Hepatic progenitor cells in human liver tumor development

In recent years, the results of several studies suggest that human liver tumors can be derived from hepatic progenitor cells rather than from mature cell types. The available data indeed strongly suggest that most combined hepatocellular-cholangiocarcinomas arise from hepatic progenitor cells that retained their potential to differentiate into the hepatocytic and biliary lineages. Hepatic progenitor cells could also be the basis for some hepatocellular carcinomas and hepatocellular adenomas, although it is very difficult to determine the origin of an individual hepatocellular carcinoma. There is currently not enough data to make statements regarding a hepatic progenitor cell origin of cholangiocarcinoma. The presence of hepatic progenitor cell markers and the presence and extent of the cholangiocellular component are factors that are related to the prognosis of hepatocellular carcinomas and combined hepatocellular- cholangiocarcinomas, respectively.

Efficient generation of functional hepatocytelike cells from mouse liver progenitor cells via indirect co-culture with immortalized human hepatic stellate cells

BACKGROUND： Differentiation of liver progenitor cells（LPCs） to functional hepatocytes holds great potential to develop new strategies for hepatocyte transplantation and the screening of drug-induced cytotoxicity. However, reports on the efficient and convenient hepatic differentiation of LPCs to hepatocytes are few. The present study aims to investigate the possibility of generating functional hepatocytes from LPCs in an indirect co-culture system.METHODS： Mouse LPCs were co-cultured in Transwell plates with an immortalized human hepatic stellate cell line（HSCLi） we previously established. The morphology, expression of hepatic markers, and functions of mouse LPC-derived cells were monitored and compared with those of conventionally cultured LPCs. RESULTS： Co-culturing with HSC-Li cells induced differentiation of mouse LPCs into functional hepatocyte-like cells. The differentiated cells were morphologically transformed into hepatocyte-like cells 3 days after co-culture initiation. In addition, the differentiated cells expressed liver-specific genes and possessed hepatic functions, including glycogen storage, lowdensity lipoprotein uptake, albumin secretion, urea synthesis, and cytochrome P450 1A2 enzymatic activity.CONCLUSIONS： Our method, which employs indirect co-culture with HSC-Li cells, can efficiently induce the differentiation of LPCs into functional hepatocytes. This finding suggests that this co-culture system can be a useful method for the efficient generation of functional hepatocytes from LPCs.

BMP-4 induced proliferation and oriented differentiation of rat hepatic oval cells into hepatocytes

Objective:To explore the role of bone morphogenetic protein 4(BMP-4) in hepatic progenitor cells(HPCs).Methods:The effect of BMP-4 on rat hepatic oval cells was examined by using the WB-F344 rat hepatocytic epithelial stem-cell-like cell line.This hepatocytic cell line could exert various hepatocytc functions including the secretion of albumin and urea.Immunohistochemistry was used to examine the effects of BMP-4 and its antagonist,Noggin,on the proliferation and differentiation of these cells,cellular uptake and excretion of indocyanine green,the periodic acid-schiff(PAS) assay for glycogen storage and the expression of hepatic markers.Results:Our results showed for the first time that BMP-4 may acted as a potential inducer of hepatic differentiation in rat hepatic oval cells.Conclusions:This cell source offers a much-needed attractive and expandable source for future investigations of drug screening,stem cell technologies and cellular transplantation,in a society with increasing levels of liver disease and damage.

Syngeneic implantation of mouse hepatic progenitor cell-derived three-dimensional liver tissue with dense collagen fibrils

