Link between PI3K/AKT/PTEN Pathway and NOX Proteinin Diseases

Lysosomal cation channel TRPML1 suppression sensitizes acute myeloid leukemia cells to chemotherapeutics by inhibiting autophagy

Despite the implementation of novel therapeutic regimens and extensive research efforts, chemoresistance remains a formidable challenge in the treatment of acute myeloid leukemia (AML). Notably, the involvement of lysosomes in chemoresistance has sparked interest in developing lysosome-targeted therapies to sensitize tumor cells to currently approved chemotherapy or as innovative pharmacological approaches. Moreover, as ion channels on the lysosomal membrane are critical regulators of lysosomal function, they present potential as novel targets for enhancing chemosensitivity. Here, we discovered that the expression of a lysosomal cation channel, namely transient receptor potential mucolipin 1 (TRPML1), was elevated in AML cells. Inhibiting TRPML1 individually does not impact the proliferation and apoptosis of AML cells. Importantly, inhibition of TRPML1 demonstrated the potential to modulate the sensitivity of AML cells to chemotherapeutic agents. Exploration of the underlying mechanisms revealed that suppression of TRPML1 impaired autophagy while concurrently increasing the production of reactive oxygen species (ROS) and ROS-mediated lipid peroxidation (Lipid-ROS) in AML cells. Finally, the knockdown of TRPML1 significantly reduced OCI-AML3 tumor growth following chemotherapy in a mouse model of human leukemia. In summary, targeting TRPML1 represents a promising approach for combination therapy aimed at enhancing chemosensitivity in treating AML.

Fenofibrate Ameliorates Retinal Pigment Epithelium Injury Induced by Excessive Fat Through Upregulation of PI3K/AKT Signaling

Purpose

This study aimed to determine the effect and its mechanism of fenofibrate on retinal pigment epithelium (RPE) injury induced by excessive fat in vitro and in vivo.

Methods

ARPE-19 cells were co-incubated with palmitic acid (PA) and fenofibric acid (the active form of fenofibrate after metabolism in vivo) and mice fed with high-fat diet (HFD) were supplemented with fenofibrate. The following methods were used: Western blot and immunofluorescent staining to determine expressions of reactive oxygen species (ROS)-associated factors and proinflammatory cytokines; electroretinogram (ERG) c-wave to evaluate RPE function; TUNEL staining to detect the apoptotic cell in RPE tissue. Additionally, ARPE19 cells were treated with PI3K/AKT inhibitor or agonist to investigate the mechanism of fenofibric acid inhibiting PA-induced RPE damage.

Results

We found that the application of PA inhibited RPE cell viability in a dose-dependent manner, and increased the levels of NAPDH oxidase 4 (NOX4), 3-nitrotyrosin (3-NT), intracellular adhesion molecule-1(ICAM1), tumor necrosis factor alpha (TNFα) and vascular endothelial growth factor (VEGF) at 400μM. The application of fenofibric acid resulted in the inhibition of NOX4, 3-NT, TNFα, ICAM1 and VEGF expression in ARPE-19 cells treated with PA. Moreover, wortmannin, as a selective inhibitor of PI3K/AKT pathway, abolished the effects of fenofibrate on the oxidative stress and inflammation in ARPE-19 cells. In addition, 740Y-P, a selective agonist of PI3K/AKT pathway, enhanced the protective action of fenofibrate. Meanwhile, in vivo dosing of fenofibrate ameliorated the downregulated amplitudes of ERG c-wave in HFD-fed mice and suppressed the HFD-induced oxidative injury and inflammatory response in RPE tissues.

Conclusion

Our results suggested that fenofibrate ameliorated RPE cell damage induced by excessive fat in vitro and in vivo, in part, through activation of the PI3K/AKT signaling pathway.

Radical oxygen species: an important breakthrough point for botanical drugs to regulate oxidative stress and treat the disorder of glycolipid metabolism

Background: The incidence of glycolipid metabolic diseases is extremely high worldwide, which greatly hinders people's life expectancy and patients' quality of life. Oxidative stress (OS) aggravates the development of diseases in glycolipid metabolism. Radical oxygen species (ROS) is a key factor in the signal transduction of OS, which can regulate cell apoptosis and contribute to inflammation. Currently, chemotherapies are the main method to treat disorders of glycolipid metabolism, but this can lead to drug resistance and damage to normal organs. Botanical drugs are an important source of new drugs. They are widely found in nature with availability, high practicality, and low cost. There is increasing evidence that herbal medicine has definite therapeutic effects on glycolipid metabolic diseases. Objective: This study aims to provide a valuable method for the treatment of glycolipid metabolic diseases with botanical drugs from the perspective of ROS regulation by botanical drugs and to further promote the development of effective drugs for the clinical treatment of glycolipid metabolic diseases. Methods: Using herb*, plant medicine, Chinese herbal medicine, phytochemicals, natural medicine, phytomedicine, plant extract, botanical drug, ROS, oxygen free radicals, oxygen radical, oxidizing agent, glucose and lipid metabolism, saccharometabolism, glycometabolism, lipid metabolism, blood glucose, lipoprotein, triglyceride, fatty liver, atherosclerosis, obesity, diabetes, dysglycemia, NAFLD, and DM as keywords or subject terms, relevant literature was retrieved from Web of Science and PubMed databases from 2013 to 2022 and was summarized. Results: Botanical drugs can regulate ROS by regulating mitochondrial function, endoplasmic reticulum, phosphatidylinositol 3 kinase (PI3K)/protein kinase B (AKT), erythroid 2-related factor 2 (Nrf-2), nuclear factor κB (NF-κB), and other signaling pathways to improve OS and treat glucolipid metabolic diseases. Conclusion: The regulation of ROS by botanical drugs is multi-mechanism and multifaceted. Both cell studies and animal experiments have demonstrated the effectiveness of botanical drugs in the treatment of glycolipid metabolic diseases by regulating ROS. However, studies on safety need to be further improved, and more studies are needed to support the clinical application of botanical drugs.

Reactive Oxygen Species and Metabolism in Leukemia: A Dangerous Liaison

Reactive oxygen species (ROS), previously considered toxic by-products of aerobic metabolism, are increasingly recognized as regulators of cellular signaling. Keeping ROS levels low is essential to safeguard the self-renewal capacity of hematopoietic stem cells (HSC). HSC reside in a hypoxic environment and have been shown to be highly dependent on the glycolytic pathway to meet their energy requirements. However, when the differentiation machinery is activated, there is an essential enhancement of ROS together with a metabolic shift toward oxidative metabolism. Initiating and sustaining leukemia depend on the activity of leukemic stem cells (LSC). LSC also show low ROS levels, but unlike HSC, LSC rely on oxygen to meet their metabolic energetic requirements through mitochondrial respiration. In contrast, leukemic blasts show high ROS levels and great metabolic plasticity, both of which seem to sustain their invasiveness. Oxidative stress and metabolism rewiring are recognized as hallmarks of cancer that are intimately intermingled. Here we present a detailed overview of these two features, sustained at different levels, that support a two-way relationship in leukemia. Modifying ROS levels and targeting metabolism are interesting therapeutic approaches. Therefore, we provide the most recent evidence on the modulation of oxidative stress and metabolism as a suitable anti-leukemic approach.

Citrus unshiu Peel Attenuates Dextran Sulfate Sodium-Induced Ulcerative Colitis in Mice due to Modulation of the PI3K/Akt Signaling Pathway and MAPK and NF-κB

Aim

Citrus unshiu peel has been used to treat various diseases in traditional East Asian medicine including Korea, and many studies have been reported regarding inflammatory diseases including ulcerative colitis (UC). However, the underlying mechanism by which Citrus unshiu peel modulates inflammation in UC remains unclear. Therefore, this study aimed to evaluate the therapeutic effect and underlying mechanism of Citrus unshiu peel water extract (CUP) for UC.

Methods

The experiment for UC was conducted with 8-week-old male Balb/c mice. After 1 week of adaptation, acute colitis was induced in all groups except the normal group by 5% DSS dissolved in drinking water for 1 week. Balb/c mice were divided into 5 groups (n = 8/group): control group (Control), distilled water-treated group (DSS), 100 mg/kg sulfasalazine-treated group (SASP), 100 mg/kg CUP-treated group (CUPL), and 200 mg/kg CUP-treated group (CUPH). The efficacy of CUP on UC was evaluated by biochemical analyses such as ROS and MPO in serum and MDA in tissues, and expression of proteins related to inflammation and apoptosis was evaluated through Western blot.

Results

As a result of confirming the macroscopic changes and H&E staining in colon tissues to confirm the preventive and therapeutic effects of CU, decrease in colon length and inflammatory lesions were inhibited in the CUP-treated group compared to the DSS group. In addition, as a result of serum ROS and tissue MDA analysis and oxidative stress-related protein analysis, it was significantly decreased in the CUP-administered group compared to the control group. In addition, treatment with CUP not only inactivated MAPK, p-IκBα, and NF-κBp65 by blocking the PI3K/Akt pathway but also significantly reduced the expression of inflammatory cytokines.

