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CAMP 2008 February 22- February 24 Irvine, California
(back row): Ivan Rodriguez-Pinto, Lauren Sanchez, Jennifer Guerrero, Santi Srijumnong, Melissa Padilla, Erin Jimenez, Dr. Carla Koehler
(front row): Geraldina Rodriguez, Yolanda Tinajero, Michelle Crespo
(not pictured): Ben Lluncor, Michael Stone, Lindsay Williams
Conference Description
CAMP (The Louis Stokes California Alliance for Minority Participation) is a prime University of California initiative to diversify the student population and the future faculty, supported in part by a grant from the National Science Foundation. CAMP represents a system-wide community of UC faculty, program staff, and students working toward a set of shared goals, including not only B.S. degree completion but continuation on to graduate school, completion of the Ph.D., and entry into academic and professional careers in science and engineering. The primary goal of the nine UC campus partners (Berkeley, Davis, Irvine, Los Angeles, Merced, Santa Barbara, Santa Cruz, San Diego and Riverside) is to significantly increase the number of B.S. degrees granted to underepresented minority students in STEM (science, technology, engineering, mathematics) majors at the University of California and to prepare these students competitively for the nation's top graduate schools. This collective effort has contributed to a 84% increase in B.S. degrees granted by UC from the baseline year (1990-91), for a total of 12,396 bachelor's degrees awarded to date to underrepresented minorities by UC (as of 2006). CAMP emphasizes the importance of faculty mentored research experiences, collaborative learning experiences, presentation at research conferences and preparation for advanced degrees.
CAMP 2008 UCLA Award Winners
left to right: Melissa Padilla, Erin Jimenez and Ivan Rodriguez-Pinto
not pictured: Ben Lluncor
Mr. Ben Lluncor
UCLA Undergraduate, Senior
Major: Chemical and Biomolecular Engineering
Awarded: "Outstanding Poster Presentation in Physical Science/Engineering"
Faculty Mentor: Dr. Harold Monbouquette
Mentor's Department: Chemical and Biomolecular Engineering
Title: ANALYSIS OF THE LIPID SYNTHESIS PATHWAYA IN A THERMOPHILIC ARCHAEON ARCHAEOGLOBUS FULGIUDSArchaea constitute a third domain of life, separate from Eukarya and Bacteria, due to their ability to thrive in extreme conditions such as high temperatures, pressures, salinity, and pH. Key to the survival of archaea and its maintenance of homeostasis is the unique isoprenoid bonding exhibited by membrane lipids. In the thermophilic archaeon Archaeoglobus fulgidus, the enzymes (S)-2,3-Di-O-geranlygeranlyglyceryl phosphate synthase (DGGGPS), encoded by gene AF0404, and (S)-3-O-geranylgeranylglyceryl phosphate synthase (GGGPS), encoded by gene AF0403, are involved in the biosynthesis of isoprenoid bound tetraether and diether archaeal membrane lipids. These enzymes were identified through gene homology with another thermophilic archaeon, Sulfolobus solfataricus. The enzymes further downstream in the archaeal lipid synthesis pathway have not been identified nor has their catalytic function been explained. In the hopes of elucidating the A. fulgidus lipid synthesis pathway, two pathway enzymes, GGGPS and DGGGPS, were expressed in E. coli. The genes AF0403 and AF0404 were placed in tandem into the expression vector pET15b under the T7 promoter. The genes were marked with an N terminus histidine tag. To date expression of AF0403, as GGGPS was detected by immunoblot, was achieved. DGGGPS was not detected on the immunoblot, indicating a lack of expression of AF0404. Ultimately, our goal will be to express the entire isoprenoid lipid biosynthesis pathway of A. fulgidus .
