Effects of albumin-bilirubin complexes with syngeneic or allogeneic albumin on DNA and protein synthesis in liver and spleen of partially hepatectomized rats

Liver growth factor as a tissue regenerating factor in neurodegenerative diseases

Liver growth factor (LGF) is a hepatic mitogen purified by our group in 1986. In the following years we demonstrated its activity both in "in vivo" and "in vitro" systems, stimulating hepatocytes mitogenesis as well as liver regeneration in several models of liver injury. Furthermore, we established its chemical composition (albumin-bilirubin complex) and its mitogenic actions in liver. From 2000 onwards we used LGF as a tissue regenerating factor in several models of extrahepatic diseases. The use of Liver growth factor as a neural tissue regenerator has been recently protected (Patent No US 2014/8,642,551 B2). LGF administration stimulates neurogenesis and neuron survival, promotes migration of newly generated neurons, and induces the outgrowth of striatal dopaminergic terminals in 6-hidroxydopamine-lesioned rats. Furthermore, LGF treatment raises striatal dopamine levels and protects dopaminergic neurons in hemiparkinsonian animals. LGF also stimulates survival of grafted foetal neural stem cells in the damaged striatum, reduces rotational behaviour and improves motor coordination. Interestingly, LGF also exerts a neuroprotective role both in an experimental model of cerebellar ataxia and in a model of Friedrich´s ataxia. Microglia seem to be the cellular target of LGF in the CNS. Moreover, the activity of the factor could be mediated by the stimulation of MAPK´s signalling pathway and by regulating critical proteins for cell survival, such as Bcl-2 and phospho-CREB. Since the factor shows neuroprotective and neurorestorative effects we propose LGF as a patented novel therapeutic tool that may be useful for the treatment of Parkinson´s disease and cerebellar ataxias. Currently, our studies have been extended to other neurological disorders such as Alzheimer's disease (Patent No: US 2014/0113859 A1).

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.

Improvement in liver fibrosis, functionality and hemodynamics in CCI4-cirrhotic rats after injection of the Liver Growth Factor

BACKGROUND/AIMS

Most substances used in experimental models of cirrhosis are chosen either as protectors of lipid peroxidation, as antifibrogenic agents or as vitamins, among others. In this report, we analyze the improvement produced, in established cirrhosis (CCl4 plus phenobarbital) in rats, by intraperitoneal injection of Liver Growth Factor, a hepatic mitogen with activity both in vivo and in vitro.

METHODS

Following confirmation of CCl4-induced cirrhosis, Liver Growth Factor (4.5 microg per ratx2 injections/week for 3 weeks) was administered to one group of rats (Cirr+LGF). The remaining rats (Cirr) received saline. The groups were compared in terms of serum enzymes, tissue damage, total liver collagen, collagenase activity, microsomal enzyme activities, splanchnic and systemic hemodynamics and portosystemic shunting.

RESULTS

Treatment of rats presenting CCl4-induced cirrhosis with Liver Growth Factor decreased serum aminotransferase levels and increased levels of serum albumin and total protein. The Liver collagen content was lower in rats treated with Liver Growth Factor (2.96 vs. 4.32 mg/g liver, p<0.01). Microscopic studies revealed that the livers of rats receiving Liver Growth Factor showed decreases in fibrosis, necrosis and inflammatory infiltration, as well as a recovery of architectural integrity. Liver function was improved after treatment with Liver Growth Factor, as indicated by the rate constant for elimination of aminopyrine, which increased from 0.0063 to 0.0170 (p<0.05). This increase was accompanied by a higher total amount of cytochrome P-450 as well as of certain P-450 isoenzymes, especially those that are hormone-dependent, such as P-450 3A. The improved liver histology and function observed in Cirr+LGF rats was associated with decreases in portal pressure (14.4 vs. 9.4 mm Hg, p<0.01) and portosystemic shunting (55.8 vs. 11.5%, p<0.01), as well as increases in mean arterial pressure and systemic vascular resistance, and a reduction in ascites.

CONCLUSIONS

Administration of the hepatic mitogen, Liver Growth Factor, to CCl4-cirrhotic rats decreased liver collagen and reorganized the hepatic extracellular matrix, resulting in an improvement in liver function, reduced portal pressure and amelioration of ascites.