Heterogeneous Porphyromonas gingivalis LPS modulates immuno-inflammatory response, antioxidant defense and cytoskeletal dynamics in human gingival fibroblasts.

Thanuja D K Herath,Richard P Darveau,Chaminda J Seneviratne,Cun-Yu Wang,Yu Wang,Lijian Jin

doi:10.1038/srep29829

Abstract

Periodontal (gum) disease is a highly prevalent infection and inflammation accounting for the majority of tooth loss in adult population worldwide. Porphyromonas gingivalis is a keystone periodontal pathogen and its lipopolysaccharide (PgLPS) acts as a major virulence attribute to the disease. Herein, we deciphered the overall host response of human gingival fibroblasts (HGFs) to two featured isoforms of tetra-acylated PgLPS1435/1449 and penta-acylated PgLPS1690 with reference to E. coli LPS through quantitative proteomics. This study unraveled differentially expressed novel biomarkers of immuno-inflammatory response, antioxidant defense and cytoskeletal dynamics in HGFs. PgLPS1690 greatly upregulated inflammatory proteins (e.g. cyclophilin, inducible nitric oxide synthase, annexins, galectin, cathepsins and heat shock proteins), whereas the anti-inflammatory proteins (e.g. Annexin A2 and Annexin A6) were significantly upregulated by PgLPS1435/1449. Interestingly, the antioxidants proteins such as mitochondrial manganese-containing superoxide dismutase and peroxiredoxin 5 were only upregulated by PgLPS1690. The cytoskeletal rearrangement-related proteins like myosin were differentially regulated by these PgLPS isoforms. The present study gives new insight into the biological properties of P. gingivalis LPS lipid A moiety that could critically modulate immuno-inflammatory response, antioxidant defense and cytoskeletal dynamics in HGFs, and thereby enhances our understanding of periodontal pathogenesis.

Highlights

P. gingivalis LPS lipid A structure is one of the most extensively studied molecular structures among oral bacteria due to its remarkable heterogeneity[2,3,4,6,7,8,9,10,11]
The study groups consisted of cellular samples without LPS stimulation as the controls, and those treated with PgLPS1435/1449, PgLPS1690 and hexa-acylated E. coli LPS
Proteins included in the antioxidant defense category such as Mn-superoxide dismutase (MnSOD/SOD2) (3.1 folds), human SH3 binding glutamic rich protein (SH3BGRL) (2.2 folds), nitric oxide synthate 2A (NOS2A) (2.6 folds) and peroxiredoxin[1] (PRDX1) (4.2 folds) were upregulated in PgLPS1690-treated cells as compared to the control

Summary

Introduction

P. gingivalis LPS lipid A structure is one of the most extensively studied molecular structures among oral bacteria due to its remarkable heterogeneity[2,3,4,6,7,8,9,10,11]. Considering the foregoing knowledge gap, the present study investigated the host response of HGFs (the predominant cell type in gingival tissues) to the two featured isoforms of P. gingivalis LPS1690 and LPS1435/1449 with reference to the hexa-acylated E. coli LPS. In this comprehensive study, we determined both cell-bound and secretory proteomic expression profiles of HGFs using gel- and mass spectrometry-based quantitative proteomic approaches, and the identified novel biomarkers were further validated by various molecular techniques. Differential expression in the key biomarkers of immuno-inflammatory response and cytoskeletal rearrangement in HGFs in response to PgLPS isoforms may critically account for periodontal pathogenesis

Methods

Results

Conclusion