Project description:Nonalcoholic fatty liver disease is the most common liver disease worldwide. Hepatic steatosis and oxidative stress are the main characteristics of NAFLD (nonalcoholic fatty liver disease), which also affect its prognosis. Bixin acts as novel Nrf2 (NF-E2 p45-related factor 2) activator with the cytoprotection against oxidative stress and inflammation; this study mainly focused on the mechanism of Nrf2 activation by bixin and explored its potential feasibilities in long-term high-fat diet- (HFD-) caused hepatic steatosis and inflammatory response in vitro and in vivo. Bixin was found to activate Nrf2 signals by the modification of critical Keap1 (Kelch-like ECH-associated protein 1) cystine and competitive interaction with Keap1 with upregulating P62 mRNA and protein expression. In human liver cells exposed to FFA (free fatty acid), bixin displayed a pronounced cytoprotective activity with upregulation of Nrf2-mediated gene expression, such as PPARα and its targets related with fatty acid oxidation. In HFD-fed mice, systemic administration of bixin attenuated lipid accumulation, decreased oxidant inflammatory damage in the liver, and reduced circulating lipid levels through Nrf2. Different from most of other established inducers, bixin activated Nrf2 signals through two different mechanisms with safe administration for protection of oxidant inflammatory damage and attenuation of lipid accumulation in the in vivo long-term HFD-fed mice. Bixin represents a prototype Nrf2 activator that displays cytoprotective activity upon system administration targeting hepatic steatosis and oxidant inflammation originating from long-term HFD-fed mice. And bixin-based Nrf2-directed systemic intervention may also provide therapeutic benefit in protecting other organs in the process of metabolic syndrome.
Project description:Cardiac remodelling refers to a series of changes in the size, shape, wall thickness and tissue structure of the ventricle because of myocardial injury or increased pressure load. Studies have shown that cardiac remodelling plays a significant role in the development of heart failure. Zingerone, a monomer component extracted from ginger, has been proven to possess various properties including antioxidant, anti-inflammatory, anticancer and antidiabetic properties. As oxidative stress and inflammation contribute to acute and chronic myocardial injury, we explored the role of zingerone in cardiac remodelling. Mice were subjected to aortic banding (AB) or sham surgery and then received intragastric administration of zingerone or saline for 25 days. In vitro, neonatal rat cardiomyocytes (NRCMs) were treated with zingerone (50 and 250 μmol/L) when challenged with phenylephrine (PE). We observed that zingerone effectively suppressed cardiac hypertrophy, fibrosis, oxidative stress and inflammation. Mechanistically, Zingerone enhanced the nuclear factor (erythroid-derived 2)-like 2 (Nrf2)/antioxidant response element (ARE) activation via increasing the phosphorylation of endothelial nitric oxide synthase (eNOS) and nitric oxide (NO) production. Additionally, we used Nrf2-knockout (KO) and eNOS-KO mice and found that Nrf2 or eNOS deficiency counteracts these cardioprotective effects of zingerone in vivo. Together, we concluded that zingerone may be a potent treatment for cardiac remodelling that suppresses oxidative stress via the eNOS/Nrf2 pathway.
Project description:Alcohol consumption and obesity are known risk factors of steatohepatitis. Here, we report that the deficiency of CRAMP (cathelicidin-related antimicrobial peptide-gene name: Camp) is protective against a high-fat diet (HFD) plus acute alcohol (HFDE)-induced liver injury. HFDE markedly induced liver injury and steatosis in WT mice, which were attenuated in Camp-/- mice. Neutrophil infiltration was lessened in the liver of Camp-/- mice. HFDE feeding dramatically increased epididymal white adipose tissue (eWAT) mass and induced adipocyte hypertrophy in WT mice, whereas these effects were attenuated by the deletion of Camp. Furthermore, Camp-/- mice had significantly increased eWAT lipolysis, evidenced by up-regulated expression of lipolytic enzymes, adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL). The depletion of Camp also increased uncoupling protein 1 (UCP1)-dependent thermogenesis in the brown adipose tissue (BAT) of mice. HFDE fed Camp-/- mice had elevated protein levels of fibroblast growth factor 21 (FGF21) in the eWAT, with an increased adiponectin production, which had been shown to alleviate hepatic fat deposition and inflammation. Collectively, we have demonstrated that Camp-/- mice are protected against HFD plus alcohol-induced liver injury and steatosis through FGF21/adiponectin regulation. Targeting CRAMP could be an effective approach for prevention/treatment of high-fat diet plus alcohol consumption-induced steatohepatitis.
