Peribronchial Cells Research Articles

Further explorations into the role of mast cells in deaths associated with fatal asphyxia: an immunohistochemical study utilizing CD 117 marker

Asphyxia-related deaths have always been a challenging task in the speciality of forensic pathology. Apart from helpful macroscopical signs (e.g., strangulation mark, cyanosis, petechial haemorrhage, and lung oedema), recent literature indicates that prolonged asphyxia is sufficient to induce an increase in mast cells (MC). Inflammatory cells migrate from the bone marrow to the lungs, aiding in the diagnosis of fatal asphyxial deaths. HIF1-α, a key regulator protein, is released from lung tissue capillaries during catastrophic hypoxia circumstances, as previously demonstrated in immunohistochemistry (IHC) research. The present study analyzed lung samples from 164 medico-legal autopsy cases, including 57 asphyxia/hypoxia deaths and 107 controls (non-asphyxial deaths). Peribronchial, perivascular and perialveolar MCs were detected using CD117 antibody, and the average of MCs in each of these locations was noted in each case. The results indicated a statistically significant increase in peribronchial and perialveolar mast cells (MC) in fatal asphyxial deaths, including those caused by hanging, drowning, or postural asphyxia. Peri-bronchial MC in lung sections of asphyxial deaths were in the range of 0.2–5.4 and in non-asphyxial samples were in the range of 0.0–2.2. Peri-alveolar MCs in lung sections of asphyxial deaths were in the range of 0.0–0.6 and in non-asphyxial samples were in the range of 0.0–0.2. Our data suggest that mast cells (MC) play an important role in fatal hypoxia-related mortality and CD 117 may be a reliable marker for detection of mast cells in asphyxial deaths. It could be very beneficial to forensic pathologists tasked with differentiating fatal asphyxia fatalities from other causes of death.

Niche-mediated repair of airways is directed in an occupant-dependent manner.

In injured airways of the adult lung, epithelial progenitors are called upon to repair by nearby mesenchymal cells via signals transmitted through the niche. Currently, it is unclear whether repair is coordinated by the mesenchymal cells that maintain the niche or by the airway epithelial cells that occupy it. Here, we show that the spatiotemporal expression of Fgf10 by the niche is primarily orchestrated by the niche's epithelial occupants-both those that reside prior to, and following, injury. During homeostasis, differentiated airway epithelial cells secrete Sonic hedgehog (Shh) to inhibit Fgf10 expression by Gli1+ peribronchial mesenchymal cells in the niche. After injury, remaining epithelial cells produce Wnt7b to induce Fgf10 expression in airway smooth muscle cells in the niche. We find that this reliance on a common activator of airway epithelial stem cells also allows for the recruitment of remote stem cell populations when local populations have been exhausted.

Evaluation of correlation of EIV(H3N8) replication and pathological changes in lungs of BALB/c mice

Equine influenza (EI) is a highly contagious viral respiratory disease caused by the equine influenza virus (EIV). Frequent antigenic changes of EIV warrants thorough pathological evaluation and in-vivo replication of the circulating viruses in an experimental animal model for selection of vaccine strain. In the present study, EIV (H3N8) was inoculated into BALB/c mice and subsequently, gross, histopathological and immunohistochemical examination of the lungs was performed to evaluate the correlation of virus replication with corresponding pathological changes. Microscopically, at 1dpi, lungs from mice infected with EIV revealed degeneration of epithelial tissues, whereas indirect immunoperoxidase staining (IIPT) results showed high EIV antigen positivity in the bronchial and bronchiolar epithelium and mild positivity in the infiltrating cells. Subsequently from 1 dpi to 3 dpi, the virus replicated and infected other parenchymal cells, which led to recruitment of inflammatory cells. Microscopically moderate peribronchial, peribronchiolar and perivascular cuffing of neutrophils and macrophages were observed, whereas IIPT exhibited, scanty and moderate EIV antigen positive interstitial infiltrating macrophages. At 5 and 7 dpi, severe, diffuse interstitial thickening, bronchial, bronchiolar and alveolar epithelial necrosis and denudation, perivascular and peribronchial mononuclear cells cuffing were observed, which could be correlated with IIPT as high EIV antigen positivity of infiltrating macrophages and type II pneumocytes. However, from 11 dpi onwards, microscopically, moderate interstitium thickening and perivascular and peribronchial cuffing were observed whereas, tissues were negative for EIV antigen in IIPT. Mild, focal inflammation could be observed at 14 dpi. Present findings signify the correlation of virus replication with corresponding histopathological changes, which will be useful for assessing the efficacy of anti-influenza drug molecules and EIV vaccines.

