No abstract

Interactions of silver phosphate nanoparticles (SPNPs) and selenium nanoparticles (SeNPs) with Staphylococcus aureus cultures have been studied at the cellular, molecular and protein level. Significant antibacterial effects of both SPNPs and SeNPs on S. aureus were observed. At a concentration of 300 μM, SPNPs caused 37.5% inhibition of bacterial growth and SeNPs totally inhibited bacterial growth. As these effects might have been performed due to the interactions of nanoparticles with DNA and proteins, the interaction of SPNPs or SeNPs with the amplified zntR gene was studied. The presence of nanoparticles decreased the melting temperatures of the nanoparticle complexes with the zntR gene by 23% for SeNPs and by 12% for SPNPs in comparison with the control value. The concentration of bacterial metallothionein was 87% lower in bacteria after application of SPNPs (6.3 μg mg(-1) protein) but was increased by 29% after addition of SeNPs (63 μg mg(-1) protein) compared with the S. aureus control (49 μg mg(-1) protein). Significant antimicrobial effects of the nanoparticles on bacterial growth and DNA integrity provide a promising approach to reducing the risk of bacterial infections that cannot be controlled by the usual antibiotic treatments.

Metallothioneins (MTs) are involved in protection against oxidative stress (OS) and toxic metals and they participate in zinc metabolism and its homeostasis. Disturbing of zinc homeostasis can lead to formation of reactive oxygen species, which can result in OS causing alterations in immunity, aging, and civilization diseases, but also in cancer development. It is not surprising that altered zinc metabolism and expression of MTs are of great interest in the case of studying of oncogenesis and cancer prognosis. The role of MTs and zinc in cancer development is tightly connected, and the structure and function of MTs are strongly dependent on Zn²⁺ redox state and its binding to proteins. Antiapoptic effects of MTs and their interactions with proteins nuclear factor kappa B, protein kinase C, esophageal cancer-related gene, and p53 as well as the role of MTs in their proliferation, immunomodulation, enzyme activation, and interaction with nitric oxide are reviewed. Utilization of MTs in cancer diagnosis and therapy is summarized and their importance for chemoresistance is also mentioned.

Metallothioneins (MTs) are a group of low molecular mass, cysteine-rich proteins with a variety of functions including involvement in metal homeostasis, free radical scavenging, protection against heavy metal damage, and metabolic regulation via Zn donation. The overexpression of MTs in proliferating cells is turning the attention to the study of MTs as novel promising marker of tumor diseases. Besides, levels of MTs in invertebrates and aquatic vertebrates well correlate with heavy metal pollution of an environment and, thus, serve as bio-environmental marker. It is not surprising that these proteins are of great interest not only for biochemists, molecular biologists clinical chemists, but also for environmental chemists and ecologists.Detection and quantification of MTs, which is needed in all above mentioned areas, is challenging due to the high cysteine content and relatively low molecular mass. This review is giving an overview of the analytical methods used for determination of MTs comprising a broad range of immunochemical, electrochemical as well as spectrometric methods, which have been optimized and even hyphenated with different separation methods to detect MTs. More attention is paid to the structural analysis of these proteins as well as the employment of analytical instruments for environmental, biochemical and clinical purposes.

Sparsely tested group of platinum nanoparticles (PtNPs) may have a comparable effect as complex platinum compounds. The aim of this study was to observe the effect of PtNPs in in vitro amplification of DNA fragment of phage λ, on the bacterial cultures (Staphylococcus aureus), human foreskin fibroblasts and erythrocytes. In vitro synthesized PtNPs were characterized by dynamic light scattering (PtNPs size range 4.8–11.7 nm), zeta potential measurements (-15 mV at pH 7.4), X-ray fluorescence, UV/vis spectrophotometry and atomic absorption spectrometry. The PtNPs inhibited the DNA replication and affected the secondary structure of DNA at higher concentrations, which was confirmed by polymerase chain reaction, DNA sequencing and DNA denaturation experiments. Further, cisplatin (CisPt), as traditional chemotherapy agent, was used in all parallel experiments. Moreover, the encapsulation of PtNPs in liposomes (LipoPtNPs) caused an approximately 2.4x higher of DNA damage in comparison with CisPt, LipoCisPt and PtNPs. The encapsulation of PtNPs in liposomes also increased their antibacterial, cytostatic and cytotoxic effect, which was determined by the method of growth curves on S. aureus and HFF cells. In addition, both the bare and encapsulated PtNPs caused lower oxidative stress (determined by GSH/GSSG ratio) in the human erythrocytes compared to the bare and encapsulated CisPt. CisPt was used in all parallel experiments as traditional chemotherapy agent.

