Browsing by Subject "MACROPHAGES"

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  • Kortesoja, Maarit; Trofin, Raluca Elena; Hanski, Leena (2020)
    The obligate intracellular bacterium, Chlamydia pneumoniae, has been identified as a risk factor for several chronic inflammatory diseases in addition to respiratory tract infections. The dissemination of C. pneumoniae from respiratory tract to secondary sites of infection occurs via infected monocyte / macrophage line cells, in which C. pneumoniae can persist as an antibiotic-refractory phenotype. To allow more detailed studies on the epithelium-monocyte/macrophage transition of the infection, new in vitro bioassays are needed. To this end, a coculture system with human continuous cell lines was established. Respiratory epithelial HL cells were infected with C. pneumoniae and THP-1 monocytes were added into the cultures at 67 h post infection. After a 5 h coculture, THP-1 cells were collected with a biotinylated HLA antibody and streptavidin-coated magnetic beads and C. pneumoniae genome copy numbers in THP-1 determined by quantitative PCR. The assay was optimized for cell densities, incubation time, THP-1 separation technique and buffer composition, and its robustness was demonstrated by a Z' value of 0.6. The mitogen-activated protein kinase (MAPK) inhibitors: SP600125 (JNK inhibitor), SB203580 (p38 inhibitor) and FR180204 (ERK inhibitor) suppressed the transfer of C. pneumoniae from HL to THP-1 cells, making them suitable positive controls for the assay. Based on analysis of separate steps of the process, the MAPK inhibitors suppress the bacterial entry to THP-1 cells. The transfer of C. pneumoniae from epithelium to phagocytes represents a crucial step in the establishment of persistent infections by this pathogen, and the presented methods enables future studies to block this process by therapeutic means.
  • Li, Zhilin; Korhonen, Emilia A.; Merlini, Arianna; Strauss, Judith; Wihuri, Eleonoora; Nurmi, Harri; Antila, Salli; Paech, Jennifer; Deutsch, Urban; Engelhardt, Britta; Chintharlapalli, Sudhakar; Koh, Gou Young; Flügel, Alexander; Alitalo, Kari (2020)
    Angiopoietin-2 (Ang2), a ligand of the endothelial Tie2 tyrosine kinase, is involved in vascular inflammation and leakage in critically ill patients. However, the role of Ang2 in demyelinating central nervous system (CNS) autoimmune diseases is unknown. Here, we report that Ang2 is critically involved in the pathogenesis of experimental autoimmune encephalomyelitis (EAE), a rodent model of multiple sclerosis. Ang2 expression was induced in CNS autoimmunity, and transgenic mice overexpressing Ang2 specifically in endothelial cells (ECs) developed a significantly more severe EAE. In contrast, treatment with Ang2-blocking Abs ameliorated neuroinflammation and decreased spinal cord demyelination and leukocyte infiltration into the CNS. Similarly, Ang2-binding and Tie2-activating Ab attenuated the development of CNS autoimmune disease. Ang2 blockade inhibited expression of EC adhesion molecules, improved blood-brain barrier integrity, and decreased expression of genes involved in antigen presentation and proinflammatory responses of microglia and macrophages, which was accompanied by inhibition of α5β1 integrin activation in microglia. Taken together, our data suggest that Ang2 provides a target for increasing Tie2 activation in ECs and inhibiting proinflammatory polarization of CNS myeloid cells via α5β1 integrin in neuroinflammation. Thus, Ang2 targeting may serve as a therapeutic option for the treatment of CNS autoimmune disease.
