Metabolic footprint of aging and obesity in red blood cells

Arginine metabolism is a biomarker of red blood cell and human aging

Increasing global life expectancy motivates investigations of molecular mechanisms of aging and age-related diseases. This study examines age-associated changes in red blood cells (RBCs), the most numerous host cell in humans. Four cohorts, including healthy individuals and patients with sickle cell disease, were analyzed to define age-dependent changes in RBC metabolism. Over 15,700 specimens from 13,757 humans were examined, a major expansion over previous studies of RBCs in aging. Multi-omics approaches identified chronological age-related alterations in the arginine pathway with increased arginine utilization in RBCs from older individuals. These changes were consistent across healthy and sickle cell disease cohorts and were influenced by genetic variation, sex, and body mass index. Integrating multi-omics data and metabolite quantitative trait loci (mQTL) in humans and 525 diversity outbred mice functionally linked metabolism of arginine during RBC storage to increased vesiculation-a hallmark of RBC aging-and lower post-transfusion hemoglobin increments. Thus, arginine metabolism is a biomarker of RBC and organismal aging, suggesting potential new targets for addressing sequelae of aging.

Erythrocyte nicotinamide adenine dinucleotide concentration is enhanced by systematic sports participation

BACKGROUND

Nicotinamide adenine dinucleotide (NAD+), nicotinamide adenine dinucleotide phosphate (NADP+), and their reduced forms (NADH and NADPH) are the vital cofactors for most cellular oxidation/reduction reactions and therefore influence most critical pathways in cellular metabolism. This study aimed to predict the trends of age-related changes in erythrocyte NAD+ and NADP+ concentrations in elite athletes compared to untrained controls and to assess whether life-long physical training stimulates favorable adaptations in erythrocyte NAD(P)+ concentrations.

METHODS

Erythrocyte concentrations of NAD+ and NADP+ were measured in 68 elite endurance runners (20-81 years), 58 elite sprinters (21-90 years), and 62 untrained individuals (20-68 years). Linear regression analyses were performed to estimate longitudinal relationships and cross-sectional rates of change between age and erythrocyte NAD+ and NADP+ levels. One-way analysis of variance was used to determine differences between the studied groups.

RESULTS

In all three groups, the erythrocyte NAD+ and NADP+ concentrations significantly decreased with advancing age, suggesting gradual deterioration of NAD-related regulatory functions in older individuals. However, the concentration of erythrocyte NAD(P)+, regardless of age category, was higher in the athletic groups compared to less active controls.

CONCLUSIONS

Our research shows that systematic sports participation, especially of a sprint-oriented nature, can be treated as a natural and effective strategy promoting cellular NAD(P)+ anabolism and thus cells' energy and redox metabolism.

TRIAL REGISTRATION

The study was retrospectively registered in the clinical trials registry on 2021-11-09 (NCT05113914).

Erythrocyte Oxidative Status in People with Obesity: Relation to Tissue Losses, Glucose Levels, and Weight Reduction

BACKGROUND

This study aimed to investigate the impact of reductions in various body mass components on the erythrocyte oxidative status and glycemic state of people with obesity (PWO).

METHODS

A total of 53 PWO followed a six-month individualized low-calorie diet with exercise, during which anthropometric, biochemical, and oxidative parameters were measured. The participants were divided into groups based on weight (W), visceral fat area (VFA), total body water (TBW), and skeletal muscle mass (SMM) losses, as well as normoglycemia (NG) and hyperglycemia (HG).

RESULTS

Weight reduction normalized glycemia and influenced erythrocyte enzyme activity. Regardless of the tissue type lost (VFA, TBW, or SMM), glutathione peroxidase activity decreased in all groups, accompanied by an increase in glutathione reductase activity. Lipofuscin (LPS) and malondialdehyde (MDA) concentrations decreased regardless of the type of tissue lost. The α-/γ-tocopherol ratio increased in those losing >10% body weight, >15% VFA, and >5% TBW. In the NG group, compared to the HG group, there was a decrease in glutathione peroxidase and an increase in glutathione reductase, with these changes being stronger in the HG group. The LPS and MDA concentrations decreased in both groups. Significant correlations were observed between glucose reduction and changes in catalase, retinol, and α-tocopherol, as well as between VFA reduction and changes in vitamin E, L-LPS, and the activities of L-GR and L-GST.

