Anti-Hyperuricemic Effect of Anserine Based on the Gut-Kidney Axis: Integrated Analysis of Metagenomics and Metabolomics

Research progress on the mechanism of hyperuricemic nephropathy based on multi-omics technique: A review

Hyperuricemic nephropathy is a metabolic disease in which renal uric acid deposition and excretion are impaired due to elevated levels of uric acid in the blood, leading to impaired renal tubule function and chronic renal disease. Hyperuricemic nephropathy is one of the important complications of hyperuricemia, which seriously affects the quality of life and prognosis of patients. The pathogenesis of hyperuricemic nephropathy involves a variety of factors, including: amino acid metabolism disorder, energy metabolism abnormality, increased nucleotide metabolism, lipid metabolism disorder and bile acid metabolism imbalance, REDOX process disorder, cell cycle and apoptosis imbalance, signal transduction and inflammatory response enhancement, and intestinal flora imbalance. In recent years, omics techniques such as metabolomics, transcriptomics and intestinal microecology have been used to reveal the metabolic, gene and microflora characteristics of hyperuricemic nephropathy from different levels, as well as their interactions and regulatory mechanisms. This paper reviews these studies, analyzes the existing problems and challenges, and puts forward future research directions and suggestions, aiming at providing new theoretical basis and practical guidance for the prevention and treatment of hyperuricemic nephropathy.

Resveratrol Butyrate Esters Reduce Hypertension in a Juvenile Rat Model of Chronic Kidney Disease Exacerbated by Microplastics

BACKGROUND

Resveratrol is recognized as a promising nutraceutical with antihypertensive and prebiotic properties; however, its bioavailability in vivo is limited. To enhance its bioactivity, we developed resveratrol butyrate esters (RBEs). This study investigates whether RBEs can mitigate hypertension induced by chronic kidney disease (CKD) and exacerbated by microplastics (MPs) exposure in juvenile rats.

METHODS

Three-week-old male Sprague Dawley rats were fed either regular chow or 0.5% adenine chow for three weeks. The adenine-fed CKD rats (N = 8 per group) received either 5 μM MPs (10 mg/L) or MPs combined with RBE (25 mg/L) in their drinking water from weeks 3 to 9.

RESULTS

Our results indicate that MP exposure worsened CKD-induced hypertension, while RBE treatment resulted in a reduction in systolic BP by 15 mmHg (155 ± 2 mmHg vs. 140 ± 1 mmHg, p < 0.05). The combined exposure to adenine and MPs was associated with nitric oxide (NO) deficiency, which RBE treatment alleviated. Additionally, our findings revealed that RBE modulated both the classical and nonclassical renin-angiotensin system (RAS), contributing to its protective effects. We also observed changes in gut microbiota composition, increased butyric acid levels, and elevated renal GPR41 expression associated with RBE treatment.

CONCLUSIONS

In conclusion, in this juvenile rat model of combined CKD and MP exposure, RBE demonstrates antihypertensive effects by modulating NO levels, the RAS, gut microbiota, and their metabolites.

Analysis of metagenome and metabolome disclosed the mechanisms of Dendrobium officinale polysaccharide on DSS-induced ulcerative colitis-affected mice

Currently, there is no known cause for ulcerative colitis (UC), an inflammatory bowel disease that is difficult to treat. This assay aimed to investigate the protective effects and mechanisms of Dendrobium officinale polysaccharide (DOP) in mice with acute UC induced by dextran sulphate sodium (DSS). We found that DOP could improve weight loss, decrease the disease activity index (DAI), and regulate the release of interleukin 2 (IL-2), IL-4, IL-6, and IL-10 in DSS-induced acute UC mice. Additionally, DOP preserved the integrity of the intestinal barrier in UC mice by increasing goblet cell density and maintaining tight junctions. DOP significantly enhanced total antioxidant capacity (T-AOC), and reduced glutathione (GSH), nitric oxide (NO), and malondialdehyde (MDA) levels in the bloodstream. In terms of serum biochemistry, DOP markedly elevated levels of bilirubin (BIL), alkaline phosphatase (ALP), total bile acid (TBA), creatinine (Crea), and creative kinase isoenzyme (CKMB). Furthermore, DOP increased the relative abundance of Lactobacillales. DOP also improved intestinal health and stimulated the synthesis of potent anti-inflammatory and antiviral substances by regulating the metabolism of purines, prostaglandins, and leukotrienes. Therefore, DOP can be considered a functional dietary supplement for the treatment of UC, as it improves the condition of DSS-induced UC mice.

