A method is described for using the Ea4-peptide of pro-IGF-I or human Eb-peptide of pro-IGF-I for enhancing the proliferation of fibroblasts and closure of wound. The peptide species can be homologous of trout Ea4-peptide, human Eb-peptide of pro-IGF-I or a fusion protein comprising the Ea4- or Eb-peptide of pro-IGF-I. It can be administered any wound in a pharmaceutically acceptable composition alone or in combination with other compounds.