Publications by authors named "Brandy L Dozier"

15 Publications

  • Page 1 of 1

Urothelial carcinoma in the urinary bladder of a Japanese macaque (Macaca fuscata).

J Med Primatol 2021 Apr 5;50(2):141-143. Epub 2021 Feb 5.

Pathology Services Unit, Division of Comparative Medicine, Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, Oregon.

Tumors of urinary origin are infrequently reported in non-human primates. Urothelial carcinoma involving the urinary bladder was diagnosed in an adult female Japanese macaque that extended transmurally to the uterus and cervix. To our knowledge, this is the first report of a primary cystic urothelial carcinoma in a Japanese macaque.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/jmp.12508DOI Listing
April 2021

A neonatal nonhuman primate model of gestational Zika virus infection with evidence of microencephaly, seizures and cardiomyopathy.

PLoS One 2020 14;15(1):e0227676. Epub 2020 Jan 14.

Vaccine & Gene Therapy Institute, Oregon Health & Science University, Beaverton, Oregon, United States of America.

Zika virus infection during pregnancy is associated with miscarriage and with a broad spectrum of fetal and neonatal developmental abnormalities collectively known as congenital Zika syndrome (CZS). Symptomology of CZS includes malformations of the brain and skull, neurodevelopmental delay, seizures, joint contractures, hearing loss and visual impairment. Previous studies of Zika virus in pregnant rhesus macaques (Macaca mulatta) have described injury to the developing fetus and pregnancy loss, but neonatal outcomes following fetal Zika virus exposure have yet to be characterized in nonhuman primates. Herein we describe the presentation of rhesus macaque neonates with a spectrum of clinical outcomes, including one infant with CZS-like symptoms including cardiomyopathy, motor delay and seizure activity following maternal infection with Zika virus during the first trimester of pregnancy. Further characterization of this neonatal nonhuman primate model of gestational Zika virus infection will provide opportunities to evaluate the efficacy of pre- and postnatal therapeutics for gestational Zika virus infection and CZS.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0227676PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6959612PMC
April 2020

Bardet-Biedl Syndrome in rhesus macaques: A nonhuman primate model of retinitis pigmentosa.

Exp Eye Res 2019 12 4;189:107825. Epub 2019 Oct 4.

Division of Neuroscience, Oregon National Primate Research Center, Oregon Health & Sciences University, Beaverton, OR, 97006, USA; Casey Eye Institute, Oregon Health & Sciences University, Portland, OR, 97239, USA. Electronic address:

The development of therapies for retinal disorders is hampered by a lack of appropriate animal models. Higher nonhuman primates are the only animals with retinal structure similar to humans, including the presence of a macula and fovea. However, few nonhuman primate models of genetic retinal disease are known. We identified a lineage of rhesus macaques with a frameshift mutation in exon 3 of the BBS7 gene c.160delG (p.Ala54fs) that is predicted to produce a non-functional protein. In humans, mutations in this and other BBS genes cause Bardet-Biedl syndrome, a ciliopathy and a syndromic form of retinitis pigmentosa generally occurring in conjunction with kidney dysfunction, polydactyly, obesity, and/or hypogonadism. Three full- or half-sibling monkeys homozygous for the BBS7 c.160delG variant, at ages 3.5, 4 and 6 years old, displayed a combination of severe photoreceptor degeneration and progressive kidney disease. In vivo retinal imaging revealed features of severe macular degeneration, including absence of photoreceptor layers, degeneration of the retinal pigment epithelium, and retinal vasculature atrophy. Electroretinography in the 3.5-year-old case demonstrated loss of scotopic and photopic a-waves and markedly reduced and delayed b-waves. Histological assessments in the 4- and 6-year-old cases confirmed profound loss of photoreceptors and inner retinal neurons across the posterior retina, with dramatic thinning and disorganization of all cell layers, abundant microglia, absent or displaced RPE cells, and significant gliosis in the subretinal space. Retinal structure, including presence of photoreceptors, was preserved only in the far periphery. Ultrasound imaging of the kidneys revealed deranged architecture, and renal histopathology identified distorted contours with depressed, fibrotic foci and firmly adhered renal capsules; renal failure occurred in the 6-year-old case. Magnetic resonance imaging obtained in one case revealed abnormally low total brain volume and unilateral ventricular enlargement. The one male had abnormally small testes at 4 years of age, but polydactyly and obesity were not observed. Thus, monkeys homozygous for the BBS7 c.160delG variant closely mirrored several key features of the human BBS syndrome. This finding represents the first identification of a naturally-occurring nonhuman primate model of BBS, and more broadly the first such model of retinitis pigmentosa and a ciliopathy with an associated genetic mutation. This important new preclinical model will provide the basis for better understanding of disease progression and for the testing of new therapeutic options, including gene and cell-based therapies, not only for BBS but also for multiple forms of photoreceptor degeneration.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.exer.2019.107825DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7064310PMC
December 2019

