Intracellular pathways underlying the effects of lithium

Anti-oxidative stress and cognitive improvement of a semi-synthetic isoorientin-based GSK-3β inhibitor in rat pheochromocytoma cell PC12 and scopolamine-induced AD model mice via AKT/GSK-3β/Nrf2 pathway

BACKGROUND

Alzheimer's disease (AD) is a neurodegenerative disease characterized by progressive cognitive deficits. Although the pathogenesis of AD is unclear, oxidative stress has been implicated to play a dominant role in its development. The flavonoid isoorientin (ISO) and its synthetic derivatives TFGF-18 selectively inhibit glycogen synthase kinase-3β (GSK-3β), a potential target of AD treatment.

PURPOSE

To investigate the neuroprotective effect of TFGF-18 against oxidative stress via the GSK-3β pathway in hydrogen peroxide (H2O2)-induced rat pheochromocytoma PC12 cells in vitro and scopolamine (SCOP)-induced AD mice in vivo.

METHOD

The oxidative stress of PC12 cells was induced by H2O2 (600 μM) and the effects of TFGF-18 (2 and 8 μM) or ISO (12.5 and 50 μM) were observed. The AD mouse model was induced by SCOP (3 mg/kg), and the effects of TFGF-18 (2 and 8 mg/kg), ISO (50 mg/kg), and donepezil (DNP) (3 mg/kg) were observed. DNP, a currently accepted drug for AD was used as a positive control. The neuronal cell damages were analyzed by flow cytometry, LDH assay, JC-1 assay and Nissl staining. The oxidative stress was evaluated by the detection of MDA, SOD, GPx and ROS. The level of ACh, and the activity of AChE, ChAT were detected by the assay kit. The expressions of Bax, Bcl-2, caspase3, cleaved-caspase3, p-AKT (Thr308), AKT, p-GSK-3β (Ser9), GSK-3β, Nrf2, and HO-1, as well as p-CREB (Ser133), CREB, and BDNF were analyzed by western blotting. Morris water maze test was performed to analyze learning and memory ability.

RESULTS

TFGF-18 inhibited neuronal damage and the expressions of Bax, caspase3 and cleaved-caspase3, and increased the expression of Bcl-2 in vitro and in vivo. The level of MDA and ROS were decreased while the activities of SOD and GPx were increased by TFGF-18. Moreover, TFGF-18 increased the p-AKT, p-GSK-3β (Ser9), Nrf2, HO-1, p-CREB, and BDNF expression reduced by H2O2 and SCOP. Meanwhile, MK2206, an AKT inhibitor, reversed the effect of TFGF-18 on the AKT/GSK-3β pathway. In addition, the cholinergic system (ACh, ChAT, and AChE) disorders were retrained and the learning and memory impairments were prevented by TFGF-18 in SCOP-induced AD mice.

CONCLUSIONS

TFGF-18 protects against neuronal cell damage and cognitive impairment by inhibiting oxidative stress via AKT/GSK-3β/Nrf2 pathway.

Neuroprotection of isoorientin against microglia activation induced by lipopolysaccharide via regulating GSK3β, NF-κb and Nrf2/HO-1 pathways

Background: Isoorientin (ISO), a flavone C-glycoside, is a glycogen synthase kinase 3β (GSK3β) substrate-competitive inhibitor. ISO has potential in treatment of Alzheimer's disease (AD). An excessive activation of GSK3β can lead to neuroinflammation causing neuronal damage. Microglia cells, as resident immune cells of the central nervous system, mediate neuroinflammation. Here, we studied the effects of ISO on microglial activation to alleviate neuroinflammation.

Methods: Effects of ISO were observed upon the stimulation of mouse microglia BV2 or SIM-A9 cells by lipopolysaccharide (LPS). Lithium chloride (LiCl) was the positive control as a GSK3β inhibitor. The release of TNF-α and NO were analyzed by ELISA and Griess assays, while expressions of COX-2, Iba-1, BDNF, GSK3β, NF-κB p65, IκB, Nrf2 and HO-1 were detected by Western blotting. In the co-culture model of SIM-A9 cells and differentiated SH-SY5Y human neuroblastoma cells, effects of ISO on microglia-mediated neuronal damage were evaluated with the MTS assay.

Results: ISO significantly inhibited the production of TNF-α (p < 0.01), NO (p < 0.001) and the expression of COX-2 (p < 0.01) and Iba-1 (p < 0.05) induced by LPS, and increased BDNF. The cell viability of SH-SY5Y was inhibited by LPS in the co-culture, which was prevented by ISO pretreatment. ISO increased the expression of p-GSK3β (Ser9), IκB and HO-1 in the cytoplasm, decreased NF-κB p65 and increased Nrf2 in the nucleus compared with the LPS group.

Conclusion: ISO attenuated the activation of microglia through regulating the GSK3β, NF-κB and Nrf2/HO-1 signaling pathways to exert neuroprotection.

GSK3β Substrate-competitive Inhibitors Regulate the gut Homeostasis and Barrier Function to Inhibit Neuroinflammation in Scopolamine-induced Alzheimer's Disease Model Mice

Alzheimer's disease (AD) is a neurodegenerative disease mainly characterized by cognitive impairment. Glycogen synthase kinase 3 (GSK3β) is a potential therapeutic target against AD. Isoorientin (ISO), a GSK3β substrate competitive inhibitor, plays anti-AD effects in in vitro and in vivo AD model. TFGF-18 is an ISO synthetic analog with improved potency, but its neuroprotective effect in vivo remains to be elucidated, and the underlying mechanisms of GSK3β inhibitor against AD need to be clarified. This study investigated the TFGF-18 and ISO effects on gut homeostasis and neuroinflammation in scopolamine (SCOP)-induced AD mice. And the protection on barrier function was observed in in vitro blood-brain barrier (BBB) model of mouse brain microvascular endothelial cells (bEnd.3). The results show that TFGF-18 and ISO improved cognitive function in SCOP-induced mice, and inhibited cholinergic system disorders and inflammation in the brain and intestine, decreased the level of lipopolysaccharides (LPS) in serum and intestine, protected the diversity and balance of intestinal microbiome, increased the expressions of tight junction protein (ZO-1, occludin), brain derived neurotrophic factor (BDNF) and glial cell-derived neurotrophic factor (GDNF) in the mouse brain and intestine. In addition, TFGF-18 and ISO protected against barrier damage in LPS-stimulated BBB model of bEnd.3 cells in vitro. TFGF-18 and ISO increased the ratio of p-GSK3β/GSK3β, suppressed toll-like receptors 4 (TLR-4) expression and nuclear factor kappa-B (NF-κB) activation in vivo and in vitro, and increased the expressions of β-catenin, nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) in vitro. In conclusion, The GSK3β inhibitors TFGF-18 and ISO modulate the gut homeostasis and barrier function to inhibit neuroinflammation and attenuate cognitive impairment by regulating NF-κB, β-catenin and Nrf2/HO-1 pathways.

New Advances in the Pharmacology and Toxicology of Lithium: A Neurobiologically Oriented Overview

Over the last six decades, lithium has been considered the gold standard treatment for the long-term management of bipolar disorder due to its efficacy in preventing both manic and depressive episodes as well as suicidal behaviors. Nevertheless, despite numerous observed effects on various cellular pathways and biologic systems, the precise mechanism through which lithium stabilizes mood remains elusive. Furthermore, there is recent support for the therapeutic potential of lithium in other brain diseases. This review offers a comprehensive examination of contemporary understanding and predominant theories concerning the diverse mechanisms underlying lithium's effects. These findings are based on investigations utilizing cellular and animal models of neurodegenerative and psychiatric disorders. Recent studies have provided additional support for the significance of glycogen synthase kinase-3 (GSK3) inhibition as a crucial mechanism. Furthermore, research has shed more light on the interconnections between GSK3-mediated neuroprotective, antioxidant, and neuroplasticity processes. Moreover, recent advancements in animal and human models have provided valuable insights into how lithium-induced modifications at the homeostatic synaptic plasticity level may play a pivotal role in its clinical effectiveness. We focused on findings from translational studies suggesting that lithium may interface with microRNA expression. Finally, we are exploring the repurposing potential of lithium beyond bipolar disorder. These recent findings on the therapeutic mechanisms of lithium have provided important clues toward developing predictive models of response to lithium treatment and identifying new biologic targets. SIGNIFICANCE STATEMENT: Lithium is the drug of choice for the treatment of bipolar disorder, but its mechanism of action in stabilizing mood remains elusive. This review presents the latest evidence on lithium's various mechanisms of action. Recent evidence has strengthened glycogen synthase kinase-3 (GSK3) inhibition, changes at the level of homeostatic synaptic plasticity, and regulation of microRNA expression as key mechanisms, providing an intriguing perspective that may help bridge the mechanistic gap between molecular functions and its clinical efficacy as a mood stabilizer.

