Increased Serum Levels of Activated Caspases in Murine and Human Biliary Atresia.
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ABSTRACT:
SUBMITTER: Madadi-Sanjani O
PROVIDER: S-EPMC8234421 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Background and aimsBiliary atresia (BA) is a devastating neonatal cholangiopathy that progresses to fibrosis and end-stage liver disease by 2 years of age. Portoenterostomy may reestablish biliary drainage, but, despite drainage, virtually all afflicted patients develop fibrosis and progress to end-stage liver disease requiring liver transplantation for survival.Approach and resultsIn the murine model of BA, rhesus rotavirus (RRV) infection of newborn pups results in a cholangiopathy paralleling human BA and has been used to study mechanistic aspects of the disease. Unfortunately, nearly all RRV-infected pups succumb by day of life 14. Thus, in this study we generated an RRV-TUCH rotavirus reassortant (designated as TR(VP2,VP4) ) that when injected into newborn mice causes an obstructive jaundice phenotype with lower mortality rates. Of the mice that survived, 63% developed Ishak stage 3-5 fibrosis with histopathological signs of inflammation/fibrosis and bile duct obstruction.ConclusionsThis model of rotavirus-induced neonatal fibrosis will provide an opportunity to study disease pathogenesis and has potential to be used in preclinical studies with an objective to identify therapeutic targets that may alter the course of BA.
| S-EPMC7384231 | biostudies-literature
Project description:Biliary atresia (BA) is a progressive disease characterized by bile duct inflammation and fibrosis. The aetiology is unknown and may be due to a virus-induced, autoimmune-mediated injury of cholangiocytes. Cholangiocytes are not only targets of injury but may also modulate hepatic inflammation. The aim of this study was to determine the immune profile of murine cholangiocytes and the ability to function as antigen-presenting cells (APCs) in culture with Rhesus rotavirus (RRV), poly I:C (viral mimic) or interferon-gamma/tumour necrosis factor-alpha.Both the cholangiocyte cell line (long-term culture) and fresh, ex vivo cholangiocytes expressed APC surface markers major histocompatibility complex (MHC)-class I and II and CD40, while only the cultured cell line expressed costimulatory molecules B7-1 and B7-2. Despite APC expression, cultured cholangiocytes were unable to function as competent APCs in T-cell proliferation assays. Furthermore, both cultured and ex vivo cholangiocytes expressed RNA transcripts for many pro-inflammatory cytokines and chemokines.Although cholangiocytes contain APC molecules, they are incompetent at antigen presentation and cannot elicit effective T-cell activation. Upregulation of MHC-class I and II found in BA mice may serve to prime the cholangiocyte as a target for immune-mediated injury. Cholangiocytes produced many pro-inflammatory cytokines and chemokines in the setting of RRV infection and T-helper type 1 cytokine milieu, suggesting a role of cholangiocytes as immune modulators promoting the ongoing inflammation that exists in RRV-induced BA.
| S-EPMC3783657 | biostudies-literature
Project description:?-Bilirubin (B?) forms when bilirubin conjugates covalently bind to albumin by way of nonenzymatic transesterification in patients with cholestasis. Infants with cholestasis with biliary atresia form B?. The aim of the present study was to investigate the factors determining serum B? concentrations in infants with biliary atresia.Study patients were infants enrolled in a prospective study (PROBE: Clinicaltrials.gov NCT00061828) of biliary atresia. We acquired data of concurrently measured serum bilirubin analytes (total bilirubin [TB], conjugated bilirubin [Bc], and unconjugated bilirubin) and applied graphical methods and linear mixed effects model to study factors contributing to B? variability.B? level increased with increasing levels of Bc and TB. In addition, the length of time cholestasis persisted partially determined the level of B?. An increase of 1?mg/dL in Bc is related to approximately 0.36?mg/dL increase in B? (P?<?0.0001); every 100 days of cholestasis is associated with an approximately 1.0?mg/dL increase in B? (P?<?0.0001) given the same level of Bc. Serum albumin levels are not significantly related to B? (P?=?0.89).B? levels in infants with biliary atresia increase with increasing levels of Bc and longer duration of cholestasis. Understanding the relation among B?, Bc, TB, and direct-reacting bilirubin levels can help in interpretation of the clinical extent of cholestasis in infants and children with biliary atresia, assisting in the diagnosis and management of these infants.
