Lysyl oxidase and P-ATPase-7A expression during embryonic development in the rat

Area of Science:

• Biochemistry
• Developmental Biology
• Molecular Biology

Background:

• Lysyl oxidase (LOX) is essential for cross-linking extracellular matrix proteins like collagen and elastin.
• LOX activity is influenced by copper levels and genetic factors affecting copper transport, such as mutations in ATP7A.
• LOX may play a role in intracellular copper transport.

Purpose of the Study:

• To investigate the presence and activity of lysyl oxidase in developing rat embryos.
• To examine the temporal expression patterns of lysyl oxidase and ATP7A during embryonic development.
• To explore the relationship between embryonic copper transport and lysyl oxidase function.

Main Methods:

• Detection of functional lysyl oxidase activity using enzyme assays in rat embryos.
• Partial purification of embryonic extracts to remove enzyme inhibitors.
• Quantification of lysyl oxidase and ATP7A mRNA levels via RT-PCR.

Main Results:

• Lysyl oxidase functional activity was detectable in rat embryos by gestation day 9, requiring partial purification.
• Enzymatic activity per unit of protein or DNA remained relatively constant between gestation days 9 and 15.
• Steady-state levels of lysyl oxidase and ATP7A mRNA increased approximately fourfold from gestation day 9 to 15.
• The temporal expression pattern of ATP7A supports its role in copper delivery to lysyl oxidase.

Conclusions:

• Sufficient lysyl oxidase activity is present in early rat embryos.
• While LOX activity is stable, its mRNA and the copper transporter ATP7A mRNA increase during development.
• The coordinated increase suggests ATP7A is involved in providing copper for lysyl oxidase function during embryogenesis.