HIGH GRADE SARCOMA WITH MYXOID FEATURES

SESSION TITLE: Medical Student/Resident Lung Cancer Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Primary pulmonary sarcomas (PPS) are a rare tumor entity in general and tend to be low grade tumors (1). Most sarcomas diagnosed in the lung are due to metastasis and follow an aggressive course (2,3,4,5). This case presents an aggressive, high grade, primary lung spindle cell sarcoma with myxoid features. CASE PRESENTATION: An 84-year-old female presented with chest pain and worsening dyspnea on exertion for two weeks. Imaging revealed a left posterior perihilar mass in her lung. The patient was stabilized and discharged with planned outpatient bronchoscopy with endobronchial ultrasound with transbronchial needle biopsy (EBUS-TBNA). Biopsies of left hilar adenopathy and the lower lobe mass were positive for malignant cells. Histologic analysis, including immunohistochemistry, revealed the tumor to be most consistent with Primary Spindle Cell Sarcoma of the lung not otherwise specified (NOS). The patient presented two weeks after the bronchoscopy with worsening dyspnea and cough. Repeat imaging of her chest revealed significant progression of the mass-like consolidation. The patient was admitted for further evaluation. She became hemodynamically unstable and required intubation with mechanical ventilation and vasopressor support. The patient’s malignancy was determined staged as IVA, M1a. The patient's clinical status continued to rapidly deteriorate. The patient and her family decided to pursue comfort cares and the patient died shortly thereafter. DISCUSSION: Primary Pulmonary Myxoid Sarcoma (PPMS) is a similar tumor entity to PPS. Histologically, PPMS is characterized by polygonal tumor or spindle cells in a myxoid stroma with some atypia (4,6). The time of symptom onset to expiration was 61 days. This case describes a tumor with both aggressive and non-aggressive characteristics. Tissue analysis of this tumor revealed no cytological atypia or necrosis. Feng et al found that tumors in the respiratory system have a poorer prognosis. Tumor size is a prognostic indicator in PPS and tumors over 5 cm had a poorer overall survival (8). This tumor at symptom onset was 8 cm. The size and location of this tumor may have contributed to its aggressiveness and prognosis. Surgical resection is the treatment of choice for PPS and PPMS (3,7,8,9). CONCLUSIONS: There have been few case reports of this type of tumor being an aggressive and high-grade tumor. Given the aggressive nature, physicians need to be aware of this entity so appropriate guidance to patients and families can be provided. Furthermore, more research needs to be done in order to better classify this type of primary sarcoma of the lung. Reference #1: 1.Prieto-Granada CN, Ganim RB, Zhang L, Antonescu C, Mueller J. Primary Pulmonary Myxoid Sarcoma: A Newly Described Entity—Report of a Case and Review of the Literature. International Journal of Surgical Pathology. 2017;25(6):518-525. doi:10.1177/1066896917706413. Reference #2: 2.Koelsche C, Tavernar L, Neumann O, et al. Primary pulmonary myxoid sarcoma with an unusual gene fusion between exon 7 of EWSR1 and exon 5 of CREB1. Virchows Archiv. 2019. doi:10.1007/s00428-019-02716-4. Reference #3: 3.Billingsley KG, Burt ME, Jara E, et al. Pulmonary Metastases From Soft Tissue Sarcoma. Annals of Surgery. 1999;229(5):602. doi:10.1097/00000658-199905000-00002. 4.Jeon YK, Moon KC, Park S-H, Chung DH. Primary pulmonary myxoid sarcomas with EWSR1-CREB1 translocation might originate from primitive peribronchial mesenchymal cells undergoing (myo)fibroblastic differentiation. Virchows Archiv. 2014;465(4):453-461. doi:10.1007/s00428-014-1645-z. 5.Von Mehren M, Randall L, Benjamin RS et al. Soft tissue sarcoma version 2.2018. The Journal of the National Comprehensive Cancer Network. 2018;16(5): 536-563. doi: 10.6004/jnccn.2018.0025 6.Thway K, Nicholson AG, Lawson K, et al. Primary Pulmonary Myxoid Sarcoma With EWSR1-CREB1 Fusion. The American Journal of Surgical Pathology. 2011;35(11):1722-1732. doi:10.1097/pas.0b013e318227e4d2. 7.Feng L, Wang M, Yibulayin F, et al. Spindle cell sarcoma: a SEER population-based analysis. Scientific Reports. 2018;8(1). doi:10.1038/s41598-018-23145-4. 8.Spraker MB, Bair E, Bair R, Connell PP, Mahmood U, Koshy M. An Analysis of Patient Characteristics and Clinical Outcomes in Primary Pulmonary Sarcoma. Journal of Thoracic Oncology. 2013;8(2):147-151. doi:10.1097/jto.0b013e318277401f. 9.Bacha EA, Wright CD, Grillo HC, et al. Surgical treatment of primary pulmonary sarcomas1. European Journal of Cardio-Thoracic Surgery. 1999;15(4):456-460. doi:10.1016/s1010-7940(99)00045-7. DISCLOSURES: No relevant relationships by Jared Alberts, source=Web Response No relevant relationships by Alheli Arce Gastelum, source=Web Response No relevant relationships by Zachary DePew, source=Web Response No relevant relationships by Paul Millner, source=Web Response No relevant relationships by Kenneth Mueller, source=Web Response

