Myometrial progesterone receptor determines a transcription program for uterine remodeling and contractions during pregnancy.

The uterine myometrium expands and maintains contractile quiescence before parturition. While the steroid hormone progesterone blocks labor, the role of progesterone signaling in myometrial expansion remains elusive. This study investigated the myometrial functions of the progesterone receptor, PGR. Pgr ablation in mouse smooth muscle leads to subfertility, oviductal embryo retention, and impaired myometrial adaptation to pregnancy. While gross morphology between mutant and control uteri are comparable, mutant uteri manifest a decrease of 76.6% oxytocin-stimulated contractility in a pseudopregnant context with a reduced expression of intracellular calcium homeostasis genes including Pde5a and Plcb4. At mid-pregnancy, the mutant myometrium exhibits discontinuous myofibers and disarrayed extracellular matrix at the conceptus site. Transcriptome of the mutant mid-pregnant uterine wall manifests altered muscle and extracellular matrix profiles and resembles that of late-pregnancy control tissues. A survey of PGR occupancy, H3K27ac histone marks, and chromatin looping annotates cis-acting elements that may direct gene expression of mid-pregnancy uteri for uterine remodeling. Further analyses suggest that major muscle and matrix regulators Myocd and Ccn2 and smooth muscle building block genes are PGR direct downstream targets. Cataloging enhancers that are topologically associated with progesterone downstream genes reveals distinctive patterns of transcription factor binding motifs in groups of enhancers and identifies potential regulatory partners of PGR outside its occupying sites. Finally, conserved correlations are found between estimated PGR activities and RNA abundance of downstream muscle and matrix genes in human myometrial tissues. In summary, PGR is pivotal to direct the molecular program for the uterus to remodel and support pregnancy.

Development of a dynamic machine learning algorithm to predict clinical pregnancy and live birth rate with embryo morphokinetics.

Objective: To evaluate the feasibility of generating a center-specific embryo morphokinetic algorithm by time-lapse microscopy to predict clinical pregnancy rates. Design: A retrospective cohort analysis. Setting: Academic fertility clinic in a tertiary hospital setting. Patients: Patients who underwent in vitro fertilization with embryos that underwent EmbryoScope time-lapse microscopy and subsequent transfer between 2014 and 2018. Interventions: None. Main Outcome Measures: Clinical pregnancy. Results: A supervised, random forest learning algorithm from 367 embryos successfully predicted clinical pregnancy from a training set with overall 65% sensitivity and 74% positive predictive value, with an area under the curve of 0.7 for the test set. Similar results were achieved for live birth outcomes. For the secondary analysis, embryo growth morphokinetics were grouped into five clusters using unsupervised clustering. The clusters that had the fastest morphokinetics (time to blastocyst = 97 hours) had pregnancy rates of 54%, whereas a cluster that had the slowest morphokinetics (time to blastocyst = 122 hours) had a pregnancy rate of 71%, although the differences were not statistically significant (P=.356). Other clusters had pregnancy rates of 51%-60%. Conclusions: This study shows the feasibility of a clinic-specific, noninvasive embryo morphokinetic simple machine learning model to predict clinical pregnancy rates.

Fertility Preservation and Financial Hardship among Adolescent and Young Adult Women with Cancer.

BACKGROUND: Financial hardship among adolescents and young adults (AYA) with cancer who receive gonadotoxic treatments may be exacerbated by the use of fertility services. This study examined whether AYA women with cancer who used fertility preservation had increased financial hardship. METHODS: AYA women with cancer in North Carolina and California completed a survey in 2018-2019. Cancer-related financial hardship was compared between women who cryopreserved oocytes or embryos for fertility preservation after cancer diagnosis (n = 65) and women who received gonadotoxic treatment and reported discussing fertility with their provider, but did not use fertility preservation (n = 491). Multivariable log-binomial regression was used to estimate prevalence ratios and 95% confidence intervals (CI). RESULTS: Women were a median age of 33 years at diagnosis and 7 years from diagnosis at the time of survey. Women who used fertility preservation were primarily ages 25 to 34 years at diagnosis (65%), non-Hispanic White (72%), and had at least a Bachelor's degree (85%). In adjusted analysis, use of fertility preservation was associated with 1.50 times the prevalence of material financial hardship (95% CI: 1.08-2.09). The magnitude of hardship was also substantially higher among women who used fertility preservation: 12% reported debt of ≥$25,000 versus 5% in the referent group. CONCLUSIONS: This study provides new evidence that cryopreserving oocytes or embryos after cancer diagnosis for future family building is associated with increased financial vulnerability. IMPACT: More legislation that mandates insurance coverage to mitigate hardships stemming from iatrogenic infertility could improve access to fertility preservation for young women with cancer.

