PSIX-13 - Activation of cell signaling pathways by Galectins in cow blood

Abstract: Galectins are part of a conserved family of β-galactoside-binding proteins that contribute to critical biological events during mammalian gestation and increasingly recognized for a possible role in the immune response of the cow. The objective of this study was to evaluate the effect of Galectins on signal transduction and cell activation in cow blood. Whole blood was collected aseptically from the jugular vein of healthy Holstein Friesian dairy cows (N=3). Blood samples (2.5ml) in duplicate were treated with 150µl of the four different type of recombinant galectins (1, 3, 4, and 9) respectively and untreated samples were served as control. The concentration of total plasma protein was determined using the Pierce BCA kit. Protein expression profiling was performed using1,358 antibodies on the Full Moon BioSystems’ Signaling Explorer antibody array covering 20 cell signaling pathways, as recommended by the manufacturer using an Agilent microarray scanner. Data normalization was performed using GeneSpring GX software to generate fold changes in gene expression and then filtered to obtain a list of significantly upregulated and downregulated genes. Features were extracted from protein array images of samples treated with Galectin 1, 3, 4, 9, and untreated sample as a control group. Treatment with all four Galectins increased the concentration of total plasma protein. Average increases due to treatment with Gal1, Gal3, Gal4, and Gal9 were 27%, 10%, 20%, and 14% respectively. ANOVA test showed significance difference among the groups (p < 0.05). Dunnett option was used to compare each of the treated samples to the control group as a baseline. The results also showed that there was significant difference between the control group and any of the treated group (p < 0.05). Distinct signaling pathways are activated in response to Galectin exposure. Further studies are needed to define their regulation and functional impact on cow health.