Endothelial tyrosine kinase Tie1 is required for normal Schlemm's canal development—brief report

J Du, BR Thomson, T Onay… - … , thrombosis, and vascular …, 2022 - Am Heart Assoc
J Du, BR Thomson, T Onay, SE Quaggin
Arteriosclerosis, thrombosis, and vascular biology, 2022Am Heart Assoc
Background: Schlemm's canal (SC) is a large vessel residing in the iridocorneal angle and
is required to regulate aqueous humor outflow. Normal SC structure and function is
indispensable for maintaining normal intraocular pressure, and elevated intraocular
pressure is a risk factor for development of glaucoma. Recent reports have identified a key
role of the angiopoietin-Tie2 pathway for SC development and function; however, the role of
the orphan receptor Tie1 has not been clarified. Methods: We used Tie1 knock out mice to …
Background
Schlemm’s canal (SC) is a large vessel residing in the iridocorneal angle and is required to regulate aqueous humor outflow. Normal SC structure and function is indispensable for maintaining normal intraocular pressure, and elevated intraocular pressure is a risk factor for development of glaucoma. Recent reports have identified a key role of the angiopoietin-Tie2 pathway for SC development and function; however, the role of the orphan receptor Tie1 has not been clarified.
Methods
We used Tie1 knock out mice to study the function of Tie1 in SC development and function. Real-time quantitative polymerase chain reaction and Western blot analyses were used to verify Tie1 deletion. High-resolution microscopy of mouse SC whole mount and cross sections were used to study SC morphology. Measurement of intraocular pressure in live mice was used to study the impact of Tie1 on SC function.
Results
Tie1 is highly expressed in both human and mouse SC. Tie1 knock out mice display hypomorphic SC and elevated intraocular pressure as a result of attenuated SC development.
Conclusions
Tie1 is indispensable for SC development and function, supporting it as a novel target for future SC-targeted glaucoma therapies and a candidate gene for glaucoma in humans.
Am Heart Assoc