Involvement of lymphocytes in dextran sulfate sodium-induced experimental colitis

AIM: To investigate the roles of lymphocytes in the development of dextran sulfate sodium-induced colitis. METHODS: Using various doses of dextran sulfate sodium (DSS), we induced colitis in wild-type B6 control and Rag-1 knockout (H-2b haplotype) mice, and evaluated the colitis in terms of symptomatic and histologic parameters, such as weight loss, survival, severity of diarrhea, shortage of colon length and histological changes. Symptomatic parameters were checked daily and histological changes were scored. RESULTS: Although development of colitis in Rag-1 knockout mice treated with high dose (5%) of DSS was comparable to that in B6 control mice, colitis progression was much more tolerable in Rag-1 knockout mice compared to than in B6 mice treated with low dose (1.5%) DSS. Symptomatic parameters as well as histopathologic changes were improved in Rag-1 knockout mice. CONCLUSION: These results indicate that the presence of lymphocytes contributes to colitis progression at low dose of DSS stimulation. Lymphocytes may play roles as an aggravating factor in DSS-induced colitis.     

Kefir treatment ameliorates dextran sulfate sodium-induced colitis in rats

AIM: To investigate the preventive effect of kefir on colitis induced with dextran sulfate sodium(DSS) in rats.METHODS: Twenty-four male Wistar-albino rats were randomized into four groups: normal control,kefircontrol,colitis,and kefir-colitis groups. Rats in the normal and kefir-control groups were administered tap water as drinking water for 14 d. Rats in the colitis and kefir-colitis groups were administered a 3% DSS solution as drinking water for 8-14 d to induce colitis. Rats in the kefir-control and kefir-colitis groups were administered 5 m L kefir once a day for 14 d while rats in the normal control and colitis group were administered an identical volume of the placebo(skim milk) using an orogastric feeding tube. Clinical colitis was evaluated with reference to the disease activity index(DAI),based on daily weight loss,stool consistency,and presence of bleeding in feces. Rats were sacrificed on the 15 th day,blood specimens were collected,and colon tissues were rapidly removed. Levels of myeloperoxidase(MPO),tumor necrosisfactor(TNF)-α,interleukin(IL)-10,malondialdehyde,and inducible nitric oxide synthase(i NOS) were measured in colon tissue.RESULTS: The DAI was lower in the kefir-colitis group than in the colitis group(on the 3rd and 5th days of colitis induction; P 0.01). The DAI was also significantly higher in the colitis group between days 2 and 6 of colitis induction when compared to the normal control and kefir-control groups. The DAI was statistically higher only on the 6th day in the kefircolitis group when compared to that in the normal control groups. Increased colon weight and decreased colon length were observed in colitis-induced rats. Mean colon length in the colitis group was significantly shorter than that of the kefir-control group. Kefir treatment significantly decreased histologic colitis scores(P 0.05). MPO activity in the colitis group was significantly higher than in the kefir-control group(P 0.05). Kefir treatment significantly reduced the DSS colitis-induced TNF-α increase(P 0.01). No statistically significant differences were observed among groups for IL-10 and MDA levels. Colon tissue i NOS levels in the colitis group were significantly higher than those in the control and kefir-colitis groups(P 0.05).CONCLUSION: Kefir reduces the clinical DAI and histologic colitis scores in a DSS-induced colitis model,possibly via reduction of MPO,TNF-α,and i NOS levels.     

Dextran sulfate sodium-induced acute colitis impairs dermal lymphatic function in mice

