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.
Subject(s)
Cytokines/metabolism , Granulocyte Colony-Stimulating Factor/metabolism , Lacticaseibacillus rhamnosus/physiology , Placenta/cytology , Placenta/metabolism , Trophoblasts/metabolism , Female , Gene Expression Regulation/physiology , Granulocyte Colony-Stimulating Factor/genetics , Humans , Janus Kinases/genetics , Janus Kinases/metabolism , Lacticaseibacillus rhamnosus/classification , Male , Mitogen-Activated Protein Kinase Kinases/genetics , Mitogen-Activated Protein Kinase Kinases/metabolism , Pregnancy , Probiotics/pharmacology , STAT Transcription Factors/genetics , STAT Transcription Factors/metabolism , Sex Characteristics , Signal Transduction , Trophoblasts/cytologyABSTRACT
Intrauterine infection/inflammation complicates 25% to 40% of preterm births (PTB). The human vagina is normally populated by Lactobacillus species, some of which upregulate interleukin 10 (IL-10) output in lipopolysaccharide (LPS)-treated human placental trophoblast cells. We hypothesize that a probiotic strain, L rhamnosus GR-1 exerts its anti-inflammatory effect through activation of the Janus Kinases/Signal Transducers and Activators of Transcription (JAK/STAT) and mitogen-activated protein kinase (MAPK) pathways. Placental trophoblasts from term healthy pregnancies were treated with LPS in the presence or absence of pretreatments with GR-1 supernatant and/or chemical inhibitors of the intracellular signaling pathways. Phosphorylation of STAT3 and p38 was measured by Western Blot analysis, and output of IL-10 was determined by enzyme-linked immunosorbent assay (ELISA). Phosphorylation of STAT-3 and p38 was upregulated by GR-1 supernatant alone or in combination with LPS, while IL-10 output was inhibited by both JAK and p38 inhibitors. These data provide an underlying intracellular mechanism for cytokine regulation in the human placenta by L rhamnosus GR-1 and potential prevention of infection/inflammation-mediated PTB.
