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Azzalini L, Johal GS. Complex and High-Risk Percutaneous Coronary Intervention at Centers With No Surgical Back-Up: Are We Ready for Prime Time? Can J Cardiol 2024:S0828-282X(24)00161-2. [PMID: 38369257 DOI: 10.1016/j.cjca.2024.02.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 02/09/2024] [Accepted: 02/13/2024] [Indexed: 02/20/2024] Open
Affiliation(s)
- Lorenzo Azzalini
- Division of Cardiology, Department of Medicine, University of Washington, Seattle, Washington, USA.
| | - Gurpreet S Johal
- Division of Cardiology, Department of Medicine, University of Washington-Valley Medical Center, Renton, Washington, USA
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Azzalini L, Baber U, Johal GS, Farhan S, Barman N, Kapur V, Hasan C, Vijay P, Jhaveri V, Mehran R, Kini AS, Sharma SK. One-year outcomes of patients undergoing complex percutaneous coronary intervention with three contemporary drug-eluting stents. Catheter Cardiovasc Interv 2021; 97:1341-1351. [PMID: 32478459 DOI: 10.1002/ccd.28996] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 05/12/2020] [Indexed: 12/31/2022]
Abstract
OBJECTIVES We aimed to evaluate the 1-year outcomes of three everolimus-eluting stents (EES) for complex percutaneous coronary intervention (PCI). BACKGROUND It is controversial whether contemporary bioresorbable-polymer drug-eluting stents (BP-DES) are associated with better outcomes compared with durable-polymer DES (DP-DES). METHODS Patients undergoing PCI with cobalt-chromium (CoCr)-DP-EES (Xience), platinum-chromium (PtCr)-DP-EES (Promus), or PtCr-BP-EES (Synergy) at one high-volume institution between 2015 and 2017 were included. The primary endpoint was 1-year major adverse cardiac events (MACE), a composite of death, myocardial infarction, and target-vessel revascularization. Associations were also examined in patients undergoing complex PCI. Multivariable analysis was conducted to adjust for baseline differences across groups. RESULTS We included n = 5,446 patients (CoCr-DP-EES, n = 3,177; PtCr-DP-EES, n = 1,555; PtCr-BP-EES, n = 714). Patients treated with PtCr-BP-EES had higher comorbidity burden and procedural complexity. At 1 year, MACE rates were 8.9% for CoCr-DP-EES versus 8.9% for PtCr-DP-EES versus 8.6% for PtCr-BP-EES (p = .97). The incidence of definite/probable stent thrombosis (ST) was also similar (0.6 vs. 0.4 vs. 0.3%, p = .69). Complex PCI was performed in n = 2,894/5,446 (53.1%). At 1 year, MACE rates were 11.5 versus 10.7 versus 10.3%, respectively (p = .83). The incidence of definite/probable ST was also similar (0.9 vs. 0.3 vs. 0.3%, p = .22). On multivariable analysis, stent type was not an independent predictor of MACE either in the overall or in the complex PCI population. CONCLUSIONS We observed comparable 1-year rates of MACE and definite/probable ST in patients undergoing PCI with CoCr-DP-EES, PtCr-DP-EES, and PtCr-BP-EES. Results were unchanged among patients undergoing complex PCI. Future multicenter randomized studies should confirm and extend our findings.
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Affiliation(s)
- Lorenzo Azzalini
- The Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Usman Baber
- The Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Gurpreet S Johal
- The Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Serdar Farhan
- The Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Nitin Barman
- The Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Vishal Kapur
- The Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Choudhury Hasan
- The Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Pooja Vijay
- The Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Vaishvi Jhaveri
- The Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Roxana Mehran
- The Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Annapoorna S Kini
- The Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Samin K Sharma
- The Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, New York, USA
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Muralidharan TR, Ramesh S, Kumar BV, Ruia AV, Kumar M, Gopalakrishnan A, Johal GS, Hooda A, Malhotra R, Masoomi R, Ramadoss M, Subramanian V, Kalsingh MJ, Manokar P, Rathinasamy J, Sadhanandham S, Balasubramaniyan JV, Krishnamurthy P, Murthy JS, Thanikachalam S, Senguttuvan NB. Clinical profile and management of patients with acute pulmonary thromboembolism - a single centre, large observational study from India. Pulm Circ 2021; 11:2045894021992678. [PMID: 34104416 PMCID: PMC8164559 DOI: 10.1177/2045894021992678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 01/17/2021] [Indexed: 12/02/2022] Open
Abstract
Acute pulmonary thromboembolism is associated with high mortality, similar to
that of myocardial infarction and stroke. We studied the clinical presentation
and management of pulmonary thromboembolism in the Indian population. An
analysis of 140 patients who presented with acute pulmonary thromboembolism at a
large volume center in India from June 2015 through December 2018 was performed.
