Nardhy Gomez-Lopez

Maternal circulating leukocytes display early chemotactic responsiveness during late gestation

BackgroundParturition has been widely described as an immunological response; however, it is unknown how this is triggered. We hypothesized that an early event in parturition is an increased responsiveness of peripheral leukocytes to chemotactic stimuli expressed by reproductive tissues, and this precedes expression of tissue chemotactic activity, uterine activation and the systemic progesterone/estradiol shift.MethodsTissues and blood were collected from pregnant Long-Evans rats on gestational days (GD) 17, 20 and 22 (term gestation). We employed a validated Boyden chamber assay, flow cytometry, quantitative real time-polymerase chain reaction, and enzyme-linked immunosorbent assays.ResultsWe found that GD20 maternal peripheral leukocytes migrated more than those from GD17 when these were tested with GD22 uterus and cervix extracts. Leukocytes on GD20 also displayed a significant increase in chemokine (C-C motif) ligand 2 (Ccl2) gene expression and this correlated with an increase in peripheral granulocyte proportions and a decrease in B cell and monocyte proportions. Tissue chemotactic activity and specific chemokines (CCL2, chemokine (C-X-C motif) ligand 1/CXCL1, and CXCL10) were mostly unchanged from GD17 to GD20 and increased only on GD22. CXCL10 peaked on GD20 in cervical tissues. As expected, prostaglandin F2α receptor and oxytocin receptor gene expression increased dramatically between GD20 and 22. Progesterone concentrations fell and estradiol-17β concentrations increased in peripheral serum, cervical and uterine tissue extracts between GD20 and 22.ConclusionMaternal circulating leukocytes display early chemotactic responsiveness, which leads to their infiltration into the uterus where they may participate in the process of parturition.

The effect of age on the expression of apoptosis biomarkers in human spermatozoa

OBJECTIVEnTo evaluate the impact of age on the expression of apoptotic biomarkers in human spermatozoa.nnnDESIGNnCross sectional, prospective study.nnnSETTINGnAcademic centers.nnnPATIENT(S)nHealthy volunteers with proven fertility, stratified by age (n = 25, range: 20-68 years).nnnINTERVENTION(S)nExamination of serum hormone levels and basic semen parameters, and assessment of early (plasma membrane translocation of phosphatidylserine) and late (DNA fragmentation) sperm apoptotic markers by flow cytometry (using Annexin-V binding and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling).nnnMAIN OUTCOME MEASURE(S)nApoptosis markers.nnnRESULT(S)nAdvancing male age was significantly and positively correlated with Annexin-V binding results. Although not significant, there was a clear trend for increased DNA fragmentation in the older groups. The age threshold for these observations appears to be 40 years. Advancing male age was positively correlated with FSH and sex hormone-binding globulin (SHBG) levels, and negatively correlated with sperm concentration.nnnCONCLUSION(S)nAdvancing male age is associated with the expression of early apoptotic markers as evidenced by significantly increased plasma membrane translocation of phosphatidylserine, as well as with a more subtle proportion of sperm carrying DNA fragmentation. This study confirmed that male age is also associated with a decline in sperm concentration.

Choriodecidual cells from term human pregnancies show distinctive functional properties related to the induction of labor.

Human parturition is associated with an intrauterine pro‐inflammatory environment in the choriodecidua. Evidence that some mediators of this signaling cascade also elicit responses leading to labor prompted us to characterize the cellular sources of these mediators in the human choriodecidua.

Chemotactic Activity of Gestational Tissues Through Late Pregnancy, Term Labor, and RU486‐Induced Preterm Labor in Guinea Pigs

Is increased leukocyte chemotactic activity (CA) from gestational tissues necessary for term or preterm labor in guinea pigs?

Development and Validation of a Rex1-RFP Potency Activity Reporter Assay That Quantifies Stress-Forced Potency Loss in Mouse Embryonic Stem Cells.

