Effect of Xielitang on TLR4/NF-κB/HIF-1α Signaling Pathway in Mice with Ulcerative Colitis / 中国实验方剂学杂志

ObjectiveTo explore the protective effect of Xielitang on ulcerative colitis （UC） mice induced by dextran sodium sulfate （DSS） and its possible mechanism. MethodSixty C57BL/6 mice were randomly divided into normal group， model group， sulfasalazine group and and low-， medium-， and high-dose Xielitang groups. Free drinking DSS solution to build the chronic UC model mice. Except for normal group， other groups were given 1.5% DSS for 3 cycles of drinking （days 1-7， days 22-28 and days 43-49） and distilled water for the rest of the time （days 8-21， days 29-42 and days 50-63）. After the first cycle， corresponding drugs were given for 42 days. The changes of general condition， body weight and disease activity index （DAI） score of mice were daily recorded during the experiment. At the end of the treatment， serum and colon tissue samples were collected， colon length was measured， intestinal weight index and colonic mucosal injury （CMDI） score were calculated. The pathological status of colon tissue was observed by hematoxylin-eosin （HE） staining. The levels of interleukin-6 （IL-6）， interleukin-10 （IL-10） and tumour necrosis factor-α （TNF-α） were measured by enzyme-linked immunosorbent assay （ELISA）. The gene and protein expressions of Toll like receptor 4 （TLR4）， nuclear transcription factor-κB （NF-κB） and hypoxia inducible factor-1α （HIF-1α） in colon tissue was detected by Real-time quantitative polymerase chain reaction （Real-time PCR） and Western blot. ResultCompared with the normal group， the body weight， colon length and IL-10 content in the model group were significantly decreased （P<0.01）， DAI score， intestinal weight index， CMDI score， IL-6 and TNF-α contents， and mRNA and protein expression levels of TLR4， NF-κB and HIF-1α in the model group were significantly increased （P<0.01）. Moreover， the structure of colonic mucosa was destroyed and inflammatory cells infiltrated in the model group. Compared with model group， body weight， colon length and IL-10 content in each dose group of Xielitang were significantly increased （P<0.05， P<0.01）， DAI score， intestinal weight index and CMDI score， IL-6 and TNF-α contents， mRNA and protein expression levels of TLR4， NF-κB and HIF-1α were notably decreased （P<0.05， P<0.01）. The pathological injury of colon was obviously alleviated. ConclusionXielitang can significantly improve the inflammatory response of UC mice induced by DSS， and its mechanism may be related to the regulation of TLR4/NF-κB/HIF-1α signaling pathway.

miR-7/TGF-β2 axis sustains acidic tumor microenvironment-induced lung cancer metastasis

Acidosis, regardless of hypoxia involvement, is recognized as a chronic and harsh tumor microenvironment (TME) that educates malignant cells to thrive and metastasize. Although overwhelming evidence supports an acidic environment as a driver or ubiquitous hallmark of cancer progression, the unrevealed core mechanisms underlying the direct effect of acidification on tumorigenesis have hindered the discovery of novel therapeutic targets and clinical therapy. Here, chemical-induced and transgenic mouse models for colon, liver and lung cancer were established, respectively. miR-7 and TGF-β2 expressions were examined in clinical tissues (n = 184). RNA-seq, miRNA-seq, proteomics, biosynthesis analyses and functional studies were performed to validate the mechanisms involved in the acidic TME-induced lung cancer metastasis. Our data show that lung cancer is sensitive to the increased acidification of TME, and acidic TME-induced lung cancer metastasis via inhibition of miR-7-5p. TGF-β2 is a direct target of miR-7-5p. The reduced expression of miR-7-5p subsequently increases the expression of TGF-β2 which enhances the metastatic potential of the lung cancer. Indeed, overexpression of miR-7-5p reduces the acidic pH-enhanced lung cancer metastasis. Furthermore, the human lung tumor samples also show a reduced miR-7-5p expression but an elevated level of activated TGF-β2; the expressions of both miR-7-5p and TGF-β2 are correlated with patients' survival. We are the first to identify the role of the miR-7/TGF-β2 axis in acidic pH-enhanced lung cancer metastasis. Our study not only delineates how acidification directly affects tumorigenesis, but also suggests miR-7 is a novel reliable biomarker for acidic TME and a novel therapeutic target for non-small cell lung cancer (NSCLC) treatment. Our study opens an avenue to explore the pH-sensitive subcellular components as novel therapeutic targets for cancer treatment.

