Characterization of Terrestrial Dissolved Organic Matter Fractionated by pH and Polarity and Their Biological Effects on Plant Growth

Background: Humic substances are ubiquitous in the environment, complex mixtures, and known to be beneficial to plant growth. To better understand and identify components responsible for plant growth stimulation, a terrestrial aquatic DOM sample was fractionated according to pH and polarity, obtaining acid-soluble and acid-insoluble portions, as well as acid-soluble hydrophobic and hydrophilic fractions using C18. The various fractions were characterized then evaluated for their biological effects on plant growth using bioassays with corn at two carbon rates. Results: Approximately 43% and 57% of the carbon, and 31% and 69% of the iron, was found in the acid-insoluble and acid-soluble fractions, respectively. Upon separating the acid-soluble portion using C18 extraction, about 64% and 36% of the carbon (and 96% and 4% of the iron) was present in the hydrophilic and hydrophobic fractions, respectively. The acid-insoluble portion was more aromatic and less oxygenated than the acid-soluble fraction. The hydrophilic filtrate was oxygen-rich and contained mostly tannin-like molecules, while the hydrophobic retentate was more aromatic and lignin-like. During bioassay testing, it was found that more hydrophilic samples (those that are more oxygenated) yielded the highest response for shoot measurements. For root measurements, the lower DOC rate (0.01 mg/L C) gave better results than the higher DOC rate (0.1 mg/L C). Also, the hydrophobic, less oxygenated acid-insoluble sample performed better than the more hydrophilic acid-soluble portion. The polarity fractions at the lower carbon application showed that larger root systems occurred when there was more hydrophobic C18 retentate material present. The opposite was true for the root system at the higher carbon application, where larger roots existed when more hydrophilic C18 filtrate material was present. Conclusions: Compositional differences were found when comparing the acid-soluble versus acid-insoluble portions and the hydrophobic versus hydrophilic C18 fractions, and activity with respect to plant stimulation was discerned. While a carbon rate affect was observed during foliar application to corn plants (with the lower carbon rate generally yielding the best biological stimulation), the various observed trends indicate that plant response is due to not only the amount of carbon present but also the type of carbon

Establishing a Measure of Reproducibility of Ultrahigh-Resolution Mass Spectra for Complex Mixtures of Natural Organic Matter

This study describes a method for evaluating the reproducibility of replicate mass spectra acquired for complex natural organic matter (NOM) samples analyzed by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry, with regard to both peak detection and peak magnitude. Because studies of NOM characterization utilize not only the emergence and disappearance of peaks but also changes in relative peak magnitude, it is important to establish that the differences between samples are significantly larger than those between sample replicates. Here, a method is developed for correcting strict signal-to-noise thresholds, along with a new scheme for assessing the reproducibility of peak magnitudes. Furthermore, a systematic approach for discerning when the comparison of samples by the presence or absence of peaks is appropriate and when it is necessary to compare based on the relative magnitude of the peaks is presented. A variety of 10 different types of NOM samples are analyzed in duplicate or triplicate instrumental injections or experimental extractions. A framework for these procedures is provided, and acceptable reproducibility levels are recommended

Striatal infusion of cholesterol promotes dose-dependent behavioral benefits and exerts disease-modifying effects in Huntington's disease mice

A variety of pathophysiological mechanisms are implicated in Huntington's disease (HD). Among them, reduced cholesterol biosynthesis has been detected in the HD mouse brain from pre-symptomatic stages, leading to diminished cholesterol synthesis, particularly in the striatum. In addition, systemic injection of cholesterol-loaded brain-permeable nanoparticles ameliorates synaptic and cognitive function in a transgenic mouse model of HD. To identify an appropriate treatment regimen and gain mechanistic insights into the beneficial activity of exogenous cholesterol in the HD brain, we employed osmotic mini-pumps to infuse three escalating doses of cholesterol directly into the striatum of HD mice in a continuous and rate-controlled manner. All tested doses prevented cognitive decline, while amelioration of disease-related motor defects was dose-dependent. In parallel, we found morphological and functional recovery of synaptic transmission involving both excitatory and inhibitory synapses of striatal medium spiny neurons. The treatment also enhanced endogenous cholesterol biosynthesis and clearance of mutant Huntingtin aggregates. These results indicate that cholesterol infusion to the striatum can exert a dose-dependent, disease-modifying effect and may be therapeutically relevant in HD

Striatal infusion of cholesterol promotes dose-dependent behavioral benefits and exerts disease-modifying effects in Huntington's disease mice

A variety of pathophysiological mechanisms are implicated in Huntington's disease (HD). Among them, reduced cholesterol biosynthesis has been detected in the HD mouse brain from pre-symptomatic stages, leading to diminished cholesterol synthesis, particularly in the striatum. In addition, systemic injection of cholesterol-loaded brain-permeable nanoparticles ameliorates synaptic and cognitive function in a transgenic mouse model of HD. To identify an appropriate treatment regimen and gain mechanistic insights into the beneficial activity of exogenous cholesterol in the HD brain, we employed osmotic mini-pumps to infuse three escalating doses of cholesterol directly into the striatum of HD mice in a continuous and rate-controlled manner. All tested doses prevented cognitive decline, while amelioration of disease-related motor defects was dose-dependent. In parallel, we found morphological and functional recovery of synaptic transmission involving both excitatory and inhibitory synapses of striatal medium spiny neurons. The treatment also enhanced endogenous cholesterol biosynthesis and clearance of mutant Huntingtin aggregates. These results indicate that cholesterol infusion to the striatum can exert a dose-dependent, disease-modifying effect and may be therapeutically relevant in HD

New orphan disease therapies from the proteome of industrial plasma processing waste- a treatment for aceruloplasminemia

Abstract Plasma-derived therapeutic proteins are produced through an industrial fractionation process where proteins are purified from individual intermediates, some of which remain unused and are discarded. Relatively few plasma-derived proteins are exploited clinically, with most of available plasma being directed towards the manufacture of immunoglobulin and albumin. Although the plasma proteome provides opportunities to develop novel protein replacement therapies, particularly for rare diseases, the high cost of plasma together with small patient populations impact negatively on the development of plasma-derived orphan drugs. Enabling therapeutics development from unused plasma fractionation intermediates would therefore constitute a substantial innovation. To this objective, we characterized the proteome of unused plasma fractionation intermediates and prioritized proteins for their potential as new candidate therapies for human disease. We selected ceruloplasmin, a plasma ferroxidase, as a potential therapy for aceruloplasminemia, an adult-onset ultra-rare neurological disease caused by iron accumulation as a result of ceruloplasmin mutations. Intraperitoneally administered ceruloplasmin, purified from an unused plasma fractionation intermediate, was able to prevent neurological, hepatic and hematological phenotypes in ceruloplasmin-deficient mice. These data demonstrate the feasibility of transforming industrial waste plasma fraction into a raw material for manufacturing of new candidate proteins for replacement therapies, optimizing plasma use and reducing waste generation