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

The hyperphosphorylation of tau is a central mechanism in the pathogenesis of Alzheimer's disease (AD). Lithium is a potent inhibitor of glycogen synthase kinase-3beta (GSK3ß), the most important tau kinase in neurons, and may also affect tau phosphorylation by modifying the expression and/or activity of other kinases, such as protein kinase A (PKA), Akt (PKB), and calcium calmodulin kinase-II (CaMKII). The aim of the present study is to determine the effect of chronic lithium treatment on the protein expression of tau and its major kinases in cortical and hippocampal neurons, at distinct working concentrations. Primary cultures of cortical and hippocampal neurons were treated with sub-therapeutic (0.02 mM and 0.2 mM) and therapeutic (2 mM) concentrations of lithium for 7 days. Protein expression of tau and tau-kinases was determined by immunoblotting. An indirect estimate of GSK3ß activity was determined by the GSK3ß ratio (rGSKß). Statistically significant increments in the protein expression of tau and CaMKII were observed both in cortical and hippocampal neurons treated with subtherapeutic doses of lithium. GSK3ß activity was increased in cortical, but decreased in hippocampal neurons. Distinct patterns of changes in the expression of the remaining tau tau-kinases were observed: in cortical neurons, lithium treatment was associated with consistent decrements in Akt and PKA, whereas hippocampal neurons displayed increased protein expression of Akt and decreased PKA. Our results suggest that chronic lithium treatment may yield distinct biological effects depending on the concentration range, with regional specificity. We further suggest that hippocampal neurons may be more sensitive to the effect of lithium, presenting with changes in the expression of tau-related proteins at subtherapeutic doses, which may not be mirrored by the effects observed in cortical neurons.

Cardioprotective effects of amiodarone in a rat model of epilepsy-induced cardiac dysfunction.

Cardiac dysfunction is one of the leading causes of death in epilepsy. The anti-arrhythmic drug, amiodarone, is under investigation for its therapeutic effects in epilepsy. We aimed to evaluate the possible effects of amiodarone on cardiac injury during status epilepticus, as it can cause prolongation of the QT interval. Five rat groups were enrolled in the study; three control groups (1) Control, (2) Control-lithium and (3) Control-Amio, treated with 150 mg/kg/intraperitoneal amiodarone, (4) Epilepsy model, induced by sequential lithium/pilocarpine administration, and (5) the epilepsy-Amio group. The model group expressed a typical clinical picture of epileptiform activity confirmed by the augmented electroencephalogram alpha and beta spikes. The anticonvulsive effect of amiodarone was prominent, it diminished (p < 0.001) the severity of seizures and hence, deaths and reduced serum noradrenaline levels. In the model group, the electrocardiogram findings revealed tachycardia, prolongation of the corrected QT (QTc) interval, depressed ST segments and increased myocardial oxidative stress. The in-vitro myocardial performance (contraction force and - (df/dt)max ) was also reduced. Amiodarone decreased (p < 0.001) the heart rate, improved ST segment depression, and myocardial contractility with no significant change in the duration of the QTc interval. Amiodarone preserved the cardiac histological structure and reduced the myocardial injury markers represented by serum Troponin-I, oxidative stress and IL-1. Amiodarone pretreatment prevented the anticipated cardiac injury induced during epilepsy. Amiodarone possessed an anticonvulsive potential, protected the cardiac muscle and preserved its histological architecture. Therefore, amiodarone could be recommended as a protective therapy against cardiac dysfunction during epileptic seizures with favourable effect on seizure activity.

Lithium administered to pregnant, lactating and neonatal rats: entry into developing brain.

