5-aminosalicylic acid（5-ASA） is drug of choice for the treatment of ulcerative colitis（UC）. In this study, the efficacy of topical versus oral 5-ASA for the treatment of UC was examined as well as the action mecha...5-aminosalicylic acid（5-ASA） is drug of choice for the treatment of ulcerative colitis（UC）. In this study, the efficacy of topical versus oral 5-ASA for the treatment of UC was examined as well as the action mechanism of this medication. A flexible tube was inserted into the rat cecum to establish a topical administration model of 2,4,6-trinitrobenzene sulfonic acid（TNBS）-induced UC. A total of 60 rats were divided into sham operation group（receiving an enema of 0.9% saline solution instead of the TNBS solution via the tube）, model group, topical 5-ASA group, oral Etiasa group（a release agent of mesalazine used as positive control） and oral 5-ASA group（n=12 each）. Different treatments were administered 1 day after UC induction. The normal saline（2 mL） was instilled twice a day through the tube in the sham operation group and model group. 5-ASA was given via the tube in the topical 5-ASA group（7.5 g/L, twice per day, 100 mg/kg）, and rats in the oral Etiasa group and oral 5-ASA group intragastrically received Etiasa（7.5 g/L, twice per day, 100 mg/kg） and 5-ASA（7.5 g/L, twice per day, 100 mg/kg）, respectively. The body weight was recorded every day. After 7 days of treatment, blood samples were drawn from the heart to harvest the sera. Colonic tissues were separated and prepared for pathological and related molecular biological examinations. The concentrations of 5-ASA were detected at different time points in the colonic tissues, feces and sera in different groups by using the high pressure liquid chromatography（HPLC）. The results showed that the symptoms of acute UC, including bloody diarrhea and weight loss, were significantly improved in topical 5-ASA-treated rats. The colonic mucosal damage, both macroscopical and histological, was significantly relieved and the myeloperoxidase activity was markedly decreased in rats topically treated with 5-ASA compared with those treated with oral 5-ASA or Etiasa. The mRNA and protein expression of IL-1β, IL-6, and TNF-α was down-regulated in the colonic tissue of rats topically treated with 5-ASA, significantly lower than those from rats treated with oral 5-ASA or Etiasa. The concentrations of 5-ASA in the colonic tissue were significantly higher in the topical 5-ASA group than in the oral 5-ASA and oral Etiasa groups. It was concluded that the topical administration of 5-ASA can effectively increase the concentration of 5-ASA in the colonic tissue, decrease the expression of proinflammatory cytokines, alleviate the colonic pathological damage and improve the symptoms of TNBS-induced acute UC in rats.展开更多
Acute and chronic colitis affect a huge proportion of the population world-wide.The etiology of colitis cases can be manifold,and diet can significantly affect onset and outcome of colitis.While many forms of acute co...Acute and chronic colitis affect a huge proportion of the population world-wide.The etiology of colitis cases can be manifold,and diet can significantly affect onset and outcome of colitis.While many forms of acute colitis are easily treatable,chronic forms of colitis such as ulcerative colitis and Crohn’s disease(summarized as inflammatory bowel diseases)are multifactorial with poorly understood pathogenesis.Inflammatory bowel diseases are characterized by exacerbated immune responses causing epithelial dysfunction and bacterial translocation.There is no cure and therapies aim at reducing inflammation and restoring intestinal barrier function.Unfortunately,most drugs can have severe side effects.Changes in diet and inclusion of nutritional supplements have been extensively studied in cell culture and animal models,and some supplements have shown promising results in clinical studies.Most of these nutritional supplements including vitamins,fatty acids and phytochemicals reduce oxidative stress and inflammation and have shown beneficial effects during experimental colitis in rodents induced by dextran sulphate sodium or 2,4,6-trinitrobenzene sulfonic acid,which remain the gold standard in pre-clinical colitis research.Here,we summarize the mechanisms through which such nutritional supplements contribute to epithelial barrier stabilization.展开更多