The mean age of our study population was 50 years with 59% being male.
Comorbidities including deep vein thrombosis, diabetes mellitus, hypertension,
and chronic obstructive pulmonary disease were present in 52.9%, 40%, 35.7% and
7.14% of patients, respectively. Out of 140 patients, 40 (28.6%) patients had
massive pulmonary thromboembolism, 36 (25.7%) sub-massive pulmonary
thromboembolism, and 64 (45.7%) had low-risk pulmonary thromboembolism. Overall,
in-hospital mortality was 25.7%. Multivariate regression analysis found chronic
kidney disease and pulmonary thromboembolism severity to be the only independent
risk factors. Thrombolysis was performed in 62.5% of patients with a massive
pulmonary thromboembolism and 63.9% of patients with a sub-massive pulmonary
thromboembolism. In the massive pulmonary thromboembolism group, patients
receiving thrombolytic therapy had lower mortality compared with patients who
did not receive therapy (p=0.022), whereas this difference was
not observed in patients in the sub-massive pulmonary thromboembolism group. We
conclude that patients with acute pulmonary thromboembolism in India presented
more than a decade earlier than our western counterparts, and it was associated
with poor clinical outcomes. Thrombolysis was associated with significantly
reduced in-hospital mortality in patients with massive pulmonary
thromboembolism.
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Affiliation(s)
| | - Sankaran Ramesh
- Department of Cardiology, Sri Ramachandra Institute of Higher Education and Research (SRIHER), Chennai, India
| | - Balakrishnan Vinod Kumar
- Department of Cardiology, Sri Ramachandra Institute of Higher Education and Research (SRIHER), Chennai, India
| | - Aditya V Ruia
- Department of Cardiology, Sri Ramachandra Institute of Higher Education and Research (SRIHER), Chennai, India
| | - Mohan Kumar
- Department of Cardiology, Sri Ramachandra Institute of Higher Education and Research (SRIHER), Chennai, India
| | | | - Gurpreet S Johal
- Division of Interventional Cardiology, Mount Sinai School of Medicine, New York, NY, USA
| | - Amit Hooda
- Division of Interventional Cardiology, Mount Sinai School of Medicine, New York, NY, USA
| | - Rohit Malhotra
- Division of Interventional Cardiology, Mount Sinai School of Medicine, New York, NY, USA
| | - Reza Masoomi
- Division of Interventional Cardiology, Mount Sinai School of Medicine, New York, NY, USA
| | - Mahalakshmi Ramadoss
- Faculty of Clinical Research, Sri Ramachandra Institute of Higher Education and Research (SRIHER), Chennai, India
| | - Vinodhini Subramanian
- Department of Cardiology, Sri Ramachandra Institute of Higher Education and Research (SRIHER), Chennai, India
| | | | - Panchanatham Manokar
- Department of Cardiology, Sri Ramachandra Institute of Higher Education and Research (SRIHER), Chennai, India
| | - Jebaraj Rathinasamy
- Department of Cardiology, Sri Ramachandra Institute of Higher Education and Research (SRIHER), Chennai, India
| | | | - Jayanthy V Balasubramaniyan
- Department of Cardiology, Sri Ramachandra Institute of Higher Education and Research (SRIHER), Chennai, India
| | - Preetam Krishnamurthy
- Department of Cardiology, Sri Ramachandra Institute of Higher Education and Research (SRIHER), Chennai, India
| | - Jayanthy S Murthy
- Department of Cardiology, Sri Ramachandra Institute of Higher Education and Research (SRIHER), Chennai, India
| | - Sadagopan Thanikachalam
- Department of Cardiology, Sri Ramachandra Institute of Higher Education and Research (SRIHER), Chennai, India
| | - Nagendra Boopathy Senguttuvan
- Department of Cardiology, Sri Ramachandra Institute of Higher Education and Research (SRIHER), Chennai, India.,Adjunct Faculty, Department of Engineering & Design Indian Institute of Technology (IIT-M) Chennai, Tamil Nadu
