scholarly journals PepT1-Knockout Mice Harbor a Protective Metabolome Beneficial for Intestinal Wound Healing

2021 ◽  
Author(s):  
Junsik Sung ◽  
Lixin Wang ◽  
Dingpei Long ◽  
Chunhua Yang ◽  
Didier Merlin
Keyword(s):  
Mass Spectrometry ◽  
In Vitro Models ◽  
Peptide Transporter ◽  
Protective Effects ◽  
Liquid Chromatography Mass Spectrometry ◽  
Wild Type ◽  
Acute Colitis ◽  
Tuberonic Acid ◽  
Inflammatory Effect

Genetic knockout (KO) of peptide transporter-1 (PepT1) protein is known to provide resistance to acute colitis and colitis-associated cancer (CAC) in mouse models. However, it was unclear which molecule(s) or pathway(s) formed the basis for these protective effects. Recently, we demonstrated that the PepT1-/- microbiota is sufficient to protect against colitis and CAC. Given that PepT1 KO alters the gut microbiome and thereby changes the intestinal metabolites that are ultimately reflected in the feces, we investigated the fecal metabolites of our PepT1 KO mice. Using a liquid chromatography-mass spectrometry (LC-MS)-based untargeted-metabolomics technique, we found that the fecal metabolites were significantly different between the KO and normal wild-type (WT) mice. Among the altered fecal metabolites, tuberonic acid (TA) was seven-fold higher in KO mouse feces than in WT mouse feces. Accordingly, we studied whether the increased TA could direct an anti-inflammatory effect. Using in vitro models, we discovered that TA not only prevented lipopolysaccharide (LPS)-induced inflammation in macrophages but also improved the epithelial cell healing processes. Our results suggest that TA, and possibly other fecal metabolites, play a crucial role in the pathway(s) associated with the anti-colitis effects of PepT1 KO.

scholarly journals Placental 13C-DHA metabolism and relationship with maternal BMI, glycemia and birthweight

2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Oliver C. Watkins ◽  
Preben Selvam ◽  
Reshma Appukuttan Pillai ◽  
Victoria K. B. Cracknell-Hazra ◽  
Hannah E. J. Yong ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Lipid Metabolism ◽  
Metabolic Pathways ◽  
Liquid Chromatography Mass Spectrometry ◽  
Fasting Glycemia ◽  
Glucose Treatment ◽  
Maternal Bmi

Abstract Background Fetal docosahexaenoic acid (DHA) supply relies on preferential transplacental transfer, which is regulated by placental DHA lipid metabolism. Maternal hyperglycemia and obesity associate with higher birthweight and fetal DHA insufficiency but the role of placental DHA metabolism is unclear. Methods Explants from 17 term placenta were incubated with 13C-labeled DHA for 48 h, at 5 or 10 mmol/L glucose treatment, and the production of 17 individual newly synthesized 13C-DHA labeled lipids quantified by liquid chromatography mass spectrometry. Results Maternal BMI positively associated with 13C-DHA-labeled diacylglycerols, triacylglycerols, lysophospholipids, phosphatidylcholine and phosphatidylethanolamine plasmalogens, while maternal fasting glycemia positively associated with five 13C-DHA triacylglycerols. In turn, 13C-DHA-labeled phospholipids and triacylglycerols positively associated with birthweight centile. In-vitro glucose treatment increased most 13C-DHA-lipids, but decreased 13C-DHA phosphatidylethanolamine plasmalogens. However, with increasing maternal BMI, the magnitude of the glucose treatment induced increase in 13C-DHA phosphatidylcholine and 13C-DHA lysophospholipids was curtailed, with further decline in 13C-DHA phosphatidylethanolamine plasmalogens. Conversely, with increasing birthweight centile glucose treatment induced increases in 13C-DHA triacylglycerols were exaggerated, while glucose treatment induced decreases in 13C-DHA phosphatidylethanolamine plasmalogens were diminished. Conclusions Maternal BMI and glycemia increased the production of different placental DHA lipids implying impact on different metabolic pathways. Glucose-induced elevation in placental DHA metabolism is moderated with higher maternal BMI. In turn, findings of associations between many DHA lipids with birthweight suggest that BMI and glycemia promote fetal growth partly through changes in placental DHA metabolism.

scholarly journals COMPOSITION OF PURIFIED ANTHOCYANIN ISOLATED FROM TEAK AND IT’S IN VITRO ANTIOXIDANT ACTIVITY

2017 ◽  
Vol 9 (9) ◽  
pp. 258 ◽  
Author(s):  
Greeshma Murukan ◽  
Murugan K.
Keyword(s):  
Mass Spectrometry ◽  
Antioxidant Activity ◽  
Liquid Chromatography ◽  
In Vitro Culture ◽  
Oxygen Radical ◽  
Sulphonic Acid ◽  
Oxygen Radical Absorbance Capacity ◽  
Liquid Chromatography Mass Spectrometry ◽  
Chromatography Mass Spectrometry

