Research Projects
The goal of the Veterinary Scholars Summer Research Program is to increase the number of veterinarians involved in biomedical and clinical research. Take a look at past projects to see the impact the program is having.
I think whether you are looking to pursue a career in research or not, this program is beneficial to having a deeper understanding of the sciences. It allows students to learn how what we learn in classes comes to be. It challenges students and builds confidence.
Veterinary Scholar Participant
2024
Ongoing and Past Research Projects
Pathoanatomical features of the equine pancreas and the correlation to hyperinsulinemia in horses
Researcher: Grace Bronneberg, Purdue University
Mentor: Francois-Rene Bertin
Reliability of Smartphone-Based Two-Dimensional Kinematic Gait Analysis in Healthy Dogs
Researcher: Jaeguk Byun, Purdue University
Mentor: Sun Young Kim
Is shorter better? Detection of caregiver burden in a canine oncology setting using a single-item measure
Researcher: Fionna Freeman, Purdue University
Mentor: Christopher M. Fulkerson
with negative psychosocial outcomes, and early detection may facilitate interventions like
referral to a veterinary social worker. The Zarit Burden Interview (ZBI) adapted for animals is
used to measure burden, but it is a time-intensive tool. This work explores if elevated
burden can be detected using a single-item – “Overall, how burdened do you feel in caring
for your pet?”
Psychometric properties of the single-item screener were examined in relation to the full
ZBI in 315 owners during an initial appointment at a veterinary oncology clinic for a dog with
a confirmed cancer diagnosis. Measures of caregiver burden were completed and
established cutoffs for elevated burden were used. Records were reviewed for the pet's
health status.
Correlation of the single item with ZBI was r = 0.57. One-month test-retest reliability in a
sample subset of owners reporting a dog with stable health was r = 0.39. Receiver
operating characteristic analyses showed area-under-the-curve was 0.81, differentiating
burden groups, (P=.000). Maximized classification accuracy was reached at ≥0.5, with
sensitivity of 0.75 and specificity of 0.83. Elevated caregiver burden was observed in 21.1%
of the sample using the ZBI and 28.7% of cases with the single-item screener.
While the single-item was correlated with the ZBI, test-retest reliability was not acceptable
and over-identified caregiver burden in the sample. If used alone, follow-up of positive
results with the full ZBI is indicated. Further research is needed to optimize a reliable
abbreviated measure to identify burden in owners of pets with cancer.
Innovative delivery of oncolytic adenoviruses expressing IL-27 using adipose-derived mesenchymal stromal cells for prostate cancer treatment
Researcher: Lucie Ganachaud, Purdue University
Mentor: Marxa L. Figueiredo
Leukocyte comparison of barbering and dermatitis conditions in laboratory mice
Researcher: Emily Godollei-Jacob, Purdue University
Mentor: Amanda Darbyshire
The Effect of ADAMTS10-Mutation on IOP-Associated Optic Neuropathy in Canine Glaucoma
Researcher: Haley Harmeson, Purdue University
Mentor: Shin Ae Park
canines. Increased intraocular pressure (IOP) and its negative impact, such as apoptosis and
degeneration on retinal ganglion cells (RGCs) and the optic nerve, is a primary risk factor for
glaucoma. In comparison to dogs with other forms of glaucoma, clinical observations suggest
that Beagle dogs that display ADAMTS10 mutations may exhibit more favorable visual outcomes
despite elevated IOP. However, it remains unclear whether this clinical impression reflects an
intrinsic effect of the ADAMTS10 mutation, the gradual elevation of IOP typically seen in this
form of glaucoma, or other unknown factors. From previous studies, our group developed a
canine ocular hypertensive glaucoma model with controlled IOP elevations, allowing consistent
application of the same magnitude and duration of IOP elevation. In this model, the target IOP
range of 36-45 mmHg can best resemble the human glaucomatous disease mechanism. Using
this preliminary model, we induced controlled ocular hypertension to compare its effects on
glaucoma progression between ADAMTS10-mutant (n=1) and non-mutant (n=1) dogs. The
progression of glaucoma was evaluated based on optical coherence tomography (OCT),
electroretinography (ERG), fundus photography (Retcam), and maze vision testing.
