Emotional regulatory function of receptor interacting protein 140 revealed in the ventromedial hypothalamus.

Receptor-interacting protein (RIP140) is a transcription co-regulator highly expressed in macrophages to regulate inflammatory and metabolic processes. However, its implication in neurological, cognitive and emotional conditions, and the cellular systems relevant to its biological activity within the central nervous system are currently less clear. A transgenic mouse line with macrophage-specific knockdown of RIP140 was generated (MΦRIPKD mice) and brain-region specific RIP140 knockdown efficiency evaluated. Mice were subjected to a battery of tests, designed to evaluate multiple behavioral domains at naïve or following site-specific RIP140 re-expression. Gene expression analysis assessed TNF-α, IL-1ß, TGF-1ß, IL1-RA and neuropeptide Y (NPY) expression, and in vitro studies examined the effects of macrophage's RIP140 on astrocytes' NPY production. We found that RIP140 expression was dramatically reduced in macrophages within the ventromedial hypothalamus (VMH) and the cingulate cortex of MΦRIPKD mice. These animals exhibited increased anxiety- and depressive-like behaviors. VMH-targeted RIP140 re-expression in MΦRIPKD mice reversed its depressive- but not its anxiety-like phenotype. Analysis of specific neurochemical changes revealed reduced astrocytic-NPY expression within the hypothalamus of MΦRIPKD mice, and in vitro analysis confirmed that conditioned medium of RIP140-silnenced macrophage culture could no longer stimulate NPY production from astrocytes. The current study revealed an emotional regulatory function of macrophage-derived RIP140 in the VMH, and secondary dysregulation of NPY within hypothalamic astrocyte population, which might be associated with the observed behavioral phenotype of MΦRIPKD mice. This study highlights RIP140 as a novel target for the development of potential therapeutic and intervention strategies for emotional regulation disorders.

Fusion of bolaamphiphile micelles: a method to prepare stable supported biomimetic membranes.

Supported biomimetic membranes (SBMs) on solid substrates have been commonly prepared from vesicle-forming double-tail lipids, such as zwitterionic phospholipids, using the method of vesicle fusion. Here we report on the preparation of SBMs on silica surfaces via a similar process of "micelle fusion" from a cationic single-tail bolaamphiphile GLH-20 that forms spherical and elongated thread-like micelles in solution. We demonstrate that, in contrast to zwitterionic phospholipids, GLH-20 self-assembles into a stable contiguous SBM at both low and high ionic strengths. The cationic charge of GLH-20 promotes the formation of a stable SBM through enhanced double-layer interactions with the negatively charged silica surface. It is also shown that spinach aquaporin PM-28 was successfully incorporated within bolaamphiphile SBM in a manner similar to SBMs prepared by vesicle/proteoliposome fusion; thereby the inherent curvature of the micelle surface does not inhibit protein reconstitution. The results suggest that SBMs based on charged bolaamphiphiles might be an attractive platform for applications such as water purification and biosensors, where the stability and low defect rate of SBMs in diverse conditions are crucial for achieving desired performance.

p53 in mitochondria enhances the accuracy of DNA synthesis.

Mitochondrial localization of p53 was observed in stressed and unstressed cells. p53 is involved in DNA repair and apoptosis. It exerts physical and functional interactions with mitochondrial DNA and DNA polymerase gamma (pol gamma). The functional cooperation of p53 and pol gamma during DNA synthesis was examined in the mitochondrial fraction of p53-null H1299 cells, as the source of pol gamma. The results show that p53 may affect the accuracy of DNA synthesis in mitochondria: (1) the excision of a misincorporated nucleotide increases in the presence of (a) recombinant wild-type p53 (wtp53); (b) cytoplasmic fraction of LCC2 cells expressing endogenous wtp53 (but not specifically pre-depleted fraction); (c) cytoplasmic extract of H1299 cells overexpressing wtp53, but not exonuclease-deficient mutant p53-R175H. (2) Mitochondrial extracts of HCT116(p53+/+) cells display higher exonuclease activity compared with that of HCT116(p53-/-) cells. Addition of exogenous p53 complements the HCT116(p53-/-) mitochondrial extract mispair excision. Furthermore, the misincorporation was lower in the mitochondrial fraction of HCT116(p53+/+) cells as compared with that of HCT116(p53-/-) cells. (3) Irradiation-induced mitochondrial translocation of endogenous p53 in HCT116(p53+/+) cells correlates with the enhancement of error-correction activities. Taken together, the data suggest that p53 in mitochondria may be a component of an error-repair pathway and serve as guardian of the mitochondrial genome. The function of p53 in DNA repair and apoptosis is discussed.