Objective: The present study evaluates purification, characterization of anthocyanin from in vitro culture of teak and its antioxidant potential.Methods: Anthocyanin was extracted from in vitro culture, purified by using amber lite XAD column and fractionated by Liquid chromatography mass spectrometry (LC-MS/MS). Various antioxidant assays were carried such as 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH), 2,2'-azino-bis-3-ethyl-benzothiazoline-6-sulphonic acid (ABTS), Oxygen radical absorbance capacity (ORAC), Nitric oxide (NO) and Hydrogen peroxide (H2O2).Results: Liquid chromatography mass spectrometry (LC-MS/MS) revealed the major fraction as cyanidin 3-(2-xylosyl-rutinoside) with unknown peaks. The amount of anthocyanin was 15.23 mg/g monomeric anthocyanin. Further, the potential antioxidant capacity of the teak anthocyanin was comparable to common vegetables and fruits. Similarly, high correlations of anthocyanin with antioxidant activity, such as oxygen radical absorbance capacity (ORAC), 2,2'-azino-bis-3-ethyl-benzothiazoline-6-sulphonic acid (ABTS), and 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) (r = 0.95, 0.93, and 0.80) were found.Conclusion: The high anthocyanins content and potential antioxidant activity suggests that teak anthocyanin may be applied in the food industry as a good source of natural pigments

scholarly journals Adiponectin inhibits leptin signalling via multiple mechanisms to exert protective effects against hepatic fibrosis

2011 ◽  
Vol 440 (3) ◽  
pp. 385-395 ◽  
Author(s):  
Jeffrey A. Handy ◽  
Ping P. Fu ◽  
Pradeep Kumar ◽  
Jamie E. Mells ◽  
Shvetank Sharma ◽  
...  
Keyword(s):  
Hepatic Fibrosis ◽  
Leptin Receptor ◽  
Tyrosine Phosphatase ◽  
Janus Kinase ◽  
Protective Effects ◽  
Wild Type ◽  
Matrix Deposition ◽  
Matrix Metalloproteinase 1 ◽  
Expression And Activity

Adiponectin is protective against hepatic fibrosis, whereas leptin promotes fibrosis. In HSCs (hepatic stellate cells), leptin signals via a JAK2 (Janus kinase 2)/STAT3 (signal transducer and activator of transcription 3) pathway, producing effects that enhance ECM (extracellular matrix) deposition. SOCS-3 (suppressor of cytokine signalling-3) and PTP1B (protein tyrosine phosphatase 1B) are both negative regulators of JAK/STAT signalling, and recent studies have demonstrated a role for adiponectin in regulating SOCS-3 expression. In the present study we investigate mechanisms whereby adiponectin dampens leptin signalling and prevents excess ECM production. We treated culture-activated rat HSCs with recombinant adiponectin, leptin, both or neither, and also treated adiponectin knockout (Ad−/−) and wild-type mice with leptin and/or carbon tetrachloride (CCl4) or saline. We analyse JAK2 and Ob-Rb (long form of the leptin receptor) phosphorylation, and PTP1B expression and activity. We also explore potential mechanisms through which adiponectin regulates SOCS-3–Ob-Rb association. Adiponectin inhibits leptin-stimulated JAK2 activation and Ob-Rb phosphorylation in HSCs, whereas both were increased in Ad−/− mice. Adiponectin stimulates PTP1B expression and activity in vitro, whereas PTP1B expression was lower in Ad−/−mice than in wild-type mice. Adiponectin also promotes SOCS-3–Ob-R association and blocks leptin-stimulated formation of extracellular TIMP-1 (tissue inhibitor of metalloproteinases-1)–MMP-1 (matrix metalloproteinase-1) complexes in vitro. These results suggest two novel mechanisms whereby adiponectin inhibits hepatic fibrosis: (i) by promoting binding of SOCS-3 to Ob-Rb, and (ii) by stimulating PTP1B expression and activity, thus inhibiting JAK2/STAT3 signalling at multiple points.

scholarly journals Development of Resistance in Wild-Type and Hypermutable Pseudomonas aeruginosa Strains Exposed to Clinical Pharmacokinetic Profiles of Meropenem and Ceftazidime Simulated In Vitro

2007 ◽  
Vol 51 (10) ◽  
pp. 3642-3649 ◽  
Author(s):  
Beate Henrichfreise ◽  
Irith Wiegand ◽  
Ingeborg Luhmer-Becker ◽  
Bernd Wiedemann
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Parent Strain ◽  
Resistance Mechanisms ◽  
In Vitro Models ◽  
Wild Type ◽  
Resistance Development ◽  
Development Of Resistance ◽  
Pharmacokinetic Profiles ◽  
Mutant Prevention Concentration

ABSTRACT In this study we investigated the interplay of antibiotic pharmacokinetic profiles and the development of mutation-mediated resistance in wild-type and hypermutable Pseudomonas aeruginosa strains. We used in vitro models simulating profiles of the commonly used therapeutic drugs meropenem and ceftazidime, two agents with high levels of antipseudomonal activity said to have different potentials for stimulating resistance development. During ceftazidime treatment of the wild-type strain (PAO1), fully resistant mutants overproducing AmpC were selected rapidly and they completely replaced wild-type cells in the population. During treatment with meropenem, mutants of PAO1 were not selected as rapidly and showed only intermediate resistance due to the loss of OprD. These mutants also replaced the parent strain in the population. During the treatment of the mutator P. aeruginosa strain with meropenem, the slowly selected mutants did not accumulate several resistance mechanisms but only lost OprD and did not completely replace the parent strain in the population. Our results indicate that the commonly used dosing regimens for meropenem and ceftazidime cannot avoid the selection of mutants of wild-type and hypermutable P. aeruginosa strains. For the treatment outcome, including the prevention of resistance development, it would be beneficial for the antibiotic concentration to remain above the mutant prevention concentration for a longer period of time than it does in present regimens.

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