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Relationships between cardiac structural and functional assessment by cardiac MRI and hemoglobin in end-stage renal disease. J Nephrol 2021; 34:1561-1563. [PMID: 34279812 DOI: 10.1007/s40620-021-01123-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 07/11/2021] [Indexed: 10/20/2022]
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Huang C, Liang Y, Zeng X, Yang X, Xu D, Gou X, Sathiaseelan R, Senavirathna LK, Wang P, Liu L. Long Noncoding RNA FENDRR Exhibits Antifibrotic Activity in Pulmonary Fibrosis. Am J Respir Cell Mol Biol 2020; 62:440-453. [PMID: 31697569 PMCID: PMC7110975 DOI: 10.1165/rcmb.2018-0293oc] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 11/07/2019] [Indexed: 01/01/2023] Open
Abstract
Abnormal activation of lung fibroblasts contributes to the initiation and progression of idiopathic pulmonary fibrosis (IPF). The objective of the present study was to investigate the role of fetal-lethal noncoding developmental regulatory RNA (FENDRR) in the activation of lung fibroblasts. Dysregulated long noncoding RNAs in IPF lungs were identified by next-generation sequencing analysis from the two online datasets. FENDRR expression in lung tissues from patients with IPF and mice with bleomycin-induced pulmonary fibrosis was determined by quantitative real-time PCR. IRP1 (iron-responsive element-binding protein 1), a protein partner of FENDRR, was identified by RNA pulldown-coupled mass spectrometric analysis and confirmed by RNA immunoprecipitation. The interaction region between FENDRR and IRP1 was determined by cross-linking immunoprecipitation. The in vivo role of FENDRR in pulmonary fibrosis was studied using adenovirus-mediated gene transfer in mice. The expression of FENDRR was downregulated in fibrotic human and mouse lungs as well as in primary lung fibroblasts isolated from bleomycin-treated mice. TGF-β1 (transforming growth factor-β1)-SMAD3 signaling inhibited FENDRR expression in lung fibroblasts. FENDRR was preferentially localized in the cytoplasm of adult lung fibroblasts and bound IRP1, suggesting its role in iron metabolism. FENDRR reduced pulmonary fibrosis by inhibiting fibroblast activation by reducing iron concentration and acting as a competing endogenous RNA of the profibrotic microRNA-214. Adenovirus-mediated FENDRR gene transfer in the mouse lung attenuated bleomycin-induced lung fibrosis and improved lung function. Our data suggest that FENDRR is an antifibrotic long noncoding RNA and a potential therapeutic target for pulmonary fibrosis.
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Affiliation(s)
- Chaoqun Huang
- Oklahoma Center for Respiratory and Infectious Diseases, and
- Lundberg-Kienlen Lung Biology and Toxicology Laboratory, Department of Physiological Sciences, Oklahoma State University, Stillwater, Oklahoma; and
| | - Yurong Liang
- Oklahoma Center for Respiratory and Infectious Diseases, and
- Lundberg-Kienlen Lung Biology and Toxicology Laboratory, Department of Physiological Sciences, Oklahoma State University, Stillwater, Oklahoma; and
| | - Xiangming Zeng
- Oklahoma Center for Respiratory and Infectious Diseases, and
- Lundberg-Kienlen Lung Biology and Toxicology Laboratory, Department of Physiological Sciences, Oklahoma State University, Stillwater, Oklahoma; and
| | - Xiaoyun Yang
- Oklahoma Center for Respiratory and Infectious Diseases, and
- Lundberg-Kienlen Lung Biology and Toxicology Laboratory, Department of Physiological Sciences, Oklahoma State University, Stillwater, Oklahoma; and
| | - Dao Xu
- Oklahoma Center for Respiratory and Infectious Diseases, and
- Lundberg-Kienlen Lung Biology and Toxicology Laboratory, Department of Physiological Sciences, Oklahoma State University, Stillwater, Oklahoma; and
| | - Xuxu Gou
- Oklahoma Center for Respiratory and Infectious Diseases, and
- Lundberg-Kienlen Lung Biology and Toxicology Laboratory, Department of Physiological Sciences, Oklahoma State University, Stillwater, Oklahoma; and
| | - Roshini Sathiaseelan
- Oklahoma Center for Respiratory and Infectious Diseases, and
- Lundberg-Kienlen Lung Biology and Toxicology Laboratory, Department of Physiological Sciences, Oklahoma State University, Stillwater, Oklahoma; and
| | - Lakmini Kumari Senavirathna
- Oklahoma Center for Respiratory and Infectious Diseases, and
- Lundberg-Kienlen Lung Biology and Toxicology Laboratory, Department of Physiological Sciences, Oklahoma State University, Stillwater, Oklahoma; and
| | - Pengcheng Wang
- Department of Immunology and Microbiology, Medical School of Jinan University, Guangdong, China
| | - Lin Liu
- Oklahoma Center for Respiratory and Infectious Diseases, and
