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Peralta, S.

Publications and source records attributed to Peralta, S..

5 recordsLinked to original sources

Metagenomic and transcriptomic signatures of periodontitis in companion dogs

BackgroundPeriodontitis (Perio) is a progressive oral disease characterized by inflammation and degradation of the periodontal apparatus and is associated with local and systemic morbidity including loss of teeth, cardiovascular disease, and diabetes mellitus, among others. Perio is highly prevalent in domestic canines and exhibits certain parallels in pathogenesis and pathophysiology to Perio in humans, although standard treatments are less effective. In both species, a complex interplay between oral microbiota and host immune response is implicated in the etiology of Perio but is not fully understood. ResultsUsing shotgun metagenomics and RNA-seq on oral samples from companion dogs, we identify features of the oral microbiome and host transcriptional profile that are associated with Perio and its progression. We observe differences in microbiota composition between Perio and non-Perio animals that are largely consistent with what has been described in humans but also identify several species that are distinctly associated with canine Perio. We observe an abrupt shift in host gene expression related to immune response and tissue structure that is associated with disease severity, specifically the progression from mild periodontal disease (PD) to more severe Perio and the initiation of clinical attachment loss. The gingival plaque microbiota exhibits a parallel dynamic, with distinct compositional profiles in mild, moderate, and severe PD. We then examine several of the known mechanistic components of the keystone pathogen hypothesis of PD, identifying specific commonalities between canine and human pathologies, including the involvement of Porphyromonas species and related virulence factors. Additionally, we show infiltration of gingival tissue by Porphyromonas and Tannerella spp. via fluorescence microscopy. Finally, we assess correlations between host gene expression and microbial metabolic pathways which suggest additional potential virulence factors. ConclusionsThis work elucidates the metagenomic and transcriptomic signatures of Perio in companion dogs with the goals of informing veterinary medicine, evaluating the potential of canines as a model organism for the study of Perio, and clarifying the relationship between Perio development and progression, the oral microbiota, and the localized host response. Our findings provide insight into the etiopathogenesis of canine Perio and its relationship to human Perio and suggest novel targets of potential translational interest.

microbiology↗

Neuroepithelial reprogramming and ERBB vulnerability in canine acanthomatous ameloblastoma

Canine acanthomatous ameloblastoma (CAA) is a locally invasive benign oral neoplasm that is difficult to distinguish from canine oral squamous cell carcinoma (COSCC) due to overlapping clinical, radiologic, and histologic features. Although both tumors exhibit MAPK pathway activation, their mutational landscapes are distinct. Furthermore, previous studies using bulk RNA sequencing (RNA-seq) have demonstrated pronounced differences in programs related to, among others, hypoxia, PI3K-AKT signaling, and cell proliferation. However, these bulk studies lacked the resolution to elucidate the cellular heterogeneity of CAA relative to COSCC. We therefore performed single-nucleus RNA-seq to define the cellular gene expression landscape of CAA, COSCC, and healthy gingiva. Across [~]205,000 nuclei, we identified major epithelial, immune, endothelial, and mesenchymal populations, as well as two epithelial subtypes uniquely enriched in CAA. The CAA-specific keratinocytes exhibited a neuronal-like expression program defined by synaptic regulators, KRAS-associated signaling pathways, and markedly elevated expression of PEG3, ERBB4, GABRB1, MAGI2, and CASK. These findings were validated by bulk RNA-seq, qPCR, and immunohistochemistry, which demonstrated strong nuclear localization of PEG3 exclusively in CAA epithelium. A kinase inhibitor screen independently identified ERBB4 as a candidate therapeutic vulnerability, and pharmacologic inhibition with neratinib was effective. Together, these findings reveal a previously unrecognized neuroepithelial cell state that defines CAA, distinguishes it from COSCC, and reveals unique diagnostic and therapeutic signaling dependencies. Given the molecular and histopathologic parallels between CAA and human ameloblastoma, these data further position CAA as a naturally occurring comparative model for studying ameloblastoma biology and therapeutic vulnerabilities. Significance StatementCanine acanthomatous ameloblastoma (CAA) is a common locally aggressive oral neoplasm often misdiagnosed as canine oral squamous cell carcinoma (COSCC) due to overlapping clinical, radiologic, and histologic features. Using single-nucleus RNA sequencing of CAA, COSCC, and healthy gingiva, we resolve the microenvironment of these tumors and detect two epithelial subpopulations unique to CAA. These CAA-specific keratinocytes exhibit a neuroepithelial-like signature characterized by synaptic regulators, KRAS-associated signaling, and elevated PEG3 and ERBB4 expression. Functional kinase inhibitor screening of patient derived microtumor slices independently converged on ERBB4 as an effective therapeutic target. Together, our study provides a molecular framework for distinguishing CAA from COSCC and establishes a comparative oncology model with translational relevance to human ameloblastoma and other ERBB-driven epithelial neoplasms.

