Pihlajaniemi T, McKeon J, Gay S, Gay R, de Wet W J, Myers J C, Prockop D J
Collagen Research Unit, University of Oulu, Finland.
Biochem J. 1989 Jan 15;257(2):439-45. doi: 10.1042/bj2570439.
Fibroblasts from two lethal variants of osteogenesis imperfecta were shown to synthesize increased amounts of type IV procollagen. Previous studies established that one of these variants had a non-functional allele for the pro alpha 2 chain of type I procollagen, whereas the other pro alpha 2(I) allele contained a mutation leading to synthesis of shortened pro alpha 2(I) chains. In the two variants, the relative level of mRNA for pro alpha 1(IV) was 31 and 42% of the level of mRNA for pro alpha 1(I) chains. A value of less than 2% was found for a third lethal and four non-lethal variants of osteogenesis imperfecta. Immunofluorescent staining of fibroblasts from the two variants synthesizing increased amounts of type IV procollagen indicated that a homogeneous population of cells synthesized both type IV and type I procollagen. The results suggest that mutations in the type I procollagen genes that result in osteogenesis imperfecta can be associated with increased expression of the genes for type IV procollagen.
研究表明，来自成骨不全两种致死变体的成纤维细胞合成的IV型前胶原量增加。先前的研究证实，其中一种变体的I型前胶原α2链基因存在无功能等位基因，而另一种α2（I）等位基因发生突变，导致合成缩短的α2（I）链。在这两种变体中，α1（IV）前体mRNA的相对水平分别为α1（I）链前体mRNA水平的31%和42%。在成骨不全的另外一种致死变体和四种非致死变体中，该值小于2%。对合成IV型前胶原量增加的两种变体的成纤维细胞进行免疫荧光染色表明，同质细胞群体同时合成IV型和I型前胶原。结果表明，导致成骨不全的I型前胶原基因突变可能与IV型前胶原基因表达增加有关。
