Antibacterial peptides inhibit MC3T3-E1 cells apoptosis induced by TNF-α through p38 MAPK pathway

Abstract

Background: Antimicrobial peptides (AMP), as a small molecular polypeptide with a broad antibacterial spectrum and high efficiency, have attracted more and more attention. Few pieces of research on the effect of the antimicrobial peptide on osteoblast under inflammatory conditions have so far been reported. The main aim of this work was to investigate the antiapoptosis effect of the antimicrobial peptide on MC3T3-E1 cells induced by TNF-α and its related mechanism.Methods: Rat MC3T3-E1 cells were co-cultured with different concentrations of antibacterial peptide DP7 and TNF-α.MTS assay, cell scratch test, alkaline phosphatase activity, and alizarin red staining assay were used to determine osteoblast viability in this experiment. Annexin V-FITC/PI double staining cells and flow cytometry were used to analyze apoptosis and Western blot assay detection to show mitogen-activated protein kinase (MAPK) protein expression in rat MC3T3-E1 cells. Then, Realtime polymerase chain reaction (PCR) was used to examine the caspase-3 gene expression. Also, ELISA detection was used to clarify the anti-apoptotic effect of the p38 MAPK inhibitor, SB203580, on cells' apoptosis.Results: Antimicrobial peptide could promote the proliferation, migration, and osteogenic ability of MC3T3-E1 cells induced by TNF-α, but inhibit cell apoptosis rate (P<0.05), and the effect was concentration-dependent. Western blot results showed after TNF-αtreatment, the expression of p-p38 MAPK in the MC3T3-E1 cells increased after TNF-α and antimicrobial peptide cotreatment, TNF-α induced p-p38 MAPK phosphorylation was inhibited, and the difference was statistically significant (P<0.05).Realtime PCR results showed that the gene expression of caspase-3 mRNA was up-regulated after TNF-α treatment, while their expression was down-regulated after cultured with TNF-α and antimicrobial peptide.Elisa's analysis showed that cell apoptosis increased after TNF-α treatment alone, and cell apoptosis was reduced to the normal levels when combined with antimicrobial peptide, and cell apoptosis induced by TNF-α was partially abolished when combined with SB203580.Conclusions: Antimicrobial peptide DP7 could inhibit MC3T3-E1 cells apoptosis induced by TNF-α, and the effect was concentration-dependent. The antiapoptosis activation of the antimicrobial peptide on MC3TE-E1 cells may be related to the inhibition of the p38 MAPK pathway.

Nanoarchitectonics of Bimetallic Cu-/Co-Doped Nitrogen–Carbon Nanozyme-Functionalized Hydrogel with NIR-Responsive Phototherapy for Synergistic Mitigation of Drug-Resistant Bacterial Infections

“…To assess the degree of inflammation at the wound site, the concentration of interleukin 10 (IL-10) and tumor necrosis factor α (TNF-α) were estimated by immunohistochemistry. 57,58 Consistent with the results of wound healing and H&E S16). The body weight of mice in different groups increases gradually with a trend similar to that of the PBStreated group (Figure 13d), further implying the negligible toxicity of our prepared nanomaterials.…”

“…The MRSA-infected wounds treated with CuCo/NC-HG+H 2 O 2 +NIR and CuCo/NC-HG (2 MIC)+NIR, respectively, have morphologically normal and tightly packed squamous epithelial cells with a structurally intact epidermis and an abundance of dermal collagen fibers. To assess the degree of inflammation at the wound site, the concentration of interleukin 10 (IL-10) and tumor necrosis factor α (TNF-α) were estimated by immunohistochemistry. , Consistent with the results of wound healing and H&E staining, the treatment of wounds based on CuCo/NC-HG shows the highest concentration of IL-10 and the lowest that of TNF-α (Figure b,c), suggesting that CuCo/NC-HG can efficiently suppress bacterial infections and promote wound healing without inflammation and tissue adhesions. Apart from that, the histological H&E staining analysis results of heart, liver, spleen, lung, and kidney of mice on day 7 indicate that CuCo/NC and CuCo/NC-HG have good biocompatibility in vivo (Figure S16).…”

Influence of tumor necrosis factor-alpha (TNF-&alpha;) in differentiation and mineralization of osteoblast-like and dental pulp cells

“…Similar to what happens with DPSCs, low concentrations of TNF-α (0.1 -1 ng/mL) promote mineralization and osteogenic differentiation of MC3T3 cells while concentrations from 10 ng/mL up promote inhibition (Huang et al, 2014;Wang et al, 2017;Chen et al, 2019b;Lu et al, 2020). In our study we stimulated cells with 10 ng/mL of TNF-α and no significant formation of biomineralization nodules were observed.…”

“…When proliferation was evaluated, preosteoblasts did not present a significant cell number increase. A recent study which used the same type of cells under stimuli of 50 ng/mL TNF-α also observed migration ability of these cells with complete closure of wound after 48 hours, and no proliferation of treated cells when compared to the control group (Lu et al, 2020).…”

Microbial resistance to nanotechnologies: An important but understudied consideration using antimicrobial nanotechnologies in orthopaedic implants

“…Such unintended consequence might be an additional consideration when deploying AMP-based aseptic strategies. Although many have reported that AMPs is relatively harmless to bone cells and no observable adverse effects on bone growth and local immune functions in vitro [ [168] , [169] , [170] ], the clinical relevance of these in vitro findings remains to be seen. As the cytotoxicity to bone cells and nearby immune cells is a critical contributor to orthopaedic implant associated microbial resistance, future studies are necessary to fully elucidate the toxicological profile of AMPs especially in a more physiologically relevant condition.…”