Pulmonary Langerhans Cell Histiocytosis Presenting With Unusual Radiologic Features

SESSION TITLE: Sarcoidosis and Cystic Lung Disease SESSION TYPE: Affiliate Case Report Poster PRESENTED ON: Tuesday, October 31, 2017 at 01:30 PM - 02:30 PM INTRODUCTION: Pulmonary Langerhans Cell Histiocytosis (PLCH) is a rare interstitial lung disease with characteristic features on computed tomography (CT) of nodular and cystic lesions in an upper to middle lung distribution. We present a case of PLCH with diffuse centrilobular ground glass nodularity and hemoptysis. CASE PRESENTATION: A 51 year-old Ukrainian female with a 10 pack-year smoking history presented with intermittent submassive hemoptysis over 6 months. Extensive environmental and occupational exposure history was unremarkable. Physical examination was notable for bibasilar crackles on auscultation. Vital signs showed normal saturation on room air. Laboratory data revealed Hemoglobin of 12 (Normal: 12-16), elevated c-reactive protein of 6.2 (Normal: 0-0.8), and positive Quantiferon Gold. Sputum returned with negative acid-fast bacilli smears, gram stains, and cultures. CT scan of the thorax revealed diffuse bilateral centrilobular ground glass nodularity without focal consolidation or mediastinal lymphadenopathy. Work-up for hypersensitivity pneumonitis and connective tissue diseases was negative. Video bronchoscopy with bronchoalveolar lavage yielded a predominance of alveolar macrophages (95%) with negative microbiology and cytology. Transbronchial biopsy revealed hemosiderin deposits and nonspecific inflammation. Unfortunately, she signed out against medical advice. One month later, she presented with worsening hemoptysis and repeat CT of the thorax demonstrated progression of diffuse bilateral centrilobular nodularity (fig. 1). Surgical lung biopsy was performed which revealed obliterative bronchiolitis with intraluminal blood, hemosiderin deposition, adjacent cyst formation, and nodules in various states of fibrosis and inflammation. Pathognomonic CD1-antigen stain was positive for peribronchial and intrabronchial Langerhans cells consistent with PLCH (fig. 2). Our patient’s hemoptysis and CT findings resolved with abstinence of smoking. DISCUSSION: Diffuse centrilobular nodules, as seen in our patient, have not yet been described in PLCH to the best of our knowledge. This radiologic pattern represents early changes with significant inflammatory infiltration as evidenced by biopsy. With advances in radiologic techniques and enhanced resolution new patterns may be identified. CONCLUSIONS: Further studies are needed to identify the spectrum of radiographic presentations, especially to determine if diffuse centrilobular nodular opacities represent earlier changes seen in PLCH. This will provide opportunities for early diagnosis with timely treatment and has potential prognostic implications. Reference #1: Juvet SC, Hwang D, Downey GP. Rare lung diseases III: Pulmonary Langerhans' cell histiocytosis. Candian Respiratory Journal: Journal of the Canadian Thoracic Society. 2010; 17(3):e55-62. DISCLOSURE: The following authors have nothing to disclose: Spencer Pugh, Anil Singh, Tina Dudney, Arseniy Tsapenko No Product/Research Disclosure Information

Histopathological yield in different types of bronchoscopic biopsies in proven cases of pulmonary tuberculosis.

