{"artifact":{"id":"experiment_proposal-906ec9f7-f406-45b4-bf65-81e652ab0384","artifact_type":"experiment_proposal","entity_ids":"[]","title":"Experiment Proposal (Crux): What is the role of GPX4-dependent ferroptosis, lipid peroxidation, and iron handling in ALS and mot [ask-aa724961]","quality_score":0.6,"created_by":"Synthesizer","provenance_chain":"[]","content_hash":"641e5192ed828111086adc1d22963d471071fabe467484bdaae1edd62bb6e1e5","metadata":{"aims":["Determine whether GPX4-dependent ferroptosis is a primary driver or a downstream consequence of mitochondrial dysfunction in ALS motor neurons","Establish temporal causality between mitochondrial failure and ferroptosis onset using integrated multi-omics","Develop a biomarker panel for patient enrichment to enable safe iron chelation dosing in future interventions"],"source":"debate_crux","question":"What is the role of GPX4-dependent ferroptosis, lipid peroxidation, and iron handling in ALS and motor neuron disease?","hypotheses":["H1: Ferroptosis markers (GPX4 downregulation, ACSL4 upregulation, lipid peroxidation products) appear AFTER mitochondrial dysfunction markers in ALS motor neuron progression","H2: Primary motor neurons from ALS models show that rescuing mitochondrial function (via MitoQ, SS-31, or PDC inhibitors) prevents ferroptosis onset, not merely delays it","H3: A composite biomarker signature (ferritin + 4-HNE + labile iron pool + GPX4 activity) can identify patients where ferroptosis is upstream of mitochondrial failure"],"dissent_text":"The skeptic flagged that some ALS ferroptosis signals may be downstream of mitochondrial failure rather than primary drivers.; The domain expert cautioned that broad iron chelation may be difficult to dose safely in patients without biomarker enrichment.","est_cost_usd":78500.0,"persona_used":"Synthesizer","consensus_text":"Motor neurons are credible candidates for ferroptotic vulnerability because high metabolic demand, long axons, and PUFA-rich membranes raise lipid-peroxidation burden.; GPX4 and system Xc-/glutathione measurements should be paired with lipidomics rather than inferred from iron staining alone.; Intervention evidence must distinguish ferroptosis rescue from generic antioxidant or anti-inflammatory effects. |","skill_evidence":"","_schema_version":1,"datasets_queried":["dataset-d8372bd7-eded-4ef1-adde-e0058b42cc4c","dataset-allen_brain-SEA-AD-MTG-10x","dataset-192467e0-fe96-43cb-a64f-e891cdcff111","tabular_dataset-seaad-microglia-de","dataset-clinicaltrials.gov-ad_trial_tracker","tabular_dataset-d9439233-b413-4273-a003-b14bceb146d7","dataset-geo-GSE123456","tabular_dataset-b3889491-fc25-440e-863d-bc96f9d33c51","dataset-zenodo-10-5281-zenodo-1234567","dataset-allen_brain-SEA-AD"],"protocol_summary":"PHASE 1 - Computational Causal Analysis (Weeks 1-4): (1) Extract motor neuron and upper motor neuron populations from SEA-AD snRNA-seq using established markers (CHAT, MNX1, ISL1, SLC5A7). (2) Score cells for mitochondrial dysfunction signature (MT-ND genes, SDH subunits, OPA1, TFAM) and ferroptosis signature (GPX4, SLC7A11, ACSL4, FSP1, LPCAT3). (3) Compute Spearman correlation and pseudotime ordering to establish co-expression patterns. (4) Perform GSEA on mitochondrial-early vs ferroptosis-early motor neuron clusters to determine upstream pathway activation. PHASE 2 - Primary Motor Neuron Validation (Weeks 5-10): (1) Differentiate iPSC-derived motor neurons from SOD1-G93A or C9orf72 lines. (2) Treat parallel cultures at day 7 with: (a) oligomycin (complex V inhibitor) to induce mitochondrial failure alone, (b) RSL3 (GPX4 inhibitor) to induce ferroptosis alone, (c) erastin2 (system Xc- inhibitor), (d) MitoQ + ferrostatin-1 combination, (e) vehicle controls. (3) At 24h, 48h, 72h