(WHS-P28) TRANSCRIPTOMIC DIFFERENCES BETWEEN ORAL AND SKIN KERATINOCYTES
Friday, May 17, 2024
7:30 AM – 5:00 PM East Coast USA Time
Background: In comparison to skin wounds, oral mucosal wounds heal more rapidly with significantly less inflammation, faster re-epithelialization, and minimal scarring. Our lab has previously shown that skin and oral excisional biopsy mucosal wounds exhibit site-specific differences in their genetic response to injury and that intrinsic keratinocyte characteristics may be one differentiating factor. The aim of this study was to investigate whether the intrinsic differences between oral and skin keratinocytes would be reflected in their transcriptome at baseline and after injury. Methods & Materials: In this study, we used two keratinocyte cell lines: 1) hTERT-immortalized gingival keratinocytes (TIGK) and 2) spontaneously immortalized skin keratinocytes (HaCaT). RNA was isolated from HaCaT and TIGK at 0-, 6-, and 24-hours post-scratch (N=3). Following DNase treatment, RNA-sequencing was performed and transcriptomic changes in response to injury were compared between HaCaT and TIGK. Genes that were significantly downregulated (p < 0.05) in HaCaT versus TIGK underwent gene ontology (GO) enrichment analysis and reactome pathway analysis. GO terms were annotated to biological processes (BP), cellular components (CC), and molecular function (MF). Additionally, HaCaT were stably transfected to overexpress Basic Leucine Zipper ATF-Like Transcription Factor 3 (BATF3-OvExp) or with an empty vector control (EV-Ctrl). Cellular migration and proliferation were assessed for BATF3-OvExp and EV-Ctrl (N=8-10). Expression of genes down-stream of BATF3 were assessed via RT-PCR (N=3-4).HaCaT migration was also assessed following pre- and post-scratch treatment with Interferon (IFN) Type I (N=10-12).
Results: Analysis of differentially expressed transcription factors found that BATF3 was significantly downregulated in HaCaT versus TIGK for all time points (p < 0.05). BATF3 overexpression significantly enhanced HaCaT migration and expression of down-stream genes (p < 0.05) but had no effect on proliferation. Comparison of transcriptomic changes in response to injury between HaCaT and TIGK also identified differences in expression of genes related to matricellular proteins and IFN signalling. Following pre- and post-scratch treatment with IFN Type I, HaCaT exhibited significant enhancement of migration (p < 0.05).
Conclusions: Our results demonstrate that HaCaT and TIGK exhibit differences in baseline behavior and transcriptomic responses to injury. Furthermore, both BATF3 overexpression in HaCaT and IFN Type I treatment enhanced cellular migration, which may be beneficial to wound healing. The results suggest that transcriptomic differences between oral and skin keratinocytes at baseline and in response to injury underlie the distinct wound healing phenotypes observed in skin and mucosal wounds.