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Background: Myelofibrosis often lacks an identifiable cause in dogs. In humans, most primary myelofibrosis cases develop secondary to driver mutations in JAK2, CALR, or MPL. Objectives: To determine the prevalence of variants in JAK2, CALR, or MPL candidate regions in dogs with myelofibrosis and in healthy dogs. Animals: Twenty‐six dogs with myelofibrosis that underwent bone marrow biopsy between 2010 and 2018 and 25 control dogs matched for age, sex, and breed. Methods: Cross‐sectional study. Amplicon sequencing of JAK2 exons 12 and 14, CALR exon 9, and MPL exon 10 was performed on formalin‐fixed, decalcified, paraffin‐embedded bone marrow (myelofibrosis) or peripheral blood (control) DNA. Somatic variants were categorized as likely‐benign or possibly‐pathogenic based on predicted impact on protein function. Within the myelofibrosis group, hematologic variables and survival were compared by variant status (none, likely‐benign only, and ≥1 possibly‐pathogenic). The effect of age on variant count was analyzed using linear regression. Results: Eighteen of 26 (69%) myelofibrosis cases had somatic variants, including 9 classified as possibly‐pathogenic. No somatic variants were detected in controls. Within the myelofibrosis group, hematologic variables and survival did not differ by variant status. The number of somatic variants per myelofibrosis case increased with age (estimate, 0.69; SE, 0.29; P =.03). Conclusions and Clinical Importance: Somatic variants might initiate or perpetuate myelofibrosis in dogs. Our findings suggest the occurrence of clonal hematopoiesis in dogs, with increasing incidence with age, as observed in humans. [ABSTRACT FROM AUTHOR]

Doxorubicin (DOX) is a chemotherapeutic agent that has been reported to cause nephrotoxicity in rodent models and to a lesser degree in cancer patients. Female rodents have been shown to be protected against several features of DOX-induced nephrotoxicity. Nevertheless, the underlying mechanisms of this sexual dimorphism are not fully elucidated. Therefore, in the current study, we investigated the sex and time-dependent changes in pathological lesions as well as apoptotic and fibrotic markers in response to acute DOX-induced nephrotoxicity. We also determined the effect of acute DOX treatment on the renal expression of the sexually dimorphic enzyme, soluble epoxide hydrolase (sEH), since inhibition of sEH has been shown to protect against DOX-induced nephrotoxicity. Acute DOX-induced nephrotoxicity was induced by a single intra-peritoneal injection of 20 mg/kg DOX to male and female adult C57Bl/6 mice. The kidneys were isolated 1, 3 and 6 days after DOX administration. Histopathology assessment, gene expression of the apoptotic marker, BAX, protein expression of the fibrotic marker, transforming growth factor-β (TGF-β), and gene and protein expression of sEH were assessed. DOX administration caused more severe pathological lesions as well as higher induction of the apoptotic and fibrotic markers in kidneys of male than in female mice. Intriguingly, DOX inhibited sEH protein expression in kidneys of male mice sacrificed at 3 and 6 days following administration, suggesting that induction of sEH is not necessary for acute DOX-induced nephrotoxicity. However, DOX-induced inhibition of renal sEH in male mice may protect the kidney from further DOX-induced injury in a negative feedback mechanism. We also observed lower constitutive expressions of TGF-β and sEH in the kidney of female mice which may contribute, at least in part, to sexual dimorphism of DOX-induced nephrotoxicity. [ABSTRACT FROM AUTHOR]

OBJECTIVE To describe cytologic characteristics of renal fine-needle aspirate (FNA) samples from dogs, evaluate proportions of cytologic specimens deemed adequate for interpretation (diagnostic yield), assess diagnostic utility of cytologic examination for neoplastic and nonneoplastic diseases, and characterize ultrasonographic features of evaluated kidneys to determine whether the imaging characteristics could be used to inform cytologic interpretations. DESIGN Retrospective, observational study. SAMPLE 102 cytologic specimens and 97 ultrasonographic studies from 100 dogs. PROCEDURES Medical records were reviewed to identify dogs that underwent ultrasound-guided renal FNA. Slides were categorized as adequate or inadequate for interpretation; adequate slides were used for retrospective cytologic diagnosis. Sensitivity, specificity, and predictive values of cytologic examination for detection of neoplastic and nonneoplastic conditions were calculated by comparison with histologic or lymphoid cell clonality assay results. Ultrasonographic characteristics of neoplastic and nonneoplastic renal lesions were described. RESULTS 74 of 102 (72%) specimens had slides adequate for interpretation; 26 were included in the diagnostic accuracy analysis. Sensitivity of cytologic examination was 78% and 50% for detection of neoplastic and nonneoplastic conditions, respectively, with specificities of 50% and 77%, respectively; sensitivity for detection of lymphoma was 100%. Ultrasonographic appearance of kidneys with confirmed neoplasia varied; masses were most commonly found in kidneys with carcinoma (5/5), lymphoma (5/7), or other neoplasia (3/4) and absent in kidneys with nonneoplastic conditions (n = 5). CONCLUSIONS AND CLINICAL RELEVANCE Renal FNA specimens were adequate for interpretation at rates comparable with those reported for other organs and were considered clinically useful for diagnosis of neoplasia. Imaging characteristics may potentially aid differentiation between neoplastic and nonneoplastic lesions; however, further investigation is needed. [ABSTRACT FROM AUTHOR]

Activation of the classical nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB) pathway is a common molecular event observed in both human and canine diffuse large B-cell lymphoma (DLBCL). Although the oncogenic potential of the alternative NFκB pathway (ANFκBP) has also been recently identified in DLBCL, its precise role in tumor pathogenesis and potential as a treatment target is understudied. We hypothesized that up-regulation of the ANFκBP plays an important role in the proliferation and survival of canine DLBCL cells, and we demonstrate that the ANFκBP is constitutively active in primary canine DLBCL samples and a cell line (CLBL1). We further demonstrate that a small interfering RNA inhibits the activation of the NFκB pathway and induces apoptosis in canine DLBCL cells. In conclusion, the ANFκBP facilitates survival of canine DLBCL cells, and thus, dogs with spontaneous DLBCL can provide a useful large animal model to study therapies targeting the ANFκBP. [ABSTRACT FROM PUBLISHER]

