Prophylactic glycine administration attenuates pancreatic damage and inflammation in experimental acute pancreatitis

Therapeutic potential of plant polyphenols in acute pancreatitis

Acute pancreatitis is a potentially life-threatening inflammatory disorder of the exocrine pancreas characterized by early activation of pancreatic enzymes followed by macrophage-driven inflammation, and pancreatic acinar cell death. The most common causes are gallstones and excessive alcohol consumption. Inflammation and oxidative stress play critical roles in its pathogenesis. Despite increasing incidence, currently, no specific drug therapy is available to treat or prevent acute pancreatitis, in particular severe acute pancreatitis. New therapeutic agents are very much needed. Plant polyphenols have attracted extensive attention in the field of acute pancreatitis due to their diverse pharmacological properties. In this review, we discuss the potential of plant polyphenols in inhibiting the occurrence and development of acute pancreatitis via modulation of inflammation, oxidative stress, calcium overload, autophagy, and apoptosis, based on the currently available in vitro, in vivo animal and very few clinical human studies. We also outline the opportunities and challenges in the clinical translation of plant polyphenols for the treatment of the disease. We concluded that plant polyphenols have a potential therapeutic effect in the management and treatment of acute pancreatitis. Knowledge gained from this review will hopefully inspire new research ideas and directions for the development and application of plant polyphenols for treating this disease.

Integrating metagenomics with metabolomics for gut microbiota and metabolites profiling in acute pancreatitis

Acute pancreatitis (AP) is an inflammatory disease of the pancreas. Despite of a steadily increasing in morbidity and mortality, there is still no effective therapy. Gut microbial dysbiosis and its derived-metabolites disorder have been shown to play an important role in the development of AP, however, little is known regarding the crosstalk between gut microbiota and metabolites. In this study, we assessed the alterations in gut microbiota and metabolites by constructing three AP mouse models by means of metagenomic and metabolomic sequencing, and further clarified their relationship by correlation analysis. The results revealed that each model exhibited unique flora and metabolite profiles. KEGG analysis showed that the differential flora and metabolite-enriched pathway functions were correlated with lipid metabolism and amino acid metabolism. Moreover, two core differential bacterial species on Burkholderiales bacterium YL45 and Bifidobacterium pseudolongum along with eleven differential metabolites appeared to exert certain effects during the course of AP. In conclusion, further exploration of the crosstalk between microbiota and derived metabolites may provide novel insights and strategies into the diagnosis and treatment of AP.

Host metabolome predicts the severity and onset of acute toxicities induced by CAR T-cell therapy

Anti-CD19 chimeric antigen receptor (CAR) T-cell therapy is a highly effective treatment option for patients with relapsed/refractory large B-cell lymphoma. However, widespread use is deterred by the development of clinically significant acute inflammatory toxicities, including cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS), that induce significant morbidity and require close monitoring. Identification of host biochemical signatures that predict the severity and time-to-onset of CRS and ICANS may assist patient stratification to enable timely mitigation strategies. Here, we report pretreatment host metabolites that are associated with CRS and ICANS induced by axicabtagene ciloleucel or tisagenlecleucel therapy. Both untargeted metabolomics analysis and validation using targeted assays revealed a significant association between the abundance of specific pretreatment biochemical entities and an increased risk and/or onset of clinically significant CRS (q < .1) and ICANS (q < .25). Higher pretreatment levels of plasma glucose and lower levels of cholesterol and glutamate were associated with a faster onset of CRS. In contrast, low baseline levels of the amino acids proline and glycine and the secondary bile acid isoursodeoxycholate were significantly correlated with clinically significant CRS. Lower concentration of the amino acid hydroxyproline was associated with higher grade and faster onset of ICANS, whereas low glutamine was negatively correlated with faster development of ICANS. Overall, our data indicate that the pretreatment host metabolome has biomarker potential in determining the risk of clinically significant CRS and ICANS, and may be useful in risk stratification of patients before anti-CD19 CAR T-cell therapy.

Glycine: The Smallest Anti-Inflammatory Micronutrient

Glycine is a non-essential amino acid with many functions and effects. Glycine can bind to specific receptors and transporters that are expressed in many types of cells throughout an organism to exert its effects. There have been many studies focused on the anti-inflammatory effects of glycine, including its abilities to decrease pro-inflammatory cytokines and the concentration of free fatty acids, to improve the insulin response, and to mediate other changes. However, the mechanism through which glycine acts is not clear. In this review, we emphasize that glycine exerts its anti-inflammatory effects throughout the modulation of the expression of nuclear factor kappa B (NF-κB) in many cells. Although glycine is a non-essential amino acid, we highlight how dietary glycine supplementation is important in avoiding the development of chronic inflammation.

Glycinergic Signaling in Macrophages and Its Application in Macrophage-Associated Diseases

Accumulating evidences support that amino acids direct the fate decision of immune cells. Glycine is a simple structural amino acid acting as an inhibitory neurotransmitter. Besides, glycine receptors as well as glycine transporters are found in macrophages, indicating that glycine alters the functions of macrophages besides as an inhibitory neurotransmitter. Mechanistically, glycine shapes macrophage polarization via cellular signaling pathways (e.g., NF-κB, NRF2, and Akt) and microRNAs. Moreover, glycine has beneficial effects in preventing and/or treating macrophage-associated diseases such as colitis, NAFLD and ischemia-reperfusion injury. Collectively, this review highlights the conceivable role of glycinergic signaling for macrophage polarization and indicates the potential application of glycine supplementation as an adjuvant therapy in macrophage-associated diseases.

