Scholarly Works, Biomedical Sciences and Pathobiology

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Whole-Genome Sequencing Reveals Breed-Specific SNPs, Indels, and Signatures of Selection in Royal White and White Dorper Sheep
Liao, Mingsi; Kravitz, Amanda; Haak, David C.; Sriranganathan, Nammalwar; Cockrum, Rebecca R. (MDPI, 2026-03-05)
Whole-genome sequencing (WGS) is a powerful tool for uncovering genome-wide variation, identifying selection signatures, and guiding genetic improvement in livestock. Royal White (RW) and White Dorper (WD) sheep are economically important meat-type hair breeds in the U.S., yet their genomic architecture remains poorly characterized. In this study, WGS was performed on 20 ewes (n = 11 RW, n = 9 WD) to identify and annotate SNPs and small insertions and deletions (indels). Functional annotation, gene enrichment, population structure, and selective sweep analysis were also performed. Selective sweep analysis was conducted by integrating the fixation index (F_ST), nucleotide diversity (π), and Tajima’s D to identify candidate regions under putative recent positive selection. A total of 21,957,139 SNPs and 2,866,600 indels were identified in RW sheep, whereas 18,641,789 SNPs and 2,397,368 indels were identified in WD sheep. In RW sheep, candidate genes under selection were associated with health and parasite resistance (NRXN1, HERC6, TGFB2) and growth traits (JADE2). In WD sheep, selective sweep regions included genes linked to immune response and parasite resistance (TRIM14), body weight (PLXDC2), and reproduction (STPG3). These findings were supported by sheep-specific quantitative trait loci (QTL) annotations and previously reported SNP–trait associations. This study provides the first WGS-based genomic comparison between RW and WD sheep, establishing a foundation for future genetic improvement, including targeted selection for enhanced immune function, disease resistance, and other economically important traits in these breeds.
Sample pooling approaches simulated under resource scarcity, lapses in testing capacity, and rapid processing demands for surveillance testing: a data-driven performance comparison
Burgess, Catharine; Curran, Alan; Ceci, Alessandro; Finkielstein, Carla V.; Lahmers, Kevin K. (2026-01-30)
Background: Sample pooling is a critical strategy to meet increased testing demand and conserve resources in surveillance testing. Much of its effectiveness depends on how well optimized the pool size is to the prevalence of infection in the sampled population, which can be difficult to anticipate in many circumstances. Multiple methods exist to better optimize pooling, with unique trade-offs. Methods: Pooling optimization methods were simulated to examine trade-offs between surveillance priorities and operational characteristics using SARS-CoV-2 surveillance data and workflows generated by the Virginia Tech Molecular Diagnostics Laboratory under varying capacity conditions. All in-house validation procedures were designed and established exclusively under CLIA to ensure full control of the analytical framework and to accurately reflect true capacity constraints. We used binary surveillance data to run Monte Carlo simulations (MCS) comparing conservative and large fixed pools, historical prevalence optimization (HPO), prevalence estimation testing (PET), truly optimized pooling, and individual testing. Median test counts from the MCS fed a discrete-event simulation (DES) that assessed processing time at different lab capacities under surveillance and outbreak conditions. We then used the combined performance results to build a classification tree to guide method selection under different testing priorities and constraints. Results: MCS results indicated that small pools (4 samples), HPO, and PET resulted in test counts that were not statistically different from truly optimized pooling (p > 0.05). The DES showed that pooling methods generally performed comparably to individual testing in processing time at low laboratory capacity, but individual testing became faster as capacity increased. Across capacity conditions, individual testing processed fewer than 500 daily samples more quickly, yet it demanded more hands-on time than pooling. Large-scale surveillance favored pooled methods, which were quicker under most conditions, while outbreak scenarios often favored individual testing when capacity wasn’t highly limited. Machine learning analysis highlighted surveillance priorities and sample intake as key determinants in selecting the best pooling optimization method for the given circumstance. Conclusion: This study demonstrates the importance of maintaining multiple pooling optimization approaches and adapting strategies to match evolving demands and potential constraints in surveillance testing.
