Synergistic effect with Phe-Gly-Leu-Met-NH2 of the C-terminal of substance P and insulin-like growth factor-1 on epithelial wound healing of rabbit cornea.
1. We previously reported that substance P and insulin-like growth factor-1 (IGF-1) synergistically stimulate corneal epithelial wound healing in vitro and in vivo. We wished to identify which portion of the amino acid sequence of substance P might be responsible for this synergism. 2. Corneal epithelial migration was not affected by the addition of any one of the following factors: substance P; Phe-Gly-Leu-Met-NH2 (C-terminal of substance P); Val-Gly-Leu-Met-NH2 (C-terminal of neurokinin A, neurokinin B, and kassinin); Tyr-Gly-Leu-Met-NH2 (C-terminal of physalaemin); Ile-Gly-Leu-Met-NH2 (C-terminal of eledoisin); or Gly-Leu-Met-NH2 (common C-terminal of tachykinins). 3. In the presence of IGF-1, only substance P and Phe-Gly-Leu-Met-NH2 were synergistic in stimulating corneal epithelial migration in a dose-dependent fashion. 4. The combination of Phe-Gly-Leu-Met-NH2 and IGF-1 did not affect the incorporation of [3H]-thymidine into corneal epithelial cells. 5. Treatment with Phe-Gly-Leu-Met-NH2 and IGF-1, but not with Phe-Gly-Leu-Met-NH2 or IGF-1 alone, increased attachment of corneal epithelial cells to a fibronectin matrix. 6. The levels of alpha5 and beta1 integrin were not affected by Phe-Gly-Leu-Met-NH2 or IGF-1 alone, but they were significantly increased by the combination of Phe-Gly-Leu-Met-NH2 and IGF-1. 7. Topical application of the same combination facilitated corneal epithelial wound closure in vivo. 8. These results demonstrated that Phe-Gly-Leu-Met-NH2, a sequence of 4 amino-acids of the C-terminal of substance P, is the minimum sequence necessary to produce the synergistic effects of substance P and IGF-1 on corneal epithelial wound healing.
Nakamura
M
M
Department of Ophthalmology, Yamaguchi University School of Medicine, Ube City, Japan.
Chikama
T
T
Nishida
T
T
D000287:Administration, Topical; D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects; D002465:Cell Movement / Q000187:drug effects; D004357:Drug Synergism; D019573:Epithelium, Corneal / Q000187:drug effects* / Q000473:pathology; D007334:Insulin-Like Growth Factor I / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D009842:Oligopeptides / Q000008:administration & dosage / Q000494:pharmacology*; D011680:Pupil / Q000187:drug effects; D011817:Rabbits; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013373:Substance P / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*; D013936:Thymidine / Q000378:metabolism; D014945:Wound Healing / Q000187:drug effects*
D009842:Oligopeptides; C112946:phenylalanyl-glycyl-leucyl-methioninamide; D013373:Substance P; D007334:Insulin-Like Growth Factor I; D013936:Thymidine