Publications search

Found 37769 matches. Displaying 3431-3440
Roy S, Gandra D, Seger C, Biswas A, Kushnir VA, Gleicher N, Kumar TR, Sen A
Show All Authors

Oocyte-Derived Factors (GDF9 and BMP15) and FSH Regulate AMH Expression Via Modulation of H3K27AC in Granulosa Cells

ENDOCRINOLOGY 2018 SEP; 159(9):3433-3445
Anti-Mullerian hormone (AMH) produced by ovarian granulosa cells (GCs) plays a crucial role in ovarian function. It is used as a diagnostic and/or prognostic marker of fertility as well as for pathophysiological conditions in women. In this study, we investigated the underlying mechanism for regulation of AMH expression in GCs using primary mouse GCs and a human GC tumor-derived KGN cell line. We find that growth differentiation factor 9 (GDF9) and bone morphogenetic factor 15 (BMP15) together (GDF9 + BMP15), but not when tested separately, significantly induce AMH expression in vitro and in vivo (serum AMH). Our results show that GDF9 + BMP15 through the PI3K/Akt and Smad2/3 pathways synergistically recruit the coactivator p300 on the AMH promoter region that promotes acetylation of histone 3 lysine 27 (H3K27ac), facilitating AMH/Amh expression. Intriguingly, we also find that FSH inhibits GDF9 + BMP15-induced increase of AMH/Amh expression. This inhibition occurs through FSH-induced protein kinase A/SF1-mediated expression of gonadotropin inducible ovarian transcription factor 1, a transcriptional repressor, that recruits histone deacetylase 2 to deacetylate H3K27ac, resulting in the suppression of AMH/Amh expression. Furthermore, we report that ovarian Amh mRNA levels are significantly higher in Fshb-null mice (Fsh beta(-/-)) compared with those in wild-type (WT) mice. In addition, ovarian Amh mRNA levels are restored in Fshb-null mice expressing a human WT FSHb transgene (FSH beta(-/-)hFSH beta(WT)). Our study provides a mechanistic insight into the regulation of AMH expression that has many implications in female reproduction/fertility.
Kratz K, de Lange T
Show All Authors

Protection of telomeres 1 proteins POT1a and POT1b can repress ATR signaling by RPA exclusion, but binding to CST limits ATR repression by POT1b

JOURNAL OF BIOLOGICAL CHEMISTRY 2018 SEP 14; 293(37):14384-14392
Comprised of telomeric TTAGGG repeats and shelterin, telomeres ensure that the natural ends of chromosomes remain impervious to the DNA damage response. Telomeres carry a long constitutive 3 overhang that can bind replication protein A (RPA) and activate the ATR Ser/Thr kinase (ATR), which induces cell cycle arrest. A single-stranded (ss) TTAGGG repeat-binding protein in mouse shelterin, POT1a, has been proposed to repress ATR signaling by preventing RPA binding. Repression of ATR at telomeres requires tethering of POT1a to the other shelterin subunits situated on the double-stranded (ds) telomeric DNA. The simplest model of ATR repression, the tethered exclusion model, suggests that the only critical features of POT1a are its connection to shelterin and its binding to ss telomeric DNA. In agreement with the model, we show here that a shelterin-tethered variant of RPA70 (lacking the ATR recruitment domain) can repress ATR signaling at telomeres that lack POT1a. However, arguing against the tethered exclusion model, the nearly identical POT1b subunit of shelterin has been shown to be much less proficient than POT1a in repression of ATR. We now show that POT1b has the intrinsic ability to fully repress ATR but is prevented from doing so when bound to Ctc1, Stn1, Ten1 (CST), the complex needed for telomere end processing. These results establish that shelterin represses ATR with a tethered ssDNA-binding domain that excludes RPA from the 3 overhang and also reveal an unexpected effect of CST on the ability of POT1b to repress ATR.
Butelman ER, Chen CY, Fry RS, Kimani R, Levran O, Ott J, da Rosa JC, Kreek MJ
Show All Authors

Re-evaluation of the KMSK scales, rapid dimensional measures of self-exposure to specific drugs: Gender-specific features

