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. 2014 Sep;18(9):1816-29.
doi: 10.1111/jcmm.12307. Epub 2014 Jun 4.

Inhibition of infection-mediated preterm birth by administration of broad spectrum chemokine inhibitor in mice

Oksana Shynlova  1 , Anna Dorogin, Yunqing Li, Stephen Lye
Affiliations

Inhibition of infection-mediated preterm birth by administration of broad spectrum chemokine inhibitor in mice

Oksana Shynlova et al. J Cell Mol Med. 2014 Sep.

Abstract

Preterm birth (PTB) is the single most important cause of perinatal and infant mortality worldwide. Maternal infection can result in PTB. We investigated the ability of a Broad Spectrum Chemokine Inhibitor (BSCI) to prevent infection-induced PTB in mice. PTB was initiated in pregnant mice by intraperitoneal injection of lipopolysaccharide (LPS; 50 μg). Half the mice received BSCI (10 mg/kg) 24 hrs prior to and immediately before LPS administration. The impact of LPS alone or LPS plus BSCI was assessed on (i) injection-to-delivery interval, foetal survival rate, placental and neonates' weight; (ii) amniotic fluid and maternal plasma cytokine levels (by Luminex assay); foetal and maternal tissue cytokine gene expression levels (by Real-Time RT-PCR); (iii) immune cells infiltration into the uterine tissue (by stereological immunohistochemistry). Pre-treatment with BSCI (i) decreased LPS-induced PTB (64% versus 100%, P < 0.05); (ii) significantly attenuated cytokine/chemokine expression in maternal tissues (plasma, liver, myometrium, decidua); (iii) significantly decreased neutrophil infiltration in the mouse myometrium. BSCI-treated mice in which PTB was delayed till term had live foetuses with normal placental and foetal weight. BSCI represents a promising new class of therapeutics for PTB. In a mouse model of preterm labour, BCSI suppresses systemic inflammation in maternal tissues which resulted in the reduced incidence of LPS-mediated PTB. These data provide support for efforts to target inflammatory responses as a means of preventing PTB.

Keywords: chemokine inhibitor; infection; leucocyte infiltration; preterm labour; uterus.

