Nitric oxide action on growth factor-elicited signals. Phosphoinositide hydrolysis and [Ca2+]i responses are negatively modulated via a cGMP-dependent protein kinase I pathway.

Abstract The role of nitric oxide (NO) in the phosphatidylinositol 4,5-bisphosphate (PIP2) hydrolysis and intracellular Ca2+ release responses induced by epidermal, platelet-derived, and fibroblast growth factors was investigated in three cell lines, a clone of NIH-3T3 fibroblasts overexpressing epidermal growth factor receptors and the tumoral epithelial cells A431 and KB. In all three cell types, pretreatment with NO donors decreased growth factor-induced PIP2 and Ca2+ responses, whereas pretreatment with NO synthase inhibitors increased them. The Ca2+-dependent PIP2 hydroysis induced by micromolar concentrations of the Ca2+ ionophore, ionomycin, was also modulated negatively and positively by NO donors and synthase inhibitors, respectively. In contrast, the Ca2+ content of the intracellular stores was unaffected by the various pretreatments employed. NO donors and synthase inhibitors induced an increase and decrease, respectively, of the intracellular cGMP formation in all three cell lines investigated. All of the effects of the NO donors were mimicked by 8-bromo-cGMP administration and abolished by pretreatment with the specific blocker of the cGMP-dependent protein kinase I, KT5823, which by itself mimicked the effects of the synthase inhibitors. Together with previous observations on G protein-coupled receptors, the present results demonstrate that PIP2 hydrolysis and Ca2+ release occur under the feedback control of NO, independently of the phospholipase C (β, γ, or δ type) involved and of the mechanism of activation. Such a control, which appears to be effected by the cGMP-dependent protein kinase I acting at the level of the phospholipases C themselves, might ultimately contribute to the inhibitory role of NO on growth previously observed with various cell types

Cognitive analytics management of the customer lifetime value: an artificial neural network approach

Purpose: The purpose of this study is to show that the use of CAM (cognitive analytics management) methodology is a valid tool to describe new technology implementations for businesses. Design/methodology/approach: Starting from a dataset of recipes, we were able to describe consumers through a variant of the RFM (recency, frequency and monetary value) model. It has been possible to categorize the customers into clusters and to measure their profitability thanks to the customer lifetime value (CLV). Findings: After comparing two machine learning algorithms, we found out that self-organizing map better classifies the customer base of the retailer. The algorithm was able to extract three clusters that were described as personas using the values of the customer lifetime value and the scores of the variant of the RFM model. Research limitations/implications: The results of this methodology are strictly applicable to the retailer which provided the data. Practical implications: Even though, this methodology can produce useful information for designing promotional strategies and improving the relationship between company and customers. Social implications: Customer segmentation is an essential part of the marketing process. Improving further segmentation methods allow even small and medium companies to effectively target customers to better deliver to society the value they offer. Originality/value: This paper shows the application of CAM methodology to guide the implementation and the adoption of a new customer segmentation algorithm based on the CLV

ERK1 and ERK2 are involved in recruitment and maturation of human mesenchymal stem cells induced to adipogenic differentiation

Adipocytes' biology and the mechanisms that control adipogenesis have gained importance because of the need to develop therapeutic strategies to control obesity and the related pathologies. Human mesenchymal stem cells (hMSCs), undifferentiated stem cells present in the bone marrow that are physiological precursors of adipocytes, were induced to adipogenic differentiation. The molecular mechanisms on the basis of the adipogenesis were evaluated, focusing on the MAPKinases ERK1 and ERK2, which are involved in many biological and cellular processes. ERK1 and ERK2 phosphorylation was reduced with different timing and intensity for the two isoforms in treated hMSCs in comparison with control cells until day 10 and then at 14-28 days, it reached the level of untreated cultures. The total amount of ERK1 was also decreased up to day 10 and then was induced to the level of untreated cultures, whereas the expression of ERK2 was not changed following adipogenic induction. Treatment with the specific ERK1/2 inhibitor U0126 during the whole differentiation period hampered hMSCs' adipogenic differentiation, as lipid droplets appeared in very few cells and were reduced in number and size. When U0126 was administered only during the initial phase of differentiation, the number of hMSCs recruited to adipogenesis was reduced while, when it was administered later, hMSCs did not acquire a mature adipocytic phenotype. ERK1 and ERK2 are important for hMSC adipogenic differentiation since any alteration to the correct timing of their phosphorylation affects either the recruitment into the differentiation program and the extent of their maturation

Embryonic rat dorsal root ganglia organotypic culture: a morphometric model to test neurotoxicology

