Nutrient Sensing and the Oxidative Stress Response

Oxidative stress and aging: synergies for age related diseases

Aging is characterized by a progressive decline in physiological function and underlies several disabilities, including the increased sensitivity of cells and tissues to undergo pathological oxidative stress. In recent years, efforts have been made to better understand the relationship between age and oxidative stress and further develop therapeutic strategies to minimize the impact of both events on age-related diseases. In this work, we review the impact of the oxidant and antioxidant systems during aging and disease development and discuss the crosstalk of oxidative stress and other aging processes, with a focus on studies conducted in elderly populations.

Antioxidant Potential of Exosomes in Animal Nutrition

This review delves into the advantages of exosomes as novel antioxidants in animal nutrition and their potential for regulating oxidative stress. Although traditional nutritional approaches promote oxidative stress defense systems in mammalian animals, several issues remain to be solved, such as low bioavailability, targeted tissue efficiency, and high-dose by-effect. As an important candidate offering regulation opportunities concerned with cellular communication, disease prevention, and physiology regulation in multiple biological systems, the potential of exosomes in mediating redox status in biological systems has not been well described. A previously reported relationship between redox system regulation and circulating exosomes suggested exosomes as a fundamental candidate for both a regulator and biomarker for a redox system. Herein, we review the effects of oxidative stress on exosomes in animals and the potential application of exosomes as antioxidants in animal nutrition. Then, we highlight the advantages of exosomes as redox regulators due to their higher bioavailability and physiological heterogeneity-targeted properties, providing a theoretical foundation and feed industry application. Therefore, exosomes have shown great potential as novel antioxidants in the field of animal nutrition. They can overcome the limitations of traditional antioxidants in terms of dosage and side effects, which will provide unprecedented opportunities in nutritional management and disease prevention, and may become a major breakthrough in the field of animal nutrition.

Pterostilbene, a Resveratrol Derivative, Improves Ovary Function by Upregulating Antioxidant Defenses in the Aging Chickens via Increased SIRT1/Nrf2 Expression

Oxidative stress is recognized as a prominent factor contributing to follicular atresia and ovarian aging, which leads to decreased laying performance in hens. Reducing oxidative stress can improve ovarian function and prolong the laying period in poultry. This study investigates the impact of Pterostilbene (PTS), a natural antioxidant, on ovarian oxidative stress in low-laying chickens. Thirty-six Hy-Line White laying chickens were evenly divided into four groups and fed diets containing varying doses of PTS for 15 consecutive days. The results showed that dietary supplementation with PTS significantly increased the laying rate, with the most effective group exhibiting a remarkable 42.7% increase. Furthermore, PTS significantly enhanced the antioxidant capacity of aging laying hens, as evidenced by increased levels of glutathione, glutathione peroxidase, superoxide dismutase, catalase, and total antioxidant capacity in the ovaries, livers, and serum. Subsequent experiments revealed decreased expressions of Bax, Caspase-3, and γ-H2AX, along with an increased expression of BCL-2 in the ovaries and livers of laying hens. PTS supplementation also positively affects fat metabolism by reducing abdominal fat accumulation and promoting fat transfer from the liver to the ovary. To elucidate the mechanism underlying the effects of PTS on ovarian function, a series of in vitro experiments were conducted. These in vitro experiments revealed that PTS pretreatment restored the antioxidant capacity of D-galactose-induced small white follicles by upregulating SIRT1/Nrf2 expression. This protective effect was inhibited by EX-527, a specific inhibitor of SIRT1. These findings suggest that the natural antioxidant PTS has the potential to regulate cell apoptosis and fat metabolism in laying chickens by ameliorating oxidative stress, thereby enhancing laying performance.

Engineering extracellular vesicles for ROS scavenging and tissue regeneration

Stem cell therapy holds promise for tissue regeneration, yet significant challenges persist. Emerging as a safer and potentially more effective alternative, extracellular vesicles (EVs) derived from stem cells exhibit remarkable abilities to activate critical signaling cascades, thereby facilitating tissue repair. EVs, nano-scale membrane vesicles, mediate intercellular communication by encapsulating a diverse cargo of proteins, lipids, and nucleic acids. Their therapeutic potential lies in delivering cargos, activating signaling pathways, and efficiently mitigating oxidative stress-an essential aspect of overcoming limitations in stem cell-based tissue repair. This review focuses on engineering and applying EVs in tissue regeneration, emphasizing their role in regulating reactive oxygen species (ROS) pathways. Additionally, we explore strategies to enhance EV therapeutic activity, including functionalization and incorporation of antioxidant defense proteins. Understanding these molecular mechanisms is crucial for optimizing EV-based regenerative therapies. Insights into EV and ROS signaling modulation pave the way for targeted and efficient regenerative therapies harnessing the potential of EVs.

The Naples prognostic score serves as a predictor and prognostic indicator for cancer survivors in the community

OBJECTIVE

Inflammation, malnutrition, and cancer are intricately interconnected. Despite this, only a few studies have delved into the relationship between inflammatory malnutrition and the risk of death among cancer survivors. This study aimed to specifically investigate the association between the categorically defined Naples prognostic score (NPS) and the prognosis of cancer survivors.

METHODS

Data from 42,582 participants in the National Health and Nutrition Examination Survey (NHANES, 1999-2018) were subjected to analysis. Naples prognostic scores (NPS) were computed based on serum albumin (ALB), total cholesterol (TC), neutrophil to lymphocyte ratio (NLR), and lymphocyte to monocyte ratio (LMR), and participants were stratified into three groups accordingly. Cancer status was ascertained through a self-administered questionnaire, while mortality data were sourced from the National Death Index up to December 31, 2019. Multiple logistic regression was employed to estimate the odds ratio (OR) with a 95% confidence interval (CI) between NPS and cancer prevalence within the U.S. community population. Kaplan-Meier survival analysis and the Log-rank test were utilized to compare survival disparities among the three groups. Additionally, Cox proportional regression was utilized to estimate the hazard ratio (HR) with a 95% CI.

RESULTS

The incidence of cancers was 9.86%. Among the participants, 8140 individuals (19.1%) were classified into Group 0 (NPS 0), 29,433 participants (69.1%) into Group 1 (NPS 1 or 2), and 5009 participants (11.8%) into Group 2 (NPS 3 or 4). After adjusting for confounding factors, the cancer prevalence for the highest NPS score yielded an odds ratio (OR) of 1.64 (95% CI: 1.36, 1.97) (P(for trend) < 0.05). In comparison to cancer survivors in Group 0, those with the highest NPS had adjusted hazard ratios (HRs) of 2.57 (95% CI: 1.73, 3.84) for all-cause mortality, 3.44 (95% CI: 1.64, 7.21) for cardiovascular mortality, 1.60 (95% CI: 1.01, 2.56) for cancer mortality, and 3.15 (95% CI: 1.74, 5.69) for other causes of mortality (All P(for trend) < 0.05). These associations remained consistent when stratified by age, sex, race, and body mass index.

CONCLUSIONS

This study indicates that the Naples prognostic score (NPS), serving as a novel prognostic metric integrating inflammation and nutritional status, is closely linked to cancer prognosis within the general population.

Effect of intermittent fasting on adriamycin-induced nephropathy: Possible underlying mechanisms

PURPOSE

Intermittent fasting (IF) has been shown to induce a well-organized adaptive defense against stress inside the cells, which increases the production of anti-oxidant defenses, repair of DNA, biogenesis of mitochondria, and genes that combat inflammation. So, the goal of the current investigation was to identify the effects of IF on rats with adriamycin (ADR)-induced nephropathy and any potential underlying mechanisms.

METHODS

Four groups of 40 mature Sprague-Dawley male rats were allocated as follow; control, fasting, ADR, and ADR plus fasting. After 8 weeks of ADR administration urine, blood samples and kidneys were taken for assessment of serum creatinine (Cr), BUN, urinary proteins, indicators of oxidative damage (malondialdehyde (MDA), reduced glutathione (GSH) and Catalase (CAT) levels), histopathological examinations, immunohistochemical examinations for caspase-3, Sirt1, aquaporin2 (AQP2) and real time PCR for antioxidant genes; Nrf2, HO-1 in kidney tissues.

