WY-14643 (Pirinixic Acid): Selective PPARα Agonist for Metabolic and Inflammatory Research

Executive Summary: WY-14643 (Pirinixic Acid) is a potent, selective agonist of peroxisome proliferator-activated receptor alpha (PPARα) with an IC₅₀ of 10.11 µM in human PPARα assays, facilitating targeted modulation of lipid metabolism and inflammation [APExBIO]. Aliphatic α-substitution enhances its activity toward both PPARα and PPARγ, generating dual agonists effective in the lower micromolar range. In vivo, WY-14643 administration at 3 mg/kg/day for two weeks reduces plasma glucose, triglycerides, leptin, and visceral fat in high fat-fed rats without promoting weight gain. The compound also down-regulates TNF-α-induced VCAM-1 expression in endothelial cells, suggesting robust anti-inflammatory properties. Recent studies confirm that PPARα activation by WY-14643 mediates hepatomegaly and liver regeneration via the YAP-TEAD axis in mouse models [Pepstatina].

Biological Rationale

Peroxisome proliferator-activated receptors (PPARs) are nuclear receptors central to the regulation of lipid metabolism, glucose homeostasis, and inflammatory responses [DAPT.us]. PPARα specifically governs the expression of genes encoding enzymes involved in fatty acid β-oxidation, lipoprotein assembly, and inflammatory mediators. Dysregulation of PPARα signaling is implicated in metabolic disorders, nonalcoholic fatty liver disease (NAFLD), and cardiovascular conditions. WY-14643 (Pirinixic Acid), developed as a research tool, enables selective activation of PPARα, providing critical insights into receptor-driven metabolic and immunological pathways [APExBIO]. Unlike pan-PPAR agonists, WY-14643's selectivity allows researchers to dissect PPARα-specific effects independently of PPARβ/δ or PPARγ influences. Recent discoveries also indicate a regulatory axis between PPARα activation and liver regeneration via the YAP-TEAD pathway [ArotinololChem], extending the compound's utility beyond classic metabolic investigations.

Mechanism of Action of WY-14643 (Pirinixic Acid)

WY-14643 operates as a potent and selective agonist for PPARα, binding to the ligand-binding domain and inducing a conformational shift that promotes co-activator recruitment and target gene transcription. The reported IC₅₀ for human PPARα is 10.11 µM, establishing its high affinity and functional specificity [APExBIO]. Aliphatic α-substitution further enhances agonistic activity, enabling balanced dual activation of PPARα and PPARγ in the low micromolar range. Functionally, WY-14643 upregulates genes involved in fatty acid transport (e.g., CPT1A, ACOX1), β-oxidation, and downregulates proinflammatory mediators such as VCAM-1 and TNF-α-driven pathways. In liver tissue, PPARα activation by WY-14643 promotes hepatocyte proliferation and regeneration, partially mediated via the YAP-TEAD interaction, as demonstrated in murine models [Pepstatina]. The compound's dual activity also allows for moderate engagement of PPARγ, impacting adipogenesis and insulin sensitivity in metabolic disease models.

Evidence & Benchmarks

• WY-14643 exhibits an IC₅₀ of 10.11 µM for human PPARα, confirming high potency and selectivity (APExBIO product page).
• Aliphatic α-substitution on WY-14643 increases dual PPARα/γ agonistic activity, enabling balanced agonism in the lower micromolar range (Y27632.com).
• In high fat-fed rat models, oral WY-14643 at 3 mg/kg/day for 2 weeks lowers plasma glucose, triglycerides, leptin, visceral fat, and muscle triglyceride content without increasing body weight (APExBIO).
• WY-14643 treatment in endothelial cells (250 µM, pretreatment) significantly down-regulates TNF-α-induced VCAM-1 expression and reduces monocyte adhesion, demonstrating anti-inflammatory effects (Anti-Inflammatory Peptide).
• In murine models, intraperitoneal administration of 100 mg/kg/day WY-14643 for 10 days induces hepatomegaly and facilitates liver regeneration via YAP-TEAD signaling, confirmed by liver tissue and serum analysis (Pepstatina.com).
• WY-14643 is a solid compound, insoluble in water but soluble in DMSO (≥16.2 mg/mL) and ethanol (≥48.8 mg/mL with ultrasound), with recommended storage at -20°C (APExBIO).

Applications, Limits & Misconceptions

WY-14643 is extensively utilized in preclinical research on metabolic disorders, including metabolic syndrome, NAFLD, and insulin resistance. Its dual PPARα/γ activity broadens applicability to studies on adipogenesis and glucose metabolism. The compound's anti-inflammatory effects in endothelial cells position it as a tool for dissecting TNF-α-mediated inflammation and vascular dysfunction. In hepatology, WY-14643 has enabled elucidation of the YAP-TEAD axis in liver regeneration, distinguishing PPARα-dependent proliferative responses from PPARα-independent mechanisms [ArotinololChem].

DAPT.us previously summarized WY-14643's role in metabolic applications; this article extends the discussion to recent mechanistic findings on the YAP-TEAD axis and clarifies workflow parameters for reproducibility.

Common Pitfalls or Misconceptions

• Not for diagnostic/clinical use: WY-14643 is supplied strictly for research purposes and lacks approval for therapeutic applications (APExBIO).
• Water insolubility: The compound is not soluble in aqueous buffers; improper dissolution can lead to precipitation and loss of bioactivity (APExBIO).
• Short-term solution stability: Working solutions in DMSO/ethanol are recommended for short-term use only; prolonged storage reduces efficacy.
• Species-specific responses: Data obtained in rodents may not fully extrapolate to human metabolic or regenerative biology.
• Overgeneralizing dual agonism: Although α-substituted analogs show dual PPARα/γ activity, native WY-14643 is primarily PPARα-selective; experimental context matters.

Workflow Integration & Parameters

For in vitro studies, WY-14643 is typically dissolved in DMSO at concentrations up to 16.2 mg/mL; ultrasonic assistance increases ethanol solubility to 48.8 mg/mL. Recommended working concentrations range from 10–250 µM, depending on cell type and endpoint. In vivo, oral or intraperitoneal dosing protocols have used 3 mg/kg/day (metabolic studies in rats) or 100 mg/kg/day (hepatomegaly/liver regeneration studies in mice) for up to 14 days. Storage at -20°C is essential for compound integrity. APExBIO provides detailed technical documentation for the A4305 kit, supporting reproducible application in metabolic and inflammatory models [APExBIO].

For advanced mechanistic insights, researchers may consult Pepstatina.com, which details the role of WY-14643 in YAP-TEAD-mediated liver regeneration—a perspective not covered in conventional metabolic disorder research.

Conclusion & Outlook

WY-14643 (Pirinixic Acid) remains a gold-standard selective PPARα agonist for dissecting metabolic, inflammatory, and regenerative pathways in preclinical models. Its dual PPARα/γ profile, robust anti-inflammatory properties, and well-characterized workflow parameters support its broad adoption in metabolic disorder research. Recent findings on the YAP-TEAD axis highlight new translational directions in liver biology. For validated protocols and compound sourcing, APExBIO’s A4305 kit provides a reliable resource. Continued research will further delineate WY-14643's utility in bridging metabolic regulation and tissue regeneration.