BACKGROUND: Little is known about the extent of drug entry into developing brain, when administered to pregnant and lactating women. Lithium is commonly prescribed for bipolar disorder. Here we studied transfer of lithium given to dams, into blood, brain and cerebrospinal fluid (CSF) in embryonic and postnatal animals as well as adults. METHODS: Lithium chloride in a clinically relevant dose (3.2 mg/kg body weight) was injected intraperitoneally into pregnant (E15-18) and lactating dams (birth-P16/17) or directly into postnatal pups (P0-P16/17). Acute treatment involved a single injection; long-term treatment involved twice daily injections for the duration of the experiment. Following terminal anaesthesia blood plasma, CSF and brains were collected. Lithium levels and brain distribution were measured using Laser Ablation Inductively Coupled Plasma-Mass Spectrometry and total lithium levels were confirmed by Inductively Coupled Plasma-Mass Spectrometry. RESULTS: Lithium was detected in blood, CSF and brain of all fetal and postnatal pups following lithium treatment of dams. Its concentration in pups' blood was consistently below that in maternal blood (30-35%) indicating significant protection by the placenta and breast tissue. However, much of the lithium that reached the fetus entered its brain. Levels of lithium in plasma fluctuated in different treatment groups but its concentration in CSF was stable at all ages, in agreement with known stable levels of endogenous ions in CSF. There was no significant increase of lithium transfer into CSF following application of Na+/K+ ATPase inhibitor (digoxin) in vivo, indicating that lithium transfer across choroid plexus epithelium is not likely to be via the Na+/K+ ATPase mechanism, at least early in development. Comparison with passive permeability markers suggested that in acute experiments lithium permeability was less than expected for diffusion but similar in long-term experiments at P2. CONCLUSIONS: Information obtained on the distribution of lithium in developing brain provides a basis for studying possible deleterious effects on brain development and behaviour in offspring of mothers undergoing lithium therapy.

Analysis of sex difference in the tubular reabsorption of lithium in rats.

Lithium is used in the treatment of bipolar disorder. We previously demonstrated that two types of transporters mediate the tubular reabsorption of lithium in rats, and suggested that sodium-dependent phosphate transporters play a role in lithium reabsorption with high affinity. In the present study, we examined sex differences in lithium reabsorption in rats. When lithium chloride was infused at 60 µg/min, creatinine clearance and the renal clearance of lithium were lower, and the plasma concentration of lithium was higher in female rats. These values reflected the higher fractional reabsorption of lithium in female rats. In rats infused with lithium chloride at 6 µg/min, the pharmacokinetic parameters of lithium examined were all similar in both sexes. The fractional reabsorption of lithium was decreased by foscarnet, a representative inhibitor of sodium-dependent phosphate transporters, in male and female rats when lithium chloride was infused at the low rate. Among the candidate transporters mediating lithium reabsorption examined herein, the mRNA expression of only PiT2, a sodium-dependent phosphate transporter, exhibited sexual dimorphism. The present results demonstrated sex differences in the tubular reabsorption of lithium with low affinity in rats.

The intervention of intestinal Wnt/ß-catenin pathway alters inflammation and disease severity of CIA.

Autoreactive T cell is one of the leading causes of immunological tolerance defects in the chronic inflammatory lesions of rheumatoid arthritis (RA). There have been several extracellular signals and intracellular pathways reported in regulating this process but largely remain unknown yet. In this study, we explored the roles of intestinal Wnt/ß-catenin on disease severity during collagen-induced arthritis model (CIA), an animal model of RA. We first testified the activity pattern Wnt/ß-catenin shifted by intragastric administration of LiCl and DKK-1 in the intestine by real-time PCR and WB analysis. The arthritis scores showing the disease severity in the DKK-1 group was significantly ameliorated compared with the control group at the late stage of the disease, while in the LiCl group, the scores were significantly elevated which was consistent with pathology score analysis of H&E staining. Next, ELISA was performed and showed that TNF-α and IL-17 in the LiCl group were significantly higher than that of the control group. IL-10 in the DKK-1 group was significantly higher than that in the LiCl-1 group and control group, P < 0.05. Flow cytometry of spleen T cells differentiation ratio showed that: Th1 from the DKK-1 and LiCl groups and Th17 from the LiCl group was significantly different from that of the blank model group, P < 0.05. Finally, we explored the effects of intestinal Wnt/ß-catenin on T cell differentiation regulator ROR-γt and TCF1 and found that both transcription factors were up-regulated in the LiCl group. Together, these data suggested the pro-information role of Wnt/ß-catenin pathway from the intestine in the CIA mouse, implying its use as a potential therapeutic target for the treatment of inflammatory diseases such as RA.

High dose lithium chloride causes colitis through activating F4/80 positive macrophages and inhibiting expression of Pigr and Claudin-15 in the colon of mice.

