Epidermal lipid metabolism in psoriasis and lichen simplex

Area of Science:

• Biochemistry
• Dermatology
• Cell Biology

Background:

• Psoriasis and lichen simplex are common skin conditions characterized by abnormal keratinization.
• Lipogenesis, the process of lipid synthesis, plays a crucial role in epidermal function and barrier integrity.
• Altered lipid metabolism has been implicated in various skin disorders, but specific changes in epidermal lipogenesis in these conditions require further elucidation.

Purpose of the Study:

• To investigate and compare the rate and pattern of epidermal lipogenesis from glucose in patients with psoriasis and lichen simplex versus healthy controls.
• To analyze the distribution of newly synthesized lipids, particularly sterols, within the epidermis.
• To determine if disturbed sterol metabolism is a common feature in conditions associated with abnormal keratinization.

Main Methods:

• Quantitative measurement of epidermal lipogenesis using [14C] glucose in fifteen patients with psoriasis, three with lichen simplex, and twenty controls.
• Analysis of the percentage of isotope incorporated into different lipid classes, including free sterols and monoesters.
• Comparison of lipogenic rates and lipid profiles between lesional and non-lesional epidermis in psoriatic subjects and controls.

Main Results:

• In non-lesional psoriatic epidermis, a slight, non-significant increase in lipogenic rate was observed, correlated positively with free sterol percentage.
• Psoriatic lesions exhibited significantly higher total epidermal lipogenesis compared to matched non-lesional skin.
• Lesional epidermis showed increased labeling of free sterols and combined sterols/monoesters, with an elevated free sterol to monoester ratio, similar to findings in lichen simplex lesions.

Conclusions:

• Epidermal lipogenesis is significantly altered in psoriatic lesions, with a notable shift towards sterol synthesis.
• Disturbed sterol metabolism appears to be a common characteristic in skin conditions involving abnormal keratinization, such as psoriasis and lichen simplex.
• These findings highlight the potential role of aberrant lipid metabolism in the pathogenesis of these dermatological disorders.