DRUG AND ALCOHOL DEPENDENCE 2018 SEP 1; 190(?):179-187
Background: The Kreek-McHugh-Schluger-Kellogg (KMSK) scales provide a rapid assessment of maximal self-exposure to specific drugs and can be used as a dimensional instrument. This study provides a re-evaluation of the KMSK scales for cannabis, alcohol, cocaine, and heroin in a relatively large multi-ethnic cohort, and also the first systematic comparison of gender-specific profiles of drug exposure with this scale. Methods: This was an observational study of n = 1,133 consecutively ascertained adult volunteers. The main instruments used were the SCID-I interview (DSM-IV criteria) and KMSK scales for cannabis, alcohol, cocaine, and heroin. Results: Participants were 852 volunteers (297 female) with specific DSM-IV abuse or dependence diagnoses, and 281 volunteers without any drug diagnoses (154 female). Receiver operating characteristic (ROC) curves were calculated for concurrent validity of KMSK scores with the respective DSM-IV dependence diagnoses. The areas under the ROC curves for men and women combined were 99.5% for heroin, 97% for cocaine, 93% for alcohol, and 85% for cannabis. Newly determined optimal KMSK "cutpoint" scores were identical for men and women for cocaine and heroin dependence diagnoses, but were higher in men than in women, for cannabis and alcohol dependence diagnoses. Conclusions: This study confirms the scales' effectiveness in performing rapid dimensional analyses for cannabis, alcohol, cocaine, and heroin exposure, in a cohort larger than previously reported, with "cutpoints" changed from initial determinations, based on this larger sample. The KMSK scales also detected gender differences in self-exposure to alcohol and cannabis that are associated with the respective dependence diagnoses.
Jong SJ, Crequer A, Matos I, Hum D, Gunasekharan V, Lorenzo L, Jabot-Hanin F, Imahorn E, Arias AA, Vahidnezhad H, Youssefian L, Markle JG, Patin E, D'Amico A, Wang CQF, Full F, Ensser A, Leisner TM, Parise LV, Bouaziz M, Maya N, Cadena X, Saka B, Saeidian AH, Aghazadeh N, Zeinali S, Itin P, Krueger JG, Laimins L, Abel L, Fuchs E, Uitto J, Franco J, Burger B, Orth G, Jouanguy E, Casanova JL
Show All Authors

The human CIB1-EVER1-EVER2 complex governs keratinocyte-intrinsic immunity to beta-papillomaviruses

JOURNAL OF EXPERIMENTAL MEDICINE 2018 SEP; 215(9):2289-2310
Patients with epidermodysplasia verruciformis (EV) and biallelic null mutations of TMC6 (encoding EVER1) or TMC8 (EVER2) are selectively prone to disseminated skin lesions due to keratinocyte-tropic human beta-papillomaviruses (beta-HPVs), which lack E5 and E8. We describe EV patients homozygous for null mutations of the CIB1 gene encoding calcium-and integrin-binding protein-1 (CIB1). CIB1 is strongly expressed in the skin and cultured keratinocytes of controls but not in those of patients. CIB1 forms a complex with EVER1 and EVER2, and CIB1 proteins are not expressed in EVER1- or EVER2-deficient cells. The known functions of EVER1 and EVER2 in human keratinocytes are not dependent on CIB1, and CIB1 deficiency does not impair keratinocyte adhesion or migration. In keratinocytes, the CIB1 protein interacts with the HPV E5 and E8 proteins encoded by alpha-HPV16 and gamma-HPV4, respectively, suggesting that this protein acts as a restriction factor against HPVs. Collectively, these findings suggest that the disruption of CIB1-EVER1-EVER2-dependent keratinocyte-intrinsic immunity underlies the selective susceptibility to beta-HPVs of EV patients.
Vukmanovic-Stejic M, Chambers ES, Suarez-Farinas M, Sandhu D, Fuentes-Duculan J, Patel N, Agius E, Lacy KE, Turner CT, Larbi A, Birault V, Noursadeghi M, Mabbott NA, Rustin MHA, Krueger JG, Akbar AN
Show All Authors

Enhancement of cutaneous immunity during aging by blocking p38 mitogen-activated protein (MAP) kinase-induced inflammation

JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY 2018 SEP; 142(3):844-856
Background: Immunity decreases with age, which leads to reactivation of varicella zoster virus (VZV). In human subjects age-associated immune changes are usually measured in blood leukocytes; however, this might not reflect alterations in tissue specific immunity. Objectives: We used a VZV antigen challenge system in the skin to investigate changes in tissue-specific mechanisms involved in the decreased response to this virus during aging. Methods: We assessed cutaneous immunity based on the extent of erythema and induration after intradermal VZV antigen injection. We also performed immune histology and transcriptomic analyses on skin biopsy specimens taken from the challenge site in young (<40 years) and old (>65 years) subjects. Results: Old human subjects exhibited decreased erythema and induration, CD4+ and CD8+ T-cell infiltration, and attenuated global gene activation at the site of cutaneous VZV antigen challenge compared with young subjects. This was associated with increased sterile inflammation in the skin in the same subjects related to p38 mitogen-activated protein kinase-related proinflammatory cytokine production (P <.0007). We inhibited systemic inflammation in old subjects by means of pretreatment with an oral small-molecule p38 mitogen-activated protein kinase inhibitor (Losmapimod; GlaxoSmithKline, Brentford, United Kingdom), which reduced both serum C-reactive protein levels and peripheral blood monocyte secretion of IL-6 and TNF-alpha. In contrast, cutaneous responses to VZV antigen challenge were increased significantly in the same subjects (P <.0003). Conclusion: Excessive inflammation in the skin early after antigen challenge retards antigen-specific immunity. However, this can be reversed by inhibition of inflammatory cytokine production that can be used to promote vaccine efficacy and the treatment of infections and malignancy during aging.
Mucida D, Esterhazy D
Show All Authors

SnapShot: Gut Immune Niches

CELL 2018 SEP 6; 174(6):1600-1600.e1 Article 1600.e1
The intestinal milieu changes along the proximal to distal axis and across its tissue wall, according to the luminal content and tissue function. Correspondingly, highly specialized immune compartments can be found in each intestinal niche.
Wu HW, Deng SL, Xu HY, Mao HZ, Liu J, Niu QW, Wang H, Chua NH
Show All Authors

A noncoding RNA transcribed from the AGAMOUS (AG) second intron binds to CURLY LEAF and represses AG expression in leaves

NEW PHYTOLOGIST 2018 SEP; 219(4):1480-1491
Dispersed H3K27 trimethylation (H3K27me3) of the AGAMOUS (AG) genomic locus is mediated by CURLY LEAF (CLF), a component of the Polycomb Repressive Complex (PRC) 2. Previous reports have shown that the AG second intron, which confers AG tissue-specific expression, harbors sequences targeted by several positive and negative regulators. Using RACE reverse transcription polymerase chain reaction, we found that the AG intron 2 encodes several noncoding RNAs. RNAi experiment showed that incRNA4 is needed for CLF repressive activity. AG-incRNA4RNAi lines showed increased leaf AGmRNA levels associated with a decrease of H3K27me3 levels; these plants displayed AG overexpression phenotypes. Genetic and biochemical analyses demonstrated that the AG-incRNA4 can associate with CLF to repress AG expression in leaf tissues through H3K27me3-mediated repression and to autoregulate its own expression level. The mechanism of AG-incRNA4-mediated repression may be relevant to investigations on tissue-specific expression of Arabidopsis MADS-box genes.
Shapiro AJ, Darmon SK, Barad DH, Gleicher N, Kushnir VA
Show All Authors

Vitamin D levels are not associated with ovarian reserve in a group of infertile women with a high prevalance of diminished ovarian reserve

FERTILITY AND STERILITY 2018 SEP; 110(4):761-766.e1
Objective: To determine whether a relationship exists between vitamin D (25OH-D) levels and ovarian reserve parameters (antimullerian hormone [AMH] and FSH levels) in a large cohort of infertile women with a high prevalence of diminished ovarian reserve. Design: Retrospective cohort study. Setting: Academically affiliated private fertility center. Patient(s): A total of 457 infertile women 21-50 years of age who had baseline hormone measurements. Intervention(s): None. Main Outcome Measure(s): Statistical analyses to determine whether a relationship exists between AMH, FSH, and serum 25OH-D levels. Result(s): As defined by 25OH-D <20.0 ng/mL, 74/457 patients (16.2%) had vitamin D deficiency. AMH and FSH levels did not vary between women with vitamin D deficiency and those with normal levels (0.8 +/- 3.0 vs. 0.5 +/- 1.6 ng/mL [P = .18] and 9.4 +/- 7.2 vs. 9.2 +/- 9.5 mIU/mL [P = .54], respectively). Multivariate linear regression analysis of log-transformed AMH and FSH with 25OH-D levels adjusted for age, body mass index, and seasonal variation confirmed lack of association. Receiver operating characteristic (ROC) analysis to determine if 25OH-D levels are predictive of AMH showed areas under the ROC curves (AUCs) for women <38 years of age to be 0.501, 0.554, and 0.511 for AMH threshold values of 0.5 ng/mL, 1.0 ng/mL, and 5.0 ng/mL, respectively. For women >= 38 years respective AUC values were 0.549, 0.545, and 0.557 ng/mL. Conclusion(s): Vitamin D levels were not associated with ovarian reserve in a large group of infertile women with a high prevalence of diminished ovarian reserve. Previously reported vitamin D-associated outcomes in infertility patients may, therefore, be mediated by factors other than ovarian reserve. (C) 2018 by American Society for Reproductive Medicine.
Dunn AD, Reed B, Guariglia C, Dunn AM, Hillman JM, Kreek MJ
Show All Authors

