Accumulation and effects of sulfadimethoxine in Salix fragilis L. plants: a preliminary study to phytoremediation purposes

The application of manure to fertilize arable lands is one of the major means through which veterinary sulfonamides (SAs) enter the environment. Little is known about the capacity of woody plants to phytoremediate this class of antibiotics. To this purpose we performed preliminary studies to evaluate Salix fragilis L. response to sulfadimethoxine (SDM) by investigating both its ability to absorb and tolerate doses of SDM found in fresh faeces of treated calves. Forty cuttings were exposed to either 0, 0.5, 1, or 2 mM of SDM for one month. Decreases in photosynthetic electron transport rate and net CO2 assimilation after 25 days for the higher SDM concentrations were noticed. Moreover, alterations in root morphology of treated plants were observed and further investigated through electron microscopy. However, collected data revealed high root accumulation potential. These preliminary results are promising as they demonstrate that Salix fragilis L. can both absorb and tolerate high concentrations of SAs.     

Production of a monoclonal antibody by ascites, hollow fiber system, and transgenic plants for vaccine production using CB.Hep-1 mAb as a study case

Monoclonal antibody (mAb) production methods (ascites, in vitro technologies, transgenic animals, and dicot or monocot transgenic plants; moss, algae) have been improved since they were first developed in 1975. In this study, we illustrate a summary of a study case in which mice, a hollow fiber system, and tobacco transgenic plants were assessed for the production of mAb for vaccine manufacturing and vaccine production.     

miRandola: Extracellular Circulating MicroRNAs Database

MicroRNAs are small noncoding RNAs that play an important role in the regulation of various biological processes through their interaction with cellular messenger RNAs. They are frequently dysregulated in cancer and have shown great potential as tissue-based markers for cancer classification and prognostication. microRNAs are also present in extracellular human body fluids such as serum, plasma, saliva, and urine. Most of circulating microRNAs are present in human plasma and serum cofractionate with the Argonaute2 (Ago2) protein. However, circulating microRNAs have been also found in membrane-bound vesicles such as exosomes. Since microRNAs circulate in the bloodstream in a highly stable, extracellular form, they may be used as blood-based biomarkers for cancer and other diseases. A knowledge base of extracellular circulating miRNAs is a fundamental tool for biomedical research. In this work, we present miRandola, a comprehensive manually curated classification of extracellular circulating miRNAs. miRandola is connected to miRò, the miRNA knowledge base, allowing users to infer the potential biological functions of circulating miRNAs and their connections with phenotypes. The miRandola database contains 2132 entries, with 581 unique mature miRNAs and 21 types of samples. miRNAs are classified into four categories, based on their extracellular form: miRNA-Ago2 (173 entries), miRNA-exosome (856 entries), miRNA-HDL (20 entries) and miRNA-circulating (1083 entries). miRandola is available online at: http://atlas.dmi.unict.it/mirandola/index.html.     

Long-chain acylcarnitines regulate the HERG channel

Background and purpose

In some pathological conditions carnitine concentration is high while in othersitis low.In bothcases,cardiac arrhythmiascan occur and lead to sudden cardiac death. It has been proposed that in ischaemia, acylcarnitine (acyl-CAR), but not carnitine, is involved in arrhythmiasthrough modulation of ionic currents. We studied the effects of acyl-CARs on hERG, K_IR2.1 and K_v7.1/minKchannels (channels responsible for I_KR, I_K1 and I_KS respectively).

Experimental approach

HEK293 cells stably expressing hERG, K_IR2.1 or Kv7.1/minK were studied using the patch clamp technique. Free carnitine (CAR) and acyl-CAR derivatives from medium- (C8 and C10) and long-chain (C16 and C18∶1) fatty acids were applied intra- and extracellularly at different concentrations. Forstudies onhERG, C16 and C18∶1 free fatty acid were also used.

Key results

Extracellular long-chain (LCAC), but not medium-chain, acyl-CAR,induced an increase of I_hERG amplitude associated with a dose-dependent speeding of deactivation kinetics. They had no effect on K_IR2.1 or Kv7.1/minK currents.Computer simulations of these effects wereconsistent with changes in action potential profile.

Conclusions and applications

Extracellular LCAC tonically regulates I_hERG amplitude and kineticsunder physiological conditions. This modulation maycontribute tothe changes in action potential duration thatprecede cardiac arrhythmias in ischaemia, diabetes and primary systemic carnitine deficiency.     

Therapeutic attenuation of mitochondrial dysfunction and oxidative stress in neurotoxin models of Parkinson's disease

Parkinson's disease (PD) is a progressive neurodegenerative disorder for which there is no current therapy preventing cumulative neuronal loss. There is substantial evidence that mitochondrial dysfunction, oxidative stress, and associated caspase activity underlie the neurodegeneration observed. One potential drug therapy is the potent free radical scavenger and antioxidant cystamine, which has demonstrated significant clinical potential in models of neurodegenerative disorders and human neurological disease. This study examined the oral efficacy of cystamine in the MPTP and 6-hydroxydopamine neurotoxin models of PD. The neuroprotective effects of cystamine treatment significantly ameliorated nigral neuronal loss, preserved striatal dopaminergic projections, and improved striatal dopamine and metabolite levels, as compared to MPTP alone. Cystamine normalized striatal 8-hydroxy-2'-deoxyguanosine levels and ATP concentrations, consistent with reduced oxidative stress and improved mitochondrial function. Cystamine also protected against MPTP-induced mitochondrial loss, as identified by mitochondrial heat shock protein 70 and superoxide dismutase 2, with concomitant reductions in cytochrome c and caspase-3 activities. The neuroprotective value of cystamine was confirmed in the 6-hydroxydopamine model. Together these findings show cystamine's therapeutic benefit to reduce neuronal loss through attenuation of oxidative stress and mitochondrial dysfunction, providing the rationale for human clinical trials in PD patients.     

