Desquamated Epithelial Cells of Unstimulated Human Whole Saliva Express Both EGF Transcript and Protein

Objective. The aim of this study was to investigate if desquamated oral epithelial cells (DOECs) express the epidermal growth factor (EGF) and if these cells thereby may contribute to salivary EGF contents. Background. DOECs have recently been shown to harbor the antimicrobial peptide LL-37, proposi...

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Main Authors: Alexandra Aidoukovitch, Sara Bodahl, Ellen Tufvesson, Bengt-Olof Nilsson
Format: Article
Language:English
Published: Hindawi Limited 2022-01-01
Series:International Journal of Dentistry
Online Access:http://dx.doi.org/10.1155/2022/3194703
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author Alexandra Aidoukovitch
Sara Bodahl
Ellen Tufvesson
Bengt-Olof Nilsson
author_facet Alexandra Aidoukovitch
Sara Bodahl
Ellen Tufvesson
Bengt-Olof Nilsson
author_sort Alexandra Aidoukovitch
collection DOAJ
description Objective. The aim of this study was to investigate if desquamated oral epithelial cells (DOECs) express the epidermal growth factor (EGF) and if these cells thereby may contribute to salivary EGF contents. Background. DOECs have recently been shown to harbor the antimicrobial peptide LL-37, proposing that they may also store other biologically important salivary peptides/proteins. The EGF peptide is a growth factor which plays a critical role to maintain epithelial integrity and promote epithelial healing. The EGF is produced by salivary glands, but it is not known whether DOECs contain the EGF and thereby contribute to salivary EGF levels. Materials and Methods. DOECs were isolated from unstimulated whole saliva collected from four healthy volunteers. EGF protein expression was determined in cell lysates by dot blot and ELISA. Cellular distribution of cytokeratin, the proliferation marker Ki67, and EGF immunoreactivity were assessed by immunocytochemistry. EGF gene expression was investigated by qPCR. Expression of EGF transcript and protein in DOECs was compared to that in the human cultured keratinocyte cell line (HaCaT) cells. Results. EGF protein expression was detected in DOEC cell lysates by both dot blot and ELISA. Strong cytoplasmic EGF immunoreactivity was observed in DOECs, although some cells showed only a weak immunoreactive signal for EGF. Moreover, DOECs, besides containing EGF protein, also expressed transcript for EGF. Interestingly, ELISA analysis revealed that EGF protein contents were higher in DOECs than in HaCaT cells. ELISA analysis also disclosed that EGF concentration was about 10 times higher in whole saliva compared to DOECs. EGF transcript expression was about 50% lower in HaCaT cells stimulated with high (10%) compared to low (0.1%) concentration of fetal bovine serum, representing growth-stimulated and growth-restricted conditions, respectively, implying that growth-stimulus exerts negative feedback on EGF gene activity in HaCaT cells. Conclusion. Here, we show for the first time that DOECs express the EGF, arguing that these cells contribute to salivary EGF contents and hence may play a role in gingival epithelial repair and wound healing.
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spelling doaj.art-d229a6febb4e4ccbb15aca34c817db4b2024-10-03T05:22:30ZengHindawi LimitedInternational Journal of Dentistry1687-87362022-01-01202210.1155/2022/3194703Desquamated Epithelial Cells of Unstimulated Human Whole Saliva Express Both EGF Transcript and ProteinAlexandra Aidoukovitch0Sara Bodahl1Ellen Tufvesson2Bengt-Olof Nilsson3Department of Experimental Medical ScienceDepartment of Experimental Medical ScienceDepartment of Clinical Sciences LundDepartment of Experimental Medical ScienceObjective. The aim of this study was to investigate if desquamated oral epithelial cells (DOECs) express the epidermal growth factor (EGF) and if these cells thereby may contribute to salivary EGF contents. Background. DOECs have recently been shown to harbor the antimicrobial peptide LL-37, proposing that they may also store other biologically important salivary peptides/proteins. The EGF peptide is a growth factor which plays a critical role to maintain epithelial integrity and promote epithelial healing. The EGF is produced by salivary glands, but it is not known whether DOECs contain the EGF and thereby contribute to salivary EGF levels. Materials and Methods. DOECs were isolated from unstimulated whole saliva collected from four healthy volunteers. EGF protein expression was determined in cell lysates by dot blot and ELISA. Cellular distribution of cytokeratin, the proliferation marker Ki67, and EGF immunoreactivity were assessed by immunocytochemistry. EGF gene expression was investigated by qPCR. Expression of EGF transcript and protein in DOECs was compared to that in the human cultured keratinocyte cell line (HaCaT) cells. Results. EGF protein expression was detected in DOEC cell lysates by both dot blot and ELISA. Strong cytoplasmic EGF immunoreactivity was observed in DOECs, although some cells showed only a weak immunoreactive signal for EGF. Moreover, DOECs, besides containing EGF protein, also expressed transcript for EGF. Interestingly, ELISA analysis revealed that EGF protein contents were higher in DOECs than in HaCaT cells. ELISA analysis also disclosed that EGF concentration was about 10 times higher in whole saliva compared to DOECs. EGF transcript expression was about 50% lower in HaCaT cells stimulated with high (10%) compared to low (0.1%) concentration of fetal bovine serum, representing growth-stimulated and growth-restricted conditions, respectively, implying that growth-stimulus exerts negative feedback on EGF gene activity in HaCaT cells. Conclusion. Here, we show for the first time that DOECs express the EGF, arguing that these cells contribute to salivary EGF contents and hence may play a role in gingival epithelial repair and wound healing.http://dx.doi.org/10.1155/2022/3194703
spellingShingle Alexandra Aidoukovitch
Sara Bodahl
Ellen Tufvesson
Bengt-Olof Nilsson
Desquamated Epithelial Cells of Unstimulated Human Whole Saliva Express Both EGF Transcript and Protein
International Journal of Dentistry
title Desquamated Epithelial Cells of Unstimulated Human Whole Saliva Express Both EGF Transcript and Protein
title_full Desquamated Epithelial Cells of Unstimulated Human Whole Saliva Express Both EGF Transcript and Protein
title_fullStr Desquamated Epithelial Cells of Unstimulated Human Whole Saliva Express Both EGF Transcript and Protein
title_full_unstemmed Desquamated Epithelial Cells of Unstimulated Human Whole Saliva Express Both EGF Transcript and Protein
title_short Desquamated Epithelial Cells of Unstimulated Human Whole Saliva Express Both EGF Transcript and Protein
title_sort desquamated epithelial cells of unstimulated human whole saliva express both egf transcript and protein
url http://dx.doi.org/10.1155/2022/3194703
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