Enhanced expressions of endometrial tumour necrosis factor alpha and its receptors during early pregnancy in bonnet monkeys

Tumour necrosis factor alpha (TNF-alpha), a pro-inflammatory cytokine may play an active role in stimulating inflammatory reactions during pregnancy. However, the expression of endometrial TNF-alpha has not been investigated especially during early pregnancy, a phenomenon invariably accompanied by inflammatory reaction. In the present study, the endometrial expressions of TNF-alpha and its receptors (TNFR1 and TNFR2) during early pregnancy, when the embryo lies free in the zona hatched state in the uterine lumen, were analyzed by immunohistochemistry. The endometrial expressions of TNF-alpha, TNFR1 and TNFR2 were found to be significantly up-regulated (p < 0.05) in the glandular epithelium on day 6 post-ovulation in pregnant animals. The alteration in the expression of these molecules may contribute to the induction of local inflammatory reactions during implantation.     

Synthesis and biological evaluation of chalcones and their derived pyrazoles as potential cytotoxic agents

A series of substituted chalcones and their corresponding pyrazoles were synthesized and evaluated for in vitro cytotoxic activity against a panel of human cancer cell lines. Out of 93 compounds screened, 8 compounds, 1s, 3i,j,n, 4i,j,n and 4s, showed marked activity. Compounds 4j,n and 4s were found to be the most promising in this study. SAR is also discussed.     

A small library of trisubstituted pyrimidines as antimalarial and antitubercular agents

A small library of 20 trisubstituted pyrimidines were synthesized and evaluated for their in vitro antimalarial and antitubercular activities. Out of the total screened compounds, 16 compounds have shown in vitro antimalarial activity against Plasmodium falciparum in the range of 0.25-2microg/mL and 8 compounds have shown antitubercular activity against Mycobacterium tuberculosis H(37)Ra, at a concentration of 12.5microg/mL.     

Syntheses of 2,4,6-trisubstituted triazines as antimalarial agents

A series of 2,4,6-trisubstituted-1,3,5-triazines (2a-s) were synthesized and evaluated for their in vitro antimalarial activity against P. falciparum. Out of the 19 compounds synthesized eight compounds showed MIC in the range of 1-2 microg/mL. These compounds are in vitro several times more active than cycloguanil.     

Solid support synthesis of 6-aryl-2-substituted pyrimidin-4-yl phenols as anti-infective agents

A library of 30 trisubstituted pyrimidines were synthesized and evaluated for their in vitro antimalarial and antitubercular activity. Out of the 30 compounds synthesized, 23 compounds have shown in vitro antimalarial activity against Plasmodium falciparum in the range of 0.25-2 microg/mL and 16 compounds have shown antitubercular activity against Mycobacterium tuberculosis H37Ra, at a concentration of 25 microg/mL.     

Mechanism of action of interleukin-13 antagonist (IL-13E13K) in cells expressing various types of IL-4R

As interleukin (IL)-13 and IL-4 play a major role in various diseases including asthma, allergy, and malignancies, it is desirable to generate a molecule that blocks the effects of both cytokines. We previously generated a human IL-13 mutant (IL-13E13K), which is a powerful antagonist of IL-13, blocking the biological activities of IL-13. We now show that IL-13E13K also competitively inhibits signaling and biological activities of IL-4 through type II and partially through type III IL-4 receptor (R) system. IL-13E13K completely blocked the IL-4-induced phosphorylation of STAT6 and IL-4-dependent protein synthesis in cells expressing type II and partially type III IL-4R but not type I IL- 4R. Consistent with the inhibition of biological activities, IL-13E13K inhibited IL-4 binding to type II IL-4R-expressing cells but not to type I IL-4R-expressing cells. The inhibition efficiency of IL-4 binding by IL-13E13K was relatively lower compared to wtIL-13 even though IL-13E13K bound to IL-13Ralpha1 positive cells with a similar affinity to wtIL-13. These results indicate that Glu13 in IL-13 associates with IL-4Ralpha, and mutation to lysine decreases its binding ability to IL-4Ralpha chain. IL-13E13K binds to IL- 13Ralpha1, which is shared by both IL-13R and IL-4R systems. Consequently, IL-13E13K inhibits IL-4 binding to these cells and prevents heterodimer formation between IL-13Ralpha1 and IL-4Ralpha chains. This interference by IL-13E13K blocks the biological activities of not only IL-13 but also partially of IL-4. Thus, IL-13E13K may be a useful agent for the treatment of diseases such as asthma, allergic rhinitis, and cancer, which are dependent on signaling through both IL-4 and IL-13 receptors.     

