Dietary supplementation with L-lysine affects body weight and blood hematological and biochemical parameters in rats

Genomic analysis uncovers that cold-inducible RNA binding protein is associated with estrogen receptor in breast cancer

BACKGROUND

RNA-binding proteins (RBPs) perform various biological functions in humans and are associated with several diseases, including cancer. Therefore, RBPs have emerged as novel therapeutic targets. Although recent investigations have shown that RBPs have crucial functions in breast cancer (BC), detailed research is underway to determine the RBPs that are closely related to cancers.

OBJECTIVE

To provide an insight into estrogen receptor (ER) regulation by cold-inducible RNA binding protein (CIRBP) as a novel therapeutic target.

RESULTS

By analyzing the genomic data, we identified a potential RBP in BC. We found that CIRBP is highly correlated with ER function and influences clinical outcomes, such as patient survival and endocrine therapy responsiveness. In addition, CIRBP influences the proliferation of BC cells by directly binding to ER-RNA.

CONCLUSION

Our results suggest that CIRBP is a novel upstream regulator of ER and that the interplay between CIRBP and ER may be associated with the clinical relevance of BC.

Gut Microbiota as Predictive Biomarker for Chronic Heart Failure in Patients with Different Nutritional Risk

To examine the relationship between gut microbiota and disease development in chronic heart failure patients with different nutritional risk. The study analyzed stool samples from 62 CHF patients and 21 healthy peoples using 16S rRNA gene sequencing. CHF patients were separated into risk (n = 30) and non-risk group (n = 32) based on NRS2002 scores. Analysis methods used were LEfSe, random forest regression model, ROC curves, BugBase, PICRUSt2, metagenomeSeq. Risk group includes 11 cases of HFrEF, 6 cases of HFpEF, and 13 cases of HFmrEF. LefSe analysis confirmed that the risk group had higher levels of Enterobacter and Escherichia-Shigella. Correlation analysis revealed a negative correlation between prealbumin and Escherichia-Shigella. The presence of Enterobacter and Escherichia-Shigella worsens intestinal inflammation in CHF patients, impacting lysine metabolism by influencing its degradation metabolic function. This interference further disrupts albumin and prealbumin synthesis, leading to malnutrition in CHF patients and ultimately worsening the disease.

L-lysine dietary supplementation for childhood and adolescent growth: Promises and precautions

BACKGROUND

L-lysine (lysine) is an essential amino acid that plays a vital role in human nutrition. It serves as a key component in protein synthesis and fulfills critical roles in various physiological activities. For decades, lysine supplements have been extensively used to promote the growth and development of children, particularly in developing countries where cereal-based diets are everyday staples.

AIM OF THE REVIEW

This review aims to provide an overview of the overall effectiveness of lysine supplements concerning the growth of children and adolescents. Additionally, it addresses the potential precautions that should be considered when using lysine supplements in this context.

KEY SCIENTIFIC CONCEPTS OF REVIEW

Receiving lysine oral supplements and lysine-fortified cereal diets were observed to enhance nitrogen retention and improve anthropometric measurements such as height, weight, Z-scores, body mass index, and skinfold thickness. Furthermore, lysine positively influenced the children's developmental quotient and various serological biochemical parameters, such as hormones, immunological indicators, proteins, bone metabolic indicators, and red blood cell parameters. These supplements are generally considered clinically safe, with no reported toxicity where the related side effects are limited to subjective gastrointestinal tract symptoms. It is essential to be cautious about excessive intake of lysine, as it can lead to an imbalance of amino acids, thereby potentially suppressing its intended benefits. When used with appropriate precautions, lysine can serve as a safe supplement with promising benefits for the growth of children and adolescents. Nevertheless, further contemporary research studies on lysine supplementation would be insightful and valuable in better understanding its optimal use, potential benefits, and safety in promoting growth.

