Transcription Profiling of NOD-like Receptors in the Human Cornea with Disease

<i>Purpose</i>: To investigate the expression of nucleotide-binding oligomerization domain-like receptors (NLRs) in human corneas with disease and corneal cells. <i>Methods</i>: The expression of NOD1, NOD2, NLRP1, and NLRP3 was analyzed using real-time RT-PCR in (1) corneas with active infection, history of herpetic stromal keratitis (HSK), chronic allograft rejection, and limbal stem cell deficiency (LSCD), and (2) human corneal cells after lipopolysaccharide (LPS) stimulation. Healthy corneas and cells without LPS served as controls. <i>Results</i>: The mRNA levels of <i>NOD2</i> and <i>NLRP3</i> were increased in corneas with infection and HSK. Conversely, the levels of <i>NOD1, NOD2, NLRP1</i>, and <i>NLRP3</i> transcripts were decreased in corneas with LSCD. In corneas with rejection, the expression of <i>NOD1</i> and <i>NLRP1</i> was downregulated. Corneal endothelial cells upregulated the expression of <i>NOD2</i> and <i>NLRP3</i> upon LPS. <i>Conclusions</i>: The changes in the NLR expression may reflect different susceptibility to infectious and non-infectious injuries in corneas with various diseases.