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Stork BA, Dean A, York B. Methodology for measuring oxidative capacity of isolated peroxisomes in the Seahorse assay. J Biol Methods 2022; 9:e160. [PMID: 35733440 PMCID: PMC9208851 DOI: 10.14440/jbm.2022.374] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 02/01/2022] [Accepted: 02/01/2022] [Indexed: 12/30/2022] Open
Abstract
The regulation of cellular energetics is a complex process that requires the coordinated function of multiple organelles. Historically, studies focused on understanding cellular energy utilization and production have been overwhelmingly concentrated on the mitochondria. While mitochondria account for the majority of intracellular energy production, they alone are incapable of maintaining the variable energetic demands of the cell. The peroxisome has recently emerged as a secondary metabolic organelle that complements and improves mitochondrial performance. Although mitochondria and peroxisomes are structurally distinct organelles, they share key functional similarities that allows for the potential to repurpose readily available tools initially developed for mitochondrial assessment to interrogate peroxisomal metabolic function in a novel manner. To this end, we report here on procedures for the isolation, purification and real-time metabolic assessment of peroxisomal β-oxidation using the Agilent Seahorse® system. When used together, these protocols provide a straightforward, reproducible and highly quantifiable method for measuring the contributions of peroxisomes to cellular and organismal metabolism.
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Affiliation(s)
- Brittany A Stork
- Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Adam Dean
- Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Brian York
- Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA.,Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX 77030, USA
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Gilad Y, Eliaz Y, Yu Y, Dean AM, Han SJ, Qin L, O’Malley BW, Lonard DM. A genome-scale CRISPR Cas9 dropout screen identifies synthetically lethal targets in SRC-3 inhibited cancer cells. Commun Biol 2021; 4:399. [PMID: 33767353 PMCID: PMC7994904 DOI: 10.1038/s42003-021-01929-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 02/24/2021] [Indexed: 02/01/2023] Open
Abstract
Steroid receptor coactivator 3 (SRC-3/NCoA3/AIB1), is a key regulator of gene transcription and it plays a central role in breast cancer (BC) tumorigenesis, making it a potential therapeutic target. Beyond its function as an important regulator of estrogen receptor transcriptional activity, SRC-3 also functions as a coactivator for a wide range of other transcription factors, suggesting SRC-3 inhibition can be beneficial in hormone-independent cancers as well. The recent discovery of a potent SRC-3 small molecule inhibitor, SI-2, enabled the further development of additional related compounds. SI-12 is an improved version of SI-2 that like SI-2 has anti-proliferative activity in various cancer types, including BC. Here, we sought to identify gene targets, that when inhibited in the presence of SI-12, would lead to enhanced BC cell cytotoxicity. We performed a genome-scale CRISPR-Cas9 screen in MCF-7 BC cells under conditions of pharmacological pressure with SI-12. A parallel screen was performed with an ER inhibitor, fulvestrant, to shed light on both common and distinct activities between SRC-3 and ERα inhibition. Bearing in mind the key role of SRC-3 in tumorigenesis of other types of cancer, we extended our study by validating potential hits identified from the MCF-7 screen in other cancer cell lines.