- Lundberg-Kienlen Lung Biology and Toxicology Laboratory, Department of Physiological Sciences, Oklahoma State University, Stillwater, Oklahoma; and
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Greene CJ, Sharma NJ, Fiorica PN, Forrester E, Smith GJ, Gross KW, Kauffman EC. Suppressive effects of iron chelation in clear cell renal cell carcinoma and their dependency on VHL inactivation. Free Radic Biol Med 2019; 133:295-309. [PMID: 30553971 PMCID: PMC10038186 DOI: 10.1016/j.freeradbiomed.2018.12.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 12/10/2018] [Accepted: 12/12/2018] [Indexed: 02/07/2023]
Abstract
Increasing data implicate iron accumulation in tumorigenesis of the kidney, particularly the clear cell renal cell carcinoma (ccRCC) subtype. The von Hippel Lindau (VHL)/hypoxia inducible factor-α (HIF-α) axis is uniquely dysregulated in ccRCC and is a major regulator and regulatory target of iron metabolism, yet the role of iron in ccRCC tumorigenesis and its potential interplay with VHL inactivation remains unclear. We investigated whether ccRCC iron accumulation occurs due to increased cell dependency on iron for growth and survival as a result of VHL inactivation. Free iron levels were compared between four VHL-mutant ccRCC cell lines (786-0, A704, 769-P, RCC4) and two benign renal tubule epithelial cell lines (RPTEC, HRCEp) using the Phen Green SK fluorescent iron stain. Intracellular iron deprivation was achieved using two clinical iron chelator drugs, deferasirox (DFX) and deferoxamine (DFO), and chelator effects were measured on cell line growth, cell cycle phase, apoptosis, HIF-1α and HIF-2α protein levels and HIF-α transcriptional activity based on expression of target genes CA9, OCT4/POU5F1 and PDGFβ/PDGFB. Similar assays were performed in VHL-mutant ccRCC cells with and without ectopic wild-type VHL expression. Baseline free iron levels were significantly higher in ccRCC cell lines than benign renal cell lines. DFX depleted cellular free iron more rapidly than DFO and led to greater growth suppression of ccRCC cell lines (>90% at ~30-150 µM) than benign renal cell lines (~10-50% at up to 250 µM). Similar growth responses were observed using DFO, with the exception that a prolonged treatment duration was necessary to deplete cellular iron adequately for differential growth suppression of the less susceptible A704 ccRCC cell line relative to benign renal cell lines. Apoptosis and G1-phase cell cycle arrest were identified as potential mechanisms of chelator growth suppression based on their induction in ccRCC cell lines but not benign renal cell lines. Iron chelation in ccRCC cells but not benign renal cells suppressed HIF-1α and HIF-2α protein levels and transcriptional activity, and the degree and timing of HIF-2α suppression correlated with the onset of apoptosis. Restoration of wild-type VHL function in ccRCC cells was sufficient to prevent chelator-induced apoptosis and G1 cell cycle arrest, indicating that ccRCC susceptibility to iron deprivation is VHL inactivation-dependent. In conclusion, ccRCC cells are characterized by high free iron levels and a cancer-specific dependency on iron for HIF-α overexpression, cell cycle progression and apoptotic escape. This iron dependency is introduced by VHL inactivation, revealing a novel interplay between VHL/HIF-α dysregulation and ccRCC iron metabolism. Future study is warranted to determine if iron deprivation using chelator drugs provides an effective therapeutic strategy for targeting HIF-2α and suppressing tumor progression in ccRCC patients.
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Affiliation(s)
- Christopher J Greene
- Department of Urology, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14263, United States
| | - Nitika J Sharma
- Department of Urology, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14263, United States
| | - Peter N Fiorica
- Department of Urology, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14263, United States
| | - Emily Forrester
- Department of Urology, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14263, United States
| | - Gary J Smith
- Department of Urology, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14263, United States
| | - Kenneth W Gross
- Department of Molecular and Cellular Biology, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14263, United States
| | - Eric C Kauffman
- Department of Urology, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14263, United States; Department of Cancer Genetics, Roswell Park Comprehensive Cancer Center, Buffalo, NY 14263, United States; Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY 14214, United States.
