Summer 2023 project proposals
Project: Role of gut microbiome in 2 models of hypertension
Contact: Dr. John Collister ([email protected]), Veterinary Biomedical Sciences
Description: Hypertension is the most significant risk factor for myocardial infarction and stroke, the first and third most frequent cause of death in the United States, and affects 700 million people worldwide. Despite decades of research, the underlying cause of hypertension in most cases remains unknown. New strategies are required to control high blood pressure and in the present project, we will examine the role of the gut microbiome on blood pressure regulation in two animal models of hypertension. The study of the gut microbiome in pathophysiological states is an area of intense research and there is limited information in the literature on the link between the microbiome and hypertension. Our lab has demonstrated a role of the central hypothalamic median preoptic nucleus (MnPO) in the hypertensive response to both Angiotensin II (AngII) and DOCA (water soluble form of aldosterone) treated rats. We now propose a MnPO-gut microbiome axis in the pathogenesis of hypertension. We will examine the intestinal microbiome in two rodent models of hypertension in MnPO lesioned and control rats to address the following AIMs: 1) What are the effects on the microbiome in chronic hypertensive rats? 2) Does MnPO lesion restore the microbiome while attenuating hypertension in the rat? 3) Does ileal transplantation from MnPO lesioned rats prevent or treat hypertension? The following hypothesis will be tested: MnPO lesion prevents the changes in gut microbiota and increased blood pressure in hypertensive rats. In order to test this hypothesis, MnPO lesioned instrumented rats will be treated with either AngII or DOCA, and cross-transplanted with ileal content during the hypertensive treatment. Continuous measurements of blood pressure will be made via radio-telemetry. Direct microbiota analyses from jejunum, ileum, cecum and colon will be performed.
Techniques used: Training will begin with the surgical procedures involved with chronic instrumentation of the rat. Students will learn one or more of the following techniques: lesion of central brain nuclei using stereotaxic surgery, placement of a chronic indwelling femoral IV and ileal catheters, and/or placement of the blood pressure transducer catheter in the abdominal aorta, as well as anesthesia, general surgical aseptic technique and monitoring of the surgical patient during anesthesia. Students will learn daily metabolic measurements of rodents housed in metabolic cages, computer data compilation of continuous collections of heart rate and blood pressure data via radio telemetry. Lastly, students will learn the proper techniques of euthanizing experimental rats, and harvesting brain and gut tissues for histological and microbial genomic analyses, respectively.
Project: Understanding MHC diversity in spaniel breed dogs
Contact: Dr. Steven Friedenberg ([email protected]), Veterinary Clinical Sciences
Description: Immune-mediated hemolytic anemia (IMHA) is a deadly autoimmune disorder in dogs in which the body attacks its own red blood cells. Many breeds of Spaniel dogs (e.g. American Cocker Spaniels, English Cocker Spaniels, English Springer Spaniels) are highly predisposed to developing immune-mediated hemolytic anemia (IMHA). Presently, the genetic basis of IMHA is poorly understood, but MHC genes are believed to play a role. In this project, the summer scholar will genotype a population of ~100 affected and unaffected Spaniel breeds (American Cockers, English Cockers, English Springers, and Clumbers) at the three polymorphic class II loci (DRB1, DQA1, DQB1) and the most polymorphic class I gene (DLA-88). Common alleles will be determined, and statistical tests will be performed to determine if any of the alleles are associated with IMHA in this Spaniel dog population.
Techniques used: PCR, Sanger sequencing, BLAST database searches, performing basic statistical tests
Project: Lipid metabolism and osteoarthritis
Contact: Dr. Alonso Guedes ([email protected]), Veterinary Clinical Sciences
Description: This project focuses on understanding how lipid metabolism contributes to osteoarthritis (OA) pathophysiology. Specifically, our studies seek to determine both the therapeutic efficacy of soluble epoxide hydrolase (sEH) inhibition in feline OA and understand the enzyme’s role in feline chondrocyte response to pro-apoptotic challenge. Inhibition of arachidonic acid metabolism with COX inhibitors is first-line therapy for OA in animals and humans. sEH is an enzyme also involved in lipid metabolism that is receiving increasing attention for its role in pain relief and tissue repair. Our overall objectives are i) to elucidate the effect of sEH inhibition on mobility in cats with naturally occurring OA and ii) characterize the effect of sEH in feline chondrocytes. The proposed research is innovative because it will target the symptomatic and structural aspects of feline OA. It is significant because it is expected to provide strong evidence-based proof of principle for further development and future clinical trials of sEH inhibitors, ultimately providing opportunities for the development of novel approaches to treat feline OA.