Candida albicans-associated sepsis in a pre-term neonatal rhesus macaque (Macaca mulatta).

J Med Primatol 2019 06 8;48(3):186-188. Epub 2019 Feb 8.

Oregon National Primate Research Center, Division of Comparative Medicine, Oregon Health & Science University, Portland, Oregon.

Invasive Candida infections (ICI) have been associated with neurodevelopmental impairment or death in human pre-term neonates. Candidiasis in nonhuman primates is seen mostly in immunosuppressed animals, and ICI is not commonly reported. Here, we report a case of Candida albicans-associated ICI in a pre-term neonatal rhesus macaque.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/jmp.12401DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6520160PMC
June 2019

Chronic ethanol drinking increases during the luteal menstrual cycle phase in rhesus monkeys: implication of progesterone and related neurosteroids.

Psychopharmacology (Berl) 2019 Jun 15;236(6):1817-1828. Epub 2019 Jan 15.

Division of Neuroscience, Oregon National Primate Research Center, 505 NW 185th Avenue, Beaverton, OR, 97006, USA.

Rationale: Sporadic reports of alcohol consumption being linked to menstrual cycle phase highlight the need to consider hormonally characterized menstrual cycle phase in understanding the sex-specific effects of risk for alcohol drinking in women.

Objectives: We investigated the association between menstrual cycle phase, characterized by circulating progesterone and menses, with accurate daily alcohol intakes in rhesus monkeys, and the contribution of progesterone derived neuroactive steroids to cycle-related alcohol drinking.

Methods: Menses (daily) and progesterone (2-3×/week) were obtained in female monkeys (n = 8, 5 ethanol, 3 control) for 12-18 months. Ethanol monkeys were then induced to drink ethanol (4% w/v; 3 months) and given 22 h/day access to ethanol and water for approximately 1 year. In selected cycles, a panel of neuroactive steroids were assayed during follicular and luteal phases from pre-ethanol and ethanol exposure.

Results: There were minimal to no effects of ethanol on menstrual cycle length, progesterone levels, and follicular or luteal phase length. The monkeys drank more ethanol during the luteal phase, compared to the follicular phase, and ethanol intake was highest in the late luteal phase when progesterone declines rapidly. Two neuroactive steroids were higher during the luteal phase versus the follicular phase, and several neuroactive steroids were higher in the pre- vs. post-ethanol drinking menstrual cycles.

Conclusions: This is the first study to show that normal menstrual cycle fluctuations in progesterone, particularly during the late luteal phase, can modulate ethanol intake. Two of 11 neuroactive steroids were selectively associated with the effect of cycle progesterone on ethanol drinking, suggesting possible links to CNS mechanisms of ethanol intake control.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00213-019-5168-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6606379PMC
June 2019

Beyond the uterine environment: a nonhuman primate model to investigate maternal-fetal and neonatal outcomes following chronic intrauterine infection.

Pediatr Res 2017 Aug 24;82(2):244-252. Epub 2017 May 24.

Division of Reproductive and Developmental Sciences, Oregon National Primate Research Center, Beaverton, Oregon.