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Figures

Fig. 1
Fig. 1
Scheme of injections and tissue collection. On GD14, pregnant mice [‘Vehicle’ group (n = 50) and ‘Broad Spectrum Chemokine Inhibitor’ (BSCI) group (n = 50)] were injected subcutaneously with the first dose of BSCI (10 mg/kg/day) or vehicle (ethanol/oil). In 24 hrs, on GD15, pregnant mice received a second injection of BSCI or vehicle. At the same time, half of vehicle group (n = 25) and half of BSCI group (n = 25) received an injection of lipopolysaccharide (LPS; 50 μg). The second half of vehicle group (n = 25) and half of BSCI group (n = 25) received an injection of sterile PBS. The LPS injections were given intraperitoneally. (A) Long-term effect of BSCI. Pregnant mice were observed until delivery to record PTD rate. All BSCI-treated animals from LPS and saline groups that did not deliver preterm were given daily injections of BSCI. Mice from both study groups that carry the pregnancy to term were killed before delivery on GD18.75. The number of live pups per litter, the number of foetal resorption sites, birth weights and placental weights were recorded. (B) Short-term effect of BSCI. Uterine tissues were collected at 2-, 6-, and 12-hr time-points. Two hours after LPS injection (t = 2 hrs), the first six animals from each groups were killed, and maternal and foetal tissues were collected for analysis. After 4 hrs (t = 6 hrs), six animals from each group were killed and maternal and foetal tissues were collected for analysis. The remaining animals were killed exactly 12 hrs after the administration of LPS (t = 12 hrs) and tissues were collected for biochemical and immunohistochemical evaluation. White arrows represent the day of vehicle injection, grey arrows represent the day of BSCI injection, black arrows represent the time of LPS administration, thatched arrows represent the time of saline administration and black arrowheads represent the time of tissue collection.
Fig. 2
Fig. 2
Temporal changes in cytokine protein levels of the maternal blood plasma from GD15 pregnant mice challenged with lipopolysaccharide (LPS) and treated with Broad Spectrum Chemokine Inhibitor (BSCI). (A) Pro-inflammatory (IL-1b, IL-6, IL-12 (p40), TNF-α), Csf2 (Gm-scf) and anti-inflammatory (IL-10) cytokines; (B) Chemokines Ccl2 (Mcp1) and Cxcl1 (KC/Groa) protein expression were detected by multiplex magnetic bead assay following systemic LPS administration and treatment with BSCI. Shown are vehicle (white bars), BSCI-treated (thatched bars), LPS-injected (black bars) and LPS-injected BSCI-treated samples (grey bars), n = 5–6/group. Two-way anova was utilized followed by Bonferroni posttest. Results were expressed as mean ± SEM. Significant difference with vehicle is indicated by * (P < 0.05), ** (P < 0.01) and *** (P < 0.001).
Fig. 3
Fig. 3
Changes in cytokine mRNA levels in the mouse liver of GD15 pregnant mice following systemic lipopolysaccharide (LPS) administration and treatment with Broad Spectrum Chemokine Inhibitor (BSCI). (A) Pro-inflammatory (IL-1b, IL-6, IL-12b, TNF, Csf2/Gmscf) and anti-inflammatory (IL-10) cytokines; (B) Chemokines Ccl2 (Mcp1), Ccl4 (Mip1b), Cxcl1 (KC or Groa) and Cxcl2 (Mip2a) mRNA expression were detected by Real-Time RT-PCR. Shown are vehicle (white bars), BSCI-treated (thatched bars), LPS-injected (black bars) and LPS-injected BSCI-treated samples (grey bars), n = 5–6/group. Two-way anova was utilized followed by Bonferroni posttests. Results were expressed as mean ± SEM. Significant difference with vehicle is indicated by * (P < 0.05), ** (P < 0.01) and *** (P < 0.001).
Fig. 4
Fig. 4
Changes in cytokine mRNA levels in the mouse myometrium of GD15 pregnant mice following systemic lipopolysaccharide (LPS) administration and treatment with Broad Spectrum Chemokine Inhibitor (BSCI). (A) Pro-inflammatory (IL-1b, IL-6, IL-12b, TNF, Csf2) and anti-inflammatory (IL-10) cytokines; (B) Chemokines Ccl2, Ccl4, Cxcl1 and Cxcl2 mRNA expression were detected by Real-Time RT-PCR. Shown are vehicle (white bars), BSCI-treated (thatched bars), LPS-injected (black bars) and LPS-injected BSCI-treated samples (grey bars), n = 5–6/group. Two-way anova was utilized followed by Bonferroni posttest. Results were expressed as mean ± SEM. Significant difference with vehicle is indicated by * (P < 0.05), ** (P < 0.01) and *** (P < 0.001).
Fig. 5
Fig. 5
Changes in cytokine mRNA levels in the mouse decidua of GD15 pregnant mice following systemic lipopolysaccharide (LPS) administration and treatment with Broad Spectrum Chemokine Inhibitor (BSCI). (A) Pro-inflammatory (IL-1b, IL-6, IL-12b, TNF, Csf2) and anti-inflammatory (IL-10) cytokines; (B) Chemokines Ccl2, Ccl4, Cxcl1 and Cxcl2 mRNA expression were detected by Real-Time RT-PCR. Shown are vehicle (white bars), BSCI-treated (thatched bars), LPS-injected (black bars) and LPS-injected BSCI-treated samples (grey bars), n = 5–6/group. Two-way anova was utilized followed by Bonferroni posttest. Results were expressed as mean ± SEM. Significant difference with vehicle is indicated by * (P < 0.05), ** (P < 0.01) and *** (P < 0.001).
Fig. 6
Fig. 6
Temporal change in cytokine protein levels of the amniotic fluid from GD15 pregnant mice. (A) Pro-inflammatory (IL-1b, IL-6, IL-12(p40), TNF-α, Csf2) and anti-inflammatory (IL-10) cytokines; (B) Chemokines Ccl2 and Cxcl1 protein expression were detected by multiplex magnetic bead assay following systemic lipopolysaccharide (LPS) administration and treatment with Broad Spectrum Chemokine Inhibitor (BSCI). Shown are vehicle (white bars), BSCI-treated (thatched bars), LPS-injected (black bars) and LPS-injected BSCI-treated samples (grey bars), n = 5–6/group. Two-way anova was utilized followed by Bonferroni posttests. Results were expressed as mean ± SEM. Significant difference with vehicle is indicated by * (P < 0.05), ** (P < 0.01) and *** (P < 0.001).
Fig. 7
Fig. 7
Neutrophil and macrophage infiltration into the mouse uterus 12 hrs after lipopolysaccharide (LPS) and/or Broad Spectrum Chemokine Inhibitor (BSCI) administration. Neutrophils were identified using anti-Neu7/4 antibody and macrophages were identified using anti-F4/80 antibody. NewCast software was used to quantify neutrophil and macrophage numbers in the myometrium and decidua. Shown are vehicle (white bars), BSCI-treated (thatched bars), LPS-challenged (black bars) and LPS-challenged, BSCI-treated (grey bars) samples. Results were expressed as mean ± SEM (n = 4). One-way anova was utilized followed by Newman-Keuls posttest. Significant difference with vehicle is indicated by * (P < 0.05), ** (P < 0.01) and *** (P < 0.001).
Fig. 8
Fig. 8
Changes in cytokine mRNA levels in the mouse placenta of GD15 pregnant mice following systemic lipopolysaccharide (LPS) administration and treatment with Broad Spectrum Chemokine Inhibitor (BSCI). (A) Pro-inflammatory (IL-1b, IL-6, IL-12b, TNF, Csf2) and anti-inflammatory (IL-10) cytokines; (B) Chemokines Ccl2, Ccl4, Cxcl1 and Cxcl2 mRNA expression were detected by Real-Time RT-PCR. Shown are vehicle (white bars), BSCI-treated (thatched bars), LPS-injected (black bars) and LPS-injected BSCI-treated samples (grey bars), n = 5–6/group. Two-way anova was utilized followed by Bonferroni posttests. Results were expressed as mean ± SEM. Significant difference with vehicle is indicated by * (P < 0.05), ** (P < 0.01) and *** (P < 0.001).
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References

    1. Lawn JE, Cousens S, Zupan J. 4 million neonatal deaths: when? Where? Why? Lancet. 2005;365:891–900. - PubMed
    1. Howson CP. Born too soon: global action report on preterm birth. Geneva: WHO; 2012.
    1. Too early, too small: a profile of small babies across Canada. Ottawa: Canadian Institute for Health Information; 2009.
    1. Shynlova O, Nedd-Roderique T, Li Y, et al. Infiltration of myeloid cells into decidua is a critical early event in the labour cascade and post-partum uterine remodelling. J Cell Mol Med. 2013;17:311–24. - PMC - PubMed
    1. Shynlova O, Nedd-Roderique T, Li Y, et al. Myometrial immune cells contribute to term parturition, preterm labour and post-partum involution in mice. J Cell Mol Med. 2013;17:90–102. - PMC - PubMed

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