Donor plasmacytoid dendritic cells modulate effector and regulatory T cell responses in mouse spontaneous liver transplant tolerance.

We assessed the role of donor liver non-conventional plasmacytoid dendritic cells (pDCs) in spontaneous liver transplant tolerance in a fully MHC-mismatched (C57BL/6 (H2b ) to C3H (H2k )) mouse model. Compared with spleen pDCs, liver pDCs expressed higher levels of DNAX-activating protein of 12 kDa and its co-receptor, triggering receptor expressed by myeloid cells 2, and higher ratios of programed death ligand-1 (PD-L1):costimulatory CD80/CD86 in the steady state and after Toll-like receptor 9 ligation. Moreover, liver pDCs potently suppressed allogeneic CD4+ and CD8+ T cell proliferative responses. Survival of pDC-depleted livers was much poorer (median survival time: 25 days) than that of either untreated donor livers or pDC-depleted syngeneic donor livers that survived indefinitely. Numbers of forkhead box p3 (FoxP3)+ regulatory T cells in grafts and mesenteric lymph nodes of mice given pDC-depleted allogeneic livers were reduced significantly compared with those in recipients of untreated livers. Graft-infiltrating CD8+ T cells with an exhausted phenotype (programed cell death protein 1+ , T cell immunoglobulin and mucin domain-containing protein 3+ ) were also reduced in recipients of pDC-depleted livers. PD1-PD-L1 pathway blockade reversed the reduction in exhausted T cells. These novel observations link immunoregulatory functions of liver interstitial pDCs, alloreactive T cell exhaustion, and spontaneous liver transplant tolerance.

Graft-infiltrating PD-L1hi cross-dressed dendritic cells regulate antidonor T cell responses in mouse liver transplant tolerance.

Although a key role of cross-dressing has been established in immunity to viral infection and more recently in the instigation of transplant rejection, its role in tolerance is unclear. We investigated the role of intragraft dendritic cells (DCs) and cross-dressing in mouse major histocompatibility complex (MHC)-mismatched liver transplant tolerance that occurs without therapeutic immunosuppression. Although donor interstitial DCs diminished rapidly after transplantation, they were replaced in the liver by host DCs that peaked on postoperative day (POD) 7 and persisted indefinitely. Approximately 60% of these recipient DCs displayed donor MHC class I, indicating cross-dressing. By contrast, only a very minor fraction (0%-2%) of cross-dressed DCs (CD-DCs) was evident in the spleen. CD-DCs sorted from liver grafts expressed much higher levels of T cell inhibitory programed death ligand 1 (PD-L1) and high levels of interleukin-10 compared with non-CD-DCs (nCD-DCs) isolated from the graft. Concomitantly, high incidences of programed death protein 1 (PD-1)hi T cell immunoglobulin and mucin domain containing 3 (TIM-3)+ exhausted graft-infiltrating CD8+ T cells were observed. Unlike nCD-DCs, the CD-DCs failed to stimulate proliferation of allogeneic T cells but markedly suppressed antidonor host T cell proliferation. CD-DCs were much less evident in allografts from DNAX-activating protein of 12 kDa (DAP12)-/- donors that were rejected acutely. CONCLUSION: These findings suggest that graft-infiltrating PD-L1hi CD-DCs may play a key role in the regulation of alloimmunity and in the induction of liver transplant tolerance. (Hepatology 2018;67:1499-1515).

IL-23 mediates murine liver transplantation ischemia-reperfusion injury via IFN-γ/IRF-1 pathway.

