Define Mesenchymal Stem Cell from Its Fate: Biodisposition of Human Mesenchymal Stem Cells in Normal and Concanavalin A-Induced Liver Injury Mice.

The pharmaceutical industry and clinical trials have been revolutionized mesenchymal stem cell-based therapeutics. However, the pharmacokinetics of transplanted cells has been little characterized in their target tissues under healthy or disease condition. A quantitative polymerase chain reaction analytical method with matrix effect was developed to track the biodistribution of human mesenchymal stem cells in normal mice and those with Concanavalin A (Con A)-induced liver injury. Mesenchymal stem/stromal cell (MSC) disposition in blood and different organs were compared, and relevant pharmacokinetic parameters were calculated. Human MSCs (hMSCs) and mouse MSCs (mMSCs) displayed a very similar pharmacokinetic profile in all tested doses: about 95% of the detected hMSCs accumulated in the lung and 3% in the liver, and almost negligible cells were detected in other tissues. A significant double peak of hMSC concentration emerged in the lung within 1-2 hours after intravenous injection, as with mMSCs. Prazosin, a vasodilator, could eliminate the second peak in the lung and increase its Cmax and area under the concentration-time curve (AUC) by 10% in the first 2 hours. The injury caused by Con A was significantly reduced by hMSCs, and the Cmax and AUC0-8 (AUC from time 0 to 8 hours) of cells in the injured liver decreased by 54 and 50%, respectively. The Cmax and AUC would be improved with the alleviation of congestion through the administration of heparin. The study provides a novel insight into the pharmacokinetics of exogenous MSCs in normal and Con A-induced liver injury mice, which provides a framework for optimizing cell transplantation. SIGNIFICANCE STATEMENT: Mesenchymal stem/stromal cells (MSCs) are known for their potential as regenerative therapies in treating several diseases, but an insufficient understanding of the pharmacokinetics of MSCs restricts their future application. The current study was the first to elucidate the pharmacokinetics and possible factors, including dosage, species, and derived sources, in a systematic way. The study further revealed that Concanavalin A-induced liver injury significantly prevented cells from entering the injury site, which could be reversed by the diminished congestion achieved by heparin.

Depletion of serotonin relieves concanavalin A-induced liver fibrosis in mice by inhibiting inflammation, oxidative stress, and TGF-ß1/Smads signaling pathway.

Serotonin exerts important functions in several liver pathophysiological processes. In this study, we investigated the role of serotonin in concanavalin A (Con A)-induced liver fibrosis (LF) in mice and the underlying mechanisms. To establish the mouse model of LF, mice of wild-type (WT) and tryptophan hydroxylase 1 (Tph1) knockout (serotonin depletion) received Con A for 8 successive weeks. Degree of fibrosis was assessed by Sirius red staining, as well as the measurements of alpha smooth muscle actin (α- SMA), hydroxyproline (Hyp) and type I collagen in liver tissues. To elucidate the potential mechanisms, we assessed the effect of serotonin depletion on inflammatory, oxidative stress as well as TGF-ß1/Smads signaling pathway. We found that serotonin depletion significantly inhibited collagen deposition as evaluated by less collagenous fiber in Sirus Red staining and reduced contents of Hyp and type I collagen. In addition, the absence of serotonin significantly inhibited the release of several inflammatory cytokines, including interleukin-6 (IL-6), interferon-gamma (IFN-γ), tumor necrosis-alpha (TNF-α), and transforming growth factor ß1 (TGF-ß1). Oxidative stress was also largely mitigated in LF mice with serotonin deficiency as manifested by the decreases of oxidative stress markers (malonaldehyde (MDA) and myeloperoxidase (MPO)), as well as the increases of antioxidant stress indicators (glutathione (GSH), and GSH-px, catalase (CAT), superoxide dismutase (SOD)) in liver tissues. Moreover, the lack of serotonin may provide an antifibrotic role by inhibiting the intrahepatic expressions of TGF-ß1, phosphorylated-smad2 (p-smad2), and phosphorylated-smad3 (p-smad3). These results indicated that, serotonin depletion attenuates Con A-induced LF through the regulation of inflammatory response, oxidative stress injury, and TGF-ß1/Smads signaling pathway.

Differential response of T cells to an immunogen, a mitogen and a chemical carcinogen in a mouse model system.

