Fawley Jason, Koehler Shannon, Cabrera Susan, Lam Vy, Fredrich Katherine, Hessner Martin, Salzman Nita, Gourlay David
Department of Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin; Department of Pediatrics, Children's Hospital of Wisconsin, Milwaukee, Wisconsin.
Department of Pediatrics, Children's Hospital of Wisconsin, Milwaukee, Wisconsin; Department of Surgery, Children's Hospital of Wisconsin, Milwaukee, Wisconsin.
J Surg Res. 2017 Oct;218:35-42. doi: 10.1016/j.jss.2017.03.049. Epub 2017 Apr 13.
Intestinal alkaline phosphatase (IAP) has been shown to help maintain intestinal homeostasis. Decreased expression of IAP has been linked with pediatric intestinal diseases associated with bacterial overgrowth and subsequent inflammation. We hypothesize that the absence of IAP leads to dysbiosis, with increased inflammation and permeability of the newborn intestine.
Sprague-Dawley heterozygote IAP cross-matches were bred. Pups were dam fed ad lib and euthanized at weaning. The microbiotas of terminal ileum (TI) and colon was determined by quantitative real-time polymerase chain reaction (qRT-PCR) of subphylum-specific bacterial 16S ribosomal RNA. RT-PCR was performed on TI for inflammatory cytokines. Intestinal permeability was quantified by fluorescein isothiocyanate-dextran permeability and bacterial translocation by qRT-PCR for bacterial 16S ribosomal RNA in mesenteric lymph nodes. Statistical analysis was done by chi-square analysis.
All three genotypes had similar concentrations of bacteria in the TI and colon. However, IAP knockout (IAP-KO) had significantly decreased diversity of bacterial species in their colonic stool compared with heterozygous and wild-type (WT). IAP-KO pups had a nonstatistically significant 3.9-fold increased inducible nitric oxide synthase messenger RNA expression compared with WT (IAP-KO, 3.92 ± 1.36; WT, 1.0 ± 0.27; P = 0.03). IAP-KO also had significantly increased bacterial translocation to mesenteric lymph nodes occurred in IAP-KO (IAP-KO, 7625 RFU/g ± 3469; WT, 4957 RFU/g ± 1552; P = 0.04). Furthermore, IAP-KO had increased permeability (IAP-KO, 0.297 mg/mL ± 0.2; WT, 0.189 mg/mL ± 0.15 P = 0.07), but was not statistically significant.
Deficiency of IAP in the newborn intestine is associated with dysbiosis and increased inflammation, permeability, and bacterial translocation.
肠碱性磷酸酶（IAP）已被证明有助于维持肠道内环境稳定。IAP表达降低与小儿肠道疾病相关，这些疾病与细菌过度生长及随后的炎症有关。我们推测IAP缺失会导致新生肠道菌群失调，炎症增加及通透性增强。
进行Sprague-Dawley杂合子IAP交叉配种。幼崽由母鼠自由哺乳，并在断奶时安乐死。通过亚门特异性细菌16S核糖体RNA的定量实时聚合酶链反应（qRT-PCR）测定回肠末端（TI）和结肠的微生物群。对TI进行炎症细胞因子的RT-PCR检测。通过异硫氰酸荧光素-葡聚糖通透性定量肠道通透性，并通过qRT-PCR检测肠系膜淋巴结中细菌16S核糖体RNA来定量细菌易位。采用卡方分析进行统计分析。
所有三种基因型在TI和结肠中的细菌浓度相似。然而，与杂合子和野生型（WT）相比，IAP基因敲除（IAP-KO）小鼠结肠粪便中的细菌种类多样性显著降低。与WT相比，IAP-KO幼崽诱导型一氧化氮合酶信使核糖核酸表达增加3.9倍，但差异无统计学意义（IAP-KO，3.92±1.36；WT，1.0±0.27；P=0.03）。IAP-KO小鼠中细菌易位至肠系膜淋巴结也显著增加（IAP-KO，7625 RFU/g±3469；WT，4957 RFU/g±1552；P=0.04）。此外，IAP-KO小鼠的通透性增加（IAP-KO，0.297 mg/mL±0.2；WT，0.189 mg/mL±0.15；P=0.07），但差异无统计学意义。
新生肠道中IAP缺乏与菌群失调、炎症增加、通透性增加及细菌易位有关。