Interleukin-23 (IL-23) is a proinflammatory cytokine initially studied in autoimmune disease that has been more recently linked to innate immunity. We observed that the expression of IL-23 is upregulated during hypoxia in a hepatocyte and nonparenchymal cell (NPC) coculture system, as well as during ischemia-reperfusion (I/R) injury in the liver. Interferon regulatory factor-1 (IRF-1) is a transcription factor that induces expression of multiple inflammatory cytokines and has been shown to play a critical role in liver I/R injury. We observed that IL-23 signaling induces not only the IL-17/chemokine (C-X-C motif) ligand 2 (CXCL2) pathway but also the IFN-γ/IRF-1 pathway. Quantification of cytokine genes revealed increased liver expression of IL-17a, CXCL2, and IRF-1 messenger RNA during liver transplantation. Recombinant IL-23 treated hepatocytes, and NPC coculture led to IL-17, CXCL2, IFN-γ, and IRF-1 expression. With anti-IL-17 and anti-Ly6G antibody neutralization, neutrophil recruitment and IFN-γ production were decreased during warm I/R injury. Overexpression of IL-23 in vivo through use of an adenovirus vector also led to expression of IL-17, CXCL2, IFN-γ, and IRF-1. The increased expression of IL-23 also led to increased apoptosis in the liver. By neutralization of IL-23 through use of an anti-IL-23p19 antibody, we were able to attenuate liver damage in a wild-type but not a natural killer T (NKT) cell-deficient mouse. This suggests that IL-23 signaling shares a common pathway with NKT cells. In conclusion, IL-23 is induced early by I/R in the liver. Its signaling leads to activation of the IL-17/CXCL2 and IFN-γ/IRF-1 pathways, resulting in increased apoptosis and necrosis. NEW & NOTEWORTHY IL-23 is expressed early during cold ischemia-reperfusion (I/R), and this expression is associated with expression of IL-17 and chemokine (C-X-C motif) ligand 2. Neutralization of IL-23 during cold I/R can significantly reduce liver damage as well as decrease cytokine production and neutrophil infiltration in the liver. IL-23 appears to activate IFN-γ production in natural killer T cells within the liver which, in turn, activates interferon regulatory factor-1, a known inflammatory transcription factor during I/R injury.

Herpes simplex viral-vector design for efficient transduction of nonneuronal cells without cytotoxicity.

The design of highly defective herpes simplex virus (HSV) vectors for transgene expression in nonneuronal cells in the absence of toxic viral-gene activity has been elusive. Here, we report that elements of the latency locus protect a nonviral promoter against silencing in primary human cells in the absence of any viral-gene expression. We identified a CTCF motif cluster 5' to the latency promoter and a known long-term regulatory region as important elements for vigorous transgene expression from a vector that is functionally deleted for all five immediate-early genes and the 15-kb internal repeat region. We inserted a 16.5-kb expression cassette for full-length mouse dystrophin and report robust and durable expression in dystrophin-deficient muscle cells in vitro. Given the broad cell tropism of HSV, our design provides a nontoxic vector that can accommodate large transgene constructs for transduction of a wide variety of cells without vector integration, thereby filling an important void in the current arsenal of gene-therapy vectors.

Bile Duct Ligation Induces ATZ Globule Clearance in a Mouse Model of α-1 Antitrypsin Deficiency.

α-1 Antitrypsin deficiency (A1ATD) can progress to cirrhosis and hepatocellular carcinoma; however, not all patients are susceptible to severe liver disease. In A1ATD, a toxic gain-of-function mutation generates insoluble ATZ "globules" in hepatocytes, overwhelming protein clearance mechanisms. The relationship between bile acids and hepatocytic autophagy is less clear but may involve altered gene expression pathways. Based on previous findings that bile duct ligation (BDL) induces autophagy, we hypothesized that retained bile acids may have hepatoprotective effects in PiZZ transgenic mice, which model A1ATD. We performed BDL and partial BDL (pBDL) in PiZZ mice, followed by analysis of liver tissues. PiZZ liver subjected to BDL showed up to 50% clearance of ATZ globules, with increased expression of autophagy proteins. Analysis of transcription factors revealed significant changes. Surprisingly nuclear TFEB, a master regulator of autophagy, remained unchanged. pBDL confirmed that ATZ globule clearance was induced by localized stimuli rather than diet or systemic effects. Several genes involved in bile metabolism were overexpressed in globule-devoid hepatocytes, compared to globule-containing cells. Retained bile acids led to a dramatic reduction of ATZ globules, with enhanced hepatocyte regeneration and autophagy. These findings support investigation of synthetic bile acids as potential autophagy-enhancing agents.

IRF-1 promotes liver transplant ischemia/reperfusion injury via hepatocyte IL-15/IL-15Rα production.