BackgroundIntrauterine infection is a significant cause of early preterm birth. We have developed a fetal-neonatal model in the rhesus macaque to determine the impact of chronic intrauterine infection with Ureaplasma parvum on early neonatal reflexes and brain development.MethodsTime-mated, pregnant rhesus macaques were randomized to be inoculated with U. parvum (serovar 1; 10c.f.u.) or control media at ~120 days' gestational age (dGA). Neonates were delivered by elective hysterotomy at 135-147 dGA (term=167d), stabilized, and cared for in our nonhuman primate neonatal intensive care unit. Neonatal reflex behaviors were assessed from birth, and fetal and postnatal brain magnetic resonance imaging (MRI) was performed.ResultsA total of 13 preterm and 5 term macaque infants were included in the study. Ten preterm infants survived to 6 months of age. U. parvum-infected preterm neonates required more intensive respiratory support than did control infants. MRI studies suggested a potential perturbation of brain growth and white matter maturation with exposure to intra-amniotic infection.ConclusionWe have demonstrated the feasibility of longitudinal fetal-neonatal studies in the preterm rhesus macaque after chronic intrauterine infection. Future studies will examine long-term neurobehavioral outcomes, cognitive development, neuropathology, and in vivo brain imaging to determine the safety of antenatal antibiotic treatment for intrauterine infection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/pr.2017.57DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5552412PMC
August 2017

Ventricular Parasystole in a Neonatal Rhesus Macaque ().

Comp Med 2016 12;66(6):489-493

Division of Comparative Medicine, Oregon National Primate Research Center, Beaverton, Oregon.

A 6-d-old Indian-origin female rhesus macaque (Macaca mulatta) presented with bradycardia shortly after sedation with ketamine. No other cardiac abnormalities were apparent. Approximately 2 wk after the initial presentation, the macaque was again bradycardic and exhibited a regularly irregular arrhythmia on a prestudy examination. ECG, echocardiography, blood pressure measurement, SpO2 assessment, and a CBC analysis were performed. The echocardiogram and bloodwork were normal, but the infant was hypotensive at the time of echocardiogram. The ECG revealed ventricular parasystole. Ventricular parasystole is considered a benign arrhythmia caused by an ectopic pacemaker that is insulated from impulses from the sinus node. Given this abnormality, the macaque was transferred to a short-term study protocol, according to veterinary recommendation. On the final veterinary exam, a grade 3 systolic murmur and a decrease in arrhythmia frequency were noted. Gross cardiac lesions were not identified at necropsy the following day. Cardiac tissue sections were essentially normal on microscopic examination. This infant did not display signs of cardiovascular insufficiency, and a review of the medical record indicated normal growth, feed intake and activity levels. This case demonstrates the importance of appropriate screening of potential neonatal and juvenile research candidates for occult cardiovascular abnormalities. Whether the arrhythmia diagnosed in this case was truly innocuous is unclear, given the documented hypotension and the development of a systolic heart murmur.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5157965PMC
December 2016

EP3 receptor isoforms are differentially expressed in subpopulations of primate granulosa cells and couple to unique G-proteins.

Reproduction 2013 Dec 21;146(6):625-35. Epub 2013 Oct 21.

Physiological Sciences.