  • Arnal-Levron, Maud; Chen, Yinan; Greimel, Peter; Calevro, Federica; Gaget, Karen; Riols, Fabien; Batut, Aurélie; Bertrand-Michel, Justine; Hullin-Matsuda, Françoise; Olkkonen, Vesa M.; Delton, Isabelle; Luquain-Costaz, Céline (2019)
    Bis(Monoacylglycero) Phosphate (BMP) is a unique phospholipid localized in late endosomes, a critical cellular compartment in low density lipoprotein (LDL)-cholesterol metabolism. In previous work, we demonstrated the important role of BMP in the regulation of macrophage cholesterol homeostasis. BMP exerts a protective role against the pro-apoptotic effect of oxidized LDL (oxLDL) by reducing the production of deleterious oxysterols. As the intracellular sterol traffic in macrophages is in part regulated by oxysterol binding protein (OSBP) and OSBP-related proteins (ORPs), we investigated the role of ORP11, localized at the Golgi-late endosomes interface, in the BMP-mediated protection from oxLDL/oxysterol cytotoxicity. Stably silencing of ORP11 in mouse RAW264.7 macrophages via a shRNA lentiviruses system had no effect on BMP production. However, ORP11 knockdown abrogated the protective action of BMP against oxLDL induced apoptosis. In oxLDL treated control cells, BMP enrichment was associated with reduced generation of 7-oxysterols, while these oxysterol species were abundant in the ORP11 knock-down cells. Of note, BMP enrichment in ORP11 knock-down cells was associated with a drastic increase in free cholesterol and linked to a decrease of cholesterol efflux. The expression of ATP-binding cassette-transporter G1 (ABCG1) was also reduced in the ORP11 knock-down cells. These observations demonstrate a cooperative function of OPR11 and BMP, in intracellular cholesterol trafficking in cultured macrophages. We suggest that BMP favors the egress of cholesterol from late endosomes via an ORP11-dependent mechanism, resulting in a reduced production of cytotoxic 7-oxysterols.
  • Vered, Marilena; Shnaiderman-Shapiro, Anna; Zlotogorski-Hurvitz, Ayelet; Salo, Tuula; Yahalom, Ran (2019)
    Objectives: To examine different immunophenotypes of cancer-associated fibroblasts (CAFs) in tongue squamous cell carcinoma (TSCC) and to investigate how they related to clinical outcomes. Methods: Serial sections from 54 cases of TSCC were immunohistochemically stained with a-smooth muscle actin (alpha SMA, CAF marker) to determine CAF density, and double-immunostained with alpha SMA combined with CD80 and CD86 (myeloid/monocytic-derived cell markers), Nanog (mesenchymal stem cell marker) and CD133 (hematopoietic/endothelial stem cell marker). Density of cells co-expressing these marker combinations was semi-quantitatively assessed in 5 randomly selected high power fields within the tumor area and scored as 1 - one-to-five stained cells in each field, 2 - more than 5 stained cells in each field; any finding less than score 1, was allocated a score of 0. Results: There were 26 CAF-poor, 16 CAF-rich and 12 CAF-intermediated cases. CD86(+) alpha SMA(+) cells were the most frequent (80.4%) followed by CD80(+) alpha SMA(+) (72%) and Nanog(+) alpha SMA(+) cells (56%). The CD133(+) alpha SMA(+) phenotype was found only in association with blood vessels. High density of aSMA CAFs was associated with disease recurrence and poor survival (p <0.05). Increased density of CD86(+) alpha SMA(+) cells was significantly associated with CAF-rich tumors and with poor survival (p <0.05). Conclusion: In TSCC, CAFs demonstrate heterogeneous and overlapping phenotypes with the myeloid/monocytic type being the most frequent and having an impact on the clinical outcomes. Further studies are needed in order to further characterize CAF phenotypes in carcinomas of various oral sites, as this may open new frontiers for personalized medicine.
