Prostaglandin E2 gel improvement of psoriatic lesions

The link between autophagy and psoriasis

Autophagy is a lysosome-dependent, self-renewal mechanism that degrades and recycles cellular components in eukaryotic cells to maintain the homeostasis of the intracellular environment. Psoriasis is featured by increased inflammatory response, epidermal hyperproliferation and abnormal differentiation, infiltration of immune cells and increased expression levels of both endothelial adhesion molecules and angiogenic mediators. Evidence indicates that autophagy has important roles in many different types of cells, such as lymphocytes, keratinocytes, monocytes and mesenchymal stem cells (MSCs). This paper will review the role of autophagy in the pathogenesis of psoriasis and strategies for therapeutic modulation. Key Message Autophagy regulates the functions of cutaneous cells (MSCs, KCs, T cells and endothelial cells). Since reduced autophagy contributes in part to the pathogenesis of psoriasis, enhancement of autophagy can be an alternative approach to mitigate psoriasis.

Prostaglandins as a Topical Therapy for Erectile Dysfunction: A Comprehensive Review

INTRODUCTION

Erectile dysfunction (ED) is a substantial cause of dissatisfaction among many men. This discontentment has led to the emergence of various drug treatment options for this problem.

OBJECTIVES

Unfortunately, due to various interactions, contraindications, and side effects, systemic therapies such as phosphodiesterase-5 inhibitors (including sildenafil, tadalafil, vardenafil, avanafil, etc.) are not welcomed in many patients. These problems have led researchers to look for other ways to reduce these complications.

METHODS

This article holistically reviews the efficacy of topical prostaglandins and their role in treating ED. We sought to provide a comprehensive overview of recent findings on the current topic by using the extensive literature search to identify the latest scientific reports on the topic.

RESULTS

In this regard, topical and transdermal treatments can be suitable alternatives. In diverse studies, prostaglandins, remarkably PGE1 (also known as alprostadil), have been suggested to be an acceptable candidate for topical treatment.

CONCLUSION

Numerous formulations of PGE1 have been used to treat patients so far. Still, in general, with the evolution of classical formulation methods toward modern techniques (such as using nanocarriers and skin permeability enhancers), the probability of treatment success also increases.

Phosphodiesterase inhibitors and prostaglandin analogues in dermatology: A comprehensive review

Due to immune-mediated nature, medicines with immunomodulatory and anti-inflammatory effects can used to treat many dermatologic diseases. Phosphodiesterase and prostaglandins are involved in many inflammatory pathways that cause cutaneous disorders. Phosphodiesterase inhibitors (PDEIs) and prostaglandin analogues are currently employed to treat several dermatologic disorders. Given the few comprehensive reviews in this context, focusing on the dermatologic applications and efficacy of these medicines appears valuable. The present comprehensive review was, therefore, performed on the applications of PDEIs and prostaglandin analogues in different cutaneous disorders. All the relevant articles were selected to perform this review by searching databases such as Medline, Google Scholar, Scopus, and Web of Science. Oral PDEIs, especially apremilast, is an effective medicine in psoriasis and a number of other cutaneous disorders such as vitiligo. Topical PDEIs, including crisaborole ointment 2%, is a safe and effective treatment in atopic dermatitis. Prostaglandin analogues, especially their topical forms such as latanoprost and bimatoprost, have different applications in cutaneous disorders, including pigmentary disorders, especially vitiligo and hair repigmentation; for instance, bimatoprost is used for eyelash repigmentation. Prostaglandin analogues are also used in alopecia, including androgenetic alopecia and alopecia areata. Oral (apremilast) and topical (crisaborole) PDEIs and topical prostaglandin analogues, including latanoprost and bimatoprost, were found safe and effective in different skin diseases. In terms of efficiency and safety, these medicines compete with other medications of similar use even with higher efficacy and fewer side effects that necessitate further studies.

Defective Induction of COX-2 Expression by Psoriatic Fibroblasts Promotes Pro-inflammatory Activation of Macrophages

Fibroblasts play an important role as members of the innate immune system through the secretion of COX-2-derived inflammatory mediators such as prostaglandin E₂ (PGE₂). However, it has been described that dermal fibroblasts behave like mesenchymal stem cells reducing lymphocyte recruitment and dendritic cell activation through PGE₂ release. As the role of fibroblasts in psoriasis remains poorly characterized, in the present study we have evaluated the possible influence of PGE₂ derived from dermal fibroblasts as modulator of the immune response in psoriatic skin. Our results indicate that under inflammatory conditions, psoriatic fibroblasts showed defective induction of COX-2, which resulted in diminished production of PGE₂, in contrast to healthy fibroblasts. This phenotype correlated with deficient c-Jun N-terminal kinase (JNK) activation, in accordance with the hypothesis that alterations in members of the JNK pathway are associated with psoriasis. Furthermore, conditioned medium from psoriatic fibroblasts promoted the polarization of monocytic cells toward a pro-inflammatory profile, effect that was mimicked in healthy fibroblasts after pre-incubation with indomethacin. These results are consistent with a prominent role of dermal fibroblasts in the regulation of inflammatory response through the participation of COX-derived metabolites. This resolutive behavior seems to be defective in psoriatic fibroblasts, offering a possible explanation for the chronification of the disease and for the exacerbation triggered by nonsteroidal anti-inflammatory drugs (NSAIDS) such as indomethacin.