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Ojeda S, Azzalini L, Suárez de Lezo J, Johal GS, González R, Barman N, Hidalgo F, Bellera N, Dangas G, Jurado‐Román A, Kini A, Romero M, Moreno R, Garcia del Blanco B, Mehran R, Sharma SK, Pan M. Excimer laser coronary atherectomy for uncrossable coronary lesions. A multicenter registry. Catheter Cardiovasc Interv 2020; 98:1241-1249. [DOI: 10.1002/ccd.29392] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 10/27/2020] [Accepted: 11/08/2020] [Indexed: 12/12/2022]
Affiliation(s)
- Soledad Ojeda
- Division of Interventional Cardiology, Reina Sofia Hospital University of Córdoba, Maimonides Institute for Research in Biomedicine of Córdoba (IMIBIC) Córdoba Spain
| | - Lorenzo Azzalini
- Division of Cardiology, VCU Health Pauley Heart Center Virginia Commonwealth University Richmond Virginia USA
- The Zena and Michael A. Wiener Cardiovascular Institute Icahn School of Medicine at Mount Sinai New York New York USA
| | - Javier Suárez de Lezo
- Division of Interventional Cardiology, Reina Sofia Hospital University of Córdoba, Maimonides Institute for Research in Biomedicine of Córdoba (IMIBIC) Córdoba Spain
| | - Gurpreet S. Johal
- The Zena and Michael A. Wiener Cardiovascular Institute Icahn School of Medicine at Mount Sinai New York New York USA
| | - Rafael González
- Division of Interventional Cardiology, Reina Sofia Hospital University of Córdoba, Maimonides Institute for Research in Biomedicine of Córdoba (IMIBIC) Córdoba Spain
| | - Nitin Barman
- The Zena and Michael A. Wiener Cardiovascular Institute Icahn School of Medicine at Mount Sinai New York New York USA
| | - Francisco Hidalgo
- Division of Interventional Cardiology, Reina Sofia Hospital University of Córdoba, Maimonides Institute for Research in Biomedicine of Córdoba (IMIBIC) Córdoba Spain
| | - Neus Bellera
- Division of Interventional Cardiology Hospital Universitario Vall d'Hebron, Centro de Investigación Biomédica en Red, CIBER CV Barcelona Spain
| | - George Dangas
- The Zena and Michael A. Wiener Cardiovascular Institute Icahn School of Medicine at Mount Sinai New York New York USA
| | - Alfonso Jurado‐Román
- Division of Interventional Cardiology Hospital La Paz, IDIPAZ, CIBER‐CV Madrid Spain
| | - Annapoorna Kini
- The Zena and Michael A. Wiener Cardiovascular Institute Icahn School of Medicine at Mount Sinai New York New York USA
| | - Miguel Romero
- Division of Interventional Cardiology, Reina Sofia Hospital University of Córdoba, Maimonides Institute for Research in Biomedicine of Córdoba (IMIBIC) Córdoba Spain
| | - Raúl Moreno
- Division of Interventional Cardiology Hospital La Paz, IDIPAZ, CIBER‐CV Madrid Spain
| | - Bruno Garcia del Blanco
- Division of Interventional Cardiology Hospital Universitario Vall d'Hebron, Centro de Investigación Biomédica en Red, CIBER CV Barcelona Spain
| | - Roxana Mehran
- The Zena and Michael A. Wiener Cardiovascular Institute Icahn School of Medicine at Mount Sinai New York New York USA
| | - Samin K. Sharma
- The Zena and Michael A. Wiener Cardiovascular Institute Icahn School of Medicine at Mount Sinai New York New York USA
| | - Manuel Pan
- Division of Interventional Cardiology, Reina Sofia Hospital University of Córdoba, Maimonides Institute for Research in Biomedicine of Córdoba (IMIBIC) Córdoba Spain
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Hooda A, Masoomi R, Jain T, Johal GS, Barman N, Sharma SK. Rotational Atherectomy Induced Coronary Perforation of Right Coronary Artery Draining into Middle Cardiac Vein. JACC Case Rep 2020; 2:1688-1691. [PMID: 34317035 PMCID: PMC8312102 DOI: 10.1016/j.jaccas.2020.07.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 07/16/2020] [Indexed: 11/29/2022]
Abstract
Ellis Type III cavity spilling coronary perforation is a rare complication. We report to our knowledge, the first case of rotational atherectomy induced Type III cavity spilling coronary perforation of right posterior descending artery draining into middle cardiac vein, successfully managed by covered stent deployment. (Level of Difficulty: Advanced.)
