Anti-Obesity and Anti-Inflammatory Effects of Novel Carvacrol Derivatives on 3T3-L1 and WJ-MSCs Cells

(1) Background: Obesity, a complex metabolic disease resulting from an imbalance between food consumption and energy expenditure, leads to an increase in adipocytes and chronic inflammatory conditions. The aim of this paper was to synthesize a small series of carvacrol derivatives (CD1-3) that are able to reduce both adipogenesis and the inflammatory status often associated with the progression of the obesity disease. (2) Methods: The synthesis of CD1-3 was performed using classical procedures in a solution phase. Biological studies were performed on three cell lines: 3T3-L1, WJ-MSCs, and THP-1. The anti-adipogenic properties of CD1-3 were evaluated using western blotting and densitometric analysis by assessing the expression of obesity-related proteins, such as ChREBP. The anti-inflammatory effect was estimated by measuring the reduction in TNF-α expression in CD1-3-treated THP-1 cells. (3) Results: CD1-3—obtained through a direct linkage between the carboxylic moiety of anti-inflammatory drugs (Ibuprofen, Flurbiprofen, and Naproxen) and the hydroxyl group of carvacrol—have an inhibitory effect on the accumulation of lipids in both 3T3-L1 and WJ-MSCs cell cultures and an anti-inflammatory effect by reducing TNF- α levels in THP-1 cells. (4) Conclusions: Considering the physicochemical properties, stability, and biological data, the CD3 derivative—obtained by a direct linkage between carvacrol and naproxen—resulted in the best candidate, displaying anti-obesity and anti-inflammatory effects in vitro.

Peptides Regulating Proliferative Activity and Inflammatory Pathways in the Monocyte/Macrophage THP-1 Cell Line

This study evaluates the effects of five different peptides, the Epitalon^® tetrapeptide, the Vilon^® dipeptide, the Thymogen^® dipeptide, the Thymalin^® peptide complex, and the Chonluten^® tripeptide, as regulators of inflammatory and proliferative processes in the human monocytic THP-1, which is a human leukemia monocytic cell line capable of differentiating into macrophages by PMA in vitro. These peptides (Khavinson Peptides^®), characterized by Prof. Khavinson from 1973 onwards, were initially isolated from animal tissues and found to be organ specific. We tested the capacity of the five peptides to influence cell cultures in vitro by incubating THP-1 cells with peptides at certain concentrations known for being effective on recipient cells in culture. We found that all five peptides can modulate key proliferative patterns, increasing tyrosine phosphorylation of mitogen-activated cytoplasmic kinases. In addition, the Chonluten tripeptide, derived from bronchial epithelial cells, inhibited in vitro tumor necrosis factor (TNF) production of monocytes exposed to pro-inflammatory bacterial lipopolysaccharide (LPS). The low TNF release by monocytes is linked to a documented mechanism of TNF tolerance, promoting attenuation of inflammatory action. Therefore, all peptides inhibited the expression of TNF and pro-inflammatory IL-6 cytokine stimulated by LPS on terminally differentiated THP-1 cells. Lastly, by incubating the THP1 cells, treated with the peptides, on a layer of activated endothelial cells (HUVECs activated by LPS), we observed a reduction in cell adhesion, a typical pro-inflammatory mechanism. Overall, the results suggest that the Khavinson Peptides^® cooperate as natural inducers of TNF tolerance in monocyte, and act on macrophages as anti-inflammatory molecules during inflammatory and microbial-mediated activity.

The Epithelial-to-Mesenchymal Transition as a Possible Therapeutic Target in Fibrotic Disorders

Fibrosis is a chronic and progressive disorder characterized by excessive deposition of extracellular matrix, which leads to scarring and loss of function of the affected organ or tissue. Indeed, the fibrotic process affects a variety of organs and tissues, with specific molecular background. However, two common hallmarks are shared: the crucial role of the transforming growth factor-beta (TGF-β) and the involvement of the inflammation process, that is essential for initiating the fibrotic degeneration. TGF-β in particular but also other cytokines regulate the most common molecular mechanism at the basis of fibrosis, the Epithelial-to-Mesenchymal Transition (EMT). EMT has been extensively studied, but not yet fully explored as a possible therapeutic target for fibrosis. A deeper understanding of the crosstalk between fibrosis and EMT may represent an opportunity for the development of a broadly effective anti-fibrotic therapy. Here we report the evidences of the relationship between EMT and multi-organ fibrosis, and the possible therapeutic approaches that may be developed by exploiting this relationship.

A Method to Study the C924T Polymorphism of the Thromboxane A2 Receptor Gene

The thromboxane A2 receptor (TBXA2R) gene is a member of the G-protein coupled superfamily with seven-transmembrane regions. It is involved in atherogenesis progression, ischemia, and myocardial infarction. Here we present a methodology of patient genotyping to investigate the post-transcriptional role of the C924T polymorphism (rs4523) situated at the 3' region of the TBXA2 receptor gene. This method relies on DNA extraction from whole blood, polymerase chain reaction (PCR) amplification of the TBXA2 gene portion containing the C924T mutation, and identification of wild type and/or mutant genotypes using a restriction digest analysis, specifically a restriction fragment length polymorphism (RFLP) on agarose gel. In addition, the results were confirmed by sequencing the TBXA2R gene. This method features several potential advantages, such as high efficiency and the rapid identification of the C924T polymorphism by PCR and restriction enzyme analysis. This approach allows a predictive study for plaque formation and atherosclerosis progression by analyzing patient genotypes for the TBXA2R C924T polymorphism. Application of this method has the potential to identify subjects who are more susceptible to atherothrombotic processes, in particular subjects in a high-risk, aspirin-treated group.

Psychobiome Feeding Mind: Polyphenolics in Depression and Anxiety

Recently gut bacterial populations seem to be involved in many functions and in the pathogenesis of several medical conditions. Traditionally the intestinal microbiome has been recognized to play an important role in metabolizing food compounds in simpler chemical structures for the absorption of different nutrients, and in maintenance control of gastrointestinal pathogens species. Bacterial populations are implicated in a complicated network of interactions within the immune system, epithelial cells local endocrine system, that affects the peripheral and the central nervous system, via blood circulation. Microbiome influencing the mind via immune, endocrine and metabolic signalling, is able to exert some clinical effects in different mental diseases. It releases endocrine substances through several pathways involved in the modulation of neuroinflammation and production of several neurotrasmitter precursors. It has recently been named psychobiome. It is known that phenolic compounds are able to influence microbiome proliferation and to exert several roles, especially regarding neuroinflammation in depressive and anxious behaviour. The clinical effects are reported in the literature. The aim of this study is to highlight the interaction between polyphenols and microbiota- gut-brain axis.