Background: There is inconclusive evidence about the role of sex as a risk factor for doxorubicin (DOX)-induced cardiotoxicity. Recent experimental studies have shown that adult female rats are protected against DOX-induced cardiotoxicity. However, the mechanisms of this sexual dimorphism are not fully elucidated. We have previously demonstrated that DOX alters the expression of several cytochrome P450 (CYP) enzymes in the hearts of male rats. Nevertheless, the sex-dependent effect of DOX on the expression of CYP enzymes is still not known. Therefore, in the present study, we determined the effect of acute DOX exposure on the expression of CYP genes in the hearts of both male and female C57Bl/6 mice. Methods: Acute DOX cardiotoxicity was induced by a single intraperitoneal injection of 20 mg/kg DOX in male and female adult C57Bl/6 mice. Cardiac function was assessed 5 days after DOX exposure by trans-thoracic echocardiography. Mice were euthanized 1 day or 6 days after DOX or saline injection. Thereafter, the hearts were harvested and weighed. Heart sections were evaluated for pathological lesions. Total RNA was extracted and expression of natriuretic peptides, inflammatory and apoptotic markers, and CYP genes was measured by real-time PCR. Results: Adult female C57Bl/6 mice were protected from acute DOX-induced cardiotoxicity as they show milder pathological lesions, less inflammation, and faster recovery from DOX-induced apoptosis and DOX-mediated inhibition of beta-type natriuretic peptide. Acute DOX exposure altered the gene expression of multiple CYP genes in a sex-dependent manner. In 24 h, DOX exposure caused male-specific induction of Cyp1b1 and female-specific induction of Cyp2c29 and Cyp2e1. Conclusions: Acute DOX exposure causes sex-dependent alteration of cardiac CYP gene expression. Since cardiac CYP enzymes metabolize several endogenous compounds to biologically active metabolites, sex-dependent alteration of CYP genes may play a role in the sexual dimorphism of acute DOX-induced cardiotoxicity. [ABSTRACT FROM AUTHOR]

Case Description-A 9-year-old castrated male mixed-breed dog and a 7-year-old spayed female Boston Terrier, with clinical histories of a liver mass (dog 1) and bloody vomitus, diarrhea, and weight loss (dog 2), respectively, were referred for further evaluation. Clinical Findings-At the time of referral, each dog had differing laboratory abnormalities; however, the serum total protein and globulin concentrations were within reference range in both dogs. Cytologic examination of fine-needle aspirates obtained from affected organs (a liver mass [dog 1] and enlarged submandibular lymph node [dog 2]) revealed 2 main nucleated cell types: atypical lymphoid cells and lesser numbers of Mott cells. With the use of serum immunofixation electrophoresis and serum immunoglobulin quantification, a monoclonal immunoglobulin protein was identified in both dogs and a final diagnosis of secretory B-cell lymphoma with Mott cell differentiation (MCL) was made. Treatment and Outcome-Both dogs received chemotherapy for their disease. The first dog was euthanized 8.5 months after diagnosis because of acute respiratory distress of unknown etiology, and the second was euthanized 7 days after diagnosis for worsening clinical disease and quality of life. Clinical Relevance-To our knowledge, this report is the first of a secretory form of MCL in dogs. Findings indicate that in dogs with suspect MCL, even in patients that lack characteristic hyperproteinemia or hyperglobulinemia, serum protein content should be fully evaluated for the presence of a monoclonal immunoglobulin protein. Such an evaluation that uses immunofixation electrophoresis and immunoglobulin quantification will aid in the diagnosis of MCL in dogs. [ABSTRACT FROM AUTHOR]

Chronic wasting disease (CWD) is a prion disease affecting captive and free-ranging cervids (e.g. deer, elk, and moose). The mechanisms of CWD transmission are poorly understood, though bodily fluids are thought to play an important role. Here we report the presence of infectious prions in the urine and saliva of deer with chronic wasting disease (CWD). Prion infectivity was detected by bioassay of concentrated, dialyzed urine and saliva in transgenic mice expressing the cervid PrP gene (Tg[CerPrP] mice). In addition, PrPCWD was detected in pooled and concentrated urine by protein misfolding cyclic amplification (PMCA). The concentration of abnormal prion protein in bodily fluids was very low, as indicated by: undetectable PrPCWD levels by traditional assays (western blot, ELISA) and prolonged incubation periods and incomplete TSE attack rates in inoculated Tg(CerPrP) mice (373±3days in 2 of 9 urine-inoculated mice and 342±109 days in 8 of 9 salivainoculated mice). These findings help extend our understanding of CWD prion shedding and transmission and portend the detection of infectious prions in body fluids in other prion infections. [ABSTRACT FROM AUTHOR]

Case Description—A 16-week-old female Boxer that had been treated for 5 weeks with trimethoprim-sulfamethoxazole and chloramphenicol because of aspiration pneumonia was evaluated for bilaterally symmetric masses in the subcutaneous tissues of the ventral neck, in the region of the larynx. Clinical Findings—Fine-needle aspirates were obtained from the neck masses; cytologic examination revealed well-differentiated thyroid epithelial tissue. A blood sample was collected for serum biochemical and thyroid function analyses. Mild hyperphosphatemia, severe hypercholesterolemia, mild hyperkalemia, and a mild increase in creatine kinase activity were identified. Serum concentration of total thyroxine was less than the lower reference limit, and that of thyroid-stimulating hormone was greater than the upper reference limit. Findings were consistent with a diagnosis of clinical hypothyroidism in a skeletally immature dog. Treatment and Outcome—Treatment with trimethoprim-sulfamethoxazole was discontinued. The dog was reevaluated 3 weeks later, at which time the neck masses were markedly decreased in size. Serum concentrations of cholesterol and potassium were lower; serum concentrations of total thyroxine and thyroid-stimulating hormone were near or within respective reference ranges. Age-appropriate increases in serum phosphorus concentration and serum alkaline phosphatase activity were also detected. Clinical Relevance—To the authors' knowledge, this is the first report of antimicrobial-induced goiter in a dog. Cytologic examination of fine-needle aspirates and interpretation of data from serum biochemical and thyroid function analyses were needed to obtain a definitive diagnosis. Practitioners should include goiter among the differential diagnoses for ventral neck swellings in young dogs receiving potentiated sulfonamide antimicrobials. [ABSTRACT FROM AUTHOR]

Cancer-related cognitive impairment (CRCI) is a consequence of chemotherapy and extracranial radiation therapy (ECRT). Our prior work demonstrated gliosis in the brain following ECRT in SKH1 mice. The signals that induce gliosis were unclear. Right hindlimb skin from SKH1 mice was treated with 20 Gy or 30 Gy to induce subclinical or clinical dermatitis, respectively. Mice were euthanized at 6 h, 24 h, 5 days, 12 days, and 25 days post irradiation, and the brain, thoracic spinal cord, and skin were collected. The brains were harvested for spatial proteomics, immunohistochemistry, Nanostring nCounter® glial profiling, and neuroinflammation gene panels. The thoracic spinal cords were evaluated by immunohistochemistry. Radiation injury to the skin was evaluated by histology. The genes associated with neurotransmission, glial cell activation, innate immune signaling, cell signal transduction, and cancer were differentially expressed in the brains from mice treated with ECRT compared to the controls. Dose-dependent increases in neuroinflammatory-associated and neurodegenerative-disease-associated proteins were measured in the brains from ECRT-treated mice. Histologic changes in the ECRT-treated mice included acute dermatitis within the irradiated skin of the hindlimb and astrocyte activation within the thoracic spinal cord. Collectively, these findings highlight indirect neuronal transmission and glial cell activation in the pathogenesis of ECRT-related CRCI, providing possible signaling pathways for mitigation strategies. [ABSTRACT FROM AUTHOR]

