Neuronal-Glial Interaction in a Triple-Transgenic Mouse Model of Alzheimer's Disease: Gene Ontology and Lithium Pathways

Human brain 7Li-MRI following low-dose lithium dietary supplementation in healthy participants

BACKGROUND

Lithium is an effective mood stabiliser, but its mechanism of action is incompletely defined. Even at very low doses, lithium may have neuroprotective effects, but it is not clear if these relate to brain lithium concentration in vivo. We have developed magnetic resonance imaging (7Li-MRI) methods to detect lithium in the brain following supplementation at a very low dose.

METHODS

Lithium orotate supplements were taken by nine healthy adult male subjects (5 mg daily) for up to 28 days, providing 2-7 % of the lithium content of a typical therapeutic lithium carbonate dose. One-dimensional 7Li-images were acquired on a 3.0 T MRI scanner. All subjects were scanned on day 14 or 28; seven were scanned on both, one at baseline and one after 7-days washout.

RESULTS

7Li-MR signal amplitude was broadly stable between days 14 and 28. Two subjects had notably higher 7Li-signal intensities (approximately 2-4×) compared to other study participants.

LIMITATIONS

Lithium adherence was self-reported by all participants without formal validation. The coarse spatial resolution necessary for detection of low concentrations of 7Li exhibits imperfect spatial separation of signal from adjacent pixels.

CONCLUSIONS

7Li-MRI performed using a clinical 3T scanner demonstrated detection of lithium in the brain at very low concentration, in the range of approximately 10-60 mM. The methods are suited to studies assessing low dose lithium administration in psychiatric and neurodegenerative disorders, and permit the comparison of different lithium salt preparations at a time of emerging interest in the field.

Lithium and disease modification: A systematic review and meta-analysis in Alzheimer's and Parkinson's disease

The role of lithium as a possible therapeutic strategy for neurodegenerative diseases has generated scientific interest. We systematically reviewed and meta-analyzed pre-clinical and clinical studies that evidenced the neuroprotective effects of lithium in Alzheimer's (AD) and Parkinson's disease (PD). We followed the PRISMA guidelines and performed the systematic literature search using PubMed, EMBASE, Web of Science, and Cochrane Library. A total of 32 articles were identified. Twenty-nine studies were performed in animal models and 3 studies were performed on human samples of AD. A total of 17 preclinical studies were included in the meta-analysis. Our analysis showed that lithium treatment has neuroprotective effects in diseases. Lithium treatment reduced amyloid-β and tau levels and significantly improved cognitive behavior in animal models of AD. Lithium increased the tyrosine hydroxylase levels and improved motor behavior in the PD model. Despite fewer clinical studies on these aspects, we evidenced the positive effects of lithium in AD patients. This study lends further support to the idea of lithium's therapeutic potential in neurodegenerative diseases.

Lithium Prevents Telomere Shortening in Cortical Neurons in Amyloid-Beta Induced Toxicity

Background: There is consistent evidence of the potential benefits of lithium attenuating mechanisms of neurodegeneration, including those related to the pathophysiology of Alzheimer’s disease (AD), and facilitating neurotrophic and protective responses, including maintenance of telomere length. The aim was to investigate the protective effect of the pre-treatment with lithium on amyloid-beta (Aβ)-induced toxicity and telomere length in neurons. Methods: Cortical neurons were treated with lithium chloride at therapeutic and subtherapeutic concentrations (2 mM, 0.2 mM and 0.02 mM) for seven days. Amyloid toxicity was induced 24 h before the end of lithium treatment. Results: Lithium resulted in 120% (2 mM), 180% (0.2 mM) and 140% (0.02 mM) increments in telomere length as compared to untreated controls. Incubation with Aβ1-42 was associated with significant reductions in MTT uptake (33%) and telomere length (83%) as compared to controls. Conclusions: Lithium prevented loss of culture viability and telomere shortening in neuronal cultures challenged with Aβ fibrils.

Inhibition of Insulin Degrading Enzyme to Control Diabetes Mellitus and its Applications on some Other Chronic Disease: a Critical Review

PURPOSE

This review aims to provide a precise perceptive of the insulin-degrading enzyme (IDE) and its relationship to type 2 diabetes (T2D), Alzheimer's disease (AD), obesity, and cardiovascular diseases. The purpose of the current study was to provide clear idea of treating prevalent diseases such as T2D, and AD by molecular pharmacological therapeutics rather than conventional medicinal therapy.

METHODS

To achieve the aims, molecular docking was performed using several softwares such as LIGPLOT+, Python, and Protein-Ligand Interaction Profiler with corresponding tools.

