Cloning, expression and purification of human PDGF-BB gene in Escherichia coli: New approach in PDGF-BB protein production

The effect of oral treatment of royal jelly on the expression of the PDGF-β gene in the skin wound of male mice

AIMS OF THE STUDY

Royal jelly (RJ) is one of the most widely used drugs in traditional medicine. One of its important applications is the repair of skin damage, although the path of its mechanism is still unknown. Platelet-derived growth factor-beta (PDGF-beta) is one of the important factors in wound healing and it has been observed that PDGF-β expression decreases with increasing age. In this study, for the first time, the effect of RJ on skin wounds has been investigated through the expression of PDGF-β and tissue studies.

MATERIALS AND METHODS

25 small laboratory male BALB/c mice were selected randomly and after creating a 5 mm wound on the back of their neck, they were treated with doses of 2.5, 10, and 40 mg/kg body weight, After sampling from the healed wound in 9th day, histopathological studies and the expression of PDGF-β gene were performed by Real-time PCR method.

RESULTS

The findings of the present study showed that royal jelly caused a significant increase in PDGF-β (10.99 times) compared to the healthy group. Also, royal jelly increased the formation of covering tissue or epithelium, the synthesis of collagen, the presence of inflammatory cells, and the formation of new blood vessels.

CONCLUSION

The oral treatment of royal jelly is probably effective in skin wound healing by changing the expression of PDGF-β.

Generation of a recombinant version of a biologically active cell-permeant human HAND2 transcription factor from E. coli

Transcription factor HAND2 has a significant role in vascularization, angiogenesis, and cardiac neural crest development. It is one of the key cardiac factors crucial for the enhanced derivation of functional and mature myocytes from non-myocyte cells. Here, we report the generation of the recombinant human HAND2 fusion protein from the heterologous system. First, we cloned the full-length human HAND2 gene (only protein-coding sequence) after codon optimization along with the fusion tags (for cell penetration, nuclear translocation, and affinity purification) into the expression vector. We then transformed and expressed it in Escherichia coli strain, BL21(DE3). Next, the effect (in terms of expression) of tagging fusion tags with this recombinant protein at two different terminals was also investigated. Using affinity chromatography, we established the one-step homogeneous purification of recombinant human HAND2 fusion protein; and through circular dichroism spectroscopy, we established that this purified protein had retained its secondary structure. We then showed that this purified human protein could transduce the human cells and translocate to its nucleus. The generated recombinant HAND2 fusion protein showed angiogenic potential in the ex vivo chicken embryo model. Following transduction in MEF2C overexpressing cardiomyoblast cells, this purified recombinant protein synergistically activated the α-MHC promoter and induced GFP expression in the α-MHC-eGFP reporter assay. Prospectively, the purified bioactive recombinant HAND2 protein can potentially be a safe and effective molecular tool in the direct cardiac reprogramming process and other biological applications.

Identification of Optimal Expression Parameters and Purification of a Codon-Optimized Human GLIS1 Transcription Factor from Escherichia coli

GLIS1 has multiple roles in embryonic development and in deriving induced pluripotent stem cells by aiding signaling pathways and chromatin assembly. An inexpensive and simple method to produce human GLIS1 protein from Escherichia coli (E. coli) is demonstrated in this study. Various parameters such as codon usage bias, E. coli strains, media, induction conditions (such as inducer concentration, cell density, time, and temperature), and genetic constructs were investigated to obtain soluble expression of human GLIS1 protein. Using identified expression conditions and an appropriate genetic construct, the human GLIS1 protein was homogeneously purified (purity > 90%) under native conditions. Importantly, the purified protein has upheld a stable secondary structure, as demonstrated by circular dichroism spectroscopy. To the best of our knowledge, this is the first study to report the ideal expression conditions of human GLIS1 protein in E. coli to achieve soluble expression and purification under native conditions, upholding its stable secondary structure post-purification. The biological activity of the purified GLIS1 fusion protein was further assessed in MDA-MB-231 cells. This biologically active human GLIS1 protein potentiates new avenues to understand its molecular mechanisms in different cellular functions in various cancers and in the generation of induced pluripotent stem cells.

Soluble expression, purification, and secondary structure determination of human MESP1 transcription factor

Transcription factor MESP1 is a crucial factor regulating cardiac, hematopoietic, and skeletal myogenic development. Besides, it also contributes to the generation of functional cardiomyocytes. Here, we report the soluble expression and purification of the full-length human MESP1 protein from the heterologous system, which can be delivered into the target mammalian cells. To generate this biological macromolecule, we cloned its codon-optimized gene sequence fused to a nuclear localization sequence, a cell-penetrating peptide, and a His-tag into the protein expression vector and expressed in the bacterial system (E. coli strain BL21(DE3)). Subsequently, we have screened and identified the optimal expression parameters to obtain this recombinant fusion protein in soluble form from E. coli and examined its expression concerning the placement of fusion tags at either terminal. Further, we have purified this recombinant fusion protein to homogeneity under native conditions. Notably, this purified fusion protein has maintained its secondary structure after purification, primarily comprising α-helices and random coils. This molecular tool can potentially replace its genetic and viral forms in the cardiac reprogramming of fibroblasts to induce a cardiac transcriptional profile in an integration-free manner and elucidating its role in various biological processes and diseases. KEY POINTS: • Screening of the suitable gene construct was performed and identified. • Screening of optimal expression conditions was performed and identified. • Native purification of recombinant human MESP1 protein from E. coli was performed. • Recombinant MESP1 protein has retained its secondary structure after purification.

Generation of a Recombinant Stem Cell-Specific Human SOX2 Protein from Escherichia coli Under Native Conditions

The stem cell-specific SOX2 transcription factor is critical for early embryonic development and the maintenance of embryonic and neural stem cell identity. It is also crucial for the generation of induced pluripotent and neural stem cells, thus providing immense prospect in patient-specific therapies. Here, we report soluble expression and purification of human SOX2 protein under native conditions from a bacterial system. To generate this macromolecule, we codon-optimized the protein-coding sequence and fused it to a nuclear localization signal, a protein transduction domain, and a His-tag. This was then cloned into a protein expression vector and was expressed in Escherichia coli. Subsequently, we have screened and identified the optimal expression conditions to obtain recombinant fusion protein in a soluble form and studied its expression concerning the position of fusion tags at either terminal. Furthermore, we purified two versions of recombinant SOX2 fusion proteins to homogeneity under native conditions and demonstrated that they maintained their secondary structure. This molecular tool can substitute genetic and viral forms of SOX2 to facilitate the derivation of integration-free induced pluripotent and neural stem cells. Furthermore, it can be used in elucidating its role in stem cells, various cellular processes and diseases, and for structural and biochemical studies.