1
|
McNulty AM, Burke T, Dempsey JA, Marchal CC, Schade AE, Szpurka HP, Dowless MS, Stephens J, Stephens J, Edmondson D, Stayrook K, Caldwell WC, Buchanan S, Merzoug FF, Beckmann RP. Abstract A12: The CDK4/CDK6 inhibitor abemaciclib inhibits transcriptional targets which facilitate growth in ER+ breast cancer cells. Mol Cancer Res 2016. [DOI: 10.1158/1557-3125.cellcycle16-a12] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Abemaciclib (LY2835219) is an ATP-competitive inhibitor of cyclin dependent kinases 4 and 6 (CDK4/6), which is currently undergoing clinical evaluation as a single-agent treatment and in combination with the anti-hormonal therapy (SERD) fulvestrant in estrogen receptor positive (ER+) breast cancer (BrCa). Breast cancer cell line (15 lines) sensitivity to treatment with abemaciclib was assessed using multiple approaches including EdU incorporation, phosphorylation of retinoblastoma protein at serine 807/811 (pRb_s807/811) and RNA transcriptional profiling. We identified molecular features including ER-positivity (ER+), and luminal histology, as key to greater sensitivity while loss of Rb was associated with lower sensitivity. Changes in the Modaplex based RNA transcriptional array profiles of 29 cell cycle related target genes across a panel of 15 human breast cancer cell lines further characterized sensitivity to abemaciclib and highlighted potential targets of response. A sub-group of targets including MKi67, E2F1, MCM7, FOXM1, RRM2 and TOPIIα were significantly inhibited in highly sensitive cell lines previously characterized with EC50 < 50nM (EdU, pRb_serine 807/811). Additionally, we looked at abemaciclib induced transcriptional changes in vivo treating nude mice bearing human, ER+ breast cancer (ER+/HER2-) tumor xenografts and found that the inhibition of expression of this same group of transcriptional targets plus CCNE1 and CDKN2C correlated with the concentration-dependent inhibition of CDK4/CDK6. Abemaciclib washout studies following longer-term exposure in T47-D (ER+/HER2-) demonstrated durable cell cycle inhibition resulting in significant inhibition of pRb_s807/811 even after the removal (washout) of abemaciclib while longer exposure also resulted in inhibition of estrogen receptor-α (ERα) expression in a panel of ER+ breast cancer cell lines that were evaluated over a 8 day time course.
Using taqman low density RNA array (TLDA) cards designed with known ERα driven transcriptional targets, we investigated the impact of abemaciclib single agent and in combination with fulvestrant on changes in RNA expression in four day treated breast cancer cells (ER+/HER2-). Single agent abemaciclib appeared to inhibit a subset of ERα driven targets including TFF1, GREB1, ESR1, E2F1, CDC45, FOXM1 and IGFBP4 (inhibition >%50). Interestingly, comparing single agent (% inhibition) abemaciclib to fulvestrant monotherapy in MCF-7 cells, we found that abemaciclib inhibited CDC45, E2F1, ESR1 and FOXM1 to a greater extent than that observed for these same targets following monotherapy with fulvestrant. Combining abemaciclib with fulvestrant identified an additional sub-group of ERα driven targets whereby the combination provided greater inhibition than that observed with any of the single agent treatments (IGFBP4, E2F1, FOXM1 and CDC45). Additionally, the combination treatment as compared to single-agent treatments also induced greater inhibition of various cell cycle regulatory genes including MCM7, CDKN2C, TOP2a, RRM2, and MKi67.
Citation Format: Ann M. McNulty, Teresa Burke, Jack A. Dempsey, Christophe C. Marchal, Andrew E. Schade, Hadrian P. Szpurka, Michele S. Dowless, Jennifer Stephens, Jennifer Stephens, Denise Edmondson, Keith Stayrook, William C. Caldwell, Sean Buchanan, Farhana F. Merzoug, Richard P. Beckmann. The CDK4/CDK6 inhibitor abemaciclib inhibits transcriptional targets which facilitate growth in ER+ breast cancer cells. [abstract]. In: Proceedings of the AACR Precision Medicine Series: Cancer Cell Cycle - Tumor Progression and Therapeutic Response; Feb 28-Mar 2, 2016; Orlando, FL. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(11_Suppl):Abstract nr A12.
