Role of programmed cell death in patterning the Drosophila antennal arista

Programmed cell death is a critical process for the patterning and sculpting of organs during development. The Drosophila arista, a feather-like structure at the tip of the antenna, is composed of a central core and several lateral branches. A homozygous viable mutation in the thread gene, which encodes an inhibitor of apoptosis protein, produces a branchless arista. We have found that mutations in the proapoptotic gene hid lead to numerous extra branches, suggesting that the level of cell death determines the number of branches in the arista. Consistent with this idea, we have found that thread mutants show excessive cell death restricted to the antennal imaginal disc during the middle third instar larval stage. These findings point to a narrow window of development in which regulation of programmed cell death is essential to the proper formation of the arista.     

Apolipoprotein E isoforms and apolipoprotein AI protect from amyloid precursor protein carboxy terminal fragment-associated cytotoxicity

Inheritance of the apolipoprotein (APO) E gene epsilon4 or epsilon2 allele alters the risk of developing Alzheimer disease (AD), while increased alpha-tocopherol (AT) intake appears to lower the risk of AD. As APOE is a major apolipoprotein in the CNS and AT in vivo is transported in lipoproteins, we tested the hypothesis that CNS lipoproteins, as modeled by relevant concentrations of high density lipoprotein (HDL), and AT would interact to suppress neurotoxicity in a cell culture model of amyloid beta (Abeta)- related toxicity. These cells conditionally express C99-derived peptides, proposed to be a key step in AD pathogenesis; this expression is closely associated with subsequent cell death. We found that physiologic concentrations of lipoproteins present in the CNS protected from C99-associated toxicity and provided evidence for two mechanisms of protection. The first was AT-independent, APOE isoform-dependent, and most potent for the APOE2 isoform. The second was a synergistic protection afforded by a combination of APOAI, or less so APOE, and AT. These data provide a novel explanation for the apparent AD-protective effect of inheriting an epsilon2 APOE allele, and suggest that optimizing AT enrichment of CNS lipoproteins or devising APOAI mimetics may augment AT efficacy in treating AD.     

Synthesis, characterization and X-ray crystal structure of [Re(L4)(CO)3]Br · 2CH3OH (L4 = N,N-bis[(2-diphenylphosphino)ethyl]methoxyethylamine): A model compound for novel cationic Tc(I)-tricarbonyl radiotracers useful for heart imaging

This report describes synthesis and evaluation of cationic complexes, [^99mTc(CO)₃(L)]⁺ (L = N-methoxyethyl-N,N-bis[2-(bis(3-ethoxypropyl)phosphino)ethyl]amine (L1), N-[(15-crown-5)-2-yl]-N,N-bis[2-(bis(3-ethoxypropyl)phosphino)ethyl]amine (L2) and N-[(18-crown-6)-2-yl]-N,N-bis[2-(bis(3-ethoxypropyl)phosphino)ethyl]amine (L3)) as potential radiotracers for heart imaging. Preliminary results from biodistribution studies in female adult BALB-c mice indicated that the cationic ^99mTc(I)-tricarbonyl complex, [^99mTc(CO)₃(L2)]⁺, has a significant localization in the heart at 60 min post-injection. To understand the coordination chemistry of these bisphosphine ligands with the ^99mTc(I)-tricarbonyl core, we prepared [Re(CO)₃(L4)]Br (L4: N,N-bis[(2-diphenylphosphino)ethyl]methoxyethylamine) as a model compound. [Re(CO)₃(L4)]Br has been characterized by elemental analysis, IR, ESI-MS, NMR (¹H, ¹³C, ¹H-¹H COSY, and ¹H-¹³C HMQC) methods, and X-ray crystallography. In solid state, [Re(CO)₃(L4)]⁺ has a distorted octahedron coordination geometry with PNP occupying one facial plane. The chelator backbone adopts a “chair” conformation with phosphine-P atoms at equatorial positions and the amine-N at the apical site. In solution, [Re(CO)₃(L4)]⁺ is able to maintain its cationic nature with no dissociation of carbonyl ligands or any of the three PNP donors.     

Renoprotective effect of Erdosteine in rats against gentamicin nephrotoxicity: a comparison of 99mTc-DMSA uptake with biochemical studies

