advertisement
Abstract #12518 Published in IGR 7-2
Acute effects of PGF2α on MMP-2 secretion from human ciliary muscle cells: a PKC- and ERK-dependent process
Husain S; Jafri F; Crosson CEInvestigative Ophthalmology and Visual Science 2005; 46: 1706-1713
See also comment(s) by James Lindsey •
PURPOSE: Studies were designed to evaluate the cellular mechanisms associated with prostaglandin (PG)F2α -induced matrix metalloproteinase (MMP)-2 secretion from human ciliary muscle (HCM) cells. METHODS: The secretion and activity of MMP-2 was determined by Western blot analysis and zymography, using conditioned medium and HCM cells. ERK1/2 activity was measured by in-gel kinase assay and Western blot analysis with anti-phospho-ERK1/2 antibodies. RESULTS: PGF2α increased the secretion of MMP-2 in a dose-dependent manner with an EC(50) of 2.7 x 10(-8) M. The addition of 1 muM PGF2α also increased MMP-2 secretion in a time-dependent manner with maximum secretion occurring at 4 hours after administration. At 4 hours, the maximum increase in MMP-2 secretion and activity were 112% ± 32% and 88% ± 18%, respectively. The secretory action of PGF2α was inhibited by pretreatment with a protein kinase C (PKC) inhibitor, chelerythrine chloride; the FP receptor antagonist, AL-8810; and the MEK inhibitor, PD-98059. The addition of PGF2α and latanoprost acid increased ERK1/2 activity by 117% ± 12% and 75% ± 9%, respectively. The PGF2α - and latanoprost-acid-induced ERK1/2 activation was blocked by the presence of PKC inhibitors and downregulation of PKC by prolonged incubation with a phorbol ester. CONCLUSIONS: These data provide evidence that FP receptor activation leads to an increase in the secretion and activation of MMP-2 through PKC- and ERK1/2-dependent pathways. FP-agonist-induced activation of ERK1/2 was blocked by PKC inhibitors, indicating that PKC activation is required for ERK1/2 activation and MMP-2 secretion from HCM cells. In the ciliary muscle, the functional responses to ERK1/2 activation include secretion of MMP-2, supporting the hypothesis that increases in uveoscleral outflow facility induced by PG administration involves the secretion and activation of MMP-2.
Dr. S. Husain, Hewitt Laboratory of the Ola B. Williams Glaucoma Center, Department of Ophthalmology, Medical University of South Carolina, Charleston, SC 29425, USA
Classification:
2.9 Ciliary body (Part of: 2 Anatomical structures in glaucoma)
3.3 Immunohistochemistry (Part of: 3 Laboratory methods)
11.4 Prostaglandins (Part of: 11 Medical treatment)
