Therapeutic applications of bone marrow-derived stem cells in liver transplantation for end-stage liver diseases

Today, liver transplantation (LT) is the only established treatment for end-stage liver diseases. The de- velopment of LT, including OLT, cadaveric LT, split LT, living donor LT (LDLT), brings hopes to patients with these diseases. However, increasing donor shortage, rejection and life-long immunosuppression with its side effects are the major limitations of this therapy strategy. Bone marrow-derived stem cells (BMDSCs) are capable of differentiating into hepatocyte-like cells and contribute to liver injury repair. The microenvironment of liver injury caused by rejection, ischemia/reperfusion, loss of liver mass, recurrence of HCV and "small-for-size syndrome" after LT can attract a variety of bone marrow-derived stem cell population to the peripheral circulation and then migration to the injury liver to promote the hepatic function restoration. Additionally, BMDSCs can also take part in the functional regeneration of living donor liver after LDLT. This participation in liver regeneration may be associated to the interac- tion between SDF-1and its receptor CXCR4, involving HGF, IL-8, MMP9, and VEGF/VEGFR-2. BMDSC with its bio-characteristics could maintain the allograft tolerance from different angles and in different ways. In conclusion, BMDSCs transplantation, as a new assistant therapeutic method for LT, will ex- pand the space of LT, and provide more survival opportunities for the patients suffering liver diseases in the future.     

Receiving mixed signals: uncoupling oligodendrocyte differentiation and myelination

The development and maturation of an oligodendroglial cell is comprised of three intimately related processes that include proliferation, differentiation, and myelination. Here we review how proliferation and differentiation are controlled by distinct molecular mechanisms and discuss whether differentiation is merely a default of inhibited proliferation. We then address whether differentiation and myelination can be uncoupled in a similar manner. This task is particularly challenging because an oligodendrocyte cannot myelinate without first differentiating, and these processes are therefore not mutually exclusive. Is it solely the presence of the axon that distinguishes a differentiated oligodendrocyte from a myelinating one? Uncoupling these two processes requires identifying specific signals that regulate myelination without affecting the differentiation process. We will review current understanding of the relationship between differentiation and myelination and discuss whether these two processes can truly be uncoupled.     

Alternative exon usage selectively determines both tissue distribution and subcellular localization of the acyl-CoA thioesterase 7 gene products

Acyl-CoA thioesterases (ACOTs) catalyze the hydrolysis of acyl-CoAs to free fatty acids and coenzyme A. Recent studies have demonstrated that one gene named Acot7, reported to be mainly expressed in brain and testis, is transcribed in several different isoforms by alternative usage of first exons. Strongly decreased levels of ACOT7 activity and protein in both mitochondria and cytosol was reported in patients diagnosed with fatty acid oxidation defects, linking ACOT7 function to regulation of fatty acid oxidation in other tissues. In this study, we have identified five possible first exons in mouse Acot7 (Acot7a–e) and show that all five first exons are transcribed in a tissue-specific manner. Taken together, these data show that the Acot7 gene is expressed as multiple isoforms in a tissue-specific manner, and that expression in tissues other than brain and testis is likely to play important roles in fatty acid metabolism. Received 5 February 2007: received after revision 3 April 2007; accepted 19 April 2007     

Fettsäuren aus dehydratisiertem Rizinusöl mit sog. Vitamin-F-Wirkung

Summary The fatty acids from dehydrated castor oil, mainly consisting of 9,11- and 9,12-linoleic acid, show in biological tests vitamin effects similar to those of the so-called essential fatty acids.     

Activation of a C. elegans Antennapedia homologue in migrating cells controls their direction of migration.

Anterior-posterior patterning in insects, vertebrates and nematodes involves members of conserved Antennapedia-class homeobox gene clusters (HOM-C) that are thought to give specific body regions their identities. The effects of these genes on region-specific body structures have been described extensively, particularly in Drosophila, but little is known about how HOM-C genes affect the behaviours of cells that migrate into their domains of function. In Caenorhabditis elegans, the Antennapedia-like HOM-C gene mab-5 not only specifies postembryonic fates of cells in a posterior body region, but also influences the migration of mesodermal and neural cells that move through this region. Here we show that as one neuroblast migrates into this posterior region, it switches on mab-5 gene expression; mab-5 then acts as a developmental switch to control the migratory behaviour of the neuroblast descendants. HOM-C genes can therefore not only direct region-specific patterns of cell division and differentiation, but can also act within migrating cells to programme region-specific migratory behaviour.