Zinc(II) ions contribute to a number of biological processes e.g. DNA synthesis, gene expression, enzymatic catalysis, neurotransmission, and apoptosis. Zinc(II) dysregulation, deficiency and over-supply are connected with various diseases, particularly cancer. 98 % of human body zinc(II) is localized in the intracellular compartment, where zinc(II) is bound with low affinity to metallothionein (MT). Zinc transporters ZIP and ZnT maintain transmembrane transport from/to cells or organelles. Imbalance of their regulation is described in cancers, particularly prostate (down-regulated zinc transporters ZIP1, 2, 3 and ZnT-2) and breast, notably its high-risk variant (up-regulated ZIP6, 7, 10). As a result, intracellular and even blood plasma zinc(II) levels are altered. MT protects cells against oxidative stress, because it cooperates with reduced glutathione (GSH). Recent studies indicate elevated serum level of MT in a number of malignancies, among others in breast, and prostate. MT together with zinc(II) affect apoptosis and proliferation, thus together with its antioxidative effects it may affect cancer. To date, only little is known about the influence of zinc(II) and MT on cancer, while these compounds may play an important role in pathogenesis. This review concludes current data regarding the impact of zinc(II) on the pathogenesis of breast and prostate cancers with potential outlines of new, targeted therapy and prevention. Moreover, blood plasma zinc(II) and MT levels and dietary zinc(II) intake are discussed in relation to breast and prostate cancer risk.

This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. 1 Microarray analysis of metallothioneins in human diseases AbstractMetallothioneins (MTs), low molecular mass cysteine-rich proteins, which are able to bind up to 20 monovalent and up to 7 divalent heavy metal ions are widely studied due to their functions in detoxification of metals, scavenging free radicals and cells protection against the oxidative stress. It was found that the loss of the protective effects of MT leads to an escalation of pathogenic processes and carcinogenesis. 3The most extensive area is MTs expression for oncological applications, where the information about gene patterns is helpful for the identification biological function, resistance to drugs and creating the correct chemotherapy. In other medical applications the effect of oxidative stress to cell lines exposed to heavy metals and hydrogen peroxide is studied as well as influence of drugs and cytokines on MTs expression and MTs expression in the adiposetissue. The precise detection of low metallothionein concentrations and its isoforms is necessary to understand the connection between quantity and isoforms of MTs to size, localization and type of cancer. This information is necessary for well-timed therapy and increase the chance to survival. Microarray chips appear as good possibility for finding all information about expression of MTs genes and isoforms not only in cancer, but also in other diseases, especially diabetes, obesity, cardiovascular diseases, ageing, osteoporosis, psychiatric disorders and as the effects of toxic drugs and pollutants, which is discussed in this review. List of abbreviations:HCC -hepatocellular carcinoma, HFD -high fat diet, MMP -matrix metalloproteinase, MT -metallothionein, MTF -metal transcription factor, MRE -metal responsive element, ROS -reactive oxygen species.

Histamine is a heterocyclic amine formed by decarboxylation of the amino acid L-histidine. It is involved in the local regulation of physiological processes but also can occur exogenously in the food supply. Histamine is toxic at high intakes; therefore, determination of the histamine level in food is an important aspect of food safety. This article will review the current understanding of physiological functions of endogenous and ingested histamine with a particular focus placed on existing and emerging technologies for histamine quantification in food. Methods reported in this article are sequentially arranged and provide a brief overview of analytical methods reported, including those based on nanotechnologies.