1
|
Carney BC, Dougherty RD, Moffatt LT, Simbulan-Rosenthal CM, Shupp JW, Rosenthal DS. Promoter Methylation Status in Pro-opiomelanocortin Does Not Contribute to Dyspigmentation in Hypertrophic Scar. J Burn Care Res 2021; 41:339-346. [PMID: 31541238 DOI: 10.1093/jbcr/irz168] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Burn injuries frequently result in hypertrophic scars (HTSs), specifically when excision and grafting are delayed due to limited resources or patient complications. In patient populations with dark baseline pigmentation, one symptom of HTS that often occurs is dyspigmentation. The mechanism behind dyspigmentation has not been explored, and, as such, prevention and treatment strategies for this morbidity are lacking. The mechanism by which cells make pigment is controlled at the apex of the pathway by pro-opiomelanocortin (POMC), which is cleaved to its products alpha-melanocyte-stimulating hormone (α-MSH) and adrenocorticotropin hormone (ACTH). α-MSH and ACTH secreted by keratinocytes bind to melanocortin 1 receptor (MC1R), expressed on melanocytes, to initiate melanogenesis. POMC protein expression is upregulated in hyperpigmented scar compared to hypopigmented scar by an unknown mechanism in a Duroc pig model of HTS. POMC RNA levels, as well as the POMC gene promoter methylation status were investigated as a possible mechanism. DNA was isolated from biopsies obtained from distinct areas of hyper- or hypopigmented scar and normal skin. DNA was bisulfite-converted, and amplified using two sets of primers to observe methylation patterns in two different CpG islands near the POMC promoter. Amplicons were then sequenced and methylation patterns were evaluated. POMC gene expression was significantly downregulated in hypopigmented scar compared to normal skin, consistent with previously reported protein expression levels. There were significant changes in methylation of the POMC promoter; however, none that would account for the development of hyper- or hypopigmentation. Future work will focus on other areas of POMC transcriptional regulation.
Collapse
Affiliation(s)
- Bonnie C Carney
- Department of Biochemistry and Molecular and Cellular Biology, Georgetown University School of Medicine, Washington, DC.,Firefighters' Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC
| | - Ryan D Dougherty
- Department of Biochemistry and Molecular and Cellular Biology, Georgetown University School of Medicine, Washington, DC
| | - Lauren T Moffatt
- Department of Biochemistry and Molecular and Cellular Biology, Georgetown University School of Medicine, Washington, DC.,Firefighters' Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC
| | - Cynthia M Simbulan-Rosenthal
- Department of Biochemistry and Molecular and Cellular Biology, Georgetown University School of Medicine, Washington, DC
| | - Jeffrey W Shupp
- Department of Biochemistry and Molecular and Cellular Biology, Georgetown University School of Medicine, Washington, DC.,Firefighters' Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC.,The Burn Center, MedStar Washington Hospital Center, Washington, DC.,Department of Surgery, Georgetown University School of Medicine, Washington, DC
| | - Dean S Rosenthal
- Department of Biochemistry and Molecular and Cellular Biology, Georgetown University School of Medicine, Washington, DC
| |
Collapse
|