An inducible expression system for the manipulation of autophagic flux in vivo

Engineered Genetic Circuits Activated by Bezafibrate Improve ESC-Based TAA Cancer Vaccine Efficacy and PD-L1 Nanobody Therapy

Immunotherapy targeting tumor antigens and immune checkpoint inhibitors has garnered significant attention in cancer treatment. Synthetic gene circuits are developed, encoded in plasmids, which regulate the expression of tumor antigens shared with embryonic stem cells (ESCs) and PD-L1 nanobody (PD-L1 nb) in response to bezafibrate stimulation. This approach significantly minimizes side effects and improved therapeutic efficacy. The transcriptional switches leverage the interaction between the bezafibrate-responsive transcriptional activator PPARγ and RXRα, which are fused with the VPR/VP64/p65 activation domains (AD) and the Gal4 DNA-binding domain (DBD), respectively. These synthetic constructs are validated and their ability to modulate gene expression upon bezafibrate treatment are confirmed. Notably, the gene expression is precise and tunable in response to bezafibrate administration. HEK293T cells or ESCs are employed to deliver this gene circuit, or the plasmids containing the circuit into the tumor are directly injected. Administration of bezafibrate reduces tumor growth, increases specific CD8+ T cells, and mitigates CD8+ T cell exhaustion, underscoring the feasibility and effectiveness of the approach. ESC-based and intratumoral delivery of the synthetic gene circuits and cargo genes, particularly PD-L1 nb, significantly inhibit tumor growth. PD-L1 nb effectively blocks PD-L1 expression both in vitro and in vivo, as confirmed by using a mutant PD-L1 nb sequence.

maresin2 fine-tunes ULK1 O-GlcNAcylation to improve post myocardial infarction remodeling

BACKGROUND

Myocardial infarction (MI) is one of the common causes of hospitalization and death all over the world. Maresin2 (MaR2), a specialized pro-solving mediator of inflammation, has been consolidated to be a novel cytokine fine-tuning inflammatory cascade. However, the precise mechanism is still unknown. Here, we demonstrated that maresin2 relieved myocardial damage via ULK1 O-GlcNAc modification during MI.

METHODS

The myocardial infarction model was established by ligating the left anterior descending artery (LAD). Echocardiography, histopathology, transmission electron microscope, and Western blot were used to evaluate cardiac function and remodeling. Furthermore, primary neonatal rat cardiomyocytes (NRCMs) were cultivated, and immunoprecipitation (IP) assays were performed to explore the specific mechanism.

RESULTS

As suggested, maresin2 treatment protected cardiac function and ameliorated adverse cardiac remodeling. Furthermore, we found that maresin2 facilitated autophagy and inhibited apoptosis under the modulation of O-GlcNAcylation-dependent ULK1 activation. Meanwhile, we discovered that maresin2 treatment ameliorated the inflammation of myocardial cells by inhibiting the interaction of TAK1 and TAB1.

CONCLUSIONS

Maresin2 is likely to promote autophagy while relieving apoptosis and inflammation of myocardial cells, thereby exerting a protective effect on the heart after MI.