Soil pH effects on the interactions between dissolved zinc, non-nano- and nano-ZnO with soil bacterial communities

Zinc oxide nanoparticles (ZnO NPs) are used in an array of products and processes, ranging from personal care products to antifouling paints, textiles, food additives, antibacterial agents and environmental remediation processes. Soils are an environment likely to be exposed to manmade nanoparticles due to the practice of applying sewage sludge as a fertiliser or as an organic soil improver. However, understanding on the interactions between soil properties, nanoparticles and the organisms that live within soil is lacking, especially with regards to soil bacterial communities. We studied the effects of nanoparticulate, non-nanoparticulate and ionic zinc (in the form of zinc chloride) on the composition of bacterial communities in soil with a modified pH range (from pH 4.5 to pH 7.2). We observed strong pH dependent effects on the interaction between bacterial communities and all forms of zinc, with the largest changes in bacterial community composition occurring in soils with low and medium pH levels (pH 4.8 and 5.9). The high pH soil (pH 7.2) was less susceptible to the effects of zinc exposure. At the highest doses of zinc (2500 mg/kg dw soil) both nano and non-nano particulate zinc applications elicited a similar response in the soil bacterial community, and this differed significantly to the ionic zinc salt treatment. The results highlight the importance of considering soil pH in nanotoxicology studies, although further work is needed to determine the exact mechanisms controlling the toxicity and fate and interactions of nanoparticles with soil microbial communities

A Comparative Study of Proliferation and Hepatic Differentiationof Human Adipose-Derived Stem Cells

Human adipose-derived stem cells possess a lot of stem cell characteristics, so they may be considered a source of stem cell population. On the basis of that, we have investigated the hepatic potential of adipose-derived stem cells, obtained from liposuction, following two differentiation protocols. In the first procedure, medium was supplemented with epidermal growth factor (EGF), basic fibroblast growth factor, hepatocyte growth factor (HGF) and nicotinamide; the second involved the addition of factors such as dexametasone, EGF, insulin-transferrin-sodium selenite, HGF, dimethyl sulfoxide and oncostatin. In parallel, we carried out our study in the Hep G2 cell line, as human hepatic differentiated in vitro model. Immunocytochemical analysis and RT-PCR were performed using hepatic markers to evaluate cell differentiation. DNA content, MTT test and carboxyl fluorescein succinimidyl ester staining were carried out to evaluate cell proliferation. We reported the evidence of basal hepatic marker in undifferentiated adipose-derived stem cells, which confirmed their multipotency. A strong expression of albumin and α-fetoprotein was observed in hepatic-induced adipose-derived stem cells following both differentiation procedures. Morphological aspects of the two types of hepatic adipose-derived stem cells were alike. Proliferation index suggested that the first differentiation procedure promoted better growth than the second. These preliminary findings suggest adipose-derived stem cells may be induced into hepatic lineage, and the most significant difference between the two standard differentiation procedures concerns proliferation rate. This aspect is to be considered when adipose-derived stem cells are employed in research and clinical studies

In vitro polydeoxyribonucleotide effects on human pre-adipocytes

OBJECTIVES: Adipose tissue is the most abundant and accessible source of adult stem cells. Human processed lipoaspirate contains pre-adipocytes that possess one of the a characteristic pathways of multipotent adult stem cells and are able to differentiate in vitro into mesenchymal and also neurogenic lineages. Because stem cells have great potential for use in tissue repair and regeneration, it would be significant to be able to obtain large amounts of these cells in vitro. As demonstrated previously, purine nucleosides and nucleotides mixtures can act as mitogens for several cell types. The aim of this study was to evaluate the effects of polydeoxyribonucleotides (PDRN), at appropriate concentrations, on human pre-adipocytes grown in a controlled medium, also using different passages, so as to investigate the relationship between the effect of this compound and cellular senescence, which is the phenomenon when normal diploid cells lose the ability to divide further. MATERIALS AND METHODS: Human pre-adipocytes were obtained by liposuction. Cells from different culture passages (P6 and P16) were treated with PDRN at different experimental times. Cell number was evaluated for each sample by direct counting after trypan blue treatment. DNA assay and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test were also carried out in all cases. RESULTS AND CONCLUSIONS: PDRN seemed to promote proliferation of human pre-adipocytes at both passages, but cell population growth increased in pre-adipocyte at P16, after 9 days as compared to control. Our data suggest that PDRN could act as a pre-adipocyte growth stimulator

Neurogenic-committed human pre-adipocytes express CYP1A isoforms.

