Objective To investigate the effect of bifidobacterial adhesin (BA) on nuclear factor of κB (NF-κB) and cytokines of intestinal mucosa of stressed rats.Methods Forty-eight rats were divided into stress group (n =24) and BA group (n =24) using the stochastic indicator method.After the stressed rat models were established withfettering as the stress condition,the experiment lasted 8 days.Both groups were given enteral nutrition (EN) with heat 125.4 kJ/(kg · d) and nitrogen 0.2 g/(kg · d).The BA group was fed with EN plus 5 mg/ (kg · d) bifidobacterial adhesin,and the stress group was fed with EN plus equivalent volume of normal saline [5 mg/ (kg · d)].The levels of NF-κB,interleukin-10 (IL-10),tumor necrosis factor (TNF-α),and interferon-γ (IFN-γ) were measured in both groups before modeling,after modeling,on the 3rd intervention day,and on the 8th intervention day.The changes in the morphology of intestinal mucosal were observed by transmission electron microscopy.Results (1) Expression of NF-κB:The positive expression rate of NF-κB in the intestinal mucosa was 0,79.2％,63.5％,and 66.7％ in the control group and 0,68.4％,55.7％,and 45.8％ in the BA group before modeling,after modeling,on the 3rd intervention day,and on the 8th intervention day.The expressions of NF-κB in both groups significantly increased after the modeling (both P =0.000).Even on the 3rd and 8th intervention days,the positive expression rates of NF-κB in the intestinal mucosa were still significantly higher than the pre-modeling level (both P =0.000).Compared with the levels after modeling and in the control group,the expression of NF-κB in the intestinal mucosa in the BA group on the 8th intervention day was significantly down-regulated (P =0.015,P =0.021).(2) Quantitative expressions of TNF-α and IFN-γ:Compared with the pre-modeling levels,the intestinal mncosa levels of TNF-α [stressed group:(154.63 ± 17.52) pg/g,(198.72 ±26.59) pg/g; BA group:(154.63 ±17.52) pg/g,(201.45 ±28.16) pg/g],IFN-γ [stressed group:(39.47 ±5.76) pg/g,(55.32 ±5.93) pg/g; BA group:(39.47 ± 5.76),(60.75 ± 7.68) pg/g] and the plasma levels of TNF-α [stressed group:(17.35±2.62) pg/g,(30.56±4.85) ng/L; BA group:(83.31 ±9.78) pg/g,(114.82±13.78) ng/L] and IFN-γ [stressed group:(17.35 ±2.62) pg/g,(28.73 ±4.17) ng/L; BA group:(17.35 ± 2.62) pg/g,(30.56 ± 4.85) ng/L] significantl increased (all P ＜ 0.05).On the 3rd and 8th intervention day,the intestinal mucosa levels of IFN-γ [(58.16 ± 7.38) pg/g,(56.37 ± 7.29) pg/g] and TNF-α [(215.76 ±31.54) pg/g and (211.83 ±33.61) pg/g] and plasma levels of IFN-γ [(29.35 ±4.76) ng/L,(30.25±3.67) ng/L] andTNF-α [(125.71 ±17.38) ng/L,(141.26±19.65) ng/L] in the stressed group were significantly higher than the pre-modeling levels (all P ＜ 0.05).On the 3rd and 8th intervention day,the intestinal mucosa levels of IFN-γ [(165.43 ± 24.58) pg/g,(171.57 ± 26.87) pg/g]and IFN-γ [(42.35 ±4.92) pg/g,(40.58 ±4.65) pg/g] and