Rhodococcus equi-Derived Extracellular Vesicles Promoting Inflammatory Response in Macrophage through TLR2-NF-κB/MAPK Pathways

Xu, Zhaokun; Hao, Xiujing; Li, Min; Luo, Haiwei

doi:10.3390/ijms23179742

Cited by 9 publications

(13 citation statements)

References 48 publications

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“…Nevertheless, Yang et al ( 31 ) reported that TSG-6 from bone marrow mesenchymal stem cells can protect against intervertebral disc degeneration via the TLR2/NF-κB signaling pathway. Moreover, TLR2 takes part in the inflammation response by activating the STAT3 and MAPK pathways ( 32 , 33 ). Additionally, Wu et al ( 34 ) showed that resveratrol blocks the IL-6/JAK/STAT3 pathway to protect HNPCs from degeneration.…”

Section: Discussionmentioning

confidence: 99%

S1PR3 suppresses the inflammatory response and extracellular matrix degradation in human nucleus pulposus cells

Tian,

Gao,

Xia

et al. 2024

Exp Ther Med

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Sphingosine 1-phosphate receptor 3 (S1PR3) participates in the inflammatory response in multiple types of diseases. However, the biological role of S1PR3 in intervertebral disc degeneration and the underlying mechanism are unclear. The aim of the present study was to investigate the functional role and the mechanism of S1PR3 in lipopolysaccharide (LPS)-induced human nucleus pulposus cells. The expression of S1PR3 and Toll-like receptor (TLR) 2 in LPS-induced nucleus pulposus (NP) cells was investigated using western blotting. The Cell Counting Kit-8 assay was used to detect cell proliferation, and the levels of inflammatory factors were detected using ELISA. Flow cytometry and western blotting were used for the assessment of apoptosis. The deposition of extracellular matrix (ECM) proteins was investigated using reverse transcription-quantitative PCR and western blotting. In addition, western blotting was used to investigate the protein expression levels of phosphorylated (p)-STAT3, STAT3, p-JNK, JNK, p-ERK, ERK, p-p38 and p38associated with STAT3 and MAPK signaling. S1PR3 expression was reduced, while TLR2 expression was elevated in LPS-induced human nucleus pulposus cells (HNPC). S1PR3 overexpression increased HNPC viability, inhibited the inflammatory response and suppressed apoptosis. Meanwhile, S1PR3 overexpression regulated the expression of ECM-related proteins. Additionally, overexpression of S1PR3 inhibited the expression of the TLR2-regulated STAT3 and MAPK pathways in LPS-induced HNPCs. Furthermore, TLR2 overexpression partially offset the impacts of S1PR3 overexpression on HNPC viability, apoptosis level, inflammation and as ECM degradation. In conclusion, STAT3 overexpression suppressed viability injury, the inflammatory response and the level of apoptosis and alleviated ECM protein deposition in HNPCs through the TLR2/STAT3 and TLR2/MAPK pathways, which may offer a promising candidate for the amelioration of intervertebral disc degeneration.

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Section: Discussionmentioning

confidence: 99%

S1PR3 suppresses the inflammatory response and extracellular matrix degradation in human nucleus pulposus cells

Tian,

Gao,

Xia

et al. 2024

Exp Ther Med

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“…E. faecalis (ATCC 29212 strain) was cultured in brain heart infusion broth at 37°C overnight under anaerobic conditions to the stationary phase. The isolation of E. faecalis EVs was conducted as previously described with some modifications (Xu et al 2022). For identification of the isolated EVs, transmission electron microscopy (TEM) and nanoparticle tracking analysis (NTA) were performed to identify the isolated E. faecalis EVs.…”

