| 1. |
- Askmyr, Maria K, et al.
(författare)
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Towards a better understanding and new therapeutics of osteopetrosis.
- 2008
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Ingår i: British journal of haematology. - : Wiley. - 1365-2141 .- 0007-1048. ; 140:6, s. 597-609
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Forskningsöversikt (refereegranskat)abstract
- Lack of or dysfunction in osteoclasts result in osteopetrosis, a group of rare but often severe, genetic disorders affecting skeletal tissue. Increase in bone mass results in skeletal malformation and bone marrow failure that may be fatal. Many of the underlying defects have lately been characterized in humans and in animal models of the disease. In humans, these defects often involve mutations in genes expressing proteins involved in the acidification of the osteoclast resorption compartment, a process necessary for proper bone degradation. So far, the only cure for children with severe osteopetrosis is allogeneic hematopoietic stem cell (HSC) transplantation but without a matching donor this form of therapy is far from optimal. The characterization of the genetic defects opens up the possibility for gene replacement therapy as an alternative. Accordingly, HSC-targeted gene therapy in a mouse model of infantile malignant osteopetrosis was recently shown to correct many aspects of the disease.
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| 2. |
- Askmyr, Maria, et al.
(författare)
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Prospects for gene therapy of osteopetrosis.
- 2009
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Ingår i: Current gene therapy. - 1566-5232. ; 9:3, s. 150-9
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Forskningsöversikt (refereegranskat)abstract
- Dysfunction in or lack of osteoclasts result in osteopetrosis, a group of rare but often severe, genetic disorders characterized by an increase in bone mass, skeletal malformations and bone marrow failure that may be fatal. Several of the underlying defects have lately been characterized in humans and in animal disease models. In humans, these defects often involve mutations in genes expressing proteins involved in the acidification of the osteoclast sub-cellular compartment, a process necessary for proper bone resorption. So far, the only cure for children with severe osteopetrosis is allogeneic hematopoietic stem cell transplantation (SCT). However, the characterization of the genetic defects opens up the possibility for gene replacement therapy as an alternative to SCT. Recently, gene therapy targeting hematopoietic stem cells (HSC) in a mouse model of infantile malignant osteopetrosis was shown to correct many aspects of the disease. Here we review important aspects of this group of diseases and discuss the prospects for development of gene therapy of osteopetrosis.
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| 3. |
- Johansson, M. K., et al.
(författare)
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Hematopoietic stem cell-targeted neonatal gene therapy reverses lethally progressive osteopetrosis in oc/oc mice
- 2007
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Ingår i: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 109:12, s. 5178-85
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Tidskriftsartikel (refereegranskat)abstract
- Infantile malignant osteopetrosis (IMO) is a fatal disease caused by lack of functional osteoclasts, and the only available treatment is hematopoietic stem cell (HSC) transplantation. In the majority of patients, the TCIRG1 gene, coding for a subunit of a proton pump essential for bone resorption, is mutated. Oc/oc mice have a deletion in the homologue gene (tcirg1) and die at 3 to 4 weeks, but can be rescued by neonatal transplantation of HSCs. Here, HSC-targeted gene therapy of osteopetrosis in the oc/oc mouse model was developed. Oc/oc fetal liver cells depleted of Ter119-expressing erythroid cells were transduced with a retroviral vector expressing tcirg1 and GFP, and subsequently transplanted intraperitoneally to irradiated neonatal oc/oc mice. Eight of 15 mice survived past the normal life span of oc/oc mice. In vitro osteoclastogenesis revealed formation of GFP-positive osteoclasts and bone resorption, albeit at a lower level than from wild-type cells. The skeletal phenotype was analyzed by X-ray and histopathology and showed partial correction at 8 weeks and almost normalization after 18 weeks. In summary, osteopetrosis in oc/oc mice can be reversed by neonatal transplantation of gene-modified HSCs leading to long-term survival. This represents a significant step toward the development of gene therapy for osteopetrosis.
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| 4. |
- Johansson, M., et al.
