Infectious diseases are a significant issue in animal production systems, including both the dairy and beef cattle industries. Understanding and defining the genetics of infectious disease ...susceptibility in cattle is an important step in the mitigation of their impact. Collagenous lectins are soluble pattern recognition receptors that form an important part of the innate immune system, which serves as the first line of host defense against pathogens. Polymorphisms in the collagenous lectin genes have been shown in previous studies to contribute to infectious disease susceptibility, and in cattle, mutations in two collagenous lectin genes (
MBL1
and
MBL2
) are associated with mastitis. To further characterize the contribution of variation in the bovine collagenous lectins to infectious disease susceptibility, we used a pooled NGS approach to identify short nucleotide variants (SNVs) in the collagenous lectins (and regulatory DNA) of cattle with (
n
= 80) and without (
n
= 40) infectious disease. Allele frequency analysis identified 74 variants that were significantly (
p
< 5 × 10
−6
) associated with infectious disease, the majority of which were clustered in a 29-kb segment upstream of the collectin locus on chromosome 28. In silico analysis of the functional effects of all the variants predicted 11 SNVs with a deleterious effect on protein structure and/or function, 148 SNVs that occurred within potential transcription factor binding sites, and 31 SNVs occurring within potential miRNA binding elements. This study provides a detailed look at the genetic variation of the bovine collagenous lectins and identifies potential genetic markers for infectious disease susceptibility.
Background
Duodenitis‐proximal jejunitis (DPJ) is an acute sporadic gastrointestinal disorder of horses of unknown cause.
Hypothesis/Objectives
We hypothesize that Clostridium difficile toxins are ...involved in the pathogenesis of DPJ in horses. The objective of this study was to determine whether experimentally delivered C. difficile toxins cause clinical signs and histologic lesions similar to those of naturally occurring DPJ.
Animals
Six healthy mature mixed breed horses.
Methods
Experimental study: animal model of animal disease. Fasted horses were administered crude C. difficile toxins via gastroscopy and monitored for up to 48 hour. Blood was collected for complete blood cell count, biochemistry profile, and plasma fibrinogen assay, and abdominal fluid was collected for cytologic analysis and total solids before and after toxin administration. Physical examination and abdominal ultrasonography were performed throughout the study period. Tissues were collected from the gastrointestinal tract and processed for routine histologic analysis, and lesions were scored.
Results
Clinical signs were observed in 2 of 6 horses that are typical although not specific for horses with naturally occurring DPJ. Histopathologic lesions were observed in 6 of 6 horses and were similar to those reported in horses with naturally occurring DPJ. Two horses were severely affected.
Conclusions and Clinical Importance
Duodenitis‐proximal jejunitis is likely a syndrome with multiple causes that result in the same clinical and pathologic findings, and our data suggest that the toxins of C. difficile represent one cause of this syndrome. Toxin dose and variation in individual animal susceptibility might affect the clinical signs and lesions after administration of C. difficile toxins.
Lake trout Salvelinus namaycush (Walbaum) raised for stocking experienced yearly (2011–13) winter epizootics of epitheliocystis. Affected fish were dispersed on the bottom of the tank, had decreased ...feed and fright response, and mortality often reached 40%. Peak mortality occurred within 3 weeks of the appearance of clinical signs, and outbreaks typically lasted 6 weeks. Affected fish had no gross lesions but histologically had branchial epithelial necrosis and lamellar hyperplasia, with small to large numbers of scattered epithelial cells containing 10‐ to 20‐μm inclusions. A longitudinal study was undertaken of one annual outbreak, and lamellar hyperplasia was most closely associated with mortality. The number of inclusions was statistically greater (P < 0.05) before and during peak mortality, but inclusions were present in low numbers before clinical signs occurred. Results of histochemical staining, immunohistochemistry and transmission electron microscopy supported the presence of a β‐proteobacteria rather than a Chlamydiales bacterium within inclusions. PCR primers to identify Chlamydiales did not give consistent results. However, the use of universal 16S rDNA bacterial primers in conjunction with laser capture microdissection of inclusions demonstrated that a β‐proteobacteria was consistently associated with affected gills and is more likely the cause of the disease in lake trout.
