1
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Hall JS, Hofmeister E, Ip HS, Nashold SW, Leon AE, Malavé CM, Falendysz EA, Rocke TE, Carossino M, Balasuriya U, Knowles S. Experimental infection of Mexican free-tailed bats ( Tadarida brasiliensis) with SARS-CoV-2. bioRxiv 2022:2022.07.18.500430. [PMID: 35898345 PMCID: PMC9327625 DOI: 10.1101/2022.07.18.500430] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) virus originated in wild bats from Asia, and as the resulting pandemic continues into its third year, concerns have been raised that the virus will expand its host range and infect North American wildlife species, including bats. Mexican free-tailed bats ( Tadarida brasiliensis : TABR) live in large colonies in the southern United States, often in urban areas, and as such, could be exposed to the virus from infected humans. We experimentally challenged wild TABR with SARS-CoV-2 to determine the susceptibility, reservoir potential, and population impacts of infection in this species. Of nine bats oronasally inoculated with SARS-CoV-2, five became infected and orally excreted moderate amounts of virus for up to 18 days post inoculation. These five subjects all seroconverted and cleared the virus before the end of the study with no obvious clinical signs of disease. We additionally found no evidence of viral transmission to uninoculated subjects. These results indicate that while TABR are susceptible to SARS-CoV-2 infection, infection of wild populations of TABR would not likely cause mortality. However, the transmission of SARS-CoV-2 from TABR to or from humans, or to other animal species, is a distinct possibility requiring further investigation to better define.
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Affiliation(s)
- JS Hall
- U.S. Geological Survey, National Wildlife Health Center, Madison, Wisconsin,Corresponding author
| | - E Hofmeister
- U.S. Geological Survey, National Wildlife Health Center, Madison, Wisconsin
| | - HS Ip
- U.S. Geological Survey, National Wildlife Health Center, Madison, Wisconsin
| | - SW Nashold
- U.S. Geological Survey, National Wildlife Health Center, Madison, Wisconsin
| | - AE Leon
- U.S. Geological Survey, National Wildlife Health Center, Madison, Wisconsin
| | - CM Malavé
- U.S. Geological Survey, National Wildlife Health Center, Madison, Wisconsin
| | - EA Falendysz
- U.S. Geological Survey, National Wildlife Health Center, Madison, Wisconsin
| | - TE Rocke
- U.S. Geological Survey, National Wildlife Health Center, Madison, Wisconsin
| | - M Carossino
- Louisiana Animal Disease Diagnostic Laboratory and Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana
| | - U Balasuriya
- Louisiana Animal Disease Diagnostic Laboratory and Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana
| | - S Knowles
- U.S. Geological Survey, National Wildlife Health Center, Madison, Wisconsin
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2
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Loy J, Ip H, Thompson R. The Australian equine industry. J Vet Behav 2019. [DOI: 10.1016/j.jveb.2018.06.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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3
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Isidoro-Ayza M, Afonso CL, Stanton JB, Knowles S, Ip HS, White CL, Fenton H, Ruder MG, Dolinski AC, Lankton J. Natural Infections With Pigeon Paramyxovirus Serotype 1: Pathologic Changes in Eurasian Collared-Doves ( Streptopelia decaocto) and Rock Pigeons ( Columba livia) in the United States. Vet Pathol 2017; 54:695-703. [PMID: 28382855 DOI: 10.1177/0300985817695782] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Pigeon paramyxovirus serotype 1 (PPMV-1) is a globally distributed, virulent member of the avian paramyxovirus serotype 1 serogroup that causes mortality in columbiformes and poultry. Following introduction into the United States in the mid-1980s, PPMV-1 rapidly spread causing numerous mortality events in Eurasian collared-doves ( Streptopelia decaocto) (ECDOs) and rock pigeons ( Columba livia) (ROPIs). The investigators reviewed pathological findings of 70 naturally infected, free-ranging columbiforms from 25 different mortality events in the United States. Immunohistochemistry targeting PPMV-1 nucleoprotein was used to determine the tissue distribution of the virus in a subset of 17 birds from 10 of the studied outbreaks. ECDOs (61 birds) and ROPIs (9 birds) were the only species in which PPMV-1-associated disease was confirmed by viral isolation and presence of histologic lesions. Acute to subacute tubulointerstitial nephritis and necrotizing pancreatitis were the most frequent histologic lesions, with immunolabeling of viral antigen in renal tubular epithelial cells and pancreatic acinar epithelium. Lymphoid depletion of bursa of Fabricius and spleen was common, but the presence of viral antigen in these organs was inconsistent among infected birds. Hepatocellular necrosis was occasionally present with immunolabeling of hypertrophic Kupffer cells, and immunopositive eosinophilic intracytoplasmic inclusion bodies were present in hepatocytes of 1 ECDO. Immunopositive lymphocytic choroiditis was present in 1 ECDO, while lymphocytic meningoencephalitis was frequent in ROPIs in absence of immunolabeling. This study demonstrates widespread presence of PPMV-1 antigen in association with histologic lesions, confirming the lethal potential of this virus in these particular bird species.
