Lactobacillus rhamnosus GR-1 Stimulates Colony-Stimulating Factor 3 (Granulocyte) (CSF3) Output in Placental Trophoblast Cells in a Fetal Sex-Dependent Manner1

Abstract

Bacterial vaginosis is associated with a 1.4-fold increased risk of preterm birth. We have shown previously that Lactobacillus rhamnosus GR-1 supernatant up-regulates interleukin 10 and down-regulates tumor necrosis factor-alpha output in lipopolysaccharide (LPS)-treated human primary placenta cultures in a fetal sex-dependent manner. We hypothesize that lactobacilli also exert their anti-inflammatory effect by up-regulation of colony-stimulating factor 3 (granulocyte) (CSF3), which is secreted from both immune and placental trophoblast cells, and that this activity is dependent on the sex of the fetus. Placental trophoblast cells were isolated from term elective cesarean section placentae using a Percoll gradient and separated from CD45(+) cells using magnetic purification. Cells were treated with LPS in the presence or absence of pretreatments with L. rhamnosus GR-1 supernatant or chemical inhibitors of the intracellular signaling pathways. Phosphorylations of mitogen-activated protein kinase 14 (MAPK14, previously known as p38) and signal transducer and activator of transcription (STAT) 3 were measured by Western blot analysis, and levels of CSF3 were determined by ELISA. CSF3 output was increased only in the placental trophoblast cells of female fetuses treated with LPS, GR-1 supernatant, and a combination of both treatments. The GR-1 supernatant up-regulated the phosphorylation of STAT3 and MAPK14. CSF3 output was inhibited by both Janus kinases (JAK) and MAPK14 inhibitors. None of the treatments was able to increase CSF3 output in either the pure trophoblast or the CD45(+) cell preparations alone. These results suggest an underlying mechanism for the sex difference in incidence of preterm birth and provide potential evidence for a therapeutic benefit of lactobacilli in reducing the risk of preterm labor.

“Trophoblast islands of the chorionic connective tissue” (TICCT): A novel placental histologic feature

“…Other studies have also shown evidence of sexual dimorphism in the biology of the placenta. Yeganegi et al have demonstrated that the key cytokine response of placental trophoblasts to lipopolysaccharide or endotoxin was greater in male fetuses [51], and that up-regulation of colony-stimulating factor 3 (CSF3) in trophoblasts by Lactobacillus rhamnosus GR-1 was detected only in trophoblasts obtained from placentas of female fetuses [52]. Murphy et al have shown that placental 11β-hydroxysteroid dehydrogenase activity differs between male and female fetuses in humans [53].…”

The Rationale for Probiotics Improving Reproductive Health and Pregnancy Outcome

“…For example, there is a strong association between elective preterm delivery (usually undertaken because of growth restriction or preeclampsia) and ischemic heart disease. 57 It should be noted that probiotics have not been proven clinically to reduce the risk of these complications in pregnancy, but as presented in Table I, 46,[58][59][60][61][62][63][64][65][66][67][68][69][70][71][72] there are a number of attributes of these organisms that could play a role.…”

Evidence of sexual dimorphism in the placental function with severe preeclampsia

“…Changes in diet provide distinctive signature of sexually dimorphic genes in placenta with expression generally higher in female than male placentas (9). The male placenta has higher TLR4 expression and a greater production of TNFα in response to LPS than the female placenta, which may underlie the propensity to preterm birth in males (10). …”