Techniques used: Clinical trials, apoptosis assays, calcium signaling, immunohistochemistry, western blots, PCR.
Project: MRI biomarkers of canine intervertebral disc degeneration
Contact: Dr. Casey Johnson ([email protected]), Veterinary Clinical Sciences
Description: Degenerative disc disease (DDD) is a major health problem for both dogs and humans. Degeneration of the intervertebral discs in the spine can lead to back pain and disc rupture, which can compress and damage the nerves of the spinal cord. There is a clinical need for new, noninvasive imaging techniques to assess the health of discs and predict whether a disc will rupture so that preventative treatment can be applied. Furthermore, research into the mechanisms of and therapies for DDD largely relies on induced animal models that poorly mimic human disease. Since dogs spontaneously develop DDD, they have significant comparative advantages for studying DDD and its treatment. The goal of this project is to investigate noninvasive, quantitative magnetic resonance imaging (MRI) techniques to detect and characterize disc degeneration in dogs. The summer scholar will compare quantitative MRI measures to the biochemical composition of canine intervertebral discs. A series of canine vertebral column specimens from the thoracolumbar region of the spine will be imaged ex vivo at 3T MRI and then subsequently analyzed with biochemical assays and histology. This project will lay the groundwork for future in vivo MRI studies in dogs.
Techniques used: Quantitative MRI, biochemical assay, and histology data collection and analysis; scientific communication (presentation and writing)
Project: Characterization of immunosuppressive environment in canine osteosarcoma
Contact: Dr. Jessica Lawrence ([email protected]), Veterinary Clinical Sciences
Description: B7-H3 promotes an immunosuppressive microenvironment in osteosarcoma by inhibiting a cytotoxic immune response. It is therefore a promising new target for cancer immunotherapy. B7-H3 expression is found on osteosarcoma cells and on immune suppressor cells that infiltrate tumors, like regulatory T cells (Tregs), macrophages and myeloid derived suppressor cells (MDSCs). B7-H3 protein expression has also been identified in high levels in canine primary osteosarcoma and pulmonary metastatic lesions. For this study we will use flow cytometry to evaluate B7-H3 expression from blood in dogs with osteosarcoma and investigate changes in expression after palliative intent radiation therapy.
Techniques used: Clinical data collection, flow cytometry and analysis
Project: Serum exosomes as biomarkers for osteosarcoma progression
Description: The student will test the hypothesis that the concentration of exosomes in blood are associated with the presence and the expected behavior of osteosarcoma in dogs. Additionally, the student will contribute to a project that will characterize the molecular composition of exosomes to understand mechanisms through which they might influence metastasis, response to therapy, etc.
Techniques used: Sample (serum/plasma) processing and experimental protocols according to best practices following good laboratory practice guidelines. Experimental design, clinical trial eligibility, regulatory oversight, sample collection, exosome isolation, credentialing kits and SOPs, exosome characterization and quantification, immunoblotting, familiarization with electron microscopy, nanoparticle tracking, data analysis, statistics.
Project: Animal models of pediatric of orthopaedic diseases
Contact: Dr. Ferenc Toth ([email protected]), Veterinary Clinical Sciences
Description: The primary focus of the lab is to develop large animal models of human orthopaedic disorders. Ongoing projects aim to improve the currently available animal models of Juvenile osteochondritis dissecans (JOCD) and Legg-Calve-Perthes Disease (LCPD). To accomplish these goals the lab evaluates both open and minimally invasive surgical techniques to induce lesions mimicking the human disease then conducts extensive MRI evaluations to follow lesion progression. Final evaluation usually involves histopathology. The lab also has an emerging line of research involving stem cell mediated repair of focal cartilage defects which provides additional opportunities for training.
