CD133+ cells in pulmonary arterial hypertension

Vasile Foris, Gabor Kovacs, Leigh M. Marsh, Zoltán Bálint, Martin Tötsch, Alexander Avian, Philipp Douschan, Bahil Ghanim, Walter Klepetko, Andrea Olschewski, Horst Olschewski
European Respiratory Journal 2016 48: 459-469; DOI: 10.1183/13993003.01523-2015

Abstract

Circulating mononuclear cells may play an important role for the vascular remodelling in pulmonary arterial hypertension (PAH), but studies addressing multiple progenitor populations are rare and inconsistent.

We used a comprehensive fluorescence-activated cell sorting analysis of circulating mononuclear cells in 20 PAH patients and 20 age- and sex-matched controls, and additionally analysed CD133+ cells in the lung tissue of five PAH transplant recipients and five healthy controls (donor lungs).

PAH patients were characterised by increased numbers of circulating CD133+ cells and lymphopenia as compared with control. In PAH, CD133+ subpopulations positive for CD117 or CD45 were significantly increased, whereas CD133+CD309+, CD133+CXCR2+ and CD133+CD31+ cells were decreased. In CD133+ cells, SOX2, Nanog, Ki67 and CXCR4 were not detected, but Oct3/4 mRNA was present in both PAH and controls. In the lung tissue, CD133+ cells included three main populations: type 2 pneumocytes, monocytes and undifferentiated cells without significant differences between PAH and controls.

In conclusion, circulating CD133+ progenitor cells are elevated in PAH and consist of phenotypically different subpopulations that may be up- or downregulated. This may explain the inconsistent results in the literature. CD133+ type 2 pneumocytes in the lung tissue are not associated with circulating CD133+ mononuclear cells.

Abstract

PAH patients are characterised by lymphopenia and increased numbers of CD133+ cells http://ow.ly/YNfQE

Introduction

Circulating cell populations may play an important role among the different pathologic mechanisms underlying pulmonary hypertension [1, 2]. According to recent studies, circulating mesenchymal precursors of the monocyte/macrophage lineage as well as c-kit+ cells accumulate in the remodelled arteries of patients and contribute to the thickening of the vessel wall [3–5]. In addition, circulating endothelial progenitor cells (EPCs), fibrocytes and mast cells may also contribute to the development of the disease [6–8]. In contrast, it has been shown that circulating cells may be protective against the development of pulmonary hypertension, as regulatory T-cells were able to limit pulmonary vascular injury and endothelial dysfunction [9].

Due to the differences in the number and composition of circulating cells between pulmonary arterial hypertension (PAH) and controls, circulating cells have been discussed as potential biomarkers for the disease [10]. Elevated levels of circulating EPCs have been reported in PAH patients [8, 11]. However, idiopathic PAH (IPAH), Eisenmenger and sickle cell disease-related PAH patients had lower levels of EPCs than controls [12–14]. A potential explanation for the apparently contradictory results is that there is no generally accepted standard for the phenotypic characterisation and definition of these cell populations [15]. Missing standards for cell isolation as well as differences in the pathologic mechanisms of the investigated patients may also have contributed to these discrepancies. Further investigations are necessary to determine whether the number of circulating progenitors is a suitable marker of PAH and what role these cells may play in the pathology of the disease [15].

In this study, we aimed to characterise circulating progenitor cell populations in PAH patients using a multimodal approach, where we employed a combination of surface markers of mononuclear cells and found that the relative number of CD133+ cells was elevated and the relative number of fibrocytes was decreased in PAH as compared with matched healthy controls. Due to their putative importance, CD133+ cells were identified in the lung tissue of PAH patients and healthy donors, and were identified as type 2 pneumocytes, inflammatory cells and undifferentiated cells, but none of them accumulated in the pulmonary vessel wall.

Methods

Patient characteristics

This explorative study was approved by the ethics committee of the Medical University of Graz (23-408 ex 10/11). Written informed consent was obtained from all study participants. Patients with PAH (mean pulmonary arterial pressure ≥25 mmHg, pulmonary arterial wedge pressure ≤15 mmHg with no significant heart, lung, liver, kidney and blood diseases) undergoing diagnostic or follow-up right heart catheterisation were included in a prospective manner. Age (±5 years)- and sex-matched healthy volunteers selected on a 1:1 basis served as controls. Blood (3 mL) was taken from n=20 PAH patients within 30 days of right heart catheterisation and from their individual controls (n=20) from an antecubital vein in EDTA-containing Vacutainer® tubes. The samples were processed within 1 h after the blood was drawn. For a subgroup of patients, blood was drawn in parallel from an antecubital vein and a peripheral artery, and was analysed for CD133+ cells. As there were no significant differences (online supplementary figure S4), blood was drawn from the antecubital vein only for the remainder of the study.

