Juan Gonzalez

Inflammation-induced preterm birth alters neuronal morphology in the mouse fetal brain

Adverse neurological outcome is a major cause of long‐term morbidity in ex‐preterm children. To investigate the effect of parturition and inflammation on the fetal brain, we utilized two in vivo mouse models of preterm birth. To mimic the most common human scenario of preterm birth, we used a mouse model of intrauterine inflammation by intrauterine infusion of lipopolysaccharide (LPS). To investigate the effect of parturition on the immature fetal brain, in the absence of inflammation, we used a non‐infectious model of preterm birth by administering RU486. Pro‐inflammatory cytokines (IL‐10, IL‐1β, IL‐6 and TNF‐α) in amniotic fluid and inflammatory biomarkers in maternal serum and amniotic fluid were compared between the two models using ELISA. Pro‐inflammatory cytokine expression was evaluated in the whole fetal brains from the two models. Primary neuronal cultures from the fetal cortex were established from the different models and controls in order to compare the neuronal morphology. Only the intrauterine inflammation model resulted in an elevation of inflammatory biomarkers in the maternal serum and amniotic fluid. Exposure to inflammation‐induced preterm birth, but not non‐infectious preterm birth, also resulted in an increase in cytokine mRNA in whole fetal brain and in disrupted fetal neuronal morphology. In particular, Microtubule‐associated protein 2 (MAP2) staining was decreased and the number of dendrites was reduced (P < 0.001, ANOVA between groups). These results suggest that inflammation‐induced preterm birth and not the process of preterm birth may result in neuroinflammation and alter fetal neuronal morphology.

Preventing cervical ripening: the primary mechanism by which progestational agents prevent preterm birth?

OBJECTIVEnRecent clinical trials suggest that progestational agents may prevent preterm birth, specifically in women with short cervices. These studies sought to assess novel pathways by which progestational agents (PAs) may modify signal transduction pathways that are involved in cervical ripening.nnnSTUDY DESIGNnA microarray analysis was performed on pregnant mouse cervix that was exposed to a MPA. Appropriate microarray and cluster analyses were performed. Target genes of interest were investigated in both PA- and inflammation-exposed cervices by quantitative polymerase chain reaction and immunohistochemistry.nnnRESULTSnMicroarray analysis identified both the previously recognized and novel pathways that are involved in cervical ripening. PAs differentially regulate expression of claudin-2, hyaluronan synthase 2, and lipocalin 2. Claudin expression is significantly decreased by inflammation, which is prevented by PAs.nnnCONCLUSIONnPAs significantly modulate gene expression in the cervix in the presence and absence of inflammation. The regulation of these pathways, specifically claudin proteins, may be a critical mechanism by which PAs prevent preterm birth, especially in women with premature cervical shortening.

Preterm and Term Cervical Ripening in CD1 Mice (Mus musculus): Similar or Divergent Molecular Mechanisms?

Premature cervical ripening is believed to contribute to preterm birth (PTB). Preterm cervical ripening may be due to an aberrant regulation in timing of the same processes that occur at term, or may result from unique molecular mechanisms. Using mouse models of PTB, this study sought to investigate if the molecular mechanisms that govern cervical ripening were similar between preterm and term. Lipopolysaccharide (LPS) is infused into the uterine horn to create a mouse model of inflammation-induced PTB. For a noninfectious model of PTB, RU486 was administered. Both models result in delivery of pups in 8–24 h. Cervical tissues were collected from these models, as well as throughout gestation. Cervical tissues from E15 (preterm), E15 LPS (preterm inflammation), and E18.5 (term) were used for microarray analysis (n = 18). Additional experiments using gestational time course specimens were performed to confirm microarray results. Specific gene pathways were differentially expressed between the groups. Genes involved in immunity and inflammation were increased in the cervix in inflammation-induced PTB; term labor was not associated with differential expression of immune pathways. Cytokine expression was not increased in cervices during term labor, but was increased in the pospartum period. Epithelial cell differentiation pathway was significantly altered in term, but not preterm, labor. Activation of immune pathways may be sufficient for cervial ripening, but does not appear necessary. Differential expression of the epithelial cell differentiation pathway appears necessary in the process of cervical repair. Our results indicate that the molecular mechanisms governing preterm and term cervical ripening are distinctly different.

