The role of the antioxidant and longevity-promoting Nrf2 pathway in metabolic regulation

Bombesin protects myocardium against ischemia/reperfusion injury via activation of the Keap1-Nrf2-HO-1 signaling pathway

AIMS

It has been reported that some peptides released by the gastro-intestinal tract play important roles in the prevention of myocardial ischemia/reperfusion injury (MIRI). Bombesin (BN) is a biologically active peptide released by non-adrenergic non-cholinergic nerves on the gastric antrum mucosa controlled by the vagus nerve. However, there is a lack of reports on the impact of BN on MIRI. This study aimed to explore the influence of BN on MIRI and its underlying mechanism.

MATERIALS AND METHODS

MIRI was induced by either 30 min of global ischemia in Langendorff perfused rat hearts, or by ligation of the descending coronary artery for 30 min in anesthetized Spraque-Dawley rats, and both were followed by 120 min reperfusion. Infarct size and left ventricular function were assessed, and lactate dehydrogenase (LDH), superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione (GSH) levels were measured spectrophotometrically, while cardiomyocyte apoptosis was detected by TUNEL assay. The content of BN in plasma was measured with enzyme-linked immunosorbent assays (ELISA). The expression of caspase 3, Kelch-like ECH-associated protein 1 (Keap1), nuclear factor erythroid 2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1) were quantified.

KEY FINDINGS

BN and vagus nerve stimulation improved cardiac contractile function and reduced myocardial infarct size, attenuated oxidative stress damage and myocardial cell apoptosis, increased the expression of Keap1, Nrf2, and HO-1. and these effects were blocked by using a BN receptor antagonist.

SIGNIFICANCE

BN provides protection against MIRI, and its underlying mechanism is through activation of the Keap1/Nrf2/HO-1 pathway. This research provides more reliable evidence for the "gut-heart axis dialogue" and explores potential therapeutic approaches for MIRI.

The Roles of White Adipose Tissue and Liver NADPH in Dietary Restriction-Induced Longevity

Dietary restriction (DR) protocols frequently employ intermittent fasting. Following a period of fasting, meal consumption increases lipogenic gene expression, including that of NADPH-generating enzymes that fuel lipogenesis in white adipose tissue (WAT) through the induction of transcriptional regulators SREBP-1c and CHREBP. SREBP-1c knockout mice, unlike controls, did not show an extended lifespan on the DR diet. WAT cytoplasmic NADPH is generated by both malic enzyme 1 (ME1) and the pentose phosphate pathway (PPP), while liver cytoplasmic NADPH is primarily synthesized by folate cycle enzymes provided one-carbon units through serine catabolism. During the daily fasting period of the DR diet, fatty acids are released from WAT and are transported to peripheral tissues, where they are used for beta-oxidation and for phospholipid and lipid droplet synthesis, where monounsaturated fatty acids (MUFAs) may activate Nrf1 and inhibit ferroptosis to promote longevity. Decreased WAT NADPH from PPP gene knockout stimulated the browning of WAT and protected from a high-fat diet, while high levels of NADPH-generating enzymes in WAT and macrophages are linked to obesity. But oscillations in WAT [NADPH]/[NADP+] from feeding and fasting cycles may play an important role in maintaining metabolic plasticity to drive longevity. Studies measuring the WAT malate/pyruvate as a proxy for the cytoplasmic [NADPH]/[NADP+], as well as studies using fluorescent biosensors expressed in the WAT of animal models to monitor the changes in cytoplasmic [NADPH]/[NADP+], are needed during ad libitum and DR diets to determine the changes that are associated with longevity.

The Application of Resveratrol Derivatives in Oral Cells Reduces the Oxidative Stress Induced by Glucocorticoids

Oxidative stress and high levels of reactive oxygen species (ROS) are linked to various age-related diseases and chronic conditions, including damage to oral tissues. Dexamethasone (DEX), a widely used glucocorticoid in dentistry, can have side effects like increased ROS production and delayed wound healing. Resveratrol (RSV) is known for its antioxidant properties, but its limited bioavailability hinders its clinical use. This study investigated the potential of two RSV derivatives (1d and 1h) to address these limitations. The antioxidant abilities of 1d and 1h (5 μM) against DEX-induced oxidative stress (200 μM) were evaluated in human gingival fibroblasts (hGFs) and osteoblasts (hOBs). The effects of these compounds on cell viability, morphology, ROS levels, SOD activity, gene expression, and collagen production were evaluated. RSV derivatives, under DEX-induced oxidative stress condition, improved cell growth at 72 h (191.70 ± 10.92% for 1d+DEX and 184.80 ± 13.87% for 1h+DEX), morphology, and SOD activity (77.33 ± 3.35 OD for 1d+DEX; 76.87 ± 3.59 OD for 1h+DEX at 1 h), while reducing ROS levels (2417.33 ± 345.49 RFU for 1d+DEX and 1843.00 ± 98.53 RFU at 4 h), especially in hOBs. The co-treatment of RSV or derivatives with DEX restored the expression of genes that were downregulated by DEX, such as HO-1 (1.76 ± 0.05 for 1d+DEX and 1.79 ± 0.01 for 1h+DEX), CAT (0.97 ± 0.06 for 1d+DEX and 0.99 ± 0.03 for 1h+DEX), NRF2 (1.62 ± 0.04 for 1d+DEX and 1.91 ± 0.05 for 1h+DEX), SOD1 (1.63 ± 0.15 for 1d+DEX and 1.69 ± 0.04 for 1h+DEX). In addition, 1d and 1h preserved collagen production (111.79 ± 1.56 for 1d+DEX and 122.27 ± 1.56 for 1h+DEX). In conclusion, this study suggests that the RSV derivatives 1d and 1h hold promise as potential antioxidant agents to counteract DEX-induced oxidative stress. These findings contribute to the development of novel therapeutic strategies for managing oxidative stress-related oral conditions.

Azilsartan Attenuates 3-Nitropropinoic Acid-Induced Neurotoxicity in Rats: The Role of IĸB/NF-ĸB and KEAP1/Nrf2 Signaling Pathways

Huntington's disease (HD) is an autosomal-dominant neurodegenerative disorder characterized by motor, psychiatric and cognitive symptoms. Injection of 3-nitropropionic acid (3-NP) is a widely used experimental model for induction of HD. The current study aimed to inspect the potential neuroprotective properties of azilsartan (Azil), an angiotensin II type 1 receptor blocker (ATR1), in 3-NP-induced striatal neurotoxicity in rats. Rats were randomly allocated into five groups and treated for 14 days as follows: group I received normal saline; group II received Azil (10 mg/kg, p.o.); group III received 3-NP (10 mg/kg, i.p); group IV and V received Azil (5 or 10 mg/kg, p.o, respectively) 1 h prior to 3-NP injection. Both doses of Azil markedly attenuated motor and behavioural dysfunction as well as striatal histopathological alterations caused by 3-NP. In addition, Azil balanced striatal neurotransmitters levels as evidenced by the increase of striatal gamma-aminobutyric acid content and the decrease of glutamate content. Azil also amended neuroinflammation and oxidative stress via modulating IĸB/NF-ĸB and KEAP1/Nrf2 downstream signalling pathways, as well as reducing iNOS and COX2 levels. Moreover, Azil demonstrated an anti-apoptotic activity by reducing caspase-3 level and BAX/BCL2 ratio. In conclusion, the present study reveals the neuroprotective potential of Azil in 3-NP-induced behavioural, histopathological and biochemical changes in rats. These findings might be attributed to inhibition of ATR1/NF-κB signalling, modulation of Nrf2/KEAP1 signalling, anti-inflammatory, anti-oxidant and anti-apoptotic properties.

Disrupting the SKN-1 homeostat: mechanistic insights and phenotypic outcomes

The mechanisms that govern maintenance of cellular homeostasis are crucial to the lifespan and healthspan of all living systems. As an organism ages, there is a gradual decline in cellular homeostasis that leads to senescence and death. As an organism lives into advanced age, the cells within will attempt to abate age-related decline by enhancing the activity of cellular stress pathways. The regulation of cellular stress responses by transcription factors SKN-1/Nrf2 is a well characterized pathway in which cellular stress, particularly xenobiotic stress, is abated by SKN-1/Nrf2-mediated transcriptional activation of the Phase II detoxification pathway. However, SKN-1/Nrf2 also regulates a multitude of other processes including development, pathogenic stress responses, proteostasis, and lipid metabolism. While this process is typically tightly regulated, constitutive activation of SKN-1/Nrf2 is detrimental to organismal health, this raises interesting questions surrounding the tradeoff between SKN-1/Nrf2 cryoprotection and cellular health and the ability of cells to deactivate stress response pathways post stress. Recent work has determined that transcriptional programs of SKN-1 can be redirected or suppressed to abate negative health outcomes of constitutive activation. Here we will detail the mechanisms by which SKN-1 is controlled, which are important for our understanding of SKN-1/Nrf2 cytoprotection across the lifespan.