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Affiliation(s)
- M Isidoro-Ayza
- 1 Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI, USA
| | - C L Afonso
- 2 Southeast Poultry Research Laboratory, Agricultural Research Service, US Department of Agriculture, Athens, GA, USA
| | - J B Stanton
- 3 Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, GA, USA
| | - S Knowles
- 4 National Wildlife Health Center-US Geological Survey, Madison, WI, USA
| | - H S Ip
- 4 National Wildlife Health Center-US Geological Survey, Madison, WI, USA
| | - C L White
- 4 National Wildlife Health Center-US Geological Survey, Madison, WI, USA
| | - H Fenton
- 5 Southeastern Cooperative Wildlife Disease Study, Athens, GA, USA
| | - M G Ruder
- 5 Southeastern Cooperative Wildlife Disease Study, Athens, GA, USA
| | - A C Dolinski
- 6 Department of Fisheries and Wildlife, Michigan State University, East Lansing, MI, USA
| | - J Lankton
- 4 National Wildlife Health Center-US Geological Survey, Madison, WI, USA
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4
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Wilson CS, Brookes VJ, Hughes KJ, Trope GD, Ip H, Gunn AJ. Oesophageal lumen pH in yearling horses and effects of management and administration of omeprazole. Equine Vet J 2016; 49:389-394. [DOI: 10.1111/evj.12608] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 07/01/2016] [Indexed: 11/30/2022]
Affiliation(s)
- C. S. Wilson
- School of Animal and Veterinary Sciences; Faculty of Science; Charles Sturt University; Wagga Wagga New South Wales Australia
| | - V. J. Brookes
- School of Animal and Veterinary Sciences; Faculty of Science; Charles Sturt University; Wagga Wagga New South Wales Australia
- Graham Centre for Agricultural Innovation; Wagga Wagga New South Wales Australia
| | - K. J. Hughes
- School of Animal and Veterinary Sciences; Faculty of Science; Charles Sturt University; Wagga Wagga New South Wales Australia
| | - G. D. Trope
- School of Animal and Veterinary Sciences; Faculty of Science; Charles Sturt University; Wagga Wagga New South Wales Australia
| | - H. Ip
- School of Animal and Veterinary Sciences; Faculty of Science; Charles Sturt University; Wagga Wagga New South Wales Australia
| | - A. J. Gunn
- School of Animal and Veterinary Sciences; Faculty of Science; Charles Sturt University; Wagga Wagga New South Wales Australia
- Graham Centre for Agricultural Innovation; Wagga Wagga New South Wales Australia
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Bevins SN, Dusek RJ, White CL, Gidlewski T, Bodenstein B, Mansfield KG, DeBruyn P, Kraege D, Rowan E, Gillin C, Thomas B, Chandler S, Baroch J, Schmit B, Grady MJ, Miller RS, Drew ML, Stopak S, Zscheile B, Bennett J, Sengl J, Brady C, Ip HS, Spackman E, Killian ML, Torchetti MK, Sleeman JM, Deliberto TJ. Widespread detection of highly pathogenic H5 influenza viruses in wild birds from the Pacific Flyway of the United States. Sci Rep 2016; 6:28980. [PMID: 27381241 PMCID: PMC4933915 DOI: 10.1038/srep28980] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [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: 01/14/2016] [Accepted: 06/08/2016] [Indexed: 01/21/2023] Open
Abstract
A novel highly pathogenic avian influenza virus belonging to the H5 clade 2.3.4.4 variant viruses was detected in North America in late 2014. Motivated by the identification of these viruses in domestic poultry in Canada, an intensive study was initiated to conduct highly pathogenic avian influenza surveillance in wild birds in the Pacific Flyway of the United States. A total of 4,729 hunter-harvested wild birds were sampled and highly pathogenic avian influenza virus was detected in 1.3% (n = 63). Three H5 clade 2.3.4.4 subtypes were isolated from wild birds, H5N2, H5N8, and H5N1, representing the wholly Eurasian lineage H5N8 and two novel reassortant viruses. Testing of 150 additional wild birds during avian morbidity and mortality investigations in Washington yielded 10 (6.7%) additional highly pathogenic avian influenza isolates (H5N8 = 3 and H5N2 = 7). The geographically widespread detection of these viruses in apparently healthy wild waterfowl suggest that the H5 clade 2.3.4.4 variant viruses may behave similarly in this taxonomic group whereby many waterfowl species are susceptible to infection but do not demonstrate obvious clinical disease. Despite these findings in wild waterfowl, mortality has been documented for some wild bird species and losses in US domestic poultry during the first half of 2015 were unprecedented.
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Affiliation(s)
- S N Bevins
- US Department of Agriculture-National Wildlife Research Center, Fort Collins, Colorado, USA
| | - R J Dusek
- US Geological Survey-National Wildlife Health Center, Madison, Wisconsin, USA
| | - C L White
- US Geological Survey-National Wildlife Health Center, Madison, Wisconsin, USA
| | - T Gidlewski
- US Department of Agriculture-National Wildlife Research Center, Fort Collins, Colorado, USA
| | - B Bodenstein
- US Geological Survey-National Wildlife Health Center, Madison, Wisconsin, USA
| | - K G Mansfield
- Washington Department of Fish and Wildlife, Olympia, Washington, USA
| | - P DeBruyn
- Washington Department of Fish and Wildlife, Olympia, Washington, USA
| | - D Kraege
- Washington Department of Fish and Wildlife, Olympia, Washington, USA
| | - E Rowan
- Washington Department of Fish and Wildlife, Olympia, Washington, USA
| | - C Gillin
- Oregon Department of Fish and Wildlife, Corvallis, Oregon, USA
| | - B Thomas
- USDA Wildlife Services, Salem, Oregon, USA
| | - S Chandler
- USDA Wildlife Services, Sacramento, California, USA
| | - J Baroch
- US Department of Agriculture-National Wildlife Research Center, Fort Collins, Colorado, USA
| | - B Schmit
- US Department of Agriculture-National Wildlife Research Center, Fort Collins, Colorado, USA
| | - M J Grady
- US Department of Agriculture-National Wildlife Research Center, Fort Collins, Colorado, USA
| | - R S Miller
- USDA Veterinary Services, Fort Collins, Colorado, USA
| | - M L Drew
- Idaho Department of Fish and Game, Caldwell, Idaho, USA
| | - S Stopak
- USDA Wildlife Services, Boise, Idaho, USA
| | - B Zscheile
- USDA Wildlife Services, Salt Lake City, Utah, USA
| | - J Bennett
- USDA Wildlife Services, Reno, Nevada, USA
| | - J Sengl
- USDA Wildlife Services, Reno, Nevada, USA
| | - Caroline Brady
- California Waterfowl Association, Roseville, California, USA
| | - H S Ip
- US Geological Survey-National Wildlife Health Center, Madison, Wisconsin, USA
| | - E Spackman
- USDA ARS Southeast Poultry Research Laboratory, Athens, Georgia, USA
| | - M L Killian
- US Department of Agriculture, Ames, Iowa, USA
| | | | - J M Sleeman
- US Geological Survey-National Wildlife Health Center, Madison, Wisconsin, USA
| | - T J Deliberto
- US Department of Agriculture-National Wildlife Research Center, Fort Collins, Colorado, USA
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6