Optimization and establishment of therapeutic model of Bletilla striata polysaccharide on dextran sodium sulfate-induced ulcerative colitis in mice / 西安交通大学学报(医学版)

【Objective】 To establish the optimal treatment model of Bletilla striata polysaccharide （BSP） on dextran sodium sulfate （DSS）-induced ulcerative colitis （UC） in mice. 【Methods】 We randomly divided 48 male C57BL/6 mice into normal control group， DSS model group （25 g/L DSS）， BSP low-， medium- and high-dose groups （25 g/L DSS + 95， 190， 380 mg/kg BSP）， and salazosulfapyridine （SASP） （25 g/L DSS + 320 mg/kg SASP， positive control） group. Mice in the normal control group drank distilled water freely， while the other groups were given 25 g/L DSS solution to drink freely for 7 days. From the second day， the low-， medium- and high-dose BSP groups and SASP （positive control）group were administered by gavage according to body mass. The normal control group and DSS model group were given the same amount of normal saline once a day for 7 consecutive days. The mice’s blood pressure was recorded every day. Mental state， body mass， stool characteristics and bloody stool were used to calculate the mice’s disease activity index （DAI）. The mice were killed on the 9th day， and their colonic tissues were taken for hematoxylin eosin （HE） staining and histopathological scoring. The expression of tight junction protein Claudin-1 in colonic tissues was detected by Western blotting. 【Results】 Compared with the normal control group， the DSS model group had obvious clinical manifestations， histopathological changes and reduced body weight， increased histopathological score and DAI score （P<0.05）， and decreased expression of tight junction protein Claudin-1 in colon tissue （P<0.05）. Compared with those in DSS model group， the clinical manifestations of UC and colonic mucosal injury in low-， medium- and high-dose BSP groups were improved in varying degrees. The high-dose （380 mg/kg） BSP group had the best effect. The degree of body weight reduction， histopathological score and DAI score in this group were significantly lower than those in DSS model group （P<0.05）， whereas the expression of Claudin-1 increased significantly （P<0.05）. 【Conclusion】 When BSP was administered by gavage at 380 mg/kg， the therapeutic effect on UC mice induced by 25 g/L DSS was the best. This model can be used as an effective one for further studies on Striata Bletilla polysaccharide in UC mice.

Resolvin D1 mitigates inflammatory response in DSS-induced colitis mice by inhibiting NLRP3 inflammasome activation / 中国药理学通报

Aim: To investigate the effect of resolvin Dl (RvDl) on DSS-induced mice colitis model and the possible mechanism. Methods: C57BL/6 mice were divided into four groups: normal group, control group, dextran sodium sulfate (DSS) model group, and RvDl group. RvDl was dissolved in physiological saline and intraperitoneally injected into experimental mice on 2nd day, 4th day and 6th day. The disease activity index (DAI), histological index (HI), myeloperoxidase (MPO) were detected using Evans blue test, electron microscopy and cytokine level test. The expression differences of NLRP3, ASC, caspase-1, pro-IL-1 β and other related genes were analyzed. Results: The DAI score, HI score, MPO activity level, and pro-inflammatory cytokine in colon tissue homogenate were significantly raised in DSS group compared with those of the normal group (P < 0. 05). The above indexes of RvDl experimental group were significantly reduced(P < 0. 05). At the same time, the expressions of NPRP3 pathway-related proteins, such as NLRP3, ASC, caspase-1 and pro-IL-1 (3, increased in DSS group(F < 0. 05); the expression of the above proteins decreased after RvDl treatment(P < 0. 05). Conclusions: RvDl can mitigate inflammatory response in DSS-induced colitis mice, which may involve the inhibition of RvDl of the NLRP3 inflammasome signaling pathway.