Structural Analysis and Antioxidant and Immunoregulatory Activities of an Exopolysaccharide Isolated from Bifidobacterium longum subsp. longum XZ01

Bifidobacterium longum subsp. longum XZ01 (BLSL1) is a new strain (isolated from the intestines of healthy people and deposited with the preservation number GDMCC 61618). An exopolysaccharide, S-EPS-1, was successfully isolated from the strain and then systematically investigated for the first time. Some structural features of S-EPS-1 were analyzed by chemical component, HPLC, ultraviolet, infrared, and nuclear magnetic resonance spectrum analyses. These analyses revealed that S-EPS-1 is a neutral heteropolysaccharide with an α-configuration. It contains mainly mannose and glucose, as well as small amounts of rhamnose and galactose. The molecular weight of S-EPS-1 was calculated to be 638 kDa. Several immunoregulatory activity assays indicated that S-EPS-1 could increase proliferation, phagocytosis, and NO production in vitro. In addition, S-EPS-1 could upregulate the expression of cytokines at the mRNA level through TLR4-mediated activation of the NF-κB signaling pathway in RAW 264.7 cells. Finally, S-EPS-1 was demonstrated to exhibit antioxidant activity by ABTS+• scavenging, DPPH• scavenging, and ferric-ion reducing power assays. Furthermore, S-EPS-1 can protect cells from oxidative stress and shows no cytotoxicity. These beneficial effects can be partly attributed to its antioxidant ability. Thus, the antioxidant S-EPS-1 may be applied as a functional food in the future.

Unraveling the Nrf2-ARE Signaling Pathway in the DF-1 Chicken Fibroblast Cell Line: Insights into T-2 Toxin-Induced Oxidative Stress Regulation

The T-2 toxin (T2) poses a major threat to the health and productivity of animals. The present study aimed to investigate the regulatory mechanism of Nrf2 derived from broilers against T2-induced oxidative damage. DF-1 cells, including those with normal characteristics, as well as those overexpressing or with a knockout of specific components, were exposed to a 24 h treatment of 50 nM T2. The primary objective was to evaluate the indicators associated with oxidative stress and the expression of downstream antioxidant factors regulated by the Nrf2-ARE signaling pathway, at both the mRNA and protein levels. The findings of this study demonstrated a noteworthy relationship between the up-regulation of the Nrf2 protein and a considerable reduction in the oxidative stress levels within DF-1 cells (p < 0.05). Furthermore, this up-regulation was associated with a notable increase in the mRNA and protein levels of antioxidant factors downstream of the Nrf2-ARE signaling pathway (p < 0.05). Conversely, the down-regulation of the Nrf2 protein was linked to a marked elevation in oxidative stress levels in DF-1 cells (p < 0.05). Additionally, this down-regulation resulted in a significant decrease in both the mRNA and protein expression of antioxidant factors (p < 0.05). This experiment lays a theoretical foundation for investigating the detrimental impacts of T2 on broiler chickens. It also establishes a research framework for employing the Nrf2 protein in broiler chicken production and breeding. Moreover, it introduces novel insights for the prospective management of oxidative stress-related ailments in the livestock and poultry industry.

Molecular mechanism of caloric restriction mimetics-mediated neuroprotection of age-related neurodegenerative diseases: an emerging therapeutic approach

Aging-induced neurodegenerative diseases (NDs) are significantly increasing health problem worldwide. It has been well documented that oxidative stress is one of the potential causes of aging and age-related NDs. There are no drugs for the treatment of NDs, therefore there is an immediate necessity for the development of strategies/treatments either to prevent or cure age-related NDs. Caloric restriction (CR) and intermittent fasting have been considered as effective strategies in increasing the healthspan and lifespan, but it is difficult to adhere to these routines strictly, which has led to the development of calorie restriction mimetics (CRMs). CRMs are natural compounds that provide similar molecular and biochemical effects of CR, and activate autophagy process. CRMs have been reported to regulate redox signaling by enhancing the antioxidant defense systems through activation of the Nrf2 pathway, and inhibiting ROS generation through attenuation of mitochondrial dysfunction. Moreover, CRMs also regulate redox-sensitive signaling pathways such as the PI3K/Akt and MAPK pathways to promote neuronal cell survival. Here, we discuss the neuroprotective effects of various CRMs at molecular and cellular levels during aging of the brain. The CRMs are envisaged to become a cornerstone of the pharmaceutical arsenal against aging and age-related pathologies.

The Molecular Mechanism of Polyphenols in the Regulation of Ageing Hallmarks

Ageing is a complex process characterized mainly by a decline in the function of cells, tissues, and organs, resulting in an increased risk of mortality. This process involves several changes, described as hallmarks of ageing, which include genomic instability, telomere attrition, epigenetic changes, loss of proteostasis, dysregulated nutrient sensing, mitochondrial dysfunction, cellular senescence, stem cell depletion, and altered intracellular communication. The determining role that environmental factors such as diet and lifestyle play on health, life expectancy, and susceptibility to diseases, including cancer and neurodegenerative diseases, is wellestablished. In view of the growing interest in the beneficial effects of phytochemicals in the prevention of chronic diseases, several studies have been conducted, and they strongly suggest that the intake of dietary polyphenols may bring numerous benefits due to their antioxidant and anti-inflammatory properties, and their intake has been associated with impaired ageing in humans. Polyphenol intake has been shown to be effective in ameliorating several age-related phenotypes, including oxidative stress, inflammatory processes, impaired proteostasis, and cellular senescence, among other features, which contribute to an increased risk of ageing-associated diseases. This review aims to address, in a general way, the main findings described in the literature about the benefits of polyphenols in each of the hallmarks of ageing, as well as the main regulatory mechanisms responsible for the observed antiageing effects.

The Protective Role of Nrf2 in Renal Tubular Cells in Oxidised Low-Density Lipoprotein-Induced Fibrosis

Background: CD36 is the receptor of oxidised low-density lipoprotein (OxLDL) in renal tubular epithelial cells. Nuclear factor erythroid 2-related factor 2 (Nrf2) is the key factor in the activation of the Nrf2 signalling pathway and the regulation of oxidative stress. Kelch-like ECH-associated protein 1 (Keap1) is known as an Nrf2 inhibitor. Methods: We used OxLDL and Nrf2 inhibitors at different concentrations and durations to treat renal tubular epithelial cells; the expression of CD36 and cytoplasmic and nucleic Nrf2 and E-cadherin in those cells were observed by Western blot and reverse-transcription polymerase chain reaction. Results: The protein levels of Nrf2 decreased in expression after 24 hours of OxLDL treatment. At the same time, the Nrf2 protein level in the cytoplasm did not change significantly compared with that of the control group, and the Nrf2 protein level expression in the nucleus increased. Both the messenger ribonucleic acid (mRNA) and protein expression of CD36 decreased following the treatment of cells with the Nrf2 inhibitor Keap1. Kelch-like ECH-associated protein 1 was overexpressed, and CD36 mRNA and protein expression were decreased in OxLDL-treated cells. Following the overexpression of Keap1, E-cadherin expression was reduced in NRK-52E cells. Conclusion: Nuclear factor erythroid 2-related factor 2 can be activated by OxLDL; however, it can only alleviate OxLDL-induced oxidative stress by transferring from the cytoplasm to the nucleus. Additionally, Nrf2 may play a protective role by upregulating CD36.