Reposition: Focalizing β-Alanine Metabolism and the Anti-Inflammatory Effects of Its Metabolite Based on Multi-Omics Datasets

The incorporation of multi-omics data methodologies facilitates the concurrent examination of proteins, metabolites, and genes associated with inflammation, thereby leveraging multi-dimensional biological data to achieve a comprehensive understanding of the complexities involved in the progression of inflammation. Inspired by ensemble learning principles, we implemented ID normalization preprocessing, categorical sampling homogenization, and pathway enrichment across each sample matrix derived from multi-omics datasets available in the literature, directing our focus on inflammation-related targets within lipopolysaccharide (LPS)-stimulated RAW264.7 cells towards β-alanine metabolism. Additionally, through the use of LPS-treated RAW264.7 cells, we tentatively validated the anti-inflammatory properties of the metabolite Ureidopropionic acid, originating from β-alanine metabolism, by evaluating cell viability, nitric oxide production levels, and mRNA expression of inflammatory biomarkers. In conclusion, our research represents the first instance of an integrated analysis of multi-omics datasets pertaining to LPS-stimulated RAW264.7 cells as documented in the literature, underscoring the pivotal role of β-alanine metabolism in cellular inflammation and successfully identifying Ureidopropionic acid as a novel anti-inflammatory compound. Moreover, the findings from database predictions and molecular docking studies indicated that the inflammatory-related pathways and proteins may serve as potential mechanistic targets for Ureidopropionic acid.

Leech Poecilobdella manillensis protein extract ameliorated hyperuricemia by restoring gut microbiota dysregulation and affecting serum metabolites

BACKGROUND

Hyperuricemia (HUA) is a public health concern that needs to be solved urgently. The lyophilized powder of Poecilobdella manillensis has been shown to significantly alleviate HUA; however, its underlying metabolic regulation remains unclear.

AIM

To explore the underlying mechanisms of Poecilobdella manillensis in HUA based on modulation of the gut microbiota and host metabolism.

METHODS

A mouse model of rapid HUA was established using a high-purine diet and potassium oxonate injections. The mice received oral drugs or saline. Additionally, 16S rRNA sequencing and ultra-high performance liquid chromatography with quadrupole time-of-flight mass spectrometry-based untargeted metabolomics were performed to identify changes in the microbiome and host metabolome, respectively. The levels of uric acid transporters and epithelial tight junction proteins in the renal and intestinal tissues were analyzed using an enzyme-linked immunosorbent assay.

RESULTS

The protein extract of Poecilobdella manillensis lyophilized powder (49 mg/kg) showed an enhanced anti-trioxypurine ability than that of allopurinol (5 mg/kg) (P < 0.05). A total of nine bacterial genera were identified to be closely related to the anti-trioxypurine activity of Poecilobdella manillensis powder, which included the genera of Prevotella, Delftia, Dialister, Akkermansia, Lactococcus, Escherichia_Shigella, Enterococcus, and Bacteroides. Furthermore, 22 metabolites in the serum were found to be closely related to the anti-trioxypurine activity of Poecilobdella manillensis powder, which correlated to the Kyoto Encyclopedia of Genes and Genomes pathways of cysteine and methionine metabolism, sphingolipid metabolism, galactose metabolism, and phenylalanine, tyrosine, and tryptophan biosynthesis. Correlation analysis found that changes in the gut microbiota were significantly related to these metabolites.

CONCLUSION

The proteins in Poecilobdella manillensis powder were effective for HUA. Mechanistically, they are associated with improvements in gut microbiota dysbiosis and the regulation of sphingolipid and galactose metabolism.

Understanding Hyperuricemia: Pathogenesis, Potential Therapeutic Role of Bioactive Peptides, and Assessing Bioactive Peptide Advantages and Challenges

Hyperuricemia is a medical condition characterized by an elevated level of serum uric acid, closely associated with other metabolic disorders, and its global incidence rate is increasing. Increased synthesis or decreased excretion of uric acid can lead to hyperuricemia. Protein peptides from various food sources have demonstrated potential in treating hyperuricemia, including marine organisms, ovalbumin, milk, nuts, rice, legumes, mushrooms, and protein-rich processing by-products. Through in vitro experiments and the establishment of cell or animal models, it has been proven that these peptides exhibit anti-hyperuricemia biological activities by inhibiting xanthine oxidase activity, downregulating key enzymes in purine metabolism, regulating the expression level of uric acid transporters, and restoring the composition of the intestinal flora. Protein peptides derived from food offer advantages such as a wide range of sources, significant therapeutic benefits, and minimal adverse effects. However, they also face challenges in terms of commercialization. The findings of this review contribute to a better understanding of hyperuricemia and peptides with hyperuricemia-alleviating activity. Furthermore, they provide a theoretical reference for developing new functional foods suitable for individuals with hyperuricemia.

Gut-Kidney-Heart: A Novel Trilogy

The microbiota represents a key factor in determining health and disease. Its role in inflammation and immunological disorders is well known, but it is also involved in several complex conditions, ranging from neurological to psychiatric, from gastrointestinal to cardiovascular diseases. It has recently been hypothesized that the gut microbiota may act as an intermediary in the close interaction between kidneys and the cardiovascular system, leading to the conceptualization of the "gut-kidney-heart" axis. In this narrative review, we will discuss the impact of the gut microbiota on each system while also reviewing the available data regarding the axis itself. We will also describe the role of gut metabolites in this complex interplay, as well as potential therapeutical perspectives.