Bone marrow-derived progenitors are greatly reduced in patients with severe COPD and low-BMI

Effects of Active Chronic Cigarette-Smoke Exposure on Circulating Fibrocytes

PURPOSE

This study aimed to evaluate the hypothesis that active smoking impacts upon mediators and abundance of circulating fibrocyte cells in smoking-related disease characterised by fibrosis.

METHODS

Flow cytometry and enzyme-linked immunosorbent assays were used to investigate blood from five patient groups: healthy never-smokers, healthy current smokers, stable chronic obstructive pulmonary disease (COPD) active smokers, idiopathic pulmonary fibrosis (IPF) never-smokers, and IPF active smokers.

RESULTS

A significant inverse dose-response relationship was observed in healthy smokers among cumulative smoking burden (pack-years) and fibrocyte abundance (p = 0.006, r = -0.86). Among serum profibrotic fibrocyte chemokines measured, CCL18 rose significantly alongside fibrocyte numbers in all five subject groups, while having an inverse dose-response relationship with pack-year burden in healthy smokers (p = 0.003, r = -0.89). In IPF, CCL2 rose in direct proportion to fibrocyte abundance irrespective of smoking status but had lower serum levels in those currently smoking (p =  < 0.001). For the study population, CXCL12 was decreased in pooled current smokers versus never-smokers (p = 0.03).

CONCLUSION

The suppressive effect of current, as distinct from former, chronic smoking on circulating fibrocyte abundance in healthy smokers, and modulation of regulatory chemokine levels by active smoking may have implications for future studies of fibrocytes in smoking-related lung diseases as a potential confounding variable.

p300/Sp1-Mediated High Expression of p16 Promotes Endothelial Progenitor Cell Senescence Leading to the Occurrence of Chronic Obstructive Pulmonary Disease

OBJECTIVE

Chronic obstructive pulmonary disease (COPD) is a common chronic disease and develops rapidly into a grave public health problem worldwide. However, what exactly causes the occurrence of COPD remains largely unclear. Here, we are trying to explore whether the high expression of p16 mediated by p300/Sp1 can cause chronic obstructive pulmonary disease through promoting the senescence of endothelial progenitor cells (EPCs).

METHODS

Peripheral blood EPCs were isolated from nonsmoking non-COPD, smoking non-COPD, and smoking COPD patients. The expressions of p16, p300, and senescence-related genes were detected by RT-PCR and Western Blot. Then, we knocked down or overexpressed Sp1 and p300 and used the ChIP assay to detect the histone H4 acetylation level in the promoter region of p16, CCK8 to detect cell proliferation, flow cytometry to detect the cell cycle, and β-galactosidase staining to count the proportion of senescent cells.

RESULTS

The high expression of p16 was found in peripheral blood EPCs of COPD patients; the cigarette smoke extract (CSE) led to the increase of p16. The high expression of p16 in EPCs promoted cell cycle arrest and apoptosis. The CSE-mediated high expression of p16 promoted cell senescence. The expression of p300 was increased in peripheral blood EPCs of COPD patients. Moreover, p300/Sp1 enhanced the histone H4 acetylation level in the promoter region of p16, thereby mediating the senescence of EPCs. And knockdown of p300/Sp1 could rescue CSE-mediated cell senescence.

CONCLUSION

p300/Sp1 enhanced the histone H4 acetylation level in the p16 promoter region to mediate the senescence of EPCs.

Mesenchymal Stromal Cells From Emphysematous Donors and Their Extracellular Vesicles Are Unable to Reverse Cardiorespiratory Dysfunction in Experimental Severe Emphysema

Although bone marrow-derived mesenchymal stromal cells (BM-MSCs) from patients with chronic obstructive pulmonary disease (COPD) appear to be phenotypically and functionally similar to BM-MSCs from healthy sources in vitro, the impact of COPD on MSC metabolism and mitochondrial function has not been evaluated. In this study, we aimed to comparatively characterize MSCs from healthy and emphysematous donors (H-MSCs and E-MSCs) in vitro and to assess the therapeutic potential of these MSCs and their extracellular vesicles (H-EVs and E-EVs) in an in vivo model of severe emphysema. For this purpose, C57BL/6 mice received intratracheal porcine pancreatic elastase once weekly for 4 weeks to induce emphysema; control animals received saline under the same protocol. Twenty-four hours after the last instillation, animals received saline, H-MSCs, E-MSCs, H-EVs, or E-EVs intravenously. In vitro characterization demonstrated that E-MSCs present downregulation of anti-inflammatory (TSG-6, VEGF, TGF-β, and HGF) and anti-oxidant (CAT, SOD, Nrf2, and GSH) genes, and their EVs had larger median diameter and lower average concentration. Compared with H-MSC, E-MSC mitochondria also exhibited a higher respiration rate, were morphologically elongated, expressed less dynamin-related protein-1, and produced more superoxide. When co-cultured with alveolar macrophages, both H-MSCs and E-MSCs induced an increase in iNOS and arginase-1 levels, but only H-MSCs and their EVs were able to enhance IL-10 levels. In vivo, emphysematous mice treated with E-MSCs or E-EVs demonstrated no amelioration in cardiorespiratory dysfunction. On the other hand, H-EVs, but not H-MSCs, were able to reduce the neutrophil count, the mean linear intercept, and IL-1β and TGF-β levels in lung tissue, as well as reduce pulmonary arterial hypertension and increase the right ventricular area in a murine model of elastase-induced severe emphysema. In conclusion, E-MSCs and E-EVs were unable to reverse cardiorespiratory dysfunction, whereas H-EVs administration was associated with a reduction in cardiovascular and respiratory damage in experimental severe emphysema.

Cigarette smoke extract affects methylation status and attenuates Sca-1 expression of mouse endothelial progenitor cell in vitro

INTRODUCTION

Endothelial dysfunction appears in many smoking-related diseases, it is also an important pathophysiological feature. Endothelial progenitor cells (EPCs) are precursors of endothelial cells and have a crucial effect on the repair and maintenance of endothelial integrity. Sca-1 is not only common in bone marrow-derived hematopoietic stem cells (HSCs), but it is also expressed in nonhematopoietic organs by tissue-resident stem and progenitor cells. The aim of this study is to investigate the impact of cigarette smoke extract (CSE) on the function of bone marrow-derived EPCs and the expression level of Sca-1 in EPCs, and also whether the methylation of Sca-1 is involved in EPC dysfunction.

METHODS

We measured EPC capacities including adhesion, secretion and proliferation, the concentration of endothelial nitric oxide synthase (eNOS) and apoptosis-inducing factor (AIF) in cell culture supernatant, and also Sca-1 expression and promoter methylation in EPCs induced by CSE. Decitabine (Dec) was applied to test whether it could alter the impact caused by CSE.

RESULTS

The adhesion, proliferation and secretion ability of EPCs can be induced to be decreased by CSE in vitro, accompanied by decreased concentrations of AIF and eNOS in cell culture supernatant and decreased Sca-1 expression in EPCs. In addition, Dec could partly attenuate the impact described above. There were no significant differences in the quantitative analysis of Sca-1 promoter methylation among different groups.

CONCLUSIONS

The decreased Sca-1 expression was related to EPC dysfunction induced by CSE. EPC dysfunction resulting from CSE may be related to methylation mechanism, but not the methylation of Sca-1 promoter.

