Prolonging healthy aging: Longevity vitamins and proteins

Biogenesis of the peptide-derived redox cofactor pyrroloquinoline quinone

Pyrroloquinoline quinone (PQQ) is a peptide-derived redox cofactor produced by prokaryotes that also plays beneficial roles in organisms from other kingdoms. We review recent developments on the pathway of PQQ biogenesis, focusing on the mechanisms of PqqE, PqqF/G, and PqqB. These advances may shed light on other, uncharacterized biosynthetic pathways.

Reflections of an aging free radical

In this mini-reflection, I explain how during my doctoral work in a Botany Department I first became interested in H2O2 and later in my career in other reactive oxygen species, especially the role of "catalytic" iron and haem compounds (including leghaemoglobin) in promoting oxidative damage. The important roles that H2O2, other ROS and dietary plants play in respect to humans are discussed. I also review the roles of diet-derived antioxidants in relation to human disease, presenting reasons why clinical trials using high doses of natural antioxidants have generally given disappointing results. Iron chelators and ergothioneine are reviewed as potential cytoprotective agents with antioxidant properties that may be useful therapeutically. The discovery of ferroptosis may also lead to novel agents that can be used to treat certain diseases.

Dietary carotenoids related to risk of incident Alzheimer dementia (AD) and brain AD neuropathology: a community-based cohort of older adults

BACKGROUND

Studies have reported a protective relation to cognitive decline with long-term intake of total and individual dietary carotenoids. However, the underlying mechanisms have not yet been clearly established in humans.

OBJECTIVES

To evaluate the prospective association between intakes of total and individual carotenoids and risk of incident Alzheimer dementia (AD) and explore the underlying neuropathological basis.

METHODS

Among 927 participants from the Rush Memory and Aging Project who were free from AD at baseline and were followed up for a mean of 7 y, we estimated HRs for AD using Cox proportional hazards models by intakes of energy-adjusted carotenoids. Brain AD neuropathology was assessed in postmortem brain autopsies among 508 deceased participants. We used linear regression to assess the association of carotenoid intake with AD-related neuropathology.

RESULTS

Higher intake of total carotenoids was associated with substantially lower hazard of AD after controlling for age, sex, education, ApoE-ε4, participation in cognitively stimulating activities, and physical activity level. Comparing the top and bottom quintiles (median intake: 24.8 compared with 6.7 mg/d) of total carotenoids, the multivariate HR (95% CI) was 0.52 (0.33, 0.81), P-trend < 0.01. A similar association was observed for lutein-zeaxanthin, a weaker linear inverse association was observed for β-carotene, and a marginally significant linear inverse association was found for β-cryptoxanthin. Among the deceased participants, consumers of higher total carotenoids (top compared with bottom tertile, 18.2 compared with 8.2 mg/d) had less global AD pathology (b: -0.10; SE = 0.04; P-trend = 0.01). For individual carotenoids, lutein-zeaxanthin and lycopene were inversely associated with brain global pathology, whereas lutein-zeaxanthin showed additional inverse associations with AD diagnostic score, neuritic plaque severity, and neurofibrillary tangle density and severity.

CONCLUSIONS

Our findings support a beneficial role of total carotenoid consumption, in particular lutein/zeaxanthin, on AD incidence that may be related to the inhibition of brain β-amyloid deposition and fibril formation.

Is ergothioneine a 'longevity vitamin' limited in the American diet?

There is mounting evidence for the potential for the natural dietary antioxidant and anti-inflammatory amino acid l-Ergothioneine (ERGO) to prevent or mitigate chronic diseases of aging. This has led to the suggestion that it could be considered a 'longevity vitamin.' ERGO is produced in nature only by certain fungi and a few other microbes. Mushrooms are, by far, the leading dietary source of ERGO, but it is found in small amounts throughout the food chain, most likely due to soil-borne fungi passing it on to plants. Because some common agricultural practices can disrupt beneficial fungus-plant root relationships, ERGO levels in foods grown under those conditions could be compromised. Thus, research is needed to further analyse the role agricultural practices play in the availability of ERGO in the human diet and its potential to improve our long-term health.

Reexamination of the Ergothioneine Biosynthetic Methyltransferase EgtD from Mycobacterium tuberculosis as a Protein Kinase Substrate

Ergothioneine has emerged as a crucial cytoprotectant in the pathogenic lifestyle of Mycobacterium tuberculosis. Production of this antioxidant from primary metabolites may be regulated by phosphorylation of Thr213 in the active site of the methyltransferase EgtD. The structure of mycobacterial EgtD suggests that this post-translational modification would require a large-scale change in conformation to make the active-site residue accessible to a protein kinase. In this report, we show that, under in vitro conditions, EgtD is not a substrate of protein kinase PknD.

Oxidative stress and mitochondrial dysfunction in early-onset and late-onset preeclampsia

Preeclampsia is a pregnancy-specific syndrome with multisystem involvement which leads to foetal, neonatal, and maternal morbidity and mortality. This syndrome is characterized by the onset of clinical signs and symptoms and delivery before (early-onset preeclampsia, eoPE), or after (late-onset preeclampsia, loPE), the 34 weeks of gestation. Preeclampsia is a mitochondrial disorder where its differential involvement in eoPE and loPE is unclear. Mitochondria regulate cell metabolism and are a significant source of reactive oxygen species (ROS). The syncytiotrophoblast in eoPE and loPE show altered mitochondrial structure and function resulting in ROS overproduction, oxidative stress, and cell damage and death. Mitochondrial dysfunction in eoPE may result from altered expression of several molecules, including dynamin-related protein 1 and mitofusins, compared with loPE where these factors are either reduced or unaltered. Equally, mitochondrial fusion/fission dynamics seem differentially modulated in eoPE and loPE. It is unclear whether the electron transport chain and oxidative phosphorylation are differentially altered in these two subgroups of preeclampsia. However, the activity of complex IV (cytochrome c oxidase) and the expression of essential proteins involved in the electron transport chain are reduced, leading to lower oxidative phosphorylation and mitochondrial respiration in the preeclamptic placenta. Interventional studies in patients with preeclampsia using the coenzyme Q₁₀, a key molecule in the electron transport chain, suggest that agents that increase the antioxidative capacity of the placenta may be protective against preeclampsia development. In this review, the mitochondrial dysfunction in both eoPE and loPE is summarized. Therapeutic approaches are discussed in the context of contributing to the understanding of mitochondrial dysfunction in eoPE and loPE.

