ROS and p53: a versatile partnership

mTOR: A Potential New Target in Nonalcoholic Fatty Liver Disease

The global prevalence of nonalcoholic fatty liver disease (NAFLD) continues to rise, yet effective treatments are lacking due to the complex pathogenesis of this disease. Although recent research has provided evidence for the “multiple strikes” theory, the classic “two strikes” theory has not been overturned. Therefore, there is a crucial need to identify multiple targets in NAFLD pathogenesis for the development of diagnostic markers and targeted therapeutics. Since its discovery, the mechanistic target of rapamycin (mTOR) has been recognized as the central node of a network that regulates cell growth and development and is closely related to liver lipid metabolism and other processes. This paper will explore the mechanisms by which mTOR regulates lipid metabolism (SREBPs), insulin resistance (Foxo1, Lipin1), oxidative stress (PIG3, p53, JNK), intestinal microbiota (TLRs), autophagy, inflammation, genetic polymorphisms, and epigenetics in NAFLD. The specific influence of mTOR on NAFLD was hypothesized to be divided into micro regulation (the mechanism of mTOR’s influence on NAFLD factors) and macro mediation (the relationship between various influencing factors) to summarize the influence of mTOR on the developmental process of NAFLD, and prove the importance of mTOR as an influencing factor of NAFLD regarding multiple aspects. The effects of crosstalk between mTOR and its upstream regulators, Notch, Hedgehog, and Hippo, on the occurrence and development of NAFLD-associated hepatocellular carcinoma are also summarized. This analysis will hopefully support the development of diagnostic markers and new therapeutic targets in NAFLD.

Adaptive and Pathological Outcomes of Radiation Stress-Induced Redox Signaling

Significance: Ionizing radiation can damage cells either directly or through oxidative damage caused by ionization. Although radiation exposure from natural sources is very limited, ionizing radiation in nuclear disaster zones and long spaceflights causes inconspicuous, yet measurable physiological effects in men and animals, whose significance remains poorly known. Understanding the physiological impacts of ionizing radiation has a wide importance due to the increased use of medical imaging and radiotherapy. Recent Advances: Radiation exposure has been traditionally investigated from the perspective of DNA damage and its consequences. However, recent studies from Chernobyl as well as spaceflights have provided interesting insights into oxidative stress-induced metabolic alterations and disturbances in the circadian regulation. Critical Issues: In this review, we discuss the physiological consequences of radiation exposure in the light of oxidative stress signaling. Radiation exposure likely triggers many converging or interconnecting signaling pathways, some of which mimic mitochondrial dysfunction and might explain the observed metabolic changes. Future Directions: Better understanding of the different radiation-induced signaling pathways might help to devise strategies for mitigation of the long-term effects of radiation exposure. The utility of fibroblast growth factor 21 (FGF21) as a radiation exposure biomarker and the use of radiation hormesis as a method to protect astronauts on a prolonged spaceflight, such as a mission to Mars, should be investigated. Antioxid. Redox Signal. 37, 336-348.

ROS-activated CXCR2+ neutrophils recruited by CXCL1 delay denervated skeletal muscle atrophy and undergo P53-mediated apoptosis

Neutrophils are the earliest master inflammatory regulator cells recruited to target tissues after direct infection or injury. Although inflammatory factors are present in muscle that has been indirectly disturbed by peripheral nerve injury, whether neutrophils are present and play a role in the associated inflammatory process remains unclear. Here, intravital imaging analysis using spinning-disk confocal intravital microscopy was employed to dynamically identify neutrophils in denervated muscle. Slice digital scanning and 3D-view reconstruction analyses demonstrated that neutrophils escape from vessels and migrate into denervated muscle tissue. Analyses using reactive oxygen species (ROS) inhibitors and flow cytometry demonstrated that enhanced ROS activate neutrophils after denervation. Transcriptome analysis revealed that the vast majority of neutrophils in denervated muscle were of the CXCR2 subtype and were recruited by CXCL1. Most of these cells gradually disappeared within 1 week via P53-mediated apoptosis. Experiments using specific blockers confirmed that neutrophils slow the process of denervated muscle atrophy. Collectively, these results indicate that activated neutrophils are recruited via chemotaxis to muscle tissue that has been indirectly damaged by denervation, where they function in delaying atrophy.

Live animal imaging experiments reveal how rapid recruitment of a subset of immune cells helps prevent muscle wasting after peripheral nerve injury. Such injuries take considerable time to heal, and there are no therapies that reliably prevent wasting of muscle lacking nervous innervation. Researchers led by JunJian Jiang and Jianguang Xu at Fudan University, Shanghai, China, have used intravital microscopy to record the cellular and molecular events that follow nerve damage in live mice. They observed heightened production of chemicals that summon immune cells known as neutrophils to the site of the injury. Even though the surrounding muscle cells were initially undamaged in this animal model, the recruited neutrophils delayed subsequent muscle wasting. This neutrophil recruitment was transient, but therapies that elicit a more sustained response could provide durable protection against muscle wasting.

Role of p53 in Regulating Radiation Responses

p53 is known as the guardian of the genome and plays various roles in DNA damage and cancer suppression. The p53 gene was found to express multiple p53 splice variants (isoforms) in a physiological, tissue-dependent manner. The various genes that up- and down-regulated p53 are involved in cell viability, senescence, inflammation, and carcinogenesis. Moreover, p53 affects the radioadaptive response. Given that several studies have already been published on p53, this review presents its role in the response to gamma irradiation by interacting with MDM2, NF-κB, and miRNA, as well as in the inflammation processes, senescence, carcinogenesis, and radiation adaptive responses. Finally, the potential of p53 as a biomarker is discussed.

p66Shc Deficiency in Chronic Lymphocytic Leukemia Promotes Chemokine Receptor Expression Through the ROS-Dependent Inhibition of NF-κB

The microenvironment of lymphoid organs is central to the pathogenesis of chronic lymphocytic leukemia (CLL). Within it, tumor cells find a favourable niche to escape immunosurveillance and acquire pro-survival signals. We have previously reported that a CLL-associated defect in the expression of the pro-apoptotic and pro-oxidant adaptor p66Shc leads to enhanced homing to and accumulation of leukemic cells in the lymphoid microenvironment. The p66Shc deficiency-related impairment in intracellular reactive oxygen species (ROS) production in CLL cells is causally associated to the enhanced expression of the chemokine receptors CCR2, CXCR3 and CCR7, that promote leukemic cell homing to both lymphoid and non-lymphoid organs, suggesting the implication of a ROS-modulated transcription factor(s). Here we show that the activity of the ROS-responsive p65 subunit of the transcription factor NF-κB was hampered in the CLL-derived cell line MEC-1 expressing a NF-κB-luciferase reporter following treatment with H2O2. Similar results were obtained when intracellular ROS were generated by expression of p66Shc, but not of a ROS-defective mutant, in MEC-1 cells. NF-κB activation was associated with increased expression of the chemokine receptors CCR2, CXCR3 and CCR7. Reconstitution of p66Shc in CLL cells normalized intracellular ROS and hampered NF-κB activation, which led to a decrease in the expression of these homing receptors. Our data provide direct evidence that the p66Shc-deficiency-related ROS depletion in CLL cells concurs to NF-κB hyperactivation and homing receptor overexpression, providing a mechanistic basis for the enhanced ability of these cells to accumulate in the pro-survival lymphoid niche.

