Eugenol modulates the NOD1-NF-κB signaling pathway via targeting NF-κB protein in triple-negative breast cancer cells.

Background: The most aggressive subtype of breast cancer, triple-negative breast cancer (TNBC), has a worse prognosis and a higher probability of relapse since there is a narrow range of treatment options. Identifying and testing potential therapeutic targets for the treatment of TNBC is of high priority. Methods: Using a transcriptional signature of triple-negative breast cancer collected from Gene Expression Omnibus (GEO), CMap was utilized to reposition compounds for the treatment of TNBC. CCK8 and colony formation experiments were performed to detect the effect of the candidate drug on the proliferation of TNBC cells. Meanwhile, transwell and wound healing assay were implemented to detect cell metastasis change caused by the candidate drug. Moreover, the proteomic approach was presently ongoing to evaluate the underlying mechanism of the candidate drug in TNBC. Furthermore, drug affinity responsive target stability (DARTS) coupled with LC-MS/MS was carried out to explore the potential drug target candidate in TNBC cells. Results: We found that the most widely used medication, eugenol, reduced the growth and metastasis of TNBC cells. According to the underlying mechanism revealed by proteomics, eugenol could inhibit TNBC cell proliferation and metastasis via the NOD1-NF-κB signaling pathway. DARTS experiment further revealed that eugenol may bind to NF-κB in TNBC cells. Concludes: Our findings pointed out that eugenol was a potential candidate drug for the treatment of TNBC.

Localization and gene expression of human beta-defensin 9 at the human ocular surface epithelium.

PURPOSE: Antimicrobial peptides (AMPs) are multifunctional host defense molecules. Human beta-defensin 9 (HBD9) has previously been shown to be downregulated during ocular surface (OS) infection or inflammation. Here, the authors aimed to study localization of HBD9 protein in different OS regions and to determine the role of Toll-like receptors (TLRs), nucleotide oligomerization domain (NOD)-like receptors, and proinflammatory cytokines in HBD9 expression. METHODS: Immunolocalization of HBD9 protein was carried out on the normal human OS regions (cornea, limbus, and conjunctiva). Quantitative PCR analysis of HBD9 mRNA was performed in SV40-transformed human corneal epithelial cells (hCECs) treated for different durations with synthetic pathogen-associated molecular patterns (PAMPs) and recombinant cytokines. RESULTS: HBD9 protein was constitutively expressed on OS epithelia. Corneal and limbal epithelia and corneal stroma demonstrated modest levels of HBD9, whereas conjunctival epithelium demonstrated high levels of HBD9 protein. TLR02, TLR03, TLR04, and TLR05 were shown to modulate HBD9 mRNA in hCECs. Similarly, NOD2 and IL-1beta were also shown to alter HBD9 in a time-dependent manner. In response to infection-related PAMPs and inflammatory cytokines, an initial increase in HBD9 mRNA levels was observed, followed by a significant downregulation. CONCLUSIONS: This is the first demonstration of HBD9 protein expression at different OS regions. The authors also determined the role of various innate immune receptors in HBD9 mRNA modulation. Further understanding of the signaling mechanisms involved in the initial response of HBD9 to infection or inflammation is likely to indicate future therapeutic directions with this AMP.

Enhanced induction of a histamine-forming enzyme, histidine decarboxylase, in mice primed with NOD1 or NOD2 ligand in response to various Toll-like receptor agonists.

We investigated the immunopharmacological aspects of innate immune responses via Toll-like receptors (TLRs), NOD1 and NOD2, in terms of induction of the histamine-forming enzyme, histidine decarboxylase (HDC), activity in mice. Intravenous injection of TLR4-agonistic synthetic lipid A definitely induced HDC activity in the liver, spleen, and lungs, especially the lungs, in mice, where maximum activity was induced about 3 h after the injection of lipid A. The TLR2/6 agonistic synthetic diacyl-type lipopeptide FSL-1 and TLR3-agonistic poly I:C were also effective in inducing HDC, while the NOD2-agonistic synthetic muramyldipeptide (MDP) and NOD1-agonistic synthetic FK156 and FK565 exhibited only weak activities in this respect. Mice primed with intravenous injection of NOD1 or NOD2 agonists produced higher HDC activity following the 4-6 h later intravenous challenge with the above TLR agonists. Among the priming agents, FK565 exhibited the strongest activity, and it was effective via various administration routes - intraperitoneal, subcutaneous, intramuscular, as well as intravenous injection; furthermore, oral (gastric) administration was effective, although it needed a dose 10 times higher than that required for other administration routes. These findings suggest that HDC is induced in association with TLRs and NOD1/2, and that the newly formed histamine by the induced HDC might play important roles in the regulation of inflammatory and immune responses in various organs.