Combined Epigenetic Drugs Elicit Neuroprotective Effects on Sex Dimorphic Features in ALS Mice

Amyotrophic lateral sclerosis (ALS) is a fatal adult-onset neurodegenerative disorder. There is no cure and current treatments fail to slow the progression of the disease. Epigenetic modulation in the acetylation state of NF-kB RelA and the histone 3 (H3) protein, involved in the development of neurodegeneration, is a drugable target for the class-I histone deacetylases (HDAC) inhibitors, entinostat or valproate, and the AMP-activated kinase (AMPK)-sirtuin 1 pathway activator, resveratrol. In this study, we demonstrated that the combination of valproate and resveratrol can restore the normal acetylation state of RelA in the SOD1(G93A) murine model of ALS, in order to obtain the neuroprotective form of NF-kB. We also investigated the sexually dimorphic development of the disease, as well as the sex-sensibility to the treatment administered. We showed that the combined drugs, which rescued AMPK activation, RelA and the histone 3 acetylation state, reduced the motor deficit and the disease pathology associated with motor neuron loss and microglial reactivity, Brain-Derived Neurotrophic Factor (BDNF) and B-cell lymphoma-extra large (Bcl-xL) level decline. Specifically, vehicle-administered males showed earlier onset and slower progression of the disease when compared to females. The treatment, administered at 50 days of life, postponed the time of onset in the male by 22 days, but not in a significant way in females. Nevertheless, in females, the drugs significantly reduced symptom severity of the later phase of the disease and prolonged the mice’s survival. Only minor beneficial effects were produced in the latter stage in males. Overall, this study shows a beneficial and sexually dimorphic response to valproate and resveratrol treatment in ALS mice

Defect in Synaptic Pruning of Motor Cortex Neurons is Associated with Early Perturbed Dopaminergic System

Background: Early stress exposure during neurodevelopmental stages has been linked to some adult neuropsychiatric disorders. The dopaminergic system which has been implicated in movement and reward system has been linked to movement and mood disorders when perturbed at early development. This study is designed to check the mechanisms involved in movement disorders such as dyskinesia, associated with early perturbed dopaminergic system in the motor cortex. Methods:Haloperidol was used to block D2R in neonatal albino Wistar rats in utero by administering 20 mg/kg BW (intraperitoneally) to pregnant adult wistar rats (n=8) in the third week of gestation. Behavioural studies such as the rotarod test were carried out on the neonatal animals (n=5) to test their motor function at postnatal day twentyeight (P28). Electrophysiological recordings were carried out on the motor cortex (M1) to determine the significance of D2R inhibition on calcium neural activity. Immunofluorescence was done to demonstrate synaptic vesicle protein (SV) and microtubule associated protein kinases (MAP K) as a measure of synapses count and microtubule phosphorylation respectively. Results: Behavioural studies showed a decline in motor function of animals exposed to haloperidol in utero compared to the control. This motor deficit was accompanied by a significant increase in the Ca 2+ neural activity of the motor cortex as shown by electrophysiological recordings. Immunofluorescence staining showed there was significant increase in the number of MAPK+ and SV+ cells in the motor cortex of haloperidol exposed animals compared to the control. Conclusion: These findings showed that early perturbation in dopaminergic system is associated with an increase in synapses and neuronal density, as well as an increase in phosphorylation of microtubules of neurons in the motor cortex

Beneficial and sexually dimorphic response to combined HDAC inhibitor valproate and AMPK/SIRT1 pathway activator resveratrol in the treatment of ALS mice