ROS and miRNA Dysregulation in Ovarian Cancer Development, Angiogenesis and Therapeutic Resistance

The diverse repertoires of cellular mechanisms that progress certain cancer types are being uncovered by recent research and leading to more effective treatment options. Ovarian cancer (OC) is among the most difficult cancers to treat. OC has limited treatment options, especially for patients diagnosed with late-stage OC. The dysregulation of miRNAs in OC plays a significant role in tumorigenesis through the alteration of a multitude of molecular processes. The development of OC can also be due to the utilization of endogenously derived reactive oxygen species (ROS) by activating signaling pathways such as PI3K/AKT and MAPK. Both miRNAs and ROS are involved in regulating OC angiogenesis through mediating multiple angiogenic factors such as hypoxia-induced factor (HIF-1) and vascular endothelial growth factor (VEGF). The NAPDH oxidase subunit NOX4 plays an important role in inducing endogenous ROS production in OC. This review will discuss several important miRNAs, NOX4, and ROS, which contribute to therapeutic resistance in OC, highlighting the effective therapeutic potential of OC through these mechanisms.

Receptor interacting protein 1 knockdown induces cell death in liver cancer by suppressing STAT3/ATR activation in a p53-dependent manner

The survival and death of eukaryotic cells are tightly controlled by a variety of proteins in response to the cellular environment. Receptor-interacting serine/threonine-protein kinase 1 (RIPK1) is a receptor-interacting Ser/Thr kinase that has recently been reported as an important regulator of cell survival, apoptosis, and necroptosis; however, its role in liver cancer remains unclear. In this study, we examined the effect of siRNA-mediated RIPK1 knockdown on the survival and death of liver cancer cells. Treatment with siRIPK1 decreased the growth rate of liver cancer cells and increased apoptotic, but not necrotic cell death, which was higher in wild-type p53 (wt-p53) cells than in mutant-type p53 (mt-p53) cells. In addition, RIPK1 knockdown increased p53 expression and G1 phase arrest in wt-p53 cells. Although suppressing p53 did not alter RIPK1 expression, it did attenuate siRIPK1-induced cell death. Interestingly, RIPK1 knockdown also increased the generation of reactive oxygen species and DNA damage by inhibiting signal transduced and activator of transcription 3 (STAT3) and ATM and RAD3-related (ATR) in wt-p53 cells but not in mt-p53 cells. Moreover, STAT3 or ATR inhibition in p53 mutant cells restored siRIPK1-mediated cell death. Together, the results of this study suggest that RIPK1 suppression induces apoptotic cell death by inhibiting the STAT3/ATR axis in a p53-dependent manner. Furthermore, these findings suggest that RIPK1, alone or in combination, may be a promising target for treating liver cancer.

Cisplatin Chemotherapy and Cochlear Damage: Otoprotective and Chemosensitization Properties of Polyphenols

Significance: Cisplatin is an important component of treatment regimens for different cancers. Notwithstanding that therapeutic success often results from partial efficacy or stabilizing the disease, chemotherapy failure is driven by resistance to drug treatment and occurrence of side effects, such as progressive irreversible ototoxicity. Cisplatin's side effects, including ototoxicity, are often dose limiting. Recent Advances: Cisplatin ototoxicity results from several mechanisms, including redox imbalance caused by reactive oxygen species production and lipid peroxidation, activation of inflammation, and p53 and its downstream pathways that culminate in apoptosis. Considerable efforts in research have targeted development of molecular interventions that can be concurrently administered with cisplatin or other chemotherapies to reduce side effect toxicities while preserving or enhancing the antineoplastic effects. Evidence from studies has indicated some polyphenols, such as curcumin, can help to regulate redox signaling and inflammatory effects. Furthermore, polyphenols can exert opposing effects in different types of tissues, that is, normal cells undergoing stressful conditions versus cancer cells. Critical Issues: This review article summarizes evidence of curcumin antioxidant effect against cisplatin-induced ototoxicity that is converted to a pro-oxidant activity in cisplatin-treated cancer cells, thus providing an ideal chemosensitivity combined with otoprotection. Polyphenols can modulate the adaptive responses to stress in the cisplatin-exposed cochlea. These adaptive effects can result from the interaction/cross talk between the cell's defenses, inflammatory molecules, and the key signaling molecules of signal transducers and activators of transcription 3 (STAT-3), nuclear factor κ-B (NF-κB), p53, and nuclear factor erythroid 2-related factor 2 (Nrf-2). Future Directions: We provide molecular evidence for alternative strategies for chemotherapy with cisplatin addressing the otoprotection and chemosensitization properties of polyphenols. Antioxid. Redox Signal. 36, 1229-1245.

Nimbolide retards T cell lymphoma progression by altering apoptosis, glucose metabolism, pH regulation, and ROS homeostasis

Nimbolide is reported as one of the potential anticancer candidates of the neem tree (Azadirachta indica A. Juss). The cytotoxic action of nimbolide has been well reported against a wide number of malignancies, including breast, prostate, lung, liver, and cervix cancers. Interestingly, only a few in vivo studies conducted on B cell lymphoma, glioblastoma, pancreatic cancer, and buccal pouch carcinoma have shown the in vivo antitumor efficacy of nimbolide. Therefore, it is highly needed to examine the in vivo antineoplastic activity of nimbolide on a wide variety of cancers to establish nimbolide as a promising anticancer drug. In the present study, we investigated the tumor retarding action of nimbolide in a murine model of T cell lymphoma. We noticed significantly augmented apoptosis in nimbolide- administered tumor-bearing mice, possibly due to down-regulated expression of Bcl2 and up-regulated expression of p53, cleaved caspase-3, Cyt c, and ROS. The nimbolide treatment-induced ROS production by suppressing the expression of antioxidant regulatory enzymes, namely superoxide dismutase and catalase. In addition, nimbolide administration impaired glycolysis and pH homeostasis with concomitant inhibition of crucial glycolysis and pH regulatory molecules such as GLUT3, LDHA, MCT1, and V-ATPase, CAIX and NHE1, respectively. Taken together, the present investigation provides novel insights into molecular mechanisms of nimbolide inhibited T cell lymphoma progression and directs the utility of nimbolide as a potential anticancer therapeutic drug for the treatment of T cell lymphoma.

Ginsenoside Rh4 Inhibits Colorectal Cancer Cell Proliferation by Inducing Ferroptosis via Autophagy Activation

Colorectal cancer (CRC) is a severe threat to human health. Ginsenosides such as ginsenoside Rh4 have been widely studied in the antitumor field. Here, we investigated the antiproliferative activity and mechanism of Rh4 against CRC in vivo and in vitro. The CRC xenograft model showed that Rh4 inhibited xenograft tumor growth with few side effects (p < 0.05). As determined by MTT colorimetric assays, Western blotting, and immunohistochemical analysis, Rh4 effectively inhibited CRC cell proliferation through autophagy and ferroptosis (p < 0.05). Rh4 significantly upregulated autophagy and ferroptosis marker expression in CRC cells and xenograft tumor tissues in the present study (p < 0.05). Interestingly, the ferroptosis inhibitor ferrostatin-1 (Fer-1) reversed Rh4-induced ferroptosis (p < 0.05). Moreover, the autophagy inhibitor 3-methyladenine (3-MA) also reversed Rh4-induced ferroptosis (p < 0.05). These results indicate that Rh4-induced ferroptosis is regulated via the autophagy pathway. In addition, Rh4 increased reactive oxygen species (ROS) accumulation, leading to the activation of the ROS/p53 signaling pathway (p < 0.05). Transcriptome sequencing also confirmed this (p < 0.05). Moreover, the ROS scavenger N-acetyl-cysteine (NAC) reversed the inhibitory effect of Rh4 on CRC cells (p < 0.05). Therefore, this study proves that Rh4 inhibits cancer cell proliferation by activating the ROS/p53 signaling pathway and activating autophagy to induce ferroptosis, which provides necessary scientific evidence of the great anticancer potential of Rh4.

