Synthesis of 3-O-acyl/3-benzylidene/3-hydrazone/3-hydrazine/17-carboxyacryloyl ester derivatives of betulinic acid as anti-angiogenic agents

New 3-O-acyl, 3-benzylidene, 3-hydrazone, 3-hydrazine, 17-carboxyacryloyl ester derivatives of betulinic acid (2-6, 8-11, 13, 17, 18, 21, and 22) were synthesized and evaluated in vitro for anti-angiogenic activity on endothelial cell cytotoxicity, specificity, and tube-formation ability. All derivatives reported here showed IC(50)<4 microg/mL. Compounds 3, 9, 10, 17, 21, and 22 have shown better cytotoxicity (IC(50)<1.2 microg/mL) than betulinic acid (1) and improved endothelial cell specificity (ECS>10) in some cases. Compounds 10, 17, and 18 have shown 20%, 32%, and 48% reduction in TLS, respectively, and were found better than betulinic acid (1). We have shown that 20,29-dihydrobetulinic acid derivatives have better anti-angiogenic activity as compared to betulinic acid or its other derivatives.     

IN VITRO INCORPORATION OF 3H-THYMIDINE, 3H-URIDINE, 3H-LEUCINE AND 3H-MELPHALAN BY PLASMACYTOMA PLASMA CELLS

Bone marrow plasma cells from fifteen cases of multiple myeloma, immunologically typed, were incubated with different tritiated compounds. The labelling index with tritiated thymidine is generally low, while the mean grain count is fairly normal in the active cells. The labelling index of ³H-uridine and ³H-leucine was very high, while the mean grain count per cell lies within the normal range. The results obtained with ³H-phenylalanine-mustard (melphalan), which is a drug used in the treatment of the plasmacytoma, show also incorporation values roughly comparable to those of ³H-leucine. The present data seem to support the clinical use of melphalan as a compound that is actively incorporated into the plasma cells of plasmacytoma although inhibition of protein synthesis due to specific binding to protein was not demonstrated.     

Mammalian PIK3C3/VPS34

PIK3C3/Vps34 is the class III PtdIns3K that is evolutionarily conserved from yeast to mammals. Its central role in mammalian autophagy has been suggested through the use of pharmacological inhibitors and the study of its binding partners. However, the precise role of PIK3C3 in mammals is not clear. Using mouse strains that allow tissue-specific deletion of PIK3C3, we have described an essential role of PIK3C3 in regulating autophagy, and liver and heart function.     

NOV/CCN3 induces cartilage protection by inhibiting PI3K/AKT/mTOR pathway

Osteoarthritis (OA), an age‐related degenerative joint disease, is pathologically characterized by articular cartilage degeneration and synovial inflammation. Nephroblastoma overexpressed (NOV or CCN3), a matricellular protein, is a primary member of the CCN family (Cyr61, Ctgf, NOV) of proteins and is involved in various inflammatory disorders. Previous studies reported that CCN3 might play a therapeutic role in OA. However, the underlying mechanism remains unclear. In this study, we confirmed the expression of CCN3 was decreased in human and rat OA articular cartilage. Recombinant CCN3 ameliorated the IL‐1β‐induced matrix catabolism, as demonstrated by MMP1, MMP3, MMP13, ADAMTS5 and iNOS expression, in vitro. In addition, the degradation of cartilage matrix such as collagen 2 and aggrecan could be reversed by CCN3. Furthermore, we found CCN3 promoted autophagy as Atg5, Beclin1 and LC3‐II expression were increased. High‐mobility group box 1 was negatively correlated with CCN3 in IL‐1β‐induced osteoarthritis responses, and HMGB1 is involved in the protective effect of CCN3 in OA. Moreover, CCN3 overexpression decreased the expression of HMGB1 and reversed the IL‐1β induced MMPs production. Additionally, recombinant CCN3 or CCN3 overexpression attenuated the activation of PI3K/AKT/mTOR pathway induced by IL‐1β. Our study presents new mechanisms of CCN3 in osteoarthritis and indicates that CCN3 can serve as a novel potential therapeutic target for osteoarthritis.     

YidC/Oxa/Alb3蛋白家族

YidC/Oxa/Alb3蛋白家族是进化上保守的蛋白质转运酶,分别负责将一些与能量合成有关的膜蛋白转运到细菌内膜、线粒体内膜和叶绿体类囊体膜。它们具有保守的跨膜结构域,广泛存在于三界生物中。本文主要综述近年来对YidC/Oxa/Alb3家族成员的分布、结构、功能及进化的研究进展。     

Hysteretic behavior of proprotein convertase 1/3 (PC1/3)

The proprotein convertases (PCs) are calcium-dependent proteases responsible for processing precursor proteins into their active forms in eukariotes. The PC1/3 is a pivotal enzyme of this family that participates in the proteolytic maturation of prohormones and neuropeptides inside the regulated secretory pathway. In this paper we demonstrate that mouse proprotein convertase 1/3 (mPC1/3) has a lag phase of activation by substrates that can be interpreted as a hysteretic behavior of the enzyme for their hydrolysis. This is an unprecedented observation in peptidases, but is frequent in regulatory enzymes with physiological relevance. The lag phase of mPC1/3 is dependent on substrate, calcium concentration and pH. This hysteretic behavior may have implications in the physiological processes in which PC1/3 participates and could be considered an additional control step in the peptide hormone maturation processes as for instance in the transformation of proinsulin to insulin.     

The effective synthesis of uridylyl/3''-5''/5-methylcytidylyl/3''-5''/guanosine.

The triester method was adapted to the synthesis of uridylyl/3'-5'/5-methylcytidylyl/3'-5'/guanosine. As the protecting groups 4-methoxy-5,6-dihydro-2H-pyran for 2'-OH and 5'-OH groups of uridine and 2'-OH group of 5-methylcytidine, methoxymethylidene for I:3'-cis-diol system of guanosine, and benzoyl for the amino groups of 5-methylcytidine and guanosine were used. The obtained product was characterised by UV, electrophoresis, chromatography, an enzymatic digestion and alkaline hydrolysis.     

P2Y purinoceptors in normal NIH 3T3 and in NIH 3T3 overexpressing c-ras

The ability of purinergic agonists to induce Ca2+ responses has been tested in two lines of murine fibroblasts: normal NIH 3T3 fibroblasts and NIH 115.14, a clone expressing high levels [1] of the c-ras protooncogene. Both kinds of cells are responsive to ATP in the range 1 microM-1 mM; ADP and ATP gamma S are almost as potent as ATP, while AMP is unable to elicit a response. Ca2+ measurements performed in single cells by image analysis show great variability among cells but in each individual responding cell the Ca2+ rise occurs in an all-or-none fashion. The transient Ca2+ response does not depend on influx from the extracellular medium. Electrophysiological experiments reveal the activation of an outward current (at -50 mV) by ATP, probably due to Ca(2+)-activated K+ channels, confirming the absence of a substantial Ca2+ influx. Finally, stimulation by ATP produces a small but significant increase in the production of inositol phosphates. These results indicate that these cell lines possess purinergic receptors which are not integral membrane channels and which are coupled to InsP3 formation and may be therefore classified as P2Y.     

Biotechnology Journal 3/2008

Cover illustration: Spectral karyotype of chromosomes. The BTJ special issue on Methods and Advances in Biotech is not only covering DNA-based methods but also exciting highlights in the fields of imaging, bioluminescent screening methods, plant transformation assays, stem cell differentiation on chips and much more. Image copyright USA Federal Government. http://www.genome.gov , http://doi.wiley.com/biot.200800042