The second part of the study focused on the identification of CD133+ cells in the lung tissue. This tissue was obtained from n=5 IPAH patients undergoing lung transplantation in Vienna and from n=5 donor lungs not used for transplantation. The study protocol for tissue donation was approved by the ethical committee of the Medical University of Vienna (976/2010).

Fluorescence-activated cell sorting

Peripheral blood mononuclear cells (PBMCs) were isolated via Ficoll-Paque PLUS (GE Healthcare Life Sciences, Vienna, Austria) density gradient centrifugation. The obtained mononuclear cells were washed twice in phosphate-buffered saline (PBS) and resuspended in PBS containing 1% bovine serum albumin (BSA). Prior to staining, nonspecific antibody binding was blocked via incubation with Fc-receptor-binding inhibitor (eBioscience, Vienna, Austria) for 20 min on ice. Cells were stained simultaneously with fluorescent-conjugated antibodies against the following cell surface markers or their respective isotype controls: CD117 (c-kit), CXCR2, CD309, CD34, CD14, CD31, CD133, CD16 and CD45 (for detailed information, refer to table 1 and online supplementary table S1). The cells were then incubated for 30 min at 4°C. Flow cytometric analysis was performed and analysed on a LSR II with FACSDIVA software version 6.2 (both from Becton Dickinson Biosciences, Oxford, UK). Automatic and manual adjusted compensation was used with single-colour-stained samples. Instrument configuration is given in online supplementary table S2; a compensation matrix is shown in online supplementary table S3. A minimum of 50 000 events was recorded. After exclusion of cell debris and doublets, lymphocytes and monocytic cells were gated. The regions of interest were selected according to the negative and isotype controls. A detailed gating strategy is shown in figure 1.

View this table:
TABLE 1

Clusters of differentiation of the investigated antigens

FIGURE 1
FIGURE 1

Gating strategy for the detection of cell populations from peripheral blood mononuclear cells. A representative example of a pulmonary arterial hypertension patient is shown. Gating for lymphocytic and monocytic cells is demonstrated (x-axis: forward scatter (FSC); y-axis: side scatter (SSC)). CD133+ cells were identified from the lymphocytic gate. Next, double-positive events were gated from the lymphocytic region. Monocytes were identified according to the expression of CD16 and CD14. Fibrocytes were identified from the CD45+ and CD14+ monocytes defining them as a CD34+CD45+CD14+ subpopulation of mononuclear cells. APC: allophycocyanin; PE: phycoerythrin; PerCP: peridinin chlorophyll; AF: Alexa Fluor.

Cytospin and immunofluorescent staining

PBMCs (from n=5 patients with PAH and n=5 healthy controls) were obtained as previously described. Cells were stained with fluorescence-labelled antibodies against CD133. Briefly, 20 000 cells were diluted in 200 µL PBS containing 1% BSA and put onto microscope slides using the cytospin technique. After fixation with 1.4% paraformaldehyde the slides were mounted with Vectashield® Mounting Medium containing 4′,6-diamidino-2-phenylindole (Vector Laboratories, Burlingame, CA, USA). Negative controls were performed with the isotype-specific antibodies. A Zeiss LSM 510 META (Carl Zeiss, Jena, Germany) scanning laser confocal microscope was used for visualisation.

ELISA

The ELISA for the soluble CD133 (prominin-1) was performed according to the manufacturer's protocol (BIOTREND Chemikalien, Cologne, Germany). Plasma was isolated from blood samples obtained from the patients (n=20) and controls (n=20). Blood samples were kept on ice until centrifugation. Plasma was obtained within 1 h of blood draw, aliquoted and stored at −80°C in the Biobank of the Medical University of Graz.

Immunohistochemistry and immunofluorescence

In order to assess the localisation of CD133+ cells in the lung tissue, we stained n=5 IPAH and n=5 healthy donor lung tissues for this marker using immunohistochemistry and tissue immunofluorescence. The slides were analysed by an expert pathologist in lung cytology (M.T.) and positive cells were counted by means of Visiopharm (Hørsholm, Denmark) software. For a detailed description, see the online supplementary material.