Effects of lithium isotopes on sodium/lithium co-transport and calcium efflux through the sodium/calcium/lithium exchanger in mitochondria

The effects of lithium (Li) isotopes and their impact on biological processes have recently gained increased attention due to the significance of Li as a pharmacological agent and the potential that Li isotopic effects in neuroscience contexts may constitute a new example of quantum effects in biology. Previous studies have shown that the two Li isotopes, which differ in mass and nuclear spin, have unusual different effects in vivo and in vitro and, although some molecular targets for Li isotope fractionation have been proposed, it is not known whether those result in observable downstream neurophysiological effects. In this work we studied fluxes of Li+, sodium (Na+) and calcium (Ca2+) ions in the mitochondrial sodium/calcium/lithium exchanger (NCLX), the only transporter known with recognized specificity for Li+. We studied the effect of Li+ isotopes on Ca2+ efflux from heart mitochondria in comparison to natural Li+ and Na+ using Ca2+-induced fluorescence and investigated a possible Li isotope fractionation in mitochondria using inductively coupled plasma mass spectrometry (ICP-MS). Our fluorescence data indicate that Ca2+ efflux increases with higher concentrations of either Li+ or Na+. We found that the simultaneous presence of Li+ and Na+ increases Ca2+ efflux compared to Ca2+ efflux caused by the same concentration of Li+ alone. However, no differentiation in the Ca2+ efflux between the two Li+ isotopes was observed, either for Li+ alone or in mixtures of Li+ and Na+. Our ICP-MS data demonstrate that there is selectivity between Na+ and Li+ (greater Na+ than Li+ uptake) and, most interestingly, between the Li+ isotopes (greater 6Li+ than 7Li+ uptake) by the inner mitochondrial membrane. In summary, we observed no Li+ isotope differentiation for Ca2+ efflux in mitochondria via NCLX but found a Li+ isotope fractionation during Li+ uptake by mitochondria with NCLX active or blocked. Our results suggest that the transport of Li+ via NCLX is not the main pathway for Li+ isotope fractionation and that this differentiation does not affect Ca2+ efflux in mitochondria. Therefore, explaining the puzzling effects of Li+ isotopes observed in other contexts will require further investigation to identify the molecular targets for Li+ isotope differentiation.

Lithium: effects in animal models of vanishing white matter are not promising

Vanishing white matter (VWM) is a devastating autosomal recessive leukodystrophy, resulting in neurological deterioration and premature death, and without curative treatment. Pathogenic hypomorphic variants in subunits of the eukaryotic initiation factor 2B (eIF2B) cause VWM. eIF2B is required for regulating the integrated stress response (ISR), a physiological response to cellular stress. In patients' central nervous system, reduced eIF2B activity causes deregulation of the ISR. In VWM mouse models, the extent of ISR deregulation correlates with disease severity. One approach to restoring eIF2B activity is by inhibition of GSK3β, a kinase that phosphorylates eIF2B and reduces its activity. Lithium, an inhibitor of GSK3β, is thus expected to stimulate eIF2B activity and ameliorate VWM symptoms. The effects of lithium were tested in zebrafish and mouse VWM models. Lithium improved motor behavior in homozygous eif2b5 mutant zebrafish. In lithium-treated 2b4he2b5ho mutant mice, a paradoxical increase in some ISR transcripts was found. Furthermore, at the dosage tested, lithium induced significant polydipsia in both healthy controls and 2b4he2b5ho mutant mice and did not increase the expression of other markers of lithium efficacy. In conclusion, lithium is not a drug of choice for further development in VWM based on the limited or lack of efficacy and significant side-effect profile.

Low-dose lithium adjunct to quetiapine improves cognitive task performance in mice with MK801-induced long-term cognitive impairment: Evidence from a pilot study

BACKGROUND

Low-dose lithium (LD-Li) has been shown to rescue cognitive impairment in mouse models of short-term mild cognitive impairment, dementia, and schizophrenia. However, few studies have characterized the effects of LD-Li, alone or in conjunction with anti-psychotics, in the mouse model of MK801-induced long term cognitive impairment.

METHODS

The present study used in vivo Ca2+ imaging and a battery of cognitive function assessments to investigate the long-term effects of LD-Li on cognition in mice exposed to repeated injections of MK801. Prefrontal Ca2+ activity was visualized to estimate alterations in neural activity in the model mice. Pre-pulse inhibition (PPI), novel object recognition (NOR), Morris water maze (MWM), and fear conditioning (FC) tasks were used to characterize cognitive performance; open field activity (OFA) testing was used to observe psychotic symptoms. Two treatment strategies were tested: LD-Li [250 mg/d human equivalent dose (HED)] adjunct to quetiapine (QTP; 600 mg/d HED); and QTP-monotherapy (mt; 600 mg/d HED).

RESULTS

Compared to the QTP-mt group, the LD-Li + QTP group showed greatly improved cognitive performance on all measures between experimental days 29 and 85. QTP-mt improved behavioral measures compared to untreated controls, but the effects persisted only from day 29 to day 43. These data suggest that LD-Li + QTP is superior to QTP-mt for improving long-term cognitive impairments in the MK801 mouse model.

LIMITATIONS

There is no medical consensus regarding lithium use in patients with schizophrenia.

CONCLUSION

More pre-clinical and clinical studies are needed to further investigate effective treatment strategies for patients with long-term cognitive impairments, such as chronic schizophrenia.

Safety and efficacy of lithium in patients with amyotrophic lateral sclerosis: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVES

This study provides a systematic review and meta-analysis of randomized controlled trials (RCTs) investigating the safety and efficacy of lithium in amyotrophic lateral sclerosis (ALS) patients.

METHODS

PubMed, Web of Science, Cochrane CENTRAL, Scopus, and Your Journals@Ovid were searched up to 9 December 2022. RCTs investigating lithium, either alone or with any supplement, in ALS patients were included. Meta-analysis was performed using RevMan and results are presented in forest plot.

RESULTS

Four RCTs with 469 patients met the inclusion criteria and were included in our study. Lithium doses varied among the included studies and one study used a combined therapy of lithium with valproate. Meta-analysis showed no difference between lithium and placebo regarding severe adverse events (odds ratio = 1.13, 95% confidence interval: 0.73 to 1.75, P = 0.58). No significant differences were observed with regard to survival rate between the two groups (hazard ratio = 0.95, 95% confidence interval: 0.65 to 1.37, P = 0.77). There were also no significant differences between the two groups with regard to average changes of revised amyotrophic lateral sclerosis functional rating scale (P = 0.35) and forced vital capacity percentage predicted (P = 0.73). Subgroup analysis showed no significant differences regarding all investigated outcomes either for lithium alone or lithium with valproate.

CONCLUSION

Current evidence suggests a safety profile with no benefit of lithium for ALS. However, given the limited number of RCTs and the safety findings, we recommend further well-designed RCTs to investigate lithium and valproate in ALS patients.

Lithium engages autophagy for neuroprotection and neuroplasticity: translational evidence for therapy

Here an overview is provided on therapeutic/neuroprotective effects of Lithium (Li⁺) in neurodegenerative and psychiatric disorders focusing on the conspicuous action of Li⁺ through autophagy. The effects on the autophagy machinery remain the key molecular mechanisms to explain the protective effects of Li⁺ for neurodegenerative diseases, offering potential therapeutic strategies for the treatment of neuropsychiatric disorders and emphasizes a crossroad linking autophagy, neurodegenerative disorders, and mood stabilization. Sensitization by psychostimulants points to several mechanisms involved in psychopathology, most also crucial in neurodegenerative disorders. Evidence shows the involvement of autophagy and metabotropic Glutamate receptors-5 (mGluR5) in neurodegeneration due to methamphetamine neurotoxicity as well as in neuroprotection, both in vitro and in vivo models. More recently, Li⁺ was shown to modulate autophagy through its action on mGluR5, thus pointing to an additional way of autophagy engagement by Li⁺ and to a substantial role of mGluR5 in neuroprotection related to neural e neuropsychiatry diseases. We propose Li⁺ engagement of autophagy through the canonical mechanisms of autophagy machinery and through the intermediary of mGluR5.

