NHLRC2 expression is increased in idiopathic pulmonary fibrosis

BACKGROUND

Variants of NHL repeat-containing protein 2 (NHLRC2) have been associated with severe fibrotic interstitial lung disease in early childhood and NHLRC2 has been listed as a differentially expressed gene between rapidly and slowly progressing idiopathic pulmonary fibrosis (IPF) patients. However, its cell type-specific localization in human lung tissue is unknown. The aim of this study was to evaluate NHLRC2 mRNA and protein expression in different cell types of lung tissue samples and to investigate the effect of transforming growth factor (TGF)-β1 exposure on NHLRC2 expression in vitro.

METHODS

The NHLRC2 expression in lung tissue samples was studied by immunohistochemistry (50 IPF, 10 controls) and mRNA in situ hybridization (8 IPF, 3 controls). The immunohistochemical NHLRC2 expression was quantified with image analysis software and associated with the clinical and smoking data of the patients. NHLRC2 expression levels in primary stromal and small airway epithelial cell lines after exposure to TGF-β1 was measured by quantitative reverse transcription polymerase chain reaction and Western blot analysis.

RESULTS

NHLRC2 expression was detected especially in bronchiolar epithelial cells, type II pneumocytes and macrophages in normal lung. In the lungs of IPF patients, NHLRC2 was mainly expressed in hyperplastic alveolar epithelial cells lining fibroblast foci and honeycombs. NHLRC2 expression assessed by image analysis was higher in IPF compared to controls (p < 0.001). Ever-smokers had more prominent NHLRC2 staining than non-smokers (p = 0.037) among IPF patients. TGF-β1 exposure did not influence NHLRC2 levels in lung cell lines.

CONCLUSIONS

NHLRC2 expression was higher in IPF compared to controls being widely expressed in type II pneumocytes, macrophages, bronchiolar epithelium, and hyperplastic alveolar epithelium. Additionally, its expression was not regulated by the exposure to TGF-β1 in vitro. Further studies are needed to clarify the role of NHLRC2 in IPF.

Bronchoalveolar-Lavage-Derived Fibroblast Cell Lines Provide Tools for Investigating Various Interstitial Lung Diseases

Bronchoalveolar lavage (BAL) is an important diagnostic and research tool for the investigation of various lung diseases. In addition to inflammatory and epithelial cells, BAL fluid may contain a small number of stromal cells, such as fibroblasts. During the past 30 years, a number of research groups have cultured BAL-derived fibroblasts for several passages in vitro. In addition to fibroblasts, these cultures have been reported to contain fibrocytes, myofibroblasts, and stem cells. We aim to present a summary of studies that have cultured stromal cells from BAL fluid.

Nhlrc2 is crucial during mouse gastrulation

The loss of NHL repeat containing 2 (Nhlrc2) leads to early embryonic lethality in mice, but the exact timing is currently unknown. In this study, we determined the time of lethality for Nhlrc2 knockout (KO), C57BL/6NCrl‐Nhlrc2^{tm1a(KOMP)Wtsi}/Oulu, embryos and the in situ expression pattern of Nhlrc2 based on LacZ reporter gene expression during this period. Nhlrc2 KO preimplantation mouse embryos developed normally after in vitro fertilization. Embryonic stem (ES) cells established from KO blastocysts proliferated normally despite a complete loss of the NHLRC2 protein. Nhlrc2 KO embryos from timed matings implanted and were indistinguishable from their wildtype littermates on embryonic day (E) 6.5. On E7.5, Nhlrc2 KO embryo development was arrested, and on E8.5, only 6% of the genotyped embryos were homozygous for the Nhlrc2^{tm1a(KOMP)Wtsi} allele. Nhlrc2 KO E8.5 embryos showed limited embryonic or extraembryonic tissue differentiation and remained at the cylinder stage. Nhlrc2 expression was ubiquitous but strongest in the epiblast/ectoderm and extraembryonic ectoderm on E6.5 and E7.5. NHLRC2 is essential for early postimplantation development, and its loss leads to failed gastrulation and amniotic folding in mice. Future studies on the evolutionarily conserved NHLRC2 will provide new insights into the molecular pathways involved in the early steps of postimplantation development.

Decline in Mast Cell Density During Diffuse Alveolar Damage in Idiopathic Pulmonary Fibrosis

Mast cells (MCs) are known to be involved in the pathogenesis of idiopathic pulmonary fibrosis (IPF), although their role in acute exacerbations of IPF has not been investigated. The aims of the study were to evaluate the numbers of MCs in fibrotic and non-fibrotic areas of lung tissue specimens of idiopathic pulmonary fibrosis (IPF) patients with or without an acute exacerbation of IPF, and to correlate the MC density with clinical parameters. MCs of IPF patients were quantified from surgical lung biopsy (SLB) specimens (n = 47) and lung tissue specimens taken at autopsy (n = 7). MC density was higher in the fibrotic areas of lung tissue compared with spared alveolar areas or in controls. Female gender, low diffusion capacity for carbon monoxide, diffuse alveolar damage, and smoking were associated with a low MC density. MC densities of fibrotic areas had declined significantly in five subjects in whom both SLB in the stable phase and autopsy after an acute exacerbation of IPF had been performed. There were no correlations of MC densities with survival time or future acute exacerbations. The MC density in fibrotic areas was associated with several clinical parameters. An acute exacerbation of IPF was associated with a significant decline in MC counts. Further investigations will be needed to clarify the role of these cells in IPF and in the pathogenesis of acute exacerbation as this may help to identify some potential targets for medical treatment for this serious disease.

Moderate hypothermia with remote ischaemic preconditioning improves cerebral protection compared to deep hypothermia: a study using a surviving porcine model

OBJECTIVES

The optimal temperature management of hypothermic circulatory arrest is still controversial. Moderate hypothermia preserves cerebral autoregulation and shortens cardiopulmonary bypass (CPB) duration. However, moderate hypothermia alone has inferior organ protection to deep hypothermia, so adjuncts that increase the ischaemic tolerance are needed. Thus, we hypothesized that a combination of remote ischaemic preconditioning (RIPC) and moderate hypothermia would be superior to deep hypothermia alone.

METHODS

Sixteen pigs were randomized to either RIPC or control groups (8 + 8). The RIPC group underwent 4 cycles of transient hind limb ischaemia. The RIPC group underwent cooling with CPB to 24°C, and the control group underwent cooling with CPB to 18°C, followed by a 30-min arrest period and subsequent rewarming to 36°C. Measurements of cerebral metabolism were made from sagittal sinus blood samples and common carotid artery blood flow. The permissible periods of hypothermic circulatory arrest were calculated based on these measurements. Neurological recovery was evaluated daily during a 7-day follow-up, and the brain was harvested for histopathological analysis.

RESULTS

Six pigs in the RIPC group reached normal neurological function, but none in the control group reached normal neurological function (P = 0.007). The composite neurological score of all postoperative days was higher in the RIPC group than in the control group [55 (52-58) vs 45 (39-51), P = 0.026]. At 24°C, the estimated permissible periods of hypothermic circulatory arrest were 21 (17-25) min in the RIPC group and 11 (9-13) min in the control group (P = 0.007).

CONCLUSIONS

RIPC combined with moderate hypothermia provides superior cerebral protection.

Women with polycystic ovary syndrome present with altered endometrial expression of stanniocalcin-1†

Stanniocalcin-1 (STC-1) is a pro-survival factor that protects tissues against stressors, such as hypoxia and inflammation. STC-1 is co-expressed with the endometrial receptivity markers, and recently endometrial STC-1 was reported to be dysregulated in endometriosis, a condition linked with endometrial progesterone resistance and inflammation. These features are also common in the endometrium in women with polycystic ovary syndrome (PCOS), the most common endocrine disorder in women. Given that women with PCOS present with subfertility, pregnancy complications, and increased risk for endometrial cancer, we investigated endometrial STC-1 expression in affected women. Endometrial biopsy samples were obtained from women with PCOS and controls, including samples from overweight/obese women with PCOS before and after a 3-month lifestyle intervention. A total of 98 PCOS and 85 control samples were used in immunohistochemistry, reverse-transcription polymerase chain reaction, or in vitro cell culture. STC-1 expression was analyzed at different cycle phases and in endometrial stromal cells (eSCs) after steroid hormone exposure. The eSCs were also challenged with 8-bromo-cAMP and hypoxia for STC-1 expression. The findings indicate that STC-1 expression is not steroid hormone mediated although secretory-phase STC-1 expression was blunted in PCOS. Lower expression seems to be related to attenuated STC-1 response to stressors in PCOS eSCs, shown as downregulation of protein kinase A activity. The 3-month lifestyle intervention did not restore STC-1 expression in PCOS endometrium. More studies are warranted to further elucidate the mechanisms behind the altered endometrial STC-1 expression and rescue mechanism in the PCOS endometrium.

