Brd4::Nutm1 fusion gene initiates NUT carcinoma in vivo.

NUT carcinoma (NC) is an aggressive cancer with no effective treatment. About 70% of NUT carcinoma is associated with chromosome translocation events that lead to the formation of a BRD4::NUTM1 fusion gene. Because the BRD4::NUTM1 gene is unequivocally cytotoxic when ectopically expressed in cell lines, questions remain on whether the fusion gene can initiate NC. Here, we report the first genetically engineered mouse model for NUT carcinoma that recapitulates the human t(15;19) chromosome translocation in mice. We demonstrated that the mouse t(2;17) syntenic chromosome translocation, forming the Brd4::Nutm1 fusion gene, could induce aggressive carcinomas in mice. The tumors present histopathological and molecular features similar to human NC, with enrichment of undifferentiated cells. Similar to the reports of human NC incidence, Brd4::Nutm1 can induce NC from a broad range of tissues with a strong phenotypical variability. The consistent induction of poorly differentiated carcinoma demonstrated a strong reprogramming activity of BRD4::NUTM1. The new mouse model provided a critical preclinical model for NC that will lead to better understanding and therapy development for NC.

West Nile Virus-Induced Drop in Egg Production in Commercial Pekin Duck Breeders.

A sudden drop in egg production in commercial poultry flocks can be economically devastating, and rapid identification of the cause often requires a combined effort between the producer, veterinarian, and pathologist. In September 2019, a 35-wk-old commercial Pekin breeder duck flock in Indiana suffered a drop in egg production from 1700 to 1000 eggs daily (41.2% drop). Again, in September 2021, three Pekin breeder duck flocks aged 32, 58, and 62 wk from the same company suffered a similar drop in egg production, with a mild increase in weekly mortality of 1.0% to 2.5%. In 2019 and in 2021, birds from affected flocks were submitted to the Veterinary Diagnostic Laboratory at Michigan State University for postmortem examination. Common gross examination findings included flaccid, shrunken, or atrophied ova (all hens), pododermatitis, airsacculitis, hepatomegaly, splenomegaly, ascites, and pallor of the left ventricle. Histopathologic examination of cerebrum, cerebellum, and brainstem revealed mild lymphocytic perivascular cuffing, vasculitis, and gliosis, suggesting viral encephalitis. In the heart, there was mild multifocal cardiomyocyte necrosis, mineralization, and infiltration by lymphocytes and macrophages. PCR for Newcastle disease virus, avian influenza virus, eastern equine encephalitis virus, and West Nile virus (WNV) was performed. Brain and heart samples were positive for WNV by PCR, and WNV antigen was detected in the cerebellum by immunohistochemistry. This is the first report to associate WNV infection with a drop in egg production in waterfowl, which are known to be important reservoir species for WNV and, as such, are generally asymptomatic.

Reporte de caso- Caída en la producción de huevo inducida por el virus del Nilo Occidental en patas reproductoras Pekín comerciales. Una caída repentina en la producción de huevos en parvadas comerciales de aves de corral puede ser económicamente devastadora, y la identificación rápida de la causa a menudo requiere un esfuerzo combinado entre el productor, el veterinario y el patólogo. En septiembre del 2019, una parvada comercial de patos Pekin reproductores de 35 semanas de edad en Indiana sufrió una caída en la producción de huevos de 1700 a 1000 huevos diarios (una caída de 41.2%). Nuevamente, en septiembre del 2021, tres parvadas de patos reproductores de Pekín de 32, 58 y 62 semanas de edad de la misma empresa sufrieron una caída similar en la producción de huevos, con un leve aumento en la mortalidad semanal de 1.0 % a 2.5 %. En 2019 y 2021, aves de las parvadas afectadas se enviaron al Laboratorio de Diagnóstico Veterinario de la Universidad Estatal de Michigan para un examen post mortem. Los hallazgos comunes del examen macroscópico incluyeron óvulos flácidos, encogidos o atrofiados (todas las gallinas), pododermatitis, aerosaculitis, hepatomegalia, esplenomegalia, ascitis y palidez del ventrículo izquierdo. El examen histopatológico del cerebro, el cerebelo y el tronco encefálico reveló infiltrado perivascular linfocítico leve, vasculitis y gliosis, lo que sugiere una encefalitis viral. En el corazón, había necrosis de cardiomiocitos multifocal leve, mineralización e infiltración por linfocitos y macrófagos. Se realizó PCR para el virus de la enfermedad de Newcastle, el virus de la influenza aviar, el virus de la encefalitis equina del este y para el virus del Nilo Occidental (WNV). Las muestras de cerebro y corazón dieron positivo para el virus del Nilo Occidental mediante PCR, y se detectó antígeno del virus del Nilo Occidental en el cerebelo mediante inmunohistoquímica. Este es el primer reporte que asocia la infección por el virus del Nilo Occidental con una caída en la producción de huevos en aves acuáticas, que se sabe que son importantes especies reservorio del virus del Nilo Occidental y, como tales, generalmente son asintomáticos.

The granulosa cell response to luteinizing hormone is partly mediated by YAP1-dependent induction of amphiregulin.

