Suppression of Age-Related Macular Degeneration-like Pathology by c-Jun N-Terminal Kinase Inhibitor IQ-1S

JNK Signaling Pathway Activity Alterations in the Rat Hippocampus: Effect of Age, Alzheimer's Disease-Like Pathology Development, and the JNK Inhibitor IQ-1S

Alzheimer's disease (AD) is a multifactorial neurodegenerative disorder and the leading cause of senile dementia. The key risk factor for a more common (>95% of cases) sporadic form of AD is age. So far, there are no effective methods for AD prevention or treatment. A growing body of evidence indicates that the development of AD and other neurodegenerative diseases is associated with the activation of mitogen-activated protein kinase (MAPK) pathways, and JNK signaling pathway is considered as a potential target for the prevention and treatment of AD. However, the information on alterations in its activity in ontogenesis, which are evaluated by changes in the phosphorylation of its components, is extremely limited. The aim of this study was to compare age-related changes in the activity of JNK signaling pathway in the hippocampus of Wistar rats and senescence-accelerated OXYS rats (which spontaneously develop the key symptoms of AD-like pathology) and to evaluate the effect of the selective JNK3 inhibitor IQ-1S (11H-indeno[1,2-b]quinoxalin-11-one oxime sodium salt). The ability of IQ-1S to suppress accelerated brain aging in OXYS rat has been proven previously, but the effect of this inhibitor on the JNK activity has not been studied. Here, we showed that with age, the activity of the JNK signaling pathway increased in the hippocampus of rats of both strains. At the same time, the manifestation and active progression of AD-like pathology in OXYS rats was accompanied by the increase in the phosphorylation level of the key kinase of this signaling pathway, JNK3, and its target proteins compared to Wistar rats, which allowed us to suggest JNK3 as a potential target for interventions aimed at preventing neurodegenerative processes. This suggestion was supported by the fact that the neuroprotective effect of the selective JNK3 inhibitor IQ-1S and its ability to suppress the development of neurodegenerative processes in OXYS rats were associated with a decrease in the phosphorylation levels of JNK3, c-Jun, APP, and Tau in the hippocampus.

c-Jun N-terminal kinase signaling in aging

Aging encompasses a wide array of detrimental effects that compromise physiological functions, elevate the risk of chronic diseases, and impair cognitive abilities. However, the precise underlying mechanisms, particularly the involvement of specific molecular regulatory proteins in the aging process, remain insufficiently understood. Emerging evidence indicates that c-Jun N-terminal kinase (JNK) serves as a potential regulator within the intricate molecular clock governing aging-related processes. JNK demonstrates the ability to diminish telomerase reverse transcriptase activity, elevate β-galactosidase activity, and induce telomere shortening, thereby contributing to immune system aging. Moreover, the circadian rhythm protein is implicated in JNK-mediated aging. Through this comprehensive review, we meticulously elucidate the intricate regulatory mechanisms orchestrated by JNK signaling in aging processes, offering unprecedented molecular insights with significant implications and highlighting potential therapeutic targets. We also explore the translational impact of targeting JNK signaling for interventions aimed at extending healthspan and promoting longevity.

Advanced Research in Age-Related Macular Degeneration: Special Issue

Age-related macular degeneration (AMD) is an eye disease that is the leading cause of irreversible vision loss in people over 55 years of age [...].

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.