COURI Symposium Abstracts, Spring 2011

Effects of Influenza Viral Infection on the Cellular SUMOylation System

Joshua Ortiz^ et al. — Fri, 15 Apr 2011 07:46:49 PDT

The tendency of influenza strains to mutate rapidly, changing their antigenic makeup between consecutive seasons and allowing them to jump over the genetic barriers that limit their host range, imposes the risk for the influx of highly pathogenic viral strains into humans. Current available anti-influenza drugs target structural components of the virus and consequently, resistant viral strains arise due to point mutations that render the drugs ineffective. SUMOylation, the reversible post-translational attachment of a SUMO (Small Ubiquitin-like MOdifier) molecule to its target proteins, regulates numerous biological processes. Our studies have shown that some influenza viral proteins are SUMOylated during infection, raising the possibility that SUMOylation may regulate important events during influenza viral infections. To determine the role of SUMO on the viral replication cycle, we hypothesized that substantial change in the activity of the cellular SUMOylation system may slow or inhibit viral progression. To test this hypothesis, adenoviruses were used to introduce several dual expression constructs that efficiently exacerbate or inhibit the cellular SUMOylation system. Preliminary results indicate that down-regulating cellular SUMOylation lowers the amount of infectious viral particles produced during infection and reduces the expression of viral proteins. Further analyses will help characterize the roles of SUMO during viral infection and clarify its potential as a new target for the development of novel anti-influenza therapies.

Trypanosoma cruzi - Derived Sugar Epitopes - Synthesis and Immunology

Erika Y. Monroy^ et al. — Thu, 14 Apr 2011 07:27:06 PDT

The protozoan parasite Trypanosoma cruzi is the causative agent of Chagas disease. As of today no effective vaccine has been developed for it. Certain developmental stages of T.cruzi express cell surface oligosaccharides with terminal alpha-galactosyl and rhamnosyl residues, which are believed to be highly immunogenic in humans. The exact structures and sizes of these epitopes are still unknown. Our quest is to shine light on the chemical structures of immunogenic alpha-Gal and alpha-Rha containing mono-, di-, and trisaccharides that are conjugated to a keyhole limpet hemocyanin (KLH) carrier protein through a combination of chemical synthesis and immunological studies. The compounds synthesized were screened for their ability to be recognized by Chagasic antibodies in an enzyme-linked immunosorbent assay (ELISA). The best recognized sugar-KLH conjugates were used to immunize alpha-1,3 Gal T-KO mice, which do not express cell surface proteins with terminal alpha-galactosides, and are therefore a suitable model for humans. We have successfully synthesized and conjugated a library of nine saccharides with terminal alpha-galactosyl or rhamnosyl moieties, which elicit various levels of antibody production in mice. Upon challenge of the immunized mice with lethal doses of live T. cruzi, prolonged survival was observed when compared to the control group. The work presented here has implications for the development of a carbohydrate-based vaccine for Chagas disease.

Relation of Recent Seismicity (1988-Present) to the 1958 Huslia, Alaska Earthquake Sequence

Abigail Monreal^ et al. — Mon, 11 Apr 2011 12:57:28 PDT

We have examined how recent seismicity in the Huslia region of central Alaska is related to active faults and the 1958 earthquake sequence (with at least 3 events of magnitude >6). Most of this region is swampy lowland dominated by alluvial material deposited by the Koyukuk River, making surficial identification of active faults difficult. This portion of Alaska is also of interest because it appears to be a region in transition between the strike-slip faulting of the Salcha-Fairbanks-Minto Flats seismic zone and normal faulting of western Alaska (Norton Sound/Seward Peninsula). Researchers have suggested this change in the nature of faulting is due to the rotation of western Alaska away from central Alaska and the formation of a new microplate called the Bering Block. The eastern edge of the Bering Block is postulated to be located just east of Huslia. Our eventual goal is to combine information on recent seismicity, geology and geophysics with a careful analysis of the waveforms of the 1958 sequence in order to better understand the seismic hazards and tectonic processes of the area.

