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Sheth AI, Engel K, Tolison H, Althoff MJ, Amaya ML, Krug A, Young T, Pei S, Patel SB, Minhajuddin M, Winters A, Miller R, Shelton I, St-Germain J, Ling T, Jones C, Raught B, Gillen A, Ransom M, Staggs S, Smith CA, Pollyea DA, Stevens BM, Jordan CT. Targeting Acute Myeloid Leukemia Stem Cells Through Perturbation of Mitochondrial Calcium. bioRxiv 2023:2023.10.02.560330. [PMID: 37873284 PMCID: PMC10592899 DOI: 10.1101/2023.10.02.560330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
We previously reported that acute myeloid leukemia stem cells (LSCs) are uniquely reliant on oxidative phosphorylation (OXPHOS) for survival. Moreover, maintenance of OXPHOS is dependent on BCL2, creating a therapeutic opportunity to target LSCs using the BCL2 inhibitor drug venetoclax. While venetoclax-based regimens have indeed shown promising clinical activity, the emergence of drug resistance is prevalent. Thus, in the present study, we investigated how mitochondrial properties may influence mechanisms that dictate venetoclax responsiveness. Our data show that utilization of mitochondrial calcium is fundamentally different between drug responsive and non-responsive LSCs. By comparison, venetoclax-resistant LSCs demonstrate a more active metabolic (i.e., OXPHOS) status with relatively high steady-state levels of calcium. Consequently, we tested genetic and pharmacological approaches to target the mitochondrial calcium uniporter, MCU. We demonstrate that inhibition of calcium uptake sharply reduces OXPHOS and leads to eradication of venetoclax-resistant LSCs. These findings demonstrate a central role for calcium signaling in the biology of LSCs and provide a therapeutic avenue for clinical management of venetoclax resistance.
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Affiliation(s)
- Anagha Inguva Sheth
- Division of Hematology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Krysta Engel
- Division of Hematology, University of Colorado School of Medicine, Aurora, CO, USA
- These authors contributed equally
| | - Hunter Tolison
- Division of Hematology, University of Colorado School of Medicine, Aurora, CO, USA
- These authors contributed equally
| | - Mark J Althoff
- Division of Hematology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Maria L. Amaya
- Division of Hematology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Anna Krug
- Division of Hematology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Tracy Young
- Division of Hematology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Shanshan Pei
- Liangzhu Laboratory, Zhejiang University Medical Center, Bone Marrow Transplantation Center, Hangzhou, China
| | - Sweta B. Patel
- Division of Hematology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Mohammad Minhajuddin
- Division of Hematology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Amanda Winters
- Division of Pediatric Hematology and Oncology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Regan Miller
- Division of Hematology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Ian Shelton
- Division of Hematology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Jonathan St-Germain
- Princess Margaret Cancer Centre, University Health Network, Toronto, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Canada
| | - Tianyi Ling
- Princess Margaret Cancer Centre, University Health Network, Toronto, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Canada
| | - Courtney Jones
- Princess Margaret Cancer Centre, University Health Network, Toronto, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Canada
| | - Brian Raught
- Princess Margaret Cancer Centre, University Health Network, Toronto, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Canada
| | - Austin Gillen
- Division of Hematology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Monica Ransom
- Division of Hematology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Sarah Staggs
- Division of Hematology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Clayton A. Smith
- Division of Hematology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Daniel A. Pollyea
- Division of Hematology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Brett M. Stevens
- Division of Hematology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Craig T. Jordan
- Division of Hematology, University of Colorado School of Medicine, Aurora, CO, USA
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2
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Ancar R, Li Y, Kindler E, Cooper DA, Ransom M, Thiel V, Weiss SR, Hesselberth JR, Barton DJ. Physiologic RNA targets and refined sequence specificity of coronavirus EndoU. RNA 2020; 26:1976-1999. [PMID: 32989044 PMCID: PMC7668261 DOI: 10.1261/rna.076604.120] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 09/12/2020] [Indexed: 05/15/2023]
Abstract
Coronavirus EndoU inhibits dsRNA-activated antiviral responses; however, the physiologic RNA substrates of EndoU are unknown. In this study, we used mouse hepatitis virus (MHV)-infected bone marrow-derived macrophage (BMM) and cyclic phosphate cDNA sequencing to identify the RNA targets of EndoU. EndoU targeted viral RNA, cleaving the 3' side of pyrimidines with a strong preference for U ↓ A and C ↓ A sequences (endoY ↓ A). EndoU-dependent cleavage was detected in every region of MHV RNA, from the 5' NTR to the 3' NTR, including transcriptional regulatory sequences (TRS). Cleavage at two CA dinucleotides immediately adjacent to the MHV poly(A) tail suggests a mechanism to suppress negative-strand RNA synthesis and the accumulation of viral dsRNA. MHV with EndoU (EndoUmut) or 2'-5' phosphodiesterase (PDEmut) mutations provoked the activation of RNase L in BMM, with corresponding cleavage of RNAs by RNase L. The physiologic targets of EndoU are viral RNA templates required for negative-strand RNA synthesis and dsRNA accumulation. Coronavirus EndoU cleaves U ↓ A and C ↓ A sequences (endoY ↓ A) within viral (+) strand RNA to evade dsRNA-activated host responses.
