IL-30 (IL27p28) attenuates liver fibrosis through inducing NKG2D-rae1 interaction between NKT and activated hepatic stellate cells in mice

IL-17 enhances oxidative stress in hepatocytes through Nrf2/keap1 signal pathway activation

Hepatic disease is common worldwide. As apoptosis of hepatocytes is a hallmark of hepatic disease, strategies targeting apoptosis are an effective way to prevent and treat the disease. Oxidative stress is a classic pathway of apoptosis. Increased expression of IL-17 has been found in diverse human liver diseases. The aim of this research was to investigate whether the function of IL-17 influenced hepatocyte-induced H₂O₂. We found that the expression of IL-17 was enhanced in hepatocyte-induced H₂O₂ and that IL-17 was down-regulated by siRNA. A TUNEL assay showed that apoptosis was decreased in ΔIL-17-mutant hepatocyte-induced H₂O₂. Additionally, the ratio of Bax/Bcl-2 was decreased in ΔIL-17-mutant hepatocyte-induced H₂O₂. Finally, Nrf2/keap1 signal pathway was analyzed, the expression of Nrf2 and keap1 was decreased in ΔIL-17-mutant hepatocyte-induced H₂O₂. These results suggest that oxidative stress-induced apoptosis was induced and that IL-17 could enhance oxidative stress-induced apoptosis by the Nrf2/keap1 signal pathway in hepatocytes.

Critical Contribution of NK Group 2 Member D Expressed on Invariant Natural Killer T Cells in Concanavalin A-Induced Liver Hepatitis in Mice

Natural killer group 2D (NKG2D) is a well-characterized activating receptor expressed on many immune cells, including invariant natural killer T (iNKT) cells. These cells were shown to be responsible of liver injury in the model of concanavalin A (Con A)-induced hepatitis, considered to be an experimental model of human autoimmune hepatitis. In this study, we investigated whether NKG2D plays a role in the hepatitis induced by iNKT cell-mediated immune response to Con A. By using killer cell lectin-like receptor subfamily K, member 1 deficient (Klrk1^−/−) mice, we found that the absence of NKG2D reduced the hepatic injury upon Con A administration. This was not due to an intrinsic functional defect of NKG2D-deficient iNKT cells as mice missing NKG2D have normal distribution and function of iNKT cells. Furthermore, increased resistance to Con A-induced hepatitis was confirmed using neutralizing anti-NKG2D antibodies. The reduced pathogenic effect of Con A in the absence of NKG2D correlates with a reduction in pathogenic cytokine production and FAS-Ligand (FAS-L) expression by iNKT cells. We also found that Con A administration led to an increase in the retinoic acid early inducible (RAE-1) surface expression on wild-type hepatocytes. Finally, we found that Con A has no direct action on FAS-L expression or cytokine production by iNKT cells and thus propose that NKG2D-L expression on stressed hepatocytes promote cytotoxic activity of iNKT cells via its interaction with NKG2D contributing to hepatic injury. In conclusion, our results highlight NKG2D as an essential receptor required for the activation of iNKT cells in Con A-induced hepatitis and indicate that it represents a potential drug target for prevention of autoimmune hepatitis.

Blocking follistatin-like 1 attenuates liver fibrosis in mice by regulating transforming growth factor-beta signaling

AIM

To elucidate the effect of inhibiting follistatin-like 1 on liver fibrosis and activation of hepatic stellate cells in mice.

METHODS

We generated a follistatin-like 1 neutralizing antibody that can inhibit TGF-β 1-induced expression of collagen1α1 in primary mouse liver fibroblasts. All of the mice in our study were induced with carbon tetrachloride and thioacetamide. In addition, primary hepatic stellate cells from mice were isolated from fresh livers using density gradient separation. The degree and extent of fibrosis in mouse livers from the different groups were evaluated by Sirius Red and Masson staining. The effect of the follistatin-like 1 neutralizing antibody on proliferation and migration of hepatic stellate cells was detected using CCK-8 and Transwell assays, respectively.

RESULTS

Expression of follistatin-like 1 in human cirrhotic liver tissue was higher than that in normal liver tissue. Blocking follistatin-like 1 resulted in a delay of primary hepatic stellate cell activation and down-regulation of the migratory capacity of hepatic stellate cells. Blocking follistatin-like 1 also down-regulated TGF-beta signaling in primary hepatic stellate cells from mice. Finally, inhibition of follistatin-like 1 attenuated liver fibrosis and liver function damage in vivo.

CONCLUSIONS

Inhibiting follistatin-like 1 attenuates liver fibrosis and causes a delay in hepatic stellate cell activation. The effect of follistatin-like 1 on liver fibrosis is mainly attributed to its role in regulating TGF-beta signaling.

Interleukin-30/IL27p28 Shapes Prostate Cancer Stem-like Cell Behavior and Is Critical for Tumor Onset and Metastasization

Prostate cancer stem-like cells (PCSLC) are believed to be responsible for prostate cancer onset and metastasis. Autocrine and microenvironmental signals dictate PCSLC behavior and patient outcome. In prostate cancer patients, IL30/IL27p28 has been linked with tumor progression, but the mechanisms underlying this link remain mostly elusive. Here, we asked whether IL30 may favor prostate cancer progression by conditioning PCSLCs and assessed the value of blocking IL30 to suppress tumor growth. IL30 was produced by PCSLCs in human and murine prostatic intraepithelial neoplasia and displayed significant autocrine and paracrine effects. PCSLC-derived IL30 supported PCSLC viability, self-renewal and tumorigenicity, expression of inflammatory mediators and growth factors, tumor immune evasion, and regulated chemokine and chemokine receptor genes, primarily via STAT1/STAT3 signaling. IL30 overproduction by PCSLCs promoted tumor onset and development associated with increased proliferation, vascularization, and myeloid cell recruitment. Furthermore, it promoted PCSLC dissemination to lymph nodes and bone marrow by upregulating the CXCR5/CXCL13 axis, and drove metastasis to lungs through the CXCR4/CXCL12 axis. These mechanisms were drastically hindered by IL30 knockdown or knockout in PCSLCs. Collectively, these results mark IL30 as a key driver of PCSLC behavior. Targeting IL30 signaling may be a potential therapeutic strategy against prostate cancer progression and recurrence.Significance: IL30 plays an important role in regulating prostate cancer stem-like cell behavior and metastatic potential, therefore targeting this cytokine could hamper prostate cancer progression or recurrence. Cancer Res; 78(10); 2654-68. ©2018 AACR.

