44 research outputs found

    Effects of the Infusion of 4% or 20% Human Serum Albumin on the Skeletal Muscle Microcirculation in Endotoxemic Rats

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    Sepsis-induced microcirculatory alterations contribute to tissue hypoxia and organ dysfunction. In addition to its plasma volume expanding activity, human serum albumin (HSA) has anti-oxidant and anti-inflammatory properties and may have a protective role in the microcirculation during sepsis. The concentration of HSA infused may influence these effects. We compared the microcirculatory effects of the infusion of 4% and 20% HSA in an experimental model of sepsis

    Changes in Zn homeostasis during long term culture of primary endothelial cells and effects of Zn on endothelial cell senescence

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    Endothelial cell senescence and Zn nutritional status influence cardiovascular disease. The influence of Zn appears dichotomous, hence it is imperative to understand the relationship with cellular senescence to improve knowledge about the molecular and cellular basis of the disease. Here we aimed to determine: 1) the impact of chronic exposure to a moderately high dose of Zn on senescence of endothelial cells; 2) the changes in Zn homeostasis during the lifespan of primary cultured endothelial cells; and 3) the susceptibility of proliferating and senescent endothelial cells to cell death after short term exposure to increasing doses of Zn and of the Zn chelator TPEN. Chronic exposure to Zn accelerated senescence and untreated cells at later passages, where doubling time had increased, displayed relocation of labile Zn and altered expression of genes involved in the response to Zn toxicity, including SLC30A1, SLC39A6, SLC30A5, SLC30A10 and metallothioneins, indicating that senescent cells have altered zinc homeostasis. Most Zn-dependent genes that were expressed differently between early and late passages were correlated with changes in the expression of anti-apoptotic genes. Short-term treatment with a high dose of Zn leads to cell death, but only in the population of cells at both earlier and later passages that had already entered senescence. In contrast, Zn depletion led to death of cells at earlier but not later passages, which suggests that there are sub-populations of senescent cells that are resistant to Zn depletion. This resistant senescent cell population may accumulate under conditions of Zn deficiency and contribute to vascular pathology

    Antimetastatic and Antitumor Activities of Orally Administered NAX014 Compound in a Murine Model of HER2-Positive Breast Cancer

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    The natural isoquinoline alkaloid Berberine (BBR) has been shown to possess several therapeutic effects, including anticancer activity. Different BBR derivatives have been designed and synthesized in order to obtain new compounds with enhanced anticancer efficacy. We previously showed that intraperitoneal (IP) administration of the BBR-derived NAX014 compound was able to counteract HER-2 overexpressing mammary tumors onset and progression in transgenic mice. However, the IP administration was found to induce organ toxicity at doses higher than 2.5 mg/Kg. In this study, we evaluated the effect of intragastric (IG) administration of 20 mg/kg of NAX014 on both safety and anticancer efficacy in HER-2/neu transgenic mice. Furthermore, cancer cell dissemination and migration, tumor cell senescence and immunological changes were examined. Our results demonstrated that IG NAX014 administration delayed the onset of mammary tumors with no negative effects on health and survival. NAX014 reduced HER-2 overexpressing BC cells migration in vitro and the frequency of lung metastasis in HER-2/neu transgenic mice. A statistically significant increase of senescence-associated p16 expression was observed in tumors from NAX014-treated mice, and the induction of cell senescence was observed in HER-2 overexpressing BC cells after in vitro treatment with NAX014. Although NAX014 did not modulate the presence of tumor-infiltrating lymphocytes, the level of circulating TNF-α and VEGF was found to be reduced in NAX014-treated mice. The overall results address the NAX014 compound as potential tool for therapeutic strategies against HER-2 overexpressing breast cancer

    Antiangiogenic and antitumor activities of berberine derivative NAX014 compound in a transgenic murine model of HER2/neu-positive mammary carcinoma

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    Berberine is a natural isoquinoline alkaloid with proven antiangiogenic and anticancer activities. We recently demonstrated that berberine and its synthetic derivative 13-(4-chlorophenylethyl)berberine iodide, NAX014, exert antiproliferative activity against HER2-overexpressing breast cancer cells, inducing apoptosis, modulating the expression of cell-cycle checkpoint molecules involved in cell senescence, and reducing both HER2 expression and phosphorylation on tumor cells. In this study we examined the anticancer properties of berberine and NAX014 in a transgenic mouse model which spontaneously develops HER2-positive mammary tumors. Repeated intraperitoneal injections of a safety dose (2.5 mg/kg) of NAX014 delayed the development of tumors, reducing both the number and size of tumor masses. In vivo sidestream dark field videomicroscopy revealed a significant lower vessel density in mammary tumors from NAX014-treated mice in comparison with the control group. Immunohystochemical evaluation using CD34 antibody confirmed the reduced vessel density in NAX014 group. Statistically significant increase of senescence associated β-galactosidase and p16 expression, and reduced expression of heparanase were observed in tumors from NAX014-treated mice than in tumors from control animals. Finally, NAX014 treatment decreased the level of perforine and granzyme mRNA in mammary tumors. Berberine did not show any statistically significant modulation in comparison to control mice.The results of the present study indicate that NAX014 is more effective than berberine in exerting anticancer activity delaying the development of mammary tumors in mice transgenic for the HER-2/neu oncogene. The antitumor efficacy of NAX014 is mainly related to its effect on tumor vascular network and on induction of tumor cell senescence

    Inducers of Senescence, Toxic Compounds, and Senolytics: The Multiple Faces of Nrf2-Activating Phytochemicals in Cancer Adjuvant Therapy

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    The reactivation of senescence in cancer and the subsequent clearance of senescent cells are suggested as therapeutic intervention in the eradication of cancer. Several natural compounds that activate Nrf2 (nuclear factor erythroid-derived 2-related factor 2) pathway, which is involved in complex cytoprotective responses, have been paradoxically shown to induce cell death or senescence in cancer. Promoting the cytoprotective Nrf2 pathway may be desirable for chemoprevention, but it might be detrimental in later stages and advanced cancers. However, senolytic activity shown by some Nrf2-activating compounds could be used to target senescent cancer cells (particularly in aged immune-depressed organisms) that escape immunosurveillance. We herein describe in vitro and in vivo effects of fifteen Nrf2-interacting natural compounds (tocotrienols, curcumin, epigallocatechin gallate, quercetin, genistein, resveratrol, silybin, phenethyl isothiocyanate, sulforaphane, triptolide, allicin, berberine, piperlongumine, fisetin, and phloretin) on cellular senescence and discuss their use in adjuvant cancer therapy. In light of available literature, it can be concluded that the meaning and the potential of adjuvant therapy with natural compounds in humans remain unclear, also taking into account the existence of few clinical trials mostly characterized by uncertain results. Further studies are needed to investigate the therapeutic potential of those compounds that display senolytic activity
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