Chronic lead exposure disrupts neurometabolic activity in mouse brain: An ex vivo1H-[13C]-NMR study.

Lead poisoning has been identified as a problem in adults as well as in children. Chronic exposure to lead has been implicated in neurological disorders such as amyotrophic lateral sclerosis, Parkinson's disease, and Alzheimer's disease. In the present study, we evaluated the impact of chronic lead exposure on cerebral glutamatergic and GABAergic metabolic activity in mice. C57BL6 mice were provided lead acetate in drinking water for two months. The regional cerebral metabolic activity was measured using 1H-[13C]-NMR spectroscopy in conjunction with infusion of [1,6-13C2]glucose. The blood Pb2+ increased significantly in lead acetate treated mice. Concomitantly, there was a significant reduction in the forelimb strength. The level of myo-inositol was elevated in the cerebral cortex of mice chronically exposed to lead. The glutamatergic neurometabolic activity was found to be reduced following chronic lead exposure in the cerebral cortex, hippocampus, and striatum. In contrast, the GABAergic fluxes were impaired in the hippocampus and thalamus only. The metabolic fluxes in the cerebellum were unperturbed to Pb2+ toxicity. In conclusion, we report that chronic lead exposure in mice leads to an impairment in forelimb strength, and a perturbation in neurometabolism in brain regions involving cognition and movement.

A comparative study of antibody response, virus neutralization efficiency & metabolites in SARS-CoV-2-infected adults & children.

Background & objectives: COVID-19 has been a global pandemic since early 2020. It has diverse clinical manifestations, but consistent immunological and metabolic correlates of disease severity and protection are not clear. This study was undertaken to compare seropositivity rate, antibody levels against nucleocapsid and spike proteins, virus neutralization and metabolites between adult and child COVID-19 patients. Methods: Plasma samples from naïve control (n=14) and reverse transcription (RT)-PCR positive COVID-19 participants (n=132) were tested for reactivity with nucleocapsid and spike proteins by ELISA, neutralization of SARS-CoV-2 infectivity in Vero cells and metabolites by [1]H nuclear magnetic resonance (NMR) spectroscopy. Results: An ELISA platform was developed using nucleocapsid and spike proteins for COVID-19 serosurvey. The participants showed greater seropositivity for nucleocapsid (72%) than spike (55.3%), and males showed higher seropositivity than females for both the proteins. Antibody levels to both the proteins were higher in intensive care unit (ICU) than ward patients. Children showed lower seropositivity and antibody levels than adults. In contrast to ICU adults (81.3%), ICU children (33.3%) showed lower seropositivity for spike. Notably, the neutralization efficiency correlated with levels of anti-nucleocapsid antibodies. The levels of plasma metabolites were perturbed differentially in COVID-19 patients as compared with the naive controls. Interpretation & conclusions: Our results reflect the complexity of human immune response and metabolome to SARS-CoV-2 infection. While innate and cellular immune responses are likely to be a major determinant of disease severity and protection, antibodies to multiple viral proteins likely affect COVID-19 pathogenesis. In children, not adults, lower seropositivity rate for spike was associated with disease severity.

Gene delivery into human cancer cells by cationic lipid-mediated magnetofection.

In this study, a combination of magnetic nanoparticles (MNPs) together with cationic lipid N,N-di-n-hexadecyl-N,N-dihydroxyethylammonium chloride formulated with colipid cholesterol, upon magnetofection, enhanced DNA uptake into human glioblastoma-astrocytoma, epithelial-like cell line U-87 MG, hepatocellular carcinoma Hep G2, cervical cancer HeLa and breast cancer MDA-MB-231 cells. Having confirmed this, we monitored uptake of plasmid DNA mediated by ternary magnetoplexes by fluorescence microscopy, flow cytometry and reporter gene expression assays in the presence and absence of a magnetic field. Our observations clearly indicate enhanced transfection efficiency in vitro, upon magnetofection, in the presence of serum as seen from ß-Gal reporter gene expression. The observed activity in serum suggests the suitability of MNPs for in vivo applications. Further, we measured the transverse relaxation time (T2) and obtained T2-weighted MRI images of treated U-87 MG cells. T2 determined for MNP-VP-Me22 and MNP-VP-Et22 corresponds to 22.6±0.8 ms and 36.0±2.1 ms, respectively, as compared to 47±1.7 ms for control, suggesting their applicability in molecular imaging. Our results collectively highlight the potential of lipid-based approach to augment magnetic-field guided-gene delivery using MNPs and additionally towards developing intracellular molecular probes for magnetic resonance imaging.