Extracellular matrix proteins produced by stromal cells in idiopathic pulmonary fibrosis and lung adenocarcinoma

Idiopathic pulmonary fibrosis (IPF) and lung cancer share common risk factors, epigenetic and genetic alterations, the activation of similar signaling pathways and poor survival. The aim of this study was to examine the gene expression profiles of stromal cells from patients with IPF and lung adenocarcinoma (ADC) as well as from normal lung. The gene expression levels of cultured stromal cells derived from non-smoking patients with ADC from the tumor (n = 4) and the corresponding normal lung (n = 4) as well as from patients with IPF (n = 4) were investigated with Affymetrix microarrays. The expression of collagen type IV alpha 1 chain, periostin as well as matrix metalloproteinase-1 and -3 in stromal cells and lung tissues were examined with quantitative real-time reverse transcriptase polymerase chain reaction and immunohistochemistry, respectively. Twenty genes were similarly up- or down-regulated in IPF and ADC compared to control, while most of the altered genes in IPF and ADC were differently expressed, including several extracellular matrix genes. Collagen type IV alpha 1 chain as well as matrix metalloproteinases-1 and -3 were differentially expressed in IPF compared to ADC. Periostin was up-regulated in both IPF and ADC in comparison to control. All studied factors were localized by immunohistochemistry in stromal cells within fibroblast foci in IPF and stroma of ADC. Despite the similarities found in gene expressions of IPF and ADC, several differences were also detected, suggesting that the molecular changes occurring in these two lung illnesses are somewhat different.

Smoking effect on the ultrastructural properties of cultured lung myofibroblasts

This study aimed at an ultrastructural characterization of myofibroblasts cultured from different compartments of lung from never-smokers and smokers with or without COPD. In addition, we evaluated the expression of alpha smooth muscle actin (α-SMA), a marker for myofibroblasts, and contractile properties. Stromal cells cultured from central and corresponding peripheral or only from peripheral lung of never-smokers, smokers without COPD and COPD patients were analyzed by transmission electron microscopy (TEM), immunoelectron microscopy (IEM), Western analysis and/or by collagen gel contraction assay. TEM revealed that myofibroblasts cultured from smokers and COPD had less prominent intracellular actin filaments. We also examined fibronexus (FNX), which is a typical ultrastructural feature of myofibroblasts, and observed that patients with COPD more frequently had tandem-like FNX as compared to other samples. Western analysis showed that the samples derived from the central lung of never-smokers expressed higher levels of α-SMA than those of smokers and COPD patients. Cells from central lung were less contractile than those from peripheral lung. We conclude that myofibroblasts have variable ultrastructural and functional properties based on their localization in the lung and, moreover, these properties are affected by both smoking history and COPD.

Safety of direct true lumen cannulation after venous exsanguination: a study in a surviving porcine model†

OBJECTIVES

Type A aortic dissection requires immediate surgery. Traditional cannulation methods such as the central aortic cannulation with the Seldinger technique and axillary cannulation are primary choices. Yet in the presence of tamponade or severe cardiogenic shock, these can be too time-consuming to complete. Direct true lumen cannulation after venous exsanguination not only avoids this issue but also leads to transient global ischaemia. We studied the safety of direct true lumen cannulation from the aspect of global ischaemia in a surviving porcine model.

METHODS

Twelve pigs were randomized to either control or intervention groups (6 + 6). The intervention group underwent simulated direct true lumen cannulation by exsanguination and circulatory arrest for 5 min at 35°C before cardiopulmonary bypass (CPB). Both groups underwent CPB cooling to 25°C followed by a 25-min arrest period and subsequent warming to 36°C. Neuron-specific enolase levels were measured at 6 time-points from blood samples. Near-infrared spectroscopy was used to determine brain oxygenation. The neurological recovery was evaluated daily during a 7-day follow-up, and the brain was harvested for a histopathological analysis after euthanization.

RESULTS

All pigs recovered their normal neurological behaviour. The neurobehavioural total score on postoperative day 2 reached borderline statistical significance, thus favouring the intervention group [(9 (8.75-9) vs 6.5 (5.5-9), P = 0.06]. Near-infrared spectroscopy values and neuron-specific enolase levels slightly favoured the control group during the cooling period, but the difference was not clinically significant. The histopathological analysis showed no difference between the groups.

CONCLUSIONS

A 5-min period of normothermic global ischaemia before CPB does not impair the neurological outcome following hypothermic circulatory arrest in a surviving porcine model.

Biallelic mutations in human NHLRC2 enhance myofibroblast differentiation in FINCA disease

The development of tissue fibrosis is complex and at the present time, not fully understood. Fibrosis, neurodegeneration and cerebral angiomatosis (FINCA disease) have been described in patients with mutations in NHL repeat-containing protein 2 (NHLRC2). However, the molecular functions of NHLRC2 are uncharacterized. Herein, we identified putative interacting partners for NHLRC2 using proximity-labeling mass spectrometry. We also investigated the function of NHLRC2 using immortalized cells cultured from skin biopsies of FINCA patients and normal fibroblasts with NHLRC2 knock-down and NHLRC2 overexpressing gene modifications. Transmission electron microscopy analysis of immortalized cell cultures from three FINCA patients demonstrated multilamellar bodies and distinctly organized vimentin filaments. Additionally, two of three cultures derived from patient skin biopsies contained cells that exhibited features characteristic of myofibroblasts. Altogether, the data presented in this study show for the first time that NHLRC2 is involved in cellular organization through regulation of the cytoskeleton and vesicle transport. We conclude that compound heterozygous p.Asp148Tyr and p.Arg201GlyfsTer6 mutations in NHLRC2 lead to severe tissue fibrosis in humans by enhancing the differentiation of fibroblasts to myofibroblasts.

Two novel direct SPIO labels and in vivo MRI detection of labeled cells after acute myocardial infarct

BACKGROUND

Acute myocardial infarction (AMI) is a leading cause of morbidity and mortality worldwide. Cellular decay due hypoxia requires rapid and validated methods for possible therapeutic cell transplantation.

PURPOSE

To develop direct and rapid superparamagnetic iron oxide (SPIO) cell label for a large-animal model and to assess in vivo cell targeting by magnetic resonance imaging (MRI) in an experimental AMI model.

MATERIAL AND METHODS

Bone marrow mononuclear cells (BMMNCs) were labeled with SPIO particles using two novel direct labeling methods (rotating incubation method and electroporation). Labeling, iron incorporation in cells and label distribution, cellular viability, and proliferation were validated in vitro. An AMI porcine model was used to evaluate the direct labeling method (rotating incubation method) by examining targeting of labeled BMMNCs using MRI and histology.

RESULTS

Labeling (1 h) did not alter either cellular differentiation potential or viability of cells in vitro. Cellular relaxation values at 9.4 T correlated with label concentration and MRI at 1.5 T showing 89 ± 4% signal reduction compared with non-labeled cells in vitro. In vivo, a high spatial correlation between MRI and histology was observed. The extent of macroscopic pathological myocardial changes (hemorrhage) correlated with altered function detected on MRI.

CONCLUSION

We demonstrated two novel direct SPIO labeling methods and demonstrated the feasibility of clinical MRI for monitoring targeting of the labeled cells in animal models of AMI.

Niche matters: The comparison between bone marrow stem cells and endometrial stem cells and stromal fibroblasts reveal distinct migration and cytokine profiles in response to inflammatory stimulus

Objective

Intrinsic inflammatory characteristics play a pivotal role in stem cell recruitment and homing through migration where the subsequent change in niche has been shown to alter these characteristics. The bone marrow mesenchymal stem cells (bmMSCs) have been demonstrated to migrate to the endometrium contributing to the stem cell reservoir and regeneration of endometrial tissue. Thus, the aim of the present study was to compare the inflammation-driven migration and cytokine secretion profile of human bmMSCs to endometrial mesenchymal stem cells (eMSCs) and endometrial fibroblasts (eSFs).

