Phylogeny and Ontogeny of Chemical Signaling: Origin and Development of Hormone Receptors

circRNA432 enhances the coelomocyte phagocytosis via regulating the miR-2008-ELMO1 axis in Vibrio splendidus-challenged Apostichopus japonicus

Circular RNAs (circRNAs) are a kind of extensive and diverse covalently closed circular endogenous RNA, which exert crucial functions in immune regulation in mammals. However, the functions and mechanisms of circRNAs in invertebrates are largely unclarified. In our previous work, 261 differentially expressed circRNAs including circRNA432 (circ432) were identified from skin ulcer syndrome (SUS) diseased sea cucumber Apostichopus japonicus by RNA-seq. To better address the functional role of sea cucumber circRNAs, circ432 was first found to be significantly induced by Vibrio splendidus challenge and LPS exposure in this study. Knock-down circ432 could depress the V. splendidus-induced coelomocytes phagocytosis. Moreover, circ432 is validated to serve as the sponge of miR-2008, a differential expressed miRNA in SUS-diseased sea cucumbers, by Argonaute 2-RNA immunoprecipitation (AGO2-RIP) assay, luciferase reporter assay and RNA fluorescence in situ hybridization (FISH) in vitro. Engulfment and cell motility protein 1 (AjELMO1) is further demonstrated to be the target of miR-2008, and silencing AjELMO1 inhibits the V. splendidus-induced coelomocytes phagocytosis, and this phenomenon could be further suppressed by supplementing with miR-2008 mimics, suggesting that circ432 might regulate coelomocytes phagocytosis via miR-2008-AjELMO1 axis. We further confirm that the depressed coelomocytes' phagocytosis by circ432 silencing is consistent with the decreased abundance of AjELMO1, and could be recovered by miR-2008 inhibitors transfection. All our results provide the evidence that circ432 is involved in regulating pathogen-induced coelomocyte phagocytosis via sponge miR-2008 and promotes the abundance of AjELMO1. These findings will enrich the regulatory mechanism of phagocytosis in echinoderm and provide theoretical data for SUS disease prevention and control in sea cucumbers.

Ultra low doses and biological amplification: Approaching Avogadro's number

This paper describes evidence establishing that ultra-low doses of diverse chemical agents at concentrations from 10^-18 to 10^-24 M (e.g., approaching and/or less than 1 atom or molecule of a substance/cell based on Avogadro's constant - 6.022×10²³/mole) are capable of engaging receptor and intracellular signaling systems to elicit reproducible effects in a variety of species, from unicellular organisms to humans. Multiple experimental studies have shown that only one or very few molecules are needed to activate a cell and/or entire organism via cascade(s) of amplification mechanisms and processes. For example, ultra-low dose ligand exposure was able to activate both an individual cell, and ~3000 to 25,000 neighboring cells on average, by about 50%. Such activation of cells and whole organisms typically displayed hormetic-biphasic dose responses. These findings indicate that numerous, diverse phylogenetic systems have evolved highly sensitive detection and signaling mechanisms to enhance survival functions, such as defense against infectious agents, responses to diverse types of pheromone communications (e.g., alarm, sexual attraction), and development of several types of cellular protection/resilience processes. This suggests that ultra-low dose effects may be far more common than have been recognized to date. We posit that such findings have important implications for evolutionary theory, ecological and systems biology, and clinical medicine.

Vitamin-caused faulty perinatal hormonal imprinting and its consequences in adult age

Lipid-soluble vitamins (vitamins A, D, E, and K) are actually hormones (exohormones), as they can be directly bound by hormone receptors or are in connection with molecules, which influence hormone receptors. Vitamin D is a transition between endo- and exohormones and the possibility of similar situation in case of other lipid-soluble hormones is discussed. The perinatal exposition with these “vitamins” can cause faulty perinatal hormonal imprinting with similar consequences as the faulty imprinting by the synthetic endohormones, members of the same hormone family or industrial, communal, or medical endocrine disruptors. The faulty imprinting leads to late (lifelong) consequences with altered hormone binding by receptors, altered sexuality, brain function, immunity, bone development, and fractures, etc. In addition, as hormonal imprinting is an epigenetic process, the effect of a single exposure by fat-soluble vitamins is inherited to the progeny generations. As vitamins are handled differently from hormones; however, perinatal treatments take place frequently and sometimes it is forced, the negative late effect of faulty perinatal vitamin-caused hormonal imprinting must be considered.

Effect of the Polylysine Based Polymeric Polypeptides on the Growth and Chemotaxis of Tetrahymena Pyriformis

Polylysine based branched polypeptides represents a group of biocompatible polymers that could be utilized as macromolecular carriers for drugs, epitopes or reporter molecules. Ten polymers with different character (amino acid composition and charge properties) were prepared: polypeptides with single amino acid in the branches (poly[Lys(Xi)]), X = His, Pro or Glu; and polymers possessing oligo[DL-alanine] side chains only (poly[Lys(DL-Alam) (AK) or with an additional amino acid residue poly[Lys(Xi-DL-Alam)] (XAK), where X = Ser (SAK), Thr (TAK), Glu (EAK), acetyl-Glu (Ac-EAK) or succinyl-Glu (Succ-EAK). were investigated. The concentration of these compounds influence the chemotaxis and survival of eukaryotic unicellular model organism, Tetrahymena pyriformis GL. Two types of experiments were performed. First the polymer induced chemoattractant/chemorepellent response of Tetrahymena cells were tested, then chemotactic selection experiments were performed. The chemotactic responses elicited by the polymers were dependent not only on chemical properties (composition, charge and the length of the side chain) of the compounds, but also on their concentration. Based on these results, the polymers were grouped as full-chemoattractant expressing this behavior in the full concentration range investigated (HiK), full-chemorepellent (EiK and Ac-EAK) and partial chemoattractant/chemorepellent with concentration dependent activity (PiK, EAK and Succ-EAK).

