Inhibition of x‐box binding protein 1 reduces tunicamycin‐induced apoptosis in aged murine macrophages

Endoplasmic reticulum (ER) stress is induced by the accumulation of unfolded and misfolded proteins in the ER. Although apoptosis induced by ER stress has been implicated in several aging‐associated diseases, such as atherosclerosis, it is unclear how aging modifies ER stress response in macrophages. To decipher this relationship, we assessed apoptosis in macrophages isolated from young (1.5–2 months) and aged (16–18 months) mice and exposed the cells to the ER stress inducer tunicamycin. We found that aged macrophages exhibited more apoptosis than young macrophages, which was accompanied by reduced activation of phosphorylated inositol‐requiring enzyme‐1 (p‐IRE1α), one of the three key ER stress signal transducers. Reduced gene expression of x‐box binding protein 1 (XBP1), a downstream effector of IRE1α, enhanced p‐IRE1α levels and reduced apoptosis in aged, but not young macrophages treated with tunicamycin. These findings delineate a novel, age‐dependent interaction by which macrophages undergo apoptosis upon ER stress, and suggest an important protective role of IRE1α in aging‐associated ER stress‐induced apoptosis. This novel pathway may not only be important in our understanding of longevity, but may also have important implications for pathogenesis and potential treatment of aging‐associated diseases in general.     

The gastrointestinal manifestations of telomere‐mediated disease

Defects in telomere maintenance genes cause pathological telomere shortening, and manifest in syndromes which have prominent phenotypes in tissues of high turnover: the skin and bone marrow. Because the gastrointestinal (GI) epithelium is highly proliferative, we sought to determine whether telomere syndromes cause GI disease, and to define its prevalence, spectrum, and natural history. We queried subjects in the Johns Hopkins Telomere Syndrome Registry for evidence of luminal GI disease. In sixteen percent of Registry subjects (6 of 38), there was a history of significant GI pathology, and 43 additional cases were identified in the literature. Esophageal stenosis, enteropathy, and enterocolitis were the recurrent findings. In the intestinal mucosa, there was striking villous atrophy, extensive apoptosis, and anaphase bridging pointing to regenerative defects in the epithelial compartment. GI disease was often the first and most severe manifestation of telomere disease in young children. These findings indicate that telomere dysfunction disrupts the epithelial integrity in the human GI tract manifesting in recognizable disease processes. A high index of suspicion should facilitate diagnosis and management.     

CARAGANA FABR. PROMOTES REVEGETATION AND SOIL REHABILITATION IN SALINE-ALKALI WASTELAND

To determine how plantations of Caragana microphylla shrubs affect saline-alkali soil amelioration and revegetation, we investigated the vegetation and sampled soils from saline-alkali wasteland (SAW), perennial Caragana forestland (PCF), Caragana forest after fire disturbance (CFF). Results showed that with the development of Caragana Fabr., highly dominant species of Poaceae family, including Elymus dahuricus, Thermopsis lanceolata, Stipa tianschanica, died out in PCF. Moreover, Papilionaceae family, including Lespedeza indica, Oxytropis psammocharis, and Astragalus scaberrimus, was established both in PCF and CFF. Phytoremediation of saline-alkali wasteland (SAW) was achieved by plantation, resulting in the reduced soil pH, sodium adsorption ratio, exchangeable sodium percentage, salinity, and Na⁺ concentration around Caragana shrubs. Greater amounts of soil organic, total nitrogen, ammonium nitrogen, available phosphorus, and available potassium were observed in PCF topsoil than in SAW topsoil. The concentration of mineralized N in PCF soil was significantly lower than that in SAW soil at all sampled depths, indicating that Caragana shrubs were just using N and therefore less measured in soils. Fire disturbance resulted in decreased soil pH and salinity, but increased organic content, total nitrogen, and ammonium nitrogen. The improved soil parameters and self-recovery of shrubs indicated that Caragana shrubs were well established after burning event.     

Flow‐injection chemiluminescence determination of diazepam by oxidation with N‐bromosuccinimide

A rapid and sensitive flow‐injection chemiluminescence (FI–CL) method is described for the determination of diazepam based on its reaction with N‐bromosuccinimide (NBS) in alkaline medium in the presence of dichlorofluorescein (DCF) as an effective energy‐transfer agent. Under optimum conditions, the proposed method allowed the measurement of diazepam over the range of 2.0 × 10^?6 to 2.0 × 10^?4 mol/L with a detection limit of 5.0 × 10^?7 mol/L. The relative standard deviation for 11 parallel measurements of 2.0 × 10^?5 mol/L diazepam was 2.1%. The method was applied satisfactorily for the determination of diazepam in pharmaceutical preparations, and the results agree well with those obtained by spectrophotometry. The use of the proposed system for the determination of diazepam in urine and plasma samples was also tested. The possible mechanism of the chemiluminescence reaction is discussed briefly. Copyright © 2012 John Wiley & Sons, Ltd.     

