Impaired redox signaling and mitochondrial uncoupling contributes vascular inflammation and cardiac dysfunction in type 1 diabetes: Protective role of arjunolic acid

Vascular inflammation and cardiac dysfunction are the leading causes of mortality and morbidity among the diabetic patients. Type 1 diabetic mellitus (T1DM) is associated with increased cardiovascular complications at an early stage of the disease. The purpose of the present study was to explore whether arjunolic acid (AA) plays any protective role against cardiovascular complications in T1DM and if so, what molecular pathways it utilizes for the mechanism of its protective action. Streptozotocin (STZ) was used to induce T1DM in experimental rats. Alteration in plasma lipid profile and release of membrane bound enzymes like LDH (lactate dehydrogenase) and CK (creatine kinase) established the association of hyperlipidemia and cell membrane disintegration with hyperglycemia. Hyperglycemia altered the levels of oxidative stress related biomarkers, decreased the intracellular NAD and ATP concentrations. Hyperglycemia-induced enhanced levels of VEGF, ICAM-1, MCP-1 and IL-6 in the plasma of STZ treated animals indicate vascular inflammation in T1DM. Histological studies and FACS analysis revealed that hyperglycemia caused cell death mostly via the apoptotic pathway. Investigating molecular mechanism, we observed NF-κB and MAPKs (p38 and ERK1/2) activations, mitochondrial membrane depolarization, cytochrome C release, caspase 3 activation and PARP cleavage in apoptotic cell death in the diabetic cardiac tissue. Treatment with AA (20 mg/kg body weight) reduced hyperglycemia, membrane disintegration, oxidative stress, vascular inflammation and prevented the activation of oxidative stress induced signaling cascades leading to cell death. Results suggest that AA possesses the potential to be a beneficial therapeutic agent in diabetes and its associated cardiac complications.     

Micro-Raman spectroscopy of silver nanoparticle induced stress on optically-trapped stem cells

We report here results of a single-cell Raman spectroscopy study of stress effects induced by silver nanoparticles in human mesenchymal stem cells (hMSCs). A high-sensitivity, high-resolution Raman Tweezers set-up has been used to monitor nanoparticle-induced biochemical changes in optically-trapped single cells. Our micro-Raman spectroscopic study reveals that hMSCs treated with silver nanoparticles undergo oxidative stress at doping levels in excess of 2 μg/ml, with results of a statistical analysis of Raman spectra suggesting that the induced stress becomes more dominant at nanoparticle concentration levels above 3 μg/ml.     

Mycobacterium indicus pranii (Mw) re-establishes host protective immune response in Leishmania donovani infected macrophages: critical role of IL-12

Leishmania donovani, a protozoan parasite, causes a strong immunosuppression in a susceptible host and inflicts the fatal disease visceral leishmaniasis. Relatively high toxicity, low therapeutic index, and failure in reinstating host-protective anti-leishmanial immune responses have made anti-leishmanial drugs patient non-compliant and an immuno-modulatory treatment a necessity. Therefore, we have tested the anti-leishmanial efficacy of a combination of a novel immunomodulator, Mycobacterium indicus pranii (Mw), and an anti-leishmanial drug, Amphotericin B (AmpB). We observe that Mw alone or with a suboptimal dose of AmpB offers significant protection against L. donovani infection by activating the macrophages. Our experiments examining the anti-leishmanial activity of Mw alone or with AmpB also indicate a p38MAPK and ERK-1/2 regulated pro-inflammatory responses. The Mw-AmpB combination induced nitric oxide production, restored Th1 response, and significantly reduced parasite burden in wild type macrophages but not in IL-12-deficient macrophages indicating a pivotal role for IL-12 in the induction of host-protection by Mw and AmpB treatments. In addition, we observed that Mw alone or in combination with suboptimal dose of AmpB render protection against L. donovani infection in susceptible BALB/c mice. However, these treatments failed to render protection in IL-12-deficient mice in vivo which added further support that IL-12 played a central role in this chemo immunotherapeutic approach. Thus, we demonstrate a novel chemo-immunotherapeutic approach- Mw and AmpB crosstalk eliminating the parasite-induced immunosuppression and inducing collateral host-protective effects.     

Intercalation and induction of strand breaks by adriamycin and daunomycin: a study with human genomic DNA

The anticancer drugs Adriamycin (ADR) and Daunomycin (DNM) of the anthracycline family are effective in treating a variety of cancers. Although their interactions with other cellular targets may play a role in the selective cytotoxicity of these drugs, it is generally believed that intercalation with DNA is essential for their activity. However, a relationship has not yet been established between intercalation and cellular processes leading to cytotoxicity. The present study was designed to investigate the relationship, if any, between intercalation and DNA strand breaks. ADR and DNM were observed to be strong intercalators of human genomic DNA by absorption and fluorimetric methods that were further substantiated by rise in thermal melting temperature. DNM is the better intercalator of the two, which is also evident from circular dichroic spectral changes. DNA strand breaks, considered to be an index of genotoxicity, was assayed by single cell gel electrophoresis (SCGE; comet assay). ADR and DNM induced equivalent genotoxicity in normal human lymphocytes at a clinically used dose, which was observed to be independent of intercalation efficiency though positively correlated to yield of reactive oxygen species.     