Metabolic Alterations, Aggressive Hormone-Naïve Prostate Cancer and Cardiovascular Disease: A Complex Relationship

Background: Epidemiological studies suggest a possible relationship between metabolic alterations, cardiovascular disease and aggressive prostate cancer, however, no clear consensus has been reached. Objective: The aim of the study was to analyze the recent literature and summarize our experience on the association between metabolic disorders, aggressive hormone-naïve prostate cancer and cardiovascular disease. Method: We identified relevant papers by searching in electronic databases such as Scopus, Life Science Journals, and Index Medicus/Medline. Moreover, we showed our experience on the reciprocal relationship between metabolic alterations and aggressive prostate cancer, without the influence of hormone therapy, as well the role of coronary and carotid vasculopathy in advanced prostate carcinoma. Results: Prostate cancer cells have an altered metabolic homeostatic control linked to an increased aggressivity and cancer mortality. The absence of discrimination of risk factors as obesity, systemic arterial hypertension, diabetes mellitus, dyslipidemia and inaccurate selection of vascular diseases as coronary and carotid damage at initial diagnosis of prostate cancer could explain the opposite results in the literature. Systemic inflammation and oxidative stress associated with metabolic alterations and cardiovascular disease can also contribute to prostate cancer progression and increased tumor aggressivity. Conclusions: Metabolic alterations and cardiovascular disease influence aggressive and metastatic prostate cancer. Therefore, a careful evaluation of obesity, diabetes mellitus, dyslipidemia, systemic arterial hypertension, together with a careful evaluation of cardiovascular status, in particular coronary and carotid vascular disease, should be carried out after an initial diagnosis of prostatic carcinoma.

The Impact of Metabolic Syndrome and Its Components on Female Sexual Dysfunction: A Narrative Mini-Review

Background

The impact of metabolic syndrome on female sexual dysfunction received modest consideration in clinical practice. The aim of the research was to analyze the international literature to determine the relationship between the metabolic syndrome, its components and female sexual disorders.

Methods

We identified relevant full-length papers by electronic databases as Index Medicus/Medline, Scopus, Life Science Journals, from 2005 to the present. Studies were searched using the following as search query: metabolic syndrome, female sexual dysfunction, obesity, systemic arterial hypertension, diabetes mellitus, dyslipidemia.

Results

Women with metabolic syndrome showed higher prevalence of sexual inactivity and low sexual desire, orgasm and satisfaction respect to women without metabolic syndrome. Particularly metabolic components as diabetes mellitus, dy-slipidemia, systemic arterial hypertension were strongly associated with lower sexual desire, activity and Female Sexual Function Index total score. In contrast, other studies showed no relationship.

Conclusion

Our study showed that in the clinical evaluation of women with metabolic syndrome routine inquiring about female sexual dysfunction should be recommended to ameliorate sexual function and quality of life. However more prospective and longitudinal studies on the sexual effects of metabolic syndrome should also be suggested to know the factors related to women's sexuality better.

Carvacrol reduces adipogenic differentiation by modulating autophagy and ChREBP expression

Objective

Obesity is the result of white adipose tissue accumulation where excess of food energy is stored to form triglycerides. De novo lipogenesis (DNL) is the continuous process of new fat production and is driven by the transcription factor ChREBP. During adipogenesis, white adipocytes change their morphology and the entire cell volume is occupied by one large lipid droplet. Recent studies have implicated an essential role of autophagy in adipogenic differentiation, cytoplasmic remodelling and mitochondria reorganization. The phenolic monoterpenoid carvacrol (2-methyl-5-[1-methylethyl]phenol), produced by numerous aromatic plants, has been shown to reduce lipid accumulation in murine 3T3-L1 cells during adipogenic differentiation by modulating genes associated with adipogenesis and inflammation. Therefore, the aim of this study was to evaluate whether carvacrol could affect autophagy and ChREBP expression during adipogenic differentiation.

Methods

The study was carried on by using the murine 3T3-L1 and the human WJ-MSCs (Wharton’s jelly-derived mesenchymal stem cells) cell lines. Cells undergoing adipogenic differentiation were untreated or treated with carvacrol. Adipogenic differentiation was assessed by analyzing cellular lipid accumulation with Oil-Red O staining and by ultrastructural examination with TEM. Autophagy was evaluated by western immunoblotting of autophagy markers LC3B and p62/SQSTM and by ultrastructural examination of autophagic bodies. Autophagic flux was evaluated by using autophagy inhibitor cloroquine (CQ). ChREBP expression levels was assessed by both western blotting and immunoelectron microscopy and ChREBP activity by analysis of adipogenic target genes expression.

Results

We found that carvacrol reduced adipogenic differentiation of about 40% and 30% in, respectively, 3T3-L1 and in WJ-MSCs cells. The effect of carvacrol on adipogenic differentiation correlated with both reduction of autophagy and reduction of ChREBP expression.

Conclusion

The results support the notion that carvacrol, through its effect on autophagy (essential for adipocyte maturation) and on ChREBP activity, could be used as a valuable adjuvant to reduce adipogenic differentiation.

Platelet Activation and Platelet-erythrocyte Aggregates in End-stage Renal Disease Patients on Hemodialysis

Activated platelets may engage in dynamic interplay with other blood cells. We examined the evidence for platelet activation and the formation of platelet-erythrocyte aggregates in chronic hemodialysis patients. Circulating activated platelets (P-selectin/CD63-positive platelets) were higher than normal controls (p <0.001) and further increased during hemodialysis sessions, the increase being higher when patients were dialyzed with cellulosic than with synthetic membranes. We found direct evidence of uremic platelet-erythrocyte adherence in vitro and increased levels of circulating platelet-erythrocyte aggregates in dialysis patients, which represents a new observation in uremia. Platelet-erythrocyte aggregates were subject to further increase during hemodialysis, and again higher levels were found with cellulosic than synthetic membranes. This phenomenon was reproduced in vitro by both ADP and PAF, but not by either complement factor C3a or by heparin concentrations corresponding to those used for clinical hemodialysis. We conclude that platelet-erythrocyte aggregates occur in hemodialysis patients probably owing to a primary platelet activation mechanism.

Cytokine expression profile and blood parameter evaluation of patients undergoing cardiac surgery

Cardiac surgery is accompanied by an important immune response that is poorly understood. This inflammatory response is caused by several stimuli: surgical trauma, cardiopulmonary bypass apparatus, aortic-cross clamping, reperfusion injury and hypothermia. The aim of the present study is to investigate the cytokine level profile involved in the inflammatory pathway of patients undergoing cardiac surgery. One hundred and two patients undergoing elective cardiac surgery utilizing cardiopulmonary bypass (CPB) apparatus were enrolled in the study. In the hematological and biochemical profiles investigated, we observed a significant increase of WBC and blood glucose concentration and a strong decrease of RBC, HB, HCT and PLT 24 h post-surgery compared to baseline and immediately after surgery groups. Furthermore, we found a modulation of cytokine levels mostly for IL-10 and an increase of IL-6, detected at 6 h post-surgery, IL-8 at 6 and 24 h, and TNFα only at 24 h post-surgery. In conclusion, these findings evidence a time course profile on cytokine levels and a balance between pro- and anti-inflammatory cytokine activation during and after cardiac surgery. In fact, IL-6 and IL-10, a pro- and an anti-inflammatory cytokine, respectively, increased immediately after surgery. The plasma level of TNF-α could be inhibited by the high concentration of IL-10 up to 6 h post-surgery. An IL-10 reduction at baseline level, after 24 h post-surgery, could explain a rise of TNF-α plasma concentration. On the other hand, considering the dual role of IL-6 on inflammation acting both as an activator of inflammatory cascade or an anti-inflammatory agent, the increased IL-6 levels 24 h after surgery could be related to the negative feedback action on TNFα activity.

