Paeonol reduces microbial metabolite α-hydroxyisobutyric acid to alleviate the ROS/TXNIP/NLRP3 pathway-mediated endothelial inflammation in atherosclerosis mice

Gut microbiota dysbiosis is an avenue for the promotion of atherosclerosis(AS)and this effect is mediated partly via the circulating microbial metabolites.More microbial metabolites related to AS vascular inflammation,and the mechanisms involved need to be clarified urgently.Paeonol(Pae)is an active compound isolated from Paeonia suffruticoas Andr.with anti-As inflammation effect.However,considering the low oral bioavailability of Pae,it is worth exploring the mechanism by which Pae reduces the harmful metabolites of the gut microbiota to alleviate AS.In this study,ApoE--mice were fed a high-fat diet(HFD)to establish an AS model.AS mice were administrated with Pae(200 or 400 mg:kg')by oral gavage and fecal microbiota transplantation(FMT)was conducted.16S rDNA sequencing was performed to investigate the composition of the gut microbiota,while metabolomics analysis was used to identify the metabolites in serum and cecal contents.The results indicated that Pae significantly improved AS by regulating gut microbiota composition and microbiota metabolic profile in AS mice.We also identified a-hydroxyisobutyric acid(HIBA)as a harmful microbial metabolite reduced by Pae.HIBA supplementation in drinking water promoted AS inflammation in AS mice.Furthermore,vascular endothelial cells(VECs)were cultured and stimulated by HIBA.We verified that HIBA stimulation increased intracellular ROS levels,thereby inducing VEC inflammation via the TXNIP/NLRP3 pathway.In sum,Pae reduces the production of the microbial metabolite HIBA,thus alleviating the ROS/TXNIP/NLRP3 pathway-mediated endothelial inflammation in AS.Our study innovatively confirms the mechanism by which Pae reduces the harmful metabolites of gut microbiota to alleviate AS and proposes HIBA as a potential biomarker for AS clinical judgment.

The role of endothelial biomarkers in predicting damp-heat syndrome in diabetic kidney disease

Objective:To explore the role of endothelial biomarkers in predicting damp-heat syndrome in diabetic kidney disease(DKD).Methods:A total of 183 patients with DKD were divided into 3 groups:the early DKD group,established DKD group,and advanced DKD group.All patients were classified according to traditional Chinese medicine(TCM)syndrome type,and clinical indexes were collected for statistical analysis.Results:A total of 183 DKD patients were included in this study.Fibroblast growth factor 23(FGF23),chitinase-3-like protein 1(CHI3L1),endocan,tumor necrosis factor receptor 1(TNFR1),secretory leukocyte protease inhibitor(SLPI),and vascular endothelial growth factor A(VEGF-A)were increased in advanced DKD.FGF23,CHI3L1,endocan,SLPI,and TNFR1 showed a negative correlation with estimated glomerular filtration rate(eGFR),while they had a positive correlation with 24 h urine protein.After adjusting for age,gender,diabetes duration,body mass index(BMI),hemoglobin,glucose,uric acid,24 h urine protein,cholesterol,triglyceride,low-density lipoprotein,and hemoglobin A1c(HbA1c),the multiple regression analysis showed that FGF23,endocan,TNFR1,and SLPI significantly correlated with eGFR.Conclusions:FGF23,endocan,TNFR1,and SLPI are elevated in advanced DKD compared with early stage,and they may take part in the pathogenesis and progression of DKD.Our study provides useful biomarkers for predicting the appearance of damp-heat syndrome,including FGF23,endocan,TNFR1,and SLPI.

Intestinal ischemic manifestations of SARS-CoV-2:Results from the ABDOCOVID multicentre study

BACKGROUND Intestinal ischemia has been described in case reports of patients with severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)disease(coronavirus disease 19,COVID-19).AIM To define the clinical and histological,characteristics,as well as the outcome of ischemic gastrointestinal manifestations of SARS-CoV-2 infection.METHODS A structured retrospective collection was promoted among three tertiary referral centres during the first wave of the pandemic in northern Italy.Clinical,radiological,endoscopic and histological data of patients hospitalized for COVID-19 between March 1st and May 30th were reviewed.The diagnosis was established by consecutive analysis of all abdominal computed tomography(CT)scans performed.RESULTS Among 2929 patients,21(0.7%)showed gastrointestinal ischemic manifestations either as presenting symptom or during hospitalization.Abdominal CT showed bowel distention in 6 patients while signs of colitis/enteritis in 12.Three patients presented thrombosis of main abdominal veins.Endoscopy,when feasible,confirmed the diagnosis(6 patients).Surgical resection was necessary in 4/21 patients.Histological tissue examination showed distinctive features of endothelial inflammation in the small bowel and colon.Median hospital stay was 9 d with a mortality rate of 39%.CONCLUSION Gastrointestinal ischemia represents a rare manifestation of COVID-19.A high index of suspicion should lead to investigate this complication by CT scan,in the attempt to reduce its high mortality rate.Histology shows atypical feature of ischemia with important endotheliitis,probably linked to thrombotic microangiopathies.

