Korean J Dermatol.  1998 Aug;36(4):595-601.

The Effects of Substance P on the Proliferation Capability of Cultured Human Keratinocytes

• Suh HS
• Chang SE
• Park EM
• Choi JH
• Sung KJ

Abstract

BACKGROUND: Recent evidence indicates that neurokinins released from cutaneous C-fibers can function as inflammatory mediators by activating cells of the immune system such as lymphocytes, monocytes and mast cells. Substance P (SP) induces normal human keratinocytes (KCs) to produce the cytokines, such as interleukin-1 alpha and the interleukin-1 receptor antagonist. KCs also have SP specific receptors, neurokinin-1. SP binds its specific receptors and mediates its biological effect to various cells in the skin.
OBJECTIVE
To demonstrate that SP may induce transforming growth factor-alpha and interleukin-6 production from cultured KC.
METHODS
Normal human neonatal foreskins were obtained from circumcision and the epidermal KCs were cultured in Medium 154 without serum. TGF-alpha and IL-6 mRNA expression on SP stimulated KCs were analyzed by the northern blot method with the poly-A+ RNA preparations. The amount of secreted TGF-alpha protein from cell free supernatants was measured by the enzyme-linked immunosorbent assay method. In addition the KC proliferation effect of SP was examined by the measurement of DNA synthesis using the [(3)H]thymidine incorporation assay.
RESULTS
The addition of SP to cultured KCs resulted in an increase in KC TGF-alpha mRNA expression but SP had no effect on KC IL-6 mRNA. KC TGF-alpha mRNA were increased at one hour after SP stimulation, and it slightly decreased at 3 hours but remained at an increased level compared to the control. Twenty four hours after 100 and 1000nM SP stimulation, the TGF-alpha protein level was increased in the supernatant. This result is consistent with that of northern blot analysis. Among SP fragments, S(7-11)P was active, but SP(1-7) had no effect. The [(3)H]thymidine assay showed that KC proliferation was inhibited only at 1,000 nM SP.
CONCLUSION
SP induces TGF-alpha mRNA expression and increases the protein level in cultured KCs, but reduces the KC DNA synthesis. These results suggest that SP may play some roles in the pathogenesis of skin diseases showing KC proliferation such as psoriasis.

Keyword

Keratinocyte; Substance P; Transforming growth factor alpha; Psoriasis

MeSH Terms

Blotting, Northern
Circumcision, Male
Cytokines
DNA
Enzyme-Linked Immunosorbent Assay
Female
Foreskin
Humans*
Immune System
Interleukin-1
Interleukin-1alpha
Interleukin-6
Keratinocytes*
Lymphocytes
Male
Mast Cells
Monocytes
Psoriasis
Receptors, Neurokinin-1
RNA
RNA, Messenger
Skin
Skin Diseases
Substance P*
Transforming Growth Factor alpha
Cytokines
DNA
Interleukin-1
Interleukin-1alpha
Interleukin-6
RNA
RNA, Messenger
Receptors, Neurokinin-1
Substance P
Transforming Growth Factor alpha