Thioredoxins in cardiovascular disease

Disulfidptosis decoded: a journey through cell death mysteries, regulatory networks, disease paradigms and future directions

Cell death is an important part of the life cycle, serving as a foundation for both the orderly development and the maintenance of physiological equilibrium within organisms. This process is fundamental, as it eliminates senescent, impaired, or aberrant cells while also promoting tissue regeneration and immunological responses. A novel paradigm of programmed cell death, known as disulfidptosis, has recently emerged in the scientific circle. Disulfidptosis is defined as the accumulation of cystine by cancer cells with high expression of the solute carrier family 7 member 11 (SLC7A11) during glucose starvation. This accumulation causes extensive disulfide linkages between F-actins, resulting in their contraction and subsequent detachment from the cellular membrane, triggering cellular death. The RAC1-WRC axis is involved in this phenomenon. Disulfidptosis sparked growing interest due to its potential applications in a variety of pathologies, particularly oncology, neurodegenerative disorders, and metabolic anomalies. Nonetheless, the complexities of its regulatory pathways remain elusive, and its precise molecular targets have yet to be definitively identified. This manuscript aims to meticulously dissect the historical evolution, molecular underpinnings, regulatory frameworks, and potential implications of disulfidptosis in various disease contexts, illuminating its promise as a groundbreaking therapeutic pathway and target.

Mixture of Doxycycline, ML-7 and L-NAME Restores the Pro- and Antioxidant Balance during Myocardial Infarction-In Vivo Pig Model Study

The restoration of blood flow to the ischemic myocardium inflicts ischemia/reperfusion (I/R) heart injury (IRI). The main contributors to IRI are increased oxidative stress and subsequent excessive production of ROS, increased expression of NOS and peroxinitate, activation of MMPs, and enhanced posttranslational modifications of contractile proteins, which make them more susceptible to proteolytic degradation. Since the pathophysiology of IRI is a complex issue, and thus, various therapeutic strategies are required to prevent or reduce IRI and microvascular dysfunction, in the current study we proposed an innovative multi-drug therapy using low concentrations of drugs applied intracoronary to reach microvessels in order to stabilize the pro- and antioxidant balance during a MI in an in vivo pig model. The ability of a mixture of doxycycline (1 μM), ML-7 (0.5 μM), and L-NAME (2 μM) to modulate the pro- and antioxidative balance was tested in the left ventricle tissue and blood samples. Data showed that infusion of a MIX reduced the total oxidative status (TOS), oxidative stress index (OSI), and malondialdehyde (MDA). It also increased the total antioxidant capacity, confirming its antioxidative properties. MIX administration also reduced the activity of MMP-2 and MMP-9, and then decreased the release of MLC1 and BNP-26 into plasma. This study demonstrated that intracoronary administration of low concentrations of doxycycline in combination with ML-7 and L-NAME is incredibly efficient in regulating pro- and antioxidant balance during MI.

Expanding the Frontiers of Guardian Antioxidant Selenoproteins in Cardiovascular Pathophysiology

Significance: Physiological levels of reactive oxygen and nitrogen species (ROS/RNS) function as fundamental messengers for many cellular and developmental processes in the cardiovascular system. ROS/RNS involved in cardiac redox-signaling originate from diverse sources, and their levels are tightly controlled by key endogenous antioxidant systems that counteract their accumulation. However, dysregulated redox-stress resulting from inefficient removal of ROS/RNS leads to inflammation, mitochondrial dysfunction, and cell death, contributing to the development and progression of cardiovascular disease (CVD). Recent Advances: Basic and clinical studies demonstrate the critical role of selenium (Se) and selenoproteins (unique proteins that incorporate Se into their active site in the form of the 21st proteinogenic amino acid selenocysteine [Sec]), including glutathione peroxidase and thioredoxin reductase, in cardiovascular redox homeostasis, representing a first-line enzymatic antioxidant defense of the heart. Increasing attention has been paid to emerging selenoproteins in the endoplasmic reticulum (ER) (i.e., a multifunctional intracellular organelle whose disruption triggers cardiac inflammation and oxidative stress, leading to multiple CVD), which are crucially involved in redox balance, antioxidant activity, and calcium and ER homeostasis. Critical Issues: This review focuses on endogenous antioxidant strategies with therapeutic potential, particularly selenoproteins, which are very promising but deserve more detailed and clinical studies. Future Directions: The importance of selective selenoproteins in embryonic development and the consequences of their mutations and inborn errors highlight the need to improve knowledge of their biological function in myocardial redox signaling. This could facilitate the development of personalized approaches for the diagnosis, prevention, and treatment of CVD. Antioxid. Redox Signal. 40, 369-432.

