title: Severe Extracellular Matrix Abnormalities and Chondrodysplasia in Mice Lacking Collagen Prolyl 4-Hydroxylase Isoenzyme II in Combination with a Reduced Amount of Isoenzyme I.
abstract: Collagen prolyl 4-hydroxylases (C-P4H-I, C-P4H-II, and C-P4H-III) catalyze formation of 4-hydroxyproline residues required to form triple-helical collagen molecules. Vertebrate C-P4Hs are α2β2 tetramers differing in their catalytic α subunits. C-P4H-I is the major isoenzyme in most cells, and inactivation of its catalytic subunit (P4ha1(-/-)) leads to embryonic lethality in mouse, whereas P4ha1(+/-) mice have no abnormalities. To study the role of C-P4H-II, which predominates in chondrocytes, we generated P4ha2(-/-) mice. Surprisingly, they had no apparent phenotypic abnormalities. To assess possible functional complementarity, we established P4ha1(+/-);P4ha2(-/-) mice. They were smaller than their littermates, had moderate chondrodysplasia, and developed kyphosis. A transient inner cell death phenotype was detected in their developing growth plates. The columnar arrangement of proliferative chondrocytes was impaired, the amount of 4-hydroxyproline and the Tm of collagen II were reduced, and the extracellular matrix was softer in the growth plates of newborn P4ha1(+/-);P4ha2(-/-) mice. No signs of uncompensated ER stress were detected in the mutant growth plate chondrocytes. Some of these defects were also found in P4ha2(-/-) mice, although in a much milder form. Our data show that C-P4H-I can to a large extent compensate for the lack of C-P4H-II in proper endochondral bone development, but their combined partial and complete inactivation, respectively, leads to biomechanically impaired extracellular matrix, moderate chondrodysplasia, and kyphosis. Our mouse data suggest that inactivating mutations in human P4HA2 are not likely to lead to skeletal disorders, and a simultaneous decrease in P4HA1 function would most probably be required to generate such a disease phenotype.
authors.affiliation: From the Oulu Center for Cell-Matrix Research, Biocenter Oulu, the Faculty of Biochemistry and Molecular Medicine, and.
authors.forename: Ellinoora
authors.initials: E
authors.lastname: Aro
authors.affiliation: From the Oulu Center for Cell-Matrix Research, Biocenter Oulu, the Faculty of Biochemistry and Molecular Medicine, and.
authors.forename: Antti M
authors.initials: AM
authors.lastname: Salo
authors.affiliation: the Indiana University School of Medicine, Indianapolis, Indiana 46202.
authors.forename: Richa
authors.initials: R
authors.lastname: Khatri
authors.affiliation: Pathology, University of Oulu, FIN-90014 Oulu, Finland.
authors.forename: Mikko
authors.initials: M
authors.lastname: Finnilä
authors.affiliation: Biocenter Oulu.
authors.forename: Ilkka
authors.initials: I
authors.lastname: Miinalainen
authors.affiliation: Biocenter Oulu, Pathology, University of Oulu, FIN-90014 Oulu, Finland.
authors.forename: Raija
authors.initials: R
authors.lastname: Sormunen
authors.affiliation: From the Oulu Center for Cell-Matrix Research, Biocenter Oulu, the Faculty of Biochemistry and Molecular Medicine, and.
authors.forename: Outi
authors.initials: O
authors.lastname: Pakkanen
authors.affiliation: From the Oulu Center for Cell-Matrix Research, Biocenter Oulu, the Faculty of Biochemistry and Molecular Medicine, and.
authors.forename: Tiina
authors.initials: T
authors.lastname: Holster
authors.affiliation: From the Oulu Center for Cell-Matrix Research, Biocenter Oulu, the Faculty of Biochemistry and Molecular Medicine, and.
authors.forename: Raija
authors.initials: R
authors.lastname: Soininen
authors.affiliation: the Department of Applied Sciences and Mechatronics and the Center for Applied Tissue Engineering and Regenerative Medicine, Munich University of Applied Sciences, 80335 Munich, Germany.
authors.forename: Carina
authors.initials: C
authors.lastname: Prein
authors.affiliation: the Department of Applied Sciences and Mechatronics and the Center for Applied Tissue Engineering and Regenerative Medicine, Munich University of Applied Sciences, 80335 Munich, Germany, the Center for NanoScience, Ludwig-Maximilians University, 80539 Munich, Germany, and.
authors.forename: Hauke
authors.initials: H
authors.lastname: Clausen-Schaumann
authors.affiliation: the Center for Applied Tissue Engineering and Regenerative Medicine, Munich University of Applied Sciences, 80335 Munich, Germany, the Laboratory of Experimental Surgery and Regenerative Medicine, Department of Surgery, Clinical Center University of Munich, 80336 Munich, Germany.
authors.forename: Attila
authors.initials: A
authors.lastname: Aszódi
authors.affiliation: Pathology, University of Oulu, FIN-90014 Oulu, Finland.
authors.forename: Juha
authors.initials: J
authors.lastname: Tuukkanen
authors.affiliation: From the Oulu Center for Cell-Matrix Research, Biocenter Oulu, the Faculty of Biochemistry and Molecular Medicine, and.
authors.forename: Kari I
authors.initials: KI
authors.lastname: Kivirikko
authors.affiliation: the Indiana University School of Medicine, Indianapolis, Indiana 46202.
authors.forename: Ernestina
authors.initials: E
authors.lastname: Schipani
authors.affiliation: From the Oulu Center for Cell-Matrix Research, Biocenter Oulu, the Faculty of Biochemistry and Molecular Medicine, and johanna.myllyharju@oulu.fi.
authors.forename: Johanna
authors.initials: J
authors.lastname: Myllyharju
mesh_terms: D000818:Animals; D017209:Apoptosis; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology / Q000201:enzymology* / Q000378:metabolism; D003094:Collagen / Q000096:biosynthesis; D004195:Disease Models, Animal; D005109:Extracellular Matrix / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D010009:Osteochondrodysplasias / Q000196:embryology / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology; D011393:Procollagen-Proline Dioxygenase / Q000172:deficiency* / Q000235:genetics
chemical_list: D003094:Collagen; D011393:Procollagen-Proline Dioxygenase
keywords: collagen; extracellular matrix; gene knock-out; hydroxylase; hydroxyproline