The detrimental qualitative and quantitative alterations of circulating endothelial progenitor cells in patients with bronchiectasis

BACKGROUND

Bronchiectasis is an independent risk factor for cardiovascular disease（CVD）and cardiac dysfunction. Endothelial progenitor cells (EPCs) play a crucial role in maintaining endothelial function, and is inversely correlated with cardiovascular risk factors or cardiac dysfunction. However, the relationship between EPCs and bronchiectasis is unknown.

METHODS

Twenty-nine patients with stable bronchiectasis and 15 healthy controls were recruited. Fasting venous blood were collected for determining circulating EPC number and activity as well as systemic inflammatory cytokines.

RESULTS

The number and migratory or proliferative activity of circulating EPCs in bronchiectasis patients were significantly reduced (p < 0.001). In high E-FACED group, the number of circulating EPCs evaluated by cell culture assay and EPC proliferation were decreased (p < 0.05). Similarly, the number and function of circulating EPCs were both reduced in low forced expiratory volume in 1 s (FEV1) or high mMRC group (p < 0.05). There was a significant correlation between circulating EPCs and bronchiectasis disease severity, according to the E-FACED score (p < 0.05), particularly to FEV1 (p < 0.05) and mMRC dyspnea score (p < 0.05). The count and activity of EPCs inversely correlated with hsCRP levels and IL-6 levels (p < 0.01).

CONCLUSIONS

Deficiencies in the number and function of circulating EPCs are present in patients with bronchiectasis. The changes are related to disease severity and may be partly attributed to systemic inflammation. The current findings may provide novel surrogate evaluation biomarkers and potential therapeutic target for bronchiectasis.

The impact of periodontitis in the course of chronic obstructive pulmonary disease: Pulmonary and systemic effects

AIMS

The aim of this study was to verify the impact of periodontitis in the course of chronic obstructive pulmonary disease (COPD) in C57Bl/6J mice.

MAIN METHODS

The animals were randomly divided into four groups (n = 8): Basal, Periodontitis (P), COPD and COPD+P. COPD was induced by orotracheal instillation of 30 μl of cigarette extract 3 times/week for 7 weeks. Periodontitis was induced by ligation technique for 22 days. Euthanasia was performed on 51st day. The analyzes were total/differential cells and cytokines recovered from bronchoalveolar lavage (BAL), total/differential blood cell count, platelets, total marrow cell count, airway collagen deposition, alveolar enlargement analyzed by mean linear intercept (Lm), mucus and bone crest reabsorption. One-way ANOVA followed by the Student-Newman-Keuls was used.

KEY FINDINGS

The association COPD+P decreased macrophages (p = 0,0351), TNF-α (p = 0,0071) and INF-γ (p = 0,0004) in BAL, when compared to the COPD group maintaining emphysema levels by alveolar enlargement (p < .05) reorganization of collagen fibers (p = .001) and also mean linear intercept (lm) (p = .001) and mucus (p = .0001). The periodontitis group caused TNF-α increase (p = 0, 0001) in BAL.

SIGNIFICANCE

Periodontitis, per se, does not alter any of the parameters analyzed, except for increased TNF-α in BAL. However, its association with COPD caused macrophages TNF-α and INF-γ alterations, when compared to the COPD group maintaining emphysema levels by alveolar enlargement and reorganization of collagen fibers. It seems that periodontitis is influencing the course of Th1 profile cell, and cytokines and pulmonary alterations. Further studies are needed to clarify the regulatory process underlying these two diseases.

Association between tumor necrosis factor-α and chronic obstructive pulmonary disease: a systematic review and meta-analysis

Background:

Patients diagnosed with chronic obstructive pulmonary disease (COPD) have increased risks for a series of physical and mental illnesses. Tumor necrosis factor-α (TNF-α) has been reported to participate in the development of COPD and its complications. However, the values of blood TNF-α level used in the diagnosis of COPD remains controversial. In view of this, we performed a systematic review and meta-analysis to evaluate the correlation between TNF-α level and COPD.

Methods:

We searched PubMed, Web of Science, Embase and CNKI up to May 2018. The selection criteria were set according to the PICOS framework. A random-effects model was then applied to evaluate the overall effect sizes by calculating standard mean difference (SMD) and its 95% confidence intervals (CIs).

Results:

A total of 40 articles containing 4189 COPD patients and 1676 healthy controls were included in this meta-analysis. The results indicated a significant increase in TNF-α level in the COPD group compared with the control group (SMD: 1.24, 95% CI: 0.78–1.71, p < 0.00001). According to the subgroup analyses, we noted that TNF-α level was associated with predicted first second of forced expiration (FEV₁) (%) and study region. However, no association between TNF-α level and COPD was found when the participants were nonsmokers, and the mean age was less than 60 years.

Conclusions:

Our results indicated that TNF-α level was increased in COPD patients when compared with healthy controls. Illness progression and a diagnosis of COPD might contribute to higher TNF-α levels. However, the underlying mechanism still remains unknown and needs further investigation.

The reviews of this paper are available via the supplemental material section.

Vasculogenic Stem and Progenitor Cells in Human: Future Cell Therapy Product or Liquid Biopsy for Vascular Disease

New blood vessel formation in adults was considered to result exclusively from sprouting of preexisting endothelial cells, a process referred to angiogenesis. Vasculogenesis, the formation of new blood vessels from endothelial progenitor cells, was thought to occur only during embryonic life. Discovery of adult endothelial progenitor cells (EPCs) in 1997 opened the door for cell therapy in vascular disease. Endothelial progenitor cells contribute to vascular repair and are now well established as postnatal vasculogenic cells in humans. It is now admitted that endothelial colony-forming cells (ECFCs) are the vasculogenic subtype. ECFCs could be used as a cell therapy product and also as a liquid biopsy in several vascular diseases or as vector for gene therapy. However, despite a huge interest in these cells, their tissue and molecular origin is still unclear. We recently proposed that endothelial progenitor could come from very small embryonic-like stem cells (VSELs) isolated in human from CD133 positive cells. VSELs are small dormant stem cells related to migratory primordial germ cells. They have been described in bone marrow and other organs. This chapter discusses the reported findings from in vitro data and also preclinical studies that aimed to explore stem cells at the origin of vasculogenesis in human and then explore the potential use of ECFCs to promote newly formed vessels or serve as liquid biopsy to understand vascular pathophysiology and in particular pulmonary disease and haemostasis disorders.

Bone marrow characterization in COPD: a multi-level network analysis

Background

Bone marrow (BM) produces hematopoietic and progenitor cells that contribute to distant organ inflammation and repair. Chronic obstructive pulmonary disease (COPD) is characterized by defective lung repair. Yet, BM composition has not been previously characterized in COPD patients.

Methods

In this prospective and controlled study, BM was obtained by sternum fine-needle aspiration in 35 COPD patients and 25 healthy controls (10 smokers and 15 never-smokers). BM cell count and immunophenotype were determined by microscopy and flow cytometry, respectively. Circulating inflammatory (C-reactive protein, IL-6, IL-8) and repair markers (HGF, IGF, TGF-β, VEGF) were quantified by ELISA. Results were integrated by multi-level network correlation analysis.

Results

We found that: (1) there were no major significant pair wise differences between COPD patients and controls in the BM structural characteristics; (2) multi-level network analysis including patients and controls identifies a relation between immunity, repair and lung function not previously described, that remains in the COPD network but is absent in controls; and (3) this novel network identifies eosinophils as a potential mediator relating immunity and repair, particularly in patients with emphysema.

