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Zimmermann R, Roeder F, Ruppert C, Smith BJ, Knudsen L. Low-volume ventilation of preinjured lungs degrades lung function via stress concentration and progressive alveolar collapse. Am J Physiol Lung Cell Mol Physiol 2024; 327:L19-L39. [PMID: 38712429 DOI: 10.1152/ajplung.00323.2023] [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: 10/18/2023] [Revised: 03/27/2024] [Accepted: 04/22/2024] [Indexed: 05/08/2024] Open
Abstract
Mechanical ventilation can cause ventilation-induced lung injury (VILI). The concept of stress concentrations suggests that surfactant dysfunction-induced microatelectases might impose injurious stresses on adjacent, open alveoli and function as germinal centers for injury propagation. The aim of the present study was to quantify the histopathological pattern of VILI progression and to test the hypothesis that injury progresses at the interface between microatelectases and ventilated lung parenchyma during low-positive end-expiratory pressure (PEEP) ventilation. Bleomycin was used to induce lung injury with microatelectases in rats. Lungs were then mechanically ventilated for up to 6 h at PEEP = 1 cmH2O and compared with bleomycin-treated group ventilated protectively with PEEP = 5 cmH2O to minimize microatelectases. Lung mechanics were measured during ventilation. Afterward, lungs were fixed at end-inspiration or end-expiration for design-based stereology. Before VILI, bleomycin challenge reduced the number of open alveoli [N(alvair,par)] by 29%. No differences between end-inspiration and end-expiration were observed. Collapsed alveoli clustered in areas with a radius of up to 56 µm. After PEEP = 5 cmH2O ventilation for 6 h, N(alvair,par) remained stable while PEEP = 1 cmH2O ventilation led to an additional loss of aerated alveoli by 26%, mainly due to collapse, with a small fraction partly edema filled. Alveolar loss strongly correlated to worsening of tissue elastance, quasistatic compliance, and inspiratory capacity. The radius of areas of collapsed alveoli increased to 94 µm, suggesting growth of the microatelectases. These data provide evidence that alveoli become unstable in neighborhood of microatelectases, which most likely occurs due to stress concentration-induced local vascular leak and surfactant dysfunction.NEW & NOTEWORTHY Low-volume mechanical ventilation in the presence of high surface tension-induced microatelectases leads to the degradation of lung mechanical function via the progressive loss of alveoli. Microatelectases grow at the interfaces of collapsed and open alveoli. Here, stress concentrations might cause injury and alveolar instability. Accumulation of small amounts of alveolar edema can be found in a fraction of partly collapsed alveoli but, in this model, alveolar flooding is not a major driver for degradation of lung mechanics.
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Affiliation(s)
- Richard Zimmermann
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
| | - Franziska Roeder
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
| | - Clemens Ruppert
- Department of Internal Medicine, Justus-Liebig-University Giessen, Giessen, Germany
- University of Giessen and Marburg Lung Center (UGMLC), member of the German Center for Lung Research (DZL), Giessen, Germany
| | - Bradford J Smith
- Department of Bioengineering, College of Engineering, Design & Computing, University of Colorado Denver | Anschutz Medical Campus, Aurora, Colorado, United States
- Section of Pulmonary and Sleep Medicine, Department of Pediatrics, University of Colorado Denver, Anschutz Medical Campus, Aurora, Colorado, United States
| | - Lars Knudsen
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
- Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover Medical School, Hannover, Germany
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2
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McGinn EA, Bye E, Gonzalez T, Sosa A, Bilodeaux J, Seedorf G, Smith BJ, Abman SH, Mandell EW. Antenatal Endotoxin Induces Dysanapsis in Experimental Bronchopulmonary Dysplasia. Am J Respir Cell Mol Biol 2024; 70:283-294. [PMID: 38207120 DOI: 10.1165/rcmb.2023-0157oc] [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: 05/02/2023] [Accepted: 01/10/2024] [Indexed: 01/13/2024] Open
Abstract
Bronchopulmonary dysplasia (BPD), the chronic lung disease of prematurity, is characterized by impaired lung development with sustained functional abnormalities due to alterations of airways and the distal lung. Although clinical studies have shown striking associations between antenatal stress and BPD, little is known about the underlying pathogenetic mechanisms. Whether dysanapsis, the concept of discordant growth of the airways and parenchyma, contributes to late respiratory disease as a result of antenatal stress is unknown. We hypothesized that antenatal endotoxin (ETX) impairs juvenile lung function as a result of altered central airway and distal lung structure, suggesting the presence of dysanapsis in this preclinical BPD model. Fetal rats were exposed to intraamniotic ETX (10 μg) or saline solution (control) 2 days before term. We performed extensive structural and functional evaluation of the proximal airways and distal lung in 2-week-old rats. Distal lung structure was quantified by stereology. Conducting airway diameters were measured using micro-computed tomography. Lung function was assessed during invasive ventilation to quantify baseline mechanics, response to methacholine challenge, and spirometry. ETX-exposed pups exhibited distal lung simplification, decreased alveolar surface area, and decreased parenchyma-airway attachments. ETX-exposed pups exhibited decreased tracheal and second- and third-generation airway diameters. ETX increased respiratory system resistance and decreased lung compliance at baseline. Only Newtonian resistance, specific to large airways, exhibited increased methacholine reactivity in ETX-exposed pups compared with controls. ETX-exposed pups had a decreased ratio of FEV in 0.1 second to FVC and a normal FEV in 0.1 second, paralleling the clinical definition of dysanapsis. Antenatal ETX causes abnormalities of the central airways and distal lung growth, suggesting that dysanapsis contributes to abnormal lung function in juvenile rats.
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Affiliation(s)
- Elizabeth A McGinn
- Pediatric Heart Lung Center, Department of Pediatrics
- Department of Pediatric Critical Care Medicine
| | - Elisa Bye
- Pediatric Heart Lung Center, Department of Pediatrics
| | | | - Alexander Sosa
- Department of Bioengineering, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Jill Bilodeaux
- Department of Bioengineering, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | | | - Bradford J Smith
- Pediatric Heart Lung Center, Department of Pediatrics
- Department of Pediatric Pulmonary and Sleep Medicine, and
- Department of Bioengineering, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Steven H Abman
- Pediatric Heart Lung Center, Department of Pediatrics
- Department of Pediatric Pulmonary and Sleep Medicine, and
| | - Erica W Mandell
- Pediatric Heart Lung Center, Department of Pediatrics
- Department of Neonatology, University of Colorado School of Medicine, Aurora, Colorado; and
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3
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Ferner K. Development of the terminal air spaces in the gray short-tailed opossum (Monodelphis domestica)- 3D reconstruction by microcomputed tomography. PLoS One 2024; 19:e0292482. [PMID: 38363783 PMCID: PMC10871483 DOI: 10.1371/journal.pone.0292482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 01/13/2024] [Indexed: 02/18/2024] Open
Abstract
Marsupials are born with structurally immature lungs when compared to eutherian mammals. The gray short-tailed opossum (Monodelphis domestica) is born at the late canalicular stage of lung development. Despite the high degree of immaturity, the lung is functioning as respiratory organ, however supported by the skin for gas exchange during the first postnatal days. Consequently, the majority of lung development takes place in ventilated functioning state during the postnatal period. Microcomputed tomography (μCT) was used to three-dimensionally reconstruct the terminal air spaces in order to reveal the timeline of lung morphogenesis. In addition, lung and air space volume as well as surface area were determined to assess the functional relevance of the structural changes in the developing lung. The development of the terminal air spaces was examined in 35 animals from embryonic day 13, during the postnatal period (neonate to 57 days) and in adults. At birth, the lung of Monodelphis domestica consists of few large terminal air spaces, which are poorly subdivided and open directly from short lobar bronchioles. During the first postnatal week the number of smaller terminal air spaces increases and numerous septal ridges indicate a process of subdivision, attaining the saccular stage by 7 postnatal days. The 3D reconstructions of the terminal air spaces demonstrated massive increases in air sac number and architectural complexity during the postnatal period. Between 28 and 35 postnatal days alveolarization started. Respiratory bronchioles, alveolar ducts and a typical acinus developed. The volume of the air spaces and the surface area for gas exchange increased markedly with alveolarization. The structural transformation from large terminal sacs to the final alveolar lung in the gray short-tailed opossum follows similar patterns as described in other marsupial and placental mammals. The processes involved in sacculation and alveolarization during lung development seem to be highly conservative within mammalian evolution.
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Affiliation(s)
- Kirsten Ferner
- Department Evolutionary Morphology, Leibniz-Institut für Evolutions- und Biodiversitätsforschung, Museum für Naturkunde, Berlin, Germany
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4
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Ferner K, Mahlow K. 3D reconstruction of the bronchial tree of the Gray short-tailed opossum (Monodelphis domestica) in the postnatal period. J Anat 2023; 243:910-935. [PMID: 37497834 PMCID: PMC10641052 DOI: 10.1111/joa.13928] [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: 05/12/2023] [Revised: 06/30/2023] [Accepted: 06/30/2023] [Indexed: 07/28/2023] Open
Abstract
Recent didelphid marsupials resemble the assumed mammalian ancestor and are suitable to inform on the evolution of the mammalian lung. This study uses X-ray computed tomography (μCT) to three-dimensionally reconstruct the bronchial tree of the marsupial Gray short-tailed opossum (Monodelphis domestica) in order to reveal the timeline of morphogenesis during the postnatal period. The development of the bronchial tree was examined in 37 animals from embryonic day 13, during the postnatal period (neonate to 57 days) and in adults. The first appearance and the branching of lobar, segmental and sub-segmental bronchioles in the lungs were documented. Based on the reconstructions, the generation of end-branching airways, the median and maximum generation and the number of branches were calculated for each pulmonary lobe. At birth, the lung of M. domestica has a primitive appearance since it consists of a simple system of branching airways that end in a number of terminal air spaces, lobar bronchioles, and first segmental bronchioles are present. During the postnatal period, the volumes of the lung and bronchial tree steadily increase and development, differentiation, and expansion of the bronchial tree takes place. By 14 days, the fundamental bronchial tree consisting of lobar, segmental, and sub-segmental bronchioles has been established. A mature bronchial tree, including respiratory bronchioles and alveolar ducts is present by day 35. The asymmetry of the right (predominately four lobes) and the left lung (predominately two lobes), as present in M. domestica, can be considered as plesiomorphic for Mammalia. In marsupials, the process of branching morphogenesis, which takes place intrauterine in the placental fetus, is shifted to the postnatal period, but follows similar patterns as described in placentals. Lung maturation in general and the branching morphogenesis in particular seems to be highly conservative within mammalian evolution.
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Affiliation(s)
- Kirsten Ferner
- Museum für Naturkunde, Leibniz‐Institut für Evolutions‐ und BiodiversitätsforschungBerlinGermany
| | - Kristin Mahlow
- Museum für Naturkunde, Leibniz‐Institut für Evolutions‐ und BiodiversitätsforschungBerlinGermany
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5
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Kim MW, Weon BM, Je JH. Spherical alveolar shapes in live mouse lungs. Sci Rep 2023; 13:5319. [PMID: 37002270 PMCID: PMC10066015 DOI: 10.1038/s41598-023-32254-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 03/24/2023] [Indexed: 04/03/2023] Open
Abstract
Understanding how the alveolar mechanics work in live lungs is essential for comprehending how the lung behaves during breathing. Due to the lack of appropriate imaging tools, previous research has suggested that alveolar morphologies are polyhedral rather than spherical based on a 2D examination of alveoli in fixed lungs. Here, we directly observe high-resolution 3D alveoli in live mice lungs utilizing synchrotron x-ray microtomography to show spherical alveolar morphologies from the live lungs. Our measurements from x-ray microtomography show high sphericity, low packing density, big alveolar size, and low osmotic pressure, indicating that spherical alveolar morphologies are natural in living lungs. The alveolar packing fraction is quite low in live lungs, where the spherical alveoli would behave like free bubbles, while the confinement of alveolar clusters in fixed lungs would lead to significant morphological deformations of the alveoli appearing polyhedral. Direct observations of the spherical alveolar shapes will help understand and treat lung disease and ventilation.
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Affiliation(s)
- Min Woo Kim
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, San 31, Hyojadong, Pohang, 37673, South Korea
| | - Byung Mook Weon
- Soft Matter Physics Laboratory, School of Advanced Materials Science and Engineering, SKKU Advanced Institute of Nanotechnology (SAINT), Sungkyunkwan University, Suwon, 16419, South Korea.
- Research Center for Advanced Materials Technology, Core Research Institute, Suwon, 16419, South Korea.
| | - Jung Ho Je
- Department of Materials Science and Engineering, Pohang University of Science and Technology, San 31, Hyoja-Dong, Pohang, 37673, South Korea.
- Nanoblesse Research Lab., Nanoblesse, 4Th Fl. 85-11, Namwon-Ro, Pohang, 37883, South Korea.
