Liraglutide, a human glucagon-like peptide-1 analogue, stimulates AKT-dependent survival signalling and inhibits pancreatic ß-cell apoptosis.

Liraglutide, a human long-lasting GLP-1 analogue, is currently regarded as a powerful treatment option for type 2 diabetes. Apart from glucoregulatory and insulinotropic actions, liraglutide increases ß-cell mass through stimulation of ß-cell proliferation and islet neogenesis, as well as inhibition of ß-cell apoptosis. However, the underline molecular mechanisms have not been fully characterized. In this study, we investigated the mechanism by which liraglutide preserves islet ß-cells in an animal model of overt diabetes, the obese db/db mice, and protects a mouse pancreatic ß-cell line (ßTC-6 cells) against apoptosis. Treatment of 12-week-old diabetic mice with liraglutide for 2 weeks had no appreciable effects on blood non-fasting glucose concentration, islet insulin content and body weight. However, morphological and biochemical examination of diabetic mouse pancreatic islets demonstrated that liraglutide restores islet size, reduces islet ß-cell apoptosis and improves nephrin expression, a protein involved in ß-cell survival signalling. Our results indicated that liraglutide protects ßTC-6 cells from serum withdrawal-induced apoptosis through inhibition of caspase-3 activation. The molecular mechanism of the anti-apoptotic action of liraglutide in ßTC-6-cells comprises stimulation of PI3-kinase-dependent AKT phosphorylation leading to the phosphorylation, hence inactivation of the pro-apoptotic protein BAD and inhibition of FoxO1 transcription factor. In conclusion, we provided evidence that the GLP-1 analogue liraglutide exerts important beneficial effects on pancreatic islet architecture and ß-cell survival by protecting cells against apoptosis. These findings extend our understanding of the actions of liraglutide and further support the use of GLP-1R agonists in the treatment of patients with type 2 diabetes.

Negative Association of Cognitive Performance With Blood Serum Neurotoxicity and Its Modulation by Human Herpes Virus 5 (HHV5) Seropositivity in Healthy Women.

Identification of early influences on cognitive decline is of paramount importance in order to stem the impacts of decrements in cognitive functioning and to potentially intervene. Thus, here we focused on 132 healthy adult women (age range 26-98 years) to (a) determine whether factors circulating in serum may exert neurotoxic effects in vitro, (b) evaluate associations between serum neurotoxicity and cognitive performance, and (c) assess the influence of human herpes virus (HHV) seroprevalence and other factors on apoptosis and cognitive performance. The results documented that the addition of serum from healthy adult women to neural cell cultures resulted in apoptosis, indicating the presence of circulating neurotoxic factors in the serum. Furthermore, apoptosis increased with age, and was associated with decreased cognitive performance. Stepwise regression evaluating the influence of 6 HHVs on apoptosis and cognitive function revealed that only HHV5 (cytomegalovirus; CMV) seropositivity was significantly associated with apoptosis and cognitive decline, controlling for age. These findings document neurotoxic effects of serum from healthy women across the adult lifespan and suggest a unique detrimental influence associated with CMV seropositivity.

Vaccines for Influenza.

Two reviews by Harding and Heaton [...].

Nanomedicine: Photo-activated nanostructured titanium dioxide, as a promising anticancer agent.

The multivariate condition of cancer disease has been approached in various ways, by the scientific community. Recent studies focus on individualized treatments, minimizing the undesirable consequences of the conventional methods, but the development of an alternative effective therapeutic scheme remains to be held. Nanomedicine could provide a solution, filling this gap, exploiting the unique properties of innovative nanostructured materials. Nanostructured titanium dioxide (TiO2) has a variety of applications of daily routine and of advanced technology. Due to its biocompatibility, it has also a great number of biomedical applications. It is now clear that photo-excited TiO2 nanoparticles, induce generation of pairs of electrons and holes which react with water and oxygen to yield reactive oxygen species (ROS) that have been proven to damage cancer cells, triggering controlled cellular processes. The aim of this review is to provide insights into the field of nanomedicine and particularly into the wide context of TiO2-NP-mediated anticancer effect, shedding light on the achievements of nanotechnology and proposing this nanostructured material as a promising anticancer photosensitizer.

Biological Effect of Silver-modified Nanostructured Titanium Dioxide in Cancer.

BACKGROUND/AIM: Nanomedicine is a promising scientific field that exploits the unique properties of innovative nanomaterials, providing alternative solutions in diagnostics, prevention and therapeutics. Titanium dioxide nanoparticles (TiO2 NPs) have a great spectrum of photocatalytic antibacterial and anticancer applications. The chemical modification of TiO2 optimizes its bioactive performance. The aim of this study was the development of silver modified NPs (Ag/TiO2 NPs) with anticancer potential. MATERIALS AND METHODS: Ag/TiO2 NPs were prepared through the sol-gel method, were fully characterized and were tested on cultured breast cancer epithelial cells (MCF-7 and MDA-MB-231). The MTT colorimetric assay was used to estimate cellular viability. Western blot analysis of protein expression along with a DNA-laddering assay were employed for apoptosis detection. RESULTS AND CONCLUSION: We show that photo-activated Ag/TiO2 NPs exhibited significant cytotoxicity on the highly malignant MDA-MB-231 cancer cells, inducing apoptosis, while MCF-7 cells that are characterized by low invasive properties were unaffected under the same conditions.

