Novel α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptor (AMPAR) potentiator LT-102: A promising therapeutic agent for treating cognitive impairment associated with schizophrenia

AIMS

We aimed to evaluate the potential of a novel selective α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptor (AMPAR) potentiator, LT-102, in treating cognitive impairments associated with schizophrenia (CIAS) and elucidating its mechanism of action.

METHODS

The activity of LT-102 was examined by Ca2+ influx assays and patch-clamp in rat primary hippocampal neurons. The structure of the complex was determined by X-ray crystallography. The selectivity of LT-102 was evaluated by hERG tail current recording and kinase-inhibition assays. The electrophysiological characterization of LT-102 was characterized by patch-clamp recording in mouse hippocampal slices. The expression and phosphorylation levels of proteins were examined by Western blotting. Cognitive function was assessed using the Morris water maze and novel object recognition tests.

RESULTS

LT-102 is a novel and selective AMPAR potentiator with little agonistic effect, which binds to the allosteric site formed by the intradimer interface of AMPAR's GluA2 subunit. Treatment with LT-102 facilitated long-term potentiation in mouse hippocampal slices and reversed cognitive deficits in a phencyclidine-induced mouse model. Additionally, LT-102 treatment increased the protein level of brain-derived neurotrophic factor and the phosphorylation of GluA1 in primary neurons and hippocampal tissues.

CONCLUSION

We conclude that LT-102 ameliorates cognitive impairments in a phencyclidine-induced model of schizophrenia by enhancing synaptic function, which could make it a potential therapeutic candidate for CIAS.

Urinary biomarkers in children with neurogenic and non-neurogenic lower urinary tract dysfunction: A systematic review and meta-analysis

AIM

The aim of this systematic review is to assess urinary biomarkers studied in children with neurogenic and non-neurogenic lower urinary tract dysfunction (LUTD).

MATERIALS AND METHODS

The systematic review was conducted in accordance with the PRISMA guidelines. The screening was performed on PUBMED without any publication date limitation. Only original articles were included. Parameters related to the following topics were obtained: study design, characteristics of participants, number of participants, age, control group, types of biomarkers, measurement technique in urine, subgroup analysis, urodynamic findings, and outcome. Dutch Cochrane Checklist (DCC) and level of evidence by EBRO platform were used for quality assessment. Meta-analysis was performed with the Comprehensive Meta-Analysis Version 4 program.

RESULTS

A total of 494 studies were screened and 16 studies were included. 11 (68.75%) were conducted in children with non-neurogenic LUTD and 5 (31.25%) neurogenic LUTD. Nerve growth factor (NGF) was evaluated in 12 studies, brain-derived neurotrophic factor (BDNF) in 5, Tissue Inhibitor of Metalloproteinase-2 (TIMP-2) in 2, transforming growth factor beta-1 (TGF Beta-1) in 2, neutrophil gelatinase-associated lipocalin (NGAL) in 1, and Aquaporin-2 in 1. According to DCC, 10 (62.5%) articles were evaluated on 4 (37.5%) items and 4 articles on 5 items. The average score was 3.91+/-0.56. The level of evidence was found as B for 13 (81.25%) articles and C for 3 (18.75%). In meta-analysis, urinary NGF levels in children with non-neurogenic LUTS were significantly higher than in the healthy control group (Hedges's g = 1.867, standard error = 0.344, variance = 0.119, p = 0.0001).

CONCLUSION

Urinary biomarkers are promising for the future with their noninvasive features. However, prospective studies with larger sample sizes are needed to better understand the potential of urinary biomarkers to reflect urodynamic and clinical findings in children with LUTD.

An analysis of the relationship of "the Mozart effect" with BDNF levels in anatomy education

In 1993, an increase was observed in the spatial IQ scores of the volunteers who listened to Mozart's sonata K448 for 10 min, and this phenomenon entered the literature as the "Mozart effect." Other studies have shown that this effect is particularly evident in spatial skill tests. A large body of research has provided evidence that spatial ability is associated with success in learning anatomy. In this study, Kastamonu University Faculty of Medicine students were divided into two groups during 16-h practical training spanning 30 days. While one of the groups listened to Mozart's K448 sonata as the background music in all lessons, the control group attended the lessons in their standard form. At the end of each lesson, all students solved a modified mental rotation test including questions involving anatomical structures. Before starting the study, after the first laboratory class, on the 15th and 30th day of the study, blood samples were taken from the participants, and plasma brain-derived neurotrophic factor (BDNF) levels were determined. The effect of time on mental rotation score and plasma BDNF level was significant (p < 0.001 for both). The effect of group was also significant (p < 0.001 for both). Pairwise comparisons showed significance in the fifth, sixth, seventh, and eighth mental rotation test (p < 0.001, p = 0.041, p < 0.001, p < 0.001, respectively) and in the third (Day 15) and fourth (Day 30) BDNF measurement (p < 0.001 for both). Our findings may indicate that specific background music may be useful for anatomy teaching.