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6
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Redente EF, Kopf KW, Bahadur AN, Robichaud A, Lundblad LK, McDonald LT. Application-specific approaches to MicroCT for evaluation of mouse models of pulmonary disease. PLoS One 2023; 18:e0281452. [PMID: 36757935 PMCID: PMC9910664 DOI: 10.1371/journal.pone.0281452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 01/23/2023] [Indexed: 02/10/2023] Open
Abstract
The advent of micro-computed tomography (microCT) has provided significant advancement in our ability to generate clinically relevant assessments of lung health and disease in small animal models. As microCT use to generate outcomes analysis in pulmonary preclinical models has increased there have been substantial improvements in image quality and resolution, and data analysis software. However, there are limited published methods for standardized imaging and automated analysis available for investigators. Manual quantitative analysis of microCT images is complicated by the presence of inflammation and parenchymal disease. To improve the efficiency and limit user-associated bias, we have developed an automated pulmonary air and tissue segmentation (PATS) task list to segment lung air volume and lung tissue volume for quantitative analysis. We demonstrate the effective use of the PATS task list using four distinct methods for imaging, 1) in vivo respiration controlled scanning using a flexiVent, 2) longitudinal breath-gated in vivo scanning in resolving and non-resolving pulmonary disease initiated by lipopolysaccharide-, bleomycin-, and silica-exposure, 3) post-mortem imaging, and 4) ex vivo high-resolution scanning. The accuracy of the PATS task list was compared to manual segmentation. The use of these imaging techniques and automated quantification methodology across multiple models of lung injury and fibrosis demonstrates the broad applicability and adaptability of microCT to various lung diseases and small animal models and presents a significant advance in efficiency and standardization of preclinical microCT imaging and analysis for the field of pulmonary research.
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Affiliation(s)
- Elizabeth F. Redente
- Department of Pediatrics, National Jewish Health, Denver, Colorado, United States of America
- Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
- * E-mail:
| | - Katrina W. Kopf
- Department of Academic Affairs, National Jewish Health, Denver, Colorado, United States of America
| | - Ali N. Bahadur
- Bruker BioSpin Corporation, Billerica, Massachusetts, United States of America
| | | | | | - Lindsay T. McDonald
- Ralph H. Johnson VA Medical Center, Charleston, South Carolina, United States of America
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7
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Shankar SS, Felice N, Hoffman EA, Atha J, Sieren JC, Samei E, Abadi E. Task-based validation and application of a scanner-specific CT simulator using an anthropomorphic phantom. Med Phys 2022; 49:7447-7457. [PMID: 36097259 PMCID: PMC9792443 DOI: 10.1002/mp.15967] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 08/23/2022] [Accepted: 08/24/2022] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND Quantitative analysis of computed tomography (CT) images traditionally utilizes real patient data that can pose challenges with replicability, efficiency, and radiation exposure. Instead, virtual imaging trials (VITs) can overcome these hurdles through computer simulations of models of patients and imaging systems. DukeSim is a scanner-specific CT imaging simulator that has previously been validated with simple cylindrical phantoms, but not with anthropomorphic conditions and clinically relevant measurements. PURPOSE To validate a scanner-specific CT simulator (DukeSim) for the assessment of lung imaging biomarkers under clinically relevant conditions across multiple scanners using an anthropomorphic chest phantom, and to demonstrate the utility of virtual trials by studying the effects or radiation dose and reconstruction kernels on the lung imaging quantifications. METHODS An anthropomorphic chest phantom with customized tube inserts was imaged with two commercial scanners (Siemens Force and Siemens Flash) at 28 dose and reconstruction conditions. A computational version of the chest phantom was used with a scanner-specific CT simulator (DukeSim) to simulate virtual images corresponding to the settings of the real acquisitions. Lung imaging biomarkers were computed from both real and simulated CT images and quantitatively compared across all imaging conditions. The VIT framework was further utilized to investigate the effects of radiation dose (20-300 mAs) and reconstruction settings (Qr32f, Qr40f, and Qr69f reconstruction kernels using ADMIRE strength 3) on the accuracy of lung imaging biomarkers, compared against the ground-truth values modeled in the computational chest phantom. RESULTS The simulated CT images matched closely the real images for both scanners and all imaging conditions qualitatively and quantitatively, with the average biomarker percent error of 3.51% (range 0.002%-18.91%). The VIT study showed that sharper reconstruction kernels had lower accuracy with errors in mean lung HU of 84-94 HU, lung volume of 797-3785 cm3 , and lung mass of -800 to 1751 g. Lower tube currents had the lower accuracy with errors in mean lung HU of 6-84 HU, lung volume of 66-3785 cm3 , and lung mass of 170-1751 g. Other imaging biomarkers were consistent under the studied reconstruction settings and tube currents. CONCLUSION We comprehensively evaluated the realism of DukeSim in an anthropomorphic setup across a diverse range of imaging conditions. This study paves the way toward utilizing VITs more reliably for conducting medical imaging experiments that are not practical using actual patient images.
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Affiliation(s)
- Sachin S. Shankar
- Center for Virtual Imaging Trials, Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University
- Department of Electrical and Computer Engineering, Duke University
| | - Nicholas Felice
- Center for Virtual Imaging Trials, Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University
| | - Eric A. Hoffman
- Department of Radiology, University of Iowa
- Department of Biomedical Engineering, University of Iowa
| | | | - Jessica C. Sieren
- Department of Radiology, University of Iowa
- Department of Biomedical Engineering, University of Iowa
| | - Ehsan Samei
- Center for Virtual Imaging Trials, Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University
- Department of Electrical and Computer Engineering, Duke University
| | - Ehsan Abadi
- Center for Virtual Imaging Trials, Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University
- Department of Electrical and Computer Engineering, Duke University
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8
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Hoffman EA. Origins of and lessons from quantitative functional X-ray computed tomography of the lung. Br J Radiol 2022; 95:20211364. [PMID: 35193364 PMCID: PMC9153696 DOI: 10.1259/bjr.20211364] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 01/20/2022] [Accepted: 01/27/2022] [Indexed: 12/16/2022] Open
Abstract
Functional CT of the lung has emerged from quantitative CT (qCT). Structural details extracted at multiple lung volumes offer indices of function. Additionally, single volumetric images, if acquired at standardized lung volumes and body posture, can be used to model function by employing such engineering techniques as computational fluid dynamics. With the emergence of multispectral CT imaging including dual energy from energy integrating CT scanners and multienergy binning using the newly released photon counting CT technology, function is tagged via use of contrast agents. Lung disease phenotypes have previously been lumped together by the limitations of spirometry and plethysmography. QCT and its functional embodiment have been imbedded into studies seeking to characterize chronic obstructive pulmonary disease, severe asthma, interstitial lung disease and more. Reductions in radiation dose by an order of magnitude or more have been achieved. At the same time, we have seen significant increases in spatial and density resolution along with methodologic validations of extracted metrics. Together, these have allowed attention to turn towards more mild forms of disease and younger populations. In early applications, clinical CT offered anatomic details of the lung. Functional CT offers regional measures of lung mechanics, the assessment of functional small airways disease, as well as regional ventilation-perfusion matching (V/Q) and more. This paper will focus on the use of quantitative/functional CT for the non-invasive exploration of dynamic three-dimensional functioning of the breathing lung and beating heart within the unique negative pressure intrathoracic environment of the closed chest.
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Affiliation(s)
- Eric A Hoffman
- Departments of Radiology, Internal Medicine and Biomedical Engineering University of Iowa, Iowa, United States
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9
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Zhu L, Duerr J, Zhou-Suckow Z, Wagner WL, Weinheimer O, Salomon JJ, Leitz D, Konietzke P, Yu H, Ackermann M, Stiller W, Kauczor HU, Mall MA, Wielpütz MO. µCT to quantify muco-obstructive lung disease and effects of neutrophil elastase knockout in mice. Am J Physiol Lung Cell Mol Physiol 2022; 322:L401-L411. [PMID: 35080183 DOI: 10.1152/ajplung.00341.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Muco-obstructive lung diseases are characterized by airway obstruction and hyperinflation, which can be quantified by imaging. Our aim was to evaluate µCT for longitudinal quantification of muco-obstructive lung disease in β-epithelial Na+ channel overexpressing (Scnn1b-TG) mice and of the effects of neutrophil elastase (NE) knockout on its progression. Lungs from wild-type (WT), NE-/-, Scnn1b-TG, and Scnn1b-TG/NE-/- mice were scanned with 9 µm resolution at 0, 5, 14 and 60 days of age, and airway and parenchymal disease was quantified. Mucus adhesion lesions (MAL) were persistently increased in Scnn1b-TG compared to WT mice from 0 days (20.25±6.50 vs. 9.60±2.07, P<0.05), and this effect was attenuated in Scnn1b-TG/NE-/- mice (5.33±3.67, P<0.001). Airway wall area percentage (WA%) was increased in Scnn1b-TG mice compared to WT from 14 days onward (59.2±6.3% vs. 49.8±9.0%, P<0.001) but was similar in Scnn1b-TG/NE-/- compared to WT at 60 days (46.4±9.2% vs. 45.4±11.5%, P=0.97). Air proportion (Air%) and mean linear intercept (Lm) were persistently increased in Scnn1b-TG compared to WT from 5 days on (53.9±4.5% vs. 30.0±5.5% and 78.82±8.44µm vs. 65.66±4.15µm, respectively, P<0.001), whereas in Scnn1b-TG/NE-/- Air% and Lm were similar to WT from birth (27.7±5.5% vs.27.2±5.9%, P =0.92 and 61.48±9.20µm vs. 61.70±6.73µm, P=0.93, respectively). Our results suggest that µCT is sensitive to detect the onset and progression of muco-obstructive lung disease and effects of genetic deletion of NE on morphology of airways and lung parenchyma in Scnn1b-TG mice, and that it may serve as a sensitive endpoint for preclinical studies of novel therapeutic interventions for muco-obstructive lung diseases.
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Affiliation(s)
- Lin Zhu
- Department of Diagnostic and Interventional Radiology, University Hospital of Heidelberg, Heidelberg, Germany.,Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), Heidelberg, Germany.,Department of Diagnostic and Interventional Radiology with Nuclear Medicine, Thoraxklinik at the University Hospital of Heidelberg, Heidelberg, Germany
| | - Julia Duerr
- Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), Heidelberg, Germany.,Department of Translational Pulmonology, University Hospital Heidelberg, Heidelberg, Germany.,Department of Pediatric Respiratory Medicine, Immunology and Critical Care Medicine, Charité-Universitätsmedizin Berlin, Berlin, Germany.,German Center for Lung Research (DZL), associated partner Berlin, Germany
| | - Zhe Zhou-Suckow
- Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), Heidelberg, Germany.,Department of Translational Pulmonology, University Hospital Heidelberg, Heidelberg, Germany
| | - Willi L Wagner
- Department of Diagnostic and Interventional Radiology, University Hospital of Heidelberg, Heidelberg, Germany.,Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), Heidelberg, Germany.,Department of Diagnostic and Interventional Radiology with Nuclear Medicine, Thoraxklinik at the University Hospital of Heidelberg, Heidelberg, Germany
| | - Oliver Weinheimer
- Department of Diagnostic and Interventional Radiology, University Hospital of Heidelberg, Heidelberg, Germany.,Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), Heidelberg, Germany.,Department of Diagnostic and Interventional Radiology with Nuclear Medicine, Thoraxklinik at the University Hospital of Heidelberg, Heidelberg, Germany
| | - Johanna Jessica Salomon
- Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), Heidelberg, Germany.,Department of Translational Pulmonology, University Hospital Heidelberg, Heidelberg, Germany
| | - Dominik Leitz
- Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), Heidelberg, Germany.,Department of Translational Pulmonology, University Hospital Heidelberg, Heidelberg, Germany.,Department of Pediatric Respiratory Medicine, Immunology and Critical Care Medicine, Charité-Universitätsmedizin Berlin, Berlin, Germany.,German Center for Lung Research (DZL), associated partner Berlin, Germany
| | - Philip Konietzke
- Department of Diagnostic and Interventional Radiology, University Hospital of Heidelberg, Heidelberg, Germany.,Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), Heidelberg, Germany.,Department of Diagnostic and Interventional Radiology with Nuclear Medicine, Thoraxklinik at the University Hospital of Heidelberg, Heidelberg, Germany
| | - Hong Yu
- Department of Radiology, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Maximilian Ackermann
- Institute of Functional and Clinical Anatomy, University Medical Center of the Johannes Gutenberg-University Mainz, Mainz, Germany.,Institute of Pathology and Department of Molecular Pathology, Helios University Clinic Wuppertal, University of Witten-Herdecke, Wuppertal, Germany
| | - Wolfram Stiller
- Department of Diagnostic and Interventional Radiology, University Hospital of Heidelberg, Heidelberg, Germany.,Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), Heidelberg, Germany
| | - Hans-Ulrich Kauczor
- Department of Diagnostic and Interventional Radiology, University Hospital of Heidelberg, Heidelberg, Germany.,Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), Heidelberg, Germany.,Department of Diagnostic and Interventional Radiology with Nuclear Medicine, Thoraxklinik at the University Hospital of Heidelberg, Heidelberg, Germany
| | - Marcus A Mall
- Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), Heidelberg, Germany.,Department of Translational Pulmonology, University Hospital Heidelberg, Heidelberg, Germany.,Department of Pediatric Respiratory Medicine, Immunology and Critical Care Medicine, Charité-Universitätsmedizin Berlin, Berlin, Germany.,German Center for Lung Research (DZL), associated partner Berlin, Germany.,Berlin Institute of Health (BIH), Berlin, Germany
| | - Mark Oliver Wielpütz
- Department of Diagnostic and Interventional Radiology, University Hospital of Heidelberg, Heidelberg, Germany.,Translational Lung Research Center Heidelberg (TLRC), German Center for Lung Research (DZL), Heidelberg, Germany.,Department of Diagnostic and Interventional Radiology with Nuclear Medicine, Thoraxklinik at the University Hospital of Heidelberg, Heidelberg, Germany
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10
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Sarabia-Vallejos MA, Ayala-Jeria P, Hurtado DE. Three-Dimensional Whole-Organ Characterization of the Regional Alveolar Morphology in Normal Murine Lungs. Front Physiol 2021; 12:755468. [PMID: 34955878 PMCID: PMC8692792 DOI: 10.3389/fphys.2021.755468] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Accepted: 11/15/2021] [Indexed: 11/18/2022] Open
Abstract
Alveolar architecture plays a fundamental role in the processes of ventilation and perfusion in the lung. Alterations in the alveolar surface area and alveolar cavity volume constitute the pathophysiological basis of chronic respiratory diseases such as pulmonary emphysema. Previous studies based on micro-computed tomography (micro-CT) of lung samples have allowed the geometrical study of acinar units. However, our current knowledge is based on the study of a few tissue samples in random locations of the lung that do not give an account of the spatial distributions of the alveolar architecture in the whole lung. In this work, we combine micro-CT imaging and computational geometry algorithms to study the regional distribution of key morphological parameters throughout the whole lung. To this end, 3D whole-lung images of Sprague–Dawley rats are acquired using high-resolution micro-CT imaging and analyzed to estimate porosity, alveolar surface density, and surface-to-volume ratio. We assess the effect of current gold-standard dehydration methods in the preparation of lung samples and propose a fixation protocol that includes the application of a methanol-PBS solution before dehydration. Our results show that regional porosity, alveolar surface density, and surface-to-volume ratio have a uniform distribution in normal lungs, which do not seem to be affected by gravitational effects. We further show that sample fixation based on ethanol baths for dehydration introduces shrinking and affects the acinar architecture in the subpleural regions. In contrast, preparations based on the proposed dehydration protocol effectively preserve the alveolar morphology.