| S-EPMC4409472 | biostudies-literature
Project description:The diagnosis of biliary atresia (BA) remains a clinical challenge because affected infants have signs, symptoms, and serum liver biochemistry that are also seen in those with other causes of neonatal cholestasis (non-BA). However, an early diagnosis and prompt surgical treatment are required to improve clinical outcome. Recently, the relative abundance of serum matrix metalloproteinase-7 (MMP-7) was suggested to have discriminatory features for infants with BA. To test the hypothesis that elevated serum concentration of MMP-7 is highly diagnostic for BA, we determined the normal serum concentration of MMP-7 in healthy control infants, and then in 135 consecutive infants being evaluated for cholestasis. The median concentration for MMP-7 was 2.86 ng/mL (interquartile range, IQR: 1.32-5.32) in normal controls, 11.47 ng/mL (IQR: 8.54-24.55) for non-BA, and 121.1 ng/mL (IQR: 85.42-224.4) for BA (P < 0.0001). The area under the curve of MMP-7 for the diagnosis of BA was 0.9900 with a cutoff value of 52.85 ng/mL; the diagnostic sensitivity and specificity were 98.67% and 95.00%, respectively, with a negative predictive value of 98.28%. Conclusion: Serum MMP-7 assay has high sensitivity and specificity to differentiate BA from other neonatal cholestasis, and may be a reliable biomarker for BA.
| S-EPMC6519383 | biostudies-literature
Project description:Biliary atresia (BA) is an inflammatory cholangiopathy of infancy. A proposed mechanism regarding the pathogenesis of BA is that of a virus-induced, immune-mediated injury to bile ducts. The rotavirus (RRV)-induced murine model of BA was utilized to determine the hepatic inflammatory response related to ductal obstruction and if the immune response recapitulated human BA. One week after infection, there was a significant increase in liver CD4(+) T cells producing IFN-gamma and in macrophages producing TNF-alpha. The intrahepatic pattern of inflammation evolved rapidly from an initial predominant CD4(+) Th1 cellular response to a subsequent influx of activated macrophages producing TNF-alpha and iNOS. This immune response persisted despite viral clearance and was representative of the hepatic immune profile present in human BA. Utilization of the murine model of BA yielded mechanistic data that can provide much needed insight into the role played by different arms of the immune system related to the pathogenesis of human BA.
| S-EPMC1950158 | biostudies-other
Project description:Biliary atresia (BA) is the most serious liver disease in infants. Diagnosis currently depends on surgical exploration of the biliary tree. Noninvasive tests that distinguish BA from other types of neonatal liver disease are not available.To identify potential serum biomarkers that classify children with neonatal cholestasis, we performed 2-dimensional difference gel electrophoresis, statistical analysis, and tandem mass spectrometry using serum samples from 19 infants with BA and 19 infants with non-BA neonatal cholestasis.Eleven potential serum biomarkers were found that could in combination classify children with neonatal cholestasis.Although no single biomarker or imaging test adequately distinguishes BA from other types of neonatal cholestasis, combinations of biomarkers, imaging tests, and noninvasive clinical criteria should be further explored as potential tests for rapid and accurate diagnosis of BA.
| S-EPMC2881691 | biostudies-literature
Project description:Biliary atresia (BA) is a neonatal liver disease characterized by progressive fibroinflammatory obliteration of both intrahepatic and extrahepatic bile ducts. The etiologies of BA remain largely unknown, but rotavirus infection has been implicated at least for a subset of patients, and this causal relation has been well demonstrated in mouse models. In this study, we aim to further consolidate this evidence in human biliary organoids. We obtained seven batches of human biliary organoids cultured from fetal liver, adult liver, and bile duct tissues. We found that these organoids are highly susceptible and support the full life cycle of rotavirus infection in three-dimensional culture. The robust infection triggers active virus-host interactions, including interferon-based host defense mechanisms and injury responses. We have observed direct cytopathogenesis in organoids upon rotavirus infection, which may partially recapitulate the development of BA. Importantly, we have demonstrated the efficacy of mycophenolic acid and interferon alpha but not ribavirin in inhibiting rotavirus in biliary organoids. Furthermore, neutralizing antibody targeting rotavirus VP7 protein effectively inhibits infection in organoids. Thus, we have substantiated the causal evidence of rotavirus inducing BA in humans and provided potential strategies to combat the disease.IMPORTANCE There is substantial evidence indicating the possible involvement of rotavirus in biliary atresia (BA) development, at least in a subset of patients, but concrete proof remains lacking. In a mouse model, it has been well demonstrated that rotavirus can infect the biliary epithelium to cause biliary inflammation and obstruction, representing the pathogenesis of BA in humans. By using recently developed organoids technology, we now have demonstrated that human biliary organoids are susceptible to rotavirus infection, and this provokes active virus-host interactions and causes severe cytopathogenesis. Thus, our model recapitulates some essential aspects of BA development. Furthermore, we have demonstrated that antiviral drugs and neutralizing antibodies are capable of counteracting the infection and BA-like morphological changes, suggesting their potential for mitigating BA in patients.