Real-time PCR

Gene expression changes in CD133+ cells were investigated using real-time PCR using a LightCycler 480 (Roche, Mannheim, Germany). Genes which are known to be expressed in stem cells (Oct3/4, SOX2, Nanog, CXCR4 and Ki67) were selected for this set of experiments. Primer sequences are given in online supplementary table S4. The ΔCT method was used for calculation of mRNA expression, with β2-macroglobulin as the reference gene. A detailed description is given in the online supplementary material.

Statistical analysis

Data are presented as mean±sd or median (interquartile range (IQR)). Statistical analysis was performed using Prism software version 5.04 (GraphPad, La Jolla, CA, USA). The nonparametric Mann–Whitney U-test was used for calculation of differences between groups.

Results

Fluorescence-activated cell sorting

The characteristics of the 20 PAH patients for this pilot study are given in table 2. The healthy matched controls consisted of 15 females and five males with a mean±sd age of 56.3±13.4 years.

View this table:
TABLE 2

Individual characteristics of the 20 pulmonary arterial hypertension (PAH) patients

Monocytes (expressed as percentage of lymphomonocytic cells) were elevated in PAH as compared with controls (figure 2a; PAH median (IQR) 23.6% (15.2–31.6) versus control 12.4% (7.6–16.7), p<0.001), whereas lymphocytes were decreased in PAH as compared with controls (figure 2b; PAH median (IQR) 73.4% (64.5–80.4) versus control 86.9% (81.4–91.3), p<0.001).

FIGURE 2
FIGURE 2

Peripheral blood mononuclear cells were stained and analysed using flow cytometry from n=20 pulmonary arterial hypertension (PAH) patients and n=20 age- and sex-matched healthy donors (Control). Data were analysed using the nonparametric Mann–Whitney U-test. Data are presented as median and interquartile range.

Using a novel gating strategy (figure 1) we identified putative progenitors as CD34+CD133+ double-positive cells from the lymphocytic gate. These cells did not express the chemokine receptor CXCR2, the macrophage/granulocyte marker CD16, vascular endothelial growth factor receptor 2, CD309 (also known as KDR) or CD117 (c-kit), i.e. there were no triple-positive events (CD34+CD133+CXCR2+, CD34+CD133+CD16+, CD34+CD133+CD309+ or CD34+CD133+CD117+) neither in PAH nor in controls (data not shown). This suggests that cells expressing both CD34+ and CD133+ are undifferentiated in the peripheral blood. One PAH patient had to be excluded post hoc from the analysis due to an insufficient number of lymphocytic cells.

The contribution of CD133+ cells to the circulating lymphocytic cells was significantly elevated in PAH as compared with controls (figure 2c; PAH median (IQR) 0.6% (0.4–1) versus control 0.3% (0.2–0.5), p<0.003). A CD133+ circulating EPC population is depicted in figure 2 expressed as percentage of the gated lymphocytic cells. Since the CD133+ population was identified from the lymphocytic cells and lymphocytes were lower in PAH as compared with controls, we also compared the arithmetical product of these two fractions. This revealed that the number of CD133+ cells in relation to the number of PBMCs was still significantly higher in PAH as compared with controls (figure 2d; PAH median (IQR) 0.4% (0.3–0.6) versus control 0.2% (0.2–0.5), p=0.036). The proportion of circulating CD133+ cells positive for CD45 (CD133+CD45+), indicating their bone marrow origin, was also significantly increased in PAH as compared with controls (figure 2e; PAH median (IQR) 66.7% (53.3–85.1) versus control 57% (40.4–66.6), p=0.047). Another subpopulation of CD133+ cells that was elevated in PAH as compared with controls was CD133+CD117+ (figure 2f; PAH median (IQR) 31.4% (24.6–56.9) versus control 21.9% (10.9–30), p<0.004).

We also identified subpopulations of CD133+ cells that were lower in PAH as compared with controls, i.e. CD133+CD309+ cells (figure 2g; PAH median (IQR) 10.2% (4.4–14.9) versus control 23.5% (16.2–32.1), p=0.002), CD133+CD31+ cells (figure 2h; PAH median (IQR) 44.1 (34–68.7) versus control 70.7% (60–78.2), p=0.001) and CD133+CXCR2+ cells (figure 2i; PAH median (IQR) 34.7% (25.7–40.2) versus control 38.7% (34.9–43.7), p=0.047).

The cells derived from the monocytic gate were mostly CD14+. However, the relative contribution of CD14+, CD14–, CD16+ and CD16– cells was not different between PAH and controls. The contribution of monocytic cells of bone marrow origin (CD45+CD14+) derived from the lymphomonocytic gate was higher in PAH (figure 2j; PAH median (IQR) 20.2% (16.2–29.6) versus control 12.2% (8.6–15.7), p<0.001).

