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Kerns SL, Williams JP, Marples B. Modeling normal bladder injury after radiation therapy. Int J Radiat Biol 2023; 99:1046-1054. [PMID: 36854008 PMCID: PMC10330568 DOI: 10.1080/09553002.2023.2182000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 02/03/2023] [Accepted: 02/06/2023] [Indexed: 03/02/2023]
Abstract
PURPOSE For decades, Dr. John Moulder has been a leading radiation biologist and one of the few who consistently supported the study of normal tissue responses to radiation. His meticulous modeling and collaborations across the field have offered a prime example of how research can be taken from the bench to the bedside and back, with the ultimate goal of providing benefit to patients. Much of the focus of John's work was on mitigating damage to the kidney, whether as the result of accidental or deliberate clinical exposures. Following in his footsteps, we offer here a brief overview of work conducted in the field of radiation-induced bladder injury. We then describe our own preclinical experimental studies which originated as a response to reports from a clinical genome-wide association study (GWAS) investigating genomic biomarkers of normal tissue toxicity in prostate cancer patients treated with radiotherapy. In particular, we discuss the use of Renin-Angiotensin System (RAS) inhibitors as modulators of injury, agents championed by the Moulder group, and how RAS inhibitors are associated with a reduction in some measures of toxicity. Using a murine model, along with precise CT-image guided irradiation of the bladder using single and fractionated dosing regimens, we have been able to demonstrate radiation-induced functional injury to the bladder and mitigation of this functional damage by an inhibitor of angiotensin-converting enzyme targeting the RAS, an experimental approach akin to that used by the Moulder group. We consider our scientific trajectory as a bedside-to-bench approach because the observation was made clinically and investigated in a preclinical model; this experimental approach aligns with the exemplary career of Dr. John Moulder. CONCLUSIONS Despite the differences in functional endpoints, recent findings indicate a commonality between bladder late effects and the work in kidney pioneered by Dr. John Moulder. We offer evidence that targeting the RAS pathway may provide a targetable pathway to reducing late bladder toxicity.
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Affiliation(s)
- Sarah L. Kerns
- Department of Department of Radiation Oncology, the Medical College of Wisconsin, Milwaukee, WI, USA
| | - Jacqueline P. Williams
- Departments of Environmental Medicine, University of Rochester Medical Center, Rochester, NY, USA
- Departments of Radiation Oncology, University of Rochester Medical Center, Rochester, NY, USA
| | - Brian Marples
- Departments of Radiation Oncology, University of Rochester Medical Center, Rochester, NY, USA
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Singh VK, Seed TM. A review of radiation countermeasures focusing on injury-specific medicinals and regulatory approval status: part I. Radiation sub-syndromes, animal models and FDA-approved countermeasures. Int J Radiat Biol 2017. [PMID: 28650707 DOI: 10.1080/09553002.2017.1332438] [Citation(s) in RCA: 119] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
PURPOSE The increasing global risk of nuclear and radiological accidents or attacks has driven renewed research interest in developing medical countermeasures to potentially injurious exposures to acute irradiation. Clinical symptoms and signs of a developing acute radiation injury, i.e. the acute radiation syndrome, are grouped into three sub-syndromes named after the dominant organ system affected, namely the hematopoietic, gastrointestinal, and neurovascular systems. The availability of safe and effective countermeasures against the above threats currently represents a significant unmet medical need. This is the first article within a three-part series covering the nature of the radiation sub-syndromes, various animal models for radiation countermeasure development, and the agents currently approved by the United States Food and Drug Administration for countering the medical consequences of several of these prominent radiation exposure-associated syndromes. CONCLUSIONS From the U.S. and global perspectives, biomedical research concerning medical countermeasure development is quite robust, largely due to increased government funding following the 9/11 incidence and subsequent rise of terrorist-associated threats. A wide spectrum of radiation countermeasures for specific types of radiation injuries is currently under investigation. However, only a few radiation countermeasures have been fully approved by regulatory agencies for human use during radiological/nuclear contingencies. Additional research effort, with additional funding, clearly will be needed in order to fill this significant, unmet medical health problem.