In this study, we examined the relative immune response of T-lymphocytes and its intracellular cholesterol homeostasis, in a mouse model system, after treatment with immunogen, mitogen, and carcinogen. We studied the T-lymphocyte percentage, their LDL-receptor expression, along with the levels of serum interleukins (IL-2, IFNγ, IL-4, and IL-10) and intracellular cholesterol concentration (cytoplasmic and nuclear). The mitogen was found to be a better stimulator of T-cell marker expressions than the immunogen; though the immunogen was more effective on immunogenic response as was marked from interleukin levels. The chemical carcinogen benzo-α-pyrene at low concentration acted potentially like a mitogen but a reduced immune response was apparent at a carcinogenic dose. The findings in our study focus on the effect of carcinogenic dose of benzo-α-pyrene (BaP) on T-cell immunity. Benzo-α-pyrene causes immunosuppression through restriction of the T-cell population by targeting intracellular cholesterol.

Impaired liver regeneration is associated with reduced cyclin B1 in natural killer T cell-deficient mice.

BACKGROUND: It has been shown that the proportion of natural killer T cells is markedly elevated during liver regeneration and their activation under different conditions can modulate this process. As natural killer T cells and liver injury are central in liver regeneration, elucidating their role is important. METHODS: The aim of the current study is to explore the role of natural killer T cells in impaired liver regeneration. Concanvalin A was injected 4 days before partial hepatectomy to natural killer T cells- deficient mice or to anti CD1d1-treated mice. Ki-67 and proliferating cell nuclear antigen were used to measure hepatocytes proliferation. Expression of hepatic cyclin B1 and proliferating cell nuclear antigen were evaluated by Western Blot and liver injury was assessed by ALT and histology. RESULTS: Natural killer T cells- deficient or mice injected with anti CD1d antibodies exhibited reduced liver regeneration. These mice were considerably resistant to ConA-induced liver injury. In the absence of NKT cells hepatic proliferating cell nuclear antigen and cyclin B1 decreased in mice injected with Concanvalin A before partial hepatectomy. This was accompanied with reduced serum interleukin-6 levels. CONCLUSIONS: Natural killer T cells play an important role in liver regeneration, which is associated with cyclin B1 and interleukin-6.

The content of docosahexaenoic acid in the suckling and the weaning diet beneficially modulates the ability of immune cells to response to stimuli.

The objective of the study was to isolate the effect of feeding a diet supplemented with docosahexaenoic acid (DHA) during the suckling and/or the weaning period on immune system development and function in offspring. Dams were randomized to one of two nutritionally adequate diets: control diet (N=12, 0% DHA) or DHA diet (N=8, 0.9% DHA). Diets were fed to dams throughout lactation, and then at weaning (21d), two pups per dam were randomly assigned to continue on the same diet as the dam or consume the other experimental diet for an additional 21d. At 6 weeks, splenocyte phenotypes and ex vivo cytokine production after stimulation with concanavalin A (ConA), lipopolysaccharide (LPS) or ovalbumin were assessed. Pups who received the control diet during both periods had the lowest production of IL-2 after ConA (P<.05 for interaction). Pups fed DHA during suckling had higher IL-10 production after all mitogens, regardless of the weaning diet (P<.05). Feeding DHA at weaning, regardless of the suckling diet, resulted in a lower production of IL-1ß and TNF-α in LPS-stimulated splenocytes and a higher proportion of total CD27+ cells (all P<.03). Our findings suggest that providing no DHA during critical periods of immune development resulted in a less efficient Th1 response upon challenge (IL-2 production). Feeding DHA during suckling had a programming effect on the ability of splenocytes to produce the regulatory cytokine IL-10. Feeding a DHA diet during weaning led to a lower TNF-α and IL-1ß response to a bacterial antigen.

Irreversible APC(Cdh1) Inactivation Underlies the Point of No Return for Cell-Cycle Entry.

Proliferating cells must cross a point of no return before they replicate their DNA and divide. This commitment decision plays a fundamental role in cancer and degenerative diseases and has been proposed to be mediated by phosphorylation of retinoblastoma (Rb) protein. Here, we show that inactivation of the anaphase-promoting complex/cyclosome (APC(Cdh1)) has the necessary characteristics to be the point of no return for cell-cycle entry. Our study shows that APC(Cdh1) inactivation is a rapid, bistable switch initiated shortly before the start of DNA replication by cyclin E/Cdk2 and made irreversible by Emi1. Exposure to stress between Rb phosphorylation and APC(Cdh1) inactivation, but not after APC(Cdh1) inactivation, reverted cells to a mitogen-sensitive quiescent state, from which they can later re-enter the cell cycle. Thus, APC(Cdh1) inactivation is the commitment point when cells lose the ability to return to quiescence and decide to progress through the cell cycle.

