Mucus Structure, Viscoelastic Properties, and Composition in Chronic Respiratory Diseases.

The respiratory mucus, a viscoelastic gel, effectuates a primary line of the airway defense when operated by the mucociliary clearance. In chronic respiratory diseases (CRDs), such as asthma, chronic obstructive pulmonary disease (COPD), and cystic fibrosis (CF), the mucus is overproduced and its solid content augments, changing its structure and viscoelastic properties and determining a derangement of essential defense mechanisms against opportunistic microbial (virus and bacteria) pathogens. This ensues in damaging of the airways, leading to a vicious cycle of obstruction and infection responsible for the harsh clinical evolution of these CRDs. Here, we review the essential features of normal and pathological mucus (i.e., sputum in CF, COPD, and asthma), i.e., mucin content, structure (mesh size), micro/macro-rheology, pH, and osmotic pressure, ending with the awareness that sputum biomarkers (mucins, inflammatory proteins and peptides, and metabolites) might serve to indicate acute exacerbation and response to therapies. There are some indications that old and novel treatments may change the structure, viscoelastic properties, and biomarker content of sputum; however, a wealth of work is still needed to embrace these measures as correlates of disease severity in association with (or even as substitutes of) pulmonary functional tests.

Solanum lycopersicum (Tomato)-Derived Nanovesicles Accelerate Wound Healing by Eliciting the Migration of Keratinocytes and Fibroblasts.

Plant-derived nanovesicles have been considered interesting in medicine for their breakthrough biological effects, including those relevant to wound healing. However, tomato-derived nanovesicles (TDNVs) have not been studied for their effects on wound closure yet. TDNVs were isolated from Solanum lycopersicum (var. Piccadilly) ripe tomatoes by ultracentrifugation. Extract (collected during the isolation procedure) and NVs (pellet) were characterized by transmission electron microscopy and laser Doppler electrophoresis. Wound healing in the presence of Extract or NVs was analyzed by a scratch assay with monocultures of human keratinocytes (HUKE) or NIH-3T3 mouse fibroblasts. Cell proliferation and migration were studied by MTT and agarose spot assay, respectively. The vesicles in the Extract and NV samples were nanosized with a similar mean diameter of 115 nm and 130 nm, respectively. Both Extract and NVs had already accelerated wound closure of injured HUKE and NIH-3T3 monocultures by 6 h post-injury. Although neither sample exerted a cytotoxic effect on HUKE and NIH-3T3 fibroblasts, they did not augment cell proliferation. NVs and the Extract increased cell migration of both cell types. NVs from tomatoes may accelerate wound healing by increasing keratinocyte and fibroblast migration. These results indicate the potential therapeutic usefulness of TDNVs in the treatment of chronic or hard-to-heal ulcers.

The Oncogenic Theory of Preeclampsia: Is Amniotic Mesenchymal Stem Cells-Derived PLAC1 Involved?

The pathomechanisms of preeclampsia (PE), a complication of late pregnancy characterized by hypertension and proteinuria, and due to improper placentation, are not well known. Mesenchymal stem cells derived from the amniotic membrane (AMSCs) may play a role in PE pathogenesis as placental homeostasis regulators. PLACenta-specific protein 1 (PLAC1) is a transmembrane antigen involved in trophoblast proliferation that is found to be associated with cancer progression. We studied PLAC1 in human AMSCs obtained from control subjects (n = 4) and PE patients (n = 7), measuring the levels of mRNA expression (RT-PCR) and secreted protein (ELISA on conditioned medium). Lower levels of PLAC1 mRNA expression were observed in PE AMSCs as compared with Caco2 cells (positive controls), but not in non-PE AMSCs. PLAC1 antigen was detectable in conditioned medium obtained from PE AMSCs, whereas it was undetectable in that obtained from non-PE AMSCs. Our data suggest that abnormal shedding of PLAC1 from AMSC plasma membranes, likely by metalloproteinases, may contribute to trophoblast proliferation, supporting its role in the oncogenic theory of PE.

Polymer Encapsulated Liposomes for Oral Co-Delivery of Curcumin and Hydroxytyrosol.