RESULTS

IF significantly improved serum creatinine, BUN and urinary protein excretion, oxidative stress (low MDA with high CAT and GSH), in addition to morphological damage to the renal tubules and glomeruli as well as caspase-3 production during apoptosis. Moreover, IF stimulates significantly the expression of Sirt1 and Nrf2/HO-1 and AQP2.

CONCLUSION

AQP2, Sirt1, Nrf2/HO-1 signaling may be upregulated and activated by IF, which alleviates ADR nephropathy. Enhancing endogenous antioxidants, reducing apoptosis and tubulointerstitial damage, and maintaining the glomerular membrane's integrity are other goals.

Oxymatrine alleviates high-fat diet/streptozotocin-induced non-alcoholic fatty liver disease in C57BL/6 J mice by modulating oxidative stress, inflammation and fibrosis

Non-alcoholic fatty liver disease (NAFLD) represents a complex complication of type 2 diabetes mellitus (T2DM). Oxymatrine (OMT) is an alkaloid extracted from Sophora flavescens with broad pharmacological effects. However, there is currently a lack of research on OMT in the field of NAFLD. The present study aimed to explore the effects and underlying mechanisms of oxymatrine in treating T2DM with NAFLD. The T2DM mice model was induced by high-fat diet (HFD) combined with streptozotocin (STZ) injection in male C57BL/6 J mice. Animals were randomly divided into four groups (n = 8): Control group, DC group, OMT-L group (45 mg/kg i.g.), and OMT-H group (90 mg/kg, i.g.). The drug was administered once a day for 8 weeks. In addition, HepG2 hepatocytes were incubated with palmitic acid (PA) to establish a fatty liver cell model. Treated with OMT, the body weight and fasting blood glucose (FBG) of DC mice were reduced and the liver organ coefficient was significantly optimized. Meanwhile, OMT markedly enhanced the activities of key antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px), and also reduced malondialdehyde (MDA) levels. These biochemical alterations were accompanied by noticeable improvements in liver histopathology. Furthermore, OMT down-regulated the expression of NOD-like receptor protein 3 (NLRP3), interleukin-1β (IL-1β), transforming growth factor-β1 (TGF-β1) and collagen I significantly, highlighting its potential in modulating inflammatory and fibrotic pathways. In conclusion, OMT improved liver impairment effectively in diabetic mice by suppressing oxidative stress, inflammation and fibrosis. These results suggest that OMT may represent a novel therapy for NAFLD with diabetes.

Beta hydroxybutyrate induces lung cancer cell death, mitochondrial impairment and oxidative stress in a long term glucose-restricted condition

BACKGROUND

Metabolic plasticity gives cancer cells the ability to shift between signaling pathways to facilitate their growth and survival. This study investigates the role of glucose deprivation in the presence and absence of beta-hydroxybutyrate (BHB) in growth, death, oxidative stress and the stemness features of lung cancer cells.

METHODS AND RESULTS

A549 cells were exposed to various glucose conditions, both with and without beta-hydroxybutyrate (BHB), to evaluate their effects on apoptosis, mitochondrial membrane potential, reactive oxygen species (ROS) levels using flow cytometry, and the expression of CD133, CD44, SOX-9, and β-Catenin through Quantitative PCR. The activity of superoxide dismutase, glutathione peroxidase, and malondialdehyde was assessed using colorimetric assays. Treatment with therapeutic doses of BHB triggered apoptosis in A549 cells, particularly in cells adapted to glucose deprivation. The elevated ROS levels, combined with reduced levels of SOD and GPx, indicate that oxidative stress contributes to the cell arrest induced by BHB. Notably, BHB treatment under glucose-restricted conditions notably decreased CD133 expression, suggesting a potential inhibition of cell survival through the downregulation of CD133 levels. Additionally, the simultaneous decrease in mitochondrial membrane potential and increase in ROS levels indicate the potential for creating oxidative stress conditions to impede tumor cell growth in such environmental settings.

CONCLUSION

The induced cell death, oxidative stress and mitochondria impairment beside attenuated levels of cancer stem cell markers following BHB administration emphasize on the distinctive role of metabolic plasticity of cancer cells and propose possible therapeutic approaches to control cancer cell growth through metabolic fuels.

Exploring Metabolic and Gut Microbiome Responses to Paraquat Administration in Male Wistar Rats: Implications for Oxidative Stress

In this study, we examined the metabolic and gut microbiome responses to paraquat (PQ) in male Wistar rats, focusing on oxidative stress effects. Rats received a single intraperitoneal injection of PQ at 15 and 30 mg/kg, and various oxidative stress parameters (i.e., MDA, SOD, ROS, 8-isoprostanes) were assessed after three days. To explore the omic profile, GC-qTOF and UHPLC-qTOF were performed to assess the plasma metabolome; 1H-NMR was used to assess the urine metabolome; and shotgun metagenomics sequencing was performed to study the gut microbiome. Our results revealed reductions in body weight and tissue changes, particularly in the liver, were observed, suggesting a systemic effect of PQ. Elevated lipid peroxidation and reactive oxygen species levels in the liver and plasma indicated the induction of oxidative stress. Metabolic profiling revealed changes in the tricarboxylic acid cycle, accumulation of ketone body, and altered levels of key metabolites, such as 3-hydroxybutyric acid and serine, suggesting intricate links between energy metabolism and redox reactions. Plasma metabolomic analysis revealed alterations in mitochondrial metabolism, nicotinamide metabolism, and tryptophan degradation. The gut microbiome showed shifts, with higher PQ doses influencing microbial populations (e.g., Escherichia coli and Akkermansia muciniphila) and metagenomic functions (pyruvate metabolism, fermentation, nucleotide and amino acid biosynthesis). Overall, this study provides comprehensive insights into the complex interplay between PQ exposure, metabolic responses, and gut microbiome dynamics. These findings enhance our understanding of the mechanisms behind oxidative stress-induced metabolic alterations and underscore the connections between xenobiotic exposure, gut microbiota, and host metabolism.

Involvement of Glutamate Cysteine Ligase Genes in Tolerance to Emamectin Benzoate in Spodoptera frugiperda and Their Putative Regulatory Mechanisms

As the rate-limiting enzyme in de novo Glutathione (GSH) biosynthesis, the mammalian glutamate cysteine ligase (Gcl) catalytic (Gclc) and modifier (Gclm) subunits are regulated at multiple levels, whereas the function and regulatory mechanism of insect Gcl remain to be explored. In this study, we identified and characterized SfGclc and SfGclm in Spodoptera frugiperda. SfGclc and SfGclm were highly expressed in the hindgut and relatively less expressed in other tissues. The exposure of the third instar larvae to LC30 of emamectin benzoate (EMB) significantly reduced the GSH content with a concomitant upregulation of SfGclc and SfGclm. Further in vivo pretreatment with L-BSO, the Gcl inhibitor, increased the susceptibility of S. frugiperda to EMB. Consistently, overexpression of SfGclc and SfGclm increased the Sf9 cell viability under EMB treatment. Finally, both RNAi and the dual-luciferase reporter assay in Sf9 cells revealed that SfGclc is regulated by transcription factor CncC. These data provide insights into the function and regulatory mechanism of insect Gcl, and they imply that disruption of the redox homeostasis might be a practical strategy to enhance the insecticidal activity of EMB and other insecticides.

The Reduction in the Mitochondrial Membrane Potential in Aging: The Role of the Mitochondrial Permeability Transition Pore

It is widely reported that the mitochondrial membrane potential, ∆Ψm, is reduced in aging animals. It was recently suggested that the lower ∆Ψm in aged animals modulates mitochondrial bioenergetics and that this effect is a major cause of aging since artificially increased ∆Ψm in C. elegans increased lifespan. Here, I critically review studies that reported reduction in ∆Ψm in aged animals, including worms, and conclude that many of these observations are best interpreted as evidence that the fraction of depolarized mitochondria is increased in aged cells because of the enhanced activation of the mitochondrial permeability transition pore, mPTP. Activation of the voltage-gated mPTP depolarizes the mitochondria, inhibits oxidative phosphorylation, releases large amounts of calcium and mROS, and depletes cellular NAD+, thus accelerating degenerative diseases and aging. Since the inhibition of mPTP was shown to restore ∆Ψm and to retard aging, the reported lifespan extension by artificially generated ∆Ψm in C. elegans is best explained by inhibition of the voltage-gated mPTP. Similarly, the reported activation of the mitochondrial unfolded protein response by reduction in ∆Ψm and the reported preservation of ∆Ψm in dietary restriction treatment in C. elegans are best explained as resulting from activation or inhibition of the voltage-gated mPTP, respectively.