Conclusion

These results show that CUP not only suppresses oxidative stress in UC but also regulates inflammation-related proteins and apoptotic proteins by regulating the PI3K/Akt signaling pathway, suggesting that it has the potential as a material for developing new natural therapeutic agents for UC.

Overexpression of Renin-B Induces Warburg-like Effects That Are Associated with Increased AKT/mTOR Signaling

The classical secretory renin-a is known to be involved in angiotensin generation, thereby regulating not only blood pressure, but also promoting oxidative stress as well as apoptotic and necrotic cell death. In contrast, another cytosolic renin isoform named renin-b has been described, exerting protective effects under ischemia-related conditions in H9c2 cardiomyoblasts. Using microarray-based transcriptome analyses, we aimed to identify the signaling pathways involved in mediating cardioprotection in H9c2 cells overexpressing renin-b. By transcriptome profiling, we identified increased gene expression of several genes encoding glycolytic enzymes and glucose transporters, while the transcript levels of TCA-cycle enzymes were decreased. Complementing data from metabolic analyses revealed enhanced glucose consumption and lactate accumulation due to renin-b overexpression. Renin-b overexpression further stimulated AKT/mTOR signaling, where numerous genes involved in this pathway showed altered transcript levels. For AKT, we also detected enhanced phosphorylation levels by means of Western blotting, suggesting an activation of this kinase. Moreover, analysis of the ROS levels identified an increase in ROS accumulation in renin-b-overexpressing cells. Altogether, our data demonstrate that renin-b overexpression induces the metabolic remodeling of H9c2 cells similar to that seen under oxygen deprivation. This metabolic phenotype exerting so-called aerobic glycolysis is also known as the Warburg effect.

Do Naturally Occurring Antioxidants Protect Against Neurodegeneration of the Dopaminergic System? A Systematic Revision in Animal Models of Parkinson's Disease

Parkinson's disease (PD) is the second most common neurodegenerative disease and is characterized by a significant decrease in dopamine levels, caused by progressive degeneration of the dopaminergic neurons in the nigrostriatal pathway. Multiple mechanisms have been implicated in its pathogenesis, including oxidative stress, neuroinflammation, protein aggregation, mitochondrial dysfunction, insufficient support for neurotrophic factors and cell apoptosis. The absence of treatments capable of slowing or stopping the progression of PD has increased the interest in the natural antioxidant substances present in the diet, since they have multiple beneficial properties and it is possible that they can influence the mechanisms responsible for the dysfunction and death of dopaminergic neurons. Thus, the purpose of this systematic review is to analyze the results obtained in a set of studies carried out in the last years, which describe the neuroprotective, antioxidant and regenerative functions of some naturally occurring antioxidants in experimental models of PD. The results show that the exogenous no enzymatic antioxidants can significantly modify the biochemical and behavioral mechanisms that contribute to the pathophysiology of Parkinsonism in experimental animals. Therefore, it is possible that they may contribute to effective neuroprotection by providing a significant improvement in neuropathological markers. In conclusion, the results of this review suggest that exogenous antioxidants can be promising therapeutic candidates for the prevention and treatment of PD.

Investigate the genetic mechanisms of diabetic kidney disease complicated with inflammatory bowel disease through data mining and bioinformatic analysis

BACKGROUND

Patients with diabetic kidney disease (DKD) often have gastrointestinal dysfunction such as inflammatory bowel disease (IBD). This study aims to investigate the genetic mechanism leading to IBD in DKD patients through data mining and bioinformatics analysis.

METHODS

The disease-related genes of DKD and IBD were searched from the five databases of OMIM, GeneCards, PharmGkb, TTD, and DrugBank, and the intersection part of the two diseases were taken to obtain the risk genes of DKD complicated with IBD. A protein-protein interaction (PPI) network analysis was performed on risk genes, and three topological parameters of degree, betweenness, and closeness of nodes in the network were used to identify key risk genes. Finally, Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were performed on the risk genes to explore the related mechanism of DKD merging IBD.

RESULTS

This study identified 495 risk genes for DKD complicated with IBD. After constructing a protein-protein interaction network and screening for three times, six key risk genes were obtained, including matrix metalloproteinase 2 (MMP2), hepatocyte growth factor (HGF), fibroblast growth factor 2 (FGF2), interleukin (IL)-18, IL-13, and C-C motif chemokine ligand 5 (CCL5). Based on GO enrichment analysis, we found that DKD genes complicated with IBD were associated with 3,646 biological processes such as inflammatory response regulation, 121 cellular components such as cytoplasmic vesicles, and 276 molecular functions such as G-protein-coupled receptor binding. Based on KEGG enrichment analysis, we found that the risk genes of DKD combined with IBD were associated with 181 pathways, such as the PI3K-Akt signaling pathway, advanced glycation end product-receptor for AGE (AGE-RAGE) signaling pathway and hypoxia-inducible factor (HIF)-1 signaling pathway.

CONCLUSION

There is a genetic mechanism for the complication of IBD in patients with CKD. Oxidative stress, chronic inflammatory response, and immune dysfunction were possible mechanisms for DKD complicated with IBD.

Current evidence to support the therapeutic potential of flavonoids in oxidative stress-related dermatoses

BACKGROUND

Skin, as a crucial external defense organ, is more vulnerable to oxidative stress (OS) insult, reactive oxygen species (ROS)-mediated OS in particular. OS results from a redox imbalance caused by various extrinsic stimuli and occurs once the oxidants production overwhelming the antioxidants capacity, through mediating in DNA damage, lipid peroxidation (LPO), protein oxidation and a serial of signaling pathways activation/inactivation, thereby offering favorable conditions for the occurrence and development of numerous diseases especially some dermatoses, e.g. psoriasis, vitiligo, skin photodamage, skin cancer, systemic sclerosis (SSc), chloasma, atopic dermatitis (AD), pemphigus, etc. Targeting OS molecular mechanism, a variety of anti-OS agents emerge, in which flavonoids, natural plant extracts, stand out.

OBJECTIVES

To discuss the possible mechanisms of OS mediating in dermatoses and summarize the properties of flavonoids as well as their applications in OS-related skin disorders.

METHODS

Published papers on flavonoids and OS-related skin diseases were collected and reviewed via database searching on PubMed, MEDLINE and Embase, etc.

RESULTS

It has been confirmed that flavonoids, belonging to polyphenols, are a class of plant secondary metabolites widely distributed in various plants and possess diverse bioactivities especially their potent antioxidant capacity. Moreover, flavonoids benefit to suppress OS via eliminating free radicals and mediating the corresponding signals, further excellently working in the prevention and management of OS-related skin diseases.

CONCLUSION

Flavonoids have the potential therapeutic effects on oxidative stress-related dermatoses. However, more studies on specific mechanism as well as the dosage of flavonoids are needed in future.

The Promoting Effect of Traumatic Brain Injury on the Incidence and Progression of Glioma: A Review of Clinical and Experimental Research

The role of traumatic brain injury in the development of glioma is highly controversial since first presented. This is not unexpected because traumatic brain injuries are overwhelmingly more common than glioma. However, the causes of post-traumatic glioma have been long discussed and still warrant further research. In this review, we have presented an overview of previous cohort studies and case–control studies. We have summarized the roles of microglial cells, macrophages, astrocytes, and stem cells in post-traumatic glioma formation and development, and reviewed various carcinogenic factors involved during traumatic brain injury, especially those reported in experimental studies indicating a relationship with glioma progression. Besides, traumatic brain injury and glioma share several common pathways, including inflammation and oxidative stress; however, the exact mechanism underlying this co-occurrence is yet to be discovered. In this review, we have summarized current epidemiological studies, clinical reports, pathophysiological research, as well as investigations evaluating the probable causes of co-occurrence and treatment possibilities. More efforts should be directed toward elucidating the relationship between traumatic brain injury and glioma, which could likely lead to promising pharmacological interventions towards designing therapeutic strategies.

Oxypaeoniflorin Prevents Acute Lung Injury Induced by Lipopolysaccharide through the PTEN/AKT Pathway in a Sirt1-Dependent Manner

Acute lung injury (ALI) is featured by pulmonary edema, alveolar barrier injury, inflammatory response, and oxidative stress. The activation of Sirt1 could relieve lipopolysaccharide- (LPS-) induced murine ALI by maintaining pulmonary epithelial barrier function. Oxypaeoniflorin (Oxy) serves as a major component of Paeonia lactiflora Pall., exerting cardioprotection by activating Sirt1. However, the role of Oxy in ALI induced by LPS remains unclear. The aim of the present study is to illustrate the modulatory effects and molecular mechanisms by which Oxy operates in ALI induced by LPS. The intraperitoneal injection of LPS was performed to establish the murine ALI model while LPS-treated alveolar epithelial cells were used to mimic the in vitro ALI model. Levels of lung injury, oxidative stress, and inflammatory response were detected to observe the potential effects of Oxy on ALI. Oxy treatment mitigated lung edema, inflammatory response, and oxidative stress in mouse response to LPS, apart from improving 7-day survival. Meanwhile, Oxy also increased the expression and activity of Sirt1. Intriguingly, Sirt1 deficiency or inhibition counteracted the protective effects of Oxy treatment in LPS-treated mice or LPS-treated alveolar epithelial cells by regulating the PTEN/AKT signaling pathway. These results demonstrated that Oxy could combat ALI in vivo and in vitro through inhibiting inflammatory response and oxidative stress in a Sirt1-dependent manner. Oxy owns the potential to be a promising candidate against ALI.