OBJECTIVE: Lithium chloride (LiCl) was a mood stabilizer for bipolar affective disorders and it could activate Wnt/ß-catenin signaling pathway both in vivo and in vitro. Colon is one of a very susceptible tissues to Wnt signaling pathway, and so it would be very essential to explore the toxic effect of a high dose of LiCl on colon. METHODS: C57BL/6 mice were injected intraperitoneally with 200 mg/kg LiCl one dose a day for 5 days to activate Wnt signal pathway in intestines. H&E staining was used to assess the colonic tissues of mice treated with high dose of LiCl. The expression of inflammation-associated genes and tight junction-associated genes in colons was measured using qPCR, Western blot and immunostaining methods. The gut microbiome was tested through 16S rDNA gene analysis. RESULTS: The differentiation of enteroendocrine cells in colon was inhibited by treatment of 200 mg/kg LiCl. The F4/80 positive macrophages in colon were activated by high dose of LiCl, and migrated from the submucosa to the lamina propria. The expression of pro-inflammatory genes TNFα and IL-1ß was increased in the colon of high dose of LiCl treated mice. Clostridium_sp_k4410MGS_306 and Prevotellaceae_UCG_001 were specific and predominant for the high dose of LiCl treated mice. The expression of IgA coding genes, Pigr and Claudin-15 was significantly decreased in the colon tissues of the high dose of LiCl treated mice. CONCLUSION: 200 mg/kg LiCl might cause the inflammation in colon of mice through activating F4/80 positive macrophages and inhibiting the expression of IgA coding genes in plasma cells and the expression of Pigr and Claudin-15 in colonic epithelial cells, providing evidences for the toxic effects of high dose of LiCl on colon.

Intraperitoneal injection of lithium chloride induces lateralized activation of the insular cortex in adult mice.

Insular cortex is a critical brain region that participates in the interoceptive sensations. Here, we combined the iDISCO + method and Fos immunostaining to confirm that the middle part of the right-side, but not the left-side, insular cortex in adult male mice is activated by intraperitoneal injection of lithium chloride. Lateralized activation of the insular cortex is also observed in adult female mice, but not in young or aged male mice. Furthermore, asymmetrical activation of the insular cortex was completely blocked when both sides of the vagal nerve are transected, whereas intravenous injection of lithium chloride has no effect on the insular activation. Combined together, these results indicate that the insular cortex unilaterally responds to aversive visceral stimuli in an age-dependent way and this process depends on the vagal afferent pathways.

Neuroprotective Effect of Intravitreal Single-Dose Lithium Chloride after Optic Nerve Injury in Rats.

OBJECTIVE: Lithium is an old drug to control bipolar disorder. Moreover, it presents neuroprotective effects and supports neuronal plasticity. The aim of this study was to evaluate neuroprotective effect of intravitreal lithium after optic nerve injury. METHODS: Three dosages of lithium chloride, including 2 pmol, 200 pmol, and 2 nmol, were injected intravitreally after rat optic nerve injury. Proteins expression were assessed by western blot. Nitric oxide (NO) metabolites were measured by Griess test. Visual evoked potential (VEP) and optical coherence tomography (OCT) measurement were performed after trauma induction, in addition to H & E and TUJ1 staining of ganglion cells. RESULTS: Western blot depicted lithium can significantly increase antiapoptotic Bcl-2 protein level and reduce p-ERK, Toll-like receptor 4 (TLR4) and proapoptotic proteins such as Bax level in retinal tissue and Griess test reflected that NO metabolites level decreased in lithium treated eyes (P < .05). While, OCT showed no significant changes (P = .36 and P = .43 comparing treated group with trauma) in retinal ganglion cell layer thickness after lithium injection, VEP P2 wave amplitude increased significantly (P < .01) in lithium-treated eyes and its latency reduced (P < .05 for N1 wave and P < .01 for P2 wave). Tuj1 antibody-labeled retinal ganglion cells analyzing showed that the number of retinal ganglion cells were significantly higher in lithium treated eyes compared to untreated eyes with optic nerve injury. CONCLUSION: It seems intravitreally lithium has optic nerve neuroprotective effects by various mechanisms like overexpression of antiapoptotic proteins, suppressing proinflammatory molecules and proapoptotic factors, and decreasing nitric oxide.

Lithium chloride functions as Newcastle disease virus-induced ER-stress modulator and confers anti-viral effect.

