Menopause leads to elevated expression of macrophage-associated genes in the aging frontal cortex: rat and human studies identify strikingly similar changes.

BACKGROUND The intricate interactions between the immune, endocrine and central nervous systems shape the innate immune response of the brain. We have previously shown that estradiol suppresses expression of immune genes in the frontal cortex of middle-aged ovariectomized rats, but not in young ones reflecting elevated expression of these genes in middle-aged, ovarian hormone deficient animals. Here, we explored the impact of menopause on the microglia phenotype capitalizing on the differential expression of macrophage-associated genes in quiescent and activated microglia. METHODS We selected twenty-three genes encoding phagocytic and recognition receptors expressed primarily in microglia, and eleven proinflammatory genes and followed their expression in the rat frontal cortex by real-time PCR. We used young, middle-aged and middle-aged ovariectomized rats to reveal age- and ovariectomy-related alterations. We analyzed the expression of the same set of genes in the postcentral and superior frontal gyrus of pre- and postmenopausal women using raw microarray data from our previous study. RESULTS Ovariectomy caused up-regulation of four classic microglia reactivity marker genes including Cd11b, Cd18, Cd45 and Cd86. The change was reversible since estradiol attenuated transcriptional activation of the four marker genes. Expression of genes encoding phagocytic and toll-like receptors such as Cd11b, Cd18, C3, Cd32, Msr2 and Tlr4 increased, whereas scavenger receptor Cd36 decreased following ovariectomy. Ovarian hormone deprivation altered the expression of major components of estrogen and neuronal inhibitory signaling which are involved in the control of microglia reactivity. Strikingly similar changes took place in the postcentral and superior frontal gyrus of postmenopausal women. CONCLUSIONS Based on the overlapping results of rat and human studies we propose that the microglia phenotype shifts from the resting toward the reactive state which can be characterized by up-regulation of CD11b, CD14, CD18, CD45, CD74, CD86, TLR4, down-regulation of CD36 and unchanged CD40 expression. As a result of this shift, microglial cells have lower threshold for subsequent activation in the forebrain of postmenopausal women

Ghrelin Decreases Firing Activity of Gonadotropin-Releasing Hormone (GnRH) Neurons in an Estrous Cycle and Endocannabinoid Signaling Dependent Manner.

The orexigenic peptide, ghrelin is known to influence function of GnRH neurons, however, the direct effects of the hormone upon these neurons have not been explored, yet. The present study was undertaken to reveal expression of growth hormone secretagogue receptor (GHS-R) in GnRH neurons and elucidate the mechanisms of ghrelin actions upon them. Ca(2+)-imaging revealed a ghrelin-triggered increase of the Ca(2+)-content in GT1-7 neurons kept in a steroid-free medium, which was abolished by GHS-R-antagonist JMV2959 (10µM) suggesting direct action of ghrelin. Estradiol (1nM) eliminated the ghrelin-evoked rise of Ca(2+)-content, indicating the estradiol dependency of the process. Expression of GHS-R mRNA was then confirmed in GnRH-GFP neurons of transgenic mice by single cell RT-PCR. Firing rate and burst frequency of GnRH-GFP neurons were lower in metestrous than proestrous mice. Ghrelin (40nM-4μM) administration resulted in a decreased firing rate and burst frequency of GnRH neurons in metestrous, but not in proestrous mice. Ghrelin also decreased the firing rate of GnRH neurons in males. The ghrelin-evoked alterations of the firing parameters were prevented by JMV2959, supporting the receptor-specific actions of ghrelin on GnRH neurons. In metestrous mice, ghrelin decreased the frequency of GABAergic mPSCs in GnRH neurons. Effects of ghrelin were abolished by the cannabinoid receptor type-1 (CB1) antagonist AM251 (1µM) and the intracellularly applied DAG-lipase inhibitor THL (10µM), indicating the involvement of retrograde endocannabinoid signaling. These findings demonstrate that ghrelin exerts direct regulatory effects on GnRH neurons via GHS-R, and modulates the firing of GnRH neurons in an ovarian-cycle and endocannabinoid dependent manner