Antidepressive-like effects of rapamycin in animal models: Implications for mTOR inhibition as a new target for treatment of affective disorders.

Lithium, the prototypic mood stabilizer, was recently demonstrated to enhance autophagy in cells. Recent hypotheses regarding the source of therapeutic effects of lithium as well as other mood stabilizers and antidepressants suggest that they may stem from increased neuroprotection, cellular plasticity and resilience. Hence it is clearly a possibility that enhanced autophagy may be involved in the therapeutic action by contributing to increased cellular resilience. A well-documented mechanism to induce autophagy is by inhibition of mTOR, a negative modulator of autophagy and rapamycin (sirolimus) is a commonly used inhibitor of mTOR. Accordingly, the present study was designed to evaluate the effects of rapamycin in animal models of antidepressant activity. A dose-response experiment in the mice forced swim test was performed and followed by additional testing of mice and rats in an open field, the forced swim test and the tail suspension test. Results show that sub-chronic, but not acute, administration of rapamycin doses of 10mg/kg and above, have an antidepressant-like effect in both mice and rats and in both the forced swim and the tail suspension tests with no effects on the amount or distribution of activity in the open field. Whereas it is tempting to conclude that the antidepressant-like effects are related to mTOR inhibition, they may also be the consequences of interactions with other intracellular pathways. Additional studies are now planned to further explore the behavioral range of rapamycin's effects as well as the biological mechanisms underlying these effects.

Synthesis of novel cationic bolaamphiphiles from vernonia oil and their aggregated structures.

The present study describes the synthesis of a novel class of vesicle-forming bolaamphiphiles with choline ester head groups. These bolaamphiphiles were derived from vernonia oil, whose main constituent is vernolic acid, a fatty acid with a unique combination of epoxy, carboxy and unsaturated double bonds. A series of bolaamphiphiles containing amido or ester groups within the hydrophobic domain were synthesized from N,N'-alkylenebis (vernolamides) and alpha,omega-alkylene divernolate ester in a two-stage synthesis comprising opening of the epoxy ring with chloroacetic acid, followed by quaternization with N,N-dimethylaminoethyl acetate to form choline ester head groups. The products were characterized by FT-IR, (1)H and (13)C NMR, and ESI-MS. Vesicles prepared from these bolaamphiphiles have the potential to serve as a targeted drug delivery systems with selective decapsulation in the presence of the enzyme acetylcholine esterase, resulting in site-specific release of the drug.

Novel cationic amphiphilic derivatives from vernonia oil: synthesis and self-aggregation into bilayer vesicles, nanoparticles, and DNA complexants.

Self-assembling nanostructures were prepared from novel cationic amphiphilic compounds synthesized from vernonia oil, a natural epoxydized triglyceride. The presence of a 12,13-epoxy group on the C18 unsaturated fatty acid, vernolic acid, which is the main constituent of vernonia oil, permitted the synthesis of novel amphiphilic derivatives with a hydrogen-bonding hydroxyl and a cationic headgroup moiety on adjacent carbon atoms. The amphiphiles were prepared in a two-stage synthesis that comprised opening of the epoxy groups with a haloacetic acid, followed by quaternization of the halo group with a tertiary amine containing a C12 aliphatic chain. Intact vernonia oil as the starting material gave a triple-headed cationic amphiphile, containing three vernolic acid derived moieties connected through a glycerol backbone. A single-headed amphiphile with two alkyl chains and a single quaternary ammonium headgroup was synthesized from the methyl ester of vernolic acid as the starting material. The triple-headed derivative could form nonencapsulating structures. Cholesterol was required in the formulation (1:1) to make spherical vesicles that could encapsulate a water-soluble marker. The single-headed derivative, however, formed spherical encapsulating vesicles without cholesterol. TEM, NMR, and FT-IR were used to characterize the vesicles, and molecular structure vs morphology relationships were postulated on the basis of these data. The triple-headed amphiphile also formed a DNA complex that was highly resistant to hydrolysis by DNase. This amphiphile-DNA complex was used as vector for gene transfer in cell culture demonstrating efficient DNA transfection.