BACKGROUND Liver transplantation is a therapy for irreversible liver failure;however,at present,donor organs are in short supply.Cell transplantation therapy for liver failure is still at the developmental stage and is critically limited by a shortage of human primary hepatocytes.AIM To investigate the possibility that hepatic progenitor cells(HPCs)prepared from the portal branch-ligated hepatic lobe may be used in regenerative medicine,we attempted to enable the implantation of extracellular matrices containing organoids consisting of HPC-derived hepatocytes and non-parenchymal cells.METHODS In vitro liver organoid tissue has been generated by accumulating collagen fibrils,fibroblasts,and HPCs on a mesh of polylactic acid fabric using a bioreactor;this was subsequently implanted into syngeneic wild-type mice.RESULTS The in vitro liver organoid tissues generated transplantable tissues in the condensed collagen fibril matrix and were obtained from the mouse through partial hepatectomy.CONCLUSION Liver organoid tissue was produced from expanded HPCs using an originally designed bioreactor system.This tissue was comparable to liver lobules,and with fibroblasts embedded in the network collagen fibrils of this artificial tissue,it is useful for reconstructing the hepatic interstitial structure.

Direct hepatic differentiation of mouse embryonic stem cells induced by valproic acid and cytokines

AIM: To develop a protocol for direct hepatic lineage differentiation from early developmental progenitors to a population of mature hepatocytes.METHODS: Hepatic progenitor cells and then mature hepatocytes from mouse embryonic stem (ES) cells were obtained in a sequential manner, induced by valproic acid (VPA) and cytokines (hepatocyte growth factor, epidermal growth factor and insulin). Morphological changes of the differentiated cells were examined by phase-contrast microscopy and electron microscopy. Reverse transcription polymerase chain reaction and immunocytochemical analyses were used to evaluate the gene expression prof iles of the VPA-induced hepatic progenitors and the hepatic progenitor-derived hepatocytes. Glycogen storage, cytochrome P450 activity, transplantation assay, differentiation of bile duct-like structures and tumorigenic analyses were performed for the functional identification of the differentiated cells. Furthermore, FACS and electron microscopy were usedfor the analyses of cell cycle profile and apoptosis in VPA-induced hepatic differentiated cells.RESULTS: Based on the combination of VPA and cytokines, mouse ES cells differentiated into a uniform and homogeneous cell population of hepatic progenitor cells and then matured into functional hepatocytes. The progenitor population shared several characteristics with ES cells and hepatic stem/progenitor cells, and represented a novel progenitor cell between ES and hepatic oval cells in embryonic development. The differentiated hepatocytes from progenitor cells shared typical characteristics with mature hepatocytes, including the patterns of gene expression, immunological markers, in vitro hepatocyte functions and in vivo capacity to restore acute-damaged liver function. In addition, the differentiation of hepatic progenitor cells from ES cells was accompanied by signif icant cell cycle arrest and selective survival of differentiating cells towards hepatic lineages.CONCLUSION: Hepatic cells of different developmental stages from early progenitors to matured hepatocytes can be acquired in the appropriate order based on sequential induction with VPA and cytokines.

Xenogeneic hepatic progenitor cell transplantation ameliorate CCl_4 /partial hepatectomy-induced rat acute liver failure

Objective: Hepatic progenitor cell transplantation has shed light on the treatment of liver failure. The present study was designed to evaluate whether xenogeneic liver epithelial progenitor cells(LEPCs) transplantation could promote liver recovery in a rat model of acute liver failure. The engraftment and hepatocytic differentiation of transplanted hepatic progenitor cells in the rat spleen was also investigated. Methods: LEPCs were propagated in vitro for long and transduced with lentiviral vector carrying mCherry gene. Intraperitoneal injection of CCl4 followed by 2/3 partial hepatectomy three days later were used to establish rat models of acute liver failure. Rats were intrasplenically injected with mCherry modified LEPCs(n=20, 1×107cells/0.5 mL) or the same volume of medium(n=20). Serum liver enzymes(ALT, AST) and liver histology were evaluated for 21 days after transplantation. The engraftment of transplanted LEPCs in the spleens was tested by polymerase chain reaction(PCR) amplification targeting mCherry gene. The differentiation into hepatocytic lineage of transplanted LEPCs was investigated using immunohistochemistry staining against Alb. Results: LEPCs were effectively transduced with lentiviral vector showing a transduction efficiency of 90%. Compared with control, cell-injected group displayed significantly lower levels of ALT and AST(P<0.05) and better histological features including less swelling change and hepatocyte death. PCR amplification of mCherry sequences confirmed the engraftment of LEPCs in the spleens. Alb-positive cells first appeared 5 days after cell transplantation and the number of Alb-positive cells increased substantially(P<0.05), which revealed the hepatocytic differentiation process. Conclusion: Xenogeneic hepatic progenitor cells can engraft and differentiate into hepatocytes in the splenic parenchyma. Intrasplenic delivery of hepatic progenitor cells ameliorates CCl4 /partial hepatectomy-induced liver injury in rats.