Cytotoxicity and mitogenicity assays with real-time and label-free monitoring of human granulosa cells with an impedance-based signal processing technology intergrating micro-electronics and cell biology.

A recently developed technology (xCelligence) integrating micro-electronics and cell biology allows real-time, uninterrupted and quantitative analysis of cell proliferation, viability and cytotoxicity by measuring the electrical impedance of the cell population in the wells without using any labeling agent. In this study we investigated if this system is a suitable model to analyze the effects of mitogenic (FSH) and cytotoxic (chemotherapy) agents with different toxicity profiles on human granulosa cells in comparison to conventional methods of assessing cell viability, DNA damage, apoptosis and steroidogenesis. The system generated the real-time growth curves of the cells, and determined their doubling times, mean cell indices and generated dose-response curves after exposure to cytotoxic and mitogenic stimuli. It accurately predicted the gonadotoxicity of the drugs and distinguished less toxic agents (5-FU and paclitaxel) from more toxic ones (cisplatin and cyclophosphamide). This platform can be a useful tool for specific end-point assays in reproductive toxicology.

Testosterone-induced micronuclei and increased nuclear division rate in L929 cell line expressing the androgen receptor.

Data on the possible genotoxic effects of testosterone are limited: in particular, the potential clastogenic and/or aneugenic effects have not yet been properly investigated. An in vitro micronucleus (MN) assay was performed on L929 cells exposed to testosterone at doses of 10, 15, 20, 30, and 40 µg/mL. Significantly increased MN frequencies were detected at doses of 20, 30, and 40 µg/mL after 24 h and 48 h of incubation. The nuclear division index was higher after 48 h than 24 h of incubation. A benchmark dose (BMD) calculation was used to estimate the 1% extra risk level for MN and increased tetranucleated cells. The calculated 1% extra risk level for MN at 24 h was 12.01 µg/mL, with a 95% lower confidence limit (BMDL) at 8.98 µg/mL; the corresponding BMD and BMDL at 48 h were 17.35 µg/mL and 10.69 µg/mL, respectively. The BMD for tetranucleated cells at 24 h was 14.86 µg/mL, with a BMDL of 7.75 µg/mL; the corresponding values at 48 h were 0.50 µg/mL for BMD and 0.87µg/mL for BMD. These findings suggest that the intensity of the mitogenic effect of testosterone increases upon prolonged exposure. The results of our study show that testosterone acts both as a mitogenic and genotoxic agent in L929 cells.

Zhankuic acid A as a novel JAK2 inhibitor for the treatment of concanavalin A-induced hepatitis.

Fruiting bodies of Taiwanofungus camphoratus have been widely used as an antidote for food poisoning and considered to be a precious folk medicine for anti-inflammation and hepatoprotection. Zhankuic acid A (ZAA) is its major pharmacologically active compound. Janus kinase 2 (JAK2), whose activation is involved in cytokine signaling, plays critical roles in the development and biology of the hematopoietic system. JAK2 has been implicated as a therapeutic target in inflammatory diseases. The HotLig modeling approach was used to generate the binding model for ZAA with JAK2, showing that ZAA could bind to the ATP-binding pocket of JAK2 exclusively via the H-bond. The interaction between ZAA and JAK2 was verified by antibody competition assay. Binding of ZAA to JAK2 reduced antibody recognition of native JAK2. The expressions of phosphorylated JAK2 and STATs were analyzed by immuno-blotting. ZAA reduced the phosphorylation and downstream signaling of JAK2, and inhibited the interferon (IFN)-γ/signal transducer and activator of transcription (STAT) 1/interferon regulatory factor (IRF)-1 pathway. The protective effect of ZAA on liver injury was evaluated in mice by Con-A-induced acute hepatitis. Pre-treatment with ZAA also significantly ameliorated acute liver injury in mice. Therefore, ZAA can inhibit JAK2 phosphorylation and protect against liver injury during acute hepatitis in mice. In this study, we present data that ZAA exerts anti-inflammatory effects through the JAK2 signaling pathway. As such, ZAA may be a potential therapeutic agent for the treatment of inflammatory diseases.