Metabolites and Immune Response in Tumor Microenvironments

The remodeled cancer cell metabolism affects the tumor microenvironment and promotes an immunosuppressive state by changing the levels of macro- and micronutrients and by releasing hormones and cytokines that recruit immunosuppressive immune cells. Novel dietary interventions such as amino acid restriction and periodic fasting mimicking diets can prevent or dampen the formation of an immunosuppressive microenvironment by acting systemically on the release of hormones and growth factors, inhibiting the release of proinflammatory cytokines, and remodeling the tumor vasculature and extracellular matrix. Here, we discuss the latest research on the effects of these therapeutic interventions on immunometabolism and tumor immune response and future scenarios pertaining to how dietary interventions could contribute to cancer therapy.

Diosmin exerts hepatoprotective and antihyperglycemic effects against sodium arsenite-induced toxicity through the modulation of oxidative stress and inflammation in mice

BACKGROUND

Chronic exposure to high concentrations of inorganic arsenic (NaAsO₂) in drinking water is related to an increase in the risk of liver toxicity and diabetes. Diosmin has various pharmacological properties, including antioxidant and anti-inflammatory properties. This study was designed to investigate the protective effects of diosmin on diabetes and hepatotoxicity caused by NaAsO₂.

METHODS

Sixty male 8-week-old NMRI mice, weighing 25 ± 2 g, were randomly selected and put into six groups. The control (Group 1) was treated orally with distilled water, group 2 was treated with diosmin (100 mg/kg, p.o), group 3 received NaAsO₂ (10 mg/kg, p.o), and groups 4, 5, 6 received diosmin (25, 50, 100 mg/kg, p.o), respectively and NaAsO₂ (10 mg/kg, p.o). After 29 days, fasting blood sugar (FBS) measurement and glucose tolerance test were done. The mice were sacrificed on day 31, and blood and tissue (liver and pancreas) samples were taken. Then, serum and tissue samples were studied for biochemical and histological evaluations.

RESULTS

The results demonstrated that diosmin ameliorated glucose intolerance and decreased FBS compared to the NaAsO₂ group. Diosmin (50 and 100 mg/kg) improved the serum factors of liver function (alanine aminotransferase, aspartate transaminase, and alkaline phosphatase) in the groups receiving NaAsO₂. Moreover, increased levels of nitric oxide, tumor necrosis factor-alpha, and thiobarbituric acid reactive substances in liver tissue induced by NaAsO₂ were diminished by diosmin treatment. Administration of diosmin increased total thiol and enzymatic activities of catalase, superoxide dismutase, and glutathione peroxidase in liver tissue. Furthermore, treatment with diosmin reduced the increase in protein amount of Sirtuin 3 and nuclear factor kappa B in the groups receiving NaAsO₂. Also, the liver and pancreas histological lesions induced by NaAsO₂ were attenuated by diosmin treatment.

CONCLUSION

Diosmin has a preventive effect against hepatotoxicity and diabetes induced by NaAsO₂ in mice through its antioxidant and anti-inflammatory properties.

In silico evaluation of geroprotective phytochemicals as potential sirtuin 1 interactors

Sirtuin 1 (SIRT1) belongs to the histone deacetylase enzyme family and its activity regulates various signaling networks associated with aging. SIRT1 is widely involved in a large number of biological processes, including senescence, autophagy, inflammation, and oxidative stress. In addition, SIRT1 activation may improve lifespan and health in numerous experimental models. Therefore, SIRT1 targeting is a potential strategy to delay or reverse aging and age-related diseases. Although SIRT1 is activated by a wide array of small molecules, only a limited number of phytochemicals that directly interact with SIRT1 have been identified. Using the Geroprotectors.org database and a literature search, the aim of this study was to identify geroprotective phytochemicals that might interact with SIRT1. We performed molecular docking, density functional theory studies, molecular dynamic simulations (MDS), and absorption, distribution, metabolism, excretion, and toxicity (ADMET) prediction to screen potential candidates against SIRT1. After the initial screening of 70 phytochemicals, crocin, celastrol, hesperidin, taxifolin, vitexin, and quercetin had significant binding affinity scores. These six compounds established multiple hydrogen-bonding and hydrophobic interactions with SIRT1 and showed good drug-likeness and ADMET properties. In particular, crocin was further analyzed using MDS to study its complex with SIRT1 during simulation. Crocin has a high reactivity to SIRT1 and can form a stable complex with it, showing a good ability to fit into the binding pocket. Although further investigations are required, our results suggest that these geroprotective phytochemicals, especially crocin, are novel interacting partners of SIRT1.

Brain histone beta-hydroxybutyrylation couples metabolism with gene expression

Little is known about the impact of metabolic stimuli on brain tissue at a molecular level. The ketone body beta-hydroxybutyrate (BHB) can be a signaling molecule regulating gene transcription. Thus, we assessed lysine beta-hydroxybutyrylation (K-bhb) levels in proteins extracted from the cerebral cortex of mice undergoing a ketogenic metabolic challenge (48 h fasting). We found that fasting enhanced K-bhb in a variety of proteins including histone H3. ChIP-seq experiments showed that K9 beta-hydroxybutyrylation of H3 (H3K9-bhb) was significantly enriched by fasting on more than 8000 DNA loci. Transcriptomic analysis showed that H3K9-bhb on enhancers and promoters correlated with active gene expression. One of the most enriched functional annotations both at the epigenetic and transcriptional level was "circadian rhythms''. Indeed, we found that the diurnal oscillation of specific transcripts was modulated by fasting at distinct zeitgeber times both in the cortex and suprachiasmatic nucleus. Moreover, specific changes in locomotor activity daily features were observed during re-feeding after 48-h fasting. Thus, our results suggest that fasting remarkably impinges on the cerebral cortex transcriptional and epigenetic landscape, and BHB acts as a powerful epigenetic molecule in the brain through direct and specific histone marks remodeling in neural tissue cells.

Mitochondrial function and nutrient sensing pathways in ageing: enhancing longevity through dietary interventions

Ageing is accompanied by alterations in several biochemical processes, highly influenced by its environment. It is controlled by the interactions at various levels of biological hierarchy. To maintain homeostasis, a number of nutrient sensors respond to the nutritional status of the cell and control its energy metabolism. Mitochondrial physiology is influenced by the energy status of the cell. The alterations in mitochondrial physiology and the network of nutrient sensors result in mitochondrial damage leading to age related metabolic degeneration and diseases. Calorie restriction (CR) has proved to be as the most successful intervention to achieve the goal of longevity and healthspan. CR elicits a hormetic response and regulates metabolism by modulating these networks. In this review, the authors summarize the interdependent relationship between mitochondrial physiology and nutrient sensors during the ageing process and their role in regulating metabolism.

HeLa Cervical Cancer Cells Are Maintained by Nephronophthisis 3-Associated Primary Cilium Formation via ROS-Induced ERK and HIF-1α Activation under Serum-Deprived Normoxic Condition

The primary cilium (PC) is a microtubule-based antenna-like organelle projecting from the surface of the cell membrane. We previously reported that PC formation could be regulated by nephronophthisis 3 (NPHP3) expression followed by its interaction with thymosin β4. Here, we investigated whether cancer cell viability is regulated by NPHP3-mediated PC formation. The total and viable cell number were reduced by incubating cells under serum deprivation (SD) without fetal bovine serum (-FBS). PC frequency was increased by SD which enhanced NPHP3 expression and hypoxia inducible factor (HIF)-1α. The role of HIF-1α on NPHP3 expression and PC formation was confirmed by the binding of HIF-1α to the NPHP3 promoter and siRNA-based inhibition of HIF-1α (siHIF-1α), respectively. HIF-1α-stabilizing dimethyloxallyl glycine (DMOG) and hypoxic conditions increased NPHP3 expression and PC formation. In addition, as SD elevated the reactive oxygen species (ROS), PC frequency and NPHP3 expression were inhibited by a treatment with N-acetylcysteine (NAC), a ROS scavenger. PC formation was increased by H₂O₂ treatment, which was inhibited by siHIF-1α. The inhibition of ERK with P98059 decreased the frequency of PC formation and NPHP3 expression. Cell viability was reduced by a treatment with ciliobrevin A (CilioA) to inhibit PC formation, which was re-affirmed by using PC-deficient IFT88^-/- cells. Taken together, the results imply that PC formation in cancer cells could be controlled by NPHP3 expression through ROS-induced HIF-1α and ERK activation under SD conditions. It suggests that cancer cell viability under SD conditions could be maintained by NPHP3 expression to regulate PC formation.