Venezuelan Equine Encephalitis Virus Antagonizes the cGAS-STING Pathway
Heath, Brittany N.; Akhrymuk, Maryna; Jamiu, Abdullahi T.; Akhrymuk, Ivan; Pickrell, Alicia M.; Kehn-Hall, Kylene (MDPI, 2026-02-10)
Venezuelan equine encephalitis virus (VEEV) is a mosquito-borne pathogen causing low mortality but high morbidity in humans, with 4–14% cases exhibiting neurological complications. While the cyclic GMP-AMP synthase–stimulator of interferon genes (cGAS–STING) pathway is canonically associated with double-stranded DNA (dsDNA) detection, it has been shown to respond to RNA viruses and subsequently limit viral pathogenesis. Several viruses antagonize this signaling cascade, underscoring the importance that cGAS–STING plays in host immunity. Previous studies regarding single-stranded RNA viruses revealed that cGAS–STING limits viral replication in Old World alphavirus chikungunya virus infections, but little is known about New World alphaviruses such as VEEV. Here, we investigate the impact that STING activation has on VEEV infection as a potential prophylactic and therapeutic intervention. VEEV infection alone did not induce STING phosphorylation at Ser366, but interferon-stimulated genes (ISGs) were upregulated during the late phase of infection. Loss of STING through siRNA showed a partial dependency on STING for ISG transcription, suggesting that STING activation may occur through a noncanonical process. Priming of the STING pathway prior to infection was found to be critical in limiting viral replication; however, targeting STING activation post-infection abrogated the antiviral effects that dsDNA had on VEEV. VEEV suppressed STING phosphorylation in a multiplicity of infection (MOI)-dependent manner with the most robust pSTING (Ser366) inhibition observed at an MOI of 10. Collectively, our results suggest that VEEV antagonizes canonical STING activation.
Impaired Complex I dysregulates neural/glial precursors and corpus callosum development revealing postnatal defects in Leigh syndrome mice
Biswas, Sahitya Ranjan; Tomsick, Porter L.; Kelly, Colin; Lester, Brooke A.; Milner, Julia P.; Henry, Sara N.; Soto, Yairis; Brindley, Samantha; Defoor, Nicole; Morton, Paul D.; Pickrell, Alicia M. (Springer Nature, 2025-12)
Leigh syndrome (LS) is a complex, genetic mitochondrial disorder defined by neurodegenerative phenotypes with pediatric manifestation. However, recent clinical studies report behavioral phenotypes in human LS patients that are more reminiscent of neurodevelopmental delays. To determine if disruptions in epochs of rapid brain growth during infancy precede the hallmark brain lesions that arise during childhood, we evaluated neural and glial precursor cellular dynamics in a mouse model of LS. Loss of Complex I significantly impacted neural stem cell proliferation, neuronal and oligodendroglial progeny, lineage progression, and displayed overt differences in specific brain regions across postnatal development. Our findings show that these disruptions in all categories occur specifically within the subventricular zone and corpus callosum prior to the age when these mice experience neurodegeneration. Given that LS is considered a neurodegenerative disease, we propose that there are neurodevelopmental signatures predating classic diagnosis in LS.
Phenelzine-based probes reveal Secernin-3 is involved in thermal nociception
Bustin, Katelyn; Shishikura, Kyosuke; Chen, Irene; Zongtao, Lin; McKnight, Nate; Chang, Yuxuan; Wang, Xie; Li, Jing Jing; Arellano, Eric; Pei, Liming; Morton, Paul D.; Gregus, Ann M.; Buczynski, Matthew W.; Matthews, Megan L. (Elsevier, 2023-02-03)
Chemical platforms that facilitate both the identification and elucidation of new areas for therapeutic development are necessary but lacking. Activity-based protein profiling (ABPP) leverages active site-directed chemical probes as target discovery tools that resolve activity from expression and immediately marry the targets identified with lead compounds for drug design. However, this approach has traditionally focused on predictable and intrinsic enzyme functionality. Here, we applied our activity-based proteomics discovery platform to map non-encoded and post-translationally acquired enzyme functionalities (e.g. cofactors) in vivo using chemical probes that exploit the nucleophilic hydrazine pharmacophores found in a classic antidepressant drug (e.g. phenelzine, Nardil ® ). We show the probes are in vivo active and can map proteome-wide tissue-specific target engagement of the drug. In addition to engaging targets (flavoenzymes monoamine oxidase A/B) that are associated with the known therapeutic mechanism as well as several other members of the flavoenzyme family, the probes captured the previously discovered N -terminal glyoxylyl (Glox) group of Secernin-3 (SCRN3) in vivo through a divergent mechanism, indicating this functional feature has biochemical activity in the brain. SCRN3 protein is ubiquitously expressed in the brain, yet gene expression is regulated by inflammatory stimuli. In an inflammatory pain mouse model, behavioral assessment of nociception showed Scrn3 male knockout mice selectively exhibited impaired thermal nociceptive sensitivity. Our study provides a guided workflow to entangle molecular (off)targets and pharmacological mechanisms for therapeutic development.