The protective role of myeloid-derived suppressor cells in concanavalin A-induced hepatic injury.

The mechanism underlying T cell-mediated fulminant hepatitis is not fully understood. In this study, we investigated whether myeloid derived suppressor cells (MDSCs) could prevent the concanavalin A (ConA)-induced hepatitis through suppressing T cell proliferation. We observed an increase in the frequencies of MDSCs in mouse spleen and liver at early stage of ConA treatment, implicating that the MDSCs might be involved in the initial resistance of mice against ConA-mediated inflammation. Subpopulation analysis showed that the MDSCs in liver of ConA-induced mice were mainly granulocytic MDSCs. Adoptive transfer of the bone marrow-derived MDSCs into ConA-treated mice showed that the MDSCs migrated into the liver and spleen where they suppressed T cell proliferation through ROS pathway. In addition, the frequencies of MDSCs in mice were also significantly increased by the treatment with immune suppressor glucocorticoids. Transfer of MDSCs into the regulatory T cell (Treg)-depleted mice showed that the protective effect of MDSCs on ConA-induced hepatitis is Treg-independent. In conclusion, our results demonstrate that MDSCs possess a direct protective role in T cell-mediated hepatitis, and increasing the frequency of MDSCs by either adoptive transfer or glucocorticoid treatment represents a potential cell-based therapeutic strategy for the acute inflammatory disease.

Tonsil-derived mesenchymal stem cells alleviate concanavalin A-induced acute liver injury.

Acute liver failure, the fatal deterioration of liver function, is the most common indication for emergency liver transplantation, and drug-induced liver injury and viral hepatitis are frequent in young adults. Stem cell therapy has come into the limelight as a potential therapeutic approach for various diseases, including liver failure and cirrhosis. In this study, we investigated therapeutic effects of tonsil-derived mesenchymal stem cells (T-MSCs) in concanavalin A (ConA)- and acetaminophen-induced acute liver injury. ConA-induced hepatitis resembles viral and immune-mediated hepatic injury, and acetaminophen overdose is the most frequent cause of acute liver failure in the United States and Europe. Intravenous administration of T-MSCs significantly reduced ConA-induced hepatic toxicity, but not acetaminophen-induced liver injury, affirming the immunoregulatory capacity of T-MSCs. T-MSCs were successfully recruited to damaged liver and suppressed inflammatory cytokine secretion. T-MSCs expressed high levels of galectin-1 and -3, and galectin-1 knockdown which partially diminished interleukin-2 and tumor necrosis factor α secretion from cultured T-cells. Galectin-1 knockdown in T-MSCs also reversed the protective effect of T-MSCs on ConA-induced hepatitis. These results suggest that galectin-1 plays an important role in immunoregulation of T-MSCs, which contributes to their protective effect in immune-mediated hepatitis. Further, suppression of T-cell activation by frozen and thawed T-MSCs implies great potential of T-MSC banking for clinical utilization in immune-mediated disease.

Ethyl pyruvate pretreatment attenuates concanavalin a-induced autoimmune hepatitis in mice.

PHARMACOLOGICAL RELEVANCE: Ethyl pyruvate (EP), a potent reactive oxygen species scavenger, has been reported to contribute to the inflammatory process. However, the protective effect of ethyl pyruvate on Concanavalin A (Con A)-induced autoimmune hepatitis have not been explored. Thus, the aims of this study are to investigate both the effects of ethyl pyruvate and its mechanism of protection on Con A-induced autoimmune hepatitis in mice. MATERIALS AND METHODS: Acute autoimmune hepatitis was induced by Con A (20 mg/kg) in Balb/C mice; ethyl pyruvate (40 mg/kg and 80 mg/kg) was administrated 1h prior to the Con A injection. At 3h, 6h and 24h post Con A injection, histological grading, proinflammatory cytokine levels and nuclear factor kappa B (NF-κB) activity were determined. RESULTS: Following Con A challenge, cytokines TNF-α, IL-2, IL-1ß and IL-6 were expressed at 3h and 6h, and the level of HMGB1 significantly increased by 24h. Pretreatment with ethyl pyruvate ameliorated the pathological effects of Con A-induced autoimmune hepatitis and significantly decreased the levels of TNF-α, IL-2, IL-6 and IL-1ß at 3h and 6h and the level of HMGB1 at 6h and 24h post injection. Ethyl pyruvate blocked the degradation of IκB α and IκB ß and decreased the expression of NF-κB at 24h. CONCLUSION: Taken together, these results indicated that ethyl pyruvate protected against Con A-induced autoimmune hepatitis by decreasing both early (TNF-α, IL-2, IL-1ß and IL-6) and late (HMGB1) cytokine expression in mice. The reduction of HMGB1 may correlate with the amelioration of NF-κB activity.