Construction of a Silver Nanoparticle Complex and its Application in Cancer Treatment

Nanomedicine has been used in tumor treatment and research due to its advantages of targeting, controlled release and high absorption rate. Silver nanoparticle (AgNPs), with the advantages of small particle size, and large specific surface area, are of great potential value in suppressing and killing cancer cells. Methods: AgNPs–polyethyleneimine (PEI) –folate (FA) (AgNPs–PF) were synthesised and characterised by several analytical techniques. The ovarian cancer cell line Skov3 was used as the cell model to detect the tumor treatment activity of AgNPs, AgNPs–PF and AgNPs+ AgNPs–PF. Results: Results shown that AgNPs–PF were successfully constructed with uniform particle size of 50–70 nm. AgNPs, AgNPs–PF, AgNPs–PF+ AgNPs all showed a certain ability to inhibit cancer cell proliferation, increase reactive oxygen species and decrease the mitochondrial membrane potential. All AgNPs, AgNPs–PF, AgNPs+ AgNPs–PF promoted DNA damage in Skov3 cells, accompanied by the generation of histone RAD51 and γ-H2AX site, and eventually leading to the apoptosis of Skov3 cells. The combination of AgNPs–PF and AgNPs had a more pronounced effect than either material alone. Conclusion: This study is to report that the combination of AgNPs+ AgNPs–PF can cause stronger cytotoxicity and induce significantly greater cell death compared to AgNPs or AgNPs–PF alone in Skov3 cells. Therefore, the combined application of drugs could be the best way to cancer treatment.

A time-dependently regulated gene network reveals that Aspergillus protease affects mitochondrial metabolism and airway epithelial cell barrier function via mitochondrial oxidants

The airway epithelium maintains tight barrier integrity to prevent penetration of pathogens; thus, impairment of the barrier function is an important and common histological feature in asthmatic patients. Proteolytic allergens from fungi, pollen, and house dust mites can disrupt epithelial barrier integrity, but the mechanism remains unclear. Aspergillus oryzae protease (AP)-induced mitochondrial reactive oxygen species (ROS) contribute to the epithelial inflammatory response. However, as mitochondrial ROS affect various cellular functions, such as metabolism, cell death, cell proliferation, and redox homeostasis through signal transduction, it is difficult to understand the detailed action mechanism of AP by measuring changes in a single gene or protein of a specific signaling pathway. Moreover, mitochondrial ROS can directly oxidize DNA to activate transcription, thereby affecting the expression of various genes at the transcriptional level. Therefore, we conducted whole-genome analysis and used a network-based approach to understand the effect of AP and AP-induced mitochondrial ROS in human primary airway epithelial cells and to evaluate the mechanistic basis for AP-mediated epithelial barrier dysfunction. Our results indicate that production of mitochondrial ROS following AP exposure induce mitochondrial dysfunction at an early stage. Over time, changes in genome expression were further expanded without remaining mitochondrial ROS. Specifically, genes involved in the apoptotic functions and intercellular junctions were affected, consequently impairing the cellular barrier integrity. This change was recovered by scavenging mitochondrial ROS at an early point after exposure to AP. In conclusion, our findings indicate that instantly increased mitochondrial ROS at the time of exposure to allergenic proteases consequently induces epithelial barrier dysfunction at a later time point, resulting in pathological changes. These data suggest that antioxidant therapy administered immediately after exposure to proteolytic antigens may be effective in maintaining epithelial barrier function.

Magnetic fields and apoptosis: a possible mechanism

The potential therapeutic uses of electromagnetic fields (EMF), part of the nonionizing radiation spectrum, increase with time. Among them, those considering the potential antitumor effects exerted by the Magnetic Fields (MFs), part of the EMF entity, have gained more and more interest. A recent review on this subject reports the MFs' effect on apoptosis of tumor cells as one of the most important breakthroughs. Apoptosis is considered a key mechanism regulating the genetic stability of cells and as such is considered of fundamental importance in cancer initiation and development. According to an atomic/sub-atomic analysis, based on quantum physics, of the complexity of biological life and the role played by oxygen and its radicals in cancer biology, a possible biophysical mechanism is described. The mechanism considers the influence of MFs on apoptosis through an effect on electron spin that is able to increase reactive oxygen species (ROS) concentration. Impacting on the delicate balance between ROS production and ROS elimination in tumor cells is considered a promising cancer therapy, affecting different biological processes, such as apoptosis and metastasis. An analysis in the literature, which allows correlation between MFs exposure characteristics and their influence on apoptosis and ROS concentration, supports the validity of the mechanism.

ROS-Related miRNAs Regulate Immune Response and Chemoradiotherapy Sensitivity in Hepatocellular Carcinoma by Comprehensive Analysis and Experiment

Reactive oxygen species (ROS) plays an essential role in the development of cancer. Here, we chose ROS-related miRNAs for consensus clustering analysis and ROS score construction. We find that ROS is extremely associated with prognosis, tumor immune microenvironment (TIME), gene mutations, N6-methyladenosine (m6A) methylation, and chemotherapy sensitivity in hepatocellular carcinoma (HCC). Mechanistically, ROS may affect the prognosis of HCC patients in numerous ways. Moreover, miR-210-3p and miR-106a-5p significantly increased the ROS level and stagnated cell cycle at G2/M in HCC; the results were more obvious in cells after ionizing radiation (IR). Finally, the two miRNAs suppressed cell proliferation, migration, and invasion and promoted apoptosis in huh7 and smmc7721 cells. It indicated that ROS might affect the prognosis of HCC patients through immune response and increase the sensitivity of HCC patients to radiotherapy and chemotherapy.

Thiacloprid-induced hepatotoxicity in zebrafish: Activation of the extrinsic and intrinsic apoptosis pathways regulated by p53 signaling pathway

Thiacloprid (THCP) is one of the major neonicotinoid insecticides, and its wide use has led to high detection in various media of aquatic environment, posing potential risks to aquatic organisms. This study was focused on the phenotypic responses and mechanisms of toxicity in zebrafish (Danio rerio) upon treatment with waterborne THCP (0.4, 4 and 40 μM) for 21 days in vivo or 412.9 μM for 24 h in vitro. In vivo, we found that THCP induced severe oxidative stress, hepatic abnormalities, leakage of alanine aminotransferase and aspartate aminotransferase and apoptosis. The analysis of RNA-sequencing suggested the activation of the p53 signaling pathway under THCP exposure. The following in vitro study showed that THCP intoxication activated reactive oxygen species (ROS)-dependent p53 signaling pathway and induced hepatotoxicity in the zebrafish liver cells. The addition of p53 inhibitor pifithrin-α (10 μM) exerted protection against of THCP-induced hepatotoxicity by reducing oxidative stress and inhibiting the p53 signaling pathway and apoptosis. Moreover, gene expression analyses indicated that both the extrinsic and intrinsic apoptosis pathways were involved in apoptosis induced by p53 activation. Overall, our results suggest that activation of the p53 signaling pathway is an important mechanism of THCP-induced hepatotoxicity.

Of the many cellular responses activated by TP53, which ones are critical for tumour suppression?

