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1.
Nature ; 627(8003): 281-285, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38286342

RESUMO

Tight relationships exist in the local Universe between the central stellar properties of galaxies and the mass of their supermassive black hole (SMBH)1-3. These suggest that galaxies and black holes co-evolve, with the main regulation mechanism being energetic feedback from accretion onto the black hole during its quasar phase4-6. A crucial question is how the relationship between black holes and galaxies evolves with time; a key epoch to examine this relationship is at the peaks of star formation and black hole growth 8-12 billion years ago (redshifts 1-3)7. Here we report a dynamical measurement of the mass of the black hole in a luminous quasar at a redshift of 2, with a look back in time of 11 billion years, by spatially resolving the broad-line region (BLR). We detect a 40-µas (0.31-pc) spatial offset between the red and blue photocentres of the Hα line that traces the velocity gradient of a rotating BLR. The flux and differential phase spectra are well reproduced by a thick, moderately inclined disk of gas clouds within the sphere of influence of a central black hole with a mass of 3.2 × 108 solar masses. Molecular gas data reveal a dynamical mass for the host galaxy of 6 × 1011 solar masses, which indicates an undermassive black hole accreting at a super-Eddington rate. This suggests a host galaxy that grew faster than the SMBH, indicating a delay between galaxy and black hole formation for some systems.

2.
J Vet Cardiol ; 47: 70-82, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37267820

RESUMO

OBJECTIVES: Atrioventricular accessory pathways are abnormal electrical connections between the atria and ventricles that predispose to ventricular pre-excitation (VPE) and tachycardias. ANIMALS: Seventeen cats with VPE and 15 healthy matched-control cats. MATERIAL AND METHODS: Multicenter case-control retrospective study. Clinical records were searched for cats with VPE, defined as preserved atrioventricular synchrony, reduced PQ interval, and increased QRS complex duration with a delta wave. Clinical, electrocardiography, echocardiographic, and outcome data were collated. RESULTS: Most cats with VPE were male (16/17 cats), non-pedigree cats (11/17 cats). Median age and mean body weight were 5.4 years (0.3-11.9 years) and 4.6 ± 0.8 kg, respectively. Clinical signs at presentation included lethargy (10/17 cats), tachypnea (6/17 cats), and/or syncope (3/17 cats). In two cats, VPE was an incidental finding. Congestive heart failure was uncommon (3/17 cats). Nine (9/17) cats had tachyarrhythmias: 7/9 cats had narrow QRS complex tachycardia and 2/9 cats had wide QRS complex tachycardia. Four cats had ventricular arrhythmias. Cats with VPE had larger left (P < 0.001) and right (P < 0.001) atria and thicker interventricular septum (P = 0.019) and left ventricular free wall (P = 0.028) than controls. Three cats had hypertrophic cardiomyopathy. Treatment included different combinations of sotalol (5/17 cats), diltiazem (5/17 cats), atenolol (4/17 cats), furosemide (4/17 cats), and platelet inhibitors (4/17 cats). Five cats died, all from cardiac death (median survival time 1882 days [2-1882 days]). CONCLUSIONS: Cats with VPE had a relatively long survival, albeit showing larger atria and thicker left ventricular walls than healthy cats.


Assuntos
Doenças do Gato , Síndromes de Pré-Excitação , Síndrome de Wolff-Parkinson-White , Masculino , Gatos , Animais , Feminino , Síndrome de Wolff-Parkinson-White/veterinária , Estudos Retrospectivos , Síndromes de Pré-Excitação/diagnóstico , Síndromes de Pré-Excitação/veterinária , Taquicardia/veterinária , Eletrocardiografia/veterinária , Doenças do Gato/diagnóstico por imagem
3.
J Vet Cardiol ; 47: 47-54, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37196397

RESUMO

INTRODUCTION/OBJECTIVES: The aim of this study was to compare a novel small event recorder device, the Carnation Ambulatory Monitor (CAM), with a standard Holter. ANIMALS: Nineteen adult dogs. MATERIAL AND METHODS: Comparative and explorative study. The two devices were simultaneously applied for approximately 24 h. RESULTS: Analysis time (P=0.013) and percentage of artefacts (P<0.001) were greater for the CAM (110 min [40-264]; and 9% [0-34], respectively) compared to a standard Holter (30 min [18-270]; and 0.3% [0-9], respectively). The total number of beats (P=0.017) and maximum (P=0.02) and mean (P=0.037) heart rates were lower for the CAM (113,806 ± 23,619 beats; 227 ± 35 bpm; and 88 ± 22 bpm, respectively) compared to the standard Holter (131,640 ± 40,037 beats; 260 ± 64 bpm; and 92 ± 26 bpm, respectively). The minimal heart rate (P=0.725), number of pauses (P=0.078), duration of the longest pause (P=0.087), number of ventricular ectopic complexes (P=0.55), ventricular couplets (P=0.186), ventricular triplets (P=0.203), ventricular tachycardia (P=0.05), Lown grade (P=0.233), presence or absence of ventricular bigeminy, trigeminy, supraventricular tachycardia, and atrial fibrillation (P=0.98) did not differ. The CAM missed some relevant events, like complex ventricular arrhythmias, and the Lown grade did not match in 5/19 dogs when comparing the devices. CONCLUSIONS: Cardiac Ambulatory Monitor can be used to record ECG traces in dogs over a prolonged period, allowing to detect arrhythmias. Due to some clinically relevant limitations, including a higher percentage of artefacts, a longer reading time (which precludes quantitative counts of >300ventricular premature complexes), and underestimation of complex ventricular arrhythmias, the CAM appears not suitable for quantitative arrhythmia analysis in dogs.


