Normalization of Hair Growth in Sparse Fur-Abnormal Skin and Hair (SPF-ASH) Mice by Introduction of the Rat Ornithine Transcarbamylase (OTC) Gene

The study introduced the rat ornithine transcarbamylase (OTC) gene into OTC-deficient spf-ash mice, resulting in significant improvements in enzyme activity and metabolic markers. Hemizygous spf-ash mice with the transgene exhibited liver OTC activity about twice that of nontransgenic counterparts and small intestinal OTC activity 6 times higher, reaching 12% and 27% of control levels, respectively. These transgenic mice displayed normal hair growth, nearly normalized urinary orotic acid excretion, and normalized serum citrulline concentration, indicating a successful correction of the OTC deficiency.

This study focused on characterizing the proteins in guinea-pig hair and hair-follicle tissue to understand protein synthesis in hair follicles. Five groups of reduced carboxymethylated proteins were identified, with group 1B proteins being unique to the follicle, likely originating from the medulla and inner-root-sheath layers. Most hair and follicle proteins shared similar properties, but quantitative differences were observed: follicle extracts had more group 2 proteins and fewer group 3 and 4 proteins compared to hair extracts. Additionally, follicle group 4 proteins had more low molecular weight proteins and fewer high molecular weight proteins than hair group 4 proteins. These differences were analyzed in the context of keratin protein synthesis, with group 1B proteins potentially being precursors to mature medulla and inner root sheath proteins.