Response to radioimmunotherapy correlates with tumor pO2 measured by EPR oximetry in human tumor xenografts.

The efficacy of radiation treatment depends upon local oxygen concentration. We postulated that the variability in responsiveness of tumor xenografts to a fixed dose of radioimmunotherapy might be related to the tumor pO2 at the time that radioimmunotherapy was administered. We evaluated the growth of xenografts of CALU-3 tumors, a non-small cell lung carcinoma, in response to an 8.9-MBq dose of 131I-RS-7-anti-EGP-1 and correlated tumor growth rate with initial tumor pO2 measured by EPR oximetry. The greatest growth delay in response to radioimmunotherapy had the highest initial pO2, and the fastest-growing tumors had the lowest initial pO2. We then determined the dynamic effect of radioimmunotherapy on tumor pO2 by serial measurements of pO2 for 35 days after radioimmunotherapy. This information could be important for ascertaining the likelihood that a tumor will respond to additional doses as part of a multiple dose scheme. Serial tumor pO2 measurements may help identify a window of opportunity when the surviving tumor regions will be responsive to a second round of radioimmunotherapy or a second therapeutic modality such as chemotherapy or an anti-vascular agent. After radioimmunotherapy, there was an increase in tumor pO2 followed by a decrease below initial levels in most mice. Thus defined times may exist when a tumor is more or less radiosensitive after radioimmunotherapy.

Myocardial oxygen tension in isolated erythrocyte-perfused rat hearts and comparison with crystalloid media.

The isolated heart, typically perfused with crystalloid media equilibrated with >/=95% O2 to ensure adequate myocardial oxygen tension, is commonly used to study cardiac function. When hemoglobin is available for oxygen transport, equilibration with 21% O2 is considered adequate to meet metabolic demands. This study presents the measurement of myocardial pO2 in isolated hearts perfused with an erythrocyte suspension. Baseline myocardial pO2 in erythrocyte-perfused hearts was 16.4+/-3.5 mmHg (mean+/-s.e.). When compared to previous measurements of myocardial pO2 in isolated hearts perfused with crystalloid media, the use of erythrocyte suspensions resulted in a 10-fold lower level of myocardial pO2, while avoiding very low and high values. The standard use of 95% oxygen with crystalloid results in myocardial levels of oxygen far above those usually found in the presence of hemoglobin and room air.

Myocardial oxygen tension and capillary density in the isolated perfused rat heart during pharmacological intervention.

Oxygen is essential for normal cardiac function and plays an important role in cardiac regulation. Electron paramagnetic resonance (EPR) oximetry appears to have some significant advantages for measuring oxygen tension (pO2) in the beating heart. This study presents the serial measurement of myocardial pO2 by EPR oximetry in the isolated crystalloid perfused heart during treatment with different cardioactive drugs: dobutamine, metoprolol, verapamil, vasopressin, and N omega-Nitro-L-Arginine Methyl Ester (L-NAME). Baseline myocardial pO2 was 176 +/- 14 mmHg (mean +/- S.E.). Myocardial capillary density in the intact contracting heart was calculated to be 2300 +/- 100 mm-2, using local myocardial pO2 and a cylindrical model for oxygen diffusion in tissue. Each drug had characteristic effects on myocardial pO2, myocardial oxygen consumption (MVO2), and capillary density. Metoprolol and verapamil increased myocardial pO2 by 51% and 18%, respectively, dobutamine decreased myocardial pO2 by 84% while vasopressin and L-NAME had no significant effect on myocardial pO2. Metoprolol and verpamil decreased MVO2 by 9% and 56%, respectively, while dobutamine increased MVO2 by 59%. A quantitative comparison of effects on the capillary bed based on changes in myocardial pO2 and MVO2 was made. Metoprolol and verapamil had opposite effects on the capillary bed. Verapamil decreased myocardial capillary density by 39%, while capillary density increased by 10% (n.s.) with metoprolol. Data following perfusion without drug is also presented. We conclude that: 1) The application of EPR oximetry with LiPc provides dynamic evaluation of local myocardial pO2 in the contracting heart. 2) Using a cylindrical model of oxygen delivery and diffusion in tissue, these data may be used to describe the changes of capillary density during pharmacological interventions.