Assuntos
Fibrilação Atrial , Doenças do Cão , Taquicardia Ventricular , Complexos Ventriculares Prematuros , Cães , Animais , Eletrocardiografia Ambulatorial/veterinária , Eletrocardiografia , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/veterinária , Taquicardia Ventricular/diagnóstico , Taquicardia Ventricular/veterinária , Complexos Ventriculares Prematuros/diagnóstico , Complexos Ventriculares Prematuros/veterinária , Doenças do Cão/diagnóstico
4.
Domest Anim Endocrinol ; 80: 106712, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35276581

RESUMO

The various fibroblast growth factors (FGF) regulate their function via binding to 4 main FGF receptor (FGFR) subtypes and their splice variants, FGFR1b, FGF1c, FGFR2b, FGFR2c and FGFR3c and FGFR4, but which of these FGFR are expressed in the granulosa (GC) and theca cells (TC), the 2 main cell layers of ovarian follicles, or change during follicular development is unknown. We hypothesized that FGFR1c, FGFR2c and FGFR3c (but not FGFR4) gene expression in GC (but not TC) would change with follicular development. Hence, the objective of this study was to determine if abundance of FGFR1c, FGFR2c, FGFR3c, and FGFR4 mRNA change according to follicular size, steroidogenic status, and days post-ovulation during growth of first-wave dominant follicles in Holstein cattle exhibiting regular estrous cycles. Estrous cycles of non-lactating dairy cattle were synchronized, and ovaries were collected on either d 3 to 4 (n = 8) or d 5 to 6 (n = 8) post-ovulation for GC and TC RNA extraction from small (1-5 mm), medium (5.1 to 8 mm) or large (8.1-18 mm) follicles for real-time PCR analysis. In GC, FGFR1c and FGFR2c mRNA relative abundance was greater in estrogen (E2)-inactive (ie, concentrations of E2 < progesterone, P4) follicles of all sizes than in GC from large E2-active follicles (ie, E2 > P4), whereas FGFR3c and FGFR4 mRNA abundance did not significantly differ among follicle types or days post-estrus. In TC, medium E2-inactive follicles had greater FGFR1c and FGFR4 mRNA abundance than large E2-active and E2-inactive follicles on d 5 to 6 post-ovulation whereas FGFR2c and FGFR3c mRNA abundance did not significantly differ among follicle types or day post-estrus. In vitro experiments revealed that androstenedione increased abundance of FGFR1c, FGFR2c and FGFR4 mRNA in GC whereas estradiol decreased FGFR2c mRNA abundance. Neither androstenedione nor estradiol affected abundance of the various FGFR mRNAs in cultured TC. Taken together, the findings that FGFR1c and FGFR2c mRNA abundance was less in GC of E2-active follicles and FGFR1c and FGFR4 mRNA was greater in TC of medium inactive follicles at late than at early growing phase of the first dominant follicle support an anti-differentiation role for FGF and their FGFR as well as support the idea that steroid-induced changes in FGF and their receptors may regulate selection of dominant follicles in cattle.


Assuntos
Androstenodiona , Células Tecais , Androstenodiona/análise , Androstenodiona/metabolismo , Animais , Bovinos , Estradiol/metabolismo , Feminino , Células da Granulosa/metabolismo , Ovário/metabolismo , RNA Mensageiro/análise , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/genética , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/metabolismo , Células Tecais/metabolismo
5.
J Vet Cardiol ; 41: 121-127, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35320744

RESUMO

A 10½-year-old, male neutered, pug presented with increasing ascites over two months. Echocardiography revealed cor triatriatum dexter with no concurrent cardiovascular anomalies, subsequently confirmed by computed tomography angiography. Balloon dilation of the perforated intra-atrial membrane under fluoroscopic guidance resulted in the transient resolution of all clinical abnormalities, but six months later stenosis and ascites recurred. After repeated balloon dilation, a stent was placed across the membrane. The dog remains asymptomatic fourteen months after the second procedure. One noteworthy feature of this case is the onset of congestive heart failure due to a congenital defect only at more than 10 years of age.