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Affiliation(s)
- Yosi Gilad
- grid.39382.330000 0001 2160 926XDepartment of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX USA
| | - Yossi Eliaz
- grid.39382.330000 0001 2160 926XDepartment of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX USA
| | - Yang Yu
- grid.39382.330000 0001 2160 926XDepartment of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX USA
| | - Adam M. Dean
- grid.39382.330000 0001 2160 926XDepartment of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX USA
| | - San Jung Han
- grid.39382.330000 0001 2160 926XDepartment of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX USA
| | - Li Qin
- grid.39382.330000 0001 2160 926XDepartment of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX USA
| | - Bert W. O’Malley
- grid.39382.330000 0001 2160 926XDepartment of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX USA
| | - David M. Lonard
- grid.39382.330000 0001 2160 926XDepartment of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX USA
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Dong B, Zhou Y, Wang W, Scott J, Kim K, Sun Z, Guo Q, Lu Y, Gonzales NM, Wu H, Hartig SM, York RB, Yang F, Moore DD. Vitamin D Receptor Activation in Liver Macrophages Ameliorates Hepatic Inflammation, Steatosis, and Insulin Resistance in Mice. Hepatology 2020; 71:1559-1574. [PMID: 31506976 DOI: 10.1002/hep.30937] [Citation(s) in RCA: 89] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 08/09/2019] [Indexed: 12/12/2022]
Abstract
BACKGROUND AND AIMS Obesity-induced chronic inflammation is a key component in the pathogenesis of nonalcoholic fatty liver disease (NAFLD) and insulin resistance. Increased secretion of proinflammatory cytokines by macrophages in metabolic tissues promotes disease progression. In the diet-induced obesity (DIO) mouse model, activation of liver resident macrophages, or Kupffer cells (KCs), drives inflammatory responses, which recruits circulating macrophages and promotes fatty liver development, and ultimately contributes to impaired hepatic insulin sensitivity. Hepatic macrophages express the highest level of vitamin D receptors (VDRs) among nonparenchymal cells, whereas VDR expression is very low in hepatocytes. VDR activation exerts anti-inflammatory effects in immune cells. APPROACH AND RESULTS Here we found that VDR activation exhibits strong anti-inflammatory effects in mouse hepatic macrophages, including those isolated from DIO livers, and mice with genetic loss of Vdr developed spontaneous hepatic inflammation at 6 months of age. Under the chronic inflammation conditions of the DIO model, VDR activation by the vitamin D analog calcipotriol reduced liver inflammation and hepatic steatosis, significantly improving insulin sensitivity. The hyperinsulinemic euglycemic clamp revealed that VDR activation greatly increased the glucose infusion rate, while hepatic glucose production was remarkably decreased. Glucose uptake in muscle and adipose did not show similar effects, suggesting that improved hepatic insulin sensitivity is the primary contributor to the beneficial effects of VDR activation. Finally, specifically ablating liver macrophages by treatment with clodronate liposomes largely abolished the beneficial metabolic effects of calcipotriol, confirming that VDR activation in liver macrophages is required for the antidiabetic effect. CONCLUSIONS Activation of liver macrophage VDRs by vitamin D ligands ameliorates liver inflammation, steatosis and insulin resistance. Our results suggest therapeutic paradigms for treatment of NAFLD and type 2 diabetes mellitus.
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Affiliation(s)
- Bingning Dong
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX
| | - Ying Zhou
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX.,Integrative Molecular and Biomedical Sciences Graduate Program, Baylor College of Medicine, Houston, TX
| | - Wei Wang
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX
| | - Jessica Scott
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX.,Integrative Molecular and Biomedical Sciences Graduate Program, Baylor College of Medicine, Houston, TX
| | - KangHo Kim
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX
| | - Zhen Sun
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX
| | - Qi Guo
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX
| | - Yang Lu
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX
| | - Naomi M Gonzales
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX
| | - Huaizhu Wu
- Department of Medicine, Baylor College of Medicine, Houston, TX
| | - Sean M Hartig
- Department of Medicine, Baylor College of Medicine, Houston, TX
| | - Robert Brian York
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX
| | - Feng Yang
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX
| | - David D Moore
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX
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Marcelo KL, Means AR, York B. The Ca(2+)/Calmodulin/CaMKK2 Axis: Nature's Metabolic CaMshaft. Trends Endocrinol Metab 2016; 27:706-718. [PMID: 27449752 PMCID: PMC5035586 DOI: 10.1016/j.tem.2016.06.001] [Citation(s) in RCA: 140] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 06/03/2016] [Accepted: 06/06/2016] [Indexed: 12/26/2022]
Abstract
Calcium (Ca(2+)) is an essential ligand that binds its primary intracellular receptor calmodulin (CaM) to trigger a variety of downstream processes and pathways. Central to the actions of Ca(2+)/CaM is the activation of a highly conserved Ca(2+)/CaM kinase (CaMK) cascade that amplifies Ca(2+) signals through a series of subsequent phosphorylation events. Proper regulation of Ca(2+) flux is necessary for whole-body metabolism and disruption of Ca(2+) homeostasis has been linked to various metabolic diseases. Here we provide a synthesis of recent advances that highlight the roles of the Ca(2+)/CaMK axis in key metabolic tissues. An appreciation of this information is critical to understanding the mechanisms by which Ca(2+)/CaM-dependent signaling contributes to metabolic homeostasis and disease.
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Affiliation(s)
- Kathrina L Marcelo
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Anthony R Means
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA; Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX, USA.
| | - Brian York
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA; Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX, USA.
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