Collapse
|
2
|
Tonsing-Carter E, Bailey BJ, Saadatzadeh MR, Ding J, Wang H, Sinn AL, Peterman KM, Spragins TK, Silver JM, Sprouse AA, Georgiadis TM, Gunter TZ, Long EC, Minto RE, Marchal CC, Batuello CN, Safa AR, Hanenberg H, Territo PR, Sandusky GE, Mayo LD, Eischen CM, Shannon HE, Pollok KE. Potentiation of Carboplatin-Mediated DNA Damage by the Mdm2 Modulator Nutlin-3a in a Humanized Orthotopic Breast-to-Lung Metastatic Model. Mol Cancer Ther 2015; 14:2850-63. [PMID: 26494859 DOI: 10.1158/1535-7163.mct-15-0237] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 09/30/2015] [Indexed: 12/31/2022]
Abstract
Triple-negative breast cancers (TNBC) are typically resistant to treatment, and strategies that build upon frontline therapy are needed. Targeting the murine double minute 2 (Mdm2) protein is an attractive approach, as Mdm2 levels are elevated in many therapy-refractive breast cancers. The Mdm2 protein-protein interaction inhibitor Nutlin-3a blocks the binding of Mdm2 to key signaling molecules such as p53 and p73α and can result in activation of cell death signaling pathways. In the present study, the therapeutic potential of carboplatin and Nutlin-3a to treat TNBC was investigated, as carboplatin is under evaluation in clinical trials for TNBC. In mutant p53 TMD231 TNBC cells, carboplatin and Nutlin-3a led to increased Mdm2 and was strongly synergistic in promoting cell death in vitro. Furthermore, sensitivity of TNBC cells to combination treatment was dependent on p73α. Following combination treatment, γH2AX increased and Mdm2 localized to a larger degree to chromatin compared with single-agent treatment, consistent with previous observations that Mdm2 binds to the Mre11/Rad50/Nbs1 complex associated with DNA and inhibits the DNA damage response. In vivo efficacy studies were conducted in the TMD231 orthotopic mammary fat pad model in NOD.Cg-Prkdc(scid)Il2rg(tm1Wjl)/SzJ (NSG) mice. Using an intermittent dosing schedule of combined carboplatin and Nutlin-3a, there was a significant reduction in primary tumor growth and lung metastases compared with vehicle and single-agent treatments. In addition, there was minimal toxicity to the bone marrow and normal tissues. These studies demonstrate that Mdm2 holds promise as a therapeutic target in combination with conventional therapy and may lead to new clinical therapies for TNBC.
Collapse
Affiliation(s)
- Eva Tonsing-Carter
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Barbara J Bailey
- In Vivo Therapeutics Core, Indiana University Melvin and Bren Simon Cancer Center, Indiana University School of Medicine, Indianapolis, Indiana. Department of Pediatrics, Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana
| | - M Reza Saadatzadeh
- Department of Pediatrics, Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana. Goodman Campbell Brain and Spine, Department of Neurosurgery, Indiana University School of Medicine, Indianapolis, Indiana
| | - Jixin Ding
- Department of Pediatrics, Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana. Goodman Campbell Brain and Spine, Department of Neurosurgery, Indiana University School of Medicine, Indianapolis, Indiana
| | - Haiyan Wang
- Department of Pediatrics, Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana
| | - Anthony L Sinn
- In Vivo Therapeutics Core, Indiana University Melvin and Bren Simon Cancer Center, Indiana University School of Medicine, Indianapolis, Indiana
| | - Kacie M Peterman
- In Vivo Therapeutics Core, Indiana University Melvin and Bren Simon Cancer Center, Indiana University School of Medicine, Indianapolis, Indiana
| | - Tiaishia K Spragins
- In Vivo Therapeutics Core, Indiana University Melvin and Bren Simon Cancer Center, Indiana University School of Medicine, Indianapolis, Indiana
| | - Jayne M Silver
- In Vivo Therapeutics Core, Indiana University Melvin and Bren Simon Cancer Center, Indiana University School of Medicine, Indianapolis, Indiana
| | - Alyssa A Sprouse
- Department of Pediatrics, Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana
| | - Taxiarchis M Georgiadis
- Department of Chemistry and Chemical Biology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana
| | - T Zachary Gunter
- Department of Chemistry and Chemical Biology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana
| | - Eric C Long
- Department of Chemistry and Chemical Biology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana
| | - Robert E Minto
- Department of Chemistry and Chemical Biology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana
| | - Christophe C Marchal
- Department of Pediatrics, Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana
| | - Christopher N Batuello
- Department of Pediatrics, Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana
| | - Ahmad R Safa
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Helmut Hanenberg
- Department of Pediatrics, Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana. Department of Medical & Molecular Genetics, Indiana University School of Medicine, Indianapolis, Indiana. Department of Otorhinolaryngology and Head/Neck Surgery, Heinrich Heine University, Düsseldorf, Germany
| | - Paul R Territo
- Indiana Institute for Biomedical Sciences Imaging, Department of Radiology, Indiana University School of Medicine, Indianapolis, Indiana
| | - George E Sandusky
- Department of Pathology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Lindsey D Mayo
- Department of Pediatrics, Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana. Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Christine M Eischen
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Harlan E Shannon
- Department of Pediatrics, Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana
| | - Karen E Pollok
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana. In Vivo Therapeutics Core, Indiana University Melvin and Bren Simon Cancer Center, Indiana University School of Medicine, Indianapolis, Indiana. Department of Pediatrics, Herman B Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, Indiana.