Recessive dystrophic epidermolysis bullosa is a rare genodermatosis caused by a mutation of the Col7a1 gene. The Col7a1 gene codes for collagen type VII protein, a major component of anchoring fibrils. Mutations of the Col7a1 gene can cause aberrant collagen type VII formation, causing an associated lack or absence of anchoring fibrils. This presents clinically as chronic blistering, scarring, and fibrosis, often leading to the development of cutaneous squamous cell carcinoma. Patients also experience persistent pain and pruritus. Pain management and supportive bandaging remain the primary treatment options. The pathology of recessive dystrophic epidermolysis bullosa was first described in the 1980s, and there has since been a multitude of encouraging treatment options developed. However, in vivo research has been hindered by inadequate models of the disease. The various mouse models in existence possess longevity and surface area constraints, or do not adequately model a normal human disease state. In this paper, we describe a novel rat model of recessive dystrophic epidermolysis bullosa that offers an alternative to previous murine models. An 8-base pair deletion was induced in the Col7a1 gene of Lewis rats, which was subsequently found to cause a premature stop codon downstream. Homozygous mutants presented with a fragile and chronically blistered phenotype postnatally. Further histological analysis revealed subepidermal clefting and the absence of anchoring fibrils. The generation of this novel model offers researchers an easily maintained organism that possesses a larger surface area for experimental topical and transfused therapies to be tested, which may provide great utility in the future study of this debilitating disease. [ABSTRACT FROM AUTHOR]

Objectives: Approximately 25% of Americans suffer from laryngopharyngeal reflux (LPR), a disease for which no effective medical therapy exists. Pepsin is a predominant source of damage during LPR and a key therapeutic target. Fosamprenavir (FOS) inhibits pepsin and prevents damage in an LPR mouse model. Inhaled FOS protects at a lower dose than oral; however, the safety of inhaled FOS is unknown and there are no inhalers for laryngopharyngeal delivery. A pre‐Good Lab Practice (GLP) study of inhaled FOS was performed to assess safety and computational fluid dynamics (CFD) modeling used to predict the optimal particle size for a laryngopharyngeal dry powder inhaler (DPI). Methods: Aerosolized FOS, amprenavir (APR), or air (control) were provided 5 days/week for 4 weeks (n = 6) in an LPR mouse model. Organs (nasal cavity, larynx, esophagus, trachea, lung, liver, heart, and kidney) were assessed by a pathologist and bronchoalveolar lavage cytokines and plasma cardiotoxicity markers were assessed by Luminex assay. CFD simulations were conducted in a model of a healthy 49‐year‐old female. Results: No significant increase was observed in histologic lesions, cytokines, or cardiotoxicity markers in FOS or APR groups relative to the control. CFD predicted that laryngopharyngeal deposition was maximized with aerodynamic diameters of 8.1–11.5 μm for inhalation rates of 30–60 L/min. Conclusions: A 4‐week pre‐GLP study supports the safety of inhaled FOS. A formal GLP assessment is underway to support a phase I clinical trial of an FOS DPI for LPR. Level of Evidence: NA. [ABSTRACT FROM AUTHOR]

Background: Quantitative bacterial culture and susceptibility testing is the gold standard diagnostic for determining bacterial urinary tract infection. Transport of samples to external reference laboratories is common practice in veterinary medicine. Objective: To compare bacterial culture and susceptibility results from clinical urine samples when streak plate inoculation is performed immediately after sample collection versus after transport to a reference laboratory. To determine the clinical implications of discrepant culture results. Animals One hundred and ninety‐four canine and 45 feline urine samples that were submitted for urinalysis and urine culture and susceptibility testing. Methods: This was a prospective, cross‐sectional study. Streak plate inoculations were performed on urine samples immediately after collection and also after transport to a reference laboratory. Samples were stored in plain sterile tubes and refrigerated up to 24 hours before transport. Culture results were compared, and discordant results were evaluated for clinical relevance. Signalment, comorbidities, lower urinary tract signs, and antimicrobial history were recorded. Results: Kappa coefficient for agreement between plating methods was 0.884. Twenty‐two (71%) of 31 discrepant results were determined to have no clinical impact. Though 35% of clean midstream samples had discrepant culture results, only 8% of these had clinical impact. Conversely, 8.6% from cystocentesis were discrepant, but 41% of these had clinical impact. Conclusions and Clinical Importance: Provided urine samples are stored and transported appropriately, the immediate preplating of urine for culture and susceptibility testing is unnecessary in the majority of cases. Despite more discrepancies in plating methods for midstream samples, the minority were of clinical importance. [ABSTRACT FROM AUTHOR]

Cancer survivors experience cancer-related cognitive impairment (CRCI) secondary to treatment. Chemotherapy and radiation therapy independently contribute to cognitive dysfunction; however, the underlying mechanisms leading to dysfunction remain unclear. We characterized brain gene expression changes in a mouse model of CRCI to identify the mechanistic underpinnings. Eleven-to-twelve-week-old SKH1 mice were treated with doxorubicin (DOX), hindlimb radiation (RT), concurrent hindlimb radiation and doxorubicin (DOX-RT), or no treatment (control). Sixteen days following treatment, gene expression was measured from murine brains using the NanoString nCounter® glial profiling panel. Gene expression was normalized and compared between groups. No two groups shared the same expression pattern, and only Gnb1 and Srpr were upregulated in multiple treatment groups. Brains from DOX-treated mice had upregulated Atf2, Atp5b, Gnb1, Rad23b, and Srpr and downregulated Sirt5 expression compared to control brains. Brains from RT-treated mice demonstrated increased Abcg2 and Fgf2 and decreased C1qa and C1qb expression compared to control brains. Brains from DOX-RT-treated mice had upregulated Adar, E2f3, Erlec1, Gnb1, Srpr, Vim, and Pdgfra expression and downregulated Rock2 and Inpp5f expression compared to control brains. The gene expression changes demonstrated here highlight roles for neuronal transmission and oxidative stress in the pathogenesis of doxorubicin-related CRCI and inflammation in RT-related CRCI. [ABSTRACT FROM AUTHOR]

Background: Accurate identification of eosinophils in the gastrointestinal (GI) tract of dogs with eosinophilic GI disease (EGID) by histological evaluation is challenging. The currently used hematoxylin and eosin (H&E) staining method detects intact eosinophils but does not detect degranulated eosinophils, thus potentially underrepresenting the number of infiltrating eosinophils. Objective: To develop a more sensitive method for identifying and quantifying both intact and degranulated eosinophils to diagnose EGID more accurately. Methods: Endoscopically obtained paraffin‐embedded intestinal biopsy specimens from dogs with GI signs were examined. The study groups were dogs with eosinophilic enteritis (EE), lymphoplasmacytic and mixed enteritis, and control dogs with GI signs but no histologic changes on tissue sections. Consecutive sections were immunolabeled with monoclonal antibodies (mAbs) against the eosinophil granule protein eosinophil peroxidase (Epx) and stained by H&E, respectively. The number of eosinophils was manually quantified and classified as intact or degranulated. Results: The number of intact eosinophils detected in Epx mAb‐labeled duodenal sections was significantly higher compared with that in H&E‐stained sections, with a similar relationship noted in the colon and stomach. The Epx mAb allowed the unique assessment of eosinophil degranulation. The number of intact and degranulated eosinophils was significantly higher in duodenal lamina propria of the EE and mixed group compared to the control group. Conclusion: Immunohistochemical detection of Epx provides a more precise method to detect GI tract eosinophils compared to H&E staining and could be used as an alternative and reliable diagnostic tool for assessment of biopsy tissues from dogs with EGID. [ABSTRACT FROM AUTHOR]