Expression of platelet-endothelial cell adhesion molecule-1 in human umbilical vein endothelial cells by exposure to advanced glycosylation end products and inflammatory mediators

Objective To determine whether advanced glycosylation end products modified bovine serum albumin (AGEs-BSA) affects endothelial cell lateral junction protein, platelet-endothelial cell adhesion molecule-1 (PECAM-1) in the presence or absence of inflammatory mediators.Methods Cultured human umbilical vein endothelial cells (HUVECs) were exposed to AGEs-BSA for 6, 12, 24, and 36 hours, and exposed to AGEs-BSA glycosylated with different concentrations of glucose, tumor necrosis factord-α (TNF-α), interferon (IFN-γ), TNF-α + IFN-y and AGEs-BSA + TNF-α for 24 hours, respectively. Expression of PECAM-1 mRNA was measured by semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) with β-actin as an internal standard, and sequencing of RT-PCR products was performed to confirm the specificity of amplification for PECAM-1 gene. The endothelial cell surface expression of PECAM-1 was determined by flow cytometry (FCM).Results There were no significant changes in the expression of PECAM-1 mRNA and protein when the cells were exposed to AGEs-BSA with different concentrations or periods ( P>0. 05). However, PECAM-1 expression was reduced in the cells treated with TNF-α, IFN-y, TNF-α + IFN-γ and AGEs-BSA + TNF-α. The level of PECAM-1 treated with AGEs-BSA + TNF-α was lower than that of TNF-α treated alone (P<0. 01).Conclusions AGEs-BSA had no effect on the expression of PECAM-1 mRNA and protein in cultured HUVEC. With the presence of inflammatory mediator TNF-α, AGEs-BSA decreased the level of PECAM-1, which might reduce the adhesion interaction between adjacent endothelial cells, enhance the permeability of endothelial cells, and might be implicated in the endothelial dysfunction and pathogenesis of atherosclerosis in patients with diabetes mellitus. The significance of this phenomenon in intracellular signal transduction remains to be determined.

Screening the anti-gout traditional herbs from TCM using an in vitro method

The aim of this work was to evaluate the ability of 33 herbal extracts in inhibiting the acute inflammation and xanthine oxidase （XOD） activity. The anti-inflammation effects of the herbal extracts were detected by an in vitro cell model, which was established by stimulating human umbilical vein endothelial cells （HUVEC） using sodium urate （MSU）. In this model, the intercellular adhesion molecule-1 （ICAM-1） and interleukin-1 beta （IL-1β） were expressed, and the anti-inflammation effects of herbal extracts were evaluated by detecting the content changes of ICAM-1 and IL-1β in cell lysates and cell culture supernates using an enzyme-linked immunosorbent assay （ELISA）. Moreover, an ultrahigh performance liquid chromatography and tandem mass spectrometry （UPLC-MS/MS） method was used for the detection of XOD activity and the screening of XOD inhibitors in this research. The amount of uric acid from each analyte was directly detected using the multiple reaction monitoring mode and the uric acid level could be reduced via the addition of an inhibitor. Results indicated that Salviae Miltiorrhizae Radix et Rhizome, Rhei Radix et Rhizoma, Polygoni Cuspidati Rhizoma et Radix, Selaginellae Herba, Paeoniae Radix Rubra, especially Ginkgo Folium seemed to be more effective in anti-inflammation and inhibiting XOD activity. The anti-inflammation and enzyme inhibitory activities of the herbal extracts may be correlated with their bioactive components. And the differences between the herbal extracts were correlated with the amount of flavonoid and anthraquinone components. In our study, we have investigated the potential anti-inflammation bioactivity of 33 herbal extracts in vitro, which could provide a reference for further in vivo research in the orevention and treatment of gout.