Hormonal imprinting in the unicellular Tetrahymena: the proto-model of epigenetics

The unicellular ciliate, Tetrahymena has a complete hormonal system. It has receptors for receiving hormones, produces, stores and secretes hormones, similar to mammalian ones and has signal transduction pathways, for transmitting the information given by the hormones. The first encounter with a hormone provokes the hormonal imprinting under the effect of which the further encounters with the same hormone induces altered (usually enhanced) reaction (hormone binding, hormone synthesis, chemoattraction, movement, growth etc.). The effect of imprinting is durable, it can be observed also after 1000 generations, or after one year in non-dividing cells. Receptors of the nuclear envelope also can be imprinted. The plasma membrane receptors provoked by imprinting are similar to the receptors of mammals. Although steroid hormones are not present in Tetrahymena, the production of them and their receptors can be induced by imprinting. The hormonal imprinting is an epigenetic process and inhibition of DNA-methylation alters the imprinting. Hormonal imprinting in Tetrahymena was likely the first epigenetic phenomenon which was justified at cellular level. It is very useful for the unicells, as it helps to avoid dangerous molecules more easily or to find useful ones and by this contributes to the permanence of the population's life.

The hormonal system of the unicellular Tetrahymena: a review with evolutionary aspects

The unicellular ciliate, Tetrahymena has receptors for hormones of the higher ranked animals, these hormones (e.g. insulin, triiodothyronine, ACTH, histamine, etc.) are also produced by it and it has signal pathways and second messengers for signal transmission. These components are chemically and functionally very similar to that of mammalian ones. The exogenously given hormones regulate different functions, as movement, phagocytosis, chemotaxis, cell growth, secretion, excretion and the cells' own hormone production. The receptors are extremely sensitive, certain hormones are sensed (and response is provoked) at 10-21 M concentration, which makes likely that the function could work by the effect of hormones produced by the Tetrahymena itself. The signal reception is selective, it can differentiate between closely related hormones. The review is listing the hormones produced by the Tetrahymena, the receptors which can receive signals and the signal pathways and second messengers as well, as the known effects of mammalian hormones to the life functions of Tetrahymena. The possible and justified role of hormonal system in the Tetrahymena as a single cell and inside the Tetrahymena population, as a community is discussed. The unicellular hormonal system and mammalian endocrine system are compared and evolutionary conclusions are drawn.

The biological basis and clinical significance of hormonal imprinting, an epigenetic process

The biological phenomenon, hormonal imprinting, was named and defined by us (Biol Rev, 1980, 55, 47-63) 30 years ago, after many experimental works and observations. Later, similar phenomena were also named to epigenetic imprinting or metabolic imprinting. In the case of hormonal imprinting, the first encounter between a hormone and its developing target cell receptor-usually at the perinatal period-determines the normal receptor-hormone connection for life. However, in this period, molecules similar to the target hormone (members of the same hormone family, synthetic drugs, environmental pollutants, etc), which are also able to bind to the receptor, provoke faulty imprinting also with lifelong-receptorial, behavioral, etc.,-consequences. Faulty hormonal imprinting could also be provoked later in life in continuously dividing cells and in the brain. Faulty hormonal imprinting is a disturbance of gene methylation pattern, which is epigenenetically inherited to the further generations (transgenerational imprinting). The absence of the normal or the presence of false hormonal imprinting predispose to or manifested in different diseases (e.g., malignant tumors, metabolic syndrome) long after the time of imprinting or in the progenies.

Hormonal effects on Tetrahymena: change in case of combined treatment

In order to approach their natural conditions, populations of Tetrahymena were kept in Losina-Losinky's salt solution for 1 h, than in the tryptone+yeast medium. During this time they were treated with histamine, serotonin or insulin, or with the combinations of these hormones. Effect of the combined treatments on the production of serotonin (5HT), or adrenocorticotropic hormone (ACTH) or triiodothyronine (T₃) by the cells was compared to the effect of single-hormone treatments. Significant differences were seen between the results obtained following the single or combined treatments. There was no summation of the effects, however an elevation or diminution of the hormone production was observed after the combined treatment, as compared with the untreated controls or with the use of one of the hormones in the samples. The experiments demonstrate that there is a hormonal regulation between the Tetrahymena cells and the hormones influence each other's effect.

[Hormonal imprinting--the unforeseeable future]

Hormonal imprinting takes place at the first encounter between the developing receptor and the target hormone, perinatally, causing life-long changes in the binding capacity of the receptor and the indexes influenced by it. Perinatal hormonal imprinting is absolutely needed for the maturation of receptor, however, at the same time, molecules similar to the target hormone (related hormones, synthetic drugs acting at receptor level, chemicals, environmental pollutants etc.) can cause faulty imprinting, also with (morphological, biochemical, receptorial, behavioral) consequences for life. Although imprinting is characteristic and inevitable perinatally, it can be provoked in any period of life in developing cells, especially at the weanling and adolescent age (late imprinting). There is no gene mutation during imprinting, however, the methylation pattern of the genes changes and that inherits epigenetically the imprinting, which is manifested in disposition to diseases or in diseases (e.g. tumor formation, metabolic syndrome). Imprinting is inherited between generations that could cause--in the present chemical world--evolutionary consequences. Thus, medicaments or preventive drugs, e.g. pregnancy protecting drugs or oral contraceptive pills should be given cautiously, especially in the critical periods, considering that consequences are manifested always after a long period (sometimes decades) or in the next generations.

