Identification and functional validation of FDA-approved positive and negative modulators of the mitochondrial calcium uniporter

Summary

The mitochondrial calcium uniporter (MCU), the highly selective channel responsible for mitochondrial Ca ²⁺ entry, plays important roles in physiology and pathology. However, only few pharmacological compounds directly and selectively modulate its activity. Here, we perform high-throughput screening on a US Food and Drug Administration (FDA)-approved drug library comprising 1,600 compounds to identify molecules modulating mitochondrial Ca ²⁺ uptake. We find amorolfine and benzethonium to be positive and negative MCU modulators, respectively. In agreement with the positive effect of MCU in muscle trophism, amorolfine increases muscle size, and MCU silencing is sufficient to blunt amorolfine-induced hypertrophy. Conversely, in the triple-negative breast cancer cell line MDA-MB-231, benzethonium delays cell growth and migration in an MCU-dependent manner and protects from ceramide-induced apoptosis, in line with the role of mitochondrial Ca ²⁺ uptake in cancer progression. Overall, we identify amorolfine and benzethonium as effective MCU-targeting drugs applicable to a wide array of experimental and disease conditions.

Graphical abstract

Highlights

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  We screen an FDA-approved drug library for mitochondrial Ca ²⁺ uptake modulators

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  Amorolfine and benzethonium modulate MCU activity

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  Amorolfine increases MCU-dependent mitochondrial metabolism and muscle size

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  Benzethonium decreases MCU-dependent cancer cell growth and migration

Abstract

In search of mitochondrial Ca ²⁺ uptake modulators, De Mario et al. identify amorolfine and benzethonium as positive hits of a 1,600 FDA drug library high-throughput screen. Amorolfine increases mitochondrial metabolism and muscle size in an MCU-dependent manner. Benzethonium negatively regulates MCU activity, mROS formation, and cancer cell growth and migration.