Newcastle disease is a severe clinical manifestation of avian species caused by Newcastle disease virus (NDV). Although several vaccination strategies are available to protect poultry against NDV infection, even then, outbreaks have been reported in the vaccinated birds. The lack of therapeutics against NDV makes the need for effective anti-viral drugs is of utmost importance. Lithium Chloride (LiCl) is a widely prescribed drug for the treatment of bipolar disorder, acute brain injuries, and chronic neurodegenerative diseases. Also, LiCl has been repurposed as an effective anti-viral drug for some viral infections. In the present work, we have investigated the efficacy of LiCl to inhibit NDV replication using in vitro, in ovo, and in vivo models. Our results collectively showed the modulation of NDV replication after the LiCl treatment. We also demonstrated that NDV induces endoplasmic reticulum stress (ER-stress), and a stress-inducible ER chaperone, glucose-regulating protein 78 (GRP78), was found to be over-expressed after NDV infection. Subsequently, the treatment of NDV infected cells with LiCl significantly reduced the transcript and protein levels of GRP78. Finally, we concluded that LiCl treatment protects the cells from ER-stress induced by the NDV infection.

Interoceptive insular cortex participates in sensory processing of gastrointestinal malaise and associated behaviors.

The insular cortex plays a central role in the perception and regulation of bodily needs and emotions. Its modular arrangement, corresponding with different sensory modalities, denotes a complex organization, and reveals it to be a hub that is able to coordinate autonomic and behavioral responses to many types of stimuli. Yet, little is known about the dynamics of its electrical activity at the neuronal level. We recorded single neurons in behaving rats from the posterior insula cortex (pIC), a subdivision considered as a primary interoceptive cortex, during gastrointestinal (GI) malaise, a state akin to the emotion of disgust in humans. We found that a large proportion of pIC neurons were modulated during the rodent compensatory behaviors of lying on belly (LOB) and Pica. Furthermore, we demonstrated that LOB was correlated with low-frequency oscillations in the field potentials and spikes at the theta (8 Hz) band, and that low-frequency electrical microstimulation of pIC elicited LOB and Pica. These findings demonstrate that pIC neurons play a critical role in GI malaise perception, and that the pIC influences the expression of behaviors that alleviate GI malaise. Our model provides an accessible approach at the single cell level to study innate emotional behaviors, currently elusive in humans.

Protein kinase C isoforms as a target for manic-like behaviors and oxidative stress in a dopaminergic animal model of mania.

Bipolar disorder (BD) is a chronic condition characterized by severe mood swings alternating between episodes of mania and depression. Evidence indicates that protein kinase C (PKC) and oxidative stress are important therapeutic targets for BD. However, what PKC isoforms that are precisely involved in this effect are unknown. Therefore, we evaluated the effects of the intracerebroventricular (ICV) injection of PKC inhibitors (lithium (Li), tamoxifen (TMX), PKCα inhibitor (iPKCα), PKCγ inhibitor (iPKCγ), and PKCε inhibitor (iPKCε)) on the manic-like behaviors and oxidative stress parameters (4-hydroxy-2-nonenal (4-HNE), 8-isoprostane (8-ISO), carbonyl groups, 3-nitrotyrosine (3-NT), glutathione peroxidase (GPx) and glutathione reductase (GR)) in the brains of rats submitted to the model of mania induced by methamphetamine (m-AMPH). Animals received a single ICV infusion of artificial cerebrospinal fluid, Li, TMX, iPKCα, iPKCγ or iPKCε followed by an intraperitoneal injection of saline or m-AMPH before the behavioral analysis (open-field task). Oxidative stress was evaluated in the striatum, frontal cortex, and hippocampus. ICV injection of Li, TMX or iPKCε blocked the m-AMPH-induced increase in the manic-like behaviors - crossings, rearings, visits to the center, sniffing, and grooming. ICV infusion of iPKCα triggered a decrease in these behaviors induced by m-AMPH. Besides, the iPKCε administration significantly prevented the oxidative damage to lipids and proteins, as well as disturbances in the activity of antioxidant enzymes induced by m-AMPH. The findings of the present study suggest that PKCε isoform is strongly implied in the antimanic and antioxidant effects of Li, TMX, and the other PKC inhibitors in the model of mania.

Differential effects of lithium isotopes in a ketamine-induced hyperactivity model of mania.

