Changes in matrix metalloproteinase network in a spontaneous autoimmune uveitis model

Area of Science:

• Ophthalmology
• Immunology
• Biochemistry

Background:

• Autoimmune uveitis is a serious eye condition where T cells breach the blood-retinal barrier.
• The molecular mechanisms behind the loss of immune privilege in the eye during autoimmune disease are not fully understood.

Purpose of the Study:

• To investigate alterations in the matrix metalloproteinase (MMP) network within the context of spontaneous autoimmune uveitis.
• To understand the molecular changes contributing to the loss of immune privilege in the eye.

Main Methods:

• Analyzed expression of MMP2, MMP9, MMP14, tissue inhibitor of metalloproteinase-2 (TIMP2), and lipocalin 2 (LCN2) using Western blot and zymography.
• Utilized immunohistochemistry to visualize expression patterns in a spontaneous recurrent uveitis model (equine recurrent uveitis, ERU).

Main Results:

• Decreased TIMP2 protein expression and activity were observed in the vitreous and retina of ERU models.
• Altered expression and activity of MMP2, MMP9, and MMP14 were noted, with increased MMP9 and decreased MMP2 in ERU vitreous.
• Lipocalin 2 (LCN2) showed altered expression patterns, with significant upregulation in autoimmune conditions, and was expressed by invading cells.

Conclusions:

• A dysregulation within the TIMP2-associated protein network, including altered functional protein-protein interactions, is implicated in autoimmune uveitis.
• Changes in the expression and activity of functionally related MMPs contribute to the pathology of this sight-threatening disease.