Taurocholate Research Articles

Plasma metabolomics signatures of developmental dysplasia of the hip in Tibet plateau

BackgroundDevelopmental dysplasia of the hip (DDH) is a common childhood health complaint, whose etiology is multifactorial. The incidence of DDH is variable and higher in Tibet plateau. Here, we collected plasma samples and studied the metabolomics signatures of DDH.MethodsFifty babies were enrolled: 25 with DDH and 25 age-matched non-DDH healthy controls (HC group). We collected plasma samples, laboratory parameters and conducted untargeted metabolomics profiling.ResultsThere are many differential metabolites among patients with DDH, including 4-β-hydroxymethyl-4-α-methyl-5-α-cholest-7-en-3-beta-ol, β-cryptoxanthin, α-tocopherol, taurocholic acid, glycocholic acid, 2-(3,4-dihydroxybenzoyloxy)-4,6-dihydroxybenzoate, arabinosylhypoxanthine, leucyl-hydroxyproline, hypoxanthine. The main differential metabolic pathways focused on primary bile acid biosynthesis, arginine and proline metabolism, phenylalanine metabolism, histidine metabolism, purine metabolism.ConclusionsTo our knowledge, this is the first report of metabolomics profile in babies with DHH. By combining the α-tocopherol and taurocholic acid, we could achieve the differential diagnosis of DDH.

HSP70 protects against acute pancreatitis-elicited intestinal barrier damage in rats

Acute pancreatitis (AP) is a frequent but severe abdominal emergency in general surgery with intestinal barrier dysfunction. Heat shock protein 70 (HSP70) is a ubiquitous molecular chaperone that has been proposed to exert favorable effects on AP. Nonetheless, the detailed impacts of HSP70 on the intestinal barrier function in AP are unknown, which will be investigated here. After the injection of sodium taurocholate into the biliopancreatic duct, the rat models of AP were established. After modeling, HSP70 expression was up-regulated through lentivirus infection. Western blot was used to detect HSP70 expression. H&E staining was used to examine the histological changes in the pancreatic and intestinal tissues. The levels of pancreatic biochemical markers and oxidative stress markers were detected using corresponding assay kits. ELISA was used to detect the levels of inflammatory cytokines and gastrointestinal function indicators. Immunofluorescence staining and Western blot were used to detect the expression of tight junction proteins. DCFH-DA probe and MitoSOX Red probe were used to detect total reactive oxygen species (ROS) and mitochondrial ROS (mtROS), respectively. TUNEL assay and Western blot were used to detect apoptosis. During the model construction, severe pancreatic and abnormal intestinal tissue abnormalities were observed, inflammatory response was activated and the intestinal barrier was disrupted. HSP70 expression was down-regulated in the intestinal tissues AP rat models. HSP70 ameliorated the morphological damage of pancreatic and intestinal tissues of AP rats. In addition, HSP70 significantly reduced intestinal barrier damage, inflammatory response, oxidative stress and apoptosis in the intestinal tissues of AP rat models. Collectively, HSP70 might attenuate AP through exerting anti-inflammatory, anti-oxidant, anti-apoptotic effects and inhibiting intestinal barrier disruption.

Glycyrrhizin Ameliorates Cardiac Injury in Rats with Severe Acute Pancreatitis by Inhibiting Ferroptosis via the Keap1/Nrf2/HO-1 Pathway.

Severe acute pancreatitis (SAP) is a potential fatal gastrointestinal disease that is usually complicated by myocardial injury and dysfunction. Due to the lack of understanding of the mechanism of SAP-associated cardiac injury (SACI), there is still no complete treatment. To explore the alleviative effect and anti-ferroptosis mechanism against SACI of glycyrrhizin (GL), an inhibitor of oxidative stress. The SAP model was established by perfusing 5% sodium taurocholate into biliopancreatic duct in rats. H&E staining and serum assays were used to assess the injury changes of pancreas and heart. Echocardiography was used to evaluate the cardiac function. Transmission electron microscopy (TEM) and oxidative stress assays were used to investigate the ferroptosis-related morphological and biochemical changes. Western blot and immunofluorescence were performed to analyzed the expression of ferroptosis-related proteins. Significant myocardial impairment was found in SAP rats according to increased histopathological scores, serum creatine kinase-MB (CK-MB) and cardiac troponin-I (cTnI) levels, and a decreased fractional shortening and ejection fraction. The decreased mitochondrial cristae and significant expression changes of ferroptosis-related proteins confirmed the presence of ferroptosis in SACI. GL treatment attenuated above-mentioned cardiac tissues damage by inhibiting ferroptosis via restoring the expression of Nrf2 and HO-1 in vivo and in vitro. Treating with ML385 (a Nrf2 inhibitor) or transfecting with siRNA-Nrf2 reversed the protective effect of GL. Our findings demonstrate the involvement of ferroptosis in SACI and suggest a potential role for GL in the treatment of SACI by supressing ferroptosis via Keap1/Nrf2/HO-1 pathway.

