Psoriatic keratinocytes are resistant to tumor necrosis factor alpha's induction of mRNA for the NMDA-R2C subunit

The hair follicle-psoriasis axis: Shared regulatory mechanisms and therapeutic targets

It has long been known that there is a special affinity of psoriasis for the scalp: Here, it occurs most frequently, lesions terminate sharply in frontal skin beyond the hair line and are difficult to treat. Yet, surprisingly, scalp psoriasis only rarely causes alopecia, even though the pilosebaceous unit clearly is affected. Here, we systematically explore the peculiar, insufficiently investigated connection between psoriasis and growing (anagen) terminal scalp hair follicles (HFs), with emphasis on shared regulatory mechanism and therapeutic targets. Interestingly, several drugs and stressors that can trigger/aggravate psoriasis can inhibit hair growth (e.g. beta-blockers, chloroquine, carbamazepine, interferon-alpha, perceived stress). Instead, several anti-psoriatic agents can stimulate hair growth (e.g. cyclosporine, glucocorticoids, dithranol, UV irradiation), while skin/HF trauma (Köbner phenomenon/depilation) favours the development of psoriatic lesions and induces anagen in "quiescent" (telogen) HFs. On this basis, we propose two interconnected working models: (a) the existence of a bidirectional "hair follicle-psoriasis axis," along which keratinocytes of anagen scalp HFs secrete signals that favour the development and maintenance of psoriatic scalp lesions and respond to signals from these lesions, and (b) that anagen induction and psoriatic lesions share molecular "switch-on" mechanisms, which invite pharmacological targeting, once identified. Therefore, we advocate a novel, cross-fertilizing and integrative approach to psoriasis and hair research that systematically characterizes the "HF-psoriasis axis," focused on identification and therapeutic targeting of selected, shared signalling pathways in the future management of both, psoriasis and hair growth disorders.

Koebner phenomenon leading to the formation of new psoriatic lesions: evidences and mechanisms

Koebner phenomenon refers to the emergence of new psoriatic lesions in the healthy skin regions following an injury/trauma to psoriatic patients. The occurrence of psoriatic lesions at unusual areas of the body regions such as on penis, around eyes and on keloids suggest that the Koebner phenomenon may be responsible for these lesions. A number of agents/triggers have been reported to induce the development of new psoriatic lesions in healthy skin areas and these include, tattooing skin, radiations, skin incision, viral infections and striae etc. The different mechanisms that contribute in inducing the development of new psoriatic lesions as Koebernization include the involvement of mast cell-derived inflammatory mediators such as tryptase, IL-6, IL-8, IL-17, and IL-36γ. Moreover, an increased expression of nerve growth factor (NGF) and vascular endothelial growth factor (VEGF) also contribute in Koebernization. Apart from these, there is a critical role of α 2 β1 integrins, S100A7 (psoriasin) and S100A15 (koebnerisin), change in the ratio of CD4+/CD8+ T cells, down-regulation of mechanosensitive polycystin 1 protein, decrease in inflammation controlling atypical chemokine receptor 2 (ACKR2), reduced expression of N-methyl-d-aspartate (NMDA) receptors (NMDARs) on the keratinocytes and increase in levels of chemokines (CXCL8 and CCL20) in inducing formation of new psoriatic lesions. The present review discusses the role of Koebner phenomenon in the development of new psoriatic lesions. Moreover, it also describes the mechanisms involved in Koebernization in the form of discussion of different key targets that may be potentially modulated pharmacologically to attenuate/halt the development of new psoriatic lesions.

Anti-inflammatory and cell proliferative effect of the 1270 nm laser irradiation on the BALB/c nude mouse model involves activation of the cell antioxidant system

Recently, many interdisciplinary community researchers have focused their efforts on study of the low-level light irradiation effects (photobiomodulation, PBM) as a promising therapeutic technology. Among the priorities, a search of new wavelength ranges of laser radiation to enhance the laser prospects in treatment of autoimmune and cancer diseases commonly accompanied by disorders in the antioxidant system of the body. The laser wavelengths within 1265-1270 nm corresponds to the maximum oxygen absorption band. Therefore, PBM effects on a model organism within this spectrum range are of particular interest for preclinical research. Here, we report comprehensive biomolecular studies of the changes in the BALB/c nude mice skin after an exposure to the continuous laser radiation at the 1270 nm wavelength and energy densities of 0.12 and 1.2 J/cm2. Such regime induces both local and systemic PBM effects, presumably due to the short-term increase in ROS levels, which in turn activate the cell antioxidative system.

[The influence of laser radiation of the infrared range with a wavelength of 1270 nm on mice Balb/cNude]

BACKGROUND

The effects of low-intensity laser radiation (LILR) on the skin depend on the wavelength and density of the irradiation flux. Moreover, the vast receptor field of the skin facilitates the systemic influence of irradiation on the body.

AIMS

The objective of the present study was to evaluate the effects of low-intensity laser irradiation (LIRI) of the infrared range with a wavelength of 1270 nm on the skin of mice Balb/cNude.

MATERIAL AND METHODS

The study was carried out with the use of the linear immunodeficient mice Balb/c nude obtained from the animal house of the Pushchino branch of the Academicians M.M. Shemyakin and Yu.A. Ovchinnikov Institute of Biorganic Chemistry. The animals were irradiated once with a fiber laser of stimulated Raman scattering with a wavelength (λ) of 1270 nm, a power of 1.96 mW during the 2 min exposure at an intensity of 10 mW/cm², and an energy flux density of 1.2 J/cm². The histological studies and morphometry of the skin autoptate were performed. In adition, the expression of microRNA-21, -31, -130a, -191, -200c, -205, -218 was determined in the skin. Reverse transcription and real-time PCR reactions with Taq-Man probes and primers were performed on the nucleic acid amplifier CFX96 ('BioRad', USA).MicroRNA-191 was chosen as the reference gene. The bioinformation analysis of signaling pathways involving the studied microRNAs was performed using the DJANA miRPath database v.3.0.

RESULTS

A significant increase in the amount of keratinocytes of the basal layer was documented together with diffuse lymphoid-leukocyte infiltration of the interlobular connective tissue of the subcutaneous fat and endomysium after LILR. The pattern of microRNA expression was tissue-specific. An increase in the expression of micro-RNA-31 and-21 in the skin and a multidirectional change in miRNA-200 and -218 levels were shown. The bioinformation analysis showed that miR21 and miR31 were involved in the regulation of such signaling pathways as PI3K-Akt, Jak-STAT, MAPK, and mTOR of importance for carcinogenesis. Also, they have a signaling significance in the development of melanoma, kidney cancer, prostate cancer and malignant glioma.

CONCLUSION

The data obtained in this study suggest activation of the tumor cell-specific and basic processes in the skin of immunodeficient Balb/cNude mice under the influence of low-intensity laser radiation with a wavelength of 1270 nm applied at a dose of 1.2 J/m².