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Tav C, Fournier É, Fournier M, Khadangi F, Baguette A, Côté MC, Silveira MAD, Bérubé-Simard FA, Bourque G, Droit A, Bilodeau S. Glucocorticoid stimulation induces regionalized gene responses within topologically associating domains. Front Genet 2023; 14:1237092. [PMID: 37576549 PMCID: PMC10413275 DOI: 10.3389/fgene.2023.1237092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 07/07/2023] [Indexed: 08/15/2023] Open
Abstract
Transcription-factor binding to cis-regulatory regions regulates the gene expression program of a cell, but occupancy is often a poor predictor of the gene response. Here, we show that glucocorticoid stimulation led to the reorganization of transcriptional coregulators MED1 and BRD4 within topologically associating domains (TADs), resulting in active or repressive gene environments. Indeed, we observed a bias toward the activation or repression of a TAD when their activities were defined by the number of regions gaining and losing MED1 and BRD4 following dexamethasone (Dex) stimulation. Variations in Dex-responsive genes at the RNA levels were consistent with the redistribution of MED1 and BRD4 at the associated cis-regulatory regions. Interestingly, Dex-responsive genes without the differential recruitment of MED1 and BRD4 or binding by the glucocorticoid receptor were found within TADs, which gained or lost MED1 and BRD4, suggesting a role of the surrounding environment in gene regulation. However, the amplitude of the response of Dex-regulated genes was higher when the differential recruitment of the glucocorticoid receptor and transcriptional coregulators was observed, reaffirming the role of transcription factor-driven gene regulation and attributing a lesser role to the TAD environment. These results support a model where a signal-induced transcription factor induces a regionalized effect throughout the TAD, redefining the notion of direct and indirect effects of transcription factors on target genes.
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Affiliation(s)
- Christophe Tav
- Centre de Recherche du CHU de Québec—Université Laval, Axe Oncologie, Québec, QC, Canada
- Centre de Recherche sur le Cancer de l’Université Laval, Québec, QC, Canada
- Centre de Recherche en Données Massives de l’Université Laval, Québec, QC, Canada
| | - Éric Fournier
- Centre de Recherche du CHU de Québec—Université Laval, Axe Oncologie, Québec, QC, Canada
- Centre de Recherche sur le Cancer de l’Université Laval, Québec, QC, Canada
- Centre de Recherche en Données Massives de l’Université Laval, Québec, QC, Canada
| | - Michèle Fournier
- Centre de Recherche du CHU de Québec—Université Laval, Axe Oncologie, Québec, QC, Canada
- Centre de Recherche sur le Cancer de l’Université Laval, Québec, QC, Canada
| | - Fatemeh Khadangi
- Centre de Recherche du CHU de Québec—Université Laval, Axe Oncologie, Québec, QC, Canada
- Centre de Recherche sur le Cancer de l’Université Laval, Québec, QC, Canada
| | - Audrey Baguette
- Department of Human Genetics, Faculty of Medicine, McGill University, Montréal, QC, Canada
| | - Maxime C. Côté
- Centre de Recherche du CHU de Québec—Université Laval, Axe Oncologie, Québec, QC, Canada
- Centre de Recherche sur le Cancer de l’Université Laval, Québec, QC, Canada
| | - Maruhen A. D. Silveira
- Centre de Recherche du CHU de Québec—Université Laval, Axe Oncologie, Québec, QC, Canada
- Centre de Recherche sur le Cancer de l’Université Laval, Québec, QC, Canada
| | - Félix-Antoine Bérubé-Simard
- Centre de Recherche du CHU de Québec—Université Laval, Axe Oncologie, Québec, QC, Canada
- Centre de Recherche sur le Cancer de l’Université Laval, Québec, QC, Canada
| | - Guillaume Bourque
- Department of Human Genetics, Faculty of Medicine, McGill University, Montréal, QC, Canada
- Canadian Center for Computational Genomics, McGill University, Montréal, QC, Canada
| | - Arnaud Droit
- Centre de Recherche sur le Cancer de l’Université Laval, Québec, QC, Canada
- Centre de Recherche en Données Massives de l’Université Laval, Québec, QC, Canada
- Centre de Recherche du CHU de Québec—Université Laval, Axe Endocrinologie et Néphrologie, Québec, QC, Canada
- Département de Médecine Moléculaire, Faculté de Médecine, Université Laval, Québec, QC, Canada
| | - Steve Bilodeau
- Centre de Recherche du CHU de Québec—Université Laval, Axe Oncologie, Québec, QC, Canada
- Centre de Recherche sur le Cancer de l’Université Laval, Québec, QC, Canada
- Centre de Recherche en Données Massives de l’Université Laval, Québec, QC, Canada
- Département de Biologie Moléculaire, Biochimie Médicale et Pathologie, Faculté de Médecine, Université Laval, Québec, QC, Canada
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Boucher M, Dufour-Mailhot A, Tremblay-Pitre S, Khadangi F, Rojas-Ruiz A, Henry C, Bossé Y. In mice of both sexes, repeated contractions of smooth muscle in vivo greatly enhance the response of peripheral airways to methacholine. Respir Physiol Neurobiol 2022; 304:103938. [PMID: 35716869 DOI: 10.1016/j.resp.2022.103938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 05/10/2022] [Accepted: 06/12/2022] [Indexed: 10/18/2022]
Abstract
BALB/c mice from both sexes underwent one of two nebulized methacholine challenges that were preceded by a period of 20 min either with or without tone induced by repeated contractions of the airway smooth muscle. Impedance was monitored throughout and the constant phase model was used to dissociate the impact of tone on conducting airways (RN - Newtonian resistance) versus the lung periphery (G and H - tissue resistance and elastance). The effect of tone on smooth muscle contractility was also tested on excised tracheas. While tone markedly potentiated the methacholine-induced gains in H and G in both sexes, the gain in RN was only potentiated in males. The contractility of female and male tracheas was also potentiated by tone. Inversely, the methacholine-induced gain in hysteresivity (G/H) was mitigated by tone in both sexes. Therefore, the tone-induced muscle hypercontractility impacts predominantly the lung periphery in vivo, but also promotes further airway narrowing in males while protecting against narrowing heterogeneity in both sexes.