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Affiliation(s)
- Vijay K Singh
- a Division of Radioprotection, Department of Pharmacology and Molecular Therapeutics , F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences , Bethesda , MD , USA.,b Armed Forces Radiobiology Research Institute , Uniformed Services University of the Health Sciences , Bethesda , MD , USA
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Cohen EP, Fish BL, Imig JD, Moulder JE. Mitigation of normal tissue radiation injury: evidence from rat radiation nephropathy models. ACTA ACUST UNITED AC 2015. [DOI: 10.1007/s13566-015-0222-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Harder EM, Park HS, Nath SK, Mancini BR, Decker RH. Angiotensin-converting enzyme inhibitors decrease the risk of radiation pneumonitis after stereotactic body radiation therapy. Pract Radiat Oncol 2015; 5:e643-9. [PMID: 26412341 DOI: 10.1016/j.prro.2015.07.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Revised: 06/10/2015] [Accepted: 07/13/2015] [Indexed: 12/25/2022]
Abstract
PURPOSE Although angiotensin-converting enzyme (ACE) inhibitor use during conventionally fractionated radiation therapy has been associated with a decreased risk of radiation pneumonitis (RP), a similar effect has not been demonstrated in stereotactic body radiation therapy (SBRT). The purpose of this study was to examine the impact of ACE inhibitor use during SBRT on the risk of symptomatic (grade ≥2) RP. METHODS AND MATERIALS Patients with at least 1 follow-up treated with SBRT for primary lung cancer were included. ACE inhibitors, angiotensin receptor blockers, statins, nonsteroidal anti-inflammatory drugs, and glucocorticoids were examined. RP was determined from all available medical records, including follow-up appointments with radiation oncology, pulmonology, medical oncology, and hospitalizations. It was scored with the Common Terminology Criteria for Adverse Events, version 4.0. Analysis was performed with Kaplan-Meier and Cox proportional hazards modeling. RESULTS A total of 257 patients met inclusion criteria. Seventy (27.2%) used an ACE inhibitor during SBRT. The overall rates of grade ≥2 and ≥3 RP were 19.1% (n = 49) and 7.0% (n = 18), respectively. ACE inhibitor users experienced greater freedom from symptomatic RP on univariate (vs nonusers, 89.8% vs 76.3% at 12 months, P = .029) and multivariate analysis (hazard ratio 0.373, 95% confidence interval 0.156-0.891, P =.026). The volume of normal lung tissue receiving ≥5 Gy, %, ≥10 Gy, ≥20 Gy, and mean lung dose were also significantly associated with RP on univariate and multivariate analysis. ACE inhibitor use was not associated with overall survival. Angiotensin receptor blockers, nonsteroidal anti-inflammatory drugs, glucocorticoids, and statin administration were not associated with symptomatic RP or survival. CONCLUSIONS ACE inhibitor use during SBRT was associated with significantly greater freedom from grade ≥2 RP, even after adjusting for pulmonary dose. Given the data on their protective effect in human and animal models, a prospective evaluation is warranted.
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Affiliation(s)
- Eileen M Harder
- Department of Therapeutic Radiology Yale University School of Medicine, Yale Cancer Center, New Haven, Connecticut
| | - Henry S Park
- Department of Therapeutic Radiology Yale University School of Medicine, Yale Cancer Center, New Haven, Connecticut
| | - Sameer K Nath
- Department of Therapeutic Radiology Yale University School of Medicine, Yale Cancer Center, New Haven, Connecticut
| | - Brandon R Mancini
- Department of Therapeutic Radiology Yale University School of Medicine, Yale Cancer Center, New Haven, Connecticut
| | - Roy H Decker
- Department of Therapeutic Radiology Yale University School of Medicine, Yale Cancer Center, New Haven, Connecticut.
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Moulder JE, Cohen EP, Fish BL. Mitigation of experimental radiation nephropathy by renin-equivalent doses of angiotensin converting enzyme inhibitors. Int J Radiat Biol 2014; 90:762-8. [PMID: 24991882 DOI: 10.3109/09553002.2014.938375] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
PURPOSE We tested five different angiotensin converting enzyme inhibitors (ACEI) as mitigators of experimental radiation nephropathy at drug doses calibrated to the plasma renin activity (PRA). This was done to determine whether all ACEI had the same efficacy as mitigators of radiation nephropathy when used at drug doses that gave equivalent suppression of the renin angiotensin system. METHOD 10 Gy total body irradiation with bone marrow transplantation was used to cause radiation nephropathy in barrier-maintained rats. Equivalent ACEI doses were determined based on their effect to inhibit angiotensin converting enzyme (ACE) and raise the PRA in unirradiated animals. RESULTS PRA-equivalent doses were found for captopril, lisinopril, enalapril, ramipril and fosinopril. These doses overlap the human doses of these drugs on a body surface area basis. All ACE inhibitors, except fosinopril, mitigated radiation nephropathy; captopril was a somewhat better mitigator than lisinopril, enalapril or ramipril. CONCLUSIONS Most, but not all, ACEI mitigate radiation nephropathy at doses that overlap their clinically-used doses (on a body surface area basis). Fosinopril is known to be an ineffective mitigator of radiation pneumonitis, and it also does not mitigate radiation nephropathy. These pre-clinical data are critical in planning human studies of the mitigation of normal tissue radiation injury.
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Affiliation(s)
- John E Moulder
- Radiation Oncology, Medical College of Wisconsin , Milwaukee , Wisconsin
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Medhora M, Gao F, Wu Q, Molthen RC, Jacobs ER, Moulder JE, Fish BL. Model development and use of ACE inhibitors for preclinical mitigation of radiation-induced injury to multiple organs. Radiat Res 2014; 182:545-55. [PMID: 25361399 DOI: 10.1667/rr13425.1] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The NIH/NIAID initiated a countermeasure program to develop mitigators for radiation-induced injuries from a radiological attack or nuclear accident. We have previously characterized and demonstrated mitigation of single organ injuries, such as radiation pneumonitis, pulmonary fibrosis or nephropathy by angiotensin converting enzyme (ACE) inhibitors. Our current work extends this research to examine the potential for mitigating multiple organ dysfunctions occurring in the same irradiated rats. Using total body irradiation (TBI) followed by bone marrow transplant, we tested four doses of X radiation (11, 11.25, 11.5 and 12 Gy) to develop lethal late effects. We identified three of these doses (11, 11.25 and 11.5 Gy TBI) that were lethal to all irradiated rats by 160 days to test mitigation by ACE inhibitors of injury to the lungs and kidneys. In this study we tested three ACE inhibitors at doses: captopril (88 and 176 mg/m(2)/day), enalapril (18, 24 and 36 mg/m(2)/day) and fosinopril (60 mg/m(2)/day) for mitigation. Our primary end point was survival or criteria for euthanization of morbid animals. Secondary end points included breathing intervals, other assays for lung structure and function and blood urea nitrogen (BUN) to assess renal damage. We found that captopril at 176 mg/m(2)/day increased survival after 11 or 11.5 Gy TBI. Enalapril at 18-36 mg/m(2)/day improved survival at all three doses (TBI). Fosinopril at 60 mg/m(2)/day enhanced survival at a dose of 11 Gy, although no improvement was observed for pneumonitis. These results demonstrate the use of a single countermeasure to mitigate the lethal late effects in the same animal after TBI.