X-linked spinal and bulbar muscular atrophy (SBMA; Kennedy's disease) is a polyglutamine (polyQ) disease in which the affected males suffer progressive motor neuron degeneration accompanied by signs ...of androgen insensitivity, such as gynecomastia and reduced fertility. SBMA is caused by CAG repeat expansions in the androgen receptor (AR) gene resulting in the production of AR protein with an extended glutamine tract. SBMA is one of nine polyQ diseases in which polyQ expansion is believed to impart a toxic gain-of-function effect upon the mutant protein, and initiate a cascade of events that culminate in neurodegeneration. However, whether loss of a disease protein's normal function concomitantly contributes to the neurodegeneration remains unanswered. To address this, we examined the role of normal AR function in SBMA by crossing a highly representative AR YAC transgenic mouse model with 100 glutamines (AR100) and a corresponding control (AR20) onto an AR null (testicular feminization; Tfm) background. Absence of endogenous AR protein in AR100Tfm mice had profound effects upon neuromuscular and endocrine-reproductive features of this SBMA mouse model, as AR100Tfm mice displayed accelerated neurodegeneration and severe androgen insensitivity in comparison to AR100 littermates. Reduction in size and number of androgen-sensitive motor neurons in the spinal cord of AR100Tfm mice underscored the importance of AR action for neuronal health and survival. Promoter-reporter assays confirmed that AR transactivation competence diminishes in a polyQ length-dependent fashion. Our studies indicate that SBMA disease pathogenesis, both in the nervous system and the periphery, involves two simultaneous pathways: gain-of-function misfolded protein toxicity and loss of normal protein function.
Innate immune recognition of pathogens involves various surface receptors and soluble proteins that precede agglutination, complement activation, phagocytosis, and the adaptive immune response. ...Mannan-binding lectins (MBLs), ficolins (FCNs) and surfactant protein A (SP-A) are soluble collagenous lectins that bind surface structures of various bacteria, viruses and fungi. Some single nucleotide polymorphisms (SNPs) in collagenous lectin genes of humans and other species, including pigs, have been implicated in variation in susceptibility to infectious and inflammatory diseases. In this study we determined the frequencies of 13 SNP alleles of MBL-A, MBL-C, ficolin-α, ficolin-β, and SP-A in 1324 healthy pigs and 461 pigs diagnosed with common infectious diseases at necropsy. For comparison, we also analyzed 12 other SNP alleles in several other innate immune genes, including galectins and TLRs. Several SNPs within genes encoding porcine MBL-A, MBL-C and SP-A were more frequent in pigs diagnosed at necropsy with various diseases or pathogens. These findings suggest that several collagenous lectin SNPs are associated with disease susceptibility and therefore might be genetic markers of impaired innate immune function.
Prostate cancer is an age-associated epithelial cancer, and as such, it contributes significantly to the mortality of the elderly. Senescence is one possible mechanism by which the body defends ...itself against various epithelial cancers. Senescent cells alter the microenvironment, in part, through changes to the extracellular matrix. Laminins (LMs) are extracellular proteins important to both the structure and function of the microenvironment. Overexpression of the senescence-associated gene mac25 in human prostate cancer cells resulted in increased mRNA levels of the LM α4 and β2 chains compared to empty vector control cells. The purpose of this study was to examine the effects of these senescence-induced LM chains on tumorigenicity of prostate cancer cells. We created stable M12 human prostate cancer lines overexpressing either the LM α4 or β2 chain or both chains. Increased expression of either the LM α4 or β2 chain resulted in increased in vitro migration and in vivo tumorigenicity of those cells, whereas high expression of both chains led to decreased in vitro proliferation and in vivo tumorigenicity compared to M12 control cells. This study demonstrates that senescent prostate epithelial cells can alter the microenvironment and that these changes modulate progression of prostate cancer.