In addition, circulating fibrocytes of bone marrow origin (CD34+CD45+CD14+) were decreased in PAH as compared with controls (figure 2k; PAH median (IQR) 0.3% (0.1–0.8) versus control 1.2% (0.8–1.5), p<0.001). In an independent set of experiments, peripheral and central blood was taken from patients with PAH and fluorescence-activated cell sorting was performed as described above. There was no difference between the number of circulating progenitors between central and peripheral blood (online supplementary figure S4).

Characterisation of CD133+ cells

Multiple cytospin preparations of mononuclear cells isolated from healthy controls as well as IPAH patients were examined. Positive staining for CD133 was observed on the cell membrane of a small percentage of isolated cells. Phenotypically, the nuclei of these cells were small and condensed. A representative image from an IPAH patient is shown in figure 3. Real-time PCR was performed in order to assess the level of CD133 mRNA in lung homogenates of eight IPAH patients and eight donors. At the mRNA level, CD133 in tissue homogenate did not show any difference between patients and controls (mean±sd IPAH ΔCT= −12.8±4.6 versus control ΔCT= −12.9±7.5, p=0.87). cDNA was obtained from isolated CD133 cells. CD133+ cells did not express SOX2, Nanog, CXCR4 and Ki67 as assessed by real-time PCR. The transcription factor Oct3/4 was expressed an the mRNA level in CD133+ cells derived from PAH and controls with no significant differences (p=0.400; online supplementary figure S1).

FIGURE 3
FIGURE 3

Immunofluorescent staining of mononuclear cytospin preparations against CD133. n=5 pulmonary arterial hypertension patients were investigated. Representative image of an idiopathic PAH patient is shown. DAPI: 4′,6-diamidino-2-phenylindole. Scale bar: 5 µm.

ELISA

Plasma samples were analysed for the soluble form of CD133 (prominin-1). As shown in online supplementary figure S2, there were no significant differences between PAH and controls (median (IQR) 0.037 (0.024–0.228) versus 0.027 (0.017–0.191) ng·mL−1, p=0.16).

Immunohistochemistry and immunofluorescence

In IPAH lung tissue the cells that stained positive for CD133 were predominantly type 2 pneumocytes. Other cell types were also occasionally CD133+ and may be described as inflammatory cells or undifferentiated cells (figure 4). There were no apparent differences regarding localisation or number of CD133+ cells between IPAH and donor lung tissues. Figure 5a–e depicts a representative example of serial staining of an IPAH lung. The surface epithelial cells of the alveoli which are larger and cuboidal were identified as type 2 pneumocytes. They are positive for the markers mucin-1 (MUC-1) and surfactant protein C (SPC). CD133+ cells which are located in the alveolar septum mostly represent type 2 pneumocytes. However, not all type 2 pneumocytes express CD133. A representative image is shown in figure 5f. MUC-1 stained most of the CD133+ cells; however, not all type 2 pneumocytes were positive for CD133, which is also shown in the immunohistological staining.

FIGURE 4
FIGURE 4

Representative CD133 immunohistochemical staining of a) donor and b) idiopathic pulmonary arterial hypertension (IPAH) lung tissue. Scale bar: 100 µm. i–iii) Enlargements of the regions in b) indicating characteristic cells (arrows): i) type 2 pneumocyte, ii) undifferentiated cell and iii) inflammatory cell. c) Representative CD133 immunofluorescent staining of IPAH lung tissue. CD133 is stained in red, von Willebrand Factor is stained in green. Scale bar: 10 µm. The enlargement indicates a CD133+ circulating cell in an arteriole.

FIGURE 5
FIGURE 5

Representative immunohistochemical staining of an idiopathic pulmonary arterial hypertension lung tissue. The enlargements show characteristic cells (arrows): a) negative, b) double staining with smooth muscle cell actin (SMA) and von Willebrand Factor (vWF), c) CD133, d) mucin-1 (MUC-1), and e) surfactant protein C (SPC). f) Double immunofluorescent staining with CD133 and MUC-1: i) MUC-1+ type 2 pneumocyte, ii) MUC-1+ and CD133+ type 2 pneumocyte, and iii) CD133+ undifferentiated cell. DAPI: 4′,6-diamidino-2-phenylindole. Scale bar: a–d) main, 50 µm; enlargement, 20 µm; f) main, 20 µm; enlargement, 10 µm.