Materials and methods

The bmMSCs were isolated from bone marrow aspirates through culturing, whereas eMSCs and eSFs were FACS-isolated. All cell types were tested for their surface marker, proliferation profiles and migration properties towards serum and inflammatory attractants. The cytokine/chemokine secretion profile of 35 targets was analysed in each cell type at basal level along with lipopolysaccharide (LPS)-induced state.

Results

Both stem cell types, bmMSCs and eMSCs, presented with similar stem cell surface marker profiles as well as possessed high proliferation and migration potential compared to eSFs. In multiplex assays, the secretion of 16 cytokine targets was detected and LPS stimulation expanded the cytokine secretion pattern by triggering the secretion of several targets. The bmMSCs exhibited higher cytokine secretion of vascular endothelial growth factor (VEGF)-A, stromal cell-derived factor-1 alpha (SDF)-1α, interleukin-1 receptor antagonist (IL-1RA), IL-6, interferon-gamma inducible protein (IP)-10, monocyte chemoattractant protein (MCP)-1, macrophage inflammatory protein (MIP)1α and RANTES compared to eMSCs and/or eSFs after stimulation with LPS. The basal IL-8 secretion was higher in both endometrial cell types compared to bmMSCs.

Conclusion

Our results highlight that similar to bmMSCs, the eMSCs possess high migration activity while the differentiation process towards stromal fibroblasts seemed to result in loss of stem cell surface markers, minimal migration activity and a subtler cytokine profile likely contributing to normal endometrial function.

Mucin-1 correlates with survival, smoking status, and growth patterns in lung adenocarcinoma

Mucin-1 (MUC1) affects cancer progression in lung adenocarcinoma, and its aberrant expression pattern has been correlated with poor tumor differentiation and impaired prognosis. In this study, the immunohistochemical expression of MUC1 and Mucin-4 (MUC4) was analyzed in a series of 106 surgically operated stage I-IV pulmonary adenocarcinomas. MUC1 immunohistochemistry was evaluated according to the Nagai classification, and the immunohistochemical profile of the tumors was correlated with detailed clinical and histological data. The effect of cigarette smoke on MUC1 expression in lung cancer cell lines was examined using real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR) and immunoelectron microscopy (IEM). In contrast to the normal apical localization of MUC1, a basolateral and cytoplasmic (depolarized) MUC1 expression pattern was frequently encountered in the high-grade subtypes, i.e., solid predominant adenocarcinoma and the cribriform variant of acinar predominant adenocarcinoma (p < 0.001), and was rarely observed in tumors containing a non-predominant lepidic component (p < 0.001). Furthermore, the altered staining pattern of MUC1 correlated with stage (p = 0.002), reduced overall survival (p = 0.031), and was associated with smoking (p < 0.001). When H1650 adenocarcinoma cells were exposed to cigarette smoke and analyzed by RT-qPCR and IEM, the levels of the MUC1 transcript and protein were elevated (p = 0.042). In conclusion, MUC1 participates in the pathogenesis of lung adenocarcinoma and associates with smoking both in vitro and in vivo. In lung adenocarcinoma, depolarized MUC1 protein expression correlated with histological growth patterns, stage, and patient outcome.

Tankyrase inhibition aggravates kidney injury in the absence of CD2AP

Inappropriate activation of the Wnt/β-catenin pathway has been indicated in podocyte dysfunction and injury, and shown to contribute to the development and progression of nephropathy. Tankyrases, multifunctional poly(ADP-ribose) polymerase (PARP) superfamily members with features of both signaling and cytoskeletal proteins, antagonize Wnt/β-catenin signaling. We found that tankyrases interact with CD2-associated protein (CD2AP), a protein essential for kidney ultrafiltration as CD2AP-knockout (CD2AP−/−) mice die of kidney failure at the age of 6–7 weeks. We further observed that tankyrase-mediated total poly-(ADP-ribosyl)ation (PARylation), a post-translational modification implicated in kidney injury, was increased in mouse kidneys and cultured podocytes in the absence of CD2AP. The data revealed increased activity of β-catenin, and upregulation of lymphoid enhancer factor 1 (LEF1) (mediator of Wnt/β-catenin pathway) and fibronectin (downstream target of Wnt/β-catenin) in CD2AP−/− podocytes. Total PARylation and active β-catenin were reduced in CD2AP−/− podocytes by tankyrase inhibitor XAV939 treatment. However, instead of ameliorating podocyte injury, XAV939 further upregulated LEF1, failed to downregulate fibronectin and induced plasminogen activator inhibitor-1 (PAI-1) that associates with podocyte injury. In zebrafish, administration of XAV939 to CD2AP-depleted larvae aggravated kidney injury and increased mortality. Collectively, the data reveal sustained activation of the Wnt/β-catenin pathway in CD2AP−/− podocytes, contributing to podocyte injury. However, we observed that inhibition of the PARylation activity of tankyrases in the absence of CD2AP was deleterious to kidney function. This indicates that balance of the PARylation activity of tankyrases, maintained by CD2AP, is essential for normal kidney function. Furthermore, the data reveal that careful contemplation is required when targeting Wnt/β-catenin pathway to treat proteinuric kidney diseases associated with impaired CD2AP.

Breast cancer carcinoma-associated fibroblasts differ from breast fibroblasts in immunological and extracellular matrix regulating pathways

Tumor stroma has been recently shown to play a crucial role in the development of breast cancer. Since the origin of the stromal cells in the tumor is unknown, we have examined differences and similarities between three stromal cell types of mesenchymal origin, namely carcinoma associated fibroblasts from breast tumor (CAFs), fibroblasts from normal breast area (NFs) and bone marrow derived mesenchymal stromal cells (MSCs). In a microarray analysis, immunological, developmental and extracellular matrix -related pathways were over-represented in CAFs when compared to NFs (p<0.001). Under hypoxic conditions, the expression levels of pyruvate dehydrogenase kinase-1 (PDK1) and pyruvate dehydrogenase kinase-4 (PDK4) were lower in CAFs when compared to NFs (fold changes 0.6 and 0.4, respectively). In normoxia, when compared to NFs, CAFs displayed increased expression of glucose transporter 1 (GLUT-1) and PDK1 (fold changes 1.5 and 1.3, respectively). With respect to the assessed surface markers, only CD105 was expressed differently in MSCs when compared to fibroblasts, being more often expressed on MSCs. Cells with myofibroblast features were present in both NF and CAF samples. We conclude, that CAFs differ distinctly from NFs at the gene expression level, this hypothesis was also tested in silico for other available gene expression data.

Podocyte apoptosis is prevented by blocking the Toll-like receptor pathway

High serum lipopolysaccharide (LPS) activity in normoalbuminuric patients with type 1 diabetes (T1D) predicts the progression of diabetic nephropathy (DN), but the mechanisms behind this remain unclear. We observed that treatment of cultured human podocytes with sera from normoalbuminuric T1D patients with high LPS activity downregulated 3-phosphoinositide-dependent kinase-1 (PDK1), an activator of the Akt cell survival pathway, and induced apoptosis. Knockdown of PDK1 in cultured human podocytes inhibited antiapoptotic Akt pathway, stimulated proapoptotic p38 MAPK pathway, and increased apoptosis demonstrating an antiapoptotic role for PDK1 in podocytes. Interestingly, PDK1 was downregulated in the glomeruli of diabetic rats and patients with type 2 diabetes before the onset of proteinuria, further suggesting that reduced expression of PDK1 associates with podocyte injury and development of DN. Treatment of podocytes in vitro and mice in vivo with LPS reduced PDK1 expression and induced apoptosis, which were prevented by inhibiting the Toll-like receptor (TLR) signaling pathway with the immunomodulatory agent GIT27. Our data show that LPS downregulates the cell survival factor PDK1 and induces podocyte apoptosis, and that blocking the TLR pathway with GIT27 may provide a non-nephrotoxic means to prevent the progression of DN.

High number of transplanted stem cells improves myocardial recovery after AMI in a porcine model

OBJECTIVE

The clinical data considering the bone marrow mononuclear cell (BMMNC) therapy in treatment for acute myocardial infarction (AMI) are controversial and the mechanisms remain unknown. Our objective was to study the cardiac function and changes in cytokine levels after administration of BMMNC in experimental AMI model.