| |
Collapse
|
3
|
Gruver AM, Liu L, Vaillancourt P, Yan SB, Cook JD, Roseberry Baker JA, Felke EM, Lacy ME, Marchal CC, Szpurka H, Holzer TR, Rhoads EK, Zeng W, Wortinger MA, Lu J, Chow C, Denning IJ, Beuerlein G, Davies J, Hanson JC, Credille KM, Wijayawardana SR, Schade AE. Immunohistochemical application of a highly sensitive and specific murine monoclonal antibody recognising the extracellular domain of the human hepatocyte growth factor receptor (
MET
). Histopathology 2014; 65:879-96. [DOI: 10.1111/his.12510] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Accepted: 07/12/2014] [Indexed: 01/07/2023]
Affiliation(s)
- Aaron M Gruver
- Lilly Research Laboratories Eli Lilly and Company Indianapolis IN USA
| | - Ling Liu
- Lilly Research Laboratories Eli Lilly and Company Indianapolis IN USA
| | | | - Sau‐Chi B Yan
- Lilly Research Laboratories Eli Lilly and Company Indianapolis IN USA
| | - Joel D Cook
- Lilly Research Laboratories Eli Lilly and Company Indianapolis IN USA
| | | | - Erin M Felke
- Lilly Research Laboratories Eli Lilly and Company Indianapolis IN USA
| | - Megan E Lacy
- Lilly Research Laboratories Eli Lilly and Company Indianapolis IN USA
| | | | - Hadrian Szpurka
- Lilly Research Laboratories Eli Lilly and Company Indianapolis IN USA
| | - Timothy R. Holzer
- Lilly Research Laboratories Eli Lilly and Company Indianapolis IN USA
| | - Emily K Rhoads
- Lilly Research Laboratories Eli Lilly and Company Indianapolis IN USA
| | - Wei Zeng
- Lilly Research Laboratories Eli Lilly and Company Indianapolis IN USA
| | - Mark A Wortinger
- Lilly Research Laboratories Eli Lilly and Company Indianapolis IN USA
| | - Jirong Lu
- Lilly Research Laboratories Eli Lilly and Company Indianapolis IN USA
| | - Chi‐kin Chow
- Lilly Research Laboratories Eli Lilly and Company Indianapolis IN USA
| | - Irene J Denning
- Lilly Research Laboratories Eli Lilly and Company Indianapolis IN USA
| | - Gregory Beuerlein
- Lilly Research Laboratories Eli Lilly and Company Indianapolis IN USA
| | - Julian Davies
- Lilly Research Laboratories Eli Lilly and Company Indianapolis IN USA
| | - Jeff C Hanson
- Lilly Research Laboratories Eli Lilly and Company Indianapolis IN USA
| | - Kelly M Credille
- Lilly Research Laboratories Eli Lilly and Company Indianapolis IN USA
| | | | - Andrew E Schade
- Lilly Research Laboratories Eli Lilly and Company Indianapolis IN USA
| |
Collapse
|
4
|
Bustamante J, Arias AA, Vogt G, Picard C, Galicia LB, Prando C, Grant AV, Marchal CC, Hubeau M, Chapgier A, de Beaucoudrey L, Puel A, Feinberg J, Valinetz E, Jannière L, Besse C, Boland A, Brisseau JM, Blanche S, Lortholary O, Fieschi C, Emile JF, Boisson-Dupuis S, Al-Muhsen S, Woda B, Newburger PE, Condino-Neto A, Dinauer MC, Abel L, Casanova JL. Germline CYBB mutations that selectively affect macrophages in kindreds with X-linked predisposition to tuberculous mycobacterial disease. Nat Immunol 2011; 12:213-21. [PMID: 21278736 DOI: 10.1038/ni.1992] [Citation(s) in RCA: 203] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2010] [Accepted: 12/31/2010] [Indexed: 12/31/2022]