Ischemia and reperfusion (I/R) injury following liver transplantation (LTx) is an important problem that significantly impacts clinical outcomes. IFN regulatory factor-1 (IRF-1) is a nuclear transcription factor that plays a critical role in liver injury. Our objective was to determine the immunomodulatory role of IRF-1 during I/R injury following allogeneic LTx. IRF-1 was induced in liver grafts immediately after reperfusion in both human and mouse LTx. IRF-1 contributed significantly to I/R injury because IRF-1-knockout (KO) grafts displayed much less damage as assessed by serum alanine aminotransferase and histology. In vitro, IRF-1 regulated both constitutive and induced expression of IL-15, as well as IL-15Rα mRNA expression in murine hepatocytes and liver dendritic cells. Specific knockdown of IRF-1 in human primary hepatocytes gave similar results. In addition, we identified hepatocytes as the major producer of soluble IL-15/IL-15Rα complexes in the liver. IRF-1-KO livers had significantly reduced NK, NKT, and CD8(+) T cell numbers, whereas rIL-15/IL-15Rα restored these immune cells, augmented cytotoxic effector molecules, promoted systemic inflammatory responses, and exacerbated liver injury in IRF-1-KO graft recipients. These results indicate that IRF-1 promotes LTx I/R injury via hepatocyte IL-15/IL-15Rα production and suggest that targeting IRF-1 and IL-15/IL-15Rα may be effective in reducing I/R injury associated with LTx.

Liver transplantation in the mouse: Insights into liver immunobiology, tissue injury, and allograft tolerance.

The surgically demanding mouse orthotopic liver transplant model was first described in 1991. It has proved to be a powerful research tool for the investigation of liver biology, tissue injury, the regulation of alloimmunity and tolerance induction, and the pathogenesis of specific liver diseases. Liver transplantation in mice has unique advantages over transplantation of the liver in larger species, such as the rat or pig, because the mouse genome is well characterized and there is much greater availability of both genetically modified animals and research reagents. Liver transplant experiments using various transgenic or gene knockout mice have provided valuable mechanistic insights into the immunobiology and pathobiology of the liver and the regulation of graft rejection and tolerance over the past 25 years. The molecular pathways identified in the regulation of tissue injury and promotion of liver transplant tolerance provide new potential targets for therapeutic intervention to control adverse inflammatory responses/immune-mediated events in the hepatic environment and systemically. In conclusion, orthotopic liver transplantation in the mouse is a valuable model for gaining improved insights into liver biology, immunopathology, and allograft tolerance that may result in therapeutic innovation in the liver and in the treatment of other diseases.

Contribution of alloantigens to hepatic ischemia/reperfusion injury: Roles of natural killer cells and innate immune recognition of nonself.

Hepatic ischemia/reperfusion injury (IRI) remains a major clinical problem and involves the innate immune system's recognition of "nonself." Considering the efficient nonself recognition by natural killer (NK) cells, we hypothesize in this study that hepatic IRI associated with liver transplantation (LT) could be augmented in allogeneic rather than in syngeneic (Syn) grafts due to alloantigen recognition by innate immune cells, especially by NK cells. Using green fluorescent protein (GFP)/Sprague-Dawley rats, we tested our hypothesis in a rat LT model with 18 hours of cold storage in University of Wisconsin solution. Hepatic IRI was significantly augmented in allografts with higher alanine transaminase levels, increased necrosis, and vigorous proinflammatory mediator up-regulation compared to Syn grafts. Injury increased in allografts associated with augmented GFP+ host leukocyte infiltration due to significantly increased host CD11b/c+ and RP-1(+) neutrophil recruitment. A large number of liver-resident (donor) mature CD11b/c+ NK cells quickly diminished from allografts, but not from Syn grafts. Depletion of mature NK cells from liver grafts with anti-asialo monosialotetrahexosylganglioside significantly improved hepatic IRI and reduced neutrophil infiltration and proinflammatory mediators. In conclusion, early innate immune responses were more significantly enhanced in allografts than in Syn grafts during hepatic IRI, in part through NK cell recognition of "missing self."

Plasmacytoid dendritic cell-derived IFN-α promotes murine liver ischemia/reperfusion injury by induction of hepatocyte IRF-1.

UNLABELLED: Plasmacytoid dendritic cells (pDC) constitute the body's principal source of type I interferon (IFN) and are comparatively abundant in the liver. Among various cytokines implicated in liver ischemia and reperfusion (I/R) injury, type I IFNs have been described recently as playing an essential role in its pathogenesis. Moreover, type I IFNs have been shown to up-regulate hepatocyte expression of IFN regulatory factor 1 (IRF-1), a key transcription factor that regulates apoptosis and induces liver damage after I/R. Our aim was to ascertain the capacity of IFN-α released by liver pDC to induce liver damage through hepatic IRF-1 up-regulation after I/R injury. Our findings show that liver pDC mature and produce IFN-α in response to liver I/R. Liver pDC isolated after I/R induced elevated levels of IRF-1 production by hepatocytes compared with liver pDC isolated from sham-operated mice. Notably, hepatic IRF-1 expression was reduced significantly by neutralizing IFN-α. In vivo, IFN-α neutralization protected the liver from I/R injury by reducing hepatocyte apoptosis. This was associated with impaired expression of IRF-1 and proapoptotic molecules such as Fas ligand, its receptor (Fas) and death receptor 5, which are regulated by IRF-1. Furthermore, pDC-depleted mice failed to up-regulate hepatic IFN-α and displayed less liver injury associated with reduced levels of hepatic interleukin (IL)-6, tumor necrosis factor-α, and hepatocyte apoptosis after I/R compared with controls. CONCLUSION: these data support the hypothesis that IFN-α derived from liver pDC plays a key role in the pathogenesis of liver I/R injury by enhancing apoptosis as a consequence of induction of hepatocyte IRF-1 expression.