Amyotrophic lateral sclerosis (ALS) is a fatal adult-onset neurodegenerative disorder. There is no cure and current treatments fail to slow the progression of the disease. Epigenetic modulation in the acetylation state of NF-kB RelA and the histone 3 (H3) protein, involved in the development of neurodegeneration, is a drugable target for the class-I histone deacetylases (HDAC) inhibitors, entinostat or valproate, and the AMP-activated kinase (AMPK)-sirtuin 1 pathway activator, resveratrol. In this study, we demonstrated that the combination of valproate and resveratrol can restore the normal acetylation state of RelA in the SOD1(G93A) murine model of ALS, in order to obtain the neuroprotective form of NF-kB. We also investigated the sexually dimorphic development of the disease, as well as the sex-sensibility to the treatment administered. We showed that the combined drugs, which rescued AMPK activation, RelA and the histone 3 acetylation state, reduced the motor deficit and the disease pathology associated with motor neuron loss and microglial reactivity, Brain-Derived Neurotrophic Factor (BDNF) and B-cell lymphoma-extra large (Bcl-xL) level decline. Specifically, vehicle-administered males showed earlier onset and slower progression of the disease when compared to females. The treatment, administered at 50 days of life, postponed the time of onset in the male by 22 days, but not in a significant way in females. Nevertheless, in females, the drugs significantly reduced symptom severity of the later phase of the disease and prolonged the mice's survival. Only minor beneficial effects were produced in the latter stage in males. Overall, this study shows a beneficial and sexually dimorphic response to valproate and resveratrol treatment in ALS mice

Synergistic association of resveratrol and histone deacetylase inhibitors as treatment in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease associated with motor neuron degeneration, progressive paralysis and finally death. Despite the research efforts, currently there is no cure for ALS. In recent years, multiple epigenetic mechanisms have been associated with neurodegenerative diseases. A pathological role for histone hypoacetylation and the abnormal NF-κB/RelA activation involving deacetylation of lysines, with the exclusion of lysine 310, has been established in ALS. Recent findings indicate that the pathological acetylation state of NF-κB/RelA and histone 3 (H3) occurring in the SOD1(G93A) murine model of ALS can be corrected by the synergistic combination of low doses of the AMP-activated kinase (AMPK)-sirtuin 1 pathway activator resveratrol and the histone deacetylase (HDAC) inhibitors MS-275 (entinostat) or valproate. The combination of the epigenetic drugs, by rescuing RelA and the H3 acetylation state, promotes a beneficial and sexually dimorphic effect on disease onset, survival and motor neurons degeneration. In this mini review, we discuss the potential of the epigenetic combination of resveratrol with HDAC inhibitors in the ALS treatment

Inhibition of Dopamine Receptor in Neonate Hippocampus: Immunolocalization of Post Synaptic Density Protein-95 and Dopamine Receptor in vivo

The effect of haloperidol on neonatal dopaminergic neurotransmission in the hippocampus of postnatal day 20 rats (P.20) was investigated in this study. Haloperidol blocked dopamine receptors (D2R) and inhibited D2R on the membrane of neonate neurons. For this study the 0.5 ml (20 mg/kg) of haloperidol was administered to pregnant female animals intraperitoneally a week before delivery. At day P.20, 5 control animals and 5 haloperidol treated animals were taken to the behavioral studies room for the Y maze and Novel object recognition test, which was done 7 am in the morning before mating. Electrophysiology was done with 2 control pups and 2 treated pups. Electrodes were implanted in the brain at the hippocampal region 2 mm beneath the bregma, 2 mm lateral to the midline. Anterior Posterior (AP=0), Medial Lateral (ML=2 mm). Also immunolocalization and immunofluorescence of post synaptic density protein (PSD-95), hippocampal morphology and hippocampal neurons have been done respectively. Results from this study showed a decline in memory index for the Y maze as a result of the effect of D2R blockade thereby inhibiting neurotransmission in newborns. Electrophysiology result in this study showed an increase in the root mean square (RMS) of control pups. The increase in RMS is equivalent to increase in wave burst pattern caused by neuronal excitation. Immunochemistry result showed an increase in the number of PSD-95 in the hippocampus of an increase in tyrosine hydroxylase in the hippocampus of the treated neonatal rats when compared to the control neonatal rats Immunofluorescence showed decline in the number of neurons in the haloperidol treated rats and it also caused hippocampal damage in terms of morphology. Furthermore, results from electrophysiology showed a statistical significant difference with P value 0.04229 (P<0.05) using the student t-test. These findings suggest that D2R inhibition may cause decline in memory function, impair learning in newborns and disrupt neonatal dopaminergic neurotransmissio

