Wave-Like Dose-Dependence of the Stimulating Effects of Dimebon on Cognition in a Wide Dose Range

Advancements in autophagy perturbations in Alzheimer's disease: Molecular aspects and therapeutics

Emerging evidences suggest that autophagy, a key cellular process responsible for degrading and recycling damaged organelles and proteins, plays a crucial role in maintaining neuronal health. Dysfunctional autophagy has been linked to the pathogenesis of Alzheimer's disease (AD), contributing to the accumulation of misfolded proteins and cellular debris. Molecular mechanisms underlying autophagy dysfunction in AD involve amyloid-beta (Aβ) and tau accumulation, neuroinflammation, mitochondrial dysfunction, oxidative stress and endoplasmic reticulum stress. Disrupted signaling pathways such as TRIB3, Nmnat and BAG3 that regulate key processes like autophagosome initiation, lysosome function, and protein homeostasis also play a crucial role in the pathogenesis. Restoration of autophagy by modulating these molecular and signaling pathways may be an effective therapeutic strategy for AD. Studies have found few drugs targeting autophagy dysregulation in AD. These drugs include metformin that has been found to modulate the expression of TRIB3 for autophagy regulation. Another drug, resveratrol has been reported to augment the activity of Nmnat thus, increases autophagy flux. BACE1 and mTOR inhibitors like arctigenin, nilvadipine and dapagliflozin were also found to restore autophagy. This study elaborates recent advances in signaling and molecular pathways and discusses current and emerging therapeutic interventions targeting autophagy dysfunction in AD.

Mitochondrial dysfunction and neurological disorders: A narrative review and treatment overview

Mitochondria play a vital role in the nervous system, as they are responsible for generating energy in the form of ATP and regulating cellular processes such as calcium (Ca2+) signaling and apoptosis. However, mitochondrial dysfunction can lead to oxidative stress (OS), inflammation, and cell death, which have been implicated in the pathogenesis of various neurological disorders. In this article, we review the main functions of mitochondria in the nervous system and explore the mechanisms related to mitochondrial dysfunction. We discuss the role of mitochondrial dysfunction in the development and progression of some neurological disorders including Parkinson's disease (PD), multiple sclerosis (MS), Alzheimer's disease (AD), depression, and epilepsy. Finally, we provide an overview of various current treatment strategies that target mitochondrial dysfunction, including pharmacological treatments, phototherapy, gene therapy, and mitotherapy. This review emphasizes the importance of understanding the role of mitochondria in the nervous system and highlights the potential for mitochondrial-targeted therapies in the treatment of neurological disorders. Furthermore, it highlights some limitations and challenges encountered by the current therapeutic strategies and puts them in future perspective.

Recent Advances in Molecular Pathways and Therapeutic Implications Targeting Mitochondrial Dysfunction for Alzheimer's Disease

Alzheimer's disease (AD) is a neurodegenerative disorder which leads to mental deterioration due to aberrant accretion of misfolded proteins in the brain. According to mitochondrial cascade hypothesis, mitochondrial dysfunction is majorly involved in the pathogenesis of AD. Many drugs targeting mitochondria to treat and prevent AD are in different phases of clinical trials for the evaluation of safety and efficacy as mitochondria are involved in various cellular and neuronal functions. Mitochondrial dynamics is regulated by fission and fusion processes mediated by dynamin-related protein (Drp1). Inner membrane fusion takes place by OPA1 and outer membrane fusion is facilitated by mitofusin1 and mitofusin2 (Mfn1/2). Excessive calcium release also impairs mitochondrial functions; to overcome this, calcium channel blockers like nilvadipine are used. Another process acting as a regulator of mitochondrial function is mitophagy which is involved in the removal of damaged and non-functional mitochondria however this process is also altered in AD due to mutations in Presenilin1 (PS1) and Amyloid Precursor Protein (APP) gene. Mitochondrial dynamics is altered in AD which led to the discovery of various fission protein (like Drp1) inhibitors and drugs that promote fusion. Modulations in AMPK, SIRT1 and Akt pathways can also come out to be better therapeutic strategies as these pathways regulate functions of mitochondria. Oxidative phosphorylation is major generator of Reactive Oxygen Species (ROS) leading to mitochondrial damage; therefore reduction in production of ROS by using antioxidants like MitoQ, Curcumin and Vitamin Eis quiteeffective.