Prostaglandin E2 (PGE2) produced within the ovarian follicle is necessary for ovulation. PGE2 is recognized by four distinct G-protein-coupled receptors. Among them, PTGER3 (also known as EP3) is unique in that mRNA splicing generates multiple isoforms. Each isoform has a distinct amino acid composition in the C-terminal region, which is involved in G-protein coupling. To determine whether monkey EP3 isoforms couple to different G-proteins, each EP3 isoform was expressed in Chinese hamster ovary cells, and intracellular signals were examined after stimulation with the EP3 agonist sulprostone. Stimulation of EP3 isoform 5 (EP3-5) reduced cAMP in a pertussis toxin (PTX)-sensitive manner, indicating involvement of Gαi. Stimulation of EP3-9 increased cAMP, which was reduced by the general G-protein inhibitor GDP-β-S, and also increased intracellular calcium, which was reduced by PTX and GDP-β-S. So, EP3-9 likely couples to both Gαs and a PTX-sensitive G-protein to regulate intracellular signals. Stimulation of EP3-14 increased cAMP, which was further increased by PTX, so EP3-14 likely regulates cAMP via multiple G-proteins. Granulosa cell expression of all EP3 isoforms increased in response to an ovulatory dose of human chorionic gonadotropin. Two EP3 isoforms were differentially expressed in functional subpopulations of granulosa cells. EP3-5 was low in granulosa cells at the follicle apex while EP3-9 was high in cumulus granulosa cells. Differential expression of EP3 isoforms may yield different intracellular responses to PGE2 in granulosa cell subpopulations, contributing to the different roles played by granulosa cell subpopulations in the process of ovulation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1530/REP-13-0274DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3832896PMC
December 2013

Prostaglandin E2 receptors are differentially expressed in subpopulations of granulosa cells from primate periovulatory follicles.

Biol Reprod 2011 Nov 13;85(5):916-23. Epub 2011 Jul 13.

Department of Physiological Sciences, Eastern Virginia Medical School, Norfolk, Virginia, USA.

Prostaglandin E2 (PGE2) mediates many effects of the midcycle luteinizing hormone (LH) surge within the periovulatory follicle. Differential expression of the four PGE2 (EP) receptors may contribute to the specialized functions of each granulosa cell subpopulation. To determine if EP receptors are differentially expressed in granulosa cells, monkeys received gonadotropins to stimulate ovarian follicular development. Periovulatory events were initiated with human chorionic gonadotropin (hCG); granulosa cells and whole ovaries were collected before (0 h) and after (24-36 h) hCG to span the 40-h primate periovulatory interval. EP receptor mRNA and protein levels were quantified in granulosa cell subpopulations. Cumulus cells expressed higher levels of EP2 and EP3 mRNA compared with mural cells 36 h after hCG. Cumulus cell EP2 and EP3 protein levels also increased between 0 and 36 h after hCG. Overall, mural granulosa cells expressed low levels of EP1 protein at 0 h and higher levels 24-36 h after hCG. However, EP1 protein levels were higher in granulosa cells away from the follicle apex compared with apex cells 36 h after hCG. Higher levels of PAI-1 protein were measured in nonapex cells, consistent with a previous study showing EP1-stimulated PAI-1 protein expression in monkey granulosa cells. EP4 protein levels were low in all subpopulations. In summary, cumulus cells likely respond to PGE2 via EP2 and EP3, whereas PGE2 controls rupture of a specific region of the follicle via EP1. Therefore, differential expression of EP receptors may permit each granulosa cell subpopulation to generate a unique response to PGE2 during the process of ovulation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1095/biolreprod.111.091306DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3197913PMC
November 2011

Two pathways for prostaglandin F2 alpha synthesis by the primate periovulatory follicle.

Reproduction 2008 Jul 4;136(1):53-63. Epub 2008 Apr 4.

Department of Physiological Sciences, Eastern Virginia Medical School, 700 Olney Road, Lewis Hall, Norfolk, Virginia 23507, USA.