Dual Role of Reactive Oxygen Species and their Application in Cancer Therapy

Reactive oxygen species (ROS) play a dual role in the initiation, development, suppression, and treatment of cancer. Excess ROS can induce nuclear DNA, leading to cancer initiation. Not only that, but ROS also inhibit T cells and natural killer cells and promote the recruitment and M2 polarization of macrophages; consequently, cancer cells escape immune surveillance and immune defense. Furthermore, ROS promote tumor invasion and metastasis by triggering epithelial-mesenchymal transition in tumor cells. Interestingly, massive accumulation of ROS inhibits tumor growth in two ways: (1) by blocking cancer cell proliferation by suppressing the proliferation signaling pathway, cell cycle, and the biosynthesis of nucleotides and ATP and (2) by inducing cancer cell death via activating endoplasmic reticulum stress-, mitochondrial-, and P53- apoptotic pathways and the ferroptosis pathway. Unfortunately, cancer cells can adapt to ROS via a self-adaption system. This review highlighted the bidirectional regulation of ROS in cancer. The study further discussed the application of massively accumulated ROS in cancer treatment. Of note, the dual role of ROS in cancer and the self-adaptive ability of cancer cells should be taken into consideration for cancer prevention.

Neuroinflammation: The next target of exosomal microRNAs derived from mesenchymal stem cells in the context of neurological disorders

Among different types of mechanisms involved in neurological disorders, neuroinflammation links initial insults to secondary injuries and triggers some chronic outcomes, for example, neurodegenerative disorders. Thus, anti-inflammatory substances can be targeted as a novel therapeutic option for translational and clinical research to improve brain disease outcomes. In this review, we propose to introduce a new insight into the anti-inflammatory effects of mesenchymal stem cells (MSCs) as the most frequent source for stem cell therapy in neurological diseases. Our insight incorporates a bystander effect of these stem cells in modulating inflammation and microglia/macrophage polarization through exosomes. Exosomes are nano-sized membrane vesicles that carry cell-specific constituents, including protein, lipid, DNA, and RNA. microRNAs (miRNAs) have recently been detected in exosomes that can be taken up by other cells and affect the behavior of recipient cells. In this article, we outline and highlight the potential use of exosomal miRNAs derived from MSCs for inflammatory pathways in the context of neurological disorders. Furthermore, we suggest that focusing on exosomal miRNAs derived from MSCs in the course of neuroinflammatory pathways in the future could reveal their functions for diverse neurological diseases, including brain injuries and neurodegenerative diseases. It is hoped that this study will contribute to a deep understanding of stem cell bystander effects through exosomal miRNAs.

C-C motif ligand 8 promotes atherosclerosis via NADPH oxidase 2/reactive oxygen species-induced endothelial permeability increase

Chemokines have been reported to play important roles in atherosclerotic development. Recently, we found C-C motif ligand 8 (CCL8), a rarely studied chemokine in atherosclerosis, was highly expressed in the endothelium of advanced human carotid plaques. We hypothesized whether CCL8 promotes atherosclerosis through endothelial dysfunction. Apolipoprotein E-deficient mice under the Western diet were used to construct atherosclerosis models. Adeno-associated viruses (AAV) with CCL8 and the CCL8-antibody were injected into mice respectively to conduct CCL8 overexpression and suppression. The results showed that atherosclerotic lesions were significantly increased in the AAV-CCL8 group, while, lesions in the aortic sinus were reduced in the CCL8-antibody group. With CCL8 treatment (200 ng/ml, 24 h) in vitro, the permeability of human aortic endothelial cells (HAECs) increased and the expression of junctional proteins Zonula occluden-1, and Vascular endothelial cadherin were decreased. This effect was dependent on reactive oxygen species (ROS) generation, which could be blocked by l-Ascorbic acid and Apocynin. Results showed that NADPH oxidase 2 (NOX2) expression also increased with CCL8 stimulation and the ROS, and permeability increase of HAECs could be inhibited when NOX2 interfered with the specific siRNA. Additionally, we further found ERK1/2, PI3K-AKT, and NF-κB pathways were involved in the activation of CCL8. Our results indicated that CCL8 might also play important roles in atherosclerosis and this effect, at least in part, was caused by NOX2/ROS-induced endothelial permeability increase. This study might contribute to a deeper understanding of the connection between chemokines and atherosclerosis.

Peroxisome Proliferator-Activated Receptor-δ Deficiency in Microglia Results in Exacerbated Axonal Injury and Tissue Loss in Experimental Autoimmune Encephalomyelitis

Peroxisome proliferator-activated receptor (PPAR)-δ is a nuclear receptor that functions to maintain metabolic homeostasis, regulate cell growth, and limit the development of excessive inflammation during immune responses. Previously, we reported that PPAR-δ-deficient mice develop a more severe clinical course of experimental autoimmune encephalomyelitis (EAE); however, it was difficult to delineate the role that microglia played in this disease phenotype since PPAR-δ-deficient mice exhibited a number of immune defects that enhanced CNS inflammation upstream of microglia activation. Here, we specifically investigated the role of PPAR-δ in microglia during EAE by using mice where excision of a floxed Ppard allele was driven by expression of a tamoxifen (TAM)-inducible CX3C chemokine receptor 1 promoter-Cre recombinase transgene (Cx3cr1^CreERT2: Ppard^fl/fl). We observed that by 30 days of TAM treatment, Cx3cr1^CreERT2: Ppard^fl/fl mice exhibited Cre-mediated deletion primarily in microglia and this was accompanied by efficient knockdown of Ppard expression in these cells. Upon induction of EAE, TAM-treated Cx3cr1^CreERT2: Ppard^fl/fl mice presented with an exacerbated course of disease compared to TAM-treated Ppard^fl/fl controls. Histopathological and magnetic resonance (MR) studies on the spinal cord and brains of EAE mice revealed increased Iba-1 immunoreactivity, axonal injury and CNS tissue loss in the TAM-treated Cx3cr1^CreERT2: Ppard^fl/fl group compared to controls. In early EAE, a time when clinical scores and the infiltration of CD45⁺ leukocytes was equivalent between Cx3cr1^CreERT2: Ppard^fl/fl and Ppard^fl/fl mice, Ppard-deficient microglia exhibited a more reactive phenotype as evidenced by a shorter maximum process length and lower expression of genes associated with a homeostatic microglia gene signature. In addition, Ppard-deficient microglia exhibited increased expression of genes associated with reactive oxygen species generation, phagocytosis and lipid clearance, M2-activation, and promotion of inflammation. Our results therefore suggest that PPAR-δ has an important role in microglia in limiting bystander tissue damage during neuroinflammation.

Macrophage ICAM-1 functions as a regulator of phagocytosis in LPS induced endotoxemia

OBJECTIVE

Intracellular adhesion molecule-1 (ICAM-1), a transmembrane glycoprotein belonging to the immunoglobulin superfamily, plays a critical role in mediating cell-cell interaction and outside-in cell signaling during the immune response. ICAM-1 is expressed on the cell surface of several cell types including endothelial cells, epithelial cells, leucocytes, fibroblasts, and neutrophils. Despite ICAM-1 has been detected on macrophage, little is known about the function and mechanism of macrophage ICAM-1.

METHODS

To investigate the role of lipopolysaccharide (LPS) in ICAM-1 regulation, both the protein and cell surface expression of ICAM-1 were measured. The phagocytosis of macrophage was evaluated by flow cytometry and Confocal microscopy. Small interfering RNA and neutralizing antibody of ICAM-1 were used to assess the effect of ICAM-1 on macrophage phagocytosis. TLR4 gene knockout mouse and cytoplasmic and mitochondrial ROS scavenger were used for the regulation of ICAM-1 expression. ROS was determined using flow cytometry.

RESULTS

In this study, we reported that macrophage can be stimulated to increase both the protein and cell surface expression of ICAM-1 by LPS. Macrophage ICAM-1 expression was correlated with enhanced macrophage phagocytosis. We found that using ICAM-1 neutralizing antibody or ICAM-1 silencing to attenuate the function or expression of ICAM-1 could decrease LPS-induced macrophage phagocytosis. Furthermore, we found that knocking out of TLR4 led to inhibited cytoplasmic and mitochondrial ROS production, which in turn, attenuated ICAM-1 expression at both the protein and cell surface levels.

CONCLUSION

This study demonstrates that the mechanism of ICAM-1-mediated macrophage phagocytosis is depending on TLR4-mediated ROS production and provides significant light on macrophage ICAM-1 in endotoxemia.

Effect of Eriocalyxin B on prostatic inflammation and pelvic pain in a mouse model of experimental autoimmune prostatitis

BACKGROUND

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is a common disease in males. Eriocalyxin B (EriB), a natural diterpenoid purified from Isodon eriocalyx var. laxiflora, was previously reported to have antitumor effects via multiple immune-related pathways. In this study, we investigated the effect of EriB on CP/CPPS using a mouse model of experimental autoimmune prostatitis (EAP) and explored its potential mechanisms.

