Following nerve injury, disintegrated axonal mitochondria distal to the injury site release mitochondrial formylated peptides and DNA that can induce activation and inflammatory profiling of Schwann cells via formyl peptide receptor 2 (Fpr2) and toll-like receptor 9 (TLR9), respectively. We studied RT4 schwannoma cells to investigate the regulation of Fpr2 and TLR9 after stimulation with fMLF as a prototypical formylated peptide. RT4 cells were treated with fMLF at various concentrations and times with and without pretreatment with inhibitors (chloroquine for activated TLR9, PBP10 for Fpr2). Western blots of Fpr2, TLR9, p-p38, p-NFκB, and IL-6 were compared in relation to inflammatory profiling of RT4 cells and chemokine receptors (CCR2, CXCR4) as potential co-receptors of Fpr2. fMLF stimulation upregulated Fpr2 in RT4 cells at low concentrations (10 nM and 100 nM) but higher concentrations were required (10 µM and 50 µM) when the cells were pretreated with an activated TLR9 inhibitor. Moreover, the higher concentrations of fMLF could modulate TLR9 and inflammatory markers. Upregulation of Fpr2 triggered by 10 nM and 100 nM fMLF coincided with higher levels of chemokine receptors (CCR2, CXCR4) and PKCβ. Treating RT4 cells with fMLF, as an in vitro model of Schwann cells, uncovered Schwann cells' complex responses to molecular patterns of release from injured axonal mitochondria.

• Klíčová slova
• Wallerian degeneration, chemokines, cytokines, damage-associated molecular patterns, disintegration, mitochondria, receptors,
• MeSH
• chlorochin farmakologie   MeSH
• krysa rodu Rattus MeSH
• N-formylmethionin-leucyl-fenylalanin farmakologie   MeSH
• nádorové buněčné linie MeSH
• neurilemom metabolismus   patologie   MeSH
• receptory CCR2 genetika   metabolismus   MeSH
• receptory CXCR4 genetika   metabolismus   MeSH
• receptory pro formylované peptidy antagonisté a inhibitory   genetika   metabolismus   MeSH
• Schwannovy buňky cytologie   účinky léků   metabolismus   MeSH
• signální transdukce účinky léků   MeSH
• toll-like receptor 9 antagonisté a inhibitory   genetika   metabolismus   MeSH
• upregulace účinky léků   MeSH
• zánět metabolismus   patologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• chlorochin MeSH
• N-formylmethionin-leucyl-fenylalanin MeSH
• receptory CCR2 MeSH
• receptory CXCR4 MeSH
• receptory pro formylované peptidy MeSH
• toll-like receptor 9 MeSH

Inflammatory profiling of Schwann cells manifested as an upregulation of cytokines is present after traumatic or disease injury of the peripheral nerves. Inflammatory activation of Schwann cells via Toll-like receptors (TLRs) can be triggered by exogenous pathological molecules or endogenous ligands produced during Wallerian degeneration. We investigated the early period of inflammatory reactions by following the levels of TLR4, NFκB, IL-1β, pSTAT3, and IL-6 proteins after LPS treatment of RT4 schwannoma cells under in vitro conditions. Significantly increased levels of NFκB, IL-1β, pSTAT3, and IL-6 proteins were found 1 h after LPS action indicating their involvement in the initiation of the inflammatory reaction of schwannoma cells. This initiation was induced without increased TLR4 protein expression, but was accompanied by the appearance of TLR4 in early endosomes. The protein levels decreased within the next 6 h of treatment with a subsequent increase of NFκB, IL-1β, and pSTAT3 after 24 h of LPS treatment. In contrast, continuous decrease of IL-6 over time following LPS treatment was unexpected. Levels of soluble IL-6 protein in the culture medium also decreased with decreasing levels of LPS over 24 h.

• Klíčová slova
• Cytokines, Early endosomes, Schwann cells, Toll-like receptor 4, Transforming factors,
• MeSH
• krysa rodu Rattus MeSH
• ligandy MeSH
• lipopolysacharidy farmakologie   MeSH
• nádorové buňky kultivované MeSH
• neurilemom metabolismus   patologie   MeSH
• toll-like receptor 4 antagonisté a inhibitory   metabolismus   MeSH
• zánět metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• ligandy MeSH
• lipopolysacharidy MeSH
• Tlr4 protein, rat MeSH Prohlížeč
• toll-like receptor 4 MeSH