| 1. |
- Flygare, Johan, et al.
(författare)
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Deficiency of ribosomal protein S19 in CD34+ cells generated by siRNA blocks erythroid development and mimics defects seen in Diamond-Blackfan anemia
- 2005
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Ingår i: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 105:12, s. 4627-4634
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Tidskriftsartikel (refereegranskat)abstract
- Diamond-Blackfan anemia (DBA) is a congenital red cell aplasia in which 25% of the patients have a mutation in the ribosomal protein S19 (RPS19) gene. To study effects of RPS19 deficiency in hematopoiesis we transduced CD34+ umbilical cord blood (CB) and bone marrow (BM) cells with 3 lentiviral vectors expressing small interfering RNA (siRNA) against RPS19 and 1 scrambled control vector. All vectors also express green fluorescent protein (GFP). Transduction with the siRNA vectors reduced RPS19 mRNA levels to various degrees, which resulted in erythroid defects, correlating to the degree of RPS19 down-regulation, and was rescued by expression of an siRNA-resistant RPS19 transcript. Erythroid colony formation capacity conjointly decreased with RPS19 levels in CD34+ CB and BM cells. In liquid culture supporting erythroid differentiation, RPS19-silenced as well as DBA patient CD34+ cells exhibited reduced proliferative capacity and impaired erythroid differentiation resulting in fewer erythroid colony-forming units (CFU-Es). When assaying myeloid development, a less pronounced influence on proliferation was seen. This study shows for the first time that RPS19 silencing decreases the proliferative capacity of hematopoietic progenitors and leads to a defect in erythroid development.
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| 2. |
- Hamaguchi, Isao, et al.
(författare)
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Gene transfer improves erythroid development in ribosomal protein S19-deficient Diamond-Blackfan anemia.
- 2002
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Ingår i: Blood. - 1528-0020. ; 100:8, s. 2724-2731
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Tidskriftsartikel (refereegranskat)abstract
- Diamond-Blackfan anemia (DBA) is a congenital bone marrow failure syndrome characterized by a specific deficiency in erythroid progenitors. Forty percent of the patients are blood transfusion-dependent. Recent reports show that the ribosomal protein S19 (RPS19) gene is mutated in 25% of all patients with DBA. We constructed oncoretroviral vectors containing the RPS19 gene to develop gene therapy for RPS19-deficient DBA. These vectors were used to introduce the RPS19 gene into CD34(+) bone marrow (BM) cells from 4 patients with DBA with RPS19 gene mutations. Overexpression of the RPS19 transgene increased the number of erythroid colonies by almost 3-fold. High expression levels of the RPS19 transgene improved erythroid colony-forming ability substantially whereas low expression levels had no effect. Overexpression of RPS19 had no detrimental effect on granulocyte-macrophage colony formation. Therefore, these findings suggest that gene therapy for RPS19-deficient patients with DBA using viral vectors that express the RPS19 gene is feasible. (Blood. 2002;100:2724-2731)
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| 3. |
- Hamaguchi, Isao, et al.
(författare)
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Proliferation deficiency of multipotent hematopoietic progenitors in ribosomal protein S19 (RPS19)-deficient Diamond-Blackfan anemia improves following RPS19 gene transfer
- 2003
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Ingår i: Molecular Therapy. - 1525-0024. ; 7:5, s. 613-622
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Tidskriftsartikel (refereegranskat)abstract
- Diamond-Blackfan anemia (DBA) is a congenital bone marrow failure syndrome characterized by a specific deficiency in erythroid progenitors. Since some patients with DBA develop a reduction in thrombocytes and granulocytes with age, we asked whether multipotent hematopoietic progenitors from DBA patients had normal proliferative capacity in liquid expansion cultures. CD34(+) cells derived from DBA patients showed deficient proliferation in liquid culture containing IL-3, IL-6, and SCF. Single CD34(+) CD38(-) cells from DBA patients exhibited deficient proliferation recruitment in a limiting dilution assay containing IL-3, IL-6, SCF, Tpo, FIL, and G-CSF or containing IL-3, IL-6, and SCF. Our findings suggest that the underlying hematopoietic defect in DBA may not be limited to the erythroid lineage. Since a fraction of DBA patients have a deficiency in ribosomal protein S19 (RPS19), we constructed lentiviral vectors containing the RPS19 gene for overexpression in hematopoietic progenitors from RPS19-deficient DBA patients. Enforced expression of the RPS19 transgene improved the proliferation of CD34(+) cells from DBA patients with RPS19 mutation. Similarly, enforced expression of RPS19 improved erythroid development of RPS19-deficient hematopoietic progenitors as determined by colony assays and erythroid differentiation cultures. These findings suggest that gene therapy for RPS19-deficient DBA is feasible.