Epicatechin ameliorates ionising radiation-induced oxidative stress in mouse [corrected] liver

The current study was intended to evaluate the hepatoprotective effect of Epicatechin (EC) against radiation-induced oxidative stress, in terms of inflammation and lipid peroxidation. Swiss albino mice were administered with EC (15 mg/kg body weight) for three consecutive days before exposing them to a single dose of 5-Gy (60)Co gamma (γ) irradiation. Mice were necropsied and livers were taken for immunohistochemistry, western blot analysis and biochemical tests for the detection of markers of hepatic oxidative stress. Nuclear translocation of nuclear factor kappa B (NF-κB) and lipid peroxidation were increased whereas the activities of superoxide dismutase (SOD) and catalase (CAT), reduced glutathione (GSH) content and ferric reducing antioxidant power (FRAP) were diminished upon radiation exposure compared to control. Translocation of NF-κB from cytoplasm to nucleus and lipid peroxidation were found to be inhibited whereas an increase in SOD, CAT, GSH and FRAP was observed in the mice treated with EC prior to irradiation. Thus, pre-treatment with EC offers protection against γ-radiation induced hepatic alterations.     

Increased Serum Hepcidin Levels in Subjects with the Metabolic Syndrome: A Population Study

The recent discovery of hepcidin, the key iron regulatory hormone, has changed our view of iron metabolism, which in turn is long known to be linked with insulin resistant states, including type 2 diabetes mellitus and the Metabolic Syndrome (MetS). Serum ferritin levels are often elevated in MetS (Dysmetabolic hyperferritinemia - DHF), and are sometimes associated with a true mild-to-moderate hepatic iron overload (dysmetabolic iron overload syndrome - DIOS). However, the pathophysiological link between iron and MetS remains unclear. This study was aimed to investigate, for the first time, the relationship between MetS and hepcidin at population level. We measured serum hepcidin levels by Mass Spectrometry in 1,391 subjects from the Val Borbera population, and evaluated their relationship with classical MetS features. Hepcidin levels increased significantly and linearly with increasing number of MetS features, paralleling the trend of serum ferritin. In multivariate models adjusted for relevant variables including age, C-Reactive Protein, and the HFE C282Y mutation, ferritin was the only significant independent predictor of hepcidin in males, while in females MetS was also independently associated with hepcidin. Overall, these data indicate that the fundamental iron regulatory feedback is preserved in MetS, i.e. that hepcidin tends to progressively increase in response to the increase of iron stores. Due to recently discovered pleiotropic effects of hepcidin, this may worsen insulin resistance and contribute to the cardiovascular complications of MetS.     

CXCL10 Is Critical for the Generation of Protective CD8 T Cell Response Induced by Antigen Pulsed CpG-ODN Activated Dendritic Cells

The visceral form of leishmaniasis is the most severe form of the disease and of particular concern due to the emerging problem of HIV/visceral leishmaniasis (VL) co-infection in the tropics. Till date miltefosine, amphotericin B and pentavalent antimony compounds remain the main treatment regimens for leishmaniasis. However, because of severe side effects, there is an urgent need for alternative improved therapies to combat this dreaded disease. In the present study, we have used the murine model of leishmaniasis to evaluate the potential role played by soluble leishmanial antigen (SLA) pulsed-CpG-ODN stimulated dendritic cells (SLA-CpG-DCs) in restricting the intracellular leishmanial growth. We found that mice vaccinated with a single dose of SLA-pulsed DC stimulated by CpG-ODN were protected against a subsequent leishmanial challenge and had a dramatic reduction in parasite burden along with the generation of parasite specific cytotoxic T lymphocytes. Moreover, we demonstrate that the induction of protective immunity conferred by SLA-CpG-DCs depends entirely on the CXC chemokine IFN-γ-inducible protein 10 (CXCL10; IP-10). CXCL10 is directly involved in the generation of a parasite specific CD8⁺ T cell-mediated immune response. We observed significant reduction of CD8⁺ T cells in mice depleted of CXCL10 suggesting a direct role of CXCL10 in the generation of CD8⁺ T cells in SLA-CpG-DCs vaccinated mice. CXCL10 also contributed towards the generation of perforin and granzyme B, two important cytolytic mediators of CD8⁺ T cells, following SLA-CpG-DCs vaccination. Together, these findings strongly demonstrate that CXCL10 is critical for rendering a protective cellular immunity during SLA-CpG-DC vaccination that confers protection against Leishmania donovani infection.     

Pathogenicity and Transmissibility of North American Triple Reassortant Swine Influenza A Viruses in Ferrets

North American triple reassortant swine (TRS) influenza A viruses have caused sporadic human infections since 2005, but human-to-human transmission has not been documented. These viruses have six gene segments (PB2, PB1, PA, HA, NP, and NS) closely related to those of the 2009 H1N1 pandemic viruses. Therefore, understanding of these viruses'' pathogenicity and transmissibility may help to identify determinants of virulence of the 2009 H1N1 pandemic viruses and to elucidate potential human health threats posed by the TRS viruses. Here we evaluated in a ferret model the pathogenicity and transmissibility of three groups of North American TRS viruses containing swine-like and/or human-like HA and NA gene segments. The study was designed only to detect informative and significant patterns in the transmissibility and pathogenicity of these three groups of viruses. We observed that irrespective of their HA and NA lineages, the TRS viruses were moderately pathogenic in ferrets and grew efficiently in both the upper and lower respiratory tracts. All North American TRS viruses studied were transmitted between ferrets via direct contact. However, their transmissibility by respiratory droplets was related to their HA and NA lineages: TRS viruses with human-like HA and NA were transmitted most efficiently, those with swine-like HA and NA were transmitted minimally or not transmitted, and those with swine-like HA and human-like NA (N2) showed intermediate transmissibility. We conclude that the lineages of HA and NA may play a crucial role in the respiratory droplet transmissibility of these viruses. These findings have important implications for pandemic planning and warrant confirmation.