Abstract
Purpose: :
Matrix metalloproteinases (MMPs) are family of proteinases involved in many biological functions including angiogenesis, tissue repair, and inflammation. MMPs are inhibited by their specific inhibitors, tissue inhibitors of MMPs (TIMPs). In the trabecular meshwork (TM), MMPs and TIMPs may have a role in regulating outflow facility and IOP. This study examined if the MMPs and TIMPs are expressed in the human normal TM.
Methods: :
TM tissues were isolated from healthy donor eyes for corneal transplantation. Monoclonal antibodies against MMPs (MMP–1, –2, –3, and –9) and antibodies against TIMPs (TIMP–1, –2, and –3) were used for immunohistochemical staining in paraffin tissue sections.
Results: :
Intense immunoreactivity for MMP–2, TIMP–2 and TIMP–3 was observed in human TM. Expression was stronger in the uveal and corneoscleral meshwork compared to juxtacanalicular meshwork and slight staining was also seen cells lining the Schlemm's canal. MMP–1, –3,–9, and TIMP–1 were only weakly present in human TM.
Conclusions: :
These findings demonstrate that MMPs and TIMPs are expressed in normal human TM. In the eye, these enzymes may have the important role in regulating extracellular matrix in the region of chamber angle and the physiological functions of TM and juxtacanalicular tissue.
Keywords: trabecular meshwork • anatomy • enzymes/enzyme inhibitors