Methionine restriction - Association with redox homeostasis and implications on aging and diseases

Methionine is an essential amino acid, involved in the promotion of growth, immunity, and regulation of energy metabolism. Over the decades, research has long focused on the beneficial effects of methionine supplementation, while data on positive effects of methionine restriction (MR) were first published in 1993. MR is a low-methionine dietary intervention that has been reported to ameliorate aging and aging-related health concomitants and diseases, such as obesity, type 2 diabetes, and cognitive disorders. In addition, MR seems to be an approach to prolong lifespan which has been validated extensively in various animal models, such as Caenorhabditis elegans, Drosophila, yeast, and murine models. MR appears to be associated with a reduction in oxidative stress via so far mainly undiscovered mechanisms, and these changes in redox status appear to be one of the underlying mechanisms for lifespan extension and beneficial health effects. In the present review, the association of methionine metabolism pathways with redox homeostasis is described. In addition, the effects of MR on lifespan, age-related implications, comorbidities, and diseases are discussed.

Crosstalk between Oxidative Stress and Exosomes

Mammals have several organs comprising various cells with different functions. Furthermore, eukaryotic cells are compartmentalized into functionally distinct organelles. Thus, for good organismal health, exosomes, which play an important role in cell-to-cell communication, interact closely with oxidative stress. Oxidative stress, which is recognized as a type of intracellular second signal, is aggravated by reactive species. As a subtype of reactive species, reactive oxygen species (ROS) can be produced on the extracellular face of the plasma membrane by NADPH oxidases, via the mitochondrial electron transport chain, in peroxisomes, and in the lumen of the endoplasmic reticulum. The scavenging of ROS is mainly dependent on peroxiredoxins, including GSH peroxidases, peroxiredoxins 3 and 5, and thioredoxin reductase. Intracellular ROS increase the number of intracellular multivesicular bodies (MVBs) by restraining their degradation in lysosomes, thereby enhancing the release of exosomes under the synergy of the depletion of exofacial GSH, which can be regulated by oxidative stress. In contrast, higher ROS levels can decrease the yield of exosomes by activating cellular autophagy to degrade MVBs. Moreover, exosomes can transfer the characteristics of parent cells to recipient cells. Here, we review the interaction between oxidative stress and exosomes in the hope of providing insights into their interplay.

Preoperative Naples prognostic score is a reliable prognostic indicator for newly diagnosed glioblastoma patients

Background

Glioblastoma (GBM) accounts for approximately 80% of malignant gliomas and is characterized by considerable cellularity and mitotic activity, vascular proliferation, and necrosis. Naples prognostic score (NPS), based on inflammatory markers and nutritional status, has a prognostic ability in various cancers. In the current study, we aim to explore the prognostic value of operative NPS in GBM patients and compare the prognostic ability between NPS and controlling nutritional status (CONUT).

Materials and methods

The retrospective analysis was carried out on consecutive newly diagnosed GBM patients who had underwent tumor resection at West China Hospital from February 2016 to March 2019. All statistical analyses were conducted using SPSS software and R software.

Results

A total of 276 newly diagnosed GBM patients were enrolled in the current study. Overall survival (OS) (p < 0.001) and tumor location (p = 0.007) were significantly related to NPS. Serum albumin concentrate, cholesterol concentrate, neutrophil-to-lymphocyte ratio, lymphocyte ratio, and CONUT score were all significantly associated with NPS (p < 0.001). The Kaplan–Meier curve indicated that NPS (log-rank test, p < 0.001) and CONUT score (log-rank test, p = 0.023) were significantly associated with OS. Multivariate Cox regression revealed that both NPS and CONUT score served as independent prognostic indicators. The prognostic model with NPS had the strongest prognostic capability and best model-fitting.

Conclusion

In the current study, NPS is found as an independent prognostic indicator for patients with newly diagnosed GBM, and the prognostic ability of NPS is superior to CONUT score.

Arginine Enhances Ovarian Antioxidant Capability via Nrf2/Keap1 Pathway during the Luteal Phase in Ewes

This study evaluated the effect of arginine (Arg) on ovarian antioxidant capability during the luteal phase in ewes. A total of 108 multiparous Hu sheep at two years of age were randomly allocated to three groups: a control group (CG), a restriction group (RG), and an Arg group (AG), with six replicates per group and six ewes per replicate. Our results showed that the end body weight was significantly decreased in the RG group (p < 0.05), while the Arg addition reversed this reduction. The estrous cycle days were significantly increased in the RG group (p < 0.05), while Arg addition reversed this time extension. Compared with the control group, restricting feeding could significantly enhance the number of small follicles (SF), total follicles (TF), large corpora lutea, and the SF/TF (p < 0.05), while Arg addition reduced the number of SF and TF. However, the large follicles/TF were significantly decreased (p < 0.05), while Arg addition reversed this reduction. In addition, nutrition restriction significantly increased the malondialdehyde (MDA) level (p < 0.05), while significantly decreased the glutathione/glutathione disulfide and the activities of superoxidative dismutase, catalase, and glutathione peroxidase in the ovaries (p < 0.05). However, Arg addition reversed this enhancement of the MDA level and the reductions in these antioxidant enzymes activities. In addition, positive relationships occurred between antioxidant enzyme activities and the enzyme mRNA expressions. Meanwhile, the nuclear factor erythroid 2-related factor 2 (Nrf2) mRNA expression was positively connected with antioxidant mRNA expressions and negatively related to the Kelch-like ECH-associated protein 1 (Keap1) mRNA expression. The Nrf2 protein expression was negatively related to the Keap1 protein expression. In conclusion, nutrition restriction reduced the ovarian antioxidant capability in ewes, while this was significantly improved by Arg supplementation, which was associated with the Nrf2/Keap1 pathway.

Roles of stress response-related signaling and its contribution to the toxicity of zearalenone in mammals

Zearalenone (ZEA) is a mycotoxin frequently found in cereal crops and cereal-derived foodstuffs worldwide. It affects plant productivity, and is also a serious hazard to humans and animals if being exposed to food/feed contaminated by ZEA. Studies over the last decade have shown that the toxicity of ZEA in animals is mainly mediated by the various stress responses, such as endoplasmic reticulum (ER) stress, oxidative stress, and others. Accumulating evidence shows that oxidative stress and ER stress signaling are actively implicated in and contributes to the pathophysiology of various diseases. Biochemically, the deleterious effects of ZEA are associated with apoptosis, DNA damage, and lipid peroxidation by regulating the expression of genes implicated in these biological processes. Despite these findings, the underlying mechanisms responsible for these alterations remain unclear. This review summarized the characteristics, metabolism, toxicity and the deleterious effects of ZEA exposure in various tissues of animals. Stress response signaling implicated in the toxicity as well as potential therapeutic options with the ability to reduce the deleterious effects of ZEA in animals were highlighted and discussed.

The Association of Nutritional Risk Screening 2002 With 1-Year Re-hospitalization and the Length of Initial Hospital Stay in Patients With Heart Failure

Backgrounds and Aims

Nutritional Risk Screening 2002 (NRS-2002) has been widely recommended for identifying the nutritional risk. However, the association between NRS-2002 and the prognosis of heart failure has not been fully addressed. This study aimed to explore the association of NRS-2002 with 1-year re-hospitalization and the length of initial hospital stay in heart failure patients.

Methods

This retrospective study included 2,830 heart failure patients. The primary endpoint was 1-year re-hospitalization for heart failure. The secondary endpoint was the length of initial hospital stay. The Log-binomial regression analysis was performed to determine the association between NRS-2002 and re-hospitalization. The Cox regression model was fitted to estimate hazard of discharge. The cumulative incidence curves of discharge were plotted using Kaplan–Meier method and log-rank test was performed. Exploratory analysis was also conducted according to the classification of heart failure and the level of N-terminal pro-B-type natriuretic peptide (NT-proBNP) fold-elevation.