Is lithium neuroprotective? An updated mechanistic illustrated review

Neurodegeneration is a pathological process characterized by progressive neuronal impairment, dysfunction, and loss due to mitochondrial dysfunction, oxidative stress, inflammation, and apoptosis. Many studies have shown that lithium protects against neurodegeneration. Herein, we summarize recent clinical and laboratory studies on the neuroprotective effects of lithium against neurodegeneration and its potential to modulate mitochondrial dysfunction, oxidative stress, inflammation, and apoptosis. Recent findings indicate that lithium regulates critical intracellular pathways such as phosphatidylinositol-3 (PI3)/protein kinase B (Akt)/glycogen synthase kinase-3 (GSK3β) and PI3/Akt/response element-binding protein (CREB)/brain-derived neurotrophic factor (BDNF). We queried PubMed, Web of Science, Scopus, Elsevier, and other related databases using search terms related to lithium and its neuroprotective effect in various neurodegenerative diseases and events from January 2000 to May 2022. We reviewed the major findings and mechanisms proposed for the effects of lithium. Lithium's neuroprotective potential against neural cell degeneration is mediated by inducing anti-inflammatory factors, antioxidant enzymes, and free radical scavengers to prevent mitochondrial dysfunction. Lithium effects are regulated by two essential pathways: PI3/Akt/GSK3β and PI3/Akt/CREB/BDNF. Lithium acts as a neuroprotective agent against neurodegeneration by preventing inflammation, oxidative stress, apoptosis, and mitochondrial dysfunction using PI3/Akt/GSK3β and PI3/Akt/CREB/BDNF signaling pathways.

Mechanistic Insights and Potential Therapeutic Approaches in PolyQ Diseases via Autophagy

Polyglutamine diseases are a group of congenital neurodegenerative diseases categorized with genomic abnormalities in the expansion of CAG triplet repeats in coding regions of specific disease-related genes. Protein aggregates are the toxic hallmark for polyQ diseases and initiate neuronal death. Autophagy is a catabolic process that aids in the removal of damaged organelles or toxic protein aggregates, a process required to maintain cellular homeostasis that has the potential to fight against neurodegenerative diseases, but this pathway gets affected under diseased conditions, as there is a direct impact on autophagy-related gene expression. The increase in the accumulation of autophagy vesicles reported in neurodegenerative diseases was due to an increase in autophagy or may have been due to a decrease in autophagy flux. These reports suggested that there is a contribution of autophagy in the pathology of diseases and regulation in the process of autophagy. It was demonstrated in various disease models of polyQ diseases that autophagy upregulation by using modulators can enhance the dissolution of toxic aggregates and delay disease progression. In this review, interaction of the autophagy pathway with polyQ diseases was analyzed, and a therapeutic approach with autophagy inducing drugs was established for disease pathogenesis.

GSK3β as a novel promising target to overcome chemoresistance in pancreatic cancer

Pancreatic cancer is an aggressive malignancy with increasing incidence and poor prognosis due to its late diagnosis and intrinsic chemoresistance. Most pancreatic cancer patients present with locally advanced or metastatic disease characterized by inherent resistance to chemotherapy. These features pose a series of therapeutic challenges and new targets are urgently needed. Glycogen synthase kinase 3 beta (GSK3β) is a conserved serine/threonine kinase, which regulates key cellular processes including cell proliferation, DNA repair, cell cycle progression, signaling and metabolic pathways. GSK3β is implicated in non-malignant and malignant diseases including inflammation, neurodegenerative diseases, diabetes and cancer. GSK3β recently emerged among the key factors involved in the onset and progression of pancreatic cancer, as well as in the acquisition of chemoresistance. Intensive research has been conducted on key oncogenic functions of GSK3β and its potential as a druggable target; currently developed GSK3β inhibitors display promising results in preclinical models of distinct tumor types, including pancreatic cancer. Here, we review the latest findings about GSK-3β biology and its role in the development and progression of pancreatic cancer. Moreover, we discuss therapeutic agents targeting GSK3β that could be administered as monotherapy or in combination with other drugs to surmount chemoresistance. Several studies are also defining potential gene signatures to identify patients who might benefit from GSK3β-based therapeutic intervention. This detailed overview emphasizes the urgent need of additional molecular studies on the impact of GSK3β inhibition as well as structural analysis of novel compounds and omics studies of predictive biomarkers.

Translational evidence for lithium-induced brain plasticity and neuroprotection in the treatment of neuropsychiatric disorders

Increasing evidence indicates lithium (Li+) efficacy in neuropsychiatry, pointing to overlapping mechanisms that occur within distinct neuronal populations. In fact, the same pathway depending on which circuitry operates may fall in the psychiatric and/or neurological domains. Li+ restores both neurotransmission and brain structure unveiling that psychiatric and neurological disorders share common dysfunctional molecular and morphological mechanisms, which may involve distinct brain circuitries. Here an overview is provided concerning the therapeutic/neuroprotective effects of Li+ in different neuropsychiatric disorders to highlight common molecular mechanisms through which Li+ produces its mood-stabilizing effects and to what extent these overlap with plasticity in distinct brain circuitries. Li+ mood-stabilizing effects are evident in typical bipolar disorder (BD) characterized by a cyclic course of mania or hypomania followed by depressive episodes, while its efficacy is weaker in the opposite pattern. We focus here on neural adaptations that may underlie psychostimulant-induced psychotic development and to dissect, through the sensitization process, which features are shared in BD and other psychiatric disorders, including schizophrenia. The multiple functions of Li+ highlighted here prove its exceptional pharmacology, which may help to elucidate its mechanisms of action. These may serve as a guide toward a multi-drug strategy. We propose that the onset of sensitization in a specific BD subtype may predict the therapeutic efficacy of Li+. This model may help to infer in BD which molecular mechanisms are relevant to the therapeutic efficacy of Li+.

Autophagy as a gateway for the effects of methamphetamine: From neurotransmitter release and synaptic plasticity to psychiatric and neurodegenerative disorders

As a major eukaryotic cell clearing machinery, autophagy grants cell proteostasis, which is key for neurotransmitter release, synaptic plasticity, and neuronal survival. In line with this, besides neuropathological events, autophagy dysfunctions are bound to synaptic alterations that occur in mental disorders, and early on, in neurodegenerative diseases. This is also the case of methamphetamine (METH) abuse, which leads to psychiatric disturbances and neurotoxicity. While consistently altering the autophagy machinery, METH produces behavioral and neurotoxic effects through molecular and biochemical events that can be recapitulated by autophagy blockade. These consist of altered physiological dopamine (DA) release, abnormal stimulation of DA and glutamate receptors, as well as oxidative, excitotoxic, and neuroinflammatory events. Recent molecular insights suggest that METH early impairs the autophagy machinery, though its functional significance remains to be investigated. Here we discuss evidence suggesting that alterations of DA transmission and autophagy are intermingled within a chain of events underlying behavioral alterations and neurodegenerative phenomena produced by METH. Understanding how METH alters the autophagy machinery is expected to provide novel insights into the neurobiology of METH addiction sharing some features with psychiatric disorders and parkinsonism.

Medicinal inorganic chemistry: an updated review on the status of metallodrugs and prominent metallodrug candidates

Metallodrugs correspond to a small portion of all available drugs in the market and, yet, some of them are among the most used and important drugs in modern medicine. However, medicinal inorganic chemistry remains an underestimated area within medicinal chemistry and the main reason is the mislead association of metals to toxic agents. Thus, in this review, the potential of medicinal inorganic chemistry in drug designing is highlighted through a description of the current status of metallodrugs and metallodrug candidates in advanced clinical trials. The broad spectrum of application of metal-based drugs in medicine for both therapy and diagnosis is addressed by the extensive list of examples presented herein.

Autophagy status as a gateway for stress-induced catecholamine interplay in neurodegeneration

The catecholamine-containing brainstem nuclei locus coeruleus (LC) and ventral tegmental area (VTA) are critically involved in stress responses. Alterations of catecholamine systems during chronic stress may contribute to neurodegeneration, including cognitive decline. Stress-related catecholamine alterations, while contributing to anxiety and depression, might accelerate neuronal degeneration by increasing the formation of toxic dopamine and norepinephrine by-products. These, in turn, may impair proteostasis within a variety of cortical and subcortical areas. In particular, the molecular events governing neurotransmission, neuroplasticity, and proteostasis within LC and VTA affect a variety of brain areas. Therefore, we focus on alterations of autophagy machinery in these nuclei as a relevant trigger in this chain of events. In fact, these catecholamine-containing areas are mostly prone to autophagy-dependent neurodegeneration. Thus, we propose a dynamic hypothesis according to which stress-induced autophagy alterations within the LC-VTA network foster a cascade towards early neurodegeneration within these nuclei.

