Study links PEX syndrome with altered cellular stress response

A study by researchers in Germany has reported pathobiological evidence of alterations in cytoprotective mechanisms in the anterior segment tissue of patients with pseudoexfoliation syndrome.

"The resultant enhanced sensitivity and vulnerability to cellular stress conditions may therefore be one contributing factor in the pathobiology of PEX (pseudoexfoliation) syndrome," the study authors said.

Matthias Zenkel, MD, and colleagues at the University of Erlangen-Nürnberg analyzed the mRNA and protein expression of stress-related genes in the anterior segment tissue of 10 confirmed PEX eyes, with and without glaucoma. They compared their findings with normal and glaucomatous control eyes.

Investigators found that the expression of MAPKp38, the heat shock proteins HSP40 and HSP60, and superoxide dismutase (SOD2) was increased up to threefold in eyes with PEX syndrome, according to the study.

Conversely, "a large set of cytoprotective gene products, including antioxidant defense enzymes, ubiquitin-conjugating enzymes, the DNA repair protein MLH1 and the stress-inducible transcription factor GADD153, were found to be consistently downregulated up to threefold in PEX specimens on both the mRNA and protein levels," the authors said.

The study is published in the December edition of Investigative Ophthalmology & Visual Science.