Histopathology of the optic nerves and the eyes will be performed at the end of the study.
Preliminary in vivo results include (1) ADAMTS10-mutant dog showed dramatic fundus
photography changes including altered tapetal reflectivity during IOP elevation. (2) The
ADAMTS10-mutant dog showed decreased ERG values and decreased visual performance in
maze vision testing. (3) In OCT, subjectively, the ADAMTS10-mutant dog appeared to have
more retinal thinning. Unlike the clinical impression, when the same magnitude and duration of
IOP elevation was induced, ADAMTS10-mutant dog might be more susceptible to IOP-induced
optic neuropathy.
Azithromycin Drug Resistance in Acanthamoeba
Researcher: Lucas Hendershot, Purdue University
Mentor: Christopher Rice
significant diseases in humans and animals alike. Species belonging to Acanthamoeba are
responsible for causing granulomatous amoebic encephalitis (GAE), Acanthamoeba
keratitis, skin and systemic diseases. Currently, the best treatment for these infections
involves a chemical combinational therapy made up of non-specific anti-biotics, antifungals,
and anti-parasitics. However, recent studies have suggested Azithromycin, a
macrolide antibiotic, to be a frontline therapeutic against diseases caused by
Acanthamoeba and other free-living amoeba. Azithromycin has been proven to work by
binding to the 50S subunit, specifically the 23S rRNA subunit in bacterial ribosomes. Upon
binding, azithromycin reduces protein synthesis and prevents cellular growth.
Unfortunately, this mechanism has only been validated in bacteria and not in amoeba
species. This study aims to develop azithromycin resistant Acanthamoeba mutants to
potentially yield the phenotypical mechanism of action or resistance pathway(s).
Developing resistant mutants capable of reaching a 100-fold shift in its IC50 towards a
compound is the first step in discovering a mechanical mode of action (MMOA) within
Acanthamoeba. Mutants were developed using a step-wise approach and now we have
mutants growing in 60x-80x concentrations of the original azithromycin IC50. We will use
specific target sequencing and potentially whole genome sequencing of mutants to identify
azithromycin’s MMOA. If successful, this study would be the first to utilize drug resistant
Acanthamoeba for studying molecular modes of action. Understanding the MMOA of
Acanthamoeba is vital to developing enhanced therapeutic drugs that can eectively
mitigate the diseases caused by this organism.
Creating a Xenografted Human Vascularized Chimeric Brain Model
Researcher: Oliver Johnson, Purdue University
Mentor: Ranjie Xu
The Effect of Trazodone on Equine Lameness Examinations
Researcher: Will Kendall, Purdue University
Mentor: Michelle L. Tucker
performing complete examinations is crucial for diagnosis. Patient non-compliance is a
frequent roadblock and also presents safety issues to the veterinarian. Trazodone is
known to have a sedative effect in horses, but is not expected to reduce pain and may
facilitate lameness exams in horses. We hypothesize that trazodone given to a horse at
both a high (10 mg/kg) and low (5 mg/kg) dose will not significantly affect subjective or
objective measurements of lameness, and will not create excessive sedation or ataxia
during an exam. For this study, 18 Purdue teaching horses are weighed and receive a
high dose of trazodone, low dose of trazodone, or a placebo on three separate days. A
straight line jogging evaluation is completed prior to drug administration, and then again
at 30, 60, 120, and 240 minutes post administration. For each evaluation, lameness is
graded by a blinded board-certified surgeon, and objective lameness data (Equinosis) is
also collected. Additionally, video recordings of the joggings are taken and will be
randomized and later reviewed by two separate blinded observers to grade lameness.
Horses are actively monitored for adverse effects of trazodone. Once all of the data is
collected, statistical analysis will compare the lameness grades and objective lameness
data between the placebo and two different trazodone doses for each horse. Final
results of the study are pending, but one horse experienced severe ataxia, preventing
data collection at two time points. Should trazodone not significantly affect lameness,
then it can potentially increase the safety and efficacy of lameness examinations with
uncooperative horses.