METHODS

The EAP model was established in nonobese diabetic mice by intradermal injecting a mixture of prostate antigens and Complete Freund's Adjuvant on days 0 and 28. Then, EAP mice received daily intraperitoneal injections of EriB (5 or 10 mg/kg/d) for 14 days, from days 28 to 42 (EAP+EriB5 or EAP+EriB10 groups). The histopathological appearance of the prostate tissues was evaluated. Chronic pelvic pain development was assessed by cutaneous allodynia. Inflammatory cytokines were measured by enzyme-linked immunosorbent assay tests. We then explored anti-inflammatory potential mechanisms of EriB by studying the effects of PI3K inhibitor wortmannin (EAP+EriB10+Wort group) and NF-κB inhibitor SC75741 (EAP+EriB10+SC group) on prostate inflammation and pelvic pain using this model.

RESULTS

Histological analyses revealed significant prostate inflammation in EAP mice compared with control mice. Significantly increased pelvic pain was detected in EAP mice (P < .05). Compared with the EAP+Veh group, chronic pain development, histological appearance, and cytokine levels demonstrated that EriB could alleviate the severity of EAP in a dose-dependent manner though upregulation of the PI3K/Akt/mTOR pathway and downregulation of the NF-κB pathway. Further mechanism research demonstrated that the PI3K/AKT/mTOR pathway could be blocked by wortmannin, but was not affected by SC75741. In addition, the NF-κB pathway could be further inhibited by SC75741 compared with the EAP+EriB10+Veh group. However, wortmannin could reactivate the NF-κB pathway, indicating that the PI3K/AKT/mTOR pathway negatively regulates the NF-κB pathway during EriB treatment.

CONCLUSIONS

The results of the present study suggested that EriB could alleviate the severity of prostatic inflammation and pelvic pain in an EAP mouse model. These findings may broaden the value of EriB as a promising candidate for the treatment of CP/CPPS.

Targeting PI3K/Akt/mTOR in AML: Rationale and Clinical Evidence

Acute myeloid leukemia (AML) is a highly heterogeneous hematopoietic malignancy characterized by excessive proliferation and accumulation of immature myeloid blasts in the bone marrow. AML has a very poor 5-year survival rate of just 16% in the UK; hence, more efficacious, tolerable, and targeted therapy is required. Persistent leukemia stem cell (LSC) populations underlie patient relapse and development of resistance to therapy. Identification of critical oncogenic signaling pathways in AML LSC may provide new avenues for novel therapeutic strategies. The phosphatidylinositol-3-kinase (PI3K)/Akt and the mammalian target of rapamycin (mTOR) signaling pathway, is often hyperactivated in AML, required to sustain the oncogenic potential of LSCs. Growing evidence suggests that targeting key components of this pathway may represent an effective treatment to kill AML LSCs. Despite this, accruing significant body of scientific knowledge, PI3K/Akt/mTOR inhibitors have not translated into clinical practice. In this article, we review the laboratory-based evidence of the critical role of PI3K/Akt/mTOR pathway in AML, and outcomes from current clinical studies using PI3K/Akt/mTOR inhibitors. Based on these results, we discuss the putative mechanisms of resistance to PI3K/Akt/mTOR inhibition, offering rationale for potential candidate combination therapies incorporating PI3K/Akt/mTOR inhibitors for precision medicine in AML.

Piceatannol suppresses proliferation and induces apoptosis by regulation of the microRNA‑21/phosphatase and tensin homolog/protein kinase B signaling pathway in osteosarcoma cells

Piceatannol (Pice), a natural analog of resveratrol, has been identified as an anticancer agent in various cancers by modulating the expression of microRNAs (miRNAs/miRs). However, the molecular mechanisms underlying the anticancer effects of Pice in osteosarcoma (OS) cells remain unclear. Thus, we hypothesized that Pice exerts anticancer effects on OS cells via the regulation of miRNA expression. Herein, we performed a MTT assay and flow cytometric analysis to determine cell viability and apoptosis in OS cells treated with Pice, respectively. Our results showed that Pice inhibits proliferation in a dose-dependent manner induces the apoptosis of OS cells. More importantly, miRNA microarray analysis identified that Pice alters miRNA expression profiles in human OS cells after treatment with Pice, and miR-21 was the most significantly downregulated. In addition, the therapeutic effects of Pice on OS cells were weakened by restoration of miR-21. In addition, we further verified that phosphatase and tensin homolog (PTEN), a tumor suppressor gene, is the functional target of miR-21 and Pice blocks the PTEN/AKT signaling pathway through inhibiting miR-21 expression in OS cells. Our findings suggested that Pice may exert anticancer effects on OS cells via mediating the miR-21/PTEN/AKT signaling pathway and could be considered to be a potential anticancer agent for treating OS.

Shank-associated RH domain interactor signaling in tumorigenesis

Shank-associated RH domain interactor (SHARPIN) is a component of the linear ubiquitin chain activation complex, which is essential for p53 signaling and inflammation. Previous studies have demonstrated that SHARPIN functions in tumor cell survival, growth, invasion and tumorigenesis. These functions include the regulation of p53 proteins via poly-ubiquitination, interaction with a type II protein arginine methyltransferase 5 in melanoma cells, modulating ras-associated protein-1 through p38 and c-Jun N-terminal kinases/c-Jun signaling, and mediating phosphoinositide 3-kinase/AKT signaling via phosphatase and tensin homologue deleted on chromosome 10. Hence, SHARPIN not only participates in the inflammatory response but also serves a critical role in tumor cells. The present review summarizes the biological functions of the absence or presence of SHARPIN with regard to activating the canonical NF-κB signaling pathway and the effects on p53 and other signaling pathways for the modulation of tumorigenesis. Therefore, this review provides insight into the underlying role and mechanisms of SHARPIN in tumorigenesis, as well as its potential application in cancer therapy.

Transcription box‑3 protects human umbilical vein endothelial cells in a high‑glucose environment through sirtuin 1/AKT signaling

The increasing burden of diabetes in low and middle-income countries is attributable to both genetic and epigenetic factors. Environmental- and lifestyle-associated changes are also considered to be important contributors to this disease. The resultant co-morbidities arising from micro-and macrovascular changes in diabetes are difficult to manage and are an economic burden. However, very little is known about the molecular mechanisms that drive this phenotype. The present study aimed to investigate the role of sirtuin 1 (SIRT1)- and transcription box-3 (TBX-3)-mediated regulation of endothelial dysfunction, given the significance of SIRT1 in glucose metabolism and the role of TBX-3 in the maintenance of cellular proliferation, senescence and apoptosis. Following the recruitment of adult patients with and without diabetes, both SIRT1 and TBX-3 expression was confirmed to be present in the sera of the patients with diabetes and the patients without diabetes; however, both SIRT1 and TBX-3 expression levels were higher in the sera of the patients with diabetes. Human umbilical vein endothelial cells (HUVECs) were further used for in vitro studies. Using TBX-3 and SIRT1 knockdown models, the cellular responses to proliferation, migration, invasion and tube formation were investigated using an MTS, cell cycle analysis, wound healing, Transwell and tube formation assay, respectively. Western blotting was also used to determine the downstream signaling pathways involved. The genetic knockdown of TBX-3 in hyperglycemic conditions significantly decreased the cellular proliferation, migration, invasion and angiogenesis of HUVECs. It was subsequently identified that TBX-3 mediated its effects through the activation of AKT and vascular endothelial growth factor (VEGF) signaling. However, the genetic knockdown of SIRT1 in the presence of TBX-3 overexpression and glucose failed to activate the AKT and VEGF signaling pathways. In conclusion, the results of the present study suggested that SIRT1 may positively regulate TBX-3 in endothelial cells, therefore, SIRT1 and/or TBX-3 may serve as potential novel biomarkers for disease progression.

The Implication of Oxidative Stress and AMPK-Nrf2 Antioxidative Signaling in Pneumonia Pathogenesis

It is widely recognized that chemical, physical, and biological factors can singly or synergistically evoke the excessive production of oxidative stress in pulmonary tissue that followed by pulmonary lesions and pneumonia. In addition, metabolic and endocrine disorder-induced diseases such as diabetes and obesity often expressed higher susceptibility to pulmonary infections, and presented severe symptoms which increasing the mortality rate. Therefore, the connection between the lesion of the lungs and the metabolic/endocrine disorders is an interesting and essential issue to be addressed. Studies have noticed a similar pathological feature in both infectious pneumonia and metabolic disease-intercurrent pulmonary lesions, that is, from the view of molecular pathology, the accumulation of excessive reactive oxygen species (ROS) in pulmonary tissue accompanying with activated pro-inflammatory signals. Meanwhile, Adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) and nuclear factor erythroid-2-related factor 2 (Nrf2) signaling plays important role in metabolic/endocrine homeostasis and infection response, and it's closely associated with the anti-oxidative capacity of the body. For this reason, this review will start from the summary upon the implication of ROS accumulation, and to discuss how AMPK-Nrf2 signaling contributes to maintaining the metabolic/endocrine homeostasis and attenuates the susceptibility of pulmonary infections.