Therapeutic effects of dendrobium officinale extract on ulcerative colitis model of BALB/c mice / 中国药理学通报

Aim: To explore the therapeutic effects of Dendrobium officinale extract on mice with ulcerative colitis(UC) and its mechanism. Methods: The mice were treated with 4% DSS to induce the UC model. The signs or symptom changes of mice were observed and recorded. Then the scores of disease activity index (DAI) during the days of modeling and drug treatment were also evaluated, and the colon tissues were taken as samples. The samples were used for general and microscopic evaluation, the expression of MPO was detected by Western blot, and the expressions of IFN-γ and TNF-α mRNA were measured by qPCR. Meanwhile, the concentrations of serum IFN-γ, TNF-α in mice were also determined by ELISA. Results: As compared with model group, the colon length of mice treated with Dendrobium officinale extract was longer. The DAI score, histological damage score were reduced (P <0. 05 or P <0. 01); the concentrations of IFN-7 and TNF-α inflammatory cytokines in serum decreased (P < 0. 05); the expressions of IFN-γ mRNA and MPO protein in the colon tissue significantly decreased compared with model group (P < 0. 05). Conclusions: Dendrobium officinale extract could treat DSS-induced UC of BALB/c mice. The anti-UC mechanism of Dendrobium officinale extract can be attributed to its ability to reduce the release of IFN-γ and TNF-α and downregulate the expressions of IFN-γ, TNF-α and MPO, to block the amplification effect of inflammation and to achieve its therapeutic effects.

From Gut to Brain: Alteration in Inflammation Markers in the Brain of Dextran Sodium Sulfate-induced Colitis Model Mice

OBJECTIVE: Neuropsychiatric manifestations like depression and cognitive dysfunction commonly occur in inflammatory bowel disease (IBD). In the context of the brain-gut axis model, colitis can lead to alteration of brain function in a bottom-up manner. Here, the changes in the response of the hypothalamic-pituitary-adrenal axis and inflammation-related markers in the brain in colitis were studied. METHODS: Dextran sodium sulfate (DSS) was used to generate a mouse model of colitis. Mice were treated with DSS for 3 or 7 days and sacrificed. We analyzed the gene expression of brain-derived neurotrophic factor (BDNF), cyclo-oxygenase 2 (COX-2), and glial fibrillary acidic protein (GFAP), and the expression of GFAP, in the hippocampus, hypothalamus, and amygdala. Additionally, the levels of C-reactive protein (CRP) and serum cortisol/corticosterone were measured. RESULTS: Alteration of inflammatory-related markers varied depending on the brain region and exposure time. In the hippocampus, COX-2 mRNA, GFAP mRNA, and GFAP expression were upregulated during exposure to DSS. However, in the hypothalamus, COX-2 mRNA was upregulated only 3 days after treatment. In the amygdala, BDNF and COX-2 mRNAs were downregulated. CRP and corticosterone expression increased with DSS treatment at day 7. CONCLUSION: IBD could lead to neuroinflammation in a bottom-up manner, and this effect varied according to brain region. Stress-related hormones and serum inflammatory markers, such as CRP, were upregulated from the third day of DSS treatment. Therefore, early and active intervention is required to prevent psychological and behavioral changes caused by IBD, and region-specific studies can help understand the precise mechanisms by which IBD affects the brain.

