An engineered hypoxia-response promoter for human umbilical cord-derived mesenchymal stem cell-based therapeutics
Myocardial infarction, characterized by insufficient blood supply to the heart, leads to ischemia and hypoxia of myocardial tissues, causing injury and decreased cardiac function. Despite improvements in pharmaceutical and interventional therapies, it remains a leading cause of death worldwide. Human umbilical cord mesenchymal stem cells (hUC-MSCs) play an important role in the repair of infarcted myocardium by promoting angiogenesis, reducing inflammation, secreting growth factors and cytokines. However, the harsh hypoxic microenvironment of infarcted myocardial tissue poses a threat to the survival and function of transplanted hUC-MSCs. In this study, we modified the candidate gene promoter of hUC-MSCs under hypoxic conditions and created a promoter that can respond quickly under hypoxic conditions. We found that the modified promoter significantly promoted the transcription efficiency as hypoxia time increased. This indicates that the engineered hypoxia-response promoter can effectively drive gene expression in a hypoxic environment. Furthermore, the transcription efficiency of the modified promoter under normoxic conditions is lower than that of common promoters in eukaryotic organisms, suggesting that this effect can improve the efficacy and safety of hUC-MSC-based myocardial infarction treatment by ensuring that cells function effectively in the damaged hypoxic area. Overall design: We cultured hUC-MSCs under hypoxic (1% oxygen) and normoxic conditions, respectively. We then collected cell samples from the hypoxic culture group at 2 hours, 6 hours, 24 hours, and 72 hours, and from the normoxic culture group at 24 hours. Total cellular RNA was extracted for transcriptome sequencing analysis. By analyzing and comparing the gene expression changes in hUC-MSCs from each hypoxic time group with those from the normoxic 24-hour group based on the sequencing results, we aimed to identify potential genes with continuously upregulated expression in hUC-MSCs as the hypoxic time increased.