CYP-catalysed cycling of clozapine and clozapine-N-oxide promotes the generation of reactive oxygen species in vitro

Clozapine is an effective atypical antipsychotic indicated for treatment-resistant schizophrenia, but is under-prescribed due to the risk of severe adverse drug reactions such as myocarditis.A mechanistic understanding of clozapine cardiotoxicity remains elusive.This study aimed to investigate the contribution of selected CYP isoforms to cycling between clozapine and its major circulating metabolites, N-desmethylclozapine and clozapine-N-oxide, with the potential for reactive species production.CYP supersome™-based in vitro techniques were utilised to quantify specific enzyme activity associated with clozapine, clozapine-N-oxide and N-desmethylclozapine metabolism.The formation of reactive species within each incubation were quantified, and known intermediates detected.CYP3A4 predominately catalysed clozapine-N-oxide formation from clozapine and was associated with concentration-dependent reactive species production, whereas isoforms favouring the N-desmethylclozapine pathway (CYP2C19 and CYP1A2) did not produce reactive species.Extrahepatic isoforms CYP2J2 and CYP1B1 were also associated with the formation of clozapine-N-oxide and N-desmethylclozapine but did not favour one metabolic pathway over another.Unique to this investigation is that various CYP isoforms catalyse clozapine-N-oxide reduction to clozapine.This process was associated with the concentration-dependent formation of reactive species with CYP3A4, CYP1B1 and CYP1A1 that did not correlate with known reactive intermediates, implicating metabolite cycling and reactive oxygen species in the mechanism of clozapine-induced toxicity.

Role of Thioredoxin System in Regulating Cellular Redox Status in Alzheimer's Disease

Alzheimer's disease (AD) is the most common form of dementia and a public health problem. It exhibits significant oxidative stress and redox alterations. The antioxidant enzyme systems defend the cellular environment from oxidative stress. One of the redox systems is the thioredoxin system (TS), which exerts decisive control over the cellular redox environment. We aimed to review the protective effects of TS, which include thioredoxin (Trx), thioredoxin reductase (TrxR), and NADPH. In the following, we discussed the physiological functioning and the role of the TS in maintaining the cellular redox-homeostasis in the AD-damaged brain. Trx protects the cellular environment from oxidative stress, while TrxR is crucial for the cellular detoxification of reactive oxygen species in the brain. However, TS dysregulation increases the susceptibility to cellular death. The changes in Trx and TrxR levels are significantly associated with AD progression. Though the data from human, animal, and cellular models support the neuroprotective role of TS in the brain of AD patients, the translational potential of these findings to clinical settings is not yet applied. This review summarizes the current knowledge on the emerging role of the TrxR-Trx system in AD.

Biosynthesis, Engineering, and Delivery of Selenoproteins

Selenocysteine (Sec) was discovered as the 21st genetically encoded amino acid. In nature, site-directed incorporation of Sec into proteins requires specialized biosynthesis and recoding machinery that evolved distinctly in bacteria compared to archaea and eukaryotes. Many organisms, including higher plants and most fungi, lack the Sec-decoding trait. We review the discovery of Sec and its role in redox enzymes that are essential to human health and important targets in disease. We highlight recent genetic code expansion efforts to engineer site-directed incorporation of Sec in bacteria and yeast. We also review methods to produce selenoproteins with 21 or more amino acids and approaches to delivering recombinant selenoproteins to mammalian cells as new applications for selenoproteins in synthetic biology.

Mitochondrial Impairment: A Link for Inflammatory Responses Activation in the Cardiorenal Syndrome Type 4

Cardiorenal syndrome type 4 (CRS type 4) occurs when chronic kidney disease (CKD) leads to cardiovascular damage, resulting in high morbidity and mortality rates. Mitochondria, vital organelles responsible for essential cellular functions, can become dysfunctional in CKD. This dysfunction can trigger inflammatory responses in distant organs by releasing Damage-associated molecular patterns (DAMPs). These DAMPs are recognized by immune receptors within cells, including Toll-like receptors (TLR) like TLR2, TLR4, and TLR9, the nucleotide-binding domain, leucine-rich-containing family pyrin domain-containing-3 (NLRP3) inflammasome, and the cyclic guanosine monophosphate (cGMP)-adenosine monophosphate (AMP) synthase (cGAS)-stimulator of interferon genes (cGAS-STING) pathway. Activation of these immune receptors leads to the increased expression of cytokines and chemokines. Excessive chemokine stimulation results in the recruitment of inflammatory cells into tissues, causing chronic damage. Experimental studies have demonstrated that chemokines are upregulated in the heart during CKD, contributing to CRS type 4. Conversely, chemokine inhibitors have been shown to reduce chronic inflammation and prevent cardiorenal impairment. However, the molecular connection between mitochondrial DAMPs and inflammatory pathways responsible for chemokine overactivation in CRS type 4 has not been explored. In this review, we delve into mechanistic insights and discuss how various mitochondrial DAMPs released by the kidney during CKD can activate TLRs, NLRP3, and cGAS-STING immune pathways in the heart. This activation leads to the upregulation of chemokines, ultimately culminating in the establishment of CRS type 4. Furthermore, we propose using chemokine inhibitors as potential strategies for preventing CRS type 4.

