Liver growth factor antifibrotic activity in vivo is associated with a decrease in activation of hepatic stellate cells.

The antifibrotic activity of Liver Growth Factor (LGF), a liver mitogen, was previously demonstrated in several models of rat liver fibrosis and even in extrahepatic sites, such as carotid artery in hypertensive rats and rat CdCl2-induced lung fibrosis. In the present study, we have attempted to examine in depth its mechanism of antifibrotic action in bile duct-ligated (BDL) rats, with special emphasis on its activity in fibrogenic liver cells. BDL rats received either LGF 9 microg/week for 2 or 3 weeks (BDL+LGF, n=20/group) or saline (BDL+S, n=20/group), at times 0, week 2, or week 5 after operation. Groups were compared in terms of liver alpha-smooth muscle actin (SMA) content (western blotting and immunohistochemistry), hepatic apoptosis, liver desmin content (western blotting), and serum endothelin-1 (ELISA). LGF produced a marked decrease in liver alpha-SMA content compared with saline-injected rats, especially evident at longer times (5w and 8w; p<0.05). Moreover, LGF did not seem to influence HSC proliferation, as shown by measuring liver desmin content. The antifibrotic activity exerted by LGF seems to be closely related to a modulation of the activation state of fibrogenic liver cells (activated HSC and myofibroblasts) in BDL rats.

Intermolecular reaction of internal alkynes and imines: propargyl tosylates as key partners in a gold-catalyzed [4 + 1] unusual cyclization leading to cyclopent-2-enimines.

Propargyl tosylates react with N-tosylaldimines to afford cyclopent-2-enimines in a gold-catalyzed process that involves a deep reorganization of both substrates. The formal [4 + 1] cyclization is initiated by a 1,2-migration of the tosylate that eventually generates a substituted 1,3-diene. Subsequent interaction with the imine launches a series of reaction steps prior to a Nazarov-like cyclization to yield the final product.

1,2-Diaryl(3-pyridyl)ethanone oximes. Intermolecular hydrogen bonding networks revealed by X-ray diffraction.

The synthesis of a set of 1-aryl-2-aryl(3-pyridyl)ethanones 1-5 and the corresponding ketoximes 6-9 is reported. Structural studies of oximes 6, 7 and 9 were performed in solution using (1)H-NMR and in the solid state by X-ray crystallography, providing evidence of H-bonding networks. The crystal packing was controlled by homomeric intermolecular oxime...oxime H-bond interactions for 6 and cooperative oxime...N(pyridyl) and CH/pi interactions for 7 and 9.

The anti-fibrotic effect of liver growth factor is associated with decreased intrahepatic levels of matrix metalloproteinases 2 and 9 and transforming growth factor beta 1 in bile duct-ligated rats.

Liver growth factor (LGF), a mitogen for liver cells, behaves as an anti-fibrotic agent even in extrahepatic sites, but its mechanistic basis is unknown. We aimed to determine the intrahepatic expression pattern of key modulators of liver fibrosis in bile duct-ligated rats (BDL) after injection of LGF. BDL rats received either LGF (4.5 microg/ratXdose, two doses/week, at time 0 or 2 or 5w after operation, depending on the group (BDL+LGF groups, n=20) or saline (BDL+S groups, n=20). Groups were compared in terms of fibrosis (histomorphometry), liver function (aminopyrine breath test), matrix metalloproteinases MMP-2 and MMP-9, transforming growth factor beta 1 (TGF-beta1) and liver endoglin content (Western blotting), and serum tissue inhibitor of metalloproteinases 1 (TIMP-1) levels (ELISA). In BDL+LGF rats, the fibrotic index was significantly lower at 5w, p=0.006, and at 8w, p=0.04, than in BDL+S rats. Liver function values in BDL+LGF rats were higher than those obtained in BDL+S rats (80% at 5w and 79% at 8w, versus 38% and 29%, p<0.01, taking healthy controls as 100%). Notably, in BDL+LGF rats the intrahepatic expression levels of both MMPs were lower at 2w (MMP-2, p=0.03; MMP-9, p=0.05) and 5w (MMP-2, p=0.05, MMP-9, p=0.04). In addition, the hepatic TGF-beta1 level in BDL+LGF rats was lower at 2w (36%, p=0.008), 5w (50%) and 8wk (37%), whereas intrahepatic endoglin expression remained constant in all BDL rats studied. LGF ameliorates liver fibrosis and improves liver function in BDL rats. The LGF-induced anti-fibrotic effect is associated with a decreased hepatic level of MMP-2, MMP-9 and TGF-beta1 in fibrotic rats.

Effects of a novel disulfide bond and engineered electrostatic interactions on the thermostability of azurin.