Results

Among 2,830 heart failure patients, the mean age was 64.3 years and 66.4% were male. A total of 122 (4.3%) patients were considered at high nutritional risk. Log-binomial regression analysis demonstrated that higher NRS-2002 score was an independent risk factor of re-hospitalization ([1 vs. 0]: relative risks [RR] = 1.383, 95% CI = 1.152 to 1.660; [2 vs. 0]: RR = 1.425, 95% CI = 1.108 to 1.832; [3–7 vs. 0]: RR = 1.770, 95% CI = 1.310 to 2.393). Kaplan–Meier curve showed that the cumulative incidence of discharge was lower in high nutritional risk group (Log rank p &lt; 0.001). Cox regression analysis also found that higher NRS-2002 score (2 or ≥3) was strongly associated with longer length of initial hospital stay ([2 vs. 0]: Hazard ratios [HR] = 0.854, 95% CI = 0.748 to 0.976; [3–7 vs. 0]: HR = 0.609, 95% CI = 0.503 to 0.737). Exploratory analysis showed that such association still remained irrespective of NT-proBNP fold-elevation, but only existed in patients with heart failure with preserved ejection fraction (HFpEF).

Conclusion

In patients with heart failure, high NRS-2002 score was strongly and independently associated with the incidence of 1-year re-hospitalization and the length of initial hospital stay.

Current studies and potential future research directions on biological effects and related mechanisms of allicin

Allicin, a thiosulfonate extract from freshly minced garlic, has been reported to have various biological effects on different organs and systems of animals and human. It can reduce oxidative stress, inhibit inflammatory response, resist pathogen infection and regulate intestinal flora. In addition, dozens of studies also demonstrated allicin could reduce blood glucose level, protect cardiovascular system and nervous system, and fight against cancers. Allicin was widely used in disease prevention and health care. However, more investigations on human cohort study are needed to verify the biological or clinical effects of allicin in the future. In this review, we summarized the biological effects of allicin from previous outstanding and valuable studies and provided useful information for future studies on the health effects of allicin.

Effect of Lycopene on the Growth Performance, Antioxidant Enzyme Activity, and Expression of Gene in the Keap1-Nrf2 Signaling Pathway of Arbor Acres Broilers

The objective of this study was to determine the effect of dietary lycopene supplementation on the growth performance, antioxidant enzyme activity of serum and liver, and gene expressions associated with Kelch-like ech-associated protein-1 (Keap1)/Nuclear Factor E2-related factor 2 (Nrf2) pathway in liver of Arbor Acres broilers. A total of 288 1-day-old male broilers were randomly divided into 4 treatments with 6 replicates and 12 chickens for each replicate. The control group was fed with the basal diet, while the treated groups were fed with the basal diet with 10, 20, and 30 mg/kg lycopene in powder. Feed and water were provided ad libitum for 42 days. Compared with the control group, (a) the average daily gain increased (p = 0.002 vs. p = 0.001) and the feed conversion ratio decreased (p = 0.017 vs. p = 0.023) in groups treated with lycopene in the grower and whole phases, and the average daily feed intake was quadratically affected (p = 0.043) by lycopene in the grower phase; (b) the serum superoxide dismutase content was linearly affected (p = 0.035) by lycopene at 21 days; (c) the serum glutathione peroxidase content, superoxide dismutase content, and total antioxidant capability were higher (p = 0.014, p = 0.003, and p = 0.016, respectively) in the 30 mg/kg lycopene group at 42 days; (d) the liver glutathione peroxidase and superoxide dismutase contents in groups treated with lycopene were higher (p ≤ 0.001 vs. p ≤ 0.001) at 21 days; (e) the liver glutathione peroxidase content was higher (p ≤ 0.001) in the 20 and 30 mg/kg lycopene groups, at 42 days; (f) the mRNA expression levels of Nrf2, superoxide dismutase 2, NAD(P)H quinone dehydrogenase 1, and heme oxygenase 1 genes were higher (21 days: p = 0.042, p = 0.021, p = 0.035, and p = 0.043, respectively; 42 days: p = 0.038, p = 0.025, p = 0.034, and p = 0.043, respectively) in the 20 and 30 mg/kg lycopene groups at 21 and 42 days. The 30 mg/kg lycopene concentration improved the growth performance, antioxidant enzyme activity in serum and liver, and gene expression in the Keap1-Nrf2 signaling pathway of Arbor Acres broilers.

Mild calorie restriction, but not 17α-estradiol, extends ovarian reserve and fertility in female mice

Calorie restriction (CR) (25-40%) is the most commonly studied strategy for curtailing age-related disease and has also been found to extend reproductive lifespan in female mice. However, the effects of mild CR (10%), which is sustainable, on ovarian aging has not yet been addressed. 17α-estradiol (17α-E2) is another intervention shown to positively modulate healthspan and lifespan in mice but its effects on female reproduction remain unclear. We evaluated the effects of mild CR (10%) and 17α-E2 treatment on ovarian reserve and female fertility over a 24-week period, and compared these effects with the more commonly employed 30% CR regimen. Both 10% and 30% CR elicited positive effects on the preservation of ovarian reserve, whereas 17α-E2 did not alter parameters associated with ovarian function. Following refeeding, both 10% and 30% increased fertility as evidenced by greater pregnancy rates. In aligned with the ovarian reserve data, 17α-E2 also failed to improve fertility. Collectively, these data indicate that 10% CR is effective in preserving ovarian function and fertility, while 17α-E2 does not appear to have therapeutic potential for delaying ovarian aging.

Calorie Restriction for Cancer Prevention and Therapy: Mechanisms, Expectations, and Efficacy

Cancer is one of the most frequently diagnosed diseases, and despite the continuous efforts in searching for new and more effective treatments, its morbidity and mortality remain a significant health problem worldwide. Calorie restriction, a dietary manipulation that consists in a reduction of the calorie intake, is gaining attention as a potential adjuvant intervention for preventing and/or fighting cancer. Several forms of energy reduction intake, which includes caloric restriction tout-court, dietary restrictions, and intermittent fasting, are being explored for their ability to prevent or slow down cancer progression. Additionally, another anti-cancer approach being under investigation relies on the use of nutraceuticals known as “Caloric Restriction Mimetics” that can provide caloric restriction-mediated benefits without subjecting the patients to a strict diet. Preclinical in vitro and in vivo studies consistently show that diet modifiers reducing the calorie have impact on tumor microenvironment and cancer metabolism, resulting in reduced growth and progression of cancer. Preliminary clinical studies show that patients subjected to a reduced nutrient/energy intake experience improved outcomes from chemo- and radiotherapy while better tolerating the side effects. Here, we review the state of the art on the therapeutic potential of calorie restriction and of caloric restriction mimetics in preventing or retarding tumor development by modulating a subset of cellular processes. The most recent clinical progresses with caloric restriction mimetics in the clinical practice are also discussed.

Preventing Oxidative Stress in the Liver: An Opportunity for GLP-1 and/or PASK

The liver’s high metabolic activity and detoxification functions generate reactive oxygen species, mainly through oxidative phosphorylation in the mitochondria of hepatocytes. In contrast, it also has a potent antioxidant mechanism for counterbalancing the oxidant’s effect and relieving oxidative stress. PAS kinase (PASK) is a serine/threonine kinase containing an N-terminal Per-Arnt-Sim (PAS) domain, able to detect redox state. During fasting/feeding changes, PASK regulates the expression and activation of critical liver proteins involved in carbohydrate and lipid metabolism and mitochondrial biogenesis. Interestingly, the functional inactivation of PASK prevents the development of a high-fat diet (HFD)-induced obesity and diabetes. In addition, PASK deficiency alters the activity of other nutrient sensors, such as the AMP-activated protein kinase (AMPK) and the mammalian target of rapamycin (mTOR). In addition to the expression and subcellular localization of nicotinamide-dependent histone deacetylases (SIRTs). This review focuses on the relationship between oxidative stress, PASK, and other nutrient sensors, updating the limited knowledge on the role of PASK in the antioxidant response. We also comment on glucagon-like peptide 1 (GLP-1) and its collaboration with PASK in preventing the damage associated with hepatic oxidative stress. The current knowledge would suggest that PASK inhibition and/or exendin-4 treatment, especially under fasting conditions, could ameliorate disorders associated with excess oxidative stress.

