372 Protein o-glcNAcylation controls paracrine regulation of fibroblast function by keratinocytes

Keratinocytes produce various pro-inflammatory and profibrotic cytokines that regulate fibroblast function in a paracrine manner. Abnormal changes this effect lead to dysregulated fibrosis diseases such as scleroderma. Protein O-GlcNAcylation is the addition of GlcNAc moiety onto serine or threonine residues proteins. This catalyzed by O-GlcNAc transferase (OGT), removed O-GlcNAcase (OGA). protein are found chronic conditions diabetes, cancers Alzheimer’s disease. The aim study was determine role regulating cytokine secretion keratinocytes consequent impact on function. Primary mouse were treated with chemical inhibitors either OGT (OSMI-1), OGA (Thiamet-G). keratinocyte-conditioned media (K-CM) processed for secretome analysis Mass Spectrometry, transferred dermal fibroblasts culture. Both donor recipient harvested further analyses. We that: 1), inhibition significantly impaired, while enhanced, terminal differentiation keratinocytes; 2), transcriptomic analyzed RNA-Seq; 3), levels Connective Tissue Growth Factor lower, anti-inflammatory proteins Heme Oxygenase-1 higher OSMI-1-treated K-CM, revealed analysis; 4), culture OSMI-treated K-CM suppressed myofibroblast differentiation, but induced apoptosis fibroblasts. These findings show alters their production regulates activation turnover may be novel therapeutic target treating currently validating cell an vivo model skin fibrosis.