Curcumin (Cur) is a hydrophobic polyphenol from the rhizome of Curcuma spp., while hydroxytyrosol (HT) is a water-soluble polyphenol from Olea europaea. Both show outstanding antioxidant properties but suffer from scarce bioavailability and low stability in biological fluids. In this work, the co-encapsulation of Cur and HT into liposomes was realized, and the liposomal formulation was improved using polymers to increase their survival in the gastrointestinal tract. Liposomes with different compositions were formulated: Type 1, composed of phospholipids and cholesterol; Type 2, also with a PEG coating; and Type 3 providing an additional shell of Eudragit® S100, a gastro-resistant polymer. Samples were characterized in terms of size, morphology, ζ-potential, encapsulation efficiency, and loading capacity. All samples were subjected to a simulated in vitro digestion and their stability was investigated. The Eudragit®S100 coating demonstrated prevention of early releases of HT in the mouth and gastric phases, while the PEG shell reduced bile salts and pancreatin effects during the intestinal digestion. In vitro antioxidant activity showed a cumulative effect for Cur and HT loaded in vesicles. Finally, liposomes with HT concentrations up to 40 µM and Cur up to 4.7 µM, alone or in combination, did not show cytotoxicity against Caco-2 cells.

Small-molecule drugs for cystic fibrosis: Where are we now?

The cystic fibrosis (CF) lung disease is due to the lack/dysfunction of the CF Transmembrane Conductance Regulator (CFTR), a chloride channel expressed by epithelial cells as the main regulator of ion and fluid homeostasis. More than 2000 genetic variation in the CFTR gene are known, among which those with identified pathomechanism have been divided into six mutation classes. A major advancement in the pharmacotherapy of CF has been the development of small-molecule drugs hitting the root of the disease, i.e. the altered ion and fluid transport through the airway epithelium. These drugs, called CFTR modulators, have been advanced to the clinics to treat nearly 90% of CF patients, including the CFTR potentiator ivacaftor, approved for residual function mutations (Classes III and IV), and combinations of correctors (lumacaftor, tezacaftor, elexacaftor) and ivacaftor for patients bearing at least one the F508del mutation, the most frequent mutation belonging to class II. To cover the 10% of CF patients without etiological therapies, other novel small-molecule CFTR modulators are in evaluation of their effectiveness in all the CFTR mutation classes: read-through agents for Class I, correctors, potentiators and amplifiers from different companies for Class II-V, stabilizers for Class VI. In alternative, other solute carriers, such as SLC26A9 and SLC6A14, are the focus of intensive investigation. Finally, other molecular targets are being evaluated for patients with no approved CFTR modulator therapy or as means of enhancing CFTR modulatory therapy, including small molecules forming ion channels, inhibitors of the ENaC sodium channel and potentiators of the calcium-activated chloride channel TMEM16A. This paper aims to give an up-to-date overview of old and novel CFTR modulators as well as of novel strategies based on small-molecule drugs. Further investigations in in-vivo and cell-based models as well as carrying out large prospective studies will be required to determine if novel CFTR modulators, stabilizers, amplifiers, and the ENaC inhibitors or TMEM16A potentiators will further improve the clinical outcomes in CF management.

Extracellular Vesicles' Role in the Pathophysiology and as Biomarkers in Cystic Fibrosis and COPD.

In keeping with the extraordinary interest and advancement of extracellular vesicles (EVs) in pathogenesis and diagnosis fields, we herein present an update to the knowledge about their role in cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD). Although CF and COPD stem from a different origin, one genetic and the other acquired, they share a similar pathophysiology, being the CF transmembrane conductance regulator (CFTR) protein implied in both disorders. Various subsets of EVs, comprised mainly of microvesicles (MVs) and exosomes (EXOs), are secreted by various cell types that are either resident or attracted in the airways during the onset and progression of CF and COPD lung disease, representing a vehicle for metabolites, proteins and RNAs (especially microRNAs), that in turn lead to events as such neutrophil influx, the overwhelming of proteases (elastase, metalloproteases), oxidative stress, myofibroblast activation and collagen deposition. Eventually, all of these pathomechanisms lead to chronic inflammation, mucus overproduction, remodeling of the airways, and fibrosis, thus operating a complex interplay among cells and tissues. The detection of MVs and EXOs in blood and biological fluids coming from the airways (bronchoalveolar lavage fluid and sputum) allows the consideration of EVs and their cargoes as promising biomarkers for CF and COPD, although clinical expectations have yet to be fulfilled.

