Novel insights into lithium's mechanism of action: neurotrophic and neuroprotective effects

Emerging Perspectives on Neuroprotection

Neuroprotection aims to safeguard neurons from damage caused by various factors like stress, potentially leading to the rescue, recovery, or regeneration of the nervous system and its functions [J Clin Neurosci. 2002;9(1):4-8]. Conversely, neuroplasticity refers to the brain's ability to adapt and change throughout life, involving structural and functional alterations in cells and synaptic transmission [Neural Plast. 2014;2014:541870]. Neuroprotection is a broad and multidisciplinary field encompassing various approaches and strategies aimed at preserving and promoting neuronal health. It is a critical area of research in neuroscience and neurology, with the potential to lead to new therapies for a wide range of neurological disorders and conditions. Neuroprotection can take various forms and may involve pharmacological agents, lifestyle modifications, or behavioral interventions. Accordingly, also the perspective and the meaning of neuroprotection differs due to different angles of interpretation. The primary interpretation is from the pharmacological point of view since the most consistent data come from this field. In addition, we will discuss also alternative, yet less considered, perspectives on neuroprotection, focusing on specific neuroprotective targets, interactions with surrounding microglia, different levels of neuroprotective effects, the reversive/adaptative dimension, and its use as anticipatory/prophylactic intervention.

Intracellular effects of lithium in aging neurons

Lithium therapy received approval during the 1970s, and it has been used for its antidepressant, antimanic, and anti-suicidal effects for acute and long-term prophylaxis and treatment of bipolar disorder (BPD). These properties have been well established; however, the molecular and cellular mechanisms remain controversial. In the past few years, many studies demonstrated that at the cellular level, lithium acts as a regulator of neurogenesis, aging, and Ca2+ homeostasis. At the molecular level, lithium modulates aging by inhibiting glycogen synthase kinase-3β (GSK-3β), and the phosphatidylinositol (PI) cycle; latter, lithium specifically inhibits inositol production, acting as a non-competitive inhibitor of inositol monophosphatase (IMPase). Mitochondria and peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) have been related to lithium activity, and its regulation is mediated by GSK-3β degradation and inhibition. Lithium also impacts Ca2+ homeostasis in the mitochondria modulating the function of the lithium-permeable mitochondrial Na+-Ca2+exchanger (NCLX), affecting Ca2+ efflux from the mitochondrial matrix to the endoplasmic reticulum (ER). A close relationship between the protease Omi, GSK-3β, and PGC-1α has also been established. The purpose of this review is to summarize some of the intracellular mechanisms related to lithium activity and how, through them, neuronal aging could be controlled.

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.

An insight into crosstalk among multiple signalling pathways contributing to the pathophysiology of PTSD and depressive disorders

Post-traumatic stress disorder (PTSD) and depressive disorders represent two significant mental health challenges with substantial global prevalence. These are debilitating conditions characterized by persistent, often comorbid, symptoms that severely impact an individual's quality of life. Both PTSD and depressive disorders are often precipitated by exposure to traumatic events or chronic stress. The profound impact of PTSD and depressive disorders on individuals and society necessitates a comprehensive exploration of their shared and distinct pathophysiological features. Although the activation of the stress system is essential for maintaining homeostasis, the ability to recover from it after diminishing the threat stimulus is also equally important. However, little is known about the main reasons for individuals' differential susceptibility to external stressful stimuli. The solution to this question can be found by delving into the interplay of stress with the cognitive and emotional processing of traumatic incidents at the molecular level. Evidence suggests that dysregulation in these signalling cascades may contribute to the persistence and severity of PTSD and depressive symptoms. The treatment strategies available for this disorder are antidepressants, which have shown good efficiency in normalizing symptom severity; however, their efficacy is limited in most individuals. This calls for the exploration and development of innovative medications to address the treatment of PTSD. This review delves into the intricate crosstalk among multiple signalling pathways implicated in the development and manifestation of these mental health conditions. By unravelling the complexities of crosstalk among multiple signalling pathways, this review aims to contribute to the broader knowledge base, providing insights that could inform the development of targeted interventions for individuals grappling with the challenges of PTSD and depressive disorders.

SPIRAL MRI for in vivo lithium-7 imaging: a feasibility study in mice after oral lithium treatment

Lithium has been the frontline treatment for bipolar disorder for over 60 years. However, its mode of action and distribution in the brain is still incompletely understood. The primary isotope of lithium, lithium-7 (7Li), is a magnetic resonance (MR) active, spin-3/2 nucleus. However, its low MR sensitivity and the small brain size of mice make 7Li MR imaging (MRI) difficult in preclinical research. We tested four MRI sequences (FLASH, RARE, bSSFP, and SPIRAL) on lithium-containing phantoms, and bSSFP and SPIRAL on orally lithium-treated adult C57BL/6 mice. 7Li MR spectroscopy was acquired weekly at 9.4T to monitor the lithium uptake. The in vivo T1 relaxation time of 7Li was estimated in four mice. 4-h SPIRAL 7Li MRI was acquired in ten mice at a resolution of 2 × 2 × 3 mm3. SPIRAL MRI provided the highest signal-to-noise ratio (SNR) per unit acquisition time and the best image quality. We observed a non-homogeneous distribution of lithium in the mouse brain, with the highest concentrations in the cortex, ventricles, and basal brain regions. Almost no lithium signal was detected in the olfactory bulb and the cerebellum. We showed that in vivo 7Li MRI in mice is feasible, although with limited spatial resolution and SNR.

Drugs with a negative impact on cognitive functions (Part 2): drug classes to consider while prescribing in CKD patients

There is growing evidence that chronic kidney disease (CKD) is an independent risk factor for cognitive impairment, especially due to vascular damage, blood-brain barrier disruption and uremic toxins. Given the presence of multiple comorbidities, the medication regimen of CKD patients often becomes very complex. Several medications such as psychotropic agents, drugs with anticholinergic properties, GABAergic drugs, opioids, corticosteroids, antibiotics and others have been linked to negative effects on cognition. These drugs are frequently included in the treatment regimen of CKD patients. The first review of this series described how CKD could represent a risk factor for adverse drug reactions affecting the central nervous system. This second review will describe some of the most common medications associated with cognitive impairment (in the general population and in CKD) and describe their effects.

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.

Blood and cerebrospinal fluid biomarker changes in patients with HIV-associated neurocognitive impairment treated with lithium: analysis from a randomised placebo-controlled trial

HIV-associated neurocognitive disorders (HAND) persist in the era of antiretroviral therapy (ART). Thus, ART does not completely halt or reverse the pathological processes behind HAND. Adjuvant mitigating treatments are, therefore, prudent. Lithium treatment is known to promote neuronal brain-derived neurotrophic factors (BDNF). Lithium is also an inhibitor of glycogen synthase kinase-3 beta (GSK-3-β). We analyzed biomarkers obtained from participants in a randomized placebo-controlled trial of lithium in ART-treated individuals with moderate or severe HAND. We assayed markers at baseline and 24 weeks across several pathways hypothesized to be affected by HIV, inflammation, or degeneration. Investigated biomarkers included dopamine, BDNF, neurofilament light chain, and CD8 + lymphocyte activation (CD38 + HLADR +). Alzheimer's Disease (AD) biomarkers included soluble amyloid precursor protein alpha and beta (sAPPα/β), Aβ38, 40, 42, and ten other biomarkers validated as predictors of mild cognitive impairment and progression in previous studies. These include apolipoprotein C3, pre-albumin, α1-acid glycoprotein, α1-antitrypsin, PEDF, CC4, ICAM-1, RANTES, clusterin, and cystatin c. We recruited 61 participants (placebo = 31; lithium = 30). The age baseline mean was 40 (± 8.35) years and the median CD4 + T-cell count was 498 (IQR: 389-651) cells/μL. Biomarker concentrations between groups did not differ at baseline. However, both groups' blood dopamine levels decreased significantly after 24 weeks (adj. p < 002). No other marker was significantly different between groups, and we concluded that lithium did not confer neuroprotection following 24 weeks of treatment. However, the study was limited in duration and sample size.