Nanosensing of Hepatitis E Virus in Swine Using Graphene
Chick, Shannon; Ataei Kachouei, Matin; Knowlton, Katharine; Meng, Xiang-Jin; Ali, Md. Azahar (IEEE, 2025-07-15)
Sensing of the hepatitis E virus is crucial for effective porcine health management and prevention of spread to humans. This study presents the development of a nanosensor using graphene nanosheets to detect hepatitis E antigen within a minute. The graphene layer not only increases the loading of antibodies specific to the hepatitis E virus but also enhances sensitivity and selectivity. This sensor is sensitive to 10 fM of hepatitis E antigen. This nanosensor holds significant potential for the rapid and early detection and monitoring of hepatitis E, thereby contributing to enhanced public health outcomes and the safety of pork products.
Avian Immunoglobulin Y Antibodies Targeting the Protruding or Shell Domain of Norovirus Capsid Protein Neutralize Norovirus Replication in the Human Intestinal Enteroid System
Xia, Ming; Ichou, Mohamed; Landivar, Mathew; Zhou, Peng; Vadlamudi, Sai Navya; Leruth, Alice; Nyblade, Charlotte; Cox, Paul; Yuan, Lijuan; Goepp, Julius; Tan, Ming (MDPI, 2025-12-05)
Background: Norovirus is a leading cause of epidemic acute gastroenteritis worldwide, associated with significant morbidity, mortality, and economic loss. Despite its global impact, no licensed vaccine is currently available, and vaccine development remains challenging. Methods: We explored avian immunoglobulin Y (IgY) antibodies as a low-cost countermeasure against norovirus infection. We generated recombinant protruding (P) domain proteins from the capsid protein (VP1) of noroviruses, representing two GII.4 variants and the GII.6 genotype. These were combined into a single immunogen to immunize laying hens to produce norovirus VP1-specific IgY antibodies. Results: Immunization of laying hens with the P domain proteins elicited high-titer (>1:450,000) P domain-specific IgY antibodies. The yolk-derived IgY effectively inhibited binding of various norovirus P particles to their histo-blood group antigen ligands, with 50% blocking titers (BT50) up to 1:8533 against homotypic GII.4 and 1:667 against heterotypic G1.1 Norwalk virus P particles. Importantly, the IgY neutralized replication of GII.4 norovirus in the human intestinal enteroid (HIE) system at a high titer of over 1:2500, equivalent to 0.70 µg/mL of total IgY. We also produced norovirus shell (S) domain proteins and corresponding IgY antibodies, which neutralized GII.4 norovirus replication in the HIE model at a titer of ~1:800, equivalent to 2.98 µg/mL of total IgY. This provides the first evidence that the S domain contains neutralizing epitopes. Conclusions: Our findings support the potential of IgY targeting norovirus P or S domains as a scalable, cost-effective strategy for preventing norovirus infection and disease.
Multiplexed smFISH reveals the spatial organization of neuropil localized mRNAs is linked to abundance
Tarannum, Renesa; Mun, Grace; Quddos, Fatima; Swanger, Sharon A.; Steward, Oswald; Farris, Shannon (Society for Neuroscience, 2025-11)
RNA localization to neuronal axons and dendrites provides spatiotemporal control over gene expression to support synapse function. Neuronal messenger RNAs (mRNAs) localize as ribonucleoprotein particles (RNPs), commonly known as RNA granules, the composition of which influences when and where proteins are made. High-throughput sequencing has revealed thousands of mRNAs that localize to the hippocampal neuropil. Whether these mRNAs are spatially organized into common RNA granules or distributed as independent mRNAs for proper delivery to synapses is debated. Here, using highly multiplexed single molecule fluorescence in situ hybridization (HiPlex smFISH) and colocalization analyses, we investigate the subcellular spatial distribution of 15 synaptic neuropil localized mRNAs in the male and female rodent hippocampus. We observed that these mRNAs are present in the neuropil as heterogeneously sized fluorescent puncta with spatial colocalization patterns that generally scale by neuropil mRNA abundance. Indeed, differentially expressed mRNAs across cell types displayed colocalization patterns that scaled by abundance, as did simulations that reproduce cell-specific differences in abundance. Thus, the probability of these mRNAs colocalizing in the neuropil is best explained by stochastic interactions based on abundance, which places constraints on the mechanisms mediating efficient transport to synapses.Significance statement RNA localization establishes compartment-specific gene expression that is critical for synapse function. Thousands of mRNAs localize to the hippocampal synaptic neuropil, however, whether mRNAs are spatially organized as similar or distinctly composed ribonucleoprotein particles for delivery to synapses is unknown. Using multiplexed smFISH to assess the spatial organization of 15 neuropil localized mRNAs, we find that these mRNAs are present in variably sized puncta suggestive of heterogeneous transcript copy number states. RNA colocalization analyses in multiple hippocampal cell types suggest that the spatial relationship of these mRNAs is best described by their abundance in the neuropil. Stochastic RNA-RNA interactions based on neuropil abundance are consistent with models indicating that global principles, such as energy minimization, influence population localization strategies.