A fordítástudomány és a zenetudomány kapcsolatáról

A tanulmány szerzői a zene és fordítás, illetve a zenetudomány és fordítástudomány kapcsolatát kívánják felvázolni és példákkal is szemléltetni. Javaslatot tesznek a zenei fordítások problémakörének elhelyezésére a fordítástudományon belül, megemlítve a vonatkozó irodalmi, nyelvészeti és szövegtudományi kapcsolódási pontokat. Szó esik továbbá a különböző nyelvi közvetítési célok (szkoposz) elérését szolgáló eltérő fordítói döntésekről és stratégiákról. A vokális művek szövegfordításainak elemzésekor az énekelhetőség mint központi fogalom mellett – tekintettel a zenei fordítások készítőire, felhasználóira, befogadóira és kutatóira – további kulcsfontosságú tényezők (pl. felhasználási mód, befogadók előismeretei, a szöveg elhangzásának ténye és formája stb.) vizsgálata is indokolt lehet. A tanulmány szakirodalmi áttekintése egymásra is reflektáló, olykor pedig akár vitában is álló kutatási nézőpontok és eredmények összefoglalásán túl kiemelt figyelmet fordít a dalok és operák fordítási kérdéseivel foglalkozó tudományos publikációk ismertetésére. E két vokális műfaj különlegesen népszerűnek bizonyul a fordítástudományi kutatásokban, ráadásul formai és terjedelmi szempontból végleteket is képviselnek a hangszerkíséretes énekelt művek kategóriáján belül, ennek köszönhetően pedig a zenei fordítások általános jellemzőin túl a műfajhoz kötött fordítási tulajdonságok és szempontok bemutatására is alkalmasnak bizonyulnak. A szerzők szándéka szerint a tanulmány megállapításai a zenei fordítások iránt érdeklődőknek és a témával foglalkozó szakembereknek is új ismeretekkel és kutatási ötletekkel szolgálhatnak

Ovariectomy Alters Gene Expression of the Hippocampal Formation in Middle-Aged Rats

Ovarian hormones regulate the transcriptome of the hippocampus and modulate its functions. During 29 menopause, this complex signaling declines, leading to impaired learning and memory. This study was 30 undertaken to clarify the effects of long-term, surgical ovariectomy (OVX) on the rat hippocampal 31 transcriptome. At age of 13 months, intact control and ovariectomized groups were formed. All animals 32 were sacrificed 5 weeks after gonadectomy, hippocampal formations were dissected and processed for 33 transcriptome analysis. Microarray and PCR studies identified 252 and 61 genes, respectively, whose 34 expression was altered in the lack of ovarian hormones. Pathway analysis revealed impact on 35 neuroactive ligand-receptor interaction, endocannabinoid and estrogen signaling, among others. 36 Network and interaction analyses of proteins encoded by OVX-regulated genes revealed upregulation 37 of growth/ troph/transcription factor signaling assembly (Mdk, Fgf1, Igf2, Ngf, Ngfr, Ntf3, Ntrk1, Otx2, 38 Hif1a, Esr1, Nr4a3), peptides/peptide receptors (Cartp, Kl, Ttr, Gnrhr), neurotransmission (Grm1, 39 Gria4, Gls, Slc18a2, Kcj6) and genes serving immune functions (C3, Ccl2, Itgam, Il1b). Downregulated 40 clusters included neuropeptides and their receptors (Adcyap1, Cbln2, Cck, Cckbr, Crhr1 and 2, Oprd1, 41 Nts, Penk, Sstr1, Vip), neurotransmitter signaling (Htr2c, hrna3, Chrm4, Grm8, Hrh3, Slc17a6) and 42 potassium channels (Kcnk9, Kcnj9, Kcnma1, Kcnc2). Several transcription factors (Rxra, Thrb), solute 43 carriers and defense molecules (Apitd1, Bcl2, Clql3, Ilr3a, Sod1, Sncb) also underwent downregulation. 44 The findings indicate that surgical gonadectomy carried out at middle-age robustly changes the 45 hippocampal transcriptome that alters neurogenesis, synaptic plasticity, immune modulation causing 46 cognitive dysfunctions

Ovariectomy and Subsequent Treatment with Estrogen Receptor Agonists Tune the Innate Immune System of the Hippocampus in Middle-Aged Female Rats