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Affiliation(s)
- Rachel Ancar
- Department of Biochemistry and Molecular Genetics, Program in Molecular Biology, School of Medicine, University of Colorado, Aurora 80045, Colorado, USA
| | - Yize Li
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Eveline Kindler
- Institute of Virology and Immunology IVI, 3001 Bern and 3147 Mittelhausern, Switzerland
- Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, 3012 Bern, Switzerland
| | - Daphne A Cooper
- Department of Immunology and Microbiology, School of Medicine, University of Colorado, Aurora, Colorado 80045, USA
| | - Monica Ransom
- Department of Biochemistry and Molecular Genetics, Program in Molecular Biology, School of Medicine, University of Colorado, Aurora 80045, Colorado, USA
| | - Volker Thiel
- Institute of Virology and Immunology IVI, 3001 Bern and 3147 Mittelhausern, Switzerland
- Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, 3012 Bern, Switzerland
| | - Susan R Weiss
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Jay R Hesselberth
- Department of Biochemistry and Molecular Genetics, Program in Molecular Biology, School of Medicine, University of Colorado, Aurora 80045, Colorado, USA
| | - David J Barton
- Department of Immunology and Microbiology, Program in Molecular Biology, School of Medicine, University of Colorado, Aurora, Colorado 80045, USA
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Aviles-Otero N, Ransom M, Weitkamp J, Charlton JR, Sullivan BA, Kaufman DA, Fairchild KD. Urinary tract infections in very low birthweight infants: A two-center analysis of microbiology, imaging and heart rate characteristics. J Neonatal Perinatal Med 2020; 14:269-276. [PMID: 33136069 DOI: 10.3233/npm-200513] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Increased understanding of characteristics of urinary tract infection (UTI) among very low birthweight infants (VLBW) might lead to improvement in detection and treatment. Continuous monitoring for abnormal heart rate characteristics (HRC) could provide early warning of UTIs. OBJECTIVE Describe the characteristics of UTI, including HRC, in VLBW infants. METHODS We reviewed records of VLBW infants admitted from 2005-2010 at two academic centers participating in a randomized clinical trial of HRC monitoring. Results of all urine cultures, renal ultrasounds (RUS), and voiding cystourethrograms (VCUG) were assessed. Change in the HRC index was analyzed before and after UTI. RESULTS Of 823 VLBW infants (27.7±2.9 weeks GA, 53% male), 378 had > / = 1 urine culture obtained. A UTI (≥10,000 CFU and >five days of antibiotics) was diagnosed in 80 infants, (10% prevalence, mean GA 25.8±2.0 weeks, 76% male). Prophylactic antibiotics were administered to 29 (36%) infants after UTI, of whom four (14%) had another UTI. Recurrent UTI also occurred in 7/51 (14%) of infants not on uroprophylaxis after their first UTI. RUS was performed after UTI in 78%, and hydronephrosis and other major anomalies were found in 19%. A VCUG was performed in 48% of infants and 18% demonstrated vesicoureteral reflux (VUR). The mean HRC rose and fell significantly in the two days before and after diagnosis of UTI. CONCLUSIONS UTI was diagnosed in 10% of VLBW infants, and the HRC index increased prior to diagnosis, suggesting that continuous HRC monitoring in the NICU might allow earlier diagnosis and treatment of UTI.