Immunolocalization of a Rhoptry Protein, SnROP21, in the Merozoite and Schizont
Researcher: NaLaya Lee, Fort Valley State University
Mentor: Sriveny Dangoudoubiyam
CLCN1 variant predicted to be responsible for congenital myotonia in a domestic shorthair cat
Researcher: Sarah Nelson, Liberty University
Mentor: Kari Ekenstedt
a voluntary contraction for some time after the initial event. This is typically a result of
dysfunction in chloride channels in the skeletal muscle membranes; these channels help
maintain a stable charge across the membrane to prevent spontaneous action potentials.
Variants in the CLCN1 gene (encoding a chloride channel protein) are associated with congenital
myotonia in a myriad of species, including humans, dogs, and the well-known fainting goats.
Recently, a domestic shorthair cat presented with clinical signs that align with congenital
myotonia; the cause of this cat’s disease was unknown but speculated to be genetic. Therefore,
DNA from this cat was subjected to whole genome sequencing, and the data examined for
causative variants private to this cat, compared to >100 other feline genomes (all assumed to
be unaffected by congenital myotonia). A plausible causal variant was identified in this cat’s
CLCN1 gene, specifically a homozygous missense variant (ChrA2:157,195,615 c.979G>T,
p.Val327Phe). In silico testing was explored to predict the effect of this amino acid change,
which likely impairs the ion channel gate function of the protein. Given that this cat was found
as a stray, it can only be speculated that this homozygous variant resulted from inbreeding,
which is not uncommon in feral cat populations. This work adds to our knowledge of congenital
myotonia in cats and across all mammals, which will allow for the continued exploration of new
diagnostic and therapeutic measures in the future.
A Novel TCIRG1 deletion causes autosomal recessive osteopetrosis in a domestic cat
Researcher: Grace Palmer, Purdue University
Mentor: Kari Ekenstedt
Mechanical Testing of Equine Laminae Samples
Researcher: Emily E. Rastovski, Purdue University
Mentor: Timothy B. Lescun
horses on humane grounds. Failure of the laminar junction, which connects the hoof wall to the
distal phalanx, is the mechanism responsible for clinical manifestation of laminitis. However,
there is limited data published comparing healthy and laminitic mechanical strength. Samples of
laminae collected from euthanized horses can be mechanically tested in vitro using a materials
testing system that measures maximum load supported by the laminae. Furthermore, the effects
of storage conditions on the strength of lamina samples are unknown. This study includes two
aims: 1) to determine if different storage conditions affect mechanical testing results and 2) to
determine differences in load-bearing properties between healthy and laminitic tissue. We
hypothesized that 1) there would be no difference in mechanical testing results among
refrigerated, incubated, or frozen tissue and 2) laminar strength would be lower in laminitic
tissue compared to healthy tissue. Here, we first examined the differences in laminar tensile
strength over time in differing storage conditions. Then, differences in laminar strength between
healthy and laminitic tissue were investigated. In the first phase of this study, hoof samples were
collected after euthanasia and divided between refrigerator, incubator, and freezer storage (all
within 2 hours post-mortem). Refrigerated and incubated samples were randomly chosen to be
tested at n=8 time points over 72 hours following time of death. Freezer samples were thawed at
room temperature for 6 hours, then tested at n=8 time points over the next 72 hours post-thaw.
Mechanical testing involved incising samples to fit within a jig, which was placed onto the
materials testing apparatus. Once testing began, the machine pulled the sample apart vertically at
a rate of about 1mm/second until it reached a set displacement endpoint. Measurements of
maximum force sustained by laminae over the testing period were recorded. Results from this
study will provide a foundation for future research investigating laminitis in horses.
