Cloning, Expression, and Cost Effective Purification of Authentic Human Epidermal Growth Factor With High Activity

Combination of Pinocembrin and Epidermal Growth Factor Enhances the Proliferation and Survival of Human Keratinocytes

Re-epithelialization is delayed in aged skin due to a slow rate of keratinocyte proliferation, and this may cause complications. Thus, there has been development of new therapies that increase treatment efficacy for skin wounds. Epidermal growth factor (EGF) has been clinically used, but this agent is expensive, and its activity is less stable. Therefore, a stable compound possessing EGF-like properties may be an effective therapy, especially when combined with EGF. The current study discovered that pinocembrin (PC) effectively synergized with EGF in increasing keratinocyte viability. The combination of PC and EGF significantly enhanced the proliferation and wound closure rate of the keratinocyte monolayer through activating the phosphorylation of ERK and Akt. Although these effects of PC were like those of EGF, we clearly proved that PC did not transactivate EGFR. Recent data from a previous study revealed that PC activates G-protein-coupled receptor 120 which further activates ERK1/2 and Akt phosphorylation. Therefore, this clearly indicates that PC possesses a unique property to stimulate the growth and survival of keratinocytes through activating a different receptor, which subsequently conveys the signal to cross-talk with the effector kinases downstream of the EGFR, suggesting that PC is a potential compound to be combined with EGF.

Isoprocurcumenol Supports Keratinocyte Growth and Survival through Epidermal Growth Factor Receptor Activation

Although proliferation of keratinocytes, a major type of skin cells, is a key factor in maintaining the function of skin, their ability to proliferate tends to diminish with age. To solve such a problem, researchers in medical and skin cosmetic fields have tried to utilize epidermal growth factor (EGF), but achieved limited success. Therefore, a small natural compound that can mimic the activity of EGF is highly desired in both medical and cosmetic fields. Here, using the modified biosensor system, we observed that natural small-compound isoprocurcumenol, which is a terpenoid molecule derived from turmeric, can activate EGFR signaling. It increased the phosphorylation of ERK and AKT, and upregulated the expression of genes related to cell growth and proliferation, such as c-myc, c-jun, c-fos, and egr-1. In addition, isoprocurcumenol induced the proliferation of keratinocytes in both physical and UVB-induced cellular damage, indicative of its function in skin regeneration. These findings reveal that EGF-like isoprocurcumenol promotes the proliferation of keratinocytes and further suggest its potential as an ingredient for medical and cosmetics use.

Development of a Fast Organic Extraction-Precipitation Method for Improved Purification of Elastin-Like Polypeptides That Is Independent of Sequence and Molecular Weight

Elastin-like polypeptides (ELP), an increasingly popular tag for protein purification, commonly rely upon inverse transition cycling (ITC) to exploit their lower critical solution temperature characteristics for purification. While considerably faster than chromatography, ITC is still time consuming and often fails to remove host cell contaminants to an acceptable level for in vivo experiments. Here, we present a rapid purification workflow for ELP of broadly varying molecular weight and sequence using a polar organic solvent extraction and precipitation strategy. Four different ELP purification methods were directly compared for their ability to remove host cell protein, nucleic acids, and lipopolysaccharide (LPS) contaminants using a model ELP. On the basis of these findings, an optimized extraction-precipitation method was developed that gave highly pure ELP from bacterial pellets in approximately 2.5 h while removing major host cell contaminants, including LPS to levels below 1 EU/mL, to produce highly pure material that is suitable for in vivo applications. Application of this method to the rapid purification of an ELP-epidermal growth factor fusion gave an isolate that retained its capacity to bind to epidermal growth factor receptor positive cells, thereby demonstrating that this method is capable of producing a functional construct after purification by organic extraction-precipitation.