Gut bacteria drive Kupffer cell expansion via MAMP-mediated ICAM-1 induction on sinusoidal endothelium and influence preservation-reperfusion injury after orthotopic liver transplantation.

Bacteria in the gut microbiome shed microbial-associated molecule patterns (MAMPs) into the portal venous circulation, where they augment various aspects of systemic immunity via low-level stimulation. Because the liver is immediately downstream of the intestines, we proposed that gut-derived MAMPs shape liver immunity and affect Kupffer cell (KC) phenotype. Germ-free (GF), antibiotic-treated (AVMN), and conventional (CL) mice were used to study KC development, function, and response to the significant stress of cold storage, reperfusion, and orthotopic transplantation. We found that a cocktail of physiologically active MAMPs translocate into the portal circulation, with flagellin (Toll-like receptor 5 ligand) being the most plentiful and capable of promoting hepatic monocyte influx in GF mice. In MAMP-deficient GF or AVMN livers, KCs are lower in numbers, have higher phagocytic activity, and have lower major histocompatibility complex II expression. MAMP-containing CL livers harbor significantly increased KC numbers via induction of intercellular adhesion molecule 1 on liver sinusoidal endothelium. These CL KCs have a primed yet expected phenotype, with increased major histocompatibility complex class II and lower phagocytic activity that increases susceptibility to liver preservation/reperfusion injury after orthotopic transplantation. The KC number, functional activity, and maturational status are directly related to the concentration of gut-derived MAMPs and can be significantly reduced by broad-spectrum antibiotics, thereby affecting susceptibility to injury.

Eosinophilic gastritis in adult complicated by gastric ulcer perforation.

Eosinophilic gastritis is a rare type of eosinophilic gastrointestinal diseases. Patients with eosinophilic gastritis usually present with symptoms such as nausea, emesis, abdominal pain, and weight loss. In severe cases, patients can suffer rare complications such as gastric outlet obstruction and spontaneous perforation. Here, we present the case of a young adult male who presented with acute onset abdominal pain for 1 day. The patient was found to have significant mural thickening of gastric antrum with pneumoperitoneum on abdominal CT scan, consistent with a perforated gastric ulcer. The patient underwent exploratory laparotomy and required modified graham patch repair. The diagnosis of eosinophilic gastritis was made based on the pathology review of intraoperative endoscopic biopsy specimens.

Dietary polyamines promote intestinal adaptation in an experimental model of short bowel syndrome.

Intestinal adaptation does not necessarily recover absorptive capacity in short bowel syndrome (SBS), sometimes resulting in intestinal failure-associated liver disease (IFALD). Additionally, its therapeutic options remain limited. Polyamines (spermidine and spermine) are known as one of the autophagy inducers and play important roles in promoting the weaning process; however, their impact on intestinal adaptation is unknown. The aim of this study was to investigate the impact of polyamines ingestion on adaptation and hepatic lipid metabolism in SBS. We performed resection of two-thirds of the small intestine in male Lewis rats as an SBS model. They were allocated into three groups and fed different polyamine content diets (0%, 0.01%, 0.1%) for 30 days. Polyamines were confirmed to distribute to remnant intestine, whole blood, and liver. Villous height and number of Ki-67-positive cells in the crypt area increased with the high polyamine diet. Polyamines increased secretory IgA and mucin content in feces, and enhanced tissue Claudin-3 expression. In contrast, polyamines augmented albumin synthesis, mitochondrial DNA copy number, and ATP storage in the liver. Moreover, polyamines promoted autophagy flux and activated AMP-activated protein kinase with suppression of lipogenic gene expression. Polyamines ingestion may provide a new therapeutic option for SBS with IFALD.