AIM: To investigate whether dermal lymphatic function and architecture are systemically altered in dextran sulfate sodium (DSS)-induced acute colitis.METHODS: Balb/c mice were administered 4% DSS in lieu of drinking water ad libitum for 7 d and monitored to assess disease activity including body weight, diarrhea severity, and fecal bleeding. Control mice received standard drinking water with no DSS. Changes in mesenteric lymphatics were assessed following oral administration of a fluorescently-labelled fatty acid analogue, while dermal lymphatic function and architecture was longitudinally characterized using dynamic near-infrared fluorescence (NIRF) imaging following intradermal injection of indocyanine green (ICG) at the base of the tail or to the dorsal aspect of the left paw prior to, 4, and 7 d after DSS administration. We also measured dye clearance rate after injection of Alexa680-bovine serum albumin (BSA). NIRF imaging data was analyzed to reveal lymphatic contractile activity after selecting fixed regions of interest (ROIs) of the same size in fluorescent lymphatic vessels on fluorescence images. The averaged fluorescence intensity within the ROI of each fluorescence image was plotted as a function of imaging time and the lymphatic contraction frequency was computed by assessing the number of fluorescent pulses arriving at a ROI.RESULTS: Mice treated with DSS developed acute inflammation with clinical symptoms of loss of body weight, loose feces/watery diarrhea, and fecal blood, all of which were aggravated as disease progressed to 7 d. Histological examination of colons of DSS-treated mice confirmed acute inflammation, characterized by segmental to complete loss of colonic mucosa with an associated chronic inflammatory cell infiltrate that extended into the deeper layers of the wall of the colon, compared to control mice. In situ intravital imaging revealed that mice with acute colitis showed significantly fewer fluorescent mesenteric lymphatic vessels, indicating impaired uptake of a lipid tracer within mesenteric lymphatics. Our in vivo NIRF imaging data demonstrated dilated dermal lymphatic vessels, which were confirmed by immunohistochemical staining of lymphatic vessels, and significantly reduced lymphatic contractile function in the skin of mice with DSS-induced acute colitis. Quantification of the fluorescent intensity remaining in the depot as a function of time showed that there was significantly higher Alexa680-BSA fluorescence in mice with DSS-induced acute colitis compared to pre-treatment with DSS, indicative of impaired lymphatic drainage.CONCLUSION: The lymphatics are locally and systemically altered in acute colitis, and functional NIRF imaging is useful for noninvasively monitoring systemic lymphatic changes during inflammation.     

葡聚糖硫酸钠诱导小鼠实验性结肠炎的临床和组织病理学特征研究

目的研究葡聚糖硫酸钠(DSS)诱导小鼠实验性结肠炎的临床和病理特征,以便于指导选择合适的溃疡性结肠炎(ulcerative colitis,UC)小鼠模型。方法予3%DSS溶液喂饲野生型C57BL/6成年小鼠诱导急性结肠炎模型,分别于第0天、第3天、第5天、第7天和第10天麻醉处死小鼠,取结肠观察不同时期结肠病理学特征,造模过程中连续观察并记录小鼠体质量、大便和死亡情况。结果小鼠造模第3天开始出现粪便潜血,第5天开始出现血便,第10天开始出现死亡小鼠,死亡率为30%。DSS诱导小鼠急性结肠炎模型疾病活动指数第3天后与饮用纯净水的小鼠比较明显增高(P0.05)。小鼠结肠炎造模第3天黏膜上皮细胞开始逐渐丧失,第7~10天最为严重;隐窝结构的紊乱从第3天开始发生,第7天出现固有层塌陷;炎性细胞浸润从第3天开始数量逐渐增加,第10天最为严重。DSS诱导小鼠急性结肠炎模型结肠组织病理评分第5天后与饮用纯净水的小鼠比较明显增高(P0.05)。结论 3%DSS诱导野生型C57BL/6成年小鼠急性结肠炎模型可用于UC的实验研究,第3天出现明显的炎症表现,第7天模型较理想,小鼠死亡少。     

肝素治疗右旋葡聚糖硫酸钠诱导小鼠结肠炎的疗效观察

目的　评价肝素预防及治疗右旋葡聚糖硫酸钠 (DSS)诱导小鼠结肠炎的有效性。方法　32只小鼠中 ,16只正常小鼠分成两组 ,饮用DSS 7d的同时预防组皮下注射肝素 ,对照组皮下注射生理盐水 ;另 16只饮用DSS 7d后诱导结肠炎的小鼠分成两组 ,治疗组皮下注射肝素 ,对照组皮下注射生理盐水。用疾病活动指数、组织学评分、TNF α的表达和马休斯猩红兰 (MSB)检测微血栓评价疗效。结果　肝素在预防组降低微血栓的形成 ,对照组 8只中 4只微血栓阳性 ,预防组均阴性 (P =0 .0 38)。治疗组组织学评分、TNF α的表达明显降低 ,治疗组与对照组的直肠、横结肠组织学评分和TNF α的表达分别为 1.33和 1.85 (P <0 .0 5 ) ,0 .92和 1.6 8(P <0 .0 5 ) ,(5 .5± 3.5 ) %和 (10 .8± 4.2 ) % (P <0 .0 5 )。结论　肝素可抑制DSS诱导结肠炎小鼠血栓形成和结肠炎症 ,实验结果提示肝素用于溃疡性结肠炎治疗也可能有效     