Neural and behavioural changes in male periadolescent mice after prolonged nicotine-MDMA treatment

The interaction between MDMA and Nicotine affects multiple brain centres and neurotransmitter systems (serotonin, dopamine and glutamate) involved in motor coordination and cognition. In this study, we have elucidated the effect of prolonged (10 days) MDMA, Nicotine and a combined Nicotine-MDMA treatment on motor-cognitive neural functions. In addition, we have shown the correlation between the observed behavioural change and neural structural changes induced by these treatments in BALB/c mice.We observed that MDMA (2 mg/Kg body weight; subcutaneous) induced a decline in motor function, while Nicotine (2 mg/Kg body weight; subcutaneous) improved motor function in male periadolescent mice. In combined treatment, Nicotine reduced the motor function decline observed in MDMA treatment, thus no significant change in motor function for the combined treatment versus the control. Nicotine or MDMA treatment reduced memory function and altered hippocampal structure. Similarly, a combined Nicotine-MDMA treatment reduced memory function when compared with the control. Ultimately, the metabolic and structural changes in these neural systems were seen to vary for the various forms of treatment. It is noteworthy to mention that a combined treatment increased the rate of lipid peroxidation in brain tissue

Vitamin D 3 Receptor Activation Rescued Corticostriatal Neural Activity and Improved Motor Function in –D 2 R Tardive Dyskinesia Mice Model

Haloperidol-induced dyskinesia has been linked to a reduction in dopamine activity characterized by the inhibition of dopamine receptive sites on D2-receptor (D2R). As a result of D2R inhibition, calcium-linked neural activity is affected and seen as a decline in motor-cognitive function after prolonged haloperidol use in the treatment of psychotic disorders. In this study, we have elucidated the relationship between haloperidol-induced tardive dyskinesia and the neural activity in motor cortex (M1), basal nucleus (CPu), prefrontal cortex (PFC) and hippocampus (CA1). Also, we explored the role of Vitamin D3 receptor (VD3R) activation as a therapeutic target in improving motor-cognitive functions in dyskinetic mice. Dyskinesia was induced in adult BALB/c mice after 28 days of haloperidol treatment (10 mg/Kg; intraperitoneal). We established the presence of abnormal involuntary movements (AIMs) in the haloperidol treated mice (−D2) through assessment of the threshold and amplitude of abnormal involuntary movements (AIMs) for the Limbs (Li) and Orolingual (Ol) area (Li and Ol AIMs). As a confirmatory test, the dyskinetic mice (−D2) showed high global AIMs score when compared with the VD3RA intervention group (−D2/+VDR) for Li and Ol AIMs. Furthermore, in the behavioral tests, the dyskinetic mice exhibited a decrease in latency of fall (LOF; Rotarod-P < 0.05), climbing attempts (Cylinder test; P < 0.05) and latency of Turning (Parallel bar test; LOT-P < 0.05) when compared with the control. The reduced motor function in dyskinetic mice was associated with a decline in CPu-CA1 burst frequencies and an increase in M1-PFC cortical activity. However, after VD3RA intervention (−D2/+VDR), 100 mg/Kg for 7 days, CPu-CA1 burst activity was restored leading to a decrease in abnormal movement, and an increase in motor function. Ultimately, we deduced that VD3RA activation reduced the threshold of abnormal movement in haloperidol induced dyskinesia

Kolaviron was protective against sodium azide (NaN 3 )induced oxidative stress in the prefrontal cortex