  • Castelblanco, Esmeralda; Sarrias, Maria R.; Betriu, Angels; Soldevila, Berta; Barranco-Altirriba, Maria; Franch-Nadal, Josep; Valdivielso, Jose M.; Bermudez-Lopez, Marcelino; Groop, Per-Henrik; Fernandez, Elvira; Alonso, Nuria; Mauricio, Didac (2021)
    This study assessed the association of CD5L and soluble CD36 (sCD36) with the risk of a cardiovascular event (CVE), including CV death and all-cause mortality in CKD. We evaluated the association of CD5L and sCD36 with a predefined composite CV endpoint (unstable angina, myocardial infarction, transient ischemic attack, cerebrovascular accident, congestive heart failure, arrhythmia, peripheral arterial disease [PAD] or amputation by PAD, aortic aneurysm, or death from CV causes) and all-cause mortality using Cox proportional hazards regression, adjusted for CV risk factors. The analysis included 1,516 participants free from pre-existing CV disease followed up for 4 years. The median age was 62 years, 38.8% were female, and 26.8% had diabetes. There were 98 (6.5%) CVEs and 72 (4.8%) deaths, of which 26 (36.1%) were of CV origin. Higher baseline CD5L concentration was associated with increased risk of CVE (HR, 95% CI, 1.17, 1.0-1.36), and all-cause mortality (1.22, 1.01-1.48) after adjusting for age, sex, diabetes, systolic blood pressure, dyslipidemia, waist circumference, smoking, and CKD stage. sCD36 showed no association with adverse CV outcomes or mortality. Our study showed for the first time that higher concentrations of CD5L are associated with future CVE and all -cause mortality in individuals with CKD.
  • Al-Samadi, Ahmed; Awad, Shady Adnan; Tuomainen, Katja; Zhao, Yue; Salem, Abdelhakim; Parikka, Mataleena; Salo, Tuula (2017)
    The crosstalk between immune cells, cancer cells, and extracellular vesicles (EVs) secreted by cancer cells remains poorly understood. We created three-dimensional (3D) cell culture models using human leiomyoma discs and Myogel to study the effects of immune cells on highly (HSC-3) and less (SCC-25) invasive oral tongue squamous cell carcinoma (OTSCC) cell lines. Additionally, we studied the effects of EVs isolated from these cell lines on the cytotoxicity of CD8(+) T and NK cells isolated from three healthy donors. Our analysis included the effects of these EVs on innate immunity in zebrafish larvae. Activated immune cells significantly decreased the proliferation of both OTSCC cell lines and associated with a diminished invasion area of HSC-3 cells. In general, EVs from SCC-25 increased the cytotoxic activity of CD8(+) T and NK cells more than those from HSC-3 cells. However, this effect varied depending on the source and the immune and cancer cell subgroups. In zebrafish, the amount of IL-13 mRNA was decreased by SCC-25 EVs. This study describes promising in vitro and in vivo models to investigate interactions between immune cells, cancer cells, and EVs.
  • Kolsi, Laura E.; Leal, Ana S.; Yli-Kauhaluoma, Jari; Liby, Karen T.; Moreira, Vânia M. (2018)
    Low 5-year survival rates, increasing incidence, as well as the specific challenges of targeting pancreatic cancer, clearly support an urgent need for new multifunctional drugs for the prevention and treatment of this fatal disease. Natural products, such as abietane-type diterpenoids, are widely studied as promiscuous anticancer agents. In this study, dehydroabietic oximes were identified as potential compounds to target pancreatic cancer and cancer-related inflammation. The compounds inhibited the growth of human pancreatic cancer Aspc-1 cells with IC50 values in the low micromolar range and showed anti-inflammatory activity, measured as the inhibition of nitric oxide production, an important inflammatory mediator in the tumour microenvironment. Further studies revealed that the compounds were able to induce cancer cell differentiation and concomitantly downregulate cyclin D1 expression with upregulation of p27 levels, consistent with cell cycle arrest at the G1 phase. Moreover, a kinase profiling study showed that one of the compounds has isoform-selective, however modest, inhibitory activity on RSK2, an AGC kinase that has been implicated in cellular invasion and metastasis.