Prostaglandin E2 (PGE2) has been identified as a PG necessary for ovulation, but the ovulatory gonadotropin surge also increases PGF2 alpha levels in primate periovulatory follicles. To better understand the role of PGF2 alpha in ovulation, pathways utilized for PGF2 alpha synthesis by the primate follicle were examined. Monkeys were treated with gonadotropins to stimulate multiple follicular development; follicular aspirates and whole ovaries were removed before and at specific times after administration of an ovulatory dose of hCG to span the 40 h periovulatory interval. Human granulosa cells were also obtained (typically 34-36 h after hCG) from in vitro fertilization patients. PGF2 alpha can be synthesized from PGH2 via the aldo-keto reductase (AKR) 1C3. AKR1C3 mRNA and protein levels in monkey granulosa cells were low before hCG and peaked 24-36 h after hCG administration. Human granulosa cells converted PGD2 into 11 beta-PGF2 alpha, confirming that these cells possess AKR1C3 activity. PGF2 alpha can also be synthesized from PGE2 via the enzymes AKR1C1 and AKR1C2. Monkey granulosa cell levels of AKR1C1/AKR1C2 mRNA was low 0-12 h, peaked at 24 h, and returned to low levels by 36 h after hCG administration. Human granulosa cell conversion of [(3)H]PGE2 into [(3)H]PGF2 alpha was reduced by an AKR1C2-selective inhibitor, supporting the concept that granulosa cells preferentially express AKR1C2 over AKR1C1. In summary, the ovulatory gonadotropin surge increases granulosa cell expression of AKR1C1/AKR1C2 and AKR1C3. Both of these enzyme activities are present in periovulatory granulosa cells. These data support the concept that follicular PGF2 alpha can be synthesized via two pathways during the periovulatory interval.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1530/REP-07-0514DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2656351PMC
July 2008

Prostaglandin-endoperoxide synthase (PTGS1 and PTGS2) expression and prostaglandin production by normal monkey ovarian surface epithelium.

Fertil Steril 2006 Oct 7;86(4 Suppl):1088-96. Epub 2006 Sep 7.

The Jones Institute for Reproductive Medicine, Department of Obstetrics and Gynecology, Eastern Virginia Medical School, Norfolk, Virginia, USA.

Objective: To determine whether hCG regulates the expression of prostaglandin (PG) synthesis enzymes and the production of PGs by normal monkey ovarian surface epithelium (OSE).

Design: Experimental animal study.

Setting: Research laboratory.

Animal(s): Adult cynomolgus macaques.

Intervention(s): Monkeys received exogenous gonadotropins to stimulate multiple follicular development. Ovarian surface epithelium cells and whole ovaries were obtained before (0 hours) and 36 hours after an ovulatory dose of hCG.

Main Outcome Measure(s): Ovarian surface epithelium expression of prostaglandin-endoperoxide synthase 1 (PTGS1) and PTGS2 proteins was determined by immunocytochemistry. Prostaglandin synthesis enzyme messenger RNA (mRNA) levels were determined by RT-PCR. Prostaglandin E2 and PGF2alpha production was assessed by enzyme immunoassays.

Result(s): Ovarian surface epithelium maintained in long-term culture expressed mRNA and protein for PTGS1 and PTGS2 (n = 6); inhibition of PTGS1, but not PTGS2, reduced PGE2 synthesis (n = 3). Prostaglandin-endoperoxide synthase 1 was present in OSE of ovarian tissue sections obtained 0 (n = 4) and 36 (n = 3) hours after hCG; PTGS2 was not detected. Ovarian surface epithelium collected 0 (n = 3) and 36 (n = 4) hours after hCG expressed mRNAs for PTGS1, PTGS2, and three PGE synthases; the ratio of PTGS2 to PTGS1 increased in response to hCG exposure.

Conclusion(s): Monkey OSE expresses mRNA for PTGS1, PTGS2, and all PGE synthases and produces PGE2 both before and 36 hours after hCG. Detection of PTGS1, but not PTGS2, protein in OSE in vivo supports the hypothesis that PTGS1 is the enzyme responsible for PGE2 production by primate OSE in vivo.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.fertnstert.2006.03.022DOI Listing
October 2006

Primate granulosa cell response via prostaglandin E2 receptors increases late in the periovulatory interval.

Biol Reprod 2006 Dec 30;75(6):868-76. Epub 2006 Aug 30.

Department of Physiological Sciences, Eastern Virginia Medical School, Norfolk, Virginia 23507-1980, USA.