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Affiliation(s)
- Amit Hooda
- Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Reza Masoomi
- Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Tarun Jain
- Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Gurpreet S Johal
- Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Nitin Barman
- Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, New York
| | - Samin K Sharma
- Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai, New York, New York
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Azzalini L, Johal GS, Baber U, Bander J, Moreno PR, Bazi L, Kapur V, Barman N, Kini AS, Sharma SK. Outcomes of Impella‐supported high‐risk nonemergent percutaneous coronary intervention in a large single‐center registry. Catheter Cardiovasc Interv 2020; 97:E26-E33. [DOI: 10.1002/ccd.28931] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 03/27/2020] [Accepted: 04/12/2020] [Indexed: 11/10/2022]
Affiliation(s)
- Lorenzo Azzalini
- The Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai New York New York USA
| | - Gurpreet S. Johal
- The Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai New York New York USA
| | - Usman Baber
- The Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai New York New York USA
| | - Jeffrey Bander
- The Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai New York New York USA
| | - Pedro R. Moreno
- The Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai New York New York USA
| | - Lucas Bazi
- The Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai New York New York USA
| | - Vishal Kapur
- The Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai New York New York USA
| | - Nitin Barman
- The Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai New York New York USA
| | - Annapoorna S. Kini
- The Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai New York New York USA
| | - Samin K. Sharma
- The Zena and Michael A. Wiener Cardiovascular Institute, Icahn School of Medicine at Mount Sinai New York New York USA
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7
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Nadimpalli R, Yalpani N, Johal GS, Simmons CR. Prohibitins, stomatins, and plant disease response genes compose a protein superfamily that controls cell proliferation, ion channel regulation, and death. J Biol Chem 2000; 275:29579-86. [PMID: 10862763 DOI: 10.1074/jbc.m002339200] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.5] [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: 11/06/2022] Open
Abstract
Prohibitins, stomatins, and a group of plant defense response genes are demonstrated to belong to a novel protein superfamily. This superfamily is bound by similar primary and secondary predicted protein structures and hydropathy profiles. A PROSITE-formatted regular expression was generated that is highly predictive for identifying members of this superfamily using PHI-BLAST. The superfamily is named PID (proliferation, ion, and death) because prohibitins are involved in proliferation and cell cycle control, stomatins are involved in ion channel regulation, and the plant defense-related genes are involved in cell death. The plant defense gene family is named HIR (hypersensitive induced reaction) because its members are associated with hypersensitive reactions involving cell death and pathogen resistance. For this study, eight novel maize genes were introduced: four closely related to prohibitins (Zm-phb1, Zm-phb2, Zm-phb3, and Zm-phb4), one to stomatins (Zm-stm1), and three to a gene implicated in plant disease responses (Zm-hir1, Zm-hir2, and Zm-hir3). The maize Zm-hir3 gene transcript is up-regulated in a disease lesion mimic mutation (Les9), supporting a role in maize defense responses. Members of this gene superfamily are involved in diverse functions, but their structural similarity suggests a conserved molecular mechanism, which we postulate to be ion channel regulation.