Conclusions

Overall, these results suggest that BM is activated in COPD with impaired repair capacity in patients with more emphysema and/or higher circulating eosinophils.

Electronic supplementary material

The online version of this article (10.1186/s12931-018-0824-x) contains supplementary material, which is available to authorized users.

Imbalance between endothelial damage and repair capacity in chronic obstructive pulmonary disease

Background

Circulating endothelial microparticles (EMPs) and progenitor cells (PCs) are biological markers of endothelial function and endogenous repair capacity. The study was aimed to investigate whether COPD patients have an imbalance between EMPs to PCs compared to controls and to evaluate the effect of cigarette smoke on these circulating markers.

Methods

Circulating EMPs and PCs were determined by flow cytometry in 27 nonsmokers, 20 smokers and 61 COPD patients with moderate to severe airflow obstruction. We compared total EMPs (CD31⁺CD42b^-), apoptotic if they co-expressed Annexin-V⁺ or activated if they co-expressed CD62E⁺, circulating PCs (CD34⁺CD133⁺CD45⁺) and the EMPs/PCs ratio between groups.

Results

COPD patients presented increased levels of total and apoptotic circulating EMPs, and an increased EMPs/PCs ratio, compared with nonsmokers. Women had less circulating PCs than men through all groups and those with COPD showed lower levels of PCs than both control groups. In smokers, circulating EMPs and PCs did not differ from nonsmokers, being the EMPs/PCs ratio in an intermediate position between COPD and nonsmokers.

Conclusions

We conclude that COPD patients present an imbalance between endothelial damage and repair capacity that might explain the frequent concurrence of cardiovascular disorders. Factors related to the disease itself and gender, rather than cigarette smoking, may account for this imbalance.

Very Small Embryonic-like Stem Cells Are Mobilized in Human Peripheral Blood during Hypoxemic COPD Exacerbations and Pulmonary Hypertension

Very small embryonic-like stem cells (VSELs) are major pluripotent stem cells involved in vascular and tissue regeneration and constitute a recruitable pool of stem/progenitor cells with putative instrumental role in organ repair. Here, we hypothesized that VSELs might be mobilized from the bone marrow (BM) to peripheral blood (PB) in patients with hypoxic lung disease or pulmonary hypertension (PH). The objective of the present study was then to investigate the changes in VSELs number in peripheral blood of patients with hypoxic lung disease and PH. We enrolled 26 patients with Chronic Obstructive Pulmonary Disease (COPD) with or without hypoxemia, 13 patients with PH and 20 controls without any respiratory or cardiovascular diseases. In PH patients, VSELs levels have been determined during right heart catheterization in pulmonary blood and PB. For this purpose, mononuclear cells were separated by density gradient and VSELs have been quantified by using a multiparametric flow cytometry approach. The number of PB-VSELs in hypoxic COPD patients was significantly increased compared with non-hypoxic COPD patients or controls (p = 0.0055). In patients with PH, we did not find any difference in VSELs numbers between arterial pulmonary blood and venous PB (p = 0.93). However, we found an increase in VSELs in the peripheral blood of patients with PH (p = 0.03). In conclusion, we unraveled that circulating VSELs were increased in peripheral blood of patients with hypoxic COPD or with PH. Thus, VSELs may serve as a reservoir of pluripotent stem cells that can be recruited into PB and may play an important role in promoting lung repair.

Pulmonary vascular endothelium: the orchestra conductor in respiratory diseases

The European Respiratory Society (ERS) Research Seminar entitled “Pulmonary vascular endothelium: orchestra conductor in respiratory diseases - highlights from basic research to therapy” brought together international experts in dysfunctional pulmonary endothelium, from basic science to translational medicine, to discuss several important aspects in acute and chronic lung diseases. This review will briefly sum up the different topics of discussion from this meeting which was held in Paris, France on October 27–28, 2016. It is important to consider that this paper does not address all aspects of endothelial dysfunction but focuses on specific themes such as: 1) the complex role of the pulmonary endothelium in orchestrating the host response in both health and disease (acute lung injury, chronic obstructive pulmonary disease, high-altitude pulmonary oedema and pulmonary hypertension); and 2) the potential value of dysfunctional pulmonary endothelium as a target for innovative therapies.

Hypoxia induces the dysfunction of human endothelial colony-forming cells via HIF-1α signaling

Endothelial injury is considered as a trigger of pulmonary vascular lesions in the pathogenesis of hypoxic pulmonary hypertension (HPH). Although endothelial colony-forming cells (ECFCs) have vascular regeneration potential to maintain endothelial integrity, hypoxia-induced precise alteration in ECFCs function remains controversial. This study investigated the impact of hypoxia on human ECFCs function in vitro and the underlying mechanism. We found that hypoxia inhibited ECFCs proliferation, migration and angiogenesis. Compared with no treatment, the expression of hypoxia inducible factor-1α (HIF-1α) in hypoxia-treated ECFCs was increased, with an up-regulation of p27 and a down-regulation of cyclin D1. The over-secreted vascular endothelial growth factor (VEGF) was detected, with the imbalanced expression of fetal liver kinase 1 (flk-1) and fms related tyrosine kinase 1 (flt-1). Hypoxia-induced changes in ECFCs could be reversed by HIF-1α inhibitor KC7F2. These data suggest that HIF-1α holds the key in regulating ECFCs function which may open a new perspective of ECFCs in HPH management.

Predictors of Mononuclear Cell Yield in Patients Undergoing Autologous Mononuclear Stem Cell Therapy in Non-haemopoietic Degenerative Disorders

Cellular therapy outcomes are influenced by cellular composition of the product. We analyzed the cellular profiles (TNC, MNC and CD34+ cells) of patients receiving mononuclear cell therapy in terms of age, gender, BMI, pre-harvest haematological counts and clinical conditions. Cellular profiles of 262 patients were analyzed in terms of age (age < 40 year, age 41-60 year and age > 60 year), gender, BMI (BMI < 22 kg/m², BMI 22-25 kg/m² and BMI > 25 kg/m²), pre-harvest haematological profile and clinical conditions (chronic disorders, group A, acute vascular group B and traumatic events, group C). A steady decline was observed in TNC and MNC counts with increasing age and BMI. In clinical conditions, group C showed a highest cellular yield followed by group A and group B respectively. Amongst the three age groups, group I (age < 40 year) showed a better cellular profiles than group II (age 41-60 year) and group III (age > 60 year). Patients with Higher TLC (>7000/μl) and platelet count (>200 × 10³/μl) yielded better cellular profile in the harvest. Patient age, BMI, haematological counts and clinical condition significantly affect the bone marrow cellular profile.