Stem cell models offer an opportunity both for therapeutic use and for the assessment of alternative in vitro models. Human lipoaspirate is a source of adult stem cells (pre-adipocytes), which are able to differentiate into various phenotypes, such as neurogenic lineage. Here, we analyse the suitability of these in vitro models in screening exogenous compounds, such as environmental pollutants, that may affect adipose cells and neurogenic development. To evaluate neurogenic differentiation, we analysed expression of cholinergic system and acetylcholinesterase immunoreactivity. Heterocyclic derivatives of polycyclic aromatic hydrocarbons (PAHs) are often significant components of environmental contaminants. As they contain inducers of cytochrome P450 1A1 (CYP1A1), we explored the activity of CYP1A1-related enzymes, i.e. 7-ethoxycoumarin- and 7-ethoxyresorufin-O-deethylase (ECOD and EROD) in both cell systems in basal conditions and after exposure to non-cytotoxic doses of β-naphthoflavone (BNF), a well-known PAH-type inducer. Both cell models showed basal and inducible levels of ECOD. Analysis of CYP1A1 protein expression and EROD-related enzyme activity confirmed the inducibility of the CYP1A1 isoform by BNF. These results demonstrate that mesenchymal adult stem cells can constitute innovative models. We therefore propose the use of pre-adipocytes and their neurogenic derivates to evaluate the cytotoxic/biological effects of unintended exposure to contaminants

Evaluation of candidate biomarkers for the assessment of PCBs contamination

Environmental pollutants exhibit a variety of adverse biological effects on human health. Polychlorinated Biphenyls (PCBs) can modulate differentiation, metabolism and function of the white adipose tissue (WAT) in humans through a wide range of mechanisms able to exert their effects in the whole organism. Moreover, interactions among different classes of compounds, frequently with opposing effects, complicate hazard evaluation and risk assessment creating a biomarker overview not easily linkable to the single class of compounds. The 'omics' revolution has spurred a variety of investigative techniques in a host of model systems, and has contributed to a rapid increase in the amount of data concerning on transcripts, proteins, metabolites and other molecules present in target tissues. In this preliminary study we investigated biomarker signatures of exposure to PCBs on multipotent pre-adipocytes, by using a double bioinformatics/genomic approach. A pre-identification of the genomic signatures for both metabolic and pathological pathways targeted by PCBs was approached by using integrated text mining tools (see abstract P11). Thereafter, pre-adipocytes were isolated from human donor WAT and, on the base of the cell vitality screening results (time and dose), were exposed for 72 hours to two dilutions of a mussel extract and to PCB 153 (10ng/ml). Subsequently, mRNAs were extracted and analysed for gene expression profile evaluation with Genechip Affymetrix HG-133 Plus 2.0. Data were analysed and compared with bioinformatics results (P11

Esposizione di pre-adipociti umani a PCB: risultati preliminary

I contaminanti lipofili come i policlorobifenili (PCB) possono essere accumulati nell\u2019ambiente concentrandosi ai livelli pi\uf9 elevati delle catene trofiche e raggiungendo valori potenzialmente tossici per gli organismi e rischiosi per la salute umana. Organismi filtratori come i molluschi bivalvi accumulano contaminanti organici associati a materiale particolato sospeso ma non biotrasformano gli xenobiotici e sono utilizzati comunemente come specie indicatrici della qualit\ue0 dell\u2019ambiente acquatico. Tra i PCB, il congenere 153 si \ue8 rivelato quasi sempre il pi\uf9 rappresentato ed abbondante (circa 20%) in tutti i campionamenti di mitili e costituisce con il PCB 138 il 40-60% dei congeneri totali e, insieme con il PCB 180 sono quasi sempre riscontrati nel tessuto adiposo umano. Il tessuto adiposo bianco (WAT), considerato a lungo esclusivamente come organo chiave dell\u2019omeostasi energetica, viene attualmente considerato il pi\uf9 esteso organo endocrino del corpo. Tra i numerosi inquinanti con attivit\ue0 di Interferenti Endocrini, i PCB sono stati misurati nel WAT. Questi composti lipofili sono in grado di modificare l\u2019attivit\ue0 dei ligandi endogeni dei fattori di trascrizione nucleare, fondamentali per il differenziamento, il metabolismo e la funzione degli adipociti. Durante lo studio, campioni di mitilo (Mytilus gallusprovincialis) sono stati raccolti per un anno, con scadenza ogni 10 giorni da novembre ad aprile e ogni 5 giorni da maggio a ottobre, estratti in acetone-esano (1:1), analizzati in gas-massa per la loro concentrazione in PCB ed utilizzati per l\u2019esposizione in vitro. I pre-adipociti utilizzati sono stati isolati dal tessuto adiposo proveniente da donatori umani sani, sottoposti ad interventi di liposuzione. Dopo aver esposto i pre-adipociti a tre concentrazioni scalari di PCB 153 e di estratto di mitilo per 24, 48 e 72 ore, \ue8 stata valutata la vitalit\ue0 cellulare con Crystal violetto per l\u2019identificazione della concentrazione e del tempo di incubazione ottimali per le successive esposizioni. L\u2019mRNA \ue8 stato estratto ed analizzato con Genechip Affymetrix HG-133 Plus 2.0. Nei pre-adipociti, esposti a PCB 153 (0,1ng/ml), \ue8 stata osservata una parziale alterazione dei geni, che si \ue8 esplicata con una pi\uf9 spiccata \u201cdown regulation\u201d