The Importance of Thioredoxin-1 in Health and Disease

Thioredoxin-1 (Trx-1) is a multifunctional protein ubiquitously found in the human body. Trx-1 plays an important role in various cellular functions such as maintenance of redox homeostasis, proliferation, and DNA synthesis, but also modulation of transcription factors and control of cell death. Thus, Trx-1 is one of the most important proteins for proper cell and organ function. Therefore, modulation of Trx gene expression or modulation of Trx activity by various mechanisms, including post-translational modifications or protein-protein interactions, could cause a transition from the physiological state of cells and organs to various pathologies such as cancer, and neurodegenerative and cardiovascular diseases. In this review, we not only discuss the current knowledge of Trx in health and disease, but also highlight its potential function as a biomarker.

Decreased thioredoxin reductase 3 expression promotes nickel-induced damage to cardiac tissue via activating oxidative stress-induced apoptosis and inflammation

Thioredoxin reductase 3 (Txnrd3) plays a crucial role in antioxidant and anti-cancer activities, and sperm maturation. The damage of heavy metals, including Nickel (Ni), is the most prominent harm in social development, and hampering Txnrd3 might exacerbate Ni-induced cardiac damage. In this study, a total of 160 8-week-old C57BL/N male mice with 25-30 g weight of Txnrd3+/+ wild-type and Txnrd3-/- homozygote-type were randomly divided into eight groups. The mice in the control and Ni groups were gavaged with distilled water and a freshly prepared 10 mg/kg NiCl₂ solution. Melatonin (Mel) groups were administered at a concentration of 2 mg/kg for 21 days at the mice's 0.1 ml/10 g body weight. Ni exposure up-regulated the messenger RNA (mRNA) levels of mitochondrial apoptosis (caspase-3, caspase-9, cytochrome c, p53, and BAX), autophagy (LC3, ATG 1, ATG 7, and Beclin-1), and inflammation (TNF-α, COX 2, IL-1β, IL-2, IL-6, and IL-7)-related markers, but down-regulated the mRNA levels of BCL-2, p62 and mTOR (p < .05). Ni exposure decreased the expression of BCL-2 and p62 protein but increased the expression levels of caspase-3, caspase-9, cytochrome c, p53, BAX, ATG 7, Beclin-1, TNF-α, COX 2, IL-1β and IL-2 protein (p < .05). Ni increased the contents of glutathione disulfide (GSSG) and malondialdehyde (MDA) and decreased the activities of catalase (CAT) and total superoxide dismutase (T-SOD) (p < .05). Decreased Txnrd3 expression significantly exacerbated changes compared to the Ni exposure (p < .05). Mel significantly attenuated these changes, but the effect decreased when Txnrd3 was inhibited (p < .05). In conclusion, decreased Txnrd3 expression promoted Ni-induced mitochondrial apoptosis and inflammation via oxidative stress and aggravated heart damage in mice. Decreased Txnrd3 expression significantly reduced the protective effect of Mel to Ni exposure.

Bifidobacterium animalis A12 and Lactobacillus salivarius M18-6 Alleviate Alcohol Injury by keap1-Nrf2 Pathway and Thioredoxin System

Excessive drinking can significantly damage people's health and well-being. Although some lactic acid bacterial strains have been previously shown to alleviate the symptoms of alcohol injury, the mechanism underlying these effects remains unclear. The aim of this study was to establish an alcohol injury model and examine the protective effect and mechanism of B. animalis A12 and L. salivarius M18-6. The results showed that A12 freeze-dried powder could maintain the survival rate of mice with alcohol injury at 100%. Compared with Alco group, L. salivarius M18-6 dead cell improved the survival rate of mice, attenuated liver steatosis, and significantly down-regulated serum Alanine transaminase (ALT) level; at the same time, it activated keap1-Nrf2 signaling pathway and up-regulated Superoxide dismutase (SOD), it protects mouse liver cells from oxidative stress induced by alcohol injury. In addition, B. animalis A12 can reduce the stress response to short-term alcohol intake and improve the ability of anti-oxidative stress by upregulating the level of isobutyric acid, reducing the level of keap1 protein in the liver of mice and upregulating the expression of thioredoxin genes (Txnrd1, Txnrd3, Txn1). Taken together, the results showed that B. animalis A12 and L. salivarius M18-6 alleviate alcohol injury in mice through keap1-Nrf2 signaling pathway and thioredoxin system.

Biomarkers of Oxidative Stress Tethered to Cardiovascular Diseases

Cardiovascular disease (CVD) is a broad term that incorporated a group of conditions that affect the blood vessels and the heart. CVD is a foremost cause of fatalities around the world. Multiple pathophysiological mechanisms are involved in CVD; however, oxidative stress plays a vital role in generating reactive oxygen species (ROS). Oxidative stress occurs when the concentration of oxidants exceeds the potency of antioxidants within the body while producing reactive nitrogen species (RNS). ROS generated by oxidative stress disrupts cell signaling, DNA damage, lipids, and proteins, thereby resulting in inflammation and apoptosis. Mitochondria is the primary source of ROS production within cells. Increased ROS production reduces nitric oxide (NO) bioavailability, which elevates vasoconstriction within the arteries and contributes to the development of hypertension. ROS production has also been linked to the development of atherosclerotic plaque. Antioxidants can decrease oxidative stress in the body; however, various therapeutic drugs have been designed to treat oxidative stress damage due to CVD. The present review provides a detailed narrative of the oxidative stress and ROS generation with a primary focus on the oxidative stress biomarker and its association with CVD. We have also discussed the complex relationship between inflammation and endothelial dysfunction in CVD as well as oxidative stress-induced obesity in CVD. Finally, we discussed the role of antioxidants in reducing oxidative stress in CVD.