ANXA9 facilitates S100A4 and promotes breast cancer progression through modulating STAT3 pathway

Breast cancer has the highest global incidence and mortality rates among all cancer types. Abnormal expression of the Annexin family has been observed in different malignant tumors, including upregulated ANXA9 in breast cancer. We found highly expressed ANXA9 in metastatic breast cancer tissues, which is correlated with breast cancer progression. In vitro, the functional experiments indicated ANXA9 influenced breast cancer proliferation, motility, invasion, and apoptosis; in vivo, downregulation of ANXA9 suppressed breast cancer xenograft tumor growth and lung metastasis. Mechanically, on one side, we found that ANXA9 could mediate S100A4 and therefore regulate AKT/mTOR/STAT3 pathway to participate p53/Bcl-2 apoptosis; on the other side, we found ANXA9 transferred S100A4 from cells into the tumor microenvironment and mediated the excretion of cytokines IL-6, IL-8, CCL2, and CCL5 to participate angiogenesis via self- phosphorylation at site Ser2 and site Thr69. Our findings demonstrate significant involvement of ANXA9 in promoting breast cancer progression, thereby suggesting that therapeutic intervention via targeting ANXA9 may be effective in treating metastatic breast cancer.

Maternal serum amino acid levels as predictors of premature rupture of membranes: A comprehensive analysis

INTRODUCTION

The aim of this study is to investigate the association between altered maternal serum amino acids (AAs) levels and premature rupture of membranes (pPROM) in pregnant women.

METHODS

We conducted a case-control study involving 60 pregnant women diagnosed with pPROM and 60 healthy pregnant women as controls. Amino acid levels were quantified using high-performance liquid chromatography. Receiver operating characteristic (ROC) curve analysis was performed to determine the predictive capability of specific AAs for pPROM.

RESULTS

Our findings revealed that lysine, glycine, and glutamic acid levels were significantly elevated in the pPROM group compared with the control group. Lysine, with a threshold value exceeding 137.90 μmol/L, exhibited the highest predictive accuracy, with an area under the curve (AUC) of 0.796 (p < 0.001), sensitivity of 66.7 %, and specificity of 80.0 %. Glycine, with a cut-off value of >242.48 μmol/L, had an AUC of 0.789 (p < 0.001), sensitivity of 83.3 %, and specificity of 65.0 %. Glutamic acid, at a threshold of 111.40 μmol/L, demonstrated an AUC of 0.787 (p < 0.001), sensitivity of 88.3 %, and specificity of 65.0 %. These AAs could effectively predict the occurrence of pPROM.

CONCLUSION

Elevated blood levels of lysine, glycine, and glutamic acid were found to be associated with pPROM. These AAs serve as potential predictive biomarkers for pPROM, with lysine showing the highest AUC and sensitivity. Identifying such biomarkers may contribute to the development of non-invasive diagnostic tools for pPROM risk assessment, enabling timely interventions and improved maternal and fetal outcomes.

L-Lysine supplementation affects dietary protein quality and growth and serum amino acid concentrations in rats

Single amino acid (AA) supplementations in foods are increasing, however their potential nutritional and physiological impacts are not fully understood. This study examined the effects of L-lysine (Lys) supplementation on protein quality of diets, serum AA concentrations and associations between the ratio of supplemental Lys to dietary protein (X) with body weight gain (BWG) in Sprague-Dawley male rats. Rats were fed one of 10 diets containing either 7% or 20% casein and supplemented with 0% (Control), 1.5%, 3%, 6% Lys or 6% Lys + 3% L-arginine (Arg) (8 rats/diet group) for 1 week. Lys supplementation reduced the protein quality of the casein-based diets (p < 0.01). BWG was reduced by supplemental Lys when X > 0.18. Free Lys supplementation dose-dependently increased serum Lys levels (p < 0.01), while increased protein-bound Lys (1.4% vs 0.52%) had little effect on serum Lys (p > 0.05). In the 7% casein diets, ≥ 1.5% supplemental Lys reduced serum alanine, asparagine, glycine, isoleucine, leucine, serine, tyrosine, valine, carnitine, ornithine, and increased urea. Supplementation of ≥ 3% Lys additionally reduced tryptophan and increased histidine, methionine and α-aminoadipic acid (α-AAA) compared to the Control (p < 0.05). In the 20% casein diets, addition of ≥ 1.5% Lys reduced serum asparagine and threonine, and ≥ 3% Lys reduced leucine, proline, tryptophan, valine, and ornithine, and 6% Lys reduced carnitine, and increased histidine, methionine, and α-AAA. Overall, this study showed that free Lys supplementation in a Lys-sufficient diet reduced the protein quality of the diets and modified the serum concentrations of many amino acids. Excess free Lys intake adversely affected growth and utilization of nutrients due to AA imbalance or antagonism. Overall lower protein intake increases susceptibility to the adverse effects of Lys supplementation.