Effects of Cerium Oxide Nanoparticles on Glycine Max Grown in Hydroponics

Alyssa De La Rosa^ et al. — Mon, 11 Apr 2011 08:26:08 PDT

Cerium oxide nanoparticles (NPs) or nanoceria have a high level of UV absorption and antioxidant behavior, making them great candidates for sun screens, beauty products, and in treating cancer and glaucoma. The increased use of these NPs underscores the importance of understanding their environmental fate and toxicity. So far, information about nanoceria toxicity to plants is scarce. The objectives of this study are to determine the effect of CeO2 NPs on soybean (Glycine max) plant growth and monitor their uptake, deposition, and biotransformation. Soybean plants were treated for 14 days in a modified Hoagland solution containing varying concentrations of CeO₂ NPs (0, 500, 1000, 2000, and 4000 mg/L). Leaves, stems, and roots of the treated soybean plants were analyzed separately using ICP-OES and XAS. The ICP-OES results showed cerium concentrations in roots varying from 37068 - 74774 mg kg^-1. In stems and leaves there was a maximum cerium concentration of 3028 and 1048 mg kg^-1, respectively. XAS results suggest that soybeans absorb and store the nanoceria without any biotransformation. Increased growth and growth abnormalities in leaves were found in those plants treated with NPs. A high rate of translocation indicates promising use of soybeans in nanoceria phytoremediation.

Toxicity of TiO2 Nanoparticles in Cucumis Sativus

Fabiola Moreno-Olivas^ et al. — Sun, 10 Apr 2011 15:47:29 PDT

Nanoparticles (NPs) have a wide range of applications in medicine, electronics, catalysis, cosmetics, and pharmaceuticals. TiO2 NPs are very stable and can be transported and dispersed into aquatic environments. Several animal species have shown negative reaction to TiO2 NPs. However, little is known about their toxicity on plants, specially their possibility to enter the food chain via the crops utilized or subsequent production steps. We have studied the possible genotoxic effects of TiO2 NPs on cucumber (Cucumis sativus), a worldwide cultivated species that serves as food for insects and other animals in the food web. Seven-day old hydroponically grown cucumber plants were treated for 15 days with 21 nm TiO₂ NPs (Nippon Aerosil) dissolved in the Hoagland nutrient solution at concentrations of 500, 1000, 2000 and 4000 ppm. NPs suspensions were sonicated for 30 min in an ultrasonic homogenizer to avoid aggregation. Genomic DNA quantification was performed in root tips after seven days of treatment following standard DNA extraction procedures. Results showed that, compared to controls, plants treated at the highest TiO2 NP concentrations (2000 and 4000 mg/L) had a decrease in genomic DNA.

Two-Photon-Excited Tryptophan Fluorescence Microscopy for Leukocytes and Cancer Cells Imaging

Jesus A. Valdez^ et al. — Sun, 10 Apr 2011 15:27:57 PDT

Cancer screening and early diagnosis is an important yet controversial issue due to the safety and practicality of methods used. Our objective is to study the efficiency of an in vivo two-photon microscope developed in our laboratories to monitor cell inflammation. First, leukocytes were separated by subpopulation. The tryptophan fluorescence intensity level of each type of leukocyte was then quantified with two-photon microscopy, in their naïve and inflamed states, respectively. Finally the tryptophan fluorescence intensity of multiple myeloma cells was quantified and correlated to the resulting images. The cancerous tissue auto-fluorescence from NADH and FAD was also recorded as a control to determine the specificity of the technique. Comparison of the fluorescence of leukocytes and cancer cells has demonstrated the presence of tryptophan in different quantities per cell, thus offering the potential for distinguishing multiple myeloma cells from leukocytes in circulation and record multiple myeloma cell trafficking process. This is a significant advantage over spectroscopy techniques for safe in vivo imaging of cancer screening, since it can be applied without the need for labeling. It is potentially applicable for tracking leukocytes and monitoring inflammatory cellular reactions in humans.