Peripheral blood lymphocyte subset levels differ in patients with hepatocellular carcinoma

We investigated the levels of target lymphocyte subsets in peripheral blood lymphocyte samples from patients with hepatocellular carcinoma (HCC). A total of 715 high-risk patients with primary HCC were recruited in Guangxi, China as the case group. The control group included 100 patients who received health examinations at the same hospital during the same period. Fasting elbow venous blood (10 mL) was collected from each participant, and flow cytometry was used to detect the levels of NK cells and CD3⁺, CD4⁺ and CD19⁺ T cells in peripheral blood samples. All included patients with prmary HCC were treated by surgical resection, and followed up for one year. The levels of CD19⁺ and NK cells were lower in cases than in controls (both P < 0.05). In addition, the level of CD8⁺ cells was greater in the case group than in the control group (P < 0.05). In the high-HCC-risk population, CD8⁺, CD19⁺ and NK cell levels all differed between male and female patients, patients in TNM stages I–II and stages III–IV, patients with and without extrahepatic metastasis, and patients with and without HBV infection (all P < 0.05). After follow-up, detected recurrence and survival rate was 33.71% and 83.64%, respectively. CD8⁺ levels was reduced following surgical resection, whereas the levels of CD19⁺ and NK cells were increased (all P < 0.05). In conclusion, altered levels of CD8⁺, CD19⁺ and NK cell levels may be used as reference values for monitoring immune function in certain populations with high HCC risk, and as potential evidence for the clinical diagnosis and treatment of HCC.

Histological expression of methionine adenosyl transferase (MAT) 2A as a post-surgical prognostic surrogate in patients with hepatocellular carcinoma

BACKGROUND AND OBJECTIVES

Deregulation of methionine adenosyltransferase (MAT) is involved in hepatocarcinogenesis. This study aimed to investigate the prognostic implications of the level of histological MAT1A and MAT2A in patients with resected hepatocellular carcinoma (HCC).

METHODS

A total of 210 patients with HCC who underwent curative resection between 2004 and 2011 were included. The levels of MAT proteins were immunohistochemically measured.

RESULTS

MAT1A and MAT2A were over-expressed in 134 (63.8%) and 124 (59.1%) of the 210 tumor tissues, respectively. Up-regulation of tumoral MAT1A was independently associated with male gender, and inversely related to tumors >5 cm (adjusted odds ratios [OR] 2.59, P = 0.008, and OR 0.44, P = 0.012, respectively). Enhanced MAT2A expression was significantly related to age ≥60 years and serum AFP >200 ng/mL (OR 0.51, P = 0.030; and OR 2.65, P = 0.003; respectively). Tumoral MAT2A over-expression independently predicted an increased rate of recurrence within 1 year after hepatectomy (adjusted hazard ratio [HR] 2.45, P = 0.012), but that was not the case for MAT1A expression (HR 0.90, P = 0.744). High MAT2A was also an independent predictor of early recurrence (HR 2.54, P = 0.034) in the subset of patients without microvascular invasion (n = 155).

CONCLUSIONS

Over-expression of MAT2A in HCC may be a useful biomarker for predicting and monitoring tumor recurrence, especially early after hepatic resection.

The Injury-Related Activation of Hedgehog Signaling Pathway Modulates the Repair-Associated Inflammation in Liver Fibrosis

Liver fibrosis is a wound healing response initiated by inflammation responding for different iterative parenchymal damages caused by diverse etiologies. Immune cells, which exert their ability of either inducing injury or promoting repair, have been regarded as crucial participants in the fibrogenic response. A characteristic feature of the fibrotic microenvironment associated with chronic liver injury is aberrant activation of hedgehog (Hh) signaling pathway. Growing evidence from a number of different studies in vivo and in vitro has indicated that immune-mediated events involved in liver fibrogenesis are regulated by Hh signaling pathway. In this review, we emphasize the impacts of injury-activated Hh signaling on liver fibrogenesis through modulating repair-related inflammation and focus on the regulatory action of aberrant Hh signaling on repair-related inflammatory responses mediated by hepatic classical and non-classical immune cell populations in the progression of liver fibrosis. Moreover, we also assess the potentiality of Hh pathway inhibitors as good candidates for anti-fibrotic therapeutic agents because of their immune regulation actions for fibrogenic liver repair. The identification of immune-modulatory mechanisms of Hh signaling pathway underlying the fibrotic process of chronic liver diseases might provide a basis for Hh-centered therapeutic strategies for liver fibrosis.

Mesenchymal stem cells attenuate liver fibrosis by suppressing Th17 cells - an experimental study

This study investigates molecular and cellular mechanisms involved in mesenchymal stem cell (MSC)-mediated modulation of IL-17 signaling during liver fibrosis. Mice received CCl₄ (1 μl/g intraperitoneally) twice/week for 1 month. MSCs (1 × 10⁶ ), or MSC-conditioned medium (MSC-CM), were intravenously injected 24 h after CCl₄ and on every 7th day. Liver fibrosis was determined by macroscopic examination, histological analysis, Sirius red staining, and RT-PCR. Serum levels of cytokines, indoleamine 2,3-dioxygenase (IDO), and kynurenine were determined by ELISA. Flow cytometry was performed to identify liver-infiltrated cells. In vitro, CD4⁺ T cells were stimulated and cultured with MSCs. 1-methyltryptophan was used for inhibition of IDO. MSCs significantly attenuated CCl₄ -induced liver fibrosis by decreasing serum levels of inflammatory IL-17, increasing immunosuppressive IL-10, IDO, and kynurenine, reducing number of IL-17 producing Th17 cells, and increasing percentage of CD4⁺ IL-10⁺ T cells. Injection of MSC-CM resulted with attenuated fibrosis accompanied with the reduced number of Th17 cells in the liver and decreased serum levels of IL-17. MSC-CM promoted expansion of CD4⁺ FoxP3⁺ IL-10⁺ T regulatory cells and suppressed proliferation of Th17 cells. This phenomenon was completely abrogated in the presence of IDO inhibitor. MSCs, in IDO-dependent manner, suppress liver Th17 cells which lead to the attenuation of liver fibrosis.