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Affiliation(s)
- N Aviles-Otero
- Department of Pediatrics, Division of Neonatology, University of Virginia, Charlottesville, VA, USA
| | - M Ransom
- Department of Pediatrics, Division of Neonatology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - J Weitkamp
- Department of Pediatrics, Division of Neonatology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - J R Charlton
- Department of Pediatrics, Division of Nephrology, University of Virginia, Charlottesville, VA, USA
| | - B A Sullivan
- Department of Pediatrics, Division of Neonatology, University of Virginia, Charlottesville, VA, USA
| | - D A Kaufman
- Department of Pediatrics, Division of Neonatology, University of Virginia, Charlottesville, VA, USA
| | - K D Fairchild
- Department of Pediatrics, Division of Neonatology, University of Virginia, Charlottesville, VA, USA
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LaRivière WB, Liao S, McMurtry SA, Oshima K, Han X, Zhang F, Yan S, Haeger SM, Ransom M, Bastarache JA, Linhardt RJ, Schmidt EP, Yang Y. Alveolar heparan sulfate shedding impedes recovery from bleomycin-induced lung injury. Am J Physiol Lung Cell Mol Physiol 2020; 318:L1198-L1210. [PMID: 32320623 DOI: 10.1152/ajplung.00063.2020] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The pulmonary epithelial glycocalyx, an anionic cell surface layer enriched in glycosaminoglycans such as heparan sulfate and chondroitin sulfate, contributes to the alveolar barrier. Direct injury to the pulmonary epithelium induces shedding of heparan sulfate into the air space; the impact of this shedding on recovery after lung injury is unknown. Using mass spectrometry, we found that heparan sulfate was shed into the air space for up to 3 wk after intratracheal bleomycin-induced lung injury and coincided with induction of matrix metalloproteinases (MMPs), including MMP2. Delayed inhibition of metalloproteinases, beginning 7 days after bleomycin using the nonspecific MMP inhibitor doxycycline, attenuated heparan sulfate shedding and improved lung function, suggesting that heparan sulfate shedding may impair lung recovery. While we also observed an increase in air space heparanase activity after bleomycin, pharmacological and transgenic inhibition of heparanase in vivo failed to attenuate heparan sulfate shedding or protect against bleomycin-induced lung injury. However, experimental augmentation of airway heparanase activity significantly worsened post-bleomycin outcomes, confirming the importance of epithelial glycocalyx integrity to lung recovery. We hypothesized that MMP-associated heparan sulfate shedding contributed to delayed lung recovery, in part, by the release of large, highly sulfated fragments that sequestered lung-reparative growth factors such as hepatocyte growth factor. In vitro, heparan sulfate bound hepatocyte growth factor and attenuated growth factor signaling, suggesting that heparan sulfate shed into the air space after injury may directly impair lung repair. Accordingly, administration of exogenous heparan sulfate to mice after bleomycin injury increased the likelihood of death due to severe lung dysfunction. Together, our findings demonstrate that alveolar epithelial heparan sulfate shedding impedes lung recovery after bleomycin.