Bis( N, N-dipheny-3-pyridineamine) Tungsten Complex as Molecular Gyroscope

Verenice Ramirez^ et al. — Sun, 10 Apr 2011 14:30:43 PDT

In recent years, the interest in molecular machines has increased based on inspiration from macroscopic machines, such as gyroscopes applied in racecar engines and arrays of gyroscopes in automatic pilot functions. The same concept has been taken down to the nanoscopic level as molecular machines in solution like bevel gears and turnstiles, but for application use they must be in the solid state. Gyroscope molecules can exhibit fast rotation and the aim is to design free rotation in the crystal lattice that maintains volume conserving motion. Bis(N,N-diphenyl-3-pyridinamine) tungsten complex was prepared by irradiation of tungsten hexacarbonyl in the presence of THF and the free ligand N,N-diphenyl-3-pyridinamine. It was partially characterized from preliminary data (Infrared spectroscopy, ¹H and ¹³C NMR, and mass spectroscopy). The dipyridine and tripyridyl amines are currently being synthesized for formation of the di- and tri-rotor complexes. Similar ligands are being synthesized with a single pyridine and with two and three pyridyl groups.

Modeling of Solvent Electrostatic Effects

Jose A. Rodriguez Lopez^ et al. — Sun, 10 Apr 2011 13:48:52 PDT

The photo-induced charge-transfer process is fundamental to light harvesting in organic donor-acceptor systems. The process is often enhanced when the system is in a polar solvent. The aim of this project is to create a simple, discrete model containing dipoles that can explain the solvent effects, where only dipole-dipole solvent interaction is considered. The goal is to reduce computational complexities and cost. We create a grid of solvents (water) which mimic the solvent’s density; and put one solute (a light-harvesting triad of β-carotene, porphyrin, and C60) at the grid’s center, keeping the grid points 1.5 times the Van der Waal radii away from the solute atoms. The solute’s partial charges and the solvents dipoles create an electrostatic field which determines the solvent configurations. Using Monte-Carlo method and classical electrostatics at a given temperature we obtain the lowest energy and the average configuration of the grid. Our calculations are performed at T=300K and T=10K for the ground and charge-transfer excited states of the solute. The field due to the solvents can be used in quantum mechanical calculations to determine the solvent effects. Future work will include the induced dipole moments of the solvents into the calculation and also use a variable grid.

Using Gravitational and Magnetic Data to Understand Interactions Between Active Seismic Zones Within the Interior of Alaska

Shane M. Schinagel^ et al. — Sun, 10 Apr 2011 12:20:54 PDT

Differences in rock density, along with changes in the orientation of the magnetic field, provide vital information about the tectonic environment within the interior of Alaska in a region where outcrop exposure is poor due to recent glacial and fluvial activity. Analysis of the gravity and magnetic field can help identify relationships between recent (1989-2008) and historic (pre-1971) seismicity and suspected strike-slip, reverse, and thrust faults within the region, as differences in density and magnetic properties of materials may be observed across fault zones. Our overall objective is to better understand the complicated interactions between the strike-slip Denali fault system and surrounding faults, especially how the 2002 M=7.9 Denali fault earthquake may have brought surrounding faults closer to failure.

Increasing Efficiency in Boundary Security with Wireless Sensor Networks and Geospatial Information Systems using Homology Theory

Luis Berumen^ et al. — Sun, 10 Apr 2011 12:08:48 PDT

As part of an institutional investigation, we attempt to address the challenges the US customs and Border protection agency faces in the El Paso region. Our research focuses on defining a system for the surveillance application, and the use of mathematical models employed to achieve a greater efficiency of such architecture. With the use of the defined system, we apply homology theory through the algebraic process of topology, to accomplish an independent coordinate-free based system, which covers the surveillance area, with lesser quantity of sensor nodes. Our architecture makes the use of an operating system for wireless sensor networks; TinyOS, a high-level programming language for interface; Java, data records management; MySQL, geospatial information systems; ArcGIS, and rich intranet application for interpretation; Silverlight. The combination of the determined technologies was chosen to form a novel approach to address security, compatibility, and increased efficiency.