The inhibitory effect of N-p-chlorobenzenesulfonyl-4-aminosalicylic acid on dextran sodium sulfate-induced ulcerative colitis / 药学学报

The study aims to explore the effects of N-p-chlorobenzenesulfonyl-4-amino salicylic acid on the dextran sodium sulfate (DSS)-induced ulcerative colitis in mouse. A total of 60 BALB/c mice were randomly divided into 6 groups (n=10):control group, DSS model group, 5-amino salicylic acid (5-ASA) group, and administration groups (N-p-chlorobenzenesulfonyl-4-aminosalicylic acid) 10, 20, 40 mg·kg-1. Model group were induced by drinking 4% (w/v) DSS solution for 7 days and normal water for the next 3 days. The positive group and drug group mouse were given 5-ASA (40 mg·kg-1) and N-p-chlorobenzene sulfonyl-4-amino salicylic acid (10, 20, 40 mg·kg-1) by gavage respectively. During the experiment, changes in body weight, bloody stool, fecal character and mental status were observed daily. Damage and repair of the colon mucosa and the pathological changes of important organs were observed by hematoxylin and eosin (HE) staining. Expression of inflammatory factors such as tumor necrosis factor alpha (TNF-α), interleukin 1 beta (IL-1β), interleukin 6 (IL-6), macrophage inflammatory protein 2 (MIP-2), myeloperoxidase (MPO) in serum were detected by ELISA. The results showed that bloody stools and diarrhea emerged on the 4th day after model establishment in model mice. The number of bloody mice rose to ten, and blood and diarrhea began to appear in the administration group on the 7th day. Mental status was poor and body weight decreased significantly in model group since the 4th day, and the situation was improved in the administration group and 5-ASA group. Colons in the administration groups (10, 20, 40 mg·kg-1) were longer than those in the DSS model group. In the DSS model group, the colonic mucosa and submucosa of mice exhibited severe inflammatory cell infiltration, various degrees of necrosis, proliferation. In the middle dose group (20 mg·kg-1), the situation has improved slightly and the colonic mucosa showed mildly chronic inflammation and a small amount of inflammatory cells infiltration. The high dose group (40 mg·kg-1) showed normal colon mucosal, relatively complete epithelial structure and few inflammatory cell infiltration. The levels of IL-1β, IL-6, TNF-α, MIP-2 and MPO in the serum of mice were lower in the administration group (40 mg·kg-1) than in model group. Therefore, N-p-chlorobenzenesulfonyl-4-amino salicylic acid might be a feasible treatment for DSS-induced UC.

Cortical Inflammation is Increased in a DSS-Induced Colitis Mouse Model / 神经科学通报·英文版

While inflammatory bowel disease (IBD) might be a risk factor in the development of brain dysfunctions, the underlying mechanisms are largely unknown. Here, mice were treated with 5% dextran sodium sulfate (DSS) in drinking water and sacrificed on day 7. The serum level of IL-6 increased, accompanied by elevation of the IL-6 and TNF-α levels in cortical tissue. However, the endotoxin concentration in plasma and brain of mice with DSS-induced colitis showed a rising trend, but with no significant difference. We also found significant activation of microglial cells and reduction in occludin and claudin-5 expression in the brain tissue after DSS-induced colitis. These results suggested that DSS-induced colitis increases systemic inflammation which then results in cortical inflammation via up-regulation of serum cytokines. Here, we provide new information on the impact of colitis on the outcomes of cortical inflammation.

Brugia malayi abundant larval transcript 2 protein treatment attenuates experimentally-induced colitis in mice.

Helminths are known to modulate host’s immunity by suppressing host protective pro-inflammatory responses. Such immunomodulatory effects have been experimentally shown to have therapeutic implications in immune mediated disorders. In the present study, we have explored a filarial protein i.e. Brugia malayi recombinant abundant larval transcript 2 (rBmALT2) for its therapeutic effect in dextran sodium sulfate (DSS) induced colitis in mouse model. The immunomodulatory activity of rBmALT-2 was initially confirmed by demonstrating that it suppressed the lipopolysaccharide (LPS) induced nitric oxide synthesis and down-regulated the expression of pro-inflammatory cytokines in vitro by peritoneal exudate cells of mice. Treatment with rBmALT2 reduced severity of colitis associated with significant reduction in weight loss, disease activity, colon damage, mucosal edema and histopathological score including myeloperoxidase activity in colon tissues. rBmALT2 was comparatively more effective in attenuation of colitis when used in the preventive mode than when used for curative purpose. The therapeutic effect of rBmALT2 was found to be associated with downregulation of IFN-γ, IL-6, IL-17 and upregulation of IL-10 cytokines. These results provide strong experimental evidence that BmALT2 could be a potential alternative therapeutic agent in colitis.