Shuttle between arginine and lysine: influence on cancer immunonutrition

Amino acids which are essential nutrients for all cell types' survival are also recognised to serve as opportunistic/alternative fuels in cancers auxotrophic for specific amino acids. Accordingly, restriction of amino acids has been utilised as a therapeutic strategy in these cancers. Contrastingly, amino acid deficiencies in cancer are found to greatly impair immune functions, increasing mortality and morbidity rates. Dietary and supplemental amino acids in such conditions have revealed their importance as 'immunonutrients' by modulating cellular homeostasis processes and halting malignant progression. L-arginine specifically has attracted interest as an immunonutrient by acting as a nodal regulator of immune responses linked to carcinogenesis processes through its versatile signalling molecule, nitric oxide (NO). The quantum of NO generated directly influences the cytotoxic and cytostatic processes of cell cycle arrest, apoptosis, and senescence. However, L-lysine, a CAT transporter competitor for arginine effectively limits arginine input at high L-lysine concentrations by limiting arginine-mediated effects. The phenomenon of arginine-lysine antagonism can, therefore, be hypothesised to influence the immunonutritional effects exerted by arginine. The review highlights aspects of lysine's interference with arginine-mediated NO generation and its consequences on immunonutritional and anti-cancer effects, and discusses possible alternatives to manage the condition. However, further research that considers monitoring lysine levels in arginine immunonutritional therapy is essential to conclude the hypothesis.

Lysine Deprivation Suppresses Adipogenesis in 3T3-L1 Cells: A Transcriptome Analysis

Growing evidence proves that amino acid restriction can reverse obesity by reducing adipose tissue mass. Amino acids are not only the building blocks of proteins but also serve as signaling molecules in multiple biological pathways. The study of adipocytes' response to amino acid level changes is crucial. It has been reported that a low concentration of lysine suppresses lipid accumulation and transcription of several adipogenic genes in 3T3-L1 preadipocytes. However, the detailed lysine-deprivation-induced cellular transcriptomic changes and the altered pathways have yet to be fully studied. Here, using 3T3-L1 cells, we performed RNA sequencing on undifferentiated and differentiated cells, and differentiated cells under a lysine-free environment, and the data were subjected to KEGG enrichment. We found that the differentiation process of 3T3-L1 cells to adipocytes required the large-scale upregulation of metabolic pathways, mainly on the mitochondrial TCA cycle, oxidative phosphorylation, and downregulation of the lysosomal pathway. Single amino acid lysine depletion suppressed differentiation dose dependently. It disrupted the metabolism of cellular amino acids, which could be partially reflected in the changes in amino acid levels in the culture medium. It inhibited the mitochondria respiratory chain and upregulated the lysosomal pathway, which are essential for adipocyte differentiation. We also noticed that cellular interleukin 6 (IL6) expression and medium IL6 level were dramatically increased, which was one of the targets for suppressing adipogenesis induced by lysine depletion. Moreover, we showed that the depletion of some essential amino acids such as methionine and cystine could induce similar phenomena. This suggests that individual amino acid deprivation may share some common pathways. This descriptive study dissects the pathways for adipogenesis and how the cellular transcriptome was altered under lysine depletion.