Structurally Related Kappa Opioid Receptor Agonists with Substantial Differential Signaling Bias: Neuroendocrine and Behavioral Effects in C57BL6 Mice

INTERNATIONAL JOURNAL OF NEUROPSYCHOPHARMACOLOGY 2018 SEP; 21(9):847-857
Background: The kappa opioid receptor system has been revealed as a potential pharmacotherapeutic target for the treatment of addictions to substances of abuse. Kappa opioid receptor agonists have been shown to block the rewarding and dopamine-releasing effects of psychostimulants. Recent investigations have profiled the in vivo effects of compounds biased towards G-protein-mediated signaling, with less potent arrestin-mediated signaling. The compounds studied here derive from a series of trialkylamines: N-substituted-N- phenylethyl-N-3-hydroxyphenylethyl-amine, with N-substituents including n-butyl (BPHA), methylcyclobutyl (MCBPHA), and methylcyclopentyl (MCPPHA). Methods: BPHA, MCBPHA, and MCPPHA were characterized in vitro in a kappa opioid receptor-expressing cell line in binding assays and functional assays. We also tested the compounds in C57BL6 mice, assaying incoordination with rotarod, as well as circulating levels of the neuroendocrine kappa opioid receptor biomarker, prolactin. Results: BPHA, MCBPHA, and MCPPHA showed full kappa opioid receptor agonism for G-protein coupling compared with the reference compound U69,593. BPHA showed no measurable (3-arrestin-2 recruitment, indicating that it is extremely G-protein biased. MCBPHA and MCPPHA, however, showed submaximal efficacy for recruiting beta-arrestin-2. Studies in C57BL6 mice reveal that all compounds stimulate release of prolactin, consistent with dependence on G-protein signaling. MCBPHA and MCPPHA result in rotarod incoordination, whereas BPHA does not, consistent with the reported requirement of intact kappa opioid receptor/beta-arrestin-2 mediated coupling for kappa opioid receptor agonist-induced rotarod incoordination. Conclusions: BPHA, MCBPHA, and MCPPHA are thus novel differentially G-protein-biased kappa opioid receptor agonists. They can be used to investigate how signaling pathways mediate kappa opioid receptor effects in vitro and in vivo and to explore the effects of candidate kappa opioid receptor-targeted pharmacotherapeutics.
Maoileidigh DO, Hudspeth AJ
Show All Authors

Sinusoidal-signal detection by active, noisy oscillators on the brink of self-oscillation

PHYSICA D-NONLINEAR PHENOMENA 2018 SEP 1; 378(?):33-45
Determining the conditions under which an active system best detects sinusoidal signals is important for numerous fields. It is known that a quiescent, deterministic system possessing a supercritical Hopf bifurcation is more sensitive to sinusoidal stimuli the closer it operates to the bifurcation. To understand signal detection in many natural settings, however, noise must be taken into account. Herein we describe the detection of sinusoidal signals by noisy supercritical and subcritical Hopf oscillators. To distinguish an oscillator's motion owing to sinusoidal forcing from that provoked by noise, we employ the phase-locked amplitude and vector strength, which are zero in the absence of an external signal. The phase-locked amplitude and entrainment to frequency-detuned forcing - but not resonant forcing - peak as functions of the control parameter. These peaks occur near but not at the bifurcations. Moreover, an oscillator can detect stimuli over the broadest frequency range when it spontaneously oscillates near a Hopf bifurcation. Although noise exerts the greatest effect on the phase-locked amplitude when a Hopf oscillator is near a Hopf bifurcation, the oscillator nevertheless performs best as a sinusoidal-signal detector when it operates close to the bifurcation. The oscillator's ability to differentiate detuned signals from noise is greatest with it autonomously oscillates near to but not at the bifurcation. (C) 2018 Elsevier B.V. All rights reserved.