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Ip H, Hyder SMZ, Haseen F, Rahman M, Zlotkin SH. Improved adherence and anaemia cure rates with flexible administration of micronutrient Sprinkles: a new public health approach to anaemia control. Eur J Clin Nutr 2007; 63:165-72. [PMID: 17895911 DOI: 10.1038/sj.ejcn.1602917] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [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: 11/09/2022]
Abstract
BACKGROUND/OBJECTIVES Despite repeated public commitments and availability of various forms of iron supplements, rates of anaemia in developing countries remain high. A major reason for this lack of success has been poor adherence. The objective of this study was to compare the effectiveness of daily and flexible administration of micronutrient Sprinkles on adherence, acceptability and haematological status among young children in rural Bangladesh. SUBJECTS/METHODS A sample of 362 children (haemoglobin (Hb)>or=70 g l(-1)) aged 6-24 months were cluster-randomized to receive 60 sachets of Sprinkles either (i) daily over 2 months; (ii) flexibly over 3 months; or (iii) flexibly over 4 months. With a flexible regimen, mothers/caregivers decided how frequently to use Sprinkles without exceeding one sachet per day. Adherence was assessed monthly by counting the number of sachets used and acceptability was evaluated through focus group discussions. Haemoglobin was measured at baseline, at the end of each intervention period and 6 months post-intervention. RESULTS Mean percent adherence was significantly higher in the flexible-4-month group (98%) compared to the flexible-3-month (93%) and daily-2-month (88%) groups (P<0.01). Most mothers found flexible administration to be more acceptable than daily due to perceived benefits of use. Hb at the end of intervention was significantly higher in the flexible-4-month group compared to the daily group (P=0.03). Anaemia prevalence decreased by 65% in the flexible-4-month group compared to 54% in the flexible-3-month and 51% in the daily-2-month groups. Percent of cured children who maintained a non-anaemic status 6 months post-intervention was significantly higher in the flexible-4-month (82%) and flexible-3-month (80%) groups than the daily-2-month (53%) group (P<0.05). CONCLUSIONS The adherence, acceptability and haematological response to flexible administration over 4 months were found preferable to daily.
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Affiliation(s)
- H Ip
- Department of Nutritional Sciences, University of Toronto and Program in Metabolism and Integrated Biology, Research Institute, The Hospital for Sick Children, Toronto, Canada
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7
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Tiwari A, Wong M, Ip H. Ren and Yuan: a cultural interpretation of Chinese women's responses to battering. Can J Nurs Res 2001; 33:63-79. [PMID: 11845624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
The purpose of the study was to examine women's responses to battering within the context of Chinese culture. The stories of 11 Chinese women living in Hong Kong formed the basis of the inquiry. Analysis of the women's accounts revealed Chinese values in their responses to battering: they adopted ren, or endurance, as a coping mechanism and used Yuan, or predestination, as an explanation for their failed relationship. The resilience and resourcefulness of the women are clearly demonstrated in the strategies they employed to cope with the abuse. Their responses to battering were purposeful and varied according to the status of their relationship.
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Affiliation(s)
- A Tiwari
- Department of Nursing Studies, University of Hong Kong, Hong Kong.
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Ip H, D'Aoust F, Begum AA, Zhang H, Smith DL, Driscoll BT, Charles TC. Bradyrhizobium japonicum mutants with enhanced sensitivity to genistein resulting in altered nod gene regulation. Mol Plant Microbe Interact 2001; 14:1404-1410. [PMID: 11768535 DOI: 10.1094/mpmi.2001.14.12.1404] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Bradyrhizobium japonicum mutants with altered nod gene induction characteristics were isolated by screening mutants for genistein-independent nod gene expression. Plasmid pZB32, carrying a nodY::lacZ transcriptional gene fusion, was introduced into B. japonicum cells that had been subjected to UV mutagenesis. Ten independent transformants producing a blue color on plates containing 5bromo-4chloro-3indolyl-beta-D-galactopyranoside but lacking genistein, indicative of constitutive expression of the nodY::lacZ reporter gene, were isolated. Beta-galactosidase activity assays revealed that while all of the 10 strains were sensitive to low concentrations of genistein, none exhibited truly constitutive nodY::lacZ expression in liquid culture. Soybean plants inoculated with three of the mutants were chlorotic and stunted, with shoot dry weights close to those of the uninoculated plants, indicating the absence of nitrogen fixation. Differences in the kinetics of nodY::lacZ expression and lipochitin oligosaccharide Nod signal production suggested that the strains carried different mutations. Some of these strains may be useful in mitigating the low root zone temperature-associated delay in soybean nodulation at the northern extent of soybean cultivation.
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Affiliation(s)
- H Ip
- Department of Biology, University of Waterloo, Ontario, Canada
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Eis PS, Olson MC, Takova T, Curtis ML, Olson SM, Vener TI, Ip HS, Vedvik KL, Bartholomay CT, Allawi HT, Ma WP, Hall JG, Morin MD, Rushmore TH, Lyamichev VI, Kwiatkowski RW. An invasive cleavage assay for direct quantitation of specific RNAs. Nat Biotechnol 2001; 19:673-6. [PMID: 11433281 DOI: 10.1038/90290] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [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: 11/08/2022]
Abstract
RNA quantitation is becoming increasingly important in basic, pharmaceutical, and clinical research. For example, quantitation of viral RNAs can predict disease progression and therapeutic efficacy. Likewise, gene expression analysis of diseased versus normal, or untreated versus treated, tissue can identify relevant biological responses or assess the effects of pharmacological agents. As the focus of the Human Genome Project moves toward gene expression analysis, the field will require a flexible RNA analysis technology that can quantitatively monitor multiple forms of alternatively transcribed and/or processed RNAs (refs 3,4). We have applied the principles of invasive cleavage and engineered an improved 5'-nuclease to develop an isothermal, fluorescence resonance energy transfer (FRET)-based signal amplification method for detecting RNA in both total RNA and cell lysate samples. This detection format, termed the RNA invasive cleavage assay, obviates the need for target amplification or additional enzymatic signal enhancement. In this report, we describe the assay and present data demonstrating its capabilities for sensitive (<100 copies per reaction), specific (discrimination of 95% homologous sequences, 1 in > or =20,000), and quantitative (1.2-fold changes in RNA levels) detection of unamplified RNA in both single- and biplex-reaction formats.