The tumour suppressor TP53 is a master regulator of several cellular processes that collectively suppress tumorigenesis. The TP53 gene is mutated in ~50% of human cancers and these defects usually confer poor responses to therapy. The TP53 protein functions as a homo-tetrameric transcription factor, directly regulating the expression of ~500 target genes, some of them involved in cell death, cell cycling, cell senescence, DNA repair and metabolism. Originally, it was thought that the induction of apoptotic cell death was the principal mechanism by which TP53 prevents the development of tumours. However, gene targeted mice lacking the critical effectors of TP53-induced apoptosis (PUMA and NOXA) do not spontaneously develop tumours. Indeed, even mice lacking the critical mediators for TP53-induced apoptosis, G1/S cell cycle arrest and cell senescence, namely PUMA, NOXA and p21, do not spontaneously develop tumours. This suggests that TP53 must activate additional cellular responses to mediate tumour suppression. In this review, we will discuss the processes by which TP53 regulates cell death, cell cycling/cell senescence, DNA damage repair and metabolic adaptation, and place this in context of current understanding of TP53-mediated tumour suppression.

Organophosphate flame retardants induce oxidative stress and Chop/Caspase 3-related apoptosis via Sod1/p53/Map3k6/Fkbp5 in NCI-1975 cells

Organophosphate flame retardants (OPFRs) have been ubiquitously detected in dust and air which could cause damage to human health through inhalation. Currently the understanding of their adverse effects and potential mechanisms on the lung are still limited. In this study, human non-small cell lung cancer cell line NCI-H1975 was used to investigate the cytotoxicity, oxidative stress, cellular apoptosis of 9 typical OPFRs with concentrations varied from 0 to 200 μM, and their toxic mechanism associated with molecular structure was compared. After 72 h, tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) displayed the highest cytotoxicity, followed by 2-ethylhexyl diphenyl phosphate (EHDPP), tris(2-butoxyethyl) phosphate (TBOEP) and tris(2-chloroisopropyl) phosphate (TCIPP), while tris(2-chloroethyl) phosphate (TCEP) and tris(2-ethylhexyl) phosphate (TEHP) exhibited the least suppression on cell viability. These results indicated that the variation of cytotoxicity on OPFRs could only be partially explained by their ester linkage. Moreover, the overexpression of intracellular reactive oxygen species (ROS), free Ca²⁺ and cellular apoptosis suggested that exposure to OPFRs can lead to apoptosis related to oxidative stress. Six genes associated with oxidative stress and apoptosis were upregulated dramatically compared with the control, demonstrating OPFRs induced Chop/Caspase 3-related apoptosis by activating Sod1/p53/Map3k6/Fkbp5 expression in NCI-H1975 cells. This is the first study to investigate cytotoxicity and related mechanism on commonly-used OPFRs in NCI-H1975 cells.

Urea transporter B downregulates polyamines levels in melanoma B16 cells via p53 activation

Urea transporter B (UT-B, encoded by the SLC14A1 gene) is a membrane channel protein involved in urea transmembrane transport. Compared with normal tissues, UT-B expression is significantly decreased in most tumours, especially melanoma. However, the UT-B role in tumorigenesis and development is still unclear. Herein, we investigated the effects of UT-B overexpression on polyamine metabolism and the urea cycle in murine melanoma B16 cells, to explore the roles of mitochondrial dysfunction and p53 activation in cell growth and polyamines metabolism. UT-B overexpression in B16 cells decreased cell growth, increased apoptosis, and significantly altered metabolic pathways related to the urea cycle, which were characterized by reduced production of urea and polyamines and increased production of nitric oxide. Subsequently, we observed that activation of the p53 pathway may be the main cause of the above phenomena. The p53 inhibitor pifithrin-α partially restored the production of polyamines, but the mitochondrial morphology and function were still impaired. Further treatment of UT-B-overexpressing B16 cells with reactive oxygen species scavenging agent N-acetyl-l-cysteine and coenzyme Q10 restored cell viability and mitochondrial function and increased polyamine production. In conclusion, UT-B overexpression caused mitochondrial dysfunction and increased oxidative stress in B16 cells, and then activated p53 expression, which may be one of the mechanisms leading to the decrease in intracellular polyamines.

Molecular and functional heterogeneity in dorsal and ventral oligodendrocyte progenitor cells of the mouse forebrain in response to DNA damage

In the developing mouse forebrain, temporally distinct waves of oligodendrocyte progenitor cells (OPCs) arise from different germinal zones and eventually populate either dorsal or ventral regions, where they present as transcriptionally and functionally equivalent cells. Despite that, developmental heterogeneity influences adult OPC responses upon demyelination. Here we show that accumulation of DNA damage due to ablation of citron-kinase or cisplatin treatment cell-autonomously disrupts OPC fate, resulting in cell death and senescence in the dorsal and ventral subsets, respectively. Such alternative fates are associated with distinct developmental origins of OPCs, and with a different activation of NRF2-mediated anti-oxidant responses. These data indicate that, upon injury, dorsal and ventral OPC subsets show functional and molecular diversity that can make them differentially vulnerable to pathological conditions associated with DNA damage.

Analysis of Mitochondrial Function in Cell Membranes as Indicator of Tissue Vulnerability to Drugs in Humans

Drug side effects are one of the main reasons for treatment withdrawal during clinical trials. Reactive oxygen species formation is involved in many of the drug side effects, mainly by interacting with the components of the cellular respiration. Thus, the early detection of these effects in the drug discovery process is a key aspect for the optimization of pharmacological research. To this end, the superoxide formation of a series of drugs and compounds with antidepressant, antipsychotic, anticholinergic, narcotic, and analgesic properties was evaluated in isolated bovine heart membranes and on cell membrane microarrays from a collection of human tissues, together with specific inhibitors of the mitochondrial electron transport chain. Fluphenazine and PB28 promoted similar effects to those of rotenone, but with lower potency, indicating a direct action on mitochondrial complex I. Moreover, nefazodone, a drug withdrawn from the market due to its mitochondrial hepatotoxic effects, evoked the highest superoxide formation in human liver cell membranes, suggesting the potential of this technology to anticipate adverse effects in preclinical phases.

Aqueous Extract of Sea Squirt (Halocynthia roretzi) with Potent Activity against Human Cancer Cells Acts Synergistically with Doxorubicin

Marine ascidian is becoming one of the main sources of an antitumor drug that has shown high bioactivity and extensive application in cancer treatment. Halocynthia roretzi, an edible marine sea squirt, has been demonstrated to have various kinds of biological activities, such as anti-diabetic, anti-hypertension, and enhancing immunity. In this study, we reported that aqueous extracts from the edible parts of H. roretzi presented significantly inhibiting the efficiency on HepG-2 cell viability. The separate mixed compound exhibited strong effects of inhibitory proliferation and induced apoptosis via the generation of ROS along with the concurrent loss of mitochondrial membrane potential on tumor cells. Furthermore, we found that there existed a significantly synergistic effect of the ascidian-extracted compound mixture with the anti-cancer drug doxorubicin. In the presence of the extracts from H. roretzi, the dose of doxorubicin at the cellular level could be reduced by a half dose. The extracts were further divided by semipreparative-HPLC and the active ingredients were identified as a mixture of fatty amide, which was composed of hexadecanamide, stearamide, and erucamide by UHPLC-MS/MS. Our results suggest that the potential toxicity of ascidian H. roretzi in tumor cells, and the compounds extracted from H. roretzi could be potentially utilized on functional nutraceuticals or as an adjunct in combination with chemotherapy.