Older adults with obesity have higher risks of some micronutrient inadequacies and lower overall dietary quality compared to peers with a healthy weight, National Health and Nutrition Examination Surveys (NHANES), 2011-2014

OBJECTIVE

To evaluate total usual intakes and biomarkers of micronutrients, overall dietary quality and related health characteristics of US older adults who were overweight or obese compared with a healthy weight.

DESIGN

Cross-sectional study.

SETTING

Two 24-h dietary recalls, nutritional biomarkers and objective and subjective health characteristic data were analysed from the National Health and Nutrition Examination Survey 2011-2014. We used the National Cancer Institute method to estimate distributions of total usual intakes from foods and dietary supplements for eleven micronutrients of potential concern and the Healthy Eating Index (HEI)-2015 score.

PARTICIPANTS

Older adults aged ≥60 years (n 2969) were categorised by sex and body weight status, using standard BMI categories. Underweight individuals (n 47) were excluded due to small sample size.

RESULTS

A greater percentage of obese older adults compared with their healthy-weight counterparts was at risk of inadequate Mg (both sexes), Ca, vitamin B6 and vitamin D (women only) intakes. The proportion of those with serum 25-hydroxyvitamin D < 40 nmol/l was higher in obese (12 %) than in healthy-weight older women (6 %). Mean overall HEI-2015 scores were 8·6 (men) and 7·1 (women) points lower in obese than in healthy-weight older adults. In addition, compared with healthy-weight counterparts, obese older adults were more likely to self-report fair/poor health, use ≥ 5 medications and have limitations in activities of daily living and cardio-metabolic risk factors; and obese older women were more likely to be food-insecure and have depression.

CONCLUSIONS

Our findings suggest that obesity may coexist with micronutrient inadequacy in older adults, especially among women.

Single-step Replacement of an Unreactive C-H Bond by a C-S Bond Using Polysulfide as the Direct Sulfur Source in Anaerobic Ergothioneine Biosynthesis

Ergothioneine, a natural longevity vitamin and antioxidant, is a thiol-histidine derivative. Recently, two types of biosynthetic pathways were reported. In the aerobic ergothioneine biosynthesis, a non-heme iron enzyme incorporates a sulfoxide to an sp² C-H bond in trimethyl-histidine (hercynine) through oxidation reactions. In contrast, in the anaerobic ergothioneine biosynthetic pathway in a green sulfur bacterium, Chlorobium limicola, a rhodanese domain containing protein (EanB) directly replaces this unreactive hercynine C-H bond with a C-S bond. Herein, we demonstrate that polysulfide (HSS_nSR) is the direct sulfur-source in EanB-catalysis. After identifying EanB's substrates, X-ray crystallography of several intermediate states along with mass spectrometry results provide additional mechanistic details for this reaction. Further, quantum mechanics/molecular mechanics (QM/MM) calculations reveal that protonation of N_π of hercynine by Tyr353 with the assistance of Thr414 is a key activation step for the hercynine sp² C-H bond in this trans-sulfuration reaction.

The catalytic mechanism of sulfoxide synthases

Sulfoxide synthases are non-heme iron enzymes that catalyze oxidative carbonsulfur bond formation in the biosynthesis of thiohistidines such as ergothioneine and ovothiol. The catalytic mechanism of these enzymes has been studied by protein crystallography, steady-state kinetics, non-natural amino acid incorporation and computational modeling. This review discusses the current status of this research and also highlights similarities between the CS bond forming activity of sulfoxide synthases with that of synthetic coordination compounds.

Convergent Evolution of Fungal Cysteine Dioxygenases

Cupin-type cysteine dioxygenases (CDOs) are non-heme iron enzymes that occur in animals, plants, bacteria and in filamentous fungi. In this report, we show that agaricomycetes contain an entirely unrelated type of CDO that emerged by convergent evolution from enzymes involved in the biosynthesis of ergothioneine. The activity of this CDO type is dependent on the ergothioneine precursor N-α-trimethylhistidine. The metabolic link between ergothioneine production and cysteine oxidation suggests that the two processes might be part of the same chemical response in fungi, for example against oxidative stress.

Could Ergothioneine Aid in the Treatment of Coronavirus Patients?

Infection with SARS-CoV-2 causes the coronavirus infectious disease 2019 (COVID-19), a pandemic that has, at present, infected more than 11 million people globally. Some COVID-19 patients develop a severe and critical illness, spurred on by excessive inflammation that can lead to respiratory or multiorgan failure. Numerous studies have established the unique array of cytoprotective properties of the dietary amino acid ergothioneine. Based on studies in a range of in vitro and in vivo models, ergothioneine has exhibited the ability to modulate inflammation, scavenge free radicals, protect against acute respiratory distress syndrome, prevent endothelial dysfunction, protect against ischemia and reperfusion injury, protect against neuronal damage, counteract iron dysregulation, hinder lung and liver fibrosis, and mitigate damage to the lungs, kidneys, liver, gastrointestinal tract, and testis, amongst many others. When compiled, this evidence suggests that ergothioneine has a potential application in the treatment of the underlying pathology of COVID-19. We propose that ergothioneine could be used as a therapeutic to reduce the severity and mortality of COVID-19, especially in the elderly and those with underlying health conditions. This review presents evidence to support that proposal.