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Affiliation(s)
- Magali Boucher
- Institut Universitaire de Cardiologie et de Pneumologie de Québec - Université Laval, Québec, Canada
| | - Alexis Dufour-Mailhot
- Institut Universitaire de Cardiologie et de Pneumologie de Québec - Université Laval, Québec, Canada
| | - Sophie Tremblay-Pitre
- Institut Universitaire de Cardiologie et de Pneumologie de Québec - Université Laval, Québec, Canada
| | - Fatemeh Khadangi
- Institut Universitaire de Cardiologie et de Pneumologie de Québec - Université Laval, Québec, Canada
| | - Andrés Rojas-Ruiz
- Institut Universitaire de Cardiologie et de Pneumologie de Québec - Université Laval, Québec, Canada
| | - Cyndi Henry
- Institut Universitaire de Cardiologie et de Pneumologie de Québec - Université Laval, Québec, Canada
| | - Ynuk Bossé
- Institut Universitaire de Cardiologie et de Pneumologie de Québec - Université Laval, Québec, Canada.
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Khadangi F, Tremblay-Pitre S, Dufour-Mailhot A, Rojas-Ruiz AB, Boucher M, Henry C, Fereydoonzad L, Brunet D, Robichaud A, Bossé Y. Sensitive physiological readouts to evaluate countermeasures for lipopolysaccharide-induced lung alterations in mice. Am J Physiol Lung Cell Mol Physiol 2022; 323:L107-L120. [PMID: 35670484 DOI: 10.1152/ajplung.00073.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Despite decades of research, studies investigating the physiological alterations caused by an acute bout of inflammation induced by exposing the lung to lipopolysaccharide have yielded inconsistent results. This can be attributed to small effects and/or a lack of fitted physiological testing. Herein, a comprehensive investigation of lung mechanics was conducted in 270 male C57BL/6 mice at 24, 48 or 96 h after an intranasal exposure to saline or lipopolysaccharide at either 1 or 3 mg/kg (30 mice per group). Traditional techniques that probe the lung using small-amplitude perturbations (i.e., oscillometry) were used, together with less conventional and new techniques that probe the lung using maneuvers of large amplitudes. The latter include a partial and a full-range pressure-volume maneuvers to measure quasi-static elastance, compliance, total lung volume, vital capacity and residual volume. The results demonstrate that lung mechanics assessed by oscillometry was only slightly affected by lipopolysaccharide, confirming previous findings. In contradistinction, lipopolysaccharide markedly altered mechanics when the lung was probed with maneuvers of large amplitudes. With the dose of 3 mg/kg at the peak of inflammation (48 h post-exposure), lipopolysaccharide increased quasi-static elastance by 26.7% (p<0.0001), and decreased compliance by 34.5% (p<0.0001). It also decreased lung volumes, including total lung capacity, vital capacity and residual volume by 33.3%, 30.5% and 43.3%, respectively (all p<0.0001). These newly reported physiological alterations represent sensitive outcomes to efficiently evaluate countermeasures (e.g., drugs) in the context of several lung diseases.
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Affiliation(s)
- Fatemeh Khadangi
- Institut Universitaire de Cardiologie et de Pneumologie de Quebec, Université Laval, Québec, Canada
| | - Sophie Tremblay-Pitre
- Institut Universitaire de Cardiologie et de Pneumologie de Quebec, Université Laval, Québec, Canada
| | - Alexis Dufour-Mailhot
- Institut Universitaire de Cardiologie et de Pneumologie de Quebec, Université Laval, Québec, Canada
| | - Andrés Bruno Rojas-Ruiz
- Institut Universitaire de Cardiologie et de Pneumologie de Quebec, Université Laval, Québec, Canada
| | - Magali Boucher
- Institut Universitaire de Cardiologie et de Pneumologie de Quebec, Université Laval, Québec, Canada
| | - Cyndi Henry
- Institut Universitaire de Cardiologie et de Pneumologie de Quebec, Université Laval, Québec, Canada
| | | | - David Brunet
- SCIREQ - Scientific Respiratory Equipment Inc., Montreal, Canada
| | | | - Ynuk Bossé
- Institut Universitaire de Cardiologie et de Pneumologie de Quebec, Université Laval, Québec, Canada
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Boucher M, Henry C, Khadangi F, Dufour-Mailhot A, Tremblay-Pitre S, Fereydoonzad L, Brunet D, Robichaud A, Bossé Y. Effects of airway smooth muscle contraction and inflammation on lung tissue compliance. Am J Physiol Lung Cell Mol Physiol 2021; 322:L294-L304. [PMID: 34936511 DOI: 10.1152/ajplung.00384.2021] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
There are renewed interests in using the parameter K of Salazar-Knowles' equation to assess lung tissue compliance. K either decreases or increases when the lung's parenchyma stiffens or loosens, respectively. However, whether K is affected by other common features of respiratory diseases, such as inflammation and airway smooth muscle (ASM) contraction, is unknown. Herein, male C57BL/6 mice were treated intranasally with either saline or lipopolysaccharide (LPS) at 1 mg/Kg to induce pulmonary inflammation. They were then subjected to either a multiple or a single-dose challenge with methacholine to activate ASM to different degrees. A quasi-static pressure-driven partial pressure-volume maneuver was performed before and after methacholine. The Salazar-Knowles' equation was then fitted to the deflation limb of the P-V loop to obtain K, as well as the parameter A, an estimate of lung volume (inspiratory capacity). The fitted curve was also used to derive the quasi-static elastance (Est) at 5 cmH2O. The results demonstrate that LPS and both methacholine challenges increased Est. LPS also decreased A, but did not affect K. In contradistinction, methacholine decreased both A and K in the multiple-dose challenge, while it decreased K but not A in the single-dose challenge. These results suggest that LPS increases Est by reducing the open lung volume (A) and without affecting tissue compliance (K), while methacholine increases Est by decreasing tissue compliance with or without affecting lung volume. We conclude that lung tissue compliance, assessed using the parameter K of Salazar-Knowles' equation, is insensitive to inflammation but sensitive to ASM contraction.
