Antisense-mediated isoform switching of steroid receptor coactivator-1 in the central nucleus of the amygdala of the mouse brain

Background

Antisense oligonucleotide (AON)-mediated exon skipping is a powerful tool to manipulate gene expression. In the present study we investigated the potential of exon skipping by local injection in the central nucleus of the amygdala (CeA) of the mouse brain. As proof of principle we targeted the splicing of steroid receptor coactivator-1 (SRC-1), a protein involved in nuclear receptor function. This nuclear receptor coregulator exists in two splice variants (SRC-1a and SRC-1e) which display differential distribution and opposing activities in the brain, and whose mRNAs differ in a single SRC-1e specific exon.

Methods

For proof of principle of feasibility, we used immunofluorescent stainings to study uptake by different cell types, translocation to the nucleus and potential immunostimulatory effects at different time points after a local injection in the CeA of the mouse brain of a control AON targeting human dystrophin with no targets in the murine brain. To evaluate efficacy we designed an AON targeting the SRC-1e-specific exon and with qPCR analysis we measured the expression ratio of the two splice variants.

Results

We found that AONs were taken up by corticotropin releasing hormone expressing neurons and other cells in the CeA, and translocated into the cell nucleus. Immune responses after AON injection were comparable to those after sterile saline injection. A successful shift of the naturally occurring SRC-1a:SRC-1e expression ratio in favor of SRC-1a was observed, without changes in total SRC-1 expression.

Conclusions

We provide a proof of concept for local neuropharmacological use of exon skipping by manipulating the expression ratio of the two splice variants of SRC-1, which may be used to study nuclear receptor function in specific brain circuits. We established that exon skipping after local injection in the brain is a versatile and useful tool for the manipulation of splice variants for numerous genes that are relevant for brain function.     

Polarization‐angle dependence of photoluminescence intensity of ordered GaInP2 layers: observation of polarization memory

We compare measured and calculated polarization‐angle dependencies of the intensity of the photoluminescence emission from MOVPE‐grown GaInP₂ layers with different ordering parameters. We measured the polarization‐angle dependencies of the emission propagating along the [001], [110] and [1 0] directions at room temperature. Symmetry considerations were used to calculate the dependence of the relative intensity of the PL emission which was linearly polarized along different directions and to estimate the value of the valence‐band splitting by fitting the measured dependencies with calculated curves. An intriguing influence of the polarization of the exciting beam on the relative amount of the polarized PL emission was observed in the emission from the (110) plane. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Enantioselective Iridium‐Catalyzed Allylation of Acetylenic Ketones via 2‐Propanol‐Mediated Reductive Coupling of Allyl Acetate: C14‐C23 of Pladienolide D

Highly enantioselective catalytic reductive coupling of allyl acetate with acetylenic ketones occurs in a chemoselective manner in the presence of aliphatic or aromatic ketones. This method was used to construct C14‐C23 of pladienolide D in half the steps previously required.     

Novel 4-azaandrostenes as prostate cancer cell growth inhibitors: Synthesis,antiproliferative effects,and molecular docking studies

In this study, synthesis, structural characterization, molecular docking studies, and antiproliferative effects in four different cell lines of several novel 16-arylidene-4-azaandrost-5-ene compounds are reported. These compounds were prepared by oxidative cleavage of the enone system of androstenedione followed by an azacyclization reaction and an aldol condensation with various aldehydes at C16. In the androgen-dependent LNCaP cells, the most relevant antiproliferative effects were observed with the 16-phenyl, 16-p-tolyl, and 16-p-nitrophenyl derivatives. Compound 16E-[(4-methylphenyl)methylidene]-4-azaandrost-5-ene-3,17-dione was the most potent in these cells (IC₅₀ = 28.28 μM), having lower antiproliferative effects in the androgen-independent PC-3 cells (IC₅₀ = 45.31 μM). In addition, an interesting selectivity toward cancer cell lines was found for all compounds because a generally low cytotoxicity was detected in healthy human fibroblasts. Furthermore, the 16-p-tolylazaandrostene steroid induced a reduction of viability in LNCaP cells similar to that observed with finasteride, a clinically used 5α-reductase inhibitor. Moreover, molecular docking studies predicted that these 4-azaandrostene derivatives can interact with 5β-reductase, which has a high level of similarity to 5α-reductase enzyme, and with other common targets of steroidal drugs, particularly the enzyme 17α-hydroxylase/17,20-lyase.     

New multifunctional heterobinuclear palladium (II) complexes based on organometallic dithiocarbazate ligands

In the research of new compounds with multifunctional applications, heterobinuclear palladium (II) complexes based on organometallic dithiocarbazates (DTCZs) have been isolated. The organometallic DTCZ ligands of the general formula [{(η⁵-C₅H₄)-CH=NNHC(S)SCH₃}]MLn [MLn = Re (CO)₃ ( 2a ); Mn (CO)₃ ( 2b ); FeCp ( 2c )] were prepared by the reaction between formyl organometallic precursors ( 1a−c ) with S-methyldithiocarbazate. Subsequently, a two-step reaction of 2a−c with: (i) K₂[PdCl₄] and (ii) PPh₃ yielded heterobinuclear complexes [Pd{MLn(η⁵-C₅H₄)-CH=NNHC(S)SCH₃}–(Cl)(PPh₃)] [MLn = Re (CO)₃ ( 3a ); Mn (CO)₃ ( 3b ); FeCp ( 3c )]. All compounds were characterized by conventional spectroscopic techniques (infrared spectroscopy, nuclear magnetic resonance spectroscopy, mass spectrometry and elemental analysis). In addition, the molecular structures of 2a , 2c and 3c were determined by single-crystal X-ray diffraction. The new palladium (II) complexes ( 3a−c ) were evaluated as antiproliferative agents against non-small cell lung cancer cells (H1299 cells). Complexes 3a and 3b containing cyrhetrenyl- and cymantrenyl-DTCZ ligands, respectively, were more active than their ferrocenyl analogue 3c . The activity was associated with the electron-withdrawing properties of the (η⁵-C₅H₄)M (CO)₃ moieties and their better lipophilicity than that of the ferrocenyl analogue. In addition, we studied the capacity of metalloligands ( 2a−c ) and palladium (II) complexes ( 3a−c ) to remove methylene blue in water under UV–visible light irradiation. The results established that the complexes showed moderate efficiency and were less active than their corresponding free ligands.     

