Biology subjects

Seki, E.

Publications and source records attributed to Seki, E..

3 recordsLinked to original sources

bioRxiv2026

Dual targeting of astrocytic and endothelial GLUT1 enables functional rescue in GLUT1 deficiency syndrome

Glucose transporter 1 deficiency syndrome (GLUT1-DS) is a severe neurometabolic disorder caused by impaired brain glucose transport. Because GLUT1 has been classically viewed as predominantly localized to blood-brain barrier endothelial cells, gene therapy strategies have largely focused on endothelial GLUT1 restoration. However, whether this endothelial-centered model fully explains disease pathogenesis and therapeutic rescue has remained unclear. Using enhanced detection in mouse brain and human postmortem tissue, we show that GLUT1 is broadly expressed in astrocytes as well as endothelial cells, extending beyond perivascular endfeet into astrocytic somata and processes. Conditional Glut1 haploinsufficiency in either astrocytes or endothelial cells reproduced GLUT1-DS-like reductions in cerebrospinal fluid glucose availability and brain parenchymal glucose responses, together with cognitive and motor impairments. To determine the therapeutic consequence of this revised cellular model, we used complementary endothelial- and astrocyte-directed AAV delivery to restore GLUT1 in systemic Glut1 haploinsufficient mice. Single-compartment restoration produced partial benefit, whereas dual-compartment restoration more robustly improved cerebrospinal fluid glucose availability and cognitive function. These findings indicate that endothelial GLUT1 restoration alone is insufficient for robust rescue and redefine GLUT1-DS as a multicellular disorder of the neurovascular unit.

neuroscience↗

bioRxiv2022

Targeting A-Kinase Anchoring Protein 12 Phosphorylation in Hepatic Stellate Cells Regulates Liver Injury and Fibrosis in Mouse Models

Trans-differentiation of hepatic stellate cells (HSCs) to activated state potentiates liver fibrosis through release of extracellular matrix (ECM) components, distorting the liver architecture. Since limited antifibrotics are available, pharmacological intervention targeting activated HSCs may be considered for therapy. A-kinase anchoring protein 12 (AKAP12) is a scaffolding protein that directs protein kinases A/C (PKA/PKC) and cyclins to specific locations spatiotemporally controlling their biological effects. It has been shown that AKAP12s scaffolding functions are altered by phosphorylation. In previously published work, observed an association between AKAP12 phosphorylation and HSC activation. In this work we demonstrate that AKAP12s scaffolding activity towards the endoplasmic reticulum (ER)-resident collagen chaperone, heat-shock protein 47 (HSP47) is strongly inhibited by AKAP12s site-specific phosphorylation in activated HSCs. CRISPR-directed gene editing of AKAP12s phospho- sites restores its scaffolding towards HSP47, inhibiting HSP47s collagen maturation functions and HSC activation. AKAP12 phospho-editing dramatically inhibits fibrosis, ER stress response, HSC inflammatory signaling and liver injury in mice. Our overall findings suggest a pro-fibrogenic role of AKAP12 phosphorylation that may be targeted for therapeutic intervention in liver fibrosis.

cell biology↗

bioRxiv2020

Modeling alcoholic liver disease in a human Liver-Chip

Fatty liver disease (FLD), is a major public health burden that affects up to 30% of people in Western countries and leads to progressive liver injury, comorbidities, and increased mortality. Key risk factors for developing FLD are obesity and alcohol consumption, both of which are growing in prevalence worldwide. There is an urgent need for human-relevant preclinical models to improve our understanding of FLD progression to steatohepatitis and for the development of sensitive noninvasive diagnostics and therapies. Alcohol-induced liver disease (ALD) represents an ideal case for modeling FDL as ethanol exposure is a comparatively simpler trigger for experimental induction of the pathology, as opposed to the complexity of modeling the diet- and life-style induced FLD. Further, despite their different root causes, the two pathologies share several common characteristics in disease progression and deterioration of liver function, highlighting the potential of an ALD microphysiological model for broad application in translational research. Here, we leverage our recently reported human Liver-Chip for toxicity applications, to expand the capabilities of the platform for broad application in translational research. We report the first in vitro modeling of ALD that uses human relevant blood alcohol concentrations (BAC) and affords multimodal profiling of clinically relevant endpoints. Our ALD Liver-Chip recapitulates established FLD markers in response to ethanol in a concentration-dependent manner, including lipid accumulation and oxidative stress. Importantly, we show that the ALD Liver-Chip supports the study of secondary insults common in patients with advanced ALD, such as high blood endotoxin levels due to alcohol-associated increased intestinal permeability and barrier dysfunction. Moreover, owing to new developments in the design, the ALD Liver-Chip enables the measurement of structural changes of the bile canaliculi (BC) network as a novel in vitro quantitative readout of alcoholic liver toxicity. In summary, we report the development of a human ALD Liver-Chip as a new platform for modeling the progression of alcohol-induced liver injury with direct translation to clinical research.

bioengineering↗