Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.6.1.2 (alanine aminotransferase)
26,722 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The anti-CD30 immunotoxin (IT) Ber-H2/saporin is effective in patients with refractory Hodgkin's disease. However, responses are short and partial, one of the main reasons being the inability to repeat IT doses because of formation of human antibodies against the murine antibody and/or the toxin. To overcome this problem, we constructed two new anti-CD30 ITs by covalently linking the mouse monoclonal antibody Ber-H2 to the type 1 ribosome-inactivating proteins (RIPs) momordin (MOM) and pokeweed antiviral protein from seeds (PAP-S), which do not cross-react with each other or with saporin. Both ITs inhibited protein synthesis by Hodgkin's disease and anaplastic large-cell lymphoma (ALCL)-derived CD30+ target cell lines with a very high efficiency (IC50 ranging from < 5 x 10(-13) M to 2.75 x 10(-11) M, as RIP). In a SCID mouse model of xenografted CD30+ human ALCL, a 3d treatment with non-toxin doses of Ber-H2/MOM (50%LD50), started 24 h after transplantation, prevented tumour development in about 40% of the animals and significantly delayed tumour growth rate in the others. Main toxicity signs in mice and rabbits were dose-related increase of serum transaminases (AST and ALT) and creatine phosphokinase (CPK). LD50 (as RIP) in Swiss mice was 7 mg/kg for Ber-H2/MOM and 0.45 mg/kg for Ber-H2/PAP-S. Sequential administration of two anti-CD30 ITs (Ber-H2/MOM and Ber-H2/saporin) was well tolerated and did not result in formation of antibodies cross-reacting and with the two plant toxins. The results presented in this paper suggest that in the future, sequential administration of anti-CD30 humanized antibodies linked to antigenically distinct type 1 RIPs (saporin, MOM, PAP-S) should be feasible.
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PMID:Anti-CD30 (BER=H2) immunotoxins containing the type-1 ribosome-inactivating proteins momordin and PAP-S (pokeweed antiviral protein from seeds) display powerful antitumour activity against CD30+ tumour cells in vitro and in SCID mice. 861 80

Although neutrophils have been implicated in the hepatic injury elicited by gut ischemia/reperfusion (I/R), the contribution of other leukocyte populations to this injury process remains unclear. The objective of this study was to determine whether lymphocytes contribute to gut I/R-induced microvascular dysfunction and inflammatory responses in the liver. Intravital videomicroscopy was used to monitor leukocyte recruitment, the number of nonperfused sinusoids and pyridine nucleotide (NADH) autofluorescence in livers of wild-type, SCID, and interferon-gamma (IFN-gamma) knockout mice exposed to 15 min of gut ischemia and 1 h of reperfusion. In wild-type mice, gut I/R elicited significant increases in the number of stationary leukocytes, nonperfused sinusoids, NADH autofluorescence (indicating hypoxia), and elevated plasma alanine aminotransferase (ALT) and TNF-alpha levels. All of these responses were profoundly attenuated in SCID mice, while only some of the responses (in the midzonal region) were blunted in IFN-gamma knockout mice. Reconstitution (24 h before ischemia) of the circulating lymphocyte pool with T-cell enriched splenocytes, but not T cell deficient (from nude mice), CD4+ T-cell depleted splenocytes or splenocytes derived from IFN-gamma knockout mice, allowed the SCID mice to respond to gut I/R in a manner similar to wild-type mice. Some of the responses were restored following reconstitution with CD8+ T-cell depleted splenocytes. These findings implicate CD4+ T-lymphocytes and IFN-gamma in the hepatic microvascular dysfunction and inflammatory cell accumulation elicited by gut I/R.
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PMID:T-lymphocytes contribute to hepatic leukostasis and hypoxic stress induced by gut ischemia-reperfusion. 1065 78

