PROGESTIN BINDING IN VITRO BY THE BRAIN CELL NUCLEI OF OVARIECTOMIZED OESTROGEN-PRIMED RATS

1979 ◽  
Vol 82 (3) ◽  
pp. 347-NP ◽  
Author(s):  
K. SEIKI ◽  
Y. HARUKI ◽  
Y. IMANISHI ◽  
T. ENOMOTO
Keyword(s):  
Cerebral Cortex ◽  
Sucrose Density Gradient ◽  
Brain Cell ◽  
Nuclear Fraction ◽  
Cell Nuclei ◽  
Medial Basal Hypothalamus ◽  
Similar Preparation ◽  
The Brain ◽  
Binding Component

The uptake and binding of 17α,21-dimethyl-19-nor-4,9-pregnadiene-3,20-dione, a synthetic progestin, by the hypothalamus and cerebral cortex of ovariectomized oestrogen-primed rats was examined in vitro. Uptake of this steroid by the medial basal hypothalamus was higher than that by the remaining hypothalamus and cerebral cortex. The component in the cytosol from whole hypothalami which bound the radioactive progestin sedimented in the 7S region when centrifuged in a sucrose density gradient. The tritiated progestin was displaced by incubation with non-radioactive progestin or progesterone but not by oestradiol-17β, corticosterone or 5α-dihydrotestosterone (1 μmol/l). No 7S binding component was detected in a similar preparation from the cerebral cortex. The nuclear fraction from whole hypothalami extracted by KCl (0·4 mol/l) contained a progestin-binding complex which sedimented at 9S and which was heat-labile and protein in nature. It was concluded that the hypothalamus of ovariectomized oestrogen-primed rats contains progestin-binding material in the cytoplasm and progestin, bound to such material, is transported from the cytoplasm to the nucleus.

scholarly journals Localization of non-conventional protein kinase C isoforms in bovine brain cell nuclei

1995 ◽  
Vol 305 (1) ◽  
pp. 269-275 ◽  
Author(s):  
U Rosenberger ◽  
M Shakibaei ◽  
K Buchner
Keyword(s):  
Cerebral Cortex ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Nuclear Envelope ◽  
Immunofluorescence Microscopy ◽  
Brain Cell ◽  
Bovine Brain ◽  
Cell Nuclei ◽  
Kinase C ◽  
Protein Kinase C Isoforms

Using Western blotting and immunofluorescence microscopy we detected the protein kinase C isoforms delta, epsilon and zeta in isolated cell nuclei from bovine cerebral cortex. Both protein kinase C (PKC) delta and PKC epsilon are present in higher concentrations in neuronal than in glial nuclei and are located inside the nucleus and at the nuclear envelope. There they give a punctate staining in immunofluorescence microscopy. PKC zeta is also present both in the nucleoplasm and at the nuclear envelope. PKC eta could not be detected in the cell nuclei and, even in the homogenate of cerebral cortex, this isoform is present only in very low concentrations. The antibody against PKC eta bound strongly to a nucleoplasmic protein with an apparent molecular mass of 99 kDa. The localization of non-conventional PKC isoforms at the cell nucleus strongly indicates that these isoforms are directly involved in the regulation of nuclear processes.

Syzygium cumini (L.) skeels seed extract ameliorates in vitro and in vivo oxidative potentials of the brain cerebral cortex of alcohol-treated rats

2011 ◽  
Vol 12 (1) ◽  
pp. 59-66 ◽  
Author(s):  
Shahdat Hossain ◽  
Asiqur Rahaman ◽  
Taslima Nahar ◽  
Mafroz Ahmed Basunia ◽  
Ferdousi Rahman Mowsumi ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
Seed Extract ◽  
Syzygium Cumini ◽  
The Brain

BINDING OF 3H-OESTRADIOL WITH RECEPTORS IN THE HUMAN ENDOMETRIUM AND MYOMETRIUM

1973 ◽  
Vol 74 (4) ◽  
pp. 756-768 ◽  
Author(s):  
A. R. Krishnan ◽  
V. Hingorani ◽  
K. R. Laumas
Keyword(s):  
Sedimentation Coefficient ◽  
Sucrose Density Gradient ◽  
Human Endometrium ◽  
Gel Chromatography ◽  
Nuclear Fraction ◽  
Ligand Specificity ◽  
Human Uterus ◽  
Specific Proteins