Identification and evaluation of factors important for thermostability in proteins is a growing research field with many industrial applications. This study investigates the effects of introducing a novel disulfide bond and engineered electrostatic interactions with respect to the thermostability of holo azurin from Pseudomonas aeruginosa. Four mutants were selected on the basis of rational design and novel temperature-dependent atomic displacement factors from crystal data collected at elevated temperatures. The atomic displacement parameters describe the molecular movement at higher temperatures. The thermostability was evaluated by optical spectroscopy as well as by differential scanning calorimetry. Although azurin has a high inherent stability, the introduction of a novel disulfide bond connecting a flexible loop with small alpha-helix (D62C/K74C copper-containing mutant), increased the T(m) by 3.7 degrees C compared with the holo protein. Furthermore, three mutants were designed to introduce electrostatic interactions, K24R, D23E/K128R, and D23E/K128R/K24R. Mutant K24R stabilizes loops between two separate beta-strands and D23E/K128R was selected to stabilize the C-terminus of azurin. Furthermore, D23E/K128R/K24R was selected to reflect the combination of the electrostatic interactions in D23E/K128R and K24R. The mutants involving electrostatic interactions had a minor effect on the thermostability. The crystal structures of the copper-containing mutants D62C/K74C and K24R have been determined to 1.5 and 1.8 A resolution. In addition the crystal structure of the zinc-loaded mutant D62C/K74C has also been completed to 1.8 A resolution. These structures support the selected design and provide valuable information for evaluating effects of the modifications on the thermostability of holo azurin.

Effects of maternal adrenalectomy on the developing dopaminergic system.

The present study show that maternal adrenalectomy affect the developmental model of the dopaminergic system in the hypothalamus and hippocampus, with sexual dimorphism observed in both areas. No changes were observed in the developmental dopamine (DA) model of the cortex and striatum through dopamine levels were increased in striatum.

New Fischer carbene complexes of rhodium(i): preparation and 2-cyclopentenone ring synthesis by annelation to alkynes.

A new type of metal carbene complexes of group 9, specifically a cationic Fischer carbene of rhodium(I), has been synthesized from chromium carbene complexes via double transfer of carbene and CO ligands. These complexes reveal a different reactivity than other transition metal carbenes, including their chromium precursors, toward neutral and electron-poor alkynes, giving selectively polysubstituted cyclopentenones.

The mitogenic activity of the liver growth factor is mediated by tumor necrosis factor alpha in rat liver.

BACKGROUND/AIMS: Liver growth factor (LGF) is a hepatic mitogen, however, the hepatic stimulation pathway remains to be characterized. The aim of this study was to determine whether tumor necrosis factor alpha (TNF-alpha) stimulation constitutes a step in the mitogenic pathway of LGF. METHODS: Rats were injected with 4.5 microg LGF/rat, and LGF activity was measured both by liver DNA synthesis stimulation and "proliferating cell nuclear antigen (PCNA)-positive" hepatocytes in rats injected with LGF or +anti-TNF-alpha. TNF-alpha expression was evaluated by reverse-transcription polymerase chain reaction. TNF-alpha-producing cells were immunodetected. Human endothelial cells (HUVEC) were stimulated by LGF. TNF-alpha was detected in the supernatant, and the expression of intercellular adhesion molecule-1 (ICAM-1) and vascular endothelial adhesion molecule-1 (VCAM-1) by flow cytometry analysis. RESULTS: LGF-injected rats showed higher intrahepatic TNF-alpha expression. DNA synthesis and PCNA-positive hepatocytes induced by LGF were inhibited by anti-TNF-alpha, PCNA-positive hepatocytes being especially abundant around the central vein when LGF was injected alone, but TNF-alpha exhibited increased signal intensity in endothelial cells of the portal vein. LGF stimulated TNF-alpha secretion in HUVEC, but did not stimulate ICAM-1 or VCAM-1 up-regulation. CONCLUSIONS: The mitogenic cascade initiated by LGF in rat liver in vivo depends, at least in part, on TNF-alpha stimulation. Portal vein endothelial cells seem to be a source of TNF-alpha.

Combining image-seeking functions and a subtraction strategy: a vector-space procedure to improve many-body searches in molecular replacement.

Many-body searches in molecular replacement are usually carried out sequentially and each step benefits from the structural information obtained in previous rotational and translational stages. In this context, the incorporation of known structural information has proved to enhance the discrimination of a rotation function in Patterson space when many independent molecules have to be located in the asymmetric unit of the crystal cell. This improvement is achieved by subtraction of the contributions of already positioned molecules from the observed Patterson map, which makes the determination of the correct orientation of the remaining molecules easier. The quality of the resultant difference Patterson map is greatly influenced by the application of a bulk-solvent correction to the structure-factor amplitudes of the molecules that are being subtracted. The results obtained in the rotation search benefit both from the availability of high-resolution data and from the combination of the subtraction strategy and the refinement of a great number of the peaks of the rotation function.