Temporal clinical,proteomic, histological and cellular immune responses of dextran sulfate sodium-induced acute colitis

AIM To investigate the temporal clinical, proteomic, histological and cellular immune profiles of dextran sulfate sodium(DSS)-induced acute colitis.METHODS Acute colitis was induced in C57 BL/6 female mice by administration of 1%, 2% or 3% DSS in drinking water for 7 d. Animals were monitored daily for weight loss, stool consistency and blood in the stool, while spleens and colons were harvested on day 8. A time course analysis was performed in mice ingesting 3% DSS, which included colon proteomics through multiplex assay, colon histological scoring by a blinded investigator, and immune response through flow cytometry or immunohistochemistry of the spleen, mesenteric lymph node and colon.RESULTS Progressive worsening of clinical colitis was observed with increasing DSS from 1% to 3%. In mice ingesting 3% DSS, colon shortening and increase in proinflammatory factors starting at day 3 was observed, with increased spleen weights at day 6 and day 8. This coincided with cellular infiltration in the colon from day 2 to day 8, with progressive accumulation of macrophages F4/80~+, T helper CD4~+(Th), T cytotoxic CD8~+(Tcyt) and T regulatory CD25~+(Treg) cells, and progressive changes in colonic pathology including destruction of crypts, loss of goblet cells and depletion of the epithelial barrier. Starting on day 4, mesenteric lymph node and/or spleen presented with lower levels of Treg, Th and Tcyt cells, suggesting an immune cell tropism to the gut. CONCLUSION These results demonstrate that the severity of experimental colitis is dependent on DSS concentration, correlated with clinical, proteomic, histological and cellular immune response on 3% DSS.     

Antibody to eosinophil cationic protein suppresses dextran sulfate sodium-induced colitis in rats

AIM: To produce an antibody against rat eosinophil cationic protein (ECP) and to examine the effects of the antibody in rats with dextran sulfate sodium (DSS)-induced colitis. METHODS: An antibody was raised against rat ECP. Rats were treated with 3% DSS in drinking water for 7 d and received the antibody or normal serum. The colons were examined histologically and correlated with clinical symptoms. Immunohistochemistry and Western blot analysis were estimated as a grade of inflammation. RESULTS: The ECP antibody stained the activated eosinophils around the injured crypts in the colonic mucosa. Antibody treatment reduced the severity of colonic ulceration and acute clinical symptoms (diarrhea and/or bloodstained stool). Body weight gain was significantly greater and the colon length was significantly longer in anti-ECP-treated rats than in normal serum-treated rats. Expression of ECP in activated eosinophils was associated with the presence of erosions and inflammation. The number of Ki-67-positive cells in the regenerated surface epithelium increased in anti-ECP-treated rats compared with normal serum-treated rats. Western blot analysis revealed reduced expression of macrophage migration inhibitory factor (MIF) in anti-ECP-treated rats. CONCLUSION: Our results indicate that treatment with ECP antibody, improved DSS-induced colitis in rats, possibly by increasing the regenerative activity of the colonic epithelium and downregulation of the immune response, and suggest that anti-ECP may promote intestinal wound healing in patients with ulcerative colitis (UC).     

Dysplasia and carcinoma development in a repeated dextran sulfate sodium-induced colitis model

BACKGROUND: As an important mechanism underlying the increased risk of colorectal carcinoma development in patients with long-standing ulcerative colitis, promotion as a result of the regenerative process has been proposed. In the present study, a dysplasia-carcinoma sequence in a novel repeated colitis model in mice is documented. METHODS: Repeated colitis was induced by nine administration cycles of 3% dextran sulfate sodium (DSS; molecular weight, 54 000): each administration cycle comprised 3% DSS for 7 days followed by distilled water for the subsequent 14 days, to give conditions similar to the clinically observed active and remission phases in humans. RESULTS: Multiple colorectal tumors (nine low- and four high-grade dysplasias and two carcinomas) developed in 25 mice. These neoplastic lesions consisted of tubular structures, presenting as various types of elevated, flat and depressed tumor, similar to those in ulcerative colitis patients. A time-course study with assessment of the severity of colitis and in vivo bromodeoxyuridine uptake during a single 3% DSS administration cycle revealed a high level of regenerative activity in the colitis-affected mucosal epithelia. CONCLUSION: Thus, with the present repeated colitis model, regeneration and neoplastic lesions were apparent, the biological features of which provide evidence of a colorectal dysplasia-invasive carcinoma sequence in ulcerative colitis.     

