Search

Objective: To construct the tissue engineering seed cell (HaCaT cell line) with stable expression of the human epidermal growth factor (EGF), and analyze the changes of its biological characteristics., Methods: PCDNA3.1-EGF eukaryotic expression vector was transferred into HaCaT cell, and G418 was utilized to select the HaCaT-EGF cell line. Using an inverted microscope, PCR, ELISA method to detect the changes of the cell morphology, the expression of the EGF gene and protein, and the mRNA expression levels of apoptosis related molecule Caspase-3, the cell cycle related protein cyclin D1., Results: The mRNA expression levels of the obtained HaCaT-EGF cell were more than 100 times higher than the level of ordinary HaCaT cell. The colony of the HaCaT-EGF cells was more focused and tight compared to the empty vector transfected HaCaT cells and normal HaCaT cells. The expression levels of apoptotic factor Caspase-3 and cyclin D1 in HaCaT-EGF cell were significantly higher than those in the empty vector HaCaT- pcDNA3.1 cell, and the differences were statistically significant (P<0.01), but there was no significant difference compared to the normal HaCaT cells (P>0.05)., Conclusions: HaCaT-EGF cell can continuously secrete EGF, and the biological characteristic is stable. It can be used for tissue engineering experiment and is an ideal seed cell for constructing tissue engineered skin., (Copyright © 2013 Hainan Medical College. Published by Elsevier B.V. All rights reserved.)

This study aimed to investigate the feasibility of using an immortal keratinocyte cell line, HaCaT cells, to effectively deliver epidermal growth factor (EGF) in a skin substitute to treat burn wounds. The skin equivalent was constructed with human EGF (hEGF) gene modified HaCaT cells obtained through stable gene transfection; these were applied to full thickness burn wounds in a rat model. The results showed that the hEGF gene modified HaCaT cells produced more than 390ng/l of bioactive hEGF in the culture supernatant. K19 and integrin-β1 as keratinocyte differentiation markers were elevated in the hEGF gene modified HaCaT cells which were shown to be non-tumorigenic. The skin equivalent constructed with hEGF gene modified HaCaT cells demonstrated improved epidermal morphogenesis with a thick and compact epidermis. Wound healing was accelerated noticeably when applied with this skin substitute seeded with hEGF gene modified HaCaT cells in vivo. The results suggest that HaCaT cells modified with hEGF gene might be promising seed cells for construction of genetically modified skin substitute which can effectively secrete hEGF to accelerate wound repair and regeneration., (Copyright © 2012 Elsevier Ltd and ISBI. All rights reserved.)

Objective: To compare the difference of protein expression in the supernatant of heat injured keratinocytes (KC) and normal KC., Methods: A model of heat injured KC was produced in vitro. The supernatant of normal KC and heat injured KC was collected after culture for 12 hours, and was ultrafiltered and lyophilized to get the protein. The protein sample was separated by immobilized pH gradient based two dimensional gel electrophoresis (2-DE). The gel was stained and the different expression of protein was analyzed using ImageMaster 2D analysis software., Results: (1) Average protein spots were 1,898 +/- 113, 1,877 +/- 97 in the supernatant of normal and heat injured KC and 1,118 protein spots could be used for statistical analysis. (2) Statistical result showed that 26 protein spots were significantly different between the two groups. 16 protein spots were higher in the supernatant of normal KC and then 10 protein spots were lower in the normal group. (3) 16 protein spots, which included 10 kinds of proteins, were identified successfully as different spots. Lower expression proteins were alpha-enolase, actin cytoplasmic 2, peroxiredoxin-4, phosphoglycerate mutase 1, G protein-regulated inducer of neurite outgrowth l in the supernatant of heat injured KC. Higher expression proteins in heat KC were purine nucleoside phosphorylase, tumor necrosis factor ligand superfamily member 10, proteasome subunit alpha type-7, UDP-glucose 6-dehydrogenase in the supernatant of heat injured KC., Conclusions: The result indicated that there are some significant different expression proteins in the supernatant of normal KC and heat injured KC. These findings provide new data for screening major molecules of tissue repair and finding the mechanism of wound repair.

Objective: To observe the effect of the supernatant of heat injured keratinocytes (KC) on biological behavior of the dermal fibroblasts (Fb)., Methods: Human dermal Fb were isolated and cultured. A model of heat injured KC (HaCaT) was reproduced in vitro. Supernatant of normal KC and the supernatant of KC culture 12 hours after heat injury were collected and diluted with non-serum DMEM in 1:1 volume ratio to make normal KC conditioned medium (NKCM) and heat injury KC conditioned medium (HKCM) respectively. Fb was respectively treated with non-serum DMEM and 2 kinds of conditioned medium. (1) The proliferation of Fb was detected with MTT method at post culture hour (PCH) 12, 24, 36, 48. (2) The apoptosis of Fb was determined by flow cytometry at PCH 12 (Fb were heat injured in advance; Fb without heat treatment was used as control). (3) At PCH 24, expression of a-SMA in Fb cytoplasm was determined with immunofluorescence method; expression of a-SMA mRNA in Fb was determined with real-time quantified PCR. Data were processed with one-way analysis of variance, and pairwise comparison among groups with LSD-t test., Results: (1) The proliferation of Fb: the absorbance value of Fb cultured with HKCM at PCH 12, 24, 36, 48 was respectively higher than that of Fb cultured with non-serum DMEM (with t value respectively 1.89, 2.35, 2.02, 1.94, and P values all below 0.01). There were significant statistical differences between the absorbance values of Fb cultured with HKCM and those of Fb cultured with NKCM at PCH 12, 24, and 48 (at PCH 12, t = 1.83, P < 0.01; at PCH 24, t = 2.91, P < 0.05; at PCH 48, t = 1.83, P < 0.05). (2) Apoptosis of Fb cultured with HKCM was diminished as compared with that of Fb cultured with NKCM and of Fb without treatment (t = 3.31, P < 0.05; t = 1.47, P < 0.01). (3) The expression of alpha-SMA (red fluorescence) in Fb cultured with non-serum DMEM or NKCM was less as seen under fluorescence scope, and it was obviously increased in Fb cultured with HKCM. (4) The relative expression amount of alpha-SMA mRNA in Fb cultured with HKCM was 1.32 +/- 0.06, which was higher than that both in Fb cultured with NKCM (1.14 +/- 0.07, t = 2.51, P < 0.05) and in Fb cultured with non-serum DMEM (1.00 +/- 0.09, t = 1.77, P < 0.05)., Conclusions: The supernatant of KC 12 hours after heat injury can obviously promote the proliferation of Fb, inhibit its apoptosis and accelerate transdifferentiation of Fb to myofibroblasts.