Synthesis of Na<Subscript>2</Subscript>Ti<Subscript>3</Subscript>O<Subscript>7</Subscript> nanoparticles by sonochemical method for solid state electrolyte applications

Na₂Ti₃O₇ ceramic materials have been widely used in sodium-ion battery applications with relative good results; however, there are still several studies that might be carried out in the improvement of the Na₂Ti₃O₇ properties and the overall batteries’ performance. In this direction, we used sonochemical method following a thermal treatment in order to synthetized pure phase Na₂Ti₃O₇ nanopowders. X-ray diffraction characterization revealed that Na₂Ti₃O₇ is the primary phase in nanopowders and ceramic sample; although, a high level of amorphization was observed in the sonicated nanopowder without heat treatment process. Nanopowder-prepared ceramic sample showed a crystallite size of 50 nm after sintering at 900 °C for 1 h. The specific surface area, pore volume, and pore size were obtained from the B.E.T. measurements, being 51 m² g^?1, 0.07 cm³ g^?1, and 55 Å, respectively. The capacitance values of the nanopowder-prepared ceramic sample were in the order of microfarad. The total energy of the system was used to determine relaxation time of the sample (τ ₀ = 31 ms).     

Thermoanalytical characterization of molybdenum-based catalytic materials

Thermoanalytical techniques, especially temperature-programmed reduction (TPR), were employed for the characterization of oxidic precursors of molybdenum-based catalysts, sulfides derived from them, and three thiomolybdate compounds, employed as models or precursors of hydrodesulfurization atalysts. Correlations were found between TPR data and the presence of single and mixed oxides of Mo and Ni, Co or Fe, as demonstrated by XRD. The same phases and the thiomolybdates were shown to be present in supported catalytic precursors. Differences between the reducibilities of the mixed oxides of Ni-Mo, Co-Mo and Fe-Mo are easily appreciated from TPR, including those of the - and - polymorphic modifications of NiMoO₄.Support from Venezuela's Consejo Nacional de Investigations Científicas y Tecnológicas (CONICIT) and the International Activities Program of the American Chemical Society is gratefully acknowledged. The use of the TPR/TPD 2900 instrument was made possible by a generous loan of Micromeritics. Special thanks to my students and coworkers, who co-authored the publications cited in the list of references.     

Self-diffusion in simple models: Systems with long-range jumps

We review some exact results for the motion of a tagged particle in simple models. Then, we study the density dependence of the self-diffusion coefficientD _N() in lattice systems with simple symmetric exclusion in which the particles can jump, with equal rates, to a set ofN neighboring sites. We obtain positive upper and lower bounds onF _N()=N{(1–)–[D_N()/D_N(0)]}/[(1–)]x for [0, 1]. Computer simulations for the square, triangular, and one-dimensional lattices suggest thatF _N becomes effectively independent ofN forN20.     

Electrocatalysis of oxygen reduction by lanthanum-strontium manganate

The electrocatalysis of the oxygen reduction reaction by lanthanum-strontium manganate La_0.5Sr_0.5MnO₃ (LSM) has been studied by cyclic voltammetry using the rotating ring-disc electrode technique (RRDE) in alkaline medium. From the ring-disc data and other kinetic parameters it was concluded that the oxygen reduction occurs by dissociative chemisorption at low overpotentials. At higher overpotentials, the formation of hydrogen peroxide (HO₂⁻ in this case) on the electrocatalyst has been observed. The apparent exchange current density for oxygen reduction on LSM has been found to be 2 × 10⁻⁷ A cm⁻², while the corresponding Tafel slope is 0.100 V per decade. The possible reaction mechanism for electroreduction of oxygen on this oxide catalyst has been discussed. Published in Russian in Elektrokhimiya, 2008, Vol. 44, No. 7, pp. 919–923. The text was submitted by the authors in English.     

Quantum monte carlo study of the energetics of small hydrogenated and fluoride lithium clusters

An investigation of the energetics of small lithium clusters doped either with a hydrogen or with a fluorine atom as a function of the number of lithium atoms using fixed‐node diffusion quantum Monte Carlo (DMC) simulation is reported. It is found that the binding energy (BE) for the doped clusters increases in absolute values leading to a more stable system than for the pure ones in excellent agreement with available experimental measurements. The BE increases for pure, remains almost constant for hydrogenated, and decreases rapidly toward the bulk lithium for the fluoride as a function of the number of lithium atoms in the clusters. The BE, dissociation energy as well as the second difference in energy display a pronounced odd–even oscillation with the number of lithium atoms. The electron correlation inverts the odd–even oscillation pattern for the doped in comparison with the pure clusters and has an impact of 29%–83% to the BE being higher in the pure cluster followed by the hydrogenated and then by the fluoride. The dissociation energy and the second difference in energy indicate that the doped cluster Li₃H is the most stable whereas among the pure ones the more stable are Li₂, Li₄, and Li₆. The electron correlation energy is crucial for the stabilization of Li₃H. © 2016 Wiley Periodicals, Inc.