| S-EPMC7448284 | biostudies-literature
Project description:Biliary atresia (BA) is a neonatal T cell-mediated, inflammatory, sclerosing cholangiopathy. In the rhesus rotavirus (RRV)-induced neonatal mouse model of BA (murine BA), mice lacking B cells do not develop BA, and the lack of B cells is associated with loss of T-cell and macrophage activation. The aim of this study was to determine the mechanism of B cell-mediated immune activation (antigen presentation versus cytokine production) in murine BA. Normal neonatal B cells in the liver are predominantly at pro-B and pre-B cellular development. However, BA mice exhibit a significant increase in the number and activation status of mature liver B cells. Adoptively transferred B cells into RRV-infected, B cell-deficient mice were able to reinstate T-cell and macrophage infiltration and biliary injury. Nonetheless, neonatal liver B cells were incompetent at antigen presentation to T cells. Moreover, 3-83 immunoglobulin transgenic mice, in which B cells only present an irrelevant antigen, developed BA, indicating a B-cell antigen-independent mechanism. B cells from BA mice produced a variety of innate and adaptive immune cytokines associated with immune activation. In vitro trans-well studies revealed that BA B cells secreted cytokines that activated T cells based on increased expression of T-cell activation marker cluster of differentiation 69. Conclusion: Neonatal liver B cells are highly activated in murine BA and contribute to immune activation through production of numerous cytokines involved in innate and adaptive immunity; this work provides increased knowledge on the capacity of neonatal B cells to contribute to an inflammatory disease through cytokine-mediated mechanisms, and future studies should focus on targeting B cells as a therapeutic intervention in human BA.
| S-EPMC6195851 | biostudies-literature
Project description:The treatment of biliary atresia (BA) is predominantly surgical with firstly an attempt at restoration of bile flow from the native liver by wide excision of the obstructed, obliterated extrahepatic biliary tree to the level of the porta hepatis and a portoenterostomy using a long Roux loop-Kasai portoenterostomy (KPE). Liver transplantation is reserved for those that fail this and for those where surgery is considered futile for reasons of age or stage of disease. As the aetiology of BA remains ill-defined, so adjuvant treatment has been largely based on pragmatism, trial and error. Systematic analysis of the few randomized placebo-controlled trial data and less well-controlled cohort studies have suggested benefit from post-operative high-dose steroids and ursodeoxycholic acid (UDCA) while the benefit of long-term prophylactic antibiotics, bile acid sequestrants (e.g., colestyramine) or probiotics remains unproven. Newer modalities such as antiviral therapy (AVT), immunoglobulin, FXR agonists (e.g., obeticholic acid), ileal bile acid transporter (IBAT) antagonists (e.g., maralixibat) remain unproven. This article reviews the current evidence for the efficacy of adjuvant medical therapy in BA.
| S-EPMC7347763 | biostudies-literature
Project description:Biliary atresia (BA) is a fibroinflammatory obstruction of the extrahepatic biliary tree in neonates. While intrahepatic bile duct proliferation is universal at diagnosis, bile duct paucity develops later. We hypothesized that polarized T helper lymphocyte responses orchestrate progression of intrahepatic biliary injury in this disease. Interleukin 17A (IL-17A)-green fluorescent protein, cluster of differentiation 11c (CD11c)/diphtheria toxin receptor, and IL-17 receptor A-/- mice were used to examine T-lymphocyte polarization, inflammatory leukocyte recruitment, and biliary injury in rhesus rotavirus-induced BA. Multiparameter flow cytometry and automated image analysis of immunostaining were applied to liver tissue samples from infants with BA. In the mouse model, activated CD4+ lymphocytes started to emerge in the liver on day 8 after viral challenge, while innate immune responses were waning. Plasma IL-17A levels rose concomitantly with hepatic accumulation of T helper 17 lymphocytes and myeloid dendritic cells. Targeted depletion of CD11c+ dendritic cells diminished hepatic IL-17A production and ameliorated intrahepatic bile duct injury. Recombinant IL-17A induced expression of chemokine (C-C motif) ligand 2 in neonatal cholangiocytes in vitro, and blockade of the corresponding chemokine (C-C motif) receptor 2 reduced recruitment of inflammatory macrophages to the liver in vivo. Genetic disruption of IL-17A signaling was associated with down-regulation of hepatic Ccl2/Ccr2 messenger RNA expression, reduced infiltration of the liver with inflammatory Ly6Chi macrophages, and improved survival. In the liver of infants with BA, cholangiocytes were found to express IL-17 receptor A, and the prevalence of IL-17A+ cells was positively correlated with the degree of CD68+ macrophage infiltration at diagnosis. Hepatic CD4+ lymphocytes were chief producers of IL-17A in patients with progressive disease undergoing liver transplantation.These findings identify the dendritic cell-T helper 17-macrophage axis as a target for the development of strategies to block progression of intrahepatic bile duct injury in patients with BA. (Hepatology 2017;65:174-188).
| S-EPMC5191928 | biostudies-literature