The long-term goal of the LA CaTS Pilot Grants Program is to develop a critical mass of senior scientists and promising young investigators trained in translational research. Below are the projects and investigators supported through the LA CaTS Center Pilot Grants Program.
Metabolic Effects of Short Term Sugarcane Bagasse Supplementation
Daniel Hsia, Pennington Biomedical Research Center
Diets high in fiber have been shown to reduce the risk of type 2 diabetes and cardiovascular disease. However, the average American diet contains ~10 to 15 g of fiber per day and is well below the 20-35 g of fiber per day recommended by the Academy of Nutrition and Dietetics (formerly the American Dietetic Association). Therefore, there is a need to study methods of increasing dietary fiber intake as well as novel sources of dietary fiber. Sugarcane bagasse is the remaining fibrous material after sugarcane juice is extracted. Pre-clinical studies have shown attenuated weight gain, enhanced insulin sensitivity via HOMA-IR, lower ghrelin gene expression, and increased GLP-1 levels in mice fed a high fat diet plus sugarcane fiber compared to mice fed the same diet plus cellulose fiber. This 4 week double-blind placebo-controlled pilot study in obese, insulin-resistant adults aims to translate these results into humans. We hypothesize that subjects who consume food supplemented with sugarcane bagasse will have improved glucose tolerance and insulin sensitivity (via OGTT), less weight gain, increased satiety, higher GLP-1 levels, and lower ghrelin levels.
Evaluation of ACE2 as a Biomarker for Neurogenic Hypertension
Eric Lazartigues, LSU Health Sciences Center New Orleans
ACE2 activity is reduced in the central nervous system (CNS) during the development of experimental neurogenic hypertension. This could result from the enzyme being cleaved from the cell membrane through “shedding” by ADAM 17, also known as TNFα convertase. This “shedding” of ACE2 could lead to increased levels of soluble ACE2 within the CNS which is thought to be associated with hypertension and other cardiovascular diseases. Therefore, measurement of soluble ACE2 in the CNS could be used as a biomarker for developing neurogenic hypertension. We assessed ADAM 17 activity in the brain by measuring soluble ACE2 and TNFα in the cerebro‐spinal fluid of patients by ELISA and mass spectrometry. CSF samples were obtained from 30 patients divided in 3 groups: normotensive (n=15), hypertensive (n=4), and hypertensive controlled with medication (n=11). While Elisa lacked sensitivity, soluble levels of hACE2 could easily be detected by RAS‐Fingerprint™ in all patients. Increased ACE2 activity in the CSF was associated with hypertension. On the other hand, patients taking antihypertensive medications appear to show normalization of ACE2 levels in the CSF. In conclusion, soluble ACE2 activity in the CSF is correlated with high blood pressure and could be used as a biomarker of neurogenic hypertension.
Transcriptional Profiling of Gastritis Progression Using High Throughput Sequencing of Tissue MicroRNA
Jovanny Zabaleta, LSU Health Sciences Center New Orleans
Gastric cancer is one of the most common of all cancers and has one of the highest prevalence and mortality rates worldwide. More than 20,000 new cases of gastric cancer are expected in 2013, and more than 10,000 deaths will be attributed to the disease. Among all the risk factors, which include diet, age and ethnicity, infection with Helicobacter pylori (H. pylori) is the only irrefutable factor associated with the disease, especially in the intestinal form of gastric cancer. Because of this relationship, H. pylori is classified as a Type I carcinogen by the International Agency for Research in Cancer (IARC). A chronic inflammatory cascade from normal epithelia to non-atrophic gastritis (NAG), to multifocal atrophic gastritis (MAG), to intestinal metaplasia, dysplasia and cancer is initiated by the infection and can persist even after the eradication of H. pylori. Thus, determining the ideal therapeutic approach to delay or prevent the progression of inflammatory lesions to gastric cancer remains challenging. We have shown that single nucleotide polymorphisms (SNP) in cytokine genes are differentially associated with risk of advanced gastric lesions in African American and Caucasian individuals. However interesting, these are cross-sectional results and, thus, we are not able to explore gene profiles associated with the evolution of these gastric lesions. microRNA (miRNA) are small 18 - 24 nucleotide molecules known to interfere with both translation and transcription. Several profiles of miRNA have been associated with cancer risk but their role in disease evolution is still unknown. In this application we propose the innovative use of sequential biopsies from individuals with differential outcomes to evaluate the inflammatory lesion-to-malignancy cascade using high throughput sequencing. Our goal is to compare miRNA profiles in gastric biopsies at baseline and 12 years later to determine if there are specific gene sets, which can be associated with progression or regression of the disease.
Using Serum microRNAs as Biomarkers for Cognitive Impairment in HIV Patients
Francesca Peruzzi, LSU Health Sciences Center New Orleans
Human Immunodeficiency Virus (HIV)-infected individuals are at increased risk for developing depression and other neurocognitive disorders, but neurobiological mechanisms underlying mental deterioration in HIV-positive individuals remain unknown. Neurocognitive impairment and depression adversely impact HIV treatment adherence. Thus, identification of early markers of neurocognitive impairment could lead to interventions that improve psychosocial functioning and slow disease progression through improved treatment adherence.
MicroRNAs are short non-coding RNAs that regulate gene expression. microRNAs are key regulators of synaptic plasticity and brain development and, as such, could contribute to the etiopathology of neurocognitive disorders. In addition, microRNAs secreted into body fluids can serve as diagnostic and/or prognostic markers for a variety of diseases. Here, we present preliminary results of differentially regulated plasma microRNAs from 21 HIV-1 positive patients grouped on the basis of their neurocognitive status and/or symptoms of depression. Results indicate that plasma miRNAs may serve as useful biomarkers for HIV-associated neurocognitive disorders.