Reactive-oxygen-species-scavenging nanomaterials for resolving inflammation

Reactive oxygen species (ROS) mediate multiple physiological functions; however, the over-accumulation of ROS causes premature aging and/or death and is associated with various inflammatory conditions. Nevertheless, there are limited clinical treatment options that are currently available. The good news is that owing to the considerable advances in nanoscience, multiple types of nanomaterials with unique ROS-scavenging abilities that influence the temporospatial dynamic behaviors of ROS in biological systems have been developed. This has led to the emergence of next-generation nanomaterial-controlled strategies aimed at ameliorating ROS-related inflammatory conditions. Accordingly, herein we reviewed recent progress in research on nanotherapy based on ROS scavenging. The underlying mechanisms of the employed nanomaterials are emphasized. Furthermore, important issues in developing cross-disciplinary nanomedicine-based strategies for ROS-based inflammatory conditions are discussed. Our review of this increasing interdisciplinary field will benefit ongoing studies and clinical applications of nanomedicine based on ROS scavenging.

SIRT3-mediated deacetylation of NLRC4 promotes inflammasome activation

Salmonella typhimurium (S. typhimurium) infection of macrophage induces NLRC4 inflammasome-mediated production of the pro-inflammatory cytokines IL-1β. Post-translational modifications on NLRC4 are critical for its activation. Sirtuin3 (SIRT3) is the most thoroughly studied mitochondrial nicotinamide adenine dinucleotide (NAD+) -dependent deacetylase. We wondered whether SIRT3 mediated-deacetylation could take part in NLRC4 inflammasome activation. Methods: We initially tested IL-1β production and pyroptosis after cytosolic transfection of flagellin or S. typhimurium infection in wild type and SIRT3-deficient primary peritoneal macrophages via immunoblotting and ELISA assay. These results were confirmed in SIRT3-deficient immortalized bone marrow derived macrophages (iBMDMs) which were generated by CRISPR-Cas9 technology. In addition, in vivo experiments were conducted to confirm the role of SIRT3 in S. typhimurium-induced cytokines production. Then NLRC4 assembly was analyzed by immune-fluorescence assay and ASC oligomerization assay. Immunoblotting, ELISA and flow cytometry were performed to clarify the role of SIRT3 in NLRP3 and AIM2 inflammasomes activation. To further investigate the mechanism of SIRT3 in NLRC4 activation, co-immunoprecipitation (Co-IP), we did immunoblot, cellular fractionation and in-vitro deacetylation assay. Finally, to clarify the acetylation sites of NLRC4, we performed liquid chromatography-mass spectrometry (LC-MS) and immunoblotting analysis. Results: SIRT3 deficiency led to significantly impaired NLRC4 inflammasome activation and pyroptosis both in vitro and in vivo. Furthermore, SIRT3 promotes NLRC4 inflammasome assembly by inducing more ASC speck formation and ASC oligomerization. However, SIRT3 is dispensable for NLRP3 and AIM2 inflammasome activation. Moreover, SIRT3 interacts with and deacetylates NLRC4 to promote its activation. Finally, we proved that deacetylation of NLRC4 at Lys71 or Lys272 could promote its activation. Conclusions: Our study reveals that SIRT3 mediated-deacetylation of NLRC4 is pivotal for NLRC4 activation and the acetylation switch of NLRC4 may aid the clearance of S. typhimurium infection.

Dietary Restriction and Oxidative Stress: Friends or Enemies?

Significance: It is well established that lifestyle and dietary habits have a tremendous impact on life span, the rate of aging, and the onset/progression of age-related diseases. Specifically, dietary restriction (DR) and other healthy dietary patterns are usually accompanied by physical activity and differ from Western diet that is rich in fat and sugars. Moreover, as the generation of reactive oxidative species is the major causative factor of aging, while DR could modify the level of oxidative stress, it has been proposed that DR increases both survival and longevity. Recent Advances: Despite the documented links between DR, aging, and oxidative stress, many issues remain to be addressed. For instance, the free radical theory of aging is under "re-evaluation," while DR as a golden standard for prolonging life span and ameliorating the effects of aging is also under debate. Critical Issues: This review article pays special attention to highlight the link between DR and oxidative stress in both aging and age-related diseases. We discuss in particular DR's capability to counteract the consequences of oxidative stress and the molecular mechanisms involved in these processes. Future Directions: Although DR is undoubtedly beneficial, several considerations must be taken into account when designing the best dietary intervention. Use of intermittent fasting, daily food reduction, or DR mimetics? Future research should unravel the pros and cons of all these processes. Antioxid. Redox Signal. 34, 421-438.

The Role of Natural Antioxidants in the Prevention of Dementia-Where Do We Stand and Future Perspectives

Dementia, and especially Alzheimer's disease (AD), puts significant burden on global healthcare expenditure through its increasing prevalence. Research has convincingly demonstrated the implication of oxidative stress in the pathogenesis of dementia as well as of the conditions which increase the risk of developing dementia. However, drugs which target single pathways have so far failed in providing significant neuroprotection. Natural antioxidants, due to their effects in multiple pathways through which oxidative stress leads to neurodegeneration and triggers neuroinflammation, could prove valuable weapons in our fight against dementia. Although efficient in vitro and in animal models of AD, natural antioxidants in human trials have many drawbacks related to the limited bioavailability, unknown optimal dose, or proper timing of the treatment. Nonetheless, trials evaluating several of these natural compounds are ongoing, as are attempts to modify these compounds to achieve improved bioavailability.

2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine Induced Colon Injury by Disrupting the Intestinal Bacterial Composition and Lipid Metabolic Pathways in Rats

2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), one of the most abundant heterocyclic amines, is a common carcinogen produced in thermally processed protein-rich foods. Studies have demonstrated that PhIP could induce colon tumors in rodents, leaving mechanisms uncovered. This study aims to investigate the mechanism of PhIP-induced colon injury in a rat model. The results of 16S rRNA gene sequencing and metabolomics showed that PhIP disrupted intestinal bacterial composition and affected the glycerophospholipid metabolism and linoleic acid metabolism. Simultaneously, the lipid metabolism function in the intestinal flora was inhibited by PhIP. Notably, transcriptomics revealed that PhIP remarkably inhibited the expression of gene sets associated with steroid hormone biosynthesis, fatty acid elongation, fatty acid degradation, and glycerolipid metabolism pathways in the colon. The results provide new perspectives to study the mechanism of PhIP-induced colon injury and theoretical bases for further understanding the toxicity of PhIP.

Age-related alteration in HNE elimination enzymes

4-hydroxynonenal (HNE, 4-hydroxy-2-nonenal) is a primary α,β-unsaturated aldehyde product of lipid peroxidation. The accumulation of HNE increases with aging and the mechanisms are mainly attributable to increased oxidative stress and decreased capacity of HNE elimination. In this review article, we summarize the studies on age-related change of HNE concentration and alteration of HNE metabolizing enzymes (GCL, GST, ALDHs, aldose reductase, and 20S-proteasome), and discuss potential mechanism of age-related decrease in HNE-elimination capacity by focusing on Nrf2 redox signaling.

Emerging potential of cannabidiol in reversing proteinopathies

The aberrant accumulation of disease-specific protein aggregates accompanying cognitive decline is a pathological hallmark of age-associated neurological disorders, also termed as proteinopathies, including Alzheimer's disease, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis and multiple sclerosis. Along with oxidative stress and neuroinflammation, disruption in protein homeostasis (proteostasis), a network that constitutes protein surveillance system, plays a pivotal role in the pathobiology of these dementia disorders. Cannabidiol (CBD), a non-psychotropic phytocannabinoid of Cannabis sativa, is known for its pleiotropic neuropharmacological effects on the central nervous system, including the ability to abate oxidative stress, neuroinflammation, and protein misfolding. Over the past years, compelling evidence has documented disease-modifying role of CBD in various preclinical and clinical models of neurological disorders, suggesting the potential therapeutic implications of CBD in these disorders. Because of its putative role in the proteostasis network in particular, CBD could be a potent modulator for reversing not only age-associated neurodegeneration but also other protein misfolding disorders. However, the current understanding is insufficient to underpin this proposition. In this review, we discuss the potentiality of CBD as a pharmacological modulator of the proteostasis network, highlighting its neuroprotective and aggregates clearing roles in the neurodegenerative disorders. We anticipate that the current effort will advance our knowledge on the implication of CBD in proteostasis network, opening up a new therapeutic window for aging proteinopathies.