Obesity fosters severe disease outcomes in a mouse model of coronavirus infection associated with transcriptomic abnormalities
Rai, Pallavi; Marano, Jeffrey M.; Kang, Lin; Coutermarsh-Ott, Sheryl; Daamen, Andrea R.; Lipsky, Peter E.; Weger-Lucarelli, James (Wiley, 2024-04-01)
Obesity has been identified as an independent risk factor for severe outcomes in humans with coronavirus disease 2019 (COVID-19) and other infectious diseases. Here, we established a mouse model of COVID-19 using the murine betacoronavirus, mouse hepatitis virus 1 (MHV-1). C57BL/6 and C3H/HeJ mice exposed to MHV-1 developed mild and severe disease, respectively. Obese C57BL/6 mice developed clinical manifestations similar to those of lean controls. In contrast, all obese C3H/HeJ mice succumbed by 8 days postinfection, compared to a 50% mortality rate in lean controls. Notably, both lean and obese C3H/HeJ mice exposed to MHV-1 developed lung lesions consistent with severe human COVID-19, with marked evidence of diffuse alveolar damage (DAD). To identify early predictive biomarkers of worsened disease outcomes in obese C3H/HeJ mice, we sequenced RNA from whole blood 2 days postinfection and assessed changes in gene and pathway expression. Many pathways uniquely altered in obese C3H/HeJ mice postinfection aligned with those found in humans with severe COVID-19. Furthermore, we observed altered gene expression related to the unfolded protein response and lipid metabolism in infected obese mice compared to their lean counterparts, suggesting a role in the severity of disease outcomes. This study presents a novel model for studying COVID-19 and elucidating the mechanisms underlying severe disease outcomes in obese and other hosts.
Avian immunoglobulin Y antibodies targeting the protruding or shell domain of norovirus capsid protein neutralize norovirus replication in the human intestinal enteroid system
Xia, Ming; Ichou, Mohamed; Landivar, Mathew; Zhou, Peng; Vadlamudi, Sai Navya; Leruth, Alice; Nyblade, Charlotte; Cox, Paul; Yuan, Lijuan; Goepp, Julius; Tan, Ming (MDPI, 2025-12-05)
Background: Norovirus is a leading cause of epidemic acute gastroenteritis worldwide, associated with significant morbidity, mortality, and economic loss. Despite its global impact, no licensed vaccine is currently available, and vaccine development remains challenging. Methods: We explored avian immunoglobulin Y (IgY) antibodies as a low-cost countermeasure against norovirus infection. We generated recombinant protruding (P) domain proteins from the capsid protein (VP1) of noroviruses, representing two GII.4 variants and the GII.6 genotype. These were combined into a single immunogen to immunize laying hens to produce norovirus VP1-specific IgY antibodies. Results: Immunization of laying hens with the P domain proteins elicited high-titer (>1:450,000) P domain-specific IgY antibodies. The yolk-derived IgY effectively inhibited binding of various norovirus P particles to their histo-blood group antigen ligands, with 50% blocking titers (BT50) up to 1:8533 against homotypic GII.4 and 1:667 against heterotypic G1.1 Norwalk virus P particles. Importantly, the IgY neutralized replication of GII.4 norovirus in the human intestinal enteroid (HIE) system at a high titer of over 1:2500, equivalent to 0.70 µg/mL of total IgY. We also produced norovirus shell (S) domain proteins and corresponding IgY antibodies, which neutralized GII.4 norovirus replication in the HIE model at a titer of ~1:800, equivalent to 2.98 µg/mL of total IgY. This provides the first evidence that the S domain contains neutralizing epitopes. Conclusions: Our findings support the potential of IgY targeting norovirus P or S domains as a scalable, cost-effective strategy for preventing norovirus infection and disease.