Assuntos
Coração Triatriado , Doenças do Cão , Insuficiência Cardíaca , Animais , Ascite/veterinária , Coração Triatriado/complicações , Coração Triatriado/veterinária , Doenças do Cão/congênito , Doenças do Cão/diagnóstico por imagem , Doenças do Cão/cirurgia , Cães , Insuficiência Cardíaca/etiologia , Insuficiência Cardíaca/veterinária , Masculino , Stents/efeitos adversos , Stents/veterinária
6.
Nat Commun ; 12(1): 59, 2021 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-33397949

RESUMO

Superconductivity is among the most fascinating and well-studied quantum states of matter. Despite over 100 years of research, a detailed understanding of how features of the normal-state electronic structure determine superconducting properties has remained elusive. For instance, the ability to deterministically enhance the superconducting transition temperature by design, rather than by serendipity, has been a long sought-after goal in condensed matter physics and materials science, but achieving this objective may require new tools, techniques and approaches. Here, we report the transmutation of a normal metal into a superconductor through the application of epitaxial strain. We demonstrate that synthesizing RuO2 thin films on (110)-oriented TiO2 substrates enhances the density of states near the Fermi level, which stabilizes superconductivity under strain, and suggests that a promising strategy to create new transition-metal superconductors is to apply judiciously chosen anisotropic strains that redistribute carriers within the low-energy manifold of d orbitals.

7.
Phys Rev Lett ; 125(21): 217401, 2020 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-33274990

RESUMO

SrRuO_{3}, a ferromagnet with an approximately 160 K Curie temperature, exhibits a T^{2}-dependent dc resistivity below ≈30 K. Nevertheless, previous optical studies in the infrared and terahertz range show non-Drude dynamics at low temperatures, which seem to contradict Fermi-liquid predictions. In this work, we measure the low-frequency THz range response of thin films with residual resistivity ratios, ρ_{300K}/ρ_{4K}≈74. At temperatures below 30 K, we find both a sharp zero frequency mode which has a width narrower than k_{B}T/ℏ as well as a broader zero frequency Lorentzian that has at least an order of magnitude larger scattering. Both features have temperature dependences consistent with a Fermi liquid with the wider feature explicitly showing a T^{2} scaling. Above 30 K, there is a crossover to a regime described by a single Drude peak that we believe arises from strong interband electron-electron scattering. Such two channel Drude transport sheds light on reports of the violation of Matthiessen's rule and extreme sensitivity to disorder in metallic ruthenates.

8.
J Vet Cardiol ; 32: 33-39, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33091799

RESUMO

In a 6-month-old, intact female, Japanese spitz presenting with severe dyspnea, lung ultrasonography revealed confluent B lines associated with severe echocardiographic left sided volume overload and systolic dysfunction. A congenital shunt or valvular dysplasia was not demonstrable. On electrocardiogram, there was a constant sinus rhythm, respectively sinus tachycardia. Cardiac troponin I was normal. Within 2 days of admission, the dog died of heart failure. On macroscopic postmortem examination, the left ventricle and atrium were markedly dilated, and the left ventricular endocardium had a mild diffuse whitish appearance. Histopathology revealed moderate to severe thickening of the left ventricular endocardium, composed mostly of abundant elastic fibers and fewer collagen fibers, diagnostic for endocardial fibroelastosis. In addition, there were mild degenerative changes of the atrioventricular valves. Endocardial fibroelastosis is a rare congenital disease and should be considered in a young dog if more common causes of echocardiographic dilated cardiomyopathy phenotype are ruled out.


Assuntos
Doenças do Cão/diagnóstico , Fibroelastose Endocárdica/veterinária , Insuficiência Cardíaca/veterinária , Animais , Diagnóstico Diferencial , Doenças do Cão/diagnóstico por imagem , Doenças do Cão/fisiopatologia , Cães , Dispneia/etiologia , Dispneia/veterinária , Ecocardiografia/veterinária , Fibroelastose Endocárdica/complicações , Fibroelastose Endocárdica/diagnóstico , Feminino , Insuficiência Cardíaca/complicações , Insuficiência Cardíaca/diagnóstico , Linhagem
9.
Schweiz Arch Tierheilkd ; 161(11): 749-754, 2019 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-31685448

RESUMO

INTRODUCTION: Caval syndrome due to infection with Dirofilaria (D.) immitis is a life-threatening situation, needing immediate therapeutic intervention. Severe pulmonary hypertension due to dirofilariosis was diagnosed echocardiographically in a 3.6 kg dog with heart failure and moderate hemolytic anemia. A ball of adult worms was visualized in the tricuspid valve area. Using a modified pigtail catheter, these worms were removed under fluoroscopic guidance by a transvenous approach. Already intraoperatively the hemodynamic condition improved. Subsequently, additional routine adulticide treatment was performed without complications. Over the following weeks the severe pulmonary hypertension normalized slowly but steadily. Manual extraction of adult D. immitis can be achieved with relatively simple tools and allows rapid stabilization of a critically sick patient.