Sulfasalazine (SAS) is a repurposed antitumor drug which inhibits the proliferation and survival of cancer cells by inhibiting the xCT cellular antioxidant system. Recent clinical studies have shown that, due to poor bioavailability, the antitumor effects of SAS monotherapy are minimal. Therefore, we hypothesized that DSF, another repurposed drug that has demonstrated anticancer effects, or its complex with copper (DSF-copper, DSF-Cu) could potentiate the antilung cancer effects of SAS. Exposure of non-small cell lung cancer cells to therapeutically achievable concentrations of SAS-induced low-to-moderate cytotoxic effects (20–40% reduction in cell viability) and, unexpectedly, induced the antioxidant protein NRF2 and its downstream effectors xCT and ALDH1A1. However, combinations of SAS and DSF-Cu, but not SAS and DSF, induced a significantly higher cytotoxic effect (64–88% reduction in cell viability), apoptosis and generation of mitochondrial reactive oxygen species as compared with SAS or DSF-Cu alone. Moreover, DSF-Cu abrogated SAS-induced NRF2, xCT and ALDH1A1 expression. In a mouse model of lung tumor, SAS + DSF-Cu showed a higher efficacy than the individual drugs in reducing the number and size of tumors as well as the incidence and multiplicity of lung adenocarcinoma. Taken together, our findings indicate that the observed antilung cancer effects of SAS plus DSF-Cu are mediated, at least in part, via impairment of reactive oxygen species defense and -enhancement of oxidative stress and provide evidence for the preventive/therapeutic potential of this combinatorial approach against lung cancer. [ABSTRACT FROM AUTHOR]

Adult-onset primary hypothyroidism is commonly caused by iatrogenic or autoimmune mechanisms; whether other factors might also contribute to adult hypothyroidism is unclear. Cellular Retinoic-Acid-Binding Protein 1 (CRABP1) is a mediator for Non-canonical signalling of all-trans retinoic acid (atRA). CRABP1 Knockout (CKO) mice develop and reproduce normally but begin to exhibit primary hypothyroidism in adults (~3 months old) including increased body weight, decreased body temperature, reduced plasma levels of triiodothyronine and thyroxine, and elevated levels of thyroid-stimulating hormone. Histopathological and gene expression studies reveal significant thyroid gland morphological abnormalities and altered expression of genes involved in thyroid hormone synthesis, transport, and metabolism in the CKO thyroid gland at ~6 months old. These significantly affected genes in CKO mice are also found to be genetically altered in human patients with hypothyroidism which could result in a loss of function, supporting the clinical relevance of CKO mice in humans with hypothyroidism. This study identifies, for the first time, an important role for CRABP1 in maintaining the health of the thyroid gland in adults and reports that CKO mice may provide an experimental animal model for studying the mechanisms underlying the development of adult hypothyroidism in humans. [ABSTRACT FROM AUTHOR]

It is well established that Cholangiocarcioma (CCA) drug resistance plays a crucial role in the spread and survival of cancer cells. The major enzyme in the nicotinamide-adenine dinucleotide (NAD+)-mediated pathways, nicotinamide phosphoribosyltransferase (NAMPT), is essential for cancer cell survival and metastasis. Previous research has shown that the targeted NAMPT inhibitor FK866 reduces cancer cell viability and triggers cancer cell death; however, whether FK866 affects CCA cell survival has not been addressed before. We show herein that NAMPT is expressed in CCA cells, and FK866 suppresses the capacity of CCA cells to grow in a dose-dependent manner. Furthermore, by preventing NAMPT activity, FK866 significantly reduced the amount of NAD+ and adenosine 5′-triphosphate (ATP) in HuCCT1, KMCH, and EGI cells. The present study's findings further show that FK866 causes changes in mitochondrial metabolism in CCA cells. Additionally, FK866 enhances the anticancer effects of cisplatin in vitro. Taken together, the results of the current study suggest that the NAMPT/NAD+ pathway may be a possible therapeutic target for CCA, and FK866 may be a useful medication targeting CCA in combination with cisplatin. [ABSTRACT FROM AUTHOR]

Irreversible cardiotoxicity limits the clinical application of doxorubicin (DOX). DOX-induced cardiotoxicity has been associated with induction of senescence and activation of the p38 MAPK pathway. Losmapimod (LOSM), an orally active p38 MAPK inhibitor, is an anti-inflammatory agent with cardioprotective effects. Nevertheless, the effect of LOSM against DOX-induced cardiotoxicity has not been reported. In this study, we determined the effects of LOSM on DOX-induced chronic cardiotoxicity in C57BL/6 N mice. Five-week-old C57BL/6 N mice were fed diet containing LOSM (estimated daily intake 12 mg/kg/day) or a control diet for four days. Thereafter, mice were randomized to receive six weekly intraperitoneal injections of either DOX (4 mg/kg) or saline. Three days after the last injection, cardiac function was assessed by trans-thoracic echocardiography. Activation of p38, JNK, and ERK1/2 MAPKs were assessed by immunoblotting in the heart and liver. Gene expressions of senescence, inflammatory, oxidative stress, and mitochondrial function markers were quantified using real-time PCR and serum inflammatory markers were assessed by Luminex. Our results demonstrated that LOSM attenuated p38 MAPK activation, ameliorated DOX-induced cardiac dysfunction, and abrogated DOX-induced expression of the senescence marker p21Cip1. Additionally, LOSM demonstrated anti-inflammatory effects, with reduced cardiac Il-1α and Il-6 gene expression in DOX-treated mice. Systemic inflammation, assessed by serum cytokine levels, showed decreased IL-6 and CXCL1 in both DOX-treated mice and mice on LOSM diet. LOSM significantly increased mitofusin2 gene expression, which may enhance mitochondrial fusion. These findings underscore the potential therapeutic efficacy of p38 MAPK inhibition, exemplified by LOSM, in ameliorating DOX-induced cardiotoxicity, senescence, and inflammation. [ABSTRACT FROM AUTHOR]

