OeFAD8, OeLIP and OeOSM expression and activity in cold-acclimation of Olea europaea,a perennial dicot without winter-dormancy

Planta - Cold-acclimation genes in woody dicots without winter-dormancy, e.g., olive-tree, need investigation. Positive relationships between OeFAD8, OeOSM , and OeLIP19 and olive-tree...     

Molecular basis of ion permeability in a voltage‐gated sodium channel

Voltage‐gated sodium channels are essential for electrical signalling across cell membranes. They exhibit strong selectivities for sodium ions over other cations, enabling the finely tuned cascade of events associated with action potentials. This paper describes the ion permeability characteristics and the crystal structure of a prokaryotic sodium channel, showing for the first time the detailed locations of sodium ions in the selectivity filter of a sodium channel. Electrostatic calculations based on the structure are consistent with the relative cation permeability ratios (Na⁺ ≈ Li⁺ ≫ K⁺, Ca²⁺, Mg²⁺) measured for these channels. In an E178D selectivity filter mutant constructed to have altered ion selectivities, the sodium ion binding site nearest the extracellular side is missing. Unlike potassium ions in potassium channels, the sodium ions in these channels appear to be hydrated and are associated with side chains of the selectivity filter residues, rather than polypeptide backbones.     

Cytotoxicity,apoptosis, DNA damage and methylation in mammary and kidney epithelial cell lines exposed to ochratoxin A

This study aimed to investigate the in vitro damage induced by ochratoxin A (OTA) in BME-UV1 and MDCK epithelial cells. Both cells lines were treated with OTA (0 up to 10 μg/mL), and cell viability (MTT assay), membrane stability (lactate dehydrogenase (LDH) release assay) and apoptotic cell rate (Tunel assay) were investigated. Further, the effect of the incubation with OTA has been evaluated at DNA level by the determination of DNA integrity, by the quantification of DNA adduct formation (8-hydroxy-2′-deoxyguanosine (8-OHdG)) and by the assessment of the global DNA methylation status (5-methyl-cytosine (5-mC)). The obtained results showed that after 24 h of OTA treatment, BME-UV1 cell viability was reduced in a dose-dependent way. OTA significantly (P?<?0.05) increased LDH release in BME-UV1 cells at all concentrations tested. OTA (1.25 μg/mL) induced 35 % LDH release in MDCK cells (P?<?0.05). A significant (P?<?0.05) change in percentages of apoptotic BME-UV1 (10?±?0.86) and MDCK (25?±?0.88) cells was calculated when the cells were co-incubated with OTA. The level of 8-OHdG adduct formation was significantly (P?<?0.05) increased in BME-UV1 cells treated with 1.25 μg/mL of OTA. The results of the present study suggest that a different mechanism of action may occur in these cell lines.

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Pharmacokinetic stability of macrocyclic peptide triazole HIV‐1 inactivators alone and in liposomes

Previously, we reported the discovery of macrocyclic peptide triazoles (cPTs) that bind to HIV‐1 Env gp120, inhibit virus cell infection with nanomolar potencies, and cause irreversible virion inactivation. Given the appealing virus‐killing activity of cPTs and resistance to protease cleavage observed in vitro, we here investigated in vivo pharmacokinetics of the cPT AAR029b. AAR029b was investigated both alone and encapsulated in a PEGylated liposome formulation that was designed to slowly release inhibitor. Pharmacokinetic analysis in rats showed that the half‐life of FITC‐AAR029b was substantial both alone and liposome‐encapsulated, 2.92 and 8.87 hours, respectively. Importantly, liposome‐encapsulated FITC‐AAR029b exhibited a 15‐fold reduced clearance rate from serum compared with the free FITC‐cPT. This work thus demonstrated both the in vivo stability of cPT alone and the extent of pharmacokinetic enhancement via liposome encapsulation. The results obtained open the way to further develop cPTs as long‐acting HIV‐1 inactivators against HIV‐1 infection.     

Precise Gene Editing Preserves Hematopoietic Stem Cell Function following Transient p53-Mediated DNA Damage Response

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The cytokine, granulocyte-macrophage colony-stimulating factor (GM-CSF), can deliver Bcl-XL as an extracellular fusion protein to protect cells from apoptosis and retain differentiation induction

Bcl-XL, a member of the Bcl-2 protein family, is able to suppress cell death induced by diverse stimuli in many cell types, including hematopoietic cells. Human granulocyte-macrophage colony-stimulating factor (GM-CSF) is a cytokine that promotes the proliferation and maturation of neutrophils, eosinophils, and macrophages from bone marrow progenitors. We fused GM-CSF to Bcl-XL and examined the capacity of this chimera to bind human cells through the GM-CSF receptor and prevent apoptosis. We found that the chimeric protein increased the proliferation of human monocytes in culture from 24 h until at least 72 h. In the presence of different apoptotic agents, GM-CSF-Bcl-XL protected cells from induced cell death and promoted proliferation, whereas GM-CSF alone was completely inhibited. In the presence of cytarabine, GM-CSF-Bcl-XL was able also to promote the differentiation of the CD34+ myeloid precursor whereas Lfn-Bcl-XL, lacking the GM-CSF domain-stimulated cell proliferation and not differentiation. We conclude that recombinant GM-CSF-Bcl-XL binds the GM-CSF receptor on human monocyte/macrophage cells and bone marrow progenitors inducing differentiation and allowing Bcl-XL entry into cells where it blocks cell death and allows amplified cell proliferation. This fully human fusion protein has potential to prevent monocytopenia and represents a new strategy for engineering anti-apoptotic therapeutics.     

Xeno-cannibalism: a survival "escamotage"

Several lines of evidence have demonstrated that self-cannibalism (macroautophagy) is a well regulated process of cell repair as well as of molecule and organelle recycling that allows the cells to survive. However, autophagic activity also represents a cell death pathway characterized by specific features that differentiate autophagy from other cell death processes. We found that cells that are able to exert intense autophagic activity were also able to engulf and digest entire cell siblings. This phenomenon represents a sort of xeno-cannibalism. We wonder whether these two phenomena, self and xeno-cannibalism, could be related the latter being an exacerbation of the first and providing a further survival option to the cells.