MiRNA-224-5p regulates the defective permeability barrier in sensitive skin by targeting claudin-5.

BACKGROUND: Sensitive skin is hypersensitive to various external stimuli and a defective epidermal permeability barrier is an important clinical feature of sensitive skin. Claudin-5 (CLDN5) expression levels decrease in sensitive skin. This study aimed to explore the impact of CLDN5 deficiency on the permeability barrier in sensitive skin and the regulatory role of miRNAs in CLDN5 expression. MATERIALS AND METHODS: A total of 26 patients were retrospectively enrolled, and the CLDN5 expression and permeability barrier dysfunction in vitro were assessed. Then miRNA-224-5p expression was also assessed in sensitive skin. RESULTS: Immunofluorescence and electron microscopy revealed reduced CLDN5 expression, increased miR-224-5p expression, and disrupted intercellular junctions in sensitive skin. CLDN5 knockdown was associated with lower transepithelial electrical resistance (TEER) and Lucifer yellow penetration in keratinocytes and organotypic skin models. The RNA-seq and qRT-PCR results indicated elevated miR-224-5p expression in sensitive skin; MiR-224-5p directly interacted with the 3`UTR of CLDN5, resulting in CLDN5 deficiency in the luciferase reporter assay. Finally, miR-224-5p reduced TEER in keratinocyte cultures. CONCLUSION: These results suggest that the miR-224-5p-induced reduction in CLDN5 expression leads to impaired permeability barrier function, and that miR-224-5p could be a potential therapeutic target for sensitive skin.

Role of interleukin-36γ induced by ultraviolet radiation in chronic actinic dermatitis.

BACKGROUND: Chronic actinic dermatitis (CAD) is an immune-mediated photodermatosis characterized by a high eosinophil count and total immunoglobulin E (IgE) in the peripheral blood of patients. At present, however, the reasons for their elevation remain unclear. OBJECTIVE: The current study aimed to detect changes in inflammatory cytokines in CAD and explore their role in this disease. METHODS: Enzyme-linked immunosorbent assay and Luminex assay were conducted to measure inflammatory factor levels. Immunohistochemical analysis and quantitative real-time polymerase chain reaction were performed to evaluate the expression levels of interleukin-36γ (IL-36γ), IL-8, chemokine (C-C motif) ligand 17 (CCL17), and CCL18. CCK8 kits were used to assess cell proliferation. Immunofluorescence was used to detect nuclear factor κB (NF-κB) p65 nuclear translocation. Western blot analysis was performed to detect the protein expression level of phosphorylated NF-κB (p-NF-κB) p65. Hematoxylin and eosin and Masson trichrome staining were applied to observe histological changes in a chronic photo-damaged mouse model. RESULTS: Eosinophils, total IgE, IL-36γ, IL-8, tumor necrosis factor α, CCL17, and CCL18 were elevated in CAD. Of note, IL-36γ promoted the proliferation of eosinophilic cells (EOL-1) and the production of IgE in peripheral blood mononuclear cells. IL-36γ also promoted the production of IL-8 and CCL18 in immortalized human keratinocytes (HaCaT cells), while ultraviolet radiation (UVR)-induced IL-36γ via activation of the NF-κB signaling pathway. CONCLUSIONS: IL-36γ was involved in the pathogenesis of CAD and UVR contributed to the production of IL-36γ, which may provide a novel therapeutic target for CAD.

LncRNA-WAKMAR2 regulates expression of CLDN1 to affect skin barrier through recruiting c-Fos.