Depleted uranium causes renal mitochondrial dysfunction through the ETHE1/Nrf2 pathway

The kidney is the main organ affected by acute depleted uranium (DU) toxicity. The mechanism of nephrotoxicity induced by DU is complex and needs to be further explored. This study aimed to elucidate the function of mitochondrial dysfunction in nephrotoxicity generated by DU and confirm the latent mechanism. We verified that DU (2.5-10 mg/kg) caused mitochondrial dysfunction in male rat kidneys and decreased ATP content and the mitochondrial membrane potential. In addition, melatonin (20 mg/kg), as an antioxidant, alleviated DU-induced oxidative stress and mitochondrial dysfunction in male rats, further reducing kidney damage caused by DU. These results indicate that mitochondrial dysfunction plays a vital role in DU nephrotoxicity. When ethylmalonic encephalopathy 1 (ETHE1) was knocked down, DU-induced oxidative stress and mitochondrial dysfunction were increased, and renal injury was aggravated. When exogenous ETHE1 protein was applied to renal cells, the opposite changes were observed. We also found that ETHE1 knockdown increased the expression of NF-E2-related factor 2 (Nrf2), a vital oxidative stress regulator, and its downstream molecules heme oxygenase-1 (HO-1) and NADPH quinone oxidoreductase 1 (NQO1). Nrf2 knockout also aggravated DU-induced oxidative stress, mitochondrial dysfunction, and kidney damage. In conclusion, DU causes oxidative stress and antioxidant defense imbalance in renal cells through the ETHE1/Nrf2 pathway, further causing mitochondrial dysfunction and ultimately leading to nephrotoxicity.

Lactobacillus plantarum ZJUIDS14 alleviates non-alcoholic fatty liver disease in mice in association with modulation in the gut microbiota

This present study was designed to explore the protective role of Lactobacillus plantarum ZJUIDS14 against Non-alcoholic Fatty Liver Disease (NAFLD) in a high-fat-diet (HFD)-induced C57BL/6 mice model. The probiotic (10⁹ CFU/every other day) was administered by oral gavage for 12 weeks. We found that L. plantarum ZJUIDS14 intervention significantly alleviated HFD related hepatic steatosis, liver damage, insulin resistance, and increased hepatic expression of peroxisome proliferator activated receptor α (PPAR-α) while stimulating the activation of AMP-activated protein kinase (AMPK). Furthermore, L. plantarum ZJUIDS14 improved mitochondrial function as reflected by an increase in dynamin related protein 1 (DRP1) and a decrease of proteins associated with oxidative phosphorylation (OXPHOS) after the treatment. Additionally, mice from the L. plantarum ZJUIDS14 group had a restored intestinal flora and homeostasis involving Coprostanoligenes group, Ruminococcaceae UCG-014, Allobaculum, Ruminiclostridium 1, and Roseburia. Meanwhile, these five genera exhibited a significant (negative or positive) association with ileum inflammation mRNA levels and SCFA contents, by Spearman's correlation analysis. In general, our data demonstrated that L. plantarum ZJUIDS14 mitigates hepatic steatosis and liver damage induced by HFD. Specifically, they strengthened the integrity of the intestinal barrier, regulated gut microbiota, and improved mitochondrial function. Our data provide an experimental basis for L. plantarum ZJUIDS14 as a promising candidate to prevent NAFLD.

N-acetyloxfenicine strongly induces mitohormesis in mice as well as in insects

Mitohormesis defines the increase in fitness induced by adaptive responses to mild mitochondrial stress. Here, we show that N-acetyloxfenicine (NAO) exerted higher thermotolerance than an endogenous mitohormesis inducer, N-acetyltyrosine (NAT). This activity was not observed in armyworm larvae injected with oxfenicine, suggesting the importance of N-acetylation. NAO-induced hormetic effect was triggered by transient perturbation of mitochondria, which causes a small increase in ROS production and leads to retrograde responses including enhanced expression of antioxidant enzyme genes via activation of FoxO transcription factors. Furthermore, pretreatment with NAO significantly repressed stress-induced peroxidation of lipids in mice and growth of colorectal cancer HCT116 cells that had been transplanted into nude mice. Taken together, NAO is a potent mitohormesis inducer that is similar to NAT in terms of structure and functions.

Redox-metabolic reprogramming of skin in mice lacking functional Nrf2 under basal conditions and cold acclimation

Adaptive responses to environmental and physiological challenges, including exposure to low environmental temperature, require extensive structural, redox, and metabolic reprogramming. Detailed molecular mechanisms of such processes in the skin are lacking, especially the role of nuclear factor erythroid 2-related factor 2 (Nrf2) and other closely related redox-sensitive transcription factors Nrf1, Nrf3, and nuclear respiratory factor (NRF1). To investigate the role of Nrf2, we examined redox and metabolic responses in the skin of wild-type (WT) mice and mice lacking functional Nrf2 (Nrf2 KO) at room (RT, 24 ± 1°C) and cold (4 ± 1°C) temperature. Our results demonstrate distinct expression profiles of major enzymes involved in antioxidant defense and key metabolic and mitochondrial pathways in the skin, depending on the functional Nrf2 and/or cold stimulus. Nrf2 KO mice at RT displayed profound alterations in redox, mitochondrial and metabolic responses, generally akin to cold-induced skin responses in WT mice. Immunohistochemical analyses of skin cell compartments (keratinocytes, fibroblasts, hair follicle, and sebaceous gland) and spatial locations (nucleus and cytoplasm) revealed synergistic interactions between members of the Nrf transcription factor family as part of redox-metabolic reprogramming in WT mice upon cold acclimation. In contrast, Nrf2 KO mice at RT showed loss of NRF1 expression and a compensatory activation of Nrf1/Nrf3, which was abolished upon cold, concomitant with blunted redox-metabolic responses. These data show for the first time a novel role for Nrf2 in skin physiology in response to low environmental temperature, with important implications in human connective tissue diseases with altered thermogenic responses.

Puerarin Reduces Oxidative Damage and Photoaging Caused by UVA Radiation in Human Fibroblasts by Regulating Nrf2 and MAPK Signaling Pathways

Fibroblasts account for more than 95% of dermal cells maintaining dermal structure and function. However, UVA penetrates the dermis and causes oxidative stress that damages the dermis and accelerates skin aging. Puerarin, the main active ingredient of Puerariae lobata, has been demonstrated to withstand oxidative stress caused by a variety of factors. However, there are limited findings on whether puerarin protects fibroblasts from UVA-induced oxidative stress damage. The effects of puerarin on human skin fibroblasts (HSF) under UVA-induced oxidative stress were investigated in this study. It is found that puerarin upregulates antioxidant enzymes' mRNA expression level and their content through modulating the KEAP1-Nrf2/ARE signaling pathway, thus improving cell antioxidant capacity and successfully eliminating UVA-induced reactive oxygen species (ROS) and lipid oxidation product malondialdehyde (MDA). Additionally, puerarin blocks the overexpression of human extracellular signal-regulated kinase (ERK), human c-Jun amino-terminal kinase (JNK), and P38, which downregulates matrix metalloproteinase 1 (MMP-1) expression and increases type I collagen (COL-1) expression. Moreover, preliminary research on mouse skin suggests that puerarin can hydrate, moisturize, and increase the antioxidant capacity of skin tissue. These findings suggest that puerarin can protect the skin against photoaging.

The neuroprotective effects of fisetin, a natural flavonoid in neurodegenerative diseases: Focus on the role of oxidative stress

Oxidative stress (OS) disrupts the chemical integrity of macromolecules and increases the risk of neurodegenerative diseases. Fisetin is a flavonoid that exhibits potent antioxidant properties and protects the cells against OS. We have viewed the NCBI database, PubMed, Science Direct (Elsevier), Springer-Nature, ResearchGate, and Google Scholar databases to search and collect relevant articles during the preparation of this review. The search keywords are OS, neurodegenerative diseases, fisetin, etc. High level of ROS in the brain tissue decreases ATP levels, and mitochondrial membrane potential and induces lipid peroxidation, chronic inflammation, DNA damage, and apoptosis. The subsequent results are various neuronal diseases. Fisetin is a polyphenolic compound, commonly present in dietary ingredients. The antioxidant properties of this flavonoid diminish oxidative stress, ROS production, neurotoxicity, neuro-inflammation, and neurological disorders. Moreover, it maintains the redox profiles, and mitochondrial functions and inhibits NO production. At the molecular level, fisetin regulates the activity of PI3K/Akt, Nrf2, NF-κB, protein kinase C, and MAPK pathways to prevent OS, inflammatory response, and cytotoxicity. The antioxidant properties of fisetin protect the neural cells from inflammation and apoptotic degeneration. Thus, it can be used in the prevention of neurodegenerative disorders.