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Affiliation(s)
- P S Eis
- Third Wave Technologies, 502 South Rosa Road, Madison, WI 53719-1256, USA.
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Allawi HT, Dong F, Ip HS, Neri BP, Lyamichev VI. Mapping of RNA accessible sites by extension of random oligonucleotide libraries with reverse transcriptase. RNA 2001; 7:314-327. [PMID: 11233988 PMCID: PMC1370089 DOI: 10.1017/s1355838201001698] [Citation(s) in RCA: 30] [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] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A rapid and simple method for determining accessible sites in RNA that is independent of the length of target RNA and does not require RNA labeling is described. In this method, target RNA is allowed to hybridize with sequence-randomized libraries of DNA oligonucleotides linked to a common tag sequence at their 5'-end. Annealed oligonucleotides are extended with reverse transcriptase and the extended products are then amplified by using PCR with a primer corresponding to the tag sequence and a second primer specific to the target RNA sequence. We used the combination of both the lengths of the RT-PCR products and the location of the binding site of the RNA-specific primer to determine which regions of the RNA molecules were RNA extendible sites, that is, sites available for oligonucleotide binding and extension. We then employed this reverse transcription with the random oligonucleotide libraries (RT-ROL) method to determine the accessible sites on four mRNA targets, human activated ras (ha-ras), human intercellular adhesion molecule-1 (ICAM-1), rabbit beta-globin, and human interferon-gamma (IFN-gamma). Our results were concordant with those of other researchers who had used RNase H cleavage or hybridization with arrays of oligonucleotides to identify accessible sites on some of these targets. Further, we found good correlation between sites when we compared the location of extendible sites identified by RT-ROL with hybridization sites of effective antisense oligonucleotides on ICAM-1 mRNA in antisense inhibition studies. Finally, we discuss the relationship between RNA extendible sites and RNA accessibility.
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Affiliation(s)
- H T Allawi
- Third Wave Technologies, Inc., Madison, Wisconsin 53719, USA
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11
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Morrisey EE, Tang Z, Sigrist K, Lu MM, Jiang F, Ip HS, Parmacek MS. GATA6 regulates HNF4 and is required for differentiation of visceral endoderm in the mouse embryo. Genes Dev 1998; 12:3579-90. [PMID: 9832509 PMCID: PMC317242 DOI: 10.1101/gad.12.22.3579] [Citation(s) in RCA: 538] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
GATA6 belongs to a family of zinc finger transcription factors that play important roles in transducing nuclear events that regulate cellular differentiation and embryonic morphogenesis in vertebrate species. To examine the function of GATA6 during embryonic development, gene targeting was used to generate GATA6-deficient (GATA6(-/-)) ES cells and mice harboring a null mutation in GATA6. Differentiated embryoid bodies derived from GATA6(-/-) ES cells lack a covering layer of visceral endoderm and severely attenuate, or fail to express, genes encoding early and late endodermal markers, including HNF4, GATA4, alpha-fetoprotein (AFP), and HNF3beta. Homozygous GATA6(-/-) mice died between embryonic day (E) 6.5 and E7. 5 and exhibited a specific defect in endoderm differentiation including severely down-regulated expression of GATA4 and absence of HNF4 gene expression. Moreover, widespread programmed cell death was observed within the embryonic ectoderm of GATA6-deficient embryos, a finding also observed in HNF4-deficient embryos. Consistent with these data, forced expression of GATA6 activated the HNF4 promoter in nonendodermal cells. Finally, to examine the function of GATA6 during later embryonic development, GATA6(-/-)-C57BL/6 chimeric mice were generated. lacZ-tagged GATA6(-/-) ES cells contributed to all embryonic tissues with the exception of the endodermally derived bronchial epithelium. Taken together, these data suggest a model in which GATA6 lies upstream of HNF4 in a transcriptional cascade that regulates differentiation of the visceral endoderm. In addition, these data demonstrate that GATA6 is required for establishment of the endodermally derived bronchial epithelium.
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Affiliation(s)
- E E Morrisey
- Department of Medicine, University of Chicago, Chicago, Illinois 60637 USA
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12
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Kim S, Ip HS, Lu MM, Clendenin C, Parmacek MS. A serum response factor-dependent transcriptional regulatory program identifies distinct smooth muscle cell sublineages. Mol Cell Biol 1997; 17:2266-78. [PMID: 9121477 PMCID: PMC232076 DOI: 10.1128/mcb.17.4.2266] [Citation(s) in RCA: 184] [Impact Index Per Article: 6.8] [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: 02/04/2023] Open
Abstract
The SM22alpha promoter has been used as a model system to define the molecular mechanisms that regulate smooth muscle cell (SMC) specific gene expression during mammalian development. The SM22alpha gene is expressed exclusively in vascular and visceral SMCs during postnatal development and is transiently expressed in the heart and somites during embryogenesis. Analysis of the SM22alpha promoter in transgenic mice revealed that 280 bp of 5' flanking sequence is sufficient to restrict expression of the lacZ reporter gene to arterial SMCs and the myotomal component of the somites. DNase I footprint and electrophoretic mobility shift analyses revealed that the SM22alpha promoter contains six nuclear protein binding sites (designated smooth muscle elements [SMEs] -1 to -6, respectively), two of which bind serum response factor (SRF) (SME-1 and SME-4). Mutational analyses demonstrated that a two-nucleotide substitution that selectively eliminates SRF binding to SME-4 decreases SM22alpha promoter activity in arterial SMCs by approximately 90%. Moreover, mutations that abolish binding of SRF to SME-1 and SME-4 or mutations that eliminate each SME-3 binding activity totally abolished SM22alpha promoter activity in the arterial SMCs and somites of transgenic mice. Finally, we have shown that a multimerized copy of SME-4 (bp -190 to -110) when linked to the minimal SM22alpha promoter (bp -90 to +41) is necessary and sufficient to direct high-level transcription in an SMC lineage-restricted fashion. Taken together, these data demonstrate that distinct transcriptional regulatory programs control SM22alpha gene expression in arterial versus visceral SMCs. Moreover, these data are consistent with a model in which combinatorial interactions between SRF and other transcription factors that bind to SME-4 (and that bind directly to SRF) activate transcription of the SM22alpha gene in arterial SMCs.
