Endometrial epithelial cell modifications in response to embryonic signals in bonnet monkeys (Macaca radiata)

The present investigation reports embryo-induced modifications in the epithelial cells of the endometrium in a primate species. In vivo, epithelial cell response to the embryonic signals was assessed at the embryo attachment stage in the gestational uterus of bonnet monkeys (Macaca radiata) and in vitro response was investigated by treating human endometrial epithelial cell line (Ishikawa) with human embryo conditioned media (CM). Endometrial epithelial (EE) cells at the embryo attachment stage in bonnet monkeys revealed higher proliferation accompanied by significant up regulation (p < 0.05) in the expression of estrogen receptor (ER)α and down regulation (p < 0.05) in ERβ expression. Further gestational EE cells showed higher (p < 0.001) expression of mucin-1, except in the embryo attachment site. Also, observed were significantly higher expression (p < 0.05) and altered cytoplasmic distribution of α(v) and β(3) integrins, when compared to non-pregnant animals. In pregnant animals, the embryo attachment zone showed differential expression of immunoreactive integrins as compared to the non-attachment zone. This suggested the role of embryo secreted factors in modulation of the epithelial cell profile. In vitro studies partially supported this assumption. Significantly higher proliferation (p < 0.05), as well as increased expression of ERα, integrin β(3) and mucin-1 (p < 0.05) were observed in Ishikawa cells, on stimulation with CM. Taken together, these results indicated the proliferation and modulation in the expression of estrogen receptors and cell adhesion molecules in the EE cells; at the embryo attachment stage in bonnet monkeys. Further it is likely that embryo secreted factors contribute to some of these modifications in EE cells. This report is the first account of discrete cellular events, which occur in the uterine epithelium, at the embryo attachment stage in a primate species.     

Quantification of Frankia in soils using SYBR Green based qPCR

A SYBR Green based qPCR method was developed for the quantification of clusters 1 and 3 of the actinomycete Frankia in soils. Primer nifHr158 was designed to be used as reverse primer in combination with forward primer nifHf1 specifically amplifying a 191-bp fragment of the nifH gene of these Frankia. The primer combination was tested for specificity on selected pure cultures, and by comparative sequence analyses of randomly selected clones of a clone library generated with these primers from soil DNA extracts. After adjustments of DNA extraction conditions, and the determination of extraction efficiencies used for sample normalization, copy numbers of nifH genes representing Frankia of clusters 1 and 3 were quantified in different mineral soils, resulting in cell density estimates for these Frankia of up to 10(6) cells [g soil {dry weight}](-1) depending on the soil. Despite indications that the nifH gene is not a perfect target for the quantification of Frankia, the qPCR method described here provides a new tool for the quantification and thus a more complete examination of the ecology of Frankia in soils.     

PEGylation of Neuromedin U yields a promising candidate for the treatment of obesity and diabetes

Neuromedin U (NMU) is an endogenous peptide, whose role in the regulation of feeding and energy homeostasis is well documented. Two NMU receptors have been identified: NMUR1, expressed primarily in the periphery, and NMUR2, expressed predominantly in the brain. We recently demonstrated that acute peripheral administration of NMU exerts potent but acute anorectic activity and can improve glucose homeostasis, with both actions mediated by NMUR1. Here, we describe the development of a metabolically stable analog of NMU, based on derivatization of the native peptide with high molecular weight poly(ethylene) glycol (PEG) ('PEGylation'). PEG size, site of attachment, and conjugation chemistry were optimized, to yield an analog which displays robust and long-lasting anorectic activity and significant glucose-lowering activity in vivo. Studies in NMU receptor-deficient mice showed that PEG-NMU displays an expanded pharmacological profile, with the ability to engage NMUR2 in addition to NMUR1. In light of these data, PEGylated derivatives of NMU represent promising candidates for the treatment of obesity and diabetes.     

Folding path of P5abc RNA involves direct coupling of secondary and tertiary structures

Folding mechanisms in which secondary structures are stabilized through the formation of tertiary interactions are well documented in protein folding but challenge the folding hierarchy normally assumed for RNA. However, it is increasingly clear that RNA could fold by a similar mechanism. P5abc, a small independently folding tertiary domain of the Tetrahymena thermophila group I ribozyme, is known to fold by a secondary structure rearrangement involving helix P5c. However, the extent of this rearrangement and the precise stage of folding that triggers it are unknown. We use experiments and simulations to show that the P5c helix switches to the native secondary structure late in the folding pathway and is directly coupled to the formation of tertiary interactions in the A-rich bulge. P5c mutations show that the switch in P5c is not rate-determining and suggest that non-native interactions in P5c aid folding rather than impede it. Our study illustrates that despite significant differences in the building blocks of proteins and RNA, there may be common ways in which they self-assemble.     

Pyrrolidine and piperidine analogues of SC-57461A as potent,orally active inhibitors of leukotriene A(4) hydrolase

The synthesis and biological evaluation of a series of functionalized pyrrolidine- and piperidine-containing analogues of our lead LTA(4) hydrolase inhibitor, SC-57461A, is described. A number of compounds showed excellent potency in our in vitro screens and several demonstrated good oral activity in a mouse ex vivo assay. These efforts led to the identification of SC-56938 (14) as a potent, orally active inhibitor of LTA(4) hydrolase.     

Cell biology

A selection of interesting papers that were published in the two months before our press date in major journals most likely to report significant results in cell biology.     

Synthesis of per-sulfated flavonoids using 2,2,2-trichloro ethyl protecting group and their factor Xa inhibition potential

The synthesis of per-sulfated flavonoids, organic compounds with multiple sulfate groups, is challenging. We present here a two-step synthesis of fully sulfated flavonoids in high overall yields using the 2,2,2-trichloroethyl moiety as a protecting group. The two-step synthesis results in exclusive formation of the per-sulfated product in contrast to common sulfating agents that yield differentially sulfated mixture of compounds. Most per-sulfated flavonoids studied are activators of antithrombin for accelerated inhibition of factor Xa, a key enzyme of the blood coagulation cascade. As a group the per-sulfated flavonoids possess a range of factor Xa inhibition potential.