Essential role of Nrf2 in sulforaphane-induced protection against angiotensin II-induced aortic injury

AIMS

Cardiovascular disease (CVD) is the leading cause of death worldwide. Inflammation and oxidative stress are the primary factors underlying angiotensin II (Ang II)-induced aortic damage. Nuclear factor erythroid 2-related factor 2 (Nrf2) is an important antioxidative stress factor. Sulforaphane (SFN), which is naturally found in cruciferous vegetables, is an Nrf2 agonist that is safe for oral administration. Here, we aimed to explore the potential of SFN in protecting against Ang II-induced aortic damage by upregulating Nrf2 expression via the extracellular signal-regulated kinase (ERK)/glycogen synthase kinase-3 beta (GSK-3β)/Fyn pathway.

MAIN METHODS AND KEY FINDINGS

Wild-type (WT) C57BL/6J and Nrf2-knockout (Nrf2-KO) mice were injected with Ang II to induce aortic inflammation, oxidative stress, and cardiac remodeling (increased fibrosis and wall thickness). SFN treatment prevented aortic damage via Nrf2 activation in the WT mice. However, the protective effect of SFN on Ang II-induced aortic damage and upregulation of genes downstream of Nrf2 were not observed in Nrf2-KO mice. SFN induced the upregulation of aortic Nrf2 and inhibited the accumulation of ERK, GSK-3β, and Fyn in the nuclei.

SIGNIFICANCE

These results revealed that Nrf2 plays a central role in protecting against Ang II-induced aortic injury. Furthermore, SFN prevented Ang II-induced aortic damage by activating Nrf2 through the ERK/GSK-3β/Fyn pathway.

Redox-based disruption of cellular hormesis and promotion of degenerative pathways: perspectives on ageing processes

The present work aims to link the redox and cell-centric theories of chronic processes in human biology, focusing on ageing. A synthetic overview of cellular redox pathways will be integrated by the concept of hormesis, which disruption leads to several physiopathological processes. The onset of age-related diseases due to the restriction of homeodynamic capacity will be herein considered in a redox fashion. Up-to-date arguments on hormetic agents, such as geroprotectors, dietary interventions, and physical exercise are refining the presented theoretical framework, integrated by insights from extracellular vesicles, microbiota, pollutants, and timing mechanisms. The broad concepts of exposome encompass the redox-based alteration of cellular hormesis for providing meaningful perspectives on redox biogerontology.

HSF-1: Guardian of the Proteome Through Integration of Longevity Signals to the Proteostatic Network

Discoveries made in the nematode Caenorhabditis elegans revealed that aging is under genetic control. Since these transformative initial studies, C. elegans has become a premier model system for aging research. Critically, the genes, pathways, and processes that have fundamental roles in organismal aging are deeply conserved throughout evolution. This conservation has led to a wealth of knowledge regarding both the processes that influence aging and the identification of molecular and cellular hallmarks that play a causative role in the physiological decline of organisms. One key feature of age-associated decline is the failure of mechanisms that maintain proper function of the proteome (proteostasis). Here we highlight components of the proteostatic network that act to maintain the proteome and how this network integrates into major longevity signaling pathways. We focus in depth on the heat shock transcription factor 1 (HSF1), the central regulator of gene expression for proteins that maintain the cytosolic and nuclear proteomes, and a key effector of longevity signals.

Zinc Oxide Nanoparticle Improves the Intestinal Function of Intrauterine Growth Retardation Finishing Pigs via Regulating Intestinal Morphology, Inflammation, Antioxidant Status and Autophagy

This study was to investigate effects of zinc oxide nanoparticle (Nano-ZnO) on growth, immunity, intestinal morphology and function of intrauterine growth retardation (IUGR) finishing pigs. Six normal birth weight (NBW) and 12 IUGR male piglets were obtained and weaned at 21 d. NBW-weaned piglets fed basal diets (NBW group), IUGR-weaned piglets allocated to two groups fed basal diets (IUGR group) and basal diets further supplemented 600 mg Zn/kg from Nano-ZnO (IUGR+Zn group), respectively. All pigs were slaughtered at 163 d. Results showed: (1) IUGR pigs showed no difference in body weight at 77d and 163d (P > 0.05), while had increased villus height (VH) and villus surface area in jejunum (P < 0.05) and enhanced interleukin-6, TNF-α and NF-κB mRNA expression (P < 0.05) as compared to NBW group; Compared with IUGR group, dietary Nano-ZnO did not affect the body weight (P > 0.05), but increased VH to crypt depth ratio and IgA concentration (P < 0.05) and decreased TNF-α and NF-κB mRNA expression in jejunum (P < 0.05). (2) IUGR increased the number of swollen mitochondria and autolysosomes, and protein expressions of sequestosome-1 (P62) and microtubule-associated protein light chain 3 B/A (LC3B/A) in jejunum as compared to NBW group (P < 0.05); Compared with IUGR group, Nano-ZnO decreased the number of swollen mitochondria and autolysosomes, and P62 and LC3B/A protein expression (P < 0.05). (3) IUGR increased mucosal contents of malondialdehyde and protein carbonyl (PC) and Keap1 protein expression (P < 0.05) as compared to NBW group; Compared with IUGR group, dietary Nano-ZnO increased activities of total antioxidant capacity, catalase, glutathione peroxidase, and glutathione content (P < 0.05), and enhanced nuclear respiratory factor 2 (Nrf2), glutamate-cysteine ligase modifier subunit and glutathione peroxidase 1 mRNA expression, and increased total and nuclear Nrf2 protein expression (P < 0.05), and decreased malondialdehyde and PC content, and Keap1 protein expression (P < 0.05) in jejunum. Results suggested that IUGR pigs showed postnatal catch-up growth and improved intestinal morphology, and dietary Nano-ZnO may further improve intestinal morphology, reduce inflammation, decrease autophagy and alleviate oxidative stress via Nrf2/Keap1 pathway in jejunum of IUGR pigs.

Dietary phillygenin supplementation ameliorates aflatoxin B1-induced oxidative stress, inflammation, and apoptosis in chicken liver

Aflatoxin B₁ (AFB₁), a mycotoxin contaminating food and feed, can trigger liver immune toxicity and threaten the poultry industry. Phillygenin (PHI) is a natural lignan derived primarily from Forsythia suspensa with hepatoprotective pharmacological and medicinal properties. This research aimed to investigate the preventive effects of PHI on the toxicity of AFB₁ in the liver of chickens. Chickens were administered with AFB₁ (2.8 mg/kg) and/or treated with PHI (24 mg/kg) for 33 days. The histopathological changes, serum biochemical indices, oxidative damage, inflammatory mediators, apoptosis, and activation of the NF-κB and Nrf2 signaling pathways were measured. Results revealed that dietary PHI ameliorated liver function indicators, reduced the malondialdehyde and inflammatory mediator production and the apoptotic cell number, and increased the antioxidant enzyme contents and Bcl-2 level. The quantitative realtime PCR and Western blot results revealed that PHI reduced p53, cytochrome c, Bax, caspase-9, and caspase-3 levels, normalized the NF-κB p65 phosphorylation, and upregulated the Nrf2 and its downstream genes expression in chicken liver. These results indicated that PHI has beneficial effects on AFB₁-induced liver damage, oxidative damage, inflammatory response, apoptosis, and immunotoxicity by inhibiting NF-κB and activating the Nrf2 signaling pathway in chickens. This study provides new insight into the therapeutic uses of PHI.

Norketamine, the Main Metabolite of Ketamine, Induces Mitochondria-Dependent and ER Stress-Triggered Apoptotic Death in Urothelial Cells via a Ca2+-Regulated ERK1/2-Activating Pathway

Ketamine-associated cystitis is characterized by suburothelial inflammation and urothelial cell death. Norketamine (NK), the main metabolite of ketamine, is abundant in urine following ketamine exposure. NK has been speculated to exert toxic effects in urothelial cells, similarly to ketamine. However, the molecular mechanisms contributing to NK-induced urothelial cytotoxicity are almost unclear. Here, we aimed to investigate the toxic effects of NK and the potential mechanisms underlying NK-induced urothelial cell injury. In this study, NK exposure significantly reduced cell viability and induced apoptosis in human urinary bladder epithelial-derived RT4 cells that NK (0.01–0.5 mM) exhibited greater cytotoxicity than ketamine (0.1–3 mM). Signals of mitochondrial dysfunction, including mitochondrial membrane potential (MMP) loss and cytosolic cytochrome c release, were found to be involved in NK-induced cell apoptosis and death. NK exposure of cells also triggered the expression of endoplasmic reticulum (ER) stress-related proteins including GRP78, CHOP, XBP-1, ATF-4 and -6, caspase-12, PERK, eIF-2α, and IRE-1. Pretreatment with 4-phenylbutyric acid (an ER stress inhibitor) markedly prevented the expression of ER stress-related proteins and apoptotic events in NK-exposed cells. Additionally, NK exposure significantly activated JNK, ERK1/2, and p38 signaling and increased intracellular calcium concentrations ([Ca²⁺]_i). Pretreatment of cells with both PD98059 (an ERK1/2 inhibitor) and BAPTA/AM (a cell-permeable Ca²⁺ chelator), but not SP600125 (a JNK inhibitor) and SB203580 (a p38 inhibitor), effectively suppressed NK-induced mitochondrial dysfunction, ER stress-related signals, and apoptotic events. The elevation of [Ca²⁺]_i in NK-exposed cells could be obviously inhibited by BAPTA/AM, but not PD98059. Taken together, these findings suggest that NK exposure exerts urothelial cytotoxicity via a [Ca²⁺]_i-regulated ERK1/2 activation, which is involved in downstream mediation of the mitochondria-dependent and ER stress-triggered apoptotic pathway, consequently resulting in urothelial cell death. Our findings suggest that regulating [Ca²⁺]_i/ERK signaling pathways may be a promising strategy for treatment of NK-induced urothelial cystitis.