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Affiliation(s)
- W B LaRivière
- Medical Scientist Training Program, University of Colorado School of Medicine, Aurora, Colorado.,Department of Pharmacology, University of Colorado School of Medicine, Aurora, Colorado.,Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado
| | - S Liao
- Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado
| | - S A McMurtry
- Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado
| | - K Oshima
- Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado
| | - X Han
- Department of Chemistry, Rensselaer Polytechnic Institute, Troy, New York
| | - F Zhang
- Department of Chemistry, Rensselaer Polytechnic Institute, Troy, New York
| | - S Yan
- Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado.,College of Life Sciences, Henan Normal University, Xinxiang, China
| | - S M Haeger
- Medical Scientist Training Program, University of Colorado School of Medicine, Aurora, Colorado.,Department of Pharmacology, University of Colorado School of Medicine, Aurora, Colorado.,Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado
| | - M Ransom
- Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado
| | - J A Bastarache
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee
| | - R J Linhardt
- Department of Chemistry, Rensselaer Polytechnic Institute, Troy, New York
| | - E P Schmidt
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, Colorado.,Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado.,Department of Medicine, Denver Health Medical Center, Denver, Colorado
| | - Y Yang
- Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado
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5
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Riemondy KA, Ransom M, Alderman C, Gillen AE, Fu R, Finlay-Schultz J, Kirkpatrick GD, Di Paola J, Kabos P, Sartorius CA, Hesselberth JR. Recovery and analysis of transcriptome subsets from pooled single-cell RNA-seq libraries. Nucleic Acids Res 2019; 47:e20. [PMID: 30496484 PMCID: PMC6393243 DOI: 10.1093/nar/gky1204] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 11/10/2018] [Accepted: 11/19/2018] [Indexed: 01/09/2023] Open
Abstract
Single-cell RNA sequencing (scRNA-seq) methods generate sparse gene expression profiles for thousands of single cells in a single experiment. The information in these profiles is sufficient to classify cell types by distinct expression patterns but the high complexity of scRNA-seq libraries often prevents full characterization of transcriptomes from individual cells. To extract more focused gene expression information from scRNA-seq libraries, we developed a strategy to physically recover the DNA molecules comprising transcriptome subsets, enabling deeper interrogation of the isolated molecules by another round of DNA sequencing. We applied the method in cell-centric and gene-centric modes to isolate cDNA fragments from scRNA-seq libraries. First, we resampled the transcriptomes of rare, single megakaryocytes from a complex mixture of lymphocytes and analyzed them in a second round of DNA sequencing, yielding up to 20-fold greater sequencing depth per cell and increasing the number of genes detected per cell from a median of 1313 to 2002. We similarly isolated mRNAs from targeted T cells to improve the reconstruction of their VDJ-rearranged immune receptor mRNAs. Second, we isolated CD3D mRNA fragments expressed across cells in a scRNA-seq library prepared from a clonal T cell line, increasing the number of cells with detected CD3D expression from 59.7% to 100%. Transcriptome resampling is a general approach to recover targeted gene expression information from single-cell RNA sequencing libraries that enhances the utility of these costly experiments, and may be applicable to the targeted recovery of molecules from other single-cell assays.
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Affiliation(s)
- Kent A Riemondy
- RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Monica Ransom
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Christopher Alderman
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Austin E Gillen
- RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Rui Fu
- RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Jessica Finlay-Schultz
- Department of Pathology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Gregory D Kirkpatrick
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Jorge Di Paola
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Peter Kabos
- Division of Medical Oncology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Carol A Sartorius
- Department of Pathology, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Jay R Hesselberth
- RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, CO 80045, USA.,Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, CO 80045, USA
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6
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Abstract
Modification of DNA nucleobases has a profound effect on genome function. We developed a method that maps the positions of the modified DNA nucleobases throughout genomic DNA. This method couples in vitro nucleobase excision with massively parallel DNA sequencing to determine the location of modified DNA nucleobases with single base precision. This protocol was used to map uracil incorporation and UV photodimers in DNA, and a modification of the protocol has been used to map sparse modification events in cells. The Excision-seq protocol is broadly applicable to a variety of base modifications for which an excision enzyme is available.
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Affiliation(s)
- Monica Ransom
- Department of Biochemistry and Molecular Genetics, Program in Molecular Biology, University of Colorado School of Medicine, Aurora, CO, 80045, USA
| | - D Suzi Bryan
- Department of Biochemistry and Molecular Genetics, Program in Molecular Biology, University of Colorado School of Medicine, Aurora, CO, 80045, USA
| | - Jay R Hesselberth
- Department of Biochemistry and Molecular Genetics, Program in Molecular Biology, University of Colorado School of Medicine, Aurora, CO, 80045, USA.