  • Honkanen, Hanne-Kaisa; Izzi, Valerio; Petaisto, Tiina; Holopainen, Tanja; Harjunen, Vanessa; Pihlajaniemi, Taina; Alitalo, Kari; Heljasvaara, Ritva (2016)
    Vascular endothelial growth factor D (VEGF-D) promotes the lymph node metastasis of cancer by inducing the growth of lymphatic vasculature, but its specific roles in tumorigenesis have not been elucidated. We monitored the effects of VEGF-D in cutaneous squamous cell carcinoma (cSCC) by subjecting transgenic mice overexpressing VEGF-D in the skin (K14-mVEGF-D) and VEGF-D knockout mice to a chemical skin carcinogenesis protocol involving 7,12-dimethylbenz[a] anthracene and 12-O-tetradecanoylphorbol-13-acetate treatments. In K14-mVEGF-Dmice, tumor lymphangiogenesis was significantly increased and the frequency of lymph node metastasis was elevated in comparison with controls. Most notably, the papillomas regressed more often in K14-mVEGF-D mice than in littermate controls, resulting in a delay in tumor incidence and a remarkable reduction in the total tumor number. Skin tumor growth and metastasis were not obviously affected in the absence of VEGF-D; however, the knockout mice showed a trend for reduced lymphangiogenesis in skin tumors and in the untreated skin. Interestingly, K14-mVEGF-D mice showed an altered immune response in skin tumors. This consisted of the reduced accumulation of macrophages, mast cells, and CD4(+) T-cells and an increase of cytotoxic CD8(+) T-cells. Cytokine profiling by flow cytometry and quantitative real time PCR revealed that elevated VEGF-D expression results in an attenuated Th2 response and promotes M1/Th1 and Th17 polarization in the early stage of skin carcinogenesis, leading to an anti-tumoral immune environment and the regression of primary tumors. Our data suggest that VEGF-D may be beneficial in early-stage tumors since it suppresses the pro-tumorigenic inflammation, while at later stages VEGF-D-induced tumor lymphatics provide a route for metastasis.
  • Lohela, Marja; Alitalo, Kari (2017)
    High-grade gliomas are aggressive and abundantly vascular tumors, and as in most cancer types, blood vessels in advanced lesions are highly abnormal. Poor perfusion and vascular leakage in tumor tissue resulting in hypoxia, necrosis, and high interstitial fluid pressure can hamper the efficient delivery of chemotherapy. Tumor angiogenesis is known to be supported by host leukocytes recruited to the tumor microenvironment, but the mechanisms leading to dysfunctional vascular network formation are incompletely understood. In this issue of EMBO Molecular Medicine, Mathivet et al (2017) present an elegant study, where longitudinal intravital imaging gives new insight on how recruitment and polarization of tumor-associated macrophages regulate aberrant angiogenesis in experimental gliomas. They show that macrophage targeting results in vessel normalization and improved chemotherapy response, suggesting that the combination of these therapeutic modalities could improve the outcome of glioma treatment in the clinic.
  • Jonsson, Martina; Jestoi, Marika; Anthoni, Minna; Welling, Annikki; Loivamaa, Iida; Hallikainen, Ville; Kankainen, Matti; Lysoe, Erik; Koivisto, Pertti; Peltonen, Kimmo (2016)
    The mycotoxin enniatin B, a cyclic hexadepsipeptide produced by the plant pathogen Fusarium, is prevalent in grains and grain-based products in different geographical areas. Although enniatins have not been associated with toxic outbreaks, they have caused toxicity in vitro in several cell lines. In this study, the cytotoxic effects of enniatin B were assessed in relation to cellular energy metabolism, cell proliferation, and the induction of apoptosis in Balb 3T3 and HepG2 cells. The mechanism of toxicity was examined by means of whole genome expression profiling of exposed rat primary hepatocytes. Enniatin B altered cellular energy metabolism and reduced cell proliferation in Balb 3T3 and HepG2 cell lines. Furthermore, the proportion of apoptotic cell populations of Balb 3T3 cells slightly increased. On the other hand, enniatin B caused necrotic cell death in primary hepatocytes. Gene expression studies revealed the alteration of energy metabolism due to effects on mitochondrial organization and function and the assembly of complex I of the electron transport chain. (C) 2016 Elsevier Ltd. All rights reserved.