Unveiling the oral-gut connection: chronic apical periodontitis accelerates atherosclerosis via gut microbiota dysbiosis and altered metabolites in apoE−/− Mice on a high-fat diet

The aim of this study was to explore the impact of chronic apical periodontitis (CAP) on atherosclerosis in apoE−/− mice fed high-fat diet (HFD). This investigation focused on the gut microbiota, metabolites, and intestinal barrier function to uncover potential links between oral health and cardiovascular disease (CVD). In this study, CAP was shown to exacerbate atherosclerosis in HFD-fed apoE−/− mice, as evidenced by the increase in plaque size and volume in the aortic walls observed via Oil Red O staining. 16S rRNA sequencing revealed significant alterations in the gut microbiota, with harmful bacterial species thriving while beneficial species declining. Metabolomic profiling indicated disruptions in lipid metabolism and primary bile acid synthesis, leading to elevated levels of taurochenodeoxycholic acid (TCDCA), taurocholic acid (TCA), and tauroursodeoxycholic acid (TDCA). These metabolic shifts may contribute to atherosclerosis development. Furthermore, impaired intestinal barrier function, characterized by reduced mucin expression and disrupted tight junction proteins, was observed. The increased intestinal permeability observed was positively correlated with the severity of atherosclerotic lesions, highlighting the importance of the intestinal barrier in cardiovascular health. In conclusion, this research underscores the intricate interplay among oral health, gut microbiota composition, metabolite profiles, and CVD incidence. These findings emphasize the importance of maintaining good oral hygiene as a potential preventive measure against cardiovascular issues, as well as the need for further investigations into the intricate mechanisms linking oral health, gut microbiota, and metabolic pathways in CVD development.

Puerarin Modulates Hepatic Farnesoid X Receptor and Gut Microbiota in High-Fat Diet-Induced Obese Mice.

Obesity is associated with alterations in lipid metabolism and gut microbiota dysbiosis. This study investigated the effects of puerarin, a bioactive isoflavone, on lipid metabolism disorders and gut microbiota in high-fat diet (HFD)-induced obese mice. Supplementation with puerarin reduced plasma alanine aminotransferase, liver triglyceride, liver free fatty acid (FFA), and improved gut microbiota dysbiosis in obese mice. Puerarin's beneficial metabolic effects were attenuated when farnesoid X receptor (FXR) was antagonized, suggesting FXR-mediated mechanisms. In hepatocytes, puerarin ameliorated high FFA-induced sterol regulatory element-binding protein (SREBP) 1 signaling, inflammation, and mitochondrial dysfunction in an FXR-dependent manner. In obese mice, puerarin reduced liver damage, regulated hepatic lipogenesis, decreased inflammation, improved mitochondrial function, and modulated mitophagy and ubiquitin-proteasome pathways, but was less effective in FXR knockout mice. Puerarin upregulated hepatic expression of FXR, bile salt export pump (BSEP), and downregulated cytochrome P450 7A1 (CYP7A1) and sodium taurocholate transporter (NTCP), indicating modulation of bile acid synthesis and transport. Puerarin also restored gut microbial diversity, the Firmicutes/Bacteroidetes ratio, and the abundance of Clostridium celatum and Akkermansia muciniphila. This study demonstrates that puerarin effectively ameliorates metabolic disturbances and gut microbiota dysbiosis in obese mice, predominantly through FXR-dependent pathways. These findings underscore puerarin's potential as a therapeutic agent for managing obesity and enhancing gut health, highlighting its dual role in improving metabolic functions and modulating microbial communities.

Turicibacter faecis sp. nov., isolated from faeces of heart failure mouse model.

