Preferential binding of lysozyme to elastic fibres in pulmonary emphysema

Protective Abilities of an Inhaled DPI Formulation Based on Sodium Hyaluronate against Environmental Hazards Targeting the Upper Respiratory Tract

The exposure of lung epithelium to environmental hazards is linked to several chronic respiratory diseases. We assessed the ability of an inhaled dry powder (DPI) medical device product (PolmonYDEFENCE/DYFESA^TM, SOFAR SpA, Trezzano Rosa, Italy), using a formulation of sodium hyaluronate (Na-Hya) as the key ingredient as a defensive barrier to protect the upper respiratory tract. Specifically, it was evaluated if the presence of the barrier formed by sodium hyaluronate present on the cells, reducing direct contact of the urban dust (UD) with the surface of cells can protect them in an indirect manner by the inflammatory and oxidative process started in the presence of the UD. Cytotoxicity and the protection capability against the oxidative stress of the product were tested in vitro using Calu-3 cells exposure to UD as a trigger for oxidative stress. Inflammation and wound healing were assessed using an air-liquid interface (ALI) culture model of the Calu-3 cells. Deposition studies of the formulation were conducted using a modified Anderson cascade impactor (ACI) and the monodose PillHaler^® dry powder inhaler (DPI) device, Na-Hya was detected and quantified using high-performance-liquid-chromatography (HPLC). Solubilised PolmonYDEFENCE/DYFESA^TM gives protection against oxidative stress in Calu-3 cells in the short term (2 h) without any cytotoxic effects. ALI culture experiments, testing the barrier-forming (non-solubilised) capabilities of PolmonYDEFENCE/DYFESA^TM, showed that the barrier layer reduced inflammation triggered by UD and the time for wound closure compared to Na-Hya alone. Deposition experiments using the ACI and the PillHaler^® DPI device showed that the majority of the product was deposited in the upper part of the respiratory tract. Finally, the protective effect of the product was efficacious for up to 24 h without affecting mucus production. We demonstrated the potential of PolmonYDEFENCE/DYFESA^TM as a preventative barrier against UD, which may aid in protecting the upper respiratory tract against environmental hazards and help with chronic respiratory diseases.

Use of Hyaluronic Acid (HA) in Chronic Airway Diseases

Hyaluronic acid (HA) is a key component of the extracellular matrix of the lungs. A unique attribute of HA is its water-retaining properties, so HA has a major role in the regulation of fluid balance in the lung interstitium. Hyaluronic acid has been widely used in the treatment of eyes, ears, joints and skin disorders, but in the last years, it has been also proposed in the treatment of certain lung diseases, including airway diseases, due to its anti-inflammatory and water-binding capacities. Hyaluronic acid aerosol decreases the severity of elastase-induced emphysema in murine models, prevents bronchoconstriction in asthmatics and improves some functional parameters in chronic obstructive pulmonary disease (COPD) patients. Due to the protection of HA against bronchoconstriction and its hydration properties, inhaled HA would increase the volume of airway surface liquid, resulting in mucus hydration, increased mucous transport and less mucous plugging of the airways. In addition, it has been seen in human studies that the treatment with nebulised HA improves the tolerability of nebulised hypertonic saline (even at 6% or 7% of concentration), which has been demonstrated to be an effective treatment in bronchial secretion management in patients with cystic fibrosis and bronchiectasis. Our objective is to review the role of HA treatment in the management of chronic airway diseases.

CD44 mediates stem cell mobilization to damaged lung via its novel transcriptional targets, Cortactin and Survivin

Beyond their role in bone and lung homeostasis, mesenchymal stem cells (MSCs) are becoming popular in cell therapy. Various insults may disrupt the repair mechanisms involving MSCs. One such insult is smoking, which is a major risk factor for osteoporosis and respiratory diseases. Upon cigarette smoke-induced damage, a series of reparatory mechanisms ensue; one such mechanism involves Glycosaminoglycans (GAG). One of these GAGs, namely hyaluronic acid (HA), serves as a potential therapeutic target in lung injury. However, much of its mechanisms of action through its major receptor CD44 remains unexplored. Our previous studies have identified and functionally validated that both cortactin (CTTN: marker of motility) and Survivin (BIRC5: required for cell survival) act as novel HA/CD44-downstream transcriptional targets underpinning cell motility. Here, human MSCs were treated with "Water-pipe" smoke to investigate the effects of cigarette smoke condensate (CSC) on these HA-CD44 novel signaling pathways. Our results show that CSC decreased the expression of both CD44 and its downstream targets CTTN and BIRC5 in MSCs, and that HA reversed these effects. Interestingly, CSC inhibited migration and invasion of MSCs upon CD44-targeted RNAi treatment. This shows the importance of CD44-HA/CTTN and CD44-HA/BIRC5 signaling pathways in MSC motility, and further suggests that these signaling pathways may provide a novel mechanism implicated in migration of MSCs during repair of lung tissue injury. These findings suggest that one should use caution before utilizing MSC from donors with history of smoking, and further pave the way towards the development of targeted therapeutic approaches against CD44-associated diseases.