Mast cell in innate immunity mediated by proinflammatory and antiinflammatory IL-1 family members

Innate immunity consists of physical and chemical barriers which provide the early defense against infections. Innate immunity orchestrates the defense of the host with cellular and biochemical proteins. Mast cells (MCs) are involved in innate and adaptive immunity and are the first line of defense which generates multiple inflammatory cytokines/chemokines in response to numerous antigens. MC-activated antigen receptor Fc-RI provokes a number of important biochemical pathways with secretion of numerous vasoactive, chemoattractant and inflammatory compounds which participate in allergic and inflammatory diseases. MCs can also be activated by Th1 cytokines and generate pre-formed and de novo inflammatory mediators, including TNF. IL-37 is an anti-inflammatory cytokine which binds IL-18R-alpha chain and reduces the production of inflammatory IL-1 family members. IL-37 down-regulates innate immunity by inhibiting macrophage response and its accumulation and reduces the cytokines that mediate inflammatory diseases. Here, we discuss the relationship between MCs, innate immunity, and pro-inflammatory and anti-inflammatory cytokines.

Activation and inhibition of adaptive immune response mediated by mast cells

Adaptive immune response plays an important role against bacteria and parasites, a reaction that also involves mast cell (MC) activation which participates in innate and adaptive immunity. In allergic reactions there is a TH2 immune response with generation of allergen-specific IgE antibodies. In MCs, IgE cross-link FcRI high affinity receptor and activate tyrosine kinase proteins, leading to stimulation of NF-κB and AP-1 resulting in the release of a number of cytokines/chemokines and other compounds. Through their proteolytic pathways, MCs may process the antigen for presentation to CD4+ cells which release TH2 cytokines and growth factors, which play an important role in asthma, allergy, anaphylaxis and inflammation. Thus, MCs can contribute to adaptive immunity. MCs may also be activated though the TLR-dependent pathway which is controlled by several proteins including myeloid differentiation factor 88 (MyD88) which can be inhibited by interleukin (IL)-37. Here, we describe the participation of MCs in adaptive immunity and inflammation, an effect that may be inhibited by IL-37.

Effect of low energy light irradiation by light emitting diode on U937 cells

Photobiomodulation (PBM) can induce a set of different biological modulators either in vitro or in vivo. Experimental evidence has highlighted the role of light effects on the mechanisms related to inflammation, apoptosis and autophagy. The goal of this project was the evaluation of PBM on U937, an established cell line of histiocytic lymphoma origin. Several aspects of modulation of proinflammatory pathways were analyzed and autophagic and proapoptotic mechanisms related to low laser light exposure of cells were studied. As a source of low energy light emission, we used an NIR-LED device, characterized by an 880 nm-wavelength as light source. Flow cytometry analysis was performed on supernatants of controls and treated U937 cells to detect inflammatory cytokine levels. In order to evaluate NF-kB and caspase3 expressions, Western blot analysis was performed according to standard procedures. In this report, we show the effect of PBM on a monocyte/macrophage established tumor cell line (U-937). We demonstrate that LED exposure, in the presence or absence of lipopolysaccharide (LPS), activates cell degranulation, increased expression of Interleukin-8 (IL-8) and modulation of beta galactosidase activity. Evidence shows that the well-known pro-inflammatory nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) and the apoptotic marker (caspase3/cleaved-caspase3 ratio) are up-regulated in response to a proinflammatory biochemical pathway.

Helicobacter pylori ATCC 43629/NCTC 11639 Outer Membrane Vesicles (OMVs) from Biofilm and Planktonic Phase Associated with Extracellular DNA (eDNA)

Helicobacter pylori persistence is associated with its capacity to develop biofilms as a response to changing environmental conditions and stress. Extracellular DNA (eDNA) is a component of H. pylori biofilm matrix but the lack of DNase I activity supports the hypothesis that eDNA might be protected by other extracellular polymeric substances (EPS) and/or Outer Membrane Vesicles (OMVs), which bleb from the bacteria surface during growth. The aim of the present study was to both identify the eDNA presence on OMVs segregated from H. pylori ATCC 43629/NCTC 11639 biofilm (bOMVs) and its planktonic phase (pOMVs) and to characterize the physical-chemical properties of the OMVs. The presence of eDNA in bOMVs and pOMVs was initially carried out using DNase I-gold complex labeling and Transmission Electron Microscope analysis (TEM). bOMVs and pOMVs were further isolated and physical-chemical characterization carried out using dynamic light scattering (DLS) analysis. eDNA associated with OMVs was detected and quantified using a PicoGreen spectrophotometer assay, while its extraction was performed with a DNA Kit. TEM images showed that eDNA was mainly associated with the OMV membrane surfaces; while PicoGreen staining showed a four-fold increase of dsDNA in bOMVs compared with pOMVs. The eDNA extracted from OMVs was visualized using gel electrophoresis. DLS analysis indicated that both planktonic and biofilm H. pylori phenotypes generated vesicles, with a broad distribution of sizes on the nanometer scale. The DLS aggregation assay suggested that eDNA may play a role in the aggregation of OMVs, in the biofilm phenotype. Moreover, the eDNA associated with vesicle membrane may impede DNase I activity on H. pylori biofilms. These results suggest that OMVs derived from the H. pylori biofilm phenotype may play a structural role by preventing eDNA degradation by nucleases, providing a bridging function between eDNA strands on OMV surfaces and promoting aggregation.

A novel biotechnology product for the degradation of biofilm-associated polysaccharides produced by Streptococcus mutans

In this study we evaluated the activity of ABR preparation, a first-in-class agent obtained through fermentation process by genetically unmodified Bacillus spp., in breaking down polysaccharide produced by Streptococcus mutans, primary coloniser of tooth surface and abundant in dental biofilms. Our results showed that ABR preparation is able in degrading sugars formed by S. mutans, both in broth culture and onto teeth surface. Its activity is not influenced by the presence of saliva, commercial mouthwashes or oral disinfectants. ABR preparation has the potential to remove preformed plaque and counteract its development, thus offering conservative control of gingival and periodontal disease.

Cyanidin reduces preadipocyte differentiation and relative ChREBP expression

Adipogenesis is a continuous process even in adult adipose tissue for the presence of preadipocytes that, when subjected to appropriate stimuli can proliferate and differentiate. ChREBP, the essential transcription factor for lipogenesis, is expressed in all tissues, but mainly in lipogenic organs. In this study, we focused on ChREBP expression during preadipocytes differentiation. Since it was found that cyanidin-3 reduces body weight in mice even in the presence of a high-fat diet, by decreasing levels of blood glucose and by improving insulin sensitivity, we studied the effect of this substance on adipogenic differentiation. For this purpose we used preadipocytes obtained from subcutaneous and visceral human adipose explant tissue, characterized and stimulated to differentiate in selective media. On cytofluorimetric analysis these cells showed mesenchymal markers (CD29, CD90, CD44), whereas they were negative for hematopoietic markers (CD45, CD10, CD117,CD31). ChREBP expression levels were quantified by immunoelectron-microscopy and western blotting analysis. In this report we show that ChREBP is expressed in preadipocytes (both nuclear and cytoplasmic compartments); the cytoplasmic level of ChREBP increased by 50 percent on day seven of differentiation into mature adipocytes. Cyanidin reduced differentiation by 20 percent (as evaluated by red oil O staining) and the expression of ChREBP. In addition, cyanidin-treated cells showed abnormal morphology, a square shape with irregular size, probably due to the fact that cyanidin may interfere with the extracellular matrix. These findings suggest that dietary cyanidin, may have inhibitory effects on adipogenesis.