Discussion

Technical approach and study population

In contrast to previous studies, we used a more comprehensive gating strategy for quantification of circulating progenitor cells. As the CD133+ population consists of phenotypically diverse subpopulations characterised by the presence of different leukocyte antigens [16], we used a set of stem cell, leukocyte/monocyte and differentiation markers. This applies especially to EPCs, expressing CD133, a member of the prominin family of pentaspan membrane glycoproteins [17]. The leukocyte/monocyte antigens CD45 and CD14 were detectable in the CD133+ population, leading to the conclusion that CD133+ progenitors are mobilised from the bone marrow. During the process of mobilisation and maturation, CD133+ cells may change their phenotype by releasing CD133-containing membrane vesicles [18]. We showed that some subpopulations of CD133+ cells are elevated in PAH, whereas some are decreased as compared with controls. EPCs are essentially hematopoietic cells with variable expression of CD34, CD133 and CD45. The expression of multiple markers for different EPC populations reflects the heterogeneous nature of these cells [19].

Circulating progenitor cells and inflammatory cells as potential biomarkers

Circulating cells are easily accessible (i.e. from peripheral blood), and therefore suitable as biomarkers of disease severity and for PAH screening. A recent investigation revealed that the number of progenitor cells in chronic obstructive pulmonary disease (COPD) patients with pulmonary hypertension was higher than in COPD without pulmonary hypertension [20]. In contrast, Diller et al. [8] found that the numbers of circulating CD34+, CD34+CD133+, CD34+CD309+ and CD34+CD133+CD309+ cells were lower in Eisenmenger patients as compared with healthy controls, while IPAH patients showed elevated levels of circulating endothelial cells, but not of EPCs (CD34+, CD133+). Our results demonstrate increased numbers of CD133+ cells and are in line with Toshner et al. [8] who reported that CD133+CD34+CD309+ cells were elevated in IPAH patients as compared with controls. The discrepancy between the results of Toshner et al. [8] and Diller et al. [8] may be due to the different patient populations and cell populations that were investigated. Many studies have suggested that inflammation plays an important role in pulmonary hypertension [21–27]. We found that the number of circulating lymphocytes was significantly reduced in PAH patients, whereas circulating monocytes were elevated as compared with controls. We can only speculate on the nature of the missing lymphocytes and it remains an open question if these cells are abundantly recruited in the tissue or if their production is reduced in PAH.

Challenges of progenitor biology in PAH

For many years the characterisation of circulating EPCs has been a matter of debate. Currently, there is no specific marker or combination of markers that reliably defines EPCs both phenotypically and functionally. In our study, phenotypically different subpopulations were detectable and were elevated in PAH patients. This might also indicate that the pulmonary vasculopathy, especially the elevated pulmonary pressure, is a driving force for the mobilisation of these cells from the bone marrow. Alternatively, it could indicate that the elevation of the total CD133+ population is pathogenic in PAH. Indeed, it was shown that CD133 cells from PAH patients caused pulmonary hypertension in the nude mouse [28]. Of note, in that study mostly patients with hereditary PAH were enrolled and the responses in the mouse seemed to be patient-specific, suggesting that there may be a complex interaction with other factors.

There is evidence that phosphodiesterase type 5 inhibitors, endothelin receptor antagonists and prostacyclin therapy may affect the number and function of some circulating progenitor cells [29–33]. However, it is not clear if the change in the number of circulating cells affects the severity of PAH. In our study it was not possible to perform subgroup comparisons due to the small sample size.

Molecular characterisation of progenitor cells

We did not find a significant increase in plasma levels of soluble CD133 in our patient cohort; however, we observed a trend towards increased levels in PAH. Compared with that, CD133 in tissue homogenate at the mRNA level did not show any difference between patients and controls, which indicates that the contribution of these cells to the pathogenesis of pulmonary hypertension remains unclear. There may be a paracrine function because the transcription factor Oct3/4, a marker of stem cells, is expressed in the CD133+ cells from both PAH patients and healthy controls. Oct3/4 has often been used as a marker of self-renewal capacity [34]. This could suggest that circulating CD133+ cells may not be lineage committed.