DESIGN

Unlabeled or Super-Paramagnetic-Iron-Oxide-labeled BMMNCs or saline was injected into myocardium of 31 pigs after circumflex artery occlusion. Ejection fraction (EF) was measured preoperatively, postoperatively and at 21 days by echocardiography. Cardiac MRI was performed postoperatively and after 21 days in 7 BMMNC animals. Serum cytokine levels were measured at baseline, 24 h and 21 days. Cellular homing was evaluated comparing MRI and histology.

RESULTS

From baseline to 21 days EF decreased less in BMMNC group (EF mean control -19 SD 12 vs. BMMNC -4 SD 15 percentage points p = 0.02). Cytokine concentrations showed high variability between the animals. MRI correlated with histology in cell detection and revealed BMMNCs in the infarction area. By MRI, EF improved 11 percentage points. The improvement in EF was associated with the number of transplanted BMMNCs detected in the myocardium.

CONCLUSION

BMMNC injection after AMI improved cardiac function. Quantity of transplanted BMMNCs correlated with the improvement in cardiac function after AMI.

Novel, fast-processed crystalline and amorphous manganese oxide nanoparticles for stem cell labeling

MnO(x) nanostructures were developed to be utilized as contrast agents for cellular labeling and tracking by MR-imaging.

Slug is associated with poor survival in squamous cell carcinoma of the lung

We investigated the expression of slug in a large set of lung squamous and adenocarcinomas to determine common or dissimilar features in its expression in these two most common forms of lung cancer. To investigate slug related tumor spread we studied the expression of vimentin, claudin 1, MMP2 and MMP9 in these tumors and their relation to slug. Addition, cell invasion assays, mRNA analysis and zymographic tests were performed to study epitheliomesenchymal transition (EMT) related changes in slug blocked lung cell lines. According to the results slug expression did not significantly differ between squamous (SCC) and adenocarcinoma (AC) (P = 0.25). In SCC, slug associated with vimentin (P = 0.016). In AC, claudin 1 associated with MMP2 (P = 0.037). In SCC slug expression had a poor prognositic significance (P = 0.006) and it had independent prognostic value (P = 0.037). In AC MMP2 had a worsening impact on survival (P = 0.021) and it had independent prognostic value (P = 0.002). In cell invasion assays, slug knockdown inhibited the invasion and migration of BEAS-2B, SK-LU1 and SK-MES1 cell lines. The mRNA expression of claudin 1 was downregulated in SK-LU1 cell line. Both tumor cell lines expressed MMP2 and in SK-MES1 slug inhibited line MMP2 appeared to decrease. The results show that slug associated EMT is more pronounced in lung SCC than AC. Slug associated with vimentin in SCC and had an independent prognostic value in this tumor type. Forced slug inhibition might be one putative way of treatment of SCC of the lung.

Cell surface structures influence lung clearance rate of systemically infused mesenchymal stromal cells

The promising clinical effects of mesenchymal stromal/stem cells (MSCs) rely especially on paracrine and nonimmunogenic mechanisms. Delivery routes are essential for the efficacy of cell therapy and systemic delivery by infusion is the obvious goal for many forms of MSC therapy. Lung adhesion of MSCs might, however, be a major obstacle yet to overcome. Current knowledge does not allow us to make sound conclusions whether MSC lung entrapment is harmful or beneficial, and thus we wanted to explore MSC lung adhesion in greater detail. We found a striking difference in the lung clearance rate of systemically infused MSCs derived from two different clinical sources, namely bone marrow (BM-MSCs) and umbilical cord blood (UCB-MSCs). The BM-MSCs and UCB-MSCs used in this study differed in cell size, but our results also indicated other mechanisms behind the lung adherence. A detailed analysis of the cell surface profiles revealed differences in the expression of relevant adhesion molecules. The UCB-MSCs had higher expression levels of α4 integrin (CD49d, VLA-4), α6 integrin (CD49f, VLA-6), and the hepatocyte growth factor receptor (c-Met) and a higher general fucosylation level. Strikingly, the level of CD49d and CD49f expression could be functionally linked with the lung clearance rate. Additionally, we saw a possible link between MSC lung adherence and higher fibronectin expression and we show that the expression of fibronectin increases with MSC culture confluence. Future studies should aim at developing methods of transiently modifying the cell surface structures in order to improve the delivery of therapeutic cells.

Transient proteolytic modification of mesenchymal stromal cells increases lung clearance rate and targeting to injured tissue

Systemic infusion of therapeutic cells would be the most practical and least invasive method of administration in many cellular therapies. One of the main obstacles especially in intravenous delivery of cells is a massive cell retention in the lungs, which impairs homing to the target tissue and may decrease the therapeutic outcome. In this study we showed that an alternative cell detachment of mesenchymal stromal/stem cells (MSCs) with pronase instead of trypsin significantly accelerated the lung clearance of the cells and, importantly, increased their targeting to an area of injury. Cell detachment with pronase transiently altered the MSC surface protein profile without compromising cell viability, multipotent cell characteristics, or immunomodulative and angiogenic potential. The transient modification of the cell surface protein profile was sufficient to produce effective changes in cell rolling behavior in vitro and, importantly, in the in vivo biodistribution of the cells in mouse, rat, and porcine models. In conclusion, pronase detachment could be used as a method to improve the MSC lung clearance and targeting in vivo. This may have a major impact on the bioavailability of MSCs in future therapeutic regimes.

The mechanism of action of induced membranes in bone repair

BACKGROUND

Inducement of foreign-body granulation tissue is a relatively novel therapeutic modality in bone repair. A two-stage bone reconstruction method, known as the Masquelet technique, combines inducement of a granulation tissue membrane and subsequent bone autografting as a biphasic technique allowing reconstruction of large bone defects. In light of their already well-characterized osteogenesis-improving capabilities in animals, we performed this translational study to investigate these membranes in patients.

METHODS

Fourteen patients with complicated fractures and bone defects were randomly selected for this study. Biopsy samples of foreign-body-induced membranes were collected at different time points during scheduled surgical procedures. The membranes were co-cultured with mesenchymal stromal cells, and differentiation into the osteoblastic lineage was assessed by measuring alkaline phosphatase activity, aminoterminal propeptide of type-I procollagen (PINP) production, and Ca2+ concentration. Histological characteristics were evaluated with image analysis. Quantitative reverse transcription polymerase chain reaction was used to measure vascular endothelial growth factor (VEGF), interleukin-6 (IL-6), and type-I collagen (Col-1) expression.

RESULTS

The induced membranes were characterized histologically by maturating vascularized fibrous tissue. The vascularization was greatest in one-month-old samples and decreased to <60% in three-month-old samples. One-month-old membrane samples had the highest expression of VEGF, IL-6, and Col-1, whereas two-month-old membranes expressed <40% of the levels of the one-month-old membranes. Specific alkaline phosphatase activity, PINP production, and Ca2+ concentration were increased in co-cultures when a membrane sample was present. In cultures of one-month-old membranes, PINP production was more than two times and Ca2+ deposition was four times higher than that in cultures of two-month-old membranes.

CONCLUSIONS

The induced membranes have osteogenesis-improving capabilities. These capabilities, however, appear to decrease over time. We speculate that the optimal time for performing second-stage surgery may be within a month after implantation of foreign material.

Activity of mesenchymal stem cells in a nonperfused cardiac explant model

Stem cell therapy represents a potential novel additional therapy for acute myocardial infarction. Cardiac applications of stem cell therapy are now undergoing clinical trials though many properties, including localization, possible adhesion, and infiltration of the injected stem cells in the myocardium, have not been studied in detail even in vitro. To study these mechanisms in a controlled microenvironment, we developed a model where mesenchymal stem cells (MSCs) were transported into live, cultured cardiac explants for further co-culture. About 10×10(3) porcine MSCs were injected into freshly excised and isolated cardiac explants of the pig. The explants were present in the culture medium for up to 7 days, with the time course of viability of the myocardial tissue, and the migration and the localization of the injected MSCs were analyzed with histological and immunohistological stainings. The myocyte structure was observed to be well preserved, and proliferation of capillaries and myofibroblasts was detected at the explant periphery. There were injected MSCs localized in the capillaries and in contact with the endothelial cells. The migration range and the number of adherent MSCs increased over time, suggesting active movement of MSCs in the explant. Our results suggest that this cardiac explant culture model is a feasible method for studying the effects of stem cells in the myocardium in vitro.