Concise Review: The Deleterious Effects of Cigarette Smoking and Nicotine Usage and Mesenchymal Stem Cell Function and Implications for Cell-Based Therapies

Stem cell sources for cell‐based therapeutics are often screened for infectious agents and genetic diseases prior to implantation; however, there are other risk factors that are often overlooked, which may ultimately lead to less efficacious clinical outcomes. One such risk factor is exposure of mesenchymal stem cells (MSCs) to cigarette smoke or nicotine. Recent data have shown that exposure to cigarette smoke or nicotine leads to decreased regenerative potential, namely decreased proliferation, decreased migration, and decreased differentiation potential of exposed MSCs. This review provides a brief introduction into MSCs and their respective niches and a summary regarding the interactions of cigarettes and nicotine with MSCs populations. Specifically, the effects of cigarette smoke and nicotine on the regenerative potential of MSCs (i.e., proliferation, migration, and differentiation) will be covered with an emphasis on considerations for the development of future cell‐based clinical trials and therapies. stemcellstranslationalmedicine2017;6:1815–1821

Endothelial progenitor cells in chronic obstructive pulmonary disease and emphysema

Endothelial injury is implicated in the pathogenesis of COPD and emphysema; however the role of endothelial progenitor cells (EPCs), a marker of endothelial cell repair, and circulating endothelial cells (CECs), a marker of endothelial cell injury, in COPD and its subphenotypes is unresolved. We hypothesized that endothelial progenitor cell populations would be decreased in COPD and emphysema and that circulating endothelial cells would be increased. Associations with other subphenotypes were examined. The Multi-Ethnic Study of Atherosclerosis COPD Study recruited smokers with COPD and controls age 50–79 years without clinical cardiovascular disease. Endothelial progenitor cell populations (CD34+KDR+ and CD34+KDR+CD133+ cells) and circulating endothelial cells (CD45dimCD31+CD146+CD133-) were measured by flow cytometry. COPD was defined by standard spirometric criteria. Emphysema was assessed qualitatively and quantitatively on CT. Full pulmonary function testing and expiratory CTs were measured in a subset. Among 257 participants, both endothelial progenitor cell populations, and particularly CD34+KDR+ endothelial progenitor cells, were reduced in COPD. The CD34+KDR+CD133+ endothelial progenitor cells were associated inversely with emphysema extent. Both endothelial progenitor cell populations were associated inversely with extent of panlobular emphysema and positively with diffusing capacity. Circulating endothelial cells were not significantly altered in COPD but were inversely associated with pulmonary microvascular blood flow on MRI. There was no consistent association of endothelial progenitor cells or circulating endothelial cells with measures of gas trapping. These data provide evidence that endothelial repair is impaired in COPD and suggest that this pathological process is specific to emphysema.

Mesenchymal Stem Cell Administration in Patients with Chronic Obstructive Pulmonary Disease: State of the Science

Patients with chronic obstructive pulmonary disease (COPD) have chronic, irreversible airway inflammation; currently, there is no effective or curative treatment and the main goals of COPD management are to mitigate symptoms and improve patients' quality of life. Stem cell based therapy offers a promising therapeutic approach that has shown potential in diverse degenerative lung diseases. Preclinical studies have demonstrated encouraging outcomes of mesenchymal stem/stromal cells (MSCs) therapy for lung disorders including emphysema, bronchopulmonary dysplasia, fibrosis, and acute respiratory distress syndrome. This review summarizes available data on 15 studies currently registered by the ClinicalTrials.gov repository, which used different stem cell therapy protocols for COPD; these included bone marrow mononuclear cells (BMMCs), bone marrow-derived MSCs, adipose-derived stem/stromal cells (ADSCs), and adipose-derived MSCs. Published results of three trials indicate that administering BMMCs or MSCs in the setting of degenerative lung disease is safe and may improve patients' condition and quality of life; however, larger-scale studies are needed to evaluate efficacy. Results of another completed trial (NCT01872624) are not yet published, and eleven other studies are ongoing; these include MSCs therapy in emphysema, several studies of ADSCs in COPD, another in idiopathic pulmonary fibrosis, and plerixafor mobilization of CD117 stem cells to peripheral blood.

Stem Cells and Lung Regeneration

Background:Tissues such as the lung, liver, and pancreas that have a low steady-state cell turnover yet can respond robustly after injury to replace damaged cells. The airway epithelium is exposed to inhaled particles and pathogens that may lead to the development of a many infectious and inflammatory respiratory diseases. Lung transplantation is an accepted modality of treatment for end-stage lung diseases. Since the early 1990 s, more than 26,000 lung transplants have been performed at centers worldwide. However, the availability of donor tissues and organs is limited, which presents a serious limitation for widespread transplantation surgery. The appearance of bioengineered lung and tracheal tissue transplants is considered a promising alternative to the classical transplantation of donor organ/tissue. Stem cells therapy arises as a new therapeutic approach, with a wide application potential.

Association between serum interleukin-6 concentrations and chronic obstructive pulmonary disease: a systematic review and meta-analysis

Background. Interleukin-6 (IL-6) is an important pro-inflammatory cytokine and has been implicated to play a role in the systemic inflammation of patients with chronic obstructive pulmonary disease (COPD). We conducted this meta-analysis to assess the association between serum IL-6 concentrations and COPD.

Methods. PubMed and Embase were searched for eligible studies. Data were extracted by two investigators (Wei J, Xiong XF) independently and analyzed using Review Manager 5.3 and STATA 12.0 software. Standard mean differences (SMDs) and 95% confidence intervals (CI) were calculated.

Results. Thirty-three studies were included in this meta-analysis. The serum IL-6 concentrations were higher in patients with stable COPD than healthy controls (SMD = 0.65, 95% CI [0.51–0.79]). COPD patients without major comorbidities also showed higher IL-6 levels than healthy controls (SMD = 0.74, 95% CI [0.56–0.91]). COPD patients with an forced expiratory volume in one second (FEV₁) of either <50% predicted or >50% predicted had increased IL-6 concentrations compared to healthy controls (SMD = 0.77, 95% CI [0.48–1.05], SMD = 1.01, 95% CI [0.43–1.59], respectively). The serum IL-6 concentrations between mild-moderate and severe-very severe COPD patient groups were not found to be significant (SMD = −0.1, 95% CI [−0.65–0.44]).

Conclusions. This meta-analysis indicated that patients with stable COPD had higher serum IL-6 concentrations than healthy controls. No evidence showing positive or negative association between IL-6 concentrations and the severity of pulmonary function impairment was found. The correlation between IL-6 levels and pulmonary function was weak in different severities of stable COPD patients.

B cells modulate systemic responses to Pneumocystis murina lung infection and protect on-demand hematopoiesis via T cell-independent innate mechanisms when type I interferon signaling is absent

HIV infection results in a complex immunodeficiency due to loss of CD4(+) T cells, impaired type I interferon (IFN) responses, and B cell dysfunctions causing susceptibility to opportunistic infections such as Pneumocystis murina pneumonia and unexplained comorbidities, including bone marrow dysfunctions. Type I IFNs and B cells critically contribute to immunity to Pneumocystis lung infection. We recently also identified B cells as supporters of on-demand hematopoiesis following Pneumocystis infection that would otherwise be hampered due to systemic immune effects initiated in the context of a defective type I IFN system. While studying the role of type I IFNs in immunity to Pneumocystis infection, we discovered that mice lacking both lymphocytes and type I IFN receptor (IFrag(-/-)) developed progressive bone marrow failure following infection, while lymphocyte-competent type I IFN receptor-deficient mice (IFNAR(-/-)) showed transient bone marrow depression and extramedullary hematopoiesis. Lymphocyte reconstitution of lymphocyte-deficient IFrag(-/-) mice pointed to B cells as a key player in bone marrow protection. Here we define how B cells protect on-demand hematopoiesis following Pneumocystis lung infection in our model. We demonstrate that adoptive transfer of B cells into IFrag(-/-) mice protects early hematopoietic progenitor activity during systemic responses to Pneumocystis infection, thus promoting replenishment of depleted bone marrow cells. This activity is independent of CD4(+) T cell help and B cell receptor specificity and does not require B cell migration to bone marrow. Furthermore, we show that B cells protect on-demand hematopoiesis in part by induction of interleukin-10 (IL-10)- and IL-27-mediated mechanisms. Thus, our data demonstrate an important immune modulatory role of B cells during Pneumocystis lung infection that complement the modulatory role of type I IFNs to prevent systemic complications.