Downregulation of exosomal let-7d and miR-16 in idiopathic pulmonary fibrosis.

BACKGROUND: Idiopathic Pulmonary Fibrosis (IPF) is a degenerative interstitial lung disease with both a poor prognosis and quality of life once the diagnosis is made. In the last decade many features of the disease have been investigated to better understand the pathological steps that lead to the onset of the disease and, moreover, different types of biomarkers have been tested to find valid diagnostic, prognostic and therapy response predictive ones. In the complexity of IPF, microRNA (miRNAs) biomarker investigation seems to be promising. METHODS: We analysed the expression of five exosomal miRNAs supposed to have a role in the pathogenesis of the disease from serum of a group of IPF patients (n = 61) and we compared it with the expression of the same miRNAs in a group of healthy controls (n = 15). RESULTS: In the current study what emerged is let-7d down-regulation and, unexpectedly, miR-16 significant down-regulation. Moreover, through a cross-sectional analysis, a clustering of the expression of miR-16, miR-21 and miR-26a was found. CONCLUSIONS: These findings could help the individuation of previously unknown key players in the pathophysiology of IPF and, most interestingly, more specific targets for the development of effective medications.

How Cells Communicate with Each Other in the Tumor Microenvironment: Suggestions to Design Novel Therapeutic Strategies in Cancer Disease.

Connexin- and pannexin (Panx)-formed hemichannels (HCs) and gap junctions (GJs) operate an interaction with the extracellular matrix and GJ intercellular communication (GJIC), and on account of this they are involved in cancer onset and progression towards invasiveness and metastatization. When we deal with cancer, it is not correct to omit the immune system, as well as neglecting its role in resisting or succumbing to formation and progression of incipient neoplasia until the formation of micrometastasis, nevertheless what really occurs in the tumor microenvironment (TME), which are the main players and which are the tumor or body allies, is still unclear. The goal of this article is to discuss how the pivotal players act, which can enhance or contrast cancer progression during two important process: "Activating Invasion and Metastasis" and the "Avoiding Immune Destruction", with a particular emphasis on the interplay among GJIC, Panx-HCs, and the purinergic system in the TME without disregarding the inflammasome and cytokines thereof derived. In particular, the complex and contrasting roles of Panx1/P2X7R signalosome in tumor facilitation and/or inhibition is discussed in regard to the early/late phases of the carcinogenesis. Finally, considering this complex interplay in the TME between cancer cells, stromal cells, immune cells, and focusing on their means of communication, we should be capable of revealing harmful messages that help the cancer growth and transform them in body allies, thus designing novel therapeutic strategies to fight cancer in a personalized manner.

Cyto/Biocompatibility of Dopamine Combined with the Antioxidant Grape Seed-Derived Polyphenol Compounds in Solid Lipid Nanoparticles.

Background: The loss of nigrostriatal neurons containing dopamine (DA) together with the "mitochondrial dysfunction" in midbrain represent the two main causes related to the symptoms of Parkinson's disease (PD). Hence, the aim of this investigation is to co-administer the missing DA and the antioxidant grape seed-derived proanthocyanidins (grape seed extract, GSE) in order to increase the levels of the neurotransmitter (which is unable to cross the Blood Brain Barrier) and reducing the oxidative stress (OS) related to PD, respectively. Methods: For this purpose, we chose Solid Lipid Nanoparticles (SLN), because they have been already proven to increase DA uptake in the brain. DA-SLN adsorbing GSE (GSE/DA-SLN) were formulated and subjected to physico-chemical characterization, and their cytocompatibility and protection against OS were examined. Results: GSE was found on SLN surface and release studies evidenced the efficiency of GSE in preventing DA autoxidation. Furthermore, SLN showed high mucoadhesive strength and were found not cytotoxic to both primary Olfactory Ensheathing and neuroblastoma SH-SY5Y cells by MTT test. Co-administration of GSE/DA-SLN and the OS-inducing neurotoxin 6-hydroxydopamine (100 µM) resulted in an increase of SH-SY5Y cell viability. Conclusions: Hence, SLN formulations containing DA and GSE may constitute interesting candidates for non-invasive nose-to-brain delivery.