Serum proteomic analysis reveals the cardioprotective effects of Shexiang Baoxin Pill and Suxiao Jiuxin Pill in a rat model of acute myocardial infarction

ETHNOPHARMACOLOGICAL RELEVANCE

Shexiang Baoxin Pill (SBP) and Suxiao Jiuxin Pill (SJP) are traditional Chinese medicines used to treat cardiovascular disease (CVD) in China. However, the mechanism of their therapeutic effect on CVD has not been clearly elucidated yet.

AIMS

The aim of this study is to investigate the cardioprotective effect of SBP and SJP in the treatment of acute myocardial infarction (AMI) model rats by applying serum proteomic approach.

MATERIALS AND METHODS

The rat model of AMI was generated by ligating the left anterior descending coronary artery. 42 rats were randomly divided into four groups: sham-operating (Sham, n = 10) group, model (Mod, n = 8) group, Shexiang Baoxin pills pretreatment (SBP, n = 12) group and Suxiao Jiuxin pills pretreatment (SJP, n = 12) group. Data Independent Acquisition (DIA) proteomic approach was utilized to investigate the serum proteome from the rat individuals. The differentially expressed proteins were subsequently obtained with bioinformatic analysis.

RESULTS

DIA-MS identified 415 proteins within 42 samples, and 84 differentially expressed proteins may contribute to the therapeutic effects of SBP and SJP. GOBP and KEGG pathway analysis of 84 differentially expressed proteins revealed that the proteins were mainly involved in platelet activation and adhesion processes. All 84 differentially expressed proteins presented the same changing tendency in the SBP and SJP groups when compared with the Mod group. Among these 84 proteins, 25 proteins were found to be related to CVD. Among these 25 proteins, ACTB, ACTG1, FGA, FGB, FGG, PF4 and VWF were found to be involved in platelet aggregation and activation. FN1, HSPA5 and YWHAZ were associated with adhesion.

CONCLUSIONS

The results of our study suggest that the cardioprotective effects of SBP and SJP are achieved through the modulation of focal adhesion, platelet activation pathways.

The protective effect of the cardiac thioredoxin system on the heart in the case of iron overload in mice

BACKGROUND

Iron, which is essential for many vital biological processes, causes significant clinical pathologies in the case of its deficiency or excess. Cardiovascular protective pathways are activated by iron therapy. However, determining the appropriate iron concentration is essential to protect heart tissue from iron-induced oxidative stress. The thioredoxin system is one of the antioxidant systems that protect cells against oxidative stress. Moreover, it allows the binding of many transcription factors for apoptosis, myocardial protection, the stimulation of cell proliferation, and angiogenesis processes, especially the regulation of the cardiovascular system. This study's goal was to understand how iron overload affects the gene and protein levels of the thioredoxin system in the mouse heart.

METHODS

BALB/c mice were randomly separated into two groups. The iron overload group was administered with intraperitoneal injections of an iron-dextran solution twice a week for three weeks. In parallel, the control group was intraperitoneally given Dextran 5 solution. The total iron content, the total GSH level, the reduced glutathione/oxidized glutathione (GSH/GSSG) ratio, and thioredoxin reductase 1 (TXNRD1) activity were demonstrated spectroscopically. Changes in the iron metabolism marker genes and thioredoxin system genes were examined by qPCR. The quantitative protein expression of TXNRD1 and thioredoxin-interacting protein (TXNIP) was examined by western blotting.

RESULTS

The iron content of the heart increased in the iron overload group. The expression of hepcidin (Hamp) and ferroportin (Fpn) increased with iron overload. However, decreased expression was observed for ferritin (Fth). No changes were revealed in the GSH level and GSH/GSSG ratio. The gene expression of thioredoxin 1 (Txn1), Txnrd1, and Txnip did not change. TXNRD1 activity and protein expression increased significantly, while the protein expression of TXNIP decreased significantly.

CONCLUSION

In the case of iron overload, the cardiac thioredoxin system is affected by the protein level rather than the gene level. The amount and duration of iron overload used in this study may be considered as a starting point for further studies to determine appropriate conditions for the iron therapy of cardiovascular diseases.

Thioredoxin level and inflammatory markers in children with autism spectrum disorders

Background

Autism Spectrum Disorders (ASD) are a group of neurodevelopmental disabilities with unknown etiology. Recent studies suggest the contribution of immune dysfunction and oxidative stress in its pathophysiology. The present study aimed to investigate the serum level of thioredoxin (Trx), as a marker of oxidative stress and some inflammatory cytokines, and to evaluate their role in children with ASD.