High-Frequency Irreversible Electroporation Alters Proteomic Profiles and Tropism of Small Tumor-Derived Extracellular Vesicles to Promote Immune Cell Infiltration
Murphy, Kelsey R.; Aycock, Kenneth N.; Marsh, Spencer; Yang, Liping; Hinckley, Jonathan; Selmek, Aubrie; Gourdie, Robert G.; Bracha, Shay; Davalos, Rafael V.; Rossmeisl, John H.; Dervisis, Nikolaos G. (MDPI, 2025-11-13)
High-frequency irreversible electroporation (H-FIRE) is a nonthermal tumor ablation technique that disrupts the blood–brain barrier (BBB) in a focal and reversible manner. However, the mechanisms underlying this disruption remain poorly understood, particularly the role of small tumor-derived extracellular vesicles (sTDEVs) released from ablated tumor cells. In this study, we investigate the proteomic and functional alterations of sTDEVs released from F98 glioma and LL/2 Lewis lung carcinoma cells following H-FIRE ablation. Mass spectrometry analysis revealed 108 unique proteins in sTDEVs derived from ablative doses of H-FIRE, which are capable of disrupting the BBB in an in vitro model. Proteomic analysis of TDEVs highlights key changes in pathways related to integrin signaling, Platelet-derived growth factor receptor (PDGFR) signaling, and ubiquitination, which may underline their interactions with brain endothelial cells. These “disruptive” sTDEVs exhibit enhanced tropism for cerebral endothelial cells both in vitro and in vivo, where they persist in the brain longer than sTDEVs released after non-ablative H-FIRE doses. Notably, when introduced into a healthy Fischer rat model, disruptive sTDEVs are associated with increased recruitment of Iba1+ immune cells, suggesting a potential role in modulating post-ablation immune responses. However, despite their altered protein composition, these vesicles do not directly increase BBB permeability in vivo. This study is the first to demonstrate that electroporation-based tumor ablation significantly alters the composition and functionality of tumor-derived extracellular vesicles, potentially influencing the tumor microenvironment post-ablation. These findings have important implications for developing multimodal treatment strategies that combine H-FIRE with systemic therapies to enhance efficacy while managing the peritumoral microenvironment.
Laser-assisted surface alloying of titanium with silver to enhance antibacterial and bone-cell mineralization properties of orthopedic implants
Sedaghat, Sotoudeh; Krishnakumar, Akshay; Selvamani, Vidhya; Barnard, James P.; Nejati, Sina; Wang, Haiyan; Detwiler, David A.; Seleem, Mohamed N.; Rahimi, Rahim (Royal Society Chemistry, 2024-05-08)
Orthopedic device-related infection (ODRI) poses a significant threat to patients with titanium-based implants. The challenge lies in developing antibacterial surfaces that preserve the bulk mechanical properties of titanium implants while exhibiting characteristics similar to bone tissue. In response, we present a two-step approach: silver nanoparticle (AgNP) coating followed by selective laser-assisted surface alloying on commonly used titanium alumina vanadium (TiAl6V4) implant surfaces. This process imparts antibacterial properties without compromising the bulk mechanical characteristics of the titanium alloy. Systematic optimization of laser beam power (8-40 W) resulted in an optimized surface (32 W) with uniform TiAg alloy formation. This surface displayed a distinctive hierarchical mesoporous textured surface, featuring cauliflower-like nanostructures measuring between 5-10 nm uniformly covering spatial line periods of 25 mu m while demonstrating homogenous elemental distribution of silver throughout the laser processed surface. The optimized laser processed surface exhibited prolonged superhydrophilicity (40 days) and antibacterial efficacy (12 days) against Staphylococcus aureus and Escherichia coli. Additionally, there was a significant twofold increase in bone mineralization compared to the pristine Ti6Al4V surface (p < 0.05). Rockwell hardness tests confirmed minimal (<1%) change in bulk mechanical properties compared to the pristine surface. This innovative laser-assisted approach, with its precisely tailored surface morphology, holds promise for providing enduring antibacterial and osteointegration properties, rendering it an optimal choice for modifying load-bearing implant devices without altering material bulk characteristics.