Abstract
Germline mutations in CYBB, the human gene encoding the gp91(phox) subunit of the phagocyte NADPH oxidase, impair the respiratory burst of all types of phagocytes and result in X-linked chronic granulomatous disease (CGD). We report here two kindreds in which otherwise healthy male adults developed X-linked recessive Mendelian susceptibility to mycobacterial disease (MSMD) syndromes. These patients had previously unknown mutations in CYBB that resulted in an impaired respiratory burst in monocyte-derived macrophages but not in monocytes or granulocytes. The macrophage-specific functional consequences of the germline mutation resulted from cell-specific impairment in the assembly of the NADPH oxidase. This 'experiment of nature' indicates that CYBB is associated with MSMD and demonstrates that the respiratory burst in human macrophages is a crucial mechanism for protective immunity to tuberculous mycobacteria.
Collapse
Affiliation(s)
- Jacinta Bustamante
- Laboratory of Human Genetics of Infectious Diseases, Necker Branch, Institut National de la Santé et de la Recherche Médicale, U980, Paris, France
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
5
|
Li XJ, Marchal CC, Stull ND, Stahelin RV, Dinauer MC. p47phox Phox homology domain regulates plasma membrane but not phagosome neutrophil NADPH oxidase activation. J Biol Chem 2010; 285:35169-79. [PMID: 20817944 DOI: 10.1074/jbc.m110.164475] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The assembly of cytosolic subunits p47(phox), p67(phox), and p40(phox) with flavocytochrome b(558) at the membrane is required for activating the neutrophil NADPH oxidase that generates superoxide for microbial killing. The p47(phox) subunit plays a critical role in oxidase assembly. Recent studies showed that the p47(phox) Phox homology (PX) domain mediates phosphoinositide binding in vitro and regulates phorbol ester-induced NADPH oxidase activity in a K562 myeloid cell model. Because the importance of the p47(phox) PX domain in neutrophils is unclear, we investigated its role using p47(phox) knock-out (KO) mouse neutrophils to express human p47(phox) and derivatives harboring R90A mutations in the PX domain that result in loss of phosphoinositide binding. Human p47(phox) proteins were expressed at levels similar to endogenous murine p47(phox), with the exception of a chronic granulomatous disease-associated R42Q mutant that was poorly expressed, and wild type human p47(phox) rescued p47(phox) KO mouse neutrophil NADPH oxidase activity. Plasma membrane NAPDH oxidase activity was reduced in neutrophils expressing p47(phox) with Arg(90) substitutions, with substantial effects on responses to either phorbol ester or formyl-Met-Leu-Phe and more modest effects to particulate stimuli. In contrast, p47(phox) Arg(90) mutants supported normal levels of intracellular NADPH oxidase activity during phagocytosis of a variety of particles and were recruited to phagosome membranes. This study defines a differential and agonist-dependent role of the p47(phox) PX domain for neutrophil NADPH oxidase activation.