  • Freitag, Tobias L.; Podojil, Joseph R.; Pearson, Ryan M.; Fokta, Frank J.; Sahl, Cecilia; Messing, Marcel; Andersson, Leif C.; Leskinen, Katarzyna; Saavalainen, Päivi; Hoover, Lisa I.; Huang, Kelly; Phippard, Deborah; Maleki, Sanaz; King, Nicholas J. C.; Shea, Lonnie D.; Miller, Stephen D.; Meri, Seppo K.; Getts, Daniel R. (2020)
  • Hoekstra, Menno; Ren, Baoyan; Laurila, Pirkka-Pekka; Hildebrand, Reeni B.; Soronen, Jarkko; Frodermann, Vanessa; Li, Zhuang; Boon, Mariette R.; Geerling, Janine J.; Rensen, Patrick C. N.; Jauhiainen, Matti; Van Eck, Miranda (2021)
    Total body upstream stimulatory factor 1 (USF1) deficiency in mice is associated with brown adipose tissue activation and a marked protection against the development of obesity and atherosclerotic lesions. Functional expression of USF1 has also been detected in monocytes and monocyte-derived macrophages. In the current study we therefore tested whether selective hematopoietic USF1 deficiency can also beneficially impact the development of atherosclerosis. For this purpose, LDL receptor knockout mice were transplanted with bone marrow from USF1 knockout mice or their wild-type littermate controls and subsequently fed a Western-type diet for 20 weeks to stimulate atherosclerotic lesion development. Strikingly, absence of USF1 function in bone marrow-derived cells was associated with exacerbated blood leukocyte (+ 100%; P < 0.01) and peritoneal leukocyte (+ 50%; P < 0.05) lipid loading and an increased atherosclerosis susceptibility (+ 31%; P < 0.05). These effects could be attributed to aggravated hyperlipidemia, i.e. higher plasma free cholesterol (+ 33%; P < 0.001) and cholesteryl esters (+ 39%; P < 0.001), and the development of hepatosteatosis. In conclusion, we have shown that hematopoietic USF1 deficiency is associated with an increased atherosclerosis susceptibility in LDL receptor knockout mice. These findings argue against a contribution of macrophage-specific USF1 deficiency to the previously described beneficial effect of total body USF1 deficiency on atherosclerosis susceptibility in mice.
  • Perelygina, Ludmila; Hautala, Timo; Seppänen, Mikko; Adebayo, Adebola; Sullivan, Kathleen E.; Icenogle, Joseph (2017)
    Persistent rubella virus (RV) infection has been associated with various pathologies such as congenital rubella syndrome, Fuchs's uveitis, and cutaneous granulomas in patients with primary immune deficiencies (PID). Currently there are no drugs to treat RV infections. Nitazoxanide (NTZ) is an FDA-approved drug for parasitic infections, and has been recently shown to have broad-spectrum antiviral activities. Here we found that empiric 2-month therapy with oral NTZ was associated in the decline/elimination of RV antigen from lesions in a PID patient with RV positive granulomas, while peginterferon treatment had no effect. In addition, we characterized the effects of NTZ on cell culture models of persistent RV infection. NTZ significantly inhibited RV replication in a primary culture of human umbilical vein endothelial cells (HUVEC) and Vero and A549 epithelial cell lines in a dose dependent manner with an average 50% inhibitory concentration of 0.35 mu g/ml (1.1 mu M). RV strains representing currently circulating genotypes were inhibited to a similar extent. NTZ affected early and late stages of infection by inhibiting synthesis of cellular and RV RNA and interfering with intracellular trafficking of the RV surface glycoproteins, E1 and E2. These results suggest a potential application of NTZ for the treatment of persistent rubella infections, but more studies are required.