Strain TC023T, a Gram-positive, long, rod-shaped, spore-forming anaerobe, was isolated from the faeces of a heart failure mouse model. The strain formed greyish-white coloured colonies with a convex elevation on brain-heart infusion medium supplemented with 0.1 % sodium taurocholate, incubated at 37 °C for 2 days. Taxonomic analysis based on the 16S rRNA gene sequence showed that TC023T belonged to the genus Turicibacter, and was closely related to Turicibacter bilis MMM721T (97.6 %) and Turicibacter sanguinis MOL361T (97.4 %). The whole genome of the strain has a G+C content of 37.3 mol%. The average nucleotide identity and genome-to-genome distance between TC023T and Turicibacter bilis MMM721T were 77.6 % and 24.3 %, respectively, and those with Turicibacter sanguinis MOL361T were 75.4 % and 24.3 %, respectively. These genotypic, phenotypic, and biochemical analyses indicated that the isolate represents a novel species in the genus Turicibacter, and the name Turicibacter faecis sp. nov. is proposed. The type strain is TC023T (RIMD 2002001T=TSD 372T).

Bile acid-microbiota crosstalk in hepatitis B virus infection.

Hepatitis B virus (HBV) is a hepatotropic non-cytopathic virus characterized by liver-specific gene expression. HBV infection highjacks bile acid metabolism, notably impairing bile acid uptake via sodium taurocholate cotransporting polypeptide (NTCP), which is a functional receptor for HBV entry. Concurrently, HBV infection induces changes in bile acid synthesis and the size of the bile acid pool. Conversely, bile acid facilitates HBV replication and expression through the signaling molecule farnesoid X receptor (FXR), a nuclear receptor activated by bile acid. However, in HepaRG cells and primary hepatocytes, FXR agonists suppress HBV RNA expression and the synthesis and secretion of DNA. In the gut, the size and composition of the bile acid pool significantly influence the gut microbiota. In turn, the gut microbiota impacts bile acid metabolism and innate immunity, potentially promoting HBV clearance. Thus, the bile acid-gut microbiota axis represents a complex and evolving relationship in the context of HBV infection. This review explores the interplay between bile acid and gut microbiota in HBV infection and discusses the development of HBV entry inhibitors targeting NTCP.

A simple, rapid, and green method for determination of three cholic acids in bio-transformed Jindanfen by HPLC-MS

AbstractA simple, rapid, and green high-performance liquid chromatography-mass spectrometry (HPLC-MS) method was developed for determination of tauroursodeoxycholic acid (TUDCA), taurocholic acid (TCA), and taurochenodeoxycholic acid (TCDCA) in bio-transformed Jindanfen (BTJDF), which is obtained from chicken bile through a bioconversion process. The sample was prepared using water. The HPLC separation was operated on a poroshell 120 EC-C18 column with a 2.0 min gradient elution procedure. Detection was performed on a single quadrupole mass spectrometer in negative mode with selected ion monitoring mode (SIM). This developed HPLC-MS method presented good linearity (r > 0.997) and sensitivity (limit of quantification, 30.0–80.0 pg) for three analytes. The relative standard deviations (RSDs) for precision, repeatability, and stability were all below 3.00%. The matrix effects and average recoveries of three analytes were 91.2–97.9% (RSDs < 1.50%) and 95.4–103% (RSDs < 3.00%), respectively. The average contents of TUDCA, TCA, and TCDCA in ten batches of samples were 33.8, 13.2, and 20.5%, respectively. Finally, the greenness of the developed method was validated by Analytical Eco-Scale and Complex-GAPI. The developed method was proved to be an eco-friendly, effective, and reliable approach for assaying the three cholic acids in BTJDF, which is help to improve the quality evaluation level of the BTJDF industry.

Algal Oil Mitigates Sodium Taurocholate-Induced Pancreatitis by Alleviating Calcium Overload, Oxidative Stress, and NF-κB Activation in Pancreatic Acinar Cells.

