A Revamped Rat Reference Genome Improves the Discovery of Genetic Diversity in Laboratory Rats
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Rattus norvegicus has been used in many fields of study related to human disease; its genome was sequenced shortly after the genomes of Homo sapiens and Mus musculus. Investigators report extensive analyses of the improvements in mRatBN7.2, compared with the previous version. They conducted a broad analysis of a whole-genome sequencing data set of 163 samples from 120 inbred rat strains and substrains. Several additional resources have been created.
Cdk8/CDK19 Promotes Mitochondrial Fission Through Drp1 Phosphorylation and Can Phenotypically Suppress Pink1 Deficiency in Drosophila
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Pink1 is a mitochondrial kinase implicated in Parkinson’s disease and is conserved among humans, rodents, and flies. In this study, researchers found that Cdk8 in Drosophila (i.e., the orthologue of vertebrate CDK8 and CDK19) promotes the phosphorylation of Drp1 (i.e., a protein required for mitochondrial fission) at the same residue as Pink1. Cdk8 is expressed in both the cytoplasm and nucleus, and neuronal loss of Cdk8 reduces fly life span and causes bang sensitivity and elongated mitochondria in both muscles and neurons.
Identifying Potential Dietary Treatments for Inherited Metabolic Disorders Using Drosophila Nutrigenomics
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Inherited metabolic disorders are known to cause severe neurological impairment and child mortality and can sometimes respond to dietary treatment; however, a suitable paradigm for testing diets is lacking for developing effective dietary treatment. In this study, researchers found that 26 of 35 Drosophila amino acid disorder models screened for disease–diet interactions displayed diet-altered development and/or survival.
SHIV-C109p5 NHP Induces Rapid Disease Progression in Elderly Macaques with Extensive GI Viral Replication
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Researchers are interested in developing animal models infected with simian–human immunodeficiency virus (SHIV) to better understand prevention of HIV acquisition. Researchers generated pathogenic SHIV clade C transmitted/founder stock by in vivo passage using geriatric rhesus macaques of both sexes. They reported that the infection resulted in high sustained viral loads and induced rapid pathology and wasting, necessitating euthanasia between 3 and 12 weeks post-infection. The extensive viral replication in gut and lymphoid tissues indicated a fit viral stock.
Induction of Durable Remission by Dual Immunotherapy in SHIV-Infected ART-Suppressed Macaques
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The latent viral reservoir is established within the first few days of HIV infection and remains a barrier to a clinical cure. Researchers characterized the effects of a combined Anktiva (N-803) treatment with broadly neutralizing antibodies (bNAbs) using male and female rhesus macaques infected with simian–human immunodeficiency virus infection. Their data suggest that these agents synergize to enhance CD8+ T-cell function, particularly when multiple bNAbs are used.
Cholera Toxin B Scaffolded, Focused SIV V2 Epitope Elicits Antibodies That Influence the Risk of SIVmac251 Acquisition in Macaques
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Previous work has indicated that the production of antibodies against epitopes in the V2 loop of gp120—a protein component of the viral spikes used to infiltrate host cells—correlates with protection from viral acquisition. Researchers assessed the efficacy of a simian immunodeficiency virus (SIV) vaccine consisting of a V2c epitope scaffolded onto cholera toxin B in rhesus macaques of both sexes.
TGF-β Blockade Drives a Transitional Effector Phenotype in T Cells Reversing SIV Latency and Decreasing SIV Reservoirs In Vivo
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Interruption of antiretroviral therapy leads to rapid rebound of viremia due to the establishment of a persistent viral reservoir early after infection. Using a treatment regimen similar to the one tested in clinical trials, the authors show how galunisertib affects immune cell function, increases simian immunodeficiency virus (SIV) reactivation, and reduces the viral reservoir in female rhesus macaques. Their findings reveal a galunisertib-driven shift toward an effector phenotype in T and natural killer cells.
Epigenetic MLH1 Silencing Concurs With Mismatch Repair Deficiency in Sporadic, Naturally Occurring Colorectal Cancer in Rhesus Macaques
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Rhesus macaques serve as a useful model for colorectal cancer (CRC) in humans, but more data are needed to understand the molecular pathogenesis of these cancers. Using male and female rhesus macaques, researchers investigated mismatch repair status, microsatellite instability, genetic mutations, transcriptional differences, and epigenetic alterations associated with CRC.
CDK4/6 Inhibition Sensitizes Intracranial Tumors to PD-1 Blockade in Preclinical Models of Brain Metastasis
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Brain metastases are associated with high morbidity and are often resistant to immune checkpoint inhibitors. In this study, investigators evaluated the efficacy of combining CDKi (abemaciclib) and anti–PD-1 therapy (“combination therapy”) in mouse models for brain metastases, elucidated how combination therapy remodeled the tumor–immune microenvironment (TIME) and T-cell receptor (TCR) repertoires, and investigated the effects of CDKi on T-cell development and maintenance in NOD-scid Il2rgnull (NSG) mice engrafted with human immune systems (“humanized mice”).
Validity of Xiphophorus Fish as Models for Human Disease
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Xiphophorus is the one of the oldest animal systems for studying melanoma. In this article, the authors summarize current Xiphophorus models for other human diseases. They review how Xiphophorus fishes and their interspecies hybrids can be used for studying human diseases and highlight research opportunities enabled by these unique models (both established and emerging). They identified several emerging Xiphophorus models, including for albinism, micromelanophore pigmentation, fin regeneration, and diet-induced obesity.