T辅助细胞在右旋葡聚糖硫酸钠诱导的小鼠结肠炎中的作用研究

目的　探讨Th1/Th2细胞在右旋葡聚糖硫酸钠 (DSS)诱导小鼠结肠炎中的作用。方法　利用细胞内细胞因子流式细胞检测法 ,测定DSS诱导急、慢性结肠炎小鼠肠黏膜和脾脏单核细胞 (SMC)中Th1/Th2比例。结果　①结肠炎急性期 ,小鼠肠黏膜固有层单核细胞 (LPMC)中Th1细胞为 (8.90± 1.2 3) % ,较对照组升高 (P <0 .0 5 ) ;Th2细胞占 (3.2 5± 1.2 5 ) % ,与对照组差异无显著性 (P >0 .0 5 ) ;Th1/Th2比例为 3.0 9± 1.18,较对照组升高 (P <0 .0 5 )。②在慢性期 ,肠黏膜LPMC中Th1、Th2细胞分别占 (5 .5 2± 1.2 8) %和 (10 .0 8± 1.75 ) % ,均较对照组升高 (P <0 .0 5 ) ;Th1/Th2比例为 0 .5 2± 0 .2 1,较对照组降低 (P <0 .0 5 )。脾脏SMC中Th1、Th2百分比、Th1/Th2比例 ,各期无明显差异。结论　DSS结肠炎是一种以肠黏膜免疫功能紊乱为主的炎症性病变。Th1优势反应可能与急性期损伤有关 ,而Th2优势反应可能在炎症的慢性化过程中发挥重要作用。     

Therapeutic effect of a hydroxynaphthoquinone fraction on dextran sulfate sodium-induced ulcerative colitis

AIM: To evaluate the therapeutic effect of hydroxynaphthoquinone mixture (HM) on dextran sulfate sodium (DSS)-induced colitis and explore the underlying mechanisms.METHODS: BALB/c mice received 3.5% DSS for 6 d to induce ulcerative colitis. Groups of mice were orally administered HM 3.5, 7 and 14 mg/kg and mesalazine 200 mg/kg per day for 7 d. During the experiment, clinical signs and body weight, stool consistency and visible fecal blood were monitored and recorded daily. A disease activity index score was calculated for each animal. At the conclusion of the experiment, the colonic histopathological lesions were evaluated. Myeloperoxidase (MPO) activity and tumor necrosis factor-α (TNF-α) levels were determined. Protein expression levels of TNF-α, nuclear factor-κB (NF-κB) p65, inhibitor of κB (IκB) and phosphorylation of IκB (p-IκB) were analyzed by Western blot analysis.RESULTS: Administration of 3.5% DSS for 6 d successfully induced acute colitis associated with soft stool, diarrhea, rectal bleeding, and colon shortening, as well as a loss of body weight. Administration of HM effectively attenuated the severity of colonic mucosa injury. For histopathological analysis, HM treatment improved histological alterations and lowered pathological scores compared with the DSS only group. This manifested as a reduction in the extent of colon injury and inflammatory cell infiltration, as well as the degree of mucosal destruction. In addition, HM at doses of 7 and 14 mg/kg significantly decreased MPO activity in colonic tissue (0.98 ± 0.22 U/g vs 1.32 ± 0.24 U/g, 0.89 ± 0.37 U/g vs 1.32 ± 0.24 U/g tissue, P < 0.05) and serum TNF-α levels (68.78 ± 7.34 ng/L vs 88.98 ± 17.79 ng/L, 64.13 ± 14.13 ng/L vs 88.98 ± 17.79 ng/L, P < 0.05). Furthermore, HM down-regulated the expression of TNF-α, NF-κB p65 and p-IκBα in colonic tissue while up-regulating IκBα protein expression. These results suggest that the significant anti-inflammatory effect of HM may be attributable to its inhibition of TNF-α production and NF-κB activation.CONCLUSION: HM had a favorable therapeutic effect on DSS-induced ulcerative colitis, supporting its further development and clinical application in inflammatory bowel disease.     