A potential novel therapy for FGFR1-amplified pancreatic cancer with bone metastasis, screened by next-generation sequencing and a patient-derived xenograft model

Effective therapies are limited for pancreatic cancer, particularly for those with distant tumour metastases. Therefore, more individualised drug screening is urgently required. Next-generation sequencing (NGS) is a powerful tool to investigate the genomic landscape of patients and the mechanism of drug response, which may provide a broader vision for potential clinical drug screening. Patient-derived xenograft (PDX) models may have a significant advantage in predicting clinical treatment response. In our previous study, a PDX of pancreatic cancer bone metastasis was established, and NGS was conducted to investigate the molecular information. In the present study, these data were further analysed and fibroblast growth factor receptor 1 (FGFR1) amplification was identified in a panel of 416 cancer-associated genes. Thus, AZD4547, an inhibitor against FGFR, was selected as a potential therapy, and was evaluated using the PDX model. AZD4547 was shown to exhibit antitumor activity by reducing the expression of FGFR1 and its targets. The present study also demonstrated the high potential of the novel NGS/PDX-based drug screening platform to improve individualised cancer treatment.

The Therapeutic Potential of Hyaluronan in COPD

Insights into the clinical course of COPD indicate the need for new therapies for this condition. The discovery of alpha-1 antitrypsin deficiency (AATD) led to the protease-antiprotease imbalance hypothesis, which was applied to COPD related to AATD as well as COPD not related to AATD. The discovery of AATD brought recognition to the importance of elastin fibers in maintaining lung matrix structure. Two cross-linking amino acids, desmosine and isodesmosine (DI), are unique to mature elastin and can serve as biomarkers of the degradation of elastin. The intravenous augmentation treatment and lung density in severe alpha-1 antitrypsin deficiency (RAPID) study shows a correlation of an anatomic index of COPD (on CT imaging) correlating with a chemical indicator of matrix injury in COPD, DI. The results suggest that preservation of lung elastin structure may slow the progression of COPD. Hyaluronan aerosol decreases the severity of elastase-induced emphysema in animals and has induced reductions in DI levels in preliminary human studies. Hyaluronan deserves further development as a therapy for COPD.

Does lysozyme play a role in the pathogenesis of COPD?

Elastic fiber injury is an important process in the pathogenesis of chronic obstructive pulmonary disease (COPD), particularly with regard to the development of pulmonary emphysema. Damage to these fibers results in uneven distribution of mechanical forces in the lung, leading to dilatation and rupture of alveolar walls. While the role of various enzymes and oxidants in this process has been well-documented, we propose that a previously unsuspected agent, lysozyme, may contribute significantly to the changes in elastic fibers observed in this disease. Studies from our laboratory have previously shown that lysozyme preferentially binds to elastic fibers in human emphysematous lungs. On the basis of this finding, it is hypothesized that the attachment of lysozyme to these fibers enhances their susceptibility to injury, and further impairs the transfer of mechanical forces in the lung, leading to increased alveolar wall damage and enhanced progression of COPD. The hypothesized effects of lysozyme are predicated on its interaction with hyaluronan (HA), a long-chain polysaccharide that is found in close proximity to elastic fibers. By preventing the binding of HA to elastic fibers in COPD, lysozyme may interfere with the protective effect of this polysaccharide against enzymes and oxidants that degrade these fibers. Furthermore, the loss of the hydrating effect of HA on these fibers may impair their elastic properties, greatly increasing the probability of their fragmentation in response to mechanical forces. The proposed hypothesis may explain why the content of HA is significantly lower in the lungs of COPD patients. It may also contribute to the design of clinical trials involving the use of exogenously administered HA as a potential treatment for COPD.