Evolutionarily conserved transcription factors as regulators of longevity and targets for geroprotection

Aging is the single largest risk factor for many debilitating conditions, including heart diseases, stroke, cancer, diabetes, and neurodegenerative disorders. While far from understood in its full complexity, it is scientifically well-established that aging is influenced by genetic and environmental factors, and can be modulated by various interventions. One of aging's early hallmarks are aberrations in transcriptional networks, controlling for example metabolic homeostasis or the response to stress. Evidence in different model organisms abounds that a number of evolutionarily conserved transcription factors, which control such networks, can affect lifespan and healthspan across species. These transcription factors thus potentially represent conserved regulators of longevity and are emerging as important targets in the challenging quest to develop treatments to mitigate age-related diseases, and possibly even to slow aging itself. This review provides an overview of evolutionarily conserved transcription factors that impact longevity or age-related diseases in at least one multicellular model organism (nematodes, flies, or mice), and/or are tentatively linked to human aging. Discussed is the general evidence for transcriptional regulation of aging and disease, followed by a more detailed look at selected transcription factor families, the common metabolic pathways involved, and the targeting of transcription factors as a strategy for geroprotective interventions.

Target Fishing Reveals a Novel Mechanism of 1,2,4-Oxadiazole Derivatives Targeting Rpn6, a Subunit of 26S Proteasome

1,2,4-Oxadiazole derivatives, a class of Nrf2-ARE activators, exert an extensive therapeutic effect on inflammation, cancer, neurodegeneration, and microbial infection. Among these analogues, DDO-7263 is the most potent Nrf2 activator and used as the core structure for bioactive probes to explore the precise mechanism. In this work, we obtained compound 7, a mimic of DDO-7263, and biotin-labeled and fluorescein-based probes, which exhibited homologous biological activities to DDO-7263, including activating Nrf2 and its downstream target genes, anti-oxidative stress, and anti-inflammatory effects. Affinity chromatography and mass analysis techniques revealed Rpn6 as the potential target protein regulating the Nrf2 signaling pathway. In vitro affinity experiments further confirmed that DDO-7263 upregulated Nrf2 through binding to Rpn6 to block the assembly of 26S proteasome and the subsequent degradation of ubiquitinated Nrf2. These results indicated that Rpn6 is a promising candidate target to activate the Nrf2 pathway for protecting cells and tissues from oxidative, electrophilic, and exogenous microbial stimulation.

Ferulic acid and berberine, via Sirt1 and AMPK, may act as cell cleansing promoters of healthy longevity

Ferulic acid, a bacterial metabolite of anthocyanins, seems likely to be a primary mediator of the health benefits associated with anthocyanin-rich diets, and has long been employed in Chinese cardiovascular medicine. In rodent studies, it has exerted wide-ranging antioxidant and anti-inflammatory effects, the molecular basis of which remains rather obscure. However, recent studies indicate that physiologically relevant concentrations of ferulic acid can boost expression of Sirt1 at mRNA and protein levels in a range of tissues. Sirt1, a class III deacetylase, functions to detect a paucity of oxidisable substrate, and in response works in various ways to promote cellular survival and healthful longevity. Sirt1 promotes ‘cell cleansing’ and cell survival by boosting autophagy, mitophagy, mitochondrial biogenesis, phase 2 induction of antioxidant enzymes via Nrf2, and DNA repair—while inhibiting NF-kB-driven inflammation, apoptosis, and cellular senescence, and boosting endothelial expression of the protective transcription factor kruppel-like factor 2. A deficit of the latter appears to mediate the endothelial toxicity of the SARS-CoV-2 spike protein. Ferulic acid also enhances the activation of AMP-activated kinase (AMPK) by increasing expression and activity of its activating kinase LKB1—whereas AMPK in turn amplifies Sirt1 activity by promoting induction of nicotinamide phosphoribosyltranferase, rate-limiting for generation of Sirt1’s obligate substrate NAD+. Curiously, AMPK acts by independent mechanisms to potentiate many of the effects mediated by Sirt1. Hence, it is proposed that ferulic acid may exert complementary or synergistic health-promoting effects when used in conjunction with clinically useful AMPK activators, such as the nutraceutical berberine. Additional nutraceuticals which might have potential for amplifying certain protective effects of ferulic acid/berberine are also discussed.

Macrophages Protect Endometriotic Cells Against Oxidative Damage Through a Cross-Talk Mechanism

This aim of this study was to investigate whether macrophages protect endometriotic cells from oxidative injury and to elucidate the underlying mechanisms of any protection. Endometriotic cells cultured with or without differentiated macrophages (dTHP-1 cells) were treated with hydrogen peroxide (H₂O₂) or methemoglobin, a major component of hemoglobin species in endometriotic cyst fluid. Co-culture experiments, microarray analysis, screening and validation of differentially expressed genes (DEGs), cell proliferation and viability assays, and experiments using a specific inhibitor were conducted to investigate the functional cross-talk between endometriotic cells and macrophages. Microarray analysis revealed that endometriotic cells co-cultured with dTHP-1 differentially express several genes compared with monoculture. Quantitative enzyme-linked immunosorbent assay (ELISA) and Western blotting analysis identified TGF-β1 as a promising candidate gene expressed in endometriotic cells co-cultured with dTHP-1 cells. TGF-β1 stimulated the expression of heme oxygenase-1 (HO-1) in dTHP-1 cells. HO-1 expression was increased in dTHP-1 cells co-cultured with endometriotic cells compared with the dTHP-1 monoculture. Both H₂O₂ and methemoglobin upregulated the expression of the HO-1 protein in the dTHP-1 monoculture; moreover, co-culture with endometriotic cells further enhanced HO-1 production. The co-culture with dTHP-1 protected endometriotic cells against oxidative injury. Blockade of HO-1 abolished the protective effects of macrophages. In an oxidative stress environment, TGF-β1 produced by endometriotic cells may protect against oxidative injury through the upregulation of macrophage-derived HO-1. The cross-talk between endometriotic cells and macrophages may contribute to the progression and pathogenesis of endometriosis.

Curcumin reduces oxidative stress and fat deposition in longissimus dorsi muscle of intrauterine growth-retarded finishing pigs

Dietary curcumin possessing multiple biological activities may be an effective way to alleviate oxidative damage and fat deposition in intrauterine growth retardation (IUGR) finishing pigs. Therefore, this study was conducted to evaluate effects of dietary curcumin on meat quality, antioxidant capacity, and fat deposition of longissimus dorsi muscle in IUGR finishing pigs. Twelve normal birth weight (NBW) and 24 IUGR female piglets at 26 days of age were divided into 3 dietary groups: NBW (basal diet), IUGR (basal diet), and IUGR + Cur (basal diet supplemented with 200 mg/kg curcumin). The trial lasted for 169 days. Results showed that IUGR increased concentrations of malondialdehyde (MDA) and protein carbonyls (PC) and fat deposition in longissimus dorsi muscle. However, curcumin decreased the intramuscular fat content and the levels of MDA and PC and improved meat quality in IUGR pigs. Furthermore, curcumin inhibited the decrease of nuclear factor erythroid 2-related factor 2 (Nrf2) protein expression and decreased peroxisome pro liferator-activated receptors γ (PPARγ) expression in IUGR pigs. These findings suggested that dietary addition of 200 mg/kg curcumin could improve meat quality, alleviate oxidative stress through activating Nrf2 signaling pathway, and reduce fat deposition via inhibiting PPARγ expression in longissimus dorsi muscle of IUGR finishing pigs.

