Safety and pharmacokinetics of imaradenant (AZD4635) in Japanese patients with advanced solid malignancies: a phase I, open-label study

PURPOSE

Imaradenant is a novel potent and selective adenosine A2A receptor antagonist that is hypothesized to reduce immune suppression in the tumor microenvironment. This phase I, open-label, dose-escalation study evaluated the safety, pharmacokinetics, and anti-tumor activity of imaradenant.

METHODS

Japanese patients with advanced solid malignancies received imaradenant 50 mg (n = 3) or 75 mg (n = 7) once daily (QD). The primary objective was safety and tolerability, and the secondary objectives were pharmacokinetics and anti-tumor activity.

RESULTS

The median treatment duration was 2.10 months and 2.14 months for the 50- and 75-mg QD cohorts, respectively. The most common adverse events were nausea, malaise, decreased appetite, and vomiting. Five patients (50%) reported adverse events that were considered causally related to imaradenant; three patients had Grade 2 adverse events of malaise, nausea, and diarrhea. No deaths or serious adverse events occurred. The median times of maximum observed concentrations sampled after a single dose in the 50- and 75-mg QD cohorts were 1.08 h (range, 0.95-1.95) and 2.00 h (range, 0.92-5.52), respectively. There was little accumulation after multiple dosing, with geometric mean accumulation ratios of maximum concentration of 1.3 (50-mg QD) to 1.4 (75-mg QD) and area under the concentration-time curve 0-24 of 1.4 (50-mg QD) to 1.5 (75-mg QD). The best objective response was stable disease (3/10).

CONCLUSION

No new or unexpected safety concerns were identified, and imaradenant had an acceptable safety profile at both 50- and 75-mg QD.

CLINICALTRIALS

gov identifier NCT03980821 (June 10, 2019).

A phase 2 study of AZD4635 in combination with durvalumab or oleclumab in patients with metastatic castration-resistant prostate cancer

BACKGROUND

Inhibition of the adenosine 2A receptor (A2AR) diminishes the immunosuppressive effects of adenosine and may complement immune-targeting drugs. This phase 2 study evaluated the A2AR antagonist AZD4635 in combination with durvalumab or oleclumab in patients with metastatic castration-resistant prostate cancer.

METHODS

Patients with histologically/cytologically confirmed disease progressing within 6 months on ≥ 2 therapy lines were randomly assigned to either Module 1 (AZD4635 + durvalumab) or Module 2 (AZD4635 + oleclumab). Primary endpoints were objective response rate per RECIST v1.1 and prostate-specific antigen (PSA) response rate. Secondary endpoints included radiological progression-free survival (rPFS), overall survival, safety, and pharmacokinetics.

RESULTS

Fifty-nine patients were treated (Module 1, n = 29; Module 2, n = 30). Median number of prior therapies was 4. One confirmed complete response by RECIST (Module 1) and 2 confirmed PSA responses (1 per module) were observed. The most frequent adverse events (AEs) possibly related to AZD4635 were nausea (37.9%), fatigue (20.7%), and decreased appetite (17.2%) in Module 1; nausea (50%), fatigue (30%), and vomiting (23.3%) in Module 2. No dose-limiting toxicities or treatment-related serious AEs were observed. In Module 1, AZD4635 geometric mean trough concentration was 124.9 ng/mL (geometric CV% 69.84; n = 22); exposures were similar in Module 2. In Modules 1 and 2, median (95% CI) rPFS was 2.3 (1.6 -3.8) and 1.5 (1.3- 4.0) months, respectively. Median PFS was 1.7 versus 2.3 months for patients with high versus low blood-based adenosine signature.

CONCLUSION

In this heavily pretreated population, AZD4635 with durvalumab or oleclumab demonstrated minimal antitumor activity with a manageable safety profile.

CLINICAL TRIAL

gov identifier: NCT04089553.

Biomarker-directed targeted therapy plus durvalumab in advanced non-small-cell lung cancer: a phase 2 umbrella trial

For patients with non-small-cell lung cancer (NSCLC) tumors without currently targetable molecular alterations, standard-of-care treatment is immunotherapy with anti-PD-(L)1 checkpoint inhibitors, alone or with platinum-doublet therapy. However, not all patients derive durable benefit and resistance to immune checkpoint blockade is common. Understanding mechanisms of resistance-which can include defects in DNA damage response and repair pathways, alterations or functional mutations in STK11/LKB1, alterations in antigen-presentation pathways, and immunosuppressive cellular subsets within the tumor microenvironment-and developing effective therapies to overcome them, remains an unmet need. Here the phase 2 umbrella HUDSON study evaluated rational combination regimens for advanced NSCLC following failure of anti-PD-(L)1-containing immunotherapy and platinum-doublet therapy. A total of 268 patients received durvalumab (anti-PD-L1 monoclonal antibody)-ceralasertib (ATR kinase inhibitor), durvalumab-olaparib (PARP inhibitor), durvalumab-danvatirsen (STAT3 antisense oligonucleotide) or durvalumab-oleclumab (anti-CD73 monoclonal antibody). Greatest clinical benefit was observed with durvalumab-ceralasertib; objective response rate (primary outcome) was 13.9% (11/79) versus 2.6% (5/189) with other regimens, pooled, median progression-free survival (secondary outcome) was 5.8 (80% confidence interval 4.6-7.4) versus 2.7 (1.8-2.8) months, and median overall survival (secondary outcome) was 17.4 (14.1-20.3) versus 9.4 (7.5-10.6) months. Benefit with durvalumab-ceralasertib was consistent across known immunotherapy-refractory subgroups. In ATM-altered patients hypothesized to harbor vulnerability to ATR inhibition, objective response rate was 26.1% (6/23) and median progression-free survival/median overall survival were 8.4/22.8 months. Durvalumab-ceralasertib safety/tolerability profile was manageable. Biomarker analyses suggested that anti-PD-L1/ATR inhibition induced immune changes that reinvigorated antitumor immunity. Durvalumab-ceralasertib is under further investigation in immunotherapy-refractory NSCLC.ClinicalTrials.gov identifier: NCT03334617.

Phase Ia/b, Open-Label, Multicenter Study of AZD4635 (an Adenosine A2A Receptor Antagonist) as Monotherapy or Combined with Durvalumab, in Patients with Solid Tumors

PURPOSE

To evaluate AZD4635, an adenosine A2A receptor antagonist, as monotherapy or in combination with durvalumab in patients with advanced solid tumors.

PATIENTS AND METHODS

In phase Ia (dose escalation), patients had relapsed/refractory solid tumors; in phase Ib (dose expansion), patients had checkpoint inhibitor-naïve metastatic castration-resistant prostate cancer (mCRPC) or colorectal carcinoma, non-small cell lung cancer with prior anti-PD-1/PD-L1 exposure, or other solid tumors (checkpoint-naïve or prior anti-PD-1/PD-L1 exposure). Patients received AZD4635 monotherapy (75-200 mg once daily or 125 mg twice daily) or in combination with durvalumab (AZD4635 75 or 100 mg once daily). The primary objective was safety; secondary objectives included antitumor activity and pharmacokinetics; exploratory objectives included evaluation of an adenosine gene signature in patients with mCRPC.

RESULTS

As of September 8, 2020, 250 patients were treated (AZD4635, n = 161; AZD4635+durvalumab, n = 89). In phase Ia, DLTs were observed with monotherapy (125 mg twice daily; n = 2) and with combination treatment (75 mg; n = 1) in patients receiving nanosuspension. The most common treatment-related adverse events included nausea, fatigue, vomiting, decreased appetite, dizziness, and diarrhea. The RP2D of the AZD4635 capsule formulation was 75 mg once daily, as monotherapy or in combination with durvalumab. The pharmacokinetic profile was dose-proportional, and exposure was adequate to cover target with 100 mg nanosuspension or 75 mg capsule once daily. In patients with mCRPC receiving monotherapy or combination treatment, tumor responses (2/39 and 6/37, respectively) and prostate-specific antigen responses (3/60 and 10/45, respectively) were observed. High versus low blood-based adenosine signature was associated with median progression-free survival of 21 weeks versus 8.7 weeks.

CONCLUSIONS

AZD4635 monotherapy or combination therapy was well tolerated. Objective responses support additional phase II combination studies in patients with mCRPC.