Effect of enteral nutrition on dextran sulfate sodium-induced colitis in rats

OBJECTIVE: To study the effect of enteral nutrition (EN) on dextran sulfate sodium (DSS)‐induced colitis in rats. METHODS: Eighty‐four Sprague–Dawley rats were divided into 7 groups (12 rats in each group). The blank control group was given ordinary laboratory feed and drinking water. The experimental groups received 5% DSS as drinking water for 7 days. Of the experimental groups, the model control group received ordinary laboratory feed, protein based enteral nutrition (PEN) was fed in the PEN group, while other groups received ordinary laboratory feed plus 5‐aminosalicylic acid (5‐ASA), methyl‐prednisolone, Lactobacillus or glutamine, respectively. On the 8th day, all the rats were sacrificed. Inflammatory scores were assessed from colonic mucosa. Blood culture from inferior vena cava, fecal culture and secretary immunoglobulin‐A (S‐IgA) levels from colonic contents were determined. RESULTS: Colon inflammatory scores of Lactobacillus, PEN, glutamine and drug‐treated groups were lower than that of the model control group (P < 0.01). The ratios of bacteria translocation in the EN (PEN, Lactobacillus and glutamine) groups were lower than that in the model control group (P < 0.0083). Fecal Lactobacilli in the Lactobacillus and glutamine groups were higher than that in the model control group (P < 0.05). S‐IgA levels in colonic contents of the PEN and 5‐ASA group were lower than that in the model control group (P < 0.05). CONCLUSIONS: EN is an effective therapy for treating DDS‐induced colitis. EN could alleviate damage, promote the repair of colonic epithelial cells and inhibit bacterial translocation. Lactobacillus and glutamine could also increase the Lactobacilli in colon.     

Compensatory response of colon tissue to dextran sulfate sodium-induced colitis

Depletion of goblet cells (the main mucin-producing cells in the colon) is one of the most reliable histological characteristics of ulcerative colitis, whereas a major symptom of this disease is bloody diarrhea containing a large amount of mucus. The discrepancy between these phenomena was investigated in a time-course study in rats with experimental colitis induced by treatment with oral dextran sulfate sodium (DSS) for 1, 3, or 5 days. Biochemical analysis showed a reduction in mucin content in the distal side of the colon that was proportional to the duration of DSS administration. In the proximal side of the colon, however, there was a significant increase in mucin content already on the first day of treatment with DSS. This increase in colonic mucin content continued for the 5 days of treatment. In the distal side, both sulfomucin and sialomucin decreased proportionally to the duration of DSS administration. In the proximal side, there was an increase in high iron diamine-Alcian blue-positive mucins, and confirming the proliferation of goblet cells. The proliferated glands were predominantly sialylated. Goblet cell depletion and an increase in mucin production occurred in different parts of the colon. This phenomenon may be a type of compensatory function of colon tissue in response to the localized decrease of mucin production in certain portions of the colon. (Received Sept. 7, 1998; accepted Nov. 27, 1998)     

Protective effects of panax notoginseng saponin on dextran sulfate sodium-induced colitis in rats through phosphoinositide-3-kinase protein kinase B signaling pathway inhibition