Effect of neonatal nociceptin or nocistatin imprinting on the brain concentration of biogenic amines and their metabolites

Noradrenaline (NA), dopamine (DA), homovanillic acid (HA), serotonin (5HT) and 5-hydroxyindole acetic acid (5HIAA) content of five brain regions (hypothalamus, hippocampus, brainstem, striatum and frontal cortex) and the cerebrospinal fluid (CSF) was measured in adult (three months old) male and female rats treated neonatally with a single dose of 10 microg nociceptin (NC) or 10 microg nocistatin (NS) for hormonal imprinting. The biogenic amine and metabolite content of cerebrospinal fluid was also determined. In NC treated animals the serotonergic, dopaminergic as well as noradrenergic systems were influenced by the imprinting. The 5HT level increased in hypothalamus, the 5HIAA tissue levels were found increased in hypothalamus. Hippocampus and striatum and the HVA levels increased highly significantly in brainstem. Dopamine level decreased significantly in striatum, however in frontal cortex both noradrenalin and 5HIAA level decreased. Nevertheless, in NS-treated rats decreased NA tissue levels were found in hypothalamus, brainstem and frontal cortex. Decreased DA levels were found in the hypothalamus, brainstem and striatum. NS imprinting resulted in decreased HVA level, but increased one in the brainstem. The 5HT levels decreased in the hypothalamus, brainstem, striatum and frontal cortex, while 5HIAA content of CSF, and frontal cortex decreased, and that of hypothalamus, hippocampus and striatum increased. There was no significant difference between genders except in the 5HT tissue levels of NC treated rats. Data presented show that neonatal imprinting both by NC and NS have long-lasting and brain area specific effects. In earlier experiments endorphin imprinting also influenced the serotonergic system suggesting that during labour release of pain-related substances may durably affect the serotonergic (dopaminergic, adrenergic) system which can impress the animals' later behavior.

Effect of concanavalin A (Con-A) on the hormone production of the unicellular Tetrahymena and the immune cells of the rat. A comparative study

Tetrahymena populations were treated with 10(-15) g ml(-1) or 10(-6) g ml(-1) concanavalin-A (Con-A) in tryptone-yeast medium for 1 h. Rat peritoneal immune cells (mast cells, lymphocytes, monocyte-granulocyte group) were also treated with 10(-6) g ml(-1) Con-A, for 1 h. The cells' hormone (ACTH, histamine, serotonin, endorphin, triiodothyronine (T(3))) content was measured by using immunocytochemistry and flow cytometry. The extremely low dose of Con-A universally and significantly elevated the hormone contents, while the result of higher dose was uncertain. In the immune cells, Con-A significantly decreased the ACTH level in each cell type and histamine level in mast cells. The results demonstrate the very high sensitivity of Tetrahymena receptors for a non-hormone (lectin) molecule, which can bind to the insulin receptors and mimics the effect of insulin. The results also show that Tetrahymena receptors are more sensitive to lower concentrations of molecules than to higher ones. The universal hormone-production stimulating effect of Con-A-which is observed in Tetrahymena-is specified in rat.

Effect of neonatal benzpyrene imprinting on the brain serotonin content and nocistatin level in adult male rats

Single neonatal treatment (imprinting) with 20 microg benzpyrene results in significant increase of the brain serotonin level in the striatum, while in the other four regions (cortex, brainstem, hippocampus, hypothalamus) when measured in adults can be detected. The nocistatin level of cerebrospinal fluid (CSF) significantly decreases, while there is no change in the plasma nocistatin level. The results call attention to the comprehensive imprinting effect of benzpyrene, which in addition to receptorial, hormonal and sexual behavioral disturbances causes lasting differences in the brain serotonin and nocistatin levels, probably influencing mood and pain tolerance.

Perinatal alcohol exposure enhances nocistatin levels in adulthood

In earlier experiments perinatal hormonal imprinting by alcohol decreased the hormone content of immune cells for life. In the present study, both a single day (15% on the third postnatal day) and a long-term treatment schedule of alcohol exposure (3% for 21 days) of dams during lactation significantly (P < 0.01) enhanced endogenous levels of nocistatin in the blood plasma as well as in the cerebrospinal fluid of the offspring, measured in 3-month-old rats. Our data suggest that alcohol consumption during lactation can cause a life-long influence on nocistatin levels in the offspring and most likely modify nocistatin-related functions such as pain tolerance.

Hormonal imprinting: phylogeny, ontogeny, diseases and possible role in present-day human evolution

Hormonal (chemical) imprinting which was first observed (and named) by us in the seventies of the last century, is a general biological phenomenon which takes place when the developing receptor meets its target hormone for the first time. Under the effect of imprinting, receptors mature and reach their maximal binding capacity. It also influences the cells' hormone production and different functions depending on receptors and hormones. Hormonal imprinting is present already at the unicellular level causing the development of specific receptors and helping the easier recognition of useful or harmful surrounding molecules. The phenomenon is an important factor in the survival of the species, as the effect of imprinting is transmitted to the progeny cell generations. At the same time it possibly helps the selection of molecules which are suitable for acting as hormones in higher ranked animals. In mammals, hormonal imprinting takes place perinatally and determines the function of receptor-signal-transduction systems as well as hormone production for life. However, there are other critical imprinting periods for continuously developing cells. Excess of the target hormones or presence of foreign molecules which are able to bind to the receptors, provoke faulty imprinting in the critical periods with life-long morphological, biochemical, functional or behavioural consequences. As many receptor-bound foreign molecules are used as medical treatments and many such molecules are present around us and inside us as environmental pollutants, they--causing faulty imprinting--are able to predispose the (human) organism to cardiovascular, endocrine, metabolic and cancerous diseases. It seems likely that this effect is connected with disturbance of DNA methylation process in the critical periods of life. There are some signs of the transgenerational effect of faulty imprinting and this could be manifested in the evolution of humans by an epigenetic route.

How does the unicellular Tetrahymena utilise the hormones that it produces? Paying a visit to the realm of atto-and zeptomolar concentrations

Changes in the hormone content of Tetrahymena pyriformis GL were investigated during histamine, serotonin or insulin treatment at concentrations of 10(-6)M to 10(-21)M for 30 min. The immunologically demonstrable hormone content was studied by using specific antibodies, flow cytometry and confocal microscopy. Histamine at the higher ranges elevated the serotonin content of Tetrahymena, whereas serotonin at the lower ranges (down to 10(-21)M) decreased its histamine levels. Insulin did not affect its serotonin content, whereas serotonin increased its insulin content at each concentration studied (down to 10(-21)M). Insulin between 10(-6)M and 10(-21)M increased the histamine levels of Tetrahymena, although histamine influenced its insulin level only at 10(-6)M. Our results call attention to the presence of hormonal interactions even at "low" levels of phylogeny and to the extreme sensitivity of the hormone receptors of Tetrahymena. These data might explain (1) the requirement of Tetrahymena for (vertebrate) hormone production and hormone receptors and (2) the way that it uses these hormones under natural conditions.