Neurotoxicity is a common dose-limiting side-effect of several drugs (Cavaletti et al., 2008). So far a validated test method to screen drugs neurotoxicity does not exist, therefore in this interdepartment study we have analyzed the effectiveness of a morphometric neurotoxicty assessment model. Drug neurotoxicity evaluation is based on embryonic rat dorsal root ganglia (DRG) organotypic culture. DRG primary sensory neurons are the principal target of drugs neurotoxic action. In fact, primary sensory neurons lie outside the blood-nerve barrier and are supplied by capillaries with fenestrated walls. Moreover, the axons of these cells are among the longest of the entire nervous system and, therefore, are more susceptible to any agent that interferes with the energy metabolism or the structural basis of axonal transport. In particular, in this interdepartment study, the interference of the under study neurotoxic compound with NGF-induced neurite elongation is analysed. The effectiveness and reproducibility of this model, even if commonly used to test drugs, has not yet been demonstrated. In order to assess the validity of this in vitro model, antineoplastic drugs known to be in clinical use and in animal models neurotoxic (paclitaxel and oxaliplatin) or not dangerous (cyclophosphamide and 5-Fluorouracil) have been tested. DRGs explanted from E15 rat embryos have been treated for 24h with drugs concentrations comparable to those achievable in vivo. The length of the longest neurite of each DRG has been measured by ImageJ program. Experiments have been performed by three different blinded researchers in two different laboratories. Mean and standard deviation of each experiment were obtained, subsequently the mean value and standard deviation of the three independent experiments for each researcher were calculated. Data obtained by the three researchers in two different laboratories resulted statistically comparable and no significant differences were detected (One Way Anova analysis of variance and Tukey post test; p<0.05). This interdepartment in vitro study, therefore, indicates that a purely morphometric model represents a reliable tool to study drug neurotoxicity, permitting to make prediction of neurotoxic effects on humans because the concentrations tested are the same to which DRG are exposed during clinical use

Evaluation of neural markers expression in human mesenchymal stem cells after mesengenic differentiation

Introduction. Mesenchymal Stem Cells (MSCs) are adult multipotent cells able to differentiate in mesengenic (osteogenic, adipogenic, condrogenic) and non mesengenic lineages (e.g. neural) under appropriate culture conditions. MSCs represent a very promising therapeutic approach in different settings particularly for tissue repair and regeneration. The knowledge of human MSCs (hMSCs) biological properties is very important to optimize their clinical application. In view of MSCs application in neurodegenerative diseases, the neuronal differentiation potential of hMSCs has been also explored. Our preliminary data demonstrated that the neuronal markers beta III tubulin and NeuN were spontaneously expressed by a high percentage of undifferentiated hMSCs independently from serum presence and number of culture passages. The expression of neural markers by MSCs in absence of any differentiative agents is considered as a demonstration of MSC neural predisposition. The aim of this work was to evaluate if these markers, known to be neuronal ones, continued to be expressed also in hMSCs differentiated towards mesengenic lineages. Methods. hMSCs were obtained after patient consensus, from iliac crest bone marrow. In according to the Mesenchymal and Tissue Stem Cell Committee of the International Society for Cellular Therapy, the isolated hMSCs were plastic-adherent, capable of extensive proliferation when maintained in standard culture conditions, lacked of hematopoietic markers expression and presented specific surface antigens. hMSCs were differentiated toward osteogenic, adipogenic and chondrogenic lineages using specific in vitro protocols. The expression of the neuronal markers beta III tubulin and NeuN were evaluated by immunofluorescence experiments at different time points depending on the differentiation protocol used. hMSCs cultured in absence of any differentiative agent represented controls. Results. In our experiments the most of hMSCs differentiated in osteogenic and adipogenic lineages expressed the neuronal markers beta III tubulin and NeuN. Unlike, chondrogenic differentiated hMSCs didn’t express these markers. Conclusions. The finding that hMSCs differentiated into adipogenic and osteogenic lineages express neuronal markers such as beta III tubulin  and NeuN raises doubts about the reliability of these markers as indicators of neuronal differentiation and suggests that their expression could be an intrinsic property of a wide range of cellular types. Further studies are necessary to understand the specific biological role of of beta III tubulin and NeuN in hMSCs differentiated towards mesengenic lineages

Effects of valproic Acid, berberin and resveratrol on human mesenchymal stem cells adipogenic differentiation