Protective role of NKT cells and macrophage M2-driven phenotype in bleomycin-induced pulmonary fibrosis

Pulmonary fibrosis is a result of an abnormal wound healing in lung tissue triggered by an excessive accumulation of extracellular matrix proteins, loss of tissue elasticity, and debit of ventilatory function. NKT cells are a major source of Th1 and Th2 cytokines and may be crucial in the polarization of M1/M2 macrophages in pulmonary fibrogenesis. Although there appears to be constant scientific progress in that field, pulmonary fibrosis still exhibits no current cure. From these facts, we hypothesized that NKT cells could influence the development of pulmonary fibrosis via modulation of macrophage activation. Wild type (WT) and NKT type I cell-deficient mice (Jα18^-/-) were subjected to the protocol of bleomycin-induced pulmonary fibrosis with or without treatment with NKT cell agonists α-galactosylceramide and sulfatide. The participation of different cell populations, collagen deposition, and protein levels of different cytokines involved in inflammation and fibrosis was evaluated. The results indicate a benign role of NKT cells in Jα18^-/- mice and in wild-type α-galactosylceramide-sulfatide-treated groups. These animals presented lower levels of collagen deposition, fibrogenic molecules such as TGF-β and vimentin and improved survival rates. In contrast, WT mice developed a Th2-driven response augmenting IL-4, 5, and 13 protein synthesis and increased collagen deposition. Furthermore, the arginase-1 metabolic pathway was downregulated in wild-type NKT-activated and knockout mice indicating lower activity of M2 macrophages in lung tissue. Hence, our data suggest that NKT cells play a protective role in this experimental model by down modulating the Th2 milieu, inhibiting M2 polarization and finally preventing fibrosis.

IL6-mediated inflammatory loop reprograms normal to epithelial-mesenchymal transition+ metastatic cancer stem cells in preneoplastic liver of transforming growth factor beta-deficient β2-spectrin+/- mice

Hepatocellular carcinoma (HCC) is the second-leading cause of cancer-related deaths worldwide with a poor survival rate. As many as 40% of HCCs are clonal, with alteration of key tumor-suppressor pathways in stem cells as the primary cause of HCC initiation. However, mechanisms that generate metastatic stem cells in preneoplastic liver tissue are not well understood. We hypothesized that chronic inflammation is a major driver of the transformation of genetically defective liver stem cells (LSCs) into highly metastatic liver cancer cells in premalignant liver tissue. We developed models of chronic inflammation in wild-type (WT) and β2-spectrin (β2SP)^+/- (SPTBN1) mice. CD133⁺ LSCs derived from preneoplastic livers of β2SP^+/- mice treated with interleukin-6 (pIL6; ^IL6 β2SP^+/- LSCs) were highly tumorigenic and metastatic, whereas those derived from WT mice treated with pIL6 (^IL6 WT LSCs) had significantly less proliferation and no tumorigenic properties. ^IL6 β2SP^+/- LSCs not only exhibited nuclear localization of Twist and Slug, markers of epithelial-mesenchymal transition (EMT), but also constitutive activation of nuclear factor kappa B (NFκB; RELA). Knockdown of NFκB decreased the EMT phenotypes and metastatic capacity of these cells. NFκB in ^IL6 β2SP^+/- LSCs was activated by transforming growth factor β (TGFβ)-activated kinase 1 (TAK1; MAP3K7), which is associated with poor survival in HCC and interleukin-6 (IL6) expression. The amount of constitutively activated NFκB increased dramatically from normal to cirrhotic to HCC tissues from human patients.

CONCLUSION

IL6-mediated inflammation programs constitutive activation of the TAK1-NFκB signaling cascade in CD133⁺ LSCs, and this program interacts with deficient TGFβ signaling, thereby accelerating the transformation of normal LSCs to metastatic cancer stem cells (mCSCs). Indeed, this study delineates the development of EMT-positive mCSCs in HCC-free liver tissue upon chronic inflammation. (Hepatology 2017;65:1222-1236).

Mechanisms and treatment of liver fibrosis

Hepatic fibrosis is a characteristic consequence of multiple chronic liver injuries. However, there are currently no specific drugs that can effectively reverse or prevent liver fibrosis progression. Liver fibrosis is a complex pathological process attributable to a variety of cytokines and molecular pathways. Therefore, further exploring the cellular and molecular mechanisms of liver fibrosis, unearthing specific anti-fibrosis targeted therapies and translation of the potential findings into clinical treatment are of great significance.

Rosmarinic acid counteracts activation of hepatic stellate cells via inhibiting the ROS-dependent MMP-2 activity: Involvement of Nrf2 antioxidant system

Recently, oxidative stress is involved in hepatofibrogenesis. Matrix metalloproteinase-2 (MMP-2) is required for activation of hepatic stellate cells (HSCs) in response to reactive oxygen species (ROS). This study was designed to explore the hypothesis that the inhibitory effect of rosmarinic acid (RA) on HSCs activation might mainly result from its antioxidant capability by increasing the synthesis of glutathione (GSH) involved in nuclear factor kappa B (NF-κB)-dependent inhibition of MMP-2 activity. Here, we demonstrate that RA reverses activated HSCs to quiescent cells. Concomitantly, RA inhibits MMP-2 activity. RNA interference-imposed knockdown of NF-κB abolished down-regulation of MMP-2 by RA. RA-mediated inactivation of NF-κB could be blocked by the diphenyleneiodonium chloride (DPI; a ROS inhibitor). Conversely, transfection of dominant-negative (DN) mutant of extracellular signal-regulated kinases 2 (ERK2), c-Jun N-terminal kinase 1 (JNK1), or p38α kinase had no such effect. Simultaneously, RA suppresses ROS generation and lipid peroxidation (LPO) whereas increases cellular GSH in HSC-T6 cells. Furthermore, RA significantly increased antioxidant response element (ARE)-mediated luciferase activity, nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) and catalytic subunits from glutamate cysteine ligase (GCLc) expression, but not modulatory subunits from GCL (GCLm). RA-mediated up-regulation of GClc is inhibited by the shRNA-induced Nrf2 knockdown. The knocking down of Nrf2 or buthionine sulfoximine (a GCL inhibitor) abolished RA-mediated inhibition of ROS. Collectively, these results provide novel insights into the mechanisms of RA as an antifibrogenic candidate in the prevention and treatment of liver fibrosis.

Modulation of hepatic stellate cells and reversibility of hepatic fibrosis

Hepatic fibrosis (HF) is the pathological component of a variety of chronic liver diseases. Hepatic stellate cells (HSC) are the main collagen-producing cells in the liver and their activation promotes HF. If HSC activation and proliferation can be inhibited, HF occurrence and development can theoretically be reduced and even reversed. Over the past ten years, a number of studies have addressed this process, and here we present a review of HSC modulation and HF reversal.

