Simulating cellular galectin networks by mixing galectins in vitro reveals synergistic activity

Background

Even though members of the family of adhesion/growth-regulatory galectins are increasingly detected to be co-expressed, they are still being routinely tested separately. The recent discovery of heterodimer formation among galectins-1, -3, and -7 in mixtures prompts further study of their functional activities in mixtures.

Methods

Cell agglutination, galectin binding to cells, as well as effects on cell proliferation, onset of apoptosis and migration were determined in assays using various cell types and mixtures of galectins-1, -3, and -7.

Results

Evidence for a more than additive increases of experimental parameters was consistently obtained.

Conclusion

Testing galectins in mixtures simulates the situation of co-expression in situ and reveals unsuspected over-additive activities. This new insight is relevant for analyzing galectin functionality in (patho)physiological conditions.

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Galectins-1, -3, and -7 form heterodimers in solution.

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Mixtures of galectins simulates galectin co-expression in situ.

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Mixtures display synergistic activities in vitro.

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Cell agglutination, apoptosis, proliferation, migration affected.

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Findings are relevant for galectin functionality in vivo.

Galectin-3 Inhibition With Modified Citrus Pectin in Hypertension

We investigated the effect of galectin-3 (Gal-3) inhibition with modified citrus pectin on markers of collagen metabolism in a proof-of-concept randomized placebo-controlled trial of participants with elevated Gal-3 levels and hypertension. Although higher Gal-3 levels were associated with female sex, diabetes, and reduced glomerular filtration rate in cross-sectional analyses, treatment with modified citrus pectin did not change collagen markers. The effect of Gal-3 inhibition among individuals with heart failure warrants further investigation.

Acute Kidney Injury Induces Remote Cardiac Damage and Dysfunction Through the Galectin-3 Pathway

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In 2 different mouse models, AKI increased Gal-3 expression and induced cardiac dysfunction, cardiac and systemic inflammation, cardiac macrophage infiltration, and fibrosis.

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Cardiac consequences of AKI were dependent on the Gal-3 pathway and were prevented using Gal-3 knockout mice or modified citrus pectin as a pharmaceutical inhibitor.

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Cardiac Gal-3 expression resulted from bone marrow-derived immune cells recruitment after AKI.

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In critically ill patients, development of AKI is associated with increased plasma Gal-3 levels and increased biomarkers of cardiac injury and damage.

Acute kidney injury is associated with increased risk of heart failure and mortality. This study demonstrates that acute kidney injury induces remote cardiac dysfunction, damage, injury, and fibrosis via a galectin-3 (Gal-3) dependent pathway. Gal-3 originates from bone marrow-derived immune cells. Cardiac damage could be prevented by blocking this pathway.