Nowadays obesity and its related diseases represent a major health problem with an increasing worldwide prevalence. Hyperplasia and hypertrophy of adipocytes lead to an excessive fat accumulation that is not efficiently prevented by current pharmacological treatments. So the research on anti-obesity drugs with good efficacy and tolerability able both to prevent and to reduce fat accumulation is of pivotal interest. In the present study we evaluated in vitro the effects of Valproic Acid, Berberin and Resveratrol on adipogenesis. Our experimental model was represented by human Mesenchymal Stem Cells (hMSCs), physiological precursors of adipocytes that can differentiate into adipocytes also in vitro. Preliminary cytotoxicity assays were performed in order to choose non-toxic doses of the three drugs. hMSCs were induced to adipogenic differentiation and treated with Valproic Acid, Berberin and Resveratrol at the selected doses. Controls were represented by hMSCs treated for adipogenesis in absence of the drugs. At different time points intracellular lipid droplets accumulation, a typical feature of adipogenesis, was assessed by Oil Red O staining. Valproic Acid, Berberin and Resveratrol inhibited hMSCs adipogenic differentiation in a dose dependent manner as demonstrated by the reduction of the lipid droplets accumulation. To understand the molecular mechanisms of the drugs-induced adipogenesis inhibition, we focused our attention on the effects of the drugs treatment on cell cycle progression, known to be altered by many antiadipogenic drugs, and on the MAP Kinases ERK1 and ERK2, involved in the adipogenesis control. We evaluated the expression of cyclins and CDKs by immunoblotting and flow-cytometry analyses, demonstrating that Valproic Acid, Berberin and Resveratrol interfere on cell cycle progression. The expression and the phosphorylation status of the two kinases ERK1 and ERK2 were assessed by immunoblotting demonstrating an increase of ERK1 phosphorylation (i.e. activation) in hMSCs treated with Berberin and a reduction in hMSCs treated with Valproic Acid and Resveratrol compared to control cells. No changes in phosphorylation and expression of ERK2 were observed. Our study demonstrate that Valproic Acid, Berberin and Resveratrol exert an anti-adipogenic effect in our experimental model. The mechanisms of action of these drugs involve the alteration of cell cycle progression and, at least in part, ERK1/2 modulation. However other molecular pathways are likely implicated and other studies are required to identify them

The fundamental role of morphology in experimental neurotoxicology: the example of chemotherapy-induced peripheral neurotoxicity

The peripheral nervous system is a frequent target of toxic agents. The accurate identification of the sites of neurotoxic action through the morphological characterization of reliable in vivo models or in vitro systems can give fundamental clues when investigating the pathogenesis and interpreting the clinical features of drug-induced neuropathy. The morphological approach has been used to investigate almost all the anticancer drugs able to induce chemotherapy-induced peripheral neurotoxicity, i.e. platinum drugs, antitubulins and proteasome inhibitors. No models have ever been described for thalidomide. This review demonstrates that any pathogenetic study on chemotherapy-induced peripheral neurotoxicity must be based on solid morphological observations obtained in reliable animal and in vitro models. This is particularly true in this setting, since the availability of tissues of human origin is extremely limited. In fact, peripheral (generally sural) nerve biopsies are never required for diagnostic purposes in chemotherapy-treated cancer patients, and their use for a purely scientific aim, although potentially very informative, is not ethical. Moreover, several neurotoxic drugs target the dorsal root ganglia neurons, and it is very difficult to obtain high-quality specimens even from early autopsies. It is, therefore, our opinion that an extensive morphological assessment of the in vitro and in vivo effect of any potentially neurotoxic antineoplastic drugs, as well as of neuroprotectant agents, should be taken into consideration right from the earliest stages of their development

Antitumoral effects of Hibiscus Sabdariffa on human breast cancer cells

Hibiscus Sabdariffa (HS) is a plant commonly used in folk medicine (1). In recent years HS has gained great interest due to its important antioxidant, anti-inflammatory and antitumoral properties. In our work, we evaluated the in vitro anticancer effects of HS extract against two different human breast cancer cell lines: estrogen receptor (ER) positive MCF-7 cells and ER negative MDA-MB-231 cells. We tested both total extract (HSE) and one fraction obtained by ethyl acetate extraction (HSEC). MTT assay and Trypan Blue vital count showed a dose and time dependent reduction of the viability in both cell lines treated with different concentrations of HSE or HSEC compared to untreated control cells. A significantly marked reduction was observed in MCF-7 cells treated with HSEC. On the basis of our results we used the concentrations of 7.5mg/ml and 3.5mg/ml respectively for HSE and HSEC. In order to evaluate ER involvement in HS effect, we analyzed the cellular localization of the receptor (ERα isotype) by immunofluorescence experiments. Untreated MDA-MB-231 cells showed a low expression of the receptor mostly localized at the cytoplasmic level and treatment with HSE or HSEC didn’t change this state. Untreated MCF-7 cells showed a greater expression of the receptor, with nuclear and cytoplasmic localization. Following HSE or HSEC treatment ERα localization became more cytoplasmic and this effect was more evident after HSEC induction. These data were also confirmed by ERα western blot analysis. Subsequently, we studied HSE and HSEC ability to alter migration and invasion capacity of ER positive MCF-7 cells. Using a scratch wound healing assay we did not observe any change in the migration of cells compared to untreated cells. On the contrary, in a Boyden chamber invasion assay, HSE, and especially HSEC, induced reduction of MCF-7 cell invasion. In conclusion, we have demonstrated that HS is able to reduce cell viability of ER positive MCF-7 and ER negative MDA-MB-231 cells. This effect is more evident in MCF-7 cells in which ER localization and reduced cell invasion were observed. These results are more evident after HSEC treatment. Further studies will be needed to better elucidate the involved mechanisms of action

