MCP Server Proto-OKN

# PFOA ToxCast Analysis - Chat Transcript ## Query 1: > Which biological targets does perfluorooctanoic acid (PFOA) interact with? ### Analysis Process I searched the ToxCast database (biobricks-toxcast knowledge graph) to identify all biological targets that PFOA has been tested against. ### Database Information - **Chemical Identified**: Perfluorooctanoic acid (DTXSID8031865) - **Total Assays**: 1,396 different assays - **Data Source**: EPA ToxCast InvitroDB ### Biological Targets and Pathways #### Nuclear Receptors - **Androgen Receptor (AR)** - agonist and antagonist activities - **Estrogen Receptors (ERα, ERβ)** - multiple assays in human and various species - **Peroxisome Proliferator-Activated Receptors (PPARα, PPARγ, PPARδ)** - **Thyroid Hormone Receptors (TRα, TRβ)** - **Glucocorticoid Receptor (GR)** - **Progesterone Receptor (PR)** - **Retinoic Acid Receptors (RARα, RARβ, RARγ)** - **Retinoid X Receptors (RXRα, RXRβ)** - **Liver X Receptors (LXRα, LXRβ)** - **Farnesoid X Receptor (FXR)** - **Vitamin D Receptor (VDR)** - **Constitutive Androstane Receptor (CAR)** - **Pregnane X Receptor (PXR)** - **Estrogen-Related Receptors (ERRα, ERRγ)** #### Transcription Factors & Signaling Pathways - **Aryl Hydrocarbon Receptor (AhR)** - **p53 tumor suppressor** - **NF-κB (nuclear factor kappa B)** - **AP-1 (activator protein 1)** - **STAT3** - **HIF-1α (hypoxia-inducible factor)** - **Nrf2/ARE (antioxidant response element)** #### Metabolic Enzymes - **Cytochrome P450 enzymes**: CYP1A1, CYP1A2, CYP2B6, CYP2C9, CYP2C19, CYP2C8, CYP2E1, CYP3A4, CYP3A5, CYP3A7, CYP4A11, CYP7A1, CYP19A1 - **UDP-glucuronosyltransferases**: UGT1A1, UGT1A6 - **Sulfotransferases**: SULT2A1 - **Glutathione S-transferases**: GSTA2, GSTM3 #### Transporters - **ABC transporters**: ABCB1/P-glycoprotein, ABCB11, ABCC2, ABCC3, ABCG2 - **Organic anion transporters**: SLCO1B1/OATP1B1, SLC22A1 #### Cell Signaling & Kinases - Multiple protein kinases (AKT1, AKT2, GSK3β, PI3Kα, protein kinase A, various MAPKs) - Protein phosphatases (PPP1CA, PPP2CA, PTEN, PTPN1, PTPN2, etc.) #### Inflammatory & Immune Markers - Cytokines and chemokines (IL-6, IL-8, IL-1α, TNFα, MCP-1, MIG, etc.) - Adhesion molecules (ICAM-1, VCAM-1, E-selectin) - Matrix metalloproteinases (MMP1, MMP3, MMP9, MMP10) #### Cellular Stress & Toxicity Markers - Cell viability and cytotoxicity - Apoptosis markers (caspases, BAX, BCL2) - DNA damage (H2AX phosphorylation) - Mitochondrial function - Oxidative stress markers --- ## Query 2: > Which of these assays have a positive result? ### Results Summary **147 out of 1,396 assays showed positive results** (hitcall = 1.0) ### Key Positive Findings by Category #### 1. Estrogen Receptor Activity (Strong Signal) **ERα (Estrogen Receptor Alpha)** - Multiple positive hits across species: - ATG_ERa_TRANS_up - ATG_ERE_CIS_up (Estrogen Response Element) - ATG_hERa_EcoTox2_up - ATG_hERa_XSP2_up - ATG_chERa_XSP2_up (chicken) - ATG_frER1_EcoTox2_up (fathead minnow) - ATG_frER1_XSP2_up (fathead minnow) - ATG_frER2_XSP2_up (fathead minnow) - ATG_trERa_XSP2_up (trout) - ATG_zfER2a_XSP2_up (zebrafish) - ATG_zfER2b_XSP2_up (zebrafish) - TOX21_ERa_BLA_Antagonist_ch2 - TOX21_ERa_BLA_Antagonist_ratio **ERβ (Estrogen Receptor Beta)**: - ATG_hERb_XSP2_up - TOX21_ERb_BLA_Agonist_viability - TOX21_ERb_BLA_Antagonist_ratio - TOX21_ERb_BLA_Antagonist_viability **ERR (Estrogen-Related Receptor)**: - TOX21_ERR_Antagonist #### 2. PPAR (Peroxisome Proliferator-Activated Receptor) Activation (Very Strong Signal) **PPARα** - Multiple