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Kirk P, Sheppard M, Carpenter JP, Anderson L, He T, St Pierre T, Galanello R, Catani G, Wood J, Fucharoen S, Porter JB, Walker JM, Forni GL, Pennell DJ. Post-mortem study of the association between cardiac iron and fibrosis in transfusion dependent anaemia. J Cardiovasc Magn Reson 2017; 19:36. [PMID: 28343449 PMCID: PMC5367003 DOI: 10.1186/s12968-017-0349-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 03/01/2017] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Heart failure related to cardiac siderosis remains a major cause of death in transfusion dependent anaemias. Replacement fibrosis has been reported as causative of heart failure in siderotic cardiomyopathy in historical reports, but these findings do not accord with the reversible nature of siderotic heart failure achievable with intensive iron chelation. METHODS Ten whole human hearts (9 beta-thalassemia major, 1 sideroblastic anaemia) were examined for iron loading and fibrosis (replacement and interstitial). Five had died from heart failure, 4 had cardiac transplantation for heart failure, and 1 had no heart failure (death from a stroke). Heart samples iron content was measured using atomic emission spectroscopy. Interstitial fibrosis was quantified by computer using picrosirius red (PSR) staining and expressed as collagen volume fraction (CVF) with normal value for left ventricle <3%. RESULTS The 9 hearts affected by heart failure had severe iron loading with very low T2* of 5.0 ± 2.0 ms (iron concentration 8.5 ± 7.0 mg/g dw) and diffuse granular myocardial iron deposition. In none of the 10 hearts was significant macroscopic replacement fibrosis present. In only 2 hearts was interstitial fibrosis present, but with low CVF: in one patient with no cardiac siderosis (death by stroke, CVF 5.9%) and in a heart failure patient (CVF 2%). In the remaining 8 patients, no interstitial fibrosis was seen despite all having severe cardiac siderosis and heart failure (CVF 1.86% ±0.87%). CONCLUSION Replacement cardiac fibrosis was not seen in the 9 post-mortem hearts from patients with severe cardiac siderosis and heart failure leading to death or transplantation, which contrasts markedly to historical reports. Minor interstitial fibrosis was also unusual and very limited in extent. These findings accord with the potential for reversibility of heart failure seen in iron overload cardiomyopathy. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT00520559.
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Affiliation(s)
- Paul Kirk
- Cardiovascular Magnetic Resonance Unit, Royal Brompton Hospital, Sydney Street, SW3 6NP, London, UK
- National Heart and Lung Institute, Imperial College, London, UK
| | - Mary Sheppard
- National Heart and Lung Institute, Imperial College, London, UK
- CRY Centre for Cardiac Pathology, Royal Brompton Hospital, London, UK
| | - John-Paul Carpenter
- Cardiovascular Magnetic Resonance Unit, Royal Brompton Hospital, Sydney Street, SW3 6NP, London, UK
- National Heart and Lung Institute, Imperial College, London, UK
| | - Lisa Anderson
- Cardiovascular Magnetic Resonance Unit, Royal Brompton Hospital, Sydney Street, SW3 6NP, London, UK
- National Heart and Lung Institute, Imperial College, London, UK
| | - Taigang He
- Cardiovascular Magnetic Resonance Unit, Royal Brompton Hospital, Sydney Street, SW3 6NP, London, UK
- National Heart and Lung Institute, Imperial College, London, UK
| | | | | | | | - John Wood
- Children’s Hospital, Los Angeles, USA
| | | | - John B Porter
- The Hatter Cardiovascular Institute, University College Hospital, London, UK
| | - J Malcolm Walker
- The Hatter Cardiovascular Institute, University College Hospital, London, UK
| | | | - Dudley J Pennell
- Cardiovascular Magnetic Resonance Unit, Royal Brompton Hospital, Sydney Street, SW3 6NP, London, UK
- National Heart and Lung Institute, Imperial College, London, UK
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Woeller CF, O'Loughlin CW, Pollock SJ, Thatcher TH, Feldon SE, Phipps RP. Thy1 (CD90) controls adipogenesis by regulating activity of the Src family kinase, Fyn. FASEB J 2014; 29:920-31. [PMID: 25416548 DOI: 10.1096/fj.14-257121] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Worldwide obesity rates are at epidemic levels, and new insight into the regulation of obesity and adipogenesis are required. Thy1 (CD90), a cell surface protein with an enigmatic function, is expressed on subsets of fibroblasts and stem cells. We used a diet-induced obesity model to show that Thy1-null mice gain weight at a faster rate and gain 30% more weight than control C57BL/6 mice. During adipogenesis, Thy1 expression is lost in mouse 3T3-L1 cells. Overexpression of Thy1 blocked adipocyte formation and reduced mRNA and protein expression of an adipocyte marker, fatty acid-binding protein 4, by 5-fold. Although preadipocyte fibroblasts expressed Thy1 mRNA and protein, adipocytes from mouse and human fat tissue had almost undetectable Thy1 levels. Thy1 decreases the activity of the adipogenic transcription factor PPARγ by more than 60% as shown by PPARγ-dependent reporter assays. Using both genetic and pharmacologic approaches, we show Thy1 expression dampens PPARγ by inhibiting the activity of the Src-family kinase, Fyn. Thus, these studies reveal Thy1 blocks adipogenesis and PPARγ by inhibiting Fyn and support the idea that Thy1 is a novel therapeutic target in obesity.