Sulforaphane inhibits the production of Aβ partially through the activation of Nrf2-regulated oxidative stress

Sulforaphane (SFN), a potent nuclear factor erythroid 2-related factor 2 (Nrf2) activator, presents a potential role in improving Alzheimer's disease (AD)-specific symptoms. However, the regulation mechanism of SFN in AD is poorly understood. Here, we established AD models both in vitro and in vivo. Animal behaviors were tested by the Morris water maze test. The pathology of the hippocampus and the content of Aβ were detected. SFN (40 mg kg^-1) decreased the escape latency (24.96 ± 7.43 s) and increased the target-zone frequency (3.19 ± 1.19) in rats. SFN improved the pathological morphology and the number of neurons in the hippocampus. Additionally, SFN significantly upregulated the contents of thioredoxin and glutathione as well as the activities of antioxidant enzymes, along with the expression of the Nrf2 protein. Conversely, SFN lowered the Aβ content and ROS level in N2a/APP cells. After silencing the Nrf2 by SiRNA, the inhibitory effects of SFN on ROS and Aβ production were partially weakened. In conclusion, the improvement of AD by SFN was closely related with Nrf2 activation.

Butylated hydroxyl-toluene, 2,4-Di-tert-butylphenol, and phytol of Chlorella sp. protect the PC12 cell line against H2O2-induced neurotoxicity

Oxidative stress is considered the main cause of cellular damage in a number of neurodegenerative disorders. One suitable ways to prevent cell damage is the use of the exogenous antioxidant capacity of natural products, such as microalgae. In the present study, four microalgae extracts, isolated from the Persian Gulf, were screened to analyze their potential antioxidant activity and free radical scavenging using ABTS, DPPH, and FRAP methods. The methanolic extracts (D1M) of green microalgae derived from Chlorella sp. exhibited potent free radical scavenging activity. In order to characterize microalgae species, microscopic observations and analysis of the expression of 18S rRNA were performed. The antioxidant and neuroprotective effects of D1M on H₂O₂-induced toxicity in PC12 cells were investigated. The results demonstrated that D1M significantly decreased the release of nitric oxide (NO), formation of intracellular reactive oxygen species (ROS), and the level of malondialdehyde (MDA), whereas it enhanced the content of glutathione (GSH), and activity of heme oxygenase 1 (HO-1), NAD(P)H: quinone oxidoreductase 1 (NQO1), and catalase (CAT) in PC12 cells exposed to H₂O₂. The pretreatment of D1M improved cell viability as measured by the MTT assay and invert microscopy, reduced cell apoptosis as examined by flow cytometry analysis, increased mitochondrial membrane potential (MMP), and diminished caspase-3 activity. The GC/MS analysis revealed that D1M ingredients have powerful antioxidant and anti-inflammatory compounds, such as butylated hydroxytoluene (BHT), 2,4-di-tert-butyl-phenol (2,4-DTBP), and phytol. These results suggested that Chlorella sp. extracts have strong potential to be applied as neuroprotective agents, for the treatment of neurodegenerative disorders.

Fisetin, potential flavonoid with multifarious targets for treating neurological disorders: An updated review

Neurodegenerative disorders pose a significant health burden and imprint a debilitative impact on the quality of life. Importantly, aging is intricately intertwined with the progression of these disorders, and their prevalence increases with a rise in the aging population worldwide. In recent times, fisetin emerged as one of the potential miracle molecules to address neurobehavioral and cognitive abnormalities. These effects were attributed to its actions on several macromolecules and multiple molecular mechanisms. Fisetin belongs to a class of flavonoids, which is found abundantly in several fruits and vegetables. Fisetin has manifested several health benefits in preclinical models of neurodegenerative diseases such as Alzheimer's disease, Vascular dementia, and Schizophrenia. Parkinson's disease, Amyotrophic Lateral Sclerosis, Huntington's disease, Stroke, Traumatic Brain Injury (TBI), and age-associated changes. This review aimed to evaluate the potential mechanisms and pharmacological effects of fisetin in treating several neurological diseases. This review also provides comprehensive data on up-to-date recent literature and highlights the various mechanistic pathways pertaining to fisetin's neuroprotective role.

Drosophila melanogaster as a Model Organism to Study Lithium and Boron Bioactivity

The fruit fly Drosophila melanogaster has become a valuable model organism in nutritional science, which can be applied to elucidate the physiology and the biological function of nutrients, including trace elements. Importantly, the application of chemically defined diets enables the supply of trace elements for nutritional studies under highly standardized dietary conditions. Thus, the bioavailability and bioactivity of trace elements can be systematically monitored in D. melanogaster. Numerous studies have already revealed that central aspects of trace element homeostasis are evolutionary conserved among the fruit fly and mammalian species. While there is sufficient evidence of vital functions of boron (B) in plants, there is also evidence regarding its bioactivity in animals and humans. Lithium (Li) is well known for its role in the therapy of bipolar disorder. Furthermore, recent findings suggest beneficial effects of Li regarding neuroprotection as well as healthy ageing and longevity in D. melanogaster. However, no specific essential function in the animal kingdom has been found for either of the two elements so far. Here, we summarize the current knowledge of Li and B bioactivity in D. melanogaster in the context of health and disease prevention.

The Diabetic Cardiomyopathy: The Contributing Pathophysiological Mechanisms

Individuals with diabetes mellitus (DM) disclose a higher incidence and a poorer prognosis of heart failure (HF) than non-diabetic people, even in the absence of other HF risk factors. The adverse impact of diabetes on HF likely reflects an underlying “diabetic cardiomyopathy” (DM–CMP), which may by exacerbated by left ventricular hypertrophy and coronary artery disease (CAD). The pathogenesis of DM-CMP has been a hot topic of research since its first description and is still under active investigation, as a complex interplay among multiple mechanisms may play a role at systemic, myocardial, and cellular/molecular levels. Among these, metabolic abnormalities such as lipotoxicity and glucotoxicity, mitochondrial damage and dysfunction, oxidative stress, abnormal calcium signaling, inflammation, epigenetic factors, and others. These disturbances predispose the diabetic heart to extracellular remodeling and hypertrophy, thus leading to left ventricular diastolic and systolic dysfunction. This Review aims to outline the major pathophysiological changes and the underlying mechanisms leading to myocardial remodeling and cardiac functional derangement in DM-CMP.

Photobiomodulation has rejuvenating effects on aged bone marrow mesenchymal stem cells

The plasticity and proliferative capacity of stem cells decrease with aging, compromising their tissue regenerative potential and therapeutic applications. This decline is directly linked to mitochondrial dysfunction. Here, we present an effective strategy to reverse aging of mouse bone marrow mesenchymal stem cells (BM-MSCs) by restoring their mitochondrial functionality using photobiomodulation (PBM) therapy. Following the characterization of young and aged MSCs, our results show that a near-infrared PBM treatment delivering 3 J/cm2 is the most effective modality for improving mitochondrial functionality and aging markers. Furthermore, our results unveil that young and aged MSCs respond differently to the same modality of PBM: whereas the beneficial effect of a single PBM treatment dissipates within 7 h in aged stem cells, it is lasting in young ones. Nevertheless, by applying three consecutive treatments at 24-h intervals, we were able to obtain a lasting rejuvenating effect on aged MSCs. Our findings are of particular significance for improving autologous stem cell transplantation in older individuals who need such therapies most.

Impact of Moriamin Forte on Testicular and Epididymal Damage in Rats with Oligoasthenospermia

To investigate the effect and mechanism of action of Moriamin Forte (MF) on oligoasthenospermia (OA) in rats exposed to multiglycosides of Tripterygium wilfordii (GTW), forty male Sprague Dawley rats were randomly divided into four groups. Rats in the control group were treated with 0.5% sodium carboxymethyl cellulose. The remaining rats were administered GTW (30 mg/kg/d) for 40 d to establish an OA model. Concurrently, the groups were treated with normal saline and low-dose (100 mg/kg/d) and high-dose (200 mg/kg/d) MF, respectively. After treatment, the number and motility of sperm cells were examined. Testicular and epididymal histomorphology changes were observed. Antioxidant indicators (SOD, CAT, MDA, TAC, and Nrf2) in testicular and epididymal tissues were detected. Apoptotic and antiapoptotic indicators (Bax and Bcl2 expression) in the testicular tissue were measured by immunohistochemistry. GTW decreased sperm count and motility, damaged testicular and epididymis tissues, impaired antioxidase activity, and increased tissue MDA levels. Meanwhile, GTW upregulated the expression of Bax and downregulated the expression of Bcl2. Western blot analysis demonstrated a decrease in the Nrf2 expression in the model group. Treatment with MF improved sperm count and motility, as well as inhibited the rate of apoptosis in the rat reproductive system. Moreover, MF improved the activity of antioxidants and increased the relative expression of the antioxidant pathway-related protein Nrf2. In conclusion, MF may reverse the GTW-induced OA by modulating the expression of apoptotic and antioxidant pathway-related proteins. This study may provide a pharmacological foundation for the use of MF in OA treatment.