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The Urine Proteome as a Radiation Biodosimeter. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 990:87-100. [DOI: 10.1007/978-94-007-5896-4_5] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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DiCarlo AL, Jackson IL, Shah JR, Czarniecki CW, Maidment BW, Williams JP. Development and licensure of medical countermeasures to treat lung damage resulting from a radiological or nuclear incident. Radiat Res 2012; 177:717-21. [PMID: 22468704 DOI: 10.1667/rr2881.1] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Due to the ever-present threat of a radiological or nuclear accident or attack, the National Institute of Allergy and Infectious Diseases, Radiation Medical Countermeasures Program was initiated in 2004. Since that time, the Program has funded research to establish small and large animal models for radiation damage, as well as the development of approaches to mitigate/treat normal tissue damage following radiation exposure. Because some of these exposures may be high-dose, and yet heterogeneous, the expectation is that some victims will survive initial acute radiation syndromes (e.g. hematopoietic and gastrointestinal), but then suffer from potentially lethal lung complications. For this reason, efforts have concentrated on the development of animal models of lung irradiation damage that mimic expected exposure scenarios, as well as drugs to treat radiation-induced late lung sequelae including pneumonitis and fibrosis. Approaches targeting several pathways are under study, with the eventual goal of licensure by the United States Food and Drug Administration for government stockpiling. This Commentary outlines the status of countermeasure development in this area and provides information on the specifics of licensure requirements, as well as guidance and a discussion of challenges involved in developing and licensing drugs and treatments specific to a radiation lung damage indication.
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Affiliation(s)
- Andrea L DiCarlo
- Division of Allergy, Immunology and Transplantation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA.
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Stewart FA, Akleyev AV, Hauer-Jensen M, Hendry JH, Kleiman NJ, Macvittie TJ, Aleman BM, Edgar AB, Mabuchi K, Muirhead CR, Shore RE, Wallace WH. ICRP publication 118: ICRP statement on tissue reactions and early and late effects of radiation in normal tissues and organs--threshold doses for tissue reactions in a radiation protection context. Ann ICRP 2012; 41:1-322. [PMID: 22925378 DOI: 10.1016/j.icrp.2012.02.001] [Citation(s) in RCA: 795] [Impact Index Per Article: 66.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
This report provides a review of early and late effects of radiation in normal tissues and organs with respect to radiation protection. It was instigated following a recommendation in Publication 103 (ICRP, 2007), and it provides updated estimates of 'practical' threshold doses for tissue injury defined at the level of 1% incidence. Estimates are given for morbidity and mortality endpoints in all organ systems following acute, fractionated, or chronic exposure. The organ systems comprise the haematopoietic, immune, reproductive, circulatory, respiratory, musculoskeletal, endocrine, and nervous systems; the digestive and urinary tracts; the skin; and the eye. Particular attention is paid to circulatory disease and cataracts because of recent evidence of higher incidences of injury than expected after lower doses; hence, threshold doses appear to be lower than previously considered. This is largely because of the increasing incidences with increasing times after exposure. In the context of protection, it is the threshold doses for very long follow-up times that are the most relevant for workers and the public; for example, the atomic bomb survivors with 40-50years of follow-up. Radiotherapy data generally apply for shorter follow-up times because of competing causes of death in cancer patients, and hence the risks of radiation-induced circulatory disease at those earlier times are lower. A variety of biological response modifiers have been used to help reduce late reactions in many tissues. These include antioxidants, radical scavengers, inhibitors of apoptosis, anti-inflammatory drugs, angiotensin-converting enzyme inhibitors, growth factors, and cytokines. In many cases, these give dose modification factors of 1.1-1.2, and in a few cases 1.5-2, indicating the potential for increasing threshold doses in known exposure cases. In contrast, there are agents that enhance radiation responses, notably other cytotoxic agents such as antimetabolites, alkylating agents, anti-angiogenic drugs, and antibiotics, as well as genetic and comorbidity factors. Most tissues show a sparing effect of dose fractionation, so that total doses for a given endpoint are higher if the dose is fractionated rather than when given as a single dose. However, for reactions manifesting very late after low total doses, particularly for cataracts and circulatory disease, it appears that the rate of dose delivery does not modify the low incidence. This implies that the injury in these cases and at these low dose levels is caused by single-hit irreparable-type events. For these two tissues, a threshold dose of 0.5Gy is proposed herein for practical purposes, irrespective of the rate of dose delivery, and future studies may elucidate this judgement further.