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7
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Hansen EC, Ransom M, Hesselberth JR, Hosmane NN, Capoferri AA, Bruner KM, Pollack RA, Zhang H, Drummond MB, Siliciano JM, Siliciano R, Stivers JT. Diverse fates of uracilated HIV-1 DNA during infection of myeloid lineage cells. eLife 2016; 5. [PMID: 27644592 PMCID: PMC5030084 DOI: 10.7554/elife.18447] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 08/23/2016] [Indexed: 12/22/2022] Open
Abstract
We report that a major subpopulation of monocyte-derived macrophages (MDMs) contains high levels of dUTP, which is incorporated into HIV-1 DNA during reverse transcription (U/A pairs), resulting in pre-integration restriction and post-integration mutagenesis. After entering the nucleus, uracilated viral DNA products are degraded by the uracil base excision repair (UBER) machinery with less than 1% of the uracilated DNA successfully integrating. Although uracilated proviral DNA showed few mutations, the viral genomic RNA was highly mutated, suggesting that errors occur during transcription. Viral DNA isolated from blood monocytes and alveolar macrophages (but not T cells) of drug-suppressed HIV-infected individuals also contained abundant uracils. The presence of viral uracils in short-lived monocytes suggests their recent infection through contact with virus producing cells in a tissue reservoir. These findings reveal new elements of a viral defense mechanism involving host UBER that may be relevant to the establishment and persistence of HIV-1 infection. DOI:http://dx.doi.org/10.7554/eLife.18447.001 Human immunodeficiency virus type 1 (HIV-1) infects and kills immune cells known as CD4+ T cells, leading to the disease AIDS. Current drug treatments enable HIV-1 infected patients to live relatively long and healthy lives. However, no cure for HIV-1 exists because the virus lives indefinitely in a resting state within the genetic material – or genome – of the infected cell, where it is not susceptible to drug treatments. Most HIV-1 research focuses on T cells, but another type of immune cell – the macrophage – may also harbor resting HIV-1 in its genome. Compared to other cells, macrophages are unusual because they produce large amounts of a molecule called deoxyuridine triphosphate (dUTP). Most cells, including T cells, keep dUTP levels very low because it closely resembles molecules that are used to make DNA and so it can be accidentally incorporated into the cell’s DNA. When this happens, the cell removes the dUTP from the DNA using enzymes in a process called uracil base excision repair (UBER). To hide inside the cell’s genome, HIV-1 needs to produce a DNA copy of its own genome, but it was not known what happens when HIV-1 tries to do this within a macrophage that contains high levels of dUTP and UBER enzymes. Here, Hansen et al. reveal that about 90% of macrophages have exceptionally high levels of dUTP and are poorly infected by HIV-1. The high levels of dUTP result in the virus incorporating dUTP into its DNA, which is then attacked and fragmented by UBER enzymes. However, about one in a hundred viral DNA molecules do manage to successfully integrate into the genome of the macrophage. This viral DNA later gives rise to new virus particles through an error-prone process that, by introducing new mutations into the virus genome, may help HIV-1 to evolve and persist. Further experiments examined cells that give rise to macrophages from infected patients who had been on anti-HIV drug therapy for several years. Hansen et al. found that there was lots of dUTP in the DNA sequences of HIV-1 viruses found in these “precursor” cells. These precursor cells only live for several days before being eliminated, so the presence of viruses containing dUTP suggests these cells were infected recently. A future challenge will be to identify new anti-HIV drugs that specifically target macrophages and to understand the role of error-prone production of new viral genomes. DOI:http://dx.doi.org/10.7554/eLife.18447.002
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Affiliation(s)
- Erik C Hansen
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, United States
| | - Monica Ransom
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, United States
| | - Jay R Hesselberth
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, United States
| | - Nina N Hosmane
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, United States
| | - Adam A Capoferri
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, United States.,Howard Hughes Medical Institute, The Johns Hopkins School of Medicine, Baltimore, United States
| | - Katherine M Bruner
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, United States
| | - Ross A Pollack
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, United States
| | - Hao Zhang
- W Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, United States
| | - Michael Bradley Drummond
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, United States
| | - Janet M Siliciano
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, United States
| | - Robert Siliciano
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, United States.,Howard Hughes Medical Institute, The Johns Hopkins School of Medicine, Baltimore, United States
| | - James T Stivers
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, United States
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8
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Bryan DS, Ransom M, Adane B, York K, Hesselberth JR. High resolution mapping of modified DNA nucleobases using excision repair enzymes. Genome Res 2014; 24:1534-42. [PMID: 25015380 PMCID: PMC4158761 DOI: 10.1101/gr.174052.114] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 07/08/2014] [Indexed: 12/20/2022]
Abstract
The incorporation and creation of modified nucleobases in DNA have profound effects on genome function. We describe methods for mapping positions and local content of modified DNA nucleobases in genomic DNA. We combined in vitro nucleobase excision with massively parallel DNA sequencing (Excision-seq) to determine the locations of modified nucleobases in genomic DNA. We applied the Excision-seq method to map uracil in E. coli and budding yeast and discovered significant variation in uracil content, wherein uracil is excluded from the earliest and latest replicating regions of the genome, possibly driven by changes in nucleotide pool composition. We also used Excision-seq to identify sites of pyrimidine dimer formation induced by UV light exposure, where the method could distinguish between sites of cyclobutane and 6-4 photoproduct formation. These UV mapping data enabled analysis of local sequence bias around pyrimidine dimers and suggested a preference for an adenosine downstream from 6-4 photoproducts. The Excision-seq method is broadly applicable for high precision, genome-wide mapping of modified nucleobases with cognate repair enzymes.