Establishment and evaluation of a model of acute colitis induced by dextran sodium sulfate in C57BL/6 mice / 医学研究生学报

Objective The expression and impaired function of ion channels might be one of the pathophysiological mecha -nisms responsible for diarrhea in inflammatory bowel disease ( IBD) .Proper animal model is the key to explore detailed pathophysiolog-ical process.The purpose of this study was to build a rat model of acute colitis induced by dextran sodium sulfate (DSS) in C57BL/6 mice and evaluate diarrhea-associated clinical , histological , pathological parameters and expressions of ion channel protein . Methods C57BL/6J mice of model group were treated with 4%DSS solution for 7 days to induce acute colitis.Mice body weight, stool moisture, stool consistency and the degree of hematochezia were recorded .The histopathological changes of mice colon specimens were observed visually and microcosmically, and the ion channel SLC26A3 protein was detected by Western Blot . Results All experimental mice survived.In the experiment, compared with control group , bloody diarrhea and weight lose occurred in model group , along with increased stool moisture ([73.30 ±8.31]% after experiment vs [44.32 ±6.42]% before experiment, P=0.004), and rapidly in-creased disease activity index (DAI) of acute colitis ([3.50 ±0.87] after experiment vs [1.0 ±0.00] before experiment, P=0.000).At the end of this experiment , compared with control group , the model group resulted in higher colonic damage score and pathological inflammation score (P=0.00, P=0.002), significantly shortened co-lon (P=0.00) and decreased expression of SLC26A3. Conclusion The intestinal mucosal injury and phenotypic features of 4%DSS-induced acute colitis are very similar to those of human ulcerative colitis .Impaired expression of intestinal ion transporter SLC26 A3 coexists with diarrhea in model group mice , and this model can support the research on mechanism of functional changes of ion channels in inflammatory diarrhea .

Effects of Selenium on Colon Carcinogenesis Induced by Azoxymethane and Dextran Sodium Sulfate in Mouse Model with High-Iron Diet / 한국실험동물학회지

Selenium (Se) is known to prevent several cancers while the relationship between high iron and the risk of colorectal cancer is controversial. To investigate the effects of Se in colon carcinogenesis, we subjected three different levels of Se and high-iron diet to a mouse model of colon cancer in which animals were treated with three azoxymethane (AOM) injections followed by dextran sodium sulfate (DSS) administration. There were five experimental groups including vehicle group [normal-Fe (NFe, 45 ppm)+medium-Se (MSe, 0.1 ppm)], positive control group (AOM/DSS+NFe+MSe), AOM/DSS+high-Fe (HFe, 450 ppm)+low-Se (LSe, 0.02 ppm), AOM/DSS+HFe+MSe, and AOM/DSS+HFe+high-Se (HSe, 0.5 ppm). The animals were fed on the three different Se diets for 24 weeks. The incidence of colon tumor in the high-Se diet group (AOM/DSS+HFe+HSe) showed 19.4% lower than positive control group, 5.9% lower than AOM/DSS+HFe+MSe diet group, and 11.1% lower than AOM/DSS+HFe+LSe group. The tumor multiplicity was significantly higher in the low-Se diet group (AOM/DSS+HFe+LSe) compare to all other AOM/DSS treated groups. In the high-Se diet group, the activity of hepatic GPx was comparable to that of positive control group, and significantly higher than those of low-Se or medium-Se diet groups. Expression level of hepatic GPx-1 showed similar results. Hepatic malondialdehyde (MDA) level (indicator of oxidative stress) in the low-Se diet group showed the highest compared to the other groups, and it was significantly higher than positive control group. In the high-Se diet group the level of MDA in the liver was significantly lower than all other AOM/DSS treated groups. High-Se diet group showed significantly lower proliferative index than low-Se and medium-Se groups. The apoptotic indices in low-Se group and medium-Se group were significantly lower than positive control group. However, apoptotic index of high-Se diet group was significantly higher than all other AOM/DSS treated groups. These findings suggest that dietary Se supplement may have protective effect against colon cancer by decreasing proliferation, increasing apoptosis of tumor cells, and reducing oxidative stress in mice with high iron diet.