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Cohen EP, Bedi M, Irving AA, Jacobs E, Tomic R, Klein J, Lawton CA, Moulder JE. Mitigation of late renal and pulmonary injury after hematopoietic stem cell transplantation. Int J Radiat Oncol Biol Phys 2011; 83:292-6. [PMID: 22104363 DOI: 10.1016/j.ijrobp.2011.05.081] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2010] [Revised: 05/23/2011] [Accepted: 05/31/2011] [Indexed: 11/18/2022]
Abstract
PURPOSE To update the results of a clinical trial that assessed whether the angiotensin-converting enzyme inhibitor captopril was effective in mitigating chronic renal failure and pulmonary-related mortality in subjects undergoing total body irradiation (TBI) in preparation for hematopoietic stem cell transplantation (HSCT). METHODS AND MATERIALS Updated records of the 55 subjects who were enrolled in this randomized controlled trial were analyzed. Twenty-eight patients received captopril, and 27 patients received placebo. Definitions of TBI-HSCT-related chronic renal failure (and relapse) were the same as those in the 2007 analysis. Pulmonary-related mortality was based on clinical or autopsy findings of pulmonary failure or infection as the primary cause of death. Follow-up data for overall and pulmonary-related mortality were supplemented by use of the National Death Index. RESULTS The risk of TBI-HSCT-related chronic renal failure was lower in the captopril group (11% at 4 years) than in the placebo group (17% at 4 years), but this was not statistically significant (p > 0.2). Analysis of mortality was greatly extended by use of the National Death Index, and no patients were lost to follow-up for reasons other than death prior to 67 months. Patient survival was higher in the captopril group than in the placebo group, but this was not statistically significant (p > 0.2). The improvement in survival was influenced more by a decrease in pulmonary mortality (11% risk at 4 years in the captopril group vs. 26% in the placebo group, p = 0.15) than by a decrease in chronic renal failure. There was no adverse effect on relapse risk (p = 0.4). CONCLUSIONS Captopril therapy produces no detectable adverse effects when given after TBI. Captopril therapy reduces overall and pulmonary-related mortality after radiation-based HSCT, and there is a trend toward mitigation of chronic renal failure.
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Affiliation(s)
- Eric P Cohen
- Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.
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Abstract
Radiation leaves a fairly characteristic footprint in biological materials, but this is rapidly all but obliterated by the canonical biological responses to the radiation damage. The innate immune recognition systems that sense "danger" through direct radiation damage and through associated collateral damage set in motion a chain of events that, in a tissue compromised by radiation, often unwittingly result in oscillating waves of molecular and cellular responses as tissues attempt to heal. Understanding "nature's whispers" that inform on these processes will lead to novel forms of intervention targeted more precisely towards modifying them in an appropriate and timely fashion so as to improve the healing process and prevent or mitigate the development of acute and late effects of normal tissue radiation damage, whether it be accidental, as a result of a terrorist incident, or of therapeutic treatment of cancer. Here we attempt to discuss some of the non-free radical scavenging mechanisms that modify radiation responses and comment on where we see them within a conceptual framework of an evolving radiation-induced lesion.
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Affiliation(s)
- Kwanghee Kim
- Department of Radiation Oncology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California 90095, USA
| | - William H. McBride
- Department of Radiation Oncology, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California 90095, USA
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Moulder JE, Cohen EP, Fish BL. Captopril and losartan for mitigation of renal injury caused by single-dose total-body irradiation. Radiat Res 2010; 175:29-36. [PMID: 21175344 DOI: 10.1667/rr2400.1] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
It is known that angiotensin converting enzyme inhibitors (ACEIs) and angiotensin II type-1 receptor blockers (ARBs) can be used to mitigate radiation-induced renal injury. However, for a variety of reasons, these previous results are not directly applicable to the development of agents for the mitigation of injuries caused by terrorism-related radiation exposure. As part of an effort to develop an animal model that would fit the requirements of the U.S. Food and Drug Administration (FDA) "Animal Efficacy Rule", we designed new studies which used an FDA-approved ACEI (captopril) or an FDA-approved ARB (losartan, Cozaar®) started 10 days after a single total-body irradiation (TBI) at drug doses that are equivalent (on a g/m(2)/day basis) to the doses prescribed to humans. Captopril and losartan were equally effective as mitigators, with DMFs of 1.23 and 1.21, respectively, for delaying renal failure. These studies show that radiation nephropathy in a realistic rodent model can be mitigated with relevant doses of FDA-approved agents. This lays the necessary groundwork for pivotal rodent studies under the FDA Animal Efficacy Rule and provides an outline of how the FDA-required large-animal studies could be designed.
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Affiliation(s)
- John E Moulder
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA.
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Schuller BW, Rogers AB, Cormier KS, Riley KJ, Binns PJ, Julius R, Hawthorne MF, Coderre JA. No significant endothelial apoptosis in the radiation-induced gastrointestinal syndrome. Int J Radiat Oncol Biol Phys 2007; 68:205-10. [PMID: 17448874 DOI: 10.1016/j.ijrobp.2006.12.069] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2006] [Revised: 12/28/2006] [Accepted: 12/29/2006] [Indexed: 01/11/2023]
Abstract
PURPOSE This report addresses the incidence of vascular endothelial cell apoptosis in the mouse small intestine in relation to the radiation-induced gastrointestinal (GI) syndrome. METHODS AND MATERIALS Nonanesthetized mice received whole-body irradiation at doses above and below the threshold for death from the GI syndrome with 250 kVp X-rays, (137)Cs gamma rays, epithermal neutrons alone, or a unique approach for selective vascular irradiation using epithermal neutrons in combination with boronated liposomes that are restricted to the blood. Both terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL) staining for apoptosis and dual-fluorescence staining for apoptosis and endothelial cells were carried out in jejunal cross-sections at 4 h postirradiation. RESULTS Most apoptotic cells were in the crypt epithelium. The number of TUNEL-positive nuclei per villus was low (1.62 +/- 0.03, mean +/- SEM) for all irradiation modalities and showed no dose-response as a function of blood vessel dose, even as the dose crossed the threshold for death from the GI syndrome. Dual-fluorescence staining for apoptosis and endothelial cells verified the TUNEL results and identified the apoptotic nuclei in the villi as CD45-positive leukocytes. CONCLUSION These data do not support the hypothesis that vascular endothelial cell apoptosis is the cause of the GI syndrome.