Isoorientin Inhibits Inflammation in Macrophages and Endotoxemia Mice by Regulating Glycogen Synthase Kinase 3β

Isoorientin has anti-inflammatory effects; however, the mechanism remains unclear. We previously found isoorientin is an inhibitor of glycogen synthase kinase 3β (GSK3β) in vitro. Overactivation of GSK3β is associated with inflammatory responses. GSK3β is inactivated by phosphorylation at Ser9 (i.e., p-GSK3β). Lithium chloride (LiCl) inhibits GSK3β and also increases p-GSK3β (Ser9). The present study investigated the anti-inflammatory effect and mechanism of isoorientin via GSK3β regulation in lipopolysaccharide- (LPS-) induced RAW264.7 murine macrophage-like cells and endotoxemia mice. LiCl was used as a control. While AKT phosphorylates GSK3β, MK-2206, a selective AKT inhibitor, was used to activate GSK3β via AKT inhibition (i.e., not phosphorylate GSK3β at Ser9). The proinflammatory cytokines TNF-α, IL-6, and IL-1β were detected by ELISA or quantitative real-time PCR, while COX-2 by Western blotting. The p-GSK3β and GSK3β downstream signal molecules, including NF-κB, ERK, Nrf2, and HO-1, as well as the tight junction proteins ZO-1 and occludin were measured by Western blotting. The results showed that isoorientin decreased the production of TNF-α, IL-6, and IL-1β and increased the expression of p-GSK3β in vitro and in vivo, similar to LiCl. Coadministration of isoorientin and LiCl showed antagonistic effects. Isoorientin decreased the expression of COX-2, inhibited the activation of ERK and NF-κB, and increased the activation of Nrf2/HO-1 in LPS-induced RAW264.7 cells. Isoorientin increased the expressions of occludin and ZO-1 in the brain of endotoxemia mice. In summary, isoorientin can inhibit GSK3β by increasing p-GSK3β and regulate the downstream signal molecules to inhibit inflammation and protect the integrity of the blood-brain barrier and the homeostasis in the brain.

Cell-Clearing Systems Bridging Repeat Expansion Proteotoxicity and Neuromuscular Junction Alterations in ALS and SBMA

The coordinated activities of autophagy and the ubiquitin proteasome system (UPS) are key to preventing the aggregation and toxicity of misfold-prone proteins which manifest in a number of neurodegenerative disorders. These include proteins which are encoded by genes containing nucleotide repeat expansions. In the present review we focus on the overlapping role of autophagy and the UPS in repeat expansion proteotoxicity associated with chromosome 9 open reading frame 72 (C9ORF72) and androgen receptor (AR) genes, which are implicated in two motor neuron disorders, amyotrophic lateral sclerosis (ALS) and spinal-bulbar muscular atrophy (SBMA), respectively. At baseline, both C9ORF72 and AR regulate autophagy, while their aberrantly-expanded isoforms may lead to a failure in both autophagy and the UPS, further promoting protein aggregation and toxicity within motor neurons and skeletal muscles. Besides proteotoxicity, autophagy and UPS alterations are also implicated in neuromuscular junction (NMJ) alterations, which occur early in both ALS and SBMA. In fact, autophagy and the UPS intermingle with endocytic/secretory pathways to regulate axonal homeostasis and neurotransmission by interacting with key proteins which operate at the NMJ, such as agrin, acetylcholine receptors (AChRs), and adrenergic beta2 receptors (B2-ARs). Thus, alterations of autophagy and the UPS configure as a common hallmark in both ALS and SBMA disease progression. The findings here discussed may contribute to disclosing overlapping molecular mechanisms which are associated with a failure in cell-clearing systems in ALS and SBMA.

Autophagy in trimethyltin-induced neurodegeneration

Autophagy is a degradative process playing an important role in removing misfolded or aggregated proteins, clearing damaged organelles, such as mitochondria and endoplasmic reticulum, as well as eliminating intracellular pathogens. The autophagic process is important for balancing sources of energy at critical developmental stages and in response to nutrient stress. Recently, autophagy has been involved in the pathophysiology of neurodegenerative diseases although its beneficial (pro-survival) or detrimental (pro-death) role remains controversial. In the present review, we discuss the role of autophagy following intoxication with trimethyltin (TMT), an organotin compound that induces severe hippocampal neurodegeneration associated with astrocyte and microglia activation. TMT is considered a useful tool to study the molecular mechanisms occurring in human neurodegenerative diseases such as Alzheimer's disease and temporal lobe epilepsy. This is also relevant in the field of environmental safety, since organotin compounds are used as heat stabilizers in polyvinyl chloride polymers, industrial and agricultural biocides, and as industrial chemical catalysts.

Brain Volume-Related Polymorphisms of the Glycogen Synthase Kinase-3β Gene and Their Effect on Antidepressant Treatment in Major Depressive Disorder

BACKGROUND

Glycogen synthase kinase-3β (GSK-3β) polymorphisms are known to influence hippocampal brain tissue volume in individuals with major depressive disorder (MDD). However, the effects of the GSK-3β gene single nucleotide polymorphisms (SNPs) in those receiving antidepressant therapy are unknown.

OBJECTIVES

In the present study, we examined the relationship between brain volume-related SNPs of the GSK-3β gene and antidepressant treatment effects in patients with MDD.

METHODS

Paroxetine, fluvoxamine, or milnacipran was administered to 143 Japanese patients with MDD. Two SNPs of the GSK-3β gene (rs6438552 and rs12630592) that influence brain volume in the hippocampus were genotyped. For the primary outcome, the relationship between genetic variations in the SNPs and the percent change in the Hamilton Rating Scale for Depression (HAM-D) score at week 6 was examined. In addition, rs334558, which has been reported repeatedly, was also genotyped.

RESULTS

There was a significant correlation between the two SNPs and the percent change in the HAM-D scores at week 6 (rs6438552 A/A vs. A/G + G/G: p = 0.016; rs12630592 G/G vs. G/T + T/T: p = 0.016). There was high linkage disequilibrium between the rs6438552 and rs12630592 SNPs. The correlation between high therapeutic response over time and the two SNPs were also confirmed (rs6438552 A/A vs. others: p = 0.031; rs12630592 G/G vs. others: p = 0.031).

CONCLUSIONS

Our results suggest that two GSK-3β variants that influence brain volume were associated with changes in the HAM-D scores at week 6 in patients with MDD.

Autophagy-Based Hypothesis on the Role of Brain Catecholamine Response During Stress

Stressful events, similar to abused drugs, significantly affect the homeostatic balance of the catecholamine brain systems while activating compensation mechanisms to restore balance. In detail, norepinephrine (NE)- and dopamine (DA)-containing neurons within the locus coeruleus (LC) and ventral tegmental area (VTA), are readily and similarly activated by psychostimulants and stressful events involving neural processes related to perception, reward, cognitive evaluation, appraisal, and stress-dependent hormonal factors. Brain catecholamine response to stress results in time-dependent regulatory processes involving mesocorticolimbic circuits and networks, where LC-NE neurons respond more readily than VTA-DA neurons. LC-NE projections are dominant in controlling the forebrain DA-targeted areas, such as the nucleus accumbens (NAc) and medial pre-frontal cortex (mPFC). Heavy and persistent coping demand could lead to sustained LC-NE and VTA-DA neuronal activity, that, when persisting chronically, is supposed to alter LC-VTA synaptic connections. Increasing evidence has been provided indicating a role of autophagy in modulating DA neurotransmission and synaptic plasticity. This alters behavior, and emotional/cognitive experience in response to drug abuse and occasionally, to psychological stress. Thus, relevant information to address the role of stress and autophagy can be drawn from psychostimulants research. In the present mini-review we discuss the role of autophagy in brain catecholamine response to stress and its dysregulation. The findings here discussed suggest a crucial role of regulated autophagy in the response and adaptation of LC-NE and VTA-DA systems to stress.