Abstract 390: Identification of a novel immunosuppressive myeloid gene expression signature for clinical biomarker development

Cell-type abundance GE signatures are useful for informing drug mechanism of action and may be useful in-patient selection for cancer immunotherapies. Recently, we validated natural killer cell- and dendritic cell-type specific expression signatures using a tiered strategy that included both computational and ex vivo validation. Here, we built upon this strategy to validate expression signatures for immunosuppressive myeloid cells (IMC). IMC play a critical role in impairing anti-tumor immunity and increased levels of peripheral IMC have been associated with advanced tumor progression and poor prognosis in various cancers. However, their low abundance in normal tissues and heterogeneous surface expression render their profiling difficult. To address this, we focused on validating GE signatures for IMC abundance using mRNA expression methods which are more clinically tractable than established flow cytometry methods that require intact cells.

We implemented a three-stage GE signature validation strategy. First, we generated GE data from human ex vivo differentiated IMC (LIN- CD11B+ CD33+ HLADR-). Then, we evaluated the concordance of 16 previously published myeloid signatures with cell type abundance in a series of spike-ins with varying but known quantities of ex vivo differentiated IMC in a background of undifferentiated peripheral blood mononuclear cells (PBMCs). Gene-set variation analysis (GSVA) was used to score the signatures and Spearman's rank (rS) correlation coefficient was calculated to assess the significance of correlations between GSVA scores and IMC abundance. With this method, we validated 3 of the 16 published myeloid signatures (1. MacB3/PMID:26873985 (rS = 0.87; p = 8.8e-07); 2. MacB2_3w/PMID:26873985 (rS = 0.83; p = 6.7e-06); 3. TAM/PMID:27424807 (rS = 0.80; p= 2.6e-05)).

Next, we generated a ‘de novo' signature by performing differential GE analysis and identified up-regulated genes in IMC in comparison to PBMCs with log2 fold change &gt 2, p-adj &lt 0.05). We further refined this list by selecting genes with significant concordance to IMC abundance (rS &gt 0.80, p-adj &lt 0.05) and confirmed their specificity to IMC in published scRNAseq studies [PMID: 30979687; 31033233; 32302573]. This led to a 6-gene ‘de novo' signature (MRC1, APOE, C1QA, C1QB, MMP9, SPP1) associated with IMC function with highly significant concordance (rS = 0.96; p = 1.2e-11) to IMC abundance.

Lastly, we showed that in whole blood baseline samples from HNSCC patients (n=53) treated with danvatirsen + durvalumab [NCT02499328], our ‘de novo' signature was significantly elevated (p=0.033) in patients with progressive disease compared to complete responders. Application to additional studies will be required to more fully determine its clinical utility.

Citation Format: Srimathi S. Srinivasan, Gozde Kar, Deanna L. Russell, Peter Gathungu, Minoo Rafati, David Whitston, Grant Duclos, Ben Sidders, J Carl Barrett, Tim Slidel, Patricia McCoon. Identification of a novel immunosuppressive myeloid gene expression signature for clinical biomarker development [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 390.

Adenosine Signaling Is Prognostic for Cancer Outcome and Has Predictive Utility for Immunotherapeutic Response

PURPOSE

There are several agents in early clinical trials targeting components of the adenosine pathway including A2AR and CD73. The identification of cancers with a significant adenosine drive is critical to understand the potential for these molecules. However, it is challenging to measure tumor adenosine levels at scale, thus novel, clinically tractable biomarkers are needed.

EXPERIMENTAL DESIGN

We generated a gene expression signature for the adenosine signaling using regulatory networks derived from the literature and validated this in patients. We applied the signature to large cohorts of disease from The Cancer Genome Atlas (TCGA) and cohorts of immune checkpoint inhibitor-treated patients.

RESULTS

The signature captures baseline adenosine levels in vivo (r ² = 0.92, P = 0.018), is reduced after small-molecule inhibition of A2AR in mice (r ² = -0.62, P = 0.001) and humans (reduction in 5 of 7 patients, 70%), and is abrogated after A2AR knockout. Analysis of TCGA confirms a negative association between adenosine and overall survival (OS, HR = 0.6, P < 2.2e^-16) as well as progression-free survival (PFS, HR = 0.77, P = 0.0000006). Further, adenosine signaling is associated with reduced OS (HR = 0.47, P < 2.2e^-16) and PFS (HR = 0.65, P = 0.0000002) in CD8⁺ T-cell-infiltrated tumors. Mutation of TGFβ superfamily members is associated with enhanced adenosine signaling and worse OS (HR = 0.43, P < 2.2e^-16). Finally, adenosine signaling is associated with reduced efficacy of anti-PD1 therapy in published cohorts (HR = 0.29, P = 0.00012).

CONCLUSIONS

These data support the adenosine pathway as a mediator of a successful antitumor immune response, demonstrate the prognostic potential of the signature for immunotherapy, and inform patient selection strategies for adenosine pathway modulators currently in development.

Tissue-specific progesterone receptor-chromatin binding and the regulation of progesterone-dependent gene expression

Progesterone receptor (PGR) co-ordinately regulates ovulation, fertilisation and embryo implantation through tissue-specific actions, but the mechanisms for divergent PGR action are poorly understood. Here we characterised PGR activity in mouse granulosa cells using combined ChIP-seq for PGR and H3K27ac and gene expression microarray. Comparison of granulosa, uterus and oviduct PGR-dependent genes showed almost complete tissue specificity in PGR target gene profiles. In granulosa cells 82% of identified PGR-regulated genes bound PGR within 3 kb of the gene and PGR binding sites were highly enriched in proximal promoter regions in close proximity to H3K27ac-modified active chromatin. Motif analysis showed highly enriched PGR binding to the PGR response element (GnACAnnnTGTnC), but PGR also interacted significantly with other transcription factor binding motifs. In uterus PGR showed far more tendency to bind intergenic chromatin regions and low evidence of interaction with other transcription factors. This is the first genome-wide description of PGR action in granulosa cells and systematic comparison of diverse PGR action in different reproductive tissues. It clarifies finely-tuned contextual PGR-chromatin interactions with implications for more targeted reproductive medicine.

Hematopoietic Stem Cell-derived Adipocytes Promote Tumor Growth and Cancer Cell Migration

Adipocytes, apart from their critical role as the energy storage depots, contribute to the composition of the tumor microenvironment. Our previous studies based on a single hematopoietic stem cell (HSC) transplantation model, have revealed a novel source of adipocytes from HSCs via monocyte/macrophage progenitors. Herein, we extend these studies to examine the role of HSC-derived adipocytes (HSC-Ad) in tumor progression. When cultured under adipogenic conditions, bone marrow-derived monocytic progenitors differentiated into adipocytes that accumulated oil droplets containing triglyceride. The adipokine array and ELISAs confirmed secretion of multiple adipokines by HSC-Ad. These adipocytes underwent further development in vivo when injected subcutaneously into C57Bl/6 mice. When co-injected with melanoma B16F1 cells or breast cancer E0771 cells into syngeneic C57Bl/6 mice, HSC-Ad not only accelerated both melanoma and breast tumor growth, but also enhanced vascularization in both tumors. Conditioned media from HSC-Ad supported B16F1 and E0771 cell proliferation and enhanced cell migration in vitro. Among the HSC-Ad secreted adipokines, insulin-like growth factor 1 (IGF-1) played an important role in E0771 cell proliferation. Hepatocyte growth factor (HGF) was indispensable for B16F1 cell migration, whereas HGF and platelet-derived growth factor BB (PDGF-BB) collectively contributed to E0771 cell migration. Expression levels of receptors for IGF-1, HGF, and PDGF-BB correlated with their differential roles in B16F1 and E0771 cell proliferation and migration. Our data suggest that HSC-Ad differentially regulate tumor behavior through distinct mechanisms.

Abstract 574: AGS62P1, a novel site-specific antibody drug conjugate targeting FLT3 exhibits potent anti-tumor activity regardless of FLT3 kinase activation status

FLT3 is a member of the class III receptor tyrosine kinase family that includes C-KIT, C-FMS and platelet derived growth factor receptor (PDGFR). FLT3 is primarily expressed in early myeloid and lymphoid progenitors and plays an important role in their proliferation and differentiation. In human leukemia, FLT3 is expressed on 70-90% acute myeloid leukemia (AML) and most B-acute lymphoblastic leukemia (B-ALL). FLT3 genetic aberrations are commonly detected in patients with AML. The most common aberration is internal tandem duplication (ITD), which occurs in 25-30% of AML patients and causes constitutive activation of FLT3. Point mutation in codon D835 of the FLT3 tyrosine kinase domain is reported in 7-10% of AML patients and also causes constitutive activation of the receptor. FLT3 small molecule inhibitors targeting the kinase domain are predominantly active against FLT3 activated AML. The restricted normal tissue expression profile and higher differential in leukemic specimens makes FLT3 amenable to antibody-based therapeutics, requiring only target expression independent of kinase activation status. Therefore, development of an antibody-drug conjugate (ADC) may provide a therapeutic alternative for AML patients.