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Affiliation(s)
| | - Pedro Ayala-Jeria
- Department of Respiratory Diseases, School of Medicine, Center of Medical Research, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Daniel E Hurtado
- Department of Structural and Geotechnical Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile.,Schools of Engineering, Medicine and Biological Sciences, Institute for Biological and Medical Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile.,Millennium Nucleus for Cardiovascular Magnetic Resonance, Santiago, Chile
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11
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Liu QP, Ge P, Wang QN, Zhang SY, Yang YQ, Lv MQ, Lu Y, Li MX, Zhou DX. Circular RNA-CDR1as is involved in lung injury induced by long-term formaldehyde inhalation. Inhal Toxicol 2021; 33:325-333. [PMID: 34752207 DOI: 10.1080/08958378.2021.1999350] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
OBJECTIVE Formaldehyde (FA) is known to induce lung injury, but the underlying molecular mechanism remains largely unclear. CDR1as is an important member of the circular RNAs (circRNAs) family and functions as miRNA sponges with gene-regulatory potential. Our earlier circRNA microarray data showed CDR1as was highly expressed in lung tissue exposed to FA. However, the mechanism of circRNA-CDR1as mediates the FA-exposed lung injury is still unclear. This study aimed to explore the role of CDR1as in lung injury. MATERIALS AND METHODS In this study, FA was inhaled at doses of 0.5, 2.46, and 5 mg/m3, respectively. After exposure 8 weeks, lung histopathological examination, lung injury score, and IL-1β in bronchoalveolar lavage fluid (BALF) were determined. The expressions of CDR1as, rno-miR-7b and Atg7 were detected and the potential interaction of circRNA/miRNA/mRNA was predicted by bioinformatics analysis, including drawing circRNA/miRNA/mRNA interaction network, GO and KEGG analysis. RESULTS Our results indicated FA inhalation upregulated the expression of CDR1as in lung tissues in a dose-dependent manner while the expression of rno-miR-7b decreased and Atg7 increased. Moreover, the alteration of CDR1as was positively correlated with lung injury. DISCUSSION AND CONCLUSIONS CircRNA/miRNA/mRNA prediction further explained the possible effect mechanisms of CDR1as. These data implicated that CDR1as might be a critical regulator involved in lung injury induced by FA.
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Affiliation(s)
- Qiu-Ping Liu
- Department of Pathology, Medical School, Xi'an Jiaotong University, Xi'an, China.,Respiratory Department, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China.,Xi'an People's Hospital (Xi'an Fourth Hospital), Xi'an, China
| | - Pan Ge
- Department of Pathology, Medical School, Xi'an Jiaotong University, Xi'an, China.,Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education of China, Xi'an Jiaotong University, Xi'an, China
| | - Qian-Nan Wang
- Qide College, Xi'an Jiaotong University, Xi'an, China
| | - Shu-Yu Zhang
- Zonglian College, Xi'an Jiaotong University, Xi'an, China
| | - Yan-Qi Yang
- Department of Pathology, Medical School, Xi'an Jiaotong University, Xi'an, China.,Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education of China, Xi'an Jiaotong University, Xi'an, China
| | - Mo-Qi Lv
- Department of Pathology, Medical School, Xi'an Jiaotong University, Xi'an, China.,Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education of China, Xi'an Jiaotong University, Xi'an, China
| | - Ye Lu
- Xi'an People's Hospital (Xi'an Fourth Hospital), Xi'an, China
| | - Man-Xiang Li
- Respiratory Department, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Dang-Xia Zhou
- Department of Pathology, Medical School, Xi'an Jiaotong University, Xi'an, China.,Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education of China, Xi'an Jiaotong University, Xi'an, China
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12
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Jung JW, Oh JS, Bae B, Ahn YH, Kim LW, Choi J, Kim HY, Kang HR, Lee CH. Ultra-high-resolution computed tomography shows changes in the lungs related with airway hyperresponsiveness in a murine asthma model. Sci Rep 2021; 11:17584. [PMID: 34475448 PMCID: PMC8413288 DOI: 10.1038/s41598-021-96853-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 08/09/2021] [Indexed: 11/12/2022] Open
Abstract
In vivo presentation of airway hyper-responsiveness (AHR) at the different time points of the allergic reaction is not clearly understood. The purpose of this study was to investigate how AHR manifests in the airway and the lung parenchyma in vivo following exposure to different stimuli and in the early and late phases of asthma after allergen exposure. Ovalbumin (OVA)-induced allergic asthma model was established using 6-week female BALB/c mice. Enhanced pause was measured with a non-invasive method to assess AHR. The dynamic changes of the airway and lung parenchyma were evaluated with ultra-high-resolution computed tomography (128 multi-detector, 1024 × 1024 matrix) for 10 h. While the methacholine challenge showed no grossly visible changes in the proximal airway and lung parenchyma despite provoking AHR, the OVA challenge induced significant immediate changes manifesting as peribronchial ground glass opacities, consolidations, air-trapping, and paradoxical proximal airway dilatations. After resolution of immediate response, multiple episodes of AHRs occurred with paradoxical proximal airway dilatation and peripheral air-trapping in late phase over a prolonged time period in vivo. Understanding of airflow limitation based on the structural changes of asthmatic airway would be helpful to make an appropriate drug delivery strategy for the treatment of asthma.
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Affiliation(s)
- Jae-Woo Jung
- Institute of Allergy and Clinical Immunology, Seoul National University Medical Research Center, Seoul, Korea.,Department of Internal Medicine, Chung-Ang University College of Medicine, Seoul, Korea
| | - Jung Suk Oh
- Department of Radiology, Catholic University, Seoul St. Mary's Hospital, Seoul, Korea
| | - Boram Bae
- Institute of Allergy and Clinical Immunology, Seoul National University Medical Research Center, Seoul, Korea
| | - Yoon Hae Ahn
- Department of Internal Medicine, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Korea
| | - Lucy Wooyeon Kim
- Institute of Allergy and Clinical Immunology, Seoul National University Medical Research Center, Seoul, Korea
| | - Jiwoong Choi
- Department of Internal Medicine, University of Kansas School of Medicine, Kansas City, KS, USA.,Department of Bioengineering, University of Kansas, Lawrence, KS, USA
| | - Hye-Young Kim
- Institute of Allergy and Clinical Immunology, Seoul National University Medical Research Center, Seoul, Korea.,Laboratory of Mucosal Immunology, Department of Biomedical Sciences, Seoul National University College of Medicine, Seoul, Korea
| | - Hye-Ryun Kang
- Institute of Allergy and Clinical Immunology, Seoul National University Medical Research Center, Seoul, Korea. .,Department of Internal Medicine, Seoul National University College of Medicine, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Korea.
| | - Chang Hyun Lee
- Department of Radiology and Institute of Radiation, Seoul National University College of Medicine, Seoul National University Hospital, 103 Daehak-ro, Jongno-gu, Seoul, 03080, Korea.
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13
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Redente EF, Black BP, Backos DS, Bahadur AN, Humphries SM, Lynch DA, Tuder RM, Zemans RL, Riches DWH. Persistent, Progressive Pulmonary Fibrosis and Epithelial Remodeling in Mice. Am J Respir Cell Mol Biol 2021; 64:669-676. [PMID: 33406369 PMCID: PMC8456888 DOI: 10.1165/rcmb.2020-0542ma] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 12/22/2020] [Indexed: 12/15/2022] Open
Abstract
Idiopathic pulmonary fibrosis (IPF) is a progressive fibrotic interstitial lung disease with underlying mechanisms that have been primarily investigated in mice after intratracheal instillation of a single dose of bleomycin. However, the model has significant limitations, including transient fibrosis that spontaneously resolves and its failure to fully recapitulate the epithelial remodeling in the lungs of patients with IPF. Thus, there remains an unmet need for a preclinical model with features that more closely resemble the human disease. Repetitive intratracheal instillation of bleomycin has previously been shown to recapitulate some of these features, but the instillation procedure is complex, and the long-term consequences on epithelial remodeling and fibrosis persistence and progression remain poorly understood. Here, we developed a simplified repetitive bleomycin instillation strategy consisting of three bi-weekly instillations that leads to persistent and progressive pulmonary fibrosis. Lung histology demonstrates increased collagen deposition, fibroblast accumulation, loss of type I and type II alveolar epithelial cells within fibrotic areas, bronchiolization of the lung parenchyma with CCSP+ cells, remodeling of the distal lung into cysts reminiscent of simple honeycombing, and accumulation of hyperplastic transitional KRT8+ epithelial cells. Micro-computed tomographic imaging demonstrated significant traction bronchiectasis and subpleural fibrosis. Thus, the simplified repetitive bleomycin instillation strategy leads to progressive fibrosis and recapitulates the histological and radiographic characteristics of IPF. Compared with the single bleomycin instillation model, we suggest that the simplified repetitive instillation model may be better suited to address mechanistic questions about IPF pathogenesis and preclinical studies of antifibrotic drug candidates.