Anthrax Protective Antigen 63 (PA63): Toxic Effects in Neural Cultures and Role in Gulf War Illness (GWI).

Protective antigen (PA) 63 (PA63) is a protein derived from the PA83 component contained in the anthrax vaccine. The anthrax vaccine ("Biothrax") was administered together with other vaccines to Gulf War veterans, about 35% of whom later developed a multisymptom disease (Gulf War Illness [GWI]), with prominent neurological/cognitive/mood symptoms, among others. The disease has been traditionally attributed to exposures to toxic chemicals during the war but other factors could be involved, including vaccines received. Of these, the anthrax vaccine is the most toxic. Here, we assessed directly the PA63 toxin's harmful effects on cultured neuroblastoma 2A (N2A) cells with respect to cell spreading, process formation, apoptosis, and integrity of cell membrane, cytoskeleton, and mitochondria. We found that, when added in N2A cultures, PA63 toxin led to decreased cell spreading and cell aggregation, leading to apoptosis. The mechanisms of PA63-induced cell damage included compromised cell membrane permeability indicated by enhanced access of propidium iodide in cells. In addition, signaling pathways leading to organization of N2A cytoskeleton were negatively affected, as both actin and microtubular networks were compromised. Finally, the mitochondrial membrane potential was impaired in specific assays. Altogether, these alterations led to apoptosis as a collective toxic effect of PA63 which was substantially reduced by the concomitant addition of specific antibodies against PA63.

Vaccine-Induced Adverse Effects in Cultured Neuroblastoma 2A (N2A) Cells Duplicate Toxicity of Serum from Patients with Gulf War Illness (GWI) and Are Prevented in the Presence of Specific Anti-Vaccine Antibodies.

Gulf War illness (GWI) is a chronic disease of unknown etiology affecting over 200,000 veterans with symptoms including neurocognitive problems. We previously demonstrated GWI serum toxicity on neural cell cultures manifested by compromised neural network function, decreased cell spreading, and enhanced cell apoptosis. These patients lacked six human leukocyte antigen (HLA) class II alleles, resulting in an inability to form antibodies. Therefore, we hypothesized that GWI patients have vaccine-derived, persistent pathogens, which contribute to the development of the disease. Here, we examined whether individual vaccines were toxic in cultured N2A cells. Moreover, we used antibodies against each of the 20 vaccines administered to Gulf War (GW) veterans, to examine the effects of these antibodies on cell spreading and apoptosis in N2A cells. Antibodies against cholera toxin, hepatitis B, hemagglutinin H1N1, H3N2, and B from influenza A and B strains, measles, and Salmonella Typhi polysaccharide Vi had a remarkable protective effect on both cell spreading and apoptosis, whereas none of the other antibodies administered to GW veterans had an effect. The in vitro observed adverse effects of GWI serum may be due in part to vaccine-derived pathogens, antibodies against which had a protective effect in N2A cell cultures.

Adverse effects of Gulf War Illness (GWI) serum on neural cultures and their prevention by healthy serum.

Gulf War Illness (GWI) is a chronic debilitating disease of unknown etiology that affects the brain and has afflicted many veterans of the 1990-91 Gulf War (GW). Here we tested the hypothesis that brain damage may be caused by circulating harmful substances to which GW veterans were exposed but which could not be eliminated due to lack of specific immunity. We assessed the effects of serum from GWI patients on function and morphology of brain cultures in vitro, including cultures of embryonic mouse brain and neuroblastoma N2A line. Blood serum from GWI and healthy GW veterans was added, alone and in combination, to the culture and its effects on the function and morphology of the culture assessed. Neural network function was assessed using electrophysiological recordings from multielectrode arrays in mouse brain cultures, whereas morphological assessments (neural growth and cell apoptosis) were done in neuroblastoma cultures. In contrast to healthy serum, the addition of GWI serum disrupted neural network communication and caused reduced cell growth and increased apoptosis. All of these detrimental effects were prevented or ameliorated by the concomitant addition of serum from healthy GW veterans. These findings indicate that GWI serum contains neuropathogenic factors that can be neutralized by healthy serum. We hypothesize that these factors are persistent antigens circulating in GWI blood that can be neutralized, possibly by specific antibodies present in the healthy serum, as proposed earlier1.

Human Immunoglobulin G (IgG) Neutralizes Adverse Effects of Gulf War Illness (GWI) Serum in Neural Cultures: Paving the Way to Immunotherapy for GWI.