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Affiliation(s)
- Magali Boucher
- Institut Universitaire de Cardiologie et de Pneumologie de Quebec, Université Laval, Quebec, Canada
| | - Cyndi Henry
- Institut Universitaire de Cardiologie et de Pneumologie de Quebec, Université Laval, Quebec, Canada
| | - Fatemeh Khadangi
- Institut Universitaire de Cardiologie et de Pneumologie de Quebec, Université Laval, Quebec, Canada
| | - Alexis Dufour-Mailhot
- Institut Universitaire de Cardiologie et de Pneumologie de Quebec, Université Laval, Quebec, Canada
| | - Sophie Tremblay-Pitre
- Institut Universitaire de Cardiologie et de Pneumologie de Quebec, Université Laval, Quebec, Canada
| | | | - David Brunet
- SCIREQ - Scientific Respiratory Equipment Inc., Montreal, Canada
| | | | - Ynuk Bossé
- Institut Universitaire de Cardiologie et de Pneumologie de Quebec, Université Laval, Quebec, Canada
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Ganouna-Cohen G, Khadangi F, Marcouiller F, Bossé Y, Joseph V. Additive effects of orchiectomy and intermittent hypoxia on lung mechanics and inflammation in C57BL/6J male mice. Exp Physiol 2021; 107:68-81. [PMID: 34761830 DOI: 10.1113/ep090050] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 11/05/2021] [Indexed: 01/01/2023]
Abstract
NEW FINDINGS What is the central question of this study? Does endogenous testosterone modulate the consequences of intermittent hypoxia (IH) in the lungs of male mice? What is the main finding and its importance? Orchiectomized mice exposed to IH develop a pattern that is similar to emphysema or obstructive lung disease with elevated lung volumes, low pulmonary elastance during a methacholine challenge test and high counts of lymphocytes in bronchoalveolar lavages. Since low testosterone levels and other respiratory diseases are common in sleep apnoea, there is a clear clinical relevance to these results. ABSTRACT We tested the hypothesis that low testosterone levels modulate the pulmonary responses to intermittent hypoxia (IH; used as a model of sleep apnoea (SA)) in male mice. We used intact (SHAM) or orchiectomized (ORX) mice exposed to IH for 14 days (12 h/day, 10 cycles/h, 6% oxygen) or to normoxia (Nx). We first measured ventilation and metabolic rates in freely behaving mice (whole-body plethysmography) and then respiratory mechanics in tracheotomized mice (flexiVent). We assessed the respiratory system resistance and elastance (Ers ), Newtonian resistance (resistance of the large airways), tissue damping and tissue elastance (H) under baseline conditions and during a methacholine challenge test. We also measured the quasi-static compliance and inspiratory capacity with partial pressure-volume loops. Finally, inflammatory cells were counted in the broncho-alveolar lavage (BAL) and we measured lung volume by water displacement. ORX-IH mice had higher tidal volume, inspiratory capacity and lung volume compared to the other groups, but showed signs of low efficiency of O2 exchange rate relative to minute ventilation. During the methacholine challenge, orchiectomy decreased the values of most mechanical parameters and IH reduced Ers and H leading to very low values in ORX-IH mice. Finally, the total number of cells and the number of lymphocytes in BAL were both increased by IH in ORX mice. Since reduced lung elasticity, low O2 extraction, increased lung volumes and inflammation are signs of emphysematous lung disease, we conclude that testosterone might prevent lung emphysema during IH exposures.
