Ischemic gut contributes to the development of sepsis and organ failure in critically ill patients. Toll-like receptors (TLRs) have been reported to mediate the pathophysiology of organ damage following ischemia/reperfusion (I/R) injury. We hypothesize that LPS, a ligand for TLR4, decreases mesenteric I/R injury-induced gut damage through tumor necrosis factor α (TNF-α) signaling. First, wild-type (WT) mice were fed with oral antibiotics for 4 weeks to deplete the intestinal commensal microflora. At week 3, drinking water was supplemented with LPS (10 μg/μL) to trigger TLRs. The intestinal mucosa was harvested for TLR4 protein, caspase 3 activity, and terminal deoxynucleotide transferase labeling assay. Second, WT and Tnfrsf1a^−/− mice received 30-min ischemia and 30-min reperfusion (30I-30R) or 30I-180R of the intestine; intestinal permeability and lipid peroxidation of the intestine were examined. Third, WT and Tnfrsf1a^−/− mice were fed with oral antibiotics with or without LPS and received 30I-180R of the intestine. The intestinal mucosa was harvested for lipid peroxidation; glutathione (GSH) level; nuclear factor κB (NF-κB) and AP-1 DNA-binding activity; Bcl-w, TNF-α, and CXCR2 mRNA expression; and HSP70 protein assay. Commensal depletion increased caspase 3 activity as well as villi apoptosis and decreased TLR4 expression of the intestinal mucosa. LPS increased TLR4 expression and decreased villi apoptosis. Commensal depletion augmented 30I-180R-induced intestine permeability as well as lipid peroxidation and decreased GSH level in WT mice but not in Tnfrsf1a^−/− mice. LPS decreased 30I-180R-induced intestinal permeability as well as lipid peroxidation and increased GSH level of the intestinal mucosa in WT mice but not in Tnfrsf1a^−/− mice. Commensal depletion with 30I-180R increased NF-κB and AP-1 DNA-binding activity, HSP70 protein expression, and decreased Bcl-w and TNF-α mRNA expression of the intestinal mucosa in WT mice but not in Tnfrsf1a^−/− mice. Collectively, commensal microflora induces TLR4 expression and decreases apoptosis of the intestinal mucosa. Commensal depletion enhances I/R-induced gut damage. LPS prevents I/R-induced intestinal permeability, lipid peroxidation, and decrease in GSH level. Given that the preventive effect of LPS on I/R-induced gut damage and NF-κB activity of the intestine is abolished in Tnfrsf1a^−/− mice, we conclude that TLR ligand decreases mesenteric I/R injury-induced gut damage through TNF-α signaling.

Diabetes mellitus (DM) is characterized by increased fatality associated with the atherogenetic process. Circulating trimethylamine-N-oxide (TMAO) levels are closely associated with atherosclerosis. The flavin mono-oxygenase family (Fmo) members oxidize trimethylamine (TMA) to TMAO. The effect and the regulatory mechanism of intestinal microflora on diabetes-induced Fmo3 and intercellular adhesion molecule (ICAM) expression were examined in streptozotocin-induced diabetic mice (STZDM) and Akita mice (C57BL/6J-Ins2^Akita). STZDM-JNK1^-/- and Ins2^Akita-JNK1^-/- mice were produced and used to study the role of pJNK in the regulatory mechanisms. Diabetic mice exhibited decreased Lactobacilli growth and reactive oxygen species (ROS) production in the intestinal mucosa; increased levels of pJNK and iNOS proteins in the intestinal mucosa; increased levels of serum nitrate, IL-1β, and TNF-α expression in Kupffer cells; increased Fmo3 expression in the liver; and increased ICAM expression in the aorta. Reversal of diabetes-induced enteric dysbiosis by prebiotic (FOS) or probiotic (dead L. plantarum) treatment decreased diabetes-induced pJNK and iNOS expression in the intestine, Fmo3 expression in the liver, IL-1β expression in Kupffer cells, and ICAM expression in the aorta and liver. Ins2^Akita-JNK1^-/- and STZDM-JNK1^-/- mice demonstrated decreased levels of serum NO, IL-1β expression in Kupffer cells, Fmo3 expression in the liver, and ICAM expression in the aorta. GF mice cohoused with DM mice demonstrated an increase in ICAM expression in the liver. In conclusion, diabetes induced the expression of both Fmo3 and ICAM expression and possible vascular impairment through enteric dysbiosis. Diabetes-induced Fmo3 and ICAM expression could be reversed by pJNK inhibition or by correcting enteric dysbiosis.

Free sensate thoracodorsal artery perforator flaps that include the posterior divisions of the lateral cutaneous branches of the intercostal nerves have been described. The authors used preoperative color Doppler sonography to identify the nerves and demonstrate its clinical value. Fourteen free sensate thoracodorsal artery perforator flaps were collected. Preoperative color Doppler sonography was used to identify the locations of thoracodorsal artery perforators and the courses of the posterior divisions of the lateral cutaneous branches of the intercostal neurovascular bundles. These posterior divisions were preserved on flaps and classified into three types. Type A and B nerves sprouted cutaneous perforating fascicles over the lateral region of the latissimus dorsi muscle. Type C nerves went through the region without any dominant perforating fascicle. Twenty-one nerves were mapped, and 24 were found during surgery. The sensitivity of preoperative color Doppler sonography was 87.5 percent. Of the 24 nerves, nine were type A (37.5 percent), 12 were type B (50 percent), and three were type C (12.5 percent). Ten of the 14 patients (sensate group) showed better tactile recovery at both the center and the periphery of flap than the other 10 patients who underwent reconstruction with nonsensate flaps. Preoperative color Doppler sonography is an indispensable tool for sensate thoracodorsal artery perforator flaps in locating the perforators and mapping the posterior divisions of the lateral cutaneous branches of the intercostal nerves. The information can be used to design and harvest sensate thoracodorsal artery perforator flaps, which are associated with earlier and better tactile recovery.