(författare)
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Neonatal hematopoietic stem cell transplantation cures oc/oc mice from osteopetrosis
- 2006
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Ingår i: Exp Hematol. - : Elsevier BV. - 0301-472X .- 1873-2399. ; 34:2, s. 242-9
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Infantile malignant osteopetrosis (IMO) is a rare autosomal recessive disorder affecting osteoclast function. Fifty percent of the patients have a mutation in the TCIRG1 gene coding for one subunit of an osteoclast proton pump. The only curative treatment is hematopoietic stem cell transplantation (SCT). The oc/oc mouse has a mutation in the gene homologous to TCIRG1 and its expected lifespan is only 3 to 4 weeks. Previous attempts to cure these mice with SCT have been unsuccessful. We wanted to determine if early hematopoietic SCT using enriched and MHC-matched stem cells can cure oc/oc mice from osteopetrosis. METHODS: One- and 8-day-old oc/oc and control mice were radiated with 200, 400, or 600 cGy and transplanted intraperitoneally with 1 or 5 x 10(6) normal lineage-depleted bone marrow cells. Blood, x-ray, and pathology analyses were performed on transplanted mice. RESULTS: All 1-day-old mice irradiated with 400 cGy and transplanted with 5 x 10(6) cells survived long term. An engraftment level of 20% is sufficient to correct most features of the disease. X-ray and histopathology examination of transplanted animals showed normalization of bone structure. However, although a correction of bone structure occurred, the transplanted oc/oc mice were smaller in size than their littermates. In contrast to untreated animals, oc/oc mice developed teeth after transplantation, but with abnormal structure and shape making them unusable. CONCLUSION: We have shown that this murine form of IMO is curable with neonatal SCT using enriched stem cells.
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| 5. |
- Moscatelli, Ilana, et al.
(författare)
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Lentiviral gene transfer of TCIRG1 into peripheral blood CD34(+) cells restores osteoclast function in infantile malignant osteopetrosis.
- 2013
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Ingår i: Bone. - : Elsevier BV. - 1873-2763 .- 8756-3282. ; 57:1, s. 1-9
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Tidskriftsartikel (refereegranskat)abstract
- Infantile malignant osteopetrosis (IMO) is a rare, lethal, autosomal recessive disorder characterized by non-functional osteoclasts. More than 50% of the patients have mutations in the TCIRG1 gene, encoding for a subunit of the osteoclast proton pump. The aim of this study was to restore the resorptive function of IMO osteoclasts by lentiviral mediated gene transfer of the TCIRG1 cDNA. CD34(+) cells from peripheral blood of five IMO patients and from normal cord blood were transduced with lentiviral vectors expressing TCIRG1 and GFP under a SFFV promoter, expanded in culture and differentiated on bone slices to mature osteoclasts. qPCR analysis and western blot revealed increased mRNA and protein levels of TCIRG1, comparable to controls. Vector corrected IMO osteoclasts generated increased release of Ca(2+) and bone degradation product CTX-I into the media as well as increased formation of resorption pits in the bone slices, while non-corrected IMO osteoclasts failed to resorb bone. Resorption was approximately 70-80% of that of osteoclasts generated from cord blood. Furthermore, transduced CD34(+) cells successfully engrafted in NSG-mice. In conclusion we provide the first evidence of lentiviral-mediated correction of a human genetic disease affecting the osteoclastic lineage.
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| 6. |
- Xian, Xiaojie, et al.
(författare)
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Generation of gene-corrected functional osteoclasts from osteopetrotic induced pluripotent stem cells
- 2020
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Ingår i: Stem Cell Research & Therapy. - : Springer Science and Business Media LLC. - 1757-6512. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- Background Infantile malignant osteopetrosis (IMO) is an autosomal recessive disorder characterized by non-functional osteoclasts and a fatal outcome early in childhood. About 50% of patients have mutations in the TCIRG1 gene. Methods IMO iPSCs were generated from a patient carrying a homozygous c.11279G>A (IVS18+1) mutation in TCIRG1 and transduced with a lentiviral vector expressing human TCIRG1. Embryoid bodies were generated and differentiated into monocytes. Non-adherent cells were harvested and further differentiated into osteoclasts on bovine bone slices. Results Release of the bone resorption biomarker CTX-I into the media of gene-corrected osteoclasts was 5-fold higher than that of the uncorrected osteoclasts and 35% of that of control osteoclasts. Bone resorption potential was confirmed by the presence of pits on the bones cultured with gene-corrected osteoclasts, absent in the uncorrected IMO osteoclasts. Conclusions The disease phenotype was partially corrected in vitro, providing a valuable resource for therapy development for this form of severe osteopetrosis.
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