Biology subjects

Shah, A. P.

Publications and source records attributed to Shah, A. P..

4 recordsLinked to original sources

bioRxiv2021

HepT1-derived murine models of high-risk hepatoblastoma display vascular invasion, metastasis, and circulating tumor cells

Hepatoblastoma (HB) is the most common pediatric primary liver malignancy, and survival for high-risk disease approaches 50%. Mouse models of HB fail to recapitulate hallmarks of high-risk disease. The aim of this work was to generate murine models that show high-risk features including multifocal tumors, vascular invasion, metastasis, and circulating tumor cells (CTCs). HepT1 cells were injected into the livers or tail veins of mice, and tumor growth was monitored with magnetic resonance and bioluminescent imaging. Blood was analyzed with fluorescence activated cell sorting to identify CTCs. Intra- and extra-hepatic tumor samples were harvested for immunohistochemistry and RNA and DNA sequencing. Cell lines were grown from tumor samples and profiled with RNA sequencing. With intrahepatic injection of HepT1 cells, 100% of animals grew liver tumors and showed vascular invasion, metastasis, and CTCs. Mutation profiling revealed genetic alterations in seven cancer-related genes, while transcriptomic analyses showed changes in gene expression with cells that invade vessels. Tail vein injection of HepT1 cells resulted in multifocal, metastatic disease. These unique models will facilitate further meaningful studies of high-risk HB. Summary StatementIn this work, we developed and thoroughly characterized several unique models of hepatoblastoma derived from the HepT1 cell line that show high-risk features.

cancer biology↗

bioRxiv2020

Constitutive deletion of translin (Tsn) enhances locomotor response to amphetamine: role of developmental effects

The translin/trax microRNA-degrading enzyme mediates activity-induced changes in translation that underlie several long-lasting forms of cellular plasticity. As translin and trax are expressed in dopaminergic and striatal neurons, we proceeded to investigate whether deletion of Tsn blocks amphetamine sensitization, a long-lasting, translation-dependent form of behavioral plasticity, Although we expected constitutive Tsn deletion to impair amphetamine sensitization, we found, instead, that it enhances the hyperlocomotion produced by the initial dose of amphetamine. Since these mice display elevated adiposity, which alters pharmacokinetics of many drugs, we measured brain amphetamine levels in Tsn knockout mice and found that these are elevated. We also found that diet-induced increases in adiposity in WT mice correlate with elevated brain amphetamine levels. As amphetamine and its analogues are widely used to treat attention deficit disorder, which is associated with obesity, further studies are needed to assess the impact of adiposity on amphetamine levels in these patients.

neuroscience↗

bioRxiv2020

Genetic inactivation of the translin/trax microRNA-degrading enzyme phenocopies the robust adiposity induced by Translin (Tsn) deletion

ObjectiveDeletion of Translin (Tsn) from mice induces an unusual metabolic profile characterized by robust adiposity, normal body weight and glucose tolerance. Translin (TN) protein and its partner, trax (TX), form the TN/TX microRNA-degrading enzyme. Since the microRNA system plays a prominent role in regulating metabolism, we reasoned that the metabolic profile displayed by Tsn KO mice might reflect dysregulation of microRNA signaling. MethodsTo test this hypothesis, we inserted a mutation, E126A, in Tsnax, the gene encoding TX, that abolishes the microRNA-degrading enzymatic activity of the TN/TX complex. In addition, to help define the cell types that drive the adiposity phenotype, we have also generated mice with floxed alleles of Tsn or Tsnax. ResultsIntroduction of the E126A mutation in Tsnax does not impair expression of TN or TX proteins or their co-precipitation. Furthermore, these mice display selective increases in microRNAs that match those induced by Tsn deletion, confirming that this mutation in Tsnax inactivates the microRNA-degrading activity of the TN/TX complex. Mice homozygous for the Tsnax (E126A) mutation display a metabolic profile that closely mimics that of Tsn KO mice. Selective deletion of Tsn or Tsnax from either adipocytes or hepatocytes, two candidate cell types, does not phenocopy the elevated adiposity displayed by mice with constitutive Tsn deletion or the Tsnax(E126A) mutation. Furthermore, global, conditional deletion of Tsn in adulthood does not elicit increased adiposity. ConclusionTaken together, these findings indicate that inactivation of the TN/TX microRNA-degrading enzyme during development is necessary to drive the robust adiposity displayed by Tsn KO mice.

cell biology↗

bioRxiv2018

Monocyte and Macrophage Subtypes as Paired Cell Biomarkers for Coronary Artery Disease

Background: Monocytes and macrophages are central to atherosclerosis, but how they mark progression of human coronary artery disease (CAD) is unclear. We tested whether patients monocyte subtypes paired with their derived macrophage profiles correlate with extent of CAD.\n\nMethods: Peripheral blood was collected from 30 patients undergoing cardiac catheterization, and patients were categorized as having no significant CAD, single vessel disease, or multivessel disease according to the number of affected coronary arteries. Mononuclear cells were measured for monocyte markers CD14 and CD16 by flow cytometry, and separate monocytes were cultured into macrophages over 7 days and measured for polarization markers CD86 and CD206.\n\nResults: At baseline, patients with greater CAD burden were older with higher rates of statin use, whereas all other characteristics were similar across the spectrum of coronary disease. Non-classical (CD14loCD16hi) and all CD16+ monocytes were elevated in patients with single vessel and multivessel disease compared to those without significant CAD (8.6% and 10.5% vs. 2.8%, p < 0.05), whereas regulatory M2 macrophages (CD206+) were decreased in patients with single vessel and multivessel disease (0.34% and 0.34% vs. 1.4%, p < 0.05). An inverse relationship between paired CD16+ monocytes and M2 macrophages marked CAD severity. CAD was also found to be more tightly associated with CD16+ cells than age or traditional cardiovascular risk factors on multiple regression analysis of these patients.\n\nConclusions: CAD extent is correlated directly with CD16+ monocytes and inversely with M2 (CD206+) macrophages, suggesting circulating monocytes may influence downstream polarization of lesional macrophages. These measures of monocyte and macrophage subtypes hold potential as biomarkers in CAD.

physiology↗