Acute pancreatitis (AP) is characterized by elevated intracellular Ca2+ concentrations, mitochondrial dysfunction, and oxidative stress in pancreatic acinar cells. Algal oil (AO) has demonstrated antioxidant and anti-inflammatory properties. This study aims to explore the effects of algal oil on the microenvironment of AP. Rat pancreatic acinar AR42J cells were pretreated with AO containing 0, 50, 100, or 150 μM of docosahexaenoic acid (DHA) 2 h prior to AP induction using sodium taurocholate (STC). After 1 h of STC treatment, AR42J cells exhibited a significant increase in intracellular Ca2+ concentration and the production of amylase, lipase, reactive oxygen species, and pro-inflammatory mediators, including tumor necrosis factor-α and interleukin-6. These STC-induced increases were markedly reduced in cells pretreated with AO. In comparison to cells without AO, those treated with a high dose of AO before STC exposure demonstrated a significant increase in mitochondrial membrane potential and a decrease in lipid peroxidation. Furthermore, STC-activated nuclear factor kappa-B (NF-κB) was attenuated in AO-pretreated cells, as evidenced by a significant decrease in activated NF-κB. In conclusion, AO may prevent damage to pancreatic acinar cells by alleviating intracellular Ca2+ overload, mitigating mitochondrial dysfunction, reducing oxidative stress, and attenuating NF-κB-targeted inflammation.

Detection and analysis of serum bile acid profile in patients with colonic polyps.

Analyzing the variations in serum bile acid (BA) profile can provide a certain biological basis for early warning and prevention of various diseases. There is currently no comprehensive study on the relationship between the serum BA profile and colonic polyps. To study the serum BA profile detection results of patients with colonic polyps, and analyze the correlation between BA and colonic polyps. From January 1, 2022, to June 1, 2023, 204 patients with colonic polyps who were diagnosed and treated at Zhongda Hospital Southeast University were chosen as the study subjects, and 135 non-polyp people who underwent physical examination were chosen as the control group. Gathering all patients' clinical information, typical biochemical indicators, and BA profile. Compared with the control group, the serum levels of taurocholic acid, glycocholic acid, glycochenodeoxycholic acid, and taurochenodeoxycholic acid in the colonic polyp group were significantly higher than those in the control group, while the content of deoxycholic acid (DCA) was lower than that in the control group (P < 0.05). When colonic polyps were analyzed as subgroups, it was shown that there was a strong correlation between changes in the BA profile and polyp diameter, location, morphology, pathological kind, etc. The serum BA profile showed significant changes in patients with colonic polyps, with a significant increase in primary conjugated BA content and a decrease in secondary free bile acid DCA content. There is a certain correlation between primary free BA and pathological parameters of polyps.

Material basis and molecular mechanisms of Chaihuang Qingyi Huoxue Granule in the treatment of acute pancreatitis based on network pharmacology and molecular docking-based strategy.

This study aimed to analyze active compounds and signaling pathways of CH applying network pharmacology methods, and to additionally verify the molecular mechanism of CH in treating AP. Network pharmacology and molecular docking were firstly used to identify the active components of CH and its potential targets in the treatment of AP. The pancreaticobiliary duct was retrogradely injected with sodium taurocholate (3.5%) to create an acute pancreatitis (AP) model in rats. Histological examination, enzyme-linked immunosorbent assay, Western blot and TUNEL staining were used to determine the pathway and mechanism of action of CH in AP. Network pharmacological analysis identified 168 active compounds and 276 target proteins. In addition, there were 2060 targets associated with AP, and CH had 177 targets in common with AP. These shared targets, including STAT3, IL6, MYC, CDKN1A, AKT1, MAPK1, MAPK3, MAPK14, HSP90AA1, HIF1A, ESR1, TP53, FOS, and RELA, were recognized as core targets. Furthermore, we filtered out 5252 entries from the Gene Ontology(GO) and 186 signaling pathways from the Kyoto Encyclopedia of Genes and Genomes(KEGG). Enrichment and network analyses of protein-protein interactions predicted that CH significantly affected the PI3K/AKT signaling pathway, which played a critical role in programmed cell death. The core components and key targets showed strong binding activity based on molecular docking results. Subsequently, experimental validation demonstrated that CH inhibited the phosphorylation of PI3K and AKT in pancreatic tissues, promoted the apoptosis of pancreatic acinar cells, and further alleviated inflammation and histopathological damage to the pancreas in AP rats. Apoptosis of pancreatic acinar cells can be enhanced and the inflammatory response can be reduced through the modulation of the PI3K/AKT signaling pathway, resulting in the amelioration of pancreatic disease.