Serum concentration of vitamin A and its relationship with body adiposity, oxidative stress, and cardiovascular risk in women with recommended dietary intake of vitamin A

Introduction

Background: evidence indicates a role of vitamin A in the regulation of fat mass influencing obesity and cardiovascular diseases. Material and methods: a cross-sectional study in 200 women, paired by age and by the recommended dietary intake of vitamin A. Subjects were divided into four groups according to body mass index (BMI): 80 eutrophic (E), 40 overweight (OW), 40 class I obesity (OI) and 40 class II obesity (OII). Lipid and glycemic profiles were measured and oxidative stress was evaluated through serum concentrations of uric acid, glutathione peroxidase (GSH-Px), and thiobarbituric acid reactive substances (TBARS). Results: the cutoff points for deficiency of serum retinol and β-carotene levels were < 1.05 µmol/L and 40 µg/dL, respectively. For the recommended dietary intake of vitamin A it was 700 µg/day. Retinol and β-carotene deficiency was found in the E group at 5 % and 15 %, respectively, reaching 77.5 % and 82.5 % in the OII group. Conclusions: a correlation was observed between serum concentrations of retinol and β-carotene and glycemic, lipid, and markers of oxidative stress profiles in the groups studied. It was observed that OI and OII subjects who had retinol and β-carotene deficiency presented a risk that was 16 and 20.7 times greater, respectively, of having a diagnosis with DM2 as compared to E subjects with adequate concentrations of vitamin A. Increased demand of vitamin A may be related to increased BMI, body adiposity, and oxidative stress even when a recommended intake of vitamin A is reached.

Stem Cell Metabolism and Diet

PURPOSE OF REVIEW

Diet has profound impacts on health and longevity. Evidence is emerging to suggest that diet impinges upon the metabolic pathways in tissue-specific stem cells to influence health and disease. Here, we review the similarities and differences in the metabolism of stem cells from several tissues, and highlight the mitochondrial metabolic checkpoint in stem cell maintenance and aging. We discuss how diet engages the nutrient sensing metabolic pathways and impacts stem cell maintenance. Finally, we explore the therapeutic implications of dietary and metabolic regulation of stem cells.

RECENT FINDINGS

Stem Cell transition from quiescence to proliferation is associated with a metabolic switch from glycolysis to mitochondrial OXPHOS and the mitochondrial metabolic checkpoint is critically controlled by the nutrient sensors SIRT2, SIRT3, and SIRT7 in hematopoietic stem cells. Intestine stem cell homeostasis during aging and in response to diet is critically dependent on fatty acid metabolism and ketone bodies and is influenced by the niche mediated by the nutrient sensor mTOR.

SUMMARY

Nutrient sensing metabolic pathways critically regulate stem cell maintenance during aging and in response to diet. Elucidating the molecular mechanisms underlying dietary and metabolic regulation of stem cells provides novel insights for stem cell biology and may be targeted therapeutically to reverse stem cell aging and tissue degeneration.

Tris DBA ameliorates IgA nephropathy by blunting the activating signal of NLRP3 inflammasome through SIRT1- and SIRT3-mediated autophagy induction

Tris (dibenzylideneacetone) dipalladium (Tris DBA), a small‐molecule palladium complex, can inhibit cell growth and proliferation in pancreatic cancer, lymphocytic leukaemia and multiple myeloma. Given that this compound is particularly active against B‐cell malignancies, we have been suggested that it can alleviate immune complexes (ICs)–mediated conditions, especially IgA nephropathy (IgAN). The therapeutic effects of Tris DBA on glomerular cell proliferation and renal inflammation and mechanism of action were examined in a mouse model of IgAN. Treatment of IgAN mice with Tris DBA resulted in markedly improved renal function, albuminuria and renal pathology, including glomerular cell proliferation, neutrophil infiltration, sclerosis and periglomerular inflammation in the renal interstitium, together with (Clin J Am Soc Nephrol. 2011, 6, 1301‐1307) reduced mitochondrial ROS generation; (Am J Physiol‐Renal Physiol. 2011. 301, F1218‐F1230) differentially regulated autophagy and NLRP3 inflammasome; (Clin J Am Soc Nephrol. 2012, 7, 427‐436) inhibited phosphorylation of JNK, ERK and p38 MAPK signalling pathways, and priming signal of the NLRP3 inflammasome; and (Free Radic Biol Med. 2013, 61, 285‐297) blunted NLRP3 inflammasome activation through SIRT1‐ and SIRT3‐mediated autophagy induction, in renal tissues or cultured macrophages. In conclusion, Tris DBA effectively ameliorated the mouse IgAN model and targeted signalling pathways downstream of ICs‐mediated interaction, which is a novel immunomodulatory strategy. Further development of Tris DBA as a therapeutic candidate for IgAN is warranted.

Protein Homeostasis Networks and the Use of Yeast to Guide Interventions in Alzheimer's Disease

Alzheimer's Disease (AD) is a progressive multifactorial age-related neurodegenerative disorder that causes the majority of deaths due to dementia in the elderly. Although various risk factors have been found to be associated with AD progression, the cause of the disease is still unresolved. The loss of proteostasis is one of the major causes of AD: it is evident by aggregation of misfolded proteins, lipid homeostasis disruption, accumulation of autophagic vesicles, and oxidative damage during the disease progression. Different models have been developed to study AD, one of which is a yeast model. Yeasts are simple unicellular eukaryotic cells that have provided great insights into human cell biology. Various yeast models, including unmodified and genetically modified yeasts, have been established for studying AD and have provided significant amount of information on AD pathology and potential interventions. The conservation of various human biological processes, including signal transduction, energy metabolism, protein homeostasis, stress responses, oxidative phosphorylation, vesicle trafficking, apoptosis, endocytosis, and ageing, renders yeast a fascinating, powerful model for AD. In addition, the easy manipulation of the yeast genome and availability of methods to evaluate yeast cells rapidly in high throughput technological platforms strengthen the rationale of using yeast as a model. This review focuses on the description of the proteostasis network in yeast and its comparison with the human proteostasis network. It further elaborates on the AD-associated proteostasis failure and applications of the yeast proteostasis network to understand AD pathology and its potential to guide interventions against AD.

NAD+ metabolism: pathophysiologic mechanisms and therapeutic potential

Nicotinamide adenine dinucleotide (NAD+) and its metabolites function as critical regulators to maintain physiologic processes, enabling the plastic cells to adapt to environmental changes including nutrient perturbation, genotoxic factors, circadian disorder, infection, inflammation and xenobiotics. These effects are mainly achieved by the driving effect of NAD+ on metabolic pathways as enzyme cofactors transferring hydrogen in oxidation-reduction reactions. Besides, multiple NAD+-dependent enzymes are involved in physiology either by post-synthesis chemical modification of DNA, RNA and proteins, or releasing second messenger cyclic ADP-ribose (cADPR) and NAADP+. Prolonged disequilibrium of NAD+ metabolism disturbs the physiological functions, resulting in diseases including metabolic diseases, cancer, aging and neurodegeneration disorder. In this review, we summarize recent advances in our understanding of the molecular mechanisms of NAD+-regulated physiological responses to stresses, the contribution of NAD+ deficiency to various diseases via manipulating cellular communication networks and the potential new avenues for therapeutic intervention.

