BackgroundMigraine is a common neurovascular condition that may be linked to hyperhomocysteinemia. We have previously provided evidence that reduction of homocysteine with a vitamin supplementation can reduce the occurrence of migraine in women. The current study examined the occurrence of migraine in response to vitamin supplementation with a lower dose of folic acid.MethodsThis was a 6 month randomised, double blinded placebo controlled trial of daily vitamin supplementation containing 1 mg of folic acid, 25 mg of Vitamin B6 and Vitamin B12, on reduction of homocysteine and the occurrence of migraine in 300 female patients diagnosed with migraine with aura.ResultsVitamin supplementation with 1 mg of folic acid, did not significantly decrease homocysteine levels (P = 0.2). The treatment group did not show a significant decrease in the percentage of participants with high migraine disability, severity or frequency at the end of the 6 month intervention (P > 0.1).Conclusion1 mg of folic acid in combination with vitamin B6 and B12 is less effective in reducing migraine associated symptoms compared to the previously tested dosage of 2 mg folic acid in combination with 25 mg of vitamin B6 and 400 μg of vitamin B12.

Brain-derived neurotrophic factor (BDNF) is involved in numerous cognitive functions including learning and memory. BDNF plays an important role in synaptic plasticity in humans and rats with BDNF shown to be essential for the formation of long-term memories. We previously identified a significant association between the BDNF Val66Met polymorphism (rs6265) and long-term visual memory (p-value = 0.003) in a small cohort (n = 181) comprised of healthy individuals who had been phenotyped for various aspects of memory function. In this study, we have extended the cohort to 597 individuals and examined multiple genetic variants across both the BDNF and BDNF-AS genes for association with visual memory performance as assessed by the Wechsler Memory Scale-Fourth Edition subtests Visual Reproduction I and II (VR I and II). VR I assesses immediate visual memory, whereas VR II assesses long-term visual memory. Genetic association analyses were performed for 34 single nucleotide polymorphisms genotyped on Illumina OmniExpress BeadChip arrays with the immediate and long-term visual memory phenotypes. While none of the BDNF and BDNF-AS variants were shown to be significant for immediate visual memory, we found 10 variants (including the Val66Met polymorphism (p-value = 0.006)) that were nominally associated, and three variants (two variants in BDNF and one variant in the BDNF-AS locus) that were significantly associated with long-term visual memory. Our data therefore suggests a potential role for BDNF, and its anti-sense transcript BDNF-AS, in long-term visual memory performance.

Generating neurons from human stem cells has potential for brain damage therapy and neurogenesis modeling, but current efficacy is limited by culture heterogeneity and the lack of markers. We have previously reported the heparan sulfate proteoglycans (HSPGs) glypican‐1 (GPC1) and ‐4 (GPC4) as the markers of lineage‐specific human neural stem cells (hNSCs) and mediators of hNSC lineage potential. Here, we further examined phenotypical characteristics and GPC1 and GPC4 during neural differentiation of hNSCs in the presence of two neurogenic growth factors reported to bind to heparan sulfate: brain‐derived neurotrophic factor (BDNF) and platelet‐derived growth factor‐B (PDGF‐B). In hNSC neural cultures, GPC1 and GPC4 were expressed along neurites and cell bodies in long‐term (40–60 days) neural differentiation cultures demonstrating the areas of differential localization—suggesting potentially different functions. Neural differentiation cultures in the presence of BDNF or PDGF‐B generated phenotypically different neural cells with BDNF treatment associated with higher GPC4 versus GPC1 expression, increased heterogeneity, and differential neuron subtype marker expression to PDGF‐B cultures. PDGF‐B cultures exhibited higher levels of spontaneous activity and reduced heterogeneity over long‐term culture associated with decreased GPC4. Untreated neural cultures were highly variable, supporting the use of neuroregulatory growth factors for guided differentiation. Targeted siRNA downregulation of GPC1/4 reduced neural differentiation markers and altered response to exogenous BDNF and PDGF‐B. This work confirms GPC1 and GPC4 as regulators of human neural differentiation and supports their use as novel markers of neural cell characterization.

Background The long introns of mammals are pools of evolutionary potential due to the multiplicity of sequences that permit the acquisition of novel exons. However, the permissibility of genes to this type of acquisition and its influence on the evolution of cell regulation is poorly understood. Results Here, we observe that human genes are highly permissive to the inclusion of novel exonic regions permitting the emergence of novel regulatory features. Our analysis reveals the potential for novel exon acquisition to occur in over 30% of evaluated human genes. Regulatory processes including the rate of splicing efficiency and RNA polymerase II (RNAPII) elongation control this process by modulating the “window of opportunity” for spliceosomal recognition. DNA damage alters this window promoting the inclusion of repeat-derived novel exons that reduce the ribosomal engagement of cell cycle genes. Finally, we demonstrate that the inclusion of novel exons is suppressed in hematological cancer samples and can be reversed by drugs modulating the rate of RNAPII elongation. Conclusion Our work demonstrates that the inclusion of repeat-associated novel intronic regions is a tightly controlled process capable of expanding the regulatory capacity of cells. Electronic supplementary material The online version of this article (10.1186/s13059-019-1757-5) contains supplementary material, which is available to authorized users.