High lithium levels in tobacco may account for reduced incidences of both Parkinson's disease and melanoma in smokers through enhanced β-catenin-mediated activity

Lithium Enhances Autophagy and Cell Death in Skin Melanoma: An Ultrastructural and Immunohistochemical Study

Lithium is an inhibitor of glycogen synthase kinase 3 beta, which is traditionally used in the treatment of bipolar disorders and has antitumor effects. The aim of the current study was to determine if lithium salt causes autophagy and apoptosis in skin melanoma cells to enhance cell death. Light microscopy, transmission electron microscopy, immunohistochemistry, and immunofluorescence were used to study the mechanism of action of lithium carbonate in B16 melanoma cells in vivo. Proliferating cell nuclear antigen immunofluorescence assay revealed that the proliferation of B16 melanoma cells was suppressed by lithium treatment for 7 days. Electron microscopy demonstrated a significant increase in the number of autophagic vacuoles in lithium-treated cells relative to control. In addition, levels of autophagy markers LC3 beta and LAMP1 found in lithium-treated tumor xenografts were higher than levels of these markers in the control tumors. Lithium induced caspase-3 expression and apoptotic cell death in tumor cells. Thus, lithium carbonate is the compound that inhibits cell proliferation and stimulates cell death in melanoma cells through induction of autophagy and apoptosis. Stimulation of autophagy by lithium could contribute to the development of autophagic cell death in tumor cells.

A Proposed TUSC7/miR-211/Nurr1 ceRNET Might Potentially be Disturbed by a cer-SNP rs2615499 in Breast Cancer

Evidence and in silico analyses showed that TUSC7, miR-211, and Nurr1 may be involved in BC pathogenesis by ceRNET signaling axis. This study aimed to investigate the potential role of TUSC7/miR-211/Nurr1 ceRNET and rs2615499 variant as a novel cer-SNP in BC subjects. The expression assays were conducted by qPCR on tumor tissues (n = 50), tumor-adjacent normal tissues (TANTs) (n = 50), and clinically healthy control tissues (n = 50). The expression of TUSC7 and Nurr1 significantly decreased, but the level of miR-211 significantly increased in tumor tissues compared to TANTs and healthy normal tissues. Altered expression of TUSC7 and miR-211 was associated with poor prognosis of patients. The Nurr1 exhibited a double-edged sword-like activity in BC. In addition, TUSC7, Nurr1, and miR-211 expressions were significantly related to a novel BC-associated rs2615499 (A > C) located in the miR-211 binding site on Nurr1 3'-UTR. In the second part of the study, a case-control study was performed on BC patients (n = 100) and matched healthy controls (n = 100). The genomic DNA was isolated and genotyping was performed using Tetra-Primer ARMS PCR. The CC and AC genotypes were associated with higher expression levels of Nurr1 and worse outcomes of the disease. Our findings revealed that TUSC7 functions as a tumor suppressor in BC potentially via miR-211/Nurr1, which might be disturbed by the cer-SNP rs2615499. However, functional studies are needed to validate these results.

Lithium promotes recovery after spinal cord injury

Lithium is associated with oxidative stress and apoptosis, but the mechanism by which lithium protects against spinal cord injury remains poorly understood. In this study, we found that intraperitoneal administration of lithium chloride (LiCl) in a rat model of spinal cord injury alleviated pathological spinal cord injury and inhibited expression of tumor necrosis factor α, interleukin-6, and interleukin 1 β. Lithium inhibited pyroptosis and reduced inflammation by inhibiting Caspase-1 expression, reducing the oxidative stress response, and inhibiting activation of the Nod-like receptor protein 3 inflammasome. We also investigated the neuroprotective effects of lithium intervention on oxygen/glucose-deprived PC12 cells. We found that lithium reduced inflammation, oxidative damage, apoptosis, and necrosis and up-regulated nuclear factor E2-related factor 2 (Nrf2) and heme oxygenase-1 in PC12 cells. All-trans retinoic acid, an Nrf2 inhibitor, reversed the effects of lithium. These results suggest that lithium exerts anti-inflammatory, anti-oxidant, and anti-pyroptotic effects through the Nrf2/heme oxygenase-1 pathway to promote recovery after spinal cord injury. This study was approved by the Animal Ethics Committee of Xi’an Jiaotong University (approval No. 2018-2053) on October 23, 2018.