Results

Concentrations of Trx, IL-1β, IL-8, and TNF-α were significantly higher in children with ASD compared with matched controls. There were no association between cytokine levels and the severity of clinical manifestations, according to CARS classification of severity.

Conclusion

The present study provides support for the idea that physiological abnormalities, such as oxidative stress and immune dysfunction, may contribute in the pathophysiology of ASD.

Cardioprotection of pharmacological postconditioning on myocardial ischemia/reperfusion injury

Acute myocardial infarction is associated with high rates of morbidity and mortality and can cause irreversible myocardial damage. Timely reperfusion is critical to limit infarct size and salvage the ischemic myocardium. However, reperfusion may exacerbate lethal tissue injury, a phenomenon known as myocardial ischemia/reperfusion (I/R) injury. Pharmacological postconditioning (PPC), a strategy involving medication administration before or during the early minutes of reperfusion, is more efficient and flexible than preconditioning or ischemic conditioning. Previous studies have shown that various mechanisms are involved in the effects of PPC. In this review, we summarize the relative effects and potential underlying mechanisms of PPC to provide a foundation for future research attempting to develop novel treatments against myocardial I/R injury.

Inhibition of thioredoxin 2 by intracellular methylglyoxal accumulation leads to mitochondrial dysfunction and apoptosis in INS-1 cells

PURPOSE

To investigate the role of thioredoxin 2 (Trx2) inhibition induced by intracellular methylglyoxal (MGO) in pancreatic beta-cell mitochondrial dysfunction and apoptosis.

METHODS

Rat pancreatic beta-cell line INS-1 cells were treated with Glo1 siRNAs or exogenous MGO to increase intracellular MGO. AGEs formation was detected by ELISA and mitochondrial ROS was detected by probe MitoSOX. Transmission electron microscopy (TEM) analysis and ATP content were measured to evaluate mitochondrial function. Trx2 expression was manipulated by overexpression with recombinant Trx2 lentivirus or knockdown with Trx2 siRNAs, and effects on apoptosis and insulin secretion were measured by flow cytometry and ELISA, respectively.

RESULTS

The increase of intracellular MGO by Glo1 blockage or MGO treatment led to advanced glycation end products (AGEs) overproduction, mitochondrial ROS increase, and insulin secretion paralysis. These were probably due to MGO-induced inhibition of mitochondrial Trx2. Trx2 inhibition by blockage of either Glo1 or Trx2 impaired mitochondrial integrity, inhibited cytochrome C oxidases subunit 1 and 4 (Cox1 and Cox4) expression and further reduced ATP generation, and all of these might lead to insulin paralysis; whereas Trx2 overexpression partially reversed MGO-induced oxidative stress, attenuated insulin secretion by preventing mitochondrial damage. Trx2 overexpression also retarded MGO-induced apoptosis of INS-1 cell through inhibiting ASK1 activation and downregulation of the ASK1-p38 MAPK pathway.

CONCLUSIONS

Our results reveal a possible mechanism for beta-cell oxidative damage upon intracellular MGO-induced Trx2 inactivation and mitochondrial dysfunction and apoptosis.

Synthesis and biological evaluation of myricetin-pentadienone hybrids as potential anti-inflammatory agents in vitro and in vivo

Some important pro-inflammatory cytokines such as interleukin-6, tumor necrosis factor-α and nitric oxide are thought to play key roles in the destruction of cartilage and bone tissue in joints affected by rheumatoid arthritis. In the present study, a series of new myricetin-pentadienone hybrids were designed and synthesized. Majority of them effectively inhibited the expressions liposaccharide-induced secretion of IL-6, TNF-α and NO in RAW264.7. The most prominent compound 5o could significantly decrease production of above inflammatory factors with IC₅₀ values of 5.22 µM, 8.22 µM and 9.31 µM, respectively. Preliminary mechanism studies indicated that it could inhibit the expression of thioredoxin reductase, resulting in inhibiting of cell signaling pathway nuclear factor (N-κB) and mitogen-activated protein kinases. Significantly, compound 5o was found to effectively inhibit Freund's complete adjuvant induced rat adjuvant arthritis in vivo.