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.

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.

Why lithium should be used in patients with bipolar disorder? A scoping review and an expert opinion paper

INTRODUCTION

Lithium treatment is considered the gold standard for the long-term management of bipolar disorder and recurrent unipolar depression. It is also extremely effective in other psychiatric conditions characterized by impulsivity and aggression, and for the prevention of suicidal behaviours.

AREAS COVERED

This paper provides a scoping review and an expert commentary regarding the use of lithium in adult patients. Available information about efficacy, tolerability, dosing, and switching is analyzed, and the strategies that may be most useful in real-world clinical settings are highlighted.

EXPERT OPINION

Lithium is effective on different domains of bipolar disorder, including the long-term prevention of recurrences of affective episodes, management of acute mania as well as in the prophylaxis of all affective episodes. Lithium has been defined a 'forgotten drug,' since its use in routine clinical practice has been declined over the last 20 or 30 years. Reasons for this trend include lack of adequate training on the management of lithium side effects. Considering its efficacy, use of lithium in ordinary clinical practice should be promoted. Several strategies, such as using slow-release formulations, can be easily implemented in order to minimize lithium side effects and improve its tolerability profile.

Neuromolecular Etiology of Bipolar Disorder: Possible Therapeutic Targets of Mood Stabilizers

Bipolar disorder is a mental illness that causes extreme mood swings and has a chronic course. However, the mechanism by which mood episodes with completely opposite characteristics appear repeatedly, or a mixture of symptoms appears, in patients with bipolar disorder remains unknown. Therefore, mood stabilizers are indicated only for single mood episodes, such as manic episodes and depressive episodes, and no true mood-stabilizing drugs effective for treating both manic and depressive episodes currently exist. Therefore, in this review, therapeutic targets that facilitate the development of mood stabilizers were examined by reviewing the current understanding of the neuromolecular etiology of bipolar disorder.

Efficacy and Safety of Lithium Treatment in SARS-CoV-2 Infected Patients

At the beginning of the pandemic, we observed that lithium carbonate had a positive effect on the recovery of severely ill patients with COVID-19. Lithium is able to inhibit the replication of several types of viruses, some of which are similar to the SARS-CoV-2 virus, increase the immune response and reduce inflammation by preventing or reducing the cytokine storm. Previously, we published an article with data from six patients with severe COVID-19 infection, where we proposed that lithium carbonate could be used as a potential treatment for COVID-19. Now, we set out to conduct a randomized clinical trial number EudraCT 2020–002008–37 to evaluate the efficacy and safety of lithium treatment in patients infected with severe SARS-CoV-2. We showed that lithium was able to reduce the number of days of hospital and intensive care unit admission as well as the risk of death, reduces inflammatory cytokine levels by preventing cytokine storms, and also reduced the long COVID syndromes. We propose that lithium carbonate can be used to reduce the severity of COVID-19.

Malondialdehyde as a candidate biomarker for bipolar disorder: A meta-analysis

Malondialdehyde (MDA) represents one of the final products of lipid peroxidation that is thought to be enhanced and accelerated in patients affected by bipolar disorder (BD). Purpose of the present article is to critically summarize the available data about MDA as a candidate biomarker for BD. First, we carried out a systematic review of the literature selecting those papers that evaluated MDA levels in BD. Then, we performed two separate meta-analyses: one of the studies that compared healthy controls (HC) with unmedicated BD and one with the studies that assessed MDA levels before and after treatment in BD, showing that bipolar patients experience more oxidative stress than healthy subjects and that treatment is effective in reducing MDA levels. In the first set of studies, we also explored through a meta-regression whether age, gender and experiencing an episode specifically influenced the difference between BD and HC in MDA levels. Bipolar patients compared to healthy subjects had higher MDA levels (SMD: 0.94, 95% CI: 0.23-1.64). Age (p < 0.01), gender (p < 0.01) and the presence of a current mood episode (p < 0.01) significantly influenced MDA plasma/serum levels. Specifically, studies that included more female, older subjects and more BD in euthymia were more likely to have higher MDA levels. Finally, patients after treatment had lower levels of MDA compared to baseline (SMD: -0.52, 95% CI: -0.85 -0.19). More studies are needed to draw definitive conclusions.

Lithium augmentation of ketamine increases insulin signaling and antidepressant-like active stress coping in a rodent model of treatment-resistant depression

Lithium, a mood stabilizer and common adjunctive treatment for refractory depression, shares overlapping mechanisms of action with ketamine and enhances the duration of ketamine's antidepressant actions in rodent models at sub-therapeutic doses. Yet, in a recent clinical trial, lithium co-treatment with ketamine failed to improve antidepressant outcomes in subjects previously shown to respond to ketamine alone. The potential for lithium augmentation to improve antidepressant outcomes in ketamine nonresponders, however, has not been explored. The current study examined the behavioral, molecular and metabolic actions of lithium and ketamine co-treatment in a rodent model of antidepressant resistance. Male Wistar rats were administered adrenocorticotropic hormone (ACTH; 100 µg/day, i.p. over 14 days) and subsequently treated with ketamine (10 mg/kg; 2 days; n = 12), lithium (37 mg/kg; 2 days; n = 12), ketamine + lithium (10 mg/kg + 37 mg/kg; 2 days; n = 12), or vehicle saline (0.9%; n = 12). Rats were subjected to open field (6 min) and forced swim tests (6 min). Peripheral blood and brain prefrontal cortical (PFC) tissue was collected one hour following stress exposure. Western blotting was used to determine the effects of treatment on extracellular signal-regulated kinase (ERK); mammalian target of rapamycin (mTOR), phospho kinase B (Akt), and glycogen synthase kinase-3ß (GSK3ß) protein levels in the infralimbic (IL) and prelimbic (PL) subregions of the PFC. Prefrontal oxygen consumption rate (OCR) and extracellular acidification rates (ECAR) were also determined in anterior PFC tissue at rest and following stimulation with brain-derived neurotrophic factor (BDNF) and tumor necrosis factor α (TNFα). Blood plasma levels of mTOR and insulin were determined using enzyme-linked immunosorbent assays (ELISAs). Overall, rats receiving ketamine+lithium displayed a robust antidepressant response to the combined treatment as demonstrated through significant reductions in immobility time (p < 0.05) and latency to immobility (p < 0.01). These animals also had higher expression of plasma mTOR (p < 0.01) and insulin (p < 0.001). Tissue bioenergetics analyses revealed that combined ketamine+lithium treatment did not significantly alter the respiratory response to BDNF or TNFα. Animals receiving both ketamine and lithium had significantly higher phosphorylation (p)-to-total expression ratios of mTOR (p < 0.001) and Akt (p < 0.01), and lower ERK in the IL compared to control animals. In contrast, pmTOR/mTOR levels were reduced in the PL of ketamine+lithium treated animals, while pERK/ERK expression levels were elevated. Taken together, these data demonstrate that lithium augmentation of ketamine in antidepressant nonresponsive animals improves antidepressant-like behavioral responses under stress, together with peripheral insulin efflux and region-specific PFC insulin signaling.