Ms. Erin Jimenez
UCLA Undergraduate, Junior
Major: Molecular, Cell, and Developmental Biology
Awarded: "Outstanding Poster Presentation in Biological/Life Sciences"Faculty Mentor: Dr. Carla Koehler
Mentor's Department: Chemistry and Biochemistry
Title: AKT LOCALIZES TO THE INTERMEMBRANE SPACE IN MAMMALIAN MITOCHONDRIARecent studies have identified new pathways in the mitochondrial intermembrane space (IMS), including an oxidative folding pathway for the import of proteins and phosphorylation-dependent signaling. We are investigating the kinase AKT (also known as Protein Kinase B), a major serine/threonine kinase regulated by extracellular and intracellular signaling pathways and capable of inducing pro-survival and proliferative effects. Substrates of AKT include a number of signaling proteins, such as transcription factors, apoptotic machinery, and components of glycogen metabolism. Previously, it was reported that a fraction of the total cellular AKT localizes to the mitochondria in tissue culture cells. We have shown that, though it is present in both mouse brain and liver tissue, AKT only localizes to mitochondria isolated from the brain. Furthermore, the fraction of AKT in the mouse brain mitochondria is active and localizes to the IMS. We also have data that suggest AKT may be loosely membrane-associated facing the IMS. This is in contrast to previously published data that suggests AKT localization to the mitochondrial membranes and matrix of tissue culture cells. We are currently investigating the mechanism of AKT import into the mitochondrion and the mitochondrial substrates and interacting proteins of AKT. This line of research will provide insight into AKT regulation and its cellular effects as well as a greater understanding of signaling pathways in the mitochondrial intermembrane space.
Ms. Melissa Padilla
UCLA Undergraduate, Senior
Major: Chemistry
Awarded: "Outstanding Oral Presentation in Physical Science/Engineering"
Faculty Mentor: Dr. Miguel A. Garcia-Garibay
Mentor's Department: Chemistry and Biochemistry
Title: TOWARDS MOLECULAR ANALOGUES OF MACROSCOPIC GYROSCOPESMacroscopic gyroscopes are devices used to measure changes in orientation based on the principle of conservation of angular momentum. The simplest model consists of a rotator whose center of mass lies on the spinning axis that is linked to a stator, which provides a rigid frame for the entire system. We are interested in preparing molecular analogs of gyroscopes, fine-tuning their rotational dynamics, and studying their physical properties, with the goal of applying the knowledge obtained to the development of molecular machines. We are synthesizing 2,2,5,5-tetrafluoro-bis(triphenylsilyl)bicyclo [2.2.2]octane a molecular analogue to macroscopic gyroscopes, with the intention of studying its dynamics in the solid state to determine if the introduction of a dipole allows for control in the solid state. The key step in this synthesis was fluorination of dimethyl 2,5-dioxobicyclo[2.2.2]octane-1,4-dicarboxylate (1) to dimethyl 2,2,5,5-tetrafluoro[2.2.2]bicyclooctane-1,4-dicarboxylate (2), (34% yield) using diethylamino sulfurtrifluoride (DAST).
Mr. Ivan Rodriguez-Pinto
UCLA Undergraduate, Sophomore
Major: Undeclared- Life Sciences
Awarded: "Outstanding Poster Presentation in
Biological/Life Sciences"Faculty Mentor: Dr. Mark A. Frye
Mentor's Department: Physiological Science
Title: OLFACTORY MEDIATED SEARCH IN DROSOPHILA
Olfaction, the sense of smell, is crucial for an organism to track the volatile plumes emitted by sparse food resources. Behavioral responses to attractive odors are typically quite variable both within and between individuals. However, as far as we know, first-order and second-order olfactory neurons are activated by odors with little variation. The mechanisms by which flexible odor-tracking behaviors are regulated by robust olfactory sensory signals is not understood. Hungry flies were challenged to locate the source of a food odor tracking with a non-forced choice assay in freely mobile Drosophila melanogaster fruit flies. The time-course for locating the odor by wild-type flies is largely linear, hence providing a baseline to compare to genetic mutants. Recent studies show that genetic mutations in learning and memory elicit better optomotor responses to visual stimuli than wild-type flies by reducing the random exploratory component of fly behavior. Therefore, genes involved in behavioral plasticity could influence the time-course of odor search behavior by minimizing the random exploratory behavior of a hungry fly. Six mutants were tested, and whereas four showed no significant differences from wild-type flies, two localized a food odor source more slowly in a manner similar to genetically blind flies. These results are consistent with the idea that learning and memory pathways also participate in fast flexible sensory reflexes.
Additional UCLA Presentations:
Ms. Michelle Crespo
UCLA Undergraduate, Sophomore
Major: Molecular, Cell, and Developmental Biology
Ms. Yolanda Tinajero
UCLA Undergraduate, Sophomore
Major: Pre-Psychobiology
Faculty Mentor: Carlos Portera-Cailliau, M.D.- Ph.D.