Thioredoxin1 Inactivation Mediates the Impairment of Ischemia-Induced Angiogenesis and Further Injury in Diabetic Myocardium

Diabetes mellitus (DM)-induced impairment of collateral formation has been demonstrated in subjects with coronary artery disease, which contributes to unfavorable prognosis among diabetic individuals. In our previous studies, thioredoxin1 (Trx1) activity was shown to be decreased in diabetic cardiac tissues, but the reason of Trx1 inactivation and whether it mediates the impaired angiogenesis in ischemic myocardium is still to be identified. As thioredoxin-interacting protein (TXNIP), an endogenous inhibitor of Trx, is overexpressed in DM due to carbohydrate response element within its promoter, we hypothesized that inhibition of Trx1 by enhanced TXNIP expression in endothelial cells may play a role in hyperglycemia-induced impairment of angiogenesis. In the present study, we found that high glucose-mediated increase of TXNIP expression and TXNIP-Trx1 interaction induced the impairment in endothelial cell function and survival, since these detrimental effects are rescued by silencing TXNIP with small interfering RNA. In diabetic mice, TXNIP knockdown or recombinant human Trx1 treatment counteracted the impairment of angiogenesis, alleviated myocardial ischemic injury, and improved survival rate. All these data implicate that TXNIP upregulation and subsequently the increased formation of TXNIP-Trx1 complex is a novel pathologic pathway by which DM induces insufficient angiogenesis and thereby exacerbates myocardial ischemia injury.

Engineered Nanoparticles for Effective Redox Signaling During Angiogenic and Antiangiogenic Therapy

SIGNIFICANCE

Redox signaling plays a vital role in regulating various cellular signaling pathways and disease biology. Recently, nanomedicine (application of nanotechnology in biology and medicine) has been demonstrated to regulate angiogenesis through redox signaling. A complete understanding of redox signaling pathways influenced angiogenesis/antiangiogenesis triggered by therapeutic nanoparticles is extensively reviewed in this article. Recent Advances: In recent times, nanomedicines are regarded as the Trojan horses that could be employed for successful drug delivery, gene delivery, peptide delivery, disease diagnosis, and others, conquering barriers associated with conventional theranostic approaches.

CRITICAL ISSUES

Physiological angiogenesis is a tightly regulated process maintaining a balance between proangiogenic and antiangiogenic factors. The redox signaling is one of the main factors that contribute to this physiological balance. An aberrant redox signaling cascade can be caused by several exogenous and endogenous factors and leads to reduced or augmented angiogenesis that ultimately results in several disease conditions.

FUTURE DIRECTIONS

Redox signaling-based nanomedicine approach has emerged as a new platform for angiogenesis-related disease therapy, where nanoparticles promote angiogenesis via controlled reactive oxygen species (ROS) production and antiangiogenesis by triggering excessive ROS formation. Recently, investigators have identified different efficient nano-candidates, which modulate angiogenesis by controlling intracellular redox molecules. Considering the importance of angiogenesis in health care a thorough understanding of nanomedicine-regulated redox signaling would inspire researchers to design and develop more novel nanomaterials that could be used as an alternative strategy for the treatment of various diseases, where angiogenesis plays a vital role.

Scope of organometallic compounds based on transition metal-arene systems as anticancer agents: starting from the classical paradigm to targeting multiple strategies

The advent of the clinically approved drug cisplatin started a new era in the design of metallodrugs for cancer chemotherapy. However, to date, there has not been much success in this field due to the persistence of some side effects and multi-drug resistance of cancer cells. In recent years, there has been increasing interest in the design of metal chemotherapeutics using organometallic complexes due to their good stability and unique properties in comparison to normal coordination complexes. Their intermediate properties between that of traditional inorganic and organic materials provide researchers with a new platform for the development of more promising cancer therapeutics. Classical metal-based drugs exert their therapeutic potential by targeting only DNA, but in the case of organometallic complexes, their molecular target is quite distinct to avoid drug resistance by cancer cells. Some organometallic drugs act by targeting a protein or inhibition of enzymes such as thioredoxin reductase (TrRx), while some target mitochondria and endoplasmic reticulum. In this review, we mainly discuss organometallic complexes of Ru, Ti, Au, Fe and Os and their mechanisms of action and how new approaches improve their therapeutic potential towards various cancer phenotypes. Herein, we discuss the role of structure-reactivity relationships in enhancing the anticancer potential of drugs for the benefit of humans both in vitro and in vivo. Besides, we also include in vivo tumor models that mimic human physiology to accelerate the development of more efficient clinical organometallic chemotherapeutics.

Molecular Mechanisms of Glucose Fluctuations on Diabetic Complications

Accumulating evidence indicates the occurrence and development of diabetic complications relates to not only constant high plasma glucose, but also glucose fluctuations which affect various kinds of molecular mechanisms in various target cells and tissues. In this review, we detail reactive oxygen species and their potentially damaging effects upon glucose fluctuations and resultant downstream regulation of protein signaling pathways, including protein kinase C, protein kinase B, nuclear factor-κB, and the mitogen-activated protein kinase signaling pathway. A deeper understanding of glucose-fluctuation-related molecular mechanisms in the development of diabetic complications may enable more potential target therapies in future.

