MATERIALS AND METHODS: Honey and some of its components, which include the sugars, the proteins, the hydrogen peroxide produced, and the phenolics, were exposed to cultured fibroblasts. The MTT colorimetric assay was used to assess cell viability and proliferation.
RESULTS: The stimulatory effect of honey on fibroblast proliferation was observed to be time- and dose-dependent. The continuous production of hydrogen peroxide by the honey-glucose oxidase system also acts to stimulate cell proliferation in a time- and dose-dependent manner. The presence of phenolics with antioxidant properties, on the other hand, renders protection to the cells against the toxic effect of hydrogen peroxide. However, the presence of a growth factor-like substance in honey could not be ascertained.
CONCLUSION: For the first time, honey and its major components were shown to exert stimulatory effects on cultured fibroblasts. Honey is therefore potentially useful in medicinal practices.
METHODS: Skeletal human muscle cells were cultured in four different conditions; control, EGF, laminin (Lam) and laminin EGF (Lam + EGF). Using live imaging system, their cellular properties; attachment, migration and growth were exposed to Rho kinase inhibitor, Y-27632, and EGF-receptor (EGF-R) inhibitor, gefitinib were measured.
RESULTS: Myoblast migration and proliferation was enhanced significantly by synergistic stimulation of laminin and EGF (0.61 ± 0.14 µm/min, 0.008 ± 0.001 h-1) compare to that by EGF alone (0.26 ± 0.13 µm/min, 0.004 ± 0.0009 h-1). However, no changes in proliferation and migration were observed for fibroblasts among the culture conditions. Inhibition of Rho kinase resulted in the increase of the myoblast migration on the laminin-coated surface with EGF condition (0.64 ± 0.18 µm/min). Compared to the untreated conditions, myoblasts cultured on the laminin-coated surface and EGF demonstrated elongated morphology, and average cell length increase significantly. In contrast, inhibition of EGF-R resulted in the decrease of myoblast migration on the laminin coated surface with EGF supplemented condition (0.43 ± 0.05 µm/min) in comparison to the untreated control (0.53 ± 0.05 µm/min).
CONCLUSION: Laminin and EGF preferentially enhance the proliferation and migration of myoblasts, and Rho kinase and EGF-R play a role in this synergistic effect. These results will be beneficial for the propagation of skeletal muscle cells for clinical applications.
DESIGN: Eighty-one extracted teeth were grouped into two age groups (6-25 years, 26-80 years). The teeth were demineralized and histological sections were prepared for cell count. Regression equations were generated from regression analysis of cell count and tested for age estimation.
RESULTS: The number of dental pulp cells were found to increase until around the third decade of life and following this, the odontoblasts and subodontoblasts cell numbers began to decline while the fibroblasts seemed to remain almost stationary. The Pearson correlation test revealed a significant positive correlation between the cell number for all type of cells and age in the 6-25 years group (r=+0.791 for odontoblasts, r=+0.600 for subodontoblasts and r=+0.680 for fibroblasts). In the 26-80 years age group, a significant negative correlation of the odontoblasts (r=-0.777) and subodontoblasts (r=-0.715) with age was observed but for fibroblasts, the correlation value was negligible (r=-0.165). Regression equations generated using odontoblasts and subodontoblasts cell number were applicable for age estimation. The standard error of estimates (SEEs) were around±5years for 6-25 years and±8years for 26-80 years age groups. The mean values of the estimated and chronological ages were not significantly different.
CONCLUSIONS: A significant correlation between the cell count of odontoblasts and subodontoblasts with age was demonstrated. Regression equations using odontoblasts and subodontoblasts cell number can be used to predict age with some limitations.
OBJECTIVE: This paper highlights the similarities and differences among these cell subpopulations, particularly between intraoral fibroblasts (human periodontal ligament, gingival and oral mucosa fibroblasts) and dermal fibroblasts based on several factors including their morphology, growth and proliferation rate.