Long-Term Intake of Dietary Carotenoids Is Positively Associated with Late-Life Subjective Cognitive Function in a Prospective Study in US Women

BACKGROUND

A protective association of dietary carotenoids with cognitive function has been suggested, but most studies have been relatively small with limited periods of follow-up.

OBJECTIVES

We examined prospectively long-term intakes of carotenoids in relation to subjective cognitive function (SCF), a self-reported, validated indicator of cognitive dysfunction.

METHODS

Among 49,493 female registered nurses with a mean age of 48 y in 1984, we used multinomial logistic regression to estimate the ORs and 95% CIs relating intakes of carotenoids to self-reported SCF in 2012 and 2014. Mean intakes of carotenoids were calculated from 7 repeated FFQs collected in 1984, 1986, and every 4 y afterwards until 2006. Self-reported SCF was assessed by a 7-item questionnaire on changes in memory and cognition; validity was supported by strong associations with Apolipoprotein E (APOE) ε4 genotype and concurrent cognitive function and cognitive decline measured by telephone-based neuropsychological tests. The mean values of scores assessed in 2012 and 2014 were categorized as "good" (0 points, 40.8%), "moderate" (0.5-2.5 points, 46.9%), and "poor" (3-7 points, 12.3%).

RESULTS

Higher intake of total carotenoids was associated with substantially lower odds of moderate or poor cognitive function after controlling for other dietary and nondietary risk factors and total energy intake. Comparing the top with the bottom quintile of total carotenoids, the multivariable ORs were 0.86 (95% CI: 0.80, 0.93; P-trend < 0.001) for moderate SCF and 0.67 (95% CI: 0.60, 0.75; P-trend < 0.001) for poor SCF. This lower OR was also seen for carotenoids consumed 28 y before SCF assessment. Similar associations were found for total β-carotene, dietary β-carotene, α-carotene, lycopene, lutein + zeaxanthin, and β-cryptoxanthin. The significant associations for β-cryptoxanthin, lycopene, and lutein + zeaxanthin persisted after mutual adjustment for each other.

CONCLUSIONS

Our findings support a long-term beneficial role of carotenoid consumption on cognitive function in women.

Obesity ‑ a risk factor for increased COVID‑19 prevalence, severity and lethality (Review)

Coronaviruses (CoVs), enveloped positive-sense RNA viruses, are a group of viruses that cause infections in the human respiratory tract, which can be characterized clinically from mild to fatal. The severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) is the virus responsible. The global spread of COVID‑19 can be described as the worst pandemic in humanity in the last century. To date, COVID‑19 has infected more than 3,000,000 people worldwide and killed more than 200,000 people. All age groups can be infected from the virus, but more serious symptoms that can possibly result in death are observed in older people and those with underlying medical conditions such as cardiovascular and pulmonary disease. Novel data report more severe symptoms and even a negative prognosis for the obese patients. A growing body of evidence connects obesity with COVID‑19 and a number of mechanisms from immune system activity attenuation to chronic inflammation are implicated. Lipid peroxidation creates reactive lipid aldehydes which in a patient with metabolic disorder and COVID‑19 will affect its prognosis. Finally, pregnancy‑associated obesity needs to be studied further in connection to COVID‑19 as this infection could pose high risk both to pregnant women and the fetus.

Metformin Reduces Aging-Related Leaky Gut and Improves Cognitive Function by Beneficially Modulating Gut Microbiome/Goblet Cell/Mucin Axis

Aging-related illnesses are increasing and effective strategies to prevent and/or treat them are lacking. This is because of a poor understanding of therapeutic targets. Low-grade inflammation is often higher in older adults and remains a key risk factor of aging-related morbidities and mortalities. Emerging evidence indicates that abnormal (dysbiotic) gut microbiome and dysfunctional gut permeability (leaky gut) are linked with increased inflammation in older adults. However, currently available drugs do not treat aging-related microbiome dysbiosis and leaky gut, and little is known about the cellular and molecular processes that can be targeted to reduce leaky gut in older adults. Here, we demonstrated that metformin, a safe Food and Drug Administration-approved antidiabetic drug, decreased leaky gut and inflammation in high-fat diet-fed older obese mice, by beneficially modulating the gut microbiota. In addition, metformin increased goblet cell mass and mucin production in the obese older gut, thereby decreasing leaky gut and inflammation. Mechanistically, metformin increased the goblet cell differentiation markers by suppressing Wnt signaling. Our results suggest that metformin can be used as a regimen to prevent and treat aging-related leaky gut and inflammation, especially in obese individuals and people with western-style high-fat dietary lifestyle, by beneficially modulating gut microbiome/goblet cell/mucin biology.

Role of antioxidants and a nutrient rich diet in Alzheimer's disease

The joint attack on the body by metabolic acidosis and oxidative stress suggests that treatment in degenerative diseases, including Alzheimer's disease (AD), may require a normalizing of extracellular and intracellular pH with simultaneous supplementation of an antioxidant combination cocktail at a sufficiently high dose. Evidence is also accumulating that combinations of antioxidants may be more effective, taking advantage of synergistic effects of appropriate antioxidants as well as a nutrient-rich diet to prevent and reverse AD. This review focuses on nutritional, nutraceutical and antioxidant treatments of AD, although they can also be used in other chronic degenerative and neurodegenerative diseases.

The Biology of Lactoferrin, an Iron-Binding Protein That Can Help Defend Against Viruses and Bacteria

Lactoferrin is a nutrient classically found in mammalian milk. It binds iron and is transferred via a variety of receptors into and between cells, serum, bile, and cerebrospinal fluid. It has important immunological properties, and is both antibacterial and antiviral. In particular, there is evidence that it can bind to at least some of the receptors used by coronaviruses and thereby block their entry. Of importance are Heparan Sulfate Proteoglycans (HSPGs) and the host receptor angiotensin-converting enzyme 2 (ACE2), as based on other activities lactoferrin might prevent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from attaching to the host cells. Lactoferrin (and more specifically enteric-coated LF because of increased bioavailability) may consequently be of preventive and therapeutic value during the present COVID-19 pandemic.