INTRODUCTION: Le syndrome cave supérieur dû à une infestation à ­Dirofilaria (D.) immitis est une situation potentiellement mortelle nécessitant un traitement immédiat. Une hypertension pulmonaire sévère due à la dirofilariose a été diagnostiquée par échocardiographie chez un chien de 3,6 kg présentant une insuffisance cardiaque et une anémie hémolytique modérée. Une boule de vers adultes a été visualisée dans la région de la valvule tricuspide. En utilisant un cathéter queue de cochon modifié, ces vers ont été retirés sous guidage fluoroscopique par une approche transveineuse. Déjà durant l'opération, l'état hémodynamique s'est amélioré. Par la suite, un traitement adulticide de routine supplémentaire a été réalisé sans complications. Au cours des semaines suivantes, l'hypertension artérielle pulmonaire sévère s'est normalisée lentement mais régulièrement. L'extraction manuelle de D. immitis adultes peut être réalisée avec des outils relativement simples et permet la stabilisation rapide d'un patient gravement atteint.


Assuntos
Dirofilariose/complicações , Dirofilariose/cirurgia , Doenças do Cão/cirurgia , Hipertensão Pulmonar/veterinária , Animais , Dirofilaria immitis , Dirofilariose/tratamento farmacológico , Doenças do Cão/diagnóstico , Doenças do Cão/tratamento farmacológico , Cães , Ecocardiografia/veterinária , Filaricidas/uso terapêutico , Hipertensão Pulmonar/etiologia , Resultado do Tratamento
10.
Phys Rev Lett ; 122(24): 247201, 2019 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-31322403

RESUMO

Trilayer nickelates, which exhibit a high degree of orbital polarization combined with an electron count (d^{8.67}) corresponding to overdoped cuprates, have been identified as a promising candidate platform for achieving high-T_{c} superconductivity. One such material, La_{4}Ni_{3}O_{8}, undergoes a semiconductor-insulator transition at ∼105 K, which was recently shown to arise from the formation of charge stripes. However, an outstanding issue has been the origin of an anomaly in the magnetic susceptibility at the transition and whether it signifies the formation of spin stripes akin to single layer nickelates. Here we report single crystal neutron diffraction measurements (both polarized and unpolarized) that establish that the ground state is indeed magnetic. The ordering is modeled as antiferromagnetic spin stripes that are commensurate with the charge stripes, the magnetic ordering occurring in individual trilayers that are essentially uncorrelated along the crystallographic c axis. A comparison of the charge and spin stripe order parameters reveals that, in contrast to single-layer nickelates such as La_{2-x}Sr_{x}NiO_{4} as well as related quasi-2D oxides including manganites, cobaltates, and cuprates, these orders uniquely appear simultaneously, thus demonstrating a stronger coupling between spin and charge than in these related low-dimensional correlated oxides.

11.
Phys Rev Lett ; 122(10): 101102, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30932663

RESUMO

During its orbit around the four million solar mass black hole Sagittarius A* the star S2 experiences significant changes in gravitational potential. We use this change of potential to test one part of the Einstein equivalence principle: the local position invariance (LPI). We study the dependency of different atomic transitions on the gravitational potential to give an upper limit on violations of the LPI. This is done by separately measuring the redshift from hydrogen and helium absorption lines in the stellar spectrum during its closest approach to the black hole. For this measurement we use radial velocity data from 2015 to 2018 and combine it with the gravitational potential at the position of S2, which is calculated from the precisely known orbit of S2 around the black hole. This results in a limit on a violation of the LPI of |ß_{He}-ß_{H}|=(2.4±5.1)×10^{-2}. The variation in potential that we probe with this measurement is six magnitudes larger than possible for measurements on Earth, and a factor of 10 larger than in experiments using white dwarfs. We are therefore testing the LPI in a regime where it has not been tested before.