CONCLUSIONS

This analysis highlights the complex interactions between glucose metabolism, oxidative state, and erythrocyte membrane integrity, crucial for understanding diabetes and its management. This study shows the significant metabolic adaptability of erythrocytes in response to systemic changes induced by obesity and hyperglycemia, suggesting potential therapeutic targets to improve metabolic health in obese individuals.

NMR-Based Mitochondria Metabolomic Profiling: A New Approach To Reveal Cancer-Associated Alterations

Studying metabolism may assist in understanding the relationship between normal and dysfunctional mitochondrial activity and various diseases, such as neurodegenerative, cardiovascular, autoimmune, psychiatric, and cancer. Nuclear magnetic resonance-based metabolomics represents a powerful method to characterize the chemical content of complex samples and has been successfully applied to studying a range of conditions. However, an optimized methodology is lacking for analyzing isolated organelles, such as mitochondria. In this study, we report the development of a protocol to metabolically profile mitochondria from healthy, tumoral, and metastatic tissues. Encouragingly, this approach provided quantitative information about up to 45 metabolites in one comprehensive and robust analysis. Our results revealed significant differences between whole-cell and mitochondrial metabolites, which supports a more refined approach to metabolic analysis. We applied our optimized methodology to investigate aggressive and metastatic breast cancer in mouse tissues, discovering that lung mitochondria exhibit an altered metabolic fingerprint. Specific amino acids, organic acids, and lipids showed significant increases in levels when compared with mitochondria from healthy tissues. Our optimized methodology could promote a better understanding of the molecular mechanisms underlying breast cancer aggressiveness and mitochondrial-related diseases and support the optimization of new advanced therapies.

Sports Participation Promotes Beneficial Adaptations in the Erythrocyte Guanylate Nucleotide Pool in Male Athletes Aged 20-90 Years

Introduction

The guanine nucleotide pool (GTP, guanosine-5'-triphosphate; GDP, guanosine-5'-diphosphate, and GMP, guanosine-5'-monophosphate) is an essential energy donor in various biological processes (eg protein synthesis and gluconeogenesis) and secures several vital regulatory functions in the human body. The study aimed to predict the trends of age-related changes in erythrocyte guanine nucleotides and examine whether competitive sport and related physical training promote beneficial adaptations in erythrocyte guanylate concentrations.

Methods

The study included 86 elite endurance runners (EN) aged 20-81 years, 58 sprint-trained athletes (SP) aged 21-90 years, and 62 untrained individuals (CO) aged 20-68 years.

Results

The concentration of erythrocyte GTP and total guanine nucleotides (TGN) were highest in the SP group, lower in the EN group, and lowest in the CO group. Both athletic groups had higher guanylate energy charge (GEC) values than the CO group (p = 0.012). Concentrations of GTP, TGN, and GEC value significantly decreased, while GDP and GMP concentrations progressively increased with age.

Conclusion

Such a profile of change suggests a deterioration of the GTP-related regulatory function in older individuals. Our study explicitly shows that lifelong sports participation, especially of sprint-oriented nature, allows for maintaining a higher erythrocyte guanylate pool concentration, supporting cells' energy metabolism, regulatory and transcription properties, and thus more efficient overall body functioning.

Metabolomics in aging research: aging markers from organs

Metabolism plays an important role in regulating aging at several levels, and metabolic reprogramming is the main driving force of aging. Due to the different metabolic needs of different tissues, the change trend of metabolites during aging in different organs and the influence of different levels of metabolites on organ function are also different, which makes the relationship between the change of metabolite level and aging more complex. However, not all of these changes lead to aging. The development of metabonomics research has opened a door for people to understand the overall changes in the metabolic level in the aging process of organisms. The omics-based "aging clock" of organisms has been established at the level of gene, protein and epigenetic modifications, but there is still no systematic summary at the level of metabolism. Here, we reviewed the relevant research published in the last decade on aging and organ metabolomic changes, discussed several metabolites with high repetition rate, and explained their role in vivo, hoping to find a group of metabolites that can be used as metabolic markers of aging. This information should provide valuable information for future diagnosis or clinical intervention of aging and age-related diseases.