Hepatic protection and anticancer activity of curcuma: a potential chemopreventive strategy against hepatocellular carcinoma.

Malignant transformation of hepatocellular carcinoma (HCC) occurs through repetitive liver injury in a context of inflammation and oxidative DNA damage. A spectrum of natural sesquiterpenoids from curcuma oil has displayed antioxidant, anti-inflammatory and anti-carcinogenic properties. The aim of the study was to investigate the hepatoprotective and anti-HCC effects of curcuma oil in vivo and in vitro. Mice were pretreated with curcuma oil (100 mg/kg) for 3 days, then treated with Concanavalin A (30 mg/kg). The hepatic tissue was evaluated for histology, CD4+ cell, interferon-γ, apoptosis, lipid peroxidation, 8-hydroxy-deoxyguanosine and MnSOD. C57L/J mice were treated with curcuma oil and 107 Hepa1-6 cells directly inoculated into liver lobes. The effects of curcuma oil on cell growth and cell death were evaluated. In addition, MnSOD, HSP60, catalase, NF-κB and caspase-3 were also investigated in the Hepa1-6 cells treated with curcuma oil. Pretreatment with curcuma oil significantly attenuates inflammation and oxidative damage by Concanavalin A. Treatment with curcuma oil can decrease the incidence of HCC. Curcuma oil inhibits cell growth and induces cell death in Hepa1-6 cells. Curcuma protected mice with hepatic injury from inflammatory and oxidative stress. Curcuma oil can inhibit hepatoma cell growth in vivo and in vitro.

Opposing effects of prednisolone treatment on T/NKT cell- and hepatotoxin-mediated hepatitis in mice.

UNLABELLED: Prednisolone is a corticosteroid that has been used to treat inflammatory liver diseases such as autoimmune hepatitis and alcoholic hepatitis. However, the results have been controversial, and how prednisolone affects liver disease progression remains unknown. In the current study we examined the effect of prednisolone treatment on several models of liver injury, including T/NKT cell hepatitis induced by concanavalin A (ConA) and α-galactosylceramide (α-GalCer), and hepatotoxin-mediated hepatitis induced by carbon tetrachloride (CCl4 ) and/or ethanol. Prednisolone administration attenuated ConA- and α-GalCer-induced hepatitis and systemic inflammatory responses. Treating mice with prednisolone also suppressed inflammatory responses in a model of hepatotoxin (CCl4 )-induced hepatitis, but surprisingly exacerbated liver injury and delayed liver repair. In addition, administration of prednisolone also enhanced acetaminophen-, ethanol-, or ethanol plus CCl4 -induced liver injury. Immunohistochemical and flow cytometric analyses demonstrated that prednisolone treatment inhibited hepatic macrophage and neutrophil infiltration in CCl4 -induced hepatitis and suppressed their phagocytic activities in vivo and in vitro. Macrophage and/or neutrophil depletion aggravated CCl4 -induced liver injury and impeded liver regeneration. Finally, conditional disruption of glucocorticoid receptor in macrophages and neutrophils abolished prednisolone-mediated exacerbation of hepatotoxin-induced liver injury. CONCLUSION: Prednisolone treatment prevents T/NKT cell hepatitis but exacerbates hepatotoxin-induced liver injury by inhibiting macrophage- and neutrophil-mediated phagocytic and hepatic regenerative functions. These findings may not only increase our understanding of the steroid treatment mechanism but also help us to better manage steroid therapy in liver diseases.

Phosphoinositide 3-kinase δ/γ inhibition does not prevent concanavalin A-induced hepatitis.