Diabetes mellitus type 2 drives metabolic reprogramming to promote pancreatic cancer growth

Background

Diabetes mellitus type 2 (DM2) is a modifiable risk factor associated with pancreatic carcinogenesis and tumor progression on the basis of epidemiology studies, but the biological mechanisms are not completely understood. The purpose of this study is to demonstrate direct evidence for the mechanisms mediating these epidemiologic phenomena. Our hypothesis is that DM2 accelerates pancreatic cancer growth and that metformin treatment has a beneficial impact.

Methods

To determine the effect of glucose and insulin in pancreatic cancer proliferation, we used conditioned media to mimic DM2 conditions. Also, we studied the effect of anti-diabetic drugs, particularly metformin and rosiglitazone on pancreatic cancer growth. We established orthotopic/syngeneic (Lepr^db/db) mouse cancer models to evaluate the effect of diabetes on pancreatic tumor growth and aggressiveness.

Results

Our results showed that diabetes promotes pancreatic tumor growth. Furthermore, enhanced tumor growth and aggressiveness (e.g. epithelial–mesenchymal transition) can be explained by functional transcriptomic and metabolomic changes in the mice with diabetes, namely via activation of the AKT/mTOR pathway. Metformin treatment suppressed the diabetes-induced AKT/mTOR pathway activation and tumor growth. The metabolic profile determined by mass spectrum showed important changes of metabolites in the pancreatic cancer derived from diabetic mice treated with metformin.

Conclusions

Diabetes mellitus type 2 has critical effects that promote pancreatic cancer progression via transcriptomic and metabolomic changes. Our animal models provide strong evidence for the causal relationship between diabetes and accelerated pancreatic cancers. This study sheds a new insight into the effects of metformin and its potential as part of therapeutic interventions for pancreatic cancer in diabetic patients.

Dehydroascorbic acid, the oxidized form of vitamin C, improves renal histology and function in old mice

Oxidative stress and inflammation are crucial factors that increase with age. In the progression of multiple age-related diseases, antioxidants and bioactive compounds have been recognized as useful antiaging agents. Oxidized or reduced vitamin C exerts different actions on tissues and has different metabolism and uptake. In this study, we analyzed the antiaging effect of vitamin C, both oxidized and reduced forms, in renal aging using laser microdissection, quantitative reverse-transcription polymerase chain reaction, and immunohistochemical analyses. In the kidneys of old SAM mice (10 months of age), a model of accelerated senescence, vitamin C, especially in the oxidized form (dehydroascorbic acid [DHA]) improves renal histology and function. Serum creatinine levels and microalbuminuria also decrease after treatment with a decline in azotemia. In addition, sodium-vitamin C cotransporter isoform 1 levels, which were increased during aging, are normalized. In contrast, the pattern of glucose transporter 1 expression is not affected by aging or vitamin C treatment. We conclude that oxidized and reduced vitamin C are potent antiaging therapies and that DHA reverses the kidney damage observed in senescence-accelerated prone mouse 8 to a greater degree.

Vitamin E and Mortality in Male Smokers of the ATBC Study: Implications for Nutritional Recommendations

The Dietary Reference Intakes (DRI)-monograph (USA/Canada) states that the estimated average requirement (EAR) of vitamin E for men and women of any age is 12 mg/day. The EAR value is based on in vitro hemolysis in young males; a surrogate endpoint without any direct validity. The EAR is then extrapolated to females and older males. The validity of the EAR level is therefore questionable. Total mortality is an outcome of direct clinical relevance. Investigating the effect of long-term dietary vitamin E intake level on mortality in a randomized trial is, however, not feasible. Nevertheless, the effect of dietary vitamin E intake can be investigated indirectly from the effects of a fixed-level vitamin E supplement administered to participants on variable levels of dietary vitamin E intake. If vitamin E intake below the EAR is harmful, then vitamin E supplement should be beneficial to those people who have dietary vitamin E intake level below the EAR. The purpose of this study was to analyze the association between dietary vitamin E intake and the effect of 25 mg/day of vitamin E supplement on total mortality in Finnish male smokers aged 50-69 years in the Alpha-Tocopherol-Beta-Carotene (ATBC) Study. The effect of vitamin E supplement was estimated by Cox regression. Among participants who had dietary vitamin C intake of 90 mg/day and above, vitamin E supplement increased mortality by 19% (p = 0.006) in those aged 50-62 years, but decreased mortality by 41% (p = 0.0003) in those aged 66-69 years. No association between vitamin E supplement effect and dietary vitamin E intake was found in these two groups, nor in participants who had dietary vitamin C intake less than 90 mg/day. There is no evidence in any of the analyzed subgroups that there is a difference in the effect of the 25 mg/day vitamin E supplement on males on dietary vitamin E intakes below vs. above the EAR of 12 mg/day. This analysis of the ATBC Study found no support for the 'estimated average requirement' level of 12 mg/day of vitamin E for older males. Trial registration: ClinicalTrials.gov, identifier: NCT00342992.