Use of the Gram stain in microbiology

The Gram stain differentiates bacteria into two fundamental varieties of cells. Bacteria that retain the initial crystal violet stain (purple) are said to be 'Gram-positive,' whereas those that are decolorized and stain red with carbol fuchsin (or safranin) are said to be 'Gram-negative.' This staining response is based on the chemical and structural makeup of the cell walls of both varieties of bacteria. Gram-positives have a thick, relatively impermeable wall that resists decolorization and is composed of peptidoglycan and secondary polymers. Gram-negatives have a thin peptidoglycan layer plus an overlying lipid-protein bilayer known as the outer membrane, which can be disrupted by decolorization. Some bacteria have walls of intermediate structure and, although they are officially classified as Gram-positives because of their linage, they stain in a variable manner. One prokaryote domain, the Archaea, have such variability of wall structure that the Gram stain is not a useful differentiating tool.     

The stimulatory effect of testosterone propionate and 17β-estradiol on 5′-methylthioadenosine phosphorylase activity in rat target tissues

The effect of castration and subsequent administration of 17β-estradiol and testosterone propionate on 5′-methylthioadenosine phosphorylase activity in rat target tissues was studied. Castration 34 days earlier resulted in a 95 reduction in ventral prostate 5′-methylthioadenosine phosphorylase activity and 16 days earlier in a 67% reduction in uterine 5′-methylthiodenosine phosphorylase activity. Four days of testosterone propionate administration stimulated ventral prostate 5′-methylhioadenosine phosphorylase activity 32% above castrate levels, which represented more than 50% of the intact control levels. 17β-Estradiol on the other hand stimulated uterine 5′-methylthioadenosine phosphorylase activity of 35% above castrate controls within 24h and with 3 days of continuous hormone treatment to within 97% of the intact control levels. However, castration and subsequent 17β-estradiol administration did not affect 5′-methylthioadenosine phosphorylase activity in rat liver and lung. Both prostate and uterine 5′-methylthioadenosine phosphorylase were shown to metabolize 5′-methylthioadenosine to 5′-methylthioribose through a 5′-methythiribose 1-phosphate intermediate. The data suggest that 5′-methylthioadenosine is not allowed to accumulate in rat target tissues even under conditions which are known to stimulate polyamine synthesis.     

Neurolysin: From Initial Detection to Latest Advances

The mechanisms by which peptidergic signals are terminated have been the center of multiple studies leading to the discoveries of novel proteolytic activities. When studying the catabolic fate of neurotensin (NT) in brain and gastrointestinal tract, we detected a novel activity belonging to the metallopeptidases class and apparently distinct from previously known enzymes. Purification and cloning confirmed that this NT-degrading neutral metalloendopeptidase activity was indeed original. It was named endopeptidase 3.4.24.16 according to the IUBMB nomenclature and later, referred to as neurolysin. This review tells the history of neurolysin from its initial detection to its purification, cloning, design of specific inhibitors as well as in vitro and in vivo pharmacological studies aimed at delineating its role in the control of NT function. Finally, we discuss very recent advances suggesting a potential role of neurolysin in pathologies.     

Biotechnological potential of plant growth-promoting bacteria from the roots and rhizospheres of endemic plants in ironstone vegetation in southeastern Brazil

Microorganisms associated with plants have a great biotechnological potential, but investigations of these microorganisms associated with native plants in peculiar environments has been incipient. The objective of this study was to analyze the plant growth-promoting bacteria potential of cultivable bacteria associated with rare plants from the ferruginous rocky fields of the Brazilian Iron Quadrangle. The roots and rhizospheres of nine endemic plants species and samples of a root found in a lateritiric duricrust (canga) cave were collected, the culturable bacteria isolated and prospected for distinct biotechnological and ecological potentials. Out of the 148 isolates obtained, 8 (5.4%) showed potential to promote plant growth, whereas 4 (2.7%) isolates acted as biocontrol agents against Xanthomonas citri pathotype A (Xac306), reducing the cancrotic lesions by more than 60% when co-inoculated with this phytopathogen in Citrus sinensis plants. Moreover, other 4 (2.7%) isolates were classified as potential bioremediation agents, being able to withstand high concentrations of arsenite (5 mM As³⁺) and arsenate (800 mM As⁵⁺), by removing up to 35% and 15% of this metalloid in solution, respectively. These same four isolates had a positive influence on the growth of both the roots and the aerial parts when inoculated with tomato seeds in the soil contaminated with arsenic. This is the first time that an investigation highlights the potentialities of bacteria associated with rare plants of ferruginous rocky fields as a reservoir of microbiota of biotechnological and ecological interest, highlighting the importance of conservation of this area that is undergoing intense anthropic activity.

Graphical abstract

Open image in new window