An increasing number of studies have suggested that phosphoinositide 3-kinase-γ (PI3Kγ) and PI3Kδ are involved in the pathogenesis of autoimmune and inflammatory diseases, such as asthma and atherosclerosis. However, the underlying mechanism of acute hepatitis remains unknown. The present study aimed to determine the effect of PI3Kδ/γ inhibition on hepatic injury in a murine model of hepatitis induced by concanavalin A (ConA). It was demonstrated that the pharmacological inhibition of PI3Kδ/γ by TG100-115 did not prevent liver damage following ConA challenge. Furthermore, the PI3Kδ/γ inhibition resulted in elevated transaminase activity in the serum, aggravated hepatic lesions characterized by hepatic necrosis, increased inflammatory cell infiltration and apoptosis of hepatocytes. Survival tests demonstrated that TG100-115 significantly increased the death rate of mice following ConA challenge. In addition, TG100-115 increased the serum levels of the proinflammatory cytokine IL-2 following ConA injection. These results may oppose the development of PI3Kδ/γ inhibitors as therapeutic agents, particularly for the treatment of human hepatitis.

In vivo stimulatory effect of multi-component herbal remedy PADMA 28 on mitogen-induced proliferation of mice splenic lymphocytes and their chemokinetic activity.

UNLABELLED: PADMA 28, a natural herbal multi-compound remedy originates from traditional Tibetan medicine and possesses a variety of beneficial effects on experimental and clinical models of inflammation and atherosclerosis, as well as angioprotecive, antioxidative and wound-healing properties. The aim of the present study was to evaluate the in vivo influence of this remedy on the in vitro mitogen-induced proliferation of murine splenic lymphocytes and their chemokinetic activity in cell culture.The study was performed on 6-8 weeks old inbred Balb/c mice. PADMA28 was administered to mice per os in daily doses 5.8 mg (calculated from the highest dose recommended for human) or 0.085 mg (dose from the range of active doses of other herbal extracts containing polyphenolic substances used previously by us in experiments with mice), for 7 days. Control groups received water. RESULTS: No substantial differences were observed between groups of mice fed with low and high PADMA doses. In both of them, response of splenic lymphocztes to mitogen PHA (p < 0.001) and their in vitro chemokinetic activity (p < 0.001 for low dose and p < 0.01 for high dose) were highly significantly increased as compared to the controls. CONCLUSION: The results of our investigations suggest that PADMA 28 can stimulate cell-mediated immunity in mice and might be used for this purpose in the wide spectrum of doses.

Inhibition of natural killer cells protects the liver against acute injury in the absence of glycine N-methyltransferase.

UNLABELLED: Glycine N-methyltransferase (GNMT) catabolizes S-adenosylmethionine (SAMe), the main methyl donor of the body. Patients with cirrhosis show attenuated GNMT expression, which is absent in hepatocellular carcinoma (HCC) samples. GNMT(-/-) mice develop spontaneous steatosis that progresses to steatohepatitis, cirrhosis, and HCC. The liver is highly enriched with innate immune cells and plays a key role in the body's host defense and in the regulation of inflammation. Chronic inflammation is the major hallmark of nonalcoholic steatohepatitis (NASH) progression. The aim of our study was to uncover the molecular mechanisms leading to liver chronic inflammation in the absence of GNMT, focusing on the implication of natural killer (NK) / natural killer T (NKT) cells. We found increased expression of T helper (Th)1- over Th2-related cytokines, tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL)-R2/DR5, and several ligands of NK cells in GNMT(-/-) livers. Interestingly, NK cells from GNMT(-/-) mice were spontaneously activated, expressed more TRAIL, and had strong cytotoxic activity, suggesting their contribution to the proinflammatory environment in the liver. Accordingly, NK cells mediated hypersensitivity to concanavalin A (ConA)-mediated hepatitis in GNMT(-/-) mice. Moreover, GNMT(-/-) mice were hypersensitive to endotoxin-mediated liver injury. NK cell depletion and adoptive transfer of TRAIL(-/-) liver-NK cells protected the liver against lipopolysaccharide (LPS) liver damage. CONCLUSION: Our data allow us to conclude that TRAIL-producing NK cells actively contribute to promote a proinflammatory environment at early stages of fatty liver disease, suggesting that this cell compartment may contribute to the progression of NASH.

Curcumin attenuates Concanavalin A-induced liver injury in mice by inhibition of Toll-like receptor (TLR) 2, TLR4 and TLR9 expression.

