Verdict. TNF-alpha tells trophoblasts to ADP-ribosylate via PARP1/2, drain NAD+, and lose respiratory spare capacity. Olaparib reverses the bioenergetic failure. Tankyrase inhibition does not. Subunits and 4-HNE stay put at 24 hours.
Metal sites and redox
The named couple is NAD+/NADH. PARP1/2 transfer ADP-ribose from NAD+ onto proteins, depleting the pool that complex I (FMN and Fe-S N-module) and TCA dehydrogenases need. This abstract does not report Fe-S nuclearity, heme, CuA/CuB, or a named respiratory cofactor as the olaparib target. 4-Hydroxynonenal, a lipid-peroxidation aldehyde, was measured and did not rise. Do not recast this as a ferroptosis or ROS-burst paper. Record the distinction: respiration is impaired, OXPHOS polypeptides are not lost, lipid aldehyde is unchanged.
What the authors report
Inflammation-mediated preeclampsia already carries extra NAD+-dependent ADP-ribosylation and NAD+ loss in placenta. In HTR-8/SVneo cells, TNF-alpha paints a PARP1-linked ~120 kDa MAR/PAR band. Olaparib wipes that band and lifts basal respiration, maximal respiration, ATP, and spare capacity. XAV939 does not. Human I-PE tissue does not show more PARP1/2 or tankyrase mRNA; the rat LPS model does raise some mono-ART PARPs. The 24-hour TNF-alpha window is a functional OXPHOS hit without a subunit or 4-HNE hit.
What was measured
Placental PARP/TNKS transcripts, MAR/PAR including the ~120 kDa species and its protein enrichment, Seahorse-style respiration, OXPHOS immunoblots, 4-HNE, migration, viability, olaparib versus XAV939.
Caveats
One cell line. One day. Olaparib is PARP1/2, not PARP1-selective. Cofactor integrity of Complexes I-IV is untested. Human rescue is not shown.
What to do with it
Treat inflammatory trophoblast energy failure as NAD+ consumed by PARP1/2. The next experiment is NAD+ repletion versus PARP blockade in tissue, and a check of whether mtDNA damage is the PARP trigger.
Bibliographic record
| Field | Value |
|---|---|
| Title | PARP1/2-linked ADP-ribosylation impairs trophoblast mitochondrial respiration in a TNF-α model of inflammation-mediated preeclampsia |
| DOI | 10.64898/2026.10.20.758860 |
| Server | biorxiv |
| Posted | 2026-10-21 |
| Topics | OXPHOS, NAD+, PARP, preeclampsia, trophoblast, bioenergetics |
| Mitos score | 87/100 |
| Confidence | medium |
| HTML | https://www.biorxiv.org/content/10.64898/2026.10.20.758860 |
| https://www.biorxiv.org/content/10.64898/2026.10.20.758860.full.pdf |
Abstract-based editorial synthesis by Mitos. Not peer review.