Progesterone receptor isoform B regulates the Oxtr-Plcl2-Trpc3 pathway to suppress uterine contractility.

Uterine contractile dysfunction leads to pregnancy complications such as preterm birth and labor dystocia. In humans, it is hypothesized that progesterone receptor isoform PGR-B promotes a relaxed state of the myometrium, and PGR-A facilitates uterine contraction. This hypothesis was tested in vivo using transgenic mouse models that overexpress PGR-A or PGR-B in smooth muscle cells. Elevated PGR-B abundance results in a marked increase in gestational length compared to control mice (21.1 versus 19.1 d respectively, P < 0.05). In both ex vivo and in vivo experiments, PGR-B overexpression leads to prolonged labor, a significant decrease in uterine contractility, and a high incidence of labor dystocia. Conversely, PGR-A overexpression leads to an increase in uterine contractility without a change in gestational length. Uterine RNA sequencing at midpregnancy identified 1,174 isoform-specific downstream targets and 424 genes that are commonly regulated by both PGR isoforms. Gene signature analyses further reveal PGR-B for muscle relaxation and PGR-A being proinflammatory. Elevated PGR-B abundance reduces Oxtr and Trpc3 and increases Plcl2 expression, which manifests a genetic profile of compromised oxytocin signaling. Functionally, both endogenous PLCL2 and its paralog PLCL1 can attenuate uterine muscle cell contraction in a CRISPRa-based assay system. These findings provide in vivo support that PGR isoform levels determine distinct transcriptomic landscapes and pathways in myometrial function and labor, which may help further the understanding of abnormal uterine function in the clinical setting.

Karyotype is associated with timing of ovarian failure in women with Turner syndrome.

OBJECTIVE: To characterize the age of ovarian failure in Turner Syndrome (TS) patients by karyotype. METHODS: Retrospective cohort study of individuals with TS at an academic university hospital. Subjects were seen in TS Clinic at UNC Hospital between 2014 and 2018. Individuals were analyzed by karyotype category (45X, 45X/46XX mosaicism, miscellaneous) and percentage of 45X cells. Age at follicle-stimulating hormone> 30 was defined as the age at loss of ovarian function. RESULTS: A total of 79 patients were identified after excluding individuals with unknown ovarian function and those with Y chromosome material. Thirty-eight percent were 45X monosomic, 62% were 45X/46XX mosaic or miscellaneous karyotypes. Fifty-five of 79 (70%) patients had evidence of ovarian failure, median age of failure 11 years (IQR: 4,12). Ovarian failure was more prevalent among individuals with 45X karyotype (100%). The median age of ovarian failure for 45X patients (n=30) was 10 years old, which is significantly younger than other karyotypes (n=49), with a median of 15 years, p<0.01. Linear regression analysis found that 1 percentage point increase in 45X cells in the peripheral karyotype is associated with a 0.09 year decrease in age of ovarian failure (p value=0.01). Only 9% of individuals were referred for fertility counseling. CONCLUSIONS: There is a lower prevalence of ovarian failure among individuals with mosaic TS karyotypes, and referral rate for fertility counseling of patients with TS is low. These findings are in line with published literature. The finding that percentage of 45X cells in peripheral karyotype is associated with earlier age of ovarian failure is novel and warrants further investigation in a larger prospective cohort.