Expression, purification and functional identification of the modified hEGF protein

Human epidermal growth factor (hEGF) plays an important role in the growth and division of epithelial cells and has good application prospects in skin-related injuries and diseases. Weak skin penetration and rapid clearance of hEGF in skin via the mononuclear phagocyte system have restricted the application of hEGF. To overcome these shortcomings, the recombinant gene TAT-hEGF-CD47 was constructed in our experiments, and the fusion protein TAT-hEGF-CD47 was expressed, purified and renatured. The cell proliferation-promoting function, skin penetration and concentration of TAT-hEGF-CD47 in skin after its application were determined. The results showed that TAT-hEGF-CD47 effectively promoted human skin fibroblast and skin epithelial cell proliferation, and the proliferation-promoting effect was positively correlated with the TAT-hEGF-CD47 concentration. After administration to the skin, TAT-hEGF-CD47 effectively penetrated the epidermal layer of the skin because of the TAT domain and stayed in the skin for a long time because the CD47 fragment slowed its clearance via the mononuclear phagocytic system. In conclusion, TAT-hEGF-CD47 exhibits high cell proliferation-promoting activity, high skin penetration efficiency and long retention time in skin and has laid the foundation for its wide application in skin repair, ulcer, diabetes and even cancer treatments.

Activity and Effectiveness of Recombinant hEGF Excreted by Escherichia coli BL21 on Wound Healing in Induced Diabetic Mice

Context

Human epidermal growth factor (hEGF) has biological activities and can be used in medicines and cosmetics. A high level of effectiveness of hEGF can be obtained when three disulfide bonds fold perfectly. Extracellular secretion from E. coli BL21 using the PelB signal peptide is a new way to obtain hEGF with a structure that folds appropriately.

Object

This study aimed to determine the activity and effectiveness of recombinant hEGF excreted by E. coli BL21 on wound healing in induced diabetic mice.

Methods

Cell proliferation and migration tests were performed on NIH3T3 cells, followed by wound healing tests in induced diabetic mice, along with histological and endotoxin test at various hEGF concentrations (25, 50, and 75 µg/mL).

Results

Based on the results, hEGF at a level of 50 μg/mL showed optimal proliferation and migration activities. Wound healing in induced diabetic mice showed faster-wound closure within 12 days at hEGF 50 and 75 µg/mL with a percentage wound closure of 95% and 98.5%, respectively, which was significant versus control. In the histology test, the number of fibroblasts showed an increase and was significant at hEGF 75 µg/mL compared to the control group. The single test vial (STV) showed that hEGF solution was free of endotoxin.

Conclusion

Recombinant hEGF produced by extracellular secretion using E. coli BL21 has optimal diabetic wound healing activity through increased fibroblast proliferation.

Efficient production of human zona pellucida-3 in a prokaryotic expression system

The zona pellucida-3 (ZP3) protein plays a pivotal role in oocyte and gamete development. We aimed to produce a recombinant ZP3 peptide using the Escherichia coli secretory system and apply it to a protein chip for detecting anti-ZP3 antibodies. The ZP3 gene was cloned into the pHOA downstream of the phoA promoter and transformed into E. coli YK537. Recombinant ZP3 was secretory expressed by decreasing the inorganic phosphate concentration. Then, rZP3 was purified and coated onto a protein chip, which was used to detect AZP3A in serum samples from 63 infertile patients. The area under the receiver operating characteristic curve was 0.934. The results, in terms of AZP3A detection, of the rZP3-coated protein chip were consistent with those of the ELISA kit. Therefore, our protein chip assay has potential for diagnosis of infertility due to AZP3A, and represents a less costly and simpler assay for clinical and research applications.

Piperonylic acid stimulates keratinocyte growth and survival by activating epidermal growth factor receptor (EGFR)

Epidermal growth factor (EGF) stimulates cell growth, proliferation, and survival. The biological benefits of EGF have been utilized in medical uses for improving wound healing as well as in today’s skin cosmetics. EGF has been found in urine, saliva, milk, and plasma, but its efficient isolation remains a difficult task. With technical advances, recombinant protein purification technique has been used for EGF production. However, the recombinant EGF is still expensive and keeping it with stable activity is difficult to be used widely. Thus, a molecule that can mimic the EGF activity would be a useful alternative of EGF. Herein, we have discovered that a natural small molecule piperonylic acid shows EGF-like activity in HaCaT keratinocytes. Piperonylic acid induced EGF receptor (EGFR) activation and resulted in serial activation of the downstream modulators. The activated signaling pathway eventually up-regulated gene expression of egr-1, c-fos, c-jun, and c-myc, which are involved in cell growth and survival. Moreover, piperonylic acid showed promoting role in keratinocyte growth and survival from UVB-induced cellular damages. This study has revealed the EGF-like activity of piperonylic acid and proposed that the piperonylic acid could be a promising component for skin wound healing agents or cosmetic ingredient.