Targeting subcellular organelle with multilevel damage has shown great promise for antitumor therapy. Here, we report a core-shell type of nanoagent with iron (III) carboxylate metal-organic ...frameworks (MOFs) as shell while upconversion nanoparticles (UCNPs) as core, which enables near-infrared (NIR) light-triggered synergistically reinforced oxidative stress and calcium overload to mitochondria. The folate decoration on MOFs shells enables efficient cellular uptake of nanoagents. Based on the upconversion ability of UCNPs, NIR light mediates Fe
-to-Fe
reduction and simultaneously activates the photoacid generator (pHP) encapsulated in MOFs cavities, which enables release of free Fe
and acidification of intracellular microenvironment, respectively. The overexpressed H
O
in mitochondria, highly reactive Fe
and acidic milieu synergistically reinforce Fenton reactions for producing lethal hydroxyl radicals (•OH) while plasma photoacidification inducing calcium influx, leading to mitochondria calcium overload. The dual-mitochondria-damage-based therapeutic potency of the nanoagent has been unequivocally confirmed in cell- and patient-derived tumor xenograft models in vivo.
Summary Treatments for acute ischaemic stroke continue to evolve after the superior value of endovascular thrombectomy was confirmed over systemic thrombolysis. Unfortunately, numerous ...neuroprotective drugs have failed to show benefit in the treatment of acute ischaemic stroke, making the search for new treatments imperative. Increased awareness of the relevance of rigorous preclinical testing, and appropriate selection of study participants, might overcome the barriers to progress in stroke research. Relevant areas of interest include the search for safe and effective treatment strategies that combine neuroprotection reperfusion, better use of advanced brain imaging for patient selection, and wider implementation of prehospital conducted clinical trials. Randomised controlled trials of combination treatments completed within the past 5 years have included growth factors, hypothermia, minocycline, natalizumab, fingolimod, and uric acid; the latter two drugs with alteplase produced encouraging results. Blocking of excitotoxicity is also being reassessed in clinical trials with new approaches, such as the postsynaptic density-95 inhibitor NA-1, or peritoneal dialysis to remove excess glutamate. The findings of these randomised trials are anticipated to improve treatment options and clinical outcomes in of patients with acute stroke.
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•Milk-derived bioactive peptides inhibit lipid peroxidation in Caco-2 cells.•Antioxidant effect of bioactive peptides is exerted activating Nrf2 pathway.•Milk-derived bioactive ...peptides induce overexpression of phase II enzymes.•Docking simulation shows that K-8-K disrupts the Keap1-Nrf2 interaction.
Bioactive peptides are relevant nutritional factors that exhibit many functions including antioxidant, antihypertensive, anticancer and antimicrobial properties. In this paper, four synthetic peptides ARHPHPHLSFM (A-11-M), AVPYPQR (A-7-R), NPYVPR (N-6-R) and KVLPVPEK (K-8-K) with sequences present in milk proteins were examined for their antioxidant properties. The compounds show moderate free radical scavenging activity in the ABTS and crocin assays (A-7-R and N-6-R) and lipid peroxidation inhibition in Caco-2 cells (N-6-R and K-8-K). All peptides, in particular K-8-K, activate the Keap1-Nrf2 system by allowing the translocation of the transcription factor Nrf2 from the cytosol to nucleus. This activation triggers the overexpression of the antioxidant enzymes Trx1, TrxR1, GR, NQO1 and SOD1. Furthermore, molecular modeling shows that K-8-K is able to hinder the interaction of Nrf2 with Keap1. The reported results show that the antioxidant action in cells of these bioactive peptides is mostly due to the activation of Keap1-Nrf2 signaling pathway.
Abstract The concept of mild chronic vascular inflammation as part of the pathophysiology of cardiovascular disease, most importantly hypertension and atherosclerosis, has been well accepted. Indeed ...there are links between vascular inflammation, endothelial dysfunction and oxidative stress. However, there are still gaps in our understanding regarding this matter that might be the cause behind disappointing results of antioxidant therapy for cardiovascular risk factors in large-scale long-term randomised controlled trials. Apart from the limitations of our knowledge, limitations in methodology and assessment of the body's endogenous and exogenous oxidant-antioxidant status are a serious handicap. The pleiotropic effects of antioxidant and anti-inflammation that are shown by some well-established antihypertensive agents and statins partly support the idea of using antioxidants in vascular diseases as still relevant. This review aims to provide an overview of the links between oxidative stress, vascular inflammation, endothelial dysfunction and cardiovascular risk factors, importantly focusing on blood pressure regulation and atherosclerosis. In view of the potential benefits of antioxidants, this review will also examine the proposed role of vitamin C, vitamin E and polyphenols in cardiovascular diseases as well as the success or failure of antioxidant therapy for cardiovascular diseases in clinical trials.
