LukS-PV,a component of Panton-Valentine leukocidin,exerts potent activity against acute myeloid leukemia in vitro and in vivo

LukS-PV, a component of Panton-Valentine leukocidin (PVL) secreted by Staphylococcus aureus, has been shown to inhibit proliferation and induce apoptosis in acute myeloid leukemia (AML) THP-1 cells. Here we investigated anti-leukemia activities of LukS-PV in HL-60 cells, using in vitro assays to assess the ability of LukS-PV to mediate cell viability, apoptosis and differentiation; and developing a Severe Combined Immunodeficiency (SCID) mouse model of disseminated AML with the HL-60 cells to examine in vivo anti-leukemia activity. LukS-PV inhibited viability and induced differentiation and apoptosis in the HL-60 AML cell line. In the SCID mice, LukS-PV potently inhibited tumor growth, decreased tumor cell infiltration into peripheral blood and tissues, and significantly increased mean survival time. No severe adverse effects, such as death, weight loss, or pathological changes in livers or spleens were observed in the toxicity test group. These results indicate that LukS-PV may be a novel and effective chemotherapeutic agent against AML.     

Chronic ethanol ingestion induces oxidative kidney injury through taurine-inhibitable inflammation

Chronic ethanol ingestion mildly damages liver through oxidative stress and lipid oxidation, which is ameliorated by dietary supplementation with the anti-inflammatory β-amino acid taurine. Kidney, like liver, expresses cytochrome P450 2E1 that catabolizes ethanol with free radical formation, and so also may be damaged by ethanol catabolism. Sudden loss of kidney function, and not liver disease itself, foreshadows mortality in patients with alcoholic hepatitis [J. Altamirano, Clin. Gastroenterol. Hepatol. 2012, 10:65]. We found that ethanol ingestion in the Lieber-deCarli rat model increased kidney lipid oxidation, 4-hydroxynonenal protein adduction, and oxidatively truncated phospholipids that attract and activate leukocytes. Chronic ethanol ingestion increased myeloperoxidase-expressing cells in kidney and induced an inflammatory cell infiltrate. Apoptotic terminal deoxynucleotidyl transferase nick-end labeling-positive cells and active caspase-3 increased in kidney after ethanol ingestion, with reduced filtration with increased circulating blood urea nitrogen (BUN) and creatinine. These events were accompanied by release of albumin, myeloperoxidase, and the acute kidney injury biomarkers kidney injury molecule-1 (KIM-1), neutrophil gelatinase-associated lipocalin, and cystatin c into urine. Taurine sequesters HOCl from myeloperoxidase of activated leukocytes, and taurine supplementation reduced renal lipid oxidation, reduced leukocyte infiltration, and reduced the increase in myeloperoxidase-positive cells during ethanol feeding. Taurine supplementation also normalized circulating BUN and creatinine levels and suppressed enhanced myeloperoxidase, albumin, KIM-1, and cystatin c in urine. Thus, chronic ethanol ingestion oxidatively damages kidney lipids and proteins, damages renal function, and induces acute kidney injury through an inflammatory cell infiltrate. The anti-inflammatory nutraceutical taurine effectively interrupts this ethanol-induced inflammatory cycle in kidney.     

Rutin decreases lipopolysaccharide-induced acute lung injury via inhibition of oxidative stress and the MAPK–NF-κB pathway

Acute lung injury (ALI) is a serious disease with unacceptably high mortality and morbidity rates. Up to now, no effective therapeutic strategy for ALI has been established. Rutin, quercetin-3-rhamnosyl glucoside, expresses a wide range of biological activities and pharmacological effects, such as anti-inflammatory, antihypertensive, anticarcinogenic, vasoprotective, and cardioprotective activities. Pretreatment with rutin inhibited not only histopathological changes in lung tissues but also infiltration of polymorphonuclear granulocytes into bronchoalveolar lavage fluid in lipopolysaccharide (LPS)-induced ALI. In addition, LPS-induced inflammatory responses, including increased secretion of proinflammatory cytokines and lipid peroxidation, were inhibited by rutin in a concentration-dependent manner. Furthermore, rutin suppressed phosphorylation of NF-κB and MAPK and degradation of IκB, an NF-κB inhibitor. Decreased activities of antioxidative enzymes such as superoxide dismutase, catalase, glutathione peroxidase, and heme oxygenase-1 caused by LPS were reversed by rutin. At the same time, we found that ALI amelioration by chelation of extracellular metal ions with rutin is more efficacious than with deferoxamine. These results indicate that the protective mechanism of rutin is through inhibition of MAPK–NF-κB activation and upregulation of antioxidative enzymes.     