Expression and Purification of Recombinant LEDGF/p75

Ivonne R. Reyes^ et al. — Sat, 09 Apr 2011 14:42:58 PDT

HIV infection requires the integration of a DNA copy of the viral genome into the host chromosome. The cellular protein LEDGF/p75 has an essential role in this process. Different cellular proteins interact with LEDGF/p75, but the significance of these interactions for HIV infection is unknown. To further characterize these protein interactions, we will use recombinant LEDGF/p75 wild type (WT) and mutants. LEDGF/p75 WT was PCR amplified and cloned N- terminally fused to glutathione S-transferase (GST). This expression plasmid was later used to generate deletion mutants targeting different LEDGF/p75 functional domains. These constructs were transformed into E. coli Rosetta. Optimal conditions for the expression, extraction and affinity purification of GST fusion proteins were experimentally determined. The main problem that we have encountered during the production of the recombinant LEDGF/p75 is protein stability. Conditions of the culture or the induction minimally improved the stability of the fusion proteins. We have observed that the C-terminal region of the protein is more stable than the full-length protein or the N-terminal region. Nevertheless we have been able to purify GST-LEDGF/p75 WT although a GST fused degradation product is still present in our preparation. We will attempt further purification of the recombinant protein through gel filtration.

Precipitation Accumulation Differentiations in El Paso, Texas and Surrounding Areas

Nessly Torres^ et al. — Sat, 09 Apr 2011 14:25:39 PDT

The city of El Paso is built around the Franklin Mountains thus splitting the metropolitan area into four ecologically distinct sections: northwest, west, northeast, and east. However, each segment differs in precipitation accumulation. The intent of this research is to compare current to previous rainfall accumulation data and uncover the factors that have influenced the levels of precipitation around the city over time. Additionally, rainfall accumulation and influencing factors are compared to those of surrounding cities (Las Cruces, NM, Ruidoso NM, Albuquerque, NM, Midland, TX, and Tucson, AZ). Precipitation information was collected using data from the National Weather Service and from Fire Stations. Results show that the geographical locations tested did not have more consistent rainfall than other geographical locations over time. The El Paso metropolitan area will benefit from this research by further understanding precipitation patterns, which will allow future storm water diversion engineering and storm water treatment from industrial contamination.

Structural Study of mCRY2: A Circadian Rhythm Regulator

Brenda L. Rodarte^ et al. — Sat, 09 Apr 2011 13:56:43 PDT

A circadian clock is a 24 hour biological rhythm that regulates physiological, psychological and behavioral processes in living organisms. Understanding the regulation mechanism of such circadian rhythms can have great impact in certain diseases such as sleeping disorders and cancers. There are many genes regulating circadian rhythms in different species. Cryptochromes (CRY) are photosensory receptors mediating light regulation of growth and development in certain species. Mouse cryptochrome protein mCRY2 has been found to encode a blue light photoreceptor and is important for mice circadian rhythm. The main goal of the project is to determine the atomic structure of mCRY2, via X-ray crystallography. The mCRY2 gene will be cloned into a vector (pET-DEST42) and expressed in bacterial E.Coli strain BL21 (DE3). Expressed protein will be purified using chromatography and other biochemistry methods. Purified protein will be used to screen to obtain crystals for X-ray diffraction. The mCRY2 gene has been isolated by polymerase chain reactions and is ready to be ligated into the vector. The atomic structure of mCRY2 obtained from this project will facilitate our understanding of its function and also allow prediction of its role in mammalian circadian clocks. Furthermore, the results will guide future mutagenesis and biochemistry studies.

Detecting Unmarked Graves using GPR at the Mescalero Apache Reservation

Stephanie Y. Chavez^ et al. — Sat, 09 Apr 2011 13:37:46 PDT

In Mescalero, New Mexico, on an Apache Indian Reservation, we were asked to survey the Mescalero Cemetery in order to locate unmarked graves. Back in the late 1800’s, proper documentation of graves was never made. As a result, what is thought to be a new potential burial site is discovered to be an old undocumented grave. Reservation officials have asked us to survey the cemetery and document exact locations of unmarked graves. To achieve this goal, we will use ground penetrating radar (GPR) and a differential global positioning system (DGPS). The collected data will be processed by using EKKO-Mapper and EKKO-View Deluxe. These data processing programs will allow us to view our collected data, edit noise out of the data, and enable us to view our surveyed area in Google Earth by applying DGPS points obtained during the survey. From the processed data, we will identify possible grave sites and inform the reservation officials of the findings. There are three cemeteries in the region and our initial study will only cover part of one of the cemeteries. This project could continue for many years and generate a number of research projects.