Techniques used: The successful applicant will have the opportunity to participate in surgical procedures, post-operative care of the research animals, MRI and image processing and data evaluation.
Project: Using canine natural killer cells to kill cancer cells
Contact: Dr. Bruce Walcheck ([email protected]), Veterinary Biomedical Sciences
Description: Our lab is actively involved in developing cancer immunotherapies for humans and companion animals. A current focus is on using as well as engineering human and canine natural killer (NK) cells with enhanced receptors for better engagement of tumor cells. One of our generated receptors expressed in engineered human NK cells is currently being tested in clinical trials by Fate Therapeutics. We are attempting to apply this same approach in dogs. This involves characterizing canine NK cells, which are not well understood at this time, as well as designing and testing recombinant receptors and tumor-targeting antibodies. The summer scholar will be involved in these novel studies to help advance our goal of developing effective immunotherapies for cancer in dogs.
Project: Targeting drug resistance in canine hemangiosarcoma
Contact: Dr. Erin Dickerson ([email protected])
Description: Our lab focuses on identifying and overcoming drug resistance mechanisms in hemangiosarcoma (HSA). We found that a subset of dogs with tumors classified as inflammatory HSAs exhibit a longer overall survival compared to dogs with an angiogenic subtype when treated with doxorubicin. We also found that cell lines derived from inflammatory HSAs express low levels of a gene that renders them susceptible to chemotherapy. Over-expression of this gene in HSA cells significantly increased resistance to doxorubicin. The goal of this project is to determine if altering the expression of this gene regulates responses to doxorubicin in other HSA cell lines and in an HSA xenograft tumor model. The Summer Scholar will be involved in these novel studies to help advance our understanding of the development of drug resistance in HSA and determine if a subset of dogs can be identified that will benefit from doxorubicin chemotherapy.
Techniques Used: Cell culture, immunoblotting, cell viability assays, gene knockout and overexpression, data analysis and presentation.
Project: Neuroinflammation Associated with Sequential Traumatic Brain Injury in a Rodent Model
Contact: Dr. Maxim Cheeran ([email protected]), Veterinary Population Medicine
Description: A concussion is the most common type of traumatic brain injury (TBI) and most patients recover without significant CNS pathology. However, these patients are susceptible to the development of neurodegenerative and neuropsychiatric complications after a ‘second hit’ or repetitive TBI, which is common among soldiers and athletes. The present study hypothesizes that a second injury after an initial mild TBI will result in an enhanced neuroinflammatory response, which persists longer and results in greater behavioral deficits. This summer we will be working on a closed-head injury model. Characterizing the inflammation post injury and determining if sequential injuries have a long-term effect on brain function. We also posit that treatment with a stem cell therapy will decrease the window of susceptibility for the second hit to elicit an exaggerated immune response in the brain
Techniques Used: Flow cytometry, IHC, behavior assays and RT-PCR
Project: Disease ecology modeling
Contact: Dr. Meggan Craft ([email protected]), Ecology, Evolution, and Behavior
Description: Develop research project on disease transmission within animal populations. The goal of the research would be to understand the spread and control of infectious diseases in wild or domestic animal populations. This would likely involve testing hypotheses regarding infectious disease dynamics by using real world data in mathematical models. Model output can be used to predict disease dynamics and can guide and prioritize future disease monitoring and disease control strategies. In the past, summer students have participated in the design of the study and have capitalized on the opportunity to take the lead on writing a peer-reviewed manuscript.
Techniques Used: Hypotheses formulation, study design and implementation, data sourcing and cleanup, statistical techniques using the program R, working with a diverse group of collaborators, writing a manuscript (optional).