Calcium in Signaling: Its Specificity and Vulnerabilities toward Biogenic and Abiogenic Metal Ions

Divalent calcium ion (Ca²⁺) plays an indispensable role as a second messenger in a myriad of signal transduction processes. Of utmost importance for the faultless functioning of calcium-modulated signaling proteins is their binding selectivity of the native metal cation over rival biogenic/abiogenic metal ion contenders in the intra/extracellular fluids. In this Perspective, we summarize recent findings on the competition between the cognate Ca²⁺ and other biogenic or abiogenic divalent cations for binding to Ca²⁺-signaling proteins or organic cofactors. We describe the competition between the two most abundant intracellular biogenic metal ions (Mg²⁺ and Ca²⁺) for Ca²⁺-binding sites in signaling proteins, followed by the rivalry between native Ca²⁺ and "therapeutic" Li⁺ as well as "toxic" Pb²⁺. We delineate the key factors governing the rivalry between the native and non-native cations in proteins and highlight key implications for the biological performance of the respective proteins/organic cofactors.

Posttranslational modifications & lithium's therapeutic effect-Potential biomarkers for clinical responses in psychiatric & neurodegenerative disorders

Several neurodegenerative diseases and neuropsychiatric disorders display aberrant posttranslational modifications (PTMs) of one, or many, proteins. Lithium treatment has been used for mood stabilization for many decades, and is highly effective for large subsets of patients with diverse neurological conditions. However, the differential effectiveness and mode of action are not fully understood. In recent years, studies have shown that lithium alters several protein PTMs, altering their function, and consequently neuronal physiology. The impetus for this review is to outline the links between lithium's therapeutic mode of action and PTM homeostasis. We first provide an overview of the principal PTMs affected by lithium. We then describe several neuropsychiatric disorders in which PTMs have been implicated as pathogenic. For each of these conditions, we discuss lithium's clinical use and explore the putative mechanism of how it restores PTM homeostasis, and thereby cellular physiology. Evidence suggests that determining specific PTM patterns could be a promising strategy to develop biomarkers for disease and lithium responsiveness.

The Role of Mitochondria in Mood Disorders: From Physiology to Pathophysiology and to Treatment

Mitochondria are cellular organelles involved in several biological processes, especially in energy production. Several studies have found a relationship between mitochondrial dysfunction and mood disorders, such as major depressive disorder and bipolar disorder. Impairments in energy production are found in these disorders together with higher levels of oxidative stress. Recently, many agents capable of enhancing antioxidant defenses or mitochondrial functioning have been studied for the treatment of mood disorders as adjuvant therapy to current pharmacological treatments. A better knowledge of mitochondrial physiology and pathophysiology might allow the identification of new therapeutic targets and the development and study of novel effective therapies to treat these specific mitochondrial impairments. This could be especially beneficial for treatment-resistant patients. In this article, we provide a focused narrative review of the currently available evidence supporting the involvement of mitochondrial dysfunction in mood disorders, the effects of current therapies on mitochondrial functions, and novel targeted therapies acting on mitochondrial pathways that might be useful for the treatment of mood disorders.

Enhanced Neural Differentiation of Epidermal Neural Crest Stem Cell by Synergistic Effect of Lithium carbonate and Crocin on BDNF and GDNF Expression as Neurotrophic Factors

Neurodegenerative diseases are incurable and debilitating conditions that result in progressive degeneration of nerve cells. Due to the complexity of conditions in neurodegenerative diseases, combination therapy, including cell and drug therapy is important as a new therapeutic strategy. Epidermal neural crest stem cells (EPI-NCSCs) are among the best choices in cell therapy for various neurological diseases. In this study, the effect of Lithium carbonate and Crocin, considering their effects on cellular signaling pathways and neuroprotective properties were investigated on the expression of neurotrophic factors BDNF and GDNF in EPI-NCSCs. EPI-NCSCs were isolated from the hair follicle and treated with different concentrations of drugs [Lithium, Crocin, and lithium + Crocin] for 72h. Then, trial concentrations were selected by MTT assay. The cells were treated with selected concentrations (Lithium 1 mM, Crocin 1.5 mM, and for co-treatment Lithium 1 mM and Crocin 1 mM) for 7 days. The Real-Time PCR results indicated an increasing in expression of BDNF and GDNF in treated cells as compared with control (* p < 0.05, ** p < 0.01 and *** p < 0.001). The results in this study confirmed and supported the neuroprotective/neurogenesis effects of Lithium and Crocin. It also showed that the proposed protocol could be used to increase EPI-NCSCs differentiation potential into neural cells in cell therapy and combination therapy of neurodegenerative diseases.

Improved survival in amyotrophic lateral sclerosis patients following autologous bone marrow mononuclear cell therapy: a long term 10-year retrospective study

Background:

Promising results from previous studies using cell therapy have paved the way for an innovative treatment option for amyotrophic lateral sclerosis (ALS). There is considerable evidence of immune and inflammatory abnormalities in ALS. Bone marrow mononuclear cells (BMMNCs) possess immunomodulatory properties and could contribute to slowing of disease progression.

Objective:

Aim of our study was to evaluate the long-term effect of autologous BMMNCs combined with standard treatment on survival duration in a large population and to evaluate effect of type of onset and hormonal status on survival duration in the intervention group.

Methods:

This controlled, retrospective study spanned over 10 years, 5 months; included 216 patients with probable or definite ALS, 150 in intervention group receiving autologous BMMNCs and standard treatment, and 66 in control group receiving only standard treatment. The estimated survival duration of control group and intervention group was computed and compared using Kaplan Meier analysis. Survival duration of patients with different types of onset and hormonal status was compared within the intervention group.

Results:

None of the patients reported any major adverse events related to cell administration or the procedure. Kaplan Meier analysis estimated survival duration in the intervention group to be 91.7 months while 49.7 months in the control group (p = 0.008). Within the intervention group, estimated survival was significantly higher (p = 0.013) in patients with limb onset (102.3 months) vs. bulbar onset (49.9 months); premenopausal women (93.1 months) vs. postmenopausal women (57.6 months) (p = 0.002); and preandropausal men (153.7 months) vs. postandropausal males (56.5 months) (p = 0.006).

Conclusion:

Cell therapy using autologous BMMNCs along with standard treatment offers a promising and safe option for ALS with the potential of long term beneficial effect and increased survival. Limb onset patients, premenopausal women and men ≤ 40 years of age demonstrated better treatment efficacy.

Mitochondria under the spotlight: On the implications of mitochondrial dysfunction and its connectivity to neuropsychiatric disorders

Neuropsychiatric disorders (NPDs) such as bipolar disorder (BD), schizophrenia (SZ) and mood disorder (MD) are hard to manage due to overlapping symptoms and lack of biomarkers. Risk alleles of BD/SZ/MD are emerging, with evidence suggesting mitochondrial (mt) dysfunction as a critical factor for disease onset and progression. Mood stabilizing treatments for these disorders are scarce, revealing the need for biomarker discovery and artificial intelligence approaches to design synthetically accessible novel therapeutics. Here, we show mt involvement in NPDs by associating 245 mt proteins to BD/SZ/MD, with 7 common players in these disease categories. Analysis of over 650 publications suggests that 245 NPD-linked mt proteins are associated with 800 other mt proteins, with mt impairment likely to rewire these interactions. High dosage of mood stabilizers is known to alleviate manic episodes, but which compounds target mt pathways is another gap in the field that we address through mood stabilizer-gene interaction analysis of 37 prescriptions and over-the-counter psychotropic treatments, which we have refined to 15 mood-stabilizing agents. We show 26 of the 245 NPD-linked mt proteins are uniquely or commonly targeted by one or more of these mood stabilizers. Further, induced pluripotent stem cell-derived patient neurons and three-dimensional human brain organoids as reliable BD/SZ/MD models are outlined, along with multiomics methods and machine learning-based decision making tools for biomarker discovery, which remains a bottleneck for precision psychiatry medicine.