Spinocerebellar ataxia type 7 (SCA7) is a neurodegenerative disease caused by a trinucleotide CAG repeat. SCA7 predominantly causes a loss of photoreceptors in the retina and Purkinje cells of the cerebellum. Severe infantile-onset SCA7 also causes renal and cardiac irregularities. Previous reports have shown that SCA7 results in increased susceptibility to DNA damage. Since DNA damage can lead to accumulation of senescent cells, we hypothesized that SCA7 causes an accumulation of senescent cells over the course of disease. A 140-CAG repeat SCA7 mouse model was evaluated for signs of disease-specific involvement in the kidney, heart, and cerebellum, tissues that are commonly affected in the infantile form. We found evidence of significant renal abnormality that coincided with an accumulation of senescent cells in the kidneys of SCA7140Q/5Q mice, based on histology findings in addition to RT-qPCR for the cell cycle inhibitors p16Ink4a and p21Cip1 and senescence-associated ß-galactosidase (SA-ßgal) staining, respectively. The Purkinje layer in the cerebellum of SCA7140Q/5Q mice also displayed SA-ßgal+ cells. These novel findings offer evidence that senescent cells accumulate in affected tissues and may possibly contribute to SCA7's specific phenotype. [ABSTRACT FROM AUTHOR]

Although both preclinical and clinical studies have suggested that myo-inositol (MI) may be a safe and effective lung cancer chemopreventive agent, its efficacy is moderate. To test whether the chemopreventive agents iloprost (IL) or rapamycin enhance the lung tumor inhibitory effects of MI, A/J mice were treated with the tobacco smoke carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and, beginning one week after the end of NNK treatment, given MI, IL, rapamycin, MI + IL or MI + rapamycin for 17 weeks. Analyses of the number and size of tumors on the surface of the lung have indicated that MI, IL, rapamycin, MI + IL and MI + rapamycin reduced the multiplicity of NNK-induced lung tumors by 41, 34, 46, 79 and 67%, respectively, and larger tumors (lung tumors with a diameter of 1–2 or >2 mm) were absent in the MI + IL and MI + rapamycin groups. These results clearly indicated that MI + IL and MI + rapamycin are more effective than MI alone in inhibiting the formation and growth of lung tumors. Assessment of the immunomodulatory effects of the drugs showed that whereas MI + rapamycin and MI + IL increased the infiltration of lung tumors by CD4+ and CD8+ T cells, MI + rapamycin reduced the expression of the immune checkpoint protein programmed-death ligand-1 (PD-L1). Moreover, all treatments, except IL, increased apoptosis, whereas cell proliferation was markedly suppressed in all treated groups. In summary, these results suggest that IL and rapamycin could enhance the efficacy of MI in lung cancer chemoprevention trials. [ABSTRACT FROM AUTHOR]

Adult immunocompetent male C57Bl/6 mucopolysaccharidosis, type I (MPSI) mice develop aortic insufficiency (AI), dilated ascending aortas and decreased cardiac function, findings not observed in immune incompetent adult male NSG MPSI mice. We sought to determine why. Cardiac ultrasound measurements of ascending aorta and left ventricular dimensions and Doppler interrogation for AI were performed in 6-month-old male B6 MPSI (N = 12), WT (N = 6), NSG MPSI (N = 8), NSG (N = 6) mice. Urinary glycosaminoglycans, RNA sequencing with quantitative PCR were performed and aortic pathology assessed by routine and immunohistochemical staining on subsets of murine aortas. Ascending aortic diameters were significantly greater, left ventricular function significantly decreased, and AI significantly more frequent in B6 MPSI mice compared to NSG MPSI mice (p < 0.0001, p = 0.008 and p = 0.02, respectively); NSG and B6 WT mice showed no changes. Urinary glycosaminoglycans were significantly greater in B6 and NSG MPSI mice and both were significantly elevated compared to WT controls (p = 0.003 and p < 0.0001, respectively). By RNA sequencing, all 11 components of the inflammasome pathway were upregulated in B6 MUT, but only Aim2 and Ctsb in NSG MUT mice and none in WT controls. Both B6 and NSG MUT mice demonstrated variably-severe intramural inflammation, vacuolated cells, elastin fragmentation and disarray, and intense glycosaminoglycans on histological staining. B6 MPSI mice demonstrated numerous medial MAC2+ macrophages and adventitial CD3+ T-cells while MAC2+ macrophages were sparse and CD3+ T-cells absent in NSG MPSI mice. Aortic dilation, AI and decreased cardiac function occur in immunocompetent B6 MPSI male mice but not in immune incompetent NSG MPSI mice, unrelated to GAG excretion, upregulation of Ctsb , or routine histologic appearance. Upregulation of all components of the inflammasome pathway in B6 MUT, but not NSG MUT mice, and abundant medial MAC2 and adventitial CD3 infiltrates in B6, but not NSG, MPSI aortas differentiated the two strains. These results suggest that the innate and adaptive immune systems play a role in these cardiac findings which may be relevant to human MPSI. [ABSTRACT FROM AUTHOR]

Chronic wasting disease (CWD) is an emerging prion disease of free-ranging and captive cervids in North America. In this study we established a rodent model for CWD in Syrian golden hamsters that resemble key features of the disease in cervids including cachexia and infection of cardiac muscle. Following one to three serial passages of CWD from white-tailed deer into transgenic mice expressing the hamster prion protein gene, CWD was subsequently passaged into Syrian golden hamsters. In one passage line there were preclinical changes in locomotor activity and a loss of body mass prior to onset of subtle neurological symptoms around 340 days. The clinical symptoms included a prominent wasting disease, similar to cachexia, with a prolonged duration. Other features of CWD in hamsters that were similar to cervid CWD included the brain distribution of the disease-specific isoform of the prion protein, PrPSc, prion infection of the central and peripheral neuroendocrine system, and PrPSc deposition in cardiac muscle. There was also prominent PrPSc deposition in the nasal mucosa on the edge of the olfactory sensory epithelium with the lumen of the nasal airway that could have implications for CWD shedding into nasal secretions and disease transmission. Since the mechanism of wasting disease in prion diseases is unknown this hamster CWD model could provide a means to investigate the physiological basis of cachexia, which we propose is due to a prion-induced endocrinopathy. This prion disease phenotype has not been described in hamsters and we designate it as the 'wasting' or WST strain of hamster CWD. [ABSTRACT FROM AUTHOR]

Childhood cancer survivors have a high risk for premature cardiovascular diseases, mainly due to cardiotoxic cancer treatments such as doxorubicin (DOX). Psychosocial stress is a significant cardiovascular risk factor and an enormous burden in childhood cancer survivors. Although observational studies suggest that psychosocial stress is associated with cardiovascular complications in cancer survivors, there is no translationally relevant animal model to study this interaction. We established a "two-hit" model in which juvenile mice were administered DOX (4 mg/kg/week for 3 weeks), paired to a validated model of chronic subordination stress (CSS) 5 weeks later upon reaching adulthood. Blood pressure, heart rate, and activity were monitored by radio-telemetry. At the end of CSS experiment, cardiac function was assessed by echocardiography. Cardiac fibrosis and inflammation were assessed by histopathologic analysis. Gene expressions of inflammatory and fibrotic markers were determined by PCR. Juvenile exposure to DOX followed by adult-onset CSS caused cardiac fibrosis and inflammation as evident by histopathologic findings and upregulated gene expression of multiple inflammatory and fibrotic markers. Intriguingly, juvenile exposure to DOX blunted CSS-induced hypertension but not CSSinduced tachycardia. There were no significant differences in cardiac function parameters among all groups, but juvenile exposure to DOX abrogated the hypertrophic response to CSS. In conclusion, we established a translationally relevant mouse model of juvenile DOX-induced cardiotoxicity that predisposes to adult-onset stress-induced adverse cardiac remodeling. Psychosocial stress should be taken into consideration in cardiovascular risk stratification of DOX-treated childhood cancer survivors. [ABSTRACT FROM AUTHOR]