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Affiliation(s)
- Elizabeth F. Redente
- Program in Cell Biology, Department of Pediatrics, and
- Department of Research, Veterans Affairs Eastern Colorado Health Care System, Denver, Colorado
- Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine
| | - Bart P. Black
- Program in Cell Biology, Department of Pediatrics, and
| | | | - Ali N. Bahadur
- Bruker BioSpin Corporation, Billerica, Massachusetts; and
| | | | - David A. Lynch
- Department of Radiology, National Jewish Health, Denver, Colorado
- Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine
| | - Rubin M. Tuder
- Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine
| | - Rachel L. Zemans
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, and
- Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, Michigan
| | - David W. H. Riches
- Program in Cell Biology, Department of Pediatrics, and
- Department of Research, Veterans Affairs Eastern Colorado Health Care System, Denver, Colorado
- Division of Pulmonary Sciences and Critical Care Medicine, Department of Medicine
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado
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14
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Niedbalski PJ, Cochran AS, Freeman MS, Guo J, Fugate EM, Davis CB, Dahlke J, Quirk JD, Varisco BM, Woods JC, Cleveland ZI. Validating in vivo hyperpolarized 129 Xe diffusion MRI and diffusion morphometry in the mouse lung. Magn Reson Med 2021; 85:2160-2173. [PMID: 33017076 PMCID: PMC8544163 DOI: 10.1002/mrm.28539] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 08/27/2020] [Accepted: 09/14/2020] [Indexed: 02/03/2023]
Abstract
PURPOSE Diffusion and lung morphometry imaging using hyperpolarized gases are promising tools to quantify pulmonary microstructure noninvasively in humans and in animal models. These techniques assume the motion encoded is exclusively diffusive gas displacement, but the impact of cardiac motion on measurements has never been explored. Furthermore, although diffusion morphometry has been validated against histology in humans and mice using 3 He, it has never been validated in mice for 129 Xe. Here, we examine the effect of cardiac motion on diffusion imaging and validate 129 Xe diffusion morphometry in mice. THEORY AND METHODS Mice were imaged using gradient-echo-based diffusion imaging, and apparent diffusion-coefficient (ADC) maps were generated with and without cardiac gating. Diffusion-weighted images were fit to a previously developed theoretical model using Bayesian probability theory, producing morphometric parameters that were compared with conventional histology. RESULTS Cardiac gating had no significant impact on ADC measurements (dual-gating: ADC = 0.020 cm2 /s, single-gating: ADC = 0.020 cm2 /s; P = .38). Diffusion-morphometry-generated maps of ADC (mean, 0.0165 ± 0.0001 cm2 /s) and acinar dimensions (alveolar sleeve depth [h] = 44 µm, acinar duct radii [R] = 99 µm, mean linear intercept [Lm ] = 74 µm) that agreed well with conventional histology (h = 45 µm, R = 108 µm, Lm = 63 µm). CONCLUSION Cardiac motion has negligible impact on 129 Xe ADC measurements in mice, arguing its impact will be similarly minimal in humans, where relative cardiac motion is reduced. Hyperpolarized 129 Xe diffusion morphometry accurately and noninvasively maps the dimensions of lung microstructure, suggesting it can quantify the pulmonary microstructure in mouse models of lung disease.
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Affiliation(s)
- Peter J. Niedbalski
- Center for Pulmonary Imaging Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
| | - Alexander S. Cochran
- Center for Pulmonary Imaging Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH
| | - Matthew S. Freeman
- Center for Pulmonary Imaging Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH
| | - Jinbang Guo
- Center for Pulmonary Imaging Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
| | - Elizabeth M. Fugate
- Imaging Research Center, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
| | - Cory B. Davis
- Center for Pulmonary Imaging Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
- Department of Physics, West Texas A&M University, Canyon, TX
| | - Jerry Dahlke
- Department of Radiology, Duke University School of Medicine, Durham, NC
| | - James D. Quirk
- Department of Radiology, Washington University, St. Louis, MO
| | - Brian M. Varisco
- Division of Critical Care Medicine, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
- Department of Pediatrics, University of Cincinnati, Cincinnati, OH
| | - Jason C. Woods
- Center for Pulmonary Imaging Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
- Imaging Research Center, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
- Department of Radiology, Washington University, St. Louis, MO
- Department of Pediatrics, University of Cincinnati, Cincinnati, OH
| | - Zackary I. Cleveland
- Center for Pulmonary Imaging Research, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
- Department of Biomedical Engineering, University of Cincinnati, Cincinnati, OH
- Imaging Research Center, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
- Department of Pediatrics, University of Cincinnati, Cincinnati, OH
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15
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Knudsen L, Brandenberger C, Ochs M. Stereology as the 3D tool to quantitate lung architecture. Histochem Cell Biol 2020; 155:163-181. [PMID: 33051774 PMCID: PMC7910236 DOI: 10.1007/s00418-020-01927-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/26/2020] [Indexed: 01/12/2023]
Abstract
Stereology is the method of choice for the quantitative assessment of biological objects in microscopy. It takes into account the fact that, in traditional microscopy such as conventional light and transmission electron microscopy, although one has to rely on measurements on nearly two-dimensional sections from fixed and embedded tissue samples, the quantitative data obtained by these measurements should characterize the real three-dimensional properties of the biological objects and not just their “flatland” appearance on the sections. Thus, three-dimensionality is a built-in property of stereological sampling and measurement tools. Stereology is, therefore, perfectly suited to be combined with 3D imaging techniques which cover a wide range of complementary sample sizes and resolutions, e.g. micro-computed tomography, confocal microscopy and volume electron microscopy. Here, we review those stereological principles that are of particular relevance for 3D imaging and provide an overview of applications of 3D imaging-based stereology to the lung in health and disease. The symbiosis of stereology and 3D imaging thus provides the unique opportunity for unbiased and comprehensive quantitative characterization of the three-dimensional architecture of the lung from macro to nano scale.
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Affiliation(s)
- Lars Knudsen
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research (DZL), Hannover, Germany.,REBIRTH Cluster of Excellence, Hannover, Germany
| | - Christina Brandenberger
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany.,Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), German Center for Lung Research (DZL), Hannover, Germany.,REBIRTH Cluster of Excellence, Hannover, Germany
| | - Matthias Ochs
- Institute of Functional Anatomy, Charité-Universitätsmedizin Berlin, Philippstr. 11, 10115, Berlin, Germany. .,German Center for Lung Research (DZL), Berlin, Germany.
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16
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Davenport ML, Sherrill TP, Blackwell TS, Edmonds MD. Perfusion and Inflation of the Mouse Lung for Tumor Histology. J Vis Exp 2020. [PMID: 32831298 DOI: 10.3791/60605] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The ability to evaluate lung histology is critical for the fields of lung cancer research and cancer metastasis. It is equally important to perform necropsies rapidly and efficiently from studies without sacrificing the quality of the tissues procured. The goal of this protocol is to present a method to rapidly perfuse, inflate, and fix mouse lungs for downstream histological analysis. This method does not standardize lung inflation; thus, it does not require any special procedures or equipment and instead simply instills fixative directly through the trachea following perfusion through the heart. This allows for sufficient estimation of tumor size, histology, and scoring. This also allows for the collection of frozen tissue prior to lung tissue fixation. This method is limited in that it does not allow for later morphometric quantification of the lung; however, it is more than sufficient for lung tumor analysis from genetically engineered mouse models (GEMMs), syngeneic models, as well as xenograft tumor and metastasis studies.
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Affiliation(s)
| | - Taylor P Sherrill
- Department of Medicine, Division of Allergy, Pulmonary, and Critical Care Medicine, Vanderbilt University School of Medicine
| | - Timothy S Blackwell
- Department of Medicine, Division of Allergy, Pulmonary, and Critical Care Medicine, Vanderbilt University School of Medicine
| | - Mick D Edmonds
- Department of Genetics, University of Alabama at Birmingham;
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17
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Scott AJ, Chandler CE, Ellis SR, Heeren RMA, Ernst RK. Maintenance of Deep Lung Architecture and Automated Airway Segmentation for 3D Mass Spectrometry Imaging. Sci Rep 2019; 9:20160. [PMID: 31882724 PMCID: PMC6934789 DOI: 10.1038/s41598-019-56364-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 12/06/2019] [Indexed: 12/13/2022] Open
Abstract
Mass spectrometry imaging (MSI) is a technique for mapping the spatial distributions of molecules in sectioned tissue. Histology-preserving tissue preparation methods are central to successful MSI studies. Common fixation methods, used to preserve tissue morphology, can result in artifacts in the resulting MSI experiment including delocalization of analytes, altered adduct profiles, and loss of key analytes due to irreversible cross-linking and diffusion. This is especially troublesome in lung and airway samples, in which histology and morphology is best interpreted from 3D reconstruction, requiring the large and small airways to remain inflated during analysis. Here, we developed an MSI-compatible inflation containing as few exogenous components as possible, forgoing perfusion, fixation, and addition of salt solutions upon inflation that resulted in an ungapped 3D molecular reconstruction through more than 300 microns. We characterized a series of polyunsaturated phospholipids (PUFA-PLs), specifically phosphatidylinositol (-PI) lipids linked to lethal inflammation in bacterial infection and mapped them in serial sections of inflated mouse lung. PUFA-PIs were identified using spatial lipidomics and determined to be determinant markers of major airway features using unsupervised hierarchical clustering. Deep lung architecture was preserved using this inflation approach and the resulting sections are compatible with multiple MSI modalities, automated interpretation software, and serial 3D reconstruction.
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Affiliation(s)
- Alison J Scott
- Department of Microbial Pathogenesis, University of Maryland School of Dentistry, Baltimore, 21201, USA.,Maastricht Multimodal Molecular Imaging (M4I) Institute, Maastricht University, Maastricht, 6229ER, Netherlands
| | - Courtney E Chandler
- Department of Microbial Pathogenesis, University of Maryland School of Dentistry, Baltimore, 21201, USA
| | - Shane R Ellis
- Maastricht Multimodal Molecular Imaging (M4I) Institute, Maastricht University, Maastricht, 6229ER, Netherlands
| | - Ron M A Heeren
- Maastricht Multimodal Molecular Imaging (M4I) Institute, Maastricht University, Maastricht, 6229ER, Netherlands
| | - Robert K Ernst
- Department of Microbial Pathogenesis, University of Maryland School of Dentistry, Baltimore, 21201, USA.
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18
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Abstract
Hollow organs such as the lungs pose a considerable challenge for post-mortem imaging in preclinical research owing to their extremely low contrast and high structural complexity. The aim of our study was to enhance the contrast of tuberculosis lesions for their stratification by 3D x-ray–based virtual slicing. Organ samples were taken from five control and five tuberculosis-infected mice. Micro-Computed Tomography (CT) scans of the subjects were acquired in vivo (without contrast agent) and post-mortem (with contrast agent). The proposed contrast-enhancing technique consists of x-ray contrast agent uptake (silver nitrate and iodine) by immersion. To create the histology ground-truth, the CT scan of the paraffin block guided the sectioning towards specific planes of interest. The digitalized histological slides reveal the presence, extent, and appearance of the contrast agents in lung structures and organized aggregates of immune cells. These findings correlate with the contrast-enhanced micro-CT slice. The abnormal densities in the lungs due to tuberculosis disease are concentrated in the right tail of the lung intensity histograms. The increase in the width of the right tail (~376%) indicates a contrast enhancement of the details of the abnormal densities. Postmortem contrast agents enhance the x-ray attenuation in tuberculosis lesions to allow 3D visualization by polychromatic x-ray CT, providing an advantageous tool for virtual slicing of whole lungs. The proposed contrast-enhancing technique combined with computational methods and the diverse micro-CT modalities will open the doors to the stratification of lesion types associated with infectious diseases.
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19
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Buchacker T, Mühlfeld C, Wrede C, Wagner WL, Beare R, McCormick M, Grothausmann R. Assessment of the Alveolar Capillary Network in the Postnatal Mouse Lung in 3D Using Serial Block-Face Scanning Electron Microscopy. Front Physiol 2019; 10:1357. [PMID: 31824323 PMCID: PMC6881265 DOI: 10.3389/fphys.2019.01357] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 10/14/2019] [Indexed: 12/20/2022] Open
Abstract
The alveolar capillary network (ACN) has a large surface area that provides the basis for an optimized gas exchange in the lung. It needs to adapt to morphological changes during early lung development and alveolarization. Structural alterations of the pulmonary vasculature can lead to pathological functional conditions such as in bronchopulmonary dysplasia and various other lung diseases. To understand the development of the ACN and its impact on the pathogenesis of lung diseases, methods are needed that enable comparative analyses of the complex three-dimensional structure of the ACN at different developmental stages and under pathological conditions. In this study a newborn mouse lung was imaged with serial block-face scanning electron microscopy (SBF-SEM) to investigate the ACN and its surrounding structures before the alveolarization process begins. Most parts but not all of the examined ACN contain two layers of capillaries, which were repeatedly connected with each other. A path from an arteriole to a venule was extracted and straightened to allow cross-sectional visualization of the data along the path within a plane. This allows a qualitative characterization of the structures that erythrocytes pass on their way through the ACN. One way to define regions of the ACN supplied by specific arterioles is presented and used for analyses. Pillars, possibly intussusceptive, were found in the vasculature but no specific pattern was observed in regard to parts of the saccular septa. This study provides 3D information with a resolution of about 150 nm on the microscopic structure of a newborn mouse lung and outlines some of the potentials and challenges of SBF-SEM for 3D analyses of the ACN.