Vitamin B6 ameliorates acute pancreatitis by suppressing the caspase3 signaling pathway

BackgroundAcute pancreatitis (AP) is a prevalent exocrine inflammatory disorder of the pancreas characterized by pancreatic inflammation and injury to acinar cells. Vitamin B6 (VB6) is a vital nutrient that plays a significant role in preserving human health and has anti-inflammatory and anti-apoptotic effects.MethodsThis study aimed to explore the potential pancreatic protective effects of VB6 in mitigating pancreatic inflammation and apoptosis induced by taurocholate sodium (TLCS) in an AP model and to assess the underlying mechanism of action. AP was induced in Sprague‒Dawley (SD) rats through TLCS administration and lipopolysaccharide (LPS)-treated AR42J cells, followed by treatment with VB6.ResultsVarious parameters associated with AP were assessed in both plasma and pancreatic tissues. VB6 has been shown to ameliorate the severity of AP through various mechanisms. It effectively reduces the levels of serum amylase, lipase, and inflammatory factors, thereby mitigating histological injury to the pancreas. Moreover, VB6 inhibited pancreatic apoptosis by downregulating bax expression and up-regulating Bcl2 expression in TLCS-treated rats. Additionally, VB6 suppressed the expression of caspase3. The anti-inflammatory and anti-apoptotic effects of VB6 observed in LPS-treated AR42J cells are consistent with those observed in a rat model of AP.ConclusionsThese results suggest that VB6 exerts anti-inflammatory and anti-apoptotic effects through inhibition of the caspase3 signaling pathway and has a protective effect against AP.

The Predictive Value of Serum DAO, HDC, and MMP8 for the Gastrointestinal Injury in the Early Stage of Acute Pancreatitis in an Animal Model and a Clinical Study.

This study was aimed at exploring the use of the acute gastrointestinal injury (AGI) grade and sensitive biomarkers to investigate gastrointestinal (GI) injury in early stage of acute pancreatitis (AP). The AGI grade was used to evaluate intestinal function. Any GI injury above grade I (grades II-IV) was considered as severe. An AP rat model was created by retrograde injection of 4% sodium taurocholate. The pancreatic and intestinal histopathology scores were calculated by hematoxylin-eosin staining. Human and rat sera were assessed using ELISA. Tight junction (TJ) proteins were detected by Western blotting. In clinical study, the GI injury rate in mild acute pancreatitis (MAP), moderate severe acute pancreatitis (MSAP), and severe acute pancreatitis (SAP) groups was 26.8%, 78.4%, and 94.8%, respectively (P < 0.05). Diamine oxidase (DAO), histidine decarboxylase (HDC), and matrix metalloproteinase 8 (MMP8) serum levels were higher in AP patients than in healthy people (P < 0.05). Patients with GI injury had higher serum levels of DAO, HDC, and MMP8 than those without GI injury (P < 0.05). In animal experiments, the serum levels of DAO, HDC, and MMP8 were higher in the AP group than in normal and sham-operated (SO) groups (P < 0.05). The expressions of tricellulin, claudin-1, ZO-1, and occludin were significantly lower in the AP group than in normal and SO groups (P < 0.05). The serum levels of DAO, HDC, and MMP8 are novel biomarkers of GI injury in the early stage of AP; their elevation indicates the development of GI injury in AP. The intestinal TJ disruption may be a primary mechanism of GI injury and requires more in-depth research.

Arachidonic Acid Metabolism by Cyp4A Modulates Caveolae-Mediated Transcytotic LPS Transport in Mouse Jejunum

