Abstract
Purpose :
The lamina cribrosa (LC) of the optic nerve head is a key site of damage in glaucoma. A disintegrin and metalloproteinase (ADAM) 12 & 19 are members of a family of transmembrane, multidomain proteins implicated in a variety of cellular activities including proteolysis, cell adhesion, signalling and the regulation of growth factors through ectodomain shedding. Both ADAM 12 &19 have been shown to be upregulated in numerous cancers and fibrotic processes. Stimulation of renal cells with TGFb, a key mediator of fibrosis, upregulates ADAM 12/19 expression via Smad2/3 phosphorylation. MiR29b, a microRNA which is believed to play an antifibrotic role, blocks the TGFb-induced overexpression of ADAM12. Our lab has previously shown that glaucoma LC cells have elevated pro-fibrotic gene expression. Here, we investigate the expression of ADAM12 &19 in normal and glaucoma lamina cribrosa cells and examine their role in extracellular matrix gene production.
Methods :
LC cells were obtained from 2 normal and 2 glaucoma age matched human eye donors. Cells were cultured under physiological conditions. Quantitative real time reverse transcriptase Polymerase Chain Reaction (qRT-PCR) was performed to measure the expression level of ADAM 12 and 19 mRNA in normal LC cells compared to glaucoma LC cells. The relative expression of both genes of interest ADAM 12 &19 was calculated using ΔΔCt method. The ribosomal gene 18S was used as housekeeping gene.
Results :
ADAM 12 and ADAM 19 transcription levels are significantly (p<0.05) enhanced in glaucoma LC cells compared to normal LC cells. The relative transcription level of ADAM 12 increased from 0.48 ± 0.049 in NLC to 0.76 ± 0.067 in GLC, and the relative expression level of ADAM 19 increased from 0.61 ± 0.058 in NLC to 0.82 ± 0.077 in GLC. The relative expression level of genes was determined using the ΔΔCt method, with data normalized to the internal reference gene 18S.
Conclusions :
Here we have shown ADAM 12 and 19 to be significantly upregulated at the lamina cribrosa in glaucoma. We are currently investigating whether mir29b may play a role in suppressing the upregulation of ADAM 12/19 in glaucoma LC cells and therefore, may represent a potential future therapeutic target for the prevention of fibrotic transformation at the lamina cribrosa in glaucoma.
This is a 2021 ARVO Annual Meeting abstract.