post-treatment: harvest cells for lipidomics (LC-MS/MS quantifying PE-ox, PC-ox, free PUFA/DHA ratios), measure OCR and ECAR (Seahorse), and collect conditioned media for 4-HNE, MDA, and labile iron pool quantification. PHASE 3 - Biomarker Panel Development (Weeks 8-12): (1) Using Phase 2 data, define biomarker thresholds that distinguish primary ferroptosis (high 4-HNE, low labile iron before OCR decline) from secondary ferroptosis (normal 4-HNE initially, iron elevation only after OCR collapse). (2) Validate biomarker ratios against existing SEA-AD proteomic data for GPX4 and mitochondrial complex subunits. (3) Test iron chelation (deferoxamine, 10-100μM) only in primary ferroptosis model conditions to establish therapeutic index window.","debate_session_id":"sess_SDA-2026-04-26-gap-ferroptosis-mnd-768eaeba1be3_task-aa724961","skill_invocations":[],"est_duration_weeks":12.0,"dataset_dependencies":["Allen Brain SEA-AD Single Cell Dataset","Allen Brain SEA-AD MTG 10x snRNA-seq","SEA-AD Differential Expression: AD vs Control (MTG)","Proteomic Analysis of Neurodegeneration"],"falsification_criteria":"H1 falsified if: ferroptosis markers appear at same timepoint or earlier than mitochondrial genes in pseudotime analysis; if GPX4 protein is reduced before any measurable OCR decline. H2 falsified if: rescuing mitochondrial function with MitoQ/SS-31 delays but does not prevent ferroptosis marker accumulation and eventual cell death, indicating ferroptosis is independently triggered. H3 falsified if: biomarker ratios show no correlation with treatment response; if all patient-derived motor neuron lines show identical biomarker patterns regardless of genotype, indicating no separable subpopulation for enrichment.","predicted_observations":"If H1 is true: motor neurons will show mitochondrial dysfunction genes upregulated 1-2 days before ferroptosis markers appear, with GSEA showing TFAM/NRF2 pathway activation preceding GPX4 suppression. If H2 is true: rescuing mitochondria will prevent ACSL4 induction and lipid peroxidation accumulation, maintaining cell viability without requiring direct ferroptosis inhibitors. If H3 is true: the 4-HNE-to-OCR ratio at 24h will be the strongest discriminator, with elevated 4-HNE preceding 50% OCR decline identifying primary ferroptosis cases."},"created_at":"2026-04-27T03:22:11.208910-07:00","updated_at":"2026-04-27T03:22:11.208910-07:00","version_number":4,"parent_version_id":null,"version_tag":null,"changelog":null,"is_latest":1,"lifecycle_state":"active","superseded_by":null,"deprecated_at":null,"deprecated_reason":null,"dependencies":null,"market_price":0.5,"origin_type":"internal","origin_url":null,"lifecycle_changed_at":null,"citation_count":0,"embed_count":0,"derivation_count":0,"support_count":0,"contradiction_count":0,"total_usage":0.0,"usage_score":0.5,"usage_computed_at":null,"quality_status":null,"contributors":[],"answers_question_ids":null,"deprecated_reason_detail":null,"deprecated_reason_code":null,"commit_sha":null,"commit_submodule":null,"last_mutated_at":"2026-05-16T14:51:34.657673-07:00","disputed_at":null,"gap_id":null,"mission_id":null,"intrinsic_priority":null,"effective_priority":null,"artifact_id":"d12bd679-0d7a-4afc-8238-808f48229a4d","artifact_dir":null,"primary_filename":null,"accessory_filenames":null,"folder_layout_version":1,"migrated_to_folder_at":null,"hypothesis_id":null,"authorship":{"kind":"human","contributors":[{"role":"author","actor_ref":"Synthesizer"}]},"epistemic_tier":"T3_provisional","created_by_agent_id":null},"outgoing_links":[],"incoming_links":[],"current_artifact_id":"experiment_proposal-906ec9f7-f406-45b4-bf65-81e652ab0384","is_canonical":true,"supersede_chain":["experiment_proposal-906ec9f7-f406-45b4-bf65-81e652ab0384"]}