ABSTRACT The in vivo and in vitro binding of 3H-oestradiol-17β to cytoplasmic and nuclear fractions of the human endometrium and myometrium was demonstrated by different techniques. Sucrose density gradient ultracentrifugation of the endometrial cytoplasm showed that oestradiol binds with two specific proteins sedimenting at 8.5 S and 5.1 S. Myometrial cytoplasmic oestrogen binding protein (OeBP) had a sedimentation coefficient of 5.1 S. Nuclear OeBP in the endometrium and myometrium had the same sedimentation value of 4.2 S. The endometrial cytoplasmic OeBP separated by gel chromatography showed association with both oestradiol and oestrone in the ratio of 2:1. The OeBP in nuclear fraction of the endometrium and myometrium showed binding with oestradiol and oestrone in the ratio of 2.5:1 and 2:1 respectively. The association of oestrone along with oestradiol with receptors of the endometrial and myometrial nuclear and cytoplasmic fractions suggests that oestrone may play a significant role in the overall action of oestrogens in the human uterus. Studies on ligand specificity of the OeBPs showed that oestrone which is a comparatively weaker oestrogen, competitively displaced bound 3H-oestradiol, more or less in a similar way as a highly potent oestrogen diethylstilboestrol (DOeS). Chlormadinone acetate (CAP), among the progestational steroids tested, maximally displaced bound oestradiol. The significance of these findings in the mechanism of action of oestradiol in the human uterus is discussed.

scholarly journals Subcellular localization of transglutaminase. Effect of collagen

1988 ◽  
Vol 250 (2) ◽  
pp. 421-427 ◽  
Author(s):  
M Juprelle-Soret ◽  
S Wattiaux-De Coninck ◽  
R Wattiaux
Keyword(s):  
Plasma Membrane ◽  
Rat Liver ◽  
Plasma Membranes ◽  
Sucrose Density Gradient ◽  
Collagen Type I ◽  
Type I ◽  
Nuclear Fraction ◽  
Binding Studies ◽  
Isopycnic Centrifugation

1. The subcellular distribution of transglutaminase was investigated by using the analytical approach of differential and isopycnic centrifugation as applied to three organs of the rat: liver, kidney and lung. After differential centrifugation by the method of de Duve, Pressman, Gianetto, Wattiaux & Appelmans [(1955) Biochem. J. 63, 604-617], transglutaminase is mostly recovered in the unsedimentable fraction S and the nuclear fraction N. After isopycnic centrifugation of the N fraction in a sucrose density gradient, a high proportion of the enzyme remains at the top of the gradient; a second but minor peak of activity is present in high-density regions, where a small proportion of 5′-nucleotidase, a plasma-membrane marker, is present together with a large proportion of collagen recovered in that fraction. 2. Fractions where a peak of transglutaminase was apparent in the sucrose gradient were examined by electron microscopy. The main components are large membrane sheets with extracellular matrix and free collagen fibers. 3. As these results seem to indicate that some correlation exists between particulate transglutaminase distribution and those of collagen and plasma membranes, the possible binding of transglutaminase by collagen (type I) and by purified rat liver plasma membrane was investigated. 4. The binding studies indicated that collagen is able to bind transglutaminase and to make complexes with plasma-membrane fragments whose density is higher than that of plasma-membrane fragments alone. Transglutaminase cannot be removed from such complexes by 1% Triton X-100, but can be to a relatively large extent by 0.5 M-KCl and by 50% (w/v) glycerol. 5. Such results suggest that the apparent association of transglutaminase with plasma membrane originates from binding in vitro of the cytosolic enzyme to plasma membrane bound to collagen, which takes place during homogenization of the tissue, when the soluble enzyme and extracellular components are brought together.

scholarly journals Listeria monocytogenes Spreads within the Brain by Actin-Based Intra-Axonal Migration

2015 ◽  
Vol 83 (6) ◽  
pp. 2409-2419 ◽  
Author(s):  
Diana Henke ◽  
Sebastian Rupp ◽  
Véronique Gaschen ◽  
Michael H. Stoffel ◽  
Joachim Frey ◽  
...  
Keyword(s):  
Immune Response ◽  
Listeria Monocytogenes ◽  
Brain Cell ◽  
Bovine Brain ◽  
Content Type ◽  
Bacterial Migration ◽  
Bacterial Replication ◽  
The Brain