Successful ovulation requires elevated follicular prostaglandin E2 (PGE2) levels. To determine which PGE2 receptors are available to mediate periovulatory events in follicles, granulosa cells and whole ovaries were collected from monkeys before (0 h) and after administration of an ovulatory dose of hCG to span the 40-h periovulatory interval. All PGE2 receptor mRNAs were present in monkey granulosa cells. As assessed by immunofluorescence, PTGER1 (EP1) protein was low/nondetectable in granulosa cells 0, 12, and 24 h after hCG but was abundant 36 h after hCG administration. PTGER2 (EP2) and PTGER3 (EP3) proteins were detected by immunofluorescence in granulosa cells throughout the periovulatory interval, and Western blotting showed an increase in PTGER2 and PTGER3 levels between 0 h and 36 h after hCG. In contrast, PTGER4 (EP4) protein was not detected in monkey granulosa cells. Granulosa cell response to PGE2 receptor agonists was examined 24 h and 36 h after hCG administration, when elevated PGE2 levels present in periovulatory follicles initiate ovulatory events. PGE2 acts via PTGER1 to increase intracellular calcium. PGE2 increased intracellular calcium in granulosa cells obtained 36 h, but not 24 h, after hCG; this effect of PGE2 was blocked by a PTGER1 antagonist. A PTGER2-specific agonist and a PTGER3-specific agonist each elevated cAMP in granulosa cells obtained 36 h, but not 24 h, after hCG. Therefore, the granulosa cells of primate periovulatory follicles express multiple receptors for PGE2. Granulosa cells respond to agonist stimulation of each of these receptors 36 h, but not 24 h, after hCG, supporting the hypothesis that granulosa cells are most sensitive to PGE2 as follicular PGE2 levels peak, leading to maximal PGE2-mediated periovulatory effects just before ovulation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1095/biolreprod.106.053769DOI Listing
December 2006

An ovulatory gonadotropin stimulus increases cytosolic phospholipase A2 expression and activity in granulosa cells of primate periovulatory follicles.

J Clin Endocrinol Metab 2005 Oct 21;90(10):5858-65. Epub 2005 Jun 21.

Department of Physiological Sciences, Eastern Virginia Medical School, 700 Olney Road, Lewis Hall, Norfolk, Virginia 23507, USA.

Context: Prostaglandins (PGs) produced within ovarian follicles in response to the ovulatory gonadotropin surge are essential for follicle rupture and oocyte release. Arachidonic acid, the common precursor for PG synthesis, is cleaved from membrane phospholipids via the activity of phospholipase A2 (PLA2).

Objective: The purpose of this study was to determine which PLA2 form(s) is involved in PG production by primate periovulatory follicles.

Design And Interventions: Gonadotropins were administered to cynomolgus monkeys to stimulate multiple follicular development; human chorionic gonadotropin (hCG) initiated periovulatory events. Granulosa cells and whole ovaries were obtained before (0 h), and 12, 24, and 36 h after hCG administration.

Patients: Granulosa-lutein cells were also obtained from women undergoing infertility treatment.

Outcome Measures And Results: mRNA for cytosolic (c)PLA2 and secretory (s)PLA2V, but not sPLA2IIA, was expressed by granulosa cells. cPLA2 mRNA levels were low at 0 h, elevated by 12 h, and remained high 24-36 h after hCG administration. sPLA2V mRNA levels were low at 0 h and did not change in response to hCG. cPLA2 and sPLA2V were detected by immunocytochemistry in granulosa cells of periovulatory follicles before and at all times after hCG administration. PLA2 activity was low in lysates of granulosa cells obtained 0-24 h after hCG and was elevated in granulosa cells obtained 36 h after hCG administration. A cPLA2-selective inhibitor decreased both PLA2 activity in monkey granulosa cell lysates and PGE2 accumulation in cultures of human granulosa-lutein cells.

Conclusions: cPLA2 is primarily or exclusively responsible for the gonadotropin-stimulated mobilization of arachidonic acid necessary for PG production by primate periovulatory follicles.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1210/jc.2005-0980DOI Listing
October 2005

Microsomal prostaglandin E synthase-1 (mPGES-1) is the primary form of PGES expressed by the primate periovulatory follicle.

Hum Reprod 2005 Jun 17;20(6):1485-92. Epub 2005 Mar 17.