species: - ATG_PPARa_TRANS_up - ATG_hPPARa_EcoTox2_up (human) - ATG_frPPARa_EcoTox2_up (fathead minnow) - ATG_jmPPARa_EcoTox2_up (Japanese medaka) - ATG_rtPPARa_EcoTox2_up (rat) - ATG_zfPPARa_EcoTox2_up (zebrafish) - ATG_PPRE_CIS_up (PPAR Response Element) **PPARγ**: - ATG_PPARg_TRANS_up - ATG_hPPARg_EcoTox2_up - ATG_hPPARg_XSP2_up - ATG_jmPPARg_EcoTox2_up (Japanese medaka) - ATG_mPPARg_XSP2_up (mouse) - NVS_NR_hPPARg - TOX21_PPARg_BLA_antagonist_ratio **PPARδ**: - TOX21_PPARd_BLA_agonist_ratio - TOX21_PPARd_BLA_Antagonist_ch2 - TOX21_PPARd_BLA_antagonist_ratio #### 3. RXR (Retinoid X Receptor) Activation - ATG_RXRb_TRANS_up - ATG_hRXRb_EcoTox2_up (human) - ATG_frRXRb_EcoTox2_up (fathead minnow) - ATG_jmRXRb_EcoTox2_up (Japanese medaka) - TOX21_RXR_BLA_Agonist_ratio #### 4. Hepatic Gene Expression Changes (Liver Effects) **Drug Metabolizing Enzymes**: - LTEA_HepaRG_CYP1A1_up - LTEA_HepaRG_CYP2B6_up - LTEA_HepaRG_CYP2C19_up - LTEA_HepaRG_CYP2C8_up - LTEA_HepaRG_CYP2E1_up - LTEA_HepaRG_CYP3A7_up - LTEA_HepaRG_CYP4A11_up - LTEA_HepaRG_CYP4A22_up - CLD_CYP2B6_24hr - CLD_GSTA2_48hr **Transporters**: - LTEA_HepaRG_ABCC2_up - LTEA_HepaRG_ABCC3_up **Phase II Enzymes**: - LTEA_HepaRG_UGT1A1_up - LTEA_HepaRG_SULT2A1_up **Lipid Metabolism**: - LTEA_HepaRG_ACLY_up (ATP citrate lyase) - LTEA_HepaRG_ACOX1_up (acyl-CoA oxidase) - LTEA_HepaRG_FABP1_up (fatty acid binding protein) - LTEA_HepaRG_FASN_up (fatty acid synthase) - LTEA_HepaRG_HMGCS2_up (HMG-CoA synthase) - LTEA_HepaRG_PDK4_up (pyruvate dehydrogenase kinase) - CLD_HMGCS2_48hr **Stress Response & Other Hepatic Genes**: - LTEA_HepaRG_DDIT3_up (DNA damage-inducible transcript 3) - LTEA_HepaRG_GADD45B_up (growth arrest and DNA damage) - LTEA_HepaRG_GADD45G_up - LTEA_HepaRG_NFE2L2_up (Nrf2) - LTEA_HepaRG_XBP1_up (X-box binding protein 1) - LTEA_HepaRG_CAT_up (catalase) - LTEA_HepaRG_FMO3_up (flavin-containing monooxygenase) - LTEA_HepaRG_FOXO3_up - LTEA_HepaRG_IL6R_up (IL-6 receptor) - LTEA_HepaRG_SDHB_up (succinate dehydrogenase) - LTEA_HepaRG_TGFA_up (transforming growth factor alpha) - LTEA_HepaRG_ALPP_dn (alkaline phosphatase, decreased) - LTEA_HepaRG_CDKN1A_dn (p21, decreased) - LTEA_HepaRG_THRSP_dn (thyroid hormone responsive, decreased) #### 5. Thyroid Hormone Disruption **Thyroid Receptor Antagonism**: - ATG_hTRa_XSP2_dn (downregulation) - ATG_THRa1_TRANS_dn **Thyroid Transport Protein**: - CCTE_GLTED_hTTR_dn (reduced transthyretin binding) #### 6. Oxidative Stress & Antioxidant Response - ATG_NRF2_ARE_CIS_up (Nrf2/ARE pathway activation) - LTEA_HepaRG_CAT_up (catalase) - TOX21_ARE_BLA_Agonist_ch2 - TOX21_ARE_BLA_agonist_ratio #### 7. Neurotoxicity **Reduced Cell Viability & Neurite Outgrowth**: - UKN4_HCS_LUHMES_cell_viability_dn - UKN4_HCS_LUHMES_neurite_outgrowth_dn - UKN5_HCS_SBAD2_cell_viability_dn - UKN5_HCS_SBAD2_neurite_outgrowth_dn - IUF_NPC1a_proliferation_BrdU_72hr_dn **Neuronal Network Activity (MEA assays)**: - CCTE_Shafer_MEA_dev_network_spike_duration_std_dn - CCTE_Shafer_MEA_dev_network_spike_peak_dn - CCTE_Shafer_MEA_dev_per_network_spike_spike_percent_up - CCTE_Shafer_MEA_dev_spike_duration_mean_dn #### 8. Inflammatory Responses **Cytokines & Chemokines**: - BSK_3C_IL8_up - BSK_IMphg_IL8_up - BSK_LPS_IL8_up - BSK_BT_xTNFa_up - BSK_LPS_TNFa_down - BSK_CASM3C_MIG_up - BSK_BF4T_MCP1_down - BSK_4H_Eotaxin3_down - BSK_4H_Eotaxin3_up - BSK_LPS_MCSF_up - BSK_IMphg_IL10_down **Matrix Metalloproteinases**: - BSK_BE3C_MMP1_up - BSK_BE3C_MMP9_up **Adhesion Molecules & Other Inflammatory Markers**: - BSK_3C_uPAR_down - BSK_3C_VCAM1_down - BSK_4H_uPAR_down - BSK_KF3CT_ICAM1_down - BSK_KF3CT_PAI1_down - BSK_LPS_Eselectin_up - BSK_LPS_Thrombomodulin_up - BSK_BE3C_IP10_down - BSK_BF4T_tPA_down #### 9. Cell Proliferation & Cytotoxicity **Increased Proliferation**: - BSK_BT_Bcell_Proliferation_up - BSK_CASM3C_Proliferation_up - BSK_hDFCGF_Proliferation_up **Cytotoxicity & Cell Viability**: - BSK_BT_PBMCCytotoxicity_up - BSK_3C_SRB_down (reduced viability) - APR_HepG2_CellLoss_72h_dn - TOX21_RT_HEPG2_GLO_00hr_ctrl_viability **Mitochondrial & Cellular Effects**: - APR_HepG2_MitoMembPot_72h_dn (mitochondrial membrane potential disruption) - APR_HepG2_MicrotubuleCSK_72h_up - TOX21_MMP_fitc - BSK_MyoF_CollagenIV_up #### 10. Other Nuclear Receptor & Transcription Factor Effects **Nuclear Receptors**: - NVS_NR_hCAR_Antagonist (CAR antagonism) - ATG_PXRE_CIS_up (PXR activation) - ATG_NURR1_TRANS_up **Transcription Factors**: - ATG_AP_1_CIS_up (AP-1) - ATG_Sp1_CIS_up (Sp1) - ATG_p53_CIS_dn (p53, decreased) - ATG_TCF_b_cat_CIS_dn (Wnt/β-catenin, decreased) - ATG_DR4_LXR_CIS_dn (LXR, decreased) - ATG_ISRE_CIS_dn (interferon-stimulated response element, decreased) - ATG_RORE_CIS_dn (ROR response element, decreased) #### 11. Enzyme & Receptor Binding **Enzymes**: - NVS_ADME_rCYP2A2 - NVS_ADME_rCYP2C11_Activator - NVS_ENZ_hACP1 (acid phosphatase) - NVS_ENZ_hBACE (beta-secretase) - NVS_ENZ_hPI3Ka (phosphoinositide 3-kinase) - NVS_ENZ_hPPP1CA (protein phosphatase 1) - NVS_ENZ_hPPP2CA (protein phosphatase 2) - NVS_ENZ_hTie2 (tyrosine kinase) **GPCRs**: - NVS_GPCR_gLTB4 (leukotriene B4 receptor) - NVS_GPCR_hAdoRA2a (adenosine A2a receptor) - NVS_GPCR_hLTB4_BLT1 (leukotriene B4 receptor) #### 12. Additional Cellular Effects - BSK_hDFCGF_EGFR_down (EGFR downregulation) - BSK_LPS_PGE2_down (prostaglandin E2 reduction) --- ## Summary of Toxicological Profile Based on the 147 positive assay results, PFOA demonstrates: ### Primary Mechanisms of Action 1. **Endocrine Disruption**: Strong estrogenic and anti-estrogenic activity; thyroid hormone disruption 2. **PPAR Agonism**: Potent activation of PPARα and PPARγ pathways across multiple species 3. **Metabolic Disruption**: Induction of hepatic drug-metabolizing enzymes and alterations in lipid metabolism 4. **Oxidative Stress Induction**: Activation of Nrf2/ARE antioxidant response pathways 5. **Neurotoxicity**: Reduced neuronal cell viability and neurite outgrowth 6. **Immunomodulation**: Effects on inflammatory cytokines and immune cell function ### Biological Systems Affected - **Liver**: Extensive changes in metabolic enzyme expression and lipid metabolism - **Endocrine System**: Multiple hormone receptor pathways disrupted - **Nervous System**: Neurotoxic effects and altered neuronal network activity - **Immune System**: Inflammatory cytokine modulation - **Cellular Function**: Mitochondrial dysfunction, oxidative stress, altered proliferation ### Toxicological Significance These findings are consistent with known PFOA health concerns including: - Liver toxicity and metabolic disease - Endocrine disruption (reproductive and thyroid effects) - Developmental neurotoxicity - Immune system dysfunction - Potential carcinogenic effects (p53 pathway disruption) --- ## Technical Notes **Database**: EPA ToxCast/Tox21 InvitroDB via BioBricks knowledge graph **Chemical ID**: DTXSID8031865 (Perfluorooctanoic acid) **CAS Number**: 335-67-1 **Total Assays**: 1,396 **Positive Hits**: 147 (10.5% hit rate) **Data Format**: SPARQL queries against RDF knowledge graph --- *Analysis completed: December 11, 2025*