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Affiliation(s)
- Gauthier Ganouna-Cohen
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie du Québec, Université Laval, Québec, QC, Canada
| | - Fatemeh Khadangi
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie du Québec, Université Laval, Québec, QC, Canada
| | - François Marcouiller
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie du Québec, Université Laval, Québec, QC, Canada
| | - Ynuk Bossé
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie du Québec, Université Laval, Québec, QC, Canada
| | - Vincent Joseph
- Centre de Recherche de l'Institut Universitaire de Cardiologie et de Pneumologie du Québec, Université Laval, Québec, QC, Canada
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Boucher M, Henry C, Khadangi F, Dufour-Mailhot A, Bossé Y. Double-chamber plethysmography versus oscillometry to detect baseline airflow obstruction in a model of asthma in two mouse strains. Exp Lung Res 2021; 47:390-401. [PMID: 34541979 DOI: 10.1080/01902148.2021.1979693] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
AIM OF THE STUDY The current gold standard to assess respiratory mechanics in mice is oscillometry, a technique from which several readouts of the respiratory system can be deduced, such as resistance and elastance. However, these readouts are often not altered in mouse models of asthma. This is in stark contrast with humans, where asthma is generally associated with alterations when assessed by either oscillometry or other techniques. In the present study, we have used double-chamber plethysmography (DCP) to evaluate the breathing pattern and the degree of airflow obstruction in a mouse model of asthma. MATERIALS AND METHODS Female C57BL/6 and BALB/c mice were studied at day 1 using DCP, as well as at day 11 using both DCP and oscillometry following a once-daily exposure to either house-dust mite (HDM) or saline for 10 consecutive days. RESULTS All DCP readouts used to describe either the breathing pattern (e.g., tidal volume and breathing frequency) or the degree of airflow obstruction (e.g., specific airway resistance) were different between mouse strains at day 1. Most of these strain differences persisted at day 11. Most oscillometric readouts (e.g., respiratory system resistance and elastance) were also different between strains. Changes caused by HDM were obvious with DCP, including decreases in tidal volume, minute ventilation, inspiratory time and mid-tidal expiratory flow and an increase in specific airway resistance. HDM also caused some strain specific alterations in breathing pattern, including increases in expiratory time and end inspiratory pause, which were only observed in C57BL/6 mice. Oscillometry also detected a small but significant increase in tissue elastance in HDM versus saline-exposed mice. CONCLUSIONS DCP successfully identified differences between C57BL/6 and BALB/c mice, as well as alterations in mice from both strains exposed to HDM. We conclude that, depending on the study purpose, DCP may sometimes outweigh oscillometry.
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Affiliation(s)
- Magali Boucher
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Quebec City, Canada
| | - Cyndi Henry
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Quebec City, Canada
| | - Fatemeh Khadangi
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Quebec City, Canada
| | - Alexis Dufour-Mailhot
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Quebec City, Canada
| | - Ynuk Bossé
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Quebec City, Canada
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Boucher M, Henry C, Dufour-Mailhot A, Khadangi F, Bossé Y. Smooth Muscle Hypocontractility and Airway Normoresponsiveness in a Mouse Model of Pulmonary Allergic Inflammation. Front Physiol 2021; 12:698019. [PMID: 34267677 PMCID: PMC8277197 DOI: 10.3389/fphys.2021.698019] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 06/04/2021] [Indexed: 01/25/2023] Open
Abstract
The contractility of airway smooth muscle (ASM) is labile. Although this feature can greatly modulate the degree of airway responsiveness in vivo, the extent by which ASM's contractility is affected by pulmonary allergic inflammation has never been compared between strains of mice exhibiting a different susceptibility to develop airway hyperresponsiveness (AHR). Herein, female C57BL/6 and BALB/c mice were treated intranasally with either saline or house dust mite (HDM) once daily for 10 consecutive days to induce pulmonary allergic inflammation. The doses of HDM were twice greater in the less susceptible C57BL/6 strain. All outcomes, including ASM contractility, were measured 24 h after the last HDM exposure. As expected, while BALB/c mice exposed to HDM became hyperresponsive to a nebulized challenge with methacholine in vivo, C57BL/6 mice remained normoresponsive. The lack of AHR in C57BL/6 mice occurred despite exhibiting more than twice as much inflammation than BALB/c mice in bronchoalveolar lavages, as well as similar degrees of inflammatory cell infiltrates within the lung tissue, goblet cell hyperplasia and thickening of the epithelium. There was no enlargement of ASM caused by HDM exposure in either strain. Unexpectedly, however, excised tracheas derived from C57BL/6 mice exposed to HDM demonstrated a decreased contractility in response to both methacholine and potassium chloride, while tracheas from BALB/c mice remained normocontractile following HDM exposure. These results suggest that the lack of AHR in C57BL/6 mice, at least in an acute model of HDM-induced pulmonary allergic inflammation, is due to an acquired ASM hypocontractility.
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Affiliation(s)
- Magali Boucher
- Institut Universitaire de Cardiologie et de Pneumologie de Québec - Université Laval, Québec, QC, Canada
| | - Cyndi Henry
- Institut Universitaire de Cardiologie et de Pneumologie de Québec - Université Laval, Québec, QC, Canada
| | - Alexis Dufour-Mailhot
- Institut Universitaire de Cardiologie et de Pneumologie de Québec - Université Laval, Québec, QC, Canada
| | - Fatemeh Khadangi
- Institut Universitaire de Cardiologie et de Pneumologie de Québec - Université Laval, Québec, QC, Canada
| | - Ynuk Bossé
- Institut Universitaire de Cardiologie et de Pneumologie de Québec - Université Laval, Québec, QC, Canada
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Ganouna‐Cohen G, Khadangi F, Marcouiller F, Bosse Y, Joseph V. Pulmonary alterations induced by intermittent hypoxia in castrated C57BL/6J male mice. FASEB J 2021. [DOI: 10.1096/fasebj.2021.35.s1.01579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
| | - Fatemeh Khadangi
- Institut Universitaire de Cardiologie et de Pneumologie de Québec (IUCPQ)QuébecQC
| | - François Marcouiller
- Institut Universitaire de Cardiologie et de Pneumologie de Québec (IUCPQ)QuébecQC
| | - Ynuk Bosse
- Institut Universitaire de Cardiologie et de Pneumologie de Québec (IUCPQ)QuébecQC
| | - Vincent Joseph
- Institut Universitaire de Cardiologie et de Pneumologie de Québec (IUCPQ)QuébecQC