Diet induces hepatocyte protection in fatty liver disease via modulation of PTEN signaling

Fatty liver disease (FLD) is characterized by accumulation of excess fat in the liver. The underlying molecular mechanism associated with the progression of the disease has been in elusive. Hepatocellular demise due to increased oxidative stress resulting in an inflammatory response may be a key feature in FLD. Recent advances in molecular biology have led to an improved understanding of the molecular pathogenesis, suggesting a critical association between the PI3K/AKT/PTEN signaling pathway and FLD. In particular, PTEN has been associated with regulating the pathogenesis of hepatocyte degeneration. Given the function of mitochondria in reactive oxygen species (ROS) generation and the initiation of oxidative stress, the mitochondrial antioxidant network is of interest. It is vital to balance the activity of intracellular key molecules to maintain a healthy liver. Consequently, onset of FLD may be delayed using dietary protective agents that alter PTEN signaling and reduce ROS levels. The advancement of research on dietary regulation with a focus on modulatory roles in ROS generation and PTEN associated signaling is summarized in the current study, supporting further preventive and therapeutic exploration.

10-gingerol induces oxidative stress through HTR1A in cumulus cells: in-vitro and in-silico studies

Background We investigated whether 10-gingerol is able to induce oxidative stress in cumulus cells. Methods For the in-vitro research, we used a cumulus cell culture in M199, containing 10-gingerol in various concentrations (0, 12, 16, and 20 µM), and detected oxidative stress through superoxide dismutase (SOD) activity and malondialdehyde (MDA) concentrations, with incubation periods of 24, 48, 72, and 96 h. The obtained results were confirmed by in-silico studies. Results The in-vitro data revealed that SOD activity and MDA concentration increased with increasing incubation periods: SOD activity at 0 µM (1.39 ± 0.24i), 12 µM (16.42 ± 0.35ab), 16 µM (17.28 ± 0.55ab), 20 µM (17.81 ± 0.12a), with a contribution of 71.1%. MDA concentration at 0 µM (17.82 ± 1.39 l), 12 µM (72.99 ± 0.31c), 16 µM (79.77 ± 4.19b), 20 µM (85.07 ± 2.57a), with a contribution of 73.1%. Based on this, the in-silico data uncovered that 10-gingerol induces oxidative stress in cumulus cells by inhibiting HTR1A functions and inactivating GSK3B and AKT-1. Conclusions 10-gingerol induces oxidative stress in cumulus cells through enhancing SOD activity and MDA concentration by inhibiting HTR1A functions and inactivating GSK3B and AKT-1.

Ursodeoxycholic acid inhibits intimal hyperplasia, vascular smooth muscle cell excessive proliferation, migration via blocking miR-21/PTEN/AKT/mTOR signaling pathway

Excessive migration and proliferation of vascular smooth muscle cells (VSMCs) are critical cellular events that lead to intimal hyperplasia in atherosclerosis and restenosis. In this study, we investigated the protective effects of ursodeoxycholic acid (UDCA) on intimal hyperplasia and VSMC proliferation and migration, and the underlying mechanisms by which these events occur. A rat unilateral carotid artery was ligated to induce vascular injury and the microRNA (miRNA) expression profiles were determined using miRNA microarray analysis. We observed that UDCA significantly reduced the degree of intimal hyperplasia and induced miR-21 dysregulation. Restoration of miR-21 by agomir-miR-21 reversed the protective effects of UDCA on intimal hyperplasia and proliferation in vivo. In vitro, UDCA suppressed PDGF-BB-induced VSMC proliferation, invasion and migration in a dose-dependent manner, whereas the suppressive effect of UDCA was abrogated by overexpression of miR-21 in PDGF-BB-incubated VSMCs. Furthermore, we identified that miR-21 in VSMCs targeted the phosphatase and tensin homolog (PTEN), a tumor suppressor gene, negatively modulated the AKT/mTOR pathway. More importantly, we observed that that UDCA suppressed AKT/mTOR signaling pathway in the carotid artery injury model, whereas this pathway was reactivated by overexpression of miR-21. Taken together, our findings indicated that UDCA inhibited intimal hyperplasia and VSMCs excessive migration and proliferation via blocking miR-21/PTEN/AKT/mTOR signaling pathway, which suggests that UDCA may be a promising candidate for the therapy of atherosclerosis.

Hyaluronan-binding protein 1 (HABP1) overexpression triggers induction of senescence in fibroblasts cells

Hyaluronan-binding protein 1 (HABP1), a multi-compartmental, multi-functional protein has a wide range of functions, which can be attributed to its ability to associate with a variety of cellular ligands. Earlier we have reported that HABP1 overexpression in rat normal fibroblasts (F-HABP07) shows chronic generation of reactive oxygen species (ROS), induction of autophagy, and apoptosis. However, a significant proportion of cells remained viable after the majority went through apoptosis from 60 to 72 h. In this study, an attempt has been made to delineate the cellular events in the declined population of surviving cells. It has been elucidated here that, these cells at later time points of growth, that is, 72 and 84 h, not only appeared to shrink but also are devoid of autophagic vacuoles and displayed polyploidy. F-HABP07 cells exhibited an altered cytoskeletal structure from their parental cell line F111, assumed to be caused upon inhibition of actin polymerization and decrease in IQ motif-containing GTPase activating protein 1 (IQGAP1), a key protein associated with maintenance of cytoskeletal integrity. Enhanced expression and nuclear localization of AKT observed in F-HABP07 cells appears to be contributing toward the maintenance of high ROS levels in these cells and also potentially modulating the IQGAP1 activity. These observations, in fact have been considered to result in sustained DNA damage, which then leads to increased expression of p53 and activation of p21 and carry out the cellular events responsible for senescence. Subsequent assessment of the presence of positive β-gal staining and enhanced expression of p16^INK4a in F-HABP07, confirmed that HABP1 overexpressing fibroblasts undergo senescence.

Microglia Mediated Neuroinflammation: Focus on PI3K Modulation

Immune activation in the central nervous system involves mostly microglia in response to pathogen invasion or tissue damage, which react, promoting a self-limiting inflammatory response aimed to restore homeostasis. However, prolonged, uncontrolled inflammation may result in the production by microglia of neurotoxic factors that lead to the amplification of the disease state and tissue damage. In particular, specific inducers of inflammation associated with neurodegenerative diseases activate inflammatory processes that result in the production of a number of mediators and cytokines that enhance neurodegenerative processes. Phosphoinositide 3-kinases (PI3Ks) constitute a family of enzymes regulating a wide range of activity, including signal transduction. Recent studies have focused attention on the intracellular role of PI3K and its contribution to neurodegenerative processes. This review illustrates and discusses recent findings about the role of this signaling pathway in the modulation of microglia neuroinflammatory responses linked to neurodegeneration. Finally, we discuss the modulation of PI3K as a potential therapeutic approach helpful for developing innovative therapeutic strategies in neurodegenerative diseases.

The Role of the Reactive Oxygen Species Scavenger Agent, Astaxanthin, in the Protection of Cisplatin-Treated Patients Against Hearing Loss

Emerging evidence of significant hearing loss occurring shortly after cisplatin administration in cancer patients has stimulated research into the causes and treatment of this side effect. Although the aetiology of cisplatin-induced hearing loss (CIHL) remains unknown, an increasing body of research suggests that it is associated with excessive generation of intracellular reactive oxygen species (ROS) in the cochlea. Astaxanthin, a xanthophyll carotenoid, has powerful anti-oxidant, anti-inflammatory, and anti-apoptotic properties based on its unique cell membrane function, diverse biological activities, and ability to permeate the blood-brain barrier. In this review, we summarize the role of ROS in CIHL and the effect of astaxanthin on inhibiting ROS production. We focus on investigating the mechanism of action of astaxanthin in suppressing excessive production of ROS.

Glucose Depletion Enhances the Stem Cell Phenotype and Gemcitabine Resistance of Cholangiocarcinoma Organoids through AKT Phosphorylation and Reactive Oxygen Species

Cancer cells are strongly dependent on the glycolytic pathway for generation of energy even under aerobic condition through a phenomenon known as the Warburg effect. Rapid proliferation of cancer cells is often accompanied by high glucose consumption and abnormal angiogenesis, which may lead to glucose depletion. In the present study, we investigated how cholangiocarcinoma cells adapt to glucose depletion using a 3D organoid culture system. We cultured organoids derived from cholangiocarcinoma under glucose-free condition and investigated cell proliferation, expression of stem cell markers and resistance to gemcitabine. Cholangiocarcinoma organoids cultured under glucose-free condition showed reduced proliferation but were able to survive. We also observed an increase in the expression of stem cell markers including LGR5 and enhancement of stem cell phenotypic characteristics such as resistance to gemcitabine through AKT phosphorylation and reactive oxygen species. These findings indicate that cholangiocarcinoma cells are able to adapt to glucose depletion through enhancement of their stem cell phenotype in response to changes in microenvironmental conditions.