BACKGROUND: Chronic actinic dermatitis (CAD) is an immune-mediated photo-allergic skin disease. In the clinic, the treatment of this disease is hampered by the lack of proper understanding of the skin barrier dysfunction mechanism. OBJECTIVE: To illuminate the mechanism of skin barrier dysfunction in CAD. METHODS: Transcriptome sequencing and protein profiling were used to detect skin barrier injury-related genes. RNA pull down, a promoter-reporter gene assay, and chromatin isolation by RNA purification-sequencing were used to elucidate the effect of WAKMAR2 in skin barrier functionality. RESULTS: Transcriptome sequencing from patient's tissues showed a significantly decreased expression of WAKMAR2. Down-regulation of WAKMAR2 destroyed the keratinocyte barrier. Moreover, WAKMAR2 can directly bind to the c-Fos protein. This novel long non-coding RNA (LncRNA)-protein complexes were targeted to the CLDN1 promotor. Overexpression of WAKMAR2 enhanced the promoter activity of CLDN1, while the addition of AP-1 inhibitor could reverse this phenomenon. Furthermore, our in vivo results suggested that expression of WAKMAR2 was required for the repair of skin damage in mice induced by ultraviolet irradiation. CONCLUSIONS: We identified a crucial LncRNA (WAKMAR2) for the protection of the skin barrier in vitro and in vivo. Mechanically, it can specifically interact with c-Fos protein for the regulation of CLDN1, a finding which could be applied for CAD treatment.

Up-regulation of hsa-miR-221-3p induced by UVB affects proliferation and apoptosis of keratinocytes via Bcl-xL/Bax pathway.

BACKGROUND: Chronic actinic dermatitis (CAD) is a photoallergic skin disease with abnormal hyperplasia. At present, the mechanism of abnormal proliferation is not clear. OBJECTIVE: To explore possible mechanism of CAD proliferative lesions. METHODS: Immunohistochemistry (IHC) assay and small RNA sequencing were carried out. Quantitative real-time PCR (qRT-PCR) analysis was performed to evaluate expression levels of hsa-miR-221-3p and FOS. The interaction between hsa-miR-221-3p and FOS was identified by dual-luciferase reporter assay. Expression of hsa-miR-221-3p also was detected by qRT-PCR after UVB irradiation. Influences of hsa-miR-221-3p and FOS on cell viability and apoptosis were assessed through a series of functional experiments and rescue experiments. Western blot analysis was used to detect protein expression of fos, Bax, Bcl-xL, and caspase-3. RESULTS: Patients with CAD had marked epidermal hyperplasia. The expression of hsa-miR-221-3p was up-regulated in CAD while FOS was significantly down-regulated. Dual-luciferase reporter assay confirmed that hsa-miR-221-3p targeted FOS 3'UTR. Hsa-miR-221-3p induced by UVB ranged from 0 to 30 mJ. Moreover, hsa-miR-221-3p overexpression or FOS knockdown promoted cell proliferation and reduced cell apoptosis. Western blot showed that hsa-miR-221-3p negatively regulated fos, which regulated Bcl-xL/Bax. Cell proliferation caused by hsa-miR-221-3p overexpression or FOS knockdown could be reversed by Bcl-xL inhibitor. CONCLUSION: Hsa-miR-221-3p induced by UVB targeted FOS 3'UTR, which played an important role in regulating proliferation and apoptosis of keratinocytes via Bcl-xL/Bax pathway; this may provide a new insight for CAD proliferative lesions.

A Serious Game System for Upper Limb Motor Function Assessment of Hemiparetic Stroke Patients.

Stroke often results in hemiparesis, impairing the patient's motor abilities and leading to upper extremity motor deficits that require long-term training and assessment. However, existing methods for assessing patients' motor function rely on clinical scales that require experienced physicians to guide patients through target tasks during the assessment process. This process is not only time-consuming and labor-intensive, but the complex assessment process is also uncomfortable for patients and has significant limitations. For this reason, we propose a serious game that automatically assesses the degree of upper limb motor impairment in stroke patients. Specifically, we divide this serious game into a preparation stage and a competition stage. In each stage, we construct motor features based on clinical a priori knowledge to reflect the ability indicators of the patient's upper limbs. These features all correlated significantly with the Fugl-Meyer Assessment for Upper Extremity (FMA-UE), which assesses motor impairment in stroke patients. In addition, we design membership functions and fuzzy rules for motor features in combination with the opinions of rehabilitation therapists to construct a hierarchical fuzzy inference system to assess the motor function of upper limbs in stroke patients. In this study, we recruited a total of 24 patients with varying degrees of stroke and 8 healthy controls to participate in the Serious Game System test. The results show that our Serious Game System was able to effectively differentiate between controls, severe, moderate, and mild hemiparesis with an average accuracy of 93.5%.