Diagnosis of pulmonary tuberculosis (TB) is difficult and often requires a lung biopsy. The goal of this retrospective study was to determine the histopathological parameters useful for diagnosis of pulmonary TB in different types of bronchoscopic biopsies (transbronchial lung biopsy [TBLB], transbronchial needle aspiration [TBNA], and bronchial biopsy [BB]). The records of patients diagnosed to have pulmonary TB, over a period of 1-year were evaluated. Patients with positive acid-fast bacilli (AFB) culture and with three bronchoscopic biopsies including TBLB, TBNA, and BB were included in the study. Selected (14) histological parameters were evaluated retrospectively in a total of 27 biopsies from 9 patients with TB after hematoxylin-eosin and Ziehl-Neelsen staining. Diagnostic yield in TBLBs and TBNA was similar for granulomas detection (66.6% each). Granulomas in TBNA were larger, caseating and confluent as compared to small interstitial granulomas seen in TBLB. AFB was demonstrated in only one patient in TBNA. Lymphocytic cell cuffing was seen around most TBLB granulomas. One patient also showed microfilaria in blood vessel in TBLB. BBs in all patients showed the presence of goblet cell metaplasia and increased peribronchial plasma cell infiltrate with or without eosinophils may be indicative of chronic injury. The yield of granulomas was low in BBs seen in only 2 patients (22.2%). Diagnostic yield of TBNA and TBLB for granulomas was similar; however, caseation was seen more frequently in TBNA than on TBLB. Of other histological parameters, bronchial metaplastic changes and peribronchial plasma cells infiltrate were constant findings in all tubercular biopsies indicative of chronic injury.

Primary pulmonary myxoid sarcomas with EWSR1-CREB1 translocation might originate from primitive peribronchial mesenchymal cells undergoing (myo)fibroblastic differentiation.

Primary pulmonary myxoid sarcoma (PPMS) is a very rare lung tumor that has recently been shown to harbor an EWSR1-CREB1 translocation. However, the histogenesis and biological behavior of PPMS remains unclear. To provide insight into the histogenesis of PPMS, we studied surgical resection specimens of four patients, two females and two males with an age range of 26 to 65 years, all non-smokers with mild anemia. The tumors, three of which are endobronchial, measured between 4 and 13 cm. One patient developed metastasis to the contra-lateral lung 7 months after resection. Other patients remained alive without tumor for 1.5, 10, and 13 years. Fluorescence in situ hybridization (FISH) analysis with a gene break apart probe showed an EWSR1 translocation in all cases. The EWSR1-CREB1 fusion transcript was detected in all cases by reverse-transcription PCR. Immunohistochemical staining showed diffuse positive staining of the tumor cells only for vimentin. Tumor cells expressed no other myoid, epithelial, endothelial, melanocytic, myoepithelial, or neuroendocrine markers, except for smooth muscle actin and epithelial membrane antigen, which were only focally positive in individual cases. Ultrastructural analyses revealed the presence in the tumor cells of intermediate filaments with focal densities along the sub-cytoplasmic membrane as well as dense plaques. These results suggest that PPMS exhibits myofibroblastic differentiation. We conclude that PPMS is an intermediate grade malignant lung tumor harboring EWSR1 translocations, which may originate from mesenchymal cells that undergo fibroblastic or myofibroblastic differentiation.

Experimental Respiratory Syncytial Virus Infection of Human Peribronchial Gland Cells In Vitro

Respiratory syncytial virus (RSV) is a relevant agent of respiratory tract infections, especially in exacerbations of chronic lung diseases. Peribronchial submucosal glands are the main source of tracheobronchial mucus and therefore of major interest. The authors isolated and cultured human peribronchial gland cells and infected them with RSV. The course of infection was monitored by transmission electron, immuno-, and lectin fluorescence microscopy. Morphology shows virus factories with budding particles within cytoplasmatic vacuoles and virus release after 44 h of infection. Experimental infection of human peribronchial gland cells in primary culture appears to be a suitable model in pulmonary research.

Inhibition of allergen-induced airway remodeling by neonatal bacillus Calmette-Guerin vaccination is associated with interferon-gamma–producing T cells but not regulatory T cells in mice

Epidemiological assessments of patients and studies using animal models show that exposure to Mycobacterium bovis bacillus Calmette-Guerin (BCG) vaccine in early life prevents asthma development. However, little is known about the potential of neonatal BCG vaccination in preventing the development of airway remodeling of asthma. To investigate the effects of multiple BCG vaccinations of neonates on the airway remodeling in mice and the accompanied pulmonary T cell responses. BALB/c neonates were vaccinated with BCG 3 times. At 5 and 7 weeks of age, the mice were sensitized and then challenged with aerosolized ovalbumin (OVA) 3 times per week for 8 successive weeks. The extent of airway remodeling and induced pulmonary T cell responses were characterized. Multiple BCG vaccinations of neonates reduced OVA-induced remodeling events, including levels of peribronchial α-smooth muscle actin, peribronchial fibrosis, and airway epithelial mucin accumulation. The BCG vaccinations also decreased peribronchial cells expression of transforming growth factor beta 1 (TGF-β1). In contrast, BCG vaccinations increased the frequency of interferon-gamma (IFN-γ)-producing T cells in the lung and IFN-γ level in BALF, with no effects on pulmonary regulatory T cells and IL-17-producing T cells. Our data suggest that multiple BCG vaccinations of neonates reduced metrics characteristic of allergen-induced airway remodeling. More importantly, this decrease was not associated with an increased number of pulmonary regulatory T cells but instead correlated with an increase of IFN-γ-producing T cells.