12.
Domest Anim Endocrinol ; 63: 48-58, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29413902

RESUMO

We reported previously that fibroblast growth factor 9 (FGF9) acts as an antidifferentiation factor, stimulating proliferation of granulosa cells (GCs) and theca cells (TCs) while suppressing hormone-induced steroidogenesis of these cells. How FGF9 acts to simultaneously suppress steroidogenesis and stimulate proliferation remains to be fully elucidated. Thus, this study was undertaken to clarify the effects of FGF9 on the TC transcriptome. Ovaries were obtained from beef heifers at a local abattoir, TCs were isolated from large antral follicles, and cultured with or without 30 ng/mL of FGF9 for 24 h in the presence of LH and IGF-1. After treatment, total RNA was extracted from TC and processed for microarray using Affymetrix GeneChip Bovine Genome Arrays (n = 4/group). Transcriptome analysis comparing FGF9-treated TC with control TC using 1.3-fold cutoff, and a P < 0.05 significance level identified 355 differentially expressed transcripts, with 164 elements upregulated and 191 elements downregulated by FGF9. The ingenuity pathway analysis (IPA) was used to investigate how FGF9 treatment affects molecular pathways, biological functions, and the connection between molecules in bovine TC. The IPA software identified 346 pathways in response to FGF9 in TC involved in several biological functions and unveiled interesting relationships among genes related to cell proliferation (eg, CCND1, FZD5, and MYB), antioxidation/cytoprotection (eg, HMOX1 and NQO1), and steroidogenesis (eg, CYP11A1 and STAR). Overall, genes, pathways, and networks identified in this study painted a picture of how FGF9 may regulate folliculogenesis, providing novel candidate genes for further investigation of FGF9 functions in ovarian follicular development.


Assuntos
Bovinos , Fator 9 de Crescimento de Fibroblastos/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Células Tecais/efeitos dos fármacos , Células Tecais/metabolismo , Animais , Regulação para Baixo , Feminino , Análise Serial de Proteínas , Regulação para Cima
13.
Nature ; 543(7645): 397-401, 2017 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-28300118

RESUMO

In the cold dark matter cosmology, the baryonic components of galaxies-stars and gas-are thought to be mixed with and embedded in non-baryonic and non-relativistic dark matter, which dominates the total mass of the galaxy and its dark-matter halo. In the local (low-redshift) Universe, the mass of dark matter within a galactic disk increases with disk radius, becoming appreciable and then dominant in the outer, baryonic regions of the disks of star-forming galaxies. This results in rotation velocities of the visible matter within the disk that are constant or increasing with disk radius-a hallmark of the dark-matter model. Comparisons between the dynamical mass, inferred from these velocities in rotational equilibrium, and the sum of the stellar and cold-gas mass at the peak epoch of galaxy formation ten billion years ago, inferred from ancillary data, suggest high baryon fractions in the inner, star-forming regions of the disks. Although this implied baryon fraction may be larger than in the local Universe, the systematic uncertainties (owing to the chosen stellar initial-mass function and the calibration of gas masses) render such comparisons inconclusive in terms of the mass of dark matter. Here we report rotation curves (showing rotation velocity as a function of disk radius) for the outer disks of six massive star-forming galaxies, and find that the rotation velocities are not constant, but decrease with radius. We propose that this trend arises because of a combination of two main factors: first, a large fraction of the massive high-redshift galaxy population was strongly baryon-dominated, with dark matter playing a smaller part than in the local Universe; and second, the large velocity dispersion in high-redshift disks introduces a substantial pressure term that leads to a decrease in rotation velocity with increasing radius. The effect of both factors appears to increase with redshift. Qualitatively, the observations suggest that baryons in the early (high-redshift) Universe efficiently condensed at the centres of dark-matter haloes when gas fractions were high and dark matter was less concentrated.

14.
Domest Anim Endocrinol ; 59: 90-99, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28040605

RESUMO

Abundance of G protein-coupled receptor 34 (GPR34) mRNA is greater in granulosa cells (GCs) of cystic vs normal follicles of cattle. The present experiments were designed to determine if GPR34 mRNA in granulosa cell [GC] changes during selection and growth of dominant follicles in cattle as well as to investigate the hormonal regulation of GPR34 mRNA in bovine GC in vitro. In Exp. 1, estrous cycles of nonlactating cows were synchronized and then ovariectomized on either day 3-4 or 5-6 after ovulation. GPR34 mRNA abundance in GC was 2.8- to 3.8-fold greater (P < 0.05) in small (1-5 mm) and large (≥8 mm) estrogen-inactive dominant follicles than in large estrogen-active follicles. Also, GPR34 mRNA tended to be greater (P < 0.10) in F2 than F1 follicles on day 3-4 postovulation. In Exp. 2-7, ovaries were collected at an abattoir and GC were isolated and treated in vitro. Expression of GPR34 was increased (P < 0.05) 2.2-fold by IGF1. Tumor necrosis factor (TNF)-α decreased (P < 0.05) the IGF1-induced GPR34 mRNA abundance in small-follicle GC, whereas IGF1 decreased (P < 0.05) GPR34 expression by 45% in large-follicle GC. Treatment of small-follicle GC with either IL-2, prostaglandin E2 or angiogenin decreased (P < 0.05) GPR34 expression, whereas FSH, cortisol, wingless 3A, or hedgehog proteins did not affect (P > 0.10) GPR34 expression. In Exp. 6 and 7, 2 presumed ligands of GPR34, L-a-lysophosphatidylserine (LPPS) and LPP-ethanolamine, increased (P < 0.05) GC numbers and estradiol production by 2-fold or more in small-follicle GC, and this response was only observed in IGF1-treated GC. In conclusion, GPR34 is a developmentally and hormonally regulated gene in GC, and its presumed ligands enhance IGF1-induced proliferation and steroidogenesis of bovine GC.