Reactive oxygen species (ROS) as pleiotropic physiological signalling agents

'Reactive oxygen species' (ROS) is an umbrella term for an array of derivatives of molecular oxygen that occur as a normal attribute of aerobic life. Elevated formation of the different ROS leads to molecular damage, denoted as 'oxidative distress'. Here we focus on ROS at physiological levels and their central role in redox signalling via different post-translational modifications, denoted as 'oxidative eustress'. Two species, hydrogen peroxide (H₂O₂) and the superoxide anion radical (O₂^·-), are key redox signalling agents generated under the control of growth factors and cytokines by more than 40 enzymes, prominently including NADPH oxidases and the mitochondrial electron transport chain. At the low physiological levels in the nanomolar range, H₂O₂ is the major agent signalling through specific protein targets, which engage in metabolic regulation and stress responses to support cellular adaptation to a changing environment and stress. In addition, several other reactive species are involved in redox signalling, for instance nitric oxide, hydrogen sulfide and oxidized lipids. Recent methodological advances permit the assessment of molecular interactions of specific ROS molecules with specific targets in redox signalling pathways. Accordingly, major advances have occurred in understanding the role of these oxidants in physiology and disease, including the nervous, cardiovascular and immune systems, skeletal muscle and metabolic regulation as well as ageing and cancer. In the past, unspecific elimination of ROS by use of low molecular mass antioxidant compounds was not successful in counteracting disease initiation and progression in clinical trials. However, controlling specific ROS-mediated signalling pathways by selective targeting offers a perspective for a future of more refined redox medicine. This includes enzymatic defence systems such as those controlled by the stress-response transcription factors NRF2 and nuclear factor-κB, the role of trace elements such as selenium, the use of redox drugs and the modulation of environmental factors collectively known as the exposome (for example, nutrition, lifestyle and irradiation).

Astaxanthin Prevents Mitochondrial Impairment Induced by Isoproterenol in Isolated Rat Heart Mitochondria

Mitochondria are considered to be a power station of the cell. It is known that they play a major role in both normal and pathological heart function. Alterations in mitochondrial bioenergetics are one of the main causes of the origin and progression of heart failure since they have an inhibitory effect on the activity of respiratory complexes in the inner mitochondrial membrane. Astaxanthin (AST) is a xanthophyll carotenoid of mainly marine origin. It has both lipophilic and hydrophilic properties and may prevent mitochondrial dysfunction by permeating the cell membrane and co-localizing within mitochondria. The carotenoid suppresses oxidative stress-induced mitochondrial dysfunction and the development of diseases. In the present study, it was found that the preliminary oral administration of AST upregulated the activity of respiratory chain complexes and ATP synthase and the level of their main subunits, thereby improving the respiration of rat heart mitochondria (RHM) in the heart injured by isoproterenol (ISO). AST decreased the level of cyclophilin D (CyP-D) and increased the level of adenine nucleotide translocase (ANT) in this condition. It was concluded that AST could be considered as a potential mitochondrial-targeted agent in the therapy of pathological conditions associated with oxidative damage and mitochondrial dysfunction. AST, as a dietary supplement, has a potential in the prevention of cardiovascular diseases.

tRNA Queuosine Modification Enzyme Modulates the Growth and Microbiome Recruitment to Breast Tumors

BACKGROUND

Transfer RNA (tRNA) queuosine (Q)-modifications occur specifically in 4 cellular tRNAs at the wobble anticodon position. tRNA Q-modification in human cells depends on the gut microbiome because the microbiome product queuine is required for its installation by the enzyme Q tRNA ribosyltransferase catalytic subunit 1 (QTRT1) encoded in the human genome. Queuine is a micronutrient from diet and microbiome. Although tRNA Q-modification has been studied for a long time regarding its properties in decoding and tRNA fragment generation, how QTRT1 affects tumorigenesis and the microbiome is still poorly understood.

RESULTS

We generated single clones of QTRT1-knockout breast cancer MCF7 cells using Double Nickase Plasmid. We also established a QTRT1-knockdown breast MDA-MB-231 cell line. The impacts of QTRT1 deletion or reduction on cell proliferation and migration in vitro were evaluated using cell culture, while the regulations on tumor growth in vivo were evaluated using a xenograft BALB/c nude mouse model. We found that QTRT1 deficiency in human breast cancer cells could change the functions of regulation genes, which are critical in cell proliferation, tight junction formation, and migration in human breast cancer cells in vitro and a breast tumor mouse model in vivo. We identified that several core bacteria, such as Lachnospiraceae, Lactobacillus, and Alistipes, were markedly changed in mice post injection with breast cancer cells. The relative abundance of bacteria in tumors induced from wildtype cells was significantly higher than those of QTRT1 deficiency cells.

CONCLUSIONS

Our results demonstrate that the QTRT1 gene and tRNA Q-modification altered cell proliferation, junctions, and microbiome in tumors and the intestine, thus playing a critical role in breast cancer development.

Multivariate Analysis of Influence of Vitamin Intake on Vascular Function Parameters by Sex in the General Spanish Population: EVA Study

The influence of vitamin intake on vascular function parameters in the Spanish general population has not been studied. The main objective of this study is to analyze the influence of vitamin intake on vascular function and as a secondary objective the adequacy of vitamin intake in a sample of the Spanish population without previous cardiovascular disease and analyze the differences according to sex. Methods: We included 501 individuals obtained by simple random sampling with replacement (reference population 43,946). The average age was 55.90 ± 14.24 years, 49.70% men. Participants recorded the intake of vitamins using the EVIDENT app, previously validated, during a period of 3 days. Vascular function was assessed by measuring carotid-femoral pulse wave velocity (cfPWV) with the SphygmoCor device, cardio-ankle vascular index (CAVI) with the VaSera device and brachial-ankle pulse wave velocity (baPWV) by using a validated equation. Results: The vitamins with the least adequate intake was vitamin D, less than 5%, and vitamin B9, less than 35%. Vitamins with an adequate intake percentage, close to 100%, were B12 and B6. The multiple regression analysis showed a negative association between cfPWV and vitamin B2 in both sexes, and a positive one with retinol in men and B3 in women. baPWV was negatively associated with vitamins B1 and B12 in women and B9 in men, while being positively linked with B6 in men. CAVI presented a negative association with vitamin D in women. The results were similar in the canonical correspondence analysis. In conclusion, the results of this study suggest that the influence of vitamins on vascular function is not homogeneous and varies according to the parameter analyzed. Thus, in men, vitamins B2 and retinol were associated with cfPWV and vitamins B6 and B9 with baPWV. In women, vitamins B2 and B3 were related cfPWV, vitamins B1 and B12 with cfPWV and vitamin D with CAVI.