Hepatic stellate cell interferes with NK cell regulation of fibrogenesis via curcumin induced senescence of hepatic stellate cell

Hepatic fibrosis, a common scarring response to various forms of chronic liver injury, is a precursor to cirrhosis and liver cancer. During liver fibrosis, hepatic stellate cells (HSCs) initially activate and proliferate, which are responsible for the secretion of extracellular matrix components. However, these cells eventually senesce and are cleared by natural killer (NK) cells. Our previous researches have shown that the natural product curcumin could promote the senescence of activated HSC. In this study, we investigated how NK cells target senescent HSC and assessed the effect of this process on liver fibrosis. We found that senescent HSC induced by curcumin are susceptible to NK cells killing, due to the increased expression of NK cell activating ligand major histocompatibility complex class I chain-related genes A (MICA) and UL16-binding proteins 2 (ULBP2), but not Poliovirus Receptor (PVR). Further studies displayed that the interaction between NK cells and senescent LX2 cells stimulated granule exocytosis. Moreover, the inhibition of granule exocytosis weakened the cytotoxicity of NK cells and promoted the accumulation of senescent LX2 cells. Therefore, these aggregated data indicated that NK cells mediated clearance of senescent LX2 cells and granule exocytosis could play a protective role in the improvement of liver fibrosis.

Liver fibrosis and hepatic stellate cells: Etiology, pathological hallmarks and therapeutic targets

Liver fibrosis is a reversible wound-healing process aimed at maintaining organ integrity, and presents as the critical pre-stage of liver cirrhosis, which will eventually progress to hepatocellular carcinoma in the absence of liver transplantation. Fibrosis generally results from chronic hepatic injury caused by various factors, mainly viral infection, schistosomiasis, and alcoholism; however, the exact pathological mechanisms are still unknown. Although numerous drugs have been shown to have antifibrotic activity in vitro and in animal models, none of these drugs have been shown to be efficacious in the clinic. Importantly, hepatic stellate cells (HSCs) play a key role in the initiation, progression, and regression of liver fibrosis by secreting fibrogenic factors that encourage portal fibrocytes, fibroblasts, and bone marrow-derived myofibroblasts to produce collagen and thereby propagate fibrosis. These cells are subject to intricate cross-talk with adjacent cells, resulting in scarring and subsequent liver damage. Thus, an understanding of the molecular mechanisms of liver fibrosis and their relationships with HSCs is essential for the discovery of new therapeutic targets. This comprehensive review outlines the role of HSCs in liver fibrosis and details novel strategies to suppress HSC activity, thereby providing new insights into potential treatments for liver fibrosis.

Liver fibrosis and hepatic stellate cells: Etiology, pathological hallmarks and therapeutic targets

Liver fibrosis is a reversible wound-healing process aimed at maintaining organ integrity, and presents as the critical pre-stage of liver cirrhosis, which will eventually progress to hepatocellular carcinoma in the absence of liver transplantation. Fibrosis generally results from chronic hepatic injury caused by various factors, mainly viral infection, schistosomiasis, and alcoholism; however, the exact pathological mechanisms are still unknown. Although numerous drugs have been shown to have antifibrotic activity in vitro and in animal models, none of these drugs have been shown to be efficacious in the clinic. Importantly, hepatic stellate cells (HSCs) play a key role in the initiation, progression, and regression of liver fibrosis by secreting fibrogenic factors that encourage portal fibrocytes, fibroblasts, and bone marrow-derived myofibroblasts to produce collagen and thereby propagate fibrosis. These cells are subject to intricate cross-talk with adjacent cells, resulting in scarring and subsequent liver damage. Thus, an understanding of the molecular mechanisms of liver fibrosis and their relationships with HSCs is essential for the discovery of new therapeutic targets. This comprehensive review outlines the role of HSCs in liver fibrosis and details novel strategies to suppress HSC activity, thereby providing new insights into potential treatments for liver fibrosis.

Expanding Diversity in Molecular Structures and Functions of the IL-6/IL-12 Heterodimeric Cytokine Family

The interleukin (IL)-6/IL-12 family cytokines have pleiotropic functions and play critical roles in multiple immune responses. This cytokine family has very unique characteristics in that they comprise two distinct subunits forming a heterodimer and each cytokine and receptor subunit shares with each other. The members of this cytokine family are increasing; currently, there are more than six cytokines, including the tentatively named cytokines IL-Y (p28/p40), IL-12 (p35/p40), IL-23 (p19/p40), IL-27 [p28/Epstein–Barr virus-induced protein 3 (EBI3)], IL-35 (p35/EBI3), and IL-39 (p19/EBI3). This family of cytokines covers a very broad range of immune responses, including pro-inflammatory responses, such as helper T (Th)1, Th2, and Th17, to anti-inflammatory responses, such as regulatory T (Treg) cells and IL-10-producing Treg cells. IL-12 is the first member of this family, and IL-12, IL-23, and IL-27 are mainly produced by activated antigen-presenting cells, such as dendritic cells and macrophages. IL-12 plays a critical role in the promotion of Th1 immune responses by inducing interferon-γ production to combat pathogens and malignant tumors. IL-23 induces IL-17 production and is necessary to maintain pathogenic Th17 cells that cause inflammatory and autoimmune diseases. IL-27 was initially reported to play a critical role in promotion of Th1 differentiation; however, subsequent studies revealed that IL-27 has broader stimulatory and inhibitory roles by inducing IL-10-producing Treg cells. IL-35 is produced by forkhead box P3⁺ Treg cells and activated B cells and has immunosuppressive functions to maintain immune tolerance. The most recently identified cytokine, IL-39, is produced by activated B cells and has pro-inflammatory functions. The cytokine tentatively named IL-Y seems to have anti-inflammatory functions by inhibiting Th1 and Th17 differentiation. In addition, individual cytokine subunits were also shown to have self-standing activities. Thus, promiscuity within the IL-6/IL-12 family cytokines complicates structural and functional clarification and assignment of individual cytokines. A better understanding of the recent advances and expanding diversity in molecular structures and functions of the IL-6/IL-12 family cytokines could allow the creation of novel therapeutic strategies by using them as tools and targeted molecules.

Dual Roles of IFN-γ and IL-4 in the Natural History of Murine Autoimmune Cholangitis: IL-30 and Implications for Precision Medicine

Primary biliary cirrhosis (PBC) is a progressive autoimmune liver disease with a long natural history. The pathogenesis of PBC is thought to be orchestrated by Th1 and/or Th17. In this study, we investigated the role of CD4⁺ helper T subsets and their cytokines on PBC using our previous established murine model of 2-OA-OVA immunization. We prepared adeno-associated virus (AAV)-IFN-γ and AAV-IL-4 and studied their individual influences on the natural history of autoimmune cholangitis in this model. Administration of IFN-γ significantly promotes recruitment and lymphocyte activation in the earliest phases of autoimmune cholangitis but subsequently leads to downregulation of chronic inflammation through induction of the immunosuppressive molecule IL-30. In contrast, the administration of IL-4 does not alter the initiation of autoimmune cholangitis, but does contribute to the exacerbation of chronic liver inflammation and fibrosis. Thus Th1 cells and IFN-γ are the dominant contributors in the initiation phase of this model but clearly may have different effects as the disease progress. In conclusion, better understanding of the mechanisms by which helper T cells function in the natural history of cholangitis is essential and illustrates that precision medicine may be needed for patients with PBC at various stages of their disease process.