Microneedles for Enhanced Bacterial Pathogen Inactivation and Accelerated Wound Healing
Krishnakumar, Akshay; Gallina, Nicholas L. F.; Sarnaik, Devendra; McCain, Robyn R.; Crain, Christa; Tipton, Mason; Seleem, Mohamed; Bhunia, Arun K.; Rahimi, Rahim (Wiley, 2024-08-01)
Bacterial wound infections are a significant socioeconomic concern in the modern healthcare industry owing to increased morbidity, prolonged hospital stay, and mortality. Bacterial infectious agents that colonize the wound bed develop biofilms, acting as a physical barrier that prevents the effective penetration of topical antimicrobials. Further, bacteria in such infectious wounds express a wide range of virulence factors promoting intercellular transmigration and host cell invasion complicating the treatment regimen. To address this need, a water-dissolvable poly-vinyl pyrrolidine (PVP), calcium peroxide (CPO) infused microneedle structure (denoted as PVP/CPO MN) for effective transdermal delivery of antimicrobial payload deep into the tissues is developed. Fluid exudate from the wound bed dissolves the PVP/CPO MN enabling the release of CPO deep into the infected wound bed. A slow catalytic decomposition of CPO results in the sustained release of reactive oxygen species (ROS) deep within the infected wound inhibiting the inter- and intracellular pathogens. Here, a systematic study of microneedle fabrication and sterilization after complete packaging is conducted to ensure scalability and safe applicability while maintaining mechanical and antibacterial properties. In vitro, antibacterial efficacy of the microneedles is validated against two common wound pathogens, Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus). Moreover, the PVP/CPO MN exhibited significant efficacy in eradicating both extracellular and intracellular bacterial populations within an in vivo porcine wound model. Additionally, the microneedle technology facilitated a faster wound healing, with approximate to 30% increase compared to control and a 15% improvement over conventional silver dressing. This study presents a novel approach utilizing dissolving microneedles loaded with calcium peroxide (CPO) for eradicating both intercellular and intracellular pathogens in infected wounds. Through systematic in vitro and in vivo experiments, the microneedles demonstrate effective antibacterial properties against P. aeruginosa and S. aureus, leading to accelerated wound healing. The technology showcases promising potential for clinical translation in wound care practice. image
TKL family kinases in human apicomplexan pathogens
Ali, Dima Hajj; Gaji, Rajshekhar Y. (Elsevier, 2024-09-01)
Apicomplexan parasites are the primary causative agents of many human diseases, including malaria, toxoplasmosis, and cryptosporidiosis. These opportunistic pathogens undergo complex life cycles with multiple developmental stages, wherein many key steps are regulated by phosphorylation mechanisms. The genomes of apicomplexan pathogens contain protein kinases from different groups including tyrosine kinase-like (TKL) family proteins. Although information on the role of TKL kinases in apicomplexans is quite limited, recent studies have revealed the important role of this family of proteins in apicomplexan biology. TKL kinases in these protozoan pathogens show unique organization with many novel domains thus making them attractive candidates for drug development. In this mini review, we summarize the current understanding of the role of TKL kinases in human apicomplexan pathogens' (Toxoplasma gondii, Plasmodium falciparum and Cryptosporidium parvum) biology and pathogenesis.
Meningeal vascular Aβ deposition associates with cerebral hypoperfusion and compensatory collateral remodeling
Kaloss, Alexandra M.; Browning, Jack L.; Li, Jiangtao; Pan, Yuhang; Watsen, Sachi; Sontheimer, Harald; Theus, Michelle H.; Olsen, Michelle L. (2025-11-13)
Background: Global reductions in cerebral blood flow (CBF) are among the earliest and most consistent abnormalities observed in Alzheimer’s disease (AD), preceding both cortical plaque formation and cognitive decline. While the pial arterial network—a critical supplier of intracortical perfusion—has been overlooked in this context, it may play a pivotal role in early vascular pathology. Here, we report extensive cerebral amyloid angiopathy (CAA) within the pial artery and arteriole network in the J20 (PDGF-APPSw, Ind) mouse model of AD. Methods: Using premortem delivery of Methoxy-XO4 to label Aβ, and arterial vascular labeling, we assessed Aβ burden on the pial artery/arteriole network and cerebral blood flow in aged male and female WT and J20 AD mice. Results: We show that 12-month-old J20 mice exhibit significant Aβ deposition across major leptomeningeal arteries (ACA, MCA) and pial collaterals, with ~ 40% vessel coverage in males and ~ 20% in females—substantially exceeding Aβ levels in cortical or hippocampal vessels. This vascular Aβ burden was accompanied by compensatory enlargement and increased tortuosity of pial collateral vessels. Yet, despite this apparent remodeling, CBF was reduced by ~ 15% in J20 mice, and this decline was significantly associated with leptomeningeal CAA burden. Conclusions: This is the first study to comprehensively characterize meningeal arterial Aβ accumulation in a preclinical model of vascular AD, mirroring recent observations in early-stage human disease. Our findings implicate meningeal CAA as a potential driver of early CBF disruption and suggest that pial collateral remodeling may reflect a compensatory response to vascular insufficiency. Moreover, we identify robust sex differences in CAA burden, paralleling sex-specific patterns of parenchymal Aβ pathology in humans. These results highlight the leptomeningeal vasculature as a novel and understudied locus for early AD pathology and a potential therapeutic target to preserve cerebrovascular integrity.