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Affiliation(s)
- Bradley W Schuller
- Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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Moulder JE, Cohen EP. Future strategies for mitigation and treatment of chronic radiation-induced normal tissue injury. Semin Radiat Oncol 2007; 17:141-8. [PMID: 17395044 DOI: 10.1016/j.semradonc.2006.11.010] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Until the mid-1990s, radiation-induced normal-tissue injury was generally assumed to be solely caused by the delayed mitotic death of parenchymal or vascular cells, and these injuries were held to be progressive and untreatable. From this assumption, it followed that postirradiation interventions would be unlikely to reduce either the incidence or the severity of radiation-induced normal tissue injury. It is now clear that parenchymal and vascular cells are active participants in the response to radiation injury, an observation that allows for the possibility of pharmacologic mitigation and/or treatment of these injuries. Mitigation or treatment of chronic radiation injuries has now been experimentally shown in multiple organ systems (eg, lung, kidney, and brain), with different pharmacologic agents (eg, angiotensin-converting enzyme inhibitors, pentoxifylline, and superoxide dismutase mimetics) and with seemingly different mechanisms (eg, suppression of the renin-angiotensin system and suppression of chronic oxidative stress). Unfortunately, the mechanistic basis for most of the experimental successes has not been established, and assessment of the utility of these agents for clinical use has been slow. Clinical development of pharmacologic approaches to mitigation or treatment of chronic radiation injuries could lead to significant improvement in survival and quality of life for radiotherapy patients and for victims of radiation accidents or nuclear terrorism.
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Affiliation(s)
- John E Moulder
- Radiation Oncology and Medicine, Medical College of Wisconsin, Milwaukee, WI, USA.
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Shaw EG, Rosdhal R, D'Agostino RB, Lovato J, Naughton MJ, Robbins ME, Rapp SR. Phase II study of donepezil in irradiated brain tumor patients: effect on cognitive function, mood, and quality of life. J Clin Oncol 2006; 24:1415-20. [PMID: 16549835 DOI: 10.1200/jco.2005.03.3001] [Citation(s) in RCA: 204] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
PURPOSE A prospective, open-label phase II study was conducted to determine whether donepezil, a US Food and Drug Administration-approved reversible acetylcholinesterase inhibitor used to treat mild to moderate Alzheimer's type dementia, improved cognitive functioning, mood, and quality of life (QOL) in irradiated brain tumor patients. PATIENTS AND METHODS Thirty-four patients received donepezil 5 mg/d for 6 weeks, then 10 mg/d for 18 weeks, followed by a washout period of 6 weeks off drug. Outcomes were assessed at baseline, 12, 24 (end of treatment), and 30 weeks (end of wash-out). All tests were administered by a trained research nurse. RESULTS Of 35 patients who initiated the study, 24 patients (mean age, 45 years) remained on study for 24 weeks and completed all outcome assessments. All 24 patients had a primary brain tumor, mostly low-grade glioma. Scores significantly improved between baseline (pretreatment) and week 24 on measures of attention/concentration, verbal memory, and figural memory and a trend for verbal fluency (all P < .05). Confused mood also improved from baseline to 24 weeks (P = .004), with a trend for fatigue and anger (all P < .05). Health-related QOL improved significantly from baseline to 24 weeks, particularly, for brain specific concerns with a trend for improvement in emotional and social functioning (all P < .05). CONCLUSION Cognitive functioning, mood, and health-related QOL were significantly improved following a 24-week course of the acetylcholinesterase inhibitor donepezil. Toxicities were minimal. We are planning a double blinded, placebo-controlled, phase III trial of donepezil to confirm these favorable results.
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Affiliation(s)
- Edward G Shaw
- Department of Radiation Oncology, Wake Forest University School of Medicine, Brain Tumor Center of Excellence of WFU, Winston-Salem, NC 27157-1030, USA.
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Laurent C, Pouget JP, Voisin P. Modulation of DNA Damage by Pentoxifylline and α-Tocopherol in Skin Fibroblasts Exposed to Gamma Rays. Radiat Res 2005; 164:63-72. [PMID: 15966766 DOI: 10.1667/rr3383] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Previous in vivo studies showed the combination pentoxifylline (PTX) and alpha-tocopherol was highly efficient in reducing late radiation-induced skin damage. The present work aimed at investigating the molecular and cellular mechanisms involved in the effects of this combination. Primary cultures of confluent dermal fibroblasts were gamma-irradiated in the presence of PTX and trolox (Tx), the water-soluble analogue of alpha-tocopherol. Drugs were added either before or after radiation exposure and were maintained over time. Their antioxidant capacity and their effect on radiation-induced ROS production was assessed together with cell viability and clonogenicity. DNA damage formation was assessed by the alkaline comet assay and by the micronucleus (MN) test. Cell cycle distribution was also determined. The combination of PTX/ Tx was shown to reduce both immediate and late ROS formation observed in cells after irradiation. Surprisingly, decrease in DNA strand breaks measured by the comet assay was observed any time drugs were added. In addition, the micronucleus test revealed that for cells irradiated with 10 Gy, a late significant increase in MN formation occurred. The combination of PTX/Tx was shown to be antioxidant and to decrease radiation-induced ROS production. The observed effects on DNA damage at any time the drugs were added suggest that PTX/Tx could interfere with the DNA repair process.