Inhibition of YAP signaling contributes to senescence of hepatic stellate cells induced by tetramethylpyrazine

Accumulating evidence indicates that hepatic stellate cells (HSCs) are the central mediators and major effectors in the development of hepatic fibrosis. It is well-known that regulation of cell proliferation and apoptosis are potential strategies to block the activation of HSCs. Recently, several studies have revealed that induction of HSC senescence could prevent and cure the liver fibrosis. In our previous work, we have demonstrated that the natural product tetramethylpyrazine (TMP) could inhibit the activation of HSCs and ameliorate hepatic fibrosis. The aim of this study was to identify a new role of TMP in the regulation of activated HSC senescence and to elucidate the underlying mechanisms. In this study, our data showed that TMP could promote HSC senescence in vivo and in vitro. Moreover, TMP affected the cell cycle and telomerase activity. We further demonstrated that P53 siRNA or P53 pharmacological inhibitor PFT-α abrogated the TMP-induced HSC senescence in vitro. Meanwhile, similar results were obtained in vivo. Further studies indicated that TMP promoted the expression of P53 through a YAP inhibition-dependent mechanism. Moreover, silencing YAP enhanced TMP induction of activated HSC senescence. Collectively, our results suggested that TMP inhibited the activation of HSCs by inducing senescence and had therapeutic implication for the treatment of liver fibrosis.

The fibrolytic potentials of vitamin D and thymoquinone remedial therapies: insights from liver fibrosis established by CCl4 in rats

Background

Vitamin D (VitD) and thymoquinone (TQ) are nutraceutical agents with well-known immunomodulatory and hepatoprotective properties. This study measured whether VitD and TQ, individually or combined, could have direct fibrolytic activities and/or enhanced performance during remedial treatment of liver fibrosis established by CCl4 in rats.

Methods

Eighty five male Wistar rats were used as 10 negative controls (NC) and the remainders were distributed equally into 5 groups: short (S-PC) and long (L-PC) positive controls, TQ, VitD and VitD/TQ groups. CCl4 was injected for 7 weeks followed by a week of no intervention. TQ and/or VitD were given orally (3 days/week) from week 9 and euthanasia was at week 17 for all groups except the S-PC was at week 9. Following histopathological and digital image analyses, TGF-β1, IL-6, IL-10, IL-22 and MMP-9 were measured by ELISA in liver homogenates while the corresponding cytokine receptors were measured by immunohistochemistry. The mRNA expressions of all molecules were measured by quantitative RT-PCR.

Results

Fibrosis was evident in both PC-groups and was significantly more advanced in the L-PC than S-PC, reaching to cirrhosis. The concentrations of TGF-β1, IL-6, IL-22 and their receptors were significantly higher (P < 0.05) simultaneously with significantly lower (P < 0.05) concentrations of MMP-9, IL-10 and IL-10 receptors in the S-PC and L-PC than the NC-group. TQ and VitD monotherapies showed significantly less fibrosis than L-PC but were similar to S-PC. Both remedial monotherapies also resulted in significant decreases of TGF-β1, IL-6, IL-22 and their receptors together with significant increases of MMP-9 and IL-10 system compared with S-PC and L-PC groups. Interestingly, dual therapy resulted in the most significant improvement in fibrosis score and index, yet was significantly higher (P < 0.05) than the NC-group, and concurred with the utmost significant restorations of all candidate genes and proteins.

Conclusions

VitD and TQ exhibited comparable anti-fibrogenic effects and modulated several pro- and anti-fibrotic mediators. Additionally, VitD/TQ dual therapy alleviated the previously established liver fibrosis simultaneously with significantly enhanced actions at the molecular level. More studies are required to explorer the therapeutic value of TQ and VitD against liver fibrosis in human.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-016-1040-4) contains supplementary material, which is available to authorized users.

ω-3 PUFAs ameliorate liver fibrosis and inhibit hepatic stellate cells proliferation and activation by promoting YAP/TAZ degradation

Elevated levels of the transcriptional regulators Yes-associated protein (YAP) and transcriptional coactivators with PDZ-binding motif (TAZ), key effectors of the Hippo pathway, have been shown to play essential roles in controlling liver cell fate and the activation of hepatic stellate cells (HSCs). The dietary intake of omega-3 polyunsaturated fatty acids (ω-3 PUFAs) has been positively associated with a number of health benefits including prevention and reduction of cardiovascular diseases, inflammation and cancers. However, little is known about the impact of ω-3 PUFAs on liver fibrosis. In this study, we used CCl₄-induced liver fibrosis mouse model and found that YAP/TAZ is over-expressed in the fibrotic liver and activated HSCs. Fish oil administration to the model mouse attenuates CCl₄-induced liver fibrosis. Further study revealed that ω-3 PUFAs down-regulate the expression of pro-fibrogenic genes in activated HSCs and fibrotic liver, and the down-regulation is mediated via YAP, thus identifying YAP as a target of ω-3 PUFAs. Moreover, ω-3 PUFAs promote YAP/TAZ degradation in a proteasome-dependent manner. Our data have identified a mechanism of ω-3 PUFAs in ameliorating liver fibrosis.

Interleukin-30 (IL27p28) alleviates experimental sepsis by modulating cytokine profile in NKT cells

BACKGROUND & AIMS

Sepsis is an acute systemic inflammatory response to infection associated with high patient mortality (28-40%). We hypothesized that interleukin (IL)-30, a novel cytokine protecting mice against liver injury resulting from inflammation, would generate a protective effect against systemic inflammation and sepsis-induced death.

METHODS

Sepsis was induced by lipopolysaccharide (LPS) or cecal ligation and puncture (CLP). The inhibitory effects of IL-30 on septic inflammation and associated therapeutic effects were determined in wild-type, IL30 (p28)(-/-), IL10(-/-), and CD1d(-/-) mice.

RESULTS

Mice treated with pIL30 gene therapy or recombinant IL-30 protein (rIL30) were protected from LPS-induced septic shock or CLP-induced polymicrobial sepsis and showed markedly less liver damage and lymphocyte apoptosis than control septic mice. The resulting reduction in mortality was mediated through attenuation of the systemic pro-inflammatory response and augmentation of bacterial clearance. Mice lacking IL-30 were more sensitive to LPS-induced sepsis. Natural killer-like T cells (NKT) produced much higher levels of IL-10 and lower levels of interferon-gamma and tumor necrosis factor-alpha in IL-30-treated septic mice than in control septic mice. Likewise, deficiency in IL-10 or NKT cells abolished the protective role of IL-30 against sepsis. Furthermore, IL-30 induced IL-10 production in purified and LPS-stimulated NKT cells. Blocking IL-6R or gp130 inhibited IL-30 mediated IL-10 production.