The life span determinant p66Shc localizes to mitochondria where it associates with mitochondrial heat shock protein 70 and regulates trans-membrane potential

P66Shc regulates life span in mammals and is a critical component of the apoptotic response to oxidative stress. It functions as a downstream target of the tumor suppressor p53 and is indispensable for the ability of oxidative stress-activated p53 to induce apoptosis. The molecular mechanisms underlying the apoptogenic effect of p66Shc are unknown. Here we report the following three findings. (i) The apoptosome can be properly activated in vitro in the absence of p66Shc only if purified cytochrome c is supplied. (ii) Cytochrome c release after oxidative signals is impaired in the absence of p66Shc. (iii) p66Shc induces the collapse of the mitochondrial trans-membrane potential after oxidative stress. Furthermore, we showed that a fraction of cytosolic p66Shc localizes within mitochondria where it forms a complex with mitochondrial Hsp70. Treatment of cells with ultraviolet radiation induced the dissociation of this complex and the release of monomeric p66Shc. We propose that p66Shc regulates the mitochondrial pathway of apoptosis by inducing mitochondrial damage after dissociation from an inhibitory protein complex. Genetic and biochemical evidence suggests that mitochondria regulate life span through their effects on the energetic metabolism (mitochondrial theory of aging). Our data suggest that mitochondrial regulation of apoptosis might also contribute to life span determination.     

Chondrocyte protein with a poly-proline region (CHPPR) is a novel mitochondrial protein and promotes mitochondrial fission

We have recently identified a chondrocyte protein with a poly-proline region, referred to as CHPPR, and showed that this protein is expressed intracellularly in chick embryo chondrocytes. Conventional fluorescence and confocal localization of CHPPR shows that CHPPR is sorted to mitochondria. Furthermore, immunoelectron microscopy of CHPPR transfected cells demonstrates that this protein is mostly associated with the mitochondrial inner membranes. Careful analysis of CHPPR expressing cells reveals, instead of the regular mitochondrial tubular network, the presence of a number of small spheroid mitochondria. Here we show that the domain responsible for network-spheroid transition spans amino acid residues 182-309 including the poly-proline region. Functional analyses of mitochondrial activity rule out the possibility of mitochondrial damage in CHPPR transfected cells. Since cartilage expresses high levels of CHPPR mRNA when compared to other tissues and because CHPPR is associated with late stages of chondrocyte differentiation, we have investigated mitochondrial morphology in hypertrophic chondrocytes by MitoTracker Orange labeling. Confocal microscopy shows that these cells have spheroid mitochondria. Our data demonstrate that CHPPR is able to promote mitochondrial fission with a sequence specific mechanism suggesting that this event may be relevant to late stage of chondrocyte differentiation.     

Identification of the lipid droplet targeting domain of the Cidea protein

Cidea, the cell death-inducing DNA fragmentation factor-α-like effector (CIDE) domain-containing protein, is targeted to lipid droplets in mouse adipocytes, where it inhibits triglyceride hydrolysis and promotes lipid storage. In mice, Cidea may prevent lipolysis by binding and shielding lipid droplets from lipase association. Here we demonstrate that human Cidea localizes with lipid droplets in both adipocyte and nonadipocyte cell lines, and we ascribe specific functions to its protein domains. Expression of full-length Cidea in undifferentiated 3T3-L1 cells or COS-1 cells increases total cellular triglyceride and strikingly alters the morphology of lipid droplets by enhancing their size and reducing their number. Remarkably, both lipid droplet binding and increased triglyceride accumulation are also elicited by expression of only the carboxy-terminal 104 amino acids, indicating this small domain directs lipid droplet targeting and triglyceride shielding. However, unlike the full-length protein, expression of the carboxy-terminus causes clustering of small lipid droplets but not the formation of large droplets, identifying a novel function of the N terminus. Furthermore, human Cidea promotes lipid storage via lipolysis inhibition, as the expression of human Cidea in fully differentiated 3T3-L1 adipocytes causes a significant decrease in basal glycerol release. Taken together, these data indicate that the carboxy-terminal domain of Cidea directs lipid droplet targeting, lipid droplet clustering, and triglyceride accumulation, whereas the amino terminal domain is required for Cidea-mediated development of enlarged lipid droplets.