Characterization of Promoter Specific Effects Displayed by Beta-Catenin and FKBP52 in the Regulation of AR

Karen Olivares^ et al. — Sat, 09 Apr 2011 13:24:22 PDT

One of the most interesting topics in steroid hormone research is examining the influence of regulators of the steroid hormone signaling pathways. By identifying and understanding the relationship between these regulators on events of transcriptional regulation, receptor localization, and degradation events, we can target these regulators to enhance or decrease their influence on the steroid hormone receptors’ activities within the cell. Increased transcription by the Androgen Receptor has been implicated in several prostate cancer studies. Two proteins in particular, FKBP52 and β-Catenin, are of interest to our group, to examine for potential interaction in signaling cascades promoting prostate cancer. β-Catenin’s involvement in the Wnt signaling pathway appears to be important for understanding the development of prostate cancer, and increased levels of FKBP52 are implicated in prostate cancer. ß-Catenin and FKBP52 appear to coactivate AR in a synergistic fashion when transfected into FKBP52 knockout MEFs. We have found that ß-Catenin and FKBP52 synergize using the synthetic steroid hormone regulated MMTV promoter, but this synergism is maximized when the endogenous AR probasin promoter is used. The promoter specificity of this synergism suggests that ß-Catenin and FKBP52 exert their effects on AR signaling at the transcriptional level. We wish to explore other endogenous AR promoter reporters, as well, and have a better understanding of the relationship between these proteins.

Screening of Metal-Based Azole Derivatives Antiparasitic Activity on Trypanosoma cruzi and Leishmania major

Teresia A. Carreon^ et al. — Sat, 09 Apr 2011 12:54:54 PDT

The trypanosomatids Leishmania major and Trypanosoma cruzi are parasites that affect millions of people worldwide. Leishmaniasis is naturally transmitted via sandflies while T. cruzi is transmitted by kissing bugs. Due to immigration and deployment to endemic regions, lack of screening in blood banks and climatic changes these neglected diseases have become a growing health concern in the United States. The lack of vaccines to prevent/treat the diseases and the toxicity of current treatments supports the need for new drug treatments. Azole compounds inhibit the sterol synthesis pathway of these parasites, which has been validated as a drug target. T.cruzi epimastigote forms were analyzed using alamarBlue®. A luciferase assay was used with transgenic promastigotes (Friedlin clone V1) expressing firefly luciferase for L. major. The parasites were incubated 72 hr with the drugs. The most potent trypanocidal compounds were AM163 and AM161 showing 86% and 78% mortality at 468 nM; followed by AM160 and AM103 with 91% mortality at 937 nM. For L. major the most efficient derivates were AM162 and AM161, with 84% and 80% mortality using 243 nm. To determine the clearance of the parasite in infected cells, in vitro infectivity experiments using high content imaging are planned. The goal of the project is to find new treatments for Chagas’ disease and leishmaniasis.

Effects of Water Quality on Genetic Variation on the Brackish-water Rotifer Brachionus plicatilis

Kayla I. Hinson^ et al. — Sat, 09 Apr 2011 12:46:44 PDT

Impacts of water quality on the genetic structure of aquatic organisms have not been well characterized. Unfavorable conditions may result in loss of species diversity and/ or select for tolerant genotypes. We investigated whether aquatic pollutants affect the genetic diversity of the rotifer Brachionus plicatilis, common in saline systems. We predict that the genetic diversity of B. plicatilis will decrease with lower water quality. An urban population (Ascarate Lake, El Paso Co., TX) was compared with a non-impacted population (Figure 8 Lake, Bottomless Lakes, NM). Basic water chemistry parameters were measured along with heavy metals concentrations. Genetic variation is being determined by sequencing the mitochondrial COI, 16S rRNA genes and the nuclear non-coding ITS region. Water chemistry parameters for both lakes fell within the EPA freshwater chronic criteria except for conductivity, salinity, and TDS. Ascarate Lake exceeded criteria for several metals. Figure Eight Lake exceeded the criteria for one metal and will be used as the non-impacted site. Preliminary analyses of 16S rRNA genes showed no genetic variation among individuals from Ascarate Lake, however it was useful in phylogenetic analysis. Individuals from Figure Eight Lake are being cultured and determination of genetic variation within and between populations is underway.