Human oral squamous cell carcinoma proliferation and migration prevented by two flavonoids

Oral Cancer (OC) is one of the most frequent cancer in Head and Neck district and Oral Squamous Cell Carcinoma (OSCC) constitutes the large majority of the neoplasia arising in oral cavity. OSCC remains a hampering matters for clinics, since the overall disease free survival has not significantly increased during the last decades and invasion to surrounding tissue and to regional lymph nodes is often reported. Therefore new strategies to prevent and inhibit OSCC growth and invasion are highly desirable and new therapeutic approaches are currently tempted also with the use of natural compounds. Myricetin (MYR) and Naringenin (NAR), two naturally occurring flavonoids, widely diffused in plants, fruits and vegetable, have recently gained consideration thanks to their anti oxidant, anti inflammatory and anti tumoral properties. In this study their potential anticancer effect has been evaluated on an OSCC cell line, SCC-25 and on spontaneously immortalized non tumoral keratinocytes, HaCaT cells. MYR and NAR induce a significant cell growth inhibition in SCC-25 cells, in addition NAR selectively affected cancer cells, since it does not impair HaCaT cell growth. Furthermore an additive effect of MYR and NAR has been highlighted. The cell proliferation inhibition is not related to apoptosis induction, as demonstrated by evaluation of phosphatidyl serine membrane translocation and dapi staining. On the contrary MYR and NAR effect depends on the cell cycle progression impairment. Wound-healing and cell invasion assays, respectively performed by cell monolayer scratch and Boyden Chamber transwell test, demonstrate that the two flavonoids are able to reduce motility and invasiveness on both SCC-25 and HaCaT cells. In conclusion the results of the present study show the anticancer potential of NAR and MYR on OSCC, since both flavonoids prevent cancer cell proliferation through a cytostatic effect, by the impairment of cell cycle progression. Moreover both the flavonoids inhibit cell migration, thus highlighting their potential effect as anti metastatic agents

Antitumoral effects of Hibiscus sabdarifa on human oral squamous cell carcinoma and multiple myeloma cells

Epidemiological data consistently demonstrate a reduced cancer risk associated with a polyphenols rich diet. Hibiscus sabdarifa (HS), a polyphenols rich plant widely consumed worldwide as beverage and used in folk medicine, has recently gained interest thanks to its antioxidant, anti-inflammatory and chemopreventive properties. In the present study we investigated the antitumoral potential of HS extract in two different human tumor cell lines: Multiple Myeloma cells (RPMI 8226) and Oral Squamous Cell Carcinoma cells (SCC-25). MTT assays showed that HS extract induced a dose-dependent viability reduction in both the cells lines. For the subsequent experiments we used HS at the concentration of 5 mg/ml that was the most effective in inducing cell viability reduction after 48h of treatment. Viable cell count using trypan blue staining demonstrated that the HS extract induced decrease in cell growth of both the cell lines and this was due to a reversible cytostatic rather than a cytotoxic effect. Wound-healing and cell invasion assays, respectively performed by a scratch of cell monolayer and Boyden Chamber transwell test, demonstrated that HS extract was able to reduce motility and invasiveness in both RPMI 8226 and SCC-25 cells. The chemical inhibition of ERK1/ERK2 and PI3K, with U0126 and wortmannin respectively, reduces proliferation and migration of both SSC-25 and RPMI cells and HB extract treatment played an additive action with the inhibitors. In conclusion, our results suggest that HS extract have antitumoral properties, since it proved to inhibit tumoral cell growth and cell migration and invasiveness. It is interesting to note that HS extract is effective against two very different tumor cell lines. In fact, RPMI 8226 cells are of hematopoietic origin and grow in suspension, whereas SCC-25 cells derive from epithelium and are characterized by adherent cell growth. Therefore, although further studies are needed to clarify the molecular mechanisms involved in its action, we proposed HS as a potential chemopreventive agent