Taurine and cardiac disease: state of the art and perspectives

Taurine is a nonessential amino acid that has received much attention. Two organs, the heart and the brain, are known to produce their own taurine, but in very limited quantities. It is for this reason that supplementation with this amino acid is necessary. Today, taurine is present in almost all energy drinks. A very vast literature reported beneficial effects of taurine in hepatic dysfunction, gastrointestinal injury, kidney diseases, diabetes, and cardiovascular diseases. Most of its effects were attributed to its modulation of Ca2+homeostasis as well as to its antioxidant properties. In this review, we will focus on the current status of taurine modulation of the cardiovascular system and discuss future avenues for its use as a supplement therapy in a specific cardiovascular disease, namely hypertrophy, and heart failure.

L-(+)-Ergothioneine Significantly Improves the Clinical Characteristics of Preeclampsia in the Reduced Uterine Perfusion Pressure Rat Model

Preeclampsia is a multifactorial hypertensive disorder of pregnancy founded on abnormal placentation, and the resultant placental ischemic microenvironment is thought to play a crucial role in its pathophysiology. Placental ischemia because of fluctuations in the delivery of oxygen results in oxidative stress, and recent evidence suggests that mitochondrial dysfunction may be a prime mediator. However, large clinical trials of therapeutic antioxidants such as vitamins C and E for the treatment of preeclampsia have been disappointing. L-(+)-ergothioneine (ERG)-an unusual amino acid betaine derived from histidine-has important cytoprotective and antioxidant properties under conditions of high oxidative stress. In this study, we investigated the potential therapeutic effects of administration of ERG in the reduced uterine perfusion pressure (RUPP) rat model of preeclampsia. ERG (25 mg/kg per day) was administered to rats on gestational day 11. On gestational day 14, RUPP surgery was performed, and on gestational day 19, blood pressure (mean arterial pressure) and fetal growth were measured. Production of mitochondria-specific H₂O₂ was analyzed in vivo in kidney samples. ERG ameliorated the hypertension (129±3 versus 115±4 mm Hg; P=0.01; n=8) and significantly increased pup weight in RUPP rats. ERG also significantly decreased circulating levels of antiangiogenic sFlt-1 (soluble fms-like tyrosine kinase-1) in RUPP rats (1367±245 pg/mL; P=0.04). Mitochondria-specific H₂O₂ (0.022±0.003 versus 0.029±0.001; MitoP/B ratio, n=3; P=0.05) was also significantly decreased in kidney tissue in RUPP rats treated with ERG. These data support the potential use of ERG for the treatment of preeclampsia.

Riboflavin and pyrroloquinoline quinone generate carbon monoxide in the presence of tissue microsomes or recombinant human cytochrome P-450 oxidoreductase: implications for possible roles in gasotransmission

Carbon monoxide (CO), an endogenously produced gasotransmitter, regulates inflammation and vascular tone, suggesting that delivery of CO may be therapeutically useful for pathologies like preeclampsia where CO insufficiency is implicated. Our strategy is to identify chemicals that increase the activity of endogenous CO-producing enzymes, including cytochrome P-450 oxidoreductase (CPR). Realizing that both riboflavin and pyrroloquinoline quinone (PQQ) are relatively nontoxic, even at high doses, and that they share chemical properties with toxic CO activators that we previously identified, our goal was to determine whether riboflavin or PQQ could stimulate CO production. Riboflavin and PQQ were incubated in sealed vessels with rat and human tissue extracts and CO generation was measured with headspace-gas chromatography. Riboflavin and PQQ increased CO production ∼60% in rat spleen microsomes. In rat brain microsomes, riboflavin and PQQ increased respective CO production approximately fourfold and twofold compared to baseline. CO production by human placenta microsomes increased fourfold with riboflavin and fivefold with PQQ. In the presence of recombinant human CPR, CO production was threefold greater with PQQ than with riboflavin. These observations demonstrate for the first time that riboflavin and PQQ facilitate tissue-specific CO production with significant contributions from CPR. We propose a novel biochemical role for these nutrients in gastransmission.

Engineering the Yeast Saccharomyces cerevisiae for the Production of L-(+)-Ergothioneine

L-(+)-Ergothioneine (ERG) is an unusual, naturally occurring antioxidant nutraceutical that has been shown to help reduce cellular oxidative damage. Humans do not biosynthesise ERG, but acquire it from their diet; it exploits a specific transporter (SLC22A4) for its uptake. ERG is considered to be a nutraceutical and possible vitamin that is involved in the maintenance of health, and seems to be at too low a concentration in several diseases in vivo. Ergothioneine is thus a potentially useful dietary supplement. Present methods of commercial production rely on extraction from natural sources or on chemical synthesis. Here we describe the engineering of the baker's yeast Saccharomyces cerevisiae to produce ergothioneine by fermentation in defined media. After integrating combinations of ERG biosynthetic pathways from different organisms, we screened yeast strains for their production of ERG. The highest-producing strain was also engineered with known ergothioneine transporters. The effect of amino acid supplementation of the medium was investigated and the nitrogen metabolism of S. cerevisiae was altered by knock-out of TOR1 or YIH1. We also optimized the media composition using fractional factorial methods. Our optimal strategy led to a titer of 598 ± 18 mg/L ergothioneine in fed-batch culture in 1 L bioreactors. Because S. cerevisiae is a GRAS ("generally recognized as safe") organism that is widely used for nutraceutical production, this work provides a promising process for the biosynthetic production of ERG.