Sub-anesthetic doses of ketamine produce an increase in rodent ambulation that is attenuated by co-administration of naturally-occurring lithium (LiN), the drug most commonly employed in the treatment of bipolar illness. As a consequence, ketamine-induced hyperactivity has been proposed as an animal model of manic behavior. The current study employed a modified version of this model to compare the potency of LiN to that of each of its two stable isotopes - lithium-6 (Li-6) and lithium-7 (Li-7). Since Li-7 constitutes 92.4% of the parent compound it was hypothesized to produce comparable behavioral effects to that of LiN. The current study was devised to determine whether Li-6 might be more, less, or equally effective at tempering hyperactivity relative to Li-7 or to LiN in an animal model of manic behavior. Male rats were maintained on a restricted but high-incentive diet containing a daily dose of 2.0 mEq/kg of lithium (LiN), Li-6 or Li-7 for 30 days. A control group consumed a diet infused with sodium chloride (NaCl) in place of lithium to control for the salty taste of the food. On day 30, baseline testing revealed no differences in the locomotor behavior among the four treatment groups. Animals then continued their Li/NaCl diets for an additional 11 days during which every subject received a single IP injection of either ketamine (25 mg/kg) or 0.9% physiological saline. On the final four days of this regimen, locomotor activity was assessed during 60 min sessions each beginning immediately after ketamine injection. While all three lithium groups produced comparable decreases in ketamine-induced hyperactivity on the first trial, by the fourth trial Li-6 animals exhibited significantly greater and more prolonged reductions in hyperactivity compared to either Li-7 and Li. These results suggest that Li-6 may be more effective at treating mania than its parent compound.

Glycyrrhizic acid renders robust neuroprotection in rodent model of vascular dementia by controlling oxidative stress and curtailing cytochrome-c release.

Background: Chronic cerebral hypoperfusion (CCH), a concern for neurocognitive health, is linked to various vascular ailments and other comorbidities. This study primarily aims to explain the mitigating effects of glycyrrhizic acid (GA) on cognitive health challenged by chronic cerebral hypoperfusion. Methods: Adult male Sprague Dawley rats were allocated into four groups: (i) Sham, (ii) Lesion (2VO), (iii) GA treated (20 mg/kg), and (iv) lithium chloride (Li) treated (40 mg/kg). On 30th postoperative day the rats were tested for cognitive behaviour through a repertoire of tests. Rats were transcardially perfused and the brain samples were obtained for histological assessments. For biochemical assessments, hippocampus isolated from fresh brain was utilized. Results: The antioxidant propensity of GA curtailed ROS generation by restoring mitochondrial complex I and IV, enzymatic and non-enzymatic antioxidant activity. However, Li group exhibited significantly reduced antioxidant defence, when compared with GA. The strong antioxidant defence had caused considerable restoration of pyramidal neurons, myelin and dendritic spine density in GA treated than Li treated. GA treated rats showed a remarkable amelioration of cognitive deficits when compared with lesion rats. Finally, GA also reduced the cytochrome-c release, thus creating a blockade for further succession of apoptotic events. Conclusion: The outcome of this study clearly implies that GA shows promising neuroprotection in CCH-induced rats by enhancing the endogenous antioxidants and curtails the apoptosis by reducing cytochrome-c release. GA was also found to be much better than Li through modulation of GSK3ß/Nrf2 pathway, in turn, mitigates the adverse consequences of CCH.

Lithium chloride reduced the level of oxidative stress in brains and serums of APP/PS1 double transgenic mice via the regulation of GSK3ß/Nrf2/HO-1 pathway.

Aim: The aim of this study is to investigate whether lithium chloride (LiCl) can regulate glycogen synthase kinase-3ß (GSK3ß)/nuclear factor E2 related factor（Nrf2）/heme oxygenase-1 (HO-1) pathway to reduce the injury of oxidative stress in APP/PS1 double transgenic mice.Materials and Methods: The APP/PS1 double transgenic and wild-type (WT) mice were divided randomly into four groups, i.e. WT, WT + LiCl (LiCl 100 mg/kg by gavage once daily), the transgenic + LiCl and the transgenic groups. The expressions of phosphor-GSK3ß (ser9), Nrf2 and HO-1 at protein levels were detected by Western blotting. The activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and the content of malondialdehyde (MDA) were measured by related detection kits. Nissl bodies in different brain regions were examined by Nissl staining.Results: The decreased protein levels of phosphor-GSK3ß (ser9), Nrf2 and HO-1, the declined activities of SOD and GSH-Px, the increased content of MDA and the decreased Nissl bodies in neurons were observed in the brains or serums of APP/PS1 mice as compared with WT. The treatment with LiCl attenuated these changes in the levels of GSK3ß/Nrf2/HO-1 pathway and oxidative stress as well as Nissl bodies induced by APP/PS1 mutation.Conclusion: LiCl reversed the declined activities of SOD and GSH-Px and the increased content of MDA as well as the decreased Nissl bodies in neurons in the brains or serums of APP/PS1 mice, the mechanism of which may be involved in the down-regulation of the activity of GSK3ß and consequently enhances the expressions of Nrf2 and HO-1.