Cholinergic Receptor Modulation as a Target for Preventing Dementia in Parkinson's Disease

Parkinson’s disease (PD) is a neurodegenerative condition characterized by the loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc) in the midbrain resulting in progressive impairment in cognitive and motor abilities. The physiological and molecular mechanisms triggering dopaminergic neuronal loss are not entirely defined. PD occurrence is associated with various genetic and environmental factors causing inflammation and mitochondrial dysfunction in the brain, leading to oxidative stress, proteinopathy, and reduced viability of dopaminergic neurons. Oxidative stress affects the conformation and function of ions, proteins, and lipids, provoking mitochondrial DNA (mtDNA) mutation and dysfunction. The disruption of protein homeostasis induces the aggregation of alpha-synuclein (α-SYN) and parkin and a deficit in proteasome degradation. Also, oxidative stress affects dopamine release by activating ATP-sensitive potassium channels. The cholinergic system is essential in modulating the striatal cells regulating cognitive and motor functions. Several muscarinic acetylcholine receptors (mAChR) and nicotinic acetylcholine receptors (nAChRs) are expressed in the striatum. The nAChRs signaling reduces neuroinflammation and facilitates neuronal survival, neurotransmitter release, and synaptic plasticity. Since there is a deficit in the nAChRs in PD, inhibiting nAChRs loss in the striatum may help prevent dopaminergic neurons loss in the striatum and its pathological consequences. The nAChRs can also stimulate other brain cells supporting cognitive and motor functions. This review discusses the cholinergic system as a therapeutic target of cotinine to prevent cognitive symptoms and transition to dementia in PD.

Targeting Wnt signaling pathway by polyphenols: implication for aging and age-related diseases

Age is an important risk factor for different diseases. The same mechanisms that promote aging are involved in the development and progression of age-associated diseases. Polyphenols are organic compounds found in fruits and vegetables. Due to their beneficial properties (e.g. antioxidant and anti-inflammatory), polyphenols have been extensively used for treating chronic diseases. To exert their functions, polyphenols target various molecular mechanisms and signaling pathways, such as mTOR, NF-κB, and Wnt/β-catenin. Wnt signaling is a critical pathway for developmental processes. Besides, dysregulation of this signaling pathway has been observed in various diseases. Several investigations have been conducted on Wnt inhibitors at pre-clinical stages, showing promising results. Herein, we review the studies dealing with the role of polyphenols in targeting the Wnt signaling pathways in aging processes and age-associated diseases, including cancer, diabetes, Alzheimer's disease, osteoporosis, and Parkinson's disease.

Lithium Chloride Protects against Sepsis-Induced Skeletal Muscle Atrophy and Cancer Cachexia

Inflammation-mediated skeletal muscle wasting occurs in patients with sepsis and cancer cachexia. Both conditions severely affect patient morbidity and mortality. Lithium chloride has previously been shown to enhance myogenesis and prevent certain forms of muscular dystrophy. However, to our knowledge, the effect of lithium chloride treatment on sepsis-induced muscle atrophy and cancer cachexia has not yet been investigated. In this study, we aimed to examine the effects of lithium chloride using in vitro and in vivo models of cancer cachexia and sepsis. Lithium chloride prevented wasting in myotubes cultured with cancer cell-conditioned media, maintained the expression of the muscle fiber contractile protein, myosin heavy chain 2, and inhibited the upregulation of the E3 ubiquitin ligase, Atrogin-1. In addition, it inhibited the upregulation of inflammation-associated cytokines in macrophages treated with lipopolysaccharide. In the animal model of sepsis, lithium chloride treatment improved body weight, increased muscle mass, preserved the survival of larger fibers, and decreased the expression of muscle-wasting effector genes. In a model of cancer cachexia, lithium chloride increased muscle mass, enhanced muscle strength, and increased fiber cross-sectional area, with no significant effect on tumor mass. These results indicate that lithium chloride exerts therapeutic effects on inflammation-mediated skeletal muscle wasting, such as sepsis-induced muscle atrophy and cancer cachexia.

Preventive treatments to slow substantia nigra damage and Parkinson's disease progression: A critical perspective review

Restoring the lost physiological functions of the substantia nigra in Parkinson's disease (PD) is an important goal of PD therapy. The present article reviews a) novel drug targets that should be targeted to slow PD progression, and b) clinical and experimental research data reporting new treatments targeting immune-inflammatory and oxidative pathways. A systematic search was performed based on the major databases, i.e., ScienceDirect, Web of Science, PubMed, CABI Direct databases, and Scopus, on relevant studies performed from 1900 to 2020. This review considers the crucial roles of mitochondria and immune-inflammatory and oxidative pathways in the pathophysiology of PD. High levels of oxidative stress in the substantia nigra, as well as modifications in glutathione regulation, contribute to mitochondrial dysfunction, with a decline in complex I of the mitochondrial electron transport chain reported in PD patients. Many papers suggest that targeting antioxidative systems is a crucial aspect of preventive and protective therapies, even justifying the utilization of N-acetylcysteine (NAC) supplementation to fortify the protection afforded by intracellular glutathione. Dietary recommended panels including ketogenetic diet, muscular exercise, nutraceutical supplementation including NAC, glutathione, nicotine, caffeine, melatonin, niacin, and butyrate, besides to nonsteroidal anti-inflammatory drugs (NSAIDs), and memantine treatment are important aspects of PD therapy. The integration of neuro-immune, antioxidant, and nutritional approaches to treatment should afford better neuroprotection, including by attenuating neuroinflammation, nitro-oxidative stress, mitochondrial dysfunction, and neurodegenerative processes. Future research should clarify the efficacy, and interactions, of nicotine receptor agonists, gut microbiome-derived butyrate, melatonin, and NSAIDs in the treatment of PD.