Kolaviron is a phytochemical isolated from Garcina kola (G. kola); a common oral masticatory agent in Nigeria (West Africa). It is a bioflavonoid used - as an antivi- ral, anti-inflammatory and antioxidant - in relieving the symp- toms of several diseases and infections. In this study we have evaluated the neuroprotective and regenerative effect of kolaviron in neurons of the prefrontal cortex (Pfc) before or after exposure to sodium azide (NaN 3 ) induced oxidative stress. Separate groups of animals were treated as follows; kolaviron (200 mg/Kg) for 21 days; kolaviron (200 mg/Kg for21days)followedbyNaN 3 treatment (20 mg/Kg for 5days);NaN 3 treatment (20 mg/Kg for 5 days) followed by kolaviron (200 mg/Kg for 21 days); 1 ml of corn-oil (21 days- vehicle); NaN 3 treatment (20 mg/Kg for 5 days). Exploratory activity associated with Pfc function was assessed in the open field test (OFT) following which the microscopic anatomy of the prefrontal cortex was examined in histology (Haematoxylin and Eosin) and antigen retrieval Immunohis- tochemistry to show astroglia activation (GFAP), neuronal metabolism (NSE), cytoskeleton (NF) and cell cycle dysreg- ulation (p53). Subsequently, we quantified the level of Glucose-6-phosphate dehydrogenase (G6PDH) and lactate dehydrogenase (LDH) in the brain tissue homogenate as a measure of stress-related glucose metabolism. Kolaviron (Kv) and Kolaviron/NaN 3 treatment caused no prominent change in astroglia density and size while NaN 3 and NaN 3 / Kv induced astroglia activation and scar formation (astrogliosis) in the Pfc when compared with the control. Sim- ilarly, Kolaviron and Kv/NaN 3 did not alter NSE expression (glucose metabolism) while NaN 3 and NaN 3 /Kv treatment increased cortical NSE expression; thus indicating stress related metabolism. Further studies on enzymes of glu- cose metabolism (G6PDH and LDH) showed that NaN 3 increased LDH while kolaviron reduced LDH in the brain tissue homogenate (P<0.001). In addition kolaviron treatment before (P<0.001) or after ( P <0.05) NaN 3 treatment also reduced LDH expression; thus supporting its role in suppression of oxidative stress. Interestingly, NF deposition increased in the Pfc after kolaviron treatment while Kv/NaN 3 showed no sig- nificant change in NF when compared with the control. In furtherance, NaN 3 and NaN 3 /Kv caused a decrease in NF deposition (degeneration). Ultimately, the protective effect of KV administered prior to NaN 3 treatment was confirmed through p53 expression; which was similar to the control. However, NaN 3 and NaN 3 /Kv caused an increase in p53 expression in the Pfc neurons (cell cycle dysregulation). We conclude that kolaviron is not neu- rotoxic when used at 200 mg/Kg BW. Furthermore, 200 mg/Kg of kolaviron administered prior to NaN 3 treatment (Kv/NaN 3 ) was neuroprotective when com- pared with Kolaviron administered after NaN 3 treatment (NaN 3 /Kv). Some of the observed effects of kolaviron administered before NaN 3 treatment includes reduction of astroglia activation, absence of astroglia scars, anti- oxidation (reduced NSE and LDH), prevention of neu- rofilament loss and cell cycle regulatio

Vitamin D3 Receptor Activation Rescued Corticostriatal Neural Activity and Improved Motor-Cognitive Function in −D2R Parkinsonian Mice Model