Autophagy is a major pathway for degradation of cytoplasmic proteins and organelles, and has been implicated in tumor suppression. Here, we report that mice with systemic mosaic deletion of Atg5 and ...liver-specific Atg7⁻/⁻ mice develop benign liver adenomas. These tumor cells originate autophagy-deficient hepatocytes and show mitochondrial swelling, p62 accumulation, and oxidative stress and genomic damage responses. The size of the Atg7⁻/⁻ liver tumors is reduced by simultaneous deletion of p62. These results suggest that autophagy is important for the suppression of spontaneous tumorigenesis through a cell-intrinsic mechanism, particularly in the liver, and that p62 accumulation contributes to tumor progression.
The effects of current treatment strategies for ischemic stroke are weakened by ischemia-reperfusion (I/R) injury. Effective treatments targeting I/R injury are still insufficient. Adiponectin (APN), ...a fat-derived hormone, has a wide range of antioxidative and anti-inflammatory effects. However, the application of APN to the central nervous system is restricted by its limited blood-brain barrier permeability. Therefore, an adiponectin peptide (APNp) was chemically synthesized on the basis of the functional area in the APN structure. The present study was carried out to explore the effect and the underlying mechanism of APNp on I/R injury. A transient middle cerebral artery occlusion (tMCAO) model with C57BL/6 J mice was used, and an in vitro oxygen-glucose deprivation and reintroduction (OGD-R) model with primary astrocytes was induced. The results showed that APNp decreased the cerebral infarction volume, alleviated brain edema, improved neurological function and had antioxidative, anti-inflammatory, and antiapoptotic effects against cerebral I/R injury. In addition, APNp upregulated the phosphorylation of AMPK and GSK-3β, promoted the nuclear translocation of Nrf2 and increased the expression of Trx1. The protective effect of APNp was abolished by compound C, a selective AMPK inhibitor, and PX-12, a selective Trx inhibitor. Moreover, APNp decreased the protein level of TXNIP and suppressed the activation of the NLRP3 inflammasome in astrocytes, which were also reversed by compound C and PX-12. These findings suggest that APNp, as a potential substitute for adiponectin, has a great potential for clinical application in the treatment of acute brain ischemia.
Selenoprotein glutathione peroxidase 4 (GPX4) serves as a crucial suppressor of oxidative stress-induced ferroptosis, making it an attractive target for disease therapy. Here, we discuss recent ...strategies and challenges associated with targeting GPX4 through covalent inhibitors, proteolysis targeting chimera (PROTAC) degraders, and cell-type-specific degraders in the context of cancer.
Selenoprotein glutathione peroxidase 4 (GPX4) serves as a crucial suppressor of oxidative stress-induced ferroptosis, making it an attractive target for disease therapy. Here, we discuss recent strategies and challenges associated with targeting GPX4 through covalent inhibitors, proteolysis targeting chimera (PROTAC) degraders, and cell-type-specific degraders in the context of cancer.
Forkhead box O (FOXO) transcription factors are involved in the regulation of the cell cycle, apoptosis and metabolism. In model organisms, FOXO activity also affects stem cell maintenance and ...lifespan as well as age-related diseases, such as cancer and diabetes. Multiple upstream pathways regulate FOXO activity through post-translational modifications and nuclear-cytoplasmic shuttling of both FOXO and its regulators. The diversity of this upstream regulation and the downstream effects of FOXOs suggest that they function as homeostasis regulators to maintain tissue homeostasis over time and coordinate a response to environmental changes, including growth factor deprivation, metabolic stress (starvation) and oxidative stress.
Widely used in biomedical and bioanalytical applications, the detonation nanodiamonds (NDs) are generally considered to be biocompatible and non-toxic to a wide range of eukaryotic cells. Due to ...their high susceptibility to chemical modifications, surface functionalisation is often used to tune the biocompatibility and antioxidant activity of the NDs. The response of photosynthetic microorganisms to redox-active NDs is still poorly understood and is the focus of the present study. The green microalga Chlamydomonas reinhardtii was used to assess the potential phytotoxicity and antioxidant activity of NDs hosting hydroxyl functional groups at concentrations of 5-80 μg NDs/mL. The photosynthetic capacity of microalgae was assessed by measuring the maximum quantum yield of PSII photochemistry and the light-saturated oxygen evolution rate, while oxidative stress was assessed by lipid peroxidation and ferric-reducing antioxidant capacity. We demonstrated that hydroxylated NDs might reduce cellular levels of oxidative stress, protect PSII photochemistry and facilitate the PSII repair under methyl viologen and high light associated stress conditions. Factors involved in this protection may include the low phytotoxicity of hydroxylated NDs in microalgae and their ability to accumulate in cells and scavenge reactive oxygen species. Our findings could pave the way for using hydroxylated NDs as antioxidants to improve cellular stability in algae-based biotechnological applications or semi-artificial photosynthetic systems.
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