Characterization of hepatic progenitors from human fetal liver during second trimester

AIM: To enrich hepatic progenitors using epithelial cell adhesion molecule (EpCAM) as a marker from human fetal liver and investigate the expression of human leukocyte antigen (HLA) and their markers associated with hepatic progenitor cells. METHODS: EpCAM +ve cells were isolated using magnetic cell sorting (MACS) from human fetuses (n = 10) at 15-25 wk gestation. Expression of markers for hepatic progenitors such as albumin, alpha-fetoprotein (AFP), CD29 (integrin β1), CD49f (integrin α6) and CD90 (Thy 1) was studied by using flow cytometry, immunocytochemistry and RT-PCR; HLA class Ⅰ (A, B, C) and class Ⅱ (DR) expression was studied by flow cytometry only. RESULTS: FACS analysis indicated that EpCAM +ve cells were positive for CD29, CD49f, CD90, CD34, HLA class Ⅰ, albumin and AFP but negative for HLA class Ⅱ (DR) and CD45. RT PCR showed that EpCAM +ve cells expressed liver epithelial markers (CK18), biliary specific marker (CK19) and hepatic markers (albumin, AFP). On immunocytochemical staining, EpCAM +ve cells were shown positive signals for CK18 and albumin. CONCLUSION: Our study suggests that these EpCAM +ve cells can be used as hepatic progenitors for cell transplantation with a minimum risk of alloreactivity and these cells may serve as a potential source for enrichment of hepatic progenitor.

Hepatitis B virus X protein induces hepatic stem cell-like features in hepatocellular carcinoma by activating KDM5B

AIM To determine the role of hepatitis B virus X protein(HBx), HBx in regulating hepatic progenitor cell(HPC)-like features in hepatocellular carcinoma(HCC) and the underlying molecular mechanisms.METHODS We used a retrovirus vector to introduce wild type HBx or empty vector into Hep G2 cells. We then used these cells to analyze cell proliferation, senescence, transformation, and stem-like features. Gene expression profiling was carried out on Affymetrix GeneC hip Human U133A2.0 ver.2 arrays according to the manufacturer's protocol. Unsupervised hierarchical clustering analysis and Class Comparison analysis were performed by BRB-Array Tools software Version 4.2.2. A total of 238 hepatitis B virus(HBV)-related HCC patients' array data were used for analyzing clinical features.RESULTS The histone demethylase KDM5 B was significantlyhighly expressed in HBV-related HCC cases(P < 0.01). In HBV proteins, only HBx up-regulated KDM5 B by activating c-myc. Hepatic stem cell(Hp SC) markers(EpC AM, AFP, PROM1, and NANOG) were significantly highly expressed in KDM5B-high HCC cases(P < 0.01). KDM5 B played an important role in maintaining HpS Clike features and was associated with a poor prognosis. Moreover, inhibition of KDM5 B suppressed spheroid formation and cell invasion in vitro.CONCLUSION HBx activates the histone demethylase KDM5 B and induces HPC-like features in HCC. Histone demethylases KDM5 B may be an important therapeutic target against HBV-related HCC cases.

