Serum NMR-Based Metabolomics Profiling Identifies Lipoprotein Subfraction Variables and Amino Acid Reshuffling in Myeloma Development and Progression

Multiple myeloma (MM) is an incurable hematological cancer. It is preceded by monoclonal gammopathy of uncertain significance (MGUS)-an asymptomatic phase. It has been demonstrated that early detection increases the 5-year survival rate. However, blood-based biomarkers that enable early disease detection are lacking. Metabolomic and lipoprotein subfraction variable profiling is gaining traction to expand our understanding of disease states and, more specifically, for identifying diagnostic markers in patients with hematological cancers. This study aims to enhance our understanding of multiple myeloma (MM) and identify candidate metabolites, allowing for a more effective preventative treatment. Serum was collected from 25 healthy controls, 20 patients with MGUS, and 30 patients with MM. 1H-NMR (Nuclear Magnetic Resonance) spectroscopy was utilized to evaluate serum samples. The metabolite concentrations were examined using multivariate, univariate, and pathway analysis. Metabolic profiles of the MGUS patients revealed lower levels of alanine, lysine, leucine but higher levels of formic acid when compared to controls. However, metabolic profiling of MM patients, compared to controls, exhibited decreased levels of total Apolipoprotein-A1, HDL-4 Apolipoprotein-A1, HDL-4 Apolipoprotein-A2, HDL Free Cholesterol, HDL-3 Cholesterol and HDL-4 Cholesterol. Lastly, metabolic comparison between MGUS to MM patients primarily indicated alterations in lipoproteins levels: Total Cholesterol, HDL Cholesterol, HDL Free Cholesterol, Total Apolipoprotein-A1, HDL Apolipoprotein-A1, HDL-4 Apolipoprotein-A1 and HDL-4 Phospholipids. This study provides novel insights into the serum metabolic and lipoprotein subfraction changes in patients as they progress from a healthy state to MGUS to MM, which may allow for earlier clinical detection and treatment.

Stereoisomer-Dependent Membrane Association and Capacity for Insulin Delivery Facilitated by Penetratin

Cell-penetrating peptides (CPPs), such as penetratin, are often investigated as drug delivery vectors and incorporating d-amino acids, rather than the natural l-forms, to enhance proteolytic stability could improve their delivery efficiency. The present study aimed to compare membrane association, cellular uptake, and delivery capacity for all-l and all-d enantiomers of penetratin (PEN) by using different cell models and cargos. The enantiomers displayed widely different distribution patterns in the examined cell models, and in Caco-2 cells, quenchable membrane binding was evident for d-PEN in addition to vesicular intracellular localization for both enantiomers. The uptake of insulin in Caco-2 cells was equally mediated by the two enantiomers, and while l-PEN did not increase the transepithelial permeation of any of the investigated cargo peptides, d-PEN increased the transepithelial delivery of vancomycin five-fold and approximately four-fold for insulin at an extracellular apical pH of 6.5. Overall, while d-PEN was associated with the plasma membrane to a larger extent and was superior in mediating the transepithelial delivery of hydrophilic peptide cargoes compared to l-PEN across Caco-2 epithelium, no enhanced delivery of the hydrophobic cyclosporin was observed, and intracellular insulin uptake was induced to a similar degree by the two enantiomers.

Tumor repolarization by an advanced liposomal drug delivery system provides a potent new approach for chemo-immunotherapy

Immunosuppressive cells in the tumor microenvironment allow cancer cells to escape immune recognition and support cancer progression and dissemination. To improve therapeutic efficacy, we designed a liposomal oxaliplatin formulation (PCL8-U75) that elicits cytotoxic effects toward both cancer and immunosuppressive cells via protease-mediated, intratumoral liposome activation. The PCL8-U75 liposomes displayed superior therapeutic efficacy across all syngeneic cancer models in comparison to free-drug and liposomal controls. The PCL8-U75 depleted myeloid-derived suppressor cells and tumor-associated macrophages in the tumor microenvironment. The combination of improved cancer cell cytotoxicity and depletion of immunosuppressive populations of immune cells is attractive for combination with immune-activating therapy. Combining the PCL8-U75 liposomes with a TLR7 agonist induced immunological rejection of established tumors. This combination therapy increased intratumoral numbers of cancer antigen-specific cytotoxic T cells and Foxp3^- T helper cells. These results are encouraging toward advancing liposomal drug delivery systems with anticancer and immune-modulating properties into clinical cancer therapy.

