Division of Digestive Disease, Xiangya Second Hospital, Central South University, Changsha 410011, Hunan Province, China.
World J Gastroenterol. 2012 May 21;18(19):2344-56. doi: 10.3748/wjg.v18.i19.2344.
To investigate the role of Lactobacillus crispatus (L. crispatus) strain China Center for Type Culture Collection (CCTCC) M206119 in intestinal inflammation.
Forty 8-wk-old Balb/c mice (20 ± 2 g) were divided into four groups of 10 mice each. Three groups that had received dextran sulfate sodium (DSS) were administered normal saline, sulfasalazine or CCTCC M206119 strain, and the fourth group received none of these. We assessed the severity of colitis using a disease activity index, measured the colon length and weight, collected stools and mesenteric lymph nodes for bacterial microflora analysis. One centimeter of the proximal colon, middle colon and distal colon were collected and fixed in 10% buffered formalin, dehydrated in ethanol, and embedded in paraffin. Interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α expression was detected using reverse transcription polymerase chain reaction. Protective factors zonula occludens (ZO)-1 and β-defensin 2 were detected by immunoblotting. The features of CCTCC M206119 strain were identified based on morphology, biochemical profile, and 16S RNA sequencing.
DSS-colitis animals treated with CCTCC M206119 had markedly more severe disease, with greater weight loss, diarrhea, fecal bleeding, and shortened colon length. In addition, the CCTCC-M206119-treated group had comparatively higher histological scores and more neutrophil infiltration than the controls. Expression of protective factors ZO-1 and β-defensin 2 was downregulated due to destruction of the mucosal barrier after CCTCC M206119 strain treatment. An in vitro assay demonstrated that CCTCC M206119 strain increased the nuclear translocation of nuclear factor-κB in epithelial cells. Intestinal proinflammatory or anti-inflammatory cytokine responses were evaluated. Proinflammatory colonic cytokine (IL-1β, IL-6 and TNF-α) levels were clearly increased in CCTCC-M206119-treated animals, whereas anti-inflammatory colonic cytokine (IL-10) level was lowered compared with saline or 5-aminosalicylic-acid-treated DSS-colitis mice. Next, CCTCC M206119 strain was characterized as L. crispatus by microscopic morphology, biochemical tests and 16S rRNA gene level.
Not all lactobacilli are beneficial for intestinal inflammation, and L. crispatus CCTCC M206119 strain is involved in exacerbation of intestinal inflammation in DSS-colitis mice.
研究詹氏乳杆菌（Lactobacillus crispatus）CCTCC M206119 株在肠道炎症中的作用。
将 40 只 8 周龄 Balb/c 小鼠（20±2g）分为 4 组，每组 10 只。3 组给予葡聚糖硫酸钠（DSS），分别给予生理盐水、柳氮磺胺吡啶或 CCTCC M206119 株，第 4 组不给予任何处理。使用疾病活动指数评估结肠炎的严重程度，测量结肠长度和重量，收集粪便和肠系膜淋巴结进行细菌菌群分析。收集近端结肠、中段结肠和远端结肠 1cm 长的组织，固定在 10%缓冲福尔马林中，用乙醇进行脱水，然后包埋在石蜡中。使用逆转录聚合酶链反应检测白细胞介素（IL）-1β、IL-6 和肿瘤坏死因子（TNF）-α的表达。通过免疫印迹检测保护性因子紧密连接蛋白（ZO）-1 和β-防御素 2 的表达。根据形态、生化特征和 16S RNA 测序鉴定 CCTCC M206119 株的特征。
用 CCTCC M206119 株处理的 DSS 结肠炎动物的疾病明显更严重，体重下降、腹泻、粪便出血和结肠缩短更为明显。此外，与对照组相比，CCTCC-M206119 处理组的组织学评分和中性粒细胞浸润更高。CCTCC M206119 株处理后，由于黏膜屏障破坏，保护性因子 ZO-1 和β-防御素 2 的表达下调。体外试验表明，CCTCC M206119 株增加了上皮细胞中核因子-κB 的核转位。评估肠道促炎或抗炎细胞因子反应。CCTCC-M206119 处理动物的结肠促炎细胞因子（IL-1β、IL-6 和 TNF-α）水平明显升高，而抗炎性结肠细胞因子（IL-10）水平与生理盐水或 5-氨基水杨酸处理的 DSS 结肠炎小鼠相比降低。接下来，通过显微镜形态学、生化试验和 16S rRNA 基因水平将 CCTCC M206119 株鉴定为詹氏乳杆菌。
并非所有乳杆菌都有益于肠道炎症，L. crispatus CCTCC M206119 株参与了 DSS 结肠炎小鼠肠道炎症的加重。