Previously, we demonstrated that intrahepatic upregulation of the immunoactivating molecules CD40 and CD40 ligand (CD40L) are early mechanisms for liver cell damage in human and murine fulminant hepatic failure (FHF). In the present study, we investigated the functional effects of intrahepatic overexpression of CD40L by adenoviral-mediated gene transfer (AdCD40L) in mice. AdCD40L injection induced severe liver cell damage, which was associated with increased alanine aminotransferase (ALT) levels peaking at day 5 after vector administration (AdCD40L, 1,707 +/- 279 U/L; AdLacZ, 213 +/- 25 U/L) and with lethality in half of the mice. Except for mild splenomegaly, no organs other than the liver were involved in inflammatory reactions. CD40-CD40L interaction was mandatory for liver damage, because CD40(-/-) mice were completely protected. Furthermore, CD40L-induced FHF depended on competent lymphocytes, because inflammatory reactions were strongly decreased in SCID and Rag1(-/-) mice. In contrast, neither natural killer T (NKT) cells nor Kupffer cells relevantly influenced histology as shown in NKT cell-deficient CD1d(-/-) mice and by gadolinium depletion of Kupffer cells. Furthermore, immunosuppression by dexamethasone and cyclosporin A was not sufficient to block CD40L damage. In conclusion, we present a model of FHF with strong similarities to human FHF with respect to time course and histological changes. This model suggests involvement of the CD40-CD40L system in FHF and might have important implications for future pathophysiological studies of this condition.
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PMID:Induction of murine liver damage by overexpression of CD40 ligand provides an experimental model to study fulminant hepatic failure. 1687 41

Sepsis is a leading cause of death in pediatric intensive care units. There is growing evidence that lymphocytes play a pivotal role in mediating the microvascular dysfunction during sepsis. The objective of this study was to define the role of different subsets of lymphocytes in mediating the hepatic microvascular alterations elicited by cecal ligation and puncture (CLP), an experimental model of sepsis. Intravital video microscopy was used to quantify leukocyte and platelet adhesion in the hepatic microcirculation of wild type (WT) mice, immunodeficient SCID mice, SCID mice reconstituted with CD3+ cells, and mice deficient either in B-cells, CD4+- or CD8+-T-cells subjected to CLP. Blood cell counts, and serum concentrations of ALT and different cytokines (TNF-alpha, IL-10, MCP-1, IL-6, IFN-gamma and IL-12) were also monitored in these groups. CLP (at 6 h) caused a significantly increased adhesion of leukocytes and platelets in WT mice, compared to WT sham mice (P < 0.05). In SCID mice, the adhesion of blood cells in terminal hepatic venules was significantly decreased compared to WT-CLP mice, whereas the values in CD3+ cell-reconstituted SCID-mice, B-cell-deficient and CD4+- and CD8+-T-cell deficient mice did not differ from WT-CLP mice. ALT levels were significantly elevated only in the SCID group, when compared to WT-sham and WT-CLP mice. These findings indicate that lymphocytes mediate the microvascular dysfunction, but protect against the hepatocellular injury associated with murine sepsis.
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PMID:Hepatic microcirculation in murine sepsis: role of lymphocytes. 1795 48

A disseminated model of non-Hodgkin's lymphoma with prevalent liver metastasis was generated by intraperitoneal (i.p.) injection of EBV(+) B lymphoblastoid SKW6.4 in nude-SCID mice. The survival of SKW6.4 xenografts (median survival = 27 days) was significantly improved when hyaluronan scaffolds embedded with mesenchimal stem cells (MSC) were implanted in the abdominal area 4 days after SKW6.4 injection (median survival = 39.5 days). Mice implanted with MSC showed a significant improvement of hepatic functionality in lymphoma xenografts, as demonstrated by measurement of serum ALT/AST levels. Co-culture of MSC with lymphoma cells enhanced the release of hepatocyte growth factor (HGF) by MSC. These data suggest that hyaluronan-embedded MSC exert anti-lymphoma activity by ameliorating hepatic functionality.
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PMID:Mesenchymal stem cells display hepato-protective activity in lymphoma bearing xenografts. 2082 1