Endothelial precursor cells promote angiogenesis in hepatocellular carcinoma

AIM:To investigate the role of bone marrow-derived endothelial progenitor cells(EPCs) in the angiogenesis of hepatocellular carcinoma(HCC).METHODS:The bone marrow of HCC mice was reconstructed by transplanting green fluorescent protein(GFP) + bone marrow cells.The concentration of circulating EPCs was determined by colony-forming assays and fluorescence-activated cell sorting.Serum and tissue levels of vascular endothelial growth factor(VEGF) and colony-stimulating factor(CSF) were quantified by enzyme-linked immunosorbent assay.The distribution of EPCs in tumor and tumor-free tissues was detected by immunohistochemistry and real-time polymerase chain reaction.The incorporation of EPCs into hepatic vessels was examined by immunofluorescence and immunohistochemistry.The proportion of EPCs in vessels was then calculated.RESULTS:The HCC model was successful established.The flow cytometry analysis showed the mean percentage of CD133CD34 and CD133VEGFR2 double positive cells in HCC mice was 0.45% ± 0.16% and 0.20% ± 0.09% respectively.These values are much higher than in the sham-operation group(0.11% ± 0.13%,0.05% ± 0.11%,n = 9) at 14 d after modeling.At 21 d,the mean percentage of circulating CD133CD34 and CD133VEGFR2 cells is 0.23% ± 0.19%,0.25% ± 0.15% in HCC model vs 0.05% ± 0.04%,0.12% ± 0.11% in control.Compared to the transient increase observed in controls,the higher level of circulating EPCs were induced by HCC.In addition,the level of serum VEGF and CSF increased gradually in HCC,reaching its peak 14 d after modeling,then slowly decreased.Consecutive sections stained for the CD133 and CD34 antigens showed that the CD133+ and CD34+ VEGFR2 cells were mostly recruited to HCC tissue and concentrated in tumor microvessels.Under fluorescence microscopy,the bone-marrow(BM)-derived cells labeled with GFP were concentrated in the same area.The relative levels of CD133 and CD34 gene expression were elevated in tumors,around 5.0 and 3.8 times that of the tumor free area.In frozen liver sections from HCC mice,cells co-expressing CD133 and VEGFR2 were identified by immunohistochemical staining using anti-CD133 and VEGFR2 antibodies.In tumor tissue,the double-positive cells were incorporated into vessel walls.In immunofluorescent staining.These CD31 and GFP double positive cells are direct evidence that tumor vascular endothelial cells(VECs) come partly from BM-derived EPCs.The proportion of GFP CD31 double positive VECs(out of all VECs) on day 21 was around 35.3% ± 21.2%.This is much higher than the value recorded on day 7 group(17.1% ± 8.9%).The expression of intercellular adhesion molecule 1,vascular adhesion molecule 1,and VEGF was higher in tumor areas than in tumor-free tissues.CONCLUSION:Mobilized EPCs were found to participate in tumor vasculogenesis of HCC.Inhibiting EPC mobilization or recruitment to tumor tissue may be an efficient strategy for treating HCC.

Long-term and non-invasive in vivo tracking of DiD dye-labeled human hepatic progenitors in chronic liver disease models

BACKGROUND Chronic liver diseases(CLD)are the major public health burden due to the continuous increasing rate of global morbidity and mortality.The inherent limitations of organ transplantation have led to the development of stem cell-based therapy as a supportive and promising therapeutic option.However,identifying the fate of transplanted cells in vivo represents a crucial obstacle.AIM To evaluate the potential applicability of DiD dye as a cell labeling agent for longterm,and non-invasive in vivo tracking of transplanted cells in the liver.METHODS Magnetically sorted,epithelial cell adhesion molecule positive(1×106 cells/mL)fetal hepatic progenitor cells were labeled with DiD dye and transplanted into the livers of CLD-severe combined immunodeficiency(SCID)mice.Near-infrared(NIR)imaging was performed for in vivo tracking of the DiD-labeled transplanted cells along with colocalization of hepatic markers for up to 80 d.The existence of human cells within mouse livers was identified using Alu polymerase chain reaction and sequencing.RESULTS NIR fluorescence imaging of CLD-SCID mice showed a positive fluorescence signal of DiD at days 7,15,30,45,60,and 80 post-transplantation.Furthermore,positive staining of cytokeratin,c-Met,and albumin colocalizing with DiD fluorescence clearly demonstrated that the fluorescent signal of hepatic markers emerged from the DiD-labeled transplanted cells.Recovery of liver function was also observed with serum levels of glutamic-oxaloacetic transaminase,glutamate-pyruvate transaminase,and bilirubin.The detection of human-specific Alu sequence from the transplanted mouse livers provided evidence for the survival of transplanted cells at day 80.CONCLUSION DiD-labeling is promising for long-term and non-invasive in vivo cell tracking,and understanding the regenerative mechanisms incurred by the transplanted cells.