Descriptive analysis of highly pathogenic avian influenza outbreak in U.S. from 2022-present
Researcher: Nasir Roberts, Purdue University
Mentor: Wendy Beauvais
Investigating IL-17A-Driven Tertiary Lymphoid Structure Cytokine Expression in Canine Bladder Cancer Cell Lines
Researcher: Brayden Spurlock, Wabash College
Mentor: Meaghan M. Broman
Validation and Temporal Analysis of Differentially Expressed MicroRNAs in Horse Serum Following Intravenous Lipopolysaccharide Administration
Researcher: McKinley Underhill, Purdue University
Mentor: Andrea Pires dos Santos
Antibiogram development for Clostridium perfringens and in-house anaerobic AST verification
Researcher: Caitlin H. Wager, Purdue University
Mentor: Rachel C. Soltys
Affect scores in Veterans with posttraumatic stress disorder (PTSD) in an equine-assisted learning program
Researcher: Elisabeth Wolf, Purdue University
Mentor: Leanne Nieforth
Investigating the association between preterm birth and the development of vocal folds in lamb larynges
Researcher: Gaibrielle Bressler, Purdue
Mentor: Abigail Cox
Voice abnormalities in humans often stem from premature birth, yet few studies have
explored how prematurity affects laryngeal health and voice outcomes. This study aims
to characterize the preterm lamb larynx for future translational studies, specifically
pertaining to preterm infants and school-age children speech pathology. Microscopic
examination focused on 3 lamb larynges: term, preterm, and extreme preterm.
Hematoxylin and eosin (H&E) stains evaluated VF lamina propria (LP) and epithelia
width, while alcian blue (AB) stains assessed glycosaminoglycan and matrix protein
levels. All developmental stages exhibited typical connective tissue components in the
LP. In preterm and extreme preterm VFs, fibroblasts, collagen, elastin, and vessels were
evenly distributed throughout the LP, contrasting with term VFs showing greater spatial
differences, with higher fibroblast and vessel densities in superficial versus deeper LP
layers. AB staining revealed that the deeper LP layers in term VFs had more
alcianophilic glycosaminoglycans than superficial layers, whereas preterm and extreme
preterm VFs showed more uniform glycosaminoglycan distribution. These findings
indicate significant LP reorganization in fetal lamb VFs during later gestational stages.
Future studies should further investigate these developmental changes to understand
their implications for human premature birth and associated voice pathology.
Investigating serum growth differentiation factor-8 concentrations in cats with early chronic kidney disease
Researcher: Kerrigan Fleming, Purdue
Mentor: William Whitehouse
Growth differentiation factor-8 (GDF-8), also known as myostatin, is a negative regulator of muscle growth. In people, GDF-8 is increased with chronic kidney disease (CKD). The objective of this study is to evaluate if the concentrations of circulating GDF-8 in cats with early CKD are increased compared to healthy cats. Associations of GDF-8 concentrations with age, sex, body weight, body condition score (BCS), muscle condition score (MCS), creatinine, blood urea nitrogen (BUN), symmetric dimethylarginine (SDMA), phosphorus, and urine specific gravity (USG) were also examined. Serum concentrations of GDF-8 in healthy (n=10), International Renal Interest Society (IRIS) stage 1 CKD (n=5), and IRIS stage 2 CKD (n=10) cats were quantified using a commercially available multispecies sandwich Enzyme-Linked Immunosorbent Assay (GDF-8/Myostatin; DGDF80; R&D Systems, Inc., Minneapolis, MN). GDF-8 was not different amongst healthy cats (2137 ±740 pg/mL) and cats with IRIS stage 1 (1785 ±530 pg/mL) and IRIS stage 2 (1961 ±638 pg/mL; P = 0.608) CKD. GDF-8 was negatively correlated to MCS (r = -0.517, P = 0.049), but no association was found between GDF-8 and the other selected renal parameters. However, age was significantly higher in IRIS stage 2 CKD cats compared to the healthy cats (P = 0.036), and GDF-8 was negatively correlated with age (r = -0.429, P = 0.032). In conclusion, GDF-8 could be a marker for muscle mass. Further evaluation of the functional role of GDF-8 with age and CKD in cats is warranted.