We investigated a small-molecule modulator of tumor necrosis factor alpha (TNF-alpha), UTL-5g (also referred to as GBL-5g), as a potential chemoprotective agent against cisplatin-induced side effects including nephrotoxicity, hepatotoxicity and hematotoxicity. Pretreatment of UTL-5g i.p. in BDF1 mice reduced the levels of blood urea nitrogen (BUN) and creatinine induced by cisplatin treatment. The levels of both aspartate transaminase (AST) and alanine transaminase (ALT) in these animals were also reduced by UTL-5g. Pretreatment of UTL-5g did not significantly affect the number of white blood cells (WBC) under current experimental conditions, yet it markedly increased blood platelet counts by more than threefold. Therapeutic assessment in SCID mice inoculated with human HCT-15 tumor cells showed that UTL-5g did not attenuate the anti-tumor effect of cisplatin but increased the therapeutic efficacy of cisplatin. The LD50 of UTL-5g was determined to be > 2,000 mg/kg by an acute toxicity study. In summary, our studies showed that 1) UTL-5g significantly reduces nephrotoxicity and hepatotoxicity induced by cisplatin in mice, presumably by lowering the levels of TNF-alpha, 2) UTL-5g markedly increased blood platelet counts in mice and 3) UTL-5g treatment increased the therapeutic efficacy of cisplatin against HCT-15 cells inoculated in SCID mice.
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PMID:The small-molecule TNF-alpha modulator, UTL-5g, reduces side effects induced by cisplatin and enhances the therapeutic effect of cisplatin in vivo. 2169 20

This work was initiated in an effort to evaluate the potential therapeutic contribution of the infusion of mesenchymal stem cells (MSC) for the correction of liver injuries. We subjected NOD-SCID mice to a 10.5-Gy abdominal irradiation and we tested the biological and histological markers of liver injury in the absence and after infusion of expanded human MSC. Irradiation alone induced a significant elevation of the ALT and AST. Apoptosis in the endothelial layer of vessels was observed. When MSC were infused in mice, a significant decrease of transaminases was measured, and a total disappearance of apoptotic cells. MSC were not found in liver. To explain the protection of liver without MSC engraftment, we hypothesize an indirect action of MSC on the liver via the intestinal tract. Pelvic or total body irradiation induces intestinal absorption defects leading to an alteration of the enterohepatic recirculation of bile acids. This alteration induces an increase in Deoxy Cholic Acid (DCA) which is hepatoxic. In this study, we confirm these results. DCA concentration increased approximately twofold after irradiation but stayed to the baseline level after MSC injection. We propose from our observations that, following irradiation, MSC infusion indirectly corrected liver dysfunction by preventing gut damage. This explanation would be consistent with the absence of MSC engraftment in liver. These results evidenced that MSC treatment of a target organ may have an effect on distant tissues. This observation comes in support to the interest for the use of MSC for cellular therapy in multiple pathologies proposed in the recent years.
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PMID:Intravenous human mesenchymal stem cells transplantation in NOD/SCID mice preserve liver integrity of irradiation damage. 2216 49

Troglitazone (Tro) is a thiazolidinedione antidiabetic drug that was withdrawn from the market due to its association with idiosyncratic severe liver injury. Tro has never induced liver injury in experimental animals in vivo. It was assumed that the species differences between human and experimental animals in the pharmaco- or toxicokinetics of Tro might be associated with these observations. In this study, we investigated whether a chimeric mouse with a humanized liver that we previously established, whose replacement index with human hepatocytes is up to 92% can reproduce Tro-induced liver injury. When the chimeric mice were orally administered Tro for 14 or 23 days (1000mg/kg/day), serum alanine aminotransferase (ALT) was significantly increased by 2.1- and 3.6-fold, respectively. Co-administration of l-buthionine sulfoximine (10mM in drinking water), an inhibitor of glutathione (GSH) synthesis, unexpectedly prevented the Tro-dependent increase of ALT, which suggests that the GSH scavenging pathway will not be involved in Tro-induced liver injury. To elucidate the mechanism of the onset of liver injury, hepatic GSH content, the level of oxidative stress markers and phase I and phase II drug metabolizing enzymes were determined. However, these factors were not associated with Tro-induced liver injury. An immune-mediated reaction may be associated with Tro-induced liver toxicity in vivo, because the chimeric mouse is derived from an immunodeficient SCID mouse. In conclusion, we successfully reproduced Tro-induced liver injury using chimeric mice with a humanized liver, which provides a new animal model for studying idiosyncratic drug-induced liver injury.
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PMID:Chimeric mice with a humanized liver as an animal model of troglitazone-induced liver injury. 2290 50