A Low-Therapeutic Dose of Lithium Inhibits GSK3 and Enhances Myoblast Fusion in C2C12 Cells.

Glycogen synthase kinase 3 (GSK3) slows myogenic differentiation and myoblast fusion partly by inhibiting the Wnt/ß-catenin signaling pathway. Lithium, a common medication for bipolar disorder, inhibits GSK3 via Mg+ competition and increased Ser21 (GSK3α) or Ser9 (GSK3ß) phosphorylation, leading to enhanced myoblast fusion and myogenic differentiation. However, previous studies demonstrating the effect of lithium on GSK3 have used concentrations up to 10 mM, which greatly exceeds concentrations measured in the serum of patients being treated for bipolar disorder (0.5-1.2 mM). Here, we determined whether a low-therapeutic (0.5 mM) dose of lithium could promote myoblast fusion and myogenic differentiation in C2C12 cells. C2C12 myotubes differentiated for three days in media containing 0.5 mM lithium chloride (LiCl) had significantly higher GSK3ß (ser9) and GSK3α (ser21) phosphorylation compared with control myotubes differentiated in the same media without LiCl (+2-2.5 fold, p < 0.05), a result associated with an increase in total ß-catenin. To further demonstrate that 0.5 mM LiCl inhibited GSK3 activity, we also developed a novel GSK3-specific activity assay. Using this enzyme-linked spectrophotometric assay, we showed that 0.5 mM LiCl-treated myotubes had significantly reduced GSK3 activity (-86%, p < 0.001). Correspondingly, 0.5 mM LiCl treated myotubes had a higher myoblast fusion index compared with control (p < 0.001) and significantly higher levels of markers of myogenesis (myogenin, +3-fold, p < 0.001) and myogenic differentiation (myosin heavy chain, +10-fold, p < 0.001). These results indicate that a low-therapeutic dose of LiCl is sufficient to promote myoblast fusion and myogenic differentiation in muscle cells, which has implications for the treatment of several myopathic conditions.

Combined low-dose LiCl and LY294002 for the treatment of osteoporosis in ovariectomized rats.

BACKGROUND: To provide a low-toxicity and high-efficacy clinical treatment for osteoporosis via a novel combination of LiCl and LY294002. METHODS: The protein levels of p-AKT, AKT, p-GSK3ß, GSK3ß, ß-catenin, p-ß-catenin, and NFATC1 were measured in osteoblasts and osteoclasts by Western blot. ALP activity and TRACP activity were measured using the corresponding kit. The levels of BALP, PINP, CTX, and TRACP-5b were determined in accordance with the requirements of the ELISA kits. Microstructural analysis was performed on the left distal femur using microcomputed tomography. RESULTS: Treatment with the combination of LiCl and LY294002 led to a markedly increased osteoblast activity but significantly decreased osteoclast differentiation and bone absorption capacity compared with the treatment with LiCl or LY294002 alone (P < 0.01). In serum, the low-dose combination of LiCl and LY294002 significantly enhanced BALP levels (P < 0.01) and significantly decreased PINP, TRACP-5b, and CTX levels (P < 0.01) compared with the application of either drug alone. CONCLUSIONS: This study indicates that drug combinations directed at multiple targets could be used for osteoporosis treatment by promoting osteoblast proliferation and inhibiting differentiation with high efficiency.

Pore-former enabled seeding of tau in rats: Alleviation by memantine and lithium chloride.

Background Tauopathies, including Alzheimer's disease (AD), are multifactorial diseases with strong phenotypic and genetic heterogeneity. Recent evidence revealed that mechanisms of pathogenesis of early (hereditary) and late (sporadic) forms of AD are different. This is not properly reflected in current experimental models, especially when it comes to sporadic forms of AD. Here, we present novel seeding based model and explore its suitability for therapeutic intervention. New method We validate novel region specific approach to modelling Tau pathology reported by Koss and co-authors (2015). Wistar rats 3, 9 and 15 month-old were surgically prepared for hippocampal loading with pore-former polymeric 1,3-alkylpyridinium salts (Poly-APS) and recombinant human tau including pharmacological inhibition of phosphatase activity by okadaic acid co-administration. We explored whether tau seeding caused molecular and behavioural traits reminiscent of AD and explored their reversibility/prevention by administration of either memantine or lithium. Results The presented model emulates several changes observed in progressive dementia such as: heightened levels of tau and its hyperphosphorylation, changes in tau compartmentalization, breakdown of the cytoskeleton, cognitive impairments, and sensitivity for anti-dementia treatment. Comparison with existing methods Seeding has been achieved in transgenic mouse models, but this is the first rat model significantly mimicking cognitive and neuronal changes akin to tauopathies. Moreover, we have successfully included the factor age in our model and can show sensitivity to drug treatment. Conclusions These data validate a novel model of locally infused recombinant human Tau as an inducer of tauopathy in rats and holds the potential for development of novel therapies.