Collapse
Affiliation(s)
- Xing Jun Li
- From the Department of Pediatrics (Hematology/Oncology), Herman B Wells Center for Pediatric Research, Riley Hospital for Children, and
| | | | | | | | | |
Collapse
|
6
|
Matute JD, Arias AA, Wright NAM, Wrobel I, Waterhouse CCM, Li XJ, Marchal CC, Stull ND, Lewis DB, Steele M, Kellner JD, Yu W, Meroueh SO, Nauseef WM, Dinauer MC. A new genetic subgroup of chronic granulomatous disease with autosomal recessive mutations in p40 phox and selective defects in neutrophil NADPH oxidase activity. Blood 2009; 114:3309-15. [PMID: 19692703 PMCID: PMC2759653 DOI: 10.1182/blood-2009-07-231498] [Citation(s) in RCA: 277] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2009] [Accepted: 08/05/2009] [Indexed: 02/07/2023] Open
Abstract
Chronic granulomatous disease (CGD), an immunodeficiency with recurrent pyogenic infections and granulomatous inflammation, results from loss of phagocyte superoxide production by recessive mutations in any 1 of 4 genes encoding subunits of the phagocyte NADPH oxidase. These include gp91(phox) and p22(phox), which form the membrane-integrated flavocytochrome b, and cytosolic subunits p47(phox) and p67(phox). A fifth subunit, p40(phox), plays an important role in phagocytosis-induced superoxide production via a phox homology (PX) domain that binds to phosphatidylinositol 3-phosphate (PtdIns(3)P). We report the first case of autosomal recessive mutations in NCF4, the gene encoding p40(phox), in a boy who presented with granulomatous colitis. His neutrophils showed a substantial defect in intracellular superoxide production during phagocytosis, whereas extracellular release of superoxide elicited by phorbol ester or formyl-methionyl-leucyl-phenylalanine (fMLF) was unaffected. Genetic analysis of NCF4 showed compound heterozygosity for a frameshift mutation with premature stop codon and a missense mutation predicting a R105Q substitution in the PX domain. Parents and a sibling were healthy heterozygous carriers. p40(phox)R105Q lacked binding to PtdIns(3)P and failed to reconstitute phagocytosis-induced oxidase activity in p40(phox)-deficient granulocytes, with premature loss of p40(phox)R105Q from phagosomes. Thus, p40(phox) binding to PtdIns(3)P is essential for phagocytosis-induced oxidant production in human neutrophils and its absence can be associated with disease.
Collapse
Affiliation(s)
- Juan D Matute
- Wells Center for Pediatric Research, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Broxmeyer HE, Sehra S, Cooper S, Toney LM, Kusam S, Aloor JJ, Marchal CC, Dinauer MC, Dent AL. Aberrant regulation of hematopoiesis by T cells in BAZF-deficient mice. Mol Cell Biol 2007; 27:5275-85. [PMID: 17526724 PMCID: PMC1952080 DOI: 10.1128/mcb.01967-05] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The BAZF (BCL-6b) protein is highly similar to the BCL-6 transcriptional repressor. While BCL-6 has been characterized extensively, relatively little is known about the normal function of BAZF. In order to understand the physiological role of BAZF, we created BAZF-deficient mice. Unlike BCL-6-deficient mice, BAZF-deficient mice are healthy and normal in size. However, BAZF-deficient mice have a hematopoietic progenitor phenotype that is almost identical to that of BCL-6-deficient mice. Compared to wild-type mice, both BAZF-deficient and BCL-6-deficient mice have greatly reduced numbers of cycling hematopoietic progenitor cells (HPC) in the BM and greatly increased numbers of cycling HPC in the spleen. In contrast to HPC from wild-type mice, HPC from BAZF-deficient and BCL-6-deficient mice are resistant to chemokine-induced myelosuppression and do not show a synergistic growth response to granulocyte-macrophage colony-stimulating factor plus stem cell factor. Depletion of CD8 T cells in BAZF-deficient mice reverses several of the hematopoietic defects in these mice. Since both BAZF- and BCL-6-deficient mice have defects in CD8 T-cell differentiation, we hypothesize that both BCL-6 and BAZF regulate HPC homeostasis by an indirect pathway involving CD8 T cells.
