AAP PaperToll-like receptor 4 is protective against neonatal murine ischemia-reperfusion intestinal injury
Section snippets
Mice
Adult C57BL/6 WT, B6.TLR2−/−, B6.TLR4−/−, and B6.TLR2−/−4−/− mice were used for breeding to obtain 2-week-old pups for the study. The B6.TLR2−/− and B6.TLR4−/− were provided as gift from Drs Shizuo Akira at Osaka University Japan and Doug Golenbock at the University of Massachusetts. The mice with combined TLR2 and 4 deficiencies were bred at our facility and screened by polymerase chain reaction (PCR) using the primer sequences: for TLR2, GGTTCAAGCCCCTTTCTTCTTTA (forward),
Microbial reduction using antibiotics
To assess the degree of microbial reduction in the mice receiving antibiotic therapy, MR and SPF 2-week-old mice were analyzed for the presence of bacteria using amplification of 16s rRNA. After DNA extraction and PCR with conserved bacterial 16s rRNA primers, a DGGE analysis revealed a relatively diverse microbial population in the SPF feces (Fig. 1, lanes D and E) compared to MR mice (Fig. 1, lanes A-C). A band denoting a single bacterial species was observed in the MR mice (Fig. 1, arrow).
Discussion
Necrotizing enterocolitis continues to be a leading cause of morbidity and mortality in VLBW infants. Despite advances with other illnesses of VLBW infants, the rate of NEC remains unchanged for the last 2 decades [12]. Lack of insight into the mechanism of NEC has made development of treatments aimed at preventing the disease difficult. Although the pathogenesis in NEC is likely multifactorial, key factors that have been implicated in NEC include intestinal hypoperfusion [13], abnormal
Acknowledgments
We would like to thank Jamie McNaught and the Cell and Molecular Pathology Core of the Digestive Disease Developmental Center at UAB for assistance with the histology, Peggie McKie-Bell for animal husbandry assistance, and Randy Bullock for his assistance with the RT-PCR and PCR-DGGE experiments.
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The microbiota protects against ischemia/reperfusion-induced intestinal injury through nucleotide-binding oligomerization domain-containing protein 2 (NOD2) signaling
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Inflammatory Signaling in Necrotizing Enterocolitis
2013, Clinics in PerinatologyCitation Excerpt :TLR4 is the receptor for endotoxin. Although a study found that TLR4 was protective in ischemia/reperfusion injury in neonatal mice,37 there are many pieces of evidence that suggest that TLR4 has an injurious role in NEC: (1) intestinal TLR4 gene expression is increased in animals exposed to formula feeding and cold asphyxia stress during experimental NEC, whereas it is normally downregulated in dam-fed animals during the first 72 hours of life38; and (2) TLR4-deficient mice are protected against NEC.38,39 TLR4 activation in IECs has been found to delay mucosal repair by inducing HMGB1 signaling, which increases stress fibers and focal adhesions40 and reduces enterocyte proliferation by inhibiting beta-catenin signaling.41
Probiotic bacteria induce maturation of intestinal claudin 3 expression and barrier function
2012, American Journal of Pathology
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This work was supported in part by the NIH grants R01 DK059911, P01 DK071176, K08 HD46506, and the University of Alabama at Birmingham Digestive Diseases Research Development Center grant P30 DK064400. PT received partial support from the UAB Dixon Fellowship. Aspects of this project were conducted in biomedical research space that was constructed with funds supported in part by the NIH grant C06RR020136.