Serum lysozyme - a surrogate marker of pulmonary microvascular injury in smokers?

Progression rate of disease processes in smoke-induced lung injuries varies greatly. Diverse pathophysiological mechanisms may trigger these divergences. The aim of this study was to evaluate whether circulating markers of monocytes/macrophages and/or neutrophil [i.e. lysozyme (LZM) or myeloperoxidase (MPO)] were associated with reduced values of diffusion capacity (DL,CO), which is considered to serve as a mirror of pulmonary microvascular derangement and an early sign of tissue remodelling in smokers. Data obtained from 134 smokers (GOLD stage ≤1) and 24 matched healthy non-smoking volunteers were evaluated in a cross-sectional study design. Lung function tests as well as single breath test of DL,CO were assessed according to ATS/ERS guidelines. Biomarkers were measured in serum by means of sensitive immunoassays. A subgroup of smokers with normal lung function was created to minimize confounding, by excluding datasets showing significant airflow limitation and abnormally high values of carboxy haemoglobin (COHb), the latter indicating recent smoking. The capacity of serum lysozyme to correctly identify abnormally low values of DL,CO (i.e. <1·9SD units), tended to be higher than that of Myeloperoxidase as assessed by analyses of receiver operated curves (ROC; AUC 0·81, 95%CI: 0·69-0·89 versus AUC 0·67, 95%CI: 0·60-0·81). It is concluded that serum levels of lysozyme, reflecting mainly activated monocytes/macrophages but also neutrophils, were significantly associated with isolated decrements of DL,CO in smokers with normal lung function tests. This suggests monocytes/macrophages to have a significant mechanistic role in early phases of the disease process and/or pulmonary microvascular damage.

Elastofibroma: Diagnosis and Treatment of Six Cases

Elastofibroma is a rare, benign pseudotumor that arises from connective tissue, most commonly found at the right scapular tip. These tumors usually can be distinguished from malignant soft-tissue tumors by their anatomical location and also through imaging techniques. Although elastofibroma is rare, it is important for surgeons to be aware of this diagnosis to prevent unnecessary biopsies and unnecessary operations. We report a series of six patients, four of whom were female, with a median age of 62.5 years, diagnosed with and treated for elastofibroma. Five of the six patients had unilateral lesions, while one patient had bilateral elastofibromas. All unilateral lesions were found on the right side. The elastofibroma in five of six patients was located on the subscapular tip, the remaining patient's elastofibroma was found on the chest wall external to the pleural surface. The pathogenesis of this lesion is discussed, as recent evidence suggests a neoplastic origin to elastofibroma. Additionally, cellular changes occurring in elastofibroma may reflect the pathogenesis of other disorders of elastic fibers.

The defensive role of lysozyme in human gingiva in inflammatory periodontal disease

BACKGROUND AND OBJECTIVE

The presence of lysozyme in human gingiva has not previously been demonstrated. In this study, we looked for evidence for the potential role of lysozyme as a protector of gingival elastic fibres. The objective of this study was also to determine the ex vivo susceptibility to hydrolysis of gingival elastic fibres from patients with or without periodontal disease by human leukocyte elastase and by human cathepsin G.

MATERIALS AND METHODS

Using gingival tissue sections from eight control, 10 gingivitis and 10 periodontitis patients, we evaluated the area fraction occupied by gingival elastic fibres (after selective staining) by the use of automated image analysis. In the ex vivo experiments, serial tissue sections from four control, four gingivitis, four young periodontitis and four aged periodontitis patients were submitted to the action of human leukocyte elastase and cathepsin G, after which enzymatic activities were determined by image analysis. Indirect immunodetection of lysozyme was also done on tissue sections for all patients included in this study.

RESULTS

Large variations of the area fraction occupied by elastic fibres were observed in human gingiva from young and aged patients with and without periodontal disease. In control and gingivitis patients, leukocyte elastase and cathepsin G had high comparable elastin solubilizing activities. With young and aged periodontitis patients, the two serine proteinases had weak elastin solubilizing activities. Lysozyme appeared to be present at the periphery of gingival elastic fibres in periodontitis patients.

CONCLUSION

Lysozyme can be considered an important natural protector of elastic fibres in pathological gingiva.