  • Mulari, Severi; Eskin, Arda; Lampinen, Milla; Nummi, Annu; Nieminen, Tuomo; Teittinen, Kari; Ojala, Teija; Kankainen, Matti; Vento, Antti; Laurikka, Jari; Kupari, Markku; Harjula, Ari; Tuncbag, Nurcan; Kankuri, Esko (2021)
    Background: Although many pathological changes have been associated with ischemic heart disease (IHD), molecular-level alterations specific to the ischemic myocardium and their potential to reflect disease severity or therapeutic outcome remain unclear. Currently, diagnosis occurs relatively late and evaluating disease severity is largely based on clinical symptoms, various imaging modalities, or the determination of risk factors. This study aims to identify IHD-associated signature RNAs from the atrial myocardium and evaluate their ability to reflect disease severity or cardiac surgery outcomes.Methods and Results: We collected right atrial appendage (RAA) biopsies from 40 patients with invasive coronary angiography (ICA)-positive IHD undergoing coronary artery bypass surgery and from 8 patients ICA-negative for IHD (non-IHD) undergoing valvular surgery. Following RNA sequencing, RAA transcriptomes were analyzed against 429 donors from the GTEx project without cardiac disease. The IHD transcriptome was characterized by repressed RNA expression in pathways for cell-cell contacts and mitochondrial dysfunction. Increased expressions of the CSRNP3, FUT10, SHD, NAV2-AS4, and hsa-mir-181 genes resulted in significance with the complexity of coronary artery obstructions or correlated with a functional cardiac benefit from bypass surgery.Conclusions: Our results provide an atrial myocardium-focused insight into IHD signature RNAs. The specific gene expression changes characterized here, pave the way for future disease mechanism-based identification of biomarkers for early detection and treatment of IHD.
  • Purhonen, Janne; Rajendran, Jayasimman; Morgelin, Matthias; Uusi-Rauva, Kristiina; Katayama, Shintaro; Krjutskov, Kaarel; Einarsdottir, Elisabet; Velagapudi, Vidya; Kere, Juha; Jauhiainen, Matti; Fellman, Vineta; Kallijarvi, Jukka (2017)
    Mitochondrial disorders are among the most prevalent inborn errors of metabolism but largely lack treatments and have poor outcomes. High-fat, low-carbohydrate ketogenic diets (KDs) have shown beneficial effects in mouse models of mitochondrial myopathies, with induction of mitochondrial biogenesis as the suggested main mechanism. We fed KD to mice with respiratory chain complex III (CIII) deficiency and progressive hepatopathy due to mutated BCS1L, a CIII assembly factor. The mutant mice became persistently ketotic and tolerated the KD for up to 11 weeks. Liver disease progression was attenuated by KD as shown by delayed fibrosis, reduced cell death, inhibition of hepatic progenitor cell response and stellate cell activation, and normalization of liver enzyme activities. Despite no clear signs of increased mitochondrial biogenesis in the liver, CIII assembly and activity were improved and mitochondrial morphology in hepatocytes normalized. Induction of hepatic glutathione transferase genes and elevated total glutathione level were normalized by KD. Histological findings and transcriptome changes indicated modulation of liver macrophage populations by the mutation and the diet. These results reveal a striking beneficial hepatic response to KD in mice with mitochondrial hepatopathy and warrant further investigations of dietary modification in the management of these conditions in patients.
  • Hasan, S.; Saha, S.; Junnikkala, S.; Orro, T.; Peltoniemi, O.; Oliviero, C. (2019)
    Resin acid-enriched composition (RAC) mainly containing tall oil fatty acid with an active component of resin acid (RA) can improve the microbial population in the digestive system, change the microbial fermentation, and improve the feed conversion ratio. We investigated the effects of dietary supplementation of RAC on sow colostrum yield (CY), colostrum composition and gut microbiota. Tall oil fatty acid and RA are commonly termed RAC and CLA, pinolenic, abietic, dehydrobiotic acids are characteristic components of RAC. The experiment was conducted in three trials in three respective herds. Sows were fed with a control diet and the same diet supplemented with 5 g RAC/day per sow during the last week of gestation. The 16S ribosomal RNA gene sequencing technique was used to assess sows' faecal microbiota populations at farrowing. Colostrum nutritional composition, acute phase proteins (APPs) and immunoglobulin (Ig) content were also assessed. Individual piglets were weighed at birth and 24 h after the birth of first piglets in order to calculate CY and later at 3 to 4 weeks to calculate average daily gain. The RAC-fed sows had significantly higher IgG levels (P0.05), but those fed RAC had higher levels of colostrum serum amyloid A. Colostrum yield was significantly higher in RAC-fed sows in herds 2 and 3 with heavier piglets between 3 and 4 weeks of age (P0.05). Resin acid-enriched composition supplementation significantly increased some beneficial and fermentative bacteria (Romboutsia and Clostridium sensu stricto) than the control diet (P