Lysine or Threonine Deficiency Decreases Body Weight Gain in Growing Rats despite an Increase in Food Intake without Increasing Energy Expenditure in Response to FGF21

The objective of this study is to evaluate the effects of a strictly essential amino acid (lysine or threonine; EAA) deficiency on energy metabolism in growing rats. Rats were fed for three weeks severely (15% and 25% of recommendation), moderately (40% and 60%), and adequate (75% and 100%) lysine or threonine-deficient diets. Food intake and body weight were measured daily and indirect calorimetry was performed the week three. At the end of the experimentation, body composition, gene expression, and biochemical analysis were performed. Lysine and threonine deficiency induced a lower body weight gain and an increase in relative food intake. Lysine or threonine deficiency induced liver FGF21 synthesis and plasma release. However, no changes in energy expenditure were observed for lysine deficiency, unlike threonine deficiency, which leads to a decrease in total and resting energy expenditure. Interestingly, threonine severe deficiency, but not lysine deficiency, increase orexigenic and decreases anorexigenic hypothalamic neuropeptides expression, which could explain the higher food intake. Our results show that the deficiency in one EAA, induces a decrease in body weight gain, despite an increased relative food intake, without any increase in energy expenditure despite an induction of FGF21.

Anxiolytic, anti-nociceptive and body weight reducing effects of L-lysine in rats: Relationship with brain serotonin an In-Vivo and In-Silico study

L-lysine (L-lys) had long been comprehended as an essential amino acid for humans. There were reports that the absence or inadequate availability of L-lys in the diet may lead to mental and physical impairments. The present study was designed to explore the effects of L-lys on body weight changes, cumulative food intake, anxiety-like behavior and pain perception in rats. 5-Hydroxytryptamine (5-HT, serotonin) metabolism, and tryptophan (Trp) levels in the midbrain (MB), hippocampus (HP), and prefrontal cortex (PFC) were also determined. Animals were treated with L-lys in doses of 0.5 g/kg and 1 g/kg for 20 days and behavioral studies were performed on day 1st and day 20th. After monitoring behaviors on day 20th, animals were killed to collect the serum and brain regions MB, HP and PFC. 5-HT metabolism and Trp levels were determined by HPLC-EC. The treatment produce no effect on food intakes but body weights were reduced. 20 days administration of L-lys produced an anxiolytic effect and increased exploratory activity on day 1st. Repeated administration of L-lys increased 5-HT levels in the PFC and HP. 5-Hydroxyindoleacetic acid (5-HIAA), the metabolite of 5-HT, decreased in the HP. Trp, the precourser of 5-HT, decreased in the PFC. Results suggested a decrease in 5-HT degredation in enhancing 5-HT levels. Results of in-silico analysis showed that lysine had a potential binding affinity for MAO (monoamine oxidase) A and B with an energy of (-4.8 kcal/mol and -5.3 kcal/mol) respectively. The molecular dynamic simulation study revealed the stability of L-lys after 10 ns for each protein. Conclusively, the present study showed that L-lys produced an anxiolytic effect and reduced body weight. These beneficial effects were associated with an increase in 5-HT levels in the PFC and HP. In-silico analysis suggested that 5-HT increase were due to the binding of L-lys with MAOs resulting in an inhibition of the degradation of monoamine.

Impacts of essential amino acids on energy balance

BACKGROUND

Obesity develops due to an imbalance in energy homeostasis, wherein energy intake exceeds energy expenditure. Accumulating evidence shows that manipulations of dietary protein and their component amino acids affect the energy balance, resulting in changes in fat mass and body weight. Amino acids are not only the building blocks of proteins but also serve as signals regulating multiple biological pathways.

SCOPE OF REVIEW

We present the currently available evidence regarding the effects of dietary alterations of a single essential amino acid (EAA) on energy balance and relevant signaling mechanisms at both central and peripheral levels. We summarize the association between EAAs and obesity in humans and the clinical use of modifying the dietary EAA composition for therapeutic intervention in obesity. Finally, similar mechanisms underlying diets varying in protein levels and diets altered of a single EAA are described. The current review would expand our understanding of the contribution of protein and amino acids to energy balance control, thus helping discover novel therapeutic approaches for obesity and related diseases.