Rapid methods of detecting the target molecule in immunohistology using a bioluminescence probe

We demonstrate a novel rapid direct detection method for immunohistochemistry, using a bioluminescent probe. An anti‐CEA antibody‐fused far‐red bioluminescent protein can monitor the accumulation of this type of probe in tumour tissues. The bimodal spectrum (λ_max = 460 and 675 nm) of this bioluminescent probe is extremely stable under different conditions of pH and ion concentration. The sensitivity of our bioluminescent labelling was at the same level of enzymatic labelling, e.g. peroxidase, as an indirect system. Our novel technique is simple and can shorten the pretreatment time of paraffin sections to around 30 min. The utility of our bioluminescent labelling covers all imaging in vitro, in vivo and ex vivo, suggesting that our antibody‐fused bioluminescent probe has the potential to detect tumour antigens with a high sensitivity in routine immune histological examinations. Copyright © 2012 John Wiley & Sons, Ltd.     

AN IMPROVED SYNTHESIS OF 9-[2-(DIETHOXYPHOSPHONOMETHOXY)ETHYL]ADENINE AND ITS ANALOGUES WITH OTHER PURINE BASES UTILIZING THE MITSUNOBU REACTION

Abstract

Unprotected adenine, 6-chloropurine, 2.6-diaminopurine. and 2-amino-6-chluropurine have been directly coupled with 2-(diethoxyphosphonomethoxy)ethanol under Mitsunobu reaction conditions to provide acyclic phosphonate nucleotide analogues which are intermediates for antiviral agents such as PMEA.     

Studies of the Pharmacokinetics and Toxicology of 2′,3′-Dideoxy-β-L-5-fluorocytidine (β-L-FddC) and 2′,3′-Dideoxy-β-L-cytidine (β-L-ddC) In Vivo; and Synthesis and Antiviral Evaluations of 2′,3′-Dideoxy-β-L-5-azacytidine

Abstract

The pharmacokinetics and toxicology of 2′,3′-dideoxy-β-L-5-fluorocytidine (β-L-FddC) and 2′,3′-dideoxy-β-L-cytidine (β-L-ddC) in mice was investigated. In addition, 2′,3′-dideoxy-β-L-5-azacytidine (β-L-5-aza-ddC) and its α-L-anomer (α-L-5-aza-ddC) were synthesized by coupling the silylated 5-azacytosine derivative with 1-O-acetyl-5-O-(tert-butyldimethylsilyl)-2,3-dideoxy-L-ribofuranose, followed by separation of the α-and β-anomers and were evaluated in vitro against HBV and HIV. β-L-5-aza-ddC was found to show significant anti-HBV activity at approximately the same level as 2′,3′-dideoxy-β-D-cytidine (ddC), which is a known anti-HBV agent. β-L-5-aza-ddC was not cytotoxic to L1210, P388, S-180, and CCRF-CEM cells up to a concentration of 100 μ. Conversely, the α-L-anomer was not active against HBV at the same concentration.     

Parallel-Stranded DNA Formed by New Base Pairs Related to the Isoguanine-Cytosine or Isocytosine-Guanine Motifs

Abstract

Parallel-stranded (ps) oligonucleotide duplexes containing several new base pairs formed between 7-deazaisoguanine and cytosine, 8-aza-7-deaza-isoguanine and cytosine, and 5-aza-7-deaza guanine and guanine are described. The stability of the pshybrids increased if the duplex contains 8-aza-7-deazaisoguanine instead of isoguanine and is decreased by 7-deazaisoguanine incorporation. The purine-purine base pair between 5-aza-7-deazaguanine and guanine was found to be more stable than that of 5-methylisocytosine with guanine.     

Structure-Activity Relationships Among a New Class of Antiviral Heterosubstituted 2′,3′-Dideoxynucleoside Analogues

Abstract

3′-Oxa-4′-thiocytidine nucleoside analogues 14–17 were prepared from oxathiolanes 10 and 11, and evaluated for activity against HIV-1 and HBV in vitro. The nucleoside analogues were found to possess potent activities against HIV-1 in a panel of cell lines. Compound 16 is moderately active against HBV in 2.2.15 cells.     

Parallel-Stranded Duplex DNA and Self-Assembled Quartet Structures Formed by Isoguanine and Related Bases

Abstract

Parallel-stranded (ps) oligonucleotide duplexes are described containing isoguanine-cytosine and/or 5-methylisocytosine-guanine base pairs. A parallel hybrid is also formed when 5-aza-7-deazaguanine base pairs with guanine while the base pair with isoguanine results in an antiparallel duplex. Oligomers such as d(T₄isoG₄T₄) form selfassembled tetraplexes which show a cation selectivity different from that of the G-quartet.