Leptin Protects Dendritic Cells from Chemically-Induced Cell Death

Yadira Arellano^ et al. — Sat, 09 Apr 2011 12:23:17 PDT

Leptin is a pleiotropic adipokine that exerts its physiological effects by binding to its receptor, which is expressed in many immune cells including T cells, macrophages, and dendritic cells. Multidrug resistance-associated protein (MRP) is a transmembrane transporter commonly associated with cancer cells conferring resistance to chemotherapy. The purpose of this study is to determine if leptin supersedes the cytotoxic death signal in dendritic cells. We further hypothesize that the mechanism underlying leptin protection is a result of over expression of MRPs. To address this question, we examined the effect of leptin on monocytes treated with cytotoxic drugs in vitro. Bone marrow-derived dendritic cells (BM-DCs) and JAWSII were treated with camptothecin (CPT), plumbagin (PB8) or doxorubicin (Doxo) in the presence or absence of leptin. CPT, Doxo and PB8 are anticancer drugs that inhibit topoisomerase I, topoisomerase II and induce free radical formation respectively. Cell line viability was assessed via a colorimetric assay. Induction of cell death was measured by annexin V/propodium iodine staining. BMDCs generated from DB mice with a nonfunctional leptin receptor were used in response to camptothecin, leptin or a combination. The data demonstrates that leptin inhibits cell death upon treatment with cytotoxic agents.

Climate Related Changes in Chemical Characteristics of Arctic Tundra Ponds Over the Past 40 Years.

David A. Hernandez^ et al. — Sat, 09 Apr 2011 12:17:28 PDT

The Arctic tundra ponds at the International Biological Program (IBP) site in Barrow, AK were first studied in the 1970s and were re-visited in 2010. Recognizing modifications in the ponds’ structure and activity is critical to distinguishing possible climate-related impacts on Arctic freshwater ecosystems. The main objective of this project was to re-sample historical pond research sites in order to establish how the physical and chemical characteristics of the ponds have been altered over the past 40 years. Preliminary data from the same IBP ponds sampled in 2009-10 and the 1970’s demonstrate an increase of phosphorus and a decrease in nitrate concentrations over time. The increase in phosphorus may be present due to the greater proximity of the IBP sites to urban areas or release from thawing permafrost. Comparisons to other more isolated ponds in the region indicate that the IBP ponds are not nutrient enriched because of their location near the village of Barrow. These data support climate change and permafrost thaw as the principal cause of this nutrient enrichment. Results from this and further studies will lead to a better understanding of the implication of climate change on Arctic tundra pond ecosystems.

Are Elevated Nutrient Levels in Arctic Tundra Ponds Due to Permafrost Thawing?

Francisco R. Reyes Jr.^ et al. — Sat, 09 Apr 2011 12:11:30 PDT

Continued warming of the arctic tundra in northern Alaska can have important ecological implications for freshwater ecosystems. An increased active layer depth can lead to nutrient release from permafrost. Comparisons of water quality parameters from the 1970s and 2008-09 from tundra ponds in Barrow, Alaska indicated an increase in water column Total Phosphorus (TP), Soluble Reactive Phosphorus (SRP), Total Dissolved Phosphorus (TDP) and algal biomass (phytoplankton) over time. We designed an incubation experiment to look at nutrient release rates from permafrost and active layer cores under different warming scenarios. Although water column data have shown an increase in phosphorus species over the past 40 years, permafrost core incubations showed high concentrations of nitrogen species being released from sediment. In particular, ammonia concentrations were significantly higher in permafrost incubations compared to the active layer incubations. Understanding the release of nutrients from the permafrost can help delineate nutrient concentrations that will be added to arctic tundra pond ecosystems with warming.