Hypopigmented burn hypertrophic scar contains melanocytes that can be signaled to re-pigment by synthetic alpha-melanocyte stimulating hormone in vitro

• Published in: PloS one Vol. 16; no. 3; p. e0248985
• Main Authors: Carney, Bonnie C, Travis, Taryn E, Moffatt, Lauren T, Johnson, Laura S, McLawhorn, Melissa M, Simbulan-Rosenthal, Cynthia M, Rosenthal, Dean S, Shupp, Jeffrey W
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 25-03-2021; Public Library of Science (PLoS)
• Subjects: Animal models; Biochemistry; Biology; Biology and Life Sciences; Biopsy; c-Kit protein; Cellular biology; Colony-stimulating factor; Data analysis; Deoxyribonucleic acid; DNA; DNA damage; Editing; Endothelin ETB receptors; Eutrophication; Fibroblast growth factor 1; Fibroblast growth factor receptor 1; Firefighters; Funding; Gene expression; Genes; Granulocyte-macrophage colony stimulating factor; Growth factors; Health care facilities; Hospitals; Keratinocytes; Kinases; Laboratories; Leukocytes (granulocytic); Macrophages; Medical research; Medicine; Medicine and Health Sciences; Melanin; Melanocytes; Methodology; Nerve growth factor receptors; p53 Protein; Patients; Phenotypes; Physical Sciences; Pigmentation; Pigments; Proopiomelanocortin; Prostaglandin E2; Proteins; Receptors; Research and analysis methods; Reviews; Scars; Signal transduction; Skin; Staining; Stem cell factor; Stem cells; Stimulators; Surgery; Swine; Transcription factors; Ultraviolet radiation; United States > US
• DOI: 10.1371/journal.pone.0248985
• EISSN: 1932-6203

There are limited treatments for dyschromia in burn hypertrophic scars (HTSs). Initial work in Duroc pig models showed that regions of scar that are light or dark have equal numbers of melanocytes. This study aims to confirm melanocyte presence in regions of hypo- and hyper-pigmentation in an animal model and patient samples. In a Duroc pig model, melanocyte presence was confirmed using en face staining. Patients with dyschromic HTSs had demographic, injury details, and melanin indices collected. Punch biopsies were taken of regions of hyper-, hypo-, or normally pigmented scar and skin. Biopsies were processed to obtain epidermal sheets (ESs). A subset of ESs were en face stained with melanocyte marker, S100β. Melanocytes were isolated from a different subset. Melanocytes were treated with NDP α-MSH, a pigmentation stimulator. mRNA was isolated from cells, and was used to evaluate gene expression of melanin-synthetic genes. In patient and pig scars, regions of hyper-, hypo-, and normal pigmentation had significantly different melanin indices. S100β en face staining showed that regions of hyper- and hypo-pigmentation contained the same number of melanocytes, but these cells had different dendricity/activity. Treatment of hypo-pigmented melanocytes with NDP α-MSH produced melanin by microscopy. Melanin-synthetic genes were upregulated in treated cells over controls. While traditionally it may be thought that hypopigmented regions of burn HTS display this phenotype because of the absence of pigment-producing cells, these data show that inactive melanocytes are present in these scar regions. By treating with a pigment stimulator, cells can be induced to re-pigment.