Mentor's Department: Neurology
Title: CORRELATING ABNORMAL METABOTROPIC GLUTAMATE RECEPTOR SIGNALING TO SPINE DEFECTS IN FRAGILE X SYNDROME
Fragile X syndrome (FXS) is the most common inherited form of mental retardation. The prominent brain abnormality in individuals affected with FXS, as well as mutant mice lacking the Fmr1 gene, is that neurons in the neocortex have abnormal dendritic spines. Spines are tiny appendages that protrude from dendritic processes of certain neurons and form synapses with other neurons. Spines in FXS are very long and tortuous and therefore resemble dendritic filopodia, which are precursors to spines during brain development. Fragile X mutant mice also exhibit abnormal metabotropic glutamate receptor (mGluR) signaling, which is normally involved in learning and memory. In order to investigate a link between mGluR signaling and the spine defects seen in FXS, we bath-applied DHPG (50 uM), a selective agonist of group I mGluR, to acute brain slices from somatosensory cortex of early postnatal mice. We subsequently used two-photon microscopy to image GFP-labeled dendritic spines of layer II/III pyramidal cells transfected using in utero electroporation. We quantified the length, density and dynamics of spines using custom analysis software. We find that bath application of DHPG leads to a 33% increase in the length of spines (baseline: 1.46 ± 0.12, N=4; DHPG: 1.93 ± 0.13, N=4; P=0.0323), reminiscent of what occurs in FXS. Our results support the hypothesis that an upregulation of the mGluR signaling cascade could contribute to the synaptic phenotype found in FXS.
Ms. Jennifer Guerrero
UCLA Undergraduate, Junior
Major: Chemical Engineering
Ms. Geraldina Rodriguez
UCLA Undergraduate, Junior
Major: Biology
Faculty Mentor: Yi Tang, Ph.D.
Mentor's Department: Department Chemical and Biomolecular Engineering
Title: IMPROVING THE WHOLE CELL BOICATALYTIC PROPERTIES THROUGH PROTEIN ENGINEERING OF LOVDSimvastatin, a cholesterol-lowering compound, is the main component of the top selling drug Zocor. Simvastatin has traditionally been produced through a tedious, complex chemical synthesis from the natural product lovastatin. Our lab has characterized an acyltransferase, LovD, that allows simvastatin to be synthesized in one step. Through fermentation, an Escherichia coli strain overexpressing LovD acts as a whole cell biocatalyst to convert the precursor monacolin J and the substrate DMB-SMMP to simvastatin. Although >98% conversion was obtained when using 25mM monacolin J and 32mM DMB-SMMP, higher substrate concentrations result in lower conversion to simvastatin. This low conversion is partly due to the low solubility (50% soluble) and low activity (k cat=0.6 min -1) of LovD. In this study we performed site-directed mutation of cysteine to alanine to observe if LovD would increase in solubility and activity without cysteine residues. Because disulfide bonds formed by the cysteines in LovD also present an obstacle during crystallization, we anticipate that changing cysteine to alanine will also speed up crystallization, thus helping us to identify the active sites in LovD. Here we report the characterization of nine LovD mutants, each with one cysteine converted to alanine. Seven of the nine mutants did not show increased solubility when compared to wild-type LovD and displayed a decrease in whole cell biocatalytic conversion. Mutations in LovD of the cysteine at position 40 and the cysteine at position 60 to alanine gave mutants with higher solubility than wild-type LovD and increased whole cell biocatalytic conversion by ~1.4 fold.
Faculty Mentor: Dr. C.S. Colwell
Mentor's Department: Department of Psychiatry
Title: CIRCADIAN DYSFUNCTION OF 3-NP INDUCED MOUSE MODELS OF HUNTINGTON’S DISEASEHuntington’s Disease (HD) patients exhibit severe disturbances in their daily sleep/wake cycle. They have lower daytime and higher nighttime activity. They also have less st able and more fragmented activity and rest patterns. Here we explore and examine if there are similar dysfunctions in the circadian regulation of pharmacologically induced mouse models of HD. Wild type mice were treated with the mitochondrial toxin 3-Nitropropionic Acid (3-NP). 3-NP induces cellular and behavioral symptoms similar to those described in HD patients, including selective cell death within the neostriatum and motor dysfunction. Circadian behavior was evaluated by recording wheel running activity of individual mice. After synchronizing to a normal Light/Dark cycle, animals were exposed to 2-3 weeks of continual darkness and wheel running activity was monitored. Our expectation is that drug-treated mice will be un able to properly synchronize their circadian clock to their environment, and will exhibit a deterioration in their circadian rhythms characterized by unst able and fragmented wheel running activity, with an increase in daytime activity and a decrease in their nocturnal activity. Ultimately, this line of research will allow us to explore new approaches to disease management and treatment strategies to counteract circadian dysfunction in HD and improve the quality of life for both patients and care givers.