Heyde Syndrome Complicated by Essential Thrombocythemia: A Case Report

Heyde syndrome is a multisystem disorder characterized by the triad of aortic stenosis (AS), gastrointestinal bleeding, and acquired von Willebrand syndrome. Age-related degeneration is the most common cause of aortic stenosis and is frequently encountered in today's aging society. Approximately 20% of patients with severe aortic stenosis have Heyde syndrome. We encountered an older patient with primary thrombocytosis who was brought to a rural community hospital with bloody stools and was diagnosed with bleeding from an intestinal arteriovenous malformation. A final diagnosis of Heyde syndrome was made based on the presence of severe aortic stenosis and the presence of schistocytes in peripheral blood smears. Valvular diseases can complicate chronic hematological diseases. When the rapid progression of anemia and segmented red blood cells in the peripheral blood are observed in patients with severe aortic stenosis, Heyde syndrome should be considered based on peripheral blood smears and clinical course.

Unexplored Roles of Erythrocytes in Atherothrombotic Stroke

Stroke constitutes the second highest cause of morbidity and mortality worldwide while also impacting the world economy, triggering substantial financial burden in national health systems. High levels of blood glucose, homocysteine, and cholesterol are causative factors for atherothrombosis. These molecules induce erythrocyte dysfunction, which can culminate in atherosclerosis, thrombosis, thrombus stabilization, and post-stroke hypoxia. Glucose, toxic lipids, and homocysteine result in erythrocyte oxidative stress. This leads to phosphatidylserine exposure, promoting phagocytosis. Phagocytosis by endothelial cells, intraplaque macrophages, and vascular smooth muscle cells contribute to the expansion of the atherosclerotic plaque. In addition, oxidative stress-induced erythrocytes and endothelial cell arginase upregulation limit the pool for nitric oxide synthesis, leading to endothelial activation. Increased arginase activity may also lead to the formation of polyamines, which limit the deformability of red blood cells, hence facilitating erythrophagocytosis. Erythrocytes can also participate in the activation of platelets through the release of ADP and ATP and the activation of death receptors and pro-thrombin. Damaged erythrocytes can also associate with neutrophil extracellular traps and subsequently activate T lymphocytes. In addition, reduced levels of CD47 protein in the surface of red blood cells can also lead to erythrophagocytosis and a reduced association with fibrinogen. In the ischemic tissue, impaired erythrocyte 2,3 biphosphoglycerate, because of obesity or aging, can also favor hypoxic brain inflammation, while the release of damage molecules can lead to further erythrocyte dysfunction and death.

Probiotic Foods Are Effective on Weight Loss, Biochemical Parameters, and Intestinal Microbiota in Wistar Albino Rats with Obese Microbiota

The positive effects of various probiotic foods on weight control, intestinal microbiota, and biochemical markers have been proven by various studies. However, there is no study on such effects of tarhana and kefir + tarhana consumption, a type of Turkish food rich in Lactobacillus spp., Pediococcus pentosaceus, Pediococcus acidilactici, and Saccharomyces cerevisiae. This study aimed to determine the changes caused by regular consumption of kefir and/or tarhana for 6 months on weight gain, intestinal microbiota, and biochemical parameters in Wistar albino rats with obese microbiota. Therefore, thirty-five rats were fed with five different methods of oral gavage (n = 7 per group): Normal Diet Control (NDC), High Fat Diet Control (HFDC), 6 mL/kg Kefir + High Fat Diet (Kefir + HFD), 0.2 g/kg Tarhana + High Fat Diet (Tarhana + HFD), and 6 mL/kg Kefir + 0.2 g/kg Tarhana + High Fat Diet (Kefir + Tarhana + HFD). Normality tests were evaluated using the One-Sample Kolmogorov test and Histogram graph. Multiple group comparisons were performed using one-way ANOVA and Tukey's HSD post hoc test, and the statistical significances were indicated by different letters (p < 0.05). Comparisons by gender were performed using the independent samples t-test. Kefir consumption was more effective on decreasing weight gain. Obese microbiota significantly increased blood glucose level and decreased red blood cell (RBC), hematocrit (HCT), hemoglobin, mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), platelets (PLT), and white blood cells. RBC and HCT values in Kefir + HFD, PLT value in Tarhana + HFD, and mean corpuscular volume (MCV), MCH, and MCHC values in Kefir + Tarhana + HFD were higher than those of other groups (p < 0.05). Kefir + tarhana consumption significantly showed an increase in blood glucose. Kefir and/or tarhana induced the abundance of Lactobacillus and blocked the abundances of total coliform bacteria and Escherichia coli (p < 0.05). We demonstrated that kefir was effective in decreasing weight gain, and all dietary interventions induced positive alterations on biochemical findings and intestinal microbiota.