Here, we report the development of the first FLT3specific ADC, AGS62P1, employing site-specific conjugation using the non-natural amino acid, p-acetyl phenylalanine (pAF). AGS62P1 comprises a human gamma one antibody including an inserted pAF residue in each of the heavy chains. The antibody was conjugated to a potent cytotoxic payload via an oxime bond at the pAF sites, thus creating a nearly homogeneous drug distribution, with approximately 2 drug molecules per antibody. Strong binding affinity (0.1-0.9 nM) and potent in vitro cytotoxic activity (IC50 = 0.2-12 nM) was achieved in AML cell lines. The anti-FLT3 ADC was highly efficacious in AML tumor xenografts, leading to statistically significant tumor growth inhibition of both FLT3 ITD and non-ITD models. Additional characterization of both the antibody and ADC was performed, including ligand receptor interaction, degradation, internalization, and apoptosis.

In summary, we have developed a site-specific ADC targeting FLT3 that exhibits potent anti-tumor activity in xenograft models regardless of FLT3 activation status. This drug can potentially offer a new and more versatile approach in targeting FLT3-expressing leukemia through a mechanism independent of FLT3 genetic aberration.

Citation Format: Nandini Rudra-Ganguly, Pia M. Challita-Eid, Christine Lowe, Mike Mattie, Sung-Ju Moon, Brian A. Mendelsohn, Monica Leavitt, Cyrus Virata, Alla Verlinsky, Linnette Capo, Mi Sook Chang, Deanna L. Russell, Baljinder Randhawa, Gao Liu, René Hubert, Mary Brodey, Hector Aviña, Chunying Zhang, Joseph D. Abad, Banmeet Anand, Sher Karki, Zili An, Roland Luethy, Fernando Doñate, Daniel S. Pereira, Kendall Morrison, Ingrid B.J. Joseph, David R. Stover. AGS62P1, a novel site-specific antibody drug conjugate targeting FLT3 exhibits potent anti-tumor activity regardless of FLT3 kinase activation status. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 574.

Correction: X-Ray fluorescence imaging and other analyses identify selenium and GPX1 as important in female reproductive function

Correction for 'X-Ray fluorescence imaging and other analyses identify selenium and GPX1 as important in female reproductive function' by M. J. Ceko et al., Metallomics, 2014, DOI: .

X-Ray fluorescence imaging and other analyses identify selenium and GPX1 as important in female reproductive function

Studies of selenium (Se) status indicate that Se is necessary for fertility but how precisely is not known. We aimed to show that Se was important in bovine female reproductive function. The elemental distribution in the bovine ovary (n = 45 sections) was identified by X-ray fluorescence (XRF) imaging. Se was consistently localized to the granulosa cell layer of large (>10 mm) healthy follicles. Inductively Coupled Plasma - Mass Spectrometry revealed tenfold higher Se in the bovine follicle wall compared to corpora lutea. Gene expression analysis of selenoprotein genes GPX1, GPX3, VIMP and SELM in bovine granulosa cells revealed that only GPX1 was significantly up-regulated in large healthy follicles compared to the small healthy or atretic follicles (P < 0.05). Western immunoblotting identified GPX1 protein in bovine granulosa cells of large healthy follicles, but not of small healthy follicles. To assess if GPX1 was important in human follicles, cumulus cells from women undergoing IVF/ICSI with single embryo transfer were collected. Oocytes and embryos were cultured and transferred independently in 30 patients undergoing elective single embryo transfer. Gene expression of GPX1 was significantly higher in human cumulus cells from cumulus-oocyte complexes yielding a pregnancy (P < 0.05). We present the first XRF imaging of mammalian ovaries showing that Se is consistently localized to the granulosa cells of large healthy follicles. We conclude that Se and selenoproteins are elevated in large healthy follicles and may play a critical role as an antioxidant during late follicular development.

Blood and lymphatic vasculature in the ovary: development, function and disease

BACKGROUND

The remodelling of the blood vasculature has been the subject of much research while rapid progress in the understanding of the factors controlling lymphangiogenesis in the ovary has only been reported more recently. The ovary undergoes cyclic remodelling throughout each menstrual/estrous cycle. This process requires significant vascular remodelling to supply each new cohort of growing follicles.

METHODS

Literature searches were performed to review studies on the ovarian lymphatic vasculature that described spatial, temporal and functional data in human or animal species. The role of ovarian blood and lymphatic vasculature in the pathogenesis of ovarian disease and dysfunction was also explored.

RESULTS

Research in a number of species including zebrafish, rodents and primates has described the lymphatic vasculature within the remodelling ovary, while recent research in mouse has confirmed hormonal regulation of lymphangiogenic growth factors, their receptors and also a role for the protease, ADAMTS1 in the development of the lymphatic vasculature. With a critical role in the maintenence of fluid homeostasis, the ovarian lymphatic vasculature is important for normal ovarian function and has been linked to syndromes involving ovarian fluid imbalance, including ovarian hyperstimulation syndrome and massive ovarian edema. The lymphatic vasculature has also been heavily implicated in the metastatic cancer process.

CONCLUSION

The spatial and temporal regulation of the ovarian lymphatic vasculature has now been reported in a number of species and the data also implicate the ovarian lymphatic vasculature in ovarian pathologies, including cancer and those linked with use of artificial reproduction technologies.

Suppressor of cytokine signaling 4 (SOCS4): moderator of ovarian primordial follicle activation

Mammalian ovarian primordial follicle activation and regulation is considered as one of the most important stages of folliculogenesis and as such requires exquisite control. Selection of quiescent follicles to enter the growing pool determines the rate of supply of maturing follicles over the female reproductive lifespan. To coordinate this process a range of positive and negative input signals contribute to determine follicle fate. This study demonstrates that the cytokine Leukemia Inhibitory Factor (LIF) activates the Janus Kinase 1/Signal Transducers and Activators of Transcription 3 (JAK1/STAT3) signaling pathway in pre-granulosa cells and positively regulates primordial follicle activation. Negative regulation of the JAK/STAT pathway is controlled by the suppressor of cytokine signaling 4 (SOCS4) protein, which target members of negative feedback loops, Cardiotrophin like Cytokine (CLC), Poly (rC) Binding Protein 1 (PCBP1), and Cytosolic Malate Dehydrogenase (MDH1) to suppress follicle growth and development.

Outcomes of colonization with MRSA and VRE among liver transplant candidates and recipients

Methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococcus (VRE) infections cause significant morbidity and mortality among liver transplant candidates and recipients. To assess rates of MRSA and VRE colonization, we obtained active surveillance cultures from 706 liver transplant candidates and recipients within 24 h of admission to an 11-bed liver transplant ICU from October 2000 to December 2005. Patients were followed prospectively to determine the cumulative risk of MRSA or VRE infection or death by colonization status. Outcomes were assessed by Kaplan-Meier survival analysis and Cox regression and multivariate logistic regression adjusting for covariates. The prevalence of newly detected MRSA nasal and VRE rectal colonization was 6.7% and 14.6%, respectively. Liver transplant candidates and recipients with MRSA colonization had an increased risk of MRSA infection (adjusted OR = 15.64, 95% CI 6.63-36.89) but not of death (adjusted OR = 1.00, 95% CI 0.43-2.30), whereas those with VRE colonization had an increased risk both of VRE infection (adjusted OR = 3.61, 95% CI 2.01-6.47) and of death (adjusted OR = 2.12, 95% CI 1.27-3.54) compared with noncolonized patients. Prevention and control strategies, including use of active surveillance cultures, should be implemented to reduce the rates of both MRSA and VRE colonization in this high-risk patient population.

Oxygen concentration during mouse oocyte in vitro maturation affects embryo and fetal development

BACKGROUND

Little is known of how the oxygen environment in the ovarian follicle affects oocyte and embryo development, but this has an important impact on the conditions used for in vitro maturation (IVM) of oocytes. We investigated the effect of varying oxygen concentrations during IVM on subsequent pre and post-implantation development.

METHODS

IVM of mouse cumulus-oocyte complexes (COCs) was performed under 2, 5, 10 or 20% O(2) (6% CO(2), balance N(2)). In vivo-matured COCs were collected post ovulation. Embryos were generated by IVF and culture. Blastocyst development, cell number and apoptosis were assessed, and fetal and placental outcomes analysed following embryo transfer at day 18 of pregnancy.