SLC1A2 mediates refractory temporal lobe epilepsy with an initial precipitating injury by targeting the glutamatergic synapse pathway.

This study aimed to identify the genes related to epilepsy and their effects on epilepsy, as well as the underlying mechanism. Using microarray analysis, differentially expressed genes (DEGs) were screened out and then used to build weighted gene coexpression networks using WGCNA. Module membership and evaluation of gene significance (GS) were adopted to detect hub genes. The DAVID online tool was used to understand the function of modules and target genes. The Licl-pilocarpine chronic rat epilepsy model was used to simulate mesial temporal lobe epilepsy with an initial precipitating injury. Hippocampal expression of the proteins solute carrier family 1 member 2 (SLC1A2), glial fibrillary acidic protein, interleukin-1ß (IL-1ß), tumor necrosis factor α (TNF-α), and N-methyl-d-aspartic acid receptor (NMDAR) was determined by ELISA and Western blot. Nissl staining was used to measure neuronal loss. Immunohistochemistry was performed to assess the percentage of positive cells to reflect the distribution of NMDAR1. Here, 3232 potential genes highly correlated with epilepsy were selected from the screened DEGs, among which SLC1A2 was related to brain development and its expression was significantly decreased in epilepsy patients. According to Gene Ontology and KEGG analysis, SLC1A2 mediates epilepsy through the glutamatergic synapse pathway. Tissue experiments suggested that Slc1a2 could genuinely ameliorate epilepsy through the glutamatergic synapse pathway, mitigate neuronal loss, and suppress astrocytosis and inflammatory responses. Our study suggested that low hippocampal content of SLC1A2 is a potential biomarker of epilepsy and may affect the function of neurons through the glutamatergic synapse pathway. © 2018 IUBMB Life, 71(1):213-222, 2019.

Rifampicin ameliorates lithium-pilocarpine-induced seizures, consequent hippocampal damage and memory deficit in rats: Impact on oxidative, inflammatory and apoptotic machineries.

Epilepsy is one of the serious neurological sequelae of bacterial meningitis. Rifampicin, the well-known broad spectrum antibiotic, is clinically used for chemoprophylaxis of meningitis. Besides its antibiotic effects, rifampicin has been proven to be an effective neuroprotective candidate in various experimental models of neurological diseases. In addition, rifampicin was found to have promising antioxidant, anti-inflammatory and anti-apoptotic effects. Herein, we investigated the anticonvulsant effect of rifampicin at experimental meningitis dose (20 mg/kg, i.p.) using lithium-pilocarpine model of status epilepticus (SE) in rats. Additionally, we studied the effect of rifampicin on seizure induced histopathological, neurochemical and behavioral abnormalities. Our study showed that rifampicin pretreatment attenuated seizure activity and the resulting hippocampal insults marked by hematoxylin and eosin. Markers of oxidative stress, neuroinflammation and apoptosis were evaluated, in the hippocampus, 24 h after SE induction. We found that rifampicin pretreatment suppressed oxidative stress as indicated by normalized malondialdehyde and glutathione levels. Rifampicin pretreatment attenuated SE-induced neuroinflammation and decreased the hippocampal expression of interleukin-1ß, tumor necrosis factor-α, nuclear factor kappa-B, and cyclooxygenase-2. Moreover, rifampicin mitigated SE-induced neuronal apoptosis as indicated by fewer positive cytochrome c immunostained cells and lower caspase-3 activity in the hippocampus. Furthermore, Morris water maze testing at 7 days after SE induction showed that rifampicin pretreatment can improve cognitive dysfunction. Therefore, rifampicin, currently used in the management of meningitis, has a potential additional advantage of ameliorating its epileptic sequelae.