Characterization of Biomechanical Properties of Canine Sclera and Lamina Cribrosa Tissue Using Atomic Force Microscopy
Researcher: Lisa Hoard, Purdue
Mentor: Shin Ae Park
Glaucoma is a group of progressive optic neuropathies characterized by progressive degeneration of retinal ganglion cells (RGC) with no known cure. The initial insult responsible for the characteristic axonopathy is thought to occur within the lamina cribrosa (LC) region of the optic nerve head. As intraocular pressures rise, the LC is stretched and displaced, along with the other components of the corneoscleral shell, leading to narrowing of perforations containing RGC axons. While the LC is subject to variations in mechanical stimuli, it is a responsive and reactive structure. This project aims to characterize and analyze the biomechanical properties of the sclera and LC in canine eyes using atomic force microscopy (AFM). AFM uses a cantilever to scan across the surface of the sample and obtain various biomechanical measurements, such as force-displacement curves, by analyzing the deflection of the cantilever when the tip comes in contact with the sample. It is hypothesized that in advanced stages of glaucoma the sclera and LC will exhibit a significantly larger elastic modulus compared to normal control eyes. Thus, characterizing the biomechanical properties of normal canine eyes will serve as a control for future comparison with glaucomatous eyes. Overall analysis of biomechanical properties of tissues at the nanoscale from animals affected with naturally occurring glaucoma in life provides more insight into the adaptability of this fibrous shell in response to disease. This helps researchers identify new targets of intervention to manage or prevent advanced stages of glaucoma. By doing so there is potential for long-term preservation of vision in animals predisposed to glaucoma or diagnosed with early glaucoma. The aim of this study optimizes AFM methods to establish normal AFM data for the canine sclera and LC. Thus, this study establishes control data for future studies utilizing AFM to characterize and analyze biomechanical properties in canine eyes with varying types and stages of glaucoma.
MicroRNA differential expression analysis in placental tissue from cases of miscarriage in Brazil
Researcher: Kyra Holt, Purdue
Mentor: Andrea Pires dos Santos
Ureaplasma parvum is a commensal bacterium of the genitourinary tract that when in disbalance, it has been identified as a possible cause of miscarriage in women. MicroRNAs are known for regulating gene expression and their dysregulation have been associated with miscarriage as well. We hypothesized that miRNAs are differentially expressed in the placenta from women with normal delivery versus subjects who suffered an abortion, despite the presence of Ureaplasma. Placental samples from normal delivery and miscarriage cases in Northeastern Brazil previously placed into subgroups based on Ureaplasma parvum infection were submitted to DNA and RNA extraction and qPCR for microRNA differential expression analysis of miR-23a, miR-494-3p, and miR-146a-5p. This is a continuation of a project that had performed microRNA analysis of different markers. miR-23a was overexpressed in patients with normal delivery, despite the presence of Ureaplasma, when compared to patients that had a miscarriage in addition to Ureaplasma infection. MicroRNA expression differences between these groups could be used as prognostic markers for pregnancy in women. Testing in larger cohorts and serum samples are necessary and can contribute to a better understanding of the miscarriage process.
Comparison of debridement of the canine antebrachiocarpal joint by arthrotomy and arthroscopy
Researcher: Madelynn Luebcke, Purdue
Mentor: Sarah Malek
Pancarpal arthrodesis in dogs involves surgical removal of all articular cartilage to the level of subchondral bone. Arthrotomy is the surgical approach used for cartilage debridement that can increase postoperative complication rates due to damage to adjacent soft tissues and blood supply. The objective of this study was to evaluate the feasibility and efficiency of a minimally invasive approach to antebrachiocarpal (AC) joint debridement compared to arthrotomy. Nine pairs of cadaveric canine forelimbs were randomly assigned to one of three groups of six limbs to undergo antebrachiocarpal joint debridement via arthrotomy or arthroscopy using either a rigid arthroscope or a flexible needle arthroscope. Next, the joints were opened and photographed pre- and post-staining with India ink. Percentage of debrided surface area (%DSA) on pre-stained images and completeness of debridement (%C) on post-stained images were measured. Measurements were made for the articular surfaces of the bones contributing to the AC joint (i.e., radius (R), ulna (U), radiocarpal (RC) and ulnarcarpal (UC) bones). Analysis using a linear mixed model for repeated measures found that neither %DSA nor %C significantly differed between groups (P=0.0622 and P=0.5737, respectively). However, both %DSA and %C did significantly differ amongst bone surfaces (P<0.0001). While the %DSA did not significantly differ between the R and RC, the U and UC differed from both R, RC and from each other (P<0.0001). The %C of U was significantly lower than the other three bones (P<0.001). These findings demonstrate that arthroscopic debridement of the AC joint is feasible with similar efficacy to the traditional arthrotomy technique in achieving cartilage debridement.
