Acute 17β-Estradiol Pretreatment Protects Against Abdominal Aortic Occlusion Induced Spinal Cord Ischemic-Reperfusion Injury

Postoperative neurologic deficit due to spinal cord ischemia-reperfusion (I/R) injury is the most devastating complication following thoracoabdominal aortic aneurysm repairs. The protective potential for 17β-Estradiol has not been yet studied in such injury. In this study, ischemia induction for 18 min in male New Zealand White rabbits resulted in the highest percentage (80%) of biphasic paraplegic outcome assessed by Tarlov’s score. Acute Estradiol pretreatment (1 mg/kg, i.p., 30 min before I/R induction) altered this outcome and significantly prevented the worsening pattern of neurologic deficits over 48 h of observation. Histopathologic and oxidative stress evaluations of lumbar spinal cords taken in delayed permanent paraplegic phase (48 h after ischemia induction), further confirmed protective efficacy of Estradiol in such context. In western blot analysis, the expression of cleaved caspase-3 and heat shock protein 70 declined in Estradiol pretreated group compared to ischemic control group. TUNEL assay also showed the efficacy of Estradiol to abate motor neuron apoptosis. Interestingly, Estradiol respectively increased and decreased the expression of Cyclooxygenase (COX)-1 and COX-2, to a significant extent. Estradiol, exerting its protection through affecting one or a combination of involved biochemical factors can constitute a potential candidate to protect against thoracoabdominal aortic aneurysm repairs induced spinal cord I/R injury.     

Semantic, typicality and odor representation: a cross-cultural study

This study investigated odor-category organization in threecultures by evaluating (i) the relationship between linguisticand perceptual categorization and (ii) the existence of an internalstructure of odor categories. In the first experiment, threegroups of 30 participants from American, French and Vietnamesecultures performed a sorting task. The first group sorted 40odorants on the basis of odor similarity, the second group sorted40 odor names on the basis of name similarity and the last groupsorted 40 odor names on the basis of imagined odor similarity.Results showed that odor categorization was based on perceptualor conceptual similarity and was in part independent of wordand imagined categorizations. In the second experiment, anothergroup of 30 participants from each culture rated the typicalityof the odorants for 11 odor categories. Results showed thatsome odorants were rated as more typical than others. Moreover,the typicality gradient predicted the odor space obtained inthe odor sorting task in a consensual way among the three cultures.These results suggest that, as for other categories, odor categoriesare based on perceptual similarities rather than on semanticcues. Moreover odor-category structure might have a core representationwhich might be common to different cultures with boundarieswhich might be more culturally dependent.     

Enantioselective cyanoformylation of aldehydes catalyzed with solid base mediated chiral V(V) salen complexes

Polymeric and monomeric V(V) chiral salen complexes‐catalyzed enantioselective ethyl cyanoformylation of aldehydes using ethyl cyanoformate as a source of cyanide was accomplished in the presence of several basic cocatalysts viz., NaOH, KOH, basic Al₂O₃ and hydrotalcite. Excellent yield (>95%) of chiral ethyl cyanohydrincarbonate with high enantioselectivity up to 94% was achieved in 24–36 h when hydrotalcite was used as an additive. The polymeric catalyst 1 is more reactive than the monomeric catalyst 2 to produce chiral ethyl cyanohydrincarbonate in high optical purity. The chiral polymeric catalyst 1 and cocatalysts hydrotalcite and basic alumina used in this study were recoverable and recyclable several times with retention of its performance. Chirality, 2010. © 2009 Wiley‐Liss, Inc.     

Isoform specificity of ankyrin-B: a site in the divergent C-terminal domain is required for intramolecular association

Ankyrins contain significant amino acid identity and are co-expressed in many cell types yet maintain unique functions in vivo. Recent studies have identified the highly divergent C-terminal domain in ankyrin-B as the key domain for driving ankyrin-B-specific functions in cardiomyocytes. Here we identify an intramolecular interaction between the C-terminal domain and the membrane-binding domain of ankyrin-B using pure proteins in solution and the yeast two-hybrid assay. Through extensive deletion and alanine-scanning mutagenesis we have mapped key residues for interaction in both domains. Amino acids (1597)EED(1599) located in the ankyrin-B C-terminal domain and amino acids Arg(37)/Arg(40) located in ANK repeat 1 are necessary for inter-domain interactions in yeast two-hybrid assays. Furthermore, conversion of amino acids EED(1597) to AAA(1597) leads to a loss of function in the localization of inositol 1,4,5-trisphosphate receptors in ankyrin-B mutant cardiomyocytes. Physical properties of the ankyrin-B C-terminal domain determined by circular dichroism spectroscopy and hydrodynamic parameters reveal it is unstructured and highly extended in solution. Similar structural studies performed on full-length 220-kDa ankyrin-B harboring alanine substitutions, (1597)AAA(1599), reveal a more extended conformation compared with wild-type ankyrin-B. Taken together these results suggest a model of an extended and unstructured C-terminal domain folding back to bind and potentially regulate the membrane-binding domain of ankyrin-B.     

