After 48 hours, CD169\cell numbers were determined in the spleen by flow cytometry (n = 4\6)

After 48 hours, CD169\cell numbers were determined in the spleen by flow cytometry (n = 4\6). liver regeneration, by inducing key signaling pathways important for liver regeneration. Liver disease is a global health problem with millions of patients worldwide suffering from infections, toxic liver damage, and hepatocellular carcinoma. Liver tissue has an extraordinary potential to regenerate, an effect already described in Greek mythology. Since then, several key molecular pathways have been discovered to play important roles during liver regeneration, including nuclear factor kappa B, signal transducer and activator of transcription 3 (STAT3), and extracellular signalCregulated kinase (Erk).1 Following Vigabatrin 70% reduction of liver mass through partial hepatectomy (PHx), tumor necrosis factor (TNF) is rapidly produced, and TNF receptor 1 (TNFR1) signaling is required to induce liver regeneration.2 Furthermore, the TNF superfamily members lymphotoxin (Lt) alpha and beta play a critical role during liver regeneration.3, 4 Consistently, mice deficient for both TNFRp55 and Lt receptor (LtR) show delayed hepatocyte proliferation and impaired survival following PHx.5 Furthermore, a marked increase in interleukin\6 (IL\6) concentrations in the serum can be detected following loss of liver mass, and IL\6\deficient mice show delayed liver regeneration following PHx.6, 7, 8 Consistently, treatment with combined IL\6 and soluble IL\6 receptor (IL\6R) can improve liver regeneration and induce rapid hepatocyte proliferation.6, 9 Moreover, epidermal growth factor receptor (EGFR) ligands including transforming growth factor alpha (TGF\) and amphiregulin are able to induce hepatocyte proliferation (diphtheria toxin [DT] receptor) mice have been described and were kept on a C57Bl/6 background.18, 24, 25 Laparotomy was performed predominantly on male mice at 10\14 weeks of age using isoflurane inhalation narcosis, as described.26 For PHx the left lateral and the left and right median liver lobes together with the gallbladder were excised subsequent to a one\step ligature using a 5\0 suture tie (Ethicon, Somerville, NJ).5 Sham operations were performed in an identical manner without ligating and removing liver lobes. For splenectomy, the splenic artery and vein were Vigabatrin ligated with a single\knot 5\0 suture at the same time as PHx or otherwise indicated in the physique legends. Next, connective tissue and spleen were removed. After irrigating the abdomen with 0.9% NaCl, both abdominal layers were closed with a running 5\0 suture (Ethicon).26 Directly after surgery and 24 and 48 hours post\PHx mice received 5 mg/kg carprofen (Rimadyl; Pfizer, Wrselen, Germany). As expected, Rabbit polyclonal to THIC splenectomized animals did not show any sign of pathology (Fig. ?(Fig.1A).1A). Mice exhibiting severe disease symptoms were sacrificed and considered as dead. CD169+ cells in the animals were depleted by injecting two doses of 100 ng DT (Sigma) before the PHx. Wild\type (WT; C57Bl/6) mice were used as controls. Mice were 10\14 weeks old. For blood and tissue collection mice were anesthetized (100 mg/kg ketamine, 10 mg/kg xylazine; Vtoquinol GmbH, Ravensburg, Germany), weighed, and bled through the vena cava inferior; and serum was collected. The liver and spleen were Vigabatrin removed, rinsed in phosphate\buffered saline (PBS), and weighed to calculate the liver weight to body weight ratio and the spleen weight. Liver and spleen samples were stored at C80 C for histology and RNA and protein extraction. Open in a separate window Physique 1 Decreased liver regeneration in splenectomized and B cellCdeficient mice following PHx. (A) Survival of splenectomized, 70% PHx, and splenectomized mice followed by PHx (PHx+S) was monitored (n = 14\19). (B) The liver weight/body weight ratio was decided at the indicated time points in WT sham\operated mice and splenectomized mice (left panel) and in PHx WT mice and splenectomized mice (PHx+S) (right panel) (n = 3\5). (C,D).