RESULTS

Oxygen concentration during IVM did not affect oocyte maturation or subsequent fertilization, cleavage and blastocyst development rates. Maturation of oocytes under 2% O(2) increased blastocyst trophectoderm cell number compared with all groups and numbers at 5% were higher than 20% (both P < 0.05). Percentage of apoptotic cells was increased in blastocysts developed from 2% O(2)-matured oocytes, compared with maturation at 5% O(2) or in vivo (P < 0.05). Rates of embryo implantation and development into a viable fetus were not altered by IVM oxygen. However, fetal weight was reduced following oocyte maturation at 5% O(2) compared wiht 20% O(2) and maturation at 5% O(2) also reduced placental weight, when compared with in vivo-matured oocytes (both P < 0.05).

CONCLUSIONS

Level of O(2) exposure during oocyte maturation can alter the cellular composition of blastocysts, but these changes in cell number do not correlate with the altered fetal and placental outcomes after transfer.

TBC1D1 is a candidate for a severe obesity gene and evidence for a gene/gene interaction in obesity predisposition

The molecular etiology of obesity predisposition is largely unknown. Here, we present evidence that genetic variation in TBC1D1 confers risk for severe obesity in females. We identified a coding variant (R125W) in TBC1D1 that segregated with the disease in 4p15-14-linked obesity pedigrees. In cases derived from pedigrees with the strongest linkage evidence, the variant was significantly associated with obesity (P=0.000007) and chromosomes carrying R125W accounted for the majority of the evidence that originally linked 4p15-14 with the disease. In addition, by selecting families that segregated R125W with obesity, we were able to generate highly significant linkage evidence for an obesity predisposition locus at 4q34-35. This result provides additional and confirming evidence that R125W affects obesity susceptibility, delimits the location of an obesity gene at 4q34-35 and identifies a gene/gene interaction that influences the risk for obesity predisposition. Finally, although the function of TBC1D1 is unknown, the protein is structurally similar to a known regulator of insulin-mediated Glut4 translocation.

Adamts-1 Is Essential for the Development and Function of the Urogenital System1

Successful ovulation and implantation processes play a crucial role in female fertility. Adamts-1, a matrix metalloproteinase with disintegrin and thrombospondin motifs, has been suggested to be regulated by the progesterone receptor in the hormonal pathway leading to ovulation. With the primary aim of investigating the role of Adamts-1 in female fertility, we generated Adamts-1 null mice. Forty-five percent of the newborn Adamts-1 null mice die, with death most likely caused by a kidney malformation that becomes apparent at birth. Surviving female null mice were subfertile, whereas males reproduced normally. Ovulation in null females was impaired because of mature oocytes remaining trapped in ovarian follicles. No uterine phenotype was apparent in Adamts-1 null animals. Embryo implantation occurred normally, the uteri were capable of undergoing decidualization, and no morphological changes were observed. These results demonstrate that a functional Adamts-1 is required for normal ovulation to occur, and hence the Adamts-1 gene plays an important role in female fertility, primarily during the tissue remodeling process of ovulation.

Predisposition locus for major depression at chromosome 12q22-12q23.2

Major depression disorder is a common psychiatric disease with a major economic impact on society. In many cases, no effective treatment is available. The etiology of major depression is complex, but it is clear that the disease is, to a large extent, determined genetically, especially among individuals with a familial history of major depression, presumably through the involvement of multiple predisposition genes in addition to an environmental component. As a first step toward identification of chromosomal loci contributing to genetic predisposition to major depression, we have conducted a genomewide scan by using 628 microsatellite markers on 1,890 individuals from 110 Utah pedigrees with a strong family history of major depression. We identified significant linkage to major depression in males at marker D12S1300 (multipoint heterogeneity LOD score 4.6; P=.00003 after adjustment for multiple testing). With additional markers, the linkage evidence became highly significant, with the multipoint heterogeneity LOD score at marker D12S1706 increasing to 6.1 (P=.0000007 after adjustment for multiple testing). This study confirms the presence of one or more genes involved in psychiatric diseases on the q arm of chromosome 12 and provides strong evidence for the existence of a sex-specific predisposition gene to major depression at 12q22-q23.2.

Regulation of transcripts encoding ADAMTS-1 (a disintegrin and metalloproteinase with thrombospondin-like motifs-1) and progesterone receptor by human chorionic gonadotropin in equine preovulatory follicles

One member of a new family of metalloproteinases, a disintegrin and metalloproteinase with thrombospondin-like motifs-1 (ADAMTS-1), has been found to be expressed and hormonally induced in granulosa cells of ovulating rodent follicles. Furthermore, the targeted disruption of the ADAMTS-1 gene resulted in ovarian defects associated with severely impaired fertility. While these data demonstrate the importance of ADAMTS-1 in rodent ovarian physiology, the potential role of ADAMTS-1 in the ovulatory process of monoovulatory species remains unknown. The objectives of this study were to clone the equine ADAMTS-1 primary transcript and to study its regulation during human chorionic gonadotropin (hCG)-induced ovulation. A 3573 bp follicular cDNA library clone was isolated and found to encode a nearly complete, highly conserved ADAMTS-1 homologue. Real-time RT-PCR analysis detected this transcript in diverse tIssues, including previously unreported sites of ADAMTS-1 expression such as the male reproductive tract, the follicular theca interna and the mature corpus luteum. The tIssue distribution of the progesterone receptor (PR), a known regulator of ADAMTS-1 expression in rodent preovulatory follicles, was found to overlap that of ADAMTS-1 in some tIssues. A study of the regulation of follicular ADAMTS-1 and PR mRNAs during the hCG-induced ovulatory process revealed distinct patterns of regulation in granulosa cells and in theca interna. In granulosa cells, ADAMTS-1 mRNA was found to be induced at 12 h post-hCG (P<0.05), followed by a return to basal levels by 30 h and a re-increase at 33-39 h (P<0.05). A concomitant increase in PR mRNA (P<0.05) was observed at 12 h post-hCG. In theca interna, abundant ADAMTS-1 mRNA was detected at all timepoints, and levels increased transiently at 33 h post-hCG (P<0.05), whereas no significant change was observed in PR mRNA. Together, these data demonstrate for the first time the hormonally regulated ovarian expression of ADAMTS-1 in a monoovulatory species, and identify a novel biphasic regulation of ADAMTS-1 in granulosa cells and a regulated expression in theca interna that were not previously observed in rodents.

A major predisposition locus for severe obesity, at 4p15-p14

Although the predisposition to morbid obesity is heritable, the identities of the disease-causing genes are largely unknown. Therefore, we have conducted a genomewide search with 628 markers, using multigenerational Utah pedigrees to identify genes involved in predisposition to obesity. In the genomewide search, we identified a highly significant linkage to high body-mass index in female patients, at D4S2632, with a multipoint heterogeneity LOD (HLOD) score of 6.1 and a nonparametric linkage (NPL) score of 5.3. To further delineate the linkage, we increased both the marker density around D4S2632 and the size of our pedigree data set. As a result, the linkage evidence increased to a multipoint HLOD score of 9.2 (at D4S3350) and an NPL score of 11.3. Evidence from almost half of the families in this analysis support this linkage, and therefore the gene in this region might account for a significant percentage of the genetic predisposition to severe obesity in females. However, further studies are necessary to clarify the effect that this gene has in males and in the general population.

The relation between skeletal maturation and adiposity in African American and Caucasian children

OBJECTIVE

African American children have earlier pubertal and skeletal maturation and a higher body mass index (BMI) than Caucasian children. We tested the hypothesis that advanced bone age in African American children is accounted for by their greater adiposity.

STUDY DESIGN

We studied 252 African American (n = 97) and Caucasian (n = 155) children aged 5 to 12 years. Skeletal age was determined by a radiologist blinded to clinical details. The difference between bone age (BA) and chronological age (CA) (noted as BA - CA) and the ratio of bone age to chronological age (BA/CA) were determined. Analysis of covariance was used to adjust skeletal maturation for the effects of adiposity, as measured by BMI, BMI standard deviation score (BMI SDS), and fat mass by dual energy x-ray absorptiometry (DXA).

RESULTS

African American children were significantly heavier than Caucasians (BMI SDS 2.7 +/- 3.4 vs 1.7 +/- 2.4, P <.05). Both BA - CA (0.75 +/- 1.46 vs 0.28 +/- 1.38, P <.05) and BA/CA (1.09 +/- 0.17 vs 1.03 +/- 0.16, P <.05) were significantly greater in African Americans than Caucasians. BA - CA and BA/CA were significantly correlated with lean body mass, BMI, BMI SDS, and DXA fat mass (all r > 0.46, P <.001). Neither BA - CA nor BA/CA of African Americans and Caucasians were significantly different after correction for lean body mass and measures of adiposity, including BMI, BMI SDS, or DXA fat mass.

CONCLUSION

Skeletal age is more advanced in African American than Caucasian children and is significantly related to body mass. In large measure, the advancement in skeletal maturation of prepubertal and early pubertal African American children can be accounted for by their greater adiposity.