MicroRNAs as Prognostic Markers of Breast Cancer
Suresh Alahari, LSU Health Sciences Center New Orleans
Our hypothesis is that miR-27b and miR-23b function as oncogenes by suppressing the function of Nischarin and ST14 tumor suppressors (and possibly other unknown proteins as well), and thus miR-27b and miR-23b are key regulators and good prognostic markers of breast tumor growth and metastasis. We believe these microRNAs have similar prognostic importance as Her2/Neu in breast cancer. We will test our hypothesis by examining the prognostic importance of miR-27b and miR-23b in breast cancer patients. Here we will examine the expression levels of these two microRNAs in sera of breast cancer patients and controls. It is known that serum microRNAs can be diagnostic and/or prognostic markers for breast cancer. Moreover, blood sampling is minimally invasive and easy to obtain, and thus it is attractive to explore for potential biomarkers in blood. We will screen blood serum of 103 cancer patients and 103 controls, and this would reveal the prognostic role of these microRNAs in breast cancer.
Discovering the Role of Putative MicroRNAs in Prostate Tumorigenesis
Zakaria Abd-Elmageed, Tulane University
Prostate cancer (PC) is the most frequent cancer among older men. PSA is the most common diagnostic biomarker; however it has well known limitations. Microvesicles (MVs) are cell-derived extracellular bodies, which promote cell-cell communications. The identification of tissue- or disease-specific MVs miRNAs will enable the use of these vesicles as a source of new biomarkers. Our aim is to investigate the differential expression of selected putative onco-miRNAs in normal and PC cells and further establish their clinical utilities as biomarkers for PC. Here, we report the potential role of MVs-associated miRNAs in PC progression and their utility as biomarkers in vitro and in human tissues. The expression of onco-miRNAs was higher in PC patients than normal subjects. High expression of miRNAs suppressed their related targets of tumor suppressor genes, and ectopic expression of some of these onco-miRNAs in benign PC cell lines increased cell growth, migration and invasion.
Urinary Excretion of Renin and Soluble Prorenin Receptor in Hypertension
Minolfa Prieto, Tulane University
The prorenin receptor (PRR) increases renin activity and activates prorenin. To test the hypothesis that increased levels of soluble PRR (sPRR) enhances renin activity in the kidneys of hypertensive (HTN) patients, we measured the urine levels of free sPRR and renin activity (uRen) from 56 patients, including normal subjects (CT; n=18) and patients with HTN without (n=18) and with concurrent diabetes mellitus (DM; n=20). Twenty-six (48%) were women (51±13 years-old) and 30 (51%) were men (50±16 years-old). s(P)RR levels did not differ between HTN and HTN+DM patients but were lower compared to CT (HTN: 580±131 and HTN+DM: 500±85 vs. CT: 1,248±346 pg/mg; p<0.05). uRen activity was similar between HTN and CT subjects (22±9 vs. 25±10 ngAngI/hr/mL), but higher in HTN+DM patients (164±16 ngAngI/ml/hr; p<0.05). These data suggest that PRR bound to cell membrane, but no sPRR, might be responsible for the increases in uRen activity in HTN patients with DM.
Time Restricted Feeding to Improve Insulin Sensitivity and Vascular Function
Courtney Peterson, Pennington Biomedical Research Center
It is widely believed that grazing improves blood sugar control and overall health. However, recent evidence in rodents suggests that grazing contributes to weight gain, inflammation, and worse glucose tolerance. In comparison, time-restricted feeding (TRF), which involves eating in a narrow time window followed by a daily 15-20 hour fast, reduced metabolic disease and abrogated weight gain in rodents. We will conduct the first pilot study of TRF in humans. In this crossover study, 8 obese men will be randomized to either 5 weeks of TRF or grazing, followed by a 7-week washout period, and then 5 weeks of the other feeding condition. Calories, meal frequency, and diet composition will be matched in each group. Before and after each arm of the study, glucose homeostasis, vascular function, inflammation, and key hormones will be measured. It is hoped that this study will lead to novel insights into how meal timing impacts health and disease risk.
Predicting the Response of Lipoproteins to Exercise using Clinical and Genetic Data
Mark Sarzynski, Pennington Biomedical Research Center
There is large inter-individual variation in the magnitude of changes in plasma lipoprotein traits derived from regular exercise, and genetic factors appear to contribute to this variability. However, the associations of genomic markers with exercise-induced changes in lipoprotein particle traits have not been thoroughly explored. We hypothesize that adding information on genomic markers will significantly improve our ability to predict the responsiveness of lipoprotein particle traits to regular exercise above and beyond the commonly used clinical predictors. We will test this in the following aims:
Aim 1: Examine the response of lipoprotein particle traits to regular exercise in four exercise training studies in order to define significant clinical predictors of response.
Aim 2: Test whether genetic summary scores derived from GWAS improve the prediction of the response of lipoprotein particle traits to regular exercise compared to standard clinical assessment variables, and determine if this enhanced prediction level is clinically meaningful.
Assessing and Reducing Risk of Violence and Violent Injury Among Victims of Urban Violence
Erich Conrad, LSU Health Sciences Center New Orleans
Victims of urban violence face a perilous trek even after their physical injuries heal. For victims,violent trauma is a recurrent event and many later even die from violence. Victims of urban violence often have histories of violence perpetration and are at a heightened risk for violence in the wake of traumatic injury. Multiple, interrelated risk factors predict later violence and violent injury. Risk behaviors are often exacerbated following traumatic injury, potentially leading to a self-perpetuating cycle of violence and victimization. Interventions to promote behavioral changes that reduce risk may thus be critical in preventing further violence and violent injury. The hospitalization immediately following violent trauma may be a unique window for such care, yet few hospital-based programs exist and empirical evaluations of these programs have yielded mixed results. Our lab has developed an initial draft protocol of a hospital-based intervention for victims of urban violence that is rooted in Transtheoretical Model of Change and Motivational Interviewing.