Pseudopterosin A inhibits phagocytosis and alters intracellular calcium turnover in a pertussis toxin sensitive site in Tetrahymena thermophila

The free living ciliate Tetrahymena thermophila was chosen as a cellular model in order to investigate the mode of action of the anti-inflammatory marine natural product Pseudopterosin A (PsA). In this paper we present evidence that PsA inhibits phagosome formation (KD=10.5 microM) and triggers a discrete intracellular calcium release (depletion) from a site in T. thermophila cells (KD=6.4 microM). Pre-treatment with the Gi/o protein inhibitor, pertussis toxin (PTX), inhibits PsA activity of both responses providing pharmacological evidence that the site of action for PsA is at a PTX sensitive G protein or a G protein coupled receptor (GPCR). Addition of extracellular calcium induced a concentration dependent increase in the incidence of phagosome formation (KD=30.3 microM) and was blocked by PsA pre-treatment. This particular effect of PsA on extracellular calcium was not blocked by PTX pre-treatment.

Changes in the endorphin and serotonin content of rat immune cells during adulthood following maternal exposure to ethanol during pregnancy and lactation

Lactating and lactating/pregnant rat dams consumed either 3% (vol/vol) ethanol (as the sole source of fluid) between the 1st and 21st days after delivery or 15% (vol/vol) ethanol for 24h on the 3rd day after delivery. Offspring of ethanol-consuming dams were compared with offspring of untreated control dams. In other groups, offspring of mothers given 3% ethanol during pregnancy were also compared to untreated controls. When the offspring were 2 months of age, endorphin and serotonin contents of immune cells (lymphocytes, granulocytes and monocytes, mast cells of the peritoneal fluid, and lymphocytes of the thymus) were determined by hormone-specific antibodies and flow cytometric as well as confocal microscopic analysis. In rats exposed to ethanol through breast-feeding, endorphin content significantly decreased in thymic cells independent of the alcohol concentration (and duration) during treatment. Each type of peritoneal cell contained significantly more serotonin after 3% alcohol treatment. For the prenatally exposed offspring, serotonin content significantly decreased for both ethanol treatment conditions during pregnancy. Remarkably, one day of exposure to 15% ethanol on the third day of pregnancy was sufficient to induce this enduring change in serotonin content of immune cells of offspring. Considering that endorphin and serotonin are important immunomodulators, these alcohol-induced changes could produce enduring influences on immune function.

Prolonged effect of endorphin treatment during pregnancy in the rat on the histamine content of immune cells of F1 and F2 offspring generations

Female rats were treated with beta-endorphin on the 19th day of pregnancy and the histamine content of immune cells (blood lymphocytes; peritoneal lymphocytes, monocyte-macrophage-granulocyte group, mast cells; thymic lymphocytes) of the 7-week-old progenies (F1 generation) was studied using a flow-cytometric immunocytochemical technique. In an other group, female F1 progenies of endorphin-treated mothers were mated with control males and the F2 generation was monitored for histamine content similar to the F1. In the F1 generation each cell type, except peritoneal and blood lymphocytes, contained significantly more histamine than the control cells. In the F2 generation only mast cells contained significantly more histamine relative to the appropriate control. This means that the effect of endorphin (hormonal) imprinting is transmitted transgenerationally, but with decreasing intensity however. Mast cells retained the effect of imprinting for longer than the other cells. The results are compared with the levels of serotonin in similarly treated animals, studied in earlier experiments. As the endorphin level can be elevated during pregnancy (by pain, traumatization, or other stress conditions) this can the set biogenic amine content of adult immune cells.

Effect of drugs affecting microtubular assembly on microtubules, phospholipid synthesis and physiological indices (signalling, growth, motility and phagocytosis) inTetrahymena pyriformis

Structural changes of microtubules, incorporation of radioactively labelled components into phospholipids, cell motility, growth and phagocytosis were studied under the effect of four drugs affecting microtubular assembly: colchicine, nocodazole, vinblastine and taxol. Although the first three agents influence microtubules in the direction of depolymerization and the fourth stabilizes them, their effects on the structure of microtubules cannot be explained by this. Using confocal microscopy after an acetylated anti-tubulin label, in nocodazole- and colchicine-treated cells, the basal body cages disappear and longitudinal microtubules (LM) became thinner without changing transversal microtubules (TM). After taxol treatment LM also became thinner, however TM disappeared. Under the effect of vinblastine TM became thinner, without influencing LM. These drugs influence the incorporation of components ([(3)H]-serine, [(3)H]-palmitic acid and (32)P) into phospholipids, however their effect is equivocal and cannot be consequently coupled with the effect on the microtubules. Nocodazole, vinblastine and taxol significantly reduced the cell's motility, however colchicine did so to a lesser degree. Vinblastine and nocodazole totally inhibited, and taxol significantly decreased cell growth, while colchicine in a lower concentration increased the multiplication of cells. Phagocytosis was not significantly influenced after 1 min, but after 5 min all the agents studied (except colchicine) significantly inhibited phagocytosis. After 15 and 30 min each molecule caused highly significant inhibition. The experiments demonstrate that drugs affecting microtubular assembly dynamics influence differently the diverse (longitudinal, transversal etc.) microtubular systems of Tetrahymena and also differently influence microtubule-dependent physiological processes. The latter are more dependent on microtubular dynamics than are changes in phospholipid signalling.