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MESH Headings
- Animals
- Base Sequence
- Binding Sites/genetics
- Cells, Cultured
- DNA/genetics
- DNA/metabolism
- DNA-Binding Proteins/metabolism
- Gene Expression Regulation, Developmental
- Genes, Reporter
- Lac Operon
- Mice
- Mice, Transgenic
- Microfilament Proteins
- Molecular Sequence Data
- Muscle Development
- Muscle Proteins/genetics
- Muscle, Smooth/cytology
- Muscle, Smooth/growth & development
- Muscle, Smooth/metabolism
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/growth & development
- Muscle, Smooth, Vascular/metabolism
- Mutation
- Nuclear Proteins/metabolism
- Promoter Regions, Genetic
- Rats
- Serum Response Factor
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Affiliation(s)
- S Kim
- Department of Medicine, University of Chicago, Illinois 60637, USA
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13
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Morrisey EE, Ip HS, Tang Z, Parmacek MS. GATA-4 activates transcription via two novel domains that are conserved within the GATA-4/5/6 subfamily. J Biol Chem 1997; 272:8515-24. [PMID: 9079680 DOI: 10.1074/jbc.272.13.8515] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.0] [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] [Indexed: 02/04/2023] Open
Abstract
GATA-4 is one of the earliest developmental markers of the precardiac mesoderm, heart, and gut and has been shown to activate regulatory elements controlling transcription of genes encoding cardiac-specific proteins. To elucidate the molecular mechanisms underlying the transcriptional activity of the GATA-4 protein, structure-function analyses were performed. These analyses revealed that the C-terminal zinc finger and adjacent basic domain of GATA-4 is bifunctional, modulating both DNA-binding and nuclear localization activities. The N terminus of the protein encodes two independent transcriptional Activation Domains (amino acids 1-74 and amino acids 130-177). Amino acid residues were identified within each domain that are required for transcriptional activation. Finally, we have shown that regions of Xenopus GATA-5 and -6 corresponding to Activation Domains I and II, respectively, function as potent transcriptional activators. The identification and functional characterization of two evolutionarily conserved transcriptional Activation Domains within the GATA-4/5/6 subfamily suggests that each of these domains modulates critical functions in the transcriptional regulatory program(s) encoded by GATA-4, -5, and -6 during vertebrate development. As such these data provide novel insights into the molecular mechanisms that control development of the heart.
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Affiliation(s)
- E E Morrisey
- Department of Medicine, University of Chicago, Chicago, Illinois 60637, USA
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Morrisey EE, Ip HS, Tang Z, Lu MM, Parmacek MS. GATA-5: a transcriptional activator expressed in a novel temporally and spatially-restricted pattern during embryonic development. Dev Biol 1997; 183:21-36. [PMID: 9119112 DOI: 10.1006/dbio.1996.8485] [Citation(s) in RCA: 188] [Impact Index Per Article: 7.0] [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] [Indexed: 02/04/2023]
Abstract
Members of the GATA family of zinc finger transcription factors regulate critical steps of cellular differentiation during vertebrate development. In the studies described in this report, we have isolated and functionally characterized the murine GATA-5 cDNA and protein and defined the temporal and spatial pattern of GATA-5 gene expression during mammalian development. The amino terminus of the mouse GATA-5 protein shares high level amino acid sequence identity with the murine GATA-4 and -6 proteins, but not with other members of the GATA family. GATA-5 binds to the functionally important CEF-1 nuclear protein binding site in the cardiac-specific slow/cardiac troponin C (cTnC) transcriptional enhancer and overexpression of GATA-5 transactivates the cTnC enhancer in noncardiac muscle cell lines. During embryonic and postnatal development, the pattern of GATA-5 gene expression differs significantly from that of other GATA family members. In the primitive streak embryo, GATA-5 mRNA is detectable in the precardiac mesoderm. Within the embryonic heart, the GATA-5 gene is expressed within the atrial and ventricular chambers (ED 9.5), becomes restricted to the atrial endocardium (ED 12.5), and is subsequently not expressed in the heart during late fetal and postnatal development. Moreover, coincident with the earliest steps in lung development, only the GATA-5 gene is expressed within the pulmonary mesenchyme. Finally, the GATA-5 gene is expressed in tissue-restricted subsets of smooth muscle cells (SMCs), including bronchial SMCs and SMCs in the bladder wall. These data are consistent with a model in which GATA-5 performs a unique temporally and spatially restricted function in the embryonic heart and lung. Moreover, these data suggest that GATA-5 may play an important role in the transcriptional program(s) that underlies smooth muscle cell diversity.
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Affiliation(s)
- E E Morrisey
- Department of Medicine, University of Chicago, Illinois 60637, USA
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15
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Thirman MJ, Diskin EB, Bin SS, Ip HS, Miller JM, Simon MC. Developmental analysis and subcellular localization of the murine homologue of ELL. Proc Natl Acad Sci U S A 1997; 94:1408-13. [PMID: 9037066 PMCID: PMC19804 DOI: 10.1073/pnas.94.4.1408] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [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: 02/03/2023] Open
Abstract
The ELL gene was first identified by its involvement with MLL in the translocation (11;19)(q23;p13.1) in acute myeloid leukemia. To date, nine other MLL partner genes have been cloned, but their precise functions have yet to be determined. To characterize the functions of ELL further, we have cloned the murine homologue of ELL and have found that the gene is highly conserved at the nucleotide and amino acid level. The open reading frame of the murine homologue contains 602 aa, slightly smaller than the 621 aa in the human gene. With Northern blot analysis, a 3.4-kb transcript is detected in all tissues examined with greatest levels of expression in the liver. Unlike human ELL, only a single transcript can be detected with either murine coding sequence or 3' untranslated region probes. To examine the spatial and temporal pattern of expression in murine development, in situ hybridization studies were performed with sense and antisense riboprobes from the 3' untranslated region of murine Ell. Ell is expressed diffusely by embryonic day 7.5 (E7.5). In addition, high levels of expression can be detected in maternally derived decidual tissue. At E14.5, Ell is expressed diffusely throughout the embryo. However by E16.5, specific expression in the liver and gastrointestinal tract becomes prominent and remains so in both neonates and adults. To determine the subcellular localization of ELL, we developed a polyclonal antiserum to ELL that was used for immunofluorescence studies in COS-7, HeLa, NIH 3T3, and A7r5 cells. The ELL protein was localized to the nucleus but excluded from nucleoli in all cell lines examined. Recently, the gene product of ELL was found to function as an RNA polymerase II elongation factor, an activity that is consistent with our immunofluorescence data. Thus, these studies extend our understanding of the normal functions of ELL and provide additional insight into its aberrant function when fused to MLL in acute myeloid leukemia.
