Oxidative status in neuroblastoma: a source of stress?

Microwave-Assisted Extraction of Bioactive Compounds from Lentil Wastes: Antioxidant Activity Evaluation and Metabolomic Characterization

The recovery of industrial by-products is part of the zero-waste circular economy. Lentil seed coats are generally considered to be a waste by-product. However, this low-value by-product is rich in bioactive compounds and may be considered an eco-friendly source of health-promoting phytochemicals. For the first time, a sustainable microwave-assisted extraction technique was applied, and a solvent screening was carried out to enhance the bioactive compound content and the antioxidant activity of green and red lentil hull extracts. With respect to green lentil hull extracts that were obtained with different solvents, the aqueous extract of the red lentil seed coats showed the highest total phenolic and total flavonoid content (TPC = 28.3 ± 0.1 mg GAE/g dry weight, TFC = 1.89 ± 0.01 mg CE/100 mg dry weight, respectively), as well as the highest antioxidant activity, both in terms of the free radical scavenging activity (ABTS, 39.06 ± 0.73 mg TE/g dry weight; DPPH, IC50 = 0.39 μg/mL) and the protection of the neuroblastoma cell line (SH-SY5Y, IC50 = 10.1 ± 0.6 μg/mL), the latter of which has never been investigated so far. Furthermore, a metabolite discovery analysis was for the first time performed on the aqueous extracts of both cultivars using an HPLC separation which was coupled with an Orbitrap-based high-Resolution Mass Spectrometry technique.

Plasma membrane integrity in health and disease: significance and therapeutic potential

Maintenance of plasma membrane integrity is essential for normal cell viability and function. Thus, robust membrane repair mechanisms have evolved to counteract the eminent threat of a torn plasma membrane. Different repair mechanisms and the bio-physical parameters required for efficient repair are now emerging from different research groups. However, less is known about when these mechanisms come into play. This review focuses on the existence of membrane disruptions and repair mechanisms in both physiological and pathological conditions, and across multiple cell types, albeit to different degrees. Fundamentally, irrespective of the source of membrane disruption, aberrant calcium influx is the common stimulus that activates the membrane repair response. Inadequate repair responses can tip the balance between physiology and pathology, highlighting the significance of plasma membrane integrity. For example, an over-activated repair response can promote cancer invasion, while the inability to efficiently repair membrane can drive neurodegeneration and muscular dystrophies. The interdisciplinary view explored here emphasises the widespread potential of targeting plasma membrane repair mechanisms for therapeutic purposes.

Cytokine and microRNA levels during different periods of paradoxical sleep deprivation and sleep recovery in rats

Background

Sleep has a fundamental role in the regulation of homeostasis. The aim of this study was to assess the effect of different periods of paradoxical sleep deprivation (PSD) and recovery on serum levels of cytokines and miRNAs related to inflammatory responses.

Methods

Male Wistar rats were submitted to a PSD of 24, 96, or 192 h, or of 192 h followed by 20 days of recovery (192 h PSD+R). The concentrations of corticosterone, cytokines (IL-6, TNF, IL-10, Adiponectin) and miRNAs (miR-146a, miR-155, miR-223, miR-16, miR-126, miR-21) in serum were evaluated.

Results

At PSD 24 h a significant increase of IL-6 and decrease of IL-10 were observed. At PSD 96h adiponectin increased. At 192 h of PSD IL-6 increased significantly again, accompanied by a threefold increase of IL-10 and an increase of serum corticosterone. After 20 days of recovery (192 h PSD+R) corticosterone, IL-6 and TNF levels increased significantly, while IL-10 decreased also significantly. Regarding the miRNAs at 24 h of PSD serum miR-146a, miR-155, miR-223, and miR-16 levels all increased. At 96 h of PSD miR-223 decreased. At 192 h of PSD decreases in miR-16 and miR-126 were observed. After recovery serum miR-21 increased and miR-16 decreased.