Vascular endothelial growth factor enhances in vitro proliferation and osteogenic differentiation of human dental pulp stem cells

Mesenchymal stem cells (MSC), isolated from dental tissues, are largely studied for future application in regenerative dentistry. In this study, we used MSC obtained from human dental pulp (DPSC) of normal impacted third molars that, when cultured in lineage-specific inducing media, differentiate into osteoblasts and adipocytes (evaluated by Alizarin Red S and Red Oil O stainings, respectively), thus showing a multipotency. We confirmed that DPSC, grown under undifferentiating conditions, are negative for hematopoietic (CD45, CD31, CD34, CD144) and positive for mesenchymal (CD29, CD90, CD105, CD166, CD146, STRO-1) markers, that underwent down-regulation when cells were grown in osteogenic medium for 3 weeks. In this condition, they also exhibit an increase in the expression of osteogenic markers (RUNX-2, alkaline phosphatase) and extracellular calcium deposition, whereas the expression of receptors (VEGFR-1 and -2) for vascular endothelial growth factors (VEGF) and related VEGF binding proteins was similar to that found in undifferentiated DPSC. Exposure of DPSC growing under undifferentiating or osteogenic conditions to VEGF-A165 peptide (10-40 ng/ml) for 8 days dose- and time-dependently increased the number of proliferating cells without inducing differentiation towards endothelial lineage, as evaluated by the lack of expression of specific markers (CD31, CD34, CD144). Additionally, exposure of DPSC cultured in osteogenic medium to VEGF-A165 for a similar period enhanced cell differentiation towards osteoblasts as evaluated after 14 and 21 days by Alizarin Red S staining and alkaline phosphatase activity quantification. These findings may have clinical implications possibly facilitating tissue repair and remodeling.

Cystic fibrosis transmembrane conductance regulator (CFTR) expression in human platelets: impact on mediators and mechanisms of the inflammatory response

Inflammatory lung disease is a primary cause of morbidity and mortality in cystic fibrosis (CF). Mechanisms of unresolved acute inflammation in CF are not completely known, although the involvement of cystic fibrosis transmembrane conductance regulator (CFTR) in nonrespiratory cells is emerging. Here we examined CFTR expression and function in human platelets (PLTs) and found that they express a biologically active CFTR. CFTR blockade gave an ∼50% reduction in lipoxin A(4) (LXA(4)) formation during PLT/polymorphonuclear leukocytes (PMN) coincubations by inhibiting the lipoxin synthase activity of PLT 12-lipoxygenase. PLTs from CF patients generated ∼40% less LXA(4) compared to healthy subject PLTs. CFTR inhibition increased PLT-dependent PMN viability (33.0±5.7 vs. 61.2±8.2%; P=0.033), suppressed nitric oxide generation (0.23±0.04 vs. 0.11±0.002 pmol/10(8) PLTs; P=0.004), while reducing AKT (1.02±0.12 vs. 0.71±0.007 U; P=0.04), and increasing p38 MAPK phosphorylation (0.650±0.09 vs. 1.04±0.24 U; P=0.03). Taken together, these findings indicate that PLTs from CF patients are affected by the molecular defect of CFTR. Moreover, this CF PLT abnormality may explain the failure of resolution in CF.

Upgraded diagnostic value of Gen-Probe PACE 2 assay for detection of Chlamydia trachomatis infection

In this study, we evaluate the performance of a nucleic acid amplification assay, COBAS AMPLICOR (Roche Molecular systems) (PCR), compared to non-amplified DNA probe assay PACE2 (Gen-Probe Inc.) for the detection of C. trachomatis in a total of 2,916 samples (2,114 females and 802 males) consecutively collected in two different clinical pathology laboratories, over a period of three years. In the females, the endocervical swabs showed a similar range of detection when using the two different methods: out of 1,581 females processed with PACE 2, 1.4% (2005), 0.9% (2006), 0.5% (2007), resulted positive for C. trachomatis; out of 533 females processed with PCR, 1.3% (2005), 1.5% (2006) and 1.2% (2007), resulted positive. However, in the male subjects we found an increased positivity of Chlamydia detection on urethral swabs by using PACE 2: 4.8% (2005), 1.9% (2006) and 2.9% (2007), compared to urine specimen processed by PCR: 1% (2005), 1.4% (2006) and 0% (2007). Even if PCR should be considered a most promising tool for routine diagnosis of Chlamydia infection, Gen Probe allowed us to better identify Chlamydia trachomatis (in 4.8% of urethral swabs compared to urine) leading to a hypothesis that extracellular EB forms of Chlamydia could be absent in urine in persistent infectious.

Bacterial response to the exposure of 50 Hz electromagnetic fields

To investigate the ability of prokaryotic microorganisms to activate strategies in adapting themselves to the environmental stress induced by exposure to extremely low frequency electromagnetic fields (ELF-EMF), cultures of Escherichia coli ATCC 700926 exposed at 50 Hz EMF (0.1, 0.5, 1.0 mT), and the respective sham-exposed controls were studied for: the total and culturable counts, the viability status, the antimicrobial susceptibility pattern, the morphological analysis, the genotypical and transcriptional profile. Exposed samples and controls displayed similar total and culturable counts, whereas an increased cell viability was observed in exposed samples re-incubated for 24 h outside of the solenoid compared to the corresponding controls. An exposure to 50 Hz EMF of 20-120 min produced a significant change of E. coli morphotype with a presence of coccoid cells also aggregated in clusters after re-incubation of 24 h outside of the solenoid. Atypical lengthened bacterial forms were also observed suggesting a probable alteration during cell division. No changes among DNA fingerprintings and some differences in RNA-AFLP analysis were observed for each 50 Hz EMF intensities evaluated. Our results indicate that an exposure to 50 Hz EMF acts as a stressing factor on bacteria which can represent a suitable model to investigate acute and chronic effects related to ELF-EMF exposure.

A New Diagnostic Approach to Better Identify Antiphospholipid Syndrome

Antiphospholipid syndrome is an autoimmune disorder in which the body produces antibodies to its own phospholipids or plasma proteins. Antiphospholipid syndrome (APS) is associated with many pathologies with several clinical manifestations. It can occur as a primary disorder or may be secondary to connective tissue disorder or tumor. Anti-phospholipid antibodies were detected in two categories of patients: in one group with many clinical manifestations (such as thrombotic events, thrombocytopenia and miscarriages) and in the other group with few clinical manifestations. In the first group high levels of IgG and IgA antibodies resulted, in the other group low levels of IgM. The ratio male:female was 1:3.5. Out of the 700 patients examined, 12 resulted positive for anti-cardiolipin (aCL) and aβ2-GPI (affected by APS), and 15 patients positive for aCL (with middle-high values) but negative for aβ2-GPI. At this point, according to the guidelines, we could have stopped examining. Only by continuing diagnostic investigation for these 15 patients has it been possible to observe:2 patients positive for anti-thrombin (important first marker in the diagnosis of venose and arterial thromboses), anti-phosphatidylserine and anti-phosphatidylinositol (markers for cerebral diseases and recurrent miscarriages); 1 patient positive for anti- phosphatidylserine; 1 patient positive for anti-phosphatidylinositol antibody; 1 patient positive for both anti-phosphatidylserine and anti-phosphatidylinositol; 10 patients positive only for anti-cardiolipin. According to the results obtained, and considering that a more accurate investigation permitted to better identify APS syndrome, we propose a new diagnostic procedure.