Listeria monocytogenesrhombencephalitis is a severe progressive disease despite a swift intrathecal immune response. Based on previous observations, we hypothesized that the disease progresses by intra-axonal spread within the central nervous system. To test this hypothesis, neuroanatomical mapping of lesions, immunofluorescence analysis, and electron microscopy were performed on brains of ruminants with naturally occurring rhombencephalitis. In addition, infection assays were performed in bovine brain cell cultures. Mapping of lesions revealed a consistent pattern with a preferential affection of certain nuclear areas and white matter tracts, indicating thatListeria monocytogenesspreads intra-axonally within the brain along interneuronal connections. These results were supported by immunofluorescence and ultrastructural data localizingListeria monocytogenesinside axons and dendrites associated with networks of fibrillary structures consistent with actin tails.In vitroinfection assays confirmed that bacteria were moving within axon-like processes by employing their actin tail machinery. Remarkably,in vivo, neutrophils invaded the axonal space and the axon itself, apparently by moving between split myelin lamellae of intact myelin sheaths. This intra-axonal invasion of neutrophils was associated with various stages of axonal degeneration and bacterial phagocytosis. Paradoxically, the ensuing adaxonal microabscesses appeared to provide new bacterial replication sites, thus supporting further bacterial spread. In conclusion, intra-axonal bacterial migration and possibly also the innate immune response play an important role in the intracerebral spread of the agent and hence the progression of listeric rhombencephalitis.

scholarly journals Primary brain cell infection by Toxoplasma gondii reveals the extent and dynamics of parasite differentiation and its impact on neuron biology

Open Biology ◽  
2021 ◽  
Vol 11 (10) ◽  
Author(s):  
Thomas Mouveaux ◽  
Emmanuel Roger ◽  
Alioune Gueye ◽  
Fanny Eysert ◽  
Ludovic Huot ◽  
...  
Keyword(s):  
Toxoplasma Gondii ◽  
Brain Cell ◽  
Parasite Infection ◽  
Brain Cells ◽  
Specific Response ◽  
Rna Seq ◽  
Cell Infection ◽  
The Brain

Toxoplasma gondii is a eukaryotic parasite that forms latent cysts in the brain of immunocompetent individuals. The latent parasite infection of the immune-privileged central nervous system is linked to most complications. With no drug currently available to eliminate the latent cysts in the brain of infected hosts, the consequences of neurons' long-term infection are unknown. It has long been known that T. gondii specifically differentiates into a latent form (bradyzoite) in neurons, but how the infected neuron responds to the infection remains to be elucidated. We have established a new in vitro model resulting in the production of mature bradyzoite cysts in brain cells. Using dual, host and parasite RNA-seq, we characterized the dynamics of differentiation of the parasite, revealing the involvement of key pathways in this process. Moreover, we identified how the infected brain cells responded to the parasite infection revealing the drastic changes that take place. We showed that neuronal-specific pathways are strongly affected, with synapse signalling being particularly affected, especially glutamatergic synapse signalling. The establishment of this new in vitro model allows investigating both the dynamics of parasite differentiation and the specific response of neurons to long-term infection by this parasite.

VI. EFFECTS OF THE ANTI-ANDROGEN TSAA-291 AND ITS RELATED COMPOUNDS ON THE IN VITRO FORMATION OF 5α-DHT-RECEPTOR COMPLEX IN THE CYTOSOL OF RAT VENTRAL PROSTATES

1979 ◽  
Vol 92 (3_Supplb) ◽  
pp. S82-S99 ◽  
Author(s):  
Katsuichiro Sudo ◽  
Keiji Yoshida ◽  
Ryo Nakayama
Keyword(s):  
Gradient Centrifugation ◽  
Sucrose Density Gradient ◽  
Inhibitory Effect ◽  
Receptor Complex ◽  
Sucrose Density Gradient Centrifugation ◽  
Androgenic Activity ◽  
Derivatives Of ◽  
Related Compounds ◽  
Binding Component

ABSTRACT Inhibitory effect of a synthetic steroidal anti-androgen TSAA-291 (16β-ethyl-17β-hydroxy-4-oestren-3-one) on the in vitro formation of 5α-dihydrotestosterone(5α-DHT)-receptor complex was examined. An aliquot of the cytosol from rat ventral prostates was incubated with [3H]5α-DHT in the presence of various amounts of the anti-androgen. By means of dextran-coated charcoal assay and sucrose density-gradient centrifugation analysis, TSAA-291 was demonstrated to inhibit directly, in a competitive manner, the binding of 5α-DHT to a component analogous in its properties to the cytosol androgen receptor. Further, displacing study using a variety of TSAA-291 analogues was undertaken to examine which of the functional groups of TSAA-291 is important for the affinity to the 5α-DHT binding component, and elucidated that 3-hydroxy or 5α-dihydro derivatives of TSAA-291 and others having axial methyl group at C-10 were less potent competitors for [3H]5α-DHT binding than TSAA-291. Furthermore, using other steroids including androgens and anti-androgens, considerable knowledge was obtained about structural requirements for a steroid molecule to displace the bound [3H] 5α-DHT, and this displacing activity of the steroids was discussed in terms of their anti-androgenic activity.