Arachidonic acid (AA) is metabolized not only by cyclooxygenases and lipoxygenases, but also by cytochrome P-450 4A family (Cyp4A) which is an androgen-driven enzyme that produces 20-hydroxyeicosatetraenoic acid (20-HETE). 20-HETE is an endogenous ligand for GPR75, which is highly associated with pathogenesis of obesity. Since metabolic endotoxemia is implicated in the induction of obesity, and the gut lumen is the primary source of endotoxin (lipopolysaccharides [LPS]), we hypothesized that AA metabolism may affect LPS entry through the small intestine. Furthermore, we have found that increased LPS transport during long-chain fatty acid (LCFA) absorption is abolished in caveolin-1 (Cav1) knockout (KO) jejunum, suggesting the involvement of caveolae-mediated endocytosis. We thus examined the effects of AA on LPS transport in murine jejunum. FITC-LPS (10 μg/ml) or FD4 (0.1 mM) was applied to the mucosal (m) bath of Ussing chambered muscle-stripped jejunum from male C57Bl6 wild type (WT) and Cav1 KO mice with measurement of the serosal (s) appearance of FITC-LPS or FD4 and transepithelial electrical resistance (TER). We examined the effects of the luminal application (10 mM) of oleic acid (OA), AA, eicosapentaenoic acid (EPA), or docosahexaenoic (DHA) with taurocholic acid (0.1 mM) on these parameters with or without the lipid raft inhibitor methyl-β-cyclodextrin (MβCD, 0.1 mM) or Cyp4A inhibitor HET0016 (10 μM). In another study, male and female WT and Cav1 KO mice were fed a standard diet (SD), or a diet enriched in saturated LCFA fat and sugar (LCD) for 6 wks. Luminal addition of OA and AA, but not EPA nor DHA, increased LPS m-to-s movement in WT jejunal mucosa. AA also increased FD4 m-to-s movement with no effect on TER. AA-induced LPS and FD4 movements were inhibited by luminal application of MβCD or HET0016, suggesting the involvement of lipid rafts and Cyp4A activity. Luminal AA had no effect on LPS and FD4 m-to-s movement in KO jejunum. LPS and FD4 m-to-s movement were also increased by luminal application of 20-HETE (0.3 and 1 μM). Immunostaining revealed that GPR75 was expressed on the plasma membranes of jejunal villous but not crypt cells. LCD induced obesity in WT, not in KO, with increased blood glucose levels, perigonadal fat weight, and liver weight, with changes more evident in male WT than in female WT. LCD increased LPS m-to-s movement in WT male jejunum, not in KO jejunum, which was inhibited by luminal addition of MβCD or HET0016. These results suggest that luminal AA increases 20-HETE production by Cyp4A, then activates Cav1-mediated endocytosis which in turn enhances LPS transport in the small intestine, possibly via GPR75 activation. The AA-Cyp4A-20-HETE-GPR75 system may be a new therapeutic target for metabolic endotoxemia associated with diet-induced obesity, especially in males. VA Merit Review and DoD grants. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Increased intestinal bile acid absorption contributes to age-related cognitive impairment

Cognitive impairment in the elderly is associated with alterations in bile acid (BA) metabolism. In this study, we observe elevated levels of serum conjugated primary bile acids (CPBAs) and ammonia in elderly individuals, mild cognitive impairment, Alzheimer's disease, and aging rodents, with a more pronounced change in females. These changes are correlated with increased expression of the ileal apical sodium-bile acid transporter (ASBT), hippocampal synapse loss, and elevated brain CPBA and ammonia levels in rodents. Invitro experiments confirm that a CPBA, taurocholic acid, and ammonia induced synaptic loss. Manipulating intestinal BA transport using ASBT activators or inhibitors demonstrates the impact on brain CPBA and ammonia levels as well as cognitive decline in rodents. Additionally, administration of an intestinal BA sequestrant, cholestyramine, alleviates cognitive impairment, normalizing CPBAs and ammonia in aging mice. These findings highlight the potential of targeting intestinal BA absorption as a therapeutic strategy for age-related cognitive impairment.

High Fat Diet-Induced Constitutive Caveolin-1 Activation in Mouse Jejunum Promotes LPS Transport with Consequent Metabolic Syndrome