N-acetylcysteine alleviates H2O2-induced damage via regulating the redox status of intracellular antioxidants in H9c2 cells

N-acetylcysteine (NAC) is a thiol-containing antioxidant that modulates the intracellular redox state. NAC can scavenge reactive oxygen species (ROS) and maintain reduced glutathione (GSH) levels, in order to protect cardiomyocytes from oxidative stress. The present study aimed to determine whether NAC protects cardiomyocytes from oxidative damage by regulating the redox status of intracellular antioxidant proteins. The results revealed that NAC pretreatment increased cell viability and inhibited the activation of caspase-3, -8 and -9 during hydrogen peroxide (H₂O₂)-induced oxidative stress in H9c2 cells. Furthermore, decreased ROS levels, and increased total and reduced GSH levels were detected in response to NAC pretreatment. Non-reducing redox western blotting was performed to detect the redox status of intracellular antioxidant proteins, including thioredoxin 1 (Trx1), peroxiredoxin 1 (Prx1), GSH reductase (GSR), and phosphatase and tensin homolog (PTEN). The results revealed that the reduced form of Trx1 was markedly increased, and the oxidized forms of Prx1, GSR and PTEN were decreased following NAC pretreatment. Furthermore, NAC pretreatment decreased H₂O₂-induced phosphorylation of apoptosis signal-regulating kinase 1, which depends on the redox state of Trx1, and increased H₂O₂-induced phosphorylation of protein kinase B, which is essential to cell survival. To the best of our knowledge, the present study is the first to reveal that NAC pretreatment may alleviate oxidation of intracellular antioxidant proteins to inhibit oxidative stress-induced cardiomyocyte apoptosis.

The Effect of Long-Term Administration of Fatty Acid Amide Hydrolase Inhibitor URB597 on Oxidative Metabolism in the Heart of Rats with Primary and Secondary Hypertension

Fatty acid amide hydrolase (FAAH) inhibitor [3-(3-carbamoylphenyl)phenyl] N-cyclohexylcarbamate (URB597) may influence redox balance and blood pressure through the modulation of endocannabinoids levels. Therefore, this study aimed to compare changes in oxidative metabolism and apoptosis in the hearts of rats with spontaneous hypertension (SHR) and secondary hypertension (11-deoxycorticosterone acetate; DOCA-salt rats) treated by URB597 via intraperitoneal injection for 14 days. The results showed that URB597 decreased the activity of NADPH and xanthine oxidases in both groups of rats. Moreover, in the heart of SHR rats, URB597 led to an increase of enzymatic and nonenzymatic antioxidant activity and levels (catalase, vitamin C, glutathione/glutathione disulfide [GSH/GSSG]) and upregulation of the thioredoxin system; however, NRf2 expression was downregulated. The opposite effect in relation to Nrf2 activity and the thioredoxin system was observed in DOCA-salt rats after URB597 administration. Despite improvement in antioxidant parameters, URB597 enhanced oxidative modifications of phospholipids (4-hydroxynonenal and isoprostanes) and proteins (carbonyl groups) in SHR heart, whereas 4-hydroxynonenal and carbonyl groups levels decreased in the heart of DOCA-salt rats. Obtained results suggest that examined lipid mediators are involved in peroxisome proliferator-activated receptors (PPAR)-independent and PPAR-dependent modulation of cardiac inflammatory reactions. Furthermore, decreased expression of pro-apoptotic proteins (Bax and caspase 3 and 9) was observed after URB597 administration in the heart of both groups of hypertensive rats, whereas expression of the antiapoptotic protein (Bcl-2) increased in SHR rats. Long-term administration of URB597 altered cardiac redox status depending on the type of hypertension. URB597 enhanced oxidative metabolism and reduced pro-apoptotic factors in the heart of SHR rats, increasing the probability of heart metabolic disorders occurrence or progression.

Expression of MyoD, insulin like growth factor binding protein, thioredoxin and p27 in secondarily overacting inferior oblique muscles with superior oblique palsy

Backgound

To identify and compare specific protein levels between overacting inferior oblique (IO) muscles in superior oblique (SO) palsy patients and normal IO muscles.

Methods

We obtained 20 IO muscle samples from SO palsy patients with IO overaction ≥ + 3 who underwent IO myectomies (IOOA group), and 20 IO samples from brain death donors whose IO had functioned normally, according to their ophthalmological chart review (control group). We used MyoD for identifying satellite cell activation, insulin-like growth factor binding protein 5 (IGFBP5) for IGF effects, thioredoxin for oxidative stress, and p27 for satellite cell activation or oxidative stress in both groups. Using immunohistochemistry and Western blot, we compared expression levels of the four proteins (MyoD, IGFBP5, thioredoxin, and p27).

Results

Levels of thioredoxin and p27 were decreased significantly in the IOOA group. MyoD and IGFBP5 levels showed no significant difference between the groups.

Conclusions

Based on these findings, the overacting IOs of patients with SO palsy had been under oxidative stress status versus normal IOs. Pathologically overacting extraocular muscles may have an increased risk of oxidative stress compared with normal extraocular muscles.

