Sodium benzoate attenuates 2,8-dihydroxyadenine nephropathy by inhibiting monocyte/macrophage TNF-α expression

Adenine phosphoribosyltransferase (APRT) deficiency: an increasingly recognized disease

Adenine phosphoribosyltransferase (APRT) deficiency is a rare autosomal recessive disorder which causes high urinary 2,8-dihydroxyadenine (2,8-DHA) excretion, resulting in urolithiasis and crystal nephropathy. It is caused by mutations in the APRT gene. Even though it is an inherited kidney stone disease, the varied clinical presentations, even within a family with the same underlying genetic variants, can lead to delayed diagnosis with some only being recognized in adulthood and even, following a kidney transplant. First presentations include symptoms of reddish-brown diaper stains, urinary tract infections, urolithiasis, acute kidney injury from obstructive uropathy and/or intratubular 2,8-DHA crystallization or kidney failure. Siblings of index cases should be screened for APRT deficiency. An early diagnosis and treatment with xanthine oxidoreductase inhibitors (XORi) can preserve kidney function and/or prevent progressive kidney injury and kidney failure. In this review, we will discuss the pathophysiology, clinical presentations, investigations, and management of APRT deficiency.

Microbiome-derived metabolite effects on intestinal barrier integrity and immune cell response to infection

The gut microbiota exerts a significant influence on human health and disease. While compositional changes in the gut microbiota in specific diseases can easily be determined, we lack a detailed mechanistic understanding of how these changes exert effects at the cellular level. However, the putative local and systemic effects on human physiology that are attributed to the gut microbiota are clearly being mediated through molecular communication. Here, we determined the effects of gut microbiome-derived metabolites l-tryptophan, butyrate, trimethylamine (TMA), 3-methyl-4-(trimethylammonio)butanoate (3,4-TMAB), 4-(trimethylammonio)pentanoate (4-TMAP), ursodeoxycholic acid (UDCA), glycocholic acid (GCA) and benzoate on the first line of defence in the gut. Using in vitro models of intestinal barrier integrity and studying the interaction of macrophages with pathogenic and non-pathogenic bacteria, we could ascertain the influence of these metabolites at the cellular level at physiologically relevant concentrations. Nearly all metabolites exerted positive effects on barrier function, but butyrate prevented a reduction in transepithelial resistance in the presence of the pathogen Escherichia coli, despite inducing increased apoptosis and exerting increased cytotoxicity. Induction of IL-8 was unaffected by all metabolites, but GCA stimulated increased intra-macrophage growth of E. coli and tumour necrosis-alpha (TNF-α) release. Butyrate, 3,4-TMAB and benzoate all increased TNF-α release independent of bacterial replication. These findings reiterate the complexity of understanding microbiome effects on host physiology and underline that microbiome metabolites are crucial mediators of barrier function and the innate response to infection. Understanding these metabolites at the cellular level will allow us to move towards a better mechanistic understanding of microbiome influence over host physiology, a crucial step in advancing microbiome research.

Long-term abuse of caffeine sodium benzoate induces endothelial cells injury and leads to coagulation dysfunction

Our hospital admitted a patient who had difficulty in coagulation even after blood replacement, and the patient had abused caffeine sodium benzoate (CSB) for more than 20 years. Hence, we aimed to explore whether CSB may cause dysfunction in vascular endothelial cells and its possible mechanism. Low, medium, and high concentrations of serum of long-term CSB intake patients were used to treat HUVECs, with LPS as the positive control. MTT and CCK8 were performed to verify CSB's damaging effect on HUVECs. The expression of ET-1, ICAM-1, VCAM-1, and E-selectin were measured by ELISA. TUNEL assay and Matrigel tube formation assay were carried out to detect apoptosis and angiogenesis of HUVECs. Flow cytometry was applied to analyze cell cycles and expression of CD11b, PDGF, and ICAM-1. Expression of PDGF-BB and PCNA were examined by western blot. The activation of MAPK signaling pathway was detected by qRT-PCR and western blot. Intracellular Ca2+ density was detected by fluorescent probes. CCK8 assay showed high concentration of CSB inhibited cell viability. Cell proliferation and angiogenesis were inhibited by CSB. ET-1, ICAM-1, VCAM-1, and E-selectin upregulated in CSB groups. CSB enhanced apoptosis of HUVECs. CD11b, ICAM-1 increased and PDGF reduced in CSB groups. The expression level and phosphorylation level of MEK, ERK, JUN, and p38 in MAPK pathway elevated in CSB groups. The expression of PCNA and PDGF-BB was suppressed by CSB. Intracellular Ca2+ intensity was increased by CSB. Abuse of CSB injured HUVECs and caused coagulation disorders.

Elucidating the Mechanisms of Sodium Benzoate in Alzheimer Disease: Insights from Quantitative Proteomics Analysis of Serum Samples

BACKGROUND

N-methyl-D-aspartate receptors (NMDARs) are crucial components of brain function involved in memory and neurotransmission. Sodium benzoate is a promising NMDAR enhancer and has been proven to be a novel, safe, and efficient therapy for patients with Alzheimer disease (AD). However, in addition to the role of sodium benzoate as an NMDA enhancer, other mechanisms of sodium benzoate in treating AD are still unclear. To elucidate the potential mechanisms of sodium benzoate in Alzheimer disease, this study employed label-free quantitative proteomics to analyze serum samples from AD cohorts with and without sodium benzoate treatment.

METHODS

The serum proteins from each patient were separated into 24 fractions using an immobilized pH gradient, digested with trypsin, and then subjected to nanoLC‒MS/MS to analyze the proteome of all patients. The nanoLC‒MS/MS data were obtained with a label-free quantitative proteomic approach. Proteins with fold changes were analyzed with STRING and Cytoscape to find key protein networks/processes and hub proteins.

RESULTS

Our analysis identified 861 and 927 protein groups in the benzoate treatment cohort and the placebo cohort, respectively. The results demonstrated that sodium benzoate had the most significant effect on the complement and coagulation cascade pathways, amyloidosis disease, immune responses, and lipid metabolic processes. Moreover, Transthyretin, Fibrinogen alpha chain, Haptoglobin, Apolipoprotein B-100, Fibrinogen beta chain, Apolipoprotein E, and Alpha-1-acid glycoprotein 1 were identified as hub proteins in the protein‒protein interaction networks.

CONCLUSIONS

These findings suggest that sodium benzoate may exert its influence on important pathways associated with AD, thus contributing to the improvement in the pathogenesis of the disease.