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Dufour-Mailhot A, Boucher M, Henry C, Khadangi F, Tremblay-Pitre S, Clisson M, Beaudoin J, Clavel MA, Bossé Y. Flexibility of microstructural adaptations in airway smooth muscle. J Appl Physiol (1985) 2021; 130:1555-1561. [PMID: 33856257 DOI: 10.1152/japplphysiol.00894.2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The airway smooth muscle undergoes an elastic transition during a sustained contraction, characterized by a gradual decrease in hysteresivity caused by a relatively greater rate of increase in elastance than resistance. We recently demonstrated that these mechanical changes are more likely to persist after a large strain when they are acquired in dynamic versus static conditions; as if the microstructural adaptations liable for the elastic transition are more flexible when they evolve in dynamic conditions. The extent of this flexibility is undefined. Herein, contracted ovine tracheal smooth muscle strips were kept in dynamic conditions simulating tidal breathing (sinusoidal length oscillations at 5% amplitude) and then subjected to simulated deep inspirations (DI). Each DI was straining the muscle by either 10%, 20%, or 30% and was imposed at either 2, 5, 10, or 30 min after the preceding DI. The goal was to assess whether and the extent by which the time-dependent decrease in hysteresivity is preserved following the DI. The results show that the time-dependent decrease in hysteresivity seen pre-DI was preserved after a strain of 10%, but not after a strain of 20% or 30%. This suggests that the microstructural adaptations liable for the elastic transition withstood a strain at least twofold greater than the oscillating strain that pertained during their evolution (10% vs. 5%). We propose that a muscle adapting in dynamic conditions forges microstructures exhibiting a substantial degree of flexibility.NEW & NOTEWORTHY This study confirms that airway smooth muscle undergoes an elastic transition during a sustained contraction even when it operates in dynamic conditions simulating breathing at tidal volume. It also demonstrates that the microstructural adaptations liable for this elastic transition withstand a strain that is at least twice as large as the oscillating strain that pertains during their evolution. This degree of flexibility might be an asset with major significant impact for a tissue such as the airway smooth muscle that displays an everchanging shape due to breathing.
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Affiliation(s)
- Alexis Dufour-Mailhot
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Quebec, Canada
| | - Magali Boucher
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Quebec, Canada
| | - Cyndi Henry
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Quebec, Canada
| | - Fatemeh Khadangi
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Quebec, Canada
| | - Sophie Tremblay-Pitre
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Quebec, Canada
| | - Marine Clisson
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Quebec, Canada
| | - Jonathan Beaudoin
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Quebec, Canada
| | - Marie-Annick Clavel
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Quebec, Canada
| | - Ynuk Bossé
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Quebec, Canada
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Khadangi F, Forgues AS, Tremblay-Pitre S, Dufour-Mailhot A, Henry C, Boucher M, Beaulieu MJ, Morissette M, Fereydoonzad L, Brunet D, Robichaud A, Bossé Y. Intranasal versus intratracheal exposure to lipopolysaccharides in a murine model of acute respiratory distress syndrome. Sci Rep 2021; 11:7777. [PMID: 33833346 PMCID: PMC8032690 DOI: 10.1038/s41598-021-87462-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 03/22/2021] [Indexed: 12/11/2022] Open
Abstract
Due to frequent and often severe lung affections caused by COVID-19, murine models of acute respiratory distress syndrome (ARDS) are increasingly used in experimental lung research. The one induced by a single lipopolysaccharide (LPS) exposure is practical. However, whether it is preferable to administer LPS intranasally or intratracheally remains an open question. Herein, female C57Bl/6 J mice were exposed intranasally or intratracheally to one dose of either saline or 3 mg/kg of LPS. They were studied 24 h later. The groups treated with LPS, either intranasally or intratracheally, exhibited a pronounced neutrophilic inflammation, signs of lung tissue damage and protein extravasation into the alveoli, and mild lung dysfunction. The magnitude of the response was generally not different between groups exposed intranasally versus intratracheally. However, the variability of some the responses was smaller in the LPS-treated groups exposed intranasally versus intratracheally. Notably, the saline-treated mice exposed intratracheally demonstrated a mild neutrophilic inflammation and alterations of the airway epithelium. We conclude that an intranasal exposure is as effective as an intratracheal exposure in a murine model of ARDS induced by LPS. Additionally, the groups exposed intranasally demonstrated less variability in the responses to LPS and less complications associated with the sham procedure.
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Affiliation(s)
- Fatemeh Khadangi
- Institut Universitaire de Cardiologie et de Pneumologie de Québec - Université Laval, Pavillon Mallet, M2694, 2725, chemin Sainte-Foy, Quebec, QC, G1V 4G5, Canada
| | - Anne-Sophie Forgues
- Institut Universitaire de Cardiologie et de Pneumologie de Québec - Université Laval, Pavillon Mallet, M2694, 2725, chemin Sainte-Foy, Quebec, QC, G1V 4G5, Canada
| | - Sophie Tremblay-Pitre
- Institut Universitaire de Cardiologie et de Pneumologie de Québec - Université Laval, Pavillon Mallet, M2694, 2725, chemin Sainte-Foy, Quebec, QC, G1V 4G5, Canada
| | - Alexis Dufour-Mailhot
- Institut Universitaire de Cardiologie et de Pneumologie de Québec - Université Laval, Pavillon Mallet, M2694, 2725, chemin Sainte-Foy, Quebec, QC, G1V 4G5, Canada
| | - Cyndi Henry
- Institut Universitaire de Cardiologie et de Pneumologie de Québec - Université Laval, Pavillon Mallet, M2694, 2725, chemin Sainte-Foy, Quebec, QC, G1V 4G5, Canada
| | - Magali Boucher
- Institut Universitaire de Cardiologie et de Pneumologie de Québec - Université Laval, Pavillon Mallet, M2694, 2725, chemin Sainte-Foy, Quebec, QC, G1V 4G5, Canada
| | - Marie-Josée Beaulieu
- Institut Universitaire de Cardiologie et de Pneumologie de Québec - Université Laval, Pavillon Mallet, M2694, 2725, chemin Sainte-Foy, Quebec, QC, G1V 4G5, Canada
| | - Mathieu Morissette
- Institut Universitaire de Cardiologie et de Pneumologie de Québec - Université Laval, Pavillon Mallet, M2694, 2725, chemin Sainte-Foy, Quebec, QC, G1V 4G5, Canada
| | | | - David Brunet
- SCIREQ - Scientific Respiratory Equipment Inc., Montreal, Canada
| | | | - Ynuk Bossé
- Institut Universitaire de Cardiologie et de Pneumologie de Québec - Université Laval, Pavillon Mallet, M2694, 2725, chemin Sainte-Foy, Quebec, QC, G1V 4G5, Canada.