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Affiliation(s)
- Tobias Buchacker
- Institute of Functional and Applied Anatomy, Medizinische Hochschule Hannover, Hanover, Germany.,Biomedical Research in Endstage and Obstructive Lung Research (BREATH), Member of the German Center for Lung Research, Hanover, Germany
| | - Christian Mühlfeld
- Institute of Functional and Applied Anatomy, Medizinische Hochschule Hannover, Hanover, Germany.,Biomedical Research in Endstage and Obstructive Lung Research (BREATH), Member of the German Center for Lung Research, Hanover, Germany.,REBIRTH Cluster of Excellence, Hanover, Germany
| | - Christoph Wrede
- Institute of Functional and Applied Anatomy, Medizinische Hochschule Hannover, Hanover, Germany.,Biomedical Research in Endstage and Obstructive Lung Research (BREATH), Member of the German Center for Lung Research, Hanover, Germany.,Research Core Unit Electron Microscopy, Hannover Medical School, Hanover, Germany
| | - Willi L Wagner
- Department of Diagnostic and Interventional Radiology (DIR), University of Heidelberg, Heidelberg, Germany.,Translational Lung Research Center (TLRC), Member of the German Center for Lung Research (DZL), University of Heidelberg, Heidelberg, Germany
| | - Richard Beare
- Department of Medicine, Monash University, Melbourne, VIC, Australia.,Developmental Imaging, Murdoch Children's Research Institute, Melbourne, VIC, Australia
| | | | - Roman Grothausmann
- Institute of Functional and Applied Anatomy, Medizinische Hochschule Hannover, Hanover, Germany.,Biomedical Research in Endstage and Obstructive Lung Research (BREATH), Member of the German Center for Lung Research, Hanover, Germany
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20
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Deng Y, Rowe KJ, Chaudhary KR, Yang A, Mei SHJ, Stewart DJ. Optimizing imaging of the rat pulmonary microvasculature by micro-computed tomography. Pulm Circ 2019; 9:2045894019883613. [PMID: 31700608 PMCID: PMC6823983 DOI: 10.1177/2045894019883613] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 09/24/2019] [Indexed: 12/14/2022] Open
Abstract
Micro-computed tomography (micro-CT) is used in pre-clinical research to generate high-resolution three-dimensional (3D) images of organs and tissues. When combined with intravascular contrast agents, micro-CT can provide 3D visualization and quantification of vascular networks in many different organs. However, the lungs present a particular challenge for contrast perfusion due to the complexity and fragile nature of the lung microcirculation. The protocol described here has been optimized to achieve consistent lung perfusion of the microvasculature to vessels < 20 microns in both normal and pulmonary arterial hypertension rats. High-resolution 3D micro-CT imaging can be used to better visualize changes in 3D architecture of the lung microcirculation in pulmonary vascular disease and to assess the impact of therapeutic strategies on microvascular structure in animal models of pulmonary arterial hypertension.
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Affiliation(s)
- Yupu Deng
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Canada
| | - Katelynn J Rowe
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Canada
| | - Ketul R Chaudhary
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Canada
| | - Anli Yang
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Canada
| | - Shirley H J Mei
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Canada
| | - Duncan J Stewart
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Canada.,Division of Cardiology, Department of Medicine, University of Ottawa, Ottawa, Canada
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21
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Sarabia-Vallejos MA, Zuñiga M, Hurtado DE. The role of three-dimensionality and alveolar pressure in the distribution and amplification of alveolar stresses. Sci Rep 2019; 9:8783. [PMID: 31217511 PMCID: PMC6584652 DOI: 10.1038/s41598-019-45343-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 06/04/2019] [Indexed: 12/30/2022] Open
Abstract
Alveolar stresses are fundamental to enable the respiration process in mammalians and have recently gained increasing attention due to their mechanobiological role in the pathogenesis and development of respiratory diseases. Despite the fundamental physiological role of stresses in the alveolar wall, the determination of alveolar stresses remains challenging, and our current knowledge is largely drawn from 2D studies that idealize the alveolar septal wall as a spring or a planar continuum. Here we study the 3D stress distribution in alveolar walls of normal lungs by combining ex-vivo micro-computed tomography and 3D finite-element analysis. Our results show that alveolar walls are subject to a fully 3D state of stresses rather than to a pure axial stress state. To understand the contributions of the different components and deformation modes, we decompose the stress tensor field into hydrostatic and deviatoric components, which are associated with isotropic and distortional stresses, respectively. Stress concentrations arise in localized regions of the alveolar microstructure, with magnitudes that can be up to 27 times the applied alveolar pressure. Interestingly, we show that the stress amplification factor strongly depends on the level of alveolar pressure, i.e, stresses do not scale proportional to the applied alveolar pressure. In addition, we show that 2D techniques to assess alveolar stresses consistently overestimate the stress magnitude in alveolar walls, particularly for lungs under high transpulmonary pressure. These findings take particular relevance in the study of stress-induced remodeling of the emphysematous lung and in ventilator-induced lung injury, where the relation between transpulmonary pressure and alveolar wall stress is key to understand mechanotransduction processes in pneumocytes.
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Affiliation(s)
- Mauricio A Sarabia-Vallejos
- Department of Structural and Geotechnical Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Vicuña Mackenna 4860, Santiago, Chile.,Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Vicuña Mackenna 4860, Santiago, Chile
| | - Matias Zuñiga
- Department of Structural and Geotechnical Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Vicuña Mackenna 4860, Santiago, Chile
| | - Daniel E Hurtado
- Department of Structural and Geotechnical Engineering, School of Engineering, Pontificia Universidad Católica de Chile, Vicuña Mackenna 4860, Santiago, Chile. .,Institute for Biological and Medical Engineering, Schools of Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Vicuña Mackenna 4860, Santiago, Chile.
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22
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Chaurand P, Liu W, Borschneck D, Levard C, Auffan M, Paul E, Collin B, Kieffer I, Lanone S, Rose J, Perrin J. Multi-scale X-ray computed tomography to detect and localize metal-based nanomaterials in lung tissues of in vivo exposed mice. Sci Rep 2018. [PMID: 29535369 PMCID: PMC5849692 DOI: 10.1038/s41598-018-21862-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
In this methodological study, we demonstrated the relevance of 3D imaging performed at various scales for the ex vivo detection and location of cerium oxide nanomaterials (CeO2-NMs) in mouse lung. X-ray micro-computed tomography (micro-CT) with a voxel size from 14 µm to 1 µm (micro-CT) was combined with X-ray nano-computed tomography with a voxel size of 63 nm (nano-CT). An optimized protocol was proposed to facilitate the sample preparation, to minimize the experimental artifacts and to optimize the contrast of soft tissues exposed to metal-based nanomaterials (NMs). 3D imaging of the NMs biodistribution in lung tissues was consolidated by combining a vast variety of techniques in a correlative approach: histological observations, 2D chemical mapping and speciation analysis were performed for an unambiguous detection of NMs. This original methodological approach was developed following a worst-case scenario of exposure, i.e. high dose of exposure with administration via intra-tracheal instillation. Results highlighted both (i) the non-uniform distribution of CeO2-NMs within the entire lung lobe (using large field-of-view micro-CT) and (ii) the detection of CeO2-NMs down to the individual cell scale, e.g. macrophage scale (using nano-CT with a voxel size of 63 nm).
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Affiliation(s)
- Perrine Chaurand
- Aix Marseille Univ, CNRS, IRD, INRA, Coll France, CEREGE, Aix-en-Provence, France. .,International Consortium for the Environmental Implications of Nanotechnology iCEINT, CNRS-Duke University, Aix en Provence, France.
| | - Wei Liu
- Aix Marseille Univ, CNRS, IRD, INRA, Coll France, CEREGE, Aix-en-Provence, France.,International Consortium for the Environmental Implications of Nanotechnology iCEINT, CNRS-Duke University, Aix en Provence, France
| | - Daniel Borschneck
- Aix Marseille Univ, CNRS, IRD, INRA, Coll France, CEREGE, Aix-en-Provence, France.,International Consortium for the Environmental Implications of Nanotechnology iCEINT, CNRS-Duke University, Aix en Provence, France
| | - Clément Levard
- Aix Marseille Univ, CNRS, IRD, INRA, Coll France, CEREGE, Aix-en-Provence, France.,International Consortium for the Environmental Implications of Nanotechnology iCEINT, CNRS-Duke University, Aix en Provence, France
| | - Mélanie Auffan
- Aix Marseille Univ, CNRS, IRD, INRA, Coll France, CEREGE, Aix-en-Provence, France.,International Consortium for the Environmental Implications of Nanotechnology iCEINT, CNRS-Duke University, Aix en Provence, France
| | - Emmanuel Paul
- INSERM, Equipe 04, U955, Creteil, France.,Univ Paris Est Creteil, IMRB, Fac Med, DHU A TVB, Creteil, France
| | - Blanche Collin
- Aix Marseille Univ, CNRS, IRD, INRA, Coll France, CEREGE, Aix-en-Provence, France.,International Consortium for the Environmental Implications of Nanotechnology iCEINT, CNRS-Duke University, Aix en Provence, France
| | - Isabelle Kieffer
- OSUG-FAME, UMS 832 CNRS-Univ. Grenoble Alpes, F-38041, Grenoble, France
| | - Sophie Lanone
- INSERM, Equipe 04, U955, Creteil, France.,Univ Paris Est Creteil, IMRB, Fac Med, DHU A TVB, Creteil, France
| | - Jérôme Rose
- Aix Marseille Univ, CNRS, IRD, INRA, Coll France, CEREGE, Aix-en-Provence, France.,International Consortium for the Environmental Implications of Nanotechnology iCEINT, CNRS-Duke University, Aix en Provence, France
| | - Jeanne Perrin
- Aix Marseille Univ, CNRS, IRD, INRA, Coll France, CEREGE, Aix-en-Provence, France.,Univ Avignon, Inst Mediterraneen Biodiversite & Ecol Marine & C, Aix Marseille Univ, CNRS, IRD, Marseille, France.,AP HM La Conception, CECOS, Lab Reprod Biol, Dept Gynecol Obstet & Reprod Med, Pole Femmes Parents Enfants, Marseille, France
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23
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Jenkins RG, Moore BB, Chambers RC, Eickelberg O, Königshoff M, Kolb M, Laurent GJ, Nanthakumar CB, Olman MA, Pardo A, Selman M, Sheppard D, Sime PJ, Tager AM, Tatler AL, Thannickal VJ, White ES. An Official American Thoracic Society Workshop Report: Use of Animal Models for the Preclinical Assessment of Potential Therapies for Pulmonary Fibrosis. Am J Respir Cell Mol Biol 2017; 56:667-679. [PMID: 28459387 DOI: 10.1165/rcmb.2017-0096st] [Citation(s) in RCA: 233] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Numerous compounds have shown efficacy in limiting development of pulmonary fibrosis using animal models, yet few of these compounds have replicated these beneficial effects in clinical trials. Given the challenges associated with performing clinical trials in patients with idiopathic pulmonary fibrosis (IPF), it is imperative that preclinical data packages be robust in their analyses and interpretations to have the best chance of selecting promising drug candidates to advance to clinical trials. The American Thoracic Society has convened a group of experts in lung fibrosis to discuss and formalize recommendations for preclinical assessment of antifibrotic compounds. The panel considered three major themes (choice of animal, practical considerations of fibrosis modeling, and fibrotic endpoints for evaluation). Recognizing the need for practical considerations, we have taken a pragmatic approach. The consensus view is that use of the murine intratracheal bleomycin model in animals of both genders, using hydroxyproline measurements for collagen accumulation along with histologic assessments, is the best-characterized animal model available for preclinical testing. Testing of antifibrotic compounds in this model is recommended to occur after the acute inflammatory phase has subsided (generally after Day 7). Robust analyses may also include confirmatory studies in human IPF specimens and validation of results in a second system using in vivo or in vitro approaches. The panel also strongly encourages the publication of negative results to inform the lung fibrosis community. These recommendations are for preclinical therapeutic evaluation only and are not intended to dissuade development of emerging technologies to better understand IPF pathogenesis.
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24
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Stauber M, Boldt K, Wrede C, Weidemann M, Kellner M, Schuster-Gossler K, Kühnel MP, Hegermann J, Ueffing M, Gossler A. 1700012B09Rik, a FOXJ1 effector gene active in ciliated tissues of the mouse but not essential for motile ciliogenesis. Dev Biol 2017; 429:186-199. [PMID: 28666954 DOI: 10.1016/j.ydbio.2017.06.027] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 03/28/2017] [Accepted: 06/26/2017] [Indexed: 02/02/2023]
Abstract
In humans and mice, motile cilia occur on the surface of the embryonic ventral node, on respiratory and ependymal epithelia and in reproductive organs where they ensure normal left-right asymmetry of the organism, mucociliary clearance of airways, homeostasis of the cerebrospinal fluid and fertility. The genetic programme for the formation of motile cilia, thus critical for normal development and health, is switched on by the key transcription factor FOXJ1. In previous microarray screens for murine FOXJ1 effectors, we identified candidates for novel factors involved in motile ciliogenesis, including both genes that are well conserved throughout metazoa and beyond, like FOXJ1 itself, and genes without overt homologues outside higher vertebrates. Here we examine one of the novel murine FOXJ1 effectors, the uncharacterised 1700012B09Rik whose homologues appear to be restricted to higher vertebrates. In mouse embryos and adults, 1700012B09Rik is predominantly expressed in motile ciliated tissues in a FOXJ1-dependent manner. 1700012B09RIK protein localises to basal bodies of cilia in cultured cells. Detailed analysis of 1700012B09RiklacZ knock-out mice reveals no impaired function of motile cilia or non-motile cilia. In conclusion, this novel FOXJ1 effector is associated mainly with motile cilia but - in contrast to other known FOXJ1 targets - its putative ciliary function is not essential for development or health in the mouse, consistent with a late emergence during evolution of motile ciliogenesis.
