Extracellular galectin-3 counteracts adhesion and exhibits chemoattraction in Helicobacter pylori-infected gastric cancer cells.
Galectin-3 (Gal-3) is a β-galactoside lectin that is upregulated and rapidly secreted by gastric epithelial cells in response to Helicobacter pylori infection. An earlier study reported the involvement of H. pylori cytotoxin-associated gene A (cagA) in the expression of intracellular Gal-3. However, the role of extracellular Gal-3 and its functional significance in H. pylori-infected cells remains uncharacterized. Data presented here demonstrate secretion of Gal-3 is an initial host response event in gastric epithelial cells during H. pylori infection and is independent of CagA. Previously, Gal-3 was shown to bind to H. pylori LPS. The present study elaborates the significance of this binding, as extracellular recombinant Gal-3 (rGal-3) was shown to inhibit the adhesion of H. pylori to the gastric epithelial cells. Interestingly, a decrease in H. pylori adhesion to host cells also resulted in a decrease in apoptosis. Furthermore, the study also demonstrated a chemoattractant role of extracellular rGal-3 in the recruitment of THP-1 monocytes. This study outlines the previously unidentified roles of extracellular Gal-3 where it acts as a negative regulator of H. pylori adhesion and apoptosis in gastric epithelial cells, and as a chemoattractant to THP-1 monocytes. Our findings could contribute to the better understanding of how Gal-3 acts as a modulator under H. pylori-induced pathological conditions.
Cancer Science Institute of Singapore, National University of Singapore, Singapore.|Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
Vinod Vijay
VV
Subhash
Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
Samantha Shi Min
SSM
Ling
Department of Microbiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
Bow
B
Ho
D000942:Antigens, Bacterial / Q000235:genetics / Q000378:metabolism*; D017209:Apoptosis / Q000502:physiology; D001422:Bacterial Adhesion / Q000502:physiology*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D002633:Chemotaxis / Q000502:physiology*; D004847:Epithelial Cells / Q000382:microbiology*; D037502:Galectin 3 / Q000378:metabolism*; D016481:Helicobacter Infections / Q000473:pathology; D016480:Helicobacter pylori / Q000378:metabolism*; D006801:Humans; D013274:Stomach Neoplasms / Q000473:pathology
D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D037502:Galectin 3; C080866:cagA protein, Helicobacter pylori