We propose to refine, implement, and pilot test this intervention among patients hospitalized following a violent injury at an urban Level I Trauma Center. The proposed study will be conducted in two phases: (Year 1) a pre-randomized development phase to systematically refine and standardize our intervention and (2) a pilot randomized clinical trial of efficacy. The RCT will randomly assign violently injured patients to (a) treatment as usual (brief mental health screening and referral (n = 50); (b) a hospital-based Ml protocol (n = 50). Phase 1 outcome measures include both quantitative and qualitative assessments of acceptability and feasibility Phase II primary proximal outcome variables are motivation to change and actions taken to mitigate risk. Phase II distal outcome variables are violent behavior, arrests for violence crime, violent injury, and hospital service utilization due to violent trauma. Risk behaviors (substance abuse, weapon use, anger/irritability, belief in the utility of violence, post-traumatic stress symptoms, unemployment, lack of education, and unstable housing) are included as medial outcomes to examine possible mechanisms of influence between proximal and distal outcome variables.
Investigation of novel genetic factors predisposing to multiple epiphyseal dysplasia and osteoarthritis
Malwina Czarny-Ratajczak, Tulane University
Multiple epiphyseal dysplasia (MED) is a relatively common chondrodysplasia characterized by delayed and irregular ossification of epiphyses and early-onset osteoarthritis (OA). This clinically and genetically highly heterogeneous disorder is caused by mutations in six genes. However, mutations in these genes only explain approximately 50% of all cases, which indicates that defects in other genes are involved. Currently, the overlapping MED/OA phenotype is being reinvestigated since it may provide new insights towards understanding the genetic basis for common forms of osteoarthritis. Our central hypothesis is that there are new candidate genes for MED and mutations in these genes may also contribute to the development of common forms of OA. We plan to identify a new gene(s) for MED using exome-sequencing in four families for whom we have previously excluded all currently known candidate genes and identified a high lod score (5.45) on chromosome 11 indicating a new locus for this disease. We will then determine if changes in the new MED candidate gene predispose to primary OA, by sequencing of the new candidate gene in Louisiana patients with primary knee OA. With respect to expected outcomes, this project has a high chance to result in discovery of a new gene that mutations cause MED and OA. Identification of this gene may also help to develop a new treatment for these disorders; however, this strongly depends on the function of a coded protein. We are planning to analyze this gene in patients with OA from Louisiana and to estimate the genetic predisposition in this group in collaboration with Dr. Vinod Dasa of LSU.
HPV and EBV Serum Antibodies as Prognostic Markers for Cervical Cancer
Rebecca Fisher, LSU Health Sciences Center New Orleans
Human papilloma virus (HPV) is necessary but not sufficient for development of cervical cancer, an epithelial cell malignancy. We have evidence supporting Epstein-Barr Virus (EBV) as a co-factor for HPV related cervical disease in HIV+ women. EBV is the causative agent of the epithelial cell malignancy nasopharyngeal carcinoma (NPC). Serum antibodies against EBV antigens are the best predictor of NPC in high risk populations. This proposal will assess whether serological assays for HPV and EBV antibodies can serve as prognostic indicators of cervical disease. HIV+ human serum samples will be evaluated for 5 antibody markers against EBV and 6 antibody markers against HPV. This data will be combined with my preliminary data to determine the best combination of serum antibodies for predicting cervical disease. The advantages of serum testing will likely increase patient compliance for screening and follow up of cervical disease and therefore improve outcomes for cancer patients.
Evaluation of peg-Arginase I as a Therapeutic for Virus-Mediated Ocular Diseases
Timothy Foster, LSU Health Sciences Center New Orleans
Pathogen-associated ocular diseases are a complex combination of pathogen-mediated trauma and hostmediated inflammation-associated pathologies. We have developed an ophthalmic formulation of pegylated-ArginaseI(peg-ArgI) that has broad anti-pathogen, anti-inflammatory, and antineovascularization activities, while also promoting healing of traumatic corneal wounds (Patents:US13/828,669;PCT/US13/31623). No current drug has all these combined activities. Targeting host metabolic pathways by peg-ArgI to simultaneously ameliorate pathogen- and host-mediated disease sequelae is a novel therapeutic approach with wide-ranging clinical potential. The rabbit eye is an FDA recognized model for establishing an ophthalmic drug’s pharmacological parameters and evaluating clinical efficacy prior to initiating human trials. We will utilize this model to: 1) Establish a dosing regimen for peg-ArgI that prevents both HSV-1 replication and presentation of ocular pathologies and 2)Evaluate peg-ArgI’s ocular safety and toxicity according to FDA recognized protocols. Establishment of these pre-requisite parameters will provide critical support for future human trials of peg-ArgI as a broadly applicable ophthalmic therapeutic.
Analysis of the Pathogenesis of HIV/EBV associated DLBCL
Zhen Lin, Tulane University
Currently, the state of Louisiana has the 4th highest annual AIDS diagnosis rate and the 10th highest HIV/AIDS population in the United States. Nearly 70% of AIDS patients in Louisiana are African American (Kaiser family foundation /statehealthfacts.org). HIV/AIDS is considered one of the major health problems in Louisiana, especially in the medically underserved population. AIDS associated malignancies such as Diffuse Large B-cell lymphomas (DLBCLs) are one of the major factors for AIDS-related morbidity and mortality. The objective of this project is to determine the precise role of Epstein-Barr virus (EBV) in the pathogenesis of the AIDS/EBV associated DLBCLs using the most clinically relevant model system available - clinical specimens. EBV is a primary driver of AIDS associated DLBCLs with a penetrance of nearly 100%. We will use expression and genetic signatures of clinical lymphoma biopsies to determine EBV signaling mechanisms driving lymphomagenesis in AIDS patients.