Role of aquaporin 5 in antigen‐induced airway inflammation and mucous hyperproduction in mice

Airway inflammation and mucus hyperproduction play the central role in the development of asthma, although the mechanisms remain unclear. The aquaporin (AQP)-5 may be involved in the process due to its contribution to the volume of liquid secreted from the airways. The present study firstly found the overexpression of AQP5 in the airway epithelium and submucosal glands of asthmatics. Furthermore, we aimed at evaluating the role of AQP5 in airway inflammation and mucous hyperproductions during chronic allergic responses to house dust mite (HDM). Bronchoalveolar lavage levels of interleukin (IL)-2, IL-4, IL-10, interferon-γ and Mucin 5AC (MUC5AC), and number of peribronchial and perivascular cells were measured in AQP5 wild-type and AQP5 knockout (KO) mice. We found that HDM induced airway inflammation, lung Th2 cell accumulation and mucin hypersecretion in C57BL/6 mice rather than AQP5 KO mice. Expression of MUC5AC and MUC5B proteins and genes in the lung tissue was significantly lower in AQP5 KO mice. Thus, our results implicate involvement of AQP5 in the development of airway inflammation and mucous hyperproduction during chronic asthma.

Chronic OVA allergen challenged TNF p55/p75 receptor deficient mice have reduced airway remodeling

The role of tumor necrosis factor-α (TNF-α) in contributing to allergen induced airway remodeling in asthma is unknown. In this study we have utilized a mouse model of chronic OVA allergen induced airway remodeling to determine whether TNF p55/p75 receptor deficient mice (abbreviated TNF-R KO) had reduced levels of airway remodeling. Chronic OVA challenged WT mice had significantly increased levels of lung eosinophilic inflammation as well as features of airway remodeling including increased peribronchial fibrosis, thickness of the peribronchial smooth muscle layer, mucus expression, and deposition of extracellular matrix proteins. In contrast, TNF-R KO mice had significantly reduced levels of major basic protein positive peribronchial eosinophils and significantly reduced peribronchial fibrosis assessed by quantitating the area of peribronchial trichrome staining and total lung collagen. In addition, TNF-R KO mice had significantly reduced thickness of the peribronchial smooth muscle layer, area of peribronchial α-smooth muscle actin immunostaining, and levels of the extracellular matrix protein fibronectin. There was a non-significant trend for reduced mucus expression in TNF-R KO mice. Levels of peribronchial cells immunostaining positive for TGF-β1 were significantly reduced in TNF-R KO mice suggesting that reduced levels of TGF-β1 expression in TNF-R KO mice may contribute to reduced airway remodeling. Overall, this study suggests an important role for TNF-α in contributing to many features of allergen induced airway remodeling including changes in levels of peribronchial smooth muscle, subepithelial fibrosis, and deposition of extracellular matrix.

Inactivation of IκB-kinase-β dependent genes in airway epithelium reduces tobacco smoke induced acute airway inflammation

We have examined the role of NF-κB regulated genes in airway epithelium in mediating tobacco smoke induced airway inflammation in studies of CC10-Cre tg / Ikkβ Δ/Δ mice in which NF-κB signaling through IκB-kinase-β (IKK-β) is selectively ablated in epithelial cells in the airway. CC10-Cre tg / Ikkβ Δ/Δ mice exposed to tobacco smoke for seven days had a significant decrease in the number of BAL cells (total cells, neutrophils, and macrophages) as well as significantly reduced numbers of peribronchial cells (F4/80+ and myeloperoxidase+) compared to tobacco exposed WT mice. In addition to the reduction in peribronchial cells, CC10-Cre tg / Ikkβ Δ/Δ mice exposed to tobacco smoke had a significant decrease in the number of macrophages and neutrophils in the alveolar space suggesting that inactivation of NF-κB in the airway epithelium influenced the number of neutrophils and macrophages recruited to the alveolus. Levels of the NF-κB regulated chemokines KC and MCP-1 were significantly reduced in lungs of tobacco smoke exposed CC10-Cre tg / Ikkβ Δ/Δ mice compared to tobacco exposed WT mice. In contrast, there was no significant difference in levels of NF-κB regulated MIP-1α between CC10-Cre tg / Ikkβ Δ/Δ and WT mice. Lung sections of tobacco smoke exposed CC10-Cre tg / Ikkβ Δ/Δ mice immunostained with KC or MCP-1 antibodies demonstrated reduced expression of these chemokines in the airway epithelium, but not in alveolar epithelium. Overall, these studies demonstrate an important role for NF-κB regulated genes in airway epithelium in contributing to acute tobacco smoke induced airway inflammation not only in the peribronchial space but also in the alveolar space.