the plasma levels of TNF-α [(103.96 ±13.68) ng/L,(94.53±12.66) ng/L] and IFN-γ [(20.78±2.84) ng/L,(19.65±2.45) ng/L] in the BA group were significantly lower than the post-modeling levels (all P ＜ 0.05),whereas those of IL (intestinal mucosa:(62.82 ±8.34) pg/g,(75.16 ±9.65) pg/g; plasma:(43.32 ±5.28) ng/L,(55.64 ±6.87) ng/L] were significantly higher than the post-modeling levels (all P ＜ 0.05).Compared with the stressed group,the intestinal mucosa levels of TNF-α and IFN-γand plasma levels of IFN-γ and TNF-α significantly decreased while the IL-10 level significantly increased (all P ＜0.05) in the BA group.(3) Histomorphology showed that,compared that the ileal mucosal villi and crypt structure were recovered in the BA group on the 8th intervention day.Compared with the post-modeling conditions,the ileal mucosal villi and crypt structure were damaged in the stressed group,showing edema of the lamina propria,in which inflammatory cell infiltration was observed.Conclusions BA is helpful for the repair of the intestinal mucosa injury after stress by regulating the release of inflammatory mediators and cytokines of intestinal mucosa.%目的 研究双歧杆菌黏附素对大鼠肠黏膜核因子-κB (NF-κB)和细胞因子的影响.方法 将48只实验大鼠按随机数字表法分成应激组、黏附素组,每组24只,以束缚为应激条件建立应激模型,造模后持续实验8d.两组大鼠肠内营养供给量为热量125.4 kJ/(kg·d),氮量0.2 g/(kg·d).黏附素组大鼠喂养肠内营养加双歧杆菌黏附素5 mg/(kg·d),应激组大鼠喂养肠内营养加等量的生理盐水5 mg/(kg·d).测定造模前、造模后、实验第3天和第8天两组大鼠肠黏膜NF-κB定性表达结果以及肠黏膜和血浆NF-κB、白细胞介素-10 (IL-10)、肿瘤坏死因子-α(TNF-α)、干扰素-γ(IFN-γ)定量表达结果.透射电镜下观察小肠黏膜形态学变化.结果 (1) NF-κB的表达:造模前、造模后、实验第3天、实验第8天应激组肠黏膜NF-κB的阳性表达率分别为O、79.2％ (19/24)、63.5％(15/24)、66.7％ (16/24),黏附素组分别为O、68.4％ (17/24)、55.7％ (14/24)、45.8％ (11/24)；与造模前比较,造模后两组肠黏膜NF-κB表达明显上调(均P=0.000),实验第3天和实验第8天,两组肠黏膜细胞核NF-κB表达阳性率仍明显高于造模前(均P=0.000),与造模后和应激组比较,实验第8天黏附素组肠黏膜NF-κB表达明显下调(P值分别为0.015、0.021).(2) TNF-α、IFN-γ与IL-10的定量表达:与造模前比较,造模后应激组与黏附素组大鼠肠黏膜TNF-α[应激组:(154.63±17.52)、(198.72±26.59) pg/g,黏附素组:(154.63±17.52)、(201.45±28.16) pg/g]、IFN-γ[应激组:(39.47±5.76)、(55.32±5.93) pg/g,黏附素组:(39.47±5.76)、(60.75±7.68)pg/g]浓度量和血浆TNF-α[应激组:(83.31±9.78)、(117.64±15.37) ng/L,黏附素组:(83.31±9.78)、(114.82±13.78) ng/L]、IFN-γ[(应激组:(17.35±2.62)、(28.73±4.17) ng/L,黏附素组:(17.35±2.62)、(30.56±4.85) ng/L]浓度明显升高(均P＜0.05)；实验第3天和第8天,应激组大鼠肠黏膜IFN-γ[(58.16±7.38)、(56.37 ±7.29) pg/g]、TNF-α[(215.76±31.54)、(211.83±33.61) pg/g]浓度和血浆IFN-γ[(29.35±4.76)、(30.25±3.67) ng/L]、TNF-α浓度[(125.71±17.38)、(141.26±19.65) ng/L]明显高于造模前(P均＜0.05)；实验第3天和第8天,黏附素组大鼠肠黏膜TNF-α[(165.43±24.58)、(171.57±26.87) pg/g]、IFN-γ[(42.35±4.92)、(40.58±4.65) pg/g]和血浆TNF-α[(103.96±13.68)、(94.53±12.66) ng/L]、IFN-γ[(20.78±2.84)、(19.65±2.45) ng/L]水平明显低于造模后(P均＜0.05),而IL-10[肠黏膜:(62.82±8.34)、(75.16±9.65) pg/g,血浆:(43.32±5.28)、(55.64±6.87) ng/L]水平明显高于造模后(P均＜0.05)；与应激组比较,实验第3天和第8天,黏附素组大鼠肠黏膜TNF-α、IFN-γ和血浆IFN-γ、TNF-tα水平明显降低(P均＜0.05),而IL-10水平明显升高(P均＜0.05).(3)组织形态学观察:实验第8天,在电镜下可见黏附素组较造模后和应激组回肠绒毛、隐窝结构显著恢复.应激组较造模后肠黏膜绒毛、隐窝结构有一定程度的损害,固有膜水肿,膜内有炎性细胞浸润.结论 双歧杆菌黏附素通过调节肠黏膜炎性递质和细胞因子释放,对应激后肠黏膜损伤修复有一定作用.
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