Archives of biochemistry and biophysics最新文献

Preeclampsia (PE) is a pregnancy complication that poses a major risk to both the maternal and the fetal's safety. By studying the role and mechanism of LncRNA SNHG15 in preeclampsia pathogenesis, this study aimed to better understand the pathophysiology and prevention of PE. Placental samples and hypoxic trophoblast cell line--HTR8/SVneo were analyzed using qPCR to determine the differential expression of LncRNA SNHG15. Nuclear-cytoplasmic fractionation assays confirmed that LncRNA SNHG15 is predominantly localized in the cytoplasm of HTR8/SVneo cells, where it modulates cellular functions including proliferation, migration, and invasion. Using a dual luciferase reporter assay and rescue experiment, functions of miRNA-451a and LncRNA SNHG15 in HTR8/SVneo cells were examined. ATF2 expression levels in the hypoxic cell model and after LncRNA SNHG15 and miR-451a interference were confirmed by qPCR and Western blot. Evidence from this study indicates that LncRNA SNHG15 may be involved in the onset of preeclampsia, suggesting its viability as a novel treatment target.

Alpha-1 Antitrypsin (AAT) is a serine protease inhibitor that protects lung tissue by neutralizing neutrophil elastase. Galectin-8 (Gal-8) is a tandem-repeat galectin with N- and C-terminal carbohydrate recognition domains (CRDs) that bind β-galactoside-containing N-glycans. Both proteins co-localize in pulmonary and circulatory systems, suggesting a physiological interaction. Here, we demonstrate a glycan-dependent binding between Gal-8 and AAT using pull-down assays, mass spectrometry, isothermal titration calorimetry, and size-exclusion chromatography. Importantly, binding of Gal-8 impairs AAT's protease inhibitory activity, with the N-terminal CRD of Gal-8 sufficient to disrupt AAT function. Kinetic analyses show that Gal-8 inhibits AAT and enhances trypsin activity, as evidenced by a decrease in K_m and an increase in catalytic efficiency (k_cat/K_m). In cell assays, Gal-8 restored trypsin-mediated proteolysis and induced cell detachment in HeLa and CHO cells despite AAT presence, confirming biological relevance. Leveraging this interaction, we developed a lactose-mediated elution method to purify AAT from human and bovine serum using Gal-8 immobilized on Ni-NTA beads. Moreover, a stable CHO cell line expressing recombinant AAT (∼2 g/L) exhibited glycosylation comparable to serum AAT and retained Gal-8 binding. Our findings reveal Gal-8 as a novel modulator of AAT activity and present a glycan-specific strategy for AAT purification, with implications for biotherapeutic production and quality control.

β-Galactosidase is a lysosomal enzyme whose deficiency is associated with genetic disorders such as GM1 gangliosidosis, prompting the search for novel enzyme modulators with therapeutic potential. The current study evaluated the inhibitory potential of selected natural polyphenols against β-galactosidase using a combined approach of biochemical assays and computational modeling. Sixteen plant-derived compounds were initially screened through molecular docking against Aspergillus oryzae β-galactosidase. Among these, hesperidin, rutin, and chlorogenic acid exhibited the most favorable interactions and were subsequently assessed through in vitro enzyme inhibition assays and MM/GBSA binding energy calculations. These compounds showed potential inhibitory effects and stable binding within the enzyme's active site. Although classical pharmacological chaperone activity was not directly demonstrated, the observed modulation of enzyme function suggests potential for further development of these polyphenols as structurally distinct β-galactosidase inhibitors. The findings provide a basis for future investigations aimed at natural product-based strategies to manage lysosomal storage disorders such as GM1 gangliosidosis.