Elastofibroma: clonal fibrous proliferation with predominant CD34-positive cells

Elastofibroma is a rare fibrous lesion that most commonly occurs in periscapular soft tissues and is characterized by accumulated abnormal elastic fibers. Although the lesion is generally regarded as a reactive process, an unusual fibroblastic pseudotumor, or as a fibroelastic tumor-like lesion, its etiology remains largely unknown. Recent cytogenetic demonstrations of chromosomal instability and some recurrent or clonal chromosomal changes have raised the possibility that the lesion represents a neoplastic process. We analyzed 14 cases of elastofibroma to further explore, morphologically and genetically, the characteristics of its cellular composition. The interspersed spindle or stellate cells showed a fibroblast-like appearance and were almost consistently positive for vimentin and frequently positive for CD34 and lysozyme immunohistochemically. No spindle cells of myofibroblastic phenotype were recognized. To assess the clonality of the lesions in female patients, the X-linked polymorphic human androgen receptor gene assay was performed using formalin-fixed, paraffin-embedded tissues. A nonrandom inactivation of the androgen receptor gene was detected in two informative cases. Thus, these findings suggest that CD34-positive mesenchymal cells are an integral component of elastofibroma, which represents a clonal fibrous proliferation.

The effect of lysozyme on elastase-mediated injury

Previous studies by this laboratory demonstrated that lysozyme is increased in human pulmonary emphysema, and that it preferentially binds to elastic fibers, which undergo degradation in this disease. In the current investigation, the relationship between lysozyme and elastic fiber injury was further examined, both in vitro and in vivo. The effect of exogenously administered egg-white lysozyme on pancreatic elastase-induced injury was determined using a biosynthetically radiolabeled extracellular matrix preparation mainly composed of elastic fibers. Although matrix treated with lysozyme showed attachment of the protein to elastic fibers, there was no significant increase in elastolysis compared with untreated controls following exposure to either 1 microg/ml or 100 ng/ml of pancreatic elastase. However, lysozyme did impair the ability of hyaluronan (HA) to prevent elastase injury to elastic fibers. Matrix samples sequentially treated with lysozyme and HA, then incubated with 1 microg/ml or 100 ng/ml of pancreatic elastase, showed significantly increased elastolysis compared with those treated with HA alone. Since HA is closely associated with elastic fibers in vivo, the ability of lysozyme to enhance elastolysis was further tested in an animal model of emphysema induced by intratracheal administration of porcine pancreatic elastase. Animals exposed to aerosolized lysozyme prior to elastase administration showed significantly increased airspace enlargement. The mean linear intercept of the lysozyme-treated animals was 123 microm compared with 75 microm for controls receiving aerosolized water (P < 0.0001). These findings suggest that lysozyme may not be an innocuous component of the inflammatory response associated with pulmonary emphysema, but may actually play a role in the pathogenesis of the disease.

The effect of hyaluronan on elastic fiber injury in vitro and elastase-induced airspace enlargement in vivo

This laboratory has previously described a method of preventing air-space enlargement in experimental pulmonary emphysema using aerosolized hyaluronan (HA). Although it was found that HA preferentially binds to elastic fibers (which undergo breakdown by elastases in emphysema), it remains to be shown that such attachment actually prevents damage to the fibers. In the current study, cell-free radiolabeled extracellular matrices, derived from rat pleural mesothelial cells, were used to test the ability of low molecular weight ( approximately 100 kDa) streptococcal HA to prevent elastolysis. Coating the matrices with HA significantly decreased elastolysis (P<0.05) induced by porcine pancreatic elastase (43%), human neutrophil elastase (53%), and human macrophage metalloelastase (80%). Concomitant in vivo studies examined the ability of an aerosol preparation of the streptococcal HA to prevent experimental emphysema induced by intratracheal administration of porcine pancreatic elastase. As seen with earlier studies involving bovine tracheal HA, a single aerosol exposure significantly decreased elastase-induced airspace enlargement, as measured by the mean linear intercept (107.5 vs 89.6 microm; P < 0. 05). Furthermore, repeated exposure to the HA aerosol for 1 month did not reveal any morphological changes in the lung. The results provide further evidence that aerosolized HA may be an effective means of preventing pulmonary emphysema and perhaps other lung diseases that involve elastic fiber injury.