Synthesis of oligotuftsin-based branched oligopeptide conjugates for chemotactic drug targeting

The synthesis and chemotactic properties of a new class of branched oligopeptide-based conjugates are described. Tetratuftsin derivatives containing chemotactic formyl tripeptides (For-MLF, For-NleLF or For-MMM) in branches were prepared by stepwise solid-phase peptide synthesis. The influence of the composition and ionic charge of the carrier-branched oligopeptide on the chemotactic behaviour of the conjugate was studied in Tetrahymena pyriformis. Conjugates with methotrexate (Mtx) as a drug component was also prepared. For this, a GFLGC spacer, cleavable by cathepsin B, was used. The spacer with N-terminal methotrexate was coupled to the chloroacetylated chemotactic carrier molecule by thioether bond formation. The chemotactic activity and cytotoxity of Mtx conjugates were also studied.

Is the brain hormonally imprintable?

Hormonal imprinting develops at the first encounter between the target hormone and its developing receptor in the perinatal critical period. This determines the binding and response capacity of the receptor-signal transduction system and hormone production of cells for life. Molecules similar to the hormone and excess or absence of the target hormone cause faulty imprinting with lifelong consequences. Prenatal or neonatal imprinting with opiates, other drugs and prenatal stress have harmful consequences on the adult brain. Perinatal imprinting with endorphin or serotonin decreases the serotonin level of the brain while increasing sexual activity and (as in the case of endorphin) aggression. Endorphin or serotonin antagonist treatment at weaning (late imprinting) also significantly reduces the serotonin content of the brain. Backed by literary data, these observations are discussed, and the possible consequences of medical treatments are shown. The paper concludes that an excess of molecules produced by the brain itself can provoke perinatal imprinting, and it points to the possibility of late imprinting of the brain by receptor level acting agents, including a brain product (endorphin).

Molecules acting on receptor level at weaning, durably influence liver glucocorticoid receptors

In the experiments the effect of late hormonal imprinting to the liver glucocorticoid receptors were studied. Three-week-old (weanling) female rats were treated with five molecules acting at receptor level and four weeks later receptor kinetic analysis was done on liver glucocorticoid receptors. The tricyclic antidepressant, histamine and serotonin receptor blocker mianserin positively influenced receptor density and negatively receptor affinity. Vitamin D3 and the environmental pollutant benzpyrene elevated receptor density. Mifepristone (RU 486) which is bound by progesterone- and glucorticoid-receptor without postreceptorial effects was ineffective as well, as the H1 receptor blocker chlorpheniramine. The results demonstrate that receptor-level-acting foreign molecules can durably influence the binding capacity of glucocorticoid receptors, however, this is not a general phenomenon and it is not dependent on the type of receptors (membrane or cytosol). Those molecules were effective which 1. have receptor in the same receptor family (vitamin D3) and have postreceptorial effect, or 2. have a structure similar to steroids (benzpyrene) or 3. deeply influenced steroid receptors in earlier experiments (mianserin). This effect should be considered before administering such type of medicaments.

Influence of acute stress on the triiodothyronine (T3) and serotonin content of rat's immune cells

Stress caused by 48 h food and water deprivation provoked significant changes in T3 and serotonin content of lymphocytes. The concentration of these hormones decreased in the last hour of stress. However, 48 h later there was no difference between the hormone content of immune cells of stressed and control animals. Since in earlier experiments three weeks after exposed to stress a significant difference between the control and stressed animals was found, this means that an imprinting-like phenomenon happened with consequences manifested later. The most sensitive cells to acute stress are lymphocytes, however the imprinting influences all types of of the immune cells.

Acute and delayed effect of (−) deprenyl and (−) 1-phenyl-2-propylaminopentane (PPAP) on the serotonin content of peritoneal cells (white blood cells and mast cells)

Acute and delayed (hormonal imprinting) effect of (-) deprenyl and its derivative without MAO-B inhibitory activity (-) PPAP, were studied on cells of the peritoneal fluid (lymphocytes, monocytes, granulocytes and mast cells) by flow cytometric and confocal microscopic analysis. Thirty minutes after treatment of 6-week-old female animals, deprenyl was ineffective while PPAP significantly increased the serotonin level of these cells. Three weeks after treatment at weaning, deprenyl drastically decreased the serotonin level of each cell type, while PPAP moderately but significantly increased the serotonin level of monocytes, granulocytes and mast cells. This means that the two related molecules have different effects on the immune cells, which seem to be independent of MAO-B inhibition. The experiments emphasize the necessity of studying the prolonged effects of biologically active molecules, even if they are without acute effects. As serotonin is a modulator of the immune system, the influence on immune cells of the molecules studied can contribute to their enhancing effect.

Effect of single neonatal or repeated benzpyrene exposure on the serotonin content of immune cells in young male rats

In earlier experiments single benzpyrene treatment of newborn rats caused strong alterations in the endorphin content of adult rats' immune cells. In the present experiments young (4-6 weeks old) male rats were studied for demonstrating the effect of the single neonatal or repeated (neonatally and at weanling) benzpyrene exposure on the serotonin content of immune cells (blood lymphocytes, monocytes, granulocytes; peritoneal fluid lymphocytes, mast cells, monocytes and granulocytes, thymic lymphocytes). Flow cytometric analysis showed that 50 microg benzpyrene treatment of five-week-old animals was ineffective after 5 days and this was the situation four weeks after single neonatal (20 microg) benzpyrene exposure. However, the repeated treatment of neonatally benzpyrene exposed 4 weeks old animals after 5 days resulted in elevated blood and thymic lymphocyte serotonin amount and in one index (peritoneal monocyte-granulocyte group) reduced serotonin content. This means that neonatal benzpyrene treatment does not influence directly the serotonin content (production or transport) of immune cells (unlike to the endorphin content) however, sensitizes them to a following benzpyrene exposure. The results widen the list of harmful effects (influencing steroid receptor binding, sexual behavior and immune cells' endorphin content) of perinatal benzpyrene exposure.

