Heterogeneous phenotype of human glioblastoma: in vitro study.

Glioblastomas (GBMs) are the most lethal primary brain tumours. Increasing evidence shows that brain tumours contain the population of stem cells, so-called cancer stem cells (CSCs). Stem cell marker CD133 was reported to identify CSC population in GBM. Further studies have indicated that CD133 negative cells exhibiting similar properties and are able to initiate the tumour, self-renew and undergo multilineage differentiation. GBM is a highly heterogeneous tumour and may contain different stem cell populations with different functional properties. We characterized five GBM cell lines, established from surgical samples, according to the marker expression, proliferation and differentiation potential. CD133 positive cell lines showed increased proliferation rate in neurosphere condition and marked differentiation potential towards neuronal lineages. Whereas two cell lines low-expressing CD133 marker showed mesenchymal properties in vitro, that is high proliferation rate in serum condition and differentiation in mesenchymal cell types. Further, we compared therapy resistance capacity of GBM cell lines treated with hydroxyurea. Our results suggest that CSC concept is more complex than it was believed before, and CD133 could not define entire stem cell population within GBM. At least two different subtypes of GBM CSCs exist, which may have different biological characteristics and imply different therapeutic strategies.

Protective effects of polydeoxyribonucleotides on cartilage degradation in experimental cultures.

The capacity of cartilage self-regeneration is considered to be limited. Joint injuries often evolve in the development of chronic wounds on the cartilage surface. Such lesions are associated with articular cartilage degeneration and osteoarthritis. Re-establishing a correct micro/macro-environment into damaged joints could stop or prevent the degenerative processes. This study investigated the effect of polydeoxyribonucleotides (PDRNs) on cartilage degradation in vitro and on cartilage extracted cells. The activities of matrix metalloproteinases 2 and 9 were measured in PDRN-treated cells and in controls at days 0 and 30 of culture. Human nasal cartilage explants were cultured, and the degree of proteoglycan degradation was assessed by measuring the amount of glycosaminoglycans released into the culture medium. The PDRN properties compared with controls were tested on cartilage tissues to evaluate deposition of extracellular matrix. Chondrocytes treated with PDRNs showed a physiological deposition of extracellular matrix (aggrecan and type II collagen: Western blot, IFA, fluorescence activated cell sorting, Alcian blue and safranin O staining). PDRNs were able to inhibit proteoglycan degradation in cartilage explants. The activities of matrix metalloproteinases 2 and 9 were reduced in all PDRN-treated samples. Our results indicate that PDRNs are suitable for a long-term cultivation of in vitro cartilage and have therapeutic effects on chondrocytes by protecting cartilage.

A novel composition for in vitro and in vivo regeneration of skin and connective tissues.

The particular combination of polydeoxyribonucleotides, l-carnitine, calcium ions, proteolytic enzyme and other ingredients acts in a synergetic way in the regeneration of skin and connective tissues. This new formulation of active principles was tested in vitro as a cell and tissue culture medium and in vivo for various preparations in support of tissue regeneration. In vitro, the new blend allowed the maintenance of skin biopsies for more than 1 year in eutrophic conditions. Immunocytochemical analyses of fibroblasts isolated from these biopsies confirmed a significant increase of the epidermal and connective wound-healing markers such as collagen type I, collagen type IV, cytokeratin 1 (CK1), CK5, CK10 and CK14 versus controls. To examine the effects of the new compound in vivo, we studied impaired wound healing in genetically diabetic db/db mice. At day 18, diabetic mice treated with the new composition showed 100% closure of wounds and faster healing than mice treated with the other solutions. This complex of vital continuity factors or life-keeping factors could be used as a tissue-preserving solution or a cosmetic/drug/medical device to accelerate wound healing in the treatment of patients with deficient wound repair to promote the regeneration of cutaneous and connective tissues (injuries-wound, dermatitis) and prevent the recurrent relapses.

Microparticles in physiological and in pathological conditions.