Estimation of body fatness by air displacement plethysmography in African American and white children

The purpose of this study was to determine the ability of air displacement plethysmography (ADP) to estimate body fatness in prepubertal and early pubertal African American and white children. One hundred nineteen nonoverweight and overweight boys (N = 56) and girls (N = 63), age (mean +/- SD) 9.8 +/- 1.7 y, body mass index 25.9 +/- 7.6 kg/m2 (range, 14.2-47.0 kg/m2), and mean percent body fat (%BF) by dual-energy x-ray absorptiometry (DXA) 39.2 +/- 11.7% (range, 12.2-57.5%), were studied. %BF by ADP was compared with DXA %BF estimates and with body fat by several field methods: skinfold thicknesses using the Slaughter et al. equations (Hum Biol 60: 709-723, 1988), bioelectrical impedance analysis (BIA) using the Houtkooper et al. equation (J Appl Physiol 72: 366-373, 1992), and a predictive equation using skinfold thicknesses, BIA, and weight (Goran et al.: Am J Clin Nutr 63: 299-305, 1996). All methods used to estimate %BF were significantly correlated with DXA (all p < 0.0001), with r2 ranging from 0.85 (skinfold measurements) to 0.95 (ADP). ADP using the Siri equation underestimated %BF by -1.9% (p < 0.001); the Bland-Altman limits of agreement (defined as +/-2 SD) were +/-7.4%. %BF by ADP-Siri underestimated %BF by DXA by 3.0% for girls (p < 0.001) and by 0.6% for boys (NS). Agreement between body fat estimation by ADP and DXA did not vary with age, race, or pubertal stage. Application of the age-adjusted Lohman model to ADP significantly increased the magnitude of the underestimation to -6.9% (p < 0.0001). Prediction of %BF by the Slaughter skinfold thickness equation showed no significant mean bias for the overall data, but significantly underestimated %BF in girls (-3.7%) while overestimating %BF in boys (+2.4%) with wide limits of agreement (+/-17.7%, p < 0.01 versus ADP). %BF by the Houtkooper BIA equation or Goran model underestimated %BF to a significantly greater degree than ADP (Houtkooper, -8.1%; Goran, -10.1%; both p < 0.0001 versus DXA or ADP). Determination of %BF from ADP using the Siri model slightly underestimates %BF as determined by DXA in girls, but appears to be superior to existing field methods both in accuracy and limits of agreement. Because of the ease with which it can be performed, ADP may prove useful for investigations of adiposity in children.

Linkage of body mass index to chromosome 20 in Utah pedigrees

Several linkage studies have hinted at the existence of an obesity predisposition locus on chromosome 20, but none of these studies has produced conclusive results. Therefore, we analyzed 48 genetic markers on chromosome 20 for linkage to severe obesity (BMI> or =35) in 103 extended Utah pedigrees (1,711 individuals), all of which had strong aggregation of severe obesity. A simple dominant model produced a maximum multipoint heterogeneity LOD score of 3.5 at D20S438 (55.1 cM). Two additional analyses were performed. First, a one-gene, two-mutation model (with one dominant mutation and one recessive mutation) increased the LOD score to 4.2. Second, a two-locus model (with one locus dominant and one recessive) generated a multipoint LOD score of 4.9. We conclude that one or more severe obesity predisposing genes lie within an interval of approx. 10 cM on chromosome 20. This study generated significant LOD scores which confirm suggestive linkage reports from previous studies. In addition, our analyses suggest that the predisposing gene(s) is localized very near the chromosome 20 centromere.

Relation of acanthosis nigricans to hyperinsulinemia and insulin sensitivity in overweight African American and white children

OBJECTIVES

Acanthosis nigricans (AN) has been proposed as a reliable marker of hyperinsulinemia, but its utility for predicting hyperinsulinism has not been systematically evaluated in overweight children. We examined the relationship of AN to hyperinsulinemia and body adiposity.

STUDY DESIGN

One hundred thirty-nine children underwent physical examination for AN, body composition studies, an oral glucose tolerance test, and a hyperglycemic clamp.

RESULTS

Thirty-five children (25%) had AN. AN was more prevalent in African Americans (50.1%) than in white subjects (8.2%, P < .001). Independent of race, children with AN had greater body weight and body fat mass (P < .001); greater basal and glucose-stimulated insulin levels during oral glucose tolerance test (P < .001); greater first-phase, second-phase, and steady-state insulin levels (P < .001); and lower insulin sensitivity (P < .001) during the hyperglycemic clamp. After adjusting for body fat mass and age, none of these differences remained significant. When categorized by fasting insulin, 35% with fasting insulin levels > 20 microU/mL and 50% with fasting insulin levels > 15 microU/mL did not have AN. Eighty-eight percent of children with fasting insulin levels > or = 15 microU/mL had a body mass index SD score > or = 3.0.

CONCLUSIONS

AN is not a reliable marker for hyperinsulinemia in overweight children. Children with a race-, sex-, and age-specific body mass index SD scores > or = 3.0 should be screened for hyperinsulinemia, whether or not they have AN.

Expression of tumor necrosis factor-stimulated gene-6 in the rat ovary in response to an ovulatory dose of gonadotropin

Current evidence supports the hypothesis that the biochemical events of mammalian ovulation are analogous to an acute inflammatory reaction. This study reveals that tumor necrosis factor-stimulated gene-6 (TSG-6), which encodes a member of the superfamily of hyaluronan-binding proteins that is specifically translated in inflammatory reactions, is expressed in ovarian follicles that have been induced to ovulate. Immature Wistar rats were primed with 10 IU equine CG s.c.; and 48 h later, the 12-h ovulatory process was initiated by 10 IU human CG (hCG), s.c.. Ovarian RNA was extracted at 0, 2, 4, 8, 12, and 24 h after the primed animals were injected with hCG. The RNA extracts were used for RT-PCR differential display of amplified complementary DNAs (cDNAs) that represented gene expression in the stimulated ovarian tissue. Northern analysis of one of the differentially amplified cDNAs confirmed that it was part of a gene that was substantially up-regulated at 4-8 h after the ovaries had been stimulated by hCG. Subcloning and sequence analysis revealed that the cDNA matched the gene for TSG-6. In situ hybridization indicated that the TSG-6 messenger RNA was primarily located in the cumulus mass and the antral granulosa cells of large ovarian follicles. In conclusion, the data show that expression of TSG-6 is an integral part of the cascade of inflammatory-like changes that occur in an ovulatory follicle in response to a trophic hormone that couples with luteinizing hormone/hCG receptors.

Expression of regulator of G-protein signaling protein-2 gene in the rat ovary at the time of ovulation

The ovulatory process in mammals begins when an endogenous surge in LH circulates to the ovary and couples with receptors in the plasma membranes of granulosa cells in mature ovarian follicles. This study provides evidence that the ovulatory stimulus includes induction of the gene for regulator of G-protein signaling protein-2 (RGS2). Immature Wistar rats were primed with 10 IU eCG s.c., and 48 h later the 12-h ovulatory process was initiated by 10 IU hCG (a homolog of LH) s.c. Ovarian RNA was extracted at 0, 2, 4, 8, 12, and 24 h after injecting the animals with hCG. The RNA extracts were used for reverse transcription-polymerase chain reaction differential display to detect gene expression in the stimulated ovarian tissue. Two of the amplified cDNAs that were upregulated within 2 h after the ovaries had been stimulated by hCG were homologous to segments of the mouse gene for RGS2. In situ hybridization indicated that the RGS2 mRNA was expressed in the granulosa layer of mature follicles. In conclusion, the gene for RGS2, which is known to regulate membrane signaling pathways, is transcribed in ovarian follicles in response to an ovulatory dose of gonadotropin.

Ovulation: a multi-gene, multi-step process

The luteinizing hormone (LH) surge initiates a cascade of proteolytic events that control ovulation. One of the genes induced by LH is the progesterone receptor (PR). Because mice with a mutant PR gene (PRKO) fail to ovulate and are infertile, we have used them as a model in which to determine PR target genes that might mediate the ovulatory process. The matrix metalloproteinases (MMPs: MMP2, MMP9, and MMP13) appear to be expressed in ovaries of PRKO mice in a manner similar to that in their wild-type littermates. However, the expression of two other types of proteases, cathepsin L (a member of the papain family) and ADAMTS-1 (A Disintegrin And Metalloproteinase with Thrombospondin-like motifs), are selectively induced in granulosa cells of preovulatory follicles by the LH surge. Maximal levels of these proteases are observed at 12-16 h after an LH surge, the time of ovulation. Furthermore, mRNAs encoding cathepsin L and ADAMTS-1 are reduced in the PRKO mice compared to their wild-type littermates. These novel observations indicate that these two proteases regulate some key step(s) controlling ovulation.