Lithium and the Interplay Between Telomeres and Mitochondria in Bipolar Disorder

Bipolar disorder is a severe psychiatric disorder which affects more than 1% of the world's population and is a leading cause of disability among young people. For the past 50 years, lithium has been the drug of choice for maintenance treatment of bipolar disorder due to its potent ability to prevent both manic and depressive episodes as well as suicide. However, though lithium has been associated with a multitude of effects within different cellular pathways and biological systems, its specific mechanism of action in stabilizing mood remains largely elusive. Mitochondrial dysfunction and telomere shortening have been implicated in both the pathophysiology of bipolar disorder and as targets of lithium treatment. Interestingly, it has in recent years become clear that these phenomena are intimately linked, partly through reactive oxygen species signaling and the subcellular translocation and non-canonical actions of telomerase reverse transcriptase. In this review, we integrate the current understanding of mitochondrial dysfunction, oxidative stress and telomere shortening in bipolar disorder with documented effects of lithium. Moreover, we propose that lithium's mechanism of action is intimately connected with the interdependent regulation of mitochondrial bioenergetics and telomere maintenance.

Depression, GABA, and Age Correlate with Plasma Levels of Inflammatory Markers

Immunomodulation is increasingly being recognised as a part of mental diseases. Here, we examined whether levels of immunological protein markers changed with depression, age, or the inhibitory neurotransmitter gamma-aminobutyric acid (GABA). An analysis of plasma samples from patients with a major depressive episode and control blood donors (CBD) revealed the expression of 67 inflammatory markers. Thirteen of these markers displayed augmented levels in patients compared to CBD. Twenty-one markers correlated with the age of the patients, whereas 10 markers correlated with the age of CBD. Interestingly, CST5 and CDCP1 showed the strongest correlation with age in the patients and CBD, respectively. IL-18 was the only marker that correlated with the MADRS-S scores of the patients. Neuronal growth factors (NGFs) were significantly enhanced in plasma from the patients, as was the average plasma GABA concentration. GABA modulated the release of seven cytokines in anti-CD3-stimulated peripheral blood mononuclear cells (PBMCs) from the patients. The study reveals significant changes in the plasma composition of small molecules during depression and identifies potential peripheral biomarkers of the disease.

Lithium alters expression of RNAs in a type-specific manner in differentiated human neuroblastoma neuronal cultures, including specific genes involved in Alzheimer's disease

Lithium (Li) is a medication long-used to treat bipolar disorder. It is currently under investigation for multiple nervous system disorders, including Alzheimer's disease (AD). While perturbation of RNA levels by Li has been previously reported, its effects on the whole transcriptome has been given little attention. We, therefore, sought to determine comprehensive effects of Li treatment on RNA levels. We cultured and differentiated human neuroblastoma (SK-N-SH) cells to neuronal cells with all-trans retinoic acid (ATRA). We exposed cultures for one week to lithium chloride or distilled water, extracted total RNA, depleted ribosomal RNA and performed whole-transcriptome RT-sequencing. We analyzed results by RNA length and type. We further analyzed expression and protein interaction networks between selected Li-altered protein-coding RNAs and common AD-associated gene products. Lithium changed expression of RNAs in both non-specific (inverse to sequence length) and specific (according to RNA type) fashions. The non-coding small nucleolar RNAs (snoRNAs) were subject to the greatest length-adjusted Li influence. When RNA length effects were taken into account, microRNAs as a group were significantly less likely to have had levels altered by Li treatment. Notably, several Li-influenced protein-coding RNAs were co-expressed or produced proteins that interacted with several common AD-associated genes and proteins. Lithium's modification of RNA levels depends on both RNA length and type. Li activity on snoRNA levels may pertain to bipolar disorders while Li modification of protein coding RNAs may be relevant to AD.

Brain age in bipolar disorders: Effects of lithium treatment

OBJECTIVE

Bipolar disorders increase the risk of dementia and show biological and brain alterations, which resemble accelerated aging. Lithium may counter some of these processes and lower the risk of dementia. However, until now no study has specifically investigated the effects of Li on brain age.

METHODS

We acquired structural magnetic resonance imaging scans from 84 participants with bipolar disorders (41 with and 43 without Li treatment) and 45 controls. We used a machine learning model trained on an independent sample of 504 controls to estimate the individual brain ages of study participants, and calculated BrainAGE by subtracting chronological from the estimated brain age.

RESULTS

BrainAGE was significantly greater in non-Li relative to Li or control participants, F(2, 125) = 10.22, p < 0.001, with no differences between the Li treated and control groups. The estimated brain age was significantly higher than the chronological age in the non-Li (4.28 ± 6.33 years, matched t(42) = 4.43, p < 0.001), but not the Li-treated group (0.48 ± 7.60 years, not significant). Even Li-treated participants with partial prophylactic treatment response showed lower BrainAGE than the non-Li group, F(1, 64) = 4.80, p = 0.03.

CONCLUSIONS

Bipolar disorders were associated with greater, whereas Li treatment with lower discrepancy between brain and chronological age. These findings support the neuroprotective effects of Li, which were sufficiently pronounced to affect a complex, multivariate measure of brain structure. The association between Li treatment and BrainAGE was independent of long-term thymoprophylactic response and thus may generalize beyond bipolar disorders, to neurodegenerative disorders.

Increasing doses of ketamine curtail antidepressant responses and suppress associated synaptic signaling pathways

Clinical findings show that a single subanesthetic dose of ketamine elicits rapid antidepressant effects. Accumulating data suggests that ketamine blocks the N-methyl-D-aspartate receptor and results in specific effects on intracellular signaling including increased brain-derived neurotrophic factor (BDNF) protein expression, which augments synaptic responses required for rapid antidepressant effects. To further investigate this potential mechanism for ketamine's antidepressant action, we examined the effect of increasing ketamine doses on intracellular signaling, synaptic plasticity, and rapid antidepressant effects. Given that ketamine is often used at 2.5-10 mg/kg to examine antidepressant effects and 20-50 mg/kg to model schizophrenia, we compared effects at 5, 20 and 50 mg/kg. We found that intraperitoneal (i.p.) injection of low dose (5 mg/kg) ketamine produces rapid antidepressant effects, which were not observed at 20 or 50 mg/kg. At 5 mg/kg ketamine significantly increased the level of BDNF, a protein necessary for the rapid antidepressant effects, while 20 and 50 mg/kg ketamine did not alter BDNF levels in the hippocampus. Low concentration ketamine also evoked the highest synaptic potentiation in the hippocampal CA1, while higher concentrations significantly decreased the synaptic effects. Our results suggest low dose ketamine produces antidepressant effects and has independent behavioral and synaptic effects compared to higher doses of ketamine that are used to model schizophrenia. These findings strengthen our knowledge on specific signaling associated with ketamine's rapid antidepressant effects.