Effect of treatment at weaning with the serotonin antagonist mianserin on the brain serotonin and cerebrospinal fluid nocistatin level of adult female rats: a case of late imprinting

Four weeks old (weanling) female rats were treated with the tricyclic antidepressant and histamine/serotonin receptor blocker mianserin for studying its faulty hormonal imprinting effect. Measurements were done four months later. Brain serotonin levels significantly decreased in four regions (hippocampus, hypothalamus, striatum and brainstem), without any change in the cortex. Sexual activity of the treated and control rats was similar. Cerebrospinal fluid nocistatin level was one magnitude higher in the treated rats, than in the controls. The density of uterine estrogen receptors was significantly reduced, while binding capacity of glucocorticoid receptors of liver and thymus remained at control level. The results call attention to the possibility of 1. a broad spectrum imprinting at the time of weaning by a receptor level acting non-hormone molecule 2. imprinting of the brain in a non-neonatal period of life and 3. a very durable (lifelong?) effect of the late imprinting with an antidepressant.

Single neonatal treatment with β-endorphin (hormonal imprinting) extremely enhances nocistatin level of cerebrospinal fluid in adult rats

In earlier experiments endorphin treatment of newborn rats caused the decrease of brain serotonin content, increasing aggressivity, enhanced sexual activity of females and changes in the binding capacity of uterine estrogen receptors at adult age, however nociceptin content of the cerebrospinal fluid was not changed. In the present experiment neonatal treatment of male and female rats was done with a single dose of 3 microg beta-endorphin and in five months old rats the level of nociceptin antagonist nocistatin was determined by radioimmunoassay in the cerebrospinal fluid. In both genders the amount of nocistatin was one magnitude higher in the endorphin treated groups. There was also a significant difference between the male and female nocistatin level in the treated and non-treated groups alike, with the advantage of females. The results call attention to the possibility of influencing pain-tolerance for life, by the pain-provoked endorphin levels during delivery.

Impact of single neonatal serotonin treatment (hormonal imprinting) on the brain serotonin content and sexual behavior of adult rats

Hormonal imprinting takes place perinatally at the first encounter between the developing receptor and its target hormone. As a consequence of imprinting the receptor accomplishes its maturation and reaches the binding capacity characteristic to the adult age. In the excess of target hormone or presence of molecules similar to the target hormone, which are able to bind to the unmatured receptors, faulty imprinting develops with life-long consequences. At present, serotonin was given to neonatal rats and their sexual activity, brain serotonin level and steroid receptor's binding capacity was measured in adult age. Brain serotonin level was significantly reduced in male's striatum and parallel with this, male's sexual activity significantly increased. In other regions of the male brain (prefrontal cortex, hypothalamus, hippocampus) there was a statistically non-significant tendency for a decrease in serotonin level. No significant differences were detected in female brain values, and there was only slight change in female's sexual activity. There was also no change in the binding capacity of thymic glucocorticoid and uterine estrogen receptors. The experiments call attention to the possibility of perinatal imprinting by a neurotransmitter causing changes in brain neurotransmitter level for life, which is manifested in altered sexual activity.

Endorphin content of white blood cells and peritoneal cells in neonatally benzpyrene treated adult rats

White blood cells of rats (lymphocytes, monocytes, macrophages, granulocytes and mast cells) contain beta-endorphin. Two months after a single neonatal benzpyrene treatment (imprinting) there is an elevated level of immunoreactive endorphin in the blood and peritoneal cells of female animals and blood cells of males. The endorphin content decreased in the peritoneal cells of males. In the blood, the granulocytes of female, and the lymphocytes of male rats contained the highest amount of endorphin. In the peritoneal fluid also the granulocytes of females contained the highest amount of endorphin, in contrast to males, where the endorphin content of cells decreased and the lowest level of it was present in the lymphocytes. The experiments justify that benzpyrene treatment can durably influence endorphin levels of white blood cells and gives new data to the already known lifelong health destroying effects of perinatal benzpyrene exposition (alterations of hormone receptor binding capacity and sexual behavior).

Effect of single neonatal treatment with the soy bean phytosteroid, genistein on the sexual behavior of adult rats

Hormonal imprinting develops during the perinatal critical period, when the target hormone meets the yet unmatured receptor. As a consequence of imprinting the receptor accomplishes its maturation reaching the binding capacity characteristic to adults. In this period in the presence of foreign molecules similar to the target hormone faulty imprinting may occur with life-long consequences. Soy bean contains phytosteroids which can mimic estrogen effects. In the present experiments single genistein (20 microg) or combined genistein + benzpyrene (20 microg) treatments were done neonatally and the sexual behavior of male and female adult animals was studied. Genistein significantly increased the lordosis quotient of females, which was compensated by neonatal benzpyrene treatment. Genistein also enhanced the sexual activity of males, and this was significantly not reduced by parallel benzpyrene treatment. The results show that neonatal genistein exposure can imprint sexual activity for life and the presence of a second imprinter can modify genistein's behavioral effect.

Prolonged effect of a single serotonin treatment in adult age on the serotonin and histamine content of white blood cells and mast cells of rats

Hormonal imprinting was provoked by serotonin treatment in adult age. Three weeks after treatment with 100 microg serotonin, the serotonin and histamine content of peritoneal cells (mast cells, lymphocytes and the monocyte-macrophage-granulocyte group), white blood cells (lymphocytes, granulocytes and monocytes) and thymic lymphocytes was studied by flow cytometry. The content of both amines was significantly higher in the mast cells of males and lower in females. Blood lymphocytes contained a higher serotonin and histamine level in males, and a lower serotonin level in females. The peritoneal monocyte-macrophage-granulocyte group contained less serotonin in both males and females. Thymocytes contained higher levels of both amines in females and higher histamine level in males. The experiments demonstrate that a single treatment at adult age can provoke imprinting, which alters-in the present case-the serotonin and histamine content of immune cells durably.

