Bone morphogenetic protein 1 processes prolactin to a 17-kDa antiangiogenic factor

Area of Science:

• Endocrinology
• Molecular Biology
• Biochemistry

Background:

• Prolactin (PRL) and growth hormone (GH) have classical roles in growth and reproduction.
• These hormones and their fragments also influence angiogenesis, with fragments exhibiting anti-angiogenic effects.
• Bone morphogenetic protein 1 (BMP1) is implicated in extracellular matrix formation and angiogenesis.

Purpose of the Study:

• To investigate the interaction between PRL, GH, and BMP1-like metalloproteinases.
• To identify the processing mechanism of PRL and GH by BMP1.
• To characterize the biological activity of hormone fragments generated by BMP1.

Main Methods:

• Hormone cleavage assays using BMP1-like proteinases.
• Analysis of hormone cleavage sites.
• Assessment of anti-angiogenic activity of hormone fragments.
• Gene knockout studies in mouse embryo fibroblasts (MEFs) lacking BMP1-like proteinases.

Main Results:

• PRL and GH are substrates for BMP1-like metalloproteinases.
• Cleavage occurs at a single, characteristic site on both PRL and GH.
• A ~17-kDa N-terminal fragment of PRL exhibits potent anti-angiogenic activity.
• MEFs lacking BMP1-like proteinases lose the ability to process PRL and GH into ~17-kDa forms.

Conclusions:

• BMP1-like metalloproteinases process PRL and GH into anti-angiogenic fragments.
• This pathway represents a novel mechanism regulating angiogenesis.
• The findings link hormone metabolism to vascular development and disease.