Biology and flow cytometry of proangiogenic hematopoietic progenitors cells

During development, hematopoiesis and neovascularization are closely linked to each other via a common bipotent stem cell called the hemangioblast that gives rise to both hematopoietic cells and endothelial cells. In postnatal life, this functional connection between the vasculature and hematopoiesis is maintained by a subset of hematopoietic progenitor cells endowed with the capacity to differentiate into potent proangiogenic cells. These proangiogenic hematopoietic progenitors comprise a specific subset of bone marrow (BM)-derived cells that homes to sites of neovascularization and possess potent paracrine angiogenic activity. There is emerging evidence that this subpopulation of hematopoietic progenitors plays a critical role in vascular health and disease. Their angiogenic activity is distinct from putative "endothelial progenitor cells" that become structural cells of the endothelium by differentiation into endothelial cells. Proangiogenic hematopoietic progenitor cell research requires multidisciplinary expertise in flow cytometry, hematology, and vascular biology. This review provides a comprehensive overview of proangiogenic hematopoietic progenitor cell biology and flow cytometric methods to detect these cells in the peripheral blood circulation and BM.

Circulating progenitor cells and vascular dysfunction in chronic obstructive pulmonary disease

Background

In chronic obstructive pulmonary disease (COPD), decreased progenitor cells and impairment of systemic vascular function have been suggested to confer higher cardiovascular risk. The origin of these changes and their relationship with alterations in the pulmonary circulation are unknown.

Objectives

To investigate whether changes in the number of circulating hematopoietic progenitor cells are associated with pulmonary hypertension or changes in endothelial function.

Methods

62 COPD patients and 35 controls (18 non-smokers and 17 smokers) without cardiovascular risk factors other than cigarette smoking were studied. The number of circulating progenitors was measured as CD45⁺CD34⁺CD133⁺ labeled cells by flow cytometry. Endothelial function was assessed by flow-mediated dilation. Markers of inflammation and angiogenesis were also measured in all subjects.

Results

Compared with controls, the number of circulating progenitor cells was reduced in COPD patients. Progenitor cells did not differ between control smokers and non-smokers. COPD patients with pulmonary hypertension showed greater number of progenitor cells than those without pulmonary hypertension. Systemic endothelial function was worse in both control smokers and COPD patients. Interleukin-6, fibrinogen, high sensitivity C-reactive protein, vascular endothelial growth factor and tumor necrosis factor were increased in COPD. In COPD patients, the number of circulating progenitor cells was inversely related to the flow-mediated dilation of systemic arteries.

Conclusions

Pulmonary and systemic vascular impairment in COPD is associated with cigarette smoking but not with the reduced number of circulating hematopoietic progenitors. The latter appears to be a consequence of the disease itself not related to smoking habit.

Vascular responsiveness in patients with Chronic Obstructive Pulmonary Disease (COPD)

BACKGROUND

Ischemic heart disease and peripheral vascular diseases are prevalent in COPD and it is estimated that any 10% decrease in forced expiratory volume in 1 second (FEV1) is associated with 30% increased cardiovascular risk of death. Endothelial dysfunction may be one of the mechanistic pathways that link between COPD and cardiovascular mortality. Our aim was to study the vascular reactivity of patients with stable COPD and to try to correlate endothelial dysfunction, vascular reactivity and functional capacity of these patients that eventually may lead to cardiovascular mortality.

METHODS

This was a prospective study. Twenty-three consecutive ambulatory COPD patients were enrolled. All were smoking men, aged 64.4 ± 8.4 years. Twenty-two healthy volunteers aged 44.7 ± 11.7 years, BMI of 25.2 ± 4.2, height of 172 ± 8 cm served as the control group. Vascular studies included endothelial function and ankle brachial index.

RESULTS

Baseline diameter of the brachial artery was larger in COPD patients compared with controls. The absolute change in diameter post hyperemia was significantly less in patients (0.004 ± 0.02 cm vs. 0.05 ± 0.02 cm, p<0.001) and COPD patients responded to hyperemia by constriction instead of dilatation (FMD% was -0.6 ± 6.3% in patients vs. 15.6 ± 7.6% in controls, p<0.001). There was no difference in ABI in patients and controls (0.95 ± 0.26 vs. 1.06 ± 0.16, p=0.07).

DISCUSSION

We found that patients with COPD have dilated arteries, have impaired ability to respond to high shear stress that triggers nitric oxide dependent flow mediated dilatation, and have also impaired ability to function - represented by the poor 6 minute walk test.

Decreased CD34+ cell number is correlated with cardiac dysfunction in patients with acute exacerbation of COPD

BACKGROUND AND PURPOSE

Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is associated with a higher risk of cardiovascular disease (CVD). Previous studies have indicated that the reduction of bone marrow-derived multipotent progenitors (CD34+ cells) may lead to reduced vascular repair capacity and may help to identify patients that pose an increased cardiovascular risk. However, the relationship between CD34+cells and CVD risk in AECOPD remains unclear. The aim of the present study was to assess CD34+ cell counts and their relationship with classical adverse cardiac outcome predictors in AECOPD.

METHODS

For our study, 27 patients with AECOPD (GOLD stage III, IV), 26 with stable COPD (GOLD stage III, IV), and 24 healthy controls were enrolled. CD34+ cells were enumerated, and plasma concentrations of N-terminal pro-B-type natriuretic peptide (NT-proBNP), a systemic inflammation marker (high-sensitivity C-reactive protein, hsCRP) and mobilisation marker (matrix metalloproteinase-9, MMP-9), were measured. Echocardiography was performed to evaluate cardiac dysfunction and pulmonary hypertension.

RESULTS

Compared with healthy controls, AECOPD patients had a significantly decreased CD34+ cell count (5.1 ± 2.6 versus 9.4 ± 3.6 × 10³/ml), especially in patients with a prior history of acute exacerbation. For patients with AECOPD, the CD34+ cell count was inversely correlated with NT-proBNP levels, pulmonary artery systolic pressure (PASP) and resting heart rate, and positively correlated with left ventricular ejection fraction (LVEF). In all three groups, CD34+ cell count was negatively correlated with hsCRP.

CONCLUSIONS

The circulating CD34+ cell count was decreased and correlated with cardiac dysfunction in AECOPD patients, and thus may account for the increased cardiovascular risk in this population.

Cigarette Smoke Alters the Hematopoietic Stem Cell Niche

Effects of tobacco smoke on hematologic derangements have received little attention. This study employed a mouse model of cigarette smoke exposure to explore the effects on bone marrow niche function. While lung cancer is the most widely studied consequence of tobacco smoke exposure, other malignancies, including leukemia, are associated with tobacco smoke exposure. Animals received cigarette smoke exposure for 6 h/day, 5 days/week for 9 months. Results reveal that the hematopoietic stem and progenitor cell (HSPC) pool size is reduced by cigarette smoke exposure. We next examined the effect of cigarette smoke exposure on one supporting cell type of the niche, the mesenchymal stromal cells (MSCs). Smoke exposure decreased the number of MSCs. Transplantation of naïve HSPCs into irradiated mice with cigarette smoke exposure yielded fewer numbers of engrafted HSPCs. This result suggests that smoke-exposed mice possess dysfunctional niches, resulting in abnormal hematopoiesis. Co-culture experiments using MSCs isolated from control or cigarette smoke-exposed mice with naïve HSPCs in vitro showed that MSCs from cigarette smoke-exposed mice generated marked expansion of naïve HSPCs. These data show that cigarette smoke exposure decreases in vivo MSC and HSC number and also increases pro-proliferative gene expression by cigarette smoke-exposed MSCs, which may stimulate HSPC expansion. These results of this investigation are clinically relevant to both bone marrow donors with a history of smoking and bone marrow transplant (BMT) recipients with a history of smoking.

