The Expression and Cellular Localization of Galectin-1 and Galectin-3 in the Fallopian Tube Are Altered in Women with Tubal Ectopic Pregnancy

Abstract

Galectin-1 and galectin-3 are abundantly expressed at implantation sites in the uterus, suggesting their involvement in the establishment of pregnancy. In this study, we examined the expression and localization of galectin-1 and galectin-3 in fallopian tubes from nonpregnant women, and in those presenting with tubal ectopic pregnancy. There was no significant difference in the expression of either galectin-1 (LGALS1) or galectin-3 (LGALS3) transcripts in the fallopian tube across the menstrual cycle. Their expressions in the fallopian tube were inversely correlated to each other (r = −0.5134, p < 0.0001) and differentially localized. Galectin-1 protein was abundant in the stroma of nonpregnant fallopian tubes, whereas galectin-3 was mainly localized to the epithelium, notably to the cilia of ciliated cells and the apical cytoplasm of secretory cells. In ectopic pregnancies, LGALS3 expression was significantly reduced (p < 0.0001), but LGALS1 expression did not change when compared to nonpregnant fallopian tubes collected during the mid-secretory phase. The percentage of fallopian tube epithelial cells expressing galectin-3 in cilia tended to be reduced (p = 0.0685), with an accompanying loss of a normal ciliary structure, while nuclear galectin-3 increased (p < 0.05) in ectopic pregnancies. Epithelial immunostaining for galectin-1 tended to be elevated in fallopian tubes from women with ectopic pregnancy. Coculture of human trophoblast origin SW71 cells significantly increased LGALS1 expression in human fallopian tube epithelial OE-E6/E7 cells, suggesting that trophoblast-derived products regulate LGALS1 expression in the oviductal epithelium. These findings imply a differential contribution of galectin-1 and galectin-3 in the homeostasis of human fallopian tubes and in the pathophysiology of ectopic pregnancy.

Cigarette smoking alters sialylation in the Fallopian tube of women, with implications for the pathogenesis of ectopic pregnancy

“…Galectin‐1 and ‐3 are β ‐galactoside‐binding animal lectins with a high affinity for lactosamine residues (Gal β 1,3/4GlcNAc). Galectins are expressed at implantation sites, suggesting their involvement in the establishment of pregnancy (Nio‐Kobayashi et al, ). Galectin‐1 expression increased in cases of ectopic implantation, and trophoblast‐derived molecules enhanced epithelial galectin‐1 expression (Nio‐Kobayashi et al, ).…”

“…Galectins are expressed at implantation sites, suggesting their involvement in the establishment of pregnancy (Nio‐Kobayashi et al, ). Galectin‐1 expression increased in cases of ectopic implantation, and trophoblast‐derived molecules enhanced epithelial galectin‐1 expression (Nio‐Kobayashi et al, ). The sugar‐binding affinity for galectin‐1 is blocked by α2,6‐sialylation on terminal galactose, which is the product of ST6GAL1 activity.…”

“…The menstrual phase of each non‐pregnant patient at the time of hysterectomy was determined by histologic examination and staging of an endometrial biopsy taken with the Fallopian tube and by measurement of serum estradiol and progesterone levels, as described previously (Duncan et al, ). Fallopian tube samples from ectopic pregnancies were confirmed to be free of trophoblast contamination, as described previously (Nio‐Kobayashi et al, ). Patients were identified as smokers or non‐smokers based on patient history combined with assessment of serum cotinine concentration, which is greater than 100 ng/mL in women with a smoking history but is negligible in non‐smokers (Horne et al, ).…”

“…α2,6‐sialylation on a terminal galactose inhibits galectin‐1 binding, whereas sialyation has no effect on the binding of galectin‐3. We recently reported that expression and localization of galectin‐1 and galectin‐3 are altered (galectin‐1 increases whereas galectin‐3 decreases) in the Fallopian tube of women with ectopic implantation (Nio‐Kobayashi et al, ). This relationship suggests the involvement of lectin–glycoconjugate interactions, especially galectin‐1‐glycoconjugate binding, during the pathogenesis of ectopic implantation—although the glycoconjugate targets for galectins and their functions during normal and pathological implantation are still unclear.…”

Galectins in the Pathogenesis of Cerebrovascular Accidents: An Overview

“…49 Galectin-3 is expressed in the plasma membrane of various cells and in the cilia of ciliated epithelial cells. 47,50,51 Galectin-3 is secreted by cells and has been found to have intracellular and extracellular functions in modulating the immune response. 52 Galectin-2 is secreted by multiple cells in the gastrointestinal tract and has been determined to be a part of the detergent resistant portion of the enterocyte brush border membrane.…”