Biology subjects

Moon, E.

Publications and source records attributed to Moon, E..

5 recordsLinked to original sources

bioRxiv2026

Thermodynamic properties and stability of HMGB1 complexes with linear polyelectrolytes elucidated by nano differential scanning fluorimetry

The High Mobility Group Box 1 (HMGB1) protein performs multiple essential functions in the body, ranging from DNA regulation to the activation and mediation of immune responses. However, HMGB1 has been also implicated in several pathological conditions, such as rheumatoid arthritis, sepsis, autoimmune diseases, tumors, and Alzheimer's disease. As a result, HMGB1 is of increasing interest as a therapeutic target. Binding to heparin has been reported to inhibit HMGB1's pathological activity during sepsis in clinical settings. In this work, we compare the interactions of HMGB1 with heparin and its' synthetic analog linear polyglycerol sulfate (lPGS) from the viewpoint of stability and changes to association behavior. This analysis focuses on thermal stability, secondary-structure changes, and particle-size evolution using nano-differential scanning fluorimetry (nanoDSF), circular dichroism spectroscopy (CD), and dynamic light scattering (DLS).

biochemistry↗

bioRxiv2026

Glycosaminoglycans Promote Amyloid-β Aggregation via Multivalent, pH-Dependent Interactions

Glycosaminoglycans (GAGs) are polyanionic polysaccharides that co-localize with amyloid-{beta} (A{beta}) deposits in Alzheimers disease, yet their mechanistic contribution to A{beta} aggregation remains unclear. Here, we show that GAGs function as pH-responsive electrostatic scaffolds that selectively accelerate A{beta}(1-42) aggregation under mildly acidic, endosomal conditions but not at neutral extracellular pH. Combining experimental and computational approaches, we identify protonated N-terminal histidines as key determinants of GAG binding. Weak interactions between GAGs and the charged Nterminal region of A{beta} promote conformational rearrangements that bring peptides into proximity and expose adjacent hydrophobic aggregation-prone segments, thereby facilitating peptide clustering. Kinetic analyses reveal that aggregation is enhanced in a way consistent with an apparent increase in effective peptide concentration, accelerating nucleation without altering the dominant aggregation pathway. Systematic variation of GAG chain length and sulfation level further demonstrates that aggregation enhancement requires a threshold degree of multivalency, consistent with a clustering-driven mechanism. Together, these findings establish a framework in which pH-dependent electrostatic interactions with GAGs act as molecular triggers of amyloid nucleation, providing insight into how cellular microenvironments regulate the earliest stages of Alzheimers disease pathology.

biophysics↗

bioRxiv2025

Microengineered transplantation of human solid tumors for in vitro studies of CAR T immunotherapy

Treatment of solid malignancies using chimeric antigen receptor (CAR) T cells remains a significant challenge, but current efforts to advance this therapy are challenged by our limited capacity to probe and understand cancer-immune interactions in human solid tumors. Here, we present a microengineered platform for in vitro modeling of malignant solid tumors during CAR T therapy. This system makes it possible to vascularize human tumor explants and perfuse them with blood-borne immune cells in a controlled manner. We first present a microphysiological model of human lung adenocarcinomas infused with CAR-T cells and show how this system can be used to simulate, visualize, and interrogate tumor-directed trafficking and effector function of CAR T cells. We then demonstrate the proof-of-principle of testing a chemokine-directed CAR T cell engineering strategy in a model of malignant pleural mesothelioma and validating our in vitro assessment using a matching in vivo mouse model. Finally, we describe a potential therapeutic target discovered by single-cell RNA sequencing that can be pharmacologically modulated to increase the efficacy of CAR T cells for lung adenocarcinoma, for which we also present specific biomarkers identified by global metabolomics analysis. We believe that the bioengineering principle demonstrated here will make important contributions to developing new capabilities for preclinical studies of adoptive cell therapies for cancer and other complex diseases.

bioengineering↗

bioRxiv2025

Amyloid fibrils in Alzheimer's disease differently modulate sleep and cortical oscillations in mice depending on the type of amyloid

Alzheimers disease (AD) is characterized by aggregation and deposition of the amyloid-beta (A{beta}) protein in patient brains, with aging playing a crucial role through oxidative stress and neuroinflammation. Sleep disturbances are common in patients with AD, and contribute to their cognitive impairment. However, the association between the aggregation of specific A{beta} species in particular brain regions and its effect on sleep impairment remains unclear. Here, we investigated the effect of A{beta}1-40 (A{beta}40) and A{beta}1-42 (A{beta}42) amyloid fibrils on sleep/wakefulness and cortical oscillations in 3-month old wild-type mice. A{beta}42 aggregated faster and demonstrated distinct structural properties compared with A{beta}40. Bilateral injections into the dentate gyrus of the hippocampus showed that A{beta}42 amyloid fibrils significantly disrupted sleep and cortical activity as well as caused neuronal death, whereas A{beta}40 amyloid fibrils mainly affected cortical oscillations and caused minimal neuronal death. These findings shed light on AD-associated sleep disorders, which are differentially affected by the distinct properties of A{beta}40 and A{beta}42 aggregates.

neuroscience↗

bioRxiv2021

Role of the G-Protein Coupled Receptor 3-Salt Inducible Kinase 2 Pathway in Human β CellProliferation

Loss of pancreatic {beta} cells is the hallmark of type 1 diabetes (T1D) 1, for which provision of insulin is the standard of care. While regenerative and stem cell therapies hold the promise of generating single-source or host-matched tissue to obviate immune-mediated complications2-4, these will still require surgical intervention and immunosuppression. Thus, methods that harness the innate capacity of {beta}-cells to proliferate to increase {beta} cell mass in vivo are considered vital for future T1D treatment5, 6. However, early in life {beta} cells enter what appears to be a permanent state of quiescence 7-10, directed by an evolutionarily selected genetic program that establishes a {beta} cell mass setpoint to guard against development of fatal endocrine tumours. Here we report the development of a high-throughput RNAi screening approach to identify upstream pathways that regulate adult human {beta} cell quiescence and demonstrate in a screen of the GPCRome that silencing G-protein coupled receptor 3 (GPR3) leads to human pancreatic {beta} cell proliferation. Loss of GPR3 leads to activation of Salt Inducible Kinase 2 (SIK2), which is necessary and sufficient to drive cell cycle entry, increase {beta} cell mass, and enhance insulin secretion in mice. Taken together, targeting the GPR3-SIK2 pathway represents a novel avenue to stimulate the regeneration of {beta} cells.

cell biology↗