Use of low field nuclear magnetic resonance to monitor lung inflammation and the amount of pathological components in the sputum of cystic fibrosis patients.

PURPOSE: To develop a novel approach to monitor lung ventilation/inflammation in cystic fibrosis (CF) patients. Lung assessment in CF patients is relevant given that most patients succumb to respiratory failure. Respiratory functional tests (forced expiratory volume in the first second; FEV1 ) and inflammatory markers are used to test pulmonary ventilation/inflammation, respectively. However, FEV1 is effort dependent and might be uncomfortable for CF patients. Furthermore, inflammatory marker detection is costly and not rapid. To overcome these limitations, we propose the measurement, by means of low field nuclear magnetic resonance, of the spin-spin relaxation time (T2m ) of water hydrogens present in CF patient sputum. In CF sputum, different biological components are pathologically increased and inversely related to lung functionality. Moreover, we showed that these components alter in a dose-dependent manner the T2m in synthetic CF sputum. METHODS: Sputum samples were obtained from 42 CF subjects by voluntary expectoration; FEV1 , C-reactive protein (CRP), blood neutrophil counts together with cytokine (tumor necrosis factor alpha [TNFα], interleukin [IL]-1ß, IL-4, and vascular endothelial growth factor) quantifications were then evaluated. RESULTS: In sputum samples, we observe that T2m directly correlates (rFEV1 = 0.44; P < 10-4 ; 169 samples) with FEV1 . Moreover, T2m inversely correlates with the circulating inflammation markers CRP/neutrophil number (rCRP = -0.44, P < 10-4 ; rNC = -0.37, P < 2 * 10-4 ; 103 and 86 samples, respectively) and with the sputum inflammatory cytokines TNFα/IL-ß1 (rTNFα = -0.72, P < 10-4 ; rIL-1ß = -0.685, P < 10-4 ; 27 samples). T2m variations also correspond to FEV1 values over time in defined patients. CONCLUSION: These findings, together with the fast, reliable, and simple determination of T2m , make our approach a novel tool potentially usable in the real world of CF patients.

Neovascularization is a key feature of liver fibrosis progression: anti-angiogenesis as an innovative way of liver fibrosis treatment.

Liver fibrosis affects over 100 million people in the world; it represents a multifactorial, fibro-inflammatory disorder characterized by exacerbated production of extracellular matrix with consequent aberration of hepatic tissue. The aetiology of this disease is very complex and seems to involve a broad spectrum of factors including the lifestyle, environment factors, genes and epigenetic changes. More evidences indicate that angiogenesis, a process consisting in the formation of new blood vessels from pre-existing vessels, plays a crucial role in the progression of liver fibrosis. Central to the pathogenesis of liver fibrosis is the hepatic stellate cells (HSCs) which represent a crossroad among inflammation, fibrosis and angiogenesis. Quiescent HSCs can be stimulated by a host of growth factors, pro-inflammatory mediators produced by damaged resident liver cell types, as well as by hypoxia, contributing to neoangiogenesis, which in turn can be a bridge between acute and chronic inflammation. As matter of fact, studies demonstrated that neutralization of vascular endothelial growth factor as well as other proangiogenic agents can attenuate the progression of liver fibrosis. With this review, our intent is to discuss the cause and the role of angiogenesis in liver fibrosis focusing on the current knowledge about the impact of anti-angiogenetic therapies in this pathology.

Insulin-Like Growth Factor Binding Protein 6 Is Secreted in Extracellular Vesicles upon Hyperthermia and Oxidative Stress in Dendritic Cells But Not in Monocytes.

