External administration of moon jellyfish collagen solution accelerates physiological wound healing and improves delayed wound closure in diabetic model mice.

INTRODUCTION: Artificial dermis is an effective therapeutic method for full-thickness dermal defects. However, the currently available artificial dermis made of porcine or bovine type I collagen has several limitations such as incomplete epithelialization and delayed migration of fibrogenic and angiogenic cells into the graft. We previously developed a composite dermal graft containing a mixture of moon jellyfish collagen and porcine type I collagen, and reported its stimulatory effect on both the re-epithelialization of the epidermis and the migration of fibrogenic and angiogenic cells into the graft. In the present study, we examined whether the same effect was observed by administering jellyfish collagen solution externally onto an artificial dermal graft made of bovine type I collagen. METHODS: We used a 6 mm full-thickness wound defect model. Moon jellyfish collagen was prepared as a concentrated 0.5% solution and dripped externally onto a transplanted artificial dermal graft made of bovine type I collagen. Wound repair and long-term dermal tissue remodeling were compared between mice administered jellyfish collagen solution on the bovine collagen graft and those transplanted with a composite dermal graft containing the same amounts of jellyfish and bovine collagens. The stimulatory effect of jellyfish collagen solution was also evaluated using diabetic dB/dB mice. RESULTS: External administration of jellyfish collagen solution onto the bovine collagen graft significantly accelerated wound closure compared to control saline. It also decreased the number of inflammatory cells infiltrating the wound and suppressed absorption of the transplanted graft, as well as reduced subsequent scar formation. Furthermore, external administration of jellyfish collagen solution onto the bovine collagen graft improved the delayed wound healing in diabetic model mice, and this effect was superior to that of the currently used basic fibroblast growth factor. CONCLUSIONS: External administration of moon jellyfish collagen solution onto a bovine collagen graft significantly accelerated physiological wound healing and prevented excessive scar formation. It also improved wound closure in diabetic model mice, confirming its therapeutic application for intractable skin ulcers caused by impaired wound healing.

Nucleotide polymorphisms and the 5'-UTR transcriptional analysis of the bovine growth hormone secretagogue receptor 1a (GHSR1a) gene.

Growth hormone secretagogue receptor 1a (GHSR1a) mediates the different actions of its endogenous ligand, ghrelin. Ghrelin-GHSR is involved in many important functions that include growth hormone secretion and food intake. We evaluated the haplotype variety and characterized the microsatellite ((TG)(n) , 5'-UTR) and nucleotide polymorphisms of the bovine GHSR1a gene. The nucleotide sequencing of this gene (∼6 kb) revealed 47 single nucleotide polymorphisms (SNPs), four indels and the microsatellite ((GTTT)(n) , Intron 1). The 19 haplotypes were constructed from all nucleotide viability patterns and were divided into three major groups. Four SNPs (L24V, nt456(G>A), D191N and nt667(C>T)) and DelR242 in Exon 1 and a haplotype block of approximately 2.2 kb (nt667(C>T) ∼ nt2884 (A>G)) were found in Bos taurus breeds. Breed differences in allele frequencies of the two microsatellites, nt-7(C>A), L24V, and DelR242 loci were found (P < 0.005). A DelR242 was found in the Japanese Shorthorn (frequency: ∼ 0.44), Japanese Brown, five European cattle breeds, the Philippine native cattle, but none detected in the Japanese Black or the Mishima island cattle. Additionally, 5'-rapid amplification of cDNA ends and RT-PCR analyses revealed that there were two different kinds of transcripts: spliced, without a microsatellite within 5'-UTR (GHSR1a); and non-spliced, with the microsatellite (GHSR1b).