Very low-calorie ketogenic diet (VLCKD) in patients with psoriasis and obesity: an update for dermatologists and nutritionists

Psoriasis is a chronic skin immune-mediated disease with systemic pro-inflammatory activation; both genetic and lifestyles factors contribute to its pathogenesis and severity. In this context, nutrition plays a significant role, per se, in psoriasis' pathogenesis. Obesity is another important risk factor for psoriasis, and weight reduction may improve psoriasis' clinical severity. The excess body weight, particularly visceral fat mass, can affect both drug's pharmacokinetics and pharmacodynamics. Therefore, psoriasis and obesity share a certain degree of synergy, and the chronic inflammatory state represents the basis of this vicious cycle. Evidence reported that nutrition has different impact on the clinical severity of psoriasis, though some specific diets have been more investigated in clinical studies compared to others. Diets with systemic anti-inflammatory properties seem to have a higher effect on improving the clinical severity of psoriasis. Of interest, very-low-calorie ketogenic diet (VLCKD), through the production of ketone bodies, has been associated with both a significant reduction of body weight and inflammatory state. VLCKD leading to both weight loss and reduction of systemic inflammation may decrease the exacerbation of the clinical manifestations or even it may block the trigger of psoriatic disease. This dietary pattern could represent a potential first-line treatment in psoriatic patients with obesity. The review aims to summarize the current evidence regarding VLCKD and psoriasis with specific reference to antioxidant and anti-inflammatory effects of this dietary pattern.

Sirtuins and their Biological Relevance in Aging and Age-Related Diseases

Sirtuins, initially described as histone deacetylases and gene silencers in yeast, are now known to have many more functions and to be much more abundant in living organisms. The increasing evidence of sirtuins in the field of ageing and age-related diseases indicates that they may provide novel targets for treating diseases associated with aging and perhaps extend human lifespan. Here, we summarize some of the recent discoveries in sirtuin biology that clearly implicate the functions of sirtuins in the regulation of aging and age-related diseases. Furthermore, human sirtuins are considered promising therapeutic targets for anti-aging and ageing-related diseases and have attracted interest in scientific communities to develop small molecule activators or drugs to ameliorate a wide range of ageing disorders. In this review, we also summarize the discovery and development status of sirtuin-targeted drug and further discuss the potential medical strategies of sirtuins in delaying aging and treating age-related diseases.

Protein and calorie restriction may improve outcomes in living kidney donors and kidney transplant recipients

Previously, we and others showed that dietary restriction protects against renal ischemia-reperfusion injury in animals. However, clinical translation of preoperative diets is scarce, and in the setting of kidney transplantation these data are lacking. In this pilot study, we investigated the effects of five days of a preoperative protein and caloric dietary restriction (PCR) diet in living kidney donors on the perioperative effects in donors, recipients and transplanted kidneys. Thirty-five kidney donors were randomized into either the PCR, 30% calorie and 80% protein reduction, or control group without restrictions. Adherence to the diet and kidney function in donors and their kidney recipients were analyzed. Perioperative kidney biopsies were taken in a selected group of transplanted kidneys for gene expression analysis. All donors adhered to the diet. From postoperative day 2 up until month 1, kidney function of donors was significantly better in the PCR-group. PCR-donor kidney recipients showed significantly improved kidney function and lower incidence of slow graft function and acute rejection. PCR inhibited cellular immune response pathways and activated stress-resistance signaling. These observations are the first to show that preoperative dietary restriction induces postoperative recovery benefits in humans and may be beneficial in clinical settings involving ischemia-reperfusion injury.

Protection against renal ischemia and reperfusion injury by short-term time-restricted feeding involves the mitochondrial unfolded protein response

Food restriction improves metabolic health and increases resistance to stress in experimental animals. However, most studies have focused on long-term dietary restriction protocols consisting of several weeks or months of limited food ingestion. Here it was investigated the impact of 2-h time-restricted feeding (TRF) for one week on stress resistance in a rat model of kidney injury induced by ischemia and reperfusion (IR). At baseline, TRF reduced blood glucose, increased β-hydroxybutyrate and improved body composition in male Wistar rats. Importantly, implementing the one-week TRF schedule before ischemia significantly improved renal function, suppressed tubular injury, prevented the activation of extracellular signal-regulated kinase 1/2 (ERK1/2) and inhibited the development of interstitial fibrosis. These benefits were related to increased antioxidant protection, reduction in dynamin-related protein 1 (DRP1)-mediated mitochondrial fragmentation and modulation of the mitochondrial unfolded protein response (UPRmt). Specifically, preoperative TRF boosted the activation of the UPRmt in the acute phase after renal IR while promoted its resolution at the stage of fibrosis. Our study indicates that dietary preconditioning by short-term TRF improves the outcome of renal IR injury, and suggests that an optimal intervention that promotes kidney protection may not necessarily require adherence to restrictive diets for prolonged periods of time.

Synchronization of the circadian clock by time-restricted feeding with progressive increasing calorie intake. Resemblances and differences regarding a sustained hypocaloric restriction

Circadian rhythms are the product of the interaction of molecular clocks and environmental signals, such as light-dark cycles and eating-fasting cycles. Several studies have demonstrated that the circadian rhythm of peripheral clocks, and behavioural and metabolic mediators are re-synchronized in rodents fed under metabolic challenges, such as hyper- or hypocaloric diets and subjected to time-restricted feeding protocols. Despite the metabolic challenge, these approaches improve the metabolic status, raising the enquiry whether removing progressively the hypocaloric challenge in a  time-restricted feeding protocol leads to metabolic benefits by the synchronizing effect. To address this issue, we compared the effects of two time-restricted feeding protocols, one involved hypocaloric intake during the entire protocol (HCT) and the other implied a progressive intake accomplishing a normocaloric intake at the end of the protocol (NCT) on several behavioural, metabolic, and molecular rhythmic parameters. We observed that the food anticipatory activity (FAA) was driven and maintained in both HCT and NCT. Resynchronization of hepatic molecular clock, free fatty acids (FFAs), and FGF21 was elicited closely by HCT and NCT. We further observed that the fasting cycles involved in both protocols promoted ketone body production, preferentially beta-hydroxybutyrate in HCT, whereas acetoacetate was favoured in NCT before access to food. These findings demonstrate that time-restricted feeding does not require a sustained calorie restriction for promoting and maintaining the synchronization of the metabolic and behavioural circadian clock, and suggest that metabolic modulators, such as FFAs and FGF21, could contribute to FAA expression.

Synchronization of the circadian clock by time-restricted feeding with progressive increasing calorie intake. Resemblances and differences regarding a sustained hypocaloric restriction

Circadian rhythms are the product of the interaction of molecular clocks and environmental signals, such as light-dark cycles and eating-fasting cycles. Several studies have demonstrated that the circadian rhythm of peripheral clocks, and behavioural and metabolic mediators are re-synchronized in rodents fed under metabolic challenges, such as hyper- or hypocaloric diets and subjected to time-restricted feeding protocols. Despite the metabolic challenge, these approaches improve the metabolic status, raising the enquiry whether removing progressively the hypocaloric challenge in a  time-restricted feeding protocol leads to metabolic benefits by the synchronizing effect. To address this issue, we compared the effects of two time-restricted feeding protocols, one involved hypocaloric intake during the entire protocol (HCT) and the other implied a progressive intake accomplishing a normocaloric intake at the end of the protocol (NCT) on several behavioural, metabolic, and molecular rhythmic parameters. We observed that the food anticipatory activity (FAA) was driven and maintained in both HCT and NCT. Resynchronization of hepatic molecular clock, free fatty acids (FFAs), and FGF21 was elicited closely by HCT and NCT. We further observed that the fasting cycles involved in both protocols promoted ketone body production, preferentially beta-hydroxybutyrate in HCT, whereas acetoacetate was favoured in NCT before access to food. These findings demonstrate that time-restricted feeding does not require a sustained calorie restriction for promoting and maintaining the synchronization of the metabolic and behavioural circadian clock, and suggest that metabolic modulators, such as FFAs and FGF21, could contribute to FAA expression.

The mitochondrial metabolic checkpoint in stem cell aging and rejuvenation

Stem cell aging contributes to aging-associated tissue degeneration and dysfunction. Recent studies reveal a mitochondrial metabolic checkpoint that regulates stem cell quiescence and maintenance, and dysregulation of the checkpoint leads to functional deterioration of aged stem cells. Here, we present the evidence supporting the mitochondrial metabolic checkpoint regulating stem cell aging and demonstrating the feasibility to target this checkpoint to reverse stem cell aging. We discuss the mechanisms by which mitochondrial stress leads to stem cell deterioration. We speculate the therapeutic potential of targeting the mitochondrial metabolic checkpoint for rejuvenating aged stem cells and improving aging tissue functions.