Parasitic Helminth Cystatin Inhibits DSS-Induced Intestinal Inflammation Via IL-10+F4/80+ Macrophage Recruitment

Many immune down-regulatory molecules have been isolated from parasites, including cystatin (cystain protease inhibitor). In a previous study, we isolated and characterized Type I cystatin (CsStefin-1) of the liver fluke, Clonorchis sinensis. To investigate whether the CsStefin-1 might be a new host immune modulator, we induced intestinal inflammation in mice by dextran sodium sulfate (DSS) and treated them with recombinant CsStefin-1 (rCsStefin-1). The disease activity index (DAI) increased in DSS only-treated mice. In contrast, the DAI value was significantly reduced in rCsStefin-1-treated mice than DSS only-treated mice. In addition, the colon length of DSS only-treated mice was shorter than that of rCsStefin-1 treated mice. The secretion levels of IFN-gamma and TNF-alpha in the spleen and mesenteric lymph nodes (MLNs) were significantly increased by DSS treatment, but the level of TNF-alpha in MLNs was significantly decreased by rCsStefin-1 treatment. IL-10 production in both spleen and MLNs was significantly increased, and IL-10+F4/80+ macrophage cells were significantly increased in the spleen and MLNs of rCsStefin-1 treated mice after DSS treatment. In conclusion, rCsStefin-1 could reduce the intestinal inflammation occurring after DSS treatment, these effects might be related with recruitment of IL-10 secreting macrophages.

Th17 Responses Are Not Induced in Dextran Sodium Sulfate Model of Acute Colitis

Dextran sodium sulfate (DSS) is a widely used chemical model for inflammatory bowel disease (IBD). It is thought that imbalances in the T helper (Th) cell subsets contribute to IBD. Recent studies suggest that the acute DSS-colitis model is polarized toward a Th1/Th17 profile based on RT-PCR analysis of colonic tissues. In the current study we determined whether colonic Th cells from DSS-colitis mice were skewed toward the Th17 profile. Mice were treated with 5% DSS for 7 days and colonic T cells isolated and examined for production of IFN-gamma (Th1 cell), IL-4 (Th2 cell) and IL-17 (Th17 cell) by intracellular flow cytometry. We found that the percentage of colonic Th17 cells were similar to non-treated controls but the percentage of Th1 cells were elevated in DSS-colitis mice. These results suggest that in the acute DSS-colitis model the colonic Th cells exhibit a Th1 profile and not a Th17 profile.

Dietary Selenium Supplement Prevents Colon Carcinogenesis Induced by Azoxymethane and Dextran Sodium Sulfate in ICR Mice / 한국실험동물학회지

The role of selenium (Se) in modulating colon carcinogenesis induced by azoxymethane (AOM) followed by dextran sodium sulfate (DSS) was investigated in mice. Five-week old ICR mice were fed on diets containing different concentrations (0.02, 0.1 or 0.5 ppm) of Se for 24 weeks. Animals received three (0-2nd weeks) intraperitoneal injections of AOM (10 mg/kg body weight), followed by 2% DSS with drinking water for additional 1 week. There were 4 experimental groups including vehicle control group, positive control group given AOM/DSS with AIN-93G normal diet containing 0.1% Se (NSe), a low (0.02 ppm)-Se diet group (LSe) and a high (0.5 ppm)-Se diet group (HSe). Hematology was analyzed with a blood cell differential counter. Liver Se was analyzed by inductively coupled plasma-mass spectroscopy. Cell proliferation and apoptosis were determined by using proliferating cell nuclear antigen (PCNA) for proliferative activity and apoptotic index by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL), respectively. HSe group showed a low incidence of colonic tumor (64.7%), compared with the NSe positive control (75%) and LSe (77.8%) groups. In contrast, HSe group exhibited lower rate of PCNA-positive cells (39.3+/-6.9%) than positive control (64.3+/-0.3%) and LSe (57.3+/-2.9%) groups. In addition, apoptotic index of HSe group was higher than those of positive control and LSe groups. These results indicate that Se is a chemopreventive agent for colon carcinogenesis induced by AOM+DSS in male ICR mice.

