E Donetti1, L Cornaghi2, A Gualerzi2, F W Baruffaldi Preis3, F Prignano4. 1. Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, 20133 Milan, Italy. Electronic address: elena.donetti@unimi.it. 2. Dipartimento di Scienze Biomediche per la Salute, Università degli Studi di Milano, 20133 Milan, Italy. 3. I.R.C.C.S. Istituto Ortopedico Galeazzi, 20161 Milan, Italy. 4. Dipartimento di Chirurgia e Medicina Traslazionale, Università degli Studi di Firenze, 50125 Florence, Italy.
Abstract
BACKGROUND: Among all cytokines involved in the pathogenesis and in the progression of psoriasis, Tumor Necrosis Factor (TNF)-alpha and interleukin (IL)-17 play a pivotal role. OBJECTIVE: The aim of the present study was to mimic a psoriatic microenvironment and to investigate the early effects of TNF-alpha and IL-17 in a three-dimensional model of organotypic normal human skin. METHODS: Human skin explants were obtained from plastic aesthetic surgery of healthy young women 20-40years old (n=7). The study was approved by the Institutional Review Board and written informed consent was obtained from all subjects. Bioptic fragments were cultured at the air-liquid interface overnight in a Transwell system and further divided before adding either 50ng/ml IL-17 or 100ng/ml TNF-alpha or a combination of both cytokines. For each subject, a control sample was cultured without any cytokine. Samples were harvested 24 or 48h after cytokine incubation. At both time points and for all cytokine treatments a bioptic fragment obtained from each patient was processed. Epidermal proliferation, expressions of terminal differentiation (keratin 10, K10, and 14, K14) and of intercellular adhesion (occludin for tight junctions and E-cadherin for adherens junctions) biomarkers were investigated by indirect immunofluorescence. RESULTS: IL-17 and TNF-alpha induced an early and statistically significant inhibition of keratinocyte proliferation (more than 80% compared with their respective controls). At 24h, the combination of both cytokines did not further reduce cell proliferation. Starting from 24h of incubation, a non-continuous occludin expression in the granular layer was observed after both IL-17 and TNF-alpha exposure. Immunolabelling for E-cadherin in adherens junctions, for K10 in the suprabasal layers, and for K14 in the basal layer was similar in all experimental groups and unaffected after cytokine treatment. CONCLUSIONS: These results suggest that in this experimental model IL-17 and TNF-alpha induced an early alteration of the homeostasis of the inner proliferative layer and of the upper granular layer, as shown by cell proliferation inhibition and occludin expression.
BACKGROUND: Among all cytokines involved in the pathogenesis and in the progression of psoriasis, Tumor Necrosis Factor (TNF)-alpha and interleukin (IL)-17 play a pivotal role. OBJECTIVE: The aim of the present study was to mimic a psoriatic microenvironment and to investigate the early effects of TNF-alpha and IL-17 in a three-dimensional model of organotypic normal human skin. METHODS:Human skin explants were obtained from plastic aesthetic surgery of healthy young women 20-40years old (n=7). The study was approved by the Institutional Review Board and written informed consent was obtained from all subjects. Bioptic fragments were cultured at the air-liquid interface overnight in a Transwell system and further divided before adding either 50ng/ml IL-17 or 100ng/ml TNF-alpha or a combination of both cytokines. For each subject, a control sample was cultured without any cytokine. Samples were harvested 24 or 48h after cytokine incubation. At both time points and for all cytokine treatments a bioptic fragment obtained from each patient was processed. Epidermal proliferation, expressions of terminal differentiation (keratin 10, K10, and 14, K14) and of intercellular adhesion (occludin for tight junctions and E-cadherin for adherens junctions) biomarkers were investigated by indirect immunofluorescence. RESULTS:IL-17 and TNF-alpha induced an early and statistically significant inhibition of keratinocyte proliferation (more than 80% compared with their respective controls). At 24h, the combination of both cytokines did not further reduce cell proliferation. Starting from 24h of incubation, a non-continuous occludin expression in the granular layer was observed after both IL-17 and TNF-alpha exposure. Immunolabelling for E-cadherin in adherens junctions, for K10 in the suprabasal layers, and for K14 in the basal layer was similar in all experimental groups and unaffected after cytokine treatment. CONCLUSIONS: These results suggest that in this experimental model IL-17 and TNF-alpha induced an early alteration of the homeostasis of the inner proliferative layer and of the upper granular layer, as shown by cell proliferation inhibition and occludin expression.
Authors: Katherine E Herman; Takeshi Yoshida; Angela Hughson; Alex Grier; Steven R Gill; Lisa A Beck; Deborah J Fowell Journal: Front Immunol Date: 2022-02-21 Impact factor: 8.786