RESULTS: It could be suggested that each subpopulation of fibroblasts demonstrate different positionspecified gene signatures and responses towards extracellular signals. These dissimilarities are crucial to be taken into consideration to employ specific methodologies in stimulating these cells in vivo.
CONCLUSION: A comparison of the characteristics of these cell subpopulations is desired for identifying appropriate cellular applications.
METHODS: Whole proteins were extracted and digested in-gel with trypsin. Peptides were detected by Orbitrap liquid chromatography mass spectrometry. Mass spectra were identified and quantitated by MaxQuant software. The data were further filtered and analyzed statistically using Perseus software to identify DEPs. Functional annotations of DEPs were performed using Panther Classification System.
RESULTS: A total of 1217 proteins were identified in young and senescent cells, while 1218 proteins in vehicle- and γT3-treated senescent cells. 11 DEPs were found in young and senescent cells which included downregulation of platelet-derived growth factor (PDGF) receptor beta and upregulation of tubulin beta-2A chain protein expressions in senescent cells. 51 DEPs were identified in vehicle- and γT3-treated senescent cells which included upregulation of 70 kDa heat shock protein, triosephosphate isomerase and malate dehydrogenase protein expressions in γT3-treated senescent cells.
CONCLUSIONS: PDGF signaling and cytoskeletal structure may be dysregulated in senescent HDFs. The pro-proliferative effect of γT3 on senescent HDFs may be mediated through the stimulation of cellular response to stress and carbohydrate metabolism. The expressions and roles of these proteins in relation to cellular senescence are worth further investigations. Data are available via ProteomeXchange with identifier PXD009933.
MATERIALS AND METHODS: In this study, reprogramming of human dermal fibroblasts (NHDF) into iPSC was carried out using non-integrative Sendai virus for transduction. The iPSC clones were characterised based on the morphological changes, gene expression of pluripotency markers, and spontaneous and directed differentiation abilities into cells of different germ layers.
RESULTS: On day 18-25 post-transduction, colonies with embryonic stem cell-like morphology were obtained. The iPSC generated were free of Sendai genome and transgene after passage 10, as confirmed by RT-PCR. NHDF-derived iPSC expressed multiple pluripotency markers in qRT-PCR and immunofluorescence staining. When cultured in suspension for 8 days, iPSC successfully formed embryoid body-like spheres. NHDF-derived iPSC also demonstrated the ability to undergo directed differentiation into ectoderm and endoderm.
CONCLUSION: NHDF were successfully reprogrammed into iPSC using non-integrating Sendai virus for transduction.
MATERIALS AND METHODS: The differentiation of fibroblast-like cells from SHED was carried out by using specific human recombinant connective tissue growth factor (CTGF). To characterize fibroblastic differentiation, the induced cells were subjected to morphological changes, proliferation rate, gene expression analysis using quantitative reverse transcription-polymerase chain reaction (qRT-PCR), flow cytometry, and immunofluorescence staining. The commercial primary human gingival fibroblasts served as positive control in this study.
RESULTS: The results from characterization analysis were compared with that of commercial cells to ensure that the cells differentiated from SHED were fibroblast-like cells. The results showed the inductive effect of CTGF for fibroblastic differentiation in SHED. SHED-derived fibroblasts were successfully characterized despite having similar morphological appearance, i.e., (i) significant proliferation rate between fibroblast-like cells and SHED, (ii) high expression of fibroblast-associated markers in qRT-PCR analysis, and (iii) positive staining against collagen type 1, fibroblast-specific protein 1, and human thymic fibroblasts in flow cytometry analysis and immunofluorescence staining. The same expression patterns were found in primary human gingival fibroblasts, respectively. SHED as negative control showed lower expression or no signal, thus confirming the cells differentiated from SHED were fibroblast-like cells.
CONCLUSIONS: Taken together, the protocol adopted in this study suggests CTGF to be an appropriate inducer in the differentiation of SHED into fibroblast-like cells.
CLINICAL RELEVANCE: The fibroblast-like cells differentiated from SHED could be used in future in vitro and in vivo dental tissue regeneration studies as well as in clinical applications where these cells are needed.