Monitoring mitochondrial inner membrane potential for detecting early changes in viability of bacterium-infected human bone marrow-derived mesenchymal stem cells

Introduction

One of the most challenging safety issues in the manufacture of cell based medicinal products is the control of microbial risk as cell-based products cannot undergo terminal sterilization. Accordingly, sensitive and reliable methods for detection of microbial contamination are called for. As mitochondrial function has been shown to correlate with the viability and functionality of human mesenchymal stem cells (hMSCs) we have studied the use of a mitochondrial inner membrane potential sensitive dye for detecting changes in the function of mitochondria following infection by bacteria.

Methods

The effect of bacterial contamination on the viability of bone marrow-derived mesenchymal stem cells (BMMSCs) was studied. BMMSC lines were infected with three different bacterial species, namely two strains of Pseudomonas aeruginosa, three strains of Staphylococcus aureus, and three strains of Staphylococcus epidermidis. The changes in viability of the BMMSCs after bacterial infection were studied by staining with Trypan blue, by morphological analysis and by monitoring of the mitochondrial inner membrane potential.

Results

Microscopy and viability assessment by Trypan blue staining showed that even the lowest bacterial inocula caused total dissipation of BMMSCs within 24 hours of infection, similar to the effects seen with bacterial loads which were several magnitudes higher. The first significant signs of damage induced by the pathogens became evident after 6 hours of infection. Early changes in mitochondrial inner membrane potential of BMMSCs were evident after 4 hours of infection even though no visible changes in viability of the BMMSCs could be seen.

Conclusions

Even low levels of bacterial contamination can cause a significant change in the viability of BMMSCs. Moreover, monitoring the depolarization of the mitochondrial inner membrane potential may provide a rapid tool for early detection of cellular damage induced by microbial infection. Accordingly, mitochondrial analyses offer sensitive tools for quality control and monitoring of safety and efficacy of cellular therapy products.

INPPL1 is associated with the metabolic syndrome in men with Type 1 diabetes, but not with diabetic nephropathy

AIMS

The metabolic syndrome is a frequent phenomenon in people with Type 1 diabetes and is associated with diabetic nephropathy. The aim of this study was to investigate if the INPPL1 (inositol polyphosphate phosphatase-like 1) gene encoding lipid phosphatase SHIP2 is associated with the metabolic syndrome and diabetic nephropathy in Finnish people with Type 1 diabetes.

METHODS

Participants were selected from the FinnDiane study for this cross-sectional study. The individuals were divided into controls without the metabolic syndrome (n = 1074) and cases with the metabolic syndrome (n = 1328), or into groups based upon their albumin excretion rate. Nine single-nucleotide polymorphisms covering the INPPL1 gene +/- 20 kb were genotyped. The associations between the single-nucleotide polymorphisms and outcome variables were analysed with the χ(2) test and logistic regression.

RESULTS

Two INPPL1 single-nucleotide polymorphisms, rs2276048 (silent mutation) and rs2276047 (intronic), were associated with the metabolic syndrome in men with odds ratios of 0.23 (95% CI 0.11-0.45, P = 2.1 × 10(-5) ), and 0.37 (0.21-0.65, P = 0.001), adjusted for age, duration of diabetes and history of smoking. When both sexes were included, these associations were less significant. No association between the genotyped single-nucleotide polymorphisms and diabetic nephropathy was observed.

CONCLUSIONS

INPPL1 gene variants may contribute to susceptibility to the metabolic syndrome in men with Type 1 diabetes, but not to diabetic nephropathy.

Portal vein cytokines in the early phase of acute experimental oedematous and necrotizing porcine pancreatitis

OBJECTIVE

Cytokines initiate and modify systemic inflammatory response in early acute pancreatitis. The aim of this study was to analyze which cytokines are released from the pancreas to portal venous blood in the early phase of acute experimental necrotizing and oedematous pancreatitis and which of those cytokines are correlated with the more severe form of the disease.

MATERIAL AND METHODS

Fifteen pigs were randomized to develop mild oedematous pancreatitis (n = 5, saline infusion to pancreatic duct), severe necrotizing pancreatitis (n = 5, taurocholic acid infusion) along with a control group (n = 5). Arterial and venous blood samples were drawn and cytokine levels were measured from portal vein blood at 0, 120, 240 and 360 min after the induction of pancreatitis. Tissue samples from the pancreas were harvested at 0 and 360 min.

RESULTS

White blood cell count increased in necrotizing pancreatitis and the control group. The amount of neutrophils increased (p < 0.001) and the lymphocyte and eosinophil counts decreased in all groups (p < 0.001, p < 0.001). The monocyte count, as well as PDGF and IL-6 concentrations, increased only in necrotizing pancreatitis. IL-8 and eotaxin increased both in oedematous and necrotizing pancreatitis. MCP-1 increased in all groups. IL-9, IL-4, MIP-1α, IFN- γ concentrations did not change. Eotaxin and MCP-1 plasma levels from a previous series between portal venous and pulmonary arterial blood were not significantly different.

CONCLUSIONS

The initial inflammatory process was diverse in oedematous and necrotizing pancreatitis. Increased monocyte count in combination with elevated PDGF and IL-6 are characteristic of necrotizing pancreatitis in our model.

Inhibition of cytokine secretion from adipocytes by 1,25-dihydroxyvitamin D₃ via the NF-κB pathway

Adipose tissue inflammation is an important pathological process in obese people, associated with diabetes and cardiovascular disease. We hypothesized that 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] inhibits cytokine secretion from adipocytes via direct inhibition of transcription factor nuclear factor-κB (NF-κB). We utilized two different human models. Bone marrow-derived human mesenchymal stromal cells (hMSCs) differentiated into adipocytes, and adipocytes isolated from biopsies stimulated with lipopolysaccharide (LPS) were treated with or without 1,25(OH)(2)D(3). Expression and secretion of interleukin-6 (IL-6) were measured by quantitative RT-PCR analysis and ELISA. Assessment of NF-κB nuclear translocation, DNA binding activity was performed by immunofluorescence (IF) and electrophoretic mobility assay (EMSA). Inhibitor κB (IκB) and its phosphorylation were detected by Western blot (WB) analysis. Simultaneous 1,25(OH)(2)D(3) cotreatment significantly reduced LPS-stimulated (10 ng/ml) IL-6 secretion dose dependently by 15% at 10(-10) M and 26% at 10(-7) M (P<0.05) in hMSCs, while preincubation with 1,25(OH)(2)D(3) (10(-7) M) for 24 h reduced IL-6 secretion by 24 and 35% (P<0.001) and mRNA levels by 34 and 30% (P<0.05) in hMSCs and isolated adipocytes, respectively. 1,25(OH)(2)D(3) suppressed LPS-stimulated IκB phosphorylation-mediated NF-κB translocation into the nucleus were evident from WB, IF, and EMSA. 1,25(OH)(2)D(3) inhibits LPS-stimulated IL-6 secretion in two human adipocyte models via interference with NF-κB signaling.

Tumor tissue inhibitor of metalloproteinases-1 (TIMP-1) in hormone-independent breast cancer might originate in stromal cells, and improves stratification of prognosis together with nodal status

Tissue inhibitor of metalloproteinases-1 (TIMP-1) is shown to be a potential marker for poor prognosis in breast cancer, but the biology of TIMP-1 is only partially understood. In this study, TIMP-1 production was studied in a co-culture model of hormone-independent breast cancer cell lines and mesenchymal stem cells mimicking the stromal components of the tumor. In addition, the prognostic value of TIMP-1 was histologically evaluated in a clinical material of 168 patients with hormone-independent breast tumors. The hormone-independent breast cancer (BC) cell lines MDA-MB-231, M4A4 and NM2C5 did not produce TIMP-1 protein in measureable quantities. Six tested primary mesenchymal stem cell lines all produced TIMP-1. Co-culturing of mesenchymal stem cells and breast cancer cells resulted in positive immunocytochemical diffuse staining for TIMP-1 for both cell types. Culturing breast cancer cells with MSC-conditioned media resulted in a positive cytoplasmic immunoreactivity for TIMP-1, and TIMP-1 protein concentration in cell lysates increased 2.7-fold (range 1.1-4.7). The TIMP-1 mRNA levels remained unaffected in BC cells. This might suggest that breast cancer cells can take up TIMP-1 produced by stromal cells and are thus displaying cellular immunoreactivity. In addition, TIMP-1 was shown to improve stratification of prognosis in clinical material.