CONCLUSIONS

IL-30 is important in modulating production of NKT cytokines and subsequent NKT cell-mediated immune regulation of other cells. Therefore, IL-30 has a role in prevention and treatment of sepsis via modulation of cytokine production by NKT.

Natural killer T cells in liver injury, inflammation and cancer

The liver is an organ that has the largest amount of natural killer T(NKT) cells, which play critical roles in the pathogenesis of liver diseases. In this article, the authors summarize recent findings about the roles of NKT cells in liver injury, inflammation, fibrosis, regeneration and cancer. In brief, NKT cells accelerate liver injury by producing pro-inflammatory cytokines and directly killing hepatocytes. NKT cells are involved in complex roles in liver fibrogenesis. For instance, NKT cells inhibit liver fibrosis via suppressing hepatic stellate cell activation and can also promote liver fibrosis via enhancing liver inflammation and injury. Inactivated or weakly activated NKT cells play a minimal role in controlling liver regeneration, whilst activated NKT cells have an inhibitory effect on liver regeneration. In liver cancer, NKT cells play both pro-tumor and anti-tumor roles in controlling tumor progress.

Mutant p53 in concert with an interleukin-27 receptor alpha deficiency causes spontaneous liver inflammation, fibrosis, and steatosis in mice

The cellular and molecular etiology of unresolved chronic liver inflammation remains obscure. Whereas mutant p53 has gain-of-function properties in tumors, the role of this protein in liver inflammation is unknown. Herein, mutant p53(R172H) is mechanistically linked to spontaneous and sustained liver inflammation and steatosis when combined with the absence of interleukin-27 (IL27) signaling (IL27RA), resembling the phenotype observed in nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) patients. Indeed, these mice develop, with age, hepatocyte necrosis, immune cell infiltration, fibrosis, and micro- and macrosteatosis; however, these phenotypes are absent in mutant p53(R172H) or IL27RA(-/-) mice. Mechanistically, endothelin A receptor (ETAR)-positive macrophages are highly accumulated in the inflamed liver, and chemical inhibition of ETAR signaling reverses the observed phenotype and negatively regulates mutant p53 levels in macrophages.

CONCLUSION

The combination of mutant p53 and IL27RA(-/-) causes spontaneous liver inflammation, steatosis, and fibrosis in vivo, whereas either gene alone in vivo has no effects on the liver.

Therapeutic Effect of Losartan, an Angiotensin II Type 1 Receptor Antagonist, on CCl₄-Induced Skeletal Muscle Injury

TGF-β1 is known to inhibit muscle regeneration after muscle injury. However, it is unknown if high systemic levels of TGF-β can affect the muscle regeneration process. In the present study, we demonstrated the effect of a CCl₄ intra-peritoneal injection and losartan (an angiotensin II type 1 receptor antagonist) on skeletal muscle (gastrocnemius muscle) injury and regeneration. Male C57BL/6 mice were grouped randomly as follows: control (n = 7), CCl₄-treatment group (n = 7), and CCl₄ + losartan treatment group (n = 7). After CCl₄ treatment for a 16-week period, the animals were sacrificed and analyzed. The expression of dystrophin significantly decreased in the muscle tissues of the control group, as compared with that of the CCl₄ + losartan group (p < 0.01). p(phospho)-Smad2/3 expression significantly increased in the muscles of the control group compared to that in the CCl₄ + losartan group (p < 0.01). The expressions of Pax7, MyoD, and myogenin increased in skeletal muscles of the CCl₄ + losartan group compared to the corresponding levels in the control group (p < 0.01). We hypothesize that systemically elevated TGF-β1 as a result of CCl₄-induced liver injury causes skeletal muscle injury, while losartan promotes muscle repair from injury via blockade of TGF-β1 signaling.

Complications Requiring Hospital Admission and Causes of In-Hospital Death over Time in Alcoholic and Nonalcoholic Cirrhosis Patients

BACKGROUND/AIMS

Data on the epidemiology of alcoholic cirrhosis, especially in Asian countries, are limited. We compared the temporal evolution of patterns of alcoholic and nonalcoholic cirrhosis over the last decade.

METHODS

We retrospectively examined the inpatient datasets of five referral centers during 2002 and 2011. The study included patients who were admitted due to specific complications of liver cirrhosis. We compared the causes of hospital admissions and in-hospital deaths between patients with alcoholic and nonalcoholic cirrhosis.

RESULTS

Among the included 2,799 hospitalizations (2,165 patients), 1,496 (1,143 patients) were from 2002, and 1,303 (1,022 patients) were from 2011. Over time, there was a reduction in the rate of hepatic encephalopathy (HE) as a cause of hospitalization and an increase in the rate of hepatocellular carcinoma. Deaths that were attributable to HE or spontaneous bacterial peritonitis (SBP) significantly decreased, whereas those due to hepatorenal syndrome (HRS) significantly increased over time in patients with alcoholic cirrhosis. However, in patients with nonalcoholic cirrhosis, hepatic failure and HRS remained the principal causes of in-hospital death during both time periods.

CONCLUSIONS

The major causes of in-hospital deaths have evolved from acute cirrhotic complications, including HE or SBP to HRS in alcoholic cirrhosis, whereas those have remained unchanged in nonalcoholic cirrhosis during the last decade.

Impact of OAS1 Exon 7 rs10774671 Genetic Variation on Liver Fibrosis Progression in Egyptian HCV Genotype 4 Patients

The aim of this study was to assess the impact of genetic variants of oligoadenylate synthetase 1 (OAS1) single-nucleotide polymorphism (SNP) rs10774671 at the exon 7 splice acceptor site on liver fibrosis progression and hepatitis C virus (HCV) outcome in Egyptian HCV genotype 4 patients. In this study, 195 subjects were enrolled; 60 controls and 135 chronic HCV genotype 4 patients with different fibrosis grades. All subjects were genotyped for OAS1 SNP rs10774671 polymorphism by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. There was an increasing trend of liver fibrosis progression as 52.9% GG, 73.6% GA, and 83.3% AA genotypes were detected in late fibrosis patients (p = 0.025). The AA genotype was higher in the late fibrosis group than in the early fibrosis group (83.3% vs. 16.7%) (p = 0.001). The A allele was significantly affecting the liver fibrosis progression rate, more than the G allele (p = 0.001). The multivariate analysis showed that the OAS1 GA and AA genotypes were independent factors associated with liver progression (p = 0.009, odds ratio [OR] 3.467, 95% confidence interval [CI] 1.273-7.584). In addition, the A allele was associated with liver fibrosis progression (p = 0.014, OR 2.525, 95% CI 1.157-4.545). The polymorphism at OAS1 exon 7 rs3741981 might be a potential genetic marker and can be useful in the assessment of liver fibrosis progression and disease outcome in HCV-infected patients.