Chronic treatment with acetaminophen protects against liver aging by targeting inflammation and oxidative stress

The liver exhibits a variety of functions that are well-preserved during aging. However, the cellular hallmarks of aging increase the risk of hepatic alterations and development of chronic liver diseases. Acetaminophen (APAP) is a first choice for relieving mild-to-moderate pain. Most of the knowledge about APAP-mediated hepatotoxicity arises from acute overdose studies due to massive oxidative stress and inflammation, but little is known about its effect in age-related liver inflammation after chronic exposure. Our results show that chronic treatment of wild-type mice on the B6D2JRcc/Hsd genetic background with APAP at an infratherapeutic dose reduces liver alterations during aging without affecting body weight. This intervention attenuates age-induced mild oxidative stress by increasing HO-1, MnSOD and NQO1 protein levels and reducing ERK1/2 and p38 MAPK phosphorylation. More importantly, APAP treatment counteracts the increase in Cd8⁺ and the reduction in Cd4⁺ T lymphocytes observed in the liver with age. This response was also found in peripheral blood mononuclear cells. In conclusion, chronic infratherapeutic APAP treatment protects mice from age-related liver alterations by attenuating oxidative stress and inflammation.

Impact of Polyphenolic-Food on Longevity: An Elixir of Life. An Overview

Aging and, particularly, the onset of age-related diseases are associated with tissue dysfunction and macromolecular damage, some of which can be attributed to accumulation of oxidative damage. Recently, growing interest has emerged on the beneficial effects of plant-based diets for the prevention of chronic diseases including obesity, diabetes, and cardiovascular disease. Several studies collectively suggests that the intake of polyphenols and their major food sources may exert beneficial effects on improving insulin resistance and related diabetes risk factors, such as inflammation and oxidative stress. They are the most abundant antioxidants in the diet, and their intake has been associated with a reduced aging in humans. Polyphenolic intake has been shown to be effective at ameliorating several age-related phenotypes, including oxidative stress, inflammation, impaired proteostasis, and cellular senescence, both in vitro and in vivo. In this paper, effects of these phytochemicals (either pure forms or polyphenolic-food) are reviewed and summarized according to affected cellular signaling pathways. Finally, the effectiveness of the anti-aging preventive action of nutritional interventions based on diets rich in polyphenolic food, such as the diets of the Blue zones, are discussed.

Morin hydrate: A comprehensive review on novel natural dietary bioactive compound with versatile biological and pharmacological potential

Flavonoids are natural plant-derived dietary bioactive compounds having a substantial impact on human health. Morin hydrate is a bioflavonoid mainly obtained from fruits, stem, and leaves of Moraceae family members' plants. Plenty of evidences supported that morin hydrate exerts its beneficial effects against various chronic and life-threatening degenerative diseases. Our current article discloses the recent advances that have been studied to explore the biological/pharmacological properties and molecular mechanisms to better understand the beneficial and multiple health benefits of morin hydrate. Indeed, Morin hydrate exerts free radical scavenging, antioxidant, anti-inflammatory, anti-cancerous, anti-microbial, antidiabetic, anti-arthritis, cardioprotective, neuroprotective, nephroprotective, and hepatoprotective effects. Moreover, morin hydrate exhibits its pharmacological activities by modulating various cellular signaling pathways such as Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-қB), Mitogen-activated protein kinase (MAPK), Janus kinases/ Signal transducer and activator of transcription proteins (JAKs/STATs), Kelch-like ECH-associated protein1/Nuclear erythroid-2-related factor (Keap1/Nrf2), Endoplasmic reticulum (ER), Mitochondrial-mediated apoptosis, Wnt/β-catenin, and Mechanistic target of rapamycin (mTOR). Most importantly, morin hydrate has the potential to modulate a variety of biological networks. Therefore, it can be predicted that this therapeutically potent compound could serve as a dietary agent for the expansion of human health and might be helpful for the development of the novel drug in the future. However, due to the lack of clinical trials, special human clinical trials are needed to address the effects of morin hydrate on various life-threatening disparities to recommend morin and/or morin-rich foods with other foods or bioactive dietary components, as well as dose-response interaction and safety profile.

Histone deacetylase 3 inhibition alleviates type 2 diabetes mellitus-induced endothelial dysfunction via Nrf2

BACKGROUND

The mechanism underlying endothelial dysfunction leading to cardiovascular disease in type 2 diabetes mellitus (T2DM) remains unclear. Here, we show that inhibition of histone deacetylase 3 (HDAC3) reduced inflammation and oxidative stress by regulating nuclear factor-E2-related factor 2 (Nrf2), which mediates the expression of anti-inflammatory- and pro-survival-related genes in the vascular endothelium, thereby improving endothelial function.

METHODS

Nrf2 knockout (Nrf2 KO) C57BL/6 background mice, diabetic db/db mice, and control db/m mice were used to investigate the relationship between HDAC3 and Nrf2 in the endothelium in vivo. Human umbilical vein endothelial cells (HUVECs) cultured under high glucose-palmitic acid (HG-PA) conditions were used to explore the role of Kelch-like ECH-associated protein 1 (Keap1) -Nrf2-NAPDH oxidase 4 (Nox4) redox signaling in the vascular endothelium in vitro. Activity assays, immunofluorescence, western blotting, qRT-PCR, and immunoprecipitation assays were used to examine the effect of HDAC3 inhibition on inflammation, reactive oxygen species (ROS) production, and endothelial impairment, as well as the activity of Nrf2-related molecules.

RESULTS

HDAC3 activity, but not its expression, was increased in db/db mice. This resulted in de-endothelialization and increased oxidative stress and pro-inflammatory marker expression in cells treated with the HDAC3 inhibitor RGFP966, which activated Nrf2 signaling. HDAC3 silencing decreased ROS production, inflammation, and damage-associated tube formation in HG-PA-treated HUVECs. The underlying mechanism involved the Keap1-Nrf2-Nox4 signaling pathway.

CONCLUSION

The results of this study suggest the potential of HDAC3 as a therapeutic target for the treatment of endothelial dysfunction in T2DM. Video Abstract.

N-acetyltyrosine-induced redox signaling in hormesis

A suite of adaptations allows insects to survive in hostile terrestrial environments for long periods of time. Temperature represents a key environmental factor for most ectothermic insects, and they rapidly acclimate to high and low temperatures. Vast amounts of data in this research field support the idea that an insect's ability to tolerate fluctuating temperatures can be regarded as a biphasic hormetic dose response. Observation indicates that their thermal hormetic response represents a conservative estimate of their intrinsic capacity for rapid adaptation to environmental changes in nature because they naturally experience diel or seasonal temperature fluctuations. It is therefore reasonable to suppose that the hormetic response in insects reflects a surplus physiological capacity to deal with temperature changes that they would experience naturally. Although it has been unknown how thermal acclimation is induced, a stress-dependent increase in N-acetyltyrosine (NAT) was recently found to occur in insect larvae who had endured high temperatures. NAT treatment was demonstrated to induce thermotolerance in several tested insect species. NAT was also identified in the serum of humans as well as mice, and its concentration in mice was shown to be increased by heat and restraint stress, with NAT pretreatment lowering the concentrations of corticosterone and peroxidized lipids in stressed mice. These recent findings may give us some hints about how long a hormetic response lasts. Here, I will discuss recent findings underlying hormetic responses induced by an intrinsic factor, NAT, and how the hormetic response may begin and end.