Hesperidin reduces depressive symptoms in post-coronary artery bypass graft patients with mild depression

Previous studies have shown that hesperidin may have beneficial effects on depression; however, to the best of our knowledge, no clinical trial has yet been conducted in this area. The aim of the present study was, therefore, to determine the effects of hesperidin on depression, serum brain-derived neurotrophic factor (BDNF), and serum cortisol levels in post-coronary artery bypass graft (CABG) patients. Toward this goal, 73 post-CABG patients with depression symptoms were enrolled. The participants were randomly divided into two groups to receive either 200 mg/day hesperidin (n = 38) or placebo (n = 35) for 12 weeks. Depressive symptoms, serum BDNF, and cortisol levels were then assessed at the baseline and after intervention. Beck Depression Inventory-II (BDI-II) was also used to determine the severity of depression. Sixty-six patients completed the trial. Hesperidin decreased depression severity after 12 weeks, as compared to placebo (p = .004), but serum BDNF and cortisol were not statistically significantly different in the two groups after the intervention. Subgroup analyses also showed that, while in the patients with mild depression, the score of BDI-II was significantly different in the hesperidin and placebo groups after intervention; there was no difference in the severity of depression between the two groups in patients with moderate-to-severe depression. To conclude, a dose of 200 mg/day hesperidin may reduce depressive symptoms after 12 weeks in post-CABG patients with mild depression.

Virtual reality cognitive intervention for heart failure: CORE study protocol

Introduction

Heart failure (HF) is a prevalent, serious chronic illness that affects 6.5 million adults in the United States. Among patients with HF, the prevalence of attention impairment is reported to range from 15% to 27%. Although attention is fundamental to human activities including HF self-care, cognitive interventions for patients with HF that target improvement in attention are scarce. The COgnitive intervention to Restore attention using nature Environment (CORE) study aims to test the preliminary efficacy of the newly developed Nature-VR, a virtual reality-based cognitive intervention that is based on the restorative effects of nature. Nature-VR development was guided by Attention Restoration Theory. The target outcomes are attention, HF self-care, and health-related quality of life (HRQoL). Our exploratory aims examine the associations between attention and several putative/established HF biomarkers (eg, oxygen saturation, brain-derived neurotrophic factor, apolipoprotein E, dopamine receptor, and dopamine transporter genes) as well as the effect of Nature-VR on cognitive performance in other domains (ie, global cognition, memory, visuospatial, executive function, and language), cardiac and neurological events, and mortality.

Methods

This single-blinded, two-group randomized-controlled pilot study will enroll 74 participants with HF. The Nature-VR intervention group will view three-dimensional nature pictures using a virtual reality headset for 10 minutes per day, 5 days per week for 4 weeks (a total of 200 minutes). The active comparison group, Urban-VR, will view three-dimensional urban pictures using a virtual reality headset to match the Nature-VR intervention in intervention dose and delivery mode, but not in content. After baseline interviews, four follow-up interviews will be conducted to assess sustained effects of Nature-VR at 4, 8, 26, and 52 weeks.

Discussion

The importance and novelty of this study consists of using a first-of-its kind, immersive virtual reality technology to target attention and in investigating the health outcomes of the Nature-VR cognitive intervention among patients with HF.

Pharmacological treatment other than corticosteroids, intravenous immunoglobulin and plasma exchange for Guillain-Barré syndrome

BACKGROUND

Plasma exchange and intravenous immunoglobulin, but not corticosteroids, are beneficial in Guillain-Barré syndrome (GBS). The efficacy of other pharmacological agents is unknown. This review was first published in 2011 and previously updated in 2013, and 2016.

OBJECTIVES

To assess the effects of pharmacological agents other than plasma exchange, intravenous immunoglobulin and corticosteroids for GBS.

SEARCH METHODS

On 28 October 2019, we searched the Cochrane Neuromuscular Specialised Register, CENTRAL, MEDLINE, and Embase for treatments for GBS. We also searched clinical trials registries.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) or quasi-RCTs of acute GBS (within four weeks from onset) of all types and degrees of severity, and in individuals of all ages. We discarded trials that investigated only corticosteroids, intravenous immunoglobulin or plasma exchange. We included other pharmacological treatments or combinations of treatments compared with no treatment, placebo or another treatment.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methodology.

