FGF Expression Allows Nevus Cells to Survive in Three-Dimensional Collagen Gel Under Conditions that Induce Apoptosis in Normal Human Melanocytes

Minocycline is a drug which induces skin hyperpigmentation. Its frequency reaches up to 50% of treated patients. The adverse effect diminishes the great therapeutic potential of minocycline, including antibacterial, neuroprotective, anti-inflammatory and anti-cancer actions. It is supposed that an elevated melanin level and drug accumulation in melanin-containing cells are related to skin hyperpigmentation. This study aimed to evaluate molecular and biochemical mechanism of minocycline-induced hyperpigmentation in human normal melanocytes, as well as the contribution of UV radiation to this side effect. The experiments involved the evaluation of cyto- and phototoxic potential of the drug using cell imaging with light and confocal microscopes as well as biochemical and molecular analysis of melanogenesis. We showed that minocycline induced melanin synthesis in epidermal melanocytes. The action was intensified by UV irradiation, especially with the UVB spectrum. Minocycline stimulated the expression of microphthalmia-associated transcription factor (MITF) and tyrosinase (TYR) gene. Higher levels of melanin and increased activity of tyrosinase were also observed in treated cells. Moreover, minocycline triggered the supranuclear accumulation of tyrosinase, similar to UV radiation. The decreased level of premelanosome protein PMEL17 observed in all minocycline-treated cultures suggests disorder of the formation, maturation or distribution of melanosomes. The study revealed that minocycline itself was able to enhance melanin synthesis. The action was intensified by irradiation, especially with the UVB spectrum. Demonstrated results confirmed the potential role of melanin and UV radiation minocycline-induced skin hyperpigmentation.

Download Full-text

Targeting hepatocyte growth factor in epithelial–stromal interactions in an in vitro experimental model of human periodontitis

Odontology ◽

10.1007/s10266-021-00625-0 ◽

2021 ◽

Author(s):

Yoko Yamaguchi ◽

Akira Saito ◽

Masafumi Horie ◽

Akira Aoki ◽

Patrick Micke ◽

...

Keyword(s):

Growth Factor ◽

Hepatocyte Growth Factor ◽

Experimental Studies ◽

Three Dimensional ◽

Collagen Gel ◽

Neutralizing Antibody ◽

Chronic Inflammatory Disease ◽

Collagen Degradation ◽

Hepatocyte Growth

AbstractPeriodontitis is a chronic inflammatory disease leading to progressive connective tissue degradation and loss of the tooth-supporting bone. Clinical and experimental studies suggest that hepatocyte growth factor (HGF) is involved in the dysregulated fibroblast–epithelial cell interactions in periodontitis. The aim of this study was to explore effects of HGF to impact fibroblast-induced collagen degradation. A patient-derived experimental cell culture model of periodontitis was applied. Primary human epithelial cells and fibroblasts isolated from periodontitis-affected gingiva were co-cultured in a three-dimensional collagen gel. The effects of HGF neutralizing antibody on collagen gel degradation were tested and transcriptome analyses were performed. HGF neutralizing antibody attenuated collagen degradation and elicited expression changes of genes related to extracellular matrix (ECM) and cell adhesion, indicating that HGF signaling inhibition leads to extensive impact on cell–cell and cell–ECM interactions. Our study highlights a potential role of HGF in periodontitis. Antagonizing HGF signaling by a neutralizing antibody may represent a novel approach for periodontitis treatment.

Download Full-text

Extending In-Plane Impedance Measurements from 2D to 3D Cultures: Design Considerations

Bioengineering ◽

10.3390/bioengineering8010011 ◽

2021 ◽

Vol 8 (1) ◽

pp. 11

Author(s):

Sorel E. De Leon ◽

Lana Cleuren ◽

Zay Yar Oo ◽

Paul R. Stoddart ◽

Sally L. McArthur

Keyword(s):

Three Dimensional ◽

3D Culture ◽

Collagen Gel ◽

Impedance Measurement ◽

Impedance Spectrum ◽

3D Models ◽

Low Frequencies ◽

3D Cell Cultures ◽

3D Collagen ◽

2D And 3D

Three-dimensional (3D) cell cultures have recently emerged as tools for biologically modelling the human body. As 3D models make their way into laboratories there is a need to develop characterisation techniques that are sensitive enough to monitor the cells in real time and without the need for chemical labels. Impedance spectroscopy has been shown to address both of these challenges, but there has been little research into the full impedance spectrum and how the different components of the system affect the impedance signal. Here we investigate the impedance of human fibroblast cells in 2D and 3D collagen gel cultures across a broad range of frequencies (10 Hz to 5 MHz) using a commercial well with in-plane electrodes. At low frequencies in both 2D and 3D models it was observed that protein adsorption influences the magnitude of the impedance for the cell-free samples. This effect was eliminated once cells were introduced to the systems. Cell proliferation could be monitored in 2D at intermediate frequencies (30 kHz). However, the in-plane electrodes were unable to detect any changes in the impedance at any frequency when the cells were cultured in the 3D collagen gel. The results suggest that in designing impedance measurement devices, both the nature and distribution of the cells within the 3D culture as well as the architecture of the electrodes are key variables.

Download Full-text

Collagen gel three-dimensional matrices combined with adhesive proteins stimulate neuronal differentiation of mesenchymal stem cells

Journal of The Royal Society Interface ◽

10.1098/rsif.2010.0613 ◽

2011 ◽

Vol 8 (60) ◽

pp. 998-1010 ◽

Cited By ~ 38

Author(s):

Jae Ho Lee ◽

Hye-Sun Yu ◽

Gil-Su Lee ◽

Aeri Ji ◽

Jung Keun Hyun ◽

...

Keyword(s):

Stem Cells ◽

Mesenchymal Stem Cells ◽

Neuronal Differentiation ◽

Large Population ◽

Three Dimensional ◽

Collagen Gel ◽

Cell Types ◽

Specific Cell ◽

Neuronal Outgrowth ◽

Adhesive Proteins

Three-dimensional gel matrices provide specialized microenvironments that mimic native tissues and enable stem cells to grow and differentiate into specific cell types. Here, we show that collagen three-dimensional gel matrices prepared in combination with adhesive proteins, such as fibronectin (FN) and laminin (LN), provide significant cues to the differentiation into neuronal lineage of mesenchymal stem cells (MSCs) derived from rat bone marrow. When cultured within either a three-dimensional collagen gel alone or one containing either FN or LN, and free of nerve growth factor (NGF), the MSCs showed the development of numerous neurite outgrowths. These were, however, not readily observed in two-dimensional culture without the use of NGF. Immunofluorescence staining, western blot and fluorescence-activated cell sorting analyses demonstrated that a large population of cells was positive for NeuN and glial fibrillary acidic protein, which are specific to neuronal cells, when cultured in the three-dimensional collagen gel. The dependence of the neuronal differentiation of MSCs on the adhesive proteins containing three-dimensional gel matrices is considered to be closely related to focal adhesion kinase (FAK) activation through integrin receptor binding, as revealed by an experiment showing no neuronal outgrowth in the FAK-knockdown cells and stimulation of integrin β1 gene. The results provided herein suggest the potential role of three-dimensional collagen-based gel matrices combined with adhesive proteins in the neuronal differentiation of MSCs, even without the use of chemical differentiation factors. Furthermore, these findings suggest that three-dimensional gel matrices might be useful as nerve-regenerative scaffolds.

Download Full-text