Chronic wasting disease (CWD) is a prion disease circulating in wild and farmed cervid populations throughout North America (United States and Canada), Europe (Finland, Norway, Sweden), and South Korea. CWD is a long-term threat to all cervid populations and to cervid hunting heritage, with the potential to cause substantial economic losses across multiple sectors. In North America, hunting and farming industries focused on the processing and consumption of white-tailed deer (WTD) venison are particularly vulnerable to CWD prion contamination, as millions of WTD are consumed annually. Real-time quaking-induced conversion (RT-QuIC) is a highly sensitive assay amplifying misfolded CWD prions in vitro and has facilitated CWD prion detection in a variety of tissues and excreta. To date, no study has comprehensively examined CWD prion content across bulk skeletal muscle tissues harvested from individual CWD infected WTD. Here, we use RT-QuIC to characterize prion-seeding activity in a variety of skeletal muscles from both wild and farmed CWD-positive WTD. We successfully detected CWD prions in muscles commonly used for consumption (e.g., backstrap, tenderloin, etc.) as well as within tongue and neck samples of WTD. Our results suggest that CWD prions are distributed across the skeletal muscles of infected WTD. We posit that RT-QuIC will be a useful tool for monitoring CWD prions in venison and that the method (with additional protocol optimization and high-throughput functionality) could be used to reduce and/or prevent CWD prions from entering animal and human food chains. [ABSTRACT FROM AUTHOR]

Quantitative analysis of computed tomography (CT) radiomic features is an indirect measure of tumor heterogeneity, which has been associated with prognosis in human lung carcinoma. Canine lung tumors share similar features to human lung tumors and serve as a model in which to investigate the utility of radiomic features in differentiating tumor type and prognostication. The purpose of this study was to correlate first-order radiomic features from canine pulmonary tumors to histopathologic characteristics and outcome. Disease-free survival, overall survival time and tumor-specific survival were calculated as days from the date of CT scan. Sixty-seven tumors from 65 dogs were evaluated. Fifty-six tumors were classified as primary pulmonary adenocarcinomas and 11 were non-adenocarcinomas. All dogs were treated with surgical resection; 14 dogs received adjuvant chemotherapy. Second opinion histopathology in 63 tumors confirmed the histologic diagnosis in all dogs and further characterized 53 adenocarcinomas. The median overall survival time was longer (p = 0.004) for adenocarcinomas (339d) compared to non-adenocarcinomas (55d). There was wide variation in first-order radiomic statistics across tumors. Mean Hounsfield units (HU) ratio (p = 0.042) and median mean HU ratio (p = 0.042) were higher in adenocarcinomas than in non-adenocarcinomas. For dogs with adenocarcinoma, completeness of excision was associated with overall survival (p<0.001) while higher mitotic index (p = 0.007) and histologic score (p = 0.037) were associated with shorter disease-free survival. CT-derived tumor variables prognostic for outcome included volume, maximum axial diameter, and four radiomic features: integral total, integral total mean ratio, total HU, and max mean HU ratio. Tumor volume was also significantly associated with tumor invasion (p = 0.044). Further study of radiomic features in canine lung tumors is warranted as a method to non-invasively interrogate CT images for potential predictive and prognostic utility. [ABSTRACT FROM AUTHOR]

Spondweni virus (SPONV) is the most closely related known flavivirus to Zika virus (ZIKV). Its pathogenic potential and vector specificity have not been well defined. SPONV has been found predominantly in Africa, but was recently detected in a pool of Culex quinquefasciatus mosquitoes in Haiti. Here we show that SPONV can cause significant fetal harm, including demise, comparable to ZIKV, in a mouse model of vertical transmission. Following maternal inoculation, we detected infectious SPONV in placentas and fetuses, along with significant fetal and placental histopathology, together suggesting vertical transmission. To test vector competence, we exposed Aedes aegypti and Culex quinquefasciatus mosquitoes to SPONV-infected bloodmeals. Aedes aegypti could efficiently transmit SPONV, whereas Culex quinquefasciatus could not. Our results suggest that SPONV has the same features that made ZIKV a public health risk. [ABSTRACT FROM AUTHOR]

Sex-related differences in cardiovascular diseases are highly complex in humans and model-dependent in experimental laboratory animals. The objective of this work was to comprehensively investigate key sex differences in the response to acute and prolonged adrenergic stimulation in C57Bl/6NCrl mice. Cardiac function was assessed by trans-thoracic echocardiography before and after acute adrenergic stimulation (a single sub-cutaneous dose of isoproterenol 10 mg/kg) in 15 weeks old male and female C57Bl/6NCrl mice. Thereafter, prolonged adrenergic stimulation was achieved by sub-cutaneous injections of isoproterenol 10 mg/kg/day for 14 days in male and female mice. Cardiac function and morphometry were assessed by trans-thoracic echocardiography on the 15th day. Thereafter, the mice were euthanized, and the hearts were collected. Histopathological analysis of myocardial tissue was performed after staining with hematoxylin & eosin, Masson's trichrome and MAC-2 antibody. Gene expression of remodeling and fibrotic markers was assessed by real-time PCR. Cardiac function and morphometry were also measured before and after isoproterenol 10 mg/kg/day for 14 days in groups of gonadectomized male and female mice and sham-operated controls. In the current work, there were no statistically significant differences in the positive inotropic and chronotropic effects of isoproterenol between male and female C57Bl/6NCrl. After prolonged adrenergic stimulation, there was similar degree of cardiac dysfunction, cardiac hypertrophy, and myocardial fibrosis in male and female mice. Similarly, prolonged isoproterenol administration induced hypertrophic and fibrotic genes in hearts of male and female mice to the same extent. Intriguingly, gonadectomy of male and female mice did not have a significant impact on isoproterenol-induced cardiac dysfunction as compared to sham-operated animals. The current work demonstrated lack of significant sex-related differences in isoproterenol-induced cardiac hypertrophy, dysfunction, and fibrosis in C57Bl/6NCrl mice. This study suggests that female sex may not be sufficient to protect the heart in this model of isoproterenol-induced cardiac dysfunction and underscores the notion that sexual dimorphism in cardiovascular diseases is highly model-dependent. [ABSTRACT FROM AUTHOR]