Free and Bound Therapeutic Lithium in Brain Signaling

Lithium, a first-line therapy for bipolar disorder, is effective in preventing suicide and new depressive/manic episodes. Yet, how this beguilingly simple monocation with only two electrons could yield such profound therapeutic effects remains unclear. An in-depth understanding of lithium's mechanisms of actions would help one to develop better treatments limiting its adverse side effects and repurpose lithium for treating traumatic brain injury and chronic neurodegenerative diseases. In this Account, we begin with a comparison of the physicochemical properties of Li⁺ and its key native rivals, Na⁺ and Mg²⁺, to provide physical grounds for their competition in protein binding sites. Next, we review the abnormal signaling pathways and proteins found in bipolar patients, who generally have abnormally high intracellular Na⁺ and Ca²⁺ concentrations, high G-protein levels, and hyperactive phosphatidylinositol signaling and glycogen synthase kinase-3β (GSK3β) activity. We briefly summarize experimental findings on how lithium, at therapeutic doses, modulates these abnormal signaling pathways and proteins. Following this survey, we address the following aspects of lithium's therapeutic actions: (1) Can Li⁺ displace Na⁺ from the allosteric Na⁺-binding sites in neurotransmitter transporters and G-protein coupled receptors (GPCRs); if so, how would this affect the host protein's function? (2) Why are certain Mg²⁺-dependent enzymes targeted by Li⁺? (3) How does Li⁺ binding to Mg²⁺-bound ATP/GTP (denoted as NTP) in solution affect the cofactor's conformation and subsequent recognition by the host protein? (4) How do NTP-Mg-Li complexes modulate the properties of the respective cellular receptors and signal-transducing proteins? We show that Li⁺ may displace Na⁺ from allosteric Na⁺-binding sites in certain GPCRs and stabilize inactive conformations, preventing these receptors from relaying signal to the respective G-proteins. It may also displace Mg²⁺ in enzymes containing highly cationic Mg²⁺-binding sites such as GSK3β, but not in enzymes containing Mg²⁺-binding sites with low or zero charge. We further show that Li⁺ binding to Mg²⁺-NTP in water does not alter the NTP conformation, which is locked by all three phosphates binding to Mg²⁺. However, bound lithium in the form of [NTP-Mg-Li]^2- dianions can activate or inhibit the host protein depending on the NTP-binding pocket's shape, which determines the metal-binding mode: The ATP-binding pocket's shape in the P2X receptor is complementary to the native ATP-Mg solution conformation and nicely fits [ATP-Mg-Li]^2-. However, since the ATP βγ phosphates bind Li⁺, bimetallic [ATP-Mg-Li]^2- may be more resistant to hydrolysis than the native cofactor, enabling ATP to reside longer in the binding site and elicit a prolonged P2X response. In contrast, the elongated GTP-binding pockets in G-proteins allow only two GTP phosphates to bind Mg²⁺, so the GTP conformation is no longer "triply-locked". Consequently, Li⁺ binding to GTP-Mg can significantly alter the native cofactor's structure, lowering the activated G-protein level, thus attenuating hyperactive G-protein-mediated signaling in bipolar patients. In summary, we have presented a larger "connected" picture of lithium's diverse effects based on its competition as a free monocation with native cations or as a phosphate-bound polyanionic complex modulating the host protein function.

Perspectives, attitude, and practice of lithium prescription among psychiatrists in India

INTRODUCTION

Lithium "the magic pill" past its discovery remained the respite for patients with bipolar disorders for decades. The prescriptions of lithium were replaced by other drugs because of the cumbersome monitoring, adverse effect profile, narrow therapeutic index, and frequent comorbidities in patients. The objectives of this study were to understand the knowledge, attitude, and practice of lithium by a subset of psychiatrists in India, which will help us understand the theory-practice gap and for devising strategies to bridge the existing gap.

MATERIALS AND METHODS

The current study was an online survey which included 103 psychiatrists from India of either gender and any age group. Predesigned questionnaire about the knowledge, attitude, and practice of lithium use was circulated for 1 month (March 2018). We received 135 responses (31% response rate), of which 32 were incomplete. Hence, the total sample of psychiatrists included in the study was 103.

RESULTS

The results suggest that most practitioners included in the survey had knowledge about the effects, adverse effects, and the monitoring protocols and were comfortable in using lithium in patients on outpatient basis. Despite being aware of the indications, the psychiatrists were skeptical in starting lithium due to multitude of perceived barriers such as comorbidities, patient's low adherence to blood monitoring, and adverse effects.

CONCLUSIONS

Clinicians should be well aware of the adverse effects, monitoring protocols, which will help them to use lithium in a more appropriate manner.

Putative Mechanisms of Action and Clinical Use of Lithium in Children and Adolescents: A Critical Review

Background:

Lithium is a first-line treatment for bipolar disorder in adults, but its mechanism of action is still far from clear. Furthermore, evidences of its use in pediatric populations are sparse, not only for bipolar disorders, but also for other possible indications.

Objectives:

To provide a synthesis of published data on the possible mechanisms of action of lithium, as well as on its use in pediatric samples, including pharmacokinetics, efficacy, and safety data.

Methods:

Clinical trials in pediatric samples with at least one standardized measure of efficacy/effectiveness were included in this review. We considered: i) randomized and open label trials, ii) combination studies iii) augmentation studies iv) case series including at least 5 patients.

Results:

Different and non-alternative mechanisms of action can explain the clinical efficacy of lithium. Clinical studies in pediatric samples suggest that lithium is effective in managing manic symptoms/episodes of bipolar disorder, both in the acute phase and as maintenance strategy. Efficacy on depressive symptoms/phases of bipolar disorder is much less clear, while studies do not support its use in unipolar depression and severe mood dysregulation. Conversely, it may be effective on aggression in the context of conduct disorder. Other possible indications, with limited published evidence, are the acute attacks in Kleine-Levin syndrome, behavioral symptoms of X-fragile syndrome, and the management of clozapine- or chemotherapy- induced neutropenia. Generally, lithium resulted relatively safe.

Conclusions:

Lithium seems an effective and well-tolerated medication in pediatric bipolar disorder and aggression, while further evidences are needed for other clinical indications.

Lithium for acute mania

BACKGROUND

Bipolar disorder is a common condition associated with high morbidity; developing efficacious, safe treatments is therefore essential. Lithium is an effective maintenance treatment for bipolar disorder. It acts as mood stabiliser and reduces the risk of suicide. However, evidence assessing the efficacy of lithium in the treatment of acute mania is less robust. Current evidence-based guidelines cite multiple anti-dopaminergic and mood-stabilising agents as initial treatments: more definite evidence is needed to decide if lithium should be the first-line therapy.

OBJECTIVES

1. To assess the effects of lithium in comparison with placebo or other active treatment in alleviating the acute symptoms of a manic or mixed episode in people with bipolar disorder.2. To review the acceptability and tolerability of treatment with lithium in comparison with placebo or other active treatments in alleviating the acute symptoms of a manic or mixed episode in people with bipolar disorder.

SEARCH METHODS

We searched the Cochrane Common Mental Disorders Controlled Trials Register, CENTRAL, MEDLINE, Embase, and PsycINFO. We also searched the World Health Organization trials portal (ICTRP) and ClinicalTrials.gov. We checked the reference lists of all included studies and relevant systematic reviews. We have incorporated studies from searches to 18 May 2018 into the current analyses.

SELECTION CRITERIA

Prospective randomised controlled studies comparing lithium with placebo or alternative drug treatment in treatment of acute mania. We included anyone with bipolar disorder, male and female, of any age.

DATA COLLECTION AND ANALYSIS

At least two review authors independently extracted data and assessed methodological quality. We used odds ratios (ORs) to analyse binary efficacy outcomes, and mean differences (MDs) or standardised mean differences (SMDs) for continuously distributed outcomes. We used a fixed-effect model unless heterogeneity was moderate or substantial, in which case we used a random-effects model. We used Review Manager 5 to analyse data. We assessed the certainty of evidence for individual outcomes using the GRADE approach.