Crizotinib and Sunitinib Induce Hepatotoxicity and Mitochondrial Apoptosis in L02 Cells via ROS and Nrf2 Signaling Pathway

Considerable attention has been raised on crizotinib- and sunitinib-induced hepatotoxicity, but the underlying mechanisms need further examination. In addition, limited therapeutic strategies exist to reduce the liver damage caused by crizotinib and sunitinib. This study investigated the mechanisms of crizotinib- and sunitinib-induced hepatotoxicity and the potential mitigation through ROS and Nrf2 signaling. Firstly, crizotinib and sunitinib reduced cell viability in human liver cells (L02 cells) and triggered dramatic liver injury in mice. Subsequently, we found that crizotinib and sunitinib activated the oxidative stress response (decreased level of GPx and SOD, and increased MDA content) in vivo. Crizotinib and sunitinib also stimulated hepatocyte mitochondrial apoptosis and necrosis in L02 cells in a dose-dependent manner. In vivo studies further confirmed that crizotinib and sunitinib decreased mitochondrial membrane potential and activated apoptosis-associated proteins (cleaved-PARP, cleaved caspase3, cytochrome c, Bcl2 and Bax). Furthermore, mechanistic investigations demonstrated that crizotinib and sunitinib accumulated ROS and inhibited Nrf2 signaling, and that ROS scavenger NAC and Nrf2 agonist tBHQ alleviated the extent of cell damage and the mitochondrial apoptosis during crizotinib- and sunitinib-induced hepatotoxicity in L02 cells. Collectively, these findings indicated that NAC and tBHQ play the crucial roles in crizotinib- and sunitinib-induced mitochondrial apoptosis via the regulation of oxidative stress.

Nrf2 overexpression rescues the RPE in mouse models of retinitis pigmentosa

Nrf2, a transcription factor that regulates the response to oxidative stress, has been shown to rescue cone photoreceptors and slow vision loss in mouse models of retinal degeneration (rd). The retinal pigment epithelium (RPE) is damaged in these models, but whether it also could be rescued by Nrf2 has not been previously examined. We used an adeno-associated virus (AAV) with an RPE-specific (Best1) promoter to overexpress Nrf2 in the RPE of rd mice. Control rd mice showed disruption of the regular array of the RPE, as well as loss of RPE cells. Cones were lost in circumscribed regions within the cone photoreceptor layer. Overexpression of Nrf2 specifically in the RPE was sufficient to rescue the RPE, as well as the disruptions in the cone photoreceptor layer. Electron microscopy showed compromised apical microvilli in control rd mice but showed preserved microvilli in Best1-Nrf2–treated mice. The rd mice treated with Best1-Nrf2 had slightly better visual acuity. Transcriptome profiling showed that Nrf2 upregulates multiple oxidative defense pathways, reversing declines seen in the glutathione pathway in control rd mice. In summary, Nrf2 overexpression in the RPE preserves RPE morphology and survival in rd mice, and it is a potential therapeutic for diseases involving RPE degeneration, including age-related macular degeneration (AMD).

Potential Anti-Aging Substances Derived from Seaweeds

Aging is a major risk factor for many chronic diseases, such as cancer, cardiovascular disease, and diabetes. The exact mechanisms underlying the aging process are not fully elucidated. However, a growing body of evidence suggests that several pathways, such as sirtuin, AMP-activated protein kinase, insulin-like growth factor, autophagy, and nuclear factor erythroid 2-related factor 2 play critical roles in regulating aging. Furthermore, genetic or dietary interventions of these pathways can extend lifespan by delaying the aging process. Seaweeds are a food source rich in many nutrients, including fibers, polyunsaturated fatty acids, vitamins, minerals, and other bioactive compounds. The health benefits of seaweeds include, but are not limited to, antioxidant, anti-inflammatory, and anti-obese activities. Interestingly, a body of studies shows that some seaweed-derived extracts or isolated compounds, can modulate these aging-regulating pathways or even extend lifespans of various animal models. However, few such studies have been conducted on higher animals or even humans. In this review, we focused on potential anti-aging bioactive substances in seaweeds that have been studied in cells and animals mainly based on their anti-aging cellular and molecular mechanisms.

A novel mechanism of protection against isoproterenol-induced cardiac inflammation via regulation of the SIRT1/NRF2 signaling pathway with a natural SIRT1 agonist

Stress-induced cardiomyopathy (SIC) is associated with high mortality rates, potentially due to a lack of available therapies. To facilitate the identification of therapeutic targets for SIC, we explored the detailed mechanisms of disease onset and progression using a mouse model. Over-activation of the β-adrenergic receptor (β-AR) upon stress leads to inflammasome activation, cytokine cascades, macrophage infiltration, and pathological cardiac remodeling in mice, mimicking SIC. However, the detailed mechanisms by which acute β-AR stimulation induces cardiac inflammation remain elusive. We found that resveratrol (RSV) could attenuate isoproterenol-induced cardiac inflammation in mice, suggesting that RSV might be a promising therapeutic option in SIC. Mechanistically, we revealed that the SIRT1/NRF2 signaling pathway is the bona fide target of RSV and plays a significant role in the RSV-induced protective effect in cardiac inflammation.

The Keap1/Nrf2 Signaling Pathway in the Thyroid-2020 Update

The thyroid gland has a special relationship with oxidative stress. On the one hand, like all other tissues, it must defend itself against reactive oxygen species (ROS). On the other hand, unlike most other tissues, it must also produce reactive oxygen species in order to synthesize its hormones that contribute to the homeostasis of other tissues. The thyroid must therefore also rely on antioxidant defense systems to maintain its own homeostasis in the face of continuous self-exposure to ROS. One of the main endogenous antioxidant systems is the pathway centered on the transcription factor Nuclear factor erythroid 2-related factor 2 (Nrf2) and its cytoplasmic inhibitor Kelch-like ECH-associated protein 1 (Keap1). Over the last few years, multiple links have emerged between the Keap1/Nrf2 pathway and thyroid physiology, as well as various thyroid pathologies, including autoimmunity, goiter, hypothyroidism, hyperthyroidism, and cancer. In the present mini-review, we summarize recent studies shedding new light into the roles of Keap1/Nrf2 signaling in the thyroid.

Melatonin-Nrf2 Signaling Activates Peroxisomal Activities in Porcine Cumulus Cell-Oocyte Complexes

Melatonin and Nrf2 signaling synergistically improve mammalian oocyte maturation and embryonic development. Furthermore, previous studies have suggested an interplay between peroxisomes and Nrf2 signaling in cells, but it is still unclear whether peroxisomes are involved in oocyte maturation. The aim of the present study was to identify the possible roles of peroxisomes in the melatonin-Nrf2 signaling pathway during in vitro maturation (IVM) of porcine oocytes. Porcine oocytes were treated with melatonin (10^-9 M) and brusatol, a Nrf2 specific inhibitor, in order to investigate the mechanism. Then, the rates of maturation and related gene and protein expression were analyzed. During oocyte maturation, melatonin upregulated the expression of gene and protein related to Nrf2 signaling and peroxisomal activities; RNA sequencing partially validated these results. Our results demonstrate that melatonin can activate Nrf2 signaling by binding to melatonin receptor 2, resulting in the upregulation of catalase. Moreover, peroxisomes were also found to be activated in response to melatonin treatment, causing the activation of catalase; together with Nrf2 signaling, peroxisomes synergistically prevented the generation of reactive oxygen species and enhanced oocyte quality. Thus, we suggest that a crosstalk might exist between Nrf2 signaling and peroxisomal activities in porcine oocytes.

Effects of taraxasterol against ethanol and high-fat diet-induced liver injury by regulating TLR4/MyD88/NF-κB and Nrf2/HO-1 signaling pathways

Studies have reported that taraxasterol (TAR) is effective in the treatment of immune liver injury and alcoholic liver injury. The mechanism of action is mainly related to the inhibition of inflammation. To determine the key molecular mechanisms for the effect of TAR on alleviating ethanol and high-fat diet-induced liver injury, pathological morphology, biochemistry, oxidative stress, inflammatory response and lipid metabolism were examined. Our results showed that TAR could inhibit ethanol-induced hepatocyte death or lipid accumulation, and suppress oxidative stress, inflammatory response and lipid metabolism disorders. More specifically, ethanol-induced TLR-4 and MyD88 inflammatory response were down-regulated, when treated with TAR. Production of CYP2E1, Nrf2 and HO-1, which produced in response to increased oxidative stress, were regulated in TAR treated, ethanol-induced hepatocytes. In summary, TAR could inhibit the inflammatory response and oxidative stress, which was related to the regulation of TAR on TLR-4/MyD88/NF-κB and Nrf2/HO-1 pathways.