Assays for embryonic stem cells (ESCs) of the blastocyst are needed to quantify stress-induced decreases of potent subpopulations. High-throughput screens (HTSs) of stressed ESCs quantify embryonic stress, diminishing laboratory animal needs. Normal or stress-induced ESC differentiation is marked by Rex1 potency factor loss. Potency reporter ESC assays were developed, using low-stress techniques to create transgenic ESCs. Rex1 and Oct4 promoters drove RFP and green fluorescent protein (GFP) expression, respectively. Lentivirus infection and fluorescence-activated cell sorting selection of ESCs obviated the need for stressful electroporation and antibiotic selection, respectively. We showed using immunoblots, microscopic analysis, flow cytometry, and fluorescence microplate reader that the response to stress of potency-reporter ESCs is similar to parental ESCs assayed by biochemical means. Stress caused a dose-dependent decrease in bright Rex1-RFP(+) ESCs and increase in Rex1 dim ESCs. At highest stress, ∼ 20% of bright Rex1-RFP cells are lost coinciding with a 2.8-fold increase in Rex1-RFP dim cells that approach 20%. This conversion of bright to dim cells tested by flow cytometry is commensurate with about 60% loss in fluorescence measured by microplate reader. Dose-dependent stress-induced Rex1-RFP and endogenous Rex1 protein decreases are similar. The data show that Rex1 reporter ESCs accurately report stress in a microplate reader-based HTS. The increasing dim Rex1 subpopulation size is balanced by the decreasing total ESC number during culture at multiple sorbitol doses. This is consistent with previous observations that stress forces potency decrease and differentiation increase to compensate for stress-induced diminished stem cell population growth.

Hypoxic Stress Forces Irreversible Differentiation of a Majority of Mouse Trophoblast Stem Cells Despite FGF4

ABSTRACT Hypoxic, hyperosmotic, and genotoxic stress slow mouse trophoblast stem cell (mTSC) proliferation, decrease potency/stemness, and increase differentiation. Previous reports suggest a period of reversibility in stress-induced mTSC differentiation. Here we show that hypoxic stress at 0.5% O2 decreased potency factor protein by ∼60%–90% and reduced growth to nil. Hypoxia caused a 35-fold increase in apoptosis at Day 3 and a 2-fold increase at Day 6 above baseline. The baseline apoptosis rate was only 0.3%. Total protein was never less than baseline during hypoxic treatment, suggesting 0.5% O2 is a robust, nonmorbid stressor. Hypoxic stress induced ∼50% of trophoblast giant cell (TGC) differentiation with a simultaneous 5- to 6-fold increase in the TGC product antiluteolytic prolactin family 3, subfamily d, member 1 (PRL3D1), despite the presence of fibroblast growth factor 4 (FGF4). Hypoxia-induced TGC differentiation was also supported by potency and differentiation mRNA marker analysis. FGF4 removal at 20% O2 committed cell fate towards irreversible differentiation at 2 days, with similar TGC percentages after an additional 3 days of culture under potency conditions when FGF4 was readded or under differentiation conditions without FGF4. However, hypoxic stress required 4 days to irreversibly differentiate cells. Runted stem cell growth, forced differentiation of fewer cells, and irreversible differentiation limit total available stem cell population. Were mTSCs to respond to stress in a similar mode in vivo, miscarriage might occur as a result, which should be tested in the future.

Evaluation of reference genes for expression studies in leukocytes from term human pregnancy.

INTRODUCTIONnHuman labor is considered an inflammatory process modulated by systemic and local leukocytes that infiltrate into the maternal-fetal interface. The putative roles of these leukocytes are currently being studied with gene expression assays. Such assays are normalized by the expression of housekeeping genes. However, expression of housekeeping genes may vary depending on the cell type and/or the experimental conditions. The aim of this study was to analyze the expression stability of several housekeeping genes in leukocytes from term human pregnancies, considering both anatomical origin and presence of labor.nnnMETHODSnWe analyzed the gene expression of ACTB, B2M, GAPDH, GUSB, PGK1, RN18S1, TBP and UBC in leukocytes from maternal peripheral blood, placental blood and choriodecidua in women delivering at term with or without the presence of labor through real-time qPCR. Then we used geNorm to evaluate expression stability and pairwise variation.nnnRESULTSnThe expression of all tested genes showed to be stable independent of the anatomical compartment and the absence or presence of labor. However, PGK1, GUSB and TBP showed to be the most stable and RN18S1 the least stable. Pairwise variation analyses showed that only two genes are needed for normalization yet the inclusion of a third improves its accuracy.nnnDISCUSSIONnPGK1, GUSB and TBP are the most adequate reference genes for gene expression normalization in leukocytes from term pregnancies, regardless of their anatomical origin (maternal peripheral blood, placental blood or choriodecidua) or the presence or absence of labor. Our study is the first report on housekeeping gene stability in leukocytes from healthy pregnant women.