[Mathematical model of interphase cell death. Biophysical justification and generalization]. / Matematicheskaia model' interfaznoi gibeli kletok. Biofizicheskoe opravdanie i obobshchenie.

The authors propose a biophysical justification of a radiation-induced injury and interphase death of cells. The injury to certain units of the microtrabecular network and cytoskeleton is considered to be a primary biological effect of radiation on cells. The role of these structural changes in the development of the specific radiation response is discussed. It is found possible to describe formally, by the defined parameters of the proposed model, the survival curves for not only interphase but also reproductive cell death.

[Structural damages and DNA synthesis in bone marrow and peripheral blood cells in myelodepression induced by cytostatic preparations]. / Strukturnye povrezhdeniia i sintez DNK v kletkakh kostnogo mozga i perifericheskoi krovi pri mielodepressii, vyzvannoi tsitostaticheskimi preparatami.

Some structural and functional indices of the genome state of rat myelopoietic cells after cytostatic ingestion are studied by the immunofluorescent method and by 3H-thymidine incorporation. It is shown that administration of cyclophosphamide causes structural and functional damages of hemopoietic cells. It is suggested that the intensity of repair potentials is a leading factor in restoration of depressed hemopoiesis.

[The levels of occupational irradiation of medical radiologists in the USSR from 1981 data on centralized individual dosimetric control]. / Urovni professional'nogo oblucheniia meditsinskikh radiologov USSR po dannym tsentralizovannogo individual'nogo dozimetricheskogo kontrolia za 1981 g.

By the 1981 centralized individual dosimetric control data using film dosimeters IFKU-1 the summary dose of medical radiologists in the Ukraine was 223 man-cSv X year-1. The mean annual doses in different occupational groups of medical radiologists varied from 0.07 to 0.60 cSv X year-1 and were in accord with the data available to the UN Scientific Committee on Atomic Radiation Effects concerning the levels of irradiation in similar professions in France, Canada and Austria in the period of 1974 to 1975. Persons in charge of the storage of radioactive substances are referred to high risk groups by the level of a mean annual dose (0.60 cSv X year-1). The distribution of irradiation annual doses of medical radiologists in the Ukraine was well approximated by Weibull function within the dose range of 0-1.1 cSv X year-1. This dose range accounts for 98.4% of all the cases. 1.6% of the persons received annual doses within the range of 1.1-3.5 per year-1, and their summary dose was 53.5 man-cSv X year-1. Basing on the data obtained a conclusion has been made that an increase in the frequency of stochastic effects in Ukrainian medical radiologists at the expense of occupational irradiation in 1981 is not to be expected.

[Possibility of biological indication of radiation injury from the blood levels of deoxynucleosides and deoxynucleotides in combined radiation-mechanical injuries]. / Vozmozhnost' biologicheskoi indikatsii luchevogo porazheniia po soderzhaniiu dezoksinukleozidov i dezoksinukleotidov v krovi pri radiatsionno-mekhanicheskom porazhenii.

A study was made of the dependence of a total content of deoxynucleosides and deoxynucleotides in blood serum and blood clot leukocytes upon radiation dose and time lapsed after radiation- and radiation-mechanical affection. It was established that after radiation-mechanical affection this dependence was different from that observed after the effect of radiation alone. From the analysis of the data obtained it was inferred that deoxynucleosides and deoxynucleotides could be used for biological indication of radiation damage in conditions of radiation-mechanical affection.