Neurotensin serum levels and skin gene expression are increased in atopic dermatitis.

BACKGROUND: Neurotensin (NT) participates in immune responses, but the mechanisms are not known. We have previously shown that NT augments the ability of corticotropin-releasing hormone (CRH) to increase mast-cell-dependent vascular permeability in rodents. We also showed that NT stimulates human mastcell release of vascular endothelial growth factor, and that CRH is increased in the serum of patients with atopic dermatitis (AD), an inflammatory skin condition involving mast cells. OBJECTIVES: To measure serum levels of NT, and lesional skin expression of NT and the main NT receptor (NTR-1) in AD, and to compare it with skin expression in chronic urticaria (CU) and urticaria pigmentosa (UP). METHODS: Serum NT was measured with a Milliplex microbead array. Skin NT and NTR-1 gene expression was determined with quantitative polymerase chain reaction. Immunohistochemistry was performed using a mouse monoclonal antibody for NT, and a rabbit polyclonal antibody for NTR-1. Mast cells were counterstained with Leder dye. RESULTS: Neurotensin is significantly elevated in the serum of patients with AD compared with healthy controls (P = 0.0001). NT gene expression is also significantly increased in lesional skin of patients with AD compared with controls (P = 0.0194). Moreover, immunohistochemistry of AD lesions shows NT > NTR-1 staining of perivascular cells, many of which are identified as mast cells after staining with Leder dye. There was no statistically significant difference in NT and NTR-1 lesional skin gene expression in patients with either CU or UP. CONCLUSIONS: These results suggest that interactions between NT and mast cells may occur and contribute to AD pathogenesis.

Serum neurotensin (NT) is increased in psoriasis and NT induces vascular endothelial growth factor release from human mast cells.

BACKGROUND: Psoriasis involves skin inflammation that often worsens with stress, but the mechanism of this effect remains obscure. We have shown that corticotropin-releasing hormone (CRH) is increased in the serum of patients with psoriasis. A peptide, neurotensin (NT), can trigger skin histamine release and augment the ability of CRH to increase skin vascular permeability. OBJECTIVES: To investigate the serum level of NT, and the expression of genes for NT and NT receptor-1 (NTR-1) in lesional and nonlesional skin of patients with psoriasis, compared with normal controls. Also, to study the effect of NT on human mast cell release of vascular endothelial growth factor (VEGF), which is increased in psoriatic skin. METHODS: Serum was obtained from patients with psoriasis (n = 56) and controls (n = 33); NT levels were measured with the Milliplex microbead assay. Biopsies were obtained from the lesional and nonlesional skin of patients with chronic plaque psoriasis (n = 40), who had not received any treatment for at least 15 days and were free of any systemic inflammatory diseases. Control skin samples were obtained from healthy subjects (n = 30). Expression of genes for NT and NTR-1 in the skin was evaluated by quantitative reverse transcriptase-polymerase chain reaction. LAD2 human mast cells were stimulated by NT (1 µmol L(-1)) for 24 h and VEGF was measured by enzyme-linked immunosorbent assay. RESULTS: Serum NT was increased in patients with psoriasis, while expression of genes for NT and NTR-1 in lesional skin was decreased compared with controls. NT induced VEGF release from mast cells and was augmented by interleukin-33. CONCLUSION: NT may play a role in psoriasis pathogenesis and its worsening by stress, at least in part through activation of skin mast cells.