BMP-9 mediates fibroproliferation in fibrodysplasia ossificans progressiva through TGF-β signaling.

Fibrodysplasia ossificans progressiva (FOP) is a rare genetic disorder presenting with progressive heterotopic ossification (HO) in soft tissues. Early-stage FOP is characterized by recurrent episodes of painful tissue swelling (flare-ups), with numerous proliferation-activated mesenchymal stromal cells (MSCs) subsequently causing HO. However, the mechanisms underlying flare-up progression remain unclear.

Distinct muscle regenerative capacity of human induced pluripotent stem cell-derived mesenchymal stromal cells in Ullrich congenital muscular dystrophy model mice.

Background: Ullrich congenital muscular dystrophy (UCMD) is caused by a deficiency in type 6 collagen (COL6) due to mutations in COL6A1, COL6A2, or COL6A3. COL6 deficiency alters the extracellular matrix structure and biomechanical properties, leading to mitochondrial defects and impaired muscle regeneration. Therefore, mesenchymal stromal cells (MSCs) that secrete COL6 have attracted attention as potential therapeutic targets.

iMSC-mediated delivery of ACVR2B-Fc fusion protein reduces heterotopic ossification in a mouse model of fibrodysplasia ossificans progressiva.

Background: Fibrodysplasia ossificans progressiva (FOP) is a rare genetic disease caused by a gain-of-function mutation in ACVR1, which is a bone morphogenetic protein (BMP) type I receptor. Moreover, it causes progressive heterotopic ossification (HO) in connective tissues. Using FOP patient-derived induced pluripotent stem cells (FOP-iPSCs) and mouse models, we elucidated the underlying mechanisms of FOP pathogenesis and identified a candidate drug for FOP.

Mammalian copper chaperone Cox17p has an essential role in activation of cytochrome C oxidase and embryonic development.

Cox17p is essential for the assembly of functional cytochrome c oxidase (CCO) and for delivery of copper ions to the mitochondrion for insertion into the enzyme in yeast. Although this small protein has already been cloned or purified from humans, mice, and pigs, the function of Cox17p in the mammalian system has not yet been elucidated. In vitro biochemical data for mammalian Cox17p indicate that the copper binds to the sequence -KPCCAC-.

Characterization and identification of promoter elements in the mouse COX17 gene.

Cox17p, essential for the assembly of functional cytochrome c oxidase (CCO) in Saccharomyces cerevisiae, has been believed to deliver copper ions to the mitochondrion for insertion into the enzyme. We have recently isolated an approximately 20 kb genomic fragment of the mouse COX17. Reporter assay experiments have shown that most of the promoter activity was restricted to a 0.