Reversing the PAI-1-induced fibrotic immune exclusion of solid tumor by multivalent CXCR4 antagonistic nano-permeator

A biomimetic targeted nanosystem delivering synergistic inhibitors for glioblastoma immune microenvironment reprogramming and treatment

Efficient drug delivery across the blood-brain barrier is imperative for treating glioblastoma (GBM). This study utilized the GBM cell membrane to construct a biomimetic targeted nanosystem (GMNPs@AMD/RAPA) that hierarchically releases the CXCR4 antagonist AMD3100 and the mTOR pathway inhibitor rapamycin (RAPA) for reprogramming the tumor immune microenvironment and suppressing the progression of GBM. By initially inhibiting the CXCL12/CXCR4 axis, the tumor microenvironment (TME) was reprogrammed to enhance the infiltration of cytotoxic T lymphocytes (CTLs) into the TME while suppressing tumor cell survival, proliferation, and angiogenesis. Subsequently, through further cellular uptake and degradation of the nanoparticles, the mTOR pathway inhibitor RAPA was released, further suppressing the tumor progression. This study successfully combined chemotherapy and immunotherapy, achieving effective synergistic therapeutic effects, and suppressing the progression of GBM.

Endothelial H2S-AMPK dysfunction upregulates the angiocrine factor PAI-1 and contributes to lung fibrosis

Dysfunction of the vascular angiocrine system is critically involved in regenerative defects and fibrosis of injured organs. Previous studies have identified various angiocrine factors and found that risk factors such as aging and metabolic disorders can disturb the vascular angiocrine system in fibrotic organs. One existing key gap is what sense the fibrotic risk to modulate the vascular angiocrine system in organ fibrosis. Here, using human and mouse data, we discovered that the metabolic pathway hydrogen sulfide (H2S)-AMP-activated protein kinase (AMPK) is a sensor of fibrotic stress and serves as a key mechanism upregulating the angiocrine factor plasminogen activator inhibitor-1 (PAI-1) in endothelial cells to participate in lung fibrosis. Activation of the metabolic sensor AMPK was inhibited in endothelial cells of fibrotic lungs, and AMPK inactivation was correlated with enriched fibrotic signature and reduced lung functions in humans. The inactivation of endothelial AMPK accelerated lung fibrosis in mice, while the activation of endothelial AMPK with metformin alleviated lung fibrosis. In fibrotic lungs, endothelial AMPK inactivation led to YAP activation and overexpression of the angiocrine factor PAI-1, which was positively correlated with the fibrotic signature in human fibrotic lungs and inhibition of PAI-1 with Tiplaxtinin mitigated lung fibrosis. Further study identified that the deficiency of the antioxidative gas metabolite H2S accounted for the inactivation of AMPK and activation of YAP-PAI-1 signaling in endothelial cells of fibrotic lungs. H2S deficiency was involved in human lung fibrosis and H2S supplement reversed mouse lung fibrosis in an endothelial AMPK-dependent manner. These findings provide new insight into the mechanism underlying the deregulation of the vascular angiocrine system in fibrotic organs.