Dual effects of cigarette smoke extract on proliferation of endothelial progenitor cells and the protective effect of 5-aza-2'-deoxycytidine on EPCs against the damage caused by CSE

Cigarette smoke is a major public health problem associated with multitude of diseases, including pulmonary and vascular diseases. Endothelial progenitor cells (EPCs) contribute to neovascularization and play an important role in the development of these diseases. The effect of CSE on EPCs is seldom studied. The aim of the current study is to observe the effect of CSE on biological behavior of EPCs and, further, to search for potential candidate agent in protection of proliferation of EPCs against the damage caused by CSE exposure in vitro. Methods. The proliferations of EPCs isolated from bone marrow of C57BL/6J mice were assessed by MTT after incubating the EPCs with a series of concentrations of CSE (1.0%, 2.5%, 5.0%, and 10.0%) for different times (3, 6, and 24 hours) as well as with 1.0% CSE in presence of 5-AZA-CdR for 24 hours. Results. The proliferations of EPCs were significantly enhanced after 3 hours of exposure to concentrations of 1.0% and 2.5% CSE but depressed when exposed to concentrations of 5.0% and 10.0% CSE. Furthermore, the 5-AZA-CdR in concentrations of 2.0 μmol/L and 5.0 μmol/L partly protected against the depression of proliferation of EPCs caused by CSE exposure. Conclusions. The CSE showed dual effects on proliferation of EPCs isolated from mice. The 5-AZA-CdR partly protected the proliferation of EPCs against the damage caused by CSE exposure in vitro, suggesting that DNA methylation may be involved in the dysfunction of EPCs induced by CSE.

Circulating hematopoietic progenitor cells are decreased in COPD

RATIONALE

Bone marrow derived progenitor cells participate in the repair of injured vessels. The lungs of individuals with emphysema have reduced alveolar capillary density and increased endothelial apoptosis. We hypothesized that circulating levels of endothelial and hematopoietic progenitor cells would be reduced in this group of patients.

OBJECTIVES

The goal of this study was to measure circulating levels of endothelial progenitor cells (EPCs) and hematopoietic progenitor cells (HPCs) in subjects with COPD and to determine if progenitor levels correlated with disease severity and the presence of emphysema.

METHODS

Peripheral blood mononuclear cells were isolated from 61 patients with COPD and 32 control subjects. Levels of EPCs (CD45(dim) CD34+) and HPCs (CD45(+) CD34(+) VEGF-R2(+)) were quantified using multi-parameter flow cytometry. Progenitor cell function was assessed using cell culture assays. All subjects were evaluated with spirometry and CT scanning.

MEASUREMENTS AND MAIN RESULTS

HPC levels were reduced in subjects with COPD compared to controls, whereas circulating EPC levels were similar between the two groups. HPC levels correlated with severity of obstruction and were lowest in subjects with severe emphysema. These associations remained after correction for factors known to affect progenitor cell levels including age, smoking status, the use of statin medications and the presence of coronary artery disease. The ability of mononuclear cells to form endothelial cell colony forming units (EC-CFU) was also reduced in subjects with COPD.

CONCLUSIONS

HPC levels are reduced in subjects with COPD and correlate with emphysema phenotype and severity of obstruction. Reduction of HPCs may disrupt maintenance of the capillary endothelium, thereby contributing to the pathogenesis of COPD.

C-Kit/c-Kit ligand interaction of bone marrow endothelial progenitor cells is influenced in a cigarette smoke extract-induced emphysema model

BACKGROUND

Smoking causes lung endothelial cell apoptosis and emphysema. Derived from bone marrow, circulating endothelial progenitor cells (EPCs) maintain vascular integrity by replacing and repairing damaged endothelial cells. Smoking influences the number of circulating EPCs. Recruitment of EPCs from bone marrow to peripheral blood depends on the interaction of c-Kit/soluble c-Kit ligand (sKitL). We hypothesized that smoking might influence c-Kit(+) EPCs/sKitL interaction in bone marrow in the development of smoking-related emphysema. In this study, we used a cigarette smoke extract (CSE)-induced emphysema model.

METHODS

Mice were injected intraperitoneally with PBS/CSE and sacrificed at day 28. Lung function and pathology of lung tissue were measured to characterize the model. Expressions of c-Kit in the lung tissue were assayed. Bone marrow cells were isolated by red blood cell lysis. EPCs/c-Kit(+) EPCs in nonred blood cells were analyzed by flow cytometry. Expressions of KitL and MMP-9, and activity MMP-9 in bone marrow were measured.

RESULTS

Our data demonstrated that gene and protein expressions of c-Kit were decreased in the lung tissue in this model. Compared with the control group, the number of bone marrow nonred blood cells was unchanged following CSE treatment, while the depletion of bone marrow EPCs/c-Kit(+) EPCs was significant. The level of sKitL was reduced in the bone marrow in the model. The reduction of sKitL was associated with deregulated KitL expression and decreased MMP-9 activity.

CONCLUSIONS

The interaction between c-Kit and sKitL in bone marrow EPCs, a critical step in endothelial repair, is negatively affected in a CSE-induced emphysema model.

Mobilization of endothelial progenitor cells from bone marrow is impaired in a piglet model of acute respiratory distress syndrome

OBJECTIVES

To characterize the endothelial progenitor cell mobilization in the models of moderate and severe lung injury, we hypothesized that there were differences in endothelial progenitor cell levels and mobilizing cytokines between moderate and severe lung injury.

DESIGN

Prospective, randomized, and controlled experimental study.

SETTING

University research laboratory center.

SUBJECTS

Fifteen healthy piglets.

INTERVENTIONS

Piglets were randomly allocated to control, moderate lung injury (acute lung injury), and severe lung injury (acute respiratory distress syndrome) groups. Lung injury was established by intravenous infusion of oleic acid. Animals were mechanically ventilated for 24-48 hours, and then animals were weaned from ventilation and cared for until day 7.

MEASUREMENTS AND MAIN RESULTS

Endothelial progenitor cells were quantified by flow cytometry. After 24 hours, the number of endothelial progenitor cells in peripheral blood increased in the acute lung injury group but was not altered in the acute respiratory distress syndrome group compared to the control group. The number of CD34KDR, KDRCD133, and CD34KDRCD133 cells was higher in the acute lung injury group than in the acute respiratory distress syndrome group. In bone marrow, the number of CD34KDR and KDRCD133 cells was greater in acute respiratory distress syndrome animals but not altered in acute lung injury animals at 24 hours. Furthermore, plasma stromal cell-derived factor-1 and vascular endothelial growth factor concentrations were higher in acute lung injury than in acute respiratory distress syndrome at 24 hours. Matrix metalloproteinase-9 and soluble kit ligand levels in bone marrow were reduced in acute respiratory distress syndrome compared with acute lung injury. Lung CD34, KDR, and lung stromal cell-derived factor-1 messenger RNA expression were higher in the acute lung injury group than in the acute respiratory distress syndrome group. Furthermore, the expression of CD34, KDR, and CD133 messenger RNA in lung tissue was correlated with stromal cell-derived factor-1 in the lung.