The immunodeficient mice transplanted with human hepatocytes are available for the study of the human hepatitis viruses. Recently, human hepatocytes were also successfully transplanted in herpes simplex virus type-1 thymidine kinase (TK)-NOG mice. In this study, we attempted to infect hepatitis virus in humanized TK-NOG mice and urokinase-type plasminogen activator-severe combined immunodeficiency (uPA-SCID) mice. TK-NOG mice were injected intraperitoneally with 6 mg/kg of ganciclovir (GCV), and transplanted with human hepatocytes. Humanized TK-NOG mice and uPA/SCID mice were injected with hepatitis B virus (HBV)- or hepatitis C virus (HCV)-positive human serum samples. Human hepatocyte repopulation index (RI) estimated from human serum albumin levels in TK-NOG mice correlated well with pre-transplantation serum ALT levels induced by ganciclovir treatment. All humanized TK-NOG and uPA-SCID mice injected with HBV infected serum developed viremia irrespective of lower replacement index. In contrast, establishment of HCV viremia was significantly more frequent in TK-NOG mice with low human hepatocyte RI (<70%) than uPA-SCID mice with similar RI. Frequency of mice spontaneously in early stage of viral infection experiment (8weeks after injection) was similar in both TK-NOG mice and uPA-SCID mice. Effects of drug treatment with entecavir or interferon were similar in both mouse models. TK-NOG mice thus useful for study of hepatitis virus virology and evaluation of anti-viral drugs.
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PMID:A novel TK-NOG based humanized mouse model for the study of HBV and HCV infections. 2414 55

Leukemia is a type of malignant tumors of hematopoietic system with the abnormal increased immature leukemia cells showing metastasis and invasion ability. Liver is one of the main targets of the leukemia cells spread to, where they may continue to proliferate and differentiate and cause liver function damage, even liver failure. Our previous studies showed that Angelica polysscharides (APS), the main effective components in Angelica sinensis of Chinese traditional medicine, was able to inhibit the proliferation and induced differentiation of the leukemia cells, however, its effect on the liver during the treatment remains elucidated. In the present study, the human leukemia NOD/SCID mouse model were established by implantation human leukemia K562 cells line, then the leukemia mouse were treated with APS, Ara-c or APS + Ara-c respectively by peritoneal injection for 14 days, to explore the effect and mechanism of the chemicals on the mouse liver. Compared to the human leukemia NOD/SCID mouse model group with the treatments of APS, Ara-c and APS + Ara-c, We found that severe liver damage and pathological changes of the liver were able to alleviate: First, the number of white blood cells in the peripheral blood was significantly lower and with less transplanted K562 leukemia cells; Second, liver function damage was alleviated as liver function tests showed that alanine aminotransferase (ALT), aspartate aminotransferase (AST) and total bilirubin (TBiL) were significantly reduced, while the albumin (Alb) was notably increased; Third, liver antioxidant ability was improved as the activities of the antioxidant enzymes glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) were significantly increased, and the contents of GSH and malonaldehyde (MDA) were decreased significantly in the liver; Fourth, the inflammation of the liver was relieved as the level of IL-1beta and IL-6, the inflammatory cytokines, were decreased significantly in the liver. Fifth, liver index was increased as the pathological observation showed that leukemia cells with diffused infiltration into the liver lobules were significantly reduced and with a remarkable increase of apoptotic positive cell rate by TUNEL test. Furthermore, the APS + Ara-c combined administration showed an even more significant positive effect. In conclusion, the APS, Ara-c therapy reduced the accumulation of leukemia cells within the liver, reduced the liver function damage and levels of inflammatory factors, improved antioxidant capacity of the liver tissue and thus alleviate the pathological changes of the liver. Moreover, the APS + Ara-c combination therapy may have an additive effect.
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PMID:[Effect of combined administration of Angelica polysaccharide and cytarabine on liver of human leukemia NOD/SCID mouse model]. 2475 80


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