Yiguanjian decoction enhances fetal liver stem/progenitor cell-mediated repair of liver cirrhosis through regulation of macrophage activation state

AIM To investigate whether Yiguanjian decoction(YGJ) has an anti-liver cirrhotic effect and whether it regulates hepatic stem cell differentiation.METHODS A rat model of liver cirrhosis was established via subcutaneous injection of carbon tetrachloride(CCl4) for8 wk. From the beginning of the ninth week, the rats received 2-acetylaminofluorene(2-AAF) by oral gavage and a DLK-1+ fetal liver stem/progenitor cell(FLSPC)transplant or an FLSPC transplant in combination with YGJ treatment for 4 wk. In vitro, lipopolysaccharide(LPS)-activated macrophages were co-cultured with WB-F344 cells, and the differentiation of WB-F344 cells was observed in the presence and absence of YGJ treatment.RESULTS FLSPC transplantation improved liver function and histopathology, and inhibited the activation of the noncanonical Wnt signaling pathway, while activating the canonical Wnt signaling pathway. YGJ enhanced the therapeutic effects of FLSPCs and also promoted the liver regeneration differentiation of FLSPCs into hepatocytes.In vitro, LPS-activated macrophages promoted the differentiation of WB-F344 cells into myofibroblasts, and the canonical Wnt signaling was inhibited while the noncanonical Wnt signaling was activated in WB-F344 cells.YGJ suppressed the activation of macrophages and then inhibited non-canonical Wnt signaling and promoted canonical Wnt signaling.CONCLUSION YGJ enhances FLSPC-mediated repair of liver cirrhosis through regulation of macrophage activation state, and YGJ in combination with stem cell transplantation may be a suitable treatment for end-stage liver cirrhosis.

Multiple cells of origin in cholangiocarcinoma underlie biological,epidemiological and clinical heterogeneity

Recent histological and molecular characterization of cholangiocarcinoma(CCA) highlights the heterogeneity of this cancer that may emerge at different sites of the biliary tree and with different macroscopic or morphological features.Furthermore,different stem cell niches have been recently described in the liver and biliarytree,suggesting this as the basis of the heterogeneity of intrahepatic(IH)-and extrahepatic(EH)-CCAs,which are two largely different tumors from both biological and epidemiological points of view.The complexity of the organization of the liver stem cell compartments could underlie the CCA clinical-pathological heterogeneity and the criticisms in classifying primitive liver tumors.These recent advances highlight a possible new classification of CCAs based on cells of origin and this responds to the need of generating homogenous diagnostic,prognostic and,hopefully,therapeutic categories of IH-and EH-CCAs.

Review to better understand the macroscopic subtypes and histogenesis of intrahepatic cholangiocarcinoma

Intrahepatic cholangiocarcinoma is macroscopically classified into three subtypes, mass-forming-type, periductal infiltrating-type, and intraductal growth-type. Each subtype should be preoperatively differentiated to perform the valid surgical resection. Recent researches have revealed the clinical, radiologic, pathobiological characteristics of each subtype. We reviewed recently published studies covering various aspects of intrahepatic cholangiocarcinoma(ICC), focusing especially on the macroscopic subtypes and stem cell features to better understand the pathophysiology of ICC and to establish the valid therapeutic strategy.