Induction of early growth response protein-1 gene expression in the rat ovary in response to an ovulatory dose of human chorionic gonadotropin

Granulosa cells in a mature ovarian follicle have an abundance of LH/hCG receptors that respond rapidly to an ovulatory surge in gonadotropins. Within minutes, membrane signal transduction sets in motion metabolic changes that lead to follicular rupture. This study provides evidence that the initial ovarian response to such an ovulatory stimulus includes induction of the immediate-early transcription factor gene for early growth response protein-1 (Egr-1). Immature Wistar rats were primed with 10 IU equine CG (eCG), sc, and 48 h later the 12-h ovulatory process was initiated by 10 IU hCG, sc. Ovarian RNA was extracted at 0, 0.5, 1, 2, 4, 8, 12, and 24 h after the primed animals were injected with hCG. The RNA extracts were used for RT-PCR differential display for random detection of gene expression in the stimulated ovarian tissue. Northern analysis of one of the differentially amplified complementary DNAs confirmed that it was part of a gene that was significantly up-regulated within 1 h after the ovaries had been stimulated by hCG. Maximum transcription was at 4 h after hCG, and expression declined to 0 h control levels by 24 h after hCG. Subcloning and sequence analysis revealed that the complementary DNA matched the gene for Egr-1. In situ hybridization indicated that the Egr-1 messenger RNA was in the granulosa layer of mature follicles. Western blotting confirmed the temporal pattern of Egr-1 expression detected by differential display, Northern analysis and in situ hybridization. The Egr-1 protein is approximately 84 kDa. In conclusion, the data show that expression of the zinc finger transcription factor Egr-1 is an early event in the cascade of inflammatory-like changes that occur in an ovulatory follicle in response to a trophic hormone.

Progesterone-regulated genes in the ovulation process: ADAMTS-1 and cathepsin L proteases

Ovulation is a precisely timed process by which a mature oocyte is released from an ovarian follicle. This process is initiated by the pituitary surge of luteinizing hormone (LH), is temporally associated with transcriptional regulation of numerous genes, and is presumed to involve the synthesis and/or activation of specific proteases that degrade the follicle wall. The progesterone receptor (PR), a nuclear receptor transcription factor, is induced in granulosa cells of preovulatory follicles in response to the LH surge and has been shown to be essential for ovulation, because mice lacking PR fail to ovulate and are infertile. Using these mice as a model in which to elucidate PR-regulated genes in the ovulation process, we show that the matrix metalloproteinases MMP-2 and MMP-9 are not targets of PR during ovulation. In contrast, two other proteases, ADAMTS-1 (A disintegrin and metalloproteinase with thrombospondin-like motifs) and cathepsin L (a lysosomal cysteine protease), are transcriptional targets of PR action. ADAMTS-1 is induced after LH stimulation in granulosa cells of preovulatory follicles and depends on PR. Cathepsin L is induced in granulosa cells of growing follicles by follicle-stimulating hormone, but the highest levels of cathepsin L mRNA occur in preovulatory follicles in response to LH in a PR-dependent manner. The identification of two regulated proteases in the ovary, together with their abnormal expression in anovulatory PR knockout mice, suggests that each plays a critical role in follicular rupture and represents a major advance in our understanding of the proteolytic events that control ovulation.

Ovarian expression of a disintegrin and metalloproteinase with thrombospondin motifs during ovulation in the gonadotropin-primed immature rat

Mammalian ovulation is a dynamic process that requires degradation of the collagenous connective tissue in the thecal layers of a mature follicle. In this reverse transcription-polymerase chain reaction differential display study, gonadotropin-primed immature rats were used to detect ovarian expression of a relatively new type of disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS-1) that is known to cleave extracellular matrix in acutely inflamed tissues. Immature Wistar rats were primed with 10 IU eCG s. c., and the temporal pattern of expression of the ADAMTS-1 gene was delineated by extracting ovarian RNA at 0, 2, 4, 8, 12, and 24 h after induction of ovulation by injecting the primed animals with 10 IU hCG s.c. The differential display data, Northern analyses, and in situ hybridization micrographs all showed significant up-regulation of ADAMTS-1 gene expression by 8 h after hCG administration. The in situ data indicated that the ADAMTS-1 mRNA was in the granulosa layer of mature follicles. Expression reached a peak at 12 h and remained elevated at 24 h after hCG. ADAMTS-1 gene expression was impaired by the antiprogesterone agent epostane, but this inhibition could be overcome by exogenous progesterone. ADAMTS-1 expression was not affected when ovulation was blocked by treatment of the animals with the anti-eicosanoid agent indomethacin. In conclusion, the temporal pattern of expression of this gene, and its apparent regulation by progesterone, suggests that ADAMTS-1 has a significant role in the inflammatory events of the ovulatory process.

Differentiation-dependent prolactin responsiveness and stat (signal transducers and activators of transcription) signaling in rat ovarian cells

PRL activates an important cytokine signaling cascade that is obligatory for maintaining luteal cell function in the rat ovary. To determine when specific components of this cascade are expressed and can be activated by PRL, we analyzed the expression of receptor subtypes (short, PRL-R(s), and long, PRL-R(L)), the presence and kinetics of Stat (signal transducer and activator of transcription) activation using the PRL-response element (PRL-RE) of the alpha2M (alpha2-macroglobulin) gene, and the content and hormonal regulation of three specific modulators of cytokine signaling; the tyrosine phosphatases (SHP-1 and SHP-2), and the protein inhibitor of activated Stat3 (PIAS-3). These components were analyzed in differentiating granulosa/ luteal cells of hypophysectomized (H) rats and in corpora lutea of pregnant rats. Levels of PRL-R mRNAs increased as granulosa cells differentiated and reached maximal levels in luteal cells of pregnant rats where levels of PRL-R(s) approached those of PRL-R(L). The relative concentrations shifted from a 27-fold excess of PRL-R(L) in preovulatory granulosa cells to a 3.7-fold difference in luteal cells during midgestation. Despite the increased PRL-R(L) expression in differentiated granulosa cells, PRL did not stimulate detectable activation of Stats. Rather PRL activation of Stat5, principally Stat5b, occurred in association with luteinization. In contrast, granulosa cells of untreated immature and H rats contained a high level of DNA binding activity, which was shown to be comprised entirely of activated, phosphorylated Stat3. Treatment with estrogen and FSH reduced the amount of phosphorylated Stat3 and abolished its ability to bind DNA, an effect temporally related to increased PIAS-3. Expression of SHP-1 (but not SHP-2) was also hormonally regulated; SHP-1 mRNA and protein were high in granulosa cells of H rats, decreased by estrogen and FSH, and subsequently increased dramatically with luteinization. Of particular note, SHP-1 was localized in cytoplasm of granulosa cells in atretic follicles but was distinctly nuclear in luteal cells, indicative of different functional roles. Collectively, these results indicate that Stat3 and Stat5 are activated by distinct cytokine-signaling pathways modulated through differentiation-dependent transcriptional regulation of signaling pathway components and mediate distinct functional processes in the rat ovary: early follicle growth and atresia vs. luteinization.

Molecular mechanisms of ovulation and luteinization

Ovulation is a complex process initiated by the mid-cycle surge of luteinizing hormone (LH). Once initiated, a cascade of events occurs that culminates in the release of a fertilizable oocyte. The complex series of events involves specific ovarian cell types, diverse signaling pathways and temporally controlled expression of specific genes. This review will focus on several genes shown to control the ovulation process.