Medroxyprogesterone acetate modulates the immune response in the uterus, cervix and placenta in a mouse model of preterm birth

Objective. These studies sought to determine whether a progestational agent, specifically medroxyprogesterone acetate (MPA) prevents inflammation-induced preterm birth, in a mouse model, through modulation of the host immune response. Study design. Using an established mouse model of inflammation-induced preterm birth, the activation of the immune response in maternal serum, uterus, cervix and placenta was assessed. In addition, the ability of MPA to modulate this response was investigated. Message RNA and protein expression were assessed by quantitative PCR and ELISAs respectively. Results. Intrauterine inflammation promotes a significant up-regulation of both TH1 and TH2 mediators in all tissues studies though the response is divergent by time and tissue studied. MPA significantly differentially regulates this immune response in the uterus, cervix and placenta. Conclusions. In the setting of inflammation-induced preterm birth, the host immune response is activated and not limited to a traditional TH1 bias. The ability of MPA to modulate the immune response may be a critical mechanism by which progestins prevent preterm birth.

Beyond white matter damage: fetal neuronal injury in a mouse model of preterm birth

OBJECTIVEnThe purpose of this study was to elucidate possible mechanisms of fetal neuronal injury in inflammation-induced preterm birth.nnnSTUDY DESIGNnWith the use of a mouse model of preterm birth, the following primary cultures were prepared from fetal brains: (1) control neurons (CNs), (2) lipopolysaccharide-exposed neurons (LNs), (3) control coculture (CCC) that consisted of neurons and glia, and (4) lipopolysaccharide-exposed coculture (LCC) that consisted of lipopolysaccharide-exposed neurons and glia. CNs and LNs were treated with culture media from CN, LN, CCC, and LCC after 24 hours in vitro. Immunocytochemistry was performed for culture characterization and neuronal morphologic evidence. Quantitative polymerase chain reaction was performed for neuronal differentiation marker, microtubule-associated protein 2, and for cell death mediators, caspases 1, 3, and 9.nnnRESULTSnLipopolysaccharide exposure in vivo did not influence neuronal or glial content in cocultures but decreased the expression of microtubule-associated protein 2 in LNs. Media from LNs and LCCs induced morphologic changes in control neurons that were comparable with LNs. The neuronal damage caused by in vivo exposure (LNs) could not be reversed by media from control groups.nnnCONCLUSIONnLipopolysaccharide-induced preterm birth may be responsible for irreversible neuronal injury.

A Mouse Model of Term Chorioamnionitis: Unraveling Causes of Adverse Neurological Outcomes

Maternal fever and/or chorioamnionitis at term are associated with an increased prevalence of adverse neurobehavioral outcomes in exposed offspring. Since the mechanisms of such injury are currently unknown, the objectives of this study were to elucidate whether intrauterine inflammation at term results in fetal brain injury. Specifically, we assessed brain injury by investigating the cytokine response, white matter damage, and neuronal injury and viability. A mouse model of intrauterine inflammation at term was utilized by injecting lipopolysaccharide (LPS), or normal saline into uterine horn. Compared to saline-exposed, LPS-exposed fetal brains had significantly increased IL-1β and IL-6 messenger RNA (mRNA) expression (P < .05 for both) and IL-6 protein levels by enzyme-linked immunosorbent assay (ELISA; P < 0.05). Fetal neurons were affected by the intrauterine and fetal brain inflammation, as demonstrated by significantly decreased microtubule-associated protein 2 (MAP2) mRNA expression and a decrease in immunocytochemical staining (a marker of neuronal cytoskeleton development; P < .05), altered neuronal morphology (P < 0.05), and delayed neurotoxicity (P < .05). These fetal neuronal changes occurred without overt changes in white matter damage markers. Marker of astrocyte development and astrogliosis (glial fibrillary acidic protein [GFAP]) did not show an increase; pro-oligodendrocyte marker (PLP1/DM20) was not significantly changed (P > .05). These studies may provide a critical mechanism for the observed long-term adverse neurobehavioral outcomes after exposure to chorioamnionitis at term.

An Open Label Pilot Study of Transcranial Magnetic Stimulation for Pregnant Women with Major Depressive Disorder

OBJECTIVEnDespite the data that major depressive disorder (MDD) is common during pregnancy and that pregnant women prefer nonmedication treatment options, there is a paucity of research examining alternative treatments for this special population. We present the results of an open label pilot study examining treatment with transcranial magnetic stimulation (TMS) in pregnant women with MDD.nnnMETHODSnTen women with MDD in the second or third trimester of pregnancy were treated with 20 sessions of 1-Hz TMS at 100% of motor threshold (MT) to the right dorsolateral prefrontal cortex. The total study dose was 6000 pulses. Antenatal monitoring was performed during treatment sessions 1, 10, and 20.nnnRESULTSnSeven of ten (70%) subjects responded (decrease ≥50% in Hamilton Depression Rating Scale [HDRS-17] scores). No adverse pregnancy or fetal outcomes were observed. All infants were admitted to the well baby nursery and were discharged with the mother. Mild headache was the only common adverse event and was reported by 4 of 10 (40%) subjects.nnnCONCLUSIONSnTMS appears to be a promising treatment option for pregnant women who do not wish to take antidepressant medications.