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Affiliation(s)
- Collynn F Woeller
- *Department of Environmental Medicine and Flaum Eye Institute, School of Medicine and Dentistry, University of Rochester, Rochester, New York, USA
| | - Charles W O'Loughlin
- *Department of Environmental Medicine and Flaum Eye Institute, School of Medicine and Dentistry, University of Rochester, Rochester, New York, USA
| | - Stephen J Pollock
- *Department of Environmental Medicine and Flaum Eye Institute, School of Medicine and Dentistry, University of Rochester, Rochester, New York, USA
| | - Thomas H Thatcher
- *Department of Environmental Medicine and Flaum Eye Institute, School of Medicine and Dentistry, University of Rochester, Rochester, New York, USA
| | - Steven E Feldon
- *Department of Environmental Medicine and Flaum Eye Institute, School of Medicine and Dentistry, University of Rochester, Rochester, New York, USA
| | - Richard P Phipps
- *Department of Environmental Medicine and Flaum Eye Institute, School of Medicine and Dentistry, University of Rochester, Rochester, New York, USA
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Zhou S, Li M, Zeng D, Sun G, Zhou J, Wang R. Effects of basic fibroblast growth factor and cyclin D1 on cigarette smoke-induced pulmonary vascular remodeling in rats. Exp Ther Med 2014; 9:33-38. [PMID: 25452772 PMCID: PMC4247281 DOI: 10.3892/etm.2014.2044] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Accepted: 07/31/2014] [Indexed: 01/10/2023] Open
Abstract
Cigarette smoking may contribute to pulmonary hypertension in chronic obstructive pulmonary disease by resulting in pulmonary vascular remodeling that involves pulmonary artery smooth muscle cell proliferation. This study investigated the effects of basic fibroblast growth factor (bFGF) and cyclin D1 on the pulmonary vascular remodeling in smoking-exposed rats. Twenty-four male Wistar rats were randomly divided into four groups. Three tobacco-exposed groups were exposed to the smoke produced by 20 cigarettes for 60 min, twice a day for two, four or eight weeks, and the control group were exposed to fresh air. The expression of bFGF and cyclin D1 in the pulmonary arterial smooth muscle cells were determined using immunohistochemistry. Quantitative polymerase chain reaction was conducted to determine the expression levels of bFGF and cyclin D1 mRNA. In addition, the expression of bFGF and cyclin D1 proteins was evaluated by western blotting. The expression of bFGF and cyclin D1 at the mRNA and protein levels was shown to increase with the duration of smoke exposure (P<0.05). The correlation analysis indicated the expression of bFGF and cyclin D1 was positively associated with the pulmonary vessel wall thickness. The expression of bFGF was positively associated with that of cyclin D1. Collectively, the data demonstrated that the upregulation of bFGF and cyclin D1 occurred in rats subjected to smoke exposure, which may be associated with the abnormal proliferation of the smooth muscle cells in the pulmonary arteries.