Minimally invasive techniques used to evaluate canine peripheral lymphadenopathy (PLN), including fine needle aspiration biopsy with cytological evaluation (FNAB‐C) and flow cytometry (FC), have benefits and limitations. The cell block (CB) method is an alternate processing technique in which fine needle aspirate biopsy samples are concentrated, fixed, and embedded in paraffin for routine histological processing/staining. Utilizing three observers, we determined the diagnostic value of the CB in evaluating canine PLN across six categories (non‐diagnostic, reactive, inflammatory/infectious, probable lymphoma and lymphoma, metastatic neoplasia) and correlated findings to immunophenotypic and clonal antigen receptor rearrangement results in canine nodal lymphoma. Eighty‐five paired FNAB‐C and CB samples were evaluated from canine patients presenting to the University of Minnesota Veterinary Oncology or Internal Medicine services. Diagnostic quality samples were obtained in 55/85 (65%) CB and 81/85 (95%) FNAB‐C samples, respectively, and nodal pathology impacted CB diagnostic yield. Overall percent agreement between diagnostic‐quality FNAB‐C and CB samples was 86%, but increased to 95% if the categories of lymphoma and probable lymphoma were combined. There was 100% agreement for both the diagnoses of metastatic neoplasia and reactive lymph nodes and 92% agreement for the diagnosis of lymphoma/probable lymphoma. Using immunohistochemistry (IHC), CB samples correctly immunophenotyped 22/23 (96%) cases of B‐cell lymphoma, but only 1/6 (17%) cases of T‐cell lymphoma. IHC was not completed on nine cases of lymphoproliferative disease because of insufficient cellularity. When the CB method (CBM) yielded diagnostic quality samples there was good to excellent agreement with FNAB‐C samples and CB samples were suitable for some IHC tests. [ABSTRACT FROM AUTHOR]

Established T cell dysfunction is a barrier to antitumor responses, and checkpoint blockade presumably reverses this. Many patients fail to respond to treatment and/or develop autoimmune adverse events. The underlying reason for T cell responsiveness remains elusive. Here, we show that susceptibility to checkpoint blockade is dependent on the activation status of T cells. Newly activated self-specific CD8 T cells respond to checkpoint blockade and cause autoimmunity, which is mitigated by inhibiting the mechanistic target of rapamycin. However, once tolerance is established, self-specific CD8 T cells display a gene signature comparable to tumor-specific CD8 T cells in a fixed state of dysfunction. Tolerant self-specific CD8 T cells do not respond to single or combinatorial dosing of anti-CTLA4, anti-PD-L1, anti-PD-1, anti-LAG-3, and/or anti-TIM-3. Despite this, T cell responsiveness can be induced by vaccination with cognate antigen, which alters the previously fixed transcriptional signature and increases antigen-sensing machinery. Antigenic reeducation of tolerant T cells synergizes with checkpoint blockade to generate functional CD8 T cells, which eliminate tumors without concomitant autoimmunity and are transcriptionally distinct from classic effector T cells. These data demonstrate that responses to checkpoint blockade are dependent on the activation state of a T cell and show that checkpoint blockade-insensitive CD8 T cells can be induced to respond to checkpoint blockade with robust antigenic stimulation to participate in tumor control. [ABSTRACT FROM AUTHOR]

Key Clinical Message: An 11‐year‐old female spayed Golden Retriever presented for an incidentally found liver mass. The hepatic mass and intra‐abdominal lymph nodes had a marked heterogeneous T‐cell population and far fewer numbers of small clonal B cells. This T‐cell‐rich small B‐cell lymphoma had a unique histological pattern and indolent clinical course. [ABSTRACT FROM AUTHOR]

Purpose To develop a murine total marrow irradiation (TMI) model in comparison with the total body irradiation (TBI) model. Materials and methods Myeloablative TMI and TBI were administered in mice using a custom jig, and the dosimetric differences between TBI and TMI were evaluated. The early effects of TBI/TMI on bone marrow (BM) and organs were evaluated using histology, FDG-PET, and cytokine production. TMI and TBI with and without cyclophosphamide (Cy) were evaluated for donor cell engraftment and tissue damage early after allogeneic hematopoietic cell transplantation (HCT). Stromal derived factor-1 (SDF-1) expression was evaluated. Results TMI resulted in similar dose exposure to bone and 50% reduction in dose to bystander organs. BM histology was similar between the groups. In the non-HCT model, TMI mice had significantly less acute intestinal and lung injury compared to TBI. In the HCT model, recipients of TMI had significantly less acute intestinal injury and spleen GVHD, but increased early donor cell engraftment and BM:organ SDF-1 ratio compared to TBI recipients. Conclusions The expected BM damage was similar in both models, but the damage to other normal tissues was reduced by TMI. However, BM engraftment was improved in the TMI group compared to TBI, which may be due to enhanced production of SDF-1 in BM relative to other organs after TMI. [ABSTRACT FROM AUTHOR]

Mucopolysaccharidosis type II (Hunter syndrome, MPS II) is an inherited X-linked recessive disease caused by deficiency of iduronate-2-sulfatase (IDS), resulting in the accumulation of the glycosaminoglycans (GAG) heparan and dermatan sulfates. Mouse models of MPS II have been used in several reports to study disease pathology and to conduct preclinical studies for current and next generation therapies. Here, we report the generation and characterization of an immunodeficient mouse model of MPS II, where CRISPR/Cas9 was employed to knock out a portion of the murine IDS gene on the NOD/SCID/Il2rγ (NSG) immunodeficient background. IDS −/− NSG mice lacked detectable IDS activity in plasma and all analyzed tissues and exhibited elevated levels of GAGs in those same tissues and in the urine. Histopathology revealed vacuolized cells in both the periphery and CNS of NSG-MPS II mice. This model recapitulates skeletal disease manifestations, such as increased zygomatic arch diameter and decreased femur length. Neurocognitive deficits in spatial memory and learning were also observed in the NSG-MPS II model. We anticipate that this new immunodeficient model will be appropriate for preclinical studies involving xenotransplantation of human cell products intended for the treatment of MPS II. [ABSTRACT FROM AUTHOR]

The unintended side effects of cancer treatment are increasing recognized. Among these is a syndrome of long-term neurocognitive dysfunction called cancer/chemotherapy related cognitive impairment. To date, all studies examining the cognitive impact of cancer treatment have emphasized chemotherapy. Radiation-induced bystander effects have been described in cell culture and, to a limited extent, in rodent model systems. The purpose of this study was to examine, for the first time, the impact of non-brain directed radiation therapy on the brain in order to elucidate its potential relationship with cancer/chemotherapy related cognitive impairment. To address this objective, female BALB/c mice received either a single 16 gray fraction of ionizing radiation to the right hind limb or three doses of methotrexate, once per week for three consecutive weeks. Mice were sacrificed either 3 or 30 days post-treatment and brain injury was determined via quantification of activated astrocytes and microglia. To characterize the effects of non-brain directed radiation on brain glucose metabolism, mice were evaluated by fluorodeoxygluocose positron emission tomography. A single fraction of 16 gray radiation resulted in global decreases in brain glucose metabolism, a significant increase in the number of activated astrocytes and microglia, and increased TNF-α expression, all of which lasted up to 30 days post-treatment. This inflammatory response following radiation therapy was statistically indistinguishable from the neuroinflammation observed following methotrexate administration. In conclusion, non-brain directed radiation was sufficient to cause significant brain bystander injury as reflected by multifocal hypometabolism and persistent neuroinflammation. These findings suggest that radiation induces significant brain bystander effects distant from the irradiated cells and tissues. These effects may contribute to the development of cognitive dysfunction in treated human cancer patients and warrant further study. [ABSTRACT FROM AUTHOR]