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Affiliation(s)
- R Nadimpalli
- Hoffmann-La Roche, Vitamins Division, Nutley, New Jersey 07110, USA
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8
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Hu G, Yalpani N, Briggs SP, Johal GS. A porphyrin pathway impairment is responsible for the phenotype of a dominant disease lesion mimic mutant of maize. Plant Cell 1998; 10:1095-1105. [PMID: 9668130 PMCID: PMC144048 DOI: 10.1105/tpc.10.7.1095] [Citation(s) in RCA: 160] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The maize lesion mimic gene Les22 is defined by dominant mutations and characterized by the production of minute necrotic spots on leaves in a developmentally specified and light-dependent manner. Phenotypically, Les22 lesions resemble those that are triggered during a hypersensitive disease resistance response of plants to pathogens. We have cloned Les22 by using a Mutator-tagging technique. It encodes uroporphyrinogen decarboxylase (UROD), a key enzyme in the biosynthetic pathway of chlorophyll and heme in plants. Urod mutations in humans are also dominant and cause the metabolic disorder porphyria, which manifests itself as light-induced skin morbidity resulting from an excessive accumulation of photoexcitable uroporphyrin. The phenotypic and genetic similarities between porphyria and Les22 along with our observation that Les22 is also associated with an accumulation of uroporphyrin revealed what appears to be a case of natural porphyria in plants.
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Affiliation(s)
- G Hu
- Department of Agronomy, University of Missouri, Columbia, Missouri 65211, USA
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9
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Hu G, Yalpani N, Briggs SP, Johal GS. A porphyrin pathway impairment is responsible for the phenotype of a dominant disease lesion mimic mutant of maize. Plant Cell 1998; 10:1095-1105. [PMID: 9668130 DOI: 10.2307/3870714] [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: 05/28/2023]
Abstract
The maize lesion mimic gene Les22 is defined by dominant mutations and characterized by the production of minute necrotic spots on leaves in a developmentally specified and light-dependent manner. Phenotypically, Les22 lesions resemble those that are triggered during a hypersensitive disease resistance response of plants to pathogens. We have cloned Les22 by using a Mutator-tagging technique. It encodes uroporphyrinogen decarboxylase (UROD), a key enzyme in the biosynthetic pathway of chlorophyll and heme in plants. Urod mutations in humans are also dominant and cause the metabolic disorder porphyria, which manifests itself as light-induced skin morbidity resulting from an excessive accumulation of photoexcitable uroporphyrin. The phenotypic and genetic similarities between porphyria and Les22 along with our observation that Les22 is also associated with an accumulation of uroporphyrin revealed what appears to be a case of natural porphyria in plants.
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Affiliation(s)
- G Hu
- Department of Agronomy, University of Missouri, Columbia, Missouri 65211, USA
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10
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Multani DS, Meeley RB, Paterson AH, Gray J, Briggs SP, Johal GS. Plant-pathogen microevolution: molecular basis for the origin of a fungal disease in maize. Proc Natl Acad Sci U S A 1998; 95:1686-91. [PMID: 9465077 PMCID: PMC19149 DOI: 10.1073/pnas.95.4.1686] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
A new and severe disease of maize caused by a previously unknown fungal pathogen, Cochliobolus carbonum race 1, was first described in 1938. The molecular events that led to the sudden appearance of this disease are described in this paper. Resistance to C. carbonum race 1 was found to be widespread in maize and is conferred by a pair of unlinked duplicate genes, Hm1 and Hm2. Here, we demonstrate that resistance is the wild-type condition in maize. Two events, a transposon insertion in Hm1 and a deletion in Hm2, led to the loss of resistance, resulting in the origin of a new disease. None of the other plant species tested is susceptible to C. carbonum race 1, and they all possess candidate genes with high homology to Hm1 and Hm2. In sorghum and rice, these homologs map to two chromosomal regions that are syntenic with the maize Hm1 and Hm2 loci, indicating that they are related to the maize genes by vertical descent. These results suggest that the Hm-encoded resistance is of ancient origin and probably is conserved in all grasses.