Erdosteine is a mucolytic agent having antioxidant properties through its active metabolites in acute injuries induced by pharmacological drugs. This study was designed to investigate the renoprotective potential of Erdosteine against gentamicin (GM)-induced renal dysfunction by using Technetium-99 m dimercaptosuccinic acid (Tc-99 m DMSA) uptake and scintigraphy in rats. For this purpose, male Wistar rats were randomly allotted into one of the four experimental groups: Control, Erdosteine, GM, and GM + Erdosteine groups. GM and GM + Erdosteine groups received 100 mg/kg GM intramuscularly for 6 days. In addition, Erdosteine and GM + Erdosteine groups received 50 mg/kg Erdosteine orally for 6 days. Renal function tests were assessed by serum blood urea nitrogen (BUN), creatinine levels, as well as scintigraphic and tissue radioactivity measurements with Tc-99 m DMSA. Renal oxidative damage was determined by renal malondialdehyde (MDA) levels, by antioxidant enzyme activities; superoxide dismutase (SOD) and catalase (CAT) and activities of oxidant enzymes; xanthine oxidase (XO) and myeloperoxidase (MPO). GM administration resulted in marked renal lipid peroxidation, increased XO and MPO activities and decreased antioxidant enzyme activities. GM + Erdosteine group significantly had lower MDA levels, higher SOD and CAT activities and lower XO and MPO activities, when compared to GM. Also GM + Erdosteine had lower levels of serum BUN, creatinine and higher renal tissue Tc-99 m DMSA uptake and radioactivity with respect to GM. In conclusion, our results supported a protective role of Erdosteine in nephrotoxicity associated with GM treatment.     

Enzymatic synthesis of 2-ethylhexyl esters of fatty acids by immobilized lipase from Candida sp. 99–125

The 2-ethylhexyl esters of fatty acids were synthesized by immobilized lipase from Candida sp. 99–125. The reuse stability of immobilized lipase was at least four batches. The conditions of enzymatic synthesis of 2-ethylhexyl palmitate were optimized. In the system of petroleum ether, 10% (w/w) immobilized lipase was used in the esterfication of 2-ethyl hexanol (7.8 mmol) and palmitic acid (7.8 mmol) at 40 °C with silica gel as the water absorbent. The esterification degree was 91% under these conditions. The purity of 2-ethylhexyl palmitate was 98% after purification consisting washing by water and evaporation to remove the organic solvent.     

Sampling Blood from the Lateral Tail Vein of the Rat

Blood samples are commonly obtained in many experimental contexts to measure targets of interest, including hormones, immune factors, growth factors, proteins, and glucose, yet the composition of the blood is dynamically regulated and easily perturbed. One factor that can change the blood composition is the stress response triggered by the sampling procedure, which can contribute to variability in the measures of interest. Here we describe a procedure for blood sampling from the lateral tail vein in the rat. This procedure offers significant advantages over other more commonly used techniques. It permits rapid sampling with minimal pain or invasiveness, without anesthesia or analgesia. Additionally, it can be used to obtain large volume samples (upwards of 1 ml in some rats), and it may be used repeatedly across experimental days. By minimizing the stress response and pain resulting from blood sampling, measures can more accurately reflect the true basal state of the animal, with minimal influence from the sampling procedure itself.     

Targeting of EIF4EBP1 by miR-99a-3p affects the functions of B lymphocytes via autophagy and aggravates SLE disease progression

Excessive activation of immune cells plays a key role in the pathogenesis of systemic lupus erythematosus (SLE). The regulation of immune cells by miRNAs is a research hotspot. In this study, second-generation high-throughput sequencing revealed a reduction in miR-99a-3p expression in patients with SLE; however, the specific mechanism underlying this phenomenon remains unclear. After transfection with an miR-99a-3p agomir, the proliferation of Ball-1 cells decreased and the levels of their apoptosis increased. The opposite effects were observed in cells transfected with the miR-99a-3p antagomir. Luciferase reporter assay indicated that miR-99a-3p directly targeted EIF4EBP1. Rescue experiments confirmed the proposed interaction between miR-99a-3p and EIF4EBP1. In vitro, in vivo and clinical investigations further confirmed that the miR-99a-3p agomir reduced the expression of EIF4EBP1, LC3B and LAMP-2A. In the in vivo experiments, serum levels of anti-nuclear antibodies, double-stranded DNA, IgE, IgM, IL-6, IL-10 and B lymphocyte stimulator were higher in mice from the antagomir group than those in mice from the MRL/lpr group. Furthermore, the protein and mRNA levels of EIF4EBP1, LC3B and LAMP-2A, the intensity of immunohistochemical staining of EIF4EBP1, LC3B and LAMP-2A, the urinary protein levels, and the C3 immunofluorescence deposition increased in mice from the antagomir group. The upregulation of miR-99a-3p expression protected B cells from EIF4EBP1-mediated autophagy, whilst the downregulation of miR-99a-3p expression induced autophagy via the EIF4EBP1-mediated regulation of the autophagy signalling pathway in B cells isolated from individuals with SLE. Based on these results, miR-99a-3p and EIF4EBP1 may be considered potential targets for SLE treatment.     

Discovery of heterocyclic replacements for the coumarin core of anti-tubercular FadD32 inhibitors

Previous work established a coumarin scaffold as a starting point for inhibition of Mycobacterium tuberculosis (Mtb) FadD32 enzymatic activity. After further profiling of the coumarin inhibitor 4 revealed chemical instability, we discovered that a quinoline ring circumvented this instability and had the advantage of offering additional substitution vectors to further optimize. Ensuing SAR studies gave rise to quinoline-2-carboxamides with potent anti-tubercular activity. Further optimization of ADME/PK properties culminated in 21b that exhibited compelling in vivo efficacy in a mouse model of Mtb infection.