Collapse
Affiliation(s)
- Hal E Broxmeyer
- Department of Microbiology and Immunology and The Walther Oncology Center, 950 W. Walnut St. R2 302, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Zhu Y, Marchal CC, Casbon AJ, Stull N, von Löhneysen K, Knaus UG, Jesaitis AJ, McCormick S, Nauseef WM, Dinauer MC. Deletion mutagenesis of p22phox subunit of flavocytochrome b558: identification of regions critical for gp91phox maturation and NADPH oxidase activity. J Biol Chem 2006; 281:30336-46. [PMID: 16895900 DOI: 10.1074/jbc.m607191200] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The heterodimeric flavocytochrome b558, comprised of the two integral membrane proteins p22phox and gp91phox, mediates the transfer of electrons from NADPH to molecular oxygen in the phagocyte NADPH oxidase to generate the superoxide precursor of microbicidal oxidants. This study uses deletion mutagenesis to identify regions of p22phox required for maturation of gp91phox and for NADPH oxidase activity. N-terminal, C-terminal, or internal deletions of human p22phox were generated and expressed in Chinese hamster ovary cells with transgenes for gp91phox and two other NADPH oxidase subunits, p47phox, and p67phox. The results demonstrate that p22phox-dependent maturation of gp91phox carbohydrate, cell surface expression of gp91phox, and the enzymatic function of flavocytochrome b558 are closely correlated. Whereas the 5 N-terminal and 25 C-terminal amino acids are dispensable for these functions, the N-terminal 11 amino acids of p22phox are required, as is a hydrophilic region between amino acids 65 and 90. Upon deletion of 54 residues at the C terminus of p22phox (amino acids 142-195), maturation and cell surface expression of gp91phox was still preserved, although NADPH oxidase activity was absent, as expected, due to removal of a proline-rich domain between amino acids 151-160 that is required for recruitment of p47phox. Antibody binding studies indicate that the extreme N terminus of p22phox is inaccessible in the absence of cell permeabilization, supporting a model in which both the N- and C-terminal domains of p22phox extend into the cytoplasm, anchored by two membrane-embedded regions.
Collapse
Affiliation(s)
- Yanmin Zhu
- Herman B. Wells Center for Pediatric Research, Department of Pediatrics (Hematology/Oncology), Microbiology/Immunology, and Medical and Molecular Genetics, James Whitcomb Riley Hospital for Children, Indianapolis, Indiana 46202, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Meade VM, Barese CN, Kim C, Njinimbam CG, Marchal CC, Ingram DA, Clapp DW, Dinauer MC, Yoder MC. Rac2 concentrations in umbilical cord neutrophils. Neonatology 2006; 90:156-9. [PMID: 16582540 DOI: 10.1159/000092451] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2005] [Accepted: 10/03/2005] [Indexed: 11/19/2022]
Abstract
BACKGROUND Human newborn infants display a variety of immunodeficiencies of immaturity, including diminished neutrophil adhesion, chemotaxis, and migration. Rac2, a guanosine triphosphate-binding protein, is an essential regulator of human neutrophil migration and chemotaxis. Since human subjects and mice deficient in Rac2 display deficiencies in neutrophil functions similar to newborn infants, we postulated that newborn neutrophils may be deficient in Rac2. OBJECTIVES The aim of the study was to measure Rac1 and Rac2 concentrations in neutrophils from umbilical cord blood. METHODS Neutrophils from cord and adult blood were isolated, total cell lysates extracted, and Rac protein concentrations determined using Western blot analysis. RESULTS Rac2 concentrations were significantly lower in the neutrophil protein lysates isolated from cord blood compared to adult blood despite similar levels of Rac1. CONCLUSIONS Diminished Rac2 expression in cord blood neutrophils may contribute to the defects observed in cord blood neutrophil function.
Collapse
Affiliation(s)
- Virginia M Meade
- Herman B. Wells Center for Pediatric Research, Department of Pediatrics, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Yamauchi A, Marchal CC, Molitoris J, Pech N, Knaus U, Towe J, Atkinson SJ, Dinauer MC. Rac GTPase isoform-specific regulation of NADPH oxidase and chemotaxis in murine neutrophils in vivo. Role of the C-terminal polybasic domain. J Biol Chem 2005; 280:953-64. [PMID: 15504745 DOI: 10.1074/jbc.m408820200] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Rho family GTPase Rac acts as a molecular switch for signal transduction to regulate various cellular functions. Mice deficient in the hematopoietic-specific Rac2 isoform exhibit agonist-specific defects in neutrophil chemotaxis and superoxide production, despite expression of the highly homologous Rac1 isoform. To examine whether functional defects in rac2(-/-) neutrophils reflect effects of an overall decrease in total cellular Rac or an isoform-specific role for Rac2, retroviral vectors were used to express exogenous Rac1 or Rac2 at levels similar to endogenous. In rac2(-/-) neutrophils differentiated from transduced myeloid progenitors in vitro, increasing cellular Rac levels by expression of either exogenous Rac1 or Rac2 increased formylmethionylleucylphenylalanine- or phorbol ester-stimulated NADPH oxidase activity. Of note, placement of an epitope tag on the N terminus of Rac1 or Rac2 blunted reconstitution of responses in rac2(-/-) neutrophils. In rac2(-/-) neutrophils isolated from mice transplanted with Rac-transduced bone marrow cells, superoxide production and chemotaxis were fully reconstituted by expression of exogenous Rac2, but not Rac1. A chimeric Rac1 protein in which the Rac1 C-terminal polybasic domain, which contains six lysines or arginines, was replaced with that of the human Rac2 polybasic domain containing only three basic residues, also reconstituted superoxide production and chemotaxis, whereas expression of a Rac2 derivative in which the polybasic domain was replaced with that of Rac1 did not and resulted in disoriented cell motility. Thus, the composition of the polybasic domain is sufficient for determining Rac isoform specificity in the production of superoxide and chemotaxis in murine neutrophils in vivo.