Surgically Extracted Epididymal Sperm from Men with Obstructive Azoospermia Results in Similar In Vitro Fertilization/Intracytoplasmic Sperm Injection Outcomes Compared with Normal Ejaculated Sperm.

PURPOSE: Controversy exists around the use of epididymal sperm for in vitro fertilization and intracytoplasmic sperm injection for couples with obstructive azoospermia, and the ability to reliably predict fertility outcomes with surgically extracted epididymal sperm remains limited. To provide additional clinical context, we sought to compare in vitro fertilization/intracytoplasmic sperm injection outcomes of epididymal sperm from couples with obstructive azoospermia to outcomes of couples using normal, ejaculated sperm. MATERIALS AND METHODS: We performed a case-control analysis of 40 couples who underwent office based epididymal sperm retrieval for obstructive azoospermia followed by in vitro fertilization/intracytoplasmic sperm injection compared with a control group of 38 female, age matched couples with no evidence of female factor infertility who underwent in vitro fertilization/intracytoplasmic sperm injection with normal, ejaculated sperm. Primary outcome was live birth on the initial embryo transfer. RESULTS: Epididymal samples yielded a median total motile sperm count of 9.1 million, compared to 81 million for ejaculated sperm. On the primary embryo transfer fertilization rate (71% vs 77%, p=0.2), blastulation rate (48% vs 59%, p=0.09), clinical pregnancy rate (70% vs 58%, p=0.4), and live birth rate (58% vs 47%, p=0.4) did not differ between epididymal and ejaculated sperm groups. CONCLUSIONS: For couples with a male partner with obstructive azoospermia epididymal sperm in vitro fertilization/intracytoplasmic sperm injection outcomes compare similarly with age matched controls undergoing in vitro fertilization/intracytoplasmic sperm injection using normal, ejaculated sperm. These results may help reproductive surgeons provide reassurance about the use of obstructed epididymal sperm as well as help guide discussions about anticipated outcomes of in vitro fertilization/intracytoplasmic sperm injection.

Embryos from polycystic ovary syndrome patients with hyperandrogenemia reach morula stage faster than controls.

OBJECTIVE: To investigate if patients with polycystic ovary syndrome (PCOS) have altered embryo morphokinetics when compared with controls. DESIGN: Retrospective cohort analysis. SETTING: Single academic fertility clinic in a tertiary hospital setting. PATIENTS: Age- and body mass index-matched patients who underwent in vitro fertilization diagnosed with PCOS using the Rotterdam criteria. A subanalysis was performed on patients with PCOS with hyperandrogenemia. Sixty-four patients with PCOS were identified with 990 embryos that were matched with 64 control patients with 628 embryos. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Time to blastulation. RESULTS: Embryos from women with PCOS displayed faster growth rate at t7, t8, and t9; all other morphokinetic points were similar. Patients with PCOS also had a higher number of oocytes retrieved. No differences were seen in the fertilization rate or blastulation rate. Patients with PCOS had a higher miscarriage rate (38.1% in PCOS vs. 18.8% in controls). Patients with hyperandrogenic PCOS showed a faster growth rate at t5, t6, t7, t8, t9, and morula. CONCLUSIONS: Embryos from women with PCOS grew faster until 9-cell stage and women with hyperandrogenic PCOS until morula. Patients with PCOS also showed a higher miscarriage rate. The alterations in early embryo development are consistent with altered fertility and obstetric outcomes in the population with PCOS and may be due to the hyperandrogenic microenvironment in the ovarian follicle.

A mouse model engineered to conditionally express the progesterone receptor-B isoform.

