Serum insulin-like system alterations in patients with spinocerebellar ataxia type 3.

Spinocerebellar ataxias (SCAs) constitute a group of autosomal dominant neurodegenerative disorders with no current treatment. The insulin/insulin-like growth factor 1 (IGF-1) system (IIS) has been shown to play a role in the neurological dysfunction of SCAs and other polyglutamine disorders. We aimed to study the biomarker profile of serum IIS components in SCA3. We performed a case-control study with 46 SCA3 patients and 42 healthy individuals evaluating the peripheral IIS profile (insulin, IGF-1, IGFBP1 and 3) and the correlation with clinical, molecular, and neuroimaging findings. SCA3 patients presented lower insulin and IGFBP3 levels and higher insulin sensitivity (HOMA2), free IGF-I, and IGFBP1 levels when compared with controls. IGFBP-1 levels were directly associated with CAG expanded repeat length; IGF-1 was associated with the volumetries of specific brainstem regions on magnetic resonance imaging (MRI). Insulin levels and sensitivity were related to age at onset of symptoms. Our findings indicate an involvement of IIS components in SCA3 neurobiology and IGFBP-1 as a potential biomarker of the disease.

Maternal consumption of high-fat diet and grape juice modulates global histone H4 acetylation levels in offspring hippocampus: A preliminary study.

This study aimed to investigate the impact of maternal consumption of a hyperlipid diet and grape juice on global histone H4 acetylation levels in the offsprinǵs hippocampus at different stages of development. During pregnancy and lactation of offspring, dams were divided into 4 groups: control diet (CD), high-fat diet (HFD), control diet and purple grape juice (PGJCD) and purple grape juice and high-fat diet (PGJHFD). Male Wistar rats were euthanized at 21days of age (PN21, adolescents) and at 50days of age (PN50, adults). The maternal consumption of grape juice increased global histone H4 acetylation levels in hippocampus of adolescents pups (PN21), an indicative of enhanced transcriptional activity and increased gene expression. On the other hand, the maternal high-fat diet diminished significantly this epigenetic marker in the adult phase (PN50), suggesting gene silencing. These preliminary findings demonstrated that the maternal choices are able to induce changes on histone H4 acetylation status in hippocampus of the offspring, which may modulate the expression of specific genes. Interestingly, this response occurs in an age and stimuli-dependent manner and strongly reinforce the importance of maternal choices during gestation.

The modulation of inflammatory parameters, Brain-derived neurotrophic factor levels and global histone H4 acetylation status in peripheral blood of patients with Gaucher disease type 1.

OBJECTIVES: Gaucher's disease type 1 (GD1) pathophysiology includes an imbalance on brain-derived neurotrophic factor (BDNF) levels and in the inflammatory system. However, the pathways involved remain poorly understood. The hypothesis of this study is that epigenetic mechanisms might be involved, at least partially, in this phenomenon. DESIGN AND METHODS: This study investigated the BDNF modulation, global histone H4 acetylation and pro- and anti-inflammatory cytokines levels in the peripheral blood of GD1 patients (n=10) when compared with control samples (CS) (n=11). RESULTS: The results showed a significant increase in Chitotriosidase (CT) (p=0.019) and decreased ß-glucosidase (GBA) activities (p=0.001) in GD1 samples when compared to CS, for GD1 diagnostic confirmation. Reduced levels of BDNF (p=0.004) and elevated levels of TNF-α (p=0.017) and IL-4 (p=0.035) were also found in the GD group. No significant differences were observed in IL-6 or IL-17a levels between groups (p>0.05). Finally, a trend on higher global histone H4 acetylation levels (p=0.054) was observed in the control group when compared to GD1 individuals. CONCLUSIONS: Combined, these results suggest inflammatory cytokines imbalance, reduced BDNF levels and global histone H4 hypoacetylation status in GD type 1 physiopathology. These preliminary findings may open new avenues to introduce therapies and strategies in the preventive management and treatment of this population.

U18666A Treatment Results in Cholesterol Accumulation, Reduced Na(+), K(+)-ATPase Activity, and Increased Oxidative Stress in Rat Cortical Astrocytes.

The objective of this study was to determine the effect of U18666A, an inhibitor of cholesterol synthesis and its intracellular transport, on oxidative stress parameters in cortical astrocytes cultured from Wistar rats (0-3 days old). The cultures were incubated with U18666A (0.25 µg/mL) for 48 h, conditions that are considered ideal to mimic Niemann-Pick type C disease. A variety of indicators of oxidative stress were measured. U18666A treatment increased cholesterol 2-fold in treated compared to control astrocytes. Oxidative stress was significantly elevated in treated cells as demonstrated by a 1.7-fold increase in thiobarbituric acid reactive substances, a 60% decrease is sulfhydral groups, and a 3.7-fold increase in carbonyl groups, indicative of increased lipid and protein oxidation following U18666A treatment. Consistent with these changes, both catalase and superoxide dismutase activities were significantly reduced nearly 50% in treated compared to control astrocytes. Collectively, these change resulted in a 50% reduction in Na(+), K(+)-ATPase specific activity following U18666A treatment, suggesting a significant alteration in its plasma membrane environment. Overall, these changes indicate that U18666A treatment results in increased cholesterol levels and an increased level of oxidative stress in cortical astrocytes, consistent with what is observed in Niemann-Pick type C disease.