FIGURE 7.

Model of how DGAT1 deficiency modulates RA signaling in skin. LRAT is the major pathway for maintaining adequate stores of retinol, as retinyl esters, in the skin. However, the ARAT activity of DGAT1 is important for generating retinyl esters when retinol levels are excessive and preventing retinol toxicity. In DGAT1 deficiency in murine skin, excess retinol is converted to retinaldehyde and subsequently to RAs, which modulate gene expression and hair cycling. If retinol is depleted from the diet, the effects of DGAT1 deficiency are minimized.