The association of chronic hepatitis B and myopathy

In two patients with chronic hepatitis B and myopathy, muscle biopsy showed necrosis and scarce inflammatory infiltrates. CD8+ cells surrounded some non-necrotic fibers. Hepatitis B virus (HBV) DNA and antigens were found inside intact muscle fibers. Major histocompatibility complex class I antigens were coexpressed with viral antigens. In one patient, symptoms improved during antiviral therapy. HBV can infect muscle fibers and an immune-mediated response to viral antigens may cause muscle injury.

Expression of glutathioneS-transferase and peptide methionine sulphoxide reductase inOchrobactrum anthropiis correlated to the production of reactive oxygen species caused by aromatic substrates

Peptide methionine sulphoxide reductase (MsrA) and glutathione S-transferases (GSTs) are considered as detoxification enzymes. In the xenobiotics-degrading bacterium Ochrobactrum anthropi the two enzymes are co-induced by toxic concentrations of aromatic substrates such as phenol and 4-chlorophenol. In aerobic organisms, degradation of aromatic substrates by mono- and dioxygenases leads to a generation of oxidative stress that causes the occurrence of reactive oxygen species (ROS). A capillary electrophoretic method, using the intracellular conversion of dihydrorhodamine-123 into rhodamine-123, was developed to measure the content of ROS in the bacteria. The presence of toxic concentrations of the aromatic substrate 4-chlorophenol, an inducer of GST and MsrA, leads to a significant increase in the production of ROS. These results strongly suggest that GST and MsrA enzymes are part of the bacterial defence mechanism against particular oxidative stress conditions. As oxidative stress is known to be present predominantly close to the cytoplasmic membrane, we investigated the subcellular distribution of both MsrA and GST enzymes in this bacterium grown in the presence of 4-chlorophenol. By Western blotting, MsrA and GST was assayed in the cytoplasm as well as in the periplasm. Moreover, immunolocalisation by colloidal gold immunoelectron microscopy identified the two proteins associated with the cell envelope.

Biofilm formation by Stenotrophomonas maltophilia: modulation by quinolones, trimethoprim-sulfamethoxazole, and ceftazidime

We investigated the in vitro effects of seven fluoroquinolones (ciprofloxacin, grepafloxacin, levofloxacin, moxifloxacin, norfloxacin, ofloxacin, and rufloxacin), compared to those of trimethoprim-sulfamethoxazole (SXT) and ceftazidime on total biomass and cell viability of Stenotrophomonas maltophilia biofilm. S. maltophilia attached rapidly to polystyrene, within 2 h of incubation, and then biofilm formation increased over time, reaching maximum growth at 24 h. In the presence of fluoroquinolones at one-half and one-fourth the MIC, biofilm biomass was significantly (P < 0.01) reduced to 55 to 70% and 66 to 76% of original mass, respectively. Ceftazidime and SXT did not exert any activity. Biofilm bacterial viability was significantly reduced by all antibiotics tested at one-half the MIC. At one-fourth the MIC all antibiotics, except levofloxacin, significantly reduced viability. Treatment of preformed biofilms with bactericidal concentrations (500, 100, and 50 micro g/ml) of all fluoroquinolones caused, except for norfloxacin, significant reduction of biofilm biomass to 29.5 to 78.8, 64.1 to 83.6, and 70.5 to 82.8% of original mass, respectively. SXT exerted significant activity at 500 micro g/ml only. Ceftazidime was completely inactive. Rufloxacin exhibited the highest activity on preformed biofilm viability, significantly decreasing viable counts by 0.6, 5.4, and 17.1% at 500, 100, and 50 micro g/ml, respectively. Our results show that (i) subinhibitory (one-half and one-fourth the MIC) concentrations of fluoroquinolones inhibit adherence of S. maltophilia to polystyrene and (ii) clinically achievable concentrations (50 and 100 micro g/ml) of rufloxacin are able to eradicate preformed S. maltophilia biofilm.

Population dynamics in ageing Helicobacter pylori

The aim of this work was to characterize population changes occurring in aged broth cultures of Helicobacter pylori. Experiments were performed using clinical strains cultured immediately after isolation and after multiple subcultures in solid medium. Morphological changes in the ageing bacteria during a 7-day broth culture were analysed by optical and electron microscopy. The expression of the virulence factor, CagA, together with the presence of the cell cycle regulator, cGMP, were also assessed. The transition from bacillary to coccoid forms was the main morphological change observed in freshly isolated bacteria, together with the increase in cGMP from 1 to 2.25 nmoles/mg of proteins within the first 7 days of broth culture. A similar trend of morphological and physiological changes was observed in cells after multiple subcultures in solid medium with a major presence of large cell clusters. The cagA gene product was always expressed in all experimental conditions evaluated. These data show a significant morphological and physiological diversity in fresh, ageing and aged cultures of H. pylori.

Platelet activation and platelet-erythrocyte aggregates in end-stage renal disease patients on hemodialysis

Activated platelets may engage in dynamic interplay with other blood cells. We examined the evidence for platelet activation and the formation of platelet-erythrocyte aggregates in chronic hemodialysis patients. Circulating activated platelets (P-selectin/CD63-positive platelets) were higher than normal controls (p < 0.001) and further increased during hemodialysis sessions, the increase being higher when patients were dialyzed with cellulosic than with synthetic membranes. We found direct evidence of uremic platelet-erythrocyte adherence in vitro and increased levels of circulating platelet-erythrocyte aggregates in dialysis patients, which represents a new observation in uremia. Platelet-erythrocyte aggregates were subject to further increase during hemodialysis, and again higher levels were found with cellulosic than synthetic membranes. This phenomenon was reproduced in vitro by both ADP and PAF, but not by either complement factor C3a or by heparin concentrations corresponding to those used for clinical hemodialysis. We conclude that platelet-erythrocyte aggregates occur in hemodialysis patients probably owing to a primary platelet activation mechanism.

