Biology subjects

Conroy, L. R.

Publications and source records attributed to Conroy, L. R..

4 recordsLinked to original sources

bioRxiv2023

GalNAc-siRNA Mediated Knockdown of Ketohexokinase Versus Systemic, Small Molecule Inhibition of its Kinase Activity Exert Divergent Effects on Hepatic Metabolism in Mice on a HFD

Consumption of diets high in sugar and fat are well-established risk factors for the development of obesity and its metabolic complications, including non-alcoholic fatty liver disease. Metabolic dysfunction associated with sugar intake is dependent on fructose metabolism via ketohexokinase (KHK). Here, we compared the effects of systemic, small molecule inhibition of KHK enzymatic activity to hepatocyte-specific, GalNAc-siRNA mediated knockdown of KHK in mice on a HFD. Both modalities led to an improvement in liver steatosis, however, via substantially different mechanisms. KHK knockdown profoundly decreased lipogenesis, while the inhibitor increased the fatty acid oxidation pathway. Moreover, hepatocyte-specific KHK knockdown completely prevented hepatic fructose metabolism and improved glucose tolerance. Conversely, KHK inhibitor only partially reduced fructose metabolism, but it also decreased downstream triokinase. This led to the accumulation of fructose-1 phosphate, resulting in glycogen accumulation, hepatomegaly, and impaired glucose tolerance. In summary, KHK profoundly impacts hepatic metabolism, likely via both kinase-dependent and independent mechanisms. HIGHLIGHTSO_LIKHK knockdown or inhibition of its kinase activity differently target hepatic metabolism. C_LIO_LIKHK inhibitor increases F1P and glycogen accumulation as it also lowers triokinase. C_LIO_LIKHK knockdown completely prevents hepatic fructose metabolism and lipogenesis. C_LIO_LIE of wild type, but not mutant, kinase dead KHK-C increases glycogen accumulation. C_LI

molecular biology↗

bioRxiv2022

In Situ Microwave Fixation to Define the Terminal Rodent Brain Metabolome

The brain metabolome directly connects to brain physiology and neuronal function. Brain glucose metabolism is highly heterogeneous among brain regions and continues postmortem. Therefore, challenges remain to capture an accurate snapshot of the physiological brain metabolome in healthy and diseased rodent models. To overcome this barrier, we employ a high-power focused microwave for the simultaneous euthanasia and fixation of mouse brain tissue to preserve metabolite pools prior to surgical removal and dissection of brain regions. We demonstrate exhaustion of glycogen and glucose and increase in lactate production during conventional rapid brain resection prior to preservation by liquid nitrogen that is not observed with microwave fixation. Next, microwave fixation was employed to define the impact of brain glucose metabolism in the mouse model of streptozotocin-induced type 1 diabetes. Using both total pool and isotope tracing analyses, we identified global glucose hypometabolism in multiple regions of the mouse brain, evidenced by reduced 13C enrichment into glycogen, glycolysis, and the TCA cycle. Reduced glucose metabolism correlated with a marked decrease in GLUT2 expression and several metabolic enzymes in unique brain regions. In conclusion, our study supports the incorporation of microwave fixation to study terminal brain metabolism in rodent models.

biochemistry↗

bioRxiv2021

Multi-Dimensional Reduction Clustering of Complex Carbohydrates Reveal Tissue Metabolism, Heterogeneity and Histopathology

Formalin-fixed paraffin-embedded (FFPE) human tissues represent the world's largest collection of accessible clinical specimens with matched, well-annotated clinical course for disease progression. Currently, FFPE sections are limited to low throughput histo- and immunological assessments. Extracting largescale molecular information remains a major technological barrier to uncover the vast potential within FFPE specimens for translation and clinical research. Two critical but understudied facets of glucose metabolism are anabolic pathways for glycogen and N-linked glycan biosynthesis. Together, these complex carbohydrates represent bioenergetics, protein-structure function, and tissue architecture in human biology. Herein, we report the high-dimensional Metabolomics-Assisted Digital pathology Imaging (Madi) workflow that combines matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI) with machine learning for the comprehensive assessment of tissue heterogeneity, histopathology, and metabolism in human FFPE sections. In normal human tissue sections, Madi accurately identifies anatomical regions within liver and the brain. In human lung diseases, Madi accurately predicts major lung pathologies such as honeycomb change, late-stage fibrosis, diffuse alveolar damage (DAD), and acute fibrinous and organizing pneumonia (AFOP) from idiopathic pulmonary fibrosis (IPF) and COVID-19 pneumonia specimens with precision. In depth pathway enrichment analyses reveal unique metabolic pathways are associated with distinct pathological regions, which highlight aberrant complex carbohydrate metabolism as a previously unknown molecular event associated with disease progression that could hold key to future therapeutic interventions.

systems biology↗

bioRxiv2020

Mass Spectrometry Imaging of N-Glycans Reveals Racial Discrepancies in Low Grade Prostate Tumors

Prostate cancer is the most common cancer in men worldwide. Despite its prevalence, there is a critical knowledge gap regarding the underlining molecular events that result in higher incidence and mortality rate in Black men. Identifying molecular features that separate racial disparities is a critical step in prostate cancer research that could lead to predictive biomarkers and personalized therapy. N-linked glycosylation is a co-translational event during protein folding that modulates a myriad of cellular processes. Recently, aberrant N-linked glycosylation has been reported in prostate cancers. However, the full clinical implications of dysregulated glycosylation in prostate cancer has yet to be explored. Herein, we performed high-throughput matrix-assisted laser desorption ionization mass spectrometry analysis to characterize the N-glycan profile from tissue microarrays of over 100 patient tumors with over 10 years of follow up data. We identified several species of N-glycans that were profoundly different between low grade prostate tumors resected from White and Black patients. Further, these glycans predict opposing overall survival between White and Black patients with prostate cancer. These data suggest differential N-linked glycosylation underline the racial disparity of prostate cancer prognosis. Our study highlights the potential applications of MALDI-MSI for digital pathology and biomarker to study racial disparity of prostate cancer patients. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=79 SRC="FIGDIR/small/260026v1_ufig1.gif" ALT="Figure 1"> View larger version (25K): org.highwire.dtl.DTLVardef@15f9b35org.highwire.dtl.DTLVardef@1c6d200org.highwire.dtl.DTLVardef@5188eorg.highwire.dtl.DTLVardef@8f347e_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