely to induce clinically relevant levels of fetal Hemoglobin in patients with sickle cell disease, although careful titration of the dose may be required to minimize myelotoxicity.
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the lsd1 inhibitor rn 1 recapitulates the fetal pattern of Hemoglobin Synthesis in anemic and normal non anemic baboons
Blood, 2015Co-Authors: Angela Rivers, Kestis Vaitkus, Vinzon Ibanez, Maria Armila Ruiz, Ramaswamy Jagadeeswaran, Joseph Desimone, Donald LavelleAbstract:Increased fetal Hemoglobin (HbF) levels lessen the severity of symptoms and increase the lifespan of patients with sickle cell disease (SCD). Hydroxyurea (HU), the only drug approved for the treatment of sickle cell disease, increases HbF levels, reduces pain crises, and increases the lifespan of patients. Because HU is not effective in a large proportion of patients, new pharmacological agents that increase HbF levels have long been sought. Recent studies identifying LSD-1 as a repressor of γ-globin expression led to experiments demonstrating that the LSD-1 inhibitor RN-1 increased γ-globin expression in SCD mice. As the arrangement and developmental stage-specific expression pattern of the β-like globin genes is highly conserved between man and baboon, the baboon remains the best predictor of the activity of HbF-inducing agents in man. Therefore, experiments were performed to test the effect of RN-1 on HbF in anemic baboons. Anemia (Hct=20) was induced by repeated phlebotomies for 14 days prior to administration of RN-1. Five anemic baboons were treated with varying doses of RN-1(0.125-2.5 mg/kg/d; 5d; sc). Dose-dependent increases in HbF, F cells, F retics, and γ-globin chain Synthesis in reticulocytes were associated with decreased neutrophils and increased monocytes. Globin chain Synthesis analysis following RN-1 treatment showed that the 5' Iγ and 3' Vγ-globin genes were expressed in the ratio characteristic of fetal development (5'Iγ/3'Vγ>2) rather than that induced in adults by erythropoietic stress (5'Iγ/3'Vγ<0.5) or decitabine treatment where changes in the Iγ/Vγ ratio are observed but the fetal ratio is not attained. RT-PCR analysis of pre-and post-treatment BM showed that RN-1 increased γ-globin mRNA nearly 5 fold (p<0.05) with no effect on e-globin mRNA. ChIP analysis of pre- and post-treatment BM erythroid cells showed increased levels of pol II, H3K9ac, H3K4me2 and H3K4me3 associated with the γ-globin but not with the e- or β-globin promoter and IVS II regions consistent with increased γ-globin transcription. Levels of H3K9me2 were increased at the β-globin promoter and IVSII regions. Bisulfite sequence analysis showed a small decrease in level of DNA methylation of the γ-globin promoter in post-treatment (0.68+0.07% total cytosine) compared to pre-treatment (0.79+0.05%; p<0.05). To investigate whether induction of γ-globin expression was dependent on erythropoietic stress, four normal, non-anemic baboons were treated with varying doses and schedules of RN-1 (0.2-0.5mg/kg/d; 5d/wk; 1-10wks; sc). The effect of RN-1 was measured by analysis of F cells and globin chain Synthesis in peripheral blood. The results (Table) show that RN-1 increases γ-globin expression and F cells in normal, non-anemic baboons in a dose-dependent manner. Analysis of globin chain Synthesis showed predominant Synthesis of the Iγ-globin chain with an Iγ/Vγ ratio exceeding the fetal ratio in all individuals. Effect of RN-1 in Normal, Non-Anemic Baboons | Animal | RN-1 Dose (mg/kg/d) | Schedule | Globin chain Synthesis (γ/γ+β) | Iγ/Vγ chain Synthesis | F cells (%) | ANC (/μl) | Plt(X103/μl) | Mono(%) | | ------ | ------------------- | ------------ | ------------------------------ | --------------------- | ----------- | --------- | ------------ | ------- | ----- | | | | | Pre | Post | | Pre | Post | Nadir | Nadir | Peak | | 8549 | 0.5 | 5d | 0.03 | 0.71 | 4.63 | ND | ND | 1910 | 169 | 21.6 | | 8549 | 0.25 | 5d | 0.01 | 0.26 | 4.47 | ND | ND | 1910 | 219 | 14.5 | | 8698 | 0.25 | 5d/wk/2 wks | 0.01 | 0.20 | 20.1 | 2.0 | 9.2 | 1210 | 68 | 7.9 | | 8696 | 0.2-0.25 | 5d/wk/10 wks | ND | 0.10 | 6.63 | 3.5 | 26.8 | 1440 | 64 | 6.1 | Table. Neutropenia following RN-1 treatment of anemic baboons (mean ANC nadir=746±156) was reduced in non-anemic animals (2 of 4 baboons >1500; mean ANC nadir=1617±350; p<0.02). Increased monocytes and decreased platelet counts were observed. Differences between anemic and non-anemic baboons may reflect perturbation of hematopoietic differentiation by phlebotomy. We conclude that RN-1 is a powerful in vivo inducer of HbF in both anemic and non-anemic baboons that preferentially increases Synthesis of the 5' Iγ-globin gene and recapitulates the fetal pattern of Hemoglobin Synthesis. Our data predicts that RN-1 treatment will induce clinically relevant levels of HbF in SCD patients, although careful titration of dose may be required to minimize effects on hematopoiesis. Disclosures No relevant conflicts of interest to declare.