Methionine aminopeptidase-2 regulates human mesothelioma cell survival: role of Bcl-2 expression and telomerase activity

Methionine aminopeptidase-2 (MetAP2) is the molecular target of the angiogenesis inhibitors, fumagillin and ovalacin. Fumagillin can also inhibit cancer cell proliferation, implying that MetAP2 may play a quite complex role in tumor progression. Here, we examined the expression and function of MetAP2 in an in vitro model of human mesothelioma. We found that mesothelioma cells expressed higher MetAP2 mRNA levels than primary normal mesothelial cells. Consistently, fumagillin induced apoptosis, owing to early mitochondrial damage, in malignant, but not in normal mesothelial cells. Transfection of mesothelioma cells with a MetAP2 anti-sense oligonucleotide determined a time-dependent inhibition of cell survival and induced nucleosome formation. Interestingly, mRNA and protein levels of the anti-apoptotic gene bcl-2 as well as telomerase activity were selectively reduced after MetAP2 inhibition in mesothelioma cells, whereas bcl-2 overexpression counteracted the effect of MetAP2 inhibition on telomerase activity and apoptosis. MetAP2 inhibition also increased caspase activity and the caspase inhibitor, zVAD-fmk, prevented fumagillin-induced apoptosis, but it did not alter telomerase activity. These results indicate that MetAP2 is a main regulator of proliferative and apoptotic pathways in mesothelioma cells and suggest that MetAP2 inhibition may represent a potential target for therapeutic intervention in human mesothelioma.

Searching the point of no return in Helicobacter pylori life: necrosis and/or programmed death?

AIMS

Ultrastructural and molecular studies to support the hypothesis of programmed cell death in Helicobacter pylori were conducted.

METHODS AND RESULTS

Evidence of programmed death in H. pylori is provided through electron microscopic detection and cytochemical labelling of electrondense bodies (EDB), containing packaged DNA in coccoid cells, resembling micronuclei of apoptotic eukaryotic cells. This morphological evidence is also supported by DNA cleavage in homogeneous fragments of about 100 base pairs. Programmed cell death was observed in H. pylori cultures at 37 degrees C, with a maximum of 37.5% of EDB coccoid cells after 7 days. The non-permissive temperature of 4 degrees C anticipated this process, with 40% of EDB coccoid forms within 3 days, and it remained substantially unaffected during the observation time of 14 days.

CONCLUSION

In these experiments, deprivation of nutrients and a non-permissive temperature acted as a powerful trigger for programmed cell death.

SIGNIFICANCE AND IMPACT OF THE STUDY

Helicobacter pylori bacterial populations, under stressing stimuli, can respond with programmed cell suicide as a means of species preservation.

Behavior of nucleolar proteins during the course of apoptosis in camptothecin-treated HL60 cells

By means of immunofluorescence and immunoelectron microscopy we have studied the fate of different nucleolar components during the apoptotic process in camptothecin-treated HL60 cells. We have found that RNA polymerase I disappeared while UBF was associated with previously described fibrogranular threaded bodies. In contrast, fibrillarin, C23/nucleolin, and B23/nucleophosmin remained detectable in granular material present amid micronuclei of late apoptotic cells. Double immunolabeling experiments showed colocalization of both C23 and B23 with fibrillarin. Immunoblotting analysis showed that UBF was proteolytically degraded, whereas fibrillarin, C23/nucleolin, and B23/nucleophosmin were not. These results may help explain the presence of anti-nucleolar antibodies seen in various pathological disorders.

Effects of TNF-alpha/colchicine combined treatment on Burkitt lymphoma cells: molecular and ultrastructural changes

Tumour necrosis factor alpha (TNF-alpha) kills Daudi cells (Human Burkitt Lymphoma), inducing either necrosis or apoptosis without DNA fragmentation. Therefore, we were interested in studying the molecular and ultrastructural events occurring when the nucleus is more accessible and cells are blocked in mitosis, following colchicine treatment. In fact, as early as after 1 h treatment a typical ladder pattern was shown by means of DNA gel electrophoresis. In parallel the quantitative analysis of the different morphological patterns observed gave evidence of an increased percentage of primary necrosis after 6 h treatment, and a higher incidence of cells in late apoptosis as well as in secondary necrosis after 24 h treatment. Our findings show that Daudi cells respond to the combined treatment with an increased formation of micronuclei and nuclear alterations which follow a number of early mitochondrial changes and result in enhanced cell death. These data imply that TNF-alpha-induced apoptosis of Daudi cells can be triggered by mitochondrial changes and is somehow related to microtubule organization.

Recovery of Helicobacter pylori ATCC43504 from a viable but not culturable state: regrowth or resuscitation?

Studies were conducted following the formation and characterization of the coccoid morphology of Helicobacter pylori. H. pylori ATCC43504 was incubated in brucella broth plus 2% fetal calf serum at three different temperatures: 37 degrees C, room temperature and 4 degrees C in a microaerophilic environment, and readings were taken at 2, 7, 15, 30 and 45 days. At control times, the total and the viable count, viability tests with tetrazolium salts, and ultrastructural studies were carried out. On solid media, H. pylori became nonculturable after 7 days of incubation at room temperature and 4 degrees C, and after 15 days of incubation at 37 degrees C. At these times of incubation, after subculturing in liquid medium under the same conditions, the growth of H. pylori was detected until the 15th day from cultures incubated at 4 degrees C and until the 30th day from cultures stored at 37 degrees C, and at room temperature. Ultrastructural studies showed a gradual reduction of integrity of bacterial cells that remained stable at 30 and 45 days of incubation: 30% of whole cells of bacteria incubated at 37 degrees C and room temperature and 50% in bacteria incubated at 4 degrees C. The viability of the VNC (viable nonculturable) state was assessed by studying the reduction of tetrazolium salts INT (p-iodonitrophenyl tetrazolium violet) and CTC (cyanoditolyl tetrazolium chloride) to their respective formazans and this was linked to the cellular respiration. At 45 days of incubation, when bacterial regrowth was not observed in solid or in liquid medium, different resuscitation methods were applied to evaluate a possible resuscitation of VNC H. pylori. No significant growth on solid medium was observed.

Human Herpesvirus 7 induces CD4(+) T-cell death by two distinct mechanisms: necrotic lysis in productively infected cells and apoptosis in uninfected or nonproductively infected cells

We have investigated the cytopathic effects induced by the T-lymphotropic human herpesvirus 7 (HHV-7) on the CD4(+) T-lymphoblastoid SupT1 cell line and primary CD4(+) T lymphocytes. Acute in vitro HHV-7 infection induced (1) the formation of giant multinucleated syncytia, which eventually underwent necrotic lysis, and (2) single-cell apoptosis. Both cytopathic effects increased with the progression of infection and were blocked by phosphonoformic acid, a specific inhibitor of herpetic DNA polymerase. Using electron microscopy analysis of various samples, we found that all syncytia contained large amounts of virions and that most of them exhibited clear evidence of necrosis, whereas apoptosis was predominantly observed in single cells. Although empty viral capsids could be identified in the cytoplasm of approximately 25% of single cells exhibiting an apoptotic morphology, mature virions were hardly observed in these cells. In both coculture and cell-free HHV-7 infection experiments, a significant correlation was observed between the degree of single-cell apoptosis, evaluated by quantitative flow cytometry after propidium iodide staining, and the decrease in the total number of viable cells. Moreover, in cell-free infection experiments, apoptosis showed a positive correlation also with the viral load, monitored by quantitative HHV-7 DNA polymerase chain reaction. Thus, it appears that apoptosis occurred predominantly in uninfected bystander cells but not in productively HHV-7-infected cells.