CONCLUSIONS

There was a rapid release of endothelial progenitor cells from bone marrow into circulation in moderate acute lung injury, and endothelial progenitor cell mobilization was impaired in acute respiratory distress syndrome.

Stem cell treatment for chronic lung diseases

Chronic lung diseases such as idiopathic pulmonary fibrosis and cystic fibrosis or chronic obstructive pulmonary disease and asthma are leading causes of morbidity and mortality worldwide with a considerable human, societal and financial burden. In view of the current disappointing status of available pharmaceutical agents, there is an urgent need for alternative more effective therapeutic approaches that will not only help to relieve patient symptoms but will also affect the natural course of the respective disease. Regenerative medicine represents a promising option with several fruitful therapeutic applications in patients suffering from chronic lung diseases. Nevertheless, despite relative enthusiasm arising from experimental data, application of stem cell therapy in the clinical setting has been severely hampered by several safety concerns arising from the major lack of knowledge on the fate of exogenously administered stem cells within chronically injured lung as well as the mechanisms regulating the activation of resident progenitor cells. On the other hand, salient data arising from few 'brave' pilot investigations of the safety of stem cell treatment in chronic lung diseases seem promising. The main scope of this review article is to summarize the current state of knowledge regarding the application status of stem cell treatment in chronic lung diseases, address important safety and efficacy issues and present future challenges and perspectives. In this review, we argue in favor of large multicenter clinical trials setting realistic goals to assess treatment efficacy. We propose the use of biomarkers that reflect clinically inconspicuous alterations of the disease molecular phenotype before rigid conclusions can be safely drawn.

Circulating endothelial progenitor cells inversely associate with organ dysfunction in sepsis

PURPOSE

Endothelial dysfunction is a primary contributor to sepsis-related organ dysfunction and death. In sepsis animal models, endothelial progenitor cells (EPC) have contributed to vascular repair. The role of endothelial progenitor cells as a biomarker for organ dysfunction is still unknown. We hypothesized that circulating numbers of endothelial progenitor cells would be associated with improved outcomes in sepsis.

METHODS

Prospective, observational single-center cohort study in adult intensive care units at Grady Memorial Hospital, an affiliate of Emory University, from July 2007 through April 2009. Peripheral blood was obtained from 95 patients with sepsis, 37 intensive care unit controls, and 51 healthy controls, of whom only 86 patients with sepsis were used in the analysis because we were not able to obtain enough blood in 9 sepsis patients. Clinical data were obtained, and organ dysfunction was measured by Sepsis-Related Organ Failure Assessment (SOFA) score. Endothelial progenitor cells were assessed by a colony-forming unit (CFU) assay in which peripheral blood mononuclear cells were isolated using Ficoll density-gradient centrifugation and cultured in growth media.

RESULTS

The patients with sepsis had significantly lower mean endothelial progenitor cell colony counts compared with intensive care unit controls (p = 0.035) and healthy controls (p = 0.0005). There was no difference in colony counts between ICU controls and healthy controls (p = 0.81). In the sepsis patients, EPC CFU numbers inversely associated with SOFA score, adjusting for mortality (r (2) = 0.05, p = 0.04).

CONCLUSION

Increased circulating endothelial progenitor cells inversely correlate with organ dysfunction in sepsis patients.

Protective effects of bone marrow mononuclear cell therapy on lung and heart in an elastase-induced emphysema model

We hypothesized that bone marrow-derived mononuclear cell (BMDMC) therapy protects the lung and consequently the heart in experimental elastase-induced emphysema. Twenty-four female C57BL/6 mice were intratracheally instilled with saline (C group) or porcine pancreatic elastase (E group) once a week during 4 weeks. C and E groups were randomized into subgroups receiving saline (SAL) or male BMDMCs (2 × 10(6), CELL) intravenously 3h after the first saline or elastase instillation. Compared to E-SAL group, E-CELL mice showed, at 5 weeks: lower mean linear intercept, neutrophil infiltration, elastolysis, collagen fiber deposition in alveolar septa and pulmonary vessel wall, lung cell apoptosis, right ventricle wall thickness and area, higher endothelial growth factor and insulin-like growth factor mRNA expressions in lung tissue, and reduced platelet-derived growth factor, transforming growth factor-β, and caspase-3 expressions. In conclusion, BMDMC therapy was effective at modulating the inflammatory and remodeling processes in the present model of elastase-induced emphysema.

Bone marrow cells repair cigarette smoke-induced emphysema in rats

The therapeutic potential of stem cells in chronic obstructive pulmonary disease is not well known although stem cell therapy is effective in models of other pulmonary diseases. We tested the capacities of bone marrow cells (BMCs), mesenchymal stem cells (MSCs), and conditioned media of MSCs (MSC-CM) to repair cigarette smoke-induced emphysema. Inbred female Lewis rats were exposed to cigarette smoke for 6 mo and then received BMCs, MSCs, or MSC-CM from male Lewis rats. For 2 mo after injection, the BMC treatment gradually alleviated the cigarette smoke-induced emphysema and restored the increased mean linear intercept. The BMC treatment significantly increased cell proliferation and the number of small pulmonary vessels, reduced apoptotic cell death, attenuated the mean pulmonary arterial pressure, and inhibited muscularization in small pulmonary vessels. However, only a few male donor cells were detected from 1 day to 1 mo after BMC administration. The MSCs and cell-free MSC-CM also induced the repair of emphysema and increased the number of small pulmonary vessels. Our data show that BMC, MSCs, and MSC-CM treatment repaired cigarette smoke-induced emphysema. The repair activity of these treatments is consistent with a paracrine effect rather than stem cell engraftment because most of the donor cells disappeared and because cell-free MSC-CM also induced the repair.

Impaired endothelial progenitor cell mobilization and colony-forming capacity in chronic obstructive pulmonary disease

BACKGROUND AND OBJECTIVE

Recent studies suggest that there is endothelial impairment in both the systemic and pulmonary circulations of patients with COPD. Endothelial progenitor cells (EPC) are mobilized into the circulation by physiological stressors such as surgery, and are thought to play a role in the repair of damaged endothelium. There has been a steady increase in the frequency of surgery among COPD patients, due to the incidence of complications and lung cancer; however, the mobilization of EPC during lung resection has not been examined. We evaluated whether the mobilization and proliferation of EPC are impaired in COPD patients.

METHODS

The numbers of circulating EPC (CD34/KDR/AC133-positive mononuclear cells) were measured by flow cytometry, in COPD patients (n=30) and non-COPD patients (n=30) who were undergoing thoracic surgery. EPC colony-forming units (EPC-CFU) were also examined.

RESULTS

In non-COPD patients, both circulating EPC and EPC-CFU were significantly increased 2h after the operation started, whereas in COPD patients there were no changes in circulating EPC or EPC-CFU, irrespective of the severity of COPD. Multiple linear regression analysis demonstrated that the presence of COPD was the only significant independent predictor of reduced mobilization of EPC during thoracic surgery.