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Affiliation(s)
- Michael Stauber
- Institute for Molecular Biology, OE5250, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany; REBIRTH Cluster of Excellence, Hannover, Germany.
| | - Karsten Boldt
- Institute of Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Elfriede-Aulhorn-Str. 7, 72076 Tübingen, Germany
| | - Christoph Wrede
- Institute of Functional and Applied Anatomy, OE8840, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany; REBIRTH Cluster of Excellence, Hannover, Germany; German Centre for Lung Research (DZL), Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Germany
| | - Marina Weidemann
- Institute for Molecular Biology, OE5250, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany; REBIRTH Cluster of Excellence, Hannover, Germany
| | - Manuela Kellner
- Institute of Functional and Applied Anatomy, OE8840, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany; REBIRTH Cluster of Excellence, Hannover, Germany; German Centre for Lung Research (DZL), Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Germany
| | - Karin Schuster-Gossler
- Institute for Molecular Biology, OE5250, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany; REBIRTH Cluster of Excellence, Hannover, Germany
| | - Mark Philipp Kühnel
- Institute for Pathology, OE5110, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany; German Centre for Lung Research (DZL), Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Germany
| | - Jan Hegermann
- Institute of Functional and Applied Anatomy, OE8840, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany; REBIRTH Cluster of Excellence, Hannover, Germany; German Centre for Lung Research (DZL), Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Germany
| | - Marius Ueffing
- Institute of Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Elfriede-Aulhorn-Str. 7, 72076 Tübingen, Germany
| | - Achim Gossler
- Institute for Molecular Biology, OE5250, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany; REBIRTH Cluster of Excellence, Hannover, Germany
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25
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Schneider JP, Arkenau M, Knudsen L, Wedekind D, Ochs M. Lung remodeling in aging surfactant protein D deficient mice. Ann Anat 2017; 211:158-175. [DOI: 10.1016/j.aanat.2017.01.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2016] [Revised: 01/23/2017] [Accepted: 01/24/2017] [Indexed: 01/13/2023]
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26
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Buschle LR, Kurz FT, Kampf T, Wagner WL, Duerr J, Stiller W, Konietzke P, Wünnemann F, Mall MA, Wielpütz MO, Schlemmer HP, Ziener CH. Dephasing and diffusion on the alveolar surface. Phys Rev E 2017; 95:022415. [PMID: 28297921 DOI: 10.1103/physreve.95.022415] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Indexed: 06/06/2023]
Abstract
We propose a surface model of spin dephasing in lung tissue that includes both susceptibility and diffusion effects to provide a closed-form solution of the Bloch-Torrey equation on the alveolar surface. The nonlocal susceptibility effects of the model are validated against numerical simulations of spin dephasing in a realistic lung tissue geometry acquired from synchotron-based μCT data sets of mouse lung tissue, and against simulations in the well-known Wigner-Seitz model geometry. The free induction decay is obtained in dependence on microscopic tissue parameters and agrees very well with in vivo lung measurements at 1.5 Tesla to allow a quantification of the local mean alveolar radius. Our results are therefore potentially relevant for the clinical diagnosis and therapy of pulmonary diseases.
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Affiliation(s)
- L R Buschle
- German Cancer Research Center - DKFZ, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
- Neuroradiology, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - F T Kurz
- German Cancer Research Center - DKFZ, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
- Neuroradiology, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
| | - T Kampf
- University of Würzburg, Department of Experimental Physics 5, Am Hubland, 97074 Würzburg, Germany
| | - W L Wagner
- University of Heidelberg, Department of Diagnostic and Interventional Radiology, Im Neuenheimer Feld 110, 69120 Heidelberg, Germany
- University of Heidelberg, Translational Lung Research Center Heidelberg (TLRC), Member of German Center for Lung Research (DZL), Im Neuenheimer Feld 156, 69120 Heidelberg, Germany
| | - J Duerr
- University of Heidelberg, Translational Lung Research Center Heidelberg (TLRC), Member of German Center for Lung Research (DZL), Im Neuenheimer Feld 156, 69120 Heidelberg, Germany
- University of Heidelberg, Department of Translational Pulmonology, Im Neuenheimer Feld 156, 69120 Heidelberg, Germany
| | - W Stiller
- University of Heidelberg, Department of Diagnostic and Interventional Radiology, Im Neuenheimer Feld 110, 69120 Heidelberg, Germany
- University of Heidelberg, Translational Lung Research Center Heidelberg (TLRC), Member of German Center for Lung Research (DZL), Im Neuenheimer Feld 156, 69120 Heidelberg, Germany
| | - P Konietzke
- University of Heidelberg, Department of Diagnostic and Interventional Radiology, Im Neuenheimer Feld 110, 69120 Heidelberg, Germany
- University of Heidelberg, Translational Lung Research Center Heidelberg (TLRC), Member of German Center for Lung Research (DZL), Im Neuenheimer Feld 156, 69120 Heidelberg, Germany
| | - F Wünnemann
- University of Heidelberg, Department of Diagnostic and Interventional Radiology, Im Neuenheimer Feld 110, 69120 Heidelberg, Germany
| | - M A Mall
- University of Heidelberg, Translational Lung Research Center Heidelberg (TLRC), Member of German Center for Lung Research (DZL), Im Neuenheimer Feld 156, 69120 Heidelberg, Germany
- University of Heidelberg, Department of Translational Pulmonology, Im Neuenheimer Feld 156, 69120 Heidelberg, Germany
| | - M O Wielpütz
- University of Heidelberg, Department of Diagnostic and Interventional Radiology, Im Neuenheimer Feld 110, 69120 Heidelberg, Germany
- University of Heidelberg, Translational Lung Research Center Heidelberg (TLRC), Member of German Center for Lung Research (DZL), Im Neuenheimer Feld 156, 69120 Heidelberg, Germany
| | - H P Schlemmer
- German Cancer Research Center - DKFZ, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - C H Ziener
- German Cancer Research Center - DKFZ, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
- Neuroradiology, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany
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27
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Gilhodes JC, Julé Y, Kreuz S, Stierstorfer B, Stiller D, Wollin L. Quantification of Pulmonary Fibrosis in a Bleomycin Mouse Model Using Automated Histological Image Analysis. PLoS One 2017; 12:e0170561. [PMID: 28107543 PMCID: PMC5249201 DOI: 10.1371/journal.pone.0170561] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2016] [Accepted: 01/08/2017] [Indexed: 12/13/2022] Open
Abstract
Current literature on pulmonary fibrosis induced in animal models highlights the need of an accurate, reliable and reproducible histological quantitative analysis. One of the major limits of histological scoring concerns the fact that it is observer-dependent and consequently subject to variability, which may preclude comparative studies between different laboratories. To achieve a reliable and observer-independent quantification of lung fibrosis we developed an automated software histological image analysis performed from digital image of entire lung sections. This automated analysis was compared to standard evaluation methods with regard to its validation as an end-point measure of fibrosis. Lung fibrosis was induced in mice by intratracheal administration of bleomycin (BLM) at 0.25, 0.5, 0.75 and 1 mg/kg. A detailed characterization of BLM-induced fibrosis was performed 14 days after BLM administration using lung function testing, micro-computed tomography and Ashcroft scoring analysis. Quantification of fibrosis by automated analysis was assessed based on pulmonary tissue density measured from thousands of micro-tiles processed from digital images of entire lung sections. Prior to analysis, large bronchi and vessels were manually excluded from the original images. Measurement of fibrosis has been expressed by two indexes: the mean pulmonary tissue density and the high pulmonary tissue density frequency. We showed that tissue density indexes gave access to a very accurate and reliable quantification of morphological changes induced by BLM even for the lowest concentration used (0.25 mg/kg). A reconstructed 2D-image of the entire lung section at high resolution (3.6 μm/pixel) has been performed from tissue density values allowing the visualization of their distribution throughout fibrotic and non-fibrotic regions. A significant correlation (p<0.0001) was found between automated analysis and the above standard evaluation methods. This correlation establishes automated analysis as a novel end-point measure of BLM-induced lung fibrosis in mice, which will be very valuable for future preclinical drug explorations.
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Affiliation(s)
| | | | - Sebastian Kreuz
- Immunology and Respiratory, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, Germany
| | - Birgit Stierstorfer
- Immunology and Respiratory, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, Germany
| | - Detlef Stiller
- Immunology and Respiratory, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, Germany
| | - Lutz Wollin
- Immunology and Respiratory, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach, Germany
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28
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Vasilescu DM, Phillion AB, Tanabe N, Kinose D, Paige DF, Kantrowitz JJ, Liu G, Liu H, Fishbane N, Verleden SE, Vanaudenaerde BM, Lenburg M, Stevenson CS, Spira A, Cooper JD, Hackett TL, Hogg JC. Nondestructive cryomicro-CT imaging enables structural and molecular analysis of human lung tissue. J Appl Physiol (1985) 2016; 122:161-169. [PMID: 27856720 DOI: 10.1152/japplphysiol.00838.2016] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 11/08/2016] [Accepted: 11/14/2016] [Indexed: 01/11/2023] Open
Abstract
Micro-computed tomography (CT) enables three-dimensional (3D) imaging of complex soft tissue structures, but current protocols used to achieve this goal preclude cellular and molecular phenotyping of the tissue. Here we describe a radiolucent cryostage that permits micro-CT imaging of unfixed frozen human lung samples at an isotropic voxel size of (11 µm)3 under conditions where the sample is maintained frozen at -30°C during imaging. The cryostage was tested for thermal stability to maintain samples frozen up to 8 h. This report describes the methods used to choose the materials required for cryostage construction and demonstrates that whole genome mRNA integrity and expression are not compromised by exposure to micro-CT radiation and that the tissue can be used for immunohistochemistry. The new cryostage provides a novel method enabling integration of 3D tissue structure with cellular and molecular analysis to facilitate the identification of molecular determinants of disease. NEW & NOTEWORTHY The described micro-CT cryostage provides a novel way to study the three-dimensional lung structure preserved without the effects of fixatives while enabling subsequent studies of the cellular matrix composition and gene expression. This approach will, for the first time, enable researchers to study structural changes of lung tissues that occur with disease and correlate them with changes in gene or protein signatures.
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Affiliation(s)
- Dragoş M Vasilescu
- University of British Columbia, Centre for Heart Lung Innovation, Vancouver, British Columbia, Canada;
| | - André B Phillion
- Materials Science and Engineering, McMaster University, Hamilton, Ontario, Canada
| | - Naoya Tanabe
- University of British Columbia, Centre for Heart Lung Innovation, Vancouver, British Columbia, Canada
| | - Daisuke Kinose
- University of British Columbia, Centre for Heart Lung Innovation, Vancouver, British Columbia, Canada
| | | | - Jacob J Kantrowitz
- Section of Computational Biomedicine, Department of Medicine, Boston University Medical Center, Boston, Massachusetts
| | - Gang Liu
- Section of Computational Biomedicine, Department of Medicine, Boston University Medical Center, Boston, Massachusetts
| | - Hanqiao Liu
- Section of Computational Biomedicine, Department of Medicine, Boston University Medical Center, Boston, Massachusetts
| | - Nick Fishbane
- University of British Columbia, Centre for Heart Lung Innovation, Vancouver, British Columbia, Canada
| | - Stijn E Verleden
- Lung Transplant Unit, Department of Clinical and Experimental Medicine, KU Leuven, Leuven, Belgium
| | - Bart M Vanaudenaerde
- Lung Transplant Unit, Department of Clinical and Experimental Medicine, KU Leuven, Leuven, Belgium
| | - Marc Lenburg
- Section of Computational Biomedicine, Department of Medicine, Boston University Medical Center, Boston, Massachusetts
| | - Christopher S Stevenson
- Janssen Disease Interception Accelerator, Janssen Pharmaceutical Companies of Johnson and Johnson, Raritan, New Jersey; and
| | - Avrum Spira
- Section of Computational Biomedicine, Department of Medicine, Boston University Medical Center, Boston, Massachusetts
| | - Joel D Cooper
- Division of Thoracic Surgery, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Tillie-Louise Hackett
- University of British Columbia, Centre for Heart Lung Innovation, Vancouver, British Columbia, Canada
| | - James C Hogg
- University of British Columbia, Centre for Heart Lung Innovation, Vancouver, British Columbia, Canada
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29
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Kizhakke Puliyakote AS, Vasilescu DM, Newell JD, Wang G, Weibel ER, Hoffman EA. Morphometric differences between central vs. surface acini in A/J mice using high-resolution micro-computed tomography. J Appl Physiol (1985) 2016; 121:115-22. [PMID: 27174924 DOI: 10.1152/japplphysiol.00317.2016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 05/06/2016] [Indexed: 11/22/2022] Open
Abstract
Through interior tomography, high-resolution microcomputed tomography (μCT) systems provide the ability to nondestructively assess the pulmonary acinus at micron and submicron resolutions. With the application of systematic uniform random sampling (SURS) principles applied to in situ fixed, intact, ex vivo lungs, we have sought to characterize morphometric differences in central vs. surface acini to better understand how well surface acini reflect global acinar geometry. Lungs from six mice (A/J strain, 15-20 wk of age) were perfusion fixed in situ and imaged using a multiresolution μCT system (Micro XCT 400, Zeiss). With the use of lower-resolution whole lung images, SURS methods were used for identification of central and surface foci for high-resolution imaging. Acinar morphometric metrics included diameters, lengths, and branching angles for each alveolar duct and total path lengths from entrance of the acinus to the terminal alveolar sacs. In addition, acinar volume, alveolar surface area, and surface area/volume ratios were assessed. A generation-based analysis demonstrated that central acini have significantly smaller branch diameters at each generation with no significant increase in branch lengths. In addition to larger-diameter alveolar ducts, surface acini had significantly increased numbers of branches and terminal alveolar sacs. The total path lengths from the acinar entrance to the terminal nodes were found to be higher in the case of surface acini. Volumes and surface areas of surface acini are greater than central acini, but there were no differences in surface/volume ratios. In conclusion, there are significant structural differences between surface and central acini in the A/J mouse.