Dietary Selenium Supplement Prevents Colon Carcinogenesis Induced by Azoxymethane and Dextran Sodium Sulfate in ICR Mice / 한국실험동물학회지

The role of selenium (Se) in modulating colon carcinogenesis induced by azoxymethane (AOM) followed by dextran sodium sulfate (DSS) was investigated in mice. Five-week old ICR mice were fed on diets containing different concentrations (0.02, 0.1 or 0.5 ppm) of Se for 24 weeks. Animals received three (0-2nd weeks) intraperitoneal injections of AOM (10 mg/kg body weight), followed by 2% DSS with drinking water for additional 1 week. There were 4 experimental groups including vehicle control group, positive control group given AOM/DSS with AIN-93G normal diet containing 0.1% Se (NSe), a low (0.02 ppm)-Se diet group (LSe) and a high (0.5 ppm)-Se diet group (HSe). Hematology was analyzed with a blood cell differential counter. Liver Se was analyzed by inductively coupled plasma-mass spectroscopy. Cell proliferation and apoptosis were determined by using proliferating cell nuclear antigen (PCNA) for proliferative activity and apoptotic index by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL), respectively. HSe group showed a low incidence of colonic tumor (64.7%), compared with the NSe positive control (75%) and LSe (77.8%) groups. In contrast, HSe group exhibited lower rate of PCNA-positive cells (39.3+/-6.9%) than positive control (64.3+/-0.3%) and LSe (57.3+/-2.9%) groups. In addition, apoptotic index of HSe group was higher than those of positive control and LSe groups. These results indicate that Se is a chemopreventive agent for colon carcinogenesis induced by AOM+DSS in male ICR mice.

The changes of osteopontin expression in exprerimental murine colitis / 中华消化杂志

Objective To investigate the changes of osteopontin (OPN) expression in murine colitis induced by dextran sodium sulfate (DSS) and its role in inflammatory bowel disease (IBD).MethodsThirty-two male BALB/C mice were randomly assigned into 4 groups: control group (group A), DSS-induced murine colitis model group (group B), salazosulfapyridine treatment group (group C) and infliximab treatment group (group D). Plasma OPN concentration was measured by enzyme linked immunosorbent assay (ELISA). OPN mRNA level was detect by using reverse transcriptase polymerase chain reaction (RT-PCR) and protein expression in colonic tissues was analyzed by using Western blotting. The location expression of OPN in colonic tissues was determined by immunohistochemical staining. ResultsIn group A, B,C and D, the plasma concentrations of OPN were (5.26±1.93) ng/ml, (10.21±2.37) ng/ml, (4.58±1.83) ng/ml and (4.82±1.83) ng/ml,respectively: the mRNA levels of OPN in colonic tissues were (0.36±0.16), (0.71±0.17),(0.32±0.07) and (0. 34±0. 08), respectively; the protein levels of OPN in colonic tissues were (0.44±0.10), (0.85±0.04), (0.61±0.11) and (0.58±0.17), respectively. The OPN-positive cell numbers in lamina propria mononuclear were (46.6±10.9), (155.5±43.8), (73.1±6.8) and (70.6±8.3), respectively. The expression of OPN in group B was significantly higher than that in group A (P<0.05). Compared with group B, the expressions of OPN in group C and D were significantly decreased (all P valus <0. 05). No significant difference was detected between group C and D. Conclusions The study shows that the expression of OPN significantly increased in DSS-induced murine colitis and decreased after treated with drugs. OPN-mediated immune response contributes to DSS-induced murine colitis.