Progenitor cells in the lung tissue

The homing of the circulating progenitor cells remains unclear. It was recently shown that in end-stage lung diseases with pulmonary hypertension there was an increase in the endothelial progenitors in the lung tissue as compared with donor samples [35]. In our study, the main cell population expressing CD133 in the lung tissues was located in the alveolar/septal junction and consisted of type 2 pneumocytes. To the best of our knowledge, this has not been reported previously. Type 2 pneumocytes secrete surfactant and differentiate into type 1 pneumocytes following lung injury. This may indicate that CD133+ type 2 pneumocytes play a role in maintaining the cellularity of the alveolar surface. Our finding is supported by a previous study showing that in the bleomycin-induced fibrosis model, CD133+ epithelial cells were protective against lung injury [36]. In addition to type 2 pneumocytes, CD133+ cells were also found in the adventitia of vessels where they phenotypically resembled monocytes or undifferentiated cells. In agreement with our data, Woo et al. [37] found that CD133 was expressed by some of the alveolar epithelial cells in non-neoplastic lung tissue. It remains an open question if the CD133+ type 2 cells, the adventitial cells and the circulating mononuclear cells are related to each other.

Limitations of the study

The low number of PAH patients included (n=20) is an obvious limitation; however, PAH is a rare disease and our patients were haemodynamically well characterised by right heart catheterisation. In addition, our healthy controls were tightly age- and sex-matched to the investigated PAH patients. The lung histology was only performed on end-stage IPAH patients at the time of lung transplantation; however, lung biopsies from patients at an earlier stage are rarely available.

Conclusions

PAH patients are characterised by an elevation of circulating CD133+ progenitor cells and by lymphopenia. Bone marrow-derived circulating CD133 progenitor cells are heterogeneous with respect to their phenotype. In the lung tissue, CD133+ cells consist of phenotypically different populations, mainly consisting of type 2 pneumocytes and some adventitial monocytes and undifferentiated cells.

Acknowledgements

The authors would like to thank Dr Daniela Kleinschek, Ida Niklasson, Lisa Oberreiter and the members of the Biobank of the Medical University of Graz for excellent technical assistance. The blood samples used in this study were stored and kindly provided by the Biobank of the Medical University of Graz.

Footnotes

  • This article has supplementary material available from erj.ersjournals.com

  • Support statement: This study was funded by the Ludwig Boltzmann Institute for Lung Vascular Research and the Medical University of Graz. Funding information for this article has been deposited with FundRef.

  • Conflict of interest: Disclosures can be found alongside the online version of this article at erj.ersjournals.com

  • Received September 11, 2015.
  • Accepted February 22, 2016.