LOCALIZATION OF OESTRADIOL RECEPTORS IN THE RAT HYPOTHALAMUS

1973 ◽  
Vol 72 (4) ◽  
pp. 663-670 ◽  
Author(s):  
Junzo Kato
Keyword(s):  
Median Eminence ◽  
Density Gradient Centrifugation ◽  
Gradient Centrifugation ◽  
Sucrose Density Gradient ◽  
Ovariectomized Rats ◽  
Female Rat ◽  
Sucrose Density Gradient Centrifugation ◽  
Hypothalamic Region ◽  
The Brain

ABSTRACT An attempt was made to isolate oestradiol receptors by sucrose density gradient centrifugation from hypothalamic cytoplasm labelled in vitro with 3H-oestradiol obtained from adult ovariectomized rats, in order to elucidate the site of the feedback action of oestrogen on the brain. The oestradiol receptors are predominantly localized in the preoptic-anterior hypothalamic region and the median eminence, although the receptors are distributed widely in different concentrations in the female rat brain. Oestrogen may act on the brain through the interaction of the hormone with the oestradiol receptors in the preoptic-anterior hypothalamic region and in the median eminence.

scholarly journals Modulation of intercolumnar synchronization by endogenous electric fields in cerebral cortex

2021 ◽  
Vol 7 (10) ◽  
pp. eabc7772
Author(s):  
Beatriz Rebollo ◽  
Bartosz Telenczuk ◽  
Alvaro Navarro-Guzman ◽  
Alain Destexhe ◽  
Maria V. Sanchez-Vives
Keyword(s):  
Cerebral Cortex ◽  
Electric Fields ◽  
Rhythmic Activity ◽  
Cortical Columns ◽  
Mediated Effects ◽  
Cortical Oscillations ◽  
Dipole Interactions ◽  
Electric Dipoles ◽  
The Brain

Neurons synaptically interacting in a conductive medium generate extracellular endogenous electric fields (EFs) that reciprocally affect membrane potential. Exogenous EFs modulate neuronal activity, and their clinical applications are being profusely explored. However, whether endogenous EFs contribute to network synchronization remains unclear. We analyzed spontaneously generated slow-wave activity in the cerebral cortex network in vitro, which allowed us to distinguish synaptic from nonsynaptic mechanisms of activity propagation and synchronization. Slow oscillations generated EFs that propagated independently of synaptic transmission. We demonstrate that cortical oscillations modulate spontaneous rhythmic activity of neighboring synaptically disconnected cortical columns if layers are aligned. We provide experimental evidence that these EF-mediated effects are compatible with electric dipoles. With a model of interacting dipoles, we reproduce the experimental measurements and predict that endogenous EF–mediated synchronizing effects should be relevant in the brain. Thus, experiments and models suggest that electric-dipole interactions contribute to synchronization of neighboring cortical columns.

Invited Review: Estrogens effects on the brain: multiple sites and molecular mechanisms

2001 ◽  
Vol 91 (6) ◽  
pp. 2785-2801 ◽  
Author(s):  
Bruce S. McEwen
Keyword(s):  
Estrogen Receptors ◽  
Molecular Mechanisms ◽  
Nerve Cells ◽  
Fine Motor ◽  
Aging Brain ◽  
Cell Nuclei ◽  
Neuroprotective Effects ◽  
Pain Mechanisms ◽  
The Brain

Besides their well-established actions on reproductive functions, estrogens exert a variety of actions on many regions of the nervous system that influence higher cognitive function, pain mechanisms, fine motor skills, mood, and susceptibility to seizures; they also appear to have neuroprotective actions in relation to stroke damage and Alzheimer's disease. Estrogen actions are now recognized to occur via two different intracellular estrogen receptors, ER-α and ER-β, that reside in the cell nuclei of some nerve cells, as well as by some less well-characterized mechanisms. In the hippocampus, such nerve cells are sparse in number and yet appear to exert a powerful influence on synapse formation by neurons that do not have high levels of nuclear estrogen receptors. However, we also find nonnuclear estrogen receptors outside of the cell nuclei in dendrites, presynaptic terminals, and glial cells, where estrogen receptors may couple to second messenger systems to regulate a variety of cellular events and signal to the nuclear via transcriptional regulators such as CREB. Sex differences exist in many of the actions of estrogens in the brain, and the process of sexual differentiation appears to affect many brain regions outside of the traditional brain areas involved in reproductive functions. Finally, the aging brain is responsive to actions of estrogens, which have neuroprotective effects both in vivo and in vitro. However, in an animal model, the actions of estrogens on the hippocampus appear to be somewhat attenuated with age. In the future, estrogen actions over puberty and in pregnancy and lactation should be further explored and should be studied in both the hypothalamus and the extrahypothalamic regions.

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