Terminalia ferdinandiana (Kakadu Plum)-Mediated Bio-Synthesized ZnO Nanoparticles for Enhancement of Anti-Lung Cancer and Anti-Inflammatory Activities

Terminalia ferdinandiana (Kakadu plum) is an Australian native plant that has recently gained the attention of researchers due to its highly antioxidant compounds that have substantial health benefits. To raise the value, in this study, it is used for the first time to synthesize ZnO nanoparticles for anti-lung cancer and anti-inflammatory activities. The formation of KKD-ZnO-NPs (ZnO particles obtained from Kakadu plum) were confirmed using a UV-Visible spectrophotometer. Fourier transform infrared (FTIR) spectroscopy analysis confirmed the functional groups that are responsible for the stabilization and capping of KKD-ZnO-NPs. The flower shape of the synthesized KKD-ZnO-NPs was confirmed by field emission-scanning electron microscopy (FE-SEM) and field emission-transmission electron microscopy (FE-TEM) analyses. The crystallites were highly pure and had an average size of 21.89 nm as measured by X-ray diffraction (XRD). The dynamic light scattering (DLS) revealed size range of polydisperse KKD-ZnO-NPs was 676.65 ± 47.23 nm with a PDI of 0.41 ± 0.0634. Furthermore, the potential cytotoxicity was investigated in vitro against human lung cancer cell lines (A549) and Raw 264.7 Murine macrophages cells as normal cells to ensure safety purposes using MTT assay. Thus, KKD-ZnO-NPs showed prominent cytotoxicity against human lung adenocarcinoma (A549) at 10 μg/mL and increased reactive oxygen species (ROS) production as well, which could promote toxicity to cancer cells. Moreover, upregulation of p53 and downregulation of bcl2 gene expression as apoptosis regulators were confirmed via RT-PCR. In addition, KKD-ZnO-NPs possess a similar capacity of reduction in proinflammatory-nitric oxide (NO) production when compared to the L-NMMA as inflammation’s inhibitor, indicating anti-inflammatory potential. Incorporation of Kakadu plum extract as reducing and stabilizing agents enabled the green synthesis of flower-shaped KKD-ZnO-NPs that could be an initiative development of effective cancer therapy drug.

DRG2 Depletion Promotes Endothelial Cell Senescence and Vascular Endothelial Dysfunction

Endothelial cell senescence is involved in endothelial dysfunction and vascular diseases. However, the detailed mechanisms of endothelial senescence are not fully understood. Here, we demonstrated that deficiency of developmentally regulated GTP-binding protein 2 (DRG2) induces senescence and dysfunction of endothelial cells. DRG2 knockout (KO) mice displayed reduced cerebral blood flow in the brain and lung blood vessel density. We also determined, by Matrigel plug assay, aorta ring assay, and in vitro tubule formation of primary lung endothelial cells, that deficiency in DRG2 reduced the angiogenic capability of endothelial cells. Endothelial cells from DRG2 KO mice showed a senescence phenotype with decreased cell growth and enhanced levels of p21 and phosphorylated p53, γH2AX, senescence-associated β-galactosidase (SA-β-gal) activity, and senescence-associated secretory phenotype (SASP) cytokines. DRG2 deficiency in endothelial cells upregulated arginase 2 (Arg2) and generation of reactive oxygen species. Induction of SA-β-gal activity was prevented by the antioxidant N-acetyl cysteine in endothelial cells from DRG2 KO mice. In conclusion, our results suggest that DRG2 is a key regulator of endothelial senescence, and its downregulation is probably involved in vascular dysfunction and diseases.

Cytotoxic mechanisms of doxorubicin at clinically relevant concentrations in breast cancer cells

Doxorubicin (DOX) is a chemotherapeutic agent frequently used for the treatment of a variety of tumor types, such as breast cancer. Despite the long history of DOX, the mechanistic details of its cytotoxic action remain controversial. Rather than one key mechanism of cytotoxic action, DOX is characterized by multiple mechanisms, such as (1) DNA intercalation and adduct formation, (2) topoisomerase II (TopII) poisoning, (3) the generation of free radicals and oxidative stress, and (4) membrane damage through altered sphingolipid metabolism. Many past reviews of DOX cytotoxicity are based on supraclinical concentrations, and several have addressed the concentration dependence of these mechanisms. In addition, most reviews lack a focus on the time dependence of these processes. We aim to update the concentration and time-dependent trends of DOX mechanisms at representative clinical concentrations. Furthermore, attention is placed on DOX behavior in breast cancer cells due to the frequent use of DOX to treat this disease. This review provides insight into the mechanistic pathway(s) of DOX at levels found within patients and establishes the magnitude of effect for each mechanism.

H2O2/Ca2+/Zn2+ Complex Can Be Considered a “Collaborative Sensor” of the Mitochondrial Capacity?

In order to maintain a state of well-being, the cell needs a functional control center that allows it to respond to changes in the internal and surrounding environments and, at the same time, carry out the necessary metabolic functions. In this review, we identify the mitochondrion as such an “agora”, in which three main messengers are able to collaborate and activate adaptive response mechanisms. Such response generators, which we have identified as H₂O₂, Ca²⁺, and Zn²⁺, are capable of “reading” the environment and talking to each other in cooperation with the mitochondrion. In this manner, these messengers exchange information and generate a holistic response of the whole cell, dependent on its functional state. In this review, to corroborate this claim, we analyzed the role these actors, which in the review we call “sensors”, play in the regulation of skeletal muscle contractile capacities chosen as a model of crosstalk between Ca²⁺, Zn²⁺, and H₂O₂.

The innate immune system and fever under redox control: A Narrative Review

ABSTRACT:

In living cells, redox potential is vitally important for normal physiological processes that are closely regulated by antioxidants, free amino acids and proteins that either have reactive oxygen and nitrogen species capture capability or can be compartmentalized. Although hundreds of experiments support the regulatory role of free radicals and their derivatives, several authors continue to claim that these perform only harmful and non-regulatory functions. In this paper we show that countless intracellular and extracellular signal pathways are directly or indirectly linked to regulated redox processes. We also briefly discuss how artificial oxidative stress can have important therapeutic potential and the possible negative effects of popular antioxidant supplements.

Antagonist of growth hormone-releasing hormone MIA-690 attenuates the progression and inhibits growth of colorectal cancer in mice

Colorectal cancer (CRC) is an aggressive tumor in which new treatment options deliver negative results on cure rates and long-term survival. The anticancer effects of growth hormone-releasing hormone (GHRH) antagonists have been reported in various experimental tumors, but their activity in CRC is unknown. In the present study, we demonstrated that chronic treatment with GHRH antagonist of MIAMI class, MIA-690, promoted survival and gradually blunted tumor progression in experimentally induced colitis-associated cancer in mice, paralleled by reduced inflammation in colon tissue. In particular, MIA-690 improved disease activity index score, and reduced loss of weight and mortality, by improving the survival rates, compared with vehicle-treated group. MIA-690 was also found to reduce various inflammatory and oxidative markers, such as serotonin, prostaglandin (PG)E2 and 8-iso-PGF2α levels, as well as COX-2, iNOS, TNF-α, IL-6 and NF-kB gene expression. Moreover, MIA-690 inhibited the protein expression of c-Myc, P-AKT and Bcl-2 and upregulated p53 protein expression. In conclusion, we showed that MIA-690 suppresses CRC progression and growth by reducing inflammatory and oxidative markers and modulating apoptotic and oncogenic pathways. Further investigations are required for translating these findings into the clinics.