PI3K Inhibition Sensitize the Cisplatin-resistant Human Ovarian Cancer Cell OVCAR3 by Induction of Oxidative Stress

Background:This study evaluates the effect of simultaneous AKT inhibition and cisplatin therapy in changes of Reactive Oxygen Species (ROS) production, apoptosis induction, and cell survival in cisplatin-resistant OVCAR3 cell.Methods:OVCAR3 cancer cells were treated with cisplatin, Ly 294002 (LY), and cisplatin+Ly to investigate the cytotoxicity effect of the mentioned groups via MTT assay. Then, DCFH-DA (2′, 7′-dichlorodihydro fluorescein diacetate) assay kit is used to assess the potential of treated groups in intracellular ROS generation. Protein expression levels of caspase-3, cleaved caspase 3, PI3K, Akt, p-Akt, XIAP, and Survivin are estimated through immunoblotting assay in all three experimental groups.Results:The results showed that all three treated groups, including cisplatin and Ly alone and co-administration of cisplatin+Ly, could reduce the cell vitality of OVCAR3 cancer cells, induced intracellular production of ROS and increased the expression level of activated caspase 3 and Akt protein, whereas down-regulated the phosphorylation of Akt protein. However, the effect of combination therapy was more tangible compared to single therapy and control groups. In contrast, the expression amount of XIAP, Survivin, and PI3K did not show detectable changes in comparison with the control group.Conclusion:The results showed that the AKT inhibition by Ly could sensitize the OVCAR3 cancer cells to the cisplatin and lower the effective dose of cisplatin through hyperactivation of oxidative stress.Key Words: Caspase-3, Cisplatin, Ovarian cancer, PI3K/Akt signaling     

Characterization of 16S rRNA mutations that decrease the fidelity of translation initiation

In bacteria, initiation of translation is kinetically controlled by factors IF1, IF2, and IF3, which work in conjunction with the 30S subunit to ensure accurate selection of the initiator tRNA (fMet-tRNA(fMet)) and the start codon. Here, we show that mutations G1338A and A790G of 16S rRNA decrease initiation fidelity in vivo and do so in distinct ways. Mutation G1338A increases the affinity of tRNA(fMet) for the 30S subunit, suggesting that G1338 normally forms a suboptimal Type II interaction with fMet-tRNA(fMet). By stabilizing fMet-tRNA(fMet) in the preinitiation complex, G1338A may partially compensate for mismatches in the codon-anti-codon helix and thereby increase spurious initiation. Unlike G1338A, A790G decreases the affinity of IF3 for the 30S subunit. This may indirectly stabilize fMet-tRNA(fMet) in the preinitiation complex and/or promote premature docking of the 50S subunit, resulting in increased levels of spurious initiation.     

Enantioselective cyanosilylation of ketones catalyzed by recyclable polymeric and dimeric Mn(III) salen complexes at room temperature

Recyclable polymeric 1 and dimeric 2 chiral Mn(III) salen complexes catalyzed enantioselective cyanosilylation of various ketones in the presence of triphenylphosphine oxide as an additive proceeded smoothly at room temperature, providing excellent yields (up to 98%) and enantiomeric excess (up to 86%) of respective cyanohydrin trimethylsilyl ether. For most of the substrates, the Catalyst 1 showed slightly better reactivity and enantioselecitivity than the Catalyst 2 nevertheless both the catalysts were easily recovered and reused four times with the retention of their efficiency.     

Innate immunity in the human female reproductive tract: antiviral response of uterine epithelial cells to the TLR3 agonist poly(I:C)

The objective of this study was to examine the expression of TLR by human primary uterine epithelial cells (UEC) and to determine whether exposure to the TLR agonist poly(I:C) would induce an antiviral response. The secretion of several cytokines and chemokines was examined as well as the mRNA expression of human beta-defensin-1 and -2 (HBD1 and HBD2), IFN-beta, and the IFN-beta-stimulated genes myxovirus resistance gene 1 and 2',5' oligoadenylate synthetase. The expression of TLR1-9 by UEC was demonstrated by RT-PCR, with only TLR10 not expressed. Stimulation of UEC with the TLR3 agonist poly(I:C) induced the expression of the proinflammatory cytokines TNF-alpha, IL-6, GM-CSF, and G-CSF, as well as the chemokines CXCL8/IL-8, CCL2/MCP-1, and CCL4/MIP-1beta. In addition, poly(I:C) exposure induced the mRNA expression of HBD1 and HBD2 by 6- and 4-fold, respectively. Furthermore, upon exposure to poly(I:C) UEC initiated a potent antiviral response resulting in the induction of IFN-beta mRNA expression 70-fold and myxovirus resistance gene 1 and 2',5' oligoadenylate synthetase mRNA expression (107- and 96-fold), respectively. These results suggest that epithelial cells that line the uterine cavity are sensitive to viral infection and/or exposure to viral dsRNA released from killed epithelial cells. Not only do UEC release proinflammatory cytokines and chemokines that mediate the initiation of an inflammatory response and recruitment of immune cells to the site of infection, but they also express beta-defensins, IFN-beta, and IFN-beta-stimulated genes that can have a direct inhibiting effect on viral replication.