MAIN RESULTS

We found 36 randomised controlled studies comparing lithium with placebo, one of 12 drugs, or electroconvulsive therapy for treatment of acute mania. Studies included male and female participants (n = 4220), of all ages, who all fitted criteria for a manic episode within the context of a diagnosis of bipolar disorder.Risk of bias was variable; 12 studies had a high risk of bias in one domain and 27 gave inadequate information on randomisation leading to an 'unclear' rating for selection bias.Lithium versus placeboHigh-certainty evidence found that lithium was an effective treatment for acute mania and was more effective than placebo at inducing a response (OR 2.13, 95% confidence interval (CI) 1.73 to 2.63; participants = 1707; studies = 6; I² = 16%; high-certainty evidence), or remission (OR 2.16, 95% CI 1.73 to 2.69; participants = 1597; studies = 5; I² = 21%; high-certainty evidence).Lithium was more likely than placebo to cause tremor (OR 3.25, 95% CI 2.10 to 5.04; participants = 1241; studies = 6; I² = 0%; high-certainty evidence), and somnolence (OR 2.28, 95% CI 1.46 to 3.58; participants = 1351; studies = 7; I² = 0%; high-certainty evidence).There was insufficient evidence to determine the effect of lithium for all-cause dropouts (OR 0.76; 95% CI 0.46 to 1.25; participants = 1353; studies = 7; I² = 75%; moderate-certainty evidence), and weight gain (OR 1.48, 95% CI 0.56 to 3.92; participants = 735, studies = 3; I²= 51%; moderate-certainty evidence).Lithium versus antipsychotics or mood stabilisersFor the outcome of inducing a response, there was only very low-certainty evidence regarding lithium compared to haloperidol (MD -2.40, 95% CI -6.31 to 1.50; participants = 80; studies = 3; I² = 95%), quetiapine (OR 0.66, 95% CI 0.28 to 1.55; participants = 335; studies = 2; I² = 71%), and carbamazepine (SMD 0.21, 95% CI -0.18 to 0.60; participants = 102; studies = 3; I² = 0%).Lithium was probably less likely to induce a response than olanzapine (OR 0.44, 95% CI 0.20 to 0.94; participants = 180; studies = 2; I² = 0%; moderate-certainty evidence).Lithium may be less likely to induce a response than risperidone (MD 7.28, 95% CI 5.22 to 9.34; participants = 241; studies = 3; I² = 49%; low-certainty evidence).There was no evidence of a difference between lithium and valproate (OR 1.22, 95% CI 0.87 to 1.70; participants = 607; studies = 5; I² = 22%; moderate-certainty evidence).There was moderate-certainty evidence that lithium was more effective than topiramate at treating acute mania (OR 2.28, 95% CI 1.63 to 3.20; participants = 660; studies = 1).Data on adverse events for these comparisons contained too few studies to provide high-certainty evidence.

AUTHORS' CONCLUSIONS

This systematic review indicates that lithium is more effective than placebo as a treatment for acute mania but increases the risk for somnolence and tremor. Limited evidence suggests little or no difference between lithium and other mood stabilisers (valproate, carbamazepine) or antipsychotics (risperidone, quetiapine, haloperidol). Olanzapine may be an exception, as it is probably slightly more effective than lithium. There is uncertain evidence that risperidone may also be more effective than lithium. Lithium is probably more effective at treating acute mania than topiramate. When compared to placebo, lithium was more likely to cause adverse events. However, when compared to other drugs, too few studies provided data on adverse effects to provide high-certainty evidence. More, rigorously designed, large-scale studies are needed to definitively conclude if lithium is superior to other interventions in treating acute mania.

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.

Metabolomics Analyses of 14 Classical Neurotransmitters by GC-TOF with LC-MS Illustrates Secretion of 9 Cell-Cell Signaling Molecules from Sympathoadrenal Chromaffin Cells in the Presence of Lithium

The classical small molecule neurotransmitters are essential for cell-cell signaling in the nervous system for regulation of behaviors and physiological functions. Metabolomics approaches are ideal for quantitative analyses of neurotransmitter profiles but have not yet been achieved for the repertoire of 14 classical neurotransmitters. Therefore, this study developed targeted metabolomics analyses by full scan gas chromatography/time-of-flight mass spectrometry (GC-TOF) and hydrophilic interaction chromatography-QTRAP mass spectrometry (HILIC-MS/MS) operated in positive ionization mode for identification and quantitation of 14 neurotransmitters consisting of acetylcholine, adenosine, anandamide, aspartate, dopamine, epinephrine, GABA, glutamate, glycine, histamine, melatonin, norepinephrine, serine, and serotonin. GC-TOF represents a new metabolomics method for neurotransmitter analyses. Sensitive measurements of 11 neurotransmitters were achieved by GC-TOF, and three neurotransmitters were analyzed by LC-MS/MS (acetylcholine, anandamide, and melatonin). The limits of detection (LOD) and limits of quantitation (LOQ) were assessed for linearity for GC-TOF and LC-MS/MS protocols. In neurotransmitter-containing dense core secretory vesicles of adrenal medulla, known as chromaffin granules (CG), metabolomics measured the concentrations of 9 neurotransmitters consisting of the catecholamines dopamine, norepinephrine, and epinephrine, combined with glutamate, serotonin, adenosine, aspartate, glycine, and serine. The CG neurotransmitters were constitutively secreted from sympathoadrenal chromaffin cells in culture. Nicotine- and KCl-stimulated release of the catecholamines and adenosine. Lithium, a drug used for the treatment of bipolar disorder, decreased the constitutive secretion of dopamine and norepinephrine and decreased nicotine-stimulated secretion of epinephrine. Lithium had no effect on other secreted neurotransmitters. Overall, the newly developed GC-TOF with LC-MS/MS metabolomics methods for analyses of 14 neurotransmitters will benefit investigations of neurotransmitter regulation in biological systems and in human disease conditions related to drug treatments.

Genetic Deletion of P2Y2 Receptor Offers Long-Term (5 Months) Protection Against Lithium-Induced Polyuria, Natriuresis, Kaliuresis, and Collecting Duct Remodeling and Cell Proliferation

Chronic lithium administration for the treatment of bipolar disorder leads to nephrogenic diabetes insipidus (NDI), characterized by polyuria, natriuresis, kaliuresis, and collecting duct remodeling and cell proliferation among other features. Previously, using a 2-week lithium-induced NDI model, we reported that P2Y2 receptor (R) knockout mice are significantly resistant to polyuria, natriuresis, kaliuresis, and decrease in AQP2 protein abundance in the kidney relative to wild type mice. Here we show this protection is long-lasting, and is also associated with significant amelioration of lithium-induced collecting duct remodeling and cell proliferation. Age-matched wild type and knockout mice were fed regular (n = 5/genotype) or lithium-added (40 mmol/kg chow; n = 10/genotype) diet for 5 months and euthanized. Water intake, urine output and osmolality were monitored once in every month. Salt blocks were provided to mice on lithium-diet to prevent sodium loss. At the end of 5 months mice were euthanized and serum and kidney samples were analyzed. There was a steady increase in lithium-induced polyuria, natriuresis and kaliuresis in wild type mice over the 5-month period. Increases in these urinary parameters were very low in lithium-fed knockout mice, resulting in significantly widening differences between the wild type and knockout mice. Terminal AQP2 and NKCC2 protein abundances in the kidney were significantly higher in lithium-fed knockout vs. wild type mice. There were no significant differences in terminal serum lithium or sodium levels between the wild type and knockout mice. Confocal immunofluorescence microscopy revealed that lithium-induced marked remodeling of collecting duct with significantly increased proportion of [H+]-ATPase-positive intercalated cells and decreased proportion of AQP2-positive principal cells in the wild type, but not in knockout mice. Lithium-induced collecting duct cell proliferation (indicated by Ki67 labeling), was significantly lower in knockout vs. wild type mice. This is the first piece of evidence that purinergic signaling is potentially involved in lithium-induced collecting duct remodeling and cell proliferation. Our results demonstrate that genetic deletion of P2Y2-R protects against the key structural and functional alterations in Li-induced NDI, and underscore the potential utility of targeting this receptor for the treatment of NDI in bipolar patients on chronic lithium therapy.