Liensinine inhibited gastric cancer cell growth through ROS generation and the PI3K/AKT pathway

Liensinine, an isoquinoline alkaloid extracted from the seed embryo of Nelumbo nucifera Gaertn, has been shown to exhibit various phrenological effects, including anti‑cancer activity. The aim of this study is to investigate the effects and mechanisms of liensinine in human gastric cancer cells. In this study, we found liensinine can significantly inhibit gastric cancer cell proliferation in vitro and in vivo. Liensinine inducedgastric cancer cell apoptosis by increasing cleaved PARP, caspased 3 and caspased 9. Moreover, liensinine induced cycle arrest by downregulatingcyclinD1/cyclin‑dependent kinase4 and phosphorylated protein kinase B. Furthermore, we found liensinine increases ROS levels and inhibits the PI3K/AKT pathway. These data suggested that liensinine might represent a novel and effective agent against gastric cancer.

The interrelationship between cerebral ischemic stroke and glioma: a comprehensive study of recent reports

Glioma and cerebral ischemic stroke are two major events that lead to patient death worldwide. Although these conditions have different physiological incidences, ~10% of ischemic stroke patients develop cerebral cancer, especially glioma, in the postischemic stages. Additionally, the high proliferation, venous thrombosis and hypercoagulability of the glioma mass increase the significant risk of thromboembolism, including ischemic stroke. Surprisingly, these events share several common pathways, viz. hypoxia, cerebral inflammation, angiogenesis, etc., but the proper mechanism behind this co-occurrence has yet to be discovered. The hypercoagulability and presence of the D-dimer level in stroke are different in cancer patients than in the noncancerous population. Other factors such as atherosclerosis and coagulopathy involved in the pathogenesis of stroke are partially responsible for cancer, and the reverse is also partially true. Based on clinical and neurosurgical experience, the neuronal structures and functions in the brain and spine are observed to change after a progressive attack of ischemia that leads to hypoxia and atrophy. The major population of cancer cells cannot survive in an adverse ischemic environment that excludes cancer stem cells (CSCs). Cancer cells in stroke patients have already metastasized, but early-stage cancer patients also suffer stroke for multiple reasons. Therefore, stroke is an early manifestation of cancer. Stroke and cancer share many factors that result in an increased risk of stroke in cancer patients, and vice-versa. The intricate mechanisms for stroke with and without cancer are different. This review summarizes the current clinical reports, pathophysiology, probable causes of co-occurrence, prognoses, and treatment possibilities.

Sustained Akt signaling in articular chondrocytes causes osteoarthritis via oxidative stress-induced senescence in mice

Osteoarthritis (OA) is an age-related disorder that is strongly associated with chondrocyte senescence. The causal link between disruptive PTEN/Akt signaling and chondrocyte senescence and the underlying mechanism are unclear. In this study, we found activated Akt signaling in human OA cartilage as well as in a mouse OA model with surgical destabilization of the medial meniscus. Genetic mouse models mimicking sustained Akt signaling in articular chondrocytes via PTEN deficiency driven by either Col2a1-Cre or Col2a1-Cre^ERT2 developed OA, whereas restriction of Akt signaling reversed the OA phenotypes in PTEN-deficient mice. Mechanistically, prolonged activation of Akt signaling caused an accumulation of reactive oxygen species and triggered chondrocyte senescence as well as a senescence-associated secretory phenotype, whereas chronic administration of the antioxidant N-acetylcysteine suppressed chondrocyte senescence and mitigated OA progression in PTEN-deficient mice. Therefore, inhibition of Akt signaling by PTEN is required for the maintenance of articular cartilage. Disrupted Akt signaling in articular chondrocytes triggers oxidative stress-induced chondrocyte senescence and causes OA.

ROS Generation and Antioxidant Defense Systems in Normal and Malignant Cells

Reactive oxygen species (ROS) are by-products of normal cell activity. They are produced in many cellular compartments and play a major role in signaling pathways. Overproduction of ROS is associated with the development of various human diseases (including cancer, cardiovascular, neurodegenerative, and metabolic disorders), inflammation, and aging. Tumors continuously generate ROS at increased levels that have a dual role in their development. Oxidative stress can promote tumor initiation, progression, and resistance to therapy through DNA damage, leading to the accumulation of mutations and genome instability, as well as reprogramming cell metabolism and signaling. On the contrary, elevated ROS levels can induce tumor cell death. This review covers the current data on the mechanisms of ROS generation and existing antioxidant systems balancing the redox state in mammalian cells that can also be related to tumors.

Tumoral NOX4 recruits M2 tumor-associated macrophages via ROS/PI3K signaling-dependent various cytokine production to promote NSCLC growth

M2-type tumor-associated macrophages (TAMs) infiltration contributes to cancer malignant progression. However, the mechanisms for controlling recruitment and M2 polarization of macrophages by cancer cells are largely unclear. NADPH oxidase 4 (NOX4) is abundantly expressed in non-small cell lung cancer (NSCLC) and mediates cancer progression. NOXs are in close relation with cancer-related inflammation, nevertheless, whether tumoral NOXs influence microenvironmental macrophages remains undentified. This study found that there was a close association between NOX4 expression and macrophage chemotaxis in patients with NSCLC analyzed using TCGA RNA-sequencing data. NOX4 in NSCLC cells (A549 and Calu-1 cell lines) efficiently enhanced murine peritoneal macrophage migration and induces M2 polarization. Immunohistochemical analysis of clinical specimens confirmed the positive correlation of NOX4 and CD68 or CD206. The mechanical study revealed that tumoral NOX4-induced reactive oxygen species (ROS) stimulated various cytokine production, including CCL7, IL8, CSF-1 and VEGF-C, via PI3K/Akt signaling-dependent manner. Blockade of the function of these cytokines reversed NOX4 effect on macrophages. Specifically, the results showed that tumoral NOX4-educated M2 macrophages exhibited elevated JNK activity, expressed and released HB-EGF, thus facilitating NSCLC proliferation in vitro. Pretreatment of macrophages with JNK inhibitor blocked tumoral NOX4-induced HB-EGF production in M2 macrophages. Finally, in a xenograft mouse model, overexpression of NOX4 in A549 cells enhanced the tumor growth. Elimination of ROS by NAC or inhibition of NOX4 activity by GKT137831 suppressed tumor growth accompanied by reduction in macrophage infiltration and the percentage of M2 macrophages. In conclusion, our study indicates that tumoral NOX4 recruits M2 TAMs via ROS/PI3K signaling-dependent various cytokine production, thus contributing NSCLC cell growth.

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NOX4 has a novel function that affects cancer progression via action on TAM.

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There exists a NOX4-dependent crosstalk between NSCLC cells and M2 macrophages.

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GKT137831 has anti-cancer potential for targeting cancer microenvironmental TAM.

Developmental Exposure to Di-(2-ethylhexyl) Phthalate Induces Cerebellar Granule Cell Apoptosis via the PI3K/AKT Signaling Pathway

Di-(2-ethylhexyl) phthalate (DEHP) is an ubiquitous environmental contaminant because of its extensive use in plastics and its persistence. As an environmental endocrine disruptor, it is suspected to interfere with neurodevelopment in people. However, evidence of the effects of maternal DEHP exposure on cerebellar development in offspring is scarce. The objective of this study was to investigate maternal exposure to DEHP and its effect on apoptosis of cerebellar granule cells (CGCs) and related mechanisms. Pregnant Wistar rats were administrated DEHP (0, 30, 300 and 750 mg/kg/d) by gavage from gestational day (GD) 0 to postnatal day (PN) 21. Primary CGCs were also exposed to mono-(2-ethylhexyl) phthalate (MEHP), the main metabolite of DEHP, for 24 h with concentrations of 0, 25, 100 and 250 µM. The CGCs of male offspring from 300 and 750 mg/kg/d DEHP exposure groups showed significantly increased apoptosis. In addition, the PI3K/AKT signaling pathway was inhibited in the male offspring of the 300 and 750 mg/kg/d DEHP exposure groups. However, effects on female pups were not obvious. Apoptosis was also elevated and the PI3K/AKT signaling pathway was inhibited after primary CGCs were exposed to MEHP. Furthermore, apoptosis was reduced after treatment with the PI3K/AKT signaling pathway activator, insulin-like growth factor (IGF) 1, and increased after treatment with LY294002, an inhibitor of the PI3K/AKT signaling pathway. These results suggested that maternal DEHP exposure induced apoptosis in the CGCs of male pups via the PI3K/AKT signaling pathway, and the apoptosis could be rescued by IGF1 and aggravated by LY294002.