BACKGROUND Intestinal inflammation is a common digestive tract disease, which is usually treated with hormone medicines. Hormone medicines are effective to some extent, but long-term use of them may bring about many complications.AIM To explore the protective effects of panax notoginseng saponin(PNS) against dextran sulfate sodium(DSS)-induced intestinal inflammatory injury through phosphoinositide-3-kinase protein kinase B(PI3K/AKT) signaling pathway inhibition in rats.METHODS Colitis rat models were generated via DSS induction, and rats were divided into control(no modeling), DSS, DSS + PNS 50 mg/k, and DSS + PNS 100 mg/kg groups. Then, the intestinal injury, oxidative stress parameters, inflammatory indices, tight junction proteins, apoptosis, macrophage polarization, and TLR4/AKT signaling pathway in colon tissues from rats in each of the groups were detected. The PI3 K/AKT signaling pathway in the colon tissue of rats was blocked using the PI3K/AKT signaling pathway inhibitor, LY294002.RESULTS Compared with rats in the control group, rats in the DSS group showed significantly shortened colon lengths, and significantly increased disease activity indices, oxidative stress reactions and inflammatory indices, as well as significantly decreased expression of tight junction-associated proteins. In addition, the DSS group showed significantly increased apoptotic cell numbers,and showed significantly increased M1 macrophages in spleen and colon tissues.They also showed significantly decreased M2 macrophages in colon tissues, as well as activation of the PI3K/AKT signaling pathway(all P 0.05). Compared with rats in the DSS group, rats in the DSS + PNS group showed significantly lengthened colon lengths, decreased disease activity indices, and significantly alleviated oxidative stress reactions and inflammatory responses. In addition, this group showed significantly increased expression of tight junction-associated proteins, significantly decreased apoptotic cell numbers, and significantly decreased M1 macrophages in spleen and colon tissues. This group further showed significantly increased M2 macrophages in colon tissues, and significantly suppressed activation of the PI3K/AKT signaling pathway, as well as a dose dependency(all P 0.05). When the PI3K/AKT signaling pathway was inhibited, the apoptosis rate of colon tissue cells in the DSS + LY294002 group was significantly lower than that of the DSS group(P 0.05).CONCLUSION PNS can protect rats against DSS-induced intestinal inflammatory injury by inhibiting the PI3K/AKT signaling pathway, and therefore may be potentially used in the future as a drug for colitis.     

Anti-inflammatory mechanism of oxymatrine in dextran sulfate sodium-induced colitis of rats

AIM: To investigate the anti-inflammatory mechanism of oxymatrine in dextran sulfate sodium (DSS)-induced colitis of rats. METHODS: Acute colitis was induced by giving 2% DSS orally in drinking water for 8 d. Twenty-six male rats were randomized into oxymatrine-treated group (group A, 10 rats), DSS control (group B, 10 rats) and normal control (group C, 6 rats). The rats in group A were injected muscularly with oxymatrine at the dosage of 63 mg/(kg·d) from d 1 to 11 and drank 2% DSS solution from d 4 to 11. The rats in group B were treated with 0.9% saline in an equal volume as group A and drank 2% DSS solution from d 4 to 11. The rats in group C were treated with 0.9% saline as group B from d 1 to 11 and drank water normally. Diarrhea and bloody stool as well as colonic histology were observed. The levels of serum tumor necrosis factor-α(TNF-α) and interleukin-6 (IL-6) were determined by ELISA, and nuclear factor-κB (NF-κB) activity and the expression of inter-cellular adhesion molecule-1(ICAM-1) in colonic mucosa were detected by immunohistochemistry method. RESULTS: Compared with DSS contror group, the inflammatory symptoms and histological damages of colonic mucosa in oxymatrine-treated group were significantly improved, the serum levels of TNF-α, IL-6, and the expression of NF-κB, ICAM-1 in colonic mucosa were significantly reduced. CONCLUSION: The fact that oxymatrine can reduce the serum levels of TNF-α, IL-6, and the expression of NF-κB and ICAM-1 in colonic mucosa in DSS-induced colitis of rats indicates that oxymatrine may ameliorate the colonic inflammation and thus alleviate diarrhea and bloody stool.     

Conditioned secretome of adipose-derived stem cells improves dextran sulfate sodium-induced colitis in mice

BACKGROUNDInflammatory bowel diseases (IBD) is related to uncontrolled immune response. Currently, there is no successful treatment for significant improvement in IBD. Stem cells display their therapeutic effects through their repopulating capacity or secreting factors. AIMTo investigate the effects of conditioned mouse adipose-derived stem cells (mADSCs) secretome on colitis-induced mice. METHODSmADSCs were isolated from adipose tissue of C57BL/6 mice. Conditioned mADSCs secrectome was obtained by culturing of mADSCs with lipopolysaccharides (LPS, 1 μg/mL) for 24 h. Acute colitis was induced by 2% dextran sulfate sodium (DSS) drinking water for 7 d and then normal drinking water for 4 d. The mice were treated with normal culture medium (NM group), conditioned mADSCs secretome (CM group) or mADSCs (SC group). The length of colon and histopatholgy of colon tissues were evaluated. The mRNA expression levels of inflammatory cytokines in colon tissue and the serum interleukin (IL)-6 levels were determined. RESULTSThe isolated mADSCs maintained the mADSCs specific gene expression profiles during experiment. The conditioned mADSCs secretome released by the treatment of mADSCs with LPS contained mainly inflammatory chemokines, colony-stimulating factors and inflammatory cytokines. The loss of body weight and reduction in colon length were ameliorated in the CM group. The conditioned mADSCs secretome reduced the histological score in colon tissue. The expression of IL-1b and IL-6 mRNAs in colon tissues significantly inhibited in the CM group compared to SC group and NM group, respectively. The elevation of serum IL-6 levels was also ameliorated in the CM group. These results indicate that the conditioned mADSCs secretome suppressed the synthesis of inflammatory cytokines in damaged colon tissue and the elevation of serum IL-6 concentration in DSS-induced miceCONCLUSIONConditioned mADSCs secretome might play regenerative roles by the suppression of IL-6 in serum and tissue during acute colitis, and may be more effective than stem cells themselves in the regeneration of colon tissue.     

