The omega-3 hydroxy fatty acid 7( S )-HDHA is a high-affinity PPARα ligand that regulates brain neuronal morphology

Abstract

The nuclear receptor peroxisome proliferator-activated receptor alpha (PPARα) is emerging as an important target in the brain for the treatment or prevention of cognitive disorders. The identification of high-affinity ligands for brain PPARα may reveal the mechanisms underlying the synaptic effects of this receptor and facilitate drug development. Here, using an affinity purification–untargeted mass spectrometry (AP-UMS) approach, we identified an endogenous, selective PPARα ligand, 7( S )-hydroxy-docosahexaenoic acid [7( S )-HDHA]. Results from mass spectrometric detection of 7( S )-HDHA in mouse and rat brain tissues, time-resolved FRET analyses, and thermal shift assays collectively revealed that 7( S )-HDHA potently activated PPARα with an affinity greater than that of other ligands identified to date. We also found that 7( S )-HDHA activation of PPARα in cultured mouse cortical neurons stimulated neuronal growth and arborization, as well as the expression of genes associated with synaptic plasticity. The findings suggest that this DHA derivative supports and enhances neuronal synaptic capacity in the brain.

Disclosing Environmental Ligands of L-FABP and PPARγ: Should We Re-evaluate the Chemical Safety of Hydrocarbon Surfactants?

“…To identify environmental contaminants binding to L-FABP and PPARγ in indoor dust and sewage sludge, APNA was employed. − In this study, indoor dust and sewage sludge were selected for testing because they represent important reservoirs for commercial chemicals and have long been used as promising sources to measure the collective consumption or chemical exposure of humans. , To prepare the indoor dust or sewage sludge extracts, approximately 0.5 g of indoor dust or freeze-dried sewage sludge was extracted twice with 5 mL of methanol, and the extracts were blown down and reconstituted to a final volume of 1 mL before use. His-tagged full length L-FABP or His-tagged PPARγ ligand binding domain (LBD) were overexpressed in E. coli cells.…”

“…This overcomes the major challenge of coelution in EDA and largely reduces false discovery rates. This method has been employed in our recent studies to identify chemical contaminants binding to multiple human − and bacterial proteins . A major advantage of APNA is the capacity to simultaneously isolate multiple ligands from complex environmental mixtures, which is ideal for the identification of unknown PPARγ ligands.…”

“…A bioanalytical method “protein A ffinity P urification with N ontargeted A nalysis (APNA)” has been proposed in our previous studies for the screening of protein ligands in the environment, on the exposome-wide level. − Distinct from the conventional EDA method relying on LC fractionation, APNA uses a tagged protein (e.g., NR) as a “bait” to directly isolate ligands from environmental mixtures consisting of thousands of chemicals . This overcomes the major challenge of coelution in EDA and largely reduces false discovery rates.…”

Systems levels analysis of lipid metabolism in oxygen-induced retinopathy

“…Our correlation analysis further indicates CREBH and PPARα based induction of hepatic FGF21 expression and induces secretion into the plasma. One of the known endogenous activators of PPARα is 7(S)-Hydroxydocosahexaenoic acid which is a derivative of DHA [44]. DHA levels have been demonstrated to negatively correlate with severity of ROP [45].…”

In Vitro Safety Signals for Potential Clinical Development of the Anti-Inflammatory Pregnane X Receptor Agonist FKK6

“…The amplified DNA was inserted into the pET28-MHL vector by In-Fusion HD Cloning. Recombinant proteins were expressed as previously described [21]. Proteins were purified using of HisPur Ni-NTA resin (Thermo Fisher Scientific, 88222), followed by size exclusion FPLC (HiLoad 16/60 Superdex 200, GE Healthcare, Life Sciences) equilibrated with 150 mM NaCl, 50 mM HEPES (pH 8.2) and 0.5 mM DTT, at a flow rate of 1 mL/min.…”