CD200 positive human mesenchymal stem cells suppress TNF-alpha secretion from CD200 receptor positive macrophage-like cells

Human mesenchymal stem cells (hMSCs) display immunosuppressive properties in vitro and the potential has also been transferred successfully to clinical trials for treatment of autoimmune diseases. OX-2 (CD200), a member of the immunoglobulin superfamily, is widely expressed in several tissues and has recently been found from hMSCs. The CD200 receptor (CD200R) occurs only in myeloid-lineage cells. The CD200-CD200R is involved in down-regulation of several immune cells, especially macrophages. The present study on 20 hMSC lines shows that the CD200 expression pattern varied from high (CD200Hi) to medium (CD200Me) and low (CD200Lo) in bone marrow-derived mesenchymal stem cell (BMMSC) lines, whereas umbilical cord blood derived mesenchymal stem cells (UCBMSCs) were constantly negative for CD200. The role of the CD200-CD200R axis in BMMSCs mediated immunosuppression was studied using THP-1 human macrophages. Interestingly, hMSCs showed greater inhibition of TNF-α secretion in co-cultures with IFN-γ primed THP-1 macrophages when compared to LPS activated cells. The ability of CD200Hi BMMSCs to suppress TNF-α secretion from IFN-γ stimulated THP-1 macrophages was significantly greater when compared to CD200Lo whereas UCBMSCs did not significantly reduce TNF-α secretion. The interference of CD200 binding to the CD200R by anti-CD200 antibody weakened the capability of BMMSCs to inhibit TNF-α secretion from IFN-γ activated THP-1 macrophages. This study clearly demonstrated that the efficiency of BMMSCs to suppress TNF-α secretion of THP-1 macrophages was dependent on the type of stimulus. Moreover, the CD200-CD200r axis could have a previously unidentified role in the BMMSC mediated immunosuppression.

Mitochondrial function and energy metabolism in umbilical cord blood- and bone marrow-derived mesenchymal stem cells

Human mesenchymal stem cells (hMSCs) are an attractive choice for a variety of cellular therapies. hMSCs can be isolated from many different tissues and possess unique mitochondrial properties that can be used to determine their differentiation potential. Mitochondrial properties may possibly be used as a quality measure of hMSC-based products. Accordingly, the present work focuses on the mitochondrial function of hMSCs from umbilical cord blood (UCBMSC) cells and bone marrow cells from donors younger than 18 years of age (BMMSC <18) and those more than 50 years of age (BMMSC >50). Changes of ultrastructure and energy metabolism during osteogenic differentiation in all hMSC types were studied in detail. Results show that despite similar surface antigen characteristics, the UCBMSCs had smaller cell surface area and possessed more abundant rough endoplasmic reticulum than BMMSC >50. BMMSC <18 were morphologically more UCBMSC-like. UCBMSC showed dramatically higher mitochondrial-to-cytoplasm area ratio and elevated superoxide and manganese superoxide dismutase (MnSOD) levels as compared with BMMSC >50 and BMMSC <18. All hMSCs types showed changes indicative of mitochondrial activation after 2 weeks of osteogenic differentiation, and the increase in mitochondrial-to-cytoplasm area ratio appears to be one of the first steps in the differentiation process. However, BMMSC >50 showed a lower level of mitochondrial maturation and differentiation capacity. UCBMSCs and BMMSCs also showed a different pattern of exocytosed proteins and glycoproteoglycansins. These results indicate that hMSCs with similar cell surface antigen expression have different mitochondrial and functional properties, suggesting different maturation levels and other significant biological variations of the hMSCs. Therefore, it appears that mitochondrial analysis presents useful characterization criteria for hMSCs intended for clinical use.

Zeb1 and twist are more commonly expressed in metastatic than primary lung tumours and show inverse associations with claudins

BACKGROUND

Zeb1 and twist regulate expression of genes which take part in epitheliomesenchymal transition (EMT). Claudins are tight junctional proteins regulating polarity and paracellular permeability of epithelial cells.

AIMS AND METHODS

To study Zeb1 and twist in 289 primary and 54 metastatic lung tumours and their relation to expression of claudins 1-5 and 7 by immunohistochemistry.

RESULTS

Metastatic tumours showed a significantly lower expression of zeb1 and twist (33.0% and 38.0% vs 5.0% and 14.5%, p<0.001 for both) and they also had a significantly lower expression of claudin 1 (p<0.001), claudin 4 (p<0.001), claudin 5 (p=0.001) and claudin 7 (p<0.001) than did primary tumours. Primary lung tumours showed a strong inverse association between zeb1 and claudin 1 (p=0.024) and claudin 2 (p=0.003). For twist an inverse association was found with claudin 5 (p=0.007). In metastatic tumours zeb1 was inversely associated with claudin 7 (p=0.050) and twist with claudin 5 (p=0.025). Overexpression of claudin 5 was associated with decreased survival (p=0.017). For zeb1 or twist, no association with survival was observed in primary or metastatic tumours.

CONCLUSIONS

According to protein expression, involvement of zeb1 and twist in EMT in primary lung tumours is relatively infrequent. Carcinomas metastatic to the lung showed a significantly higher expression of these transcriptional factors than primary lung tumours, indicating their probable importance in the metastatic process. Zeb1 and twist were inversely associated with several claudins, indicating a role in their down-regulation.

Impact of smoking on the expression of claudins in lung carcinoma

RATIONALE

Tight junctions regulate the paracellular permeability and orientation of cells and claudins are key components of tight junctions.

OBJECTIVES

To study the influence of cigarette smoke on claudin expression in vitro and in lung cancer patients.

METHODS

We studied the effect of smoking on claudin expression by exposing a bronchial cell line (BEAS-2B) and two carcinoma cell lines (SK-LU1 and SK-MES1) to tobacco smoke for 48 h and analysed their claudin mRNA expression. The relation between smoked pack years and protein expression of claudins 1-5 and 7 in 344 lung cancer patients was determined by immunohistochemistry.

MEASUREMENTS AND MAIN RESULTS

In BEAS-2B cells and SK-LU1 cells, an initial increase was followed by a decline in the mRNA expression of several claudins. In SK-MES1 cells, no evident elevation in claudin expression was observed. Intense claudin 1 and 4 positivity was found more often in cancer samples of smokers and ex-smokers compared to non-smokers (p<0.001 and p=0.003, respectively). Heavy smokers with longer than 40 pack-years consumption had more often intense claudin 1 (p=0.011), 4 (p=0.050) or 7 (p=0.058) expression in squamous cell carcinoma compared to non-smokers or smokers with fewer pack-years. Claudin 1 positivity predicted a better survival in adenocarcinoma (p=0.044) and in squamous cell carcinoma (p=0.027) and claudin 4 positivity in adenocarcinoma only (p=0.048). In squamous cell carcinoma, claudin 7 positivity was associated with a better survival (p=0.011).

CONCLUSIONS

Bronchial BEAS-2B cells and SK-LU1 cells respond to tobacco smoke by changing their claudin mRNA synthesis and resulting tight junction permeability changes may thus contribute to tobacco induced carcinogenesis both during initiation and progression. This concept is strengthened by findings in the clinical tumour material, where tobacco consumption was associated with claudin expression.

Epithelial N-cadherin and nuclear β-catenin are up-regulated during early development of human lung

Background

The aim of this study was to analyze the cell-specific expression of E- and N-cadherin and β-catenin in developing human lung tissues from 12 to 40 weeks of gestation.

Methods

Fortyseven cases of developing human lung including pseudoglandular, canalicular, saccular and alveolar periods were analyzed by immunohistochemisty for E- and N-cadherin and β-catenin and twentyone cases were also investigated by RT-PCR for E- and N-cadherin and β-catenin. For identifying the lung cells, the sections were also stained with antibodies against thyroid transcription factor-1 (TTF-1) and caveolin-1. Normal adult lung tissue was used as a control.