Antifungal activity of antimicrobial peptide LL-37 on multidrug-resistant fungal pathogen Candida auris
Researcher: Casey Scarnati, Purdue
Mentor: Shankar Thangamani
Candida auris is a relatively recent emerging fungal pathogen. This pathogen is notable in its multidrug resistance to common antifungal cleaners and medication including fluconazole, amphotericin B, and echinocandins as well as its ability to grow biofilm on surfaces and equipment within medical facilities. The peptide LL-37 is a human peptide with antimicrobial activity against Gram-positive and Gram-negative bacteria. The goal of our research was to test the antifungal properties of LL-37 on the growth of colonies of both the wild-type yeast form (0387) and filamentous form (Δalm1) of Candida auris. Colonies of wild-type and mutated filamentous Candida auris were inoculated in YPD broth overnight. They were then cleaned and diluted with 1x PBS until an acceptable absorbance (0.32-0.35 for 0387 and 1.6-2 for Δalm1) was found on a spectrometer reading at a wavelength of 600 nm. The resulting final solution was combined with LL-37 at various concentrations, diluted further by a factor of ten seven times and grown via spot plating assay onto YPD agar plates. These plates incubated for 24 hours afterward. The colony growth following incubation of the wild-type samples was reduced with increasing concentrations of LL-37 while the filamentous Candida auris samples are expected to be unaffected. Concentrations tested (10-200 µg/mL) showed varying levels of growth restriction with the minimum inhibitory concentration found to be near 25-50 µg/mL. In conclusion, the antimicrobial peptide LL-37 has antifungal properties against certain forms of Candida auris. These results show the viability of LL-37 as a potential tool for the removal of Candida auris growth within patients and on medical surfaces.
Does tunnel handling hinder identification of clinical conditions in mice?
Researcher: Jordan Toney, Purdue
Mentor: Amanda Darbyshire
Refined handling techniques such as tunnel handling and cupping, are becoming increasingly popular as they improve the animal welfare of laboratory mice. Tunnel handling has been shown to reduce anxiety in behavioral tests, increase an animal’s willingness to interact with handlers even after brief periods of restraint, and improve physiological parameters like glucose tolerance, blood glucose, and corticosterone levels. It has also been shown to reduce data variability which has the potential to reduce the number of animals needed for a particular study, aiding in the replication of experiments. There is limited research regarding how tunnel handling affects the ability of technicians to identify clinical conditions of mice during routine cage changes. The purpose of this study is to assess how different types of tunnels affect skin lesion identification during cage changes of mice. 50 C57BL6/N female mice housed 5 per cage will have an artificial skin lesion. These lesions will be created under anesthesia using hair removal (hair plucking and shaving) and sharpie markers at various locations (dorsal neck, ventral neck, front limb, inguinal region, base of tail, or none). Six technicians will be instructed to change all 10 cages using the tunnel that is provided (clear, red, or opaque) or tail handling (control). During the cage change, the technician observes each mouse in the tunnel and documents any lesions noticed. The number of correct skin lesions identified for each type of tunnel and traditional tail handling will be compared. Our hypothesis is that the clear tunnels will allow for similar lesion identification as tail handling, which will aid in implementation of refined handling techniques.