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Affiliation(s)
- M J Thirman
- Department of Medicine, University of Chicago, IL 60637, USA
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16
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Morrisey EE, Ip HS, Lu MM, Parmacek MS. GATA-6: a zinc finger transcription factor that is expressed in multiple cell lineages derived from lateral mesoderm. Dev Biol 1996; 177:309-22. [PMID: 8660897 DOI: 10.1006/dbio.1996.0165] [Citation(s) in RCA: 374] [Impact Index Per Article: 13.4] [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: 02/01/2023]
Abstract
Members of the GATA family of zinc finger transcription factors play important roles in the development of several mesodermally derived cell lineages. In the studies described in this report, we have isolated and functionally characterized the murine GATA-6 cDNA and protein and defined the temporal and spatial patterns of GATA-6 gene expression during mammalian development. The GATA-6 and -4 proteins share high-level amino acid sequence identity over a proline-rich region at the amino terminus of the protein that is not conserved in other GATA family members. GATA-6 binds to a functionally important nuclear protein binding site within the cardiac-specific cardiac troponin C (cTnC) transcriptional enhancer. Moreover, the cTnC promoter enhancer can be transactivated by overexpression of GATA-6 in noncardiac muscle cells. During early murine embryonic development, the patterns of GATA-6 and -4 gene expression are similar, with expression of GATA-6 restricted to the precardiac mesoderm, the embryonic heart tube, and the primitive gut. However, coincident with the onset of vasculogenesis and development of the respiratory and urogenital tracts, only the GATA-6 gene is expressed in arterial smooth muscle cells, the developing bronchi, and the urogenital ridge and bladder. These data are consistent with a model in which GATA-6 functions in concert with GATA-4 to direct tissue-specific gene expression during formation of the mammalian heart and gastrointestinal tract, but performs a unique function in programming lineage-restricted gene expression in the arterial system, the bladder, and the embryonic lung.
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Affiliation(s)
- E E Morrisey
- Department of Medicine, University of Chicago, Chicago, Illinois, 60637, USA
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17
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Abstract
Spi-B and PU.1 are hematopoietic-specific transcription factors that constitute a subfamily of the Ets family of DNA-binding proteins. Here we show that contrary to previous reports, PU.1 and Spi-B have very different expression patterns. PU.1 is expressed at high levels in B cells, mast cells, megakaryocytes, macrophages, neutrophils, and immature erythroid cells and at lower levels in mature erythrocytes. PU.1 is completely absent from peripheral T cells and most T cell lines based on sensitive RT-PCR assays. In contrast, Spi-B is expressed exclusively in lymphoid cells and can be detected in early fetal thymus and spleen. In situ hybridizations of adult murine tissues demonstrate Spi-B mRNA in the medulla of the thymus, the white pulp of the spleen, and the germinal centers of lymph nodes. Spi-B expression is very abundant in B cells and both Spi-B mRNA and protein are detected in some T cells. In situ hybridization and Northern blot analysis suggest that Spi-B gene expression increases during B cell maturation and decreases during T cell maturation. Gel-retardation experiments show that Spi-B can bind to all putative PU.1 binding sites, but do not reveal any preferred Spi-B binding site. Finally, both PU.1 and Spi-B function as transcriptional activators of the immunoglobulin light-chain enhancer E lambda 2.4 when coexpressed with Pip (PU.1-interaction partner) in NIH-3T3 cells. Taken together, these data suggest that differences in patterns of expression between Spi-B and PU.1 distinguish the function of each protein during development of the immune system.
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Affiliation(s)
- G H Su
- Department of Medicine, University of Chicago, Illinois 60637, USA
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18
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Samaha FF, Ip HS, Morrisey EE, Seltzer J, Tang Z, Solway J, Parmacek MS. Developmental pattern of expression and genomic organization of the calponin-h1 gene. A contractile smooth muscle cell marker. J Biol Chem 1996; 271:395-403. [PMID: 8550594 DOI: 10.1074/jbc.271.1.395] [Citation(s) in RCA: 85] [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] [Indexed: 01/31/2023] Open
Abstract
Calponin-h1 is a 34-kDa myofibrillar thin filament, actin-binding protein that is expressed exclusively in smooth muscle cells (SMCs) in adult animals. To examine the molecular mechanisms that regulate SMC-specific gene expression, we have examined the temporal, spatial, and cell cycle-regulated patterns of expression of calponin-h1 gene expression and isolated and structurally characterized the murine calponin-h1 gene. Calponin-h1 mRNA is expressed exclusively in SMC-containing tissues in adult animals. During murine embryonic development, calponin-h1 gene expression is (i) detectable in E9.5 embryos in the dorsal aorta, cardiac outflow tract, and tubular heart, (ii) sequentially up-regulated in SMC-containing tissues, and (iii) down-regulated to non-detectable levels in the heart during late fetal development. In addition, the gene is expressed in resting rat aortic SMCs, but its expression is rapidly down-regulated when growth-arrested cells reenter phase G1 of the cell cycle and proliferate. Calponin-h1 is encoded by a 10.7-kilobase single copy gene composed of seven exons, which is part of a multigene family. Transient transfection analyses demonstrated that 1.5 kilobases of calponin-h1 5'-flanking sequence is sufficient to program high level transcription of a luciferase reporter gene in cultured primary rat aortic SMCs and the smooth muscle cell line, A7r5. Taken together, these data suggest that the calponin-h1 gene will serve as an excellent model system with which to examine the molecular mechanisms that regulate SMC lineage specification, differentiation, and phenotypic modulation.