Mangostanin, a Xanthone Derived from Garcinia mangostana Fruit, Exerts Protective and Reparative Effects on Oxidative Damage in Human Keratinocytes

The fruit of Garcinia mangostana (mangosteen) is known in ancient traditional Asian medicine for its antioxidant, anti-inflammatory, immunomodulatory and anticancer activities. These effects are mainly due to the action of polyphenols known as xanthones, which are contained in the pericarp of the fruit. In recent years, there has been a growing interest from pharmaceutical companies in formulating new topicals based on mangosteen full extracts to prevent skin aging. However, the molecules responsible for these effects and the mechanisms involved have not been investigated so far. Here, the arils and shells of Garcinia mangostana were extracted with chloroform and methanol, and the extracts were further purified to yield 12 xanthone derivatives. Their effects were evaluated using in vitro cultures of human epidermal keratinocytes. After confirming the absence of cytotoxicity, we evaluated the antioxidant potential of these compounds, identifying mangostanin as capable of both protecting and restoring oxidative damage induced by H₂O₂. We showed how mangostanin, by reducing the generation of intracellular reactive oxygen species (ROS), prevents the activation of AKT (protein kinase B), ERK (extracellular signal-regulated kinase), p53, and other cellular pathways underlying cell damage and apoptosis activation. In conclusion, our study is the first to demonstrate that mangostanin is effective in protecting the skin from the action of free radicals, thus preventing skin aging, confirming a potential toward its development in the nutraceutical and cosmeceutical fields.

Apiaceous vegetables protect against acrolein-induced pulmonary injuries through modulating hepatic detoxification and inflammation in C57BL/6 male mice

Acrolein (Acr) is a reactive aldehyde in the environment. Acr causes oxidative stress and a cascade of catalytic events and has, thereby, been associated with increased risk of pulmonary diseases. Whether apiaceous vegetables (API) consumption can prevent Acr-induced pulmonary toxicity has not yet been explored hence, we investigated the effects of API on Acr-induced pulmonary damages in C57BL/6J mice. The mice were assigned into either negative control [NEG group; American Institute of Nutrition (AIN)-93G diet only], positive control (POS group; AIN-93G+Acr) or API intervention group (API group; AIN-93G+21% API+Acr). After 1 week of dietary intervention, the POS and API mice were exposed to Acr (10 µmol/kg body weight/day) for 5 days. During the exposure period, assigned diets remained the same. Prominent indicators lung of toxicity of POS mice were found, including mucus accumulation, macrophage infiltration, and hemorrhage, all of which were ameliorated by the API. Serum and lung inflammation markers, such as a tumor necrosis factor alpha were also increased by Acr while reduced by API. In the liver, API upregulated expression of glutathione S-transferases, which enhanced the metabolism of Acr into water-soluble 3-hydroxypropyl mercapturic acid for excretion. This is consistent with observed reductions in serum Acr-protein adducts. Taken together, our results suggest that API may provide protection against Acr-induced pulmonary damages and inflammation via enhancement of the hepatic detoxification of Acr.

Engineered Aging Cardiac Tissue Chip Model for Studying Cardiovascular Disease

Due to the rapidly growing number of older people worldwide and the concomitant increase in cardiovascular complications, there is an urgent need for age-related cardiac disease modeling and drug screening platforms. In the present study, we developed a cardiac tissue chip model that incorporates hemodynamic loading and mimics essential aspects of the infarcted aging heart. We induced cellular senescence in H9c2 myoblasts using low-dose doxorubicin treatment. These senescent cells were then used to engineer cardiac tissue fibers, which were subjected to hemodynamic stresses associated with pressure-volume changes in the heart. Myocardial ischemia was modeled in the engineered cardiac tissue via hypoxic treatment. Our results clearly show that acute low-dose doxorubicin treatment-induced senescence, as evidenced by morphological and molecular markers, including enlarged and flattened nuclei, DNA damage response foci, and increased expression of cell cycle inhibitor p16INK4a, p53, and ROS. Under normal hemodynamic load, the engineered cardiac tissues demonstrated cell alignment and retained cardiac cell characteristics. Our senescent cardiac tissue model of hypoxia-induced myocardial infarction recapitulated the pathological disease hallmarks such as increased cell death and upregulated expression of ANP and BNP. In conclusion, the described methodology provides a novel approach to generate stress-induced aging cardiac cell phenotypes and engineer cardiac tissue chip models to study the cardiovascular disease pathologies associated with aging.

A new insight into cell biological and biochemical changes through aging

After several years of extensive research, the main cause of aging is yet elusive. There are some theories about aging, such as stem cell aging, senescent cells accumulation, and neuro-endocrine theories. None of them is able to explain all changes that happen in cells and body through aging. By finding out the main cause of aging, it will be much easier to control, prevent and even reverse the aging process. Our cells, regardless of their replicative capacity, get old through aging and they have almost the same epigenetic age. Different cell signaling pathways contribute to aging. The most important one is mTORC1 that becomes hyperactive in cells that undergo aging. Other significant changes with age are lysosome accumulation, impaired autophagy, and mitophagy. Immune system undergoes gradual changes through aging including a shift from lymphoid to myeloid lineage production as well as increased IL-6 and TNF-α which lead to age-related weight loss and meta-inflammation. Additionally, our endocrine system also experiences some changes that should be taken into consideration when looking for the main cause of aging in the human body. In this review, we planned to summarize some of the changes that happen in cells and the body through aging.

Combined Effects of Tanshinone IIA and an Autophagy Inhibitor on the Apoptosis of Leukemia Cells via p53, Apoptosis-Related Proteins and Oxidative Stress Pathways

Background:

Acute myeloid leukemia (AML) is a kind of hematopoietic malignancy with limited response and acquired resistance to therapy. Inducing apoptosis and inhibiting autophagy in tumor cells is a combinational strategy for the development of anticancer therapeutics. Tanshinone IIA (TAIIA) is one of the major ingredients in Salvia miltiorrhiza, which is the most prescribed herb for the treatment of AML in Taiwan. Therefore, this study aimed to delineate the anticancer effects of TAIIA and its effect when combined with an autophagy inhibitor to treat AML.

Methods:

The anticancer effects of a combination of TAIIA and the autophagy inhibitor 3-methladenine (3MA) on the human monocytic leukemia cell line THP-1 were explored. The apoptosis and cell cycle of the leukemia cells were examined by Annexin V and propidium iodide staining and analyzed by flow cytometry. The oxidative stress level was determined by a malondialdehyde (MDA) colorimetric assay, nitric oxide colorimetric assay and glutathione peroxidase (GPx) colorimetric assay. The expression of apoptosis-related proteins was determined by western blotting.

Results:

TAIIA treatment significantly induced apoptosis via increased p53, Bax/Bcl, PARP, and caspase-3 signals and oxidative stress by enhancing MDA and nitrate/nitrite production and reducing GPx activity in THP-1 cells in a dose-dependent and time-dependent manner. The combination of the autophagy inhibitor 3MA enhanced TAIIA-induced apoptosis via the p53, Bax/Bcl, PARP, caspase-3, and oxidative stress pathways in THP-1 cells.

Conclusion:

The results suggest that TAIIA and autophagy inhibitors have combined effects on the apoptosis of leukemia cells, thus representing a novel and effective combination with the potential for application as a clinical therapy for AML.