CONCLUSIONS

The number of circulating EPC and EPC-CFU was not increased during thoracic surgery in COPD patients. These results indicate that both the mobilization and proliferative capacity of EPC are severely impaired in COPD patients.

Pro-angiogenic hematopoietic progenitor cells and endothelial colony-forming cells in pathological angiogenesis of bronchial and pulmonary circulation

Dysregulation of angiogenesis is a common feature of many disease processes. Vascular remodeling is believed to depend on the participation of endothelial progenitor cells, but the identification of endothelial progenitors in postnatal neovascularization remains elusive. Current understanding posits a role for circulating pro-angiogenic hematopoietic cells that interact with local endothelial cells to establish an environment that favors angiogenesis in physiologic and pathophysiologic responses. In the lung, increased and dysregulated angiogenesis is a hallmark of diseases of the bronchial and pulmonary circulations, manifested by asthma and pulmonary arterial hypertension (PAH), respectively. In asthma, T(Helper)-2 immune cells produce angiogenic factors that mobilize and recruit pro-inflammatory and pro-angiogenic precursors from the bone marrow into the airway wall where they induce angiogenesis and fuel inflammation. In contrast, in PAH, upregulation of hypoxia-inducible factor (HIF) in vascular cells leads to the production of bone marrow-mobilizing factors that recruit pro-angiogenic progenitor cells to the pulmonary circulation where they contribute to angiogenic remodeling of the vessel wall. This review focuses on current knowledge of pro-angiogenic progenitor cells in the pathogenesis of asthma and PAH.

COPD: a multifactorial systemic disease

Chronic obstructive pulmonary disease (COPD) has traditionally been considered a disease of the lungs secondary to cigarette smoking and characterized by airflow obstruction due to abnormalities of both airway (bronchitis) and lung parenchyma (emphysema). It is now well known that COPD is associated with significant systemic abnormalities, such as renal and hormonal abnormalities, malnutrition, muscle wasting, osteoporosis, and anemia. However, it is still unclear whether they represent consequences of the pulmonary disorder, or whether COPD should be considered as a systemic disease. These systemic abnormalities have been attributed to an increased level of systemic inflammation. Chronic inflammation, however, may not be the only cause of the systemic effects of COPD. Recent data from humans and animal models support the view that emphysema may be a vascular disease. Other studies have highlighted the role of repair failure, bone marrow abnormality, genetic and epigenetic factors, immunological disorders and infections as potential causes of COPD systemic manifestations. Based on this new evidence, it is reasonable to consider COPD, and emphysema in particular, as 'a disease with a significant systemic component' if not a 'systemic disease' per se. The aim of this review is to give an overview of the most relevant and innovative hypothesis about the extrapulmonary manifestations of COPD.

Mesenchymal stem cells for repair of the airway epithelium in asthma

The airway epithelium is constantly faced with inflammatory and potentially injurious stimuli. Following damage, rapid repair mechanisms involving proliferation and differentiation of resident progenitor and stem cell pools are necessary in order to maintain a protective barrier. In asthma, evidence pointing to a compromised ability of the epithelium to properly repair and regenerate is rapidly accumulating. The consequences of this are presently unknown but are likely to have a significant impact on lung function. Mesenchymal stem cells have the potential to serve as a universal source for replacement of specific cells in several diseases and thus offer hope as a potential therapeutic intervention for the treatment of the chronic remodeling changes that occur in the asthmatic epithelium. However, controversy exists regarding whether these cells can actually home to and engraft within the airways and contribute to tissue function or whether this mechanism is necessary, since they can have potent paracrine immunomodulatory effects. This article focuses on the current knowledge about specific stem cell populations that may contribute to airway epithelial regeneration and discusses the use of mesenchymal stem cells as a potential therapeutic intervention.

Unicentric study of cell therapy in chronic obstructive pulmonary disease/pulmonary emphysema

Within the chronic obstructive pulmonary disease (COPD) spectrum, lung emphysema presents, as a primarily histopathologic feature, the destruction of pulmonary parenchyma and, accordingly, an increase in the airflow obstruction distal to the terminal bronchiole. Notwithstanding the significant advances in prevention and treatment of symptoms, no effective or curative therapy has been accomplished. In this context, cellular therapy with stem cells (SCs) arises as a new therapeutic approach, with a wide application potential. The purpose of this study is to evaluate the safety of SCs infusion procedure in patients with advanced COPD (stage IV dyspnea). After selection, patients underwent clinical examination and received granulocyte colony-stimulating factor, immediately prior to the bone marrow harvest. The bone marrow mononuclear cells (BMMC) were isolated and infused into a peripheral vein. The 12-month follow-up showed a significant improvement in the quality of life, as well as a clinical stable condition, which suggest a change in the natural process of the disease. Therefore, the proposed methodology in this study for BMMC cell therapy in sufferers of advanced COPD was demonstrated to be free of significant adverse effects. Although a larger sample and a greater follow-up period are needed, it is possible to infer that BMMC cell therapy introduces an unprecedented change in the course or in the natural history of emphysema, inhibiting or slowing the progression of disease. This clinical trial was registered with ClinicalTrials.gov (NCT01110252) and was approved by the Brazilian National Committee of Ethics in Research (registration no. 14764, CONEP report 233/2009).

Hemopoietic and angiogenetic progenitors in healthy athletes: different responses to endurance and maximal exercise

The effects of endurance or maximal exercise on mobilization of bone marrow-derived hemopoietic and angiogenetic progenitors in healthy subjects are poorly defined. In 10 healthy amateur runners, we collected venous blood before, at the end of, and the day after a marathon race (n = 9), and before and at the end of a 1.5-km field test (n = 8), and measured hemopoietic and angiogenetic progenitors by flow cytometry and culture assays, as well as plasma or serum concentrations of several cytokines/growth factors. After the marathon, CD34(+) cells were unchanged, whereas clonogenetic assays showed decreased number of colonies for both erythropoietic (BFU-E) and granulocyte-monocyte (CFU-GM) series, returning to baseline the morning post-race. Conversely, CD34(+) cells, BFU-E, and CFU-GM increased after the field test. Angiogenetic progenitors, assessed as CD34(+)KDR(+) and CD133(+)VE-cadherin(+) cells or as adherent cells in culture expressing endothelial markers, increased after both endurance and maximal exercise but showed a different pattern between protocols. Interleukin-6 increased more after the marathon than after the field test, whereas hepatocyte growth factor and stem cell factor increased similarly in both protocols. Plasma levels of angiopoietin (Ang) 1 and 2 increased after both types of exercise, whereas the Ang-1-to-Ang-2 ratio or vascular endothelial growth factor-A were little affected. These data suggest that circulating hemopoietic progenitors may be utilized in peripheral tissues during prolonged endurance exercise. Endothelial progenitor mobilization after exercise in healthy trained subjects appears modulated by the type of exercise. Exercise-induced increase in growth factors suggests a physiological trophic effect of exercise on the bone marrow.

Cancer risk assessment and the genetic counseling process: using hereditary breast and ovarian cancer as an example

While only a small proportion of cancers can be attributed to a hereditary susceptibility, identifying high-risk individuals plays an essential role in medical management and has a significant impact on the patient as well as their immediate and extended family members. This paper aims at increasing the medical professionals' knowledge of the components of a genetic counseling session, with particular attention toward identifying at-risk individuals and understanding the complexities of the testing process. In addition, tools are provided to assist in identifying these individuals in clinical practice and streamlining the referral process to a cancer genetics center.