Challenging the Negative Perception of Lithium and Optimizing Its Long-Term Administration

The use of lithium for the prevention of recurrences in mood disorders has a 55-year history. Nowadays, lithium is universally accepted as the first-choice mood-stabilizer (MS) for maintenance treatment of bipolar disorder. In addition to its mood-stabilizing properties, lithium exerts anti-suicidal, immunomodulatory and neuroprotective action which may further substantiate its clinical usefulness. Despite these facts, the use of lithium in mood disorders has been greatly underutilized. The reasons include the introduction and promoting other MS as well as a perception of lithium as a “toxic drug” due to its side effects, mainly thyroid, renal and cognitive disturbances. The trends in lithium prescription in recent decades show relative stability or a decline at the expense of other mood-stabilizing drugs, both first generation (valproate) and second generation (olanzapine, quetiapine, lamotrigine). In this review article, the negative perception of lithium by some clinicians will be challenged. First, the data showing lithium superiority over other MS will be presented. Second, the lithium-induced side effects which can make a challenge for a more frequent application of this drug will be delineated, and their proper management described. Finally, an issue of benefits of long-term administration of lithium will be discussed, including the phenomenon of the “excellent lithium responders” (ER) as well as a subject of starting lithium prophylaxis early in the course of the illness. This review article is based on the 47-year experience with lithium therapy by the author of the article.

Molecular Mechanisms of Lithium Action: Switching the Light on Multiple Targets for Dementia Using Animal Models

Lithium has long been used for the treatment of psychiatric disorders, due to its robust beneficial effect as a mood stabilizing drug. Lithium’s effectiveness for improving neurological function is therefore well-described, stimulating the investigation of its potential use in several neurodegenerative conditions including Alzheimer’s (AD), Parkinson’s (PD) and Huntington’s (HD) diseases. A narrow therapeutic window for these effects, however, has led to concerted efforts to understand the molecular mechanisms of lithium action in the brain, in order to develop more selective treatments that harness its neuroprotective potential whilst limiting contraindications. Animal models have proven pivotal in these studies, with lithium displaying advantageous effects on behavior across species, including worms (C. elegans), zebrafish (Danio rerio), fruit flies (Drosophila melanogaster) and rodents. Due to their susceptibility to genetic manipulation, functional genomic analyses in these model organisms have provided evidence for the main molecular determinants of lithium action, including inhibition of inositol monophosphatase (IMPA) and glycogen synthase kinase-3 (GSK-3). Accumulating pre-clinical evidence has indeed provided a basis for research into the therapeutic use of lithium for the treatment of dementia, an area of medical priority due to its increasing global impact and lack of disease-modifying drugs. Although lithium has been extensively described to prevent AD-associated amyloid and tau pathologies, this review article will focus on generic mechanisms by which lithium preserves neuronal function and improves memory in animal models of dementia. Of these, evidence from worms, flies and mice points to GSK-3 as the most robust mediator of lithium’s neuro-protective effect, but it’s interaction with downstream pathways, including Wnt/β-catenin, CREB/brain-derived neurotrophic factor (BDNF), nuclear factor (erythroid-derived 2)-like 2 (Nrf2) and toll-like receptor 4 (TLR4)/nuclear factor-κB (NFκB), have identified multiple targets for development of drugs which harness lithium’s neurogenic, cytoprotective, synaptic maintenance, anti-oxidant, anti-inflammatory and protein homeostasis properties, in addition to more potent and selective GSK-3 inhibitors. Lithium, therefore, has advantages as a multi-functional therapy to combat the complex molecular pathology of dementia. Animal studies will be vital, however, for comparative analyses to determine which of these defense mechanisms are most required to slow-down cognitive decline in dementia, and whether combination therapies can synergize systems to exploit lithium’s neuro-protective power while avoiding deleterious toxicity.

Lithium as a disease-modifying agent for prion diseases

Prion diseases still remain incurable despite multiple efforts to develop a treatment. Therefore, it is important to find strategies to at least reduce the symptoms. Lithium has been considered as a neuroprotective agent for years, and the objective of this preclinical study was to evaluate the efficacy of lithium delivered as a water-in-oil microemulsion (Aonys^®). This delivery system allows using low doses of lithium and to avoid the toxicity observed in chronic treatments. C57BL/6J mice were intracranially inoculated with ME7 prion-infected brain homogenates and then were treated with lithium from day 90 post inoculation until their death. Lithium was administered at traditional doses (16 mg/kg/day) by the gavage route and at lower doses (40 or 160 µg/kg/day; Aonys^®) by the rectal mucosa route. Low doses of lithium (Aonys^®) improved the survival of prion-inoculated mice, and also decreased vacuolization, astrogliosis, and neuronal loss compared with controls (vehicle alone). The extent of the protective effects in mice treated with low-dose lithium was comparable or even higher than what was observed in mice that received lithium at the traditional dose. These results indicate that lithium administered using this innovative delivery system could represent a potential therapeutic approach not only for prion diseases but also for other neurodegenerative diseases.

Lithium, Stress, and Resilience in Bipolar Disorder: Deciphering this key homeostatic synaptic plasticity regulator

BACKGROUND

Lithium is the lightest metal and the only mood stabilizer that has been used for over half a century for the treatment of bipolar disorder (BD). As a small ion, lithium is omnipresent, and consequently, its molecular mechanisms and targets are widespread. Currently, lithium is a crucial pharmacotherapy for the treatment of acute mood episodes, prophylactic therapy, and suicide prevention in BD. Besides, lithium blood level is the most widely used biomarker in clinical psychiatry. The concept of stress in BD characterizes short- and long-term deleterious effects at multiple levels (from genes to behaviors) and the ability to establish homeostatic regulatory mechanisms to either prevent or reverse these effects. Within this concept, lithium has consistently shown anti-stress effects, by normalizing components across several levels associated with BD-induced impairments in cellular resilience and plasticity.

METHODS

A literature search for biomarkers associated with lithium effects at multiple targets, with a particular focus on those related to clinical outcomes was performed. An extensive search of the published literature using PubMed, Medline and Google Scholar was performed. Example search terms included lithium, plasticity, stress, efficacy, and neuroimaging. Articles determined by the author to focus on lithium's impact on neural plasticity markers (central and periphery) and clinical outcomes were examined in greater depth. Relevant papers were evaluated, selected and included in this review.

RESULTS

Lithium induces neurotrophic and neuroprotective effects in a wide range of preclinical and translational models. Lithium's neurotrophic effects are related to the enhancement of cellular proliferation, differentiation, growth, and regeneration, whereas its neuroprotective effects limit the progression of neuronal atrophy or cell death following the onset of BD. Lithium's neurotrophic and neuroprotective effects seem most pronounced in the presence of pathology, which again supports its pivotal role as an active homeostatic regulator.

LIMITATIONS

Few studies associated with clinical outcomes. Due to space limitations, the author was unable to detail all findings, in special those originated from preclinical studies.

