Cellular and Molecular Effects of the Bruck Syndrome-Associated Mutation in the PLOD2 Gene

Bruck syndrome is a rare autosomal recessive disorder characterized by increased bone fragility and joint contractures similar to those in arthrogryposis and is known to be associated with mutations in the <i>FKBP10</i> (<i>FKBP prolyl isomerase 10</i>) and <i>PLOD2</i> (<i>Procollagen-Lysine,2-Oxoglutarate 5-Dioxygenase 2</i>) genes. These genes encode endoplasmic reticulum proteins that play an important role in the biosynthesis of type I collagen, which in turn affects the structure and strength of connective tissues and bones in the body. Mutations are associated with disturbances in both the primary collagen chain and its post-translational formation, but the mechanism by which mutations lead to Bruck syndrome phenotypes has not been determined, not only because of the small number of patients who come to the attention of researchers but also because of the lack of disease models. In our work, we investigated the cellular effects of two forms of the wild-type <i>PLOD2</i> gene, as well as the <i>PLOD2</i> gene with homozygous mutation c.1885A>G (p.Thr629Ala). The synthesized genetic constructs were transfected into HEK293 cell line and human skin fibroblasts (DF2 line). The localization of PLOD2 protein in cells and the effects caused by the expression of different isoforms-long, short, and long with mutation-were analyzed. In addition, the results of the transcriptome analysis of a patient with Bruck syndrome, in whom this mutation was detected, are presented.