Recently, insulin-like growth factor binding protein 6 (IGFBP-6) has been shown to play a putative role in the immune system, as monocyte-derived dendritic cells (Mo-DCs) are stimulated by hyperthermia to express IGFBP-6 at both the mRNA and protein levels. However, the presence of IGFBP-6 in extracellular vesicles (EVs) and whether other pro-inflammatory stimuli can induce IGFBP-6 expression in Mo-DCs are not known yet. In this brief report, we show that hyperthermia (39 °C) induces IGFBP-6 secretion associated with microvesicles and exosomes as early as 3 h. Moreover, free IGFBP-6 is found in conditioned media (CM) of hyperthermia- and H2O2-treated Mo-DCs, but not in CM obtained from monocytes similarly treated. These results show that diverse inflammatory stimuli can induce IGFBP-6 association with EVs and secretion in conditioned medium, indicating a role for IGFBP-6 in communication between immune cells.

A novel approach based on low-field NMR for the detection of the pathological components of sputum in cystic fibrosis patients.

PURPOSE: Development of a reliable, simple method to monitor lung condition in cystic fibrosis (CF) patients. Lung functionality assessment in CF patients is relevant, as most of them still die of respiratory failure. In lung mucus (sputum) of CF patients, components such as proteins, biopolymers, DNA, bacteria, and mucin are pathologically increased. As lung functionality is related to the amount of the pathological components in the sputum, their determination can help clinicians in monitoring lung condition and planning therapy. METHODS: Low-field NMR was used to evaluate the variation of the relaxation time (T2m ) of the water hydrogens present in CF sputum in relation to the amounts of the pathological components. Low-field NMR was tested in artificial samples (mucin or alginates), then in conditional sputum (saliva from healthy volunteers, added by different amounts of the pathological components), and finally in 12 patients' sputums, in which T2m was correlated to a commonly used lung monitoring test (i.e., forced expiratory volume in the first second). RESULTS: T2m significantly (P < 0.05) differed between samples with and without pathological components and between healthy and CF patients (P < 0.05), in which T2m correlated (r = 0.87) with FEV1 . CONCLUSIONS: The presented method can potentially become a valuable lung-monitoring tool in CF patients. Magn Reson Med 79:2323-2331, 2018. © 2017 International Society for Magnetic Resonance in Medicine.

Nanocomplexes for gene therapy of respiratory diseases: Targeting and overcoming the mucus barrier.

Gene therapy, i.e. the delivery and expression of therapeutic genes, holds great promise for congenital and acquired respiratory diseases. Non-viral vectors are less toxic and immunogenic than viral vectors, although they are characterized by lower efficiency. However, they have to overcome many barriers, including inflammatory and immune mediators and cells. The respiratory and airway epithelial cells, the main target of these vectors, are coated with a layer of mucus, which hampers the effective reaching of gene therapy vectors carrying either plasmid DNA or small interfering RNA. This barrier is thicker in many lung diseases, such as cystic fibrosis. This review summarizes the most important advancements in the field of non-viral vectors that have been achieved with the use of nanoparticulate (NP) systems, composed either of polymers or lipids, in the lung gene delivery. In particular, different strategies of targeting of respiratory and airway lung cells will be described. Then, we will focus on the two approaches that attempt to overcome the mucus barrier: coating of the nanoparticulate system with poly(ethylene glycol) and treatment with mucolytics. Our conclusions are: 1) Ligand and physical targeting can direct therapeutic gene expression in specific cell types in the respiratory tract; 2) Mucopenetrating NPs are endowed with promising features to be useful in treating respiratory diseases and should be now advanced in pre-clinical trials. Finally, we discuss the development of such polymer- and lipid-based NPs in the context of in vitro and in vivo disease models, such as lung cancer, as well as in clinical trials.

Correction of defective CFTR/ENaC function and tightness of cystic fibrosis airway epithelium by amniotic mesenchymal stromal (stem) cells.