Project: Reducing mastitis in the dairy cow by increasing the prevalence of beneficial polymorphisms in genes associated with mastitis resistance
Contact: Dr. Brian Crooker ([email protected]), Animal Sciences
Description: Research in our lab is focused on the premise that previous selection practices have successfully increased the presence of genetic polymorphisms associated with increased milk yield but have decreased the presence of polymorphisms associated with disease resistance. We use contemporary Holsteins and unique Holsteins that have not been subjected to selection since 1964 to examine differences in immune and inflammatory responses. This work has included intramammary pathogen challenges with E. coli or S. uberis and whole blood stimulation assays to assess differences in activated immune pathways among individual cows that differ in their susceptibility to mastitis. The long-term goal of our efforts is to increase the presence of polymorphisms that strengthen immune function and increase mastitis resistance in future Holstein cows. The Summer Scholars project could focus on antimicrobial components in milk that inhibit bacterial growth and enhance the ability of the cow to defend against mastitis. In addition to participating in other lab activities, this work would involve examining the impact of milk components on bacterial growth in milk collected from unselected and contemporary Holsteins.
Techniques used: Animal handling, milking, blood and milk sample collection, sample processing and analysis and bacterial culture techniques
Project: Solving disease problems for the poultry industry
Contact: Dr. Tim Johnson ([email protected]), Veterinary Biomedical Sciences
Description: Our lab works collaboratively with the poultry industries of Minnesota to tackle bacterial disease issues. There are currently three diseases we are focused on which have been deemed either persistent, emergent, or re-emergent by poultry veterinarians. We have been working with these veterinarians to build collections of bacterial isolates. A key question we seek to answer with these isolates is how much the bacterial strain matters? Do these diseases occur only directly in response to the level of bird stress, or do some strains have an enhanced ability to cause disease? This project will work towards answers to this question.
Techniques used: For all of these poultry diseases, there is a simple model that uses embryonated eggs. This is a very nice model because it avoids the need to sacrifice large numbers of live birds to get to these answers. It is also a very simple model that can be done within our laboratory. Your task will be to work with us and poultry veterinarians on identifying field strains to test, and applying them to this embryo model. You will also learn how to culture and enumerate bacteria, and how to perform PCR to identify those bacteria.
Project: Discovery of novel anti-parasite drugs for apicomplexans
Contact: Dr. Roberta O'Connor ([email protected]), Veterinary Biomedical Sciences
Description: Our lab focuses on discovering drugs with anti-parasitic activity in compounds sourced from marine organisms and from fungi isolated from the Soudan Mine. Our main interest is Cryptosporidium, a gastrointestinal parasite of worldwide significance. However, we also screen against Toxoplasma gondii, as this parasite is easier to manipulate in the laboratory and can serve as a model for the more intractable Cryptosporidium. The summer student would follow up on compounds we obtained from our recent screen select Soudna mine fungal metabolites that are effective against both Toxoplasma and Cryptosporidium. The student would conduct assays to: a. determine the effective concentrations at which 50% and 90% of the Toxoplasma parasites are killed, b. determine if the metabolites are effective against extracellular parasites; and c. characterize the morphology of parasites treated with these metabolites. Depending on how quickly progress is made, the student may also investigate the the metabolites effects on host cell invasion.
Techniques used: Cell and parasite culture, immunofluorescence assays, drug susceptibility assays of intracellular and extracellular Toxoplasma parasites (luciferase based), and invasion inhibition assays.
Project: Immune Drivers of PRRSV Evolution
Contact: Dr. Maxim Cheeran ([email protected]), Veterinary Population Medicine
Description: Genetic variation and the presence of multiple co-circulating genetic strains, or "lineages" is the norm for many pathogens, particularly for rapidly evolving viruses, like porcine reproductive and respiratory syndrome virus (PRRSV). Immune response to one lineage may not be completely protective to different lineages. This study will assess the cross-immunity generated by porcine B-lymphocytes to a related lineage. The goal of the project is to elucidate the potential for immune-mediated competition amongst co-circulating lineages and determine how immunity influences evolution of PRRSV. The project will explores how immunity-driven factors (humoral immunity), such as vaccination or prior infection, may impose selective pressure on viral evolution and alter the transmission dynamics for multi-lineage pathogens. The project will advance our understanding of the evolution, transmission, and persistence of highly diverse virus lineages in the swine population.
