Derangement of the epidermal barrier lipids and dysregulated immune responses are key pathogenic features of atopic dermatitis (AD). The Th2-type cytokines interleukin IL-4 and IL-13 play a prominent role in AD by activating the Janus Kinase/Signal Transduction and Activator of Transcription (JAK/STAT) intracellular signaling axis. This study aimed to investigate the role of JAK/STAT in the lipid perturbations induced by Th2 signaling in 3D epidermal equivalents. Tofacitinib, a low-molecular-mass JAK inhibitor, was used to screen for JAK/STAT-mediated deregulation of lipid metabolism. Th2 cytokines decreased the expression of elongases 1, 3, and 4 and serine-palmitoyl-transferase and increased that of sphingolipid delta(4)-desaturase and carbonic anhydrase 2. Th2 cytokines inhibited the synthesis of palmitoleic acid and caused depletion of triglycerides, in association with altered phosphatidylcholine profiles and fatty acid (FA) metabolism. Overall, the ceramide profiles were minimally affected. Except for most sphingolipids and very-long-chain FAs, the effects of Th2 on lipid pathways were reversed by co-treatment with tofacitinib. An increase in the mRNA levels of CPT1A and ACAT1, reduced by tofacitinib, suggests that Th2 cytokines promote FA beta-oxidation. In conclusion, pharmacological inhibition of JAK/STAT activation prevents the lipid disruption caused by the halted homeostasis of FA metabolism.

Background: Vitiligo is featured by the manifestation of white maculae and primarily results from inflammatory/immune-selective aggression to melanocytes. The trigger mechanism leading to the activation of resident immune cells in the skin still lacks a molecular description. There is growing evidence linking altered mitochondrial metabolism to vitiligo, suggesting that an underlying metabolic defect may enable a direct activation of the immune system. Recent evidence demonstrated the association of vitiligo with disorders related to systemic metabolism, including insulin resistance (IR) and lipid disarrangements. However, IR, defined as a cellular defect in the insulin-mediated control of glucose metabolism, and its possible role in vitiligo pathogenesis has not been proven yet. Methods: In this study, we compared the Ins/IGF-1 intracellular signaling of dermal and epidermal cells isolated from non-lesional vitiligo skin to that belonging to cells obtained from healthy donors. Results: We demonstrated that due to the intensified glucose uptake, S6, and insulin receptor substrate 1 (IRS1) chronic phosphorylation, their inducibilities were downsized, a condition that coincides with the definition of insulin resistance at the cellular level. Correspondingly, the mitogenic and metabolic activities normally provoked by Ins/IGF-1 exposure resulted in significantly compromised vitiligo cells (p ≤ 0.05). Besides all the vitiligo-derived skin cells manifesting an energetic disequilibrium consisting of a low ATP, catabolic processes activation, and chronic oxidative stress, the functional consequences of this state appear amplified in the keratinocyte lineage. Conclusion: The presented data argue for insulin and IGF-1 resistance collocating dysfunctional glucose metabolism in the mechanisms of vitiligo pathogenesis. In vitiligo keratinocytes, the intrinsic impairment of intracellular metabolic activities, particularly when associated with stimulation with Ins/IGF-1, converges into an aberrant pro-inflammatory phenotype that may initiate immune cell recruitment.

The Tumour Microenvironment (TME) is pivotal for melanoma progression and contributes to therapy resistance. While dermal cell involvement is well established, the role of epidermal cells remains less defined. To explore the contribution of Normal Human Keratinocytes (NHKs) to melanoma biology, we investigated the modification of gene and protein expression of NHKs exposed to melanoma-conditioned medium or maintained in a co-culture system. The analysis focused on pathways related to proliferation, inflammation, Extracellular Matrix (ECM) remodelling, and cell adhesion. Due to the well-documented melanoma–fibroblast crosstalk, Normal Human Fibroblasts (NHFs) and Cancer-Associated Fibroblasts (CAFs) were used as comparative references. Keratinocyte gene expression changes under the influence of melanoma secretome only partially overlapped with those of NHFs and CAFs, indicating cell-type-specific responses. Exposure to melanoma-conditioned medium induced the upregulation of bFGF, CXCL-16, TIMP-2, and E-cadherin in NHKs, alongside downregulating TGF-β and MMP-9. Although bFGF is a recognized pro-tumorigenic factor, the modulation of CXCL-16, TIMP-2, and TGF-β may reflect a protective response. Notably, under co-culture conditions, NHKs exhibited a pronounced pro-inflammatory and ECM-remodelling phenotype, characterized by elevated production of cytokines (IL-1α, IL-1β, and IL-8) and ECM-degrading enzymes (MMP-7, 9, 12, and 13), indicative of a pro-tumoral feature. Collectively, these findings underscore an active role for NHKs in melanoma initiation and progression.

Background: Brooke–Spiegler syndrome is a rare autosomal dominant disorder characterized by the continuous development of multiple benign skin appendage tumors. It is treated usually by repeated standard surgery. Here, we present a case study where electrochemotherapy (ECT) with bleomycin was used as an effective alternative approach in treating advanced dermal cylindromatosis of the head and neck in a patient with Brooke–Spiegler syndrome. Patients and methods: A 45-year-old woman presented with multiple recurrent dermal cylindroma lesions on her scalp. Previous treatment consisted of several surgical excisions that resulted in psychological deterioration due to the formation of numerous scars and extensive alopecic areas. ECT was offered to provide tumor removal and disease control and to improve the patient’s quality of life. Results: The treatment was well tolerated, and a significant reduction in neoplastic tissue was achieved. Importantly, scalp skin condition significantly improved, regaining a fair follicular density on the margins. Conclusion: This report suggests the feasibility of bleomycin ECT as a less invasive alternative option for controlling multiple scalp cylindroma lesions with cosmetically acceptable results, and improving quality of life.

Atopic dermatitis (AD) is a chronic inflammatory disorder presenting a dysregulated immune response and derangement of the epidermal barrier lipids. The Th2-type cytokines interleukin IL-4 and IL-13 play a prominent role in AD by activating the Janus Kinase/Signal Transduction and Activator of Transcription (JAK/STAT) intracellular signal axis. This study aimed to investigate the role of JAK/STAT in the lipid perturbations induced by Th2 signaling in 3D-epidermal equivalents. We used tofacitinib, a low-molecular-mass JAK inhibitor, to screen for the JAK/STAT-mediated deregulation of lipid metabolism. Th2 cytokines decreased the expression of elongases 1, 3, and 4, and serine-palmitoyl-transferase and increased that of sphingolipid delta(4)-desaturase, and carbonic anhydrase 2. Th2 cytokines inhibited the synthesis of palmitate and caused a depletion of triglycerides. This depletion was associated with altered PC profiles and fatty acid (FA) metabolism. Overall, the ceramide profiles were minimally affected. Except for most sphingolipids and very long chain FAs, the effects of Th2 on lipid pathways were reversed by co-treatment with tofacitinib. An increase in the mRNA levels of CPT1A and ACAT1, reduced by tofacitinib, suggests that Th2 cytokines promote FA beta-oxidation. In conclusion, pharmacological inhibition of JAK/STAT activation prevents the lipid disruption caused by halted homeostasis of FA metabolism.