Investigating viral associations in ruminant sinonasal tumors
Researcher: Caitlin Wager, Purdue
Mentor: Viju Pillai
Analysis of Fluid Dynamics of the Equine Upper Airway Using 3D Printed Models
Researcher: Audrey Wood, Purdue
Mentor: Michelle Tucker
This project investigates the fluid mechanics of the equine upper airway via the creation of 3D printed anatomical replicas of the trachea, larynx, and nasal passages. These models allow us to assess the performance of these structures in a state of health and provide insight into the dynamic airflow patterns within the equine airway.
The objective of this study is to create separate 3D printed models of each portion of the airway (trachea, larynx, and nasal passages) using 3D Slicer v. 5.6.2. These models will be created in such a fashion that they can be analyzed separately or fit together seamlessly to form the entirety of the airway for more specific applications. The fluid dynamics of air flowing through these structures will be evaluated using computational fluid dynamics (CFD) simulations under physiological conditions.
Results from this study may be used to inform treatment protocols for diseases of the upper airway; this is especially applicable to performance horses affected by both symptomatic and subclinical cases of laryngeal neuropathy. This study offers an approach to improving therapeutic procedures in equine respiratory health.
Can injectable antibodies give failure of passive transfer dairy calves a new lease on life?
Researcher: Emma Zaicow, Purdue
Mentor: Andrew Hubner
bTBI-on-a-Chip: Synaptic Loss Following Blast Induced Traumatic Brain Injury or Biochemical Injury in Vitro
Researcher: Maddison Claybrooke, Franklin College
Mentor: Riyi Shi
Annually, up to 74 million people worldwide suffer traumatic brain injuries (TBIs), many of which go untreated. In particular, TBIs sustained as the result of a pressure wave due to an explosive, called blast TBIs (bTBI), are less likely to be adequately treated due to the initial injury often being mild and difficult to diagnose. TBI is classified into primary and secondary injury. Primary injury is the initial injury resulting from tissue damage and is irreversible, while secondary injury is damage due to the immediately ensuing biochemical cascades that spread from the primary injury. These biochemical cascades include inflammation and enhanced presence of reactive species, such as acrolein, which, if left untreated, can persist for years after the TBI is sustained and damage uninjured cells. These spreading biochemical injuries to the brain can result in an increased chance in developing conditions like epilepsy, neurodegeneration, and psychological disorders. One possible factor linking TBI and long-term pathologies is synaptic loss due to damaged neurons and axons. Synapse loss has already been linked to neurodegeneration, but the mechanisms relating synaptic loss, TBI, and secondary injury pathology remain unclear. While animal models have been helpful in understanding the pathological effects of both primary and secondary injury, the cellular and subcellular mechanism underlying the findings in animal studies remain unclear due to the high number of cofounding variables in animal models. To fill this gap in current knowledge, we developed a platform to deliver clinically relevant blast injuries to primary murine cortical networks in vitro, called bTBI-on-a-Chip, which allows direct study of the cellular and subcellular changes that arise from injury. Using this system, we delivered two types of injury to cultures and studied the resulting changes in synapse density. First, primary blast injuries were delivered to neuronal networks. Second, given that acrolein is a key component of secondary injury, we added a clinically relevant concentration of acrolein to uninjured cultures in order to determine if acrolein alone could cause similar synaptic loss as primary and secondary injury. After each type of treatment, we measured the change in number of synaptic terminals 24 hours post treatment using fluorescent imaging. There were significantly fewer pre and post synaptic terminals on each neuron after both bTBI and acrolein treatment. Together, these findings demonstrate that acrolein alone can cause synapse loss and could therefore be crucial in synaptic changes in secondary injury. Furthermore, our results confirm that even mild blast injury disrupts synaptic numbers in single cells. These findings may help elucidate the relationship between injury, synapse loss, neuron rewiring, and brain pathologies.