The peroxisome proliferator-activated receptor gamma system regulates ultraviolet B-induced prostaglandin e(2) production in human epidermal keratinocytes

Studies using PPARgamma agonists in mouse skin have suggested that peroxisome proliferator-activated receptor gamma (PPARgamma) is irrelevant to cutaneous photobiology. However, in several epithelial cell lines, ultraviolet B (UVB) has been shown to induce the nonenzymatic production of oxidized phospholipids that act as PPARgamma agonists. UVB is also a potent inducer of prostaglandin E(2) (PGE(2)) production and COX-2 expression in keratinocytes and PPARgamma is coupled to increased PGE(2) production in other cell lines. In this current study, we demonstrate that PPARgamma agonists, but not PPARalpha or PPARbeta/delta agonists, induce PGE(2) production and COX-2 expression in primary human keratinocytes (PHKs). Importantly, PPARgamma agonist-induced COX-2 expression and PGE(2) production were partially inhibited by the PPARgamma antagonist, GW9662, indicating that both PPARgamma-dependent and -independent pathways are likely involved. GW9662 also suppressed UVB and tert-butylhydroperoxide- (TBH-) induced PGE(2) production in PHKs and intact human epidermis and partially inhibited UVB-induced COX-2 expression in PHKs. These findings provide evidence that PPARgamma is relevant to cutaneous photobiology in human epidermis.

Concomitant Xeroderma pigmentosum and disseminated small plaque psoriasis: first case of an antinomic association

We present the case of an eighteen-year-old Caucasian white boy who was diagnosed with xeroderma pigmentosum type A at age 5 and who experienced over the past year disseminated small plaque psoriasis confirmed with skin punch biopsy. The psoriatic lesions were successfully treated with multipotent topical corticosteroids and systemic retinoids. To our knowledge, the association between psoriasis and xeroderma pigmentosum has not been previously reported and may be regarded as unlikely when considering the pathogenesis of both diseases.

Anti-Inflammatory Activity of Sertaconazole Nitrate Is Mediated via Activation of a p38–COX-2–PGE2 Pathway

Sertaconazole nitrate is an antifungal agent that exhibits anti-inflammatory activity; however, the mechanism for this action was unknown. We investigated the cellular mechanisms by which sertaconazole exerts its anti-inflammatory activity in keratinocytes and human peripheral blood mononuclear cells (PBMCs). Paradoxically, sertaconazole was found to activate the proinflammatory p38 mitogen-activated protein kinase. Treatment with sertaconazole also resulted in the induction of cyclooxygenase-2 (COX-2) and the subsequent release of prostaglandin E2 (PGE2). Knocking down p38 in keratinocytes using small interfering RNA resulted in an inhibition of sertaconazole-induced PGE2 release confirming that activation of p38 was required for PGE2 production. Additionally, in stimulated keratinocytes and human PBMCs, sertaconazole was found to suppress the release of cytokines. Treatment with anti-PGE2 antiserum or the COX-2 inhibitor NS398 reversed the inhibitory effects of sertaconazole on the release of proinflammatory cytokines, linking endogenous PGE2 with the anti-inflammatory effects. Finally, in an in vivo mouse model of tetradecanoyl phorbol acetate (TPA)-induced dermatitis, the sertaconazole-mediated inhibition of TPA-induced ear edema was reversed by NS398. Biochemical analysis of tissue biopsies revealed increase in PGE2 levels in sertaconazole-treated mice. Thus, activation of the p38-COX-2-PGE2 pathway by agents such as sertaconazole provides anti-inflammatory therapeutic benefits.

Prostaglandin E(2) suppresses CCL27 production through EP2 and EP3 receptors in human keratinocytes

BACKGROUND

The chemokine CCL27 attracts skin-homing T cells. CCL27 production by keratinocytes is enhanced in skin lesions from patients with atopic dermatitis or psoriasis vulgaris. It is suggested that prostaglandin E(2) (PGE(2)) regulates skin inflammation.

OBJECTIVE

We examined the in vitro effects of PGE(2) on CCL27 production in human keratinocytes.

METHODS

Keratinocytes were incubated with TNF-alpha in the presence or absence of PGE(2) . CCL27 secretion and mRNA level were analyzed by means of ELISA and RT-PCR, respectively. Nuclear factor kappaB (NF-kappaB)-dependent transcriptional activity was analyzed by using luciferase assays.

RESULTS

TNF-alpha increased CCL27 secretion and mRNA levels in parallel to NF-kappaB activity in keratinocytes. NF-kappaB p50 or p65 antisense oligonucleotides suppressed TNF-alpha-induced CCL27 production, indicating the requirement of NF-kappaB for CCL27 production. PGE(2) , EP2, or EP3 agonists reduced TNF-alpha-induced CCL27 secretion and mRNA levels in parallel to NF-kappaB activity and CCL2, CCL5, CXCL8, and CXCL10 mRNA levels. Either EP3-specific or dual EP1-EP2 antagonist partially blocked the inhibitory effects of PGE(2) on CCL27 production and NF-kappaB activity, and the addition of both completely abrogated the inhibition, whereas EP1 or EP4 antagonists were ineffective. Intracellular Ca(2+) chelator BAPTA/AM or cyclic adenosine monophosphate (cAMP)-dependent protein kinase inhibitor H-89 partially blocked the inhibitory effects of PGE(2) on CCL27 production and NF-kappaB activity, and the addition of both completely abrogated the inhibition. PGE(2) or EP3 agonist increased intracellular Ca(2+) concentrations. PGE(2) or EP2 agonist increased intracellular cAMP concentrations.

CONCLUSION

PGE(2) might suppress CCL27 production by inhibiting NF-kappaB activity through EP2-mediated cAMP and EP3-mediated Ca(2+) signals. PGE 2 might terminate T cell-mediated skin inflammation by inhibiting CCL27 production.