Molecular Mechanisms Linking ALS/FTD and Psychiatric Disorders, the Potential Effects of Lithium

Altered proteostasis, endoplasmic reticulum (ER) stress, abnormal unfolded protein response (UPR), mitochondrial dysfunction and autophagy impairment are interconnected events, which contribute to the pathogenesis of amyotrophic lateral sclerosis (ALS)/frontotemporal dementia (FTD). In recent years, the mood stabilizer lithium was shown to potentially modify ALS/FTD beyond mood disorder-related pathology. The effects of lithium are significant in ALS patients carrying genetic variations in the UNC13 presynaptic protein, which occur in ALS/FTD and psychiatric disorders as well. In the brain, lithium modulates a number of biochemical pathways involved in synaptic plasticity, proteostasis, and neuronal survival. By targeting UPR-related events, namely ER stress, excitotoxicity and autophagy dysfunction, lithium produces plastic effects. These are likely to relate to neuroprotection, which was postulated for mood and motor neuron disorders. In the present manuscript, we try to identify and discuss potential mechanisms through which lithium copes concomitantly with ER stress, UPR and autophagy dysfunctions related to UNC13 synaptic alterations and aberrant RNA and protein processing. This may serve as a paradigm to provide novel insights into the neurobiology of ALS/FTD featuring early psychiatric disturbances.

Phytochemicals Bridging Autophagy Induction and Alpha-Synuclein Degradation in Parkinsonism

Among nutraceuticals, phytochemical-rich compounds represent a source of naturally-derived bioactive principles, which are extensively studied for potential beneficial effects in a variety of disorders ranging from cardiovascular and metabolic diseases to cancer and neurodegeneration. In the brain, phytochemicals produce a number of biological effects such as modulation of neurotransmitter activity, growth factor induction, antioxidant and anti-inflammatory activity, stem cell modulation/neurogenesis, regulation of mitochondrial homeostasis, and counteracting protein aggregation through modulation of protein-folding chaperones and the cell clearing systems autophagy and proteasome. In particular, the ability of phytochemicals in restoring proteostasis through autophagy induction took center stage in recent research on neurodegenerative disorders such as Parkinson’s disease (PD). Indeed, autophagy dysfunctions and α-syn aggregation represent two interdependent downstream biochemical events, which concur in the parkinsonian brain, and which are targeted by phytochemicals administration. Therefore, in the present review we discuss evidence about the autophagy-based neuroprotective effects of specific phytochemical-rich plants in experimental parkinsonism, with a special focus on their ability to counteract alpha-synuclein aggregation and toxicity. Although further studies are needed to confirm the autophagy-based effects of some phytochemicals in parkinsonism, the evidence discussed here suggests that rescuing autophagy through natural compounds may play a role in preserving dopamine (DA) neuron integrity by counteracting the aggregation, toxicity, and prion-like spreading of α-syn, which remains a hallmark of PD.

Emerging therapeutic potential of anti-psychotic drugs in the management of human glioma: A comprehensive review

Despite numerous advancements in the last decade, human gliomas such as astrocytoma and glioblastoma multiforme have the worst prognoses among all cancers. Anti-psychotic drugs are commonly prescribed to treat mental disorders among cancer patients, and growing empirical evidence has revealed their antitumor, anti-metastatic, anti-angiogenic, anti-proliferative, chemo-preventive, and neo-adjuvant efficacies in various in vitro, in vivo, and clinical glioma models. Anti-psychotic drugs have drawn the attention of physicians and researchers owing to their beneficial effects in the prevention and treatment of gliomas. This review highlights data on the therapeutic potential of various anti-psychotic drugs as anti-proliferative, chemopreventive, and anti-angiogenic agents in various glioma models via the modulation of upstream and downstream molecular targets involved in apoptosis, autophagy, oxidative stress, inflammation, and the cell cycle in in vitro and in vivo preclinical and clinical stages among glioma patients. The ability of anti-psychotic drugs to modulate various signaling pathways and multidrug resistance-conferring proteins that enhance the efficacy of chemotherapeutic drugs with low side-effects exemplifies their great potential as neo-adjuvants and potential chemotherapeutics in single or multimodal treatment approach. Moreover, anti-psychotic drugs confer the ability to induce glioma into oligodendrocyte-like cells and neuronal-like phenotype cells with reversal of epigenetic alterations through inhibition of histone deacetylase further rationalize their use in glioma treatment. The improved understanding of anti-psychotic drugs as potential chemotherapeutic drugs or as neo-adjuvants will provide better information for their use globally as affordable, well-tolerated, and effective anticancer agents for human glioma.

Recent Developments in Metal-Based Drugs and Chelating Agents for Neurodegenerative Diseases Treatments

The brain has a unique biological complexity and is responsible for important functions in the human body, such as the command of cognitive and motor functions. Disruptive disorders that affect this organ, e.g. neurodegenerative diseases (NDDs), can lead to permanent damage, impairing the patients' quality of life and even causing death. In spite of their clinical diversity, these NDDs share common characteristics, such as the accumulation of specific proteins in the cells, the compromise of the metal ion homeostasis in the brain, among others. Despite considerable advances in understanding the mechanisms of these diseases and advances in the development of treatments, these disorders remain uncured. Considering the diversity of mechanisms that act in NDDs, a wide range of compounds have been developed to act by different means. Thus, promising compounds with contrasting properties, such as chelating agents and metal-based drugs have been proposed to act on different molecular targets as well as to contribute to the same goal, which is the treatment of NDDs. This review seeks to discuss the different roles and recent developments of metal-based drugs, such as metal complexes and metal chelating agents as a proposal for the treatment of NDDs.

Is There a Role of Autophagy in Depression and Antidepressant Action?

Autophagy has been recognized as evolutionary conserved intracellular pathway that ensures energy, organelle, and protein homeostasis through lysosomal degradation of damaged macromolecules and organelles. It is activated under various stress situations, e.g., food deprivation or proteotoxic conditions. Autophagy has been linked to several diseases, more recently also including stress-related diseases such as depression. A growing number of publications report on the role of autophagy in neurons, also referred to as "neuronal autophagy" on the one hand, and several studies describe effects of antidepressants-or of compounds that exert antidepressant-like actions-on autophagy on the other hand. This minireview highlights the emerging evidence for the involvement of autophagy in the pathology and treatment of depression and discusses current limitations as well as potential avenues for future research.

Leukocyte telomere length in patients with bipolar disorder: An updated meta-analysis and subgroup analysis by mood status

The purpose of the present meta-analysis was to compare leukocyte telomere length (LTL), a proposed marker for cell aging, between patients with bipolar disorder (BD) and healthy controls and explore potential moderators for the LTL difference. We searched for the major research databases up to May 2018 for studies that examined LTL in patients with BD and healthy controls. The effect sizes (ESs) of LTL differences from the included studies were pooled using a random-effects model. Furthermore, we adopted subgroup analysis to investigate whether mood status of BD patients or methods for measuring telomere length may influence such differences. We included 10 studies, with a total of 579 patients and 551 controls, in the current meta-analysis and observed significantly shorter LTL in BD patients compared to control subjects. Such differences were found in studies with patients in all mood statuses and in studies using different methods for measuring telomere length. Late-stage BD patients demonstrated more significant LTL shortening than early-stage BD patients. Our current results support the hypothesis of accelerated aging in BD patients. In the future, further properly controlled longitudinal studies are warranted to determine whether LTL changes with disease status or medication use in BD patients.

A Novel Neuroprotective Mechanism for Lithium That Prevents Association of the p75NTR-Sortilin Receptor Complex and Attenuates proNGF-Induced Neuronal Death In Vitro and In Vivo

Neurotrophins play critical roles in the survival, maintenance and death of neurons. In particular, proneurotrophins have been shown to mediate cell death following brain injury induced by status epilepticus (SE) in rats. Previous studies have shown that pilocarpine-induced seizures lead to increased levels of proNGF, which binds to the p75NTR-sortilin receptor complex to elicit apoptosis. A screen to identify compounds that block proNGF binding and uptake into cells expressing p75 and sortilin identified lithium citrate as a potential inhibitor of proNGF and p75NTR-mediated cell death. In this study, we demonstrate that low, submicromolar doses of lithium citrate effectively inhibited proNGF-induced cell death in cultured neurons and protected hippocampal neurons following pilocarpine-induced SE in vivo. We analyzed specific mechanisms by which lithium citrate afforded neuroprotection and determined that lithium citrate prevented the association and internalization of the p75NTR-sortilin receptor complex. Our results demonstrate a novel mechanism by which low-dose treatments of lithium citrate are effective in attenuating p75NTR-mediated cell death in vitro and in vivo.