Metabolomic-based clinical studies and murine models for acute pancreatitis disease: A review

Acute pancreatitis (AP) is one of the most common gastroenterological disorders requiring hospitalization and is associated with substantial morbidity and mortality. Metabolomics nowadays not only help us to understand cellular metabolism to a degree that was not previously obtainable, but also to reveal the importance of the metabolites in physiological control, disease onset and development. An in-depth understanding of metabolic phenotyping would be therefore crucial for accurate diagnosis, prognosis and precise treatment of AP. In this review, we summarized and addressed the metabolomics design and workflow in AP studies, as well as the results and analysis of the in-depth of research. Based on the metabolic profiling work in both clinical populations and experimental AP models, we described the metabolites with potential utility as biomarkers and the correlation between the altered metabolites and AP status. Moreover, the disturbed metabolic pathways correlated with biological function were discussed in the end. A practical understanding of current and emerging metabolomic approaches applicable to AP and use of the metabolite information presented will aid in designing robust metabolomics and biological experiments that result in identification of unique biomarkers and mechanisms, and ultimately enhanced clinical decision-making.

Oral exposure to the free amino acid glycine inhibits the acute allergic response in a model of cow's milk allergy in mice

The conditionally essential amino acid glycine functions as inhibitory neurotransmitter in the mammalian central nervous system. Moreover, it has been shown to act as an anti-inflammatory compound in animal models of ischemic perfusion, post-operative inflammation, periodontal disease, arthritis and obesity. Glycine acts by binding to a glycine-gated chloride channel, which has been demonstrated on neurons and immune cells, including macrophages, polymorphonuclear neutrophils and lymphocytes. The present study aims to evaluate the effect of glycine on allergy development in a cow's milk allergy model. To this end, C3H/HeOuJ female mice were supplemented with glycine by oral gavage (50 or 100 mg/mouse) 4 hours prior to sensitization with cow's milk whey protein, using cholera toxin as adjuvant. Acute allergic skin responses and anaphylaxis were assessed after intradermal allergen challenge in the ears. Mouse mast cell protease-1 (mMCP-1) and whey specific IgE levels were detected in blood collected 30 minutes after an oral allergen challenge. Jejunum was dissected and evaluated for the presence of mMCP-1-positive cells by immunohistochemistry. Intake of glycine significantly inhibited allergy development in a concentration dependent manner as indicated by a reduction in; acute allergic skin response, anaphylaxis, serum mMCP-1 and serum levels of whey specific IgE. In addition, in-vitro experiments using rat basophilic leukemia cells (RBL), showed that free glycine inhibited cytokine release but not cellular degranulation. These findings support the hypothesis that the onset of cow's milk allergy is prevented by the oral intake of the amino acid glycine. An adequate intake of glycine might be important in the improvement of tolerance against whey allergy or protection against (whey-induced) allergy development.

Urinary metabolomics analysis reveals the effect of volatile oil from Angelica sinensis on LPS-induced inflammation rats

Lipopolysaccharide (LPS)-induced inflammation occurs commonly and volatile oil from Angelica sinensis (VOAS) can be used as an anti-inflammatory agent. The molecular mechanisms that allow the anti-inflammatory factors to be expressed are still unknown. In this paper, we applied gas chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography-time-of-flight mass spectrometry (LC-Q/TOF-MS) based on a metabolomics platform coupled with a network approach to analyze urine samples in three groups of rats: one with LPS-induced inflammation (MI); one with intervention with VOAS; and normal controls (NC). Our study found definite metabolic footprints of inflammation and showed that all three groups of rats, MI, intervention with VOAS and NC have distinct metabolic profiles in urine. The concentrations of 48 metabolites differed significantly among the three groups. The metabolites in urine were screened by the GC-MS and LC-Q/TOF-MS methods. The significantly changed metabolites (p < 0.05, variable importance in projection > 1.5) between MI, NC and VOAS were included in the metabolic networks. Finally, hub metabolites were screened, including glycine, arachidonic acid, l-glutamate, pyruvate and succinate, which have high values of degree (k). the Results suggest that disorders of glycine, arachidonic acid, l-glutamate, pyruvate and succinate metabolism might play an important part in the predisposition and development of LPS-induced inflammation. By applying metabolomics with network methods, the mechanisms of diseases are clearly elucidated.

Effects of a preconditioning oral nutritional supplement on pig livers after warm ischemia

Background. Several approaches have been proposed to pharmacologically ameliorate hepatic ischemia/reperfusion injury (IRI). This study was designed to evaluate the effects of a preconditioning oral nutritional supplement (pONS) containing glutamine, antioxidants, and green tea extract on hepatic warm IRI in pigs. Methods. pONS (70 g per serving, Fresenius Kabi, Germany) was dissolved in 250 mL tap water and given to pigs 24, 12, and 2 hrs before warm ischemia of the liver. A fourth dose was given 3 hrs after reperfusion. Controls were given the same amount of cellulose with the same volume of water. Two hours after the third dose of pONS, both the portal vein and the hepatic artery were clamped for 40 min. 0.5, 3, 6, and 8 hrs after reperfusion, heart rate (HR), mean arterial pressure (MAP), central venous pressure (CVP), portal venous flow (PVF), hepatic arterial flow (HAF), bile flow, and transaminases were measured. Liver tissue was taken 8 hrs after reperfusion for histology and immunohistochemistry. Results. HR, MAP, CVP, HAF, and PVF were comparable between the two groups. pONS significantly increased bile flow 8 hrs after reperfusion. ALT and AST were significantly lower after pONS. Histology showed significantly more severe necrosis and neutrophil infiltration in controls. pONS significantly decreased the index of immunohistochemical expression for TNF-α, MPO, and cleaved caspase-3 (P < 0.001). Conclusion. Administration of pONS before and after tissue damage protects the liver from warm IRI via mechanisms including decreasing oxidative stress, lipid peroxidation, apoptosis, and necrosis.