Effect of neonatal beta-endorphin imprinting on sexual behavior and brain serotonin level in adult rats

A single dose (3 microg) beta-endorphin was administered to newborn female and male rats (hormonal imprinting). In adult age (at 5 months) sexual behavior, steroid hormone binding capacity and brain serotonin content was studied. Females' sexual activity (lordosis quotient) significantly decreased and more animals protested against mounting (ratio of kicking and crying 21/24 vs. 8/24; p < 0.001). Males' sexual activity did not change, however more males were aggressive (4/10 vs. 1/10). Uterine estrogen receptor density significantly increased and affinity decreased. There was no change in the binding capacity of thymic glucocorticoid receptors. In the brain, five regions were studied for serotonin content. There was a gender difference in serotonin level and the intragroup differences were also high. In the endorphin treated males the serotonin level was significantly lower than in the controls. In the endorphin treated females the intragroup scattering has been significantly reduced. Nociceptin content of the cerebrospinal fluid was not changed. The experiments call attention to the possibility of adjustment of sexual and behavioral sphere by the individually different endorphin surge during labor.

Melatonin in the unicellular Tetrahymena pyriformis: effects of different lighting conditions

Melatonin content in the cellular fraction and medium of Tetrahymena pyriformis GL cultures was measured at different time points of light and dark exposures. Tetrahymena produced, stored and secreted immunoreactive melatonin, which in displacement and HPLC studies, behaved like synthetic melatonin. There was not a continuous secretion of melatonin produced by the cells. In contrast to this, storage of melatonin was observed, which was more expressed in dark conditions. Prolonged light exposure suppressed melatonin production and secretion alike, however it did not block it completely.

Prolonged impact of pubertal serotonin treatment (hormonal imprinting) on the later serotonin content of white blood cells

The first encounter between the developing receptor and its target hormone establishes the hormonal imprinting which is needed for the normal function of the cell. In the presence of foreign-however able to bind-molecules, faulty imprinting develops with lifelong consequences. Hormonal imprinting influences not only the receptors, but also the later hormone production of cells. The critical time of hormonal imprinting is the perinatal period, however it can be executed sometimes (in continuously differentiating cells) also at puberty. As in earlier experiments single neonatal serotonin treatment caused a life-long alteration of white blood serotonin content in female rats, the early (10-19 day) and late (8 weeks) effect of single pubertal serotonin treatment was studied presently, by using flow cytometry. In contrast to the earlier (neonatal) results, pubertal treatment caused a radical reduction of serotonin content in male's lymphocytes, monocytes, granulocytes and mast cells, independent on the time of study. The effect in females was rather increasing, however uncertain. The experiments call attention to the possible different effects of neonatal and pubertal hormonal imprinting and to the imprintability of blood cells in adolescence.

Effect of tamoxifen treatment at adolescent age on the sexual behaviour and steroid hormone receptor binding of adult female rats

Hormonal imprinting takes place perinatally, at the first encounter between the target hormone and its developing receptor. However, there is a secondary critical period of imprinting at puberty. In these periods molecules similar to the hormones (members of the same hormone family, antagonists, certain environmental pollutants, etc.) can cause faulty imprinting with lifelong consequences. In the present experiments 5+2 days of tamoxifen treatment (120 microg/day) at adolescent age dramatically (from approx. 40% to 10%) reduced the sexual activity (Meyerson index and lordosis quotient) of female rats, soon after the finishment of the treatment and between four to six weeks after treatment. Similar results were observed in animals neonatally treated with allylestrenol and tamoxifen treated at puberty. Thymic glucocorticoid receptor and uterine estrogen receptor binding capacity were not influenced.

Binding capacity of rat liver glucocorticoid receptor in different periods after single neonatal benzpyrene treatment (imprinting)

Newborn rats of both sexes were treated (imprinted) with 20 microg of benzpyrene. Two hours, 2 days, 1, 2, 3 weeks, 1 month and 2 months after imprinting the liver glucocorticoid receptors were studied for binding of dexamethasone. Two-hour and 2-day values were not appreciable. One week after treatment the receptor's affinity was extremely low both in control and treated treated animals. Two weeks after imprinting a significant difference in density (lower) and affinity (higher) was observed between the male treated and control animals. At 3 weeks and one month the binding capacity of treated and control animals was equal however, at 2 months Bmax of males increased and that of females decreased significantly in the neonatally benzpyrene treated animals. This means that for the development of perinatal imprinting effect a long time is needed, and the effect is manifested after a period of lability.

Effect of a single treatment (imprinting) with genistein or combined treatment with genistein+benzpyrene on the binding capacity of glucocorticoid and estrogen receptors of adult rats

Hormonal imprinting takes place perinatally at the first encounter between the hormone and its target receptor. This is needed for the normal finishment of the maturation of the receptor-signal transduction system. In excess of foreign molecules, which can also bind to the receptor, faulty imprinting develops with life-long consequences. Genistein, a soybean phytosteroid (isoflavone), has estrogen-like effects and can be bound by steroid receptors. In the present experiments, single neonatal treatment (imprinting) with 20 microg of genistein, or combined treatment with 20 microg of genistein+20 microg of benzpyrene was done and liver and thymus glucocorticoid receptors of adult male and female rats and uterine estrogen receptors were studied. There was no difference in the binding capacity of uterine estrogen receptors. Genistein treatment alone caused a significant reduction of liver glucocorticoid receptor density in males; however, there were no other significant alterations. After combined genistein+benzpyrene treatment, more.than half of the thymus and liver glucocorticoid receptor values significantly changed. The results call attention to the imprinting-modifying effect of a second (environmental) imprinter.

Effect of quinacrine treatment on the activity of acid hydrolases (phosphatase, N-acetyl-beta-glucosaminidase, glucosidase, galactosidase and esterase) in Tetrahymena

The effect of phospholipase A2 (PLA2) inhibitor, quinacrine, on the activity of hydrolytic enzymes in Tetrahymena pyriformis homogenate, was investigated. The activity of all of the enzymes studied (acid phosphatase, N-acetyl-beta-glusosaminidase, glucosidase, galactosidase and esterase) was significantly reduced in the presence of quinacrine. Since there are no data on the inhibitory effect of PLA2 and PLA2 influenced metabolic pathways to the hydrolytic enzymes, the direct effect of quinacrine on the hydrolytic enzymes (of Tetrahymena) can be supposed. This is supported by the fact that the other PLA2 inhibitor, 4-bromophenacyl bromide, did not influence phosphatase activity.

