title: Knock-In of the Recurrent R368X Mutation of PRKAR1A that Represses cAMP-Dependent Protein Kinase A Activation: A Model of Type 1 Acrodysostosis.
abstract: In humans, activating mutations in the PRKAR1A gene cause acrodysostosis 1 (ACRDYS1). These mutations result in a reduction in PKA activation caused by an impaired ability of cAMP to dissociate mutant PRKAR1A from catalytic PKA subunits. Two striking features of this rare developmental disease are renal resistance to PTH and chondrodysplasia resulting from the constitutive inhibition of PTHR1/Gsa/AC/cAMP/PKA signaling. We developed a knock-in of the recurrent ACRDYS1 R368X PRKAR1A mutation in the mouse. No litters were obtained from [R368X]/[+] females (thus no homozygous [R368X]/[R368X] mice). In [R368X]/[+] mice, Western blot analysis confirmed mutant allele heterozygous expression. Growth retardation, peripheral acrodysostosis (including brachydactyly affecting all digits), and facial dysostosis were shown in [R368X]/[+] mice by weight curves and skeletal measurements (μCT scan) as a function of time. [R368X]/[+] male and female mice were similarly affected. Unexpected, however, whole-mount skeletal preparations revealed a striking delay in mineralization in newborn mutant mice, accompanied by a decrease in the height of terminal hypertrophic chondrocyte layer, an increase in the height of columnar proliferative prehypertrophic chondrocyte layer, and changes in the number and spatial arrangement of proliferating cell nuclear antigen (PCNA)-positive chondrocytes. Plasma PTH and basal urinary cAMP were significantly higher in [R368X]/[+] compared to WT mice. PTH injection increased urinary cAMP similarly in [R368X]/[+] and WT mice. PRKACA expression was regulated in a tissue (kidney not bone and liver) manner. This model, the first describing the germline expression of a PRKAR1A mutation causing dominant repression of cAMP-dependent PKA, reproduced the main features of ACRDYS1 in humans. It should help decipher the specificity of the cAMP/PKA signaling pathway, crucial for numerous stimuli. In addition, our results indicate that PRKAR1A, by tempering intracellular cAMP levels, is a molecular switch at the crossroads of signaling pathways regulating chondrocyte proliferation and differentiation. © 2016 American Society for Bone and Mineral Research.
authors: INSERM U1169, University Paris Sud, Hôpital Bicêtre, Le Kremlin Bicêtre, France.
authors: Catherine
authors: C
authors: Le Stunff
authors: EA 2496 Laboratory Orofacial Pathologies, Imagery and Biotherapies, Dental School and Life imaging Platform (PIV), University Paris Descartes Sorbonne Paris Cité, Montrouge, France.
authors: Francoise
authors: F
authors: Tilotta
authors: EA 2496 Laboratory Orofacial Pathologies, Imagery and Biotherapies, Dental School and Life imaging Platform (PIV), University Paris Descartes Sorbonne Paris Cité, Montrouge, France.
authors: Jérémy
authors: J
authors: Sadoine
authors: EA 2496 Laboratory Orofacial Pathologies, Imagery and Biotherapies, Dental School and Life imaging Platform (PIV), University Paris Descartes Sorbonne Paris Cité, Montrouge, France.
authors: Dominique
authors: D
authors: Le Denmat
authors: INSERM U1169, University Paris Sud, Hôpital Bicêtre, Le Kremlin Bicêtre, France.
authors: Claire
authors: C
authors: Briet
authors: INSERM U1169, University Paris Sud, Hôpital Bicêtre, Le Kremlin Bicêtre, France.
authors: Emmanuelle
authors: E
authors: Motte
authors: INSERM U970, University Paris Descartes, Paris Centre de Recherche Cardiovasculaire (PARCC), Paris, France.
authors: Eric
authors: E
authors: Clauser
authors: INSERM U1169, University Paris Sud, Hôpital Bicêtre, Le Kremlin Bicêtre, France.
authors: Pierre
authors: P
authors: Bougnères
authors: EA 2496 Laboratory Orofacial Pathologies, Imagery and Biotherapies, Dental School and Life imaging Platform (PIV), University Paris Descartes Sorbonne Paris Cité, Montrouge, France.|Assistance Publique-Hôpitaux de Paris (AP-HP) Odontology Department Bretonneau, Louis Mourier, Hôpitaux Universitaires Paris Nord Val de Seine, Paris, France.|Centre de Référence des Maladies Rares du Métabolisme du Phosphore et du Calcium and Filière de Santé Maladies Rares OSCAR, AP-HP, Paris, France.
authors: Catherine
authors: C
authors: Chaussain
authors: INSERM U1169, University Paris Sud, Hôpital Bicêtre, Le Kremlin Bicêtre, France.|Centre de Référence des Maladies Rares du Métabolisme du Phosphore et du Calcium and Filière de Santé Maladies Rares OSCAR, AP-HP, Paris, France.|Service de Biochimie et Génétique Moléculaire, Hôpital Cochin, AP-HP, Paris, France.
authors: Caroline
authors: C
authors: Silve
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001842:Bone and Bones / Q000002:abnormalities / Q000473:pathology; D054756:Cyclic AMP-Dependent Protein Kinase RIalpha Subunit / Q000235:genetics*; D004413:Dysostoses / Q000097:blood / Q000000981:diagnostic imaging / Q000201:enzymology* / Q000235:genetics*; D004789:Enzyme Activation; D005260:Female; D055879:Gene Knock-In Techniques; D060005:Genotyping Techniques; D019426:Integrases / Q000378:metabolism; D008607:Intellectual Disability / Q000097:blood / Q000000981:diagnostic imaging / Q000201:enzymology* / Q000235:genetics*; D008297:Male; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D008954:Models, Biological; D009154:Mutation / Q000235:genetics*; D009928:Organ Specificity; D010009:Osteochondrodysplasias / Q000097:blood / Q000000981:diagnostic imaging / Q000201:enzymology* / Q000235:genetics*; D010641:Phenotype; D055114:X-Ray Microtomography
chemical_list: D054756:Cyclic AMP-Dependent Protein Kinase RIalpha Subunit; C517835:Prkar1a protein, mouse; C045073:Cre recombinase; D019426:Integrases
keywords: PTH/PTHrP; acrodysostosis; cyclicAMP; endochondral ossification; proteine kinase A