Phytoplankton composition and spatial distribution of copper and zinc in the Fal Estuary (Cornwall,UK)

In the estuaries near Falmouth (Cornwall, UK) levels of dissolved copper and zinc are high, due to drainage of copper and tin mines. Phytoplankton species composition in the autumn of 1989 deviated in the metal-contaminated Restronguet Creek from that in other estuarine branches,viz. Fal, Tresillian and Percuil. In the riverine part of Restronguet Creek (Carnon River)Euglena mutabilis, known as an acidophilic (pH 3) metal-resistant flagellate, occurred at micromolar Cu and Zn, whereas in the clean riversChlamydomonas sp. andOocystis sp. occurred at nanomolar Cu and Zn. An ordination analysis revealed the following patterns in Cu, Zn and phytoplankton species composition in the poly- and euhaline waters. Seston-bound Zn and dissolved Zn were in equilibrium,Katodinium rotundatum is Zn-tolerant, andSkeletonema costatum occurred in water with high contents of Cu in seston. However, none of the variables in these patterns correlated at a significant level (p>0.05). The results show that algae-metal interactions are complicated, and that statistical correlations foundin situ need experimental verification.Communication no. 542 of the Delta Institute for Hydrobiological Research.     

Effects of amiprilose hydrochloride on the components of human skin equivalents

Summary Amiprilose hydrochloride has been shown to inhibit the proliferation of a number of hyperproliferative cell types including psoriatic skin cells. In the present study, the effects of amiprilose hydrochloride on human tissue equivalents were examined by incubating a) dermal equivalents, b) skin equivalents in the process of epidermalization, and c) mature skin equivalents, with varying concentrations of the drug. In all three models amiprilose hydrochloride concentrations of 0.1% (wt/vol) and lower were not toxic to fibroblasts and keratinocytes and did not interfere with the differentiation of the skin equivalent and the developing skin equivalent. When tested in dermal equivalents, concentrations of amiprilose hydrochloride between 0.1 and 0.5% resulted in changes in fibroblast morphology with development of large intracellular vacuoles, and concentrations greater than 5% were toxic. In mature skin equivalents, in addition to changes in fibroblast morphology, amiprilose hydrochloride in concentrations of 1 to 10% affected the epidermis. When 0.5% amiprilose hydrochloride was present in the developing skin equivalent during differentiation, the epidermal keratinocytes were also affected. Thus the morphology of basal keratinocytes was modified, the differentiation was incomplete, and the dermalepidermal attachment was compromised. These studies suggest the possibility of an extracellular mechanism of action of amiprilose hydrochloride and delineate acceptable dosage ranges for the potential drug. Supported in part by research grant AG01274 from the National Institutes of Health, Bethesda, MD, The R. A. Welch Foundation (B0502), The Texas Advanced Technology and Research Program (Wound Healing and Aging no. 2147), and Greenwich Pharmaceuticals, Inc. R. W. G. is the recipient of a MERIT award from the National Institute on Aging, Bethesda, MD.     