Cystic fibrosis (CF) is caused by mutations in the CF transmembrane conductance regulator (CFTR) gene, with most of the mortality given by the lung disease. Human amniotic mesenchymal stromal (stem) cells (hAMSCs) hold great promise for regenerative medicine in the field of lung disease; however, their potential as therapeutics for CF lung disease has not been fully explored. In the present study, hAMSCs were analysed in co-cultures on Transwell filters with CF immortalized airway epithelial cells (CFBE41o- line) at different ratios to exploit their potency to resume basic defects associated with CF. The results show that F-actin content was increased in co-cultures as compared with CF cells and actin was reorganized to form stress fibres. Confocal microscopy studies revealed that co-cultures had a tendency of increased expression of occludin and ZO-1 at the intercellular borders, paralleled by a decrease in dextran permeability, suggestive of more organized tight junctions (TJs). Spectrofluorometric analysis of CFTR function demonstrated that hAMSC-CFBE co-cultures resumed chloride transport, in line with the appearance of the mature Band C of CFTR protein by Western blotting. Moreover, hAMSC-CFBE co-cultures, at a 1:5 ratio, showed a decrease in fluid absorption, as opposed to CFBE cell monolayers that displayed a great rate of fluid resorption from the apical side. Our data show that human amniotic MSCs can be used in co-culture with CF respiratory epithelial cells to model their engraftment into the airways and have the potential to resume a tight epithelium with partial correction of the CF phenotype.

Hematopoietic and mesenchymal stem cells for the treatment of chronic respiratory diseases: role of plasticity and heterogeneity.

Chronic lung diseases, such as cystic fibrosis (CF), asthma, and chronic obstructive pulmonary disease (COPD) are incurable and represent a very high social burden. Stem cell-based treatment may represent a hope for the cure of these diseases. In this paper, we revise the overall knowledge about the plasticity and engraftment of exogenous marrow-derived stem cells into the lung, as well as their usefulness in lung repair and therapy of chronic lung diseases. The lung is easily accessible and the pathophysiology of these diseases is characterized by injury, inflammation, and eventually by remodeling of the airways. Bone marrow-derived stem cells, including hematopoietic stem/progenitor cells (HSPCs) and mesenchymal stromal (stem) cells (MSCs), encompass a wide array of cell subsets with different capacities of engraftment and injured tissue regenerating potential. Proof-of-principle that marrow cells administered locally may engraft and give rise to specialized epithelial cells has been given, but the efficiency of this conversion is too limited to give a therapeutic effect. Besides the identification of plasticity mechanisms, the characterization/isolation of the stem cell subpopulations represents a major challenge to improving the efficacy of transplantation protocols used in regenerative medicine for lung diseases.

Irisin prevents trabecular bone damage and tumor invasion in a mouse model of multiple myeloma.

Bone disease associated with multiple myeloma (MM) is characterized by osteolytic lesions and pathological fractures, which remain a therapeutic priority despite new drugs improving MM patient survival. Antiresorptive molecules represent the main option for the treatment of MM-associated bone disease (MMBD), whereas osteoanabolic molecules are under investigation. Among these latter, we here focused on the myokine irisin, which is able to enhance bone mass in healthy mice, prevent bone loss in osteoporotic mouse models, and accelerate fracture healing in mice. Therefore, we investigated irisin effect on MMBD in a mouse model of MM induced by intratibial injection of myeloma cells followed by weekly administration of 100 µg/kg of recombinant irisin for 5 wk. By micro-Ct analysis, we demonstrated that irisin improves MM-induced trabecular bone damage by partially preventing the reduction of femur Trabecular Bone Volume/Total Volume (P = .0028), Trabecular Number (P = .0076), Trabecular Fractal Dimension (P = .0044), and increasing Trabecular Separation (P = .0003) in MM mice. In cortical bone, irisin downregulates the expression of Sclerostin, a bone formation inhibitor, and RankL, a pro-osteoclastogenic molecule, while in BM it upregulates Opg, an anti-osteoclastogenic cytokine. We found that in the BM tibia of irisin-treated MM mice, the percentage of MM cells displays a reduction trend, while in the femur it decreases significantly. This is in line with the in vitro reduction of myeloma cell viability after 48 h of irisin stimulation at both 200 and 500 ng/mL and, after 72 h already at 100 ng/mL rec-irisin. These results could be due to irisin ability to downregulate the expression of Notch 3, which is important for cell-to-cell communication in the tumor niche, and Cyclin D1, supporting an inhibitory effect of irisin on MM cell proliferation. Overall, our findings suggest that irisin could be a new promising strategy to counteract MMBD and tumor burden in one shot.

Paracrine effects and heterogeneity of marrow-derived stem/progenitor cells: relevance for the treatment of respiratory diseases.