E-cadherin was strongly expressed in epithelium of bronchi and large bronchioles from week 12 onwards and it was also positive in alveoli in pretype II cells and type II cells. N-cadherin was present in most of the epithelial cells of bronchi and the largest bronchioles during the pseudo-glandular and canalicular periods. N-cadherin was not detected in epithelium of developing alveoli. β-catenin was strongly membrane-bound and positively expressed in bronchial epithelium from week 12 to week 40; it showed nuclear positivity in both developing airway epithelium and in the cells underneath the epithelium during pseudo-glandular period and to a lesser degree also in the canalicular period. β-catenin was positive in pretype II cells as well as in type I and type II pneumocytes within alveoli.

RT-PCR analyses revealed detectable amounts of RNAs of E- and N-cadherin and β-catenin in all cases studied. The amounts of RNAs were higher in early stages of gestation.

Conclusions

E-cadherin is widely expressed in bronchial and alveolar epithelial cells. N-cadherin exhibit extensive epithelial positivity in bronchial epithelial cells during early lung development. The presence of β-catenin was observed in several cell types with a distinct location in tissue and cells in various gestational stages, indicating that it possesses several roles during lung development. The expressions of protein and mRNAs of E- and N-cadherin and β-catenin were higher in early gestation compared to of the end. Moreover, the expressions of these factors were higher during the lung development than in the adult human lung.

Mitochondrial function determines the viability and osteogenic potency of human mesenchymal stem cells

Advanced therapies medicinal products (ATMPs) have introduced innovative cell-based products. However, the regulatory demands for characterization of ATMPs are currently unable to adequately address the safety of such products. As recent studies have emphasized the role of mitochondria in the osteogenic differentiation of human mesenchymal stem cells (hMSCs), we have studied in detail the viability and osteogenic differentiation potency of the hMSCs intended for use as ATMPs based on analyses of the mitochondrial inner membrane potential (DeltaPsi(m)). Flow cytometric measurement of 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolcarbocyanine iodide (JC-1), propidium iodide fluorescence, and AnnexinV was employed to determine DeltaPsi(m), plasma membrane integrity, and organization of phosphatidylserine in plasma membrane, respectively, in cultured hMSCs. Apoptosis was induced by incubating cells at critical concentration (20 muM) of menadione. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) was used as an indicator for cell proliferation and alkaline phosphatase activity and calcium deposition as indicators of osteogenic differentiation. Based on JC-1 fluorescence, cell morphology, organization of phosphatidylserine, and plasma membrane integrity, we could sort cells into four categories that represented different cell quality. A strong correlation between JC-1 and osteogenic differentiation was demonstrated for the first time and thus this analytical tool is suitable not only to determine cell viability but also to predict osteogenic differentiation of hMSC.

Toll-like receptor 9 ligands enhance mesenchymal stem cell invasion and expression of matrix metalloprotease-13

Human mesenchymal stem cells (hMSCs) are multipotent cells that are found in the bone marrow. Inflammation and tissue damage mobilize MSCs and induce their migration towards the damaged site through mechanisms that are not well defined. Toll-like receptor-9 (TLR9) is a cellular receptor for microbial and vertebrate DNA. Stimulation of TLR9 induces inflammatory and invasive responses in TLR9-expressing cells. We studied here the expression of TLR9 in human MSCs and the effects of synthetic TLR9-agonists on their invasion. Constitutive expression of TLR9 was detected in human MSCs but the expression was suppressed when MSCs were induced to differentiate into osteoblasts. Using standard invasion assays and a novel organotypic culture model based on human myoma tissue, we discovered that stimulation with the TLR9 agonistic, CpG oligonucleotides increased the invasion capacity of undifferentiated MSCs. Simultaneously, an increase in MMP-13 synthesis and activity was detected in the CpG-activated MSCs. Addition of anti-MMP-13 antibody significantly diminished the CpG-induced hMSC invasion. We conclude that treatment with TLR9-ligands increases MSC invasiveness, and this process is at least partially MMP-13-mediated.

Divergent expression of claudin -1, -3, -4, -5 and -7 in developing human lung

BACKGROUND

Claudins are the main components of tight junctions, structures which are associated with cell polarity and permeability. The aim of this study was to analyze the expression of claudins 1, 3, 4, 5, and 7 in developing human lung tissues from 12 to 40 weeks of gestation.

METHODS

47 cases were analyzed by immunohistochemistry for claudins 1, 3, 4, 5 and 7. 23 cases were also investigated by quantitative RT-PCR for claudin-1, -3 and -4.

RESULTS

Claudin-1 was expressed in epithelium of bronchi and large bronchioles from week 12 onwards but it was not detected in epithelium of developing alveoli. Claudin-3, -4 and -7 were strongly expressed in bronchial epithelium from week 12 to week 40, and they were also expressed in alveoli from week 16 to week 40. Claudin-5 was expressed strongly during all periods in endothelial cells. It was expressed also in epithelium of bronchi from week 12 to week 40, and in alveoli during the canalicular period. RT-PCR analyses revealed detectable amounts of RNAs for claudins 1, 3 and 4 in all cases studied.

CONCLUSION

Claudin-1, -3, -4, -5, and -7 are expressed in developing human lung from week 12 to week 40 with distinct locations and in divergent quantities. The expression of claudin-1 was restricted to the bronchial epithelium, whereas claudin-3, -4 and -7 were positive also in alveolar epithelium as well as in the bronchial epithelium. All claudins studied are linked to the development of airways, whereas claudin-3, -4, -5 and -7, but not claudin-1, are involved in the development of acinus and the differentiation of alveolar epithelial cells.

Acute homing of bone marrow-derived mononuclear cells in intramyocardial vs. intracoronary transplantation

OBJECTIVES

Cell homing optimisation after transplantation is critical in myocardial infarction (MI) cell therapy.

DESIGN

Eight pigs were randomized to receiving autologous purified (111)indium-labeled bone marrow mononuclear cells (BMMCs) (10(8) cells/2 ml) by intramyocardial (IM) (n=4) or by intracoronary (IC) (n=4) transplantation after 90 minutes occlusion of the CX-coronary artery. Dual isotope SPECT imaging was performed 2 and 24 hours postoperatively. Two animals were additionally analyzed on the sixth postoperative day. Tissue samples from the major organs were analyzed.

RESULTS

In SPECT imaging revealed that BMMCs administered using IM injection remained in the injured area. In contrast, minor proportion of IC transplanted cells remained in the myocardium, as most of the cells showed homing in the lungs. Analysis of the biopsies showed a seven-fold greater number of cells in the myocardium for the IM method and a 10-fold greater number of cells in the lungs in the IC group (p < 0.001).

CONCLUSIONS

In producing persistently high cell homing at the infarction site, the IM transplantation is superior to the IC transplantation. However, the IC administration might be more specific in targeting injured capillaries and epithelial cells within the infarcted myocardium.

Neuropsychological outcome and community re-integration following traumatic brain injury: The impact of frontal and non-frontal lesions

PRIMARY OBJECTIVE

To examine the relationship between cortical lesion location and brain injury outcome. It was hypothesized that focal frontal lesions after traumatic brain injury (TBI) would result in decreased executive and memory functioning and poor community participation outcome.

RESEARCH DESIGN

Three quasi-experimental, prospective studies employed a total of 643 patients with focal frontal, fronto-temporal, non-frontal or no lesions in CT scans.

METHODS AND PROCEDURES

CT scan analysis, neuropsychological assessment, the Neurobehavioural Functioning Inventory (NFI), the Community Integration Questionnaire (CIQ).

MAIN RESULTS

In study 1, frontal and fronto-temporal groups performed worse in executive functioning and better in constructional ability. Study 2 found no differences in neuropsychological and community re-integration measures at 1-year follow-up. Study 3 found comparable neuropsychological test score improvement across groups over 1 year.

CONCLUSIONS

Results are consistent with previous findings and document the potential for test score improvement with rehabilitation and suggest that lesion location needs to be considered when individual rehabilitation plans are being implemented in the post-acute stage of TBI.

17beta-estradiol induces the proliferation of the in vitro cultured human urothelium

OBJECTIVE

The genitourinary tract is considered to be a target for the actions of sex steroid hormones. Decreased ovarian function and lack of estrogen after menopause are associated with lower genitourinary tract symptoms as well as bladder dysfunctions such as incontinence. Estrogen may also affect urothelial cells. The estrogen receptors (ERs) are found in the mucosa of the urinary tract. The purpose of this study was to culture human urothelial cells (HUCs) originating from urothelial tissue biopsies and to use them as a reproducible test platform to evaluate the effect of 17beta-estradiol (E2).

