Dorsomorphin (Compound C): Selective ATP-Competitive AMPK and BMP Signaling Inhibitor

Executive Summary:
Dorsomorphin (Compound C, B3252) is a cell-permeable, reversible, and ATP-competitive inhibitor of AMP-activated protein kinase (AMPK) with a Ki of 109 nM, exhibiting high selectivity over kinases like PKA, PKC, and JAK3 (APExBIO Product Data). It suppresses ACC phosphorylation by 80% and inhibits autophagic proteolysis in cell-based models (Lei et al., 2025). Dorsomorphin also blocks BMP pathway signaling by preventing Smad 1/5/8 phosphorylation, impacting iron metabolism and neural induction (Strategic Dual-Pathway Inhibition). The compound is insoluble in water and ethanol but dissolves in DMSO at ≥8.49 mg/mL with gentle warming and sonication. Typical use ranges from 4–40 μM in vitro and up to 10 mg/kg intraperitoneally in vivo (APExBIO).

Biological Rationale

AMPK acts as a central regulator of cellular energy homeostasis. It is a serine/threonine kinase responsive to AMP/ATP ratios and modulates downstream targets such as acetyl-CoA carboxylase (ACC) and proteins involved in autophagy and metabolism (Lei et al., 2025). Dysregulation of AMPK activity is implicated in metabolic syndrome, obesity-related inflammation, and cancer. The BMP/Smad pathway orchestrates cellular differentiation, embryogenesis, and iron homeostasis. Dorsomorphin’s dual inhibition of AMPK and BMP/Smad signaling offers a unique tool for dissecting the interplay between metabolic and differentiation pathways in models of disease, including obesity, cancer, and neurodevelopmental disorders (Dorsomorphin Mechanistic Review).

Mechanism of Action of Dorsomorphin (Compound C)

• AMPK Inhibition: Dorsomorphin binds the ATP-binding pocket of AMPK, acting as a competitive inhibitor. The Ki value is 109 nM, demonstrating high potency (APExBIO).
• Selectivity: Dorsomorphin shows minimal inhibitory activity against related kinases including protein kinase A (PKA), protein kinase C (PKC), and Janus kinase 3 (JAK3) under standard assay conditions (APExBIO).
• BMP Pathway Antagonism: The compound inhibits BMP-induced phosphorylation of Smad 1/5/8, suppressing downstream transcriptional responses and reducing heterotopic ossification as well as hepatic hepcidin expression (Lei et al., 2025).
• Cellular Effects: Dorsomorphin decreases phosphorylation of ACC by 80% in AMPK-expressing cells and inhibits autophagic proteolysis (Strategic Dual-Pathway Inhibition).
• Stem Cell Differentiation: BMP inhibition by dorsomorphin promotes neural induction and self-renewal in human embryonic stem cells (Dorsomorphin Mechanistic Review).

Evidence & Benchmarks

• Dorsomorphin suppresses ACC phosphorylation by 80% in AMPK-positive hepatocytes (in vitro, 37°C, 5% CO₂) (APExBIO).
• IC₅₀ for BMP4-induced SMAD1/5/8 phosphorylation inhibition is 0.47 μM (cell-based assays) (Dorsomorphin Mechanistic Review).
• Downregulation of AMPK in obesity-related asthma models leads to increased M1 macrophage polarization and airway inflammation (Lei et al., 2025).
• Dorsomorphin administration in animal models (10 mg/kg, i.p.) reduces hepatic hepcidin mRNA levels and increases serum iron (APExBIO).
• The compound is insoluble in water and ethanol but dissolves in DMSO at ≥8.49 mg/mL with gentle warming and ultrasonication (APExBIO).
• Promotes neural induction in human embryonic stem cells via BMP pathway inhibition (Dorsomorphin Mechanistic Review).
• Demonstrated induction of dorsalization in zebrafish embryos at 4–40 μM in cell culture systems (APExBIO).

This article extends Dorsomorphin (Compound C): Precise AMPK and BMP Pathway Inhibitor by providing updated quantitative benchmarks and specific workflow integration details for translational models. It also clarifies the distinctions from Dorsomorphin (Compound C): Precision AMPK and BMP Inhibition in Muscle Research by focusing on iron metabolism and neural stem cell applications.

Applications, Limits & Misconceptions

• Inhibition of AMPK Activity in Hepatocytes: Dorsomorphin is extensively used to probe the AMPK signaling pathway in mammalian hepatocytes and HeLa cells.
• BMP4-Induced SMAD Phosphorylation Inhibition: Enables functional studies of the BMP/Smad signaling axis.
• Autophagy Regulation: Suppresses autophagic proteolysis, useful for dissecting autophagy in metabolic and neurodegenerative models (Precision AMPK and BMP Inhibition).
• Iron Metabolism Modulation: Reduces hepatic hepcidin, increases serum iron, and provides a model for studying iron homeostasis disorders.
• Neural Stem Cell Differentiation: Facilitates BMP pathway suppression to promote neural induction in pluripotent stem cell research.
• Cancer Research: Used to interrogate AMPK-mediated metabolic and growth regulatory mechanisms in cancer models (Strategic Dual-Pathway Inhibition).

Common Pitfalls or Misconceptions

• Dorsomorphin is not suitable for long-term solution storage; use solutions promptly after preparation (APExBIO).
• It is insoluble in water and ethanol; dissolving in DMSO is required for biological applications.
• The compound is not a pan-kinase inhibitor; it is highly selective for AMPK and BMP/Smad pathways.
• Does not directly inhibit downstream effectors of AMPK or BMP, but acts upstream at the kinase level.
• Results observed in zebrafish embryos or murine models may not fully translate to human pathophysiology without further validation.

Workflow Integration & Parameters

• Preparation: Dissolve dorsomorphin in DMSO at concentrations ≥8.49 mg/mL using gentle warming and/or ultrasonic treatment.
• Storage: Store as a solid at −20°C; avoid repeated freeze-thaw cycles. Solutions are not recommended for storage.
• Cell Culture Use: Apply at 4–40 μM in cell-based assays; titrate concentration based on target and cell type.
• Animal Models: Typical dosage is 10 mg/kg via intraperitoneal injection in rodents, with endpoints including hepcidin mRNA and serum iron measurements.
• Experimental Validation: Confirm AMPK inhibition by assessing ACC phosphorylation suppression; confirm BMP inhibition via SMAD1/5/8 phosphorylation readouts.

For full product specifications and lot-specific documentation, see the APExBIO Dorsomorphin (Compound C) product page.

Conclusion & Outlook

Dorsomorphin (Compound C, B3252) from APExBIO is an established, highly selective ATP-competitive inhibitor for both AMPK and BMP/Smad signaling pathways. It enables researchers to precisely interrogate metabolic, autophagic, and differentiation processes in translational models. Its defined mechanism of action, robust benchmarks, and clarified workflow parameters make it invaluable for metabolic syndrome, cancer, and stem cell research. Future research should address the translation of preclinical findings into human disease models and refine dosing strategies for new targets. For advanced discussions on dual-pathway inhibition, see the in-depth mechanistic review here.