Human herpesvirus 7 induces the down-regulation of CD4 antigen in lymphoid T cells without affecting p56lck levels

In this study, we investigated the fate of the CD4 Ag during infection of CD4+ T cells with the T lymphotrophic human herpesvirus 7 (HHV-7), using the SupT1 lymphoblastoid T cell line as a model system. The following points were established: 1) productive infection with HHV-7 was required to obtain persistent down-modulation of surface CD4 (CD4SURF); 2) at 6 to 9 days postinfection, when approximately 50 to 60% of SupT1 cells still showed a CD4SURF dim positivity, a drastic loss of total CD4 protein was found by either Western blot or immunoprecipitation experiments; 3) a block in CD4 protein production was demonstrated by a radioimmunoprecipitation assay; 4) analysis of the mRNA steady-state levels and transfection studies performed with a plasmid containing the CD4 promoter/enhancer regions in front of the luciferase gene indicated that HHV-7 infection has a suppressive effect on CD4 transcription; 5) both CD4SURF and intracellular CD4 (CD4INTRA) were reduced in HHV-7-infected cells with respect to uninfected controls, but the loss of CD4SURF was more dramatic than that of CD4INTRA; 6) immunogold labeling and electron microscopy demonstrated that CD4INTRA co-localized with HHV-7 Ags within the same subcellular compartments of infected cells; and 7) the total amount of the tyrosine kinase p56lck and tyrosine phosphorylated p56lck levels were unchanged in HHV-7-infected versus uninfected cells.

Human herpesvirus 7 induces the down-regulation of CD4 antigen in lymphoid T cells without affecting p56lck levels

In this study, we investigated the fate of the CD4 Ag during infection of CD4+ T cells with the T lymphotrophic human herpesvirus 7 (HHV-7), using the SupT1 lymphoblastoid T cell line as a model system. The following points were established: 1) productive infection with HHV-7 was required to obtain persistent down-modulation of surface CD4 (CD4SURF); 2) at 6 to 9 days postinfection, when approximately 50 to 60% of SupT1 cells still showed a CD4SURF dim positivity, a drastic loss of total CD4 protein was found by either Western blot or immunoprecipitation experiments; 3) a block in CD4 protein production was demonstrated by a radioimmunoprecipitation assay; 4) analysis of the mRNA steady-state levels and transfection studies performed with a plasmid containing the CD4 promoter/enhancer regions in front of the luciferase gene indicated that HHV-7 infection has a suppressive effect on CD4 transcription; 5) both CD4SURF and intracellular CD4 (CD4INTRA) were reduced in HHV-7-infected cells with respect to uninfected controls, but the loss of CD4SURF was more dramatic than that of CD4INTRA; 6) immunogold labeling and electron microscopy demonstrated that CD4INTRA co-localized with HHV-7 Ags within the same subcellular compartments of infected cells; and 7) the total amount of the tyrosine kinase p56lck and tyrosine phosphorylated p56lck levels were unchanged in HHV-7-infected versus uninfected cells.

ATP depletion inhibits glucocorticoid-induced thymocyte apoptosis

In quiescent thymocytes, mitochondrial de-energization was not correlated to apoptotic death. In fact, thymocytes treated with oligomycin, a highly specific inhibitor of ATP synthase, alone or with atractyloside to block ATP translocation from the cytoplasm, were alive, even if their mitochondria were depolarized, as revealed by flow cytometry after Rhodamine 123 staining. Furthermore, oligomycin was a powerful inhibitor of apoptosis induced in rat thymocytes by dexamethasone and, to a lesser extent, by the calcium ionophore A23187 and etoposide, but was without effect when apoptosis was induced by staurosporine, and increased cell death in mitogen-treated thymocytes. The inhibition of apoptosis was confirmed by morphological criteria, inhibition of inter-nucleosomal DNA fragmentation and inhibition of the loss of membrane integrity. The anti-apoptotic effect of oligomycin in cells treated with A23187 or etoposide was correlated to the inhibition of protein synthesis, while inhibition of apoptosis induced by dexamethasone, already evident at an oligomycin concentration of 10 ng/ml, was instead strictly correlated to the effect exerted on the cellular ATP level. Thymocyte apoptosis triggered by dexamethasone was blocked or delayed by inhibitors of respiratory-chain uncouplers, inhibitors of ATP synthase and antioxidants: a lasting protection from dexamethasone-induced apoptosis was always correlated to a drastic and rapid reduction in ATP level (31-35% of control), while a delay in the death process was characterized by a moderate decrease in ATP (73-82% of control). Oligomycin inhibited the specific binding of radioactive corticosteroid to thymocyte nuclei, confirming the inhibitory effect of ATP depletion on glucocorticoid binding and suggesting that ATP depletion is a common mediator of the anti-apoptotic action of different effectors in glucocorticoid-induced apoptosis. In conclusion, the reported data indicate that ATP may act as a cellular modulator of some forms of apoptosis, depending on the death trigger, and that in quiescent cells the de-energization of mitochondria is not necessarily linked to apoptosis.

Morphological patterns and DNA polymerase regulation in apoptotic HL60 cells

An ultrastructural and functional study was performed during methotrexate (MTX) induced apoptosis on HL-60 leukemia cells. The fine preservation of plasma membrane architecture and organellar components was present until latest apoptotic stages, despite strong nuclear changes. This observation suggests the presence of a residual cell metabolic activity, which is here investigated. DNA agarose gel electrophoresis demonstrated its fragmentation, which was also confirmed in situ by nick translation confocal analysis. Nuclear purification was subsequently performed to investigate DNA polymerase activities. DNA polymerase alpha activity appeared strongly reduced from the early phases of methotrexate treatment, while the rate of DNA polymerase beta synthesis was found to increase progressively along with the time of drug treatment. Low levels of DNA polymerase gamma activity revealed both in control and in treated cells, suggesting the irrelevant involvement of this enzyme in the DNA metabolism of this model. DNA polymerase beta appears thus to be the enzyme preminently correlated to cell attempts to repair the methotrexate-induced DNA damage.

Exogenous human immunodeficiency virus type-1 Tat protein selectively stimulates a phosphatidylinositol-specific phospholipase C nuclear pathway in the Jurkat T cell line

We investigated the effect of extracellular Tat protein of human immunodeficiency virus-type 1 (HIV-1) on the phosphatidylinositol (PI) cycle, which represents a major signal transduction pathway in lymphoid cells. Recombinant Tat, recombinant HIV-1 p24 and cross-linked anti-CD3 monoclonal antibody (mAb) were added in culture for 1-60 min to Jurkat lymphoblastoid CD4+ T cells. The stimulation of T cell receptor by cross-linked anti-CD3 mAb resulted in a rapid increase of the phosphatidylinositol-specific phospholipase C (PI-PLC) activity in whole cell lysates. On the other hand, Tat protein, either alone or in combination with anti-CD3 mAb, showed little effect on the PI turnover of whole cell extracts. Tat, however, selectively stimulated a nuclear-specific PI-PLC with a peak of activity after 30 min from the addition in culture to Jurkat cells. Interestingly, this time corresponded to that required for the uptake and nuclear localization of recombinant Tat protein, as demonstrated by electron microscope immunocytochemistry experiments with anti-Tat mAb. Moreover, exogenous Tat reached the nucleus of Jurkat cells in a bioactive form, as shown in a HIV-1 long terminal repeat-chloramphenicol acetyl transferase transactivation assay. The specific increase of a nuclear PI-PLC activity was further demonstrated by the ability of Tat to stimulate PI turnover also when added directly to isolated nuclei. As a whole, these data demonstrate that Tat selectively stimulates a nuclear polyphosphoinositide hydrolysis, which appears to be independent of the cellular PI turnover. The relevance of these findings for a better understanding of the biological functions of extracellular Tat is discussed.