Lipopolysaccharides (LPS) entry from the intestinal lumen to the circulation is associated with systemic inflammation. We have found that LPS is transcellularly transported from the gut lumen to the portal vein (PV) in the presence of luminal long-chain fatty acid (LCFA) via CD36- and lipid raft-mediated pathways. Furthermore, LCFA-induced LPS transport is abolished in caveolin-1 (Cav1) knockout (KO) jejunum, suggesting the involvement of caveolae-mediated endocytosis. Here, we examined the effects of diets of varying FA composition on the development of the metabolic syndrome (MetS) and on LPS transport in murine jejunum. Male and female C57Bl6 wild type (WT) and Cav1 KO mice were fed a standard high CHO, high protein, low fat diet (SD), or one of 3 high fat-high sugar diets (34% sucrose, 42% fat) that were enriched in saturated LCFA (LCD), medium-chain FA (MCD) and polyunsaturated FA (PUD) for 6 wks. FITC-LPS was added to the mucosal (m) bath of Ussing-chambered muscle-stripped jejunum. Serosal (s) appearance of FITC-LPS was measured with or without luminal addition of oleic acid (OA, 10 mM)/taurocholic acid (TCA, 0.1 mM). FD4 m-to-s permeability and transepithelial electrical resistance (TER) were also measured. PV LPS levels were measured by a limulus amœbocyte lysate test kit. LCD-induced MetS (increased body weight, blood glucose levels, perigonadal fat weight, and liver weight), predominantly in male, whereas MCD and PUD did not induce MetS in WT. Nevertheless, LCD failed to induce MetS in KO, confirming that Cav1 KO mice are resistant to diet-induced obesity. PV LPS levels were elevated only in male WT LCD with no change in KO. There was no FITC-LPS m-to-s movement in WT SD jejunum, whereas luminal addition of OA/TCA increased LPS m-to-s movement. Interestingly, FITC-LPS m-to-s movement was increased in jejunum from WT LCD with no further increase after OA/TCA challenge, suggesting that LCD constitutively upregulated LPS transport. FD4 permeability was significantly higher in WT LCD than in WT SD, but not in KO. MCD but no other diet somewhat increased TER, compared with WT SD or KO SD. Constitutive LPS transport in WT LCD jejunum was abolished by luminal addition of the lipid raft inhibitor methyl-β-cyclodextrin (0.1 mM), suggesting the involvement of transcytotic rather than paracellular transport mechanisms. No LPS transport was observed in KO SD and KO LCD jejunum, further suggesting that LCD-induced LPS transport is Cav1 dependent. These results suggest that LCD constitutively activates Cav1-mediated endocytotic LPS transport in the small intestine, resulting in metabolic endotoxemia and the MetS. Cav1-mediated LPS transport is a promising therapeutic target for diet-induced, LPS-associated MetS. VA Merit Review and DoD grants. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

The Enhanced Anti-anxiety Potentiality and Relevant Material Basis for the Extracts of Bile Processed Coptidis Rhizoma

Objective Bile-processed Coptidis Rhizoma (CR) exhibits stronger cold properties and central effect. However, the commonly used bile includes pig/cattle/sheep bile. It is currently unclear which kind of bile performs the best synergistic effect, and the enhanced efficacy is mainly contributed by what components. In this work, a comparative study on pig/cattle/sheep bile processed CR (pCR/cCR/sCR) was carried out. Materials and Methods Firstly, the anxiety model of sthenic heat type was established. Then, pharmacological research involving general state observation, biochemical examination (succinate dehydrogenase, glucokinase, corticosterone, adrenocor ticotropic hormore), pathological evaluation (liver and hippocampus tissue), and behavioral tests (elevated plus maze, open field test) was implemented. Finally, chemical assessment involving high-performance liquid chromatography (HPLC) fingerprints of pCR/cCR/sCR extracts and mass spectrograms of pig/cattle/sheep bile were performed in combination. Results cCR performed the most prominent enhancement in improving hyperactive energy metabolism in liver and abnormal hyperactivity of hypothalamic–pituitary–adrenal axis axis. As for chemical assessment, HPLC fingerprints of pCR/cCR/sCR extracts indicated that alkaloid components detected in cCR extracts were relatively low, mass spectrograms of pig/cattle/sheep bile suggested that bile acids in cattle bile were relatively abundant, and the contents of taurocholic acid, glycocholic acid, and glycodeoxycholic acid were particularly high. Conclusion Cattle bile could be specified as the processing excipient for bile-processed CR, and the high levels of taurocholic acid, glycocholic acid, and glycodeoxycholic acid mainly contributed to the enhanced efficacy of cCR.

Exposure to Microcystin-LR Promotes Colorectal Cancer Progression by Altering Gut Microbiota and Associated Metabolites in APCmin/+ Mice.