The innate immune system including microglia has a major contribution to maintenance of the physiological functions of the hippocampus by permanent monitoring of the neural milieu and elimination of tissue-damaging threats. The hippocampus is vulnerable to age-related changes ranging from gene expression to network connectivity. The risk of hippocampal deterioration increases with the decline of gonadal hormone supply. To explore the impact of hormone milieu on the function of the innate immune system in middle-aged female rats, we compared mRNA expression in the hippocampus after gonadal hormone withdrawal, with or without subsequent estrogen replacement using estradiol and isotype-selective estrogen receptor (ER) agonists. Targeted profiling assessed the status of the innate immune system (macrophage-associated receptors, complement, inhibitory neuronal ligands), local estradiol synthesis (P450 aromatase) and estrogen reception (ER). Results established upregulation of macrophage-associated (Cd45, Iba1, Cd68, Cd11b, Cd18, Fcgr1a, Fcgr2b) and complement (C3, factor B, properdin) genes in response to ovariectomy. Ovariectomy upregulated Cd22 and downregulated semaphorin3A (Sema3a) expression, indicating altered neuronal regulation of microglia. Ovariectomy also led to downregulation of aromatase and upregulation of ERa gene. Of note, analogous changes were observed in the hippocampus of postmenopausal women. In ovariectomized rats, estradiol replacement attenuated Iba1, Cd11b, Fcgr1a, C3, increased mannose receptor Mrc1, Cd163 and reversed Sema3a expression. In contrast, reduced expression of aromatase was not reversed by estradiol. While the effects of ERa agonist closely resembled those of estradiol, ERb agonist was also capable of attenuating the expression of several macrophage-associated and complement genes. These data together indicate that the innate immune system of the aging hippocampus is highly responsive to the gonadal hormone milieu. In ovariectomized female rats, estradiol replacement exerts potent immunomodulatory effects including attenuation of microglia sensitization, initiation of M2-like activation and modulation of complement expression by targeting hippocampal neurons and glial cells through ERa and ERb

Differential Gene Expression in Gonadotropin-Releasing Hormone Neurons of Male and Metestrous Female Mice.

BACKGROUND: Gonadotropin-releasing hormone (GnRH) neurons play a pivotal role in regulation of the hypothalamic-pituitary gonadal axis in a sex-specific manner. We hypothesized that the differences seen in reproductive functions of males and females are associated with a sexually dimorphic gene expression profile of GnRH neurons. METHODS AND RESULTS: We compared the transcriptome of GnRH neurons obtained from intact, metestrous female and male GnRH-GFP transgenic mice. About 1,500 individual GnRH neurons from each sex were sampled with laser capture microdissection followed by whole transcriptome amplification for gene expression profiling. Under stringent selection criteria (fold change >1.6, adjusted p value 0.01), Affymetrix Mouse Genome 430 PM array analysis identified 543 differentially expressed genes. Sexual dimorphism was most apparent in gene clusters associated with synaptic communication, signal transduction, cell adhesion, vesicular transport and cell metabolism. To validate microarray results, 57 genes were selected and 91% of their differential expression was confirmed by real-time PCR. Similarly, 88% of microarray results were confirmed with PCR from independent samples obtained by patch pipette harvesting and pooling of 30 GnRH neurons from each sex. We found significant differences in expression of genes involved in vesicle priming and docking (Syt1, Cplx1), GABAergic (Gabra3, Gabrb3, Gabrg2) and glutamatergic (Gria1, Grin1, Slc17a6) neurotransmission, peptide signaling (Sstr3, Npr2, Cxcr4) and the regulation of intracellular ion homeostasis (Cacna1, Cacnb1, Cacng5, Kcnq2, Kcnc1). CONCLUSION: The striking sexual dimorphism of the GnRH neuron transcriptome we report here contributes to the better understanding the differences in cellular mechanisms of GnRH neurons in the two sexes. (c) 2015 S. Karger AG, Basel

Estrogen receptor alpha and beta differentially mediate C5aR agonist evoked Ca2+-influx in neurons through L-type voltage-gated Ca2+ channels