AIM: To investigate the effect and mechanism of stimulation of the hypothalamic paraventricular nucleus with glutamate acid in rats with ulcerative colitis(UC).METHODS: The rats were anesthetized with 10% chloral hydr...AIM: To investigate the effect and mechanism of stimulation of the hypothalamic paraventricular nucleus with glutamate acid in rats with ulcerative colitis(UC).METHODS: The rats were anesthetized with 10% chloral hydrate via abdominal injection and treated with an equal volume of TNBS + 50% ethanol enema, injected into the upper section of the anus with the tail facing up. Colonic damage scores were calculated after injecting a certain dose of glutamic acid into the paraventricular nucleus(p VN), and the effect of the nucleus tractus solitarius(NTS) and vagus nerve in alleviating UC injury through chemical stimulation of the p VN was observed in rats. Expression changes of C-myc, Apaf-1, caspase-3, interleukin(IL)-6, and IL-17 during the protection against UC injury through chemical stimulation of the p VN in rats were detected by Western blot. Malondialdehyde(MDA) content and superoxide dismutase(SOD) activity in colon tissues of rats were measured by colorimetric methods. RESULTS: Chemical stimulation of the PVN significantly reduced UC in rats in a dose-dependent manner. The protective effects of the chemical stimulationof the p VN on rats with UC were eliminated after chemical damage to the p VN. After glutamate receptor antagonist kynurenic acid was injected into the p VN, the protective effects of the chemical stimulation of the p VN were eliminated in rats with UC. After AVpVl receptor antagonist([Deamino-penl, val4, D-Arg8]-vasopressin) was injected into NTS or bilateral chemical damage to NTS, the protective effect of the chemical stimulation of p VN on UC was also eliminated. After chemical stimulation of the p VN, SOD activity increased, MDA content decreased, C-myc protein expression significantly increased, caspase-3 and Apaf-1 protein expression significantly decreased, and IL-6 and IL-17 expression decreased in colon tissues in rats with UC. CONCLUSION: Chemical stimulation of the hypothalamic p VN provides a protective effect against UC injury in rats. Hypothalamic p VN, NTS and vagus nerve play key roles in this process.展开更多
AIMTo investigate the protective effect of a recombinant adeno-associated virus carrying thymosin β<sub>4</sub> (AAV-Tβ<sub>4</sub>) on murine colitis via intracolonic a...AIMTo investigate the protective effect of a recombinant adeno-associated virus carrying thymosin β<sub>4</sub> (AAV-Tβ<sub>4</sub>) on murine colitis via intracolonic administration.METHODSAAV-Tβ<sub>4</sub> was prepared and intracolonically used to mediate the secretory expression of Tβ<sub>4</sub> in mouse colons. Dextran sulfate sodium (DSS) was applied to induce the murine ulcerative colitis, and 2,4,6-trinitrobenzene sulfonic acid (TNBS) was used to establish a mouse colitis model resembling Crohn’s disease. The disease severity and colon injuries were observed and graded to reveal the effects of AAV-Tβ<sub>4</sub> on colitis. The activities of myeloperoxidase (MPO) and superoxide dismutase (SOD) and the content of malondialdehyde (MDA) were determined using biochemical assays. Colonic levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-10 were measured using ELISA, and mucosal epithelial cell apoptosis and proliferation were detected by TUNEL assay and immunochemistry, respectively.RESULTSRecombinant AAVs efficiently delivered LacZ and Tβ<sub>4</sub> into the colonic tissues of the mice, and AAV-Tβ<sub>4</sub> led to a strong expression of Tβ<sub>4</sub> in mouse colons. In both the DSS and TNBS colitis models, AAV-Tβ<sub>4</sub>-treated mice displayed distinctly attenuated colon injuries and reduced apoptosis rate of colonic mucosal epithelia. AAV-Tβ<sub>4</sub> significantly reduced inflammatory cell infiltrations and relieved oxidative stress in the inflamed colons of the mice, as evidenced by decreases in MPO activity and MDA content and increases in SOD activity. AAV-Tβ<sub>4</sub> also modulated colonic TNF-α, IL-1β and IL-10 levels and suppressed the compensatory proliferation of colonic epithelial cells in DSS- and TNBS-treated mice.CONCLUSIONTβ<sub>4</sub> exerts a protective effect on murine colitis, indicating that AAV-Tβ<sub>4</sub> could potentially be developed into a promising agent for the therapy of inflammatory bowel diseases.展开更多
AIM: To evaluate the in vitro immunomodulation capacity of various non-pathogenic yeast strains and to investigate the ability of some of these food grade yeasts to prevent experimental colitis in mice.METHODS: In vit...AIM: To evaluate the in vitro immunomodulation capacity of various non-pathogenic yeast strains and to investigate the ability of some of these food grade yeasts to prevent experimental colitis in mice.METHODS: In vitro immunomodulation was assessed by measuring cytokines [interleukin (IL)-12p70,IL-10,tumor necrosis factor and interferon γ] released by human peripheral blood mononuclear cells after 24 h stimulation with 6 live yeast strains (Saccharomyces ssp.) and with bacterial reference strains.A murine model of acute 2-4-6-trinitrobenzene sulfonic acid (TNBS)-colitis was next used to evaluate the distinct prophylactic protective capacities of three yeast strains compared with the performance of prednisolone treatment.RESULTS: The six yeast strains all showed similar non-discriminating anti-inflammatory potential when tested on immunocompetent cells in vitro .However,although they exhibited similar colonization patterns in vivo ,some yeast strains showed significant anti-inflammatory activities in the TNBS-induced colitis model,whereas others had weaker or no preventive effect at all,as evidenced by colitis markers (body-weight loss,macroscopic and histological scores,myeloperoxidase activities and blood inflammatory markers).CONCLUSION: A careful selection of strains is required among the biodiversity of yeasts for specific clinical studies,including applications in inflammatory bowel disease and other therapeutic uses.展开更多