Effects of phosphoprotein phosphatase inhibitors (phenylarsine oxide and cantharidin) on Tetrahymena

The effects of phenylarsine oxide (PAO) (phosphotyrosine phosphatase inhibitor) and cantharidin (serine/threonine phosphatase [PP2A] inhibitor) treatments were analysed on the synthesis of phospholipids and glycolipids, and on the cytoskeletal elements (F-actin and tubulin containing structures) of Tetrahymena pyriformis. Both phosphatase inhibitors reduced the amount of incorporated 32P of the whole phospholipid content, but the ratio of phosphatidylserine (PS) and phosphatidylcholine (PC) to the total phospholipid content increased. Both treatments influenced the phosphatidylinositol (PI) system. These inhibitors also influenced the incorporation of palmitic acid into the phospholipids: in general PAO decreased, whereas cantharidin increased the amount of incorporated palmitic acid; 1 microM cantharidin significantly increased the labelling of PE and PA. The incorporation of mannose and glucosamine was influenced differently by PAO and cantharidin treatments: the latter elevated, while PAO decreased the labelling of glycolipids with these sugars. The effects of these treatments were visible also in the case of confocal scanning laser microscopic (CSLM) images: after treatments with both inhibitors, the F-actin containing cortical elements were destroyed, but the tubulin containing ones (longitudinal and transversal microtubules, oral apparatus and deep fibres) did not display significant alterations. The different effects of phosphatase inhibitors were visible also on the scanning electron microscopic (sEM) images: cantharidin treatments (1 microM) decreased the amount of dissolved membrane lipids after chemical dehydration of the cells with 2, 2-dimethoxy propane (DMP), but in the case of treatments with 10 microM, the surface pattern of cells was similar to the controls. On the other hand, after PAO treatments the surface pattern of Tetrahymena showed significant alterations. Both phosphatase inhibitors inhibited the phagocytotic activity of the cells. On the basis of present experiments we suppose that these treatments are able to influence signalling systems (e.g. PI) of Tetrahymena, and also the structure of the cytoskeleton and the functions (e.g. phagocytosis) which are connected with skeletal elements.

The effect of a single neonatal treatment (hormonal imprinting) with the antihormones, tamoxifen and mifepristone on the sexual behavior of adult rats

Hormonal imprinting takes place perinatally during the first encounter between the hormone and its developing receptor. The presence of an excess of related molecules in that time provokes faulty (pathological) imprinting. In the present experiments single-neonatal treatment with 100 microg of tamoxifen completely abolished the adult male and female rats' sexual activity. Similar treatment with 100 microg of mifepristone (RU486) significantly enhanced the males sexual activity and non-significantly increased that of the females. The results demonstrate the importance of pathological imprinting during the perinatal development of sexual behavior. There are clear differences between the molecules having steroid (mifepristone) or non-steroid (tamoxifen) character, mediated through a ligand-receptor complex, and its effect in activating particular genes.

Influence of a single treatment with vitamin E or K (hormonal imprinting) of neonatal rats on the sexual behavior of adults

The effect of a single neonatal treatment (imprinting) with vitamin E or vitamin K1 on the sexual activity of three-month old rats, was studied. In female animals vitamin E treatment significantly lowered the Meyerson index and lordosis quotient, among males there were significantly more inactive animals and no multiple ejaculations could be observed. Vitamin K1 treatment caused only slight changes in the same direction, in both sexes. Considering also earlier results concerning vitamin A and D neonatal treatments (alterations in receptor binding capacity, sex hormone levels and sexual behavior), and receptorial changes caused by neonatal vitamin E and K1 treatments, the present experiment also calls attention to the lifelong effects of perinatal treatment with lipid soluble vitamins.

Insulin uptake, localization and production in previously insulin treated and untreated Tetrahymena. Data on the mechanism of hormonal imprinting

Confocal microscopic experiments demonstrate the presence of insulin in Tetrahymena, observed also in earlier experiments. However, there is a broad spectrum of insulin-containing cells from the immunocytochemically insulin-free, to the strongly antibody-reactive ones. During 1 h of insulin treatment (imprinting) the cells gradually bind and take up insulin, and the process is slow. One minute after the start of treatment there is not difference in the number of insulin antibody-reactive cells and amount of insulin. After 5 or 10 min the cells bind and contain more insulin and after 1 h most of the cells are densely packed with the insulin antibody-reactive material. Insulin imprinting accelerates binding and uptake alike: 48 h after imprinting and 1 min after the start of the second treatment, more insulin is present on the surface and inside the cells, than after 10 min in the first-time treated cells. Theoretically, this effect of hormonal imprinting helps to maintain the species by facilitating molecular recognition and binding as well as uptake of useful molecules. The experiments also support previous observations on the parallel receptor-evoking (strengthening) and hormone-producing effect of hormonal imprinting.

Chemotactic selection of Tetrahymena pyriformis GL induced with histamine, di-iodotyrosine or insulin

It has been hypothesized that in phylogeny the encounter between potential signalling molecules and the continously changing cell membrane could result in the formation of a ligand specific receptor. This chemical (hormonal) imprinting is then transmitted to the progeny generations. It is, however, very difficult to know whether the selection of cells with receptor-like patterns or amplification of complete receptor-like patterns led to the formation of the receptor-hormone complex. The new technique of 'chemotactic selection provides a physiological response-guided selection of cells. It also enables the testing of subpopulations with the characteristic selector ligand. We show here that of three chemotactic ligands (histamine, di-iodotyrosine (T2) and human insulin), insulin and T2 selected subpopulations express a significantly high chemotactic response. Since the control medium has a selector capacity itself, we introduced a chemotactic selection coefficient (Chsel) which facilitates the comparison of all groups. Using this factor we found that insulin (Chsel = 1.57), functions as a strong selector and T2 (Chsel = 0.98), was a weak selector. Morphometric evaluation of the cells showed a good correlation between chemotactic responsiveness and morphometric characteristics of subpopulations selected with insulin and histamine. T2 data suggest that the long lasting responsiveness is not general, but might be subpopulation specific.