Randomized double-blind placebo-controlled trial of the effects of oral trehalose in spinocerebellar ataxia type 3: An interim analysis.

INTRODUCTION: Spinocerebellar ataxia type 3 (SCA3) is a neurodegenerative disease characterized by increasingly worsening ataxia and non-ataxia features, negatively impacting patients' quality of life. This study was designed to test formally evaluate whether oral trehalose was effective in SCA3 patients. METHODS: In this double-blind, randomized controlled trial, SCA3 patients received either 100 g oral trehalose or 30 g maltose to improve ataxia severity over six months. We also measured other clinical (non-ataxia), patient-reported (quality of life, motivations), and safety endpoints. An unscheduled interim analysis was conducted using two-way ANOVAs to analyze the interaction between time (baseline, 3-months, 6-months) and intervention (Trehalose vs. Placebo). RESULTS: Fifteen participants (Trehalose = 7 vs. Placebo = 8) completed the study at the time of interim analysis. There was no interaction effect on the ataxia severity, and available data suggested an estimated sample size of 132 (66 per arm) SCA3 patients required to demonstrate changes in a 6-month trial. There were significant interaction effects for executive function (ƞ2 = 0.28-0.43). Safety data indicated that 100 g oral trehalose was well-tolerated. CONCLUSION: We performed an unplanned interim analysis due to a slow recruitment rate. The new estimated sample size was deemed unfeasible, leading to premature termination of the clinical trial. In this small, current sample of SCA3 patients, 100 g oral trehalose did not differentially impact on ataxia severity compared to placebo. Interestingly, our findings may suggest an improvement in executive function. Future efforts will require a large multi-country, multi-center study to investigate the potential effect of trehalose.

Alpha- and Gamma-Tocopherol Modulates the Amyloidogenic Pathway of Amyloid Precursor Protein in an in vitro Model of Alzheimer's Disease: A Transcriptional Study.

The amyloid precursor protein (APP) processing pathway was altered in Alzheimer's disease (AD) and contributed to abnormal amyloid-beta (Aß) production, which forms insoluble interneuron protein aggregates known as amyloid plaques in the brain. Targeting the APP processing pathway is still fundamental for AD modifying therapy. Extensive research has evaluated the protective effects of vitamin E as an antioxidant and as a signaling molecule. The present study aimed to investigate the modulatory effects of different tocopherol isomers on the expression of genes involved in regulating the APP processing pathway in vitro. The screening for the effective tocopherol isomers in reducing APP expression and Aß-42 was carried out in SH-SY5Y stably overexpressed APP Swedish. Subsequently, quantitative one-step real-time PCR was performed to determine the modulatory effects of selected tocopherol isomers on the expression of genes in SH-SY5Y stably overexpressed three different types of APP (wild-type, APP Swedish, and APP Swedish/Indiana). Our results showed that all tocopherol isomers, especially at higher concentrations (80-100 µM), significantly increased (p < 0.05) the cell viability in all cells group, but only α-tocopherol (ATF) and γ-tocopherol (GTF) significantly decreased (p < 0.05) the APP mRNA level without statistically significant APP protein level, accompanied with a reduced significance (p < 0.05) on the level of Aß-42 in SH-SY5Y APP Swedish. On the other hand, ß- and δ-tocopherol (BTF and DTF) showed no effects on the level of APP expression and Aß-42. Subsequent results demonstrated that ATF and GTF significantly decreased (p < 0.05) the expression of gene beta-site APP cleaving enzyme (BACE1), APH1B, and Nicastrin (NCSTN), but significantly increased (p < 0.05) the expression of Sirtuin 1 (SIRT1) in SH-SY5Y stably expressed the mutant APP form. These findings suggested that ATF and GTF could modulate altered pathways and may help ameliorate the burden of amyloid load in AD.

The Role of Oxidative Stress in Suicidal Behaviour Among Bipolar Patients: A Cross-Sectional Study in a Malaysian Sample.