Curcumin has antiviral, antioxidant, and anti-inflammatory properties. However, the hepatoprotective effects and molecular mechanisms of curcumin on acute liver injury have not been carefully examined. The aims of this study were to examine the anti-inflammatory effect of curcumin on Concanavalin A (Con A) induced hepatitis, and to elucidate its underlying molecular mechanisms in mice. Mice received curcumin (200 mg/kg body weight) by gavage before Con A intravenous administration. We found that curcumin pretreatment was able to significantly reduce the elevated plasma aminotransferase levels and liver necrosis in Con A-induced hepatitis. Also, curcumin pretreatment reduced intrahepatic expression of genes encoding pro-inflammatory molecules such as tumor necrosis factor α (TNF-α) and interferon γ (IFN-γ) as compared with the vehicle controls, but augmented anti-inflammatory cytokine interleukin 10 (IL-10) by enzyme linked immunosorbent assay (ELISA). Furthermore, the expression levels of Toll-like receptor (TLR) 2, TLR4 and TLR9 mRNA or protein in liver tissues were significantly lowered by curcumin treatment. Curcumin pretreatment did not affect hepatic Kupffer cell numbers after Con A injection. These results suggest that curcumin pretreatment protects against T cell-mediated hepatitis in mice. The beneficial effect of curcumin may be partly mediated by inhibiting the expression levels of TLR2, TLR4 and TLR9 in the liver.

A novel herbal formulation "LiverCare" differentially regulates primary rat hepatocyte and hepatocarcinoma cell proliferation in vitro.

Hepatocyte growth factor (HGF) plays an important role in hepatocyte proliferation. HGF expression is regulated by various signaling molecules and nuclear receptors. In the present study, LiverCare(®) (LC), a novel polyherbal formulation (The Himalaya Drug Company, Bangalore, India), was evaluated for its efficacy, using co-cultures of primary rat hepatocytes-non-parenchymal cells (NPCs) and human hepatocellular carcinoma cells (HepG2). The rate of primary hepatocyte co-culture proliferation was significantly and dose-dependently increased by LC as determined by [(3)H]thymidine incorporation into newly synthesized DNA and cell proliferation assay. LC also increased HGF expression in primary hepatocyte co-culture. Albumin and urea content remained constant during proliferation of hepatocyte co-cultures in the presence of LC with decreased activity of alanine aminotransferase. It is interesting that LC inhibited incorporation of [(3)H]thymidine into DNA in HepG2 cells. LC enhanced peroxisome proliferator-activated receptor-α expression during hepatocyte proliferation, whereas tumor necrosis factor-α expression remained unaffected. In conclusion, our study clearly showed that LC differentially regulates primary rat hepatocytes and human hepatocarcinoma cell proliferation. LC may be a promising candidate for treating degenerative liver diseases by enhancing liver regeneration.

Treatment of murine fulminant hepatitis with genetically engineered endothelial progenitor cells.

BACKGROUND & AIMS: Cell therapy has been used to attenuate liver injury. Here we evaluated whether genetic engineering of either bone marrow-derived mononuclear cells (MNC) or endothelial progenitor cells (EPC) many enhance their hepatoprotective properties. METHODS: Mice with ConA-induced hepatitis or with lethal fulminant hepatitis resulting from administration of an adenovirus encoding CD40L (AdCD40L) received an intra-splenic injection of saline or 2 × 10(6) unmodified MNC or EPC or the same cells transduced ex vivo with an adenovirus expressing luciferase (MNCLUC and EPCLUC) or encoding the hepatoprotective cytokine cardiotrophin-1 (CT-1) (MNCCT-1 and EPCCT-1). We analyzed the extent of liver damage, the intensity of inflammatory reaction, and animal survival. RESULTS: Luciferase immunohistochemistry showed that after injection into the spleen, the engineered cells migrated efficiently to the damaged liver. In mice with ConA hepatitis EPCCT-1, but not other forms of cell therapy, significantly decreased serum transaminases and induced more intense histological improvement than other treatments. This superior therapeutic effect was associated with upregulation of cytoprotective molecules including IGF-I and EGF, lower expression of proinflammatory cytokines, IL-1b and TNFα, and decreased granzyme B levels. In AdCD40L-induced lethal fulminant hepatitis, EPCCT-1 also exceeded other cell therapies in attenuating the expression of proinflammatory mediators and hepatic injury enabling 35.7% survival while mortality was 100% in the other treatment groups. CONCLUSIONS: Genetic engineering of EPC to overexpress CT-1 enhances the hepatoprotective properties of EPC and constitutes a therapy that deserves consideration for acute liver failure.