Chronic diseases pose a severe burden to modern National Health Systems. Individuals nowadays have a far more extended lifespan than in the past, but healthy living was only scantily extended. As much as longer life is desirable, it is saddened by chronic diseases and organ malfunctions. One contributor to these problems was recognized to be represented by microparticles (MPs). Our purpose is to better understand MPs, to contrast their ominous threat and possible clinical importance. For this intent we correlated MPs with thrombotic pathologies, hemophilia, malaria, diabetes, cardiovascular diseases, endothelial dysfunctions, pulmonary hypertension, ischemic stroke, pre-eclampsia, rheumatologic diseases-rheumatoid arthritis, polymyositis-dermatomyositis, angiogenesis and tumor progression-cancer; we listed the possibilities of using them to improve transfusion methods, as a marker for acute allograft rejection, in stem cell transplantation, as neuronal biomarkers, to understand gender-specific susceptibility for diseases and to improve vaccination methods and we presented some methods for the detection of MPs.

Glioblastoma cancer stem cells: heterogeneity, microenvironment and related therapeutic strategies.

Glioblastoma Multiforme (GBM) is an incurable malignancy. GBM patients have a short life expectancy despite aggressive therapeutic approaches based on surgical resection followed by adjuvant radiotherapy and concomitant chemotherapy. Glioblastoma growth is characterized by a high motility of tumour cells, their resistance to both chemo/radio-therapy, apoptosis inhibition leading to failure of conventional therapy. Cancer Stem Cells (CSCs), identified in GBM as well as in many other cancer types, express the membrane antigen prominin-1 (namely CD133). These cells and normal Neural Stem Cells (NSC) share surface markers and properties, i.e. are able to self-renew and differentiate into multiple cell types. Stem cell self-renewal depends on microenvironmental cues, including Extracellular Matrix (ECM) composition and cell types. Therefore, the role of microenvironment needs to be evaluated to clarify its importance in tumour initiation and progression through CSCs. The specific microenvironment of CSCs was found to mimic in part the vascular niche of normal stem cells. The targeting of GMB CSCs may represent a powerful treatment approach. Lastly, in GBM patients cancer-initiating cells contribute to the profound immune suppression that in turn correlated with CSCs STAT3 (CD133 + ). Further studies of microenvironment are needed to better understand the origin of GMB/GBM CSCs and its immunosuppressive properties.

Pluripotent plasticity of stem cells and liver repopulation.

Different types of stem cells have a role in liver regeneration or fibrous repair during and after several liver diseases. Otherwise, the origin of hepatic and/or extra-hepatic stem cells in reactive liver repopulation is under controversy. The ability of the human body to self-repair and replace the cells and tissues of some organs is often evident. It has been estimated that complete renewal of liver tissue takes place in about a year. Replacement of lost liver tissues is accomplished by proliferation of mature hepatocytes, hepatic oval stem cells differentiation, and sinusoidal cells as support. Hepatic oval cells display a distinct phenotype and have been shown to be a bipotential progenitor of two types of epithelial cells found in the liver, hepatocytes, and bile ductular cells. In gastroenterology and hepatology, the first attempts to translate stem cell basic research into novel therapeutic strategies have been made for the treatment of several disorders, such as inflammatory bowel diseases, diabetes mellitus, celiachy, and acute or chronic hepatopaties. In the future, pluripotent plasticity of stem cells will open a variety of clinical application strategies for the treatment of tissue injuries, degenerated organs. The promise of liver stem cells lie in their potential to provide a continuous and readily available source of liver cells that can be used for gene therapy, cell transplant, bio-artificial liver-assisted devices, drug toxicology testing, and use as an in vitro model to understand the developmental biology of the liver.

Iron metabolism markers and haptoglobin phenotypes in susceptibility to HSV-1 or/and HSV-2 lesion relapses.

Different haptoglobin (Hp) phenotypes play a role in several pathologic processes including infectious diseases. In order to evaluate the role of iron storage and metabolism in susceptibility to herpetic manifestations, we studied the frequency of the Hp phenotypes and iron metabolism in patients affected by H. Simplex virus 1 or 2 (HSV-1 or HSV-2), compared with controls. Hp phenotype and iron metabolism were determined in 100 patients with recurrent HSV-1 or HSV-2 manifestations during the relapses, and in 110 healthy subjects. The frequencies of the three Hp phenotypes in the patient group compared to the control group were 18% versus 14.5% p = NS for Hp 1.1, 25% versus 40% p = 0.03 for Hp 2.2 and 57% versus 45.5% p = NS for Hp 2.1. All iron metabolism parameters tested showed significant differences between patients and controls; haemoglobin (Hb), ferritin, and serum iron were lower, while transferrin was higher in the patients than in controls. Reductions in iron availability may be a risk factor for relapsing lesions of HSV-1 or HSV-2. Hp 2.2 phenotype may offer some protection against the recurrence of Herpes labialis or genitalis manifestations.