Collapse
Affiliation(s)
- Akira Yamauchi
- Herman B Wells Center for Pediatric Research, the Department of Pediatrics (Hematology/Oncology), James Whitcomb Riley Hospital for Children, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA
| | | | | | | | | | | | | | | |
Collapse
|
11
|
Yamauchi A, Kim C, Li S, Marchal CC, Towe J, Atkinson SJ, Dinauer MC. Rac2-deficient murine macrophages have selective defects in superoxide production and phagocytosis of opsonized particles. J Immunol 2004; 173:5971-9. [PMID: 15528331 DOI: 10.4049/jimmunol.173.10.5971] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The Rho family GTPase Rac is a crucial participant in numerous cellular functions and acts as a molecular switch for signal transduction. Mice deficient in hemopoietic-specific Rac2 exhibited agonist-specific defects in neutrophil functions including chemoattractant-stimulated filamentous actin polymerization and chemotaxis, and superoxide production elicited by phorbol ester, fMLP, or IgG-coated particles, despite expression of the highly homologous Rac1 isoform. In this study, functional responses of Rac2-null murine macrophages were characterized to examine whether Rac2 also has nonredundant functions in this phagocytic lineage. In contrast to murine neutrophils, in which Rac1 and Rac2 are present in similar amounts, Rac1 was approximately 4-fold more abundant than Rac2 in both bone marrow-derived and peritoneal exudate macrophages, and macrophage Rac1 levels were unchanged by the absence of Rac2. Accumulation of exudate macrophages during peritoneal inflammation was reduced in rac2(-/-) mice. FcgammaR-mediated phagocytosis of IgG-coated SRBC was also significantly decreased in Rac2-null macrophages, as was NADPH oxidase activity in response to phorbol ester or FcgammaR stimulation. However, phagocytosis and oxidant production stimulated by serum-opsonized zymosan was normal in rac2(-/-) macrophages. Macrophage morphology was also similar in wild-type and Rac2-null cells, as was actin polymerization induced by FcgammaR-mediated phagocytosis or M-CSF. Hence, Rac2-null macrophages have selective defects paralleling many of the observed functional defects in Rac2-null neutrophils. These results provide genetic evidence that although Rac2 is a relatively minor isoform in murine macrophages, it plays a nonoverlapping role with Rac1 to regulate host defense functions in this phagocyte lineage.
Collapse
|
12
|
Kim C, Marchal CC, Penninger J, Dinauer MC. The hemopoietic Rho/Rac guanine nucleotide exchange factor Vav1 regulates N-formyl-methionyl-leucyl-phenylalanine-activated neutrophil functions. J Immunol 2004; 171:4425-30. [PMID: 14530369 DOI: 10.4049/jimmunol.171.8.4425] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Vav1 is a hemopoietic-specific Rho/Rac guanine nucleotide exchange factor that plays a prominent role in responses to multisubunit immune recognition receptors in lymphoid cells, but its contribution to regulation of neutrophil functions is unknown. Activated Rho family GTPases are critical participants in neutrophil signaling cascades initiated by binding of FMLP and other chemoattractants to their cognate G protein-coupled receptors. Therefore, we investigated whether Vav1 regulates chemoattractant-induced responses in neutrophils. We found that superoxide production elicited by FMLP in Vav1(-/-) murine neutrophils isolated from either bone marrow or from peritoneal exudates was substantially reduced compared with that of wild type. Filamentous actin generation in FMLP-stimulated Vav1(-/-) neutrophils was also markedly reduced, whereas it was normal in response to IL-8 or leukotriene B(4). FMLP induced tyrosine phosphorylation of Vav1, whereas IL-8 or leukotriene B(4) did not, correlating with the requirement for Vav1 in chemoattractant-stimulated filamentous actin generation. Neutrophil motility in vitro and neutrophil mobilization into peripheral blood in vivo elicited by FMLP were both decreased in Vav1(-/-) mice. Hence, this study defines a new role for Vav1 in regulating granulocytic leukocytes as well as linking Vav1 to specific cellular responses downstream of a seven transmembrane domain receptor.
