Protein tyrosine phosphatase conjugated with a novel transdermal delivery peptide, astrotactin 1-derived peptide recombinant protein tyrosine phosphatase (AP-rPTP), alleviates both atopic dermatitis-like and psoriasis-like dermatitis.

BACKGROUND: Atopic dermatitis (AD) and psoriasis are the 2 most common chronic inflammatory skin diseases. There is an unmet medical need to overcome limitations for transcutaneous drug development posed by the skin barrier. OBJECTIVE: We aimed to identify a novel transdermal delivery peptide and to develop a transcutaneously applicable immunomodulatory protein for treating AD and psoriasis. METHODS: We identified and generated reporter proteins conjugated to astrotactin 1-derived peptide (AP), a novel transdermal delivery peptide of human origin, and analyzed the intracellular delivery efficiency of these proteins in mouse and human skin cells and tissues using multiphoton confocal microscopy. We also generated a recombinant therapeutic protein, AP-recombinant protein tyrosine phosphatase (rPTP), consisting of the phosphatase domain of the T-cell protein tyrosine phosphatase conjugated to AP. The immunomodulatory function of AP-rPTP was confirmed in splenocytes on cytokine stimulation and T-cell receptor stimulation. Finally, we confirmed the in vivo efficacy of AP-rPTP transdermal delivery in patients with oxazolone-induced contact hypersensitivity, ovalbumin-induced AD-like, and imiquimod-induced psoriasis-like skin inflammation models. RESULTS: AP-conjugated reporter proteins exhibited significant intracellular transduction efficacy in keratinocytes, fibroblasts, and immune cells. In addition, transcutaneous administration of AP-dTomato resulted in significant localization into the dermis and epidermis in both mouse and human skin. AP-rPTP inhibited phosphorylated signal transducer and activator of transcription (STAT) 1, STAT3, and STAT6 in splenocytes and also regulated T-cell activation and proliferation. Transcutaneous administration of AP-rPTP through the paper-patch technique significantly ameliorated skin tissue thickening, inflammation, and cytokine expression in both AD-like and psoriasis-like dermatitis models. CONCLUSION: We identified a 9-amino-acid novel transdermal delivery peptide, AP, and demonstrated its feasibility for transcutaneous biologic drug development. Moreover, AP-rPTP is a novel immunomodulatory drug candidate for human dermatitis.

Serum clusterin level in children with atopic dermatitis.

BACKGROUND: Atopic dermatitis (AD) is a chronic inflammatory skin disease. Clusterin is a sensitive cellular biosensor of oxidative stress and has been studied as a marker to assess inflammatory diseases. The clusterin levels in AD have not been evaluated thus far. OBJECTIVE: We evaluated serum clusterin levels in children with AD and assessed the relationship between serum clusterin levels and the severity of AD. METHOD: The study enrolled a total 140 children, of whom 100 had AD (n = 100) and 40 were healthy (n = 40). The severity of AD was scored by using the SCORing Atopic Dermatitis (SCORAD). Total serum immunoglobulin E and specific immunoglobulin E levels against egg whites, cow's milk, peanuts, soybeans, wheat, and Dermatophagoides farinae were measured. Clusterin levels in serum were measured by enzyme-linked immunosorbent assay. RESULTS: The mean (interquartile range) age of the children was 5.1 years (1.3-8.4 years), and 92 (69.3%) of the children were boys. The mean (standard deviation) SCORAD index was 50.4 ± 17. The mean (standard deviation) clusterin level of children with AD was higher than that in the healthy control group children (148.13 ± 4.3 pg/mL versus 144.85 ± 5.1 pg/mL; p = 0.001). Serum clusterin levels were correlated with the SCORAD index (r = 0.327, p = 0.002). CONCLUSIONS: The serum clusterin level was higher in children with AD than in the healthy control group and increased with the severity of AD. Serum clusterin may be a candidate molecule that reflects AD and its severity.

Activated Leukocyte Cell Adhesion Molecule Modulates Th2 Immune Response in Atopic Dermatitis.

PURPOSE: Activated leukocyte cell adhesion molecule (ALCAM), a member of the immunoglobulin superfamily, is highly expressed on dendritic cells. ALCAM and its receptor CD6 are co-stimulatory molecules in the immunological synapse; their interaction is required for T cell activation. While atopic dermatitis (AD) is recognized as a T helper 2 (Th2)-mediated allergic disease, the role of ALCAM in its pathogenesis is unclear. METHODS: ALCAM levels were measured in the serum of AD patients and AD-induced murine model by ovalbumin treatment. We next investigated transepidermal water loss, clinical score, Th2-immune responses, skin barrier gene expression and T-cell activation using wild-type (WT) and ALCAM deficiency mice. An oxazolone-induced AD-like model was also established and analyzed using WT- and ALCAM-deficient mice. RESULTS: We found that serum ALCAM levels were elevated in pediatric AD patients as well as WT AD mice, whereas Th2-type cytokine production and AD symptoms were suppressed in ALCAM-deficient mice. In addition, CD4⁺ effector T-cell counts in murine skin and skin-draining lymph nodes were lower in ALCAM-deficient mice than in their WT counterparts. ALCAM deficiency was also linked to higher expression of skin barrier genes and number of lamellar bodies. CONCLUSIONS: These findings indicate that ALCAM may contribute to AD pathogenesis by meditating a Th2-dominant immune response and disrupting the barrier function of the skin.

German Cockroach Extract Induces Matrix Metalloproteinase-1 Expression, Leading to Tight Junction Disruption in Human Airway Epithelial Cells.

PURPOSE: Cockroach exposure is a pivotal cause of asthma. Tight junctions are intercellular structures required for maintenance of the barrier function of the airway epithelium, which is impaired in this disease. Matrix metalloproteinases (MMPs) digest extracellular matrix components and are involved in asthma pathogenesis: MMP1 is a collagenase with a direct influence on airway obstruction in asthmatics. This study aimed to investigate the mechanism by which German cockroach extract (GCE) induces MMP1 expression and whether MMP1 release alters cellular tight junctions in human airway epithelial cells (NCI-H292). MATERIALS AND METHODS: mRNA and protein levels were determined using real-time PCR and ELISA. Tight junction proteins were detected using immunofluorescence staining. Epithelial barrier function was measured by transepithelial electrical resistance (TEER). The binding of a transcription factor to DNA molecules was determined by electrophoretic mobility shift assay, while the levels of tight junction proteins and phosphorylation were determined using Western blotting. RESULTS: GCE was shown to increase MMP1 expression, TEER, and tight junction degradation. Both an inhibitor and small interfering RNA (siRNA) of MMP1 significantly decreased GCE-induced tight junction disruption. Furthermore, transient transfection with ETS1 and SP1 siRNA, and anti-TLR2 antibody pretreatment prevented MMP1 expression and tight junction degradation. An extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK) inhibitor also blocked MMP1 release, ETS1/SP1 DNA binding, and tight junction alteration. CONCLUSION: GCE treatment increases MMP1 expression, leading to tight junction disruption, which is transcriptionally regulated and influenced by the ERK/MAPK pathway in airway epithelial cells. These findings may contribute to developing novel therapeutic strategies for airway diseases.