Conclusion

PSD induces a dynamic response likely reflecting the induced cellular stress and manifested as variating hormonal and inflammatory responses. Sleep deprivation disturbed corticosterone, cytokine and miRNA levels in serum related to the duration of sleep deprivation, as short-term PSD produced effects similar to those of an acute inflammatory response and long-term PSD induced long-lasting disturbances of biological mediators.

Vitamin E d-α-Tocopheryl Polyethylene Glycol Succinate (TPGS) Provokes Cell Death in Human Neuroblastoma SK-N-SH Cells via a Pro-Oxidant Signaling Mechanism

Neuroblastoma (NB) is the most common neoplasm during infancy. Unfortunately, NB is still a lethal cancer. Therefore, innovative curative therapies are immediately required. In this study, we showed the prodeath activity of TPGS in human NB SK-N-SH cancer cells. NB cells were exposed to TPGS (10-80 μM). We report for the first time that TPGS induces cell death by apoptosis in NB cells via a pro-oxidant-mediated signaling pathway. Certainly, H₂O₂ directly oxidizes DJ-1 cysteine¹⁰⁶-thiolate into DJ-1 cysteine¹⁰⁶-sulfonate, indirectly activates the transcription factors NF-kappaB, p53, and c-JUN, induces the upregulation of mitochondria regulator proteins BAX/PUMA, and provokes the loss of mitochondrial membrane potential (ΔΨ_m) and the activation of caspase-3/AIF, leading to nuclear disintegration, demonstrated by cellular and biochemical techniques such as fluorescence microscopy, flow cytometry, and Western blot analysis. Since TPGS is a U.S. Food and Drug Administration (FDA)-approved pharmaceutical excipient, this molecule might be used in clinical trials for NB treatment.

2-deoxy-D-glucose induces oxidative stress and cell killing in human neuroblastoma cells

Malignant cells have a demonstrably greater sensitivity to glucose deprivation-induced cytotoxicity than normal cells. This has been hypothesized to be due to a higher level of reactive oxygen species (ROS) production in cancer cells leading to the increased need for reducing equivalents, produced by glucose metabolism, to detoxify hydroperoxides. Because complete glucose deprivation cannot be achieved in vivo, it has been proposed that agents that antagonize glucose metabolism, such as 2-deoxy-D-glucose (2DG), can mimic in vitro glucose deprivation that selectively kills cancer cells by oxidative stress. To test this hypothesis, neuroblastoma cell lines were treated with 2DG and the effects on clonogenic survival and the distribution of cellular phenotypes among surviving colonies was determined. The results showed that all three major cell types found in neuroblastoma (Schwann, Neuronal and Intermediate) were sensitive to 2DG-induced clonogenic cell killing. Furthermore, treatment with the thiol antioxidant, N-acetyl cysteine or with polyethylene glycol-conjugated superoxide dismutase and catalase, protected neuroblastoma cells from 2DG-induced cell killing. Finally normal non-immortalized neural precursor cells were relatively resistant to 2DG-induced cell killing when compared to neuroblastoma cell lines. These results support the hypothesis that inhibitors of glucose metabolism could represent useful adjuvants in the treatment of neuroblastoma by selectively enhancing metabolic oxidative stress.

Proteomic approaches in neuroblastoma: a complementary clinical platform for the future

Neuroblastoma (NB) is one of the most common solid tumors of childhood and displays a remarkable diversity in both biologic characteristics and clinical outcomes. Availability of high-throughput 'omics technologies and their subsequent application towards oncology has provided insight into the complex pathways of tumor formation and progression. Investigation of NB 'omics profiles may better define tumor behavior and provide targeted therapy with the goal of improving outcomes in patients with high-risk disease. Utilization of these technologies in NB has already led to advances in classification and risk stratification. The gradual emergence of NB-directed proteomics adds a layer of intricacy to the analysis of biologic organization but may ultimately provide a better comprehension of this complex disease. In this review, we cite specific examples of how NB-directed proteomics has provided information regarding novel biomarkers and possible therapeutic targets. We finish by examining the impact of high-throughput 'omics in the field of NB and speculate on how these emerging technologies may further be incorporated into the discipline.