Drugs of abuse and addiction: A slippery slope toward liver injury

Substances of abuse induce alteration in neurobehavioral symptoms, which can lead to simultaneous exacerbation of liver injury. The biochemical changes of liver are significantly observed in the abused group of people using illicit drugs or drugs that are abused. A huge amount of work has been carried out by scientists for validation experiments using animal models to assess hepatotoxicity in cases of drugs of abuse. The risk of hepatotoxicity from these psychostimulants has been determined by different research groups. Hepatotoxicity of these drugs has been recently highlighted and isolated case reports always have been documented in relation to misuse of the drugs. These drugs induce liver toxicity on acute or chronic dose dependent process, which ultimately lead to liver damage, acute fatty infiltration, cholestatic jaundice, liver granulomas, hepatitis, liver cirrhosis etc. Considering the importance of drug-induced hepatotoxicity as a major cause of liver damage, this review emphasizes on various drugs of abuse and addiction which induce hepatotoxicity along with their mechanism of liver damage in clinical aspect as well as in vitro and in vivo approach. However, the mechanisms of drug-induced hepatotoxicity is dependent on reactive metabolite formation via metabolism, modification of covalent bonding between cellular components with drug and its metabolites, reactive oxygen species generation inside and outside of hepatocytes, activation of signal transduction pathways that alter cell death or survival mechanism, and cellular mitochondrial damage, which leads to alteration in ATP generation have been notified here. Moreover, how the cytokines are modulated by these drugs has been mentioned here.

Melatonin attenuates carbon tetrachloride-induced liver fibrosis via inhibition of necroptosis

We investigated the protective mechanisms of melatonin (MLT) associated with necroptosis signaling and damage-associated molecular patterns, which are mediated by the activation of pattern recognition receptors in liver fibrosis. Rats were given an intraperitoneal injection of carbon tetrachloride (CCl4) dissolved in olive oil (1:3, vol/vol) twice a week (0.5 mL/kg) for 8 weeks. During this period, MLT was administered orally at 2.5, 5, and 10 mg/kg once a day. Chronic CCl4 administration increased hepatic hydroxyproline content and hepatocellular damage. MLT attenuated these increases. The expression levels of transforming growth factor β1 and α-smooth muscle actin that were increased by chronic CCl4 exposure were attenuated by MLT. CCl4 significantly increased receptor-interacting protein 1 (RIP1) expression, the formation of the RIP1 and RIP3 necrosome complex, and the level of mixed lineage kinase domain-like protein in liver tissue, which were attenuated by MLT. MLT also attenuated CCl4-induced increases in serum high-mobility group box 1 (HMGB1) and interleukin 1α, as well as the interaction between HMGB1 receptors for advanced glycation end products (RAGE). The increases in toll-like receptor 4 expression, p38, c-Jun N-terminal kinases phosphorylation, and nuclear factor κB translocation were suppressed by MLT. MLT attenuated the overexpression of RAGE, increased level of early growth response protein 1, and increased messenger RNA level of macrophage inflammatory protein 2. Our findings suggest MLT may prevent liver fibrosis by inhibiting necroptosis-associated inflammatory signaling.

Protective effect of bicyclol against bile duct ligation-induced hepatic fibrosis in rats

AIM: To evaluate the protective effect of bicyclol against bile duct ligation (BDL)-induced hepatic fibrosis in rats.

METHODS: Sprague-Dawley male rats underwent BDL and sham-operated animals were used as healthy controls. The BDL rats were divided into two groups which received sterilized PBS or bicyclol (100 mg/kg per day) orally for two consecutive weeks. Serum, urine and bile were collected for biochemical determinations. Liver tissues were collected for histological analysis and a whole genome oligonucleotide microarray assay. Reverse transcription-polymerase chain reaction and Western blotting were used to verify the expression of liver fibrosis-related genes.

RESULTS: Treatment with bicyclol significantly reduced liver fibrosis and bile duct proliferation after BDL. The levels of alanine aminotransferase (127.7 ± 72.3 vs 230.4 ± 69.6, P < 0.05) and aspartate aminotransferase (696.8 ± 232.6 vs 1032.6 ± 165.8, P < 0.05) were also decreased by treatment with bicyclol in comparison to PBS. The expression changes of 45 fibrogenic genes and several fibrogenesis-related pathways were reversed by bicyclol in the microarray assay. Bicyclol significantly reduced liver mRNA and/or protein expression levels of collagen 1a1, matrix metalloproteinase 2, tumor necrosis factor, tissue inhibitors of metalloproteinases 2, transforming growth factor-β1 and α-smooth muscle actin.

CONCLUSION: Bicyclol significantly attenuates BDL-induced liver fibrosis by reversing fibrogenic gene expression. These findings suggest that bicyclol might be an effective anti-fibrotic drug for the treatment of cholestatic liver disease.

Potent therapeutic target of inflammation, virus and tumor: focus on interleukin-27

Interleukin (IL)-27 is an important pleiotropic immunological regulator for having dual effects on the immune responses. Several distinct findings have been highlighted that in certain conditions, neutralizing IL-27 or its subunit IL-27p28 might be a useful strategy to limit inflammation. Recently more insights have revealed that IL-27 could also exert potent inhibitory functions in some other immune circumstances including virus infection and tumor immunity. In this review, we describe IL-27 receptor subunits and the mechanisms of individual IL-27, and summarize the advances of their preclinical application trials. In addition, the potential role of IL-27 as a clinical therapeutic target will also be discussed.

Evaluation of a Streptococcus thermophilus strain with innate anti-inflammatory properties as a vehicle for IL-10 cDNA delivery in an acute colitis model

The aim of this work was to develop a Streptococcus (S.) thermophilus strain with improved anti-inflammatory properties due to the incorporation of the therapeutic cDNA delivery plasmid pValac::il-10. To achieve this purpose, cells of S. thermophilus CRL807, previously selected as being an important anti-inflammatory strain, were electroporated with pValac::il-10 plasmid. In order to confirm the functionality of the developed strain, it was co-cultured with human epithelial cells Caco-2 and the production of IL-10 was evaluated by ELISA. Bacterial suspensions of S. thermophilus CRL807 containing pValac::il-10 plasmid or of the wild-type (WT) strain were administered in vivo using a murine model of intestinal inflammation. The animals treated with S. thermophilus CRL807 pValac::il-10 showed a lower body weight loss, microbial translocation to liver and damage scores in their intestines at macroscopical and microscopic levels. Furthermore, a significant increase was observed in the concentration of IL-10 in the intestinal contents of these mice compared to the rest of the experimental groups, accompanied by decreased levels of pro-inflammatory cytokines. The insertion of the therapeutic pValac::il-10 plasmid increased the intrinsic anti-inflammatory activity (synergetic effect) of S. thermophilus CRL807 which could be included in novel treatment protocols for inflammatory bowel diseases.