In vitro cultivation and differentiation of fetal liver stem cells from mice

During embryonic development, pluripotent endoderm tissue in the developing foregut may adopt pancreatic fate or hepatic fate depending on the activation of key developmental regulators. Transdifferentiation occurs between hepato- cytes and pancreatic cells under specific conditions. Hepatocytes and pancreatic cells have the common endodermal progenitor cells. In this study we isolated hepatic stem/progenitor cells from embryonic day (ED) 12-14 Kun-Ming mice with fluorescence-activated cell sorting (FACS). The cells were cultured under specific conditions. The cultured cells deploy dithizone staining and immunocytochemical staining at the 15th, 30th and 40th day after isolation. The results indicated the presence of insulin-producing cells. When the insulin-producing cells were transplanted into alloxan- induced diabetic mice, the nonfasting blood glucose level was reduced. These results suggested that fetal liver stem/ progenitor cells could be converted into insulin-producing cells under specific culture conditions. Fetal liver stem/ progenitor cells could become the potential source of insulin-producing cells for successful cell transplantation therapy strategies of diabetes.

Stimulation of oval cell and hepatocyte proliferation by exogenous bombesin and neurotensin in partially hepatectomized rats

AIM:To investigate the effect of the neuropeptides bombesin(BBS)and neurotensin(NT)on oval cell proliferation in partially hepatectomized rats not pretreated with a known hepatocyte inhibitor.METHODS:Seventy male Wistar rats were randomly divided into five groups:Ⅰ=controls,Ⅱ=sham operated,Ⅲ=partial hepatectomy 70%(PHx),Ⅳ=PHx+ BBS(30μg/kg per day),Ⅴ=PHx+NT(300μg/kg per day).Forty eight hours after liver resection,portal en-dotoxin levels and hepatic glutathione redox state were determined.α-fetoprotein(AFP)mRNA(in situ hybridisation),cytokeratin-19 and Ki67 antigen expression (immunohistochemistry)and apoptosis(TUNEL)were evaluated on liver tissue samples.Cells with morphological features of oval cells that were cytokeratin-19 (+)and AFP mRNA(+)were scored in morphometric analysis and their proliferation was recorded.In addition,the proliferation and apoptotic rates of hepatocytes were determined.RESULTS:In the control and sham operated groups,oval cells were significantly less compared to groups Ⅲ,ⅣandⅤ(P<0.001).The neuropeptides BBS and NT significantly increased the proliferation of oval cells compared to groupⅢ(P<0.001).In addition,BBS and NT induced a significant increase of hepatocyte proliferation(P<0.001),whereas it decreased their apoptotic activity(P<0.001)compared to groupⅢ.BBS and NT significantly decreased portal endotoxemia (P<0.001)and increased the hepatic GSH:GSSG ratio (P<0.05 and P<0.001,respectively)compared to groupⅢ.CONCLUSION:BBS and NT stimulated oval cell proliferation in a model of liver regeneration,without use of concomitant suppression of hepatocyte proliferation as oval cell activation stimuli,and improved the hepatocyte regenerative response.This peptides-induced combined stimulation of oval cell and hepatocyte proliferation might serve as a possible treatment modality for several liver diseases.

Clinical features,histology,and histogenesis of combined hepatocellular-cholangiocarcinoma

Combined hepatocellular-cholangiocarcinoma(CHC) is a rare tumor with poor prognosis,with incidence ranging from 1.0%-4.7% of all primary hepatic tumors.This entity will be soon renamed as hepato-cholangiocarcinoma.The known risk factors for hepatocellular carcinoma(HCC) have been implicated for CHC including viral hepatitis and cirrhosis.It is difficult to diagnose this tumor pre-operatively.The predominant histologic component within the tumor largely determines the predominant radiographic features making it a difficult distinction.Heterogeneous and overlapping imaging features of HCC and cholangiocarcinoma should raise the suspicion for CHC and multiple core biopsies(from different areas of tumor) are recommended before administering treatment.Serum tumor markers CA19-9 and alpha-fetoprotein can aid in the diagnosis,but it remains a challenging diagnosis prior to resection.There is sufficient data to support bipotent hepatic progenitor cells as the cell of origin for CHC.The current World Health Organization classification categorizes two main types of CHC based on histo-morphological features:Classical type and CHC with stem cell features.Liver transplant is one of the available treatment modalities with other management options including transarterial chemoembolization,radiofrequency ablation,and percutaneous ethanol injection.We present a review paper on CHC highlighting the risk factors,origin,histological classification and therapeutic modalities.

