Biology subjects

Forrest, L.

Publications and source records attributed to Forrest, L..

3 recordsLinked to original sources

bioRxiv2025

Spatially resolved fetal and maternal cell contributions to severe Preeclampsia

The molecular and cellular pathophysiology of the fetal-maternal interface in preeclamsia remains poorly understood, but it is increasingly clear that both fetus and mother make independent contributions to it. Here, we spatially distinguish them from each other and from gestational age for the severe form of the disease, interrogating tissues and cell types beyond the placenta for the Early and Late presentation of the condition. In addition to concerted hypoxia, angiogenic imbalance, fibrosis and aberrant metabolism in the placenta, new maternal immune signatures, including changes in macrophages, mitochondrial dysfunction and interferon signalling in the placenta, myometrium or chorioamniotic membranes, offer an explanation to systemic inflammation and endothelial dysfunction in the mother. These tissue and cell-specific responses are potential targets for therapy, with their prompt consideration in Early gestational disease likely beneficial due to its severity. Thus, timely intervention during gestation could change the extremely poor prognosis of severe disease.

molecular biology↗

bioRxiv2025

Leafy liverwort genomes shed light on the evolution of ericoid symbiosis

Symbioses have been fundamental to colonization of terrestrial ecosystems by plants and their evolution. Emergence of the ancient arbuscular mycorrhizal symbiosis was followed by the diversification of alternative intracellular symbioses, such as the ericoid mycorrhizae (ErM). We aimed at understanding how these diversifications occurred. We sequenced the genomes of ErM-forming liverworts, and reconstituted symbiosis under laboratory conditions. We demonstrated the existence of a nutrient-regulated symbiotic state that enables ErM and underlies intracellular colonization of plant tissues. Comparative transcriptomic analyses identified an ancestral gene module associated with intracellular symbiosis beyond ErM. Genetic manipulations in the liverwort Marchantia paleacea, phylogenetics and transactivation assays demonstrated its essential function for intracellular symbiosis. We conclude that plant have maintained, and convergently recruited, an ancestral gene module for intracellular symbioses.

plant biology↗

bioRxiv2020

Chloride-dependent conformational changes in the GlyT1 glycine transporter

The human GlyT1 glycine transporter requires chloride for its function. However, the mechanism by which Cl- exerts its influence is unknown. To examine the role that Cl- plays in the transport cycle, we measured the effect of Cl- on both glycine binding and conformational changes. The ability of glycine to displace the high-affinity radioligand [3H]CHIBA-3007 required Na+ and was potentiated over 1000-fold by Cl-. We generated GlyT1b mutants containing reactive cysteine residues in either the extracellular or cytoplasmic permeation pathways and measured changes in the reactivity of those cysteine residues as indicators of conformational changes in response to ions and substrate. Na+ increased accessibility in the extracellular pathway and decreased it in the cytoplasmic pathway, consistent with stabilizing an outward-open conformation as observed in other members of this transporter family. In the presence of Na+, both glycine and Cl- independently shifted the conformation of GlyT1b toward an outward-closed conformation. Together, Na+, glycine and Cl- stabilized an inward-open conformation of GlyT1b. We then examined whether Cl- acts by interacting with a conserved glutamine to allow formation of an ion pair that stabilizes the closed state of the extracellular pathway. Molecular dynamics simulations of a GlyT1 homologue indicated that this ion pair is formed more frequently as that pathway closes. Mutation of the glutamine blocked the effect of Cl-, and substituting it with glutamate or lysine resulted in outward- or inward-facing transporter conformations, respectively. These results provide novel and unexpected insight into the role of Cl- in this family of transporters.

biochemistry↗