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The epithelial mesenchymal transition (EMT) plays significant roles in the progression of cancer and fibrotic disease. Moreover, this process is reversible, resulting in mesenchymal epithelial transition (MET), which plays an important role in cancer metastasis. There is a lack of methods to trace and target EMT cells using synthetic biology circuits, which makes it difficult to study the cell fate or develop targeted treatments. In this study, we introduced responsive EMT sensing circuits, which sense the EMT using specific promoters that respond to transcription factors typical of EMT activation (EMT-TFs). The transcriptional strength of EMT-sensing promoters decreased more than 13-fold in response to the overexpression of the EMT-TF. Then, the NOT gate circuits were built by placing the tetR transcription repressor under the control of EMT sensing promoters and expressed an output signal using the constitutive CMV promoter modified with tetO sites This circuit is named EMT sensing and responding circuits .When the EMT transcription factors was present, we observed a 5.8-fold signal increase in the system. Then, we successfully distinguished mesenchymal breast cancer cells from epithelial cancer cells and repressed the proliferation of EMT tumor cells using our circuits. The EMT sensing and responding circuits are promising tools for the identification of EMT cells, which is crucial for EMT-related disease therapy and investigating the mechanisms underlying the reversible EMT process.

Abstract Background Translational failures in anti-adhesion molecule therapies after stroke reveal the necessity of developing new strategies that not only interrupt leukocyte recruitment but also consider the inhibition of endothelial cell inflammation, verification of therapeutic time window, and normal function maintenance of circulating leukocytes. Our study focused on the potential therapeutic value of CD151 downregulation in improving current anti-adhesion molecule therapies. Methods Lentivirus intracerebroventricular administration was conducted to inhibit the CD151 expression and observe its functional influence on neurological injuries and outcomes. Then, immunohistochemistry and myeloperoxidase activity assessment were performed to explore the effects of CD151 expression on neutrophil and monocyte recruitment after rat cerebral ischemia. Primary rat brain microvascular endothelial cells were subjected to oxygen glucose deprivation and reoxygenation to elucidate the underlying working mechanisms between CD151 and VCAM-1. Results The CD151 downregulation remarkably reduced neurological injuries and improved neurological outcomes, which were accompanied with reduced neutrophil and monocyte infiltration after the CD151 downregulation. The VCAM-1 expression was remarkably decreased among the adhesion molecules on the endothelial cell responsible for neutrophil and monocyte infiltration. The activation of p38 MAPK and NF-κB pathways was restricted after the CD151 downregulation. p38 MAPK and NF-κB inhibitors decreased the VCAM-1 expression, and p38 acted as an upstream regulator of NF-κB. However, CD151 downregulation did not directly influence the neutrophil and monocyte activation. Conclusions Overall, CD151 regulated the expression of adhesion molecules. It also played a critical role in suppressing VCAM-1-mediated neutrophil and monocyte infiltration via the p38/NF-κB pathway. This study possibly provided a new basis for improving current anti-adhesion molecule therapies.

Abstract The endothelial-to-mesenchymal transition (EndMT) is an important source of fibrotic cells in idiopathic pulmonary fibrosis (IPF). However, how endothelial cells (ECs) are activated and how EndMT impact IPF remain largely elusive. Here, we use unsupervised pseudotemporal analysis to recognize the heterogeneity of ECs and reconstruct EndMT trajectory of bleomycin (BLM)-treated Tie2 creER/+ ;Rosa26 tdTomato/+ IPF mice. Genes like C3ar1 and Lgals3 (protein name galectin-3) are highly correlated with the transitional pseudotime, whose expression is gradually upregulated during the fate switch of ECs from quiescence to activation in fibrosis. Inhibition of galectin-3 via siRNA or protein antagonists in mice could alleviate the pathogenesis of IPF and the transition of ECs. With the stimulation of human pulmonary microvascular endothelial cells (HPMECs) by recombinant proteins and/or siRNAs for galectin-3 in vitro, β-catenin/GSK3β signaling and its upstream regulator AKT are perturbed, which indicates they mediate the EndMT progress. These results suggest that EndMT is essential to IPF process and provide potential therapeutic targets for vascular remodeling.