  • Dichlberger, Andrea; Schlager, Stefanie; Lappalainen, Jani; Käkelä, Reijo; Hattula, Katarina; Butcher, Sarah J.; Schneider, Wolfgang J.; Kovanen, Petri T. (2011)
  • Mannisto, Ville T.; Simonen, Marko; Soininen, Pasi; Tiainen, Mika; Kangas, Antti J.; Kaminska, Dorota; Venesmaa, Sari; Kakela, Pirjo; Karja, Vesa; Gylling, Helena; Ala-Korpela, Mika; Pihlajamaki, Jussi (2014)
  • Sarhadi, Virinder Kaur; Daddali, Ravindra; Seppänen-Kaijansinkko, Riitta (2021)
    Osteosarcoma (OS) is an aggressive bone tumor that mainly affects children and adolescents. OS has a strong tendency to relapse and metastasize, resulting in poor prognosis and survival. The high heterogeneity and genetic complexity of OS make it challenging to identify new therapeutic targets. Mesenchymal stem cells (MSCs) are multipotent stem cells that can differentiate into adipocytes, osteoblasts, or chondroblasts. OS is thought to originate at some stage in the differentiation process of MSC to pre-osteoblast or from osteoblast precursors. MSCs contribute to OS progression by interacting with tumor cells via paracrine signaling and affect tumor cell proliferation, invasion, angiogenesis, immune response, and metastasis. Extracellular vesicles (EVs), secreted by OS cells and MSCs in the tumor microenvironment, are crucial mediators of intercellular communication, driving OS progression by transferring miRNAs/RNA and proteins to other cells. MSC-derived EVs have both pro-tumor and anti-tumor effects on OS progression. MSC-EVs can be also engineered to deliver anti-tumor cargo to the tumor site, which offers potential applications in MSC-EV-based OS treatment. In this review, we highlight the role of MSCs in OS, with a focus on EV-mediated communication between OS cells and MSCs and their role in OS pathogenesis and therapy.
  • Eguiluz-Gracia, Ibon; Malmström, Kristiina; Dheyauldeen, Sinan Ahmed; Lohi, Jouko; Sajantila, Antti; Aalokken, Ragnhild; Sundaram, Arvind Y. M.; Gilfillan, Gregor D.; Makela, Mika; Baekkevold, Espen S.; Jahnsen, Frode L. (2018)
    Background: Activated T helper type 2 (Th2) cells are believed to play a pivotal role in allergic airway inflammation, but which cells attract and activate Th2 cells locally have not been fully determined. Recently, it was shown in an experimental human model of allergic rhinitis (AR) that activated monocytes rapidly accumulate in the nasal mucosa after local allergen challenge, where they promote recruitment of Th2 cells and eosinophils. Objective: To investigate whether monocytes are recruited to the lungs in paediatric asthma. Methods: Tissue samples obtained from children and adolescents with fatal asthma attack (n = 12), age-matched non-atopic controls (n = 9) and allergen-challenged AR patients (n = 8) were subjected to in situ immunostaining. Results: Monocytes, identified as CD68+S100A8/A9+ cells, were significantly increased in the lower airway mucosa and in the alveoli of fatal asthma patients compared with control individuals. Interestingly, cellular aggregates containing CD68+S100A8/A9+ monocytes obstructing the lumen of bronchioles were found in asthmatics (8 out of 12) but not in controls. Analysing tissue specimens from challenged AR patients, we confirmed that co-staining with CD68 and S100A8/A9 was a valid method to identify recently recruited monocytes. We also showed that the vast majority of accumulating monocytes both in the lungs and in the nasal mucosa expressed matrix metalloproteinase 10, suggesting that this protein may be involved in their migration within the tissue. Conclusions and clinical relevance: Monocytes accumulated in the lungs of children and adolescents with fatal asthma attack. This finding strongly suggests that monocytes are directly involved in the immunopathology of asthma and that these pro-inflammatory cells are potential targets for therapy.