References

  1. ↵
    1. Farkas L,
    2. Kolb M
    . Vascular repair and regeneration as a therapeutic target for pulmonary arterial hypertension. Respir Int Rev Thorac Dis 2013; 85: 355–364.
    OpenUrl
  2. ↵
    1. Wilkins MR
    . Pulmonary hypertension: the science behind the disease spectrum. Eur Respir Rev 2012; 21: 19–26.
    OpenUrlAbstract/FREE Full Text
  3. ↵
    1. Montani D,
    2. Perros F,
    3. Gambaryan N, et al.
    C-kit-positive cells accumulate in remodeled vessels of idiopathic pulmonary arterial hypertension. Am J Respir Crit Care Med 2011; 184: 116–123.
    OpenUrlCrossRefPubMedWeb of Science
    1. Gambaryan N,
    2. Perros F,
    3. Montani D, et al.
    Targeting of c-kit+ haematopoietic progenitor cells prevents hypoxic pulmonary hypertension. Eur Respir J 2011; 37: 1392–1399.
    OpenUrlAbstract/FREE Full Text
  5. ↵
    1. Gambaryan N,
    2. Perros F,
    3. Montani D, et al.
    Imatinib inhibits bone marrow-derived c-kit+ cell mobilisation in hypoxic pulmonary hypertension. Eur Respir J 2010; 36: 1209–1211.
    OpenUrlFREE Full Text
  6. ↵
    1. Yeager ME,
    2. Nguyen CM,
    3. Belchenko DD, et al.
    Circulating fibrocytes are increased in children and young adults with pulmonary hypertension. Eur Respir J 2012; 39: 104–111.
    OpenUrlAbstract/FREE Full Text
    1. Farha S,
    2. Sharp J,
    3. Asosingh K, et al.
    Mast cell number, phenotype, and function in human pulmonary arterial hypertension. Pulm Circ 2012; 2: 220–228.
    OpenUrlCrossRefPubMed
  8. ↵
    1. Toshner M,
    2. Voswinckel R,
    3. Southwood M, et al.
    Evidence of dysfunction of endothelial progenitors in pulmonary arterial hypertension. Am J Respir Crit Care Med 2009; 180: 780–787.
    OpenUrlCrossRefPubMedWeb of Science
  9. ↵
    1. Tamosiuniene R,
    2. Tian W,
    3. Dhillon G, et al.
    Regulatory T cells limit vascular endothelial injury and prevent pulmonary hypertension. Circ Res 2011; 109: 867–879.
    OpenUrlAbstract/FREE Full Text
  10. ↵
    1. Foris V,
    2. Kovacs G,
    3. Tscherner M, et al.
    Biomarkers in pulmonary hypertension: what do we know? Chest 2013; 144: 274.
    OpenUrlCrossRefPubMedWeb of Science
  11. ↵
    1. Asosingh K,
    2. Aldred MA,
    3. Vasanji A, et al.
    Circulating angiogenic precursors in idiopathic pulmonary arterial hypertension. Am J Pathol 2008; 172: 615–627.
    OpenUrlCrossRefPubMedWeb of Science
  12. ↵
    1. Junhui Z,
    2. Xingxiang W,
    3. Guosheng F, et al.
    Reduced number and activity of circulating endothelial progenitor cells in patients with idiopathic pulmonary arterial hypertension. Respir Med 2008; 102: 1073–1079.
    OpenUrlCrossRefPubMedWeb of Science
    1. Diller G-P,
    2. van Eijl S,
    3. Okonko DO, et al.
    Circulating endothelial progenitor cells in patients with Eisenmenger syndrome and idiopathic pulmonary arterial hypertension. Circulation 2008; 117: 3020–3030.
    OpenUrlAbstract/FREE Full Text
  14. ↵
    1. Anjum F,
    2. Lazar J,
    3. Zein J, et al.
    Characterization of altered patterns of endothelial progenitor cells in sickle cell disease related pulmonary arterial hypertension. Pulm Circ 2012; 2: 54–60.
    OpenUrlCrossRefPubMed
  15. ↵
    1. Tuder RM,
    2. Archer SL,
    3. Dorfmüller P, et al.
    Relevant issues in the pathology and pathobiology of pulmonary hypertension. J Am Coll Cardiol 2013; 62: 25 Suppl., D4–D12.
    OpenUrl
  16. ↵
    1. Calloni R,
    2. Cordero EAA,
    3. Henriques JAP, et al.
    Reviewing and updating the major molecular markers for stem cells. Stem Cells Dev 2013; 22: 1455–1476.
    OpenUrlCrossRefPubMedWeb of Science
  17. ↵
    1. Fargeas CA,
    2. Corbeil D,
    3. Huttner WB
    . AC133 antigen, CD133, prominin-1, prominin-2, etc.: prominin family gene products in need of a rational nomenclature. Stem Cells 2003; 21: 506–508.
    OpenUrlCrossRefPubMedWeb of Science
  18. ↵
    1. Bauer N,
    2. Wilsch-Bräuninger M,
    3. Karbanová J, et al.
    Haematopoietic stem cell differentiation promotes the release of prominin-1/CD133-containing membrane vesicles – a role of the endocytic–exocytic pathway. EMBO Mol Med 2011; 3: 398–409.
    OpenUrlAbstract/FREE Full Text
  19. ↵
    1. Untergasser G,
    2. Koeck R,
    3. Wolf D, et al.
    CD34+/CD133– circulating endothelial precursor cells (CEP): characterization, senescence and in vivo application. Exp Gerontol 2006; 41: 600–608.
    OpenUrlCrossRefPubMedWeb of Science
  20. ↵
    1. Pizarro S,
    2. García-Lucio J,
    3. Peinado VI, et al.