Techniques Used: B cell assays like ELISA/ELISPOT, virological assays like plaque/focus forming unit assay, and virus neutralization assay, sequencing methodologies: including RNA extraction, sequence analysis methods
Population biology and medicine
Project: Cardiac phenotyping in apparently healthy racehorses
Contact: Dr. Sian Durward-Akhurst ([email protected]), Veterinary Clinical Sciences
Description: Sudden death has a devastating impact on the racing industry and there are major safety concerns. Of the hundreds of horses that die on the track each year, the cause of death is not identified for 47% of them. Cardiac arrhythmias are thought to explain many these cases. Most horses that develop arrhythmias have no underlying structural heart disease, making it virtually impossible to detect those that will develop arrhythmias. Arrhythmias in human athletes without underlying structural heart disease are almost exclusively caused by mutations in ion channel genes. These athletes frequently develop subtle ECG changes that are used for monitoring and to guide when retirement from high level athletic performance is recommended. Given the similarities between these arrhythmias in humans and horses, it is likely that mutations in genes responsible for cardiac arrhythmias in humans are associated with alterations in ECG measurements and the presence of arrhythmias in horses. The long-term goal of this project is to identify ECG and genetic markers that predict horses that develop arrhythmias at exercise, with the goal of reducing the rate of SCD. This summer scholars project will focus on collection and analysis of ECGs and cardiac ultrasound in apparently healthy Standardbred and Thoroughbred racehorses.
Techniques used: Communication with racehorse owners, trainers, jockeys, and grooms; collection of ECGs at rest, maximal intensity exercise, and immediately following exercise; interpretation of ECGs at rest, during disease, and following exercise in apparently healthy racehorses; collection and interpretation of cardiac ultrasound of apparently health racehorses; whole blood collection from these horses; state of the art application of genetics to improvement of equine health and welfare; participate in the Equine Genetics and Genomics Lab weekly lab meetings and bi-weekly journal clubs (opportunity to improve presentation skills and genetics understanding); DNA isolation; candidate gene investigation.
Project: White-tailed deer disease ecology
Contact: Dr. Meggan Craft ([email protected]), Ecology, Evolution, and Behavior
Description: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a global pandemic and wild animals have also become infected. SARS-CoV-2 studies in white-tailed deer (WTD, Odocoileus virginianus) show evidence of deer-to-deer and human-to-deer transmission of SARS-CoV-2 variants in free-ranging deer populations in multiple US states, including Minnesota. We have a newly funded project to conduct targeted surveillance of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in White-Tailed Deer. Targeted surveillance will involve disease sampling and placing GPS tracking devices on ~40 deer in late January 2023 at Elm Creek Park Reserve and sampling the same deer in late Feb 2023 (and sample even one more time later in the spring, if possible). I am looking for a motivated student who would be interested in: 1) Resighting the collared deer at Elm Creek using VHF telemetry (so visually make sure they are doing ok using a tracking box and antenna to locate the collared deer); and 2) Developing a behavioral study on the deer during resighting, and/or work on a literature review of SARS-CoV-2 in White-Tailed Deer, and/or analyze any baseline prevalence results that have come in, and/or work with the movement data that will be coming in from the GPS collars and to liaise with Park staff for outreach purposes.
Techniques used: Hypotheses formulation, study design and implementation, data sourcing and cleanup, statistical techniques using the program R, working with a diverse group of collaborators. This would be a good project for a student to gain experience in fields/topics such as disease ecology, infectious disease transmission, movement ecology, spillover, wildlife diseases, and gain skills in field work and/or quantitative analysis.