Using a Rosa26 gene targeting strategy in mouse embryonic stem cells, we have generated a new transgenic mouse (Pgr-B LSL ), which is designed to conditionally express the epitope-tagged mouse progesterone receptor-B (PGR-B) isoform when crossed with a specific cre driver mouse. To functionally validate this transgenic mouse, we crossed the Pgr-B LSL mouse with the MMTV-CREA transgenic mouse to create the MMTV-CREA/Pgr-B LSL bigenic (termed PR-B:OE to denote PGR-B overexpressor). As expected, transgene-derived PGR-B protein was specifically targeted to the virgin mammary gland epithelium. At a functional level, the PR-B:OE bigenic exhibited abnormal mammary morphogenesis-dilated epithelial ducts, precocious alveologenesis and lateral side-branching, along with a prominent proliferative signature-that resulted in pregnant PR-B:OE mice unable to exhibit mammary gland terminal differentiation at parturition. Because of this developmental failure, the PR-B:OE mammary gland was incapable of producing milk resulting in early neonatal death of otherwise healthy litters. This first line of analysis demonstrates the utility of the Pgr-B LSL mouse to examine the role of the PGR-B isoform in different physiologic and pathophysiologic systems that are responsive to progesterone.

Human endometrial stromal cell decidualization requires transcriptional reprogramming by PLZF.

Infertility and early embryo miscarriage is linked to inadequate endometrial decidualization. Although transcriptional reprogramming is known to drive decidualization in response to progesterone, the key signaling effectors that directly mediate this hormone response are not fully known. This knowledge gap is clinically significant because identifying the early signals that directly mediate progesterone-driven decidualization will address some of the current limitations in diagnosing and therapeutically treating patients at most risk for early pregnancy loss. We recently revealed that the promyelocytic leukemia zinc finger (PLZF) is a direct target of the progesterone receptor and is essential for decidualization of human endometrial stromal cells (hESCs). The purpose of this current work was to identify the genome-wide transcriptional program that is controlled by PLZF during hESC decidualization using an established in vitro hESC culture model, siRNA-mediated knockdown methods, and RNA-sequencing technology followed by bioinformatic analysis and validation. We discovered that PLZF is critical in the regulation of genes that are involved in cellular processes that are essential for the archetypal morphological and functional changes that occur when hESCs transform into epithelioid decidual cells such as proliferation and cell motility. We predict that the transcriptome datasets identified in this study will not only contribute to a broader understanding of PLZF-dependent endometrial decidualization at the molecular level but may advance the development of more effective molecular diagnostics and therapeutics for the clinical management of female infertility and subfertility that is based on a dysfunctional endometrium.

A Novel Use of Three-dimensional High-frequency Ultrasonography for Early Pregnancy Characterization in the Mouse.

High-frequency ultrasonography (HFUS) is a common method to non-invasively monitor the real-time development of the human fetus in utero. The mouse is routinely used as an in vivo model to study embryo implantation and pregnancy progression. Unfortunately, such murine studies require pregnancy interruption to enable follow-up phenotypic analysis. To address this issue, we used three-dimensional (3-D) reconstruction of HFUS imaging data for early detection and characterization of murine embryo implantation sites and their individual developmental progression in utero. Combining HFUS imaging with 3-D reconstruction and modeling, we were able to accurately quantify embryo implantation site number as well as monitor developmental progression in pregnant C57BL6J/129S mice from 5.5 days post coitus (d.p.c.) through to 9.5 d.p.c. with the use of a transducer. Measurements included: number, location, and volume of implantation sites as well as inter-implantation site spacing; embryo viability was assessed by cardiac activity monitoring. In the immediate post-implantation period (5.5 to 8.5 d.p.c.), 3-D reconstruction of the gravid uterus in both mesh and solid overlay format enabled visual representation of the developing pregnancies within each uterine horn. As genetically engineered mice continue to be used to characterize female reproductive phenotypes derived from uterine dysfunction, this method offers a new approach to detect, quantify, and characterize early implantation events in vivo. This novel use of 3-D HFUS imaging demonstrates the ability to successfully detect, visualize, and characterize embryo-implantation sites during early murine pregnancy in a non-invasive manner. The technology offers a significant improvement over current methods, which rely on the interruption of pregnancies for gross tissue and histopathologic characterization. Here we use a video and text format to describe how to successfully perform ultrasounds of early murine pregnancy to generate reliable and reproducible data with reconstruction of the uterine form in mesh and solid 3-D images.

A bioluminescence reporter mouse that monitors expression of constitutively active ß-catenin.

