ABSTRACT
The disease spectrum of ABCB4 gene mutation involves various diseases such as progressive familial intrahepatic cholestasis type 3 （PFIC3）， gallstone disease， intrahepatic cholestasis of pregnancy， portal hypertension， liver cirrhosis， and even primary hepatic and biliary malignancies. A young male patient was admitted to Department of Hepatobiliary Medicine， Eastern Hepatobiliary Surgery Hospital， and was initially diagnosed with liver cirrhosis and gallstones， and he was planned to receive laparoscopic cholecystectomy. Preoperative examination showed abnormal liver function， liver cirrhosis， splenomegaly， and mild esophageal varices， and next-generation sequencing was performed to make a confirmed diagnosis of ABCB4 gene mutation-associated liver cirrhosis with gallstones. The liver function of the patient gradually returned to normal after cholagogic treatment with ursodeoxycholic acid capsules.
ABSTRACT
ABCB4-related disease is the syndrome of bile secretion disorder caused by gene mutations and can cause bile duct injury, portal hypertension, and liver cirrhosis in clinical practice. With the development of genetics and gene sequencing techniques in recent years, more and more mutation sites have been identified; however, since this is a relatively complex disease, the pathogenicity and pathogenic mechanism of mutations remain unclear. Meanwhile, since this disease is rare, it is difficult to determine the pathogenicity of ABCB4 mutations based on basic research or clinical data. Therefore, it is urgent to establish the association between ABCB4 genotypes and phenotypes and construct a complete system in basic research and clinical practice.
ABSTRACT
Objective To investigate the effects of gefitinib on early embryonic development and expression of abcb4 tumor resistance genes in zebrafish.Methods Zebrafish were adopted as experimental animals and divided into gefitinib group,mixture of doxorubicin and gefitinib group and blank group.Zebrafish embryos of 0.5-1.5 hours after fertilization(0.5-1.5 hpf) were exposed to different concentrations of gefitinib,and then embryo development of zebrafish in 24-120 hpf was observed and the number of death,hatch and malformation was recorded.The embryo mortality was calculated under different concentrations of gefitinib at different time points,and the numerical value of IC50 was calculated;Hatching rates of zebrafish embryo in 48 hpf and 72 hpf and malformation rates of zebrafish embryo in 120 hpf were calculated.The zebrafish embryos exposed to different concentrations of gefitinib in different groups were collected,and the expressionof abcb4 gene in zebrafish embryos was detected by real-time quantitative PCR.Results Gefitinib IC50 in zebrafish embryos was 16.18 μmol/L.Compared with the control group,higher dosage (20 μmol/L) of gefitinib in other two groups significantly decreased hatching rates of embryos,and had obvious embryonic lethal effects and teratogenic effects.Moreover,the mRNA levels of the abcb4 gene in the zebrafish embryos of gefitinib group were not significantly changed,whereas the mRNA levels of the abcb4 gene in mixture of doxorubicin and gefitinib group were significantly different(P＜0.05).Conclusion Gefitinib has no significant effects on the expression of abcb4 tumor resistance gene in early development of zebrafish embryos(P＞0.05),but it can reverse the drug resistant effects of doxorubicin,suggesting that zebrafish can construct tumor resistance model.
ABSTRACT
Síndrome LPAC (Low Phospholipid-Associated Cholelithiasis) é uma enfermidade rara, que cursa com manifestações clínicas recorrentes relacionadas à litíase biliar, mesmo após colecistectomia em indivíduos jovens habitualmente com início dos sintomas antes dos 40 anos. Mutações no gene ABCB4 geram baixa concentração de fosfolipídios na secreção biliar, o que favorece a formação de cálculos de colesterol. Seu diagnóstico é estabelecido por critérios clínicos e o tratamento é fundamentado no uso do ácido ursodesoxicólico (UDCA). O objetivo deste artigo é relatar o caso de um paciente com síndrome LPAC.
Achalasia is an uncommon disorder that affects about LPAC syndrome (Low phospholipid-associated cholelithiasis) is a rare illness that leads to recurrent clinical manifestations related to gallstones, even after cholecystectomy in young individuals, usually with onset of symptoms before age 40. Mutations in the gene ABCB4 generate low concentration of phospholipids in bile secretion, which promotes the formation of cholesterol calculations. The diagnosis is established by clinical criteria and treatment is based on the use of ursodeoxycholic acid (UDCA). The objective of this paper is to report the case of a patient with LPAC syndrome.
Subject(s)
Humans , Female , Middle Aged , Bile Ducts , Lithiasis , Syndrome , Ursodeoxycholic Acid , CholelithiasisABSTRACT
This review focuses on various components of bile acid signaling in relation to cholangiocytes. Their roles as targets for potential therapies for cholangiopathies are also explored. While many factors are involved in these complex signaling pathways, this review emphasizes the roles of transmembrane G protein coupled receptor (TGR5), farnesoid X receptor (FXR), ursodeoxycholic acid (UDCA) and the bicarbonate umbrella. Following a general background on cholangiocytes and bile acids, we will expand the review and include sections that are most recently known (within 5-7 years) regarding the field of bile acid signaling and cholangiocyte function. These findings all demonstrate that bile acids influence biliary functions which can, in turn, regulate the cholangiocyte response during pathological events.
ABSTRACT
Multidrug resistance 3 (MDR3) is expressed on the canalicular membrane of the hepatocytes and plays an important role in protecting the liver from bile acids. Altered ABCB4 gene expression can lead to a rare hepatic disease, low phospholipid-associated cholelithiasis (LPAC). In this study, we characterized 3 ABCB4 mutations in LPAC patients using various in vitro assay systems. We first measured the ability of each mutant to transport paclitaxel and then the mechanisms by which these mutations might change MDR3 transport activity were determined using immunoblotting, cell surface protein biotinylation, and immunofluorescence. Through a membrane vesicular transport assay, we observed that the uptake of paclitaxel was significantly reduced in membrane vesicles expressing 2 ABCB4 mutations, F165I and S320F. Both mutants showed significantly decreased total and cell surface MDR3 expression. These data suggest two missense mutations of ABCB4 may alter function of MDR3 and ultimately can be determined as LPAC-causing mutations.
Subject(s)
Humans , Bile Acids and Salts , Biotinylation , Cholelithiasis , Drug Resistance, Multiple , Fluorescent Antibody Technique , Gene Expression , Hepatocytes , Immunoblotting , Liver , Membranes , Mutation, Missense , PaclitaxelABSTRACT
The ABCB4 gene,also called MDR3,encodes the MDR3 protein which is localized to the hepatocyte canalicular membrane and is demonstrated to be a phosphatidylcholine translocase.The recent study showed that ABCB4 deficiency was associated with several cholestatic disorders,but the pathogenesis is not clear.This review highlights recent advances in the structure and function of ABCB4 gene,and the relationship between ABCB4 gene and cholestatic diseases.