c-Jun N-Terminal Kinases and Their Pharmacological Modulation in Ischemic and Reperfusion Brain Injury

Experimental and Computational Investigation of the Oxime Bond Stereochemistry in c-Jun N-terminal Kinase 3 Inhibitors 11H-Indeno[1,2-b]quinoxalin-11-one Oxime and Tryptanthrin-6-oxime

11H-Indeno[1,2-b]quinoxalin-11-one oxime (IQ-1) and tryptanthrin-6-oxime are potent c-Jun N-terminal kinase 3 (JNK-3) inhibitors demonstrating neuroprotective, anti-inflammatory and anti-arthritic activity. However, the stereochemical configuration of the oxime carbon-nitrogen double bond (E- or Z-) in these compounds was so far unknown. In this contribution, we report the results of the determination of the double bond configuration in the solid state by single crystal X-ray diffraction and in solution by 1D and 2D NMR techniques and DFT calculations. It was found that both in the solid state and in solution, IQ-1 adopts the E-configuration stabilized by intermolecular hydrogen bonds, in contrast to previously assumed Z-configuration that could be stabilized only by an intramolecular hydrogen bond.

Neuronal cell life, death, and axonal degeneration as regulated by the BCL-2 family proteins

Axonal degeneration and neuronal cell death are fundamental processes in development and contribute to the pathology of neurological disease in adults. Both processes are regulated by BCL-2 family proteins which orchestrate the permeabilization of the mitochondrial outer membrane (MOM). MOM permeabilization (MOMP) results in the activation of pro-apoptotic molecules that commit neurons to either die or degenerate. With the success of small-molecule inhibitors targeting anti-apoptotic BCL-2 proteins for the treatment of lymphoma, we can now envision the use of inhibitors of apoptosis with exquisite selectivity for BCL-2 family protein regulation of neuronal apoptosis in the treatment of nervous system disease. Critical to this development is deciphering which subset of proteins is required for neuronal apoptosis and axon degeneration, and how these two different outcomes are separately regulated. Moreover, noncanonical BCL-2 family protein functions unrelated to the regulation of MOMP, including impacting necroptosis and other modes of cell death may reveal additional potential targets and/or confounders. This review highlights our current understanding of BCL-2 family mediated neuronal cell death and axon degeneration, while identifying future research questions to be resolved to enable regulating neuronal survival pharmacologically.