The effects of oxidative stress induced by prolonged low-dose diesel exhaust particle exposure on the generation of allergic airway inflammation differ between BALB/c and C57BL/6 mice

We have recently reported that airway inflammatory responses to the oxidative stress induced by prolonged low-dose diesel exhaust particle (DEP) exposure differ markedly between BALB/c and C57BL/6 mice. In the present study, the effects of genetic differences in the response to prolonged low-dose DEP exposure on the generation of ovalbumin-induced allergic airway inflammation were further explored using the same mouse strains. In BALB/c mice, eosinophils and mucous goblet cells in histopathological pulmonary specimens increased significantly after DEP exposure, and were more marked than in C57BL/6 mice. Interleukin (IL)-5 and IL-13 levels in bronchoalveolar lavage (BAL) fluid were increased significantly by DEP exposure only in BALB/c mice. The DEP-induced increases in peribronchial eosinophils and mucous goblet cells in the lung tissues, and of IL-5 and IL-13 in the BAL fluid, were significantly attenuated by the antioxidant N-acetylcysteine. Thus, the effects of prolonged low-dose DEP exposure on the generation of allergic airway inflammation differed markedly between the mouse strains. These differences may be caused by different antioxidant responses to the oxidative stress induced by DEP exposure. Our results contribute more information to the search for genetic susceptibility factors in the response to DEP, and may thus assist in the discovery of new biomarkers for DEP-related disease.

Pneumonia enzoótica em javalis (Sus scrofa)

O objetivo desse estudo foi descrever o quadro clínico e epidemiológico, os achados patológicos, bacteriológicos e imuno-histoquímicos de um surto de pneumonia em uma granja de Javalis do Distrito Federal, Brasil. Em um período de cinco meses, morreram 90 javalis. Desses, 63 tinham lesões pulmonares. Clinicamente apresentavam atraso no desenvolvimento corporal, diminuição do apetite, letargia, tosse e dificuldade respiratória, principalmente quando movimentados. Constatou-se elevação da temperatura, 40ºC em média. Na auscultação, havia crepitações e estertores pulmonares de intensidade moderada. As alterações macroscópicas nos pulmões analisados eram típicas de broncopneumonia lobular. As lesões caracterizavam-se por consolidação crânio-ventral na maioria dos pulmões. A coloração variava de difusamente vermelho-escuro a um padrão mosaico (lóbulos vermelho-escuros intercalados por lóbulos cinzas) ou difusamente acinzentados. Na maioria dos pulmões observou-se exsudato mucopurulento na luz dos brônquios e fluindo do parênquima. Histologicamente, as alterações eram de broncopneumonia purulenta e histiocitária com focos de necrose. Em alguns animais havia também hiperplasia do BALT e, na maioria dos animais, infiltração linfocítica perivascular e peribronquial. Bordetella bronchiseptica e Streptococcus spp. foram as principais bactérias isoladas. A imuno-histoquímica demonstrou a bactéria Mycoplasma hyopneumoniae no epitélio bronquiolar e bronquial e o DNA desta bactéria foi detectado pela PCR. Este é o primeiro relato de broncopneumonia em Javalis associado à infecção por M. hyopneumoniae.

PI3Kγ-deficient mice have reduced levels of allergen-induced eosinophilic inflammation and airway remodeling