Department of Physiological Sciences, Eastern Virginia Medical School, 700 Olney Road, Lewis Hall, Norfolk, VA 23507, USA.

Background: Prostaglandin E2 (PGE2) has been identified as the key ovulatory PG in the primate follicle. Follicular PGE2 levels increase just before the expected time of ovulation, suggesting that the midcycle LH surge induces the expression of enzymes involved in PGE2 synthesis.

Methods: To identify the specific form(s) of prostaglandin E synthase (PGES) expressed by the primate periovulatory follicle, we examined granulosa and theca cell expression of the three microsomal (m) and cytosolic (c) forms of PGES (mPGES-1, mPGES-2 and cPGES) identified to date. Monkey granulosa cells and whole monkey ovaries were obtained from animals receiving exogenous gonadotropins to stimulate multiple follicular development; monkeys then received an ovulatory dose of HCG to initiate periovulatory events.

Results: Expression of mPGES-1 mRNA and protein by granulosa cells of periovulatory follicles increased in response to HCG administration, peaking just before the expected time of ovulation. Immunocytochemistry showed that mPGES-1 protein was present in both granulosa and theca cells of monkey periovulatory follicles. Monkey granulosa cells also expressed mPGES-2 and cPGES mRNA, but mRNA levels did not change in response to HCG administration. Isolated monkey theca cells expressed both mPGES-1 and cyclooxygenase-2 mRNA, and produced PGE2 in vitro. Human granulosa-lutein cells obtained from women undergoing treatment for infertility expressed mRNAs for mPGES-1, mPGES-2 and cPGES.

Conclusions: These data indicate that mPGES-1 is a gonadotropin-regulated PG synthesis enzyme expressed by granulosa cells of primate periovulatory follicles and suggest that mPGES-1 may be the primary PGES responsible for the increased follicular PGE2 levels necessary for primate ovulation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/humrep/deh784DOI Listing
June 2005

Prostaglandin dehydrogenase and prostaglandin levels in periovulatory follicles: implications for control of primate ovulation by prostaglandin E2.

J Clin Endocrinol Metab 2005 Feb 2;90(2):1021-7. Epub 2004 Nov 2.

Department of Physiological Sciences, Eastern Virginia Medical School, Norfolk, Virginia 23507, USA.

Prostaglandin (PG) E2 produced by the periovulatory follicle in response to the midcycle LH surge is essential for successful ovulation in primates. Granulosa cells express the PG synthesis enzyme cyclooxygenase-2 in response to the LH surge, but elevated cyclooxygenase-2 mRNA levels precede rising follicular fluid PGE2 levels by 24 h. Therefore, PG metabolism may play a significant role in regulating follicular concentrations of PGE2 during the periovulatory interval. To test this hypothesis, granulosa cells, follicular fluid, and whole ovaries were obtained from adult monkeys receiving exogenous gonadotropins to stimulate development of multiple, large follicles at times spanning the 40-h periovulatory interval. Ovarian expression of the NAD+-dependent 15-hydroxy PG dehydrogenase (PGDH) was assessed by RT-PCR, Western blotting, and immunohistochemistry. PGDH mRNA levels were low in granulosa cells obtained 0 h after hCG, rose 10-fold 12 h after hCG, and were not different from 0 h by 24-36 h after hCG administration. Granulosa cell PGDH protein was present 0-12 h after hCG but was low/nondetectable 36 h after hCG administration. Follicular fluid PGE2 levels were low at 0-12 h, slightly higher at 24 h, and then rose 10-fold to peak at 36 h hCG. Levels of biologically inactive PGE2 metabolites in follicular fluid were also low at 0 h but elevated at 12-24 h after hCG, times at which PGE2 levels remain low. Therefore, PGDH is present in the primate periovulatory follicle in a pattern consistent with modulation of follicular PGE2 levels during the periovulatory interval, supporting the hypothesis that gonadotropin-regulated PGDH plays a role in the control and timing of ovulation in primates.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1210/jc.2004-1229DOI Listing
February 2005