Mycoplasma genitalium-derived lipid-associated membrane proteins induce activation of MAPKs, NF-κB and AP-1 in THP-1 cells

Abstract

Mycoplasma genitalium lipid-associated membrane proteins (LAMPg) can induce human monocytic cell line THP-1 to produce proinflammatory cytokines, including tumor necrosis factor-alpha (TNF-alpha), IL-1beta and IL-6, as demonstrated by an enzyme-linked immunosorbent assay and reverse transcription-PCR (RT-PCR). This study also investigated the signaling transduction pathways involved in the production of these cytokines. THP-1 cells were stimulated with LAMPg and then examined for the activation of MAPKs, such as SAPK/JNK, p38, extracellular signal-regulated kinase (ERK)1/2 and NF-kappaB and AP-1. Western blot clearly showed that stress-activated protein kinase (SAPK)/c-Jun-N-terminal kinase (JNK), p38 and ERK1/2 were activated in response to LAMPg, peaking at 30 min. SAPK/JNK-specific inhibitor SP600125 slightly suppressed IL-6 production although no evident effects were obtained for TNF-alpha and IL-1beta; ERK1/2 inhibitor PD98059 blocked both TNF-alpha and IL-1beta, but not IL-6 production. However, p38 inhibitor SB203580 abrogated TNF-alpha, IL-1beta and IL-6 production. The DNA-binding activity of NF-kappaB and AP-1 was also assessed by an electrophoretic mobility gel shift assay, and an NF-kappaB specific inhibitor, pyrrolidine dithiocarbamate, profoundly inhibited the synthesis and production of the proinflammatory cytokines. Based on these results, this study concludes that MAPKs, NF-kappaB and AP-1 may play important roles in the genital tract inflammatory reaction after mycoplasma infection.

Mycoplasma genitalium -Encoded MG309 Activates NF-κB via Toll-Like Receptors 2 and 6 To Elicit Proinflammatory Cytokine Secretion from Human Genital Epithelial Cells

“…Like other Mollicutes, M. genitalium contains a significant proportion of lipoproteins in the cell membrane (45), consistent with the identification of 21 putative lipoprotein genes in the 580-kb genome (15). It has been shown recently that Triton X-114 preparations of detergent-soluble components from M. genitalium upregulate transcription of tumor necrosis factor alpha, interleukin-1␤ (IL-1␤), and IL-6 mRNA in the human THP-1 monocytic cell line (46,47), suggesting that lipoproteins may, at least in part, be responsible for immune activation. Of the 21 putative lipoprotein genes, we selected MG309 for inflammatory characterization because it is expressed during M. genitalium infection and is recognized by sera of M. genitalium patients, suggesting immune recognition by the host (L. Ma and D. H. Martin, unpublished findings).…”

Up-Regulation of miR-130b-3p Activates the PTEN/PI3K/AKT/NF-κB Pathway to Defense against Mycoplasma gallisepticum (HS Strain) Infection of Chicken

“…NF-κB is known to be an important nuclear transcription factor, and plays a predominant role in cell innate immune system [56,57,58]. It has been reported to play central roles in inflammatory response to mycoplasma invasion [4,59,60]. For instance, MG -derived LAMPs significantly up-regulated IL-1β, IL-6, and IL-8 levels in chicken tracheal epithelial cells through activating the NF-κB pathway [4].…”

Effects of Ureaplasma urealyticum lipid-associated membrane proteins on rheumatoid arthritis synovial fibroblasts

“…Preparation of LAMPs and the aqueous phase (used as a control) followed the methods described by You et al 8 Briefly, U. urealyticum was cultured in 500 ml of medium to the stationary phase. After centrifugation (10 000 g for 10 min at 4 C), pellets were resuspended in 5 ml of Trisbuffered saline (TBS, 50 mM Tris-Cl, pH 8.0, 0.15 M NaCl) containing 1 mM ethylenediaminetetra-acetic acid (EDTA) (TBSE).…”