Targeted microRNA analysis in Multiple Sclerosis associated cognitive decline
Jesus Lovera, LSU Health Sciences Center New Orleans
Deidre Devier, LSU Health Sciences Center New Orleans
Two-hundred-thousand Americans with Multiple Sclerosis (MS) will develop cognitive impairment (CI) resulting in unemployment and social isolation. Innate immunity plays a key role in widespread injury to the brain underlying CI in MS. Currently we cannot measure innate immunity activation in the brain non-invasively and no treatments are available to arrest it. MicroRNAs (miRs) are small RNA molecules that regulate genes in their cell of origin and surrounding cells. MiRs regulating innate immunity activation or linking it with neurodegeneration are over-expressed in CSF of people with Alzheimer disease. Our hypothesis is that these same miRs play an important role in CI in MS; to test our hypothesis we will compare CSF miR in people with MS with and without CI and correlate CSF miRNA with MRI measures of tissue injury. This is a first step in testing this hypothesis, opening novel diagnostic and treatment possibilities for CI in MS.
Development of a PACAP Analog as a Therapeutic for Contrast-Induced Nephropathy
Jerome Maderdrut, Tulane University
The incidence of contrast-induced nephropathy in the general population is low, but can exceed 50% in some subpopulations. No drugs have been approved by the FDA specifically for the prevention of contrast-induced nephropathy. Pituitary adenylate cyclase-activating polypeptide (PACAP) is a multifunctional peptide with potent anti-inflammatory and cytoprotective properties. We have shown that PACAP is efficacious in a novel model of contrast-induced nephropathy. We have synthesized and characterized two series of proprietary PACAP analogs. We have submitted a proposal to NIH to acquire the funds needed to move a lead compound from the preclinical stage of development past the Investigational New Drug application stage of development. The proposal was scored but not funded. There were three major criticisms. The receptor binding data has now been determined by our collaborators. The purpose of this proposal is to obviate the other two major criticisms and then resubmit the scored NIH proposal.
Screening for glycosylation disorders and study galactose intake in PGM1-CDG
Eva Morava-Kozicz, Tulane University
Hypoglycemia is the most common metabolic condition in newborns and infants. We defined a novel inborn error of metabolism due to Phosphoglucomutase (PGM1) deficiency. The novel condition presents with severe neonatal, and recurrent infantile hypoglycemia associated with abnormal growth and endocrine abnormalities of variable degree (Mohamed et al, BBA, 2011, Timal et al., HMG, 2012). Since 2012 more than 20 patients have been diagnosed with this condition. PGM1 deficiency leads to progressive increase of glycogen concentration in muscle and liver and abnormal protein glycosylation (Congenital disorder of glycoslation: CDG) in blood. In an adolescent patient we observed variable disease severity, depending on the daily milk intake (galactose intake), over a one-year period. One year of therapy with extra oral galactose intake resulted in improved N-linked glycosylation, normalization of liver function tests, prevention of hypoglycemic episodes, and normalization of N-glycosylated hormones and IGF1/IGF3. These observations led us to the hypothesis that PGM1 deficiency alters the balance of glucose-1- and galactose-1-phosphate concentrations leading to abnormal N-glycosylation, and that this phenomenon is most likely influenced by dietary galactose availability.
Aims of our study:
- Hypoglycemia is a common symptom of the Congenital Disorders of Glycosylation (CDG). None of the types of the CDGs have been screened in Louisiana, and no metabolic diagnostic test is available in our state for the more than 50 different types of this condition. We will start a collaborative effort with LSU Health Sciences Center and Children’s Hospital, to set up selective CDG screening, using10 ul plasma or dried Blood spot on filter paper, by transferrin isoelectric focusing (TIEF) in hypoglycemic newborns and infants.
- We clinically follow five patients with the recently discovered inborn error; PGM1 deficiency. The patients are of different age and have a natural, variable galactose intake and remain under regular metabolic and dietary control. In order to study the effects of oral galactose intake on the clinical and biochemical features of affected patients, we will evaluate the correlation between galactose intake, growth parameters, clinical symptoms, diet, and follow the N-glycosylation pattern by TIEF and glucose regulaton related endocrine parameters. These evaluations will be performed on a monthly basis over a one-year period.
Background: The principle investigator has been active as a clinician and scientist in Europe and joined the faculty at Tulane University in 2012. She is a clinical and biochemical geneticist. She has significant expertise in congenital disorders of glycosylation including the description of the PGM1-related glycosylation defect and other new gene discoveries. Deliverables: This study will allow (1) establishment of a novel research line on protein glycosylation at the Hayward Genetics Center (2) collaboration between the Departments of Pediatrics and Genetics at Tulane University and LSUHSC (3) initiation of selective screening for protein glycosylation defects in Louisiana, (4) development of more pathophysiological insight of a novel metabolic disease.
Boron-based 4-hydroxytamoxifen and endoxifen prodrugs for treatment of breast cancer
Guangdi Wang, Xavier
Poor initial response to tamoxifen therapy and persistent side effects remain major clinical challenges in the treatment of breast cancer patients. The boron-based 4-hydroxytamoxifen and endoxifen prodrugs are designed to address both problems by guaranteed delivery of a more potent metabolite of tamoxifen without requiring a functional enzyme (CYP2D6) to convert tamoxifen to 4-hydroxytamoxifen and endoxifen, and by lowering the dose requirement to reduce side effects such as hot flash. The proposed animal study is expected to confirm that the superior activities of the prodrugs in breast cancer cells can be extended to in vivo models. These results will lay the ground work for more extensive pre-clinical studies leading to clinical trials.