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Affiliation(s)
- D Suzi Bryan
- Department of Biochemistry and Molecular Genetics, Program in Molecular Biology, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
| | - Monica Ransom
- Department of Biochemistry and Molecular Genetics, Program in Molecular Biology, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
| | - Biniam Adane
- Department of Biochemistry and Molecular Genetics, Program in Molecular Biology, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
| | - Kerri York
- Department of Biochemistry and Molecular Genetics, Program in Molecular Biology, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
| | - Jay R Hesselberth
- Department of Biochemistry and Molecular Genetics, Program in Molecular Biology, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
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9
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Invernizzi P, Ransom M, Raychaudhuri S, Kosoy R, Lleo A, Shigeta R, Franke A, Bossa F, Amos CI, Gregersen PK, Siminovitch KA, Cusi D, de Bakker PIW, Podda M, Gershwin ME, Seldin MF. Classical HLA-DRB1 and DPB1 alleles account for HLA associations with primary biliary cirrhosis. Genes Immun 2012; 13:461-8. [PMID: 22573116 PMCID: PMC3423484 DOI: 10.1038/gene.2012.17] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Susceptibility to primary biliary cirrhosis (PBC) is strongly associated with HLA region polymorphisms. To determine if associations can be explained by classical HLA determinants we studied Italian 676 cases and 1440 controls with genotyped with dense single nucleotide polymorphisms (SNPs) for which classical HLA alleles and amino acids were imputed. Although previous genome-wide association studies and our results show stronger SNP associations near DQB1, we demonstrate that the HLA signals can be attributed to classical DRB1 and DPB1 genes. Strong support for the predominant role of DRB1 is provided by our conditional analyses. We also demonstrate an independent association of DPB1. Specific HLA-DRB1 genes (*08, *11 and *14) account for most of the DRB1 association signal. Consistent with previous studies, DRB1*08 (p = 1.59 × 10−11) was the strongest predisposing allele where as DRB1*11 (p = 1.42 × 10−10) was protective. Additionally DRB1*14 and the DPB1 association (DPB1*03:01) (p = 9.18 × 10−7) were predisposing risk alleles. No signal was observed in the HLA class 1 or class 3 regions. These findings better define the association of PBC with HLA and specifically support the role of classical HLA-DRB1 and DPB1 genes and alleles in susceptibility to PBC.
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Affiliation(s)
- P Invernizzi
- Department of Medicine, Division of Rheumatology, Allergy and Clinical Immunology, University of California at Davis, Davis, CA 95616, USA
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Kosoy R, Ransom M, Chen H, Marconi M, Macciardi F, Glorioso N, Gregersen PK, Cusi D, Seldin MF. Evidence for malaria selection of a CR1 haplotype in Sardinia. Genes Immun 2011; 12:582-8. [PMID: 21593778 DOI: 10.1038/gene.2011.33] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Complement receptor 1 (CR1) levels have been associated with malarial susceptibility and/or severity of the disease in different population groups, and CR1 is a receptor for Plasmodium falciparum. In this study, multiple CR1 single-nucleotide polymorphisms (SNPs) showed strong evidence of population differentiation between Sardinian and other European ethnic groups. Cross population algorithms comparing haplotype structure and differences in haplotype and allele frequency distribution provided additional support for natural selection of CR1 in Sardinia. The predominant Sardinian CR1 haplotype included SNPs that are associated with decreased CR1 levels in Europeans and other population groups. Previous studies have shown that the SNPs within the dominant Sardinian haplotype have a significantly higher frequency in a malaria endemic compared with non-endemic regions in India. Together with the historical evidence of the prevalence of malaria in Sardinia, these data support the role of malaria leading to positive selection of this CR1 haplotype in Sardinia.