Gulf War Illness (GWI) is a chronic debilitating disease of unknown etiology that affects the brain and has afflicted many veterans of the 1990-91 Gulf War (GW). We showed recently1 that blood serum from patients suffering from GWI exerts detrimental effects on neural cultures, including reduced growth, increased apoptosis, and disruption of neural network function. Remarkably, these adverse effects were prevented by the concomitant addition to the culture of serum from healthy Gulf War (GW) era veterans. We interpreted those findings1 in the context of our hypothesis that GWI is, at least partly, due to circulating pathogenic persistent antigens2, probably coming from vaccines administered to GW veterans who lacked crucial Human Leukocyte Antigen (HLA) class 2 alleles3 and, therefore, could not make antibodies against those antigens; by contrast, healthy GW veterans who received the same vaccines and possessed HLA protection3 made antibodies that neutralized the various antigens. Thus, we hypothesized that the beneficial effect of the healthy serum on preventing the adverse GWI serum effects was due to the presence of antibodies against the persistent antigens. Here we tested this hypothesis by assessing the effect of pooled human immunoglobulin G (IgG) on ameliorating the GWI adverse effects on neural growth and apoptosis in neuroblastoma N2A cultures. We tested this effect in 14 GWI patients and found that IgG exerted a potent ameliorating effect by inhibiting the reduction in growth and increased apoptosis of GWI serum. These results lend support to our persistent antigen hypothesis1,2 and suggest an immunotherapy approach for treating GWI. This approach is further strengthened by our finding that the severity of GWI neurocognitive/mood (NCM) symptoms was positively correlated with the degree of apoptosis caused by GWI serum on the neural culture, thus validating the relevance of the apoptotic effect to NCM symptomatology. Finally, we used this relation to predict NCM scores based on the reduced apoptosis effected by IgG addition and found a predicted reduction in NCM symptom severity by ~60%. Altogether, these findings point to the possible beneficial use of IgG in treating GWI.

Nephrin, a transmembrane protein, is involved in pancreatic beta-cell survival signaling.

Nephrin, a cell surface signaling receptor, regulates podocyte function in health and disease. We study the role of nephrin in ß-cell survival signaling. We report that in mouse islet ß-cells and the mouse pancreatic beta-cell line (ßTC-6 cells) nephrin is associated and partly co-localized with PI3-kinase. Incubation of cells with functional anti-nephrin antibodies induced nephrin clustering at the plasma membrane, nephrin phosphorylation and recruitment of PI3-kinase to nephrin thus resulting in increased PI3K-dependent Akt phosphorylation and augmented phosphorylation/inhibition of pro-apoptotic Bad and FoxO. Nephrin silencing abolished Akt activation and increased susceptibility of cells to apoptosis. High glucose impaired nephrin signaling, increased nephrin internalization and up-regulated PKCα expression. Interestingly, a marked decrease in nephrin expression and phosphorylated Akt was observed in pancreatic islets of db/db lepr-/- diabetic mice. Our findings revealed that nephrin is involved in ß-cell survival and suggest that glucose-induced changes in nephrin signaling may contribute to gradual pancreatic ß-cell loss in type 2 diabetes.

Effect of nanostructured TiO2 crystal phase on photoinduced apoptosis of breast cancer epithelial cells.

PURPOSE: The use of nanoparticles has seen exponential growth in the area of health care, due to the unique physicochemical properties of nanomaterials that make them desirable for medical applications. The aim of this study was to examine the effects of crystal phase-nanostructured titanium dioxide particles on bioactivity/cytotoxicity in breast cancer epithelial cells. MATERIALS AND METHODS: Cultured Michigan Cancer Foundation (MCF)-7 and human breast adenocarcinoma (MDA-MB-468) breast cancer epithelial cells were exposed to ultraviolet A light (wavelength 350 nm) for 20 minutes in the presence of aqueous dispersions of two different nanostructured titanium dioxide (TiO2) crystal phases: anatase and an anatase-rutile mixture. Detailed characterization of each titanium dispersion was performed by dynamic light scattering. A 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) colorimetric assay was employed to estimate the percentage of viable cells after each treatment. Western blot analysis of protein expression and characterization, as well as a deoxyribonucleic acid (DNA)-laddering assay, were used to detect cell apoptosis. RESULTS: Our results documented that 100% anatase TiO2 nanoparticles (110-130 nm) exhibited significantly higher cytotoxicity in the highly malignant MDA-MB-468 cancer cells than anatase- rutile mixtures (75%/25%) with the same size. On the contrary, MCF-7 cells (characterized by low invasive properties) were not considerably affected. Exposure of MDA-MB-468 cells to pure anatase nanoparticles or anatase-rutile mixtures for 48 hours resulted in increased proapoptotic Bax expression, caspase-mediated poly(adenosine diphosphate ribose) polymerase (PARP) cleavage, DNA fragmentation, and programmed cell death/apoptosis. CONCLUSION: The obtained results indicated that pure anatase TiO2 nanoparticles exhibit superior cytotoxic effects compared to anatase-rutile mixtures of the same size. The molecular mechanism of TiO2 nanoparticle cytotoxicity involved increased Bax expression and caspase-mediated PARP inactivation, thus resulting in DNA fragmentation and cell apoptosis.