This short technical report describes the generation and characterization of a bioluminescence reporter mouse that is engineered to detect and longitudinally monitor the expression of doxycycline-induced constitutively active ß-catenin. The new responder transgenic mouse contains the TetO-ΔN89ß-CatTMILA transgene, which consists of the tet-operator followed by a bicistronic sequence encoding a stabilized form of active ß-catenin (ΔN89ß-catenin), an internal ribosome entry site, and the firefly luciferase gene. To confirm that the transgene operates as designed, TetO-ΔN89ß-CatTMILA transgenic mouse lines were crossed with an effector mouse that harbors the mouse mammary tumor virus-reverse tetracycline transactivator (MMTV-rtTA) transgene (termed MTB hereon), which primarily targets rtTA expression to the mammary epithelium. Following doxycycline administration, the resultant MTB/CatTMILA bigenic reporter exhibited precocious lobuloalveologenesis, ductal hyperplasia, and mammary adenocarcinomas, which were visualized and monitored by in vivo bioluminescence detection. Therefore, we predict that the TetO-ΔN89ß-CatTMILA transgenic responder mouse-when crossed with the appropriate effector transgenic-will have wide-applicability to non-invasively monitor the influence of constitutively active ß-catenin expression on cell-fate specification, proliferation, differentiation, and neoplastic transformation in a broad spectrum of target tissues.

Three-Dimensional High-Frequency Ultrasonography for Early Detection and Characterization of Embryo Implantation Site Development in the Mouse.

Ultrasonography is a powerful tool to non-invasively monitor in real time the development of the human fetus in utero. Although genetically engineered mice have served as valuable in vivo models to study both embryo implantation and pregnancy progression, such studies usually require sacrifice of parous mice for subsequent phenotypic analysis. To address this issue, we used three-dimensional (3-D) reconstruction in silico of high-frequency ultrasound (HFUS) imaging data for early detection and characterization of murine embryo implantation sites and their development in utero. With HFUS imaging followed by 3-D reconstruction, we were able to precisely quantify embryo implantation site number and embryonic developmental progression in pregnant C57BL6J/129S mice from as early as 5.5 days post coitus (d.p.c.) through to 9.5 d.p.c. using a VisualSonics Vevo 2100 (MS550S) transducer. In addition to measurements of implantation site number, location, volume and spacing, embryo viability via cardiac activity monitoring was also achieved. A total of 12 dams were imaged with HFUS with approximately 100 embryos examined per embryonic day. For the post-implantation period (5.5 to 8.5 d.p.c.), 3-D reconstruction of the gravid uterus in mesh or solid overlay format enabled visual representation in silico of implantation site location, number, spacing distances, and site volume within each uterine horn. Therefore, this short technical report describes the feasibility of using 3-D HFUS imaging for early detection and analysis of post-implantation events in the pregnant mouse with the ability to longitudinally monitor the development of these early pregnancy events in a non-invasive manner. As genetically engineered mice continue to be used to characterize female reproductive phenotypes, we believe this reliable and non-invasive method to detect, quantify, and characterize early implantation events will prove to be an invaluable investigative tool for the study of female infertility and subfertility phenotypes based on a defective uterus.

On-Site Fertility Preservation Services for Adolescents and Young Adults in a Comprehensive Cancer Center.

PURPOSE: Adolescents and young adults (AYAs) receiving cancer treatments that may impair fertility should receive counseling about risk of infertility and options for fertility preservation (FP) before treatment and/or during survivorship. Our objective was to define the AYA patient population referred to an on-site fertility consultation service within a comprehensive cancer center and determine factors associated with patients proceeding with FP treatment. METHODS: We conducted a retrospective chart review of AYA women who completed a consultation at the MD Anderson Fertility Preservation and Family Building Service during the first year of service. Records of 154 referred AYA patients were reviewed for age, ethnicity, cancer type gravidity and parity, survivorship status, and decision to pursue FP treatment. RESULTS: Patients (mean age 29.7) were Caucasian (55%), Hispanic (23%), and African American (10%). The majority of women (67%) were seen for FP before cancer treatment and the remaining sought options for family building while in survivorship. The most common cancer types were hematologic (29%), breast (25%), and gynecologic (23%). CONCLUSIONS: Patients referred to an on-site fertility consultation service were medically and ethnically diverse. Interest in fertility counseling and treatment was apparent in both survivorship pre- and postcancer treatment. Although the referral group was ethnically diverse, Caucasian women were most likely to pursue FP treatment compared to women of other ethnicities.

