Opposite expression of CYP51A1 and its natural antisense transcript AluCYP51A1 in adenovirus type 37 infected retinal pigmented epithelial cells

• CYP51A1 is downregulated in HAdV-37 infected retinal pigment epithelium cells.
• A HAdV-37 infection leads to overexpression of a unique Alu RNA, AluCYP51A1.
• AluCYP51A1 is embedded in the antisense orientation of the 3′-UTR of CYP51A1.
• AluCYP51A1 RNA may function as an antisense regulator of CYP51A1 mRNA expression.

Cytochrome P450 family member CYP51A1 is a key enzyme in cholesterol biosynthesis whose deregulation is implicated in numerous diseases, including retinal degeneration. Here we describe that HAdV-37 infection leads to downregulation of CYP51A1 expression and overexpression of its antisense non-coding Alu element (AluCYP51A1) in retinal pigment epithelium (RPE) cells. This change in gene expression is associated with a reversed accumulation of a positive histone mark at the CYP51A1 and AluCYP51A1 promoters. Further, transient AluCYP51A1 RNA overexpression correlates with reduced CYP51A1 mRNA accumulation. Collectively, our data suggest that AluCYP51A1 might control CYP51A1 gene expression in HAdV-37-infected RPE cells.