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Biology subjects

Kang, J.-Q.

Publications and source records attributed to Kang, J.-Q..

3 recordsLinked to original sources

Accumulation of Extracellular GABA, Impaired GABAergic Neurotransmission and 4-Phenylbutyrate Rescue in Mice of SLC6A1 Variant-Mediated Disorders

Mutations in SLC6A1 encoding GABA transporter 1 are a leading monogenic cause of developmental and epileptic encephalopathies, severe neurodevelopmental disorders lacking effective treatments. We previously demonstrated that 4-phenylbutyrate restored molecular and functional deficits, and reduced seizures in a Slc6a1 loss-of-function mouse, motivating a promising ongoing clinical trial. Here, we show this mouse exhibits accumulation of extracellular GABA, impaired neurotransmission, and reduced GABA uptake; and demonstrate that 4-phenylbutyrate rescues these abnormalities.

neuroscience↗

TrimNN: Characterizing cellular community motifs for studying multicellular topological organization in complex tissues

The spatial organization of cells plays a pivotal role in shaping tissue functions and phenotypes in various biological systems and diseased microenvironments. However, the topological principles governing interactions among cell types within spatial patterns remain poorly understood. Here, we present the Triangulation Cellular Community Motif Neural Network (TrimNN), a graph-based deep learning framework designed to identify conserved spatial cell organization patterns, termed Cellular Community (CC) motifs, from spatial transcriptomics and proteomics data. TrimNN employs a semi-divide-and-conquer approach to efficiently detect over-represented topological motifs of varying sizes in a triangulated space. By uncovering CC motifs, TrimNN reveals key associations between spatially distributed cell-type patterns and diverse phenotypes. These insights provide a foundation for understanding biological and disease mechanisms and offer potential biomarkers for diagnosis and therapeutic interventions.

bioinformatics↗

GABRA1 frameshift variants impair GABAA receptor proteostasis

The gamma-aminobutyric acid type A receptor (GABAAR) is the most common inhibitory neurotransmitter-gated ion channel in the central nervous system. Pathogenic variants in genes encoding GABAAR subunits can cause receptor dysfunction and lead to genetic epilepsy. Frameshift variants in these genes can result in a premature termination codon, producing truncated receptor subunit variants. However, the pathogenic molecular mechanism as well as functional implications of these frameshift variants remains inadequately characterized. This study focused on four clinical frameshift variants of the 1 subunit of GABAAR (encoded by the GABRA1 gene): K401fs (c.1200del), S326fs (c.975del), V290fs (c.869_888del), and F272fs (c.813del). These variants result in the loss of one to three transmembrane helices, whereas wild type 1 has four transmembrane helices. Therefore, these variants serve as valuable models to evaluate membrane protein biogenesis and proteostasis deficiencies of GABAARs. In HEK293T cells, all four frameshift variants exhibit significantly reduced trafficking to the cell surface, resulting in essentially non-functional ion channels. However, the severity of proteostasis deficiency varied among these four frameshift variants, presumably due to their specific transmembrane domain deletions. The variant 1subunits exhibited endoplasmic reticulum (ER) retention and activated the unfolded protein response (UPR) to varying extents. Our findings revealed that these frameshift variants of GABRA1 utilize overlapping yet distinct molecular mechanisms to impair proteostasis, providing insights into the pathogenesis of GABAAR-associated epilepsy.

cell biology↗