The Promyelocytic Leukemia Zinc Finger Transcription Factor Is Critical for Human Endometrial Stromal Cell Decidualization.

Progesterone, via the progesterone receptor (PGR), is essential for endometrial stromal cell decidualization, a cellular transformation event in which stromal fibroblasts differentiate into decidual cells. Uterine decidualization supports embryo implantation and placentation as well as subsequent events, which together ensure a successful pregnancy. Accordingly, impaired decidualization results not only in implantation failure or early fetal miscarriage, but also may lead to potential adverse outcomes in all three pregnancy trimesters. Transcriptional reprogramming on a genome-wide scale underlies progesterone dependent decidualization of the human endometrial stromal cell (hESC). However, identification of the functionally essential signals encoded by these global transcriptional changes remains incomplete. Importantly, this knowledge-gap undercuts future efforts to improve diagnosis and treatment of implantation failure based on a dysfunctional endometrium. By integrating genome-wide datasets derived from decidualization of hESCs in culture, we reveal that the promyelocytic leukemia zinc finger (PLZF) transcription factor is rapidly induced by progesterone and that this induction is indispensable for progesterone-dependent decidualization. Chromatin immunoprecipitation followed by next generation sequencing (ChIP-Seq) identified at least ten progesterone response elements within the PLZF gene, indicating that PLZF may act as a direct target of PGR signaling. The spatiotemporal expression profile for PLZF in both the human and mouse endometrium offers further support for stromal PLZF as a mediator of the progesterone decidual signal. To identify functional targets of PLZF, integration of PLZF ChIP-Seq and RNA Pol II RNA-Seq datasets revealed that the early growth response 1 (EGR1) transcription factor is a PLZF target for which its level of expression must be reduced to enable progesterone dependent hESC decidualization. Apart from furnishing essential insights into the molecular mechanisms by which progesterone drives hESC decidualization, our findings provide a new conceptual framework that could lead to new avenues for diagnosis and/or treatment of adverse reproductive outcomes associated with a dysfunctional uterus.

Collagen-binding α11 integrin expression in human myometrium and fibroids utilizing a novel RNA in situ probe.

OBJECTIVE: Integrin α11ß1 is a collagen receptor specific to fibroblasts that regulates myofibroblast differentiation. We sought to determine whether α11ß1 is expressed in myometrium and fibroids and whether tissue expression varies. DESIGN: Comparison of α11 in human myometrium and fibroids using Western blot and RNA in situ hybridization. MATERIALS AND METHODS: Specimens were obtained from fibroid and myometrium. For Western blots, we used a polyclonal antibody to integrin α11. RNA in situ hybridization was performed using a custom RNA probe for α11 subunit. RESULTS: Myometrium and fibroids express α11 integrin, with expression 2-fold greater in fibroids. The RNA probe offers a more precise method compared to Western blot using polyclonal human antibody. CONCLUSIONS: The difference in expression in myometrium and fibroids suggests that α11 is involved in the formation of myofibroblasts and fibroid development.

A pilot feasibility multicenter study of patients after excision of endometriosis.