cancer biology↗

Epithelial-Mesenchymal Plasticity is Associated with Immunosuppressive Features in Canine Mammary Carcinomas

Epithelial-mesenchymal plasticity (EMP) is a cellular process activated in carcinoma cells to drive invasiveness, metastasis, and chemoresistance. Recently, we have demonstrated that activation of the EMP program also results in the assembly of an immunosuppressive tumor microenvironment and resistance to immunotherapy in an immunocompetent orthotopic murine model. However, it has yet to be shown whether these findings can be translated to canine carcinomas. Here, we show that in spontaneous canine mammary carcinomas (CMCs), which share similar histopathologic, molecular, and clinical features with human breast cancers, EMP activation is linked to the recruitment of immunosuppressive cells including regulatory T-cells and M2-like macrophages. Additionally, through transcriptomic profiling of CMCs, we identify that the glycoprotein CD109 is associated with EMP-mediated immunosuppression across canine, murine, and human breast cancer models. CD109 has been previously associated with tumorigenicity, but not immunosuppression in cancers of any species. Finally, we identified upregulation of several immunosuppressive paracrine factors across multiple canine carcinomas, including oral squamous cell carcinoma, urothelial carcinoma, and pulmonary carcinoma samples. These findings demonstrate for the first time that the EMP program is associated with immunosuppression in canine carcinomas, with direct translational implications for human breast cancers.

cancer biology↗

β-hydroxybutyrate is a metabolic regulator of proteostasis in the aged and Alzheimer disease brain

Loss of proteostasis is a hallmark of aging and Alzheimer disease (AD). Here, we identify {beta}-hydroxybutyrate ({beta}HB), a ketone body, as a regulator of protein solubility in the aging brain. {beta}HB is a small molecule metabolite which primarily provides an oxidative substrate for ATP during hypoglycemic conditions, and also regulates other cellular processes through covalent and noncovalent protein interactions. We demonstrate {beta}HB-induced protein insolubility across in vitro, ex vivo, and in vivo mouse systems. This activity is shared by select structurally similar metabolites, is not dependent on covalent protein modification, pH, or solute load, and is observable in mouse brain in vivo after delivery of a ketone ester. Furthermore, this phenotype is selective for pathological proteins such as amyloid-{beta}, and exogenous {beta}HB ameliorates pathology in nematode models of amyloid-{beta} aggregation toxicity. We have generated a comprehensive atlas of the {beta}HB-induced protein insolublome ex vivo and in vivo using mass spectrometry proteomics, and have identified common protein domains within {beta}HB target sequences. Finally, we show enrichment of neurodegeneration-related proteins among {beta}HB targets and the clearance of these targets from mouse brain, likely via {beta}HB-induced autophagy. Overall, these data indicate a new metabolically regulated mechanism of proteostasis relevant to aging and AD.

physiology↗

Complex feline disease mapping using a dense genotyping array

The current feline genotyping array of 63k single nucleotide polymorphisms has proven its utility within breeds, and its use has led to the identification of variants associated with Mendelian traits in purebred cats. However, compared to single gene disorders, association studies of complex diseases, especially with the inclusion of random bred cats with relatively low linkage disequilibrium, require a denser genotyping array and an increased sample size to provide statistically significant associations. Here, we undertook a multi-breed study of 1,122 cats, most of which were admitted and phenotyped for nine common complex feline diseases at the Cornell University Hospital for Animals. Using a proprietary 340k single nucleotide polymorphism mapping array, we identified significant genome-wide associations with hyperthyroidism, diabetes mellitus, and eosinophilic keratoconjunctivitis. These results provide genomic locations for variant discovery and candidate gene screening for these important complex feline diseases, which are relevant not only to feline health, but also to the development of disease models for comparative studies.

genetics↗