Recent advances in the understanding and management of bipolar disorder in adults

This article focuses on some aspects of recent progress in the neurobiology and treatment of bipolar disorder (BD) in adults. A molecular-genetic approach to the etiopathogenesis of the illness resulted in the findings of a genetic overlap between BD and other major psychiatric disorders. Furthermore, a poly-gene-environmental interaction in the development of the illness has been demonstrated. For the management of BD, new drugs with putative mood-stabilizing properties have been introduced in the past two decades. However, none of these can surpass lithium, the prototype mood-stabilizer, still considered the most specific drug for BD. Recent research on lithium, besides providing new data on the neurobiology of BD, has confirmed anti-suicidal, immunomodulatory, and neuroprotective properties of this drug.

mTOR-Dependent Cell Proliferation in the Brain

The mammalian Target of Rapamycin (mTOR) is a molecular complex equipped with kinase activity which controls cell viability being key in the PI3K/PTEN/Akt pathway. mTOR acts by integrating a number of environmental stimuli to regulate cell growth, proliferation, autophagy, and protein synthesis. These effects are based on the modulation of different metabolic pathways. Upregulation of mTOR associates with various pathological conditions, such as obesity, neurodegeneration, and brain tumors. This is the case of high-grade gliomas with a high propensity to proliferation and tissue invasion. Glioblastoma Multiforme (GBM) is a WHO grade IV malignant, aggressive, and lethal glioma. To date, a few treatments are available although the outcome of GBM patients remains poor. Experimental and pathological findings suggest that mTOR upregulation plays a major role in determining an aggressive phenotype, thus determining relapse and chemoresistance. Among several activities, mTOR-induced autophagy suppression is key in GBM malignancy. In this article, we discuss recent evidence about mTOR signaling and its role in normal brain development and pathological conditions, with a special emphasis on its role in GBM.

Evaluation of Se-phenyl-thiazolidine-4-carboselenoate protective activity against oxidative and behavioral stress in the maniac model induced by ouabain in male rats

This study investigates Se-phenyl-thiazolidine-4-carboselenoate (Se-PTC) protective activity against oxidative and behavioral stress in the model of mania induced by ouabain (OUA) in male rats. The compound used was Se-PTC (50mg/kg) and the positive control LiCl (45mg/kg) was administered for intragastric route (i.g.) 30min prior to administration of OUA (10^-5M). OUA was dissolved in artificial cerebrospinal fluid (aCSF) and administered at the 5μl through an intracerebroventricular (i.c.v) cannula. The pretreatment with Se-PTC was effective in preventing the increase in locomotor activity induced by OUA, however the positive control LiCl is capable to block crossing augmentation induced by OUA. Na⁺/K⁺-ATPase activity was significantly reduced in OUA group and the Se-PTC to normalize Na^+/K^+-ATPase activity. Pretreatment with Se-PTC protect against the increase in catalase activity and thiobarbituric acid reactive species (TBARS) content in the brain caused by OUA. Therefore, Se-PTC is effective against OUA-induced hyperactivity and alterations in brain oxidative status of rats.

Personalized Medicine and Resurrected Hopes for the Management of Alzheimer's Disease: A Modular Approach Based on GSK-3β Inhibitors

Alzheimer's disease (AD) is one of the most common neurological disorders with vast reaching worldwide prevalence. Research attempts to decipher what's happening to the human mind have shown that pathogenesis of AD is associated with misfolded protein intermediates displaying tertiary structure conformational changes eventually leading to forming large polymers of unwanted aggregates. The two hallmarks of AD pathological protein aggregates are extraneuronal β-amyloid (Aβ) based senile plaques and intraneuronal neurofibrillary tangles (NFTs). As such, AD is categorized as a protein misfolding neurodegenerative disease (PMND) . Therapeutic interventions interfering with the formation of these protein aggregates have been widely explored as potential pathways for thwarting AD progression. One such tactic is modulating the function of enzymes involved in the metabolic pathways leading to formation of these misfolded protein aggregates. Much evidence has shown that glycogen synthase kinase-3β (GSK-3β) plays a key role in hyperphosphorylation of tau protein leading eventually to its aggregation to form NFTs. Data presented hereby will display a plethora of information as to how to interfere with progression of AD through the route of GSK-3β activity control.

A fully integrated new paradigm for lithium's mode of action - lithium utilizes latent cellular fail-safe mechanisms

It is proposed that lithium's therapeutic effects occur indirectly by augmenting a cascade of protective "fail-safe" pathways pre-configured to activate in response to a dangerous low cell [Mg⁺⁺] situation, eg, posttraumatic brain injury, alongside relative cell adenosine triphosphate depletion. Lithium activates cell protection, as it neatly mimics a lowered intracellular [Mg⁺⁺] level.

Update on bipolar disorder biomarker candidates

INTRODUCTION

Bipolar disorder is a chronic and disabling mood disorder with a complex pathophysiological basis. A significant percentage of patients do not receive correct diagnosis which directly influences therapeutic response, rendering recovery troublesome. There is a long-standing need for proper non-clinically based tools for diagnosis, treatment selection and follow-up of such patients. Areas covered: In the past decade, the scientific community has shown a great interest in biomarker development. Here, we highlight the different potential biomarkers and we discuss their feasibility and their possible clinical relevance. Expert commentary: To date, despite the major ongoing trials and consortia with promising future perspectives, no reliable biomarker of bipolar disorder has been fully defined.

Antagonist activity of the antipsychotic drug lithium chloride and the antileukemic drug imatinib mesylate during glioblastoma treatment in vitro

OBJECTIVES

Glioblastoma (GBM), the most common primary tumour of the central nervous system, is characterised by a high malignancy and poor prognosis. The aims of this study were to investigate whether the combination of imatinib mesylate (IM) and lithium chloride (LiCl) exhibited a synergistic effect in treatment and to determine whether midkine (MK) affected the fate of this treatment in vitro.

METHODS

Monolayer and spheroid cultures of the T98G human GBM cell line were treated with an IM and LiCl combination for 72 h. The cell proliferation index, apoptotic index, cell cycle distribution, apoptotic and anti-apoptotic protein levels, and cAMP level as well as the cellular morphology and ultrastructure were evaluated.

RESULTS

All applications inhibited cell proliferation and induced apoptosis. The most substantial decreases in cell proliferation and the caspase-3, epidermal growth factor receptor (EGFR), platelet derived growth factor receptor-alpha (PDGFR-α), multidrug resistance protein-1 (MRP-1), aquaporin-4 (AQP-4) and cAMP levels were induced by the LiCl treatment, which exhibited more pronounced effects compared with the combination treatment. LiCl was less effective in decreasing the MK and B cell lymphoma-2 (Bcl-2) levels compared with the combination treatment. The most substantial decrease in the p170 levels was identified following the combination treatment, whereas IM induced the second greatest decrease. LiCl alone had no effect on the p170 levels. IM induced the most substantial decrease in the phospho-glycogen synthase kinase 3-beta (p-GSK-3β)/glycogen synthase kinase 3-beta (GSK-3β) ratio, and LiCl induced the second most substantial decrease. Both LiCl and the combination treatment induced G2 + M arrest, whereas IM induced G0 + G1 arrest after 72 h of exposure. An apoptotic appearance and autophagic vacuoles were commonly identified in the LiCl, combination and IM groups, respectively.

CONCLUSIONS

The combination of IM and LiCl exhibited an antagonist effect, and MK had a role at this antagonism.

Human Pluripotent Stem Cell-derived Cortical Neurons for High Throughput Medication Screening in Autism: A Proof of Concept Study in SHANK3 Haploinsufficiency Syndrome

Autism spectrum disorders affect millions of individuals worldwide, but their heterogeneity complicates therapeutic intervention that is essentially symptomatic. A versatile yet relevant model to rationally screen among hundreds of therapeutic options would help improving clinical practice. Here we investigated whether neurons differentiated from pluripotent stem cells can provide such a tool using SHANK3 haploinsufficiency as a proof of principle. A library of compounds was screened for potential to increase SHANK3 mRNA content in neurons differentiated from control human embryonic stem cells. Using induced pluripotent stem cell technology, active compounds were then evaluated for efficacy in correcting dysfunctional networks of neurons differentiated from individuals with deleterious point mutations of SHANK3. Among 202 compounds tested, lithium and valproic acid showed the best efficacy at corrected SHANK3 haploinsufficiency associated phenotypes in cellulo. Lithium pharmacotherapy was subsequently provided to one patient and, after one year, an encouraging decrease in autism severity was observed. This demonstrated that pluripotent stem cell-derived neurons provide a novel cellular paradigm exploitable in the search for specific disease-modifying treatments.