CONCLUSIONS

These results support a potential role for biomarkers involved in neuroprotection and activation of plasticity pathways in lithium's clinical response. Evidence supporting this model comes from results evaluating macroscopic and microscopic brain structure as well neurochemical findings in vivo from cellular to sub-synaptic (molecules and intracellular signaling) compartments using central and peripheral biomarkers. Challenges to precisely decipher lithium's biological mechanisms involved in its therapeutic profile include the complex nature of the illness and clinical subtypes, family history and comorbid conditions. In the context of personalized medicine, it is necessary to validate predictive biomarkers of response to lithium by designing longitudinal clinical studies during mood episodes and associated clinical dimensions in BD.

How Native and Non-Native Cations Bind and Modulate the Properties of GTP/ATP

Adenosine triphosphate (ATP) and guanosine triphosphate (GTP) exist in physiological solution mostly bound to cations. Interestingly, their cellular Mg²⁺-bound forms have been shown to bind Li⁺, a first-line drug for bipolar disorder. However, solution structures of NTP/NDP (N = A or G) bound to Li⁺ and/or Mg²⁺ have not been solved, thus precluding knowledge of how the native Mg²⁺-bound cofactor conformation changes upon binding non-native Li⁺ and/or switching its environment from aqueous solution to proteins. Using well-calibrated methods that reproduce experimental structural and thermodynamic parameters of several Mg²⁺/Li⁺-nucleotide complexes, we show that the native NTP/NDP-Mg²⁺ cofactor adopts a "folded" conformation in water that remains unperturbed upon Li⁺ binding. We further show that the ATP-binding pockets of receptors such as P2X are complementary in shape to the "folded" ATP-Mg²⁺ solution structure, whereas the elongated GTP-binding pockets found in G-proteins necessitate the GTP-Mg²⁺ cofactor to undergo a conformational change from its "folded" conformation in solution to an extended one upon G-protein binding. Implications of the findings on how Li⁺, in its bound state, can manifest its therapeutic effects are discussed.

Association between duration of lithium exposure and hippocampus/amygdala volumes in type I bipolar disorder

BACKGROUND

Prior studies on the effects of lithium on limbic and subcortical gray matter volumes are mixed. It is possible that discrepant findings may be explained by the duration of lithium exposure. We investigated this issue in individuals with type I bipolar disorder (BP-I).

METHODS

Limbic and subcortical gray matter volume was measured using FreeSurfer in 60 subjects: 15 with BP-I without prior lithium exposure [no-exposure group (NE)]; 15 with BP-I and lithium exposure < 24 months [short-exposure group (SE)]; 15 with BP-I and lithium exposure > 24 months [long-exposure group (LE)]; and 15 healthy controls (HC).

RESULTS

No differences in limbic and subcortical gray matter volumes were found between LE and HC. Hippocampal and amygdalar volumes were larger bilaterally in both LE and HC when compared to NE. Amygdalar volumes were larger bilaterally in SE when compared to NE but did not differ from LE. Hippocampal volumes were smaller bilaterally in SE when compared to LE and HC but did not differ from NE. No between-group differences on subcortical gray matter or other limbic structure volumes were observed.

LIMITATIONS

Cross-sectional design and concurrent treatment with other medications limit attribution of between-group differences to lithium exposure alone.

CONCLUSIONS

The effect of lithium exposure on limbic and subcortical gray matter volumes appears to be time-dependent and relatively specific to the hippocampus and the amygdala, with short-term effects on the amygdala and long-term effects on both structures. These results support the clinical importance of long-term lithium treatment in BP-I.

Competition between Li+ and Na+ in sodium transporters and receptors: Which Na+-Binding sites are "therapeutic" Li+ targets?

Li⁺ (turquoise), the better charge acceptor, can displace Na⁺ (purple) bound by only one or two aa residues in buried sites. Thus, Li⁺ can displace Na⁺ bound by Asp^– and Ser in the A_2AAR/β₁AR receptor and enhance the metal site's stability, thus prohibiting structural distortions induced by agonist binding, leading to lower cytosolic levels of activated G-proteins, which are hyperactive in bipolar disorder patients.

Sodium (Na⁺) acts as an indispensable allosteric regulator of the activities of biologically important neurotransmitter transporters and G-protein coupled receptors (GPCRs), which comprise well-known drug targets for psychiatric disorders and addictive behavior. How selective these allosteric Na⁺-binding sites are for the cognate cation over abiogenic Li⁺, a first-line drug to treat bipolar disorder, is unclear. Here, we reveal how properties of the host protein and its binding cavity affect the outcome of the competition between Li⁺ and Na⁺ for allosteric binding sites in sodium transporters and receptors. We show that rigid Na⁺-sites that are crowded with multiple protein ligands are well-protected against Li⁺ attack, but their flexible counterparts or buried Na⁺-sites containing only one or two protein ligands are vulnerable to Li⁺ substitution. These findings suggest a novel possible mode of Li⁺ therapeutic action: By displacing Na⁺ bound by ≤2 protein ligands in buried GPCR sites and stabilizing the receptor's inactive state, Li⁺ could prohibit conformational changes to an active state, leading to lower cytosolic levels of activated guanine nucleotide-binding proteins, which are hyperactive/overexpressed in bipolar disorder patients.

Amygdala and regional volumes in treatment-resistant versus nontreatment-resistant depression patients

BACKGROUND

Although treatment-resistant and nontreatment-resistant depressed patients show structural brain anomalies relative to healthy controls, the difference in regional volumetry between these two groups remains undocumented.

METHODS

A whole-brain voxel-based morphometry (VBM) analysis of regional volumes was performed in 125 participants' magnetic resonance images obtained on a 1.5 Tesla scanner; 41 had treatment-resistant depression (TRD), 40 nontreatment-resistant depression (non-TRD), and 44 were healthy controls. The groups were comparable for age and gender. Bipolar/unipolar features as well as pharmacological treatment classes were taken into account as covariates.

RESULTS

TRD patients had higher gray matter (GM) volume in the left and right amygdala than non-TRD patients. No difference was found between the TRD bipolar and the TRD unipolar patients, or between the non-TRD bipolar and non-TRD unipolar patients. An exploratory analysis showed that lithium-treated patients in both groups had higher GM volume in the superior and middle frontal gyri in both hemispheres.

CONCLUSIONS

Higher GM volume in amygdala detected in TRD patients might be seen in perspective with vulnerability to chronicity, revealed by medication resistance.

[Impact of natural lithium ressources on suicide mortality in Chile 2000-2009: a geographical analysis]

BACKGROUND

There is increasing evidence for the hypothesis that lithium salts at naturally occurring levels in drinking water may have a moderating effect on suicide rates of the exposed population. The aim of this study was to examine whether the lithium rich Atacama region in Chile is associated with lower suicide mortality in comparison to other regions.

METHODS

Suicide data was acquired from the Chilean Ministry of Health. Socio-economic variables (rate of unemployment, urbanity, median household income, percentage of indeginous population) were obtained for all regions of Chile from the national statistical institute. We calculated annual suicide rates per 100,000 for each group for the years 2000-2009 and tested the hypothesis that suicide rates are lower in lithium rich regions in comparison to other regions of Chile.

RESULTS

The lithium rich Atacama Desert shows a significantly lower suicide rate (9.99 per 100,000) in comparison to other parts of Chile (12.50 per 100,000) (t = 4.75, df = 18, p < 0.001).

CONCLUSIONS

Chilean regions rich in naturally occurring lithium salts show lower suicide mortality rates in comparison to other regions. Although causality cannot be proven by this design, these findings add to previous findings and warrant further research on the effects of naturally occurring low-dose lithium on health.