Identification of a Novel Candidate Variant in CLPX for Spinocerebellar Ataxia in a Mixed Breed Dog
Researcher: Justin Kim, Vanderbilt
Mentor: Kari Ekenstedt
Spinocerebellar ataxia (SCA) is a progressive neurodegenerative disorder primarily affecting the cerebellum, resulting in the loss of motor control and voluntary muscle coordination. While prevalent in Jack and Parson Russell Terriers due to autosomal recessive mutations in electrolyte channel coding genes such as CAPN1, KCNJ10, SCN8A, SLC12A6, and SPTBN2, an atypical case of SCA was recently documented in a mixed breed dog. Health records and necropsy findings identified paraparesis, SCA, anemia, and retinal degeneration in this individual. Because SCA is an inherited condition, whole-genome sequence (WGS) was generated for the affected dog. The known canine mutations above were not present in the mixed-breed dog’s genome. Principal Component Analysis of genomic data was utilized to confirm the breed identity. The dog’s WGS was then screened for private variants compared to >700 unaffected dogs. This revealed a homozygous 4-base-pair frameshift mutation in CLPX, a gene that encodes for caseinolytic mitochondrial matrix peptidase chaperone subunit X involved in mitochondrial protein degradation, as a novel candidate gene for SCA in any species. In-silico tools predict a frameshift and a premature stop codon within 591 amino acids, truncating 6.64% of the protein. Our study is the first to explore the association of a CLPX mutation with SCA. This connection is potentially significant for human health due to the high evolutionary conservation of CLPX across species.
Investigating suspected mosquitos for the presence of Cache Valley Virus in Indiana
Researcher: Rubyleane Linton, Prairie View A & M
Mentor: Rebecca Wilkes
congenital disabilities in small ruminants, such as goats and sheep. The virus is zoonotic, having
implications for human health as well. Mosquitoes are considered the primary vector of CVV. It
is an emerging pathogen in the U.S and recent serologic testing of aborted small ruminants
suggests this virus is present in Indiana.
This study aimed to identify CVV in Indiana by testing mammal-biting mosquito species
collected from different parts of the state. A previously published real-time reverse transcriptase
PCR was verified for use in the lab and utilized to detect target sequences of CVV within nucleic
acids extracted from mosquito pools collected in 2023-2024. The mosquito species that were
analyzed include Aedes albopictus, Aedes canadensis, Aedes j.japonicus, Aedes vexans,
Anopheles punctipennis, Anopheles quadrimaculatus, Coquillettidia perturbans, and Culex
pipiens (mixed).
While the study is ongoing, no CVV was detected in the 165/648 pools of mosquitoes tested so
far. Detection of positive pools would confirm the presence of CVV in the state. Additionally,
testing various species of mosquitoes from different parts of the state would provide information
regarding the location of the virus and the species of mosquitoes responsible. Traps that collect
these mosquitoes mimic preferred hosts and environments to attract particular species. Infected
mosquito species knowledge is essential in determining which traps will be the most effective in
Indiana to increase the possibility of detecting this virus in the mosquito vector.
Identification of mast cells within the tumor immune microenvironment of canine urothelial carcinoma
Researcher: Ally Schimpf, Purdue
Mentor: Meaghan Broman
There are over 80,000 reported cases of human urothelial carcinoma (UC) each year within the United States which contributes to about 17,000 deaths. Human UC research has shown that the tumor immune microenvironment can contain a variable number of mast cells whose presence may be a prognostic indicator for the response to treatment. Certain breeds of dogs such as Scottish and West Highland White terriers have a high incidence of UC which share many histological, morphological and treatment response similarities with human UC. However, little is known about the number and role of mast cells in canine UC. The goal of this project is to classify mast cell involvement within the tumor immune microenvironment of canine UC while determining mast cell association with prognosis for possible subsequent immunotherapy studies. Canine UC samples obtained from patients of the Purdue University Veterinary Hospital were evaluated by histology and immunohistochemistry. Visiopharm AI assisted technology was utilized for mast cell count, location, and structural distances. The recruitment of mast cells into the tumor microenvironment is governed in part by chemokines secreted by tumor cells. Five different canine UC cell lines were propagated in vitro and evaluated by PCR for chemokine expression. This project will establish foundational data validating the use of canine cancer patients as an invaluable model for human cancer immunological research leading to future immunotherapy studies benefiting both people and veterinary patients.