Complement C5a is associated primarily with inflammation. The widespread expression of its receptors, C5aR and C5L2 in neuronal cells, however, suggests additional regulatory roles for C5a in the CNS. C5aR agonist (PL37-MAP) evokes Ca2+-influx in GT1-7 neuronal cell line and the Ca2+-influx is regulated by estradiol. In the present study, we examined further the mechanism of Ca2+-influx and the contribution of the two estrogen receptor (ER) isotypes, ERα and ERβ, to estrogenic modulation of intracellular Ca2+-content. GT1-7 neurons were treated with isotype selective ER agonists for 24 h then C5aR agonist evoked Ca2+-responses were measured by Ca2+-imaging. Transcriptional changes were followed by real-time PCR. We found that not only estradiol (100 pM), but the ERα selective agonist PPT (100 pM) enhanced the PL37-MAP-evoked Ca2+-influx (E2: 215%, PPT: 175%, compared to the PL37-MAP-evoked Ca2+-influx). In contrast, the ERβ selective agonist DPN (100 pM) significantly reduced the Ca2+-influx (32%). Attenuated Ca2+-response (25%) was observed in Ca-free environment and depletion of the Ca2+-pool by CPA eliminated the remaining elevation in the Ca2+-content, demonstrating that the majority of Ca2+ originated from the extracellular compartment. L-type voltage-gated Ca2+-channel (L-VGCC) blocker nifedipine abolished the Ca2+-influx, while R-type Ca2+-channel blocker SNX-482 had no effect, exemplifying the predominant role of L-VGCC in this process. Acute pre-treatments (8 min) with ER agonists did not affect the evoked Ca2+-influx, revealing that the observed effects of estrogens were genomic. Therefore, we checked estrogenic regulation of C5a receptors and L-VGCC subunits. ER agonists increased C5aR mRNA expression, whereas they differentially regulated C5L2. Estradiol decreased transcription of Cav1.3 L-VGCC subunit. Based on these results we propose that estradiol may differentially modulate C5a-induced Ca2+-influx via L-VGCCs in neurons depending on the expression of the two ER isotypes

Altered Gene Expression Profile of the Hypothalamic Arcuate Nucleus of Male Mice Suggests Profound Developmental Changes in Peptidergic Signaling

Neuropeptides of the hypothalamic arcuate nucleus (ARC) regulate important homeostatic and endocrine functions and also play critical roles in pubertal development. Altered peptidergic and amino acidergic neurotransmission accompanying pubertal maturation of the ARC are not fully understood. Here we studied the developmental shift in the gene expression profile of the ARC of male mice. RNA samples for quantitative RT-PCR studies were isolated from the ARC of day-14 infantile and day-60 adult male mice with laser-capture microdissection. The expression of 18 neuropeptide-, 15 neuropeptide receptor-, 4 sex steroid receptor and 6 classic neurotransmitter marker mRNAs were compared between the two timepoints. Adult animals showed increased mRNA levels encoding cocaine- and amphetamine-regulated transcript, galanin-like peptide, dynorphin, kisspeptin, proopiomelanocortin, proenkephalin and galanin and reduced expression of mRNAs for pituitary adenylate cyclase activating peptide, calcitonin gene-related peptide, neuropeptide Y, substance P, agouti-related protein, neurotensin and growth hormone-releasing hormone. From the neuropeptide receptors tested, melanocortin receptor-4 showed the most striking (5-fold) increase. Melanocortin receptor-3 and the Y1 and Y5 neuropeptide Y receptors increased 1.5-1.8-fold, whereas delta-opioid receptor and neurotensin receptor-1 transcripts were reduced by 27 and 21%, respectively. Androgen-, progesterone- and alpha-estrogen receptor transcripts increased by 54-72%. The mRNAs of glutamic acid decarboxylase 65, and 67, vesicular GABA transporter and choline acetyltransferase remained unchanged. Tyrosine hydroxylase mRNA increased by 44%, whereas type-2 vesicular glutamate transporter mRNA decreased by 43% by adulthood. Many of the developmental changes we revealed in this study suggest reduced inhibitory and/or enhanced excitatory neuropeptidergic drive on fertility in adult animals. (c) 2015 S. Karger AG, Basel

Hippocampal Gene Expression Is Highly Responsive to Estradiol Replacement in Middle-Aged Female Rats.