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Human neurons were used to screen for compounds correcting symptoms associated with SHANK3 haploinsufficiency syndrome.

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Screening criteria were the ability to increase SHANK3 expression and to increase glutamatergic transmission.

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Selected hit compounds were then validated using neurons differentiated from individuals with SHANK3 disrupting mutations.

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Lithium was selected and delivered to one of SHANK3 patient showing encouraging positive clinical outcomes after one year.

The clinical heterogeneity between individuals affected by autism makes it difficult to anticipate the effectiveness of a treatment. Furthermore, clinical practice lacks biological tools to help make such decisions. Here we use neurons, produced from pluripotent stem cells derived from patients affected by SHANK3 haploinsufficiency syndrome, to test the efficiency of therapeutic compounds. We screened the biological activity of more than 200 compounds on SHANK3 expression. Lithium was ultimately selected and delivered to one patient with a SHANK3-disruptive mutation. This resulted in a positive outcome, as determined by improved autistic core symptoms, thus supporting the usefulness of this type of predictive approach.

Mood disorders in the elderly: prevalence, functional impact, and management challenges

Despite the lower prevalence of severe mood disorders in the elderly as compared to younger adults, late-life depression and bipolar disorder (BD) are more strongly associated with negative outcomes related to the presence of medical comorbidities, cognitive deficits, and increased suicide risk and overall mortality. The mechanisms that contribute to these associations are probably multifactorial, involving pathological factors related directly and indirectly to the disease itself, ranging from biological to psychosocial factors. Most of the accumulated knowledge on the nature of these associations derives from naturalistic and observational studies, and controlled data are still scarce. Nonetheless, there has clearly been a recent growth of the scientific interest on late-life BD and geriatric depression. In the present study, we review the most relevant studies on prevalence, clinical presentation, and cognitive/functional impact of mood disorders in elderly. Several clinical-epidemiological studies were dedicated to the study of the prevalence of mood disorders in old age in distinct settings; however, fewer studies investigated the underlying neurobiological findings and treatment specificities in late-life depression and BD. In the present study, we further discuss the implications of these findings on the management of mood disorders in older adults.

Compartment-dependent mitochondrial alterations in experimental ALS, the effects of mitophagy and mitochondriogenesis

Amyotrophic lateral sclerosis (ALS) is characterized by massive loss of motor neurons. Data from ALS patients and experimental models indicate that mitochondria are severely damaged within dying or spared motor neurons. Nonetheless, recent data indicate that mitochondrial preservation, although preventing motor neuron loss, fails to prolong lifespan. On the other hand, the damage to motor axons plays a pivotal role in determining both lethality and disease course. Thus, in the present article each motor neuron compartment (cell body, central, and peripheral axons) of G93A SOD-1 mice was studied concerning mitochondrial alterations as well as other intracellular structures. We could confirm the occurrence of ALS-related mitochondrial damage encompassing total swelling, matrix dilution and cristae derangement along with non-pathological variations of mitochondrial size and number. However, these alterations occur to a different extent depending on motor neuron compartment. Lithium, a well-known autophagy inducer, prevents most pathological changes. However, the efficacy of lithium varies depending on which motor neuron compartment is considered. Remarkably, some effects of lithium are also evident in wild type mice. Lithium is effective also in vitro, both in cell lines and primary cell cultures from the ventral spinal cord. In these latter cells autophagy inhibition within motor neurons in vitro reproduced ALS pathology which was reversed by lithium. Muscle and glial cells were analyzed as well. Cell pathology was mostly severe within peripheral axons and muscles of ALS mice. Remarkably, when analyzing motor axons of ALS mice a subtotal clogging of axoplasm was described for the first time, which was modified under the effects of lithium. The effects induced by lithium depend on several mechanisms such as direct mitochondrial protection, induction of mitophagy and mitochondriogenesis. In this study, mitochondriogenesis induced by lithium was confirmed in situ by a novel approach using [2-³H]-adenosine.

Breast milk protects against the development of necrotizing enterocolitis through inhibition of Toll-like receptor 4 in the intestinal epithelium via activation of the epidermal growth factor receptor

Breast milk is the most effective strategy to protect infants against necrotizing enterocolitis (NEC), a devastating disease that is characterized by severe intestinal necrosis. Previous studies have demonstrated that the lipopolysaccharide receptor Toll-like receptor 4 (TLR4) plays a critical role in NEC development via deleterious effects on mucosal injury and repair. We now hypothesize that breast milk protects against NEC by inhibiting TLR4 within the intestinal epithelium, and sought to determine the mechanisms involved. Breast milk protected against NEC and reduced TLR4 signaling in wild-type neonatal mice, but not in mice lacking the epidermal growth factor receptor (EGFR), whereas selective removal of EGF from breast milk reduced its protective properties, indicating that breast milk inhibits NEC and attenuates TLR4 signaling via EGF/EGFR activation. Overexpression of TLR4 in the intestinal epithelium reversed the protective effects of breast milk. The protective effects of breast milk occurred via inhibition of enterocyte apoptosis and restoration of enterocyte proliferation. Importantly, in IEC-6 enterocytes, breast milk inhibited TLR4 signaling via inhibition of glycogen synthase kinase-3β (GSK3β). Taken together, these findings offer mechanistic insights into the protective role for breast milk in NEC, and support a link between growth factor and innate immune receptors in NEC pathogenesis.

Induction of autophagy is a key component of all-trans-retinoic acid-induced differentiation in leukemia cells and a potential target for pharmacologic modulation

Acute myeloid leukemia (AML) is characterized by the accumulation of immature blood cell precursors in the bone marrow. Pharmacologically overcoming the differentiation block in this condition is an attractive therapeutic avenue, which has achieved success only in a subtype of AML, acute promyelocytic leukemia (APL). Attempts to emulate this success in other AML subtypes have thus far been unsuccessful. Autophagy is a conserved protein degradation pathway with important roles in mammalian cell differentiation, particularly within the hematopoietic system. In the study described here, we investigated the functional importance of autophagy in APL cell differentiation. We found that autophagy is increased during all-trans-retinoic acid (ATRA)-induced granulocytic differentiation of the APL cell line NB4 and that this is associated with increased expression of LC3II and GATE-16 proteins involved in autophagosome formation. Autophagy inhibition, using either drugs (chloroquine/3-methyladenine) or short-hairpin RNA targeting the essential autophagy gene ATG7, attenuates myeloid differentiation. Importantly, we found that enhancing autophagy promotes ATRA-induced granulocytic differentiation of an ATRA-resistant derivative of the non-APL AML HL60 cell line (HL60-Diff-R). These data support the development of strategies to stimulate autophagy as a novel approach to promote differentiation in AML.

Lithium chloride antileukemic activity in acute promyelocytic leukemia is GSK-3 and MEK/ERK dependent

We recently identified that the MEK/ERK1/2 pathway synergized with retinoic acid (RA) to restore both transcriptional activity and RA-induced differentiation in RA-resistant acute promyelocytic leukemia (APL) cells. To target the MEK/ERK pathway, we identified glycogen synthase kinase-3β (GSK-3β) inhibitors including lithium chloride (LiCl) as activators of this pathway in APL cells. Using NB4 (RA-sensitive) and UF-1 (RA-resistant) APL cell lines, we observed that LiCl as well as synthetic GSK-3β inhibitors decreased proliferation, induced apoptosis and restored, in RA-resistant cells, the expression of RA target genes and the RA-induced differentiation. Inhibition of the MEK/ERK1/2 pathway abolished these effects. These results were corroborated in primary APL patient cells and translated in vivo using an APL preclinical mouse model in which LiCl given alone was as efficient as RA in increasing survival of leukemic mice compared with untreated mice. When LiCl was combined with RA, we observed a significant survival advantage compared with mice treated by RA alone. In this work, we demonstrate that LiCl, a well-tolerated agent in humans, has antileukemic activity in APL and that it has the potential to restore RA-induced transcriptional activation and differentiation in RA-resistant APL cells in an MEK/ERK-dependent manner.

