Gambogic acid protects LPS-induced apoptosis and inflammation in a cell model of neonatal pneumonia through the regulation of TrkA/Akt signaling pathway

Xu Gao,Guifang Li,Xinya Dai,Jingya Dai

doi:10.1186/s40360-021-00496-9

Xu Gao, Guifang Li + Show 2 more

Open Access

https://doi.org/10.1186/s40360-021-00496-9

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Abstract

ObjectiveIn this work, we investigated the effects of gambogic acid (GA) on lipopolysaccharide (LPS)-induced apoptosis and inflammation in a cell model of neonatal pneumonia.MethodHuman WI-38 cells were maintained in vitro and incubated with various concentrations of GA to examine WI-38 survival. GA-preincubated WI-38 cells were then treated with LPS to investigate the protective effects of GA on LPS-induced death, apoptosis and inflammation. Western blot assay was utilized to analyze the effect of GA on tropomyosin receptor kinase A (TrkA) signaling pathway in LPS-treated WI-38 cells. In addition, human AKT serine/threonine kinase 1 (Akt) gene was knocked down in WI-38 cells to further investigate the associated genetic mechanisms of GA in protecting LPS-induced inflammation and apoptosis.ResultsPre-incubating WI-38 cells with low and medium concentrations GA protected LPS-induced cell death, apoptosis and inflammatory protein productions of IL-6 and MCP-1. Using western blot assay, it was demonstrated that GA promoted TrkA phosphorylation and Akt activation in LPS-treated WI-38 cells. Knocking down Akt gene in WI-38 cells showed that GA-associated protections against LPS-induced apoptosis and inflammation were significantly reduced.ConclusionsGA protected LPS-induced apoptosis and inflammation, possibly through the activations of TrkA and Akt signaling pathway. This work may broaden our understanding on the molecular mechanisms of human neonatal pneumonia.

Highlights

Neonatal pneumonia is a serious respiratory infectious disease often occurring in neonate patients with high risk of morbidity and mortality [1, 2]
This work may broaden our understanding on the molecular mechanisms of human neonatal pneumonia
After WI-38 cells were incubated with gambogic acid (GA) for 24 h, they were treated with 10 mg/ml lipopolysaccharide (LPS) for 24 h

Summary

Results

GA protected LPS-induced WI-38 cell death WI-38 cells were cultured in vitro and incubated with Gambogic acid (GA) at various concentrations for. The effect of GA on LPS-induced inflammatory injury was characterized by western blot assay It showed, under control condition, little or none IL-6 or MCP-1 protein was produced in WI-38 cells (Fig. 2c,Ctrl). Quantification on western blot densitometry confirmed this finding, demonstrating that Akt downregulation reversed the reducing effect of GA preincubation on LPS-induced inflammatory protein productions (IL-6 and MCP-1) in WI-38 cells (Fig. 4 f, * P < 0.05). We investigated the effects of GA on LPS-induced apoptosis and inflammation in WI-38 cells The results from both TUNEL assay and western blot assay demonstrated that, GA significantly reduced apoptosis and inflammatory protein biomarkers in LPS-injured WI-38 cells. Further studies are needed to explore whether other signaling pathways, such as those down-streaming to NF-kappaB, or those associated with bone formation/development, may be interacted with TrkA/Akt signaling pathway to regulate GAassociated protection against cellular injury in neonatal pneumonia

Conclusions

Introduction

Materials and methods

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