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Affiliation(s)
- D S Multani
- Department of Agronomy, 205 Curtis Hall, University of Missouri, Columbia, MO 65211-7020, USA
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Abstract
The Lls1 (lethal leaf spot1) locus of maize is defined by a recessive mutation characterized by the initiation, in a developmentally programmed manner, of necrotic lesions that expand to kill leaves cell autonomously. The loss-of-function nature of all Lls1 mutants implies that the Lls1 gene is required to limit the spread of cell death in mature leaves. We have cloned the Lls1 gene by tagging with Mutator, a transposable element system in maize, and we show that it encodes a novel protein highly conserved in plants. Two consensus binding motifs of aromatic ring-hydroxylating dioxygenases are present in the predicted LLS1 protein, suggesting that it may function to degrade a phenolic mediator of cell death.
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Affiliation(s)
- J Gray
- Department of Agronomy, University of Missouri, Columbia 65211, USA
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Abstract
The Anther ear1 (An1) gene product is involved in the synthesis of ent-kaurene, the first tetracyclic intermediate in the gibberellin (GA) biosynthetic pathway. Mutations causing the loss of An1 function result in a GA-responsive phenotype that includes reduced plant height, delayed maturity, and development of perfect flowers on normally pistillate ears. The an1::Mu2-891339 allele was recovered from a Mutator (Mu) F2 family. Using Mu elements as molecular probes, an An1-containing restriction fragment was identified and cloned. The identity of the cloned gene as An1 was confirmed by using a reverse genetics screen for maize families that contain a Mu element inserted into the cloned gene and then by demonstrating that the insertion causes an an1 phenotype. The predicted amino acid sequence of the An1 cDNA shares homology with plant cyclases and contains a basic N-terminal sequence that may target the An1 gene product to the chloroplast. The sequence is consistent with the predicted subcellular localization of AN1 in the chloroplast and with its biochemical role in the cyclization of geranylgeranyl pyrophosphate, a 20-carbon isoprenoid, to ent-kaurene. The semidwarfed stature of an1 mutants is in contrast with the more severely dwarfed stature of GA-responsive mutants at other loci in maize and may be caused by redundancy in this step of the GA biosynthetic pathway. DNA gel blot analysis indicated that An1 is a single-copy gene that lies entirely within the deletion of the an1-bz2-6923 mutant. However, homozygous deletion mutants accumulated ent-kaurene to 20% of the wild-type level, suggesting that the function of An1 is supplemented by an additional activity.
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Affiliation(s)
- R J Bensen
- Pioneer Hi-Bred International, Inc., Johnston, Iowa 50131
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Abstract
A parasite's ability to infect and a host's ability to resist infection can be heritable traits. Patterns of inheritance suggest how host genes interact with parasite genes to determine whether or not infection occurs. Recent progress in the isolation and characterization of these genes in plants sheds new light on parasitism.
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Affiliation(s)
- S P Briggs
- Department of Biotechnology Research, Pioneer Hi-Bred International, Johnston, IA 50131
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14
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Abstract
The HM1 gene in maize controls both race-specific resistance to the fungus Cochliobolus carbonum race 1 and expression of the NADPH (reduced form of nicotinamide adenine dinucleotide phosphate)-dependent HC toxin reductase (HCTR), which inactivates HC toxin, a cyclic tetrapeptide produced by the fungus to permit infection. Several HM1 alleles were generated and cloned by transposon-induced mutagenesis. The sequence of wild-type HM1 shares homology with dihydroflavonol-4-reductase genes from maize, petunia, and snap-dragon. Sequence homology is greatest in the beta alpha beta-dinucleotide binding fold that is conserved among NADPH- and NADH (reduced form of nicotinamide adenine dinucleotide)-dependent reductases and dehydrogenases. This indicates that HM1 encodes HCTR.
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Affiliation(s)
- G S Johal
- Department of Biotechnology Research, Pioneer Hi-Bred International, Inc., Johnston, IA 50131
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