Project: Evolution of strategies to enhance transfer of passive immunity in dairy calves when supplementing maternal colostrum with colostrum replacements
Contact: Dr. Sandra Godden ([email protected]), Veterinary Population Medicine
Description: Colostrum supplements or replacements (CR) may be added to low quality maternal colostrum (MC) in order to improve levels of protective immunoglobulin G (IgG) delivered to newborn calves. However, early research suggests that spiking unreconstituted CR into moderate quality MC could result in excessively high osmolality of the mixture, resulting in a decrease in abomasal emptying rate, and subsequently decreased IgG absorption into the calf’s circulation. The objective of this field study will be to evaluate the effect of first reconstituting CR with water before feeding (as compared to spiking unreconstituted CR directly into MC), on outcomes of importance in newborn calves, including absorption of IgG, health and fecal scores, appetite, and weight gain in the 3 to 4 days following birth.
Techniques used: Students will manage this field study on a local dairy farm. In addition to learning animal handling and sampling/testing/data analysis techniques associated with the study, you’ll improve your understanding of dairy systems management.
Project: Contribution of sedatives and analgesics on gastroesophageal reflux during anesthesia in dogs
Contact: Dr. Erin Wendt-Hornickle ([email protected]), Veterinary Clinical Sciences
Description: This project focuses on determining whether different sedatives and analgesics contribute to gastroesophageal reflux during anesthesia in dogs. Specifically, our studies seek to determine the role of opioids and alpha-two adrenergic receptor agonists on the frequency and character of gastroesophageal reflux during anesthesia in dogs. Gastroesophageal reflux during anesthesia can cause life threatening damage to esophagus and the respiratory system if gastrointestinal contents reach the airways. Our overall objectives are i) to elucidate if premedication with hydromorphone result in higher incidence of gastroesophageal reflux as compared to premedication with dexmedetomidine ii) determine if premedication with a combination of hydromorphone and dexmedetomidine result in a different rate of gastroesophageal reflux as compared to premedication with each drug alone. The proposed research is significant because it is expected to provide strong clinically-relevant evidence-based proof of principle for optimum management of anesthesia in dogs.
Techniques used: Management of anesthesia and perioperative pain, measurement of gastroesophageal reflux.
Project: Systems-based approaches in aquatic ecosystem health
Contact: Dr. Amy Kinsley ([email protected]), Veterinary Population Medicine
Description: Understanding complex interconnected systems at different scales is a difficult but critical component of addressing ecosystem health challenges. Therefore, ecosystem health uses transdisciplinary efforts to bring together scientists, veterinarians, public health practitioners, government and private sectors, and citizens to manage health at the intersection of human, animal, and environmental health. Such transdisciplinary efforts often require systems-based approaches, which take a holistic approach, considering how the parts of a system interrelate and fit within the context of larger systems. This project will include a review of scientific literature that will be synthesized and prepared for publication and will include a modeling component using available data. The study will identify methods for applying systems-based approaches to manage issues relevant to aquatic ecosystem health, such as pathogens, pollutants, and invasive species. The student will have opportunities to assist with other projects in the lab, including field-based and quantitative research focused on natural aquatic systems and aquatic animal health.
Techniques used: The student will learn about systems-based approaches and ecosystem health; become familiar with common threats to aquatic ecosystem health; learn how to perform a literature search, including data collection, analysis, and visualization; and participate in scientific writing and communication.
Project: Commingling and diet as management interventions for microbiome recovery and AMR mitigation after antibiotic exposures
Contact: Dr. Noelle Noyes ([email protected]), Veterinary Population Medicine
Description: Antimicrobials are used in food animals to treat bacterial pathogens and maintain health and well-being. However, antimicrobial use can also have the negative consequence of selecting for antimicrobial resistance (AMR), which poses public health risks and also contributes to economic loss in swine production. The goal of this project is to determine whether diet and/or commingling can be used to mitigate the spread and persistence of AMR genes within the fecal microbiome after metaphylactic antibiotic use in swine.
Techniques used: The student will gain experience in molecular biology workflows for microbiome studies. They will be involved in lab-based work, primarily processing swabs for genomic DNA extraction using an automated DNA extraction machine, and also involved in field data management associated with the project. Students will have the opportunity to participate in a weekly lab meeting with graduate students, post-docs, research staff and faculty; they are welcome to learn about other research projects being worked on in the lab.