Prolactin-induced activation and binding of stat proteins to the IL-6RE of the alpha 2-macroglobulin (alpha 2M) promoter: relation to the expression of alpha 2M in the rat ovary

Cellular signaling events by which prolactin (PRL) might regulate gene expression were analyzed in rat ovarian tissues. Whole cell extracts (WCE) were prepared from ovaries of pregnant rats (Days 4, 7, 9-11, 15, 17, and 21) and of hormonally primed (estradiol and FSH) hypophysectomized (H) immature rats before, or 15 min to 24 h after, acute administration of PRL (10 micrograms, i.v.). The DNA binding activity in the WCE was analyzed by electrophoretic mobility shift assays using the alpha 2-macroglobulin (alpha 2M) promoter interleukin (IL)-6 response element (IL-6RE) known to confer PRL and IL-6 inducibility to transgenes in target cells, including cultures of luteinized granulosa cells. Injections of PRL stimulated the appearance of a specific binding activity in ovarian extracts of H rats and in corpora lutea and interstitial extracts of pregnant rats from Days 4-9 of pregnancy. The presence of this protein/DNA complex was transient. The greater amount of binding was observed in luteinized tissue and interstitial tissue compared to follicles; and the binding activity contained specific tyrosine phosphorylated Stat (signal transduction and activators of transcription) factors identified by specific antibodies as acute phase response factor (APRF or Stat 3) and mammary gland factor (MGF, or Stat 5 [a and b]). In contrast to the transient activation and appearance of these factors in response to acute PRL treatment as administered to H rats or to pulsatile PRL release as occurs in early pregnancy, elevated levels of the same activated Stat factors were observed in WCE of CL and interstitial tissue prepared at mid-gestation (Days 10-17) when endogenous release of rat placental lactogen (rPL) is chronically elevated in serum. During this period, administration of additional exogenous PRL did not stimulate further activation (binding) of the Stat factors. During luteal regression (Day 21 of gestation) no binding was observed in the absence of PRL, and the response to PRL was markedly diminished despite the constitutive presence of Stat proteins and the Janus kinase that phosphorylates and activates these factors. Elevated binding of these factors to the IL-6RE of the alpha 2M promoter was associated with the expression of alpha 2M mRNA in luteinized granulosa cells and corpora lutea, indicating that activation of Stat factors is one mechanism by which PRL/rPL transactivates the alpha 2M gene in the tissue.

Expression of triosephosphate isomerase transcripts in rat testis: evidence for retinol regulation and a novel germ cell transcript

Vitamin A is essential for mammalian spermatogenesis. To isolate retinol-induced cDNAs from rat testis, vitamin A-deficient (VAD) rats were treated with retinol for 4 h and mRNA isolated from their testes was used to construct a subtractive cDNA library. One cDNA isolated from this library contained a sequence for triosephosphate isomerase (TPI). Northern blot analysis showed that the TPI cDNA hybridized with two transcripts in testis. A 1.4-kb transcript, which is the sole transcript found in most tissues, was expressed in the somatic cells of testis, whereas a novel 1.5-kb transcript was detected only in haploid spermatids. However, only the level of the shorter transcript increased with retinol treatment of the testis or of cultured Sertoli cells. Furthermore, screening of an adult rat testis cDNA library with the TPI cDNA yielded a cDNA putatively corresponding to the 1.5-kb transcript. Sequence analyses of the two TPI cDNAs revealed a 100-bp deletion in one cDNA that may be due to use of an alternative polyadenylation signal. These results suggest independent processing mechanisms for TPI expression in the somatic cells and the haploid germ cells of testis.

The N-terminal peptide of the inhibin alpha subunit What are its endocrine and paracrine roles?

alphaN inhibin (molecular mass 23 24 kD) is present in the pro-alphaN-alphaC subunit of inhibin and can be released by cleavage at the flanking arginine residues during posttranslational processing. Although the alphaN protein isolated from bovine follicular fluid has no inhibinlike (FSH suppressing) activity, alphaN is present in high molecular weight forms of biologically active inhibin found in follicular fluid and plasma. alphaN may modify the biological activity of inhibin by influencing its half-life or access to its receptor. alphaN may also play a role in regulating fertility through a local action on ovulation by the ovary that is independent of the actions of inhibin. The evidence suggests a unique physiological significance for the precursor peptides of the inhibin-alpha subunit in both the endocrine and paracrine control of fertility.

Immunization against the N-terminal peptide of the inhibin alpha 43-subunit (alpha N) disrupts tissue remodeling and the increase in matrix metalloproteinase-2 during ovulation

Immunization of ewes against the N-terminal peptide of inhibin alpha 43 (alpha N) reduces fertility; this is thought to be due to impaired oocyte release at ovulation. This study further investigates the effect of alpha N immunoneutralization on the ovulatory process. Light microscopy was used to examine the effects of alpha N immunization of the tissue-remodeling process during ovulation and formation of the corpus luteum (CL) structure. Changes in follicular levels of matrix metalloproteinase-2 (MMP-2) with approaching ovulation were also investigated in normal and alpha N-immunized ewes. Differences in structure of 2-day-old CL were observed between control and alpha N-immunized ewes. Control CL had confluent luteal tissue throughout the internal structure and invaginations of theca and vasculature were common and penetrated deep into the luteal tissue. Immunized ewe CL had large fluid-filled antra, giving them a cystic appearance; luteal tissue remained a thin 10- to 15-cell layer lining the wall surrounding the antrum. Infolding of the surrounding tissue was incomplete, and thecal/vascular invaginations were rare and failed to penetrate into the luteal tissue. Morphologically normal rupture stigma were seen at the apex of both control and alpha N-immunized CL. Gelatin-digesting activity in follicular fluid collected 0, 12, and 24 h after hCG administration in control ewes increased significantly as the time of ovulation approached (827 +/- 182, 842 +/- 159, and 1230 +/- 89 mU/ml, respectively, in Exp 1; 743 +/- 32, 1182 +/- 98, and 1306 +/- 91 mU/ml at the same times in Exp 2). alpha N immunization reduced follicular gelatinase activity at each time in Exp 1 (533 +/- 132, 740 +/- 67, and 809 +/- 147 mU/ml) and Exp 2 (587 +/- 21, 768 +/- 27, and 891 +/- 53 mU/ml); the reduction was significant at 24 h in Exp 1 and at all times in Exp 2. Gelatin zymography of follicular fluid revealed bands of gelatinase of 72/67 kilodaltons, consistent with latent and active MMP-2. The area digested by both latent and active MMP-2 increased with approaching time of ovulation and was reduced by alpha N immunization. These data suggest that MMP-2 has a role in the tissue-remodeling processes of ovulation and CL formation in the ewe and that immunization against alpha N, which impairs fertility, effects the preovulatory cascade of intrafollicular proteolytic activity, reducing MMP-2 levels and disrupting normal CL formation.

Effect of active immunization against the amino-terminal peptide (alpha N) of the alpha 43 kDa subunit of inhibin (alpha 43) on fertility of ewes

Immunization against the amino-terminal peptide (alpha N) of the alpha 43 subunit of inhibin was shown previously to reduce fertility in ewes. The aim of this study was to examine the effects of active immunization of ewes against alpha N on egg recovery and fertilization rates. Ewes were immunized against alpha N immunogen, and were given 800 I.U. of pregnant mare's serum gonadotrophin at the end of treatment with intravaginal progesterone to synchronize the oestrous cycles. Control ewes received adjuvant only. The ewes were run with fertile rams, and 4 days after withdrawal of the progesterone device the oviducts were flushed to recover eggs and luteal structures on the ovaries were recorded. Eggs were recovered from 17/19 (90%) control ewes compared with 4/16 treated ewes (25%) (P < 0.01), and the egg recovery rates were 76% (45/59) and 17% (7/42) respectively (P < 0.001). The mean number of corpora lutea (CL) per ewe were similar (3.1 +/- 1.4 v. 2.6 +/- 1.0) but several CL in the treated ewes did not appear to have ruptured, and 2 treated ewes had cystic follicles and no CL. There were no apparent differences in either the fertilization rates or the stages of development of fertilized eggs between treated and control ewes. Antibody binding levels in follicular fluid were approximately half those found in peripheral plasma. It is concluded that immunization of ewes against alpha N leads to lowered fertility by suppressing ovulation, implicating alpha N in the normal ovulatory process.

Pituitary and ovarian function in ewes immunized against the amino-terminal peptide (alpha N) of the inhibin alpha 43-subunit

Immunization of ewes against the amino-terminal peptide (alpha N) of the pro-alpha-subunit of inhibin has been shown to reduce fertility, thought to be due to disruption of ovulation. The aims of this study were to examine the effects of active immunization of ewes against alpha N on circulating concentrations of FSH, LH and on ovarian inhibin and progesterone, and to relate these observations to number of corpora lutea and oocyte recovery rates. Ewes were immunized against one or both of two recombinant full length bovine-alpha N immunogens (FP1 and FP2). Three experiments were performed in which jugular venous plasma was sampled from control and immunized ewes: (1) hourly across the oestrous surge of gonadotrophins (Expt 1); (2) daily for one entire oestrous cycle, and in the subsequent cycle, oviducts were flushed to recover ovulated eggs (Expt 2); and (3) samples were taken at 10 min intervals during the follicular and luteal phases (Expt 3). Binding of 125I-labelled alpha N1-26 to serum was greater (P < 0.05) in immunized groups than in controls for all experiments. The number of eggs per corpus luteum recovered from the oviducts was lower (P < 0.05) in the alpha N-immunized groups (39%) than in controls (88%). There were more (P < 0.05) corpora lutea per ewe in FP2 immunized groups 4 (1.8 +/- 0.45) and 5 (1.75 +/- 0.5) than in the control group (1.13 +/- 0.13), but no increase in group 3 (FP1; 1.4 +/- 0.24).(ABSTRACT TRUNCATED AT 250 WORDS)