    Circulating progenitor cells and vascular dysfunction in chronic obstructive pulmonary disease. PloS One 2014; 9: e106163.
    OpenUrlCrossRefPubMed
  21. ↵
    1. Zabini D,
    2. Heinemann A,
    3. Foris V, et al.
    Comprehensive analysis of inflammatory markers in chronic thromboembolic pulmonary hypertension patients. Eur Respir J 2014; 44: 951–962.
    OpenUrlAbstract/FREE Full Text
    1. Pugliese SC,
    2. Poth JM,
    3. Fini MA, et al.
    The role of inflammation in hypoxic pulmonary hypertension: from cellular mechanisms to clinical phenotypes. Am J Physiol Lung Cell Mol Physiol 2015; 308: L229–L252.
    OpenUrlAbstract/FREE Full Text
    1. Hautefort A,
    2. Girerd B,
    3. Montani D, et al.
    T-helper 17 polarization in pulmonary arterial hypertension. Chest 2015; 147: 1610–1620.
    OpenUrlCrossRefPubMed
    1. Burke DL,
    2. Frid MG,
    3. Kunrath CL, et al.
    Sustained hypoxia promotes the development of a pulmonary artery-specific chronic inflammatory microenvironment. Am J Physiol Lung Cell Mol Physiol 2009; 297: L238–L250.
    OpenUrlAbstract/FREE Full Text
    1. Savai R,
    2. Pullamsetti SS,
    3. Kolbe J, et al.
    Immune and inflammatory cell involvement in the pathology of idiopathic pulmonary arterial hypertension. Am J Respir Crit Care Med 2012; 186: 897–908.
    OpenUrlCrossRefPubMedWeb of Science
    1. Huertas A,
    2. Tu L,
    3. Thuillet R, et al.
    Leptin signalling system as a target for pulmonary arterial hypertension therapy. Eur Respir J 2015; 45: 1066–1080.
    OpenUrlAbstract/FREE Full Text
  27. ↵
    1. Zabini D,
    2. Crnkovic S,
    3. Xu H, et al.
    High-mobility group box-1 induces vascular remodelling processes via c-Jun activation. J Cell Mol Med 2015; 19: 1151–1161.
    OpenUrlCrossRefPubMed
  28. ↵
    1. Asosingh K,
    2. Farha S,
    3. Lichtin A, et al.
    Pulmonary vascular disease in mice xenografted with human BM progenitors from patients with pulmonary arterial hypertension. Blood 2012; 120: 1218–1227.
    OpenUrlAbstract/FREE Full Text
  29. ↵
    1. Foresta C,
    2. De Toni L,
    3. Di Mambro A, et al.
    The PDE5 inhibitor sildenafil increases circulating endothelial progenitor cells and CXCR4 expression. J Sex Med 2009; 6: 369–372.
    OpenUrlCrossRefPubMedWeb of Science
    1. Coffman L,
    2. Mooney C,
    3. Lim J, et al.
    Endothelin receptor-A is required for the recruitment of antitumor T cells and modulates chemotherapy induction of cancer stem cells. Cancer Biol Ther 2013; 14: 184–192.
    OpenUrlCrossRefPubMed
    1. Smadja DM,
    2. Levy M,
    3. Huang L, et al.
    Treprostinil indirectly regulates endothelial colony forming cell angiogenic properties by increasing VEGF-A produced by mesenchymal stem cells. Thromb Haemost 2015; 114: 735–747.
    OpenUrlCrossRefPubMed
    1. Song Y
    . Association study of circulating endothelial progenitor cells and plasma prostacyclin levels in pulmonary hypertension rats. Genet Mol Res 2014; 13: 438–444.
    OpenUrlCrossRefPubMed
  33. ↵
    1. Smadja DM,
    2. Mauge L,
    3. Gaussem P, et al.
    Treprostinil increases the number and angiogenic potential of endothelial progenitor cells in children with pulmonary hypertension. Angiogenesis 2011; 14: 17–27.
    OpenUrlCrossRefPubMed
  34. ↵
    1. Trosko JE
    . From adult stem cells to cancer stem cells: Oct-4 gene, cell–cell communication, and hormones during tumor promotion. Ann N Y Acad Sci 2006; 1089: 36–58.
    OpenUrlCrossRefPubMedWeb of Science
  35. ↵
    1. Schiavon M,
    2. Fadini GP,
    3. Lunardi F, et al.
    Increased tissue endothelial progenitor cells in end-stage lung diseases with pulmonary hypertension. J Heart Lung Transplant 2012; 31: 1025–1030.
    OpenUrlCrossRefPubMed
  36. ↵
    1. Germano D,
    2. Blyszczuk P,
    3. Valaperti A, et al.
    Prominin-1/CD133+ lung epithelial progenitors protect from bleomycin-induced pulmonary fibrosis. Am J Respir Crit Care Med 2009; 179: 939–949.
    OpenUrlCrossRefPubMedWeb of Science
  37. ↵
    1. Woo T,
    2. Okudela K,
    3. Mitsui H, et al.
    Prognostic value of CD133 expression in stage I lung adenocarcinomas. Int J Clin Exp Pathol 2010; 4: 32–42.
    OpenUrlPubMed
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CD133+ cells in pulmonary arterial hypertension
Vasile Foris, Gabor Kovacs, Leigh M. Marsh, Zoltán Bálint, Martin Tötsch, Alexander Avian, Philipp Douschan, Bahil Ghanim, Walter Klepetko, Andrea Olschewski, Horst Olschewski
European Respiratory Journal Aug 2016, 48 (2) 459-469; DOI: 10.1183/13993003.01523-2015
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