In the hippocampus, estrogens are powerful modulators of neurotransmission, synaptic plasticity and neurogenesis. In women, menopause is associated with increased risk of memory disturbances, which can be attenuated by timely estrogen therapy. In animal models of menopause, 17beta-estradiol (E2) replacement improves hippocampus-dependent spatial memory. Here, we explored the effect of E2 replacement on hippocampal gene expression in a rat menopause model. Middle-aged ovariectomized female rats were treated continuously for 29 days with E2 and then, the hippocampal transcriptome was investigated with Affymetrix expression arrays. Microarray data were analyzed by Bioconductor packages and web-based softwares, and verified with quantitative PCR. At standard fold change (FC) selection criterion, 156 genes responded to E2. All alterations but four were transcriptional activation. Robust activation (FC>10) occurred in the case of transthyretin, klotho, claudin 2, prolactin receptor, ectodin, coagulation factor V, insulin-like growth factor 2, Igfbp2 and sodium/sulfate symporter. Classification of the 156 genes revealed major groups including signaling (35 genes), metabolism (31 genes), extracellular matrix (17 genes) and transcription (16 genes). We selected 33 genes for further studies and all changes were confirmed by real-time PCR. The results suggest that E2 promotes retinoid, growth factor, homeoprotein, neurohormone and neurotransmitter signaling, changes metabolism, extracellular matrix composition, transcription, and induce protective mechanisms via genomic effects. We propose that these mechanisms contribute to effects of E2 on neurogenesis, neural plasticity and memory functions. Our findings provide further support for the rationale to develop safe estrogen receptor ligands for the maintenance of cognitive performance in postmenopausal women

Estrogens regulate neuroinflammatory genes via estrogen receptors α and β in the frontal cortex of middle-aged female rats

ABSTRACT: BACKGROUND: Estrogens exert anti-inflammatory and neuroprotective effects in the brain mainly via estrogen receptors alpha (ERalpha) and beta (ERbeta). These receptors are members of the nuclear receptor superfamily of ligand-dependent transcription factors. This study was aimed at the elucidation of the effects of ERalpha and ERbeta agonists on the expression of neuroinflammatory genes in the frontal cortex of aging female rats. METHODS: To identify estrogen-responsive immunity/inflammation genes, we treated middle-aged, ovariectomized rats with 17beta-estradiol (E2), ERalpha agonist 16alpha-lactone-estradiol (16alpha-LE2) and ERbeta agonist diarylpropionitrile (DPN), or vehicle by Alzet minipump delivery for 29 days. Then we compared the transcriptomes of the frontal cortex of estrogen-deprived versus ER agonist-treated animals using Affymetrix Rat230 2.0 expression arrays and TaqMan-based quantitative real-time PCR. Microarray and PCR data were evaluated by using Bioconductor packages and the RealTime StatMiner software, respectively. RESULTS: Microarray analysis revealed the transcriptional regulation of 21 immunity/inflammation genes by 16alpha-LE2. The subsequent comparative real-time PCR study analyzed the isotype specific effects of ER agonists on neuroinflammatory genes of primarily glial origin. E2 regulated the expression of sixteen genes, including down-regulation of complement C3 and C4b, Ccl2, Tgfb1, macrophage expressed gene Mpeg1, RT1-Aw2, Cx3cr1, Fcgr2b, Cd11b, Tlr4 and Tlr9, and up-regulation of defensin Np4 and RatNP-3b, IgG-2a, Il6 and ER gene Esr1. Similar to E2, both 16alpha-LE2 and DPN evoked up-regulation of defensins, IgG-2a and Il6, and down-regulation of C3 and its receptor Cd11b, Ccl2, RT1-Aw2 and Fcgr2b. CONCLUSIONS: These findings provide evidence that E2, 16alpha-LE2 and DPN modulate the expression of neuroinflammatory genes in the frontal cortex of middle-aged female rats via both ERalpha and ERbeta. We propose that ERbeta is a promising target to suppress regulatory functions of glial cells in the E2-deprived female brain and in various neuroinflammatory diseases