1. Galectin-3 Induces a Pro-degradative/inflammatory Gene Signature in Human Chondrocytes, Teaming Up with Galectin-1 in Osteoarthritis Pathogenesis.
- Author
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Weinmann D, Schlangen K, André S, Schmidt S, Walzer SM, Kubista B, Windhager R, Toegel S, and Gabius HJ
- Subjects
- Aged, Aged, 80 and over, Blood Proteins, Chondrocytes pathology, Extracellular Matrix metabolism, Female, Galectins, Gene Expression Profiling methods, Gene Expression Regulation, Humans, Male, Middle Aged, Oligonucleotide Array Sequence Analysis methods, Osteoarthritis genetics, Osteoarthritis immunology, Signal Transduction, Chondrocytes metabolism, Galectin 1 metabolism, Galectin 3 metabolism, Gene Regulatory Networks, Osteoarthritis pathology
- Abstract
Inflammatory chemo- and cytokines and matrix-degrading proteases underlie the progression of osteoarthritis (OA). Aiming to define upstream regulators for these disease markers, we pursued initial evidence for an upregulation of members of the adhesion/growth-regulatory galectin family. Immunohistochemical localization of galectin-3 (Gal-3) in sections of human cartilage with increasing levels of degeneration revealed a linear correlation reaching a chondrocyte positivity of 60%. Presence in situ was cytoplasmic, the lectin was secreted from OA chondrocytes in culture and binding of Gal-3 yielded lactose-inhibitable surface staining. Exposure of cells to the lectin led to enhanced gene expression and secretion of functional disease markers. Genome-wide transcriptomic analysis broadened this result to reveal a pro-degradative/inflammatory gene signature under the control of NF-κB. Fittingly, targeting this route of activation by inhibitors impaired the unfavourable response to Gal-3 binding, as also seen by shortening the lectin's collagen-like repeat region. Gal-3's activation profile overlaps with that of homodimeric galectin-1 (Gal-1) and also has distinctive (supplementing) features. Tested at subsaturating concentrations in a mixture, we found cooperation between the two galectins, apparently able to team up to promote OA pathogenesis. In summary, our results suggest that a network of endogenous lectins is relevant for initiating this process cascade.
- Published
- 2016
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