Project description:Intestinal injury is the primary toxicity of radiotherapy for pelvic and abdominal tumors, and it is also one of the common acute complications of radiotherapy. At present, there are no effective drugs to prevent intestinal injury in the clinic. Zingerone is a natural product with radioprotective effects. In this study, a novel compound (thiazolidine hydrochloride, TZC01) was synthesized by structural modification of zingerone. The effects of TZC01 on preventing intestinal injury from radiation were further investigated in this study. C57BL/6N mice were exposed to a lethal dose of abdominal irradiation (ABI) with and without TZC01 treatments. The morphological changes of the intestine and various makers of intestinal crypt cells were investigated. Treatment with TZC01 improved the survival rate of mice exposed to 12 Gy ABI. Moreover, TZC01 protected the intestinal morphology of mice, decreased the apoptotic rate of intestinal crypt cells, maintained cell regeneration and promoted crypt cell proliferation and differentiation. This study suggests that TZC01 has preventive and therapeutic effects on radiation enteritis by promoting the proliferation and differentiation of crypt cells to protect the small intestine from the toxic effects of ionizing radiation. Furthermore, the study of TCZ01 lays a strong foundation for developing novel radioprotectors with multiple properties.
Project description:BackgroundIntestinal mucositis is a common side effect of chemotherapy and radiotherapy. Very few drugs can efficiently ameliorate it. Tertiary butylhydroquinone (TBHQ) is a widely used food preservative with known immunomodulatory activity. Whether it has an effect on intestinal mucositis remains unknown. In this study, we investigated the role and mechanism of action of TBHQ on 5-fluorouracil-induced (5-FU-induced) human intestinal epithelial cell (HIEC) injury and intestinal mucositis in mice.MethodsWe established a cell model of HIEC injury and a mouse model of intestinal mucositis via treatment with 5-FU. Cell death, Cell Counting Kit-8, and lactate dehydrogenase (LDH) release were assessed for the HIECs. Diarrhea, body weight, intestinal length, mucosal damage, and the levels of IL-6, TNF-α, IL-1β, glutathione, reactive oxygen species, and malondialdehyde were determined for the mice. Additionally, we performed immunohistochemical analysis, immunofluorescence, western blotting, quantitative real-time PCR, and ELISA to examine the effects of TBHQ. Finally, HIECs were transfected with an Nrf2 gene silencer to verify its role in ferroptosis. All data were analyzed using one-way analysis of variance or paired t-tests.ResultsTBHQ markedly decreased LDH release and cell death and improved the proliferative ability of 5-FU-treated HIECs. The TBHQ-treated mice showed reduced weight loss, a lower diarrhea score, and longer colons than the 5-FU-treated mice. The in vivo expressions of IL-1β, IL-6, and TNF-α were suppressed by TBHQ treatment. Ferroptosis was shown to be involved in 5-FU-induced intestinal mucositis, and TBHQ markedly hampered its activation. Mechanistically, TBHQ activated Nrf2 effectively and selective Nrf2 knockdown significantly reduced the anti-ferroptotic functions of TBHQ in 5-FU-treated HIECs.ConclusionsTBHQ attenuates ferroptosis in 5-FU-induced intestinal mucositis, making it a potential novel protective agent against intestinal mucositis.
Project description:Oxidative stress is implicated in a wide range of intestinal disorders and closely associated with their pathological processes. Resveratrol (RSV), a plant extract, plays a vital role in protecting various organs in vitro and in vivo. However, the benefits of RSV are controversial, and underlying mechanisms for its antioxidant effects on intestinal epithelial cells remain unclear. In this study, we evaluated the effects of RSV on oxidative stress induced by H2O2 in IPEC-J2 cells. We found that pretreatment with RSV significantly increased cell viability; increased expression levels of tight junction (TJ) proteins (claudin-1, occludin, and ZO-1); improved activities of superoxide dismutase-1 (SOD-1), catalase (CAT), and glutathione peroxidase (GSH-Px); and decreased intracellular reactive oxygen species (ROS) levels and apoptosis induced by H2O2 (P < 0.05). In addition, RSV upregulated Akt phosphorylation, Nrf2 phosphorylation, and expression levels of antioxidant genes HO-1, SOD-1, and CAT in a dose-dependent manner (P < 0.05) under oxidative stress. Knockdown of Nrf2 by short-hairpin RNA (shRNA) abrogated RSV-mediated protection against H2O2-induced apoptosis, RSV-induced increase of TJ protein levels, and antioxidant gene expression (SOD-1, CAT, and GSH-Px) (P < 0.05). Consistent with Nrf2 knockdown, the PI3K/Akt inhibitor LY294002 significantly suppressed RSV-induced Nrf2 phosphorylation and RSV-induced increase of TJ protein levels and antioxidant gene expression under H2O2 treatment (P < 0.05). Collectively, these results demonstrate that RSV can directly protect IPEC-J2 cells against oxidative stress through the PI3K/Akt-mediated Nrf2 signaling pathway, suggesting that RSV may be an effective feed additive against intestinal damage in livestock production.