Evaluation of the Response of HOS and Saos-2 Osteosarcoma Cell Lines When Exposed to Different Sizes and Concentrations of Silver Nanoparticles

Osteosarcoma is considered to be a highly malignant tumor affecting primarily long bones. It metastasizes widely, primarily to the lungs, resulting in poor survival rates of between 19 and 30%. Standard treatment consists of surgical removal of the affected site, with neoadjuvant and adjuvant chemotherapy commonly used, with the usual side effects and complications. There is a need for new treatments in this area, and silver nanoparticles (AgNPs) are one potential avenue for exploration. AgNPs have been found to possess antitumor and cytotoxic activity in vitro, by demonstrating decreased viability of cancer cells through cell cycle arrest and subsequent apoptosis. Integral to these pathways is tumor protein p53, a tumor suppressor which plays a critical role in maintaining genome stability by regulating cell division, after DNA damage. The purpose of this study was to determine if p53 mediates any difference in the response of the osteosarcoma cells in vitro when different sizes and concentrations of AgNPs are administered. Two cell lines were studied: p53-expressing HOS cells and p53-deficient Saos-2 cells. The results of this study suggest that the presence of protein p53 significantly affects the efficacy of AgNPs on osteosarcoma cells.

Correlation between Oxidative Stress and Transforming Growth Factor-Beta in Cancers

The downregulation of reactive oxygen species (ROS) facilitates precancerous tumor development, even though increasing the level of ROS can promote metastasis. The transforming growth factor-beta (TGF-β) signaling pathway plays an anti-tumorigenic role in the initial stages of cancer development but a pro-tumorigenic role in later stages that fosters cancer metastasis. TGF-β can regulate the production of ROS unambiguously or downregulate antioxidant systems. ROS can influence TGF-β signaling by enhancing its expression and activation. Thus, TGF-β signaling and ROS might significantly coordinate cellular processes that cancer cells employ to expedite their malignancy. In cancer cells, interplay between oxidative stress and TGF-β is critical for tumorigenesis and cancer progression. Thus, both TGF-β and ROS can develop a robust relationship in cancer cells to augment their malignancy. This review focuses on the appropriate interpretation of this crosstalk between TGF-β and oxidative stress in cancer, exposing new potential approaches in cancer biology.

Reactive Oxygen Species in Anticancer Immunity: A Double-Edged Sword

Reactive oxygen species (ROS) are critical mediators in many physiological processes including innate and adaptive immunity, making the modulation of ROS level a powerful strategy to augment anticancer immunity. However, current evidences suggest the necessity of a deeper understanding of their multiple roles, which may vary with their concentration, location and the immune microenvironment they are in. Here, we have reviewed the reported effects of ROS on macrophage polarization, immune checkpoint blocking (ICB) therapy, T cell activation and expansion, as well as the induction of immunogenic cell death. A majority of reports are indicating detrimental effects of ROS, but it is unadvisable to simply scavenge them because of their pleiotropic effects in most occasions (except in T cell activation and expansion where ROS are generally undesirable). Therefore, clinical success will need a clearer illustration of their multi-faced functions, as well as more advanced technologies to tune ROS level with high spatiotemporal control and species-specificity. With such progresses, the efficacy of current immunotherapies will be greatly improved by combining with ROS-targeted therapies.

Adaptive homeostasis and the p53 isoform network

All living organisms have developed processes to sense and address environmental changes to maintain a stable internal state (homeostasis). When activated, the p53 tumour suppressor maintains cell and organ integrity and functions in response to homeostasis disruptors (stresses) such as infection, metabolic alterations and cellular damage. Thus, p53 plays a fundamental physiological role in maintaining organismal homeostasis. The TP53 gene encodes a network of proteins (p53 isoforms) with similar and distinct biochemical functions. The p53 network carries out multiple biological activities enabling cooperation between individual cells required for long‐term survival of multicellular organisms (animals) in response to an ever‐changing environment caused by mutation, infection, metabolic alteration or damage. In this review, we suggest that the p53 network has evolved as an adaptive response to pathogen infections and other environmental selection pressures.

Caulerpin Mitigates Helicobacter pylori-Induced Inflammation via Formyl Peptide Receptors

The identification of novel strategies to control Helicobacter pylori (Hp)-associated chronic inflammation is, at present, a considerable challenge. Here, we attempt to combat this issue by modulating the innate immune response, targeting formyl peptide receptors (FPRs), G-protein coupled receptors that play key roles in both the regulation and the resolution of the innate inflammatory response. Specifically, we investigated, in vitro, whether Caulerpin—a bis-indole alkaloid isolated from algae of the genus Caulerpa—could act as a molecular antagonist scaffold of FPRs. We showed that Caulerpin significantly reduces the immune response against Hp culture filtrate, by reverting the FPR2-related signaling cascade and thus counteracting the inflammatory reaction triggered by Hp peptide Hp(2–20). Our study suggests Caulerpin to be a promising therapeutic or adjuvant agent for the attenuation of inflammation triggered by Hp infection, as well as its related adverse clinical outcomes.

Chemopreventive potential of plant-derived epigenetic inhibitors silibinin and quercetin: an involvement of apoptotic signaling cascade modulation

Background

Epigenetic deregulation of the cellular apoptotic mechanism is the common hallmark of cancer. Silibinin (SBN) and quercetin (QCT) are two bioflavonoids well known for their epigenetic inhibition property. The objective of the present study was to explore the preventive anti-cancer efficacy of the SBN and QCT in both in vitro as well as in vivo tumor xenograft model through regulating cellular apoptotic signaling pathway.

Results

SBN and QCT inhibited the growth of A549 and MDA-MB-468 cancer cells in the concentration dependent manner. The treatment caused significant (p < 0.05) reduction of the size and the number of colonies formed by the cancer cells. In vitro apoptosis assay using the fluorescence microscopy revealed that the treatment noticeably increased the percentage of apoptotic cells as compared to the untreated control. Dosing with SBN (200mg/kg), QCT (100mg/kg) alone and in combination was initiated in 3-week-old C57BL6 mice. Interestingly, the treatment prevented tumor progression significantly (p < 0.05) in adult mice without causing any toxicity. Furthermore, SBN and QCT triggered apoptosis via modulating p53 and Bcl2 gene expression and the SOD enzyme activity.

Conclusion

Daily oral intake of SBN and QCT alone and in combination from the very early stage of life might prevent tumor growth in adult mice through activating cellular apoptotic signaling cascade.

Beneficial Oxidative Stress-Related trans-Resveratrol Effects in the Treatment and Prevention of Breast Cancer

Resveratrol is one of the most investigated polyphenols for its multiple biological activities and many beneficial effects. These are mainly related to its ability to scavenge free radicals and reduce oxidative stress. Resveratrol has also been shown to have the ability to stimulate the production of antioxidant enzymes, which interact with numerous signaling pathways involved in tumor development, and to possess side effects associated with the use of chemotherapy drugs. In this review article we summarized the main discoveries about the impact resveratrol can have in helping to prevent, as well as adjuvant treating, breast cancer. A brief overview of the primary sources of resveratrol as well as some approaches for improving its bioavailability have been also discussed.

The effect of miR-1338 on the immunomodulatory activity of ophiopogon polysaccharide liposome

This study is to investigate the effect of microRNA-1338 (miR-1338) on the activity of Kupffer cells (KCs) and its mechanism regulated by ophiopogon polysaccharide liposome (OPL). KCs was treated with different OPL after transfected with miR-1338 mimic and miR-1338 inhibitor. The secretion of NO and iNOS, the expression of catalase (CAT) and peroxidase (POD), the phagocytic activity, the expression of CD14 and MHC II, the apoptosis and the secretion of ROS were measured. In addition, the expressions of key signal factors TLR4, IKKβ, MyD88 and NF-κB in NF-κB signaling pathway were measured by real-time PCR and Western blot (WB). The results showed that OPL could promote the secretion of iNOS, the expression of POD, the phagocytosis, the mRNA expression of TLR4, MyD88, IKKβ and NF-κB, the protein expression of TLR4 and NF-κB, and inhibit the cell apoptosis and ROS secretion after transfected with miR-1338 mimic. After transfected with miR-1338 inhibitor, OPL could promote the secretion of NO and iNOS, the expression of POD, cell migration, phagocytosis, and inhibit cell apoptosis. Meanwhile, the mRNA expression of TLR4, MyD88, IKKβ and NF-κB and the protein expression of TLR4, MyD88 and NF-κB were promoted. These results suggested that OPL could activate TLR4-NF-κB signaling pathway and thereby improve the activity of KCs by regulating miR-1338.

