Betulinic acid inhibits the expression of hypoxia-inducible factor 1α and vascular endothelial growth factor in human endometrial adenocarcinoma cells

Although betulinic acid (BA) is known to induce apoptosis and antiangiogenic response in tumor cells, the underlying mechanism of its action is unknown. Deregulation of tissue collagen metabolism is one of the consequences of neoplastic transformation. The final step of collagen degradation is mediated by prolidase [E.C.3.4.13.9] which may play a role in angiogenesis. The formation of new blood vessels is regulated by the hypoxia-inducible factor 1 (HIF-1). The expression of HIF-1 correlates with hypoxia-induced angiogenesis as a result of the induction of vascular endothelial cell growth factor (VEGF). Since BA evokes anticancer activity, its effect on collagen biosynthesis, HIF-1α and VEGF expressions, as well as prolidase activity and expression was studied in cultured endometrial adenocarcinoma (EA) cells. It was found that BA inhibits collagen biosynthesis in EA cells (5[³H] proline incorporation assay). It was accompanied by a parallel decrease in prolidase activity and expression and decrease in expressions of α₁ and α₂ integrins, HIF-1α, and VEGF (western immunoblot analysis) in cultured human EA cells. The data suggest that BA may have anti-angiogenic potential by inhibition of prolidase, HIF-1α and VEGF expressions, and inhibition of collagen biosynthesis.     

Adjuvant potential of vitamin E in the induction of experimental allergic encephalomyelitis: histological aspects

In this study we report the effect of Vit. E, as an immunostimulating factor, on the induction of Experimental Allergic Encephalomyelitis in Lewis rat. The animals were inoculated intracutaneously in the plantar areas with emulsion of isologous spinal cord suspensed in Incomplete Freund's Adjuvant (IFI) and Vit. E. Histologic examination revealed the basic lesion of a perivenous cuff of mononuclear cells and small areas of demyelinated axons. The clinical signes are graded in order to the time of induction. It is possible an action of "adjuvanticity" of Vit. E on the various cells involved in the immune response by cell transformation and moltiplication.     

Neural projection patterns from homeotic tissue of Drosophila studied in bithorax mutants and mosaics.

The central projection patterns of sensory cells from the wing and haltere of Drosophila, as revealed by filling their axons with cobalt, consist of dorsal components arising from small campaniform sensilla and ventral components arising from large campaniform sensilla and from bristles. All of the bristles of the wing are innervated, some singly and some multiply. All three classes of sensilla are strongly represented on the wing, but the haltere carries primarily small campaniform sensilla and has a correspondingly minute ventral projection. In bithorax mutants in which the haltere is transformed into wing, ventral components are added to the projection pattern, while the dorsal components appear as if haltere tissue were still present. Thus, the three classes of receptors not only produce different projection patterns when they develop in their native mesothoracic segment, but also behave differently in the homeotic situation. Consequently, different developmental programs are inferred for each class. When somatic recombination clones of bithorax tissue are generated in phenotypically wild-type flies, they also produce ventral projections. However, these projections of mutant fibers into wild-type ganglia differ in certain details from the projections of mutant fibers into mutant ganglia. Thus, homeotic changes are inferred to occur in the CNS of mutant flies, but these are not required for the execution of those developmental instructions carried in the genome of large campaniform and bristle sensory cells which specify that their axons should grow ventrad in the CNS.     

A novel mutation of the IRF6 gene in an Italian family with Van der Woude syndrome

Van der Woude syndrome (VWS) is the most common type of syndromic orofacial cleft, being characterised by variable association of lower lip pits, cleft lip and cleft palate. VWS is transmitted in an autosomal dominant manner, with high penetrance and variable expressivity, and a gene for this disease has been mapped in 1q32-q41. Very recently, mutations of the interferon regulatory factor 6 (IRF6) gene have been found in VWS patients, suggesting that this gene plays an important role in the orofacial development. We report a novel mutation of the IRF6 in an Italian family with six members affected by VWS with different expression. This mutation, the W217X, produces a stop codon within exon 6 of the IRF6 gene, with loss of the SMIR domain of the IRF6 protein.     

Fasting-induced inhibition of collagen biosynthesis in rat skin. A possible role for phosphoenolpyruvate in this process

Fasting is accompanied by a decrease in collagen biosynthesis. The mechanism of this phenomenon involves inhibition of prolidase activity, an enzyme that plays a key role in upregulation of collagen metabolism. The mechanism of fasting-induced inhibition of prolidase activity is not known. Phosphoenolpyruvate (PEP) is known as a strong inhibitor of prolidase activity. It exerts this effect by inhibition of the enzyme phosphorylation. Unphosphorylated prolidase is inactive. One may expect that fasting-associated increase in posphoenolpyruvate content in animal tissues may be a factor which inactivates prolidase and makes it inactive in collagen biosynthesis. We measured the levels of phosphoenolpyruvate, pyruvate, and pyruvate kinase in the skin of control and fasted rats and correlated these parameters with prolidase expression, prolidase activity and collagen biosynthesis in this tissue. Significant increase of PEP concentration (about 30%) was found in the skin of fasted rats. In the same time prolidase activity and collagen biosynthesis decreased by about 50% and 30%, respectively, compared to controls. It is known that phosphoenolpyruvate is converted to pyruvate by the action of pyruvate kinase. Since fasting significantly decreases the activity of this enzyme, one may suggest that the accumulation of PEP is caused by a reduced utilisation of this metabolite. As demonstrated by Western immunoblot analysis the decrease in prolidase activity was not accompanied by a decrease in the amount of the enzyme protein. Instead, a decrease in the enzyme phosphorylation was observed. The reduction in phosphorylation seems to be responsible for the decrease in prolidase activity. These data suggest that fasting-evoked accumulation of PEP reduces the activity of prolidase, providing a mechanism for inhibition of collagen biosynthesis in the skin.