RESULTS

The IDE is a large zinc-metalloprotease that breakdown numerous pathophysiologically important extracellular substrates, comprising amyloid β-protein (Aβ) and insulin. Recent studies demonstrated that dysregulation of IDE leads to develop AD and T2D. Specifically, IDE regulates circulating insulin in a variety of organs via a degradation-dependent clearance mechanism. IDE is unique because it was subjected to allosteric activation and mediated via an oligomer structure.

CONCLUSION

In this review, we summarised the factors that modulate insulin reformation by IDE and interaction of IDE and some recent reports on IDE inhibitors against AD and T2D. We also highlighted the latest signs of progress of the function of IDE and challenges in advancing IDE- targetted therapies against T2D and AD.

Lithium modulates multiple tau kinases with distinct effects in cortical and hippocampal neurons according to concentration ranges

The hyperphosphorylation of tau is a central mechanism in the pathogenesis of Alzheimer's disease (AD). Lithium is a potent inhibitor of glycogen synthase kinase-3beta (GSK3β), the most important tau kinase in neurons, and may also affect tau phosphorylation by modifying the expression and/or activity of other kinases, such as protein kinase A (PKA), Akt (PKB), and calcium calmodulin kinase-II (CaMKII). The aim of the present study is to determine the effect of chronic lithium treatment on the protein expression of tau and its major kinases in cortical and hippocampal neurons, at distinct working concentrations. Primary cultures of cortical and hippocampal neurons were treated with sub-therapeutic (0.02 mM and 0.2 mM) and therapeutic (2 mM) concentrations of lithium for 7 days. Protein expression of tau and tau-kinases was determined by immunoblotting. An indirect estimate of GSK3β activity was determined by the GSK3β ratio (rGSKβ). Statistically significant increments in the protein expression of tau and CaMKII were observed both in cortical and hippocampal neurons treated with subtherapeutic doses of lithium. GSK3β activity was increased in cortical, but decreased in hippocampal neurons. Distinct patterns of changes in the expression of the remaining tau tau-kinases were observed: in cortical neurons, lithium treatment was associated with consistent decrements in Akt and PKA, whereas hippocampal neurons displayed increased protein expression of Akt and decreased PKA. Our results suggest that chronic lithium treatment may yield distinct biological effects depending on the concentration range, with regional specificity. We further suggest that hippocampal neurons may be more sensitive to the effect of lithium, presenting with changes in the expression of tau-related proteins at subtherapeutic doses, which may not be mirrored by the effects observed in cortical neurons.

Markers of Neuroinflammation and Apoptosis in the Temporal Lobe of Patients with Drug-Resistant Epilepsy

Abstract

Current antiepileptic strategies aim to normalize the interaction of the excitatory and inhibitory systems, which is ineffective in treating patients with drug-resistant epilepsy. Neuroinflammatory processes in the epileptic focus and its perifocal area can trigger apoptosis and also contribute to the development of drug resistance. The level of pro- and anti-apoptotic proteins (p-NF-kB, TNF-α, p53, FAS, caspase-3, caspase-9) was analyzed in intraoperative biopsies of the temporal lobe gray and white matter in the brain of patients with drug-resistant epilepsy. An increased level of pro-apoptotic proteins was revealed in the cortex and perifocal area’s white matter against the background of an imbalance of protective anti-apoptotic proteins. It appears that the activation of the extrinsic pathway of apoptosis occurs in the perifocal area, while in the epileptic focus, there are proteins responsible for the activation of the anti-apoptotic survival pathways. Active neuroinflammation in the epileptic focus and perifocal area of the temporal lobe may contribute to the development of the resistance to antiepileptic drugs and the progression of neurodegeneration in such patients.

Mitochondrial dysfunction in Alzheimer's disease: Therapeutic implications of lithium

Alzheimer's disease (AD) is one of the most prevalent neurodegenerative diseases, characterized by the accumulation of abnormal tau proteins within neurons and amyloid plaques in the brain parenchyma, which leads to progressive loss of neurons in the brain. While the detailed mechanism of the pathogenesis of AD is still unknown, evidence suggests that mitochondrial dysfunction likely plays a fundamental role in the pathogenesis of this disease. Due to the relevance of mitochondrial alterations in AD, recent works have suggested the therapeutic potential of mitochondrial-targeted lithium. Lithium has been shown to possess neuroprotective and neurotrophic properties that could also be related to the upregulation of mitochondrial function. In the current work, we perform a comprehensive investigation of the significance of mitochondrial dysfunction in AD and pharmacological treatment with lithium as imperative in this pathology, through a brief review of the major findings on the effects of lithium as a therapeutic approach targeting mitochondria in the context of AD.