In this study, we have examined the role of phosphoinositide 3 kinase gamma (PI3Kgamma), a class Ib PI3K, in contributing to airway remodeling utilizing PI3Kgamma-deficient mice exposed to chronic allergen challenge. Wild-type (WT) mice sensitized to ovalbumin (OVA) and chronically challenged with OVA for 1 mo developed significantly increased levels of eosinophilic inflammation and airway remodeling. In contrast, PI3Kgamma-deficient mice challenged with OVA had significantly reduced numbers of bronchoalveolar lavage and peribronchial eosinophils compared with WT mice. There was no significant difference in the number of bone marrow or circulating peripheral blood eosinophils when comparing WT mice and PI3Kgamma-deficient mice, suggesting that trafficking of eosinophils into the lung was reduced in PI3Kgamma-deficient mice. PI3Kgamma-deficient and WT mice had similar levels of IL-5 and eotaxin-1. The reduced eosinophil recruitment to the airway in PI3Kgamma-deficient mice challenged with OVA was associated with significantly reduced numbers of TGF-beta1+ peribronchial cells, reduced numbers of pSmad 2/3+ airway epithelial cells, and pSmad 2/3+ peribronchial cells, as well as significantly reduced levels of peribronchial fibrosis (quantitated by trichrome staining and image analysis as well as by lung collagen levels). In addition, the area of peribronchial alpha-smooth muscle staining was significantly reduced in PI3Kgamma-deficient compared with WT mice. Overall, this study demonstrates an important role for PI3Kgamma in mediating allergen-induced eosinophilic airway inflammation and airway remodeling, suggesting that PI3Kgamma may be a novel therapeutic target in asthma.

Coexposure to Environmental Tobacco Smoke Increases Levels of Allergen-Induced Airway Remodeling in Mice

Environmental tobacco smoke (ETS) can increase asthma symptoms and the frequency of asthma attacks. However, the contribution of ETS to airway remodeling in asthma is at present unknown. In this study, we have used a mouse model of allergen-induced airway remodeling to determine whether the combination of chronic exposure to ETS and chronic exposure to OVA allergen induces greater levels of airway remodeling than exposure to either chronic ETS or chronic OVA allergen alone. Mice exposed to chronic ETS alone did not develop significant eosinophilic airway inflammation, airway remodeling, or increased airway hyperreactivity to methacholine. In contrast, mice exposed to chronic OVA allergen had significantly increased levels of peribronchial fibrosis, increased thickening of the smooth muscle layer, increased mucus, and increased airway hyperreactivity which was significantly enhanced by coexposure to the combination of chronic ETS and chronic OVA allergen. Mice coexposed to chronic ETS and chronic OVA allergen had significantly increased levels of eotaxin-1 expression in airway epithelium which was associated with increased numbers of peribronchial eosinophils, as well as increased numbers of peribronchial cells expressing TGF-beta1. These studies suggest that chronic coexposure to ETS significantly increases levels of allergen-induced airway remodeling (in particular smooth muscle thickness) and airway responsiveness by up-regulating expression of chemokines such as eotaxin-1 in airway epithelium with resultant recruitment of cells expressing TGF-beta1 to the airway and enhanced airway remodeling.

Remodeling associated expression of matrix metalloproteinase 9 but not tissue inhibitor of metalloproteinase 1 in airway epithelium: Modulation by immunostimulatory DNA

Matrix metalloproteinase 9 (MMP-9) and its tissue inhibitor of metalloproteinase 1 (TIMP-1) are hypothesized to play a role in the pathogenesis of airway remodeling in asthma. We have used a mouse model of airway remodeling to determine the pattern of expression of MMP-9 and TIMP-1 in airway epithelium and peribronchial cells, and assess whether TIMP-1, an inhibitor of MMP-9, is expressed at the same sites in the airway. In addition, we have investigated whether immunostimulatory sequences (ISSs) of DNA modulate levels of expression of MMP-9, TIMP-1, and peribronchial fibrosis. Levels of lung MMP-9 and TIMP-1 were assessed by zymography, ELISA, and immunohistochemistry. Repetitive ovalbumin challenge induced a significant increase in levels of MMP-9, TIMP-1, and peribronchial collagen deposition. The pattern of expression of MMP-9 and TIMP-1 in the remodeled airway was significantly different. MMP-9 but not TIMP-1 was expressed in airway epithelium, whereas both MMP-9 and TIMP-1 were expressed in peribronchial inflammatory cells. ISS significantly reduced expression of MMP-9 in airway epithelium (which immunostained positive for Toll receptor 9), as well as in peribronchial inflammatory cells. In vitro studies demonstrated that ISS inhibited bone marrow macrophage generation of MMP-9. Allergen-induced peribronchial fibrosis is associated with expression of MMP-9 and TIMP-1 at different anatomical sites in the remodeled airway. The ability of ISS to inhibit the expression of MMP-9 in airway epithelium (a site where its inhibitor TIMP-1 is not induced by allergen challenge) may be important in determining whether ISS contributes to reductions in airway remodeling by reducing levels of MMP-9. Immunostimulatory sequences of DNA, which are being investigated as novel therapeutics in asthma, inhibit airway remodeling in mice as well as epithelial expression of MMP-9, an enzyme that degrades the extracellular matrix proteins surrounding the airway.