BACKGROUND: The LH surge is a pivotal event that triggers multiple key ovarian processes including oocyte maturation, cumulus expansion, follicular wall rupture and luteinization of mural granulosa and theca cells. Recently, LH-dependent activation of the Hippo signaling pathway has been shown to be required for the differentiation of granulosa cells into luteal cells. Still, the precise interactions between Hippo and LH signaling in murine granulosa cells remain to be elucidated. METHODS: To detect the expression of effectors of the Hippo pathway, western blot, immunohistochemical and RT-qPCR analyses were performed on granulosa cells treated with LH in vitro or isolated from immature mice treated with eCG and hCG. Cultured granulosa cells were pretreated with pharmacologic inhibitors to identify the signaling pathways involved in Hippo regulation by LH. To study the roles of Yap1 and Taz in the regulation of the LH signaling cascade, RT-qPCR and microarray analyses were done on granulosa cells from Yap1f/f;Tazf/f mice treated with an adenovirus to drive cre expression. RT-qPCR was performed to evaluate YAP1 binding to the Areg promoter following chromatin immunoprecipitation of granulosa cells collected from mice prior to or 60 min following hCG treatment. RESULTS: Granulosa cells showed a transient increase in LATS1, YAP1 and TAZ phosphorylation levels in response to the ovulatory signal. This Hippo activation by LH was mediated by protein kinase A. Furthermore, Yap1 and Taz are required for the induction of several LH target genes such as Areg, Pgr and Ptgs2, and for the activation of the ERK1/2 pathway. Consistent with these results, there was a substantial overlap between genes that are upregulated by LH and those that are downregulated following loss of Yap1/Taz, highlighting a major role for Hippo in mediating LH actions in the ovulation process. Finally, we showed that there is a marked recruitment of YAP1 to the Areg promoter of granulosa cells in response to hCG stimulation. CONCLUSIONS: Overall, these results indicate that Hippo collaborates with the cAMP/PKA and ERK1/2 pathways to participate in the precise regulation of the LH cascade, and that Areg, as a direct transcriptional target of YAP1, is involved in mediating its actions in the ovary. Video Abstract.

Quantitative Expression of TYR, CD34, and CALD1 Discriminates Between Canine Oral Malignant Melanomas and Soft Tissue Sarcomas.

Canine oral malignant melanomas (OMMs) exhibit a variety of morphologic phenotypes, including a spindloid variant. The microscopic diagnosis of spindloid OMMs is based on junctional activity and/or the presence of melanin pigment. In the absence of these features, spindloid OMMs are difficult to differentiate from soft tissue sarcomas (STS). An antibody cocktail (MDX) that includes Melan-A, PNL2, and tyrosinase-related proteins 1 and 2 (TRP-1 and TRP-2) is the current gold standard for identifying amelanotic OMMs by immunohistochemistry (IHC). However, MDX is less sensitive for diagnosing spindloid amelanotic OMMs. This raises concern for biopsy specimens that lack overlying epithelium, making it potentially difficult to differentiate OMM from STS by IHC. The goal of this study was to identify additional markers to help differentiate between STS and OMMs that lack pigment and junctional activity. SOX-10 has recently been proposed as a sensitive marker for melanocytes in humans but has not been validated in dogs. Similarly, RNA expression for various genes has been analyzed in humans, but not in the context of diagnosing canine melanocytic neoplasms. For this retrospective study, formalin-fixed, paraffin-embedded tissues from 20 OMMs, 20 STS, and 20 oral spindle cell tumors (OSCTs) that lacked junctional activity and pigmentation were selected. IHC for MDX, SOX-10, and laminin, in parallel with RT-qPCR of TYR, SOX10, CALD1, CD34, DES, and LAMA1, was performed in all cases. TYR, CD34, and CALD1 were the most discriminatory genes in differentiating between OMM and STS, all having 100% specificity and 65, 95, and 60% sensitivity, respectively. While all 20 OMMs were immunohistochemically labeled for SOX-10, two STS were also labeled (100% sensitivity and 90% specificity). MDX IHC labeled all 20 OMMs and no STS. Surprisingly, none of the 20 OSCTs expressed TYR RNA above the cutoff, and 14/20 OSCTs expressed CALD1 or CD34 RNA above the cutoff, thereby confirming them as STS. Four OSCT were suspect STS, and no OSCTs were confirmed as OMMs based on IHC and RNA expression patterns. In conclusion, the RNA levels of TYR, CD34, and CALD1 should be evaluated in suspected amelanotic OMMs that are negative for MDX to accurately differentiate between OMM and STS.

Scedosporium apiospermum infection presenting as a mural urinary bladder mass and focal peritonitis in a Border Collie.

Scedosporium apiospermum is an opportunistic mold that is an emerging disease in humans and animals. This report describes a case of S. apiospermum infection inciting a mural urinary bladder mass and focal peritonitis in a dog that had a history of multiple traumatic events several years prior. For diagnosis, culture followed by MALDI-ToF, PCR, and sequencing was performed to accurately identify the species. Susceptibility testing was also performed due to the inherent resistance of S. apiospermum to numerous antifungal agents.