Ms. Lauren Sanchez
UCLA Undergraduate, Senior
Major: Molecular, Cell and Developmental Biology
Mentor: Dr. Luisa Iruela-Arispe
Mentor's Department: Molecular, Cell, and Developmental Biology
Title: CHARACTERIZATION OF A PROGESTERONE RECEPTOR LACZ REPORTER MOUSE MODELThe incidence of cardiovascular disease in women increases after menopause. The female hormones estrogen and progesterone are thus thought to confer cardioprotective effects onto pre-menopausal women. Progestins, synthesized forms of progesterone, are widely prescribed to menopausal women through hormone replacement therapy (HRT). In the past decade, however, progestin-containing HRT and contraceptives have been associated with an increased risk for heart disease. Work from our laboratory has linked the over-expression of the progesterone receptor (PR) with an increase in vascular permeability, an effect that may contribute to the onset of cardiovascular disease. To better understand the link between PR expression and the vasculature, we have generated a PRLacZ mouse model, in which the reporter gene lacZ is driven by both endogenous PR isoform promoters. LacZ expression analysis in PRLacZ heterozygote mice has revealed PR promoter activity in the fallopian tubes and follicular cells of the ovary and in the uterus. These results are consistent with PR expression previously described in mouse models of historical PR expression, validating this mouse as an accurate model of PR expression. PR promoter activity was noted in the vasculature in the uterus, but only after treatment with a hormone regimen, indicating that at basal, physiological levels of hormone, vascular expression of PR is not sufficient to elicit visibly significant lacZ expression. With the PRLacZ reporter mouse model we will be able to gain new insight on cell-specific effects of PR on the vasculature as well as other understudied tissues.
Mr. Santi Srijumnong
UCLA Undergraduate, Junior
Major: Molecular, Cell and Developmental Biology
Faculty Mentor: Steven Claypool, Ph.D. Mentor's Department: Chemistry and Biochemistry Title: DEFINING THE MECHANISM FOR THE LOSS-OF-FUNCTION FOR TAFAZZIN MUTANTSBarth Syndrome (BTHS) is caused by mutations of tafazzin (Taz1p), an enzyme involved in the series of deacylation:reacylation cycles of cardiolipin. To assess the effects of mutation of Taz1p on function, four uncharacterized taffazin BTHS mutants, A88E, A88R, S140R and L148H, were expressed in a yeast strain harboring a deletion in the endogenous TAZ1 gene (∆taz1). All four were found to be expressed at significantly lower levels than ∆taz1 yeast transformed with wild type tafazzin. Despite the reduced expression levels, the S140R and L148H mutants still resided exclusively to the mitochondrion and localized to the mitochondrial intermembrane space, revealed by subcellular fractionation and submitochondrial localization studies. To investigate whether the reduced expression was due to proteolytic degradation by mitochondrial proteases, the four mutants were expressed in yeast that lacked endogenous Taz1p and either Yme1p (Δtaz1/Δyme1), Yta12p (Δtaz1/Δyta12), or Oma1p (Δtaz1/Δoma1), three quality control mitochondrial proteases that reside in the mitochondrial inner membrane. Expression of the four BTHS mutants in these three strains revealed that in the absence of i-AAA protease, Yme1p, the expression level of each BTHS mutant was restored to levels, indistinguishable from wild type Taz1p. Strikingly, the restoration in protein level in the absence of Yme1p resulted in the partial rescue of normal cardiolipin and monolysocardiolipin levels in yeast expressing the A88R or L148H, but not the A88E or S140R, BTHS mutant tafazzin. Thus, Yme1p seems to mediate the degradation of certain BTHS mutant tafazzins, and prevention of this degradation, in some cases, may restore Taz1p function
Mr. Michael Stone
UCLA Undergraduate, Junior
Major: Pre-Psychobiology
Faculty Mentor: Dr. Reggie Edgerton
Mentor's Department: Physiological Science
Title: PHARMACOLOGICAL INTERVENTION AND NEUROREHABILITATION TO FACILITATE STEPPING IN SPINALLY INJURED ADULT RATS
Stepping was facilitated in spinally injured adult rats through the use of pharmacological intervention and neurorehabilitation. T he combination of epidural stimulation over specific lumbar or sacral segments and pharmacological activation of the serotonergic system with quipazine and/or 8-OHDPAT, a 5-HT 1A receptor agonist,can improve the stepping activity in rats with complete mid-thoracic spinal cord transaction. E pidural stimulation and administration of both quipazine and 8-OHDPAT was tested to see if it is more effective than epidural stimulation and quipazine alone to encourage stepping in spinal rats. Neurorehabilitation has also proven to be an effective measure in improving stepping abilities in spinally injured animals. We assessed how administration of quipazine, 8-OHDPAT, and the combination of both alter the characteristics of spinal reflexes at rest and during stepping. The animals were trained on a treadmill every other day for a duration of seven weeks. Each training session consisted of 15 minutes of hand-supported stepping. The data collected from animal testing was collected by means of kinematic recordings as well as electromyogram readouts. The results showed that 15 minutes of step training every other day for seven weeks was beneficial to improving stepping in spinally transected rats, along with pharmacological intervention. The animals with a combination of Quipazine and 8-OHDPAT and neurorehabilitation through step training stepped on an average of 30 minutes of quality stepping, as compared to the animals with no step training.