Section: Methodsmentioning

confidence: 99%

Enterococcus faecalis Extracellular Vesicles Promote Apical Periodontitis

Ma,

Deng,

et al. 2024

J Dent Res

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Enterococcus faecalis is an important contributor to the persistence of chronic apical periodontitis. However, the mechanism by which E. faecalis infection in the root canals and dentinal tubules affects periapical tissue remains unclear. Bacterial extracellular vesicles (EVs) act as natural carriers of microbe-associated molecular patterns (MAMPs) and have recently attracted considerable attention. In this study, we investigated the role of EVs derived from E. faecalis in the pathogenesis of apical periodontitis. We observed that E. faecalis EVs can induce inflammatory bone destruction in the periapical areas of mice. Double-labeling immunofluorescence indicated that M1 macrophage infiltration was increased by E. faecalis EVs in apical lesions. Moreover, in vitro experiments demonstrated the internalization of E. faecalis EVs into macrophages. Macrophages tended to polarize toward the M1 profile after treatment with E. faecalis EVs. Pattern recognition receptors (PRRs) can recognize MAMPs of bacterial EVs and, in turn, trigger inflammatory responses. Thus, we performed further mechanistic exploration, which showed that E. faecalis EVs considerably increased the expression of NOD2, a cytoplasmic PRR, and that inhibition of NOD2 markedly reduced macrophage M1 polarization induced by E. faecalis EVs. RIPK2 ubiquitination is a major downstream of NOD2. We also observed increased RIPK2 ubiquitination in macrophages treated with E. faecalis EVs, and E. faecalis EV-induced macrophage M1 polarization was notably alleviated by the RIPK2 ubiquitination inhibitor. Our study revealed the potential for EVs to be considered a virulence factor of E. faecalis and found that E. faecalis EVs can promote macrophage M1 polarization via NOD2/RIPK2 signaling. To our knowledge, this is the first report to investigate apical periodontitis development from the perspective of bacterial vesicles and demonstrate the role and mechanism of E. faecalis EVs in macrophage polarization. This study expands our understanding of the pathogenic mechanism of E. faecalis and provides novel insights into the pathogenesis of apical periodontitis.

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“…Many bacteria, including R. equi and M. tuberculosis, produce extra-cellular vesicles (EVs) of approximately 20-500 nm in diameter, that play an important role in pathogenesis and host-pathogen interaction [40][41][42]. R. equi encodes homologues of the dynamin-like proteins IniA (REQ_40370; 50% identity, 67% similarity) and IniC (REQ_40360; 55% identity, 67% similarity), which are required for EV synthesis in M. tuberculosis [43].…”

Section: Plos Onementioning

confidence: 99%

“…Proteomic analysis M. tuberculosis EVs revealed the presence of 287 cell surface, secreted and some cytoplasmic proteins [47]. R. equi EVs contain trypsin-susceptible VapA, strongly suggesting that VapA is located on the surface of these vesicles [42]. Based on this study we propose the hypothesis that cell surface localisation of VapA is at least in part mediated by its disordered N-terminal domain and serves to facilitate high local VapA concentrations and, in addition, faciliates incorporation in EVs that may play a role in R. equi pathogenesis.…”

Section: Plos Onementioning

confidence: 99%

The N-terminal domain is required for cell surface localisation of VapA, a member of the Vap family of Rhodococcus equi virulence proteins

Miranda-CasoLuengo,

Yerlikaya,

Luo

et al. 2024

PLoS ONE

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Rhodococcus equi pneumonia is an important cause of mortality in foals worldwide. Virulent equine isolates harbour an 80-85kb virulence plasmid encoding six virulence-associated proteins (Vaps). VapA, the main virulence factor of this intracellular pathogen, is known to be a cell surface protein that creates an intracellular niche for R. equi growth. In contrast, VapC, VapD and VapE are secreted into the intracellular milieu. Although these Vaps share very high degree of sequence identity in the C-terminal domain, the N-terminal domain (N-domain) of VapA is distinct. It has been proposed that this domain plays a role in VapA surface localization but no direct experimental data provides support to such hypothesis. In this work, we employed R. equi 103S harbouring an unmarked deletion of vapA (R. equi ΔvapA) as the genetic background to express C-terminal Strep-tagged Vap-derivatives integrated in the chromosome. The surface localization of these proteins was assessed by flow cytometry using the THE2122;-NWSHPQFEK Tag FITC-antibody. We show that VapA is the only cell surface Vap encoded in the virulence plasmid. We present compelling evidence for the role of the N-terminal domain of VapA on cell surface localization using fusion proteins in which the N-domain of VapD was exchanged with the N-terminus of VapA. Lastly, using an N-terminally Strep-tagged VapA, we found that the N-terminus of VapA is exposed to the extracellular environment. Given the lack of a lipobox in VapA and the exposure of the N-terminal Strep-tag, it is possible that VapA localization on the cell surface is mediated by interactions between the N-domain and components of the cell surface. We discuss the implications of this work on the light of the recent discovery that soluble recombinant VapA added to the extracellular medium functionally complement the loss of VapA.

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Rhodococcus equi-Derived Extracellular Vesicles Promoting Inflammatory Response in Macrophage through TLR2-NF-κB/MAPK Pathways

Cited by 9 publications

References 48 publications

S1PR3 suppresses the inflammatory response and extracellular matrix degradation in human nucleus pulposus cells

S1PR3 suppresses the inflammatory response and extracellular matrix degradation in human nucleus pulposus cells

Enterococcus faecalis Extracellular Vesicles Promote Apical Periodontitis

The N-terminal domain is required for cell surface localisation of VapA, a member of the Vap family of Rhodococcus equi virulence proteins

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