MAIN RESULTS

We found six trials of five different interventions eligible for inclusion in this review. The trials were conducted in hospitals in Canada, China, Germany, Japan and the UK, and included 151 participants in total. All trials randomised participants aged 16 years and older (mean or median age in the trials ranged from 36 to 57 years in the intervention groups and 34 to 60 years in the control groups) with severe GBS, defined by the inability to walk unaided. One trial also randomised patients with mild GBS who were still able to walk unaided. We identified two new trials at this update.The primary outcome measure for this review was improvement in disability grade four weeks after randomisation. Four of six trials had a high risk of bias in at least one respect. We assessed all evidence for the outcome mean improvement in disability grade as very low certainty, which means that we were unable to draw any conclusions from the data. One RCT with 19 participants compared interferon beta-1a (IFNb-1a) and placebo. It is uncertain whether IFNb-1a improves disability after four weeks (mean difference (MD) -0.1; 95% CI -1.58 to 1.38; very low-certainty evidence). A trial with 10 participants compared brain-derived neurotrophic factor (BNDF) and placebo. It is uncertain whether BDNF improves disability after four weeks (MD 0.75; 95% CI -1.14 to 2.64; very low-certainty evidence). A trial with 37 participants compared cerebrospinal fluid (CSF) filtration and plasma exchange. It is uncertain whether CSF filtration improves disability after four weeks (MD 0.02; 95% CI -0.62 to 0.66; very low-certainty evidence). One trial that compared the Chinese herbal medicine tripterygium polyglycoside with corticosteroids with 43 participants did not report the risk ratio (RR) for an improvement by one or more disability grade after four weeks, but did report improvement after eight weeks. It is uncertain whether tripterygium polyglycoside improves disability after eight weeks (RR 1.47; 95% CI 1.02 to 2.11; very low-certainty evidence). We performed a meta-analysis of two trials comparing eculizumab and placebo with 41 participants. It is uncertain whether eculizumab improves disability after four weeks (MD -0.23; 95% CI -1.79 to 1.34; very low-certainty evidence). Serious adverse events were uncommon in each of the trials and evidence was graded as either low or very low. It is uncertain whether serious adverse events were more common with IFNb-1a versus placebo (RR 0.92, 95% CI 0.23 to 3.72; 19 participants), BNDF versus placebo (RR 1.00, 95% CI 0.28 to 3.54; 10 participants) or CSF filtration versus plasma exchange (RR 0.13, 95% CI 0.01 to 2.25; 37 participants). The trial of tripterygium polyglycoside did not report serious adverse events. There may be no clear difference in the number of serious adverse events after eculizumab compared to placebo (RR 1.90, 0.34 to 10.50; 41 participants). We found no clinically important differences in any of the outcome measures selected for this review in any of the six trials. However, sample sizes were small and therefore clinically important benefit or harm cannot be excluded.

AUTHORS' CONCLUSIONS

All six RCTs were too small to exclude clinically important benefit or harm from the assessed interventions. The certainty of the evidence was low or very low for all interventions and outcomes.

Abnormal TDP-43 function impairs activity-dependent BDNF secretion, synaptic plasticity, and cognitive behavior through altered Sortilin splicing

Aberrant function of the RNA-binding protein TDP-43 has been causally linked to multiple neurodegenerative diseases. Due to its large number of targets, the mechanisms through which TDP-43 malfunction cause disease are unclear. Here, we report that knockdown, aggregation, or disease-associated mutation of TDP-43 all impair intracellular sorting and activity-dependent secretion of the neurotrophin brain-derived neurotrophic factor (BDNF) through altered splicing of the trafficking receptor Sortilin. Adult mice lacking TDP-43 specifically in hippocampal CA1 show memory impairment and synaptic plasticity defects that can be rescued by restoring Sortilin splicing or extracellular BDNF. Human neurons derived from patient iPSCs carrying mutated TDP-43 also show altered Sortilin splicing and reduced levels of activity-dependent BDNF secretion, which can be restored by correcting the mutation. We propose that major disease phenotypes caused by aberrant TDP-43 activity may be explained by the abnormal function of a handful of critical proteins, such as BDNF.

Differential regulation of brain-derived neurotrophic factor (BDNF) expression in sensory neuron axons by miRNA-206

Distinct subcellular localization and subsequent translational control of 3′ UTR variants of mRNA encoding brain‐derived neurotrophic factor (BDNF) are critical for the development and plasticity of neurons. Although the processes that lead to preferential localization of BDNF have been well studied, it is still not clear how neurons ensure differential BDNF production in a spatial‐specific manner. Here, we identified that microRNA (miRNA)‐206 has the potential to specifically regulate BDNF with a long 3′ UTR without affecting its short 3′ UTR counterpart. Overexpression of miRNA‐206 in sensory neurons resulted in a 30% and 45% reduction of BDNF protein expression in the cell bodies and axons, respectively. The work described in the present study indicates that miRNAs can differentially and specifically regulate the expression of transcript variants with different localization patterns.