Microcystins (MCs), toxins generated by cyanobacteria, feature microcystin-LR (MC-LR) as one of the most prevalent and toxic variants in aquatic environments. MC-LR not only causes environmental problems but also presents a substantial risk to human health. This study aimed to investigate the impact of MC-LR on APCmin/+ mice, considered as an ideal animal model for intestinal tumors. We administered 40 µg/kg MC-LR to mice by gavage for 8 weeks, followed by histopathological examination, microbial diversity and metabolomics analysis. The mice exposed to MC-LR exhibited a significant promotion in colorectal cancer progression and impaired intestinal barrier function in the APCmin/+ mice compared with the control. Gut microbial dysbiosis was observed in the MC-LR-exposed mice, manifesting a notable alteration in the structure of the gut microbiota. This included the enrichment of Marvinbryantia, Gordonibacter and Family_XIII_AD3011_group and reductions in Faecalibaculum and Lachnoclostridium. Metabolomics analysis revealed increased bile acid (BA) metabolites in the intestinal contents of the mice exposed to MC-LR, particularly taurocholic acid (TCA), alpha-muricholic acid (α-MCA), 3-dehydrocholic acid (3-DHCA), 7-ketodeoxycholic acid (7-KDCA) and 12-ketodeoxycholic acid (12-KDCA). Moreover, we found that Marvinbryantia and Family_XIII_AD3011_group showed the strongest positive correlation with taurocholic acid (TCA) in the mice exposed to MC-LR. These findings provide new insights into the roles and mechanisms of MC-LR in susceptible populations, providing a basis for guiding values of MC-LR in drinking water.

Multiomics Analysis Reveals Leucine Deprivation Promotes Bile Acid Synthesis by Upregulating Hepatic CYP7A1 and Intestinal Turicibacter sanguinis in Mice

BackgroundLeucine, a branched-chain amino acid, participates in the regulation of lipid metabolism and the composition of the intestinal microbiota. However, the related mechanism remains unclear. ObjectivesHere, we aimed to reveal the potential mechanisms by which hepatic CYP7A1 (a rate-limiting enzyme for bile acid [BA] synthesis) and gut microbiota coregulate BA synthesis under leucine deprivation. MethodsTo this end, 8-wk-old C57BL/6J mice were fed with either regular diets or leucine-free diets for 1 wk. Then, we investigated whether secondary BAs were synthesized by Turicibacter sanguinis in 7-wk-old C57BL/6J germ-free mice gavaged with T. sanguinis for 2 wk by determining BA concentrations in the plasma, liver, and cecum contents using liquid chromatography-tandem mass spectrometry. ResultsThe results showed that leucine deprivation resulted in a significant increase in total BA concentration in the plasma and an increase in the liver, but no difference in total BA was observed in the cecum contents before and after leucine deprivation. Furthermore, leucine deprivation significantly altered BA profiles such as taurocholic acid and ω-muricholic acid in the plasma, liver, and cecum contents. CYP7A1 expression was significantly upregulated in the liver under leucine deprivation. Leucine deprivation also regulated the composition of the gut microbiota; specifically, it significantly upregulated the relative abundance of T. sanguinis, thus enhancing the conversion of primary BAs into secondary BAs by intestinal T. sanguinis in mice. ConclusionsOverall, leucine deprivation regulated BA profiles in enterohepatic circulation by upregulating hepatic CYP7A1 expression and increasing intestinal T. sanguinis abundance. Our findings reveal the contribution of gut microbiota to BA metabolism under dietary leucine deprivation.

A multi-omics approach to investigate characteristics of gut microbiota and metabolites in hypertension and diabetic nephropathy SPF rat models.

Imbalance in intestinal microbiota caused by microbial species and proportions or metabolites derived from microbes are associated with hypertension, as well as diabetic nephropathy. However, the involvement of the intestinal microbiota and metabolites in hypertension and diabetic nephropathy comorbidities (HDN) remains to be elucidated. We investigated the effects of intestinal microbiota on HDN in a rat model and determined the abundance of the intestinal microbiota using 16S rRNA sequencing. Changes in fecal and serum metabolites were analyzed using ultra-high-performance liquid chromatography-mass spectrometry. The results showed abundance of Proteobacteria and Verrucomicrobia was substantially higher, whereas that of Bacteroidetes was significant lower in the HDN group than in the sham group. Akkermansia, Bacteroides, Blautia, Turicibacter, Lactobacillus, Romboutsia, and Fusicatenibacter were the most abundant, and Prevotella, Lachnospiraceae_NK4A136_group, and Prevotella_9 were the least abundant in the HDN group. Further analysis with bile acid metabolites in serum showed that Blautia was negatively correlated with taurochenodeoxycholic acid, taurocholic acid, positively correlated with cholic acid and glycocholic acid in serum. These findings suggest that the gut microbiota and metabolites in feces and serum substantially differed between the HDN and sham groups. The F/B ratio was higher in the HDN group than in the sham group. Blautia is potentially associated with HDN that correlated with differentially expressed bile acid metabolites, which might regulate the pathogenesis of HDN via the microorganism-gut-metabolite axis.