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Khadangi F, Torkamanzehi A, Kerachian MA. Identification of missense and synonymous variants in Iranian patients suffering from autosomal dominant polycystic kidney disease. BMC Nephrol 2020; 21:408. [PMID: 32957937 PMCID: PMC7507688 DOI: 10.1186/s12882-020-02069-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 09/15/2020] [Indexed: 11/10/2022] Open
Abstract
Background Autosomal dominant polycystic kidney disease (ADPKD), the predominant type of inherited kidney disorder, occurs due to PKD1 and PKD2 gene mutations. ADPKD diagnosis is made primarily by kidney imaging. However, molecular genetic analysis is required to confirm the diagnosis. It is critical to perform a molecular genetic analysis when the imaging diagnosis is uncertain, particularly in simplex cases (i.e. a single occurrence in a family), in people with remarkably mild symptoms, or in individuals with atypical presentations. The main aim of this study is to determine the frequency of PKD1 gene mutations in Iranian patients with ADPKD diagnosis. Methods Genomic DNA was extracted from blood samples from 22 ADPKD patients, who were referred to the Qaem Hospital in Mashhad, Iran. By using appropriate primers, 16 end exons of PKD1 gene that are regional hotspots, were replicated with PCR. Then, PCR products were subjected to DNA directional Sanger sequencing. Results The DNA sequencing in the patients has shown that exons 35, 36 and 37 were non- polymorphic, and that most mutations had occurred in exons 44 and 45. In two patients, an exon-intron boundary mutation had occurred in intron 44. Most of the variants were missense and synonymous types. Conclusion In the present study, we have shown the occurrence of nine novel missense or synonymous variants in PKD1 gene. These data could contribute to an improved diagnostic and genetic counseling in clinical settings.
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Affiliation(s)
- Fatemeh Khadangi
- Department of Biology, University of Sistan and Baluchestan, Zahedan, Iran.,Medical Genetics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Adam Torkamanzehi
- Department of Biology, University of Sistan and Baluchestan, Zahedan, Iran
| | - Mohammad Amin Kerachian
- Medical Genetics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran. .,Department of Medical Genetics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
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Gazzola M, Khadangi F, Clisson M, Beaudoin J, Clavel MA, Bossé Y. Airway smooth muscle adapting in dynamic conditions is refractory to the bronchodilator effect of a deep inspiration. Am J Physiol Lung Cell Mol Physiol 2020; 318:L452-L458. [PMID: 31913645 DOI: 10.1152/ajplung.00270.2019] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Airway smooth muscle (ASM) is continuously strained during breathing at tidal volume. Whether this tidal strain influences the magnitude of the bronchodilator response to a deep inspiration (DI) is not clearly defined. The present in vitro study examines the effect of tidal strain on the bronchodilator effect of DIs. ASM strips from sheep tracheas were mounted in organ baths and then subjected to stretches (30% strain), simulating DIs at varying time intervals. In between simulated DIs, the strips were either held at a fixed length (isometric) or oscillated continuously by 6% (length oscillations) to simulate tidal strain. The contractile state of the strips was also controlled by adding either methacholine or isoproterenol to activate or relax ASM, respectively. Although the time-dependent gain in force caused by methacholine was attenuated by length oscillations, part of the acquired force in the oscillating condition was preserved postsimulated DIs, which was not the case in the isometric condition. Consequently, the bronchodilator effect of simulated DIs (i.e., the decline in force postsimulated versus presimulated DIs) was attenuated in oscillating versus isometric conditions. These findings suggest that an ASM operating in a dynamic environment acquired adaptations that make it refractory to the decline in contractility inflicted by a larger strain simulating a DI.
