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Modeling Diamond-Blackfan Anemia in the Mouse: Disease Pathogenesis and Evaluation of Novel Therapies

Jaako, Pekka LU (2012) In Lund University, Faculty of Medicine Doctoral Dissertation Series 2012:83.
Abstract
Diamond-Blackfan anemia (DBA) is a congenital erythroid hypoplasia that presents early in infancy. The main hematopoietic symptoms include macrocytic anemia with reticulocytopenia and selective absence of erythroid precursors in a normocellular bone marrow. In addition to the hematopoietic symptoms, DBA is characterized by the presence of physical abnormalities and cancer predisposition. Mutations in genes encoding ribosomal proteins have been identified in approximately 60-70% of DBA patients. Among these genes, ribosomal protein S19 (RPS19) is the most common disease gene (25% of the cases). All reported patients are heterozygous for the mutations and in most cases the mutations are predicted to result in haploinsufficiency of the... (More)
Diamond-Blackfan anemia (DBA) is a congenital erythroid hypoplasia that presents early in infancy. The main hematopoietic symptoms include macrocytic anemia with reticulocytopenia and selective absence of erythroid precursors in a normocellular bone marrow. In addition to the hematopoietic symptoms, DBA is characterized by the presence of physical abnormalities and cancer predisposition. Mutations in genes encoding ribosomal proteins have been identified in approximately 60-70% of DBA patients. Among these genes, ribosomal protein S19 (RPS19) is the most common disease gene (25% of the cases). All reported patients are heterozygous for the mutations and in most cases the mutations are predicted to result in haploinsufficiency of the respective ribosomal protein.

Knowledge about DBA pathophysiology has been limited due to lack of appropriate animal models. The aim of this thesis was to generate mouse models for RPS19-deficient DBA and to use these models to study DBA pathophysiology and to evaluate novel therapies. In article I we generated and characterized novel mouse models for RPS19-deficient DBA. These models contain a doxycycline-regulatable Rps19-targeting shRNA that allows an inducible and graded downregulation of Rps19. We demonstrate that Rps19-deficient mice recapitulate many of the phenotypic and molecular features seen in patients, and are therefore well suited for the evaluation of novel therapies. In article II we used these mouse models to assess the therapeutic potential of the amino acid L-leucine in the treatment of DBA. We show that L-leucine treatment improves the anemia and alleviates the stress hematopoiesis in Rps19-deficient mice. In article III we evaluated the therapeutic efficacy of gene therapy using our mouse models for RPS19-deficient DBA. Using lentiviral vectors we demonstrate that enforced expression of RPS19 cures the lethal bone marrow failure in recipient mice transplanted with Rps19-deficient bone marrow cells.

Taking together the generated mouse models provide novel tools to study DBA pathophysiology and to evaluate novel therapies. Our studies strengthen the rationale for clinical trials of L-leucine and provide a proof of principle for the development of clinical gene therapy in the treatment of RPS19-deficient DBA. (Less)
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author
supervisor
opponent
  • MD, PhD Ebert, Benjamin, Harvard Medical School
organization
publishing date
type
Thesis
publication status
published
subject
in
Lund University, Faculty of Medicine Doctoral Dissertation Series
volume
2012:83
pages
76 pages
publisher
Division of Molecular Medicine and Gene Therapy
defense location
Lundmarksalen, Astronomihuset, Sölvegatan 27, Lund
defense date
2012-10-25 09:00
ISSN
1652-8220
ISBN
978-91-87189-46-3
language
English
LU publication?
yes
id
a0ede642-1dc5-43f9-aab7-1a2cef01ef79 (old id 3122575)
date added to LUP
2012-09-28 14:40:12
date last changed
2016-09-19 08:44:47
@phdthesis{a0ede642-1dc5-43f9-aab7-1a2cef01ef79,
  abstract     = {Diamond-Blackfan anemia (DBA) is a congenital erythroid hypoplasia that presents early in infancy. The main hematopoietic symptoms include macrocytic anemia with reticulocytopenia and selective absence of erythroid precursors in a normocellular bone marrow. In addition to the hematopoietic symptoms, DBA is characterized by the presence of physical abnormalities and cancer predisposition. Mutations in genes encoding ribosomal proteins have been identified in approximately 60-70% of DBA patients. Among these genes, ribosomal protein S19 (RPS19) is the most common disease gene (25% of the cases). All reported patients are heterozygous for the mutations and in most cases the mutations are predicted to result in haploinsufficiency of the respective ribosomal protein. <br/><br>
Knowledge about DBA pathophysiology has been limited due to lack of appropriate animal models. The aim of this thesis was to generate mouse models for RPS19-deficient DBA and to use these models to study DBA pathophysiology and to evaluate novel therapies. In article I we generated and characterized novel mouse models for RPS19-deficient DBA. These models contain a doxycycline-regulatable Rps19-targeting shRNA that allows an inducible and graded downregulation of Rps19. We demonstrate that Rps19-deficient mice recapitulate many of the phenotypic and molecular features seen in patients, and are therefore well suited for the evaluation of novel therapies. In article II we used these mouse models to assess the therapeutic potential of the amino acid L-leucine in the treatment of DBA. We show that L-leucine treatment improves the anemia and alleviates the stress hematopoiesis in Rps19-deficient mice. In article III we evaluated the therapeutic efficacy of gene therapy using our mouse models for RPS19-deficient DBA. Using lentiviral vectors we demonstrate that enforced expression of RPS19 cures the lethal bone marrow failure in recipient mice transplanted with Rps19-deficient bone marrow cells. <br/><br>
Taking together the generated mouse models provide novel tools to study DBA pathophysiology and to evaluate novel therapies. Our studies strengthen the rationale for clinical trials of L-leucine and provide a proof of principle for the development of clinical gene therapy in the treatment of RPS19-deficient DBA.},
  author       = {Jaako, Pekka},
  isbn         = {978-91-87189-46-3},
  issn         = {1652-8220},
  language     = {eng},
  pages        = {76},
  publisher    = {Division of Molecular Medicine and Gene Therapy},
  school       = {Lund University},
  series       = {Lund University, Faculty of Medicine Doctoral Dissertation Series},
  title        = {Modeling Diamond-Blackfan Anemia in the Mouse: Disease Pathogenesis and Evaluation of Novel Therapies},
  volume       = {2012:83},
  year         = {2012},
}