Implication of MAPK, Lipocalin-2, and Fas in the protective action of liposomal resveratrol against isoproterenol-induced kidney injury.

Background and Objective: Isoproterenol (ISO) is a non-selective ß-adrenergic receptor agonist. It can be used to treat bradycardia and cardiogenic shock. Despite its usefulness, the overstimulation of ß-receptors by ISO can cause "cardiorenal syndrome," a term used to describe heart and kidney damage. Resveratrol (RES), a natural polyphenol, has marked anti-inflammatory and antioxidant activities. The present work was designed to study the protective efficacy of liposomal resveratrol (L-RES) against ISO-induced kidney injury. Materials and Methods: The kidney injury was induced in rats by administering ISO (50 mg/kg, s.c.) twice a week for 2 weeks. RES and L-RES were administered at a dose (20 mg/kg/ day, p.o.) along with ISO for 2 weeks. Inflammatory and apoptotic biomarkers were analyzed, which were validated using histochemical analysis. Results: ISO caused renal dysfunction, which manifested as elevated urea, creatinine and uric acid, besides cystatin c and MAPK protein overexpression. In addition, ISO induced gene expression of Fas and lipocalin-2 and provoked genomic DNA fragmentation in renal tissues as compared with the control group. Histological examination confirmed morphological alterations of the kidney tissues obtained from the ISO group. Concurrent treatment of either RES or L-RES with ISO significantly ameliorated kidney damage as demonstrated by the improvement of all measured parameters with the best results for L-RES. The histopathological findings were correlated with the above biochemical parameters. Conclusion: L-RES could be a promising approach for the prevention of kidney injury induced by ISO, most likely via the downregulation of MAPK, cystatin c, Fas, and lipocalin-2.

Electronic cigarette vapor disrupts key metabolic pathways in human lung epithelial cells.

The steady increase in the use of electronic cigarettes (ECs) has reached an epidemic level, increasing mortality and morbidity, mainly due to pulmonary toxicity. Several mechanisms are involved in EC-induced toxicity, including oxidative stress and increased inflammation. Concurrently, the integrity of cellular metabolism is essential for cellular homeostasis and mitigation of toxic insults. However, the effects of EC on cellular metabolism remain largely unknown. In this study, we investigated the metabolic changes induced by EC in human lung epithelial cells (A549) using an untargeted metabolomics approach. A549 cells were exposed to increasing EC vapor extract concentrations, and cell viability, oxidative stress, and metabolomic changes were assessed. Our findings show that ECs induce cell death and increase oxidative stress in a concentration-dependent manner. Metabolomic studies demonstrated that ECs induce unique metabolic changes in key cellular metabolic pathways. Our results revealed that exposure to ECs induced clear segregation in metabolic responses which is driven significantly by number of essential metabolites such as aminoacids, fatty acids, glutathione, and pyruvate. Interstingly, our metabolomics results showed that each concentration of ECs induced unqiues pattern of metabolic changes, suggesting the complexity of ECs induced cytotoxcity. Disrupted metabolites were linked to essential cellular pathways, such as fatty acid biosynthesis, as well as glutathione, pyruvate, nicotinate and nicotinamide, and amino acid metabolisms. These results highlight the potential adverse effects of ECs on cellular metabolism and emphasize the need for further research to fully understand the long-term consequences of EC use. Overall, this study demonstrates that ECs not only induce cell death and oxidative stress but also disrupt cellular metabolism in A549 lung epithelial cells.

Roles of Nrf2/HO-1 and ICAM-1 in the Protective Effect of Nano-Curcumin against Copper-Induced Lung Injury.

Copper (Cu) is an essential trace element for maintaining normal homeostasis in living organisms. Yet, an elevated level of Cu beyond homeostatic capacity may lead to oxidative damage of cellular components in several organs, including the lungs. This work investigated the effects of curcumin (Curc) and nano-curcumin (nCurc) against Cu-induced lung injury, accenting the roles of oxidative stress, inflammation, and the nuclear factor erythroid 2-related factor/heme oxygenase-1 Nrf2/HO-1 pathway. Rats were challenged with 100 mg/kg of copper sulfate (CuSO4) while being treated with Curc or nCurc for 7 days. Cu-triggered lung oxidative stress detected as dysregulation of oxidative/antioxidant markers, a downregulation of Nrf-2/HO-1 signaling, and an increase in the inflammatory markers interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and intracellular adhesion molecule-1 (ICAM-1). Additionally, it decreased the expression of lung-specific proteins, surfactant protein-C (SP-C), and mucin-1 (MUC-1), induced apoptosis, and caused changes in lung histology. Curc and nCurc alleviated CuSO4-induced lung injury by suppressing oxidative damage and inflammation and activating Nrf-2/HO-1. They also prevented apoptosis and restored the normal expression of SP-C and MUC-1. We concluded that nCurc exhibited superior efficacy compared with Curc in mitigating CuSO4-induced lung injury. This was associated with reduced oxidative stress, inflammation, and apoptotic responses and increased Nrf2/HO-1 signaling and expression of SP-C and MUC-1.