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Affiliation(s)
- Morgan Gazzola
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Laval University, Quebec City, Quebec, Canada
| | - Fatemeh Khadangi
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Laval University, Quebec City, Quebec, Canada
| | - Marine Clisson
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Laval University, Quebec City, Quebec, Canada
| | - Jonathan Beaudoin
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Laval University, Quebec City, Quebec, Canada
| | - Marie-Annick Clavel
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Laval University, Quebec City, Quebec, Canada
| | - Ynuk Bossé
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Laval University, Quebec City, Quebec, Canada
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Gazzola M, Henry C, Lortie K, Khadangi F, Park CY, Fredberg JJ, Bossé Y. Airway smooth muscle tone increases actin filamentogenesis and contractile capacity. Am J Physiol Lung Cell Mol Physiol 2020; 318:L442-L451. [PMID: 31850799 DOI: 10.1152/ajplung.00205.2019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Force adaptation of airway smooth muscle (ASM) is a process whereby the presence of tone (i.e., a sustained contraction) increases the contractile capacity. For example, tone has been shown to increase airway responsiveness in both healthy mice and humans. The goal of the present study is to elucidate the underlying molecular mechanisms. The maximal force generated by mouse tracheas was measured in response to 10-4 M of methacholine following a 30-min period with or without tone elicited by the EC30 of methacholine. To confirm the occurrence of force adaptation at the cellular level, traction force generated by cultured human ASM cells was also measured following a similar protocol. Different pharmacological inhibitors were used to investigate the role of Rho-associated coiled-coil containing protein kinase (ROCK), protein kinase C (PKC), myosin light chain kinase (MLCK), and actin polymerization in force adaptation. The phosphorylation level of the regulatory light chain (RLC) of myosin, the amount of actin filaments, and the activation level of the actin-severing protein cofilin were also quantified. Although ROCK, PKC, MLCK, and RLC phosphorylation was not implicated, force adaptation was prevented by inhibiting actin polymerization. Interestingly, the presence of tone blocked the activation of cofilin in addition to increasing the amount of actin filaments to a maximal level. We conclude that actin filamentogenesis induced by tone, resulting from both actin polymerization and the prevention of cofilin-mediated actin cleavage, is the main molecular mechanism underlying force adaptation.
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Affiliation(s)
- Morgan Gazzola
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Quebec City, Quebec, Canada
| | - Cyndi Henry
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Quebec City, Quebec, Canada
| | - Katherine Lortie
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Quebec City, Quebec, Canada
| | - Fatemeh Khadangi
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Quebec City, Quebec, Canada
| | - Chan Young Park
- Harvard School of Public Health, Harvard University, Boston, Massachusetts
| | - Jeffrey J Fredberg
- Harvard School of Public Health, Harvard University, Boston, Massachusetts
| | - Ynuk Bossé
- Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Quebec City, Quebec, Canada
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Gazzola M, Khadangi F, Clisson M, Beaudoin J, Clavel MA, Bossé Y. Shortening of airway smooth muscle is modulated by prolonging the time without simulated deep inspirations in ovine tracheal strips. J Appl Physiol (1985) 2019; 127:1528-1538. [PMID: 31545157 DOI: 10.1152/japplphysiol.00423.2019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The shortening of airway smooth muscle (ASM) is greatly affected by time. This is because stimuli affecting ASM shortening, such as bronchoactive molecules or the strain inflicted by breathing maneuvers, not only alter quick biochemical processes regulating contraction but also slower processes that allow ASM to adapt to an ever-changing length. Little attention has been given to the effect of time on ASM shortening. The present study investigates the effect of changing the time interval between simulated deep inspirations (DIs) on ASM shortening and its responsiveness to simulated DIs. Excised tracheal strips from sheep were mounted in organ baths and either activated with methacholine or relaxed with isoproterenol. They were then subjected to simulated DIs by imposing swings in distending stress, emulating a transmural pressure from 5 to 30 cmH2O. The simulated DIs were intercalated by 2, 5, 10, or 30 min. In between simulated DIs, the distending stress was either fixed or oscillating to simulate tidal breathing. The results show that although shortening was increased by prolonging the interval between simulated DIs, the bronchodilator effect of simulated DIs (i.e., the elongation of the strip post- vs. pre-DI) was not affected, and the rate of re-shortening post-simulated DIs was decreased. As the frequency with which DIs are taken increases upon bronchoconstriction, our results may be relevant to typical alterations observed in asthma, such as an increased rate of re-narrowing post-DI.NEW & NOTEWORTHY The frequency with which patients with asthma take deep inspirations (DIs) increases during bronchoconstriction. This in vitro study investigated the effect of changing the time interval between simulated DIs on airway smooth muscle shortening. The results demonstrated that decreasing the interval between simulated DIs not only decreases shortening, which may be protective against excessive airway narrowing, but also increases the rate of re-shortening post-simulated DIs, which may contribute to the increased rate of re-narrowing post-DI observed in asthma.
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Khadangi F, Bossé Y. Extracellular regulation of airway smooth muscle contraction. Int J Biochem Cell Biol 2019; 112:1-7. [PMID: 31042549 DOI: 10.1016/j.biocel.2019.04.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 04/25/2019] [Accepted: 04/26/2019] [Indexed: 01/22/2023]
Abstract
The molecular mechanisms governing the contraction of airway smooth muscle have always been at the forefront of asthma research. New extracellular molecules affecting the contraction of airway smooth muscle are steadily being discovered. Although interesting, this is disconcerting for researchers trying to find a mend for the significant part of asthma symptoms caused by contraction. Additional efforts are being deployed to understand the intracellular signaling pathways leading to contraction. The goal being to find common pathways that are essential to convey the contractile signal emanating from any single or combination of extracellular molecules. Not only these pathways exist and their details are being slowly unveiled, but some carry the signal inside-out to interact back with extracellular molecules. These latter represent targets with promising therapeutic potential, not only because they are molecules downstream of pathways essential for contraction but also because their extracellular location makes them readily accessible by inhaled drugs.
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Abstract
α-Tocopherol is the only tocopherol that has been shown to prevent the human deficiency disease Ataxia with Isolated Vitamin E Deficiency (AVED), and thus it is the only one that, for humans, can be called vitamin E. Vitamin E in addition to preventing AVED has documented immune boosting properties and an activity against nonalcoholic hepatosteatosis and low-grade inflammation. Epidemiological studies indicating that vitamin E could prevent cardiovascular events, neurodegenerative disease, macular degeneration, and cancer were in general not confirmed by clinical intervention studies. Vitamin E and some of its metabolites modulate cell signaling and gene transcription. Future research is needed to achieve a better understanding of the molecular events leading to gene regulation by vitamin E, especially in its phosphorylated form. Isolation and characterization of the vitamin E kinase and vitamin E phosphate phosphatase will help in the understanding of cell regulation processes modulated by vitamin E. A clarification of the pathogenesis of AVED remains an important goal to be achieved. © 2018 IUBMB Life, 71(4):411-415, 2019.