Reactive oxygen species: Role in carcinogenesis, cancer cell signaling and tumor progression

Cancer is one of the major causes of death in the world and its global burden is expected to continue increasing. In several types of cancers, reactive oxygen species (ROS) have been extensively linked to carcinogenesis and cancer progression. However, studies have reported conflicting evidence regarding the role of ROS in cancer, mostly dependent on the cancer type or the step of the tumorigenic process. We review recent studies describing diverse aspects of the interplay of ROS with cancer in the different stages of cancer progression, with a special focus on their role in carcinogenesis, their importance for cancer cell signaling and their relationship to the most prevalent cancer risk factors.

Salicylic acid: A key regulator of redox signalling and plant immunity

In plants, the reactive oxygen species (ROS) formed during normal conditions are essential in regulating several processes, like stomatal physiology, pathogen immunity and developmental signaling. However, biotic and abiotic stresses can cause ROS over-accumulation leading to oxidative stress. Therefore, a suitable equilibrium is vital for redox homeostasis in plants, and there have been major advances in this research arena. Salicylic acid (SA) is known as a chief regulator of ROS; however, the underlying mechanisms remain largely unexplored. SA plays an important role in establishing the hypersensitive response (HR) and systemic acquired resistance (SAR). This is underpinned by a robust and complex network of SA with Non-Expressor of Pathogenesis Related protein-1 (NPR1), ROS, calcium ions (Ca²⁺), nitric oxide (NO) and mitogen-activated protein kinase (MAPK) cascades. In this review, we summarize the recent advances in the regulation of ROS and antioxidant defense system signalling by SA at the physiological and molecular levels. Understanding the molecular mechanisms of how SA controls redox homeostasis would provide a fundamental framework to develop approaches that will improve plant growth and fitness, in order to meet the increasing global demand for food and bioenergy.

Cylindrospermopsin impairs vascular smooth muscle cells by P53-mediated apoptosis due to ROS overproduction

Cylindrospermopsin (CYN) is a toxic secondary metabolite from cyanobacteria that can cause cardiovascular disease. However, the study of CYN-induced cardiovascular toxicity in vitro is very limited and the mechanism is remain to be clarified. Vascular smooth muscle cells (VMSCs) have an important function in maintaining the structural and functional integrity of the aortic wall, and are an important in vitro model for cardiovascular research. Thus, the effects of CYN exposure (2, 20, 200, and 2000 nM) on VMSCs were analyzed. In vitro study, results showed that CYN exposure decreased VMSCs viability, inhibited VMSCs migration, induced DNA damage, destroyed cytoskeleton, changed cell morphology, promoted VMSCs apoptosis, and increased intracellular reactive oxygen species (ROS) levels. In addition, CYN could induce the activities of SOD, CAT and GPX, and promote the expressions of SOD1, CAT, GPx1, p53 and Bax genes and inhibit the expression of Bcl-2 gene, leading to a higher ratio of Bax/Bcl-2. Taken together, CYN may induce ROS overproduction, leading to increased p53 expression and ultimately promoting VSMC apoptosis. Therefore, the present study demonstrates that CYN could impair VMSCs, leading to vascular developmental defects and angiocardiopathy.

Anti-Oxidative, Anti-Inflammatory and Anti-Apoptotic Effects of Flavonols: Targeting Nrf2, NF-κB and p53 Pathways in Neurodegeneration

Neurodegenerative diseases are one of the leading causes of disability and death worldwide. Intracellular transduction pathways that end in the activation of specific transcription factors are highly implicated in the onset and progression of pathological changes related to neurodegeneration, of which those related to oxidative stress (OS) and neuroinflammation are particularly important. Here, we provide a brief overview of the key concepts related to OS- and neuroinflammation-mediated neuropathological changes in neurodegeneration, together with the role of transcription factors nuclear factor erythroid 2-related factor 2 (Nrf2) and nuclear factor-κB (NF-κB). This review is focused on the transcription factor p53 that coordinates the cellular response to diverse genotoxic stimuli, determining neuronal death or survival. As current pharmacological options in the treatment of neurodegenerative disease are only symptomatic, many research efforts are aimed at uncovering efficient disease-modifying agents. Natural polyphenolic compounds demonstrate powerful anti-oxidative, anti-inflammatory and anti-apoptotic effects, partially acting as modulators of signaling pathways. Herein, we review the current understanding of the therapeutic potential and limitations of flavonols in neuroprotection, with emphasis on their anti-oxidative, anti-inflammatory and anti-apoptotic effects along the Nrf2, NF-κB and p53 pathways. A better understanding of cellular and molecular mechanisms of their action may pave the way toward new treatments.

Neuroinflammatory Triangle Presenting Novel Pharmacological Targets for Ischemic Brain Injury

Ischemic stroke is one of the leading causes of morbidity and mortality globally. Hundreds of clinical trials have proven ineffective in bringing forth a definitive and effective treatment for ischemic stroke, except a myopic class of thrombolytic drugs. That, too, has little to do with treating long-term post-stroke disabilities. These studies proposed diverse options to treat stroke, ranging from neurotropic interpolation to venting antioxidant activity, from blocking specific receptors to obstructing functional capacity of ion channels, and more recently the utilization of neuroprotective substances. However, state of the art knowledge suggests that more pragmatic focus in finding effective therapeutic remedy for stroke might be targeting intricate intracellular signaling pathways of the 'neuroinflammatory triangle': ROS burst, inflammatory cytokines, and BBB disruption. Experimental evidence reviewed here supports the notion that allowing neuroprotective mechanisms to advance, while limiting neuroinflammatory cascades, will help confine post-stroke damage and disabilities.

Molecular mechanism of anti-adipogenic effect of vitexin in differentiating hMSCs

In this study, we evaluated a detailed molecular mechanism of anti-adipogenic activity of vitexin, apigenin flavone glucoside, present in germinated fenugreek seeds, in differentiating human mesenchymal stem cells (hMSCs). The lipid content of differentiated adipocytes was estimated by ORO staining. Effect on mitotic clonal expansion was checked by cell cycle analysis. Expression of early and terminal adipocyte differentiation markers, anti- and pro-adipogenic transcription factors and signalling intermediates regulating them was evaluated at RNA and protein level. We found vitexin to be non-cytotoxic up to 20 μM at which intracellular lipid accumulation was significantly decreased. Cell cycle analysis suggested that vitexin does not affect mitotic clonal expansion. Expression of early and late differentiation markers, such as CEBPα, CEBPβ, PPARγ, FABP4, perilipin, adiponectin and Glut4 was significantly reduced in the presence of vitexin. Expression of KLF4 and KLF15, positive regulators of PPARγ, was decreased, whereas that of negative regulators, namely KLF2, GATA2, miR20a, miR27a, miR27b, miR128, miR130a, miR130b, miR182 and miR548 increased with vitexin treatment. This effect was mediated by the activation of the AMP-activated protein kinase (AMPK) pathway via the activation of LepR and additionally by inhibiting ROS. Thus, our results showed that vitexin regulates the expression of PPARγ and inhibits adipogenesis of hMSCs at an early stage of differentiation.