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MESH Headings
- Amino Acid Sequence
- Animals
- Base Sequence
- Biological Evolution
- Calcium-Binding Proteins/genetics
- Calcium-Binding Proteins/metabolism
- Cell Line
- Cloning, Molecular
- DNA, Complementary
- Gene Expression Regulation, Developmental
- Humans
- Mice
- Microfilament Proteins
- Molecular Sequence Data
- Multigene Family
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/physiology
- Phenotype
- Promoter Regions, Genetic
- Rats
- Sequence Homology, Amino Acid
- Transcription, Genetic
- Calponins
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Affiliation(s)
- F F Samaha
- Department of Medicine, University of Chicago, Illinois 60637, USA
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19
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Solway J, Seltzer J, Samaha FF, Kim S, Alger LE, Niu Q, Morrisey EE, Ip HS, Parmacek MS. Structure and expression of a smooth muscle cell-specific gene, SM22 alpha. J Biol Chem 1995; 270:13460-9. [PMID: 7768949 DOI: 10.1074/jbc.270.22.13460] [Citation(s) in RCA: 216] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
SM22 alpha is expressed exclusively in smooth muscle-containing tissues of adult animals and is one of the earliest markers of differentiated smooth muscle cells (SMCs). To examine the molecular mechanisms that regulate SMC-specific gene expression, we have isolated and structurally characterized the murine SM22 alpha gene. SM22 alpha is a 6.2-kilobase single copy gene composed of five exons. SM22 alpha mRNA is expressed at high levels in the aorta, uterus, lung, and intestine, and in primary cultures of rat aortic SMCs, and the SMC line, A7r5. In contrast to genes encoding SMC contractile proteins, SM22 alpha gene expression is not decreased in proliferating SMCs. Transient transfection experiments demonstrated that 441 base pairs of SM22 alpha 5'-flanking sequence was necessary and sufficient to program high level transcription of a luciferase reporter gene in both primary rat aortic SMCs and A7r5 cells. DNA sequence analyses revealed that the 441-base pair promoter contains two CArG/SRF boxes, a CACC box, and one potential MEF-2 binding site, cis-acting elements which are each important regulators of striated muscle transcription. Taken together, these studies have identified the murine SM22 alpha promoter as an excellent model system for studies of developmentally regulated, lineage-specific gene expression in SMCs.
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Affiliation(s)
- J Solway
- Department of Medicine, University of Chicago, Illinois 60637, USA
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20
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Ip HS, Wilson DB, Heikinheimo M, Leiden JM, Parmacek MS. The GATA-4 transcription factor transactivates the cardiac-specific troponin C promoter-enhancer in non-muscle cells. Adv Exp Med Biol 1995; 382:117-24. [PMID: 8540389 DOI: 10.1007/978-1-4615-1893-8_13] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The unique contractile phenotype of cardiac myocytes is determined by the expression of a set of cardiac-specific genes. By analogy to other mammalian developmental systems, it is likely that the coordinate expression of cardiac genes is controlled by lineage-specific transcription factors that interact with promoter and enhancer elements in the transcriptional regulatory regions of these genes. Here, we demonstrate that the slow/cardiac-specific troponin C (cTnC) enhancer contains a specific binding site for the lineage-restricted, zinc finger transcription factor, GATA-4 and that GATA-4 mRNA and protein is expressed in cardiac myocytes. In addition, GATA-4 binding sites were identified in several previously characterized cardiac-specific transcriptional regulatory elements. The cTnC GATA-4 binding site is required for transcriptional enhancer activity in primary cardiac myocytes. Moreover, the cTnC enhancer can be transactivated by over-expression of GATA-4 in non-cardiac muscle cells such as NIH 3T3 cells. Taken together, these results are consistent with a model in which GATA-4 functions to direct tissue-specific gene expression during mammalian cardiac development.
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Affiliation(s)
- H S Ip
- Department of Medicine, University of Chicago, IL, USA
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21
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Ip HS, Wilson DB, Heikinheimo M, Tang Z, Ting CN, Simon MC, Leiden JM, Parmacek MS. The GATA-4 transcription factor transactivates the cardiac muscle-specific troponin C promoter-enhancer in nonmuscle cells. Mol Cell Biol 1994; 14:7517-26. [PMID: 7935467 PMCID: PMC359288 DOI: 10.1128/mcb.14.11.7517-7526.1994] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.6] [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: 01/27/2023] Open
Abstract
The unique contractile phenotype of cardiac myocytes is determined by the expression of a set of cardiac muscle-specific genes. By analogy to other mammalian developmental systems, it is likely that the coordinate expression of cardiac genes is controlled by lineage-specific transcription factors that interact with promoter and enhancer elements in the transcriptional regulatory regions of these genes. Although previous reports have identified several cardiac muscle-specific transcriptional elements, relatively little is known about the lineage-specific transcription factors that regulate these elements. In this report, we demonstrate that the slow/cardiac muscle-specific troponin C (cTnC) enhancer contains a specific binding site for the lineage-restricted zinc finger transcription factor GATA-4. This GATA-4-binding site is required for enhancer activity in primary cardiac myocytes. Moreover, the cTnC enhancer can be transactivated by overexpression of GATA-4 in non-cardiac muscle cells such as NIH 3T3 cells. In situ hybridization studies demonstrate that GATA-4 and cTnC have overlapping patterns of expression in the hearts of postimplantation mouse embryos and that GATA-4 gene expression precedes cTnC expression. Indirect immunofluorescence reveals GATA-4 expression in cultured cardiac myocytes from neonatal rats. Taken together, these results are consistent with a model in which GATA-4 functions to direct tissue-specific gene expression during mammalian cardiac development.