Fungicides have complex effects on the wheat phyllosphere mycobiome

Effects of fungicide treatments on non-target fungi in the phyllosphere are not well known. We studied community composition and dynamics of target (Puccinia striiformis) and non-target fungi in wheat that was heavily infected with yellow rust. Mycobiotas in bulk leaf samples and individual leaves were studied by metabarcoding targeting the internal transcribed spacer-1 (ITS1) region of the ribosomal DNA. The amount of yellow rust in individual samples was quantified by qPCR (quantitative PCR). In addition, septoria tritici blotch (Zymoseptoria tritici), powdery mildew (Blumeria graminis), tan spot (Pyrenophora tritici-repentis), and yellow rust (P. striiformis) were visually evaluated. We showed how fungal communities were affected by three different broad-spectrum fungicides that had been applied at different timings and doses to control Puccinia striiformis. We showed that fungal content was relatively constant even after fungicide treatments. Principal component analysis demonstrated that communities from fungicide-treated plots could be separated from the communities in non-treated plots. We observed effects of fungicide treatments on fungal communities using different dose, timing and products. Some fungi, including the target organism P. striiformis were effectively controlled by most of the fungicide applications whereas some yeasts and also P. tritici-repentis increased after treatments. We demonstrated the feasibility of using metabarcoding as a supplement to visual assessments of fungicide effects on target as well as non-target fungi.

Characterization of the First "Candidatus Nitrotoga" Isolate Reveals Metabolic Versatility and Separate Evolution of Widespread Nitrite-Oxidizing Bacteria

Nitrification is a key process of the biogeochemical nitrogen cycle and of biological wastewater treatment. The second step, nitrite oxidation to nitrate, is catalyzed by phylogenetically diverse, chemolithoautotrophic nitrite-oxidizing bacteria (NOB). Uncultured NOB from the genus "Candidatus Nitrotoga" are widespread in natural and engineered ecosystems. Knowledge about their biology is sparse, because no genomic information and no pure "Ca Nitrotoga" culture was available. Here we obtained the first "Ca Nitrotoga" isolate from activated sludge. This organism, "Candidatus Nitrotoga fabula," prefers higher temperatures (>20°C; optimum, 24 to 28°C) than previous "Ca Nitrotoga" enrichments, which were described as cold-adapted NOB. "Ca Nitrotoga fabula" also showed an unusually high tolerance to nitrite (activity at 30 mM NO2-) and nitrate (up to 25 mM NO3-). Nitrite oxidation followed Michaelis-Menten kinetics, with an apparent Km (Km(app)) of ~89 µM nitrite and a Vmax of ~28 µmol of nitrite per mg of protein per h. Key metabolic pathways of "Ca Nitrotoga fabula" were reconstructed from the closed genome. "Ca Nitrotoga fabula" possesses a new type of periplasmic nitrite oxidoreductase belonging to a lineage of mostly uncharacterized proteins. This novel enzyme indicates (i) separate evolution of nitrite oxidation in "Ca Nitrotoga" and other NOB, (ii) the possible existence of phylogenetically diverse, unrecognized NOB, and (iii) together with new metagenomic data, the potential existence of nitrite-oxidizing archaea. For carbon fixation, "Ca Nitrotoga fabula" uses the Calvin-Benson-Bassham cycle. It also carries genes encoding complete pathways for hydrogen and sulfite oxidation, suggesting that alternative energy metabolisms enable "Ca Nitrotoga fabula" to survive nitrite depletion and colonize new niches.IMPORTANCE Nitrite-oxidizing bacteria (NOB) are major players in the biogeochemical nitrogen cycle and critical for wastewater treatment. However, most NOB remain uncultured, and their biology is poorly understood. Here, we obtained the first isolate from the environmentally widespread NOB genus "Candidatus Nitrotoga" and performed a detailed physiological and genomic characterization of this organism ("Candidatus Nitrotoga fabula"). Differences between key phenotypic properties of "Ca Nitrotoga fabula" and those of previously enriched "Ca Nitrotoga" members reveal an unexpectedly broad range of physiological adaptations in this genus. Moreover, genes encoding components of energy metabolisms outside nitrification suggest that "Ca Nitrotoga" are ecologically more flexible than previously anticipated. The identification of a novel nitrite-oxidizing enzyme in "Ca Nitrotoga fabula" expands our picture of the evolutionary history of nitrification and might lead to discoveries of novel nitrite oxidizers. Altogether, this study provides urgently needed insights into the biology of understudied but environmentally and biotechnologically important microorganisms.