Assuntos
Bovinos/fisiologia , Células da Granulosa/metabolismo , Folículo Ovariano/crescimento & desenvolvimento , Receptores de Lisofosfolipídeos/metabolismo , Animais , Células Cultivadas , Citocinas/farmacologia , Feminino , Regulação da Expressão Gênica/fisiologia , Células da Granulosa/efeitos dos fármacos , Fator de Crescimento Insulin-Like I/farmacologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de Lisofosfolipídeos/genética
15.
Animal ; 11(5): 811-819, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-27760586

RESUMO

Angiogenin is a member of the ribonuclease A superfamily of proteins that has been implicated in stimulating angiogenesis but whether angiogenin can directly affect ovarian granulosa or theca cell function is unknown. Therefore, the objective of these studies was to determine the effect of angiogenin on proliferation and steroidogenesis of bovine granulosa and theca cells. In experiments 1 and 2, granulosa cells from small (1 to 5 mm diameter) follicles and theca cells from large (8 to 22 mm diameter) follicles were cultured to evaluate the dose-response effect of recombinant human angiogenin on steroidogenesis. At 30 and 100 ng/ml, angiogenin inhibited (P0.10) granulosa cell estradiol production or theca cell progesterone production, and did not affect numbers of granulosa or theca cells. In experiments 3 and 4, granulosa and theca cells from both small and large follicles were cultured with 300 ng/ml of angiogenin to determine if size of follicle influenced responses to angiogenin. At 300 ng/ml, angiogenin increased large follicle granulosa cell proliferation but decreased small follicle granulosa cell progesterone and estradiol production and large follicle theca cell progesterone production. In experiments 5 and 6, angiogenin stimulated (P<0.05) proliferation and DNA synthesis in large follicle granulosa cells. In experiment 7, 300 ng/ml of angiogenin increased (P<0.05) CYP19A1 messenger RNA (mRNA) abundance in granulosa cells but did not affect CYP11A1 mRNA abundance in granulosa or theca cells and did not affect CYP17A1 mRNA abundance in theca cells. We conclude that angiogenin appears to target both granulosa and theca cells in cattle, but additional research is needed to further understand the mechanism of action of angiogenin in granulosa and theca cells, as well as its precise role in folliculogenesis.


Assuntos
Bovinos/crescimento & desenvolvimento , Bovinos/metabolismo , Células da Granulosa/efeitos dos fármacos , Folículo Ovariano/efeitos dos fármacos , Ribonuclease Pancreático/administração & dosagem , Células Tecais/efeitos dos fármacos , Animais , Relação Dose-Resposta a Droga , Feminino , Humanos , Folículo Ovariano/crescimento & desenvolvimento
16.
J Dairy Sci ; 99(11): 9143-9151, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27614836

RESUMO

Fibroblast growth factor 9 (FGF9) has been suggested to act as an antidifferentiation factor in cattle by reducing steroidogenesis and increasing cell proliferation in granulosa (GC) and theca (TC) cells. The objective of this study was to characterize FGF9 mRNA abundance in GC and TC during development of dominant follicles in dairy cattle. Estrous cycles of nonlactating dairy cattle were synchronized, and ovaries were collected on either d 3 to 4 (n=8) or 5 to 6 (n=8) postovulation for GC and TC RNA extraction from small (1-5mm), medium (5.1-8mm), and large (8.1-18mm) follicles for PCR analysis. The FGF9 mRNA abundance was greater in GC than in TC. In GC, FGF9 mRNA abundance was greater in small, medium, and large estrogen-inactive [i.e., concentrations of estradiol (E2)P4) follicles at both early (d 3-4) and late (d 5-6) growing phases of first dominant follicle. Abundance of FGF9 mRNA increased in medium-sized follicles from early to late growing phase of the dominant follicle. In TC, FGF9 mRNA abundance was greater in large E2-inactive follicles than in large E2-active follicles on d 3 to 4 postovulation; no significant differences in TC FGF9 mRNA existed among follicle types on d 5 to 6 postovulation. Correlations among levels of follicular fluid hormones and FGF9 mRNA levels revealed significant negative correlations between GC FGF9 mRNA abundance and follicular fluid E2 (r=-0.68), free IGF-1 (r=-0.63), and E2-to-P4 ratio (r=-0.58). In summary, abundance of FGF9 mRNA in GC and TC increases in medium-sized follicles during development of dominant follicles and is less in dominant E2-active than subordinate E2-inactive follicles, suggesting that FGF9 signaling could contribute to normal follicle development and steroidogenesis in dairy cattle.