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Affiliation(s)
| | - Angelo Azzi
- Vascular Biology Laboratory, JM USDA-HNRCA at Tufts University, Boston, Massachusetts
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Hamzehzadeh L, Khadangi F, Ghayoor Karimiani E, Pasdar A, Kerachian MA. Common KRAS and NRAS gene mutations in sporadic colorectal cancer in Northeastern Iranian patients. Curr Probl Cancer 2018; 42:572-581. [PMID: 29921458 DOI: 10.1016/j.currproblcancer.2018.05.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 04/26/2018] [Accepted: 05/17/2018] [Indexed: 02/06/2023]
Abstract
OBJECTIVES Mutation analysis of the Epidermal Growth Factor Receptor downstream has been a main part of colorectal carcinoma evaluation. Large prospective clinical trials have shown only colorectal cancer (CRC) with wild-type KRAS and NRAS responds to anti-Epidermal Growth Factor Receptor treatment. Hence, mutation analysis is necessary prior to treatment. It is essential to conduct studies to learn about the mutation signature of such tumors. The aim of this study was to evaluate the frequency of hotspot mutations in KRAS and NRAS genes in Iranian CRC patients and to explore their correlations with clinicopathologic parameters. METHODS We detected mutations in exon 2 (codons 12 and 13) of the KRAS and NRAS genes using high resolution melting analysis, Intplex design and Sanger sequencing in 87 Iranian CRC patients. Genomic DNA was isolated from fresh tissue samples of CRC patients. RESULTS From 87 eligible cases, 51 were male and 36 were females. KRAS mutations in codons 12 and 13 were present in 28.7% of all analyzed CRCs. Our findings suggested that the tumors with KRAS mutations are not with well- and moderately differentiated tumors compared to poorly differentiated tumors (P value = 0.32). The most frequent types of mutations were glycine to aspartate on codon 12 (p.G12D), and glycine to aspartate on codon 13 (p.G13D). No mutation was found in the NRAS gene in our patients. CONCLUSIONS Based on this study, the frequency of KRAS mutations seems to be in the spectrum of frequencies of other countries such as China, Japan, India, USA, France, and Germany and NRAS was similar to the West of Iran.
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Affiliation(s)
- Leila Hamzehzadeh
- Department of Medical Genetics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Fatemeh Khadangi
- Cancer Genetics Research Unit, Reza Radiotherapy and Oncology Center, Mashhad, Iran
| | - Ehsan Ghayoor Karimiani
- Razavi Cancer Research Center, Razavi Hospital, Imam Reza International University, Mashhad, Iran; Division of Evolution and Genomic Sciences, Faculty of Biology, Medicine and Health Sciences, University of Manchester, UK
| | - Alireza Pasdar
- Department of Medical Genetics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran; Division of Applied Medicine, Medical School, University of Aberdeen, Foresterhill, Aberdeen, UK.
| | - Mohammad Amin Kerachian
- Department of Medical Genetics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran; Cancer Genetics Research Unit, Reza Radiotherapy and Oncology Center, Mashhad, Iran; Medical Genetics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
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Abstract
BACKGROUND Although different methods have been established to detect Helicobacter pylori (H. pylori) infection, identifying infected patients is an ongoing challenge. The aim of this meta-analysis was to provide pooled diagnostic accuracy measures for stool PCR test in the diagnosis of H. pylori infection. METHODS In this study, a systematic review and meta-analysis were carried out on various sources, including MEDLINE, Web of Sciences, and the Cochrane Library from April 1, 1999, to May 1, 2016. This meta-analysis adheres to the guidelines provided by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses report (PRISMA Statement). The clinical value of DNA stool PCR test was based on the pooled false positive, false negative, true positive, and true negative of different genes. RESULTS Twenty-six of 328 studies identified met the eligibility criteria. Stool PCR test had a performance of 71% (95% CI: 68-73) sensitivity, 96% (95% CI: 94-97) specificity, and 65.6 (95% CI: 30.2-142.5) diagnostic odds ratio (DOR) in diagnosis of H. pylori. The DOR of genes which showed the highest performance of stool PCR tests was as follows: 23S rRNA 152.5 (95% CI: 55.5-418.9), 16S rRNA 67.9 (95%CI: 6.4-714.3), and glmM 68.1 (95%CI: 20.1-231.7). CONCLUSIONS The sensitivity and specificity of stool PCR test are relatively in the same spectrum of other diagnostic methods for the detection of H. pylori infection. In descending order of significance, the most diagnostic candidate genes using PCR detection were 23S rRNA, 16S rRNA, and glmM. PCR for 23S rRNA gene which has the highest performance could be applicable to detect H. pylori infection.
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Affiliation(s)
- Fatemeh Khadangi
- Cancer Genetics Research Unit, Reza Radiotherapy and Oncology Center, Mashhad, Iran
| | - Maryam Yassi
- Cancer Genetics Research Unit, Reza Radiotherapy and Oncology Center, Mashhad, Iran
| | - Mohammad Amin Kerachian
- Cancer Genetics Research Unit, Reza Radiotherapy and Oncology Center, Mashhad, Iran.,Cancer Genetics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.,Department of Medical Genetics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
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