Bladder perforation as a rare complication of urethra sounding with a blunt marking pen.

Urethral sounding is the insertion of an object or liquid into the urethra for sexual gratification. It is associated with a substantial risk of loss of the foreign body in the bladder, urethral strictures or infection. Bladder perforation is a rare complication of urethral sounding which is usually associated with a sharp object. Here, we present the case of a young adult female presenting with abdominal pain after practicing urethral sounding with a blunt marking pen. She was found to have an intraperitoneal bladder perforation, requiring exploratory laparotomy and bladder repair.

An unusual case of small bowel obstruction because of body packing.

Body packing is the internal concealment of illicit drugs for the purpose of transportation and evasion of law enforcement. It is associated with medical complications such as acute toxicity from ingested drug, bowel obstruction or perforation. It is rare to require surgical intervention with a small amount of ingested drug packet. Here, we present the case of a young adult male who presented with abdominal pain for 3 days. The patient admitted ingesting a condom filled with suboxone several years ago and denied recent ingestion. The patient was found to have small bowel obstruction with ingested foreign body being a transition point on CT scan, requiring exploratory laparotomy and small bowel resection.

Effect of linearly polarized microwaves on nanomorphology of calcium carbonate mineralization using peptides.

Microwaves are used for diverse applications such as mobile phones, ovens, and therapy devices. However, there are few reports on the effects of microwaves on diseases other than cancer, and on physiological processes. Here, we focused on CaCO3 mineralization as a model of biomineralization and attempted to elucidate the effect of microwaves on CaCO3 mineralization using peptides. We conducted AFM, ζ potential, HPLC, ICP-AES, and relative permittivity measurements. Our findings show that microwaves alter the nanomorphology of the CaCO3 precipitate, from sphere-like particles to string-like structures. Furthermore, microwaves have little effect on the mineralization when the mineralization ability of a peptide is high, but a large effect when the precipitation ability is low. Our findings may be applicable to not only the treatment of teeth and bones but also the development of organic-inorganic nanobiomaterials. This methodology can be expanded to other molecular/atomic reactions under various microwave conditions to alter reaction activity parameters.

Intestinal strangulation caused by a mucocele of the appendix: report of a case.

Intestinal strangulation caused by a mucocele of the appendix is extremely rare and difficult to diagnose. It is not usually suspected pre-operatively. This report presents a case of intestinal strangulation due to a mucous containing cystic lesion that was wrapped around the base of a loop of the small bowel. An 89-year-old female was transferred after an acute onset of abdominal pain. A physical examination revealed severe tenderness with guarding in the right upper quadrant. CT of the abdomen showed a loop of dilated small bowel with edema on the right side of the abdominal cavity suggesting a closed loop obstruction. In addition, a low-density thin-walled mass measuring 5 cm in diameter was also seen in the pelvis. Intestinal strangulation was suspected and emergency laparotomy was thus performed. A loop of terminal ileum 25 cm in length was strangulated by a dilated appendix, and ileocecal resection was performed. The resected appendix measured 9 × 3 cm in size and contained mucus. A histopathological examination showed a mucous containing cystic appendix without mucin-producing, neoplastic epithelial cells. A mucocele of the appendix can present in various ways and it is important to recognize this entity at the time of surgery.

Laparoscopic and endoscopic cooperative surgery for leiomyosarcoma of the stomach: a case report with a review of the literature.

BACKGROUND: Leiomyosarcoma is a rare tumor that could originate from the gastrointestinal tract, uterus, kidney, retroperitoneum, and the soft tissues of the extremities. It accounts for only 1% of all gastrointestinal mesenchymal tumors and primary leiomyosarcoma of the stomach is extremely rare. Most cases reported as leiomyosarcoma of the stomach before the development of KIT immunohistochemistry might be gastrointestinal stromal tumors (GISTs) of the stomach and only 18 cases of leiomyosarcoma of the stomach have been reported since early 2000s. We report here a patient with leiomyosarcoma of the stomach treated by laparoscopic and endoscopic cooperative surgery (LECS). CASE PRESENTATION: A 59-year-old man was referred to our hospital for an early gastric cancer, which was initially treated by endoscopic submucosal dissection. Six months after his initial treatment, a follow-up esophagogastroduodenoscopy revealed a small polypoid lesion at the lesser curvature of the proximal stomach, which appeared to be a hyperplastic polyp. However, one and a half years later, the lesion grew and showed more irregular surface. Biopsy at the time revealed smooth muscle cell proliferation suggestive of leiomyoma. Three years later, the lesion grew even larger and biopsy showed pleomorphic spindle cells. Immunohistochemical study showed positive staining for alpha-smooth muscle actin and desmin, but negative for c-kit and CD34. Ki-67 labeling index was nearly 60%. Based on these findings, the diagnosis of leiomyosarcoma was established. The patient subsequently underwent a partial gastrectomy by LECS. The patient is currently in good condition without recurrence or metastasis at 12 months after surgery. CONCLUSIONS: Leiomyosarcoma of the stomach is extremely rare. This is the first report of leiomyosarcoma of the stomach treated by LECS. We could also follow its appearance change through endoscopic examination for 3 years.