SORCS1 and SORCS3 control energy balance and orexigenic peptide production

SORCS1 and SORCS3 are two related sorting receptors expressed in neurons of the arcuate nucleus of the hypothalamus. Using mouse models with individual or dual receptor deficiencies, we document a previously unknown function of these receptors in central control of metabolism. Specifically, SORCS1 and SORCS3 act as intracellular trafficking receptors for tropomyosin-related kinase B to attenuate signaling by brain-derived neurotrophic factor, a potent regulator of energy homeostasis. Loss of the joint action of SORCS1 and SORCS3 in mutant mice results in excessive production of the orexigenic neuropeptide agouti-related peptide and in a state of chronic energy excess characterized by enhanced food intake, decreased locomotor activity, diminished usage of lipids as metabolic fuel, and increased adiposity, albeit at overall reduced body weight. Our findings highlight a novel concept in regulation of the melanocortin system and the role played by trafficking receptors SORCS1 and SORCS3 in this process.

Expression of BDNF and trkB in the hippocampus of a rat genetic model of vulnerability (Roman low-avoidance) and resistance (Roman high-avoidance) to stress-induced depression

INTRODUCTION

The selective breeding of Roman High- (RHA) and Low-Avoidance (RLA) rats for, respectively, rapid versus poor acquisition of the active avoidance response has generated two distinct phenotypes differing in many behavioral traits, including coping strategies to aversive conditions. Thus, RLA rats are considered as a genetic model of vulnerability to stress-induced depression whereas RHA rats are a model of resilience to that trait. Besides the monoamine hypothesis of depression, there is evidence that alterations in neuronal plasticity in the hippocampus and other brain areas are critically involved in the pathophysiology of mood disorders.

MATERIALS AND METHODS

Western blot (WB) and immunohistochemistry were used to investigate the basal immunochemical occurrence of brain-derived neurotrophic factor (BDNF) and its high-affinity tyrosine-kinase receptor trkB in the dorsal and ventral hippocampus of adult RHA and RLA rats.

RESULTS

WB analysis indicated that the optical density of BDNF- and trkB-positive bands in the dorsal hippocampus is, respectively, 48% and 25% lower in RLA versus RHA rats. Densitometric analysis of BDNF- and trkB-like immunoreactivity (LI) in brain sections showed that BDNF-LI is 24% to 34% lower in the different sectors of the Ammon's horn of RLA versus RHA rats, whereas line-related differences are observed in the dentate gyrus (DG) only in the ventral hippocampus. As for trkB-LI, significant differences are observed only in the dorsal hippocampus, where density is 23% lower in the DG of RLA versus RHA rats, while no differences across lines occur in the Ammon's horn.

CONCLUSION

These findings support the hypothesis that a reduced BDNF/trkB signaling in the hippocampus of RLA versus RHA rats may contribute to their more pronounced vulnerability to stress-induced depression.

Effects of Hint1 deficiency on emotional-like behaviors in mice under chronic immobilization stress

BACKGROUND

Histidine triad nucleotide-binding protein 1 (HINT1) is regarded as a haplo-insufficient tumor suppressor and is closely associated with diverse neuropsychiatric diseases. Moreover, HINT1 is related to gender-specific acute behavior changes in schizophrenia and in response to nicotine. Stress has a range of molecular effects in emotional disorders, which can cause a reduction in brain-derived neurotrophic factor (BDNF) expression in the hippocampus, resulting in hippocampal atrophy and neuronal cell loss.

METHODS

This study examined the role of HINT1 deficiency in anxiety-related and depression-like behaviors and BDNF expression in the hippocampus under chronic immobilization stress, and investigated whether the sex-specific and haplo-insufficient effects exist in emotional-like behaviors under the same condition.

