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Petrovic, S.

Publications and source records attributed to Petrovic, S..

3 recordsLinked to original sources
bioRxiv2026

Galectin-1 Modulates Cell Adhesions, Caveolae, and Vascular Permeability in Kidney Endothelial Cells -- Insights from Proteomics, Phosphoproteomics, and Functional Studies

Microvascular inflammation and endothelial injury, triggered by interferon-gamma (IFN{gamma}), are hallmarks of antibody-mediated rejection (ABMR), the leading cause of premature kidney allograft loss. Glomerular extracellular matrix (ECM) remodeling and endothelial caveolae formation are important aspects of chronic ABMR. We found galectin-1, an immunomodulatory protein that interacts with the ECM, to be increased in the glomeruli of patients with ABMR, while its gene (LGALS1) expression was decreased by IFN{gamma} stimulation in glomerular endothelial cells. Mechanisms underlying endothelial dysfunction in ABMR, its links to ECM remodeling, and the role of immunomodulatory proteins such as galectin-1 remain incompletely understood. Here we studied the effects of galectin-1 modulation in glomerular microvascular endothelial cells (GMECs) in vitro. We demonstrated that galectin-1 was mainly expressed by glomerular endothelial cells in ABMR kidneys. To model key aspects of endothelial injury in ABMR, we knocked down LGALS1 in GMECs, followed by stimulation with IFN{gamma} and performed label-free quantitative proteomic and phosphoproteomic profiling of GMECs. Proteomic analysis identified 5446 proteins (FDR<0.01), of which 236, 827, and 267 were differentially expressed in response to LGALS1 knockdown, IFN{gamma} treatment, and their interaction, respectively (FDR<0.05). Both LGALS1 knockdown and the interaction between treatments significantly altered expression of adhesion proteins (FDR<0.01), particularly integrin subunit {beta}5, which was validated. Phosphoproteomic profiling identified 2727 phosphopeptides (FDR<0.01), with 28 that were differentially expressed across LGALS1 knockdown, IFN{gamma} treatment, and their interaction (P<0.01). Phosphorylation of CAVN1 and co-localization with its partner CAV1, critical for caveolar formation, were decreased in GMECs upon LGALS1 knockdown, IFN{gamma} stimulation, or both. In a microfluidic model of the glomerular microvasculature, addition of recombinant galectin-1 increased both endothelial permeability and secretion of proinflammatory cytokines, in LGALS1-silenced GMECs. Thus, endothelial signaling pathways regulated by inflammatory cues and galectin-1 contribute to endothelial injury and caveolae formation, highlighting galectin-1 as a potential therapeutic target in ABMR. SynopsisGalectin-1 is expressed by kidney glomerular endothelium. This study reveals that modifying galectin-1 in endothelial cells, in the presence of IFN{gamma} perturbs cytoskeletal, adhesion and caveolar proteins resulting in altered endothelial permeability. O_LILGALS1 knockdown increased ECM proteins and decreased interferon-induced proteins. C_LIO_LILGALS1 knockdown and IFN{gamma} treatment perturbed cell adhesion proteins such as ITGB5. C_LIO_LICAVN1 phosphorylation and colocalization with CAV1 decreased upon LGALS1 knockdown. C_LIO_LIExtracellular galectin-1 increased microvascular permeability in response to IFN{gamma}. C_LI

cell biology↗
bioRxiv2021

Architecture of the cytoplasmic face of the nuclear pore

The nuclear pore complex (NPC) is the sole bidirectional gateway for nucleocytoplasmic transport. Despite recent progress in elucidating the NPC symmetric core architecture, the asymmetrically decorated cytoplasmic face, essential for mRNA export and a hotspot for nucleoporin-associated diseases, has remained elusive. Here, we report a composite structure of the entire human cytoplasmic face obtained by combining biochemical reconstitution, crystal structure determination, docking into cryo-electron tomographic reconstructions, and physiological validation, accounting for a third of the NPCs mass. Whereas an evolutionarily conserved [~]540 kDa hetero-hexameric cytoplasmic filament nucleoporin complex is anchored by species-specific motifs above the central transport channel, attachment of the pentameric NUP358 bundles depends on the double-ring arrangement of the coat nucleoporin complex. Our results and the predictive power of our composite structure provide a rich foundation for elucidating the molecular basis of mRNA export and nucleoporin diseases. One sentence summaryAn interdisciplinary analysis established the near-atomic molecular architecture of the cytoplasmic face of the human nuclear pore complex.

biochemistry↗
bioRxiv2021

Architecture of the linker-scaffold in the nuclear pore

The nuclear pore complex (NPC) is the sole bidirectional gateway for nucleocytoplasmic transport. Despite recent progress in elucidating the arrangement of the structured scaffold building blocks in the NPC symmetric core, their cohesion by multivalent unstructured linker proteins remained elusive. Combining biochemical reconstitution, high resolution structure determination, docking into cryo-electron tomographic reconstructions, and physiological validation, we elucidated the architecture of the entire linker-scaffold, yielding a near-atomic composite structure of the symmetric core accounting for [~]77 MDa of the human NPC. Whereas linkers generally play a rigidifying role, the linker-scaffold of the NPC provides the plasticity and robustness necessary for the reversible constriction and dilation of its central transport channel. Our results complete the structural characterization of the NPC symmetric core, providing a rich foundation for future functional studies. One sentence summaryAn interdisciplinary analysis established the near-atomic molecular architecture and evolutionary conservation of the linker-scaffold of the human nuclear pore complex.

biochemistry↗