Assuntos
Fator 9 de Crescimento de Fibroblastos , Células Tecais , Animais , Bovinos , Estradiol , Feminino , Células da Granulosa/metabolismo , Folículo Ovariano/química , Progesterona , RNA Mensageiro/metabolismo
17.
Domest Anim Endocrinol ; 55: 32-40, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26773365

RESUMO

Brain ribonuclease (BRB) is a member of the ribonuclease A superfamily that is constitutively expressed in a range of tissues and is the functional homolog of human ribonuclease 1. This study was designed to characterize BRB gene expression in granulosa cells (GCs) during development of bovine dominant ovarian follicles and to determine the hormonal regulation of BRB in GCs. Estrous cycles of Holstein cows (n = 18) were synchronized, and cows were ovariectomized on either day 3 to 4 or day 5 to 6 after ovulation during dominant follicle growth and selection. Ovaries were collected, follicular fluid (FFL) was aspirated, and GCs were collected for RNA isolation and quantitative polymerase chain reaction. Follicles were categorized as small (1-5 mm; pooled per ovary), medium (5-8 mm; individually collected), or large (8.1-17 mm; individually collected) based on surface diameter. Estradiol (E2) and progesterone (P4) levels were measured by radioimmunoassay (RIA) in FFL. Abundance of BRB messenger RNA (mRNA) in GCs was 8.6- to 11.8-fold greater (P < 0.05) in small (n = 31), medium (n = 66), and large (n = 33) subordinate E2-inactive (FFL E2 < P4) follicles than in large (n = 16) dominant E2-active (FFL E2 > P4) follicles. In the largest 4 follicles, GCs BRB mRNA abundance was negatively correlated (P < 0.01) with FFL E2 (r = -0.65) and E2:P4 ratio (r = -0.46). In experiment 2, GCs from large (8-22 mm diameter) and small (1-5 mm diameter) follicles were treated with insulin-like growth factor 1 (IGF1; 0 or 30 ng/mL) and/or tumor necrosis factor alpha (0 or 30 ng/mL); IGF1 increased (P < 0.05) BRB mRNA abundance, and tumor necrosis factor alpha decreased (P < 0.001) the IGF1-induced BRB mRNA abundance in large-follicle GCs. In experiment 3 to 6, E2, follicle-stimulating hormone, fibroblast growth factor 9, cortisol, wingless 3A, or sonic hedgehog did not affect (P > 0.10) abundance of BRB mRNA in GCs; thyroxine and luteinizing hormone increased (P < 0.05), whereas prostaglandin E2 (PGE2) decreased (P < 0.05) BRB mRNA abundance in small-follicle GCs. Treatment of small-follicle GCs with recombinant human RNase1 increased (P < 0.05) GCs numbers and E2 production. In conclusion, BRB is a hormonally and developmentally regulated gene in bovine GCs and may regulate E2 production during follicular growth in cattle.


Assuntos
Encéfalo/enzimologia , Regulação da Expressão Gênica/fisiologia , Células da Granulosa/metabolismo , RNA Mensageiro/metabolismo , Ribonucleases/genética , Animais , Bovinos , Estradiol/metabolismo , Feminino , Ovulação/fisiologia , Progesterona/metabolismo , RNA Mensageiro/genética
18.
Science ; 348(6232): 314-7, 2015 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-25883353

RESUMO

Most present-day galaxies with stellar masses ≥10(11) solar masses show no ongoing star formation and are dense spheroids. Ten billion years ago, similarly massive galaxies were typically forming stars at rates of hundreds solar masses per year. It is debated how star formation ceased, on which time scales, and how this "quenching" relates to the emergence of dense spheroids. We measured stellar mass and star-formation rate surface density distributions in star-forming galaxies at redshift 2.2 with ~1-kiloparsec resolution. We find that, in the most massive galaxies, star formation is quenched from the inside out, on time scales less than 1 billion years in the inner regions, up to a few billion years in the outer disks. These galaxies sustain high star-formation activity at large radii, while hosting fully grown and already quenched bulges in their cores.