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Affiliation(s)
- R Kosoy
- Department of Biochemistry and Molecular Medicine, Rowe Program in Human Genetics, University of California, Davis, CA 95616, USA
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Abstract
Nuclear DNA is tightly packaged into chromatin, which profoundly influences DNA replication, transcription, repair, and recombination. The extensive interactions between the basic histone proteins and acidic DNA make the nucleosomal unit of chromatin a highly stable entity. For the cellular machinery to access the DNA, the chromatin must be unwound and the DNA cleared of histone proteins. Conversely, the DNA has to be repackaged into chromatin afterward. This review focuses on the roles of the histone chaperones in assembling and disassembling chromatin during the processes of DNA replication and repair.
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Affiliation(s)
- Monica Ransom
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, CO 80045, USA
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12
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Ransom M, Williams SK, Dechassa ML, Das C, Linger J, Adkins M, Liu C, Bartholomew B, Tyler JK. FACT and the proteasome promote promoter chromatin disassembly and transcriptional initiation. J Biol Chem 2009; 284:23461-71. [PMID: 19574230 DOI: 10.1074/jbc.m109.019562] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The packaging of the eukaryotic genome into chromatin represses gene expression by blocking access of the general transcription machinery to the underlying DNA sequences. Accordingly, eukaryotes have developed a variety of mechanisms to disrupt, alter, or disassemble nucleosomes from promoter regions and open reading frames to allow transcription to occur. Although we know that chromatin disassembly from the yeast PHO5 promoter is triggered by the Pho4 activator, the mechanism is far from clear. Here we show that the Pho4 activator can occupy its nucleosome-bound DNA binding site within the PHO5 promoter. In contrast to the role of Saccharomyces cerevisiae FACT (facilitates chromatin transcription) complex in assembling chromatin within open reading frames, we find that FACT is involved in the disassembly of histones H2A/H2B from the PHO5 promoter during transcriptional induction. We have also discovered that the proteasome is required for efficient chromatin disassembly and transcriptional induction from the PHO5 promoter. Mutants of the degradation function of the proteasome have a defect in recruitment of the Pho4 activator, whereas mutants of the ATPase cap of the proteasome do recruit Pho4 but are still delayed for chromatin assembly. Finally, we rule out the possibility that the proteasome or ATPase cap is driving chromatin disassembly via a potential ATP-dependent chromatin remodeling activity.
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Affiliation(s)
- Monica Ransom
- Department of Biochemistry, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
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Davis P, McLeod K, Ransom M, Ongley P, Pearce N, Howden-Chapman P. The New Zealand Socioeconomic Index: developing and validating an occupationally-derived indicator of socio-economic status. Aust N Z J Public Health 1999; 23:27-33. [PMID: 10083686 DOI: 10.1111/j.1467-842x.1999.tb01201.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
OBJECTIVE Following revision of the international standard classification (ISCO88), to update and validate on health data an occupationally derived indicator of socio-economic status (SES) adapted to changing occupational and demographic conditions. METHOD The development of the New Zealand Socioeconomic Index (NZSEI) is based on a 'returns to human capital' model of the stratification process and uses data from the 1991 New Zealand Census (n = 1,051, 926) to generate scores for 97 occupational groups. The construct validation of the scale is carried out on data from the 1992-93 nationwide Household Health Survey (n = 3,000) using three health indicators (self-assessed health, cigarette smoking, general practitioner visits). RESULTS In general, the results are consistent with expected socio-economic patterns drawn from the literature for the three indicators. CONCLUSIONS While further work is required on a number of methodological and conceptual issues, the NZSEI provides a robust, standardised and internationally comparable occupational scale of SES for both males and females in either full- or part-time employment. IMPLICATIONS The NZSEI can be used on routinely collected occupational data. It has a clear conceptual rationale, updates existing SES scales, and provides a link to international standards in SES and occupational classification.