Signalling pathways involved in p47phox -dependent reactive oxygen species in platelets of endotoxemic rats

Thrombocytopenia during sepsis is associated with a less favourable clinical outcome. Overproduction of reactive oxygen species (ROS) by different cell types contributes to sepsis. Platelets generate ROS, but the upstream pathways of NADPH oxidase activation are not completely understood. Here, we designed experiments in washed platelets from lipopolysaccharide (LPS)-treated rats to investigate the p47^phox activation and ROS generation, and its modulation by c-Src family kinase (c-Src), phosphoinositide 3-kinase (PI3K), protein kinase C (PKC) and protein kinase G (PKG). Rats were injected intraperitoneally with LPS (1 mg/kg), and at 48 hours thereafter, arterial blood was collected and washed platelets were obtained. Washed platelets were pre-incubated with different inhibitors and subsequently activated or not with ADP. Flow cytometry, Western blotting and ELISA were performed. We found that LPS significantly increased the p47^phox phosphorylation and ROS generation compared with the control group (P < 0.05). The enhanced ROS production in the LPS group was unaffected by the non-selective SFKs inhibitor PP2, the PI3K inhibitor wortmannin or the Akt inhibitor PPI-1. The cyclic GMP levels were 115% higher in activated platelets of LPS compared with the saline group (P < 0.05). Moreover, in the LPS group, the sGC inhibitor ODQ, the PKG inhibitor Rp-8-Br and the PKC inhibitor GF109203X abrogated the increased p47^phox phosphorylation and reduced the ROS levels. In conclusion, selective inhibitors of cGMP-PKG and PKC-p47^phox pathways that regulate ROS generation by LPS in platelets may help control the redox balance in sepsis improving the survival of patients.

Alpha-fetoprotein inhibits autophagy to promote malignant behaviour in hepatocellular carcinoma cells by activating PI3K/AKT/mTOR signalling

Alpha-fetoprotein (AFP) has been recognized as a key regulator of cell proliferation in hepatocellular carcinoma (HCC). However, whether AFP functions in cancer cell autophagy remains unknown. This study investigated the effects of AFP on autophagy in HCC cells. The role of AFP was studied in two HCC cell lines, PLC/PRF/5 and HLE. Cell autophagy, apoptosis, proliferation, migration and invasion were analysed with Western blotting, co-immunoprecipitation (CoIP), immunofluorescence, animal models, MTT assays, flow cytometry (FCM), Cell Counting Kit (CCK)-8, and scratch and transwell assays. In PLC/PRF/5 cells, AFP interacted with PTEN and activated PI3K/Akt/mTOR signalling. In HLE cells, overexpressed AFP similarly interacted with PTEN, leading to PI3K/Akt/mTOR activation and reduced cell autophagy. When AFP was silenced in PLC/PRF/5 cells, cell proliferation, tumour growth, migration and invasion were inhibited, and the numbers of S-phase and apoptotic cells were increased. In contrast, AFP overexpression in HLE cells enhanced cell proliferation, migration and invasion and reduced apoptosis. AFP-dependent autophagy, proliferation, migration and apoptosis were inhibited by rapamycin. In summary, AFP plays critical roles in the inhibition of autophagy and apoptosis in HCC cells and promotes proliferation, migration and invasion. The role of AFP in autophagy inhibition in HCC cells may involve the activation of PI3K/Akt/mTOR signalling.

Sirt3-mediated mitochondrial fission regulates the colorectal cancer stress response by modulating the Akt/PTEN signalling pathway

Sirtuin-3 (Sirt3), a sub-family member of the nicotinamide adenine dinucleotide-dependent histone deacetylases, has been reported to be involved in mitochondrial oxidative stress regulation, mitochondrial calcium management, mitophagy activation, and mitochondrial energy metabolism. The aim of our study was to explore the functional role of Sirt3 in colorectal cancer stress, focusing particularly on its effects on mitochondrial fission. Our study demonstrated that Sirt3 was highly upregulated in colorectal cancer cells compared to normal rectal mucosa cells. However, the genetic ablation of Sirt3 reduced colorectal cancer cell viability, mobility and proliferation. At the molecular level, we found that Sirt3 knockdown suppressed the expression of adhesive factors and cyclins. Furthermore, Sirt3 deletion was also associated with mitochondrial membrane potential reduction, ROS overproduction, mPTP opening, mitochondrial pro-apoptotic upregulation, and caspase-9-related death programme activation. Furthermore, we determined that Sirt3 regulated the colorectal cancer stress response by modulating mitochondrial fission. The loss of Sirt3 triggered fatal mitochondrial fission by suppressing the Akt/PTEN pathway. Re-activation of the Akt/PTEN pathway combatted mitochondrial fission and promoted colorectal cancer mobility, survival, and growth. Altogether, these findings provide an additional rationale for the function of Sirt3 in supporting the growth and survival of colorectal cancer.

Reactive Oxygen Species, Superoxide Dimutases, and PTEN-p53-AKT-MDM2 Signaling Loop Network in Mesenchymal Stem/Stromal Cells Regulation

Mesenchymal stromal/stem cells (MSCs) are multipotent cells that can differentiate to various specialized cells, which have the potential capacity to differentiate properly and accelerate recovery in damaged sites of the body. This stem cell technology has become the fundamental element in regenerative medicine. As reactive oxygen species (ROS) have been reported to adversely influence stem cell properties, it is imperative to attenuate the extent of ROS to the promising protective approach with MSCs’ regenerative therapy. Oxidative stress also affects the culture expansion and longevity of MSCs. Therefore, there is great need to identify a method to prevent oxidative stress and replicative senescence in MSCs. Phosphatase and tensin homologue deleted on chromosome 10/Protein kinase B, PKB (PTEN/AKT) and the tumor suppressor p53 pathway have been proven to play a pivotal role in regulating cell apoptosis by regulating the oxidative stress and/or ROS quenching. In this review, we summarize the current research and our view of how PTEN/AKT and p53 with their partners transduce signals downstream, and what the implications are for MSCs’ biology.

Implications of PI3K/AKT/PTEN Signaling on Superoxide Dismutases Expression and in the Pathogenesis of Alzheimer's Disease

Alzheimer’s disease is a neurodegenerative sickness, where the speed of personal disease progression differs prominently due to genetic and environmental factors such as life style. Alzheimer’s disease is described by the construction of neuronal plaques and neurofibrillary tangles composed of phosphorylated tau protein. Mitochondrial dysfunction may be a noticeable feature of Alzheimer’s disease and increased production of reactive oxygen species has long been described. Superoxide dismutases (SODs) protect from excess reactive oxygen species to form less reactive hydrogen peroxide. It is suggested that SODs can play a protective role in neurodegeneration. In addition, PI3K/AKT pathway has been shown to play a critical role on the neuroprotection and inhibiting apoptosis via the enhancing expression of the SODs. This pathway appears to be crucial in Alzheimer’s disease because it is related to the tau protein hyper-phosphorylation. Dietary supplementation of several ordinary compounds may provide a novel therapeutic approach to brain disorders by modulating the function of the PI3K/AKT pathway. Understanding these systems may offer a better efficacy of new therapeutic approaches. In this review, we summarize recent progresses on the involvement of the SODs and PI3K/AKT pathway in neuroprotective signaling against Alzheimer’s disease.

Microrna-217 modulates human skin fibroblast senescence by directly targeting DNA methyltransferase 1

DNA methyltransferase 1 (DNMT1) is a major epigenetic regulator associated with many biological processes. However, the roles and mechanisms of DNMT1 in skin aging are incompletely understood. Here we explored the role of DNMT1 in human skin fibroblasts senescence and its related regulatory mechanisms. DNMT1 expression decreased in passage-aged fibroblasts and DNMT1 silencing in young fibroblasts induced the senescence phenotype. MiR-217 is predicted to target DNMT1 mRNA and miR-217 expression increased in passage-aged fibroblasts. MiR-217 directly targeted the 3′-untranslated region (3′-UTR) of DNMT1 in HEK 293T cells and inhibited DNMT1 expression in fibroblasts. MiR-217 overexpression induced a senescence phenotype in young fibroblasts, and miR-217 downregulation in old HSFs partially reversed the senescence phenotype. However, these effects could be significantly rescued by regulating DNMT1 expression in fibroblasts. After regulating miR-217 levels, we analyzed changes in the promoter methylation levels of 24 senescent-associated genes, finding that 6 genes were significantly altered, and verified p16 and phosphorylated retinoblastoma (pRb) protein levels. Finally, an inverse correlation between DNMT1 and miR-217 expression was observed in skin tissues and different-aged fibroblasts. Together, these findings revealed that miR-217 promotes fibroblasts senescence by suppressing DNMT1-mediated methylation of p16 and pRb by targeting the DNMT1 3′-UTR.

Role of Oxidative Stress as Key Regulator of Muscle Wasting during Cachexia

Skeletal muscle atrophy is a pathological condition mainly characterized by a loss of muscular mass and the contractile capacity of the skeletal muscle as a consequence of muscular weakness and decreased force generation. Cachexia is defined as a pathological condition secondary to illness characterized by the progressive loss of muscle mass with or without loss of fat mass and with concomitant diminution of muscle strength. The molecular mechanisms involved in cachexia include oxidative stress, protein synthesis/degradation imbalance, autophagy deregulation, increased myonuclear apoptosis, and mitochondrial dysfunction. Oxidative stress is one of the most common mechanisms of cachexia caused by different factors. It results in increased ROS levels, increased oxidation-dependent protein modification, and decreased antioxidant system functions. In this review, we will describe the importance of oxidative stress in skeletal muscles, its sources, and how it can regulate protein synthesis/degradation imbalance, autophagy deregulation, increased myonuclear apoptosis, and mitochondrial dysfunction involved in cachexia.