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Affiliation(s)
- Abhilash S Kizhakke Puliyakote
- Department of Radiology, University of Iowa, Iowa City, Iowa; Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa
| | | | - John D Newell
- Department of Radiology, University of Iowa, Iowa City, Iowa; Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa
| | - Ge Wang
- Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia; Department of Biomedical Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia
| | | | - Eric A Hoffman
- Department of Radiology, University of Iowa, Iowa City, Iowa; Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa; Department of Medicine, University of Iowa, Iowa City, Iowa;
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30
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Kizhakke Puliyakote AS, Vasilescu DM, Sen Sharma K, Wang G, Hoffman EA. A skeleton-tree-based approach to acinar morphometric analysis using microcomputed tomography with comparison of acini in young and old C57BL/6 mice. J Appl Physiol (1985) 2016; 120:1402-9. [PMID: 26940656 DOI: 10.1152/japplphysiol.00923.2015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 02/29/2016] [Indexed: 11/22/2022] Open
Abstract
We seek to establish a method using interior tomographic techniques (Xradia MicroXCT-400) for acinar morphometric analysis using the pathway center lines from micro X-ray computed tomographic (Micro-CT) images as the road map. Through the application of these techniques, we present a method to extend the atlas of murine lungs to acinar levels and present a comparison between two age groups of the C57BL/6 strain. Lungs fixed via vascular perfusion were scanned using high-resolution Micro-CT protocols. Individual acini were segmented, and skeletonized paths to alveolar sacs from the entrance to the acinus were formed. Morphometric parameters, including branch lengths, diameters, and branching angles, were generated. Six mice each, at two age groups (∼20 and ∼90 wk of age), were studied. Additive Gaussian noise (0 mean and SD 1, 2, 5, and 10) was used to test the robustness of the analytical method. Noise-based variations were within ±6 μm for branch lengths and ±5 μm for diameters. At a noise level of 10, errors increased. Branch diameters were less susceptible to noise than lengths. There was >95% center line overlap across all noise levels. The measurements obtained using the center lines as a road map were not affected by added noise. Acini from younger mice had smaller branch diameters and lengths at all generations without significant differences in branching angles. The relative distribution of volume in the alveolar ducts was similar across both age groups. The method has been demonstrated to be repeatable and robust to image noise and provides a new, nondestructive technique to assess and compare acinar morphometry quantitatively.
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Affiliation(s)
- Abhilash S Kizhakke Puliyakote
- Department of Radiology, University of Iowa, Iowa City, Iowa; Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa
| | | | - Kriti Sen Sharma
- Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia; and
| | - Ge Wang
- Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia; and Department of Biomedical Engineering, Virginia Polytechnic Institute and State University, Blacksburg, Virginia
| | - Eric A Hoffman
- Department of Radiology, University of Iowa, Iowa City, Iowa; Department of Biomedical Engineering, University of Iowa, Iowa City, Iowa; Department of Medicine, University of Iowa, Iowa City, Iowa;
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A simple method for the formalin fixation of lungs in toxicological pathology studies. ACTA ACUST UNITED AC 2015; 67:533-8. [DOI: 10.1016/j.etp.2015.08.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 08/26/2015] [Indexed: 11/29/2022]
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Smoktunowicz N, Alexander RE, Franklin L, Williams AE, Holman B, Mercer PF, Jarai G, Scotton CJ, Chambers RC. The anti-fibrotic effect of inhibition of TGFβ-ALK5 signalling in experimental pulmonary fibrosis in mice is attenuated in the presence of concurrent γ-herpesvirus infection. Dis Model Mech 2015; 8:1129-39. [PMID: 26138704 PMCID: PMC4582104 DOI: 10.1242/dmm.019984] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 06/26/2015] [Indexed: 02/06/2023] Open
Abstract
TGFβ-ALK5 pro-fibrotic signalling and herpesvirus infections have been implicated in the pathogenesis and exacerbation of pulmonary fibrosis. In this study we addressed the role of TGFβ-ALK5 signalling during the progression of fibrosis in a two-hit mouse model of murine γ-herpesvirus 68 (MHV-68) infection on the background of pre-existing bleomycin-induced pulmonary fibrosis. Assessment of total lung collagen levels in combination with ex vivo micro-computed tomography (µCT) analysis of whole lungs demonstrated that MHV-68 infection did not enhance lung collagen deposition in this two-hit model but led to a persistent and exacerbated inflammatory response. Moreover, µCT reconstruction and analysis of the two-hit model revealed distinguishing features of diffuse ground-glass opacities and consolidation superimposed on pre-existing fibrosis that were reminiscent of those observed in acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF). Virally-infected murine fibrotic lungs further displayed evidence of extensive inflammatory cell infiltration and increased levels of CCL2, TNFα, IL-1β and IL-10. Blockade of TGFβ-ALK5 signalling attenuated lung collagen accumulation in bleomycin-alone injured mice, but this anti-fibrotic effect was reduced in the presence of concomitant viral infection. In contrast, inhibition of TGFβ-ALK5 signalling in virally-infected fibrotic lungs was associated with reduced inflammatory cell aggregates and increased levels of the antiviral cytokine IFNγ. These data reveal newly identified intricacies for the TGFβ-ALK5 signalling axis in experimental lung fibrosis, with different outcomes in response to ALK5 inhibition depending on the presence of viral infection. These findings raise important considerations for the targeting of TGFβ signalling responses in the context of pulmonary fibrosis.
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Affiliation(s)
- Natalia Smoktunowicz
- Centre for Inflammation & Tissue Repair, University College London, London, WC1E 6JF, UK
| | - Robert E Alexander
- Centre for Inflammation & Tissue Repair, University College London, London, WC1E 6JF, UK
| | - Linda Franklin
- Centre for Inflammation & Tissue Repair, University College London, London, WC1E 6JF, UK
| | - Andrew E Williams
- Centre for Inflammation & Tissue Repair, University College London, London, WC1E 6JF, UK
| | - Beverley Holman
- Institute of Nuclear Medicine, University College London, NW1 2BU, UK
| | - Paul F Mercer
- Centre for Inflammation & Tissue Repair, University College London, London, WC1E 6JF, UK
| | - Gabor Jarai
- Novartis Institutes of Biomedical Research, Horsham, RH12 5AB, UK
| | - Chris J Scotton
- Centre for Inflammation & Tissue Repair, University College London, London, WC1E 6JF, UK
| | - Rachel C Chambers
- Centre for Inflammation & Tissue Repair, University College London, London, WC1E 6JF, UK
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Birkelbach B, Lutz D, Ruppert C, Henneke I, Lopez-Rodriguez E, Günther A, Ochs M, Mahavadi P, Knudsen L. Linking progression of fibrotic lung remodeling and ultrastructural alterations of alveolar epithelial type II cells in the amiodarone mouse model. Am J Physiol Lung Cell Mol Physiol 2015; 309:L63-75. [PMID: 25957292 DOI: 10.1152/ajplung.00279.2014] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 05/07/2015] [Indexed: 01/08/2023] Open
Abstract
Chronic injury of alveolar epithelial type II cells (AE2 cells) represents a key event in the development of lung fibrosis in animal models and in humans, such as idiopathic pulmonary fibrosis (IPF). Intratracheal delivery of amiodarone to mice results in a profound injury and macroautophagy-dependent apoptosis of AE2 cells. Increased autophagy manifested in AE2 cells by disturbances of the intracellular surfactant. Hence, we hypothesized that ultrastructural alterations of the intracellular surfactant pool are signs of epithelial stress correlating with the severity of fibrotic remodeling. With the use of design-based stereology, the amiodarone model of pulmonary fibrosis in mice was characterized at the light and ultrastructural level during progression. Mean volume of AE2 cells, volume of lamellar bodies per AE2 cell, and mean size of lamellar bodies were correlated to structural parameters reflecting severity of fibrosis like collagen content. Within 2 wk amiodarone leads to an increase in septal wall thickness and a decrease in alveolar numbers due to irreversible alveolar collapse associated with alveolar surfactant dysfunction. Progressive hypertrophy of AE2 cells and increase in mean individual size and total volume of lamellar bodies per AE2 cell were observed. A high positive correlation of these AE2 cell-related ultrastructural changes and the deposition of collagen fibrils within septal walls were established. Qualitatively, similar alterations could be found in IPF samples with mild to moderate fibrosis. We conclude that ultrastructural alterations of AE2 cells including the surfactant system are tightly correlated with the progression of fibrotic remodeling.
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Affiliation(s)
- Bastian Birkelbach
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany; Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Hannover, Germany; Member of the German Center for Lung Research (DZL), Germany
| | - Dennis Lutz
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany; Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Hannover, Germany; Member of the German Center for Lung Research (DZL), Germany
| | - Clemens Ruppert
- Department of Internal Medicine, Justus-Liebig-University Giessen, Universities of Giessen and Marburg Lung Center (UGMLC), Giessen, Germany; Member of the German Center for Lung Research (DZL), Germany
| | - Ingrid Henneke
- Department of Internal Medicine, Justus-Liebig-University Giessen, Universities of Giessen and Marburg Lung Center (UGMLC), Giessen, Germany; Member of the German Center for Lung Research (DZL), Germany
| | - Elena Lopez-Rodriguez
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany; Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Hannover, Germany; Member of the German Center for Lung Research (DZL), Germany
| | - Andreas Günther
- Department of Internal Medicine, Justus-Liebig-University Giessen, Universities of Giessen and Marburg Lung Center (UGMLC), Giessen, Germany; Member of the German Center for Lung Research (DZL), Germany; European IPF Network, Giessen, Germany; Excellence Cluster "Cardiopulmonary System ECCPS," Giessen, Germany; Lung Clinic Waldhof-Elgershausen, Greifenstein, Germany; and
| | - Matthias Ochs
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany; Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Hannover, Germany; Member of the German Center for Lung Research (DZL), Germany; REBIRTH Cluster of Excellence, Hannover, Germany
| | - Poornima Mahavadi
- Department of Internal Medicine, Justus-Liebig-University Giessen, Universities of Giessen and Marburg Lung Center (UGMLC), Giessen, Germany; Member of the German Center for Lung Research (DZL), Germany
| | - Lars Knudsen
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany; Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Hannover, Germany; Member of the German Center for Lung Research (DZL), Germany;
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Ochs M. Estimating structural alterations in animal models of lung emphysema. Is there a gold standard? Ann Anat 2013; 196:26-33. [PMID: 24268708 DOI: 10.1016/j.aanat.2013.10.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Revised: 10/07/2013] [Accepted: 10/12/2013] [Indexed: 01/08/2023]
Abstract
Chronic obstructive pulmonary disease (COPD) is one of the most common lung diseases. The major component of COPD, which affects the gas-exchanging parenchyma of the lung, emphysema, is characterized by destruction of alveolar septae leading to loss of functional surface, loss of alveoli and enlargement of remaining distal airspaces. These microstructural alterations can be modeled in animals and can be measured using stereological methods applied to imaging datasets. Many animal models of emphysema exist, but most of them are insufficiently characterized with respect to the underlying nature (e.g. destructive or developmental) and the degree of the structural alterations. The most popular parameter for assessment of emphysematous alterations, mean linear intercept length, has severe limitations. It can, therefore, not be recommended. Better design-based stereological alternatives exist but are less often applied, such as total volumes of parenchymal compartments (alveolar airspace, alveolar duct airspace, alveolar septum), total alveolar surface area, total alveolar number and mean alveolar size and its size variation. A prerequisite is the use of appropriate fixation, sampling, and specimen processing protocols. This article reviews the challenges of stereologic assessment of emphysematous alterations in the lung and illustrates possible strategies.
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Affiliation(s)
- Matthias Ochs
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany; Biomedical Research in Endstage and Obstructive Lung Disease Hannover (BREATH), Member of the German Center for Lung Research (DZL), Hannover, Germany; REBIRTH Cluster of Excellence, Hannover, Germany.
