Benzothiazepine CGP37157 Analogues Exert Cytoprotection in Various in Vitro Models of Neurodegeneration

Mitochondria regulate cellular Ca²⁺ oscillations, taking up Ca²⁺ through its uniporter and releasing it through the mitochondrial sodium/calcium exchanger. The role of mitochondria in the regulation of Ca²⁺ cycle has received much attention recently, as it is a central stage in neuronal survival and death processes. Over the last decades, the 4,1-benzothiazepine CGP37157 has been the only available blocker of the mitochondrial sodium/calcium exchanger, although it targets several other calcium transporters. We report the synthesis of 4,1-benzothiazepine derivatives with the goal of enhancing mitochondrial sodium/calcium exchanger blockade and selectivity, and the evaluation of their cytoprotective effect. The compound 4c presented an interesting neuroprotective profile in addition to an important blockade of the mitochondrial sodium/calcium exchanger. The use of this benzothiazepine could help to understand the physiological functions of the mitochondrial sodium/calcium exchanger. In addition, we hypothesize that a moderate blockade of the mitochondrial sodium/calcium exchanger would provide enhanced neuroprotection in neurons.