Role of iron metabolism and oxidative damage in postmenopausal bone loss.

It has been suggested that iron-deficient rats have lower bone mass than iron-replete animals, but a clear association between bone and iron repletion has not been demonstrated in humans. A growing body of evidences also suggests a relation between lipid oxidation and bone metabolism and between iron metabolism and LDL oxidation. Iron availability to cells also depends on haptoglobin (Hp) phenotypes. Hp has also important antioxidant properties according to its phenotype, hence we evaluate whether Hp phenotype could influence bone density, iron metabolism and lipid oxidation. This cross-sectional study enrolled 455 postmenopausal women affected by osteoporosis (260) or not (195). Bone mineral density, markers of bone and iron metabolism, levels of oxidized LDL (oxLDL) and Hp phenotype were measured in all the subjects. Hp 1.1 and 2.2 frequency was higher and Hp 2.1 was lower in the patients with fragility fractures (80) compared with the controls. We therefore evaluate different Hp phenotypes as risk or protective factors against fragility fracture: Hp 2.1 is a protective factor against fracture while 1.1 is an important and 2.2 a moderate risk factor for fragility fractures. Lower serum iron was associated with elevated transferrin in patients with Hp 1.1; moreover patients had relative iron deficiency compared with the controls and fractured patients had higher level of oxLDL. We found that both iron metabolism and oxLDL varies according to Hp phenotypes and are predictive of bone density. Our data indicate that Hp 2.1 is a protective factor for fragility fractures, depending on its role on iron metabolism and its antioxidant properties.

Pre-eclampsia is associated with Helicobacter pylori seropositivity in Italy.

OBJECTIVES: Pre-eclampsia (PE) is characterized by an excess of inflammation and endothelial dysfunction. Helicobacter pylori (H. pylori) causes chronic inflammatory changes and endothelial damage. We investigated the prevalence of seropositivity for IgG against H. pylori and cytotoxin-associated antigen A (CagA) in PE patients and the presence of H. pylori DNA in their placentas. METHODS: We tested 47 pregnant women with PE and 47 with uneventful pregnancies for serum antibodies against H. pylori (enzyme immunoassays) and CagA protein (immunoblot assays). In 20 of them (10 normal and 10 PE) we assessed the presence, in the placenta, of H. pylori DNA by means of nested polymerase chain reaction (PCR). The odds ratios (OR) and 95% confidence intervals (CI), adjusted for parity, were calculated using logistic regression analysis to assess the risk of PE associated with H. pylori infection. RESULTS: Helicobacter pylori seropositivity frequency was higher in mothers with PE (51.1%) compared to women with uneventful pregnancy (31.9%) (OR, 2.668; 95% CI, 1.084-6.566; P = 0.033). The difference was even greater for CagA seropositivity (80.9 and 14.9%, respectively) (OR, 26.035; 95% CI, 8.193-82.729; P < 0.001). All placentas were negative for H. pylori DNA. CONCLUSIONS: Helicobacter pylori, and especially strains carrying the CagA gene, may contribute to the inflammatory mechanisms involved in the pathogenesis of PE.

Stem cells: an alternative to organ transplantation in chronic, degenerative and infectious diseases?

Even in the absence of damage or illness mature animals need billions of new cells every single day of their lives in order to survive and renew circulating blood cells and intestinal and skin lining. This task is accomplished by undifferentiated cells residing in most adult organs. These cells are designated adult stem cells (ASC) since they represent the adult counterpart, present in almost every organ, of the embryonal stem cells (ES) from which the entire human body develops. Scientists first hypothesized the existence of stem cells over a century ago, and haematopoietic stem cells (HSC) have been exploited for the therapy of human diseases for two decades. Other types of stem cells also circulating in the bloodstream have been described. We briefly describe the potential uses of each of these types of cells, including autologous circulating stem cells, for disease therapy and in particular for the possible reversal of liver failure due to chronic hepatitis and/or cirrhosis.

