# Rus-GXF, a ruscogenin glycoside, binds to the ADP-binding domain of JAK1 to prevent inflammation and barrier damage in acute lung injury

## TL;DR

Rus-GXF, a natural compound, reduces lung inflammation and damage by inhibiting the JAK1/STAT3 pathway in acute lung injury.

## Contribution

Rus-GXF is identified as a novel JAK1 allosteric inhibitor with therapeutic potential for acute lung injury.

## Key findings

- Rus-GXF reduces inflammation and improves barrier function in immune and epithelial cells.
- Rus-GXF inhibits JAK1 activation and STAT3 phosphorylation in acute lung injury models.
- Rus-GXF alleviates ALI severity in mice by suppressing cytokine storms and histopathological damage.

## Abstract

Ruscogenin-1-O-[β-D-glucopyranosyl (1→2)][β-D-xylopyranosyl (1→3)] -β-D-fucopyranoside (Rus-GXF) is a ruscogenin glycoside of Liriope muscari (Decaisne) L. H. Bailey, yet its protective effects against acute lung injury—a condition characterized by exacerbated inflammation and barrier damage have not been fully elucidated.

In this study, the preventive and therapeutic effects of Rus-GXF on acute lung injury (ALI) were investigated using transcriptome RNA sequencing, network pharmacology, molecular docking, molecular dynamics simulation and other in vitro and in vivo experiments.

Rus-GXF suppressed inflammatory responses in two key cell types involved in lung injury. In immune cells (RAW264.7), it inhibited the production of pivotal pro-inflammatory mediators and their regulatory genes. Similarly, in pulmonary epithelial cells (BEAS-2B), it reduced the expression of inflammatory signals and concurrently enhanced markers of cellular tight junction proteins. In mice, Rus-GXF alleviated ALI severity, evidenced by decreased lung wet/dry ratio, bronchoalveolar lavage fluid protein content, pro-inflammatory cytokine levels, and histopathological scores. Integrated network pharmacology and transcriptomics indicated that Rus-GXF acts through multi-target mechanisms in ALI. Molecular docking and dynamics simulations revealed that Rus-GXF acts as an allosteric inhibitor of JAK1, thereby preventing its activation and subsequent STAT3 phosphorylation. The inhibitory effect of Rus-GXF on the JAK1/STAT3 signaling pathway was investigated by immunohistochemistry (IHC) and Western blot analysis (WB).

These results demonstrate that Rus-GXF suppresses the macrophage-derived cytokine storm, alleviates inflammation, and improves barrier function. It functions as a JAK1 inhibitor to regulate ALI progression via the JAK1/STAT3 signaling pathway.