Lithium protects against paraquat neurotoxicity by NRF2 activation and miR-34a inhibition in SH-SY5Y cells

Lithium is a mood stabilizing agent commonly used for the treatment of bipolar disorder. Here, we investigated the potential neuroprotective effect of lithium against paraquat toxicity and its underlying mechanisms in vitro. SH-SY5Y human neuroblastoma cells were treated with paraquat (PQ) 0.5 mM concentration after lithium pretreatment to test lithium's capability in preventing cell toxicity. Cell death was evaluated by LDH, WST-8, and tryphan blue assays. Apoptosis was analyzed using DNA fragmentation, Annexin V immunostaining, Sub G1 cell cycle analysis, and caspase-3 activity assays. BCL2, BAX, and NRF2 protein expression were evaluated by Western-blotting and the BDNF protein level was determined with ELISA. mRNA levels of BCL2, BAX, BDNF, and NRF2 target genes (HO-1, GCS, NQO1), as well as miR-34a expression were analyzed by qPCR assay. Functional experiments were done via transfection with NRF2 siRNA and miR-34a mimic. Lithium treatment prevented paraquat induced cell death and apoptosis. Lithium treated cells showed increased anti-apoptotic protein BCL2 and decreased pro-apoptotic protein BAX expression. Lithium exerted a neurotrophic effect by increasing BDNF protein expression. It also diminished reactive oxygen species production and activated the redox sensitive transcription factor NRF2 and increased its target genes expression. Knockdown of NRF2 abolished neuroprotective, anti-apoptotic, and anti-oxidant effects of lithium. Furthermore, lithium significantly decreased both basal and PQ-induced expression of miR-34a. Transfection of miR-34a specific mimic reversed neuroprotective, anti-apoptotic, and anti-oxidant effects of lithium against PQ-toxicity. Our results revealed two novel mechanisms of lithium neuroprotection, namely NRF2 activation and miR-34a suppression.

Telomerase dysregulation in the hippocampus of a rat model of depression: normalization by lithium

BACKGROUND

Telomeres are protective DNA-protein complexes at the ends of each chromosome, maintained primarily by the enzyme telomerase. Shortening of the blood leukocyte telomeres is associated with aging, several chronic diseases, and stress, eg, major depression. Hippocampus is pivotal in the regulation of cognition and mood and the main brain region of telomerase activity. Whether there is telomere dysfunction in the hippocampus of depressed subjects is unknown. Lithium, used in the treatment and relapse prevention of mood disorders, was found to protect against leukocyte telomere shortening in humans, but the mechanism has not been elucidated. To answer the questions whether telomeres are shortened and the telomerase activity changed in the hippocampus and whether lithium could reverse the process, we used a genetic model of depression, the Flinders Sensitive Line rat, and treated the animals with lithium.

METHODS

Telomere length, telomerase reverse transcriptase (Tert) expression, telomerase activity, and putative mediators of telomerase activity were investigated in the hippocampus of these animals.

RESULTS

The naïve Flinders Sensitive Line had shorter telomere length, downregulated Tert expression, reduced brain-derived neurotrophic factor levels, and reduced telomerase activity compared with the Flinders Resistant Line controls. Lithium treatment normalized the Tert expression and telomerase activity in the Flinders Sensitive Line and upregulated β-catenin.

CONCLUSION

This is the first report showing telomere dysregulation in hippocampus of a well-defined depression model and restorative effects of lithium treatment. If replicated in other models of mood disorder, the findings will contribute to understanding both the telomere function and the mechanism of lithium action in hippocampus of depressed patients.

Pharmacological approaches to improving cognitive function in Down syndrome: current status and considerations

Down syndrome (DS), also known as trisomy 21, is the most common genetic cause of intellectual disability (ID). Although ID can be mild, the average intelligence quotient is in the range of 40-50. All individuals with DS will also develop the neuropathology of Alzheimer's disease (AD) by the age of 30-40 years, and approximately half will display an AD-like dementia by the age of 60 years. DS is caused by an extra copy of the long arm of human chromosome 21 (Hsa21) and the consequent elevated levels of expression, due to dosage, of trisomic genes. Despite a worldwide incidence of one in 700-1,000 live births, there are currently no pharmacological treatments available for ID or AD in DS. However, over the last several years, very promising results have been obtained with a mouse model of DS, the Ts65Dn. A diverse array of drugs has been shown to rescue, or partially rescue, DS-relevant deficits in learning and memory and abnormalities in cellular and electrophysiological features seen in the Ts65Dn. These results suggest that some level of amelioration or prevention of cognitive deficits in people with DS may be possible. Here, we review information from the preclinical evaluations in the Ts65Dn, how drugs were selected, how efficacy was judged, and how outcomes differ, or not, among studies. We also summarize the current state of human clinical trials for ID and AD in DS. Lastly, we describe the genetic limitations of the Ts65Dn as a model of DS, and in the preclinical testing of pharmacotherapeutics, and suggest additional targets to be considered for potential pharmacotherapies.

Sorafenib and lithium chloride combination treatment shows promising synergistic effects in human glioblastoma multiforme cells in vitro but midkine is not implicated

OBJECTIVES

The objectives of this study were to test the effects of the new combination treatment modality, sorafenib (SOR) and lithium chloride (LiCl) and to assess whether midkine (MK) protein has a role in any potential effects.

METHODS

Monolayer and spheroid cultures of T98G human glioblastoma multiforme (GBM) cells were treated with LiCl and SOR (inhibition concentration 50 value  =  100 μM), or their combination, or were left untreated (control). Cell proliferation and apoptotic indices, the mechanism of action, and the levels of apoptotic and anti-apoptotic proteins were evaluated in monolayer cultures and ultrastructure was evaluated by transmission electron microscopy (TEM) in spheroid cultures after for 72 hours.

RESULTS

All drug applications decreased cell numbers and increased the apoptotic index. The combination shows a synergistic effect. In the combination group, the decrease in cell numbers and the increase in the apoptotic index were significantly greater than with the individual drugs (P < 0.01). The combination treatment led to the greatest decreases in MRP-1 and p170 levels; but the greatest decreases in p-STAT-3, p-ERK (P < 0.05), p-AKT, p-GSK-3-beta (P < 0.01), EGFR (P < 0.01), NF-kappa-β levels were with SOR alone, followed by the combination. The decreases in MK levels in the SOR and combination groups were similar (P  =  0.06). Severe ultrastructural damage was more frequently observed in the combination group compared with the other groups.

CONCLUSIONS

These results suggest the possibility that the addition of LiCl to SOR could improve the prognosis in at least some patients who need both cancer and psychotherapy and indicate the need for further studies.

Neuroprotective effects of lithium: implications for the treatment of Alzheimer's disease and related neurodegenerative disorders

Lithium is a well-established therapeutic option for the acute and long-term management of bipolar disorder and major depression. More recently, based on findings from translational research, lithium has also been regarded as a neuroprotective agent and a candidate drug for disease-modification in certain neurodegenerative disorders, namely, Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), and, more recently, Parkinson's disease (PD). The putative neuroprotective effects of lithium rely on the fact that it modulates several homeostatic mechanisms involved in neurotrophic response, autophagy, oxidative stress, inflammation, and mitochondrial function. Such a wide range of intracellular responses may be secondary to two key effects, that is, the inhibition of glycogen synthase kinase-3 beta (GSK-3β) and inositol monophosphatase (IMP) by lithium. In the present review, we revisit the neurobiological properties of lithium in light of the available evidence of its neurotrophic and neuroprotective properties, and discuss the rationale for its use in the treatment and prevention of neurodegenerative diseases.

Plastic changes in the spinal cord in motor neuron disease

In the present paper, we analyze the cell number within lamina X at the end stage of disease in a G93A mouse model of ALS; the effects induced by lithium; the stem-cell like phenotype of lamina X cells during ALS; the differentiation of these cells towards either a glial or neuronal phenotype. In summary we found that G93A mouse model of ALS produces an increase in lamina X cells which is further augmented by lithium administration. In the absence of lithium these nestin positive stem-like cells preferentially differentiate into glia (GFAP positive), while in the presence of lithium these cells differentiate towards a neuron-like phenotype (βIII-tubulin, NeuN, and calbindin-D28K positive). These effects of lithium are observed concomitantly with attenuation in disease progression and are reminiscent of neurogenetic effects induced by lithium in the subependymal ventricular zone of the hippocampus.