Effect of liver regeneration on malignant hepatic tumors

Liver regeneration after major surgery may activate occult micrometastases and facilitate tumor growth,leading to liver tumor recurrence.Molecular changes during liver regeneration can provide a microenvironment that stimulates intrahepatic tumor propagation through alterations in cellular signaling pathways,where activation and proliferation of mature hepatocytes,hepatic progenitor cells,non-parenchymal liver cells might favor both liver regeneration and tumor growth.This review highlights recent advances of tumor growth and development in the regenerating liver,possible mechanisms and clinical implications.

肝巨噬细胞调控肝癌癌前病变恶变的研究进展

肝巨噬细胞是肝脏中重要的免疫细胞,其通过极化为M1型和M2型,分别表达“促炎因子”和“抑炎因子”,进而发挥调控炎症损伤反应的作用。肝祖细胞恶变是肝癌癌前病变恶性进展的核心机制,其发生的关键因素是炎症损伤微环境的持续刺激,与M1/M2巨噬细胞极化密切相关。本综述主要围绕“巨噬细胞极化-慢性炎症-肝祖细胞恶变”关系进行探讨,为肝癌癌前病变的预防和治疗提供重要的理论依据。

肝胆损伤后胆管反应的调控机制及标志物的研究现状

胆管反应存在于多种肝胆损伤疾病中,并在其预后与疾病进展方面具有独特的临床意义。当前的研究多集中于胆管反应的发生与调控机制,这将有助于我们更好地理解胆管反应的临床意义并挖掘更多的治疗靶点。此外,胆管反应相关标志物在预测疾病预后与进展方面也具备一定作用,但目前对此的关注相对较少。本文旨在总结近年来在胆管反应调控机制方面的研究进展并提出当前对胆管反应相关标志物的研究现状。

maturity of associating liver partition and portal vein ligation for staged hepatectomy-derived liver regeneration in a rat model

AIM To establish a rat model for evaluating the maturity of liver regeneration derived from associating liver partition and portal vein ligation for staged hepatectomy(ALPPS).METHODS In the present study, ALPPS, partial hepatecotmy(PHx), and sham rat models were established initially, which were validated by significant increase of proliferative markers including Ki-67, proliferating cell nuclear antigen, and cyclin D1. In the setting of accelerated proliferation in volume at the second and fifth day after ALPPS, the characteristics of newborn hepatocytes, as well as specific markers of progenitor hepatic cell, were identified. Afterwards, the detection of liver function followed by cluster analysis of functional gene expression were performed to evaluate the maturity.RESULTS Compared with PHx and sham groups, the proliferation of f LR was significantly higher in ALPPS group(P = 0.023 and 0.001 at second day, P = 0.034 and P < 0.001 at fifth day after stage I). Meanwhile, the increased expression of proliferative markers including Ki-67, proliferating cell nuclear antigen, and cyclin D1 verified the accelerated liver regeneration derived from ALPPS procedure. However, ALPPS-induced Sox9 positive hepatocytes significantly increased beyond the portal triad, which indicated the progenitor hepatic cell was potentially involved. And the characteristics of ALPPSinduced hepatocytes indicated the lower expression of hepatocyte nuclear factor 4 and anti-tryptase in early proliferative stage. Both suggested the immaturity of ALPPS-derived liver regeneration. Additionally, the detection of liver function and functional genes expression confirmed the immaturity of renascent hepatocytes derived in early stage of ALPPS-derived liver regeneration.CONCLUSION Our study revealed the immaturity of ALPPS-derived proliferation in early regenerative response, which indicated that the volumetric assessment overestimated the functional proliferation. This could be convincing evidence that the stage Ⅱ of ALPPS should be performed prudently in patients with marginally adequate f LR, as the ALPPS-derived proliferation in volume lags behind the functional regeneration.