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Affiliation(s)
- Sijing Zhou
- Hefei Prevention and Treatment Center for Occupational Diseases, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui 230022, P.R. China ; Department of Respiratory Medicine, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui 230022, P.R. China
| | - Min Li
- Department of Oncology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui 230022, P.R. China
| | - Daxiong Zeng
- Department of Respiratory Medicine, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215006, P.R. China
| | - Gengyun Sun
- Department of Respiratory Medicine, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui 230022, P.R. China
| | - Junsheng Zhou
- Hefei Prevention and Treatment Center for Occupational Diseases, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui 230022, P.R. China
| | - Ran Wang
- Department of Respiratory Medicine, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui 230022, P.R. China
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Zhang L, Lu D, Zhang W, Quan X, Dong W, Xu Y, Zhang L. Cardioprotection by Hepc1 in cTnT(R141W) transgenic mice. Transgenic Res 2011; 21:867-78. [PMID: 22198484 DOI: 10.1007/s11248-011-9582-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Accepted: 12/09/2011] [Indexed: 12/11/2022]
Abstract
Hepcidin 1 (Hepc1) is a peptide hormone secreted by the liver in response to iron loading. It is expressed in the heart and is thought to play a role in the regulation of iron homeostasis in an autocrine and paracrine fashion. We have shown that expression of Hepc1 is strongly down-regulated in the heart of the cTnT(R141W) transgenic mouse model of dilated cardiomyopathy (DCM) at 3 months of age. Transgenic mice with heart tissue-specific Hepc1 expression alone or in combination with the cTnT(R141W) mutation were produced to study the effects of Hepc1 on DCM. Transgenic expression of Hepc1 was found to be nonlethal and resulted in decreased mortality in cTnT(R141W) transgenic mice, from 29.6 to 7.4%(n = 27; P < 0.05), through 7 months of age. Expression of Hepc1 also brought about increases in the left ventricular wall, as well as ejection fraction and fractional shortening. In addition, the expression of Hepc1 inhibited the fibrosis and ultra-structural alterations seen in cTnT(R141W) transgenic mice. Furthermore, transgenic expression of Hepc1 restored the iron level and phosphorylation level of extracellular signal-regulated kinases 1/2 (ERK1/2) in the heart tissues of cTnT(R141W) transgenic mice. It was concluded that transgenic expression of Hepc1 compensated for the loss of Hepc1 expression and the release of iron and brought about a marked improvement in the pathologic phenotype of DCM, in which the ERK1/2 signal pathway might play an important role.
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Affiliation(s)
- Li Zhang
- Key Laboratory of Human Disease Comparative Medicine, Ministry of Health, Institute of Laboratory Animal Science, Chinese Academy of Medical Sciences and Comparative Medical Center, Peking Union Medical College, Panjiayuan Nanli, Chaoyang District, Beijing 100021, People's Republic of China
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Ruiz-Jaramillo MDLC, Guizar-Mendoza JM, Amador-Licona N, Gutierrez-Navarro MDJ, Hernandez-Gonzalez MA, Dubey-Ortega LA, Solorio-Meza SE. Iron overload as cardiovascular risk factor in children and adolescents with renal disease. Nephrol Dial Transplant 2011; 26:3268-73. [DOI: 10.1093/ndt/gfr044] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
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Kirk P, Carpenter JP, Tanner MA, Pennell DJ. Low prevalence of fibrosis in thalassemia major assessed by late gadolinium enhancement cardiovascular magnetic resonance. J Cardiovasc Magn Reson 2011; 13:8. [PMID: 21241474 PMCID: PMC3025880 DOI: 10.1186/1532-429x-13-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2011] [Accepted: 01/17/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Heart failure remains a major cause of mortality in thalassaemia major. The possible role of cardiac fibrosis in thalassemia major in the genesis of heart failure is not clear. It is also unclear whether cardiac fibrosis might arise as a result of heart failure. METHODS We studied 45 patients with thalassaemia major who had a wide range of current cardiac iron loading and included patients with prior and current heart failure. Myocardial iron was measured using T2* cardiovascular magnetic resonance (CMR), and following this, late gadolinium enhancement (LGE) was used to determine the presence of macroscopic myocardial fibrosis. RESULTS The median myocardial T2* in all patients was 22.6 ms (range 5.3-58.8 ms). Fibrosis was detected in only one patient, whose myocardial T2* was 20.1 ms and left ventricular ejection fraction 57%. No fibrosis was identified in 5 patients with a history of heart failure with full recovery, in 3 patients with current left ventricular dysfunction undergoing treatment, or in 18 patients with myocardial iron loading with cardiacT2* < 20 ms at the time of scan. CONCLUSION This study shows that macroscopic myocardial fibrosis is uncommon in thalassemia major across a broad spectrum of myocardial iron loading. Importantly, there was no macroscopic fibrosis in patients with current or prior heart failure, or in patients with myocardial iron loading without heart failure. Therefore if myocardial fibrosis indeed contributes to myocardial dysfunction in thalassemia, our data combined with the knowledge that the myocardial dysfunction of iron overload can be reversed, indicates that any such fibrosis would need to be both microscopic and reversible.
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Affiliation(s)
- Paul Kirk
- Royal Brompton Hospital and Imperial College, London, UK
| | | | - Mark A Tanner
- Royal Brompton Hospital and Imperial College, London, UK
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