Gelatin nonwovens‐based epithelial morphogenesis involves a signaling axis comprising EGF‐receptor, MAP kinases ERK 1/2, and β1 integrin

Abstract

In biomaterials research, biomechanics which support tissue regeneration steadily gains of importance. Hence, we have previously shown that gelatin‐based electrospun nonwoven mats (NWMs) with a distinct modulus of elasticity (3.2 kPa) promotes epithelial morphogenesis. Since molecular mechanisms of this morphogenesis are still unknown, the present study aims at identifying molecules, involved herein. Epithelia established on the NMWs showed persistence of the activated state of the epidermal growth factor receptor (EGF‐R), phosphorylated at the src‐specific tyrosine 845 (EGF‐RT845) throughout the observation period of 10 days. To elucidate whether the observed morphogenesis mechanistically involves EGF‐R signaling, we inhibited EGF‐R, by employing the EGF‐RT845 specific inhibitor Gefitinib (IRESSA®). Gefitinib administration yielded a reduced expression of the β1 integrin subunit, a well‐known cell–matrix interaction receptor, concomitant with downregulation of p42/44 ERK1/2 MAP‐kinase activity. To elucidate whether the observed downregulation of β1 is EGF‐RT845‐dependent or emerging from ERK1/2 signaling, we exposed epithelia, grown on the NWMs, with the ERK1/2‐directed inhibitor U0126. In the absence of Gefitinib, inhibition of p42/44 MAP‐kinase activity resulted in decreased β1 integrin protein levels, thus indicating that β1 expression is dependent on ERK1/2 and not EGF‐RT845. Our results showed the first time that an EGF‐R‐β1 integrin‐signaling axis, including ERK1/2, promotes NWM‐elasticity‐based epithelial morphogenesis. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 663–677, 2019.

FAK Shutdown: Consequences on Epithelial Morphogenesis and Biomarker Expression Involving an Innovative Biomaterial for Tissue Regeneration

“…Secondly, biocompatible biomaterials offer the perspective for translation of the principles to cell-regenerative therapies in clinical and dental medicine [ 80 ]. In previous studies, we showed that an innovative nonwoven biohybrid membrane, which had a Young’s modulus of 3.2 kPa, was suitable to support gingival epithelial formation in vitro [ 32 , 38 ]. By employing this membrane, we could reproducibly generate organotypic epithelial equivalents of the human gingiva, which exhibited proper epithelial stratification and keratinocyte morphology.…”

“…In stratified epithelia, such as the epidermis and gingiva, differentiation is accompanied by morphological changes, which occur during vertical keratinocyte migration from the basal cell layer up to the uppermost cell sheet, and are reflected by a progressive cell flattening [ 32 , 38 ]. In conjunction with the morphological alterations, differentiation is coupled to the synthesis of biomolecules, among which the intermediate filament (IF) proteins keratin (K) 1 and K10 discriminate early from late stage and terminally differentiated keratinocytes [ 39 , 40 ].…”

From the Matrix to the Nucleus and Back: Mechanobiology in the Light of Health, Pathologies, and Regeneration of Oral Periodontal Tissues

“…In vitro experiments with electrospun, gelatin-based matrices with a specific elasticity of 3.2 kPa proved to promote proper gingival morphogenesis, which was independent of a co-culture with mesenchymal cells. Molecularly, this process depends on the ERK1/2-β1-integrin signaling axis, underlining the role of MT-triggering basal integrins for gingival epithelial tissue morphogenesis [342][343][344]. These promising results show that addressing MT through integrins by choosing a biocompatible material with the right stiffness is a cornerstone for tissue engineering and prospective regeneration of periodontal tissues, such as the gingiva.…”

On the Value of In Vitro Cell Systems for Mechanobiology from the Perspective of Yes-Associated Protein/Transcriptional Co-Activator with a PDZ-Binding Motif and Focal Adhesion Kinase and Their Involvement in Wound Healing, Cancer, Aging, and Senescence

“…This, in turn, is expressed as the modulation of cell functions that we can detect and are further modulated by cell behavior. To provide just a few examples, cellular behavior is determined by essential cellular functions, such as proliferation and differentiation, which, in turn, represent cornerstones of tissue homeostasis in the human body [ 1 , 2 ].…”

“…Moreover, biomechanical signals can also be transmitted when cells establish contact with neighboring cells, so mechanotransduction integrates horizontal contact structures, such as cadherin-based adherens junctions (AJs), in addition to vertically acting FAs. Both FAs and AJs contain highly ordered ultrastructural collections of molecules like integrins (e.g., integrin β1) and cadherins (e.g., E-cadherin in epithelia) [ 1 , 8 ], which, as mechanosensors and mechanotransducers, ensure that the biomechanical force emanating from the ECM or adjacent cells is perceived at the plasma membrane. Following perception, biomechanical cues are converted into biochemical signals and transported through the cytoplasm into the cell nucleus.…”