TẠO DÒNG VÀ BIỂU HIỆN PROTEIN hGM-CSF TRÊN TẾ BÀO CHO K1

GM-CSF (granulocyte-macrophage colony stimulating factor) is a cytokine with wide effects, not only on hematopoietic precursor cells, dendritic cells, but also on smooth muscle cells, epithelial cells and even neurons. Although, it does not play role in hGM-CSF biological functions, glycosylation enhances the protein in vivo stability. Therapeutic drugs containing recombinant hGM-CSF are mostly produced in Escherichia coli or Saccharomyces cerevisiae, which do not have post-translation modification mechanisms similar to those of humans. In this present study, the gene encoding for human (h)GM-CSF was transfected into the Chinese Ovary Cell (CHO)-K1 and expression of the protein was evaluated. Firstly, gene was inserted into the open reading frame after early promoter CMV at EcoRI and XhoI restriction sites. Recombinant vectors are screened by colony PCR, restriction enzyme digestion and sequencing. The recombinant vector was termed pcDNA-hGM and was transfected into CHO-K1 cells using cationic lipid method. Transformants was selected and maintained using antibiotic Geneticin. The results showed that the gene encoding for hGM-CSF was indeed cloned into pcDNA3.1+ vector at EcoRI and XhoI restriction sites. The conditioned medium collected from CHO‑K1/pcDNA-hGM stimulated the proliferation of TF-1, an hGM-CSF-dependent cell line. In summary, the recombinant vector pcDNA-hGM was cloned and the recombinant cell line CHO‑K1/pcDNA-hGM expressed active hGM-CSF. This is the first research on expression hGM-CSF in CHO-K1 cell line and providing evidence for further investigation on isolation and purification of hGM-CSF afterward.Nhân tố kích thích tạo cụm bạch cầu hạt và đại thực bào người (hGM-CSF, human granulocyte-macrophage colony stimulating factor) là một cytokine có phổ tác dụng rộng trong cơ thể, từ các tế bào tiền thân tạo máu, tế bào tua, đến tế bào cơ trơn, tế bào biểu mô và cả một số tế bào thần kinh. Sự glycosyl hóa, dù không đóng vai trò trong tương tác với thụ thể nhưng có tác dụng làm tăng độ bền cho hGM-CSF ở điều kiện in vivo. Những sản phẩm hGM-CSF tái tổ hợp sử dụng rộng rãi hiện nay chủ yếu được sản xuất từ Echerichia coli và Saccharomyces cerevisiae, những loại tế bào chủ không có bộ máy biến đổi sau dịch mã giống người. Trong nghiên cứu này, gene hgm-csf mã hóa cho protein hGM‑CSF được chuyển vào trong tế bào buồng trứng chuột hamster Trung Quốc (CHO-K1 cells) và đánh giá khả năng biểu hiện protein. Trước tiên, gene được chèn vào plasmid pcDNA3.1+ đúng khung đọc mở ngay sau promoter CMV tại vị trí EcoRI và XhoI. Plasmid tái tổ hợp được sàng lọc bằng PCR khuẩn lạc với cặp mồi đặc hiệu, cắt giới hạn và giải trình tự. Plasmid tái tổ hợp sau quá trình kiểm tra được đặt tên pcDNA-hGM. Sau đó, plasmid tái tổ hợp đưa vào tế bào CHO-K1 bằng phương pháp biến nạp sử dụng cationic lipid và nuôi chọn lọc bằng kháng sinh Geneticin. Kết quả cho thấy gene hgm-csf đã được dòng hoá vào plasmid pcDNA3.1+ tại vị trí EcoRI và XhoI. Dịch môi trường nuôi tế bào CHO-K1/ pcDNA‑hGM cho thấy khả năng kích thích sự tăng sinh của dòng tế bào TF-1, dòng tế bào sống phụ thuộc hGM-CSF. Như vậy, plasmid tái tổ hợp pcDNA-hGM đã được cấu trúc thành công và dòng tế bào mang gene tái tổ hợp CHO‑K1/pcDNA-hGM biểu hiện protein hGM‑CSF có hoạt tính. Đây là nghiên cứu đầu tiên về biểu hiện hGM-CSF trên tế bào CHO-K1 ở Việt Nam và là cơ sở cho bước khảo sát các điều kiện thu nhận và tinh chế hGM-CSF tiếp sau

Corporate social responsibility and behavioral intentions in an emerging market: The mediating roles of green brand image and green trust

This study is driven by the absence of thorough investigations into the behavioral intentions of organizational consumers in the B2B market for paint and coatings, particularly within the industrial and marine coatings sector in Vietnam. Employing the stimulus–organism–response model, we tested the relationship between corporate social responsibility (CSR), green brand image (GBI), green trust (GT), and behavioral intentions (word-of-mouth intention, willingness to pay, and purchase intention) in the Vietnamese industrial and marine coatings industry. We also examined how GBI and GT mediate the relationship between CSR and behavioral intentions. Structural equation modeling was used to test the structural and measurement models and hypothetical relationships. The sample comprised 332 responses from stakeholders in the Vietnamese coating industry. Evidently, GT and CSR positively influenced word-of-mouth, willingness-to-pay, and green purchase intentions, with trust and commitment to sustainability being important drivers. While GBI positively influences purchase intention and willingness-to-pay, it has a weak effect on word-of-mouth intention, indicating that additional strategies are needed to stimulate word of mouth. Further, GT mediates the relationship between green purchase intentions and GBI, as well as between CSR and green purchase intentions. The outcomes highlight the value of incorporating CSR, GT, and GBI into the business strategies of Vietnamese industrial and marine coating companies. We discuss several theoretical and managerial implications, and the importance of studying the influence of GT, CSR, and GBI on consumers’ behavioral intentions across various cultural contexts

CRITIC Method and Grey System Theory in the Study of Global Electric Cars

Science and technology development is a crucial for the elimination of air pollutants. The electric car industry, for example, contributes to minimizing emissions and climate change. The purpose of this study is to present an overview of electric car sales and its market share in 14 countries, from past to future, by integrating important criteria through the inter-criteria correlation (CRITIC) method in multi-criteria decision-making (MCDM), grey model first-order one variables (GM(1,1)), and grey relation analysis (GRA) method in grey system theory. First, the GM(1,1) estimates future terms based on historical time-series. Second, the objective weights of each variable, in every year, are determined by the CRITIC method. Finally, the research uses the GRA method for computing grades and ranks. The empirical result then reveals the performance and rank of electric car sales during the time period of 2016–2023. The analysis results thus reveal market share picture and direction of growth in the electric car industry