Inflammation-Induced Preterm Birth in a Murine Model Is Associated with Increases in Fetal Macrophages and Circulating Erythroid Precursors

The presence of intrauterine inflammation has been associated with adverse neurologic outcomes in preterm infants, but the precise mechanisms of fetal brain injury remain unclear. We sought to evaluate inflammatory cell trafficking, fetal organ damage, and molecular regulation in the fetoplacental unit using an established mouse model of preterm birth associated with intrauterine inflammation. Gestational sacs were harvested 6 hours after intrauterine infusion of saline or lipopolysaccharide (LPS). Histologic, immunohistochemical, and molecular investigations were performed to identify target organ damage and the cellular phenotype of inflammatory cells and to quantify circulating inflammatory and hematopoietic mediators within the placental and fetal tissue. There was widespread increase in fetal macrophages in LPS-exposed pups, including within the leptomeninges of the brain, associated with significantly higher of interleukin 6 levels in LPS-exposed pups. Although no specific central nervous system injury (necrosis or apoptosis) was documented, liver hematomas were seen significantly more frequently in LPS-exposed pups. Circulating nucleated fetal erythrocytes were also present more frequently with LPS exposure without significantly higher erythropoietin levels than saline-exposed mice. The presence of increased macrophages, increased circulating interleukin 6 levels, and increased circulating erythroid precursors in LPS-exposed pups suggests that these are significant factors associated with potential target organ damage, such as liver hematomas, associated with intrauterine inflammation and preterm birth. The role of macrophages within the fetal leptomeninges is unclear, but they may play an important role in inflammatory-mediated brain damage, and further investigation of their significance and potential as therapeutic targets is warranted.

Maternal mortality from systemic illness: unraveling the contribution of the immune response.

OBJECTIVEnMaternal morbidity and/or mortality (MM) is increased in pyelonephritis and influenza. Alterations in the immune response could account for the increase MM. We sought to determine whether the immune response is functionally different during pregnant and nonpregnant (NP) states.nnnSTUDY DESIGNnMouse model of systemic and localized inflammation was used. Maternal serum was assessed for expression of T-helper cell type 1 and 2 cytokines. Maternal spleens were harvested for immunohistochemistry.nnnRESULTSnSystemic administration of lipopolysaccharides resulted in no mortality to NP mice compared with 88% in preterm and 100% in term mice. A potent cytokine response was present in both NP and pregnancy. Systemic inflammation in pregnancy results in increased CD8 and CD11c expression in spleens.nnnCONCLUSIONnDifferences in cytokine response to systemic inflammation is unlikley to modulate the increased MM during pregnancy. Altered T-cell and dendritic cell responses in pregnancy may be responsible for the increase in MM.

The Menopause: A Signal for the Future

Publisher Summary The menopause is overly laden with negative symbolism. Many of the behavioral complaints at the time of menopause can be explained by psychologic and sociocultural influences. Important interactions among biology, psychology, and culture do not occur, but it is time to stress the normalcy of this life event. Menopausal women do not suffer from a hormone deficiency disease. Hormone replacement therapy should be viewed as specific treatment for symptoms in the short term. Therapy remains effective for treating women with vasomotor symptoms and vaginal atrophy and selected women with osteoporosis. The benefits and risks of hormone therapy should be balanced in each individual. Part of the reason for the negative stereotypical views of menopause is that the initial characterization of menopause was derived from women with physical and psychologic difficulties. The variability in menopausal reactions makes the cross-sectional study design particularly unsuitable. More and larger longitudinal studies are needed to document what is normal and the variations around normal. It is important to educate women and clinicians about the normal events of this time. This physiologic event brings clinicians and patients together, providing the opportunity to enroll patients in a preventive health care program. Contrary to popular opinion, menopause is not a signal of impending decline, but rather a wonderful phenomenon that can signal the start of something positive, such as a good health program. Rather than being a lightning rod for social and personal problems, menopause can be a signal for the future.