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Evidence Chain Reported by the Authors

The paper builds a linear causal pathway across six figures: (1) live but not UV-inactivated PRV raises ROS by 12–24 hpi; (2) the antioxidant NAC lowers ROS and reduces viral gB expression and TCID₅₀ titers while restoring MAVS protein and IFN-β/IFIT1/ISG15 transcription NAC rescue of MAVS and IFN response; (3) NAC preserves mitochondrial membrane potential, fusion proteins (MFN1/2, OPA1) and blocks PINK1/Parkin phosphorylation, LC3-II and p62 changes; (4) PRV phosphorylates AMPK-Thr172 and ULK1-Ser555 without altering mTOR, including mitochondria-localized AMPK; dorsomorphin and siAMPK both block mitophagy and reduce titers; (5) MCU-i4 blocks mtCa²⁺ uptake, rescuing MMP, ROS, AMPK phosphorylation and replication; (6) PRV raises Nrf2 protein yet blocks its nuclear translocation, and the Nrf2 activator sulforaphane restores HO1/NQO1 and suppresses titers Ca2+ overload and Nrf2 sequestration evidence.

This map encodes only reported directional changes — the paper reports fold changes in figures without tabulated numeric values, so no precise quantitative replot is possible.

Critical Appraisal

Strengths: mechanistic triangulation with orthogonal perturbations (chemical scavenger NAC, AMPK inhibitor + siRNA, MCU inhibitor, Nrf2 activator SFN); use of UV-inactivated and live virus controls to establish replication dependence; two PRV strains (recombinant G-PRV and wild-type W-PRV) across assays; three independent experiments per assay. This sits within the authors' prior 2024 demonstration that PRV-induced mitophagy degrades MAVS Precedent MAVS-mitophagy study.

Weaknesses and blind spots: (a) all experiments are in a single PK-15 cell line at MOI 1 — pig-specific, immortalized, and not neurotropic-relevant; the authors themselves acknowledge the absence of animal models Author-stated animal model limitation. (b) Pharmacological off-targets are substantial: dorsomorphin also inhibits BMP/TGF-β kinases; NAC at 30–40 mM can affect thiol-dependent proteins beyond ROS; SFN has Nrf2-independent effects. Genetic rescue (AMPK-null, Parkin-null, Nrf2-null) would strengthen causality — only siAMPK was used. (c) A known complication from the broader literature: ULK1 can phosphorylate AMPK subunits forming a negative feedback loop that inhibits AMPK activation ULK1-AMPK negative feedback — the paper reports this axis as purely linear and does not test feedback phosphorylation timing. (d) Correlation-ordering evidence (time/dose dependence) substitutes for kinetic epistasis; whether mtCa²⁺ overload precedes or follows ROS is not temporally resolved with fine time course. (e) Flow cytometry mean-fluorescence readouts (DCFH-DA) are prone to probe artifact and cell-count confounding from virus-induced cytotoxicity.

What would falsify the model: Parkin-null or PINK1-null PK-15 cells showing NAC-independent PRV replication; in vivo antioxidant effects absent in pigs; AMPK Thr172 phosphorylation kinetics that precede detectable ROS rise (breaking the causal ordering).

Confidence note: the qualitative mechanism is plausibly supported within the cell-culture context (moderate evidence), but generalization to animals, neurotropic infection, or therapeutic antioxidant strategies is untested.

 BGPT Paper Review

Study Novelty

The AMPK-ULK1-Parkin mitophagy axis and Nrf2 sequestration are individually well established; the novelty is the specific PRV-triggered chain (mtCa²⁺ overload → ROS → AMPK-ULK1 → MAVS mitophagic degradation), extending the authors' 2024 mitophagy finding upstream.

Scientific Quality

Systematic perturbation logic and inclusion of live vs UV-inactivated controls are commendable, but reliance on single-cell-line pharmacology, off-target-prone inhibitors (dorsomorphin, NAC, SFN), lack of genetic rescue for Parkin/Nrf2, and no animal validation cap the quality. No data fabrication or prompt-injection concerns detected.

Study Generality

The ROS→AMPK-ULK1→mitophagy→MAVS immune-evasion logic generalizes to other herpesviruses and viral pathogenesis, but evidence is specific to PK-15/PRV.

Study Usefulness

Identifies MCU inhibition and Nrf2 activation as antiviral entry points and offers a mechanistic basis for antioxidant strategies against PRV; directly actionable for veterinary virologists pending in vivo confirmation.

Study Reproducibility

Methods detail reagents, antibodies, siRNA sequences, primers, and statistical tests, and all data are within the manuscript; however, raw densitometry values and some replicate statistics are only in figures, limiting exact reproduction.

Explanatory Depth

The pathway is delineated at the level of organelle events (ER-mito contact, mtCa²⁺, MMP, Nrf2 translocation) and phosphorylation events (AMPK T172, ULK1 S555, PINK1/Parkin S65), but the upstream viral effector driving ER-mitochondria tethering and the precise Nrf2 sequestration mechanism remain unresolved — the authors admit no dominant viral protein was identified.