基金supported by grants from the National Natural Science Foundation of China(No.81072431)the Innova-tion Foundation of Huazhong University of Science and Tech-nology(No.2010MS027)
文摘5-aminosalicylic acid（5-ASA） is drug of choice for the treatment of ulcerative colitis（UC）. In this study, the efficacy of topical versus oral 5-ASA for the treatment of UC was examined as well as the action mechanism of this medication. A flexible tube was inserted into the rat cecum to establish a topical administration model of 2,4,6-trinitrobenzene sulfonic acid（TNBS）-induced UC. A total of 60 rats were divided into sham operation group（receiving an enema of 0.9% saline solution instead of the TNBS solution via the tube）, model group, topical 5-ASA group, oral Etiasa group（a release agent of mesalazine used as positive control） and oral 5-ASA group（n=12 each）. Different treatments were administered 1 day after UC induction. The normal saline（2 mL） was instilled twice a day through the tube in the sham operation group and model group. 5-ASA was given via the tube in the topical 5-ASA group（7.5 g/L, twice per day, 100 mg/kg）, and rats in the oral Etiasa group and oral 5-ASA group intragastrically received Etiasa（7.5 g/L, twice per day, 100 mg/kg） and 5-ASA（7.5 g/L, twice per day, 100 mg/kg）, respectively. The body weight was recorded every day. After 7 days of treatment, blood samples were drawn from the heart to harvest the sera. Colonic tissues were separated and prepared for pathological and related molecular biological examinations. The concentrations of 5-ASA were detected at different time points in the colonic tissues, feces and sera in different groups by using the high pressure liquid chromatography（HPLC）. The results showed that the symptoms of acute UC, including bloody diarrhea and weight loss, were significantly improved in topical 5-ASA-treated rats. The colonic mucosal damage, both macroscopical and histological, was significantly relieved and the myeloperoxidase activity was markedly decreased in rats topically treated with 5-ASA compared with those treated with oral 5-ASA or Etiasa. The mRNA and protein expression of IL-1β, IL-6, and TNF-α was down-regulated in the colonic tissue of rats topically treated with 5-ASA, significantly lower than those from rats treated with oral 5-ASA or Etiasa. The concentrations of 5-ASA in the colonic tissue were significantly higher in the topical 5-ASA group than in the oral 5-ASA and oral Etiasa groups. It was concluded that the topical administration of 5-ASA can effectively increase the concentration of 5-ASA in the colonic tissue, decrease the expression of proinflammatory cytokines, alleviate the colonic pathological damage and improve the symptoms of TNBS-induced acute UC in rats.
基金funded by the fund SEP-Cinvestav (Project 108)by Conacyt (284292)the Royal Society (NAF/R1/180017)
文摘Acute and chronic colitis affect a huge proportion of the population world-wide.The etiology of colitis cases can be manifold,and diet can significantly affect onset and outcome of colitis.While many forms of acute colitis are easily treatable,chronic forms of colitis such as ulcerative colitis and Crohn’s disease(summarized as inflammatory bowel diseases)are multifactorial with poorly understood pathogenesis.Inflammatory bowel diseases are characterized by exacerbated immune responses causing epithelial dysfunction and bacterial translocation.There is no cure and therapies aim at reducing inflammation and restoring intestinal barrier function.Unfortunately,most drugs can have severe side effects.Changes in diet and inclusion of nutritional supplements have been extensively studied in cell culture and animal models,and some supplements have shown promising results in clinical studies.Most of these nutritional supplements including vitamins,fatty acids and phytochemicals reduce oxidative stress and inflammation and have shown beneficial effects during experimental colitis in rodents induced by dextran sulphate sodium or 2,4,6-trinitrobenzene sulfonic acid,which remain the gold standard in pre-clinical colitis research.Here,we summarize the mechanisms through which such nutritional supplements contribute to epithelial barrier stabilization.
