Pharmacological Fingerprinting of Cholesterol Biosynthesis Defects.

Cholesterol biosynthesis is an interconnected metabolic network that generates cholesterol as well as numerous sterol and non-sterol intermediates with essential structural, signaling and regulatory functions. While inborn defects of this pathway have traditionally been employed to study the functions of these metabolites, it has recently been demonstrated that numerous drugs used to treat common diseases inhibit individual enzymes within this network. Pharmacological inhibition of individual biosynthetic enzymes provides an opportunity to investigate pathway disruption in mature organisms without confounding effects associated with altered embryonic development. The effects of such inhibition-particularly in the context of polypharmacy-may have either therapeutically beneficial or adverse consequences and therefore require experimental validation in appropriate models. In this review, we examine commercially available and in vivo validated pharmacological inhibitors of cholesterol biosynthesis enzymes. We further introduce the concept of the pharmacological fingerprint, defined by the characteristic combination of precursor accumulation, downstream sterol depletion, pathway shunting and secondary metabolic adaptations produced by inhibition of a defined enzymatic step. By characterizing the fingerprints of each of these compounds, we demonstrate that pre-lanosterol inhibition primarily affects mevalonate-derived non-sterol isoprenoids and associated cellular functions, whereas post-lanosterol inhibition predominantly alters the distribution and accumulation of sterol intermediates. The available evidence supports pharmacological models as complementary tools to genetic models for dissecting the biological function of individual biosynthetic intermediates and for investigating drug-induced sterol disturbances beyond developmental disorders. However, differences in model fidelity, incomplete characterization of tissue-specific effects, off-target drug effects and inconsistent sterol measurements currently limit direct comparison between models. Future studies should therefore combine standardized sterol profiling with systematic tissue-specific phenotyping. Such an approach could help establish reference fingerprints and improve the experimental and translational utility of pharmacological models.