Preoperative pulmonary function tests do not predict the development of pulmonary complications after elective major abdominal surgery: A prospective cohort study.

BACKGROUND: Data describing the association of preoperative pulmonary function testing (PFT) with postoperative pulmonary complications (PPC) are inconsistent. We conducted this prospective study to determine the ability of PFT to predict PPC. MATERIALS AND METHODS: Data were prospectively collected from 676 patients who underwent elective abdominal surgery (emergency and thoracic operations excluded). The primary outcome was the occurrence of PPC within 30 days. Patient and procedure-related factors were examined as risk factors. Multivariate logistic regression analysis was performed using risk factors identified with univariate analysis and area under the curve (AUC) analysis performed. RESULTS: PPC occurred in 29 patients (4.9%). History of smoking or abnormal physical examination were not significantly associated. Multivariate analysis identified age (p = 0.03), operative time (p = 0.02), blood transfusions (p = 0.002), and %VC (p = 0.001) as significant risk factors. AUC with a model including age, operative time, and blood transfusion was 0.83. The addition of %VC to these three variables increased the AUC to 0.89 (p = 0.1). CONCLUSIONS: Age, operative time, blood transfusion, and %VC are significantly associated with an increased risk of PPC. The addition of %VC to other risk factors did not significantly improve the ability to predict PPC, showing that preoperative PFT is not helpful to predict PPC.

Physician attire in the intensive care unit in Japan influences visitors' perception of care.

PURPOSE: The objective of this study is to evaluate the impact of physician attire and behavior on perceptions of care by ICU visitors in Japan. MATERIALS AND METHODS: Visitors were surveyed including 117 at a community hospital and 106 at a university hospital. Demographic data (age, gender, relationship to patient, length of stay) were collected. A seven-point Likert scale (1=strongly agree, 4=neutral, 7=strongly disagree) was used to judge physician attire (name tag, white coat, scrubs, short sleeve shirts, blue jeans, sneakers, clogs), behavior (addressing a patient, carrying a snack) and overall effect on perception of care. RESULTS: There are no significant differences (p>0.05) in demographics comparing the two ICUs, except for increased length of stay at the university ICU. Visitors scored the importance of a name tag (median 2, Interquartile Range 1-2), white coat [3,1-4], addressing the patient by last name [2,1-3], wearing scrubs [3,2-4], sneakers [4,3-5], clogs [4,4-5], short sleeves (4,3.5-5), blue jeans [5,4-6], and carrying a snack [6,5-7]. Visitors scored "attire affects perceptions of care" as [3,2-4]. CONCLUSIONS: Physician attire in the ICU affects perceptions of care. Implementation of attire guidelines which require clothing that does not meet visitor preferences should be accompanied by education programs.

Partial Bile Duct Ligation in the Mouse: A Controlled Model of Localized Obstructive Cholestasis.

In rodents, complete bile duct ligation (cBDL) of the common bile duct is an established surgical technique for studying obstructive cholestasis and bile duct proliferation. However, long-term experiments can lead to increased morbidity and mortality. In select mouse strains with underlying liver disease, meaningful comparisons can be made even with ligation of a single lobe of the liver, which can reduce animal losses and expenses. Here, we describe partial bile duct ligation (pBDL) in the mouse, in which only the left hepatic bile duct is ligated, causing biliary obstruction in the left lobe but not the remaining lobes. With careful microsurgical technique, pBDL experiments can be cost-effective, since the unligated lobe serves as an internal control to the ligated lobes, when subjected to the same conditions in the same animal. Unlike cBDL, a separate sham-operated control group is not necessary. pBDL is highly useful to directly compare localized versus systemic effects of cholestasis and other retained bile components. pBDL can also be repurposed as a novel method to investigate mechanisms related to medications and cell migration.