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35
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Counter WB, Wang IQ, Farncombe TH, Labiris NR. Airway and pulmonary vascular measurements using contrast-enhanced micro-CT in rodents. Am J Physiol Lung Cell Mol Physiol 2013; 304:L831-43. [DOI: 10.1152/ajplung.00281.2012] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Preclinical imaging allows pulmonary researchers to study lung disease and pulmonary drug delivery noninvasively and longitudinally in small animals. However, anatomically localizing a pathology or drug deposition to a particular lung region is not easily done. Thus, a detailed knowledge of the anatomical structure of small animal lungs is necessary for understanding disease progression and in addition would facilitate the analysis of the imaging data, mapping drug deposition and relating function to structure. In this study, contrast-enhanced micro-computed tomography (CT) of the lung produced high-resolution images that allowed for the characterization of the rodent airway and pulmonary vasculature. Contrast-enhanced micro-CT was used to visualize the airways and pulmonary vasculature in Sprague-Dawley rats (200–225 g) and BALB/c mice (20–25 g) postmortem. Segmented volumes from these images were processed to yield automated measurements of the airways and pulmonary vasculature. The diameters, lengths, and branching angles of the airway, arterial, and venous trees were measured and analyzed as a function of generation number and vessel diameter to establish rules that could be applied at all levels of tree hierarchy. In the rat, airway, arterial, and venous tress were measured down to the 20th, 16th, and 14th generation, respectively. In the mouse, airway, arterial, and venous trees were measured down to the 16th, 8th, and 7th generation, respectively. This structural information, catalogued in a rodent database, will increase our understanding of lung structure and will aid in future studies of the relationship between structure and function in animal models of disease.
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Affiliation(s)
- W. B. Counter
- Department of Medicine, McMaster University, Hamilton, Ontario, Canada
- Department of Medical Physics, McMaster University, Hamilton, Ontario, Canada
| | - I. Q. Wang
- Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - T. H. Farncombe
- Department of Radiology, McMaster University, Hamilton, Ontario, Canada; and
- Department of Nuclear Medicine, Hamilton Health Sciences, McMaster University, Hamilton, Ontario, Canada
| | - N. R. Labiris
- Department of Medicine, McMaster University, Hamilton, Ontario, Canada
- Department of Nuclear Medicine, Hamilton Health Sciences, McMaster University, Hamilton, Ontario, Canada
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36
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Hwang J, Kim M, Kim S, Lee J. Quantifying morphological parameters of the terminal branching units in a mouse lung by phase contrast synchrotron radiation computed tomography. PLoS One 2013; 8:e63552. [PMID: 23704918 PMCID: PMC3660418 DOI: 10.1371/journal.pone.0063552] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Accepted: 04/03/2013] [Indexed: 01/17/2023] Open
Abstract
An effective technique of phase contrast synchrotron radiation computed tomography was established for the quantitative analysis of the microstructures in the respiratory zone of a mouse lung. Heitzman’s method was adopted for the whole-lung sample preparation, and Canny’s edge detector was used for locating the air-tissue boundaries. This technique revealed detailed morphology of the respiratory zone components, including terminal bronchioles and alveolar sacs, with sufficiently high resolution of 1.74 µm isotropic voxel size. The technique enabled visual inspection of the respiratory zone components and comprehension of their relative positions in three dimensions. To check the method’s feasibility for quantitative imaging, morphological parameters such as diameter, surface area and volume were measured and analyzed for sixteen randomly selected terminal branching units, each consisting of a terminal bronchiole and a pair of succeeding alveolar sacs. The four types of asymmetry ratios concerning alveolar sac mouth diameter, alveolar sac surface area, and alveolar sac volume are measured. This is the first ever finding of the asymmetry ratio for the terminal bronchioles and alveolar sacs, and it is noteworthy that an appreciable degree of branching asymmetry was observed among the alveolar sacs at the terminal end of the airway tree, despite the number of samples was small yet. The series of efficient techniques developed and confirmed in this study, from sample preparation to quantification, is expected to contribute to a wider and exacter application of phase contrast synchrotron radiation computed tomography to a variety of studies.
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Affiliation(s)
- Jeongeun Hwang
- School of Interdisciplinary Bioscience and Bioengineering, POSTECH, Pohang, Republic of Korea
| | - Miju Kim
- School of Interdisciplinary Bioscience and Bioengineering, POSTECH, Pohang, Republic of Korea
| | - Seunghwan Kim
- Department of Physics, POSTECH, Pohang, Republic of Korea
- Institute for Edge of Theoretical Science, POSTECH, Pohang, Republic of Korea
| | - Jinwon Lee
- Department of Mechanical Engineering, POSTECH, Pohang, Republic of Korea
- * E-mail:
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37
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Bronchopulmonary dysplasia in a double-hit mouse model induced by intrauterine hypoxia and postnatal hyperoxia: closer to clinical features? Ann Anat 2013; 195:351-358. [PMID: 23684450 DOI: 10.1016/j.aanat.2013.02.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Revised: 02/22/2013] [Accepted: 02/25/2013] [Indexed: 01/21/2023]
Abstract
Despite increased survival of very preterm newborns, bronchopulmonary dysplasia (BPD) remains a major threat, as it affects long-term pulmonary function and neurodevelopmental outcome. Recent research focused on mechanisms of lung repair. Animal models of BPD in term rodents use postnatal hyperoxia in order to mimic features observed in very preterm human neonates: reduced alveolarization and impaired septal architecture without profound inflammatory changes. In contrast, BPD in very preterm human neonates involves prenatal hits e.g. infections and growth restriction plus postnatal ventilation. BPD induced in rodents by postnatal hyperoxia also exhibits reduced alveolarization however without septal pathology but with marked inflammation. We therefore aimed to establish an animal model combining prenatal growth restriction (FiO₂ 0.1 for 4 days) with postnatal hyperoxia (FiO₂ 0.7 for 2 weeks). In double-hit mice the development was retarded: body weight and length, lung and brain weight were significantly reduced by day P14 compared with normoxic controls. Histomorphometric analysis revealed reduced alveolarization and increased septal thickness without pronounced inflammatory lesions. A down-regulation of SftpB and SftpC genes was observed in double-hit animals compared with controls. Thus, we established a new model of BPD using pre- and postnatal hits.
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Kumar H, Vasilescu DM, Yin Y, Hoffman EA, Tawhai MH, Lin CL. Multiscale imaging and registration-driven model for pulmonary acinar mechanics in the mouse. J Appl Physiol (1985) 2013; 114:971-8. [PMID: 23412896 DOI: 10.1152/japplphysiol.01136.2012] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A registration-based multiscale method to obtain a deforming geometric model of mouse acinus is presented. An intact mouse lung was fixed by means of vascular perfusion at a hydrostatic inflation pressure of 20 cmH(2)O. Microcomputed tomography (μCT) scans were obtained at multiple resolutions. Substructural morphometric analysis of a complete acinus was performed by computing a surface-to-volume (S/V) ratio directly from the 3D reconstruction of the acinar geometry. A geometric similarity is observed to exist in the acinus where S/V is approximately preserved anywhere in the model. Using multiscale registration, the shape of the acinus at an elevated inflation pressure of 25 cmH(2)O is estimated. Changes in the alveolar geometry suggest that the deformation within the acinus is not isotropic. In particular, the expansion of the acinus (from 20 to 25 cmH(2)O) is accompanied by an increase in both surface area and volume in such a way that the S/V ratio is not significantly altered. The developed method forms a useful tool in registration-driven fluid and solid mechanics studies as displacement of the alveolar wall becomes available in a discrete sense.
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Affiliation(s)
- Haribalan Kumar
- Department of Mechanical and Industrial Engineering, The University of Iowa, Iowa City, IA 52242-1527, USA
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Vasilescu DM, Klinge C, Knudsen L, Yin L, Wang G, Weibel ER, Ochs M, Hoffman EA. Stereological assessment of mouse lung parenchyma via nondestructive, multiscale micro-CT imaging validated by light microscopic histology. J Appl Physiol (1985) 2012; 114:716-24. [PMID: 23264542 DOI: 10.1152/japplphysiol.00855.2012] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Quantitative assessment of the lung microstructure using standard stereological methods such as volume fractions of tissue, alveolar surface area, or number of alveoli, are essential for understanding the state of normal and diseased lung. These measures are traditionally obtained from histological sections of the lung tissue, a process that ultimately destroys the three-dimensional (3-D) anatomy of the tissue. In comparison, a novel X-ray-based imaging method that allows nondestructive sectioning and imaging of fixed lungs at multiple resolutions can overcome this limitation. Scanning of the whole lung at high resolution and subsequent regional sampling at ultrahigh resolution without physically dissecting the organ allows the application of design-based stereology for assessment of the whole lung structure. Here we validate multiple stereological estimates performed on micro-computed tomography (μCT) images by comparing them with those obtained via conventional histology on the same mouse lungs. We explore and discuss the potentials and limitations of the two approaches. Histological examination offers higher resolution and the qualitative differentiation of tissues by staining, but ultimately loses 3-D tissue relationships, whereas μCT allows for the integration of morphometric data with the spatial complexity of lung structure. However, μCT has limited resolution satisfactory for the sterological estimates presented in this study but not for differentiation of tissues. We conclude that introducing stereological methods in μCT studies adds value by providing quantitative information on internal structures while not curtailing more complex approaches to the study of lung architecture in the context of physiological or pathological studies.
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40
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Assessment of morphometry of pulmonary acini in mouse lungs by nondestructive imaging using multiscale microcomputed tomography. Proc Natl Acad Sci U S A 2012; 109:17105-10. [PMID: 23027935 DOI: 10.1073/pnas.1215112109] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Establishing the 3D architecture and morphometry of the intact pulmonary acinus is an essential step toward a more complete understanding of the relationship of lung structure and function. We combined a special fixation method with a unique volumetric nondestructive imaging technique and image processing tools to separate individual acini in the mouse lung. Interior scans of the parenchyma at a resolution of 2 µm enabled the reconstruction and quantitative study of whole acini by image analysis and stereologic methods, yielding data characterizing the 3D morphometry of the pulmonary acinus. The 3D reconstructions compared well with the architecture of silicon rubber casts of mouse acini. The image-based segmentation of individual acini allowed the computation of acinar volume and surface area, as well as estimation of the number of alveoli per acinus using stereologic methods. The acinar morphometry of male C57BL/6 mice age 12 wk and 91 wk was compared. Significant increases in all parameters as a function of age suggest a continuous change of the lung morphometry, with an increase in alveoli beyond what has been previously viewed as the maturation phase of the animals. Our image analysis methods open up opportunities for defining and quantitatively assessing the acinar structure in healthy and diseased lungs. The methods applied here to mice can be adjusted for the study of similarly prepared human lungs.
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Kellner M, Heidrich M, Beigel R, Lorbeer RA, Knudsen L, Ripken T, Heisterkamp A, Meyer H, Kühnel MP, Ochs M. Imaging of the mouse lung with scanning laser optical tomography (SLOT). J Appl Physiol (1985) 2012; 113:975-83. [DOI: 10.1152/japplphysiol.00026.2012] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The current study focuses on the use of scanning laser optical tomography (SLOT) in imaging of the mouse lung ex vivo. SLOT is a highly efficient fluorescence microscopy technique allowing rapid scanning of samples of a size of several millimeters, thus enabling volumetric visualization by using intrinsic contrast mechanisms of previously fixed lung lobes. Here, we demonstrate the imaging of airways, blood vessels, and parenchyma from whole, optically cleared mouse lung lobes with a resolution down to the level of single alveoli using absorption and autofluorescence scan modes. The internal structure of the lung can then be analyzed nondestructively and quantitatively in three-dimensional datasets in any preferred planar orientation. Moreover, the procedure preserves the microscopic structure of the lung and allows for subsequent correlative histologic studies. In summary, the current study has shown that SLOT is a valuable technique to study the internal structure of the mouse lung.
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Affiliation(s)
- Manuela Kellner
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
| | - Marko Heidrich
- Biomedical Optics Department, Laser Zentrum Hannover e.V., Hannover, Germany
| | - Rebecca Beigel
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
- REBIRTH Cluster of Excellence, Hannover, Germany
| | | | - Lars Knudsen
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
- German Center for Lung Research, Hannover, Germany
| | - Tammo Ripken
- Biomedical Optics Department, Laser Zentrum Hannover e.V., Hannover, Germany
- REBIRTH Cluster of Excellence, Hannover, Germany
| | - Alexander Heisterkamp
- REBIRTH Cluster of Excellence, Hannover, Germany
- German Center for Lung Research, Hannover, Germany
- Institute of Applied Optics, Friedrich-Schiller-University Jena, Jena, Germany; and
| | - Heiko Meyer
- Biomedical Optics Department, Laser Zentrum Hannover e.V., Hannover, Germany
- REBIRTH Cluster of Excellence, Hannover, Germany
- Department of Cardiothoracic, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany
| | - Mark Philipp Kühnel
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
| | - Matthias Ochs
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
- REBIRTH Cluster of Excellence, Hannover, Germany
- German Center for Lung Research, Hannover, Germany
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