Interferon beta mediated intracellular signalling traffic in human lymphocytes

The early molecular mechanisms activated by the treatment of human lymphocytes with human interferon beta have been studied. These identify an early increase with respect to control, in diacylglycerol (DG) levels as response to interferon treatment. Such a DG production was derived from the rapid and sequential activation of phosphoinositide specific phospholipase C and phospholipase D pathway. This suggests that a synergistic involvement of phosphatidylinositol-bis-phosphate (PIP2) hydrolysis and phosphatidylcholine (PC) breakdown provide early molecular events upon the interaction between interferon beta and its cell surface receptors. This finally leads to the slowing down of cell growth.

Rapid and transient phosphorylation of nuclear matrix proteins upon interferon-alpha treatment in Daudi lymphoma cells

Evidence for a rapid and transient hyperphosphorylation of a 45 kD protein in isolated nuclei from interferon-alpha-treated Daudi lymphoma cells is presented. Extraction of nuclear matrices from these nuclei has provided further evidence for the association of such a protein in the nuclear matrix structure. Because phosphorylation assays performed directly on nuclear matrices from interferon-treated cells have revealed rapid and transient increase of gamma 32P-ATP incorporation into this 45 kD band, an early involvement of the nuclear matrix in the response of the nucleus to the interferon antiproliferative message is suggested.

Phosphoinositide signalling enzymes in human T lymphocytes: modulation of phosphoinositidase C isoform gamma 1 upon interferon treatment

In human T lymphocytes immunoblotting analysis of phosphoinositidase C (PIC) isoforms has shown that gamma 1 is the most represented isoform both at the cytoplasmic and nuclear level, and that interferon beta produces, within 90 min of treatment, an increase of its expression. These results, also supported by immunoelectronmicroscopic investigation, strongly suggest the involvement of PIC gamma 1 in the cascade of molecular events generated by the interaction between interferon and its cell surface receptors.

Nuclear phosphoinositide signalling enzyme in human B lymphoid cells

The modulation of phosphoinositidase C (PIC) beta activity upon interferon treatment in Burkitt lymphoma cells (Daudi) and its localization and expression have been analyzed by Western blotting, immunocytochemical and immunoelectronmicroscopy analysis. Results have disclosed an early increase of phosphatidyl-inositol-bisphosphate (PIP2) hydrolysis at nuclear level upon interferon (IFN) treatment paralleled by the evidence of an increase of PIC beta 1 expression. PIC beta 1 expression has been detected in the nuclear compartment also in a clone of Daudi cells selected for the resistance to the antiproliferative action of interferon alpha but no modulation of the enzyme has been detected upon interferon treatment. Since no changes in terms of PIP2 hydrolysis have been found at nuclear level in this selected line, we suggest that the antiproliferative action of interferon on Burkitt lymphoma cells is mediated by a possible recruitment of nuclear PIC beta 1 expression.

Immunogold localization of glutathione transferase B1-1 in Proteus mirabilis

By using the immunolabelling technique, the cellular localization of glutathione transferase in Proteus mirabilis was investigated. Evidence was obtained indicating a significant higher content of glutathione transferase in the periplasmic than cytoplasmic space. This result further support the idea that bacterial glutathione transferase is involved in xenobiotic detoxication.

Interferon mediated phosphatidylinositol uptake and processing in nuclei isolated from Burkitt lymphoma cells

The kinetic analysis of exogenous [3H]phosphatidylinositol (PI) uptake and processing by nuclei isolated from Daudi lymphoma cells upon interferon alpha treatment has been performed. Results have disclosed that, with respect to controls, interferon induces an evident stimulation of label incorporation into nuclei. The incorporated [3H] PI has been found for phosphorylation and hydrolytic cleavage, indicating that the intranuclear transduction system activated by interferon at plasma membrane level, might involve the PI cycle as a possible route of intracellular signalling.

Evidence for an early and transient involvement of nuclear inositol lipids in subcellular signalling events related to DNA repair processes

The involvement of nuclear inositol lipids in the processes related to DNA repair upon ionizing radiation has been investigated in Murine Erythroleukaemia cells. Early changes in the in vitro phosphatidylinositol-bisphosphate phosphorylation in isolated nuclei were found to precede transiently the marked increase in DNA synthesis occurring after irradiation. Such an increase detected by anti-BrdU monoclonal antibodies has been found to be related mainly to DNA polymerase beta activity as revealed by the kinetic analysis of in vitro DNA synthesis. The results here presented allow us to speculate on a possible involvement of nuclear inositol lipids in the cascade of the early events leading to the regulation of DNA repair in the nucleus.

Relationship between nuclear ribonucleoprotein arrangement and cell proliferation in Burkitt lymphoma cells

The presence of body-like structures in nuclei from interferon alpha-treated Daudi cells has been shown on the ultrastructural level, by the use of different staining methods. The degree of their rearrangement in the nucleoplasm seems to be dependent on the time of interferon treatment. Since this morphological evidence has been found to be preceded by a slowing down of RNA transcriptional machinery early upon the interferon administration, it is speculated that interferon generated signals might lead to RNP granule accumulation in the nucleus and a consequent arrangement into defined structures.

Nucleolar morphological rearrangement related to transcriptional and replicative state in Burkitt lymphoma cells

The specific silver staining of nucleolar region organizers was applied to Daudi lymphoma control and interferon alpha-treated cells. Isolated nuclei from control and treated samples were used for the kinetic analysis of in vitro RNA and DNA synthesis. Results have shown that interferon treatment induces a reduction of the transcriptional and replicative activities within 90 min. Concomitant to these results is the modification of the organization of nucleoli. Intensity and distribution of silver grains are, in fact, different in treated cells nucleoli as compared to those of controls. Thus, the number and the arrangement of granules could be related to the functional state of the cells suggesting that the transient cascade of interferon-generated signals involves also modulation of nucleolar structure and function in accordance with the hypothesis of a relationship of cell proliferation rate to silver-stained nucleolar protein quantity.

Evidence for nuclear phosphoinositidase C activity in the antiproliferative signals produced by interferon in Burkitt lymphoma cells

The influence of interferon alpha on nuclear phosphoinositidase C (PIC) in Daudi cells has been analysed. Results showed an early increase of PIC activity detectable within 90 min of interferon treatment concomitant with an increase of diacylglcerol (DAG) levels. Since the interferon-induced DAG production is not modified by the addition of propranolol, a compound known to inhibit production of DAG from phosphatidylcholine hydrolysis, it is suggested that the interferon antiproliferative signal is transduced into the nucleus via the inositol lipid pathway. A parallel analysis performed on intact cells showed a rapid inhibition of PIC activity accompanied by an increase of DAG level thus suggesting that interferon-generated signals at plasma-membrane level use pathways different from that of inositol lipids. A selected clone of Daudi cells resistant to interferon action provided a control for specificity of results.