Plaque Destabilization through Shear Stress Mediated Decreases in miR-221/222
T. Cooper Woods, Tulane University
Our limited understanding of the mechanisms behind plaque rupture is a critical barrier to developing methodologies for prevention of myocardial infarction and stroke. Our lab has found the expression of two microRNAs and a related circular RNA are altered in plaques postrupture and in relation to shear stress. We hypothesize that increased shear stress alters noncoding RNA (ncRNA) expression to promote plaque destabilization. We will test this via two aims. Aim 1 will identify ncRNAs associated with plaque rupture using next generation sequencing and relate their expression to shear stress. Aim 2 will use a custom-designed bioreactor to demonstrate in vitro that increases in laminar shear stress reduce proliferation and increase apoptosis in vascular smooth muscle cells through changes in ncRNA expression. This project thus combines an innovative approach to studying plaque rupture with cutting edge methodology to determine the role of flow mediated changes in ncRNA in plaque destabilization.
Selective targeting of the metastatic-invasive phenotype of triple-negative breast carcinoma
Bridgette Collins-Burrow, Tulane University
Introduction: Of the more than one million global cases of breast cancer diagnosed each year, approximately fifteen percent are characterized as triple-negative, lacking the estrogen, progesterone, and Her2/neu receptors. Lack of effective therapies, younger age at onset, and early metastatic spread have contributed to the poor prognoses and outcomes associated with these malignancies. Here, we investigate the ability of the histone deacetylase inhibitor panobinostat (LBH589) to selectively target triple-negative breast cancer (TNBC) cell proliferation and survival in vitro and tumorigenesis in vivo.
Methods: TNBC cell lines MDA-MB-157, MDA-MB-231, MDA-MB-468, and BT-549 were treated with nanomolar (nM) quantities of panobinostat. Relevant histone acetylation was verified by flow cytometry and immunofluorescent imaging. Assays for trypan blue viability, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) proliferation, and DNA fragmentation were used to evaluate overall cellular toxicity. Changes in cell cycle progression were assessed with propidium iodide flow cytometry. Additionally, qPCR arrays were used to probe MDA-MB-231 cells for panobinostat-induced changes in cancer biomarkers and signaling pathways. Orthotopic MDA-MB-231 and BT-549 mouse xenograft models were used to assess the effects of panobinostat on tumorigenesis. Lastly, flow cytometry, ELISA, and immunohistochemical staining were applied to detect changes in cadherin-1, E-cadherin (CDH1) protein expression and the results paired with confocal microscopy in order to examine changes in cell morphology.
Results: Panobinostat treatment increased histone acetylation, decreased cell proliferation and survival, and blocked cell cycle progression at G2/M with a concurrent decrease in S phase in all TNBC cell lines. Treatment also resulted in apoptosis induction at 24 hours in all lines except the MDA-MB-468 cell line. MDA-MB-231 and BT-549 tumor formation was significantly inhibited by panobinostat (10 mg/kg/day) in mice. Additionally, panobinostat upregulated CDH1 protein in vitro and in vivo and induced cell morphology changes in MDA-MB-231 cells consistent with reversal of the mesenchymal phenotype.
Conclusions: This study revealed that panobinostat is overtly toxic to TNBC cells in vitro and decreases tumorigenesis in vivo. Additionally, treatment up-regulated anti-proliferative, tumor suppressor, and epithelial marker genes in MDA-MB-231 cells and initiated a partial reversal of the epithelial-to-mesenchymal transition. Our results demonstrate a potential therapeutic role of panobinostat in targeting aggressive triple-negative breast cancer cell types.
Keywords: Panobinostat, LBH589, triple-negative breast cancer, xenograft, histone deacetylase inhibitor, E-cadherin, CDH1, epithelial-to-mesenchymal transition
Molecular Epidemiology and Natural History of Acadian Usher syndrome
Jennifer Lentz, LSU Health Sciences Center New Orleans
Usher syndrome (Usher), the most frequent genetic cause of deaf-blindness, affects 1 in 20,000 individuals worldwide, but is more frequent in some close-knit communities. Fifteen genes are associated with three clinical subtypes. The USH1C c.216G>A mutation accounts for nearly all USH1 cases in the Acadian population of Louisiana. Due to founder effect, the frequency of USH1C appears to be higher in Louisiana, however the real incidence and natural history among our patients is unknown. We created a knock-in mouse containing the Acadian c.216G>A mutation, and showed that treatment with antisense oligonucleotides prevents hearing impairment and improves vision when given early in life. Moving this unique therapeutic opportunity into the clinic requires a better understanding of the incidence in Louisiana, and a clear picture of its clinical evlolution. Our goals are to conduct molecular epidemiology studies and develop a clinical natural history of USH1C in Louisiana, necessary for planning clinical trials.
Cardiovascular disease inflammation is due to macrophage associated lipin-1 activity
Matthew Woolard, LSU Health Sciences Center Shreveport
Cardiovascular disease (CVD) is the number one killer of Louisiana residents, thus new therapeutic options are needed. The underlying cause for almost all catastrophic CVD events is atherosclerosis. Atherosclerosis is a macrophage-mediated chronic inflammatory disorder, thus, inhibition of this inflammation is a potential therapeutic approach to treat CVD. To develop anti-inflammatory therapeutic strategies to treat CVD without making the individual immuno-suppressed we must identify processes that are unique to atherosclerosis. Our work has identified a lipid synthetic enzyme, lipin-1, that uniquely contributes to atherosclerotic macrophage inflammatory responses. Our results suggest this is a targetable process (lipid synthesis by macrophages) that initiates atherosclerotic inflammation. This proposal will elucidate the mechanism by which lipin-1 elicits atherosclerotic inflammation in vitro and test the feasibility of targeting this protein to treat CVD in vivo. As such this proposal is a vital translational step in the development of new therapies to treat individuals with CVD.