Project description:Transcriptional coactivator PGC-1α and its splice variant NT-PGC-1α regulate metabolic adaptation by modulating many gene programs. Selective ablation of PGC-1α attenuates diet-induced obesity through enhancing fatty acid oxidation and thermogenesis by upregulation of NT-PGC-1α in brown adipose tissue (BAT). Recently, we have shown that selective ablation of NT-PGC-1α reduces fatty acid oxidation in BAT. Thus, the objective of this study was to test our hypothesis that NT-PGC-1α-/- mice would be more prone to diet-induced obesity. Male and female NT-PGC-1α+/+ (WT) and NT-PGC-1α-/- mice were fed a regular chow or 60% high-fat (HF) diet for 16 weeks. Contrary to our expectations, both male and female NT-PGC-1α-/- mice fed HFD were protected from diet-induced obesity, with more pronounced effects in females. This lean phenotype was primarily driven by reduced dietary fat intake. Intriguingly, HFD-fed female, but not male, NT-PGC-1α-/- mice further exhibited decreased feed efficiency, which was closely associated with increased fecal fat excretion and decreased uptake of fatty acids by the intestinal enterocytes and adipocytes with a concomitant decrease in fatty acid transporter gene expression. Collectively, our results highlight the role for NT-PGC-1α in regulating whole body lipid homeostasis under HFD conditions.
Project description:The aim of this study was to investigate whether oral administration of Lactobacillus brevis 23017 (LB) alone and in combination with ellagic acid inhibits ChTLR15/ChNLRP3/ChIL-1β by activating the Nrf2/HO-1 pathway to attenuate intestinal inflammatory injury. Two animal experiments were performed. In Experiment 1, chickens were allocated into 7 groups: PBS, and low, medium and high dosages of live and heat-killed LB, named L/LB(+), M/LB(+) and H/LB(+), and L/LB(-), M/LB(-) and H/LB(-), respectively. In Experiment 2, chickens were divided into 5 groups: PBS, challenge control, and low, medium and high dosages of ellagic acid combined with LB(+), named L/EA + L/LB(+), M/EA + M/LB(+) and H/EA + H/LB(+), respectively. Chickens were gavaged with LB with or without ellagic acid once a day. Then, the mRNA and protein levels of the components of the Nrf2/HO-1 pathway found in the caecal tissues were quantified. On Day 7 post-infection with E. tenella, the levels of the components of the ChTLR15/NLRP3/IL-1β pathway in the caeca were again quantified, and the anticoccidial effects were assessed. The results showed that the levels of the genes in the Nrf2/HO-1 pathway in the chickens in the LB(+) groups were higher than those in the LB(-) groups (p < 0.001); those in the H/LB(+) group were higher than those in the M/LB(+) and L/LB(+) groups (p < 0.001); and those in the H/EA + H/LB(+) group showed the highest expression levels compared with the other groups (p < 0.001). After challenge, the chickens in the H/LB(+) group displayed less inflammatory injury than those in the M/LB(+) and L/LB(+) groups (p < 0.05), and the chickens in the H/EA + H/LB(+) group showed stronger anti-inflammatory effects than the other groups (p < 0.05). Thus, these protective effects against infection were consistent with the above results. Overall, significant anti-inflammatory effects were observed in chickens orally gavaged with high dosages of live L. brevis 23017 and ellagic acid, which occurred by regulation of the ChTLR15/NLRP3/IL-1β pathway.