Regulation of type I interferon responses by mitochondria-derived reactive oxygen species in plasmacytoid dendritic cells

Mitochondrial reactive oxygen species (mtROS) generated continuously under physiological conditions have recently emerged as critical players in the regulation of immune signaling pathways. In this study we have investigated the regulation of antiviral signaling by increased mtROS production in plasmacytoid dendritic cells (pDCs), which, as major producers of type I interferons (IFN), are the key coordinators of antiviral immunity. The early phase of type I IFN production in pDCs is mediated by endosomal Toll-like receptors (TLRs), whereas the late phase of IFN response can also be triggered by cytosolic retinoic acid-inducible gene-I (RIG-I), expression of which is induced upon TLR stimulation. Therefore, pDCs provide an ideal model to study the impact of elevated mtROS on the antiviral signaling pathways initiated by receptors with distinct subcellular localization. We found that elevated level of mtROS alone did not change the phenotype and the baseline cytokine profile of resting pDCs. Nevertheless increased mtROS levels in pDCs lowered the TLR9-induced secretion of pro-inflammatory mediators slightly, whereas reduced type I IFN production markedly via blocking phosphorylation of interferon regulatory factor 7 (IRF7), the key transcription factor of the TLR9 signaling pathway. The TLR9-induced expression of RIG-I in pDCs was also negatively regulated by enhanced mtROS production. On the contrary, elevated mtROS significantly augmented the RIG-I-stimulated expression of type I IFNs, as well as the expression of mitochondrial antiviral-signaling (MAVS) protein and the phosphorylation of Akt and IRF3 that are essential components of RIG-I signaling. Collectively, our data suggest that increased mtROS exert diverse immunoregulatory functions in pDCs both in the early and late phase of type I IFN responses depending on which type of viral sensing pathway is stimulated.

4-hydroxynonenal-mediated signaling and aging

4-Hydroxy-2-nonenal (HNE), one of the major α, β-unsaturated aldehydes produced during lipid peroxidation, is a potent messenger in mediating signaling pathways. Lipid peroxidation and HNE production appear to increase with aging. Although the cause and effect relation remains arguable, aging is associated with significant changes in diverse signaling events, characterized by enhanced or diminished responses of specific signaling pathways. In this review we will discuss how HNE may contribute to aging-related alterations of signaling pathways.

Oxidative Stress Regulation on Endothelial Cells by Hydrophilic Astaxanthin Complex: Chemical, Biological, and Molecular Antioxidant Activity Evaluation

An imbalance in the reactive oxygen species (ROS) homeostasis is involved in the pathogenesis of oxidative stress-related diseases. Astaxanthin, a xanthophyll carotenoid with high antioxidant capacities, has been shown to prevent the first stages of oxidative stress. Here, we evaluate the antioxidant capacities of astaxanthin included within hydroxypropyl-beta-cyclodextrin (CD-A) to directly and indirectly reduce the induced ROS production. First, chemical methods were used to corroborate the preservation of astaxanthin antioxidant abilities after inclusion. Next, antioxidant scavenging properties of CD-A to inhibit the cellular and mitochondrial ROS by reducing the disturbance in the redox state of the cell and the infiltration of lipid peroxidation radicals were evaluated. Finally, the activation of endogenous antioxidant PTEN/AKT, Nrf2/HO-1, and NQOI gene and protein expression supported the protective effect of CD-A complex on human endothelial cells under stress conditions. Moreover, a nontoxic effect on HUVEC was registered after CD-A complex supplementation. The results reported here illustrate the need to continue exploring the interesting properties of this hydrophilic antioxidant complex to assist endogenous systems to counteract the ROS impact on the induction of cellular oxidative stress state.

Redox regulation in tumor cell epithelial-mesenchymal transition: molecular basis and therapeutic strategy

Epithelial–mesenchymal transition (EMT) is recognized as a driving force of cancer cell metastasis and drug resistance, two leading causes of cancer recurrence and cancer-related death. It is, therefore, logical in cancer therapy to target the EMT switch to prevent such cancer metastasis and recurrence. Previous reports have indicated that growth factors (such as epidermal growth factor and fibroblast growth factor) and cytokines (such as the transforming growth factor beta (TGF-β) family) are major stimulators of EMT. However, the mechanisms underlying EMT initiation and progression remain unclear. Recently, emerging evidence has suggested that reactive oxygen species (ROS), important cellular secondary messengers involved in diverse biological events in cancer cells, play essential roles in the EMT process in cancer cells by regulating extracellular matrix (ECM) remodeling, cytoskeleton remodeling, cell–cell junctions, and cell mobility. Thus, targeting EMT by manipulating the intracellular redox status may hold promise for cancer therapy. Herein, we will address recent advances in redox biology involved in the EMT process in cancer cells, which will contribute to the development of novel therapeutic strategies by targeting redox-regulated EMT for cancer treatment.

10-Gingerol as an inducer of apoptosis through HTR1A in cumulus cells: In-vitro and in-silico studies

Objectives

Cumulus cells play a crucial role as essential mediators in the maturation of ova. Ginger contains 10-gingerol, which induces apoptosis in colon cancer cells. Based on this hypothesis, this study aimed to determine whether 10-gingerol is able to induce apoptosis in normal cells, namely, cumulus cells.

Methods

This study used an in vitro analysis by culturing Cumulus cells in M199 containing 10-gingerol in various concentrations (12, 16, and 20 μM) and later detected early apoptotic activity using an Annexin V-FITC detection kit.

Result

The in vitro data revealed that the number of apoptosis cells increased along with the period of incubation as follows: 12 μM (63.71% ± 2.192%); 16 μM (74.51% ± 4.596%); and 20 μM (78.795% ± 1.435%). The substance 10-gingerol induces apoptosis in cumulus cells by inhibiting HTR1A functions and inactivating GSK3B and AKT-1.

Conclusions

These findings indicate that further examination is warranted for 10-gingerol as a contraception agent.

Therapeutic potential of NADPH oxidase 1/4 inhibitors

The NADPH oxidase (NOX) family of enzymes produces ROS as their sole function and is becoming recognized as key modulators of signal transduction pathways with a physiological role under acute stress and a pathological role after excessive activation under chronic stress. The seven isoforms differ in their regulation, tissue and subcellular localization and ROS products. The most studied are NOX1, 2 and 4. Genetic deletion of NOX1 and 4, in contrast to NOX2, has revealed no significant spontaneous pathologies and a pathogenic relevance of both NOX1 and 4 across multiple organs in a wide range of diseases and in particular inflammatory and fibrotic diseases. This has stimulated interest in NOX inhibitors for therapeutic application. GKT136901 and GKT137831 are two structurally related compounds demonstrating a preferential inhibition of NOX1 and 4 that have suitable properties for in vivo studies and have consequently been evaluated across a range of disease models and compared with gene deletion. In contrast to gene deletion, these inhibitors do not completely suppress ROS production, maintaining some basal level of ROS. Despite this and consistent with most gene deletion studies, these inhibitors are well tolerated and slow or prevent disease progression in a range of models of chronic inflammatory and fibrotic diseases by modulating common signal transduction pathways. Clinical trials in patients with GKT137831 have demonstrated excellent tolerability and reduction of various markers of chronic inflammation. NOX1/4 inhibition may provide a safe and effective therapeutic strategy for a range of inflammatory and fibrotic diseases.

LINKED ARTICLES

This article is part of a themed section on Redox Biology and Oxidative Stress in Health and Disease. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.12/issuetoc.

Metallothioneins regulate the adipogenic differentiation of 3T3-L1 cells via the insulin signaling pathway

Knockout of metallothionein (MT) genes contributes to a heavier body weight in early life and the potential to become obese through the intake of a high fat diet (HFD) in mice. It has thus been suggested that MT genes regulate the formation of adipose tissue, which would become the base for later HFD-induced obesity. We evaluated the fat pads of mice during the lactation stage. The fat mass and adipocyte size of MT1 and MT2 knockout mice were greater than those of wild type mice. Next, we assayed the ability of small interfering RNA (siRNA) to silence MT genes in the 3T3-L1 cell line. The expressions of MT1 and MT2 genes were transiently upregulated during adipocyte differentiation, and the siRNA pretreatment led to the suppression of the expression of both MT mRNAs and proteins. The MT siRNA promoted lipid accumulation in adipocytes and caused proliferation of post-confluent preadipocytes; these effects were suppressed by an inhibitor of phosphatidylinositol 3-kinase (LY294002). In addition, MT siRNA promoted insulin-stimulated phosphorylation of Akt, a downstream kinase of the insulin signaling pathway. Enhanced lipid accumulation in 3T3-L1 cells resulting from MT-gene silencing was inhibited by pretreatment with an antioxidant, N-acetylcysteine, used as a substitute for antioxidant protein MTs. These results suggest that interference in MT expression enhanced the activation of the insulin signaling pathway, resulting in higher lipid accumulation in 3T3-L1 adipocytes.