Binding sites for interferons on ovine and human endometrial membranes

In the ewe, the major product of the preimplantation blastocyst is ovine trophoblast protein-1 (oTP-1), which is now classified as an omega-interferon (IFN). Receptors for IFN are present on sheep endometrium and vary cyclically, presumably modified by the actions of ovarian steroids. This study examined whether or not IFN receptors were present on human endometrium at any stage during the menstrual cycle. In addition, the steroid dependence of ovine endometrial IFN receptors was determined. Specific binding of 125I-labelled IFN (125I-IFN) to ovine endometrial membranes was substantially higher than binding to membranes derived from bovine spleen, human placenta or pooled human endometrium (relative specific binding 100:33:36:20). Human endometrial membrane preparations from proliferative-phase tissue showed very little specific binding (mean 0.8 +/- 0.3%, n = 4) in contrast to luteal-phase endometrium (2.1 +/- 0.3%, n = 8). Treatment of ovariectomized ewes with oestradiol-17 beta (E) resulted in significantly increased binding (117 +/- 7%) of 125I-IFN to endometrial tissues compared with tissue from ovariectomized (OvX, 75 +/- 7%), progesterone (P)-treated (69 +/- 7%), or (E + P)-treated (81 +/- 8%) groups (P < 0.05); all were compared with binding to pooled ovine luteal-phase tissue, 100%. There were no differences between the other three groups. Scatchard analysis showed binding affinity of the same order for the sheep and human receptors (Kd = 10(-10) mol L-1) but binding capacity was considerably lower for human (6.0 fmol mg-1) than for sheep (47-123 fmol mg-1) endometrium.(ABSTRACT TRUNCATED AT 250 WORDS)

Peripheral concentrations of immunoreactive inhibin during pregnancy and parturition in the ewe

The aim of this study was to measure the peripheral concentrations of immunoreactive inhibin (ir-inhibin) and progesterone (P) during pregnancy and parturition in the ewe and to relate the concentrations of ir-inhibin to P and to the number and sex of the fetuses. P increased across pregnancy with higher levels in ewes with 2 fetuses (n = 5) than in those with 1 fetus (n = 6), and concentrations falling before birth. ir-Inhibin concentrations were relatively stable during the first 40 days of pregnancy for example (Day 20, 34.7 +/- 2.9 pmol L-1; mean +/- s.e.m., n = 11). After Day 40, inhibin fell in all ewes to reach less than or equal to 2.5 pmol L-1 after Day 80 (mean on Day 103, 6.3 +/- 1.2 pmol L-1), and remained low until 2 days before parturition when concentrations rose sharply, peaking at or around the day of birth in all ewes (21.5 +/- 2.1 pmol L-1). Thereafter, ir-inhibin fell and remained low or undetectable for up to 10 days in the six ewes still being sampled. ir-Inhibin concentrations in ewes carrying one (n = 6), two (n = 5) or three fetuses (n = 1) did not differ at any stage of pregnancy examined. The sex of the fetus did not appear to influence the peripheral concentrations of ir-inhibin in the ewe.

Sindbis virus mutations which coordinately affect glycoprotein processing, penetration, and virulence in mice

Rapid penetration of baby hamster kidney cells was used as a selective pressure for the isolation of pathogenesis mutants of the S.A.AR86 strain of Sindbis virus. Unlike most Sindbis virus strains, S.A.AR86 is virulent in adult as well as neonatal mice. Two classes of mutants were defined. One class was attenuated in adult mice inoculated intracerebrally as well as in neonatal mice inoculated either intracerebrally or subcutaneously. Sequence analysis of the glycoprotein genes of the parent virus and three such mutant strains revealed a single point mutation which resulted in an amino acid change at position 1 in the E2 glycoprotein. The change from a serine in S.A.AR86 to an asparagine in the mutants created a new site for N-linked glycosylation which appeared to be utilized. This mutation did not retard release of infectious particles; however, mutant virions contained the E2 precursor protein (PE2) rather than the E2 glycoprotein itself. The mutants also lost the ability to bind two E2-specific monoclonal antibodies, R6 and R13. A second class of mutants was attenuated in neonatal mice upon subcutaneous inoculation but remained virulent in adults and in neonates when inoculated intracerebrally. Sequence analysis of three such strains revealed the substitution of an arginine residue for a serine at position 114 in the E2 glycoprotein. Reactivity with monoclonal antibodies R6 and R13 was reduced, yet members of this mutant class were more susceptible than S.A.AR86 to neutralization by these antibodies.

Two-Dimensional Polyacrylamide Gel Analysis of Plodia interpunctella Granulosis Virus

The structural polypeptides of purified Plodia interpunctella granulosis virus were analyzed by three different two-dimensional gel systems. Isoelectric focusing followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis allowed resolution of 53 acidic polypeptides in the enveloped nucleocapsid of the virus ranging in molecular weight from 97,300 to 8,000. Nine of these polypeptides were shown to be glycoproteins by the technique of radiolabeled lectin blotting. Separation of the granulin in this system allowed resolution of five species, all of which have identical tryptic peptide maps. This matrix protein was demonstrated to be a phosphoglycoprotein by radiolabeled lectin blotting and acid phosphatase dephosphorylation. Nonequilibrium pH gel electrophoresis followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis allowed resolution of the major basic protein of the virus, VP12, from a more acidic protein of the same molecular weight. Tryptic peptide analysis demonstrated that these two proteins were indeed different and acid urea gels followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis allowed localization of the acidic protein to the envelope and the basic protein to the nucleocapsid of the virus. Finally, probing of the separated envelope nucleocapsid proteins in both the isoelectric focusing and nonequilibrium pH gel electrophoresis two-dimensional systems after transfer to nitrocellulose with iodinated, purified viral proteins allowed further insight into reactions which may be important in the maintenance of the virion structure.

Glycosylation of purified enveloped nucleocapsids of the granulosis virus infecting Plodia interpunctella as determined by lectin binding

Using various iodinated plant lectins and a sensitive in vitro lectin binding procedure in which the radiolabeled lectins are applied directly to viral proteins on nitrocellulose sheets transferred from sodium dodecyl sulfate-polyacrylamide gels (Bartles and Hubbard, 1984; Glass et al., 1981), the proteins of the granulosis virus infecting Plodia interpunctella were probed for carbohydrate moieties. Six proteins (Mr 39 700, 31 000, 29 900, 26 300, 17 800 and 12 600) could be detected using a probe for alpha-D-N-acetylgalactosamine. Three proteins were also detectable with the probe specific for alpha-L-fucose (Mr 44 900, 31 000 and 17 800). One protein (Mr 17 800) was detected with the probe for sialic acid.

Suppressors of mutations in the bacteriophage T4 gene coding for both RNA ligase and tail fiber attachment activities

The protein product of T4 gene 63 catalyzes both the attachment of tail fibers to fiberless phage particles and the ligation of single-stranded RNA (Snopek at al., Proc. Natl. Acad. Sci. U.S.A. 74:3355-3359, 1977). To investigate whether the gene 63 product has a role in nucleotide metabolism, we isolated false revertants of amM69 in gene 63. We screened for revertants that could grow at 30 degrees C but not at 43 degrees C on Escherichia coli OK305 when nucleotides were limiting. These false revertants contained the original mutation in gene 63 and new suppressor mutations. Some of these suppressor mutations caused temperature sensitivity by themselves, allowing single mutants carrying the suppressor to be recognized and isolated. The results of mapping and complementation studies indicated that most of these ts suppressors were in the t gene (lysis), one was in gene 5 (baseplate), and one was in gene 18 (sheath). The mutation in gene 18, tsDH638, suppressed three different amber mutations in gene 63 but did not suppress amber mutations in several other genes. None of the suppressors that were characterized were in genes with known functions in nucleotide metabolism. However, an intriguing property of these false revertants was that they were very sensitive to hydroxyurea, an inhibitor of nucleotide metabolism.

Experimental participation as a source of stimulation in sensory and perceptual deprivation studies of stimulus-seeking behavior by introverts and extraverts

The hypothesis that the experiment itself provided a change in stimulation was tested under conditions of perceptual deprivation with and without delay of self-stimulation in a free operant situation. Also tested was the hypothesis that extraverts would differ from introverts in seeking more frequent changes in self-administered sound stimulation, rather than in seeking stimulation of greater duration. Parametric tests indicated no significant difference between delay and non-delay groups or between introverts and extraverts with respect to duration and frequency of sound stimulation. Non-parametric test, however, showed extraverts tended to seek significantly more changes of self-stimulation than introverts.