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Affiliation(s)
- H S Ip
- Department of Medicine, University of Chicago, IL 60637
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22
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Parmacek MS, Ip HS, Jung F, Shen T, Martin JF, Vora AJ, Olson EN, Leiden JM. A novel myogenic regulatory circuit controls slow/cardiac troponin C gene transcription in skeletal muscle. Mol Cell Biol 1994; 14:1870-85. [PMID: 8114720 PMCID: PMC358545 DOI: 10.1128/mcb.14.3.1870-1885.1994] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [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] [Indexed: 01/28/2023] Open
Abstract
The slow/cardiac troponin C (cTnC) gene is expressed in three distinct striated muscle lineages: cardiac myocytes, embryonic fast skeletal myotubes, and adult slow skeletal myocytes. We have reported previously that cTnC gene expression in cardiac muscle is regulated by a cardiac-specific promoter/enhancer located in the 5' flanking region of the gene (bp -124 to +1). In this report, we demonstrate that the cTnC gene contains a second distinct and independent transcriptional enhancer which is located in the first intron. This second enhancer is skeletal myotube specific and is developmentally up-regulated during the differentiation of myoblasts to myotubes. This enhancer contains three functionally important nuclear protein binding sites: a CACCC box, a MEF-2 binding site, and a previously undescribed nuclear protein binding site, designated MEF-3, which is also present in a large number of skeletal muscle-specific transcriptional enhancers. Unlike most skeletal muscle-specific transcriptional regulatory elements, the cTnC enhancer does not contain a consensus binding site (CANNTG) for the basic helix-loop-helix (bHLH) family of transcription factors and does not directly bind MyoD-E12 protein complexes. Despite these findings, the cTnC enhancer can be transactivated by overexpression of the myogenic bHLH proteins, MyoD and myogenin, in C3H10T1/2 (10T1/2) cells. Electrophoretic mobility shift assays demonstrated changes in the patterns of MEF-2, CACCC, and MEF-3 DNA binding activities following the conversion of 10T1/2 cells into myoblasts and myotubes by stable transfection with a MyoD expression vector. In particular, MEF-2 binding activity was up-regulated in 10T1/2 cells stably transfected with a MyoD expression vector only after these cells fused and differentiated into skeletal myotubes. Taken together, these results demonstrated that distinct lineage-specific transcriptional regulatory elements control the expression of a single myofibrillar protein gene in fast skeletal and cardiac muscle. In addition, they show that bHLH transcription factors can indirectly transactivate the expression of some muscle-specific genes.
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Affiliation(s)
- M S Parmacek
- Department of Medicine, University of Chicago, Illinois 60637
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23
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Abstract
We have demonstrated efficient protein synthesis in a cell-free system from the bloodstream form of Trypanosoma brucei. This system was able to translate endogenous mRNA, added mRNA, or (apparently at much lower efficiency) three synthetic RNA transcripts lacking 5' mini-exon and 3' poly(A) sequences. Translation was resistant to chloramphenicol and greater than 95% inhibited by low concentrations of anisomycin and puromycin, but only partially inhibited by cycloheximide. Variant surface glycoprotein synthesized from endogenous mRNA was sensitive to endoglycosidase H, indicating the co-translational glycosylation potential of the system. Two proteins translated ab initio from the corresponding in vitro-transcribed RNAs showed no evidence of signal sequence cleavage or glycosylation. Efficient processing occurred when the same RNAs were translated in a rabbit reticulocyte lysate supplemented with canine pancreatic microsomes but not with trypanosome microsomes.
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Affiliation(s)
- S N Moreno
- Rockefeller University, New York, NY 10021-6399
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24
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Abstract
Leishmania mexicana, like other species of the genus, has a major 63-kDa surface glycoprotein (gp63) that is an active protease. Reports differ as to whether gp63 is a neutral or an acidic protease. Using three radiolabeled synthetic peptide substrates, gp63 purified from L. m. mexicana is most active at pH 6.5-7.5, in three different buffer systems, and appears to be a sequence-specific endopeptidase. The full extent of sequence specificity is undetermined, but these experiments suggest a strong preference for cleavage at serine or threonine residues. In common with other metalloproteases, the cleavage is on the amino side of the recognition residue.
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Affiliation(s)
- H S Ip
- Rockefeller University, New York, NY 10021
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25
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Cully DF, Ip HS, Cross GA. Coordinate transcription of variant surface glycoprotein genes and an expression site associated gene family in Trypanosoma brucei. Cell 1985; 42:173-82. [PMID: 2861910 DOI: 10.1016/s0092-8674(85)80113-6] [Citation(s) in RCA: 150] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Trypanosoma brucei variant surface glycoprotein (VSG) genes are activated either by duplicative (DA) transposition of the gene to a pre-activated expression site or by nonduplicative (NDA) activation of a previously silent telomeric gene. We have obtained a recombinant clone spanning the 5' barren region of the expression linked copy of the duplicated VSG gene 117a. By DNA sequence and hybridization analyses we have identified a pleomorphic family of 14-25 non-VSG genes that lie upstream of both DA and NDA VSG expression sites. These expression site associated genes (ESAGs) encode 1.2 kb poly(A)+ mRNAs that are specifically transcribed from the active VSG expression telomere in mammalian bloodstream stages of T. brucei but, in common with VSG genes, are not transcribed in procyclic culture forms. cDNA and genomic sequences predict open reading frames that are conserved in the two ESAGs examined.
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Webster AD, Ip H, Pereira S. Effects of deoxyadenosine on the activation of ADA inhibited T & B cells. Clin Exp Immunol 1982; 50:587-95. [PMID: 6299634 PMCID: PMC1536814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Using an in vitro model of adenosine deaminase deficiency, we have shown that the triggering of T lymphocyte proliferation by PHA is inhibited by concentrations of deoxyadenosine likely to occur in the plasma of ADA deficient children with severe combined immunodeficiency (ADA-SCID). Prostaglandin E1 increases the sensitivity of T cells to this inhibition, suggesting that derangement of cyclic nucleotide metabolism underlies the profound T lymphopaenia seen in ADA-SCID and in patients treated with the ADA inhibitor, deoxycoformycin. The proliferation and Ig synthesis of ADA inhibited B cells stimulated with protein A and EBV is in general less sensitive to the inhibitory effects of deoxyadenosine. However, this sensitivity varies widely between experiments suggesting that other cells present in the cultures may modify the inhibitory effect of deoxyadenosine. This may help explain the variability in B cell numbers and function in patients with ADA-SCID.
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