Rosiglitazone Regulates TLR4 and Rescues HO-1 and NRF2 Expression in Myometrial and Decidual Macrophages in Inflammation-Induced Preterm Birth

Introduction: Elevated inflammation accounts for approximately 30% of preterm birth (PTB) cases. We previously reported that targeting the peroxisome proliferator–activated receptor gamma (PPARγ) pathway reduced the incidence of PTB in the mouse model of endotoxin-induced PTB. The PPARγ has proven anti-inflammatory functions and its activation via rosiglitazone significantly downregulated the systemic inflammatory response and reduced PTB and stillbirth rate by 30% and 41%, respectively, in our model. Oxidative stress is inseparable from inflammation, and rosiglitazone has a reported antioxidative activity. In the current study, we therefore aimed to evaluate whether rosiglitazone treatment had effects outside of inflammatory pathway, specifically on the antioxidation pathway in our model. Methods: Pregnant C57BL/6J mice (E16.5) were treated with phosphate-buffered saline (PBS), rosiglitazone (Rosi), lipopolysaccharide (LPS; 10µg in 200µL 1XPBS), or LPS + Rosi (6 hours after the LPS injection). The myometrial and decidual tissues were collected and processed for macrophage isolation using magnetic cell sorting and F4/80+ antibody. Expression levels of antioxidative factors—Nrf2 and Ho-1—along with the LPS receptor Tlr4 were quantified by quantitative polymerase chain reaction. The protein levels were assessed by immunofluorescence staining. Results: Both the decidual and myometrial macrophages from the LPS-treated animals showed significantly lowered expression of Ho-1 and Nrf2 and higher expression of Tlr4 when compared to the PBS control group. The macrophages from the animals in the LPS + Rosi group had significantly elevated expression of Ho-1 and Nrf2 and downregulated expression of Tlr4 when compared to the LPS group. Conclusion: Rosiglitazone administration prevents PTB by downregulating inflammation and upregulating antioxidative response.

The apoptotic pathway in fertile and subfertile men: a case-control and prospective study to examine the impact of merocyanine 540 bodies on ejaculated spermatozoa.

OBJECTIVEnTo evaluate the presence of merocyanine 540 (M540) bodies and their impact on the measurement of apoptotic biomarkers in human spermatozoa.nnnDESIGNnCase-control, prospective study.nnnSETTINGnAcademic centers.nnnPATIENT(S)nFertile and subfertile subjects.nnnINTERVENTION(S)nSemen samples from subfertile and fertile men, 11 per group, were analyzed for basic semen parameters and early (annexin-V binding) and late (terminal deoxynucleotidyl transferase dUTP nick end labeling [TUNEL]) sperm apoptotic biomarkers by flow cytometry. Samples were also stained with M540 to assess the presence of M540 apoptotic bodies.nnnMAIN OUTCOME MEASURE(S)nPresence of M540 apoptotic bodies.nnnRESULT(S)nGroups differed significantly in the expression of early and late apoptosis biomarkers. The percentage of M540 bodies between groups was not different. The exclusion of M540 bodies from TUNEL results did not have a significant impact on measurement in either fertile or subfertile groups.nnnCONCLUSION(S)nThis study confirmed the occurrence of M540 bodies in semen and that male factor infertility is associated with an increased expression of apoptosis biomarkers. Moreover, we demonstrated that the presence of M540 bodies did not affect the quantification of apoptotic biomarkers in either group.

Novel expression of CD11b in epithelial ovarian cancer: Potential therapeutic target

OBJECTIVEnThe objective of this study was to determine the expression, and effect of targeting CD11b with a monoclonal antibody in ovarian cancer cells.nnnMETHODSnCD11b expression was determined in epithelial ovarian cancer (EOC) cell lines and tissues by immunofluorescence and flow cytometry. Cytotoxicity of the CD11b antibody and synergism with chemothearapeutic drugs were determined by the MTT Cell Proliferation Assay in human macrophages, normal ovarian epithelial cells, and in both sensitive and chemoresistant EOC cell lines. Cell migration was assessed with a scratch assay and in vivo effects of the CD11b antibody was assessed with a nude mouse ovarian cancer xenograft model. Data was analyzed with either t-tests or one-way ANOVA.nnnRESULTSnCD11b was unexpectedly expressed in several EOC lines and tissues, but not normal tissues. Targeting CD11b with its monoclonal antibody resulted in intriguing cytotoxic effects in sensitive and chemoresistant EOC lines, while surprisingly not affecting normal cells. More importantly, the cytotoxicity of the CD11b antibody when combined with chemotherapeutic drugs (cisplatin or docetaxel) was significantly synergistic, in both sensitive and chemoresistant EOC cells. The anti-tumorigenic effect of the CD11b antibody was confirmed in an ovarian cancer nude mouse xenograft model.nnnCONCLUSIONnHere we identify CD11b as a novel target, which selectively induces cytotoxicity in ovarian cancer cells.