Added “TLR4 (Toll-Like Receptor 4)”: Toll-like receptor 4 (TLR4) is a cell-surface pattern-recognition receptor in the toll like receptors family. It is best known for detecting particular forms of bacterial lipopolysaccharide (LPS)…
Added “TLR4 (Toll-Like Receptor 4)”: Toll-like receptor 4 (TLR4) is a cell-surface pattern-recognition receptor in the toll like receptors family. It is best known for detecting particular forms of bacterial lipopolysaccharide (LPS)… Added “What TLR4 Senses”: LPS is a component of the outer membrane of Gram-negative bacteria, but LPS molecules are not immunologically interchangeable. Their structures vary among organisms and can produce different signaling… Added “Signaling Outputs”: TLR4 activation can engage MyD88-linked signaling and NF-kB, increasing transcription of inflammatory mediators. Depending on the cell, ligand, exposure pattern, and experimental system, downstream… Added “Barrier and Tissue Contexts”: In necrotizing enterocolitis (NEC), a narrative review describes high TLR4 expression in the premature intestinal epithelium and links LPS-responsive signaling to epithelial injury, impaired repair,… Added “Disease-Associated Pathways”: In endometriosis research, a review synthesizing the authors’ clinical and laboratory program reports higher LPS in menstrual or peritoneal samples and LPS-responsive cytokine production. Anti-TLR4… Added “Metals Beyond Direct Nickel Sensing”: Other metal studies can implicate a TLR4-associated pathway without showing that the metal binds TLR4. In a streptozotocin diabetic-mouse model, cadmium exposure was accompanied by renal TLR4/NF-kB… Added “What Intervention Studies Establish”: In a mouse cardiac-arrest model with cultured-cell experiments, sodium butyrate changed TLR4, MyD88, phosphorylated NF-kB, microglial markers, gut measures, and neurological outcomes. The study… Added “Reading the Evidence”: When a WikiBiome article invokes TLR4, four questions help calibrate the claim: 1. Was the evidence a ligand measurement, receptor-expression result, downstream pathway marker, or direct perturbation?… Added “Connections”: - endotoxemia — circulation of microbial products is one exposure context in which TLR4 is often discussed - systemic inflammation — a possible downstream state, not a synonym for receptor activation… Removed “Overview”: Toll-like receptor 4 (TLR4) is the primary innate immune sensor for bacterial lipopolysaccharide (LPS) -- the endotoxin coating the outer membrane of all Gram-negative bacteria. TLR4 activation… Removed “Signaling Cascade”: LPS (from Gram-negative bacteria) │ └─→ LBP → CD14 → MD-2/TLR4 complex │ ┌────────┴────────┐ │ │ MyD88-dependent TRIF-dependent │ │ NF-kB activation IRF3 activation │ │ TNF-alpha, IL-1beta IFN-beta… Removed “Nickel: Direct TLR4 Activation (Human-Specific)”: Nickel directly activates TLR4 on dendritic cells -- a mechanism that is human-specific because it depends on histidine residues (H456 and H458) in human TLR4 that are absent in mouse TLR4. This… Removed “Cadmium: TLR4/NF-kB Aggravation”: Cadmium aggravates diabetic nephropathy through the TLR4/NF-kB pathway. Zinc + curcumin intervention attenuates this Cd-TLR4 signaling. Removed “Necrotizing Enterocolitis”: TLR4 is the master regulator of NEC. The premature intestine over-expresses TLR4, creating hypersensitivity to luminal LPS. TLR4 activation in the neonatal gut: - Triggers epithelial apoptosis and… Removed “Endometriosis (bacterial contamination hypothesis)”: LPS/TLR4/NF-kB cascade in endometriotic tissue drives HGF, VEGF, and inflammatory cytokine production. Anti-TLR4 antibody blocked LPS-stimulated endometriotic cell proliferation, confirming functional… Removed “Colorectal Cancer”: fusobacterium nucleatum promotes tumorigenesis via miR21/TLR4/NF-kB signaling. Removed “Neurodegeneration”: alpha synuclein aggregates activate microglia through TLR4, driving neuroinflammation in parkinsons disease. Removed “Type 1 Diabetes”: bacteroides fragilis dorei produces TLR4-antagonist LPS that is immunoinhibitory -- preventing immune education and potentially contributing to autoimmune risk. Removed “Suppressors”: | Agent | Mechanism | Source | |-------|-----------|--------| | butyrate | Suppresses TLR4/MyD88/NF-kB pathway | | | BHB (ketone body) | Directly inhibits TLR4 signaling | Ketogenic diet studies | |… Removed “Activators”: | Agent | Mechanism | |-------|-----------| | LPS (Gram-negative) | Canonical TLR4 ligand | | Nickel (Ni2+) | Direct binding to H456/H458 (human-specific) | | Cadmium (Cd2+) | TLR4/NF-kB aggravation |… Removed “Cross-References”: - proteobacteria -- Primary LPS source in the dysbiotic gut - bacterial contamination hypothesis -- LPS/TLR4 in endometriosis - nickel -- Human-specific TLR4 activation - cadmium -- Cd-TLR4/NF-kB in… Removed citations from “Nickel: Direct TLR4 Activation (Human-Specific)”: ahlstrom 2019 nickel allergy review. Removed citations from “Cadmium: TLR4/NF-kB Aggravation”: sun 2024 zinc curcumin cadmium diabetic nephropathy. Removed citations from “Necrotizing Enterocolitis”: sampah 2021 prenatal immunity nec. Removed citations from “Endometriosis (bacterial contamination hypothesis)”: khan 2018 bacterial contamination hypothesis endometriosis. Removed citations from “Colorectal Cancer”: appunni 2021 dietary factors gut microbiome crc. Removed citations from “Type 1 Diabetes”: davis richardson 2015 bacteroides dorei t1d model. Removed citations from “Suppressors”: sun 2025 sodium butyrate neuroinflammation cardiac arrest; khan 2018 bacterial contamination hypothesis endometriosis; sun 2024 zinc curcumin cadmium diabetic nephropathy. Added citations to “TLR4 (Toll-Like Receptor 4)”: davis richardson 2015 bacteroides dorei t1d model; ahlstrom 2019 nickel allergy review. Added citations to “What TLR4 Senses”: davis richardson 2015 bacteroides dorei t1d model; ahlstrom 2019 nickel allergy review. Added citations to “Signaling Outputs”: rekatsina 2020 microbiota nsaid enteropathy probiotics review. Added citations to “Barrier and Tissue Contexts”: sampah 2021 prenatal immunity nec; rekatsina 2020 microbiota nsaid enteropathy probiotics review. Added citations to “Disease-Associated Pathways”: khan 2018 bacterial contamination hypothesis endometriosis; appunni 2021 dietary factors gut microbiome crc; perez pardo 2022 toll like receptors parkinsons microbiome gut brain. Added citations to “Metals Beyond Direct Nickel Sensing”: sun 2024 zinc curcumin cadmium diabetic nephropathy. Added citations to “What Intervention Studies Establish”: sun 2025 sodium butyrate neuroinflammation cardiac arrest. Added references: perez-pardo-2022-toll-like-receptors-parkinsons-microbiome-gut-brain.
wiki/concepts/tlr4.md