Background: Oxidative stress markers are found to be linked with depression and suicide attempts in bipolar disorder (BD), although the role of DNA damage as a marker of suicidal ideation and attempt has yet to be determined. We aim to investigate the association between DNA damage and suicidal behaviour, i.e., suicidal ideation and suicide attempt, among suicidal ideators in BD patients while accounting for clinical and psychosocial risk factors. Methods: A cross-sectional study was conducted in the Universiti Kebangsaan Malaysia Medical Centre on 62 consecutive BD patients diagnosed using the M.I.N.I. Neuropsychiatric Interview and 26 healthy control participants. Socio-demographic and clinical assessments were performed using the Columbia Suicide Severity Rating Scale (C-SSRS) for lifetime suicidal ideation and attempt, Quick Inventory of Depressive Symptomatology (QIDS) for depression severity, Clinical Global Impression for Bipolar Disorder (CGI-BD) for illness severity [both mania (CGI-Mania) and major depressive episode (CGI-MDE)], Social Readjustment Rating Scale (SRRS) for change in life events, and Barratt Impulsiveness Scale (BIS) for behavioural impulsivity. The degree of DNA damage in peripheral blood samples was determined using a standard protocol of comet assay. Results: Multivariable logistic regression revealed higher scores of CGI-MDE as the sole significant factor for lifetime suicidal ideation (OR = 1.937, 95% CI = 1.799-2.076). Although initial bivariate analysis showed a significant association between DNA damage, malondialdehyde (MDA), catalase (CAT), and suicidal behaviour, the findings were not seen in multivariable logistic regression. Bivariate subgroup analysis showed that moderate and severe DNA damage (p = 0.032 and p = 0.047, respectively) was significantly associated with lifetime suicide attempts among lifetime suicidal ideators. The study is the first to look at the connexion between DNA damage and suicidal risk in bipolar patients. It is limited by the small sample size and lack of information on illicit substance use. Conclusions: More severe DNA damage was significantly associated with lifetime suicide attempts among lifetime suicidal ideators in BD. However, the severity of depression was found to be independently associated with lifetime suicidal ideation per se rather than DNA damage in BD. Larger prospective studies are required to ascertain the potential of DNA damage as a biomarker for the transition from suicidal ideation to a suicide attempt.

Modulatory Effects of Alpha- and Gamma-Tocopherol on the Mitochondrial Respiratory Capacity and Membrane Potential in an In Vitro Model of Alzheimer's Disease.

Increased amyloid-beta (Aß) and amyloid precursor protein (APP) in the brains of Alzheimer's disease (AD) patients are common pathological hallmarks mediating the disease progression. Growing evidence also suggests that mitochondrial abnormalities are an early feature in the pathogenesis of AD. Intervention with antioxidants has received great interest as a molecular strategy for the manipulation of mitochondrial function. Our previous preliminary study using in vitro cell models expressing different types of APP demonstrated that treatment with alpha-tocopherol (ATF) or gamma-tocopherol (GTF) modulates mitochondrial function by reducing mitochondrial reactive oxygen species (ROS), increasing the production of ATP and preventing apoptosis events, especially in cells expressing the mutant APP form. Thus, we hypothesized that ATF or GTF treatment might also alter mitochondrial metabolic pathways such as oxidative phosphorylation. The present study aimed to investigate the role of ATF and GTF in modulating mitochondrial oxidative metabolism using high-resolution respirometry. Our results showed that both ATF and GTF increased the respiratory capacity and membrane potential in the ROUTINE and OXPHOSCI-LINKED states as well as complex IV enzyme activity in wild-type and mutant APP-overexpressing SH-SY5Y cells. Although preliminary, these findings indicate that ATF and GTF modulate mitochondrial oxidative metabolism in APP-overexpressing cells and, in part, may contribute to the planning of strategies for utilizing vitamin E isomers against mitochondrial-related diseases such as AD.

Elevation of tumour markers TGF-ß, M2-PK, OV-6 and AFP in hepatocellular carcinoma (HCC)-induced rats and their suppression by microalgae Chlorella vulgaris.

BACKGROUND: Chlorella vulgaris (ChV), a unicellular green algae has been reported to have anticancer and antioxidant effects. The aim of this study was to determine the chemopreventive effect of ChV on liver cancer induced rats by determining the level and expression of several liver tumour markers. METHODS: Male Wistar rats (200-250 g) were divided into 4 groups according to the diet given: control group (normal diet), ChV group with three different doses (50, 150 and 300 mg/kg body weight), liver cancer- induced group (choline deficient diet + 0.1% ethionine in drinking water or CDE group), and the treatment group (CDE group treated with three different doses of ChV). Rats were killed at 0, 4, 8 and 12 weeks of experiment and blood and tissue samples were taken from all groups for the determination of tumour markers expression alpha-fetoprotein (AFP), transforming growth factor-ß (TGF-ß), M2-pyruvate kinase (M2-PK) and specific antigen for oval cells (OV-6). RESULTS: Serum level of TGF-ß increased significantly (p < 0.05) in CDE rats. However, ChV at all doses managed to decrease (p < 0.05) its levels to control values. Expressions of liver tumour markers AFP, TGF-ß, M2-PK and OV-6 were significantly higher (p < 0.05) in tissues of CDE rats when compared to control showing an increased number of cancer cells during hepatocarcinogenesis. ChV at all doses reduced their expressions significantly (p < 0.05). CONCLUSIONS: Chlorella vulgaris has chemopreventive effect by downregulating the expression of tumour markers M2-PK, OV-6, AFP and TGF-ß, in HCC-induced rats.