Stem cell-based treatment may represent a hope for the treatment of acute lung injury and pulmonary fibrosis, and other chronic lung diseases, such as cystic fibrosis, asthma and chronic obstructive pulmonary disease (COPD). It is well established in preclinical models that bone marrow-derived stem and progenitor cells exert beneficial effects on inflammation, immune responses and repairing of damage in virtually all lung-borne diseases. While it was initially thought that the positive outcome was due to a direct engraftment of these cells into the lung as endothelial and epithelial cells, paracrine factors are now considered the main mechanism through which stem and progenitor cells exert their therapeutic effect. This knowledge has led to the clinical use of marrow cells in pulmonary hypertension with endothelial progenitor cells (EPCs) and in COPD with mesenchymal stromal (stem) cells (MSCs). Bone marrow-derived stem cells, including hematopoietic stem/progenitor cells, MSCs, EPCs and fibrocytes, encompass a wide array of cell subsets with different capacities of engraftment and injured tissue-regenerating potential. The characterization/isolation of the stem cell subpopulations represents a major challenge to improve the efficacy of transplantation protocols used in regenerative medicine and applied to lung disorders.

Effect of acute lung injury on VLA-4 and CXCR4 expression in resident and circulating hematopoietic stem/progenitor cells.

BACKGROUND: The effect of acute lung injury on adhesion molecule expression in hematopoietic stem/progenitor cells (HSPCs) is poorly understood. OBJECTIVES: The aim of this study was to determine whether there is a relationship -between pulmonary inflammation, expression of VLA-4 (CD49d), LFA-1 (CD11a), L-selectin (CD62L), CXCR4, and chemotaxis in resident HSPCs, as well as the level of circulating HSPCs. METHODS: Following intratracheal administration of a single LPS bolus in C57Bl/6 mice, the number of inflammatory cells, differential counts, and amounts of cytokines/ chemokines were studied in cytospins and bronchoalveolar lavage fluid (BALF) specimens. Expressions of adhesion -molecules and CXCR4 were analyzed in HSPCs by flow cytometry, as well as SDF-1-directed chemotaxis. Levels of HSPCs in the blood were studied in ungated and circulating subpopulations. RESULTS: In coincidence with a peak of airway neutrophils, cytokine (IL-1ß, TNF-α, and IL-6), chemokine (KC, MIP-2, and SDF-1) levels in BALF and the number of marrow HSPCs expressing CD49d and CXCR4 significantly increased at 48 h. The number of CD49d- and CXCR4-positive HSPCs dropped at 72 h. The HSPC subset comprising bigger cells behaved the same for CD49d. Chemotaxis of the marrow HSPC subset of bigger cells was higher in LPS-treated animals than in controls at 72 h. Finally, we could detect a significant decrease in circulating Sca-1(+) cells in the mononuclear population at 72 h in LPS-treated mice. CONCLUSIONS: Our data provide evidence for a temporal relationship between pulmonary inflammation, CD49d and CXCR4 expression fluctuation in resident HSPCs, and the level of circulating HSPCs.

Lung Inflammatory Genes in Cystic Fibrosis and Their Relevance to Cystic Fibrosis Transmembrane Conductance Regulator Modulator Therapies.

Cystic fibrosis (CF) is a monogenic syndrome determined by over 2000 mutations in the CF Transmembrane Conductance Regulator (CFTR) gene harbored on chromosome 7. In people with CF (PWCF), lung disease is the major determinant of morbidity and mortality and is characterized by a clinical phenotype which differs in the presence of equal mutational assets, indicating that genetic and environmental modifiers play an important role in this variability. Airway inflammation determines the pathophysiology of CF lung disease (CFLD) both at its onset and progression. In this narrative review, we aim to depict the inflammatory process in CF lung, with a particular emphasis on those genetic polymorphisms that could modify the clinical outcome of the respiratory disease in PWCF. The natural history of CF has been changed since the introduction of CFTR modulator therapies in the clinical arena. However, also in this case, there is a patient-to-patient variable response. We provide an overview on inflammatory/immunity gene variants that affect CFLD severity and an appraisal of the effects of CFTR modulator therapies on the inflammatory process in lung disease and how this knowledge may advance the optimization of the management of PWCF.