Chronic social stress Ameliorates psoriasiform dermatitis through upregulation of the Hypothalamic-Pituitary-Adrenal axis.

Acute stress is a physiological response of an organism to adverse conditions, contributing to survival; however, persistence through time may lead to disease. Indeed, exacerbation of inflammatory conditions such as psoriasis has been reported to follow stressors in susceptible patients. Because chronic stress cannot ethically be elicited in patients under controlled laboratory conditions, we studied genetically modified mice that naturally develop psoriasiform dermatitis, and subjected them to an ethological chronic social contact stress paradigm.

Aldo-keto reductase 1C3 is overexpressed in skin squamous cell carcinoma (SCC) and affects SCC growth via prostaglandin metabolism.

Aldo-keto reductase 1C3 (AKR1C3) is an enzyme involved in metabolizing prostaglandins (PGs) and sex hormones. It metabolizes PGD2 to 9α11β-PGF2 , diverting the spontaneous conversion of PGD2 to the PPARγ agonist, 15-Deoxy-Delta-12, 14-prostaglandin J2 (15d-PGJ2 ). AKR1C3 is overexpressed in various malignancies, suggesting a tumor promoting function.

Effects of psychological stress and housing conditions on the delay of wound healing.

This study explores the effects of stress and housing conditions on the healing of cutaneous wounds and its relationship with circulating levels of corticosterone. Specifically, we set out to examine the effect of combined physical (restraint stress and ultrasound) and psychological (predator scent) stressors on the cutaneous wound healing of female mice that had been housed either in groups (with social support; n= 16) or individually (without social support; n= 16). In contrast with other studies, the model of multiple ethological mild stressors utilized in this study significantly increased the levels of corticosterone, but failed to dramatically alter the healing of skin wounds.

Aldo-keto reductase 1C3 is expressed in differentiated human epidermis, affects keratinocyte differentiation, and is upregulated in atopic dermatitis.

Aldo-keto reductase 1C3 (AKR1C3) has been shown to mediate the metabolism of sex hormones and prostaglandin D(2) (PGD(2)), a lipid mediator that promotes skin inflammation in atopic dermatitis (AD). As both have a role in skin function and pathology, we first sought to investigate the expression pattern of AKR1C3 in normal human epidermis. Immunofluorescence revealed a strong expression of AKR1C3 in the differentiated suprabasal layers compared with the basal layer.

Effects of continuous-wave (670-nm) red light on wound healing.

Background: Recent work suggests that injuries can heal faster if treated by lasers emitting 670-nm red light. LED lights emitting 670-nm light are now available. This suggests that inexpensive and easy-to-use 670-nm LED lights might help accelerate cutaneous wound healing.

Sequential down-regulation of E-cadherin with squamous cell carcinoma progression: loss of E-cadherin via a prostaglandin E2-EP2 dependent posttranslational mechanism.

The incidence of skin cancer is on the rise, with over 1 million new cases yearly. Although it is known that squamous cell cancers (SCC) are caused by UV light, the mechanism(s) involved remains poorly understood. In vitro studies with epithelial cells or reports examining malignant skin lesions suggest that loss of E-cadherin-mediated cell-cell contacts may contribute to SCCs.

Deletion of prostaglandin E2 EP2 receptor protects against ultraviolet-induced carcinogenesis, but increases tumor aggressiveness.

Ultraviolet (UV) light is a complete carcinogen inducing and promoting squamous-cell carcinoma (SCC) of the skin. Recent work has shown that SCC initiation and promotion are enhanced by prostaglandin E2 (PGE2). PGE2 interacts with specific EP receptors to regulate cellular functions.

The EP3 receptor stimulates ceramide and diacylglycerol release and inhibits growth of primary keratinocytes.

Primary human keratinocytes (PHKs) are known to express the EP3 subtype of prostaglandin E2 receptor. To better understand the role of EP3 receptors in regulating epidermal function, we characterized their expression, localization, and signaling effects in human skin. Three different splice variants of the EP3 receptor (EP3A1, EP3C, and EP3D) were found to be expressed.

Cyclooxygenase-1 deletion enhances apoptosis but does not protect against ultraviolet light-induced tumors.

Inhibition or deletion of cyclooxygenase (COX)-2 has been demonstrated to protect against squamous cell cancer in many studies. Although much effort has focused on COX-2 inhibition, recent work indicates that COX-1 deletion may be nearly as protective. In this study, we used SKH-1 hairless mice in which COX-1 was selectively deleted to examine the role of COX-1 in photocarcinogenesis.