MATERIAL AND METHODS

Urothelial tissue biopsies were obtained from 95 patients undergoing gynaecological open surgery for urinary incontinence, paediatric vesicoureteral reflux or transurethral resection of the prostate (TURP) for benign prostatic hyperplasia. HUCs originating from biopsies were cultured in vitro in the absence or in the presence of 0.1 nmol, 0.01 micromol and 1 micromol of E2. ER expression of the cultured HUCs was examined by Western analysis and immunofluorescence microscopy, which was also used for HUC characterization. The effect of E2 in the proliferation of the HUCs was determined by tetrazolium salt 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT)-assay.

RESULTS

HUCs were cultured successfully in four to six passages but there was variation between samples. The cultured cells showed expression of beta(4)-integrin, E-cadherin and cytokeratins 7, 8, 9 and 19, indicating the epithelial origin of the cells. Both types of ERs, ERalpha and ERbeta, were found in the in vitro cultured HUCs. E2 treatment of HUCs did not affect remarkably the expression of ERalpha but cell proliferation was induced. However, no concentration-dependent effect was seen.

CONCLUSIONS

This study indicates that HUCs originating from small tissue biopsies can be cultured in several passages in vitro and could have potential in repairing or restoring urinary tract tissue by tissue engineering therapy. HUCs serve as a good in vitro test platform, as shown by analysing E2-treated HUCs. E2 induced the proliferation of cultured HUCs even though concentration dependency was not observed. The findings of this study may have relevance in determining the mechanisms of estrogen therapy in postmenopausal urinary tract symptoms and in the future development of tissue engineering technology.

Connecting the interpodocyte slit diaphragm and actin dynamics: Emerging role for the nephrin signaling complex

Uchida et al. show in this issue that in rat and human nephrosis, tyrosine phosphorylation of nephrin is reduced, and this is accompanied by a decrease in F-actin in glomeruli. This, together with previous studies, suggests that the nephrin protein complex is a signaling nexus that regulates actin dynamics in podocytes.

Inhibition of cyclooxygenase-2 down-regulates osteoclast and osteoblast differentiation and favours adipocyte formation in vitro

Nonsteroidal anti-inflammatory drugs (NSAIDs) inhibit cyclooxygenases (COX) and are widely used for post-trauma musculoskeletal analgesia. In animal models, NSAIDs have been reported to delay fracture healing and cause non-union, possibly due to the drug-induced inhibition of osteoblast recruitment and differentiation. To further investigate the cellular effects of these drugs in the context of bone healing, we examined the effects of COX-1 inhibitor indomethacin and COX-2 inhibitors, parecoxib and NS398 on osteoclast and osteoblast differentiation and activity in vitro. We discovered that all tested COX-inhibitors significantly inhibited osteoclast differentiation, by 93%, 94% and 74% of control for 100 microM indomethacin, 100 microM parecoxib and 3 microM NS398, respectively. Furthermore, inhibition of COX-2 reduced also the resorption activity of mature osteoclasts. All tested COX-inhibitors also significantly inhibited osteoblast differentiation from human mesenchymal stem cells. Simultaneously, the number of adipocytes was significantly increased. The adipocyte covered areas in the cultures with 1 microM indomethacin, 1 microM parecoxib and 3 microM NS398 were 9%, 29% and 24%, respectively, as compared with 6% in the control group. This data suggests that COX-2 inhibition disturbs bone remodelling by inhibiting osteoclast differentiation and diverting stem cell differentiation towards adipocyte lineage instead of osteoblast lineage. In conclusion, our results further suggest cautious use of COX-2 inhibitors after osseous trauma.

Bone marrow–derived mononuclear cell transplantation improves myocardial recovery by enhancing cellular recruitment and differentiation at the infarction site

OBJECTIVE

Stem cell therapy in myocardial infarction is under intensive investigation; however, the mechanisms of recovery and the optimal transplantation technique remain controversial. The goal of this controlled and randomized study was to test the hypothesis that locally injected bone marrow-derived mononuclear cells can focus in on the damaged myocardium and improve cardiac function by means of active participation in remodeling.

METHODS

Myocardial infarction was introduced through occlusion of the circumflex coronary artery for 90 minutes in 14 piglets (24.0 +/- 4.9 kg) that were randomized to a cell-therapy group (n = 7) and a control group (n = 7). At reperfusion, autologous purified prelabeled or unlabeled cells (10(8) cells/2 mL) or saline were injected into the myocardium. Cardiac function was measured by using echocardiography preoperatively and postoperatively and at 3 weeks, when hearts were collected for histopathologic examination.

RESULTS

The ejection fraction recovered in the cell-therapy group (P = .02) but failed to recover in the control group, and at 3 weeks, it remained at the lower level compared with that in the cell-therapy group (P = .067). The number of living cells in the necrotic area was significantly greater in the cell-therapy group (P < .001). Labeled cells were detected in the infarcted area, and they showed signs of myocyte differentiation. Furthermore, the proportional area of muscle actin-positive cells at the granulation area was higher in the cell-therapy group (P = .035).

CONCLUSIONS

Autologous bone marrow-derived mononuclear cells at the infarcted area localize in the myocardium. The exact mechanism of recovery remains to be determined, but our findings may give new information concerning the cellular events that occur during cell therapy-enhanced recovery.

Estrogen receptor alpha genotype confers interindividual variability of response to estrogen and testosterone in mesenchymal-stem-cell-derived osteoblasts

Hormone replacement therapy is effectively used to prevent postmenopausal bone loss. Variation in response to the therapy is, however, frequently seen. In addition, the direct effects of sex steroids on isolated human bone marrow stromal cells have been reported to vary depending on the donor, but the biological mechanisms are not understood. The aim of this study was to investigate the effects of 17beta-estradiol (E2) and testosterone in human-bone-marrow-derived mesenchymal stem cell (MSC) cultures from both female and male donors of various ages. The osteoblast differentiation capacity and activity of the MSCs were quantified in vitro by measuring alkaline phosphatase activity and calcium deposition. We show here that also the osteoblast responses of MSCs to sex hormones vary widely depending on the donor. When the results from all donors were analyzed together, treatment with E2 increased calcium deposition significantly by MSCs of both sexes but ALP activity only in the male MSCs. Testosterone had no effect on ALP activity nor calcium deposition in either sex. To further characterize the individual variation, we investigated estrogen receptor alpha PvuII restriction site polymorphism with PCR. Restriction fragment-length polymorphism was assigned as P or non-P, P signifying the absence of the restriction site. Our results indicate that higher basal osteoblast differentiation capacity of MSCs is associated with the presence of the P allele in females, whereas higher response to sex steroids treatment is associated with the non-P allele. These results could help explain the contradictory effects of E2 on osteoblasts in vitro and might also provide new insights to understanding the differences in responses to hormone replacement therapy.

Two functional variants of the superoxide dismutase genes in Finnish families with asthma

BACKGROUND

Functional polymorphisms in the genes encoding superoxide dismutases (SOD)-that is, superoxide scavenging antioxidant enzymes-may play an important role in the development of inflammatory airway diseases such as asthma.

METHODS

The allele frequencies of two missense polymorphisms of SOD genes (Ala16Val in MnSOD (SOD2) and Arg213Gly in ECSOD (SOD3)) were investigated in Finnish patients with asthma and compared with family based controls. Both variants have been shown to be functionally interesting in the lung. The polymorphism at the exon-intron 3 boundary of a third SOD, CuZnSOD (SOD1), was also included in the analysis.

RESULTS

None of the SOD genetic variants studied appeared to be major genetic regulators in the development of asthma. We could exclude all models of inheritance that increased the risk of asthma more than 1.2 fold for MnSOD*Val (frequency of allele 0.74 in the population) and more than 6.6 fold for ECSOD*Gly213 (frequency of allele 0.03 in the population) compared with non-carriers. For the intronic polymorphism in CuZnSOD, a relative risk of more than 3.3 (frequency of allele 0.10 in the population) could be excluded.

CONCLUSIONS

It is highly unlikely that the functionally important genetic variants Ala16Val and Arg213Gly of SODs play a major role in the genetic susceptibility of asthma.