Immunostimulatory DNA inhibits allergen-induced peribronchial angiogenesis in mice

Airway remodeling in asthma is associated with angiogenesis. We have examined whether immunostimulatory sequences of DNA (ISSs) inhibit allergen-induced airway angiogenesis and expression of angiogenic cytokines in a mouse model of airway remodeling. Mice sensitized to ovalbumin were challenged repetitively with ovalbumin for three months to develop airway remodeling and angiogenesis. Levels of angiogenesis were compared in ISS-treated and control mice. Mice challenged with ovalbumin developed significantly increased levels of peribronchial angiogenesis (increase in the number of CD31+ peribronchial small blood vessels) and an increase in the peribronchial vascular area as assessed by image analysis. Ovalbumin-induced peribronchial angiogenesis was associated with increased bronchoalveolar lavage levels of vascular endothelial growth factor (VEGF) and an increase in the number of peribronchial cells expressing VEGF. Treatment of mice with ISS before repetitive ovalbumin challenge significantly reduced the levels of peribronchial angiogenesis as well as the levels of bronchoalveolar lavage VEGF and the number of peribronchial cells expressing VEGF. ISS is unlikely to act directly on endothelial cells to inhibit angiogenesis because lung endothelial cells did not express Toll receptor 9, the receptor for ISS as assessed by RT-PCR. In vitro studies demonstrated that ISS inhibited macrophage expression of VEGF. The ability of ISS to inhibit angiogenesis in vivo is likely to be mediated by several mechanisms, including ISS reducing the number of peribronchial inflammatory cells that express VEGF, ISS inhibiting expression of TH2 cytokines such as IL-13 that promote VEGF expression, and direct effects of ISS on macrophages to inhibit VEGF expression.

Allergen-induced peribronchial fibrosis and mucus production mediated by IκB kinase β-dependent genes in airway epithelium

In response to inflammation or injury, airway epithelial cells express inducible genes that may contribute to allergen-induced airway remodeling. To determine the contribution of epithelial cell NF-kappaB activation to the remodeling response, we generated CC10-Cre(tg)/Ikkbeta(delta/delta) mice in which NF-kappaB signaling through IkappaB kinase beta (IKKbeta) is selectively ablated in the airway epithelium by conditional Cre-recombinase expression from the Clara cell (CC10) promoter. Repetitive ovalbumin challenge of mice deficient in airway epithelial IKKbeta prevented nuclear translocation of the RelA NF-kappaB subunit only in airway epithelial cells, resulting in significantly lower peribronchial fibrosis in CC10-Cre(tg)/Ikkbeta(delta/delta) mice compared with littermate controls as assessed by peribronchial trichrome staining and total lung collagen content. Levels of airway mucus, airway eosinophils, and peribronchial CD4+ cells in ovalbumin-challenged mice were also reduced significantly upon airway epithelial Ikkbeta ablation. The diminished inflammatory response was associated with reduced expression of NF-kappaB-regulated chemokines, including eotaxin-1 and thymus- and activation-regulated chemokine, which attract eosinophils and Th2 cells, respectively, into the airway. The number of peribronchial cells expressing TGF-beta1, as well as TGF-beta1 amounts in bronchoalveolar lavage, were also significantly reduced in mice deficient in airway epithelium IKKbeta. Overall, these studies show an important role for NF-kappaB regulated genes in airway epithelium in allergen-induced airway remodeling, including peribronchial fibrosis and mucus production.

Inhibition of airway remodeling in IL-5-deficient mice.

To determine the role of IL-5 in airway remodeling, IL-5-deficient and WT mice were sensitized to OVA and challenged by repetitive administration of OVA for 3 months. IL-5-deficient mice had significantly less peribronchial fibrosis (total lung collagen content, peribronchial collagens III and V) and significantly less peribronchial smooth muscle (thickness of peribronchial smooth muscle layer, alpha-smooth muscle actin immunostaining) compared with WT mice challenged with OVA. WT mice had a significant increase in the number of peribronchial cells staining positive for major basic protein and TGF-beta. In contrast, IL-5-deficient mice had a significant reduction in the number of peribronchial cells staining positive for major basic protein, which was paralleled by a similar reduction in the number of cells staining positive for TGF-beta, suggesting that eosinophils are a significant source of TGF-beta in the remodeled airway. OVA challenge induced significantly higher levels of airway epithelial alphaVbeta6 integrin expression, as well as significantly higher levels of bioactive lung TGF-beta in WT compared with IL-5-deficient mice. Increased airway epithelial expression of alphaVbeta6 integrin may contribute to the increased activation of latent TGF-beta. These results suggest an important role for IL-5, eosinophils, alphaVbeta6, and TGF-beta in airway remodeling.