Mitochondrial toxicity and caspase activation in HIV pregnant women

To assess the impact of HIV‐infection and highly active anti‐retroviral treatment in mitochondria and apoptotic activation of caspases during pregnancy and their association with adverse perinatal outcome. Changes of mitochondrial parameters and apoptotic caspase activation in maternal peripheral blood mononuclear cells were compared at first trimester of pregnancy and delivery in 27 HIV‐infected and ‐treated pregnant women versus 24 uninfected pregnant controls. We correlated immunovirological, therapeutic and perinatal outcome with experimental findings: mitochondrial DNA (mtDNA) content, mitochondrial protein synthesis, mitochondrial function and apoptotic caspase activation. The HIV pregnancies showed increased adverse perinatal outcome (OR: 4.81 [1.14–20.16]; P < 0.05) and decreased mtDNA content (42.66 ± 5.94%, P < 0.01) compared to controls, even higher in naïve participants. This depletion caused a correlated decrease in mitochondrial protein synthesis (12.82 ± 5.73%, P < 0.01) and function (20.50 ± 10.14%, P < 0.001), not observed in controls. Along pregnancy, apoptotic caspase‐3 activation increased 63.64 ± 45.45% in controls (P < 0.001) and 100.00 ± 47.37% in HIV‐pregnancies (P < 0.001), in correlation with longer exposure to nucleoside analogues. HIV‐infected women showed increased obstetric problems and declined genetic and functional mitochondrial parameters during pregnancy, especially those firstly exposed to anti‐retrovirals. The apoptotic activation of caspases along pregnancy is emphasized in HIV pregnancies promoted by nucleoside analogues. However, we could not demonstrate direct mitochondrial or apoptotic implication in adverse obstetric outcome probably because of the reduced sample size.     

Heavy Metals and Trace Element Concentrations in Intertidal Soils of Four Estuaries of SW Iberian Peninsula

Soils from four estuaries of SW Iberian Peninsula, affected by anthropogenic influence (urban, industrial and agricultural activities), were analyzed for the occurrence of a variety of metals and trace elements including Al, As, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, S and Zn. The soils presented very high levels of salinity (high concentrations of Na, K and Mg), organic matter and, consequently, of C and N concentrations. In contrast, very low values of CaCO₃, Ca and P were found. In addition, it should be highlighted that in certain localities (Piedras 1 and 2 and Guadiana in Huelva, Spain, and Ria Formosa, Faro, Portugal) the concentrations of Pb, S and Zn were extremely high, reaching levels of pollution.     

Relationship between deterrence and toxicity of plant secondary compounds for the alfalfa weevil Hypera brunneipennis

A variety of plant secondary compounds, several of which are quite widespread in nature were tested for their deterrence to the specialist coleopteran Hypera brunneipennis (Boheman) in short-term behavioral assays. The compounds were nicotine, quinine, sparteine, hordenine, linamarin, amygdalin, sinigrin, morin, juglone, chlorogenic acid, digitonin, mimosine, diosgenin, rutin and ursolic acid. Nine of these were then tested for their post-ingestional effects over one to two weeks of adult life, using fecundity as a measure of the effects. In only one case was there any indication of a detrimental effect or any trend suggesting one. The evolutionary implications of these findings are discussed.     

Defining the limits: Protein aggregation and toxicity in vivo

Abstract

The proper folding of proteins to their functional forms is essential to cellular homeostasis. Perhaps not surprisingly, cells have evolved multiple pathways, some overlapping and others complementary, to resolve mis-folded proteins when they arise, ranging from refolding through the action of molecular chaperones to elimination through regulated proteolytic mechanisms. These protein quality control pathways are sufficient, under normal conditions, to maintain a functioning proteome, but in response to diverse environmental, genetic and/or stochastic events, protein mis-folding exceeds the corrective capacity of these pathways, leading to the accumulation of aggregates and ultimately toxicity. Particularly devastating examples of these effects include certain neurodegenerative diseases, such as Huntington’s Disease, which are associated with the expansion of polyglutamine tracks in proteins. In these cases, protein mis-folding and aggregation are clear contributors to pathogenesis, but uncovering the precise mechanistic links between the two events remains an area of active research. Studies in the yeast Saccharomyces cerevisiae and other model systems have uncovered previously unanticipated complexity in aggregation pathways, the contributions of protein quality control processes to them and the cellular perturbations that result from them. Together these studies suggest that aggregate interactions and localization, rather than their size, are the crucial considerations in understanding the molecular basis of toxicity.