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Affiliation(s)
- Carine Laurent
- Laboratoire de Dosimétrie Biologique, DRPH/SRBE, Institut de Radioprotection et de Sûreté Nucléaire, F-92262 Fontenay-aux-Roses, France
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Moulder JE, Cohen EP. Radiation-induced multi-organ involvement and failure: the contribution of radiation effects on the renal system. Br J Radiol 2005. [DOI: 10.1259/bjr/18309193] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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18
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Stone HB, Moulder JE, Coleman CN, Ang KK, Anscher MS, Barcellos-Hoff MH, Dynan WS, Fike JR, Grdina DJ, Greenberger JS, Hauer-Jensen M, Hill RP, Kolesnick RN, Macvittie TJ, Marks C, McBride WH, Metting N, Pellmar T, Purucker M, Robbins ME, Schiestl RH, Seed TM, Tomaszewski JE, Travis EL, Wallner PE, Wolpert M, Zaharevitz D. Models for Evaluating Agents Intended for the Prophylaxis, Mitigation and Treatment of Radiation Injuries Report of an NCI Workshop, December 3–4, 2003. Radiat Res 2004; 162:711-28. [PMID: 15548121 DOI: 10.1667/rr3276] [Citation(s) in RCA: 184] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
To develop approaches to prophylaxis/protection, mitigation and treatment of radiation injuries, appropriate models are needed that integrate the complex events that occur in the radiation-exposed organism. While the spectrum of agents in clinical use or preclinical development is limited, new research findings promise improvements in survival after whole-body irradiation and reductions in the risk of adverse effects of radiotherapy. Approaches include agents that act on the initial radiochemical events, agents that prevent or reduce progression of radiation damage, and agents that facilitate recovery from radiation injuries. While the mechanisms of action for most of the agents with known efficacy are yet to be fully determined, many seem to be operating at the tissue, organ or whole animal level as well as the cellular level. Thus research on prophylaxis/protection, mitigation and treatment of radiation injuries will require studies in whole animal models. Discovery, development and delivery of effective radiation modulators will also require collaboration among researchers in diverse fields such as radiation biology, inflammation, physiology, toxicology, immunology, tissue injury, drug development and radiation oncology. Additional investment in training more scientists in radiation biology and in the research portfolio addressing radiological and nuclear terrorism would benefit the general population in case of a radiological terrorism event or a large-scale accidental event as well as benefit patients treated with radiation.
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Affiliation(s)
- Helen B Stone
- National Cancer Institute, Bethesda, Maryland 20892, USA.
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19
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Kuin A, Kruse JJ, Stewart FA. Proteinuria and vascular changes after renal irradiation: the role of reactive oxygen species (ROS) and vascular endothelial growth factor (Vegf). Radiat Res 2003; 159:174-81. [PMID: 12537522 DOI: 10.1667/0033-7587(2003)159[0174:pavcar]2.0.co;2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Proteinuria occurs in all degrees of radiation nephropathy and can be present without other symptoms. In this study, radiation-induced proteinuria in C3H mice demonstrated a clear dose-response relationship and was apparent before the onset of significant structural vascular changes and decreases in renal function. This suggests that proteinuria is not a secondary event due to loss of the vascular structure. In an attempt to ameliorate radiation-induced proteinuria and progressive renal failure, two factors were studied. The influence of reactive oxygen species (ROS), which are generated by infiltrating neutrophils and mediate proteinuria in models of acute glomerular injury, was the first to be investigated. Short-term administration of the reactive oxygen scavengers superoxide dismutase (SOD) and catalase did not reverse an established radiation-induced proteinuria. Continuous administration of the antioxidant N-acetylcysteine (NAC) also failed to inhibit this proteinuria. However, since no direct assessment of the impact of these interventions on renal redox status was made, the putative role of ROS in radiation-induced proteinuria and nephropathy remains undefined. The second factor studied was vascular endothelial growth factor (Vegf), which is suggested to be involved in glomerular vessel permeability and the development of proteinuria in some models of renal disease. Northern blot analysis of mRNA from whole kidneys did not demonstrate any increased expression of Vegf after irradiation. There was also no change in the ratio of the different Vegf isoforms (PCR analysis), either in the whole kidney or in isolated glomeruli. No significant role for Vegf was identified for radiation-induced vascular changes or proteinuria, although post-transcriptional changes cannot be excluded.
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Affiliation(s)
- Annemieke Kuin
- Division of Experimental Therapy, The Netherlands Cancer Institute, Amsterdam, The Netherlands
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Abstract
Until the 1990s, chronic radiation-induced normal-tissue injury was viewed as being due solely to the delayed mitotic death of parenchymal or vascular cells; these injuries were held to be inevitable, progressive, and untreatable. It is now clear that parenchymal and vascular cells are active participants in the response to radiation injury rather than passive observers dying as they attempt to divide. This offers fundamentally new approaches to radiation injury because it allows for the possibility of pharmacological interventions directed at modulating steps in the cascade of events leading to expression of injury. Such interventions would be relevant to both cancer patients and victims of radiation accidents. Prophylaxis and treatment of chronic radiation injuries have been experimentally shown in multiple organ systems (eg, lung, kidney, soft tissue) and with fundamentally different pharmacological agents (eg, corticosteroids, angiotensin-converting enzyme inhibitors, pentoxifylline, superoxide dismutase). For the most part, this has been achieved using clinically relevant radiation and drug schedules and with agents that have already been approved for human use. Unfortunately, assessment of the utility of these agents for clinical use has been minimal, and there are no established mechanisms for any of the experimental or clinical successes. Clinical development of pharmacological approaches to modification of chronic radiation injuries could lead to significant improvement in survival and quality of life for radiotherapy patients and for victims of radiation accidents or nuclear terrorism.
