No abstract

Abnormal uptake or metabolism of folate increases risk of human pregnancy complications, though the mechanism is unclear. Here, we explore how defective folate metabolism influences early development by analysing mice with the hypomorphic Mtrrgt mutation. MTRR is necessary for methyl group utilisation from folate metabolism, and the Mtrrgt allele disrupts this process. We show that the spectrum of phenotypes previously observed in Mtrrgt/gt conceptuses at embryonic day (E) 10.5 is apparent from E8.5 including developmental delay, congenital malformations, and placental phenotypes. Notably, we report misalignment of some Mtrrgt conceptuses within their implantation sites from E6.5. The degree of misorientation occurs across a continuum, with the most severe form visible upon gross dissection. Additionally, some Mtrrgt/gt conceptuses display twinning. Therefore, we implicate folate metabolism in blastocyst orientation and spacing at implantation. Skewed growth likely influences embryo development since developmental delay and heart malformations (but not defects in neural tube closure or trophoblast differentiation) associate with severe misalignment of Mtrrgt/gt conceptuses. Typically, the uterus is thought to guide conceptus orientation. To investigate a uterine effect of the Mtrrgt allele, we manipulate the maternal Mtrr genotype. Misaligned conceptuses were observed in litters of Mtrr+/+, Mtrr+/gt, and Mtrrgt/gt mothers. While progesterone and/or BMP2 signalling might be disrupted, normal decidual morphology, patterning, and blood perfusion are evident at E6.5 regardless of conceptus orientation. These observations argue against a post-implantation uterine defect as a cause of conceptus misalignment. Since litters of Mtrr+/+ mothers display conceptus misalignment, a grandparental effect is explored. Multigenerational phenotype inheritance is characteristic of the Mtrrgt model, though the mechanism remains unclear. Genetic pedigree analysis reveals that severe conceptus skewing associates with the Mtrr genotype of either maternal grandparent. Moreover, the presence of conceptus skewing after embryo transfer into a control uterus indicates that misalignment is independent of the peri- and/or post-implantation uterus and instead is likely attributed to an embryonic mechanism that is epigenetically inherited. Overall, our data indicates that abnormal folate metabolism influences conceptus orientation over multiple generations with implications for subsequent development. This study casts light on the complex role of folate metabolism during development beyond a direct maternal effect.

No abstract

Freezing of gait (FOG) is a common occurrence in patients with Parkinson's disease (PD) that leads to significant limitations in mobility and increases risk of falls. Focused vibrotactile stimulation and cueing are two methods used to alleviate motor symptoms, including FOG, in patients with PD. While effective on their own, the effect of combining both focused vibrotactile stimulation and cueing has yet to be investigated. Two patients, both with a history of PD, suffered from frequent FOG episodes that failed to respond adequately to medication. A novel vibrotactile stimulation device that delivered rhythmic kinesthetic stimuli onto the sternum successfully reduced FOG episodes in both patients and drastically improved their mobility as measured by the Timed Up and Go test. We found that a combination of focused vibrotactile stimulation and cueing was effective in reducing FOG episodes in two patients with PD. Further well-designed prospective studies are needed to confirm our observations.

Abnormal uptake or metabolism of folate increases risk of human pregnancy complications, though the mechanism is unclear. Here, we explore how defective folate metabolism influences early development by analysing mice with an Mtrrgt hypomorphic mutation. MTRR is necessary for methyl group utilisation from the folate cycle, and the Mtrrgt allele disrupts this process. We show that the spectrum of phenotypes previously observed in Mtrrgt/gt conceptuses at embryonic day (E) 10.5 is apparent from E8.5 including developmental delay, congenital malformations, and placental phenotypes (e.g., eccentric chorioallantoic attachment). Notably, we report misalignment of some Mtrrgt conceptuses within their implantation sites from E6.5. The degree of skewed growth occurs across a continuum, with eccentric chorioallantoic attachment now re-characterised as a severe form of conceptus misalignment. Additionally, some Mtrrgt/gt conceptuses display twinning. Therefore, we implicate folate metabolism in blastocyst orientation and spacing at implantation. Embryo development is influenced by skewed growth since developmental delay and heart malformations (but not neural tube defects) associate with severe misalignment of Mtrrgt/gt conceptuses. Patterning of trophoblast lineage markers is largely unaffected in skewed Mtrrgt/gt conceptuses at E8.5 indicating trophoblast differentiation was normal when misaligned. Typically, the uterus guides conceptus orientation. Accordingly, we manipulate the maternal Mtrr genotype and assess conceptus alignment. Mtrr+/gt, and Mtrrgt/gt mothers, plus Mtrr+/+ mothers, exhibit misaligned conceptuses at E6.5. While progesterone and/or BMP2 signalling required for decidualisation might be disrupted, normal gross decidual morphology, patterning, and blood perfusion is evident regardless of conceptus alignment, arguing against a uterine defect. Given the important finding that Mtrr+/+ mothers also display conceptus misalignment, a grandparental effect is explored. Multigenerational phenotype inheritance is characteristic of the Mtrrgt model, though the mechanism remains unclear. Genetic pedigree analysis reveals that severe skewing associates with the Mtrr genotype of either maternal grandparent. Moreover, misalignment is independent of the uterus and instead is attributed to an embryonic mechanism based on blastocyst transfer experiments. Overall, our data indicates that abnormal folate metabolism influences conceptus orientation over multiple generations with implications for subsequent development. Our study casts light on the complex role of folate metabolism during development beyond a direct maternal effect.