Vaccine efficacy in diabetic and elderly patients
Elizabeth Norton, Tulane University
Our goal is to determine if an individual’s level of inflammation determines their response to vaccination. The aging process and certain diseases, like type-2 diabetes, have been characterized as chronic inflammatory conditions. Affected individuals have higher rates of influenza disease and health care costs; hence, yearly vaccination is recommended. There is a paucity of information comparing vaccination in these high-risk groups and identifying biomarkers that can predict vaccine efficacy. We hypothesize that elderly and diabetic patients have reduced responses to seasonal influenza vaccination that are inversely proportional to their level of chronic inflammation. In this pilot proposal, we will examine adult and elderly diabetic and non-diabetic adults for markers of inflammation and vaccine efficacy before and after influenza vaccination. These studies will help
our understanding of how chronic inflammatory diseases impact immunologic function and future research on mitigation strategies.
Endothelial microparticles in COPD: Effect of vascular-targeted therapy
Matthew Lammi, LSU Health Sciences Center New Orleans
An exciting avenue of drug discovery in COPD revolves around the pulmonary vasculature; changes in the pulmonary vessels/endothelium occur early in the clinical course and may play an active role in the pathogenesis of disease. Biomarkers that may be used to facilitate new treatment strategies are endothelial microparticles (EMPs), submicron vesicles generated from endothelial cell membranes. EMPs may be important in the pathogenesis of COPD, can be used as a biomarker indicating endothelial damage, and may be useful in determining which patients could benefit from vascular-targeted therapy. Our current work suggests that a prostacyclin analog may selectively reduce systemic inflammation by altering the endothelium. EMPs may be exploited to understand the mechanism of benefit of iloprost and to predict which patients will benefit from this therapy. We propose an investigation using blood from patients with COPD receiving iloprost or placebo, as well as in vitro experiments utilizing human endothelial cells.
Testing glial pathways to HAAF in human subjects using 13C magnetic resonance spectroscopy
David McDougal, Pennington Biomedical Research Center
Hypoglycemia-associated autonomic failure (HAAF) is a condition commonly developed in diabetic patients, which often causes life threatening bouts of hypoglycemia. These hypoglycemic crises are a significant impediment to the maintenance of healthy blood glucose levels in individuals with diabetes. HAAF is thought to be driven by cellular or metabolic adaptations in the brain which alters its response to hypoglycemia. Studies in rodents have demonstrated that dietary restriction can produce alterations in brain metabolism similar to those associated with HAAF. Therefore, we hypothesize that HAAF may be driven by metabolic adaptations in the brain, normally induced by prolonged starvation, which are triggered in diabetic individuals by treatment induced exposure to hypoglycemia. The primary goal of our LA CaTS pilot project is to conduct a prospective observational study in humans to test the hypothesis that prolonged fasting will cause alterations in brain metabolism similar to those observed in individuals with HAAF.
Detection of Hereditary Colorectal Cancer Mutations in Cajuns
Jordan Karlitz, Tulane University
Cajuns are the majority of the white population in the Acadian region of south Louisiana. We have recently uncovered that colorectal cancer (CRC) prevalence in whites in the Acadian parishes are disproportionately higher than the rest of the state and are among the highest in the U.S. Furthermore, CRC is developing at a young age in the region. Since the Cajuns are a known founder population for multiple genetic diseases, it is likely that these high CRC rates are due to a founder mutation in for hereditary CRC, like Lynch syndrome (LS). In order to analyze this further, we will test CRC samples from these young Cajuns for microsatellite instability, a hallmark of LS. Our project will address an important public health concern since early intervention can effectively decrease CRC incidence and mortality.
Plaque destabilization via shear stress and vascular strain induced changes in non-coding RNA
T. Cooper Woods, Tulane University
Our limited understanding of the mechanisms behind plaque rupture is a critical barrier to developing methodologies for prevention of myocardial infarction and stroke. Our lab has found the expression of two microRNAs and a related circular RNA are altered in plaques post-rupture and in relation to shear stress. We hypothesize that increased shear stress and vascular strain alters non-coding RNA (ncRNA) expression to promote plaque destabilization. We will test this via two aims. Aim 1 will identify ncRNAs associated with plaque rupture using next generation sequencing and relate their expression to shear stress and vascular strain using computational modeling. Aim 2 will use custom-designed bioreactors to demonstrate in vitro that increases in laminar shear stress and in vascular strain reduce proliferation and increase apoptosis in vascular smooth muscle cells through changes in ncRNA expression. This project thus combines an innovative approach to studying plaque rupture with cutting edge methodology to determine the role of flow and strain mediated changes in ncRNA in plaque destabilization.
Overcoming Immunity to Change: A feasibility study of a new method to promote medication adherence among older adults with hypertension
Marie Krousel-Wood, MD, Tulane University
The prevalence of hypertension in Louisiana exceeds the national average, with >70% prevalence among those age 65+, attributed, in part, to high prevalence of obesity across all age groups. Despite availability of lifestyle behaviors and effective medications to control blood pressure (BP), only 53% of US adults have controlled disease. Furthermore, racial and gender disparities in the control of hypertension exist. Inadequate control of hypertension is associated with poor medication adherence. Despite decades of research, no single intervention has emerged as superior in improving adherence and BP control. There is an urgent need for patient-centered interventions to improve adherence. On the basis of prior work that identified 6 ‘hidden motive’ clusters associated with patients’ ‘immunity to change’ their medication-taking behavior, the objective of this pilot study is to assess the feasibility of using the Overcoming Immunity-to-Change approach to improve medication-taking behaviors and BP control in nonadherent elders with uncontrolled hypertension.