Project description:BackgroundIntestinal epithelial barrier dysfunction is intricately linked to the pathogenesis of ulcerative colitis (UC). Dietary interventions that bolster intestinal epithelial barrier function can effectively thwart UC onset. Our prior research revealed that p-Hydroxy benzaldehyde (HD), a phenolic compound from Nostoc commune (an edible cyanobacterium), markedly upregulated the expression of E-cadherin, a pivotal protein in intestinal mucosa, thereby mitigating mucosal damage in mice afflicted with dextran sulfate sodium (DSS)-induced colitis. Nevertheless, the precise molecular mechanisms underpinning HD's ameliorative effects on intestinal epithelial barrier dysfunction remain elusive.MethodsDextran sodium sulfate (DSS)-induced colitis mouse model was established, and the successful establishment of the model was determined by evaluating the changes in body weight, disease activity index (DAI), colonic histopathology, and white blood cell count. Transmission electron microscopy (TEM) observed the ultrastructural changes of intestinal villi. The levels of inflammatory factors ( IFN-γ IL-13 ) and intestinal permeability indicators (FITC-Dextran, DAO, ET, and D-LA ) were detected by Enzyme-linked immunosorbent assay (ELISA). Western blotting (WB) and immunohistochemistry (IHC) were used to detect the expression of intestinal barrier integrity-related factors such as tight junction protein TJs (ZO-1, occludin) and adhesion junction protein AJs (E-cadherin). Furthermore, WB, Pull-down assay, drug affinity reaction target stability (DARTS) assay, molecular docking and molecular dynamics (MD) simulation were used to determine the potential target and molecular mechanism of HD.ResultsHD intervention significantly alleviated the symptoms of colitis mice, inhibited the weight loss and colon shortening, reduced DAI score and colon pathological score, maintained the ultrastructure of intestinal villi in colon tissue, and significantly reduced the inflammatory factors IFN-γ, IL-13 and the number of white blood cells in colon tissue of colitis mice. HD could also reduce the levels of FITC-Dextran, DAO, ET, and D-LA and increase the expression of ZO-1, occludin, and E-cadherin in the colonic tissues of colitis mice, thereby maintaining the impaired intestinal barrier function caused by colitis. Mechanically, HD augmented the expression of hepatocyte nuclear factor 1β (HNF-1β) and DRA. Adeno-associated virus (AAV)-HNF-1β shRNA or Lentivirus-mediated HNF-1β knockdown effectively abolished HD-induced intestinal barrier protection, as well as the promotion of solute carrier family 26 member 3 (SLC26A3) expression levels. SLC26A3 siRNA effectively reversed the inhibition of intestinal permeability by HD. Pull-down assay, DARTS analysis, molecular docking, and MD results showed high binding strength, interaction efficiency and remarkable stability between HNF-1β and HD.ConclusionThis study elucidates HD's role in forestalling intestinal epithelial barrier disruption under colitis conditions. Mechanistic investigations revealed that HD fortifies TJs and AJs expression via the HNF-1β/SLC26A3 pathway, thus preserving the lower intestinal epithelial barrier's integrity in UC.
Project description:BackgroundA Western diet (WD) is associated with increased inflammation in the large intestine, which is often ascribed to the high dietary fat content. Intestinal inflammation in rodents can be induced by oral administration of dextran sodium sulfate (DSS). However, most studies investigating effects of WD and DSS have not used appropriate low-fat diets (LFDs) as control.ObjectivesTo compare the effects of a WD with those of an LFD on colon health in a DSS-induced low-grade colonic inflammation mouse model.MethodsSix-week-old male C57BL/6JRj mice were fed an LFD (fat = 10.3% energy, n = 24) or a WD (fat = 41.2% energy, n = 24) for 15 wk [Experiment 1 (Exp.1)]. Half the mice on each diet (n = 12) then received 1% DSS in water for 6 d with the remainder (n = 12 in each diet) administered water. Disease activity, proinflammatory genes, inflammatory biomarkers, and fecal microbiota (16S rRNA) were assessed (Exp.1). Follow-up experiments (Exp.2 and Exp.3) were performed to investigate whether fat source (milk or lard; Exp.2) affected outcomes and whether a shift from LFD to WD 1 d prior to 1% DSS exposure caused an immediate effect on DSS-induced inflammation (Exp.3).ResultsIn Exp.1, 1% DSS treatment significantly increased disease score in the LFD group compared with the WD group (2.7 compared with 0.8; P < 0.001). Higher concentrations of fecal lipocalin (11-fold; P < 0.001), proinflammatory gene expression (≤82-fold), and Proteobacteria were observed in LFD-fed mice compared with the WD group. The 2 fat sources in WDs (Exp.2) revealed the same low inflammation in WD+DSS mice compared with LFD+DSS mice. Finally, the switch from LFD to WD just before DSS exposure resulted in reduced colonic inflammation (Exp.3).ConclusionsHerein, WDs (with milk or lard) protected mice against DSS-induced colonic inflammation compared with LFD-fed mice. Whether fat intake induces protective mechanisms against DSS-mediated inflammation or inhibits establishment of the DSS-induced colitis model is unclear.