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Affiliation(s)
- John E Moulder
- Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
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Cohen EP, Hussain S, Moulder JE. Successful treatment of radiation nephropathy with angiotensin II blockade. Int J Radiat Oncol Biol Phys 2003; 55:190-3. [PMID: 12504053 DOI: 10.1016/s0360-3016(02)03793-8] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
PURPOSE The aim of this report is to document the successful treatment of radiation nephropathy. METHODS Clinical case report with statistical analysis of evolution of kidney function. RESULTS A case of radiation nephropathy was found in a kidney transplant recipient whose kidney transplant had been irradiated with 750 cGy 23 years previously. Use of the angiotensin II blocker, losartan, was associated with significant stabilization of the kidney function. CONCLUSION Radiation nephropathy can be successfully treated. Other normal-tissue radiation injuries may also be treatable.
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Affiliation(s)
- Eric P Cohen
- Department of Medicine, Medical College of Wisconsin, Milwaukee, WI, USA.
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Moulder JE, Fish BL, Regner KR, Cohen EP. Angiotensin II blockade reduces radiation-induced proliferation in experimental radiation nephropathy. Radiat Res 2002; 157:393-401. [PMID: 11893241 DOI: 10.1667/0033-7587(2002)157[0393:aibrri]2.0.co;2] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Total-body irradiation or renal irradiation is followed by a well-defined sequence of changes in renal function leading eventually to renal failure. Previous studies in a rat model have shown that inhibition of angiotensin-converting enzyme or blockade of angiotensin II receptors can prevent the structural and functional changes that occur after renal irradiation, and that these interventions are particularly important between 3 and 10 weeks after irradiation. We have now shown that in the same rat model, total-body irradiation induces proliferation of renal tubular cells (i.e., an increase in the number of cells staining positive for proliferating cell nuclear antigen) within 5 weeks after irradiation. Treatment with an angiotensin II receptor blocker delays this radiation-induced tubular proliferation and decreases its magnitude. Renal radiation also induces proliferation of glomerular cells, but the relative increase in glomerular proliferation is not as great as that seen in renal tubular cells, and the increase is not delayed or decreased by treatment with an angiotensin II receptor blocker. We hypothesize that angiotensin II receptor blockers exert their beneficial effect in radiation nephropathy by delaying the proliferation (and hence the eventual mitotic death) of renal tubular cells that have been genetically crippled by radiation.
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Affiliation(s)
- John E Moulder
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA.
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Cohen EP, Fish BL, Moulder JE. The renin-angiotensin system in experimental radiation nephropathy. THE JOURNAL OF LABORATORY AND CLINICAL MEDICINE 2002; 139:251-7. [PMID: 12024113 DOI: 10.1067/mlc.2002.122279] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Irradiation of the kidneys is followed by a well-defined sequence of changes leading eventually to kidney failure. In the rat, inhibition of angiotensin-converting enzyme or blockade of angiotensin II receptors can prevent the structural and functional changes that occur after kidney irradiation. These interventions are particularly effective between 3 and 10 weeks after irradiation. However, in a series of studies with the rat model we failed to find any evidence that the renin-angiotensin system (RAS) is activated in the first 10 weeks after kidney irradiation. First, if the RAS was activated during this interval, one would expect hypertension followed by proteinuria and azotemia. However, hypertension is significant only at the end of this period and is preceded by significant proteinuria and azotemia. This evolution is not in favor of an obviously activated RAS during the 3- to 10-week postirradiation interval that is critical for interventions aimed at the RAS. Second, plasma renin activity and active plasma renin protein concentrations are not significantly increased over the first 10 weeks after irradiation. Third, whole-blood and intrarenal angiotensin II levels are not increased and may even be decreased over this interval. This last observation is particularly important because the assay used is sensitive enough to detect the effects of dietary salt manipulation. We hypothesize that even the normal activity of the RAS contributes to injury after kidney irradiation, possibly by supporting the proliferation of cells that carry potentially lethal radiation injuries.
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Affiliation(s)
- Eric P Cohen
- Department of Medicine, Division of Nephrology, Medical College of Wisconsin, Froedtert Memorial Lutheran Hospital, 9200 West Wisconsin Avenue, Milwaukee, WI 53226, USA.
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24
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Abstract
Studies have shown that angiotensin-converting enzyme inhibitors and an angiotensin II receptor blocker can delay, but cannot reverse, the progression of experimentally induced radiation nephropathy. In an effort to find a method for reversing injury, three agents were tested in a rat model of radiation nephropathy. Pirfenidone (a phenyl-pyridone antifibrotic) and thiaproline (an inhibitor of collagen deposition) were not capable of retarding the development of radiation nephropathy. However, all-trans retinoic acid (an anti-inflammatory agent) exacerbated radiation nephropathy. We speculated that the detrimental effects of retinoic acid might be the result of stimulation of renal cell proliferation. However, retinoic acid had no effect on tubular or glomerular cell proliferation in normal animals and did not enhance radiation-induced proliferation. A recent report that retinoic acids inhibit nitric oxide production suggested an alternative mechanism, since inhibition of production of nitric oxide is known to exacerbate radiation nephropathy. Experiments demonstrated that retinoic acid exacerbated the radiation-induced drop in renal production of nitric oxide, suggesting that the detrimental effect of all-trans retinoic acid might be explained by inhibition of renal nitric oxide activity. Particularly in view of the recent clinical report of enhancement of radiation nephropathy by retinoic acid in patients receiving bone marrow transplantation, the combination of retinoic acid and renal irradiation should be carried out with great caution.
