Hypertrophic scar (HTS) occurs frequently after burn injury. Treatments for some aspects of scar morbidity exist, however, dyspigmentation treatments are lacking due to limited knowledge about why scars display dyschromic phenotypes. Full thickness wounds were created on duroc pigs that healed to form dyschromic HTS. HTS biopsies and primary cell cultures were then used to study pigmentation signaling. Biopsies of areas of both pigment types were taken for analysis. At the end of the experiment, melanocyte-keratinocyte co-cultures were established from areas of differential pigmentation. Heterogeneously dyspigmented scars formed with regions of hyperpigmentation and hypopigmentation. Melanocytes were present in both pigment types measured by S100β qRT-PCR and immunostaining, and visualized by dendritic cell presence in primary cultures. P53 expression was not different between the two pigment types. Hyperpigmented scars had up regulated levels of POMC, ACTH, α-MSH, SCF, and c-KIT and MC1R receptors compared to hypopigmented regions. Many genes involved in dyspigmentation were differentially regulated by microarray analysis including MITF, TYR, TYRP1, and DCT. MiTF expression was not different upon further exploration, but TYR, TYRP1, and DCT were up regulated in intact biopsies measured by qRT-PCR and confirmed by immunostaining. This is the first work to confirm the presence of melanocytes in hypopigmented scar using qRT-PCR and primary cell culture. An understanding of the initial steps in dyspigmentation signaling, as well as the downstream effects of these signals, will inform treatment options for patients with scars and provide insight to where pharmacotherapy may be directed.
BackgroundA functional coagulation assay was used to investigate the extrinsic pathway of coagulation on citrated whole blood samples from healthy adult male Sprague Dawley rats using the mini cup and pin system.MethodsReference values for coagulation parameters from forty-three animals were calculated using data obtained from the ROTEM® delta hemostasis analyzer with the EXTEM test.ResultsThe following ranges, presented as the 2.5–97.5 percentiles, were established: CT [18–77], CFT [20–80], α [73–86], MCF [53–70], and ML [1–22], along with others.ConclusionsThese reference ranges can be used in future studies in rats to identify clinically significant coagulopathies.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.