Evaluation of pharmacokinetics of metoclopramide administered via subcutaneous bolus and intravenous constant rate infusion to adult horses
Brandon, Amy M.; Williams, Jarred M.; Davis, Jen L.; Martin, Emily G.; Capper, Ava M.; Crabtree, Naomi E. (Wiley, 2024-08-01)
Objective: To determine the pharmacokinetics (PK) of metoclopramide administered via intravenous continuous rate infusion (IV CRI) and subcutaneous (SC) bolus and evaluate for gastrointestinal motility and adverse side effects. Study design: Experimental study; randomized, crossover design. Animals: Six healthy adult horses. Methods: Each horse received metoclopramide via IV CRI (0.04 mg/kg/h for 24 h) and SC bolus (0.08 mg/kg once), with >= 1 week washout period between. Plasma was analyzed by UPLC-MS/MS. Compartmental modeling was used to determine PK parameters for each treatment; nonparametric superposition was used to simulate multiple SC bolus regimens. Gastrointestinal motility and evidence of adverse effects were monitored. Results: Tmax (h) for SC bolus was 0.583 +/- 0.204 versus 17.3 +/- 6.41 for IV CRI, while Cmax (ng/mL) was 27.7 +/- 6.38 versus 43.6 +/- 9.97, respectively. AUC (h x ng/mL) was calculated as 902 +/- 189 for 24 h IV CRI versus 244 +/- 37.4 simulated for 0.08 mg/kg SC bolus every 8 h. Simulations revealed similar exposure between groups with administration of 0.96 mg/kg/day SC bolus, divided into three, four, or six doses. SC bolus bioavailability was estimated as 110 +/- 11.5%. No clear trends in motility alteration were identified. No adverse effects were noted. Conclusion: Repeated SC boluses of metoclopramide at 0.08 mg/kg would result in lower total drug exposure and Tmax than IV CRI administration but would be highly bioavailable. Clinical significance: Higher and/or more frequent SC bolus doses are needed to achieve a similar AUC to IV CRI. No adverse effects were noted; however, evaluation of alternative dosing strategies is warranted.
Competitive Binding of Viral Nuclear Localization Signal Peptide and Inhibitor Ligands to Importin-α Nuclear Transport Protein
Delfing, Bryan M.; Laracuente, Xavier E.; Jeffries, William; Luo, Xingyu; Olson, Audrey; Foreman, Kenneth W.; Petruncio, Greg; Lee, Kyung Hyeon; Paige, Mikell; Kehn-Hall, Kylene; Lockhart, Christopher; Klimov, Dmitri K. (American Chemical Society, 2024-06-13)
Venezuelan equine encephalitis virus (VEEV) is a highly virulent pathogen whose nuclear localization signal (NLS) sequence from capsid protein binds to the host importin-alpha transport protein and blocks nuclear import. We studied the molecular mechanisms by which two small ligands, termed I1 and I2, interfere with the binding of VEEV's NLS peptide to importin-alpha protein. To this end, we performed all-atom replica exchange molecular dynamics simulations probing the competitive binding of the VEEV coreNLS peptide and I1 or I2 ligand to the importin-alpha major NLS binding site. As a reference, we used our previous simulations, which examined noncompetitive binding of the coreNLS peptide or the inhibitors to importin-alpha. We found that both inhibitors completely abrogate the native binding of the coreNLS peptide, forcing it to adopt a manifold of nonnative loosely bound poses within the importin-alpha major NLS binding site. Both inhibitors primarily destabilize the native coreNLS binding by masking its amino acids rather than competing with it for binding to importin-alpha. Because I2, in contrast to I1, binds off-site localizing on the edge of the major NLS binding site, it inhibits fewer coreNLS native binding interactions than I1. Structural analysis is supported by computations of the free energies of the coreNLS peptide binding to importin-alpha with or without competition from the inhibitors. Specifically, both inhibitors reduce the free energy gain from coreNLS binding, with I1 causing significantly larger loss than I2. To test our simulations, we performed AlphaScreen experiments measuring IC50 values for both inhibitors. Consistent with in silico results, the IC50 value for I1 was found to be lower than that for I2. We hypothesize that the inhibitory action of I1 and I2 ligands might be specific to the NLS from VEEV's capsid protein.