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Affiliation(s)
- John E Moulder
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226, USA.
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26
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Hill RP, Rodemann HP, Hendry JH, Roberts SA, Anscher MS. Normal tissue radiobiology: from the laboratory to the clinic. Int J Radiat Oncol Biol Phys 2001; 49:353-65. [PMID: 11173128 DOI: 10.1016/s0360-3016(00)01484-x] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This manuscript is in four parts, presenting the four talks given in a symposium on normal tissue radiobiology. The first part addresses the general concept of the role of parenchymal cell radiosensitivity vs. other factors, highlighting research over the last decade that has altered our understanding of factors underlying normal tissue response. The other three parts expand on specific themes raised in the first part dealing in particular with (1) modifications of fibroblast response to irradiation in relation to the induction of tissue fibrosis, (2) the use of the linear-quadratic equation to model the potential benefits of using different means (both physical and biologic) of modifying normal tissue response, and (3) the specific role of the growth factor TFG-beta1 in normal tissue response to irradiation. The symposium highlights the complexities of the radiobiology of late normal tissue responses, yet provides evidence and ideas about how the clinical problem of such responses may be modified or alleviated.
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Affiliation(s)
- R P Hill
- Ontario Cancer Institute/Princess Margaret Hospital, Toronto, Ontario, Canada.
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Cohen EP, Bonsib SA, Whitehouse E, Hopewell JW, Robbins ME. Mediators and mechanisms of radiation nephropathy. PROCEEDINGS OF THE SOCIETY FOR EXPERIMENTAL BIOLOGY AND MEDICINE. SOCIETY FOR EXPERIMENTAL BIOLOGY AND MEDICINE (NEW YORK, N.Y.) 2000; 223:218-25. [PMID: 10654627 DOI: 10.1046/j.1525-1373.2000.22330.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Normal tissue radiation injury occurs after sufficient irradiation, thus limiting the curative potential of x-ray therapy. In the kidney, radiation injury results in fibrosis and, ultimately, renal failure. The mediators of fibrosis in radiation nephropathy have received scant attention. Therefore, we evaluated the sequential presence of alpha smooth muscle actin (alphasma), fibrin, collagen, and TGFbeta1 in a porcine model of radiation nephropathy using 9.8 Gy single-dose local kidney irradiation. During the 24-week study, there was progressive and significant collagen accumulation in glomeruli and in interstitium. In glomeruli, this was associated with significant mesangial alphasma expression by 2 weeks after irradiation, a further rise at 4 weeks, and then a gradual fall to baseline. Glomerular fibrin deposition was significant by 4 weeks after irradiation, and remained elevated thereafter. There was little or no glomerular TGFbeta1 expression at any time point. Tubular fibrin deposition was significant at 4 weeks after irradiation but declined thereafter. There was little or no tubulo-interstitial alphasma expression at any time after irradiation. At 6 weeks after irradiation, there was a significant peak of tubular epithelial TGFbeta1 expression that declined thereafter. The early glomerular injury is evident as mesangial alphasma expression but is not proceeded by TGFbeta1 expression. There is sustained glomerular fibrin deposition with deposition of fibrin in tubular lumens, suggesting that tubular fibrin derives and flows out from injured glomerular tufts. We conclude that i) alphasma expression is an early marker of glomerular radiation injury, presaging scarring; ii) fibrin deposition is involved in glomerular and tubular radiation injury; and iii) TGFbeta1 is not an early event in radiation nephropathy, and not apparent in glomeruli in this model, but may correlate with later tubulo-interstitial fibrosis. Thus, the mediators of scarring in this model differ according to time after injury and also according to the affected tissue compartment.
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Affiliation(s)
- E P Cohen
- Medical College of Wisconsin, Froedtert Memorial Lutheran Hospital, Milwaukee 53226, USA.
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Cohen EP, Fish BL, Moulder JE. Successful brief captopril treatment in experimental radiation nephropathy. THE JOURNAL OF LABORATORY AND CLINICAL MEDICINE 1997; 129:536-47. [PMID: 9142050 DOI: 10.1016/s0022-2143(97)90008-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Experimental renal irradiation is followed by a well-defined sequence of events leading to kidney failure. Inhibitors of angiotensin-converting enzyme can prevent the structural and functional changes that occur after renal irradiation, which suggests that the renin-angiotensin system plays a key role in their evolution. We therefore evaluated captopril, used for short intervals, in a total body irradiation model of radiation nephropathy. Irradiated 7- to 8-week-old rats that were treated with captopril from 3.5 to 9.5 weeks after irradiation had better kidney function and survival than irradiated animals treated at earlier or later intervals. At 26 weeks after irradiation, kidney function of these animals was similar to that of irradiated animals treated continuously with captopril, but their subsequent survival was less. Animals irradiated at 7 to 8 weeks of age and treated with captopril from 6 to 9 weeks after irradiation had better function and survival than animals treated at earlier or later intervals. Irradiated 15-week-old animals had significant functional and survival benefit from continuous captopril treatment but no protection from a 6-week interval of therapy. We conclude that radiation nephropathy may be significantly attenuated by the use of captopril from 3.5 to 9.5 weeks after irradiation in young animals. Although older animals did not appear to benefit from a short course of captopril, these data suggest that the renin-angiotensin system is important in the sequential expression of renal radiation injury, particularly between 3.5 and 9.5 weeks after irradiation.
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Affiliation(s)
- E P Cohen
- Department of Medicine, Medical College of Wisconsin, Milwaukee 53226, USA
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