OBJECTIVE: To serve as a pilot feasibility study for a randomized study of excision versus ablation in the treatment of endometriosis by (1) estimating the magnitude of change in symptoms after excision only at multiple referral centers and (2) determining the proportion of women willing to participate in a randomized trial. METHODS: We performed a multicenter prospective study of women undergoing excision for endometriosis (Canadian Task Force class II-3) at Duke University Center for Endometriosis Research & Treatment (currently the Saint Louis University Center for Endometriosis), Center for Endometriosis Care, Northshore University Health System, Memorial University (Canada), and Florida Hospital. The study comprised 100 female patients, aged 18 to 55 years, with endometriosis-suspected pelvic pain. The intervention was laparoscopic excision only of the abnormal peritoneum suspicious for endometriosis. The main outcome measures were quality of life, pelvic pain, dysmenorrhea, dyspareunia, and bowel and bladder symptoms. RESULTS: The mean follow-up period was 8.5 months. Excision of endometriosis showed a significant reduction in all pain scores except bowel symptoms, as well as significant improvement in quality of life. Of the patients, 84% were willing to participate in a randomized study. CONCLUSIONS: Quality of life is a needed primary outcome for any randomized study comparing excision versus ablation. A multicenter comparative trial is feasible, although quality assurance would have to be addressed. Patients were willing to be randomized even at surgical referral centers.

Spontaneous pregnancy reaches viability after low first trimester serum progesterone: a case report.

BACKGROUND: Progesterone is produced by the corpus luteum until completion of the luteal-placental shift at approximately 6-10 weeks following last menstruation. Studies have shown that first trimester progesterone levels are predictive of pregnancy viability, and some authors support a level of 5 ng/mL as an absolute threshold to indicate viability. CASE: A 47-year-old woman with recurrent pregnancy loss was noted to have a very low first trimester progesterone level (1.2 ng/mL), but the pregnancy progressed to viability. She unfortunately delivered an intrauterine fetal demise at 27 weeks and 3 days' gestation. CONCLUSION: A single serum progesterone level of < 5 ng/mL is suggestive, but not diagnostic, of a nonviable pregnancy. Routine uterine curettage during the evaluation of a pregnancy of unknown location using this level as an absolute cutoff may result in the interruption of a desired, viable pregnancy.

High oxygen prevents fetal lethality due to lack of catecholamines.

The catecholamine norepinephrine is required for fetal survival, but its essential function is unknown. When catecholamine-deficient [tyrosine hydroxylase (Th) null] mouse fetuses die at embryonic day (E)13.5-14.5, they resemble wild-type (wt) fetuses exposed to hypoxia. They exhibit bradycardia (28% reduction in heart rate), thin ventricular myocardium (20% reduction in tissue), epicardial detachment, and death with vascular congestion, hemorrhage, and edema. At E12.5, before the appearance of morphological deficits, catecholamine-deficient fetuses are preferentially killed by experimentally induced hypoxia and have lower tissue Po(2) levels than wt siblings. By microarray analysis (http://www.ncbi.nlm.nih.gov/geo; accession no. GSE10341), hypoxia-inducible factor-1 target genes are induced to a greater extent in null fetuses than in wt siblings, supporting the notion that mutants experience lower oxygen tension or have an enhanced response to hypoxia. Hypoxia induces a 13-fold increase in plasma norepinephrine levels, which would be expected to increase heart rate, thereby improving oxygen delivery in wt mice. Surprisingly, increasing maternal oxygen (inspired O(2) 33 or 63%) prevents the effects of catecholamine deficiency, restoring heart rate, myocardial tissue, and survival of Th null fetuses to wt levels. We suggest that norepinephrine mediates fetal survival by maintaining oxygen homeostasis.

Stat3 links activated keratinocytes and immunocytes required for development of psoriasis in a novel transgenic mouse model.

Here we report that epidermal keratinocytes in psoriatic lesions are characterized by activated Stat3. Transgenic mice with keratinocytes expressing a constitutively active Stat3 (K5.Stat3C mice) develop a skin phenotype either spontaneously, or in response to wounding, that closely resembles psoriasis. Keratinocytes from K5.Stat3C mice show upregulation of several molecules linked to the pathogenesis of psoriasis. In addition, the development of psoriatic lesions in K5.Stat3C mice requires cooperation between Stat3 activation in keratinocytes and activated T cells. Finally, abrogation of Stat3 function by a decoy oligonucleotide inhibits the onset and reverses established psoriatic lesions in K5.Stat3C mice. Thus, targeting Stat3 may be potentially therapeutic in the treatment of psoriasis.