文摘AIM: To investigate the effect and mechanism of stimulation of the hypothalamic paraventricular nucleus with glutamate acid in rats with ulcerative colitis(UC).METHODS: The rats were anesthetized with 10% chloral hydrate via abdominal injection and treated with an equal volume of TNBS + 50% ethanol enema, injected into the upper section of the anus with the tail facing up. Colonic damage scores were calculated after injecting a certain dose of glutamic acid into the paraventricular nucleus(p VN), and the effect of the nucleus tractus solitarius(NTS) and vagus nerve in alleviating UC injury through chemical stimulation of the p VN was observed in rats. Expression changes of C-myc, Apaf-1, caspase-3, interleukin(IL)-6, and IL-17 during the protection against UC injury through chemical stimulation of the p VN in rats were detected by Western blot. Malondialdehyde(MDA) content and superoxide dismutase(SOD) activity in colon tissues of rats were measured by colorimetric methods. RESULTS: Chemical stimulation of the PVN significantly reduced UC in rats in a dose-dependent manner. The protective effects of the chemical stimulationof the p VN on rats with UC were eliminated after chemical damage to the p VN. After glutamate receptor antagonist kynurenic acid was injected into the p VN, the protective effects of the chemical stimulation of the p VN were eliminated in rats with UC. After AVpVl receptor antagonist([Deamino-penl, val4, D-Arg8]-vasopressin) was injected into NTS or bilateral chemical damage to NTS, the protective effect of the chemical stimulation of p VN on UC was also eliminated. After chemical stimulation of the p VN, SOD activity increased, MDA content decreased, C-myc protein expression significantly increased, caspase-3 and Apaf-1 protein expression significantly decreased, and IL-6 and IL-17 expression decreased in colon tissues in rats with UC. CONCLUSION: Chemical stimulation of the hypothalamic p VN provides a protective effect against UC injury in rats. Hypothalamic p VN, NTS and vagus nerve play key roles in this process.
基金Supported by National Foundation of Natural Sciences,China,No.81300293
文摘AIMTo investigate the protective effect of a recombinant adeno-associated virus carrying thymosin β<sub>4</sub> (AAV-Tβ<sub>4</sub>) on murine colitis via intracolonic administration.METHODSAAV-Tβ<sub>4</sub> was prepared and intracolonically used to mediate the secretory expression of Tβ<sub>4</sub> in mouse colons. Dextran sulfate sodium (DSS) was applied to induce the murine ulcerative colitis, and 2,4,6-trinitrobenzene sulfonic acid (TNBS) was used to establish a mouse colitis model resembling Crohn’s disease. The disease severity and colon injuries were observed and graded to reveal the effects of AAV-Tβ<sub>4</sub> on colitis. The activities of myeloperoxidase (MPO) and superoxide dismutase (SOD) and the content of malondialdehyde (MDA) were determined using biochemical assays. Colonic levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-10 were measured using ELISA, and mucosal epithelial cell apoptosis and proliferation were detected by TUNEL assay and immunochemistry, respectively.RESULTSRecombinant AAVs efficiently delivered LacZ and Tβ<sub>4</sub> into the colonic tissues of the mice, and AAV-Tβ<sub>4</sub> led to a strong expression of Tβ<sub>4</sub> in mouse colons. In both the DSS and TNBS colitis models, AAV-Tβ<sub>4</sub>-treated mice displayed distinctly attenuated colon injuries and reduced apoptosis rate of colonic mucosal epithelia. AAV-Tβ<sub>4</sub> significantly reduced inflammatory cell infiltrations and relieved oxidative stress in the inflamed colons of the mice, as evidenced by decreases in MPO activity and MDA content and increases in SOD activity. AAV-Tβ<sub>4</sub> also modulated colonic TNF-α, IL-1β and IL-10 levels and suppressed the compensatory proliferation of colonic epithelial cells in DSS- and TNBS-treated mice.CONCLUSIONTβ<sub>4</sub> exerts a protective effect on murine colitis, indicating that AAV-Tβ<sub>4</sub> could potentially be developed into a promising agent for the therapy of inflammatory bowel diseases.
文摘AIM: To evaluate the in vitro immunomodulation capacity of various non-pathogenic yeast strains and to investigate the ability of some of these food grade yeasts to prevent experimental colitis in mice.METHODS: In vitro immunomodulation was assessed by measuring cytokines [interleukin (IL)-12p70,IL-10,tumor necrosis factor and interferon γ] released by human peripheral blood mononuclear cells after 24 h stimulation with 6 live yeast strains (Saccharomyces ssp.) and with bacterial reference strains.A murine model of acute 2-4-6-trinitrobenzene sulfonic acid (TNBS)-colitis was next used to evaluate the distinct prophylactic protective capacities of three yeast strains compared with the performance of prednisolone treatment.RESULTS: The six yeast strains all showed similar non-discriminating anti-inflammatory potential when tested on immunocompetent cells in vitro .However,although they exhibited similar colonization patterns in vivo ,some yeast strains showed significant anti-inflammatory activities in the TNBS-induced colitis model,whereas others had weaker or no preventive effect at all,as evidenced by colitis markers (body-weight loss,macroscopic and histological scores,myeloperoxidase activities and blood inflammatory markers).CONCLUSION: A careful selection of strains is required among the biodiversity of yeasts for specific clinical studies,including applications in inflammatory bowel disease and other therapeutic uses.