Anti-inflammatory and hepatoprotective effects of Ganoderma lucidum polysaccharides on carbon tetrachloride-induced hepatocyte damage in common carp (Cyprinus carpio L.)

The aim of this study was to investigate the anti-inflammatory and hepatoprotective effects of Ganoderma lucidum polysaccharides (GLPS) on carbon tetrachloride (CCl4)-induced hepatocyte damage in common carp (Cyprinus carpio L.). GLPS (0.1, 0.3, 0.6mg/ml) were added to the primary hepatocytes before (pre-treatment), after (post-treatment) and both before and after (pre- and post-treatment) the incubation of the hepatocytes with CCl4 at the concentration of 8mM in the culture medium. The supernatants and cells were collected respectively to detect the biochemical indicators. The levels of TNF-α, IL-1β, caspase-3 and caspase-8 were measured by ELISA, the mRNA expressions of CYP1A and CYP3A were determined by RT-PCR, and western blotting was used to assay the relative protein expressions of c-Rel and p65. Results showed that GLPS significantly improved cell viability and inhibited the elevations of the marker enzymes (GOT, GPT, LDH) and MDA induced by CCl4, and markedly increased the level of SOD. Treatments with GLPS resulted in a significant decrease in the expressions of CYP1A and CYP3A, and significantly down-regulated extrinsic apoptosis and immune inflammatory response. In brief, the present study showed that GLPS can protect hepatocyte injury induced by CCl4 through inhibiting lipid peroxidation, elevating antioxidant enzyme activity and suppressing apoptosis and immune inflammatory response.

An overview of effective therapies and recent advances in biomarkers for chronic liver diseases and associated liver cancer

Chronic liver diseases (CLDs) such as hepatitis, alcoholic liver disease, nonalcoholic fatty liver, and their downstream effect cancer affect more than a billion of people around the world both symptomatically and asymptomatically. The major limitation for early detection and suitable medical management of CLDs and liver cancer is either the absent of symptoms or their similar manifestations as other diseases. This detection impediment has led to a steady increase in the number of people suffering from CLDs with an ultimate outcome of liver failure and undergoing transplantation. A better understanding of CLD pathogenesis has helped us to develop novel therapies for patients who are at greatest risk for CLD progression to the most serious disease cancer. With the discovery of aberrant molecular pathways in CLDs, it is now possible to delineate a road map for selecting targeted therapies for CLDs. Technological advances in imaging as well as the availability of several stable, sensitive, early, noninvasive biomarkers for distinguishing different stages of CLDs and cancer have greatly facilitated both drug target identification and real-time monitoring of response to therapy. Biomarkers are the most useful in clinical practice for liver diseases like hepatocellular carcinoma (HCC), which is associated with secretion of various tumor-related proteins or nucleotides in peripheral circulation. The need for the identification of CLD biomarkers remains high. This article reviews the etiologies of CLDs, the results of recent clinical trials of treatments for CLDs, and development of noninvasive methodologies for detecting CLDs and monitoring their progression toward HCC.

Antiproliferative effects of curcumin analog L49H37 in pancreatic stellate cells: a comparative study

BACKGROUND

Pancreatic cancer is a devastating disease with poor prognosis. It is characterized by a pronounced stromal reaction, which resists chemotherapeutics and effective tumor treatment. Pancreatic stellate cells (PSCs) are mainly responsible for this stromal reaction. Moreover, the cancer and stromal interaction seems to promote tumor proliferation. In this study, L49H37, a newly synthesized curcumin analog, was used as intervention to target the stromal compartment of pancreatic cancer.

METHODS

In vitro cultures of human PSCs were exposed to curcumin and L49H37. Cell viability as well as growth promoting and survival signaling pathways were monitored by MTT, flow cytometry and western blotting.

RESULTS

Curcumin and L49H37 effectively inhibited proliferation and induced apoptosis in PSCs. L49H37 was found to be more potent at a lower concentration than curcumin in the induction of apoptosis, as evidenced by cleaved poly (ADP-ribose) polymerase (PARP). The cells were retained in the G0/G1 phase of the cell cycle through the downregulation of p21^WAF1/Cip1. L49H37 significantly decreased the phosphorylation of extracellular signal regulated kinase ½ (ERK½).

CONCLUSION

The results indicate that curcumin analog L49H37 exhibits more potent inhibitory effects than curcumin itself at a lower concentration, which suggests that it may have a potential for further evaluation of its use against pancreatic adenocarcinoma, either as a single agent but, more probable, as part of a combination regimen.

Cell-surface Vimentin: A mislocalized protein for isolating csVimentin(+) CD133(-) novel stem-like hepatocellular carcinoma cells expressing EMT markers

Recent advances in cancer stem cell biology have shown that cancer stem-like cells with epithelial-mesenchymal transition (EMT) phenotypes are more aggressive and cause relapse; however, absence of a specific marker to isolate these EMT stem-like cells hampers research in this direction. Cell surface markers have been identified for isolating cancer stem-like cells, but none has been identified for isolating cancer stem-like cells with EMT phenotype. Recently, we discovered that Vimentin, an intracellular EMT tumor cell marker, is present on the surface of colon metastatic tumor nodules in the liver. In our study, we examined the potential of targeting cell surface Vimentin (CSV) to isolate stem-like cancer cells with EMT phenotype, by using a specific CSV-binding antibody, 84-1. Using this antibody, we purified the CSV-positive, CD133-negative (csVim(+) CD133(-) ) cell population from primary liver tumor cell suspensions and characterized for stem cell properties. The results of sphere assays and staining for the stem cell markers Sox2 and Oct4A demonstrated that csVim(+) CD133(-) cells have stem-like properties similar to csVim(-) CD133(+) population. Our investigation further revealed that the csVim(+) CD133(-) cells had EMT phenotypes, as evidenced by the presence of Twist and Slug in the nucleus, the absence of EpCAM on the cell surface and basal level of expression of epithelial marker E-cadherin. The csVimentin-negative CD133-positive stem cells do not have any EMT phenotypes. csVim(+) CD133(-) cells exhibited more aggressively metastatic in livers than csVim(-) CD133(+) cells. Our findings indicate that csVim(+) CD133(-) cells are promising targets for treatment and prevention of metastatic hepatocellular carcinoma.