Ring-necked pheasants raised on propagation farms can be severely parasitized with Syngamus trachea (gapeworm) and other parasitic worms. Fenbendazole is a highly effective benzimidazole-class ...anthelmintic that is not currently approved for game bird species in the United States. The objective of this work was to provide target animal safety data to support a label claim for fenbendazole in pheasants at 100 parts per million (ppm) in the feed for 7 consecutive days. Demonstration of safety in young pheasants and a separate demonstration of reproductive safety in adult birds were required. In the young bird study, 160 Chinese ring-necked pheasants (Phasianus colchicus, 80 males and 80 females) were fed a commercial game bird starter ration containing no antibiotics, growth promoters, or coccidiostats until day 0 of the study (approximately 21 days of age). On day 0 the birds were placed on their respective study diets containing fenbendazole at 0, 100, 300, and 500 ppm for 21 days (three times the normal treatment duration). Clinical observations were recorded twice daily. Feed consumption, feed conversion rate, and body weights were determined for each pen. Three birds from each pen were randomly selected for necropsy, histopathology, and clinical pathology. Birds were carefully examined for feathering abnormalities immediately following euthanasia. The remaining birds in each pen were submitted for drug concentration analysis so that concentrations (for low vs. high treatment levels) could be correlated with clinical observations, clinical pathology, and histologic findings. There no morbidities or mortalities after study day −1. There were no statistically significant treatment-related differences in feed consumption, feed conversion rates, body weights, serum biochemistry profiles, hematologic profiles, gross necropsy findings, histopathologic examination, and feathering. Allowable liver and muscle concentrations of fenbendazole sulfone in turkeys are 6 and 2 ppm, respectively, with a 6-hr feed withdrawal. Analysis of fenbendazole concentrations in kidney, liver, leg/thigh, and breast muscle and skin with associated fat revealed that, even at the highest dose level used and with no feed withdrawal, fenbendazole concentrations were relatively low in these tissues. These findings indicate that fenbendazole has a relatively wide margin of safety in young pheasants and that the proposed dose of 100 ppm in the feed for 7 consecutive days is well within the margin of safety. In the reproductive safety study, two large game bird farms fed fendbendazole at 100 ppm for 7 days and collected data on hatching percentage of pheasant eggs before and after treatment. Reproductive performance in hen pheasants was not adversely affected. Seguridad de Fenbendazol en faisanes comunes (Phasianus colchinus). Los faisanes comunes criados en granjas pueden ser severamente parasitados con Syngamus trachea (con sinonimia en inglés gapeworm) y otros helmintos parásitos. El fenbendazol es un antihelmíntico de la clase de los bencimidazoles, muy efectivo que no está aprobado actualmente para las especies de aves de caza en los Estados Unidos. El objetivo de este trabajo fue proporcionar datos sobre la seguridad en estas aves para apoyar una solicitud de autorización del uso de fenbendazol en faisanes con una dosis de 100 ppm en el alimento durante siete días consecutivos. Se requiere de la demostración de la seguridad en faisanes jóvenes y una demostración independiente de seguridad en la reproducción de las aves adultas. En el estudio de aves jóvenes, 160 faisanes comunes (Phasianus colchicus, 80 machos y 80 hembras) fueron alimentados con una ración de iniciación para aves de caza comercial que no contenía antibióticos, promotores del crecimiento, o coccidiostatos hasta el día cero del estudio (aproximadamente a los 21 días de edad). En el día cero las aves se colocaron en sus respectivas dietas de estudio que contenían fenbendazol en 0, 100, 300, y 500 ppm durante 21 días (tres veces la duración normal de tratamiento). Las observaciones clínicas se registraron dos veces al día. El consumo de alimento, la conversión alimenticia, y los pesos corporales se determinaron para cada corral. Tres aves de cada corral fueron seleccionados aleatoriamente para realizar necropsias, histopatología y patología clínica. Las aves fueron examinadas cuidadosamente inmediatamente después de la necropsia para detectar anormalidades en el emplume. El resto de las aves de cada corral se sometieron a análisis de la concentración del fármaco de manera que las concentraciones (niveles bajos en contra niveles altos de tratamiento) pudieran correlacionarse con observaciones clínicas, patología clínica y los hallazgos histológicos. No hubo morbilidad o mortalidad después del día −1 del estudio. No hubo diferencias estadísticamente significativas relacionadas con el tratamiento en el consumo de alimento, las tasas de conversión alimenticia, peso corporal, perfiles bioquímicos séricos, perfiles hematológicos, hallazgos macroscópicos de necropsia, examen histopatológico y el emplume. Las concentraciones permisibles en hígado y músculos de sulfona de fenbendazol en pavos son 6 ppm y 2 ppm, respectivamente, con un tiempo de retiro de 6 horas. El análisis de las concentraciones de fenbendazol en el riñón, el hígado, músculos de la pierna/muslo y pechuga y la piel con la grasa asociada revelaron que incluso con la dosis más alta utilizada y sin ningún periodo de retiro, las concentraciones fenbendazol fueron relativamente bajas en estos tejidos. Estos resultados indican que el fenbendazol tiene un margen de seguridad relativamente amplio en faisanes jóvenes y que la dosis propuesta de 100 ppm en el alimento durante siete días consecutivos se ubica dentro del margen de seguridad. En el estudio de seguridad reproductiva, dos explotaciones grandes de aves de caza proporcionaron fenbendazol a 100 ppm por siete días y se recolectaron datos sobre porcentaje de eclosión de huevos de faisán antes y después del tratamiento. El comportamiento reproductivo en las hembras de faisán no se vio afectado de manera negativa.
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