Prion diseases such as Creutzfeldt-Jakob disease in humans, bovine spongiform encephalopathy in cattle, and scrapie in sheep are fatal neurodegenerative diseases for which there is no effective treatment. The pathology of these diseases involves the conversion of a protease sensitive form of the cellular prion protein (PrPC) into a protease resistant infectious form (PrPsc or PrPres). Both in vitro (cell culture and cell free conversion assays) and in vivo (animal) studies have demonstrated the strong dependence of this conversion process on protein sequence homology between the initial prion inoculum and the host’s own cellular prion protein. The presence of non-homologous (heterologous) proteins is often inhibitory to this conversion process. We hypothesize that the presence of heterologous prion proteins from one species might therefore constitute an effective treatment for prion disease in another species. To test this hypothesis, we infected mice intracerebrally with murine adapted RML-Chandler scrapie and treated them with heterologous prion protein (purified bacterially expressed recombinant hamster prion protein) or vehicle alone. Treated animals demonstrated reduced disease associated pathology, decreased accumulation of protease-resistant disease-associated prion protein, with delayed onset of clinical symptoms and motor deficits. This was concomitant with significantly increased survival times relative to mock-treated animals. These results provide proof of principle that recombinant hamster prion proteins can effectively and safely inhibit prion disease in mice, and suggest that hamster or other non-human prion proteins may be a viable treatment for prion diseases in humans. [ABSTRACT FROM AUTHOR]

The horizontal transmission of prion diseases has been well characterized in bovine spongiform encephalopathy (BSE), chronic wasting disease (CWD) of deer and elk and scrapie of sheep, and has been regarded as the primary mode of transmission. Few studies have monitored the possibility of vertical transmission occurring within an infected mother during pregnancy. To study the potential for and pathway of vertical transmission of CWD in the native cervid species, we used a small cervid model–the polyestrous breeding, indoor maintainable, Reeves’ muntjac deer–and determined that the susceptibility and pathogenesis of CWD in these deer reproduce that in native mule and white-tailed deer. Moreover, we demonstrate here that CWD prions are transmitted from doe to fawn. Maternal CWD infection also appears to result in lower percentage of live birth offspring. In addition, evolving evidence from protein misfolding cyclic amplification (PMCA) assays on fetal tissues suggest that covert prion infection occurs in utero. Overall, our findings demonstrate that transmission of prions from mother to offspring can occur, and may be underestimated for all prion diseases. [ABSTRACT FROM AUTHOR]

The complement system has been shown to facilitate peripheral prion pathogenesis. Mice lacking complement receptors CD21/35 partially resist terminal prion disease when infected i.p. with mouse-adapted scrapie prions. Chronic wasting disease (CWD) is an emerging prion disease of captive and free-ranging cervid populations that, similar to scrapie, has been shown to involve the immune system, which probably contributes to their relatively facile horizontal and environmental transmission. In this study, we show that mice overexpressing the cervid prion protein and susceptible to CWD (Tg(cerPrP)5037 mice) but lack CD21/35 expression com-pletely resist clinical CWD upon peripheral infection. CD21/35-deficient Tg5037 mice exhibit greatly impaired splenic prion ac-cumulation and replication throughout disease, similar to CD21/35-deficient murine prion protein mice infected with mouse scrapie. TgA5037;CD21/35-/- mice exhibited little or no neuropathology and deposition of misfolded, protease-resistant prion protein associated with CWD. CD21/35 translocate to lipid rafts and mediates a strong germinal center response to prion infection that we propose provides the optimal environment for prion accumulation and replication. We further propose a potential role for CD21/ 35 in selecting prion quasi-species present in prion strains that may exhibit differential zoonotic potential compared with the parental strains. [ABSTRACT FROM AUTHOR]

A critical concern in the transmission of prion diseases, including chronic wasting disease (CWD) of cervids, is the potential presence of prions in body fluids. To address this issue directly, we exposed cohorts of CWD-naïve deer to saliva, blood, or urine and feces from CWD-positive deer. We found infectious prions capable of transmitting CWD in saliva (by the oral route) and in blood (by transfusion). The results help to explain the facile transmission of CWD among cervids and prompt caution concerning contact with body fluids in prion infections. [ABSTRACT FROM AUTHOR]

While the facile transmission of chronic wasting disease (CWD) remains incompletely elucidated, studies in rodents suggest that exposure of the respiratory mucosa may be an efficient pathway. The present study was designed to address this question in the native cervid host. Here, we demonstrate aerosol transmission of CWD to deer with a prion dose >20-fold lower than that used in previous oral inoculations. Inhalation of prions may facilitate transmission of CWD and, perhaps, other prion infections [ABSTRACT FROM AUTHOR]

Transmissible spongiform encephalopathies (TSEs), or prion diseases, are a uniformly fatal family of neurodegenerative diseases in mammals that includes chronic wasting disease (CWD) of cervids. The early and ante-mortem identification of TSE-infected individuals using conventional western blotting or immunohistochemistry (IHC) has proven difficult, as the levels of infectious prions in readily obtainable samples, including blood and bodily fluids, are typically beyond the limits of detection. The development of amplification-based seeding assays has been instrumental in the detection of low levels of infectious prions in clinical samples. In the present study, we evaluated the cerebrospinal fluid (CSF) of CWD-exposed (n=44) and naïve (n=4) deer (n=48 total) for CWD prions (PrPd) using two amplification assays: serial protein misfolding cyclic amplification with polytetrafluoroethylene beads (sPMCAb) and real-time quaking induced conversion (RT-QuIC) employing a truncated Syrian hamster recombinant protein substrate. Samples were evaluated blindly in parallel with appropriate positive and negative controls. Results from amplification assays were compared to one another and to obex immunohistochemistry, and were correlated to available clinical histories including CWD inoculum source (e.g. saliva, blood), genotype, survival period, and duration of clinical signs. We found that both sPMCAb and RT-QuIC were capable of amplifying CWD prions from cervid CSF, and results correlated well with one another. Prion seeding activity in either assay was observed in approximately 50% of deer with PrPd detected by IHC in the obex region of the brain. Important predictors of amplification included duration of clinical signs and time of first tonsil biopsy positive results, and ultimately the levels of PrPd identified in the obex by IHC. Based on our findings, we expect that both sPMCAb and RT-QuIC may prove to be useful detection assays for the detection of prions in CSF. [ABSTRACT FROM AUTHOR]