19.
J Anim Sci ; 92(2): 511-9, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24664559

RESUMO

The objectives of this study were to investigate the effects of fibroblast growth factor 9 (FGF9) on hormone-stimulated porcine granulosa cell proliferation and steroid production and to further elucidate the hormonal and developmental control of FGFR2IIIc gene expression in granulosa cells. Porcine ovaries were collected from a local slaughterhouse and granulosa cells were collected from small to medium (1 to 5 mm) follicles for 5 in vitro studies that were conducted. Cells were cultured for 48 h in 5% fetal calf serum plus 5% porcine serum and then treated with various combinations of FSH, IGF-I, FGF9, Sonic hedgehog (SHH), cortisol, PGE2, and/or wingless-type mouse mammary tumor virus integration site family member 5A (WNT5A) in serum-free medium for an additional 24 or 48 h. Medium was collected for analysis of steroid concentration via RIA, or RNA was collected for gene expression analysis of FGFR2IIIc via quantitative reverse transcription PCR. Fibroblast growth factor 9 stimulated (P < 0.05) IGF-I-induced estradiol production in the presence of FSH and testosterone. However, FGF9 had inconsistent effects on progesterone production, stimulating progesterone production in the presence of FSH and testosterone but inhibiting progesterone production in the presence of IGF-I, FSH, and testosterone. Cell numbers were increased (P < 0.05) by FGF9 in the presence of IGF-I and FSH but not in the presence of FSH and absence of IGF-I. For FGFR2IIIc mRNA studies, granulosa cells were treated with FSH, IGF-I, FGF9, SHH, cortisol, PGE2, or WNT5A. Follicle-stimulating hormone alone had no effect (P > 0.10) whereas IGF-I increased (P < 0.05) FGFR2IIIc mRNA abundance. Cortisol, PGE2, SHH, and WNT5A had no effect (P > 0.10) on FGFR2IIIc gene expression whereas FGF9 in the presence of FSH and IGF-I inhibited (P < 0.05) FGFR2IIIc gene expression. In an in vivo study, granulosa cells from large (7 to 14 mm) follicles had greater (P < 0.05) abundance of FGFR2IIIc mRNA than small (1 to 3 mm) or medium (4 to 6 mm) follicles. In conclusion, IGF-I-induced FGFR2IIIc mRNA may be a mechanism for increased responses to FGF9 in FSH plus IGF-I-treated granulosa cells. Fibroblast growth factor 9 and IGF-I may work together as amplifiers of follicular growth and granulosa cell differentiation by stimulating estradiol production and concomitantly stimulating granulosa cell growth in pigs.


Assuntos
Fator 9 de Crescimento de Fibroblastos/metabolismo , Células da Granulosa/metabolismo , RNA Mensageiro/metabolismo , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/metabolismo , Suínos/fisiologia , Animais , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Feminino , Fator 9 de Crescimento de Fibroblastos/genética , Hormônio Foliculoestimulante/farmacologia , Regulação da Expressão Gênica , Proteínas Hedgehog/farmacologia , Fator de Crescimento Insulin-Like I/farmacologia , RNA Mensageiro/genética , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/genética
20.
J Endocrinol ; 215(1): 167-75, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22872763

RESUMO

Fibroblast growth factor 9 (FGF9) protein affects granulosa cell (GC) function but is mostly localized to theca cell (TC) and stromal cell of rat ovaries. The objectives of this study were to determine the 1) effects of FGF9 on TC steroidogenesis, gene expression, and cell proliferation; 2) mechanism of action of FGF9 on TCs; and 3) hormonal control of FGF9 mRNA expression in TCs. Bovine ovaries were collected from a local slaughterhouse and TCs were collected from large (8-22 mm) follicles and treated with various hormones in serum-free medium for 24 or 48 h. FGF9 caused a dose-dependent inhibition (P<0·05) of LH- and LH+IGF1-induced androstenedione and progesterone production. Also, FGF9 inhibited (P<0·05) LH+IGF1-induced expression of LHCGR, CYP11A1, and CYP17A1 mRNA (via real-time RT-PCR) in TCs. FGF9 had no effect (P>0·10) on STAR mRNA abundance. Furthermore, FGF9 inhibited dibutyryl cAMP-induced progesterone and androstenedione production in LH+IGF1-treated TCs. By contrast, FGF9 increased (P<0·05) the number of bovine TCs. Abundance of FGF9 mRNA in GCs and TCs was several-fold greater (P<0·05) in small (1-5 mm) vs large follicles. Tumor necrosis factor α and WNT5A increased (P<0·05) abundance of FGF9 mRNA in TCs. In summary, expression of FGF9 mRNA in TCs is developmentally and hormonally regulated. FGF9 may act as an autocrine regulator of ovarian function in cattle by slowing TC differentiation via inhibiting LH+IGF1 action via decreasing gonadotropin receptors and the cAMP signaling cascade while stimulating proliferation of TCs.


Assuntos
Fator 9 de Crescimento de Fibroblastos/genética , Fator 9 de Crescimento de Fibroblastos/farmacologia , Células Tecais/efeitos dos fármacos , Células Tecais/metabolismo , Animais , Bovinos , Contagem de Células , Proliferação de Células/efeitos dos fármacos , Tamanho Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Feminino , Fator 9 de Crescimento de Fibroblastos/metabolismo , Expressão Gênica/efeitos dos fármacos , Fator de Crescimento Insulin-Like I/farmacologia , Folículo Ovariano/anatomia & histologia , Folículo Ovariano/efeitos dos fármacos , Folículo Ovariano/metabolismo , Esteroides/biossíntese , Células Tecais/citologia , Células Tecais/fisiologia
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