Faculty Mentor: Dr. William Yong
Mentor's Department: Pathology and Laboratory Medicine
Title:THE PREVALENCE OF FAVORABLE PTEN AND MGMT BIOMARKER STATUS IN GLIOBLASTOMA
Glioblastomas are genetically heterogeneous neoplasms and as a result they exhibit variable responses to therapy. Biomarkers that predict response to therapy include O6-methylguanine-DNA methyl transferase (MGMT) and phosphate and tensin homolog (PTEN). MGMT is a DNA repair enzyme and low levels of MGMT expression in tumors have been associated with a better response to Temazolamide, an alkylating agent. PTEN is a phosphate that modulates signaling pathways downstream from EGFR and loss of PTEN predicts a poor response to small molecule EGFR kinase inhibitors. The goal is to determine the prevalence of favorable PTEN and MGMT biomarkers in glioblastoma samples to predict response to therapy. The prevalence of a favorable biomarker status was assessed on 66 glioblastomas. The glioblastoma samples are placed in triplicate on a tissue microarray. Sections are then assayed for MGMT and PTEN by Immunohistochemistry. The extent of tumor cell staining is semi-quantitatively scored as percentages. PTEN loss greater than 25% is considered deficient as previously reported. By published criteria, MGMT immunostaining in less than 20% of tumor cells is considered favorable. 72.7% (48/66) of the tumors have a favorable PTEN status. 37.8% (25/66) have a favorable MGMT status. 27.3% (18/66) of the glioblastomas have both a favorable PTEN and MGMT status. Therefore, only a minority of patients with glioblastoma are predicted to have two available lines of therapy. To avoid use of possibly ineffective therapies, more work is needed to identify other predictive biomarkers for glioblastoma.
Ms. Lindsay Williams
UCLA Undergraduate, Junior
Major: Nursing
Faculty Mentor: Sally Maliski, PhD, RN
Mentor's Department: School of Nursing
Title: THE MEANING OF PROSTATE CANCER TREATMENT RELATED INCONTINENCE AND ERECTILE DYSFUNCTION IN AFRICAN-AMERICAN MEN
Prostate cancer is currently the most commonly diagnosed noncutaneous cancer in men in the United States. Following a diagnosis of, and treatment for prostate cancer, there is a tacit personal and social expectation that men will cope, adjust, and move on. This study focuses on African-American men specifically because prostate cancer attacks this population with higher incidence and more severity than any other group of men. The purpose of the study is to describe the impact of prostate cancer treatment- related incontinence and erectile dysfunction in African-American men. It is expected that the conclusions will differ from those of Caucasian males due to the influence of differences in socioeconomic, cultural, geographic, and educational factors. Patients were chosen from a program called IMPACT, Improving Access, Counseling and Treatment for Californians. This program is a state funded treatment program to serve the needs of low-income, and underinsured or uninsured men. This study included 35 men, all self-reported as African-American who have had or were currently having incontinence, erectile dysfunction, or both related to prostate cancer treatment. The patients were given two interviews, each three months apart, and the interviews were tape recorded and transcribed. Analysis of transcripts revealed a transitional process. The first step is normalizing, commonly by using age as an excuse for sexual dysfunction. The next stage is balancing hopeful waiting with acceptance. The next progression is reexamining life priorities and social roles. The last stage is a change in what it means to be a man.
Special thanks to Susan Walsh for symposium photos