MAJOR CONCLUSIONS

Changes in circulating EAA levels, particularly increased branched-chain amino acids (BCAAs), have been reported in obese human and animal models. Alterations in dietary EAA intake result in improvements in fat and weight loss in rodents, and each has its distinct mechanism. For example, leucine deprivation increases energy expenditure, reduces food intake and fat mass, primarily through regulation of the general control nonderepressible 2 (GCN2) and mammalian target of rapamycin (mTOR) signaling. Methionine restriction by 80% decreases fat mass and body weight while developing hyperphagia, primarily through fibroblast growth factor 21 (FGF-21) signaling. Some effects of diets with different protein levels on energy homeostasis are mediated by similar mechanisms. However, reports on the effects and underlying mechanisms of dietary EAA imbalances on human body weight are few, and more investigations are needed in future.

Dynamic Analysis of Major Components in the Different Developmental Stages of Tenebrio molitor

The yellow mealworm, Tenebrio molitor, is an important resource insect with a high protein percentage that is widely farmed in many countries. In this study, the content dynamics for protein, fat, chitin, and other components in the whole development process of yellow mealworms were analyzed by sampling from different instars and combining with their growth conditions. The results of the component dynamic analyses in the different development stages showed that the percentages of protein, fat, and chitin were the highest in the larval stage, pupal stage, and adult stage, respectively. The results of amino acid composition dynamic analysis also indicated comparatively higher essential amino acids in the earlier instar (e.g., before the 9th instar) larvae. Therefore, we found that the earlier instar is better than the final instar as the insect farming harvest time. Furthermore, the larvae in the earlier instar consumed dramatically less feed and could effectively reduce the farming costs of insect farmers. This finding provides an alternative option to farm insects for different purposes and in an economic way.

Association between dietary essential amino acids intake and metabolic biomarkers: influence of obesity among Chinese children and adolescents

Essential amino acids (EAAs) are involved in growth and development in children and adolescents. This study was aimed at exploring the relationship between dietary EAA intakes and metabolic biomarker, and the influence of obesity in children and adolescents. A total of 3566 subjects were analysed. Participators were classified according to weight status. Metabolic biomarkers were determined using standardized methods and conditions. Normal, overweight, and obesity statuses were defined according to the Working Group on Obesity in China (WGOC) BMI cutoff points based on age- and sex-specific screening criteria. In normal-weight group, blood uric acid was negatively correlated with dietary Ile, Leu, Lys, Phe, Thr, Val, and His, and zinc was negatively correlated with Ile, Leu, Lys, Phe, Thr, Val, His, Met, and Trp. In overweight group, TC was negatively correlated with Ile, Leu, Phe, Val, and His, and LDL-C was negatively correlated with Ile, Leu, Lys, Phe, Thr, Val, His, and Met, while TG was positively correlated with Leu, Lys, Phe, Thr, Val, and Met. In obesity group, hemoglobin was positively related to Ile, Leu, Lys, Phe, Thr, Val, His, and Trp, while vitamin D was positively correlated with His and Trp. The serum creatinine was negatively correlated with Ile, Leu, Phe, Val, His, and Met in normal-weight group, and positively correlated with Ile, Leu, Lys, Phe, Thr, Val, His, Met, Trp, His, and Trp in obesity group. Dietary amino acid score (AAS) and Leu intake were protective factors for obesity. The association between fasting blood glucose and EAAs intake was weak and labile. Metabolic biomarkers and EAA intakes were only related under certain weight status. The dietary AAS is positively correlated with HDL-C, LDL-C, serum creatinine, albumin, serum vitamin D, and zinc. The subtle relationship of EAAs and kidney function should be explored further. There is a complex relationship between EAAs and metabolic biomarkers, and overweight and obesity have a certain influence on this relationship.