Discovery of novel bacterial queuine salvage enzymes and pathways in human pathogens

Queuosine (Q) is a complex tRNA modification widespread in eukaryotes and bacteria that contributes to the efficiency and accuracy of protein synthesis. Eukaryotes are not capable of Q synthesis and rely on salvage of the queuine base (q) as a Q precursor. While many bacteria are capable of Q de novo synthesis, salvage of the prokaryotic Q precursors preQ0 and preQ1 also occurs. With the exception of Escherichia coli YhhQ, shown to transport preQ0 and preQ1, the enzymes and transporters involved in Q salvage and recycling have not been well described. We discovered and characterized 2 Q salvage pathways present in many pathogenic and commensal bacteria. The first, found in the intracellular pathogen Chlamydia trachomatis, uses YhhQ and tRNA guanine transglycosylase (TGT) homologs that have changed substrate specificities to directly salvage q, mimicking the eukaryotic pathway. The second, found in bacteria from the gut flora such as Clostridioides difficile, salvages preQ1 from q through an unprecedented reaction catalyzed by a newly defined subgroup of the radical-SAM enzyme family. The source of q can be external through transport by members of the energy-coupling factor (ECF) family or internal through hydrolysis of Q by a dedicated nucleosidase. This work reinforces the concept that hosts and members of their associated microbiota compete for the salvage of Q precursors micronutrients.

Contaminants: a dark side of food supplements?

Food supplements (FS) are often consumed as one of the strategies to fight ageing-associated pathologies, especially in the case of oxidative stress-related diseases. Despite the popularity of FS, some concerns about their quality and safety have been raised, especially regarding the presence of contaminants. This paper reviews and discusses the occurrence of contaminants in marketed samples of FS in the last two decades, considering both scientific literature and notifications registered on RASFF portal. The most relevant classes of contaminants were included namely metals, toxins, pesticides, dioxins and PCBs, as well as pharmacologically active ingredients. Variable amounts of contaminants were reported in a significant number of commercially available FS. Although the presence of contaminants does not necessarily mean that their levels exceed the regulatory limits or that the FS intake constitutes a risk to human health, it alerts for the need to further monitor FS safety. The evaluation of the risk associated to the consumption of FS, especially in the elderly population, is particularly challenging due to the frequent exposure to multiple toxicants and to different exposure sources, as well as due to possible pre-existing diseases and respective therapeutics. Therefore, improved quality control procedures and monitoring programs should be pursued in order to avoid undesirable products and assure the safety of FS.

Fat Soluble Vitamins in Institutionalized Elderly and the Effect of Exercise, Nutrition and Cognitive Training on Their Status-The Vienna Active Aging Study (VAAS): A Randomized Controlled Trial

BACKGROUND

Institutionalized elderly are at higher risk for micronutrient deficiency. In particular, fat soluble micronutrients, which additionally have antioxidative function, are of interest. The purpose of this secondary investigation of the Vienna Active Ageing Study was to assess and evaluate the plasma status of retinol, alpha- and gamma-tocopherol, alpha- and beta-carotene, lutein, zeaxanthin, beta-cryptoxanthin, and lycopene, as well as vitamin D (25(OH)D) in a cohort of institutionalized elderly. We further determined the effect of six months strength training with or without supplementing (antioxidant) vitamins and protein on the plasma status of these ten micronutrients.

METHODS

Three groups (n = 117, age = 83.1 ± 6.1 years)-resistance training (RT), RT combined with protein and vitamin supplementation (RTS), or cognitive training (CT)-performed two guided training sessions per week for six months. Micronutrients were measured with High Performance Liquid Chromatography (HPLC) at baseline and after 6 months of intervention. Physical fitness was assessed by the 6-min-walking, the 30-s chair rise, isokinetic dynamometry, and the handgrip strength tests.

RESULTS

At baseline, the plasma status of retinol was satisfactory, for alpha-tocopherol, beta-carotene, and 25(OH)D, the percentage of individuals with an insufficient status was 33%, 73% and 61%/81% (when using 50 nmol/L or 75 nmol/L as threshold levels for 25(OH)D), respectively. Plasma analyses were supported by intake data. Six months of elastic band resistance training with or without protein-vitamin supplementation had no biological impact on the status of fat soluble micronutrients. Even for vitamin D, which was part of the nutritional supplement (additional 20 µg/d), the plasma status did not increase significantly, however it contributed to a lower percentage of elderly below the threshold levels of 50/75 nmol/L (49%/74%).

CONCLUSIONS

The findings of the study lead to the strong recommendation for regular physical activity and increased consumption of plant-based foods in institutionalized elderly. When supported by blood analysis, supplementing micronutrients in a moderate range should also be considered.

β-carotene in Obesity Research: Technical Considerations and Current Status of the Field

Over the past decades, obesity has become a rising health problem as the accessibility to high calorie, low nutritional value food has increased. Research shows that some bioactive components in fruits and vegetables, such as carotenoids, could contribute to the prevention and treatment of obesity. Some of these carotenoids are responsible for vitamin A production, a hormone-like vitamin with pleiotropic effects in mammals. Among these effects, vitamin A is a potent regulator of adipose tissue development, and is therefore important for obesity. This review focuses on the role of the provitamin A carotenoid β-carotene in human health, emphasizing the mechanisms by which this compound and its derivatives regulate adipocyte biology. It also discusses the physiological relevance of carotenoid accumulation, the implication of the carotenoid-cleaving enzymes, and the technical difficulties and considerations researchers must take when working with these bioactive molecules. Thanks to the broad spectrum of functions carotenoids have in modern nutrition and health, it is necessary to understand their benefits regarding to metabolic diseases such as obesity in order to evaluate their applicability to the medical and pharmaceutical fields.

Beneficial Role of Phytochemicals on Oxidative Stress and Age-Related Diseases

Aging is related to a number of functional and morphological changes leading to progressive decline of the biological functions of an organism. Reactive Oxygen Species (ROS), released by several endogenous and exogenous processes, may cause important oxidative damage to DNA, proteins, and lipids, leading to important cellular dysfunctions. The imbalance between ROS production and antioxidant defenses brings to oxidative stress conditions and, related to accumulation of ROS, aging-associated diseases. The purpose of this review is to provide an overview of the most relevant data reported in literature on the natural compounds, mainly phytochemicals, with antioxidant activity and their potential protective effects on age-related diseases such as metabolic syndrome, diabetes, cardiovascular disease, cancer, neurodegenerative disease, and chronic inflammation, and possibly lower side effects, when compared to other drugs.