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| 4. |
- Matsson, Hans, et al.
(författare)
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Targeted disruption of the ribosomal protein S19 gene is lethal prior to implantation.
- 2004
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Ingår i: Mol Cell Biol. - 0270-7306. ; 24:9, s. 4032-4037
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Tidskriftsartikel (refereegranskat)abstract
- The ribosomal protein S19 (RPS19) is located in the small (40S) subunit and is one of 79 ribosomal proteins. The gene encoding RPS19 is mutated in approximately 25% of patients with Diamond-Blackfan anemia, which is a rare congenital erythroblastopenia. Affected individuals present with decreased numbers or the absence of erythroid precursors in the bone marrow, and associated malformations of various organs are common. We produced C57BL/6J mice with a targeted disruption of murine Rps19 to study its role in erythropoiesis and development. Mice homozygous for the disrupted Rps19 were not identified as early as the blastocyst stage, indicating a lethal effect. In contrast, mice heterozygous for the disrupted Rps19 allele have normal growth and organ development, including that of the hematopoietic system. Our findings indicate that zygotes which are Rps19(-/-) do not form blastocysts, whereas one normal Rps19 allele in C57BL/6J mice is sufficient to maintain normal ribosomal and possibly extraribosomal functions.
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| 5. |
- Miyake, Koichi, et al.
(författare)
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RPS19 Deficiency Leads to Reduced Proliferation and Increased Apoptosis but Does Not Affect Terminal Erythroid Differentiation in a Cell Line Model of Diamond-Blackfan Anemia
- 2008
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Ingår i: Stem Cells. - : Oxford University Press (OUP). - 1549-4918 .- 1066-5099. ; 26:2, s. 323-329
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Tidskriftsartikel (refereegranskat)abstract
- Diamond-Blackfan anemia (DBA) is a congenital red cell aplasia in which 25% of the patients have a mutation in the ribosomal protein (RP) S19 gene. It is not known how the RPS19 deficiency impairs erythropoiesis and proliferation of hematopoietic progenitors. To elucidate molecular mechanisms in RPS19 deficient DBA, we analyzed the effects of RPS19 deficiency on EPO induced signal transduction, cell cycle, and apoptosis in RPS19-deficient TF-1 cells. We did not find any abnormality in EPO induced signal transduction. However, RPS19 deficient-TF-1 cells showed G0/G1 arrest (82% vs 58%, p<0.05) together with accumulation of p21 and p27. The fraction of apoptotic cells detected by Annexin-V analysis also increased compared to control cells (13% vs 3.1%, p<0.05). Western blot analysis of apoptotic related proteins showed that the level of bcl-2 and Bad was decreased and Bax was increased in RPS19-deficient TF1 cells. Moreover, primary CD34 positive cells from DBA patients detected by Annexin-V analysis also generated a higher number of apoptotic cells compared to normal CD34 positive cells during in vitro culture (38% vs 8.9%, n=5, p<0.001). Finally, we show that while RPS19 silencing reduces EPO induced development of erythroid progenitors expressing Glycophorin A (GPA), RPS19 silencing in cells already expressing GPA does not affect GPA expression. These findings indicate that RPS19 deficiency causes apoptosis and accelerated loss of erythroid progenitors in RPS19 deficient DBA.
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