RESULTS

In a battery of behavior tests, the results of the control group, not exposed to stress, showed that knockout (KO) and heterozygosity (HT) of Hint1 had anxiolytic-like and antidepression-like effects on the male and female mice. However, both male and female Hint1-KO mice showed elevated anxiety-related and antidepression-like behavior under chronic immobilization stress; moreover, both male and female Hint1-HT mice displayed elevated anxiety-related behavior and increased depression-like behavior under chronic immobilization stress. There were no significant differences in general locomotor activity between Hint1-KO and -HT mice and their wild-type (WT) littermates. Hint1-KO mice under basal and chronic immobilization stress conditions expressed more BDNF in the hippocampus than did Hint1-HT and WT mice; overall, there were no significant sex differences in emotional-like behaviors of Hint1-KO and -HT mice. Additionally, Hint1-HT mice showed haplo-insufficient effects on emotional-like behaviors under basic conditions, rather than under chronic immobilization stress.

CONCLUSIONS

Both male and female HINT 1 KO and HT mice had a trend of anxiolytic-like behavior and antidepression-like behavior at control group. However, both male and female HINT1 KO mice showed elevated anxiety-related and antidepression-like behavior under chronic immobilization stress; moreover, both male and female HINT1 HT mice displayed elevated anxiety-related behavior and increased depression-like behavior under chronic immobilization stress.

Pharmacological treatment other than corticosteroids, intravenous immunoglobulin and plasma exchange for Guillain-Barré syndrome

BACKGROUND

Plasma exchange and intravenous immunoglobulin, but not corticosteroids, are beneficial in Guillain-Barré syndrome (GBS). The efficacy of other pharmacological agents is unknown. This review was first published in 2011 and updated in 2013 and 2016.

OBJECTIVES

To assess the effects of pharmacological agents other than plasma exchange, intravenous immunoglobulin and corticosteroids for GBS.

SEARCH METHODS

On 18 January 2016, we searched the Cochrane Neuromuscular Specialised Register, Cochrane Central Register of Controlled Trials, MEDLINE, and Embase for treatments for GBS. We also searched clinical trials registries.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) or quasi-RCTs of acute GBS (within four weeks from onset) of all types and degrees of severity, and in individuals of all ages. We discarded trials that investigated only corticosteroids, intravenous immunoglobulin or plasma exchange. We included other pharmacological treatments or combinations of treatments compared with no treatment, placebo or another treatment. We also identified a number of non-randomised studies during the search, the results of which we considered in the Discussion.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methodology.

MAIN RESULTS

We identified no new trials during this update of the review. In previous versions of this review we identified only very low quality evidence for four different interventions published in four studies. Each study had a high risk of bias in at least one respect. One RCT with 19 participants comparing interferon beta-1a and placebo showed no clinically important difference in any outcome between groups. Another with 10 participants comparing brain-derived neurotrophic factor and placebo showed no clinically important difference in any outcome between groups. A third with 37 participants comparing cerebrospinal fluid filtration and plasma exchange also showed no clinically important difference in any outcome between groups. In a fourth with 43 participants, the risk ratio for an improvement by one or more disability grade after eight weeks was greater with the Chinese herbal medicine tripterygium polyglycoside than with corticosteroids (risk ratio 1.47; 95% confidence interval 1.02 to 2.11); other outcomes in this trial showed no difference. Serious adverse events were uncommon with each of these treatments and in the control groups.

AUTHORS' CONCLUSIONS

The quality of the evidence was very low. Three small RCTs, comparing interferon beta-1a or brain-derived neurotrophic factor with placebo, and cerebrospinal fluid filtration with plasma exchange, showed no significant benefit or harm for any of the interventions. A fourth small trial showed that the Chinese herbal medicine, tripterygium polyglycoside, hastened recovery in people with GBS to a greater extent than corticosteroids, but this result needs confirmation. We were unable to draw any useful conclusions from the few observational studies we identified.

BDNF prevents NMDA-induced toxicity in models of Huntington's disease: the effects are genotype specific and adenosine A2A receptor is involved

NMDA receptor-mediated excitotoxicity is thought to play a pivotal role in the pathogenesis of Huntington's disease (HD). The neurotrophin brain-derived neurotrophic factor (BDNF), which is also highly involved in HD and whose effects are modulated by adenosine A2 ARs, influences the activity and expression of striatal NMDA receptors. In electrophysiology experiments, we investigated the role of BDNF toward NMDA-induced effects in HD models, and the possible involvement of A2ARs. In corticostriatal slices from wild-type mice and age-matched symptomatic R6/2 mice (a model of HD), NMDA application (75 μM) induced a transient or a permanent (i.e., toxic) reduction of field potential amplitude, respectively. BDNF (10 ng/mL) potentiated NMDA effects in wild-type, while it protected from NMDA toxicity in R6/2 mice. Both effects of BDNF were prevented by A2 AR blockade. The protective effect of BDNF against NMDA-induced toxicity was reproduced in a cellular model of HD. These findings may have very important implications for the neuroprotective potential of BDNF and A2 AR ligands in HD.