title: HDAC6 deficiency or inhibition blocks FGFR3 accumulation and improves bone growth in a model of achondroplasia.
abstract: Mutations that cause increased and/or inappropriate activation of FGFR3 are responsible for a collection of short-limbed chondrodysplasias. These mutations can alter receptor trafficking and enhance receptor stability, leading to increased receptor accumulation and activity. Here, we show that wildtype and mutant activated forms of FGFR3 increase expression of the cytoplasmic deacetylase HDAC6 (Histone Deacetylase 6) and that FGFR3 accumulation is compromised in cells lacking HDAC6 or following treatment of fibroblasts or chondrocytes with small molecule inhibitors of HDAC6. The reduced accumulation of FGFR3 was linked to increased FGFR3 degradation that occurred through a lysosome-dependent mechanism. Using a mouse model of Thanatophoric Dysplasia Type II (TDII) we show that both HDAC6 deletion and treatment with the small molecule HDAC6 inhibitor tubacin reduced FGFR3 accumulation in the growth plate and improved endochondral bone growth. Defective endochondral growth in TDII is associated with reduced proliferation and poor hypertrophic differentiation and the improved bone growth was associated with increased chondrocyte proliferation and expansion of the differentiation compartment within the growth plate. These findings further define the mechanisms that control FGFR3 accumulation and contribute to skeletal pathology caused by mutations in FGFR3.
authors: Shriners Hospitals for Children Portland, Portland, OR, USA.
authors: Sara
authors: S
authors: Ota
authors: Shriners Hospitals for Children Portland, Portland, OR, USA.
authors: Zi-Qiang
authors: ZQ
authors: Zhou
authors: Shriners Hospitals for Children Portland, Portland, OR, USA.
authors: Megan P
authors: MP
authors: Romero
authors: Shriners Hospitals for Children Portland, Portland, OR, USA.
authors: Guang
authors: G
authors: Yang
authors: Shriners Hospitals for Children Portland, Portland, OR, USA pjh@shcc.org.|Department of Cell, Developmental and Cancer Biology and Knight Cancer Institute, Oregon Health and Science University, Portland, OR, USA.
authors: Peter J
authors: PJ
authors: Hurlin
mesh_terms: D000130:Achondroplasia / Q000188:drug therapy / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D000813:Anilides / Q000008:administration & dosage; D000818:Animals; D001846:Bone Development / Q000235:genetics; D002454:Cell Differentiation / Q000235:genetics; D049109:Cell Proliferation / Q000235:genetics; D019902:Chondrocytes / Q000187:drug effects / Q000473:pathology; D004195:Disease Models, Animal; D004791:Enzyme Inhibitors / Q000008:administration & dosage; D005347:Fibroblasts / Q000187:drug effects / Q000473:pathology; D000073864:Histone Deacetylase 6; D056572:Histone Deacetylase Inhibitors / Q000008:administration & dosage; D006655:Histone Deacetylases / Q000235:genetics*; D006801:Humans; D006877:Hydroxamic Acids / Q000008:administration & dosage; D051379:Mice; D009154:Mutation; D051498:Receptor, Fibroblast Growth Factor, Type 3 / Q000235:genetics / Q000378:metabolism*; D012886:Skull / Q000002:abnormalities* / Q000378:metabolism / Q000473:pathology; D013796:Thanatophoric Dysplasia / Q000235:genetics* / Q000378:metabolism / Q000473:pathology
chemical_list: D000813:Anilides; D004791:Enzyme Inhibitors; D056572:Histone Deacetylase Inhibitors; D006877:Hydroxamic Acids; C474316:tubacin; C496366:Fgfr3 protein, mouse; D051498:Receptor, Fibroblast Growth Factor, Type 3; C499033:Hdac6 protein, mouse; D000073864:Histone Deacetylase 6; D006655:Histone Deacetylases