The redox biology of redox-inert zinc ions

Zinc(II) ions are redox-inert in biology. Yet, their interaction with sulfur of cysteine in cellular proteins can confer ligand-centered redox activity on zinc coordination sites, control protein functions, and generate signalling zinc ions as potent effectors of many cellular processes. The specificity and relative high affinity of binding sites for zinc allow regulation in redox biology, free radical biology, and the biology of reactive species. Understanding the role of zinc in these areas of biology requires an understanding of how cellular Zn²⁺ is homeostatically controlled and can serve as a regulatory ion in addition to Ca²⁺, albeit at much lower concentrations. A rather complex system of dozens of transporters and metallothioneins buffer the relatively high (hundreds of micromolar) total cellular zinc concentrations in such a way that the available zinc ion concentrations are only picomolar but can fluctuate in signalling. The proteins targeted by Zn²⁺ transients include enzymes controlling phosphorylation and redox signalling pathways. Networks of regulatory functions of zinc integrate gene expression and metabolic and signalling pathways at several hierarchical levels. They affect enzymatic catalysis, protein structure and protein-protein/biomolecular interactions and add to the already impressive number of catalytic and structural functions of zinc in an estimated three thousand human zinc proteins. The effects of zinc on redox biology have adduced evidence that zinc is an antioxidant. Without further qualifications, this notion is misleading and prevents a true understanding of the roles of zinc in biology. Its antioxidant-like effects are indirect and expressed only in certain conditions because a lack of zinc and too much zinc have pro-oxidant effects. Teasing apart these functions based on quantitative considerations of homeostatic control of cellular zinc is critical because opposite consequences are observed depending on the concentrations of zinc: pro- or anti-apoptotic, pro- or anti-inflammatory and cytoprotective or cytotoxic. The article provides a biochemical basis for the links between redox and zinc biology and discusses why zinc has pleiotropic functions. Perturbation of zinc metabolism is a consequence of conditions of redox stress. Zinc deficiency, either nutritional or conditioned, and cellular zinc overload cause oxidative stress. Thus, there is causation in the relationship between zinc metabolism and the many diseases associated with oxidative stress.

Specificity of the ergothioneine transporter natively expressed in HeLa cells

Ergothioneine is a biologically important compound that has been shown to be transported by the organic cation transporter novel type 1 (OCTN1). Following this discovery, a variety of alternate functions for OCTN1 have been suggested including an integral function in the extra-neuronal cholinergic system. The present study reaffirms the primacy of ergothioneine over these alternate substrates using natively expressed OCTN1 in HeLa cells. Besides the general transport inhibitors, quinidine, verapamil and pyrilamine no other putative substrate inhibited ergothioneine transport significantly, with only a slight inhibition demonstrated by carnitine. Even compounds structurally similar to ergothioneine failed to inhibit ergothioneine uptake, suggesting high selectivity of OCTN1. Ergothioneine was found to be avidly accumulated even at low concentrations (300 nM) by HeLa cells.

Cardiovascular mortality attributable to dietary risk factors in 51 countries in the WHO European Region from 1990 to 2016: a systematic analysis of the Global Burden of Disease Study

This study was performed to highlight the relationship between single dietary risk factors and cardiovascular diseases (CVDs) in the WHO European Region. We used the comparative risk assessment framework of the Global Burden of Disease Study to estimate CVD mortality attributable to diet; comprising eleven forms of CVDs, twelve food and nutrient groups and 27 risk-outcome pairs in four GBD regions including 51 countries by age and sex between 1990 and 2016. In 2016, dietary risks were associated with 2.1 million cardiovascular deaths (95% uncertainty interval (UI), 1.7-2.5 million) in the WHO European Region, accounting for 22.4% of all deaths and 49.2% of CVD deaths. In terms of single dietary risks, a diet low in whole grains accounted for approximately 429,000 deaths, followed by a diet low in nuts and seeds (341,000 deaths), a diet low in fruits (262,000 deaths), a diet high in sodium (251,000 deaths), and a diet low in omega-3 fatty acids (227,000 deaths). Thus, with an optimized, i.e. balanced diet, roughly one in every five premature deaths could be prevented. Although age-standardized death rates decreased over the last 26 years, the absolute number of diet-related cardiovascular deaths increased between 2010 and 2016 by 25,600 deaths in Western Europe and by 4300 deaths in Central Asia. In 2016, approximately 601,000 deaths (28.6% of all diet-related CVD deaths) occurred among adults younger than 70 years. Compared to other behavioural risk factors, a balanced diet is a potential key lever to avoid premature deaths.

Aging Biomarkers and Novel Targets for Anti-Aging Interventions

The aging population worldwide is expanding at an increasing rate. By 2050, approximately a quarter of the world population will consist of the elderly. To slow down the aging process, exploration of aging biomarkers and the search for novel antiaging targets have attracted much interest. Nonetheless, because aging research is costly and time-consuming and the aging process is complicated, aging research is considered one of the most difficult biological fields. Here, providing a broader definition of aging biomarkers, we review cutting-edge research on aging biomarkers at the molecular, cellular, and organismal levels, thus shedding light on the relations between aging and telomeres, longevity proteins, a senescence-associated secretory phenotype, the gut microbiota and metabolic patterns. Furthermore, we evaluate the suitability of these aging biomarkers for the development of novel antiaging targets on the basis of the most recent research on this topic. We also discuss the possible implications and some controversies regarding these biomarkers for therapeutic interventions in aging and age-related disease processes. We have attempted to cover all of the latest research on aging biomarkers in our review but there are countless studies on aging biomarkers, and the topic of aging interventions will continue to deepen even further. We hope that our review can serve as a reference for better characterization of aging and as inspiration for the screening of antiaging drugs as well as give some clues to further research into aging biomarkers and antiaging targets.