Background: fourth generation antipsychotics have been implicated in the blockade of calcium signalling through inhibition of dopamine receptive sites on dopaminergic D2 Receptor (D2R). As a result of the abnormal calcium signalling associated with D2R inhibition, changes occur in the motor and memory neural axis leading to the observed behavioural deficits after prolonged haloperidol. Thus, Vitamin D3 receptor (VD3R), a calcium controlling receptor in the striatum can be targeted to relief the neurological symptoms associated with haloperidol (−D2R) induced PD. Aim: This study sets to investigate the role of VD3R activation in vitro and in vivo after haloperidolinduced Dopaminergic (D2R) blockade. In addition, we examined the associated neural activity and behavioural changes in parkinsonian and VDRA intervention mice. Methods: Dopaminergic D2R inhibition was investigated in vitro using Melanocytes isolated from the scale of a Tilapia. In four separate set ups, the cells were cultured in calcium free Ringer’s solution as follows; 300 μM haloperidol, 100 μM VD3, 100 mM calcium chloride and a combination of 300 μM haloperidol and 100 μM VD3. Subsequently, dopaminergic vesicle accumulation and calcium signalling were observed in bright field microscopy using blue and green fluorescence probes. In the second phase, PD was induced in adult BALB/c mice (−D2; n = 8) after 14 days of intraperitoneal haloperidol treatment (10 mg/Kg). A set of n = 4 mice were untreated (−D2) while the other group (n = 4) received 100 mg/Kg of VD3 for 7 days (−D2/+VDR). The control groups (n = 4 each) were treated with normal saline (NS) and VD3 (+VDR) for 14 days. At the end of the treatment phase, the animals were assessed in Rotarod, parallel bar-, cylinder-, Y-Maze-, one trial place recognition- and novel object recognition-(NOR) tests. Neural activity was measured using chronic electrode implants placed in the M1 (motor cortex), CPu (striatum), CA1 (hippocampus) and PFC (prefrontal cortex). Neural activity was compared with the outcomes of behavioural tests for memory and motor functions and data was expressed as mean ± SEM (analysed using ANOVA with Tukey post-hoc test, significant level was set at 0.05). Results/Discussion: in vitro outcomes show that VDR increase calcium signalling and reverses the effect of haloperidol; specifically by reducing dopaminergic vesicle accumulation in the cell body. Similarly, in vivo neural recordings suggest an increase in calcium hyperpolarization currents in the CPu and PFC of intervention mice (−D2/+VDR) when compared with the parkinsonian mice (−D2). These animals (−D2/+VDR) also recorded an improvement in spatial working memory and motor function versus the Parkinsonian mice (−D2). These outcomes suggest the role of CPu-PFC corticostriatal outputs in the motor-cognitive decline seen in parkinsonian mice. Similarly, VDRA reduced the neural deficits through restoration of calcium currents (burst activities) in the intervention mice (−D2/+VDR). Conclusion: VDRA treatment reduced the motor-cognitive defects observed in haloperidol induced PD. Our findings suggest the role of VDRA in restoration of calcium currents associated with PFC and CPu corticostriatal outputs seen as burst frequencies in in vivo neural recording

Vitamin D 3 Receptor Activation Rescued Corticostriatal Neural Activity and Improved Motor Function in –D 2 R Tardive Dyskinesia Mice Model

Haloperidol-induced dyskinesia has been linked to a reduction in dopamine activity characterized by the inhibition of dopamine receptive sites on D2-receptor (D2R). As a result of D2R inhibition, calcium-linked neural activity is affected and seen as a decline in motor-cognitive function after prolonged haloperidol use in the treatment of psychotic disorders. In this study, we have elucidated the relationship between haloperidol-induced tardive dyskinesia and the neural activity in motor cortex (M1), basal nucleus (CPu), prefrontal cortex (PFC) and hippocampus (CA1). Also, we explored the role of Vitamin D3 receptor (VD3R) activation as a therapeutic target in improving motor-cognitive functions in dyskinetic mice. Dyskinesia was induced in adult BALB/c mice after 28 days of haloperidol treatment (10 mg/Kg; intraperitoneal). We established the presence of abnormal involuntary movements (AIMs) in the haloperidol treated mice (−D2) through assessment of the threshold and amplitude of abnormal involuntary movements (AIMs) for the Limbs (Li) and Orolingual (Ol) area (Li and Ol AIMs). As a confirmatory test, the dyskinetic mice (−D2) showed high global AIMs score when compared with the VD3RA intervention group (−D2/+VDR) for Li and Ol AIMs. Furthermore, in the behavioral tests, the dyskinetic mice exhibited a decrease in latency of fall (LOF; Rotarod-P < 0.05), climbing attempts (Cylinder test; P < 0.05) and latency of Turning (Parallel bar test; LOT-P < 0.05) when compared with the control. The reduced motor function in dyskinetic mice was associated with a decline in CPu-CA1 burst frequencies and an increase in M1-PFC cortical activity. However, after VD3RA intervention (−D2/+VDR), 100 mg/Kg for 7 days, CPu-CA1 burst activity was restored leading to a decrease in abnormal movement, and an increase in motor function. Ultimately, we deduced that VD3RA activation reduced the threshold of abnormal movement in haloperidol induced dyskinesia