Cell surface-associated Tat modulates HIV-1 infection and spreading through a specific interaction with gp120 viral envelope protein.

Human immunodeficiency virus-1 (HIV-1) Tat, a nuclear transactivator of viral gene expression, has the unusual property of being released by infected cells. Recent studies suggest that extracellular Tat is partially sequestered by heparan sulfate proteoglycans. As a consequence, Tat is concentrated on the cell surface and protected from proteolytic degradation, thus remaining in a biologically active form. We show that Tat binds the surfaces of both HIV-1-infected and surrounding uninfected cells. We provide evidence for a specific interaction between Tat and the HIV-1 glycoprotein 120 (gp120) envelope protein, which enhances virus attachment and entry into cells. We map the interacting sites of both Tat and gp120 and show that synthetic peptides mimicking the gp120 site inhibit HIV-1 infection. Our data demonstrate that membrane-associated Tat is a novel modulator of virus entry and suggest that the Tat-gp120 interaction represents a critical step in HIV-1 spreading during the course of infection.

Interleukin-18 enhances HIV-1 production in a human chronically-infected T cell line (H9-V).

Interleukin-18 (IL-18) is a recently identified immunoregulatory cytokine expressed by activated macrophages, that induces production of interferon-gamma (IFN-gamma) and Th-1 development. Recently some investigators reported controversial in vitro data on IL-18 stimulation of HIV-1 replication in several cell lines. In the present study the effect of IL-18 on HIV replication in a human chronically HIV-1-infected lymphocytic T cell line (H9-V) was investigated. HIV-1 replication was determined by an immunoassay method in order to evaluate the content of p24 antigen in the cell culture supernatants. Stimulation of H9-V cells with IL-18 resulted in increased production of p24, especially at concentrations of 0.01 microg ml(-1) and 0.10 microg ml(-1). Moreover a significant and persistent IL-18 stimulation of HIV-1 replication was observed at a concentration of 0.01 microg ml(-1) during a 7-day period. Pre-treatment of IL-18 with a specific neutralizing monoclonal antibody significantly reduced HIV-1 replication. These experiments show that IL-18 promotes the increase of HIV-1 replication in human chronically-infected lymphocytic T cells and confirm the role of IL-18 as a proimflammatory cytokine in stimulating and maintaining HIV-1 replication during the course of the disease. In a successive set of experiments, since one of the main activities of IL-18 is the induction of IFN-gamma, we evaluated the effect of this biological modifier on H9-V cells. In particular, IFN-gamma shows a significant effect on cell replication and on reduction of CD4 and CD71 surface expression.

Impaired macrophage phagocytosis of apoptotic neutrophils in patients with human immunodeficiency virus type 1 infection.

Dysfunction of neutrophils (polymorphonuclear leukocytes [PMNL]) and macrophagic cells occurs as a consequence of human immunodeficiency virus type 1 (HIV-1) infection. Macrophages contribute to the resolution of early inflammation ingesting PMNL apoptotic bodies. This study investigated macrophage ability to phagocytose PMNL apoptotic bodies in patients with HIV-1 infection in comparison with uninfected individuals and the effect of HIV Nef protein on apoptotic body phagocytosis to determine if phagocytic activity is impaired by HIV infection. Monocytes/macrophages were isolated from 10 HIV-1-infected patients and from five healthy volunteers, whereas PMNL were isolated from healthy volunteers. Macrophage phagocytosis of apoptotic PMNL was determined by staining of apoptotic bodies with fluorescein-conjugated concanavalin A or with fluorescein-labeled phalloidin. Our data show significant impairment of PMNL apoptotic body macrophage phagocytosis in subjects with HIV-1 infection presenting a concentration of CD4(+) T lymphocytes of >200/mm(3) and in particular in those with <200 CD4(+) T lymphocyte cells/mm(3). In addition, HIV-1 recombinant Nef protein is able to decrease phagocytosis of apoptotic PMNL from normal human macrophages in a dose-dependent manner. The results of our study suggest that impaired macrophage phagocytosis of PMNL apoptotic bodies may contribute to the persistence of the inflammatory state in HIV-infected subjects, especially during opportunistic infections that are often favored by defective phagocytic activity.