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Affiliation(s)
- P Davis
- Department of Community Health, School of Medicine, University of Auckland, New Zealand.
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Abstract
OBJECTIVE To evaluate whether measures that lower cytosolic calcium (Ca) can reverse propranolol (PROP) toxicity in the isolated, perfused rat heart. METHODS Isolated rat hearts were perfused on a Langendorff apparatus with Krebs-Henseleit-bicarbonate (KHB) buffer solution. Toxicity was produced by perfusing the hearts with PROP (5 micrograms/mL) for 30 minutes. Subsequently, the hearts were treated for 30 minutes with buffer containing PROP plus experimental treatment. Three treatments were chosen: hypertonic sodium (Na) (160 mmol), to stimulate Na-Ca exchange, dantrolene (DAN) (10 mumol), to inhibit Ca release from sarcoplasmic reticulum, and combined hypertonic Na and DAN. The hearts were paced after 20 minutes of treatment. Heart rate (HR), left ventricular peak systolic pressure (LVP), the first derivative of LVP (dP/dt), and coronary flow were measured. RESULTS PROP decreased HR and rendered the hearts refractory to pacing. PROP did not alter dP/dt. PROP increased LVP consistent with increased cytosolic Ca. Combined hypertonic Na and DAN treatment restored the ability to pace PROP-toxic hearts to the basal HR. Individually, hypertonic Na or DAN treatment partially restored the ability to pace toxic hearts. As experimental treatments increased HR, dP/dt and LVP decreased, consistent with decreased cytosolic Ca availability. CONCLUSION These data are consistent with the hypothesis that bradycardia during beta-blocker cardiotoxicity is mediated by altered Ca homeostasis.
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Affiliation(s)
- W Kerns
- Department of Emergency Medicine, Carolinas Medical Center, Charlotte, NC 28232-2861, USA
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15
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Abstract
The mechanism of beta-blocker induced cardiotoxicity is poorly understood. One possible explanation is that beta-blockers induce ion dyshomeostasis, resulting in cardiac hyperpolarization. The intent of this study was to determine if modifying extracellular ions would reverse cardiotoxicity from two beta-blockers: propranolol (PROP) and atenolol (ATEN). Two treatments were studied: low extracellular K+ and high extracellular Na+. Isolated rat hearts were perfused on a Langendorff apparatus with Krebs-Henseleit- Bicarbonate buffer (KHB) solution. Toxicity (Tox) was induced by perfusing hearts for 30 min with KHB + PROP [5 microgram/ml] or KHB + ATEN [2.5 mg/ml]. Subsequently, hearts were perfused with KHB containing either PROP or ATEN, but modified by lowering K+ [2.3 mM] or raising Na+ [160 mM] for a 30-min treatment (Tx) period. Hearts were paced near the end of treatment. Cardiodynamics were monitored via a balloon-tipped catheter in the left ventricle. The first derivative of LV pressure (dP/dt) with respect to time served as our index of myocardial performance. Tx groups were as follows: (1) KHB only, (2) PROP only, (3) PROP + K, (4) PROP + Na, (5) ATEN only, (6) ATEN 4 K, and (7) ATEN + Na. PROP induced negative chronotropic effects and rendered the hearts refractory to pacing. ATEN demonstrated similar chronotropic toxicity plus decreased myocardial contractility. Tx with low extracellular K+ and high extracellular Na+ increased HR and restored the ability to pace, thereby reversing toxicity. These data suggest that beta-blocker toxicity is mediated via hyperpolarization.
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Affiliation(s)
- W Kerns
- Department of Emergency Medicine, Division of Toxicology, Carolinas Medical Center, Charlotte, North Carolina 28232-2861, USA
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Fourneau JP, Davy M, Clément M, Ransom M, Darmois F, Lamarche M. Studies on the effects of piridoxilate, a glyoxylic acid derivative, on the mammalian system, heart and muscle under normal or deficient oxygen supply. Attempts towards a biochemical approach. Arzneimittelforschung 1974; 24:27-34. [PMID: 4406105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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