The lipid peroxidation product 4-hydroxy-2-nonenal induces tissue factor decryption via ROS generation and the thioredoxin system

Many pathophysiologic agents transform cryptic tissue factor (TF) on cells to prothrombotic TF, and one such stimulus is 4-hydroxy-2-nonenal (HNE), the most abundant aldehyde produced by the oxidation of ω-6 polyunsaturated fatty acids. HNE was shown to induce reactive oxygen species (ROS) generation and p38 MAPK activation, but the link between them and their role in TF decryption are unclear. The present study was carried out to elucidate potential mechanisms involved in HNE-induced TF decryption in monocytic cells. The data presented herein show that mitochondria are the primary source for HNE-induced ROS generation. The inhibition of mitochondrial electron transport chain complex III and V blocked HNE-induced ROS generation, but not p38 MAPK activation. These inhibitors reduced phosphatidylserine (PS) externalization and TF decryption significantly, but not completely. HNE treatment inhibited the activities of thioredoxin reductase (TrxR) and thioredoxin (Trx), independent of ROS. Inhibition of the TrxR/Trx system by HNE or pharmacological inhibitors induced p38 MAPK activation, PS externalization, and TF decryption. Additional studies revealed that the inhibition of TrxR/Trx led to activation of apoptosis signal-regulating kinase (ASK-1) and mitogen-activated protein kinase kinase 3/6. Inhibition of ASK-1 expression by small interfering RNA or its activity by pharmacological inhibitors diminished HNE-induced TF decryption. Overall, our data suggest that HNE induces TF decryption by 2 distinctive pathways. One is ROS dependent but independent of p38 MAPK activation, and the other is via TrxR/Trx and is p38 MAPK activation dependent. However, both mechanisms result in the enhancement of PS at the outer leaflet that is responsible for TF decryption.

Analysis of the Interactions Between Thioredoxin and 20 Selenoproteins in Chicken

Thioredoxin (Trx) is a small molecular protein with complicated functions in a number of processes, including inflammation, apoptosis, embryogenesis, cardiovascular disease, and redox regulation. Some selenoproteins, such as glutathione peroxidase (Gpx), iodothyronine deiodinase (Dio), and thioredoxin reductase (TR), are involved in redox regulation. However, whether there are interactions between Trx and selenoproteins is still not known. In the present paper, we used a Modeller, Hex 8.0.0, and the KFC2 Server to predict the interactions between Trx and selenoproteins. We used the Modeller to predict the target protein in objective format and assess the accuracy of the results. Molecular interaction studies with Trx and selenoproteins were performed using the molecular docking tools in Hex 8.0.0. Next, we used the KFC2 Server to further test the protein binding sites. In addition to the selenoprotein physiological functions, we also explored potential relationships between Trx and selenoproteins beyond all the results we got. The results demonstrate that Trx has the potential to interact with 19 selenoproteins, including iodothyronine deiodinase 1 (Dio1), iodothyronine deiodinase 3 (Dio3), glutathione peroxidase 1 (Gpx1), glutathione peroxidase 2 (Gpx2), glutathione peroxidase 3 (Gpx3), glutathione peroxidase 4 (Gpx4), selenoprotein H (SelH), selenoprotein I (SelI), selenoprotein M (SelM), selenoprotein N (SelN), selenoprotein T (SelT), selenoprotein U (SelU), selenoprotein W (SelW), selenoprotein 15 (Sep15), methionine sulfoxide reductase B (Sepx1), selenophosphate synthetase 1 (SPS1), TR1, TR2, and TR3, among which TR1, TR2, TR3, SPS1, Sep15, SelN, SelM, SelI, Gpx2, Gpx3, Gpx4, and Dio3 exhibited intense correlations with Trx. However, additional experiments are needed to verify them.

Dihydromyricetin attenuated Ang II induced cardiac fibroblasts proliferation related to inhibitory of oxidative stress

Dihydromyricetin (DMY) is one of the most important flavonoids in vine tea, which showed several pharmacological effects. However, information about the potential role of DMY on angiotensin II (Ang II) induced cardiac fibroblasts proliferation remains unknown. In the present study, cardiac fibroblasts isolated from neonatal Sprague-Dawley rats were pretreated with different concentrations of DMY (0-320μM) for 4h, or DMY (80μM) for different time (0-24h), followed by Ang II (100nM) stimulation for 24h, Then number of cardiac fibroblasts and content of hydroxyproline was measured. The level of cellular reactive oxygen species, malondialdehyde (MDA), activity of superoxide dismutase (SOD) and total antioxidant capacity (T-AOC) were also evaluated. Expression of type I, type III collagen, α-smooth muscle actin (α-SMA), p22^phox (one vital subunit of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase), SOD and thioredoxin (Trx) were detected with real time PCR or/and western blot. We found that pre-incubation with DMY (20μM, 40μM, 80μM) for 4h, 12h or 24h attenuated the proliferation of cardiac fibroblasts induced by Ang II. Expression of type I and type III collagen, as well as α-SMA were inhibited by DMY at both mRNA and protein level. DMY also significantly decreased cellular reactive oxygen species production and MDA level, while increased the SOD activity and T-AOC. DMY suppressed p22^phox, while enhanced antioxidant SOD and Trx expression in Ang II stimulated cardiac fibroblasts. Thus, dihydromyricetin attenuated Ang II induced cardiac fibroblasts proliferation related to inhibitory of oxidative stress.