Effects of germinated barley foodstuff on dextran sulfate sodium-induced colitis in rats

Germinated barley foodstuff (GBF), derived from the aleurone and scutellum fractions of germinated barley, is rich in glutamine and low-lignified hemicellulose, and increases mucosal protein, RNA, and DNA content in the intestine when fed to normal rats. The aim of this study was to evaluate the effects of feeding GBF or germinated gramineous seeds on experimental ulcerative colitis. Sprague-Dawley rats that received 3% dextran sulfate sodium in their diets were used as an experimental colitis model. The effects of sulfasalazine, a drug used to treat inflammatory bowel disease, were compared with those of GBF. After rats had consumed diets containing GBF or various aleurone and scutellum fractions, mucosal damage; the content of mucosal protein, RNA, and DNA in the colo-rectum; and serum interleukin-8 and α₁-acid glycoprotein levels were assessed. GBF and germinated seeds more effectively prevented bloody diarrhea and mucosal damage in colitis compared with controls and rats receiving sulfasalazine, but non-germinated samples did not have a protective effect. GBF increased mucosal protein and RNA content in the colitis model. The consumption of GBF appears to prevent inflammation in a colitis model, and its effect seems to be related to the germination process. GBF and germinated seeds have the potential to serve as nutritional therapy for ulcerative colitis. (Received Mar. 17, 1997; accepted July 25, 1997)     

小鼠实验性结肠炎中骨桥蛋白的变化

目的 观察骨桥蛋白(osteopontin,OPN)在右旋葡聚糖硫酸钠(dextran sodium sulfate,DSS)诱导的小鼠结肠炎中的变化,探讨OPN在炎症性肠病(inflammatory bowel disease,IBD)发病中的作用.方法 32只雄性BALB/C小鼠随机分为对照组(予蒸馏水饮用23 d)、模型组(5%DSS饮用9 d后2.5%DSS维持2周)、柳氮磺胺吡啶(SASP)治疗组(在模型组基础上从第10天起予SASP 600 mg/kg灌胃2周)和英夫利昔治疗组(在模型组基础上在第10天予尾静脉注射英夫利昔100 mg/kg 1次).酶联免疫法检测小鼠血浆OPN浓度,逆转录聚合酶链反应和Western印迹法检测小鼠结肠组织中OPN的mRNA水平和蛋白质水平表达,免疫组化法检测OPN在结肠组织中的定位表达.结果 各组小鼠的血浆OPN浓度分别为(5.26±1.93)、(10.21±2.37)、(4.58±1.83)和(4.82±1.83)ng/ml;结肠组织中OPN mRNA表达量分别为(0.36±0.16)、(0.71±0.17)、(0.32±0.07)和(0.42±0.22);结肠组织中OPN的蛋白表达量分别为(0.44±0.10)、(0.85±0.04)、(0.61±0.11)和(0.58±0.17);结肠黏膜固有层OPN阳性细胞数分别为(46.6±10.9)、(155.5±43.8)、(73.1±6.8)和(70.6±8.3).与对照组相比,模型组血浆和结肠组织中OPN的表达明显增高(P均<0.05),SASP治疗组和英夫利昔治疗组OPN的表达均较SASP治疗组下降(P均<0.05),SASP治疗组和英夫利昔治疗组OPN的表达差异无统计学意义.结论 OPN在DSS诱导的小鼠结肠炎中表达增加,经药物治疗后表达降低.OPN促进了DSS诱导的小鼠结肠炎的发生.