Paradoxical sex differences in a hamster model of angiotensin II-dependent hypertension and associated renal injury
Ji, Hong; Nascimento, Laura G. d.; Ahn, Jungeun; Kwon, Dong H.; Williams, Gabrielle; Wu, Xie; Speth, Robert C.; Hawks, Seth A.; Duggal, Nisha K.; Saavedra, Juan M.; Sandberg, Kathryn; de Souza, Aline M. A. (2025-11-03)
Background: Biological sex is a critical determinant in cardiovascular and renal disease outcomes. Although angiotensin II (Ang II) infusion is widely used to model hypertension in mice and rats, little is known about its effects in the Syrian hamster, a small rodent increasingly used for translational research. This study aimed to develop a model of chronic Ang II-induced hypertension in Syrian hamsters and investigate sex-specific differences in blood pressure, renal pathology, and components of the renin-angiotensin system (RAS). Methods: Male and female Syrian hamsters (8–9 weeks old) were infused subcutaneously with Ang II (200 ng/kg/min) or saline via osmotic minipumps for four weeks. Mean arterial pressure (MAP) and kidney wet weight were determined on the euthanasia day. The kidneys were analyzed for renal pathology; renal RAS enzymes (ACE and ACE2) were measured by colorimetric assay and qPCR; cytokines (IL-6 and IL-1β) were measured by qPCR; and the angiotensin receptor type 1 (AT1R) was measured by radioligand binding and qPCR. Results: Ang II infusion increased MAP in both sexes but elicited a significantly greater response in females (+ 50 mmHg) than males (+ 27 mmHg, p < 0.005). Female hamsters exhibited pronounced kidney injury, including acute tubular necrosis, glomerular sclerosis, and vascular fibrinoid necrosis, along with a 2-fold increase in kidney weight normalized to body weight. Ang II significantly downregulated renal ACE, ACE2, and AT1R expression and activity in females but not in males. Renal IL-6 and IL-1β mRNA levels were elevated 20-fold and 3.9-fold, respectively, in females, compared to modest increases in males. Conclusions: Female Syrian hamsters exhibit heightened vulnerability to Ang II-induced hypertension and renal damage compared to males, marked by exaggerated blood pressure elevation, enhanced renal inflammation, and suppression of classical RAS components. This novel hamster model provides a unique platform for studying sex-specific mechanisms of hypertension and renal pathology, with translational relevance for subpopulations of women who are at increased risk of Ang II-dependent hypertension-associated renal disease.
The PTP4A3 inhibitor KVX-053 reduces Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) virulence, inflammation, and development of acute lung injury in K18-hACE2 mice
Colunga-Biancatelli, Ruben M. L.; Solopov, Pavel A.; Woodson, Caitlin M.; Allen, Irving C.; Akhrymuk, Ivan; Akhrymuk, Maryna; Heath, Brittany N.; Ivester, Hannah M.; Day, Tierney; Austin, Dan E.; Kehn-Hall, Kylene; Lazo, John S.; Sharlow, Elizabeth R.; Catravas, John D. (2025-10-28)
Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has caused a global health crisis, marked by high transmissibility and virulence. Despite widespread vaccination efforts, effective treatments for COVID-19, particularly for severe cases leading to Acute Respiratory Distress Syndrome (ARDS), remain limited. This study investigates the efficacy of KVX-053, a protein tyrosine phosphatase type IVA (PTP4A3) small molecule inhibitor, in modulating SARS-CoV-2-induced inflammation and lung injury using in vitro cell models and in vivo K18-hACE2 transgenic mice. KVX-053 reduced in vitro pro-inflammatory cytokine expression, including TNFα, CXCL10, and CXCL11, without impacting viral replication or cell viability. K18-hACE2 mice treated with KVX-053 demonstrated marked improvement in clinical scores and reduced histological evidence of lung injury compared to untreated SARS-CoV-2-infected controls. KVX-053 mitigated the activation of key inflammatory mediators in the lung, including NLRP3 inflammasomes, IL-6, and phosphorylated STAT3, effectively curbing the “cytokine storm” associated with severe COVID-19. Importantly, treatment preserved lung parenchymal integrity, reduced edema, and minimized macrophage infiltration. Our findings highlight PTP4A3 as a potential critical regulator of the inflammatory response during SARS-CoV-2 infection. KVX-053, a potent and selective PTP4A3 inhibitor, emerges as a promising host-directed therapeutic strategy for mitigating ARDS and inflammation-driven lung injury in SARS-CoV-2 and potentially other respiratory viral infections. Future studies are required to optimize dosing strategies, elucidate precise molecular mechanisms, and validate these findings in clinical settings.
Immune Evasion by the NSs Protein of Rift Valley Fever Virus: A Viral Houdini Act
Petraccione, Kaylee; Omichinski, James G.; Kehn-Hall, Kylene (MDPI, 2025-10-21)
Rift Valley fever virus (RVFV) is a negative-sense arbovirus that causes several severe diseases, including hemorrhagic fever in ruminants and humans. There are currently no FDA-approved vaccines or therapeutics for RVFV. The viral nonstructural protein NSs acts like a molecular Harry Houdini, the world-famous escape artist, to help the virus evade the host’s innate immune response and serves as the main virulence factor of RVFV. In this review, we discuss the molecular mechanisms by which NSs interacts with multiple factors to modulate host processes, evade the host immune response, and facilitate viral replication. The impact of NSs mutations that cause viral attenuation is also discussed. Understanding the molecular mechanisms by which NSs evades the host innate immune response is crucial for developing novel therapeutics and vaccines targeting RVFV.

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