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the lsd1 inhibitor rn 1 induces fetal Hemoglobin Synthesis and reduces disease pathology in sickle cell mice
Blood, 2015Co-Authors: Natee Jearawiriyapaisarn, Greggory Myers, Angela Rivers, Joseph Desimone, Donald Lavelle, Raymond C. Trievel, Andrew Campbell, David Harro, Shigeki Iwase, Yogen SaunthararajahAbstract:Inhibition of lysine-specific demethylase 1 (LSD1) has been shown to induce fetal Hemoglobin (HbF) levels in cultured human erythroid cells in vitro. Here we report the in vivo effects of LSD1 inactivation by a selective and more potent inhibitor, RN-1, in a sickle cell disease (SCD) mouse model. Compared with untreated animals, RN-1 administration leads to induced HbF Synthesis and to increased frequencies of HbF-positive cells and mature erythrocytes, as well as fewer reticulocytes and sickle cells, in the peripheral blood of treated SCD mice. In keeping with these observations, histologic analyses of the liver and spleen of treated SCD mice verified that they do not exhibit the necrotic lesions that are usually associated with SCD. These data indicate that RN-1 can effectively induce HbF levels in red blood cells and reduce disease pathology in SCD mice, and may therefore offer new therapeutic possibilities for treating SCD.
Yogen Saunthararajah - One of the best experts on this subject based on the ideXlab platform.
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LSD1 inhibitor RN-1 stimulates HbF Synthesis 1
2016Co-Authors: Raymond C. Trievel, Angela Rivers, Joseph Desimone, Donald Lavelle, Yogen Saunthararajah, James Douglas EngelAbstract:Key Points 1. RN-1 treatment of SCD mice results in increased human fetal γ-globin induction and fetal Hemoglobin Synthesis. 2. RN-1 treatment of SCD mice significantly reduces sickling, hemolysis and tissue injury with no obvious adverse side effects. Inhibition of lysine-specific demethylase 1 (LSD1) has been shown to induce fetal Hemoglobin (HbF) levels in cultured human erythroid cells in vitro. Here we report the in vivo effects of LSD1 inactivation by a selective and more potent inhibitor, RN-1, in a sickle cell disease (SCD) mouse model. Compared to untreated animals, RN-1 administration leads to induced HbF Synthesis and to increased frequencies of HbF-positive cells and mature erythrocytes, as well as to fewer reticulocytes and sickle cells, in the peripheral blood of treated SCD mice. In keeping with these observations, histological analyses of the liver and spleen o
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the lsd1 inhibitor rn 1 recapitulates the fetal pattern of Hemoglobin Synthesis in baboons p anubis
Haematologica, 2016Co-Authors: Angela Rivers, James Douglas Engel, Kestis Vaitkus, Vinzon Ibanez, Maria Armila Ruiz, Ramaswamy Jagadeeswaran, Joseph Desimone, Yogen Saunthararajah, Donald LavelleAbstract:Increased fetal Hemoglobin levels lessen the severity of symptoms and increase the lifespan of patients with sickle cell disease. Hydroxyurea, the only drug currently approved for the treatment of sickle cell disease, is not effective in a large proportion of patients and therefore new pharmacological agents that increase fetal Hemoglobin levels have long been sought. Recent studies identifying LSD-1 as a repressor of γ-globin expression led to experiments demonstrating that the LSD-1 inhibitor RN-1 increased γ-globin expression in the sickle cell mouse model. Because the arrangement and developmental stage-specific expression pattern of the β-like globin genes is highly conserved between man and baboon, the baboon model remains the best predictor of activity of fetal Hemoglobin-inducing agents in man. In this report, we demonstrate that RN-1 increases γ-globin Synthesis, fetal Hemoglobin, and F cells to high levels in both anemic and non-anemic baboons with activity comparable to decitabine, the most potent fetal Hemoglobin-inducing agent known. RN-1 not only restores high levels of fetal Hemoglobin but causes the individual 5′ Iγ- and 3′ Vγ-globin chains to be synthesized in the ratio characteristic of fetal development. Increased fetal Hemoglobin was associated with increased levels of acetylated Histone H3, H3K4Me2, H3K4Me3, and RNA polymerase II at the γ-globin gene, and diminished γ-globin promoter DNA methylation. RN-1 is likely to induce clinically relevant levels of fetal Hemoglobin in patients with sickle cell disease, although careful titration of the dose may be required to minimize myelotoxicity.
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the lsd1 inhibitor rn 1 induces fetal Hemoglobin Synthesis and reduces disease pathology in sickle cell mice
Blood, 2015Co-Authors: Natee Jearawiriyapaisarn, Greggory Myers, Angela Rivers, Joseph Desimone, Donald Lavelle, Raymond C. Trievel, Andrew Campbell, David Harro, Shigeki Iwase, Yogen SaunthararajahAbstract:Inhibition of lysine-specific demethylase 1 (LSD1) has been shown to induce fetal Hemoglobin (HbF) levels in cultured human erythroid cells in vitro. Here we report the in vivo effects of LSD1 inactivation by a selective and more potent inhibitor, RN-1, in a sickle cell disease (SCD) mouse model. Compared with untreated animals, RN-1 administration leads to induced HbF Synthesis and to increased frequencies of HbF-positive cells and mature erythrocytes, as well as fewer reticulocytes and sickle cells, in the peripheral blood of treated SCD mice. In keeping with these observations, histologic analyses of the liver and spleen of treated SCD mice verified that they do not exhibit the necrotic lesions that are usually associated with SCD. These data indicate that RN-1 can effectively induce HbF levels in red blood cells and reduce disease pathology in SCD mice, and may therefore offer new therapeutic possibilities for treating SCD.