Effect of Combination Therapy with Sodium Nitrite and Isoquercetin on Endothelial Function and Inflammation among Patients with Chronic Kidney Disease
Jing Chen, MD, MMSc, MSc, Tulane University
Chronic kidney disease (CKD) related cardiovascular disease (CVD) and end-stage renal disease are major causes of death in Louisiana. Endothelial dysfunction and inflammation are common etiological pathways for rapid CKD progression and excess CVD risk among CKD patients. The proposed randomized controlled trial will test the safety and efficacy of combination therapy with sodium nitrite and isoquercetin on endothelial function and inflammation among CKD patients. We will recruit 70 albuminuric CKD patients and randomly assign them to combination therapy with sodium nitrite and isoquercetin or placebo for three months. The primary study outcome is endothelial function assessed by brachial artery flow-mediated dilatation (FMD). Our study has 80% statistical power to detect a 2.8% difference in FMD with a 2-sided significance level of 0.05. This study will generate necessary pilot data for an NIH-supported clinical trial to test the efficacy of combination therapy with sodium nitrite and quercetin on CKD progression.
Unintentional overfeeding of formula fed infants
L. Anne Gilmore, PhD, RD, LDN, Pennington Biomedical Research Center
Leanne Redman, PhD, FTOS, Pennington Biomedical Research Center
Despite an almost identical energy density between infant formula and breastmilk, formula fed infants experience greater weight gain in the first year of life. We propose that unintentional overfeeding, of nearly one additional day of calories per week, due to the “over-scooping” of powdered formula contributes significantly to this phenomenon and potentially to the early development of childhood obesity, a significant public health problem. Research of US infants indicates that infant formula use is most prevalent in families with lower levels of education and poverty and as such infant formula is provided to families within the National Women, Infants and Children program. Thereby, the proposed project will examine the health literacy of individuals in the understanding of infant feeding and in particular in the preparation of infant formula. Infant preparation instructions will be modified in through qualitative research to make them more understandable and actionable with an aim of improving caregiver ability to accurately prepare infant formula without overfeeding. The impact of modified formula instructions will then be tested in a randomized controlled trial in comparison to existing commercially instructions provided on the most used brand of infant formula in the US. This is a novel translational study which if successful will demonstrate that with easier to follow preparation instructions, caregivers will less likely overfeed infants resulting in decrease infant adiposity and risk for childhood obesity.
Cervical Cancer Prevention in Louisiana
Michael Hagensee, MD, PhD, LSUHSC New Orleans - Principal Investigator
William Robinson, MD (Tulane University)
Amber Naresh, MD, PhD (Tulane University)
Jerry McLarty, PhD (LSUHSC Shreveport)
Holiday Durham, PhD, RD, LDN (Pennington Biomedical)
Donna Williams, MPH, DrPH (LSUHSC New Orleans)
Jennifer Cameron, PhD (LSUHSC New Orleans)
With successful screening programs and appropriate implementation of the HPV vaccines, cervical cancer can be eliminated in the US. Louisiana ranks fourth in cervical cancer incidence and third in mortality due to limited healthcare resources. Innovative cervical cancer prevention programs that are sensitive to the unique challenges of limited-resource, health-disparate communities is hypothesized to greatly reduce cervical cancer morbidity and mortality in Louisiana. Four research projects will address this hypothesis by identifying cultural, socioeconomic and treatment factors that promote use of HPV vaccines; evaluating self-sampling with HPV testing as a primary screening alternative; identification of nutritional risk factors that promote regression of low-grade cervical intraepithelial lesions and discovery of novel molecular biomarkers that predict progression of low-grade lesions to high-grade lesions. These efforts will combine expertise from LSU-New Orleans, LSU-Shreveport, Pennington Biomedical Research Center and Tulane University School of Medicine to reduce the impact of cervical cancer in Louisiana.
Hydrogen Sulfide Metabolism in Critical Limb Ischemia
Christopher Kevil, PhD, LSUHSCShreveport - Principal Investigator
David Lefer, PhD (LSUHSC New Orleans)
Albert Sam, MD (Tulane University)
Critical limb ischemia (CLI) represents the extreme progression of peripheral artery disease (PAD) often resulting in limb loss along with a very large increase in cardiovascular mortality due to secondary events such as myocardial infarction or stroke. Therapeutic options for CLI patients are few and largely consist of surgical revascularization and amputation. Importantly, key pathophysiological contributors to CLI remain poorly understood. Recent experimental studies indicate that the gasotransmitter hydrogen sulfide ameliorates vascular dysfunction and restores ischemic tissue perfusion, yet hydrogen sulfide bioavailability in clinical and experimental CLI remains unknown. This application will test the hypothesis that hydrogen sulfide bioavailability is significantly decreased in CLI patients and in a large animal model of CLI. This hypothesis will be tested through the pursuit of two aims that will: 1) measure plasma and tissue hydrogen sulfide metabolite bioavailability in CLI patients, and 2) Determine the effects of a novel H2S-donating agent (i.e., Enalapril-TBZ) in a clinically relevant swine model of Critical Limb Ischemia. Hydrogen sulfide metabolites will be measured in clinical CLI specimens obtained from LSUHSC-Shreveport and Tulane University SOM, and the Enalapril-TBZ H2S based therapeutic study performed in a swine model of CLI. Results from this collaborative project will establish the foundation for future clinical research and novel treatment modalities for patients with CLI.
