Biology subjects

Ngo, T. T. T.

Publications and source records attributed to Ngo, T. T. T..

3 recordsLinked to original sources

bioRxiv2026

A multiverse analysis of stomach-brain coupling in humans

The gastric-brain axis is a burgeoning field of neuroscience; however, inferences from neuroimaging research are often constrained by the high dimensionality of methodological choices potentially leading to disparate outcomes. This study addresses such concerns by performing a multiverse analysis of gastric-brain coupling in humans. We systematically evaluated 1,728 unique analytic pipelines using electroencephalography (EEG) and electrogastrography (EGG) data to quantify the robustness of observed gastric-brain coupling. Our results reveal that whilst analytic decisions influence the magnitude of observed coupling, at the group level the phenomenon remains relatively robust across the parameter space. High inter-individual variance can, however, be observed. Coupling was observed in the alpha, theta, and beta bands, with the latter two bands showing robust coupling across the largest number of electrodes. Robust coupling across frequency bands was primarily seen in medial electrodes, with some left lateral coupling also observed. Overall, these findings suggest that gastric-brain coupling is likely to be a robust physiological feature in healthy participants, providing a stable foundation for future studies.

neuroscience↗

bioRxiv2025

Perilysosomal Ca2+ overload impairs autophagic degradation in β-cell lipotoxicity

Saturated fatty acids impose lipotoxic stress on pancreatic {beta}-cells, leading to {beta}-cell failure and diabetes. In this study, we investigate the critical role of organellar Ca2+ disturbance on defective autophagy and {beta}-cell lipotoxicity. Palmitate, a saturated fatty acid, induced perilysosomal Ca2+ elevation, sustained mTORC1 activation on the lysosomal membrane, suppression of the lysosomal transient receptor potential mucolipin 1 (TRPML1) channel, and accumulation of undigested autophagosomes in {beta}-cells. These Ca2+ aberrations with autophagy defects by palmitate were prevented by a mTORC1 inhibitor or a mitochondrial superoxide scavenger. To alleviate perilysosomal Ca2+ overload, strategies such as lowering extracellular Ca2+, employing voltage-gated Ca2+ channel blocker or ATP-sensitive K+ channel opener effectively abrogated mTORC1 activation and preserved autophagy. Furthermore, redirecting perilysosomal Ca2+ into the endoplasmic reticulum (ER) with an ER Ca2+ ATPase activator, restores TRPML1 activity, promotes autophagic flux, and improves survival of {beta}-cells exposed to palmitate-induced lipotoxicity. Our findings suggest oxidative stress-Ca2+ overload-mTORC1 pathway involves in TRPML1 suppression and defective autophagy during {beta}-cell lipotoxicity. Restoring perilysosomal Ca2+ homeostasis emerges as a promising therapeutic strategy for metabolic diseases.

physiology↗

bioRxiv2023

Homologous recombination contributes to the repair of acetaldehyde-induced DNA damages.

Acetaldehyde, a chemical that can cause DNA damage and contribute to cancer, is prevalently present in our environment, e.g., in alcohol, tobacco, and food. Although aldehyde potentially promotes crosslinking reaction among biological substances including DNA, RNA, and proteins, it remains unclear what types of DNA damage are caused by acetaldehyde and how they are repaired. In this study, we examined acetaldehyde sensitivity of DNA damage-deficient cells established from human TK6 cell line. Among the mutants, mismatch repair mutants did not show a hypersensitivity to acetaldehyde, while cells deficient in base and nucleotide excision repair pathways increased its sensitivity. We found a delayed repair and hypersensitivity in homologous recombination (HR)-deficient cells but not in non-homologous end joining-deficient cells after acetaldehyde treatment. By analyzing the formation of acetaldehyde-induced RAD51 foci, which represent HR intermediates, HR-deficient cells, but not NHEJ, exhibits delayed repair of acetaldehyde-induced DNA damages, compared with wild-type. These results suggest that acetaldehyde causes complex DNA damages that requires various types of repair pathways. Interestingly, mutants deficient in TDP1 and TDP2, which are involved in the removal of protein adducts from DNA ends, exhibited hypersensitivity to acetaldehyde. the acetaldehyde sensitivity of the TDP1-/-/RAD54-/- double mutant was similar to that of each single mutant. This epistatic relationship between TDP1 and RAD54 suggests that that the removal of protein-DNA adducts generated by acetaldehyde needs to be removed for efficient repair by HR. Our study would help understand the molecular mechanism of genotoxic and mutagenic effects of acetaldehyde.

molecular biology↗