Collapse
Affiliation(s)
- Chaekyun Kim
- Herman B. Wells Center for Pediatric Research, Department of Pediatrics (Hematology/Oncology), James Whitcomb Riley Hospital for Children, Indiana University Medical Center, Indianapolis, IN 46202, USA
| | | | | | | |
Collapse
|
13
|
Glogauer M, Marchal CC, Zhu F, Worku A, Clausen BE, Foerster I, Marks P, Downey GP, Dinauer M, Kwiatkowski DJ. Rac1 deletion in mouse neutrophils has selective effects on neutrophil functions. J Immunol 2003; 170:5652-7. [PMID: 12759446 DOI: 10.4049/jimmunol.170.11.5652] [Citation(s) in RCA: 250] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Defects in myeloid cell function in Rac2 knockout mice underline the importance of this isoform in activation of NADPH oxidase and cell motility. However, the specific role of Rac1 in neutrophil function has been difficult to assess since deletion of Rac1 results in embryonic lethality in mice. To elucidate the specific role of Rac1 in neutrophils, we generated mice with a conditional Rac1 deficiency restricted to cells of the granulocyte/monocyte lineage. As observed in Rac2-deficient neutrophils, Rac1-deficient neutrophils demonstrated profound defects in inflammatory recruitment in vivo, migration to chemotactic stimuli, and chemoattractant-mediated actin assembly. In contrast, superoxide production is normal in Rac1-deficient neutrophils but markedly diminished in Rac2 null cells. These data demonstrate that although Rac1 and Rac2 are both required for actin-mediated functions, Rac2 is specifically required for activation of the neutrophil NADPH oxidase.
Collapse
|
14
|
Li S, Yamauchi A, Marchal CC, Molitoris JK, Quilliam LA, Dinauer MC. Chemoattractant-stimulated Rac activation in wild-type and Rac2-deficient murine neutrophils: preferential activation of Rac2 and Rac2 gene dosage effect on neutrophil functions. J Immunol 2002; 169:5043-51. [PMID: 12391220 DOI: 10.4049/jimmunol.169.9.5043] [Citation(s) in RCA: 110] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The hemopoietic-specific Rho family GTPase Rac2 shares 92% amino acid identity with ubiquitously expressed Rac1. Neutrophils from rac2(-/-) mice have multiple defects, including chemoattractant-stimulated NADPH oxidase activity and chemotaxis, which may result from an overall reduction in cellular Rac or mechanisms that discriminate Rac1 and Rac2. We show that murine neutrophils have similar amounts of Rac1 and Rac2, unlike human neutrophils, which express predominantly Rac2. An affinity precipitation assay for Rac-GTP showed that although FMLP-induced activation of both isoforms in wild-type neutrophils, approximately 4-fold more Rac2-GTP was detected than Rac1-GTP. Wild-type and Rac2-deficient neutrophils have similar levels of total Rac1. FMLP-induced Rac1-GTP in rac2(-/-) neutrophils was approximately 3-fold greater than in wild-type cells, which have similar levels of total Rac1, yet FMLP-stimulated F-actin, chemotaxis, and superoxide production are markedly impaired in rac2(-/-) neutrophils. Heterozygous rac2(+/-) neutrophils, which had intermediate levels of total and FMLP-induced activated Rac2, exhibited intermediate functional responses to FMLP, suggesting that Rac2 was rate limiting for these functions. Thus, phenotypic defects in FMLP-stimulated Rac2-deficient neutrophils appear to reflect distinct activation and signaling profiles of Rac1 and Rac2, rather than a reduction in the total cellular level of Rac.
Collapse
Affiliation(s)
- Shijun Li
- Herman B Wells Center for Pediatric Research and Department of Pediatrics (Hematology/Oncology), Indiana University Medical School, Indianapolis 46202, USA
| | | | | | | | | | | |
Collapse
|