Novel tissue selective estrogen complex with Bazedoxifene and the prevention of metabolic dysfunction in post-menopausal women
Franck Mauvais-Jarvis, MD, PhD, Tulane University - Principal Investigator
Eric Ravussin, PhD (Pennington Biomedical)
Frank Greenway, MD (Pennington Biomedical)
Pairing the selective estrogen receptor modulator, bazedoxifene (BZA), with conjugated estrogen (CE) as a tissue-selective estrogen complex (TSEC), is a novel menopausal therapy. Using a mouse model of post-menopausal metabolic syndrome, we recently reported that TSEC prevent estrogen deficiency-induced metabolic dysfunction without causing endometrial hyperplasia. We found that CE, BZA or TSEC increased energy expenditure and fat oxidation thus preventing obesity and glucose intolerance. Importantly, estrogens improved metabolic homeostasis by increasing production of the hormone fibroblast growth factor 21 (FGF21). A pilot cross over study under the leadership of Dr. Ravussin will translate these findings in a small cohort of six postmenopausal women. We will investigate the effect of TSEC on basal metabolic rate, fat oxidation, body composition and systemic insulin action. In parallel, under the leadership of Dr. Mauvais-Jarvis, we will continue our basic investigation using our mouse model to test the hypothesis that TSEC enhance FGF21 sensitivity.
Community-Wide Health Assessment for West Carroll Parish
Peter Katzmarzyk, PhD, Pennington Biomedical Research Center, Principal Investigator
The objective of this project is to conduct a baseline health assessment of chronic disease, risk factors, and risk factor knowledge in West Carroll Parish. The community health assessment will include two components:
- A population health phone survey conducted by the LSU Public Policy Research Lab (address-based sample of 2,500 households; anticipate ~400 respondents), and
- Community health screenings (screening for CVD risk factors including obesity, hypertension, diabetes and dyslipidemia; 200 participants) conducted at the LSU/SU AgCenter Research and Extension Site in Oak Grove, Louisiana.
A Predictive Modeling Framework for Studying Disparity in Colorectal Screening
Prerna Dua, PhD, Louisianan Tech University
In collaboration with the LA CaTS Center Biomedical Informatics Core
This proposal aims to develop a colorectal cancer data repository by engaging participation from the Louisiana Clinical Data Research Network (LACDRN) from a regionally distributed population, and developing a predictive model by identifying the underlying key factors that are highly correlated with the gender and race. The proposed predictive model will then aid in computing the confidence associated with each patient on the risk of developing colon cancer. The results generated from the proposed study will lead us to advance in closing the loop between the established factors of race and gender as being the covariates, along with other unidentified and underlying environmental and socio-economic factors from South Louisiana.
Neurolymphatic Biomarker Analysis in Multiple Sclerosis
Urska Cvek, ScD, MBA, LSU Shreveport
J. Steven Alexander, PhD, LSUHSC Shreveport
Multiple sclerosis (MS) is a complex, devastating and enigmatic immune-mediated neurovascular disease of the central nervous system (CNS) that is characterized by inflammatory demyelination, degeneration of neurons and axonal loss. In our project we are proposing to examine endothelial particles that represent the future for analysis of blood biomarkers, as they can simultaneously provide information on several proteins originally derived from the brain cell surface. We would like to validate these biomarkers against the MRIs of the patients, which, until this time, have been the only objective and reliable diagnostic tool for MS. If our hypotheses are confirmed our project will propel the neurolymphatic biomarker matrix as a potentially new, non-invasive and inexpensive tool for diagnosis and monitoring of MS.
*Projects initiated and supported by one or more of the LA CaTS Center Cores or Resources
Effects of an Evidence-based Prescription Drug Label on Actual Medication Use
Collaborative project between Health Literacy & Community Engagement and Outreach
Kathleen Kennedy, PharmD, Xavier University
This trial may be the first to evaluate the effect of improved prescription labels on patient understanding, appropriate medication use, and health outcomes in an independent pharmacy setting. If the redesigned labels prove to be effective, these finding could be implemented broadly to promote safe and appropriate medication use and support evidence-based standards in development of patient-centered labels.
Caregivers’ Perceived Roles in Caring for Patients with Heart Failure: Implications for Healthcare Providers
Project initiated by Community Engagement & Outreach Resource
Betty Kennedy, PhD, Pennington Biomedical Research Center
Heart failure (HF) represents a momentous burden to patients and the healthcare system. More importantly, HF can be a huge burden for caregivers (usually family or friends), who play major roles in the lives of patients with HF. The purpose of this study was to determine what roles patients and caregivers perceive and desire for themselves, and to compare and contrast these roles with those they perceive to be desired by healthcare providers versus what providers perceive the roles of patients and caregivers are from their perspective. A total of 93 participants (60 patients, 22 caregivers, and 11 providers) were enrolled in the study. Patients and their caregivers individually participated in semi-structured interviews, and providers (cardiologists, nurses, medical assistants) participated in one of two structured focus groups. The major concerns and needs of HF patients causing them the most difficulty was limited ability to perform any activity due to shortness of breath and fatigue, while the uncertainty of HF and not knowing what is going to happen was the most difficult for caregivers. Providers in both structured focus groups regardless of rank order selected compliance with care, compliance with treatment plan, and compliance with medication as the top 3 issues likely to have the greatest impact, and education on the disease first (compliance with care) as the easiest strategy to implement for patients and their caregivers in the management of heart condition. Findings from this study suggest that caregiver interventions are warranted based on patients, caregivers, and providers perceptions.
Establishing a Congenital Zika Virus Infection Model
Cindy A. Morris, Tulane University
The emergence of Zika virus (ZIKV) as a cause of birth defects represents a dramatic and imminent threat to maternal and child health. Through mechanisms that are undefined, ZIKV demonstrates the ability to cross the placenta, infect the developing fetus, and produce devastating neurological sequelae, including microcephaly. Since the infection can be transmitted by sexual contact in addition to mosquito bites, insect vector control alone may be insufficient to stem the epidemic, and women of reproductive age may be at risk even in temperate zones that do not harbor Aedes aegypti. The over-arching goal of this proposal is to develop a tractable animal (guinea pig) model system in which to study congenital ZIKV infection and to determine the susceptibility and permissiveness of the placenta to ZIKV infection toward the future goal of preclinical testing of immune-based therapies, vaccines, and antivirals aimed at preventing fetal transmission and attendant disease.